xref: /linux/drivers/acpi/acpi_video.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
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 static int register_count;
81 static DEFINE_MUTEX(register_count_mutex);
82 static struct mutex video_list_lock;
83 static struct list_head video_bus_head;
84 static int acpi_video_bus_add(struct acpi_device *device);
85 static int acpi_video_bus_remove(struct acpi_device *device);
86 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
87 void acpi_video_detect_exit(void);
88 
89 static const struct acpi_device_id video_device_ids[] = {
90 	{ACPI_VIDEO_HID, 0},
91 	{"", 0},
92 };
93 MODULE_DEVICE_TABLE(acpi, video_device_ids);
94 
95 static struct acpi_driver acpi_video_bus = {
96 	.name = "video",
97 	.class = ACPI_VIDEO_CLASS,
98 	.ids = video_device_ids,
99 	.ops = {
100 		.add = acpi_video_bus_add,
101 		.remove = acpi_video_bus_remove,
102 		.notify = acpi_video_bus_notify,
103 		},
104 };
105 
106 struct acpi_video_bus_flags {
107 	u8 multihead:1;		/* can switch video heads */
108 	u8 rom:1;		/* can retrieve a video rom */
109 	u8 post:1;		/* can configure the head to */
110 	u8 reserved:5;
111 };
112 
113 struct acpi_video_bus_cap {
114 	u8 _DOS:1;		/* Enable/Disable output switching */
115 	u8 _DOD:1;		/* Enumerate all devices attached to display adapter */
116 	u8 _ROM:1;		/* Get ROM Data */
117 	u8 _GPD:1;		/* Get POST Device */
118 	u8 _SPD:1;		/* Set POST Device */
119 	u8 _VPO:1;		/* Video POST Options */
120 	u8 reserved:2;
121 };
122 
123 struct acpi_video_device_attrib {
124 	u32 display_index:4;	/* A zero-based instance of the Display */
125 	u32 display_port_attachment:4;	/* This field differentiates the display type */
126 	u32 display_type:4;	/* Describe the specific type in use */
127 	u32 vendor_specific:4;	/* Chipset Vendor Specific */
128 	u32 bios_can_detect:1;	/* BIOS can detect the device */
129 	u32 depend_on_vga:1;	/* Non-VGA output device whose power is related to
130 				   the VGA device. */
131 	u32 pipe_id:3;		/* For VGA multiple-head devices. */
132 	u32 reserved:10;	/* Must be 0 */
133 	u32 device_id_scheme:1;	/* Device ID Scheme */
134 };
135 
136 struct acpi_video_enumerated_device {
137 	union {
138 		u32 int_val;
139 		struct acpi_video_device_attrib attrib;
140 	} value;
141 	struct acpi_video_device *bind_info;
142 };
143 
144 struct acpi_video_bus {
145 	struct acpi_device *device;
146 	bool backlight_registered;
147 	u8 dos_setting;
148 	struct acpi_video_enumerated_device *attached_array;
149 	u8 attached_count;
150 	u8 child_count;
151 	struct acpi_video_bus_cap cap;
152 	struct acpi_video_bus_flags flags;
153 	struct list_head video_device_list;
154 	struct mutex device_list_lock;	/* protects video_device_list */
155 	struct list_head entry;
156 	struct input_dev *input;
157 	char phys[32];	/* for input device */
158 	struct notifier_block pm_nb;
159 };
160 
161 struct acpi_video_device_flags {
162 	u8 crt:1;
163 	u8 lcd:1;
164 	u8 tvout:1;
165 	u8 dvi:1;
166 	u8 bios:1;
167 	u8 unknown:1;
168 	u8 notify:1;
169 	u8 reserved:1;
170 };
171 
172 struct acpi_video_device_cap {
173 	u8 _ADR:1;		/* Return the unique ID */
174 	u8 _BCL:1;		/* Query list of brightness control levels supported */
175 	u8 _BCM:1;		/* Set the brightness level */
176 	u8 _BQC:1;		/* Get current brightness level */
177 	u8 _BCQ:1;		/* Some buggy BIOS uses _BCQ instead of _BQC */
178 	u8 _DDC:1;		/* Return the EDID for this device */
179 };
180 
181 struct acpi_video_brightness_flags {
182 	u8 _BCL_no_ac_battery_levels:1;	/* no AC/Battery levels in _BCL */
183 	u8 _BCL_reversed:1;		/* _BCL package is in a reversed order */
184 	u8 _BQC_use_index:1;		/* _BQC returns an index value */
185 };
186 
187 struct acpi_video_device_brightness {
188 	int curr;
189 	int count;
190 	int *levels;
191 	struct acpi_video_brightness_flags flags;
192 };
193 
194 struct acpi_video_device {
195 	unsigned long device_id;
196 	struct acpi_video_device_flags flags;
197 	struct acpi_video_device_cap cap;
198 	struct list_head entry;
199 	struct delayed_work switch_brightness_work;
200 	int switch_brightness_event;
201 	struct acpi_video_bus *video;
202 	struct acpi_device *dev;
203 	struct acpi_video_device_brightness *brightness;
204 	struct backlight_device *backlight;
205 	struct thermal_cooling_device *cooling_dev;
206 };
207 
208 static const char device_decode[][30] = {
209 	"motherboard VGA device",
210 	"PCI VGA device",
211 	"AGP VGA device",
212 	"UNKNOWN",
213 };
214 
215 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
216 static void acpi_video_device_rebind(struct acpi_video_bus *video);
217 static void acpi_video_device_bind(struct acpi_video_bus *video,
218 				   struct acpi_video_device *device);
219 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
220 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
221 			int level);
222 static int acpi_video_device_lcd_get_level_current(
223 			struct acpi_video_device *device,
224 			unsigned long long *level, bool raw);
225 static int acpi_video_get_next_level(struct acpi_video_device *device,
226 				     u32 level_current, u32 event);
227 static void acpi_video_switch_brightness(struct work_struct *work);
228 
229 /* backlight device sysfs support */
230 static int acpi_video_get_brightness(struct backlight_device *bd)
231 {
232 	unsigned long long cur_level;
233 	int i;
234 	struct acpi_video_device *vd = bl_get_data(bd);
235 
236 	if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
237 		return -EINVAL;
238 	for (i = 2; i < vd->brightness->count; i++) {
239 		if (vd->brightness->levels[i] == cur_level)
240 			/*
241 			 * The first two entries are special - see page 575
242 			 * of the ACPI spec 3.0
243 			 */
244 			return i - 2;
245 	}
246 	return 0;
247 }
248 
249 static int acpi_video_set_brightness(struct backlight_device *bd)
250 {
251 	int request_level = bd->props.brightness + 2;
252 	struct acpi_video_device *vd = bl_get_data(bd);
253 
254 	cancel_delayed_work(&vd->switch_brightness_work);
255 	return acpi_video_device_lcd_set_level(vd,
256 				vd->brightness->levels[request_level]);
257 }
258 
259 static const struct backlight_ops acpi_backlight_ops = {
260 	.get_brightness = acpi_video_get_brightness,
261 	.update_status  = acpi_video_set_brightness,
262 };
263 
264 /* thermal cooling device callbacks */
265 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
266 			       long *state)
267 {
268 	struct acpi_device *device = cooling_dev->devdata;
269 	struct acpi_video_device *video = acpi_driver_data(device);
270 
271 	*state = video->brightness->count - 3;
272 	return 0;
273 }
274 
275 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
276 			       long *state)
277 {
278 	struct acpi_device *device = cooling_dev->devdata;
279 	struct acpi_video_device *video = acpi_driver_data(device);
280 	unsigned long long level;
281 	int offset;
282 
283 	if (acpi_video_device_lcd_get_level_current(video, &level, false))
284 		return -EINVAL;
285 	for (offset = 2; offset < video->brightness->count; offset++)
286 		if (level == video->brightness->levels[offset]) {
287 			*state = video->brightness->count - offset - 1;
288 			return 0;
289 		}
290 
291 	return -EINVAL;
292 }
293 
294 static int
295 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
296 {
297 	struct acpi_device *device = cooling_dev->devdata;
298 	struct acpi_video_device *video = acpi_driver_data(device);
299 	int level;
300 
301 	if (state >= video->brightness->count - 2)
302 		return -EINVAL;
303 
304 	state = video->brightness->count - state;
305 	level = video->brightness->levels[state - 1];
306 	return acpi_video_device_lcd_set_level(video, level);
307 }
308 
309 static const struct thermal_cooling_device_ops video_cooling_ops = {
310 	.get_max_state = video_get_max_state,
