Merge "msm: krait-regulator: use phase management for v2"
diff --git a/Documentation/devicetree/bindings/bif/bif.txt b/Documentation/devicetree/bindings/bif/bif.txt
new file mode 100644
index 0000000..c4ff08b
--- /dev/null
+++ b/Documentation/devicetree/bindings/bif/bif.txt
@@ -0,0 +1,22 @@
+BIF (Battery Interface) Controllers
+
+Optional properties:
+- qcom,known-device-addresses:  Specifies a list of integers which correspond to
+                                the 8-bit BIF bus device addresses of BIF slaves
+                                found on the target.
+
+BIF Consumers
+
+Optional properties:
+- qcom,bif-ctrl:                phandle of parent BIF controller device node
+
+Example:
+	foo_ctrl: foo-controller {
+		...
+		qcom,known-device-addresses = <0x80, 0x81>;
+	};
+
+	bar-consumer {
+		...
+		qcom,bif-ctrl = <&foo_ctrl>;
+	};
diff --git a/Documentation/devicetree/bindings/memory.txt b/Documentation/devicetree/bindings/memory.txt
new file mode 100644
index 0000000..74e0476
--- /dev/null
+++ b/Documentation/devicetree/bindings/memory.txt
@@ -0,0 +1,101 @@
+* Memory binding
+
+The /memory node provides basic information about the address and size
+of the physical memory. This node is usually filled or updated by the
+bootloader, depending on the actual memory configuration of the given
+hardware.
+
+The memory layout is described by the folllowing node:
+
+memory {
+	reg =  <(baseaddr1) (size1)
+		(baseaddr2) (size2)
+		...
+		(baseaddrN) (sizeN)>;
+};
+
+baseaddrX:	the base address of the defined memory bank
+sizeX:		the size of the defined memory bank
+
+More than one memory bank can be defined.
+
+
+* Memory regions
+
+In /memory node one can create additional nodes describing particular
+memory regions, usually for the special usage by various device drivers.
+A good example are contiguous memory allocations or memory sharing with
+other operating system on the same hardware board. Those special memory
+regions might depend on the board configuration and devices used on the
+target system.
+
+Parameters for each memory region can be encoded into the device tree
+wit the following convention:
+
+(name): region@(base-address) {
+	reg = <(baseaddr) (size)>;
+	(linux,contiguous-region);
+	(linux,default-contiguous-region);
+};
+
+name:		an name given to the defined region.
+base-address:	the base address of the defined region.
+size:		the size of the memory region.
+linux,contiguous-region: property indicating that the defined memory
+		region is used for contiguous memory allocations,
+		Linux specific (optional)
+linux,default-contiguous-region: property indicating that the region
+		is the default region for all contiguous memory
+		allocations, Linux specific (optional)
+
+
+* Device nodes
+
+Once the regions in the /memory node are defined, they can be assigned
+to device some device nodes for their special use. The following
+properties are defined:
+
+linux,contiguous-region = <&phandle>;
+	This property indicates that the device driver should use the
+	memory region pointed by the given phandle.
+
+
+* Example:
+
+This example defines a memory consisting of 4 memory banks. 2 contiguous
+regions are defined for Linux kernel, one default of all device drivers
+(named contig_mem, placed at 0x72000000, 64MiB) and one dedicated to the
+framebuffer device (named display_mem, placed at 0x78000000, 16MiB). The
+display_mem region is then assigned to fb@12300000 device for contiguous
+memory allocation with Linux kernel drivers.
+
+The reason for creating a separate region for framebuffer device is to
+match the framebuffer address of from configuration done by bootloader,
+so once Linux kernel drivers starts, no glitches on the displayed boot
+logo appears.
+
+/ {
+	/* ... */
+	memory {
+		reg =  <0x40000000 0x10000000
+			0x50000000 0x10000000
+			0x60000000 0x10000000
+			0x70000000 0x10000000>;
+
+		contig_mem: region@72000000 {
+			linux,contiguous-region;
+			linux,default-contiguous-region;
+			reg = <0x72000000 0x4000000>;
+		};
+
+		display_mem: region@78000000 {
+			linux,contiguous-region;
+			reg = <0x78000000 0x1000000>;
+		};
+	};
+
+	fb@12300000 {
+		linux,contiguous-region = <&display_mem>;
+		status = "okay";
+	};
+};
diff --git a/arch/arm/boot/dts/skeleton.dtsi b/arch/arm/boot/dts/skeleton.dtsi
index b41d241..f9988cd 100644
--- a/arch/arm/boot/dts/skeleton.dtsi
+++ b/arch/arm/boot/dts/skeleton.dtsi
@@ -9,5 +9,10 @@
 	#size-cells = <1>;
 	chosen { };
 	aliases { };
-	memory { device_type = "memory"; reg = <0 0>; };
+	memory {
+		#address-cells = <1>;
+		#size-cells = <1>;
+		device_type = "memory";
+		reg = <0 0>;
+	};
 };
diff --git a/arch/arm/configs/msm8974-perf_defconfig b/arch/arm/configs/msm8974-perf_defconfig
index 952171c..5c03630 100644
--- a/arch/arm/configs/msm8974-perf_defconfig
+++ b/arch/arm/configs/msm8974-perf_defconfig
@@ -356,10 +356,6 @@
 CONFIG_SND_USB_AUDIO=y
 CONFIG_SND_SOC=y
 CONFIG_SND_SOC_MSM8974=y
-CONFIG_UHID=y
-CONFIG_HID_APPLE=y
-CONFIG_HID_MAGICMOUSE=y
-CONFIG_HID_MICROSOFT=y
 CONFIG_USB_SUSPEND=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_EHCI_HCD=y
diff --git a/arch/arm/configs/msm8974_defconfig b/arch/arm/configs/msm8974_defconfig
index a3a4487..faa0471 100644
--- a/arch/arm/configs/msm8974_defconfig
+++ b/arch/arm/configs/msm8974_defconfig
@@ -364,10 +364,6 @@
 CONFIG_SND_USB_AUDIO=y
 CONFIG_SND_SOC=y
 CONFIG_SND_SOC_MSM8974=y
-CONFIG_UHID=y
-CONFIG_HID_APPLE=y
-CONFIG_HID_MAGICMOUSE=y
-CONFIG_HID_MICROSOFT=y
 CONFIG_USB_SUSPEND=y
 CONFIG_USB_XHCI_HCD=y
 CONFIG_USB_EHCI_HCD=y
diff --git a/drivers/Kconfig b/drivers/Kconfig
index a73d713..adead10 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -150,4 +150,6 @@
 
 source "drivers/coresight/Kconfig"
 
+source "drivers/bif/Kconfig"
+
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index f461e83..d55b035 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -142,3 +142,5 @@
 obj-$(CONFIG_MOBICORE_SUPPORT)  += gud/
 
 obj-$(CONFIG_CORESIGHT)		+= coresight/
+
+obj-$(CONFIG_BIF)		+= bif/
diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
index 1937db8..cd341e8 100644
--- a/drivers/base/dma-contiguous.c
+++ b/drivers/base/dma-contiguous.c
@@ -24,6 +24,9 @@
 
 #include <linux/memblock.h>
 #include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_platform.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
 #include <linux/page-isolation.h>
@@ -181,6 +184,35 @@
 	return ERR_PTR(ret);
 }
 
+/*****************************************************************************/
+
+#ifdef CONFIG_OF
+int __init cma_fdt_scan(unsigned long node, const char *uname,
+				int depth, void *data)
+{
+	phys_addr_t base, size;
+	unsigned long len;
+	__be32 *prop;
+
+	if (strncmp(uname, "region@", 7) != 0 || depth != 2 ||
+	    !of_get_flat_dt_prop(node, "contiguous-region", NULL))
+		return 0;
+
+	prop = of_get_flat_dt_prop(node, "reg", &len);
+	if (!prop || (len != 2 * sizeof(unsigned long)))
+		return 0;
+
+	base = be32_to_cpu(prop[0]);
+	size = be32_to_cpu(prop[1]);
+
+	pr_info("Found %s, memory base %lx, size %ld MiB\n", uname,
+		(unsigned long)base, (unsigned long)size / SZ_1M);
+	dma_contiguous_reserve_area(size, &base, 0);
+
+	return 0;
+}
+#endif
+
 /**
  * dma_contiguous_reserve() - reserve area for contiguous memory handling
  * @limit: End address of the reserved memory (optional, 0 for any).
@@ -219,6 +251,9 @@
 		if (dma_contiguous_reserve_area(sel_size, &base, limit) == 0)
 			dma_contiguous_def_base = base;
 	}
+#ifdef CONFIG_OF
+	of_scan_flat_dt(cma_fdt_scan, NULL);
+#endif
 };
 
 /**
@@ -323,6 +358,40 @@
 	return 0;
 }
 
+#ifdef CONFIG_OF
+static void cma_assign_device_from_dt(struct device *dev)
+{
+	struct device_node *node;
+	struct cma *cma;
+	u32 value;
+
+	node = of_parse_phandle(dev->of_node, "linux,contiguous-region", 0);
+	if (!node)
+		return;
+	if (of_property_read_u32(node, "reg", &value) && !value)
+		return;
+	cma = cma_get_area(value);
+	if (!cma)
+		return;
+
+	dev_set_cma_area(dev, cma);
+	pr_info("Assigned CMA region at %lx to %s device\n", (unsigned long)value, dev_name(dev));
+}
+
+static int cma_device_init_notifier_call(struct notifier_block *nb,
+					 unsigned long event, void *data)
+{
+	struct device *dev = data;
+	if (event == BUS_NOTIFY_ADD_DEVICE && dev->of_node)
+		cma_assign_device_from_dt(dev);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block cma_dev_init_nb = {
+	.notifier_call = cma_device_init_notifier_call,
+};
+#endif
+
 static int __init cma_init_reserved_areas(void)
 {
 	struct cma *cma;
@@ -344,6 +413,9 @@
 		dev_set_cma_area(cma_maps[i].dev, cma);
 	}
 
