LXR linux/include/linux/leds.h

   1/*
   2 * Driver model for leds and led triggers
   3 *
   4 * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
   5 * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
   6 *
   7 * This program is free software; you can redistribute it and/or modify
   8 * it under the terms of the GNU General Public License version 2 as
   9 * published by the Free Software Foundation.
  10 *
  11 */
  12#ifndef __LINUX_LEDS_H_INCLUDED
  13#define __LINUX_LEDS_H_INCLUDED
  14
  15#include <linux/list.h>
  16#include <linux/spinlock.h>
  17#include <linux/rwsem.h>
  18#include <linux/timer.h>
  19
  20struct device;
  21/*
  22 * LED Core
  23 */
  24
  25enum led_brightness {
  26        LED_OFF         = 0,
  27        LED_HALF        = 127,
  28        LED_FULL        = 255,
  29};
  30
  31struct led_classdev {
  32        const char              *name;
  33        int                      brightness;
  34        int                      max_brightness;
  35        int                      flags;
  36
  37        /* Lower 16 bits reflect status */
  38#define LED_SUSPENDED           (1 << 0)
  39        /* Upper 16 bits reflect control information */
  40#define LED_CORE_SUSPENDRESUME  (1 << 16)
  41
  42        /* Set LED brightness level */
  43        /* Must not sleep, use a workqueue if needed */
  44        void            (*brightness_set)(struct led_classdev *led_cdev,
  45                                          enum led_brightness brightness);
  46        /* Get LED brightness level */
  47        enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  48
  49        /*
  50         * Activate hardware accelerated blink, delays are in milliseconds
  51         * and if both are zero then a sensible default should be chosen.
  52         * The call should adjust the timings in that case and if it can't
  53         * match the values specified exactly.
  54         * Deactivate blinking again when the brightness is set to a fixed
  55         * value via the brightness_set() callback.
  56         */
  57        int             (*blink_set)(struct led_classdev *led_cdev,
  58                                     unsigned long *delay_on,
  59                                     unsigned long *delay_off);
  60
  61        struct device           *dev;
  62        struct list_head         node;                  /* LED Device list */
  63        const char              *default_trigger;       /* Trigger to use */
  64
  65        unsigned long            blink_delay_on, blink_delay_off;
  66        struct timer_list        blink_timer;
  67        int                      blink_brightness;
  68
  69#ifdef CONFIG_LEDS_TRIGGERS
  70        /* Protects the trigger data below */
  71        struct rw_semaphore      trigger_lock;
  72
  73        struct led_trigger      *trigger;
  74        struct list_head         trig_list;
  75        void                    *trigger_data;
  76#endif
  77};
  78
  79extern int led_classdev_register(struct device *parent,
  80                                 struct led_classdev *led_cdev);
  81extern void led_classdev_unregister(struct led_classdev *led_cdev);
  82extern void led_classdev_suspend(struct led_classdev *led_cdev);
  83extern void led_classdev_resume(struct led_classdev *led_cdev);
  84
  85/**
  86 * led_blink_set - set blinking with software fallback
  87 * @led_cdev: the LED to start blinking
  88 * @delay_on: the time it should be on (in ms)
  89 * @delay_off: the time it should ble off (in ms)
  90 *
  91 * This function makes the LED blink, attempting to use the
  92 * hardware acceleration if possible, but falling back to
  93 * software blinking if there is no hardware blinking or if
  94 * the LED refuses the passed values.
  95 *
  96 * Note that if software blinking is active, simply calling
  97 * led_cdev->brightness_set() will not stop the blinking,
  98 * use led_classdev_brightness_set() instead.
  99 */
 100extern void led_blink_set(struct led_classdev *led_cdev,
 101                          unsigned long *delay_on,
 102                          unsigned long *delay_off);
 103/**
 104 * led_brightness_set - set LED brightness
 105 * @led_cdev: the LED to set
 106 * @brightness: the brightness to set it to
 107 *
 108 * Set an LED's brightness, and, if necessary, cancel the
 109 * software blink timer that implements blinking when the
 110 * hardware doesn't.
 111 */
 112extern void led_brightness_set(struct led_classdev *led_cdev,
 113                               enum led_brightness brightness);
 114
 115/*
 116 * LED Triggers
 117 */
 118#ifdef CONFIG_LEDS_TRIGGERS
 119
 120#define TRIG_NAME_MAX 50
 121
 122struct led_trigger {
 123        /* Trigger Properties */
 124        const char       *name;
 125        void            (*activate)(struct led_classdev *led_cdev);
 126        void            (*deactivate)(struct led_classdev *led_cdev);
 127
 128        /* LEDs under control by this trigger (for simple triggers) */
 129        rwlock_t          leddev_list_lock;
 130        struct list_head  led_cdevs;
 131
 132        /* Link to next registered trigger */
 133        struct list_head  next_trig;
 134};
 135
 136/* Registration functions for complex triggers */
 137extern int led_trigger_register(struct led_trigger *trigger);
 138extern void led_trigger_unregister(struct led_trigger *trigger);
 139
 140/* Registration functions for simple triggers */
 141#define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 142#define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 143extern void led_trigger_register_simple(const char *name,
 144                                struct led_trigger **trigger);
 145extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 146extern void led_trigger_event(struct led_trigger *trigger,
 147                                enum led_brightness event);
 148extern void led_trigger_blink(struct led_trigger *trigger,
 149                              unsigned long *delay_on,
 150                              unsigned long *delay_off);
 151
 152#else
 153
 154/* Triggers aren't active - null macros */
 155#define DEFINE_LED_TRIGGER(x)
 156#define DEFINE_LED_TRIGGER_GLOBAL(x)
 157#define led_trigger_register_simple(x, y) do {} while(0)
 158#define led_trigger_unregister_simple(x) do {} while(0)
 159#define led_trigger_event(x, y) do {} while(0)
 160
 161#endif
 162
 163/* Trigger specific functions */
 164#ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
 165extern void ledtrig_ide_activity(void);
 166#else
 167#define ledtrig_ide_activity() do {} while(0)
 168#endif
 169
 170/*
 171 * Generic LED platform data for describing LED names and default triggers.
 172 */
 173struct led_info {
 174        const char      *name;
 175        const char      *default_trigger;
 176        int             flags;
 177};
 178
 179struct led_platform_data {
 180        int             num_leds;
 181        struct led_info *leds;
 182};
 183
 184/* For the leds-gpio driver */
 185struct gpio_led {
 186        const char *name;
 187        const char *default_trigger;
 188        unsigned        gpio;
 189        unsigned        active_low : 1;
 190        unsigned        retain_state_suspended : 1;
 191        unsigned        default_state : 2;
 192        /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 193};
 194#define LEDS_GPIO_DEFSTATE_OFF          0
 195#define LEDS_GPIO_DEFSTATE_ON           1
 196#define LEDS_GPIO_DEFSTATE_KEEP         2
 197
 198struct gpio_led_platform_data {
 199        int             num_leds;
 200        const struct gpio_led *leds;
 201
 202#define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 203#define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 204#define GPIO_LED_BLINK          2       /* Please, blink */
 205        int             (*gpio_blink_set)(unsigned gpio, int state,
 206                                        unsigned long *delay_on,
 207                                        unsigned long *delay_off);
 208};
 209
 210struct platform_device *gpio_led_register_device(
 211                int id, const struct gpio_led_platform_data *pdata);
 212
 213#endif          /* __LINUX_LEDS_H_INCLUDED */
 214