311 	.get_cur_state = video_get_cur_state,
312 	.set_cur_state = video_set_cur_state,
313 };
314 
315 /*
316  * --------------------------------------------------------------------------
317  *                             Video Management
318  * --------------------------------------------------------------------------
319  */
320 
321 static int
322 acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
323 				   union acpi_object **levels)
324 {
325 	int status;
326 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
327 	union acpi_object *obj;
328 
329 
330 	*levels = NULL;
331 
332 	status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
333 	if (!ACPI_SUCCESS(status))
334 		return status;
335 	obj = (union acpi_object *)buffer.pointer;
336 	if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
337 		printk(KERN_ERR PREFIX "Invalid _BCL data\n");
338 		status = -EFAULT;
339 		goto err;
340 	}
341 
342 	*levels = obj;
343 
344 	return 0;
345 
346 err:
347 	kfree(buffer.pointer);
348 
349 	return status;
350 }
351 
352 static int
353 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
354 {
355 	int status;
356 	int state;
357 
358 	status = acpi_execute_simple_method(device->dev->handle,
359 					    "_BCM", level);
360 	if (ACPI_FAILURE(status)) {
361 		ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
362 		return -EIO;
363 	}
364 
365 	device->brightness->curr = level;
366 	for (state = 2; state < device->brightness->count; state++)
367 		if (level == device->brightness->levels[state]) {
368 			if (device->backlight)
369 				device->backlight->props.brightness = state - 2;
370 			return 0;
371 		}
372 
373 	ACPI_ERROR((AE_INFO, "Current brightness invalid"));
374 	return -EINVAL;
375 }
376 
377 /*
378  * For some buggy _BQC methods, we need to add a constant value to
379  * the _BQC return value to get the actual current brightness level
380  */
381 
382 static int bqc_offset_aml_bug_workaround;
383 static int video_set_bqc_offset(const struct dmi_system_id *d)
384 {
385 	bqc_offset_aml_bug_workaround = 9;
386 	return 0;
387 }
388 
389 static int video_disable_backlight_sysfs_if(
390 	const struct dmi_system_id *d)
391 {
392 	if (disable_backlight_sysfs_if == -1)
393 		disable_backlight_sysfs_if = 1;
394 	return 0;
395 }
396 
397 static struct dmi_system_id video_dmi_table[] = {
398 	/*
399 	 * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
400 	 */
401 	{
402 	 .callback = video_set_bqc_offset,
403 	 .ident = "Acer Aspire 5720",
404 	 .matches = {
405 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
406 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
407 		},
408 	},
409 	{
410 	 .callback = video_set_bqc_offset,
411 	 .ident = "Acer Aspire 5710Z",
412 	 .matches = {
413 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
414 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
415 		},
416 	},
417 	{
418 	 .callback = video_set_bqc_offset,
419 	 .ident = "eMachines E510",
420 	 .matches = {
421 		DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
422 		DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
423 		},
424 	},
425 	{
426 	 .callback = video_set_bqc_offset,
427 	 .ident = "Acer Aspire 5315",
428 	 .matches = {
429 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
430 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
431 		},
432 	},
433 	{
434 	 .callback = video_set_bqc_offset,
435 	 .ident = "Acer Aspire 7720",
436 	 .matches = {
437 		DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
438 		DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
439 		},
440 	},
441 
442 	/*
443 	 * Some machines have a broken acpi-video interface for brightness
444 	 * control, but still need an acpi_video_device_lcd_set_level() call
445 	 * on resume to turn the backlight power on.  We Enable backlight
446 	 * control on these systems, but do not register a backlight sysfs
447 	 * as brightness control does not work.
448 	 */
449 	{
450 	 /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
451 	 .callback = video_disable_backlight_sysfs_if,
452 	 .ident = "Toshiba Portege R830",
453 	 .matches = {
454 		DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
455 		DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
456 		},
457 	},
458 	{}
459 };
460 
461 static unsigned long long
462 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
463 			      unsigned long long bqc_value)
464 {
465 	unsigned long long level;
466 
467 	if (device->brightness->flags._BQC_use_index) {
468 		/*
469 		 * _BQC returns an index that doesn't account for
470 		 * the first 2 items with special meaning, so we need
471 		 * to compensate for that by offsetting ourselves
472 		 */
473 		if (device->brightness->flags._BCL_reversed)
474 			bqc_value = device->brightness->count - 3 - bqc_value;
475 
476 		level = device->brightness->levels[bqc_value + 2];
477 	} else {
478 		level = bqc_value;
479 	}
480 
481 	level += bqc_offset_aml_bug_workaround;
482 
483 	return level;
484 }
485 
486 static int
487 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
488 					unsigned long long *level, bool raw)
489 {
490 	acpi_status status = AE_OK;
491 	int i;
492 
493 	if (device->cap._BQC || device->cap._BCQ) {
494 		char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
495 
496 		status = acpi_evaluate_integer(device->dev->handle, buf,
497 						NULL, level);
498 		if (ACPI_SUCCESS(status)) {
499 			if (raw) {
500 				/*
501 				 * Caller has indicated he wants the raw
502 				 * value returned by _BQC, so don't furtherly
503 				 * mess with the value.
504 				 */
505 				return 0;
506 			}
507 
508 			*level = acpi_video_bqc_value_to_level(device, *level);
509 
510 			for (i = 2; i < device->brightness->count; i++)
511 				if (device->brightness->levels[i] == *level) {
512 					device->brightness->curr = *level;
513 					return 0;
514 				}
515 			/*
516 			 * BQC returned an invalid level.
517 			 * Stop using it.
518 			 */
519 			ACPI_WARNING((AE_INFO,
520 				      "%s returned an invalid level",
521 				      buf));
522 			device->cap._BQC = device->cap._BCQ = 0;
523 		} else {
524 			/*
525 			 * Fixme:
526 			 * should we return an error or ignore this failure?
527 			 * dev->brightness->curr is a cached value which stores
528 			 * the correct current backlight level in most cases.
529 			 * ACPI video backlight still works w/ buggy _BQC.
530 			 * http://bugzilla.kernel.org/show_bug.cgi?id=12233
531 			 */
532 			ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
533 			device->cap._BQC = device->cap._BCQ = 0;
534 		}
535 	}
536 
537 	*level = device->brightness->curr;
538 	return 0;
539 }
540 
541 static int
542 acpi_video_device_EDID(struct acpi_video_device *device,
543 		       union acpi_object **edid, ssize_t length)
544 {
545 	int status;
546 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
547 	union acpi_object *obj;
548 	union acpi_object arg0 = { ACPI_TYPE_INTEGER };
549 	struct acpi_object_list args = { 1, &arg0 };
550 
551 
552 	*edid = NULL;
553 
554 	if (!device)
555 		return -ENODEV;
556 	if (length == 128)
557 		arg0.integer.value = 1;
558 	else if (length == 256)
559 		arg0.integer.value = 2;
560 	else
561 		return -EINVAL;
562 
563 	status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
564 	if (ACPI_FAILURE(status))
565 		return -ENODEV;
566 
567 	obj = buffer.pointer;
568 
569 	if (obj && obj->type == ACPI_TYPE_BUFFER)
570 		*edid = obj;
571 	else {
572 		printk(KERN_ERR PREFIX "Invalid _DDC data\n");
573 		status = -EFAULT;
574 		kfree(obj);
575 	}
576 
577 	return status;
578 }
579 
580 /* bus */
581 
582 /*
583  *  Arg:
584  *	video		: video bus device pointer
585  *	bios_flag	:
586  *		0.	The system BIOS should NOT automatically switch(toggle)
587  *			the active display output.
