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_init_data {
  34         /* device fwnode handle */
  35         struct fwnode_handle *fwnode;
  36 };
  37
  38 struct led_classdev {
  39         const char              *name;
  40         enum led_brightness      brightness;
  41         enum led_brightness      max_brightness;
  42         int                      flags;
  43
  44         /* Lower 16 bits reflect status */
  45 #define LED_SUSPENDED           BIT(0)
  46 #define LED_UNREGISTERING       BIT(1)
  47         /* Upper 16 bits reflect control information */
  48 #define LED_CORE_SUSPENDRESUME  BIT(16)
  49 #define LED_SYSFS_DISABLE       BIT(17)
  50 #define LED_DEV_CAP_FLASH       BIT(18)
  51 #define LED_HW_PLUGGABLE        BIT(19)
  52 #define LED_PANIC_INDICATOR     BIT(20)
  53 #define LED_BRIGHT_HW_CHANGED   BIT(21)
  54 #define LED_RETAIN_AT_SHUTDOWN  BIT(22)
  55 #define LED_INIT_DEFAULT_TRIGGER BIT(23)
  56
  57         /* set_brightness_work / blink_timer flags, atomic, private. */
  58         unsigned long           work_flags;
  59
  60 #define LED_BLINK_SW                    0
  61 #define LED_BLINK_ONESHOT               1
  62 #define LED_BLINK_ONESHOT_STOP          2
  63 #define LED_BLINK_INVERT                3
  64 #define LED_BLINK_BRIGHTNESS_CHANGE     4
  65 #define LED_BLINK_DISABLE               5
  66
  67         /* Set LED brightness level
  68          * Must not sleep. Use brightness_set_blocking for drivers
  69          * that can sleep while setting brightness.
  70          */
  71         void            (*brightness_set)(struct led_classdev *led_cdev,
  72                                           enum led_brightness brightness);
  73         /*
  74          * Set LED brightness level immediately - it can block the caller for
  75          * the time required for accessing a LED device register.
  76          */
  77         int (*brightness_set_blocking)(struct led_classdev *led_cdev,
  78                                        enum led_brightness brightness);
  79         /* Get LED brightness level */
  80         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  81
  82         /*
  83          * Activate hardware accelerated blink, delays are in milliseconds
  84          * and if both are zero then a sensible default should be chosen.
  85          * The call should adjust the timings in that case and if it can't
  86          * match the values specified exactly.
  87          * Deactivate blinking again when the brightness is set to LED_OFF
  88          * via the brightness_set() callback.
  89          */
  90         int             (*blink_set)(struct led_classdev *led_cdev,
  91                                      unsigned long *delay_on,
  92                                      unsigned long *delay_off);
  93
  94         int (*pattern_set)(struct led_classdev *led_cdev,
  95                            struct led_pattern *pattern, u32 len, int repeat);
  96         int (*pattern_clear)(struct led_classdev *led_cdev);
  97
  98         struct device           *dev;
  99         const struct attribute_group    **groups;
 100
 101         struct list_head         node;                  /* LED Device list */
 102         const char              *default_trigger;       /* Trigger to use */
 103
 104         unsigned long            blink_delay_on, blink_delay_off;
 105         struct timer_list        blink_timer;
 106         int                      blink_brightness;
 107         int                      new_blink_brightness;
 108         void                    (*flash_resume)(struct led_classdev *led_cdev);
 109
 110         struct work_struct      set_brightness_work;
 111         int                     delayed_set_value;
 112
 113 #ifdef CONFIG_LEDS_TRIGGERS
 114         /* Protects the trigger data below */
 115         struct rw_semaphore      trigger_lock;
 116
 117         struct led_trigger      *trigger;
 118         struct list_head         trig_list;
 119         void                    *trigger_data;
 120         /* true if activated - deactivate routine uses it to do cleanup */
 121         bool                    activated;
 122 #endif
 123
 124 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 125         int                      brightness_hw_changed;
 126         struct kernfs_node      *brightness_hw_changed_kn;
 127 #endif
 128
 129         /* Ensures consistent access to the LED Flash Class device */
 130         struct mutex            led_access;
 131 };
 132
 133 /**
 134  * led_classdev_register_ext - register a new object of LED class with
 135  *                             init data
 136  * @parent: LED controller device this LED is driven by
 137  * @led_cdev: the led_classdev structure for this device
 138  * @init_data: the LED class device initialization data
 139  *
 140  * Returns: 0 on success or negative error value on failure
 141  */
 142 extern int led_classdev_register_ext(struct device *parent,
 143                                      struct led_classdev *led_cdev,
 144                                      struct led_init_data *init_data);
 145 #define led_classdev_register(parent, led_cdev)                 \
 146         led_classdev_register_ext(parent, led_cdev, NULL)
 147 extern int devm_led_classdev_register_ext(struct device *parent,
 148                                           struct led_classdev *led_cdev,
 149                                           struct led_init_data *init_data);
 150 #define devm_led_classdev_register(parent, led_cdev)            \
 151         devm_led_classdev_register_ext(parent, led_cdev, NULL)
 152 extern void led_classdev_unregister(struct led_classdev *led_cdev);
 153 extern void devm_led_classdev_unregister(struct device *parent,
 154                                          struct led_classdev *led_cdev);
 155 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 156 extern void led_classdev_resume(struct led_classdev *led_cdev);
 157
 158 /**
 159  * led_blink_set - set blinking with software fallback
 160  * @led_cdev: the LED to start blinking
 161  * @delay_on: the time it should be on (in ms)
 162  * @delay_off: the time it should ble off (in ms)
 163  *
 164  * This function makes the LED blink, attempting to use the
 165  * hardware acceleration if possible, but falling back to
 166  * software blinking if there is no hardware blinking or if
 167  * the LED refuses the passed values.
