Input: add haptic driver on max77693

This driver to supports the haptic controller on MAX77693 Multifunction
device with PMIC, CHARGER, LED, MUIC, HAPTIC.

This driver supports external pwm and LRA (Linear Resonant Actuator) motor.
User can control the haptic device via force feedback framework.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

3 files changed, 369 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 36382e5b7703..23297ab6163f 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -144,6 +144,17 @@ config INPUT_M68K_BEEP
 	tristate "M68k Beeper support"
 	depends on M68K
 
+config INPUT_MAX77693_HAPTIC
+	tristate "MAXIM MAX77693 haptic controller support"
+	depends on MFD_MAX77693 && PWM
+	select INPUT_FF_MEMLESS
+	help
+	  This option enables support for the haptic controller on
+	  MAXIM MAX77693 chip.
+
+	  To compile this driver as module, choose M here: the
+	  module will be called max77693-haptic.
+
 config INPUT_MAX8925_ONKEY
 	tristate "MAX8925 ONKEY support"
 	depends on MFD_MAX8925
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index e8b84d2c845f..19c760361f80 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -37,6 +37,7 @@ obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
 obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
+obj-$(CONFIG_INPUT_MAX77693_HAPTIC)	+= max77693-haptic.o
 obj-$(CONFIG_INPUT_MAX8925_ONKEY)	+= max8925_onkey.o
 obj-$(CONFIG_INPUT_MAX8997_HAPTIC)	+= max8997_haptic.o
 obj-$(CONFIG_INPUT_MC13783_PWRBUTTON)	+= mc13783-pwrbutton.o
diff --git a/drivers/input/misc/max77693-haptic.c b/drivers/input/misc/max77693-haptic.c
new file mode 100644
index 000000000000..d605db4d2f39
--- /dev/null
+++ b/drivers/input/misc/max77693-haptic.c
@@ -0,0 +1,357 @@
+/*
+ * MAXIM MAX77693 Haptic device driver
+ *
+ * Copyright (C) 2014 Samsung Electronics
+ * Jaewon Kim <jaewon02.kim@samsung.com>
+ *
+ * This program is not provided / owned by Maxim Integrated Products.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/input.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+#include <linux/regulator/consumer.h>
+#include <linux/mfd/max77693.h>
+#include <linux/mfd/max77693-private.h>
+
+#define MAX_MAGNITUDE_SHIFT	16
+
+enum max77693_haptic_motor_type {
+	MAX77693_HAPTIC_ERM = 0,
+	MAX77693_HAPTIC_LRA,
+};
+
+enum max77693_haptic_pulse_mode {
+	MAX77693_HAPTIC_EXTERNAL_MODE = 0,
+	MAX77693_HAPTIC_INTERNAL_MODE,
+};
+
+enum max77693_haptic_pwm_divisor {
+	MAX77693_HAPTIC_PWM_DIVISOR_32 = 0,
+	MAX77693_HAPTIC_PWM_DIVISOR_64,
+	MAX77693_HAPTIC_PWM_DIVISOR_128,
+	MAX77693_HAPTIC_PWM_DIVISOR_256,
+};
+
+struct max77693_haptic {
+	struct regmap *regmap_pmic;
+	struct regmap *regmap_haptic;
+	struct device *dev;
+	struct input_dev *input_dev;
+	struct pwm_device *pwm_dev;
+	struct regulator *motor_reg;
+
+	bool enabled;
+	bool suspend_state;
+	unsigned int magnitude;
+	unsigned int pwm_duty;
+	enum max77693_haptic_motor_type type;
+	enum max77693_haptic_pulse_mode mode;
+	enum max77693_haptic_pwm_divisor pwm_divisor;
+
+	struct work_struct work;
+};
+
