Input: add haptic support for max77843

This patch adds support for haptic on max77843 MFD (Multi Function Device)
with PMIC, MUIC, LED, CHARGER.

This driver supports external pwm and LRA (Linear Resonant Actuator) motor.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
[Jim Davis <jim.epost@gmail.com>: should depend on REGULATOR not PWM]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

3 files changed, 371 insertions, 0 deletions

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 6deb8dae3205..ef542f7ad944 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -165,6 +165,18 @@ config INPUT_MAX77693_HAPTIC
 	  To compile this driver as module, choose M here: the
 	  module will be called max77693-haptic.
 
+config INPUT_MAX77843_HAPTIC
+    tristate "MAXIM MAX77843 haptic controller support"
+    depends on MFD_MAX77843 && REGULATOR
+    select INPUT_FF_MEMLESS
+    help
+      This option enables support for the haptic controller on
+      MAXIM MAX77843 chip. The driver supports ff-memless interface
+      from input framework.
+
+      To compile this driver as module, choose M here: the
+      module will be called max77843-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 403a1a54a76c..75b58841d5a7 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -39,6 +39,7 @@ 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-$(CONFIG_INPUT_MAX77843_HAPTIC)	+= max77843-haptic.o
 obj-$(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/max77843-haptic.c b/drivers/input/misc/max77843-haptic.c
new file mode 100644
index 000000000000..dccbb465a055
--- /dev/null
+++ b/drivers/input/misc/max77843-haptic.c
@@ -0,0 +1,358 @@
+/*
+ * MAXIM MAX77693 Haptic device driver
+ *
+ * Copyright (C) 2015 Samsung Electronics
+ * Author: Jaewon Kim <jaewon02.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 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/i2c.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/mfd/max77843-private.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define MAX_MAGNITUDE_SHIFT        16
+
+enum max77843_haptic_motor_type {
+	MAX77843_HAPTIC_ERM = 0,
+	MAX77843_HAPTIC_LRA,
+};
+
+enum max77843_haptic_pwm_divisor {
+	MAX77843_HAPTIC_PWM_DIVISOR_32 = 0,
+	MAX77843_HAPTIC_PWM_DIVISOR_64,
+	MAX77843_HAPTIC_PWM_DIVISOR_128,
+	MAX77843_HAPTIC_PWM_DIVISOR_256,
+};
+
+struct max77843_haptic {
+	struct regmap *regmap_haptic;
+	struct device *dev;
+	struct input_dev *input_dev;
+	struct pwm_device *pwm_dev;
+	struct regulator *motor_reg;
+	struct work_struct work;
+	struct mutex mutex;
+
+	unsigned int magnitude;
+	unsigned int pwm_duty;
+
+	bool active;
+	bool suspended;
+
+	enum max77843_haptic_motor_type type;
+	enum max77843_haptic_pwm_divisor pwm_divisor;
+};
+
+static int max77843_haptic_set_duty_cycle(struct max77843_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 max77843_haptic_bias(struct max77843_haptic *haptic, bool on)
+{
+	int error;
+
+	error = regmap_update_bits(haptic->regmap_haptic,
+				   MAX77843_SYS_REG_MAINCTRL1,
+				   MAX77843_MAINCTRL1_BIASEN_MASK,
+				   on << MAINCTRL1_BIASEN_SHIFT);
+	if (error) {
+		dev_err(haptic->dev, "failed to %s bias: %d\n",
+			on ? "enable" : "disable", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int max77843_haptic_config(struct max77843_haptic *haptic, bool enable)
+{
+	unsigned int value;
+	int error;
+
+	value = (haptic->type << MCONFIG_MODE_SHIFT) |
+		(enable << MCONFIG_MEN_SHIFT) |
+		(haptic->pwm_divisor << MCONFIG_PDIV_SHIFT);
+
+	error = regmap_write(haptic->regmap_haptic,
+			     MAX77843_HAP_REG_MCONFIG, value);
+	if (error) {
+		dev_err(haptic->dev,
+			"failed to update haptic config: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int max77843_haptic_enable(struct max77843_haptic *haptic)
+{
+	int error;
+
+	if (haptic->active)
+		return 0;
+
+	error = pwm_enable(haptic->pwm_dev);
+	if (error) {
+		dev_err(haptic->dev,
+			"failed to enable pwm device: %d\n", error);
+		return error;
+	}
+
+	error = max77843_haptic_config(haptic, true);
+	if (error)
+		goto err_config;
+
+	haptic->active = true;
+
+	return 0;
+
+err_config:
+	pwm_disable(haptic->pwm_dev);
+
+	return error;
+}
+
+static int max77843_haptic_disable(struct max77843_haptic *haptic)
+{
+	int error;
+
+	if (!haptic->active)
+		return 0;