 168  *
 169  * Note that if software blinking is active, simply calling
 170  * led_cdev->brightness_set() will not stop the blinking,
 171  * use led_classdev_brightness_set() instead.
 172  */
 173 extern void led_blink_set(struct led_classdev *led_cdev,
 174                           unsigned long *delay_on,
 175                           unsigned long *delay_off);
 176 /**
 177  * led_blink_set_oneshot - do a oneshot software blink
 178  * @led_cdev: the LED to start blinking
 179  * @delay_on: the time it should be on (in ms)
 180  * @delay_off: the time it should ble off (in ms)
 181  * @invert: blink off, then on, leaving the led on
 182  *
 183  * This function makes the LED blink one time for delay_on +
 184  * delay_off time, ignoring the request if another one-shot
 185  * blink is already in progress.
 186  *
 187  * If invert is set, led blinks for delay_off first, then for
 188  * delay_on and leave the led on after the on-off cycle.
 189  */
 190 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 191                                   unsigned long *delay_on,
 192                                   unsigned long *delay_off,
 193                                   int invert);
 194 /**
 195  * led_set_brightness - set LED brightness
 196  * @led_cdev: the LED to set
 197  * @brightness: the brightness to set it to
 198  *
 199  * Set an LED's brightness, and, if necessary, cancel the
 200  * software blink timer that implements blinking when the
 201  * hardware doesn't. This function is guaranteed not to sleep.
 202  */
 203 extern void led_set_brightness(struct led_classdev *led_cdev,
 204                                enum led_brightness brightness);
 205
 206 /**
 207  * led_set_brightness_sync - set LED brightness synchronously
 208  * @led_cdev: the LED to set
 209  * @brightness: the brightness to set it to
 210  *
 211  * Set an LED's brightness immediately. This function will block
 212  * the caller for the time required for accessing device registers,
 213  * and it can sleep.
 214  *
 215  * Returns: 0 on success or negative error value on failure
 216  */
 217 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
 218                                    enum led_brightness value);
 219
 220 /**
 221  * led_update_brightness - update LED brightness
 222  * @led_cdev: the LED to query
 223  *
 224  * Get an LED's current brightness and update led_cdev->brightness
 225  * member with the obtained value.
 226  *
 227  * Returns: 0 on success or negative error value on failure
 228  */
 229 extern int led_update_brightness(struct led_classdev *led_cdev);
 230
 231 /**
 232  * led_get_default_pattern - return default pattern
 233  *
 234  * @led_cdev: the LED to get default pattern for
 235  * @size:     pointer for storing the number of elements in returned array,
 236  *            modified only if return != NULL
 237  *
 238  * Return:    Allocated array of integers with default pattern from device tree
 239  *            or NULL.  Caller is responsible for kfree().
 240  */
 241 extern u32 *led_get_default_pattern(struct led_classdev *led_cdev,
 242                                     unsigned int *size);
 243
 244 /**
 245  * led_sysfs_disable - disable LED sysfs interface
 246  * @led_cdev: the LED to set
 247  *
 248  * Disable the led_cdev's sysfs interface.
 249  */
 250 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 251
 252 /**
 253  * led_sysfs_enable - enable LED sysfs interface
 254  * @led_cdev: the LED to set
 255  *
 256  * Enable the led_cdev's sysfs interface.
 257  */
 258 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 259
 260 /**
 261  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 262  * @led_cdev: the LED to query
 263  *
 264  * Returns: true if the led_cdev's sysfs interface is disabled.
