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_video_device *video = cooling_dev->devdata;
 257
 258         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 259         return 0;
 260 }
 261
 262 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 263                                unsigned long *state)
 264 {
 265         struct acpi_video_device *video = cooling_dev->devdata;
 266         unsigned long long level;
 267         int offset;
 268
 269         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 270                 return -EINVAL;
 271         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 272              offset++)
 273                 if (level == video->brightness->levels[offset]) {
 274                         *state = video->brightness->count - offset - 1;
 275                         return 0;
 276                 }
 277
 278         return -EINVAL;
 279 }
 280
 281 static int
 282 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 283 {
 284         struct acpi_video_device *video = cooling_dev->devdata;
 285         int level;
 286
 287         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 288                 return -EINVAL;
 289
 290         state = video->brightness->count - state;
 291         level = video->brightness->levels[state - 1];
 292         return acpi_video_device_lcd_set_level(video, level);
 293 }
 294
 295 static const struct thermal_cooling_device_ops video_cooling_ops = {
 296         .get_max_state = video_get_max_state,
 297         .get_cur_state = video_get_cur_state,
 298         .set_cur_state = video_set_cur_state,
 299 };
 300
 301 /*
 302  * --------------------------------------------------------------------------
 303  *                             Video Management
 304  * --------------------------------------------------------------------------
 305  */
 306
 307 static int
 308 acpi_video_device_lcd_query_levels(acpi_handle handle,
 309                                    union acpi_object **levels)
 310 {
 311         int status;
 312         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 313         union acpi_object *obj;
 314
 315
 316         *levels = NULL;
 317
 318         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 319         if (ACPI_FAILURE(status))
 320                 return status;
 321         obj = (union acpi_object *)buffer.pointer;
 322         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 323                 acpi_handle_info(handle, "Invalid _BCL data\n");
 324                 status = -EFAULT;
 325                 goto err;
 326         }
 327
 328         *levels = obj;
 329
 330         return 0;
 331
 332 err:
 333         kfree(buffer.pointer);
 334
 335         return status;
 336 }
 337
 338 static int
 339 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 340 {
 341         int status;
 342         int state;
 343
 344         status = acpi_execute_simple_method(device->dev->handle,
 345                                             "_BCM", level);
 346         if (ACPI_FAILURE(status)) {
 347                 acpi_handle_info(device->dev->handle, "_BCM evaluation failed\n");
 348                 return -EIO;
 349         }
 350
 351         device->brightness->curr = level;
 352         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 353              state++)
 354                 if (level == device->brightness->levels[state]) {
 355                         if (device->backlight)
 356                                 device->backlight->props.brightness =
 357                                         state - ACPI_VIDEO_FIRST_LEVEL;
 358                         return 0;
 359                 }
 360
 361         acpi_handle_info(device->dev->handle, "Current brightness invalid\n");
 362         return -EINVAL;
 363 }
 364
 365 /*
 366  * For some buggy _BQC methods, we need to add a constant value to
 367  * the _BQC return value to get the actual current brightness level
 368  */
 369
 370 static int bqc_offset_aml_bug_workaround;
 371 static int video_set_bqc_offset(const struct dmi_system_id *d)
 372 {
 373         bqc_offset_aml_bug_workaround = 9;
 374         return 0;
 375 }
 376
 377 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 378 {
 379         device_id_scheme = true;
 380         return 0;
 381 }
 382
 383 static int video_enable_only_lcd(const struct dmi_system_id *d)
 384 {
 385         only_lcd = true;
 386         return 0;
 387 }
 388
 389 static int video_set_report_key_events(const struct dmi_system_id *id)
 390 {
 391         if (report_key_events == -1)
 392                 report_key_events = (uintptr_t)id->driver_data;
 393         return 0;
 394 }
 395
 396 static int video_hw_changes_brightness(
 397         const struct dmi_system_id *d)
 398 {
 399         if (hw_changes_brightness == -1)
 400                 hw_changes_brightness = 1;
 401         return 0;
 402 }
 403
 404 static const struct dmi_system_id video_dmi_table[] = {
 405         /*
 406          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 407          */
 408         {
 409          .callback = video_set_bqc_offset,
 410          .ident = "Acer Aspire 5720",
 411          .matches = {
 412                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 413                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 414                 },
 415         },
 416         {
 417          .callback = video_set_bqc_offset,
 418          .ident = "Acer Aspire 5710Z",
 419          .matches = {
 420                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 421                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 422                 },
 423         },
 424         {
 425          .callback = video_set_bqc_offset,
 426          .ident = "eMachines E510",
 427          .matches = {
 428                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 429                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 430                 },
 431         },
 432         {
 433          .callback = video_set_bqc_offset,
 434          .ident = "Acer Aspire 5315",
 435          .matches = {
 436                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 437                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 438                 },
 439         },
 440         {
 441          .callback = video_set_bqc_offset,
 442          .ident = "Acer Aspire 7720",
 443          .matches = {
 444                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 445                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 446                 },
 447         },
 448
 449         /*
 450          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 451          * but the IDs actually follow the Device ID Scheme.
