[linux-2.6-block.git] / drivers / leds / led-core.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * LED Class Core
 *
 * Copyright 2005-2006 Openedhand Ltd.
 *
 * Author: Richard Purdie <rpurdie@openedhand.com>
 */

#include <linux/kernel.h>
#include <linux/led-class-multicolor.h>
#include <linux/leds.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/property.h>
#include <linux/rwsem.h>
#include <linux/slab.h>
#include <uapi/linux/uleds.h>
#include "leds.h"

DECLARE_RWSEM(leds_list_lock);
EXPORT_SYMBOL_GPL(leds_list_lock);

LIST_HEAD(leds_list);
EXPORT_SYMBOL_GPL(leds_list);

static const char * const led_colors[LED_COLOR_ID_MAX] = {
	[LED_COLOR_ID_WHITE] = "white",
	[LED_COLOR_ID_RED] = "red",
	[LED_COLOR_ID_GREEN] = "green",
	[LED_COLOR_ID_BLUE] = "blue",
	[LED_COLOR_ID_AMBER] = "amber",
	[LED_COLOR_ID_VIOLET] = "violet",
	[LED_COLOR_ID_YELLOW] = "yellow",
	[LED_COLOR_ID_IR] = "ir",
	[LED_COLOR_ID_MULTI] = "multicolor",
	[LED_COLOR_ID_RGB] = "rgb",
	[LED_COLOR_ID_PURPLE] = "purple",
	[LED_COLOR_ID_ORANGE] = "orange",
	[LED_COLOR_ID_PINK] = "pink",
	[LED_COLOR_ID_CYAN] = "cyan",
	[LED_COLOR_ID_LIME] = "lime",
};

static int __led_set_brightness(struct led_classdev *led_cdev, unsigned int value)
{
	if (!led_cdev->brightness_set)
		return -ENOTSUPP;

	led_cdev->brightness_set(led_cdev, value);

	return 0;
}

static int __led_set_brightness_blocking(struct led_classdev *led_cdev, unsigned int value)
{
	if (!led_cdev->brightness_set_blocking)
		return -ENOTSUPP;

	return led_cdev->brightness_set_blocking(led_cdev, value);
}

static void led_timer_function(struct timer_list *t)
{
	struct led_classdev *led_cdev = timer_container_of(led_cdev, t,
							   blink_timer);
	unsigned long brightness;
	unsigned long delay;

	if (!led_cdev->blink_delay_on || !led_cdev->blink_delay_off) {
		led_set_brightness_nosleep(led_cdev, LED_OFF);
		clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
		return;
	}

	if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
			       &led_cdev->work_flags)) {
		clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
		return;
	}

	brightness = led_get_brightness(led_cdev);
	if (!brightness) {
		/* Time to switch the LED on. */
		if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
					&led_cdev->work_flags))
			brightness = led_cdev->new_blink_brightness;
		else
			brightness = led_cdev->blink_brightness;
		delay = led_cdev->blink_delay_on;
	} else {
		/* Store the current brightness value to be able
		 * to restore it when the delay_off period is over.
		 */
		led_cdev->blink_brightness = brightness;
		brightness = LED_OFF;
		delay = led_cdev->blink_delay_off;
	}

	led_set_brightness_nosleep(led_cdev, brightness);

	/* Return in next iteration if led is in one-shot mode and we are in
	 * the final blink state so that the led is toggled each delay_on +
	 * delay_off milliseconds in worst case.
	 */
	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
		if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
			if (brightness)
				set_bit(LED_BLINK_ONESHOT_STOP,
					&led_cdev->work_flags);
		} else {
			if (!brightness)
				set_bit(LED_BLINK_ONESHOT_STOP,
					&led_cdev->work_flags);
		}
	}

	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
}

static void set_brightness_delayed_set_brightness(struct led_classdev *led_cdev,
						  unsigned int value)
{
	int ret;

	ret = __led_set_brightness(led_cdev, value);
	if (ret == -ENOTSUPP) {
		ret = __led_set_brightness_blocking(led_cdev, value);
		if (ret == -ENOTSUPP)
			/* No back-end support to set a fixed brightness value */
			return;
	}

	/* LED HW might have been unplugged, therefore don't warn */
	if (ret == -ENODEV && led_cdev->flags & LED_UNREGISTERING &&
	    led_cdev->flags & LED_HW_PLUGGABLE)
		return;

	if (ret < 0)
		dev_err(led_cdev->dev,
			"Setting an LED's brightness failed (%d)\n", ret);
}

static void set_brightness_delayed(struct work_struct *ws)
{
	struct led_classdev *led_cdev =
		container_of(ws, struct led_classdev, set_brightness_work);

	if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
		led_stop_software_blink(led_cdev);
		set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags);
	}

