Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Backlight Lowlevel Control Abstraction | |
3 | * | |
4 | * Copyright (C) 2003,2004 Hewlett-Packard Company | |
5 | * | |
6 | */ | |
7 | ||
35f96162 JH |
8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
9 | ||
1da177e4 LT |
10 | #include <linux/module.h> |
11 | #include <linux/init.h> | |
12 | #include <linux/device.h> | |
13 | #include <linux/backlight.h> | |
14 | #include <linux/notifier.h> | |
15 | #include <linux/ctype.h> | |
16 | #include <linux/err.h> | |
17 | #include <linux/fb.h> | |
5a0e3ad6 | 18 | #include <linux/slab.h> |
1da177e4 | 19 | |
321709c5 RP |
20 | #ifdef CONFIG_PMAC_BACKLIGHT |
21 | #include <asm/backlight.h> | |
22 | #endif | |
3d5eeadd | 23 | |
c338bfb5 | 24 | static const char *const backlight_types[] = { |
bb7ca747 MG |
25 | [BACKLIGHT_RAW] = "raw", |
26 | [BACKLIGHT_PLATFORM] = "platform", | |
27 | [BACKLIGHT_FIRMWARE] = "firmware", | |
28 | }; | |
29 | ||
3d5eeadd JS |
30 | #if defined(CONFIG_FB) || (defined(CONFIG_FB_MODULE) && \ |
31 | defined(CONFIG_BACKLIGHT_CLASS_DEVICE_MODULE)) | |
32 | /* This callback gets called when something important happens inside a | |
33 | * framebuffer driver. We're looking if that important event is blanking, | |
34 | * and if it is, we're switching backlight power as well ... | |
35 | */ | |
36 | static int fb_notifier_callback(struct notifier_block *self, | |
37 | unsigned long event, void *data) | |
38 | { | |
39 | struct backlight_device *bd; | |
40 | struct fb_event *evdata = data; | |
41 | ||
42 | /* If we aren't interested in this event, skip it immediately ... */ | |
994efacd | 43 | if (event != FB_EVENT_BLANK && event != FB_EVENT_CONBLANK) |
3d5eeadd JS |
44 | return 0; |
45 | ||
46 | bd = container_of(self, struct backlight_device, fb_notif); | |
599a52d1 RP |
47 | mutex_lock(&bd->ops_lock); |
48 | if (bd->ops) | |
49 | if (!bd->ops->check_fb || | |
57e148b6 | 50 | bd->ops->check_fb(bd, evdata->info)) { |
599a52d1 | 51 | bd->props.fb_blank = *(int *)evdata->data; |
c835ee7f RP |
52 | if (bd->props.fb_blank == FB_BLANK_UNBLANK) |
53 | bd->props.state &= ~BL_CORE_FBBLANK; | |
54 | else | |
55 | bd->props.state |= BL_CORE_FBBLANK; | |
28ee086d | 56 | backlight_update_status(bd); |
3d5eeadd | 57 | } |
599a52d1 | 58 | mutex_unlock(&bd->ops_lock); |
3d5eeadd JS |
59 | return 0; |
60 | } | |
61 | ||
62 | static int backlight_register_fb(struct backlight_device *bd) | |
63 | { | |
64 | memset(&bd->fb_notif, 0, sizeof(bd->fb_notif)); | |
65 | bd->fb_notif.notifier_call = fb_notifier_callback; | |
66 | ||
67 | return fb_register_client(&bd->fb_notif); | |
68 | } | |
69 | ||
70 | static void backlight_unregister_fb(struct backlight_device *bd) | |
71 | { | |
72 | fb_unregister_client(&bd->fb_notif); | |
73 | } | |
74 | #else | |
75 | static inline int backlight_register_fb(struct backlight_device *bd) | |
76 | { | |
77 | return 0; | |
78 | } | |
79 | ||
80 | static inline void backlight_unregister_fb(struct backlight_device *bd) | |
81 | { | |
82 | } | |
83 | #endif /* CONFIG_FB */ | |
84 | ||
325253a6 MG |
85 | static void backlight_generate_event(struct backlight_device *bd, |
86 | enum backlight_update_reason reason) | |
87 | { | |
88 | char *envp[2]; | |
89 | ||
90 | switch (reason) { | |
91 | case BACKLIGHT_UPDATE_SYSFS: | |
