linux/include/linux/leds.h
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   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 <dt-bindings/leds/common.h>
  12#include <linux/device.h>
  13#include <linux/kernfs.h>
  14#include <linux/list.h>
  15#include <linux/mutex.h>
  16#include <linux/rwsem.h>
  17#include <linux/spinlock.h>
  18#include <linux/timer.h>
  19#include <linux/workqueue.h>
  20
  21struct device;
  22struct led_pattern;
  23struct device_node;
  24/*
  25 * LED Core
  26 */
  27
  28/* This is obsolete/useless. We now support variable maximum brightness. */
  29enum led_brightness {
  30        LED_OFF         = 0,
  31        LED_ON          = 1,
  32        LED_HALF        = 127,
  33        LED_FULL        = 255,
  34};
  35
  36enum led_default_state {
  37        LEDS_DEFSTATE_OFF       = 0,
  38        LEDS_DEFSTATE_ON        = 1,
  39        LEDS_DEFSTATE_KEEP      = 2,
  40};
  41
  42struct led_init_data {
  43        /* device fwnode handle */
  44        struct fwnode_handle *fwnode;
  45        /*
  46         * default <color:function> tuple, for backward compatibility
  47         * with in-driver hard-coded LED names used as a fallback when
  48         * DT "label" property is absent; it should be set to NULL
  49         * in new LED class drivers.
  50         */
  51        const char *default_label;
  52        /*
  53         * string to be used for devicename section of LED class device
  54         * either for label based LED name composition path or for fwnode
  55         * based when devname_mandatory is true
  56         */
  57        const char *devicename;
  58        /*
  59         * indicates if LED name should always comprise devicename section;
  60         * only LEDs exposed by drivers of hot-pluggable devices should
  61         * set it to true
  62         */
  63        bool devname_mandatory;
  64};
  65
  66struct led_hw_trigger_type {
  67        int dummy;
  68};
  69
  70struct led_classdev {
  71        const char              *name;
  72        unsigned int brightness;
  73        unsigned int max_brightness;
  74        int                      flags;
  75
  76        /* Lower 16 bits reflect status */
  77#define LED_SUSPENDED           BIT(0)
  78#define LED_UNREGISTERING       BIT(1)
  79        /* Upper 16 bits reflect control information */
  80#define LED_CORE_SUSPENDRESUME  BIT(16)
  81#define LED_SYSFS_DISABLE       BIT(17)
  82#define LED_DEV_CAP_FLASH       BIT(18)
  83#define LED_HW_PLUGGABLE        BIT(19)
  84#define LED_PANIC_INDICATOR     BIT(20)
  85#define LED_BRIGHT_HW_CHANGED   BIT(21)
  86#define LED_RETAIN_AT_SHUTDOWN  BIT(22)
  87#define LED_INIT_DEFAULT_TRIGGER BIT(23)
  88
  89        /* set_brightness_work / blink_timer flags, atomic, private. */
  90        unsigned long           work_flags;
  91
  92#define LED_BLINK_SW                    0
  93#define LED_BLINK_ONESHOT               1
  94#define LED_BLINK_ONESHOT_STOP          2
  95#define LED_BLINK_INVERT                3
  96#define LED_BLINK_BRIGHTNESS_CHANGE     4
  97#define LED_BLINK_DISABLE               5
  98
  99        /* Set LED brightness level
 100         * Must not sleep. Use brightness_set_blocking for drivers
 101         * that can sleep while setting brightness.
 102         */
 103        void            (*brightness_set)(struct led_classdev *led_cdev,
 104                                          enum led_brightness brightness);
 105        /*
 106         * Set LED brightness level immediately - it can block the caller for
 107         * the time required for accessing a LED device register.
 108         */
 109        int (*brightness_set_blocking)(struct led_classdev *led_cdev,
 110                                       enum led_brightness brightness);
 111        /* Get LED brightness level */
 112        enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
 113
 114        /*
 115         * Activate hardware accelerated blink, delays are in milliseconds
 116         * and if both are zero then a sensible default should be chosen.
 117         * The call should adjust the timings in that case and if it can't
 118         * match the values specified exactly.
 119         * Deactivate blinking again when the brightness is set to LED_OFF
 120         * via the brightness_set() callback.
