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 struct led_pattern;
  26 /*
  27  * LED Core
  28  */
  29
  30 enum led_brightness {
  31         LED_OFF         = 0,
  32         LED_ON          = 1,
  33         LED_HALF        = 127,
  34         LED_FULL        = 255,
  35 };
  36
  37 struct led_classdev {
  38         const char              *name;
  39         enum led_brightness      brightness;
  40         enum led_brightness      max_brightness;
  41         int                      flags;
  42
  43         /* Lower 16 bits reflect status */
  44 #define LED_SUSPENDED           BIT(0)
  45 #define LED_UNREGISTERING       BIT(1)
  46         /* Upper 16 bits reflect control information */
  47 #define LED_CORE_SUSPENDRESUME  BIT(16)
  48 #define LED_SYSFS_DISABLE       BIT(17)
  49 #define LED_DEV_CAP_FLASH       BIT(18)
  50 #define LED_HW_PLUGGABLE        BIT(19)
  51 #define LED_PANIC_INDICATOR     BIT(20)
  52 #define LED_BRIGHT_HW_CHANGED   BIT(21)
  53 #define LED_RETAIN_AT_SHUTDOWN  BIT(22)
  54 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
  55
  56         /* set_brightness_work / blink_timer flags, atomic, private. */
  57         unsigned long           work_flags;
  58
  59 #define LED_BLINK_SW                    0
  60 #define LED_BLINK_ONESHOT               1
  61 #define LED_BLINK_ONESHOT_STOP          2
  62 #define LED_BLINK_INVERT                3
  63 #define LED_BLINK_BRIGHTNESS_CHANGE     4
  64 #define LED_BLINK_DISABLE               5
  65
  66         /* Set LED brightness level
  67          * Must not sleep. Use brightness_set_blocking for drivers
  68          * that can sleep while setting brightness.
  69          */
  70         void            (*brightness_set)(struct led_classdev *led_cdev,
  71                                           enum led_brightness brightness);
  72         /*
  73          * Set LED brightness level immediately - it can block the caller for
  74          * the time required for accessing a LED device register.
  75          */
  76         int (*brightness_set_blocking)(struct led_classdev *led_cdev,
  77                                        enum led_brightness brightness);
  78         /* Get LED brightness level */
  79         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  80
  81         /*
  82          * Activate hardware accelerated blink, delays are in milliseconds
  83          * and if both are zero then a sensible default should be chosen.
  84          * The call should adjust the timings in that case and if it can't
  85          * match the values specified exactly.
  86          * Deactivate blinking again when the brightness is set to LED_OFF
  87          * via the brightness_set() callback.
  88          */
  89         int             (*blink_set)(struct led_classdev *led_cdev,
  90                                      unsigned long *delay_on,
  91                                      unsigned long *delay_off);
  92
  93         int (*pattern_set)(struct led_classdev *led_cdev,
  94                            struct led_pattern *pattern, u32 len, int repeat);
  95         int (*pattern_clear)(struct led_classdev *led_cdev);
  96
  97         struct device           *dev;
  98         const struct attribute_group    **groups;
  99
 100         struct list_head         node;                  /* LED Device list */
 101         const char              *default_trigger;       /* Trigger to use */
 102
 103         unsigned long            blink_delay_on, blink_delay_off;
 104         struct timer_list        blink_timer;
 105         int                      blink_brightness;
 106         int                      new_blink_brightness;
 107         void                    (*flash_resume)(struct led_classdev *led_cdev);
 108
 109         struct work_struct      set_brightness_work;
 110         int                     delayed_set_value;
 111
 112 #ifdef CONFIG_LEDS_TRIGGERS
 113         /* Protects the trigger data below */
 114         struct rw_semaphore      trigger_lock;
 115
 116         struct led_trigger      *trigger;
 117         struct list_head         trig_list;
 118         void                    *trigger_data;
 119         /* true if activated - deactivate routine uses it to do cleanup */
 120         bool                    activated;
 121 #endif
 122
 123 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 124         int                      brightness_hw_changed;
 125         struct kernfs_node      *brightness_hw_changed_kn;
 126 #endif
 127
 128         /* Ensures consistent access to the LED Flash Class device */
 129         struct mutex            led_access;
 130 };
 131
 132 extern int of_led_classdev_register(struct device *parent,
 133                                     struct device_node *np,
 134                                     struct led_classdev *led_cdev);
 135 #define led_classdev_register(parent, led_cdev)                         \
 136         of_led_classdev_register(parent, NULL, led_cdev)
 137 extern int devm_of_led_classdev_register(struct device *parent,
 138                                          struct device_node *np,
 139                                          struct led_classdev *led_cdev);
 140 #define devm_led_classdev_register(parent, led_cdev)                    \
 141         devm_of_led_classdev_register(parent, NULL, led_cdev)
 142 extern void led_classdev_unregister(struct led_classdev *led_cdev);
 143 extern void devm_led_classdev_unregister(struct device *parent,
 144                                          struct led_classdev *led_cdev);
 145 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 146 extern void led_classdev_resume(struct led_classdev *led_cdev);
 147
 148 /**
 149  * led_blink_set - set blinking with software fallback
 150  * @led_cdev: the LED to start blinking
 151  * @delay_on: the time it should be on (in ms)
 152  * @delay_off: the time it should ble off (in ms)
 153  *
 154  * This function makes the LED blink, attempting to use the
 155  * hardware acceleration if possible, but falling back to
 156  * software blinking if there is no hardware blinking or if
 157  * the LED refuses the passed values.
