Merge "defconfig: Add changes to build cfg80211 as module" into msm-3.0
diff --git a/Documentation/devicetree/bindings/arm/msm/rpm-smd.txt b/Documentation/devicetree/bindings/arm/msm/rpm-smd.txt
new file mode 100644
index 0000000..8ebd3ba
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/rpm-smd.txt
@@ -0,0 +1,30 @@
+Resource Power Manager(RPM)
+
+RPM is a dedicated hardware engine for managing shared SoC resources,
+which includes buses, clocks, power rails, etc.  The goal of RPM is
+to achieve the maximum power savings while satisfying the SoC's
+operational and performance requirements.  RPM accepts resource
+requests from multiple RPM masters.  It arbitrates and aggregates the
+requests, and configures the shared resources.  The RPM masters are
+the application processor, the modem processor, as well as hardware
+accelerators. The RPM driver communicates with the hardware engine using
+SMD.
+
+The devicetree representation of the SPM block should be:
+
+Required properties
+
+- compatible: "qcom,rpm-smd"
+- rpm-channel-name: The string corresponding to the channel name of the
+			peripheral subsystem
+- rpm-channel-type: The interal SMD edge for this subsystem found in
+			<mach/msm_smd.h>
+
+Example:
+
+	qcom,rpm-smd {
+		compatible = "qcom,rpm-smd"
+		qcom,rpm-channel-name = "rpm_requests";
+		qcom,rpm-channel-type = 15; /* SMD_APPS_RPM */
+	}
+}
diff --git a/arch/arm/boot/dts/msmcopper.dtsi b/arch/arm/boot/dts/msmcopper.dtsi
index aa7adc5..2230e0e 100644
--- a/arch/arm/boot/dts/msmcopper.dtsi
+++ b/arch/arm/boot/dts/msmcopper.dtsi
@@ -278,7 +278,7 @@
 		reg = <0xfe200000 0x00100>,
 		      <0xfd485100 0x00010>;
 
-		qcom,firmware-name = "lpass";
+		qcom,firmware-name = "adsp";
 	};
 
 	qcom,pronto@fb21b000 {
@@ -294,4 +294,10 @@
 	qcom,ocmem@fdd00000 {
 		compatible = "qcom,msm_ocmem";
 	};
+
+	qcom,rpm-smd {
+		compatible = "qcom,rpm-smd";
+		rpm-channel-name = "rpm_requests";
+		rpm-channel-type = <15>; /* SMD_APPS_RPM */
+	};
 };
diff --git a/arch/arm/mach-msm/Kconfig b/arch/arm/mach-msm/Kconfig
index c9d0000..423e71e 100644
--- a/arch/arm/mach-msm/Kconfig
+++ b/arch/arm/mach-msm/Kconfig
@@ -257,8 +257,8 @@
 	select MSM_PIL
 	select MSM_SPM_V2
 	select MSM_L2_SPM
-	select MSM_RPM
 	select MSM_PM8X60 if PM
+	select MSM_RPM_SMD
 
 config ARCH_FSM9XXX
 	bool "FSM9XXX"
@@ -387,6 +387,10 @@
 	bool "Resource Power Manager"
 	select MSM_MPM
 
+config MSM_RPM_SMD
+	depends on MSM_SMD
+	bool "Support for using SMD as the transport layer for communicatons with RPM"
+
 config MSM_MPM
 	bool "Modem Power Manager"
 
diff --git a/arch/arm/mach-msm/Makefile b/arch/arm/mach-msm/Makefile
index 2295679..6a90d6d 100644
--- a/arch/arm/mach-msm/Makefile
+++ b/arch/arm/mach-msm/Makefile
@@ -364,3 +364,5 @@
 
 obj-$(CONFIG_MSM_HSIC_SYSMON) += hsic_sysmon.o
 obj-$(CONFIG_MSM_HSIC_SYSMON_TEST) += hsic_sysmon_test.o
+
+obj-$(CONFIG_MSM_RPM_SMD) += rpm-smd.o
diff --git a/arch/arm/mach-msm/board-8064.c b/arch/arm/mach-msm/board-8064.c
index d04e5e4..7ab3894 100644
--- a/arch/arm/mach-msm/board-8064.c
+++ b/arch/arm/mach-msm/board-8064.c
@@ -865,9 +865,11 @@
 
 static void __init apq8064_ehci_host_init(void)
 {
-	if (machine_is_apq8064_liquid()) {
-		msm_ehci_host_pdata3.dock_connect_irq =
-				PM8921_MPP_IRQ(PM8921_IRQ_BASE, 9);
+	if (machine_is_apq8064_liquid() || machine_is_mpq8064_cdp() ||
+		machine_is_mpq8064_hrd() || machine_is_mpq8064_dtv()) {
+		if (machine_is_apq8064_liquid())
+			msm_ehci_host_pdata3.dock_connect_irq =
+					PM8921_MPP_IRQ(PM8921_IRQ_BASE, 9);
 
 		apq8064_device_ehci_host3.dev.platform_data =
 				&msm_ehci_host_pdata3;
diff --git a/arch/arm/mach-msm/board-copper.c b/arch/arm/mach-msm/board-copper.c
index c28d172..f5fe3d1 100644
--- a/arch/arm/mach-msm/board-copper.c
+++ b/arch/arm/mach-msm/board-copper.c
@@ -39,6 +39,7 @@
 #endif
 #include <mach/msm_memtypes.h>
 #include <mach/msm_smd.h>
+#include <mach/rpm-smd.h>
 #include <mach/qpnp-int.h>
 #include <mach/socinfo.h>
 #include "clock.h"
@@ -448,6 +449,7 @@
 void __init msm_copper_add_drivers(void)
 {
 	msm_smd_init();
+	msm_rpm_driver_init();
 	msm_spm_device_init();
 	regulator_stub_init();
 }
diff --git a/arch/arm/mach-msm/clock-8960.c b/arch/arm/mach-msm/clock-8960.c
index 93251a4..3ee59b1 100644
--- a/arch/arm/mach-msm/clock-8960.c
+++ b/arch/arm/mach-msm/clock-8960.c
@@ -42,6 +42,7 @@
 
 /* Peripheral clock registers. */
 #define ADM0_PBUS_CLK_CTL_REG			REG(0x2208)
+#define SFAB_SATA_S_HCLK_CTL_REG		REG(0x2480)
 #define CE1_HCLK_CTL_REG			REG(0x2720)
 #define CE1_CORE_CLK_CTL_REG			REG(0x2724)
 #define PRNG_CLK_NS_REG				REG(0x2E80)
@@ -108,10 +109,12 @@
 #define TSIF_REF_CLK_MD_REG			REG(0x270C)
 #define TSIF_REF_CLK_NS_REG			REG(0x2710)
 #define TSSC_CLK_CTL_REG			REG(0x2CA0)
+#define SATA_HCLK_CTL_REG			REG(0x2C00)
 #define SATA_CLK_SRC_NS_REG			REG(0x2C08)
 #define SATA_RXOOB_CLK_CTL_REG			REG(0x2C0C)
 #define SATA_PMALIVE_CLK_CTL_REG		REG(0x2C10)
 #define SATA_PHY_REF_CLK_CTL_REG		REG(0x2C14)
+#define SATA_ACLK_CTL_REG			REG(0x2C20)
 #define SATA_PHY_CFG_CLK_CTL_REG		REG(0x2C40)
 #define USB_FSn_HCLK_CTL_REG(n)			REG(0x2960+(0x20*((n)-1)))
 #define USB_FSn_RESET_REG(n)			REG(0x2974+(0x20*((n)-1)))
@@ -1926,6 +1929,69 @@
 	}
 };
 
+#define F_SATA(f, s, d) \
+	{ \
+		.freq_hz = f, \
+		.src_clk = &s##_clk.c, \
+		.ns_val = NS_DIVSRC(6, 3, d, 2, 0, s##_to_bb_mux), \
+	}
+
+static struct clk_freq_tbl clk_tbl_sata[] = {
+	F_SATA(        0,  gnd, 1),
+	F_SATA( 48000000, pll8, 8),
+	F_SATA(100000000, pll3, 12),
+	F_END
+};
+
+static struct rcg_clk sata_src_clk = {
+	.b = {
+		.ctl_reg = SATA_CLK_SRC_NS_REG,
+		.halt_check = NOCHECK,
+	},
+	.ns_reg = SATA_CLK_SRC_NS_REG,
+	.root_en_mask = BIT(7),
+	.ns_mask = BM(6, 0),
+	.set_rate = set_rate_nop,
+	.freq_tbl = clk_tbl_sata,
+	.current_freq = &rcg_dummy_freq,
+	.c = {
+		.dbg_name = "sata_src_clk",
+		.ops = &clk_ops_rcg,
+		VDD_DIG_FMAX_MAP2(LOW, 50000000, NOMINAL, 100000000),
+		CLK_INIT(sata_src_clk.c),
+	},
+};
+
+static struct branch_clk sata_rxoob_clk = {
+	.b = {
+		.ctl_reg = SATA_RXOOB_CLK_CTL_REG,
+		.en_mask = BIT(4),
+		.halt_reg = CLK_HALT_MSS_SMPSS_MISC_STATE_REG,
+		.halt_bit = 26,
+	},
+	.parent = &sata_src_clk.c,
+	.c = {
+		.dbg_name = "sata_rxoob_clk",
+		.ops = &clk_ops_branch,
+		CLK_INIT(sata_rxoob_clk.c),
+	},
+};
+
+static struct branch_clk sata_pmalive_clk = {
+	.b = {
+		.ctl_reg = SATA_PMALIVE_CLK_CTL_REG,
+		.en_mask = BIT(4),
+		.halt_reg = CLK_HALT_MSS_SMPSS_MISC_STATE_REG,
+		.halt_bit = 25,
+	},
+	.parent = &sata_src_clk.c,
+	.c = {
+		.dbg_name = "sata_pmalive_clk",
+		.ops = &clk_ops_branch,
+		CLK_INIT(sata_pmalive_clk.c),
+	},
+};
+
 static struct branch_clk sata_phy_ref_clk = {
 	.b = {
 		.ctl_reg = SATA_PHY_REF_CLK_CTL_REG,
@@ -1941,6 +2007,47 @@
 	},
 };
 
+static struct branch_clk sata_a_clk = {
+	.b = {
+		.ctl_reg = SATA_ACLK_CTL_REG,
+		.en_mask = BIT(4),
+		.halt_reg = CLK_HALT_AFAB_SFAB_STATEA_REG,
+		.halt_bit = 12,
+	},
+	.c = {
+		.dbg_name = "sata_a_clk",
+		.ops = &clk_ops_branch,
+		CLK_INIT(sata_a_clk.c),
+	},
+};
+
+static struct branch_clk sata_p_clk = {
+	.b = {
+		.ctl_reg = SATA_HCLK_CTL_REG,
+		.en_mask = BIT(4),
+		.halt_reg = CLK_HALT_MSS_SMPSS_MISC_STATE_REG,
+		.halt_bit = 27,
+	},
+	.c = {
+		.dbg_name = "sata_p_clk",
+		.ops = &clk_ops_branch,
+		CLK_INIT(sata_p_clk.c),
+	},
+};
+
+static struct branch_clk sfab_sata_s_p_clk = {
+	.b = {
+		.ctl_reg = SFAB_SATA_S_HCLK_CTL_REG,
+		.en_mask = BIT(4),
+		.halt_reg = CLK_HALT_AFAB_SFAB_STATEB_REG,
+		.halt_bit = 14,
+	},
+	.c = {
+		.dbg_name = "sfab_sata_s_p_clk",
+		.ops = &clk_ops_branch,
+		CLK_INIT(sfab_sata_s_p_clk.c),
+	},
+};
 static struct branch_clk pcie_p_clk = {
 	.b = {
 		.ctl_reg = PCIE_HCLK_CTL_REG,
@@ -4550,7 +4657,11 @@
 	{ TEST_PER_LS(0x56), &gsbi7_uart_clk.c },
 	{ TEST_PER_LS(0x58), &gsbi7_qup_clk.c },
 	{ TEST_PER_LS(0x59), &gsbi8_p_clk.c },
+	{ TEST_PER_LS(0x59), &sfab_sata_s_p_clk.c },
 	{ TEST_PER_LS(0x5A), &gsbi8_uart_clk.c },
+	{ TEST_PER_LS(0x5A), &sata_p_clk.c },
+	{ TEST_PER_LS(0x5B), &sata_rxoob_clk.c },
+	{ TEST_PER_LS(0x5C), &sata_pmalive_clk.c },
 	{ TEST_PER_LS(0x5C), &gsbi8_qup_clk.c },
 	{ TEST_PER_LS(0x5D), &gsbi9_p_clk.c },
 	{ TEST_PER_LS(0x5E), &gsbi9_uart_clk.c },
@@ -4606,6 +4717,7 @@
 	{ TEST_PER_HS(0x26), &q6sw_clk },
 	{ TEST_PER_HS(0x27), &q6fw_clk },
 	{ TEST_PER_HS(0x2A), &adm0_clk.c },
+	{ TEST_PER_HS(0x31), &sata_a_clk.c },
 	{ TEST_PER_HS(0x2D), &pcie_phy_ref_clk.c },
 	{ TEST_PER_HS(0x32), &pcie_a_clk.c },
 	{ TEST_PER_HS(0x34), &ebi1_clk.c },
@@ -4967,6 +5079,12 @@
 	CLK_LOOKUP("sys_clk",		usb_fs1_sys_clk.c,	""),
 	CLK_LOOKUP("ref_clk",		sata_phy_ref_clk.c,	""),
 	CLK_LOOKUP("cfg_clk",		sata_phy_cfg_clk.c,	""),
+	CLK_LOOKUP("src_clk",		sata_src_clk.c,		""),
+	CLK_LOOKUP("core_rxoob_clk",	sata_rxoob_clk.c,	""),
+	CLK_LOOKUP("core_pmalive_clk",	sata_pmalive_clk.c,	""),
+	CLK_LOOKUP("bus_clk",		sata_a_clk.c,		""),
+	CLK_LOOKUP("iface_clk",		sata_p_clk.c,		""),
+	CLK_LOOKUP("slave_iface_clk",	sfab_sata_s_p_clk.c,	""),
 	CLK_LOOKUP("iface_clk",		ce3_p_clk.c,		"qce.0"),
 	CLK_LOOKUP("iface_clk",		ce3_p_clk.c,		"qcrypto.0"),
 	CLK_LOOKUP("core_clk",		ce3_core_clk.c,		"qce.0"),
@@ -5982,9 +6100,14 @@
 	if (cpu_is_msm8960() || cpu_is_apq8064())
 		rmwreg(0x2, DSI2_BYTE_NS_REG, 0x7);
 
-	/* Source the sata_phy_ref_clk from PXO */
-	if (cpu_is_apq8064())
+	/*
+	 * Source the sata_phy_ref_clk from PXO and set predivider of
+	 * sata_pmalive_clk to 1.
+	 */
+	if (cpu_is_apq8064()) {
 		rmwreg(0, SATA_PHY_REF_CLK_CTL_REG, 0x1);
+		rmwreg(0, SATA_PMALIVE_CLK_CTL_REG, 0x3);
+	}
 
