xref: /openbmc/linux/drivers/acpi/acpi_video.c (revision 93df8a1e)
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  *  You should have received a copy of the GNU General Public License along
21  *  with this program; if not, write to the Free Software Foundation, Inc.,
22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
23  *
24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25  */
26 
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/init.h>
30 #include <linux/types.h>
31 #include <linux/list.h>
32 #include <linux/mutex.h>
33 #include <linux/input.h>
34 #include <linux/backlight.h>
35 #include <linux/thermal.h>
36 #include <linux/sort.h>
37 #include <linux/pci.h>
38 #include <linux/pci_ids.h>
39 #include <linux/slab.h>
40 #include <linux/dmi.h>
41 #include <linux/suspend.h>
42 #include <linux/acpi.h>
43 #include <acpi/video.h>
44 #include <asm/uaccess.h>
45 
46 #define PREFIX "ACPI: "
47 
48 #define ACPI_VIDEO_BUS_NAME		"Video Bus"
49 #define ACPI_VIDEO_DEVICE_NAME		"Video Device"
50 #define ACPI_VIDEO_NOTIFY_SWITCH	0x80
51 #define ACPI_VIDEO_NOTIFY_PROBE		0x81
52 #define ACPI_VIDEO_NOTIFY_CYCLE		0x82
53 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT	0x83
54 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT	0x84
55 
56 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS	0x85
57 #define	ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS	0x86
58 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS	0x87
59 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS	0x88
60 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF		0x89
61 
62 #define MAX_NAME_LEN	20
63 
64 #define _COMPONENT		ACPI_VIDEO_COMPONENT
65 ACPI_MODULE_NAME("video");
66 
67 MODULE_AUTHOR("Bruno Ducrot");
68 MODULE_DESCRIPTION("ACPI Video Driver");
69 MODULE_LICENSE("GPL");
70 
71 static bool brightness_switch_enabled = 1;
72 module_param(brightness_switch_enabled, bool, 0644);
73 
74 /*
75  * By default, we don't allow duplicate ACPI video bus devices
76  * under the same VGA controller
77  */
78 static bool allow_duplicates;
79 module_param(allow_duplicates, bool, 0644);
80 
81 static int disable_backlight_sysfs_if = -1;
82 module_param(disable_backlight_sysfs_if, int, 0444);
83 
84 static int register_count;
85 static DEFINE_MUTEX(register_count_mutex);
86 static struct mutex video_list_lock;
87 static struct list_head video_bus_head;
88 static int acpi_video_bus_add(struct acpi_device *device);
89 static int acpi_video_bus_remove(struct acpi_device *device);
90 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
91 void acpi_video_detect_exit(void);
92 
93 static const struct acpi_device_id video_device_ids[] = {
94 	{ACPI_VIDEO_HID, 0},
95 	{"", 0},
96 };
97 MODULE_DEVICE_TABLE(acpi, video_device_ids);
98 
99 static struct acpi_driver acpi_video_bus = {
100 	.name = "video",
101 	.class = ACPI_VIDEO_CLASS,
102 	.ids = video_device_ids,
103 	.ops = {
104 		.add = acpi_video_bus_add,
105 		.remove = acpi_video_bus_remove,
106 		.notify = acpi_video_bus_notify,
107 		},
108 };
109 
110 struct acpi_video_bus_flags {
111 	u8 multihead:1;		/* can switch video heads */
112 	u8 rom:1;		/* can retrieve a video rom */
113 	u8 post:1;		/* can configure the head to */
114 	u8 reserved:5;
115 };
116 
117 struct acpi_video_bus_cap {
118 	u8 _DOS:1;		/* Enable/Disable output switching */
119 	u8 _DOD:1;		/* Enumerate all devices attached to display adapter */
120 	u8 _ROM:1;		/* Get ROM Data */
121 	u8 _GPD:1;		/* Get POST Device */
122 	u8 _SPD:1;		/* Set POST Device */
123 	u8 _VPO:1;		/* Video POST Options */
124 	u8 reserved:2;
125 };
126 
127 struct acpi_video_device_attrib {
128 	u32 display_index:4;	/* A zero-based instance of the Display */
129 	u32 display_port_attachment:4;	/* This field differentiates the display type */
130 	u32 display_type:4;	/* Describe the specific type in use */
131 	u32 vendor_specific:4;	/* Chipset Vendor Specific */
132 	u32 bios_can_detect:1;	/* BIOS can detect the device */
133 	u32 depend_on_vga:1;	/* Non-VGA output device whose power is related to
134 				   the VGA device. */
135 	u32 pipe_id:3;		/* For VGA multiple-head devices. */
136 	u32 reserved:10;	/* Must be 0 */
137 	u32 device_id_scheme:1;	/* Device ID Scheme */
138 };
139 
140 struct acpi_video_enumerated_device {
141 	union {
142 		u32 int_val;
143 		struct acpi_video_device_attrib attrib;
144 	} value;
145 	struct acpi_video_device *bind_info;
146 };
147 
148 struct acpi_video_bus {
149 	struct acpi_device *device;
150 	bool backlight_registered;
151 	u8 dos_setting;
152 	struct acpi_video_enumerated_device *attached_array;
153 	u8 attached_count;
154 	u8 child_count;
155 	struct acpi_video_bus_cap cap;
156 	struct acpi_video_bus_flags flags;
157 	struct list_head video_device_list;
158 	struct mutex device_list_lock;	/* protects video_device_list */
159 	struct list_head entry;
160 	struct input_dev *input;
161 	char phys[32];	/* for input device */
162 	struct notifier_block pm_nb;
163 };
164 
165 struct acpi_video_device_flags {
166 	u8 crt:1;
167 	u8 lcd:1;
168 	u8 tvout:1;
169 	u8 dvi:1;
170 	u8 bios:1;
171 	u8 unknown:1;
172 	u8 notify:1;
173 	u8 reserved:1;
174 };
175 
176 struct acpi_video_device_cap {
177 	u8 _ADR:1;		/* Return the unique ID */
178 	u8 _BCL:1;		/* Query list of brightness control levels supported */
179 	u8 _BCM:1;		/* Set the brightness level */
180 	u8 _BQC:1;		/* Get current brightness level */
181 	u8 _BCQ:1;		/* Some buggy BIOS uses _BCQ instead of _BQC */
182 	u8 _DDC:1;		/* Return the EDID for this device */
183 };
184 
185 struct acpi_video_brightness_flags {
186 	u8 _BCL_no_ac_battery_levels:1;	/* no AC/Battery levels in _BCL */
187 	u8 _BCL_reversed:1;		/* _BCL package is in a reversed order */
188 	u8 _BQC_use_index:1;		/* _BQC returns an index value */
189 };
190 
191 struct acpi_video_device_brightness {
192 	int curr;
193 	int count;
194 	int *levels;
195 	struct acpi_video_brightness_flags flags;
196 };
197 
198 struct acpi_video_device {
199 	unsigned long device_id;
200 	struct acpi_video_device_flags flags;
201 	struct acpi_video_device_cap cap;
202 	struct list_head entry;
203 	struct delayed_work switch_brightness_work;
204 	int switch_brightness_event;
205 	struct acpi_video_bus *video;
206 	struct acpi_device *dev;
207 	struct acpi_video_device_brightness *brightness;
208 	struct backlight_device *backlight;
209 	struct thermal_cooling_device *cooling_dev;
210 };
211 
212 static const char device_decode[][30] = {
213 	"motherboard VGA device",
214 	"PCI VGA device",
215 	"AGP VGA device",
216 	"UNKNOWN",
217 };
218 
219 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
220 static void acpi_video_device_rebind(struct acpi_video_bus *video);
221 static void acpi_video_device_bind(struct acpi_video_bus *video,
222 				   struct acpi_video_device *device);
223 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
224 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
225 			int level);
226 static int acpi_video_device_lcd_get_level_current(
227 			struct acpi_video_device *device,
228 			unsigned long long *level, bool raw);
229 static int acpi_video_get_next_level(struct acpi_video_device *device,
230 				     u32 level_current, u32 event);
231 static void acpi_video_switch_brightness(struct work_struct *work);
232 
233 /* backlight device sysfs support */
234 static int acpi_video_get_brightness(struct backlight_device *bd)
235 {
236 	unsigned long long cur_level;
237 	int i;
238 	struct acpi_video_device *vd = bl_get_data(bd);
239 
240 	if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
241 		return -EINVAL;
242 	for (i = 2; i < vd->brightness->count; i++) {
243 		if (vd->brightness->levels[i] == cur_level)
244 			/*
245 			 * The first two entries are special - see page 575
246 			 * of the ACPI spec 3.0
247 			 */
248 			return i - 2;
249 	}
250 	return 0;
251 }
252 
253 static int acpi_video_set_brightness(struct backlight_device *bd)
