ACPI / video: Only default only_lcd to true on Win8-ready _desktops_
[sfrench/cifs-2.6.git] / drivers / acpi / acpi_video.c
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 <linux/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
47 #define MAX_NAME_LEN    20
48
49 #define _COMPONENT              ACPI_VIDEO_COMPONENT
50 ACPI_MODULE_NAME("video");
51
52 MODULE_AUTHOR("Bruno Ducrot");
53 MODULE_DESCRIPTION("ACPI Video Driver");
54 MODULE_LICENSE("GPL");
55
56 static bool brightness_switch_enabled = true;
57 module_param(brightness_switch_enabled, bool, 0644);
58
59 /*
60  * By default, we don't allow duplicate ACPI video bus devices
61  * under the same VGA controller
62  */
63 static bool allow_duplicates;
64 module_param(allow_duplicates, bool, 0644);
65
66 static int disable_backlight_sysfs_if = -1;
67 module_param(disable_backlight_sysfs_if, int, 0444);
68
69 #define REPORT_OUTPUT_KEY_EVENTS                0x01
70 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
71 static int report_key_events = -1;
72 module_param(report_key_events, int, 0644);
73 MODULE_PARM_DESC(report_key_events,
74         "0: none, 1: output changes, 2: brightness changes, 3: all");
75
76 /*
77  * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
78  * assumed even if not actually set.
79  */
80 static bool device_id_scheme = false;
81 module_param(device_id_scheme, bool, 0444);
82
83 static int only_lcd = -1;
84 module_param(only_lcd, int, 0444);
85
86 static int register_count;
87 static DEFINE_MUTEX(register_count_mutex);
88 static DEFINE_MUTEX(video_list_lock);
89 static LIST_HEAD(video_bus_head);
90 static int acpi_video_bus_add(struct acpi_device *device);
91 static int acpi_video_bus_remove(struct acpi_device *device);
92 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
93 void acpi_video_detect_exit(void);
94
95 /*
96  * Indices in the _BCL method response: the first two items are special,
97  * the rest are all supported levels.
98  *
99  * See page 575 of the ACPI spec 3.0
100  */
101 enum acpi_video_level_idx {
102         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
103         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
104         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
105 };
106
107 static const struct acpi_device_id video_device_ids[] = {
108         {ACPI_VIDEO_HID, 0},
109         {"", 0},
110 };
111 MODULE_DEVICE_TABLE(acpi, video_device_ids);
112
113 static struct acpi_driver acpi_video_bus = {
114         .name = "video",
115         .class = ACPI_VIDEO_CLASS,
116         .ids = video_device_ids,
117         .ops = {
118                 .add = acpi_video_bus_add,
119                 .remove = acpi_video_bus_remove,
120                 .notify = acpi_video_bus_notify,
121                 },
122 };
123
124 struct acpi_video_bus_flags {
125         u8 multihead:1;         /* can switch video heads */
126         u8 rom:1;               /* can retrieve a video rom */
127         u8 post:1;              /* can configure the head to */
128         u8 reserved:5;
129 };
130
131 struct acpi_video_bus_cap {
132         u8 _DOS:1;              /* Enable/Disable output switching */
133         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
134         u8 _ROM:1;              /* Get ROM Data */
135         u8 _GPD:1;              /* Get POST Device */
136         u8 _SPD:1;              /* Set POST Device */
137         u8 _VPO:1;              /* Video POST Options */
138         u8 reserved:2;
139 };
140
141 struct acpi_video_device_attrib {
142         u32 display_index:4;    /* A zero-based instance of the Display */
143         u32 display_port_attachment:4;  /* This field differentiates the display type */
144         u32 display_type:4;     /* Describe the specific type in use */
145         u32 vendor_specific:4;  /* Chipset Vendor Specific */
146         u32 bios_can_detect:1;  /* BIOS can detect the device */
147         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
148                                    the VGA device. */
149         u32 pipe_id:3;          /* For VGA multiple-head devices. */
150         u32 reserved:10;        /* Must be 0 */
151
152         /*
153          * The device ID might not actually follow the scheme described by this
154          * struct acpi_video_device_attrib. If it does, then this bit
155          * device_id_scheme is set; otherwise, other fields should be ignored.
156          *
157          * (but also see the global flag device_id_scheme)
158          */
159         u32 device_id_scheme:1;
160 };
161
162 struct acpi_video_enumerated_device {
163         union {
164                 u32 int_val;
165                 struct acpi_video_device_attrib attrib;
166         } value;
167         struct acpi_video_device *bind_info;
168 };
169
170 struct acpi_video_bus {
171         struct acpi_device *device;
172         bool backlight_registered;
173         u8 dos_setting;
174         struct acpi_video_enumerated_device *attached_array;
175         u8 attached_count;
176         u8 child_count;
177         struct acpi_video_bus_cap cap;
178         struct acpi_video_bus_flags flags;
179         struct list_head video_device_list;
180         struct mutex device_list_lock;  /* protects video_device_list */
181         struct list_head entry;
182         struct input_dev *input;
183         char phys[32];  /* for input device */
184         struct notifier_block pm_nb;
185 };
186
187 struct acpi_video_device_flags {
188         u8 crt:1;
189         u8 lcd:1;
190         u8 tvout:1;
191         u8 dvi:1;
192         u8 bios:1;
193         u8 unknown:1;
194         u8 notify:1;
195         u8 reserved:1;
196 };
197
198 struct acpi_video_device_cap {
199         u8 _ADR:1;              /* Return the unique ID */
200         u8 _BCL:1;              /* Query list of brightness control levels supported */
201         u8 _BCM:1;              /* Set the brightness level */
202         u8 _BQC:1;              /* Get current brightness level */
203         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
204         u8 _DDC:1;              /* Return the EDID for this device */
205 };
206
207 struct acpi_video_device {
208         unsigned long device_id;
209         struct acpi_video_device_flags flags;
210         struct acpi_video_device_cap cap;
211         struct list_head entry;
212         struct delayed_work switch_brightness_work;
213         int switch_brightness_event;
214         struct acpi_video_bus *video;
215         struct acpi_device *dev;
216         struct acpi_video_device_brightness *brightness;
217         struct backlight_device *backlight;
218         struct thermal_cooling_device *cooling_dev;
219 };
220
221 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
222 static void acpi_video_device_rebind(struct acpi_video_bus *video);
223 static void acpi_video_device_bind(struct acpi_video_bus *video,
224                                    struct acpi_video_device *device);
225 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
226 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
227                         int level);
228 static int acpi_video_device_lcd_get_level_current(
229                         struct acpi_video_device *device,
230                         unsigned long long *level, bool raw);
231 static int acpi_video_get_next_level(struct acpi_video_device *device,
232                                      u32 level_current, u32 event);
233 static void acpi_video_switch_brightness(struct work_struct *work);
234
235 /* backlight device sysfs support */
236 static int acpi_video_get_brightness(struct backlight_device *bd)
237 {
238         unsigned long long cur_level;
239         int i;
240         struct acpi_video_device *vd = bl_get_data(bd);
241
242         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
243                 return -EINVAL;
244         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
245                 if (vd->brightness->levels[i] == cur_level)
246                         return i - ACPI_VIDEO_FIRST_LEVEL;
247         }
248         return 0;
249 }
250
251 static int acpi_video_set_brightness(struct backlight_device *bd)
252 {
253         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
254         struct acpi_video_device *vd = bl_get_data(bd);
255
256         cancel_delayed_work(&vd->switch_brightness_work);
257         return acpi_video_device_lcd_set_level(vd,
258                                 vd->brightness->levels[request_level]);
259 }
260
261 static const struct backlight_ops acpi_backlight_ops = {
262         .get_brightness = acpi_video_get_brightness,
263         .update_status  = acpi_video_set_brightness,
264 };
265
266 /* thermal cooling device callbacks */
267 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
268                                unsigned long *state)
269 {
270         struct acpi_device *device = cooling_dev->devdata;
271         struct acpi_video_device *video = acpi_driver_data(device);
272
273         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
274         return 0;
275 }
276
277 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
278                                unsigned long *state)
279 {
280         struct acpi_device *device = cooling_dev->devdata;
281         struct acpi_video_device *video = acpi_driver_data(device);
282         unsigned long long level;
283         int offset;
284
285         if (acpi_video_device_lcd_get_level_current(video, &level, false))
286                 return -EINVAL;
287         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
288              offset++)
289                 if (level == video->brightness->levels[offset]) {
290                         *state = video->brightness->count - offset - 1;
291                         return 0;
292                 }
293
294         return -EINVAL;
295 }
296
297 static int
298 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
299 {
300         struct acpi_device *device = cooling_dev->devdata;
301         struct acpi_video_device *video = acpi_driver_data(device);
302         int level;
303
304         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
305                 return -EINVAL;
306
307         state = video->brightness->count - state;
308         level = video->brightness->levels[state - 1];
309         return acpi_video_device_lcd_set_level(video, level);
310 }
311
312 static const struct thermal_cooling_device_ops video_cooling_ops = {
313         .get_max_state = video_get_max_state,
314         .get_cur_state = video_get_cur_state,
315         .set_cur_state = video_set_cur_state,
316 };
317
318 /*
319  * --------------------------------------------------------------------------
320  *                             Video Management
321  * --------------------------------------------------------------------------
322  */
323
324 static int
325 acpi_video_device_lcd_query_levels(acpi_handle handle,