 121         */
 122        int             (*blink_set)(struct led_classdev *led_cdev,
 123                                     unsigned long *delay_on,
 124                                     unsigned long *delay_off);
 125
 126        int (*pattern_set)(struct led_classdev *led_cdev,
 127                           struct led_pattern *pattern, u32 len, int repeat);
 128        int (*pattern_clear)(struct led_classdev *led_cdev);
 129
 130        struct device           *dev;
 131        const struct attribute_group    **groups;
 132
 133        struct list_head         node;                  /* LED Device list */
 134        const char              *default_trigger;       /* Trigger to use */
 135
 136        unsigned long            blink_delay_on, blink_delay_off;
 137        struct timer_list        blink_timer;
 138        int                      blink_brightness;
 139        int                      new_blink_brightness;
 140        void                    (*flash_resume)(struct led_classdev *led_cdev);
 141
 142        struct work_struct      set_brightness_work;
 143        int                     delayed_set_value;
 144
 145#ifdef CONFIG_LEDS_TRIGGERS
 146        /* Protects the trigger data below */
 147        struct rw_semaphore      trigger_lock;
 148
 149        struct led_trigger      *trigger;
 150        struct list_head         trig_list;
 151        void                    *trigger_data;
 152        /* true if activated - deactivate routine uses it to do cleanup */
 153        bool                    activated;
 154
 155        /* LEDs that have private triggers have this set */
 156        struct led_hw_trigger_type      *trigger_type;
 157#endif
 158
 159#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 160        int                      brightness_hw_changed;
 161        struct kernfs_node      *brightness_hw_changed_kn;
 162#endif
 163
 164        /* Ensures consistent access to the LED Flash Class device */
 165        struct mutex            led_access;
 166};
 167
 168/**
 169 * led_classdev_register_ext - register a new object of LED class with
 170 *                             init data
 171 * @parent: LED controller device this LED is driven by
 172 * @led_cdev: the led_classdev structure for this device
 173 * @init_data: the LED class device initialization data
 174 *
 175 * Register a new object of LED class, with name derived from init_data.
 176 *
 177 * Returns: 0 on success or negative error value on failure
 178 */
 179int led_classdev_register_ext(struct device *parent,
 180                                     struct led_classdev *led_cdev,
 181                                     struct led_init_data *init_data);
 182
 183/**
 184 * led_classdev_register - register a new object of LED class
 185 * @parent: LED controller device this LED is driven by
 186 * @led_cdev: the led_classdev structure for this device
 187 *
 188 * Register a new object of LED class, with name derived from the name property
 189 * of passed led_cdev argument.
 190 *
 191 * Returns: 0 on success or negative error value on failure
 192 */
 193static inline int led_classdev_register(struct device *parent,
 194                                        struct led_classdev *led_cdev)
 195{
 196        return led_classdev_register_ext(parent, led_cdev, NULL);
 197}
 198
 199int devm_led_classdev_register_ext(struct device *parent,
 200                                          struct led_classdev *led_cdev,
 201                                          struct led_init_data *init_data);
 202
 203static inline int devm_led_classdev_register(struct device *parent,
 204                                             struct led_classdev *led_cdev)
 205{
 206        return devm_led_classdev_register_ext(parent, led_cdev, NULL);
 207}
 208void led_classdev_unregister(struct led_classdev *led_cdev);
 209void devm_led_classdev_unregister(struct device *parent,
 210                                  struct led_classdev *led_cdev);
 211void led_classdev_suspend(struct led_classdev *led_cdev);
 212void led_classdev_resume(struct led_classdev *led_cdev);
 213
 214extern struct led_classdev *of_led_get(struct device_node *np, int index);
 215extern void led_put(struct led_classdev *led_cdev);
 216struct led_classdev *__must_check devm_of_led_get(struct device *dev,
 217                                                  int index);
 218
 219/**
 220 * led_blink_set - set blinking with software fallback
 221 * @led_cdev: the LED to start blinking
 222 * @delay_on: the time it should be on (in ms)
 223 * @delay_off: the time it should ble off (in ms)
 224 *
 225 * This function makes the LED blink, attempting to use the
 226 * hardware acceleration if possible, but falling back to
 227 * software blinking if there is no hardware blinking or if
 228 * the LED refuses the passed values.
 229 *
 230 * Note that if software blinking is active, simply calling
 231 * led_cdev->brightness_set() will not stop the blinking,
 232 * use led_classdev_brightness_set() instead.