92 | envp[0] = "SOURCE=sysfs"; | |
93 | break; | |
94 | case BACKLIGHT_UPDATE_HOTKEY: | |
95 | envp[0] = "SOURCE=hotkey"; | |
96 | break; | |
97 | default: | |
98 | envp[0] = "SOURCE=unknown"; | |
99 | break; | |
100 | } | |
101 | envp[1] = NULL; | |
102 | kobject_uevent_env(&bd->dev.kobj, KOBJ_CHANGE, envp); | |
89dfc28c | 103 | sysfs_notify(&bd->dev.kobj, NULL, "actual_brightness"); |
325253a6 MG |
104 | } |
105 | ||
655bfd7a | 106 | static ssize_t backlight_show_power(struct device *dev, |
66655760 | 107 | struct device_attribute *attr, char *buf) |
1da177e4 | 108 | { |
655bfd7a | 109 | struct backlight_device *bd = to_backlight_device(dev); |
1da177e4 | 110 | |
599a52d1 | 111 | return sprintf(buf, "%d\n", bd->props.power); |
1da177e4 LT |
112 | } |
113 | ||
655bfd7a RP |
114 | static ssize_t backlight_store_power(struct device *dev, |
115 | struct device_attribute *attr, const char *buf, size_t count) | |
1da177e4 | 116 | { |
9a2c61a9 | 117 | int rc; |
655bfd7a | 118 | struct backlight_device *bd = to_backlight_device(dev); |
9a2c61a9 | 119 | unsigned long power; |
1da177e4 | 120 | |
66655760 | 121 | rc = kstrtoul(buf, 0, &power); |
9a2c61a9 PM |
122 | if (rc) |
123 | return rc; | |
1da177e4 | 124 | |
9a2c61a9 | 125 | rc = -ENXIO; |
599a52d1 RP |
126 | mutex_lock(&bd->ops_lock); |
127 | if (bd->ops) { | |
35f96162 | 128 | pr_debug("set power to %lu\n", power); |
51552453 HD |
129 | if (bd->props.power != power) { |
130 | bd->props.power = power; | |
131 | backlight_update_status(bd); | |
132 | } | |
1da177e4 | 133 | rc = count; |
6ca01765 | 134 | } |
599a52d1 | 135 | mutex_unlock(&bd->ops_lock); |
1da177e4 LT |
136 | |
137 | return rc; | |
138 | } | |
139 | ||
655bfd7a RP |
140 | static ssize_t backlight_show_brightness(struct device *dev, |
141 | struct device_attribute *attr, char *buf) | |
1da177e4 | 142 | { |
655bfd7a | 143 | struct backlight_device *bd = to_backlight_device(dev); |
1da177e4 | 144 | |
599a52d1 | 145 | return sprintf(buf, "%d\n", bd->props.brightness); |
1da177e4 LT |
146 | } |
147 | ||
655bfd7a RP |
148 | static ssize_t backlight_store_brightness(struct device *dev, |
149 | struct device_attribute *attr, const char *buf, size_t count) | |
1da177e4 | 150 | { |
9a2c61a9 | 151 | int rc; |
655bfd7a | 152 | struct backlight_device *bd = to_backlight_device(dev); |
9a2c61a9 | 153 | unsigned long brightness; |
1da177e4 | 154 | |
66655760 | 155 | rc = kstrtoul(buf, 0, &brightness); |
9a2c61a9 PM |
156 | if (rc) |
157 | return rc; | |
158 | ||
159 | rc = -ENXIO; | |
1da177e4 | 160 | |
599a52d1 RP |
161 | mutex_lock(&bd->ops_lock); |
162 | if (bd->ops) { | |
163 | if (brightness > bd->props.max_brightness) | |
6ca01765 RP |
164 | rc = -EINVAL; |
165 | else { | |
35f96162 | 166 | pr_debug("set brightness to %lu\n", brightness); |
9be1df98 ZR |
167 | bd->props.brightness = brightness; |
168 | backlight_update_status(bd); | |
6ca01765 RP |
169 | rc = count; |
170 | } | |
171 | } | |
599a52d1 | 172 | mutex_unlock(&bd->ops_lock); |
1da177e4 | 173 | |
325253a6 MG |
174 | backlight_generate_event(bd, BACKLIGHT_UPDATE_SYSFS); |
175 | ||
1da177e4 LT |
176 | return rc; |
177 | } | |
178 | ||
bb7ca747 MG |
179 | static ssize_t backlight_show_type(struct device *dev, |
180 | struct device_attribute *attr, char *buf) | |
181 | { | |