326                                    union acpi_object **levels)
327 {
328         int status;
329         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
330         union acpi_object *obj;
331
332
333         *levels = NULL;
334
335         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
336         if (!ACPI_SUCCESS(status))
337                 return status;
338         obj = (union acpi_object *)buffer.pointer;
339         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
340                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
341                 status = -EFAULT;
342                 goto err;
343         }
344
345         *levels = obj;
346
347         return 0;
348
349 err:
350         kfree(buffer.pointer);
351
352         return status;
353 }
354
355 static int
356 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
357 {
358         int status;
359         int state;
360
361         status = acpi_execute_simple_method(device->dev->handle,
362                                             "_BCM", level);
363         if (ACPI_FAILURE(status)) {
364                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
365                 return -EIO;
366         }
367
368         device->brightness->curr = level;
369         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
370              state++)
371                 if (level == device->brightness->levels[state]) {
372                         if (device->backlight)
373                                 device->backlight->props.brightness =
374                                         state - ACPI_VIDEO_FIRST_LEVEL;
375                         return 0;
376                 }
377
378         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
379         return -EINVAL;
380 }
381
382 /*
383  * For some buggy _BQC methods, we need to add a constant value to
384  * the _BQC return value to get the actual current brightness level
385  */
386
387 static int bqc_offset_aml_bug_workaround;
388 static int video_set_bqc_offset(const struct dmi_system_id *d)
389 {
390         bqc_offset_aml_bug_workaround = 9;
391         return 0;
392 }
393
394 static int video_disable_backlight_sysfs_if(
395         const struct dmi_system_id *d)
396 {
397         if (disable_backlight_sysfs_if == -1)
398                 disable_backlight_sysfs_if = 1;
399         return 0;
400 }
401
402 static int video_set_device_id_scheme(const struct dmi_system_id *d)
403 {
404         device_id_scheme = true;
405         return 0;
406 }
407
408 static int video_enable_only_lcd(const struct dmi_system_id *d)
409 {
410         only_lcd = true;
411         return 0;
412 }
413
414 static int video_set_report_key_events(const struct dmi_system_id *id)
415 {
416         if (report_key_events == -1)
417                 report_key_events = (uintptr_t)id->driver_data;
418         return 0;
419 }
420
421 static const struct dmi_system_id video_dmi_table[] = {
422         /*
423          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
424          */
425         {
426          .callback = video_set_bqc_offset,
427          .ident = "Acer Aspire 5720",
428          .matches = {
429                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
430                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
431                 },
432         },
433         {
434          .callback = video_set_bqc_offset,
435          .ident = "Acer Aspire 5710Z",
436          .matches = {
437                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
438                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
439                 },
440         },
441         {
442          .callback = video_set_bqc_offset,
443          .ident = "eMachines E510",
444          .matches = {
445                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
446                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
447                 },
448         },
449         {
450          .callback = video_set_bqc_offset,
451          .ident = "Acer Aspire 5315",
452          .matches = {
453                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
454                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
455                 },
456         },
457         {
458          .callback = video_set_bqc_offset,
459          .ident = "Acer Aspire 7720",
460          .matches = {
461                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
462                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
463                 },
464         },
465
466         /*
467          * Some machines have a broken acpi-video interface for brightness
468          * control, but still need an acpi_video_device_lcd_set_level() call
469          * on resume to turn the backlight power on.  We Enable backlight
470          * control on these systems, but do not register a backlight sysfs
471          * as brightness control does not work.
472          */
473         {
474          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
475          .callback = video_disable_backlight_sysfs_if,
476          .ident = "Toshiba Portege R700",
477          .matches = {
478                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
479                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
480                 },
481         },
482         {
483          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
484          .callback = video_disable_backlight_sysfs_if,
485          .ident = "Toshiba Portege R830",
486          .matches = {
487                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
488                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
489                 },
490         },
491         {
492          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
493          .callback = video_disable_backlight_sysfs_if,
494          .ident = "Toshiba Satellite R830",
495          .matches = {
496                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
497                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
498                 },
499         },
500         /*
501          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
502          * but the IDs actually follow the Device ID Scheme.
503          */
504         {
505          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
506          .callback = video_set_device_id_scheme,
507          .ident = "ESPRIMO Mobile M9410",
508          .matches = {
509                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
510                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
511                 },
512         },
513         /*
514          * Some machines have multiple video output devices, but only the one
515          * that is the type of LCD can do the backlight control so we should not
516          * register backlight interface for other video output devices.
517          */
518         {
519          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
520          .callback = video_enable_only_lcd,
521          .ident = "ESPRIMO Mobile M9410",
522          .matches = {
523                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
524                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
525                 },
526         },
527         /*
528          * Some machines report wrong key events on the acpi-bus, suppress
529          * key event reporting on these.  Note this is only intended to work
530          * around events which are plain wrong. In some cases we get double
531          * events, in this case acpi-video is considered the canonical source
532          * and the events from the other source should be filtered. E.g.
533          * by calling acpi_video_handles_brightness_key_presses() from the
534          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
535          */
536         {
537          .callback = video_set_report_key_events,
538          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
539          .ident = "Dell Vostro V131",
540          .matches = {
541                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
542                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
543                 },
544         },
545         {}
546 };
547
548 static unsigned long long
549 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
550                               unsigned long long bqc_value)
551 {
552         unsigned long long level;
553
554         if (device->brightness->flags._BQC_use_index) {
555                 /*
556                  * _BQC returns an index that doesn't account for the first 2
557                  * items with special meaning (see enum acpi_video_level_idx),
558                  * so we need to compensate for that by offsetting ourselves
559                  */
560                 if (device->brightness->flags._BCL_reversed)
561                         bqc_value = device->brightness->count -
562                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
563
564                 level = device->brightness->levels[bqc_value +
565                                                    ACPI_VIDEO_FIRST_LEVEL];
566         } else {
567                 level = bqc_value;
568         }
569
570         level += bqc_offset_aml_bug_workaround;
571
572         return level;
573 }
574
575 static int
576 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
577                                         unsigned long long *level, bool raw)
578 {
579         acpi_status status = AE_OK;
580         int i;
581
582         if (device->cap._BQC || device->cap._BCQ) {
583                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
584
585                 status = acpi_evaluate_integer(device->dev->handle, buf,
586                                                 NULL, level);
587                 if (ACPI_SUCCESS(status)) {
588                         if (raw) {
589                                 /*
590                                  * Caller has indicated he wants the raw
591                                  * value returned by _BQC, so don't furtherly
592                                  * mess with the value.
593                                  */
594                                 return 0;
595                         }
596
597                         *level = acpi_video_bqc_value_to_level(device, *level);
598
599                         for (i = ACPI_VIDEO_FIRST_LEVEL;
600                              i < device->brightness->count; i++)
601                                 if (device->brightness->levels[i] == *level) {
602                                         device->brightness->curr = *level;
603                                         return 0;
604                                 }
605                         /*
606                          * BQC returned an invalid level.