	/*
	 * Triggers may call led_set_brightness(LED_OFF),
	 * led_set_brightness(LED_FULL) in quick succession to disable blinking
	 * and turn the LED on. Both actions may have been scheduled to run
	 * before this work item runs once. To make sure this works properly
	 * handle LED_SET_BRIGHTNESS_OFF first.
	 */
	if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) {
		set_brightness_delayed_set_brightness(led_cdev, LED_OFF);
		/*
		 * The consecutives led_set_brightness(LED_OFF),
		 * led_set_brightness(LED_FULL) could have been executed out of
		 * order (LED_FULL first), if the work_flags has been set
		 * between LED_SET_BRIGHTNESS_OFF and LED_SET_BRIGHTNESS of this
		 * work. To avoid ending with the LED turned off, turn the LED
		 * on again.
		 */
		if (led_cdev->delayed_set_value != LED_OFF)
			set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
	}

	if (test_and_clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags))
		set_brightness_delayed_set_brightness(led_cdev, led_cdev->delayed_set_value);

	if (test_and_clear_bit(LED_SET_BLINK, &led_cdev->work_flags)) {
		unsigned long delay_on = led_cdev->delayed_delay_on;
		unsigned long delay_off = led_cdev->delayed_delay_off;

		led_blink_set(led_cdev, &delay_on, &delay_off);
	}
}

static void led_set_software_blink(struct led_classdev *led_cdev,
				   unsigned long delay_on,
				   unsigned long delay_off)
{
	int current_brightness;

	current_brightness = led_get_brightness(led_cdev);
	if (current_brightness)
		led_cdev->blink_brightness = current_brightness;
	if (!led_cdev->blink_brightness)
		led_cdev->blink_brightness = led_cdev->max_brightness;

	led_cdev->blink_delay_on = delay_on;
	led_cdev->blink_delay_off = delay_off;

	/* never on - just set to off */
	if (!delay_on) {
		led_set_brightness_nosleep(led_cdev, LED_OFF);
		return;
	}

	/* never off - just set to brightness */
	if (!delay_off) {
		led_set_brightness_nosleep(led_cdev,
					   led_cdev->blink_brightness);
		return;
	}

	set_bit(LED_BLINK_SW, &led_cdev->work_flags);
	mod_timer(&led_cdev->blink_timer, jiffies + 1);
}


static void led_blink_setup(struct led_classdev *led_cdev,
		     unsigned long *delay_on,
		     unsigned long *delay_off)
{
	if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	    led_cdev->blink_set &&
	    !led_cdev->blink_set(led_cdev, delay_on, delay_off))
		return;

	/* blink with 1 Hz as default if nothing specified */
	if (!*delay_on && !*delay_off)
		*delay_on = *delay_off = 500;

	led_set_software_blink(led_cdev, *delay_on, *delay_off);
}

void led_init_core(struct led_classdev *led_cdev)
{
	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);

	timer_setup(&led_cdev->blink_timer, led_timer_function, 0);
}
EXPORT_SYMBOL_GPL(led_init_core);

void led_blink_set(struct led_classdev *led_cdev,
		   unsigned long *delay_on,
		   unsigned long *delay_off)
{
	timer_delete_sync(&led_cdev->blink_timer);

	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);

	led_blink_setup(led_cdev, delay_on, delay_off);
}
EXPORT_SYMBOL_GPL(led_blink_set);

void led_blink_set_oneshot(struct led_classdev *led_cdev,
			   unsigned long *delay_on,
			   unsigned long *delay_off,
			   int invert)
{
	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	     timer_pending(&led_cdev->blink_timer))
		return;

	set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);

	if (invert)
		set_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
	else
		clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags);

	led_blink_setup(led_cdev, delay_on, delay_off);
}
EXPORT_SYMBOL_GPL(led_blink_set_oneshot);

void led_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on,
			   unsigned long delay_off)
{
	/* If necessary delegate to a work queue task. */
	if (led_cdev->blink_set && led_cdev->brightness_set_blocking) {
		led_cdev->delayed_delay_on = delay_on;
		led_cdev->delayed_delay_off = delay_off;
		set_bit(LED_SET_BLINK, &led_cdev->work_flags);
		queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
		return;
	}

	led_blink_set(led_cdev, &delay_on, &delay_off);
}
EXPORT_SYMBOL_GPL(led_blink_set_nosleep);

void led_stop_software_blink(struct led_classdev *led_cdev)
{
	timer_delete_sync(&led_cdev->blink_timer);
	led_cdev->blink_delay_on = 0;
	led_cdev->blink_delay_off = 0;
	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
}
EXPORT_SYMBOL_GPL(led_stop_software_blink);

void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness)
{
	/*
	 * If software blink is active, delay brightness setting
	 * until the next timer tick.
	 */
	if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
		/*
		 * If we need to disable soft blinking delegate this to the
		 * work queue task to avoid problems in case we are called
		 * from hard irq context.
		 */
		if (!brightness) {
			set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags);
			queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
		} else {
			set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
				&led_cdev->work_flags);
			led_cdev->new_blink_brightness = brightness;
		}
		return;
	}

	led_set_brightness_nosleep(led_cdev, brightness);
}
EXPORT_SYMBOL_GPL(led_set_brightness);

void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value)
{
	/* Use brightness_set op if available, it is guaranteed not to sleep */
	if (!__led_set_brightness(led_cdev, value))
		return;

