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/kernfs.h>
  17 #include <linux/list.h>
  18 #include <linux/mutex.h>
  19 #include <linux/rwsem.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/timer.h>
  22 #include <linux/workqueue.h>
  23
  24 struct device;
  25 /*
  26  * LED Core
  27  */
  28
  29 enum led_brightness {
  30         LED_OFF         = 0,
  31         LED_ON          = 1,
  32         LED_HALF        = 127,
  33         LED_FULL        = 255,
  34 };
  35
  36 struct led_classdev {
  37         const char              *name;
  38         enum led_brightness      brightness;
  39         enum led_brightness      max_brightness;
  40         int                      flags;
  41
  42         /* Lower 16 bits reflect status */
  43 #define LED_SUSPENDED           (1 << 0)
  44 #define LED_UNREGISTERING       (1 << 1)
  45         /* Upper 16 bits reflect control information */
  46 #define LED_CORE_SUSPENDRESUME  (1 << 16)
  47 #define LED_SYSFS_DISABLE       (1 << 17)
  48 #define LED_DEV_CAP_FLASH       (1 << 18)
  49 #define LED_HW_PLUGGABLE        (1 << 19)
  50 #define LED_PANIC_INDICATOR     (1 << 20)
  51 #define LED_BRIGHT_HW_CHANGED   (1 << 21)
  52
  53         /* set_brightness_work / blink_timer flags, atomic, private. */
  54         unsigned long           work_flags;
  55
  56 #define LED_BLINK_SW                    0
  57 #define LED_BLINK_ONESHOT               1
  58 #define LED_BLINK_ONESHOT_STOP          2
  59 #define LED_BLINK_INVERT                3
  60 #define LED_BLINK_BRIGHTNESS_CHANGE     4
  61 #define LED_BLINK_DISABLE               5
  62
  63         /* Set LED brightness level
  64          * Must not sleep. Use brightness_set_blocking for drivers
  65          * that can sleep while setting brightness.
  66          */
  67         void            (*brightness_set)(struct led_classdev *led_cdev,
  68                                           enum led_brightness brightness);
  69         /*
  70          * Set LED brightness level immediately - it can block the caller for
  71          * the time required for accessing a LED device register.
  72          */
  73         int (*brightness_set_blocking)(struct led_classdev *led_cdev,
  74                                        enum led_brightness brightness);
  75         /* Get LED brightness level */
  76         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  77
  78         /*
  79          * Activate hardware accelerated blink, delays are in milliseconds
  80          * and if both are zero then a sensible default should be chosen.
  81          * The call should adjust the timings in that case and if it can't
  82          * match the values specified exactly.
  83          * Deactivate blinking again when the brightness is set to LED_OFF
  84          * via the brightness_set() callback.
  85          */
  86         int             (*blink_set)(struct led_classdev *led_cdev,
  87                                      unsigned long *delay_on,
  88                                      unsigned long *delay_off);
  89
  90         struct device           *dev;
  91         const struct attribute_group    **groups;
  92
  93         struct list_head         node;                  /* LED Device list */
  94         const char              *default_trigger;       /* Trigger to use */
  95
  96         unsigned long            blink_delay_on, blink_delay_off;
  97         struct timer_list        blink_timer;
  98         int                      blink_brightness;
  99         int                      new_blink_brightness;
 100         void                    (*flash_resume)(struct led_classdev *led_cdev);
 101
 102         struct work_struct      set_brightness_work;
 103         int                     delayed_set_value;
 104
 105 #ifdef CONFIG_LEDS_TRIGGERS
 106         /* Protects the trigger data below */
 107         struct rw_semaphore      trigger_lock;
 108
 109         struct led_trigger      *trigger;
 110         struct list_head         trig_list;
 111         void                    *trigger_data;
 112         /* true if activated - deactivate routine uses it to do cleanup */
 113         bool                    activated;
 114 #endif
 115
 116 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 117         int                      brightness_hw_changed;
 118         struct kernfs_node      *brightness_hw_changed_kn;
 119 #endif
 120
