drivers/acpi/acpi_video.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  video.c - ACPI Video Driver
   4  *
   5  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   6  *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
   7  *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
   8  */
   9
  10 #define pr_fmt(fmt) "ACPI: video: " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/list.h>
  17 #include <linux/mutex.h>
  18 #include <linux/input.h>
  19 #include <linux/backlight.h>
  20 #include <linux/thermal.h>
  21 #include <linux/sort.h>
  22 #include <linux/pci.h>
  23 #include <linux/pci_ids.h>
  24 #include <linux/slab.h>
  25 #include <linux/dmi.h>
  26 #include <linux/suspend.h>
  27 #include <linux/acpi.h>
  28 #include <acpi/video.h>
  29 #include <linux/uaccess.h>
  30
  31 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
  32 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  33
  34 #define MAX_NAME_LEN    20
  35
  36 MODULE_AUTHOR("Bruno Ducrot");
  37 MODULE_DESCRIPTION("ACPI Video Driver");
  38 MODULE_LICENSE("GPL");
  39
  40 static bool brightness_switch_enabled = true;
  41 module_param(brightness_switch_enabled, bool, 0644);
  42
  43 /*
  44  * By default, we don't allow duplicate ACPI video bus devices
  45  * under the same VGA controller
  46  */
  47 static bool allow_duplicates;
  48 module_param(allow_duplicates, bool, 0644);
  49
  50 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  51 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  52 static int report_key_events = -1;
  53 module_param(report_key_events, int, 0644);
  54 MODULE_PARM_DESC(report_key_events,
  55         "0: none, 1: output changes, 2: brightness changes, 3: all");
  56
  57 static int hw_changes_brightness = -1;
  58 module_param(hw_changes_brightness, int, 0644);
  59 MODULE_PARM_DESC(hw_changes_brightness,
  60         "Set this to 1 on buggy hw which changes the brightness itself when "
  61         "a hotkey is pressed: -1: auto, 0: normal 1: hw-changes-brightness");
  62
  63 /*
  64  * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
  65  * assumed even if not actually set.
  66  */
  67 static bool device_id_scheme = false;
  68 module_param(device_id_scheme, bool, 0444);
  69
  70 static int only_lcd = -1;
  71 module_param(only_lcd, int, 0444);
  72
  73 static bool may_report_brightness_keys;
  74 static int register_count;
  75 static DEFINE_MUTEX(register_count_mutex);
  76 static DEFINE_MUTEX(video_list_lock);
  77 static LIST_HEAD(video_bus_head);
  78 static int acpi_video_bus_add(struct acpi_device *device);
  79 static void acpi_video_bus_remove(struct acpi_device *device);
  80 static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data);
  81
  82 /*
  83  * Indices in the _BCL method response: the first two items are special,
  84  * the rest are all supported levels.
  85  *
  86  * See page 575 of the ACPI spec 3.0
  87  */
  88 enum acpi_video_level_idx {
  89         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
  90         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
  91         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
  92 };
  93
  94 static const struct acpi_device_id video_device_ids[] = {
  95         {ACPI_VIDEO_HID, 0},
  96         {"", 0},
  97 };
  98 MODULE_DEVICE_TABLE(acpi, video_device_ids);
  99
 100 static struct acpi_driver acpi_video_bus = {
 101         .name = "video",
 102         .class = ACPI_VIDEO_CLASS,
 103         .ids = video_device_ids,
 104         .ops = {
 105                 .add = acpi_video_bus_add,
 106                 .remove = acpi_video_bus_remove,
 107                 },
 108 };
 109
 110 struct acpi_video_bus_flags {
 111         u8 multihead:1;         /* can switch video heads */
 112         u8 rom:1;               /* can retrieve a video rom */
 113         u8 post:1;              /* can configure the head to */
 114         u8 reserved:5;
 115 };
 116
 117 struct acpi_video_bus_cap {
 118         u8 _DOS:1;              /* Enable/Disable output switching */
 119         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 120         u8 _ROM:1;              /* Get ROM Data */
 121         u8 _GPD:1;              /* Get POST Device */
 122         u8 _SPD:1;              /* Set POST Device */
 123         u8 _VPO:1;              /* Video POST Options */
 124         u8 reserved:2;
 125 };
 126
 127 struct acpi_video_device_attrib {
 128         u32 display_index:4;    /* A zero-based instance of the Display */
 129         u32 display_port_attachment:4;  /* This field differentiates the display type */
 130         u32 display_type:4;     /* Describe the specific type in use */
 131         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 132         u32 bios_can_detect:1;  /* BIOS can detect the device */
 133         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 134                                    the VGA device. */
 135         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 136         u32 reserved:10;        /* Must be 0 */
 137
 138         /*
 139          * The device ID might not actually follow the scheme described by this
 140          * struct acpi_video_device_attrib. If it does, then this bit
 141          * device_id_scheme is set; otherwise, other fields should be ignored.
 142          *
 143          * (but also see the global flag device_id_scheme)
 144          */
 145         u32 device_id_scheme:1;
 146 };
 147
 148 struct acpi_video_enumerated_device {
 149         union {
 150                 u32 int_val;
 151                 struct acpi_video_device_attrib attrib;
 152         } value;
 153         struct acpi_video_device *bind_info;
 154 };
 155
 156 struct acpi_video_bus {
 157         struct acpi_device *device;
 158         bool backlight_registered;
 159         u8 dos_setting;
 160         struct acpi_video_enumerated_device *attached_array;
 161         u8 attached_count;
 162         u8 child_count;
 163         struct acpi_video_bus_cap cap;
 164         struct acpi_video_bus_flags flags;
 165         struct list_head video_device_list;
 166         struct mutex device_list_lock;  /* protects video_device_list */
 167         struct list_head entry;
 168         struct input_dev *input;
 169         char phys[32];  /* for input device */
 170         struct notifier_block pm_nb;
 171 };
 172
 173 struct acpi_video_device_flags {
 174         u8 crt:1;
 175         u8 lcd:1;
 176         u8 tvout:1;
 177         u8 dvi:1;
 178         u8 bios:1;
 179         u8 unknown:1;
 180         u8 notify:1;
 181         u8 reserved:1;
 182 };
 183
 184 struct acpi_video_device_cap {
 185         u8 _ADR:1;              /* Return the unique ID */
 186         u8 _BCL:1;              /* Query list of brightness control levels supported */
 187         u8 _BCM:1;              /* Set the brightness level */
 188         u8 _BQC:1;              /* Get current brightness level */
 189         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 190         u8 _DDC:1;              /* Return the EDID for this device */
 191 };
 192
 193 struct acpi_video_device {
 194         unsigned long device_id;
 195         struct acpi_video_device_flags flags;
 196         struct acpi_video_device_cap cap;
 197         struct list_head entry;
 198         struct delayed_work switch_brightness_work;
 199         int switch_brightness_event;
 200         struct acpi_video_bus *video;
 201         struct acpi_device *dev;
 202         struct acpi_video_device_brightness *brightness;
 203         struct backlight_device *backlight;
 204         struct thermal_cooling_device *cooling_dev;
 205 };
 206
 207 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 208 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 209 static void acpi_video_device_bind(struct acpi_video_bus *video,
 210                                    struct acpi_video_device *device);
 211 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 212 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 213                         int level);
 214 static int acpi_video_device_lcd_get_level_current(
 215                         struct acpi_video_device *device,
 216                         unsigned long long *level, bool raw);
 217 static int acpi_video_get_next_level(struct acpi_video_device *device,
 218                                      u32 level_current, u32 event);
 219 static void acpi_video_switch_brightness(struct work_struct *work);
 220
 221 /* backlight device sysfs support */
 222 static int acpi_video_get_brightness(struct backlight_device *bd)
 223 {
 224         unsigned long long cur_level;
 225         int i;
 226         struct acpi_video_device *vd = bl_get_data(bd);
 227
 228         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 229                 return -EINVAL;
 230         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 231                 if (vd->brightness->levels[i] == cur_level)
 232                         return i - ACPI_VIDEO_FIRST_LEVEL;
 233         }
 234         return 0;
 235 }
 236
 237 static int acpi_video_set_brightness(struct backlight_device *bd)
 238 {
 239         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 240         struct acpi_video_device *vd = bl_get_data(bd);
 241
 242         cancel_delayed_work(&vd->switch_brightness_work);
 243         return acpi_video_device_lcd_set_level(vd,
 244                                 vd->brightness->levels[request_level]);
 245 }
 246
 247 static const struct backlight_ops acpi_backlight_ops = {
 248         .get_brightness = acpi_video_get_brightness,
 249         .update_status  = acpi_video_set_brightness,
 250 };
 251
 252 /* thermal cooling device callbacks */
 253 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 254                                unsigned long *state)
 255 {
 256         struct acpi_device *device = cooling_dev->devdata;
 257         struct acpi_video_device *video = acpi_driver_data(device);
 258
 259         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 260         return 0;
 261 }
 262
 263 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 264                                unsigned long *state)
 265 {
 266         struct acpi_device *device = cooling_dev->devdata;
 267         struct acpi_video_device *video = acpi_driver_data(device);
 268         unsigned long long level;
 269         int offset;
 270
 271         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 272                 return -EINVAL;
 273         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 274              offset++)
 275                 if (level == video->brightness->levels[offset]) {
 276                         *state = video->brightness->count - offset - 1;
 277                         return 0;
 278                 }
 279
 280         return -EINVAL;
 281 }
 282
 283 static int
 284 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 285 {
 286         struct acpi_device *device = cooling_dev->devdata;