254 {
255 	int request_level = bd->props.brightness + 2;
256 	struct acpi_video_device *vd = bl_get_data(bd);
257 
258 	cancel_delayed_work(&vd->switch_brightness_work);
259 	return acpi_video_device_lcd_set_level(vd,
260 				vd->brightness->levels[request_level]);
261 }
262 
263 static const struct backlight_ops acpi_backlight_ops = {
264 	.get_brightness = acpi_video_get_brightness,
265 	.update_status  = acpi_video_set_brightness,
266 };
267 
268 /* thermal cooling device callbacks */
269 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
270 			       long *state)
271 {
272 	struct acpi_device *device = cooling_dev->devdata;
273 	struct acpi_video_device *video = acpi_driver_data(device);
274 
275 	*state = video->brightness->count - 3;
276 	return 0;
277 }
278 
279 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
280 			       long *state)
281 {
282 	struct acpi_device *device = cooling_dev->devdata;
283 	struct acpi_video_device *video = acpi_driver_data(device);
284 	unsigned long long level;
285 	int offset;
286 
287 	if (acpi_video_device_lcd_get_level_current(video, &level, false))
288 		return -EINVAL;
289 	for (offset = 2; offset < video->brightness->count; offset++)
290 		if (level == video->brightness->levels[offset]) {
291 			*state = video->brightness->count - offset - 1;
292 			return 0;
293 		}
294 
295 	return -EINVAL;
296 }
297 
298 static int
299 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
300 {
301 	struct acpi_device *device = cooling_dev->devdata;
302 	struct acpi_video_device *video = acpi_driver_data(device);
303 	int level;
304 
305 	if (state >= video->brightness->count - 2)
306 		return -EINVAL;
307 
308 	state = video->brightness->count - state;
309 	level = video->brightness->levels[state - 1];
310 	return acpi_video_device_lcd_set_level(video, level);
311 }
312 
313 static const struct thermal_cooling_device_ops video_cooling_ops = {
314 	.get_max_state = video_get_max_state,
315 	.get_cur_state = video_get_cur_state,
316 	.set_cur_state = video_set_cur_state,
317 };
318 
319 /*
320  * --------------------------------------------------------------------------
321  *                             Video Management
322  * --------------------------------------------------------------------------
323  */
324 
325 static int
326 acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
327 				   union acpi_object **levels)
328 {
329 	int status;
330 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
331 	union acpi_object *obj;
332 
333 
334 	*levels = NULL;
335 
336 	status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
337 	if (!ACPI_SUCCESS(status))
338 		return status;
339 	obj = (union acpi_object *)buffer.pointer;
340 	if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
341 		printk(KERN_ERR PREFIX "Invalid _BCL data\n");
342 		status = -EFAULT;
343 		goto err;
344 	}
345 
346 	*levels = obj;
347 
348 	return 0;
349 
350 err:
351 	kfree(buffer.pointer);
352 
353 	return status;
354 }
355 
356 static int
357 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
358 {
359 	int status;
360 	int state;
361 
362 	status = acpi_execute_simple_method(device->dev->handle,
363 					    "_BCM", level);
364 	if (ACPI_FAILURE(status)) {
365 		ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
366 		return -EIO;
367 	}
368 
369 	device->brightness->curr = level;
370 	for (state = 2; state < device->brightness->count; state++)
371 		if (level == device->brightness->levels[state]) {
372 			if (device->backlight)
373 				device->backlight->props.brightness = state - 2;
374 			return 0;
375 		}
376 
377 	ACPI_ERROR((AE_INFO, "Current brightness invalid"));
378 	return -EINVAL;
379 }
380 
381 /*
382  * For some buggy _BQC methods, we need to add a constant value to
383  * the _BQC return value to get the actual current brightness level
384  */
385 
386 static int bqc_offset_aml_bug_workaround;
387 static int video_set_bqc_offset(const struct dmi_system_id *d)
388 {
389 	bqc_offset_aml_bug_workaround = 9;
390 	return 0;
391 }
392 
393 static int video_disable_backlight_sysfs_if(
394 	const struct dmi_system_id *d)
395 {
396 	if (disable_backlight_sysfs_if == -1)
397 		disable_backlight_sysfs_if = 1;
398 	return 0;
399 }
400 
401 static struct dmi_system_id video_dmi_table[] = {
402 	/*
403 	 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
404 	 */
405 	{
406 	 .callback = video_set_bqc_offset,
407 	 .ident = "Acer Aspire 5720",
408 	 .matches = {
409 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
410 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
411 		},
412 	},
413 	{
414 	 .callback = video_set_bqc_offset,
415 	 .ident = "Acer Aspire 5710Z",
416 	 .matches = {
417 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
418 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
419 		},
420 	},
421 	{
422 	 .callback = video_set_bqc_offset,
423 	 .ident = "eMachines E510",
424 	 .matches = {
425 		DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
426 		DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
427 		},
428 	},
429 	{
430 	 .callback = video_set_bqc_offset,
431 	 .ident = "Acer Aspire 5315",
432 	 .matches = {
433 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
434 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
435 		},
436 	},
437 	{
438 	 .callback = video_set_bqc_offset,
439 	 .ident = "Acer Aspire 7720",
440 	 .matches = {
441 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
442 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
443 		},
444 	},
445 
446 	/*
447 	 * Some machines have a broken acpi-video interface for brightness
448 	 * control, but still need an acpi_video_device_lcd_set_level() call
449 	 * on resume to turn the backlight power on.  We Enable backlight
450 	 * control on these systems, but do not register a backlight sysfs
451 	 * as brightness control does not work.
452 	 */
453 	{
454 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
455 	 .callback = video_disable_backlight_sysfs_if,
456 	 .ident = "Toshiba Portege R830",
457 	 .matches = {
458 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
459 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
460 		},
461 	},
462 	{}
463 };
464 
465 static unsigned long long
466 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
467 			      unsigned long long bqc_value)
468 {
469 	unsigned long long level;
470 
471 	if (device->brightness->flags._BQC_use_index) {
472 		/*
473 		 * _BQC returns an index that doesn't account for
474 		 * the first 2 items with special meaning, so we need
475 		 * to compensate for that by offsetting ourselves
476 		 */
477 		if (device->brightness->flags._BCL_reversed)
478 			bqc_value = device->brightness->count - 3 - bqc_value;
479 
480 		level = device->brightness->levels[bqc_value + 2];
481 	} else {
482 		level = bqc_value;
483 	}
484 
485 	level += bqc_offset_aml_bug_workaround;
486 
487 	return level;
488 }
489 
490 static int
491 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
492 					unsigned long long *level, bool raw)
493 {
494 	acpi_status status = AE_OK;
495 	int i;
496 
497 	if (device->cap._BQC || device->cap._BCQ) {
498 		char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
499 
500 		status = acpi_evaluate_integer(device->dev->handle, buf,
501 						NULL, level);
502 		if (ACPI_SUCCESS(status)) {
503 			if (raw) {
504 				/*
505 				 * Caller has indicated he wants the raw
506 				 * value returned by _BQC, so don't furtherly
507 				 * mess with the value.
508 				 */
509 				return 0;
510 			}
511 
512 			*level = acpi_video_bqc_value_to_level(device, *level);
513 
514 			for (i = 2; i < device->brightness->count; i++)
515 				if (device->brightness->levels[i] == *level) {
516 					device->brightness->curr = *level;
517 					return 0;
518 				}
519 			/*
520 			 * BQC returned an invalid level.
