linux/include/linux/leds.h
<<
>>
Prefs
   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#define LED_UNREGISTERING       (1 << 1)
  43        /* Upper 16 bits reflect control information */
  44#define LED_CORE_SUSPENDRESUME  (1 << 16)
  45#define LED_BLINK_SW            (1 << 17)
  46#define LED_BLINK_ONESHOT       (1 << 18)
  47#define LED_BLINK_ONESHOT_STOP  (1 << 19)
  48#define LED_BLINK_INVERT        (1 << 20)
  49#define LED_BLINK_BRIGHTNESS_CHANGE (1 << 21)
  50#define LED_BLINK_DISABLE       (1 << 22)
  51#define LED_SYSFS_DISABLE       (1 << 23)
  52#define LED_DEV_CAP_FLASH       (1 << 24)
  53#define LED_HW_PLUGGABLE        (1 << 25)
  54#define LED_PANIC_INDICATOR     (1 << 26)
  55
  56        /* Set LED brightness level
  57         * Must not sleep. Use brightness_set_blocking for drivers
  58         * that can sleep while setting brightness.
  59         */
  60        void            (*brightness_set)(struct led_classdev *led_cdev,
  61                                          enum led_brightness brightness);
  62        /*
  63         * Set LED brightness level immediately - it can block the caller for
  64         * the time required for accessing a LED device register.
  65         */
  66        int (*brightness_set_blocking)(struct led_classdev *led_cdev,
  67                                       enum led_brightness brightness);
  68        /* Get LED brightness level */
  69        enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  70
  71        /*
  72         * Activate hardware accelerated blink, delays are in milliseconds
  73         * and if both are zero then a sensible default should be chosen.
  74         * The call should adjust the timings in that case and if it can't
  75         * match the values specified exactly.
  76         * Deactivate blinking again when the brightness is set to LED_OFF
  77         * via the brightness_set() callback.
  78         */
  79        int             (*blink_set)(struct led_classdev *led_cdev,
  80                                     unsigned long *delay_on,
  81                                     unsigned long *delay_off);
  82
  83        struct device           *dev;
  84        const struct attribute_group    **groups;
  85
  86        struct list_head         node;                  /* LED Device list */
  87        const char              *default_trigger;       /* Trigger to use */
  88
  89        unsigned long            blink_delay_on, blink_delay_off;
  90        struct timer_list        blink_timer;
  91        int                      blink_brightness;
  92        void                    (*flash_resume)(struct led_classdev *led_cdev);
  93
  94        struct work_struct      set_brightness_work;
  95        int                     delayed_set_value;
  96
  97#ifdef CONFIG_LEDS_TRIGGERS
  98        /* Protects the trigger data below */
  99        struct rw_semaphore      trigger_lock;
 100
 101        struct led_trigger      *trigger;
 102        struct list_head         trig_list;
 103        void                    *trigger_data;
 104        /* true if activated - deactivate routine uses it to do cleanup */
 105        bool                    activated;
 106#endif
 107
 108        /* Ensures consistent access to the LED Flash Class device */
 109        struct mutex            led_access;
 110};
 111
 112extern int led_classdev_register(struct device *parent,
 113                                 struct led_classdev *led_cdev);
 114extern int devm_led_classdev_register(struct device *parent,
 115                                      struct led_classdev *led_cdev);
 116extern void led_classdev_unregister(struct led_classdev *led_cdev);
 117extern void devm_led_classdev_unregister(struct device *parent,
 118                                         struct led_classdev *led_cdev);
 119extern void led_classdev_suspend(struct led_classdev *led_cdev);
 120extern void led_classdev_resume(struct led_classdev *led_cdev);
 121
 122/**
 123 * led_blink_set - set blinking with software fallback
 124 * @led_cdev: the LED to start blinking
 125 * @delay_on: the time it should be on (in ms)
 126 * @delay_off: the time it should ble off (in ms)
 127 *
 128 * This function makes the LED blink, attempting to use the
 129 * hardware acceleration if possible, but falling back to
 130 * software blinking if there is no hardware blinking or if
 131 * the LED refuses the passed values.
 132 *
 133 * Note that if software blinking is active, simply calling
 134 * led_cdev->brightness_set() will not stop the blinking,
 135 * use led_classdev_brightness_set() instead.
 136 */
 137extern void led_blink_set(struct led_classdev *led_cdev,
 138                          unsigned long *delay_on,
 139                          unsigned long *delay_off);
 140/**
 141 * led_blink_set_oneshot - do a oneshot software blink
 142 * @led_cdev: the LED to start blinking
 143 * @delay_on: the time it should be on (in ms)
 144 * @delay_off: the time it should ble off (in ms)
 145 * @invert: blink off, then on, leaving the led on
 146 *
 147 * This function makes the LED blink one time for delay_on +
 148 * delay_off time, ignoring the request if another one-shot
 149 * blink is already in progress.