 	/*
 	 * TODO: Programming below PLLs and prng_clk is temporary and
diff --git a/arch/arm/mach-msm/include/mach/rpm-smd.h b/arch/arm/mach-msm/include/mach/rpm-smd.h
new file mode 100644
index 0000000..ff58fed
--- /dev/null
+++ b/arch/arm/mach-msm/include/mach/rpm-smd.h
@@ -0,0 +1,254 @@
+/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef __ARCH_ARM_MACH_MSM_RPM_SMD_H
+#define __ARCH_ARM_MACH_MSM_RPM_SMD_H
+
+/**
+ * enum msm_rpm_set - RPM enumerations for sleep/active set
+ * %MSM_RPM_CTX_SET_0: Set resource parameters for active mode.
+ * %MSM_RPM_CTX_SET_SLEEP: Set resource parameters for sleep.
+ */
+enum msm_rpm_set {
+	MSM_RPM_CTX_ACTIVE_SET,
+	MSM_RPM_CTX_SLEEP_SET,
+};
+
+struct msm_rpm_request;
+
+struct msm_rpm_kvp {
+	uint32_t key;
+	uint32_t length;
+	uint8_t *data;
+};
+#ifdef CONFIG_MSM_RPM_SMD
+/**
+ * msm_rpm_request() - Creates a parent element to identify the
+ * resource on the RPM, that stores the KVPs for different fields modified
+ * for a hardware resource
+ *
+ * @set: if the device is setting the active/sleep set parameter
+ * for the resource
+ * @rsc_type: unsigned 32 bit integer that identifies the type of the resource
+ * @rsc_id: unsigned 32 bit that uniquely identifies a resource within a type
+ * @num_elements: number of KVPs pairs associated with the resource
+ *
+ * returns pointer to a msm_rpm_request on success, NULL on error
+ */
+struct msm_rpm_request *msm_rpm_create_request(
+		enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, int num_elements);
+
+/**
+ * msm_rpm_request_noirq() - Creates a parent element to identify the
+ * resource on the RPM, that stores the KVPs for different fields modified
+ * for a hardware resource. This function is similar to msm_rpm_create_request
+ * except that it has to be called with interrupts masked.
+ *
+ * @set: if the device is setting the active/sleep set parameter
+ * for the resource
+ * @rsc_type: unsigned 32 bit integer that identifies the type of the resource
+ * @rsc_id: unsigned 32 bit that uniquely identifies a resource within a type
+ * @num_elements: number of KVPs pairs associated with the resource
+ *
+ * returns pointer to a msm_rpm_request on success, NULL on error
+ */
+struct msm_rpm_request *msm_rpm_create_request_noirq(
+		enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, int num_elements);
+
+/**
+ * msm_rpm_add_kvp_data() - Adds a Key value pair to a existing RPM resource.
+ *
+ * @handle: RPM resource handle to which the data should be appended
+ * @key:  unsigned integer identify the parameter modified
+ * @data: byte array that contains the value corresponding to key.
+ * @size:   size of data in bytes.
+ *
+ * returns 0 on success or errno
+ */
+int msm_rpm_add_kvp_data(struct msm_rpm_request *handle,
+		uint32_t key, const uint8_t *data, int size);
+
+/**
+ * msm_rpm_add_kvp_data_noirq() - Adds a Key value pair to a existing RPM
+ * resource. This function is similar to msm_rpm_add_kvp_data except that it
+ * has to be called with interrupts masked.
+ *
+ * @handle: RPM resource handle to which the data should be appended
+ * @key:  unsigned integer identify the parameter modified
+ * @data: byte array that contains the value corresponding to key.
+ * @size:   size of data in bytes.
+ *
+ * returns 0 on success or errno
+ */
+int msm_rpm_add_kvp_data_noirq(struct msm_rpm_request *handle,
+		uint32_t key, const uint8_t *data, int size);
+
+/** msm_rpm_free_request() - clean up the RPM request handle created with
+ * msm_rpm_create_request
+ *
+ * @handle: RPM resource handle to be cleared.
+ */
+
+void msm_rpm_free_request(struct msm_rpm_request *handle);
+
+/**
+ * msm_rpm_send_request() - Send the RPM messages using SMD. The function
+ * assigns a message id before sending the data out to the RPM. RPM hardware
+ * uses the message id to acknowledge the messages.
+ *
+ * @handle: pointer to the msm_rpm_request for the resource being modified.
+ *
+ * returns non-zero message id on success and zero on a failed transaction.
+ * The drivers use message id to wait for ACK from RPM.
+ */
+int msm_rpm_send_request(struct msm_rpm_request *handle);
+
+/**
+ * msm_rpm_send_request_noirq() - Send the RPM messages using SMD. The
+ * function assigns a message id before sending the data out to the RPM.
+ * RPM hardware uses the message id to acknowledge the messages. This function
+ * is similar to msm_rpm_send_request except that it has to be called with
+ * interrupts masked.
+ *
+ * @handle: pointer to the msm_rpm_request for the resource being modified.
+ *
+ * returns non-zero message id on success and zero on a failed transaction.
+ * The drivers use message id to wait for ACK from RPM.
+ */
+int msm_rpm_send_request_noirq(struct msm_rpm_request *handle);
+
+/**
+ * msm_rpm_wait_for_ack() - A blocking call that waits for acknowledgment of
+ * a message from RPM.
+ *
+ * @msg_id: the return from msm_rpm_send_requests
+ *
+ * returns 0 on success or errno
+ */
+int msm_rpm_wait_for_ack(uint32_t msg_id);
+
+/**
+ * msm_rpm_wait_for_ack_noirq() - A blocking call that waits for acknowledgment
+ * of a message from RPM. This function is similar to msm_rpm_wait_for_ack
+ * except that it has to be called with interrupts masked.
+ *
+ * @msg_id: the return from msm_rpm_send_request
+ *
+ * returns 0 on success or errno
+ */
+int msm_rpm_wait_for_ack_noirq(uint32_t msg_id);
+
+/**
+ * msm_rpm_send_message() -Wrapper function for clients to send data given an
+ * array of key value pairs.
+ *
+ * @set: if the device is setting the active/sleep set parameter
+ * for the resource
+ * @rsc_type: unsigned 32 bit integer that identifies the type of the resource
+ * @rsc_id: unsigned 32 bit that uniquely identifies a resource within a type
+ * @kvp: array of KVP data.
+ * @nelem: number of KVPs pairs associated with the message.
+ *
+ * returns  0 on success and errno on failure.
+ */
+int msm_rpm_send_message(enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, struct msm_rpm_kvp *kvp, int nelems);
+
+/**
+ * msm_rpm_send_message_noirq() -Wrapper function for clients to send data
+ * given an array of key value pairs. This function is similar to the
+ * msm_rpm_send_message() except that it has to be called with interrupts
+ * disabled. Clients should choose the irq version when possible for system
+ * performance.
+ *
+ * @set: if the device is setting the active/sleep set parameter
+ * for the resource
+ * @rsc_type: unsigned 32 bit integer that identifies the type of the resource
+ * @rsc_id: unsigned 32 bit that uniquely identifies a resource within a type
+ * @kvp: array of KVP data.
+ * @nelem: number of KVPs pairs associated with the message.
+ *
+ * returns  0 on success and errno on failure.
+ */
+int msm_rpm_send_message_noirq(enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, struct msm_rpm_kvp *kvp, int nelems);
+
+/**
+ * msm_rpm_driver_init() - Initialization function that registers for a
+ * rpm platform driver.
+ *
+ * returns 0 on success.
+ */
+int __init msm_rpm_driver_init(void);
+
+#else
+
+static inline struct msm_rpm_request *msm_rpm_create_request(
+		enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, int num_elements)
+{
+	return NULL;
+}
+
+static inline struct msm_rpm_request *msm_rpm_create_request_noirq(
+		enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, int num_elements)
+{
+	return NULL;
+
+}
+static inline uint32_t msm_rpm_add_kvp_data(struct msm_rpm_request *handle,
+		uint32_t key, const uint8_t *data, int count)
+{
+	return 0;
+}
+static inline uint32_t msm_rpm_add_kvp_data_noirq(
+		struct msm_rpm_request *handle, uint32_t key,
+		const uint8_t *data, int count)
+{
+	return 0;
+}
+
+static inline void msm_rpm_free_request(struct msm_rpm_request *handle)
+{
+	return ;
+}
+
+static inline int msm_rpm_send_request(struct msm_rpm_request *handle)
+{
+	return 0;
+}
+
+static inline int msm_rpm_send_request_noirq(struct msm_rpm_request *handle)
+{
+	return 0;
+
+}
+static inline int msm_rpm_wait_for_ack(uint32_t msg_id)
+{
+	return 0;
+
+}
+static inline int msm_rpm_wait_for_ack_noirq(uint32_t msg_id)
+{
+	return 0;
+}
+
+static inline int __init msm_rpm_driver_init(void)
+{
+	return 0;
+}
+#endif
+#endif /*__ARCH_ARM_MACH_MSM_RPM_SMD_H*/
diff --git a/arch/arm/mach-msm/rpm-notifier.h b/arch/arm/mach-msm/rpm-notifier.h
new file mode 100644
index 0000000..df8d9b3
--- /dev/null
+++ b/arch/arm/mach-msm/rpm-notifier.h
@@ -0,0 +1,27 @@
+/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#ifndef __ARCH_ARM_MACH_MSM_RPM_NOTIF_H
+#define __ARCH_ARM_MACH_MSM_RPM_NOTIF_H
+
+struct msm_rpm_notifier_data {
+	uint32_t rsc_type;
+	uint32_t rsc_id;
+	uint32_t key;
+	uint32_t size;
+	uint8_t *value;
+};
+
+int msm_rpm_register_notifier(struct notifier_block *nb);
+int msm_rpm_unregister_notifier(struct notifier_block *nb);
+
+#endif /*__ARCH_ARM_MACH_MSM_RPM_NOTIF_H */
diff --git a/arch/arm/mach-msm/rpm-smd.c b/arch/arm/mach-msm/rpm-smd.c
new file mode 100644
index 0000000..75f4d92
--- /dev/null
+++ b/arch/arm/mach-msm/rpm-smd.c
@@ -0,0 +1,826 @@
+/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/bug.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include <linux/device.h>
+#include <linux/notifier.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <mach/socinfo.h>
+#include <mach/msm_smd.h>
+#include <mach/rpm-smd.h>
+#include "rpm-notifier.h"
+
+struct msm_rpm_driver_data {
+	const char *ch_name;
+	uint32_t ch_type;
+	smd_channel_t *ch_info;
+	struct work_struct work;
+	spinlock_t smd_lock_write;
+	spinlock_t smd_lock_read;
+	struct completion smd_open;
+};
+
+#define DEFAULT_BUFFER_SIZE 256
+#define GFP_FLAG(noirq) (noirq ? GFP_ATOMIC : GFP_KERNEL)
+#define INV_HDR "resource does not exist"
+#define ERR "err\0"
+#define MAX_ERR_BUFFER_SIZE 60
+
+static struct atomic_notifier_head msm_rpm_sleep_notifier;
+static bool standalone;
+
+int msm_rpm_register_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&msm_rpm_sleep_notifier, nb);
+}
+
+int msm_rpm_unregister_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_unregister(&msm_rpm_sleep_notifier, nb);
+}
+
+static struct workqueue_struct *msm_rpm_smd_wq;
+
+enum {
+	MSM_RPM_MSG_REQUEST_TYPE = 0,
+	MSM_RPM_MSG_TYPE_NR,
+};
+
+static const uint32_t msm_rpm_request_service[MSM_RPM_MSG_TYPE_NR] = {
+	0x716572, /* 'req\0' */
+};
+
+/*the order of fields matter and reflect the order expected by the RPM*/
+struct rpm_request_header {
+	uint32_t service_type;
+	uint32_t request_len;
+};
+
+struct rpm_message_header {
+	uint32_t msg_id;
+	enum msm_rpm_set set;
+	uint32_t resource_type;
+	uint32_t resource_id;
+	uint32_t data_len;
+};
+
+struct msm_rpm_kvp_data {
+	uint32_t key;
+	uint32_t nbytes; /* number of bytes */
+	uint8_t *value;
+	bool valid;
+};
+
+static atomic_t msm_rpm_msg_id = ATOMIC_INIT(0);
+
+static struct msm_rpm_driver_data msm_rpm_data;
+
+struct msm_rpm_request {
+	struct rpm_request_header req_hdr;
+	struct rpm_message_header msg_hdr;
+	struct msm_rpm_kvp_data *kvp;
+	uint32_t num_elements;
+	uint32_t write_idx;
+	uint8_t *buf;
+	uint32_t numbytes;
+};
+
+/*
+ * Data related to message acknowledgement
+ */
+
+LIST_HEAD(msm_rpm_wait_list);
+
+struct msm_rpm_wait_data {
+	struct list_head list;
+	uint32_t msg_id;
+	bool ack_recd;
+	int errno;
+	struct completion ack;
+};
+DEFINE_SPINLOCK(msm_rpm_list_lock);
+
+struct msm_rpm_ack_msg {
+	uint32_t req;
+	uint32_t req_len;
+	uint32_t rsc_id;
+	uint32_t msg_len;
+	uint32_t id_ack;
+};
+
+static int irq_process;
+
+LIST_HEAD(msm_rpm_ack_list);
+
+static void msm_rpm_notify_sleep_chain(struct rpm_message_header *hdr,
+		struct msm_rpm_kvp_data *kvp)
+{
+	struct msm_rpm_notifier_data notif;
+
+	notif.rsc_type = hdr->resource_type;
+	notif.rsc_id = hdr->resource_id;
+	notif.key = kvp->key;
+	notif.size = kvp->nbytes;
+	notif.value = kvp->value;
+	atomic_notifier_call_chain(&msm_rpm_sleep_notifier, 0, &notif);
+}
+
+static int msm_rpm_add_kvp_data_common(struct msm_rpm_request *handle,
+		uint32_t key, const uint8_t *data, int size, bool noirq)
+{
+	int i;
+	int data_size, msg_size;
+
+	if (!handle)
+		return -EINVAL;
+
+	data_size = ALIGN(size, SZ_4);
+	msg_size = data_size + sizeof(struct rpm_request_header);
+
+	for (i = 0; i < handle->write_idx; i++) {
+		if (handle->kvp[i].key != key)
+			continue;
+		if (handle->kvp[i].nbytes != data_size) {
+			kfree(handle->kvp[i].value);
+			handle->kvp[i].value = NULL;
+		} else {
+			if (!memcmp(handle->kvp[i].value, data, data_size))
+				return 0;
+		}
+		break;
+	}
+
+	if (i >= handle->num_elements)
+		return -ENOMEM;
+
+	if (i == handle->write_idx)
+		handle->write_idx++;
+
+	if (!handle->kvp[i].value) {
+		handle->kvp[i].value = kzalloc(data_size, GFP_FLAG(noirq));
+
+		if (!handle->kvp[i].value)
+			return -ENOMEM;
+	} else {
+		/* We enter the else case, if a key already exists but the
+		 * data doesn't match. In which case, we should zero the data
+		 * out.
+		 */
+		memset(handle->kvp[i].value, 0, data_size);
+	}
+
+	if (!handle->kvp[i].valid)
+		handle->msg_hdr.data_len += msg_size;
+	else
+		handle->msg_hdr.data_len += (data_size - handle->kvp[i].nbytes);
+
+	handle->kvp[i].nbytes = data_size;
+	handle->kvp[i].key = key;
+	memcpy(handle->kvp[i].value, data, size);
+	handle->kvp[i].valid = true;
+
+	if (handle->msg_hdr.set == MSM_RPM_CTX_SLEEP_SET)
+		msm_rpm_notify_sleep_chain(&handle->msg_hdr, &handle->kvp[i]);
+
+	return 0;
+
+}
+
+static struct msm_rpm_request *msm_rpm_create_request_common(
+		enum msm_rpm_set set, uint32_t rsc_type, uint32_t rsc_id,
+		int num_elements, bool noirq)
+{
+	struct msm_rpm_request *cdata;
+
+	cdata = kzalloc(sizeof(struct msm_rpm_request),
+			GFP_FLAG(noirq));
+
+	if (!cdata) {
+		printk(KERN_INFO"%s():Cannot allocate memory for client data\n",
+				__func__);
+		goto cdata_alloc_fail;
+	}
+
+	cdata->msg_hdr.set = set;
+	cdata->msg_hdr.resource_type = rsc_type;
+	cdata->msg_hdr.resource_id = rsc_id;
+	cdata->msg_hdr.data_len = 0;
+
+	cdata->num_elements = num_elements;
+	cdata->write_idx = 0;
+
+	cdata->kvp = kzalloc(sizeof(struct msm_rpm_kvp_data) * num_elements,
+			GFP_FLAG(noirq));
+
+	if (!cdata->kvp) {
+		pr_warn("%s(): Cannot allocate memory for key value data\n",
+				__func__);
+		goto kvp_alloc_fail;
+	}
+
+	cdata->buf = kzalloc(DEFAULT_BUFFER_SIZE, GFP_FLAG(noirq));
+
+	if (!cdata->buf)
+		goto buf_alloc_fail;
+
+	cdata->numbytes = DEFAULT_BUFFER_SIZE;
+	return cdata;
+
+buf_alloc_fail:
+	kfree(cdata->kvp);
+kvp_alloc_fail:
+	kfree(cdata);
+cdata_alloc_fail:
+	return NULL;
+
+}
+
+void msm_rpm_free_request(struct msm_rpm_request *handle)
+{
+	int i;
+
+	if (!handle)
+		return;
+	for (i = 0; i < handle->write_idx; i++)
+		kfree(handle->kvp[i].value);
+	kfree(handle->kvp);
+	kfree(handle);
+}
+EXPORT_SYMBOL(msm_rpm_free_request);
+
+struct msm_rpm_request *msm_rpm_create_request(
+		enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, int num_elements)
+{
+	return msm_rpm_create_request_common(set, rsc_type, rsc_id,
+			num_elements, false);
+}
+EXPORT_SYMBOL(msm_rpm_create_request);
+
+struct msm_rpm_request *msm_rpm_create_request_noirq(
+		enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, int num_elements)
+{
+	return msm_rpm_create_request_common(set, rsc_type, rsc_id,
+			num_elements, true);
+}
+EXPORT_SYMBOL(msm_rpm_create_request_noirq);
+
+int msm_rpm_add_kvp_data(struct msm_rpm_request *handle,
+		uint32_t key, const uint8_t *data, int size)
+{
+	return msm_rpm_add_kvp_data_common(handle, key, data, size, false);
+
+}
+EXPORT_SYMBOL(msm_rpm_add_kvp_data);
+
+int msm_rpm_add_kvp_data_noirq(struct msm_rpm_request *handle,
+		uint32_t key, const uint8_t *data, int size)
+{
+	return msm_rpm_add_kvp_data_common(handle, key, data, size, true);
+}
+EXPORT_SYMBOL(msm_rpm_add_kvp_data_noirq);
+
+/* Runs in interrupt context */
+static void msm_rpm_notify(void *data, unsigned event)
+{
+	struct msm_rpm_driver_data *pdata = (struct msm_rpm_driver_data *)data;
+	BUG_ON(!pdata);
+
+	if (!(pdata->ch_info))
+		return;
+
+	switch (event) {
+	case SMD_EVENT_DATA:
+		queue_work(msm_rpm_smd_wq, &pdata->work);
+		break;
+	case SMD_EVENT_OPEN:
+		complete(&pdata->smd_open);
+		break;
+	case SMD_EVENT_CLOSE:
+	case SMD_EVENT_STATUS:
+	case SMD_EVENT_REOPEN_READY:
+		break;
+	default:
+		pr_info("Unknown SMD event\n");
+
+	}
+}
+
+static struct msm_rpm_wait_data *msm_rpm_get_entry_from_msg_id(uint32_t msg_id)
+{
+	struct list_head *ptr;
+	struct msm_rpm_wait_data *elem;
+	unsigned long flags;
+
+	spin_lock_irqsave(&msm_rpm_list_lock, flags);
+
+	list_for_each(ptr, &msm_rpm_wait_list) {
+		elem = list_entry(ptr, struct msm_rpm_wait_data, list);
+		if (elem && (elem->msg_id == msg_id))
+			break;
+		elem = NULL;
+	}
+	spin_unlock_irqrestore(&msm_rpm_list_lock, flags);
+	return elem;
+}
+
+static int msm_rpm_get_next_msg_id(void)
+{
+	int id;
+
+	do {
+		id = atomic_inc_return(&msm_rpm_msg_id);
+	} while ((id == 0) || msm_rpm_get_entry_from_msg_id(id));
+
+	return id;
+}
+
+static int msm_rpm_add_wait_list(uint32_t msg_id)
+{
+	unsigned long flags;
+	struct msm_rpm_wait_data *data =
+		kzalloc(sizeof(struct msm_rpm_wait_data), GFP_ATOMIC);
+
+	if (!data)
+		return -ENOMEM;
+
+	init_completion(&data->ack);
+	data->ack_recd = false;
+	data->msg_id = msg_id;
+	spin_lock_irqsave(&msm_rpm_list_lock, flags);
+	list_add(&data->list, &msm_rpm_wait_list);
+	spin_unlock_irqrestore(&msm_rpm_list_lock, flags);
+
+	return 0;
+}
+
+static void msm_rpm_free_list_entry(struct msm_rpm_wait_data *elem)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&msm_rpm_list_lock, flags);
+	list_del(&elem->list);
+	spin_unlock_irqrestore(&msm_rpm_list_lock, flags);
+	kfree(elem);
+}
+
+static void msm_rpm_process_ack(uint32_t msg_id, int errno)
+{
+	struct list_head *ptr;
+	struct msm_rpm_wait_data *elem;
+	unsigned long flags;
+
+	spin_lock_irqsave(&msm_rpm_list_lock, flags);
+
+	list_for_each(ptr, &msm_rpm_wait_list) {
+		elem = list_entry(ptr, struct msm_rpm_wait_data, list);
+		if (elem && (elem->msg_id == msg_id)) {
+			elem->errno = errno;
+			elem->ack_recd = true;
+			complete(&elem->ack);
+			break;
+		}
+		elem = NULL;
+	}
+	WARN_ON(!elem);
+
+	spin_unlock_irqrestore(&msm_rpm_list_lock, flags);
+}
+
+struct msm_rpm_kvp_packet {
+	uint32_t id;
+	uint32_t len;
+	uint32_t val;
+};
+
+static inline uint32_t msm_rpm_get_msg_id_from_ack(uint8_t *buf)
+{
+	return ((struct msm_rpm_ack_msg *)buf)->id_ack;
+}
+
+static inline int msm_rpm_get_error_from_ack(uint8_t *buf)
+{
+	uint8_t *tmp;
+	uint32_t req_len = ((struct msm_rpm_ack_msg *)buf)->req_len;
+
+	int rc = -ENODEV;
+
+	req_len -= sizeof(struct msm_rpm_ack_msg);
+	req_len += 2 * sizeof(uint32_t);
+	if (!req_len)
+		return 0;
+
+	tmp = buf + sizeof(struct msm_rpm_ack_msg);
+
+	BUG_ON(memcmp(tmp, ERR, sizeof(uint32_t)));
+
+	tmp += 2 * sizeof(uint32_t);
+
+	if (!(memcmp(tmp, INV_HDR, min(req_len, sizeof(INV_HDR))-1)))
+		rc = -EINVAL;
+
+	return rc;
+}
+
+static void msm_rpm_read_smd_data(char *buf)
+{
+	int pkt_sz;
+	int bytes_read = 0;
+
+	pkt_sz = smd_cur_packet_size(msm_rpm_data.ch_info);
+
+	BUG_ON(pkt_sz > MAX_ERR_BUFFER_SIZE);
+
+	if (pkt_sz != smd_read_avail(msm_rpm_data.ch_info))
+		return;
+
+	BUG_ON(pkt_sz == 0);
+
+	do {
+		int len;
+
+		len = smd_read(msm_rpm_data.ch_info, buf + bytes_read, pkt_sz);
+		pkt_sz -= len;
+		bytes_read += len;
+
+	} while (pkt_sz > 0);
+
+	BUG_ON(pkt_sz < 0);
+}
+
+static void msm_rpm_smd_work(struct work_struct *work)
+{
+	uint32_t msg_id;
+	int errno;
+	char buf[MAX_ERR_BUFFER_SIZE] = {0};
+	unsigned long flags;
+
+	while (smd_is_pkt_avail(msm_rpm_data.ch_info) && !irq_process) {
+		spin_lock_irqsave(&msm_rpm_data.smd_lock_read, flags);
+		msm_rpm_read_smd_data(buf);
+		spin_unlock_irqrestore(&msm_rpm_data.smd_lock_read, flags);
+		msg_id = msm_rpm_get_msg_id_from_ack(buf);
+		errno = msm_rpm_get_error_from_ack(buf);
+		msm_rpm_process_ack(msg_id, errno);
+	}
+}
+
+static int msm_rpm_send_data(struct msm_rpm_request *cdata,
+		int msg_type, bool noirq)
+{
+	uint8_t *tmpbuff;
+	int i, ret, msg_size;
+	unsigned long flags;
+
+	int req_hdr_sz, msg_hdr_sz;
+
+	if (!cdata->msg_hdr.data_len)
+		return 0;
+	req_hdr_sz = sizeof(cdata->req_hdr);
+	msg_hdr_sz = sizeof(cdata->msg_hdr);
+
+	cdata->req_hdr.service_type = msm_rpm_request_service[msg_type];
+
+	cdata->msg_hdr.msg_id = msm_rpm_get_next_msg_id();
+
+	cdata->req_hdr.request_len = cdata->msg_hdr.data_len + msg_hdr_sz;
+	msg_size = cdata->req_hdr.request_len + req_hdr_sz;
+
+	/* populate data_len */
+	if (msg_size > cdata->numbytes) {
+		kfree(cdata->buf);
+		cdata->numbytes = msg_size;
+		cdata->buf = kzalloc(msg_size, GFP_FLAG(noirq));
+	}
+
+	if (!cdata->buf)
+		return 0;
+
+	tmpbuff = cdata->buf;
+
+	memcpy(tmpbuff, &cdata->req_hdr, req_hdr_sz + msg_hdr_sz);
+
+	tmpbuff += req_hdr_sz + msg_hdr_sz;
+
+	for (i = 0; (i < cdata->write_idx); i++) {
+		/* Sanity check */
+		BUG_ON((tmpbuff - cdata->buf) > cdata->numbytes);
+
+		if (!cdata->kvp[i].valid)
+			continue;
+
+		memcpy(tmpbuff, &cdata->kvp[i].key, sizeof(uint32_t));
+		tmpbuff += sizeof(uint32_t);
+
+		memcpy(tmpbuff, &cdata->kvp[i].nbytes, sizeof(uint32_t));
+		tmpbuff += sizeof(uint32_t);
+
+		memcpy(tmpbuff, cdata->kvp[i].value, cdata->kvp[i].nbytes);
+		tmpbuff += cdata->kvp[i].nbytes;
+	}
+
+	if (standalone) {
+		for (i = 0; (i < cdata->write_idx); i++)
+			cdata->kvp[i].valid = false;
+
+		cdata->msg_hdr.data_len = 0;
+		ret = cdata->msg_hdr.msg_id;
+		return ret;
+	}
+
+	msm_rpm_add_wait_list(cdata->msg_hdr.msg_id);
+
+	spin_lock_irqsave(&msm_rpm_data.smd_lock_write, flags);
+
+	ret = smd_write_avail(msm_rpm_data.ch_info);
+
+	if (ret < 0) {
+		pr_warn("%s(): SMD not initialized\n", __func__);
+		spin_unlock_irqrestore(&msm_rpm_data.smd_lock_write, flags);
+		return 0;
+	}
+
+	while ((ret < msg_size)) {
+		if (!noirq) {
+			spin_unlock_irqrestore(&msm_rpm_data.smd_lock_write,
+					flags);
+			cpu_relax();
+			spin_lock_irqsave(&msm_rpm_data.smd_lock_write, flags);
+		} else
+			udelay(5);
+		ret = smd_write_avail(msm_rpm_data.ch_info);
+	}
+
+	ret = smd_write(msm_rpm_data.ch_info, &cdata->buf[0], msg_size);
+	spin_unlock_irqrestore(&msm_rpm_data.smd_lock_write, flags);
+
+	if (ret == msg_size) {
+		for (i = 0; (i < cdata->write_idx); i++)
+			cdata->kvp[i].valid = false;
+		cdata->msg_hdr.data_len = 0;
+		ret = cdata->msg_hdr.msg_id;
+	} else if (ret < msg_size) {
+		struct msm_rpm_wait_data *rc;
+		ret = 0;
+		pr_info("Failed to write data msg_size:%d ret:%d\n",
+				msg_size, ret);
+		rc = msm_rpm_get_entry_from_msg_id(cdata->msg_hdr.msg_id);
+		if (rc)
+			msm_rpm_free_list_entry(rc);
+	}
+	return ret;
+}
+
+int msm_rpm_send_request(struct msm_rpm_request *handle)
+{
+	return msm_rpm_send_data(handle, MSM_RPM_MSG_REQUEST_TYPE, false);
+}
+EXPORT_SYMBOL(msm_rpm_send_request);
+
+int msm_rpm_send_request_noirq(struct msm_rpm_request *handle)
+{
+	return msm_rpm_send_data(handle, MSM_RPM_MSG_REQUEST_TYPE, true);
+}
+EXPORT_SYMBOL(msm_rpm_send_request_noirq);
+
+int msm_rpm_wait_for_ack(uint32_t msg_id)
+{
+	struct msm_rpm_wait_data *elem;
+	int rc = 0;
+
+	if (!msg_id)
+		return -EINVAL;
+
+	if (standalone)
+		return 0;
+
+	elem = msm_rpm_get_entry_from_msg_id(msg_id);
+	if (!elem)
+		return 0;
+
+	rc = wait_for_completion_timeout(&elem->ack, msecs_to_jiffies(1));
+	if (!rc) {
+		pr_warn("%s(): Timed out after 1 ms\n", __func__);
+		rc = -ETIMEDOUT;
+	} else {
+		rc = elem->errno;
+		msm_rpm_free_list_entry(elem);
+	}
+	return rc;
+}
+EXPORT_SYMBOL(msm_rpm_wait_for_ack);
+
+int msm_rpm_wait_for_ack_noirq(uint32_t msg_id)
+{
+	struct msm_rpm_wait_data *elem;
+	unsigned long flags;
+	int rc = 0;
+	uint32_t id = 0;
+	int count = 0;
+
+	if (!msg_id)
+		return -EINVAL;
+
+	if (standalone)
+		return 0;
+
+	spin_lock_irqsave(&msm_rpm_data.smd_lock_read, flags);
+	irq_process = true;
+
+	elem = msm_rpm_get_entry_from_msg_id(msg_id);
+
+	if (!elem)
+		/* Should this be a bug
+		 * Is it ok for another thread to read the msg?
+		 */
+		goto wait_ack_cleanup;
+
+	while ((id != msg_id) && (count++ < 10)) {
+		if (smd_is_pkt_avail(msm_rpm_data.ch_info)) {
+			int errno;
+			char buf[MAX_ERR_BUFFER_SIZE] = {};
+
+			msm_rpm_read_smd_data(buf);
+			id = msm_rpm_get_msg_id_from_ack(buf);
+			errno = msm_rpm_get_error_from_ack(buf);
+			msm_rpm_process_ack(id, errno);
+		} else
+			udelay(100);
+	}
+
+	if (count == 10) {
+		rc = -ETIMEDOUT;
+		pr_warn("%s(): Timed out after 1ms\n", __func__);
+	} else {
+		rc = elem->errno;
+		msm_rpm_free_list_entry(elem);
+	}
+wait_ack_cleanup:
+	irq_process = false;
+	spin_unlock_irqrestore(&msm_rpm_data.smd_lock_read, flags);
+	return rc;
+}
+EXPORT_SYMBOL(msm_rpm_wait_for_ack_noirq);
+
+int msm_rpm_send_message(enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, struct msm_rpm_kvp *kvp, int nelems)
+{
+	int i, rc;
+	struct msm_rpm_request *req =
+		msm_rpm_create_request(set, rsc_type, rsc_id, nelems);
+	if (!req)
+		return -ENOMEM;
+
+	for (i = 0; i < nelems; i++) {
+		rc = msm_rpm_add_kvp_data(req, kvp[i].key,
+				kvp[i].data, kvp[i].length);
+		if (rc)
+			goto bail;
+	}
+
+	rc = msm_rpm_wait_for_ack(msm_rpm_send_request(req));
+bail:
+	msm_rpm_free_request(req);
+	return rc;
+}
+EXPORT_SYMBOL(msm_rpm_send_message);
+
+int msm_rpm_send_message_noirq(enum msm_rpm_set set, uint32_t rsc_type,
+		uint32_t rsc_id, struct msm_rpm_kvp *kvp, int nelems)
+{
+	int i, rc;
+	struct msm_rpm_request *req =
+		msm_rpm_create_request_noirq(set, rsc_type, rsc_id, nelems);
+	if (!req)
+		return -ENOMEM;
+
+	for (i = 0; i < nelems; i++) {
+		rc = msm_rpm_add_kvp_data_noirq(req, kvp[i].key,
+					kvp[i].data, kvp[i].length);
+		if (rc)
+			goto bail;
+	}
+
+	rc = msm_rpm_wait_for_ack_noirq(msm_rpm_send_request_noirq(req));
+bail:
+	msm_rpm_free_request(req);
+	return rc;
+}
+EXPORT_SYMBOL(msm_rpm_send_message_noirq);
+static bool msm_rpm_set_standalone(void)
+{
+	if (machine_is_copper()) {
+		pr_warn("%s(): Running in standalone mode, requests "
+				"will not be sent to RPM\n", __func__);
+		standalone = true;
+	}
+	return standalone;
+}
+
+static int __devinit msm_rpm_dev_probe(struct platform_device *pdev)
+{
+	char *key = NULL;
+	int ret;
+
+	key = "rpm-channel-name";
+	ret = of_property_read_string(pdev->dev.of_node, key,
+					&msm_rpm_data.ch_name);
+	if (ret)
+		goto fail;
+
+	key = "rpm-channel-type";
+	ret = of_property_read_u32(pdev->dev.of_node, key,
+					&msm_rpm_data.ch_type);
+	if (ret)
+		goto fail;
+
+	init_completion(&msm_rpm_data.smd_open);
+	spin_lock_init(&msm_rpm_data.smd_lock_write);
+	spin_lock_init(&msm_rpm_data.smd_lock_read);
+	INIT_WORK(&msm_rpm_data.work, msm_rpm_smd_work);
+
+	if (smd_named_open_on_edge(msm_rpm_data.ch_name, msm_rpm_data.ch_type,
+				&msm_rpm_data.ch_info, &msm_rpm_data,
+				msm_rpm_notify)) {
+		pr_info("Cannot open RPM channel %s %d\n", msm_rpm_data.ch_name,
+				msm_rpm_data.ch_type);
+
+		msm_rpm_set_standalone();
+		BUG_ON(!standalone);
+		complete(&msm_rpm_data.smd_open);
+	}
+
+	ret = wait_for_completion_timeout(&msm_rpm_data.smd_open,
+			msecs_to_jiffies(5));
+
+	BUG_ON(!ret);
+
+	smd_disable_read_intr(msm_rpm_data.ch_info);
+
+	if (!standalone) {
+		msm_rpm_smd_wq = create_singlethread_workqueue("rpm-smd");
+		if (!msm_rpm_smd_wq)
+			return -EINVAL;
+	}
+
+	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
+	return 0;
+fail:
+	pr_err("%s(): Failed to read node: %s, key=%s\n", __func__,
+			pdev->dev.of_node->full_name, key);
+	return -EINVAL;
+}
+
+static struct of_device_id msm_rpm_match_table[] =  {
+	{.compatible = "qcom,rpm-smd"},
+	{},
+};
+
+static struct platform_driver msm_rpm_device_driver = {
+	.probe = msm_rpm_dev_probe,
+	.driver = {
+		.name = "rpm-smd",
+		.owner = THIS_MODULE,
+		.of_match_table = msm_rpm_match_table,
+	},
+};
+
+int __init msm_rpm_driver_init(void)
+{
+	static bool registered;
+
+	if (registered)
+		return 0;
+	registered = true;
+
+	return platform_driver_register(&msm_rpm_device_driver);
+}
+EXPORT_SYMBOL(msm_rpm_driver_init);
+late_initcall(msm_rpm_driver_init);
diff --git a/block/blk-core.c b/block/blk-core.c
index 35ae52d..a6a8ccb 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1467,7 +1467,7 @@
 			goto end_io;
 		}
 
-		if (unlikely(!(bio->bi_rw & REQ_DISCARD) &&
+		if (unlikely(!(bio->bi_rw & (REQ_DISCARD | REQ_SANITIZE)) &&
 			     nr_sectors > queue_max_hw_sectors(q))) {
 			printk(KERN_ERR "bio too big device %s (%u > %u)\n",
 			       bdevname(bio->bi_bdev, b),
@@ -1521,6 +1521,14 @@
 			goto end_io;
 		}
 
+		if ((bio->bi_rw & REQ_SANITIZE) &&
+		    (!blk_queue_sanitize(q))) {
+			pr_info("%s - got a SANITIZE request but the queue "
+			       "doesn't support sanitize requests", __func__);
+			err = -EOPNOTSUPP;
+			goto end_io;
+		}
+
 		if (blk_throtl_bio(q, &bio))
 			goto end_io;
 
@@ -1611,7 +1619,8 @@
 	 * If it's a regular read/write or a barrier with data attached,
 	 * go through the normal accounting stuff before submission.
 	 */
-	if (bio_has_data(bio) && !(rw & REQ_DISCARD)) {
+	if (bio_has_data(bio) &&
+	    (!(rw & (REQ_DISCARD | REQ_SANITIZE)))) {
 		if (rw & WRITE) {
 			count_vm_events(PGPGOUT, count);
 		} else {
@@ -1657,7 +1666,7 @@
  */
 int blk_rq_check_limits(struct request_queue *q, struct request *rq)
 {
-	if (rq->cmd_flags & REQ_DISCARD)
+	if (rq->cmd_flags & (REQ_DISCARD | REQ_SANITIZE))
 		return 0;
 
 	if (blk_rq_sectors(rq) > queue_max_sectors(q) ||
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 78e627e..39a7f25 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -112,6 +112,57 @@
 EXPORT_SYMBOL(blkdev_issue_discard);
 
 /**
+ * blkdev_issue_sanitize - queue a sanitize request
+ * @bdev:	blockdev to issue sanitize for
+ * @gfp_mask:	memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ *    Issue a sanitize request for the specified block device
+ */
+int blkdev_issue_sanitize(struct block_device *bdev, gfp_t gfp_mask)
+{
+	DECLARE_COMPLETION_ONSTACK(wait);
+	struct request_queue *q = bdev_get_queue(bdev);
+	int type = REQ_WRITE | REQ_SANITIZE;
+	struct bio_batch bb;
+	struct bio *bio;
+	int ret = 0;
+
+	if (!q)
+		return -ENXIO;
+
+	if (!blk_queue_sanitize(q)) {
+		pr_err("%s - card doesn't support sanitize", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	bio = bio_alloc(gfp_mask, 1);
+	if (!bio)
+		return -ENOMEM;
+
+	atomic_set(&bb.done, 1);
+	bb.flags = 1 << BIO_UPTODATE;
+	bb.wait = &wait;
+
+	bio->bi_end_io = bio_batch_end_io;
+	bio->bi_bdev = bdev;
+	bio->bi_private = &bb;
+
+	atomic_inc(&bb.done);
+	submit_bio(type, bio);
+
+	/* Wait for bios in-flight */
+	if (!atomic_dec_and_test(&bb.done))
+		wait_for_completion(&wait);
+
+	if (!test_bit(BIO_UPTODATE, &bb.flags))
+		ret = -EIO;
+
+	return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_sanitize);
+
+/**
  * blkdev_issue_zeroout - generate number of zero filed write bios
  * @bdev:	blockdev to issue
  * @sector:	start sector
diff --git a/block/blk-merge.c b/block/blk-merge.c
index cfcc37c..f3ed15b 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -383,6 +383,12 @@
 		return 0;
 
 	/*
+	 * Don't merge file system requests and sanitize requests
+	 */
+	if ((req->cmd_flags & REQ_SANITIZE) != (next->cmd_flags & REQ_SANITIZE))
+		return 0;
+
+	/*
 	 * not contiguous
 	 */
 	if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
diff --git a/block/elevator.c b/block/elevator.c
index b0b38ce..78a14b5 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -89,6 +89,12 @@
 		return 0;
 
 	/*
+	 * Don't merge sanitize requests
+	 */
+	if ((bio->bi_rw & REQ_SANITIZE) != (rq->bio->bi_rw & REQ_SANITIZE))
+		return 0;
+
+	/*
 	 * different data direction or already started, don't merge
 	 */
 	if (bio_data_dir(bio) != rq_data_dir(rq))
@@ -657,7 +663,7 @@
 	if (rq->cmd_flags & REQ_SOFTBARRIER) {
 		/* barriers are scheduling boundary, update end_sector */
 		if (rq->cmd_type == REQ_TYPE_FS ||
-		    (rq->cmd_flags & REQ_DISCARD)) {
+		    (rq->cmd_flags & (REQ_DISCARD | REQ_SANITIZE))) {
 			q->end_sector = rq_end_sector(rq);
 			q->boundary_rq = rq;
 		}
diff --git a/block/ioctl.c b/block/ioctl.c
index 1124cd2..dbc103b 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -131,6 +131,11 @@
 	return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
 }
 
+static int blk_ioctl_sanitize(struct block_device *bdev)
+{
+	return blkdev_issue_sanitize(bdev, GFP_KERNEL);
+}
+
 static int put_ushort(unsigned long arg, unsigned short val)
 {
 	return put_user(val, (unsigned short __user *)arg);
@@ -215,6 +220,10 @@
 		set_device_ro(bdev, n);
 		return 0;
 
+	case BLKSANITIZE:
+		ret = blk_ioctl_sanitize(bdev);
+		break;
+
 	case BLKDISCARD:
 	case BLKSECDISCARD: {
 		uint64_t range[2];
diff --git a/drivers/tty/Kconfig b/drivers/tty/Kconfig
index bd7cc05..ae5a62c 100644
--- a/drivers/tty/Kconfig
+++ b/drivers/tty/Kconfig
@@ -319,6 +319,25 @@
 	  This line discipline provides support for the GSM MUX protocol and
 	  presents the mux as a set of 61 individual tty devices.
 