+
+	error = max77843_haptic_config(haptic, false);
+	if (error)
+		return error;
+
+	pwm_disable(haptic->pwm_dev);
+
+	haptic->active = false;
+
+	return 0;
+}
+
+static void max77843_haptic_play_work(struct work_struct *work)
+{
+	struct max77843_haptic *haptic =
+			container_of(work, struct max77843_haptic, work);
+	int error;
+
+	mutex_lock(&haptic->mutex);
+
+	if (haptic->suspended)
+		goto out_unlock;
+
+	if (haptic->magnitude) {
+		error = max77843_haptic_set_duty_cycle(haptic);
+		if (error) {
+			dev_err(haptic->dev,
+				"failed to set duty cycle: %d\n", error);
+			goto out_unlock;
+		}
+
+		error = max77843_haptic_enable(haptic);
+		if (error)
+			dev_err(haptic->dev,
+				"cannot enable haptic: %d\n", error);
+	} else {
+		error = max77843_haptic_disable(haptic);
+		if (error)
+			dev_err(haptic->dev,
+				"cannot disable haptic: %d\n", error);
+	}
+
+out_unlock:
+	mutex_unlock(&haptic->mutex);
+}
+
+static int max77843_haptic_play_effect(struct input_dev *dev, void *data,
+		struct ff_effect *effect)
+{
+	struct max77843_haptic *haptic = input_get_drvdata(dev);
+	u64 period_mag_multi;
+
+	haptic->magnitude = effect->u.rumble.strong_magnitude;
+	if (!haptic->magnitude)
+		haptic->magnitude = effect->u.rumble.weak_magnitude;
+
+	period_mag_multi = (u64)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 max77843_haptic_open(struct input_dev *dev)
+{
+	struct max77843_haptic *haptic = input_get_drvdata(dev);
+	int error;
+
+	error = max77843_haptic_bias(haptic, true);
+	if (error)
+		return 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 max77843_haptic_close(struct input_dev *dev)
+{
+	struct max77843_haptic *haptic = input_get_drvdata(dev);
+	int error;
+
+	cancel_work_sync(&haptic->work);
+	max77843_haptic_disable(haptic);
+
+	error = regulator_disable(haptic->motor_reg);
+	if (error)
+		dev_err(haptic->dev,
+			"failed to disable regulator: %d\n", error);
+
+	max77843_haptic_bias(haptic, false);
+}
+
+static int max77843_haptic_probe(struct platform_device *pdev)
+{
+	struct max77843 *max77843 = dev_get_drvdata(pdev->dev.parent);
+	struct max77843_haptic *haptic;
+	int error;
+
+	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
+	if (!haptic)
+		return -ENOMEM;
+
+	haptic->regmap_haptic = max77843->regmap;
+	haptic->dev = &pdev->dev;
+	haptic->type = MAX77843_HAPTIC_LRA;
+	haptic->pwm_divisor = MAX77843_HAPTIC_PWM_DIVISOR_128;
+
+	INIT_WORK(&haptic->work, max77843_haptic_play_work);
+	mutex_init(&haptic->mutex);
+
+	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_exclusive(&pdev->dev, "haptic");
+	if (IS_ERR(haptic->motor_reg)) {
+		dev_err(&pdev->dev, "failed to get regulator\n");
+		return PTR_ERR(haptic->motor_reg);
+	}
+
+	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 = "max77843-haptic";
+	haptic->input_dev->id.version = 1;
+	haptic->input_dev->dev.parent = &pdev->dev;
+	haptic->input_dev->open = max77843_haptic_open;
+	haptic->input_dev->close = max77843_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,
+			max77843_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 max77843_haptic_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct max77843_haptic *haptic = platform_get_drvdata(pdev);
+	int error;
+
+	error = mutex_lock_interruptible(&haptic->mutex);
+	if (error)
+		return error;
+
+	max77843_haptic_disable(haptic);
+
+	haptic->suspended = true;
+
+	mutex_unlock(&haptic->mutex);
+
+	return 0;
+}
+
+static int __maybe_unused max77843_haptic_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct max77843_haptic *haptic = platform_get_drvdata(pdev);
+	unsigned int magnitude;
+
+	mutex_lock(&haptic->mutex);
+
+	haptic->suspended = false;
+
+	magnitude = ACCESS_ONCE(haptic->magnitude);
+	if (magnitude)
+		max77843_haptic_enable(haptic);
+
+	mutex_unlock(&haptic->mutex);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(max77843_haptic_pm_ops,
+		max77843_haptic_suspend, max77843_haptic_resume);
+
+static struct platform_driver max77843_haptic_driver = {
+	.driver		= {
+		.name	= "max77843-haptic",
+		.pm	= &max77843_haptic_pm_ops,
+	},
+	.probe		= max77843_haptic_probe,
+};
+module_platform_driver(max77843_haptic_driver);
+
+MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
+MODULE_DESCRIPTION("MAXIM MAX77843 Haptic driver");
+MODULE_LICENSE("GPL");