588  *		1.	The system BIOS should automatically switch (toggle) the
589  *			active display output. No switch event.
590  *		2.	The _DGS value should be locked.
591  *		3.	The system BIOS should not automatically switch (toggle) the
592  *			active display output, but instead generate the display switch
593  *			event notify code.
594  *	lcd_flag	:
595  *		0.	The system BIOS should automatically control the brightness level
596  *			of the LCD when the power changes from AC to DC
597  *		1.	The system BIOS should NOT automatically control the brightness
598  *			level of the LCD when the power changes from AC to DC.
599  *  Return Value:
600  *		-EINVAL	wrong arg.
601  */
602 
603 static int
604 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
605 {
606 	acpi_status status;
607 
608 	if (!video->cap._DOS)
609 		return 0;
610 
611 	if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
612 		return -EINVAL;
613 	video->dos_setting = (lcd_flag << 2) | bios_flag;
614 	status = acpi_execute_simple_method(video->device->handle, "_DOS",
615 					    (lcd_flag << 2) | bios_flag);
616 	if (ACPI_FAILURE(status))
617 		return -EIO;
618 
619 	return 0;
620 }
621 
622 /*
623  * Simple comparison function used to sort backlight levels.
624  */
625 
626 static int
627 acpi_video_cmp_level(const void *a, const void *b)
628 {
629 	return *(int *)a - *(int *)b;
630 }
631 
632 /*
633  * Decides if _BQC/_BCQ for this system is usable
634  *
635  * We do this by changing the level first and then read out the current
636  * brightness level, if the value does not match, find out if it is using
637  * index. If not, clear the _BQC/_BCQ capability.
638  */
639 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
640 				int max_level, int current_level)
641 {
642 	struct acpi_video_device_brightness *br = device->brightness;
643 	int result;
644 	unsigned long long level;
645 	int test_level;
646 
647 	/* don't mess with existing known broken systems */
648 	if (bqc_offset_aml_bug_workaround)
649 		return 0;
650 
651 	/*
652 	 * Some systems always report current brightness level as maximum
653 	 * through _BQC, we need to test another value for them.
654 	 */
655 	test_level = current_level == max_level ? br->levels[3] : max_level;
656 
657 	result = acpi_video_device_lcd_set_level(device, test_level);
658 	if (result)
659 		return result;
660 
661 	result = acpi_video_device_lcd_get_level_current(device, &level, true);
662 	if (result)
663 		return result;
664 
665 	if (level != test_level) {
666 		/* buggy _BQC found, need to find out if it uses index */
667 		if (level < br->count) {
668 			if (br->flags._BCL_reversed)
669 				level = br->count - 3 - level;
670 			if (br->levels[level + 2] == test_level)
671 				br->flags._BQC_use_index = 1;
672 		}
673 
674 		if (!br->flags._BQC_use_index)
675 			device->cap._BQC = device->cap._BCQ = 0;
676 	}
677 
678 	return 0;
679 }
680 
681 
682 /*
683  *  Arg:
684  *	device	: video output device (LCD, CRT, ..)
685  *
686  *  Return Value:
687  *	Maximum brightness level
688  *
689  *  Allocate and initialize device->brightness.
690  */
691 
692 static int
693 acpi_video_init_brightness(struct acpi_video_device *device)
694 {
695 	union acpi_object *obj = NULL;
696 	int i, max_level = 0, count = 0, level_ac_battery = 0;
697 	unsigned long long level, level_old;
698 	union acpi_object *o;
699 	struct acpi_video_device_brightness *br = NULL;
700 	int result = -EINVAL;
701 	u32 value;
702 
703 	if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
704 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
705 						"LCD brightness level\n"));
706 		goto out;
707 	}
708 
709 	if (obj->package.count < 2)
710 		goto out;
711 
712 	br = kzalloc(sizeof(*br), GFP_KERNEL);
713 	if (!br) {
714 		printk(KERN_ERR "can't allocate memory\n");
715 		result = -ENOMEM;
716 		goto out;
717 	}
718 
719 	br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
720 				GFP_KERNEL);
721 	if (!br->levels) {
722 		result = -ENOMEM;
723 		goto out_free;
724 	}
725 
726 	for (i = 0; i < obj->package.count; i++) {
727 		o = (union acpi_object *)&obj->package.elements[i];
728 		if (o->type != ACPI_TYPE_INTEGER) {
729 			printk(KERN_ERR PREFIX "Invalid data\n");
730 			continue;
731 		}
732 		value = (u32) o->integer.value;
733 		/* Skip duplicate entries */
734 		if (count > 2 && br->levels[count - 1] == value)
735 			continue;
736 
737 		br->levels[count] = value;
738 
739 		if (br->levels[count] > max_level)
740 			max_level = br->levels[count];
741 		count++;
742 	}
743 
744 	/*
745 	 * some buggy BIOS don't export the levels
746 	 * when machine is on AC/Battery in _BCL package.
747 	 * In this case, the first two elements in _BCL packages
748 	 * are also supported brightness levels that OS should take care of.
749 	 */
750 	for (i = 2; i < count; i++) {
751 		if (br->levels[i] == br->levels[0])
752 			level_ac_battery++;
753 		if (br->levels[i] == br->levels[1])
754 			level_ac_battery++;
755 	}
756 
757 	if (level_ac_battery < 2) {
758 		level_ac_battery = 2 - level_ac_battery;
759 		br->flags._BCL_no_ac_battery_levels = 1;
760 		for (i = (count - 1 + level_ac_battery); i >= 2; i--)
761 			br->levels[i] = br->levels[i - level_ac_battery];
762 		count += level_ac_battery;
763 	} else if (level_ac_battery > 2)
764 		ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
765 
766 	/* Check if the _BCL package is in a reversed order */
767 	if (max_level == br->levels[2]) {
768 		br->flags._BCL_reversed = 1;
769 		sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
770 			acpi_video_cmp_level, NULL);
771 	} else if (max_level != br->levels[count - 1])
772 		ACPI_ERROR((AE_INFO,
773 			    "Found unordered _BCL package"));
774 
775 	br->count = count;
776 	device->brightness = br;
777 
778 	/* _BQC uses INDEX while _BCL uses VALUE in some laptops */
779 	br->curr = level = max_level;
780 
781 	if (!device->cap._BQC)
782 		goto set_level;
783 
784 	result = acpi_video_device_lcd_get_level_current(device,
785 							 &level_old, true);
786 	if (result)
787 		goto out_free_levels;
788 
789 	result = acpi_video_bqc_quirk(device, max_level, level_old);
790 	if (result)
791 		goto out_free_levels;
792 	/*
793 	 * cap._BQC may get cleared due to _BQC is found to be broken
794 	 * in acpi_video_bqc_quirk, so check again here.
795 	 */
796 	if (!device->cap._BQC)
797 		goto set_level;
798 
799 	level = acpi_video_bqc_value_to_level(device, level_old);
800 	/*
801 	 * On some buggy laptops, _BQC returns an uninitialized
802 	 * value when invoked for the first time, i.e.
803 	 * level_old is invalid (no matter whether it's a level
804 	 * or an index). Set the backlight to max_level in this case.
