include/linux/leds.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Driver model for leds and led triggers
   4  *
   5  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
   6  * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
   7  */
   8 #ifndef __LINUX_LEDS_H_INCLUDED
   9 #define __LINUX_LEDS_H_INCLUDED
  10
  11 #include <linux/device.h>
  12 #include <linux/kernfs.h>
  13 #include <linux/list.h>
  14 #include <linux/mutex.h>
  15 #include <linux/rwsem.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/timer.h>
  18 #include <linux/workqueue.h>
  19
  20 struct device;
  21 struct led_pattern;
  22 /*
  23  * LED Core
  24  */
  25
  26 enum led_brightness {
  27         LED_OFF         = 0,
  28         LED_ON          = 1,
  29         LED_HALF        = 127,
  30         LED_FULL        = 255,
  31 };
  32
  33 struct led_classdev {
  34         const char              *name;
  35         enum led_brightness      brightness;
  36         enum led_brightness      max_brightness;
  37         int                      flags;
  38
  39         /* Lower 16 bits reflect status */
  40 #define LED_SUSPENDED           BIT(0)
  41 #define LED_UNREGISTERING       BIT(1)
  42         /* Upper 16 bits reflect control information */
  43 #define LED_CORE_SUSPENDRESUME  BIT(16)
  44 #define LED_SYSFS_DISABLE       BIT(17)
  45 #define LED_DEV_CAP_FLASH       BIT(18)
  46 #define LED_HW_PLUGGABLE        BIT(19)
  47 #define LED_PANIC_INDICATOR     BIT(20)
  48 #define LED_BRIGHT_HW_CHANGED   BIT(21)
  49 #define LED_RETAIN_AT_SHUTDOWN  BIT(22)
  50 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
  51
  52         /* set_brightness_work / blink_timer flags, atomic, private. */
  53         unsigned long           work_flags;
  54
  55 #define LED_BLINK_SW                    0
  56 #define LED_BLINK_ONESHOT               1
  57 #define LED_BLINK_ONESHOT_STOP          2
  58 #define LED_BLINK_INVERT                3
  59 #define LED_BLINK_BRIGHTNESS_CHANGE     4
  60 #define LED_BLINK_DISABLE               5
  61
  62         /* Set LED brightness level
  63          * Must not sleep. Use brightness_set_blocking for drivers
  64          * that can sleep while setting brightness.
  65          */
  66         void            (*brightness_set)(struct led_classdev *led_cdev,
  67                                           enum led_brightness brightness);
  68         /*
  69          * Set LED brightness level immediately - it can block the caller for
  70          * the time required for accessing a LED device register.
  71          */
  72         int (*brightness_set_blocking)(struct led_classdev *led_cdev,
  73                                        enum led_brightness brightness);
  74         /* Get LED brightness level */
  75         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  76
  77         /*
  78          * Activate hardware accelerated blink, delays are in milliseconds
  79          * and if both are zero then a sensible default should be chosen.
  80          * The call should adjust the timings in that case and if it can't
  81          * match the values specified exactly.
  82          * Deactivate blinking again when the brightness is set to LED_OFF
  83          * via the brightness_set() callback.
  84          */
  85         int             (*blink_set)(struct led_classdev *led_cdev,
  86                                      unsigned long *delay_on,
  87                                      unsigned long *delay_off);
  88
  89         int (*pattern_set)(struct led_classdev *led_cdev,
  90                            struct led_pattern *pattern, u32 len, int repeat);
  91         int (*pattern_clear)(struct led_classdev *led_cdev);
  92
  93         struct device           *dev;
  94         const struct attribute_group    **groups;
  95
  96         struct list_head         node;                  /* LED Device list */
  97         const char              *default_trigger;       /* Trigger to use */
  98
  99         unsigned long            blink_delay_on, blink_delay_off;
 100         struct timer_list        blink_timer;
 101         int                      blink_brightness;
 102         int                      new_blink_brightness;
 103         void                    (*flash_resume)(struct led_classdev *led_cdev);
 104
 105         struct work_struct      set_brightness_work;
 106         int                     delayed_set_value;
 107
 108 #ifdef CONFIG_LEDS_TRIGGERS
 109         /* Protects the trigger data below */
 110         struct rw_semaphore      trigger_lock;
 111
 112         struct led_trigger      *trigger;
 113         struct list_head         trig_list;
 114         void                    *trigger_data;
 115         /* true if activated - deactivate routine uses it to do cleanup */
 116         bool                    activated;
 117 #endif
 118
 119 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 120         int                      brightness_hw_changed;
 121         struct kernfs_node      *brightness_hw_changed_kn;
 122 #endif
 123
 124         /* Ensures consistent access to the LED Flash Class device */
 125         struct mutex            led_access;
 126 };
 127
 128 extern int of_led_classdev_register(struct device *parent,
 129                                     struct device_node *np,
 130                                     struct led_classdev *led_cdev);
 131 #define led_classdev_register(parent, led_cdev)                         \
 132         of_led_classdev_register(parent, NULL, led_cdev)
 133 extern int devm_of_led_classdev_register(struct device *parent,
 134                                          struct device_node *np,
 135                                          struct led_classdev *led_cdev);
 136 #define devm_led_classdev_register(parent, led_cdev)                    \
 137         devm_of_led_classdev_register(parent, NULL, led_cdev)
 138 extern void led_classdev_unregister(struct led_classdev *led_cdev);
 139 extern void devm_led_classdev_unregister(struct device *parent,
 140                                          struct led_classdev *led_cdev);
 141 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 142 extern void led_classdev_resume(struct led_classdev *led_cdev);
 143
 144 /**
 145  * led_blink_set - set blinking with software fallback
 146  * @led_cdev: the LED to start blinking
 147  * @delay_on: the time it should be on (in ms)
 148  * @delay_off: the time it should ble off (in ms)
 149  *
 150  * This function makes the LED blink, attempting to use the
 151  * hardware acceleration if possible, but falling back to
 152  * software blinking if there is no hardware blinking or if
 153  * the LED refuses the passed values.
