xref: /linux/drivers/acpi/acpi_video.c (revision 110e6f26af80dfd90b6e5c645b1aed7228aa580d)
1 /*
2  *  video.c - ACPI Video Driver
3  *
4  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
5  *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
6  *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
7  *
8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
9  *
10  *  This program is free software; you can redistribute it and/or modify
11  *  it under the terms of the GNU General Public License as published by
12  *  the Free Software Foundation; either version 2 of the License, or (at
13  *  your option) any later version.
14  *
15  *  This program is distributed in the hope that it will be useful, but
16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18  *  General Public License for more details.
19  *
20  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/types.h>
27 #include <linux/list.h>
28 #include <linux/mutex.h>
29 #include <linux/input.h>
30 #include <linux/backlight.h>
31 #include <linux/thermal.h>
32 #include <linux/sort.h>
33 #include <linux/pci.h>
34 #include <linux/pci_ids.h>
35 #include <linux/slab.h>
36 #include <linux/dmi.h>
37 #include <linux/suspend.h>
38 #include <linux/acpi.h>
39 #include <acpi/video.h>
40 #include <asm/uaccess.h>
41 
42 #define PREFIX "ACPI: "
43 
44 #define ACPI_VIDEO_BUS_NAME		"Video Bus"
45 #define ACPI_VIDEO_DEVICE_NAME		"Video Device"
46 #define ACPI_VIDEO_NOTIFY_SWITCH	0x80
47 #define ACPI_VIDEO_NOTIFY_PROBE		0x81
48 #define ACPI_VIDEO_NOTIFY_CYCLE		0x82
49 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT	0x83
50 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT	0x84
51 
52 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS	0x85
53 #define	ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS	0x86
54 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS	0x87
55 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS	0x88
56 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF		0x89
57 
58 #define MAX_NAME_LEN	20
59 
60 #define _COMPONENT		ACPI_VIDEO_COMPONENT
61 ACPI_MODULE_NAME("video");
62 
63 MODULE_AUTHOR("Bruno Ducrot");
64 MODULE_DESCRIPTION("ACPI Video Driver");
65 MODULE_LICENSE("GPL");
66 
67 static bool brightness_switch_enabled = 1;
68 module_param(brightness_switch_enabled, bool, 0644);
69 
70 /*
71  * By default, we don't allow duplicate ACPI video bus devices
72  * under the same VGA controller
73  */
74 static bool allow_duplicates;
75 module_param(allow_duplicates, bool, 0644);
76 
77 static int disable_backlight_sysfs_if = -1;
78 module_param(disable_backlight_sysfs_if, int, 0444);
79 
80 #define REPORT_OUTPUT_KEY_EVENTS		0x01
81 #define REPORT_BRIGHTNESS_KEY_EVENTS		0x02
82 static int report_key_events = -1;
83 module_param(report_key_events, int, 0644);
84 MODULE_PARM_DESC(report_key_events,
85 	"0: none, 1: output changes, 2: brightness changes, 3: all");
86 
87 static bool device_id_scheme = false;
88 module_param(device_id_scheme, bool, 0444);
89 
90 static bool only_lcd = false;
91 module_param(only_lcd, bool, 0444);
92 
93 static int register_count;
94 static DEFINE_MUTEX(register_count_mutex);
95 static DEFINE_MUTEX(video_list_lock);
96 static LIST_HEAD(video_bus_head);
97 static int acpi_video_bus_add(struct acpi_device *device);
98 static int acpi_video_bus_remove(struct acpi_device *device);
99 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
100 void acpi_video_detect_exit(void);
101 
102 static const struct acpi_device_id video_device_ids[] = {
103 	{ACPI_VIDEO_HID, 0},
104 	{"", 0},
105 };
106 MODULE_DEVICE_TABLE(acpi, video_device_ids);
107 
108 static struct acpi_driver acpi_video_bus = {
109 	.name = "video",
110 	.class = ACPI_VIDEO_CLASS,
111 	.ids = video_device_ids,
112 	.ops = {
113 		.add = acpi_video_bus_add,
114 		.remove = acpi_video_bus_remove,
115 		.notify = acpi_video_bus_notify,
116 		},
117 };
118 
119 struct acpi_video_bus_flags {
120 	u8 multihead:1;		/* can switch video heads */
121 	u8 rom:1;		/* can retrieve a video rom */
122 	u8 post:1;		/* can configure the head to */
123 	u8 reserved:5;
124 };
125 
126 struct acpi_video_bus_cap {
127 	u8 _DOS:1;		/* Enable/Disable output switching */
128 	u8 _DOD:1;		/* Enumerate all devices attached to display adapter */
129 	u8 _ROM:1;		/* Get ROM Data */
130 	u8 _GPD:1;		/* Get POST Device */
131 	u8 _SPD:1;		/* Set POST Device */
132 	u8 _VPO:1;		/* Video POST Options */
133 	u8 reserved:2;
134 };
135 
136 struct acpi_video_device_attrib {
137 	u32 display_index:4;	/* A zero-based instance of the Display */
138 	u32 display_port_attachment:4;	/* This field differentiates the display type */
139 	u32 display_type:4;	/* Describe the specific type in use */
140 	u32 vendor_specific:4;	/* Chipset Vendor Specific */
141 	u32 bios_can_detect:1;	/* BIOS can detect the device */
142 	u32 depend_on_vga:1;	/* Non-VGA output device whose power is related to
143 				   the VGA device. */
144 	u32 pipe_id:3;		/* For VGA multiple-head devices. */
145 	u32 reserved:10;	/* Must be 0 */
146 	u32 device_id_scheme:1;	/* Device ID Scheme */
147 };
148 
149 struct acpi_video_enumerated_device {
150 	union {
151 		u32 int_val;
152 		struct acpi_video_device_attrib attrib;
153 	} value;
154 	struct acpi_video_device *bind_info;
155 };
156 
157 struct acpi_video_bus {
158 	struct acpi_device *device;
159 	bool backlight_registered;
160 	u8 dos_setting;
161 	struct acpi_video_enumerated_device *attached_array;
162 	u8 attached_count;
163 	u8 child_count;
164 	struct acpi_video_bus_cap cap;
165 	struct acpi_video_bus_flags flags;
166 	struct list_head video_device_list;
167 	struct mutex device_list_lock;	/* protects video_device_list */
168 	struct list_head entry;
169 	struct input_dev *input;
170 	char phys[32];	/* for input device */
171 	struct notifier_block pm_nb;
172 };
173 
174 struct acpi_video_device_flags {
175 	u8 crt:1;
176 	u8 lcd:1;
177 	u8 tvout:1;
178 	u8 dvi:1;
179 	u8 bios:1;
180 	u8 unknown:1;
181 	u8 notify:1;
182 	u8 reserved:1;
183 };
184 
185 struct acpi_video_device_cap {
186 	u8 _ADR:1;		/* Return the unique ID */
187 	u8 _BCL:1;		/* Query list of brightness control levels supported */
188 	u8 _BCM:1;		/* Set the brightness level */
189 	u8 _BQC:1;		/* Get current brightness level */
190 	u8 _BCQ:1;		/* Some buggy BIOS uses _BCQ instead of _BQC */
191 	u8 _DDC:1;		/* Return the EDID for this device */
192 };
193 
194 struct acpi_video_brightness_flags {
195 	u8 _BCL_no_ac_battery_levels:1;	/* no AC/Battery levels in _BCL */
196 	u8 _BCL_reversed:1;		/* _BCL package is in a reversed order */
197 	u8 _BQC_use_index:1;		/* _BQC returns an index value */
198 };
199 
200 struct acpi_video_device_brightness {
201 	int curr;
202 	int count;
203 	int *levels;
204 	struct acpi_video_brightness_flags flags;
205 };
206 
207 struct acpi_video_device {
208 	unsigned long device_id;
209 	struct acpi_video_device_flags flags;
210 	struct acpi_video_device_cap cap;
211 	struct list_head entry;
212 	struct delayed_work switch_brightness_work;
213 	int switch_brightness_event;
214 	struct acpi_video_bus *video;
215 	struct acpi_device *dev;
216 	struct acpi_video_device_brightness *brightness;
217 	struct backlight_device *backlight;
218 	struct thermal_cooling_device *cooling_dev;
219 };
220 
221 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
222 static void acpi_video_device_rebind(struct acpi_video_bus *video);
223 static void acpi_video_device_bind(struct acpi_video_bus *video,
224 				   struct acpi_video_device *device);
225 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
226 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
227 			int level);
228 static int acpi_video_device_lcd_get_level_current(
229 			struct acpi_video_device *device,
230 			unsigned long long *level, bool raw);
231 static int acpi_video_get_next_level(struct acpi_video_device *device,
232 				     u32 level_current, u32 event);
233 static void acpi_video_switch_brightness(struct work_struct *work);
234 
235 /* backlight device sysfs support */
236 static int acpi_video_get_brightness(struct backlight_device *bd)
237 {
238 	unsigned long long cur_level;
239 	int i;
240 	struct acpi_video_device *vd = bl_get_data(bd);
241 
242 	if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
243 		return -EINVAL;
244 	for (i = 2; i < vd->brightness->count; i++) {
245 		if (vd->brightness->levels[i] == cur_level)
246 			/*
247 			 * The first two entries are special - see page 575
248 			 * of the ACPI spec 3.0
249 			 */
250 			return i - 2;
251 	}
252 	return 0;
253 }
254 
255 static int acpi_video_set_brightness(struct backlight_device *bd)