607                          * Stop using it.
608                          */
609                         ACPI_WARNING((AE_INFO,
610                                       "%s returned an invalid level",
611                                       buf));
612                         device->cap._BQC = device->cap._BCQ = 0;
613                 } else {
614                         /*
615                          * Fixme:
616                          * should we return an error or ignore this failure?
617                          * dev->brightness->curr is a cached value which stores
618                          * the correct current backlight level in most cases.
619                          * ACPI video backlight still works w/ buggy _BQC.
620                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
621                          */
622                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
623                         device->cap._BQC = device->cap._BCQ = 0;
624                 }
625         }
626
627         *level = device->brightness->curr;
628         return 0;
629 }
630
631 static int
632 acpi_video_device_EDID(struct acpi_video_device *device,
633                        union acpi_object **edid, ssize_t length)
634 {
635         int status;
636         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
637         union acpi_object *obj;
638         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
639         struct acpi_object_list args = { 1, &arg0 };
640
641
642         *edid = NULL;
643
644         if (!device)
645                 return -ENODEV;
646         if (length == 128)
647                 arg0.integer.value = 1;
648         else if (length == 256)
649                 arg0.integer.value = 2;
650         else
651                 return -EINVAL;
652
653         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
654         if (ACPI_FAILURE(status))
655                 return -ENODEV;
656
657         obj = buffer.pointer;
658
659         if (obj && obj->type == ACPI_TYPE_BUFFER)
660                 *edid = obj;
661         else {
662                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
663                 status = -EFAULT;
664                 kfree(obj);
665         }
666
667         return status;
668 }
669
670 /* bus */
671
672 /*
673  *  Arg:
674  *      video           : video bus device pointer
675  *      bios_flag       :
676  *              0.      The system BIOS should NOT automatically switch(toggle)
677  *                      the active display output.
678  *              1.      The system BIOS should automatically switch (toggle) the
679  *                      active display output. No switch event.
680  *              2.      The _DGS value should be locked.
681  *              3.      The system BIOS should not automatically switch (toggle) the
682  *                      active display output, but instead generate the display switch
683  *                      event notify code.
684  *      lcd_flag        :
685  *              0.      The system BIOS should automatically control the brightness level
686  *                      of the LCD when the power changes from AC to DC
687  *              1.      The system BIOS should NOT automatically control the brightness
688  *                      level of the LCD when the power changes from AC to DC.
689  *  Return Value:
690  *              -EINVAL wrong arg.
691  */
692
693 static int
694 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
695 {
696         acpi_status status;
697
698         if (!video->cap._DOS)
699                 return 0;
700
701         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
702                 return -EINVAL;
703         video->dos_setting = (lcd_flag << 2) | bios_flag;
704         status = acpi_execute_simple_method(video->device->handle, "_DOS",
705                                             (lcd_flag << 2) | bios_flag);
706         if (ACPI_FAILURE(status))
707                 return -EIO;
708
709         return 0;
710 }
711
712 /*
713  * Simple comparison function used to sort backlight levels.
714  */
715
716 static int
717 acpi_video_cmp_level(const void *a, const void *b)
718 {
719         return *(int *)a - *(int *)b;
720 }
721
722 /*
723  * Decides if _BQC/_BCQ for this system is usable
724  *
725  * We do this by changing the level first and then read out the current
726  * brightness level, if the value does not match, find out if it is using
727  * index. If not, clear the _BQC/_BCQ capability.
728  */
729 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
730                                 int max_level, int current_level)
731 {
732         struct acpi_video_device_brightness *br = device->brightness;
733         int result;
734         unsigned long long level;
735         int test_level;
736
737         /* don't mess with existing known broken systems */
738         if (bqc_offset_aml_bug_workaround)
739                 return 0;
740
741         /*
742          * Some systems always report current brightness level as maximum
743          * through _BQC, we need to test another value for them. However,
744          * there is a subtlety:
745          *
746          * If the _BCL package ordering is descending, the first level
747          * (br->levels[2]) is likely to be 0, and if the number of levels
748          * matches the number of steps, we might confuse a returned level to
749          * mean the index.
750          *
751          * For example:
752          *
753          *     current_level = max_level = 100
754          *     test_level = 0
755          *     returned level = 100
756          *
757          * In this case 100 means the level, not the index, and _BCM failed.
758          * Still, if the _BCL package ordering is descending, the index of
759          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
760          *
761          * This causes all _BQC calls to return bogus values causing weird
762          * behavior from the user's perspective.  For example:
763          *
764          * xbacklight -set 10; xbacklight -set 20;
765          *
766          * would flash to 90% and then slowly down to the desired level (20).
767          *
768          * The solution is simple; test anything other than the first level
769          * (e.g. 1).
770          */
771         test_level = current_level == max_level
772                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
773                 : max_level;
774
775         result = acpi_video_device_lcd_set_level(device, test_level);
776         if (result)
777                 return result;
778
779         result = acpi_video_device_lcd_get_level_current(device, &level, true);
780         if (result)
781                 return result;
782
783         if (level != test_level) {
784                 /* buggy _BQC found, need to find out if it uses index */
785                 if (level < br->count) {
786                         if (br->flags._BCL_reversed)
787                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
788                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
789                                 br->flags._BQC_use_index = 1;
790                 }
791
792                 if (!br->flags._BQC_use_index)
793                         device->cap._BQC = device->cap._BCQ = 0;
794         }
795
796         return 0;
797 }
798
799 int acpi_video_get_levels(struct acpi_device *device,
800                           struct acpi_video_device_brightness **dev_br,
801                           int *pmax_level)
802 {
803         union acpi_object *obj = NULL;
804         int i, max_level = 0, count = 0, level_ac_battery = 0;
805         union acpi_object *o;
806         struct acpi_video_device_brightness *br = NULL;
807         int result = 0;
808         u32 value;
809
810         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device->handle,
811                                                                 &obj))) {
812                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
813                                                 "LCD brightness level\n"));
814                 result = -ENODEV;
815                 goto out;
816         }
817
818         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
819                 result = -EINVAL;
820                 goto out;
821         }
822
823         br = kzalloc(sizeof(*br), GFP_KERNEL);
824         if (!br) {
825                 printk(KERN_ERR "can't allocate memory\n");
826                 result = -ENOMEM;
827                 goto out;
828         }
829
830         /*
831          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
832          * in order to account for buggy BIOS which don't export the first two
833          * special levels (see below)
834          */
835         br->levels = kmalloc((obj->package.count + ACPI_VIDEO_FIRST_LEVEL) *
836                              sizeof(*br->levels), GFP_KERNEL);
837         if (!br->levels) {
838                 result = -ENOMEM;
839                 goto out_free;
840         }
841
842         for (i = 0; i < obj->package.count; i++) {
843                 o = (union acpi_object *)&obj->package.elements[i];
844                 if (o->type != ACPI_TYPE_INTEGER) {
845                         printk(KERN_ERR PREFIX "Invalid data\n");
846                         continue;
847                 }
848                 value = (u32) o->integer.value;
849                 /* Skip duplicate entries */
850                 if (count > ACPI_VIDEO_FIRST_LEVEL
851                     && br->levels[count - 1] == value)
852                         continue;
853
854                 br->levels[count] = value;
855
856                 if (br->levels[count] > max_level)
857                         max_level = br->levels[count];
858                 count++;
859         }
860
861         /*
862          * some buggy BIOS don't export the levels
863          * when machine is on AC/Battery in _BCL package.
864          * In this case, the first two elements in _BCL packages
865          * are also supported brightness levels that OS should take care of.