 158  *
 159  * Note that if software blinking is active, simply calling
 160  * led_cdev->brightness_set() will not stop the blinking,
 161  * use led_classdev_brightness_set() instead.
 162  */
 163 extern void led_blink_set(struct led_classdev *led_cdev,
 164                           unsigned long *delay_on,
 165                           unsigned long *delay_off);
 166 /**
 167  * led_blink_set_oneshot - do a oneshot software blink
 168  * @led_cdev: the LED to start blinking
 169  * @delay_on: the time it should be on (in ms)
 170  * @delay_off: the time it should ble off (in ms)
 171  * @invert: blink off, then on, leaving the led on
 172  *
 173  * This function makes the LED blink one time for delay_on +
 174  * delay_off time, ignoring the request if another one-shot
 175  * blink is already in progress.
 176  *
 177  * If invert is set, led blinks for delay_off first, then for
 178  * delay_on and leave the led on after the on-off cycle.
 179  */
 180 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 181                                   unsigned long *delay_on,
 182                                   unsigned long *delay_off,
 183                                   int invert);
 184 /**
 185  * led_set_brightness - set LED brightness
 186  * @led_cdev: the LED to set
 187  * @brightness: the brightness to set it to
 188  *
 189  * Set an LED's brightness, and, if necessary, cancel the
 190  * software blink timer that implements blinking when the
 191  * hardware doesn't. This function is guaranteed not to sleep.
 192  */
 193 extern void led_set_brightness(struct led_classdev *led_cdev,
 194                                enum led_brightness brightness);
 195
 196 /**
 197  * led_set_brightness_sync - set LED brightness synchronously
 198  * @led_cdev: the LED to set
 199  * @brightness: the brightness to set it to
 200  *
 201  * Set an LED's brightness immediately. This function will block
 202  * the caller for the time required for accessing device registers,
 203  * and it can sleep.
 204  *
 205  * Returns: 0 on success or negative error value on failure
 206  */
 207 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
 208                                    enum led_brightness value);
 209
 210 /**
 211  * led_update_brightness - update LED brightness
 212  * @led_cdev: the LED to query
 213  *
 214  * Get an LED's current brightness and update led_cdev->brightness
 215  * member with the obtained value.
 216  *
 217  * Returns: 0 on success or negative error value on failure
 218  */
 219 extern int led_update_brightness(struct led_classdev *led_cdev);
 220
 221 /**
 222  * led_get_default_pattern - return default pattern
 223  *
 224  * @led_cdev: the LED to get default pattern for
 225  * @size:     pointer for storing the number of elements in returned array,
 226  *            modified only if return != NULL
 227  *
 228  * Return:    Allocated array of integers with default pattern from device tree
 229  *            or NULL.  Caller is responsible for kfree().
 230  */
 231 extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
 232                                     unsigned int *size);
 233
 234 /**
 235  * led_sysfs_disable - disable LED sysfs interface
 236  * @led_cdev: the LED to set
 237  *
 238  * Disable the led_cdev's sysfs interface.
 239  */
 240 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 241
 242 /**
 243  * led_sysfs_enable - enable LED sysfs interface
 244  * @led_cdev: the LED to set
 245  *
 246  * Enable the led_cdev's sysfs interface.
 247  */
 248 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 249
 250 /**
 251  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 252  * @led_cdev: the LED to query
 253  *
 254  * Returns: true if the led_cdev's sysfs interface is disabled.
