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