+config N_SMUX
+	tristate "SMUX line discipline support"
+	depends on NET && SERIAL_MSM_HS
+	help
+	  This line discipline provides support for the Serial MUX protocol
+	  and provides a TTY and kernel API for multiple logical channels.
+
+config N_SMUX_LOOPBACK
+	tristate "SMUX line discipline loopback support"
+	depends on N_SMUX
+	help
+	  Provides loopback and unit testing support for the Serial MUX Protocol.
+
+config SMUX_CTL
+	tristate "SMUX control driver"
+	depends on N_SMUX
+	help
+	  Support for SMUX control driver on top of serial MUX.
+
 config TRACE_ROUTER
 	tristate "Trace data router for MIPI P1149.7 cJTAG standard"
 	depends on TRACE_SINK
diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index ea89b0b..3078e8d 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -6,6 +6,9 @@
 obj-$(CONFIG_MAGIC_SYSRQ)	+= sysrq.o
 obj-$(CONFIG_N_HDLC)		+= n_hdlc.o
 obj-$(CONFIG_N_GSM)		+= n_gsm.o
+obj-$(CONFIG_N_SMUX)		+= n_smux.o
+obj-$(CONFIG_N_SMUX_LOOPBACK)	+= smux_test.o smux_loopback.o
+obj-$(CONFIG_SMUX_CTL)		+= smux_ctl.o
 obj-$(CONFIG_TRACE_ROUTER)	+= n_tracerouter.o
 obj-$(CONFIG_TRACE_SINK)	+= n_tracesink.o
 obj-$(CONFIG_R3964)		+= n_r3964.o
diff --git a/drivers/tty/n_smux.c b/drivers/tty/n_smux.c
new file mode 100644
index 0000000..7ba54fe
--- /dev/null
+++ b/drivers/tty/n_smux.c
@@ -0,0 +1,2938 @@
+/* drivers/tty/n_smux.c
+ *
+ * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/tty_driver.h>
+#include <linux/smux.h>
+#include <linux/list.h>
+#include <linux/kfifo.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <mach/msm_serial_hs.h>
+#include "smux_private.h"
+#include "smux_loopback.h"
+
+#define SMUX_NOTIFY_FIFO_SIZE	128
+#define SMUX_TX_QUEUE_SIZE	256
+#define SMUX_GET_RX_BUFF_MAX_RETRY_CNT 2
+#define SMUX_WM_LOW 2
+#define SMUX_WM_HIGH 4
+#define SMUX_PKT_LOG_SIZE 80
+
+/* Maximum size we can accept in a single RX buffer */
+#define TTY_RECEIVE_ROOM 65536
+#define TTY_BUFFER_FULL_WAIT_MS 50
+
+/* maximum sleep time between wakeup attempts */
+#define SMUX_WAKEUP_DELAY_MAX (1 << 20)
+
+/* minimum delay for scheduling delayed work */
+#define SMUX_WAKEUP_DELAY_MIN (1 << 15)
+
+/* inactivity timeout for no rx/tx activity */
+#define SMUX_INACTIVITY_TIMEOUT_MS 1000
+
+enum {
+	MSM_SMUX_DEBUG = 1U << 0,
+	MSM_SMUX_INFO = 1U << 1,
+	MSM_SMUX_POWER_INFO = 1U << 2,
+	MSM_SMUX_PKT = 1U << 3,
+};
+
+static int smux_debug_mask;
+module_param_named(debug_mask, smux_debug_mask,
+		   int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+/* Simulated wakeup used for testing */
+int smux_byte_loopback;
+module_param_named(byte_loopback, smux_byte_loopback,
+		   int, S_IRUGO | S_IWUSR | S_IWGRP);
+int smux_simulate_wakeup_delay = 1;
+module_param_named(simulate_wakeup_delay, smux_simulate_wakeup_delay,
+		   int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+#define SMUX_DBG(x...) do {                              \
+	if (smux_debug_mask & MSM_SMUX_DEBUG) \
+			pr_info(x);  \
+} while (0)
+
+#define SMUX_LOG_PKT_RX(pkt) do { \
+	if (smux_debug_mask & MSM_SMUX_PKT) \
+			smux_log_pkt(pkt, 1); \
+} while (0)
+
+#define SMUX_LOG_PKT_TX(pkt) do { \
+	if (smux_debug_mask & MSM_SMUX_PKT) \
+			smux_log_pkt(pkt, 0); \
+} while (0)
+
+/**
+ * Return true if channel is fully opened (both
+ * local and remote sides are in the OPENED state).
+ */
+#define IS_FULLY_OPENED(ch) \
+	(ch && (ch)->local_state == SMUX_LCH_LOCAL_OPENED \
+	 && (ch)->remote_state == SMUX_LCH_REMOTE_OPENED)
+
+static struct platform_device smux_devs[] = {
+	{.name = "SMUX_CTL", .id = -1},
+	{.name = "SMUX_RMNET", .id = -1},
+	{.name = "SMUX_DUN_DATA_HSUART", .id = 0},
+	{.name = "SMUX_RMNET_DATA_HSUART", .id = 1},
+	{.name = "SMUX_RMNET_CTL_HSUART", .id = 0},
+	{.name = "SMUX_DIAG", .id = -1},
+};
+
+enum {
+	SMUX_CMD_STATUS_RTC = 1 << 0,
+	SMUX_CMD_STATUS_RTR = 1 << 1,
+	SMUX_CMD_STATUS_RI = 1 << 2,
+	SMUX_CMD_STATUS_DCD = 1 << 3,
+	SMUX_CMD_STATUS_FLOW_CNTL = 1 << 4,
+};
+
+/* Channel mode */
+enum {
+	SMUX_LCH_MODE_NORMAL,
+	SMUX_LCH_MODE_LOCAL_LOOPBACK,
+	SMUX_LCH_MODE_REMOTE_LOOPBACK,
+};
+
+enum {
+	SMUX_RX_IDLE,
+	SMUX_RX_MAGIC,
+	SMUX_RX_HDR,
+	SMUX_RX_PAYLOAD,
+	SMUX_RX_FAILURE,
+};
+
+/**
+ * Power states.
+ *
+ * The _FLUSH states are internal transitional states and are not part of the
+ * official state machine.
+ */
+enum {
+	SMUX_PWR_OFF,
+	SMUX_PWR_TURNING_ON,
+	SMUX_PWR_ON,
+	SMUX_PWR_TURNING_OFF_FLUSH,
+	SMUX_PWR_TURNING_OFF,
+	SMUX_PWR_OFF_FLUSH,
+};
+
+/**
+ * Logical Channel Structure.  One instance per channel.
+ *
+ * Locking Hierarchy
+ * Each lock has a postfix that describes the locking level.  If multiple locks
+ * are required, only increasing lock hierarchy numbers may be locked which
+ * ensures avoiding a deadlock.
+ *
+ * Locking Example
+ * If state_lock_lhb1 is currently held and the TX list needs to be
+ * manipulated, then tx_lock_lhb2 may be locked since it's locking hierarchy
+ * is greater.  However, if tx_lock_lhb2 is held, then state_lock_lhb1 may
+ * not be acquired since it would result in a deadlock.
+ *
+ * Note that the Line Discipline locks (*_lha) should always be acquired
+ * before the logical channel locks.
+ */
+struct smux_lch_t {
+	/* channel state */
+	spinlock_t state_lock_lhb1;
+	uint8_t lcid;
+	unsigned local_state;
+	unsigned local_mode;
+	uint8_t local_tiocm;
+
+	unsigned remote_state;
+	unsigned remote_mode;
+	uint8_t remote_tiocm;
+
+	int tx_flow_control;
+
+	/* client callbacks and private data */
+	void *priv;
+	void (*notify)(void *priv, int event_type, const void *metadata);
+	int (*get_rx_buffer)(void *priv, void **pkt_priv, void **buffer,
+								int size);
+
+	/* TX Info */
+	spinlock_t tx_lock_lhb2;
+	struct list_head tx_queue;
+	struct list_head tx_ready_list;
+	unsigned tx_pending_data_cnt;
+	unsigned notify_lwm;
+};
+
+union notifier_metadata {
+	struct smux_meta_disconnected disconnected;
+	struct smux_meta_read read;
+	struct smux_meta_write write;
+	struct smux_meta_tiocm tiocm;
+};
+
+struct smux_notify_handle {
+	void (*notify)(void *priv, int event_type, const void *metadata);
+	void *priv;
+	int event_type;
+	union notifier_metadata *metadata;
+};
+
+/**
+ * Line discipline and module structure.
+ *
+ * Only one instance since multiple instances of line discipline are not
+ * allowed.
+ */
+struct smux_ldisc_t {
+	spinlock_t lock_lha0;
+
+	int is_initialized;
+	int in_reset;
+	int ld_open_count;
+	struct tty_struct *tty;
+
+	/* RX State Machine */
+	spinlock_t rx_lock_lha1;
+	unsigned char recv_buf[SMUX_MAX_PKT_SIZE];
+	unsigned int recv_len;
+	unsigned int pkt_remain;
+	unsigned rx_state;
+	unsigned rx_activity_flag;
+
+	/* TX / Power */
+	spinlock_t tx_lock_lha2;
+	struct list_head lch_tx_ready_list;
+	unsigned power_state;
+	unsigned pwr_wakeup_delay_us;
+	unsigned tx_activity_flag;
+	unsigned powerdown_enabled;
+};
+
+
+/* data structures */
+static struct smux_lch_t smux_lch[SMUX_NUM_LOGICAL_CHANNELS];
+static struct smux_ldisc_t smux;
+static const char *tty_error_type[] = {
+	[TTY_NORMAL] = "normal",
+	[TTY_OVERRUN] = "overrun",
+	[TTY_BREAK] = "break",
+	[TTY_PARITY] = "parity",
+	[TTY_FRAME] = "framing",
+};
+
+static const char *smux_cmds[] = {
+	[SMUX_CMD_DATA] = "DATA",
+	[SMUX_CMD_OPEN_LCH] = "OPEN",
+	[SMUX_CMD_CLOSE_LCH] = "CLOSE",
+	[SMUX_CMD_STATUS] = "STATUS",
+	[SMUX_CMD_PWR_CTL] = "PWR",
+	[SMUX_CMD_BYTE] = "Raw Byte",
+};
+
+static void smux_notify_local_fn(struct work_struct *work);
+static DECLARE_WORK(smux_notify_local, smux_notify_local_fn);
+
+static struct workqueue_struct *smux_notify_wq;
+static size_t handle_size;
+static struct kfifo smux_notify_fifo;
+static int queued_fifo_notifications;
+static DEFINE_SPINLOCK(notify_lock_lhc1);
+
+static struct workqueue_struct *smux_tx_wq;
+static void smux_tx_worker(struct work_struct *work);
+static DECLARE_WORK(smux_tx_work, smux_tx_worker);
+
+static void smux_wakeup_worker(struct work_struct *work);
+static DECLARE_WORK(smux_wakeup_work, smux_wakeup_worker);
+static DECLARE_DELAYED_WORK(smux_wakeup_delayed_work, smux_wakeup_worker);
+
+static void smux_inactivity_worker(struct work_struct *work);
+static DECLARE_WORK(smux_inactivity_work, smux_inactivity_worker);
+static DECLARE_DELAYED_WORK(smux_delayed_inactivity_work,
+		smux_inactivity_worker);
+
+static long msm_smux_tiocm_get_atomic(struct smux_lch_t *ch);
+static void list_channel(struct smux_lch_t *ch);
+static int smux_send_status_cmd(struct smux_lch_t *ch);
+static int smux_dispatch_rx_pkt(struct smux_pkt_t *pkt);
+
+/**
+ * Convert TTY Error Flags to string for logging purposes.
+ *
+ * @flag    TTY_* flag
+ * @returns String description or NULL if unknown
+ */
+static const char *tty_flag_to_str(unsigned flag)
+{
+	if (flag < ARRAY_SIZE(tty_error_type))
+		return tty_error_type[flag];
+	return NULL;
+}
+
+/**
+ * Convert SMUX Command to string for logging purposes.
+ *
+ * @cmd    SMUX command
+ * @returns String description or NULL if unknown
+ */
+static const char *cmd_to_str(unsigned cmd)
+{
+	if (cmd < ARRAY_SIZE(smux_cmds))
+		return smux_cmds[cmd];
+	return NULL;
+}
+
+/**
+ * Set the reset state due to an unrecoverable failure.
+ */
+static void smux_enter_reset(void)
+{
+	pr_err("%s: unrecoverable failure, waiting for ssr\n", __func__);
+	smux.in_reset = 1;
+}
+
+static int lch_init(void)
+{
+	unsigned int id;
+	struct smux_lch_t *ch;
+	int i = 0;
+
+	handle_size = sizeof(struct smux_notify_handle *);
+
+	smux_notify_wq = create_singlethread_workqueue("smux_notify_wq");
+	smux_tx_wq = create_singlethread_workqueue("smux_tx_wq");
+
+	if (IS_ERR(smux_notify_wq) || IS_ERR(smux_tx_wq)) {
+		SMUX_DBG("%s: create_singlethread_workqueue ENOMEM\n",
+							__func__);
+		return -ENOMEM;
+	}
+
+	i |= kfifo_alloc(&smux_notify_fifo,
+			SMUX_NOTIFY_FIFO_SIZE * handle_size,
+			GFP_KERNEL);
+	i |= smux_loopback_init();
+
+	if (i) {
+		pr_err("%s: out of memory error\n", __func__);
+		return -ENOMEM;
+	}
+
+	for (id = 0 ; id < SMUX_NUM_LOGICAL_CHANNELS; id++) {
+		ch = &smux_lch[id];
+
+		spin_lock_init(&ch->state_lock_lhb1);
+		ch->lcid = id;
+		ch->local_state = SMUX_LCH_LOCAL_CLOSED;
+		ch->local_mode = SMUX_LCH_MODE_NORMAL;
+		ch->local_tiocm = 0x0;
+		ch->remote_state = SMUX_LCH_REMOTE_CLOSED;
+		ch->remote_mode = SMUX_LCH_MODE_NORMAL;
+		ch->remote_tiocm = 0x0;
+		ch->tx_flow_control = 0;
+		ch->priv = 0;
+		ch->notify = 0;
+		ch->get_rx_buffer = 0;
+
+		spin_lock_init(&ch->tx_lock_lhb2);
+		INIT_LIST_HEAD(&ch->tx_queue);
+		INIT_LIST_HEAD(&ch->tx_ready_list);
+		ch->tx_pending_data_cnt = 0;
+		ch->notify_lwm = 0;
+	}
+
+	return 0;
+}
+
+int smux_assert_lch_id(uint32_t lcid)
+{
+	if (lcid >= SMUX_NUM_LOGICAL_CHANNELS)
+		return -ENXIO;
+	else
+		return 0;
+}
+
+/**
+ * Log packet information for debug purposes.
+ *
+ * @pkt     Packet to log
+ * @is_recv 1 = RX packet; 0 = TX Packet
+ *
+ * [DIR][LCID] [LOCAL_STATE][LOCAL_MODE]:[REMOTE_STATE][REMOTE_MODE] PKT Info
+ *
+ * PKT Info:
+ *   [CMD] flags [flags] len [PAYLOAD_LEN]:[PAD_LEN] [Payload hex bytes]
+ *
+ * Direction:  R = Receive, S = Send
+ * Local State:  C = Closed; c = closing; o = opening; O = Opened
+ * Local Mode: L = Local loopback; R = Remote loopback; N = Normal
+ * Remote State: C = Closed; O = Opened
+ * Remote Mode: R = Remote loopback; N = Normal
+ */
+static void smux_log_pkt(struct smux_pkt_t *pkt, int is_recv)
+{
+	char logbuf[SMUX_PKT_LOG_SIZE];
+	char cmd_extra[16];
+	int i = 0;
+	int count;
+	int len;
+	char local_state;
+	char local_mode;
+	char remote_state;
+	char remote_mode;
+	struct smux_lch_t *ch;
+	unsigned char *data;
+
+	ch = &smux_lch[pkt->hdr.lcid];
+
+	switch (ch->local_state) {
+	case SMUX_LCH_LOCAL_CLOSED:
+		local_state = 'C';
+		break;
+	case SMUX_LCH_LOCAL_OPENING:
+		local_state = 'o';
+		break;
+	case SMUX_LCH_LOCAL_OPENED:
+		local_state = 'O';
+		break;
+	case SMUX_LCH_LOCAL_CLOSING:
+		local_state = 'c';
+		break;
+	default:
+		local_state = 'U';
+		break;
+	}
+
+	switch (ch->local_mode) {
+	case SMUX_LCH_MODE_LOCAL_LOOPBACK:
+		local_mode = 'L';
+		break;
+	case SMUX_LCH_MODE_REMOTE_LOOPBACK:
+		local_mode = 'R';
+		break;
+	case SMUX_LCH_MODE_NORMAL:
+		local_mode = 'N';
+		break;
+	default:
+		local_mode = 'U';
+		break;
+	}
+
+	switch (ch->remote_state) {
+	case SMUX_LCH_REMOTE_CLOSED:
+		remote_state = 'C';
+		break;
+	case SMUX_LCH_REMOTE_OPENED:
+		remote_state = 'O';
+		break;
+
+	default:
+		remote_state = 'U';
+		break;
+	}
+
+	switch (ch->remote_mode) {
+	case SMUX_LCH_MODE_REMOTE_LOOPBACK:
+		remote_mode = 'R';
+		break;
+	case SMUX_LCH_MODE_NORMAL:
+		remote_mode = 'N';
+		break;
+	default:
+		remote_mode = 'U';
+		break;
+	}
+
+	/* determine command type (ACK, etc) */
+	cmd_extra[0] = '\0';
+	switch (pkt->hdr.cmd) {
+	case SMUX_CMD_OPEN_LCH:
+		if (pkt->hdr.flags & SMUX_CMD_OPEN_ACK)
+			snprintf(cmd_extra, sizeof(cmd_extra), " ACK");
+		break;
+	case SMUX_CMD_CLOSE_LCH:
+		if (pkt->hdr.flags & SMUX_CMD_CLOSE_ACK)
+			snprintf(cmd_extra, sizeof(cmd_extra), " ACK");
+		break;
+	};
+
+	i += snprintf(logbuf + i, SMUX_PKT_LOG_SIZE - i,
+			"smux: %c%d %c%c:%c%c %s%s flags %x len %d:%d ",
+			is_recv ? 'R' : 'S', pkt->hdr.lcid,
+			local_state, local_mode,
+			remote_state, remote_mode,
+			cmd_to_str(pkt->hdr.cmd), cmd_extra, pkt->hdr.flags,
+			pkt->hdr.payload_len, pkt->hdr.pad_len);
+
+	len = (pkt->hdr.payload_len > 16) ? 16 : pkt->hdr.payload_len;
+	data = (unsigned char *)pkt->payload;
+	for (count = 0; count < len; count++)
+		i += snprintf(logbuf + i, SMUX_PKT_LOG_SIZE - i,
+				"%02x ", (unsigned)data[count]);
+
+	pr_info("%s\n", logbuf);
+}
+
+static void smux_notify_local_fn(struct work_struct *work)
+{
+	struct smux_notify_handle *notify_handle = NULL;
+	union notifier_metadata *metadata = NULL;
+	unsigned long flags;
+	int i;
+
+	for (;;) {
+		/* retrieve notification */
+		spin_lock_irqsave(&notify_lock_lhc1, flags);
+		if (kfifo_len(&smux_notify_fifo) >= handle_size) {
+			i = kfifo_out(&smux_notify_fifo,
+				&notify_handle,
+				handle_size);
+		if (i != handle_size) {
+			pr_err("%s: unable to retrieve handle %d expected %d\n",
+					__func__, i, handle_size);
+			spin_unlock_irqrestore(&notify_lock_lhc1, flags);
+			break;
+			}
+		} else {
+			spin_unlock_irqrestore(&notify_lock_lhc1, flags);
+			break;
+		}
+		--queued_fifo_notifications;
+		spin_unlock_irqrestore(&notify_lock_lhc1, flags);
+
+		/* notify client */
+		metadata = notify_handle->metadata;
+		notify_handle->notify(notify_handle->priv,
+			notify_handle->event_type,
+			metadata);
+
+		kfree(metadata);
+		kfree(notify_handle);
+	}
+}
+
+/**
+ * Initialize existing packet.
+ */
+void smux_init_pkt(struct smux_pkt_t *pkt)
+{
+	memset(pkt, 0x0, sizeof(*pkt));
+	pkt->hdr.magic = SMUX_MAGIC;
+	INIT_LIST_HEAD(&pkt->list);
+}
+
+/**
+ * Allocate and initialize packet.
+ *
+ * If a payload is needed, either set it directly and ensure that it's freed or
+ * use smd_alloc_pkt_payload() to allocate a packet and it will be freed
+ * automatically when smd_free_pkt() is called.
+ */
+struct smux_pkt_t *smux_alloc_pkt(void)
+{
+	struct smux_pkt_t *pkt;
+
+	/* Consider a free list implementation instead of kmalloc */
+	pkt = kmalloc(sizeof(struct smux_pkt_t), GFP_ATOMIC);
+	if (!pkt) {
+		pr_err("%s: out of memory\n", __func__);
+		return NULL;
+	}
+	smux_init_pkt(pkt);
+	pkt->allocated = 1;
+
+	return pkt;
+}
+
+/**
+ * Free packet.
+ *
+ * @pkt Packet to free (may be NULL)
+ *
+ * If payload was allocated using smux_alloc_pkt_payload(), then it is freed as
+ * well.  Otherwise, the caller is responsible for freeing the payload.
+ */
+void smux_free_pkt(struct smux_pkt_t *pkt)
+{
+	if (pkt) {
+		if (pkt->free_payload)
+			kfree(pkt->payload);
+		if (pkt->allocated)
+			kfree(pkt);
+	}
+}
+
+/**
+ * Allocate packet payload.
+ *
+ * @pkt Packet to add payload to
+ *
+ * @returns 0 on success, <0 upon error
+ *
+ * A flag is set to signal smux_free_pkt() to free the payload.
+ */
+int smux_alloc_pkt_payload(struct smux_pkt_t *pkt)
+{
+	if (!pkt)
+		return -EINVAL;
+
+	pkt->payload = kmalloc(pkt->hdr.payload_len, GFP_ATOMIC);
+	pkt->free_payload = 1;
+	if (!pkt->payload) {
+		pr_err("%s: unable to malloc %d bytes for payload\n",
+				__func__, pkt->hdr.payload_len);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int schedule_notify(uint8_t lcid, int event,
+			const union notifier_metadata *metadata)
+{
+	struct smux_notify_handle *notify_handle = 0;
+	union notifier_metadata *meta_copy = 0;
+	struct smux_lch_t *ch;
+	int i;
+	unsigned long flags;
+	int ret = 0;
+
+	ch = &smux_lch[lcid];
+	notify_handle = kzalloc(sizeof(struct smux_notify_handle),
+						GFP_ATOMIC);
+	if (!notify_handle) {
+		pr_err("%s: out of memory\n", __func__);
+		ret = -ENOMEM;
+		goto free_out;
+	}
+
+	notify_handle->notify = ch->notify;
+	notify_handle->priv = ch->priv;
+	notify_handle->event_type = event;
+	if (metadata) {
+		meta_copy = kzalloc(sizeof(union notifier_metadata),
+							GFP_ATOMIC);
+		if (!meta_copy) {
+			pr_err("%s: out of memory\n", __func__);
+			ret = -ENOMEM;
+			goto free_out;
+		}
+		*meta_copy = *metadata;
+		notify_handle->metadata = meta_copy;
+	} else {
+		notify_handle->metadata = NULL;
+	}
+
+	spin_lock_irqsave(&notify_lock_lhc1, flags);
+	i = kfifo_avail(&smux_notify_fifo);
+	if (i < handle_size) {
+		pr_err("%s: fifo full error %d expected %d\n",
+					__func__, i, handle_size);
+		ret = -ENOMEM;
+		goto unlock_out;
+	}
+
+	i = kfifo_in(&smux_notify_fifo, &notify_handle, handle_size);
+	if (i < 0 || i != handle_size) {
+		pr_err("%s: fifo not available error %d (expected %d)\n",
+				__func__, i, handle_size);
+		ret = -ENOSPC;
+		goto unlock_out;
+	}
+	++queued_fifo_notifications;
+
+unlock_out:
+	spin_unlock_irqrestore(&notify_lock_lhc1, flags);
+
+free_out:
+	queue_work(smux_notify_wq, &smux_notify_local);
+	if (ret < 0 && notify_handle) {
+		kfree(notify_handle->metadata);
+		kfree(notify_handle);
+	}
+	return ret;
+}
+
+/**
+ * Returns the serialized size of a packet.
+ *
+ * @pkt Packet to serialize
+ *
+ * @returns Serialized length of packet
+ */
+static unsigned int smux_serialize_size(struct smux_pkt_t *pkt)
+{
+	unsigned int size;
+
+	size = sizeof(struct smux_hdr_t);
+	size += pkt->hdr.payload_len;
+	size += pkt->hdr.pad_len;
+
+	return size;
+}
+
+/**
+ * Serialize packet @pkt into output buffer @data.
+ *
+ * @pkt		Packet to serialize
+ * @out     Destination buffer pointer
+ * @out_len	Size of serialized packet
+ *
+ * @returns 0 for success
+ */
+int smux_serialize(struct smux_pkt_t *pkt, char *out,
+					unsigned int *out_len)
+{
+	char *data_start = out;
+
+	if (smux_serialize_size(pkt) > SMUX_MAX_PKT_SIZE) {
+		pr_err("%s: packet size %d too big\n",
+				__func__, smux_serialize_size(pkt));
+		return -E2BIG;
+	}
+
+	memcpy(out, &pkt->hdr, sizeof(struct smux_hdr_t));
+	out += sizeof(struct smux_hdr_t);
+	if (pkt->payload) {
+		memcpy(out, pkt->payload, pkt->hdr.payload_len);
+		out += pkt->hdr.payload_len;
+	}
+	if (pkt->hdr.pad_len) {
+		memset(out, 0x0,  pkt->hdr.pad_len);
+		out += pkt->hdr.pad_len;
+	}
+	*out_len = out - data_start;
+	return 0;
+}
+
+/**
+ * Serialize header and provide pointer to the data.
+ *
+ * @pkt             Packet
+ * @out[out]        Pointer to the serialized header data
+ * @out_len[out]    Pointer to the serialized header length
+ */
+static void smux_serialize_hdr(struct smux_pkt_t *pkt, char **out,
+					unsigned int *out_len)
+{
+	*out = (char *)&pkt->hdr;
+	*out_len = sizeof(struct smux_hdr_t);
+}
+
+/**
+ * Serialize payload and provide pointer to the data.
+ *
+ * @pkt             Packet
+ * @out[out]        Pointer to the serialized payload data
+ * @out_len[out]    Pointer to the serialized payload length
+ */
+static void smux_serialize_payload(struct smux_pkt_t *pkt, char **out,
+					unsigned int *out_len)
+{
+	*out = pkt->payload;
+	*out_len = pkt->hdr.payload_len;
+}
+
+/**
+ * Serialize padding and provide pointer to the data.
+ *
+ * @pkt             Packet
+ * @out[out]        Pointer to the serialized padding (always NULL)
+ * @out_len[out]    Pointer to the serialized payload length
+ *
+ * Since the padding field value is undefined, only the size of the patting
+ * (@out_len) is set and the buffer pointer (@out) will always be NULL.
+ */
+static void smux_serialize_padding(struct smux_pkt_t *pkt, char **out,
+					unsigned int *out_len)
+{
+	*out = NULL;
+	*out_len = pkt->hdr.pad_len;
+}
+
+/**
+ * Write data to TTY framework and handle breaking the writes up if needed.
+ *
+ * @data    Data to write
+ * @len     Length of data
+ *
+ * @returns 0 for success, < 0 for failure
+ */
+static int write_to_tty(char *data, unsigned len)
+{
+	int data_written;
+
+	if (!data)
+		return 0;
+
+	while (len > 0) {
+		data_written = smux.tty->ops->write(smux.tty, data, len);
+		if (data_written >= 0) {
+			len -= data_written;
+			data += data_written;
+		} else {
+			pr_err("%s: TTY write returned error %d\n",
+					__func__, data_written);
+			return data_written;
+		}
+
+		if (len)
+			tty_wait_until_sent(smux.tty,
+				msecs_to_jiffies(TTY_BUFFER_FULL_WAIT_MS));
+
+		/* FUTURE - add SSR logic */
+	}
+	return 0;
+}
+
+/**
+ * Write packet to TTY.
+ *
+ * @pkt packet to write
+ *
+ * @returns 0 on success
+ */
+static int smux_tx_tty(struct smux_pkt_t *pkt)
+{
+	char *data;
+	unsigned int len;
+	int ret;
+
+	if (!smux.tty) {
+		pr_err("%s: TTY not initialized", __func__);
+		return -ENOTTY;
+	}
+
+	if (pkt->hdr.cmd == SMUX_CMD_BYTE) {
+		SMUX_DBG("%s: tty send single byte\n", __func__);
+		ret = write_to_tty(&pkt->hdr.flags, 1);
+		return ret;
+	}
+
+	smux_serialize_hdr(pkt, &data, &len);
+	ret = write_to_tty(data, len);
+	if (ret) {
+		pr_err("%s: failed %d to write header %d\n",
+				__func__, ret, len);
+		return ret;
+	}
+
+	smux_serialize_payload(pkt, &data, &len);
+	ret = write_to_tty(data, len);
+	if (ret) {
+		pr_err("%s: failed %d to write payload %d\n",
+				__func__, ret, len);
+		return ret;
+	}
+
+	smux_serialize_padding(pkt, &data, &len);
+	while (len > 0) {
+		char zero = 0x0;
+		ret = write_to_tty(&zero, 1);
+		if (ret) {
+			pr_err("%s: failed %d to write padding %d\n",
+					__func__, ret, len);
+			return ret;
+		}
+		--len;
+	}
+	return 0;
+}
+
+/**
+ * Send a single character.
+ *
+ * @ch Character to send
+ */
+static void smux_send_byte(char ch)
+{
+	struct smux_pkt_t pkt;
+
+	smux_init_pkt(&pkt);
+
+	pkt.hdr.cmd = SMUX_CMD_BYTE;
+	pkt.hdr.flags = ch;
+	pkt.hdr.lcid = 0;
+	pkt.hdr.flags = ch;
+	SMUX_LOG_PKT_TX(&pkt);
+	if (!smux_byte_loopback)
+		smux_tx_tty(&pkt);
+	else
+		smux_tx_loopback(&pkt);
+}
+
+/**
+ * Receive a single-character packet (used for internal testing).
+ *
+ * @ch   Character to receive
+ * @lcid Logical channel ID for packet
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 locked.
+ */
+static int smux_receive_byte(char ch, int lcid)
+{
+	struct smux_pkt_t pkt;
+
+	smux_init_pkt(&pkt);
+	pkt.hdr.lcid = lcid;
+	pkt.hdr.cmd = SMUX_CMD_BYTE;
+	pkt.hdr.flags = ch;
+
+	return smux_dispatch_rx_pkt(&pkt);
+}
+
+/**
+ * Queue packet for transmit.
+ *
+ * @pkt_ptr  Packet to queue
+ * @ch       Channel to queue packet on
+ * @queue    Queue channel on ready list
+ */
+static void smux_tx_queue(struct smux_pkt_t *pkt_ptr, struct smux_lch_t *ch,
+		int queue)
+{
+	unsigned long flags;
+
+	SMUX_DBG("%s: queuing pkt %p\n", __func__, pkt_ptr);
+
+	spin_lock_irqsave(&ch->tx_lock_lhb2, flags);
+	list_add_tail(&pkt_ptr->list, &ch->tx_queue);
+	spin_unlock_irqrestore(&ch->tx_lock_lhb2, flags);
+
+	if (queue)
+		list_channel(ch);
+}
+
+/**
+ * Handle receive OPEN ACK command.
+ *
+ * @pkt  Received packet
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_handle_rx_open_ack(struct smux_pkt_t *pkt)
+{
+	uint8_t lcid;
+	int ret;
+	struct smux_lch_t *ch;
+	int enable_powerdown = 0;
+
+	lcid = pkt->hdr.lcid;
+	ch = &smux_lch[lcid];
+
+	spin_lock(&ch->state_lock_lhb1);
+	if (ch->local_state == SMUX_LCH_LOCAL_OPENING) {
+		SMUX_DBG("lcid %d local state 0x%x -> 0x%x\n", lcid,
+				ch->local_state,
+				SMUX_LCH_LOCAL_OPENED);
+
+		if (pkt->hdr.flags & SMUX_CMD_OPEN_POWER_COLLAPSE)
+			enable_powerdown = 1;
+
+		ch->local_state = SMUX_LCH_LOCAL_OPENED;
+		if (ch->remote_state == SMUX_LCH_REMOTE_OPENED)
+			schedule_notify(lcid, SMUX_CONNECTED, NULL);
+		ret = 0;
+	} else if (ch->remote_mode == SMUX_LCH_MODE_REMOTE_LOOPBACK) {
+		SMUX_DBG("Remote loopback OPEN ACK received\n");
+		ret = 0;
+	} else {
+		pr_err("%s: lcid %d state 0x%x open ack invalid\n",
+				__func__, lcid, ch->local_state);
+		ret = -EINVAL;
+	}
+	spin_unlock(&ch->state_lock_lhb1);
+
+	if (enable_powerdown) {
+		spin_lock(&smux.tx_lock_lha2);
+		if (!smux.powerdown_enabled) {
+			smux.powerdown_enabled = 1;
+			SMUX_DBG("%s: enabling power-collapse support\n",
+					__func__);
+		}
+		spin_unlock(&smux.tx_lock_lha2);
+	}
+
+	return ret;
+}
+
+static int smux_handle_close_ack(struct smux_pkt_t *pkt)
+{
+	uint8_t lcid;
+	int ret;
+	struct smux_lch_t *ch;
+	union notifier_metadata meta_disconnected;
+	unsigned long flags;
+
+	lcid = pkt->hdr.lcid;
+	ch = &smux_lch[lcid];
+	meta_disconnected.disconnected.is_ssr = 0;
+
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+
+	if (ch->local_state == SMUX_LCH_LOCAL_CLOSING) {
+		SMUX_DBG("lcid %d local state 0x%x -> 0x%x\n", lcid,
+				SMUX_LCH_LOCAL_CLOSING,
+				SMUX_LCH_LOCAL_CLOSED);
+		ch->local_state = SMUX_LCH_LOCAL_CLOSED;
+		if (ch->remote_state == SMUX_LCH_REMOTE_CLOSED)
+			schedule_notify(lcid, SMUX_DISCONNECTED,
+				&meta_disconnected);
+		ret = 0;
+	} else if (ch->remote_mode == SMUX_LCH_MODE_REMOTE_LOOPBACK) {
+		SMUX_DBG("Remote loopback CLOSE ACK received\n");
+		ret = 0;
+	} else {
+		pr_err("%s: lcid %d state 0x%x close ack invalid\n",
+				__func__, lcid,	ch->local_state);
+		ret = -EINVAL;
+	}
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+	return ret;
+}
+
+/**
+ * Handle receive OPEN command.
+ *
+ * @pkt  Received packet
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_handle_rx_open_cmd(struct smux_pkt_t *pkt)
+{
+	uint8_t lcid;
+	int ret;
+	struct smux_lch_t *ch;
+	struct smux_pkt_t *ack_pkt;
+	int tx_ready = 0;
+	int enable_powerdown = 0;
+
+	if (pkt->hdr.flags & SMUX_CMD_OPEN_ACK)
+		return smux_handle_rx_open_ack(pkt);
+
+	lcid = pkt->hdr.lcid;
+	ch = &smux_lch[lcid];
+
+	spin_lock(&ch->state_lock_lhb1);
+
+	if (ch->remote_state == SMUX_LCH_REMOTE_CLOSED) {
+		SMUX_DBG("lcid %d remote state 0x%x -> 0x%x\n", lcid,
+				SMUX_LCH_REMOTE_CLOSED,
+				SMUX_LCH_REMOTE_OPENED);
+
+		ch->remote_state = SMUX_LCH_REMOTE_OPENED;
+		if (pkt->hdr.flags & SMUX_CMD_OPEN_POWER_COLLAPSE)
+			enable_powerdown = 1;
+
+		/* Send Open ACK */
+		ack_pkt = smux_alloc_pkt();
+		if (!ack_pkt) {
+			/* exit out to allow retrying this later */
+			ret = -ENOMEM;
+			goto out;
+		}
+		ack_pkt->hdr.cmd = SMUX_CMD_OPEN_LCH;
+		ack_pkt->hdr.flags = SMUX_CMD_OPEN_ACK
+			| SMUX_CMD_OPEN_POWER_COLLAPSE;
+		ack_pkt->hdr.lcid = lcid;
+		ack_pkt->hdr.payload_len = 0;
+		ack_pkt->hdr.pad_len = 0;
+		if (pkt->hdr.flags & SMUX_CMD_OPEN_REMOTE_LOOPBACK) {
+			ch->remote_mode = SMUX_LCH_MODE_REMOTE_LOOPBACK;
+			ack_pkt->hdr.flags |= SMUX_CMD_OPEN_REMOTE_LOOPBACK;
+		}
+		smux_tx_queue(ack_pkt, ch, 0);
+		tx_ready = 1;
+
+		if (ch->remote_mode == SMUX_LCH_MODE_REMOTE_LOOPBACK) {
+			/*
+			 * Send an Open command to the remote side to
+			 * simulate our local client doing it.
+			 */
+			ack_pkt = smux_alloc_pkt();
+			if (ack_pkt) {
+				ack_pkt->hdr.lcid = lcid;
+				ack_pkt->hdr.cmd = SMUX_CMD_OPEN_LCH;
+				ack_pkt->hdr.flags =
+					SMUX_CMD_OPEN_POWER_COLLAPSE;
+				ack_pkt->hdr.payload_len = 0;
+				ack_pkt->hdr.pad_len = 0;
+				smux_tx_queue(ack_pkt, ch, 0);
+				tx_ready = 1;
+			} else {
+				pr_err("%s: Remote loopack allocation failure\n",
+						__func__);
+			}
+		} else if (ch->local_state == SMUX_LCH_LOCAL_OPENED) {
+			schedule_notify(lcid, SMUX_CONNECTED, NULL);
+		}
+		ret = 0;
+	} else {
+		pr_err("%s: lcid %d remote state 0x%x open invalid\n",
+			   __func__, lcid, ch->remote_state);
+		ret = -EINVAL;
+	}
+
+out:
+	spin_unlock(&ch->state_lock_lhb1);
+
+	if (enable_powerdown) {
+		spin_lock(&smux.tx_lock_lha2);
+		smux.powerdown_enabled = 1;
+		SMUX_DBG("%s: enabling power-collapse support\n", __func__);
+		spin_unlock(&smux.tx_lock_lha2);
+	}
+
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/**
+ * Handle receive CLOSE command.
+ *
+ * @pkt  Received packet
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_handle_rx_close_cmd(struct smux_pkt_t *pkt)
+{
+	uint8_t lcid;
+	int ret;
+	struct smux_lch_t *ch;
+	struct smux_pkt_t *ack_pkt;
+	union notifier_metadata meta_disconnected;
+	int tx_ready = 0;
+
+	if (pkt->hdr.flags & SMUX_CMD_CLOSE_ACK)
+		return smux_handle_close_ack(pkt);
+
+	lcid = pkt->hdr.lcid;
+	ch = &smux_lch[lcid];
+	meta_disconnected.disconnected.is_ssr = 0;
+
+	spin_lock(&ch->state_lock_lhb1);
+	if (ch->remote_state == SMUX_LCH_REMOTE_OPENED) {
+		SMUX_DBG("lcid %d remote state 0x%x -> 0x%x\n", lcid,
+				SMUX_LCH_REMOTE_OPENED,
+				SMUX_LCH_REMOTE_CLOSED);
+
+		ack_pkt = smux_alloc_pkt();
+		if (!ack_pkt) {
+			/* exit out to allow retrying this later */
+			ret = -ENOMEM;
+			goto out;
+		}
+		ch->remote_state = SMUX_LCH_REMOTE_CLOSED;
+		ack_pkt->hdr.cmd = SMUX_CMD_CLOSE_LCH;
+		ack_pkt->hdr.flags = SMUX_CMD_CLOSE_ACK;
+		ack_pkt->hdr.lcid = lcid;
+		ack_pkt->hdr.payload_len = 0;
+		ack_pkt->hdr.pad_len = 0;
+		smux_tx_queue(ack_pkt, ch, 0);
+		tx_ready = 1;
+
+		if (ch->remote_mode == SMUX_LCH_MODE_REMOTE_LOOPBACK) {
+			/*
+			 * Send a Close command to the remote side to simulate
+			 * our local client doing it.
+			 */
+			ack_pkt = smux_alloc_pkt();
+			if (ack_pkt) {
+				ack_pkt->hdr.lcid = lcid;
+				ack_pkt->hdr.cmd = SMUX_CMD_CLOSE_LCH;
+				ack_pkt->hdr.flags = 0;
+				ack_pkt->hdr.payload_len = 0;
+				ack_pkt->hdr.pad_len = 0;
+				smux_tx_queue(ack_pkt, ch, 0);
+				tx_ready = 1;
+			} else {
+				pr_err("%s: Remote loopack allocation failure\n",
+						__func__);
+			}
+		}
+
+		if (ch->local_state == SMUX_LCH_LOCAL_CLOSED)
+			schedule_notify(lcid, SMUX_DISCONNECTED,
+				&meta_disconnected);
+		ret = 0;
+	} else {
+		pr_err("%s: lcid %d remote state 0x%x close invalid\n",
+				__func__, lcid, ch->remote_state);
+		ret = -EINVAL;
+	}
+out:
+	spin_unlock(&ch->state_lock_lhb1);
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/*
+ * Handle receive DATA command.
+ *
+ * @pkt  Received packet
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_handle_rx_data_cmd(struct smux_pkt_t *pkt)
+{
+	uint8_t lcid;
+	int ret;
+	int i;
+	int tmp;
+	int rx_len;
+	struct smux_lch_t *ch;
+	union notifier_metadata metadata;
+	int remote_loopback;
+	int tx_ready = 0;
+	struct smux_pkt_t *ack_pkt;
+	unsigned long flags;
+
+	if (!pkt || smux_assert_lch_id(pkt->hdr.lcid))
+		return -ENXIO;
+
+	lcid = pkt->hdr.lcid;
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+	remote_loopback = ch->remote_mode == SMUX_LCH_MODE_REMOTE_LOOPBACK;
+
+	if (ch->local_state != SMUX_LCH_LOCAL_OPENED
+		&& !remote_loopback) {
+		pr_err("smux: ch %d error data on local state 0x%x",
+					lcid, ch->local_state);
+		ret = -EIO;
+		goto out;
+	}
+
+	if (ch->remote_state != SMUX_LCH_REMOTE_OPENED) {
+		pr_err("smux: ch %d error data on remote state 0x%x",
+					lcid, ch->remote_state);
+		ret = -EIO;
+		goto out;
+	}
+
+	rx_len = pkt->hdr.payload_len;
+	if (rx_len == 0) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	for (i = 0; i < SMUX_GET_RX_BUFF_MAX_RETRY_CNT; ++i) {
+		metadata.read.pkt_priv = 0;
+		metadata.read.buffer = 0;
+
+		if (!remote_loopback) {
+			tmp = ch->get_rx_buffer(ch->priv,
+					(void **)&metadata.read.pkt_priv,
+					(void **)&metadata.read.buffer,
+					rx_len);
+			if (tmp == 0 && metadata.read.buffer) {
+				/* place data into RX buffer */
+				memcpy(metadata.read.buffer, pkt->payload,
+								rx_len);
+				metadata.read.len = rx_len;
+				schedule_notify(lcid, SMUX_READ_DONE,
+								&metadata);
+				ret = 0;
+				break;
+			} else if (tmp == -EAGAIN) {
+				ret = -ENOMEM;
+			} else if (tmp < 0) {
+				schedule_notify(lcid, SMUX_READ_FAIL, NULL);
+				ret = -ENOMEM;
+				break;
+			} else if (!metadata.read.buffer) {
+				pr_err("%s: get_rx_buffer() buffer is NULL\n",
+					__func__);
+				ret = -ENOMEM;
+			}
+		} else {
+			/* Echo the data back to the remote client. */
+			ack_pkt = smux_alloc_pkt();
+			if (ack_pkt) {
+				ack_pkt->hdr.lcid = lcid;
+				ack_pkt->hdr.cmd = SMUX_CMD_DATA;
+				ack_pkt->hdr.flags = 0;
+				ack_pkt->hdr.payload_len = pkt->hdr.payload_len;
+				ack_pkt->payload = pkt->payload;
+				ack_pkt->hdr.pad_len = pkt->hdr.pad_len;
+				smux_tx_queue(ack_pkt, ch, 0);
+				tx_ready = 1;
+			} else {
+				pr_err("%s: Remote loopack allocation failure\n",
+						__func__);
+			}
+		}
+	}
+
+out:
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/**
+ * Handle receive byte command for testing purposes.
+ *
+ * @pkt  Received packet
+ *
+ * @returns 0 for success
+ */
+static int smux_handle_rx_byte_cmd(struct smux_pkt_t *pkt)
+{
+	uint8_t lcid;
+	int ret;
+	struct smux_lch_t *ch;
+	union notifier_metadata metadata;
+	unsigned long flags;
+
+	if (!pkt || smux_assert_lch_id(pkt->hdr.lcid))
+		return -ENXIO;
+
+	lcid = pkt->hdr.lcid;
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+
+	if (ch->local_state != SMUX_LCH_LOCAL_OPENED) {
+		pr_err("smux: ch %d error data on local state 0x%x",
+					lcid, ch->local_state);
+		ret = -EIO;
+		goto out;
+	}
+
+	if (ch->remote_state != SMUX_LCH_REMOTE_OPENED) {
+		pr_err("smux: ch %d error data on remote state 0x%x",
+					lcid, ch->remote_state);
+		ret = -EIO;
+		goto out;
+	}
+
+	metadata.read.pkt_priv = (void *)(int)pkt->hdr.flags;
+	metadata.read.buffer = 0;
+	schedule_notify(lcid, SMUX_READ_DONE, &metadata);
+	ret = 0;
+
+out:
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+	return ret;
+}
+
+/**
+ * Handle receive status command.
+ *
+ * @pkt  Received packet
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_handle_rx_status_cmd(struct smux_pkt_t *pkt)
+{
+	uint8_t lcid;
+	int ret;
+	struct smux_lch_t *ch;
+	union notifier_metadata meta;
+	unsigned long flags;
+	int tx_ready = 0;
+
+	lcid = pkt->hdr.lcid;
+	ch = &smux_lch[lcid];
+
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+	meta.tiocm.tiocm_old = ch->remote_tiocm;
+	meta.tiocm.tiocm_new = pkt->hdr.flags;
+
+	/* update logical channel flow control */
+	if ((meta.tiocm.tiocm_old & SMUX_CMD_STATUS_FLOW_CNTL) ^
+		(meta.tiocm.tiocm_new & SMUX_CMD_STATUS_FLOW_CNTL)) {
+		/* logical channel flow control changed */
+		if (pkt->hdr.flags & SMUX_CMD_STATUS_FLOW_CNTL) {
+			/* disabled TX */
+			SMUX_DBG("TX Flow control enabled\n");
+			ch->tx_flow_control = 1;
+		} else {
+			/* re-enable channel */
+			SMUX_DBG("TX Flow control disabled\n");
+			ch->tx_flow_control = 0;
+			tx_ready = 1;
+		}
+	}
+	meta.tiocm.tiocm_old = msm_smux_tiocm_get_atomic(ch);
+	ch->remote_tiocm = pkt->hdr.flags;
+	meta.tiocm.tiocm_new = msm_smux_tiocm_get_atomic(ch);
+
+	/* client notification for status change */
+	if (IS_FULLY_OPENED(ch)) {
+		if (meta.tiocm.tiocm_old != meta.tiocm.tiocm_new)
+			schedule_notify(lcid, SMUX_TIOCM_UPDATE, &meta);