 150 *
 151 * If invert is set, led blinks for delay_off first, then for
 152 * delay_on and leave the led on after the on-off cycle.
 153 */
 154extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 155                                  unsigned long *delay_on,
 156                                  unsigned long *delay_off,
 157                                  int invert);
 158/**
 159 * led_set_brightness - set LED brightness
 160 * @led_cdev: the LED to set
 161 * @brightness: the brightness to set it to
 162 *
 163 * Set an LED's brightness, and, if necessary, cancel the
 164 * software blink timer that implements blinking when the
 165 * hardware doesn't. This function is guaranteed not to sleep.
 166 */
 167extern void led_set_brightness(struct led_classdev *led_cdev,
 168                               enum led_brightness brightness);
 169
 170/**
 171 * led_set_brightness_sync - set LED brightness synchronously
 172 * @led_cdev: the LED to set
 173 * @brightness: the brightness to set it to
 174 *
 175 * Set an LED's brightness immediately. This function will block
 176 * the caller for the time required for accessing device registers,
 177 * and it can sleep.
 178 *
 179 * Returns: 0 on success or negative error value on failure
 180 */
 181extern int led_set_brightness_sync(struct led_classdev *led_cdev,
 182                                   enum led_brightness value);
 183
 184/**
 185 * led_update_brightness - update LED brightness
 186 * @led_cdev: the LED to query
 187 *
 188 * Get an LED's current brightness and update led_cdev->brightness
 189 * member with the obtained value.
 190 *
 191 * Returns: 0 on success or negative error value on failure
 192 */
 193extern int led_update_brightness(struct led_classdev *led_cdev);
 194
 195/**
 196 * led_sysfs_disable - disable LED sysfs interface
 197 * @led_cdev: the LED to set
 198 *
 199 * Disable the led_cdev's sysfs interface.
 200 */
 201extern void led_sysfs_disable(struct led_classdev *led_cdev);
 202
 203/**
 204 * led_sysfs_enable - enable LED sysfs interface
 205 * @led_cdev: the LED to set
 206 *
 207 * Enable the led_cdev's sysfs interface.
 208 */
 209extern void led_sysfs_enable(struct led_classdev *led_cdev);
 210
 211/**
 212 * led_sysfs_is_disabled - check if LED sysfs interface is disabled
 213 * @led_cdev: the LED to query
 214 *
 215 * Returns: true if the led_cdev's sysfs interface is disabled.
 216 */
 217static inline bool led_sysfs_is_disabled(struct led_classdev *led_cdev)
 218{
 219        return led_cdev->flags & LED_SYSFS_DISABLE;
 220}
 221
 222/*
 223 * LED Triggers
 224 */
 225/* Registration functions for simple triggers */
 226#define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 227#define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 228
 229#ifdef CONFIG_LEDS_TRIGGERS
 230
 231#define TRIG_NAME_MAX 50
 232
 233struct led_trigger {
 234        /* Trigger Properties */
 235        const char       *name;
 236        void            (*activate)(struct led_classdev *led_cdev);
 237        void            (*deactivate)(struct led_classdev *led_cdev);
 238
 239        /* LEDs under control by this trigger (for simple triggers) */
 240        rwlock_t          leddev_list_lock;
 241        struct list_head  led_cdevs;
 242
 243        /* Link to next registered trigger */
 244        struct list_head  next_trig;
 245};
 246
 247ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
 248                        const char *buf, size_t count);
 249ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
 250                        char *buf);
 251
 252/* Registration functions for complex triggers */
 253extern int led_trigger_register(struct led_trigger *trigger);
 254extern void led_trigger_unregister(struct led_trigger *trigger);
 255extern int devm_led_trigger_register(struct device *dev,
 256                                     struct led_trigger *trigger);
 257
 258extern void led_trigger_register_simple(const char *name,
 259                                struct led_trigger **trigger);
 260extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 261extern void led_trigger_event(struct led_trigger *trigger,
 262                                enum led_brightness event);
 263extern void led_trigger_blink(struct led_trigger *trigger,
 264                              unsigned long *delay_on,
 265                              unsigned long *delay_off);
 266extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 267                                      unsigned long *delay_on,
 268                                      unsigned long *delay_off,
 269                                      int invert);
 270extern void led_trigger_set_default(struct led_classdev *led_cdev);
 271extern void led_trigger_set(struct led_classdev *led_cdev,
 272                        struct led_trigger *trigger);
 273extern void led_trigger_remove(struct led_classdev *led_cdev);
 274
 275static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 276{
 277        return led_cdev->trigger_data;
 278}
 279
 280/**
 281 * led_trigger_rename_static - rename a trigger
 282 * @name: the new trigger name
 283 * @trig: the LED trigger to rename
 284 *
 285 * Change a LED trigger name by copying the string passed in
 286 * name into current trigger name, which MUST be large
 287 * enough for the new string.
 288 *
 289 * Note that name must NOT point to the same string used
 290 * during LED registration, as that could lead to races.