+#ifdef CONFIG_OF
+	bus_register_notifier(&platform_bus_type, &cma_dev_init_nb);
+#endif
 	return 0;
 }
 core_initcall(cma_init_reserved_areas);
diff --git a/drivers/bif/Kconfig b/drivers/bif/Kconfig
new file mode 100644
index 0000000..502b92b
--- /dev/null
+++ b/drivers/bif/Kconfig
@@ -0,0 +1,12 @@
+#
+# BIF framework and drivers
+#
+menuconfig BIF
+	bool "MIPI-BIF support"
+	select CRC_CCITT
+	select BITREVERSE
+	help
+	  MIPI-BIF (battery interface) is a one-wire serial interface between a
+	  host master device and one or more slave devices which are located in
+	  a battery pack or also on the host.  Enabling this option allows for
+	  BIF consumer drivers to issue transactions via BIF controller drivers.
diff --git a/drivers/bif/Makefile b/drivers/bif/Makefile
new file mode 100644
index 0000000..02528c1
--- /dev/null
+++ b/drivers/bif/Makefile
@@ -0,0 +1,4 @@
+#
+# Makefile for kernel BIF framework.
+#
+obj-$(CONFIG_BIF)			+= bif-core.o
diff --git a/drivers/bif/bif-core.c b/drivers/bif/bif-core.c
new file mode 100644
index 0000000..e11e6ba4
--- /dev/null
+++ b/drivers/bif/bif-core.c
@@ -0,0 +1,2934 @@
+/* Copyright (c) 2013, The Linux Foundation. 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.
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/bitrev.h>
+#include <linux/crc-ccitt.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/workqueue.h>
+#include <linux/bif/consumer.h>
+#include <linux/bif/driver.h>
+
+/**
+ * struct bif_ctrl_dev - holds controller device specific information
+ * @list:			Doubly-linked list parameter linking to other
+ *				BIF controllers registered in the system
+ * @desc:			Description structure for this BIF controller
+ * @mutex:			Mutex lock that is used to ensure mutual
+ *				exclusion between transactions performed on the
+ *				BIF bus for this controller
+ * @ctrl_dev:			Device pointer to the BIF controller device
+ * @driver_data:		Private data used by the BIF controller
+ * @selected_sdev:		Slave device that is currently selected on
+ *				the BIF bus of this controller
+ * @bus_change_notifier:	Head of a notifier list containing notifier
+ *				blocks that are notified when the battery
+ *				presence changes
+ * @enter_irq_mode_work:	Work task that is scheduled after a transaction
+ *				completes when there are consumers that are
+ *				actively monitoring BIF slave interrupts
+ * @irq_count:			This is a count of the total number of BIF slave
+ *				interrupts that are currently being monitored
+ *				for the BIF slaves connected to this BIF
+ *				controller
+ * @irq_mode_delay_jiffies:	Number of jiffies to wait before scheduling the
+ *				enter IRQ mode task.  Using a larger value
+ *				helps to improve the performance of BIF
+ *				consumers that perform many BIF transactions.
+ *				Using a smaller value reduces the latency of
+ *				BIF slave interrupts.
+ * @battery_present:		Cached value of the battery presence.  This is
+ *				used to filter out spurious presence update
+ *				calls when the battery presence state has not
+ *				changed.
+ */
+struct bif_ctrl_dev {
+	struct list_head		list;
+	struct bif_ctrl_desc		*desc;
+	struct mutex			mutex;
+	struct device			*ctrl_dev;
+	void				*driver_data;
+	struct bif_slave_dev		*selected_sdev;
+	struct blocking_notifier_head	bus_change_notifier;
+	struct delayed_work		enter_irq_mode_work;
+	int				irq_count;
+	int				irq_mode_delay_jiffies;
+	bool				battery_present;
+};
+
+/**
+ * struct bif_ctrl - handle used by BIF consumers for bus oriented BIF
+ *			operations
+ * @bdev:		Pointer to BIF controller device
+ * @exclusive_lock:	Flag which indicates that the BIF consumer responsible
+ *			for this handle has locked the BIF bus of this
+ *			controller.  BIF transactions from other consumers are
+ *			blocked until the bus is unlocked.
+ */
+struct bif_ctrl {
+	struct bif_ctrl_dev	*bdev;
+	bool			exclusive_lock;
+};
+
+/**
+ * struct bif_slave_dev - holds BIF slave device information
+ * @list:			Doubly-linked list parameter linking to other
+ *				BIF slaves that have been enumerated
+ * @bdev:			Pointer to the BIF controller device that this
+ *				slave is physically connected to
+ * @slave_addr:			8-bit BIF DEV_ADR assigned to this slave
+ * @unique_id:			80-bit BIF unique ID of the slave
+ * @unique_id_bits_known:	Number of bits of the UID that are currently
+ *				known.  This number starts is incremented during
+ *				a UID search and must end at 80 if the slave
+ *				responds to the search properly.
+ * @present:			Boolean value showing if this slave is
+*				physically present in the system at a given
+*				point in time.  The value is set to false if the
+*				battery pack containing the slave is
+*				disconnected.
+ * @l1_data:			BIF DDB L1 data of the slave as read from the
+ *				slave's memory
+ * @function_directory:		Pointer to the BIF DDB L2 function directory
+ *				list as read from the slave's memory
+ * @protocol_function:		Pointer to constant protocol function data as
+ *				well as software state information if the slave
+ *				has a protocol function
+ * @slave_ctrl_function:	Pointer to constant slave control function data
+ *				as well as software state information if the
+ *				slave has a slave control function
+ * @nvm_function:		Pointer to constant non-volatile memory function
+ *				data as well as software state information if
+ *				the slave has a non-volatile memory function
+ *
+ * bif_slave_dev objects are stored indefinitely after enumeration in order to
+ * speed up battery reinsertion.  Only a UID check is needed after inserting a
+ * battery assuming it has been enumerated before.
+ *
+ * unique_id bytes are stored such that unique_id[0] = MSB and
+ * unique_id[BIF_UNIQUE_ID_BYTE_LENGTH - 1] = LSB
+ */
+struct bif_slave_dev {
+	struct list_head			list;
+	struct bif_ctrl_dev			*bdev;
+	u8					slave_addr;
+	u8				unique_id[BIF_UNIQUE_ID_BYTE_LENGTH];
+	int					unique_id_bits_known;
+	bool					present;
+	struct bif_ddb_l1_data			l1_data;
+	struct bif_ddb_l2_data			*function_directory;
+	struct bif_protocol_function		*protocol_function;
+	struct bif_slave_control_function	*slave_ctrl_function;
+	struct bif_nvm_function			*nvm_function;
+};
+
+/**
+ * struct bif_slave - handle used by BIF consumers for slave oriented BIF
+ *			operations
+ * @ctrl:		Consumer BIF controller handle data
+ * @sdev:		Pointer to BIF slave device
+ */
+struct bif_slave {
+	struct bif_ctrl				ctrl;
+	struct bif_slave_dev			*sdev;
+};
+
+/* Number of times to retry a full BIF transaction before returning an error. */
+#define BIF_TRANSACTION_RETRY_COUNT	5
+
+static DEFINE_MUTEX(bif_ctrl_list_mutex);
+static LIST_HEAD(bif_ctrl_list);
+static DEFINE_MUTEX(bif_sdev_list_mutex);
+static LIST_HEAD(bif_sdev_list);
+
+static u8 next_dev_addr = 0x02;
+
+#define DEBUG_PRINT_BUFFER_SIZE 256
+static void fill_string(char *str, size_t str_len, u8 *buf, int buf_len)
+{
+	int pos = 0;
+	int i;
+
+	for (i = 0; i < buf_len; i++) {
+		pos += scnprintf(str + pos, str_len - pos, "0x%02X", buf[i]);
+		if (i < buf_len - 1)
+			pos += scnprintf(str + pos, str_len - pos, ", ");
+	}
+}
+
+static void bif_print_slave_data(struct bif_slave_dev *sdev)
+{
+	char str[DEBUG_PRINT_BUFFER_SIZE];
+	u8 *uid;
+	int i, j;
+	struct bif_object *object;
+
+	if (sdev->unique_id_bits_known != BIF_UNIQUE_ID_BIT_LENGTH)
+		return;
+
+	uid = sdev->unique_id;
+	pr_debug("BIF slave: 0x%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X\n",
+		uid[0], uid[1], uid[2], uid[3], uid[4], uid[5], uid[6],
+		uid[7], uid[8], uid[9]);
+	pr_debug("  present=%d, dev_adr=0x%02X\n", sdev->present,
+		sdev->slave_addr);
+	pr_debug("  revision=0x%02X, level=0x%02X, device class=0x%04X\n",
+		sdev->l1_data.revision, sdev->l1_data.level,
+		sdev->l1_data.device_class);
+	pr_debug("  manufacturer ID=0x%04X, product ID=0x%04X\n",
+		sdev->l1_data.manufacturer_id, sdev->l1_data.product_id);
+	pr_debug("  function directory length=%d\n", sdev->l1_data.length);
+
+	for (i = 0; i < sdev->l1_data.length / 4; i++) {
+		pr_debug("  Function %d: type=0x%02X, version=0x%02X, pointer=0x%04X\n",
+			i, sdev->function_directory[i].function_type,
+			sdev->function_directory[i].function_version,
+			sdev->function_directory[i].function_pointer);
+	}
+
+	if (sdev->nvm_function) {
+		pr_debug("  NVM function: pointer=0x%04X, task=%d, wr_buf_size=%d, nvm_base=0x%04X, nvm_size=%d\n",
+			sdev->nvm_function->nvm_pointer,
+			sdev->nvm_function->slave_control_channel,
+			(sdev->nvm_function->write_buffer_size
+				? sdev->nvm_function->write_buffer_size : 0),
+			sdev->nvm_function->nvm_base_address,
+			sdev->nvm_function->nvm_size);
+		if (sdev->nvm_function->object_count)
+			pr_debug("  NVM objects:\n");
+		i = 0;
+		list_for_each_entry(object, &sdev->nvm_function->object_list,
+					list) {
+			pr_debug("    Object %d - addr=0x%04X, data len=%d, type=0x%02X, version=0x%02X, manufacturer ID=0x%04X, crc=0x%04X\n",
+				i, object->addr, object->length - 8,
+				object->type, object->version,
+				object->manufacturer_id, object->crc);
+			for (j = 0; j < DIV_ROUND_UP(object->length - 8, 16);
+					j++) {
+				fill_string(str, DEBUG_PRINT_BUFFER_SIZE,
+					object->data + j * 16,
+					min(16, object->length - 8 - (j * 16)));
+				pr_debug("      data(0x%04X): %s\n", j * 16,
+					str);
+			}
+			i++;
+		}
+	}
+}
+
+static void bif_print_slaves(void)
+{
+	struct bif_slave_dev *sdev;
+
+	mutex_lock(&bif_sdev_list_mutex);
+
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		/* Skip slaves without fully known UIDs. */
+		if (sdev->unique_id_bits_known != BIF_UNIQUE_ID_BIT_LENGTH)
+			continue;
+		bif_print_slave_data(sdev);
+	}
+
+	mutex_unlock(&bif_sdev_list_mutex);
+}
+
+static struct bif_slave_dev *bif_add_slave(struct bif_ctrl_dev *bdev)
+{
+	struct bif_slave_dev *sdev;
+
+	sdev = kzalloc(sizeof(struct bif_slave_dev), GFP_KERNEL);
+	if (sdev == NULL) {
+		pr_err("Memory allocation failed for bif_slave_dev\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	sdev->bdev = bdev;
+	INIT_LIST_HEAD(&sdev->list);
+	list_add_tail(&sdev->list, &bif_sdev_list);
+
+	return sdev;
+}
+
+static void bif_remove_slave(struct bif_slave_dev *sdev)
+{
+	list_del(&sdev->list);
+	if (sdev->bdev->selected_sdev == sdev)
+		sdev->bdev->selected_sdev = NULL;
+
+	if (sdev->slave_ctrl_function)
+		kfree(sdev->slave_ctrl_function->irq_notifier_list);
+	kfree(sdev->slave_ctrl_function);
+	kfree(sdev->protocol_function);
+	kfree(sdev->function_directory);
+
+	kfree(sdev);
+}
+
+/* This function assumes that the uid array is all 0 to start with. */
+static void set_uid_bit(u8 uid[BIF_UNIQUE_ID_BYTE_LENGTH], unsigned int bit,
+			unsigned int value)
+{
+	u8 mask;
+
+	if (bit >= BIF_UNIQUE_ID_BIT_LENGTH)
+		return;
+
+	mask = 1 << (7 - (bit % 8));
+
+	uid[bit / 8] &= ~mask;
+	uid[bit / 8] |= value << (7 - (bit % 8));
+}
+
+static unsigned int get_uid_bit(u8 uid[BIF_UNIQUE_ID_BYTE_LENGTH],
+			unsigned int bit)
+{
+	if (bit >= BIF_UNIQUE_ID_BIT_LENGTH)
+		return 0;
+
+	return (uid[bit / 8] & (1 << (7 - (bit % 8)))) ? 1 : 0;
+}
+
+static void bif_enter_irq_mode_work(struct work_struct *work)
+{
+	struct delayed_work *dwork = to_delayed_work(work);
+	struct bif_ctrl_dev *bdev
+		= container_of(dwork, struct bif_ctrl_dev, enter_irq_mode_work);
+	int rc, i;
+
+	mutex_lock(&bdev->mutex);
+	for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+		rc = bdev->desc->ops->set_bus_state(bdev,
+					BIF_BUS_STATE_INTERRUPT);
+		if (rc == 0)
+			break;
+	}
+	mutex_unlock(&bdev->mutex);
+
+	/* Reschedule the task if the transaction failed. */
+	if (rc) {
+		pr_err("Could not set BIF bus to interrupt mode, rc=%d\n", rc);
+		schedule_delayed_work(&bdev->enter_irq_mode_work,
+					bdev->irq_mode_delay_jiffies);
+	}
+}
+
+static void bif_cancel_irq_mode_work(struct bif_ctrl_dev *bdev)
+{
+	cancel_delayed_work(&bdev->enter_irq_mode_work);
+}
+
+static void bif_schedule_irq_mode_work(struct bif_ctrl_dev *bdev)
+{
+	if (bdev->irq_count > 0 &&
+	    bdev->desc->ops->get_bus_state(bdev) != BIF_BUS_STATE_INTERRUPT)
+		schedule_delayed_work(&bdev->enter_irq_mode_work,
+					bdev->irq_mode_delay_jiffies);
+}
+
+static int _bif_select_slave_no_retry(struct bif_slave_dev *sdev)
+{
+	struct bif_ctrl_dev *bdev = sdev->bdev;
+	int rc = 0;
+	int i;
+
+	/* Check if the slave is already selected. */
+	if (sdev->bdev->selected_sdev == sdev)
+		return 0;
+
+	if (sdev->slave_addr) {
+		/* Select using DEV_ADR. */
+		rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_SDA,
+							sdev->slave_addr);
+		if (!rc)
+			sdev->bdev->selected_sdev = sdev;
+	} else if (sdev->unique_id_bits_known == BIF_UNIQUE_ID_BIT_LENGTH) {
+		/* Select using full UID. */
+		for (i = 0; i < BIF_UNIQUE_ID_BYTE_LENGTH - 1; i++) {
+			rc = bdev->desc->ops->bus_transaction(bdev,
+				BIF_TRANS_EDA, sdev->unique_id[i]);
+			if (rc)
+				goto out;
+		}
+
+		rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_SDA,
+			sdev->unique_id[BIF_UNIQUE_ID_BYTE_LENGTH - 1]);
+		if (rc)
+			goto out;
+	} else {
+		pr_err("Cannot select slave because it has neither UID nor DEV_ADR.\n");
+		return -EINVAL;
+	}
+
+	sdev->bdev->selected_sdev = sdev;
+
+	return 0;
+out:
+	pr_err("bus_transaction failed, rc=%d\n", rc);
+	return rc;
+}
+
+static int bif_select_slave(struct bif_slave_dev *sdev)
+{
+	int rc = -EPERM;
+	int i;
+
+	for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+		rc = _bif_select_slave_no_retry(sdev);
+		if (rc == 0)
+			break;
+		/* Force slave reselection. */
+		sdev->bdev->selected_sdev = NULL;
+	}
+
+	return rc;
+}
+
+/*
+ * Returns 1 if slave is selected, 0 if slave is not selected, or errno if
+ * error.
+ */
+static int bif_is_slave_selected(struct bif_ctrl_dev *bdev)
+{
+	int rc = -EPERM;
+	int tack, i;
+
+	for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+		/* Attempt a transaction query. */
+		rc = bdev->desc->ops->bus_transaction_read(bdev, BIF_TRANS_BC,
+						BIF_CMD_TQ, &tack);
+		if (rc == 0 || rc == -ETIMEDOUT)
+			break;
+	}
+
+	if (rc == 0)
+		rc = 1;
+	else if (rc == -ETIMEDOUT)
+		rc = 0;
+	else
+		pr_err("BIF bus_transaction_read failed, rc=%d\n", rc);
+
+	return rc;
+}
+
+/* Read from a specified number of consecutive registers. */
+static int _bif_slave_read_no_retry(struct bif_slave_dev *sdev, u16 addr,
+			u8 *buf, int len)
+{
+	struct bif_ctrl_dev *bdev = sdev->bdev;
+	int rc = 0;
+	int i, response;
+
+	rc = bif_select_slave(sdev);
+	if (rc)
+		return rc;
+
+	if (bdev->desc->ops->read_slave_registers) {
+		/*
+		 * Use low level slave register read implementation in order to
+		 * receive the benefits of BIF burst reads.
+		 */
+		rc = bdev->desc->ops->read_slave_registers(bdev, addr, buf,
+							   len);
+		if (rc)
+			pr_err("read_slave_registers failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	for (i = 0; i < len; i++) {
+		rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_ERA,
+							addr >> 8);
+		if (rc) {
+			pr_err("bus_transaction failed, rc=%d\n", rc);
+			return rc;
+		}
+
+		rc = bdev->desc->ops->bus_transaction_read(bdev, BIF_TRANS_RRA,
+							addr & 0xFF, &response);
+		if (rc) {
+			pr_err("bus_transaction_read failed, rc=%d\n", rc);
+			return rc;
+		}
+
+		if (!(response & BIF_SLAVE_RD_ACK)) {
+			pr_err("BIF register read error=0x%02X\n",
+				response & BIF_SLAVE_RD_ERR);
+			return -EIO;
+		}
+
+		buf[i] = response & BIF_SLAVE_RD_DATA;
+		addr++;
+	}
+
+	return rc;
+}
+
+/*
+ * Read from a specified number of consecutive registers.  Retry the transaction
+ * several times in case of communcation failures.
+ */
+static int _bif_slave_read(struct bif_slave_dev *sdev, u16 addr, u8 *buf,
+			int len)
+{
+	int rc = -EPERM;
+	int i;
+
+	for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+		rc = _bif_slave_read_no_retry(sdev, addr, buf, len);
+		if (rc == 0)
+			break;
+		/* Force slave reselection. */
+		sdev->bdev->selected_sdev = NULL;
+	}
+
+	return rc;
+}
+
+/* Write to a specified number of consecutive registers. */
+static int _bif_slave_write_no_retry(struct bif_slave_dev *sdev, u16 addr,
+			u8 *buf, int len)
+{
+	struct bif_ctrl_dev *bdev = sdev->bdev;
+	int rc = 0;
+	int i;
+
+	rc = bif_select_slave(sdev);
+	if (rc)
+		return rc;
+
+	if (bdev->desc->ops->write_slave_registers) {
+		/*
+		 * Use low level slave register write implementation in order to
+		 * receive the benefits of BIF burst writes.
+		 */
+		rc = bdev->desc->ops->write_slave_registers(bdev, addr, buf,
+							    len);
+		if (rc)
+			pr_err("write_slave_registers failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_ERA, addr >> 8);
+	if (rc)
+		goto out;
+
+	rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_WRA, addr & 0xFF);
+	if (rc)
+		goto out;
+
+	for (i = 0; i < len; i++) {
+		rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_WD,
+							buf[i]);
+		if (rc)
+			goto out;
+	}
+
+	return 0;
+out:
+	pr_err("bus_transaction failed, rc=%d\n", rc);
+	return rc;
+}
+
+/*
+ * Write to a specified number of consecutive registers.  Retry the transaction
+ * several times in case of communcation failures.
+ */
+static int _bif_slave_write(struct bif_slave_dev *sdev, u16 addr, u8 *buf,
+			int len)
+{
+	int rc = -EPERM;
+	int i;
+
+	for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+		rc = _bif_slave_write_no_retry(sdev, addr, buf, len);
+		if (rc == 0)
+			break;
+		/* Force slave reselection. */
+		sdev->bdev->selected_sdev = NULL;
+	}
+
+	return rc;
+}
+
+/* Takes a mutex if this consumer is not an exclusive bus user. */
+static void bif_ctrl_lock(struct bif_ctrl *ctrl)
+{
+	if (!ctrl->exclusive_lock) {
+		mutex_lock(&ctrl->bdev->mutex);
+		bif_cancel_irq_mode_work(ctrl->bdev);
+	}
+}
+
+/* Releases a mutex if this consumer is not an exclusive bus user. */
+static void bif_ctrl_unlock(struct bif_ctrl *ctrl)
+{
+	if (!ctrl->exclusive_lock) {
+		bif_schedule_irq_mode_work(ctrl->bdev);
+		mutex_unlock(&ctrl->bdev->mutex);
+	}
+}
+
+static void bif_slave_ctrl_lock(struct bif_slave *slave)
+{
+	bif_ctrl_lock(&slave->ctrl);
+}
+
+static void bif_slave_ctrl_unlock(struct bif_slave *slave)
+{
+	bif_ctrl_unlock(&slave->ctrl);
+}
+
+static int bif_check_task(struct bif_slave *slave, unsigned int task)
+{
+	if (IS_ERR_OR_NULL(slave)) {
+		pr_err("Invalid slave handle.\n");
+		return -EINVAL;
+	} else if (!slave->sdev->bdev) {
+		pr_err("BIF controller has been removed.\n");
+		return -ENXIO;
+	} else if (!slave->sdev->slave_ctrl_function
+			|| slave->sdev->slave_ctrl_function->task_count == 0) {
+		pr_err("BIF slave does not support slave control.\n");
+		return -ENODEV;
+	} else if (task >= slave->sdev->slave_ctrl_function->task_count) {
+		pr_err("Requested task: %u greater than max: %u for this slave\n",
+			task, slave->sdev->slave_ctrl_function->task_count);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * bif_request_irq() - request a BIF slave IRQ by slave task number
+ * @slave:	BIF slave handle
+ * @task:	BIF task number of the IRQ inside of the slave.  This
+ *		corresponds to the slave control channel specified for a given
+ *		BIF function inside of the slave.
+ * @nb:		Notifier block to call when the IRQ fires
+ *
+ * This function registers a notifier block to call when the BIF slave interrupt
+ * is triggered and also enables the interrupt.  The interrupt is enabled inside
+ * of the BIF slave's slave control function and also the BIF bus is put into
+ * interrupt mode.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_request_irq(struct bif_slave *slave, unsigned int task,
+			struct notifier_block *nb)
+{
+	int rc;
+	u16 addr;
+	u8 reg, mask;
+
+	rc = bif_check_task(slave, task);
+	if (rc) {
+		pr_err("Invalid slave or task, rc=%d\n", rc);
+		return rc;
+	}
+
+	bif_slave_ctrl_lock(slave);
+
+	rc = blocking_notifier_chain_register(
+		&slave->sdev->slave_ctrl_function->irq_notifier_list[task], nb);
+	if (rc) {
+		pr_err("Notifier registration failed, rc=%d\n", rc);
+		goto done;
+	}
+
+	/* Enable the interrupt within the slave */
+	mask = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+	addr = SLAVE_CTRL_FUNC_IRQ_EN_ADDR(
+		slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+	if (task / SLAVE_CTRL_TASKS_PER_SET == 0) {
+		/* Set global interrupt enable. */
+		mask |= BIT(0);
+	}
+	rc = _bif_slave_read(slave->sdev, addr, &reg, 1);
+	if (rc) {
+		pr_err("BIF slave register read failed, rc=%d\n", rc);
