include/linux/leds.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Driver model for leds and led triggers
   4  *
   5  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
   6  * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
   7  */
   8 #ifndef __LINUX_LEDS_H_INCLUDED
   9 #define __LINUX_LEDS_H_INCLUDED
  10
  11 #include <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
  21 struct device;
  22 struct led_pattern;
  23 struct device_node;
  24 /*
  25  * LED Core
  26  */
  27
  28 /* This is obsolete/useless. We now support variable maximum brightness. */
  29 enum led_brightness {
  30         LED_OFF         = 0,
  31         LED_ON          = 1,
  32         LED_HALF        = 127,
  33         LED_FULL        = 255,
  34 };
  35
  36 enum led_default_state {
  37         LEDS_DEFSTATE_OFF       = 0,
  38         LEDS_DEFSTATE_ON        = 1,
  39         LEDS_DEFSTATE_KEEP      = 2,
  40 };
  41
  42 struct 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
  66 struct led_hw_trigger_type {
  67         int dummy;
  68 };
  69
  70 struct 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  */
 179 int 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  */
 193 static 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
 199 int devm_led_classdev_register_ext(struct device *parent,
 200                                           struct led_classdev *led_cdev,
 201                                           struct led_init_data *init_data);
 202
 203 static 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 }
 208 void led_classdev_unregister(struct led_classdev *led_cdev);
 209 void devm_led_classdev_unregister(struct device *parent,
 210                                   struct led_classdev *led_cdev);
 211 void led_classdev_suspend(struct led_classdev *led_cdev);
 212 void led_classdev_resume(struct led_classdev *led_cdev);
 213
 214 extern struct led_classdev *of_led_get(struct device_node *np, int index);
 215 extern void led_put(struct led_classdev *led_cdev);
 216 struct 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  */
 234 void 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  */
 250 void 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  */
 262 void 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  */
 275 int 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  */
 286 int 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  */
 298 u32 *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  */
 306 void 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  */
 314 void 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  */
 328 int 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  */
 337 static 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
 353 struct 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         rwlock_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 */
 382 int led_trigger_register(struct led_trigger *trigger);
 383 void led_trigger_unregister(struct led_trigger *trigger);
 384 int devm_led_trigger_register(struct device *dev,
 385                                      struct led_trigger *trigger);
 386
 387 void led_trigger_register_simple(const char *name,
 388                                 struct led_trigger **trigger);
 389 void led_trigger_unregister_simple(struct led_trigger *trigger);
 390 void led_trigger_event(struct led_trigger *trigger,  enum led_brightness event);
 391 void led_trigger_blink(struct led_trigger *trigger, unsigned long *delay_on,
 392                        unsigned long *delay_off);
 393 void led_trigger_blink_oneshot(struct led_trigger *trigger,
 394                                unsigned long *delay_on,
 395                                unsigned long *delay_off,
 396                                int invert);
 397 void led_trigger_set_default(struct led_classdev *led_cdev);
 398 int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger);
 399 void led_trigger_remove(struct led_classdev *led_cdev);
 400
 401 static 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
 407 static 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  */
 427 void 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 */
 436 struct led_trigger {};
 437
 438 /* Trigger inline empty functions */
 439 static inline void led_trigger_register_simple(const char *name,
 440                                         struct led_trigger **trigger) {}
 441 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 442 static inline void led_trigger_event(struct led_trigger *trigger,
 443                                 enum led_brightness event) {}
 444 static inline void led_trigger_blink(struct led_trigger *trigger,
 445                                       unsigned long *delay_on,
 446                                       unsigned long *delay_off) {}
 447 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 448                                       unsigned long *delay_on,
 449                                       unsigned long *delay_off,
 450                                       int invert) {}
 451 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 452 static inline int led_trigger_set(struct led_classdev *led_cdev,
 453                                   struct led_trigger *trigger)
 454 {
 455         return 0;
 456 }
 457
 458 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 459 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
 460 static 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
 469 void ledtrig_disk_activity(bool write);
 470 #else
 471 static inline void ledtrig_disk_activity(bool write) {}
 472 #endif
 473
 474 #ifdef CONFIG_LEDS_TRIGGER_MTD
 475 void ledtrig_mtd_activity(void);
 476 #else
 477 static inline void ledtrig_mtd_activity(void) {}
 478 #endif
 479
 480 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 481 void ledtrig_flash_ctrl(bool on);
 482 void ledtrig_torch_ctrl(bool on);
 483 #else
 484 static inline void ledtrig_flash_ctrl(bool on) {}
 485 static inline void ledtrig_torch_ctrl(bool on) {}
 486 #endif
 487
 488 /*
 489  * Generic LED platform data for describing LED names and default triggers.
 490  */
 491 struct led_info {
 492         const char      *name;
 493         const char      *default_trigger;
 494         int             flags;
 495 };
 496
 497 struct led_platform_data {
 498         int             num_leds;
 499         struct led_info *leds;
 500 };
 501
 502 struct 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
 511 struct gpio_desc;
 512 typedef 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 */
 517 struct 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
 533 struct 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
 544 struct platform_device *gpio_led_register_device(
 545                 int id, const struct gpio_led_platform_data *pdata);
 546 #else
 547 static 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
 554 enum 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
 562 void ledtrig_cpu(enum cpu_led_event evt);
 563 #else
 564 static inline void ledtrig_cpu(enum cpu_led_event evt)
 565 {
 566         return;
 567 }
 568 #endif
 569
 570 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 571 void led_classdev_notify_brightness_hw_changed(
 572         struct led_classdev *led_cdev, unsigned int brightness);
 573 #else
 574 static 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  */
 583 struct led_pattern {
 584         u32 delta_t;
 585         int brightness;
 586 };
 587
 588 enum 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)
 595 enum led_brightness ledtrig_audio_get(enum led_audio type);
 596 void ledtrig_audio_set(enum led_audio type, enum led_brightness state);
 597 #else
 598 static inline enum led_brightness ledtrig_audio_get(enum led_audio type)
 599 {
 600         return LED_OFF;
 601 }
 602 static 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 */