 291 *
 292 * This is meant to be used on triggers with statically
 293 * allocated name.
 294 */
 295extern void led_trigger_rename_static(const char *name,
 296                                      struct led_trigger *trig);
 297
 298#else
 299
 300/* Trigger has no members */
 301struct led_trigger {};
 302
 303/* Trigger inline empty functions */
 304static inline void led_trigger_register_simple(const char *name,
 305                                        struct led_trigger **trigger) {}
 306static inline void led_trigger_unregister_simple(struct led_trigger *trigger) {}
 307static inline void led_trigger_event(struct led_trigger *trigger,
 308                                enum led_brightness event) {}
 309static inline void led_trigger_blink(struct led_trigger *trigger,
 310                                      unsigned long *delay_on,
 311                                      unsigned long *delay_off) {}
 312static inline void led_trigger_blink_oneshot(struct led_trigger *trigger,
 313                                      unsigned long *delay_on,
 314                                      unsigned long *delay_off,
 315                                      int invert) {}
 316static inline void led_trigger_set_default(struct led_classdev *led_cdev) {}
 317static inline void led_trigger_set(struct led_classdev *led_cdev,
 318                                struct led_trigger *trigger) {}
 319static inline void led_trigger_remove(struct led_classdev *led_cdev) {}
 320static inline void *led_get_trigger_data(struct led_classdev *led_cdev)
 321{
 322        return NULL;
 323}
 324
 325#endif /* CONFIG_LEDS_TRIGGERS */
 326
 327/* Trigger specific functions */
 328#ifdef CONFIG_LEDS_TRIGGER_DISK
 329extern void ledtrig_disk_activity(void);
 330#else
 331static inline void ledtrig_disk_activity(void) {}
 332#endif
 333
 334#ifdef CONFIG_LEDS_TRIGGER_MTD
 335extern void ledtrig_mtd_activity(void);
 336#else
 337static inline void ledtrig_mtd_activity(void) {}
 338#endif
 339
 340#if defined(CONFIG_LEDS_TRIGGER_CAMERA) || defined(CONFIG_LEDS_TRIGGER_CAMERA_MODULE)
 341extern void ledtrig_flash_ctrl(bool on);
 342extern void ledtrig_torch_ctrl(bool on);
 343#else
 344static inline void ledtrig_flash_ctrl(bool on) {}
 345static inline void ledtrig_torch_ctrl(bool on) {}
 346#endif
 347
 348/*
 349 * Generic LED platform data for describing LED names and default triggers.
 350 */
 351struct led_info {
 352        const char      *name;
 353        const char      *default_trigger;
 354        int             flags;
 355};
 356
 357struct led_platform_data {
 358        int             num_leds;
 359        struct led_info *leds;
 360};
 361
 362struct gpio_desc;
 363typedef int (*gpio_blink_set_t)(struct gpio_desc *desc, int state,
 364                                unsigned long *delay_on,
 365                                unsigned long *delay_off);
 366
 367/* For the leds-gpio driver */
 368struct gpio_led {
 369        const char *name;
 370        const char *default_trigger;
 371        unsigned        gpio;
 372        unsigned        active_low : 1;
 373        unsigned        retain_state_suspended : 1;
 374        unsigned        panic_indicator : 1;
 375        unsigned        default_state : 2;
 376        /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 377        struct gpio_desc *gpiod;
 378};
 379#define LEDS_GPIO_DEFSTATE_OFF          0
 380#define LEDS_GPIO_DEFSTATE_ON           1
 381#define LEDS_GPIO_DEFSTATE_KEEP         2
 382
 383struct gpio_led_platform_data {
 384        int             num_leds;
 385        const struct gpio_led *leds;
 386
 387#define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 388#define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 389#define GPIO_LED_BLINK          2       /* Please, blink */
 390        gpio_blink_set_t        gpio_blink_set;
 391};
 392
 393#ifdef CONFIG_NEW_LEDS
 394struct platform_device *gpio_led_register_device(
 395                int id, const struct gpio_led_platform_data *pdata);
 396#else
 397static inline struct platform_device *gpio_led_register_device(
 398                int id, const struct gpio_led_platform_data *pdata)
 399{
 400        return 0;
 401}
 402#endif
 403
 404enum cpu_led_event {
 405        CPU_LED_IDLE_START,     /* CPU enters idle */
 406        CPU_LED_IDLE_END,       /* CPU idle ends */
 407        CPU_LED_START,          /* Machine starts, especially resume */
 408        CPU_LED_STOP,           /* Machine stops, especially suspend */
 409        CPU_LED_HALTED,         /* Machine shutdown */
 410};
 411#ifdef CONFIG_LEDS_TRIGGER_CPU
 412extern void ledtrig_cpu(enum cpu_led_event evt);
 413#else
 414static inline void ledtrig_cpu(enum cpu_led_event evt)
 415{
 416        return;
 417}
 418#endif
 419
 420#endif          /* __LINUX_LEDS_H_INCLUDED */
 421