+		goto notifier_unregister;
+	}
+	reg |= mask;
+	rc = _bif_slave_write(slave->sdev, addr, &reg, 1);
+	if (rc) {
+		pr_err("BIF slave register write failed, rc=%d\n", rc);
+		goto notifier_unregister;
+	}
+
+	/* Set global interrupt enable if task not in set 0. */
+	if (task / SLAVE_CTRL_TASKS_PER_SET != 0) {
+		mask = BIT(0);
+		addr = SLAVE_CTRL_FUNC_IRQ_EN_ADDR(
+		       slave->sdev->slave_ctrl_function->slave_ctrl_pointer, 0);
+		rc = _bif_slave_read(slave->sdev, addr, &reg, 1);
+		if (rc) {
+			pr_err("BIF slave register read failed, rc=%d\n", rc);
+			goto notifier_unregister;
+		}
+		reg |= mask;
+		rc = _bif_slave_write(slave->sdev, addr, &reg, 1);
+		if (rc) {
+			pr_err("BIF slave register write failed, rc=%d\n", rc);
+			goto notifier_unregister;
+		}
+	}
+
+	rc = slave->sdev->bdev->desc->ops->set_bus_state(slave->sdev->bdev,
+		BIF_BUS_STATE_INTERRUPT);
+	if (rc) {
+		pr_err("Could not set BIF bus to interrupt mode, rc=%d\n", rc);
+		goto notifier_unregister;
+	}
+
+	slave->sdev->bdev->irq_count++;
+done:
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+
+notifier_unregister:
+	blocking_notifier_chain_unregister(
+		&slave->sdev->slave_ctrl_function->irq_notifier_list[task],
+		nb);
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+
+}
+EXPORT_SYMBOL(bif_request_irq);
+
+/**
+ * bif_free_irq() - free a BIF slave IRQ by slave task number
+ * @slave:	BIF slave handle
+ * @task:	BIF task number of the IRQ inside of the slave.  This
+ *		corresponds to the slave control channel specified for a given
+ *		BIF function inside of the slave.
+ * @nb:		Notifier block previously registered with this interrupt
+ *
+ * This function unregisters a notifier block that was previously registered
+ * with bif_request_irq().
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_free_irq(struct bif_slave *slave, unsigned int task,
+			struct notifier_block *nb)
+{
+	int rc;
+	u16 addr;
+	u8 reg;
+
+	rc = bif_check_task(slave, task);
+	if (rc) {
+		pr_err("Invalid slave or task, rc=%d\n", rc);
+		return rc;
+	}
+
+	bif_slave_ctrl_lock(slave);
+
+	/* Disable the interrupt within the slave */
+	reg = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+	addr = SLAVE_CTRL_FUNC_IRQ_CLEAR_ADDR(
+		slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+	rc = _bif_slave_write(slave->sdev, addr, &reg, 1);
+	if (rc) {
+		pr_err("BIF slave register write failed, rc=%d\n", rc);
+		goto done;
+	}
+
+	rc = blocking_notifier_chain_unregister(
+		&slave->sdev->slave_ctrl_function->irq_notifier_list[task], nb);
+	if (rc) {
+		pr_err("Notifier unregistration failed, rc=%d\n", rc);
+		goto done;
+	}
+
+	slave->sdev->bdev->irq_count--;
+
+	if (slave->sdev->bdev->irq_count == 0) {
+		bif_cancel_irq_mode_work(slave->sdev->bdev);
+	} else if (slave->sdev->bdev->irq_count < 0) {
+		pr_err("Unbalanced IRQ free.\n");
+		rc = -EINVAL;
+		slave->sdev->bdev->irq_count = 0;
+	}
+done:
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_free_irq);
+
+/**
+ * bif_trigger_task() - trigger a task within a BIF slave
+ * @slave:	BIF slave handle
+ * @task:	BIF task inside of the slave to trigger.  This corresponds to
+ *		the slave control channel specified for a given BIF function
+ *		inside of the slave.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_trigger_task(struct bif_slave *slave, unsigned int task)
+{
+	int rc;
+	u16 addr;
+	u8 reg;
+
+	rc = bif_check_task(slave, task);
+	if (rc) {
+		pr_err("Invalid slave or task, rc=%d\n", rc);
+		return rc;
+	}
+
+	bif_slave_ctrl_lock(slave);
+
+	/* Trigger the task within the slave. */
+	reg = BIT(task % SLAVE_CTRL_TASKS_PER_SET);
+	addr = SLAVE_CTRL_FUNC_TASK_TRIGGER_ADDR(
+		slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+	rc = _bif_slave_write(slave->sdev, addr, &reg, 1);
+	if (rc) {
+		pr_err("BIF slave register write failed, rc=%d\n", rc);
+		goto done;
+	}
+
+done:
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_trigger_task);
+
+/**
+ * bif_task_is_busy() - checks the state of a BIF slave task
+ * @slave:	BIF slave handle
+ * @task:	BIF task inside of the slave to trigger.  This corresponds to
+ *		the slave control channel specified for a given	BIF function
+ *		inside of the slave.
+ *
+ * Returns 1 if the task is busy, 0 if it is not busy, and errno on error.
+ */
+int bif_task_is_busy(struct bif_slave *slave, unsigned int task)
+{
+	int rc;
+	u16 addr;
+	u8 reg;
+
+	rc = bif_check_task(slave, task);
+	if (rc) {
+		pr_err("Invalid slave or task, rc=%d\n", rc);
+		return rc;
+	}
+
+	bif_slave_ctrl_lock(slave);
+
+	/* Check the task busy state. */
+	addr = SLAVE_CTRL_FUNC_TASK_BUSY_ADDR(
+		slave->sdev->slave_ctrl_function->slave_ctrl_pointer, task);
+	rc = _bif_slave_read(slave->sdev, addr, &reg, 1);
+	if (rc) {
+		pr_err("BIF slave register read failed, rc=%d\n", rc);
+		goto done;
+	}
+
+	rc = (reg & BIT(task % SLAVE_CTRL_TASKS_PER_SET)) ? 1 : 0;
+done:
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_task_is_busy);
+
+static int bif_slave_notify_irqs(struct bif_slave_dev *sdev, int set, u8 val)
+{
+	int rc = 0;
+	int i, task;
+
+	for (i = 0; i < SLAVE_CTRL_TASKS_PER_SET; i++) {
+		if (val & (1 << i)) {
+			task = set * SLAVE_CTRL_TASKS_PER_SET + i;
+
+			rc = blocking_notifier_call_chain(
+			    &sdev->slave_ctrl_function->irq_notifier_list[task],
+			    task, sdev->bdev);
+			rc = notifier_to_errno(rc);
+			if (rc)
+				pr_err("Notification failed for task %d\n",
+					task);
+		}
+	}
+
+	return rc;
+}
+
+static int bif_slave_handle_irq(struct bif_slave_dev *sdev)
+{
+	struct bif_ctrl_dev *bdev = sdev->bdev;
+	bool resp = false;
+	int rc = 0;
+	int i;
+	u16 addr;
+	u8 reg;
+
+	mutex_lock(&sdev->bdev->mutex);
+	bif_cancel_irq_mode_work(sdev->bdev);
+
+	rc = bif_select_slave(sdev);
+	if (rc) {
+		pr_err("Could not select slave, rc=%d\n", rc);
+		goto done;
+	}
+
+	/* Check overall slave interrupt status. */
+	rc = bdev->desc->ops->bus_transaction_query(bdev, BIF_TRANS_BC,
+						    BIF_CMD_ISTS, &resp);
+	if (rc) {
+		pr_err("Could not query slave interrupt status, rc=%d\n", rc);
+		goto done;
+	}
+
+	if (resp) {
+		for (i = 0; i < sdev->slave_ctrl_function->task_count
+					/ SLAVE_CTRL_TASKS_PER_SET; i++) {
+			addr = sdev->slave_ctrl_function->slave_ctrl_pointer
+				+ 4 * i + 1;
+			rc = _bif_slave_read(sdev, addr, &reg, 1);
+			if (rc) {
+				pr_err("BIF slave register read failed, rc=%d\n",
+					rc);
+				goto done;
+			}
+
+			/* Ensure that interrupts are pending in the set. */
+			if (reg != 0x00) {
+				/*
+				 * Release mutex before notifying consumers so
+				 * that they can use the bus.
+				 */
+				mutex_unlock(&sdev->bdev->mutex);
+				rc = bif_slave_notify_irqs(sdev, i, reg);
+				if (rc) {
+					pr_err("BIF slave irq notification failed, rc=%d\n",
+						rc);
+					goto notification_failed;
+				}
+				mutex_lock(&sdev->bdev->mutex);
+
+				rc = bif_select_slave(sdev);
+				if (rc) {
+					pr_err("Could not select slave, rc=%d\n",
+						rc);
+					goto done;
+				}
+
+				/* Clear all interrupts in this set. */
+				rc = _bif_slave_write(sdev, addr, &reg, 1);
+				if (rc) {
+					pr_err("BIF slave register write failed, rc=%d\n",
+						rc);
+					goto done;
+				}
+			}
+		}
+	}
+
+done:
+	bif_schedule_irq_mode_work(sdev->bdev);
+	mutex_unlock(&sdev->bdev->mutex);
+notification_failed:
+	if (rc == 0)
+		rc = resp;
+	return rc;
+}
+
+/**
+ * bif_ctrl_notify_slave_irq() - notify the BIF framework that a slave interrupt
+ *				was received by a BIF controller
+ * @bdev:	BIF controller device pointer
+ *
+ * This function should only be called from a BIF controller driver.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notify_slave_irq(struct bif_ctrl_dev *bdev)
+{
+	struct bif_slave_dev *sdev;
+	int rc = 0, handled = 0;
+
+	if (IS_ERR_OR_NULL(bdev))
+		return -EINVAL;
+
+	mutex_lock(&bif_sdev_list_mutex);
+
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		if (sdev->bdev == bdev && sdev->present) {
+			rc = bif_slave_handle_irq(sdev);
+			if (rc < 0) {
+				pr_err("Could not handle BIF slave irq, rc=%d\n",
+					rc);
+				break;
+			}
+			handled += rc;
+		}
+	}
+
+	mutex_unlock(&bif_sdev_list_mutex);
+
+	if (handled == 0)
+		pr_info("Spurious BIF slave interrupt detected.\n");
+
+	if (rc > 0)
+		rc = 0;
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notify_slave_irq);
+
+/**
+ * bif_ctrl_notify_battery_changed() - notify the BIF framework that a battery
+ *				pack has been inserted or removed
+ * @bdev:	BIF controller device pointer
+ *
+ * This function should only be called from a BIF controller driver.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notify_battery_changed(struct bif_ctrl_dev *bdev)
+{
+	int rc = 0;
+	int present;
+
+	if (IS_ERR_OR_NULL(bdev))
+		return -EINVAL;
+
+	if (bdev->desc->ops->get_battery_presence) {
+		present = bdev->desc->ops->get_battery_presence(bdev);
+		if (present < 0) {
+			pr_err("Could not determine battery presence, rc=%d\n",
+				rc);
+			return rc;
+		}
+
+		if (bdev->battery_present == !!present)
+			return 0;
+
+		bdev->battery_present = present;
+
+		rc = blocking_notifier_call_chain(&bdev->bus_change_notifier,
+			present ? BIF_BUS_EVENT_BATTERY_INSERTED
+				: BIF_BUS_EVENT_BATTERY_REMOVED, bdev);
+		if (rc)
+			pr_err("Call chain noification failed, rc=%d\n", rc);
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notify_battery_changed);
+
+/**
+ * bif_ctrl_signal_battery_changed() - notify the BIF framework that a battery
+ *				pack has been inserted or removed
+ * @ctrl:	BIF controller consumer handle
+ *
+ * This function should only be called by a BIF consumer driver on systems where
+ * the BIF controller driver is unable to determine when a battery is inserted
+ * or removed.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_signal_battery_changed(struct bif_ctrl *ctrl)
+{
+	if (IS_ERR_OR_NULL(ctrl))
+		return -EINVAL;
+
+	return bif_ctrl_notify_battery_changed(ctrl->bdev);
+}
+EXPORT_SYMBOL(bif_ctrl_signal_battery_changed);
+
+/**
+ * bif_ctrl_notifier_register() - register a notifier block to be called when
+ *				a battery pack is inserted or removed
+ * @ctrl:	BIF controller consumer handle
+ *
+ * The value passed into the notifier when it is called is one of
+ * enum bif_bus_event.
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notifier_register(struct bif_ctrl *ctrl, struct notifier_block *nb)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl))
+		return -EINVAL;
+
+	rc = blocking_notifier_chain_register(&ctrl->bdev->bus_change_notifier,
+					      nb);
+	if (rc)
+		pr_err("Notifier registration failed, rc=%d\n", rc);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notifier_register);
+
+/**
+ * bif_ctrl_notifier_unregister() - unregister a battery status change notifier
+ *				block that was previously registered
+ * @ctrl:	BIF controller consumer handle
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_ctrl_notifier_unregister(struct bif_ctrl *ctrl,
+				 struct notifier_block *nb)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl))
+		return -EINVAL;
+
+	rc =
+	    blocking_notifier_chain_unregister(&ctrl->bdev->bus_change_notifier,
+						nb);
+	if (rc)
+		pr_err("Notifier unregistration failed, rc=%d\n", rc);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_notifier_unregister);
+
+/**
+ * bif_get_bus_handle() - returns the BIF controller consumer handle associated
+ *			with a BIF slave handle
+ * @slave:	BIF slave handle
+ *
+ * Note, bif_ctrl_put() should never be called for the pointer output by
+ * bif_get_bus_handle().
+ */
+struct bif_ctrl *bif_get_bus_handle(struct bif_slave *slave)
+{
+	if (IS_ERR_OR_NULL(slave))
+		return ERR_PTR(-EINVAL);
+
+	return &slave->ctrl;
+}
+EXPORT_SYMBOL(bif_get_bus_handle);
+
+/**
+ * bif_ctrl_count() - returns the number of registered BIF controllers
+ */
+int bif_ctrl_count(void)
+{
+	struct bif_ctrl_dev *bdev;
+	int count = 0;
+
+	mutex_lock(&bif_ctrl_list_mutex);
+
+	list_for_each_entry(bdev, &bif_ctrl_list, list) {
+		count++;
+	}
+	mutex_unlock(&bif_ctrl_list_mutex);
+
+	return count;
+}
+EXPORT_SYMBOL(bif_ctrl_count);
+
+/**
+ * bif_ctrl_get_by_id() - get a handle for the id'th BIF controller registered
+ *			in the system
+ * @id:	Arbitrary number associated with the BIF bus in the system
+ *
+ * id must be in the range [0, bif_ctrl_count() - 1].  This function should only
+ * need to be called by a BIF consumer that is unable to link to a given BIF
+ * controller via a device tree binding.
+ *
+ * Returns a BIF controller consumer handle if successful or an ERR_PTR if not.
+ */
+struct bif_ctrl *bif_ctrl_get_by_id(unsigned int id)
+{
+	struct bif_ctrl_dev *bdev;
+	struct bif_ctrl_dev *bdev_found = NULL;
+	struct bif_ctrl *ctrl = ERR_PTR(-ENODEV);
+
+	mutex_lock(&bif_ctrl_list_mutex);
+
+	list_for_each_entry(bdev, &bif_ctrl_list, list) {
+		if (id == 0) {
+			bdev_found = bdev;
+			break;
+		}
+		id--;
+	}
+	mutex_unlock(&bif_ctrl_list_mutex);
+
+	if (bdev_found) {
+		ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+		if (!ctrl) {
+			pr_err("Bus handle allocation failed\n");
+			ctrl = ERR_PTR(-ENOMEM);
+		} else {
+			ctrl->bdev = bdev_found;
+		}
+	}
+
+	return ctrl;
+}
+EXPORT_SYMBOL(bif_ctrl_get_by_id);
+
+/**
+ * bif_ctrl_get() - get a handle for the BIF controller that is linked to the
+ *			consumer device in the device tree
+ * @consumer_dev:	Pointer to the consumer's device
+ *
+ * In order to use this function, the BIF consumer's device must specify the
+ * "qcom,bif-ctrl" property in its device tree node which points to a BIF
+ * controller device node.
+ *
+ * Returns a BIF controller consumer handle if successful or an ERR_PTR if not.
+ * If the BIF controller linked to the consumer device has not yet probed, then
+ * ERR_PTR(-EPROBE_DEFER) is returned.
+ */
+struct bif_ctrl *bif_ctrl_get(struct device *consumer_dev)
+{
+	struct device_node *ctrl_node = NULL;
+	struct bif_ctrl_dev *bdev_found = NULL;
+	struct bif_ctrl *ctrl = ERR_PTR(-EPROBE_DEFER);
+	struct bif_ctrl_dev *bdev = NULL;
+
+	if (!consumer_dev || !consumer_dev->of_node) {
+		pr_err("Invalid device node\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	ctrl_node = of_parse_phandle(consumer_dev->of_node, "qcom,bif-ctrl", 0);
+	if (!ctrl_node) {
+		pr_err("Could not find qcom,bif-ctrl property in %s\n",
+			consumer_dev->of_node->full_name);
+		return ERR_PTR(-ENXIO);
+	}
+
+	mutex_lock(&bif_ctrl_list_mutex);
+	list_for_each_entry(bdev, &bif_ctrl_list, list) {
+		if (bdev->ctrl_dev && bdev->ctrl_dev->of_node == ctrl_node) {
+			bdev_found = bdev;
+			break;
+		}
+	}
+	mutex_unlock(&bif_ctrl_list_mutex);
+
+	if (bdev_found) {
+		ctrl = kzalloc(sizeof(*ctrl), GFP_KERNEL);
+		if (!ctrl) {
+			pr_err("Bus handle allocation failed\n");
+			ctrl = ERR_PTR(-ENOMEM);
+		} else {
+			ctrl->bdev = bdev_found;
+		}
+	}
+
+	return ctrl;
+}
+EXPORT_SYMBOL(bif_ctrl_get);
+
+/**
+ * bif_ctrl_put() - frees a BIF controller handle
+ * @ctrl:	BIF controller consumer handle
+ */
+void bif_ctrl_put(struct bif_ctrl *ctrl)
+{
+	if (!IS_ERR_OR_NULL(ctrl) && ctrl->exclusive_lock)
+		mutex_unlock(&ctrl->bdev->mutex);
+	kfree(ctrl);
+}
+EXPORT_SYMBOL(bif_ctrl_put);
+
+/*
+ * Returns true if all parameters are matched, otherwise false.
+ * function_type and function_version mean that their exists some function in
+ * the slave which has the specified type and subtype.  ctrl == NULL is treated
+ * as a wildcard.
+ */
+static bool bif_slave_match(const struct bif_ctrl *ctrl,
+	struct bif_slave_dev *sdev, const struct bif_match_criteria *criteria)
+{
+	int i, type, version;
+
+	if (ctrl && (ctrl->bdev != sdev->bdev))
+		return false;
+
+	if (!sdev->present
+	    && (!(criteria->match_mask & BIF_MATCH_IGNORE_PRESENCE)
+		|| ((criteria->match_mask & BIF_MATCH_IGNORE_PRESENCE)
+		    && !criteria->ignore_presence)))
+		return false;
+
+	if ((criteria->match_mask & BIF_MATCH_MANUFACTURER_ID)
+	    && sdev->l1_data.manufacturer_id != criteria->manufacturer_id)
+		return false;
+
+	if ((criteria->match_mask & BIF_MATCH_PRODUCT_ID)
+	    && sdev->l1_data.product_id != criteria->product_id)
+		return false;
+
+	if (criteria->match_mask & BIF_MATCH_FUNCTION_TYPE) {
+		if (!sdev->function_directory)
+			return false;
+		for (i = 0; i < sdev->l1_data.length / 4; i++) {
+			type = sdev->function_directory[i].function_type;
+			version = sdev->function_directory[i].function_version;
+			if (type == criteria->function_type &&
+				(version == criteria->function_version
+					|| !(criteria->match_mask
+						& BIF_MATCH_FUNCTION_VERSION)))
+				return true;
+		}
+		return false;
+	}
+
+	return true;
+}
+
+/**
+ * bif_slave_match_count() - returns the number of slaves associated with the
+ *			specified BIF controller which fit the matching
+ *			criteria
+ * @ctrl:		BIF controller consumer handle
+ * @match_criteria:	Matching criteria used to filter slaves
+ */
+int bif_slave_match_count(const struct bif_ctrl *ctrl,
+			const struct bif_match_criteria *match_criteria)
+{
+	struct bif_slave_dev *sdev;
+	int count = 0;
+
+	mutex_lock(&bif_sdev_list_mutex);
+
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		if (bif_slave_match(ctrl, sdev, match_criteria))
+			count++;
+	}
+
+	mutex_unlock(&bif_sdev_list_mutex);
+
+	return count;
+}
+EXPORT_SYMBOL(bif_slave_match_count);
+
+/**
+ * bif_slave_match_get() - get a slave handle for the id'th slave associated
+ *			with the specified BIF controller which fits the
+ *			matching criteria
+ * @ctrl:		BIF controller consumer handle
+ * @id:			Index into the set of matching slaves
+ * @match_criteria:	Matching criteria used to filter slaves
+ *
+ * id must be in the range [0, bif_slave_match_count(ctrl, match_criteria) - 1].
+ *
+ * Returns a BIF slave handle if successful or an ERR_PTR if not.
+ */
+struct bif_slave *bif_slave_match_get(const struct bif_ctrl *ctrl,
+	unsigned int id, const struct bif_match_criteria *match_criteria)
+{
+	struct bif_slave_dev *sdev;
+	struct bif_slave *slave = ERR_PTR(-ENODEV);
+	struct bif_slave_dev *sdev_found = NULL;
+	int count = 0;
+
+	mutex_lock(&bif_sdev_list_mutex);
+
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		if (bif_slave_match(ctrl, sdev, match_criteria))
+			count++;
+		if (count == id + 1) {
+			sdev_found = sdev;
+			break;
+		}
+	}
+
+	mutex_unlock(&bif_sdev_list_mutex);
+
+	if (sdev_found) {
+		slave = kzalloc(sizeof(*slave), GFP_KERNEL);
+		if (!slave) {
+			pr_err("Slave allocation failed\n");
+			slave = ERR_PTR(-ENOMEM);
+		} else {
+			slave->sdev = sdev_found;
+			slave->ctrl.bdev = sdev_found->bdev;
+		}
+	}
+
+	return slave;
+}
+EXPORT_SYMBOL(bif_slave_match_get);
+
+/**
+ * bif_slave_put() - frees a BIF slave handle
+ * @slave:	BIF slave handle
+ */
+void bif_slave_put(struct bif_slave *slave)
+{
+	if (!IS_ERR_OR_NULL(slave) && slave->ctrl.exclusive_lock)
+		mutex_unlock(&slave->sdev->bdev->mutex);
+	kfree(slave);
+}
+EXPORT_SYMBOL(bif_slave_put);
+
+/**
+ * bif_slave_find_function() - get the function pointer and version of a
+ *			BIF function if it is present on the specified slave
+ * @slave:		BIF slave handle
+ * @function:		BIF function to search for inside of the slave
+ * @version:		If the function is found, then 'version' is set to the
+ *			version value of the function
+ * @function_pointer:	If the function is found, then 'function_pointer' is set
+ *			to the BIF slave address of the function
+ *
+ * Returns 0 for success or errno if an error occurred.  If the function is not
+ * found in the slave, then -ENODEV is returned.
+ */
+int bif_slave_find_function(struct bif_slave *slave, u8 function, u8 *version,
+				u16 *function_pointer)
+{
+	int rc = -ENODEV;
+	struct bif_ddb_l2_data *func;
+	int i;
+
+	if (IS_ERR_OR_NULL(slave) || IS_ERR_OR_NULL(version)
+	    || IS_ERR_OR_NULL(function_pointer)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	func = slave->sdev->function_directory;
+
+	for (i = 0; i < slave->sdev->l1_data.length / 4; i++) {
+		if (function == func[i].function_type) {
+			*version = func[i].function_version;
+			*function_pointer = func[i].function_pointer;
+			rc = 0;
+			break;
+		}
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_slave_find_function);
+
+/**
+ * bif_slave_read() - read contiguous memory values from a BIF slave
+ * @slave:	BIF slave handle
+ * @addr:	BIF slave address to begin reading at
+ * @buf:	Buffer to fill with memory values