+		ret = 0;
+	}
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/**
+ * Handle receive power command.
+ *
+ * @pkt  Received packet
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_handle_rx_power_cmd(struct smux_pkt_t *pkt)
+{
+	int tx_ready = 0;
+	struct smux_pkt_t *ack_pkt;
+
+	spin_lock(&smux.tx_lock_lha2);
+	if (pkt->hdr.flags & SMUX_CMD_PWR_CTL_ACK) {
+		/* local sleep request ack */
+		if (smux.power_state == SMUX_PWR_TURNING_OFF) {
+			/* Power-down complete, turn off UART */
+			SMUX_DBG("%s: Power %d->%d\n", __func__,
+					smux.power_state, SMUX_PWR_OFF_FLUSH);
+			smux.power_state = SMUX_PWR_OFF_FLUSH;
+			queue_work(smux_tx_wq, &smux_inactivity_work);
+		} else {
+			pr_err("%s: sleep request ack invalid in state %d\n",
+					__func__, smux.power_state);
+		}
+	} else {
+		/* remote sleep request */
+		if (smux.power_state == SMUX_PWR_ON
+			|| smux.power_state == SMUX_PWR_TURNING_OFF) {
+			ack_pkt = smux_alloc_pkt();
+			if (ack_pkt) {
+				SMUX_DBG("%s: Power %d->%d\n", __func__,
+						smux.power_state,
+						SMUX_PWR_TURNING_OFF_FLUSH);
+
+				/* send power-down request */
+				ack_pkt->hdr.cmd = SMUX_CMD_PWR_CTL;
+				ack_pkt->hdr.flags = SMUX_CMD_PWR_CTL_ACK;
+				ack_pkt->hdr.lcid = pkt->hdr.lcid;
+				smux_tx_queue(ack_pkt,
+					      &smux_lch[ack_pkt->hdr.lcid], 0);
+				tx_ready = 1;
+				smux.power_state = SMUX_PWR_TURNING_OFF_FLUSH;
+				queue_delayed_work(smux_tx_wq,
+					&smux_delayed_inactivity_work,
+					msecs_to_jiffies(
+						SMUX_INACTIVITY_TIMEOUT_MS));
+			}
+		} else {
+			pr_err("%s: sleep request invalid in state %d\n",
+					__func__, smux.power_state);
+		}
+	}
+	spin_unlock(&smux.tx_lock_lha2);
+
+	if (tx_ready)
+		list_channel(&smux_lch[ack_pkt->hdr.lcid]);
+
+	return 0;
+}
+
+/**
+ * Handle dispatching a completed packet for receive processing.
+ *
+ * @pkt Packet to process
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_dispatch_rx_pkt(struct smux_pkt_t *pkt)
+{
+	int ret;
+
+	SMUX_LOG_PKT_RX(pkt);
+
+	switch (pkt->hdr.cmd) {
+	case SMUX_CMD_OPEN_LCH:
+		ret = smux_handle_rx_open_cmd(pkt);
+		break;
+
+	case SMUX_CMD_DATA:
+		ret = smux_handle_rx_data_cmd(pkt);
+		break;
+
+	case SMUX_CMD_CLOSE_LCH:
+		ret = smux_handle_rx_close_cmd(pkt);
+		break;
+
+	case SMUX_CMD_STATUS:
+		ret = smux_handle_rx_status_cmd(pkt);
+		break;
+
+	case SMUX_CMD_PWR_CTL:
+		ret = smux_handle_rx_power_cmd(pkt);
+		break;
+
+	case SMUX_CMD_BYTE:
+		ret = smux_handle_rx_byte_cmd(pkt);
+		break;
+
+	default:
+		pr_err("%s: command %d unknown\n", __func__, pkt->hdr.cmd);
+		ret = -EINVAL;
+	}
+	return ret;
+}
+
+/**
+ * Deserializes a packet and dispatches it to the packet receive logic.
+ *
+ * @data    Raw data for one packet
+ * @len     Length of the data
+ *
+ * @returns 0 for success
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static int smux_deserialize(unsigned char *data, int len)
+{
+	struct smux_pkt_t recv;
+	uint8_t lcid;
+
+	smux_init_pkt(&recv);
+
+	/*
+	 * It may be possible to optimize this to not use the
+	 * temporary buffer.
+	 */
+	memcpy(&recv.hdr, data, sizeof(struct smux_hdr_t));
+
+	if (recv.hdr.magic != SMUX_MAGIC) {
+		pr_err("%s: invalid header magic\n", __func__);
+		return -EINVAL;
+	}
+
+	lcid = recv.hdr.lcid;
+	if (smux_assert_lch_id(lcid)) {
+		pr_err("%s: invalid channel id %d\n", __func__, lcid);
+		return -ENXIO;
+	}
+
+	if (recv.hdr.payload_len)
+		recv.payload = data + sizeof(struct smux_hdr_t);
+
+	return smux_dispatch_rx_pkt(&recv);
+}
+
+/**
+ * Handle wakeup request byte.
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static void smux_handle_wakeup_req(void)
+{
+	spin_lock(&smux.tx_lock_lha2);
+	if (smux.power_state == SMUX_PWR_OFF
+		|| smux.power_state == SMUX_PWR_TURNING_ON) {
+		/* wakeup system */
+		SMUX_DBG("%s: Power %d->%d\n", __func__,
+				smux.power_state, SMUX_PWR_ON);
+		smux.power_state = SMUX_PWR_ON;
+		queue_work(smux_tx_wq, &smux_wakeup_work);
+		queue_work(smux_tx_wq, &smux_tx_work);
+		queue_delayed_work(smux_tx_wq, &smux_delayed_inactivity_work,
+			msecs_to_jiffies(SMUX_INACTIVITY_TIMEOUT_MS));
+		smux_send_byte(SMUX_WAKEUP_ACK);
+	} else {
+		smux_send_byte(SMUX_WAKEUP_ACK);
+	}
+	spin_unlock(&smux.tx_lock_lha2);
+}
+
+/**
+ * Handle wakeup request ack.
+ *
+ * Called with rx_lock_lha1 already locked.
+ */
+static void smux_handle_wakeup_ack(void)
+{
+	spin_lock(&smux.tx_lock_lha2);
+	if (smux.power_state == SMUX_PWR_TURNING_ON) {
+		/* received response to wakeup request */
+		SMUX_DBG("%s: Power %d->%d\n", __func__,
+				smux.power_state, SMUX_PWR_ON);
+		smux.power_state = SMUX_PWR_ON;
+		queue_work(smux_tx_wq, &smux_tx_work);
+		queue_delayed_work(smux_tx_wq, &smux_delayed_inactivity_work,
+			msecs_to_jiffies(SMUX_INACTIVITY_TIMEOUT_MS));
+
+	} else if (smux.power_state != SMUX_PWR_ON) {
+		/* invalid message */
+		pr_err("%s: wakeup request ack invalid in state %d\n",
+				__func__, smux.power_state);
+	}
+	spin_unlock(&smux.tx_lock_lha2);
+}
+
+/**
+ * RX State machine - IDLE state processing.
+ *
+ * @data  New RX data to process
+ * @len   Length of the data
+ * @used  Return value of length processed
+ * @flag  Error flag - TTY_NORMAL 0 for no failure
+ *
+ * Called with rx_lock_lha1 locked.
+ */
+static void smux_rx_handle_idle(const unsigned char *data,
+		int len, int *used, int flag)
+{
+	int i;
+
+	if (flag) {
+		if (smux_byte_loopback)
+			smux_receive_byte(SMUX_UT_ECHO_ACK_FAIL,
+					smux_byte_loopback);
+		pr_err("%s: TTY error 0x%x - ignoring\n", __func__, flag);
+		++*used;
+		return;
+	}
+
+	for (i = *used; i < len && smux.rx_state == SMUX_RX_IDLE; i++) {
+		switch (data[i]) {
+		case SMUX_MAGIC_WORD1:
+			smux.rx_state = SMUX_RX_MAGIC;
+			break;
+		case SMUX_WAKEUP_REQ:
+			smux_handle_wakeup_req();
+			break;
+		case SMUX_WAKEUP_ACK:
+			smux_handle_wakeup_ack();
+			break;
+		default:
+			/* unexpected character */
+			if (smux_byte_loopback && data[i] == SMUX_UT_ECHO_REQ)
+				smux_receive_byte(SMUX_UT_ECHO_ACK_OK,
+						smux_byte_loopback);
+			pr_err("%s: parse error 0x%02x - ignoring\n", __func__,
+					(unsigned)data[i]);
+			break;
+		}
+	}
+
+	*used = i;
+}
+
+/**
+ * RX State machine - Header Magic state processing.
+ *
+ * @data  New RX data to process
+ * @len   Length of the data
+ * @used  Return value of length processed
+ * @flag  Error flag - TTY_NORMAL 0 for no failure
+ *
+ * Called with rx_lock_lha1 locked.
+ */
+static void smux_rx_handle_magic(const unsigned char *data,
+		int len, int *used, int flag)
+{
+	int i;
+
+	if (flag) {
+		pr_err("%s: TTY RX error %d\n", __func__, flag);
+		smux_enter_reset();
+		smux.rx_state = SMUX_RX_FAILURE;
+		++*used;
+		return;
+	}
+
+	for (i = *used; i < len && smux.rx_state == SMUX_RX_MAGIC; i++) {
+		/* wait for completion of the magic */
+		if (data[i] == SMUX_MAGIC_WORD2) {
+			smux.recv_len = 0;
+			smux.recv_buf[smux.recv_len++] = SMUX_MAGIC_WORD1;
+			smux.recv_buf[smux.recv_len++] = SMUX_MAGIC_WORD2;
+			smux.rx_state = SMUX_RX_HDR;
+		} else {
+			/* unexpected / trash character */
+			pr_err("%s: rx parse error for char %c; *used=%d, len=%d\n",
+					__func__, data[i], *used, len);
+			smux.rx_state = SMUX_RX_IDLE;
+		}
+	}
+
+	*used = i;
+}
+
+/**
+ * RX State machine - Packet Header state processing.
+ *
+ * @data  New RX data to process
+ * @len   Length of the data
+ * @used  Return value of length processed
+ * @flag  Error flag - TTY_NORMAL 0 for no failure
+ *
+ * Called with rx_lock_lha1 locked.
+ */
+static void smux_rx_handle_hdr(const unsigned char *data,
+		int len, int *used, int flag)
+{
+	int i;
+	struct smux_hdr_t *hdr;
+
+	if (flag) {
+		pr_err("%s: TTY RX error %d\n", __func__, flag);
+		smux_enter_reset();
+		smux.rx_state = SMUX_RX_FAILURE;
+		++*used;
+		return;
+	}
+
+	for (i = *used; i < len && smux.rx_state == SMUX_RX_HDR; i++) {
+		smux.recv_buf[smux.recv_len++] = data[i];
+
+		if (smux.recv_len == sizeof(struct smux_hdr_t)) {
+			/* complete header received */
+			hdr = (struct smux_hdr_t *)smux.recv_buf;
+			smux.pkt_remain = hdr->payload_len + hdr->pad_len;
+			smux.rx_state = SMUX_RX_PAYLOAD;
+		}
+	}
+	*used = i;
+}
+
+/**
+ * RX State machine - Packet Payload state processing.
+ *
+ * @data  New RX data to process
+ * @len   Length of the data
+ * @used  Return value of length processed
+ * @flag  Error flag - TTY_NORMAL 0 for no failure
+ *
+ * Called with rx_lock_lha1 locked.
+ */
+static void smux_rx_handle_pkt_payload(const unsigned char *data,
+		int len, int *used, int flag)
+{
+	int remaining;
+
+	if (flag) {
+		pr_err("%s: TTY RX error %d\n", __func__, flag);
+		smux_enter_reset();
+		smux.rx_state = SMUX_RX_FAILURE;
+		++*used;
+		return;
+	}
+
+	/* copy data into rx buffer */
+	if (smux.pkt_remain < (len - *used))
+		remaining = smux.pkt_remain;
+	else
+		remaining = len - *used;
+
+	memcpy(&smux.recv_buf[smux.recv_len], &data[*used], remaining);
+	smux.recv_len += remaining;
+	smux.pkt_remain -= remaining;
+	*used += remaining;
+
+	if (smux.pkt_remain == 0) {
+		/* complete packet received */
+		smux_deserialize(smux.recv_buf, smux.recv_len);
+		smux.rx_state = SMUX_RX_IDLE;
+	}
+}
+
+/**
+ * Feed data to the receive state machine.
+ *
+ * @data Pointer to data block
+ * @len  Length of data
+ * @flag TTY_NORMAL (0) for no error, otherwise TTY Error Flag
+ *
+ * Called with rx_lock_lha1 locked.
+ */
+void smux_rx_state_machine(const unsigned char *data,
+						int len, int flag)
+{
+	unsigned long flags;
+	int used;
+	int initial_rx_state;
+
+
+	SMUX_DBG("%s: %p, len=%d, flag=%d\n", __func__, data, len, flag);
+	spin_lock_irqsave(&smux.rx_lock_lha1, flags);
+	used = 0;
+	smux.rx_activity_flag = 1;
+	do {
+		SMUX_DBG("%s: state %d; %d of %d\n",
+				__func__, smux.rx_state, used, len);
+		initial_rx_state = smux.rx_state;
+
+		switch (smux.rx_state) {
+		case SMUX_RX_IDLE:
+			smux_rx_handle_idle(data, len, &used, flag);
+			break;
+		case SMUX_RX_MAGIC:
+			smux_rx_handle_magic(data, len, &used, flag);
+			break;
+		case SMUX_RX_HDR:
+			smux_rx_handle_hdr(data, len, &used, flag);
+			break;
+		case SMUX_RX_PAYLOAD:
+			smux_rx_handle_pkt_payload(data, len, &used, flag);
+			break;
+		default:
+			SMUX_DBG("%s: invalid state %d\n",
+					__func__, smux.rx_state);
+			smux.rx_state = SMUX_RX_IDLE;
+			break;
+		}
+	} while (used < len || smux.rx_state != initial_rx_state);
+	spin_unlock_irqrestore(&smux.rx_lock_lha1, flags);
+}
+
+/**
+ * Add channel to transmit-ready list and trigger transmit worker.
+ *
+ * @ch Channel to add
+ */
+static void list_channel(struct smux_lch_t *ch)
+{
+	unsigned long flags;
+
+	SMUX_DBG("%s: listing channel %d\n",
+			__func__, ch->lcid);
+
+	spin_lock_irqsave(&smux.tx_lock_lha2, flags);
+	spin_lock(&ch->tx_lock_lhb2);
+	smux.tx_activity_flag = 1;
+	if (list_empty(&ch->tx_ready_list))
+		list_add_tail(&ch->tx_ready_list, &smux.lch_tx_ready_list);
+	spin_unlock(&ch->tx_lock_lhb2);
+	spin_unlock_irqrestore(&smux.tx_lock_lha2, flags);
+
+	queue_work(smux_tx_wq, &smux_tx_work);
+}
+
+/**
+ * Transmit packet on correct transport and then perform client
+ * notification.
+ *
+ * @ch   Channel to transmit on
+ * @pkt  Packet to transmit
+ */
+static void smux_tx_pkt(struct smux_lch_t *ch, struct smux_pkt_t *pkt)
+{
+	union notifier_metadata meta_write;
+	int ret;
+
+	if (ch && pkt) {
+		SMUX_LOG_PKT_TX(pkt);
+		if (ch->local_mode == SMUX_LCH_MODE_LOCAL_LOOPBACK)
+			ret = smux_tx_loopback(pkt);
+		else
+			ret = smux_tx_tty(pkt);
+
+		if (pkt->hdr.cmd == SMUX_CMD_DATA) {
+			/* notify write-done */
+			meta_write.write.pkt_priv = pkt->priv;
+			meta_write.write.buffer = pkt->payload;
+			meta_write.write.len = pkt->hdr.payload_len;
+			if (ret >= 0) {
+				SMUX_DBG("%s: PKT write done", __func__);
+				schedule_notify(ch->lcid, SMUX_WRITE_DONE,
+						&meta_write);
+			} else {
+				pr_err("%s: failed to write pkt %d\n",
+						__func__, ret);
+				schedule_notify(ch->lcid, SMUX_WRITE_FAIL,
+						&meta_write);
+			}
+		}
+	}
+}
+
+/**
+ * Power-up the UART.
+ */
+static void smux_uart_power_on(void)
+{
+	struct uart_state *state;
+
+	if (!smux.tty || !smux.tty->driver_data) {
+		pr_err("%s: unable to find UART port for tty %p\n",
+				__func__, smux.tty);
+		return;
+	}
+	state = smux.tty->driver_data;
+	msm_hs_request_clock_on(state->uart_port);
+}
+
+/**
+ * Power down the UART.
+ */
+static void smux_uart_power_off(void)
+{
+	struct uart_state *state;
+
+	if (!smux.tty || !smux.tty->driver_data) {
+		pr_err("%s: unable to find UART port for tty %p\n",
+				__func__, smux.tty);
+		return;
+	}
+	state = smux.tty->driver_data;
+	msm_hs_request_clock_off(state->uart_port);
+}
+
+/**
+ * TX Wakeup Worker
+ *
+ * @work Not used
+ *
+ * Do an exponential back-off wakeup sequence with a maximum period
+ * of approximately 1 second (1 << 20 microseconds).
+ */
+static void smux_wakeup_worker(struct work_struct *work)
+{
+	unsigned long flags;
+	unsigned wakeup_delay;
+	int complete = 0;
+
+	for (;;) {
+		spin_lock_irqsave(&smux.tx_lock_lha2, flags);
+		if (smux.power_state == SMUX_PWR_ON) {
+			/* wakeup complete */
+			complete = 1;
+			spin_unlock_irqrestore(&smux.tx_lock_lha2, flags);
+			break;
+		} else {
+			/* retry */
+			wakeup_delay = smux.pwr_wakeup_delay_us;
+			smux.pwr_wakeup_delay_us <<= 1;
+			if (smux.pwr_wakeup_delay_us > SMUX_WAKEUP_DELAY_MAX)
+				smux.pwr_wakeup_delay_us =
+					SMUX_WAKEUP_DELAY_MAX;
+		}
+		spin_unlock_irqrestore(&smux.tx_lock_lha2, flags);
+		SMUX_DBG("%s: triggering wakeup\n", __func__);
+		smux_send_byte(SMUX_WAKEUP_REQ);
+
+		if (wakeup_delay < SMUX_WAKEUP_DELAY_MIN) {
+			SMUX_DBG("%s: sleeping for %u us\n", __func__,
+					wakeup_delay);
+			usleep_range(wakeup_delay, 2*wakeup_delay);
+		} else {
+			/* schedule delayed work */
+			SMUX_DBG("%s: scheduling delayed wakeup in %u ms\n",
+					__func__, wakeup_delay / 1000);
+			queue_delayed_work(smux_tx_wq,
+					&smux_wakeup_delayed_work,
+					msecs_to_jiffies(wakeup_delay / 1000));
+			break;
+		}
+	}
+
+	if (complete) {
+		SMUX_DBG("%s: wakeup complete\n", __func__);
+		/*
+		 * Cancel any pending retry.  This avoids a race condition with
+		 * a new power-up request because:
+		 * 1) this worker doesn't modify the state
+		 * 2) this worker is processed on the same single-threaded
+		 *    workqueue as new TX wakeup requests
+		 */
+		cancel_delayed_work(&smux_wakeup_delayed_work);
+	}
+}
+
+
+/**
+ * Inactivity timeout worker.  Periodically scheduled when link is active.
+ * When it detects inactivity, it will power-down the UART link.
+ *
+ * @work  Work structure (not used)
+ */
+static void smux_inactivity_worker(struct work_struct *work)
+{
+	int tx_ready = 0;
+	struct smux_pkt_t *pkt;
+	unsigned long flags;
+
+	spin_lock_irqsave(&smux.rx_lock_lha1, flags);
+	spin_lock(&smux.tx_lock_lha2);
+
+	if (!smux.tx_activity_flag && !smux.rx_activity_flag) {
+		/* no activity */
+		if (smux.powerdown_enabled) {
+			if (smux.power_state == SMUX_PWR_ON) {
+				/* start power-down sequence */
+				pkt = smux_alloc_pkt();
+				if (pkt) {
+					SMUX_DBG("%s: Power %d->%d\n", __func__,
+						smux.power_state,
+						SMUX_PWR_TURNING_OFF);
+					smux.power_state = SMUX_PWR_TURNING_OFF;
+
+					/* send power-down request */
+					pkt->hdr.cmd = SMUX_CMD_PWR_CTL;
+					pkt->hdr.flags = 0;
+					pkt->hdr.lcid = 0;
+					smux_tx_queue(pkt,
+						&smux_lch[SMUX_TEST_LCID],
+						0);
+					tx_ready = 1;
+				}
+			}
+		} else {
+			SMUX_DBG("%s: link inactive, but powerdown disabled\n",
+					__func__);
+		}
+	}
+	smux.tx_activity_flag = 0;
+	smux.rx_activity_flag = 0;
+
+	spin_unlock(&smux.tx_lock_lha2);
+	spin_unlock_irqrestore(&smux.rx_lock_lha1, flags);
+
+	if (tx_ready)
+		list_channel(&smux_lch[SMUX_TEST_LCID]);
+
+	if ((smux.power_state == SMUX_PWR_OFF_FLUSH) ||
+	    (smux.power_state == SMUX_PWR_TURNING_OFF_FLUSH)) {
+		/* ready to power-down the UART */
+		SMUX_DBG("%s: Power %d->%d\n", __func__,
+				smux.power_state, SMUX_PWR_OFF);
+		smux_uart_power_off();
+		spin_lock_irqsave(&smux.tx_lock_lha2, flags);
+		smux.power_state = SMUX_PWR_OFF;
+		spin_unlock_irqrestore(&smux.tx_lock_lha2, flags);
+	}
+
+	/* reschedule inactivity worker */
+	if (smux.power_state != SMUX_PWR_OFF)
+		queue_delayed_work(smux_tx_wq, &smux_delayed_inactivity_work,
+			msecs_to_jiffies(SMUX_INACTIVITY_TIMEOUT_MS));
+}
+
+/**
+ * Transmit worker handles serializing and transmitting packets onto the
+ * underlying transport.
+ *
+ * @work  Work structure (not used)
+ */
+static void smux_tx_worker(struct work_struct *work)
+{
+	struct smux_pkt_t *pkt;
+	struct smux_lch_t *ch;
+	unsigned low_wm_notif;
+	unsigned lcid;
+	unsigned long flags;
+
+
+	/*
+	 * Transmit packets in round-robin fashion based upon ready
+	 * channels.
+	 *
+	 * To eliminate the need to hold a lock for the entire
+	 * iteration through the channel ready list, the head of the
+	 * ready-channel list is always the next channel to be
+	 * processed.  To send a packet, the first valid packet in
+	 * the head channel is removed and the head channel is then
+	 * rescheduled at the end of the queue by removing it and
+	 * inserting after the tail.  The locks can then be released
+	 * while the packet is processed.
+	 */
+	for (;;) {
+		pkt = NULL;
+		low_wm_notif = 0;
+
+		/* get the next ready channel */
+		spin_lock_irqsave(&smux.tx_lock_lha2, flags);
+		if (list_empty(&smux.lch_tx_ready_list)) {
+			/* no ready channels */
+			SMUX_DBG("%s: no more ready channels, exiting\n",
+					__func__);
+			spin_unlock_irqrestore(&smux.tx_lock_lha2, flags);
+			break;
+		}
+		smux.tx_activity_flag = 1;
+
+		if (smux.power_state != SMUX_PWR_ON
+			&& smux.power_state != SMUX_PWR_TURNING_OFF
+			&& smux.power_state != SMUX_PWR_TURNING_OFF_FLUSH) {
+			/* Link isn't ready to transmit */
+			if (smux.power_state == SMUX_PWR_OFF) {
+				/* link is off, trigger wakeup */
+				smux.pwr_wakeup_delay_us = 1;
+				SMUX_DBG("%s: Power %d->%d\n", __func__,
+						smux.power_state,
+						SMUX_PWR_TURNING_ON);
+				smux.power_state = SMUX_PWR_TURNING_ON;
+				spin_unlock_irqrestore(&smux.tx_lock_lha2,
+						flags);
+				smux_uart_power_on();
+				queue_work(smux_tx_wq, &smux_wakeup_work);
+			} else {
+				SMUX_DBG("%s: can not tx with power state %d\n",
+						__func__,
+						smux.power_state);
+				spin_unlock_irqrestore(&smux.tx_lock_lha2,
+						flags);
+			}
+			break;
+		}
+
+		/* get the next packet to send and rotate channel list */
+		ch = list_first_entry(&smux.lch_tx_ready_list,
+						struct smux_lch_t,
+						tx_ready_list);
+
+		spin_lock(&ch->state_lock_lhb1);
+		spin_lock(&ch->tx_lock_lhb2);
+		if (!list_empty(&ch->tx_queue)) {
+			/*
+			 * If remote TX flow control is enabled or
+			 * the channel is not fully opened, then only
+			 * send command packets.
+			 */
+			if (ch->tx_flow_control || !IS_FULLY_OPENED(ch)) {
+				struct smux_pkt_t *curr;
+				list_for_each_entry(curr, &ch->tx_queue, list) {
+					if (curr->hdr.cmd != SMUX_CMD_DATA) {
+						pkt = curr;
+						break;
+					}
+				}
+			} else {
+				/* get next cmd/data packet to send */
+				pkt = list_first_entry(&ch->tx_queue,
+						struct smux_pkt_t, list);
+			}
+		}
+
+		if (pkt) {
+			list_del(&pkt->list);
+
+			/* update packet stats */
+			if (pkt->hdr.cmd == SMUX_CMD_DATA) {
+				--ch->tx_pending_data_cnt;
+				if (ch->notify_lwm &&
+					ch->tx_pending_data_cnt
+						<= SMUX_WM_LOW) {
+					ch->notify_lwm = 0;
+					low_wm_notif = 1;
+				}
+			}
+
+			/* advance to the next ready channel */
+			list_rotate_left(&smux.lch_tx_ready_list);
+		} else {
+			/* no data in channel to send, remove from ready list */
+			list_del(&ch->tx_ready_list);
+			INIT_LIST_HEAD(&ch->tx_ready_list);
+		}
+		lcid = ch->lcid;
+		spin_unlock(&ch->tx_lock_lhb2);
+		spin_unlock(&ch->state_lock_lhb1);
+		spin_unlock_irqrestore(&smux.tx_lock_lha2, flags);
+
+		if (low_wm_notif)
+			schedule_notify(lcid, SMUX_LOW_WM_HIT, NULL);
+
+		/* send the packet */
+		smux_tx_pkt(ch, pkt);
+		smux_free_pkt(pkt);
+	}
+}
+
+
+/**********************************************************************/
+/* Kernel API                                                         */
+/**********************************************************************/
+
+/**
+ * Set or clear channel option using the SMUX_CH_OPTION_* channel
+ * flags.
+ *
+ * @lcid   Logical channel ID
+ * @set    Options to set
+ * @clear  Options to clear
+ *
+ * @returns 0 for success, < 0 for failure
+ */
+int msm_smux_set_ch_option(uint8_t lcid, uint32_t set, uint32_t clear)
+{
+	unsigned long flags;
+	struct smux_lch_t *ch;
+	int tx_ready = 0;
+	int ret = 0;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+
+	/* Local loopback mode */
+	if (set & SMUX_CH_OPTION_LOCAL_LOOPBACK)
+		ch->local_mode = SMUX_LCH_MODE_LOCAL_LOOPBACK;
+
+	if (clear & SMUX_CH_OPTION_LOCAL_LOOPBACK)
+		ch->local_mode = SMUX_LCH_MODE_NORMAL;
+
+	/* Remote loopback mode */
+	if (set & SMUX_CH_OPTION_REMOTE_LOOPBACK)
+		ch->local_mode = SMUX_LCH_MODE_REMOTE_LOOPBACK;
+
+	if (clear & SMUX_CH_OPTION_REMOTE_LOOPBACK)
+		ch->local_mode = SMUX_LCH_MODE_NORMAL;
+
+	/* Flow control */
+	if (set & SMUX_CH_OPTION_REMOTE_TX_STOP) {
+		ch->local_tiocm |= SMUX_CMD_STATUS_FLOW_CNTL;
+		ret = smux_send_status_cmd(ch);
+		tx_ready = 1;
+	}
+
+	if (clear & SMUX_CH_OPTION_REMOTE_TX_STOP) {
+		ch->local_tiocm &= ~SMUX_CMD_STATUS_FLOW_CNTL;
+		ret = smux_send_status_cmd(ch);
+		tx_ready = 1;
+	}
+
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/**
+ * Starts the opening sequence for a logical channel.
+ *
+ * @lcid          Logical channel ID
+ * @priv          Free for client usage
+ * @notify        Event notification function
+ * @get_rx_buffer Function used to provide a receive buffer to SMUX
+ *
+ * @returns 0 for success, <0 otherwise
+ *
+ * A channel must be fully closed (either not previously opened or
+ * msm_smux_close() has been called and the SMUX_DISCONNECTED has been
+ * received.
+ *
+ * One the remote side is opened, the client will receive a SMUX_CONNECTED
+ * event.
+ */
+int msm_smux_open(uint8_t lcid, void *priv,
+	void (*notify)(void *priv, int event_type, const void *metadata),
+	int (*get_rx_buffer)(void *priv, void **pkt_priv, void **buffer,
+								int size))
+{
+	int ret;
+	struct smux_lch_t *ch;
+	struct smux_pkt_t *pkt;
+	int tx_ready = 0;
+	unsigned long flags;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+
+	if (ch->local_state == SMUX_LCH_LOCAL_CLOSING) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	if (ch->local_state != SMUX_LCH_LOCAL_CLOSED) {
+		pr_err("%s: open lcid %d local state %x invalid\n",
+				__func__, lcid, ch->local_state);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	SMUX_DBG("lcid %d local state 0x%x -> 0x%x\n", lcid,
+			ch->local_state,
+			SMUX_LCH_LOCAL_OPENING);
+
+	ch->local_state = SMUX_LCH_LOCAL_OPENING;
+
+	ch->priv = priv;
+	ch->notify = notify;
+	ch->get_rx_buffer = get_rx_buffer;
+	ret = 0;
+
+	/* Send Open Command */
+	pkt = smux_alloc_pkt();
+	if (!pkt) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	pkt->hdr.magic = SMUX_MAGIC;
+	pkt->hdr.cmd = SMUX_CMD_OPEN_LCH;
+	pkt->hdr.flags = SMUX_CMD_OPEN_POWER_COLLAPSE;
+	if (ch->local_mode == SMUX_LCH_MODE_REMOTE_LOOPBACK)
+		pkt->hdr.flags |= SMUX_CMD_OPEN_REMOTE_LOOPBACK;
+	pkt->hdr.lcid = lcid;
+	pkt->hdr.payload_len = 0;
+	pkt->hdr.pad_len = 0;
+	smux_tx_queue(pkt, ch, 0);
+	tx_ready = 1;
+
+out:
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+	if (tx_ready)
+		list_channel(ch);
+	return ret;
+}
+
+/**
+ * Starts the closing sequence for a logical channel.
+ *
+ * @lcid    Logical channel ID
+ *
+ * @returns 0 for success, <0 otherwise
+ *
+ * Once the close event has been acknowledge by the remote side, the client
+ * will receive a SMUX_DISCONNECTED notification.
+ */
+int msm_smux_close(uint8_t lcid)
+{
+	int ret = 0;
+	struct smux_lch_t *ch;
+	struct smux_pkt_t *pkt;
+	int tx_ready = 0;
+	unsigned long flags;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+	ch->local_tiocm = 0x0;
+	ch->remote_tiocm = 0x0;
+	ch->tx_pending_data_cnt = 0;
+	ch->notify_lwm = 0;
+
+	/* Purge TX queue */
+	spin_lock(&ch->tx_lock_lhb2);
+	while (!list_empty(&ch->tx_queue)) {
+		pkt = list_first_entry(&ch->tx_queue, struct smux_pkt_t,
+							list);
+		list_del(&pkt->list);
+
+		if (pkt->hdr.cmd == SMUX_CMD_OPEN_LCH) {
+			/* Open was never sent, just force to closed state */
+			union notifier_metadata meta_disconnected;
+
+			ch->local_state = SMUX_LCH_LOCAL_CLOSED;
+			meta_disconnected.disconnected.is_ssr = 0;
+			schedule_notify(lcid, SMUX_DISCONNECTED,
+				&meta_disconnected);
+		} else if (pkt->hdr.cmd == SMUX_CMD_DATA) {
+			/* Notify client of failed write */
+			union notifier_metadata meta_write;
+
+			meta_write.write.pkt_priv = pkt->priv;
+			meta_write.write.buffer = pkt->payload;
+			meta_write.write.len = pkt->hdr.payload_len;
+			schedule_notify(ch->lcid, SMUX_WRITE_FAIL, &meta_write);
+		}
+		smux_free_pkt(pkt);
+	}
+	spin_unlock(&ch->tx_lock_lhb2);
+
+	/* Send Close Command */
+	if (ch->local_state == SMUX_LCH_LOCAL_OPENED ||
+		ch->local_state == SMUX_LCH_LOCAL_OPENING) {
+		SMUX_DBG("lcid %d local state 0x%x -> 0x%x\n", lcid,
+				ch->local_state,
+				SMUX_LCH_LOCAL_CLOSING);
+
+		ch->local_state = SMUX_LCH_LOCAL_CLOSING;
+		pkt = smux_alloc_pkt();
+		if (pkt) {
+			pkt->hdr.cmd = SMUX_CMD_CLOSE_LCH;
+			pkt->hdr.flags = 0;
+			pkt->hdr.lcid = lcid;
+			pkt->hdr.payload_len = 0;
+			pkt->hdr.pad_len = 0;
+			smux_tx_queue(pkt, ch, 0);
+			tx_ready = 1;
+		} else {
+			pr_err("%s: pkt allocation failed\n", __func__);
+			ret = -ENOMEM;
+		}
+	}
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/**
+ * Write data to a logical channel.
+ *
+ * @lcid      Logical channel ID
+ * @pkt_priv  Client data that will be returned with the SMUX_WRITE_DONE or
+ *            SMUX_WRITE_FAIL notification.
+ * @data      Data to write
+ * @len       Length of @data
+ *
+ * @returns   0 for success, <0 otherwise
+ *
+ * Data may be written immediately after msm_smux_open() is called,
+ * but the data will wait in the transmit queue until the channel has
+ * been fully opened.
+ *
+ * Once the data has been written, the client will receive either a completion
+ * (SMUX_WRITE_DONE) or a failure notice (SMUX_WRITE_FAIL).
+ */
+int msm_smux_write(uint8_t lcid, void *pkt_priv, const void *data, int len)
+{
+	struct smux_lch_t *ch;
+	struct smux_pkt_t *pkt;
+	int tx_ready = 0;
+	unsigned long flags;
+	int ret;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+
+	if (ch->local_state != SMUX_LCH_LOCAL_OPENED &&
+		ch->local_state != SMUX_LCH_LOCAL_OPENING) {
+		pr_err("%s: hdr.invalid local state %d channel %d\n",
+					__func__, ch->local_state, lcid);
+		ret = -EINVAL;
+		goto out;
+	}
+
+	if (len > SMUX_MAX_PKT_SIZE - sizeof(struct smux_hdr_t)) {
+		pr_err("%s: payload %d too large\n",
+				__func__, len);
+		ret = -E2BIG;
+		goto out;
+	}
+
+	pkt = smux_alloc_pkt();
+	if (!pkt) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	pkt->hdr.cmd = SMUX_CMD_DATA;
+	pkt->hdr.lcid = lcid;
+	pkt->hdr.flags = 0;
+	pkt->hdr.payload_len = len;
+	pkt->payload = (void *)data;
+	pkt->priv = pkt_priv;
+	pkt->hdr.pad_len = 0;
+
+	spin_lock(&ch->tx_lock_lhb2);
+	/* verify high watermark */
+	SMUX_DBG("%s: pending %d", __func__, ch->tx_pending_data_cnt);
+
+	if (ch->tx_pending_data_cnt >= SMUX_WM_HIGH) {
+		pr_err("%s: ch %d high watermark %d exceeded %d\n",
+				__func__, lcid, SMUX_WM_HIGH,
+				ch->tx_pending_data_cnt);
+		ret = -EAGAIN;
+		goto out_inner;
+	}
+
+	/* queue packet for transmit */
+	if (++ch->tx_pending_data_cnt == SMUX_WM_HIGH) {
+		ch->notify_lwm = 1;
+		pr_err("%s: high watermark hit\n", __func__);
+		schedule_notify(lcid, SMUX_HIGH_WM_HIT, NULL);
+	}
+	list_add_tail(&pkt->list, &ch->tx_queue);
+
+	/* add to ready list */
+	if (IS_FULLY_OPENED(ch))
+		tx_ready = 1;
+
+	ret = 0;
+
+out_inner:
+	spin_unlock(&ch->tx_lock_lhb2);
+
+out:
+	if (ret)
+		smux_free_pkt(pkt);
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/**
+ * Returns true if the TX queue is currently full (high water mark).
+ *
+ * @lcid      Logical channel ID
+ * @returns   0 if channel is not full
+ *            1 if it is full
+ *            < 0 for error
+ */
+int msm_smux_is_ch_full(uint8_t lcid)
+{
+	struct smux_lch_t *ch;
+	unsigned long flags;
+	int is_full = 0;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+
+	spin_lock_irqsave(&ch->tx_lock_lhb2, flags);
+	if (ch->tx_pending_data_cnt >= SMUX_WM_HIGH)
+		is_full = 1;
+	spin_unlock_irqrestore(&ch->tx_lock_lhb2, flags);
+
+	return is_full;
+}
+
+/**
+ * Returns true if the TX queue has space for more packets it is at or
+ * below the low water mark).
+ *
+ * @lcid      Logical channel ID
+ * @returns   0 if channel is above low watermark
+ *            1 if it's at or below the low watermark
+ *            < 0 for error
+ */
+int msm_smux_is_ch_low(uint8_t lcid)
+{
+	struct smux_lch_t *ch;
+	unsigned long flags;
+	int is_low = 0;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+
+	spin_lock_irqsave(&ch->tx_lock_lhb2, flags);
+	if (ch->tx_pending_data_cnt <= SMUX_WM_LOW)
+		is_low = 1;
+	spin_unlock_irqrestore(&ch->tx_lock_lhb2, flags);
+
+	return is_low;
+}
+
+/**
+ * Send TIOCM status update.
+ *
+ * @ch  Channel for update
+ *
+ * @returns 0 for success, <0 for failure
+ *
+ * Channel lock must be held before calling.
+ */
+static int smux_send_status_cmd(struct smux_lch_t *ch)
+{
+	struct smux_pkt_t *pkt;
+
+	if (!ch)
+		return -EINVAL;
+
+	pkt = smux_alloc_pkt();
+	if (!pkt)
+		return -ENOMEM;
+
+	pkt->hdr.lcid = ch->lcid;
+	pkt->hdr.cmd = SMUX_CMD_STATUS;
+	pkt->hdr.flags = ch->local_tiocm;
+	pkt->hdr.payload_len = 0;
+	pkt->hdr.pad_len = 0;
+	smux_tx_queue(pkt, ch, 0);
+
+	return 0;
+}
+
+/**
+ * Internal helper function for getting the TIOCM status with
+ * state_lock_lhb1 already locked.
+ *
+ * @ch      Channel pointer
+ *
+ * @returns TIOCM status
+ */
+static long msm_smux_tiocm_get_atomic(struct smux_lch_t *ch)
+{
+	long status = 0x0;
+
+	status |= (ch->remote_tiocm & SMUX_CMD_STATUS_RTC) ? TIOCM_DSR : 0;
+	status |= (ch->remote_tiocm & SMUX_CMD_STATUS_RTR) ? TIOCM_CTS : 0;
+	status |= (ch->remote_tiocm & SMUX_CMD_STATUS_RI) ? TIOCM_RI : 0;
+	status |= (ch->remote_tiocm & SMUX_CMD_STATUS_DCD) ? TIOCM_CD : 0;
+
+	status |= (ch->local_tiocm & SMUX_CMD_STATUS_RTC) ? TIOCM_DTR : 0;
+	status |= (ch->local_tiocm & SMUX_CMD_STATUS_RTR) ? TIOCM_RTS : 0;
+
+	return status;
+}
+
+/**
+ * Get the TIOCM status bits.
+ *
+ * @lcid      Logical channel ID
+ *
+ * @returns   >= 0 TIOCM status bits
+ *            < 0  Error condition
+ */
+long msm_smux_tiocm_get(uint8_t lcid)
+{
+	struct smux_lch_t *ch;
+	unsigned long flags;
+	long status = 0x0;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+	status = msm_smux_tiocm_get_atomic(ch);
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+
+	return status;
+}
+
+/**
+ * Set/clear the TIOCM status bits.
+ *
+ * @lcid      Logical channel ID
+ * @set       Bits to set
+ * @clear     Bits to clear
+ *
+ * @returns   0 for success; < 0 for failure
+ *
+ * If a bit is specified in both the @set and @clear masks, then the clear bit
+ * definition will dominate and the bit will be cleared.
+ */
+int msm_smux_tiocm_set(uint8_t lcid, uint32_t set, uint32_t clear)
+{
+	struct smux_lch_t *ch;
+	unsigned long flags;
+	uint8_t old_status;
+	uint8_t status_set = 0x0;
+	uint8_t status_clear = 0x0;
+	int tx_ready = 0;
+	int ret = 0;
+
+	if (smux_assert_lch_id(lcid))
+		return -ENXIO;
+
+	ch = &smux_lch[lcid];
+	spin_lock_irqsave(&ch->state_lock_lhb1, flags);
+
+	status_set |= (set & TIOCM_DTR) ? SMUX_CMD_STATUS_RTC : 0;
+	status_set |= (set & TIOCM_RTS) ? SMUX_CMD_STATUS_RTR : 0;
+	status_set |= (set & TIOCM_RI) ? SMUX_CMD_STATUS_RI : 0;
+	status_set |= (set & TIOCM_CD) ? SMUX_CMD_STATUS_DCD : 0;
+
+	status_clear |= (clear & TIOCM_DTR) ? SMUX_CMD_STATUS_RTC : 0;
+	status_clear |= (clear & TIOCM_RTS) ? SMUX_CMD_STATUS_RTR : 0;
+	status_clear |= (clear & TIOCM_RI) ? SMUX_CMD_STATUS_RI : 0;
+	status_clear |= (clear & TIOCM_CD) ? SMUX_CMD_STATUS_DCD : 0;
+
+	old_status = ch->local_tiocm;
+	ch->local_tiocm |= status_set;
+	ch->local_tiocm &= ~status_clear;
+
+	if (ch->local_tiocm != old_status) {
+		ret = smux_send_status_cmd(ch);
+		tx_ready = 1;
+	}
+	spin_unlock_irqrestore(&ch->state_lock_lhb1, flags);
+
+	if (tx_ready)
+		list_channel(ch);
+
+	return ret;
+}
+
+/**********************************************************************/
+/* Line Discipline Interface                                          */
+/**********************************************************************/
+static int smuxld_open(struct tty_struct *tty)
+{
+	int i;
+	int tmp;
+	unsigned long flags;
+	int ret = 0;
+
+	if (!smux.is_initialized)
+		return -ENODEV;
+
+	spin_lock_irqsave(&smux.lock_lha0, flags);
+	if (smux.ld_open_count) {
+		pr_err("%s: %p multiple instances not supported\n",
+			__func__, tty);
+		ret = -EEXIST;
+		goto out;
+	}
+
+	++smux.ld_open_count;
+	if (tty->ops->write == NULL) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/* connect to TTY */
+	smux.tty = tty;
+	tty->disc_data = &smux;
+	tty->receive_room = TTY_RECEIVE_ROOM;
+	tty_driver_flush_buffer(tty);
+
+	/* power-down the UART if we are idle */
+	spin_lock(&smux.tx_lock_lha2);
+	if (smux.power_state == SMUX_PWR_OFF) {
+		SMUX_DBG("%s: powering off uart\n", __func__);
+		smux.power_state = SMUX_PWR_OFF_FLUSH;
+		spin_unlock(&smux.tx_lock_lha2);
+		queue_work(smux_tx_wq, &smux_inactivity_work);
+	} else {
+		spin_unlock(&smux.tx_lock_lha2);
+	}
+
+	/* register platform devices */
+	for (i = 0; i < ARRAY_SIZE(smux_devs); ++i) {
+		tmp = platform_device_register(&smux_devs[i]);
+		if (tmp)
+			pr_err("%s: error %d registering device %s\n",
+				   __func__, tmp, smux_devs[i].name);
+	}
+
+out:
+	spin_unlock_irqrestore(&smux.lock_lha0, flags);
+	return ret;
+}
+
+static void smuxld_close(struct tty_struct *tty)
+{
+	unsigned long flags;
+	int i;
+
+	spin_lock_irqsave(&smux.lock_lha0, flags);
+	if (smux.ld_open_count <= 0) {
+		pr_err("%s: invalid ld count %d\n", __func__,
+			smux.ld_open_count);
+		goto out;
+	}
+
+	for (i = 0; i < ARRAY_SIZE(smux_devs); ++i)
+		platform_device_unregister(&smux_devs[i]);
+
+	--smux.ld_open_count;
+
+out:
+	spin_unlock_irqrestore(&smux.lock_lha0, flags);
+}
+
+/**
+ * Receive data from TTY Line Discipline.
+ *
+ * @tty  TTY structure
+ * @cp   Character data
+ * @fp   Flag data
+ * @count Size of character and flag data
+ */
+void smuxld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+			   char *fp, int count)
+{
+	int i;
+	int last_idx = 0;
+	const char *tty_name = NULL;
+	char *f;
+
+	if (smux_debug_mask & MSM_SMUX_DEBUG)
+		print_hex_dump(KERN_INFO, "smux tty rx: ", DUMP_PREFIX_OFFSET,
+				     16, 1, cp, count, true);
+
+	/* verify error flags */
+	for (i = 0, f = fp; i < count; ++i, ++f) {
+		if (*f != TTY_NORMAL) {
+			if (tty)
+				tty_name = tty->name;
+			pr_err("%s: TTY %s Error %d (%s)\n", __func__,
+				   tty_name, *f, tty_flag_to_str(*f));
+
+			/* feed all previous valid data to the parser */
