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