+ * @len:	Number of byte to read
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_slave_read(struct bif_slave *slave, u16 addr, u8 *buf, int len)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(slave) || IS_ERR_OR_NULL(buf)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	bif_slave_ctrl_lock(slave);
+
+	rc = _bif_slave_read(slave->sdev, addr, buf, len);
+	if (rc)
+		pr_err("BIF slave read failed, rc=%d\n", rc);
+
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_slave_read);
+
+/**
+ * bif_slave_write() - write contiguous memory values to a BIF slave
+ * @slave:	BIF slave handle
+ * @addr:	BIF slave address to begin writing at
+ * @buf:	Buffer containing values to write
+ * @len:	Number of byte to write
+ *
+ * Returns 0 for success or errno if an error occurred.
+ */
+int bif_slave_write(struct bif_slave *slave, u16 addr, u8 *buf, int len)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(slave) || IS_ERR_OR_NULL(buf)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	bif_slave_ctrl_lock(slave);
+
+	rc = _bif_slave_write(slave->sdev, addr, buf, len);
+	if (rc)
+		pr_err("BIF slave write failed, rc=%d\n", rc);
+
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_slave_write);
+
+/**
+ * bif_slave_is_present() - check if a slave is currently physically present
+ *		in the system
+ * @slave:	BIF slave handle
+ *
+ * Returns 1 if the slave is present, 0 if the slave is not present, or errno
+ * if an error occurred.
+ *
+ * This function can be used by BIF consumer drivers to check if their slave
+ * handles are still meaningful after battery reinsertion.
+ */
+int bif_slave_is_present(struct bif_slave *slave)
+{
+	if (IS_ERR_OR_NULL(slave)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	return slave->sdev->present;
+}
+EXPORT_SYMBOL(bif_slave_is_present);
+
+/**
+ * bif_slave_is_selected() - check if a slave is currently selected on the BIF
+ *		bus
+ * @slave:	BIF slave handle
+ *
+ * Returns 1 if the slave is selected, 0 if the slave is not selected, or errno
+ * if an error occurred.
+ *
+ * This function should not be required under normal circumstances since the
+ * bif-core framework ensures that slaves are always selected when needed.
+ * It would be most useful when used as a helper in conjunction with
+ * bif_ctrl_bus_lock() and the raw transaction functions.
+ */
+int bif_slave_is_selected(struct bif_slave *slave)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(slave)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	if (slave->sdev->bdev->selected_sdev != slave->sdev)
+		return false;
+
+	bif_slave_ctrl_lock(slave);
+	rc = bif_is_slave_selected(slave->sdev->bdev);
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_slave_is_selected);
+
+/**
+ * bif_slave_select() - select a slave on the BIF bus
+ * @slave:	BIF slave handle
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should not be required under normal circumstances since the
+ * bif-core framework ensures that slaves are always selected when needed.
+ * It would be most useful when used as a helper in conjunction with
+ * bif_ctrl_bus_lock() and the raw transaction functions.
+ */
+int bif_slave_select(struct bif_slave *slave)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(slave)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	bif_slave_ctrl_lock(slave);
+	slave->sdev->bdev->selected_sdev = NULL;
+	rc = bif_select_slave(slave->sdev);
+	bif_slave_ctrl_unlock(slave);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_slave_select);
+
+/**
+ * bif_ctrl_raw_transaction() - perform a raw BIF transaction on the bus which
+ *			expects no slave response
+ * @ctrl:		BIF controller consumer handle
+ * @transaction:	BIF transaction to carry out.  This should be one of the
+ *			values in enum bif_transaction.
+ * @data:		8-bit data to use in the transaction.  The meaning of
+ *			this data depends upon the transaction that is to be
+ *			performed.
+ *
+ * When performing a bus command (BC) transaction, values in enum
+ * bif_bus_command may be used for the data parameter.  Additional manufacturer
+ * specific values may also be used in a BC transaction.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should only need to be used when BIF transactions are required
+ * that are not handled by the bif-core directly.
+ */
+int bif_ctrl_raw_transaction(struct bif_ctrl *ctrl, int transaction, u8 data)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	bif_ctrl_lock(ctrl);
+
+	rc = ctrl->bdev->desc->ops->bus_transaction(ctrl->bdev, transaction,
+							data);
+	if (rc)
+		pr_err("BIF bus transaction failed, rc=%d\n", rc);
+
+	bif_ctrl_unlock(ctrl);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_raw_transaction);
+
+/**
+ * bif_ctrl_raw_transaction_read() - perform a raw BIF transaction on the bus
+ *			which expects an RD or TACK slave response word
+ * @ctrl:		BIF controller consumer handle
+ * @transaction:	BIF transaction to carry out.  This should be one of the
+ *			values in enum bif_transaction.
+ * @data:		8-bit data to use in the transaction.  The meaning of
+ *			this data depends upon the transaction that is to be
+ *			performed.
+ * @response:		Pointer to an integer which is filled with the 11-bit
+ *			slave response word upon success.  The 11-bit format is
+ *			(MSB to LSB) BCF, ACK, EOT, D7-D0.
+ *
+ * When performing a bus command (BC) transaction, values in enum
+ * bif_bus_command may be used for the data parameter.  Additional manufacturer
+ * specific values may also be used in a BC transaction.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should only need to be used when BIF transactions are required
+ * that are not handled by the bif-core directly.
+ */
+int bif_ctrl_raw_transaction_read(struct bif_ctrl *ctrl, int transaction,
+					u8 data, int *response)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl) || IS_ERR_OR_NULL(response)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	bif_ctrl_lock(ctrl);
+
+	rc = ctrl->bdev->desc->ops->bus_transaction_read(ctrl->bdev,
+					transaction, data, response);
+	if (rc)
+		pr_err("BIF bus transaction failed, rc=%d\n", rc);
+
+	bif_ctrl_unlock(ctrl);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_raw_transaction_read);
+
+/**
+ * bif_ctrl_raw_transaction_query() - perform a raw BIF transaction on the bus
+ *			which expects a BQ slave response
+ * @ctrl:		BIF controller consumer handle
+ * @transaction:	BIF transaction to carry out.  This should be one of the
+ *			values in enum bif_transaction.
+ * @data:		8-bit data to use in the transaction.  The meaning of
+ *			this data depends upon the transaction that is to be
+ *			performed.
+ * @query_response:	Pointer to boolean which is set to true if a BQ pulse
+ *			is receieved, or false if no BQ pulse is received before
+ *			timing out.
+ *
+ * When performing a bus command (BC) transaction, values in enum
+ * bif_bus_command may be used for the data parameter.  Additional manufacturer
+ * specific values may also be used in a BC transaction.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ *
+ * This function should only need to be used when BIF transactions are required
+ * that are not handled by the bif-core directly.
+ */
+int bif_ctrl_raw_transaction_query(struct bif_ctrl *ctrl, int transaction,
+		u8 data, bool *query_response)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl) || IS_ERR_OR_NULL(query_response)) {
+		pr_err("Invalid pointer input.\n");
+		return -EINVAL;
+	}
+
+	bif_ctrl_lock(ctrl);
+
+	rc = ctrl->bdev->desc->ops->bus_transaction_query(ctrl->bdev,
+					transaction, data, query_response);
+	if (rc)
+		pr_err("BIF bus transaction failed, rc=%d\n", rc);
+
+	bif_ctrl_unlock(ctrl);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_raw_transaction_query);
+
+/**
+ * bif_ctrl_bus_lock() - lock the BIF bus of a controller for exclusive access
+ * @ctrl:	BIF controller consumer handle
+ *
+ * This function should only need to be called in circumstances where a BIF
+ * consumer is issuing special BIF bus commands that have strict ordering
+ * requirements.
+ */
+void bif_ctrl_bus_lock(struct bif_ctrl *ctrl)
+{
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid controller handle.\n");
+		return;
+	}
+
+	if (ctrl->exclusive_lock) {
+		pr_err("BIF bus exclusive lock already held\n");
+		return;
+	}
+
+	mutex_lock(&ctrl->bdev->mutex);
+	ctrl->exclusive_lock = true;
+	bif_cancel_irq_mode_work(ctrl->bdev);
+}
+EXPORT_SYMBOL(bif_ctrl_bus_lock);
+
+/**
+ * bif_ctrl_bus_unlock() - lock the BIF bus of a controller that was previously
+ *		locked for exclusive access
+ * @ctrl:	BIF controller consumer handle
+ *
+ * This function must only be called after first calling bif_ctrl_bus_lock().
+ */
+void bif_ctrl_bus_unlock(struct bif_ctrl *ctrl)
+{
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid controller handle.\n");
+		return;
+	}
+
+	if (!ctrl->exclusive_lock) {
+		pr_err("BIF bus exclusive lock not already held\n");
+		return;
+	}
+
+	ctrl->exclusive_lock = false;
+	bif_schedule_irq_mode_work(ctrl->bdev);
+	mutex_unlock(&ctrl->bdev->mutex);
+}
+EXPORT_SYMBOL(bif_ctrl_bus_unlock);
+
+/**
+ * bif_ctrl_measure_rid() - measure the battery pack Rid pull-down resistance
+ *		in ohms
+ * @ctrl:	BIF controller consumer handle
+ *
+ * Returns the resistance of the Rid resistor in ohms if successful or errno
+ * if an error occurred.
+ */
+int bif_ctrl_measure_rid(struct bif_ctrl *ctrl)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid controller handle.\n");
+		return -ENODEV;
+	}
+
+	if (!ctrl->bdev->desc->ops->get_battery_rid) {
+		pr_err("Cannot measure Rid.\n");
+		return -ENXIO;
+	}
+
+	bif_ctrl_lock(ctrl);
+
+	rc = ctrl->bdev->desc->ops->get_battery_rid(ctrl->bdev);
+	if (rc < 0)
+		pr_err("Error during Rid measurement, rc=%d\n", rc);
+
+	bif_ctrl_unlock(ctrl);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_measure_rid);
+
+/**
+ * bif_ctrl_get_bus_period() - get the BIF bus period (tau_bif) in nanoseconds
+ * @ctrl:	BIF controller consumer handle
+ *
+ * Returns the currently configured bus period in nanoseconds if successful or
+ * errno if an error occurred.
+ */
+int bif_ctrl_get_bus_period(struct bif_ctrl *ctrl)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid controller handle.\n");
+		return -ENODEV;
+	}
+
+	if (!ctrl->bdev->desc->ops->get_bus_period) {
+		pr_err("Cannot get the BIF bus period.\n");
+		return -ENXIO;
+	}
+
+	rc = ctrl->bdev->desc->ops->get_bus_period(ctrl->bdev);
+	if (rc < 0)
+		pr_err("Error during bus period retrieval, rc=%d\n", rc);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_get_bus_period);
+
+/**
+ * bif_ctrl_set_bus_period() - set the BIF bus period (tau_bif) in nanoseconds
+ * @ctrl:	BIF controller consumer handle
+ * @period_ns:	BIF bus period in nanoseconds to use
+ *
+ * If the exact period is not supported by the BIF controller hardware, then the
+ * next larger supported period will be used.
+ *
+ * Returns 0 on success or errno if an error occurred.
+ */
+int bif_ctrl_set_bus_period(struct bif_ctrl *ctrl, int period_ns)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid controller handle.\n");
+		return -ENODEV;
+	}
+
+	if (!ctrl->bdev->desc->ops->set_bus_period) {
+		pr_err("Cannot set the BIF bus period.\n");
+		return -ENXIO;
+	}
+
+	bif_ctrl_lock(ctrl);
+	rc = ctrl->bdev->desc->ops->set_bus_period(ctrl->bdev, period_ns);
+	if (rc)
+		pr_err("Error during bus period configuration, rc=%d\n", rc);
+	bif_ctrl_unlock(ctrl);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_set_bus_period);
+
+/**
+ * bif_ctrl_get_bus_state() - get the current state of the BIF bus
+ * @ctrl:	BIF controller consumer handle
+ *
+ * Returns a bus state from enum bif_bus_state if successful or errno if an
+ * error occurred.
+ */
+int bif_ctrl_get_bus_state(struct bif_ctrl *ctrl)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid controller handle.\n");
+		return -ENODEV;
+	}
+
+	rc = ctrl->bdev->desc->ops->get_bus_state(ctrl->bdev);
+	if (rc < 0)
+		pr_err("Error during bus state retrieval, rc=%d\n", rc);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_get_bus_state);
+
+/**
+ * bif_ctrl_set_bus_state() - set the state of the BIF bus
+ * @ctrl:	BIF controller consumer handle
+ * @state:	State for the BIF bus to enter
+ *
+ * Returns 0 on success or errno if an error occurred.
+ */
+int bif_ctrl_set_bus_state(struct bif_ctrl *ctrl, enum bif_bus_state state)
+{
+	int rc;
+
+	if (IS_ERR_OR_NULL(ctrl)) {
+		pr_err("Invalid controller handle.\n");
+		return -ENODEV;
+	}
+
+	bif_ctrl_lock(ctrl);
+
+	rc = ctrl->bdev->desc->ops->set_bus_state(ctrl->bdev, state);
+	if (rc < 0)
+		pr_err("Error during bus state configuration, rc=%d\n", rc);
+
+	/*
+	 * Uncache the selected slave if the new bus state results in the slave
+	 * becoming unselected.
+	 */
+	if (state == BIF_BUS_STATE_MASTER_DISABLED
+	    || state == BIF_BUS_STATE_POWER_DOWN
+	    || state == BIF_BUS_STATE_STANDBY)
+		ctrl->bdev->selected_sdev = NULL;
+
+	bif_ctrl_unlock(ctrl);
+
+	return rc;
+}
+EXPORT_SYMBOL(bif_ctrl_set_bus_state);
+
+/*
+ * Check if the specified function is a protocol function and if it is, then
+ * instantiate protocol function data for the slave.
+ */
+static int bif_initialize_protocol_function(struct bif_slave_dev *sdev,
+		struct bif_ddb_l2_data *func)
+{
+	int rc = 0;
+	u8 buf[4];
+
+	/* Ensure that this is a protocol function. */
+	if (func->function_type != BIF_FUNC_PROTOCOL)
+		return 0;
+
+	if (sdev->protocol_function) {
+		pr_err("Duplicate protocol function found for BIF slave; DEV_ADR=0x%02X\n",
+			sdev->slave_addr);
+		return -EPERM;
+	}
+
+	sdev->protocol_function = kzalloc(sizeof(struct bif_protocol_function),
+						GFP_KERNEL);
+	if (!sdev->protocol_function) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	rc = _bif_slave_read(sdev, func->function_pointer, buf, 4);
+	if (rc) {
+		pr_err("Protocol function data read failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	sdev->protocol_function->protocol_pointer  = buf[0] << 8 | buf[1];
+	sdev->protocol_function->device_id_pointer = buf[2] << 8 | buf[3];
+	sdev->protocol_function->l2_entry = func;
+
+	rc = _bif_slave_read(sdev, sdev->protocol_function->device_id_pointer,
+		sdev->protocol_function->device_id, BIF_DEVICE_ID_BYTE_LENGTH);
+	if (rc) {
+		pr_err("Device ID read failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	/* Check if this slave does not have a UID value stored. */
+	if (sdev->unique_id_bits_known == 0) {
+		sdev->unique_id_bits_known = BIF_UNIQUE_ID_BIT_LENGTH;
+		/* Fill in UID using manufacturer ID and device ID. */
+		sdev->unique_id[0] = sdev->l1_data.manufacturer_id >> 8;
+		sdev->unique_id[1] = sdev->l1_data.manufacturer_id;
+		memcpy(&sdev->unique_id[2],
+			sdev->protocol_function->device_id,
+			BIF_DEVICE_ID_BYTE_LENGTH);
+	}
+
+	return rc;
+}
+
+/*
+ * Check if the specified function is a slave control function and if it is,
+ * then instantiate slave control function data for the slave.
+ */
+static int bif_initialize_slave_control_function(struct bif_slave_dev *sdev,
+		struct bif_ddb_l2_data *func)
+{
+	int rc = 0;
+	int i;
+	u8 buf[3];
+
+	/* Ensure that this is a slave control function. */
+	if (func->function_type != BIF_FUNC_SLAVE_CONTROL)
+		return 0;
+
+	if (sdev->slave_ctrl_function) {
+		pr_err("Duplicate slave control function found for BIF slave; DEV_ADR=0x%02X\n",
+			sdev->slave_addr);
+		return -EPERM;
+	}
+
+	sdev->slave_ctrl_function
+		= kzalloc(sizeof(struct bif_protocol_function), GFP_KERNEL);
+	if (!sdev->slave_ctrl_function) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	rc = _bif_slave_read(sdev, func->function_pointer, buf, 3);
+	if (rc) {
+		pr_err("Slave control function data read failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	sdev->slave_ctrl_function->slave_ctrl_pointer = buf[0] << 8 | buf[1];
+	sdev->slave_ctrl_function->task_count
+		= buf[2] * SLAVE_CTRL_TASKS_PER_SET;
+	sdev->slave_ctrl_function->l2_entry = func;
+
+	if (sdev->slave_ctrl_function->task_count > 0) {
+		sdev->slave_ctrl_function->irq_notifier_list =
+			kzalloc(sizeof(struct blocking_notifier_head)
+			    * sdev->slave_ctrl_function->task_count,
+			    GFP_KERNEL);
+		if (!sdev->slave_ctrl_function->irq_notifier_list) {
+			pr_err("out of memory\n");
+			kfree(sdev->slave_ctrl_function);
+			return -ENOMEM;
+		}
+
+		for (i = 0; i < sdev->slave_ctrl_function->task_count; i++) {
+			BLOCKING_INIT_NOTIFIER_HEAD(
+			    &sdev->slave_ctrl_function->irq_notifier_list[i]);
+		}
+	}
+
+	return rc;
+}
+
+/**
+ * bif_crc_ccitt() - calculate the CRC-CCITT CRC value of the data specified
+ * @buffer:	Data to calculate the CRC of
+ * @len:	Length of the data buffer in bytes
+ *
+ * MIPI-BIF specifies the usage of CRC-CCITT for BIF data objects.  This
+ * function performs the CRC calculation while taking into account the bit
+ * ordering used by BIF.
+ */
+u16 bif_crc_ccitt(const u8 *buffer, unsigned int len)
+{
+	u16 crc = 0xFFFF;
+
+	while (len--) {
+		crc = crc_ccitt_byte(crc, bitrev8(*buffer));
+		buffer++;
+	}
+	return bitrev16(crc);
+}
+EXPORT_SYMBOL(bif_crc_ccitt);
+
+static u16 bif_object_crc_ccitt(const struct bif_object *object)
+{
+	u16 crc = 0xFFFF;
+	int i;
+
+	crc = crc_ccitt_byte(crc, bitrev8(object->type));
+	crc = crc_ccitt_byte(crc, bitrev8(object->version));
+	crc = crc_ccitt_byte(crc, bitrev8(object->manufacturer_id >> 8));
+	crc = crc_ccitt_byte(crc, bitrev8(object->manufacturer_id));
+	crc = crc_ccitt_byte(crc, bitrev8(object->length >> 8));
+	crc = crc_ccitt_byte(crc, bitrev8(object->length));
+
+	for (i = 0; i < object->length - 8; i++)
+		crc = crc_ccitt_byte(crc, bitrev8(object->data[i]));
+
+	return bitrev16(crc);
+}
+
+/*
+ * Check if the specified function is an NVM function and if it is, then
+ * instantiate NVM function data for the slave and read all objects.
+ */
+static int bif_initialize_nvm_function(struct bif_slave_dev *sdev,
+		struct bif_ddb_l2_data *func)
+{
+	int rc = 0;
+	int data_len;
+	u8 buf[8], object_type;
+	struct bif_object *object;
+	struct bif_object *temp;
+	u16 addr;
+	u16 crc;
+
+	/* Ensure that this is an NVM function. */
+	if (func->function_type != BIF_FUNC_NVM)
+		return 0;
+
+	if (sdev->nvm_function) {
+		pr_err("Duplicate NVM function found for BIF slave; DEV_ADR=0x%02X\n",
+			sdev->slave_addr);
+		return -EPERM;
+	}
+
+	sdev->nvm_function
+		= kzalloc(sizeof(*sdev->nvm_function), GFP_KERNEL);
+	if (!sdev->nvm_function) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	rc = _bif_slave_read(sdev, func->function_pointer, buf, 8);
+	if (rc) {
+		pr_err("NVM function data read failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	sdev->nvm_function->nvm_pointer		= buf[0] << 8 | buf[1];
+	sdev->nvm_function->slave_control_channel	= buf[2];
+	sdev->nvm_function->write_buffer_size		= buf[3];
+	sdev->nvm_function->nvm_base_address		= buf[4] << 8 | buf[5];
+	sdev->nvm_function->nvm_size			= buf[6] << 8 | buf[7];
+
+	INIT_LIST_HEAD(&sdev->nvm_function->object_list);
+
+	/* Read object list */
+	addr = sdev->nvm_function->nvm_base_address;
+	rc = _bif_slave_read(sdev, addr, &object_type, 1);
+	if (rc) {
+		pr_err("Slave memory read failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	/* Object type == 0x00 corresponds to the end of the object list. */
+	while (object_type != 0x00) {
+		object = kzalloc(sizeof(*object), GFP_KERNEL);
+		if (!object) {
+			pr_err("out of memory\n");
+			rc = -ENOMEM;
+			goto free_data;
+		}
+		list_add_tail(&object->list, &sdev->nvm_function->object_list);
+
+		rc = _bif_slave_read(sdev, addr + 1, buf + 1, 5);
+		if (rc) {
+			pr_err("Slave memory read of object header failed; addr=0x%04X, len=%d, rc=%d\n",
+				addr + 1, 5, rc);
+			goto free_data;
+		}
+
+		object->addr		= addr;
+		object->type		= object_type;
+		object->version		= buf[1];
+		object->manufacturer_id	= buf[2] << 8 | buf[3];
+		object->length		= buf[4] << 8 | buf[5];
+
+		if ((object->addr + object->length)
+		    > (sdev->nvm_function->nvm_base_address
+				+ sdev->nvm_function->nvm_size)) {
+			pr_warn("warning: BIF slave object is not formatted correctly; NVM base=0x%04X, NVM len=%d, object addr=0x%04X, object len=%d\n",
+				sdev->nvm_function->nvm_base_address,
+				sdev->nvm_function->nvm_size,
+				object->addr,
+				object->length);
