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  28/* This is obsolete/useless.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