256 {
257 	int request_level = bd->props.brightness + 2;
258 	struct acpi_video_device *vd = bl_get_data(bd);
259 
260 	cancel_delayed_work(&vd->switch_brightness_work);
261 	return acpi_video_device_lcd_set_level(vd,
262 				vd->brightness->levels[request_level]);
263 }
264 
265 static const struct backlight_ops acpi_backlight_ops = {
266 	.get_brightness = acpi_video_get_brightness,
267 	.update_status  = acpi_video_set_brightness,
268 };
269 
270 /* thermal cooling device callbacks */
271 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
272 			       long *state)
273 {
274 	struct acpi_device *device = cooling_dev->devdata;
275 	struct acpi_video_device *video = acpi_driver_data(device);
276 
277 	*state = video->brightness->count - 3;
278 	return 0;
279 }
280 
281 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
282 			       long *state)
283 {
284 	struct acpi_device *device = cooling_dev->devdata;
285 	struct acpi_video_device *video = acpi_driver_data(device);
286 	unsigned long long level;
287 	int offset;
288 
289 	if (acpi_video_device_lcd_get_level_current(video, &level, false))
290 		return -EINVAL;
291 	for (offset = 2; offset < video->brightness->count; offset++)
292 		if (level == video->brightness->levels[offset]) {
293 			*state = video->brightness->count - offset - 1;
294 			return 0;
295 		}
296 
297 	return -EINVAL;
298 }
299 
300 static int
301 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
302 {
303 	struct acpi_device *device = cooling_dev->devdata;
304 	struct acpi_video_device *video = acpi_driver_data(device);
305 	int level;
306 
307 	if (state >= video->brightness->count - 2)
308 		return -EINVAL;
309 
310 	state = video->brightness->count - state;
311 	level = video->brightness->levels[state - 1];
312 	return acpi_video_device_lcd_set_level(video, level);
313 }
314 
315 static const struct thermal_cooling_device_ops video_cooling_ops = {
316 	.get_max_state = video_get_max_state,
317 	.get_cur_state = video_get_cur_state,
318 	.set_cur_state = video_set_cur_state,
319 };
320 
321 /*
322  * --------------------------------------------------------------------------
323  *                             Video Management
324  * --------------------------------------------------------------------------
325  */
326 
327 static int
328 acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
329 				   union acpi_object **levels)
330 {
331 	int status;
332 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
333 	union acpi_object *obj;
334 
335 
336 	*levels = NULL;
337 
338 	status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
339 	if (!ACPI_SUCCESS(status))
340 		return status;
341 	obj = (union acpi_object *)buffer.pointer;
342 	if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
343 		printk(KERN_ERR PREFIX "Invalid _BCL data\n");
344 		status = -EFAULT;
345 		goto err;
346 	}
347 
348 	*levels = obj;
349 
350 	return 0;
351 
352 err:
353 	kfree(buffer.pointer);
354 
355 	return status;
356 }
357 
358 static int
359 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
360 {
361 	int status;
362 	int state;
363 
364 	status = acpi_execute_simple_method(device->dev->handle,
365 					    "_BCM", level);
366 	if (ACPI_FAILURE(status)) {
367 		ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
368 		return -EIO;
369 	}
370 
371 	device->brightness->curr = level;
372 	for (state = 2; state < device->brightness->count; state++)
373 		if (level == device->brightness->levels[state]) {
374 			if (device->backlight)
375 				device->backlight->props.brightness = state - 2;
376 			return 0;
377 		}
378 
379 	ACPI_ERROR((AE_INFO, "Current brightness invalid"));
380 	return -EINVAL;
381 }
382 
383 /*
384  * For some buggy _BQC methods, we need to add a constant value to
385  * the _BQC return value to get the actual current brightness level
386  */
387 
388 static int bqc_offset_aml_bug_workaround;
389 static int video_set_bqc_offset(const struct dmi_system_id *d)
390 {
391 	bqc_offset_aml_bug_workaround = 9;
392 	return 0;
393 }
394 
395 static int video_disable_backlight_sysfs_if(
396 	const struct dmi_system_id *d)
397 {
398 	if (disable_backlight_sysfs_if == -1)
399 		disable_backlight_sysfs_if = 1;
400 	return 0;
401 }
402 
403 static int video_set_device_id_scheme(const struct dmi_system_id *d)
404 {
405 	device_id_scheme = true;
406 	return 0;
407 }
408 
409 static int video_enable_only_lcd(const struct dmi_system_id *d)
410 {
411 	only_lcd = true;
412 	return 0;
413 }
414 
415 static int video_set_report_key_events(const struct dmi_system_id *id)
416 {
417 	if (report_key_events == -1)
418 		report_key_events = (uintptr_t)id->driver_data;
419 	return 0;
420 }
421 
422 static struct dmi_system_id video_dmi_table[] = {
423 	/*
424 	 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
425 	 */
426 	{
427 	 .callback = video_set_bqc_offset,
428 	 .ident = "Acer Aspire 5720",
429 	 .matches = {
430 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
431 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
432 		},
433 	},
434 	{
435 	 .callback = video_set_bqc_offset,
436 	 .ident = "Acer Aspire 5710Z",
437 	 .matches = {
438 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
439 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
440 		},
441 	},
442 	{
443 	 .callback = video_set_bqc_offset,
444 	 .ident = "eMachines E510",
445 	 .matches = {
446 		DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
447 		DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
448 		},
449 	},
450 	{
451 	 .callback = video_set_bqc_offset,
452 	 .ident = "Acer Aspire 5315",
453 	 .matches = {
454 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
455 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
456 		},
457 	},
458 	{
459 	 .callback = video_set_bqc_offset,
460 	 .ident = "Acer Aspire 7720",
461 	 .matches = {
462 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
463 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
464 		},
465 	},
466 
467 	/*
468 	 * Some machines have a broken acpi-video interface for brightness
469 	 * control, but still need an acpi_video_device_lcd_set_level() call
470 	 * on resume to turn the backlight power on.  We Enable backlight
471 	 * control on these systems, but do not register a backlight sysfs
472 	 * as brightness control does not work.
473 	 */
474 	{
475 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
476 	 .callback = video_disable_backlight_sysfs_if,
477 	 .ident = "Toshiba Portege R700",
478 	 .matches = {
479 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
480 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
481 		},
482 	},
483 	{
484 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
485 	 .callback = video_disable_backlight_sysfs_if,
486 	 .ident = "Toshiba Portege R830",
487 	 .matches = {
488 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
489 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
490 		},
491 	},
492 	{
493 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
494 	 .callback = video_disable_backlight_sysfs_if,
495 	 .ident = "Toshiba Satellite R830",
496 	 .matches = {
497 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
498 		DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
499 		},
500 	},
501 	/*
502 	 * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
503 	 * but the IDs actually follow the Device ID Scheme.
504 	 */
505 	{
506 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
507 	 .callback = video_set_device_id_scheme,
508 	 .ident = "ESPRIMO Mobile M9410",
509 	 .matches = {
510 		DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
511 		DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
512 		},
513 	},
514 	/*
515 	 * Some machines have multiple video output devices, but only the one
516 	 * that is the type of LCD can do the backlight control so we should not
517 	 * register backlight interface for other video output devices.
518 	 */
519 	{
520 	 /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
521 	 .callback = video_enable_only_lcd,
522 	 .ident = "ESPRIMO Mobile M9410",
523 	 .matches = {
524 		DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
525 		DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
526 		},
527 	},
528 	/*
529 	 * Some machines report wrong key events on the acpi-bus, suppress
530 	 * key event reporting on these.  Note this is only intended to work
531 	 * around events which are plain wrong. In some cases we get double
532 	 * events, in this case acpi-video is considered the canonical source
533 	 * and the events from the other source should be filtered. E.g.
