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1 | /* |
2 | * LED Kernel Transient Trigger | |
3 | * | |
4 | * Copyright (C) 2012 Shuah Khan <shuahkhan@gmail.com> | |
5 | * | |
6 | * Based on Richard Purdie's ledtrig-timer.c and Atsushi Nemoto's | |
7 | * ledtrig-heartbeat.c | |
8 | * Design and use-case input from Jonas Bonn <jonas@southpole.se> and | |
9 | * Neil Brown <neilb@suse.de> | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or modify | |
12 | * it under the terms of the GNU General Public License version 2 as | |
13 | * published by the Free Software Foundation. | |
14 | * | |
15 | */ | |
16 | /* | |
17 | * Transient trigger allows one shot timer activation. Please refer to | |
18 | * Documentation/leds/ledtrig-transient.txt for details | |
19 | */ | |
20 | ||
21 | #include <linux/module.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/device.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/timer.h> | |
27 | #include <linux/leds.h> | |
f07fb521 | 28 | #include "../leds.h" |
44e1e9f8 SK |
29 | |
30 | struct transient_trig_data { | |
31 | int activate; | |
32 | int state; | |
33 | int restore_state; | |
34 | unsigned long duration; | |
35 | struct timer_list timer; | |
36 | }; | |
37 | ||
38 | static void transient_timer_function(unsigned long data) | |
39 | { | |
40 | struct led_classdev *led_cdev = (struct led_classdev *) data; | |
41 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
42 | ||
43 | transient_data->activate = 0; | |
81fe8e5b | 44 | led_set_brightness_nosleep(led_cdev, transient_data->restore_state); |
44e1e9f8 SK |
45 | } |
46 | ||
47 | static ssize_t transient_activate_show(struct device *dev, | |
48 | struct device_attribute *attr, char *buf) | |
49 | { | |
50 | struct led_classdev *led_cdev = dev_get_drvdata(dev); | |
51 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
52 | ||
53 | return sprintf(buf, "%d\n", transient_data->activate); | |
54 | } | |
55 | ||
56 | static ssize_t transient_activate_store(struct device *dev, | |
57 | struct device_attribute *attr, const char *buf, size_t size) | |
58 | { | |
59 | struct led_classdev *led_cdev = dev_get_drvdata(dev); | |
60 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
61 | unsigned long state; | |
62 | ssize_t ret; | |
63 | ||
64 | ret = kstrtoul(buf, 10, &state); | |
65 | if (ret) | |
66 | return ret; | |
67 | ||
68 | if (state != 1 && state != 0) | |
69 | return -EINVAL; | |
70 | ||
71 | /* cancel the running timer */ | |
72 | if (state == 0 && transient_data->activate == 1) { | |
73 | del_timer(&transient_data->timer); | |
74 | transient_data->activate = state; | |
81fe8e5b | 75 | led_set_brightness_nosleep(led_cdev, |
4d71a4a1 | 76 | transient_data->restore_state); |
44e1e9f8 SK |
77 | return size; |
78 | } | |
79 | ||
80 | /* start timer if there is no active timer */ | |
81 | if (state == 1 && transient_data->activate == 0 && | |
82 | transient_data->duration != 0) { | |
83 | transient_data->activate = state; | |
81fe8e5b | 84 | led_set_brightness_nosleep(led_cdev, transient_data->state); |
44e1e9f8 SK |
85 | transient_data->restore_state = |
86 | (transient_data->state == LED_FULL) ? LED_OFF : LED_FULL; | |
87 | mod_timer(&transient_data->timer, | |
22f933ad | 88 | jiffies + msecs_to_jiffies(transient_data->duration)); |
44e1e9f8 SK |
89 | } |
90 | ||
91 | /* state == 0 && transient_data->activate == 0 | |
92 | timer is not active - just return */ | |
93 | /* state == 1 && transient_data->activate == 1 | |
94 | timer is already active - just return */ | |
95 | ||
96 | return size; | |
97 | } | |
98 | ||
99 | static ssize_t transient_duration_show(struct device *dev, | |
100 | struct device_attribute *attr, char *buf) | |
101 | { | |
102 | struct led_classdev *led_cdev = dev_get_drvdata(dev); | |
103 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
104 | ||
105 | return sprintf(buf, "%lu\n", transient_data->duration); | |
106 | } | |
107 | ||
108 | static ssize_t transient_duration_store(struct device *dev, | |
109 | struct device_attribute *attr, const char *buf, size_t size) | |
110 | { | |
111 | struct led_classdev *led_cdev = dev_get_drvdata(dev); | |
112 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
113 | unsigned long state; | |
114 | ssize_t ret; | |
115 | ||
116 | ret = kstrtoul(buf, 10, &state); | |