521 			 * Stop using it.
522 			 */
523 			ACPI_WARNING((AE_INFO,
524 				      "%s returned an invalid level",
525 				      buf));
526 			device->cap._BQC = device->cap._BCQ = 0;
527 		} else {
528 			/*
529 			 * Fixme:
530 			 * should we return an error or ignore this failure?
531 			 * dev->brightness->curr is a cached value which stores
532 			 * the correct current backlight level in most cases.
533 			 * ACPI video backlight still works w/ buggy _BQC.
534 			 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
535 			 */
536 			ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
537 			device->cap._BQC = device->cap._BCQ = 0;
538 		}
539 	}
540 
541 	*level = device->brightness->curr;
542 	return 0;
543 }
544 
545 static int
546 acpi_video_device_EDID(struct acpi_video_device *device,
547 		       union acpi_object **edid, ssize_t length)
548 {
549 	int status;
550 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
551 	union acpi_object *obj;
552 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
553 	struct acpi_object_list args = { 1, &arg0 };
554 
555 
556 	*edid = NULL;
557 
558 	if (!device)
559 		return -ENODEV;
560 	if (length == 128)
561 		arg0.integer.value = 1;
562 	else if (length == 256)
563 		arg0.integer.value = 2;
564 	else
565 		return -EINVAL;
566 
567 	status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
568 	if (ACPI_FAILURE(status))
569 		return -ENODEV;
570 
571 	obj = buffer.pointer;
572 
573 	if (obj && obj->type == ACPI_TYPE_BUFFER)
574 		*edid = obj;
575 	else {
576 		printk(KERN_ERR PREFIX "Invalid _DDC data\n");
577 		status = -EFAULT;
578 		kfree(obj);
579 	}
580 
581 	return status;
582 }
583 
584 /* bus */
585 
586 /*
587  *  Arg:
588  *	video		: video bus device pointer
589  *	bios_flag	:
590  *		0.	The system BIOS should NOT automatically switch(toggle)
591  *			the active display output.
592  *		1.	The system BIOS should automatically switch (toggle) the
593  *			active display output. No switch event.
594  *		2.	The _DGS value should be locked.
595  *		3.	The system BIOS should not automatically switch (toggle) the
596  *			active display output, but instead generate the display switch
597  *			event notify code.
598  *	lcd_flag	:
599  *		0.	The system BIOS should automatically control the brightness level
600  *			of the LCD when the power changes from AC to DC
601  *		1.	The system BIOS should NOT automatically control the brightness
602  *			level of the LCD when the power changes from AC to DC.
603  *  Return Value:
604  *		-EINVAL	wrong arg.
605  */
606 
607 static int
608 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
609 {
610 	acpi_status status;
611 
612 	if (!video->cap._DOS)
613 		return 0;
614 
615 	if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
616 		return -EINVAL;
617 	video->dos_setting = (lcd_flag << 2) | bios_flag;
618 	status = acpi_execute_simple_method(video->device->handle, "_DOS",
619 					    (lcd_flag << 2) | bios_flag);
620 	if (ACPI_FAILURE(status))
621 		return -EIO;
622 
623 	return 0;
624 }
625 
626 /*
627  * Simple comparison function used to sort backlight levels.
628  */
629 
630 static int
631 acpi_video_cmp_level(const void *a, const void *b)
632 {
633 	return *(int *)a - *(int *)b;
634 }
635 
636 /*
637  * Decides if _BQC/_BCQ for this system is usable
638  *
639  * We do this by changing the level first and then read out the current
640  * brightness level, if the value does not match, find out if it is using
641  * index. If not, clear the _BQC/_BCQ capability.
642  */
643 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
644 				int max_level, int current_level)
645 {
646 	struct acpi_video_device_brightness *br = device->brightness;
647 	int result;
648 	unsigned long long level;
649 	int test_level;
650 
651 	/* don't mess with existing known broken systems */
652 	if (bqc_offset_aml_bug_workaround)
653 		return 0;
654 
655 	/*
656 	 * Some systems always report current brightness level as maximum
657 	 * through _BQC, we need to test another value for them.
658 	 */
659 	test_level = current_level == max_level ? br->levels[3] : max_level;
660 
661 	result = acpi_video_device_lcd_set_level(device, test_level);
662 	if (result)
663 		return result;
664 
665 	result = acpi_video_device_lcd_get_level_current(device, &level, true);
666 	if (result)
667 		return result;
668 
669 	if (level != test_level) {
670 		/* buggy _BQC found, need to find out if it uses index */
671 		if (level < br->count) {
672 			if (br->flags._BCL_reversed)
673 				level = br->count - 3 - level;
674 			if (br->levels[level + 2] == test_level)
675 				br->flags._BQC_use_index = 1;
676 		}
677 
678 		if (!br->flags._BQC_use_index)
679 			device->cap._BQC = device->cap._BCQ = 0;
680 	}
681 
682 	return 0;
683 }
684 
685 
686 /*
687  *  Arg:
688  *	device	: video output device (LCD, CRT, ..)
689  *
690  *  Return Value:
691  *	Maximum brightness level
692  *
693  *  Allocate and initialize device->brightness.
694  */
695 
696 static int
697 acpi_video_init_brightness(struct acpi_video_device *device)
698 {
699 	union acpi_object *obj = NULL;
700 	int i, max_level = 0, count = 0, level_ac_battery = 0;
701 	unsigned long long level, level_old;
702 	union acpi_object *o;
703 	struct acpi_video_device_brightness *br = NULL;
704 	int result = -EINVAL;
705 	u32 value;
706 
707 	if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
708 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
709 						"LCD brightness level\n"));
710 		goto out;
711 	}
712 
713 	if (obj->package.count < 2)
714 		goto out;
715 
716 	br = kzalloc(sizeof(*br), GFP_KERNEL);
717 	if (!br) {
718 		printk(KERN_ERR "can't allocate memory\n");
719 		result = -ENOMEM;
720 		goto out;
721 	}
722 
723 	br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
724 				GFP_KERNEL);
725 	if (!br->levels) {
726 		result = -ENOMEM;
727 		goto out_free;
728 	}
729 
730 	for (i = 0; i < obj->package.count; i++) {
731 		o = (union acpi_object *)&obj->package.elements[i];
732 		if (o->type != ACPI_TYPE_INTEGER) {
733 			printk(KERN_ERR PREFIX "Invalid data\n");
734 			continue;
735 		}
736 		value = (u32) o->integer.value;
737 		/* Skip duplicate entries */
738 		if (count > 2 && br->levels[count - 1] == value)
739 			continue;
740 
741 		br->levels[count] = value;
742 
743 		if (br->levels[count] > max_level)
744 			max_level = br->levels[count];
745 		count++;
746 	}
747 
748 	/*
749 	 * some buggy BIOS don't export the levels
750 	 * when machine is on AC/Battery in _BCL package.
751 	 * In this case, the first two elements in _BCL packages
752 	 * are also supported brightness levels that OS should take care of.
753 	 */
754 	for (i = 2; i < count; i++) {
755 		if (br->levels[i] == br->levels[0])
756 			level_ac_battery++;
757 		if (br->levels[i] == br->levels[1])
758 			level_ac_battery++;
759 	}
760 
761 	if (level_ac_battery < 2) {
762 		level_ac_battery = 2 - level_ac_battery;
763 		br->flags._BCL_no_ac_battery_levels = 1;
764 		for (i = (count - 1 + level_ac_battery); i >= 2; i--)
765 			br->levels[i] = br->levels[i - level_ac_battery];
766 		count += level_ac_battery;
767 	} else if (level_ac_battery > 2)
768 		ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
769 
770 	/* Check if the _BCL package is in a reversed order */
771 	if (max_level == br->levels[2]) {
772 		br->flags._BCL_reversed = 1;
773 		sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
774 			acpi_video_cmp_level, NULL);
775 	} else if (max_level != br->levels[count - 1])
776 		ACPI_ERROR((AE_INFO,
777 			    "Found unordered _BCL package"));
778 
779 	br->count = count;
780 	device->brightness = br;
781 
782 	/* _BQC uses INDEX while _BCL uses VALUE in some laptops */
783 	br->curr = level = max_level;
784 
785 	if (!device->cap._BQC)
786 		goto set_level;
787 
788 	result = acpi_video_device_lcd_get_level_current(device,
789 							 &level_old, true);
790 	if (result)
791 		goto out_free_levels;
792 
793 	result = acpi_video_bqc_quirk(device, max_level, level_old);
794 	if (result)
795 		goto out_free_levels;
796 	/*
797 	 * cap._BQC may get cleared due to _BQC is found to be broken
798 	 * in acpi_video_bqc_quirk, so check again here.
