// SPDX-License-Identifier: GPL-2.0-only

  /*
   * LEDs driver for GPIOs
   *
   * Copyright (C) 2007 8D Technologies inc.
   * Raphael Assenat <raph@8d.com>

   * Copyright (C) 2008 Freescale Semiconductor, Inc.

   */

  #include <linux/err.h>

  #include <linux/gpio.h>

  #include <linux/gpio/consumer.h>

  #include <linux/kernel.h>

  #include <linux/leds.h>

  #include <linux/module.h>

  #include <linux/of.h>

  #include <linux/platform_device.h>

  #include <linux/property.h>

  #include <linux/slab.h>

  struct gpio_led_data {
  	struct led_classdev cdev;

  	struct gpio_desc *gpiod;

  	u8 can_sleep;

  	u8 blinking;

  	gpio_blink_set_t platform_gpio_blink_set;

  };

  static inline struct gpio_led_data *
  			cdev_to_gpio_led_data(struct led_classdev *led_cdev)
  {
  	return container_of(led_cdev, struct gpio_led_data, cdev);
  }

  static void gpio_led_set(struct led_classdev *led_cdev,
  	enum led_brightness value)
  {

  	struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);

  	int level;
  
  	if (value == LED_OFF)
  		level = 0;
  	else
  		level = 1;

  	if (led_dat->blinking) {
  		led_dat->platform_gpio_blink_set(led_dat->gpiod, level,
  						 NULL, NULL);
  		led_dat->blinking = 0;

  	} else {

  		if (led_dat->can_sleep)
  			gpiod_set_value_cansleep(led_dat->gpiod, level);
  		else

  			gpiod_set_value(led_dat->gpiod, level);

  	}

  }

  static int gpio_led_set_blocking(struct led_classdev *led_cdev,
  	enum led_brightness value)
  {
  	gpio_led_set(led_cdev, value);
  	return 0;
  }

  static int gpio_blink_set(struct led_classdev *led_cdev,
  	unsigned long *delay_on, unsigned long *delay_off)
  {

  	struct gpio_led_data *led_dat = cdev_to_gpio_led_data(led_cdev);

  	led_dat->blinking = 1;

  	return led_dat->platform_gpio_blink_set(led_dat->gpiod, GPIO_LED_BLINK,

  						delay_on, delay_off);

  }

  static int create_gpio_led(const struct gpio_led *template,

  	struct gpio_led_data *led_dat, struct device *parent,

  	struct fwnode_handle *fwnode, gpio_blink_set_t blink_set)

  {

  	struct led_init_data init_data = {};

  	int ret, state;

  	led_dat->cdev.default_trigger = template->default_trigger;

  	led_dat->can_sleep = gpiod_cansleep(led_dat->gpiod);

  	if (!led_dat->can_sleep)
  		led_dat->cdev.brightness_set = gpio_led_set;
  	else
  		led_dat->cdev.brightness_set_blocking = gpio_led_set_blocking;

  	led_dat->blinking = 0;

  	if (blink_set) {
  		led_dat->platform_gpio_blink_set = blink_set;
  		led_dat->cdev.blink_set = gpio_blink_set;
  	}

  	if (template->default_state == LEDS_GPIO_DEFSTATE_KEEP) {
  		state = gpiod_get_value_cansleep(led_dat->gpiod);
  		if (state < 0)
  			return state;
  	} else {

  		state = (template->default_state == LEDS_GPIO_DEFSTATE_ON);

  	}

  	led_dat->cdev.brightness = state ? LED_FULL : LED_OFF;

  	if (!template->retain_state_suspended)
  		led_dat->cdev.flags |= LED_CORE_SUSPENDRESUME;

  	if (template->panic_indicator)
  		led_dat->cdev.flags |= LED_PANIC_INDICATOR;

  	if (template->retain_state_shutdown)
  		led_dat->cdev.flags |= LED_RETAIN_AT_SHUTDOWN;

  	ret = gpiod_direction_output(led_dat->gpiod, state);

  	if (ret < 0)

  		return ret;

  	if (template->name) {
  		led_dat->cdev.name = template->name;
  		ret = devm_led_classdev_register(parent, &led_dat->cdev);
  	} else {
  		init_data.fwnode = fwnode;
  		ret = devm_led_classdev_register_ext(parent, &led_dat->cdev,
  						     &init_data);
  	}
  
  	return ret;

  }

  struct gpio_leds_priv {
  	int num_leds;
  	struct gpio_led_data leds[];
  };

  static struct gpio_leds_priv *gpio_leds_create(struct platform_device *pdev)

  {

  	struct device *dev = &pdev->dev;
  	struct fwnode_handle *child;

  	struct gpio_leds_priv *priv;

  	int count, ret;

  	count = device_get_child_node_count(dev);

  	if (!count)

  		return ERR_PTR(-ENODEV);

  	priv = devm_kzalloc(dev, struct_size(priv, leds, count), GFP_KERNEL);

  	if (!priv)

  		return ERR_PTR(-ENOMEM);

  	device_for_each_child_node(dev, child) {

  		struct gpio_led_data *led_dat = &priv->leds[priv->num_leds];

  		struct gpio_led led = {};

  		const char *state = NULL;

  		/*
  		 * Acquire gpiod from DT with uninitialized label, which
  		 * will be updated after LED class device is registered,
  		 * Only then the final LED name is known.
  		 */

  		led.gpiod = devm_fwnode_get_gpiod_from_child(dev, NULL, child,
  							     GPIOD_ASIS,