182 | struct backlight_device *bd = to_backlight_device(dev); | |
183 | ||
184 | return sprintf(buf, "%s\n", backlight_types[bd->props.type]); | |
185 | } | |
186 | ||
655bfd7a RP |
187 | static ssize_t backlight_show_max_brightness(struct device *dev, |
188 | struct device_attribute *attr, char *buf) | |
1da177e4 | 189 | { |
655bfd7a | 190 | struct backlight_device *bd = to_backlight_device(dev); |
1da177e4 | 191 | |
599a52d1 | 192 | return sprintf(buf, "%d\n", bd->props.max_brightness); |
6ca01765 RP |
193 | } |
194 | ||
655bfd7a RP |
195 | static ssize_t backlight_show_actual_brightness(struct device *dev, |
196 | struct device_attribute *attr, char *buf) | |
6ca01765 RP |
197 | { |
198 | int rc = -ENXIO; | |
655bfd7a | 199 | struct backlight_device *bd = to_backlight_device(dev); |
6ca01765 | 200 | |
599a52d1 RP |
201 | mutex_lock(&bd->ops_lock); |
202 | if (bd->ops && bd->ops->get_brightness) | |
203 | rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd)); | |
204 | mutex_unlock(&bd->ops_lock); | |
1da177e4 LT |
205 | |
206 | return rc; | |
207 | } | |
208 | ||
0ad90efd | 209 | static struct class *backlight_class; |
655bfd7a | 210 | |
3601792e SK |
211 | #ifdef CONFIG_PM_SLEEP |
212 | static int backlight_suspend(struct device *dev) | |
c835ee7f RP |
213 | { |
214 | struct backlight_device *bd = to_backlight_device(dev); | |
215 | ||
d1d73578 UKK |
216 | mutex_lock(&bd->ops_lock); |
217 | if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) { | |
c835ee7f RP |
218 | bd->props.state |= BL_CORE_SUSPENDED; |
219 | backlight_update_status(bd); | |
c835ee7f | 220 | } |
d1d73578 | 221 | mutex_unlock(&bd->ops_lock); |
c835ee7f RP |
222 | |
223 | return 0; | |
224 | } | |
225 | ||
226 | static int backlight_resume(struct device *dev) | |
227 | { | |
228 | struct backlight_device *bd = to_backlight_device(dev); | |
229 | ||
d1d73578 UKK |
230 | mutex_lock(&bd->ops_lock); |
231 | if (bd->ops && bd->ops->options & BL_CORE_SUSPENDRESUME) { | |
c835ee7f RP |
232 | bd->props.state &= ~BL_CORE_SUSPENDED; |
233 | backlight_update_status(bd); | |
c835ee7f | 234 | } |
d1d73578 | 235 | mutex_unlock(&bd->ops_lock); |
c835ee7f RP |
236 | |
237 | return 0; | |
238 | } | |
3601792e SK |
239 | #endif |
240 | ||
241 | static SIMPLE_DEV_PM_OPS(backlight_class_dev_pm_ops, backlight_suspend, | |
242 | backlight_resume); | |
c835ee7f | 243 | |
655bfd7a | 244 | static void bl_device_release(struct device *dev) |
1da177e4 LT |
245 | { |
246 | struct backlight_device *bd = to_backlight_device(dev); | |
247 | kfree(bd); | |
248 | } | |
249 | ||
655bfd7a RP |
250 | static struct device_attribute bl_device_attributes[] = { |
251 | __ATTR(bl_power, 0644, backlight_show_power, backlight_store_power), | |
252 | __ATTR(brightness, 0644, backlight_show_brightness, | |
6ca01765 | 253 | backlight_store_brightness), |
655bfd7a | 254 | __ATTR(actual_brightness, 0444, backlight_show_actual_brightness, |
6ca01765 | 255 | NULL), |
655bfd7a | 256 | __ATTR(max_brightness, 0444, backlight_show_max_brightness, NULL), |
bb7ca747 | 257 | __ATTR(type, 0444, backlight_show_type, NULL), |
655bfd7a | 258 | __ATTR_NULL, |
1da177e4 LT |
259 | }; |
260 | ||
325253a6 MG |
261 | /** |
262 | * backlight_force_update - tell the backlight subsystem that hardware state | |
263 | * has changed | |
264 | * @bd: the backlight device to update | |