+			/* Limit object size to remaining NVM size. */
+			object->length = sdev->nvm_function->nvm_size
+				+ sdev->nvm_function->nvm_base_address
+				- object->addr;
+		}
+
+		/* Object header + CRC takes up 8 bytes. */
+		data_len = object->length - 8;
+		object->data = kmalloc(data_len, GFP_KERNEL);
+		if (!object->data) {
+			pr_err("out of memory\n");
+			rc = -ENOMEM;
+			goto free_data;
+		}
+
+		rc = _bif_slave_read(sdev, addr + 6, object->data, data_len);
+		if (rc) {
+			pr_err("Slave memory read of object data failed; addr=0x%04X, len=%d, rc=%d\n",
+				addr + 6, data_len, rc);
+			goto free_data;
+		}
+
+		rc = _bif_slave_read(sdev, addr + 6 + data_len, buf, 3);
+		if (rc) {
+			pr_err("Slave memory read of object CRC failed; addr=0x%04X, len=%d, rc=%d\n",
+				addr + 6 + data_len, 3, rc);
+			goto free_data;
+		}
+
+		object->crc = buf[0] << 8 | buf[1];
+		object_type = buf[2];
+		sdev->nvm_function->object_count++;
+
+		crc = bif_object_crc_ccitt(object);
+		if (crc != object->crc)
+			pr_info("BIF object at addr=0x%04X has invalid CRC; crc calc=0x%04X, crc exp=0x%04X\n",
+				object->addr, crc, object->crc);
+
+		addr += object->length;
+	}
+
+	return rc;
+
+free_data:
+	list_for_each_entry_safe(object, temp,
+				&sdev->nvm_function->object_list, list) {
+		list_del(&object->list);
+		kfree(object->data);
+		kfree(object);
+	}
+	kfree(sdev->nvm_function);
+	sdev->nvm_function = NULL;
+	return rc;
+}
+
+static int bif_parse_slave_data(struct bif_slave_dev *sdev)
+{
+	int rc = 0;
+	u8 buf[10];
+	u8 *func_buf;
+	struct bif_ddb_l2_data *func;
+	int function_count, i;
+
+	rc = _bif_slave_read(sdev, BIF_DDB_L1_BASE_ADDR, buf, 10);
+	if (rc) {
+		pr_err("DDB L1 data read failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	sdev->l1_data.revision		= buf[0];
+	sdev->l1_data.level		= buf[1];
+	sdev->l1_data.device_class	= buf[2] << 8 | buf[3];
+	sdev->l1_data.manufacturer_id	= buf[4] << 8 | buf[5];
+	sdev->l1_data.product_id	= buf[6] << 8 | buf[7];
+	sdev->l1_data.length		= buf[8] << 8 | buf[9];
+
+	function_count = sdev->l1_data.length / 4;
+	if (sdev->l1_data.length % 4) {
+		pr_err("Function directory length=%d is invalid\n",
+				sdev->l1_data.length);
+		return -EPROTO;
+	}
+
+	/* No DDB L2 function directory */
+	if (function_count == 0)
+		return 0;
+
+	func_buf = kmalloc(sdev->l1_data.length, GFP_KERNEL);
+	if (!func_buf) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	sdev->function_directory = kzalloc(
+		function_count * sizeof(struct bif_ddb_l2_data), GFP_KERNEL);
+	if (!sdev->function_directory) {
+		pr_err("out of memory\n");
+		return -ENOMEM;
+	}
+
+	rc = _bif_slave_read(sdev, BIF_DDB_L2_BASE_ADDR, func_buf,
+				sdev->l1_data.length);
+	if (rc) {
+		pr_err("DDB L2 data read failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	for (i = 0; i < function_count; i++) {
+		func = &sdev->function_directory[i];
+		func->function_type	= func_buf[i * 4];
+		func->function_version	= func_buf[i * 4 + 1];
+		func->function_pointer	= func_buf[i * 4 + 2] << 8
+					  | func_buf[i * 4 + 3];
+		rc = bif_initialize_protocol_function(sdev, func);
+		if (rc)
+			goto done;
+		rc = bif_initialize_slave_control_function(sdev, func);
+		if (rc)
+			goto done;
+		rc = bif_initialize_nvm_function(sdev, func);
+		if (rc)
+			goto done;
+	}
+done:
+	kfree(func_buf);
+	return rc;
+}
+
+static int bif_add_secondary_slaves(struct bif_slave_dev *primary_slave)
+{
+	int rc = 0;
+	int data_len, i;
+	u16 crc;
+	struct bif_slave_dev *sdev;
+	struct bif_object *object;
+
+	list_for_each_entry(object, &primary_slave->nvm_function->object_list,
+				list) {
+		if (object->type != BIF_OBJ_SEC_SLAVE)
+			continue;
+
+		data_len = object->length - 8;
+		if (data_len % BIF_UNIQUE_ID_BYTE_LENGTH) {
+			pr_info("Invalid secondary slave object found, addr=0x%04X, data len=%d\n",
+				object->addr, data_len);
+			continue;
+		}
+
+		crc = bif_object_crc_ccitt(object);
+		if (crc != object->crc) {
+			pr_info("BIF object at addr=0x%04X has invalid CRC; crc calc=0x%04X, crc exp=0x%04X\n",
+				object->addr, crc, object->crc);
+			continue;
+		}
+
+		for (i = 0; i < data_len / BIF_UNIQUE_ID_BYTE_LENGTH; i++) {
+			sdev = bif_add_slave(primary_slave->bdev);
+			if (IS_ERR(sdev)) {
+				rc = PTR_ERR(sdev);
+				pr_err("bif_add_slave failed, rc=%d\n", rc);
+				return rc;
+			}
+			memcpy(sdev->unique_id,
+				&object->data[i * BIF_UNIQUE_ID_BYTE_LENGTH],
+				BIF_UNIQUE_ID_BYTE_LENGTH);
+			sdev->unique_id_bits_known = BIF_UNIQUE_ID_BIT_LENGTH;
+
+			rc = bif_select_slave(sdev);
+			if (rc) {
+				pr_err("Could not select slave, rc=%d\n", rc);
+				goto free_slave;
+			}
+
+			rc = bif_is_slave_selected(sdev->bdev);
+			if (rc < 0) {
+				pr_err("Transaction failed, rc=%d\n", rc);
+				goto free_slave;
+			} else if (rc == 1) {
+				sdev->present = true;
+				sdev->bdev->selected_sdev = sdev;
+			} else {
+				sdev->present = false;
+				sdev->bdev->selected_sdev = NULL;
+			}
+		}
+	}
+
+	return rc;
+
+free_slave:
+	bif_remove_slave(sdev);
+	return rc;
+}
+
+/*
+ * Performs UID search to identify all slaves attached to the bus. Assumes that
+ * all necessary locks are held.
+ */
+static int bif_perform_uid_search(struct bif_ctrl_dev *bdev)
+{
+	struct bif_slave_dev *sdev;
+	struct bif_slave_dev *new_slave;
+	bool resp[2], resp_dilc;
+	int i;
+	int rc = 0;
+	u8 cmd_probe[2] = {BIF_CMD_DIP0, BIF_CMD_DIP1};
+	u8 cmd_enter[2] = {BIF_CMD_DIE0, BIF_CMD_DIE1};
+
+	/*
+	 * Iterate over all partially known UIDs adding new ones as they are
+	 * found.
+	 */
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		/* Skip slaves with fully known UIDs. */
+		if (sdev->unique_id_bits_known == BIF_UNIQUE_ID_BIT_LENGTH
+		    || sdev->bdev != bdev)
+			continue;
+
+		/* Begin a new UID search. */
+		rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_BC,
+							BIF_CMD_DISS);
+		if (rc) {
+			pr_err("bus_transaction failed, rc=%d\n", rc);
+			return rc;
+		}
+
+		/* Step through all known UID bits (MSB to LSB). */
+		for (i = 0; i < sdev->unique_id_bits_known; i++) {
+			rc = bdev->desc->ops->bus_transaction(bdev,
+				BIF_TRANS_BC,
+				cmd_enter[get_uid_bit(sdev->unique_id, i)]);
+			if (rc) {
+				pr_err("bus_transaction failed, rc=%d\n", rc);
+				return rc;
+			}
+		}
+
+		/* Step through unknown UID bits. */
+		for (i = sdev->unique_id_bits_known;
+				i < BIF_UNIQUE_ID_BIT_LENGTH; i++) {
+			rc = bdev->desc->ops->bus_transaction_query(bdev,
+				BIF_TRANS_BC, cmd_probe[0], &resp[0]);
+			if (rc) {
+				pr_err("bus_transaction failed, rc=%d\n", rc);
+				return rc;
+			}
+
+			rc = bdev->desc->ops->bus_transaction_query(bdev,
+				BIF_TRANS_BC, cmd_probe[1], &resp[1]);
+			if (rc) {
+				pr_err("bus_transaction failed, rc=%d\n", rc);
+				return rc;
+			}
+
+			if (resp[0] && resp[1]) {
+				/* Create an entry for the new UID branch. */
+				new_slave = bif_add_slave(bdev);
+				if (IS_ERR(new_slave)) {
+					rc = PTR_ERR(sdev);
+					pr_err("bif_add_slave failed, rc=%d\n",
+						rc);
+					return rc;
+				}
+				memcpy(new_slave->unique_id, sdev->unique_id,
+					BIF_UNIQUE_ID_BYTE_LENGTH);
+				new_slave->bdev = sdev->bdev;
+
+				set_uid_bit(sdev->unique_id, i, 0);
+				sdev->unique_id_bits_known = i + 1;
+
+				set_uid_bit(new_slave->unique_id, i, 1);
+				new_slave->unique_id_bits_known = i + 1;
+			} else if (resp[0]) {
+				set_uid_bit(sdev->unique_id, i, 0);
+				sdev->unique_id_bits_known = i + 1;
+			} else if (resp[1]) {
+				set_uid_bit(sdev->unique_id, i, 1);
+				sdev->unique_id_bits_known = i + 1;
+			} else {
+				pr_debug("no bus query response received\n");
+				rc = -ENXIO;
+				return rc;
+			}
+
+			rc = bdev->desc->ops->bus_transaction(bdev,
+				BIF_TRANS_BC, cmd_enter[resp[0] ? 0 : 1]);
+			if (rc) {
+				pr_err("bus_transaction failed, rc=%d\n", rc);
+				return rc;
+			}
+		}
+
+		rc = bdev->desc->ops->bus_transaction_query(bdev,
+			BIF_TRANS_BC, BIF_CMD_DILC, &resp_dilc);
+		if (rc) {
+			pr_err("bus_transaction failed, rc=%d\n", rc);
+			return rc;
+		}
+
+		if (resp_dilc) {
+			sdev->present = true;
+			sdev->bdev->selected_sdev = sdev;
+			rc = bif_parse_slave_data(sdev);
+		} else {
+			pr_err("Slave failed to respond to DILC bus command; its UID is thus unverified.\n");
+			sdev->unique_id_bits_known = 0;
+			rc = -ENXIO;
+			return rc;
+		}
+	}
+
+	return rc;
+}
+
+/*
+ * Removes slaves from the bif_sdev_list which have the same UID as previous
+ * slaves in the list.
+ */
+static int bif_remove_duplicate_slaves(struct bif_ctrl_dev *bdev)
+{
+	struct bif_slave_dev *sdev;
+	struct bif_slave_dev *last_slave;
+	struct bif_slave_dev *temp;
+
+	list_for_each_entry_safe(last_slave, temp, &bif_sdev_list, list) {
+		list_for_each_entry(sdev, &bif_sdev_list, list) {
+			if (last_slave == sdev) {
+				break;
+			} else if (memcmp(last_slave->unique_id,
+					sdev->unique_id,
+					BIF_UNIQUE_ID_BYTE_LENGTH) == 0) {
+				bif_remove_slave(last_slave);
+				break;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int bif_add_all_slaves(struct bif_ctrl_dev *bdev)
+{
+	struct bif_slave_dev *sdev;
+	int rc = 0;
+	int i;
+	bool has_slave = false, is_primary_slave = false;
+
+	mutex_lock(&bif_sdev_list_mutex);
+	mutex_lock(&bdev->mutex);
+
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		if (sdev->bdev == bdev) {
+			has_slave = true;
+			break;
+		}
+	}
+
+	if (!has_slave) {
+		/* Create a single empty slave to start the search algorithm. */
+		sdev = bif_add_slave(bdev);
+		if (IS_ERR(sdev)) {
+			rc = PTR_ERR(sdev);
+			pr_err("bif_add_slave failed, rc=%d\n", rc);
+			goto out;
+		}
+
+		for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+			/* Attempt to select primary slave in battery pack. */
+			rc = bdev->desc->ops->bus_transaction(bdev,
+				BIF_TRANS_SDA, BIF_PRIMARY_SLAVE_DEV_ADR);
+			if (rc == 0)
+				break;
+		}
+		if (rc) {
+			pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+			goto out;
+		}
+
+		/* Check if a slave is selected. */
+		rc = bif_is_slave_selected(bdev);
+		if (rc < 0) {
+			pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+			goto out;
+		} else {
+			is_primary_slave = rc;
+		}
+	}
+
+	if (is_primary_slave) {
+		pr_debug("Using primary slave at DEV_ADR==0x%02X\n",
+			BIF_PRIMARY_SLAVE_DEV_ADR);
+		sdev->bdev->selected_sdev = sdev;
+		sdev->present = true;
+		sdev->slave_addr = BIF_PRIMARY_SLAVE_DEV_ADR;
+		rc = bif_parse_slave_data(sdev);
+		if (rc) {
+			pr_err("Failed to parse primary slave data, rc=%d\n",
+				rc);
+			goto out;
+		}
+		rc = bif_add_secondary_slaves(sdev);
+		if (rc) {
+			pr_err("Failed to add secondary slaves, rc=%d\n", rc);
+			goto out;
+		}
+	} else {
+		pr_debug("Falling back on full UID search.\n");
+		for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+			rc = bif_perform_uid_search(bdev);
+			if (rc == 0)
+				break;
+		}
+		if (rc) {
+			pr_debug("BIF UID search failed, rc=%d\n", rc);
+			goto out;
+		}
+	}
+
+	bif_remove_duplicate_slaves(bdev);
+
+	mutex_unlock(&bdev->mutex);
+	mutex_unlock(&bif_sdev_list_mutex);
+
+	return rc;
+
+out:
+	mutex_unlock(&bdev->mutex);
+	mutex_unlock(&bif_sdev_list_mutex);
+	pr_debug("BIF slave search failed, rc=%d\n", rc);
+	return rc;
+}
+
+static int bif_add_known_slave(struct bif_ctrl_dev *bdev, u8 slave_addr)
+{
+	struct bif_slave_dev *sdev;
+	int rc = 0;
+	int i;
+
+	for (i = 0; i < BIF_TRANSACTION_RETRY_COUNT; i++) {
+		/* Attempt to select the slave. */
+		rc = bdev->desc->ops->bus_transaction(bdev, BIF_TRANS_SDA,
+							slave_addr);
+		if (rc == 0)
+			break;
+	}
+	if (rc) {
+		pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	/* Check if a slave is selected. */
+	rc = bif_is_slave_selected(bdev);
+	if (rc < 0) {
+		pr_err("BIF bus_transaction failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	sdev = bif_add_slave(bdev);
+	if (IS_ERR(sdev)) {
+		rc = PTR_ERR(sdev);
+		pr_err("bif_add_slave failed, rc=%d\n", rc);
+		return rc;
+	}
+
+	sdev->bdev->selected_sdev = sdev;
+	sdev->present = true;
+	sdev->slave_addr = slave_addr;
+	rc = bif_parse_slave_data(sdev);
+	if (rc) {
+		pr_err("Failed to parse slave data, addr=0x%02X, rc=%d\n",
+			slave_addr, rc);
+		return rc;
+	}
+
+	return rc;
+}
+
+static int bif_add_known_slaves_from_dt(struct bif_ctrl_dev *bdev,
+					struct device_node *of_node)
+{
+	int len = 0;
+	int rc, i;
+	u32 addr;
+	const __be32 *val;
+
+	mutex_lock(&bif_sdev_list_mutex);
+	mutex_lock(&bdev->mutex);
+
+	val = of_get_property(of_node, "qcom,known-device-addresses", &len);
+	len /= sizeof(u32);
+	if (val && len == 0) {
+		pr_err("qcom,known-device-addresses property is invalid\n");
+		rc = -EINVAL;
+		goto out;
+	}
+
+	for (i = 0; i < len; i++) {
+		addr = be32_to_cpup(val++);
+		if (addr == 0x00 || addr > 0xFF) {
+			rc = -EINVAL;
+			pr_err("qcom,known-device-addresses property contains invalid address=0x%X\n",
+				addr);
+			goto out;
+		}
+		rc = bif_add_known_slave(bdev, addr);
+		if (rc) {
+			pr_err("bif_add_known_slave() failed, rc=%d\n", rc);
+			goto out;
+		}
+	}
+
+out:
+	if (len > 0)
+		bif_remove_duplicate_slaves(bdev);
+
+	mutex_unlock(&bdev->mutex);
+	mutex_unlock(&bif_sdev_list_mutex);
+
+	return rc;
+}
+
+/*
+ * Programs a device address for the specified slave in order to simplify
+ * slave selection in the future.
+ */
+static int bif_assign_slave_dev_addr(struct bif_slave_dev *sdev, u8 dev_addr)
+{
+	int rc;
+	u16 addr;
+
+	if (!sdev->protocol_function) {
+		pr_err("Protocol function not present; cannot set device address.\n");
+		return -ENODEV;
+	}
+
+	addr = PROTOCOL_FUNC_DEV_ADR_ADDR(
+			sdev->protocol_function->protocol_pointer);
+
+	rc = _bif_slave_write(sdev, addr, &dev_addr, 1);
+	if (rc)
+		pr_err("Failed to set slave device address.\n");
+	else
+		sdev->slave_addr = dev_addr;
+
+	return rc;
+}
+
+/* Assigns a unique device address to all slaves which do not have one. */
+static int bif_assign_all_slaves_dev_addr(struct bif_ctrl_dev *bdev)
+{
+	struct bif_slave_dev *sdev;
+	struct bif_slave_dev *sibling;
+	bool duplicate;
+	int rc = 0;
+	u8 dev_addr, first_dev_addr;
+
+	mutex_lock(&bif_sdev_list_mutex);
+	mutex_lock(&bdev->mutex);
+
+	first_dev_addr = next_dev_addr;
+	/*
+	 * Iterate over all partially known UIDs adding new ones as they are
+	 * found.
+	 */
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		/*
+		 * Skip slaves without known UIDs, which already have a device
+		 * address or which aren't present.
+		 */
+		if (sdev->unique_id_bits_known != BIF_UNIQUE_ID_BIT_LENGTH
+		    || sdev->slave_addr != 0x00 || !sdev->present)
+			continue;
+
+		do {
+			dev_addr = next_dev_addr;
+			duplicate = false;
+			list_for_each_entry(sibling, &bif_sdev_list, list) {
+				if (sibling->slave_addr == dev_addr) {
+					duplicate = true;
+					break;
+				}
+			}
+
+			next_dev_addr = dev_addr + 1;
+		} while (duplicate && (next_dev_addr != first_dev_addr));
+
+		if (next_dev_addr == first_dev_addr) {
+			pr_err("No more BIF slave device addresses available.\n");
+			rc = -ENODEV;
+			goto out;
+		}
+
+		rc =  bif_assign_slave_dev_addr(sdev, dev_addr);
+		if (rc) {
+			pr_err("Failed to set slave address.\n");
+			goto out;
+		}
+	}
+
+	mutex_unlock(&bdev->mutex);
+	mutex_unlock(&bif_sdev_list_mutex);
+
+	return rc;
+
+out:
+	mutex_unlock(&bdev->mutex);
+	mutex_unlock(&bif_sdev_list_mutex);
+	pr_err("BIF slave device address setting failed, rc=%d\n", rc);
+	return rc;
+}
+
+/**
+ * bdev_get_drvdata() - get the private BIF controller driver data
+ * @bdev:	BIF controller device pointer
+ */
+void *bdev_get_drvdata(struct bif_ctrl_dev *bdev)
+{
+	return bdev->driver_data;
+}
+EXPORT_SYMBOL(bdev_get_drvdata);
+
+static const char * const battery_label[] = {
+	"unknown",
+	"none",
+	"special 1",
+	"special 2",
+	"special 3",
+	"low cost",
+	"smart",
+};
+
+static const char *bif_get_battery_pack_type(int rid_ohm)
+{
+	const char *label = battery_label[0];
+
+	if (rid_ohm > BIF_BATT_RID_SMART_MAX)
+		label = battery_label[1];
+	else if (rid_ohm >= BIF_BATT_RID_SMART_MIN)
+		label = battery_label[6];
+	else if (rid_ohm >= BIF_BATT_RID_LOW_COST_MIN
+			&& rid_ohm <= BIF_BATT_RID_LOW_COST_MAX)
+		label = battery_label[5];
+	else if (rid_ohm >= BIF_BATT_RID_SPECIAL3_MIN
+			&& rid_ohm <= BIF_BATT_RID_SPECIAL3_MAX)
+		label = battery_label[4];
+	else if (rid_ohm >= BIF_BATT_RID_SPECIAL2_MIN
+			&& rid_ohm <= BIF_BATT_RID_SPECIAL2_MAX)
+		label = battery_label[3];
+	else if (rid_ohm >= BIF_BATT_RID_SPECIAL1_MIN
+			&& rid_ohm <= BIF_BATT_RID_SPECIAL1_MAX)
+		label = battery_label[2];
+
+	return label;
+}
+
+/**
+ * bif_ctrl_register() - register a BIF controller with the BIF framework
+ * @bif_desc:		Pointer to BIF controller descriptor
+ * @dev:		Device pointer of the BIF controller
+ * @driver_data:	Private driver data to associate with the BIF controller
+ * @of_node		Pointer to the device tree node of the BIF controller
+ *
+ * Returns a BIF controller device pointer for the controller if registration
+ * is successful or an ERR_PTR if an error occurred.
+ */
+struct bif_ctrl_dev *bif_ctrl_register(struct bif_ctrl_desc *bif_desc,
+	struct device *dev, void *driver_data, struct device_node *of_node)
+{
+	struct bif_ctrl_dev *bdev = ERR_PTR(-EINVAL);
+	struct bif_slave_dev *sdev;
+	bool battery_present = false;
+	int rc, rid_ohm;
+
+	if (!bif_desc) {
+		pr_err("Invalid bif_desc specified\n");
+		return bdev;
+	} else if (!bif_desc->name) {
+		pr_err("BIF name missing\n");
+		return bdev;
+	} else if (!bif_desc->ops) {
+		pr_err("BIF operations missing\n");
+		return bdev;
+	} else if (!bif_desc->ops->bus_transaction
+			|| !bif_desc->ops->bus_transaction_query
+			|| !bif_desc->ops->bus_transaction_read
+			|| !bif_desc->ops->get_bus_state
+			|| !bif_desc->ops->set_bus_state) {
+		pr_err("BIF operation callback function(s) missing\n");
+		return bdev;
+	}
+
+	bdev = kzalloc(sizeof(struct bif_ctrl_dev), GFP_KERNEL);
+	if (bdev == NULL) {
+		pr_err("Memory allocation failed for bif_ctrl_dev\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	mutex_init(&bdev->mutex);
+	INIT_LIST_HEAD(&bdev->list);
+	INIT_DELAYED_WORK(&bdev->enter_irq_mode_work, bif_enter_irq_mode_work);
+	bdev->desc			= bif_desc;
+	bdev->ctrl_dev			= dev;
+	bdev->driver_data		= driver_data;
+	bdev->irq_mode_delay_jiffies	= 2;
+
+	mutex_lock(&bif_ctrl_list_mutex);
+	list_add_tail(&bdev->list, &bif_ctrl_list);
+	mutex_unlock(&bif_ctrl_list_mutex);
+
+	rc = bif_add_all_slaves(bdev);
+	if (rc)
+		pr_debug("Search for all slaves failed, rc=%d\n", rc);
+	rc = bif_add_known_slaves_from_dt(bdev, of_node);
+	if (rc)
+		pr_err("Adding slaves based on device tree addressed failed, rc=%d.\n",
+			rc);
+	rc = bif_assign_all_slaves_dev_addr(bdev);
+	if (rc)
+		pr_err("Failed to set slave device address, rc=%d\n", rc);
+
+	bif_print_slaves();
+
+	if (bdev->desc->ops->get_battery_presence) {
+		rc = bdev->desc->ops->get_battery_presence(bdev);
+		if (rc < 0) {
+			pr_err("Could not determine battery presence, rc=%d\n",
+				rc);
+		} else {
+			battery_present = rc;
+			pr_info("Battery pack present = %c\n", rc ? 'Y' : 'N');
+		}
+	}
+
+	if (bdev->desc->ops->get_battery_rid) {
+		rid_ohm = bdev->desc->ops->get_battery_rid(bdev);
+		if (rid_ohm >= 0)
+			pr_info("Battery pack type = %s (Rid=%d ohm)\n",
+				bif_get_battery_pack_type(rid_ohm), rid_ohm);
+		else
+			pr_err("Could not read Rid, rc=%d\n", rid_ohm);
+	}
+
+	list_for_each_entry(sdev, &bif_sdev_list, list) {
+		if (sdev->present) {
+			battery_present = true;
+			break;
+		}
+	}
+
+	BLOCKING_INIT_NOTIFIER_HEAD(&bdev->bus_change_notifier);
+
+	if (battery_present) {
+		bdev->battery_present = true;
+		rc = blocking_notifier_call_chain(&bdev->bus_change_notifier,
+			BIF_BUS_EVENT_BATTERY_INSERTED, bdev);
+		if (rc)
+			pr_err("Call chain noification failed, rc=%d\n", rc);
+	}
+
+	return bdev;
+}
+EXPORT_SYMBOL(bif_ctrl_register);
+
+/**
+ * bif_ctrl_unregister() - unregisters a BIF controller
+ * @bdev:	BIF controller device pointer
+ */
+void bif_ctrl_unregister(struct bif_ctrl_dev *bdev)
+{
+	if (bdev) {
+		mutex_lock(&bif_ctrl_list_mutex);
+		list_del(&bdev->list);
+		mutex_unlock(&bif_ctrl_list_mutex);
+	}
+}
+EXPORT_SYMBOL(bif_ctrl_unregister);
diff --git a/drivers/power/qpnp-bms.c b/drivers/power/qpnp-bms.c
index 85a310a..eb75475 100644
--- a/drivers/power/qpnp-bms.c
+++ b/drivers/power/qpnp-bms.c
@@ -670,10 +670,18 @@
 #define SLEEP_CLK_HZ		32764
 #define SECONDS_PER_HOUR	3600
 
