blob: 39eee41d8c6f4deee39d6904087a567657a2349e [file] [log] [blame]
* Driver model for leds and led triggers
* Copyright (C) 2005 John Lenz <>
* Copyright (C) 2005 Richard Purdie <>
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/timer.h>
struct device;
* LED Core
enum led_brightness {
LED_OFF = 0,
LED_HALF = 127,
LED_FULL = 255,
struct led_classdev {
const char *name;
int brightness;
int max_brightness;
int flags;
/* Lower 16 bits reflect status */
#define LED_SUSPENDED (1 << 0)
/* Upper 16 bits reflect control information */
#define LED_CORE_SUSPENDRESUME (1 << 16)
/* Set LED brightness level */
/* Must not sleep, use a workqueue if needed */
void (*brightness_set)(struct led_classdev *led_cdev,
enum led_brightness brightness);
/* Get LED brightness level */
enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
* Activate hardware accelerated blink, delays are in milliseconds
* and if both are zero then a sensible default should be chosen.
* The call should adjust the timings in that case and if it can't
* match the values specified exactly.
* Deactivate blinking again when the brightness is set to a fixed
* value via the brightness_set() callback.
int (*blink_set)(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off);
struct device *dev;
struct list_head node; /* LED Device list */
const char *default_trigger; /* Trigger to use */
unsigned long blink_delay_on, blink_delay_off;
struct timer_list blink_timer;
int blink_brightness;
/* Protects the trigger data below */
struct rw_semaphore trigger_lock;
struct led_trigger *trigger;
struct list_head trig_list;
void *trigger_data;
/* true if activated - deactivate routine uses it to do cleanup */
bool activated;
extern int led_classdev_register(struct device *parent,
struct led_classdev *led_cdev);
extern void led_classdev_unregister(struct led_classdev *led_cdev);
extern void led_classdev_suspend(struct led_classdev *led_cdev);
extern void led_classdev_resume(struct led_classdev *led_cdev);
* led_blink_set - set blinking with software fallback
* @led_cdev: the LED to start blinking
* @delay_on: the time it should be on (in ms)
* @delay_off: the time it should ble off (in ms)
* This function makes the LED blink, attempting to use the
* hardware acceleration if possible, but falling back to
* software blinking if there is no hardware blinking or if
* the LED refuses the passed values.
* Note that if software blinking is active, simply calling
* led_cdev->brightness_set() will not stop the blinking,
* use led_classdev_brightness_set() instead.
extern void led_blink_set(struct led_classdev *led_cdev,
unsigned long *delay_on,
unsigned long *delay_off);
* led_brightness_set - set LED brightness
* @led_cdev: the LED to set
* @brightness: the brightness to set it to
* Set an LED's brightness, and, if necessary, cancel the
* software blink timer that implements blinking when the
* hardware doesn't.
extern void led_brightness_set(struct led_classdev *led_cdev,
enum led_brightness brightness);
* LED Triggers
#define TRIG_NAME_MAX 50
struct led_trigger {
/* Trigger Properties */
const char *name;
void (*activate)(struct led_classdev *led_cdev);
void (*deactivate)(struct led_classdev *led_cdev);
/* LEDs under control by this trigger (for simple triggers) */
rwlock_t leddev_list_lock;
struct list_head led_cdevs;
/* Link to next registered trigger */
struct list_head next_trig;
/* Registration functions for complex triggers */
extern int led_trigger_register(struct led_trigger *trigger);
extern void led_trigger_unregister(struct led_trigger *trigger);
/* Registration functions for simple triggers */
#define DEFINE_LED_TRIGGER(x) static struct led_trigger *x;
#define DEFINE_LED_TRIGGER_GLOBAL(x) struct led_trigger *x;
extern void led_trigger_register_simple(const char *name,
struct led_trigger **trigger);
extern void led_trigger_unregister_simple(struct led_trigger *trigger);
extern void led_trigger_event(struct led_trigger *trigger,
enum led_brightness event);
extern void led_trigger_blink(struct led_trigger *trigger,
unsigned long *delay_on,
unsigned long *delay_off);
/* Triggers aren't active - null macros */
#define led_trigger_register_simple(x, y) do {} while(0)
#define led_trigger_unregister_simple(x) do {} while(0)
#define led_trigger_event(x, y) do {} while(0)
/* Trigger specific functions */
extern void ledtrig_ide_activity(void);
#define ledtrig_ide_activity() do {} while(0)
* Generic LED platform data for describing LED names and default triggers.
struct led_info {
const char *name;
const char *default_trigger;
int flags;
struct led_platform_data {
int num_leds;
struct led_info *leds;
/* For the leds-gpio driver */
struct gpio_led {
const char *name;
const char *default_trigger;
unsigned gpio;
unsigned active_low : 1;
unsigned retain_state_suspended : 1;
unsigned default_state : 2;
/* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
struct gpio_led_platform_data {
int num_leds;
const struct gpio_led *leds;
#define GPIO_LED_NO_BLINK_LOW 0 /* No blink GPIO state low */
#define GPIO_LED_NO_BLINK_HIGH 1 /* No blink GPIO state high */
#define GPIO_LED_BLINK 2 /* Please, blink */
int (*gpio_blink_set)(unsigned gpio, int state,
unsigned long *delay_on,
unsigned long *delay_off);
struct platform_device *gpio_led_register_device(
int id, const struct gpio_led_platform_data *pdata);
#endif /* __LINUX_LEDS_H_INCLUDED */