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