 287         struct acpi_video_device *video = acpi_driver_data(device);
 288         int level;
 289
 290         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 291                 return -EINVAL;
 292
 293         state = video->brightness->count - state;
 294         level = video->brightness->levels[state - 1];
 295         return acpi_video_device_lcd_set_level(video, level);
 296 }
 297
 298 static const struct thermal_cooling_device_ops video_cooling_ops = {
 299         .get_max_state = video_get_max_state,
 300         .get_cur_state = video_get_cur_state,
 301         .set_cur_state = video_set_cur_state,
 302 };
 303
 304 /*
 305  * --------------------------------------------------------------------------
 306  *                             Video Management
 307  * --------------------------------------------------------------------------
 308  */
 309
 310 static int
 311 acpi_video_device_lcd_query_levels(acpi_handle handle,
 312                                    union acpi_object **levels)
 313 {
 314         int status;
 315         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 316         union acpi_object *obj;
 317
 318
 319         *levels = NULL;
 320
 321         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 322         if (ACPI_FAILURE(status))
 323                 return status;
 324         obj = (union acpi_object *)buffer.pointer;
 325         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 326                 acpi_handle_info(handle, "Invalid _BCL data\n");
 327                 status = -EFAULT;
 328                 goto err;
 329         }
 330
 331         *levels = obj;
 332
 333         return 0;
 334
 335 err:
 336         kfree(buffer.pointer);
 337
 338         return status;
 339 }
 340
 341 static int
 342 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 343 {
 344         int status;
 345         int state;
 346
 347         status = acpi_execute_simple_method(device->dev->handle,
 348                                             "_BCM", level);
 349         if (ACPI_FAILURE(status)) {
 350                 acpi_handle_info(device->dev->handle, "_BCM evaluation failed\n");
 351                 return -EIO;
 352         }
 353
 354         device->brightness->curr = level;
 355         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 356              state++)
 357                 if (level == device->brightness->levels[state]) {
 358                         if (device->backlight)
 359                                 device->backlight->props.brightness =
 360                                         state - ACPI_VIDEO_FIRST_LEVEL;
 361                         return 0;
 362                 }
 363
 364         acpi_handle_info(device->dev->handle, "Current brightness invalid\n");
 365         return -EINVAL;
 366 }
 367
 368 /*
 369  * For some buggy _BQC methods, we need to add a constant value to
 370  * the _BQC return value to get the actual current brightness level
 371  */
 372
 373 static int bqc_offset_aml_bug_workaround;
 374 static int video_set_bqc_offset(const struct dmi_system_id *d)
 375 {
 376         bqc_offset_aml_bug_workaround = 9;
 377         return 0;
 378 }
 379
 380 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 381 {
 382         device_id_scheme = true;
 383         return 0;
 384 }
 385
 386 static int video_enable_only_lcd(const struct dmi_system_id *d)
 387 {
 388         only_lcd = true;
 389         return 0;
 390 }
 391
 392 static int video_set_report_key_events(const struct dmi_system_id *id)
 393 {
 394         if (report_key_events == -1)
 395                 report_key_events = (uintptr_t)id->driver_data;
 396         return 0;
 397 }
 398
 399 static int video_hw_changes_brightness(
 400         const struct dmi_system_id *d)
 401 {
 402         if (hw_changes_brightness == -1)
 403                 hw_changes_brightness = 1;
 404         return 0;
 405 }
 406
 407 static const struct dmi_system_id video_dmi_table[] = {
 408         /*
 409          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 410          */
 411         {
 412          .callback = video_set_bqc_offset,
 413          .ident = "Acer Aspire 5720",
 414          .matches = {
 415                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 416                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 417                 },
 418         },
 419         {
 420          .callback = video_set_bqc_offset,
 421          .ident = "Acer Aspire 5710Z",
 422          .matches = {
 423                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 424                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 425                 },
 426         },
 427         {
 428          .callback = video_set_bqc_offset,
 429          .ident = "eMachines E510",
 430          .matches = {
 431                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 432                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 433                 },
 434         },
 435         {
 436          .callback = video_set_bqc_offset,
 437          .ident = "Acer Aspire 5315",
 438          .matches = {
 439                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 440                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 441                 },
 442         },
 443         {
 444          .callback = video_set_bqc_offset,
 445          .ident = "Acer Aspire 7720",
 446          .matches = {
 447                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 448                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 449                 },
 450         },
 451
 452         /*
 453          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 454          * but the IDs actually follow the Device ID Scheme.
 455          */
 456         {
 457          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 458          .callback = video_set_device_id_scheme,
 459          .ident = "ESPRIMO Mobile M9410",
 460          .matches = {
 461                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 462                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 463                 },
 464         },
 465         /*
 466          * Some machines have multiple video output devices, but only the one
 467          * that is the type of LCD can do the backlight control so we should not
 468          * register backlight interface for other video output devices.
 469          */
 470         {
 471          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 472          .callback = video_enable_only_lcd,
 473          .ident = "ESPRIMO Mobile M9410",
 474          .matches = {
 475                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 476                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 477                 },
 478         },
 479         /*
 480          * Some machines report wrong key events on the acpi-bus, suppress
 481          * key event reporting on these.  Note this is only intended to work
 482          * around events which are plain wrong. In some cases we get double
 483          * events, in this case acpi-video is considered the canonical source
 484          * and the events from the other source should be filtered. E.g.
 485          * by calling acpi_video_handles_brightness_key_presses() from the
 486          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 487          */
 488         {
 489          .callback = video_set_report_key_events,
 490          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 491          .ident = "Dell Vostro V131",
 492          .matches = {
 493                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 494                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 495                 },
 496         },
 497         {
 498          .callback = video_set_report_key_events,
 499          .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 500          .ident = "Dell Vostro 3350",
 501          .matches = {
 502                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 503                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3350"),
 504                 },
 505         },
 506         /*
 507          * Some machines change the brightness themselves when a brightness
 508          * hotkey gets pressed, despite us telling them not to. In this case
 509          * acpi_video_device_notify() should only call backlight_force_update(
 510          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 511          */
 512         {
 513          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 514          .callback = video_hw_changes_brightness,
 515          .ident = "Packard Bell EasyNote MZ35",
 516          .matches = {
 517                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 518                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 519                 },
 520         },
 521         {}
 522 };
 523
 524 static unsigned long long
 525 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 526                               unsigned long long bqc_value)
 527 {
 528         unsigned long long level;
 529
 530         if (device->brightness->flags._BQC_use_index) {
 531                 /*
 532                  * _BQC returns an index that doesn't account for the first 2
 533                  * items with special meaning (see enum acpi_video_level_idx),
 534                  * so we need to compensate for that by offsetting ourselves
 535                  */
 536                 if (device->brightness->flags._BCL_reversed)
 537                         bqc_value = device->brightness->count -
 538                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 539
 540                 level = device->brightness->levels[bqc_value +
 541                                                    ACPI_VIDEO_FIRST_LEVEL];
 542         } else {
 543                 level = bqc_value;
 544         }
 545
 546         level += bqc_offset_aml_bug_workaround;
 547
 548         return level;
 549 }
 550
 551 static int
 552 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 553                                         unsigned long long *level, bool raw)
 554 {
 555         acpi_status status = AE_OK;
 556         int i;
 557
 558         if (device->cap._BQC || device->cap._BCQ) {
 559                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 560
 561                 status = acpi_evaluate_integer(device->dev->handle, buf,
 562                                                 NULL, level);
 563                 if (ACPI_SUCCESS(status)) {
 564                         if (raw) {
 565                                 /*
 566                                  * Caller has indicated he wants the raw
 567                                  * value returned by _BQC, so don't furtherly
 568                                  * mess with the value.