+static int max77693_haptic_set_duty_cycle(struct max77693_haptic *haptic)
+{
+	int delta = (haptic->pwm_dev->period + haptic->pwm_duty) / 2;
+	int error;
+
+	error = pwm_config(haptic->pwm_dev, delta, haptic->pwm_dev->period);
+	if (error) {
+		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int max77693_haptic_configure(struct max77693_haptic *haptic,
+				     bool enable)
+{
+	unsigned int value;
+	int error;
+
+	value = ((haptic->type << MAX77693_CONFIG2_MODE) |
+		(enable << MAX77693_CONFIG2_MEN) |
+		(haptic->mode << MAX77693_CONFIG2_HTYP) |
+		(haptic->pwm_divisor));
+
+	error = regmap_write(haptic->regmap_haptic,
+			     MAX77693_HAPTIC_REG_CONFIG2, value);
+	if (error) {
+		dev_err(haptic->dev,
+			"failed to update haptic config: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int max77693_haptic_lowsys(struct max77693_haptic *haptic, bool enable)
+{
+	int error;
+
+	error = regmap_update_bits(haptic->regmap_pmic,
+				   MAX77693_PMIC_REG_LSCNFG,
+				   MAX77693_PMIC_LOW_SYS_MASK,
+				   enable << MAX77693_PMIC_LOW_SYS_SHIFT);
+	if (error) {
+		dev_err(haptic->dev, "cannot update pmic regmap: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static void max77693_haptic_enable(struct max77693_haptic *haptic)
+{
+	int error;
+
+	if (haptic->enabled)
+		return;
+
+	error = pwm_enable(haptic->pwm_dev);
+	if (error) {
+		dev_err(haptic->dev,
+			"failed to enable haptic pwm device: %d\n", error);
+		return;
+	}
+
+	error = max77693_haptic_lowsys(haptic, true);
+	if (error)
+		goto err_enable_lowsys;
+
+	error = max77693_haptic_configure(haptic, true);
+	if (error)
+		goto err_enable_config;
+
+	haptic->enabled = true;
+
+	return;
+
+err_enable_config:
+	max77693_haptic_lowsys(haptic, false);
+err_enable_lowsys:
+	pwm_disable(haptic->pwm_dev);
+}
+
+static void max77693_haptic_disable(struct max77693_haptic *haptic)
+{
+	int error;
+
+	if (haptic->enabled)
+		return;
+
+	error = max77693_haptic_configure(haptic, false);
+	if (error)
+		return;
+
+	error = max77693_haptic_lowsys(haptic, false);
+	if (error)
+		goto err_disable_lowsys;
+
+	pwm_disable(haptic->pwm_dev);
+	haptic->enabled = false;
+
+	return;
+
+err_disable_lowsys:
+	max77693_haptic_configure(haptic, true);
+}
+
+static void max77693_haptic_play_work(struct work_struct *work)
+{
+	struct max77693_haptic *haptic =
+			container_of(work, struct max77693_haptic, work);
+	int error;
+
+	error = max77693_haptic_set_duty_cycle(haptic);
+	if (error) {
+		dev_err(haptic->dev, "failed to set duty cycle: %d\n", error);
+		return;
+	}
+
+	if (haptic->magnitude)
+		max77693_haptic_enable(haptic);
+	else
+		max77693_haptic_disable(haptic);
+}
+
+static int max77693_haptic_play_effect(struct input_dev *dev, void *data,
+				       struct ff_effect *effect)
+{
+	struct max77693_haptic *haptic = input_get_drvdata(dev);
+	uint64_t period_mag_multi;
+
+	haptic->magnitude = effect->u.rumble.strong_magnitude;
+	if (!haptic->magnitude)
+		haptic->magnitude = effect->u.rumble.weak_magnitude;
+
+	/*
+	 * The magnitude comes from force-feedback interface.
