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  28/* This is obsolete/useless.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