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/spinlock.h>
  17 #include <linux/rwsem.h>
  18 #include <linux/timer.h>
  19
  20 struct device;
  21 /*
  22  * LED Core
  23  */
  24
  25 enum led_brightness {
  26         LED_OFF         = 0,
  27         LED_HALF        = 127,
  28         LED_FULL        = 255,
  29 };
  30
  31 struct led_classdev {
  32         const char              *name;
  33         int                      brightness;
  34         int                      max_brightness;
  35         int                      flags;
  36
  37         /* Lower 16 bits reflect status */
  38 #define LED_SUSPENDED           (1 << 0)
  39         /* Upper 16 bits reflect control information */
  40 #define LED_CORE_SUSPENDRESUME  (1 << 16)
  41 #define LED_BLINK_ONESHOT       (1 << 17)
  42 #define LED_BLINK_ONESHOT_STOP  (1 << 18)
  43 #define LED_BLINK_INVERT        (1 << 19)
  44
  45         /* Set LED brightness level */
  46         /* Must not sleep, use a workqueue if needed */
  47         void            (*brightness_set)(struct led_classdev *led_cdev,
  48                                           enum led_brightness brightness);
  49         /* Get LED brightness level */
  50         enum led_brightness (*brightness_get)(struct led_classdev *led_cdev);
  51
  52         /*
  53          * Activate hardware accelerated blink, delays are in milliseconds
  54          * and if both are zero then a sensible default should be chosen.
  55          * The call should adjust the timings in that case and if it can't
  56          * match the values specified exactly.
  57          * Deactivate blinking again when the brightness is set to a fixed
  58          * value via the brightness_set() callback.
  59          */
  60         int             (*blink_set)(struct led_classdev *led_cdev,
  61                                      unsigned long *delay_on,
  62                                      unsigned long *delay_off);
  63
  64         struct device           *dev;
  65         struct list_head         node;                  /* LED Device list */
  66         const char              *default_trigger;       /* Trigger to use */
  67
  68         unsigned long            blink_delay_on, blink_delay_off;
  69         struct timer_list        blink_timer;
  70         int                      blink_brightness;
  71
  72 #ifdef CONFIG_LEDS_TRIGGERS
  73         /* Protects the trigger data below */
  74         struct rw_semaphore      trigger_lock;
  75
  76         struct led_trigger      *trigger;
  77         struct list_head         trig_list;
  78         void                    *trigger_data;
  79         /* true if activated - deactivate routine uses it to do cleanup */
  80         bool                    activated;
  81 #endif
  82 };
  83
  84 extern int led_classdev_register(struct device *parent,
  85                                  struct led_classdev *led_cdev);
  86 extern void led_classdev_unregister(struct led_classdev *led_cdev);
  87 extern void led_classdev_suspend(struct led_classdev *led_cdev);
  88 extern void led_classdev_resume(struct led_classdev *led_cdev);
  89
  90 /**
  91  * led_blink_set - set blinking with software fallback
  92  * @led_cdev: the LED to start blinking
  93  * @delay_on: the time it should be on (in ms)
  94  * @delay_off: the time it should ble off (in ms)
  95  *
  96  * This function makes the LED blink, attempting to use the
  97  * hardware acceleration if possible, but falling back to
  98  * software blinking if there is no hardware blinking or if
  99  * the LED refuses the passed values.
 100  *
 101  * Note that if software blinking is active, simply calling
 102  * led_cdev->brightness_set() will not stop the blinking,
 103  * use led_classdev_brightness_set() instead.
 104  */
 105 extern void led_blink_set(struct led_classdev *led_cdev,
 106                           unsigned long *delay_on,
 107                           unsigned long *delay_off);
 108 /**
 109  * led_blink_set_oneshot - do a oneshot software blink
 110  * @led_cdev: the LED to start blinking
 111  * @delay_on: the time it should be on (in ms)
 112  * @delay_off: the time it should ble off (in ms)
 113  * @invert: blink off, then on, leaving the led on
 114  *
 115  * This function makes the LED blink one time for delay_on +
 116  * delay_off time, ignoring the request if another one-shot
 117  * blink is already in progress.
 118  *
 119  * If invert is set, led blinks for delay_off first, then for
 120  * delay_on and leave the led on after the on-off cycle.
 121  */
 122 extern void led_blink_set_oneshot(struct led_classdev *led_cdev,
 123                                   unsigned long *delay_on,
 124                                   unsigned long *delay_off,
 125                                   int invert);
 126 /**
 127  * led_set_brightness - set LED brightness
 128  * @led_cdev: the LED to set
 129  * @brightness: the brightness to set it to
 130  *
 131  * Set an LED's brightness, and, if necessary, cancel the
 132  * software blink timer that implements blinking when the
 133  * hardware doesn't.