265 | * | |
266 | * Updates the internal state of the backlight in response to a hardware event, | |
267 | * and generate a uevent to notify userspace | |
268 | */ | |
269 | void backlight_force_update(struct backlight_device *bd, | |
270 | enum backlight_update_reason reason) | |
271 | { | |
272 | mutex_lock(&bd->ops_lock); | |
273 | if (bd->ops && bd->ops->get_brightness) | |
274 | bd->props.brightness = bd->ops->get_brightness(bd); | |
275 | mutex_unlock(&bd->ops_lock); | |
276 | backlight_generate_event(bd, reason); | |
277 | } | |
278 | EXPORT_SYMBOL(backlight_force_update); | |
279 | ||
1da177e4 LT |
280 | /** |
281 | * backlight_device_register - create and register a new object of | |
282 | * backlight_device class. | |
283 | * @name: the name of the new object(must be the same as the name of the | |
284 | * respective framebuffer device). | |
f6ec2d96 | 285 | * @parent: a pointer to the parent device |
655bfd7a RP |
286 | * @devdata: an optional pointer to be stored for private driver use. The |
287 | * methods may retrieve it by using bl_get_data(bd). | |
599a52d1 | 288 | * @ops: the backlight operations structure. |
1da177e4 | 289 | * |
655bfd7a | 290 | * Creates and registers new backlight device. Returns either an |
1da177e4 LT |
291 | * ERR_PTR() or a pointer to the newly allocated device. |
292 | */ | |
519ab5f2 | 293 | struct backlight_device *backlight_device_register(const char *name, |
a19a6ee6 MG |
294 | struct device *parent, void *devdata, const struct backlight_ops *ops, |
295 | const struct backlight_properties *props) | |
1da177e4 | 296 | { |
1da177e4 | 297 | struct backlight_device *new_bd; |
655bfd7a | 298 | int rc; |
1da177e4 | 299 | |
655bfd7a | 300 | pr_debug("backlight_device_register: name=%s\n", name); |
1da177e4 | 301 | |
599a52d1 | 302 | new_bd = kzalloc(sizeof(struct backlight_device), GFP_KERNEL); |
90968e8e | 303 | if (!new_bd) |
10ad1b73 | 304 | return ERR_PTR(-ENOMEM); |
1da177e4 | 305 | |
28ee086d | 306 | mutex_init(&new_bd->update_lock); |
599a52d1 | 307 | mutex_init(&new_bd->ops_lock); |
1da177e4 | 308 | |
655bfd7a RP |
309 | new_bd->dev.class = backlight_class; |
310 | new_bd->dev.parent = parent; | |
311 | new_bd->dev.release = bl_device_release; | |
02aa2a37 | 312 | dev_set_name(&new_bd->dev, "%s", name); |
655bfd7a RP |
313 | dev_set_drvdata(&new_bd->dev, devdata); |
314 | ||
a19a6ee6 | 315 | /* Set default properties */ |
bb7ca747 | 316 | if (props) { |
a19a6ee6 MG |
317 | memcpy(&new_bd->props, props, |
318 | sizeof(struct backlight_properties)); | |
bb7ca747 MG |
319 | if (props->type <= 0 || props->type >= BACKLIGHT_TYPE_MAX) { |
320 | WARN(1, "%s: invalid backlight type", name); | |
321 | new_bd->props.type = BACKLIGHT_RAW; | |
322 | } | |
323 | } else { | |
324 | new_bd->props.type = BACKLIGHT_RAW; | |
325 | } | |
a19a6ee6 | 326 | |
655bfd7a | 327 | rc = device_register(&new_bd->dev); |
90968e8e | 328 | if (rc) { |
2fd5a154 | 329 | kfree(new_bd); |
1da177e4 LT |
330 | return ERR_PTR(rc); |
331 | } | |
332 | ||
3d5eeadd | 333 | rc = backlight_register_fb(new_bd); |
2fd5a154 | 334 | if (rc) { |
655bfd7a | 335 | device_unregister(&new_bd->dev); |
2fd5a154 DT |
336 | return ERR_PTR(rc); |
337 | } | |
338 | ||
655bfd7a | 339 | new_bd->ops = ops; |
1da177e4 | 340 | |
321709c5 RP |
