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