 255  */
 256 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 257 {
 258         return led_cdev->flags & LED_SYSFS_DISABLE;
 259 }
 260
 261 /*
 262  * LED Triggers
 263  */
 264 /* Registration functions for simple triggers */
 265 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 266 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 267
 268 #ifdef CONFIG_LEDS_TRIGGERS
 269
 270 #define TRIG_NAME_MAX 50
 271
 272 struct led_trigger {
 273         /* Trigger Properties */
 274         const char       *name;
 275         int             (*activate)(struct led_classdev *led_cdev);
 276         void            (*deactivate)(struct led_classdev *led_cdev);
 277
 278         /* LEDs under control by this trigger (for simple triggers) */
 279         rwlock_t          leddev_list_lock;
 280         struct list_head  led_cdevs;
 281
 282         /* Link to next registered trigger */
 283         struct list_head  next_trig;
 284
 285         const struct attribute_group **groups;
 286 };
 287
 288 /*
 289  * Currently the attributes in struct led_trigger::groups are added directly to
 290  * the LED device. As this might change in the future, the following
 291  * macros abstract getting the LED device and its trigger_data from the dev
 292  * parameter passed to the attribute accessor functions.
 293  */
 294 #define led_trigger_get_led(dev)        ((struct led_classdev *)dev_get_drvdata((dev)))
 295 #define led_trigger_get_drvdata(dev)    (led_get_trigger_data(led_trigger_get_led(dev)))
 296
 297 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 298                         const char *buf, size_t count);
 299 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 300                         char *buf);
 301
 302 /* Registration functions for complex triggers */
 303 extern int led_trigger_register(struct led_trigger *trigger);
 304 extern void led_trigger_unregister(struct led_trigger *trigger);
 305 extern int devm_led_trigger_register(struct device *dev,
 306                                      struct led_trigger *trigger);
 307
 308 extern void led_trigger_register_simple(const char *name,
 309                                 struct led_trigger **trigger);
 310 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 311 extern void led_trigger_event(struct led_trigger *trigger,
 312                                 enum led_brightness event);
 313 extern void led_trigger_blink(struct led_trigger *trigger,
 314                               unsigned long *delay_on,
 315                               unsigned long *delay_off);
 316 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 317                                       unsigned long *delay_on,
 318                                       unsigned long *delay_off,
 319                                       int invert);
 320 extern void led_trigger_set_default(struct led_classdev *led_cdev);
 321 extern int led_trigger_set(struct led_classdev *led_cdev,
 322                            struct led_trigger *trigger);
 323 extern void led_trigger_remove(struct led_classdev *led_cdev);
 324
 325 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
 326                                         void *trigger_data)
 327 {
 328         led_cdev->trigger_data = trigger_data;
 329 }
 330
 331 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 332 {
 333         return led_cdev->trigger_data;
 334 }
 335
 336 /**
 337  * led_trigger_rename_static - rename a trigger
 338  * @name: the new trigger name
 339  * @trig: the LED trigger to rename
 340  *
 341  * Change a LED trigger name by copying the string passed in
 342  * name into current trigger name, which MUST be large
 343  * enough for the new string.
 344  *
 345  * Note that name must NOT point to the same string used
 346  * during LED registration, as that could lead to races.
 347  *
 348  * This is meant to be used on triggers with statically
 349  * allocated name.
 350  */
 351 extern void led_trigger_rename_static(const char *name,
 352                                       struct led_trigger *trig);
 353
 354 #define module_led_trigger(__led_trigger) \
 355         module_driver(__led_trigger, led_trigger_register, \
 356                       led_trigger_unregister)
 357
 358 #else
 359
 360 /* Trigger has no members */
 361 struct led_trigger {};
 362
 363 /* Trigger inline empty functions */
 364 static inline void led_trigger_register_simple(const char *name,
 365                                         struct led_trigger **trigger) {}
 366 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 367 static inline void led_trigger_event(struct led_trigger *trigger,
 368                                 enum led_brightness event) {}
 369 static inline void led_trigger_blink(struct led_trigger *trigger,
 370                                       unsigned long *delay_on,
 371                                       unsigned long *delay_off) {}
 372 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 373                                       unsigned long *delay_on,
 374                                       unsigned long *delay_off,
 375                                       int invert) {}
 376 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 377 static inline int led_trigger_set(struct led_classdev *led_cdev,
 378                                   struct led_trigger *trigger)
 379 {
 380         return 0;
 381 }
 382
 383 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 384 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
 385 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 386 {
 387         return NULL;
 388 }
 389
 390 #endif /* CONFIG_LEDS_TRIGGERS */
 391
 392 /* Trigger specific functions */
 393 #ifdef CONFIG_LEDS_TRIGGER_DISK
 394 extern void ledtrig_disk_activity(bool write);
 395 #else
 396 static inline void ledtrig_disk_activity(bool write) {}
 397 #endif
 398
 399 #ifdef CONFIG_LEDS_TRIGGER_MTD
 400 extern void ledtrig_mtd_activity(void);
 401 #else
 402 static inline void ledtrig_mtd_activity(void) {}
 403 #endif
 404
 405 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 406 extern void ledtrig_flash_ctrl(bool on);
 407 extern void ledtrig_torch_ctrl(bool on);
 408 #else
 409 static inline void ledtrig_flash_ctrl(bool on) {}
 410 static inline void ledtrig_torch_ctrl(bool on) {}
 411 #endif
 412
 413 /*
 414  * Generic LED platform data for describing LED names and default triggers.
