Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Backlight Lowlevel Control Abstraction | |
3 | * | |
4 | * Copyright (C) 2003,2004 Hewlett-Packard Company | |
5 | * | |
6 | */ | |
7 | ||
1da177e4 LT |
8 | #include <linux/module.h> |
9 | #include <linux/init.h> | |
10 | #include <linux/device.h> | |
11 | #include <linux/backlight.h> | |
12 | #include <linux/notifier.h> | |
13 | #include <linux/ctype.h> | |
14 | #include <linux/err.h> | |
15 | #include <linux/fb.h> | |
1da177e4 LT |
16 | |
17 | static ssize_t backlight_show_power(struct class_device *cdev, char *buf) | |
18 | { | |
6ca01765 | 19 | int rc = -ENXIO; |
1da177e4 LT |
20 | struct backlight_device *bd = to_backlight_device(cdev); |
21 | ||
22 | down(&bd->sem); | |
6ca01765 RP |
23 | if (likely(bd->props)) |
24 | rc = sprintf(buf, "%d\n", bd->props->power); | |
1da177e4 LT |
25 | up(&bd->sem); |
26 | ||
27 | return rc; | |
28 | } | |
29 | ||
30 | static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count) | |
31 | { | |
68673afd | 32 | int rc = -ENXIO; |
1da177e4 LT |
33 | char *endp; |
34 | struct backlight_device *bd = to_backlight_device(cdev); | |
68673afd RP |
35 | int power = simple_strtoul(buf, &endp, 0); |
36 | size_t size = endp - buf; | |
1da177e4 | 37 | |
68673afd RP |
38 | if (*endp && isspace(*endp)) |
39 | size++; | |
40 | if (size != count) | |
1da177e4 LT |
41 | return -EINVAL; |
42 | ||
43 | down(&bd->sem); | |
6ca01765 | 44 | if (likely(bd->props)) { |
1da177e4 | 45 | pr_debug("backlight: set power to %d\n", power); |
6ca01765 RP |
46 | bd->props->power = power; |
47 | if (likely(bd->props->update_status)) | |
48 | bd->props->update_status(bd); | |
1da177e4 | 49 | rc = count; |
6ca01765 | 50 | } |
1da177e4 LT |
51 | up(&bd->sem); |
52 | ||
53 | return rc; | |
54 | } | |
55 | ||
56 | static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf) | |
57 | { | |
6ca01765 | 58 | int rc = -ENXIO; |
1da177e4 LT |
59 | struct backlight_device *bd = to_backlight_device(cdev); |
60 | ||
61 | down(&bd->sem); | |
6ca01765 RP |
62 | if (likely(bd->props)) |
63 | rc = sprintf(buf, "%d\n", bd->props->brightness); | |
1da177e4 LT |
64 | up(&bd->sem); |
65 | ||
66 | return rc; | |
67 | } | |
68 | ||
69 | static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count) | |
70 | { | |
68673afd | 71 | int rc = -ENXIO; |
1da177e4 LT |
72 | char *endp; |
73 | struct backlight_device *bd = to_backlight_device(cdev); | |
68673afd RP |
74 | int brightness = simple_strtoul(buf, &endp, 0); |
75 | size_t size = endp - buf; | |
1da177e4 | 76 | |
68673afd RP |
77 | if (*endp && isspace(*endp)) |
78 | size++; | |
79 | if (size != count) | |
1da177e4 LT |
80 | return -EINVAL; |
81 | ||
82 | down(&bd->sem); | |
6ca01765 RP |
83 | if (likely(bd->props)) { |
84 | if (brightness > bd->props->max_brightness) | |
85 | rc = -EINVAL; | |
86 | else { | |
87 | pr_debug("backlight: set brightness to %d\n", | |
88 | brightness); | |
89 | bd->props->brightness = brightness; | |
90 | if (likely(bd->props->update_status)) | |
91 | bd->props->update_status(bd); | |
92 | rc = count; | |
93 | } | |
94 | } | |
1da177e4 LT |
95 | up(&bd->sem); |
96 | ||
97 | return rc; | |
98 | } | |
99 | ||
100 | static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf) | |
101 | { | |
6ca01765 | 102 | int rc = -ENXIO; |
1da177e4 LT |
103 | struct backlight_device *bd = to_backlight_device(cdev); |
104 | ||
105 | down(&bd->sem); | |
106 | if (likely(bd->props)) | |
107 | rc = sprintf(buf, "%d\n", bd->props->max_brightness); | |