+			smux_rx_state_machine(cp + last_idx, i - last_idx,
+					TTY_NORMAL);
+
+			/* feed bad data to parser */
+			smux_rx_state_machine(cp + i, 1, *f);
+			last_idx = i + 1;
+		}
+	}
+
+	/* feed data to RX state machine */
+	smux_rx_state_machine(cp + last_idx, count - last_idx, TTY_NORMAL);
+}
+
+static void smuxld_flush_buffer(struct tty_struct *tty)
+{
+	pr_err("%s: not supported\n", __func__);
+}
+
+static ssize_t	smuxld_chars_in_buffer(struct tty_struct *tty)
+{
+	pr_err("%s: not supported\n", __func__);
+	return -ENODEV;
+}
+
+static ssize_t	smuxld_read(struct tty_struct *tty, struct file *file,
+		unsigned char __user *buf, size_t nr)
+{
+	pr_err("%s: not supported\n", __func__);
+	return -ENODEV;
+}
+
+static ssize_t	smuxld_write(struct tty_struct *tty, struct file *file,
+		 const unsigned char *buf, size_t nr)
+{
+	pr_err("%s: not supported\n", __func__);
+	return -ENODEV;
+}
+
+static int	smuxld_ioctl(struct tty_struct *tty, struct file *file,
+		 unsigned int cmd, unsigned long arg)
+{
+	pr_err("%s: not supported\n", __func__);
+	return -ENODEV;
+}
+
+static unsigned int smuxld_poll(struct tty_struct *tty, struct file *file,
+			 struct poll_table_struct *tbl)
+{
+	pr_err("%s: not supported\n", __func__);
+	return -ENODEV;
+}
+
+static void smuxld_write_wakeup(struct tty_struct *tty)
+{
+	pr_err("%s: not supported\n", __func__);
+}
+
+static struct tty_ldisc_ops smux_ldisc_ops = {
+	.owner           = THIS_MODULE,
+	.magic           = TTY_LDISC_MAGIC,
+	.name            = "n_smux",
+	.open            = smuxld_open,
+	.close           = smuxld_close,
+	.flush_buffer    = smuxld_flush_buffer,
+	.chars_in_buffer = smuxld_chars_in_buffer,
+	.read            = smuxld_read,
+	.write           = smuxld_write,
+	.ioctl           = smuxld_ioctl,
+	.poll            = smuxld_poll,
+	.receive_buf     = smuxld_receive_buf,
+	.write_wakeup    = smuxld_write_wakeup
+};
+
+static int __init smux_init(void)
+{
+	int ret;
+
+	spin_lock_init(&smux.lock_lha0);
+
+	spin_lock_init(&smux.rx_lock_lha1);
+	smux.rx_state = SMUX_RX_IDLE;
+	smux.power_state = SMUX_PWR_OFF;
+	smux.pwr_wakeup_delay_us = 1;
+	smux.powerdown_enabled = 0;
+	smux.rx_activity_flag = 0;
+	smux.tx_activity_flag = 0;
+	smux.recv_len = 0;
+	smux.tty = NULL;
+	smux.ld_open_count = 0;
+	smux.in_reset = 0;
+	smux.is_initialized = 1;
+	smux_byte_loopback = 0;
+
+	spin_lock_init(&smux.tx_lock_lha2);
+	INIT_LIST_HEAD(&smux.lch_tx_ready_list);
+
+	ret	= tty_register_ldisc(N_SMUX, &smux_ldisc_ops);
+	if (ret != 0) {
+		pr_err("%s: error %d registering line discipline\n",
+				__func__, ret);
+		return ret;
+	}
+
+	ret = lch_init();
+	if (ret != 0) {
+		pr_err("%s: lch_init failed\n", __func__);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit smux_exit(void)
+{
+	int ret;
+
+	ret	= tty_unregister_ldisc(N_SMUX);
+	if (ret != 0) {
+		pr_err("%s error %d unregistering line discipline\n",
+				__func__, ret);
+		return;
+	}
+}
+
+module_init(smux_init);
+module_exit(smux_exit);
+
+MODULE_DESCRIPTION("Serial Mux TTY Line Discipline");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS_LDISC(N_SMUX);
diff --git a/drivers/tty/smux_ctl.c b/drivers/tty/smux_ctl.c
new file mode 100644
index 0000000..26a49a0
--- /dev/null
+++ b/drivers/tty/smux_ctl.c
@@ -0,0 +1,938 @@
+/* Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * Serial Mux Control Driver -- Provides a binary serial muxed control
+ * port interface.
+ */
+
+#define DEBUG
+
+#include <linux/cdev.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/uaccess.h>
+#include <linux/workqueue.h>
+#include <linux/atomic.h>
+#include <linux/platform_device.h>
+#include <linux/smux.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+
+#include <asm/ioctls.h>
+
+#define MAX_WRITE_RETRY 5
+#define MAGIC_NO_V1 0x33FC
+#define DEVICE_NAME "smuxctl"
+#define SMUX_CTL_MAX_BUF_SIZE 2048
+#define SMUX_CTL_MODULE_NAME "smux_ctl"
+#define DEBUG
+#define DEBUG_LOOPBACK
+
+static int msm_smux_ctl_debug_mask;
+module_param_named(debug_mask, msm_smux_ctl_debug_mask,
+	int, S_IRUGO | S_IWUSR | S_IWGRP);
+
+static uint32_t smux_ctl_ch_id[] = {
+	SMUX_DATA_CTL_0,
+	SMUX_DATA_CTL_1,
+	SMUX_DATA_CTL_2,
+	SMUX_DATA_CTL_3,
+	SMUX_DATA_CTL_4,
+	SMUX_DATA_CTL_5,
+	SMUX_DATA_CTL_6,
+	SMUX_DATA_CTL_7,
+	SMUX_USB_RMNET_CTL_0,
+	SMUX_CSVT_CTL_0
+};
+
+#define SMUX_CTL_NUM_CHANNELS ARRAY_SIZE(smux_ctl_ch_id)
+
+struct smux_ctl_dev {
+	int id;
+	char name[10];
+	struct cdev cdev;
+	struct device *devicep;
+	struct mutex dev_lock;
+	atomic_t ref_count;
+	int state;
+	int is_channel_reset;
+	int is_high_wm;
+	int write_pending;
+
+	struct mutex rx_lock;
+	uint32_t read_avail;
+	struct list_head rx_list;
+
+	wait_queue_head_t read_wait_queue;
+	wait_queue_head_t write_wait_queue;
+
+	struct {
+		uint32_t bytes_tx;
+		uint32_t bytes_rx;
+		uint32_t pkts_tx;
+		uint32_t pkts_rx;
+		uint32_t cnt_ssr;
+		uint32_t cnt_read_fail;
+		uint32_t cnt_write_fail;
+		uint32_t cnt_high_wm_hit;
+	} stats;
+
+} *smux_ctl_devp[SMUX_CTL_NUM_CHANNELS];
+
+struct smux_ctl_pkt {
+	int data_size;
+	void *data;
+};
+
+struct smux_ctl_list_elem {
+	struct list_head list;
+	struct smux_ctl_pkt ctl_pkt;
+};
+
+struct class *smux_ctl_classp;
+static dev_t smux_ctl_number;
+static uint32_t smux_ctl_inited;
+
+enum {
+	MSM_SMUX_CTL_DEBUG = 1U << 0,
+	MSM_SMUX_CTL_DUMP_BUFFER = 1U << 1,
+};
+
+#if defined(DEBUG)
+
+static const char *smux_ctl_event_str[] = {
+	"SMUX_CONNECTED",
+	"SMUX_DISCONNECTED",
+	"SMUX_READ_DONE",
+	"SMUX_READ_FAIL",
+	"SMUX_WRITE_DONE",
+	"SMUX_WRITE_FAIL",
+	"SMUX_TIOCM_UPDATE",
+	"SMUX_LOW_WM_HIT",
+	"SMUX_HIGH_WM_HIT",
+};
+
+#define SMUXCTL_DUMP_BUFFER(prestr, cnt, buf) \
+do { \
+	if (msm_smux_ctl_debug_mask & MSM_SMUX_CTL_DUMP_BUFFER) { \
+		int i; \
+		pr_err("%s", prestr); \
+		for (i = 0; i < cnt; i++) \
+			pr_err("%.2x", buf[i]); \
+		pr_err("\n"); \
+	} \
+} while (0)
+
+#define SMUXCTL_DBG(x...) \
+do { \
+	if (msm_smux_ctl_debug_mask & MSM_SMUX_CTL_DEBUG) \
+		pr_err(x); \
+} while (0)
+
+
+#else
+#define SMUXCTL_DUMP_BUFFER(prestr, cnt, buf) do {} while (0)
+#define SMUXCTL_DBG(x...) do {} while (0)
+#endif
+
+#if defined(DEBUG_LOOPBACK)
+#define SMUXCTL_SET_LOOPBACK(lcid) \
+	msm_smux_set_ch_option(lcid, SMUX_CH_OPTION_LOCAL_LOOPBACK, 0)
+#else
+#define SMUXCTL_SET_LOOPBACK(lcid) do {} while (0)
+#endif
+
+static int get_ctl_dev_index(int id)
+{
+	int dev_index;
+	for (dev_index = 0; dev_index < SMUX_CTL_NUM_CHANNELS; dev_index++) {
+		if (smux_ctl_ch_id[dev_index] == id)
+			return dev_index;
+	}
+	return -ENODEV;
+}
+
+static int smux_ctl_get_rx_buf_cb(void *priv, void **pkt_priv,
+		void **buffer, int size)
+{
+	void *buf = NULL;
+	int id = ((struct smux_ctl_dev *)(priv))->id;
+	int dev_index;
+
+	if (id < 0 || id > smux_ctl_ch_id[SMUX_CTL_NUM_CHANNELS - 1])
+		return -ENODEV;
+
+	if (!buffer || 0 >= size)
+		return -EINVAL;
+
+	dev_index = get_ctl_dev_index(id);
+	if (dev_index < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: Ch%d is not "
+					"exported to user-space\n",
+				__func__, id);
+		return -ENODEV;
+	}
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s: Allocating Rx buf size %d "
+			"for ch%d\n",
+			__func__, size, smux_ctl_devp[dev_index]->id);
+
+	buf = kmalloc(size, GFP_KERNEL);
+	if (!buf) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: buffer allocation failed: "
+				"Ch%d, size %d ", __func__, id, size);
+		return -ENOMEM;
+	}
+
+	*buffer = buf;
+	*pkt_priv = NULL;
+	return 0;
+
+}
+
+void smux_ctl_notify_cb(void *priv, int event_type, const void *metadata)
+{
+	int id = ((struct smux_ctl_dev *)(priv))->id;
+	struct smux_ctl_list_elem *list_elem = NULL;
+	int dev_index;
+	void *data;
+	int len;
+
+	if (id < 0 || id > smux_ctl_ch_id[SMUX_CTL_NUM_CHANNELS - 1])
+		return;
+
+	dev_index = get_ctl_dev_index(id);
+	if (dev_index < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: Ch%d is not exported "
+				"to user-space\n", __func__, id);
+		return;
+	}
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s: Ch%d, Event %d (%s)\n",
+			__func__, smux_ctl_devp[dev_index]->id,
+				event_type, smux_ctl_event_str[event_type]);
+
+
+	switch (event_type) {
+	case SMUX_CONNECTED:
+		mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+		smux_ctl_devp[dev_index]->state = SMUX_CONNECTED;
+		smux_ctl_devp[dev_index]->is_high_wm = 0;
+		smux_ctl_devp[dev_index]->is_channel_reset = 0;
+		smux_ctl_devp[dev_index]->read_avail = 0;
+		mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+		wake_up(&smux_ctl_devp[dev_index]->write_wait_queue);
+		break;
+
+	case SMUX_DISCONNECTED:
+		mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+		smux_ctl_devp[dev_index]->state = SMUX_DISCONNECTED;
+		smux_ctl_devp[dev_index]->is_channel_reset =
+			((struct smux_meta_disconnected *)metadata)->is_ssr;
+		if (smux_ctl_devp[dev_index]->is_channel_reset)
+			smux_ctl_devp[dev_index]->stats.cnt_ssr++;
+		mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+		wake_up(&smux_ctl_devp[dev_index]->write_wait_queue);
+		wake_up(&smux_ctl_devp[dev_index]->read_wait_queue);
+		break;
+
+	case SMUX_READ_FAIL:
+		data = ((struct smux_meta_read *)metadata)->buffer;
+		kfree(data);
+		mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+		smux_ctl_devp[dev_index]->stats.cnt_read_fail++;
+		mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+		wake_up(&smux_ctl_devp[dev_index]->read_wait_queue);
+		break;
+
+	case SMUX_READ_DONE:
+		data = ((struct smux_meta_read *)metadata)->buffer;
+		len = ((struct smux_meta_read *)metadata)->len;
+
+		if (data && len > 0) {
+			list_elem = kmalloc(sizeof(struct smux_ctl_list_elem),
+							GFP_KERNEL);
+			if (list_elem) {
+				list_elem->ctl_pkt.data = data;
+				list_elem->ctl_pkt.data_size = len;
+
+				mutex_lock(&smux_ctl_devp[dev_index]->rx_lock);
+				list_add_tail(&list_elem->list,
+					&smux_ctl_devp[dev_index]->rx_list);
+				smux_ctl_devp[dev_index]->read_avail += len;
+				mutex_unlock(
+					&smux_ctl_devp[dev_index]->rx_lock);
+			} else {
+				kfree(data);
+			}
+		}
+
+		wake_up(&smux_ctl_devp[dev_index]->read_wait_queue);
+		break;
+
+	case SMUX_WRITE_DONE:
+		mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+		smux_ctl_devp[dev_index]->write_pending = 0;
+		mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+		data = ((struct smux_meta_write *)metadata)->buffer;
+		kfree(data);
+		wake_up(&smux_ctl_devp[dev_index]->write_wait_queue);
+		break;
+
+	case SMUX_WRITE_FAIL:
+		data = ((struct smux_meta_write *)metadata)->buffer;
+		kfree(data);
+		mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+		smux_ctl_devp[dev_index]->stats.cnt_write_fail++;
+		mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+		wake_up(&smux_ctl_devp[dev_index]->write_wait_queue);
+		break;
+
+	case SMUX_LOW_WM_HIT:
+		mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+		smux_ctl_devp[dev_index]->is_high_wm = 0;
+		mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+		wake_up(&smux_ctl_devp[dev_index]->write_wait_queue);
+		break;
+
+	case SMUX_HIGH_WM_HIT:
+		mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+		smux_ctl_devp[dev_index]->is_high_wm = 1;
+		smux_ctl_devp[dev_index]->stats.cnt_high_wm_hit++;
+		mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+		break;
+
+	case SMUX_TIOCM_UPDATE:
+	default:
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: Event %d not supported\n",
+				__func__, event_type);
+		break;
+
+	}
+
+}
+
+int smux_ctl_open(struct inode *inode, struct file *file)
+{
+	int r = 0;
+	struct smux_ctl_dev *devp;
+
+	if (!smux_ctl_inited)
+		return -EIO;
+
+	devp = container_of(inode->i_cdev, struct smux_ctl_dev, cdev);
+	if (!devp)
+		return -ENODEV;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s called on smuxctl%d device\n",
+			__func__, devp->id);
+
+	if (1 == atomic_add_return(1, &devp->ref_count)) {
+
+		SMUXCTL_SET_LOOPBACK(devp->id);
+		r = msm_smux_open(devp->id,
+				devp,
+				smux_ctl_notify_cb,
+				smux_ctl_get_rx_buf_cb);
+		if (r < 0) {
+			pr_err(SMUX_CTL_MODULE_NAME ": %s: smux_open failed "
+					"for smuxctl%d with rc %d\n",
+					__func__, devp->id, r);
+			atomic_dec(&devp->ref_count);
+			return r;
+		}
+
+		r = wait_event_interruptible_timeout(
+				devp->write_wait_queue,
+				(devp->state == SMUX_CONNECTED),
+				(5 * HZ));
+		if (r == 0)
+			r = -ETIMEDOUT;
+
+		if (r < 0) {
+			pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+				"SMUX open timed out: %d, LCID %d\n",
+			       __func__, r, devp->id);
+			atomic_dec(&devp->ref_count);
+			msm_smux_close(devp->id);
+			return r;
+
+		} else if (devp->state != SMUX_CONNECTED) {
+			pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+				"Invalid open notification\n", __func__);
+			r = -ENODEV;
+			atomic_dec(&devp->ref_count);
+			msm_smux_close(devp->id);
+			return r;
+		}
+	}
+
+	file->private_data = devp;
+	return 0;
+}
+
+int smux_ctl_release(struct inode *inode, struct file *file)
+{
+	struct smux_ctl_dev *devp;
+	struct smux_ctl_list_elem *list_elem = NULL;
+
+	devp = file->private_data;
+	if (!devp)
+		return -EINVAL;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s called on smuxctl%d device\n",
+			__func__, devp->id);
+
+	mutex_lock(&devp->dev_lock);
+	if (atomic_dec_and_test(&devp->ref_count)) {
+		mutex_lock(&devp->rx_lock);
+		while (!list_empty(&devp->rx_list)) {
+			list_elem = list_first_entry(
+					&devp->rx_list,
+					struct smux_ctl_list_elem,
+					list);
+			list_del(&list_elem->list);
+			kfree(list_elem->ctl_pkt.data);
+			kfree(list_elem);
+		}
+		devp->read_avail = 0;
+		mutex_unlock(&devp->rx_lock);
+		msm_smux_close(devp->id);
+	}
+	mutex_unlock(&devp->dev_lock);
+	file->private_data = NULL;
+
+	return 0;
+}
+
+static int smux_ctl_readable(int id)
+{
+	int r;
+	int dev_index;
+
+	if (id < 0 || id > smux_ctl_ch_id[SMUX_CTL_NUM_CHANNELS - 1])
+		return -ENODEV;
+
+	dev_index = get_ctl_dev_index(id);
+	if (dev_index < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: Ch%d "
+				"is not exported to user-space\n",
+			__func__, id);
+		return -ENODEV;
+	}
+
+	mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+
+	if (signal_pending(current))
+		r = -ERESTARTSYS;
+
+	if (smux_ctl_devp[dev_index]->state == SMUX_DISCONNECTED &&
+	    smux_ctl_devp[dev_index]->is_channel_reset != 0)
+		r = -ENETRESET;
+
+	else if (smux_ctl_devp[dev_index]->state != SMUX_CONNECTED)
+		r = -ENODEV;
+
+	else
+		r = smux_ctl_devp[dev_index]->read_avail;
+
+
+	mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+
+	return r;
+
+}
+
+ssize_t smux_ctl_read(struct file *file,
+			char __user *buf,
+			size_t count,
+			loff_t *ppos)
+{
+	int r = 0, id, bytes_to_read, read_err;
+	struct smux_ctl_dev *devp;
+	struct smux_ctl_list_elem *list_elem = NULL;
+
+	devp = file->private_data;
+
+	if (!devp)
+		return -ENODEV;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s: read from ch%d\n",
+			__func__, devp->id);
+
+	id = devp->id;
+	mutex_lock(&devp->rx_lock);
+	while (devp->read_avail <= 0) {
+		mutex_unlock(&devp->rx_lock);
+		r = wait_event_interruptible(devp->read_wait_queue,
+				0 != (read_err = smux_ctl_readable(id)));
+
+		if (r < 0) {
+			pr_err(SMUX_CTL_MODULE_NAME ": %s:"
+					"wait_event_interruptible "
+					"ret %i\n", __func__, r);
+			return r;
+		}
+
+		if (read_err < 0) {
+			pr_err(SMUX_CTL_MODULE_NAME ": %s:"
+				" Read block failed for Ch%d, err %d\n",
+					__func__, devp->id, read_err);
+			return read_err;
+		}
+
+		mutex_lock(&devp->rx_lock);
+	}
+
+	if (list_empty(&devp->rx_list)) {
+		mutex_unlock(&devp->rx_lock);
+		SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s: "
+			"Nothing in ch%d's rx_list\n", __func__,
+			devp->id);
+		return -EAGAIN;
+	}
+
+	list_elem = list_first_entry(&devp->rx_list,
+			struct smux_ctl_list_elem, list);
+	bytes_to_read = (uint32_t)(list_elem->ctl_pkt.data_size);
+	if (bytes_to_read > count) {
+		mutex_unlock(&devp->rx_lock);
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+			"Packet size %d > buf size %d\n", __func__,
+			bytes_to_read, count);
+		return -ENOMEM;
+	}
+
+	if (copy_to_user(buf, list_elem->ctl_pkt.data, bytes_to_read)) {
+		mutex_unlock(&devp->rx_lock);
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+			"copy_to_user failed for ch%d\n", __func__,
+			devp->id);
+		return -EFAULT;
+	}
+
+	devp->read_avail -= bytes_to_read;
+	list_del(&list_elem->list);
+	kfree(list_elem->ctl_pkt.data);
+	kfree(list_elem);
+	devp->stats.pkts_rx++;
+	devp->stats.bytes_rx += bytes_to_read;
+	mutex_unlock(&devp->rx_lock);
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s: "
+		"Returning %d bytes to ch%d\n", __func__,
+			bytes_to_read, devp->id);
+	return bytes_to_read;
+}
+
+static int smux_ctl_writeable(int id)
+{
+	int r;
+	int dev_index;
+
+	if (id < 0 || id > smux_ctl_ch_id[SMUX_CTL_NUM_CHANNELS - 1])
+		return -ENODEV;
+
+	dev_index = get_ctl_dev_index(id);
+	if (dev_index < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+			"Ch%d is not exported to user-space\n",
+			__func__, id);
+		return -ENODEV;
+	}
+
+	mutex_lock(&smux_ctl_devp[dev_index]->dev_lock);
+
+	if (signal_pending(current))
+		r = -ERESTARTSYS;
+	else if (smux_ctl_devp[dev_index]->state == SMUX_DISCONNECTED &&
+	    smux_ctl_devp[dev_index]->is_channel_reset != 0)
+		r = -ENETRESET;
+	else if (smux_ctl_devp[dev_index]->state != SMUX_CONNECTED)
+		r = -ENODEV;
+	else if (smux_ctl_devp[dev_index]->is_high_wm ||
+			smux_ctl_devp[dev_index]->write_pending)
+		r = 0;
+	else
+		r = SMUX_CTL_MAX_BUF_SIZE;
+
+	mutex_unlock(&smux_ctl_devp[dev_index]->dev_lock);
+
+	return r;
+
+}
+
+ssize_t smux_ctl_write(struct file *file,
+		const char __user *buf,
+		size_t count,
+		loff_t *ppos)
+{
+	int r = 0, id, write_err;
+	char *temp_buf;
+	struct smux_ctl_dev *devp;
+
+	if (count <= 0)
+		return -EINVAL;
+
+	devp = file->private_data;
+	if (!devp)
+		return -ENODEV;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s: writing %i bytes on ch%d\n",
+			__func__, count, devp->id);
+
+	id = devp->id;
+	r = wait_event_interruptible(devp->write_wait_queue,
+			0 != (write_err = smux_ctl_writeable(id)));
+
+	if (r < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME
+				": %s: wait_event_interruptible "
+				"ret %i\n", __func__, r);
+		return r;
+	}
+
+	if (write_err < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s:"
+				"Write block failed for Ch%d, err %d\n",
+				__func__, devp->id, write_err);
+		return write_err;
+	}
+
+	temp_buf = kmalloc(count, GFP_KERNEL);
+	if (!temp_buf) {
+		pr_err(SMUX_CTL_MODULE_NAME
+				": %s: temp_buf alloc failed\n", __func__);
+		return -ENOMEM;
+	}
+
+	if (copy_from_user(temp_buf, buf, count)) {
+		pr_err(SMUX_CTL_MODULE_NAME
+				": %s: copy_from_user failed\n", __func__);
+		kfree(temp_buf);
+		return -EFAULT;
+	}
+
+	mutex_lock(&devp->dev_lock);
+	devp->write_pending = 1;
+	mutex_unlock(&devp->dev_lock);
+
+	r = msm_smux_write(id, NULL, (void *)temp_buf, count);
+	if (r < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME
+			": %s: smux_write on Ch%dfailed, err %d\n",
+				__func__, id, r);
+		mutex_lock(&devp->dev_lock);
+		devp->write_pending = 0;
+		mutex_unlock(&devp->dev_lock);
+		return r;
+	}
+
+	r = wait_event_interruptible(devp->write_wait_queue,
+			0 != (write_err = smux_ctl_writeable(id)));
+	if (r < 0) {
+		pr_err(SMUX_CTL_MODULE_NAME " :%s: wait_event_interruptible "
+				"ret %i\n", __func__, r);
+		mutex_lock(&devp->dev_lock);
+		devp->write_pending = 0;
+		mutex_unlock(&devp->dev_lock);
+		return r;
+	}
+
+	mutex_lock(&devp->dev_lock);
+	devp->write_pending = 0;
+	devp->stats.pkts_tx++;
+	devp->stats.bytes_tx += count;
+	mutex_unlock(&devp->dev_lock);
+	return count;
+}
+
+static long smux_ctl_ioctl(struct file *file, unsigned int cmd,
+				unsigned long arg)
+{
+	int ret;
+	struct smux_ctl_dev *devp;
+
+	devp = file->private_data;
+	if (!devp)
+		return -ENODEV;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s called on smuxctl%d device\n",
+			__func__, devp->id);
+
+	switch (cmd) {
+	case TIOCMGET:
+		ret = msm_smux_tiocm_get(devp->id);
+		break;
+	case TIOCMSET:
+		ret = msm_smux_tiocm_set(devp->id, arg, ~arg);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static const struct file_operations smux_ctl_fops = {
+	.owner = THIS_MODULE,
+	.open = smux_ctl_open,
+	.release = smux_ctl_release,
+	.read = smux_ctl_read,
+	.write = smux_ctl_write,
+	.unlocked_ioctl = smux_ctl_ioctl,
+};
+
+static int smux_ctl_probe(struct platform_device *pdev)
+{
+	int i;
+	int r;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s Begins\n", __func__);
+
+	for (i = 0; i < SMUX_CTL_NUM_CHANNELS; ++i) {
+		smux_ctl_devp[i] = kzalloc(sizeof(struct smux_ctl_dev),
+							GFP_KERNEL);
+		if (IS_ERR(smux_ctl_devp[i])) {
+			pr_err(SMUX_CTL_MODULE_NAME
+				 ": %s kmalloc() ENOMEM\n", __func__);
+			r = -ENOMEM;
+			goto error0;
+		}
+
+		smux_ctl_devp[i]->id = smux_ctl_ch_id[i];
+		atomic_set(&smux_ctl_devp[i]->ref_count, 0);
+		smux_ctl_devp[i]->is_high_wm = 0;
+		smux_ctl_devp[i]->write_pending = 0;
+		smux_ctl_devp[i]->is_channel_reset = 0;
+		smux_ctl_devp[i]->state = SMUX_DISCONNECTED;
+		smux_ctl_devp[i]->read_avail = 0;
+
+		smux_ctl_devp[i]->stats.bytes_tx = 0;
+		smux_ctl_devp[i]->stats.bytes_rx = 0;
+		smux_ctl_devp[i]->stats.pkts_tx = 0;
+		smux_ctl_devp[i]->stats.pkts_rx = 0;
+		smux_ctl_devp[i]->stats.cnt_ssr = 0;
+		smux_ctl_devp[i]->stats.cnt_read_fail = 0;
+		smux_ctl_devp[i]->stats.cnt_write_fail = 0;
+		smux_ctl_devp[i]->stats.cnt_high_wm_hit = 0;
+
+		mutex_init(&smux_ctl_devp[i]->dev_lock);
+		init_waitqueue_head(&smux_ctl_devp[i]->read_wait_queue);
+		init_waitqueue_head(&smux_ctl_devp[i]->write_wait_queue);
+		mutex_init(&smux_ctl_devp[i]->rx_lock);
+		INIT_LIST_HEAD(&smux_ctl_devp[i]->rx_list);
+	}
+
+	r = alloc_chrdev_region(&smux_ctl_number, 0, SMUX_CTL_NUM_CHANNELS,
+							DEVICE_NAME);
+	if (IS_ERR_VALUE(r)) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+				"alloc_chrdev_region() ret %i.\n",
+					 __func__, r);
+		goto error0;
+	}
+
+	smux_ctl_classp = class_create(THIS_MODULE, DEVICE_NAME);
+	if (IS_ERR(smux_ctl_classp)) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+				"class_create() ENOMEM\n", __func__);
+		r = -ENOMEM;
+		goto error1;
+	}
+
+	for (i = 0; i < SMUX_CTL_NUM_CHANNELS; ++i) {
+		cdev_init(&smux_ctl_devp[i]->cdev, &smux_ctl_fops);
+		smux_ctl_devp[i]->cdev.owner = THIS_MODULE;
+
+		r = cdev_add(&smux_ctl_devp[i]->cdev, (smux_ctl_number + i), 1);
+
+		if (IS_ERR_VALUE(r)) {
+			pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+					"cdev_add() ret %i\n", __func__, r);
+			kfree(smux_ctl_devp[i]);
+			goto error2;
+		}
+
+		smux_ctl_devp[i]->devicep =
+				device_create(smux_ctl_classp, NULL,
+					(smux_ctl_number + i), NULL,
+					DEVICE_NAME "%d", smux_ctl_ch_id[i]);
+
+		if (IS_ERR(smux_ctl_devp[i]->devicep)) {
+			pr_err(SMUX_CTL_MODULE_NAME ": %s: "
+					"device_create() ENOMEM\n", __func__);
+			r = -ENOMEM;
+			cdev_del(&smux_ctl_devp[i]->cdev);
+			kfree(smux_ctl_devp[i]);
+			goto error2;
+		}
+	}
+
+	smux_ctl_inited = 1;
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s: "
+		"SMUX Control Port Driver Initialized.\n", __func__);
+	return 0;
+
+error2:
+	while (--i >= 0) {
+		cdev_del(&smux_ctl_devp[i]->cdev);
+		device_destroy(smux_ctl_classp,
+			MKDEV(MAJOR(smux_ctl_number), i));
+	}
+
+	class_destroy(smux_ctl_classp);
+	i = SMUX_CTL_NUM_CHANNELS;
+
+error1:
+	unregister_chrdev_region(MAJOR(smux_ctl_number),
+			SMUX_CTL_NUM_CHANNELS);
+
+error0:
+	while (--i >= 0)
+		kfree(smux_ctl_devp[i]);
+
+	return r;
+}
+
+static int smux_ctl_remove(struct platform_device *pdev)
+{
+	int i;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s Begins\n", __func__);
+
+	for (i = 0; i < SMUX_CTL_NUM_CHANNELS; ++i) {
+		cdev_del(&smux_ctl_devp[i]->cdev);
+		kfree(smux_ctl_devp[i]);
+		device_destroy(smux_ctl_classp,
+			MKDEV(MAJOR(smux_ctl_number), i));
+	}
+	class_destroy(smux_ctl_classp);
+	unregister_chrdev_region(MAJOR(smux_ctl_number),
+			SMUX_CTL_NUM_CHANNELS);
+
+	return 0;
+}
+
+static struct platform_driver smux_ctl_driver = {
+	.probe = smux_ctl_probe,
+	.remove = smux_ctl_remove,
+	.driver = {
+		.name = "SMUX_CTL",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int __init smux_ctl_init(void)
+{
+	msm_smux_ctl_debug_mask = MSM_SMUX_CTL_DEBUG | MSM_SMUX_CTL_DUMP_BUFFER;
+
+	SMUXCTL_DBG(SMUX_CTL_MODULE_NAME ": %s Begins\n", __func__);
+	return platform_driver_register(&smux_ctl_driver);
+}
+
+
+#if defined(CONFIG_DEBUG_FS)
+
+#define DEBUG_BUFMAX 4096
+static char debug_buffer[DEBUG_BUFMAX];
+
+static ssize_t debug_read(struct file *file, char __user *buf,
+				size_t count, loff_t *ppos)
+{
+	int bsize = 0;
+	int i;
+	if (!smux_ctl_inited) {
+		pr_err(SMUX_CTL_MODULE_NAME ": %s: SMUX_CTL not yet inited\n",
+				__func__);
+		return -EIO;
+	}
+
+	bsize += scnprintf(debug_buffer + bsize, DEBUG_BUFMAX - bsize,
+				"SMUX_CTL Channel States:\n");
+
+	for (i = 0; i < SMUX_CTL_NUM_CHANNELS; ++i) {
+		bsize += scnprintf(debug_buffer + bsize, DEBUG_BUFMAX - bsize,
+		"Ch%02d %s RefCnt=%01d State=%02d "
+		"SSR=%02d HighWM=%02d ReadAvail=%04d WritePending=%02d\n",
+		smux_ctl_devp[i]->id,
+		smux_ctl_devp[i]->name,
+		atomic_read(&smux_ctl_devp[i]->ref_count),
+		smux_ctl_devp[i]->state,
+		smux_ctl_devp[i]->is_channel_reset,
+		smux_ctl_devp[i]->is_high_wm,
+		smux_ctl_devp[i]->read_avail,
+		smux_ctl_devp[i]->write_pending);
+	}
+
+	bsize += scnprintf(debug_buffer + bsize, DEBUG_BUFMAX - bsize,
+				"\nSMUX_CTL Channel Statistics:\n");
+	for (i = 0; i < SMUX_CTL_NUM_CHANNELS; ++i) {
+		bsize += scnprintf(debug_buffer + bsize, DEBUG_BUFMAX - bsize,
+			"Ch%02d %s BytesTX=%08d "
+				"BytesRx=%08d PktsTx=%04d PktsRx=%04d"
+			"CntSSR=%02d CntHighWM=%02d "
+				"CntReadFail%02d CntWriteFailed=%02d\n",
+			smux_ctl_devp[i]->id,
+			smux_ctl_devp[i]->name,
+			smux_ctl_devp[i]->stats.bytes_tx,
+			smux_ctl_devp[i]->stats.bytes_rx,
+			smux_ctl_devp[i]->stats.pkts_tx,
+			smux_ctl_devp[i]->stats.pkts_rx,
+			smux_ctl_devp[i]->stats.cnt_ssr,
+			smux_ctl_devp[i]->stats.cnt_high_wm_hit,
+			smux_ctl_devp[i]->stats.cnt_read_fail,
+			smux_ctl_devp[i]->stats.cnt_write_fail);
+	}
+
+	return simple_read_from_buffer(buf, count, ppos, debug_buffer, bsize);
+}
+
+static int debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static const struct file_operations debug_ops = {
+	.read = debug_read,
+	.open = debug_open,
+};
+
+static int __init smux_debugfs_init(void)
+{
+	struct dentry *dent;
+
+	dent = debugfs_create_dir("smux_ctl", 0);
+	if (!IS_ERR(dent))
+		debugfs_create_file("smux_ctl_state", 0444, dent,
+			NULL, &debug_ops);
+
+	return 0;
+}
+
+late_initcall(smux_debugfs_init);
+#endif
+
+module_init(smux_ctl_init);
+MODULE_DESCRIPTION("MSM SMUX Control Port");
+MODULE_LICENSE("GPL v2");
+
+
diff --git a/drivers/tty/smux_loopback.c b/drivers/tty/smux_loopback.c
new file mode 100644
index 0000000..52ce17f
--- /dev/null
+++ b/drivers/tty/smux_loopback.c
@@ -0,0 +1,289 @@
+/* drivers/tty/smux_loopback.c
+ *
+ * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/workqueue.h>
+#include <linux/kfifo.h>
+#include <linux/slab.h>
+#include <linux/smux.h>
+#include "smux_private.h"
+
+#define SMUX_LOOP_FIFO_SIZE	128
+
+static void smux_loopback_rx_worker(struct work_struct *work);
+static struct workqueue_struct *smux_loopback_wq;
+static DECLARE_WORK(smux_loopback_work, smux_loopback_rx_worker);
+static struct kfifo smux_loop_pkt_fifo;
+static DEFINE_SPINLOCK(hw_fn_lock);
+
+/**
+ * Initialize loopback framework (called by n_smux.c).
+ */
+int smux_loopback_init(void)
+{
+	int ret = 0;
+
+	spin_lock_init(&hw_fn_lock);
+	smux_loopback_wq = create_singlethread_workqueue("smux_loopback_wq");
+	if (IS_ERR(smux_loopback_wq)) {
+		pr_err("%s: failed to create workqueue\n", __func__);
+		return -ENOMEM;
+	}
+
+	ret |= kfifo_alloc(&smux_loop_pkt_fifo,
+			SMUX_LOOP_FIFO_SIZE * sizeof(struct smux_pkt_t *),
+			GFP_KERNEL);
+
+	return ret;
+}
+
+/**
+ * Simulate a write to the TTY hardware by duplicating
+ * the TX packet and putting it into the RX queue.
+ *
+ * @pkt     Packet to write
+ *
+ * @returns 0 on success
+ */
+int smux_tx_loopback(struct smux_pkt_t *pkt_ptr)
+{
+	struct smux_pkt_t *send_pkt;
+	unsigned long flags;
+	int i;
+	int ret;
+
+	/* duplicate packet */
+	send_pkt = smux_alloc_pkt();
+	send_pkt->hdr = pkt_ptr->hdr;
+	if (pkt_ptr->hdr.payload_len) {
+		ret = smux_alloc_pkt_payload(send_pkt);
+		if (ret) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		memcpy(send_pkt->payload, pkt_ptr->payload,
+				pkt_ptr->hdr.payload_len);
+	}
+
+	/* queue duplicate as pseudo-RX data */
+	spin_lock_irqsave(&hw_fn_lock, flags);
+	i = kfifo_avail(&smux_loop_pkt_fifo);
+	if (i < sizeof(struct smux_pkt_t *)) {
+		pr_err("%s: no space in fifo\n", __func__);
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+	i = kfifo_in(&smux_loop_pkt_fifo,
+			&send_pkt,
+			sizeof(struct smux_pkt_t *));
+	if (i < 0) {
+		pr_err("%s: fifo error\n", __func__);
+		ret = -ENOMEM;
+		goto unlock;
+	}
+	queue_work(smux_loopback_wq, &smux_loopback_work);
+	ret = 0;
+
+unlock:
+	spin_unlock_irqrestore(&hw_fn_lock, flags);
+out:
+	return ret;
+}
+
+/**
+ * Receive loopback byte processor.
+ *
+ * @pkt  Incoming packet
+ */
+static void smux_loopback_rx_byte(struct smux_pkt_t *pkt)
+{
+	static int simulated_retry_cnt;
+	const char ack = SMUX_WAKEUP_ACK;
+
+	switch (pkt->hdr.flags) {
+	case SMUX_WAKEUP_REQ:
+		/* reply with ACK after appropriate delays */
+		++simulated_retry_cnt;
+		if (simulated_retry_cnt >= smux_simulate_wakeup_delay) {
+			pr_err("%s: completed %d of %d\n",
+				__func__, simulated_retry_cnt,
+				smux_simulate_wakeup_delay);
+			pr_err("%s: simulated wakeup\n", __func__);
+			simulated_retry_cnt = 0;
+			smux_rx_state_machine(&ack, 1, 0);
+		} else {
+			/* force retry */
+			pr_err("%s: dropping wakeup request %d of %d\n",
+					__func__, simulated_retry_cnt,
+					smux_simulate_wakeup_delay);
+		}
+		break;
+	case SMUX_WAKEUP_ACK:
+		/* this shouldn't happen since we don't send requests */
+		pr_err("%s: wakeup ACK unexpected\n", __func__);
+		break;
+
+	default:
+		/* invalid character */
+		pr_err("%s: invalid character 0x%x\n",
+				__func__, (unsigned)pkt->hdr.flags);
+		break;
+	}
+}
+
+/**
+ * Simulated remote hardware used for local loopback testing.
+ *
+ * @work Not used
+ */
+static void smux_loopback_rx_worker(struct work_struct *work)
+{
+	struct smux_pkt_t *pkt;
+	struct smux_pkt_t reply_pkt;
+	char *data;
+	int len;
+	int lcid;
+	int i;
+	unsigned long flags;
+
+	data = kzalloc(SMUX_MAX_PKT_SIZE, GFP_ATOMIC);
+
+	spin_lock_irqsave(&hw_fn_lock, flags);
+	while (kfifo_len(&smux_loop_pkt_fifo) >= sizeof(struct smux_pkt_t *)) {
+		i = kfifo_out(&smux_loop_pkt_fifo, &pkt,
+					sizeof(struct smux_pkt_t *));
+		spin_unlock_irqrestore(&hw_fn_lock, flags);
+
+		if (pkt->hdr.magic != SMUX_MAGIC) {
+			pr_err("%s: invalid magic %x\n", __func__,
+					pkt->hdr.magic);
+			return;
+		}
+
+		lcid = pkt->hdr.lcid;
+		if (smux_assert_lch_id(lcid)) {
+			pr_err("%s: invalid channel id %d\n", __func__, lcid);
+			return;
+		}
+
+		switch (pkt->hdr.cmd) {
+		case SMUX_CMD_OPEN_LCH:
+			if (pkt->hdr.flags & SMUX_CMD_OPEN_ACK)
+				break;
+
+			/* Reply with Open ACK */
+			smux_init_pkt(&reply_pkt);
+			reply_pkt.hdr.lcid = lcid;
+			reply_pkt.hdr.cmd = SMUX_CMD_OPEN_LCH;
+			reply_pkt.hdr.flags = SMUX_CMD_OPEN_ACK
+				| SMUX_CMD_OPEN_POWER_COLLAPSE;
+			reply_pkt.hdr.payload_len = 0;
+			reply_pkt.hdr.pad_len = 0;
+			smux_serialize(&reply_pkt, data, &len);
+			smux_rx_state_machine(data, len, 0);
+
+			/* Send Remote Open */
+			smux_init_pkt(&reply_pkt);
+			reply_pkt.hdr.lcid = lcid;
+			reply_pkt.hdr.cmd = SMUX_CMD_OPEN_LCH;
+			reply_pkt.hdr.flags = SMUX_CMD_OPEN_POWER_COLLAPSE;
+			reply_pkt.hdr.payload_len = 0;
+			reply_pkt.hdr.pad_len = 0;
+			smux_serialize(&reply_pkt, data, &len);
+			smux_rx_state_machine(data, len, 0);
+			break;
+
+		case SMUX_CMD_CLOSE_LCH:
+			if (pkt->hdr.flags == SMUX_CMD_CLOSE_ACK)
+				break;
+
+			/* Reply with Close ACK */
+			smux_init_pkt(&reply_pkt);
+			reply_pkt.hdr.lcid = lcid;
+			reply_pkt.hdr.cmd = SMUX_CMD_CLOSE_LCH;
+			reply_pkt.hdr.flags = SMUX_CMD_CLOSE_ACK;
+			reply_pkt.hdr.payload_len = 0;
+			reply_pkt.hdr.pad_len = 0;
+			smux_serialize(&reply_pkt, data, &len);
+			smux_rx_state_machine(data, len, 0);
+
+			/* Send Remote Close */
+			smux_init_pkt(&reply_pkt);
+			reply_pkt.hdr.lcid = lcid;
+			reply_pkt.hdr.cmd = SMUX_CMD_CLOSE_LCH;
+			reply_pkt.hdr.flags = 0;
+			reply_pkt.hdr.payload_len = 0;
+			reply_pkt.hdr.pad_len = 0;
+			smux_serialize(&reply_pkt, data, &len);
+			smux_rx_state_machine(data, len, 0);
+			break;
+
+		case SMUX_CMD_DATA:
+			/* Echo back received data */
+			smux_init_pkt(&reply_pkt);
+			reply_pkt.hdr.lcid = lcid;
+			reply_pkt.hdr.cmd = SMUX_CMD_DATA;
+			reply_pkt.hdr.flags = 0;
+			reply_pkt.hdr.payload_len = pkt->hdr.payload_len;
+			reply_pkt.payload = pkt->payload;
+			reply_pkt.hdr.pad_len = pkt->hdr.pad_len;
+			smux_serialize(&reply_pkt, data, &len);
+			smux_rx_state_machine(data, len, 0);
+			break;
+
+		case SMUX_CMD_STATUS:
+			/* Echo back received status */
+			smux_init_pkt(&reply_pkt);
+			reply_pkt.hdr.lcid = lcid;
+			reply_pkt.hdr.cmd = SMUX_CMD_STATUS;
+			reply_pkt.hdr.flags = pkt->hdr.flags;
+			reply_pkt.hdr.payload_len = 0;
+			reply_pkt.payload = NULL;
+			reply_pkt.hdr.pad_len = pkt->hdr.pad_len;
+			smux_serialize(&reply_pkt, data, &len);
+			smux_rx_state_machine(data, len, 0);
+			break;
+
+		case SMUX_CMD_PWR_CTL:
+			/* reply with ack */
+			smux_init_pkt(&reply_pkt);
+			reply_pkt.hdr.lcid = lcid;
+			reply_pkt.hdr.cmd = SMUX_CMD_PWR_CTL;
+			reply_pkt.hdr.flags = SMUX_CMD_PWR_CTL_SLEEP_REQ
+				| SMUX_CMD_PWR_CTL_ACK;
+			reply_pkt.hdr.payload_len = 0;
+			reply_pkt.payload = NULL;
+			reply_pkt.hdr.pad_len = pkt->hdr.pad_len;
+			smux_serialize(&reply_pkt, data, &len);
+			smux_rx_state_machine(data, len, 0);
+			break;
+
+		case SMUX_CMD_BYTE:
+			smux_loopback_rx_byte(pkt);
+			break;
+
+		default:
+			pr_err("%s: unknown command %d\n",
+					__func__, pkt->hdr.cmd);
+			break;
+		};
+
+		smux_free_pkt(pkt);
+		spin_lock_irqsave(&hw_fn_lock, flags);
+	}
+	spin_unlock_irqrestore(&hw_fn_lock, flags);
+	kfree(data);
+}
diff --git a/drivers/tty/smux_loopback.h b/drivers/tty/smux_loopback.h
new file mode 100644
index 0000000..85c6c23
--- /dev/null
+++ b/drivers/tty/smux_loopback.h
@@ -0,0 +1,39 @@
+/* drivers/tty/smux_loopback.h
+ *
+ * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#ifndef SMUX_LOOPBACK_H
+#define SMUX_LOOPBACK_H
+
+#include "smux_private.h"
+
+#ifdef CONFIG_N_SMUX_LOOPBACK
+
+int smux_loopback_init(void);
+int smux_tx_loopback(struct smux_pkt_t *pkt_ptr);
+
+#else
+static inline int smux_loopback_init(void)
+{
+	return 0;
+}
+
+static inline int smux_tx_loopback(struct smux_pkt_t *pkt_ptr)
+{
+	return -ENODEV;
+}
+
+
+#endif /* CONFIG_N_SMUX_LOOPBACK */
+#endif /* SMUX_LOOPBACK_H */
+
diff --git a/drivers/tty/smux_private.h b/drivers/tty/smux_private.h
new file mode 100644
index 0000000..5ce8fb8
--- /dev/null
