[PATCH] drivers/led: handle sysfs errors
[linux-2.6.git] / 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/kernel.h>
16 #include <linux/init.h>
17 #include <linux/list.h>
18 #include <linux/spinlock.h>
19 #include <linux/device.h>
20 #include <linux/sysdev.h>
21 #include <linux/timer.h>
22 #include <linux/ctype.h>
23 #include <linux/leds.h>
24 #include "leds.h"
25
26 struct timer_trig_data {
27         unsigned long delay_on;         /* milliseconds on */
28         unsigned long delay_off;        /* milliseconds off */
29         struct timer_list timer;
30 };
31
32 static 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
54 static 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
64 static 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         size_t count = after - buf;
73
74         if (*after && isspace(*after))
75                 count++;
76
77         if (count == size) {
78                 timer_data->delay_on = state;
79                 mod_timer(&timer_data->timer, jiffies + 1);
80                 ret = count;
81         }
82
83         return ret;
84 }
85
86 static ssize_t led_delay_off_show(struct class_device *dev, char *buf)
87 {
88         struct led_classdev *led_cdev = class_get_devdata(dev);
89         struct timer_trig_data *timer_data = led_cdev->trigger_data;
90
91         sprintf(buf, "%lu\n", timer_data->delay_off);
92
93         return strlen(buf) + 1;
94 }
95
96 static ssize_t led_delay_off_store(struct class_device *dev, const char *buf,
97                                 size_t size)
98 {
99         struct led_classdev *led_cdev = class_get_devdata(dev);
100         struct timer_trig_data *timer_data = led_cdev->trigger_data;
101         int ret = -EINVAL;
102         char *after;
103         unsigned long state = simple_strtoul(buf, &after, 10);
104         size_t count = after - buf;
105
106         if (*after && isspace(*after))
107                 count++;
108
109         if (count == size) {
110                 timer_data->delay_off = state;
111                 mod_timer(&timer_data->timer, jiffies + 1);
112                 ret = count;
113         }
114
115         return ret;
116 }
117
118 static CLASS_DEVICE_ATTR(delay_on, 0644, led_delay_on_show,
119                         led_delay_on_store);
120 static CLASS_DEVICE_ATTR(delay_off, 0644, led_delay_off_show,
121                         led_delay_off_store);
122
123 static void timer_trig_activate(struct led_classdev *led_cdev)
124 {
125         struct timer_trig_data *timer_data;
126         int rc;
127
128         timer_data = kzalloc(sizeof(struct timer_trig_data), GFP_KERNEL);
129         if (!timer_data)
130                 return;
131
132         led_cdev->trigger_data = timer_data;
133
134         init_timer(&timer_data->timer);
135         timer_data->timer.function = led_timer_function;
136         timer_data->timer.data = (unsigned long) led_cdev;
137
138         rc = class_device_create_file(led_cdev->class_dev,
139                                 &class_device_attr_delay_on);
140         if (rc) goto err_out;
141         rc = class_device_create_file(led_cdev->class_dev,
142                                 &class_device_attr_delay_off);
143         if (rc) goto err_out_delayon;
144
145         return;
146
147 err_out_delayon:
148         class_device_remove_file(led_cdev->class_dev,
149                                 &class_device_attr_delay_on);
150 err_out:
151         led_cdev->trigger_data = NULL;
152         kfree(timer_data);
153 }
154
155 static void timer_trig_deactivate(struct led_classdev *led_cdev)
156 {
157         struct timer_trig_data *timer_data = led_cdev->trigger_data;
158
159         if (timer_data) {
160                 class_device_remove_file(led_cdev->class_dev,
161                                         &class_device_attr_delay_on);
162                 class_device_remove_file(led_cdev->class_dev,
163                                         &class_device_attr_delay_off);
164                 del_timer_sync(&timer_data->timer);
165                 kfree(timer_data);
166         }
167 }
168
169 static struct led_trigger timer_led_trigger = {
170         .name     = "timer",
171         .activate = timer_trig_activate,
172         .deactivate = timer_trig_deactivate,
173 };
174
175 static int __init timer_trig_init(void)
176 {
177         return led_trigger_register(&timer_led_trigger);
178 }
179
180 static void __exit timer_trig_exit(void)
181 {
182         led_trigger_unregister(&timer_led_trigger);
183 }
184
185 module_init(timer_trig_init);
186 module_exit(timer_trig_exit);
187
188 MODULE_AUTHOR("Richard Purdie <rpurdie@openedhand.com>");
189 MODULE_DESCRIPTION("Timer LED trigger");
190 MODULE_LICENSE("GPL");