drivers/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  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/list.h>
  32 #include <linux/mutex.h>
  33 #include <linux/input.h>
  34 #include <linux/backlight.h>
  35 #include <linux/thermal.h>
  36 #include <linux/sort.h>
  37 #include <linux/pci.h>
  38 #include <linux/pci_ids.h>
  39 #include <linux/slab.h>
  40 #include <asm/uaccess.h>
  41 #include <linux/dmi.h>
  42 #include <acpi/acpi_bus.h>
  43 #include <acpi/acpi_drivers.h>
  44 #include <linux/suspend.h>
  45 #include <acpi/video.h>
  46
  47 #include "internal.h"
  48
  49 #define PREFIX "ACPI: "
  50
  51 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
  52 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  53 #define ACPI_VIDEO_NOTIFY_SWITCH        0x80
  54 #define ACPI_VIDEO_NOTIFY_PROBE         0x81
  55 #define ACPI_VIDEO_NOTIFY_CYCLE         0x82
  56 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT   0x83
  57 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT   0x84
  58
  59 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS      0x85
  60 #define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS        0x86
  61 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS        0x87
  62 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS       0x88
  63 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF           0x89
  64
  65 #define MAX_NAME_LEN    20
  66
  67 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  68 ACPI_MODULE_NAME("video");
  69
  70 MODULE_AUTHOR("Bruno Ducrot");
  71 MODULE_DESCRIPTION("ACPI Video Driver");
  72 MODULE_LICENSE("GPL");
  73
  74 static bool brightness_switch_enabled = 1;
  75 module_param(brightness_switch_enabled, bool, 0644);
  76
  77 /*
  78  * By default, we don't allow duplicate ACPI video bus devices
  79  * under the same VGA controller
  80  */
  81 static bool allow_duplicates;
  82 module_param(allow_duplicates, bool, 0644);
  83
  84 /*
  85  * Some BIOSes claim they use minimum backlight at boot,
  86  * and this may bring dimming screen after boot
  87  */
  88 static bool use_bios_initial_backlight = 1;
  89 module_param(use_bios_initial_backlight, bool, 0644);
  90
  91 /*
  92  * For Windows 8 systems: if set ture and the GPU driver has
  93  * registered a backlight interface, skip registering ACPI video's.
  94  */
  95 static bool use_native_backlight = false;
  96 module_param(use_native_backlight, bool, 0644);
  97
  98 static int register_count;
  99 static struct mutex video_list_lock;
 100 static struct list_head video_bus_head;
 101 static int acpi_video_bus_add(struct acpi_device *device);
 102 static int acpi_video_bus_remove(struct acpi_device *device);
 103 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
 104
 105 static const struct acpi_device_id video_device_ids[] = {
 106         {ACPI_VIDEO_HID, 0},
 107         {"", 0},
 108 };
 109 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 110
 111 static struct acpi_driver acpi_video_bus = {
 112         .name = "video",
 113         .class = ACPI_VIDEO_CLASS,
 114         .ids = video_device_ids,
 115         .ops = {
 116                 .add = acpi_video_bus_add,
 117                 .remove = acpi_video_bus_remove,
 118                 .notify = acpi_video_bus_notify,
 119                 },
 120 };
 121
 122 struct acpi_video_bus_flags {
 123         u8 multihead:1;         /* can switch video heads */
 124         u8 rom:1;               /* can retrieve a video rom */
 125         u8 post:1;              /* can configure the head to */
 126         u8 reserved:5;
 127 };
 128
 129 struct acpi_video_bus_cap {
 130         u8 _DOS:1;              /* Enable/Disable output switching */
 131         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 132         u8 _ROM:1;              /* Get ROM Data */
 133         u8 _GPD:1;              /* Get POST Device */
 134         u8 _SPD:1;              /* Set POST Device */
 135         u8 _VPO:1;              /* Video POST Options */
 136         u8 reserved:2;
 137 };
 138
 139 struct acpi_video_device_attrib {
 140         u32 display_index:4;    /* A zero-based instance of the Display */
 141         u32 display_port_attachment:4;  /* This field differentiates the display type */
 142         u32 display_type:4;     /* Describe the specific type in use */
 143         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 144         u32 bios_can_detect:1;  /* BIOS can detect the device */
 145         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 146                                    the VGA device. */
 147         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 148         u32 reserved:10;        /* Must be 0 */
 149         u32 device_id_scheme:1; /* Device ID Scheme */
 150 };
 151
 152 struct acpi_video_enumerated_device {
 153         union {
 154                 u32 int_val;
 155                 struct acpi_video_device_attrib attrib;
 156         } value;
 157         struct acpi_video_device *bind_info;
 158 };
 159
 160 struct acpi_video_bus {
 161         struct acpi_device *device;
 162         u8 dos_setting;
 163         struct acpi_video_enumerated_device *attached_array;
 164         u8 attached_count;
 165         struct acpi_video_bus_cap cap;
 166         struct acpi_video_bus_flags flags;
 167         struct list_head video_device_list;
 168         struct mutex device_list_lock;  /* protects video_device_list */
 169         struct list_head entry;
 170         struct input_dev *input;
 171         char phys[32];  /* for input device */
 172         struct notifier_block pm_nb;
 173 };
 174
 175 struct acpi_video_device_flags {
 176         u8 crt:1;
 177         u8 lcd:1;
 178         u8 tvout:1;
 179         u8 dvi:1;
 180         u8 bios:1;
 181         u8 unknown:1;
 182         u8 notify:1;
 183         u8 reserved:1;
 184 };
 185
 186 struct acpi_video_device_cap {
 187         u8 _ADR:1;              /* Return the unique ID */
 188         u8 _BCL:1;              /* Query list of brightness control levels supported */
 189         u8 _BCM:1;              /* Set the brightness level */
 190         u8 _BQC:1;              /* Get current brightness level */
 191         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 192         u8 _DDC:1;              /* Return the EDID for this device */
 193 };
 194
 195 struct acpi_video_brightness_flags {
 196         u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */
 197         u8 _BCL_reversed:1;             /* _BCL package is in a reversed order */
 198         u8 _BQC_use_index:1;            /* _BQC returns an index value */
 199 };
 200
 201 struct acpi_video_device_brightness {
 202         int curr;
 203         int count;
 204         int *levels;
 205         struct acpi_video_brightness_flags flags;
 206 };
 207
 208 struct acpi_video_device {
 209         unsigned long device_id;
 210         struct acpi_video_device_flags flags;
 211         struct acpi_video_device_cap cap;
 212         struct list_head entry;
 213         struct acpi_video_bus *video;
 214         struct acpi_device *dev;
 215         struct acpi_video_device_brightness *brightness;
 216         struct backlight_device *backlight;
 217         struct thermal_cooling_device *cooling_dev;
 218 };
 219
 220 static const char device_decode[][30] = {
 221         "motherboard VGA device",
 222         "PCI VGA device",
 223         "AGP VGA device",
 224         "UNKNOWN",
 225 };
 226
 227 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 228 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 229 static void acpi_video_device_bind(struct acpi_video_bus *video,
 230                                    struct acpi_video_device *device);
 231 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 232 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 233                         int level);
 234 static int acpi_video_device_lcd_get_level_current(
 235                         struct acpi_video_device *device,
 236                         unsigned long long *level, bool raw);
 237 static int acpi_video_get_next_level(struct acpi_video_device *device,
 238                                      u32 level_current, u32 event);
 239 static int acpi_video_switch_brightness(struct acpi_video_device *device,
 240                                          int event);
 241
 242 static bool acpi_video_verify_backlight_support(void)
 243 {
 244         if (acpi_osi_is_win8() && use_native_backlight &&
 245             backlight_device_registered(BACKLIGHT_RAW))
 246                 return false;
 247         return acpi_video_backlight_support();
 248 }
 249
 250 /* backlight device sysfs support */
 251 static int acpi_video_get_brightness(struct backlight_device *bd)
 252 {
 253         unsigned long long cur_level;
 254         int i;
 255         struct acpi_video_device *vd = bl_get_data(bd);
 256
 257         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 258                 return -EINVAL;
 259         for (i = 2; i < vd->brightness->count; i++) {
 260                 if (vd->brightness->levels[i] == cur_level)
 261                         /*
 262                          * The first two entries are special - see page 575
 263                          * of the ACPI spec 3.0
 264                          */
 265                         return i - 2;
 266         }
 267         return 0;
 268 }
 269
 270 static int acpi_video_set_brightness(struct backlight_device *bd)
 271 {
 272         int request_level = bd->props.brightness + 2;
 273         struct acpi_video_device *vd = bl_get_data(bd);
 274
 275         return acpi_video_device_lcd_set_level(vd,
 276                                 vd->brightness->levels[request_level]);
 277 }
 278
 279 static const struct backlight_ops acpi_backlight_ops = {
 280         .get_brightness = acpi_video_get_brightness,
 281         .update_status  = acpi_video_set_brightness,
 282 };
 283
 284 /* thermal cooling device callbacks */
 285 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
