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c3bc9956 RP |
1 | /* |
2 | * LED Triggers Core | |
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 | ||
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> | |
22 | #include <linux/leds.h> | |
23 | #include "leds.h" | |
24 | ||
25 | /* | |
26 | * Nests outside led_cdev->trigger_lock | |
27 | */ | |
34af946a | 28 | static DEFINE_RWLOCK(triggers_list_lock); |
c3bc9956 RP |
29 | static LIST_HEAD(trigger_list); |
30 | ||
31 | ssize_t led_trigger_store(struct class_device *dev, const char *buf, | |
32 | size_t count) | |
33 | { | |
34 | struct led_classdev *led_cdev = class_get_devdata(dev); | |
35 | char trigger_name[TRIG_NAME_MAX]; | |
36 | struct led_trigger *trig; | |
37 | size_t len; | |
38 | ||
39 | trigger_name[sizeof(trigger_name) - 1] = '\0'; | |
40 | strncpy(trigger_name, buf, sizeof(trigger_name) - 1); | |
41 | len = strlen(trigger_name); | |
42 | ||
43 | if (len && trigger_name[len - 1] == '\n') | |
44 | trigger_name[len - 1] = '\0'; | |
45 | ||
46 | if (!strcmp(trigger_name, "none")) { | |
47 | write_lock(&led_cdev->trigger_lock); | |
48 | led_trigger_set(led_cdev, NULL); | |
49 | write_unlock(&led_cdev->trigger_lock); | |
50 | return count; | |
51 | } | |
52 | ||
53 | read_lock(&triggers_list_lock); | |
54 | list_for_each_entry(trig, &trigger_list, next_trig) { | |
55 | if (!strcmp(trigger_name, trig->name)) { | |
56 | write_lock(&led_cdev->trigger_lock); | |
57 | led_trigger_set(led_cdev, trig); | |
58 | write_unlock(&led_cdev->trigger_lock); | |
59 | ||
60 | read_unlock(&triggers_list_lock); | |
61 | return count; | |
62 | } | |
63 | } | |
64 | read_unlock(&triggers_list_lock); | |
65 | ||
66 | return -EINVAL; | |
67 | } | |
68 | ||
69 | ||
70 | ssize_t led_trigger_show(struct class_device *dev, char *buf) | |
71 | { | |
72 | struct led_classdev *led_cdev = class_get_devdata(dev); | |
73 | struct led_trigger *trig; | |
74 | int len = 0; | |
75 | ||
76 | read_lock(&triggers_list_lock); | |
77 | read_lock(&led_cdev->trigger_lock); | |
78 | ||
79 | if (!led_cdev->trigger) | |
80 | len += sprintf(buf+len, "[none] "); | |
81 | else | |
82 | len += sprintf(buf+len, "none "); | |
83 | ||
84 | list_for_each_entry(trig, &trigger_list, next_trig) { | |
85 | if (led_cdev->trigger && !strcmp(led_cdev->trigger->name, | |
86 | trig->name)) | |
87 | len += sprintf(buf+len, "[%s] ", trig->name); | |
88 | else | |
89 | len += sprintf(buf+len, "%s ", trig->name); | |
90 | } | |
91 | read_unlock(&led_cdev->trigger_lock); | |
92 | read_unlock(&triggers_list_lock); | |
93 | ||
94 | len += sprintf(len+buf, "\n"); | |
95 | return len; | |
96 | } | |
97 | ||
98 | void led_trigger_event(struct led_trigger *trigger, | |
99 | enum led_brightness brightness) | |
100 | { | |
101 | struct list_head *entry; | |
102 | ||
103 | if (!trigger) | |
104 | return; | |
105 | ||
106 | read_lock(&trigger->leddev_list_lock); | |
107 | list_for_each(entry, &trigger->led_cdevs) { | |
108 | struct led_classdev *led_cdev; | |
109 | ||
110 | led_cdev = list_entry(entry, struct led_classdev, trig_list); | |
111 | led_set_brightness(led_cdev, brightness); | |
112 | } | |
113 | read_unlock(&trigger->leddev_list_lock); | |
114 | } | |
115 | ||
116 | /* Caller must ensure led_cdev->trigger_lock held */ | |
117 | void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trigger) | |
118 | { | |
119 | unsigned long flags; | |
120 | ||
121 | /* Remove any existing trigger */ | |
122 | if (led_cdev->trigger) { | |
123 | write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags); | |
124 | list_del(&led_cdev->trig_list); | |
125 | write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock, flags); | |
126 | if (led_cdev->trigger->deactivate) | |
127 | led_cdev->trigger->deactivate(led_cdev); | |
128 | } | |
129 | if (trigger) { | |
130 | write_lock_irqsave(&trigger->leddev_list_lock, flags); | |
