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 | 16 | |
3d5eeadd JS |
17 | |
18 | #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \ | |
19 | defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)) | |
20 | /* This callback gets called when something important happens inside a | |
21 | * framebuffer driver. We're looking if that important event is blanking, | |
22 | * and if it is, we're switching backlight power as well ... | |
23 | */ | |
24 | static int fb_notifier_callback(struct notifier_block *self, | |
25 | unsigned long event, void *data) | |
26 | { | |
27 | struct backlight_device *bd; | |
28 | struct fb_event *evdata = data; | |
29 | ||
30 | /* If we aren't interested in this event, skip it immediately ... */ | |
31 | if (event != FB_EVENT_BLANK) | |
32 | return 0; | |
33 | ||
34 | bd = container_of(self, struct backlight_device, fb_notif); | |
35 | down(&bd->sem); | |
36 | if (bd->props) | |
37 | if (!bd->props->check_fb || | |
38 | bd->props->check_fb(evdata->info)) { | |
39 | bd->props->fb_blank = *(int *)evdata->data; | |
40 | if (likely(bd->props && bd->props->update_status)) | |
41 | bd->props->update_status(bd); | |
42 | } | |
43 | up(&bd->sem); | |
44 | return 0; | |
45 | } | |
46 | ||
47 | static int backlight_register_fb(struct backlight_device *bd) | |
48 | { | |
49 | memset(&bd->fb_notif, 0, sizeof(bd->fb_notif)); | |
50 | bd->fb_notif.notifier_call = fb_notifier_callback; | |
51 | ||
52 | return fb_register_client(&bd->fb_notif); | |
53 | } | |
54 | ||
55 | static void backlight_unregister_fb(struct backlight_device *bd) | |
56 | { | |
57 | fb_unregister_client(&bd->fb_notif); | |
58 | } | |
59 | #else | |
60 | static inline int backlight_register_fb(struct backlight_device *bd) | |
61 | { | |
62 | return 0; | |
63 | } | |
64 | ||
65 | static inline void backlight_unregister_fb(struct backlight_device *bd) | |
66 | { | |
67 | } | |
68 | #endif /* CONFIG_FB */ | |
69 | ||
1da177e4 LT |
70 | static ssize_t backlight_show_power(struct class_device *cdev, char *buf) |
71 | { | |
6ca01765 | 72 | int rc = -ENXIO; |
1da177e4 LT |
73 | struct backlight_device *bd = to_backlight_device(cdev); |
74 | ||
75 | down(&bd->sem); | |
6ca01765 RP |
76 | if (likely(bd->props)) |
77 | rc = sprintf(buf, "%d\n", bd->props->power); | |
1da177e4 LT |
78 | up(&bd->sem); |
79 | ||
80 | return rc; | |
81 | } | |
82 | ||
83 | static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count) | |
84 | { | |
68673afd | 85 | int rc = -ENXIO; |
1da177e4 LT |
86 | char *endp; |
87 | struct backlight_device *bd = to_backlight_device(cdev); | |
68673afd RP |
88 | int power = simple_strtoul(buf, &endp, 0); |
89 | size_t size = endp - buf; | |
1da177e4 | 90 | |
68673afd RP |
91 | if (*endp && isspace(*endp)) |
92 | size++; | |
93 | if (size != count) | |
1da177e4 LT |
94 | return -EINVAL; |
95 | ||
96 | down(&bd->sem); | |
6ca01765 | 97 | if (likely(bd->props)) { |
1da177e4 | 98 | pr_debug("backlight: set power to %d\n", power); |
6ca01765 RP |
99 | bd->props->power = power; |
100 | if (likely(bd->props->update_status)) | |
101 | bd->props->update_status(bd); | |
1da177e4 | 102 | rc = count; |
6ca01765 | 103 | } |
1da177e4 LT |
104 | up(&bd->sem); |
105 | ||
106 | return rc; | |
107 | } | |
108 | ||
109 | static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf) | |
110 | { | |
6ca01765 | 111 | int rc = -ENXIO; |
1da177e4 LT |
112 | struct backlight_device *bd = to_backlight_device(cdev); |
113 | ||
114 | down(&bd->sem); | |
6ca01765 RP |
115 | if (likely(bd->props)) |
116 | rc = sprintf(buf, "%d\n", bd->props->brightness); | |
1da177e4 LT |