6ca01765 RP |
108 | up(&bd->sem); |
109 | ||
110 | return rc; | |
111 | } | |
112 | ||
113 | static ssize_t backlight_show_actual_brightness(struct class_device *cdev, | |
114 | char *buf) | |
115 | { | |
116 | int rc = -ENXIO; | |
117 | struct backlight_device *bd = to_backlight_device(cdev); | |
118 | ||
119 | down(&bd->sem); | |
120 | if (likely(bd->props && bd->props->get_brightness)) | |
121 | rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd)); | |
1da177e4 LT |
122 | up(&bd->sem); |
123 | ||
124 | return rc; | |
125 | } | |
126 | ||
127 | static void backlight_class_release(struct class_device *dev) | |
128 | { | |
129 | struct backlight_device *bd = to_backlight_device(dev); | |
130 | kfree(bd); | |
131 | } | |
132 | ||
133 | static struct class backlight_class = { | |
134 | .name = "backlight", | |
135 | .release = backlight_class_release, | |
136 | }; | |
137 | ||
138 | #define DECLARE_ATTR(_name,_mode,_show,_store) \ | |
139 | { \ | |
140 | .attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \ | |
141 | .show = _show, \ | |
142 | .store = _store, \ | |
143 | } | |
144 | ||
145 | static struct class_device_attribute bl_class_device_attributes[] = { | |
146 | DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power), | |
6ca01765 RP |
147 | DECLARE_ATTR(brightness, 0644, backlight_show_brightness, |
148 | backlight_store_brightness), | |
149 | DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness, | |
150 | NULL), | |
1da177e4 LT |
151 | DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL), |
152 | }; | |
153 | ||
154 | /* This callback gets called when something important happens inside a | |
155 | * framebuffer driver. We're looking if that important event is blanking, | |
156 | * and if it is, we're switching backlight power as well ... | |
157 | */ | |
158 | static int fb_notifier_callback(struct notifier_block *self, | |
159 | unsigned long event, void *data) | |
160 | { | |
161 | struct backlight_device *bd; | |
162 | struct fb_event *evdata =(struct fb_event *)data; | |
163 | ||
164 | /* If we aren't interested in this event, skip it immediately ... */ | |
165 | if (event != FB_EVENT_BLANK) | |
166 | return 0; | |
167 | ||
168 | bd = container_of(self, struct backlight_device, fb_notif); | |
169 | down(&bd->sem); | |
170 | if (bd->props) | |
6ca01765 RP |
171 | if (!bd->props->check_fb || |
172 | bd->props->check_fb(evdata->info)) { | |
173 | bd->props->fb_blank = *(int *)evdata->data; | |
174 | if (likely(bd->props && bd->props->update_status)) | |
175 | bd->props->update_status(bd); | |
176 | } | |
1da177e4 LT |
177 | up(&bd->sem); |
178 | return 0; | |
179 | } | |
180 | ||
181 | /** | |
182 | * backlight_device_register - create and register a new object of | |
183 | * backlight_device class. | |
184 | * @name: the name of the new object(must be the same as the name of the | |
185 | * respective framebuffer device). | |
186 | * @devdata: an optional pointer to be stored in the class_device. The | |
187 | * methods may retrieve it by using class_get_devdata(&bd->class_dev). | |
188 | * @bp: the backlight properties structure. | |
189 | * | |
190 | * Creates and registers new backlight class_device. Returns either an | |
191 | * ERR_PTR() or a pointer to the newly allocated device. | |
192 | */ | |
193 | struct backlight_device *backlight_device_register(const char *name, void *devdata, | |
194 | struct backlight_properties *bp) | |
195 | { | |
196 | int i, rc; | |
197 | struct backlight_device *new_bd; | |
198 | ||
