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/device.h>
  16 #include <linux/list.h>
  17 #include <linux/mutex.h>
  18 #include <linux/rwsem.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/timer.h>
  21 #include <linux/workqueue.h>
  22
  23 struct device;
  24 /*
  25  * LED Core
  26  */
  27
  28 enum led_brightness {
  29         LED_OFF         = 0,
  30         LED_HALF        = 127,
  31         LED_FULL        = 255,
  32 };
  33
  34 struct led_classdev {
  35         const char              *name;
  36         enum led_brightness      brightness;
  37         enum led_brightness      max_brightness;
  38         int                      flags;
  39
  40         /* Lower 16 bits reflect status */
  41 #define LED_SUSPENDED           (1 << 0)
  42         /* Upper 16 bits reflect control information */
  43 #define LED_CORE_SUSPENDRESUME  (1 << 16)
  44 #define LED_BLINK_ONESHOT       (1 << 17)
  45 #define LED_BLINK_ONESHOT_STOP  (1 << 18)
  46 #define LED_BLINK_INVERT        (1 << 19)
  47 #define LED_BLINK_BRIGHTNESS_CHANGE (1 << 20)
  48 #define LED_BLINK_DISABLE       (1 << 21)
  49 #define LED_SYSFS_DISABLE       (1 << 22)
  50 #define SET_BRIGHTNESS_ASYNC    (1 << 23)
  51 #define SET_BRIGHTNESS_SYNC     (1 << 24)
  52 #define LED_DEV_CAP_FLASH       (1 << 25)
  53
  54         /* Set LED brightness level */
  55         /* Must not sleep, use a workqueue if needed */
  56         void            (*brightness_set)(struct led_classdev *led_cdev,
  57                                           enum led_brightness brightness);
  58         /*
  59          * Set LED brightness level immediately - it can block the caller for
  60          * the time required for accessing a LED device register.
  61          */
  62         int             (*brightness_set_sync)(struct led_classdev *led_cdev,
  63                                         enum led_brightness brightness);
  64         /* Get LED brightness level */
  65         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  66
  67         /*
  68          * Activate hardware accelerated blink, delays are in milliseconds
  69          * and if both are zero then a sensible default should be chosen.
  70          * The call should adjust the timings in that case and if it can't
  71          * match the values specified exactly.
  72          * Deactivate blinking again when the brightness is set to a fixed
  73          * value via the brightness_set() callback.
  74          */
  75         int             (*blink_set)(struct led_classdev *led_cdev,
  76                                      unsigned long *delay_on,
  77                                      unsigned long *delay_off);
  78
  79         struct device           *dev;
  80         const struct attribute_group    **groups;
  81
  82         struct list_head         node;                  /* LED Device list */
  83         const char              *default_trigger;       /* Trigger to use */
  84
  85         unsigned long            blink_delay_on, blink_delay_off;
  86         struct timer_list        blink_timer;
  87         int                      blink_brightness;
  88         void                    (*flash_resume)(struct led_classdev *led_cdev);
  89
  90         struct work_struct      set_brightness_work;
  91         int                     delayed_set_value;
  92
  93 #ifdef CONFIG_LEDS_TRIGGERS
  94         /* Protects the trigger data below */
  95         struct rw_semaphore      trigger_lock;
  96
  97         struct led_trigger      *trigger;
  98         struct list_head         trig_list;
  99         void                    *trigger_data;
 100         /* true if activated - deactivate routine uses it to do cleanup */
 101         bool                    activated;
 102 #endif
 103
 104         /* Ensures consistent access to the LED Flash Class device */
 105         struct mutex            led_access;
 106 };
 107
 108 extern int led_classdev_register(struct device *parent,
 109                                  struct led_classdev *led_cdev);
 110 extern int devm_led_classdev_register(struct device *parent,
 111                                       struct led_classdev *led_cdev);
 112 extern void led_classdev_unregister(struct led_classdev *led_cdev);
 113 extern void devm_led_classdev_unregister(struct device *parent,
 114                                          struct led_classdev *led_cdev);
 115 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 116 extern void led_classdev_resume(struct led_classdev *led_cdev);
 117
 118 /**
 119  * led_blink_set - set blinking with software fallback
 120  * @led_cdev: the LED to start blinking
 121  * @delay_on: the time it should be on (in ms)
 122  * @delay_off: the time it should ble off (in ms)
 123  *
 124  * This function makes the LED blink, attempting to use the
 125  * hardware acceleration if possible, but falling back to
 126  * software blinking if there is no hardware blinking or if
 127  * the LED refuses the passed values.