	/*
	 * Brightness setting can sleep, delegate it to a work queue task.
	 * value 0 / LED_OFF is special, since it also disables hw-blinking
	 * (sw-blink disable is handled in led_set_brightness()).
	 * To avoid a hw-blink-disable getting lost when a second brightness
	 * change is done immediately afterwards (before the work runs),
	 * it uses a separate work_flag.
	 */
	led_cdev->delayed_set_value = value;
	/* Ensure delayed_set_value is seen before work_flags modification */
	smp_mb__before_atomic();

	if (value)
		set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
	else {
		clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
		clear_bit(LED_SET_BLINK, &led_cdev->work_flags);
		set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags);
	}

	queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
}
EXPORT_SYMBOL_GPL(led_set_brightness_nopm);

void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value)
{
	led_cdev->brightness = min(value, led_cdev->max_brightness);

	if (led_cdev->flags & LED_SUSPENDED)
		return;

	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
}
EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);

int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value)
{
	if (led_cdev->blink_delay_on || led_cdev->blink_delay_off)
		return -EBUSY;

	led_cdev->brightness = min(value, led_cdev->max_brightness);

	if (led_cdev->flags & LED_SUSPENDED)
		return 0;

	return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
}
EXPORT_SYMBOL_GPL(led_set_brightness_sync);

/*
 * This is a led-core function because just like led_set_brightness()
 * it is used in the kernel by e.g. triggers.
 */
void led_mc_set_brightness(struct led_classdev *led_cdev,
			   unsigned int *intensity_value, unsigned int num_colors,
			   unsigned int brightness)
{
	struct led_classdev_mc *mcled_cdev;
	unsigned int i;

	if (!(led_cdev->flags & LED_MULTI_COLOR)) {
		dev_err_once(led_cdev->dev, "error not a multi-color LED\n");
		return;
	}

	mcled_cdev = lcdev_to_mccdev(led_cdev);
	if (num_colors != mcled_cdev->num_colors) {
		dev_err_once(led_cdev->dev, "error num_colors mismatch %u != %u\n",
			     num_colors, mcled_cdev->num_colors);
		return;
	}

	for (i = 0; i < mcled_cdev->num_colors; i++)
		mcled_cdev->subled_info[i].intensity = intensity_value[i];

	led_set_brightness(led_cdev, brightness);
}
EXPORT_SYMBOL_GPL(led_mc_set_brightness);

int led_update_brightness(struct led_classdev *led_cdev)
{
	int ret;

	if (led_cdev->brightness_get) {
		ret = led_cdev->brightness_get(led_cdev);
		if (ret < 0)
			return ret;

		led_cdev->brightness = ret;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(led_update_brightness);

u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size)
{
	struct fwnode_handle *fwnode = led_cdev->dev->fwnode;
	u32 *pattern;
	int count;

	count = fwnode_property_count_u32(fwnode, "led-pattern");
	if (count < 0)
		return NULL;

	pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL);
	if (!pattern)
		return NULL;

	if (fwnode_property_read_u32_array(fwnode, "led-pattern", pattern, count)) {
		kfree(pattern);
		return NULL;
	}

	*size = count;

	return pattern;
}
EXPORT_SYMBOL_GPL(led_get_default_pattern);

/* Caller must ensure led_cdev->led_access held */
void led_sysfs_disable(struct led_classdev *led_cdev)
{
	lockdep_assert_held(&led_cdev->led_access);

	led_cdev->flags |= LED_SYSFS_DISABLE;
}
EXPORT_SYMBOL_GPL(led_sysfs_disable);

/* Caller must ensure led_cdev->led_access held */
void led_sysfs_enable(struct led_classdev *led_cdev)
{
	lockdep_assert_held(&led_cdev->led_access);

	led_cdev->flags &= ~LED_SYSFS_DISABLE;
}
EXPORT_SYMBOL_GPL(led_sysfs_enable);

static void led_parse_fwnode_props(struct device *dev,
				   struct fwnode_handle *fwnode,
				   struct led_properties *props)
{
	int ret;

	if (!fwnode)
		return;

	if (fwnode_property_present(fwnode, "label")) {
		ret = fwnode_property_read_string(fwnode, "label", &props->label);
		if (ret)
			dev_err(dev, "Error parsing 'label' property (%d)\n", ret);
		return;
	}

	if (fwnode_property_present(fwnode, "color")) {
		ret = fwnode_property_read_u32(fwnode, "color", &props->color);
		if (ret)
			dev_err(dev, "Error parsing 'color' property (%d)\n", ret);
		else if (props->color >= LED_COLOR_ID_MAX)
			dev_err(dev, "LED color identifier out of range\n");
		else
			props->color_present = true;
	}


	if (!fwnode_property_present(fwnode, "function"))
		return;

	ret = fwnode_property_read_string(fwnode, "function", &props->function);
	if (ret) {
		dev_err(dev,
			"Error parsing 'function' property (%d)\n",
			ret);
	}

	if (!fwnode_property_present(fwnode, "function-enumerator"))
		return;

	ret = fwnode_property_read_u32(fwnode, "function-enumerator",
				       &props->func_enum);
	if (ret) {
		dev_err(dev,
			"Error parsing 'function-enumerator' property (%d)\n",
			ret);
	} else {
		props->func_enum_present = true;
	}
}

int led_compose_name(struct device *dev, struct led_init_data *init_data,
		     char *led_classdev_name)
{
	struct led_properties props = {};
	struct fwnode_handle *fwnode = init_data->fwnode;
	const char *devicename = init_data->devicename;
	int n;

