Quelle  leds-sgm3140.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2020 Luca Weiss <luca@z3ntu.xyz>

#include <linux/gpio/consumer.h>
#include <linux/led-class-flash.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/platform_device.h>

#include <media/v4l2-flash-led-class.h>

#define FLASH_TIMEOUT_DEFAULT  250000U /* 250ms */
#define FLASH_MAX_TIMEOUT_DEFAULT 300000U /* 300ms */

struct sgm3140 {
 struct led_classdev_flash fled_cdev;
 struct v4l2_flash *v4l2_flash;

 struct timer_list powerdown_timer;

 struct gpio_desc *flash_gpio;
 struct gpio_desc *enable_gpio;
 struct regulator *vin_regulator;

 bool enabled;

 /* current timeout in us */
 u32 timeout;
 /* maximum timeout in us */
 u32 max_timeout;
};

static struct sgm3140 *flcdev_to_sgm3140(struct led_classdev_flash *flcdev)
{
 return container_of(flcdev, struct sgm3140, fled_cdev);
}

static int sgm3140_strobe_set(struct led_classdev_flash *fled_cdev, bool state)
{
 struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
 int ret;

 if (priv->enabled == state)
  return 0;

 if (state) {
  ret = regulator_enable(priv->vin_regulator);
  if (ret) {
   dev_err(fled_cdev->led_cdev.dev,
    "failed to enable regulator: %d\n", ret);
   return ret;
  }
  gpiod_set_value_cansleep(priv->flash_gpio, 1);
  gpiod_set_value_cansleep(priv->enable_gpio, 1);
  mod_timer(&priv->powerdown_timer,
     jiffies + usecs_to_jiffies(priv->timeout));
 } else {
  timer_delete_sync(&priv->powerdown_timer);
  gpiod_set_value_cansleep(priv->enable_gpio, 0);
  gpiod_set_value_cansleep(priv->flash_gpio, 0);
  ret = regulator_disable(priv->vin_regulator);
  if (ret) {
   dev_err(fled_cdev->led_cdev.dev,
    "failed to disable regulator: %d\n", ret);
   return ret;
  }
 }

 priv->enabled = state;

 return 0;
}

static int sgm3140_strobe_get(struct led_classdev_flash *fled_cdev, bool *state)
{
 struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);

 *state = timer_pending(&priv->powerdown_timer);

 return 0;
}

static int sgm3140_timeout_set(struct led_classdev_flash *fled_cdev,
          u32 timeout)
{
 struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);

 priv->timeout = timeout;

 return 0;
}

static const struct led_flash_ops sgm3140_flash_ops = {
 .strobe_set = sgm3140_strobe_set,
 .strobe_get = sgm3140_strobe_get,
 .timeout_set = sgm3140_timeout_set,
};

static int sgm3140_brightness_set(struct led_classdev *led_cdev,
      enum led_brightness brightness)
{
 struct led_classdev_flash *fled_cdev = lcdev_to_flcdev(led_cdev);
 struct sgm3140 *priv = flcdev_to_sgm3140(fled_cdev);
 bool enable = brightness == LED_ON;
 int ret;

 if (priv->enabled == enable)
  return 0;

 if (enable) {
  ret = regulator_enable(priv->vin_regulator);
  if (ret) {
   dev_err(led_cdev->dev,
    "failed to enable regulator: %d\n", ret);
   return ret;
  }
  gpiod_set_value_cansleep(priv->flash_gpio, 0);
  gpiod_set_value_cansleep(priv->enable_gpio, 1);
 } else {
  timer_delete_sync(&priv->powerdown_timer);
  gpiod_set_value_cansleep(priv->flash_gpio, 0);
  gpiod_set_value_cansleep(priv->enable_gpio, 0);
  ret = regulator_disable(priv->vin_regulator);
  if (ret) {
   dev_err(led_cdev->dev,
    "failed to disable regulator: %d\n", ret);
   return ret;
  }
 }

 priv->enabled = enable;

 return 0;
}

static void sgm3140_powerdown_timer(struct timer_list *t)
{
 struct sgm3140 *priv = timer_container_of(priv, t, powerdown_timer);

 gpiod_set_value(priv->enable_gpio, 0);
 gpiod_set_value(priv->flash_gpio, 0);
 regulator_disable(priv->vin_regulator);

 priv->enabled = false;
}

static void sgm3140_init_flash_timeout(struct sgm3140 *priv)
{
 struct led_classdev_flash *fled_cdev = &priv->fled_cdev;
 struct led_flash_setting *s;

 /* Init flash timeout setting */
 s = &fled_cdev->timeout;
 s->min = 1;
 s->max = priv->max_timeout;
 s->step = 1;
 s->val = FLASH_TIMEOUT_DEFAULT;
}

#if IS_ENABLED(CONFIG_V4L2_FLASH_LED_CLASS)
static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
     struct v4l2_flash_config *v4l2_sd_cfg)
{
 struct led_classdev *led_cdev = &priv->fled_cdev.led_cdev;
 struct led_flash_setting *s;

 strscpy(v4l2_sd_cfg->dev_name, led_cdev->dev->kobj.name,
  sizeof(v4l2_sd_cfg->dev_name));