 128  *
 129  * Note that if software blinking is active, simply calling
 130  * led_cdev->brightness_set() will not stop the blinking,
 131  * use led_classdev_brightness_set() instead.
 132  */
 133 extern void led_blink_set(struct led_classdev *led_cdev,
 134                           unsigned long *delay_on,
 135                           unsigned long *delay_off);
 136 /**
 137  * led_blink_set_oneshot - do a oneshot software blink
 138  * @led_cdev: the LED to start blinking
 139  * @delay_on: the time it should be on (in ms)
 140  * @delay_off: the time it should ble off (in ms)
 141  * @invert: blink off, then on, leaving the led on
 142  *
 143  * This function makes the LED blink one time for delay_on +
 144  * delay_off time, ignoring the request if another one-shot
 145  * blink is already in progress.
 146  *
 147  * If invert is set, led blinks for delay_off first, then for
 148  * delay_on and leave the led on after the on-off cycle.
 149  */
 150 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 151                                   unsigned long *delay_on,
 152                                   unsigned long *delay_off,
 153                                   int invert);
 154 /**
 155  * led_set_brightness - set LED brightness
 156  * @led_cdev: the LED to set
 157  * @brightness: the brightness to set it to
 158  *
 159  * Set an LED's brightness, and, if necessary, cancel the
 160  * software blink timer that implements blinking when the
 161  * hardware doesn't.
 162  */
 163 extern void led_set_brightness(struct led_classdev *led_cdev,
 164                                enum led_brightness brightness);
 165 /**
 166  * led_update_brightness - update LED brightness
 167  * @led_cdev: the LED to query
 168  *
 169  * Get an LED's current brightness and update led_cdev->brightness
 170  * member with the obtained value.
 171  *
 172  * Returns: 0 on success or negative error value on failure
 173  */
 174 extern int led_update_brightness(struct led_classdev *led_cdev);
 175
 176 /**
 177  * led_sysfs_disable - disable LED sysfs interface
 178  * @led_cdev: the LED to set
 179  *
 180  * Disable the led_cdev's sysfs interface.
 181  */
 182 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 183
 184 /**
 185  * led_sysfs_enable - enable LED sysfs interface
 186  * @led_cdev: the LED to set
 187  *
 188  * Enable the led_cdev's sysfs interface.
 189  */
 190 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 191
 192 /**
 193  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 194  * @led_cdev: the LED to query
 195  *
 196  * Returns: true if the led_cdev's sysfs interface is disabled.
 197  */
 198 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 199 {
 200         return led_cdev->flags & LED_SYSFS_DISABLE;
 201 }
 202
 203 /*
 204  * LED Triggers
 205  */
 206 /* Registration functions for simple triggers */
 207 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 208 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 209
 210 #ifdef CONFIG_LEDS_TRIGGERS
 211
 212 #define TRIG_NAME_MAX 50
 213
 214 struct led_trigger {
 215         /* Trigger Properties */
 216         const char       *name;
 217         void            (*activate)(struct led_classdev *led_cdev);
 218         void            (*deactivate)(struct led_classdev *led_cdev);
 219
 220         /* LEDs under control by this trigger (for simple triggers) */
 221         rwlock_t          leddev_list_lock;
 222         struct list_head  led_cdevs;
 223
 224         /* Link to next registered trigger */
 225         struct list_head  next_trig;
 226 };
 227
 228 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 229                         const char *buf, size_t count);
 230 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 231                         char *buf);
 232
 233 /* Registration functions for complex triggers */
 234 extern int led_trigger_register(struct led_trigger *trigger);
 235 extern void led_trigger_unregister(struct led_trigger *trigger);
 236
 237 extern void led_trigger_register_simple(const char *name,
 238                                 struct led_trigger **trigger);
 239 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 240 extern void led_trigger_event(struct led_trigger *trigger,
 241                                 enum led_brightness event);
 242 extern void led_trigger_blink(struct led_trigger *trigger,
 243                               unsigned long *delay_on,
 244                               unsigned long *delay_off);
 245 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 246                                       unsigned long *delay_on,
 247                                       unsigned long *delay_off,
 248                                       int invert);
 249 extern void led_trigger_set_default(struct led_classdev *led_cdev);
 250 extern void led_trigger_set(struct led_classdev *led_cdev,
 251                         struct led_trigger *trigger);
 252 extern void led_trigger_remove(struct led_classdev *led_cdev);
 253
 254 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 255 {
 256         return led_cdev->trigger_data;
 257 }
 258
 259 /**
 260  * led_trigger_rename_static - rename a trigger
 261  * @name: the new trigger name
 262  * @trig: the LED trigger to rename
 263  *
 264  * Change a LED trigger name by copying the string passed in
 265  * name into current trigger name, which MUST be large
 266  * enough for the new string.
