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