leds.h

Go to the documentation of this file.

/*
 * Driver model for leds and led triggers
 *
 * Copyright (C) 2005 John Lenz <[email protected]>
 * Copyright (C) 2005 Richard Purdie <[email protected]>
 *
 * 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.
 *
 */
#ifndef __LINUX_LEDS_H_INCLUDED
#define __LINUX_LEDS_H_INCLUDED

#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/timer.h>
#include <linux/workqueue.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)
#define LED_BLINK_ONESHOT   (1 << 17)
#define LED_BLINK_ONESHOT_STOP  (1 << 18)
#define LED_BLINK_INVERT    (1 << 19)

    /* 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;

    struct work_struct  set_brightness_work;
    int         delayed_set_value;

#ifdef CONFIG_LEDS_TRIGGERS
    /* 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;
#endif
};

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);

extern void led_blink_set(struct led_classdev *led_cdev,
              unsigned long *delay_on,
              unsigned long *delay_off);
extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
                  unsigned long *delay_on,
                  unsigned long *delay_off,
                  int invert);
extern void led_set_brightness(struct led_classdev *led_cdev,
                   enum led_brightness brightness);

/*
 * LED Triggers
 */
#ifdef CONFIG_LEDS_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);
extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
                      unsigned long *delay_on,
                      unsigned long *delay_off,
                      int invert);

#else

/* Triggers aren't active - null macros */
#define DEFINE_LED_TRIGGER(x)
#define DEFINE_LED_TRIGGER_GLOBAL(x)
#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)

#endif

/* Trigger specific functions */
#ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
extern void ledtrig_ide_activity(void);
#else
#define ledtrig_ide_activity() do {} while(0)
#endif

/*
 * 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) */
};
#define LEDS_GPIO_DEFSTATE_OFF      0
#define LEDS_GPIO_DEFSTATE_ON       1
#define LEDS_GPIO_DEFSTATE_KEEP     2

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);

enum cpu_led_event {
    CPU_LED_IDLE_START, /* CPU enters idle */
    CPU_LED_IDLE_END,   /* CPU idle ends */
    CPU_LED_START,      /* Machine starts, especially resume */
    CPU_LED_STOP,       /* Machine stops, especially suspend */
    CPU_LED_HALTED,     /* Machine shutdown */
};
#ifdef CONFIG_LEDS_TRIGGER_CPU
extern void ledtrig_cpu(enum cpu_led_event evt);
#else
static inline void ledtrig_cpu(enum cpu_led_event evt)
{
    return;
}
#endif

#endif      /* __LINUX_LEDS_H_INCLUDED */