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/rwsem.h>
  17 #include <linux/spinlock.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         enum led_brightness      brightness;
  35         enum led_brightness      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  * led_update_brightness - update LED brightness
 145  * @led_cdev: the LED to query
 146  *
 147  * Get an LED's current brightness and update led_cdev->brightness
 148  * member with the obtained value.
 149  *
 150  * Returns: 0 on success or negative error value on failure
 151  */
 152 extern int led_update_brightness(struct led_classdev *led_cdev);
 153
 154 /*
 155  * LED Triggers
 156  */
 157 /* Registration functions for simple triggers */
 158 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 159 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 160
 161 #ifdef CONFIG_LEDS_TRIGGERS
 162
 163 #define TRIG_NAME_MAX 50
 164
 165 struct led_trigger {
 166         /* Trigger Properties */
 167         const char       *name;
 168         void            (*activate)(struct led_classdev *led_cdev);
 169         void            (*deactivate)(struct led_classdev *led_cdev);
 170
 171         /* LEDs under control by this trigger (for simple triggers) */
 172         rwlock_t          leddev_list_lock;
 173         struct list_head  led_cdevs;
 174
 175         /* Link to next registered trigger */
 176         struct list_head  next_trig;
 177 };
 178
 179 /* Registration functions for complex triggers */
 180 extern int led_trigger_register(struct led_trigger *trigger);
 181 extern void led_trigger_unregister(struct led_trigger *trigger);
 182
 183 extern void led_trigger_register_simple(const char *name,
 184                                 struct led_trigger **trigger);
 185 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 186 extern void led_trigger_event(struct led_trigger *trigger,
 187                                 enum led_brightness event);
 188 extern void led_trigger_blink(struct led_trigger *trigger,
 189                               unsigned long *delay_on,
 190                               unsigned long *delay_off);
 191 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 192                                       unsigned long *delay_on,
 193                                       unsigned long *delay_off,
 194                                       int invert);
 195 /**
 196  * led_trigger_rename_static - rename a trigger
 197  * @name: the new trigger name
 198  * @trig: the LED trigger to rename
 199  *
 200  * Change a LED trigger name by copying the string passed in
 201  * name into current trigger name, which MUST be large
 202  * enough for the new string.
 203  *
 204  * Note that name must NOT point to the same string used
 205  * during LED registration, as that could lead to races.
 206  *
 207  * This is meant to be used on triggers with statically
 208  * allocated name.
 209  */
 210 extern void led_trigger_rename_static(const char *name,
 211                                       struct led_trigger *trig);
 212
 213 #else
 214
 215 /* Trigger has no members */
 216 struct led_trigger {};
 217
 218 /* Trigger inline empty functions */
 219 static inline void led_trigger_register_simple(const char *name,
 220                                         struct led_trigger **trigger) {}
 221 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 222 static inline void led_trigger_event(struct led_trigger *trigger,
 223                                 enum led_brightness event) {}
 224 #endif /* CONFIG_LEDS_TRIGGERS */
 225
 226 /* Trigger specific functions */
 227 #ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
 228 extern void ledtrig_ide_activity(void);
 229 #else
 230 static inline void ledtrig_ide_activity(void) {}
 231 #endif
 232
 233 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 234 extern void ledtrig_flash_ctrl(bool on);
 235 extern void ledtrig_torch_ctrl(bool on);
 236 #else
 237 static inline void ledtrig_flash_ctrl(bool on) {}
 238 static inline void ledtrig_torch_ctrl(bool on) {}
 239 #endif
 240
 241 /*
 242  * Generic LED platform data for describing LED names and default triggers.
 243  */
 244 struct led_info {
 245         const char      *name;
 246         const char      *default_trigger;
 247         int             flags;
 248 };
 249
 250 struct led_platform_data {
 251         int             num_leds;
 252         struct led_info *leds;
 253 };
 254
 255 /* For the leds-gpio driver */
 256 struct gpio_led {
 257         const char *name;
 258         const char *default_trigger;
 259         unsigned        gpio;
 260         unsigned        active_low : 1;
 261         unsigned        retain_state_suspended : 1;
 262         unsigned        default_state : 2;
 263         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 264 };
 265 #define LEDS_GPIO_DEFSTATE_OFF          0
 266 #define LEDS_GPIO_DEFSTATE_ON           1
 267 #define LEDS_GPIO_DEFSTATE_KEEP         2
 268
 269 struct gpio_led_platform_data {
 270         int             num_leds;
 271         const struct gpio_led *leds;
 272
 273 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 274 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 275 #define GPIO_LED_BLINK          2       /* Please, blink */
 276         int             (*gpio_blink_set)(unsigned gpio, int state,
 277                                         unsigned long *delay_on,
 278                                         unsigned long *delay_off);
 279 };
 280
 281 struct platform_device *gpio_led_register_device(
 282                 int id, const struct gpio_led_platform_data *pdata);
 283
 284 enum cpu_led_event {
 285         CPU_LED_IDLE_START,     /* CPU enters idle */
 286         CPU_LED_IDLE_END,       /* CPU idle ends */
 287         CPU_LED_START,          /* Machine starts, especially resume */
 288         CPU_LED_STOP,           /* Machine stops, especially suspend */
 289         CPU_LED_HALTED,         /* Machine shutdown */
 290 };
 291 #ifdef CONFIG_LEDS_TRIGGER_CPU
 292 extern void ledtrig_cpu(enum cpu_led_event evt);
 293 #else
 294 static inline void ledtrig_cpu(enum cpu_led_event evt)
 295 {
 296         return;
 297 }
 298 #endif
 299
 300 #endif          /* __LINUX_LEDS_H_INCLUDED */