341 | #ifdef CONFIG_PMAC_BACKLIGHT |
342 | mutex_lock(&pmac_backlight_mutex); | |
343 | if (!pmac_backlight) | |
344 | pmac_backlight = new_bd; | |
345 | mutex_unlock(&pmac_backlight_mutex); | |
346 | #endif | |
347 | ||
1da177e4 LT |
348 | return new_bd; |
349 | } | |
350 | EXPORT_SYMBOL(backlight_device_register); | |
351 | ||
352 | /** | |
353 | * backlight_device_unregister - unregisters a backlight device object. | |
354 | * @bd: the backlight device object to be unregistered and freed. | |
355 | * | |
356 | * Unregisters a previously registered via backlight_device_register object. | |
357 | */ | |
358 | void backlight_device_unregister(struct backlight_device *bd) | |
359 | { | |
1da177e4 LT |
360 | if (!bd) |
361 | return; | |
362 | ||
321709c5 RP |
363 | #ifdef CONFIG_PMAC_BACKLIGHT |
364 | mutex_lock(&pmac_backlight_mutex); | |
365 | if (pmac_backlight == bd) | |
366 | pmac_backlight = NULL; | |
367 | mutex_unlock(&pmac_backlight_mutex); | |
368 | #endif | |
599a52d1 RP |
369 | mutex_lock(&bd->ops_lock); |
370 | bd->ops = NULL; | |
371 | mutex_unlock(&bd->ops_lock); | |
1da177e4 | 372 | |
3d5eeadd | 373 | backlight_unregister_fb(bd); |
655bfd7a | 374 | device_unregister(&bd->dev); |
1da177e4 LT |
375 | } |
376 | EXPORT_SYMBOL(backlight_device_unregister); | |
377 | ||
8318fde4 JH |
378 | static void devm_backlight_device_release(struct device *dev, void *res) |
379 | { | |
380 | struct backlight_device *backlight = *(struct backlight_device **)res; | |
381 | ||
382 | backlight_device_unregister(backlight); | |
383 | } | |
384 | ||
385 | static int devm_backlight_device_match(struct device *dev, void *res, | |
386 | void *data) | |
387 | { | |
388 | struct backlight_device **r = res; | |
389 | ||
390 | return *r == data; | |
391 | } | |
392 | ||
393 | /** | |
394 | * devm_backlight_device_register - resource managed backlight_device_register() | |
395 | * @dev: the device to register | |
396 | * @name: the name of the device | |
397 | * @parent: a pointer to the parent device | |
398 | * @devdata: an optional pointer to be stored for private driver use | |
399 | * @ops: the backlight operations structure | |
400 | * @props: the backlight properties | |
401 | * | |
402 | * @return a struct backlight on success, or an ERR_PTR on error | |
403 | * | |
404 | * Managed backlight_device_register(). The backlight_device returned | |
405 | * from this function are automatically freed on driver detach. | |
406 | * See backlight_device_register() for more information. | |
407 | */ | |
408 | struct backlight_device *devm_backlight_device_register(struct device *dev, | |
409 | const char *name, struct device *parent, void *devdata, | |
410 | const struct backlight_ops *ops, | |
411 | const struct backlight_properties *props) | |
412 | { | |
413 | struct backlight_device **ptr, *backlight; | |
414 | ||
415 | ptr = devres_alloc(devm_backlight_device_release, sizeof(*ptr), | |
416 | GFP_KERNEL); | |
417 | if (!ptr) | |
418 | return ERR_PTR(-ENOMEM); | |
419 | ||
420 | backlight = backlight_device_register(name, parent, devdata, ops, | |
421 | props); | |
422 | if (!IS_ERR(backlight)) { | |
423 | *ptr = backlight; | |
424 | devres_add(dev, ptr); | |
425 | } else { | |
426 | devres_free(ptr); | |
427 | } | |
428 | ||
429 | return backlight; | |
430 | } | |