131 | list_add_tail(&led_cdev->trig_list, &trigger->led_cdevs); | |
132 | write_unlock_irqrestore(&trigger->leddev_list_lock, flags); | |
133 | if (trigger->activate) | |
134 | trigger->activate(led_cdev); | |
135 | } | |
136 | led_cdev->trigger = trigger; | |
137 | } | |
138 | ||
139 | void led_trigger_set_default(struct led_classdev *led_cdev) | |
140 | { | |
141 | struct led_trigger *trig; | |
142 | ||
143 | if (!led_cdev->default_trigger) | |
144 | return; | |
145 | ||
146 | read_lock(&triggers_list_lock); | |
147 | write_lock(&led_cdev->trigger_lock); | |
148 | list_for_each_entry(trig, &trigger_list, next_trig) { | |
149 | if (!strcmp(led_cdev->default_trigger, trig->name)) | |
150 | led_trigger_set(led_cdev, trig); | |
151 | } | |
152 | write_unlock(&led_cdev->trigger_lock); | |
153 | read_unlock(&triggers_list_lock); | |
154 | } | |
155 | ||
156 | int led_trigger_register(struct led_trigger *trigger) | |
157 | { | |
158 | struct led_classdev *led_cdev; | |
159 | ||
160 | rwlock_init(&trigger->leddev_list_lock); | |
161 | INIT_LIST_HEAD(&trigger->led_cdevs); | |
162 | ||
163 | /* Add to the list of led triggers */ | |
164 | write_lock(&triggers_list_lock); | |
165 | list_add_tail(&trigger->next_trig, &trigger_list); | |
166 | write_unlock(&triggers_list_lock); | |
167 | ||
168 | /* Register with any LEDs that have this as a default trigger */ | |
169 | read_lock(&leds_list_lock); | |
170 | list_for_each_entry(led_cdev, &leds_list, node) { | |
171 | write_lock(&led_cdev->trigger_lock); | |
172 | if (!led_cdev->trigger && led_cdev->default_trigger && | |
173 | !strcmp(led_cdev->default_trigger, trigger->name)) | |
174 | led_trigger_set(led_cdev, trigger); | |
175 | write_unlock(&led_cdev->trigger_lock); | |
176 | } | |
177 | read_unlock(&leds_list_lock); | |
178 | ||
179 | return 0; | |
180 | } | |
181 | ||
182 | void led_trigger_register_simple(const char *name, struct led_trigger **tp) | |
183 | { | |
184 | struct led_trigger *trigger; | |
185 | ||
186 | trigger = kzalloc(sizeof(struct led_trigger), GFP_KERNEL); | |
187 | ||
188 | if (trigger) { | |
189 | trigger->name = name; | |
190 | led_trigger_register(trigger); | |
191 | } | |
192 | *tp = trigger; | |
193 | } | |
194 | ||
195 | void led_trigger_unregister(struct led_trigger *trigger) | |
196 | { | |
197 | struct led_classdev *led_cdev; | |
198 | ||
199 | /* Remove from the list of led triggers */ | |
200 | write_lock(&triggers_list_lock); | |
201 | list_del(&trigger->next_trig); | |
202 | write_unlock(&triggers_list_lock); | |
203 | ||
204 | /* Remove anyone actively using this trigger */ | |
205 | read_lock(&leds_list_lock); | |
206 | list_for_each_entry(led_cdev, &leds_list, node) { | |
207 | write_lock(&led_cdev->trigger_lock); | |
208 | if (led_cdev->trigger == trigger) | |
209 | led_trigger_set(led_cdev, NULL); | |
210 | write_unlock(&led_cdev->trigger_lock); | |
211 | } | |
212 | read_unlock(&leds_list_lock); | |
213 | } | |
214 | ||
215 | void led_trigger_unregister_simple(struct led_trigger *trigger) | |
216 | { | |
217 | led_trigger_unregister(trigger); | |
218 | kfree(trigger); | |
219 | } | |
220 | ||
221 | /* Used by LED Class */ | |
222 | EXPORT_SYMBOL_GPL(led_trigger_set); | |
223 | EXPORT_SYMBOL_GPL(led_trigger_set_default); | |
224 | EXPORT_SYMBOL_GPL(led_trigger_show); | |
225 | EXPORT_SYMBOL_GPL(led_trigger_store); | |
226 | ||
227 | /* LED Trigger Interface */ | |
228 | EXPORT_SYMBOL_GPL(led_trigger_register); | |
229 | EXPORT_SYMBOL_GPL(led_trigger_unregister); | |
230 | ||
231 | /* Simple LED Tigger Interface */ | |
232 | EXPORT_SYMBOL_GPL(led_trigger_register_simple); | |
233 | EXPORT_SYMBOL_GPL(led_trigger_unregister_simple); | |
234 | EXPORT_SYMBOL_GPL(led_trigger_event); | |
235 | ||
236 | MODULE_AUTHOR("Richard Purdie"); | |
237 | MODULE_LICENSE("GPL"); | |
238 | MODULE_DESCRIPTION("LED Triggers Core"); |