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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 | ||
4d404fd5 NM |
32 | /* Used by LED Class */ |
33 | ||
f8a7c6fe RP |
34 | ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr, |
35 | const char *buf, size_t count) | |
c3bc9956 | 36 | { |
f8a7c6fe | 37 | struct led_classdev *led_cdev = dev_get_drvdata(dev); |
c3bc9956 RP |
38 | char trigger_name[TRIG_NAME_MAX]; |
39 | struct led_trigger *trig; | |
40 | size_t len; | |
41 | ||
42 | trigger_name[sizeof(trigger_name) - 1] = '\0'; | |
43 | strncpy(trigger_name, buf, sizeof(trigger_name) - 1); | |
44 | len = strlen(trigger_name); | |
45 | ||
46 | if (len && trigger_name[len - 1] == '\n') | |
47 | trigger_name[len - 1] = '\0'; | |
48 | ||
49 | if (!strcmp(trigger_name, "none")) { | |
0013b23d | 50 | led_trigger_remove(led_cdev); |
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 | } | |
4d404fd5 | 69 | EXPORT_SYMBOL_GPL(led_trigger_store); |
c3bc9956 | 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 | } | |
4d404fd5 | 99 | EXPORT_SYMBOL_GPL(led_trigger_show); |
c3bc9956 RP |
100 | |
101 | /* Caller must ensure led_cdev->trigger_lock held */ | |
102 | void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger) | |
103 | { | |
104 | unsigned long flags; | |
105 | ||
106 | /* Remove any existing trigger */ | |
107 | if (led_cdev->trigger) { | |
108 | write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags); | |
109 | list_del(&led_cdev->trig_list); | |
4d404fd5 NM |
110 | write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, |
111 | flags); | |
c3bc9956 RP |
112 | if (led_cdev->trigger->deactivate) |
113 | led_cdev->trigger->deactivate(led_cdev); | |
fe3025b5 | 114 | led_cdev->trigger = NULL; |
e3e5fc91 | 115 | led_set_brightness(led_cdev, LED_OFF); |
c3bc9956 RP |
116 | } |
117 | if (trigger) { | |
118 | write_lock_irqsave(&trigger->leddev_list_lock, flags); | |
119 | list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs); | |
120 | write_unlock_irqrestore(&trigger->leddev_list_lock, flags); | |
fe3025b5 | 121 | led_cdev->trigger = trigger; |
c3bc9956 RP |
122 | if (trigger->activate) |
123 | trigger->activate(led_cdev); | |
124 | } | |
c3bc9956 | 125 | } |
4d404fd5 | 126 | EXPORT_SYMBOL_GPL(led_trigger_set); |
c3bc9956 | 127 | |
0013b23d NM |
128 | void led_trigger_remove(struct led_classdev *led_cdev) |
129 | { | |
130 | down_write(&led_cdev->trigger_lock); | |
131 | led_trigger_set(led_cdev, NULL); | |
132 | up_write(&led_cdev->trigger_lock); | |
133 | } | |
4d404fd5 | 134 | EXPORT_SYMBOL_GPL(led_trigger_remove); |
0013b23d | 135 | |
c3bc9956 RP |
136 | void led_trigger_set_default(struct led_classdev *led_cdev) |
137 | { | |
138 | struct led_trigger *trig; | |
139 | ||
140 | if (!led_cdev->default_trigger) | |
141 | return; | |
142 | ||
dc47206e RP |
143 | down_read(&triggers_list_lock); |
144 | down_write(&led_cdev->trigger_lock); | |
c3bc9956 RP |
145 | list_for_each_entry(trig, &trigger_list, next_trig) { |
146 | if (!strcmp(led_cdev->default_trigger, trig->name)) | |
147 | led_trigger_set(led_cdev, trig); | |
148 | } | |
dc47206e RP |
149 | up_write(&led_cdev->trigger_lock); |
150 | up_read(&triggers_list_lock); | |
c3bc9956 | 151 | } |
4d404fd5 NM |
152 | EXPORT_SYMBOL_GPL(led_trigger_set_default); |
153 | ||
154 | /* LED Trigger Interface */ | |
c3bc9956 RP |
155 | |
156 | int led_trigger_register(struct led_trigger *trigger) | |
157 | { | |
158 | struct led_classdev *led_cdev; | |
700c6ea2 | 159 | struct led_trigger *trig; |
c3bc9956 RP |
160 | |
161 | rwlock_init(&trigger->leddev_list_lock); | |
162 | INIT_LIST_HEAD(&trigger->led_cdevs); | |
163 | ||
dc47206e | 164 | down_write(&triggers_list_lock); |
700c6ea2 AN |
165 | /* Make sure the trigger's name isn't already in use */ |
166 | list_for_each_entry(trig, &trigger_list, next_trig) { | |