 286                                long *state)
 287 {
 288         struct acpi_device *device = cooling_dev->devdata;
 289         struct acpi_video_device *video = acpi_driver_data(device);
 290
 291         *state = video->brightness->count - 3;
 292         return 0;
 293 }
 294
 295 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
 296                                long *state)
 297 {
 298         struct acpi_device *device = cooling_dev->devdata;
 299         struct acpi_video_device *video = acpi_driver_data(device);
 300         unsigned long long level;
 301         int offset;
 302
 303         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 304                 return -EINVAL;
 305         for (offset = 2; offset < video->brightness->count; offset++)
 306                 if (level == video->brightness->levels[offset]) {
 307                         *state = video->brightness->count - offset - 1;
 308                         return 0;
 309                 }
 310
 311         return -EINVAL;
 312 }
 313
 314 static int
 315 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 316 {
 317         struct acpi_device *device = cooling_dev->devdata;
 318         struct acpi_video_device *video = acpi_driver_data(device);
 319         int level;
 320
 321         if (state >= video->brightness->count - 2)
 322                 return -EINVAL;
 323
 324         state = video->brightness->count - state;
 325         level = video->brightness->levels[state - 1];
 326         return acpi_video_device_lcd_set_level(video, level);
 327 }
 328
 329 static const struct thermal_cooling_device_ops video_cooling_ops = {
 330         .get_max_state = video_get_max_state,
 331         .get_cur_state = video_get_cur_state,
 332         .set_cur_state = video_set_cur_state,
 333 };
 334
 335 /*
 336  * --------------------------------------------------------------------------
 337  *                             Video Management
 338  * --------------------------------------------------------------------------
 339  */
 340
 341 static int
 342 acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
 343                                    union acpi_object **levels)
 344 {
 345         int status;
 346         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 347         union acpi_object *obj;
 348
 349
 350         *levels = NULL;
 351
 352         status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
 353         if (!ACPI_SUCCESS(status))
 354                 return status;
 355         obj = (union acpi_object *)buffer.pointer;
 356         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 357                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 358                 status = -EFAULT;
 359                 goto err;
 360         }
 361
 362         *levels = obj;
 363
 364         return 0;
 365
 366 err:
 367         kfree(buffer.pointer);
 368
 369         return status;
 370 }
 371
 372 static int
 373 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 374 {
 375         int status;
 376         int state;
 377
 378         status = acpi_execute_simple_method(device->dev->handle,
 379                                             "_BCM", level);
 380         if (ACPI_FAILURE(status)) {
 381                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 382                 return -EIO;
 383         }
 384
 385         device->brightness->curr = level;
 386         for (state = 2; state < device->brightness->count; state++)
 387                 if (level == device->brightness->levels[state]) {
 388                         if (device->backlight)
 389                                 device->backlight->props.brightness = state - 2;
 390                         return 0;
 391                 }
 392
 393         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 394         return -EINVAL;
 395 }
 396
 397 /*
 398  * For some buggy _BQC methods, we need to add a constant value to
 399  * the _BQC return value to get the actual current brightness level
 400  */
 401
 402 static int bqc_offset_aml_bug_workaround;
 403 static int __init video_set_bqc_offset(const struct dmi_system_id *d)
 404 {
 405         bqc_offset_aml_bug_workaround = 9;
 406         return 0;
 407 }
 408
 409 static int video_ignore_initial_backlight(const struct dmi_system_id *d)
 410 {
 411         use_bios_initial_backlight = 0;
 412         return 0;
 413 }
 414
 415 static struct dmi_system_id video_dmi_table[] __initdata = {
 416         /*
 417          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 418          */
 419         {
 420          .callback = video_set_bqc_offset,
 421          .ident = "Acer Aspire 5720",
 422          .matches = {
 423                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 424                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 425                 },
 426         },
 427         {
 428          .callback = video_set_bqc_offset,
 429          .ident = "Acer Aspire 5710Z",
 430          .matches = {
 431                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 432                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 433                 },
 434         },
 435         {
 436          .callback = video_set_bqc_offset,
 437          .ident = "eMachines E510",
 438          .matches = {
 439                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 440                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 441                 },
 442         },
 443         {
 444          .callback = video_set_bqc_offset,
 445          .ident = "Acer Aspire 5315",
 446          .matches = {
 447                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 448                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 449                 },
 450         },
 451         {
 452          .callback = video_set_bqc_offset,
 453          .ident = "Acer Aspire 7720",
 454          .matches = {
 455                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 456                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 457                 },
 458         },
 459         {
 460          .callback = video_ignore_initial_backlight,
 461          .ident = "HP Folio 13-2000",
 462          .matches = {
 463                 DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
 464                 DMI_MATCH(DMI_PRODUCT_NAME, "HP Folio 13 - 2000 Notebook PC"),
 465                 },
 466         },
 467         {
 468          .callback = video_ignore_initial_backlight,
 469          .ident = "Fujitsu E753",
 470          .matches = {
 471                 DMI_MATCH(DMI_BOARD_VENDOR, "FUJITSU"),
 472                 DMI_MATCH(DMI_PRODUCT_NAME, "LIFEBOOK E753"),
 473                 },
 474         },
 475         {
 476          .callback = video_ignore_initial_backlight,
 477          .ident = "HP Pavilion dm4",
 478          .matches = {
 479                 DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
 480                 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion dm4 Notebook PC"),
 481                 },
 482         },
 483         {
 484          .callback = video_ignore_initial_backlight,
 485          .ident = "HP Pavilion g6 Notebook PC",
 486          .matches = {
 487                  DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
 488                  DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion g6 Notebook PC"),
 489                 },
 490         },
 491         {
 492          .callback = video_ignore_initial_backlight,
 493          .ident = "HP 1000 Notebook PC",
 494          .matches = {
 495                 DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
 496                 DMI_MATCH(DMI_PRODUCT_NAME, "HP 1000 Notebook PC"),
 497                 },
 498         },
 499         {
 500          .callback = video_ignore_initial_backlight,
 501          .ident = "HP Pavilion m4",
 502          .matches = {
 503                 DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
 504                 DMI_MATCH(DMI_PRODUCT_NAME, "HP Pavilion m4 Notebook PC"),
 505                 },
 506         },
 507         {}
 508 };
 509
 510 static unsigned long long
 511 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 512                               unsigned long long bqc_value)
 513 {
 514         unsigned long long level;
 515
 516         if (device->brightness->flags._BQC_use_index) {
 517                 /*
 518                  * _BQC returns an index that doesn't account for
 519                  * the first 2 items with special meaning, so we need
 520                  * to compensate for that by offsetting ourselves
 521                  */
 522                 if (device->brightness->flags._BCL_reversed)
 523                         bqc_value = device->brightness->count - 3 - bqc_value;
 524
 525                 level = device->brightness->levels[bqc_value + 2];
 526         } else {
 527                 level = bqc_value;
 528         }
 529
 530         level += bqc_offset_aml_bug_workaround;
 531
 532         return level;
 533 }
 534
 535 static int
 536 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 537                                         unsigned long long *level, bool raw)
 538 {
 539         acpi_status status = AE_OK;
 540         int i;
 541
 542         if (device->cap._BQC || device->cap._BCQ) {
 543                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 544
 545                 status = acpi_evaluate_integer(device->dev->handle, buf,
 546                                                 NULL, level);
 547                 if (ACPI_SUCCESS(status)) {
 548                         if (raw) {
 549                                 /*
 550                                  * Caller has indicated he wants the raw
 551                                  * value returned by _BQC, so don't furtherly
 552                                  * mess with the value.