 452          */
 453         {
 454          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 455          .callback = video_set_device_id_scheme,
 456          .ident = "ESPRIMO Mobile M9410",
 457          .matches = {
 458                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 459                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 460                 },
 461         },
 462         /*
 463          * Some machines have multiple video output devices, but only the one
 464          * that is the type of LCD can do the backlight control so we should not
 465          * register backlight interface for other video output devices.
 466          */
 467         {
 468          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 469          .callback = video_enable_only_lcd,
 470          .ident = "ESPRIMO Mobile M9410",
 471          .matches = {
 472                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 473                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 474                 },
 475         },
 476         /*
 477          * Some machines report wrong key events on the acpi-bus, suppress
 478          * key event reporting on these.  Note this is only intended to work
 479          * around events which are plain wrong. In some cases we get double
 480          * events, in this case acpi-video is considered the canonical source
 481          * and the events from the other source should be filtered. E.g.
 482          * by calling acpi_video_handles_brightness_key_presses() from the
 483          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 484          */
 485         {
 486          .callback = video_set_report_key_events,
 487          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 488          .ident = "Dell Vostro V131",
 489          .matches = {
 490                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 491                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 492                 },
 493         },
 494         {
 495          .callback = video_set_report_key_events,
 496          .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 497          .ident = "Dell Vostro 3350",
 498          .matches = {
 499                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 500                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3350"),
 501                 },
 502         },
 503         {
 504          .callback = video_set_report_key_events,
 505          .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 506          .ident = "COLORFUL X15 AT 23",
 507          .matches = {
 508                 DMI_MATCH(DMI_SYS_VENDOR, "COLORFUL"),
 509                 DMI_MATCH(DMI_PRODUCT_NAME, "X15 AT 23"),
 510                 },
 511         },
 512         /*
 513          * Some machines change the brightness themselves when a brightness
 514          * hotkey gets pressed, despite us telling them not to. In this case
 515          * acpi_video_device_notify() should only call backlight_force_update(
 516          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 517          */
 518         {
 519          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 520          .callback = video_hw_changes_brightness,
 521          .ident = "Packard Bell EasyNote MZ35",
 522          .matches = {
 523                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 524                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 525                 },
 526         },
 527         {}
 528 };
 529
 530 static unsigned long long
 531 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 532                               unsigned long long bqc_value)
 533 {
 534         unsigned long long level;
 535
 536         if (device->brightness->flags._BQC_use_index) {
 537                 /*
 538                  * _BQC returns an index that doesn't account for the first 2
 539                  * items with special meaning (see enum acpi_video_level_idx),
 540                  * so we need to compensate for that by offsetting ourselves
 541                  */
 542                 if (device->brightness->flags._BCL_reversed)
 543                         bqc_value = device->brightness->count -
 544                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 545
 546                 level = device->brightness->levels[bqc_value +
 547                                                    ACPI_VIDEO_FIRST_LEVEL];
 548         } else {
 549                 level = bqc_value;
 550         }
 551
 552         level += bqc_offset_aml_bug_workaround;
 553
 554         return level;
 555 }
 556
 557 static int
 558 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 559                                         unsigned long long *level, bool raw)
 560 {
 561         acpi_status status = AE_OK;
 562         int i;
 563
 564         if (device->cap._BQC || device->cap._BCQ) {
 565                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 566
 567                 status = acpi_evaluate_integer(device->dev->handle, buf,
 568                                                 NULL, level);
 569                 if (ACPI_SUCCESS(status)) {
 570                         if (raw) {
 571                                 /*
 572                                  * Caller has indicated he wants the raw
 573                                  * value returned by _BQC, so don't furtherly
 574                                  * mess with the value.
