input: misc: add regulator-haptic driver

Haptic motor controlled by voltage in regulator. And driver support
force-feedback interface.

Signed-off-by: Hyunhee Kim <hyunhee.kim@samsung.com>
[code cleanup and add detailed description by Jaewon Kim]
Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>

3 files changed, 239 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index bb698e1f9e4..df022bb2b37 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -93,6 +93,17 @@ config INPUT_BMA150
 	  To compile this driver as a module, choose M here: the
 	  module will be called bma150.
 
+config INPUT_REGULATOR_HAPTIC
+	tristate "regulator haptics support"
+	select INPUT_FF_MEMLESS
+	help
+	  This option enables device driver support for the haptic controlled
+	  by regulator. This driver supports ff-memless interface
+	  from input framework.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called regulator-haptic.
+
 config INPUT_PCSPKR
 	tristate "PC Speaker support"
 	depends on PCSPKR_PLATFORM
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index d7fc17f11d7..88c60df7b9d 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -28,6 +28,7 @@ obj-$(CONFIG_INPUT_DA9055_ONKEY)	+= da9055_onkey.o
 obj-$(CONFIG_INPUT_DM355EVM)		+= dm355evm_keys.o
 obj-$(CONFIG_INPUT_GP2A)		+= gp2ap002a00f.o
 obj-$(CONFIG_INPUT_GPIO_TILT_POLLED)	+= gpio_tilt_polled.o
+obj-$(CONFIG_INPUT_REGULATOR_HAPTIC)	+= regulator-haptic.o
 obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
 obj-$(CONFIG_INPUT_IMS_PCU)		+= ims-pcu.o
 obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o
diff --git a/drivers/input/misc/regulator-haptic.c b/drivers/input/misc/regulator-haptic.c
new file mode 100644
index 00000000000..1cdde981cdd
--- /dev/null
+++ b/drivers/input/misc/regulator-haptic.c
@@ -0,0 +1,227 @@
+/*
+ * Regulator haptic driver
+ *
+ * Copyright (c) 2013 Samsung Electronics Co., Ltd.
+ *
+ * Author: Hyunhee Kim <hyunhee.kim@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/slab.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of.h>
+
+#define MAX_MAGNITUDE		0xffff
+#define DEFAULT_MIN_MICROVOLT	1100000
+#define DEFAULT_MAX_MICROVOLT	2700000
+
+/*
+ * struct regulator
+ *
+ * One for each consumer device.
+ */
+struct regulator_haptic {
+	struct device *dev;
+	struct input_dev *input_dev;
+	struct work_struct work;
+	bool enabled;
+	struct regulator *regulator;
+	struct mutex mutex;
+	int max_mV;
+	int min_mV;
+	int intensity; /* mV */
+	int level;
+};
+
+static void regulator_haptic_enable(
+			struct regulator_haptic *haptic, bool enable)
+{
+	int ret;
+
+	mutex_lock(&haptic->mutex);
+	if (enable && !haptic->enabled) {
+		haptic->enabled = true;
+		ret = regulator_enable(haptic->regulator);
+		if (ret)
+			dev_err(haptic->dev, "failed to enable regulator\n");
+	} else if (!enable && haptic->enabled) {
+		haptic->enabled = false;
+		ret = regulator_disable(haptic->regulator);
+		if (ret)
+			dev_err(haptic->dev, "failed to disable regulator\n");
+	}
+
+	if (haptic->enabled)
+		regulator_set_voltage(haptic->regulator,
+			haptic->intensity * 1000, haptic->max_mV * 1000);
+
+	mutex_unlock(&haptic->mutex);
+}
+
+static void regulator_haptic_work(struct work_struct *work)
+{
+	struct regulator_haptic *haptic = container_of(work,
+						       struct regulator_haptic,
+						       work);
+	if (haptic->level)
+		regulator_haptic_enable(haptic, true);
+	else
+		regulator_haptic_enable(haptic, false);
+
+}
+
+static int regulator_haptic_play(struct input_dev *input, void *data,
+				struct ff_effect *effect)
+{
+	struct regulator_haptic *haptic = input_get_drvdata(input);
+
+	haptic->level = effect->u.rumble.strong_magnitude;
+	if (!haptic->level)
+		haptic->level = effect->u.rumble.weak_magnitude;