805 	 */
806 	for (i = 2; i < br->count; i++)
807 		if (level == br->levels[i])
808 			break;
809 	if (i == br->count || !level)
810 		level = max_level;
811 
812 set_level:
813 	result = acpi_video_device_lcd_set_level(device, level);
814 	if (result)
815 		goto out_free_levels;
816 
817 	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
818 			  "found %d brightness levels\n", count - 2));
819 	kfree(obj);
820 	return result;
821 
822 out_free_levels:
823 	kfree(br->levels);
824 out_free:
825 	kfree(br);
826 out:
827 	device->brightness = NULL;
828 	kfree(obj);
829 	return result;
830 }
831 
832 /*
833  *  Arg:
834  *	device	: video output device (LCD, CRT, ..)
835  *
836  *  Return Value:
837  *	None
838  *
839  *  Find out all required AML methods defined under the output
840  *  device.
841  */
842 
843 static void acpi_video_device_find_cap(struct acpi_video_device *device)
844 {
845 	if (acpi_has_method(device->dev->handle, "_ADR"))
846 		device->cap._ADR = 1;
847 	if (acpi_has_method(device->dev->handle, "_BCL"))
848 		device->cap._BCL = 1;
849 	if (acpi_has_method(device->dev->handle, "_BCM"))
850 		device->cap._BCM = 1;
851 	if (acpi_has_method(device->dev->handle, "_BQC")) {
852 		device->cap._BQC = 1;
853 	} else if (acpi_has_method(device->dev->handle, "_BCQ")) {
854 		printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
855 		device->cap._BCQ = 1;
856 	}
857 
858 	if (acpi_has_method(device->dev->handle, "_DDC"))
859 		device->cap._DDC = 1;
860 }
861 
862 /*
863  *  Arg:
864  *	device	: video output device (VGA)
865  *
866  *  Return Value:
867  *	None
868  *
869  *  Find out all required AML methods defined under the video bus device.
870  */
871 
872 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
873 {
874 	if (acpi_has_method(video->device->handle, "_DOS"))
875 		video->cap._DOS = 1;
876 	if (acpi_has_method(video->device->handle, "_DOD"))
877 		video->cap._DOD = 1;
878 	if (acpi_has_method(video->device->handle, "_ROM"))
879 		video->cap._ROM = 1;
880 	if (acpi_has_method(video->device->handle, "_GPD"))
881 		video->cap._GPD = 1;
882 	if (acpi_has_method(video->device->handle, "_SPD"))
883 		video->cap._SPD = 1;
884 	if (acpi_has_method(video->device->handle, "_VPO"))
885 		video->cap._VPO = 1;
886 }
887 
888 /*
889  * Check whether the video bus device has required AML method to
890  * support the desired features
891  */
892 
893 static int acpi_video_bus_check(struct acpi_video_bus *video)
894 {
895 	acpi_status status = -ENOENT;
896 	struct pci_dev *dev;
897 
898 	if (!video)
899 		return -EINVAL;
900 
901 	dev = acpi_get_pci_dev(video->device->handle);
902 	if (!dev)
903 		return -ENODEV;
904 	pci_dev_put(dev);
905 
906 	/*
907 	 * Since there is no HID, CID and so on for VGA driver, we have
908 	 * to check well known required nodes.
909 	 */
910 
911 	/* Does this device support video switching? */
912 	if (video->cap._DOS || video->cap._DOD) {
913 		if (!video->cap._DOS) {
914 			printk(KERN_WARNING FW_BUG
915 				"ACPI(%s) defines _DOD but not _DOS\n",
916 				acpi_device_bid(video->device));
917 		}
918 		video->flags.multihead = 1;
919 		status = 0;
920 	}
921 
922 	/* Does this device support retrieving a video ROM? */
923 	if (video->cap._ROM) {
924 		video->flags.rom = 1;
925 		status = 0;
926 	}
927 
928 	/* Does this device support configuring which video device to POST? */
929 	if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
930 		video->flags.post = 1;
931 		status = 0;
932 	}
933 
934 	return status;
935 }
936 
937 /*
938  * --------------------------------------------------------------------------
939  *                               Driver Interface
940  * --------------------------------------------------------------------------
941  */
942 
943 /* device interface */
944 static struct acpi_video_device_attrib *
945 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
946 {
947 	struct acpi_video_enumerated_device *ids;
948 	int i;
949 
950 	for (i = 0; i < video->attached_count; i++) {
951 		ids = &video->attached_array[i];
952 		if ((ids->value.int_val & 0xffff) == device_id)
953 			return &ids->value.attrib;
954 	}
955 
956 	return NULL;
957 }
958 
959 static int
960 acpi_video_get_device_type(struct acpi_video_bus *video,
961 			   unsigned long device_id)
962 {
963 	struct acpi_video_enumerated_device *ids;
964 	int i;
965 
966 	for (i = 0; i < video->attached_count; i++) {
967 		ids = &video->attached_array[i];
968 		if ((ids->value.int_val & 0xffff) == device_id)
969 			return ids->value.int_val;
970 	}
971 
972 	return 0;
973 }
974 
975 static int
976 acpi_video_bus_get_one_device(struct acpi_device *device,
977 			      struct acpi_video_bus *video)
978 {
979 	unsigned long long device_id;
980 	int status, device_type;
981 	struct acpi_video_device *data;
982 	struct acpi_video_device_attrib *attribute;
983 
984 	status =
985 	    acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
986 	/* Some device omits _ADR, we skip them instead of fail */
987 	if (ACPI_FAILURE(status))
988 		return 0;
989 
990 	data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
991 	if (!data)
992 		return -ENOMEM;
993 
994 	strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
995 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
996 	device->driver_data = data;
997 
998 	data->device_id = device_id;
999 	data->video = video;
1000 	data->dev = device;
1001 	INIT_DELAYED_WORK(&data->switch_brightness_work,
1002 			  acpi_video_switch_brightness);
1003 
1004 	attribute = acpi_video_get_device_attr(video, device_id);
1005 
1006 	if (attribute && attribute->device_id_scheme) {
1007 		switch (attribute->display_type) {
1008 		case ACPI_VIDEO_DISPLAY_CRT:
1009 			data->flags.crt = 1;
1010 			break;
1011 		case ACPI_VIDEO_DISPLAY_TV:
1012 			data->flags.tvout = 1;
1013 			break;
1014 		case ACPI_VIDEO_DISPLAY_DVI:
1015 			data->flags.dvi = 1;
1016 			break;
1017 		case ACPI_VIDEO_DISPLAY_LCD:
1018 			data->flags.lcd = 1;
1019 			break;
1020 		default:
1021 			data->flags.unknown = 1;
1022 			break;
1023 		}
1024 		if (attribute->bios_can_detect)
1025 			data->flags.bios = 1;
1026 	} else {
1027 		/* Check for legacy IDs */
1028 		device_type = acpi_video_get_device_type(video, device_id);
1029 		/* Ignore bits 16 and 18-20 */
1030 		switch (device_type & 0xffe2ffff) {
1031 		case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1032 			data->flags.crt = 1;
1033 			break;
1034 		case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1035 			data->flags.lcd = 1;
1036 			break;
1037 		case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1038 			data->flags.tvout = 1;
1039 			break;
1040 		default:
1041 			data->flags.unknown = 1;
1042 		}
1043 	}
1044 
1045 	acpi_video_device_bind(video, data);
1046 	acpi_video_device_find_cap(data);
1047 
1048 	mutex_lock(&video->device_list_lock);
1049 	list_add_tail(&data->entry, &video->video_device_list);
1050 	mutex_unlock(&video->device_list_lock);
1051 
1052 	return status;
1053 }
1054 
1055 /*
1056  *  Arg:
1057  *	video	: video bus device
1058  *
1059  *  Return:
1060  *	none
1061  *
1062  *  Enumerate the video device list of the video bus,
1063  *  bind the ids with the corresponding video devices
1064  *  under the video bus.
