msm: ext-buck-control: add external buck support driver
Based on the dt file entry enables the external buck support
for sending active set and sleep set votes to turn-on and turn-off
external buck by toggling a gpio when the system is going PC.
CRs-fixed: 568380
Change-Id: Ib8ccb7d8a5a264f30a9b0f365637e418c2f6332b
Signed-off-by: Anil kumar mamidala <amami@codeaurora.org>
diff --git a/Documentation/devicetree/bindings/arm/msm/ext-buck-control.txt b/Documentation/devicetree/bindings/arm/msm/ext-buck-control.txt
new file mode 100644
index 0000000..37c0995
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/ext-buck-control.txt
@@ -0,0 +1,26 @@
+* MSM EXT BUCK REGULATOR CONTROL
+
+External buck regulator is used to power up the APC rail.
+This buck can be turn-on & turn-off by toggling a gpio
+line which is connected to buck enable pin. This driver
+control the external regulator behaviour with the help
+of RPM by sending the sleep and active sets when APPS
+decide to enter into low power state with RPM assisted.
+
+The required properties for EXT BUCK CONTROL are:
+
+- compatible: "qcom,ext-buck-control"
+
+The optional properties are:
+- qcom,gpio-num: Indicates the GPIO number which will turn-on and turn-off
+ the external buck.
+- qcom,settling-time-us: Indicates the settling time for the external buck to
+ get turn-on or turn-off. Settling time is calculated
+ in terms of QTIMER(19.2MHz) and the value is in us.
+
+Example:
+ qcom,ext-buck-control {
+ compatible = "qcom,ext-buck-control";
+ qcom,gpio-num = <50>;
+ qcom,settling-time-us = <2580>;
+};
diff --git a/arch/arm/mach-msm/Makefile b/arch/arm/mach-msm/Makefile
index 9c9fffc..1c07e7d 100644
--- a/arch/arm/mach-msm/Makefile
+++ b/arch/arm/mach-msm/Makefile
@@ -297,7 +297,7 @@
obj-$(CONFIG_ARCH_MSM8610) += clock-dsi-8610.o
obj-$(CONFIG_ARCH_MSMKRYPTON) += clock-local2.o clock-pll.o clock-krypton.o clock-rpm.o clock-voter.o
-obj-$(CONFIG_MSM_PM) += msm-pm.o pm-data.o
+obj-$(CONFIG_MSM_PM) += msm-pm.o pm-data.o ext-buck-control.o
obj-$(CONFIG_MACH_SAPPHIRE) += board-sapphire.o board-sapphire-gpio.o
obj-$(CONFIG_MACH_SAPPHIRE) += board-sapphire-keypad.o board-sapphire-panel.o
diff --git a/arch/arm/mach-msm/ext-buck-control.c b/arch/arm/mach-msm/ext-buck-control.c
new file mode 100644
index 0000000..e0c349a
--- /dev/null
+++ b/arch/arm/mach-msm/ext-buck-control.c
@@ -0,0 +1,121 @@
+/* Copyright (c) 2014, 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <mach/rpm-smd.h>
+
+#define RPM_REQUEST_TYPE_GPIO 0x6f697067 /* gpio */
+#define RPM_GPIO_NUMB_KEY 0x626d756e /* numb */
+#define RPM_GPIO_STAT_KEY 0x74617473 /* stat */
+#define RPM_GPIO_SETT_KEY 0x74746573 /* sett */
+#define RPM_GPIO_RESOURCE_ID 3
+#define GPIO_ON 1
+#define GPIO_OFF 0
+
+static int msm_send_ext_buck_votes(int gpio_num, int settling_time)
+{
+ int rc;
+ int gpio_status_sleep = GPIO_OFF;
+ int gpio_status_active = GPIO_ON;
+
+ struct msm_rpm_kvp kvp_sleep[] = {
+ {
+ .key = RPM_GPIO_STAT_KEY,
+ .data = (void *)&gpio_status_sleep,
+ .length = sizeof(gpio_status_sleep),
+ }
+ };
+
+ struct msm_rpm_kvp kvp_active[] = {
+ {
+ .key = RPM_GPIO_NUMB_KEY,
+ .data = (void *)&gpio_num,
+ .length = sizeof(gpio_num),
+ },
+ {
+ .key = RPM_GPIO_STAT_KEY,
+ .data = (void *)&gpio_status_active,
+ .length = sizeof(gpio_status_active),
+ },
+ {
+ .key = RPM_GPIO_SETT_KEY,
+ .data = (void *)&settling_time,
+ .length = sizeof(settling_time),
+ },
+ };
+
+ rc = msm_rpm_send_message(MSM_RPM_CTX_ACTIVE_SET,
+ RPM_REQUEST_TYPE_GPIO, RPM_GPIO_RESOURCE_ID, kvp_active,
+ ARRAY_SIZE(kvp_active));
+ WARN(rc < 0, "RPM GPIO toggling (active set) did not enable!\n");
+
+ rc = msm_rpm_send_message(MSM_RPM_CTX_SLEEP_SET,
+ RPM_REQUEST_TYPE_GPIO, RPM_GPIO_RESOURCE_ID, kvp_sleep,
+ ARRAY_SIZE(kvp_sleep));
+ WARN(rc < 0, "RPM GPIO toggling (sleep set) did not enable!\n");
+
+ return rc;
+}
+
+static int msm_ext_buck_probe(struct platform_device *pdev)
+{
+ char *key = NULL;
+ int gpio_num;
+ int settling_time_us;
+ int ret = 0;
+
+ key = "qcom,gpio-num";
+ ret = of_property_read_u32(pdev->dev.of_node, key, &gpio_num);
+ if (ret) {
+ pr_err("%s: Cannot read %s from dt (ret:%d)\n",
+ __func__, key, ret);
+ return ret;
+ }
+
+ key = "qcom,settling-time-us";
+ ret = of_property_read_u32(pdev->dev.of_node, key,
+ &settling_time_us);
+ if (ret) {
+ pr_err("%s: Cannot read %s from dt (ret:%d)\n",
+ __func__, key, ret);
+ return ret;
+ }
+
+ ret = msm_send_ext_buck_votes(gpio_num, settling_time_us);
+
+ return ret;
+}
+
+static struct of_device_id msm_ext_buck_table[] = {
+ {.compatible = "qcom,ext-buck-control"},
+ {},
+};
+
+static struct platform_driver msm_ext_buck_driver = {
+ .probe = msm_ext_buck_probe,
+ .driver = {
+ .name = "ext-buck-control",
+ .owner = THIS_MODULE,
+ .of_match_table = msm_ext_buck_table,
+ },
+};
+
+static int __init msm_ext_buck_init(void)
+{
+ return platform_driver_register(&msm_ext_buck_driver);
+}
+late_initcall(msm_ext_buck_init);