include/linux/leds.h

   1 /*
   2  * Driver model for leds and led triggers
   3  *
   4  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
   5  * Copyright (C) 2005 Richard Purdie <rpurdie@openedhand.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  */
  12 #ifndef __LINUX_LEDS_H_INCLUDED
  13 #define __LINUX_LEDS_H_INCLUDED
  14
  15 #include <linux/device.h>
  16 #include <linux/kernfs.h>
  17 #include <linux/list.h>
  18 #include <linux/mutex.h>
  19 #include <linux/rwsem.h>
  20 #include <linux/spinlock.h>
  21 #include <linux/timer.h>
  22 #include <linux/workqueue.h>
  23
  24 struct device;
  25 struct led_pattern;
  26 /*
  27  * LED Core
  28  */
  29
  30 enum led_brightness {
  31         LED_OFF         = 0,
  32         LED_ON          = 1,
  33         LED_HALF        = 127,
  34         LED_FULL        = 255,
  35 };
  36
  37 struct led_classdev {
  38         const char              *name;
  39         enum led_brightness      brightness;
  40         enum led_brightness      max_brightness;
  41         int                      flags;
  42
  43         /* Lower 16 bits reflect status */
  44 #define LED_SUSPENDED           BIT(0)
  45 #define LED_UNREGISTERING       BIT(1)
  46         /* Upper 16 bits reflect control information */
  47 #define LED_CORE_SUSPENDRESUME  BIT(16)
  48 #define LED_SYSFS_DISABLE       BIT(17)
  49 #define LED_DEV_CAP_FLASH       BIT(18)
  50 #define LED_HW_PLUGGABLE        BIT(19)
  51 #define LED_PANIC_INDICATOR     BIT(20)
  52 #define LED_BRIGHT_HW_CHANGED   BIT(21)
  53 #define LED_RETAIN_AT_SHUTDOWN  BIT(22)
  54
  55         /* set_brightness_work / blink_timer flags, atomic, private. */
  56         unsigned long           work_flags;
  57
  58 #define LED_BLINK_SW                    0
  59 #define LED_BLINK_ONESHOT               1
  60 #define LED_BLINK_ONESHOT_STOP          2
  61 #define LED_BLINK_INVERT                3
  62 #define LED_BLINK_BRIGHTNESS_CHANGE     4
  63 #define LED_BLINK_DISABLE               5
  64
  65         /* Set LED brightness level
  66          * Must not sleep. Use brightness_set_blocking for drivers
  67          * that can sleep while setting brightness.
  68          */
  69         void            (*brightness_set)(struct led_classdev *led_cdev,
  70                                           enum led_brightness brightness);
  71         /*
  72          * Set LED brightness level immediately - it can block the caller for
  73          * the time required for accessing a LED device register.
  74          */
  75         int (*brightness_set_blocking)(struct led_classdev *led_cdev,
  76                                        enum led_brightness brightness);
  77         /* Get LED brightness level */
  78         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  79
  80         /*
  81          * Activate hardware accelerated blink, delays are in milliseconds
  82          * and if both are zero then a sensible default should be chosen.
  83          * The call should adjust the timings in that case and if it can't
  84          * match the values specified exactly.
  85          * Deactivate blinking again when the brightness is set to LED_OFF
  86          * via the brightness_set() callback.