1065  */
1066 
1067 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1068 {
1069 	struct acpi_video_device *dev;
1070 
1071 	mutex_lock(&video->device_list_lock);
1072 
1073 	list_for_each_entry(dev, &video->video_device_list, entry)
1074 		acpi_video_device_bind(video, dev);
1075 
1076 	mutex_unlock(&video->device_list_lock);
1077 }
1078 
1079 /*
1080  *  Arg:
1081  *	video	: video bus device
1082  *	device	: video output device under the video
1083  *		bus
1084  *
1085  *  Return:
1086  *	none
1087  *
1088  *  Bind the ids with the corresponding video devices
1089  *  under the video bus.
1090  */
1091 
1092 static void
1093 acpi_video_device_bind(struct acpi_video_bus *video,
1094 		       struct acpi_video_device *device)
1095 {
1096 	struct acpi_video_enumerated_device *ids;
1097 	int i;
1098 
1099 	for (i = 0; i < video->attached_count; i++) {
1100 		ids = &video->attached_array[i];
1101 		if (device->device_id == (ids->value.int_val & 0xffff)) {
1102 			ids->bind_info = device;
1103 			ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1104 		}
1105 	}
1106 }
1107 
1108 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1109 {
1110 	struct acpi_video_bus *video = device->video;
1111 	int i;
1112 
1113 	/*
1114 	 * If we have a broken _DOD or we have more than 8 output devices
1115 	 * under the graphics controller node that we can't proper deal with
1116 	 * in the operation region code currently, no need to test.
1117 	 */
1118 	if (!video->attached_count || video->child_count > 8)
1119 		return true;
1120 
1121 	for (i = 0; i < video->attached_count; i++) {
1122 		if ((video->attached_array[i].value.int_val & 0xfff) ==
1123 		    (device->device_id & 0xfff))
1124 			return true;
1125 	}
1126 
1127 	return false;
1128 }
1129 
1130 /*
1131  *  Arg:
1132  *	video	: video bus device
1133  *
1134  *  Return:
1135  *	< 0	: error
1136  *
1137  *  Call _DOD to enumerate all devices attached to display adapter
1138  *
1139  */
1140 
1141 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1142 {
1143 	int status;
1144 	int count;
1145 	int i;
1146 	struct acpi_video_enumerated_device *active_list;
1147 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1148 	union acpi_object *dod = NULL;
1149 	union acpi_object *obj;
1150 
1151 	status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1152 	if (!ACPI_SUCCESS(status)) {
1153 		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1154 		return status;
1155 	}
1156 
1157 	dod = buffer.pointer;
1158 	if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1159 		ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1160 		status = -EFAULT;
1161 		goto out;
1162 	}
1163 
1164 	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1165 			  dod->package.count));
1166 
1167 	active_list = kcalloc(1 + dod->package.count,
1168 			      sizeof(struct acpi_video_enumerated_device),
1169 			      GFP_KERNEL);
1170 	if (!active_list) {
1171 		status = -ENOMEM;
1172 		goto out;
1173 	}
1174 
1175 	count = 0;
1176 	for (i = 0; i < dod->package.count; i++) {
1177 		obj = &dod->package.elements[i];
1178 
1179 		if (obj->type != ACPI_TYPE_INTEGER) {
1180 			printk(KERN_ERR PREFIX
1181 				"Invalid _DOD data in element %d\n", i);
1182 			continue;
1183 		}
1184 
1185 		active_list[count].value.int_val = obj->integer.value;
1186 		active_list[count].bind_info = NULL;
1187 		ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1188 				  (int)obj->integer.value));
1189 		count++;
1190 	}
1191 
1192 	kfree(video->attached_array);
1193 
1194 	video->attached_array = active_list;
1195 	video->attached_count = count;
1196 
1197 out:
1198 	kfree(buffer.pointer);
1199 	return status;
1200 }
1201 
1202 static int
1203 acpi_video_get_next_level(struct acpi_video_device *device,
1204 			  u32 level_current, u32 event)
1205 {
1206 	int min, max, min_above, max_below, i, l, delta = 255;
1207 	max = max_below = 0;
1208 	min = min_above = 255;
1209 	/* Find closest level to level_current */
1210 	for (i = 2; i < device->brightness->count; i++) {
1211 		l = device->brightness->levels[i];
1212 		if (abs(l - level_current) < abs(delta)) {
1213 			delta = l - level_current;
1214 			if (!delta)
1215 				break;
1216 		}
1217 	}
1218 	/* Ajust level_current to closest available level */
1219 	level_current += delta;
1220 	for (i = 2; i < device->brightness->count; i++) {
1221 		l = device->brightness->levels[i];
1222 		if (l < min)
1223 			min = l;
1224 		if (l > max)
1225 			max = l;
1226 		if (l < min_above && l > level_current)
1227 			min_above = l;
1228 		if (l > max_below && l < level_current)
1229 			max_below = l;
1230 	}
1231 
1232 	switch (event) {
1233 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1234 		return (level_current < max) ? min_above : min;
1235 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1236 		return (level_current < max) ? min_above : max;
1237 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1238 		return (level_current > min) ? max_below : min;
1239 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1240 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1241 		return 0;
1242 	default:
1243 		return level_current;
1244 	}
1245 }
1246 
1247 static void
1248 acpi_video_switch_brightness(struct work_struct *work)
1249 {
1250 	struct acpi_video_device *device = container_of(to_delayed_work(work),
1251 			     struct acpi_video_device, switch_brightness_work);
1252 	unsigned long long level_current, level_next;
1253 	int event = device->switch_brightness_event;
1254 	int result = -EINVAL;
1255 
1256 	/* no warning message if acpi_backlight=vendor or a quirk is used */
1257 	if (!device->backlight)
1258 		return;
1259 
1260 	if (!device->brightness)
1261 		goto out;
1262 
1263 	result = acpi_video_device_lcd_get_level_current(device,
1264 							 &level_current,
1265 							 false);
1266 	if (result)
1267 		goto out;
1268 
1269 	level_next = acpi_video_get_next_level(device, level_current, event);
1270 
1271 	result = acpi_video_device_lcd_set_level(device, level_next);
1272 
1273 	if (!result)
1274 		backlight_force_update(device->backlight,
1275 				       BACKLIGHT_UPDATE_HOTKEY);
1276 
1277 out:
1278 	if (result)
1279 		printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1280 }
1281 
1282 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1283 			void **edid)
1284 {
1285 	struct acpi_video_bus *video;
1286 	struct acpi_video_device *video_device;
1287 	union acpi_object *buffer = NULL;
1288 	acpi_status status;
1289 	int i, length;
1290 
1291 	if (!device || !acpi_driver_data(device))
1292 		return -EINVAL;
1293 
1294 	video = acpi_driver_data(device);
1295 
1296 	for (i = 0; i < video->attached_count; i++) {
1297 		video_device = video->attached_array[i].bind_info;
1298 		length = 256;
1299 
1300 		if (!video_device)
1301 			continue;
1302 
1303 		if (!video_device->cap._DDC)
1304 			continue;
1305 
1306 		if (type) {
1307 			switch (type) {
1308 			case ACPI_VIDEO_DISPLAY_CRT:
1309 				if (!video_device->flags.crt)
1310 					continue;
1311 				break;
1312 			case ACPI_VIDEO_DISPLAY_TV:
1313 				if (!video_device->flags.tvout)
1314 					continue;
1315 				break;
1316 			case ACPI_VIDEO_DISPLAY_DVI:
1317 				if (!video_device->flags.dvi)
1318 					continue;
1319 				break;
1320 			case ACPI_VIDEO_DISPLAY_LCD:
1321 				if (!video_device->flags.lcd)
1322 					continue;
1323 				break;
1324 			}
1325 		} else if (video_device->device_id != device_id) {
1326 			continue;
1327 		}
1328 
1329 		status = acpi_video_device_EDID(video_device, &buffer, length);
1330 
1331 		if (ACPI_FAILURE(status) || !buffer ||
1332 		    buffer->type != ACPI_TYPE_BUFFER) {
1333 			length = 128;
1334 			status = acpi_video_device_EDID(video_device, &buffer,
1335 							length);
1336 			if (ACPI_FAILURE(status) || !buffer ||
1337 			    buffer->type != ACPI_TYPE_BUFFER) {
1338 				continue;
1339 			}
1340 		}
1341 
1342 		*edid = buffer->buffer.pointer;
1343 		return length;
1344 	}
1345 
1346 	return -ENODEV;
1347 }
1348 EXPORT_SYMBOL(acpi_video_get_edid);
1349 
1350 static int
1351 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1352 			   struct acpi_device *device)
1353 {
1354 	int status = 0;
1355 	struct acpi_device *dev;
1356 
1357 	/*
1358 	 * There are systems where video module known to work fine regardless
1359 	 * of broken _DOD and ignoring returned value here doesn't cause
1360 	 * any issues later.