 121         /* Ensures consistent access to the LED Flash Class device */
 122         struct mutex            led_access;
 123 };
 124
 125 extern int of_led_classdev_register(struct device *parent,
 126                                     struct device_node *np,
 127                                     struct led_classdev *led_cdev);
 128 #define led_classdev_register(parent, led_cdev)                         \
 129         of_led_classdev_register(parent, NULL, led_cdev)
 130 extern int devm_of_led_classdev_register(struct device *parent,
 131                                          struct device_node *np,
 132                                          struct led_classdev *led_cdev);
 133 #define devm_led_classdev_register(parent, led_cdev)                    \
 134         devm_of_led_classdev_register(parent, NULL, led_cdev)
 135 extern void led_classdev_unregister(struct led_classdev *led_cdev);
 136 extern void devm_led_classdev_unregister(struct device *parent,
 137                                          struct led_classdev *led_cdev);
 138 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 139 extern void led_classdev_resume(struct led_classdev *led_cdev);
 140
 141 /**
 142  * led_blink_set - set blinking with software fallback
 143  * @led_cdev: the LED to start blinking
 144  * @delay_on: the time it should be on (in ms)
 145  * @delay_off: the time it should ble off (in ms)
 146  *
 147  * This function makes the LED blink, attempting to use the
 148  * hardware acceleration if possible, but falling back to
 149  * software blinking if there is no hardware blinking or if
 150  * the LED refuses the passed values.
 151  *
 152  * Note that if software blinking is active, simply calling
 153  * led_cdev->brightness_set() will not stop the blinking,
 154  * use led_classdev_brightness_set() instead.
 155  */
 156 extern void led_blink_set(struct led_classdev *led_cdev,
 157                           unsigned long *delay_on,
 158                           unsigned long *delay_off);
 159 /**
 160  * led_blink_set_oneshot - do a oneshot software blink
 161  * @led_cdev: the LED to start blinking
 162  * @delay_on: the time it should be on (in ms)
 163  * @delay_off: the time it should ble off (in ms)
 164  * @invert: blink off, then on, leaving the led on
 165  *
 166  * This function makes the LED blink one time for delay_on +
 167  * delay_off time, ignoring the request if another one-shot
 168  * blink is already in progress.
 169  *
 170  * If invert is set, led blinks for delay_off first, then for
 171  * delay_on and leave the led on after the on-off cycle.
 172  */
 173 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 174                                   unsigned long *delay_on,
 175                                   unsigned long *delay_off,
 176                                   int invert);
 177 /**
 178  * led_set_brightness - set LED brightness
 179  * @led_cdev: the LED to set
 180  * @brightness: the brightness to set it to
 181  *
 182  * Set an LED's brightness, and, if necessary, cancel the
 183  * software blink timer that implements blinking when the
 184  * hardware doesn't. This function is guaranteed not to sleep.
 185  */
 186 extern void led_set_brightness(struct led_classdev *led_cdev,
 187                                enum led_brightness brightness);
 188
 189 /**
 190  * led_set_brightness_sync - set LED brightness synchronously
 191  * @led_cdev: the LED to set
 192  * @brightness: the brightness to set it to
 193  *
 194  * Set an LED's brightness immediately. This function will block
 195  * the caller for the time required for accessing device registers,
 196  * and it can sleep.
 197  *
 198  * Returns: 0 on success or negative error value on failure
 199  */
 200 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
 201                                    enum led_brightness value);
 202
 203 /**
 204  * led_update_brightness - update LED brightness
 205  * @led_cdev: the LED to query
 206  *
 207  * Get an LED's current brightness and update led_cdev->brightness
 208  * member with the obtained value.
 209  *
 210  * Returns: 0 on success or negative error value on failure
 211  */
 212 extern int led_update_brightness(struct led_classdev *led_cdev);
 213
 214 /**
 215  * led_sysfs_disable - disable LED sysfs interface
 216  * @led_cdev: the LED to set
 217  *
 218  * Disable the led_cdev's sysfs interface.