-static s64 cc_uv_to_uvh(s64 cc_uv)
+static s64 cc_uv_to_pvh(s64 cc_uv)
 {
-	return div_s64(cc_uv * CC_READING_TICKS,
-			SLEEP_CLK_HZ * SECONDS_PER_HOUR);
+	/* Note that it is necessary need to multiply by 1000000 to convert
+	 * from uvh to pvh here.
+	 * However, the maximum Coulomb Counter value is 2^35, which can cause
+	 * an over flow.
+	 * Multiply by 100000 first to perserve as much precision as possible
+	 * then multiply by 10 after doing the division in order to avoid
+	 * overflow on the maximum Coulomb Counter value.
+	 */
+	return div_s64(cc_uv * CC_READING_TICKS * 100000,
+			SLEEP_CLK_HZ * SECONDS_PER_HOUR) * 10;
 }
 
 /**
@@ -688,7 +696,7 @@
  */
 static int calculate_cc(struct qpnp_bms_chip *chip, int64_t cc)
 {
-	int64_t cc_voltage_uv, cc_uvh, cc_uah;
+	int64_t cc_voltage_uv, cc_pvh, cc_uah;
 	struct qpnp_iadc_calib calibration;
 
 	qpnp_iadc_get_gain_and_offset(&calibration);
@@ -702,9 +710,9 @@
 					calibration.gain_raw
 					- calibration.offset_raw);
 	pr_debug("cc_voltage_uv = %lld uv\n", cc_voltage_uv);
-	cc_uvh = cc_uv_to_uvh(cc_voltage_uv);
-	pr_debug("cc_uvh = %lld micro_volt_hour\n", cc_uvh);
-	cc_uah = div_s64(cc_uvh * 1000000LL, chip->r_sense_uohm);
+	cc_pvh = cc_uv_to_pvh(cc_voltage_uv);
+	pr_debug("cc_pvh = %lld pvh\n", cc_pvh);
+	cc_uah = div_s64(cc_pvh, chip->r_sense_uohm);
 	/* cc_raw had 4 bits of extra precision.
 	   By now it should be within 32 bit range */
 	return (int)cc_uah;
@@ -1474,16 +1482,12 @@
 static int clamp_soc_based_on_voltage(struct qpnp_bms_chip *chip, int soc)
 {
 	int rc, vbat_uv;
-	struct qpnp_vadc_result result;
 