117 | up(&bd->sem); |
118 | ||
119 | return rc; | |
120 | } | |
121 | ||
122 | static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count) | |
123 | { | |
68673afd | 124 | int rc = -ENXIO; |
1da177e4 LT |
125 | char *endp; |
126 | struct backlight_device *bd = to_backlight_device(cdev); | |
68673afd RP |
127 | int brightness = simple_strtoul(buf, &endp, 0); |
128 | size_t size = endp - buf; | |
1da177e4 | 129 | |
68673afd RP |
130 | if (*endp && isspace(*endp)) |
131 | size++; | |
132 | if (size != count) | |
1da177e4 LT |
133 | return -EINVAL; |
134 | ||
135 | down(&bd->sem); | |
6ca01765 RP |
136 | if (likely(bd->props)) { |
137 | if (brightness > bd->props->max_brightness) | |
138 | rc = -EINVAL; | |
139 | else { | |
140 | pr_debug("backlight: set brightness to %d\n", | |
141 | brightness); | |
142 | bd->props->brightness = brightness; | |
143 | if (likely(bd->props->update_status)) | |
144 | bd->props->update_status(bd); | |
145 | rc = count; | |
146 | } | |
147 | } | |
1da177e4 LT |
148 | up(&bd->sem); |
149 | ||
150 | return rc; | |
151 | } | |
152 | ||
153 | static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf) | |
154 | { | |
6ca01765 | 155 | int rc = -ENXIO; |
1da177e4 LT |
156 | struct backlight_device *bd = to_backlight_device(cdev); |
157 | ||
158 | down(&bd->sem); | |
159 | if (likely(bd->props)) | |
160 | rc = sprintf(buf, "%d\n", bd->props->max_brightness); | |
6ca01765 RP |
161 | up(&bd->sem); |
162 | ||
163 | return rc; | |
164 | } | |
165 | ||
166 | static ssize_t backlight_show_actual_brightness(struct class_device *cdev, | |
167 | char *buf) | |
168 | { | |
169 | int rc = -ENXIO; | |
170 | struct backlight_device *bd = to_backlight_device(cdev); | |
171 | ||
172 | down(&bd->sem); | |
173 | if (likely(bd->props && bd->props->get_brightness)) | |
174 | rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd)); | |
1da177e4 LT |
175 | up(&bd->sem); |
176 | ||
177 | return rc; | |
178 | } | |
179 | ||
180 | static void backlight_class_release(struct class_device *dev) | |
181 | { | |
182 | struct backlight_device *bd = to_backlight_device(dev); | |
183 | kfree(bd); | |
184 | } | |
185 | ||
186 | static struct class backlight_class = { | |
187 | .name = "backlight", | |
188 | .release = backlight_class_release, | |
189 | }; | |
190 | ||
191 | #define DECLARE_ATTR(_name,_mode,_show,_store) \ | |
192 | { \ | |
193 | .attr = { .name = __stringify(_name), .mode = _mode, .owner = THIS_MODULE }, \ | |
194 | .show = _show, \ | |
195 | .store = _store, \ | |
196 | } | |
197 | ||
d95159cf | 198 | static const struct class_device_attribute bl_class_device_attributes[] = { |
1da177e4 | 199 | DECLARE_ATTR(power, 0644, backlight_show_power, backlight_store_power), |
6ca01765 RP |
200 | DECLARE_ATTR(brightness, 0644, backlight_show_brightness, |
201 | backlight_store_brightness), | |
202 | DECLARE_ATTR(actual_brightness, 0444, backlight_show_actual_brightness, | |
203 | NULL), | |
1da177e4 LT |
204 | DECLARE_ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL), |
205 | }; | |
206 | ||
1da177e4 LT |
207 | /** |
208 | * backlight_device_register - create and register a new object of | |
209 | * backlight_device class. | |
210 | * @name: the name of the new object(must be the same as the name of the | |
211 | * respective framebuffer device). | |
212 | * @devdata: an optional pointer to be stored in the class_device. The | |
213 | * methods may retrieve it by using class_get_devdata(&bd->class_dev). | |
214 | * @bp: the backlight properties structure. | |
215 | * | |
216 | * Creates and registers new backlight class_device. Returns either an | |