1361 	 */
1362 	acpi_video_device_enumerate(video);
1363 
1364 	list_for_each_entry(dev, &device->children, node) {
1365 
1366 		status = acpi_video_bus_get_one_device(dev, video);
1367 		if (status) {
1368 			dev_err(&dev->dev, "Can't attach device\n");
1369 			break;
1370 		}
1371 		video->child_count++;
1372 	}
1373 	return status;
1374 }
1375 
1376 /* acpi_video interface */
1377 
1378 /*
1379  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1380  * preform any automatic brightness change on receiving a notification.
1381  */
1382 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1383 {
1384 	return acpi_video_bus_DOS(video, 0,
1385 				  acpi_osi_is_win8() ? 1 : 0);
1386 }
1387 
1388 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1389 {
1390 	return acpi_video_bus_DOS(video, 0,
1391 				  acpi_osi_is_win8() ? 0 : 1);
1392 }
1393 
1394 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1395 {
1396 	struct acpi_video_bus *video = acpi_driver_data(device);
1397 	struct input_dev *input;
1398 	int keycode = 0;
1399 
1400 	if (!video || !video->input)
1401 		return;
1402 
1403 	input = video->input;
1404 
1405 	switch (event) {
1406 	case ACPI_VIDEO_NOTIFY_SWITCH:	/* User requested a switch,
1407 					 * most likely via hotkey. */
1408 		keycode = KEY_SWITCHVIDEOMODE;
1409 		break;
1410 
1411 	case ACPI_VIDEO_NOTIFY_PROBE:	/* User plugged in or removed a video
1412 					 * connector. */
1413 		acpi_video_device_enumerate(video);
1414 		acpi_video_device_rebind(video);
1415 		keycode = KEY_SWITCHVIDEOMODE;
1416 		break;
1417 
1418 	case ACPI_VIDEO_NOTIFY_CYCLE:	/* Cycle Display output hotkey pressed. */
1419 		keycode = KEY_SWITCHVIDEOMODE;
1420 		break;
1421 	case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:	/* Next Display output hotkey pressed. */
1422 		keycode = KEY_VIDEO_NEXT;
1423 		break;
1424 	case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:	/* previous Display output hotkey pressed. */
1425 		keycode = KEY_VIDEO_PREV;
1426 		break;
1427 
1428 	default:
1429 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1430 				  "Unsupported event [0x%x]\n", event));
1431 		break;
1432 	}
1433 
1434 	if (acpi_notifier_call_chain(device, event, 0))
1435 		/* Something vetoed the keypress. */
1436 		keycode = 0;
1437 
1438 	if (keycode) {
1439 		input_report_key(input, keycode, 1);
1440 		input_sync(input);
1441 		input_report_key(input, keycode, 0);
1442 		input_sync(input);
1443 	}
1444 
1445 	return;
1446 }
1447 
1448 static void brightness_switch_event(struct acpi_video_device *video_device,
1449 				    u32 event)
1450 {
1451 	if (!brightness_switch_enabled)
1452 		return;
1453 
1454 	video_device->switch_brightness_event = event;
1455 	schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1456 }
1457 
1458 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1459 {
1460 	struct acpi_video_device *video_device = data;
1461 	struct acpi_device *device = NULL;
1462 	struct acpi_video_bus *bus;
1463 	struct input_dev *input;
1464 	int keycode = 0;
1465 
1466 	if (!video_device)
1467 		return;
1468 
1469 	device = video_device->dev;
1470 	bus = video_device->video;
1471 	input = bus->input;
1472 
1473 	switch (event) {
1474 	case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:	/* Cycle brightness */
1475 		brightness_switch_event(video_device, event);
1476 		keycode = KEY_BRIGHTNESS_CYCLE;
1477 		break;
1478 	case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:	/* Increase brightness */
1479 		brightness_switch_event(video_device, event);
1480 		keycode = KEY_BRIGHTNESSUP;
1481 		break;
1482 	case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:	/* Decrease brightness */
1483 		brightness_switch_event(video_device, event);
1484 		keycode = KEY_BRIGHTNESSDOWN;
1485 		break;
1486 	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightness */
1487 		brightness_switch_event(video_device, event);
1488 		keycode = KEY_BRIGHTNESS_ZERO;
1489 		break;
1490 	case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:	/* display device off */
1491 		brightness_switch_event(video_device, event);
1492 		keycode = KEY_DISPLAY_OFF;
1493 		break;
1494 	default:
1495 		ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1496 				  "Unsupported event [0x%x]\n", event));
1497 		break;
1498 	}
1499 
1500 	acpi_notifier_call_chain(device, event, 0);
1501 
1502 	if (keycode) {
1503 		input_report_key(input, keycode, 1);
1504 		input_sync(input);
1505 		input_report_key(input, keycode, 0);
1506 		input_sync(input);
1507 	}
1508 
1509 	return;
1510 }
1511 
1512 static int acpi_video_resume(struct notifier_block *nb,
1513 				unsigned long val, void *ign)
1514 {
1515 	struct acpi_video_bus *video;
1516 	struct acpi_video_device *video_device;
1517 	int i;
1518 
1519 	switch (val) {
1520 	case PM_HIBERNATION_PREPARE:
1521 	case PM_SUSPEND_PREPARE:
1522 	case PM_RESTORE_PREPARE:
1523 		return NOTIFY_DONE;
1524 	}
1525 
1526 	video = container_of(nb, struct acpi_video_bus, pm_nb);
1527 
1528 	dev_info(&video->device->dev, "Restoring backlight state\n");
1529 
1530 	for (i = 0; i < video->attached_count; i++) {
1531 		video_device = video->attached_array[i].bind_info;
1532 		if (video_device && video_device->brightness)
1533 			acpi_video_device_lcd_set_level(video_device,
1534 					video_device->brightness->curr);
1535 	}
1536 
1537 	return NOTIFY_OK;
1538 }
1539 
1540 static acpi_status
1541 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1542 			void **return_value)
1543 {
1544 	struct acpi_device *device = context;
1545 	struct acpi_device *sibling;
1546 	int result;
1547 
1548 	if (handle == device->handle)
1549 		return AE_CTRL_TERMINATE;
1550 
1551 	result = acpi_bus_get_device(handle, &sibling);
1552 	if (result)
1553 		return AE_OK;
1554 
1555 	if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1556 			return AE_ALREADY_EXISTS;
1557 
1558 	return AE_OK;
1559 }
1560 
1561 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1562 {
1563 	struct backlight_properties props;
1564 	struct pci_dev *pdev;
1565 	acpi_handle acpi_parent;
1566 	struct device *parent = NULL;
1567 	int result;
1568 	static int count;
1569 	char *name;
1570 
1571 	/*
1572 	 * Do not create backlight device for video output
1573 	 * device that is not in the enumerated list.
