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