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c3bc9956 RP |
1 | /* |
2 | * LED Triggers Core | |
3 | * | |
f8a7c6fe | 4 | * Copyright 2005-2007 Openedhand Ltd. |
c3bc9956 RP |
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 | ||
c3bc9956 RP |
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> | |
dc47206e | 22 | #include <linux/rwsem.h> |
c3bc9956 RP |
23 | #include <linux/leds.h> |
24 | #include "leds.h" | |
25 | ||
26 | /* | |
27 | * Nests outside led_cdev->trigger_lock | |
28 | */ | |
dc47206e | 29 | static DECLARE_RWSEM(triggers_list_lock); |
c3bc9956 RP |
30 | static LIST_HEAD(trigger_list); |
31 | ||
f8a7c6fe RP |
32 | ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr, |
33 | const char *buf, size_t count) | |
c3bc9956 | 34 | { |
f8a7c6fe | 35 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
c3bc9956 RP |
36 | char trigger_name[TRIG_NAME_MAX]; |
37 | struct led_trigger *trig; | |
38 | size_t len; | |
39 | ||
40 | trigger_name[sizeof(trigger_name) - 1] = '\0'; | |
41 | strncpy(trigger_name, buf, sizeof(trigger_name) - 1); | |
42 | len = strlen(trigger_name); | |
43 | ||
44 | if (len && trigger_name[len - 1] == '\n') | |
45 | trigger_name[len - 1] = '\0'; | |
46 | ||
47 | if (!strcmp(trigger_name, "none")) { | |
dc47206e | 48 | down_write(&led_cdev->trigger_lock); |
c3bc9956 | 49 | led_trigger_set(led_cdev, NULL); |
dc47206e | 50 | up_write(&led_cdev->trigger_lock); |
c3bc9956 RP |
51 | return count; |
52 | } | |
53 | ||
dc47206e | 54 | down_read(&triggers_list_lock); |
c3bc9956 RP |
55 | list_for_each_entry(trig, &trigger_list, next_trig) { |
56 | if (!strcmp(trigger_name, trig->name)) { | |
dc47206e | 57 | down_write(&led_cdev->trigger_lock); |
c3bc9956 | 58 | led_trigger_set(led_cdev, trig); |
dc47206e | 59 | up_write(&led_cdev->trigger_lock); |
c3bc9956 | 60 | |
dc47206e | 61 | up_read(&triggers_list_lock); |
c3bc9956 RP |
62 | return count; |
63 | } | |
64 | } | |
dc47206e | 65 | up_read(&triggers_list_lock); |
c3bc9956 RP |
66 | |
67 | return -EINVAL; | |
68 | } | |
69 | ||
70 | ||
f8a7c6fe RP |
71 | ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr, |
72 | char *buf) | |
c3bc9956 | 73 | { |
f8a7c6fe | 74 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
c3bc9956 RP |
75 | struct led_trigger *trig; |
76 | int len = 0; | |
77 | ||
dc47206e RP |
78 | down_read(&triggers_list_lock); |
79 | down_read(&led_cdev->trigger_lock); | |
c3bc9956 RP |
80 | |
81 | if (!led_cdev->trigger) | |
82 | len += sprintf(buf+len, "[none] "); | |
83 | else | |
84 | len += sprintf(buf+len, "none "); | |
85 | ||
86 | list_for_each_entry(trig, &trigger_list, next_trig) { | |
87 | if (led_cdev->trigger && !strcmp(led_cdev->trigger->name, | |
88 | trig->name)) | |
89 | len += sprintf(buf+len, "[%s] ", trig->name); | |
90 | else | |
91 | len += sprintf(buf+len, "%s ", trig->name); | |
92 | } | |
dc47206e RP |
93 | up_read(&led_cdev->trigger_lock); |
94 | up_read(&triggers_list_lock); | |
c3bc9956 RP |
95 | |
96 | len += sprintf(len+buf, "\n"); | |
97 | return len; | |
98 | } | |
99 | ||
100 | void led_trigger_event(struct led_trigger *trigger, | |
101 | enum led_brightness brightness) | |
102 | { | |
103 | struct list_head *entry; | |
104 | ||
105 | if (!trigger) | |
106 | return; | |
107 | ||
108 | read_lock(&trigger->leddev_list_lock); | |
109 | list_for_each(entry, &trigger->led_cdevs) { | |
110 | struct led_classdev *led_cdev; | |
111 | ||
112 | led_cdev = list_entry(entry, struct led_classdev, trig_list); | |
113 | led_set_brightness(led_cdev, brightness); | |
114 | } | |
115 | read_unlock(&trigger->leddev_list_lock); | |
116 | } | |
117 | ||
118 | /* Caller must ensure led_cdev->trigger_lock held */ | |
119 | void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger) | |
120 | { | |
121 | unsigned long flags; | |
122 | ||
123 | /* Remove any existing trigger */ | |
124 | if (led_cdev->trigger) { | |
125 | write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags); | |
126 | list_del(&led_cdev->trig_list); | |
127 | write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags); | |
128 | if (led_cdev->trigger->deactivate) | |
129 | led_cdev->trigger->deactivate(led_cdev); | |
e3e5fc91 | 130 | led_set_brightness(led_cdev, LED_OFF); |
c3bc9956 RP |
131 | } |
132 | if (trigger) { | |
133 | write_lock_irqsave(&trigger->leddev_list_lock, flags); | |
134 | list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs); | |