 267  *
 268  * Note that name must NOT point to the same string used
 269  * during LED registration, as that could lead to races.
 270  *
 271  * This is meant to be used on triggers with statically
 272  * allocated name.
 273  */
 274 extern void led_trigger_rename_static(const char *name,
 275                                       struct led_trigger *trig);
 276
 277 #else
 278
 279 /* Trigger has no members */
 280 struct led_trigger {};
 281
 282 /* Trigger inline empty functions */
 283 static inline void led_trigger_register_simple(const char *name,
 284                                         struct led_trigger **trigger) {}
 285 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 286 static inline void led_trigger_event(struct led_trigger *trigger,
 287                                 enum led_brightness event) {}
 288 static inline void led_trigger_blink(struct led_trigger *trigger,
 289                                       unsigned long *delay_on,
 290                                       unsigned long *delay_off) {}
 291 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 292                                       unsigned long *delay_on,
 293                                       unsigned long *delay_off,
 294                                       int invert) {}
 295 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 296 static inline void led_trigger_set(struct led_classdev *led_cdev,
 297                                 struct led_trigger *trigger) {}
 298 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 299 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 300 {
 301         return NULL;
 302 }
 303
 304 #endif /* CONFIG_LEDS_TRIGGERS */
 305
 306 /* Trigger specific functions */
 307 #ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
 308 extern void ledtrig_ide_activity(void);
 309 #else
 310 static inline void ledtrig_ide_activity(void) {}
 311 #endif
 312
 313 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 314 extern void ledtrig_flash_ctrl(bool on);
 315 extern void ledtrig_torch_ctrl(bool on);
 316 #else
 317 static inline void ledtrig_flash_ctrl(bool on) {}
 318 static inline void ledtrig_torch_ctrl(bool on) {}
 319 #endif
 320
 321 /*
 322  * Generic LED platform data for describing LED names and default triggers.
 323  */
 324 struct led_info {
 325         const char      *name;
 326         const char      *default_trigger;
 327         int             flags;
 328 };
 329
 330 struct led_platform_data {
 331         int             num_leds;
 332         struct led_info *leds;
 333 };
 334
 335 /* For the leds-gpio driver */
 336 struct gpio_led {
 337         const char *name;
 338         const char *default_trigger;
 339         unsigned        gpio;
 340         unsigned        active_low : 1;
 341         unsigned        retain_state_suspended : 1;
 342         unsigned        default_state : 2;
 343         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 344         struct gpio_desc *gpiod;
 345 };
 346 #define LEDS_GPIO_DEFSTATE_OFF          0
 347 #define LEDS_GPIO_DEFSTATE_ON           1
 348 #define LEDS_GPIO_DEFSTATE_KEEP         2
 349
 350 struct gpio_led_platform_data {
 351         int             num_leds;
 352         const struct gpio_led *leds;
 353
 354 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 355 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 356 #define GPIO_LED_BLINK          2       /* Please, blink */
 357         int             (*gpio_blink_set)(struct gpio_desc *desc, int state,
 358                                         unsigned long *delay_on,
 359                                         unsigned long *delay_off);
 360 };
 361
 362 struct platform_device *gpio_led_register_device(
 363                 int id, const struct gpio_led_platform_data *pdata);
 364
 365 enum cpu_led_event {
 366         CPU_LED_IDLE_START,     /* CPU enters idle */
 367         CPU_LED_IDLE_END,       /* CPU idle ends */
 368         CPU_LED_START,          /* Machine starts, especially resume */
 369         CPU_LED_STOP,           /* Machine stops, especially suspend */
 370         CPU_LED_HALTED,         /* Machine shutdown */
 371 };
 372 #ifdef CONFIG_LEDS_TRIGGER_CPU
 373 extern void ledtrig_cpu(enum cpu_led_event evt);
 374 #else
 375 static inline void ledtrig_cpu(enum cpu_led_event evt)
 376 {
 377         return;
 378 }
 379 #endif
 380
 381 #endif          /* __LINUX_LEDS_H_INCLUDED */