 265  */
 266 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 267 {
 268         return led_cdev->flags & LED_SYSFS_DISABLE;
 269 }
 270
 271 /*
 272  * LED Triggers
 273  */
 274 /* Registration functions for simple triggers */
 275 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 276 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 277
 278 #ifdef CONFIG_LEDS_TRIGGERS
 279
 280 #define TRIG_NAME_MAX 50
 281
 282 struct led_trigger {
 283         /* Trigger Properties */
 284         const char       *name;
 285         int             (*activate)(struct led_classdev *led_cdev);
 286         void            (*deactivate)(struct led_classdev *led_cdev);
 287
 288         /* LEDs under control by this trigger (for simple triggers) */
 289         rwlock_t          leddev_list_lock;
 290         struct list_head  led_cdevs;
 291
 292         /* Link to next registered trigger */
 293         struct list_head  next_trig;
 294
 295         const struct attribute_group **groups;
 296 };
 297
 298 /*
 299  * Currently the attributes in struct led_trigger::groups are added directly to
 300  * the LED device. As this might change in the future, the following
 301  * macros abstract getting the LED device and its trigger_data from the dev
 302  * parameter passed to the attribute accessor functions.
 303  */
 304 #define led_trigger_get_led(dev)        ((struct led_classdev *)dev_get_drvdata((dev)))
 305 #define led_trigger_get_drvdata(dev)    (led_get_trigger_data(led_trigger_get_led(dev)))
 306
 307 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 308                         const char *buf, size_t count);
 309 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 310                         char *buf);
 311
 312 /* Registration functions for complex triggers */
 313 extern int led_trigger_register(struct led_trigger *trigger);
 314 extern void led_trigger_unregister(struct led_trigger *trigger);
 315 extern int devm_led_trigger_register(struct device *dev,
 316                                      struct led_trigger *trigger);
 317
 318 extern void led_trigger_register_simple(const char *name,
 319                                 struct led_trigger **trigger);
 320 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 321 extern void led_trigger_event(struct led_trigger *trigger,
 322                                 enum led_brightness event);
 323 extern void led_trigger_blink(struct led_trigger *trigger,
 324                               unsigned long *delay_on,
 325                               unsigned long *delay_off);
 326 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 327                                       unsigned long *delay_on,
 328                                       unsigned long *delay_off,
 329                                       int invert);
 330 extern void led_trigger_set_default(struct led_classdev *led_cdev);
 331 extern int led_trigger_set(struct led_classdev *led_cdev,
 332                            struct led_trigger *trigger);
 333 extern void led_trigger_remove(struct led_classdev *led_cdev);
 334
 335 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
 336                                         void *trigger_data)
 337 {
 338         led_cdev->trigger_data = trigger_data;
 339 }
 340
 341 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 342 {
 343         return led_cdev->trigger_data;
 344 }
 345
 346 /**
 347  * led_trigger_rename_static - rename a trigger
 348  * @name: the new trigger name
 349  * @trig: the LED trigger to rename
 350  *
 351  * Change a LED trigger name by copying the string passed in
 352  * name into current trigger name, which MUST be large
 353  * enough for the new string.
 354  *
 355  * Note that name must NOT point to the same string used
 356  * during LED registration, as that could lead to races.
 357  *
 358  * This is meant to be used on triggers with statically
 359  * allocated name.
 360  */
 361 extern void led_trigger_rename_static(const char *name,
 362                                       struct led_trigger *trig);
 363
 364 #define module_led_trigger(__led_trigger) \
 365         module_driver(__led_trigger, led_trigger_register, \
 366                       led_trigger_unregister)
 367
 368 #else
 369
 370 /* Trigger has no members */
 371 struct led_trigger {};
 372
 373 /* Trigger inline empty functions */
 374 static inline void led_trigger_register_simple(const char *name,
 375                                         struct led_trigger **trigger) {}
 376 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 377 static inline void led_trigger_event(struct led_trigger *trigger,
 378                                 enum led_brightness event) {}
 379 static inline void led_trigger_blink(struct led_trigger *trigger,
 380                                       unsigned long *delay_on,
 381                                       unsigned long *delay_off) {}
 382 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 383                                       unsigned long *delay_on,
 384                                       unsigned long *delay_off,
 385                                       int invert) {}
 386 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 387 static inline int led_trigger_set(struct led_classdev *led_cdev,
 388                                   struct led_trigger *trigger)
 389 {
 390         return 0;
 391 }
 392
 393 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 394 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
 395 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 396 {
 397         return NULL;
 398 }
 399
 400 #endif /* CONFIG_LEDS_TRIGGERS */
 401
 402 /* Trigger specific functions */
 403 #ifdef CONFIG_LEDS_TRIGGER_DISK
 404 extern void ledtrig_disk_activity(bool write);
 405 #else
 406 static inline void ledtrig_disk_activity(bool write) {}
 407 #endif
 408
 409 #ifdef CONFIG_LEDS_TRIGGER_MTD
 410 extern void ledtrig_mtd_activity(void);
 411 #else
 412 static inline void ledtrig_mtd_activity(void) {}
 413 #endif
 414
 415 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 416 extern void ledtrig_flash_ctrl(bool on);
 417 extern void ledtrig_torch_ctrl(bool on);
 418 #else
 419 static inline void ledtrig_flash_ctrl(bool on) {}
 420 static inline void ledtrig_torch_ctrl(bool on) {}
 421 #endif
 422
 423 /*
 424  * Generic LED platform data for describing LED names and default triggers.