 415  */
 416 struct led_info {
 417         const char      *name;
 418         const char      *default_trigger;
 419         int             flags;
 420 };
 421
 422 struct led_platform_data {
 423         int             num_leds;
 424         struct led_info *leds;
 425 };
 426
 427 struct gpio_desc;
 428 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 429                                 unsigned long *delay_on,
 430                                 unsigned long *delay_off);
 431
 432 /* For the leds-gpio driver */
 433 struct gpio_led {
 434         const char *name;
 435         const char *default_trigger;
 436         unsigned        gpio;
 437         unsigned        active_low : 1;
 438         unsigned        retain_state_suspended : 1;
 439         unsigned        panic_indicator : 1;
 440         unsigned        default_state : 2;
 441         unsigned        retain_state_shutdown : 1;
 442         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 443         struct gpio_desc *gpiod;
 444 };
 445 #define LEDS_GPIO_DEFSTATE_OFF          0
 446 #define LEDS_GPIO_DEFSTATE_ON           1
 447 #define LEDS_GPIO_DEFSTATE_KEEP         2
 448
 449 struct gpio_led_platform_data {
 450         int             num_leds;
 451         const struct gpio_led *leds;
 452
 453 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 454 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 455 #define GPIO_LED_BLINK          2       /* Please, blink */
 456         gpio_blink_set_t        gpio_blink_set;
 457 };
 458
 459 #ifdef CONFIG_NEW_LEDS
 460 struct platform_device *gpio_led_register_device(
 461                 int id, const struct gpio_led_platform_data *pdata);
 462 #else
 463 static inline struct platform_device *gpio_led_register_device(
 464                 int id, const struct gpio_led_platform_data *pdata)
 465 {
 466         return 0;
 467 }
 468 #endif
 469
 470 enum cpu_led_event {
 471         CPU_LED_IDLE_START,     /* CPU enters idle */
 472         CPU_LED_IDLE_END,       /* CPU idle ends */
 473         CPU_LED_START,          /* Machine starts, especially resume */
 474         CPU_LED_STOP,           /* Machine stops, especially suspend */
 475         CPU_LED_HALTED,         /* Machine shutdown */
 476 };
 477 #ifdef CONFIG_LEDS_TRIGGER_CPU
 478 extern void ledtrig_cpu(enum cpu_led_event evt);
 479 #else
 480 static inline void ledtrig_cpu(enum cpu_led_event evt)
 481 {
 482         return;
 483 }
 484 #endif
 485
 486 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 487 extern void led_classdev_notify_brightness_hw_changed(
 488         struct led_classdev *led_cdev, enum led_brightness brightness);
 489 #else
 490 static inline void led_classdev_notify_brightness_hw_changed(
 491         struct led_classdev *led_cdev, enum led_brightness brightness) { }
 492 #endif
 493
 494 /**
 495  * struct led_pattern - pattern interval settings
 496  * @delta_t: pattern interval delay, in milliseconds
 497  * @brightness: pattern interval brightness
 498  */
 499 struct led_pattern {
 500         u32 delta_t;
 501         int brightness;
 502 };
 503
 504 enum led_audio {
 505         LED_AUDIO_MUTE,         /* master mute LED */
 506         LED_AUDIO_MICMUTE,      /* mic mute LED */
 507         NUM_AUDIO_LEDS
 508 };
 509
 510 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
 511 enum led_brightness ledtrig_audio_get(enum led_audio type);
 512 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
 513 #else
 514 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
 515 {
 516         return LED_OFF;
 517 }
 518 static inline void ledtrig_audio_set(enum led_audio type,
 519                                      enum led_brightness state)
 520 {
 521 }
 522 #endif
 523
 524 #endif          /* __LINUX_LEDS_H_INCLUDED */