+
+	haptic->intensity =
+		(haptic->max_mV - haptic->min_mV) * haptic->level /
+		MAX_MAGNITUDE;
+	haptic->intensity = haptic->intensity + haptic->min_mV;
+
+	if (haptic->intensity > haptic->max_mV)
+		haptic->intensity = haptic->max_mV;
+	if (haptic->intensity < haptic->min_mV)
+		haptic->intensity = haptic->min_mV;
+
+	schedule_work(&haptic->work);
+
+	return 0;
+}
+
+static void regulator_haptic_close(struct input_dev *input)
+{
+	struct regulator_haptic *haptic = input_get_drvdata(input);
+
+	cancel_work_sync(&haptic->work);
+	regulator_haptic_enable(haptic, false);
+}
+
+static void regulator_haptic_parse_dt(struct regulator_haptic *haptic,
+				struct device *dev)
+{
+	struct device_node *node = dev->of_node;
+	int max_uV, min_uV;
+
+	if (of_property_read_u32(node, "max-microvolt", &max_uV)) {
+		dev_err(haptic->dev, "unable to parse max-microvolt\n");
+		max_uV = DEFAULT_MAX_MICROVOLT;
+	}
+	if (of_property_read_u32(node, "min-microvolt", &min_uV)) {
+		dev_err(haptic->dev, "unable to parse min-microvolt\n");
+		min_uV = DEFAULT_MIN_MICROVOLT;
+	}
+
+	haptic->max_mV = max_uV / 1000;
+	haptic->min_mV = min_uV / 1000;
+
+}
+
+static int regulator_haptic_probe(struct platform_device *pdev)
+{
+	struct regulator_haptic *haptic;
+	struct input_dev *input_dev;
+	int error;
+
+	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
+	if (!haptic) {
+		dev_err(&pdev->dev, "unable to allocate memory for haptic\n");
+		return -ENOMEM;
+	}
+
+	input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!input_dev) {
+		dev_err(&pdev->dev, "unable to allocate memory\n");
+		return  -ENOMEM;
+	}
+
+	INIT_WORK(&haptic->work, regulator_haptic_work);
+	mutex_init(&haptic->mutex);
+	haptic->input_dev = input_dev;
+	haptic->dev = &pdev->dev;
+	haptic->regulator = devm_regulator_get(&pdev->dev, "haptic");
+	if (IS_ERR(haptic->regulator)) {
+		error = PTR_ERR(haptic->regulator);
+		dev_err(&pdev->dev, "unable to get regulator, err: %d\n",
+			error);
+		return error;
+	}
+
+	regulator_haptic_parse_dt(haptic, haptic->dev);
+	haptic->input_dev->name = "regulator:haptic";
+	haptic->input_dev->dev.parent = &pdev->dev;
+	haptic->input_dev->close = regulator_haptic_close;
+	haptic->enabled = false;
+	input_set_drvdata(haptic->input_dev, haptic);
+	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
+
+	error = input_ff_create_memless(input_dev, NULL,
+				      regulator_haptic_play);
+	if (error) {
+		dev_err(&pdev->dev,
+			"input_ff_create_memless() failed: %d\n",
+			error);
+		goto err_put_regulator;
+	}
+
+	error = input_register_device(haptic->input_dev);
+	if (error) {
+		dev_err(&pdev->dev,
+			"couldn't register input device: %d\n",
+			error);
+		goto err_destroy_ff;
+	}
+
+	platform_set_drvdata(pdev, haptic);
+
+	return 0;
+
+err_destroy_ff:
+	input_ff_destroy(haptic->input_dev);
+err_put_regulator:
+	regulator_put(haptic->regulator);
+
+	return error;
+}
+
+static int regulator_haptic_remove(struct platform_device *pdev)
+{
+	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
+
+	input_unregister_device(haptic->input_dev);
+	devm_regulator_put(haptic->regulator);
+
+	return 0;
+}
+
+static struct of_device_id regulator_haptic_dt_match[] = {
+	{ .compatible = "linux,regulator-haptic" },
+	{},
+};
+
+static struct platform_driver regulator_haptic_driver = {
+	.driver		= {
+		.name	= "regulator-haptic",
+		.owner	= THIS_MODULE,
+		.of_match_table = regulator_haptic_dt_match,
+	},
+	.probe		= regulator_haptic_probe,
+	.remove		= regulator_haptic_remove,
+};
+module_platform_driver(regulator_haptic_driver);
+
+MODULE_ALIAS("platform:regulator-haptic");
+MODULE_DESCRIPTION("Regulator haptic driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@samsung.com>");