199 | pr_debug("backlight_device_alloc: name=%s\n", name); | |
200 | ||
201 | new_bd = kmalloc(sizeof(struct backlight_device), GFP_KERNEL); | |
202 | if (unlikely(!new_bd)) | |
10ad1b73 | 203 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
204 | |
205 | init_MUTEX(&new_bd->sem); | |
206 | new_bd->props = bp; | |
207 | memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev)); | |
208 | new_bd->class_dev.class = &backlight_class; | |
209 | strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN); | |
210 | class_set_devdata(&new_bd->class_dev, devdata); | |
211 | ||
212 | rc = class_device_register(&new_bd->class_dev); | |
213 | if (unlikely(rc)) { | |
214 | error: kfree(new_bd); | |
215 | return ERR_PTR(rc); | |
216 | } | |
217 | ||
218 | memset(&new_bd->fb_notif, 0, sizeof(new_bd->fb_notif)); | |
219 | new_bd->fb_notif.notifier_call = fb_notifier_callback; | |
220 | ||
221 | rc = fb_register_client(&new_bd->fb_notif); | |
222 | if (unlikely(rc)) | |
223 | goto error; | |
224 | ||
225 | for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) { | |
226 | rc = class_device_create_file(&new_bd->class_dev, | |
227 | &bl_class_device_attributes[i]); | |
228 | if (unlikely(rc)) { | |
229 | while (--i >= 0) | |
230 | class_device_remove_file(&new_bd->class_dev, | |
231 | &bl_class_device_attributes[i]); | |
232 | class_device_unregister(&new_bd->class_dev); | |
233 | /* No need to kfree(new_bd) since release() method was called */ | |
234 | return ERR_PTR(rc); | |
235 | } | |
236 | } | |
237 | ||
238 | return new_bd; | |
239 | } | |
240 | EXPORT_SYMBOL(backlight_device_register); | |
241 | ||
242 | /** | |
243 | * backlight_device_unregister - unregisters a backlight device object. | |
244 | * @bd: the backlight device object to be unregistered and freed. | |
245 | * | |
246 | * Unregisters a previously registered via backlight_device_register object. | |
247 | */ | |
248 | void backlight_device_unregister(struct backlight_device *bd) | |
249 | { | |
250 | int i; | |
251 | ||
252 | if (!bd) | |
253 | return; | |
254 | ||
255 | pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id); | |
256 | ||
257 | for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) | |
258 | class_device_remove_file(&bd->class_dev, | |
259 | &bl_class_device_attributes[i]); | |
260 | ||
261 | down(&bd->sem); | |
6ca01765 RP |
262 | if (likely(bd->props && bd->props->update_status)) { |
263 | bd->props->brightness = 0; | |
264 | bd->props->power = 0; | |
265 | bd->props->update_status(bd); | |
266 | } | |
267 | ||
1da177e4 LT |
268 | bd->props = NULL; |
269 | up(&bd->sem); | |
270 | ||
271 | fb_unregister_client(&bd->fb_notif); | |
272 | ||
273 | class_device_unregister(&bd->class_dev); | |
274 | } | |
275 | EXPORT_SYMBOL(backlight_device_unregister); | |
276 | ||
277 | static void __exit backlight_class_exit(void) | |
278 | { | |
279 | class_unregister(&backlight_class); | |
280 | } | |
281 | ||
282 | static int __init backlight_class_init(void) | |
283 | { | |
284 | return class_register(&backlight_class); | |
285 | } | |
286 | ||
287 | /* | |
288 | * if this is compiled into the kernel, we need to ensure that the | |
289 | * class is registered before users of the class try to register lcd's | |
290 | */ | |
291 | postcore_initcall(backlight_class_init); | |
292 | module_exit(backlight_class_exit); | |
293 | ||
294 | MODULE_LICENSE("GPL"); | |
295 | MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>"); | |
296 | MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction"); |