-	rc = qpnp_vadc_read(VBAT_SNS, &result);
-	if (rc) {
-		pr_err("error reading vbat_sns adc channel = %d, rc = %d\n",
-						VBAT_SNS, rc);
-		return rc;
+	rc = get_battery_voltage(&vbat_uv);
+	if (rc < 0) {
+		pr_err("adc vbat failed err = %d\n", rc);
+		return soc;
 	}
-
-	vbat_uv = (int)result.physical;
 	if (soc == 0 && vbat_uv > chip->v_cutoff_uv) {
 		pr_debug("clamping soc to 1, vbat (%d) > cutoff (%d)\n",
 						vbat_uv, chip->v_cutoff_uv);
@@ -1612,28 +1616,16 @@
 	return chip->calculated_soc;
 }
 
-static int read_vbat(struct qpnp_bms_chip *chip)
-{
-	int rc;
-	struct qpnp_vadc_result result;
-
-	rc = qpnp_vadc_read(VBAT_SNS, &result);
-	if (rc) {
-		pr_err("error reading vadc VBAT_SNS = %d, rc = %d\n",
-					VBAT_SNS, rc);
-		return rc;
-	}
-	pr_debug("read %duv from vadc\n", (int)result.physical);
-	return (int)result.physical;
-}
-
 static int calculate_soc_from_voltage(struct qpnp_bms_chip *chip)
 {
 	int voltage_range_uv, voltage_remaining_uv, voltage_based_soc;
-	int vbat_uv;
+	int rc, vbat_uv;
 
