// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  PWM vibrator driver
 *
 *  Copyright (C) 2017 Collabora Ltd.
 *
 *  Based on previous work from:
 *  Copyright (C) 2012 Dmitry Torokhov <dmitry.torokhov@gmail.com>
 *
 *  Based on PWM beeper driver:
 *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
 */

#include <linux/gpio/consumer.h>
#include <linux/input.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/pwm.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>

struct pwm_vibrator {
 struct input_dev *input;
 struct gpio_desc *enable_gpio;
 struct pwm_device *pwm;
 struct pwm_device *pwm_dir;
 struct regulator *vcc;

 struct work_struct play_work;
 u16 level;
 u32 direction_duty_cycle;
 bool vcc_on;
};

static int pwm_vibrator_start(struct pwm_vibrator *vibrator)
{
 struct device *pdev = vibrator->input->dev.parent;
 struct pwm_state state;
 int err;

 if (!vibrator->vcc_on) {
  err = regulator_enable(vibrator->vcc);
  if (err) {
   dev_err(pdev, "failed to enable regulator: %d\n", err);
   return err;
  }
  vibrator->vcc_on = true;
 }

 gpiod_set_value_cansleep(vibrator->enable_gpio, 1);

 pwm_get_state(vibrator->pwm, &state);
 pwm_set_relative_duty_cycle(&state, vibrator->level, 0xffff);
 state.enabled = true;

 err = pwm_apply_might_sleep(vibrator->pwm, &state);
 if (err) {
  dev_err(pdev, "failed to apply pwm state: %d\n", err);
  return err;
 }

 if (vibrator->pwm_dir) {
  pwm_get_state(vibrator->pwm_dir, &state);
  state.duty_cycle = vibrator->direction_duty_cycle;
  state.enabled = true;

  err = pwm_apply_might_sleep(vibrator->pwm_dir, &state);
  if (err) {
   dev_err(pdev, "failed to apply dir-pwm state: %d\n", err);
   pwm_disable(vibrator->pwm);
   return err;
  }
 }

 return 0;
}

static void pwm_vibrator_stop(struct pwm_vibrator *vibrator)
{
 if (vibrator->pwm_dir)
  pwm_disable(vibrator->pwm_dir);
 pwm_disable(vibrator->pwm);

 gpiod_set_value_cansleep(vibrator->enable_gpio, 0);

 if (vibrator->vcc_on) {
  regulator_disable(vibrator->vcc);
  vibrator->vcc_on = false;
 }
}

static void pwm_vibrator_play_work(struct work_struct *work)
{
 struct pwm_vibrator *vibrator = container_of(work,
     struct pwm_vibrator, play_work);

 if (vibrator->level)
  pwm_vibrator_start(vibrator);
 else
  pwm_vibrator_stop(vibrator);
}

static int pwm_vibrator_play_effect(struct input_dev *dev, void *data,
        struct ff_effect *effect)
{
 struct pwm_vibrator *vibrator = input_get_drvdata(dev);

 vibrator->level = effect->u.rumble.strong_magnitude;
 if (!vibrator->level)
  vibrator->level = effect->u.rumble.weak_magnitude;

 schedule_work(&vibrator->play_work);

 return 0;
}

static void pwm_vibrator_close(struct input_dev *input)
{
 struct pwm_vibrator *vibrator = input_get_drvdata(input);

 cancel_work_sync(&vibrator->play_work);
 pwm_vibrator_stop(vibrator);
}

static int pwm_vibrator_probe(struct platform_device *pdev)
{
 struct pwm_vibrator *vibrator;
 struct pwm_state state;
 int err;

 vibrator = devm_kzalloc(&pdev->dev, sizeof(*vibrator), GFP_KERNEL);
 if (!vibrator)
  return -ENOMEM;

 vibrator->input = devm_input_allocate_device(&pdev->dev);
 if (!vibrator->input)
  return -ENOMEM;

 vibrator->vcc = devm_regulator_get(&pdev->dev, "vcc");
 if (IS_ERR(vibrator->vcc))
  return dev_err_probe(&pdev->dev, PTR_ERR(vibrator->vcc),
         "Failed to request regulator\n");

 vibrator->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
       GPIOD_OUT_LOW);
 if (IS_ERR(vibrator->enable_gpio))
  return dev_err_probe(&pdev->dev, PTR_ERR(vibrator->enable_gpio),
         "Failed to request enable gpio\n");

 vibrator->pwm = devm_pwm_get(&pdev->dev, "enable");
 if (IS_ERR(vibrator->pwm))
  return dev_err_probe(&pdev->dev, PTR_ERR(vibrator->pwm),
         "Failed to request main pwm\n");