534 	 * by calling acpi_video_handles_brightness_key_presses() from the
535 	 * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
536 	 */
537 	{
538 	 .callback = video_set_report_key_events,
539 	 .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
540 	 .ident = "Dell Vostro V131",
541 	 .matches = {
542 		DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
543 		DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
544 		},
545 	},
546 	{}
547 };
548 
549 static unsigned long long
550 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
551 			      unsigned long long bqc_value)
552 {
553 	unsigned long long level;
554 
555 	if (device->brightness->flags._BQC_use_index) {
556 		/*
557 		 * _BQC returns an index that doesn't account for
558 		 * the first 2 items with special meaning, so we need
559 		 * to compensate for that by offsetting ourselves
560 		 */
561 		if (device->brightness->flags._BCL_reversed)
562 			bqc_value = device->brightness->count - 3 - bqc_value;
563 
564 		level = device->brightness->levels[bqc_value + 2];
565 	} else {
566 		level = bqc_value;
567 	}
568 
569 	level += bqc_offset_aml_bug_workaround;
570 
571 	return level;
572 }
573 
574 static int
575 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
576 					unsigned long long *level, bool raw)
577 {
578 	acpi_status status = AE_OK;
579 	int i;
580 
581 	if (device->cap._BQC || device->cap._BCQ) {
582 		char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
583 
584 		status = acpi_evaluate_integer(device->dev->handle, buf,
585 						NULL, level);
586 		if (ACPI_SUCCESS(status)) {
587 			if (raw) {
588 				/*
589 				 * Caller has indicated he wants the raw
590 				 * value returned by _BQC, so don't furtherly
591 				 * mess with the value.
592 				 */
593 				return 0;
594 			}
595 
596 			*level = acpi_video_bqc_value_to_level(device, *level);
597 
598 			for (i = 2; i < device->brightness->count; i++)
599 				if (device->brightness->levels[i] == *level) {
600 					device->brightness->curr = *level;
601 					return 0;
602 				}
603 			/*
604 			 * BQC returned an invalid level.
605 			 * Stop using it.
606 			 */
607 			ACPI_WARNING((AE_INFO,
608 				      "%s returned an invalid level",
609 				      buf));
610 			device->cap._BQC = device->cap._BCQ = 0;
611 		} else {
612 			/*
613 			 * Fixme:
614 			 * should we return an error or ignore this failure?
615 			 * dev->brightness->curr is a cached value which stores
616 			 * the correct current backlight level in most cases.
617 			 * ACPI video backlight still works w/ buggy _BQC.
618 			 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
619 			 */
620 			ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
621 			device->cap._BQC = device->cap._BCQ = 0;
622 		}
623 	}
624 
625 	*level = device->brightness->curr;
626 	return 0;
627 }
628 
629 static int
630 acpi_video_device_EDID(struct acpi_video_device *device,
631 		       union acpi_object **edid, ssize_t length)
632 {
633 	int status;
634 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
635 	union acpi_object *obj;
636 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
637 	struct acpi_object_list args = { 1, &arg0 };
638 
639 
640 	*edid = NULL;
641 
642 	if (!device)
643 		return -ENODEV;
644 	if (length == 128)
645 		arg0.integer.value = 1;
646 	else if (length == 256)
647 		arg0.integer.value = 2;
648 	else
649 		return -EINVAL;
650 
651 	status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
652 	if (ACPI_FAILURE(status))
653 		return -ENODEV;
654 
655 	obj = buffer.pointer;
656 
657 	if (obj && obj->type == ACPI_TYPE_BUFFER)
658 		*edid = obj;
659 	else {
660 		printk(KERN_ERR PREFIX "Invalid _DDC data\n");
661 		status = -EFAULT;
662 		kfree(obj);
663 	}
664 
665 	return status;
666 }
667 
668 /* bus */
669 
670 /*
671  *  Arg:
672  *	video		: video bus device pointer
673  *	bios_flag	:
674  *		0.	The system BIOS should NOT automatically switch(toggle)
675  *			the active display output.
676  *		1.	The system BIOS should automatically switch (toggle) the
677  *			active display output. No switch event.
678  *		2.	The _DGS value should be locked.
679  *		3.	The system BIOS should not automatically switch (toggle) the
680  *			active display output, but instead generate the display switch
681  *			event notify code.
682  *	lcd_flag	:
683  *		0.	The system BIOS should automatically control the brightness level
684  *			of the LCD when the power changes from AC to DC
685  *		1.	The system BIOS should NOT automatically control the brightness
686  *			level of the LCD when the power changes from AC to DC.
687  *  Return Value:
688  *		-EINVAL	wrong arg.
689  */
690 
691 static int
692 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
693 {
694 	acpi_status status;
695 
696 	if (!video->cap._DOS)
697 		return 0;
698 
699 	if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
700 		return -EINVAL;
701 	video->dos_setting = (lcd_flag << 2) | bios_flag;
702 	status = acpi_execute_simple_method(video->device->handle, "_DOS",
703 					    (lcd_flag << 2) | bios_flag);
704 	if (ACPI_FAILURE(status))
705 		return -EIO;
706 
707 	return 0;
708 }
709 
710 /*
711  * Simple comparison function used to sort backlight levels.
712  */
713 
714 static int
715 acpi_video_cmp_level(const void *a, const void *b)
716 {
717 	return *(int *)a - *(int *)b;
718 }
719 
720 /*
721  * Decides if _BQC/_BCQ for this system is usable
722  *
723  * We do this by changing the level first and then read out the current
724  * brightness level, if the value does not match, find out if it is using
725  * index. If not, clear the _BQC/_BCQ capability.
726  */
727 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
728 				int max_level, int current_level)
729 {
730 	struct acpi_video_device_brightness *br = device->brightness;
731 	int result;
732 	unsigned long long level;
733 	int test_level;
734 
735 	/* don't mess with existing known broken systems */
736 	if (bqc_offset_aml_bug_workaround)
737 		return 0;
738 
739 	/*
740 	 * Some systems always report current brightness level as maximum
741 	 * through _BQC, we need to test another value for them.
742 	 */
743 	test_level = current_level == max_level ? br->levels[3] : max_level;
744 
745 	result = acpi_video_device_lcd_set_level(device, test_level);
746 	if (result)
747 		return result;
748 
749 	result = acpi_video_device_lcd_get_level_current(device, &level, true);
750 	if (result)
751 		return result;
752 
753 	if (level != test_level) {
754 		/* buggy _BQC found, need to find out if it uses index */
755 		if (level < br->count) {
756 			if (br->flags._BCL_reversed)
757 				level = br->count - 3 - level;
758 			if (br->levels[level + 2] == test_level)
759 				br->flags._BQC_use_index = 1;
760 		}
761 
762 		if (!br->flags._BQC_use_index)
763 			device->cap._BQC = device->cap._BCQ = 0;
764 	}
765 
766 	return 0;
767 }
768 
769 
770 /*
771  *  Arg:
772  *	device	: video output device (LCD, CRT, ..)
773  *
774  *  Return Value:
775  *	Maximum brightness level
776  *
777  *  Allocate and initialize device->brightness.
778  */
779 
780 static int
781 acpi_video_init_brightness(struct acpi_video_device *device)
782 {
783 	union acpi_object *obj = NULL;
784 	int i, max_level = 0, count = 0, level_ac_battery = 0;
785 	unsigned long long level, level_old;
786 	union acpi_object *o;
787 	struct acpi_video_device_brightness *br = NULL;
788 	int result = -EINVAL;
789 	u32 value;
790 
791 	if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
792 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
793 						"LCD brightness level\n"));
794 		goto out;
795 	}
796 
797 	if (obj->package.count < 2)
798 		goto out;
799 
800 	br = kzalloc(sizeof(*br), GFP_KERNEL);
801 	if (!br) {
802 		printk(KERN_ERR "can't allocate memory\n");
803 		result = -ENOMEM;
804 		goto out;
805 	}
806 
807 	br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
808 				GFP_KERNEL);
809 	if (!br->levels) {
810 		result = -ENOMEM;
811 		goto out_free;
812 	}
813 
814 	for (i = 0; i < obj->package.count; i++) {
815 		o = (union acpi_object *)&obj->package.elements[i];
816 		if (o->type != ACPI_TYPE_INTEGER) {
817 			printk(KERN_ERR PREFIX "Invalid data\n");
818 			continue;
819 		}
820 		value = (u32) o->integer.value;
821 		/* Skip duplicate entries */
822 		if (count > 2 && br->levels[count - 1] == value)
823 			continue;
824 
825 		br->levels[count] = value;
826 
827 		if (br->levels[count] > max_level)
828 			max_level = br->levels[count];
829 		count++;
830 	}
831 
832 	/*
833 	 * some buggy BIOS don't export the levels
834 	 * when machine is on AC/Battery in _BCL package.
