drivers/leds/leds-gpio.c - linux - Git at Google

 // 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 inline int sizeof_gpio_leds_priv(int num_leds)
 {
 	return sizeof(struct gpio_leds_priv) +
 		(sizeof(struct gpio_led_data) * num_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, sizeof_gpio_leds_priv(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;

 		fwnode_property_read_string(child, "linux,default-trigger",
 					    &led.default_trigger);

 		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, flags);
 	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,
 				sizeof_gpio_leds_priv(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)\n",
 					 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");
	// 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 inline int sizeof_gpio_leds_priv(int num_leds)
	{
	return sizeof(struct gpio_leds_priv) +
	(sizeof(struct gpio_led_data) * num_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, sizeof_gpio_leds_priv(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;

	fwnode_property_read_string(child, "linux,default-trigger",
	&led.default_trigger);

	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, flags);
	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,
	sizeof_gpio_leds_priv(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)\n",
	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");