 INIT_WORK(&vibrator->play_work, pwm_vibrator_play_work);

 /* Sync up PWM state and ensure it is off. */
 pwm_init_state(vibrator->pwm, &state);
 state.enabled = false;
 err = pwm_apply_might_sleep(vibrator->pwm, &state);
 if (err) {
  dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n",
   err);
  return err;
 }

 vibrator->pwm_dir = devm_pwm_get(&pdev->dev, "direction");
 err = PTR_ERR_OR_ZERO(vibrator->pwm_dir);
 switch (err) {
 case 0:
  /* Sync up PWM state and ensure it is off. */
  pwm_init_state(vibrator->pwm_dir, &state);
  state.enabled = false;
  err = pwm_apply_might_sleep(vibrator->pwm_dir, &state);
  if (err) {
   dev_err(&pdev->dev, "failed to apply initial PWM state: %d\n",
    err);
   return err;
  }

  vibrator->direction_duty_cycle =
   pwm_get_period(vibrator->pwm_dir) / 2;
  device_property_read_u32(&pdev->dev, "direction-duty-cycle-ns",
      &vibrator->direction_duty_cycle);
  break;

 case -ENODATA:
  /* Direction PWM is optional */
  vibrator->pwm_dir = NULL;
  break;

 default:
  dev_err(&pdev->dev, "Failed to request direction pwm: %d\n", err);
  fallthrough;

 case -EPROBE_DEFER:
  return err;
 }

 vibrator->input->name = "pwm-vibrator";
 vibrator->input->id.bustype = BUS_HOST;
 vibrator->input->dev.parent = &pdev->dev;
 vibrator->input->close = pwm_vibrator_close;

 input_set_drvdata(vibrator->input, vibrator);
 input_set_capability(vibrator->input, EV_FF, FF_RUMBLE);

 err = input_ff_create_memless(vibrator->input, NULL,
          pwm_vibrator_play_effect);
 if (err) {
  dev_err(&pdev->dev, "Couldn't create FF dev: %d\n", err);
  return err;
 }

 err = input_register_device(vibrator->input);
 if (err) {
  dev_err(&pdev->dev, "Couldn't register input dev: %d\n", err);
  return err;
 }

 platform_set_drvdata(pdev, vibrator);

 return 0;
}

static int pwm_vibrator_suspend(struct device *dev)
{
 struct pwm_vibrator *vibrator = dev_get_drvdata(dev);

 cancel_work_sync(&vibrator->play_work);
 if (vibrator->level)
  pwm_vibrator_stop(vibrator);

 return 0;
}

static int pwm_vibrator_resume(struct device *dev)
{
 struct pwm_vibrator *vibrator = dev_get_drvdata(dev);

 if (vibrator->level)
  pwm_vibrator_start(vibrator);

 return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(pwm_vibrator_pm_ops,
    pwm_vibrator_suspend, pwm_vibrator_resume);

#ifdef CONFIG_OF
static const struct of_device_id pwm_vibra_dt_match_table[] = {
 { .compatible = "pwm-vibrator" },
 {},
};
MODULE_DEVICE_TABLE(of, pwm_vibra_dt_match_table);
#endif

static struct platform_driver pwm_vibrator_driver = {
 .probe = pwm_vibrator_probe,
 .driver = {
  .name = "pwm-vibrator",
  .pm = pm_sleep_ptr(&pwm_vibrator_pm_ops),
  .of_match_table = of_match_ptr(pwm_vibra_dt_match_table),
 },
};
module_platform_driver(pwm_vibrator_driver);

MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");
MODULE_DESCRIPTION("PWM vibrator driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pwm-vibrator");