+++ b/drivers/tty/smux_private.h
@@ -0,0 +1,115 @@
+/* drivers/tty/smux_private.h
+ *
+ * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#ifndef SMUX_PRIVATE_H
+#define SMUX_PRIVATE_H
+
+#define SMUX_MAX_PKT_SIZE   8192
+
+/* SMUX Protocol Characters */
+#define SMUX_MAGIC          0x33FC
+#define SMUX_MAGIC_WORD1    0xFC
+#define SMUX_MAGIC_WORD2    0x33
+#define SMUX_WAKEUP_REQ     0xFD
+#define SMUX_WAKEUP_ACK     0xFE
+
+/* Unit testing characters */
+#define SMUX_UT_ECHO_REQ    0xF0
+#define SMUX_UT_ECHO_ACK_OK 0xF1
+#define SMUX_UT_ECHO_ACK_FAIL 0xF2
+
+struct tty_struct;
+
+/* Packet header. */
+struct smux_hdr_t {
+	uint16_t magic;
+	uint8_t flags;
+	uint8_t cmd;
+	uint8_t pad_len;
+	uint8_t lcid;
+	uint16_t payload_len;
+};
+
+/* Internal packet structure. */
+struct smux_pkt_t {
+	struct smux_hdr_t hdr;
+	int allocated;
+	unsigned char *payload;
+	int free_payload;
+	struct list_head list;
+	void *priv;
+};
+
+/* SMUX Packet Commands */
+enum {
+	SMUX_CMD_DATA = 0x0,
+	SMUX_CMD_OPEN_LCH = 0x1,
+	SMUX_CMD_CLOSE_LCH = 0x2,
+	SMUX_CMD_STATUS = 0x3,
+	SMUX_CMD_PWR_CTL = 0x4,
+
+	SMUX_CMD_BYTE, /* for internal usage */
+	SMUX_NUM_COMMANDS
+};
+
+/* Open command flags */
+enum {
+	SMUX_CMD_OPEN_ACK = 1 << 0,
+	SMUX_CMD_OPEN_POWER_COLLAPSE = 1 << 1,
+	SMUX_CMD_OPEN_REMOTE_LOOPBACK = 1 << 2,
+};
+
+/* Close command flags */
+enum {
+	SMUX_CMD_CLOSE_ACK = 1 << 0,
+};
+
+/* Power command flags */
+enum {
+	SMUX_CMD_PWR_CTL_ACK =  1 << 0,
+	SMUX_CMD_PWR_CTL_SLEEP_REQ =  1 << 1,
+};
+
+/* Local logical channel states */
+enum {
+	SMUX_LCH_LOCAL_CLOSED,
+	SMUX_LCH_LOCAL_OPENING,
+	SMUX_LCH_LOCAL_OPENED,
+	SMUX_LCH_LOCAL_CLOSING,
+};
+
+/* Remote logical channel states */
+enum {
+	SMUX_LCH_REMOTE_CLOSED,
+	SMUX_LCH_REMOTE_OPENED,
+};
+
+
+int smux_assert_lch_id(uint32_t lcid);
+void smux_init_pkt(struct smux_pkt_t *pkt);
+struct smux_pkt_t *smux_alloc_pkt(void);
+int smux_alloc_pkt_payload(struct smux_pkt_t *pkt);
+void smux_free_pkt(struct smux_pkt_t *pkt);
+int smux_serialize(struct smux_pkt_t *pkt, char *out,
+					unsigned int *out_len);
+
+void smux_rx_state_machine(const unsigned char *data, int len, int flag);
+void smuxld_receive_buf(struct tty_struct *tty, const unsigned char *cp,
+			   char *fp, int count);
+
+/* testing parameters */
+extern int smux_byte_loopback;
+extern int smux_simulate_wakeup_delay;
+
+#endif /* SMUX_PRIVATE_H */
diff --git a/drivers/tty/smux_test.c b/drivers/tty/smux_test.c
new file mode 100644
index 0000000..242c66e
--- /dev/null
+++ b/drivers/tty/smux_test.c
@@ -0,0 +1,1222 @@
+/* drivers/tty/smux_test.c
+ *
+ * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/list.h>
+#include <linux/ctype.h>
+#include <linux/jiffies.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/completion.h>
+#include <linux/termios.h>
+#include <linux/smux.h>
+#include "smux_private.h"
+
+#define DEBUG_BUFMAX 4096
+
+/**
+ * Unit test assertion for logging test cases.
+ *
+ * @a lval
+ * @b rval
+ * @cmp comparison operator
+ *
+ * Assertion fails if (@a cmp @b) is not true which then
+ * logs the function and line number where the error occurred
+ * along with the values of @a and @b.
+ *
+ * Assumes that the following local variables exist:
+ * @buf - buffer to write failure message to
+ * @i - number of bytes written to buffer
+ * @max - maximum size of the buffer
+ * @failed - set to true if test fails
+ */
+#define UT_ASSERT_INT(a, cmp, b) \
+	if (!((a)cmp(b))) { \
+		i += scnprintf(buf + i, max - i, \
+			"%s:%d Fail: " #a "(%d) " #cmp " " #b "(%d)\n", \
+				__func__, __LINE__, \
+				a, b); \
+		failed = 1; \
+		break; \
+	} \
+	do {} while (0)
+
+#define UT_ASSERT_PTR(a, cmp, b) \
+	if (!((a)cmp(b))) { \
+		i += scnprintf(buf + i, max - i, \
+			"%s:%d Fail: " #a "(%p) " #cmp " " #b "(%p)\n", \
+				__func__, __LINE__, \
+				a, b); \
+		failed = 1; \
+		break; \
+	} \
+	do {} while (0)
+
+#define UT_ASSERT_UINT(a, cmp, b) \
+	if (!((a)cmp(b))) { \
+		i += scnprintf(buf + i, max - i, \
+			"%s:%d Fail: " #a "(%u) " #cmp " " #b "(%u)\n", \
+				__func__, __LINE__, \
+				a, b); \
+		failed = 1; \
+		break; \
+	} \
+	do {} while (0)
+
+static unsigned char test_array[] = {1, 1, 2, 3, 5, 8, 13, 21, 34, 55,
+					89, 144, 233};
+
+/* Used for mapping local to remote TIOCM signals */
+struct tiocm_test_vector {
+	uint32_t input;
+	uint32_t set_old;
+	uint32_t set_new;
+	uint32_t clr_old;
+};
+
+/**
+ * Allocates a new buffer for SMUX for every call.
+ */
+int get_rx_buffer(void *priv, void **pkt_priv, void **buffer, int size)
+{
+	void *rx_buf;
+
+	rx_buf = kmalloc(size, GFP_ATOMIC);
+	*pkt_priv = (void *)0x1234;
+	*buffer = rx_buf;
+
+	return 0;
+}
+
+/* Test vector for packet tests. */
+struct test_vector {
+	const char *data;
+	const unsigned len;
+};
+
+/* Mock object metadata for SMUX_READ_DONE event */
+struct mock_read_event {
+	struct list_head list;
+	struct smux_meta_read meta;
+};
+
+/* Mock object metadata for SMUX_WRITE_DONE event */
+struct mock_write_event {
+	struct list_head list;
+	struct smux_meta_write meta;
+};
+
+/* Mock object for all SMUX callback events */
+struct smux_mock_callback {
+	int cb_count;
+	struct completion cb_completion;
+	spinlock_t lock;
+
+	/* status changes */
+	int event_connected;
+	int event_disconnected;
+	int event_disconnected_ssr;
+	int event_low_wm;
+	int event_high_wm;
+
+	/* TIOCM changes */
+	int event_tiocm;
+	struct smux_meta_tiocm tiocm_meta;
+
+	/* read event data */
+	int event_read_done;
+	int event_read_failed;
+	struct list_head read_events;
+
+	/* write event data */
+	int event_write_done;
+	int event_write_failed;
+	struct list_head write_events;
+};
+
+/**
+ * Initialize mock callback data. Only call once.
+ *
+ * @cb  Mock callback data
+ */
+void mock_cb_data_init(struct smux_mock_callback *cb)
+{
+	init_completion(&cb->cb_completion);
+	spin_lock_init(&cb->lock);
+	INIT_LIST_HEAD(&cb->read_events);
+	INIT_LIST_HEAD(&cb->write_events);
+}
+
+/**
+ * Reset mock callback data to default values.
+ *
+ * @cb  Mock callback data
+ *
+ * All packets are freed and counters reset to zero.
+ */
+void mock_cb_data_reset(struct smux_mock_callback *cb)
+{
+	cb->cb_count = 0;
+	INIT_COMPLETION(cb->cb_completion);
+	cb->event_connected = 0;
+	cb->event_disconnected = 0;
+	cb->event_disconnected_ssr = 0;
+	cb->event_low_wm = 0;
+	cb->event_high_wm = 0;
+	cb->event_tiocm = 0;
+	cb->tiocm_meta.tiocm_old = 0;
+	cb->tiocm_meta.tiocm_new = 0;
+
+	cb->event_read_done = 0;
+	cb->event_read_failed = 0;
+	while (!list_empty(&cb->read_events)) {
+		struct mock_read_event *meta;
+		meta = list_first_entry(&cb->read_events,
+				struct mock_read_event,
+				list);
+		kfree(meta->meta.buffer);
+		list_del(&meta->list);
+		kfree(meta);
+	}
+
+	cb->event_write_done = 0;
+	cb->event_write_failed = 0;
+	while (!list_empty(&cb->write_events)) {
+		struct mock_write_event *meta;
+		meta = list_first_entry(&cb->write_events,
+				struct mock_write_event,
+				list);
+		list_del(&meta->list);
+		kfree(meta);
+	}
+}
+
+/**
+ * Dump the values of the mock callback data for debug purposes.
+ *
+ * @cb  Mock callback data
+ * @buf Print buffer
+ * @max Maximum number of characters to print
+ *
+ * @returns Number of characters added to buffer
+ */
+static int mock_cb_data_print(const struct smux_mock_callback *cb,
+		char *buf, int max)
+{
+	int i = 0;
+
+	i += scnprintf(buf + i, max - i,
+		"\tcb_count=%d\n"
+		"\tcb_completion.done=%d\n"
+		"\tevent_connected=%d\n"
+		"\tevent_disconnected=%d\n"
+		"\tevent_disconnected_ssr=%d\n"
+		"\tevent_low_wm=%d\n"
+		"\tevent_high_wm=%d\n"
+		"\tevent_tiocm=%d\n"
+		"\tevent_read_done=%d\n"
+		"\tevent_read_failed=%d\n"
+		"\tread_events=%d\n"
+		"\tevent_write_done=%d\n"
+		"\tevent_write_failed=%d\n"
+		"\twrite_events=%d\n",
+		cb->cb_count,
+		cb->cb_completion.done,
+		cb->event_connected,
+		cb->event_disconnected,
+		cb->event_disconnected_ssr,
+		cb->event_low_wm,
+		cb->event_high_wm,
+		cb->event_tiocm,
+		cb->event_read_done,
+		cb->event_read_failed,
+		!list_empty(&cb->read_events),
+		cb->event_write_done,
+		cb->event_write_failed,
+		list_empty(&cb->write_events)
+		);
+
+	return i;
+}
+
+/**
+ * Mock object event callback.  Used to logs events for analysis in the unit
+ * tests.
+ */
+void smux_mock_cb(void *priv, int event, const void *metadata)
+{
+	struct smux_mock_callback *cb_data_ptr;
+	struct mock_write_event *write_event_meta;
+	struct mock_read_event *read_event_meta;
+	unsigned long flags;
+
+	cb_data_ptr = (struct smux_mock_callback *)priv;
+	if (cb_data_ptr == NULL) {
+		pr_err("%s: invalid private data\n", __func__);
+		return;
+	}
+
+	spin_lock_irqsave(&cb_data_ptr->lock, flags);
+	switch (event) {
+	case SMUX_CONNECTED:
+		++cb_data_ptr->event_connected;
+		break;
+
+	case SMUX_DISCONNECTED:
+		++cb_data_ptr->event_disconnected;
+		cb_data_ptr->event_disconnected_ssr =
+			((struct smux_meta_disconnected *)metadata)->is_ssr;
+		break;
+
+	case SMUX_READ_DONE:
+		++cb_data_ptr->event_read_done;
+		read_event_meta = kmalloc(sizeof(struct mock_read_event),
+						GFP_ATOMIC);
+		if (read_event_meta) {
+			read_event_meta->meta =
+				*(struct smux_meta_read *)metadata;
+			list_add_tail(&read_event_meta->list,
+						&cb_data_ptr->read_events);
+		}
+		break;
+
+	case SMUX_READ_FAIL:
+		++cb_data_ptr->event_read_failed;
+		read_event_meta = kmalloc(sizeof(struct mock_read_event),
+						GFP_ATOMIC);
+		if (read_event_meta) {
+			read_event_meta->meta =
+					*(struct smux_meta_read *)metadata;
+			list_add_tail(&read_event_meta->list,
+					&cb_data_ptr->read_events);
+		}
+		break;
+
+	case SMUX_WRITE_DONE:
+		++cb_data_ptr->event_write_done;
+		write_event_meta = kmalloc(sizeof(struct mock_write_event),
+						GFP_ATOMIC);
+		if (write_event_meta) {
+			write_event_meta->meta =
+					*(struct smux_meta_write *)metadata;
+			list_add_tail(&write_event_meta->list,
+					&cb_data_ptr->write_events);
+		}
+		break;
+
+	case SMUX_WRITE_FAIL:
+		++cb_data_ptr->event_write_failed;
+		write_event_meta = kmalloc(sizeof(struct mock_write_event),
+						GFP_ATOMIC);
+		if (write_event_meta) {
+			write_event_meta->meta =
+				*(struct smux_meta_write *)metadata;
+			list_add_tail(&write_event_meta->list,
+					&cb_data_ptr->write_events);
+		}
+		break;
+
+	case SMUX_LOW_WM_HIT:
+		++cb_data_ptr->event_low_wm;
+		break;
+
+	case SMUX_HIGH_WM_HIT:
+		++cb_data_ptr->event_high_wm;
+		break;
+
+	case SMUX_TIOCM_UPDATE:
+		++cb_data_ptr->event_tiocm;
+		cb_data_ptr->tiocm_meta = *(struct smux_meta_tiocm *)metadata;
+		break;
+
+	default:
+		pr_err("%s: unknown event %d\n", __func__, event);
+	};
+
+	++cb_data_ptr->cb_count;
+	complete(&cb_data_ptr->cb_completion);
+	spin_unlock_irqrestore(&cb_data_ptr->lock, flags);
+}
+
+/**
+ * Test Read/write usage.
+ *
+ * @buf       Output buffer for failure/status messages
+ * @max       Size of @buf
+ * @vectors   Test vector data (must end with NULL item)
+ * @name      Name of the test case for failure messages
+ *
+ * Perform a sanity test consisting of opening a port, writing test packet(s),
+ * reading the response(s), and closing the port.
+ *
+ * The port should already be configured to use either local or remote
+ * loopback.
+ */
+static int smux_ut_basic_core(char *buf, int max,
+	const struct test_vector *vectors,
+	const char *name)
+{
+	int i = 0;
+	int failed = 0;
+	static struct smux_mock_callback cb_data;
+	static int cb_initialized;
+	int ret;
+
+	if (!cb_initialized)
+		mock_cb_data_init(&cb_data);
+
+	mock_cb_data_reset(&cb_data);
+	while (!failed) {
+		struct mock_write_event *write_event;
+		struct mock_read_event *read_event;
+
+		/* open port */
+		ret = msm_smux_open(SMUX_TEST_LCID, &cb_data, smux_mock_cb,
+					get_rx_buffer);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+			(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ), >, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_connected, ==, 1);
+		mock_cb_data_reset(&cb_data);
+
+		/* write, read, and verify the test vector data */
+		for (; vectors->data != NULL; ++vectors) {
+			const char *test_data = vectors->data;
+			const unsigned test_len = vectors->len;
+
+			i += scnprintf(buf + i, max - i,
+					"Writing vector %p len %d\n",
+					test_data, test_len);
+
+			/* write data */
+			msm_smux_write(SMUX_TEST_LCID, (void *)0xCAFEFACE,
+					test_data, test_len);
+			UT_ASSERT_INT(ret, ==, 0);
+			UT_ASSERT_INT(
+					(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ), >, 0);
+
+			/* wait for write and echo'd read to complete */
+			INIT_COMPLETION(cb_data.cb_completion);
+			if (cb_data.cb_count < 2)
+				UT_ASSERT_INT(
+					(int)wait_for_completion_timeout(
+						&cb_data.cb_completion, HZ),
+					>, 0);
+
+			UT_ASSERT_INT(cb_data.cb_count, >=, 1);
+			UT_ASSERT_INT(cb_data.event_write_done, ==, 1);
+			UT_ASSERT_INT(list_empty(&cb_data.write_events), ==, 0);
+
+			write_event = list_first_entry(&cb_data.write_events,
+					struct mock_write_event, list);
+			UT_ASSERT_PTR(write_event->meta.pkt_priv, ==,
+							(void *)0xCAFEFACE);
+			UT_ASSERT_PTR(write_event->meta.buffer, ==,
+							(void *)test_data);
+			UT_ASSERT_INT(write_event->meta.len, ==, test_len);
+
+			/* verify read event */
+			UT_ASSERT_INT(cb_data.event_read_done, ==, 1);
+			UT_ASSERT_INT(list_empty(&cb_data.read_events), ==, 0);
+			read_event = list_first_entry(&cb_data.read_events,
+					struct mock_read_event, list);
+			UT_ASSERT_PTR(read_event->meta.pkt_priv, ==,
+							(void *)0x1234);
+			UT_ASSERT_PTR(read_event->meta.buffer, !=, NULL);
+
+			if (read_event->meta.len != test_len ||
+				memcmp(read_event->meta.buffer,
+						test_data, test_len)) {
+				/* data mismatch */
+				char linebuff[80];
+
+				hex_dump_to_buffer(test_data, test_len,
+					16, 1, linebuff, sizeof(linebuff), 1);
+				i += scnprintf(buf + i, max - i,
+						"Expected:\n%s\n\n", linebuff);
+
+				hex_dump_to_buffer(read_event->meta.buffer,
+					read_event->meta.len,
+					16, 1, linebuff, sizeof(linebuff), 1);
+				i += scnprintf(buf + i, max - i,
+						"Actual:\n%s\n", linebuff);
+				failed = 1;
+				break;
+			}
+			mock_cb_data_reset(&cb_data);
+		}
+
+		/* close port */
+		ret = msm_smux_close(SMUX_TEST_LCID);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+			(int)wait_for_completion_timeout(
+				&cb_data.cb_completion, HZ),
+			>, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected_ssr, ==, 0);
+		break;
+	}
+
+	if (!failed) {
+		i += scnprintf(buf + i, max - i, "\tOK\n");
+	} else {
+		pr_err("%s: Failed\n", name);
+		i += scnprintf(buf + i, max - i, "\tFailed\n");
+		i += mock_cb_data_print(&cb_data, buf + i, max - i);
+		msm_smux_close(SMUX_TEST_LCID);
+	}
+
+	mock_cb_data_reset(&cb_data);
+	return i;
+}
+
+/**
+ * Verify Basic Local Loopback Support
+ *
+ * Perform a sanity test consisting of opening a port in local loopback
+ * mode and writing a packet and reading the echo'd packet back.
+ */
+static int smux_ut_basic(char *buf, int max)
+{
+	const struct test_vector test_data[] = {
+		{"hello\0world\n", sizeof("hello\0world\n")},
+		{0, 0},
+	};
+	int i = 0;
+	int failed = 0;
+	int ret;
+
+	i += scnprintf(buf + i, max - i, "Running %s\n", __func__);
+	while (!failed) {
+		/* enable loopback mode */
+		ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+				SMUX_CH_OPTION_LOCAL_LOOPBACK, 0);
+		UT_ASSERT_INT(ret, ==, 0);
+
+		i += smux_ut_basic_core(buf + i, max - i, test_data, __func__);
+		break;
+	}
+
+	if (failed) {
+		pr_err("%s: Failed\n", __func__);
+		i += scnprintf(buf + i, max - i, "\tFailed\n");
+	}
+	return i;
+}
+
+/**
+ * Verify Basic Remote Loopback Support
+ *
+ * Perform a sanity test consisting of opening a port in remote loopback
+ * mode and writing a packet and reading the echo'd packet back.
+ */
+static int smux_ut_remote_basic(char *buf, int max)
+{
+	const struct test_vector test_data[] = {
+		{"hello\0world\n", sizeof("hello\0world\n")},
+		{0, 0},
+	};
+	int i = 0;
+	int failed = 0;
+	int ret;
+
+	i += scnprintf(buf + i, max - i, "Running %s\n", __func__);
+	while (!failed) {
+		/* enable remote mode */
+		ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+				SMUX_CH_OPTION_REMOTE_LOOPBACK, 0);
+		UT_ASSERT_INT(ret, ==, 0);
+
+		i += smux_ut_basic_core(buf + i, max - i, test_data, __func__);
+		break;
+	}
+
+	if (failed) {
+		pr_err("%s: Failed\n", __func__);
+		i += scnprintf(buf + i, max - i, "\tFailed\n");
+	}
+	return i;
+}
+
+/**
+ * Fill test pattern into provided buffer including an optional
+ * redzone 16 bytes before and 16 bytes after the buffer.
+ *
+ * buf ---------
+ *      redzone
+ *     --------- <- returned pointer
+ *       data
+ *     --------- <- returned pointer + len
+ *      redzone
+ *     ---------
+ *
+ * @buf  Pointer to the buffer of size len or len+32 (redzone)
+ * @len  Length of the *data* buffer (excluding 32-byte redzone)
+ * @redzone If true, adds redzone data
+ *
+ * @returns pointer to buffer (buf + 16 if redzone enabled)
+ */
+uint8_t *test_pattern_fill(char *buf, int len, int redzone)
+{
+	void *ret;
+	uint8_t ch;
+
+	ret = buf;
+	if (redzone) {
+		memset((char *)buf, 0xAB, 16);
+		memset((char *)buf + len, 0xBA, 16);
+		ret += 16;
+	}
+
+	/* fill with test pattern */
+	for (ch = 0; len > 0; --len, ++ch)
+		*buf++ = (char)ch;
+
+	return ret;
+}
+
+/**
+ * Verify test pattern generated by test_pattern_fill.
+ *
+ * @buf_ptr    Pointer to buffer pointer
+ * @len        Length of the *data* buffer (excluding 32-byte redzone)
+ * @redzone    If true, verifies redzone and adjusts *buf_ptr
+ * @errmsg     Buffer for error message
+ * @errmsg_max Size of error message buffer
+ *
+ * @returns    0 for success; length of error message otherwise
+ */
+unsigned test_pattern_verify(char **buf_ptr, int len, int redzone,
+					char *errmsg, int errmsg_max)
+{
+	int n;
+	int i = 0;
+	char linebuff[80];
+
+	if (redzone) {
+		*buf_ptr -= 16;
+
+		/* verify prefix redzone */
+		for (n = 0; n < 16; ++n) {
+			if (*buf_ptr[n] != 0xAB) {
+				hex_dump_to_buffer(*buf_ptr, 16,
+					16, 1, linebuff, sizeof(linebuff), 1);
+				i += scnprintf(errmsg + i, errmsg_max - i,
+					"Redzone violation: %s\n", linebuff);
+				break;
+			}
+		}
+
+		/* verify postfix redzone */
+		for (n = 0; n < 16; ++n) {
+			if (*buf_ptr[len + n] != 0xBA) {
+				hex_dump_to_buffer(&(*buf_ptr)[len], 16,
+					16, 1, linebuff, sizeof(linebuff), 1);
+				i += scnprintf(errmsg + i, errmsg_max - i,
+					"Redzone violation: %s\n", linebuff);
+				break;
+			}
+		}
+	}
+	return i;
+}
+
+/**
+ * Write a multiple packets in ascending size and verify packet is received
+ * correctly.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ * @name Name of the test for error reporting
+ *
+ * @returns Number of bytes written to @buf
+ *
+ * Requires that the port already be opened and loopback mode is
+ * configured correctly (if required).
+ */
+static int smux_ut_loopback_big_pkt(char *buf, int max, const char *name)
+{
+	struct test_vector test_data[] = {
+		{0, 64},
+		{0, 128},
+		{0, 256},
+		{0, 512},
+		{0, 1024},
+		{0, 2048},
+		{0, 4096},
+		{0, 0},
+	};
+	int i = 0;
+	int failed = 0;
+	struct test_vector *tv;
+
+	/* generate test data */
+	for (tv = test_data; tv->len > 0; ++tv) {
+		tv->data = kmalloc(tv->len + 32, GFP_KERNEL);
+		pr_err("%s: allocating %p len %d\n",
+				__func__, tv->data, tv->len);
+		if (!tv->data) {
+			i += scnprintf(buf + i, max - i,
+					"%s: Unable to allocate %d bytes\n",
+					__func__, tv->len);
+			failed = 1;
+			goto out;
+		}
+		test_pattern_fill((uint8_t *)tv->data, tv->len, 1);
+	}
+
+	/* run test */
+	i += scnprintf(buf + i, max - i, "Running %s\n", name);
+	while (!failed) {
+		i += smux_ut_basic_core(buf + i, max - i, test_data, name);
+		break;
+	}
+
+out:
+	if (failed) {
+		pr_err("%s: Failed\n", name);
+		i += scnprintf(buf + i, max - i, "\tFailed\n");
+	}
+
+	for (tv = test_data; tv->len > 0; ++tv) {
+		if (!tv->data) {
+			i += test_pattern_verify((char **)&tv->data,
+						tv->len, 1, buf + i, max - i);
+			pr_err("%s: freeing %p len %d\n", __func__,
+							tv->data, tv->len);
+			kfree(tv->data);
+		}
+	}
+
+	return i;
+}
+
+/**
+ * Verify Large-packet Local Loopback Support.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ *
+ * @returns Number of bytes written to @buf
+ *
+ * Open port in local loopback mode and write a multiple packets in ascending
+ * size and verify packet is received correctly.
+ */
+static int smux_ut_local_big_pkt(char *buf, int max)
+{
+	int i = 0;
+	int ret;
+
+	ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+			SMUX_CH_OPTION_LOCAL_LOOPBACK, 0);
+
+	if (ret == 0) {
+		smux_byte_loopback = SMUX_TEST_LCID;
+		i += smux_ut_loopback_big_pkt(buf, max, __func__);
+		smux_byte_loopback = 0;
+	} else {
+		i += scnprintf(buf + i, max - i,
+				"%s: Unable to set loopback mode\n",
+				__func__);
+	}
+
+	return i;
+}
+
+/**
+ * Verify Large-packet Remote Loopback Support.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ *
+ * @returns Number of bytes written to @buf
+ *
+ * Open port in remote loopback mode and write a multiple packets in ascending
+ * size and verify packet is received correctly.
+ */
+static int smux_ut_remote_big_pkt(char *buf, int max)
+{
+	int i = 0;
+	int ret;
+
+	ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+			SMUX_CH_OPTION_REMOTE_LOOPBACK, 0);
+	if (ret == 0) {
+		i += smux_ut_loopback_big_pkt(buf, max, __func__);
+	} else {
+		i += scnprintf(buf + i, max - i,
+				"%s: Unable to set loopback mode\n",
+				__func__);
+	}
+
+	return i;
+}
+
+/**
+ * Verify set and get operations for each TIOCM bit.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ * @name Name of the test for error reporting
+ *
+ * @returns Number of bytes written to @buf
+ */
+static int smux_ut_tiocm(char *buf, int max, const char *name)
+{
+	static struct smux_mock_callback cb_data;
+	static int cb_initialized;
+	static const struct tiocm_test_vector tiocm_vectors[] = {
+		/* bit to set, set old, set new, clear old */
+		{TIOCM_DTR, TIOCM_DTR, TIOCM_DTR | TIOCM_DSR, TIOCM_DSR},
+		{TIOCM_RTS, TIOCM_RTS, TIOCM_RTS | TIOCM_CTS, TIOCM_CTS},
+		{TIOCM_RI, 0x0, TIOCM_RI, TIOCM_RI},
+		{TIOCM_CD, 0x0, TIOCM_CD, TIOCM_CD},
+	};
+	int i = 0;
+	int failed = 0;
+	int n;
+	int ret;
+
+	i += scnprintf(buf + i, max - i, "Running %s\n", name);
+
+	if (!cb_initialized)
+		mock_cb_data_init(&cb_data);
+
+	mock_cb_data_reset(&cb_data);
+	while (!failed) {
+		/* open port */
+		ret = msm_smux_open(SMUX_TEST_LCID, &cb_data, smux_mock_cb,
+								get_rx_buffer);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+				(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ), >, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_connected, ==, 1);
+		mock_cb_data_reset(&cb_data);
+
+		/* set and clear each TIOCM bit */
+		for (n = 0; n < ARRAY_SIZE(tiocm_vectors) && !failed; ++n) {
+			/* set signal and verify */
+			ret = msm_smux_tiocm_set(SMUX_TEST_LCID,
+						tiocm_vectors[n].input, 0x0);
+			UT_ASSERT_INT(ret, ==, 0);
+			UT_ASSERT_INT(
+				(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ), >, 0);
+			UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+			UT_ASSERT_INT(cb_data.event_tiocm, ==, 1);
+			UT_ASSERT_INT(cb_data.tiocm_meta.tiocm_old, ==,
+						tiocm_vectors[n].set_old);
+			UT_ASSERT_INT(cb_data.tiocm_meta.tiocm_new, ==,
+						tiocm_vectors[n].set_new);
+			mock_cb_data_reset(&cb_data);
+
+			/* clear signal and verify */
+			ret = msm_smux_tiocm_set(SMUX_TEST_LCID, 0x0,
+						tiocm_vectors[n].input);
+			UT_ASSERT_INT(ret, ==, 0);
+			UT_ASSERT_INT(
+				(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ),
+				>, 0);
+			UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+			UT_ASSERT_INT(cb_data.event_tiocm, ==, 1);
+			UT_ASSERT_INT(cb_data.tiocm_meta.tiocm_old, ==,
+						tiocm_vectors[n].clr_old);
+			UT_ASSERT_INT(cb_data.tiocm_meta.tiocm_new, ==, 0x0);
+			mock_cb_data_reset(&cb_data);
+		}
+		if (failed)
+			break;
+
+		/* close port */
+		ret = msm_smux_close(SMUX_TEST_LCID);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+			(int)wait_for_completion_timeout(
+				&cb_data.cb_completion, HZ),
+			>, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected_ssr, ==, 0);
+		break;
+	}
+
+	if (!failed) {
+		i += scnprintf(buf + i, max - i, "\tOK\n");
+	} else {
+		pr_err("%s: Failed\n", name);
+		i += scnprintf(buf + i, max - i, "\tFailed\n");
+		i += mock_cb_data_print(&cb_data, buf + i, max - i);
+		msm_smux_close(SMUX_TEST_LCID);
+	}
+
+	mock_cb_data_reset(&cb_data);
+	return i;
+}
+
+/**
+ * Verify TIOCM Status Bits for local loopback.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ *
+ * @returns Number of bytes written to @buf
+ */
+static int smux_ut_local_tiocm(char *buf, int max)
+{
+	int i = 0;
+	int ret;
+
+	ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+			SMUX_CH_OPTION_LOCAL_LOOPBACK, 0);
+
+	if (ret == 0) {
+		smux_byte_loopback = SMUX_TEST_LCID;
+		i += smux_ut_tiocm(buf, max, __func__);
+		smux_byte_loopback = 0;
+	} else {
+		i += scnprintf(buf + i, max - i,
+				"%s: Unable to set loopback mode\n",
+				__func__);
+	}
+
+	return i;
+}
+
+/**
+ * Verify TIOCM Status Bits for remote loopback.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ *
+ * @returns Number of bytes written to @buf
+ */
+static int smux_ut_remote_tiocm(char *buf, int max)
+{
+	int i = 0;
+	int ret;
+
+	ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+			SMUX_CH_OPTION_REMOTE_LOOPBACK, 0);
+	if (ret == 0) {
+		i += smux_ut_tiocm(buf, max, __func__);
+	} else {
+		i += scnprintf(buf + i, max - i,
+				"%s: Unable to set loopback mode\n",
+				__func__);
+	}
+
+	return i;
+}
+
+/**
+ * Verify High/Low Watermark notifications.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ *
+ * @returns Number of bytes written to @buf
+ */
+static int smux_ut_local_wm(char *buf, int max)
+{
+	static struct smux_mock_callback cb_data;
+	static int cb_initialized;
+	int i = 0;
+	int failed = 0;
+	int ret;
+
+	i += scnprintf(buf + i, max - i, "Running %s\n", __func__);
+	pr_err("%s", buf);
+
+	if (!cb_initialized)
+		mock_cb_data_init(&cb_data);
+
+	mock_cb_data_reset(&cb_data);
+	smux_byte_loopback = SMUX_TEST_LCID;
+	while (!failed) {
+		/* open port for loopback with TX disabled */
+		ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+				SMUX_CH_OPTION_LOCAL_LOOPBACK
+				| SMUX_CH_OPTION_REMOTE_TX_STOP,
+				0);
+		UT_ASSERT_INT(ret, ==, 0);
+
+		ret = msm_smux_open(SMUX_TEST_LCID, &cb_data, smux_mock_cb,
+								get_rx_buffer);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+				(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ), >, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_connected, ==, 1);
+		mock_cb_data_reset(&cb_data);
+
+		/* transmit 4 packets and verify high-watermark notification */
+		ret = 0;
+		ret |= msm_smux_write(SMUX_TEST_LCID, (void *)1,
+					test_array, sizeof(test_array));
+		ret |= msm_smux_write(SMUX_TEST_LCID, (void *)2,
+					test_array, sizeof(test_array));
+		ret |= msm_smux_write(SMUX_TEST_LCID, (void *)3,
+					test_array, sizeof(test_array));
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 0);
+		UT_ASSERT_INT(cb_data.event_high_wm, ==, 0);
+
+		ret = msm_smux_write(SMUX_TEST_LCID, (void *)4,
+					test_array, sizeof(test_array));
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+			(int)wait_for_completion_timeout(
+				&cb_data.cb_completion, HZ),
+			>, 0);
+		UT_ASSERT_INT(cb_data.event_high_wm, ==, 1);
+		UT_ASSERT_INT(cb_data.event_low_wm, ==, 0);
+		mock_cb_data_reset(&cb_data);
+
+		/* exceed watermark and verify failure return value */
+		ret = msm_smux_write(SMUX_TEST_LCID, (void *)5,
+					test_array, sizeof(test_array));
+		UT_ASSERT_INT(ret, ==, -EAGAIN);
+
+		/* re-enable TX and verify low-watermark notification */
+		ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+				0, SMUX_CH_OPTION_REMOTE_TX_STOP);
+		UT_ASSERT_INT(ret, ==, 0);
+		while (cb_data.cb_count < 9) {
+			UT_ASSERT_INT(
+				(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ),
+				>, 0);
+			INIT_COMPLETION(cb_data.cb_completion);
+		}
+		if (failed)
+			break;
+
+		UT_ASSERT_INT(cb_data.event_high_wm, ==, 0);
+		UT_ASSERT_INT(cb_data.event_low_wm, ==, 1);
+		UT_ASSERT_INT(cb_data.event_write_done, ==, 4);
+		mock_cb_data_reset(&cb_data);
+
+		/* close port */
+		ret = msm_smux_close(SMUX_TEST_LCID);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+			(int)wait_for_completion_timeout(
+				&cb_data.cb_completion, HZ),
+			>, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected_ssr, ==, 0);
+		break;
+	}
+
+	if (!failed) {
+		i += scnprintf(buf + i, max - i, "\tOK\n");
+	} else {
+		pr_err("%s: Failed\n", __func__);
+		i += scnprintf(buf + i, max - i, "\tFailed\n");
+		i += mock_cb_data_print(&cb_data, buf + i, max - i);
+		msm_smux_close(SMUX_TEST_LCID);
+	}
+	smux_byte_loopback = 0;
+	mock_cb_data_reset(&cb_data);
+	return i;
+}
+
+/**
+ * Verify smuxld_receive_buf regular and error processing.
+ *
+ * @buf  Buffer for status message
+ * @max  Size of buffer
+ *
+ * @returns Number of bytes written to @buf
+ */
+static int smux_ut_local_smuxld_receive_buf(char *buf, int max)
+{
+	static struct smux_mock_callback cb_data;
+	static int cb_initialized;
+	struct mock_read_event *meta;
+	int i = 0;
+	int failed = 0;
+	int ret;
+	char data[] = {SMUX_UT_ECHO_REQ,
+		SMUX_UT_ECHO_REQ, SMUX_UT_ECHO_REQ,
+	};
+	char flags[] = {0x0, 0x1, 0x0,};
+
+
+	i += scnprintf(buf + i, max - i, "Running %s\n", __func__);
+
+	if (!cb_initialized)
+		mock_cb_data_init(&cb_data);
+
+	mock_cb_data_reset(&cb_data);
+	smux_byte_loopback = SMUX_TEST_LCID;
+	while (!failed) {
+		/* open port for loopback */
+		ret = msm_smux_set_ch_option(SMUX_TEST_LCID,
+				SMUX_CH_OPTION_LOCAL_LOOPBACK, 0);
+		UT_ASSERT_INT(ret, ==, 0);
+
+		ret = msm_smux_open(SMUX_TEST_LCID, &cb_data, smux_mock_cb,
+								get_rx_buffer);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+				(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ), >, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_connected, ==, 1);
+		mock_cb_data_reset(&cb_data);
+
+		/*
+		 * Verify RX error processing by sending 3 echo requests:
+		 *     one OK, one fail, and a final OK
+		 *
+		 * The parsing framework should process the requests
+		 * and send us three BYTE command packets with
+		 * ECHO ACK FAIL and ECHO ACK OK characters.
+		 */
+		smuxld_receive_buf(0, data, flags, sizeof(data));
+
+		/* verify response characters */
+		do {
+			UT_ASSERT_INT(
+				(int)wait_for_completion_timeout(
+					&cb_data.cb_completion, HZ), >, 0);
+			INIT_COMPLETION(cb_data.cb_completion);
+		} while (cb_data.cb_count < 3);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 3);
+		UT_ASSERT_INT(cb_data.event_read_done, ==, 3);
+
+		meta = list_first_entry(&cb_data.read_events,
+				struct mock_read_event, list);
+		UT_ASSERT_INT((int)meta->meta.pkt_priv, ==,
+				SMUX_UT_ECHO_ACK_OK);
+		list_del(&meta->list);
+
+		meta = list_first_entry(&cb_data.read_events,
+				struct mock_read_event, list);
+		UT_ASSERT_INT((int)meta->meta.pkt_priv, ==,
+				SMUX_UT_ECHO_ACK_FAIL);
+		list_del(&meta->list);
+
+		meta = list_first_entry(&cb_data.read_events,
+				struct mock_read_event, list);
+		UT_ASSERT_INT((int)meta->meta.pkt_priv, ==,
+				SMUX_UT_ECHO_ACK_OK);
+		list_del(&meta->list);
+		mock_cb_data_reset(&cb_data);
+
+		/* close port */
+		ret = msm_smux_close(SMUX_TEST_LCID);
+		UT_ASSERT_INT(ret, ==, 0);
+		UT_ASSERT_INT(
+			(int)wait_for_completion_timeout(
+				&cb_data.cb_completion, HZ),
+			>, 0);
+		UT_ASSERT_INT(cb_data.cb_count, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected, ==, 1);
+		UT_ASSERT_INT(cb_data.event_disconnected_ssr, ==, 0);
+		break;
+	}
+
+	if (!failed) {
+		i += scnprintf(buf + i, max - i, "\tOK\n");
+	} else {
+		pr_err("%s: Failed\n", __func__);
+		i += scnprintf(buf + i, max - i, "\tFailed\n");
+		i += mock_cb_data_print(&cb_data, buf + i, max - i);
+		msm_smux_close(SMUX_TEST_LCID);
+	}
+	smux_byte_loopback = 0;
+	mock_cb_data_reset(&cb_data);
+	return i;
+}
+
+static char debug_buffer[DEBUG_BUFMAX];
+
+static ssize_t debug_read(struct file *file, char __user *buf,
+			  size_t count, loff_t *ppos)
+{
+	int (*fill)(char *buf, int max) = file->private_data;
+	int bsize;
+
+	if (*ppos != 0)
+		return 0;
+
+	bsize = fill(debug_buffer, DEBUG_BUFMAX);
+	return simple_read_from_buffer(buf, count, ppos, debug_buffer, bsize);
+}
+
+static int debug_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+static const struct file_operations debug_ops = {
+	.read = debug_read,
+	.open = debug_open,
+};
+
+static void debug_create(const char *name, mode_t mode,
+			 struct dentry *dent,
+			 int (*fill)(char *buf, int max))
+{
+	debugfs_create_file(name, mode, dent, fill, &debug_ops);
+}
+
+static int __init smux_debugfs_init(void)
+{
+	struct dentry *dent;
+
+	dent = debugfs_create_dir("n_smux", 0);
+	if (IS_ERR(dent))
+		return PTR_ERR(dent);
+
+	/*
+	 * Add Unit Test entries.
+	 *
+	 * The idea with unit tests is that you can run all of them
+	 * from ADB shell by doing:
+	 *  adb shell
+	 *	cat ut*
+	 *
+	 * And if particular tests fail, you can then repeatedly run the failing
+	 * tests as you debug and resolve the failing test.
+	 */
+	debug_create("ut_local_basic", 0444, dent, smux_ut_basic);
+	debug_create("ut_remote_basic", 0444, dent,	smux_ut_remote_basic);
+	debug_create("ut_local_big_pkt", 0444, dent, smux_ut_local_big_pkt);
+	debug_create("ut_remote_big_pkt", 0444, dent, smux_ut_remote_big_pkt);
+	debug_create("ut_local_tiocm", 0444, dent, smux_ut_local_tiocm);
+	debug_create("ut_remote_tiocm", 0444, dent,	smux_ut_remote_tiocm);
+	debug_create("ut_local_wm", 0444, dent, smux_ut_local_wm);
+	debug_create("ut_local_smuxld_receive_buf", 0444, dent,
+			smux_ut_local_smuxld_receive_buf);
+
+	return 0;
+}
+
+late_initcall(smux_debugfs_init);
+
diff --git a/drivers/video/msm/mdp4_overlay.c b/drivers/video/msm/mdp4_overlay.c
index 311599d..034d6b6 100644
--- a/drivers/video/msm/mdp4_overlay.c
+++ b/drivers/video/msm/mdp4_overlay.c
@@ -1699,7 +1699,8 @@
 			/*
 			 * If solid fill is enabled, flip and scale
 			 * have to be disabled. otherwise, h/w
-			 * underruns.
+			 * underruns. Also flush the pipe inorder
+			 * to take solid fill into effect.
 			 */
 			op_mode = inpdw(rgb_base + 0x0058);
 			op_mode &= ~(MDP4_OP_FLIP_LR + MDP4_OP_SCALEX_EN);
@@ -1707,6 +1708,7 @@
 			outpdw(rgb_base + 0x0058, op_mode);
 			outpdw(rgb_base + 0x50, rgb_src_format);
 			outpdw(rgb_base + 0x1008, constant_color);
+			mdp4_overlay_reg_flush(bg_pipe, 0);
 		}
 	} else if (fg_alpha) {
 		blend_op = (MDP4_BLEND_BG_ALPHA_FG_PIXEL |
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 6395692..47b1fe3 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -151,6 +151,7 @@
 	__REQ_IO_STAT,		/* account I/O stat */
 	__REQ_MIXED_MERGE,	/* merge of different types, fail separately */
 	__REQ_SECURE,		/* secure discard (used with __REQ_DISCARD) */
+	__REQ_SANITIZE,		/* sanitize */
 	__REQ_NR_BITS,		/* stops here */
 };
 