+	 * The formula to convert magnitude to pwm_duty as follows:
+	 * - pwm_duty = (magnitude * pwm_period) / MAX_MAGNITUDE(0xFFFF)
+	 */
+	period_mag_multi = (int64_t)(haptic->pwm_dev->period *
+						haptic->magnitude);
+	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
+						MAX_MAGNITUDE_SHIFT);
+
+	schedule_work(&haptic->work);
+
+	return 0;
+}
+
+static int max77693_haptic_open(struct input_dev *dev)
+{
+	struct max77693_haptic *haptic = input_get_drvdata(dev);
+	int error;
+
+	error = regulator_enable(haptic->motor_reg);
+	if (error) {
+		dev_err(haptic->dev,
+			"failed to enable regulator: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static void max77693_haptic_close(struct input_dev *dev)
+{
+	struct max77693_haptic *haptic = input_get_drvdata(dev);
+	int error;
+
+	cancel_work_sync(&haptic->work);
+	max77693_haptic_disable(haptic);
+
+	error = regulator_disable(haptic->motor_reg);
+	if (error)
+		dev_err(haptic->dev,
+			"failed to disable regulator: %d\n", error);
+}
+
+static int max77693_haptic_probe(struct platform_device *pdev)
+{
+	struct max77693_dev *max77693 = dev_get_drvdata(pdev->dev.parent);
+	struct max77693_haptic *haptic;
+	int error;
+
+	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
+	if (!haptic)
+		return -ENOMEM;
+
+	haptic->regmap_pmic = max77693->regmap;
+	haptic->regmap_haptic = max77693->regmap_haptic;
+	haptic->dev = &pdev->dev;
+	haptic->type = MAX77693_HAPTIC_LRA;
+	haptic->mode = MAX77693_HAPTIC_EXTERNAL_MODE;
+	haptic->pwm_divisor = MAX77693_HAPTIC_PWM_DIVISOR_128;
+	haptic->suspend_state = false;
+
+	INIT_WORK(&haptic->work, max77693_haptic_play_work);
+
+	/* Get pwm and regulatot for haptic device */
+	haptic->pwm_dev = devm_pwm_get(&pdev->dev, NULL);
+	if (IS_ERR(haptic->pwm_dev)) {
+		dev_err(&pdev->dev, "failed to get pwm device\n");
+		return PTR_ERR(haptic->pwm_dev);
+	}
+
+	haptic->motor_reg = devm_regulator_get(&pdev->dev, "haptic");
+	if (IS_ERR(haptic->motor_reg)) {
+		dev_err(&pdev->dev, "failed to get regulator\n");
+		return PTR_ERR(haptic->motor_reg);
+	}
+
+	/* Initialize input device for haptic device */
+	haptic->input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!haptic->input_dev) {
+		dev_err(&pdev->dev, "failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	haptic->input_dev->name = "max77693-haptic";
+	haptic->input_dev->id.version = 1;
+	haptic->input_dev->dev.parent = &pdev->dev;
+	haptic->input_dev->open = max77693_haptic_open;
+	haptic->input_dev->close = max77693_haptic_close;
+	input_set_drvdata(haptic->input_dev, haptic);
+	input_set_capability(haptic->input_dev, EV_FF, FF_RUMBLE);
+
+	error = input_ff_create_memless(haptic->input_dev, NULL,
+				max77693_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;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int max77693_haptic_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
+
+	if (haptic->enabled) {
+		max77693_haptic_disable(haptic);
+		haptic->suspend_state = true;
+	}
+
+	return 0;
+}
+
+static int max77693_haptic_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct max77693_haptic *haptic = platform_get_drvdata(pdev);
+
+	if (haptic->suspend_state) {
+		max77693_haptic_enable(haptic);
+		haptic->suspend_state = false;
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(max77693_haptic_pm_ops,
+			 max77693_haptic_suspend, max77693_haptic_resume);
+
+static struct platform_driver max77693_haptic_driver = {
+	.driver		= {
+		.name	= "max77693-haptic",
+		.owner	= THIS_MODULE,
+		.pm	= &max77693_haptic_pm_ops,
+	},
+	.probe		= max77693_haptic_probe,
+};
+module_platform_driver(max77693_haptic_driver);
+
+MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
+MODULE_DESCRIPTION("MAXIM MAX77693 Haptic driver");
+MODULE_ALIAS("platform:max77693-haptic");
+MODULE_LICENSE("GPL");