 154  *
 155  * Note that if software blinking is active, simply calling
 156  * led_cdev->brightness_set() will not stop the blinking,
 157  * use led_classdev_brightness_set() instead.
 158  */
 159 extern void led_blink_set(struct led_classdev *led_cdev,
 160                           unsigned long *delay_on,
 161                           unsigned long *delay_off);
 162 /**
 163  * led_blink_set_oneshot - do a oneshot software blink
 164  * @led_cdev: the LED to start blinking
 165  * @delay_on: the time it should be on (in ms)
 166  * @delay_off: the time it should ble off (in ms)
 167  * @invert: blink off, then on, leaving the led on
 168  *
 169  * This function makes the LED blink one time for delay_on +
 170  * delay_off time, ignoring the request if another one-shot
 171  * blink is already in progress.
 172  *
 173  * If invert is set, led blinks for delay_off first, then for
 174  * delay_on and leave the led on after the on-off cycle.
 175  */
 176 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 177                                   unsigned long *delay_on,
 178                                   unsigned long *delay_off,
 179                                   int invert);
 180 /**
 181  * led_set_brightness - set LED brightness
 182  * @led_cdev: the LED to set
 183  * @brightness: the brightness to set it to
 184  *
 185  * Set an LED's brightness, and, if necessary, cancel the
 186  * software blink timer that implements blinking when the
 187  * hardware doesn't. This function is guaranteed not to sleep.
 188  */
 189 extern void led_set_brightness(struct led_classdev *led_cdev,
 190                                enum led_brightness brightness);
 191
 192 /**
 193  * led_set_brightness_sync - set LED brightness synchronously
 194  * @led_cdev: the LED to set
 195  * @brightness: the brightness to set it to
 196  *
 197  * Set an LED's brightness immediately. This function will block
 198  * the caller for the time required for accessing device registers,
 199  * and it can sleep.
 200  *
 201  * Returns: 0 on success or negative error value on failure
 202  */
 203 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
 204                                    enum led_brightness value);
 205
 206 /**
 207  * led_update_brightness - update LED brightness
 208  * @led_cdev: the LED to query
 209  *
 210  * Get an LED's current brightness and update led_cdev->brightness
 211  * member with the obtained value.
 212  *
 213  * Returns: 0 on success or negative error value on failure
 214  */
 215 extern int led_update_brightness(struct led_classdev *led_cdev);
 216
 217 /**
 218  * led_get_default_pattern - return default pattern
 219  *
 220  * @led_cdev: the LED to get default pattern for
 221  * @size:     pointer for storing the number of elements in returned array,
 222  *            modified only if return != NULL
 223  *
 224  * Return:    Allocated array of integers with default pattern from device tree
 225  *            or NULL.  Caller is responsible for kfree().
 226  */
 227 extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
 228                                     unsigned int *size);
 229
 230 /**
 231  * led_sysfs_disable - disable LED sysfs interface
 232  * @led_cdev: the LED to set
 233  *
 234  * Disable the led_cdev's sysfs interface.
 235  */
 236 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 237
 238 /**
 239  * led_sysfs_enable - enable LED sysfs interface
 240  * @led_cdev: the LED to set
 241  *
 242  * Enable the led_cdev's sysfs interface.