 569                                  */
 570                                 return 0;
 571                         }
 572
 573                         *level = acpi_video_bqc_value_to_level(device, *level);
 574
 575                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 576                              i < device->brightness->count; i++)
 577                                 if (device->brightness->levels[i] == *level) {
 578                                         device->brightness->curr = *level;
 579                                         return 0;
 580                                 }
 581                         /*
 582                          * BQC returned an invalid level.
 583                          * Stop using it.
 584                          */
 585                         acpi_handle_info(device->dev->handle,
 586                                          "%s returned an invalid level", buf);
 587                         device->cap._BQC = device->cap._BCQ = 0;
 588                 } else {
 589                         /*
 590                          * Fixme:
 591                          * should we return an error or ignore this failure?
 592                          * dev->brightness->curr is a cached value which stores
 593                          * the correct current backlight level in most cases.
 594                          * ACPI video backlight still works w/ buggy _BQC.
 595                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 596                          */
 597                         acpi_handle_info(device->dev->handle,
 598                                          "%s evaluation failed", buf);
 599                         device->cap._BQC = device->cap._BCQ = 0;
 600                 }
 601         }
 602
 603         *level = device->brightness->curr;
 604         return 0;
 605 }
 606
 607 static int
 608 acpi_video_device_EDID(struct acpi_video_device *device,
 609                        union acpi_object **edid, ssize_t length)
 610 {
 611         int status;
 612         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 613         union acpi_object *obj;
 614         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 615         struct acpi_object_list args = { 1, &arg0 };
 616
 617
 618         *edid = NULL;
 619
 620         if (!device)
 621                 return -ENODEV;
 622         if (length == 128)
 623                 arg0.integer.value = 1;
 624         else if (length == 256)
 625                 arg0.integer.value = 2;
 626         else
 627                 return -EINVAL;
 628
 629         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 630         if (ACPI_FAILURE(status))
 631                 return -ENODEV;
 632
 633         obj = buffer.pointer;
 634
 635         if (obj && obj->type == ACPI_TYPE_BUFFER)
 636                 *edid = obj;
 637         else {
 638                 acpi_handle_info(device->dev->handle, "Invalid _DDC data\n");
 639                 status = -EFAULT;
 640                 kfree(obj);
 641         }
 642
 643         return status;
 644 }
 645
 646 /* bus */
 647
 648 /*
 649  *  Arg:
 650  *      video           : video bus device pointer
 651  *      bios_flag       :
 652  *              0.      The system BIOS should NOT automatically switch(toggle)
 653  *                      the active display output.
 654  *              1.      The system BIOS should automatically switch (toggle) the
 655  *                      active display output. No switch event.
 656  *              2.      The _DGS value should be locked.
 657  *              3.      The system BIOS should not automatically switch (toggle) the
 658  *                      active display output, but instead generate the display switch
 659  *                      event notify code.
 660  *      lcd_flag        :
 661  *              0.      The system BIOS should automatically control the brightness level
 662  *                      of the LCD when:
 663  *                      - the power changes from AC to DC (ACPI appendix B)
 664  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 665  *              1.      The system BIOS should NOT automatically control the brightness
 666  *                      level of the LCD when:
 667  *                      - the power changes from AC to DC (ACPI appendix B)
 668  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 669  *  Return Value:
 670  *              -EINVAL wrong arg.
 671  */
 672
 673 static int
 674 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 675 {
 676         acpi_status status;
 677
 678         if (!video->cap._DOS)
 679                 return 0;
 680
 681         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 682                 return -EINVAL;
 683         video->dos_setting = (lcd_flag << 2) | bios_flag;
 684         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 685                                             (lcd_flag << 2) | bios_flag);
 686         if (ACPI_FAILURE(status))
 687                 return -EIO;
 688
 689         return 0;
 690 }
 691
 692 /*
 693  * Simple comparison function used to sort backlight levels.
 694  */
 695
 696 static int
 697 acpi_video_cmp_level(const void *a, const void *b)
 698 {
 699         return *(int *)a - *(int *)b;
 700 }
 701
 702 /*
 703  * Decides if _BQC/_BCQ for this system is usable
 704  *
 705  * We do this by changing the level first and then read out the current
 706  * brightness level, if the value does not match, find out if it is using
 707  * index. If not, clear the _BQC/_BCQ capability.
 708  */
 709 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 710                                 int max_level, int current_level)
 711 {
 712         struct acpi_video_device_brightness *br = device->brightness;
 713         int result;
 714         unsigned long long level;
 715         int test_level;
 716
 717         /* don't mess with existing known broken systems */
 718         if (bqc_offset_aml_bug_workaround)
 719                 return 0;
 720
 721         /*
 722          * Some systems always report current brightness level as maximum
 723          * through _BQC, we need to test another value for them. However,
 724          * there is a subtlety:
 725          *
 726          * If the _BCL package ordering is descending, the first level
 727          * (br->levels[2]) is likely to be 0, and if the number of levels
 728          * matches the number of steps, we might confuse a returned level to
 729          * mean the index.
 730          *
 731          * For example:
 732          *
 733          *     current_level = max_level = 100
 734          *     test_level = 0
 735          *     returned level = 100
 736          *
 737          * In this case 100 means the level, not the index, and _BCM failed.
 738          * Still, if the _BCL package ordering is descending, the index of
 739          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 740          *
 741          * This causes all _BQC calls to return bogus values causing weird
 742          * behavior from the user's perspective.  For example:
 743          *
 744          * xbacklight -set 10; xbacklight -set 20;
 745          *
 746          * would flash to 90% and then slowly down to the desired level (20).
 747          *
 748          * The solution is simple; test anything other than the first level
 749          * (e.g. 1).
 750          */
 751         test_level = current_level == max_level
 752                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 753                 : max_level;
 754
 755         result = acpi_video_device_lcd_set_level(device, test_level);
 756         if (result)
 757                 return result;
 758
 759         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 760         if (result)
 761                 return result;
 762
 763         if (level != test_level) {
 764                 /* buggy _BQC found, need to find out if it uses index */
 765                 if (level < br->count) {
 766                         if (br->flags._BCL_reversed)
 767                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 768                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 769                                 br->flags._BQC_use_index = 1;
 770                 }
 771
 772                 if (!br->flags._BQC_use_index)
 773                         device->cap._BQC = device->cap._BCQ = 0;
 774         }
 775
 776         return 0;
 777 }
 778
 779 int acpi_video_get_levels(struct acpi_device *device,
 780                           struct acpi_video_device_brightness **dev_br,
 781                           int *pmax_level)
 782 {
 783         union acpi_object *obj = NULL;
 784         int i, max_level = 0, count = 0, level_ac_battery = 0;
 785         union acpi_object *o;
 786         struct acpi_video_device_brightness *br = NULL;
 787         int result = 0;
 788         u32 value;
 789
 790         if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
 791                 acpi_handle_debug(device->handle,
 792                                   "Could not query available LCD brightness level\n");
 793                 result = -ENODEV;
 794                 goto out;
 795         }
 796
 797         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 798                 result = -EINVAL;
 799                 goto out;
 800         }
 801
 802         br = kzalloc(sizeof(*br), GFP_KERNEL);
 803         if (!br) {
 804                 result = -ENOMEM;
 805                 goto out;
 806         }
 807
 808         /*
 809          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 810          * in order to account for buggy BIOS which don't export the first two
 811          * special levels (see below)
 812          */
 813         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 814                                    sizeof(*br->levels),
 815                                    GFP_KERNEL);
 816         if (!br->levels) {
 817                 result = -ENOMEM;
 818                 goto out_free;
 819         }
 820
 821         for (i = 0; i < obj->package.count; i++) {
 822                 o = (union acpi_object *)&obj->package.elements[i];
 823                 if (o->type != ACPI_TYPE_INTEGER) {
 824                         acpi_handle_info(device->handle, "Invalid data\n");
 825                         continue;
 826                 }
 827                 value = (u32) o->integer.value;
 828                 /* Skip duplicate entries */
 829                 if (count > ACPI_VIDEO_FIRST_LEVEL
 830                     && br->levels[count - 1] == value)
 831                         continue;
 832
 833                 br->levels[count] = value;
 834
 835                 if (br->levels[count] > max_level)
 836                         max_level = br->levels[count];
 837                 count++;
 838         }
 839
 840         /*
 841          * some buggy BIOS don't export the levels
 842          * when machine is on AC/Battery in _BCL package.
 843          * In this case, the first two elements in _BCL packages
 844          * are also supported brightness levels that OS should take care of.