 553                                  */
 554                                 return 0;
 555                         }
 556
 557                         *level = acpi_video_bqc_value_to_level(device, *level);
 558
 559                         for (i = 2; i < device->brightness->count; i++)
 560                                 if (device->brightness->levels[i] == *level) {
 561                                         device->brightness->curr = *level;
 562                                         return 0;
 563                                 }
 564                         /*
 565                          * BQC returned an invalid level.
 566                          * Stop using it.
 567                          */
 568                         ACPI_WARNING((AE_INFO,
 569                                       "%s returned an invalid level",
 570                                       buf));
 571                         device->cap._BQC = device->cap._BCQ = 0;
 572                 } else {
 573                         /*
 574                          * Fixme:
 575                          * should we return an error or ignore this failure?
 576                          * dev->brightness->curr is a cached value which stores
 577                          * the correct current backlight level in most cases.
 578                          * ACPI video backlight still works w/ buggy _BQC.
 579                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 580                          */
 581                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 582                         device->cap._BQC = device->cap._BCQ = 0;
 583                 }
 584         }
 585
 586         *level = device->brightness->curr;
 587         return 0;
 588 }
 589
 590 static int
 591 acpi_video_device_EDID(struct acpi_video_device *device,
 592                        union acpi_object **edid, ssize_t length)
 593 {
 594         int status;
 595         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 596         union acpi_object *obj;
 597         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 598         struct acpi_object_list args = { 1, &arg0 };
 599
 600
 601         *edid = NULL;
 602
 603         if (!device)
 604                 return -ENODEV;
 605         if (length == 128)
 606                 arg0.integer.value = 1;
 607         else if (length == 256)
 608                 arg0.integer.value = 2;
 609         else
 610                 return -EINVAL;
 611
 612         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 613         if (ACPI_FAILURE(status))
 614                 return -ENODEV;
 615
 616         obj = buffer.pointer;
 617
 618         if (obj && obj->type == ACPI_TYPE_BUFFER)
 619                 *edid = obj;
 620         else {
 621                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 622                 status = -EFAULT;
 623                 kfree(obj);
 624         }
 625
 626         return status;
 627 }
 628
 629 /* bus */
 630
 631 /*
 632  *  Arg:
 633  *      video           : video bus device pointer
 634  *      bios_flag       :
 635  *              0.      The system BIOS should NOT automatically switch(toggle)
 636  *                      the active display output.
 637  *              1.      The system BIOS should automatically switch (toggle) the
 638  *                      active display output. No switch event.
 639  *              2.      The _DGS value should be locked.
 640  *              3.      The system BIOS should not automatically switch (toggle) the
 641  *                      active display output, but instead generate the display switch
 642  *                      event notify code.
 643  *      lcd_flag        :
 644  *              0.      The system BIOS should automatically control the brightness level
 645  *                      of the LCD when the power changes from AC to DC
 646  *              1.      The system BIOS should NOT automatically control the brightness
 647  *                      level of the LCD when the power changes from AC to DC.
 648  *  Return Value:
 649  *              -EINVAL wrong arg.
 650  */
 651
 652 static int
 653 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 654 {
 655         acpi_status status;
 656
 657         if (!video->cap._DOS)
 658                 return 0;
 659
 660         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 661                 return -EINVAL;
 662         video->dos_setting = (lcd_flag << 2) | bios_flag;
 663         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 664                                             (lcd_flag << 2) | bios_flag);
 665         if (ACPI_FAILURE(status))
 666                 return -EIO;
 667
 668         return 0;
 669 }
 670
 671 /*
 672  * Simple comparison function used to sort backlight levels.
 673  */
 674
 675 static int
 676 acpi_video_cmp_level(const void *a, const void *b)
 677 {
 678         return *(int *)a - *(int *)b;
 679 }
 680
 681 /*
 682  * Decides if _BQC/_BCQ for this system is usable
 683  *
 684  * We do this by changing the level first and then read out the current
 685  * brightness level, if the value does not match, find out if it is using
 686  * index. If not, clear the _BQC/_BCQ capability.
 687  */
 688 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 689                                 int max_level, int current_level)
 690 {
 691         struct acpi_video_device_brightness *br = device->brightness;
 692         int result;
 693         unsigned long long level;
 694         int test_level;
 695
 696         /* don't mess with existing known broken systems */
 697         if (bqc_offset_aml_bug_workaround)
 698                 return 0;
 699
 700         /*
 701          * Some systems always report current brightness level as maximum
 702          * through _BQC, we need to test another value for them.
 703          */
 704         test_level = current_level == max_level ? br->levels[3] : max_level;
 705
 706         result = acpi_video_device_lcd_set_level(device, test_level);
 707         if (result)
 708                 return result;
 709
 710         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 711         if (result)
 712                 return result;
 713
 714         if (level != test_level) {
 715                 /* buggy _BQC found, need to find out if it uses index */
 716                 if (level < br->count) {
 717                         if (br->flags._BCL_reversed)
 718                                 level = br->count - 3 - level;
 719                         if (br->levels[level + 2] == test_level)
 720                                 br->flags._BQC_use_index = 1;
 721                 }
 722
 723                 if (!br->flags._BQC_use_index)
 724                         device->cap._BQC = device->cap._BCQ = 0;
 725         }
 726
 727         return 0;
 728 }
 729
 730
 731 /*
 732  *  Arg:
 733  *      device  : video output device (LCD, CRT, ..)
 734  *
 735  *  Return Value:
 736  *      Maximum brightness level
 737  *
 738  *  Allocate and initialize device->brightness.