 /* Init flash intensity setting */
 s = &v4l2_sd_cfg->intensity;
 s->min = 0;
 s->max = 1;
 s->step = 1;
 s->val = 1;
}

#else
static void sgm3140_init_v4l2_flash_config(struct sgm3140 *priv,
     struct v4l2_flash_config *v4l2_sd_cfg)
{
}
#endif

static int sgm3140_probe(struct platform_device *pdev)
{
 struct sgm3140 *priv;
 struct led_classdev *led_cdev;
 struct led_classdev_flash *fled_cdev;
 struct led_init_data init_data = {};
 struct fwnode_handle *child_node;
 struct v4l2_flash_config v4l2_sd_cfg = {};
 int ret;

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

 priv->flash_gpio = devm_gpiod_get(&pdev->dev, "flash", GPIOD_OUT_LOW);
 ret = PTR_ERR_OR_ZERO(priv->flash_gpio);
 if (ret)
  return dev_err_probe(&pdev->dev, ret,
         "Failed to request flash gpio\n");

 priv->enable_gpio = devm_gpiod_get(&pdev->dev, "enable", GPIOD_OUT_LOW);
 ret = PTR_ERR_OR_ZERO(priv->enable_gpio);
 if (ret)
  return dev_err_probe(&pdev->dev, ret,
         "Failed to request enable gpio\n");

 priv->vin_regulator = devm_regulator_get(&pdev->dev, "vin");
 ret = PTR_ERR_OR_ZERO(priv->vin_regulator);
 if (ret)
  return dev_err_probe(&pdev->dev, ret,
         "Failed to request regulator\n");

 child_node = fwnode_get_next_available_child_node(pdev->dev.fwnode,
         NULL);
 if (!child_node) {
  dev_err(&pdev->dev,
   "No fwnode child node found for connected LED.\n");
  return -EINVAL;
 }

 ret = fwnode_property_read_u32(child_node, "flash-max-timeout-us",
           &priv->max_timeout);
 if (ret) {
  priv->max_timeout = FLASH_MAX_TIMEOUT_DEFAULT;
  dev_warn(&pdev->dev,
    "flash-max-timeout-us property missing\n");
 }

 /*
 * Set default timeout to FLASH_DEFAULT_TIMEOUT except if max_timeout
 * from DT is lower.
 */
 priv->timeout = min(priv->max_timeout, FLASH_TIMEOUT_DEFAULT);

 timer_setup(&priv->powerdown_timer, sgm3140_powerdown_timer, 0);

 fled_cdev = &priv->fled_cdev;
 led_cdev = &fled_cdev->led_cdev;

 fled_cdev->ops = &sgm3140_flash_ops;

 led_cdev->brightness_set_blocking = sgm3140_brightness_set;
 led_cdev->max_brightness = LED_ON;
 led_cdev->flags |= LED_DEV_CAP_FLASH;

 sgm3140_init_flash_timeout(priv);

 init_data.fwnode = child_node;

 platform_set_drvdata(pdev, priv);

 /* Register in the LED subsystem */
 ret = devm_led_classdev_flash_register_ext(&pdev->dev,
         fled_cdev, &init_data);
 if (ret) {
  dev_err(&pdev->dev, "Failed to register flash device: %d\n",
   ret);
  goto err;
 }

 sgm3140_init_v4l2_flash_config(priv, &v4l2_sd_cfg);

 /* Create V4L2 Flash subdev */
 priv->v4l2_flash = v4l2_flash_init(&pdev->dev,
        child_node,
        fled_cdev, NULL,
        &v4l2_sd_cfg);
 if (IS_ERR(priv->v4l2_flash)) {
  ret = PTR_ERR(priv->v4l2_flash);
  goto err;
 }

 return ret;

err:
 fwnode_handle_put(child_node);
 return ret;
}

static void sgm3140_remove(struct platform_device *pdev)
{
 struct sgm3140 *priv = platform_get_drvdata(pdev);

 timer_delete_sync(&priv->powerdown_timer);

 v4l2_flash_release(priv->v4l2_flash);
}

static const struct of_device_id sgm3140_dt_match[] = {
 { .compatible = "ocs,ocp8110" },
 { .compatible = "richtek,rt5033-led" },
 { .compatible = "sgmicro,sgm3140" },
 { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, sgm3140_dt_match);

static struct platform_driver sgm3140_driver = {
 .probe = sgm3140_probe,
 .remove = sgm3140_remove,
 .driver = {
  .name = "sgm3140",
  .of_match_table = sgm3140_dt_match,
 },
};

module_platform_driver(sgm3140_driver);

MODULE_AUTHOR("Luca Weiss ");
MODULE_DESCRIPTION("SG Micro SGM3140 charge pump LED driver");
MODULE_LICENSE("GPL v2");