 575                                  */
 576                                 return 0;
 577                         }
 578
 579                         *level = acpi_video_bqc_value_to_level(device, *level);
 580
 581                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 582                              i < device->brightness->count; i++)
 583                                 if (device->brightness->levels[i] == *level) {
 584                                         device->brightness->curr = *level;
 585                                         return 0;
 586                                 }
 587                         /*
 588                          * BQC returned an invalid level.
 589                          * Stop using it.
 590                          */
 591                         acpi_handle_info(device->dev->handle,
 592                                          "%s returned an invalid level", buf);
 593                         device->cap._BQC = device->cap._BCQ = 0;
 594                 } else {
 595                         /*
 596                          * Fixme:
 597                          * should we return an error or ignore this failure?
 598                          * dev->brightness->curr is a cached value which stores
 599                          * the correct current backlight level in most cases.
 600                          * ACPI video backlight still works w/ buggy _BQC.
 601                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 602                          */
 603                         acpi_handle_info(device->dev->handle,
 604                                          "%s evaluation failed", buf);
 605                         device->cap._BQC = device->cap._BCQ = 0;
 606                 }
 607         }
 608
 609         *level = device->brightness->curr;
 610         return 0;
 611 }
 612
 613 static int
 614 acpi_video_device_EDID(struct acpi_video_device *device,
 615                        union acpi_object **edid, ssize_t length)
 616 {
 617         int status;
 618         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 619         union acpi_object *obj;
 620         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 621         struct acpi_object_list args = { 1, &arg0 };
 622
 623
 624         *edid = NULL;
 625
 626         if (!device)
 627                 return -ENODEV;
 628         if (length == 128)
 629                 arg0.integer.value = 1;
 630         else if (length == 256)
 631                 arg0.integer.value = 2;
 632         else
 633                 return -EINVAL;
 634
 635         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 636         if (ACPI_FAILURE(status))
 637                 return -ENODEV;
 638
 639         obj = buffer.pointer;
 640
 641         if (obj && obj->type == ACPI_TYPE_BUFFER)
 642                 *edid = obj;
 643         else {
 644                 acpi_handle_info(device->dev->handle, "Invalid _DDC data\n");
 645                 status = -EFAULT;
 646                 kfree(obj);
 647         }
 648
 649         return status;
 650 }
 651
 652 /* bus */
 653
 654 /*
 655  *  Arg:
 656  *      video           : video bus device pointer
 657  *      bios_flag       :
 658  *              0.      The system BIOS should NOT automatically switch(toggle)
 659  *                      the active display output.
 660  *              1.      The system BIOS should automatically switch (toggle) the
 661  *                      active display output. No switch event.
 662  *              2.      The _DGS value should be locked.
 663  *              3.      The system BIOS should not automatically switch (toggle) the
 664  *                      active display output, but instead generate the display switch
 665  *                      event notify code.
 666  *      lcd_flag        :
 667  *              0.      The system BIOS should automatically control the brightness level
 668  *                      of the LCD when:
 669  *                      - the power changes from AC to DC (ACPI appendix B)
 670  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 671  *              1.      The system BIOS should NOT automatically control the brightness
 672  *                      level of the LCD when:
 673  *                      - the power changes from AC to DC (ACPI appendix B)
 674  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 675  *  Return Value:
 676  *              -EINVAL wrong arg.
 677  */
 678
 679 static int
 680 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 681 {
 682         acpi_status status;
 683
 684         if (!video->cap._DOS)
 685                 return 0;
 686
 687         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 688                 return -EINVAL;
 689         video->dos_setting = (lcd_flag << 2) | bios_flag;
 690         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 691                                             (lcd_flag << 2) | bios_flag);
 692         if (ACPI_FAILURE(status))
 693                 return -EIO;
 694
 695         return 0;
 696 }
 697
 698 /*
 699  * Simple comparison function used to sort backlight levels.