 425  */
 426 struct led_info {
 427         const char      *name;
 428         const char      *default_trigger;
 429         int             flags;
 430 };
 431
 432 struct led_platform_data {
 433         int             num_leds;
 434         struct led_info *leds;
 435 };
 436
 437 struct gpio_desc;
 438 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 439                                 unsigned long *delay_on,
 440                                 unsigned long *delay_off);
 441
 442 /* For the leds-gpio driver */
 443 struct gpio_led {
 444         const char *name;
 445         const char *default_trigger;
 446         unsigned        gpio;
 447         unsigned        active_low : 1;
 448         unsigned        retain_state_suspended : 1;
 449         unsigned        panic_indicator : 1;
 450         unsigned        default_state : 2;
 451         unsigned        retain_state_shutdown : 1;
 452         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 453         struct gpio_desc *gpiod;
 454 };
 455 #define LEDS_GPIO_DEFSTATE_OFF          0
 456 #define LEDS_GPIO_DEFSTATE_ON           1
 457 #define LEDS_GPIO_DEFSTATE_KEEP         2
 458
 459 struct gpio_led_platform_data {
 460         int             num_leds;
 461         const struct gpio_led *leds;
 462
 463 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 464 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 465 #define GPIO_LED_BLINK          2       /* Please, blink */
 466         gpio_blink_set_t        gpio_blink_set;
 467 };
 468
 469 #ifdef CONFIG_NEW_LEDS
 470 struct platform_device *gpio_led_register_device(
 471                 int id, const struct gpio_led_platform_data *pdata);
 472 #else
 473 static inline struct platform_device *gpio_led_register_device(
 474                 int id, const struct gpio_led_platform_data *pdata)
 475 {
 476         return 0;
 477 }
 478 #endif
 479
 480 enum cpu_led_event {
 481         CPU_LED_IDLE_START,     /* CPU enters idle */
 482         CPU_LED_IDLE_END,       /* CPU idle ends */
 483         CPU_LED_START,          /* Machine starts, especially resume */
 484         CPU_LED_STOP,           /* Machine stops, especially suspend */
 485         CPU_LED_HALTED,         /* Machine shutdown */
 486 };
 487 #ifdef CONFIG_LEDS_TRIGGER_CPU
 488 extern void ledtrig_cpu(enum cpu_led_event evt);
 489 #else
 490 static inline void ledtrig_cpu(enum cpu_led_event evt)
 491 {
 492         return;
 493 }
 494 #endif
 495
 496 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 497 extern void led_classdev_notify_brightness_hw_changed(
 498         struct led_classdev *led_cdev, enum led_brightness brightness);
 499 #else
 500 static inline void led_classdev_notify_brightness_hw_changed(
 501         struct led_classdev *led_cdev, enum led_brightness brightness) { }
 502 #endif
 503
 504 /**
 505  * struct led_pattern - pattern interval settings
 506  * @delta_t: pattern interval delay, in milliseconds
 507  * @brightness: pattern interval brightness
 508  */
 509 struct led_pattern {
 510         u32 delta_t;
 511         int brightness;
 512 };
 513
 514 enum led_audio {
 515         LED_AUDIO_MUTE,         /* master mute LED */
 516         LED_AUDIO_MICMUTE,      /* mic mute LED */
 517         NUM_AUDIO_LEDS
 518 };
 519
 520 #if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
 521 enum led_brightness ledtrig_audio_get(enum led_audio type);
 522 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
 523 #else
 524 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
 525 {
 526         return LED_OFF;
 527 }
 528 static inline void ledtrig_audio_set(enum led_audio type,
 529                                      enum led_brightness state)
 530 {
 531 }
 532 #endif
 533
 534 #endif          /* __LINUX_LEDS_H_INCLUDED */