1574 	 */
1575 	if (!acpi_video_device_in_dod(device)) {
1576 		dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n");
1577 		return;
1578 	}
1579 
1580 	result = acpi_video_init_brightness(device);
1581 	if (result)
1582 		return;
1583 
1584 	if (disable_backlight_sysfs_if > 0)
1585 		return;
1586 
1587 	name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1588 	if (!name)
1589 		return;
1590 	count++;
1591 
1592 	acpi_get_parent(device->dev->handle, &acpi_parent);
1593 
1594 	pdev = acpi_get_pci_dev(acpi_parent);
1595 	if (pdev) {
1596 		parent = &pdev->dev;
1597 		pci_dev_put(pdev);
1598 	}
1599 
1600 	memset(&props, 0, sizeof(struct backlight_properties));
1601 	props.type = BACKLIGHT_FIRMWARE;
1602 	props.max_brightness = device->brightness->count - 3;
1603 	device->backlight = backlight_device_register(name,
1604 						      parent,
1605 						      device,
1606 						      &acpi_backlight_ops,
1607 						      &props);
1608 	kfree(name);
1609 	if (IS_ERR(device->backlight)) {
1610 		device->backlight = NULL;
1611 		return;
1612 	}
1613 
1614 	/*
1615 	 * Save current brightness level in case we have to restore it
1616 	 * before acpi_video_device_lcd_set_level() is called next time.
1617 	 */
1618 	device->backlight->props.brightness =
1619 			acpi_video_get_brightness(device->backlight);
1620 
1621 	device->cooling_dev = thermal_cooling_device_register("LCD",
1622 				device->dev, &video_cooling_ops);
1623 	if (IS_ERR(device->cooling_dev)) {
1624 		/*
1625 		 * Set cooling_dev to NULL so we don't crash trying to free it.
1626 		 * Also, why the hell we are returning early and not attempt to
1627 		 * register video output if cooling device registration failed?
1628 		 * -- dtor
1629 		 */
1630 		device->cooling_dev = NULL;
1631 		return;
1632 	}
1633 
1634 	dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1635 		 device->cooling_dev->id);
1636 	result = sysfs_create_link(&device->dev->dev.kobj,
1637 			&device->cooling_dev->device.kobj,
1638 			"thermal_cooling");
1639 	if (result)
1640 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1641 	result = sysfs_create_link(&device->cooling_dev->device.kobj,
1642 			&device->dev->dev.kobj, "device");
1643 	if (result)
1644 		printk(KERN_ERR PREFIX "Create sysfs link\n");
1645 }
1646 
1647 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1648 {
1649 	struct acpi_video_device *dev;
1650 	union acpi_object *levels;
1651 
1652 	mutex_lock(&video->device_list_lock);
1653 	list_for_each_entry(dev, &video->video_device_list, entry) {
1654 		if (!acpi_video_device_lcd_query_levels(dev, &levels))
1655 			kfree(levels);
1656 	}
1657 	mutex_unlock(&video->device_list_lock);
1658 }
1659 
1660 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1661 {
1662 	struct acpi_video_device *dev;
1663 
1664 	if (video->backlight_registered)
1665 		return 0;
1666 
1667 	acpi_video_run_bcl_for_osi(video);
1668 
1669 	if (acpi_video_get_backlight_type() != acpi_backlight_video)
1670 		return 0;
1671 
1672 	mutex_lock(&video->device_list_lock);
1673 	list_for_each_entry(dev, &video->video_device_list, entry)
1674 		acpi_video_dev_register_backlight(dev);
1675 	mutex_unlock(&video->device_list_lock);
1676 
1677 	video->backlight_registered = true;
1678 
1679 	video->pm_nb.notifier_call = acpi_video_resume;
1680 	video->pm_nb.priority = 0;
1681 	return register_pm_notifier(&video->pm_nb);
1682 }
1683 
1684 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1685 {
1686 	if (device->backlight) {
1687 		backlight_device_unregister(device->backlight);
1688 		device->backlight = NULL;
1689 	}
1690 	if (device->brightness) {
1691 		kfree(device->brightness->levels);
1692 		kfree(device->brightness);
1693 		device->brightness = NULL;
1694 	}
1695 	if (device->cooling_dev) {
1696 		sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1697 		sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1698 		thermal_cooling_device_unregister(device->cooling_dev);
1699 		device->cooling_dev = NULL;
1700 	}
1701 }
1702 
1703 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1704 {
1705 	struct acpi_video_device *dev;
1706 	int error;
1707 
1708 	if (!video->backlight_registered)
1709 		return 0;
1710 
1711 	error = unregister_pm_notifier(&video->pm_nb);
1712 
1713 	mutex_lock(&video->device_list_lock);
1714 	list_for_each_entry(dev, &video->video_device_list, entry)
1715 		acpi_video_dev_unregister_backlight(dev);
1716 	mutex_unlock(&video->device_list_lock);
1717 
1718 	video->backlight_registered = false;
1719 
1720 	return error;
1721 }
1722 
1723 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1724 {
1725 	acpi_status status;
1726 	struct acpi_device *adev = device->dev;
1727 
1728 	status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1729 					     acpi_video_device_notify, device);
1730 	if (ACPI_FAILURE(status))
1731 		dev_err(&adev->dev, "Error installing notify handler\n");
1732 	else
1733 		device->flags.notify = 1;
1734 }
1735 
1736 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1737 {
1738 	struct input_dev *input;
1739 	struct acpi_video_device *dev;
1740 	int error;
1741 
1742 	video->input = input = input_allocate_device();
1743 	if (!input) {
1744 		error = -ENOMEM;
1745 		goto out;
1746 	}
1747 
1748 	error = acpi_video_bus_start_devices(video);
1749 	if (error)
1750 		goto err_free_input;
1751 
1752 	snprintf(video->phys, sizeof(video->phys),
1753 			"%s/video/input0", acpi_device_hid(video->device));
1754 
1755 	input->name = acpi_device_name(video->device);
1756 	input->phys = video->phys;
1757 	input->id.bustype = BUS_HOST;
1758 	input->id.product = 0x06;
1759 	input->dev.parent = &video->device->dev;
1760 	input->evbit[0] = BIT(EV_KEY);
1761 	set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1762 	set_bit(KEY_VIDEO_NEXT, input->keybit);
1763 	set_bit(KEY_VIDEO_PREV, input->keybit);
1764 	set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1765 	set_bit(KEY_BRIGHTNESSUP, input->keybit);
1766 	set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1767 	set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1768 	set_bit(KEY_DISPLAY_OFF, input->keybit);
1769 
1770 	error = input_register_device(input);
1771 	if (error)
1772 		goto err_stop_dev;
1773 
1774 	mutex_lock(&video->device_list_lock);
1775 	list_for_each_entry(dev, &video->video_device_list, entry)
1776 		acpi_video_dev_add_notify_handler(dev);
1777 	mutex_unlock(&video->device_list_lock);
1778 
1779 	return 0;
1780 
1781 err_stop_dev:
1782 	acpi_video_bus_stop_devices(video);
1783 err_free_input:
1784 	input_free_device(input);
1785 	video->input = NULL;
1786 out:
1787 	return error;
1788 }
1789 
1790 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1791 {
1792 	if (dev->flags.notify) {
1793 		acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1794 					   acpi_video_device_notify);
1795 		dev->flags.notify = 0;
1796 	}
1797 }
1798 
1799 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1800 {
1801 	struct acpi_video_device *dev;
1802 
1803 	mutex_lock(&video->device_list_lock);
1804 	list_for_each_entry(dev, &video->video_device_list, entry)