 700  */
 701
 702 static int
 703 acpi_video_cmp_level(const void *a, const void *b)
 704 {
 705         return *(int *)a - *(int *)b;
 706 }
 707
 708 /*
 709  * Decides if _BQC/_BCQ for this system is usable
 710  *
 711  * We do this by changing the level first and then read out the current
 712  * brightness level, if the value does not match, find out if it is using
 713  * index. If not, clear the _BQC/_BCQ capability.
 714  */
 715 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 716                                 int max_level, int current_level)
 717 {
 718         struct acpi_video_device_brightness *br = device->brightness;
 719         int result;
 720         unsigned long long level;
 721         int test_level;
 722
 723         /* don't mess with existing known broken systems */
 724         if (bqc_offset_aml_bug_workaround)
 725                 return 0;
 726
 727         /*
 728          * Some systems always report current brightness level as maximum
 729          * through _BQC, we need to test another value for them. However,
 730          * there is a subtlety:
 731          *
 732          * If the _BCL package ordering is descending, the first level
 733          * (br->levels[2]) is likely to be 0, and if the number of levels
 734          * matches the number of steps, we might confuse a returned level to
 735          * mean the index.
 736          *
 737          * For example:
 738          *
 739          *     current_level = max_level = 100
 740          *     test_level = 0
 741          *     returned level = 100
 742          *
 743          * In this case 100 means the level, not the index, and _BCM failed.
 744          * Still, if the _BCL package ordering is descending, the index of
 745          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 746          *
 747          * This causes all _BQC calls to return bogus values causing weird
 748          * behavior from the user's perspective.  For example:
 749          *
 750          * xbacklight -set 10; xbacklight -set 20;
 751          *
 752          * would flash to 90% and then slowly down to the desired level (20).
 753          *
 754          * The solution is simple; test anything other than the first level
 755          * (e.g. 1).
 756          */
 757         test_level = current_level == max_level
 758                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 759                 : max_level;
 760
 761         result = acpi_video_device_lcd_set_level(device, test_level);
 762         if (result)
 763                 return result;
 764
 765         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 766         if (result)
 767                 return result;
 768
 769         if (level != test_level) {
 770                 /* buggy _BQC found, need to find out if it uses index */
 771                 if (level < br->count) {
 772                         if (br->flags._BCL_reversed)
 773                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 774                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 775                                 br->flags._BQC_use_index = 1;
 776                 }
 777
 778                 if (!br->flags._BQC_use_index)
 779                         device->cap._BQC = device->cap._BCQ = 0;
 780         }
 781
 782         return 0;
 783 }
 784
 785 int acpi_video_get_levels(struct acpi_device *device,
 786                           struct acpi_video_device_brightness **dev_br,
 787                           int *pmax_level)
 788 {
 789         union acpi_object *obj = NULL;
 790         int i, max_level = 0, count = 0, level_ac_battery = 0;
 791         union acpi_object *o;
 792         struct acpi_video_device_brightness *br = NULL;
 793         int result = 0;
 794         u32 value;
 795
 796         if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
 797                 acpi_handle_debug(device->handle,
 798                                   "Could not query available LCD brightness level\n");
 799                 result = -ENODEV;
 800                 goto out;
 801         }
 802
 803         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 804                 result = -EINVAL;
 805                 goto out;
 806         }
 807
 808         br = kzalloc(sizeof(*br), GFP_KERNEL);
 809         if (!br) {
 810                 result = -ENOMEM;
 811                 goto out;
 812         }
 813
 814         /*
 815          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 816          * in order to account for buggy BIOS which don't export the first two
 817          * special levels (see below)
 818          */
 819         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 820                                    sizeof(*br->levels),
 821                                    GFP_KERNEL);
 822         if (!br->levels) {
 823                 result = -ENOMEM;
 824                 goto out_free;
 825         }
 826
 827         for (i = 0; i < obj->package.count; i++) {
 828                 o = (union acpi_object *)&obj->package.elements[i];
 829                 if (o->type != ACPI_TYPE_INTEGER) {
 830                         acpi_handle_info(device->handle, "Invalid data\n");
 831                         continue;
 832                 }
 833                 value = (u32) o->integer.value;
 834                 /* Skip duplicate entries */
 835                 if (count > ACPI_VIDEO_FIRST_LEVEL
 836                     && br->levels[count - 1] == value)
 837                         continue;
 838
 839                 br->levels[count] = value;
 840
 841                 if (br->levels[count] > max_level)
 842                         max_level = br->levels[count];
 843                 count++;
 844         }
 845
 846         /*
 847          * some buggy BIOS don't export the levels
 848          * when machine is on AC/Battery in _BCL package.