 739  */
 740
 741 static int
 742 acpi_video_init_brightness(struct acpi_video_device *device)
 743 {
 744         union acpi_object *obj = NULL;
 745         int i, max_level = 0, count = 0, level_ac_battery = 0;
 746         unsigned long long level, level_old;
 747         union acpi_object *o;
 748         struct acpi_video_device_brightness *br = NULL;
 749         int result = -EINVAL;
 750
 751         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
 752                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 753                                                 "LCD brightness level\n"));
 754                 goto out;
 755         }
 756
 757         if (obj->package.count < 2)
 758                 goto out;
 759
 760         br = kzalloc(sizeof(*br), GFP_KERNEL);
 761         if (!br) {
 762                 printk(KERN_ERR "can't allocate memory\n");
 763                 result = -ENOMEM;
 764                 goto out;
 765         }
 766
 767         br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
 768                                 GFP_KERNEL);
 769         if (!br->levels) {
 770                 result = -ENOMEM;
 771                 goto out_free;
 772         }
 773
 774         for (i = 0; i < obj->package.count; i++) {
 775                 o = (union acpi_object *)&obj->package.elements[i];
 776                 if (o->type != ACPI_TYPE_INTEGER) {
 777                         printk(KERN_ERR PREFIX "Invalid data\n");
 778                         continue;
 779                 }
 780                 br->levels[count] = (u32) o->integer.value;
 781
 782                 if (br->levels[count] > max_level)
 783                         max_level = br->levels[count];
 784                 count++;
 785         }
 786
 787         /*
 788          * some buggy BIOS don't export the levels
 789          * when machine is on AC/Battery in _BCL package.
 790          * In this case, the first two elements in _BCL packages
 791          * are also supported brightness levels that OS should take care of.
 792          */
 793         for (i = 2; i < count; i++) {
 794                 if (br->levels[i] == br->levels[0])
 795                         level_ac_battery++;
 796                 if (br->levels[i] == br->levels[1])
 797                         level_ac_battery++;
 798         }
 799
 800         if (level_ac_battery < 2) {
 801                 level_ac_battery = 2 - level_ac_battery;
 802                 br->flags._BCL_no_ac_battery_levels = 1;
 803                 for (i = (count - 1 + level_ac_battery); i >= 2; i--)
 804                         br->levels[i] = br->levels[i - level_ac_battery];
 805                 count += level_ac_battery;
 806         } else if (level_ac_battery > 2)
 807                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 808
 809         /* Check if the _BCL package is in a reversed order */
 810         if (max_level == br->levels[2]) {
 811                 br->flags._BCL_reversed = 1;
 812                 sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
 813                         acpi_video_cmp_level, NULL);
 814         } else if (max_level != br->levels[count - 1])
 815                 ACPI_ERROR((AE_INFO,
 816                             "Found unordered _BCL package"));
 817
 818         br->count = count;
 819         device->brightness = br;
 820
 821         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 822         br->curr = level = max_level;
 823
 824         if (!device->cap._BQC)
 825                 goto set_level;
 826
 827         result = acpi_video_device_lcd_get_level_current(device,
 828                                                          &level_old, true);
 829         if (result)
 830                 goto out_free_levels;
 831
 832         result = acpi_video_bqc_quirk(device, max_level, level_old);
 833         if (result)
 834                 goto out_free_levels;
 835         /*
 836          * cap._BQC may get cleared due to _BQC is found to be broken
 837          * in acpi_video_bqc_quirk, so check again here.
 838          */
 839         if (!device->cap._BQC)
 840                 goto set_level;
 841
 842         if (use_bios_initial_backlight) {
 843                 level = acpi_video_bqc_value_to_level(device, level_old);
 844                 /*
 845                  * On some buggy laptops, _BQC returns an uninitialized
 846                  * value when invoked for the first time, i.e.
 847                  * level_old is invalid (no matter whether it's a level
 848                  * or an index). Set the backlight to max_level in this case.
 849                  */
 850                 for (i = 2; i < br->count; i++)
 851                         if (level_old == br->levels[i])
 852                                 break;
 853                 if (i == br->count)
 854                         level = max_level;
 855         }
 856
 857 set_level:
 858         result = acpi_video_device_lcd_set_level(device, level);
 859         if (result)
 860                 goto out_free_levels;
 861
 862         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 863                           "found %d brightness levels\n", count - 2));
 864         kfree(obj);
 865         return result;
 866
 867 out_free_levels:
 868         kfree(br->levels);
 869 out_free:
 870         kfree(br);
 871 out:
 872         device->brightness = NULL;
 873         kfree(obj);
 874         return result;
 875 }
 876
 877 /*
 878  *  Arg:
 879  *      device  : video output device (LCD, CRT, ..)
 880  *
 881  *  Return Value:
 882  *      None
 883  *
 884  *  Find out all required AML methods defined under the output
 885  *  device.
 886  */
 887
 888 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 889 {
 890         if (acpi_has_method(device->dev->handle, "_ADR"))
 891                 device->cap._ADR = 1;
 892         if (acpi_has_method(device->dev->handle, "_BCL"))
 893                 device->cap._BCL = 1;
 894         if (acpi_has_method(device->dev->handle, "_BCM"))
 895                 device->cap._BCM = 1;
 896         if (acpi_has_method(device->dev->handle, "_BQC")) {
 897                 device->cap._BQC = 1;
 898         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 899                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 900                 device->cap._BCQ = 1;
 901         }
 902
 903         if (acpi_has_method(device->dev->handle, "_DDC"))
 904                 device->cap._DDC = 1;
 905 }
 906
 907 /*
 908  *  Arg:
 909  *      device  : video output device (VGA)
 910  *
 911  *  Return Value:
 912  *      None
 913  *
 914  *  Find out all required AML methods defined under the video bus device.
 915  */
 916
 917 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 918 {
 919         if (acpi_has_method(video->device->handle, "_DOS"))
 920                 video->cap._DOS = 1;
 921         if (acpi_has_method(video->device->handle, "_DOD"))
 922                 video->cap._DOD = 1;
 923         if (acpi_has_method(video->device->handle, "_ROM"))
 924                 video->cap._ROM = 1;
 925         if (acpi_has_method(video->device->handle, "_GPD"))
 926                 video->cap._GPD = 1;
 927         if (acpi_has_method(video->device->handle, "_SPD"))
 928                 video->cap._SPD = 1;
 929         if (acpi_has_method(video->device->handle, "_VPO"))
 930                 video->cap._VPO = 1;
 931 }
 932
 933 /*
 934  * Check whether the video bus device has required AML method to
 935  * support the desired features
 936  */
 937
 938 static int acpi_video_bus_check(struct acpi_video_bus *video)
 939 {
 940         acpi_status status = -ENOENT;
 941         struct pci_dev *dev;
 942
 943         if (!video)
 944                 return -EINVAL;
 945
 946         dev = acpi_get_pci_dev(video->device->handle);
 947         if (!dev)
 948                 return -ENODEV;
 949         pci_dev_put(dev);
 950
 951         /*
 952          * Since there is no HID, CID and so on for VGA driver, we have
 953          * to check well known required nodes.
