linux/include/linux/leds.h
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   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
  23struct device;
  24/*
  25 * LED Core
  26 */
  27
  28enum led_brightness {
  29        LED_OFF         = 0,
  30        LED_HALF        = 127,
  31        LED_FULL        = 255,
  32};
  33
  34struct 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_SYSFS_DISABLE       (1 << 20)
  48#define SET_BRIGHTNESS_ASYNC    (1 << 21)
  49#define SET_BRIGHTNESS_SYNC     (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_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
 106extern int led_classdev_register(struct device *parent,
 107                                 struct led_classdev *led_cdev);
 108extern int devm_led_classdev_register(struct device *parent,
 109                                      struct led_classdev *led_cdev);
 110extern void led_classdev_unregister(struct led_classdev *led_cdev);
 111extern void devm_led_classdev_unregister(struct device *parent,
 112                                         struct led_classdev *led_cdev);
 113extern void led_classdev_suspend(struct led_classdev *led_cdev);
 114extern 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 */
 131extern 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 */
 148extern 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.
 160 */
 161extern void led_set_brightness(struct led_classdev *led_cdev,
 162                               enum led_brightness brightness);
 163/**
 164 * led_update_brightness - update LED brightness
 165 * @led_cdev: the LED to query
 166 *
 167 * Get an LED's current brightness and update led_cdev->brightness
 168 * member with the obtained value.
 169 *
 170 * Returns: 0 on success or negative error value on failure
 171 */
 172extern int led_update_brightness(struct led_classdev *led_cdev);
 173
 174/**
 175 * led_sysfs_disable - disable LED sysfs interface
 176 * @led_cdev: the LED to set
 177 *
 178 * Disable the led_cdev's sysfs interface.
 179 */
 180extern void led_sysfs_disable(struct led_classdev *led_cdev);
 181
 182/**
 183 * led_sysfs_enable - enable LED sysfs interface
 184 * @led_cdev: the LED to set
 185 *
 186 * Enable the led_cdev's sysfs interface.
 187 */
 188extern void led_sysfs_enable(struct led_classdev *led_cdev);
 189
 190/**
 191 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 192 * @led_cdev: the LED to query
 193 *
 194 * Returns: true if the led_cdev's sysfs interface is disabled.
 195 */
 196static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 197{
 198        return led_cdev->flags & LED_SYSFS_DISABLE;
 199}
 200
 201/*
 202 * LED Triggers
 203 */
 204/* Registration functions for simple triggers */
 205#define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 206#define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 207
 208#ifdef CONFIG_LEDS_TRIGGERS
 209
 210#define TRIG_NAME_MAX 50
 211
 212struct led_trigger {
 213        /* Trigger Properties */
 214        const char       *name;
 215        void            (*activate)(struct led_classdev *led_cdev);
 216        void            (*deactivate)(struct led_classdev *led_cdev);
 217
 218        /* LEDs under control by this trigger (for simple triggers) */
 219        rwlock_t          leddev_list_lock;
 220        struct list_head  led_cdevs;
 221
 222        /* Link to next registered trigger */
 223        struct list_head  next_trig;
 224};
 225
 226ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 227                        const char *buf, size_t count);
 228ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 229                        char *buf);
 230
 231/* Registration functions for complex triggers */
 232extern int led_trigger_register(struct led_trigger *trigger);
 233extern void led_trigger_unregister(struct led_trigger *trigger);
 234
 235extern void led_trigger_register_simple(const char *name,
 236                                struct led_trigger **trigger);
 237extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 238extern void led_trigger_event(struct led_trigger *trigger,
 239                                enum led_brightness event);
 240extern void led_trigger_blink(struct led_trigger *trigger,
 241                              unsigned long *delay_on,
 242                              unsigned long *delay_off);
 243extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 244                                      unsigned long *delay_on,
 245                                      unsigned long *delay_off,
 246                                      int invert);
 247extern void led_trigger_set_default(struct led_classdev *led_cdev);
 248extern void led_trigger_set(struct led_classdev *led_cdev,
 249                        struct led_trigger *trigger);
 250extern void led_trigger_remove(struct led_classdev *led_cdev);
 251
 252static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 253{
 254        return led_cdev->trigger_data;
 255}
 256
 257/**
 258 * led_trigger_rename_static - rename a trigger
 259 * @name: the new trigger name
 260 * @trig: the LED trigger to rename
 261 *
 262 * Change a LED trigger name by copying the string passed in
 263 * name into current trigger name, which MUST be large
 264 * enough for the new string.