 845          */
 846         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 847                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 848                         level_ac_battery++;
 849                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 850                         level_ac_battery++;
 851         }
 852
 853         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 854                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 855                 br->flags._BCL_no_ac_battery_levels = 1;
 856                 for (i = (count - 1 + level_ac_battery);
 857                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 858                         br->levels[i] = br->levels[i - level_ac_battery];
 859                 count += level_ac_battery;
 860         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 861                 acpi_handle_info(device->handle,
 862                                  "Too many duplicates in _BCL package");
 863
 864         /* Check if the _BCL package is in a reversed order */
 865         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 866                 br->flags._BCL_reversed = 1;
 867                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 868                      count - ACPI_VIDEO_FIRST_LEVEL,
 869                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 870                      acpi_video_cmp_level, NULL);
 871         } else if (max_level != br->levels[count - 1])
 872                 acpi_handle_info(device->handle,
 873                                  "Found unordered _BCL package");
 874
 875         br->count = count;
 876         *dev_br = br;
 877         if (pmax_level)
 878                 *pmax_level = max_level;
 879
 880 out:
 881         kfree(obj);
 882         return result;
 883 out_free:
 884         kfree(br);
 885         goto out;
 886 }
 887 EXPORT_SYMBOL(acpi_video_get_levels);
 888
 889 /*
 890  *  Arg:
 891  *      device  : video output device (LCD, CRT, ..)
 892  *
 893  *  Return Value:
 894  *      Maximum brightness level
 895  *
 896  *  Allocate and initialize device->brightness.
 897  */
 898
 899 static int
 900 acpi_video_init_brightness(struct acpi_video_device *device)
 901 {
 902         int i, max_level = 0;
 903         unsigned long long level, level_old;
 904         struct acpi_video_device_brightness *br = NULL;
 905         int result;
 906
 907         result = acpi_video_get_levels(device->dev, &br, &max_level);
 908         if (result)
 909                 return result;
 910         device->brightness = br;
 911
 912         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 913         br->curr = level = max_level;
 914
 915         if (!device->cap._BQC)
 916                 goto set_level;
 917
 918         result = acpi_video_device_lcd_get_level_current(device,
 919                                                          &level_old, true);
 920         if (result)
 921                 goto out_free_levels;
 922
 923         result = acpi_video_bqc_quirk(device, max_level, level_old);
 924         if (result)
 925                 goto out_free_levels;
 926         /*
 927          * cap._BQC may get cleared due to _BQC is found to be broken
 928          * in acpi_video_bqc_quirk, so check again here.
 929          */
 930         if (!device->cap._BQC)
 931                 goto set_level;
 932
 933         level = acpi_video_bqc_value_to_level(device, level_old);
 934         /*
 935          * On some buggy laptops, _BQC returns an uninitialized
 936          * value when invoked for the first time, i.e.
 937          * level_old is invalid (no matter whether it's a level
 938          * or an index). Set the backlight to max_level in this case.
 939          */
 940         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 941                 if (level == br->levels[i])
 942                         break;
 943         if (i == br->count || !level)
 944                 level = max_level;
 945
 946 set_level:
 947         result = acpi_video_device_lcd_set_level(device, level);
 948         if (result)
 949                 goto out_free_levels;
 950
 951         acpi_handle_debug(device->dev->handle, "found %d brightness levels\n",
 952                           br->count - ACPI_VIDEO_FIRST_LEVEL);
 953
 954         return 0;
 955
 956 out_free_levels:
 957         kfree(br->levels);
 958         kfree(br);
 959         device->brightness = NULL;
 960         return result;
 961 }
 962
 963 /*
 964  *  Arg:
 965  *      device  : video output device (LCD, CRT, ..)
 966  *
 967  *  Return Value:
 968  *      None
 969  *
 970  *  Find out all required AML methods defined under the output
 971  *  device.
 972  */
 973
 974 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 975 {
 976         if (acpi_has_method(device->dev->handle, "_ADR"))
 977                 device->cap._ADR = 1;
 978         if (acpi_has_method(device->dev->handle, "_BCL"))
 979                 device->cap._BCL = 1;
 980         if (acpi_has_method(device->dev->handle, "_BCM"))
 981                 device->cap._BCM = 1;
 982         if (acpi_has_method(device->dev->handle, "_BQC")) {
 983                 device->cap._BQC = 1;
 984         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 985                 acpi_handle_info(device->dev->handle,
 986                                  "_BCQ is used instead of _BQC\n");
 987                 device->cap._BCQ = 1;
 988         }
 989
 990         if (acpi_has_method(device->dev->handle, "_DDC"))
 991                 device->cap._DDC = 1;
 992 }
 993
 994 /*
 995  *  Arg:
 996  *      device  : video output device (VGA)
 997  *
 998  *  Return Value:
 999  *      None
1000  *
1001  *  Find out all required AML methods defined under the video bus device.
1002  */
1003
1004 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1005 {
1006         if (acpi_has_method(video->device->handle, "_DOS"))
1007                 video->cap._DOS = 1;
1008         if (acpi_has_method(video->device->handle, "_DOD"))
1009                 video->cap._DOD = 1;
1010         if (acpi_has_method(video->device->handle, "_ROM"))
1011                 video->cap._ROM = 1;
1012         if (acpi_has_method(video->device->handle, "_GPD"))
1013                 video->cap._GPD = 1;
1014         if (acpi_has_method(video->device->handle, "_SPD"))
1015                 video->cap._SPD = 1;
1016         if (acpi_has_method(video->device->handle, "_VPO"))
1017                 video->cap._VPO = 1;
1018 }
1019
1020 /*
1021  * Check whether the video bus device has required AML method to
1022  * support the desired features
1023  */
1024
1025 static int acpi_video_bus_check(struct acpi_video_bus *video)
1026 {
1027         acpi_status status = -ENOENT;
1028         struct pci_dev *dev;
1029
1030         if (!video)
1031                 return -EINVAL;
1032
1033         dev = acpi_get_pci_dev(video->device->handle);
1034         if (!dev)
1035                 return -ENODEV;
1036         pci_dev_put(dev);
1037
1038         /*
1039          * Since there is no HID, CID and so on for VGA driver, we have
1040          * to check well known required nodes.
1041          */
1042
1043         /* Does this device support video switching? */
1044         if (video->cap._DOS || video->cap._DOD) {
1045                 if (!video->cap._DOS) {
1046                         pr_info(FW_BUG "ACPI(%s) defines _DOD but not _DOS\n",
1047                                 acpi_device_bid(video->device));
1048                 }
1049                 video->flags.multihead = 1;
1050                 status = 0;
1051         }
1052
1053         /* Does this device support retrieving a video ROM? */
1054         if (video->cap._ROM) {
1055                 video->flags.rom = 1;
1056                 status = 0;
1057         }
1058
1059         /* Does this device support configuring which video device to POST? */
1060         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1061                 video->flags.post = 1;
1062                 status = 0;
1063         }
1064
1065         return status;
1066 }
1067
1068 /*
1069  * --------------------------------------------------------------------------
1070  *                               Driver Interface
1071  * --------------------------------------------------------------------------
1072  */
1073
1074 /* device interface */
1075 static struct acpi_video_device_attrib *
1076 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1077 {
1078         struct acpi_video_enumerated_device *ids;
1079         int i;
1080
1081         for (i = 0; i < video->attached_count; i++) {
1082                 ids = &video->attached_array[i];
1083                 if ((ids->value.int_val & 0xffff) == device_id)
1084                         return &ids->value.attrib;
1085         }
1086
1087         return NULL;
1088 }
1089
1090 static int
1091 acpi_video_get_device_type(struct acpi_video_bus *video,
1092                            unsigned long device_id)
1093 {
1094         struct acpi_video_enumerated_device *ids;
1095         int i;
1096
1097         for (i = 0; i < video->attached_count; i++) {
1098                 ids = &video->attached_array[i];
1099                 if ((ids->value.int_val & 0xffff) == device_id)
1100                         return ids->value.int_val;
1101         }
1102
1103         return 0;
1104 }
1105
1106 static int acpi_video_bus_get_one_device(struct acpi_device *device, void *arg)
1107 {
1108         struct acpi_video_bus *video = arg;
1109         struct acpi_video_device_attrib *attribute;
1110         struct acpi_video_device *data;
1111         unsigned long long device_id;
1112         acpi_status status;
1113         int device_type;
1114
1115         status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1116         /* Skip devices without _ADR instead of failing. */
1117         if (ACPI_FAILURE(status))
1118                 goto exit;
1119
1120         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1121         if (!data) {
1122                 dev_dbg(&device->dev, "Cannot attach\n");
1123                 return -ENOMEM;
1124         }
1125
1126         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1127         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1128         device->driver_data = data;
1129
1130         data->device_id = device_id;
1131         data->video = video;
1132         data->dev = device;
1133         INIT_DELAYED_WORK(&data->switch_brightness_work,
1134                           acpi_video_switch_brightness);
1135
1136         attribute = acpi_video_get_device_attr(video, device_id);
1137
1138         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1139                 switch (attribute->display_type) {
1140                 case ACPI_VIDEO_DISPLAY_CRT:
1141                         data->flags.crt = 1;
1142                         break;
1143                 case ACPI_VIDEO_DISPLAY_TV:
1144                         data->flags.tvout = 1;
1145                         break;
1146                 case ACPI_VIDEO_DISPLAY_DVI:
1147                         data->flags.dvi = 1;
1148                         break;
1149                 case ACPI_VIDEO_DISPLAY_LCD:
1150                         data->flags.lcd = 1;
1151                         break;
1152                 default:
1153                         data->flags.unknown = 1;
1154                         break;
1155                 }
1156                 if (attribute->bios_can_detect)
1157                         data->flags.bios = 1;
1158         } else {
1159                 /* Check for legacy IDs */
1160                 device_type = acpi_video_get_device_type(video, device_id);
1161                 /* Ignore bits 16 and 18-20 */
1162                 switch (device_type & 0xffe2ffff) {
1163                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1164                         data->flags.crt = 1;
1165                         break;
1166                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1167                         data->flags.lcd = 1;
1168                         break;
1169                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1170                         data->flags.tvout = 1;
1171                         break;
1172                 default:
1173                         data->flags.unknown = 1;
1174                 }
1175         }
1176
1177         acpi_video_device_bind(video, data);
1178         acpi_video_device_find_cap(data);
1179
1180         if (data->cap._BCM && data->cap._BCL)
1181                 may_report_brightness_keys = true;
1182
1183         mutex_lock(&video->device_list_lock);
1184         list_add_tail(&data->entry, &video->video_device_list);
1185         mutex_unlock(&video->device_list_lock);
1186
1187 exit:
1188         video->child_count++;
1189         return 0;
1190 }
1191
1192 /*
1193  *  Arg:
1194  *      video   : video bus device
1195  *
1196  *  Return:
1197  *      none
1198  *
1199  *  Enumerate the video device list of the video bus,
1200  *  bind the ids with the corresponding video devices
1201  *  under the video bus.
