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