799 	 */
800 	if (!device->cap._BQC)
801 		goto set_level;
802 
803 	level = acpi_video_bqc_value_to_level(device, level_old);
804 	/*
805 	 * On some buggy laptops, _BQC returns an uninitialized
806 	 * value when invoked for the first time, i.e.
807 	 * level_old is invalid (no matter whether it's a level
808 	 * or an index). Set the backlight to max_level in this case.
809 	 */
810 	for (i = 2; i < br->count; i++)
811 		if (level == br->levels[i])
812 			break;
813 	if (i == br->count || !level)
814 		level = max_level;
815 
816 set_level:
817 	result = acpi_video_device_lcd_set_level(device, level);
818 	if (result)
819 		goto out_free_levels;
820 
821 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
822 			  "found %d brightness levels\n", count - 2));
823 	kfree(obj);
824 	return result;
825 
826 out_free_levels:
827 	kfree(br->levels);
828 out_free:
829 	kfree(br);
830 out:
831 	device->brightness = NULL;
832 	kfree(obj);
833 	return result;
834 }
835 
836 /*
837  *  Arg:
838  *	device	: video output device (LCD, CRT, ..)
839  *
840  *  Return Value:
841  *	None
842  *
843  *  Find out all required AML methods defined under the output
844  *  device.
845  */
846 
847 static void acpi_video_device_find_cap(struct acpi_video_device *device)
848 {
849 	if (acpi_has_method(device->dev->handle, "_ADR"))
850 		device->cap._ADR = 1;
851 	if (acpi_has_method(device->dev->handle, "_BCL"))
852 		device->cap._BCL = 1;
853 	if (acpi_has_method(device->dev->handle, "_BCM"))
854 		device->cap._BCM = 1;
855 	if (acpi_has_method(device->dev->handle, "_BQC")) {
856 		device->cap._BQC = 1;
857 	} else if (acpi_has_method(device->dev->handle, "_BCQ")) {
858 		printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
859 		device->cap._BCQ = 1;
860 	}
861 
862 	if (acpi_has_method(device->dev->handle, "_DDC"))
863 		device->cap._DDC = 1;
864 }
865 
866 /*
867  *  Arg:
868  *	device	: video output device (VGA)
869  *
870  *  Return Value:
871  *	None
872  *
873  *  Find out all required AML methods defined under the video bus device.
874  */
875 
876 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
877 {
878 	if (acpi_has_method(video->device->handle, "_DOS"))
879 		video->cap._DOS = 1;
880 	if (acpi_has_method(video->device->handle, "_DOD"))
881 		video->cap._DOD = 1;
882 	if (acpi_has_method(video->device->handle, "_ROM"))
883 		video->cap._ROM = 1;
884 	if (acpi_has_method(video->device->handle, "_GPD"))
885 		video->cap._GPD = 1;
886 	if (acpi_has_method(video->device->handle, "_SPD"))
887 		video->cap._SPD = 1;
888 	if (acpi_has_method(video->device->handle, "_VPO"))
889 		video->cap._VPO = 1;
890 }
891 
892 /*
893  * Check whether the video bus device has required AML method to
894  * support the desired features
895  */
896 
897 static int acpi_video_bus_check(struct acpi_video_bus *video)
898 {
899 	acpi_status status = -ENOENT;
900 	struct pci_dev *dev;
901 
902 	if (!video)
903 		return -EINVAL;
904 
905 	dev = acpi_get_pci_dev(video->device->handle);
906 	if (!dev)
907 		return -ENODEV;
908 	pci_dev_put(dev);
909 
910 	/*
911 	 * Since there is no HID, CID and so on for VGA driver, we have
912 	 * to check well known required nodes.
913 	 */
914 
915 	/* Does this device support video switching? */
916 	if (video->cap._DOS || video->cap._DOD) {
917 		if (!video->cap._DOS) {
918 			printk(KERN_WARNING FW_BUG
919 				"ACPI(%s) defines _DOD but not _DOS\n",
920 				acpi_device_bid(video->device));
921 		}
922 		video->flags.multihead = 1;
923 		status = 0;
924 	}
925 
926 	/* Does this device support retrieving a video ROM? */
927 	if (video->cap._ROM) {
928 		video->flags.rom = 1;
929 		status = 0;
930 	}
931 
932 	/* Does this device support configuring which video device to POST? */
933 	if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
934 		video->flags.post = 1;
935 		status = 0;
936 	}
937 
938 	return status;
939 }
940 
941 /*
942  * --------------------------------------------------------------------------
943  *                               Driver Interface
944  * --------------------------------------------------------------------------
945  */
946 
947 /* device interface */
948 static struct acpi_video_device_attrib *
949 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
950 {
951 	struct acpi_video_enumerated_device *ids;
952 	int i;
953 
954 	for (i = 0; i < video->attached_count; i++) {
955 		ids = &video->attached_array[i];
956 		if ((ids->value.int_val & 0xffff) == device_id)
957 			return &ids->value.attrib;
958 	}
959 
960 	return NULL;
961 }
962 
963 static int
964 acpi_video_get_device_type(struct acpi_video_bus *video,
965 			   unsigned long device_id)
966 {
967 	struct acpi_video_enumerated_device *ids;
968 	int i;
969 
970 	for (i = 0; i < video->attached_count; i++) {
971 		ids = &video->attached_array[i];
972 		if ((ids->value.int_val & 0xffff) == device_id)
973 			return ids->value.int_val;
974 	}
975 
976 	return 0;
977 }
978 
979 static int
980 acpi_video_bus_get_one_device(struct acpi_device *device,
981 			      struct acpi_video_bus *video)
982 {
983 	unsigned long long device_id;
984 	int status, device_type;
985 	struct acpi_video_device *data;
986 	struct acpi_video_device_attrib *attribute;
987 
988 	status =
989 	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
990 	/* Some device omits _ADR, we skip them instead of fail */
991 	if (ACPI_FAILURE(status))
992 		return 0;
993 
994 	data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
995 	if (!data)
996 		return -ENOMEM;
997 
998 	strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
999 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1000 	device->driver_data = data;
1001 
1002 	data->device_id = device_id;
1003 	data->video = video;
1004 	data->dev = device;
1005 	INIT_DELAYED_WORK(&data->switch_brightness_work,
1006 			  acpi_video_switch_brightness);
1007 
1008 	attribute = acpi_video_get_device_attr(video, device_id);
1009 
1010 	if (attribute && attribute->device_id_scheme) {
1011 		switch (attribute->display_type) {
1012 		case ACPI_VIDEO_DISPLAY_CRT:
1013 			data->flags.crt = 1;
1014 			break;
1015 		case ACPI_VIDEO_DISPLAY_TV:
1016 			data->flags.tvout = 1;
1017 			break;
1018 		case ACPI_VIDEO_DISPLAY_DVI:
1019 			data->flags.dvi = 1;
1020 			break;
1021 		case ACPI_VIDEO_DISPLAY_LCD:
1022 			data->flags.lcd = 1;
1023 			break;
1024 		default:
1025 			data->flags.unknown = 1;
1026 			break;
1027 		}
1028 		if (attribute->bios_can_detect)
1029 			data->flags.bios = 1;
1030 	} else {
1031 		/* Check for legacy IDs */
1032 		device_type = acpi_video_get_device_type(video, device_id);
1033 		/* Ignore bits 16 and 18-20 */
1034 		switch (device_type & 0xffe2ffff) {
1035 		case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1036 			data->flags.crt = 1;
1037 			break;
1038 		case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1039 			data->flags.lcd = 1;
1040 			break;
1041 		case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1042 			data->flags.tvout = 1;
1043 			break;
1044 		default:
1045 			data->flags.unknown = 1;
1046 		}
1047 	}
1048 
1049 	acpi_video_device_bind(video, data);
1050 	acpi_video_device_find_cap(data);
1051 
1052 	mutex_lock(&video->device_list_lock);
1053 	list_add_tail(&data->entry, &video->video_device_list);
1054 	mutex_unlock(&video->device_list_lock);
1055 
1056 	return status;
1057 }
1058 
1059 /*
1060  *  Arg:
1061  *	video	: video bus device
1062  *
1063  *  Return:
1064  *	none
1065  *
1066  *  Enumerate the video device list of the video bus,
1067  *  bind the ids with the corresponding video devices
1068  *  under the video bus.
