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 #define LED_DEV_CAP_SYNC_STROBE (1 << 24)
  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_sync)(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 void led_classdev_unregister(struct led_classdev *led_cdev);
 109 extern void led_classdev_suspend(struct led_classdev *led_cdev);
 110 extern void led_classdev_resume(struct led_classdev *led_cdev);
 111
 112 /**
 113  * led_blink_set - set blinking with software fallback
 114  * @led_cdev: the LED to start blinking
 115  * @delay_on: the time it should be on (in ms)
 116  * @delay_off: the time it should ble off (in ms)
 117  *
 118  * This function makes the LED blink, attempting to use the
 119  * hardware acceleration if possible, but falling back to
 120  * software blinking if there is no hardware blinking or if
 121  * the LED refuses the passed values.
 122  *
 123  * Note that if software blinking is active, simply calling
 124  * led_cdev->brightness_set() will not stop the blinking,
 125  * use led_classdev_brightness_set() instead.
 126  */
 127 extern void led_blink_set(struct led_classdev *led_cdev,
 128                           unsigned long *delay_on,
 129                           unsigned long *delay_off);
 130 /**
 131  * led_blink_set_oneshot - do a oneshot software blink
 132  * @led_cdev: the LED to start blinking
 133  * @delay_on: the time it should be on (in ms)
 134  * @delay_off: the time it should ble off (in ms)
 135  * @invert: blink off, then on, leaving the led on
 136  *
 137  * This function makes the LED blink one time for delay_on +
 138  * delay_off time, ignoring the request if another one-shot
 139  * blink is already in progress.
 140  *
 141  * If invert is set, led blinks for delay_off first, then for
 142  * delay_on and leave the led on after the on-off cycle.
 143  */
 144 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 145                                   unsigned long *delay_on,
 146                                   unsigned long *delay_off,
 147                                   int invert);
 148 /**
 149  * led_set_brightness - set LED brightness
 150  * @led_cdev: the LED to set
 151  * @brightness: the brightness to set it to
 152  *
 153  * Set an LED's brightness, and, if necessary, cancel the
 154  * software blink timer that implements blinking when the
 155  * hardware doesn't.
 156  */
 157 extern void led_set_brightness(struct led_classdev *led_cdev,
 158                                enum led_brightness brightness);
 159 /**
 160  * led_update_brightness - update LED brightness
 161  * @led_cdev: the LED to query
 162  *
 163  * Get an LED's current brightness and update led_cdev->brightness
 164  * member with the obtained value.
 165  *
 166  * Returns: 0 on success or negative error value on failure
 167  */
 168 extern int led_update_brightness(struct led_classdev *led_cdev);
 169
 170 /**
 171  * led_sysfs_disable - disable LED sysfs interface
 172  * @led_cdev: the LED to set
 173  *
 174  * Disable the led_cdev's sysfs interface.
 175  */
 176 extern void led_sysfs_disable(struct led_classdev *led_cdev);
 177
 178 /**
 179  * led_sysfs_enable - enable LED sysfs interface
 180  * @led_cdev: the LED to set
 181  *
 182  * Enable the led_cdev's sysfs interface.
 183  */
 184 extern void led_sysfs_enable(struct led_classdev *led_cdev);
 185
 186 /**
 187  * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 188  * @led_cdev: the LED to query
 189  *
 190  * Returns: true if the led_cdev's sysfs interface is disabled.
 191  */
 192 static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 193 {
 194         return led_cdev->flags & LED_SYSFS_DISABLE;
 195 }
 196
 197 /*
 198  * LED Triggers
 199  */
 200 /* Registration functions for simple triggers */
 201 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 202 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 203
 204 #ifdef CONFIG_LEDS_TRIGGERS
 205
 206 #define TRIG_NAME_MAX 50
 207
 208 struct led_trigger {
 209         /* Trigger Properties */
 210         const char       *name;
 211         void            (*activate)(struct led_classdev *led_cdev);
 212         void            (*deactivate)(struct led_classdev *led_cdev);
 213
 214         /* LEDs under control by this trigger (for simple triggers) */
 215         rwlock_t          leddev_list_lock;
 216         struct list_head  led_cdevs;
 217
 218         /* Link to next registered trigger */
 219         struct list_head  next_trig;
 220 };
 221
 222 /* Registration functions for complex triggers */
 223 extern int led_trigger_register(struct led_trigger *trigger);
 224 extern void led_trigger_unregister(struct led_trigger *trigger);
 225
 226 extern void led_trigger_register_simple(const char *name,
 227                                 struct led_trigger **trigger);
 228 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 229 extern void led_trigger_event(struct led_trigger *trigger,
 230                                 enum led_brightness event);
 231 extern void led_trigger_blink(struct led_trigger *trigger,
 232                               unsigned long *delay_on,
 233                               unsigned long *delay_off);
 234 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 235                                       unsigned long *delay_on,
 236                                       unsigned long *delay_off,
 237                                       int invert);
 238 /**
 239  * led_trigger_rename_static - rename a trigger
 240  * @name: the new trigger name
 241  * @trig: the LED trigger to rename
 242  *
 243  * Change a LED trigger name by copying the string passed in
 244  * name into current trigger name, which MUST be large
 245  * enough for the new string.