1805 		acpi_video_dev_remove_notify_handler(dev);
1806 	mutex_unlock(&video->device_list_lock);
1807 
1808 	acpi_video_bus_stop_devices(video);
1809 	input_unregister_device(video->input);
1810 	video->input = NULL;
1811 }
1812 
1813 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1814 {
1815 	struct acpi_video_device *dev, *next;
1816 
1817 	mutex_lock(&video->device_list_lock);
1818 	list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1819 		list_del(&dev->entry);
1820 		kfree(dev);
1821 	}
1822 	mutex_unlock(&video->device_list_lock);
1823 
1824 	return 0;
1825 }
1826 
1827 static int instance;
1828 
1829 static int acpi_video_bus_add(struct acpi_device *device)
1830 {
1831 	struct acpi_video_bus *video;
1832 	int error;
1833 	acpi_status status;
1834 
1835 	status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1836 				device->parent->handle, 1,
1837 				acpi_video_bus_match, NULL,
1838 				device, NULL);
1839 	if (status == AE_ALREADY_EXISTS) {
1840 		printk(KERN_WARNING FW_BUG
1841 			"Duplicate ACPI video bus devices for the"
1842 			" same VGA controller, please try module "
1843 			"parameter \"video.allow_duplicates=1\""
1844 			"if the current driver doesn't work.\n");
1845 		if (!allow_duplicates)
1846 			return -ENODEV;
1847 	}
1848 
1849 	video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1850 	if (!video)
1851 		return -ENOMEM;
1852 
1853 	/* a hack to fix the duplicate name "VID" problem on T61 */
1854 	if (!strcmp(device->pnp.bus_id, "VID")) {
1855 		if (instance)
1856 			device->pnp.bus_id[3] = '0' + instance;
1857 		instance++;
1858 	}
1859 	/* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1860 	if (!strcmp(device->pnp.bus_id, "VGA")) {
1861 		if (instance)
1862 			device->pnp.bus_id[3] = '0' + instance;
1863 		instance++;
1864 	}
1865 
1866 	video->device = device;
1867 	strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1868 	strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1869 	device->driver_data = video;
1870 
1871 	acpi_video_bus_find_cap(video);
1872 	error = acpi_video_bus_check(video);
1873 	if (error)
1874 		goto err_free_video;
1875 
1876 	mutex_init(&video->device_list_lock);
1877 	INIT_LIST_HEAD(&video->video_device_list);
1878 
1879 	error = acpi_video_bus_get_devices(video, device);
1880 	if (error)
1881 		goto err_put_video;
1882 
1883 	printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1884 	       ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1885 	       video->flags.multihead ? "yes" : "no",
1886 	       video->flags.rom ? "yes" : "no",
1887 	       video->flags.post ? "yes" : "no");
1888 	mutex_lock(&video_list_lock);
1889 	list_add_tail(&video->entry, &video_bus_head);
1890 	mutex_unlock(&video_list_lock);
1891 
1892 	acpi_video_bus_register_backlight(video);
1893 	acpi_video_bus_add_notify_handler(video);
1894 
1895 	return 0;
1896 
1897 err_put_video:
1898 	acpi_video_bus_put_devices(video);
1899 	kfree(video->attached_array);
1900 err_free_video:
1901 	kfree(video);
1902 	device->driver_data = NULL;
1903 
1904 	return error;
1905 }
1906 
1907 static int acpi_video_bus_remove(struct acpi_device *device)
1908 {
1909 	struct acpi_video_bus *video = NULL;
1910 
1911 
1912 	if (!device || !acpi_driver_data(device))
1913 		return -EINVAL;
1914 
1915 	video = acpi_driver_data(device);
1916 
1917 	acpi_video_bus_remove_notify_handler(video);
1918 	acpi_video_bus_unregister_backlight(video);
1919 	acpi_video_bus_put_devices(video);
1920 
1921 	mutex_lock(&video_list_lock);
1922 	list_del(&video->entry);
1923 	mutex_unlock(&video_list_lock);
1924 
1925 	kfree(video->attached_array);
1926 	kfree(video);
1927 
1928 	return 0;
1929 }
1930 
1931 static int __init is_i740(struct pci_dev *dev)
1932 {
1933 	if (dev->device == 0x00D1)
1934 		return 1;
1935 	if (dev->device == 0x7000)
1936 		return 1;
1937 	return 0;
1938 }
1939 
1940 static int __init intel_opregion_present(void)
1941 {
1942 	int opregion = 0;
1943 	struct pci_dev *dev = NULL;
1944 	u32 address;
1945 
1946 	for_each_pci_dev(dev) {
1947 		if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
1948 			continue;
1949 		if (dev->vendor != PCI_VENDOR_ID_INTEL)
1950 			continue;
1951 		/* We don't want to poke around undefined i740 registers */
1952 		if (is_i740(dev))
1953 			continue;
1954 		pci_read_config_dword(dev, 0xfc, &address);
1955 		if (!address)
1956 			continue;
1957 		opregion = 1;
1958 	}
1959 	return opregion;
1960 }
1961 
1962 int acpi_video_register(void)
1963 {
1964 	int ret = 0;
1965 
1966 	mutex_lock(&register_count_mutex);
1967 	if (register_count) {
1968 		/*
1969 		 * if the function of acpi_video_register is already called,
1970 		 * don't register the acpi_vide_bus again and return no error.
1971 		 */
1972 		goto leave;
1973 	}
1974 
1975 	mutex_init(&video_list_lock);
1976 	INIT_LIST_HEAD(&video_bus_head);
1977 
1978 	dmi_check_system(video_dmi_table);
1979 
1980 	ret = acpi_bus_register_driver(&acpi_video_bus);
1981 	if (ret)
1982 		goto leave;
1983 
1984 	/*
1985 	 * When the acpi_video_bus is loaded successfully, increase
1986 	 * the counter reference.
1987 	 */
1988 	register_count = 1;
1989 
1990 leave:
1991 	mutex_unlock(&register_count_mutex);
1992 	return ret;
1993 }
1994 EXPORT_SYMBOL(acpi_video_register);
1995 
1996 void acpi_video_unregister(void)
1997 {
1998 	mutex_lock(&register_count_mutex);
1999 	if (register_count) {
2000 		acpi_bus_unregister_driver(&acpi_video_bus);
2001 		register_count = 0;
2002 	}
2003 	mutex_unlock(&register_count_mutex);
2004 }
2005 EXPORT_SYMBOL(acpi_video_unregister);
2006 
2007 void acpi_video_unregister_backlight(void)
2008 {
2009 	struct acpi_video_bus *video;
2010 
2011 	mutex_lock(&register_count_mutex);
2012 	if (register_count) {
2013 		mutex_lock(&video_list_lock);
2014 		list_for_each_entry(video, &video_bus_head, entry)
2015 			acpi_video_bus_unregister_backlight(video);
2016 		mutex_unlock(&video_list_lock);
2017 	}
2018 	mutex_unlock(&register_count_mutex);
2019 }
2020 
2021 /*
2022  * This is kind of nasty. Hardware using Intel chipsets may require
2023  * the video opregion code to be run first in order to initialise
2024  * state before any ACPI video calls are made. To handle this we defer
2025  * registration of the video class until the opregion code has run.
2026  */
2027 
2028 static int __init acpi_video_init(void)
2029 {
2030 	/*
2031 	 * Let the module load even if ACPI is disabled (e.g. due to
2032 	 * a broken BIOS) so that i915.ko can still be loaded on such
2033 	 * old systems without an AcpiOpRegion.
2034 	 *
2035 	 * acpi_video_register() will report -ENODEV later as well due
2036 	 * to acpi_disabled when i915.ko tries to register itself afterwards.
2037 	 */
2038 	if (acpi_disabled)
2039 		return 0;
2040 
2041 	if (intel_opregion_present())
2042 		return 0;
2043 
2044 	return acpi_video_register();
2045 }
2046 
2047 static void __exit acpi_video_exit(void)
2048 {
2049 	acpi_video_detect_exit();
2050 	acpi_video_unregister();
2051 
2052 	return;
2053 }
2054 
2055 module_init(acpi_video_init);
2056 module_exit(acpi_video_exit);
2057