[v3,13/23] input: add max77705 haptic driver

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 6ba984d7f0b1..26f7b25a0b42 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -233,6 +233,17 @@  config INPUT_MAX77693_HAPTIC
 	  To compile this driver as module, choose M here: the
 	  module will be called max77693-haptic.
 
+config INPUT_MAX77705_HAPTIC
+	tristate "MAXIM MAX77705 haptic controller support"
+	depends on MFD_MAX77705 && PWM
+	select INPUT_FF_MEMLESS
+	help
+	  This option enables support for the haptic controller on
+	  MAXIM MAX77705 chip.
+
+	  To compile this driver as module, choose M here: the
+	  module will be called max77705-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 04296a4abe8e..4dea2720b757 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -51,6 +51,7 @@  obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
 obj-$(CONFIG_INPUT_M68K_BEEP)		+= m68kspkr.o
 obj-$(CONFIG_INPUT_MAX77650_ONKEY)	+= max77650-onkey.o
 obj-$(CONFIG_INPUT_MAX77693_HAPTIC)	+= max77693-haptic.o
+obj-$(CONFIG_INPUT_MAX77705_HAPTIC)	+= max77705-haptic.o
 obj-$(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/max77705-haptic.c b/drivers/input/misc/max77705-haptic.c
new file mode 100644
index 000000000000..e92dcb4fff37
--- /dev/null
+++ b/drivers/input/misc/max77705-haptic.c
@@ -0,0 +1,378 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Based on max77693-haptic.c:
+ *	Copyright (C) 2014,2015 Samsung Electronics
+ *      Jaewon Kim <jaewon02.kim@samsung.com>
+ *      Krzysztof Kozlowski <krzk@kernel.org>
+ *
+ * Copyright (C) 2024 Dzmitry Sankouski <dsankouski@gmail.com>
+ *
+ * This program is not provided / owned by Maxim Integrated Products.
+ */
+
+#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/max77705.h>
+#include <linux/mfd/max77705-private.h>
+
+#define MAX_MAGNITUDE_SHIFT	16
+
+enum max77705_haptic_motor_type {
+	MAX77705_HAPTIC_ERM = 0,
+	MAX77705_HAPTIC_LRA,
+};
+
+enum max77705_haptic_pulse_mode {
+	MAX77705_HAPTIC_EXTERNAL_MODE = 0,
+	MAX77705_HAPTIC_INTERNAL_MODE,
+};
+
+enum max77705_haptic_pwm_divisor {
+	MAX77705_HAPTIC_PWM_DIVISOR_32 = 0,
+	MAX77705_HAPTIC_PWM_DIVISOR_64,
+	MAX77705_HAPTIC_PWM_DIVISOR_128,
+	MAX77705_HAPTIC_PWM_DIVISOR_256,
+};
+
+struct max77705_haptic {
+	enum max77705_types dev_type;
+
+	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 max77705_haptic_motor_type type;
+	enum max77705_haptic_pulse_mode mode;
+
+	struct work_struct work;
+};
+
+static int max77705_haptic_set_duty_cycle(struct max77705_haptic *haptic)
+{
+	struct pwm_args pargs;
+	int delta;
+	int error;
+
+	pwm_get_args(haptic->pwm_dev, &pargs);
+	delta = (pargs.period + haptic->pwm_duty) / 2;
+	error = pwm_config(haptic->pwm_dev, delta, pargs.period);
+	if (error) {
+		dev_err(haptic->dev, "failed to configure pwm: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int max77705_haptic_bias(struct max77705_haptic *haptic, bool on)
+{
+	int error;
+
+	error = regmap_update_bits(haptic->regmap_haptic,
+							   MAX77705_PMIC_REG_MAINCTRL1,
+							   MAX77705_MAINCTRL1_BIASEN_MASK,
+							   on << MAX77705_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 max77705_haptic_configure(struct max77705_haptic *haptic,
+				     bool enable)
+{
+	unsigned int value, config_reg;
+	int error;
+
+	value = ((haptic->type << MAX77705_CONFIG2_MODE_SHIFT) |
+		(enable << MAX77705_CONFIG2_MEN_SHIFT) |
+		(haptic->mode << MAX77705_CONFIG2_HTYP_SHIFT) |
+		MAX77705_HAPTIC_PWM_DIVISOR_128);
+	config_reg = MAX77705_PMIC_REG_MCONFIG;
+
+	error = regmap_write(haptic->regmap_haptic,
+			     config_reg, value);
+	if (error) {
+		dev_err(haptic->dev,
+			"failed to update haptic config: %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+
+static void max77705_haptic_enable(struct max77705_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 = max77705_haptic_configure(haptic, true);
+	if (error)
+		goto err_enable_config;
+
+	haptic->enabled = true;
+
+	return;
+
+err_enable_config:
+	pwm_disable(haptic->pwm_dev);
+}
+
+static void max77705_haptic_disable(struct max77705_haptic *haptic)
+{
+	int error;
+
+	if (!haptic->enabled)
+		return;
+
+	error = max77705_haptic_configure(haptic, false);
+	if (error)
+		return;
+
+	pwm_disable(haptic->pwm_dev);
+	haptic->enabled = false;
+}
+
+static void max77705_haptic_play_work(struct work_struct *work)