 954          */
 955
 956         /* Does this device support video switching? */
 957         if (video->cap._DOS || video->cap._DOD) {
 958                 if (!video->cap._DOS) {
 959                         printk(KERN_WARNING FW_BUG
 960                                 "ACPI(%s) defines _DOD but not _DOS\n",
 961                                 acpi_device_bid(video->device));
 962                 }
 963                 video->flags.multihead = 1;
 964                 status = 0;
 965         }
 966
 967         /* Does this device support retrieving a video ROM? */
 968         if (video->cap._ROM) {
 969                 video->flags.rom = 1;
 970                 status = 0;
 971         }
 972
 973         /* Does this device support configuring which video device to POST? */
 974         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
 975                 video->flags.post = 1;
 976                 status = 0;
 977         }
 978
 979         return status;
 980 }
 981
 982 /*
 983  * --------------------------------------------------------------------------
 984  *                               Driver Interface
 985  * --------------------------------------------------------------------------
 986  */
 987
 988 /* device interface */
 989 static struct acpi_video_device_attrib *
 990 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
 991 {
 992         struct acpi_video_enumerated_device *ids;
 993         int i;
 994
 995         for (i = 0; i < video->attached_count; i++) {
 996                 ids = &video->attached_array[i];
 997                 if ((ids->value.int_val & 0xffff) == device_id)
 998                         return &ids->value.attrib;
 999         }
1000
1001         return NULL;
1002 }
1003
1004 static int
1005 acpi_video_get_device_type(struct acpi_video_bus *video,
1006                            unsigned long device_id)
1007 {
1008         struct acpi_video_enumerated_device *ids;
1009         int i;
1010
1011         for (i = 0; i < video->attached_count; i++) {
1012                 ids = &video->attached_array[i];
1013                 if ((ids->value.int_val & 0xffff) == device_id)
1014                         return ids->value.int_val;
1015         }
1016
1017         return 0;
1018 }
1019
1020 static int
1021 acpi_video_bus_get_one_device(struct acpi_device *device,
1022                               struct acpi_video_bus *video)
1023 {
1024         unsigned long long device_id;
1025         int status, device_type;
1026         struct acpi_video_device *data;
1027         struct acpi_video_device_attrib *attribute;
1028
1029         status =
1030             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1031         /* Some device omits _ADR, we skip them instead of fail */
1032         if (ACPI_FAILURE(status))
1033                 return 0;
1034
1035         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1036         if (!data)
1037                 return -ENOMEM;
1038
1039         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1040         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1041         device->driver_data = data;
1042
1043         data->device_id = device_id;
1044         data->video = video;
1045         data->dev = device;
1046
1047         attribute = acpi_video_get_device_attr(video, device_id);
1048
1049         if (attribute && attribute->device_id_scheme) {
1050                 switch (attribute->display_type) {
1051                 case ACPI_VIDEO_DISPLAY_CRT:
1052                         data->flags.crt = 1;
1053                         break;
1054                 case ACPI_VIDEO_DISPLAY_TV:
1055                         data->flags.tvout = 1;
1056                         break;
1057                 case ACPI_VIDEO_DISPLAY_DVI:
1058                         data->flags.dvi = 1;
1059                         break;
1060                 case ACPI_VIDEO_DISPLAY_LCD:
1061                         data->flags.lcd = 1;
1062                         break;
1063                 default:
1064                         data->flags.unknown = 1;
1065                         break;
1066                 }
1067                 if (attribute->bios_can_detect)
1068                         data->flags.bios = 1;
1069         } else {
1070                 /* Check for legacy IDs */
1071                 device_type = acpi_video_get_device_type(video, device_id);
1072                 /* Ignore bits 16 and 18-20 */
1073                 switch (device_type & 0xffe2ffff) {
1074                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1075                         data->flags.crt = 1;
1076                         break;
1077                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1078                         data->flags.lcd = 1;
1079                         break;
1080                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1081                         data->flags.tvout = 1;
1082                         break;
1083                 default:
1084                         data->flags.unknown = 1;
1085                 }
1086         }
1087
1088         acpi_video_device_bind(video, data);
1089         acpi_video_device_find_cap(data);
1090
1091         mutex_lock(&video->device_list_lock);
1092         list_add_tail(&data->entry, &video->video_device_list);
1093         mutex_unlock(&video->device_list_lock);
1094
1095         return status;
1096 }
1097
1098 /*
1099  *  Arg:
1100  *      video   : video bus device
1101  *
1102  *  Return:
1103  *      none
1104  *
1105  *  Enumerate the video device list of the video bus,
1106  *  bind the ids with the corresponding video devices
1107  *  under the video bus.
1108  */
1109
1110 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1111 {
1112         struct acpi_video_device *dev;
1113
1114         mutex_lock(&video->device_list_lock);
1115
1116         list_for_each_entry(dev, &video->video_device_list, entry)
1117                 acpi_video_device_bind(video, dev);
1118
1119         mutex_unlock(&video->device_list_lock);
1120 }
1121
1122 /*
1123  *  Arg:
1124  *      video   : video bus device
1125  *      device  : video output device under the video
1126  *              bus
1127  *
1128  *  Return:
1129  *      none
1130  *
1131  *  Bind the ids with the corresponding video devices
1132  *  under the video bus.
1133  */
1134
1135 static void
1136 acpi_video_device_bind(struct acpi_video_bus *video,
1137                        struct acpi_video_device *device)
1138 {
1139         struct acpi_video_enumerated_device *ids;
1140         int i;
1141
1142         for (i = 0; i < video->attached_count; i++) {
1143                 ids = &video->attached_array[i];
1144                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1145                         ids->bind_info = device;
1146                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1147                 }
1148         }
1149 }
1150
1151 /*
1152  *  Arg:
1153  *      video   : video bus device
1154  *
1155  *  Return:
1156  *      < 0     : error
1157  *
1158  *  Call _DOD to enumerate all devices attached to display adapter
1159  *
1160  */
1161
1162 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1163 {
1164         int status;
1165         int count;
1166         int i;
1167         struct acpi_video_enumerated_device *active_list;
1168         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1169         union acpi_object *dod = NULL;
1170         union acpi_object *obj;
1171
1172         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1173         if (!ACPI_SUCCESS(status)) {
1174                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1175                 return status;
1176         }
1177
1178         dod = buffer.pointer;
1179         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1180                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1181                 status = -EFAULT;
1182                 goto out;
1183         }
1184
1185         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1186                           dod->package.count));
1187
1188         active_list = kcalloc(1 + dod->package.count,
1189                               sizeof(struct acpi_video_enumerated_device),
1190                               GFP_KERNEL);
1191         if (!active_list) {
1192                 status = -ENOMEM;
1193                 goto out;
1194         }
1195
1196         count = 0;
1197         for (i = 0; i < dod->package.count; i++) {
1198                 obj = &dod->package.elements[i];
1199
1200                 if (obj->type != ACPI_TYPE_INTEGER) {
1201                         printk(KERN_ERR PREFIX
1202                                 "Invalid _DOD data in element %d\n", i);
1203                         continue;
1204                 }
1205
1206                 active_list[count].value.int_val = obj->integer.value;
1207                 active_list[count].bind_info = NULL;
1208                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1209                                   (int)obj->integer.value));
1210                 count++;
1211         }
1212
1213         kfree(video->attached_array);
1214
1215         video->attached_array = active_list;
1216         video->attached_count = count;
1217
1218 out:
1219         kfree(buffer.pointer);
1220         return status;
1221 }
1222
1223 static int
1224 acpi_video_get_next_level(struct acpi_video_device *device,
1225                           u32 level_current, u32 event)
1226 {
1227         int min, max, min_above, max_below, i, l, delta = 255;
1228         max = max_below = 0;
1229         min = min_above = 255;
1230         /* Find closest level to level_current */