866          */
867         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
868                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
869                         level_ac_battery++;
870                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
871                         level_ac_battery++;
872         }
873
874         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
875                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
876                 br->flags._BCL_no_ac_battery_levels = 1;
877                 for (i = (count - 1 + level_ac_battery);
878                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
879                         br->levels[i] = br->levels[i - level_ac_battery];
880                 count += level_ac_battery;
881         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
882                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
883
884         /* Check if the _BCL package is in a reversed order */
885         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
886                 br->flags._BCL_reversed = 1;
887                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
888                      count - ACPI_VIDEO_FIRST_LEVEL,
889                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
890                      acpi_video_cmp_level, NULL);
891         } else if (max_level != br->levels[count - 1])
892                 ACPI_ERROR((AE_INFO,
893                             "Found unordered _BCL package"));
894
895         br->count = count;
896         *dev_br = br;
897         if (pmax_level)
898                 *pmax_level = max_level;
899
900 out:
901         kfree(obj);
902         return result;
903 out_free:
904         kfree(br);
905         goto out;
906 }
907 EXPORT_SYMBOL(acpi_video_get_levels);
908
909 /*
910  *  Arg:
911  *      device  : video output device (LCD, CRT, ..)
912  *
913  *  Return Value:
914  *      Maximum brightness level
915  *
916  *  Allocate and initialize device->brightness.
917  */
918
919 static int
920 acpi_video_init_brightness(struct acpi_video_device *device)
921 {
922         int i, max_level = 0;
923         unsigned long long level, level_old;
924         struct acpi_video_device_brightness *br = NULL;
925         int result = -EINVAL;
926
927         result = acpi_video_get_levels(device->dev, &br, &max_level);
928         if (result)
929                 return result;
930         device->brightness = br;
931
932         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
933         br->curr = level = max_level;
934
935         if (!device->cap._BQC)
936                 goto set_level;
937
938         result = acpi_video_device_lcd_get_level_current(device,
939                                                          &level_old, true);
940         if (result)
941                 goto out_free_levels;
942
943         result = acpi_video_bqc_quirk(device, max_level, level_old);
944         if (result)
945                 goto out_free_levels;
946         /*
947          * cap._BQC may get cleared due to _BQC is found to be broken
948          * in acpi_video_bqc_quirk, so check again here.
949          */
950         if (!device->cap._BQC)
951                 goto set_level;
952
953         level = acpi_video_bqc_value_to_level(device, level_old);
954         /*
955          * On some buggy laptops, _BQC returns an uninitialized
956          * value when invoked for the first time, i.e.
957          * level_old is invalid (no matter whether it's a level
958          * or an index). Set the backlight to max_level in this case.
959          */
960         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
961                 if (level == br->levels[i])
962                         break;
963         if (i == br->count || !level)
964                 level = max_level;
965
966 set_level:
967         result = acpi_video_device_lcd_set_level(device, level);
968         if (result)
969                 goto out_free_levels;
970
971         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
972                           "found %d brightness levels\n",
973                           br->count - ACPI_VIDEO_FIRST_LEVEL));
974         return 0;
975
976 out_free_levels:
977         kfree(br->levels);
978         kfree(br);
979         device->brightness = NULL;
980         return result;
981 }
982
983 /*
984  *  Arg:
985  *      device  : video output device (LCD, CRT, ..)
986  *
987  *  Return Value:
988  *      None
989  *
990  *  Find out all required AML methods defined under the output
991  *  device.
992  */
993
994 static void acpi_video_device_find_cap(struct acpi_video_device *device)
995 {
996         if (acpi_has_method(device->dev->handle, "_ADR"))
997                 device->cap._ADR = 1;
998         if (acpi_has_method(device->dev->handle, "_BCL"))
999                 device->cap._BCL = 1;
1000         if (acpi_has_method(device->dev->handle, "_BCM"))
1001                 device->cap._BCM = 1;
1002         if (acpi_has_method(device->dev->handle, "_BQC")) {
1003                 device->cap._BQC = 1;
1004         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1005                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
1006                 device->cap._BCQ = 1;
1007         }
1008
1009         if (acpi_has_method(device->dev->handle, "_DDC"))
1010                 device->cap._DDC = 1;
1011 }
1012
1013 /*
1014  *  Arg:
1015  *      device  : video output device (VGA)
1016  *
1017  *  Return Value:
1018  *      None
1019  *
1020  *  Find out all required AML methods defined under the video bus device.
1021  */
1022
1023 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1024 {
1025         if (acpi_has_method(video->device->handle, "_DOS"))
1026                 video->cap._DOS = 1;
1027         if (acpi_has_method(video->device->handle, "_DOD"))
1028                 video->cap._DOD = 1;
1029         if (acpi_has_method(video->device->handle, "_ROM"))
1030                 video->cap._ROM = 1;
1031         if (acpi_has_method(video->device->handle, "_GPD"))
1032                 video->cap._GPD = 1;
1033         if (acpi_has_method(video->device->handle, "_SPD"))
1034                 video->cap._SPD = 1;
1035         if (acpi_has_method(video->device->handle, "_VPO"))
1036                 video->cap._VPO = 1;
1037 }
1038
1039 /*
1040  * Check whether the video bus device has required AML method to
1041  * support the desired features
1042  */
1043
1044 static int acpi_video_bus_check(struct acpi_video_bus *video)
1045 {
1046         acpi_status status = -ENOENT;
1047         struct pci_dev *dev;
1048
1049         if (!video)
1050                 return -EINVAL;
1051
1052         dev = acpi_get_pci_dev(video->device->handle);
1053         if (!dev)
1054                 return -ENODEV;
1055         pci_dev_put(dev);
1056
1057         /*
1058          * Since there is no HID, CID and so on for VGA driver, we have
1059          * to check well known required nodes.
1060          */
1061
1062         /* Does this device support video switching? */
1063         if (video->cap._DOS || video->cap._DOD) {
1064                 if (!video->cap._DOS) {
1065                         printk(KERN_WARNING FW_BUG
1066                                 "ACPI(%s) defines _DOD but not _DOS\n",
1067                                 acpi_device_bid(video->device));
1068                 }
1069                 video->flags.multihead = 1;
1070                 status = 0;
1071         }
1072
1073         /* Does this device support retrieving a video ROM? */
1074         if (video->cap._ROM) {
1075                 video->flags.rom = 1;
1076                 status = 0;
1077         }
1078
1079         /* Does this device support configuring which video device to POST? */
1080         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1081                 video->flags.post = 1;
1082                 status = 0;
1083         }
1084
1085         return status;
1086 }
1087
1088 /*
1089  * --------------------------------------------------------------------------
1090  *                               Driver Interface
1091  * --------------------------------------------------------------------------
1092  */
1093
1094 /* device interface */
1095 static struct acpi_video_device_attrib *
1096 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1097 {
1098         struct acpi_video_enumerated_device *ids;
1099         int i;
1100
1101         for (i = 0; i < video->attached_count; i++) {
1102                 ids = &video->attached_array[i];
1103                 if ((ids->value.int_val & 0xffff) == device_id)
1104                         return &ids->value.attrib;
1105         }
1106
1107         return NULL;
1108 }
1109
1110 static int
1111 acpi_video_get_device_type(struct acpi_video_bus *video,
1112                            unsigned long device_id)
1113 {
1114         struct acpi_video_enumerated_device *ids;
1115         int i;
1116
1117         for (i = 0; i < video->attached_count; i++) {
1118                 ids = &video->attached_array[i];
1119                 if ((ids->value.int_val & 0xffff) == device_id)
1120                         return ids->value.int_val;
1121         }
1122
1123         return 0;
1124 }
1125
1126 static int
1127 acpi_video_bus_get_one_device(struct acpi_device *device,
1128                               struct acpi_video_bus *video)
1129 {
1130         unsigned long long device_id;
1131         int status, device_type;
1132         struct acpi_video_device *data;
1133         struct acpi_video_device_attrib *attribute;
1134
1135         status =
1136             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1137         /* Some device omits _ADR, we skip them instead of fail */
1138         if (ACPI_FAILURE(status))
1139                 return 0;
1140
1141         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1142         if (!data)
1143                 return -ENOMEM;
1144
1145         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1146         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1147         device->driver_data = data;
1148
1149         data->device_id = device_id;
1150         data->video = video;
1151         data->dev = device;
1152         INIT_DELAYED_WORK(&data->switch_brightness_work,
1153                           acpi_video_switch_brightness);
1154
1155         attribute = acpi_video_get_device_attr(video, device_id);
1156
1157         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1158                 switch (attribute->display_type) {
1159                 case ACPI_VIDEO_DISPLAY_CRT:
1160                         data->flags.crt = 1;
1161                         break;
1162                 case ACPI_VIDEO_DISPLAY_TV:
1163                         data->flags.tvout = 1;
1164                         break;
1165                 case ACPI_VIDEO_DISPLAY_DVI:
1166                         data->flags.dvi = 1;
1167                         break;
1168                 case ACPI_VIDEO_DISPLAY_LCD:
1169                         data->flags.lcd = 1;
1170                         break;
1171                 default:
1172                         data->flags.unknown = 1;
1173                         break;
1174                 }
1175                 if (attribute->bios_can_detect)
1176                         data->flags.bios = 1;
1177         } else {
1178                 /* Check for legacy IDs */
1179                 device_type = acpi_video_get_device_type(video, device_id);
1180                 /* Ignore bits 16 and 18-20 */
1181                 switch (device_type & 0xffe2ffff) {
1182                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1183                         data->flags.crt = 1;
1184                         break;
1185                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1186                         data->flags.lcd = 1;
1187                         break;
1188                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1189                         data->flags.tvout = 1;
1190                         break;
1191                 default:
1192                         data->flags.unknown = 1;
1193                 }
1194         }
1195
1196         acpi_video_device_bind(video, data);
1197         acpi_video_device_find_cap(data);
1198
1199         mutex_lock(&video->device_list_lock);
1200         list_add_tail(&data->entry, &video->video_device_list);
1201         mutex_unlock(&video->device_list_lock);
1202
1203         return status;
1204 }
1205
1206 /*
1207  *  Arg:
1208  *      video   : video bus device
1209  *
1210  *  Return:
1211  *      none
1212  *
1213  *  Enumerate the video device list of the video bus,
1214  *  bind the ids with the corresponding video devices
1215  *  under the video bus.