	if (!led_classdev_name)
		return -EINVAL;

	led_parse_fwnode_props(dev, fwnode, &props);

	if (props.label) {
		/*
		 * If init_data.devicename is NULL, then it indicates that
		 * DT label should be used as-is for LED class device name.
		 * Otherwise the label is prepended with devicename to compose
		 * the final LED class device name.
		 */
		if (devicename) {
			n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
				     devicename, props.label);
		} else {
			n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s", props.label);
		}
	} else if (props.function || props.color_present) {
		char tmp_buf[LED_MAX_NAME_SIZE];

		if (props.func_enum_present) {
			n = snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s-%d",
				     props.color_present ? led_colors[props.color] : "",
				     props.function ?: "", props.func_enum);
		} else {
			n = snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s",
				     props.color_present ? led_colors[props.color] : "",
				     props.function ?: "");
		}
		if (n >= LED_MAX_NAME_SIZE)
			return -E2BIG;

		if (init_data->devname_mandatory) {
			n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
				     devicename, tmp_buf);
		} else {
			n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s", tmp_buf);
		}
	} else if (init_data->default_label) {
		if (!devicename) {
			dev_err(dev, "Legacy LED naming requires devicename segment");
			return -EINVAL;
		}
		n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
			     devicename, init_data->default_label);
	} else if (is_of_node(fwnode)) {
		n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s",
			     to_of_node(fwnode)->name);
	} else
		return -EINVAL;

	if (n >= LED_MAX_NAME_SIZE)
		return -E2BIG;

	return 0;
}
EXPORT_SYMBOL_GPL(led_compose_name);

const char *led_get_color_name(u8 color_id)
{
	if (color_id >= ARRAY_SIZE(led_colors))
		return NULL;

	return led_colors[color_id];
}
EXPORT_SYMBOL_GPL(led_get_color_name);

enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode)
{
	const char *state = NULL;

	if (!fwnode_property_read_string(fwnode, "default-state", &state)) {
		if (!strcmp(state, "keep"))
			return LEDS_DEFSTATE_KEEP;
		if (!strcmp(state, "on"))
			return LEDS_DEFSTATE_ON;
	}