835 	 * In this case, the first two elements in _BCL packages
836 	 * are also supported brightness levels that OS should take care of.
837 	 */
838 	for (i = 2; i < count; i++) {
839 		if (br->levels[i] == br->levels[0])
840 			level_ac_battery++;
841 		if (br->levels[i] == br->levels[1])
842 			level_ac_battery++;
843 	}
844 
845 	if (level_ac_battery < 2) {
846 		level_ac_battery = 2 - level_ac_battery;
847 		br->flags._BCL_no_ac_battery_levels = 1;
848 		for (i = (count - 1 + level_ac_battery); i >= 2; i--)
849 			br->levels[i] = br->levels[i - level_ac_battery];
850 		count += level_ac_battery;
851 	} else if (level_ac_battery > 2)
852 		ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
853 
854 	/* Check if the _BCL package is in a reversed order */
855 	if (max_level == br->levels[2]) {
856 		br->flags._BCL_reversed = 1;
857 		sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
858 			acpi_video_cmp_level, NULL);
859 	} else if (max_level != br->levels[count - 1])
860 		ACPI_ERROR((AE_INFO,
861 			    "Found unordered _BCL package"));
862 
863 	br->count = count;
864 	device->brightness = br;
865 
866 	/* _BQC uses INDEX while _BCL uses VALUE in some laptops */
867 	br->curr = level = max_level;
868 
869 	if (!device->cap._BQC)
870 		goto set_level;
871 
872 	result = acpi_video_device_lcd_get_level_current(device,
873 							 &level_old, true);
874 	if (result)
875 		goto out_free_levels;
876 
877 	result = acpi_video_bqc_quirk(device, max_level, level_old);
878 	if (result)
879 		goto out_free_levels;
880 	/*
881 	 * cap._BQC may get cleared due to _BQC is found to be broken
882 	 * in acpi_video_bqc_quirk, so check again here.
883 	 */
884 	if (!device->cap._BQC)
885 		goto set_level;
886 
887 	level = acpi_video_bqc_value_to_level(device, level_old);
888 	/*
889 	 * On some buggy laptops, _BQC returns an uninitialized
890 	 * value when invoked for the first time, i.e.
891 	 * level_old is invalid (no matter whether it's a level
892 	 * or an index). Set the backlight to max_level in this case.
893 	 */
894 	for (i = 2; i < br->count; i++)
895 		if (level == br->levels[i])
896 			break;
897 	if (i == br->count || !level)
898 		level = max_level;
899 
900 set_level:
901 	result = acpi_video_device_lcd_set_level(device, level);
902 	if (result)
903 		goto out_free_levels;
904 
905 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
906 			  "found %d brightness levels\n", count - 2));
907 	kfree(obj);
908 	return result;
909 
910 out_free_levels:
911 	kfree(br->levels);
912 out_free:
913 	kfree(br);
914 out:
915 	device->brightness = NULL;
916 	kfree(obj);
917 	return result;
918 }
919 
920 /*
921  *  Arg:
922  *	device	: video output device (LCD, CRT, ..)
923  *
924  *  Return Value:
925  *	None
926  *
927  *  Find out all required AML methods defined under the output
928  *  device.
929  */
930 
931 static void acpi_video_device_find_cap(struct acpi_video_device *device)
932 {
933 	if (acpi_has_method(device->dev->handle, "_ADR"))
934 		device->cap._ADR = 1;
935 	if (acpi_has_method(device->dev->handle, "_BCL"))
936 		device->cap._BCL = 1;
937 	if (acpi_has_method(device->dev->handle, "_BCM"))
938 		device->cap._BCM = 1;
939 	if (acpi_has_method(device->dev->handle, "_BQC")) {
940 		device->cap._BQC = 1;
941 	} else if (acpi_has_method(device->dev->handle, "_BCQ")) {
942 		printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
943 		device->cap._BCQ = 1;
944 	}
945 
946 	if (acpi_has_method(device->dev->handle, "_DDC"))
947 		device->cap._DDC = 1;
948 }
949 
950 /*
951  *  Arg:
952  *	device	: video output device (VGA)
953  *
954  *  Return Value:
955  *	None
956  *
957  *  Find out all required AML methods defined under the video bus device.
958  */
959 
960 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
961 {
962 	if (acpi_has_method(video->device->handle, "_DOS"))
963 		video->cap._DOS = 1;
964 	if (acpi_has_method(video->device->handle, "_DOD"))
965 		video->cap._DOD = 1;
966 	if (acpi_has_method(video->device->handle, "_ROM"))
967 		video->cap._ROM = 1;
968 	if (acpi_has_method(video->device->handle, "_GPD"))
969 		video->cap._GPD = 1;
970 	if (acpi_has_method(video->device->handle, "_SPD"))
971 		video->cap._SPD = 1;
972 	if (acpi_has_method(video->device->handle, "_VPO"))
973 		video->cap._VPO = 1;
974 }
975 
976 /*
977  * Check whether the video bus device has required AML method to
978  * support the desired features
979  */
980 
981 static int acpi_video_bus_check(struct acpi_video_bus *video)
982 {
983 	acpi_status status = -ENOENT;
984 	struct pci_dev *dev;
985 
986 	if (!video)
987 		return -EINVAL;
988 
989 	dev = acpi_get_pci_dev(video->device->handle);
990 	if (!dev)
991 		return -ENODEV;
992 	pci_dev_put(dev);
993 
994 	/*
995 	 * Since there is no HID, CID and so on for VGA driver, we have
996 	 * to check well known required nodes.
997 	 */
998 
999 	/* Does this device support video switching? */
1000 	if (video->cap._DOS || video->cap._DOD) {
1001 		if (!video->cap._DOS) {
1002 			printk(KERN_WARNING FW_BUG
1003 				"ACPI(%s) defines _DOD but not _DOS\n",
1004 				acpi_device_bid(video->device));
1005 		}
1006 		video->flags.multihead = 1;
1007 		status = 0;
1008 	}
1009 
1010 	/* Does this device support retrieving a video ROM? */
1011 	if (video->cap._ROM) {
1012 		video->flags.rom = 1;
1013 		status = 0;
1014 	}
1015 
1016 	/* Does this device support configuring which video device to POST? */
1017 	if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1018 		video->flags.post = 1;
1019 		status = 0;
1020 	}
1021 
1022 	return status;
1023 }
1024 
1025 /*
1026  * --------------------------------------------------------------------------
1027  *                               Driver Interface
1028  * --------------------------------------------------------------------------
1029  */
1030 
1031 /* device interface */
1032 static struct acpi_video_device_attrib *
1033 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1034 {
1035 	struct acpi_video_enumerated_device *ids;
1036 	int i;
1037 
1038 	for (i = 0; i < video->attached_count; i++) {
1039 		ids = &video->attached_array[i];
1040 		if ((ids->value.int_val & 0xffff) == device_id)
1041 			return &ids->value.attrib;
1042 	}
1043 
1044 	return NULL;
1045 }
1046 
1047 static int
1048 acpi_video_get_device_type(struct acpi_video_bus *video,
1049 			   unsigned long device_id)
1050 {
1051 	struct acpi_video_enumerated_device *ids;
1052 	int i;
1053 
1054 	for (i = 0; i < video->attached_count; i++) {
1055 		ids = &video->attached_array[i];
1056 		if ((ids->value.int_val & 0xffff) == device_id)
1057 			return ids->value.int_val;
1058 	}
1059 
1060 	return 0;
1061 }
1062 
1063 static int
1064 acpi_video_bus_get_one_device(struct acpi_device *device,
1065 			      struct acpi_video_bus *video)
1066 {
1067 	unsigned long long device_id;
1068 	int status, device_type;
1069 	struct acpi_video_device *data;
1070 	struct acpi_video_device_attrib *attribute;
1071 
1072 	status =
1073 	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1074 	/* Some device omits _ADR, we skip them instead of fail */
1075 	if (ACPI_FAILURE(status))
1076 		return 0;
1077 
1078 	data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1079 	if (!data)
1080 		return -ENOMEM;
1081 
1082 	strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1083 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1084 	device->driver_data = data;
1085 
1086 	data->device_id = device_id;
1087 	data->video = video;
1088 	data->dev = device;
1089 	INIT_DELAYED_WORK(&data->switch_brightness_work,
1090 			  acpi_video_switch_brightness);
1091 
1092 	attribute = acpi_video_get_device_attr(video, device_id);
1093 
1094 	if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1095 		switch (attribute->display_type) {
1096 		case ACPI_VIDEO_DISPLAY_CRT:
1097 			data->flags.crt = 1;
1098 			break;
1099 		case ACPI_VIDEO_DISPLAY_TV:
1100 			data->flags.tvout = 1;
1101 			break;
1102 		case ACPI_VIDEO_DISPLAY_DVI:
1103 			data->flags.dvi = 1;
1104 			break;
1105 		case ACPI_VIDEO_DISPLAY_LCD:
1106 			data->flags.lcd = 1;
1107 			break;
1108 		default:
1109 			data->flags.unknown = 1;
1110 			break;
1111 		}
1112 		if (attribute->bios_can_detect)
1113 			data->flags.bios = 1;
1114 	} else {
1115 		/* Check for legacy IDs */
1116 		device_type = acpi_video_get_device_type(video, device_id);
1117 		/* Ignore bits 16 and 18-20 */
1118 		switch (device_type & 0xffe2ffff) {
1119 		case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1120 			data->flags.crt = 1;
1121 			break;
1122 		case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1123 			data->flags.lcd = 1;
1124 			break;
1125 		case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1126 			data->flags.tvout = 1;
1127 			break;
1128 		default:
1129 			data->flags.unknown = 1;
1130 		}
1131 	}
1132 
1133 	acpi_video_device_bind(video, data);
1134 	acpi_video_device_find_cap(data);
1135 
1136 	mutex_lock(&video->device_list_lock);
1137 	list_add_tail(&data->entry, &video->video_device_list);
1138 	mutex_unlock(&video->device_list_lock);
1139 
1140 	return status;
1141 }
1142 
1143 /*
1144  *  Arg:
1145  *	video	: video bus device
1146  *
1147  *  Return:
1148  *	none
1149  *
1150  *  Enumerate the video device list of the video bus,
1151  *  bind the ids with the corresponding video devices
1152  *  under the video bus.
