[PATCH 1/2] Input: add regulator haptic driver

[Jaewon Kim]

This patch adds support for haptic driver controlled by
voltage of regulator. And this driver support for
Force Feedback interface from input framework

Signed-off-by: Jaewon Kim <jaewon02.kim@xxxxxxxxxxx>
Signed-off-by: Hyunhee Kim <hyunhee.kim@xxxxxxxxxxx>
Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
 .../devicetree/bindings/input/regulator-haptic.txt |   24 ++
 drivers/input/misc/Kconfig                         |   11 +
 drivers/input/misc/Makefile                        |    1 +
 drivers/input/misc/regulator-haptic.c              |  241 ++++++++++++++++++++
 4 files changed, 277 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/input/regulator-haptic.txt
 create mode 100644 drivers/input/misc/regulator-haptic.c

diff --git a/Documentation/devicetree/bindings/input/regulator-haptic.txt b/Documentation/devicetree/bindings/input/regulator-haptic.txt
new file mode 100644
index 0000000..9f60e17
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/regulator-haptic.txt
@@ -0,0 +1,24 @@
+* Requlator Haptic Device Tree Bindings
+
+The regulator haptic driver controlled by voltage of regulator.
+This driver implemented via Force Feedback interface.
+
+Required Properties:
+ - compatible : Should be "regulator-haptic"
+ - haptic-supply : Power supply for the haptic motor.
+	[*] refer Documentation/devicetree/bindings/regulator/regulator.txt
+
+ - max-microvolt : The maximum voltage value supplied to haptic motor.
+		[The unit of the voltage is a micro]
+
+ - min-microvolt : The minimum voltage value in which haptic motor reacts.
+		[The unit of the voltage is a micro]
+
+Example:
+
+	regulator-haptic {
+		compatible = "regulator-haptic";
+		haptic-supply = <&motor_regulator>;
+		max-microvolt = <2700000>;
+		min-microvolt = <1100000>;
+	};
diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 23297ab..e5e556d 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -394,6 +394,17 @@ config INPUT_CM109
 	  To compile this driver as a module, choose M here: the module will be
 	  called cm109.
 