1216  */
1217
1218 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1219 {
1220         struct acpi_video_device *dev;
1221
1222         mutex_lock(&video->device_list_lock);
1223
1224         list_for_each_entry(dev, &video->video_device_list, entry)
1225                 acpi_video_device_bind(video, dev);
1226
1227         mutex_unlock(&video->device_list_lock);
1228 }
1229
1230 /*
1231  *  Arg:
1232  *      video   : video bus device
1233  *      device  : video output device under the video
1234  *              bus
1235  *
1236  *  Return:
1237  *      none
1238  *
1239  *  Bind the ids with the corresponding video devices
1240  *  under the video bus.
1241  */
1242
1243 static void
1244 acpi_video_device_bind(struct acpi_video_bus *video,
1245                        struct acpi_video_device *device)
1246 {
1247         struct acpi_video_enumerated_device *ids;
1248         int i;
1249
1250         for (i = 0; i < video->attached_count; i++) {
1251                 ids = &video->attached_array[i];
1252                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1253                         ids->bind_info = device;
1254                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1255                 }
1256         }
1257 }
1258
1259 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1260 {
1261         struct acpi_video_bus *video = device->video;
1262         int i;
1263
1264         /*
1265          * If we have a broken _DOD or we have more than 8 output devices
1266          * under the graphics controller node that we can't proper deal with
1267          * in the operation region code currently, no need to test.
1268          */
1269         if (!video->attached_count || video->child_count > 8)
1270                 return true;
1271
1272         for (i = 0; i < video->attached_count; i++) {
1273                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1274                     (device->device_id & 0xfff))
1275                         return true;
1276         }
1277
1278         return false;
1279 }
1280
1281 /*
1282  *  Arg:
1283  *      video   : video bus device
1284  *
1285  *  Return:
1286  *      < 0     : error
1287  *
1288  *  Call _DOD to enumerate all devices attached to display adapter
1289  *
1290  */
1291
1292 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1293 {
1294         int status;
1295         int count;
1296         int i;
1297         struct acpi_video_enumerated_device *active_list;
1298         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1299         union acpi_object *dod = NULL;
1300         union acpi_object *obj;
1301
1302         if (!video->cap._DOD)
1303                 return AE_NOT_EXIST;
1304
1305         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1306         if (!ACPI_SUCCESS(status)) {
1307                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1308                 return status;
1309         }
1310
1311         dod = buffer.pointer;
1312         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1313                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1314                 status = -EFAULT;
1315                 goto out;
1316         }
1317
1318         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1319                           dod->package.count));
1320
1321         active_list = kcalloc(1 + dod->package.count,
1322                               sizeof(struct acpi_video_enumerated_device),
1323                               GFP_KERNEL);
1324         if (!active_list) {
1325                 status = -ENOMEM;
1326                 goto out;
1327         }
1328
1329         count = 0;
1330         for (i = 0; i < dod->package.count; i++) {
1331                 obj = &dod->package.elements[i];
1332
1333                 if (obj->type != ACPI_TYPE_INTEGER) {
1334                         printk(KERN_ERR PREFIX
1335                                 "Invalid _DOD data in element %d\n", i);
1336                         continue;
1337                 }
1338
1339                 active_list[count].value.int_val = obj->integer.value;
1340                 active_list[count].bind_info = NULL;
1341                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1342                                   (int)obj->integer.value));
1343                 count++;
1344         }
1345
1346         kfree(video->attached_array);
1347
1348         video->attached_array = active_list;
1349         video->attached_count = count;
1350
1351 out:
1352         kfree(buffer.pointer);
1353         return status;
1354 }
1355
1356 static int
1357 acpi_video_get_next_level(struct acpi_video_device *device,
1358                           u32 level_current, u32 event)
1359 {
1360         int min, max, min_above, max_below, i, l, delta = 255;
1361         max = max_below = 0;
1362         min = min_above = 255;
1363         /* Find closest level to level_current */
1364         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1365                 l = device->brightness->levels[i];
1366                 if (abs(l - level_current) < abs(delta)) {
1367                         delta = l - level_current;
1368                         if (!delta)
1369                                 break;
1370                 }
1371         }
1372         /* Ajust level_current to closest available level */
1373         level_current += delta;
1374         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1375                 l = device->brightness->levels[i];
1376                 if (l < min)
1377                         min = l;
1378                 if (l > max)
1379                         max = l;
1380                 if (l < min_above && l > level_current)
1381                         min_above = l;
1382                 if (l > max_below && l < level_current)
1383                         max_below = l;
1384         }
1385
1386         switch (event) {
1387         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1388                 return (level_current < max) ? min_above : min;
1389         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1390                 return (level_current < max) ? min_above : max;
1391         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1392                 return (level_current > min) ? max_below : min;
1393         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1394         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1395                 return 0;
1396         default:
1397                 return level_current;
1398         }
1399 }
1400
1401 static void
1402 acpi_video_switch_brightness(struct work_struct *work)
1403 {
1404         struct acpi_video_device *device = container_of(to_delayed_work(work),
1405                              struct acpi_video_device, switch_brightness_work);
1406         unsigned long long level_current, level_next;
1407         int event = device->switch_brightness_event;
1408         int result = -EINVAL;
1409
1410         /* no warning message if acpi_backlight=vendor or a quirk is used */
1411         if (!device->backlight)
1412                 return;
1413
1414         if (!device->brightness)
1415                 goto out;
1416
1417         result = acpi_video_device_lcd_get_level_current(device,
1418                                                          &level_current,
1419                                                          false);
1420         if (result)
1421                 goto out;
1422
1423         level_next = acpi_video_get_next_level(device, level_current, event);
1424
1425         result = acpi_video_device_lcd_set_level(device, level_next);
1426
1427         if (!result)
1428                 backlight_force_update(device->backlight,
1429                                        BACKLIGHT_UPDATE_HOTKEY);
1430
1431 out:
1432         if (result)
1433                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1434 }
1435
1436 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1437                         void **edid)
1438 {
1439         struct acpi_video_bus *video;
1440         struct acpi_video_device *video_device;
1441         union acpi_object *buffer = NULL;
1442         acpi_status status;
1443         int i, length;
1444
1445         if (!device || !acpi_driver_data(device))
1446                 return -EINVAL;
1447
1448         video = acpi_driver_data(device);
1449
1450         for (i = 0; i < video->attached_count; i++) {
1451                 video_device = video->attached_array[i].bind_info;
1452                 length = 256;
1453
1454                 if (!video_device)
1455                         continue;
1456
1457                 if (!video_device->cap._DDC)
1458                         continue;
1459
1460                 if (type) {
1461                         switch (type) {
1462                         case ACPI_VIDEO_DISPLAY_CRT:
1463                                 if (!video_device->flags.crt)
1464                                         continue;
1465                                 break;
1466                         case ACPI_VIDEO_DISPLAY_TV:
1467                                 if (!video_device->flags.tvout)
1468                                         continue;
1469                                 break;
1470                         case ACPI_VIDEO_DISPLAY_DVI:
1471                                 if (!video_device->flags.dvi)
1472                                         continue;
1473                                 break;
1474                         case ACPI_VIDEO_DISPLAY_LCD:
1475                                 if (!video_device->flags.lcd)
1476                                         continue;
1477                                 break;
1478                         }
1479                 } else if (video_device->device_id != device_id) {
1480                         continue;
1481                 }
1482
1483                 status = acpi_video_device_EDID(video_device, &buffer, length);
1484
1485                 if (ACPI_FAILURE(status) || !buffer ||
1486                     buffer->type != ACPI_TYPE_BUFFER) {
1487                         length = 128;
1488                         status = acpi_video_device_EDID(video_device, &buffer,
1489                                                         length);
1490                         if (ACPI_FAILURE(status) || !buffer ||
1491                             buffer->type != ACPI_TYPE_BUFFER) {
1492                                 continue;
1493                         }
1494                 }
1495
1496                 *edid = buffer->buffer.pointer;
1497                 return length;
1498         }
1499
1500         return -ENODEV;
1501 }
1502 EXPORT_SYMBOL(acpi_video_get_edid);
1503
1504 static int
1505 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1506                            struct acpi_device *device)
1507 {
1508         int status = 0;
1509         struct acpi_device *dev;
1510
1511         /*
1512          * There are systems where video module known to work fine regardless
1513          * of broken _DOD and ignoring returned value here doesn't cause
1514          * any issues later.