 849          * In this case, the first two elements in _BCL packages
 850          * are also supported brightness levels that OS should take care of.
 851          */
 852         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 853                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 854                         level_ac_battery++;
 855                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 856                         level_ac_battery++;
 857         }
 858
 859         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 860                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 861                 br->flags._BCL_no_ac_battery_levels = 1;
 862                 for (i = (count - 1 + level_ac_battery);
 863                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 864                         br->levels[i] = br->levels[i - level_ac_battery];
 865                 count += level_ac_battery;
 866         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 867                 acpi_handle_info(device->handle,
 868                                  "Too many duplicates in _BCL package");
 869
 870         /* Check if the _BCL package is in a reversed order */
 871         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 872                 br->flags._BCL_reversed = 1;
 873                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 874                      count - ACPI_VIDEO_FIRST_LEVEL,
 875                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 876                      acpi_video_cmp_level, NULL);
 877         } else if (max_level != br->levels[count - 1])
 878                 acpi_handle_info(device->handle,
 879                                  "Found unordered _BCL package");
 880
 881         br->count = count;
 882         *dev_br = br;
 883         if (pmax_level)
 884                 *pmax_level = max_level;
 885
 886 out:
 887         kfree(obj);
 888         return result;
 889 out_free:
 890         kfree(br);
 891         goto out;
 892 }
 893 EXPORT_SYMBOL(acpi_video_get_levels);
 894
 895 /*
 896  *  Arg:
 897  *      device  : video output device (LCD, CRT, ..)
 898  *
 899  *  Return Value:
 900  *      Maximum brightness level
 901  *
 902  *  Allocate and initialize device->brightness.
 903  */
 904
 905 static int
 906 acpi_video_init_brightness(struct acpi_video_device *device)
 907 {
 908         int i, max_level = 0;
 909         unsigned long long level, level_old;
 910         struct acpi_video_device_brightness *br = NULL;
 911         int result;
 912
 913         result = acpi_video_get_levels(device->dev, &br, &max_level);
 914         if (result)
 915                 return result;
 916         device->brightness = br;
 917
 918         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 919         br->curr = level = max_level;
 920
 921         if (!device->cap._BQC)
 922                 goto set_level;
 923
 924         result = acpi_video_device_lcd_get_level_current(device,
 925                                                          &level_old, true);
 926         if (result)
 927                 goto out_free_levels;
 928
 929         result = acpi_video_bqc_quirk(device, max_level, level_old);
 930         if (result)
 931                 goto out_free_levels;
 932         /*
 933          * cap._BQC may get cleared due to _BQC is found to be broken
 934          * in acpi_video_bqc_quirk, so check again here.
 935          */
 936         if (!device->cap._BQC)
 937                 goto set_level;
 938
 939         level = acpi_video_bqc_value_to_level(device, level_old);
 940         /*
 941          * On some buggy laptops, _BQC returns an uninitialized
 942          * value when invoked for the first time, i.e.
 943          * level_old is invalid (no matter whether it's a level
 944          * or an index). Set the backlight to max_level in this case.
 945          */
 946         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 947                 if (level == br->levels[i])
 948                         break;
 949         if (i == br->count || !level)
 950                 level = max_level;
 951
 952 set_level:
 953         result = acpi_video_device_lcd_set_level(device, level);
 954         if (result)
 955                 goto out_free_levels;
 956
 957         acpi_handle_debug(device->dev->handle, "found %d brightness levels\n",
 958                           br->count - ACPI_VIDEO_FIRST_LEVEL);
 959
 960         return 0;
 961
 962 out_free_levels:
 963         kfree(br->levels);
 964         kfree(br);
 965         device->brightness = NULL;
 966         return result;
 967 }
 968
 969 /*
 970  *  Arg:
 971  *      device  : video output device (LCD, CRT, ..)
 972  *
 973  *  Return Value:
 974  *      None
 975  *
 976  *  Find out all required AML methods defined under the output
 977  *  device.