1069  */
1070 
1071 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1072 {
1073 	struct acpi_video_device *dev;
1074 
1075 	mutex_lock(&video->device_list_lock);
1076 
1077 	list_for_each_entry(dev, &video->video_device_list, entry)
1078 		acpi_video_device_bind(video, dev);
1079 
1080 	mutex_unlock(&video->device_list_lock);
1081 }
1082 
1083 /*
1084  *  Arg:
1085  *	video	: video bus device
1086  *	device	: video output device under the video
1087  *		bus
1088  *
1089  *  Return:
1090  *	none
1091  *
1092  *  Bind the ids with the corresponding video devices
1093  *  under the video bus.
1094  */
1095 
1096 static void
1097 acpi_video_device_bind(struct acpi_video_bus *video,
1098 		       struct acpi_video_device *device)
1099 {
1100 	struct acpi_video_enumerated_device *ids;
1101 	int i;
1102 
1103 	for (i = 0; i < video->attached_count; i++) {
1104 		ids = &video->attached_array[i];
1105 		if (device->device_id == (ids->value.int_val & 0xffff)) {
1106 			ids->bind_info = device;
1107 			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1108 		}
1109 	}
1110 }
1111 
1112 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1113 {
1114 	struct acpi_video_bus *video = device->video;
1115 	int i;
1116 
1117 	/*
1118 	 * If we have a broken _DOD or we have more than 8 output devices
1119 	 * under the graphics controller node that we can't proper deal with
1120 	 * in the operation region code currently, no need to test.
1121 	 */
1122 	if (!video->attached_count || video->child_count > 8)
1123 		return true;
1124 
1125 	for (i = 0; i < video->attached_count; i++) {
1126 		if ((video->attached_array[i].value.int_val & 0xfff) ==
1127 		    (device->device_id & 0xfff))
1128 			return true;
1129 	}
1130 
1131 	return false;
1132 }
1133 
1134 /*
1135  *  Arg:
1136  *	video	: video bus device
1137  *
1138  *  Return:
1139  *	< 0	: error
1140  *
1141  *  Call _DOD to enumerate all devices attached to display adapter
1142  *
1143  */
1144 
1145 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1146 {
1147 	int status;
1148 	int count;
1149 	int i;
1150 	struct acpi_video_enumerated_device *active_list;
1151 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1152 	union acpi_object *dod = NULL;
1153 	union acpi_object *obj;
1154 
1155 	status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1156 	if (!ACPI_SUCCESS(status)) {
1157 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1158 		return status;
1159 	}
1160 
1161 	dod = buffer.pointer;
1162 	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1163 		ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1164 		status = -EFAULT;
1165 		goto out;
1166 	}
1167 
1168 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1169 			  dod->package.count));
1170 
1171 	active_list = kcalloc(1 + dod->package.count,
1172 			      sizeof(struct acpi_video_enumerated_device),
1173 			      GFP_KERNEL);
1174 	if (!active_list) {
1175 		status = -ENOMEM;
1176 		goto out;
1177 	}
1178 
1179 	count = 0;
1180 	for (i = 0; i < dod->package.count; i++) {
1181 		obj = &dod->package.elements[i];
1182 
1183 		if (obj->type != ACPI_TYPE_INTEGER) {
1184 			printk(KERN_ERR PREFIX
1185 				"Invalid _DOD data in element %d\n", i);
1186 			continue;
1187 		}
1188 
1189 		active_list[count].value.int_val = obj->integer.value;
1190 		active_list[count].bind_info = NULL;
1191 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1192 				  (int)obj->integer.value));
1193 		count++;
1194 	}
1195 
1196 	kfree(video->attached_array);
1197 
1198 	video->attached_array = active_list;
1199 	video->attached_count = count;
1200 
1201 out:
1202 	kfree(buffer.pointer);
1203 	return status;
1204 }
1205 
1206 static int
1207 acpi_video_get_next_level(struct acpi_video_device *device,
1208 			  u32 level_current, u32 event)
1209 {
1210 	int min, max, min_above, max_below, i, l, delta = 255;
1211 	max = max_below = 0;
1212 	min = min_above = 255;
1213 	/* Find closest level to level_current */
1214 	for (i = 2; i < device->brightness->count; i++) {
1215 		l = device->brightness->levels[i];
1216 		if (abs(l - level_current) < abs(delta)) {
1217 			delta = l - level_current;
1218 			if (!delta)
1219 				break;
1220 		}
1221 	}
1222 	/* Ajust level_current to closest available level */
1223 	level_current += delta;
1224 	for (i = 2; i < device->brightness->count; i++) {
1225 		l = device->brightness->levels[i];
1226 		if (l < min)
1227 			min = l;
1228 		if (l > max)
1229 			max = l;
1230 		if (l < min_above && l > level_current)
1231 			min_above = l;
1232 		if (l > max_below && l < level_current)
1233 			max_below = l;
1234 	}
1235 
1236 	switch (event) {
1237 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1238 		return (level_current < max) ? min_above : min;
1239 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1240 		return (level_current < max) ? min_above : max;
1241 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1242 		return (level_current > min) ? max_below : min;
1243 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1244 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1245 		return 0;
1246 	default:
1247 		return level_current;
1248 	}
1249 }
1250 
1251 static void
1252 acpi_video_switch_brightness(struct work_struct *work)
1253 {
1254 	struct acpi_video_device *device = container_of(to_delayed_work(work),
1255 			     struct acpi_video_device, switch_brightness_work);
1256 	unsigned long long level_current, level_next;
1257 	int event = device->switch_brightness_event;
1258 	int result = -EINVAL;
1259 
1260 	/* no warning message if acpi_backlight=vendor or a quirk is used */
1261 	if (!device->backlight)
1262 		return;
1263 
1264 	if (!device->brightness)
1265 		goto out;
1266 
1267 	result = acpi_video_device_lcd_get_level_current(device,
1268 							 &level_current,
1269 							 false);
1270 	if (result)
1271 		goto out;
1272 
1273 	level_next = acpi_video_get_next_level(device, level_current, event);
1274 
1275 	result = acpi_video_device_lcd_set_level(device, level_next);
1276 
1277 	if (!result)
1278 		backlight_force_update(device->backlight,
1279 				       BACKLIGHT_UPDATE_HOTKEY);
1280 
1281 out:
1282 	if (result)
1283 		printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1284 }
1285 
1286 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1287 			void **edid)
1288 {
1289 	struct acpi_video_bus *video;
1290 	struct acpi_video_device *video_device;
1291 	union acpi_object *buffer = NULL;
1292 	acpi_status status;
1293 	int i, length;
1294 
1295 	if (!device || !acpi_driver_data(device))
1296 		return -EINVAL;
1297 
1298 	video = acpi_driver_data(device);
1299 
1300 	for (i = 0; i < video->attached_count; i++) {
1301 		video_device = video->attached_array[i].bind_info;
1302 		length = 256;
1303 
1304 		if (!video_device)
1305 			continue;
1306 
1307 		if (!video_device->cap._DDC)
1308 			continue;
1309 
1310 		if (type) {
1311 			switch (type) {
1312 			case ACPI_VIDEO_DISPLAY_CRT:
1313 				if (!video_device->flags.crt)
1314 					continue;
1315 				break;
1316 			case ACPI_VIDEO_DISPLAY_TV:
1317 				if (!video_device->flags.tvout)
1318 					continue;
1319 				break;
1320 			case ACPI_VIDEO_DISPLAY_DVI:
1321 				if (!video_device->flags.dvi)
1322 					continue;
1323 				break;
1324 			case ACPI_VIDEO_DISPLAY_LCD:
1325 				if (!video_device->flags.lcd)
1326 					continue;
1327 				break;
1328 			}
1329 		} else if (video_device->device_id != device_id) {
1330 			continue;
1331 		}
1332 
1333 		status = acpi_video_device_EDID(video_device, &buffer, length);
1334 
1335 		if (ACPI_FAILURE(status) || !buffer ||
1336 		    buffer->type != ACPI_TYPE_BUFFER) {
1337 			length = 128;
1338 			status = acpi_video_device_EDID(video_device, &buffer,
1339 							length);
1340 			if (ACPI_FAILURE(status) || !buffer ||
1341 			    buffer->type != ACPI_TYPE_BUFFER) {
1342 				continue;
1343 			}
1344 		}
1345 
1346 		*edid = buffer->buffer.pointer;
1347 		return length;
1348 	}
1349 
1350 	return -ENODEV;
1351 }
1352 EXPORT_SYMBOL(acpi_video_get_edid);
1353 
1354 static int
1355 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1356 			   struct acpi_device *device)
1357 {
1358 	int status = 0;
1359 	struct acpi_device *dev;
1360 
1361 	/*
1362 	 * There are systems where video module known to work fine regardless
1363 	 * of broken _DOD and ignoring returned value here doesn't cause
1364 	 * any issues later.