 233 */
 234void led_blink_set(struct led_classdev *led_cdev, unsigned long *delay_on,
 235                   unsigned long *delay_off);
 236/**
 237 * led_blink_set_oneshot - do a oneshot software blink
 238 * @led_cdev: the LED to start blinking
 239 * @delay_on: the time it should be on (in ms)
 240 * @delay_off: the time it should ble off (in ms)
 241 * @invert: blink off, then on, leaving the led on
 242 *
 243 * This function makes the LED blink one time for delay_on +
 244 * delay_off time, ignoring the request if another one-shot
 245 * blink is already in progress.
 246 *
 247 * If invert is set, led blinks for delay_off first, then for
 248 * delay_on and leave the led on after the on-off cycle.
 249 */
 250void led_blink_set_oneshot(struct led_classdev *led_cdev,
 251                           unsigned long *delay_on, unsigned long *delay_off,
 252                           int invert);
 253/**
 254 * led_set_brightness - set LED brightness
 255 * @led_cdev: the LED to set
 256 * @brightness: the brightness to set it to
 257 *
 258 * Set an LED's brightness, and, if necessary, cancel the
 259 * software blink timer that implements blinking when the
 260 * hardware doesn't. This function is guaranteed not to sleep.
 261 */
 262void led_set_brightness(struct led_classdev *led_cdev, unsigned int brightness);
 263
 264/**
 265 * led_set_brightness_sync - set LED brightness synchronously
 266 * @led_cdev: the LED to set
 267 * @value: the brightness to set it to
 268 *
 269 * Set an LED's brightness immediately. This function will block
 270 * the caller for the time required for accessing device registers,
 271 * and it can sleep.
 272 *
 273 * Returns: 0 on success or negative error value on failure
 274 */
 275int led_set_brightness_sync(struct led_classdev *led_cdev, unsigned int value);
 276
 277/**
 278 * led_update_brightness - update LED brightness
 279 * @led_cdev: the LED to query
 280 *
 281 * Get an LED's current brightness and update led_cdev->brightness
 282 * member with the obtained value.
 283 *
 284 * Returns: 0 on success or negative error value on failure
 285 */
 286int led_update_brightness(struct led_classdev *led_cdev);
 287
 288/**
 289 * led_get_default_pattern - return default pattern
 290 *
 291 * @led_cdev: the LED to get default pattern for
 292 * @size:     pointer for storing the number of elements in returned array,
 293 *            modified only if return != NULL
 294 *
 295 * Return:    Allocated array of integers with default pattern from device tree
 296 *            or NULL.  Caller is responsible for kfree().
 297 */
 298u32 *led_get_default_pattern(struct led_classdev *led_cdev, unsigned int *size);
 299
 300/**
 301 * led_sysfs_disable - disable LED sysfs interface
 302 * @led_cdev: the LED to set
 303 *
 304 * Disable the led_cdev's sysfs interface.
 305 */
 306void led_sysfs_disable(struct led_classdev *led_cdev);
 307
 308/**
 309 * led_sysfs_enable - enable LED sysfs interface
 310 * @led_cdev: the LED to set
 311 *
 312 * Enable the led_cdev's sysfs interface.
 313 */
 314void led_sysfs_enable(struct led_classdev *led_cdev);
 315
 316/**
 317 * led_compose_name - compose LED class device name
 318 * @dev: LED controller device object
 319 * @init_data: the LED class device initialization data
 320 * @led_classdev_name: composed LED class device name
 321 *
 322 * Create LED class device name basing on the provided init_data argument.
 323 * The name can have <devicename:color:function> or <color:function>.
 324 * form, depending on the init_data configuration.
 325 *
 326 * Returns: 0 on success or negative error value on failure
 327 */
 328int led_compose_name(struct device *dev, struct led_init_data *init_data,
 329                     char *led_classdev_name);
 330
 331/**
 332 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 333 * @led_cdev: the LED to query
 334 *
 335 * Returns: true if the led_cdev's sysfs interface is disabled.