1153  */
1154 
1155 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1156 {
1157 	struct acpi_video_device *dev;
1158 
1159 	mutex_lock(&video->device_list_lock);
1160 
1161 	list_for_each_entry(dev, &video->video_device_list, entry)
1162 		acpi_video_device_bind(video, dev);
1163 
1164 	mutex_unlock(&video->device_list_lock);
1165 }
1166 
1167 /*
1168  *  Arg:
1169  *	video	: video bus device
1170  *	device	: video output device under the video
1171  *		bus
1172  *
1173  *  Return:
1174  *	none
1175  *
1176  *  Bind the ids with the corresponding video devices
1177  *  under the video bus.
1178  */
1179 
1180 static void
1181 acpi_video_device_bind(struct acpi_video_bus *video,
1182 		       struct acpi_video_device *device)
1183 {
1184 	struct acpi_video_enumerated_device *ids;
1185 	int i;
1186 
1187 	for (i = 0; i < video->attached_count; i++) {
1188 		ids = &video->attached_array[i];
1189 		if (device->device_id == (ids->value.int_val & 0xffff)) {
1190 			ids->bind_info = device;
1191 			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1192 		}
1193 	}
1194 }
1195 
1196 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1197 {
1198 	struct acpi_video_bus *video = device->video;
1199 	int i;
1200 
1201 	/*
1202 	 * If we have a broken _DOD or we have more than 8 output devices
1203 	 * under the graphics controller node that we can't proper deal with
1204 	 * in the operation region code currently, no need to test.
1205 	 */
1206 	if (!video->attached_count || video->child_count > 8)
1207 		return true;
1208 
1209 	for (i = 0; i < video->attached_count; i++) {
1210 		if ((video->attached_array[i].value.int_val & 0xfff) ==
1211 		    (device->device_id & 0xfff))
1212 			return true;
1213 	}
1214 
1215 	return false;
1216 }
1217 
1218 /*
1219  *  Arg:
1220  *	video	: video bus device
1221  *
1222  *  Return:
1223  *	< 0	: error
1224  *
1225  *  Call _DOD to enumerate all devices attached to display adapter
1226  *
1227  */
1228 
1229 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1230 {
1231 	int status;
1232 	int count;
1233 	int i;
1234 	struct acpi_video_enumerated_device *active_list;
1235 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1236 	union acpi_object *dod = NULL;
1237 	union acpi_object *obj;
1238 
1239 	status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1240 	if (!ACPI_SUCCESS(status)) {
1241 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1242 		return status;
1243 	}
1244 
1245 	dod = buffer.pointer;
1246 	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1247 		ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1248 		status = -EFAULT;
1249 		goto out;
1250 	}
1251 
1252 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1253 			  dod->package.count));
1254 
1255 	active_list = kcalloc(1 + dod->package.count,
1256 			      sizeof(struct acpi_video_enumerated_device),
1257 			      GFP_KERNEL);
1258 	if (!active_list) {
1259 		status = -ENOMEM;
1260 		goto out;
1261 	}
1262 
1263 	count = 0;
1264 	for (i = 0; i < dod->package.count; i++) {
1265 		obj = &dod->package.elements[i];
1266 
1267 		if (obj->type != ACPI_TYPE_INTEGER) {
1268 			printk(KERN_ERR PREFIX
1269 				"Invalid _DOD data in element %d\n", i);
1270 			continue;
1271 		}
1272 
1273 		active_list[count].value.int_val = obj->integer.value;
1274 		active_list[count].bind_info = NULL;
1275 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1276 				  (int)obj->integer.value));
1277 		count++;
1278 	}
1279 
1280 	kfree(video->attached_array);
1281 
1282 	video->attached_array = active_list;
1283 	video->attached_count = count;
1284 
1285 out:
1286 	kfree(buffer.pointer);
1287 	return status;
1288 }
1289 
1290 static int
1291 acpi_video_get_next_level(struct acpi_video_device *device,
1292 			  u32 level_current, u32 event)
1293 {
1294 	int min, max, min_above, max_below, i, l, delta = 255;
1295 	max = max_below = 0;
1296 	min = min_above = 255;
1297 	/* Find closest level to level_current */
1298 	for (i = 2; i < device->brightness->count; i++) {
1299 		l = device->brightness->levels[i];
1300 		if (abs(l - level_current) < abs(delta)) {
1301 			delta = l - level_current;
1302 			if (!delta)
1303 				break;
1304 		}
1305 	}
1306 	/* Ajust level_current to closest available level */
1307 	level_current += delta;
1308 	for (i = 2; i < device->brightness->count; i++) {
1309 		l = device->brightness->levels[i];
1310 		if (l < min)
1311 			min = l;
1312 		if (l > max)
1313 			max = l;
1314 		if (l < min_above && l > level_current)
1315 			min_above = l;
1316 		if (l > max_below && l < level_current)
1317 			max_below = l;
1318 	}
1319 
1320 	switch (event) {
1321 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1322 		return (level_current < max) ? min_above : min;
1323 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1324 		return (level_current < max) ? min_above : max;
1325 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1326 		return (level_current > min) ? max_below : min;
1327 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1328 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1329 		return 0;
1330 	default:
1331 		return level_current;
1332 	}
1333 }
1334 
1335 static void
1336 acpi_video_switch_brightness(struct work_struct *work)
1337 {
1338 	struct acpi_video_device *device = container_of(to_delayed_work(work),
1339 			     struct acpi_video_device, switch_brightness_work);
1340 	unsigned long long level_current, level_next;
1341 	int event = device->switch_brightness_event;
1342 	int result = -EINVAL;
1343 
1344 	/* no warning message if acpi_backlight=vendor or a quirk is used */
1345 	if (!device->backlight)
1346 		return;
1347 
1348 	if (!device->brightness)
1349 		goto out;
1350 
1351 	result = acpi_video_device_lcd_get_level_current(device,
1352 							 &level_current,
1353 							 false);
1354 	if (result)
1355 		goto out;
1356 
1357 	level_next = acpi_video_get_next_level(device, level_current, event);
1358 
1359 	result = acpi_video_device_lcd_set_level(device, level_next);
1360 
1361 	if (!result)
1362 		backlight_force_update(device->backlight,
1363 				       BACKLIGHT_UPDATE_HOTKEY);
1364 
1365 out:
1366 	if (result)
1367 		printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1368 }
1369 
1370 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1371 			void **edid)
1372 {
1373 	struct acpi_video_bus *video;
1374 	struct acpi_video_device *video_device;
1375 	union acpi_object *buffer = NULL;
1376 	acpi_status status;
1377 	int i, length;
1378 
1379 	if (!device || !acpi_driver_data(device))
1380 		return -EINVAL;
1381 
1382 	video = acpi_driver_data(device);
1383 
1384 	for (i = 0; i < video->attached_count; i++) {
1385 		video_device = video->attached_array[i].bind_info;
1386 		length = 256;
1387 
1388 		if (!video_device)
1389 			continue;
1390 
1391 		if (!video_device->cap._DDC)
1392 			continue;
1393 
1394 		if (type) {
1395 			switch (type) {
1396 			case ACPI_VIDEO_DISPLAY_CRT:
1397 				if (!video_device->flags.crt)
1398 					continue;
1399 				break;
1400 			case ACPI_VIDEO_DISPLAY_TV:
1401 				if (!video_device->flags.tvout)
1402 					continue;
1403 				break;
1404 			case ACPI_VIDEO_DISPLAY_DVI:
1405 				if (!video_device->flags.dvi)
1406 					continue;
1407 				break;
1408 			case ACPI_VIDEO_DISPLAY_LCD:
1409 				if (!video_device->flags.lcd)
1410 					continue;
1411 				break;
1412 			}
1413 		} else if (video_device->device_id != device_id) {
1414 			continue;
1415 		}
1416 
1417 		status = acpi_video_device_EDID(video_device, &buffer, length);
1418 
1419 		if (ACPI_FAILURE(status) || !buffer ||
1420 		    buffer->type != ACPI_TYPE_BUFFER) {
1421 			length = 128;
1422 			status = acpi_video_device_EDID(video_device, &buffer,
1423 							length);
1424 			if (ACPI_FAILURE(status) || !buffer ||
1425 			    buffer->type != ACPI_TYPE_BUFFER) {
1426 				continue;