 246  *
 247  * Note that name must NOT point to the same string used
 248  * during LED registration, as that could lead to races.
 249  *
 250  * This is meant to be used on triggers with statically
 251  * allocated name.
 252  */
 253 extern void led_trigger_rename_static(const char *name,
 254                                       struct led_trigger *trig);
 255
 256 #else
 257
 258 /* Trigger has no members */
 259 struct led_trigger {};
 260
 261 /* Trigger inline empty functions */
 262 static inline void led_trigger_register_simple(const char *name,
 263                                         struct led_trigger **trigger) {}
 264 static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 265 static inline void led_trigger_event(struct led_trigger *trigger,
 266                                 enum led_brightness event) {}
 267 #endif /* CONFIG_LEDS_TRIGGERS */
 268
 269 /* Trigger specific functions */
 270 #ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
 271 extern void ledtrig_ide_activity(void);
 272 #else
 273 static inline void ledtrig_ide_activity(void) {}
 274 #endif
 275
 276 #if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 277 extern void ledtrig_flash_ctrl(bool on);
 278 extern void ledtrig_torch_ctrl(bool on);
 279 #else
 280 static inline void ledtrig_flash_ctrl(bool on) {}
 281 static inline void ledtrig_torch_ctrl(bool on) {}
 282 #endif
 283
 284 /*
 285  * Generic LED platform data for describing LED names and default triggers.
 286  */
 287 struct led_info {
 288         const char      *name;
 289         const char      *default_trigger;
 290         int             flags;
 291 };
 292
 293 struct led_platform_data {
 294         int             num_leds;
 295         struct led_info *leds;
 296 };
 297
 298 /* For the leds-gpio driver */
 299 struct gpio_led {
 300         const char *name;
 301         const char *default_trigger;
 302         unsigned        gpio;
 303         unsigned        active_low : 1;
 304         unsigned        retain_state_suspended : 1;
 305         unsigned        default_state : 2;
 306         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 307         struct gpio_desc *gpiod;
 308 };
 309 #define LEDS_GPIO_DEFSTATE_OFF          0
 310 #define LEDS_GPIO_DEFSTATE_ON           1
 311 #define LEDS_GPIO_DEFSTATE_KEEP         2
 312
 313 struct gpio_led_platform_data {
 314         int             num_leds;
 315         const struct gpio_led *leds;
 316
 317 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 318 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 319 #define GPIO_LED_BLINK          2       /* Please, blink */
 320         int             (*gpio_blink_set)(struct gpio_desc *desc, int state,
 321                                         unsigned long *delay_on,
 322                                         unsigned long *delay_off);
 323 };
 324
 325 struct platform_device *gpio_led_register_device(
 326                 int id, const struct gpio_led_platform_data *pdata);
 327
 328 enum cpu_led_event {
 329         CPU_LED_IDLE_START,     /* CPU enters idle */
 330         CPU_LED_IDLE_END,       /* CPU idle ends */
 331         CPU_LED_START,          /* Machine starts, especially resume */
 332         CPU_LED_STOP,           /* Machine stops, especially suspend */
 333         CPU_LED_HALTED,         /* Machine shutdown */
 334 };
 335 #ifdef CONFIG_LEDS_TRIGGER_CPU
 336 extern void ledtrig_cpu(enum cpu_led_event evt);
 337 #else
 338 static inline void ledtrig_cpu(enum cpu_led_event evt)
 339 {
 340         return;
 341 }
 342 #endif
 343
 344 #endif          /* __LINUX_LEDS_H_INCLUDED */