1365 	 */
1366 	acpi_video_device_enumerate(video);
1367 
1368 	list_for_each_entry(dev, &device->children, node) {
1369 
1370 		status = acpi_video_bus_get_one_device(dev, video);
1371 		if (status) {
1372 			dev_err(&dev->dev, "Can't attach device\n");
1373 			break;
1374 		}
1375 		video->child_count++;
1376 	}
1377 	return status;
1378 }
1379 
1380 /* acpi_video interface */
1381 
1382 /*
1383  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1384  * preform any automatic brightness change on receiving a notification.
1385  */
1386 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1387 {
1388 	return acpi_video_bus_DOS(video, 0,
1389 				  acpi_osi_is_win8() ? 1 : 0);
1390 }
1391 
1392 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1393 {
1394 	return acpi_video_bus_DOS(video, 0,
1395 				  acpi_osi_is_win8() ? 0 : 1);
1396 }
1397 
1398 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1399 {
1400 	struct acpi_video_bus *video = acpi_driver_data(device);
1401 	struct input_dev *input;
1402 	int keycode = 0;
1403 
1404 	if (!video || !video->input)
1405 		return;
1406 
1407 	input = video->input;
1408 
1409 	switch (event) {
1410 	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User requested a switch,
1411 					 * most likely via hotkey. */
1412 		keycode = KEY_SWITCHVIDEOMODE;
1413 		break;
1414 
1415 	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plugged in or removed a video
1416 					 * connector. */
1417 		acpi_video_device_enumerate(video);
1418 		acpi_video_device_rebind(video);
1419 		keycode = KEY_SWITCHVIDEOMODE;
1420 		break;
1421 
1422 	case ACPI_VIDEO_NOTIFY_CYCLE:	/* Cycle Display output hotkey pressed. */
1423 		keycode = KEY_SWITCHVIDEOMODE;
1424 		break;
1425 	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:	/* Next Display output hotkey pressed. */
1426 		keycode = KEY_VIDEO_NEXT;
1427 		break;
1428 	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:	/* previous Display output hotkey pressed. */
1429 		keycode = KEY_VIDEO_PREV;
1430 		break;
1431 
1432 	default:
1433 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1434 				  "Unsupported event [0x%x]\n", event));
1435 		break;
1436 	}
1437 
1438 	if (acpi_notifier_call_chain(device, event, 0))
1439 		/* Something vetoed the keypress. */
1440 		keycode = 0;
1441 
1442 	if (keycode) {
1443 		input_report_key(input, keycode, 1);
1444 		input_sync(input);
1445 		input_report_key(input, keycode, 0);
1446 		input_sync(input);
1447 	}
1448 
1449 	return;
1450 }
1451 
1452 static void brightness_switch_event(struct acpi_video_device *video_device,
1453 				    u32 event)
1454 {
1455 	if (!brightness_switch_enabled)
1456 		return;
1457 
1458 	video_device->switch_brightness_event = event;
1459 	schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1460 }
1461 
1462 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1463 {
1464 	struct acpi_video_device *video_device = data;
1465 	struct acpi_device *device = NULL;
1466 	struct acpi_video_bus *bus;
1467 	struct input_dev *input;
1468 	int keycode = 0;
1469 
1470 	if (!video_device)
1471 		return;
1472 
1473 	device = video_device->dev;
1474 	bus = video_device->video;
1475 	input = bus->input;
1476 
1477 	switch (event) {
1478 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:	/* Cycle brightness */
1479 		brightness_switch_event(video_device, event);
1480 		keycode = KEY_BRIGHTNESS_CYCLE;
1481 		break;
1482 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:	/* Increase brightness */
1483 		brightness_switch_event(video_device, event);
1484 		keycode = KEY_BRIGHTNESSUP;
1485 		break;
1486 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:	/* Decrease brightness */
1487 		brightness_switch_event(video_device, event);
1488 		keycode = KEY_BRIGHTNESSDOWN;
1489 		break;
1490 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightness */
1491 		brightness_switch_event(video_device, event);
1492 		keycode = KEY_BRIGHTNESS_ZERO;
1493 		break;
1494 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:	/* display device off */
1495 		brightness_switch_event(video_device, event);
1496 		keycode = KEY_DISPLAY_OFF;
1497 		break;
1498 	default:
1499 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1500 				  "Unsupported event [0x%x]\n", event));
1501 		break;
1502 	}
1503 
1504 	acpi_notifier_call_chain(device, event, 0);
1505 
1506 	if (keycode) {
1507 		input_report_key(input, keycode, 1);
1508 		input_sync(input);
1509 		input_report_key(input, keycode, 0);
1510 		input_sync(input);
1511 	}
1512 
1513 	return;
1514 }
1515 
1516 static int acpi_video_resume(struct notifier_block *nb,
1517 				unsigned long val, void *ign)
1518 {
1519 	struct acpi_video_bus *video;
1520 	struct acpi_video_device *video_device;
1521 	int i;
1522 
1523 	switch (val) {
1524 	case PM_HIBERNATION_PREPARE:
1525 	case PM_SUSPEND_PREPARE:
1526 	case PM_RESTORE_PREPARE:
1527 		return NOTIFY_DONE;
1528 	}
1529 
1530 	video = container_of(nb, struct acpi_video_bus, pm_nb);
1531 
1532 	dev_info(&video->device->dev, "Restoring backlight state\n");
1533 
1534 	for (i = 0; i < video->attached_count; i++) {
1535 		video_device = video->attached_array[i].bind_info;
1536 		if (video_device && video_device->brightness)
1537 			acpi_video_device_lcd_set_level(video_device,
1538 					video_device->brightness->curr);
1539 	}
1540 
1541 	return NOTIFY_OK;
1542 }
1543 
1544 static acpi_status
1545 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1546 			void **return_value)
1547 {
1548 	struct acpi_device *device = context;
1549 	struct acpi_device *sibling;
1550 	int result;
1551 
1552 	if (handle == device->handle)
1553 		return AE_CTRL_TERMINATE;
1554 
1555 	result = acpi_bus_get_device(handle, &sibling);
1556 	if (result)
1557 		return AE_OK;
1558 
1559 	if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1560 			return AE_ALREADY_EXISTS;
1561 
1562 	return AE_OK;
1563 }
1564 
1565 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1566 {
1567 	struct backlight_properties props;
1568 	struct pci_dev *pdev;
1569 	acpi_handle acpi_parent;
1570 	struct device *parent = NULL;
1571 	int result;
1572 	static int count;
1573 	char *name;
1574 
1575 	/*
1576 	 * Do not create backlight device for video output
1577 	 * device that is not in the enumerated list.