 336 */
 337static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 338{
 339        return led_cdev->flags & LED_SYSFS_DISABLE;
 340}
 341
 342/*
 343 * LED Triggers
 344 */
 345/* Registration functions for simple triggers */
 346#define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 347#define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 348
 349#ifdef CONFIG_LEDS_TRIGGERS
 350
 351#define TRIG_NAME_MAX 50
 352
 353struct led_trigger {
 354        /* Trigger Properties */
 355        const char       *name;
 356        int             (*activate)(struct led_classdev *led_cdev);
 357        void            (*deactivate)(struct led_classdev *led_cdev);
 358
 359        /* LED-private triggers have this set */
 360        struct led_hw_trigger_type *trigger_type;
 361
 362        /* LEDs under control by this trigger (for simple triggers) */
 363        spinlock_t        leddev_list_lock;
 364        struct list_head  led_cdevs;
 365
 366        /* Link to next registered trigger */
 367        struct list_head  next_trig;
 368
 369        const struct attribute_group **groups;
 370};
 371
 372/*
 373 * Currently the attributes in struct led_trigger::groups are added directly to
 374 * the LED device. As this might change in the future, the following
 375 * macros abstract getting the LED device and its trigger_data from the dev
 376 * parameter passed to the attribute accessor functions.
 377 */
 378#define led_trigger_get_led(dev)        ((struct led_classdev *)dev_get_drvdata((dev)))
 379#define led_trigger_get_drvdata(dev)    (led_get_trigger_data(led_trigger_get_led(dev)))
 380
 381/* Registration functions for complex triggers */
 382int led_trigger_register(struct led_trigger *trigger);
 383void led_trigger_unregister(struct led_trigger *trigger);
 384int devm_led_trigger_register(struct device *dev,
 385                                     struct led_trigger *trigger);
 386
 387void led_trigger_register_simple(const char *name,
 388                                struct led_trigger **trigger);
 389void led_trigger_unregister_simple(struct led_trigger *trigger);
 390void led_trigger_event(struct led_trigger *trigger,  enum led_brightness event);
 391void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
 392                       unsigned long *delay_off);
 393void led_trigger_blink_oneshot(struct led_trigger *trigger,
 394                               unsigned long *delay_on,
 395                               unsigned long *delay_off,
 396                               int invert);
 397void led_trigger_set_default(struct led_classdev *led_cdev);
 398int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
 399void led_trigger_remove(struct led_classdev *led_cdev);
 400
 401static inline void led_set_trigger_data(struct led_classdev *led_cdev,
 402                                        void *trigger_data)
 403{
 404        led_cdev->trigger_data = trigger_data;
 405}
 406
 407static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 408{
 409        return led_cdev->trigger_data;
 410}
 411
 412/**
 413 * led_trigger_rename_static - rename a trigger
 414 * @name: the new trigger name
 415 * @trig: the LED trigger to rename
 416 *
 417 * Change a LED trigger name by copying the string passed in
 418 * name into current trigger name, which MUST be large
 419 * enough for the new string.
 420 *
 421 * Note that name must NOT point to the same string used
 422 * during LED registration, as that could lead to races.
 423 *
 424 * This is meant to be used on triggers with statically
 425 * allocated name.
 426 */
 427void led_trigger_rename_static(const char *name, struct led_trigger *trig);
 428
 429#define module_led_trigger(__led_trigger) \
 430        module_driver(__led_trigger, led_trigger_register, \
 431                      led_trigger_unregister)
 432
 433#else
 434
 435/* Trigger has no members */
 436struct led_trigger {};
 437
 438/* Trigger inline empty functions */
 439static inline void led_trigger_register_simple(const char *name,
 440                                        struct led_trigger **trigger) {}
 441static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 442static inline void led_trigger_event(struct led_trigger *trigger,
 443                                enum led_brightness event) {}
 444static inline void led_trigger_blink(struct led_trigger *trigger,
 445                                      unsigned long *delay_on,
 446                                      unsigned long *delay_off) {}
 447static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 448                                      unsigned long *delay_on,
 449                                      unsigned long *delay_off,
 450                                      int invert) {}
 451static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 452static inline int led_trigger_set(struct led_classdev *led_cdev,
 453                                  struct led_trigger *trigger)
 454{
 455        return 0;
 456}
 457
 458static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 459static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
 460static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 461{
 462        return NULL;
 463}
 464
 465#endif /* CONFIG_LEDS_TRIGGERS */
 466
 467/* Trigger specific functions */
 468#ifdef CONFIG_LEDS_TRIGGER_DISK
 469void ledtrig_disk_activity(bool write);
 470#else
 471static inline void ledtrig_disk_activity(bool write) {}
 472#endif
 473
 474#ifdef CONFIG_LEDS_TRIGGER_MTD
 475void ledtrig_mtd_activity(void);
 476#else
 477static inline void ledtrig_mtd_activity(void) {}
 478#endif
 479
 480#if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 481void ledtrig_flash_ctrl(bool on);
 482void ledtrig_torch_ctrl(bool on);
 483#else
 484static inline void ledtrig_flash_ctrl(bool on) {}
 485static inline void ledtrig_torch_ctrl(bool on) {}
 486#endif
 487
 488/*
 489 * Generic LED platform data for describing LED names and default triggers.