  87          */
  88         int             (*blink_set)(struct led_classdev *led_cdev,
  89                                      unsigned long *delay_on,
  90                                      unsigned long *delay_off);
  91
  92         int (*pattern_set)(struct led_classdev *led_cdev,
  93                            struct led_pattern *pattern, u32 len, int repeat);
  94         int (*pattern_clear)(struct led_classdev *led_cdev);
  95
  96         struct device           *dev;
  97         const struct attribute_group    **groups;
  98
  99         struct list_head         node;                  /* LED Device list */
 100         const char              *default_trigger;       /* Trigger to use */
 101
 102         unsigned long            blink_delay_on, blink_delay_off;
 103         struct timer_list        blink_timer;
 104         int                      blink_brightness;
 105         int                      new_blink_brightness;
 106         void                    (*flash_resume)(struct led_classdev *led_cdev);
 107
 108         struct work_struct      set_brightness_work;
 109         int                     delayed_set_value;
 110
 111 #ifdef CONFIG_LEDS_TRIGGERS
 112         /* Protects the trigger data below */
 113         struct rw_semaphore      trigger_lock;
 114
 115         struct led_trigger      *trigger;
 116         struct list_head         trig_list;
 117         void                    *trigger_data;
 118         /* true if activated - deactivate routine uses it to do cleanup */
 119         bool                    activated;
 120 #endif
 121
 122 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 123         int                      brightness_hw_changed;
 124         struct kernfs_node      *brightness_hw_changed_kn;
 125 #endif
 126
 127         /* Ensures consistent access to the LED Flash Class device */
 128         struct mutex            led_access;
 129 };
 130
 131 extern int of_led_classdev_register(struct device *parent,
 132                                     struct device_node *np,
 133                                     struct led_classdev *led_cdev);
 134 #define led_classdev_register(parent, led_cdev)                         \
 135         of_led_classdev_register(parent, NULL, led_cdev)
 136 extern int devm_of_led_classdev_register(struct device *parent,
 137                                          struct device_node *np,
 138                                          struct led_classdev *led_cdev);
 139 #define devm_led_classdev_register(parent, led_cdev)                    \
 140         devm_of_led_classdev_register(parent, NULL, led_cdev)
 141 extern void led_classdev_unregister(struct led_classdev *led_cdev);
 142 extern void devm_led_classdev_unregister(struct device *parent,
 143                                          struct led_classdev *led_cdev);
 144 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 145 extern void led_classdev_resume(struct led_classdev *led_cdev);
 146
 147 /**
 148  * led_blink_set - set blinking with software fallback
 149  * @led_cdev: the LED to start blinking
 150  * @delay_on: the time it should be on (in ms)
 151  * @delay_off: the time it should ble off (in ms)
 152  *
 153  * This function makes the LED blink, attempting to use the
 154  * hardware acceleration if possible, but falling back to
 155  * software blinking if there is no hardware blinking or if
 156  * the LED refuses the passed values.
 157  *
 158  * Note that if software blinking is active, simply calling
 159  * led_cdev->brightness_set() will not stop the blinking,
 160  * use led_classdev_brightness_set() instead.
 161  */
 162 extern void led_blink_set(struct led_classdev *led_cdev,
 163                           unsigned long *delay_on,
 164                           unsigned long *delay_off);
 165 /**
 166  * led_blink_set_oneshot - do a oneshot software blink
 167  * @led_cdev: the LED to start blinking
 168  * @delay_on: the time it should be on (in ms)
 169  * @delay_off: the time it should ble off (in ms)
 170  * @invert: blink off, then on, leaving the led on
 171  *
 172  * This function makes the LED blink one time for delay_on +
 173  * delay_off time, ignoring the request if another one-shot
 174  * blink is already in progress.
 175  *
 176  * If invert is set, led blinks for delay_off first, then for
 177  * delay_on and leave the led on after the on-off cycle.
 178  */
 179 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 180                                   unsigned long *delay_on,
 181                                   unsigned long *delay_off,
 182                                   int invert);
 183 /**
 184  * led_set_brightness - set LED brightness
 185  * @led_cdev: the LED to set
 186  * @brightness: the brightness to set it to
 187  *
 188  * Set an LED's brightness, and, if necessary, cancel the
 189  * software blink timer that implements blinking when the
 190  * hardware doesn't. This function is guaranteed not to sleep.
 191  */
 192 extern void led_set_brightness(struct led_classdev *led_cdev,
 193                                enum led_brightness brightness);
 194
 195 /**
 196  * led_set_brightness_sync - set LED brightness synchronously
 197  * @led_cdev: the LED to set
 198  * @brightness: the brightness to set it to
 199  *
 200  * Set an LED's brightness immediately. This function will block
 201  * the caller for the time required for accessing device registers,
 202  * and it can sleep.
 203  *
 204  * Returns: 0 on success or negative error value on failure
 205  */
 206 extern int led_set_brightness_sync(struct led_classdev *led_cdev,
 207                                    enum led_brightness value);
 208
 209 /**
 210  * led_update_brightness - update LED brightness
 211  * @led_cdev: the LED to query
 212  *
 213  * Get an LED's current brightness and update led_cdev->brightness
 214  * member with the obtained value.
 215  *
 216  * Returns: 0 on success or negative error value on failure
 217  */
 218 extern int led_update_brightness(struct led_classdev *led_cdev);
 219
 220 /**
 221  * led_sysfs_disable - disable LED sysfs interface
 222  * @led_cdev: the LED to set
 223  *
 224  * Disable the led_cdev's sysfs interface.
 225  */
 226 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 227
 228 /**
 229  * led_sysfs_enable - enable LED sysfs interface
 230  * @led_cdev: the LED to set
 231  *
 232  * Enable the led_cdev's sysfs interface.