 978  */
 979
 980 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 981 {
 982         if (acpi_has_method(device->dev->handle, "_ADR"))
 983                 device->cap._ADR = 1;
 984         if (acpi_has_method(device->dev->handle, "_BCL"))
 985                 device->cap._BCL = 1;
 986         if (acpi_has_method(device->dev->handle, "_BCM"))
 987                 device->cap._BCM = 1;
 988         if (acpi_has_method(device->dev->handle, "_BQC")) {
 989                 device->cap._BQC = 1;
 990         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 991                 acpi_handle_info(device->dev->handle,
 992                                  "_BCQ is used instead of _BQC\n");
 993                 device->cap._BCQ = 1;
 994         }
 995
 996         if (acpi_has_method(device->dev->handle, "_DDC"))
 997                 device->cap._DDC = 1;
 998 }
 999
1000 /*
1001  *  Arg:
1002  *      device  : video output device (VGA)
1003  *
1004  *  Return Value:
1005  *      None
1006  *
1007  *  Find out all required AML methods defined under the video bus device.
1008  */
1009
1010 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1011 {
1012         if (acpi_has_method(video->device->handle, "_DOS"))
1013                 video->cap._DOS = 1;
1014         if (acpi_has_method(video->device->handle, "_DOD"))
1015                 video->cap._DOD = 1;
1016         if (acpi_has_method(video->device->handle, "_ROM"))
1017                 video->cap._ROM = 1;
1018         if (acpi_has_method(video->device->handle, "_GPD"))
1019                 video->cap._GPD = 1;
1020         if (acpi_has_method(video->device->handle, "_SPD"))
1021                 video->cap._SPD = 1;
1022         if (acpi_has_method(video->device->handle, "_VPO"))
1023                 video->cap._VPO = 1;
1024 }
1025
1026 /*
1027  * Check whether the video bus device has required AML method to
1028  * support the desired features
1029  */
1030
1031 static int acpi_video_bus_check(struct acpi_video_bus *video)
1032 {
1033         acpi_status status = -ENOENT;
1034         struct pci_dev *dev;
1035
1036         if (!video)
1037                 return -EINVAL;
1038
1039         dev = acpi_get_pci_dev(video->device->handle);
1040         if (!dev)
1041                 return -ENODEV;
1042         pci_dev_put(dev);
1043
1044         /*
1045          * Since there is no HID, CID and so on for VGA driver, we have
1046          * to check well known required nodes.
1047          */
1048
1049         /* Does this device support video switching? */
1050         if (video->cap._DOS || video->cap._DOD) {
1051                 if (!video->cap._DOS) {
1052                         pr_info(FW_BUG "ACPI(%s) defines _DOD but not _DOS\n",
1053                                 acpi_device_bid(video->device));
1054                 }
1055                 video->flags.multihead = 1;
1056                 status = 0;
1057         }
1058
1059         /* Does this device support retrieving a video ROM? */
1060         if (video->cap._ROM) {
1061                 video->flags.rom = 1;
1062                 status = 0;
1063         }
1064
1065         /* Does this device support configuring which video device to POST? */
1066         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1067                 video->flags.post = 1;
1068                 status = 0;
1069         }
1070
1071         return status;
1072 }
1073
1074 /*
1075  * --------------------------------------------------------------------------
1076  *                               Driver Interface
1077  * --------------------------------------------------------------------------
1078  */
1079
1080 /* device interface */
1081 static struct acpi_video_device_attrib *
1082 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1083 {
1084         struct acpi_video_enumerated_device *ids;
1085         int i;
1086
1087         for (i = 0; i < video->attached_count; i++) {
1088                 ids = &video->attached_array[i];
1089                 if ((ids->value.int_val & 0xffff) == device_id)
1090                         return &ids->value.attrib;
1091         }
1092
1093         return NULL;
1094 }
1095
1096 static int
1097 acpi_video_get_device_type(struct acpi_video_bus *video,
1098                            unsigned long device_id)
1099 {
1100         struct acpi_video_enumerated_device *ids;
1101         int i;
1102
1103         for (i = 0; i < video->attached_count; i++) {
1104                 ids = &video->attached_array[i];
1105                 if ((ids->value.int_val & 0xffff) == device_id)
1106                         return ids->value.int_val;
1107         }
1108
1109         return 0;
1110 }
1111
1112 static int acpi_video_bus_get_one_device(struct acpi_device *device, void *arg)
1113 {
1114         struct acpi_video_bus *video = arg;
