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