linux/include/linux/leds.h
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   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#include <linux/workqueue.h>
  20
  21struct device;
  22/*
  23 * LED Core
  24 */
  25
  26enum led_brightness {
  27        LED_OFF         = 0,
  28        LED_HALF        = 127,
  29        LED_FULL        = 255,
  30};
  31
  32struct led_classdev {
  33        const char              *name;
  34        int                      brightness;
  35        int                      max_brightness;
  36        int                      flags;
  37
  38        /* Lower 16 bits reflect status */
  39#define LED_SUSPENDED           (1 << 0)
  40        /* Upper 16 bits reflect control information */
  41#define LED_CORE_SUSPENDRESUME  (1 << 16)
  42#define LED_BLINK_ONESHOT       (1 << 17)
  43#define LED_BLINK_ONESHOT_STOP  (1 << 18)
  44#define LED_BLINK_INVERT        (1 << 19)
  45
  46        /* Set LED brightness level */
  47        /* Must not sleep, use a workqueue if needed */
  48        void            (*brightness_set)(struct led_classdev *led_cdev,
  49                                          enum led_brightness brightness);
  50        /* Get LED brightness level */
  51        enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  52
  53        /*
  54         * Activate hardware accelerated blink, delays are in milliseconds
  55         * and if both are zero then a sensible default should be chosen.
  56         * The call should adjust the timings in that case and if it can't
  57         * match the values specified exactly.
  58         * Deactivate blinking again when the brightness is set to a fixed
  59         * value via the brightness_set() callback.
  60         */
  61        int             (*blink_set)(struct led_classdev *led_cdev,
  62                                     unsigned long *delay_on,
  63                                     unsigned long *delay_off);
  64
  65        struct device           *dev;
  66        struct list_head         node;                  /* LED Device list */
  67        const char              *default_trigger;       /* Trigger to use */
  68
  69        unsigned long            blink_delay_on, blink_delay_off;
  70        struct timer_list        blink_timer;
  71        int                      blink_brightness;
  72
  73        struct work_struct      set_brightness_work;
  74        int                     delayed_set_value;
  75
  76#ifdef CONFIG_LEDS_TRIGGERS
  77        /* Protects the trigger data below */
  78        struct rw_semaphore      trigger_lock;
  79
  80        struct led_trigger      *trigger;
  81        struct list_head         trig_list;
  82        void                    *trigger_data;
  83        /* true if activated - deactivate routine uses it to do cleanup */
  84        bool                    activated;
  85#endif
  86};
  87
  88extern int led_classdev_register(struct device *parent,
  89                                 struct led_classdev *led_cdev);
  90extern void led_classdev_unregister(struct led_classdev *led_cdev);
  91extern void led_classdev_suspend(struct led_classdev *led_cdev);
  92extern void led_classdev_resume(struct led_classdev *led_cdev);
  93
  94/**
  95 * led_blink_set - set blinking with software fallback
  96 * @led_cdev: the LED to start blinking
  97 * @delay_on: the time it should be on (in ms)
  98 * @delay_off: the time it should ble off (in ms)
  99 *
 100 * This function makes the LED blink, attempting to use the
 101 * hardware acceleration if possible, but falling back to
 102 * software blinking if there is no hardware blinking or if
 103 * the LED refuses the passed values.
 104 *
 105 * Note that if software blinking is active, simply calling
 106 * led_cdev->brightness_set() will not stop the blinking,
 107 * use led_classdev_brightness_set() instead.
 108 */
 109extern void led_blink_set(struct led_classdev *led_cdev,
 110                          unsigned long *delay_on,
 111                          unsigned long *delay_off);
 112/**
 113 * led_blink_set_oneshot - do a oneshot software blink
 114 * @led_cdev: the LED to start blinking
 115 * @delay_on: the time it should be on (in ms)
 116 * @delay_off: the time it should ble off (in ms)
 117 * @invert: blink off, then on, leaving the led on
 118 *
 119 * This function makes the LED blink one time for delay_on +
 120 * delay_off time, ignoring the request if another one-shot
 121 * blink is already in progress.
 122 *
 123 * If invert is set, led blinks for delay_off first, then for
 124 * delay_on and leave the led on after the on-off cycle.
 125 */
 126extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 127                                  unsigned long *delay_on,
 128                                  unsigned long *delay_off,
 129                                  int invert);
 130/**
 131 * led_set_brightness - set LED brightness
 132 * @led_cdev: the LED to set
 133 * @brightness: the brightness to set it to
 134 *
 135 * Set an LED's brightness, and, if necessary, cancel the
 136 * software blink timer that implements blinking when the
 137 * hardware doesn't.