167 | if (!strcmp(trig->name, trigger->name)) { | |
168 | up_write(&triggers_list_lock); | |
169 | return -EEXIST; | |
170 | } | |
171 | } | |
172 | /* Add to the list of led triggers */ | |
c3bc9956 | 173 | list_add_tail(&trigger->next_trig, &trigger_list); |
dc47206e | 174 | up_write(&triggers_list_lock); |
c3bc9956 RP |
175 | |
176 | /* Register with any LEDs that have this as a default trigger */ | |
72f8da32 | 177 | down_read(&leds_list_lock); |
c3bc9956 | 178 | list_for_each_entry(led_cdev, &leds_list, node) { |
dc47206e | 179 | down_write(&led_cdev->trigger_lock); |
c3bc9956 RP |
180 | if (!led_cdev->trigger && led_cdev->default_trigger && |
181 | !strcmp(led_cdev->default_trigger, trigger->name)) | |
182 | led_trigger_set(led_cdev, trigger); | |
dc47206e | 183 | up_write(&led_cdev->trigger_lock); |
c3bc9956 | 184 | } |
72f8da32 | 185 | up_read(&leds_list_lock); |
c3bc9956 RP |
186 | |
187 | return 0; | |
188 | } | |
4d404fd5 | 189 | EXPORT_SYMBOL_GPL(led_trigger_register); |
c3bc9956 RP |
190 | |
191 | void led_trigger_unregister(struct led_trigger *trigger) | |
192 | { | |
193 | struct led_classdev *led_cdev; | |
194 | ||
195 | /* Remove from the list of led triggers */ | |
dc47206e | 196 | down_write(&triggers_list_lock); |
c3bc9956 | 197 | list_del(&trigger->next_trig); |
dc47206e | 198 | up_write(&triggers_list_lock); |
c3bc9956 RP |
199 | |
200 | /* Remove anyone actively using this trigger */ | |
72f8da32 | 201 | down_read(&leds_list_lock); |
c3bc9956 | 202 | list_for_each_entry(led_cdev, &leds_list, node) { |
dc47206e | 203 | down_write(&led_cdev->trigger_lock); |
c3bc9956 RP |
204 | if (led_cdev->trigger == trigger) |
205 | led_trigger_set(led_cdev, NULL); | |
dc47206e | 206 | up_write(&led_cdev->trigger_lock); |
c3bc9956 | 207 | } |
72f8da32 | 208 | up_read(&leds_list_lock); |
c3bc9956 | 209 | } |
4d404fd5 | 210 | EXPORT_SYMBOL_GPL(led_trigger_unregister); |
c3bc9956 | 211 | |
4d404fd5 NM |
212 | /* Simple LED Tigger Interface */ |
213 | ||
214 | void led_trigger_event(struct led_trigger *trigger, | |
215 | enum led_brightness brightness) | |
c3bc9956 | 216 | { |
4d404fd5 NM |
217 | struct list_head *entry; |
218 | ||
219 | if (!trigger) | |
220 | return; | |
221 | ||
222 | read_lock(&trigger->leddev_list_lock); | |
223 | list_for_each(entry, &trigger->led_cdevs) { | |
224 | struct led_classdev *led_cdev; | |
225 | ||
226 | led_cdev = list_entry(entry, struct led_classdev, trig_list); | |
227 | led_set_brightness(led_cdev, brightness); | |
228 | } | |
229 | read_unlock(&trigger->leddev_list_lock); | |
c3bc9956 | 230 | } |
4d404fd5 | 231 | EXPORT_SYMBOL_GPL(led_trigger_event); |
c3bc9956 | 232 | |
4d404fd5 NM |
233 | void led_trigger_register_simple(const char *name, struct led_trigger **tp) |
234 | { | |
235 | struct led_trigger *trigger; | |
236 | int err; | |
c3bc9956 | 237 | |
4d404fd5 | 238 | trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL); |
c3bc9956 | 239 | |
4d404fd5 NM |
240 | if (trigger) { |
241 | trigger->name = name; | |
242 | err = led_trigger_register(trigger); | |
243 | if (err < 0) | |
244 | printk(KERN_WARNING "LED trigger %s failed to register" | |
245 | " (%d)\n", name, err); | |
246 | } else | |
247 | printk(KERN_WARNING "LED trigger %s failed to register" | |
248 | " (no memory)\n", name); | |
249 | ||
250 | *tp = trigger; | |
251 | } | |
c3bc9956 | 252 | EXPORT_SYMBOL_GPL(led_trigger_register_simple); |
4d404fd5 NM |
253 | |
254 | void led_trigger_unregister_simple(struct led_trigger *trigger) | |
255 | { | |
256 | if (trigger) | |
257 | led_trigger_unregister(trigger); | |
258 | kfree(trigger); | |
259 | } | |
c3bc9956 | 260 | EXPORT_SYMBOL_GPL(led_trigger_unregister_simple); |
c3bc9956 RP |
261 | |
262 | MODULE_AUTHOR("Richard Purdie"); | |
263 | MODULE_LICENSE("GPL"); | |
264 | MODULE_DESCRIPTION("LED Triggers Core"); |