@@ -161,13 +162,14 @@
 #define REQ_SYNC		(1 << __REQ_SYNC)
 #define REQ_META		(1 << __REQ_META)
 #define REQ_DISCARD		(1 << __REQ_DISCARD)
+#define REQ_SANITIZE		(1 << __REQ_SANITIZE)
 #define REQ_NOIDLE		(1 << __REQ_NOIDLE)
 
 #define REQ_FAILFAST_MASK \
 	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 #define REQ_COMMON_MASK \
 	(REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_DISCARD | \
-	 REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE)
+	 REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE | REQ_SANITIZE)
 #define REQ_CLONE_MASK		REQ_COMMON_MASK
 
 #define REQ_RAHEAD		(1 << __REQ_RAHEAD)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1b13021..4dc4b3e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -403,6 +403,7 @@
 #define QUEUE_FLAG_NOXMERGES   15	/* No extended merges */
 #define QUEUE_FLAG_ADD_RANDOM  16	/* Contributes to random pool */
 #define QUEUE_FLAG_SECDISCARD  17	/* supports SECDISCARD */
+#define QUEUE_FLAG_SANITIZE    19	/* supports SANITIZE */
 
 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
 				 (1 << QUEUE_FLAG_STACKABLE)	|	\
@@ -485,6 +486,7 @@
 #define blk_queue_stackable(q)	\
 	test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 #define blk_queue_discard(q)	test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
+#define blk_queue_sanitize(q)	test_bit(QUEUE_FLAG_SANITIZE, &(q)->queue_flags)
 #define blk_queue_secdiscard(q)	(blk_queue_discard(q) && \
 	test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 
@@ -922,6 +924,7 @@
 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
+extern int blkdev_issue_sanitize(struct block_device *bdev, gfp_t gfp_mask);
 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 			sector_t nr_sects, gfp_t gfp_mask);
 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 35e4edf..1c91125 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -317,6 +317,7 @@
 #define BLKPBSZGET _IO(0x12,123)
 #define BLKDISCARDZEROES _IO(0x12,124)
 #define BLKSECDISCARD _IO(0x12,125)
+#define BLKSANITIZE _IO(0x12, 126)
 