1202  */
1203
1204 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1205 {
1206         struct acpi_video_device *dev;
1207
1208         mutex_lock(&video->device_list_lock);
1209
1210         list_for_each_entry(dev, &video->video_device_list, entry)
1211                 acpi_video_device_bind(video, dev);
1212
1213         mutex_unlock(&video->device_list_lock);
1214 }
1215
1216 /*
1217  *  Arg:
1218  *      video   : video bus device
1219  *      device  : video output device under the video
1220  *              bus
1221  *
1222  *  Return:
1223  *      none
1224  *
1225  *  Bind the ids with the corresponding video devices
1226  *  under the video bus.
1227  */
1228
1229 static void
1230 acpi_video_device_bind(struct acpi_video_bus *video,
1231                        struct acpi_video_device *device)
1232 {
1233         struct acpi_video_enumerated_device *ids;
1234         int i;
1235
1236         for (i = 0; i < video->attached_count; i++) {
1237                 ids = &video->attached_array[i];
1238                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1239                         ids->bind_info = device;
1240                         acpi_handle_debug(video->device->handle, "%s: %d\n",
1241                                           __func__, i);
1242                 }
1243         }
1244 }
1245
1246 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1247 {
1248         struct acpi_video_bus *video = device->video;
1249         int i;
1250
1251         /*
1252          * If we have a broken _DOD or we have more than 8 output devices
1253          * under the graphics controller node that we can't proper deal with
1254          * in the operation region code currently, no need to test.
1255          */
1256         if (!video->attached_count || video->child_count > 8)
1257                 return true;
1258
1259         for (i = 0; i < video->attached_count; i++) {
1260                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1261                     (device->device_id & 0xfff))
1262                         return true;
1263         }
1264
1265         return false;
1266 }
1267
1268 /*
1269  *  Arg:
1270  *      video   : video bus device
1271  *
1272  *  Return:
1273  *      < 0     : error
1274  *
1275  *  Call _DOD to enumerate all devices attached to display adapter
1276  *
1277  */
1278
1279 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1280 {
1281         int status;
1282         int count;
1283         int i;
1284         struct acpi_video_enumerated_device *active_list;
1285         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1286         union acpi_object *dod = NULL;
1287         union acpi_object *obj;
1288
1289         if (!video->cap._DOD)
1290                 return AE_NOT_EXIST;
1291
1292         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1293         if (ACPI_FAILURE(status)) {
1294                 acpi_handle_info(video->device->handle,
1295                                  "_DOD evaluation failed: %s\n",
1296                                  acpi_format_exception(status));
1297                 return status;
1298         }
1299
1300         dod = buffer.pointer;
1301         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1302                 acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1303                 status = -EFAULT;
1304                 goto out;
1305         }
1306
1307         acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1308                           dod->package.count);
1309
1310         active_list = kcalloc(1 + dod->package.count,
1311                               sizeof(struct acpi_video_enumerated_device),
1312                               GFP_KERNEL);
1313         if (!active_list) {
1314                 status = -ENOMEM;
1315                 goto out;
1316         }
1317
1318         count = 0;
1319         for (i = 0; i < dod->package.count; i++) {
1320                 obj = &dod->package.elements[i];
1321
1322                 if (obj->type != ACPI_TYPE_INTEGER) {
1323                         acpi_handle_info(video->device->handle,
1324                                          "Invalid _DOD data in element %d\n", i);
1325                         continue;
1326                 }
1327
1328                 active_list[count].value.int_val = obj->integer.value;
1329                 active_list[count].bind_info = NULL;
1330
1331                 acpi_handle_debug(video->device->handle,
1332                                   "_DOD element[%d] = %d\n", i,
1333                                   (int)obj->integer.value);
1334
1335                 count++;
1336         }
1337
1338         kfree(video->attached_array);
1339
1340         video->attached_array = active_list;
1341         video->attached_count = count;
1342
1343 out:
1344         kfree(buffer.pointer);
1345         return status;
1346 }
1347
1348 static int
1349 acpi_video_get_next_level(struct acpi_video_device *device,
1350                           u32 level_current, u32 event)
1351 {
1352         int min, max, min_above, max_below, i, l, delta = 255;
1353         max = max_below = 0;
1354         min = min_above = 255;
1355         /* Find closest level to level_current */
1356         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1357                 l = device->brightness->levels[i];
1358                 if (abs(l - level_current) < abs(delta)) {
1359                         delta = l - level_current;
1360                         if (!delta)
1361                                 break;
1362                 }
1363         }
1364         /* Adjust level_current to closest available level */
1365         level_current += delta;
1366         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1367                 l = device->brightness->levels[i];
1368                 if (l < min)
1369                         min = l;
1370                 if (l > max)
1371                         max = l;
1372                 if (l < min_above && l > level_current)
1373                         min_above = l;
1374                 if (l > max_below && l < level_current)
1375                         max_below = l;
1376         }
1377
1378         switch (event) {
1379         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1380                 return (level_current < max) ? min_above : min;
1381         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1382                 return (level_current < max) ? min_above : max;
1383         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1384                 return (level_current > min) ? max_below : min;
1385         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1386         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1387                 return 0;
1388         default:
1389                 return level_current;
1390         }
1391 }
1392
1393 static void
1394 acpi_video_switch_brightness(struct work_struct *work)
1395 {
1396         struct acpi_video_device *device = container_of(to_delayed_work(work),
1397                              struct acpi_video_device, switch_brightness_work);
1398         unsigned long long level_current, level_next;
1399         int event = device->switch_brightness_event;
1400         int result = -EINVAL;
1401
1402         /* no warning message if acpi_backlight=vendor or a quirk is used */
1403         if (!device->backlight)
1404                 return;
1405
1406         if (!device->brightness)
1407                 goto out;
1408
1409         result = acpi_video_device_lcd_get_level_current(device,
1410                                                          &level_current,
1411                                                          false);
1412         if (result)
1413                 goto out;
1414
1415         level_next = acpi_video_get_next_level(device, level_current, event);
1416
1417         result = acpi_video_device_lcd_set_level(device, level_next);
1418
1419         if (!result)
1420                 backlight_force_update(device->backlight,
1421                                        BACKLIGHT_UPDATE_HOTKEY);
1422
1423 out:
1424         if (result)
1425                 acpi_handle_info(device->dev->handle,
1426                                  "Failed to switch brightness\n");
1427 }
1428
1429 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1430                         void **edid)
1431 {
1432         struct acpi_video_bus *video;
1433         struct acpi_video_device *video_device;
1434         union acpi_object *buffer = NULL;
1435         acpi_status status;
1436         int i, length;
1437
1438         if (!device || !acpi_driver_data(device))
1439                 return -EINVAL;
1440
1441         video = acpi_driver_data(device);
1442
1443         for (i = 0; i < video->attached_count; i++) {
1444                 video_device = video->attached_array[i].bind_info;
1445                 length = 256;
1446
1447                 if (!video_device)
1448                         continue;
1449
1450                 if (!video_device->cap._DDC)
1451                         continue;
1452
1453                 if (type) {
1454                         switch (type) {
1455                         case ACPI_VIDEO_DISPLAY_CRT:
1456                                 if (!video_device->flags.crt)
1457                                         continue;
1458                                 break;
1459                         case ACPI_VIDEO_DISPLAY_TV:
1460                                 if (!video_device->flags.tvout)
1461                                         continue;
1462                                 break;
1463                         case ACPI_VIDEO_DISPLAY_DVI:
1464                                 if (!video_device->flags.dvi)
1465                                         continue;
1466                                 break;
1467                         case ACPI_VIDEO_DISPLAY_LCD:
1468                                 if (!video_device->flags.lcd)
1469                                         continue;
1470                                 break;
1471                         }
1472                 } else if (video_device->device_id != device_id) {
1473                         continue;
1474                 }
1475
1476                 status = acpi_video_device_EDID(video_device, &buffer, length);
1477
1478                 if (ACPI_FAILURE(status) || !buffer ||
1479                     buffer->type != ACPI_TYPE_BUFFER) {
1480                         length = 128;
1481                         status = acpi_video_device_EDID(video_device, &buffer,
1482                                                         length);
1483                         if (ACPI_FAILURE(status) || !buffer ||
1484                             buffer->type != ACPI_TYPE_BUFFER) {
1485                                 continue;
1486                         }
1487                 }
1488
1489                 *edid = buffer->buffer.pointer;
1490                 return length;
1491         }
1492
1493         return -ENODEV;
1494 }
1495 EXPORT_SYMBOL(acpi_video_get_edid);
1496
1497 static int
1498 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1499                            struct acpi_device *device)
1500 {
1501         /*
1502          * There are systems where video module known to work fine regardless
1503          * of broken _DOD and ignoring returned value here doesn't cause
1504          * any issues later.