1515          */
1516         acpi_video_device_enumerate(video);
1517
1518         list_for_each_entry(dev, &device->children, node) {
1519
1520                 status = acpi_video_bus_get_one_device(dev, video);
1521                 if (status) {
1522                         dev_err(&dev->dev, "Can't attach device\n");
1523                         break;
1524                 }
1525                 video->child_count++;
1526         }
1527         return status;
1528 }
1529
1530 /* acpi_video interface */
1531
1532 /*
1533  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1534  * preform any automatic brightness change on receiving a notification.
1535  */
1536 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1537 {
1538         return acpi_video_bus_DOS(video, 0,
1539                                   acpi_osi_is_win8() ? 1 : 0);
1540 }
1541
1542 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1543 {
1544         return acpi_video_bus_DOS(video, 0,
1545                                   acpi_osi_is_win8() ? 0 : 1);
1546 }
1547
1548 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1549 {
1550         struct acpi_video_bus *video = acpi_driver_data(device);
1551         struct input_dev *input;
1552         int keycode = 0;
1553
1554         if (!video || !video->input)
1555                 return;
1556
1557         input = video->input;
1558
1559         switch (event) {
1560         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1561                                          * most likely via hotkey. */
1562                 keycode = KEY_SWITCHVIDEOMODE;
1563                 break;
1564
1565         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1566                                          * connector. */
1567                 acpi_video_device_enumerate(video);
1568                 acpi_video_device_rebind(video);
1569                 keycode = KEY_SWITCHVIDEOMODE;
1570                 break;
1571
1572         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1573                 keycode = KEY_SWITCHVIDEOMODE;
1574                 break;
1575         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1576                 keycode = KEY_VIDEO_NEXT;
1577                 break;
1578         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1579                 keycode = KEY_VIDEO_PREV;
1580                 break;
1581
1582         default:
1583                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1584                                   "Unsupported event [0x%x]\n", event));
1585                 break;
1586         }
1587
1588         if (acpi_notifier_call_chain(device, event, 0))
1589                 /* Something vetoed the keypress. */
1590                 keycode = 0;
1591
1592         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1593                 input_report_key(input, keycode, 1);
1594                 input_sync(input);
1595                 input_report_key(input, keycode, 0);
1596                 input_sync(input);
1597         }
1598
1599         return;
1600 }
1601
1602 static void brightness_switch_event(struct acpi_video_device *video_device,
1603                                     u32 event)
1604 {
1605         if (!brightness_switch_enabled)
1606                 return;
1607
1608         video_device->switch_brightness_event = event;
1609         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1610 }
1611
1612 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1613 {
1614         struct acpi_video_device *video_device = data;
1615         struct acpi_device *device = NULL;
1616         struct acpi_video_bus *bus;
1617         struct input_dev *input;
1618         int keycode = 0;
1619
1620         if (!video_device)
1621                 return;
1622
1623         device = video_device->dev;
1624         bus = video_device->video;
1625         input = bus->input;
1626
1627         switch (event) {
1628         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1629                 brightness_switch_event(video_device, event);
1630                 keycode = KEY_BRIGHTNESS_CYCLE;
1631                 break;
1632         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1633                 brightness_switch_event(video_device, event);
1634                 keycode = KEY_BRIGHTNESSUP;
1635                 break;
1636         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1637                 brightness_switch_event(video_device, event);
1638                 keycode = KEY_BRIGHTNESSDOWN;
1639                 break;
1640         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1641                 brightness_switch_event(video_device, event);
1642                 keycode = KEY_BRIGHTNESS_ZERO;
1643                 break;
1644         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1645                 brightness_switch_event(video_device, event);
1646                 keycode = KEY_DISPLAY_OFF;
1647                 break;
1648         default:
1649                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1650                                   "Unsupported event [0x%x]\n", event));
1651                 break;
1652         }
1653
1654         acpi_notifier_call_chain(device, event, 0);
1655
1656         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1657                 input_report_key(input, keycode, 1);
1658                 input_sync(input);
1659                 input_report_key(input, keycode, 0);
1660                 input_sync(input);
1661         }
1662
1663         return;
1664 }
1665
1666 static int acpi_video_resume(struct notifier_block *nb,
1667                                 unsigned long val, void *ign)
1668 {
1669         struct acpi_video_bus *video;
1670         struct acpi_video_device *video_device;
1671         int i;
1672
1673         switch (val) {
1674         case PM_HIBERNATION_PREPARE:
1675         case PM_SUSPEND_PREPARE:
1676         case PM_RESTORE_PREPARE:
1677                 return NOTIFY_DONE;
1678         }
1679
1680         video = container_of(nb, struct acpi_video_bus, pm_nb);
1681
1682         dev_info(&video->device->dev, "Restoring backlight state\n");
1683
1684         for (i = 0; i < video->attached_count; i++) {
1685                 video_device = video->attached_array[i].bind_info;
1686                 if (video_device && video_device->brightness)
1687                         acpi_video_device_lcd_set_level(video_device,
1688                                         video_device->brightness->curr);
1689         }
1690
1691         return NOTIFY_OK;
1692 }
1693
1694 static acpi_status
1695 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1696                         void **return_value)
1697 {
1698         struct acpi_device *device = context;
1699         struct acpi_device *sibling;
1700         int result;
1701
1702         if (handle == device->handle)
1703                 return AE_CTRL_TERMINATE;
1704
1705         result = acpi_bus_get_device(handle, &sibling);
1706         if (result)
1707                 return AE_OK;
1708
1709         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1710                         return AE_ALREADY_EXISTS;
1711
1712         return AE_OK;
1713 }
1714
1715 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1716 {
1717         struct backlight_properties props;
1718         struct pci_dev *pdev;
1719         acpi_handle acpi_parent;
1720         struct device *parent = NULL;
1721         int result;
1722         static int count;
1723         char *name;
1724
1725         result = acpi_video_init_brightness(device);
1726         if (result)
1727                 return;
1728
1729         if (disable_backlight_sysfs_if > 0)
1730                 return;
1731
1732         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1733         if (!name)
1734                 return;
1735         count++;
1736
1737         acpi_get_parent(device->dev->handle, &acpi_parent);
1738
1739         pdev = acpi_get_pci_dev(acpi_parent);
1740         if (pdev) {
1741                 parent = &pdev->dev;
1742                 pci_dev_put(pdev);
1743         }
1744
1745         memset(&props, 0, sizeof(struct backlight_properties));
1746         props.type = BACKLIGHT_FIRMWARE;
1747         props.max_brightness =
1748                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1749         device->backlight = backlight_device_register(name,
1750                                                       parent,
1751                                                       device,
1752                                                       &acpi_backlight_ops,
1753                                                       &props);
1754         kfree(name);
1755         if (IS_ERR(device->backlight)) {
1756                 device->backlight = NULL;
1757                 return;
1758         }
1759
1760         /*
1761          * Save current brightness level in case we have to restore it
1762          * before acpi_video_device_lcd_set_level() is called next time.
