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authorRichard Purdie <rpurdie@rpsys.net>2006-03-31 05:31:07 -0500
committerLinus Torvalds <torvalds@g5.osdl.org>2006-03-31 15:18:57 -0500
commit6655c6fe575b720eb8cb6c143ae10995a7aa1916 (patch)
tree72b36d5346ef1cdd50417b8b4accb4d5b58d003a /drivers/leds/ledtrig-timer.c
parentc3bc9956ec52fb2c70f29aa894d8eec766116584 (diff)
[PATCH] LED: add LED timer trigger
Add an example of a complex LED trigger in the form of a generic timer which triggers the LED its attached to at a user specified frequency and duty cycle. Signed-off-by: Richard Purdie <rpurdie@rpsys.net> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/leds/ledtrig-timer.c')
-rw-r--r--drivers/leds/ledtrig-timer.c170
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/leds/ledtrig-timer.c b/drivers/leds/ledtrig-timer.c
new file mode 100644
index 000000000000..f484b5d6dbf8
--- /dev/null
+++ b/drivers/leds/ledtrig-timer.c
@@ -0,0 +1,170 @@
1/*
2 * LED Kernel Timer Trigger
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/config.h>
15#include <linux/module.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/list.h>
19#include <linux/spinlock.h>
20#include <linux/device.h>
21#include <linux/sysdev.h>
22#include <linux/timer.h>
23#include <linux/leds.h>
24#include "leds.h"
25
26struct timer_trig_data {
27 unsigned long delay_on; /* milliseconds on */
28 unsigned long delay_off; /* milliseconds off */
29 struct timer_list timer;
30};
31
32static void led_timer_function(unsigned long data)
33{
34 struct led_classdev *led_cdev = (struct led_classdev *) data;
35 struct timer_trig_data *timer_data = led_cdev->trigger_data;
36 unsigned long brightness = LED_OFF;
37 unsigned long delay = timer_data->delay_off;
38
39 if (!timer_data->delay_on || !timer_data->delay_off) {
40 led_set_brightness(led_cdev, LED_OFF);
41 return;
42 }
43
44 if (!led_cdev->brightness) {
45 brightness = LED_FULL;
46 delay = timer_data->delay_on;
47 }
48
49 led_set_brightness(led_cdev, brightness);
50
51 mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(delay));
52}
53
54static ssize_t led_delay_on_show(struct class_device *dev, char *buf)
55{
56 struct led_classdev *led_cdev = class_get_devdata(dev);
57 struct timer_trig_data *timer_data = led_cdev->trigger_data;
58
59 sprintf(buf, "%lu\n", timer_data->delay_on);
60
61 return strlen(buf) + 1;
62}
63
64static ssize_t led_delay_on_store(struct class_device *dev, const char *buf,
65 size_t size)
66{
67 struct led_classdev *led_cdev = class_get_devdata(dev);
68 struct timer_trig_data *timer_data = led_cdev->trigger_data;
69 int ret = -EINVAL;
70 char *after;
71 unsigned long state = simple_strtoul(buf, &after, 10);
72
73 if (after - buf > 0) {
74 timer_data->delay_on = state;
75 mod_timer(&timer_data->timer, jiffies + 1);
76 ret = after - buf;
77 }
78
79 return ret;
80}
81
82static ssize_t led_delay_off_show(struct class_device *dev, char *buf)
83{
84 struct led_classdev *led_cdev = class_get_devdata(dev);
85 struct timer_trig_data *timer_data = led_cdev->trigger_data;
86
87 sprintf(buf, "%lu\n", timer_data->delay_off);
88
89 return strlen(buf) + 1;
90}
91
92static ssize_t led_delay_off_store(struct class_device *dev, const char *buf,
93 size_t size)
94{
95 struct led_classdev *led_cdev = class_get_devdata(dev);
96 struct timer_trig_data *timer_data = led_cdev->trigger_data;
97 int ret = -EINVAL;
98 char *after;
99 unsigned long state = simple_strtoul(buf, &after, 10);
100
101 if (after - buf > 0) {
102 timer_data->delay_off = state;
103 mod_timer(&timer_data->timer, jiffies + 1);
104 ret = after - buf;
105 }
106
107 return ret;
108}
109
110static CLASS_DEVICE_ATTR(delay_on, 0644, led_delay_on_show,
111 led_delay_on_store);
112static CLASS_DEVICE_ATTR(delay_off, 0644, led_delay_off_show,
113 led_delay_off_store);
114
115static void timer_trig_activate(struct led_classdev *led_cdev)
116{
117 struct timer_trig_data *timer_data;
118
119 timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
120 if (!timer_data)
121 return;
122
123 led_cdev->trigger_data = timer_data;
124
125 init_timer(&timer_data->timer);
126 timer_data->timer.function = led_timer_function;
127 timer_data->timer.data = (unsigned long) led_cdev;
128
129 class_device_create_file(led_cdev->class_dev,
130 &class_device_attr_delay_on);
131 class_device_create_file(led_cdev->class_dev,
132 &class_device_attr_delay_off);
133}
134
135static void timer_trig_deactivate(struct led_classdev *led_cdev)
136{
137 struct timer_trig_data *timer_data = led_cdev->trigger_data;
138
139 if (timer_data) {
140 class_device_remove_file(led_cdev->class_dev,
141 &class_device_attr_delay_on);
142 class_device_remove_file(led_cdev->class_dev,
143 &class_device_attr_delay_off);
144 del_timer_sync(&timer_data->timer);
145 kfree(timer_data);
146 }
147}
148
149static struct led_trigger timer_led_trigger = {
150 .name = "timer",
151 .activate = timer_trig_activate,
152 .deactivate = timer_trig_deactivate,
153};
154
155static int __init timer_trig_init(void)
156{
157 return led_trigger_register(&timer_led_trigger);
158}
159
160static void __exit timer_trig_exit(void)
161{
162 led_trigger_unregister(&timer_led_trigger);
163}
164
165module_init(timer_trig_init);
166module_exit(timer_trig_exit);
167
168MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
169MODULE_DESCRIPTION("Timer LED trigger");
170MODULE_LICENSE("GPL");