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