 243  */
 244 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 245
 246 /**
 247  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 248  * @led_cdev: the LED to query
 249  *
 250  * Returns: true if the led_cdev's sysfs interface is disabled.
 251  */
 252 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 253 {
 254         return led_cdev->flags & LED_SYSFS_DISABLE;
 255 }
 256
 257 /*
 258  * LED Triggers
 259  */
 260 /* Registration functions for simple triggers */
 261 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 262 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 263
 264 #ifdef CONFIG_LEDS_TRIGGERS
 265
 266 #define TRIG_NAME_MAX 50
 267
 268 struct led_trigger {
 269         /* Trigger Properties */
 270         const char       *name;
 271         int             (*activate)(struct led_classdev *led_cdev);
 272         void            (*deactivate)(struct led_classdev *led_cdev);
 273
 274         /* LEDs under control by this trigger (for simple triggers) */
 275         rwlock_t          leddev_list_lock;
 276         struct list_head  led_cdevs;
 277
 278         /* Link to next registered trigger */
 279         struct list_head  next_trig;
 280
 281         const struct attribute_group **groups;
 282 };
 283
 284 /*
 285  * Currently the attributes in struct led_trigger::groups are added directly to
 286  * the LED device. As this might change in the future, the following
 287  * macros abstract getting the LED device and its trigger_data from the dev
 288  * parameter passed to the attribute accessor functions.
 289  */
 290 #define led_trigger_get_led(dev)        ((struct led_classdev *)dev_get_drvdata((dev)))
 291 #define led_trigger_get_drvdata(dev)    (led_get_trigger_data(led_trigger_get_led(dev)))
 292
 293 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 294                         const char *buf, size_t count);
 295 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 296                         char *buf);
 297
 298 /* Registration functions for complex triggers */
 299 extern int led_trigger_register(struct led_trigger *trigger);
 300 extern void led_trigger_unregister(struct led_trigger *trigger);
 301 extern int devm_led_trigger_register(struct device *dev,
 302                                      struct led_trigger *trigger);
 303
 304 extern void led_trigger_register_simple(const char *name,
 305                                 struct led_trigger **trigger);
 306 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 307 extern void led_trigger_event(struct led_trigger *trigger,
 308                                 enum led_brightness event);
 309 extern void led_trigger_blink(struct led_trigger *trigger,
 310                               unsigned long *delay_on,
 311                               unsigned long *delay_off);
 312 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 313                                       unsigned long *delay_on,
 314                                       unsigned long *delay_off,
 315                                       int invert);
 316 extern void led_trigger_set_default(struct led_classdev *led_cdev);
 317 extern int led_trigger_set(struct led_classdev *led_cdev,
 318                            struct led_trigger *trigger);
 319 extern void led_trigger_remove(struct led_classdev *led_cdev);
 320
 321 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
 322                                         void *trigger_data)
 323 {
 324         led_cdev->trigger_data = trigger_data;
 325 }
 326
 327 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 328 {
 329         return led_cdev->trigger_data;
 330 }
 331
 332 /**
 333  * led_trigger_rename_static - rename a trigger
 334  * @name: the new trigger name
 335  * @trig: the LED trigger to rename
 336  *
 337  * Change a LED trigger name by copying the string passed in
 338  * name into current trigger name, which MUST be large
 339  * enough for the new string.
 340  *
 341  * Note that name must NOT point to the same string used
 342  * during LED registration, as that could lead to races.
 343  *
 344  * This is meant to be used on triggers with statically
 345  * allocated name.
 346  */
 347 extern void led_trigger_rename_static(const char *name,
 348                                       struct led_trigger *trig);
 349
 350 #define module_led_trigger(__led_trigger) \
 351         module_driver(__led_trigger, led_trigger_register, \
 352                       led_trigger_unregister)
 353
 354 #else
 355
 356 /* Trigger has no members */
 357 struct led_trigger {};
 358
 359 /* Trigger inline empty functions */
 360 static inline void led_trigger_register_simple(const char *name,
 361                                         struct led_trigger **trigger) {}
 362 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 363 static inline void led_trigger_event(struct led_trigger *trigger,
 364                                 enum led_brightness event) {}
 365 static inline void led_trigger_blink(struct led_trigger *trigger,
 366                                       unsigned long *delay_on,
 367                                       unsigned long *delay_off) {}
 368 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 369                                       unsigned long *delay_on,
 370                                       unsigned long *delay_off,
 371                                       int invert) {}
 372 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 373 static inline int led_trigger_set(struct led_classdev *led_cdev,
 374                                   struct led_trigger *trigger)
 375 {
 376         return 0;
 377 }
 378
 379 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 380 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
 381 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 382 {
 383         return NULL;
 384 }
 385
 386 #endif /* CONFIG_LEDS_TRIGGERS */
 387
 388 /* Trigger specific functions */
 389 #ifdef CONFIG_LEDS_TRIGGER_DISK
 390 extern void ledtrig_disk_activity(bool write);
 391 #else
 392 static inline void ledtrig_disk_activity(bool write) {}
 393 #endif
 394
 395 #ifdef CONFIG_LEDS_TRIGGER_MTD
 396 extern void ledtrig_mtd_activity(void);
 397 #else
 398 static inline void ledtrig_mtd_activity(void) {}
 399 #endif
 400
 401 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 402 extern void ledtrig_flash_ctrl(bool on);
 403 extern void ledtrig_torch_ctrl(bool on);
 404 #else
 405 static inline void ledtrig_flash_ctrl(bool on) {}
 406 static inline void ledtrig_torch_ctrl(bool on) {}
 407 #endif
 408
 409 /*
 410  * Generic LED platform data for describing LED names and default triggers.
