1/*
2 * LED Class Core
3 *
4 * Copyright 2005-2006 Openedhand Ltd.
5 *
6 * Author: Richard Purdie <rpurdie@openedhand.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 */
13
14#include <linux/kernel.h>
15#include <linux/leds.h>
16#include <linux/list.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/rwsem.h>
20#include "leds.h"
21
22DECLARE_RWSEM(leds_list_lock);
23EXPORT_SYMBOL_GPL(leds_list_lock);
24
25LIST_HEAD(leds_list);
26EXPORT_SYMBOL_GPL(leds_list);
27
28static void led_set_software_blink(struct led_classdev *led_cdev,
29				   unsigned long delay_on,
30				   unsigned long delay_off)
31{
32	int current_brightness;
33
34	current_brightness = led_get_brightness(led_cdev);
35	if (current_brightness)
36		led_cdev->blink_brightness = current_brightness;
37	if (!led_cdev->blink_brightness)
38		led_cdev->blink_brightness = led_cdev->max_brightness;
39
40	led_cdev->blink_delay_on = delay_on;
41	led_cdev->blink_delay_off = delay_off;
42
43	/* never on - just set to off */
44	if (!delay_on) {
45		led_set_brightness_async(led_cdev, LED_OFF);
46		return;
47	}
48
49	/* never off - just set to brightness */
50	if (!delay_off) {
51		led_set_brightness_async(led_cdev, led_cdev->blink_brightness);
52		return;
53	}
54
55	mod_timer(&led_cdev->blink_timer, jiffies + 1);
56}
57
58
59static void led_blink_setup(struct led_classdev *led_cdev,
60		     unsigned long *delay_on,
61		     unsigned long *delay_off)
62{
63	if (!(led_cdev->flags & LED_BLINK_ONESHOT) &&
64	    led_cdev->blink_set &&
65	    !led_cdev->blink_set(led_cdev, delay_on, delay_off))
66		return;
67
68	/* blink with 1 Hz as default if nothing specified */
69	if (!*delay_on && !*delay_off)
70		*delay_on = *delay_off = 500;
71
72	led_set_software_blink(led_cdev, *delay_on, *delay_off);
73}
74
75void led_blink_set(struct led_classdev *led_cdev,
76		   unsigned long *delay_on,
77		   unsigned long *delay_off)
78{
79	del_timer_sync(&led_cdev->blink_timer);
80
81	led_cdev->flags &= ~LED_BLINK_ONESHOT;
82	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
83
84	led_blink_setup(led_cdev, delay_on, delay_off);
85}
86EXPORT_SYMBOL(led_blink_set);
87
88void led_blink_set_oneshot(struct led_classdev *led_cdev,
89			   unsigned long *delay_on,
90			   unsigned long *delay_off,
91			   int invert)
92{
93	if ((led_cdev->flags & LED_BLINK_ONESHOT) &&
94	     timer_pending(&led_cdev->blink_timer))
95		return;
96
97	led_cdev->flags |= LED_BLINK_ONESHOT;
98	led_cdev->flags &= ~LED_BLINK_ONESHOT_STOP;
99
100	if (invert)
101		led_cdev->flags |= LED_BLINK_INVERT;
102	else
103		led_cdev->flags &= ~LED_BLINK_INVERT;
104
105	led_blink_setup(led_cdev, delay_on, delay_off);
106}
107EXPORT_SYMBOL(led_blink_set_oneshot);
108
109void led_stop_software_blink(struct led_classdev *led_cdev)
110{
111	del_timer_sync(&led_cdev->blink_timer);
112	led_cdev->blink_delay_on = 0;
113	led_cdev->blink_delay_off = 0;
114}
115EXPORT_SYMBOL_GPL(led_stop_software_blink);
116
117void led_set_brightness(struct led_classdev *led_cdev,
118			enum led_brightness brightness)
119{
120	int ret = 0;
121
122	/* delay brightness setting if need to stop soft-blink timer */
123	if (led_cdev->blink_delay_on || led_cdev->blink_delay_off) {
124		led_cdev->delayed_set_value = brightness;
125		schedule_work(&led_cdev->set_brightness_work);
126		return;
127	}
128
129	if (led_cdev->flags & SET_BRIGHTNESS_ASYNC) {
130		led_set_brightness_async(led_cdev, brightness);
131		return;
132	} else if (led_cdev->flags & SET_BRIGHTNESS_SYNC)
133		ret = led_set_brightness_sync(led_cdev, brightness);
134	else
135		ret = -EINVAL;
136
137	if (ret < 0)
138		dev_dbg(led_cdev->dev, "Setting LED brightness failed (%d)\n",
139			ret);
140}
141EXPORT_SYMBOL(led_set_brightness);
142
143int led_update_brightness(struct led_classdev *led_cdev)
144{
145	int ret = 0;
146
147	if (led_cdev->brightness_get) {
148		ret = led_cdev->brightness_get(led_cdev);
149		if (ret >= 0) {
150			led_cdev->brightness = ret;
151			return 0;
152		}
153	}
154
155	return ret;
156}
157EXPORT_SYMBOL(led_update_brightness);
158
159/* Caller must ensure led_cdev->led_access held */
160void led_sysfs_disable(struct led_classdev *led_cdev)
161{
162	lockdep_assert_held(&led_cdev->led_access);
163
164	led_cdev->flags |= LED_SYSFS_DISABLE;
165}
166EXPORT_SYMBOL_GPL(led_sysfs_disable);
167
168/* Caller must ensure led_cdev->led_access held */
169void led_sysfs_enable(struct led_classdev *led_cdev)
170{
171	lockdep_assert_held(&led_cdev->led_access);
172
173	led_cdev->flags &= ~LED_SYSFS_DISABLE;
174}
175EXPORT_SYMBOL_GPL(led_sysfs_enable);
176