1427 			}
1428 		}
1429 
1430 		*edid = buffer->buffer.pointer;
1431 		return length;
1432 	}
1433 
1434 	return -ENODEV;
1435 }
1436 EXPORT_SYMBOL(acpi_video_get_edid);
1437 
1438 static int
1439 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1440 			   struct acpi_device *device)
1441 {
1442 	int status = 0;
1443 	struct acpi_device *dev;
1444 
1445 	/*
1446 	 * There are systems where video module known to work fine regardless
1447 	 * of broken _DOD and ignoring returned value here doesn't cause
1448 	 * any issues later.
1449 	 */
1450 	acpi_video_device_enumerate(video);
1451 
1452 	list_for_each_entry(dev, &device->children, node) {
1453 
1454 		status = acpi_video_bus_get_one_device(dev, video);
1455 		if (status) {
1456 			dev_err(&dev->dev, "Can't attach device\n");
1457 			break;
1458 		}
1459 		video->child_count++;
1460 	}
1461 	return status;
1462 }
1463 
1464 /* acpi_video interface */
1465 
1466 /*
1467  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1468  * preform any automatic brightness change on receiving a notification.
1469  */
1470 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1471 {
1472 	return acpi_video_bus_DOS(video, 0,
1473 				  acpi_osi_is_win8() ? 1 : 0);
1474 }
1475 
1476 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1477 {
1478 	return acpi_video_bus_DOS(video, 0,
1479 				  acpi_osi_is_win8() ? 0 : 1);
1480 }
1481 
1482 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1483 {
1484 	struct acpi_video_bus *video = acpi_driver_data(device);
1485 	struct input_dev *input;
1486 	int keycode = 0;
1487 
1488 	if (!video || !video->input)
1489 		return;
1490 
1491 	input = video->input;
1492 
1493 	switch (event) {
1494 	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User requested a switch,
1495 					 * most likely via hotkey. */
1496 		keycode = KEY_SWITCHVIDEOMODE;
1497 		break;
1498 
1499 	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plugged in or removed a video
1500 					 * connector. */
1501 		acpi_video_device_enumerate(video);
1502 		acpi_video_device_rebind(video);
1503 		keycode = KEY_SWITCHVIDEOMODE;
1504 		break;
1505 
1506 	case ACPI_VIDEO_NOTIFY_CYCLE:	/* Cycle Display output hotkey pressed. */
1507 		keycode = KEY_SWITCHVIDEOMODE;
1508 		break;
1509 	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:	/* Next Display output hotkey pressed. */
1510 		keycode = KEY_VIDEO_NEXT;
1511 		break;
1512 	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:	/* previous Display output hotkey pressed. */
1513 		keycode = KEY_VIDEO_PREV;
1514 		break;
1515 
1516 	default:
1517 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1518 				  "Unsupported event [0x%x]\n", event));
1519 		break;
1520 	}
1521 
1522 	if (acpi_notifier_call_chain(device, event, 0))
1523 		/* Something vetoed the keypress. */
1524 		keycode = 0;
1525 
1526 	if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1527 		input_report_key(input, keycode, 1);
1528 		input_sync(input);
1529 		input_report_key(input, keycode, 0);
1530 		input_sync(input);
1531 	}
1532 
1533 	return;
1534 }
1535 
1536 static void brightness_switch_event(struct acpi_video_device *video_device,
1537 				    u32 event)
1538 {
1539 	if (!brightness_switch_enabled)
1540 		return;
1541 
1542 	video_device->switch_brightness_event = event;
1543 	schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1544 }
1545 
1546 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1547 {
1548 	struct acpi_video_device *video_device = data;
1549 	struct acpi_device *device = NULL;
1550 	struct acpi_video_bus *bus;
1551 	struct input_dev *input;
1552 	int keycode = 0;
1553 
1554 	if (!video_device)
1555 		return;
1556 
1557 	device = video_device->dev;
1558 	bus = video_device->video;
1559 	input = bus->input;
1560 
1561 	switch (event) {
1562 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:	/* Cycle brightness */
1563 		brightness_switch_event(video_device, event);
1564 		keycode = KEY_BRIGHTNESS_CYCLE;
1565 		break;
1566 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:	/* Increase brightness */
1567 		brightness_switch_event(video_device, event);
1568 		keycode = KEY_BRIGHTNESSUP;
1569 		break;
1570 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:	/* Decrease brightness */
1571 		brightness_switch_event(video_device, event);
1572 		keycode = KEY_BRIGHTNESSDOWN;
1573 		break;
1574 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightness */
1575 		brightness_switch_event(video_device, event);
1576 		keycode = KEY_BRIGHTNESS_ZERO;
1577 		break;
1578 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:	/* display device off */
1579 		brightness_switch_event(video_device, event);
1580 		keycode = KEY_DISPLAY_OFF;
1581 		break;
1582 	default:
1583 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1584 				  "Unsupported event [0x%x]\n", event));
1585 		break;
1586 	}
1587 
1588 	acpi_notifier_call_chain(device, event, 0);
1589 
1590 	if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1591 		input_report_key(input, keycode, 1);
1592 		input_sync(input);
1593 		input_report_key(input, keycode, 0);
1594 		input_sync(input);
1595 	}
1596 
1597 	return;
1598 }
1599 
1600 static int acpi_video_resume(struct notifier_block *nb,
1601 				unsigned long val, void *ign)
1602 {
1603 	struct acpi_video_bus *video;
1604 	struct acpi_video_device *video_device;
1605 	int i;
1606 
1607 	switch (val) {
1608 	case PM_HIBERNATION_PREPARE:
1609 	case PM_SUSPEND_PREPARE:
1610 	case PM_RESTORE_PREPARE:
1611 		return NOTIFY_DONE;
1612 	}
1613 
1614 	video = container_of(nb, struct acpi_video_bus, pm_nb);
1615 
1616 	dev_info(&video->device->dev, "Restoring backlight state\n");
1617 
1618 	for (i = 0; i < video->attached_count; i++) {
1619 		video_device = video->attached_array[i].bind_info;
1620 		if (video_device && video_device->brightness)
1621 			acpi_video_device_lcd_set_level(video_device,
1622 					video_device->brightness->curr);
1623 	}
1624 
1625 	return NOTIFY_OK;
1626 }
1627 
1628 static acpi_status
1629 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1630 			void **return_value)
1631 {
1632 	struct acpi_device *device = context;
1633 	struct acpi_device *sibling;
1634 	int result;
1635 
1636 	if (handle == device->handle)
1637 		return AE_CTRL_TERMINATE;
1638 
1639 	result = acpi_bus_get_device(handle, &sibling);
1640 	if (result)
1641 		return AE_OK;
1642 
1643 	if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1644 			return AE_ALREADY_EXISTS;
1645 
1646 	return AE_OK;
1647 }
1648 
1649 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1650 {
1651 	struct backlight_properties props;
1652 	struct pci_dev *pdev;
1653 	acpi_handle acpi_parent;
1654 	struct device *parent = NULL;
1655 	int result;
1656 	static int count;
1657 	char *name;
1658 
1659 	result = acpi_video_init_brightness(device);
1660 	if (result)
1661 		return;
1662 
1663 	if (disable_backlight_sysfs_if > 0)
1664 		return;
1665 
1666 	name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1667 	if (!name)
1668 		return;
1669 	count++;
1670 
1671 	acpi_get_parent(device->dev->handle, &acpi_parent);
1672 
1673 	pdev = acpi_get_pci_dev(acpi_parent);
1674 	if (pdev) {
1675 		parent = &pdev->dev;
1676 		pci_dev_put(pdev);
1677 	}
1678 
1679 	memset(&props, 0, sizeof(struct backlight_properties));
1680 	props.type = BACKLIGHT_FIRMWARE;
1681 	props.max_brightness = device->brightness->count - 3;
1682 	device->backlight = backlight_device_register(name,
1683 						      parent,
1684 						      device,
1685 						      &acpi_backlight_ops,
1686 						      &props);
1687 	kfree(name);
1688 	if (IS_ERR(device->backlight)) {
1689 		device->backlight = NULL;
1690 		return;
1691 	}
1692 
1693 	/*
1694 	 * Save current brightness level in case we have to restore it
1695 	 * before acpi_video_device_lcd_set_level() is called next time.