 411  */
 412 struct led_info {
 413         const char      *name;
 414         const char      *default_trigger;
 415         int             flags;
 416 };
 417
 418 struct led_platform_data {
 419         int             num_leds;
 420         struct led_info *leds;
 421 };
 422
 423 struct gpio_desc;
 424 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 425                                 unsigned long *delay_on,
 426                                 unsigned long *delay_off);
 427
 428 /* For the leds-gpio driver */
 429 struct gpio_led {
 430         const char *name;
 431         const char *default_trigger;
 432         unsigned        gpio;
 433         unsigned        active_low : 1;
 434         unsigned        retain_state_suspended : 1;
 435         unsigned        panic_indicator : 1;
 436         unsigned        default_state : 2;
 437         unsigned        retain_state_shutdown : 1;
 438         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 439         struct gpio_desc *gpiod;
 440 };
 441 #define LEDS_GPIO_DEFSTATE_OFF          0
 442 #define LEDS_GPIO_DEFSTATE_ON           1
 443 #define LEDS_GPIO_DEFSTATE_KEEP         2
 444
 445 struct gpio_led_platform_data {
 446         int             num_leds;
 447         const struct gpio_led *leds;
 448
 449 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 450 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 451 #define GPIO_LED_BLINK          2       /* Please, blink */
 452         gpio_blink_set_t        gpio_blink_set;
 453 };
 454
 455 #ifdef CONFIG_NEW_LEDS
 456 struct platform_device *gpio_led_register_device(
 457                 int id, const struct gpio_led_platform_data *pdata);
 458 #else
 459 static inline struct platform_device *gpio_led_register_device(
 460                 int id, const struct gpio_led_platform_data *pdata)
 461 {
 462         return 0;
 463 }
 464 #endif
 465
 466 enum cpu_led_event {
 467         CPU_LED_IDLE_START,     /* CPU enters idle */
 468         CPU_LED_IDLE_END,       /* CPU idle ends */
 469         CPU_LED_START,          /* Machine starts, especially resume */
 470         CPU_LED_STOP,           /* Machine stops, especially suspend */
 471         CPU_LED_HALTED,         /* Machine shutdown */
 472 };
 473 #ifdef CONFIG_LEDS_TRIGGER_CPU
 474 extern void ledtrig_cpu(enum cpu_led_event evt);
 475 #else
 476 static inline void ledtrig_cpu(enum cpu_led_event evt)
 477 {
 478         return;
 479 }
 480 #endif
 481
 482 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 483 extern void led_classdev_notify_brightness_hw_changed(
 484         struct led_classdev *led_cdev, enum led_brightness brightness);
 485 #else
 486 static inline void led_classdev_notify_brightness_hw_changed(
 487         struct led_classdev *led_cdev, enum led_brightness brightness) { }
 488 #endif
 489
 490 /**
 491  * struct led_pattern - pattern interval settings
 492  * @delta_t: pattern interval delay, in milliseconds
 493  * @brightness: pattern interval brightness
 494  */
 495 struct led_pattern {
 496         u32 delta_t;
 497         int brightness;
 498 };
 499
 500 enum led_audio {
 501         LED_AUDIO_MUTE,         /* master mute LED */
 502         LED_AUDIO_MICMUTE,      /* mic mute LED */
 503         NUM_AUDIO_LEDS
 504 };
 505
 506 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
 507 enum led_brightness ledtrig_audio_get(enum led_audio type);
 508 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
 509 #else
 510 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
 511 {
 512         return LED_OFF;
 513 }
 514 static inline void ledtrig_audio_set(enum led_audio type,
 515                                      enum led_brightness state)
 516 {
 517 }
 518 #endif
 519
 520 #endif          /* __LINUX_LEDS_H_INCLUDED */