217 | * ERR_PTR() or a pointer to the newly allocated device. | |
218 | */ | |
519ab5f2 YL |
219 | struct backlight_device *backlight_device_register(const char *name, |
220 | struct device *dev, | |
221 | void *devdata, | |
222 | struct backlight_properties *bp) | |
1da177e4 LT |
223 | { |
224 | int i, rc; | |
225 | struct backlight_device *new_bd; | |
226 | ||
227 | pr_debug("backlight_device_alloc: name=%s\n", name); | |
228 | ||
229 | new_bd = kmalloc(sizeof(struct backlight_device), GFP_KERNEL); | |
230 | if (unlikely(!new_bd)) | |
10ad1b73 | 231 | return ERR_PTR(-ENOMEM); |
1da177e4 LT |
232 | |
233 | init_MUTEX(&new_bd->sem); | |
234 | new_bd->props = bp; | |
235 | memset(&new_bd->class_dev, 0, sizeof(new_bd->class_dev)); | |
236 | new_bd->class_dev.class = &backlight_class; | |
519ab5f2 | 237 | new_bd->class_dev.dev = dev; |
1da177e4 LT |
238 | strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN); |
239 | class_set_devdata(&new_bd->class_dev, devdata); | |
240 | ||
241 | rc = class_device_register(&new_bd->class_dev); | |
242 | if (unlikely(rc)) { | |
243 | error: kfree(new_bd); | |
244 | return ERR_PTR(rc); | |
245 | } | |
246 | ||
3d5eeadd | 247 | rc = backlight_register_fb(new_bd); |
1da177e4 LT |
248 | if (unlikely(rc)) |
249 | goto error; | |
250 | ||
251 | for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) { | |
252 | rc = class_device_create_file(&new_bd->class_dev, | |
253 | &bl_class_device_attributes[i]); | |
254 | if (unlikely(rc)) { | |
255 | while (--i >= 0) | |
256 | class_device_remove_file(&new_bd->class_dev, | |
257 | &bl_class_device_attributes[i]); | |
258 | class_device_unregister(&new_bd->class_dev); | |
259 | /* No need to kfree(new_bd) since release() method was called */ | |
260 | return ERR_PTR(rc); | |
261 | } | |
262 | } | |
263 | ||
264 | return new_bd; | |
265 | } | |
266 | EXPORT_SYMBOL(backlight_device_register); | |
267 | ||
268 | /** | |
269 | * backlight_device_unregister - unregisters a backlight device object. | |
270 | * @bd: the backlight device object to be unregistered and freed. | |
271 | * | |
272 | * Unregisters a previously registered via backlight_device_register object. | |
273 | */ | |
274 | void backlight_device_unregister(struct backlight_device *bd) | |
275 | { | |
276 | int i; | |
277 | ||
278 | if (!bd) | |
279 | return; | |
280 | ||
281 | pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id); | |
282 | ||
283 | for (i = 0; i < ARRAY_SIZE(bl_class_device_attributes); i++) | |
284 | class_device_remove_file(&bd->class_dev, | |
285 | &bl_class_device_attributes[i]); | |
286 | ||
287 | down(&bd->sem); | |
288 | bd->props = NULL; | |
289 | up(&bd->sem); | |
290 | ||
3d5eeadd | 291 | backlight_unregister_fb(bd); |
1da177e4 LT |
292 | |
293 | class_device_unregister(&bd->class_dev); | |
294 | } | |
295 | EXPORT_SYMBOL(backlight_device_unregister); | |
296 | ||
297 | static void __exit backlight_class_exit(void) | |
298 | { | |
299 | class_unregister(&backlight_class); | |
300 | } | |
301 | ||
302 | static int __init backlight_class_init(void) | |
303 | { | |
304 | return class_register(&backlight_class); | |
305 | } | |
306 | ||
307 | /* | |
308 | * if this is compiled into the kernel, we need to ensure that the | |
309 | * class is registered before users of the class try to register lcd's | |
310 | */ | |
311 | postcore_initcall(backlight_class_init); | |
312 | module_exit(backlight_class_exit); | |
313 | ||
314 | MODULE_LICENSE("GPL"); | |
315 | MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>"); | |
316 | MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction"); |