1505          */
1506         acpi_video_device_enumerate(video);
1507
1508         return acpi_dev_for_each_child(device, acpi_video_bus_get_one_device, video);
1509 }
1510
1511 /* acpi_video interface */
1512
1513 /*
1514  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1515  * perform any automatic brightness change on receiving a notification.
1516  */
1517 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1518 {
1519         return acpi_video_bus_DOS(video, 0,
1520                                   acpi_osi_is_win8() ? 1 : 0);
1521 }
1522
1523 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1524 {
1525         return acpi_video_bus_DOS(video, 0,
1526                                   acpi_osi_is_win8() ? 0 : 1);
1527 }
1528
1529 static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data)
1530 {
1531         struct acpi_device *device = data;
1532         struct acpi_video_bus *video = acpi_driver_data(device);
1533         struct input_dev *input;
1534         int keycode = 0;
1535
1536         if (!video || !video->input)
1537                 return;
1538
1539         input = video->input;
1540
1541         switch (event) {
1542         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1543                                          * most likely via hotkey. */
1544                 keycode = KEY_SWITCHVIDEOMODE;
1545                 break;
1546
1547         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1548                                          * connector. */
1549                 acpi_video_device_enumerate(video);
1550                 acpi_video_device_rebind(video);
1551                 keycode = KEY_SWITCHVIDEOMODE;
1552                 break;
1553
1554         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1555                 keycode = KEY_SWITCHVIDEOMODE;
1556                 break;
1557         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1558                 keycode = KEY_VIDEO_NEXT;
1559                 break;
1560         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1561                 keycode = KEY_VIDEO_PREV;
1562                 break;
1563
1564         default:
1565                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1566                                   event);
1567                 break;
1568         }
1569
1570         if (acpi_notifier_call_chain(device, event, 0))
1571                 /* Something vetoed the keypress. */
1572                 keycode = 0;
1573
1574         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1575                 input_report_key(input, keycode, 1);
1576                 input_sync(input);
1577                 input_report_key(input, keycode, 0);
1578                 input_sync(input);
1579         }
1580 }
1581
1582 static void brightness_switch_event(struct acpi_video_device *video_device,
1583                                     u32 event)
1584 {
1585         if (!brightness_switch_enabled)
1586                 return;
1587
1588         video_device->switch_brightness_event = event;
1589         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1590 }
1591
1592 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1593 {
1594         struct acpi_video_device *video_device = data;
1595         struct acpi_device *device = NULL;
1596         struct acpi_video_bus *bus;
1597         struct input_dev *input;
1598         int keycode = 0;
1599
1600         if (!video_device)
1601                 return;
1602
1603         device = video_device->dev;
1604         bus = video_device->video;
1605         input = bus->input;
1606
1607         if (hw_changes_brightness > 0) {
1608                 if (video_device->backlight)
1609                         backlight_force_update(video_device->backlight,
1610                                                BACKLIGHT_UPDATE_HOTKEY);
1611                 acpi_notifier_call_chain(device, event, 0);
1612                 return;
1613         }
1614
1615         switch (event) {
1616         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1617                 brightness_switch_event(video_device, event);
1618                 keycode = KEY_BRIGHTNESS_CYCLE;
1619                 break;
1620         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1621                 brightness_switch_event(video_device, event);
1622                 keycode = KEY_BRIGHTNESSUP;
1623                 break;
1624         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1625                 brightness_switch_event(video_device, event);
1626                 keycode = KEY_BRIGHTNESSDOWN;
1627                 break;
1628         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1629                 brightness_switch_event(video_device, event);
1630                 keycode = KEY_BRIGHTNESS_ZERO;
1631                 break;
1632         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1633                 brightness_switch_event(video_device, event);
1634                 keycode = KEY_DISPLAY_OFF;
1635                 break;
1636         default:
1637                 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1638                 break;
1639         }
1640
1641         if (keycode)
1642                 may_report_brightness_keys = true;
1643
1644         acpi_notifier_call_chain(device, event, 0);
1645
1646         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1647                 input_report_key(input, keycode, 1);
1648                 input_sync(input);
1649                 input_report_key(input, keycode, 0);
1650                 input_sync(input);
1651         }
1652 }
1653
1654 static int acpi_video_resume(struct notifier_block *nb,
1655                                 unsigned long val, void *ign)
1656 {
1657         struct acpi_video_bus *video;
1658         struct acpi_video_device *video_device;
1659         int i;
1660
1661         switch (val) {
1662         case PM_POST_HIBERNATION:
1663         case PM_POST_SUSPEND:
1664         case PM_POST_RESTORE:
1665                 video = container_of(nb, struct acpi_video_bus, pm_nb);
1666
1667                 dev_info(&video->device->dev, "Restoring backlight state\n");
1668
1669                 for (i = 0; i < video->attached_count; i++) {
1670                         video_device = video->attached_array[i].bind_info;
1671                         if (video_device && video_device->brightness)
1672                                 acpi_video_device_lcd_set_level(video_device,
1673                                                 video_device->brightness->curr);
1674                 }
1675
1676                 return NOTIFY_OK;
1677         }
1678         return NOTIFY_DONE;
1679 }
1680
1681 static acpi_status
1682 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1683                         void **return_value)
1684 {
1685         struct acpi_device *device = context;
1686         struct acpi_device *sibling;
1687
1688         if (handle == device->handle)
1689                 return AE_CTRL_TERMINATE;
1690
1691         sibling = acpi_fetch_acpi_dev(handle);
1692         if (!sibling)
1693                 return AE_OK;
1694
1695         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1696                         return AE_ALREADY_EXISTS;
1697
1698         return AE_OK;
1699 }
1700
1701 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1702 {
1703         struct backlight_properties props;
1704         struct pci_dev *pdev;
1705         acpi_handle acpi_parent;
1706         struct device *parent = NULL;
1707         int result;
1708         static int count;
1709         char *name;
1710
1711         result = acpi_video_init_brightness(device);
1712         if (result)
1713                 return;
1714
1715         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1716         if (!name)
1717                 return;
1718         count++;
1719
1720         acpi_get_parent(device->dev->handle, &acpi_parent);
1721
1722         pdev = acpi_get_pci_dev(acpi_parent);
1723         if (pdev) {
1724                 parent = &pdev->dev;
1725                 pci_dev_put(pdev);
1726         }
1727
1728         memset(&props, 0, sizeof(struct backlight_properties));
1729         props.type = BACKLIGHT_FIRMWARE;
1730         props.max_brightness =
1731                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1732         device->backlight = backlight_device_register(name,
1733                                                       parent,
1734                                                       device,
1735                                                       &acpi_backlight_ops,
1736                                                       &props);
1737         kfree(name);
1738         if (IS_ERR(device->backlight)) {
1739                 device->backlight = NULL;
1740                 return;
1741         }
1742
1743         /*
1744          * Save current brightness level in case we have to restore it
1745          * before acpi_video_device_lcd_set_level() is called next time.