 233  */
 234 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 235
 236 /**
 237  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 238  * @led_cdev: the LED to query
 239  *
 240  * Returns: true if the led_cdev's sysfs interface is disabled.
 241  */
 242 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 243 {
 244         return led_cdev->flags & LED_SYSFS_DISABLE;
 245 }
 246
 247 /*
 248  * LED Triggers
 249  */
 250 /* Registration functions for simple triggers */
 251 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 252 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 253
 254 #ifdef CONFIG_LEDS_TRIGGERS
 255
 256 #define TRIG_NAME_MAX 50
 257
 258 struct led_trigger {
 259         /* Trigger Properties */
 260         const char       *name;
 261         int             (*activate)(struct led_classdev *led_cdev);
 262         void            (*deactivate)(struct led_classdev *led_cdev);
 263
 264         /* LEDs under control by this trigger (for simple triggers) */
 265         rwlock_t          leddev_list_lock;
 266         struct list_head  led_cdevs;
 267
 268         /* Link to next registered trigger */
 269         struct list_head  next_trig;
 270
 271         const struct attribute_group **groups;
 272 };
 273
 274 /*
 275  * Currently the attributes in struct led_trigger::groups are added directly to
 276  * the LED device. As this might change in the future, the following
 277  * macros abstract getting the LED device and its trigger_data from the dev
 278  * parameter passed to the attribute accessor functions.
 279  */
 280 #define led_trigger_get_led(dev)        ((struct led_classdev *)dev_get_drvdata((dev)))
 281 #define led_trigger_get_drvdata(dev)    (led_get_trigger_data(led_trigger_get_led(dev)))
 282
 283 ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 284                         const char *buf, size_t count);
 285 ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 286                         char *buf);
 287
 288 /* Registration functions for complex triggers */
 289 extern int led_trigger_register(struct led_trigger *trigger);
 290 extern void led_trigger_unregister(struct led_trigger *trigger);
 291 extern int devm_led_trigger_register(struct device *dev,
 292                                      struct led_trigger *trigger);
 293
 294 extern void led_trigger_register_simple(const char *name,
 295                                 struct led_trigger **trigger);
 296 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 297 extern void led_trigger_event(struct led_trigger *trigger,
 298                                 enum led_brightness event);
 299 extern void led_trigger_blink(struct led_trigger *trigger,
 300                               unsigned long *delay_on,
 301                               unsigned long *delay_off);
 302 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 303                                       unsigned long *delay_on,
 304                                       unsigned long *delay_off,
 305                                       int invert);
 306 extern void led_trigger_set_default(struct led_classdev *led_cdev);
 307 extern int led_trigger_set(struct led_classdev *led_cdev,
 308                            struct led_trigger *trigger);
 309 extern void led_trigger_remove(struct led_classdev *led_cdev);
 310
 311 static inline void led_set_trigger_data(struct led_classdev *led_cdev,
 312                                         void *trigger_data)
 313 {
 314         led_cdev->trigger_data = trigger_data;
 315 }
 316
 317 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 318 {
 319         return led_cdev->trigger_data;
 320 }
 321
 322 /**
 323  * led_trigger_rename_static - rename a trigger
 324  * @name: the new trigger name
 325  * @trig: the LED trigger to rename
 326  *
 327  * Change a LED trigger name by copying the string passed in
 328  * name into current trigger name, which MUST be large
 329  * enough for the new string.
 330  *
 331  * Note that name must NOT point to the same string used
 332  * during LED registration, as that could lead to races.
 333  *
 334  * This is meant to be used on triggers with statically
 335  * allocated name.