1578 	 */
1579 	if (!acpi_video_device_in_dod(device)) {
1580 		dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n");
1581 		return;
1582 	}
1583 
1584 	result = acpi_video_init_brightness(device);
1585 	if (result)
1586 		return;
1587 
1588 	if (disable_backlight_sysfs_if > 0)
1589 		return;
1590 
1591 	name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1592 	if (!name)
1593 		return;
1594 	count++;
1595 
1596 	acpi_get_parent(device->dev->handle, &acpi_parent);
1597 
1598 	pdev = acpi_get_pci_dev(acpi_parent);
1599 	if (pdev) {
1600 		parent = &pdev->dev;
1601 		pci_dev_put(pdev);
1602 	}
1603 
1604 	memset(&props, 0, sizeof(struct backlight_properties));
1605 	props.type = BACKLIGHT_FIRMWARE;
1606 	props.max_brightness = device->brightness->count - 3;
1607 	device->backlight = backlight_device_register(name,
1608 						      parent,
1609 						      device,
1610 						      &acpi_backlight_ops,
1611 						      &props);
1612 	kfree(name);
1613 	if (IS_ERR(device->backlight)) {
1614 		device->backlight = NULL;
1615 		return;
1616 	}
1617 
1618 	/*
1619 	 * Save current brightness level in case we have to restore it
1620 	 * before acpi_video_device_lcd_set_level() is called next time.
1621 	 */
1622 	device->backlight->props.brightness =
1623 			acpi_video_get_brightness(device->backlight);
1624 
1625 	device->cooling_dev = thermal_cooling_device_register("LCD",
1626 				device->dev, &video_cooling_ops);
1627 	if (IS_ERR(device->cooling_dev)) {
1628 		/*
1629 		 * Set cooling_dev to NULL so we don't crash trying to free it.
1630 		 * Also, why the hell we are returning early and not attempt to
1631 		 * register video output if cooling device registration failed?
1632 		 * -- dtor
1633 		 */
1634 		device->cooling_dev = NULL;
1635 		return;
1636 	}
1637 
1638 	dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1639 		 device->cooling_dev->id);
1640 	result = sysfs_create_link(&device->dev->dev.kobj,
1641 			&device->cooling_dev->device.kobj,
1642 			"thermal_cooling");
1643 	if (result)
1644 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1645 	result = sysfs_create_link(&device->cooling_dev->device.kobj,
1646 			&device->dev->dev.kobj, "device");
1647 	if (result)
1648 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1649 }
1650 
1651 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1652 {
1653 	struct acpi_video_device *dev;
1654 	union acpi_object *levels;
1655 
1656 	mutex_lock(&video->device_list_lock);
1657 	list_for_each_entry(dev, &video->video_device_list, entry) {
1658 		if (!acpi_video_device_lcd_query_levels(dev, &levels))
1659 			kfree(levels);
1660 	}
1661 	mutex_unlock(&video->device_list_lock);
1662 }
1663 
1664 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1665 {
1666 	struct acpi_video_device *dev;
1667 
1668 	if (video->backlight_registered)
1669 		return 0;
1670 
1671 	acpi_video_run_bcl_for_osi(video);
1672 
1673 	if (acpi_video_get_backlight_type() != acpi_backlight_video)
1674 		return 0;
1675 
1676 	mutex_lock(&video->device_list_lock);
1677 	list_for_each_entry(dev, &video->video_device_list, entry)
1678 		acpi_video_dev_register_backlight(dev);
1679 	mutex_unlock(&video->device_list_lock);
1680 
1681 	video->backlight_registered = true;
1682 
1683 	video->pm_nb.notifier_call = acpi_video_resume;
1684 	video->pm_nb.priority = 0;
1685 	return register_pm_notifier(&video->pm_nb);
1686 }
1687 
1688 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1689 {
1690 	if (device->backlight) {
1691 		backlight_device_unregister(device->backlight);
1692 		device->backlight = NULL;
1693 	}
1694 	if (device->brightness) {
1695 		kfree(device->brightness->levels);
1696 		kfree(device->brightness);
1697 		device->brightness = NULL;
1698 	}
1699 	if (device->cooling_dev) {
1700 		sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1701 		sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1702 		thermal_cooling_device_unregister(device->cooling_dev);
1703 		device->cooling_dev = NULL;
1704 	}
1705 }
1706 
1707 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1708 {
1709 	struct acpi_video_device *dev;
1710 	int error;
1711 
1712 	if (!video->backlight_registered)
1713 		return 0;
1714 
1715 	error = unregister_pm_notifier(&video->pm_nb);
1716 
1717 	mutex_lock(&video->device_list_lock);
1718 	list_for_each_entry(dev, &video->video_device_list, entry)
1719 		acpi_video_dev_unregister_backlight(dev);
1720 	mutex_unlock(&video->device_list_lock);
1721 
1722 	video->backlight_registered = false;
1723 
1724 	return error;
1725 }
1726 
1727 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1728 {
1729 	acpi_status status;
1730 	struct acpi_device *adev = device->dev;
1731 
1732 	status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1733 					     acpi_video_device_notify, device);
1734 	if (ACPI_FAILURE(status))
1735 		dev_err(&adev->dev, "Error installing notify handler\n");
1736 	else
1737 		device->flags.notify = 1;
1738 }
1739 
1740 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1741 {
1742 	struct input_dev *input;
1743 	struct acpi_video_device *dev;
1744 	int error;
1745 
1746 	video->input = input = input_allocate_device();
1747 	if (!input) {
1748 		error = -ENOMEM;
1749 		goto out;
1750 	}
1751 
1752 	error = acpi_video_bus_start_devices(video);
1753 	if (error)
1754 		goto err_free_input;
1755 
1756 	snprintf(video->phys, sizeof(video->phys),
1757 			"%s/video/input0", acpi_device_hid(video->device));
1758 
1759 	input->name = acpi_device_name(video->device);
1760 	input->phys = video->phys;
1761 	input->id.bustype = BUS_HOST;
1762 	input->id.product = 0x06;
1763 	input->dev.parent = &video->device->dev;
1764 	input->evbit[0] = BIT(EV_KEY);
1765 	set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1766 	set_bit(KEY_VIDEO_NEXT, input->keybit);
1767 	set_bit(KEY_VIDEO_PREV, input->keybit);
1768 	set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1769 	set_bit(KEY_BRIGHTNESSUP, input->keybit);
1770 	set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1771 	set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1772 	set_bit(KEY_DISPLAY_OFF, input->keybit);
1773 
1774 	error = input_register_device(input);
1775 	if (error)
1776 		goto err_stop_dev;
1777 
1778 	mutex_lock(&video->device_list_lock);
1779 	list_for_each_entry(dev, &video->video_device_list, entry)
1780 		acpi_video_dev_add_notify_handler(dev);
1781 	mutex_unlock(&video->device_list_lock);
1782 
1783 	return 0;
1784 
1785 err_stop_dev:
1786 	acpi_video_bus_stop_devices(video);
1787 err_free_input:
1788 	input_free_device(input);
1789 	video->input = NULL;
1790 out:
1791 	return error;
1792 }
1793 
1794 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1795 {
1796 	if (dev->flags.notify) {
1797 		acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1798 					   acpi_video_device_notify);
1799 		dev->flags.notify = 0;
1800 	}
1801 }
1802 
1803 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1804 {
1805 	struct acpi_video_device *dev;
1806 
1807 	mutex_lock(&video->device_list_lock);
1808 	list_for_each_entry(dev, &video->video_device_list, entry)