  							     NULL);

  		if (IS_ERR(led.gpiod)) {
  			fwnode_handle_put(child);
  			return ERR_CAST(led.gpiod);
  		}

  		led_dat->gpiod = led.gpiod;

  		if (!fwnode_property_read_string(child, "default-state",

  						 &state)) {

  			if (!strcmp(state, "keep"))
  				led.default_state = LEDS_GPIO_DEFSTATE_KEEP;

  			else if (!strcmp(state, "on"))

  				led.default_state = LEDS_GPIO_DEFSTATE_ON;
  			else
  				led.default_state = LEDS_GPIO_DEFSTATE_OFF;
  		}

  		if (fwnode_property_present(child, "retain-state-suspended"))

  			led.retain_state_suspended = 1;

  		if (fwnode_property_present(child, "retain-state-shutdown"))
  			led.retain_state_shutdown = 1;

  		if (fwnode_property_present(child, "panic-indicator"))
  			led.panic_indicator = 1;

  		ret = create_gpio_led(&led, led_dat, dev, child, NULL);

  		if (ret < 0) {

  			fwnode_handle_put(child);

  			return ERR_PTR(ret);

  		}

  		/* Set gpiod label to match the corresponding LED name. */
  		gpiod_set_consumer_name(led_dat->gpiod,
  					led_dat->cdev.dev->kobj.name);

  		priv->num_leds++;

  	}

  	return priv;

  }

  static const struct of_device_id of_gpio_leds_match[] = {
  	{ .compatible = "gpio-leds", },
  	{},
  };

  
  MODULE_DEVICE_TABLE(of, of_gpio_leds_match);

  static struct gpio_desc *gpio_led_get_gpiod(struct device *dev, int idx,
  					    const struct gpio_led *template)
  {
  	struct gpio_desc *gpiod;
  	unsigned long flags = GPIOF_OUT_INIT_LOW;
  	int ret;
  
  	/*
  	 * This means the LED does not come from the device tree
  	 * or ACPI, so let's try just getting it by index from the
  	 * device, this will hit the board file, if any and get
  	 * the GPIO from there.
  	 */

  	gpiod = devm_gpiod_get_index(dev, NULL, idx, GPIOD_OUT_LOW);

  	if (!IS_ERR(gpiod)) {
  		gpiod_set_consumer_name(gpiod, template->name);
  		return gpiod;
  	}
  	if (PTR_ERR(gpiod) != -ENOENT)
  		return gpiod;
  
  	/*
  	 * This is the legacy code path for platform code that
  	 * still uses GPIO numbers. Ultimately we would like to get
  	 * rid of this block completely.
  	 */
  
  	/* skip leds that aren't available */
  	if (!gpio_is_valid(template->gpio))
  		return ERR_PTR(-ENOENT);
  
  	if (template->active_low)
  		flags |= GPIOF_ACTIVE_LOW;
  
  	ret = devm_gpio_request_one(dev, template->gpio, flags,
  				    template->name);
  	if (ret < 0)
  		return ERR_PTR(ret);
  
  	gpiod = gpio_to_desc(template->gpio);
  	if (!gpiod)
  		return ERR_PTR(-EINVAL);
  
  	return gpiod;
  }

  static int gpio_led_probe(struct platform_device *pdev)

  {

  	struct gpio_led_platform_data *pdata = dev_get_platdata(&pdev->dev);

  	struct gpio_leds_priv *priv;
  	int i, ret = 0;
  
  	if (pdata && pdata->num_leds) {

  		priv = devm_kzalloc(&pdev->dev, struct_size(priv, leds, pdata->num_leds),
  				    GFP_KERNEL);

  		if (!priv)
  			return -ENOMEM;
  
  		priv->num_leds = pdata->num_leds;
  		for (i = 0; i < priv->num_leds; i++) {

  			const struct gpio_led *template = &pdata->leds[i];
  			struct gpio_led_data *led_dat = &priv->leds[i];
  
  			if (template->gpiod)
  				led_dat->gpiod = template->gpiod;
  			else
  				led_dat->gpiod =
  					gpio_led_get_gpiod(&pdev->dev,
  							   i, template);
  			if (IS_ERR(led_dat->gpiod)) {
  				dev_info(&pdev->dev, "Skipping unavailable LED gpio %d (%s)
  ",
  					 template->gpio, template->name);
  				continue;
  			}
  
  			ret = create_gpio_led(template, led_dat,

  					      &pdev->dev, NULL,
  					      pdata->gpio_blink_set);

  			if (ret < 0)

  				return ret;

  		}
  	} else {

  		priv = gpio_leds_create(pdev);

  		if (IS_ERR(priv))
  			return PTR_ERR(priv);

  	}
  
  	platform_set_drvdata(pdev, priv);
  
  	return 0;

  }

  static void gpio_led_shutdown(struct platform_device *pdev)
  {
  	struct gpio_leds_priv *priv = platform_get_drvdata(pdev);
  	int i;
  
  	for (i = 0; i < priv->num_leds; i++) {
  		struct gpio_led_data *led = &priv->leds[i];

  		if (!(led->cdev.flags & LED_RETAIN_AT_SHUTDOWN))
  			gpio_led_set(&led->cdev, LED_OFF);

  	}
  }

  static struct platform_driver gpio_led_driver = {
  	.probe		= gpio_led_probe,

  	.shutdown	= gpio_led_shutdown,

  	.driver		= {
  		.name	= "leds-gpio",

  		.of_match_table = of_gpio_leds_match,

  	},

  };

  module_platform_driver(gpio_led_driver);

  
  MODULE_AUTHOR("Raphael Assenat <raph@8d.com>, Trent Piepho <tpiepho@freescale.com>");

  MODULE_DESCRIPTION("GPIO LED driver");
  MODULE_LICENSE("GPL");

  MODULE_ALIAS("platform:leds-gpio");