1746          */
1747         device->backlight->props.brightness =
1748                         acpi_video_get_brightness(device->backlight);
1749
1750         device->cooling_dev = thermal_cooling_device_register("LCD",
1751                                 device->dev, &video_cooling_ops);
1752         if (IS_ERR(device->cooling_dev)) {
1753                 /*
1754                  * Set cooling_dev to NULL so we don't crash trying to free it.
1755                  * Also, why the hell we are returning early and not attempt to
1756                  * register video output if cooling device registration failed?
1757                  * -- dtor
1758                  */
1759                 device->cooling_dev = NULL;
1760                 return;
1761         }
1762
1763         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1764                  device->cooling_dev->id);
1765         result = sysfs_create_link(&device->dev->dev.kobj,
1766                         &device->cooling_dev->device.kobj,
1767                         "thermal_cooling");
1768         if (result)
1769                 pr_info("sysfs link creation failed\n");
1770
1771         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1772                         &device->dev->dev.kobj, "device");
1773         if (result)
1774                 pr_info("Reverse sysfs link creation failed\n");
1775 }
1776
1777 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1778 {
1779         struct acpi_video_device *dev;
1780         union acpi_object *levels;
1781
1782         mutex_lock(&video->device_list_lock);
1783         list_for_each_entry(dev, &video->video_device_list, entry) {
1784                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1785                         kfree(levels);
1786         }
1787         mutex_unlock(&video->device_list_lock);
1788 }
1789
1790 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1791 {
1792         /*
1793          * Do not create backlight device for video output
1794          * device that is not in the enumerated list.
1795          */
1796         if (!acpi_video_device_in_dod(dev)) {
1797                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1798                 return false;
1799         }
1800
1801         if (only_lcd)
1802                 return dev->flags.lcd;
1803         return true;
1804 }
1805
1806 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1807 {
1808         struct acpi_video_device *dev;
1809
1810         if (video->backlight_registered)
1811                 return 0;
1812
1813         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1814                 return 0;
1815
1816         mutex_lock(&video->device_list_lock);
1817         list_for_each_entry(dev, &video->video_device_list, entry) {
1818                 if (acpi_video_should_register_backlight(dev))
1819                         acpi_video_dev_register_backlight(dev);
1820         }
1821         mutex_unlock(&video->device_list_lock);
1822
1823         video->backlight_registered = true;
1824
1825         video->pm_nb.notifier_call = acpi_video_resume;
1826         video->pm_nb.priority = 0;
1827         return register_pm_notifier(&video->pm_nb);
1828 }
1829
1830 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1831 {
1832         if (device->backlight) {
1833                 backlight_device_unregister(device->backlight);
1834                 device->backlight = NULL;
1835         }
1836         if (device->brightness) {
1837                 kfree(device->brightness->levels);
1838                 kfree(device->brightness);
1839                 device->brightness = NULL;
1840         }
1841         if (device->cooling_dev) {
1842                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1843                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1844                 thermal_cooling_device_unregister(device->cooling_dev);
1845                 device->cooling_dev = NULL;
1846         }
1847 }
1848
1849 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1850 {
1851         struct acpi_video_device *dev;
1852         int error;
1853
1854         if (!video->backlight_registered)
1855                 return 0;
1856
1857         error = unregister_pm_notifier(&video->pm_nb);
1858
1859         mutex_lock(&video->device_list_lock);
1860         list_for_each_entry(dev, &video->video_device_list, entry)
1861                 acpi_video_dev_unregister_backlight(dev);
1862         mutex_unlock(&video->device_list_lock);
1863
1864         video->backlight_registered = false;
1865
1866         return error;
1867 }
1868
1869 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1870 {
1871         acpi_status status;
1872         struct acpi_device *adev = device->dev;
1873
1874         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1875                                              acpi_video_device_notify, device);
1876         if (ACPI_FAILURE(status))
1877                 dev_err(&adev->dev, "Error installing notify handler\n");
1878         else
1879                 device->flags.notify = 1;
1880 }
1881
1882 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1883 {
1884         struct input_dev *input;
1885         struct acpi_video_device *dev;
1886         int error;
1887
1888         video->input = input = input_allocate_device();
1889         if (!input) {
1890                 error = -ENOMEM;
1891                 goto out;
1892         }
1893
1894         error = acpi_video_bus_start_devices(video);
1895         if (error)
1896                 goto err_free_input;
1897
1898         snprintf(video->phys, sizeof(video->phys),
1899                         "%s/video/input0", acpi_device_hid(video->device));
1900
1901         input->name = acpi_device_name(video->device);
1902         input->phys = video->phys;
1903         input->id.bustype = BUS_HOST;
1904         input->id.product = 0x06;
1905         input->dev.parent = &video->device->dev;
1906         input->evbit[0] = BIT(EV_KEY);
1907         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1908         set_bit(KEY_VIDEO_NEXT, input->keybit);
1909         set_bit(KEY_VIDEO_PREV, input->keybit);
1910         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1911         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1912         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1913         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1914         set_bit(KEY_DISPLAY_OFF, input->keybit);
1915
1916         error = input_register_device(input);
1917         if (error)
1918                 goto err_stop_dev;
1919
1920         mutex_lock(&video->device_list_lock);
1921         list_for_each_entry(dev, &video->video_device_list, entry)
1922                 acpi_video_dev_add_notify_handler(dev);
1923         mutex_unlock(&video->device_list_lock);
1924
1925         return 0;
1926
1927 err_stop_dev:
1928         acpi_video_bus_stop_devices(video);
1929 err_free_input:
1930         input_free_device(input);
1931         video->input = NULL;
1932 out:
1933         return error;
1934 }
1935
1936 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1937 {
1938         if (dev->flags.notify) {
1939                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1940                                            acpi_video_device_notify);
1941                 dev->flags.notify = 0;
1942         }
1943 }
1944
1945 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1946 {
1947         struct acpi_video_device *dev;
1948
1949         mutex_lock(&video->device_list_lock);
1950         list_for_each_entry(dev, &video->video_device_list, entry)
1951                 acpi_video_dev_remove_notify_handler(dev);
1952         mutex_unlock(&video->device_list_lock);
1953
1954         acpi_video_bus_stop_devices(video);
1955         input_unregister_device(video->input);
1956         video->input = NULL;
1957 }
1958
1959 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1960 {
1961         struct acpi_video_device *dev, *next;
1962
1963         mutex_lock(&video->device_list_lock);
1964         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1965                 list_del(&dev->entry);
1966                 kfree(dev);
1967         }
1968         mutex_unlock(&video->device_list_lock);
1969
1970         return 0;
1971 }
1972
1973 static int instance;
1974
1975 static int acpi_video_bus_add(struct acpi_device *device)
1976 {
1977         struct acpi_video_bus *video;
1978         bool auto_detect;
1979         int error;
1980         acpi_status status;
1981
1982         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1983                                 acpi_dev_parent(device)->handle, 1,
1984                                 acpi_video_bus_match, NULL,
1985                                 device, NULL);
1986         if (status == AE_ALREADY_EXISTS) {
1987                 pr_info(FW_BUG
1988                         "Duplicate ACPI video bus devices for the"
1989                         " same VGA controller, please try module "
1990                         "parameter \"video.allow_duplicates=1\""
1991                         "if the current driver doesn't work.\n");
1992                 if (!allow_duplicates)
1993                         return -ENODEV;
1994         }
1995
1996         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1997         if (!video)
1998                 return -ENOMEM;
1999
2000         /* a hack to fix the duplicate name "VID" problem on T61 */
2001         if (!strcmp(device->pnp.bus_id, "VID")) {
2002                 if (instance)
2003                         device->pnp.bus_id[3] = '0' + instance;
2004                 instance++;
2005         }
2006         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2007         if (!strcmp(device->pnp.bus_id, "VGA")) {
2008                 if (instance)
2009                         device->pnp.bus_id[3] = '0' + instance;
2010                 instance++;
2011         }
2012
2013         video->device = device;
2014         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2015         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2016         device->driver_data = video;
2017
2018         acpi_video_bus_find_cap(video);
2019         error = acpi_video_bus_check(video);
2020         if (error)
2021                 goto err_free_video;
2022
2023         mutex_init(&video->device_list_lock);
2024         INIT_LIST_HEAD(&video->video_device_list);
2025
2026         error = acpi_video_bus_get_devices(video, device);
2027         if (error)
2028                 goto err_put_video;
2029
2030         /*
2031          * HP ZBook Fury 16 G10 requires ACPI video's child devices have _PS0
2032          * evaluated to have functional panel brightness control.