 336  */
 337 extern void led_trigger_rename_static(const char *name,
 338                                       struct led_trigger *trig);
 339
 340 #define module_led_trigger(__led_trigger) \
 341         module_driver(__led_trigger, led_trigger_register, \
 342                       led_trigger_unregister)
 343
 344 #else
 345
 346 /* Trigger has no members */
 347 struct led_trigger {};
 348
 349 /* Trigger inline empty functions */
 350 static inline void led_trigger_register_simple(const char *name,
 351                                         struct led_trigger **trigger) {}
 352 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 353 static inline void led_trigger_event(struct led_trigger *trigger,
 354                                 enum led_brightness event) {}
 355 static inline void led_trigger_blink(struct led_trigger *trigger,
 356                                       unsigned long *delay_on,
 357                                       unsigned long *delay_off) {}
 358 static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 359                                       unsigned long *delay_on,
 360                                       unsigned long *delay_off,
 361                                       int invert) {}
 362 static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 363 static inline int led_trigger_set(struct led_classdev *led_cdev,
 364                                   struct led_trigger *trigger)
 365 {
 366         return 0;
 367 }
 368
 369 static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 370 static inline void led_set_trigger_data(struct led_classdev *led_cdev) {}
 371 static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 372 {
 373         return NULL;
 374 }
 375
 376 #endif /* CONFIG_LEDS_TRIGGERS */
 377
 378 /* Trigger specific functions */
 379 #ifdef CONFIG_LEDS_TRIGGER_DISK
 380 extern void ledtrig_disk_activity(bool write);
 381 #else
 382 static inline void ledtrig_disk_activity(bool write) {}
 383 #endif
 384
 385 #ifdef CONFIG_LEDS_TRIGGER_MTD
 386 extern void ledtrig_mtd_activity(void);
 387 #else
 388 static inline void ledtrig_mtd_activity(void) {}
 389 #endif
 390
 391 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 392 extern void ledtrig_flash_ctrl(bool on);
 393 extern void ledtrig_torch_ctrl(bool on);
 394 #else
 395 static inline void ledtrig_flash_ctrl(bool on) {}
 396 static inline void ledtrig_torch_ctrl(bool on) {}
 397 #endif
 398
 399 /*
 400  * Generic LED platform data for describing LED names and default triggers.
 401  */
 402 struct led_info {
 403         const char      *name;
 404         const char      *default_trigger;
 405         int             flags;
 406 };
 407
 408 struct led_platform_data {
 409         int             num_leds;
 410         struct led_info *leds;
 411 };
 412
 413 struct gpio_desc;
 414 typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 415                                 unsigned long *delay_on,
 416                                 unsigned long *delay_off);
 417
 418 /* For the leds-gpio driver */
 419 struct gpio_led {
 420         const char *name;
 421         const char *default_trigger;
 422         unsigned        gpio;
 423         unsigned        active_low : 1;
 424         unsigned        retain_state_suspended : 1;
 425         unsigned        panic_indicator : 1;
 426         unsigned        default_state : 2;
 427         unsigned        retain_state_shutdown : 1;
 428         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 429         struct gpio_desc *gpiod;
 430 };
 431 #define LEDS_GPIO_DEFSTATE_OFF          0
 432 #define LEDS_GPIO_DEFSTATE_ON           1
 433 #define LEDS_GPIO_DEFSTATE_KEEP         2
 434
 435 struct gpio_led_platform_data {
 436         int             num_leds;
 437         const struct gpio_led *leds;
 438
 439 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 440 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 441 #define GPIO_LED_BLINK          2       /* Please, blink */
 442         gpio_blink_set_t        gpio_blink_set;
 443 };
 444
 445 #ifdef CONFIG_NEW_LEDS
 446 struct platform_device *gpio_led_register_device(
 447                 int id, const struct gpio_led_platform_data *pdata);
 448 #else
 449 static inline struct platform_device *gpio_led_register_device(
 450                 int id, const struct gpio_led_platform_data *pdata)
 451 {
 452         return 0;
 453 }
 454 #endif
 455
 456 enum cpu_led_event {
 457         CPU_LED_IDLE_START,     /* CPU enters idle */
 458         CPU_LED_IDLE_END,       /* CPU idle ends */
 459         CPU_LED_START,          /* Machine starts, especially resume */
 460         CPU_LED_STOP,           /* Machine stops, especially suspend */
 461         CPU_LED_HALTED,         /* Machine shutdown */
 462 };
 463 #ifdef CONFIG_LEDS_TRIGGER_CPU
 464 extern void ledtrig_cpu(enum cpu_led_event evt);
 465 #else
 466 static inline void ledtrig_cpu(enum cpu_led_event evt)
 467 {
 468         return;
 469 }
 470 #endif
 471
 472 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 473 extern void led_classdev_notify_brightness_hw_changed(
 474         struct led_classdev *led_cdev, enum led_brightness brightness);
 475 #else
 476 static inline void led_classdev_notify_brightness_hw_changed(
 477         struct led_classdev *led_cdev, enum led_brightness brightness) { }
 478 #endif
 479
 480 /**
 481  * struct led_pattern - pattern interval settings
 482  * @delta_t: pattern interval delay, in milliseconds
 483  * @brightness: pattern interval brightness
 484  */
 485 struct led_pattern {
 486         u32 delta_t;
 487         int brightness;
 488 };
 489
 490 #endif          /* __LINUX_LEDS_H_INCLUDED */