drivers/leds/leds-gpio.c

Source file repositories/reference/linux-study-clean/drivers/leds/leds-gpio.c

File Facts

System
Linux kernel
Corpus path
drivers/leds/leds-gpio.c
Extension
.c
Size
8458 bytes
Lines
328
Domain
Driver Families
Bucket
drivers/leds
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

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 = {};
	struct pinctrl *pinctrl;
	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_dat->cdev.max_brightness = 1;
	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);

Annotation

Implementation Notes