	return LEDS_DEFSTATE_OFF;
}
EXPORT_SYMBOL_GPL(led_init_default_state_get);
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* LED Class Core
	4	*
	5	* Copyright 2005-2006 Openedhand Ltd.
	6	*
	7	* Author: Richard Purdie <rpurdie@openedhand.com>
	8	*/
	9
	10	#include <linux/kernel.h>
	11	#include <linux/led-class-multicolor.h>
	12	#include <linux/leds.h>
	13	#include <linux/list.h>
	14	#include <linux/module.h>
	15	#include <linux/mutex.h>
	16	#include <linux/of.h>
	17	#include <linux/property.h>
	18	#include <linux/rwsem.h>
	19	#include <linux/slab.h>
	20	#include <uapi/linux/uleds.h>
	21	#include "leds.h"
	22
	23	DECLARE_RWSEM(leds_list_lock);
	24	EXPORT_SYMBOL_GPL(leds_list_lock);
	25
	26	LIST_HEAD(leds_list);
	27	EXPORT_SYMBOL_GPL(leds_list);
	28
	29	static const char * const led_colors[LED_COLOR_ID_MAX] = {
	30	[LED_COLOR_ID_WHITE] = "white",
	31	[LED_COLOR_ID_RED] = "red",
	32	[LED_COLOR_ID_GREEN] = "green",
	33	[LED_COLOR_ID_BLUE] = "blue",
	34	[LED_COLOR_ID_AMBER] = "amber",
	35	[LED_COLOR_ID_VIOLET] = "violet",
	36	[LED_COLOR_ID_YELLOW] = "yellow",
	37	[LED_COLOR_ID_IR] = "ir",
	38	[LED_COLOR_ID_MULTI] = "multicolor",
	39	[LED_COLOR_ID_RGB] = "rgb",
	40	[LED_COLOR_ID_PURPLE] = "purple",
	41	[LED_COLOR_ID_ORANGE] = "orange",
	42	[LED_COLOR_ID_PINK] = "pink",
	43	[LED_COLOR_ID_CYAN] = "cyan",
	44	[LED_COLOR_ID_LIME] = "lime",
	45	};
	46
	47	static int __led_set_brightness(struct led_classdev *led_cdev, unsigned int value)
	48	{
	49	if (!led_cdev->brightness_set)
	50	return -ENOTSUPP;
	51
	52	led_cdev->brightness_set(led_cdev, value);
	53
	54	return 0;
	55	}
	56
	57	static int __led_set_brightness_blocking(struct led_classdev *led_cdev, unsigned int value)
	58	{
	59	if (!led_cdev->brightness_set_blocking)
	60	return -ENOTSUPP;
	61
	62	return led_cdev->brightness_set_blocking(led_cdev, value);
	63	}
	64
	65	static void led_timer_function(struct timer_list *t)
	66	{
	67	struct led_classdev *led_cdev = timer_container_of(led_cdev, t,
	68	blink_timer);
	69	unsigned long brightness;
	70	unsigned long delay;
	71
	72	if (!led_cdev->blink_delay_on \|\| !led_cdev->blink_delay_off) {
	73	led_set_brightness_nosleep(led_cdev, LED_OFF);
	74	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
	75	return;
	76	}
	77
	78	if (test_and_clear_bit(LED_BLINK_ONESHOT_STOP,
	79	&led_cdev->work_flags)) {
	80	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
	81	return;
	82	}
	83
	84	brightness = led_get_brightness(led_cdev);
	85	if (!brightness) {
	86	/* Time to switch the LED on. */
	87	if (test_and_clear_bit(LED_BLINK_BRIGHTNESS_CHANGE,
	88	&led_cdev->work_flags))
	89	brightness = led_cdev->new_blink_brightness;
	90	else
	91	brightness = led_cdev->blink_brightness;
	92	delay = led_cdev->blink_delay_on;
	93	} else {
	94	/* Store the current brightness value to be able
	95	* to restore it when the delay_off period is over.
	96	*/
	97	led_cdev->blink_brightness = brightness;
	98	brightness = LED_OFF;
	99	delay = led_cdev->blink_delay_off;
	100	}
	101
	102	led_set_brightness_nosleep(led_cdev, brightness);
	103
	104	/* Return in next iteration if led is in one-shot mode and we are in
	105	* the final blink state so that the led is toggled each delay_on +
	106	* delay_off milliseconds in worst case.
	107	*/
	108	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags)) {
	109	if (test_bit(LED_BLINK_INVERT, &led_cdev->work_flags)) {
	110	if (brightness)
	111	set_bit(LED_BLINK_ONESHOT_STOP,
	112	&led_cdev->work_flags);
	113	} else {
	114	if (!brightness)
	115	set_bit(LED_BLINK_ONESHOT_STOP,
	116	&led_cdev->work_flags);
	117	}
	118	}
	119
	120	mod_timer(&led_cdev->blink_timer, jiffies + msecs_to_jiffies(delay));
	121	}
	122
	123	static void set_brightness_delayed_set_brightness(struct led_classdev *led_cdev,
	124	unsigned int value)
	125	{
	126	int ret;
	127
	128	ret = __led_set_brightness(led_cdev, value);
	129	if (ret == -ENOTSUPP) {
	130	ret = __led_set_brightness_blocking(led_cdev, value);
	131	if (ret == -ENOTSUPP)
	132	/* No back-end support to set a fixed brightness value */
	133	return;
	134	}
	135
	136	/* LED HW might have been unplugged, therefore don't warn */
	137	if (ret == -ENODEV && led_cdev->flags & LED_UNREGISTERING &&
	138	led_cdev->flags & LED_HW_PLUGGABLE)
	139	return;
	140
	141	if (ret < 0)
	142	dev_err(led_cdev->dev,
	143	"Setting an LED's brightness failed (%d)\n", ret);
	144	}
	145
	146	static void set_brightness_delayed(struct work_struct *ws)
	147	{
	148	struct led_classdev *led_cdev =
	149	container_of(ws, struct led_classdev, set_brightness_work);
	150
	151	if (test_and_clear_bit(LED_BLINK_DISABLE, &led_cdev->work_flags)) {
	152	led_stop_software_blink(led_cdev);
	153	set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags);
	154	}
	155
	156	/*
	157	* Triggers may call led_set_brightness(LED_OFF),
	158	* led_set_brightness(LED_FULL) in quick succession to disable blinking