1763          */
1764         device->backlight->props.brightness =
1765                         acpi_video_get_brightness(device->backlight);
1766
1767         device->cooling_dev = thermal_cooling_device_register("LCD",
1768                                 device->dev, &video_cooling_ops);
1769         if (IS_ERR(device->cooling_dev)) {
1770                 /*
1771                  * Set cooling_dev to NULL so we don't crash trying to free it.
1772                  * Also, why the hell we are returning early and not attempt to
1773                  * register video output if cooling device registration failed?
1774                  * -- dtor
1775                  */
1776                 device->cooling_dev = NULL;
1777                 return;
1778         }
1779
1780         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1781                  device->cooling_dev->id);
1782         result = sysfs_create_link(&device->dev->dev.kobj,
1783                         &device->cooling_dev->device.kobj,
1784                         "thermal_cooling");
1785         if (result)
1786                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1787         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1788                         &device->dev->dev.kobj, "device");
1789         if (result)
1790                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1791 }
1792
1793 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1794 {
1795         struct acpi_video_device *dev;
1796         union acpi_object *levels;
1797
1798         mutex_lock(&video->device_list_lock);
1799         list_for_each_entry(dev, &video->video_device_list, entry) {
1800                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1801                         kfree(levels);
1802         }
1803         mutex_unlock(&video->device_list_lock);
1804 }
1805
1806 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1807 {
1808         /*
1809          * Do not create backlight device for video output
1810          * device that is not in the enumerated list.
1811          */
1812         if (!acpi_video_device_in_dod(dev)) {
1813                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1814                 return false;
1815         }
1816
1817         if (only_lcd)
1818                 return dev->flags.lcd;
1819         return true;
1820 }
1821
1822 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1823 {
1824         struct acpi_video_device *dev;
1825
1826         if (video->backlight_registered)
1827                 return 0;
1828
1829         acpi_video_run_bcl_for_osi(video);
1830
1831         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1832                 return 0;
1833
1834         mutex_lock(&video->device_list_lock);
1835         list_for_each_entry(dev, &video->video_device_list, entry) {
1836                 if (acpi_video_should_register_backlight(dev))
1837                         acpi_video_dev_register_backlight(dev);
1838         }
1839         mutex_unlock(&video->device_list_lock);
1840
1841         video->backlight_registered = true;
1842
1843         video->pm_nb.notifier_call = acpi_video_resume;
1844         video->pm_nb.priority = 0;
1845         return register_pm_notifier(&video->pm_nb);
1846 }
1847
1848 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1849 {
1850         if (device->backlight) {
1851                 backlight_device_unregister(device->backlight);
1852                 device->backlight = NULL;
1853         }
1854         if (device->brightness) {
1855                 kfree(device->brightness->levels);
1856                 kfree(device->brightness);
1857                 device->brightness = NULL;
1858         }
1859         if (device->cooling_dev) {
1860                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1861                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1862                 thermal_cooling_device_unregister(device->cooling_dev);
1863                 device->cooling_dev = NULL;
1864         }
1865 }
1866
1867 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1868 {
1869         struct acpi_video_device *dev;
1870         int error;
1871
1872         if (!video->backlight_registered)
1873                 return 0;
1874
1875         error = unregister_pm_notifier(&video->pm_nb);
1876
1877         mutex_lock(&video->device_list_lock);
1878         list_for_each_entry(dev, &video->video_device_list, entry)
1879                 acpi_video_dev_unregister_backlight(dev);
1880         mutex_unlock(&video->device_list_lock);
1881
1882         video->backlight_registered = false;
1883
1884         return error;
1885 }
1886
1887 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1888 {
1889         acpi_status status;
1890         struct acpi_device *adev = device->dev;
1891
1892         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1893                                              acpi_video_device_notify, device);
1894         if (ACPI_FAILURE(status))
1895                 dev_err(&adev->dev, "Error installing notify handler\n");
1896         else
1897                 device->flags.notify = 1;
1898 }
1899
1900 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1901 {
1902         struct input_dev *input;
1903         struct acpi_video_device *dev;
1904         int error;
1905
1906         video->input = input = input_allocate_device();
1907         if (!input) {
1908                 error = -ENOMEM;
1909                 goto out;
1910         }
1911
1912         error = acpi_video_bus_start_devices(video);
1913         if (error)
1914                 goto err_free_input;
1915
1916         snprintf(video->phys, sizeof(video->phys),
1917                         "%s/video/input0", acpi_device_hid(video->device));
1918
1919         input->name = acpi_device_name(video->device);
1920         input->phys = video->phys;
1921         input->id.bustype = BUS_HOST;
1922         input->id.product = 0x06;
1923         input->dev.parent = &video->device->dev;
1924         input->evbit[0] = BIT(EV_KEY);
1925         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1926         set_bit(KEY_VIDEO_NEXT, input->keybit);
1927         set_bit(KEY_VIDEO_PREV, input->keybit);
1928         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1929         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1930         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1931         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1932         set_bit(KEY_DISPLAY_OFF, input->keybit);
1933
1934         error = input_register_device(input);
1935         if (error)
1936                 goto err_stop_dev;
1937
1938         mutex_lock(&video->device_list_lock);
1939         list_for_each_entry(dev, &video->video_device_list, entry)
1940                 acpi_video_dev_add_notify_handler(dev);
1941         mutex_unlock(&video->device_list_lock);
1942
1943         return 0;
1944
1945 err_stop_dev:
1946         acpi_video_bus_stop_devices(video);
1947 err_free_input:
1948         input_free_device(input);
1949         video->input = NULL;
1950 out:
1951         return error;
1952 }
1953
1954 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1955 {
1956         if (dev->flags.notify) {
1957                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1958                                            acpi_video_device_notify);
1959                 dev->flags.notify = 0;
1960         }
1961 }
1962
1963 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1964 {
1965         struct acpi_video_device *dev;
1966
1967         mutex_lock(&video->device_list_lock);
1968         list_for_each_entry(dev, &video->video_device_list, entry)
1969                 acpi_video_dev_remove_notify_handler(dev);
1970         mutex_unlock(&video->device_list_lock);
1971
1972         acpi_video_bus_stop_devices(video);
1973         input_unregister_device(video->input);
1974         video->input = NULL;
1975 }
1976
1977 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1978 {
1979         struct acpi_video_device *dev, *next;
1980
1981         mutex_lock(&video->device_list_lock);
1982         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1983                 list_del(&dev->entry);
1984                 kfree(dev);
1985         }
1986         mutex_unlock(&video->device_list_lock);
1987
1988         return 0;
1989 }
1990
1991 static int instance;
1992
1993 static int acpi_video_bus_add(struct acpi_device *device)
1994 {
1995         struct acpi_video_bus *video;
1996         int error;
1997         acpi_status status;
1998
1999         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2000                                 device->parent->handle, 1,
2001                                 acpi_video_bus_match, NULL,
2002                                 device, NULL);
2003         if (status == AE_ALREADY_EXISTS) {
2004                 printk(KERN_WARNING FW_BUG
2005                         "Duplicate ACPI video bus devices for the"