1231         for (i = 2; i < device->brightness->count; i++) {
1232                 l = device->brightness->levels[i];
1233                 if (abs(l - level_current) < abs(delta)) {
1234                         delta = l - level_current;
1235                         if (!delta)
1236                                 break;
1237                 }
1238         }
1239         /* Ajust level_current to closest available level */
1240         level_current += delta;
1241         for (i = 2; i < device->brightness->count; i++) {
1242                 l = device->brightness->levels[i];
1243                 if (l < min)
1244                         min = l;
1245                 if (l > max)
1246                         max = l;
1247                 if (l < min_above && l > level_current)
1248                         min_above = l;
1249                 if (l > max_below && l < level_current)
1250                         max_below = l;
1251         }
1252
1253         switch (event) {
1254         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1255                 return (level_current < max) ? min_above : min;
1256         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1257                 return (level_current < max) ? min_above : max;
1258         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1259                 return (level_current > min) ? max_below : min;
1260         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1261         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1262                 return 0;
1263         default:
1264                 return level_current;
1265         }
1266 }
1267
1268 static int
1269 acpi_video_switch_brightness(struct acpi_video_device *device, int event)
1270 {
1271         unsigned long long level_current, level_next;
1272         int result = -EINVAL;
1273
1274         /* no warning message if acpi_backlight=vendor or a quirk is used */
1275         if (!acpi_video_verify_backlight_support())
1276                 return 0;
1277
1278         if (!device->brightness)
1279                 goto out;
1280
1281         result = acpi_video_device_lcd_get_level_current(device,
1282                                                          &level_current,
1283                                                          false);
1284         if (result)
1285                 goto out;
1286
1287         level_next = acpi_video_get_next_level(device, level_current, event);
1288
1289         result = acpi_video_device_lcd_set_level(device, level_next);
1290
1291         if (!result)
1292                 backlight_force_update(device->backlight,
1293                                        BACKLIGHT_UPDATE_HOTKEY);
1294
1295 out:
1296         if (result)
1297                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1298
1299         return result;
1300 }
1301
1302 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1303                         void **edid)
1304 {
1305         struct acpi_video_bus *video;
1306         struct acpi_video_device *video_device;
1307         union acpi_object *buffer = NULL;
1308         acpi_status status;
1309         int i, length;
1310
1311         if (!device || !acpi_driver_data(device))
1312                 return -EINVAL;
1313
1314         video = acpi_driver_data(device);
1315
1316         for (i = 0; i < video->attached_count; i++) {
1317                 video_device = video->attached_array[i].bind_info;
1318                 length = 256;
1319
1320                 if (!video_device)
1321                         continue;
1322
1323                 if (!video_device->cap._DDC)
1324                         continue;
1325
1326                 if (type) {
1327                         switch (type) {
1328                         case ACPI_VIDEO_DISPLAY_CRT:
1329                                 if (!video_device->flags.crt)
1330                                         continue;
1331                                 break;
1332                         case ACPI_VIDEO_DISPLAY_TV:
1333                                 if (!video_device->flags.tvout)
1334                                         continue;
1335                                 break;
1336                         case ACPI_VIDEO_DISPLAY_DVI:
1337                                 if (!video_device->flags.dvi)
1338                                         continue;
1339                                 break;
1340                         case ACPI_VIDEO_DISPLAY_LCD:
1341                                 if (!video_device->flags.lcd)
1342                                         continue;
1343                                 break;
1344                         }
1345                 } else if (video_device->device_id != device_id) {
1346                         continue;
1347                 }
1348
1349                 status = acpi_video_device_EDID(video_device, &buffer, length);
1350
1351                 if (ACPI_FAILURE(status) || !buffer ||
1352                     buffer->type != ACPI_TYPE_BUFFER) {
1353                         length = 128;
1354                         status = acpi_video_device_EDID(video_device, &buffer,
1355                                                         length);
1356                         if (ACPI_FAILURE(status) || !buffer ||
1357                             buffer->type != ACPI_TYPE_BUFFER) {
1358                                 continue;
1359                         }
1360                 }
1361
1362                 *edid = buffer->buffer.pointer;
1363                 return length;
1364         }
1365
1366         return -ENODEV;
1367 }
1368 EXPORT_SYMBOL(acpi_video_get_edid);
1369
1370 static int
1371 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1372                            struct acpi_device *device)
1373 {
1374         int status = 0;
1375         struct acpi_device *dev;
1376
1377         /*
1378          * There are systems where video module known to work fine regardless
1379          * of broken _DOD and ignoring returned value here doesn't cause
1380          * any issues later.
1381          */
1382         acpi_video_device_enumerate(video);
1383
1384         list_for_each_entry(dev, &device->children, node) {
1385
1386                 status = acpi_video_bus_get_one_device(dev, video);
1387                 if (status) {
1388                         dev_err(&dev->dev, "Can't attach device\n");
1389                         break;
1390                 }
1391         }
1392         return status;
1393 }
1394
1395 /* acpi_video interface */
1396
1397 /*
1398  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1399  * preform any automatic brightness change on receiving a notification.
1400  */
1401 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1402 {
1403         return acpi_video_bus_DOS(video, 0,
1404                                   acpi_osi_is_win8() ? 1 : 0);
1405 }
1406
1407 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1408 {
1409         return acpi_video_bus_DOS(video, 0,
1410                                   acpi_osi_is_win8() ? 0 : 1);
1411 }
1412
1413 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1414 {
1415         struct acpi_video_bus *video = acpi_driver_data(device);
1416         struct input_dev *input;
1417         int keycode = 0;
1418
1419         if (!video || !video->input)
1420                 return;
1421
1422         input = video->input;
1423
1424         switch (event) {
1425         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1426                                          * most likely via hotkey. */
1427                 keycode = KEY_SWITCHVIDEOMODE;
1428                 break;
1429
1430         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1431                                          * connector. */
1432                 acpi_video_device_enumerate(video);
1433                 acpi_video_device_rebind(video);
1434                 keycode = KEY_SWITCHVIDEOMODE;
1435                 break;
1436
1437         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1438                 keycode = KEY_SWITCHVIDEOMODE;
1439                 break;
1440         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1441                 keycode = KEY_VIDEO_NEXT;
1442                 break;
1443         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1444                 keycode = KEY_VIDEO_PREV;
1445                 break;
1446
1447         default:
1448                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1449                                   "Unsupported event [0x%x]\n", event));
1450                 break;
1451         }
1452
1453         if (acpi_notifier_call_chain(device, event, 0))
1454                 /* Something vetoed the keypress. */
1455                 keycode = 0;
1456
1457         if (keycode) {
1458                 input_report_key(input, keycode, 1);
1459                 input_sync(input);
1460                 input_report_key(input, keycode, 0);
1461                 input_sync(input);
1462         }
1463
1464         return;
1465 }
1466
1467 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1468 {
1469         struct acpi_video_device *video_device = data;
1470         struct acpi_device *device = NULL;
1471         struct acpi_video_bus *bus;
1472         struct input_dev *input;
1473         int keycode = 0;
1474
1475         if (!video_device)
1476                 return;
1477
1478         device = video_device->dev;
1479         bus = video_device->video;
1480         input = bus->input;
1481
1482         switch (event) {
1483         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1484                 if (brightness_switch_enabled)