	159	* and turn the LED on. Both actions may have been scheduled to run
	160	* before this work item runs once. To make sure this works properly
	161	* handle LED_SET_BRIGHTNESS_OFF first.
	162	*/
	163	if (test_and_clear_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags)) {
	164	set_brightness_delayed_set_brightness(led_cdev, LED_OFF);
	165	/*
	166	* The consecutives led_set_brightness(LED_OFF),
	167	* led_set_brightness(LED_FULL) could have been executed out of
	168	* order (LED_FULL first), if the work_flags has been set
	169	* between LED_SET_BRIGHTNESS_OFF and LED_SET_BRIGHTNESS of this
	170	* work. To avoid ending with the LED turned off, turn the LED
	171	* on again.
	172	*/
	173	if (led_cdev->delayed_set_value != LED_OFF)
	174	set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
	175	}
	176
	177	if (test_and_clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags))
	178	set_brightness_delayed_set_brightness(led_cdev, led_cdev->delayed_set_value);
	179
	180	if (test_and_clear_bit(LED_SET_BLINK, &led_cdev->work_flags)) {
	181	unsigned long delay_on = led_cdev->delayed_delay_on;
	182	unsigned long delay_off = led_cdev->delayed_delay_off;
	183
	184	led_blink_set(led_cdev, &delay_on, &delay_off);
	185	}
	186	}
	187
	188	static void led_set_software_blink(struct led_classdev *led_cdev,
	189	unsigned long delay_on,
	190	unsigned long delay_off)
	191	{
	192	int current_brightness;
	193
	194	current_brightness = led_get_brightness(led_cdev);
	195	if (current_brightness)
	196	led_cdev->blink_brightness = current_brightness;
	197	if (!led_cdev->blink_brightness)
	198	led_cdev->blink_brightness = led_cdev->max_brightness;
	199
	200	led_cdev->blink_delay_on = delay_on;
	201	led_cdev->blink_delay_off = delay_off;
	202
	203	/* never on - just set to off */
	204	if (!delay_on) {
	205	led_set_brightness_nosleep(led_cdev, LED_OFF);
	206	return;
	207	}
	208
	209	/* never off - just set to brightness */
	210	if (!delay_off) {
	211	led_set_brightness_nosleep(led_cdev,
	212	led_cdev->blink_brightness);
	213	return;
	214	}
	215
	216	set_bit(LED_BLINK_SW, &led_cdev->work_flags);
	217	mod_timer(&led_cdev->blink_timer, jiffies + 1);
	218	}
	219
	220
	221	static void led_blink_setup(struct led_classdev *led_cdev,
	222	unsigned long *delay_on,
	223	unsigned long *delay_off)
	224	{
	225	if (!test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	226	led_cdev->blink_set &&
	227	!led_cdev->blink_set(led_cdev, delay_on, delay_off))
	228	return;
	229
	230	/* blink with 1 Hz as default if nothing specified */
	231	if (!delay_on && !delay_off)
	232	delay_on = delay_off = 500;
	233
	234	led_set_software_blink(led_cdev, delay_on, delay_off);
	235	}
	236
	237	void led_init_core(struct led_classdev *led_cdev)
	238	{
	239	INIT_WORK(&led_cdev->set_brightness_work, set_brightness_delayed);
	240
	241	timer_setup(&led_cdev->blink_timer, led_timer_function, 0);
	242	}
	243	EXPORT_SYMBOL_GPL(led_init_core);
	244
	245	void led_blink_set(struct led_classdev *led_cdev,
	246	unsigned long *delay_on,
	247	unsigned long *delay_off)
	248	{
	249	timer_delete_sync(&led_cdev->blink_timer);
	250
	251	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
	252	clear_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	253	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
	254
	255	led_blink_setup(led_cdev, delay_on, delay_off);
	256	}
	257	EXPORT_SYMBOL_GPL(led_blink_set);
	258
	259	void led_blink_set_oneshot(struct led_classdev *led_cdev,
	260	unsigned long *delay_on,
	261	unsigned long *delay_off,
	262	int invert)
	263	{
	264	if (test_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags) &&
	265	timer_pending(&led_cdev->blink_timer))
	266	return;
	267
	268	set_bit(LED_BLINK_ONESHOT, &led_cdev->work_flags);
	269	clear_bit(LED_BLINK_ONESHOT_STOP, &led_cdev->work_flags);
	270
	271	if (invert)
	272	set_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
	273	else
	274	clear_bit(LED_BLINK_INVERT, &led_cdev->work_flags);
	275
	276	led_blink_setup(led_cdev, delay_on, delay_off);
	277	}
	278	EXPORT_SYMBOL_GPL(led_blink_set_oneshot);
	279
	280	void led_blink_set_nosleep(struct led_classdev *led_cdev, unsigned long delay_on,
	281	unsigned long delay_off)
	282	{
	283	/* If necessary delegate to a work queue task. */
	284	if (led_cdev->blink_set && led_cdev->brightness_set_blocking) {
	285	led_cdev->delayed_delay_on = delay_on;
	286	led_cdev->delayed_delay_off = delay_off;
	287	set_bit(LED_SET_BLINK, &led_cdev->work_flags);
	288	queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
	289	return;
	290	}
	291
	292	led_blink_set(led_cdev, &delay_on, &delay_off);
	293	}
	294	EXPORT_SYMBOL_GPL(led_blink_set_nosleep);
	295
	296	void led_stop_software_blink(struct led_classdev *led_cdev)
	297	{
	298	timer_delete_sync(&led_cdev->blink_timer);
	299	led_cdev->blink_delay_on = 0;