2006                         " same VGA controller, please try module "
2007                         "parameter \"video.allow_duplicates=1\""
2008                         "if the current driver doesn't work.\n");
2009                 if (!allow_duplicates)
2010                         return -ENODEV;
2011         }
2012
2013         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2014         if (!video)
2015                 return -ENOMEM;
2016
2017         /* a hack to fix the duplicate name "VID" problem on T61 */
2018         if (!strcmp(device->pnp.bus_id, "VID")) {
2019                 if (instance)
2020                         device->pnp.bus_id[3] = '0' + instance;
2021                 instance++;
2022         }
2023         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2024         if (!strcmp(device->pnp.bus_id, "VGA")) {
2025                 if (instance)
2026                         device->pnp.bus_id[3] = '0' + instance;
2027                 instance++;
2028         }
2029
2030         video->device = device;
2031         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2032         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2033         device->driver_data = video;
2034
2035         acpi_video_bus_find_cap(video);
2036         error = acpi_video_bus_check(video);
2037         if (error)
2038                 goto err_free_video;
2039
2040         mutex_init(&video->device_list_lock);
2041         INIT_LIST_HEAD(&video->video_device_list);
2042
2043         error = acpi_video_bus_get_devices(video, device);
2044         if (error)
2045                 goto err_put_video;
2046
2047         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2048                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2049                video->flags.multihead ? "yes" : "no",
2050                video->flags.rom ? "yes" : "no",
2051                video->flags.post ? "yes" : "no");
2052         mutex_lock(&video_list_lock);
2053         list_add_tail(&video->entry, &video_bus_head);
2054         mutex_unlock(&video_list_lock);
2055
2056         acpi_video_bus_register_backlight(video);
2057         acpi_video_bus_add_notify_handler(video);
2058
2059         return 0;
2060
2061 err_put_video:
2062         acpi_video_bus_put_devices(video);
2063         kfree(video->attached_array);
2064 err_free_video:
2065         kfree(video);
2066         device->driver_data = NULL;
2067
2068         return error;
2069 }
2070
2071 static int acpi_video_bus_remove(struct acpi_device *device)
2072 {
2073         struct acpi_video_bus *video = NULL;
2074
2075
2076         if (!device || !acpi_driver_data(device))
2077                 return -EINVAL;
2078
2079         video = acpi_driver_data(device);
2080
2081         acpi_video_bus_remove_notify_handler(video);
2082         acpi_video_bus_unregister_backlight(video);
2083         acpi_video_bus_put_devices(video);
2084
2085         mutex_lock(&video_list_lock);
2086         list_del(&video->entry);
2087         mutex_unlock(&video_list_lock);
2088
2089         kfree(video->attached_array);
2090         kfree(video);
2091
2092         return 0;
2093 }
2094
2095 static int __init is_i740(struct pci_dev *dev)
2096 {
2097         if (dev->device == 0x00D1)
2098                 return 1;
2099         if (dev->device == 0x7000)
2100                 return 1;
2101         return 0;
2102 }
2103
2104 static int __init intel_opregion_present(void)
2105 {
2106         int opregion = 0;
2107         struct pci_dev *dev = NULL;
2108         u32 address;
2109
2110         for_each_pci_dev(dev) {
2111                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2112                         continue;
2113                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2114                         continue;
2115                 /* We don't want to poke around undefined i740 registers */
2116                 if (is_i740(dev))
2117                         continue;
2118                 pci_read_config_dword(dev, 0xfc, &address);
2119                 if (!address)
2120                         continue;
2121                 opregion = 1;
2122         }
2123         return opregion;
2124 }
2125
2126 static bool dmi_is_desktop(void)
2127 {
2128         const char *chassis_type;
2129
2130         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2131         if (!chassis_type)
2132                 return false;
2133
2134         if (!strcmp(chassis_type, "3") || /*  3: Desktop */
2135             !strcmp(chassis_type, "4") || /*  4: Low Profile Desktop */
2136             !strcmp(chassis_type, "5") || /*  5: Pizza Box */
2137             !strcmp(chassis_type, "6") || /*  6: Mini Tower */
2138             !strcmp(chassis_type, "7") || /*  7: Tower */
2139             !strcmp(chassis_type, "11"))  /* 11: Main Server Chassis */
2140                 return true;
2141
2142         return false;
2143 }
2144
2145 int acpi_video_register(void)
2146 {
2147         int ret = 0;
2148
2149         mutex_lock(&register_count_mutex);
2150         if (register_count) {
2151                 /*
2152                  * if the function of acpi_video_register is already called,
2153                  * don't register the acpi_vide_bus again and return no error.
2154                  */
2155                 goto leave;
2156         }
2157
2158         /*
2159          * We're seeing a lot of bogus backlight interfaces on newer machines
2160          * without a LCD such as desktops, servers and HDMI sticks. Checking
2161          * the lcd flag fixes this, so enable this on any machines which are
2162          * win8 ready (where we also prefer the native backlight driver, so
2163          * normally the acpi_video code should not register there anyways).
2164          */
2165         if (only_lcd == -1) {
2166                 if (dmi_is_desktop() && acpi_osi_is_win8())
2167                         only_lcd = true;
2168                 else
2169                         only_lcd = false;
2170         }
2171
2172         dmi_check_system(video_dmi_table);
2173
2174         ret = acpi_bus_register_driver(&acpi_video_bus);
2175         if (ret)
2176                 goto leave;
2177
2178         /*
2179          * When the acpi_video_bus is loaded successfully, increase
2180          * the counter reference.
2181          */
2182         register_count = 1;
2183
2184 leave:
2185         mutex_unlock(&register_count_mutex);
2186         return ret;
2187 }
2188 EXPORT_SYMBOL(acpi_video_register);
2189
2190 void acpi_video_unregister(void)
2191 {
2192         mutex_lock(&register_count_mutex);
2193         if (register_count) {
2194                 acpi_bus_unregister_driver(&acpi_video_bus);
2195                 register_count = 0;
2196         }
2197         mutex_unlock(&register_count_mutex);
2198 }
2199 EXPORT_SYMBOL(acpi_video_unregister);
2200
2201 void acpi_video_unregister_backlight(void)
2202 {
2203         struct acpi_video_bus *video;
2204
2205         mutex_lock(&register_count_mutex);
2206         if (register_count) {
2207                 mutex_lock(&video_list_lock);
2208                 list_for_each_entry(video, &video_bus_head, entry)
2209                         acpi_video_bus_unregister_backlight(video);
2210                 mutex_unlock(&video_list_lock);
2211         }
2212         mutex_unlock(&register_count_mutex);
2213 }
2214
2215 bool acpi_video_handles_brightness_key_presses(void)
2216 {
2217         bool have_video_busses;
2218
2219         mutex_lock(&video_list_lock);
2220         have_video_busses = !list_empty(&video_bus_head);
2221         mutex_unlock(&video_list_lock);
2222
2223         return have_video_busses &&
2224                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2225 }
2226 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2227
2228 /*
2229  * This is kind of nasty. Hardware using Intel chipsets may require
2230  * the video opregion code to be run first in order to initialise
2231  * state before any ACPI video calls are made. To handle this we defer
2232  * registration of the video class until the opregion code has run.
2233  */
2234
2235 static int __init acpi_video_init(void)
2236 {
2237         /*
2238          * Let the module load even if ACPI is disabled (e.g. due to
2239          * a broken BIOS) so that i915.ko can still be loaded on such
2240          * old systems without an AcpiOpRegion.
2241          *
2242          * acpi_video_register() will report -ENODEV later as well due
2243          * to acpi_disabled when i915.ko tries to register itself afterwards.
2244          */
2245         if (acpi_disabled)
2246                 return 0;
2247
2248         if (intel_opregion_present())
2249                 return 0;
2250
2251         return acpi_video_register();
2252 }
2253
2254 static void __exit acpi_video_exit(void)
2255 {
2256         acpi_video_detect_exit();
2257         acpi_video_unregister();
2258
2259         return;
2260 }
2261
2262 module_init(acpi_video_init);
2263 module_exit(acpi_video_exit);