1809 		acpi_video_dev_remove_notify_handler(dev);
1810 	mutex_unlock(&video->device_list_lock);
1811 
1812 	acpi_video_bus_stop_devices(video);
1813 	input_unregister_device(video->input);
1814 	video->input = NULL;
1815 }
1816 
1817 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1818 {
1819 	struct acpi_video_device *dev, *next;
1820 
1821 	mutex_lock(&video->device_list_lock);
1822 	list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1823 		list_del(&dev->entry);
1824 		kfree(dev);
1825 	}
1826 	mutex_unlock(&video->device_list_lock);
1827 
1828 	return 0;
1829 }
1830 
1831 static int instance;
1832 
1833 static int acpi_video_bus_add(struct acpi_device *device)
1834 {
1835 	struct acpi_video_bus *video;
1836 	int error;
1837 	acpi_status status;
1838 
1839 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1840 				device->parent->handle, 1,
1841 				acpi_video_bus_match, NULL,
1842 				device, NULL);
1843 	if (status == AE_ALREADY_EXISTS) {
1844 		printk(KERN_WARNING FW_BUG
1845 			"Duplicate ACPI video bus devices for the"
1846 			" same VGA controller, please try module "
1847 			"parameter \"video.allow_duplicates=1\""
1848 			"if the current driver doesn't work.\n");
1849 		if (!allow_duplicates)
1850 			return -ENODEV;
1851 	}
1852 
1853 	video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1854 	if (!video)
1855 		return -ENOMEM;
1856 
1857 	/* a hack to fix the duplicate name "VID" problem on T61 */
1858 	if (!strcmp(device->pnp.bus_id, "VID")) {
1859 		if (instance)
1860 			device->pnp.bus_id[3] = '0' + instance;
1861 		instance++;
1862 	}
1863 	/* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1864 	if (!strcmp(device->pnp.bus_id, "VGA")) {
1865 		if (instance)
1866 			device->pnp.bus_id[3] = '0' + instance;
1867 		instance++;
1868 	}
1869 
1870 	video->device = device;
1871 	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1872 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1873 	device->driver_data = video;
1874 
1875 	acpi_video_bus_find_cap(video);
1876 	error = acpi_video_bus_check(video);
1877 	if (error)
1878 		goto err_free_video;
1879 
1880 	mutex_init(&video->device_list_lock);
1881 	INIT_LIST_HEAD(&video->video_device_list);
1882 
1883 	error = acpi_video_bus_get_devices(video, device);
1884 	if (error)
1885 		goto err_put_video;
1886 
1887 	printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1888 	       ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1889 	       video->flags.multihead ? "yes" : "no",
1890 	       video->flags.rom ? "yes" : "no",
1891 	       video->flags.post ? "yes" : "no");
1892 	mutex_lock(&video_list_lock);
1893 	list_add_tail(&video->entry, &video_bus_head);
1894 	mutex_unlock(&video_list_lock);
1895 
1896 	acpi_video_bus_register_backlight(video);
1897 	acpi_video_bus_add_notify_handler(video);
1898 
1899 	return 0;
1900 
1901 err_put_video:
1902 	acpi_video_bus_put_devices(video);
1903 	kfree(video->attached_array);
1904 err_free_video:
1905 	kfree(video);
1906 	device->driver_data = NULL;
1907 
1908 	return error;
1909 }
1910 
1911 static int acpi_video_bus_remove(struct acpi_device *device)
1912 {
1913 	struct acpi_video_bus *video = NULL;
1914 
1915 
1916 	if (!device || !acpi_driver_data(device))
1917 		return -EINVAL;
1918 
1919 	video = acpi_driver_data(device);
1920 
1921 	acpi_video_bus_remove_notify_handler(video);
1922 	acpi_video_bus_unregister_backlight(video);
1923 	acpi_video_bus_put_devices(video);
1924 
1925 	mutex_lock(&video_list_lock);
1926 	list_del(&video->entry);
1927 	mutex_unlock(&video_list_lock);
1928 
1929 	kfree(video->attached_array);
1930 	kfree(video);
1931 
1932 	return 0;
1933 }
1934 
1935 static int __init is_i740(struct pci_dev *dev)
1936 {
1937 	if (dev->device == 0x00D1)
1938 		return 1;
1939 	if (dev->device == 0x7000)
1940 		return 1;
1941 	return 0;
1942 }
1943 
1944 static int __init intel_opregion_present(void)
1945 {
1946 	int opregion = 0;
1947 	struct pci_dev *dev = NULL;
1948 	u32 address;
1949 
1950 	for_each_pci_dev(dev) {
1951 		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
1952 			continue;
1953 		if (dev->vendor != PCI_VENDOR_ID_INTEL)
1954 			continue;
1955 		/* We don't want to poke around undefined i740 registers */
1956 		if (is_i740(dev))
1957 			continue;
1958 		pci_read_config_dword(dev, 0xfc, &address);
1959 		if (!address)
1960 			continue;
1961 		opregion = 1;
1962 	}
1963 	return opregion;
1964 }
1965 
1966 int acpi_video_register(void)
1967 {
1968 	int ret = 0;
1969 
1970 	mutex_lock(&register_count_mutex);
1971 	if (register_count) {
1972 		/*
1973 		 * if the function of acpi_video_register is already called,
1974 		 * don't register the acpi_vide_bus again and return no error.
1975 		 */
1976 		goto leave;
1977 	}
1978 
1979 	mutex_init(&video_list_lock);
1980 	INIT_LIST_HEAD(&video_bus_head);
1981 
1982 	dmi_check_system(video_dmi_table);
1983 
1984 	ret = acpi_bus_register_driver(&acpi_video_bus);
1985 	if (ret)
1986 		goto leave;
1987 
1988 	/*
1989 	 * When the acpi_video_bus is loaded successfully, increase
1990 	 * the counter reference.
1991 	 */
1992 	register_count = 1;
1993 
1994 leave:
1995 	mutex_unlock(&register_count_mutex);
1996 	return ret;
1997 }
1998 EXPORT_SYMBOL(acpi_video_register);
1999 
2000 void acpi_video_unregister(void)
2001 {
2002 	mutex_lock(&register_count_mutex);
2003 	if (register_count) {
2004 		acpi_bus_unregister_driver(&acpi_video_bus);
2005 		register_count = 0;
2006 	}
2007 	mutex_unlock(&register_count_mutex);
2008 }
2009 EXPORT_SYMBOL(acpi_video_unregister);
2010 
2011 void acpi_video_unregister_backlight(void)
2012 {
2013 	struct acpi_video_bus *video;
2014 
2015 	mutex_lock(&register_count_mutex);
2016 	if (register_count) {
2017 		mutex_lock(&video_list_lock);
2018 		list_for_each_entry(video, &video_bus_head, entry)
2019 			acpi_video_bus_unregister_backlight(video);
2020 		mutex_unlock(&video_list_lock);
2021 	}
2022 	mutex_unlock(&register_count_mutex);
2023 }
2024 
2025 /*
2026  * This is kind of nasty. Hardware using Intel chipsets may require
2027  * the video opregion code to be run first in order to initialise
2028  * state before any ACPI video calls are made. To handle this we defer
2029  * registration of the video class until the opregion code has run.
2030  */
2031 
2032 static int __init acpi_video_init(void)
2033 {
2034 	/*
2035 	 * Let the module load even if ACPI is disabled (e.g. due to
2036 	 * a broken BIOS) so that i915.ko can still be loaded on such
2037 	 * old systems without an AcpiOpRegion.
2038 	 *
2039 	 * acpi_video_register() will report -ENODEV later as well due
2040 	 * to acpi_disabled when i915.ko tries to register itself afterwards.
2041 	 */
2042 	if (acpi_disabled)
2043 		return 0;
2044 
2045 	if (intel_opregion_present())
2046 		return 0;
2047 
2048 	return acpi_video_register();
2049 }
2050 
2051 static void __exit acpi_video_exit(void)
2052 {
2053 	acpi_video_detect_exit();
2054 	acpi_video_unregister();
2055 
2056 	return;
2057 }
2058 
2059 module_init(acpi_video_init);
2060 module_exit(acpi_video_exit);
2061