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