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