-	vbat_uv = read_vbat(chip);
-
+	rc = get_battery_voltage(&vbat_uv);
+	if (rc < 0) {
+		pr_err("adc vbat failed err = %d\n", rc);
+		return rc;
+	}
 	voltage_range_uv = chip->max_voltage_uv - chip->v_cutoff_uv;
 	voltage_remaining_uv = vbat_uv - chip->v_cutoff_uv;
 	voltage_based_soc = voltage_remaining_uv * 100 / voltage_range_uv;
@@ -2467,7 +2459,12 @@
 	}
 
 	vbatt = 0;
-	get_battery_voltage(&vbatt);
+	rc = get_battery_voltage(&vbatt);
+	if (rc) {
+		pr_err("error reading vbat_sns adc channel = %d, rc = %d\n",
+						VBAT_SNS, rc);
+		goto unregister_dc;
+	}
 
 	pr_info("probe success: soc =%d vbatt = %d ocv = %d r_sense_uohm = %u\n",
 				get_prop_bms_capacity(chip),
diff --git a/include/linux/bif/consumer.h b/include/linux/bif/consumer.h
new file mode 100644
index 0000000..e4c190e
--- /dev/null
+++ b/include/linux/bif/consumer.h
@@ -0,0 +1,613 @@
+/* Copyright (c) 2013, The Linux Foundation. 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 _LINUX_BIF_CONSUMER_H_
+#define _LINUX_BIF_CONSUMER_H_
+
+#include <linux/bitops.h>
+#include <linux/kernel.h>
+#include <linux/notifier.h>
+
+#define BIF_DEVICE_ID_BYTE_LENGTH	8
+#define BIF_UNIQUE_ID_BYTE_LENGTH	10
+#define BIF_UNIQUE_ID_BIT_LENGTH	80
+
+#define BIF_PRIMARY_SLAVE_DEV_ADR	0x01
+
+/**
+ * enum bif_transaction - BIF master bus transaction types
+ * %BIF_TRANS_WD:	Write data
+ * %BIF_TRANS_ERA:	Extended register address
+ * %BIF_TRANS_WRA:	Write register address
+ * %BIF_TRANS_RRA:	Read register address
+ * %BIF_TRANS_BC:	Bus command
+ * %BIF_TRANS_EDA:	Extended device address
+ * %BIF_TRANS_SDA:	Slave device address
+ *
+ * These values correspond to BIF word bits: BCF, bit 9, bit 8.
+ * BCF_n bit is inserted automatically.
+ */
+enum bif_transaction {
+	BIF_TRANS_WD	= 0x00,
+	BIF_TRANS_ERA	= 0x01,
+	BIF_TRANS_WRA	= 0x02,
+	BIF_TRANS_RRA	= 0x03,
+	BIF_TRANS_BC	= 0x04,
+	BIF_TRANS_EDA	= 0x05,
+	BIF_TRANS_SDA	= 0x06,
+};
+
+/* BIF slave response components */
+#define BIF_SLAVE_RD_ACK		0x200
+#define BIF_SLAVE_RD_EOT		0x100
+#define BIF_SLAVE_RD_DATA		0x0FF
+#define BIF_SLAVE_RD_ERR		0x0FF
+#define BIF_SLAVE_TACK_ACK		0x200
+#define BIF_SLAVE_TACK_WCNT		0x0FF
+#define BIF_SLAVE_TACK_ERR		0x0FF
+
+/**
+ * enum bif_bus_command - MIPI defined bus commands to use in BC transaction
+ * %BIF_CMD_BRES:	Bus reset of all slaves
+ * %BIF_CMD_PDWN:	Put all slaves into power down mode
+ * %BIF_CMD_STBY:	Put all slaves into standby mode
+ * %BIF_CMD_EINT:	Enable interrupts for all slaves
+ * %BIF_CMD_ISTS:	Poll interrupt status for all slaves.  Expects BQ
+ *			response if any slave has a pending interrupt.
+ * %BIF_CMD_RBL:	Specify the burst read length for the next read
+ *			transaction.  Bits 3 to 0 should also be ORed on in
+ *			order to specify the number of bytes to read.
+ * %BIF_CMD_RBE:	Specify the extended burst read length for the next read
+ *			transaction.  Bits 3 to 0 should also be ORed on in
+ *			order to specify the number of bytes to read.  The burst
+ *			read length for RBEy and RBLx = 16 * y + x.
+ * %BIF_CMD_DASM:	Device activation stick mode.  This keeps a slave
+ *			selected if it would otherwise become unselected by the
+ *			next transaction.
+ * %BIF_CMD_DISS:	UID search start
+ * %BIF_CMD_DILC:	UID length check.  Expects BQ response if all 80 UID
+ *			bits for a given slave have been entered.
+ * %BIF_CMD_DIE0:	UID search enter 0
+ * %BIF_CMD_DIE1:	UID search enter 1
+ * %BIF_CMD_DIP0:	UID search probe 0
+ * %BIF_CMD_DIP1:	UID search probe 1
+ * %BIF_CMD_DRES:	Device reset of selected slaves
+ * %BIF_CMD_TQ:		Transaction query; expects TACK response
+ * %BIF_CMD_AIO:	Address increment off for the next transaction
+ *
+ * These values correspond to BIF word bits 7 to 0.
+ */
+enum bif_bus_command {
+	BIF_CMD_BRES	= 0x00,
+	BIF_CMD_PDWN	= 0x02,
+	BIF_CMD_STBY	= 0x03,
+	BIF_CMD_EINT	= 0x10,
+	BIF_CMD_ISTS	= 0x11,
+	BIF_CMD_RBL	= 0x20,
+	BIF_CMD_RBE	= 0x30,
+	BIF_CMD_DASM	= 0x40,
+	BIF_CMD_DISS	= 0x80,
+	BIF_CMD_DILC	= 0x81,
+	BIF_CMD_DIE0	= 0x84,
+	BIF_CMD_DIE1	= 0x85,
+	BIF_CMD_DIP0	= 0x86,
+	BIF_CMD_DIP1	= 0x87,
+	BIF_CMD_DRES	= 0xC0,
+	BIF_CMD_TQ	= 0xC2,
+	BIF_CMD_AIO	= 0xC4,
+};
+
+/**
+ * struct bif_ddb_l1_data - MIPI defined L1 DDB data structure
+ * @revision:		DDB version; should be 0x10 for DDB v1.0
+ * @level:		DDB level support; should be 0x03 for DDB L1 and L2
+ * @device_class:	MIPI device class; should be 0x0800
+ * @manufacturer_id:	Manufacturer ID number allocated by MIPI
+ * @product_id:		Manufacturer specified product ID number
+ * @length:		Size of L2 function directory in bytes
+ */
+struct bif_ddb_l1_data {
+	u8	revision;
+	u8	level;
+	u16	device_class;
+	u16	manufacturer_id;
+	u16	product_id;
+	u16	length;
+};
+
+/**
+ * struct bif_ddb_l2_data - MIPI defined L2 DDB function data structure
+ * @function_type:	Defines the type of the function.  The type may be
+ *			either MIPI or manufacturer defined.
+ * @function_version:	Defines the version of the function.  The version may
+ *			be either MIPI or manufacturer defined.
+ * @function_pointer:	Address in BIF slave memory where the register map for
+ *			the function begins.
+ */
+struct bif_ddb_l2_data {
+	u8	function_type;
+	u8	function_version;
+	u16	function_pointer;
+};
+
+/**
+ * enum bif_mipi_function_type - MIPI defined DDB L2 function types
+ * %BIF_FUNC_PROTOCOL:		Protocol function which provides access to core
+ *				BIF communication features.
+ * %BIF_FUNC_SLAVE_CONTROL:	Slave control function which provides control
+ *				for BIF slave interrupts and tasks.
+ * %BIF_FUNC_TEMPERATURE:	Temperature sensor function which provides a
+ *				means to accurately read the battery temperature
+ *				in a single-shot or periodic fashion.
+ * %BIF_FUNC_NVM:		Non-volatile memory function which provides a
+ *				means to store data onto a BIF slave that is
+ *				non-volatile.  Secondary slave objects are also
+ *				found through the NVM function.
+ * %BIF_FUNC_AUTHENTICATION:	Authentication function which provides a means
+ *				to authenticate batteries.  This function does
+ *				not have a MIPI defined implimentation.  Instead
+ *				all aspects of the authentication function are
+ *				left to the discretion of the manufacturer.
+ */
+enum bif_mipi_function_type {
+	BIF_FUNC_PROTOCOL	= 0x01,
+	BIF_FUNC_SLAVE_CONTROL	= 0x02,
+	BIF_FUNC_TEMPERATURE	= 0x03,
+	BIF_FUNC_NVM		= 0x04,
+	BIF_FUNC_AUTHENTICATION	= 0x05,
+};
+
+#define BIF_DDB_L1_BASE_ADDR	0x0000
+#define BIF_DDB_L2_BASE_ADDR	0x000A
+
+/**
+ * enum bif_slave_error_code - MIPI defined BIF slave error codes
+ * %BIF_ERR_NONE:		No error occurred
+ * %BIF_ERR_GENERAL:		An unenumerated error occurred
+ * %BIF_ERR_PARITY:		A Hamming-15 parity check failed for a word
+ *				sent on the bus
+ * %BIF_ERR_INVERSION:		More than 8 bits in a word were 1
+ * %BIF_ERR_BAD_LENGTH:		Word had more or less than 17 bits
+ * %BIF_ERR_TIMING:		Bit timing was violated in a word
+ * %BIF_ERR_UNKNOWN_CMD:	Bus command was unknown to the slave
+ * %BIF_ERR_CMD_SEQ:		Commands with ordering dependency were not
+ *				sent in the right order
+ * %BIF_ERR_BUS_COLLISION:	BCL was already low at the beginning of a new
+ *				transaction
+ * %BIF_ERR_SLAVE_BUSY:		Slave is busy and cannot respond
+ * %BIF_ERR_FATAL:		Slave is in an unrecoverable error state and
+ *				must be reset
+ *
+ * These values are present in the ERR portion of an RD or TACK slave response
+ * word.  These values can also be found in the ERR_CODE register of the
+ * protocol function.
+ */
+enum bif_slave_error_code {
+	BIF_ERR_NONE		= 0x00,
+	BIF_ERR_GENERAL		= 0x10,
+	BIF_ERR_PARITY		= 0x11,
+	BIF_ERR_INVERSION	= 0x12,
+	BIF_ERR_BAD_LENGTH	= 0x13,
+	BIF_ERR_TIMING		= 0x14,
+	BIF_ERR_UNKNOWN_CMD	= 0x15,
+	BIF_ERR_CMD_SEQ		= 0x16,
+	BIF_ERR_BUS_COLLISION	= 0x1F,
+	BIF_ERR_SLAVE_BUSY	= 0x20,
+	BIF_ERR_FATAL		= 0x7F,
+};
+
+/**
+ * struct bif_protocol_function - constant data present in protocol function
+ * @l2_entry:		Pointer to protocol function L2 DDB data struct
+ * @protocol_pointer:	BIF slave address where protocol registers begin
+ * @device_id_pointer:	BIF slave address where device ID begins
+ * @device_id:		The 8-byte unique device ID in MSB to LSB order
+ */
+struct bif_protocol_function {
+	struct bif_ddb_l2_data *l2_entry;
+	u16	protocol_pointer;
+	u16	device_id_pointer;
+	u8	device_id[BIF_DEVICE_ID_BYTE_LENGTH]; /* Unique ID */
+};
+
+#define PROTOCOL_FUNC_DEV_ADR_ADDR(protocol_pointer)	((protocol_pointer) + 0)
+#define PROTOCOL_FUNC_ERR_CODE_ADDR(protocol_pointer)	((protocol_pointer) + 2)
+#define PROTOCOL_FUNC_ERR_CNT_ADDR(protocol_pointer)	((protocol_pointer) + 3)
+#define PROTOCOL_FUNC_WORD_CNT_ADDR(protocol_pointer)	((protocol_pointer) + 4)
+
+/**
+ * struct bif_slave_control_function - constant data present in slave control
+ *			function as well internal software state parameters
+ * @l2_entry:		Pointer to slave control function L2 DDB data struct
+ * @slave_ctrl_pointer:	BIF slave address where slave control registers begin
+ * @task_count:		Number of tasks supported by the slave
+ * @irq_notifier_list:	List of notifiers for consumers drivers that wish to be
+ *			notified when any given interrupt triggers.  This list
+ *			is dynamically allocated with length task_count.
+ */
+struct bif_slave_control_function {
+	struct bif_ddb_l2_data		*l2_entry;
+	u16				slave_ctrl_pointer;
+	unsigned int			task_count;
+	struct blocking_notifier_head	*irq_notifier_list;
+};
+
+#define SLAVE_CTRL_TASKS_PER_SET	8
+
+/**
+ * bif_slave_control_task_is_valid() - returns true if the specified task
+ *		is supported by the slave or false if it isn't
+ * @func:	Pointer to slave's slave control function structure
+ * @task:	Slave task number to check
+ */
+static inline bool
+bif_slave_control_task_is_valid(struct bif_slave_control_function *func,
+				unsigned int task)
+{
+	return func ? task < func->task_count : false;
+}
+
+#define SLAVE_CTRL_FUNC_IRQ_EN_ADDR(slave_ctrl_pointer, task) \
+	((slave_ctrl_pointer) + 4 * ((task) / SLAVE_CTRL_TASKS_PER_SET) + 0)
+
+#define SLAVE_CTRL_FUNC_IRQ_STATUS_ADDR(slave_ctrl_pointer, task) \
+	((slave_ctrl_pointer) + 4 * ((task) / SLAVE_CTRL_TASKS_PER_SET) + 1)
+#define SLAVE_CTRL_FUNC_IRQ_CLEAR_ADDR(slave_ctrl_pointer, task) \
+	SLAVE_CTRL_FUNC_IRQ_STATUS_ADDR(slave_ctrl_pointer, task)
+
+#define SLAVE_CTRL_FUNC_TASK_TRIGGER_ADDR(slave_ctrl_pointer, task) \
+	((slave_ctrl_pointer) + 4 * ((task) / SLAVE_CTRL_TASKS_PER_SET) + 2)
+#define SLAVE_CTRL_FUNC_TASK_BUSY_ADDR(slave_ctrl_pointer, task) \
+	SLAVE_CTRL_FUNC_TASK_TRIGGER_ADDR(slave_ctrl_pointer, task)
+
+#define SLAVE_CTRL_FUNC_TASK_AUTO_TRIGGER_ADDR(slave_ctrl_pointer, task) \
+	((slave_ctrl_pointer) + 4 * ((task) / SLAVE_CTRL_TASKS_PER_SET) + 3)
+
+/**
+ * struct bif_temperature_function - constant data present in temperature
+ *				sensor function
+ * @temperatuer_pointer:	BIF slave address where temperature sensor
+ *				control registers begin
+ * @slave_control_channel:	Slave control channel associated with the
+ *				temperature sensor function.  This channel is
+ *				also the task number.
+ * @accuracy_pointer:		BIF slave address where temperature accuracy
+ *				registers begin
+ */
+struct bif_temperature_function {
+	u16	temperature_pointer;
+	u8	slave_control_channel;
+	u16	accuracy_pointer;
+};
+
+/**
+ * enum bif_mipi_object_type - MIPI defined BIF object types
+ * %BIF_OBJ_END_OF_LIST:	Indicates that the end of the object list in
+ *				NVM has been reached
+ * %BIF_OBJ_SEC_SLAVE:		Specifies the UIDs of secondary slaves found
+ *				inside of the battery pack
+ * %BIF_OBJ_BATT_PARAM:		Specifies some variety of battery parameter.
+ *				There is no MIPI defined format for this object
+ *				type so parsing is manufacturer specific.
+ */
+enum bif_mipi_object_type {
+	BIF_OBJ_END_OF_LIST	= 0x00,
+	BIF_OBJ_SEC_SLAVE	= 0x01,
+	BIF_OBJ_BATT_PARAM	= 0x02,
+};
+
+/**
+ * struct bif_object - contains all header and data information for a slave
+ *			data object
+ * @type:		Object type
+ * @version:		Object version
+ * @manufacturer_id:	Manufacturer ID number allocated by MIPI
+ * @length:		Length of the entire object including header and CRC
+ * @data:		Raw byte data found in the object
+ * @crc:		CRC of the object calculated using CRC-CCITT
+ * @list:		Linked-list connection parameter
+ * @addr:		BIF slave address correspond to the start of the object
+ *
+ * manufacturer_id == 0x0000 if MIPI type and version.
+ */
+struct bif_object {
+	u8			type;
+	u8			version;
+	u16			manufacturer_id;
+	u16			length;
+	u8			*data;
+	u16			crc;
+	struct list_head	list;
+	u16			addr;
+};
+
+/**
+ * struct bif_nvm_function - constant data present in non-volatile memory
+ *				function as well internal software state
+ *				parameters
+ * @nvm_pointer:		BIF slave address where NVM registers begin
+ * @slave_control_channel:	Slave control channel associated with the
+ *				NVM function.  This channel is also the task
+ *				number.
+ * @write_buffer_size:		Size in bytes of the NVM write buffer.  0x00
+ *				is used to denote a 256 byte buffer.
+ * @nvm_base_address:		BIF slave address where NVM begins
+ * @nvm_size:			NVM size in bytes
+ * @object_count:		Number of BIF objects read from NVM
+ * @object_list:		List of BIF objects read from NVM
+ */
+struct bif_nvm_function {
+	u16			nvm_pointer;
+	u8			slave_control_channel;
+	u8			write_buffer_size;
+	u16			nvm_base_address;
+	u16			nvm_size;
+	int			object_count;
+	struct list_head	object_list;
+};
+
+/**
+ * struct bif_ctrl - Opaque handle for a BIF controller to be used in bus
+ *			oriented BIF function calls.
+ */
+struct bif_ctrl;
+
+/**
+ * struct bif_slave - Opaque handle for a BIF slave to be used in slave oriented
+ *			BIF function calls.
+ */
+struct bif_slave;
+
+/**
+ * enum bif_bus_state - indicates the current or desired state of the BIF bus
+ * %BIF_BUS_STATE_MASTER_DISABLED:	BIF host hardware is disabled
+ * %BIF_BUS_STATE_POWER_DOWN:		BIF bus is in power down state and
+ *					BCL is not being pulled high
+ * %BIF_BUS_STATE_STANDBY:		BIF slaves are in standby state in which
+ *					less power is drawn
+ * %BIF_BUS_STATE_ACTIVE:		BIF slaves are ready for immediate
+ *					communications
+ * %BIF_BUS_STATE_INTERRUPT:		BIF bus is active, but no communication
+ *					is possible.  Instead, either one of the
+ *					slaves or the master must transition to
+ *					active state by pulling BCL low for 1
+ *					tau bif period.
+ */
+enum bif_bus_state {
+	BIF_BUS_STATE_MASTER_DISABLED,
+	BIF_BUS_STATE_POWER_DOWN,
+	BIF_BUS_STATE_STANDBY,
+	BIF_BUS_STATE_ACTIVE,
+	BIF_BUS_STATE_INTERRUPT,
+};
+
+/**
+ * enum bif_bus_event - events that the BIF framework may send to BIF consumers
+ * %BIF_BUS_EVENT_BATTERY_INSERTED:	Indicates that a battery was just
+ *					inserted physically or that the BIF
+ *					host controller for the battery just
+ *					probed and a battery was already
+ *					present.
+ * %BIF_BUS_EVENT_BATTERY_REMOVED:	Indicates that a battery was just
+ *					removed and thus its slaves are no
+ *					longer accessible.
+ */
+enum bif_bus_event {
+	BIF_BUS_EVENT_BATTERY_INSERTED,
+	BIF_BUS_EVENT_BATTERY_REMOVED,
+};
+
+/* Mask values to be ORed together for use in bif_match_criteria.match_mask. */
+#define BIF_MATCH_MANUFACTURER_ID	BIT(0)
+#define BIF_MATCH_PRODUCT_ID		BIT(1)
+#define BIF_MATCH_FUNCTION_TYPE		BIT(2)
+#define BIF_MATCH_FUNCTION_VERSION	BIT(3)
+#define BIF_MATCH_IGNORE_PRESENCE	BIT(4)
+
+/**
+ * struct bif_match_criteria - specifies the matching criteria that a BIF
+ *			consumer uses to find an appropriate BIF slave
+ * @match_mask:		Mask value specifying which parameters to match upon.
+ *			This value should be some ORed combination of
+ *			BIF_MATCH_* specified above.
+ * @manufacturer_id:	Manufacturer ID number allocated by MIPI
+ * @product_id:		Manufacturer specified product ID number
+ * @function_type:	Defines the type of the function.  The type may be
+ *			either MIPI or manufacturer defined.
+ * @function_version:	Defines the version of the function.  The version may
+ *			be either MIPI or manufacturer defined.
+ * @ignore_presence:	If true, then slaves that are currently not present
+ *			will be successfully matched against.  By default, only
+ *			present slaves can be matched.
+ */
+struct bif_match_criteria {
+	u32	match_mask;
+	u16	manufacturer_id;
+	u16	product_id;
+	u8	function_type;
+	u8	function_version;
+	bool	ignore_presence;
+};
+
+/**
+ * bif_battery_rid_ranges - MIPI-BIF defined Rid battery pack resistance ranges
+ * %BIF_BATT_RID_SPECIAL1_MIN:	Minimum Rid for special case 1
+ * %BIF_BATT_RID_SPECIAL1_MAX:	Maximum Rid for special case 1
+ * %BIF_BATT_RID_SPECIAL2_MIN:	Minimum Rid for special case 2
+ * %BIF_BATT_RID_SPECIAL2_MAX:	Maximum Rid for special case 2
+ * %BIF_BATT_RID_SPECIAL3_MIN:	Minimum Rid for special case 3
+ * %BIF_BATT_RID_SPECIAL3_MAX:	Maximum Rid for special case 3
+ * %BIF_BATT_RID_LOW_COST_MIN:	Minimum Rid for a low cost battery pack
+ * %BIF_BATT_RID_LOW_COST_MAX:	Maximum Rid for a low cost battery pack
+ * %BIF_BATT_RID_SMART_MIN:	Minimum Rid for a smart battery pack
+ * %BIF_BATT_RID_SMART_MAX:	Maximum Rid for a smart battery pack
+ */
+enum bif_battery_rid_ranges {
+	BIF_BATT_RID_SPECIAL1_MIN	= 0,
+	BIF_BATT_RID_SPECIAL1_MAX	= 1,
+	BIF_BATT_RID_SPECIAL2_MIN	= 7350,
+	BIF_BATT_RID_SPECIAL2_MAX	= 7650,
+	BIF_BATT_RID_SPECIAL3_MIN	= 12740,
+	BIF_BATT_RID_SPECIAL3_MAX	= 13260,
+	BIF_BATT_RID_LOW_COST_MIN	= 19600,
+	BIF_BATT_RID_LOW_COST_MAX	= 140000,
+	BIF_BATT_RID_SMART_MIN		= 240000,
+	BIF_BATT_RID_SMART_MAX		= 450000,
+};
+
+#ifdef CONFIG_BIF
+
+int bif_request_irq(struct bif_slave *slave, unsigned int task,
+			struct notifier_block *nb);
+int bif_free_irq(struct bif_slave *slave, unsigned int task,
+			struct notifier_block *nb);
+
+int bif_trigger_task(struct bif_slave *slave, unsigned int task);
+int bif_task_is_busy(struct bif_slave *slave, unsigned int task);
+
+int bif_ctrl_count(void);
+struct bif_ctrl *bif_ctrl_get_by_id(unsigned int id);
+struct bif_ctrl *bif_ctrl_get(struct device *consumer_dev);
+void bif_ctrl_put(struct bif_ctrl *ctrl);
+
+int bif_ctrl_signal_battery_changed(struct bif_ctrl *ctrl);
+
+int bif_slave_match_count(const struct bif_ctrl *ctrl,
+			const struct bif_match_criteria *match_criteria);
+
+struct bif_slave *bif_slave_match_get(const struct bif_ctrl *ctrl,
+	unsigned int id, const struct bif_match_criteria *match_criteria);
+
+void bif_slave_put(struct bif_slave *slave);
+
+int bif_ctrl_notifier_register(struct bif_ctrl *ctrl,
+				struct notifier_block *nb);
+
+int bif_ctrl_notifier_unregister(struct bif_ctrl *ctrl,
+				struct notifier_block *nb);
+
+struct bif_ctrl *bif_get_ctrl_handle(struct bif_slave *slave);
+
+int bif_slave_find_function(struct bif_slave *slave, u8 function, u8 *version,
+				u16 *function_pointer);
+
+int bif_slave_read(struct bif_slave *slave, u16 addr, u8 *buf, int len);
+int bif_slave_write(struct bif_slave *slave, u16 addr, u8 *buf, int len);
+
+int bif_slave_is_present(struct bif_slave *slave);
+
+int bif_slave_is_selected(struct bif_slave *slave);
+int bif_slave_select(struct bif_slave *slave);
+
+int bif_ctrl_raw_transaction(struct bif_ctrl *ctrl, int transaction, u8 data);
+int bif_ctrl_raw_transaction_read(struct bif_ctrl *ctrl, int transaction,
+					u8 data, int *response);
+int bif_ctrl_raw_transaction_query(struct bif_ctrl *ctrl, int transaction,
+		u8 data, bool *query_response);
+
+void bif_ctrl_bus_lock(struct bif_ctrl *ctrl);
+void bif_ctrl_bus_unlock(struct bif_ctrl *ctrl);
+
+u16 bif_crc_ccitt(const u8 *buffer, unsigned int len);
+
+int bif_ctrl_measure_rid(struct bif_ctrl *ctrl);
+int bif_ctrl_get_bus_period(struct bif_ctrl *ctrl);
+int bif_ctrl_set_bus_period(struct bif_ctrl *ctrl, int period_ns);
+int bif_ctrl_get_bus_state(struct bif_ctrl *ctrl);
+int bif_ctrl_set_bus_state(struct bif_ctrl *ctrl, enum bif_bus_state state);
+
+#else
+
+static inline int bif_request_irq(struct bif_slave *slave, unsigned int task,
+			struct notifier_block *nb) { return -EPERM; }
+static inline int bif_free_irq(struct bif_slave *slave, unsigned int task,
+			struct notifier_block *nb) { return -EPERM; }
+
+static inline int bif_trigger_task(struct bif_slave *slave, unsigned int task)
+{ return -EPERM; }
+static inline int bif_task_is_busy(struct bif_slave *slave, unsigned int task)
+{ return -EPERM; }
+
+static inline int bif_ctrl_count(void) { return -EPERM; }
+static inline struct bif_ctrl *bif_ctrl_get_by_id(unsigned int id)
+{ return ERR_PTR(-EPERM); }
+struct bif_ctrl *bif_ctrl_get(struct device *consumer_dev)
+{ return ERR_PTR(-EPERM); }
+static inline void bif_ctrl_put(struct bif_ctrl *ctrl) { return; }
+
+int bif_ctrl_signal_battery_changed(struct bif_ctrl *ctrl) { return -EPERM; }
+
+static inline int bif_slave_match_count(const struct bif_ctrl *ctrl,
+			const struct bif_match_criteria *match_criteria)
+{ return -EPERM; }
+
+static inline struct bif_slave *bif_slave_match_get(const struct bif_ctrl *ctrl,
+	unsigned int id, const struct bif_match_criteria *match_criteria)
+{ return ERR_PTR(-EPERM); }
+
+static inline void bif_slave_put(struct bif_slave *slave) { return; }
+
+static inline int bif_ctrl_notifier_register(struct bif_ctrl *ctrl,
+				struct notifier_block *nb)
+{ return -EPERM; }
+
+static inline int bif_ctrl_notifier_unregister(struct bif_ctrl *ctrl,
+				struct notifier_block *nb)
+{ return -EPERM; }
+
+static inline struct bif_ctrl *bif_get_ctrl_handle(struct bif_slave *slave)
+{ return ERR_PTR(-EPERM); }
+
+static inline int bif_slave_find_function(struct bif_slave *slave, u8 function,
+				u8 *version, u16 *function_pointer)
+{ return -EPERM; }
+
+static inline int bif_slave_read(struct bif_slave *slave, u16 addr, u8 *buf,
+				int len)
+{ return -EPERM; }
+static inline int bif_slave_write(struct bif_slave *slave, u16 addr, u8 *buf,
+				int len)
+{ return -EPERM; }
+
+int bif_slave_is_present(struct bif_slave *slave) { return -EPERM; }
+
+int bif_slave_is_selected(struct bif_slave *slave) { return -EPERM; }
+int bif_slave_select(struct bif_slave *slave) { return -EPERM; }
+
+int bif_ctrl_raw_transaction(struct bif_ctrl *ctrl, int transaction, u8 data)
+{ return -EPERM; }
+int bif_ctrl_raw_transaction_read(struct bif_ctrl *ctrl, int transaction,
+					u8 data, int *response)
+{ return -EPERM; }
+int bif_ctrl_raw_transaction_query(struct bif_ctrl *ctrl, int transaction,
+		u8 data, bool *query_response)
+{ return -EPERM; }
+
+static inline void bif_ctrl_bus_lock(struct bif_ctrl *ctrl)
+{ return -EPERM; }
+static inline void bif_ctrl_bus_unlock(struct bif_ctrl *ctrl)
+{ return -EPERM; }
+
+static inline u16 bif_crc_ccitt(const u8 *buffer, unsigned int len)
+{ return 0; }
+
+static inline int bif_ctrl_measure_rid(struct bif_ctrl *ctrl) { return -EPERM; }
+int bif_ctrl_get_bus_period(struct bif_ctrl *ctrl) { return -EPERM; }
+int bif_ctrl_set_bus_period(struct bif_ctrl *ctrl, int period_ns)
+{ return -EPERM; }
+int bif_ctrl_get_bus_state(struct bif_ctrl *ctrl) { return -EPERM; }
+int bif_ctrl_set_bus_state(struct bif_ctrl *ctrl, enum bif_bus_state state)
+{ return -EPERM; }
+
+#endif
+
+#endif
diff --git a/include/linux/bif/driver.h b/include/linux/bif/driver.h
new file mode 100644
index 0000000..184d46f
--- /dev/null
+++ b/include/linux/bif/driver.h
@@ -0,0 +1,161 @@
+/* Copyright (c) 2013, The Linux Foundation. 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 _LINUX_BIF_DRIVER_H_
+#define _LINUX_BIF_DRIVER_H_
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/types.h>
+#include <linux/bif/consumer.h>
+
+/**
+ * struct bif_ctrl_dev - opaque handle used to identify a given BIF controller
+ *			device
+ */
+struct bif_ctrl_dev;
+
+/**
+ * struct bif_ctrl_ops - BIF operations which may be implemented by BIF
+ *				controller drivers
+ * @bus_transaction:		Perform the specified BIF transaction which does
+ *				not result in any slave response.
+ * @bus_transaction_query:	Perform the specified BIF transaction which
+ *				expects a BQ response in the case of slave
+ *				positive acknowledgement.
+ * @bus_transaction_read:	Perform the specified BIF transaction which
+ *				expects an RD or TACK response from the selected
+ *				slave.
+ * @read_slave_registers:	Perform all BIF transactions necessary to read
+ *				the specified set of contiguous registers from
+ *				the previously selected slave.  This operation
+ *				is used to optimize the common case of slave
+ *				register reads since the a BIF controller driver
+ *				can take advantage of BIF burst reads while the
+ *				BIF core driver cannot due to the inherient
+ *				tight timing requirements.
+ * @write_slave_registers:	Perform all BIF transactions necessary to write
+ *				the specified set of contiguous registers to
+ *				the previously selected slave.  This operation
+ *				is used to optimize the common case of slave
+ *				register writes since the a BIF controller
+ *				driver can remove redundant steps when
+ *				performing several WD commands in a row.
+ * @get_bus_period:		Return the tau_bif BIF bus clock period in
+ *				nanoseconds.
+ * @set_bus_period:		Set the tau_bif BIF bus clock period in
+ *				nanoseconds.  If the exact period is not
+ *				supported by the BIF controller hardware, then
+ *				the next larger supported period should be used.
+ * @get_battery_presence:	Return the current state of the battery pack.
+ *				If a battery pack is present, then return >= 1.
+ *				If a battery pack is not present, then return 0.
+ *				If an error occurs during presence detection,
+ *				then return errno.
+ * @get_battery_rid:		Return the measured value of the Rid battery
+ *				pack pull-down resistor in ohms.
+ * @get_bus_state:		Return the current bus state as defined by one
+ *				of the enum bif_bus_state values.
+ * @set_bus_state:		Set the BIF bus state to the specified enum
+ *				bif_bus_state value.
+ *
+ * The following operations must be defined by every BIF controller driver in
+ * order to ensure baseline functionality:
+ * bus_transaction, bus_transaction_query, get_bus_state, and set_bus_state.
+ *
+ * The BIF core driver is unaware of BIF transaction timing constraints.  A
+ * given BIF controller driver must ensure that all timing constraints in the
+ * MIPI-BIF specification are met as transactions are carried out.
+ *
+ * Conversion between 11-bit and 17-bit BIF words (i.e. the insertion of BCF_n,
+ * parity bits, and the inversion bit) must be handled inside of the BIF
+ * controller driver (either in software or hardware).  This guarantees maximum
+ * performance if hardware support is available.
+ *
+ * The bus_transaction_read operation must return -ETIMEDOUT in the case of no
+ * RD or TACK word received.  This allows the transaction query, TQ, command
+ * to be used for slave selection verification.
+ *
+ * It is acceptable for the BIF bus state to be changed autonomously by a BIF
+ * controller driver in response to low level bus actions without a call to
+ * set_bus_state.  One example is the case of receiving a slave interrupt
+ * while in interrupt state as this intrinsically causes the bus to enter the
+ * active communication state.
+ */
+struct bif_ctrl_ops {
+	int (*bus_transaction) (struct bif_ctrl_dev *bdev, int transaction,
+					u8 data);
+	int (*bus_transaction_query) (struct bif_ctrl_dev *bdev,
+					int transaction, u8 data,
+					bool *query_response);
+	int (*bus_transaction_read) (struct bif_ctrl_dev *bdev,
+					int transaction, u8 data,
+					int *response);
+	int (*read_slave_registers) (struct bif_ctrl_dev *bdev, u16 addr,
+					u8 *data, int len);
+	int (*write_slave_registers) (struct bif_ctrl_dev *bdev, u16 addr,
+					const u8 *data, int len);
+	int (*get_bus_period) (struct bif_ctrl_dev *bdev);
+	int (*set_bus_period) (struct bif_ctrl_dev *bdev, int period_ns);
+	int (*get_battery_presence) (struct bif_ctrl_dev *bdev);
+	int (*get_battery_rid) (struct bif_ctrl_dev *bdev);
+	int (*get_bus_state) (struct bif_ctrl_dev *bdev);
+	int (*set_bus_state) (struct bif_ctrl_dev *bdev, int state);
+};
+
+/**
+ * struct bif_ctrl_desc - BIF bus controller descriptor
+ * @name:		Name used to identify the BIF controller
+ * @ops:		BIF operations supported by the BIF controller
+ * @bus_clock_min_ns:	Minimum tau_bif BIF bus clock period supported by the
+ *			BIF controller
+ * @bus_clock_max_ns:	Maximum tau_bif BIF bus clock period supported by the
+ *			BIF controller
+ *
+ * Each BIF controller registered with the BIF core is described with a
+ * structure of this type.
+ */
+struct bif_ctrl_desc {
+	const char *name;
+	struct bif_ctrl_ops *ops;
+	int bus_clock_min_ns;
+	int bus_clock_max_ns;
+};
+
+#ifdef CONFIG_BIF
+
+struct bif_ctrl_dev *bif_ctrl_register(struct bif_ctrl_desc *bif_desc,
+	struct device *dev, void *driver_data, struct device_node *of_node);
+
+void bif_ctrl_unregister(struct bif_ctrl_dev *bdev);
+
+void *bdev_get_drvdata(struct bif_ctrl_dev *bdev);
+
+int bif_ctrl_notify_battery_changed(struct bif_ctrl_dev *bdev);
+int bif_ctrl_notify_slave_irq(struct bif_ctrl_dev *bdev);
+
+#else
+
+static inline struct bif_ctrl_dev *bif_ctrl_register(
+	struct bif_ctrl_desc *bif_desc, struct device *dev, void *driver_data,
+	struct device_node *of_node)
+{ return ERR_PTR(-EINVAL); }
+
+static inline void bif_ctrl_unregister(struct bif_ctrl_dev *bdev) { }
+
+static inline void *bdev_get_drvdata(struct bif_ctrl_dev *bdev) { return NULL; }
+
+int bif_ctrl_notify_slave_irq(struct bif_ctrl_dev *bdev) { return -EINVAL; }
+
+#endif
+
+#endif