Quelle  regulator-haptic.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Regulator haptic driver
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
 * Author: Jaewon Kim <jaewon02.kim@samsung.com>
 * Author: Hyunhee Kim <hyunhee.kim@samsung.com>
 */

#include <linux/input.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_data/regulator-haptic.h>
#include <linux/platform_device.h>
#include <linux/regulator/consumer.h>
#include <linux/slab.h>
#include <linux/string_choices.h>

#define MAX_MAGNITUDE_SHIFT 16

struct regulator_haptic {
 struct device *dev;
 struct input_dev *input_dev;
 struct regulator *regulator;

 struct work_struct work;
 struct mutex mutex;

 bool active;
 bool suspended;

 unsigned int max_volt;
 unsigned int min_volt;
 unsigned int magnitude;
};

static int regulator_haptic_toggle(struct regulator_haptic *haptic, bool on)
{
 int error;

 if (haptic->active != on) {

  error = on ? regulator_enable(haptic->regulator) :
        regulator_disable(haptic->regulator);
  if (error) {
   dev_err(haptic->dev,
    "failed to switch regulator %s: %d\n",
    str_on_off(on), error);
   return error;
  }

  haptic->active = on;
 }

 return 0;
}

static int regulator_haptic_set_voltage(struct regulator_haptic *haptic,
      unsigned int magnitude)
{
 u64 volt_mag_multi;
 unsigned int intensity;
 int error;

 volt_mag_multi = (u64)(haptic->max_volt - haptic->min_volt) * magnitude;
 intensity = (unsigned int)(volt_mag_multi >> MAX_MAGNITUDE_SHIFT);

 error = regulator_set_voltage(haptic->regulator,
          intensity + haptic->min_volt,
          haptic->max_volt);
 if (error) {
  dev_err(haptic->dev, "cannot set regulator voltage to %d: %d\n",
   intensity + haptic->min_volt, error);
  return error;
 }

 regulator_haptic_toggle(haptic, !!magnitude);

 return 0;
}

static void regulator_haptic_work(struct work_struct *work)
{
 struct regulator_haptic *haptic = container_of(work,
     struct regulator_haptic, work);

 guard(mutex)(&haptic->mutex);

 if (!haptic->suspended)
  regulator_haptic_set_voltage(haptic, haptic->magnitude);
}

static int regulator_haptic_play_effect(struct input_dev *input, void *data,
     struct ff_effect *effect)
{
 struct regulator_haptic *haptic = input_get_drvdata(input);

 haptic->magnitude = effect->u.rumble.strong_magnitude;
 if (!haptic->magnitude)
  haptic->magnitude = effect->u.rumble.weak_magnitude;

 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_set_voltage(haptic, 0);
}

static int __maybe_unused
regulator_haptic_parse_dt(struct device *dev, struct regulator_haptic *haptic)
{
 struct device_node *node;
 int error;

 node = dev->of_node;
 if(!node) {
  dev_err(dev, "Missing device tree data\n");
  return -EINVAL;
 }

 error = of_property_read_u32(node, "max-microvolt", &haptic->max_volt);
 if (error) {
  dev_err(dev, "cannot parse max-microvolt\n");
  return error;
 }

 error = of_property_read_u32(node, "min-microvolt", &haptic->min_volt);
 if (error) {
  dev_err(dev, "cannot parse min-microvolt\n");
  return error;
 }

 return 0;
}

static int regulator_haptic_probe(struct platform_device *pdev)
{
 const struct regulator_haptic_data *pdata = dev_get_platdata(&pdev->dev);
 struct regulator_haptic *haptic;
 struct input_dev *input_dev;
 int error;

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

 platform_set_drvdata(pdev, haptic);
 haptic->dev = &pdev->dev;
 mutex_init(&haptic->mutex);
 INIT_WORK(&haptic->work, regulator_haptic_work);

 if (pdata) {
  haptic->max_volt = pdata->max_volt;
  haptic->min_volt = pdata->min_volt;
 } else if (IS_ENABLED(CONFIG_OF)) {
  error = regulator_haptic_parse_dt(&pdev->dev, haptic);
  if (error)
   return error;
 } else {
  dev_err(&pdev->dev, "Missing platform data\n");
  return -EINVAL;
 }

 haptic->regulator = devm_regulator_get_exclusive(&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;
 }

 return 0;
}

static int regulator_haptic_suspend(struct device *dev)
{
 struct platform_device *pdev = to_platform_device(dev);
 struct regulator_haptic *haptic = platform_get_drvdata(pdev);

 scoped_guard(mutex_intr, &haptic->mutex) {
  regulator_haptic_set_voltage(haptic, 0);
  haptic->suspended = true;

  return 0;
 }

 return -EINTR;
}

static int regulator_haptic_resume(struct device *dev)
{
 struct platform_device *pdev = to_platform_device(dev);
 struct regulator_haptic *haptic = platform_get_drvdata(pdev);
 unsigned int magnitude;

 guard(mutex)(&haptic->mutex);

 haptic->suspended = false;

 magnitude = READ_ONCE(haptic->magnitude);
 if (magnitude)
  regulator_haptic_set_voltage(haptic, magnitude);

 return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(regulator_haptic_pm_ops,
  regulator_haptic_suspend, regulator_haptic_resume);

static const struct of_device_id regulator_haptic_dt_match[] = {
 { .compatible = "regulator-haptic" },
 { /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, regulator_haptic_dt_match);

static struct platform_driver regulator_haptic_driver = {
 .probe  = regulator_haptic_probe,
 .driver  = {
  .name  = "regulator-haptic",
  .of_match_table = regulator_haptic_dt_match,
  .pm  = pm_sleep_ptr(®ulator_haptic_pm_ops),
 },
};
module_platform_driver(regulator_haptic_driver);

MODULE_AUTHOR("Jaewon Kim ");
MODULE_AUTHOR("Hyunhee Kim ");
MODULE_DESCRIPTION("Regulator haptic driver");
MODULE_LICENSE("GPL");