 490 */
 491struct led_info {
 492        const char      *name;
 493        const char      *default_trigger;
 494        int             flags;
 495};
 496
 497struct led_platform_data {
 498        int             num_leds;
 499        struct led_info *leds;
 500};
 501
 502struct led_properties {
 503        u32             color;
 504        bool            color_present;
 505        const char      *function;
 506        u32             func_enum;
 507        bool            func_enum_present;
 508        const char      *label;
 509};
 510
 511struct gpio_desc;
 512typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 513                                unsigned long *delay_on,
 514                                unsigned long *delay_off);
 515
 516/* For the leds-gpio driver */
 517struct gpio_led {
 518        const char *name;
 519        const char *default_trigger;
 520        unsigned        gpio;
 521        unsigned        active_low : 1;
 522        unsigned        retain_state_suspended : 1;
 523        unsigned        panic_indicator : 1;
 524        unsigned        default_state : 2;
 525        unsigned        retain_state_shutdown : 1;
 526        /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 527        struct gpio_desc *gpiod;
 528};
 529#define LEDS_GPIO_DEFSTATE_OFF          LEDS_DEFSTATE_OFF
 530#define LEDS_GPIO_DEFSTATE_ON           LEDS_DEFSTATE_ON
 531#define LEDS_GPIO_DEFSTATE_KEEP         LEDS_DEFSTATE_KEEP
 532
 533struct gpio_led_platform_data {
 534        int             num_leds;
 535        const struct gpio_led *leds;
 536
 537#define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 538#define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 539#define GPIO_LED_BLINK          2       /* Please, blink */
 540        gpio_blink_set_t        gpio_blink_set;
 541};
 542
 543#ifdef CONFIG_NEW_LEDS
 544struct platform_device *gpio_led_register_device(
 545                int id, const struct gpio_led_platform_data *pdata);
 546#else
 547static inline struct platform_device *gpio_led_register_device(
 548                int id, const struct gpio_led_platform_data *pdata)
 549{
 550        return 0;
 551}
 552#endif
 553
 554enum cpu_led_event {
 555        CPU_LED_IDLE_START,     /* CPU enters idle */
 556        CPU_LED_IDLE_END,       /* CPU idle ends */
 557        CPU_LED_START,          /* Machine starts, especially resume */
 558        CPU_LED_STOP,           /* Machine stops, especially suspend */
 559        CPU_LED_HALTED,         /* Machine shutdown */
 560};
 561#ifdef CONFIG_LEDS_TRIGGER_CPU
 562void ledtrig_cpu(enum cpu_led_event evt);
 563#else
 564static inline void ledtrig_cpu(enum cpu_led_event evt)
 565{
 566        return;
 567}
 568#endif
 569
 570#ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 571void led_classdev_notify_brightness_hw_changed(
 572        struct led_classdev *led_cdev, unsigned int brightness);
 573#else
 574static inline void led_classdev_notify_brightness_hw_changed(
 575        struct led_classdev *led_cdev, enum led_brightness brightness) { }
 576#endif
 577
 578/**
 579 * struct led_pattern - pattern interval settings
 580 * @delta_t: pattern interval delay, in milliseconds
 581 * @brightness: pattern interval brightness
 582 */
 583struct led_pattern {
 584        u32 delta_t;
 585        int brightness;
 586};
 587
 588enum led_audio {
 589        LED_AUDIO_MUTE,         /* master mute LED */
 590        LED_AUDIO_MICMUTE,      /* mic mute LED */
 591        NUM_AUDIO_LEDS
 592};
 593
 594#if IS_ENABLED(CONFIG_LEDS_TRIGGER_AUDIO)
 595enum led_brightness ledtrig_audio_get(enum led_audio type);
 596void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
 597#else
 598static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
 599{
 600        return LED_OFF;
 601}
 602static inline void ledtrig_audio_set(enum led_audio type,
 603                                     enum led_brightness state)
 604{
 605}
 606#endif
 607
 608#endif          /* __LINUX_LEDS_H_INCLUDED */
 609