 #define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
 #define FIBMAP	   _IO(0x00,1)	/* bmap access */
diff --git a/include/linux/smux.h b/include/linux/smux.h
new file mode 100644
index 0000000..64d0ed6
--- /dev/null
+++ b/include/linux/smux.h
@@ -0,0 +1,295 @@
+/* include/linux/smux.h
+ *
+ * Copyright (c) 2012, Code Aurora Forum. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+#ifndef SMUX_H
+#define SMUX_H
+
+/**
+ * Logical Channel IDs
+ *
+ * This must be identical between local and remote clients.
+ */
+enum {
+	/* Data Ports */
+	SMUX_DATA_0,
+	SMUX_DATA_1,
+	SMUX_DATA_2,
+	SMUX_DATA_3,
+	SMUX_DATA_4,
+	SMUX_DATA_5,
+	SMUX_DATA_6,
+	SMUX_DATA_7,
+	SMUX_DATA_8,
+	SMUX_DATA_9,
+	SMUX_USB_RMNET_DATA_0,
+	SMUX_USB_DUN_0,
+	SMUX_USB_DIAG_0,
+	SMUX_SYS_MONITOR_0,
+	SMUX_CSVT_0,
+	/* add new data ports here */
+
+	/* Control Ports */
+	SMUX_DATA_CTL_0 = 32,
+	SMUX_DATA_CTL_1,
+	SMUX_DATA_CTL_2,
+	SMUX_DATA_CTL_3,
+	SMUX_DATA_CTL_4,
+	SMUX_DATA_CTL_5,
+	SMUX_DATA_CTL_6,
+	SMUX_DATA_CTL_7,
+	SMUX_DATA_CTL_8,
+	SMUX_DATA_CTL_9,
+	SMUX_USB_RMNET_CTL_0,
+	SMUX_USB_DUN_CTL_0_UNUSED,
+	SMUX_USB_DIAG_CTL_0,
+	SMUX_SYS_MONITOR_CTL_0,
+	SMUX_CSVT_CTL_0,
+	/* add new control ports here */
+
+	SMUX_TEST_LCID,
+	SMUX_NUM_LOGICAL_CHANNELS,
+};
+
+/**
+ * Notification events that are passed to the notify() function.
+ *
+ * If the @metadata argument in the notifier is non-null, then it will
+ * point to the associated struct smux_meta_* structure.
+ */
+enum {
+	SMUX_CONNECTED,       /* @metadata is null */
+	SMUX_DISCONNECTED,
+	SMUX_READ_DONE,
+	SMUX_READ_FAIL,
+	SMUX_WRITE_DONE,
+	SMUX_WRITE_FAIL,
+	SMUX_TIOCM_UPDATE,
+	SMUX_LOW_WM_HIT,      /* @metadata is NULL */
+	SMUX_HIGH_WM_HIT,     /* @metadata is NULL */
+};
+
+/**
+ * Channel options used to modify channel behavior.
+ */
+enum {
+	SMUX_CH_OPTION_LOCAL_LOOPBACK = 1 << 0,
+	SMUX_CH_OPTION_REMOTE_LOOPBACK = 1 << 1,
+	SMUX_CH_OPTION_REMOTE_TX_STOP = 1 << 2,
+};
+
+/**
+ * Metadata for SMUX_DISCONNECTED notification
+ *
+ * @is_ssr:  Disconnect caused by subsystem restart
+ */
+struct smux_meta_disconnected {
+	int is_ssr;
+};
+
+/**
+ * Metadata for SMUX_READ_DONE/SMUX_READ_FAIL notification
+ *
+ * @pkt_priv: Packet-specific private data
+ * @buffer:   Buffer pointer passed into msm_smux_write
+ * @len:      Buffer length passed into  msm_smux_write
+ */
+struct smux_meta_read {
+	void *pkt_priv;
+	void *buffer;
+	int len;
+};
+
+/**
+ * Metadata for SMUX_WRITE_DONE/SMUX_WRITE_FAIL notification
+ *
+ * @pkt_priv: Packet-specific private data
+ * @buffer:  Buffer pointer returned by get_rx_buffer()
+ * @len:     Buffer length returned by get_rx_buffer()
+ */
+struct smux_meta_write {
+	void *pkt_priv;
+	void *buffer;
+	int len;
+};
+
+/**
+ * Metadata for SMUX_TIOCM_UPDATE notification
+ *
+ * @tiocm_old:  Previous TIOCM state
+ * @tiocm_new:   Current TIOCM state
+ */
+struct smux_meta_tiocm {
+	uint32_t tiocm_old;
+	uint32_t tiocm_new;
+};
+
+
+#ifdef CONFIG_N_SMUX
+/**
+ * Starts the opening sequence for a logical channel.
+ *
+ * @lcid          Logical channel ID
+ * @priv          Free for client usage
+ * @notify        Event notification function
+ * @get_rx_buffer Function used to provide a receive buffer to SMUX
+ *
+ * @returns 0 for success, <0 otherwise
+ *
+ * A channel must be fully closed (either not previously opened or
+ * msm_smux_close() has been called and the SMUX_DISCONNECTED has been
+ * recevied.
+ *
+ * One the remote side is opened, the client will receive a SMUX_CONNECTED
+ * event.
+ */
+int msm_smux_open(uint8_t lcid, void *priv,
+	void (*notify)(void *priv, int event_type, const void *metadata),
+	int (*get_rx_buffer)(void *priv, void **pkt_priv,
+					void **buffer, int size));
+
+/**
+ * Starts the closing sequence for a logical channel.
+ *
+ * @lcid    Logical channel ID
+ * @returns 0 for success, <0 otherwise
+ *
+ * Once the close event has been acknowledge by the remote side, the client
+ * will receive a SMUX_DISCONNECTED notification.
+ */
+int msm_smux_close(uint8_t lcid);
+
+/**
+ * Write data to a logical channel.
+ *
+ * @lcid      Logical channel ID
+ * @pkt_priv  Client data that will be returned with the SMUX_WRITE_DONE or
+ *            SMUX_WRITE_FAIL notification.
+ * @data      Data to write
+ * @len       Length of @data
+ *
+ * @returns   0 for success, <0 otherwise
+ *
+ * Data may be written immediately after msm_smux_open() is called, but
+ * the data will wait in the transmit queue until the channel has been
+ * fully opened.
+ *
+ * Once the data has been written, the client will receive either a completion
+ * (SMUX_WRITE_DONE) or a failure notice (SMUX_WRITE_FAIL).
+ */
+int msm_smux_write(uint8_t lcid, void *pkt_priv, const void *data, int len);
+
+/**
+ * Returns true if the TX queue is currently full (high water mark).
+ *
+ * @lcid      Logical channel ID
+ *
+ * @returns   0 if channel is not full; 1 if it is full; < 0 for error
+ */
+int msm_smux_is_ch_full(uint8_t lcid);
+
+/**
+ * Returns true if the TX queue has space for more packets it is at or
+ * below the low water mark).
+ *
+ * @lcid      Logical channel ID
+ *
+ * @returns   0 if channel is above low watermark
+ *            1 if it's at or below the low watermark
+ *            < 0 for error
+ */
+int msm_smux_is_ch_low(uint8_t lcid);
+
+/**
+ * Get the TIOCM status bits.
+ *
+ * @lcid      Logical channel ID
+ *
+ * @returns   >= 0 TIOCM status bits
+ *            < 0  Error condition
+ */
+long msm_smux_tiocm_get(uint8_t lcid);
+
+/**
+ * Set/clear the TIOCM status bits.
+ *
+ * @lcid      Logical channel ID
+ * @set       Bits to set
+ * @clear     Bits to clear
+ *
+ * @returns   0 for success; < 0 for failure
+ *
+ * If a bit is specified in both the @set and @clear masks, then the clear bit
+ * definition will dominate and the bit will be cleared.
+ */
+int msm_smux_tiocm_set(uint8_t lcid, uint32_t set, uint32_t clear);
+
+/**
+ * Set or clear channel option using the SMUX_CH_OPTION_* channel
+ * flags.
+ *
+ * @lcid   Logical channel ID
+ * @set    Options to set
+ * @clear  Options to clear
+ *
+ * @returns 0 for success, < 0 for failure
+ */
+int msm_smux_set_ch_option(uint8_t lcid, uint32_t set, uint32_t clear);
+
+#else
+int msm_smux_open(uint8_t lcid, void *priv,
+	void (*notify)(void *priv, int event_type, const void *metadata),
+	int (*get_rx_buffer)(void *priv, void **pkt_priv,
+					void **buffer, int size))
+{
+	return -ENODEV;
+}
+
+int msm_smux_close(uint8_t lcid)
+{
+	return -ENODEV;
+}
+
+int msm_smux_write(uint8_t lcid, void *pkt_priv, const void *data, int len)
+{
+	return -ENODEV;
+}
+
+int msm_smux_is_ch_full(uint8_t lcid);
+{
+	return -ENODEV;
+}
+
+int msm_smux_is_ch_low(uint8_t lcid);
+{
+	return -ENODEV;
+}
+
+long msm_smux_tiocm_get(uint8_t lcid)
+{
+	return 0;
+}
+
+int msm_smux_tiocm_set(uint8_t lcid, uint32_t set, uint32_t clear)
+{
+	return -ENODEV;
+}
+
+int msm_smux_set_ch_option(uint8_t lcid, uint32_t set, uint32_t clear)
+{
+	return -ENODEV;
+}
+
+#endif /* CONFIG_N_SMUX */
+
+#endif /* SMUX_H */
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 1ff6b62..818d189 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -52,6 +52,7 @@
 #define N_TI_WL		22	/* for TI's WL BT, FM, GPS combo chips */
 #define N_TRACESINK	23	/* Trace data routing for MIPI P1149.7 */
 #define N_TRACEROUTER	24	/* Trace data routing for MIPI P1149.7 */
+#define N_SMUX		25	/* Serial MUX */
 
 /*
  * This character is the same as _POSIX_VDISABLE: it cannot be used as
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 6957aa2..fa1d639 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1792,6 +1792,8 @@
 		rwbs[i++] = 'W';
 	else if (rw & REQ_DISCARD)
 		rwbs[i++] = 'D';
+	else if (rw & REQ_SANITIZE)
+		rwbs[i++] = 'Z';
 	else if (bytes)
 		rwbs[i++] = 'R';
 	else