 138 */
 139extern void led_set_brightness(struct led_classdev *led_cdev,
 140                               enum led_brightness brightness);
 141
 142/*
 143 * LED Triggers
 144 */
 145/* Registration functions for simple triggers */
 146#define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 147#define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 148
 149#ifdef CONFIG_LEDS_TRIGGERS
 150
 151#define TRIG_NAME_MAX 50
 152
 153struct led_trigger {
 154        /* Trigger Properties */
 155        const char       *name;
 156        void            (*activate)(struct led_classdev *led_cdev);
 157        void            (*deactivate)(struct led_classdev *led_cdev);
 158
 159        /* LEDs under control by this trigger (for simple triggers) */
 160        rwlock_t          leddev_list_lock;
 161        struct list_head  led_cdevs;
 162
 163        /* Link to next registered trigger */
 164        struct list_head  next_trig;
 165};
 166
 167/* Registration functions for complex triggers */
 168extern int led_trigger_register(struct led_trigger *trigger);
 169extern void led_trigger_unregister(struct led_trigger *trigger);
 170
 171extern void led_trigger_register_simple(const char *name,
 172                                struct led_trigger **trigger);
 173extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 174extern void led_trigger_event(struct led_trigger *trigger,
 175                                enum led_brightness event);
 176extern void led_trigger_blink(struct led_trigger *trigger,
 177                              unsigned long *delay_on,
 178                              unsigned long *delay_off);
 179extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 180                                      unsigned long *delay_on,
 181                                      unsigned long *delay_off,
 182                                      int invert);
 183/**
 184 * led_trigger_rename_static - rename a trigger
 185 * @name: the new trigger name
 186 * @trig: the LED trigger to rename
 187 *
 188 * Change a LED trigger name by copying the string passed in
 189 * name into current trigger name, which MUST be large
 190 * enough for the new string.
 191 *
 192 * Note that name must NOT point to the same string used
 193 * during LED registration, as that could lead to races.
 194 *
 195 * This is meant to be used on triggers with statically
 196 * allocated name.
 197 */
 198extern void led_trigger_rename_static(const char *name,
 199                                      struct led_trigger *trig);
 200
 201#else
 202
 203/* Trigger has no members */
 204struct led_trigger {};
 205
 206/* Trigger inline empty functions */
 207static inline void led_trigger_register_simple(const char *name,
 208                                        struct led_trigger **trigger) {}
 209static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 210static inline void led_trigger_event(struct led_trigger *trigger,
 211                                enum led_brightness event) {}
 212#endif /* CONFIG_LEDS_TRIGGERS */
 213
 214/* Trigger specific functions */
 215#ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
 216extern void ledtrig_ide_activity(void);
 217#else
 218static inline void ledtrig_ide_activity(void) {}
 219#endif
 220
 221#if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 222extern void ledtrig_flash_ctrl(bool on);
 223extern void ledtrig_torch_ctrl(bool on);
 224#else
 225static inline void ledtrig_flash_ctrl(bool on) {}
 226static inline void ledtrig_torch_ctrl(bool on) {}
 227#endif
 228
 229/*
 230 * Generic LED platform data for describing LED names and default triggers.
 231 */
 232struct led_info {
 233        const char      *name;
 234        const char      *default_trigger;
 235        int             flags;
 236};
 237
 238struct led_platform_data {
 239        int             num_leds;
 240        struct led_info *leds;
 241};
 242
 243/* For the leds-gpio driver */
 244struct gpio_led {
 245        const char *name;
 246        const char *default_trigger;
 247        unsigned        gpio;
 248        unsigned        active_low : 1;
 249        unsigned        retain_state_suspended : 1;
 250        unsigned        default_state : 2;
 251        /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 252};
 253#define LEDS_GPIO_DEFSTATE_OFF          0
 254#define LEDS_GPIO_DEFSTATE_ON           1
 255#define LEDS_GPIO_DEFSTATE_KEEP         2
 256
 257struct gpio_led_platform_data {
 258        int             num_leds;
 259        const struct gpio_led *leds;
 260
 261#define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 262#define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 263#define GPIO_LED_BLINK          2       /* Please, blink */
 264        int             (*gpio_blink_set)(unsigned gpio, int state,
 265                                        unsigned long *delay_on,
 266                                        unsigned long *delay_off);
 267};
 268
 269struct platform_device *gpio_led_register_device(
 270                int id, const struct gpio_led_platform_data *pdata);
 271
 272enum cpu_led_event {
 273        CPU_LED_IDLE_START,     /* CPU enters idle */
 274        CPU_LED_IDLE_END,       /* CPU idle ends */
 275        CPU_LED_START,          /* Machine starts, especially resume */
 276        CPU_LED_STOP,           /* Machine stops, especially suspend */
 277        CPU_LED_HALTED,         /* Machine shutdown */
 278};
 279#ifdef CONFIG_LEDS_TRIGGER_CPU
 280extern void ledtrig_cpu(enum cpu_led_event evt);
 281#else
 282static inline void ledtrig_cpu(enum cpu_led_event evt)
 283{
 284        return;
 285}
 286#endif
 287
 288#endif          /* __LINUX_LEDS_H_INCLUDED */
 289