Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
20struct device;
21/*
22 * LED Core
23 */
24
25enum led_brightness {
26 LED_OFF = 0,
27 LED_HALF = 127,
28 LED_FULL = 255,
29};
30
31struct 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
84extern int led_classdev_register(struct device *parent,
85 struct led_classdev *led_cdev);
86extern void led_classdev_unregister(struct led_classdev *led_cdev);
87extern void led_classdev_suspend(struct led_classdev *led_cdev);
88extern 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 */
105extern 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 */
122extern 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 */
135extern 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
145struct 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 */
160extern int led_trigger_register(struct led_trigger *trigger);
161extern 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;
166extern void led_trigger_register_simple(const char *name,
167 struct led_trigger **trigger);
168extern void led_trigger_unregister_simple(struct led_trigger *trigger);
169extern void led_trigger_event(struct led_trigger *trigger,
170 enum led_brightness event);
171extern void led_trigger_blink(struct led_trigger *trigger,
172 unsigned long *delay_on,
173 unsigned long *delay_off);
174extern 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
192extern 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 */
200struct led_info {
201 const char *name;
202 const char *default_trigger;
203 int flags;
204};
205
206struct led_platform_data {
207 int num_leds;
208 struct led_info *leds;
209};
210
211/* For the leds-gpio driver */
212struct 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
225struct 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
237struct platform_device *gpio_led_register_device(
238 int id, const struct gpio_led_platform_data *pdata);
239
240#endif /* __LINUX_LEDS_H_INCLUDED */