 219  */
 220 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 221
 222 /**
 223  * led_sysfs_enable - enable LED sysfs interface
 224  * @led_cdev: the LED to set
 225  *
 226  * Enable the led_cdev's sysfs interface.
 227  */
 228 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 229
 230 /**
 231  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 232  * @led_cdev: the LED to query
 233  *
 234  * Returns: true if the led_cdev's sysfs interface is disabled.
 235  */
 236 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 237 {
 238         return led_cdev->flags & LED_SYSFS_DISABLE;
 239 }
 240
 241 /*
 242  * LED Triggers
 243  */
 244 /* Registration functions for simple triggers */
 245 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 246 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 247
 248 #ifdef CONFIG_LEDS_TRIGGERS
 249
 250 #define TRIG_NAME_MAX 50
 251
 252 struct led_trigger {
 253         /* Trigger Properties */
 254         const char       *name;
 255         void            (*activate)(struct led_classdev *led_cdev);
 256         void            (*deactivate)(struct led_classdev *led_cdev);
 257
 258         /* LEDs under control by this trigger (for simple triggers) */
 259         rwlock_t          leddev_list_lock;
 260         struct list_head  led_cdevs;
 261
 262         /* Link to next registered trigger */
 263         struct list_head  next_trig;
 264 };
 265
 266 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 267                         const char *buf, size_t count);
 268 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 269                         char *buf);
 270
 271 /* Registration functions for complex triggers */
 272 extern int led_trigger_register(struct led_trigger *trigger);
 273 extern void led_trigger_unregister(struct led_trigger *trigger);
 274 extern int devm_led_trigger_register(struct device *dev,
 275                                      struct led_trigger *trigger);
 276
 277 extern void led_trigger_register_simple(const char *name,
 278                                 struct led_trigger **trigger);
 279 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 280 extern void led_trigger_event(struct led_trigger *trigger,
 281                                 enum led_brightness event);
 282 extern void led_trigger_blink(struct led_trigger *trigger,
 283                               unsigned long *delay_on,
 284                               unsigned long *delay_off);
 285 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 286                                       unsigned long *delay_on,
 287                                       unsigned long *delay_off,
 288                                       int invert);
 289 extern void led_trigger_set_default(struct led_classdev *led_cdev);
 290 extern void led_trigger_set(struct led_classdev *led_cdev,
 291                         struct led_trigger *trigger);
 292 extern void led_trigger_remove(struct led_classdev *led_cdev);
 293
 294 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 295 {
 296         return led_cdev->trigger_data;
 297 }
 298
 299 /**
 300  * led_trigger_rename_static - rename a trigger
 301  * @name: the new trigger name
 302  * @trig: the LED trigger to rename
 303  *
 304  * Change a LED trigger name by copying the string passed in
 305  * name into current trigger name, which MUST be large
 306  * enough for the new string.
 307  *
 308  * Note that name must NOT point to the same string used
 309  * during LED registration, as that could lead to races.
 310  *
 311  * This is meant to be used on triggers with statically
 312  * allocated name.