+{
+	struct max77705_haptic *haptic =
+			container_of(work, struct max77705_haptic, work);
+	int error;
+
+	error = max77705_haptic_set_duty_cycle(haptic);
+	if (error) {
+		dev_err(haptic->dev, "failed to set duty cycle: %d\n", error);
+		return;
+	}
+
+	if (haptic->magnitude)
+		max77705_haptic_enable(haptic);
+	else
+		max77705_haptic_disable(haptic);
+}
+
+static int max77705_haptic_play_effect(struct input_dev *dev, void *data,
+				       struct ff_effect *effect)
+{
+	struct max77705_haptic *haptic = input_get_drvdata(dev);
+	struct pwm_args pargs;
+	u64 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)
+	 */
+	pr_info("magnitude: %d(%x)", haptic->magnitude, haptic->magnitude);
+	pwm_get_args(haptic->pwm_dev, &pargs);
+	period_mag_multi = (u64)pargs.period * haptic->magnitude;
+	haptic->pwm_duty = (unsigned int)(period_mag_multi >>
+						MAX_MAGNITUDE_SHIFT);
+
+	schedule_work(&haptic->work);
+
+	return 0;
+}
+
+static int max77705_haptic_open(struct input_dev *dev)
+{
+	struct max77705_haptic *haptic = input_get_drvdata(dev);
+	int error;
+
+	error = max77705_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 max77705_haptic_close(struct input_dev *dev)
+{
+	struct max77705_haptic *haptic = input_get_drvdata(dev);
+	int error;
+
+	cancel_work_sync(&haptic->work);
+	max77705_haptic_disable(haptic);
+
+	error = regulator_disable(haptic->motor_reg);
+	if (error)
+		dev_err(haptic->dev,
+			"failed to disable regulator: %d\n", error);
+
+	max77705_haptic_bias(haptic, false);
+}
+
+static int max77705_haptic_probe(struct platform_device *pdev)
+{
+	struct max77705_dev *max77705 = dev_get_drvdata(pdev->dev.parent);
+	struct max77705_haptic *haptic;
+	int error;
+
+	haptic = devm_kzalloc(&pdev->dev, sizeof(*haptic), GFP_KERNEL);
+	if (!haptic)
+		return -ENOMEM;
+
+	haptic->regmap_pmic = max77705->regmap;
+	haptic->dev = &pdev->dev;
+	haptic->type = MAX77705_HAPTIC_LRA;
+	haptic->mode = MAX77705_HAPTIC_EXTERNAL_MODE;
+	haptic->suspend_state = false;
+
+	/* Variant-specific init */
+	haptic->dev_type = max77705->type;
+	haptic->regmap_haptic = max77705->regmap;
+
+	INIT_WORK(&haptic->work, max77705_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);
+	}
+
+	/*
+	 * FIXME: pwm_apply_args() should be removed when switching to the
+	 * atomic PWM API.
+	 */
+	pwm_apply_args(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 = "max77705-haptic";
+	haptic->input_dev->id.version = 1;
+	haptic->input_dev->dev.parent = &pdev->dev;
+	haptic->input_dev->open = max77705_haptic_open;
+	haptic->input_dev->close = max77705_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,
+				max77705_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 void max77705_haptic_remove(struct platform_device *pdev)
+{
+	struct max77705_haptic *haptic = platform_get_drvdata(pdev);
+
+	if (haptic->enabled)
+		max77705_haptic_disable(haptic);
+}
+
+static int max77705_haptic_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct max77705_haptic *haptic = platform_get_drvdata(pdev);
+
+	if (haptic->enabled) {
+		max77705_haptic_disable(haptic);
+		haptic->suspend_state = true;
+	}
+
+	return 0;
+}
+
+static int max77705_haptic_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct max77705_haptic *haptic = platform_get_drvdata(pdev);
+
+	if (haptic->suspend_state) {
+		max77705_haptic_enable(haptic);
+		haptic->suspend_state = false;
+	}
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(max77705_haptic_pm_ops,
+				max77705_haptic_suspend,
+				max77705_haptic_resume);
+
+static const struct of_device_id of_max77705_haptic_dt_match[] = {
+	{ .compatible = "maxim,max77705-haptic", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, of_max77705_haptic_dt_match);
+
+static struct platform_driver max77705_haptic_driver = {
+	.driver		= {
+		.name	= "max77705-haptic",
+		.pm	= pm_sleep_ptr(&max77705_haptic_pm_ops),
+		.of_match_table = of_max77705_haptic_dt_match,
+	},
+	.probe		= max77705_haptic_probe,
+	.remove_new	= max77705_haptic_remove,
+};
+module_platform_driver(max77705_haptic_driver);
+
+MODULE_AUTHOR("Dzmitry Sankouski <dsankouski@gmail.com>");
+MODULE_AUTHOR("Jaewon Kim <jaewon02.kim@samsung.com>");
+MODULE_AUTHOR("Krzysztof Kozlowski <krzk@kernel.org>");
+MODULE_DESCRIPTION("MAXIM 77705/77705 Haptic driver");
+MODULE_LICENSE("GPL");