1485                         acpi_video_switch_brightness(video_device, event);
1486                 keycode = KEY_BRIGHTNESS_CYCLE;
1487                 break;
1488         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1489                 if (brightness_switch_enabled)
1490                         acpi_video_switch_brightness(video_device, event);
1491                 keycode = KEY_BRIGHTNESSUP;
1492                 break;
1493         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1494                 if (brightness_switch_enabled)
1495                         acpi_video_switch_brightness(video_device, event);
1496                 keycode = KEY_BRIGHTNESSDOWN;
1497                 break;
1498         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1499                 if (brightness_switch_enabled)
1500                         acpi_video_switch_brightness(video_device, event);
1501                 keycode = KEY_BRIGHTNESS_ZERO;
1502                 break;
1503         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1504                 if (brightness_switch_enabled)
1505                         acpi_video_switch_brightness(video_device, event);
1506                 keycode = KEY_DISPLAY_OFF;
1507                 break;
1508         default:
1509                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1510                                   "Unsupported event [0x%x]\n", event));
1511                 break;
1512         }
1513
1514         acpi_notifier_call_chain(device, event, 0);
1515
1516         if (keycode) {
1517                 input_report_key(input, keycode, 1);
1518                 input_sync(input);
1519                 input_report_key(input, keycode, 0);
1520                 input_sync(input);
1521         }
1522
1523         return;
1524 }
1525
1526 static int acpi_video_resume(struct notifier_block *nb,
1527                                 unsigned long val, void *ign)
1528 {
1529         struct acpi_video_bus *video;
1530         struct acpi_video_device *video_device;
1531         int i;
1532
1533         switch (val) {
1534         case PM_HIBERNATION_PREPARE:
1535         case PM_SUSPEND_PREPARE:
1536         case PM_RESTORE_PREPARE:
1537                 return NOTIFY_DONE;
1538         }
1539
1540         video = container_of(nb, struct acpi_video_bus, pm_nb);
1541
1542         dev_info(&video->device->dev, "Restoring backlight state\n");
1543
1544         for (i = 0; i < video->attached_count; i++) {
1545                 video_device = video->attached_array[i].bind_info;
1546                 if (video_device && video_device->backlight)
1547                         acpi_video_set_brightness(video_device->backlight);
1548         }
1549
1550         return NOTIFY_OK;
1551 }
1552
1553 static acpi_status
1554 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1555                         void **return_value)
1556 {
1557         struct acpi_device *device = context;
1558         struct acpi_device *sibling;
1559         int result;
1560
1561         if (handle == device->handle)
1562                 return AE_CTRL_TERMINATE;
1563
1564         result = acpi_bus_get_device(handle, &sibling);
1565         if (result)
1566                 return AE_OK;
1567
1568         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1569                         return AE_ALREADY_EXISTS;
1570
1571         return AE_OK;
1572 }
1573
1574 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1575 {
1576         if (acpi_video_verify_backlight_support()) {
1577                 struct backlight_properties props;
1578                 struct pci_dev *pdev;
1579                 acpi_handle acpi_parent;
1580                 struct device *parent = NULL;
1581                 int result;
1582                 static int count;
1583                 char *name;
1584
1585                 result = acpi_video_init_brightness(device);
1586                 if (result)
1587                         return;
1588                 name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1589                 if (!name)
1590                         return;
1591                 count++;
1592
1593                 acpi_get_parent(device->dev->handle, &acpi_parent);
1594
1595                 pdev = acpi_get_pci_dev(acpi_parent);
1596                 if (pdev) {
1597                         parent = &pdev->dev;
1598                         pci_dev_put(pdev);
1599                 }
1600
1601                 memset(&props, 0, sizeof(struct backlight_properties));
1602                 props.type = BACKLIGHT_FIRMWARE;
1603                 props.max_brightness = device->brightness->count - 3;
1604                 device->backlight = backlight_device_register(name,
1605                                                               parent,
1606                                                               device,
1607                                                               &acpi_backlight_ops,
1608                                                               &props);
1609                 kfree(name);
1610                 if (IS_ERR(device->backlight))
1611                         return;
1612
1613                 /*
1614                  * Save current brightness level in case we have to restore it
1615                  * before acpi_video_device_lcd_set_level() is called next time.
1616                  */
1617                 device->backlight->props.brightness =
1618                                 acpi_video_get_brightness(device->backlight);
1619
1620                 device->cooling_dev = thermal_cooling_device_register("LCD",
1621                                         device->dev, &video_cooling_ops);
1622                 if (IS_ERR(device->cooling_dev)) {
1623                         /*
1624                          * Set cooling_dev to NULL so we don't crash trying to
1625                          * free it.
1626                          * Also, why the hell we are returning early and
1627                          * not attempt to register video output if cooling
1628                          * device registration failed?
1629                          * -- dtor
1630                          */
1631                         device->cooling_dev = NULL;
1632                         return;
1633                 }
1634
1635                 dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1636                          device->cooling_dev->id);
1637                 result = sysfs_create_link(&device->dev->dev.kobj,
1638                                 &device->cooling_dev->device.kobj,
1639                                 "thermal_cooling");
1640                 if (result)
1641                         printk(KERN_ERR PREFIX "Create sysfs link\n");
1642                 result = sysfs_create_link(&device->cooling_dev->device.kobj,
1643                                 &device->dev->dev.kobj, "device");
1644                 if (result)
1645                         printk(KERN_ERR PREFIX "Create sysfs link\n");
1646         }
1647 }
1648
1649 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1650 {
1651         struct acpi_video_device *dev;
1652
1653         mutex_lock(&video->device_list_lock);
1654         list_for_each_entry(dev, &video->video_device_list, entry)
1655                 acpi_video_dev_register_backlight(dev);
1656         mutex_unlock(&video->device_list_lock);
1657
1658         video->pm_nb.notifier_call = acpi_video_resume;
1659         video->pm_nb.priority = 0;
1660         return register_pm_notifier(&video->pm_nb);
1661 }
1662
1663 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1664 {
1665         if (device->backlight) {
1666                 backlight_device_unregister(device->backlight);
1667                 device->backlight = NULL;
1668         }
1669         if (device->brightness) {
1670                 kfree(device->brightness->levels);
1671                 kfree(device->brightness);
1672                 device->brightness = NULL;
1673         }
1674         if (device->cooling_dev) {
1675                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1676                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1677                 thermal_cooling_device_unregister(device->cooling_dev);
1678                 device->cooling_dev = NULL;
1679         }
1680 }
1681
1682 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1683 {
1684         struct acpi_video_device *dev;
1685         int error = unregister_pm_notifier(&video->pm_nb);
1686
1687         mutex_lock(&video->device_list_lock);
1688         list_for_each_entry(dev, &video->video_device_list, entry)
1689                 acpi_video_dev_unregister_backlight(dev);
1690         mutex_unlock(&video->device_list_lock);
1691
1692         return error;
1693 }
1694
1695 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1696 {
1697         acpi_status status;
1698         struct acpi_device *adev = device->dev;
1699
1700         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1701                                              acpi_video_device_notify, device);
1702         if (ACPI_FAILURE(status))
1703                 dev_err(&adev->dev, "Error installing notify handler\n");
1704         else
1705                 device->flags.notify = 1;
1706 }
1707
1708 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1709 {
1710         struct input_dev *input;
1711         struct acpi_video_device *dev;
1712         int error;
1713
1714         video->input = input = input_allocate_device();
1715         if (!input) {
1716                 error = -ENOMEM;
1717                 goto out;
1718         }
1719
1720         error = acpi_video_bus_start_devices(video);
1721         if (error)
