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