	300	led_cdev->blink_delay_off = 0;
	301	clear_bit(LED_BLINK_SW, &led_cdev->work_flags);
	302	}
	303	EXPORT_SYMBOL_GPL(led_stop_software_blink);
	304
	305	void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness)
	306	{
	307	/*
	308	* If software blink is active, delay brightness setting
	309	* until the next timer tick.
	310	*/
	311	if (test_bit(LED_BLINK_SW, &led_cdev->work_flags)) {
	312	/*
	313	* If we need to disable soft blinking delegate this to the
	314	* work queue task to avoid problems in case we are called
	315	* from hard irq context.
	316	*/
	317	if (!brightness) {
	318	set_bit(LED_BLINK_DISABLE, &led_cdev->work_flags);
	319	queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
	320	} else {
	321	set_bit(LED_BLINK_BRIGHTNESS_CHANGE,
	322	&led_cdev->work_flags);
	323	led_cdev->new_blink_brightness = brightness;
	324	}
	325	return;
	326	}
	327
	328	led_set_brightness_nosleep(led_cdev, brightness);
	329	}
	330	EXPORT_SYMBOL_GPL(led_set_brightness);
	331
	332	void led_set_brightness_nopm(struct led_classdev *led_cdev, unsigned int value)
	333	{
	334	/* Use brightness_set op if available, it is guaranteed not to sleep */
	335	if (!__led_set_brightness(led_cdev, value))
	336	return;
	337
	338	/*
	339	* Brightness setting can sleep, delegate it to a work queue task.
	340	* value 0 / LED_OFF is special, since it also disables hw-blinking
	341	* (sw-blink disable is handled in led_set_brightness()).
	342	* To avoid a hw-blink-disable getting lost when a second brightness
	343	* change is done immediately afterwards (before the work runs),
	344	* it uses a separate work_flag.
	345	*/
	346	led_cdev->delayed_set_value = value;
	347	/* Ensure delayed_set_value is seen before work_flags modification */
	348	smp_mb__before_atomic();
	349
	350	if (value)
	351	set_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
	352	else {
	353	clear_bit(LED_SET_BRIGHTNESS, &led_cdev->work_flags);
	354	clear_bit(LED_SET_BLINK, &led_cdev->work_flags);
	355	set_bit(LED_SET_BRIGHTNESS_OFF, &led_cdev->work_flags);
	356	}
	357
	358	queue_work(led_cdev->wq, &led_cdev->set_brightness_work);
	359	}
	360	EXPORT_SYMBOL_GPL(led_set_brightness_nopm);
	361
	362	void led_set_brightness_nosleep(struct led_classdev *led_cdev, unsigned int value)
	363	{
	364	led_cdev->brightness = min(value, led_cdev->max_brightness);
	365
	366	if (led_cdev->flags & LED_SUSPENDED)
	367	return;
	368
	369	led_set_brightness_nopm(led_cdev, led_cdev->brightness);
	370	}
	371	EXPORT_SYMBOL_GPL(led_set_brightness_nosleep);
	372
	373	int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value)
	374	{
	375	if (led_cdev->blink_delay_on \|\| led_cdev->blink_delay_off)
	376	return -EBUSY;
	377
	378	led_cdev->brightness = min(value, led_cdev->max_brightness);
	379
	380	if (led_cdev->flags & LED_SUSPENDED)
	381	return 0;
	382
	383	return __led_set_brightness_blocking(led_cdev, led_cdev->brightness);
	384	}
	385	EXPORT_SYMBOL_GPL(led_set_brightness_sync);
	386
	387	/*
	388	* This is a led-core function because just like led_set_brightness()
	389	* it is used in the kernel by e.g. triggers.
	390	*/
	391	void led_mc_set_brightness(struct led_classdev *led_cdev,
	392	unsigned int *intensity_value, unsigned int num_colors,
	393	unsigned int brightness)
	394	{
	395	struct led_classdev_mc *mcled_cdev;
	396	unsigned int i;
	397
	398	if (!(led_cdev->flags & LED_MULTI_COLOR)) {
	399	dev_err_once(led_cdev->dev, "error not a multi-color LED\n");
	400	return;
	401	}
	402
	403	mcled_cdev = lcdev_to_mccdev(led_cdev);
	404	if (num_colors != mcled_cdev->num_colors) {
	405	dev_err_once(led_cdev->dev, "error num_colors mismatch %u != %u\n",
	406	num_colors, mcled_cdev->num_colors);
	407	return;
	408	}
	409
	410	for (i = 0; i < mcled_cdev->num_colors; i++)
	411	mcled_cdev->subled_info[i].intensity = intensity_value[i];
	412
	413	led_set_brightness(led_cdev, brightness);
	414	}
	415	EXPORT_SYMBOL_GPL(led_mc_set_brightness);
	416
	417	int led_update_brightness(struct led_classdev *led_cdev)
	418	{
	419	int ret;
	420
	421	if (led_cdev->brightness_get) {
	422	ret = led_cdev->brightness_get(led_cdev);
	423	if (ret < 0)
	424	return ret;
	425
	426	led_cdev->brightness = ret;
	427	}
	428
	429	return 0;
	430	}
	431	EXPORT_SYMBOL_GPL(led_update_brightness);
	432
	433	u32 led_get_default_pattern(struct led_classdev led_cdev, unsigned int *size)
	434	{
	435	struct fwnode_handle *fwnode = led_cdev->dev->fwnode;
	436	u32 *pattern;
	437	int count;
	438
	439	count = fwnode_property_count_u32(fwnode, "led-pattern");
	440	if (count < 0)
	441	return NULL;
	442
	443	pattern = kcalloc(count, sizeof(*pattern), GFP_KERNEL);
	444	if (!pattern)
	445	return NULL;
	446
	447	if (fwnode_property_read_u32_array(fwnode, "led-pattern", pattern, count)) {
	448	kfree(pattern);
	449	return NULL;
	450	}
	451
	452	*size = count;
	453
	454	return pattern;