 265 *
 266 * Note that name must NOT point to the same string used
 267 * during LED registration, as that could lead to races.
 268 *
 269 * This is meant to be used on triggers with statically
 270 * allocated name.
 271 */
 272extern void led_trigger_rename_static(const char *name,
 273                                      struct led_trigger *trig);
 274
 275#else
 276
 277/* Trigger has no members */
 278struct led_trigger {};
 279
 280/* Trigger inline empty functions */
 281static inline void led_trigger_register_simple(const char *name,
 282                                        struct led_trigger **trigger) {}
 283static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 284static inline void led_trigger_event(struct led_trigger *trigger,
 285                                enum led_brightness event) {}
 286static inline void led_trigger_blink(struct led_trigger *trigger,
 287                                      unsigned long *delay_on,
 288                                      unsigned long *delay_off) {}
 289static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 290                                      unsigned long *delay_on,
 291                                      unsigned long *delay_off,
 292                                      int invert) {}
 293static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 294static inline void led_trigger_set(struct led_classdev *led_cdev,
 295                                struct led_trigger *trigger) {}
 296static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 297static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 298{
 299        return NULL;
 300}
 301
 302#endif /* CONFIG_LEDS_TRIGGERS */
 303
 304/* Trigger specific functions */
 305#ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
 306extern void ledtrig_ide_activity(void);
 307#else
 308static inline void ledtrig_ide_activity(void) {}
 309#endif
 310
 311#if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 312extern void ledtrig_flash_ctrl(bool on);
 313extern void ledtrig_torch_ctrl(bool on);
 314#else
 315static inline void ledtrig_flash_ctrl(bool on) {}
 316static inline void ledtrig_torch_ctrl(bool on) {}
 317#endif
 318
 319/*
 320 * Generic LED platform data for describing LED names and default triggers.
 321 */
 322struct led_info {
 323        const char      *name;
 324        const char      *default_trigger;
 325        int             flags;
 326};
 327
 328struct led_platform_data {
 329        int             num_leds;
 330        struct led_info *leds;
 331};
 332
 333/* For the leds-gpio driver */
 334struct gpio_led {
 335        const char *name;
 336        const char *default_trigger;
 337        unsigned        gpio;
 338        unsigned        active_low : 1;
 339        unsigned        retain_state_suspended : 1;
 340        unsigned        default_state : 2;
 341        /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 342        struct gpio_desc *gpiod;
 343};
 344#define LEDS_GPIO_DEFSTATE_OFF          0
 345#define LEDS_GPIO_DEFSTATE_ON           1
 346#define LEDS_GPIO_DEFSTATE_KEEP         2
 347
 348struct gpio_led_platform_data {
 349        int             num_leds;
 350        const struct gpio_led *leds;
 351
 352#define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 353#define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 354#define GPIO_LED_BLINK          2       /* Please, blink */
 355        int             (*gpio_blink_set)(struct gpio_desc *desc, int state,
 356                                        unsigned long *delay_on,
 357                                        unsigned long *delay_off);
 358};
 359
 360struct platform_device *gpio_led_register_device(
 361                int id, const struct gpio_led_platform_data *pdata);
 362
 363enum cpu_led_event {
 364        CPU_LED_IDLE_START,     /* CPU enters idle */
 365        CPU_LED_IDLE_END,       /* CPU idle ends */
 366        CPU_LED_START,          /* Machine starts, especially resume */
 367        CPU_LED_STOP,           /* Machine stops, especially suspend */
 368        CPU_LED_HALTED,         /* Machine shutdown */
 369};
 370#ifdef CONFIG_LEDS_TRIGGER_CPU
 371extern void ledtrig_cpu(enum cpu_led_event evt);
 372#else
 373static inline void ledtrig_cpu(enum cpu_led_event evt)
 374{
 375        return;
 376}
 377#endif
 378
 379#endif          /* __LINUX_LEDS_H_INCLUDED */
 380