 313  */
 314 extern void led_trigger_rename_static(const char *name,
 315                                       struct led_trigger *trig);
 316
 317 #else
 318
 319 /* Trigger has no members */
 320 struct led_trigger {};
 321
 322 /* Trigger inline empty functions */
 323 static inline void led_trigger_register_simple(const char *name,
 324                                         struct led_trigger **trigger) {}
 325 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 326 static inline void led_trigger_event(struct led_trigger *trigger,
 327                                 enum led_brightness event) {}
 328 static inline void led_trigger_blink(struct led_trigger *trigger,
 329                                       unsigned long *delay_on,
 330                                       unsigned long *delay_off) {}
 331 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 332                                       unsigned long *delay_on,
 333                                       unsigned long *delay_off,
 334                                       int invert) {}
 335 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 336 static inline void led_trigger_set(struct led_classdev *led_cdev,
 337                                 struct led_trigger *trigger) {}
 338 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 339 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 340 {
 341         return NULL;
 342 }
 343
 344 #endif /* CONFIG_LEDS_TRIGGERS */
 345
 346 /* Trigger specific functions */
 347 #ifdef CONFIG_LEDS_TRIGGER_DISK
 348 extern void ledtrig_disk_activity(void);
 349 #else
 350 static inline void ledtrig_disk_activity(void) {}
 351 #endif
 352
 353 #ifdef CONFIG_LEDS_TRIGGER_MTD
 354 extern void ledtrig_mtd_activity(void);
 355 #else
 356 static inline void ledtrig_mtd_activity(void) {}
 357 #endif
 358
 359 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 360 extern void ledtrig_flash_ctrl(bool on);
 361 extern void ledtrig_torch_ctrl(bool on);
 362 #else
 363 static inline void ledtrig_flash_ctrl(bool on) {}
 364 static inline void ledtrig_torch_ctrl(bool on) {}
 365 #endif
 366
 367 /*
 368  * Generic LED platform data for describing LED names and default triggers.
 369  */
 370 struct led_info {
 371         const char      *name;
 372         const char      *default_trigger;
 373         int             flags;
 374 };
 375
 376 struct led_platform_data {
 377         int             num_leds;
 378         struct led_info *leds;
 379 };
 380
 381 struct gpio_desc;
 382 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 383                                 unsigned long *delay_on,
 384                                 unsigned long *delay_off);
 385
 386 /* For the leds-gpio driver */
 387 struct gpio_led {
 388         const char *name;
 389         const char *default_trigger;
 390         unsigned        gpio;
 391         unsigned        active_low : 1;
 392         unsigned        retain_state_suspended : 1;
 393         unsigned        panic_indicator : 1;
 394         unsigned        default_state : 2;
 395         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 396         struct gpio_desc *gpiod;
 397 };
 398 #define LEDS_GPIO_DEFSTATE_OFF          0
 399 #define LEDS_GPIO_DEFSTATE_ON           1
 400 #define LEDS_GPIO_DEFSTATE_KEEP         2
 401
 402 struct gpio_led_platform_data {
 403         int             num_leds;
 404         const struct gpio_led *leds;
 405
 406 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 407 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 408 #define GPIO_LED_BLINK          2       /* Please, blink */
 409         gpio_blink_set_t        gpio_blink_set;
 410 };
 411
 412 #ifdef CONFIG_NEW_LEDS
 413 struct platform_device *gpio_led_register_device(
 414                 int id, const struct gpio_led_platform_data *pdata);
 415 #else
 416 static inline struct platform_device *gpio_led_register_device(
 417                 int id, const struct gpio_led_platform_data *pdata)
 418 {
 419         return 0;
 420 }
 421 #endif
 422
 423 enum cpu_led_event {
 424         CPU_LED_IDLE_START,     /* CPU enters idle */
 425         CPU_LED_IDLE_END,       /* CPU idle ends */
 426         CPU_LED_START,          /* Machine starts, especially resume */
 427         CPU_LED_STOP,           /* Machine stops, especially suspend */
 428         CPU_LED_HALTED,         /* Machine shutdown */
 429 };
 430 #ifdef CONFIG_LEDS_TRIGGER_CPU
 431 extern void ledtrig_cpu(enum cpu_led_event evt);
 432 #else
 433 static inline void ledtrig_cpu(enum cpu_led_event evt)
 434 {
 435         return;
 436 }
 437 #endif
 438
 439 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 440 extern void led_classdev_notify_brightness_hw_changed(
 441         struct led_classdev *led_cdev, enum led_brightness brightness);
 442 #else
 443 static inline void led_classdev_notify_brightness_hw_changed(
 444         struct led_classdev *led_cdev, enum led_brightness brightness) { }
 445 #endif
 446
 447 #endif          /* __LINUX_LEDS_H_INCLUDED */