117 | if (ret) | |
118 | return ret; | |
119 | ||
120 | transient_data->duration = state; | |
121 | return size; | |
122 | } | |
123 | ||
124 | static ssize_t transient_state_show(struct device *dev, | |
125 | struct device_attribute *attr, char *buf) | |
126 | { | |
127 | struct led_classdev *led_cdev = dev_get_drvdata(dev); | |
128 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
129 | int state; | |
130 | ||
131 | state = (transient_data->state == LED_FULL) ? 1 : 0; | |
132 | return sprintf(buf, "%d\n", state); | |
133 | } | |
134 | ||
135 | static ssize_t transient_state_store(struct device *dev, | |
136 | struct device_attribute *attr, const char *buf, size_t size) | |
137 | { | |
138 | struct led_classdev *led_cdev = dev_get_drvdata(dev); | |
139 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
140 | unsigned long state; | |
141 | ssize_t ret; | |
142 | ||
143 | ret = kstrtoul(buf, 10, &state); | |
144 | if (ret) | |
145 | return ret; | |
146 | ||
147 | if (state != 1 && state != 0) | |
148 | return -EINVAL; | |
149 | ||
150 | transient_data->state = (state == 1) ? LED_FULL : LED_OFF; | |
151 | return size; | |
152 | } | |
153 | ||
154 | static DEVICE_ATTR(activate, 0644, transient_activate_show, | |
155 | transient_activate_store); | |
156 | static DEVICE_ATTR(duration, 0644, transient_duration_show, | |
157 | transient_duration_store); | |
158 | static DEVICE_ATTR(state, 0644, transient_state_show, transient_state_store); | |
159 | ||
160 | static void transient_trig_activate(struct led_classdev *led_cdev) | |
161 | { | |
162 | int rc; | |
163 | struct transient_trig_data *tdata; | |
164 | ||
165 | tdata = kzalloc(sizeof(struct transient_trig_data), GFP_KERNEL); | |
166 | if (!tdata) { | |
167 | dev_err(led_cdev->dev, | |
168 | "unable to allocate transient trigger\n"); | |
169 | return; | |
170 | } | |
171 | led_cdev->trigger_data = tdata; | |
172 | ||
173 | rc = device_create_file(led_cdev->dev, &dev_attr_activate); | |
174 | if (rc) | |
175 | goto err_out; | |
176 | ||
177 | rc = device_create_file(led_cdev->dev, &dev_attr_duration); | |
178 | if (rc) | |
179 | goto err_out_duration; | |
180 | ||
181 | rc = device_create_file(led_cdev->dev, &dev_attr_state); | |
182 | if (rc) | |
183 | goto err_out_state; | |
184 | ||
185 | setup_timer(&tdata->timer, transient_timer_function, | |
186 | (unsigned long) led_cdev); | |
187 | led_cdev->activated = true; | |
188 | ||
189 | return; | |
190 | ||
191 | err_out_state: | |
192 | device_remove_file(led_cdev->dev, &dev_attr_duration); | |
193 | err_out_duration: | |
194 | device_remove_file(led_cdev->dev, &dev_attr_activate); | |
195 | err_out: | |
196 | dev_err(led_cdev->dev, "unable to register transient trigger\n"); | |
197 | led_cdev->trigger_data = NULL; | |
198 | kfree(tdata); | |
199 | } | |
200 | ||
201 | static void transient_trig_deactivate(struct led_classdev *led_cdev) | |
202 | { | |
203 | struct transient_trig_data *transient_data = led_cdev->trigger_data; | |
204 | ||
205 | if (led_cdev->activated) { | |
206 | del_timer_sync(&transient_data->timer); | |
81fe8e5b | 207 | led_set_brightness_nosleep(led_cdev, |
4d71a4a1 | 208 | transient_data->restore_state); |
44e1e9f8 SK |
209 | device_remove_file(led_cdev->dev, &dev_attr_activate); |
210 | device_remove_file(led_cdev->dev, &dev_attr_duration); | |
211 | device_remove_file(led_cdev->dev, &dev_attr_state); | |
212 | led_cdev->trigger_data = NULL; | |
213 | led_cdev->activated = false; | |
214 | kfree(transient_data); | |
215 | } | |
216 | } | |
217 | ||
218 | static struct led_trigger transient_trigger = { | |
219 | .name = "transient", | |
220 | .activate = transient_trig_activate, | |
221 | .deactivate = transient_trig_deactivate, | |
222 | }; | |
223 | ||
224 | static int __init transient_trig_init(void) | |
225 | { | |
226 | return led_trigger_register(&transient_trigger); | |
227 | } | |
228 | ||
229 | static void __exit transient_trig_exit(void) | |
230 | { | |
231 | led_trigger_unregister(&transient_trigger); | |
232 | } | |
233 | ||
234 | module_init(transient_trig_init); | |
235 | module_exit(transient_trig_exit); | |
236 | ||
237 | MODULE_AUTHOR("Shuah Khan <shuahkhan@gmail.com>"); | |
238 | MODULE_DESCRIPTION("Transient LED trigger"); | |
239 | MODULE_LICENSE("GPL"); |