Merge branch 'tracing-v28-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6] / drivers / leds / ledtrig-timer.c
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/module.h>
15 #include <linux/jiffies.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/ctype.h>
24 #include <linux/leds.h>
25 #include "leds.h"
26
27 struct timer_trig_data {
28         int brightness_on;              /* LED brightness during "on" period.
29                                          * (LED_OFF < brightness_on <= LED_FULL)
30                                          */
31         unsigned long delay_on;         /* milliseconds on */
32         unsigned long delay_off;        /* milliseconds off */
33         struct timer_list timer;
34 };
35
36 static void led_timer_function(unsigned long data)
37 {
38         struct led_classdev *led_cdev = (struct led_classdev *) data;
39         struct timer_trig_data *timer_data = led_cdev->trigger_data;
40         unsigned long brightness;
41         unsigned long delay;
42
43         if (!timer_data->delay_on || !timer_data->delay_off) {
44                 led_set_brightness(led_cdev, LED_OFF);
45                 return;
46         }
47
48         brightness = led_get_brightness(led_cdev);
49         if (!brightness) {
50                 /* Time to switch the LED on. */
51                 brightness = timer_data->brightness_on;
52                 delay = timer_data->delay_on;
53         } else {
54                 /* Store the current brightness value to be able
55                  * to restore it when the delay_off period is over.
56                  */
57                 timer_data->brightness_on = brightness;
58                 brightness = LED_OFF;
59                 delay = timer_data->delay_off;
60         }
61
62         led_set_brightness(led_cdev, brightness);
63
64         mod_timer(&timer_data->timer, jiffies + msecs_to_jiffies(delay));
65 }
66
67 static ssize_t led_delay_on_show(struct device *dev,
68                 struct device_attribute *attr, char *buf)
69 {
70         struct led_classdev *led_cdev = dev_get_drvdata(dev);
71         struct timer_trig_data *timer_data = led_cdev->trigger_data;
72
73         sprintf(buf, "%lu\n", timer_data->delay_on);
74
75         return strlen(buf) + 1;
76 }
77
78 static ssize_t led_delay_on_store(struct device *dev,
79                 struct device_attribute *attr, const char *buf, size_t size)
80 {
81         struct led_classdev *led_cdev = dev_get_drvdata(dev);
82         struct timer_trig_data *timer_data = led_cdev->trigger_data;
83         int ret = -EINVAL;
84         char *after;
85         unsigned long state = simple_strtoul(buf, &after, 10);
86         size_t count = after - buf;
87
88         if (*after && isspace(*after))
89                 count++;
90
91         if (count == size) {
92                 if (timer_data->delay_on != state) {
93                         /* the new value differs from the previous */
94                         timer_data->delay_on = state;
95
96                         /* deactivate previous settings */
97                         del_timer_sync(&timer_data->timer);
98
99                         /* try to activate hardware acceleration, if any */
100                         if (!led_cdev->blink_set ||
101                             led_cdev->blink_set(led_cdev,
102                               &timer_data->delay_on, &timer_data->delay_off)) {
103                                 /* no hardware acceleration, blink via timer */
104                                 mod_timer(&timer_data->timer, jiffies + 1);
105                         }
106                 }
107                 ret = count;
108         }
109
110         return ret;
111 }
112
113 static ssize_t led_delay_off_show(struct device *dev,
114                 struct device_attribute *attr, char *buf)
115 {
116         struct led_classdev *led_cdev = dev_get_drvdata(dev);
117         struct timer_trig_data *timer_data = led_cdev->trigger_data;
118
119         sprintf(buf, "%lu\n", timer_data->delay_off);
120
121         return strlen(buf) + 1;
122 }
123
124 static ssize_t led_delay_off_store(struct device *dev,
125                 struct device_attribute *attr, const char *buf, size_t size)
126 {
127         struct led_classdev *led_cdev = dev_get_drvdata(dev);
128         struct timer_trig_data *timer_data = led_cdev->trigger_data;
129         int ret = -EINVAL;
130         char *after;
131         unsigned long state = simple_strtoul(buf, &after, 10);
132         size_t count = after - buf;
133
134         if (*after && isspace(*after))
135                 count++;
136
137         if (count == size) {
138                 if (timer_data->delay_off != state) {
139                         /* the new value differs from the previous */
140                         timer_data->delay_off = state;
141
142                         /* deactivate previous settings */
143                         del_timer_sync(&timer_data->timer);
144
145                         /* try to activate hardware acceleration, if any */
146                         if (!led_cdev->blink_set ||
147                             led_cdev->blink_set(led_cdev,
148                               &timer_data->delay_on, &timer_data->delay_off)) {
149                                 /* no hardware acceleration, blink via timer */
150                                 mod_timer(&timer_data->timer, jiffies + 1);
151                         }
152                 }
153                 ret = count;
154         }
155
156         return ret;
157 }
158
159 static DEVICE_ATTR(delay_on, 0644, led_delay_on_show, led_delay_on_store);
160 static DEVICE_ATTR(delay_off, 0644, led_delay_off_show, led_delay_off_store);
161
162 static void timer_trig_activate(struct led_classdev *led_cdev)
163 {
164         struct timer_trig_data *timer_data;
165         int rc;
166
167         timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
168         if (!timer_data)
169                 return;
170
171         timer_data->brightness_on = led_get_brightness(led_cdev);
172         if (timer_data->brightness_on == LED_OFF)
173                 timer_data->brightness_on = LED_FULL;
174         led_cdev->trigger_data = timer_data;
175
176         init_timer(&timer_data->timer);
177         timer_data->timer.function = led_timer_function;
178         timer_data->timer.data = (unsigned long) led_cdev;
179
180         rc = device_create_file(led_cdev->dev, &dev_attr_delay_on);
181         if (rc)
182                 goto err_out;
183         rc = device_create_file(led_cdev->dev, &dev_attr_delay_off);
184         if (rc)
185                 goto err_out_delayon;
186
187         /* If there is hardware support for blinking, start one
188          * user friendly blink rate chosen by the driver.
189          */
190         if (led_cdev->blink_set)
191                 led_cdev->blink_set(led_cdev,
192                         &timer_data->delay_on, &timer_data->delay_off);
193
194         return;
195
196 err_out_delayon:
197         device_remove_file(led_cdev->dev, &dev_attr_delay_on);
198 err_out:
199         led_cdev->trigger_data = NULL;
200         kfree(timer_data);
201 }
202
203 static void timer_trig_deactivate(struct led_classdev *led_cdev)
204 {
205         struct timer_trig_data *timer_data = led_cdev->trigger_data;
206
207         if (timer_data) {
208                 device_remove_file(led_cdev->dev, &dev_attr_delay_on);
209                 device_remove_file(led_cdev->dev, &dev_attr_delay_off);
210                 del_timer_sync(&timer_data->timer);
211                 kfree(timer_data);
212         }
213 }
214
215 static struct led_trigger timer_led_trigger = {
216         .name     = "timer",
217         .activate = timer_trig_activate,
218         .deactivate = timer_trig_deactivate,
219 };
220
221 static int __init timer_trig_init(void)
222 {
223         return led_trigger_register(&timer_led_trigger);
224 }
225
226 static void __exit timer_trig_exit(void)
227 {
228         led_trigger_unregister(&timer_led_trigger);
229 }
230
231 module_init(timer_trig_init);
232 module_exit(timer_trig_exit);
233
234 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
235 MODULE_DESCRIPTION("Timer LED trigger");
236 MODULE_LICENSE("GPL");