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
  20 struct device;
  21 /*
  22  * LED Core
  23  */
  24
  25 enum led_brightness {
  26         LED_OFF         = 0,
  27         LED_HALF        = 127,
  28         LED_FULL        = 255,
  29 };
  30
  31 struct 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
  79 extern int led_classdev_register(struct device *parent,
  80                                  struct led_classdev *led_cdev);
  81 extern void led_classdev_unregister(struct led_classdev *led_cdev);
  82 extern void led_classdev_suspend(struct led_classdev *led_cdev);
  83 extern 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  */
 100 extern 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  */
 112 extern 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
 122 struct 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 */
 137 extern int led_trigger_register(struct led_trigger *trigger);
 138 extern 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;
 143 extern void led_trigger_register_simple(const char *name,
 144                                 struct led_trigger **trigger);
 145 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 146 extern void led_trigger_event(struct led_trigger *trigger,
 147                                 enum led_brightness event);
 148 extern 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
 165 extern 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  */
 173 struct led_info {
 174         const char      *name;
 175         const char      *default_trigger;
 176         int             flags;
 177 };
 178
 179 struct led_platform_data {
 180         int             num_leds;
 181         struct led_info *leds;
 182 };
 183
 184 /* For the leds-gpio driver */
 185 struct 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
 198 struct 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
 210
 211 #endif          /* __LINUX_LEDS_H_INCLUDED */