135 | write_unlock_irqrestore(&trigger->leddev_list_lock, flags); | |
136 | if (trigger->activate) | |
137 | trigger->activate(led_cdev); | |
138 | } | |
139 | led_cdev->trigger = trigger; | |
140 | } | |
141 | ||
142 | void led_trigger_set_default(struct led_classdev *led_cdev) | |
143 | { | |
144 | struct led_trigger *trig; | |
145 | ||
146 | if (!led_cdev->default_trigger) | |
147 | return; | |
148 | ||
dc47206e RP |
149 | down_read(&triggers_list_lock); |
150 | down_write(&led_cdev->trigger_lock); | |
c3bc9956 RP |
151 | list_for_each_entry(trig, &trigger_list, next_trig) { |
152 | if (!strcmp(led_cdev->default_trigger, trig->name)) | |
153 | led_trigger_set(led_cdev, trig); | |
154 | } | |
dc47206e RP |
155 | up_write(&led_cdev->trigger_lock); |
156 | up_read(&triggers_list_lock); | |
c3bc9956 RP |
157 | } |
158 | ||
159 | int led_trigger_register(struct led_trigger *trigger) | |
160 | { | |
161 | struct led_classdev *led_cdev; | |
162 | ||
163 | rwlock_init(&trigger->leddev_list_lock); | |
164 | INIT_LIST_HEAD(&trigger->led_cdevs); | |
165 | ||
166 | /* Add to the list of led triggers */ | |
dc47206e | 167 | down_write(&triggers_list_lock); |
c3bc9956 | 168 | list_add_tail(&trigger->next_trig, &trigger_list); |
dc47206e | 169 | up_write(&triggers_list_lock); |
c3bc9956 RP |
170 | |
171 | /* Register with any LEDs that have this as a default trigger */ | |
72f8da32 | 172 | down_read(&leds_list_lock); |
c3bc9956 | 173 | list_for_each_entry(led_cdev, &leds_list, node) { |
dc47206e | 174 | down_write(&led_cdev->trigger_lock); |
c3bc9956 RP |
175 | if (!led_cdev->trigger && led_cdev->default_trigger && |
176 | !strcmp(led_cdev->default_trigger, trigger->name)) | |
177 | led_trigger_set(led_cdev, trigger); | |
dc47206e | 178 | up_write(&led_cdev->trigger_lock); |
c3bc9956 | 179 | } |
72f8da32 | 180 | up_read(&leds_list_lock); |
c3bc9956 RP |
181 | |
182 | return 0; | |
183 | } | |
184 | ||
185 | void led_trigger_register_simple(const char *name, struct led_trigger **tp) | |
186 | { | |
187 | struct led_trigger *trigger; | |
e3986f63 | 188 | int err; |
c3bc9956 RP |
189 | |
190 | trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL); | |
191 | ||
192 | if (trigger) { | |
193 | trigger->name = name; | |
e3986f63 RP |
194 | err = led_trigger_register(trigger); |
195 | if (err < 0) | |
196 | printk(KERN_WARNING "LED trigger %s failed to register" | |
197 | " (%d)\n", name, err); | |
198 | } else | |
199 | printk(KERN_WARNING "LED trigger %s failed to register" | |
200 | " (no memory)\n", name); | |
201 | ||
c3bc9956 RP |
202 | *tp = trigger; |
203 | } | |
204 | ||
205 | void led_trigger_unregister(struct led_trigger *trigger) | |
206 | { | |
207 | struct led_classdev *led_cdev; | |
208 | ||
209 | /* Remove from the list of led triggers */ | |
dc47206e | 210 | down_write(&triggers_list_lock); |
c3bc9956 | 211 | list_del(&trigger->next_trig); |
dc47206e | 212 | up_write(&triggers_list_lock); |
c3bc9956 RP |
213 | |
214 | /* Remove anyone actively using this trigger */ | |
72f8da32 | 215 | down_read(&leds_list_lock); |
c3bc9956 | 216 | list_for_each_entry(led_cdev, &leds_list, node) { |
dc47206e | 217 | down_write(&led_cdev->trigger_lock); |
c3bc9956 RP |
218 | if (led_cdev->trigger == trigger) |
219 | led_trigger_set(led_cdev, NULL); | |
dc47206e | 220 | up_write(&led_cdev->trigger_lock); |
c3bc9956 | 221 | } |
72f8da32 | 222 | up_read(&leds_list_lock); |
c3bc9956 RP |
223 | } |
224 | ||
225 | void led_trigger_unregister_simple(struct led_trigger *trigger) | |
226 | { | |
3593a6d6 RP |
227 | if (trigger) |
228 | led_trigger_unregister(trigger); | |
c3bc9956 RP |
229 | kfree(trigger); |
230 | } | |
231 | ||
232 | /* Used by LED Class */ | |
233 | EXPORT_SYMBOL_GPL(led_trigger_set); | |
234 | EXPORT_SYMBOL_GPL(led_trigger_set_default); | |
235 | EXPORT_SYMBOL_GPL(led_trigger_show); | |
236 | EXPORT_SYMBOL_GPL(led_trigger_store); | |
237 | ||
238 | /* LED Trigger Interface */ | |
239 | EXPORT_SYMBOL_GPL(led_trigger_register); | |
240 | EXPORT_SYMBOL_GPL(led_trigger_unregister); | |
241 | ||
242 | /* Simple LED Tigger Interface */ | |
243 | EXPORT_SYMBOL_GPL(led_trigger_register_simple); | |
244 | EXPORT_SYMBOL_GPL(led_trigger_unregister_simple); | |
245 | EXPORT_SYMBOL_GPL(led_trigger_event); | |
246 | ||
247 | MODULE_AUTHOR("Richard Purdie"); | |
248 | MODULE_LICENSE("GPL"); | |
249 | MODULE_DESCRIPTION("LED Triggers Core"); |