1696 	 */
1697 	device->backlight->props.brightness =
1698 			acpi_video_get_brightness(device->backlight);
1699 
1700 	device->cooling_dev = thermal_cooling_device_register("LCD",
1701 				device->dev, &video_cooling_ops);
1702 	if (IS_ERR(device->cooling_dev)) {
1703 		/*
1704 		 * Set cooling_dev to NULL so we don't crash trying to free it.
1705 		 * Also, why the hell we are returning early and not attempt to
1706 		 * register video output if cooling device registration failed?
1707 		 * -- dtor
1708 		 */
1709 		device->cooling_dev = NULL;
1710 		return;
1711 	}
1712 
1713 	dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1714 		 device->cooling_dev->id);
1715 	result = sysfs_create_link(&device->dev->dev.kobj,
1716 			&device->cooling_dev->device.kobj,
1717 			"thermal_cooling");
1718 	if (result)
1719 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1720 	result = sysfs_create_link(&device->cooling_dev->device.kobj,
1721 			&device->dev->dev.kobj, "device");
1722 	if (result)
1723 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1724 }
1725 
1726 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1727 {
1728 	struct acpi_video_device *dev;
1729 	union acpi_object *levels;
1730 
1731 	mutex_lock(&video->device_list_lock);
1732 	list_for_each_entry(dev, &video->video_device_list, entry) {
1733 		if (!acpi_video_device_lcd_query_levels(dev, &levels))
1734 			kfree(levels);
1735 	}
1736 	mutex_unlock(&video->device_list_lock);
1737 }
1738 
1739 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1740 {
1741 	/*
1742 	 * Do not create backlight device for video output
1743 	 * device that is not in the enumerated list.
1744 	 */
1745 	if (!acpi_video_device_in_dod(dev)) {
1746 		dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1747 		return false;
1748 	}
1749 
1750 	if (only_lcd)
1751 		return dev->flags.lcd;
1752 	return true;
1753 }
1754 
1755 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1756 {
1757 	struct acpi_video_device *dev;
1758 
1759 	if (video->backlight_registered)
1760 		return 0;
1761 
1762 	acpi_video_run_bcl_for_osi(video);
1763 
1764 	if (acpi_video_get_backlight_type() != acpi_backlight_video)
1765 		return 0;
1766 
1767 	mutex_lock(&video->device_list_lock);
1768 	list_for_each_entry(dev, &video->video_device_list, entry) {
1769 		if (acpi_video_should_register_backlight(dev))
1770 			acpi_video_dev_register_backlight(dev);
1771 	}
1772 	mutex_unlock(&video->device_list_lock);
1773 
1774 	video->backlight_registered = true;
1775 
1776 	video->pm_nb.notifier_call = acpi_video_resume;
1777 	video->pm_nb.priority = 0;
1778 	return register_pm_notifier(&video->pm_nb);
1779 }
1780 
1781 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1782 {
1783 	if (device->backlight) {
1784 		backlight_device_unregister(device->backlight);
1785 		device->backlight = NULL;
1786 	}
1787 	if (device->brightness) {
1788 		kfree(device->brightness->levels);
1789 		kfree(device->brightness);
1790 		device->brightness = NULL;
1791 	}
1792 	if (device->cooling_dev) {
1793 		sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1794 		sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1795 		thermal_cooling_device_unregister(device->cooling_dev);
1796 		device->cooling_dev = NULL;
1797 	}
1798 }
1799 
1800 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1801 {
1802 	struct acpi_video_device *dev;
1803 	int error;
1804 
1805 	if (!video->backlight_registered)
1806 		return 0;
1807 
1808 	error = unregister_pm_notifier(&video->pm_nb);
1809 
1810 	mutex_lock(&video->device_list_lock);
1811 	list_for_each_entry(dev, &video->video_device_list, entry)
1812 		acpi_video_dev_unregister_backlight(dev);
1813 	mutex_unlock(&video->device_list_lock);
1814 
1815 	video->backlight_registered = false;
1816 
1817 	return error;
1818 }
1819 
1820 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1821 {
1822 	acpi_status status;
1823 	struct acpi_device *adev = device->dev;
1824 
1825 	status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1826 					     acpi_video_device_notify, device);
1827 	if (ACPI_FAILURE(status))
1828 		dev_err(&adev->dev, "Error installing notify handler\n");
1829 	else
1830 		device->flags.notify = 1;
1831 }
1832 
1833 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1834 {
1835 	struct input_dev *input;
1836 	struct acpi_video_device *dev;
1837 	int error;
1838 
1839 	video->input = input = input_allocate_device();
1840 	if (!input) {
1841 		error = -ENOMEM;
1842 		goto out;
1843 	}
1844 
1845 	error = acpi_video_bus_start_devices(video);
1846 	if (error)
1847 		goto err_free_input;
1848 
1849 	snprintf(video->phys, sizeof(video->phys),
1850 			"%s/video/input0", acpi_device_hid(video->device));
1851 
1852 	input->name = acpi_device_name(video->device);
1853 	input->phys = video->phys;
1854 	input->id.bustype = BUS_HOST;
1855 	input->id.product = 0x06;
1856 	input->dev.parent = &video->device->dev;
1857 	input->evbit[0] = BIT(EV_KEY);
1858 	set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1859 	set_bit(KEY_VIDEO_NEXT, input->keybit);
1860 	set_bit(KEY_VIDEO_PREV, input->keybit);
1861 	set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1862 	set_bit(KEY_BRIGHTNESSUP, input->keybit);
1863 	set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1864 	set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1865 	set_bit(KEY_DISPLAY_OFF, input->keybit);
1866 
1867 	error = input_register_device(input);
1868 	if (error)
1869 		goto err_stop_dev;
1870 
1871 	mutex_lock(&video->device_list_lock);
1872 	list_for_each_entry(dev, &video->video_device_list, entry)
1873 		acpi_video_dev_add_notify_handler(dev);
1874 	mutex_unlock(&video->device_list_lock);
1875 
1876 	return 0;
1877 
1878 err_stop_dev:
1879 	acpi_video_bus_stop_devices(video);
1880 err_free_input:
1881 	input_free_device(input);
1882 	video->input = NULL;
1883 out:
1884 	return error;
1885 }
1886 
1887 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1888 {
1889 	if (dev->flags.notify) {
1890 		acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1891 					   acpi_video_device_notify);
1892 		dev->flags.notify = 0;
1893 	}
1894 }
1895 
1896 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1897 {
1898 	struct acpi_video_device *dev;
1899 
1900 	mutex_lock(&video->device_list_lock);
1901 	list_for_each_entry(dev, &video->video_device_list, entry)
1902 		acpi_video_dev_remove_notify_handler(dev);
1903 	mutex_unlock(&video->device_list_lock);
1904 
1905 	acpi_video_bus_stop_devices(video);
1906 	input_unregister_device(video->input);
1907 	video->input = NULL;
1908 }
1909 
1910 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1911 {
1912 	struct acpi_video_device *dev, *next;
1913 
1914 	mutex_lock(&video->device_list_lock);
1915 	list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1916 		list_del(&dev->entry);
1917 		kfree(dev);
1918 	}