	455	}
	456	EXPORT_SYMBOL_GPL(led_get_default_pattern);
	457
	458	/* Caller must ensure led_cdev->led_access held */
	459	void led_sysfs_disable(struct led_classdev *led_cdev)
	460	{
	461	lockdep_assert_held(&led_cdev->led_access);
	462
	463	led_cdev->flags \|= LED_SYSFS_DISABLE;
	464	}
	465	EXPORT_SYMBOL_GPL(led_sysfs_disable);
	466
	467	/* Caller must ensure led_cdev->led_access held */
	468	void led_sysfs_enable(struct led_classdev *led_cdev)
	469	{
	470	lockdep_assert_held(&led_cdev->led_access);
	471
	472	led_cdev->flags &= ~LED_SYSFS_DISABLE;
	473	}
	474	EXPORT_SYMBOL_GPL(led_sysfs_enable);
	475
	476	static void led_parse_fwnode_props(struct device *dev,
	477	struct fwnode_handle *fwnode,
	478	struct led_properties *props)
	479	{
	480	int ret;
	481
	482	if (!fwnode)
	483	return;
	484
	485	if (fwnode_property_present(fwnode, "label")) {
	486	ret = fwnode_property_read_string(fwnode, "label", &props->label);
	487	if (ret)
	488	dev_err(dev, "Error parsing 'label' property (%d)\n", ret);
	489	return;
	490	}
	491
	492	if (fwnode_property_present(fwnode, "color")) {
	493	ret = fwnode_property_read_u32(fwnode, "color", &props->color);
	494	if (ret)
	495	dev_err(dev, "Error parsing 'color' property (%d)\n", ret);
	496	else if (props->color >= LED_COLOR_ID_MAX)
	497	dev_err(dev, "LED color identifier out of range\n");
	498	else
	499	props->color_present = true;
	500	}
	501
	502
	503	if (!fwnode_property_present(fwnode, "function"))
	504	return;
	505
	506	ret = fwnode_property_read_string(fwnode, "function", &props->function);
	507	if (ret) {
	508	dev_err(dev,
	509	"Error parsing 'function' property (%d)\n",
	510	ret);
	511	}
	512
	513	if (!fwnode_property_present(fwnode, "function-enumerator"))
	514	return;
	515
	516	ret = fwnode_property_read_u32(fwnode, "function-enumerator",
	517	&props->func_enum);
	518	if (ret) {
	519	dev_err(dev,
	520	"Error parsing 'function-enumerator' property (%d)\n",
	521	ret);
	522	} else {
	523	props->func_enum_present = true;
	524	}
	525	}
	526
	527	int led_compose_name(struct device dev, struct led_init_data init_data,
	528	char *led_classdev_name)
	529	{
	530	struct led_properties props = {};
	531	struct fwnode_handle *fwnode = init_data->fwnode;
	532	const char *devicename = init_data->devicename;
	533	int n;
	534
	535	if (!led_classdev_name)
	536	return -EINVAL;
	537
	538	led_parse_fwnode_props(dev, fwnode, &props);
	539
	540	if (props.label) {
	541	/*
	542	* If init_data.devicename is NULL, then it indicates that
	543	* DT label should be used as-is for LED class device name.
	544	* Otherwise the label is prepended with devicename to compose
	545	* the final LED class device name.
	546	*/
	547	if (devicename) {
	548	n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
	549	devicename, props.label);
	550	} else {
	551	n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s", props.label);
	552	}
	553	} else if (props.function \|\| props.color_present) {
	554	char tmp_buf[LED_MAX_NAME_SIZE];
	555
	556	if (props.func_enum_present) {
	557	n = snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s-%d",
	558	props.color_present ? led_colors[props.color] : "",
	559	props.function ?: "", props.func_enum);
	560	} else {
	561	n = snprintf(tmp_buf, LED_MAX_NAME_SIZE, "%s:%s",
	562	props.color_present ? led_colors[props.color] : "",
	563	props.function ?: "");
	564	}
	565	if (n >= LED_MAX_NAME_SIZE)
	566	return -E2BIG;
	567
	568	if (init_data->devname_mandatory) {
	569	n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
	570	devicename, tmp_buf);
	571	} else {
	572	n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s", tmp_buf);
	573	}
	574	} else if (init_data->default_label) {
	575	if (!devicename) {
	576	dev_err(dev, "Legacy LED naming requires devicename segment");
	577	return -EINVAL;
	578	}
	579	n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s:%s",
	580	devicename, init_data->default_label);
	581	} else if (is_of_node(fwnode)) {
	582	n = snprintf(led_classdev_name, LED_MAX_NAME_SIZE, "%s",
	583	to_of_node(fwnode)->name);
	584	} else
	585	return -EINVAL;
	586
	587	if (n >= LED_MAX_NAME_SIZE)
	588	return -E2BIG;
	589
	590	return 0;
	591	}
	592	EXPORT_SYMBOL_GPL(led_compose_name);
	593
	594	const char *led_get_color_name(u8 color_id)
	595	{
	596	if (color_id >= ARRAY_SIZE(led_colors))
	597	return NULL;
	598
	599	return led_colors[color_id];
	600	}
	601	EXPORT_SYMBOL_GPL(led_get_color_name);
	602
	603	enum led_default_state led_init_default_state_get(struct fwnode_handle *fwnode)
	604	{
	605	const char *state = NULL;
	606
	607	if (!fwnode_property_read_string(fwnode, "default-state", &state)) {
	608	if (!strcmp(state, "keep"))
	609	return LEDS_DEFSTATE_KEEP;
	610	if (!strcmp(state, "on"))
	611	return LEDS_DEFSTATE_ON;
	612	}
	613
	614	return LEDS_DEFSTATE_OFF;
	615	}
	616	EXPORT_SYMBOL_GPL(led_init_default_state_get);