1722                 goto err_free_input;
1723
1724         snprintf(video->phys, sizeof(video->phys),
1725                         "%s/video/input0", acpi_device_hid(video->device));
1726
1727         input->name = acpi_device_name(video->device);
1728         input->phys = video->phys;
1729         input->id.bustype = BUS_HOST;
1730         input->id.product = 0x06;
1731         input->dev.parent = &video->device->dev;
1732         input->evbit[0] = BIT(EV_KEY);
1733         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1734         set_bit(KEY_VIDEO_NEXT, input->keybit);
1735         set_bit(KEY_VIDEO_PREV, input->keybit);
1736         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1737         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1738         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1739         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1740         set_bit(KEY_DISPLAY_OFF, input->keybit);
1741
1742         error = input_register_device(input);
1743         if (error)
1744                 goto err_stop_dev;
1745
1746         mutex_lock(&video->device_list_lock);
1747         list_for_each_entry(dev, &video->video_device_list, entry)
1748                 acpi_video_dev_add_notify_handler(dev);
1749         mutex_unlock(&video->device_list_lock);
1750
1751         return 0;
1752
1753 err_stop_dev:
1754         acpi_video_bus_stop_devices(video);
1755 err_free_input:
1756         input_free_device(input);
1757         video->input = NULL;
1758 out:
1759         return error;
1760 }
1761
1762 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1763 {
1764         if (dev->flags.notify) {
1765                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1766                                            acpi_video_device_notify);
1767                 dev->flags.notify = 0;
1768         }
1769 }
1770
1771 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1772 {
1773         struct acpi_video_device *dev;
1774
1775         mutex_lock(&video->device_list_lock);
1776         list_for_each_entry(dev, &video->video_device_list, entry)
1777                 acpi_video_dev_remove_notify_handler(dev);
1778         mutex_unlock(&video->device_list_lock);
1779
1780         acpi_video_bus_stop_devices(video);
1781         input_unregister_device(video->input);
1782         video->input = NULL;
1783 }
1784
1785 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1786 {
1787         struct acpi_video_device *dev, *next;
1788
1789         mutex_lock(&video->device_list_lock);
1790         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1791                 list_del(&dev->entry);
1792                 kfree(dev);
1793         }
1794         mutex_unlock(&video->device_list_lock);
1795
1796         return 0;
1797 }
1798
1799 static int instance;
1800
1801 static int acpi_video_bus_add(struct acpi_device *device)
1802 {
1803         struct acpi_video_bus *video;
1804         int error;
1805         acpi_status status;
1806
1807         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1808                                 device->parent->handle, 1,
1809                                 acpi_video_bus_match, NULL,
1810                                 device, NULL);
1811         if (status == AE_ALREADY_EXISTS) {
1812                 printk(KERN_WARNING FW_BUG
1813                         "Duplicate ACPI video bus devices for the"
1814                         " same VGA controller, please try module "
1815                         "parameter \"video.allow_duplicates=1\""
1816                         "if the current driver doesn't work.\n");
1817                 if (!allow_duplicates)
1818                         return -ENODEV;
1819         }
1820
1821         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1822         if (!video)
1823                 return -ENOMEM;
1824
1825         /* a hack to fix the duplicate name "VID" problem on T61 */
1826         if (!strcmp(device->pnp.bus_id, "VID")) {
1827                 if (instance)
1828                         device->pnp.bus_id[3] = '0' + instance;
1829                 instance++;
1830         }
1831         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1832         if (!strcmp(device->pnp.bus_id, "VGA")) {
1833                 if (instance)
1834                         device->pnp.bus_id[3] = '0' + instance;
1835                 instance++;
1836         }
1837
1838         video->device = device;
1839         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1840         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1841         device->driver_data = video;
1842
1843         acpi_video_bus_find_cap(video);
1844         error = acpi_video_bus_check(video);
1845         if (error)
1846                 goto err_free_video;
1847
1848         mutex_init(&video->device_list_lock);
1849         INIT_LIST_HEAD(&video->video_device_list);
1850
1851         error = acpi_video_bus_get_devices(video, device);
1852         if (error)
1853                 goto err_put_video;
1854
1855         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1856                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1857                video->flags.multihead ? "yes" : "no",
1858                video->flags.rom ? "yes" : "no",
1859                video->flags.post ? "yes" : "no");
1860         mutex_lock(&video_list_lock);
1861         list_add_tail(&video->entry, &video_bus_head);
1862         mutex_unlock(&video_list_lock);
1863
1864         acpi_video_bus_register_backlight(video);
1865         acpi_video_bus_add_notify_handler(video);
1866
1867         return 0;
1868
1869 err_put_video:
1870         acpi_video_bus_put_devices(video);
1871         kfree(video->attached_array);
1872 err_free_video:
1873         kfree(video);
1874         device->driver_data = NULL;
1875
1876         return error;
1877 }
1878
1879 static int acpi_video_bus_remove(struct acpi_device *device)
1880 {
1881         struct acpi_video_bus *video = NULL;
1882
1883
1884         if (!device || !acpi_driver_data(device))
1885                 return -EINVAL;
1886
1887         video = acpi_driver_data(device);
1888
1889         acpi_video_bus_remove_notify_handler(video);
1890         acpi_video_bus_unregister_backlight(video);
1891         acpi_video_bus_put_devices(video);
1892
1893         mutex_lock(&video_list_lock);
1894         list_del(&video->entry);
1895         mutex_unlock(&video_list_lock);
1896
1897         kfree(video->attached_array);
1898         kfree(video);
1899
1900         return 0;
1901 }
1902
1903 static int __init is_i740(struct pci_dev *dev)
1904 {
1905         if (dev->device == 0x00D1)
1906                 return 1;
1907         if (dev->device == 0x7000)
1908                 return 1;
1909         return 0;
1910 }
1911
1912 static int __init intel_opregion_present(void)
1913 {
1914         int opregion = 0;
1915         struct pci_dev *dev = NULL;
1916         u32 address;
1917
1918         for_each_pci_dev(dev) {
1919                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
1920                         continue;
1921                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
1922                         continue;
1923                 /* We don't want to poke around undefined i740 registers */
1924                 if (is_i740(dev))
1925                         continue;
1926                 pci_read_config_dword(dev, 0xfc, &address);
1927                 if (!address)
1928                         continue;
1929                 opregion = 1;
1930         }
1931         return opregion;
1932 }
1933
1934 int acpi_video_register(void)
1935 {
1936         int result = 0;
1937         if (register_count) {
1938                 /*
1939                  * if the function of acpi_video_register is already called,
1940                  * don't register the acpi_vide_bus again and return no error.
1941                  */
1942                 return 0;
1943         }
1944
1945         mutex_init(&video_list_lock);
1946         INIT_LIST_HEAD(&video_bus_head);
1947
1948         result = acpi_bus_register_driver(&acpi_video_bus);
1949         if (result < 0)
1950                 return -ENODEV;
1951
1952         /*
1953          * When the acpi_video_bus is loaded successfully, increase
1954          * the counter reference.
1955          */
1956         register_count = 1;
1957
1958         return 0;
1959 }
1960 EXPORT_SYMBOL(acpi_video_register);
1961
1962 void acpi_video_unregister(void)
1963 {
1964         if (!register_count) {
1965                 /*
1966                  * If the acpi video bus is already unloaded, don't
1967                  * unload it again and return directly.
1968                  */
1969                 return;
1970         }
1971         acpi_bus_unregister_driver(&acpi_video_bus);
1972
1973         register_count = 0;
1974
1975         return;
1976 }
1977 EXPORT_SYMBOL(acpi_video_unregister);
1978
1979 /*
1980  * This is kind of nasty. Hardware using Intel chipsets may require
1981  * the video opregion code to be run first in order to initialise
1982  * state before any ACPI video calls are made. To handle this we defer
1983  * registration of the video class until the opregion code has run.
1984  */
1985
1986 static int __init acpi_video_init(void)
1987 {
1988         dmi_check_system(video_dmi_table);
1989
1990         if (intel_opregion_present())
1991                 return 0;
1992
1993         return acpi_video_register();
1994 }
1995
1996 static void __exit acpi_video_exit(void)
1997 {
1998         acpi_video_unregister();
1999
2000         return;
2001 }
2002
2003 module_init(acpi_video_init);
2004 module_exit(acpi_video_exit);