1919 	mutex_unlock(&video->device_list_lock);
1920 
1921 	return 0;
1922 }
1923 
1924 static int instance;
1925 
1926 static int acpi_video_bus_add(struct acpi_device *device)
1927 {
1928 	struct acpi_video_bus *video;
1929 	int error;
1930 	acpi_status status;
1931 
1932 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1933 				device->parent->handle, 1,
1934 				acpi_video_bus_match, NULL,
1935 				device, NULL);
1936 	if (status == AE_ALREADY_EXISTS) {
1937 		printk(KERN_WARNING FW_BUG
1938 			"Duplicate ACPI video bus devices for the"
1939 			" same VGA controller, please try module "
1940 			"parameter \"video.allow_duplicates=1\""
1941 			"if the current driver doesn't work.\n");
1942 		if (!allow_duplicates)
1943 			return -ENODEV;
1944 	}
1945 
1946 	video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1947 	if (!video)
1948 		return -ENOMEM;
1949 
1950 	/* a hack to fix the duplicate name "VID" problem on T61 */
1951 	if (!strcmp(device->pnp.bus_id, "VID")) {
1952 		if (instance)
1953 			device->pnp.bus_id[3] = '0' + instance;
1954 		instance++;
1955 	}
1956 	/* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1957 	if (!strcmp(device->pnp.bus_id, "VGA")) {
1958 		if (instance)
1959 			device->pnp.bus_id[3] = '0' + instance;
1960 		instance++;
1961 	}
1962 
1963 	video->device = device;
1964 	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1965 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1966 	device->driver_data = video;
1967 
1968 	acpi_video_bus_find_cap(video);
1969 	error = acpi_video_bus_check(video);
1970 	if (error)
1971 		goto err_free_video;
1972 
1973 	mutex_init(&video->device_list_lock);
1974 	INIT_LIST_HEAD(&video->video_device_list);
1975 
1976 	error = acpi_video_bus_get_devices(video, device);
1977 	if (error)
1978 		goto err_put_video;
1979 
1980 	printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1981 	       ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1982 	       video->flags.multihead ? "yes" : "no",
1983 	       video->flags.rom ? "yes" : "no",
1984 	       video->flags.post ? "yes" : "no");
1985 	mutex_lock(&video_list_lock);
1986 	list_add_tail(&video->entry, &video_bus_head);
1987 	mutex_unlock(&video_list_lock);
1988 
1989 	acpi_video_bus_register_backlight(video);
1990 	acpi_video_bus_add_notify_handler(video);
1991 
1992 	return 0;
1993 
1994 err_put_video:
1995 	acpi_video_bus_put_devices(video);
1996 	kfree(video->attached_array);
1997 err_free_video:
1998 	kfree(video);
1999 	device->driver_data = NULL;
2000 
2001 	return error;
2002 }
2003 
2004 static int acpi_video_bus_remove(struct acpi_device *device)
2005 {
2006 	struct acpi_video_bus *video = NULL;
2007 
2008 
2009 	if (!device || !acpi_driver_data(device))
2010 		return -EINVAL;
2011 
2012 	video = acpi_driver_data(device);
2013 
2014 	acpi_video_bus_remove_notify_handler(video);
2015 	acpi_video_bus_unregister_backlight(video);
2016 	acpi_video_bus_put_devices(video);
2017 
2018 	mutex_lock(&video_list_lock);
2019 	list_del(&video->entry);
2020 	mutex_unlock(&video_list_lock);
2021 
2022 	kfree(video->attached_array);
2023 	kfree(video);
2024 
2025 	return 0;
2026 }
2027 
2028 static int __init is_i740(struct pci_dev *dev)
2029 {
2030 	if (dev->device == 0x00D1)
2031 		return 1;
2032 	if (dev->device == 0x7000)
2033 		return 1;
2034 	return 0;
2035 }
2036 
2037 static int __init intel_opregion_present(void)
2038 {
2039 	int opregion = 0;
2040 	struct pci_dev *dev = NULL;
2041 	u32 address;
2042 
2043 	for_each_pci_dev(dev) {
2044 		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2045 			continue;
2046 		if (dev->vendor != PCI_VENDOR_ID_INTEL)
2047 			continue;
2048 		/* We don't want to poke around undefined i740 registers */
2049 		if (is_i740(dev))
2050 			continue;
2051 		pci_read_config_dword(dev, 0xfc, &address);
2052 		if (!address)
2053 			continue;
2054 		opregion = 1;
2055 	}
2056 	return opregion;
2057 }
2058 
2059 int acpi_video_register(void)
2060 {
2061 	int ret = 0;
2062 
2063 	mutex_lock(&register_count_mutex);
2064 	if (register_count) {
2065 		/*
2066 		 * if the function of acpi_video_register is already called,
2067 		 * don't register the acpi_vide_bus again and return no error.
2068 		 */
2069 		goto leave;
2070 	}
2071 
2072 	dmi_check_system(video_dmi_table);
2073 
2074 	ret = acpi_bus_register_driver(&acpi_video_bus);
2075 	if (ret)
2076 		goto leave;
2077 
2078 	/*
2079 	 * When the acpi_video_bus is loaded successfully, increase
2080 	 * the counter reference.
2081 	 */
2082 	register_count = 1;
2083 
2084 leave:
2085 	mutex_unlock(&register_count_mutex);
2086 	return ret;
2087 }
2088 EXPORT_SYMBOL(acpi_video_register);
2089 
2090 void acpi_video_unregister(void)
2091 {
2092 	mutex_lock(&register_count_mutex);
2093 	if (register_count) {
2094 		acpi_bus_unregister_driver(&acpi_video_bus);
2095 		register_count = 0;
2096 	}
2097 	mutex_unlock(&register_count_mutex);
2098 }
2099 EXPORT_SYMBOL(acpi_video_unregister);
2100 
2101 void acpi_video_unregister_backlight(void)
2102 {
2103 	struct acpi_video_bus *video;
2104 
2105 	mutex_lock(&register_count_mutex);
2106 	if (register_count) {
2107 		mutex_lock(&video_list_lock);
2108 		list_for_each_entry(video, &video_bus_head, entry)
2109 			acpi_video_bus_unregister_backlight(video);
2110 		mutex_unlock(&video_list_lock);
2111 	}
2112 	mutex_unlock(&register_count_mutex);
2113 }
2114 
2115 bool acpi_video_handles_brightness_key_presses(void)
2116 {
2117 	bool have_video_busses;
2118 
2119 	mutex_lock(&video_list_lock);
2120 	have_video_busses = !list_empty(&video_bus_head);
2121 	mutex_unlock(&video_list_lock);
2122 
2123 	return have_video_busses &&
2124 	       (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2125 }
2126 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2127 
2128 /*
2129  * This is kind of nasty. Hardware using Intel chipsets may require
2130  * the video opregion code to be run first in order to initialise
2131  * state before any ACPI video calls are made. To handle this we defer
2132  * registration of the video class until the opregion code has run.
2133  */
2134 
2135 static int __init acpi_video_init(void)
2136 {
2137 	/*
2138 	 * Let the module load even if ACPI is disabled (e.g. due to
2139 	 * a broken BIOS) so that i915.ko can still be loaded on such
2140 	 * old systems without an AcpiOpRegion.
2141 	 *
2142 	 * acpi_video_register() will report -ENODEV later as well due
2143 	 * to acpi_disabled when i915.ko tries to register itself afterwards.
2144 	 */
2145 	if (acpi_disabled)
2146 		return 0;
2147 
2148 	if (intel_opregion_present())
2149 		return 0;
2150 
2151 	return acpi_video_register();
2152 }
2153 
2154 static void __exit acpi_video_exit(void)
2155 {
2156 	acpi_video_detect_exit();
2157 	acpi_video_unregister();
2158 
2159 	return;
2160 }
2161 
2162 module_init(acpi_video_init);
2163 module_exit(acpi_video_exit);
2164