 134  */
 135 extern void led_set_brightness(struct led_classdev *led_cdev,
 136                                enum led_brightness brightness);
 137
 138 /*
 139  * LED Triggers
 140  */
 141 #ifdef CONFIG_LEDS_TRIGGERS
 142
 143 #define TRIG_NAME_MAX 50
 144
 145 struct led_trigger {
 146         /* Trigger Properties */
 147         const char       *name;
 148         void            (*activate)(struct led_classdev *led_cdev);
 149         void            (*deactivate)(struct led_classdev *led_cdev);
 150
 151         /* LEDs under control by this trigger (for simple triggers) */
 152         rwlock_t          leddev_list_lock;
 153         struct list_head  led_cdevs;
 154
 155         /* Link to next registered trigger */
 156         struct list_head  next_trig;
 157 };
 158
 159 /* Registration functions for complex triggers */
 160 extern int led_trigger_register(struct led_trigger *trigger);
 161 extern void led_trigger_unregister(struct led_trigger *trigger);
 162
 163 /* Registration functions for simple triggers */
 164 #define DEFINE_LED_TRIGGER(x)           static struct led_trigger *x;
 165 #define DEFINE_LED_TRIGGER_GLOBAL(x)    struct led_trigger *x;
 166 extern void led_trigger_register_simple(const char *name,
 167                                 struct led_trigger **trigger);
 168 extern void led_trigger_unregister_simple(struct led_trigger *trigger);
 169 extern void led_trigger_event(struct led_trigger *trigger,
 170                                 enum led_brightness event);
 171 extern void led_trigger_blink(struct led_trigger *trigger,
 172                               unsigned long *delay_on,
 173                               unsigned long *delay_off);
 174 extern void led_trigger_blink_oneshot(struct led_trigger *trigger,
 175                                       unsigned long *delay_on,
 176                                       unsigned long *delay_off,
 177                                       int invert);
 178
 179 #else
 180
 181 /* Triggers aren't active - null macros */
 182 #define DEFINE_LED_TRIGGER(x)
 183 #define DEFINE_LED_TRIGGER_GLOBAL(x)
 184 #define led_trigger_register_simple(x, y) do {} while(0)
 185 #define led_trigger_unregister_simple(x) do {} while(0)
 186 #define led_trigger_event(x, y) do {} while(0)
 187
 188 #endif
 189
 190 /* Trigger specific functions */
 191 #ifdef CONFIG_LEDS_TRIGGER_IDE_DISK
 192 extern void ledtrig_ide_activity(void);
 193 #else
 194 #define ledtrig_ide_activity() do {} while(0)
 195 #endif
 196
 197 /*
 198  * Generic LED platform data for describing LED names and default triggers.
 199  */
 200 struct led_info {
 201         const char      *name;
 202         const char      *default_trigger;
 203         int             flags;
 204 };
 205
 206 struct led_platform_data {
 207         int             num_leds;
 208         struct led_info *leds;
 209 };
 210
 211 /* For the leds-gpio driver */
 212 struct gpio_led {
 213         const char *name;
 214         const char *default_trigger;
 215         unsigned        gpio;
 216         unsigned        active_low : 1;
 217         unsigned        retain_state_suspended : 1;
 218         unsigned        default_state : 2;
 219         /* default_state should be one of LEDS_GPIO_DEFSTATE_(ON|OFF|KEEP) */
 220 };
 221 #define LEDS_GPIO_DEFSTATE_OFF          0
 222 #define LEDS_GPIO_DEFSTATE_ON           1
 223 #define LEDS_GPIO_DEFSTATE_KEEP         2
 224
 225 struct gpio_led_platform_data {
 226         int             num_leds;
 227         const struct gpio_led *leds;
 228
 229 #define GPIO_LED_NO_BLINK_LOW   0       /* No blink GPIO state low */
 230 #define GPIO_LED_NO_BLINK_HIGH  1       /* No blink GPIO state high */
 231 #define GPIO_LED_BLINK          2       /* Please, blink */
 232         int             (*gpio_blink_set)(unsigned gpio, int state,
 233                                         unsigned long *delay_on,
 234                                         unsigned long *delay_off);
 235 };
 236
 237 struct platform_device *gpio_led_register_device(
 238                 int id, const struct gpio_led_platform_data *pdata);
 239
 240 #endif          /* __LINUX_LEDS_H_INCLUDED */