+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_RETU_PWRBUTTON
 	tristate "Retu Power button Driver"
 	depends on MFD_RETU
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index 19c7603..1f135af 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -53,6 +53,7 @@ obj-$(CONFIG_INPUT_PMIC8XXX_PWRKEY)	+= pmic8xxx-pwrkey.o
 obj-$(CONFIG_INPUT_POWERMATE)		+= powermate.o
 obj-$(CONFIG_INPUT_PWM_BEEPER)		+= pwm-beeper.o
 obj-$(CONFIG_INPUT_RB532_BUTTON)	+= rb532_button.o
+obj-$(CONFIG_INPUT_REGULATOR_HAPTIC)	+= regulator-haptic.o
 obj-$(CONFIG_INPUT_RETU_PWRBUTTON)	+= retu-pwrbutton.o
 obj-$(CONFIG_INPUT_GPIO_ROTARY_ENCODER)	+= rotary_encoder.o
 obj-$(CONFIG_INPUT_SGI_BTNS)		+= sgi_btns.o
diff --git a/drivers/input/misc/regulator-haptic.c b/drivers/input/misc/regulator-haptic.c
new file mode 100644
index 0000000..1a83ecb
--- /dev/null
+++ b/drivers/input/misc/regulator-haptic.c
@@ -0,0 +1,241 @@
+/*
+ * Regulator haptic driver
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Author: Jaewon Kim <jaewon02.kim@xxxxxxxxxxx>
+ * Author: Hyunhee Kim <hyunhee.kim@xxxxxxxxxxx>
+ *
+ * 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_SHIFT	16
+
+struct regulator_haptic {
+	struct device *dev;
+	struct input_dev *input_dev;
+	struct regulator *regulator;
+	struct work_struct work;
+
+	bool enabled;
+	bool suspend_state;
+	unsigned int max_volt;
+	unsigned int min_volt;
+	unsigned int intensity;
+	unsigned int magnitude;
+};
+
+static void regulator_haptic_enable(struct regulator_haptic *haptic)
+{
+	int error;
+
+	if (haptic->enabled)
+		return;
+
+	error = regulator_enable(haptic->regulator);
+	if (error) {
+		dev_err(haptic->dev, "cannot enable regulator\n");
+		return;
+	}
+
+	haptic->enabled = true;
+}
+
+static void regulator_haptic_disable(struct regulator_haptic *haptic)
+{
+	int error;
+
+	if (!haptic->enabled)
+		return;
+
+	error = regulator_disable(haptic->regulator);
+	if (error) {
+		dev_err(haptic->dev, "cannot disable regulator\n");
+		return;
+	}
+
+	haptic->enabled = false;
+}
+
+static void regulator_haptic_work(struct work_struct *work)
+{
+	struct regulator_haptic *haptic = container_of(work,
+					struct regulator_haptic, work);
+	int error;
+
+	error = regulator_set_voltage(haptic->regulator,
+			haptic->intensity + haptic->min_volt, haptic->max_volt);
+	if (error) {
+		dev_err(haptic->dev, "cannot set regulator voltage\n");
+		return;
+	}
+
+	if (haptic->magnitude)
+		regulator_haptic_enable(haptic);
+	else
+		regulator_haptic_disable(haptic);
+}
+
+static int regulator_haptic_play_effect(struct input_dev *input, void *data,
+					struct ff_effect *effect)
+{
+	struct regulator_haptic *haptic = input_get_drvdata(input);
+	u64 volt_mag_multi;
+
+	haptic->magnitude = effect->u.rumble.strong_magnitude;
+	if (!haptic->magnitude)
+		haptic->magnitude = effect->u.rumble.weak_magnitude;
+
+
+	volt_mag_multi = (u64)(haptic->max_volt - haptic->min_volt) *
+					haptic->magnitude;
+	haptic->intensity = (unsigned int)(volt_mag_multi >>
+					MAX_MAGNITUDE_SHIFT);
+
+	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_disable(haptic);
+}
+
+static int regulator_haptic_parse_dt(struct regulator_haptic *haptic)
+{
+	struct device_node *node = haptic->dev->of_node;
+	int error;
+
+	error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
+	if (error) {
+		dev_err(haptic->dev, "cannot parse max-microvolt\n");
+		return error;
+	}
+
+	error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
+	if (error) {
+		dev_err(haptic->dev, "cannot parse min-microvolt\n");
+		return error;
+	}
+
+	return 0;
+}
+
+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)
+		return -ENOMEM;
+
+	haptic->dev = &pdev->dev;
+	haptic->enabled = false;
+	haptic->suspend_state = false;
+	INIT_WORK(&haptic->work, regulator_haptic_work);
+
+	error = regulator_haptic_parse_dt(haptic);
+	if (error) {
+		dev_err(&pdev->dev, "failed to parse device tree\n");
+		return error;
+	}
+
+	haptic->regulator = devm_regulator_get(&pdev->dev, "haptic");
+	if (IS_ERR(haptic->regulator)) {
+		dev_err(&pdev->dev, "failed to get regulator\n");
+		return PTR_ERR(haptic->regulator);
+	}
+
+	input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!input_dev)
+		return  -ENOMEM;
+
+	haptic->input_dev = input_dev;
+	haptic->input_dev->name = "regulator-haptic";
+	haptic->input_dev->dev.parent = &pdev->dev;
+	haptic->input_dev->close = regulator_haptic_close;
+	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_effect);
+	if (error) {
+		dev_err(&pdev->dev, "failed to create force-feedback\n");
+		return error;
+	}
+
+	error = input_register_device(haptic->input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register input device\n");
+		return error;
+	}
+
+	platform_set_drvdata(pdev, haptic);
+
+	return 0;
+}
+
+static int __maybe_unused regulator_haptic_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
+
+	if (haptic->enabled) {
+		regulator_haptic_disable(haptic);
+		haptic->suspend_state = true;
+	}
+
+	return 0;
+}
+
+static int __maybe_unused regulator_haptic_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct regulator_haptic *haptic = platform_get_drvdata(pdev);
+
+	if (haptic->enabled) {
+		regulator_haptic_enable(haptic);
+		haptic->suspend_state = false;
+	}
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
+		regulator_haptic_suspend, regulator_haptic_resume);
+
+static struct of_device_id regulator_haptic_dt_match[] = {
+	{ .compatible = "regulator-haptic" },
+	{},
+};
+
+static struct platform_driver regulator_haptic_driver = {
+	.probe		= regulator_haptic_probe,
+	.driver		= {
+		.name		= "regulator-haptic",
+		.owner		= THIS_MODULE,
+		.of_match_table = regulator_haptic_dt_match,
+		.pm		= &regulator_haptic_pm_ops,
+	},
+};
+module_platform_driver(regulator_haptic_driver);
+
+MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@xxxxxxxxxxx>");
+MODULE_AUTHOR("Hyunhee Kim <hyunhee.kim@xxxxxxxxxxx>");
+MODULE_ALIAS("platform:regulator-haptic");
+MODULE_DESCRIPTION("Regulator haptic driver");
+MODULE_LICENSE("GPL");
-- 
1.7.9.5

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