2033          */
2034         acpi_device_fix_up_power_extended(device);
2035
2036         pr_info("%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2037                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2038                video->flags.multihead ? "yes" : "no",
2039                video->flags.rom ? "yes" : "no",
2040                video->flags.post ? "yes" : "no");
2041         mutex_lock(&video_list_lock);
2042         list_add_tail(&video->entry, &video_bus_head);
2043         mutex_unlock(&video_list_lock);
2044
2045         /*
2046          * If backlight-type auto-detection is used then a native backlight may
2047          * show up later and this may change the result from video to native.
2048          * Therefor normally the userspace visible /sys/class/backlight device
2049          * gets registered separately by the GPU driver calling
2050          * acpi_video_register_backlight() when an internal panel is detected.
2051          * Register the backlight now when not using auto-detection, so that
2052          * when the kernel cmdline or DMI-quirks are used the backlight will
2053          * get registered even if acpi_video_register_backlight() is not called.
2054          */
2055         acpi_video_run_bcl_for_osi(video);
2056         if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video &&
2057             !auto_detect)
2058                 acpi_video_bus_register_backlight(video);
2059
2060         error = acpi_video_bus_add_notify_handler(video);
2061         if (error)
2062                 goto err_del;
2063
2064         error = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
2065                                                 acpi_video_bus_notify, device);
2066         if (error)
2067                 goto err_remove;
2068
2069         return 0;
2070
2071 err_remove:
2072         acpi_video_bus_remove_notify_handler(video);
2073 err_del:
2074         mutex_lock(&video_list_lock);
2075         list_del(&video->entry);
2076         mutex_unlock(&video_list_lock);
2077         acpi_video_bus_unregister_backlight(video);
2078 err_put_video:
2079         acpi_video_bus_put_devices(video);
2080         kfree(video->attached_array);
2081 err_free_video:
2082         kfree(video);
2083         device->driver_data = NULL;
2084
2085         return error;
2086 }
2087
2088 static void acpi_video_bus_remove(struct acpi_device *device)
2089 {
2090         struct acpi_video_bus *video = NULL;
2091
2092
2093         if (!device || !acpi_driver_data(device))
2094                 return;
2095
2096         video = acpi_driver_data(device);
2097
2098         acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
2099                                        acpi_video_bus_notify);
2100
2101         mutex_lock(&video_list_lock);
2102         list_del(&video->entry);
2103         mutex_unlock(&video_list_lock);
2104
2105         acpi_video_bus_remove_notify_handler(video);
2106         acpi_video_bus_unregister_backlight(video);
2107         acpi_video_bus_put_devices(video);
2108
2109         kfree(video->attached_array);
2110         kfree(video);
2111 }
2112
2113 static int __init is_i740(struct pci_dev *dev)
2114 {
2115         if (dev->device == 0x00D1)
2116                 return 1;
2117         if (dev->device == 0x7000)
2118                 return 1;
2119         return 0;
2120 }
2121
2122 static int __init intel_opregion_present(void)
2123 {
2124         int opregion = 0;
2125         struct pci_dev *dev = NULL;
2126         u32 address;
2127
2128         for_each_pci_dev(dev) {
2129                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2130                         continue;
2131                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2132                         continue;
2133                 /* We don't want to poke around undefined i740 registers */
2134                 if (is_i740(dev))
2135                         continue;
2136                 pci_read_config_dword(dev, 0xfc, &address);
2137                 if (!address)
2138                         continue;
2139                 opregion = 1;
2140         }
2141         return opregion;
2142 }
2143
2144 /* Check if the chassis-type indicates there is no builtin LCD panel */
2145 static bool dmi_is_desktop(void)
2146 {
2147         const char *chassis_type;
2148         unsigned long type;
2149
2150         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2151         if (!chassis_type)
2152                 return false;
2153
2154         if (kstrtoul(chassis_type, 10, &type) != 0)
2155                 return false;
2156
2157         switch (type) {
2158         case 0x03: /* Desktop */
2159         case 0x04: /* Low Profile Desktop */
2160         case 0x05: /* Pizza Box */
2161         case 0x06: /* Mini Tower */
2162         case 0x07: /* Tower */
2163         case 0x10: /* Lunch Box */
2164         case 0x11: /* Main Server Chassis */
2165                 return true;
2166         }
2167
2168         return false;
2169 }
2170
2171 /*
2172  * We're seeing a lot of bogus backlight interfaces on newer machines
2173  * without a LCD such as desktops, servers and HDMI sticks. Checking the
2174  * lcd flag fixes this, enable this by default on any machines which are:
2175  * 1.  Win8 ready (where we also prefer the native backlight driver, so
2176  *     normally the acpi_video code should not register there anyways); *and*
2177  * 2.1 Report a desktop/server DMI chassis-type, or
2178  * 2.2 Are an ACPI-reduced-hardware platform (and thus won't use the EC for
2179        backlight control)
2180  */
2181 static bool should_check_lcd_flag(void)
2182 {
2183         if (!acpi_osi_is_win8())
2184                 return false;
2185
2186         if (dmi_is_desktop())
2187                 return true;
2188
2189         if (acpi_reduced_hardware())
2190                 return true;
2191
2192         return false;
2193 }
2194
2195 int acpi_video_register(void)
2196 {
2197         int ret = 0;
2198
2199         mutex_lock(&register_count_mutex);
2200         if (register_count) {
2201                 /*
2202                  * if the function of acpi_video_register is already called,
2203                  * don't register the acpi_video_bus again and return no error.
2204                  */
2205                 goto leave;
2206         }
2207
2208         if (only_lcd == -1)
2209                 only_lcd = should_check_lcd_flag();
2210
2211         dmi_check_system(video_dmi_table);
2212
2213         ret = acpi_bus_register_driver(&acpi_video_bus);
2214         if (ret)
2215                 goto leave;
2216
2217         /*
2218          * When the acpi_video_bus is loaded successfully, increase
2219          * the counter reference.
2220          */
2221         register_count = 1;
2222
2223 leave:
2224         mutex_unlock(&register_count_mutex);
2225         return ret;
2226 }
2227 EXPORT_SYMBOL(acpi_video_register);
2228
2229 void acpi_video_unregister(void)
2230 {
2231         mutex_lock(&register_count_mutex);
2232         if (register_count) {
2233                 acpi_bus_unregister_driver(&acpi_video_bus);
2234                 register_count = 0;
2235                 may_report_brightness_keys = false;
2236         }
2237         mutex_unlock(&register_count_mutex);
2238 }
2239 EXPORT_SYMBOL(acpi_video_unregister);
2240
2241 void acpi_video_register_backlight(void)
2242 {
2243         struct acpi_video_bus *video;
2244
2245         mutex_lock(&video_list_lock);
2246         list_for_each_entry(video, &video_bus_head, entry)
2247                 acpi_video_bus_register_backlight(video);
2248         mutex_unlock(&video_list_lock);
2249 }
2250 EXPORT_SYMBOL(acpi_video_register_backlight);
2251
2252 bool acpi_video_handles_brightness_key_presses(void)
2253 {
2254         return may_report_brightness_keys &&
2255                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2256 }
2257 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2258
2259 /*
2260  * This is kind of nasty. Hardware using Intel chipsets may require
2261  * the video opregion code to be run first in order to initialise
2262  * state before any ACPI video calls are made. To handle this we defer
2263  * registration of the video class until the opregion code has run.
2264  */
2265
2266 static int __init acpi_video_init(void)
2267 {
2268         /*
2269          * Let the module load even if ACPI is disabled (e.g. due to
2270          * a broken BIOS) so that i915.ko can still be loaded on such
2271          * old systems without an AcpiOpRegion.
2272          *
2273          * acpi_video_register() will report -ENODEV later as well due
2274          * to acpi_disabled when i915.ko tries to register itself afterwards.
2275          */
2276         if (acpi_disabled)
2277                 return 0;
2278
2279         if (intel_opregion_present())
2280                 return 0;
2281
2282         return acpi_video_register();
2283 }
2284
2285 static void __exit acpi_video_exit(void)
2286 {
2287         acpi_video_unregister();
2288 }
2289
2290 module_init(acpi_video_init);
2291 module_exit(acpi_video_exit);