431 | EXPORT_SYMBOL(devm_backlight_device_register); | |
432 | ||
433 | /** | |
434 | * devm_backlight_device_unregister - resource managed backlight_device_unregister() | |
435 | * @dev: the device to unregister | |
436 | * @bd: the backlight device to unregister | |
437 | * | |
438 | * Deallocated a backlight allocated with devm_backlight_device_register(). | |
439 | * Normally this function will not need to be called and the resource management | |
440 | * code will ensure that the resource is freed. | |
441 | */ | |
442 | void devm_backlight_device_unregister(struct device *dev, | |
443 | struct backlight_device *bd) | |
444 | { | |
445 | int rc; | |
446 | ||
447 | rc = devres_release(dev, devm_backlight_device_release, | |
448 | devm_backlight_device_match, bd); | |
449 | WARN_ON(rc); | |
450 | } | |
451 | EXPORT_SYMBOL(devm_backlight_device_unregister); | |
452 | ||
762a936f | 453 | #ifdef CONFIG_OF |
3213f631 | 454 | static int of_parent_match(struct device *dev, const void *data) |
762a936f TR |
455 | { |
456 | return dev->parent && dev->parent->of_node == data; | |
457 | } | |
458 | ||
459 | /** | |
460 | * of_find_backlight_by_node() - find backlight device by device-tree node | |
461 | * @node: device-tree node of the backlight device | |
462 | * | |
463 | * Returns a pointer to the backlight device corresponding to the given DT | |
464 | * node or NULL if no such backlight device exists or if the device hasn't | |
465 | * been probed yet. | |
466 | * | |
467 | * This function obtains a reference on the backlight device and it is the | |
468 | * caller's responsibility to drop the reference by calling put_device() on | |
469 | * the backlight device's .dev field. | |
470 | */ | |
471 | struct backlight_device *of_find_backlight_by_node(struct device_node *node) | |
472 | { | |
473 | struct device *dev; | |
474 | ||
475 | dev = class_find_device(backlight_class, NULL, node, of_parent_match); | |
476 | ||
477 | return dev ? to_backlight_device(dev) : NULL; | |
478 | } | |
479 | EXPORT_SYMBOL(of_find_backlight_by_node); | |
480 | #endif | |
481 | ||
1da177e4 LT |
482 | static void __exit backlight_class_exit(void) |
483 | { | |
655bfd7a | 484 | class_destroy(backlight_class); |
1da177e4 LT |
485 | } |
486 | ||
487 | static int __init backlight_class_init(void) | |
488 | { | |
655bfd7a RP |
489 | backlight_class = class_create(THIS_MODULE, "backlight"); |
490 | if (IS_ERR(backlight_class)) { | |
35f96162 JH |
491 | pr_warn("Unable to create backlight class; errno = %ld\n", |
492 | PTR_ERR(backlight_class)); | |
655bfd7a RP |
493 | return PTR_ERR(backlight_class); |
494 | } | |
495 | ||
496 | backlight_class->dev_attrs = bl_device_attributes; | |
3601792e | 497 | backlight_class->pm = &backlight_class_dev_pm_ops; |
655bfd7a | 498 | return 0; |
1da177e4 LT |
499 | } |
500 | ||
501 | /* | |
502 | * if this is compiled into the kernel, we need to ensure that the | |
503 | * class is registered before users of the class try to register lcd's | |
504 | */ | |
505 | postcore_initcall(backlight_class_init); | |
506 | module_exit(backlight_class_exit); | |
507 | ||
508 | MODULE_LICENSE("GPL"); | |
509 | MODULE_AUTHOR("Jamey Hicks <jamey.hicks@hp.com>, Andrew Zabolotny <zap@homelink.ru>"); | |
510 | MODULE_DESCRIPTION("Backlight Lowlevel Control Abstraction"); |