1115         struct acpi_video_device_attrib *attribute;
1116         struct acpi_video_device *data;
1117         unsigned long long device_id;
1118         acpi_status status;
1119         int device_type;
1120
1121         status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1122         /* Skip devices without _ADR instead of failing. */
1123         if (ACPI_FAILURE(status))
1124                 goto exit;
1125
1126         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1127         if (!data) {
1128                 dev_dbg(&device->dev, "Cannot attach\n");
1129                 return -ENOMEM;
1130         }
1131
1132         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1133         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1134
1135         data->device_id = device_id;
1136         data->video = video;
1137         data->dev = device;
1138         INIT_DELAYED_WORK(&data->switch_brightness_work,
1139                           acpi_video_switch_brightness);
1140
1141         attribute = acpi_video_get_device_attr(video, device_id);
1142
1143         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1144                 switch (attribute->display_type) {
1145                 case ACPI_VIDEO_DISPLAY_CRT:
1146                         data->flags.crt = 1;
1147                         break;
1148                 case ACPI_VIDEO_DISPLAY_TV:
1149                         data->flags.tvout = 1;
1150                         break;
1151                 case ACPI_VIDEO_DISPLAY_DVI:
1152                         data->flags.dvi = 1;
1153                         break;
1154                 case ACPI_VIDEO_DISPLAY_LCD:
1155                         data->flags.lcd = 1;
1156                         break;
1157                 default:
1158                         data->flags.unknown = 1;
1159                         break;
1160                 }
1161                 if (attribute->bios_can_detect)
1162                         data->flags.bios = 1;
1163         } else {
1164                 /* Check for legacy IDs */
1165                 device_type = acpi_video_get_device_type(video, device_id);
1166                 /* Ignore bits 16 and 18-20 */
1167                 switch (device_type & 0xffe2ffff) {
1168                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1169                         data->flags.crt = 1;
1170                         break;
1171                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1172                         data->flags.lcd = 1;
1173                         break;
1174                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1175                         data->flags.tvout = 1;
1176                         break;
1177                 default:
1178                         data->flags.unknown = 1;
1179                 }
1180         }
1181
1182         acpi_video_device_bind(video, data);
1183         acpi_video_device_find_cap(data);
1184
1185         if (data->cap._BCM && data->cap._BCL)
1186                 may_report_brightness_keys = true;
1187
1188         mutex_lock(&video->device_list_lock);
1189         list_add_tail(&data->entry, &video->video_device_list);
1190         mutex_unlock(&video->device_list_lock);
1191
1192 exit:
1193         video->child_count++;
1194         return 0;
1195 }
1196
1197 /*
1198  *  Arg:
1199  *      video   : video bus device
1200  *
1201  *  Return:
1202  *      none
1203  *
1204  *  Enumerate the video device list of the video bus,
1205  *  bind the ids with the corresponding video devices
1206  *  under the video bus.
1207  */
1208
1209 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1210 {
1211         struct acpi_video_device *dev;
1212
1213         mutex_lock(&video->device_list_lock);
1214
1215         list_for_each_entry(dev, &video->video_device_list, entry)
1216                 acpi_video_device_bind(video, dev);
1217
1218         mutex_unlock(&video->device_list_lock);
1219 }
1220
1221 /*
1222  *  Arg:
1223  *      video   : video bus device
1224  *      device  : video output device under the video
1225  *              bus
1226  *
1227  *  Return:
1228  *      none
1229  *
1230  *  Bind the ids with the corresponding video devices
1231  *  under the video bus.
1232  */
1233
1234 static void
1235 acpi_video_device_bind(struct acpi_video_bus *video,
1236                        struct acpi_video_device *device)
1237 {
1238         struct acpi_video_enumerated_device *ids;
1239         int i;
1240
1241         for (i = 0; i < video->attached_count; i++) {
1242                 ids = &video->attached_array[i];
1243                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1244                         ids->bind_info = device;
1245                         acpi_handle_debug(video->device->handle, "%s: %d\n",
1246                                           __func__, i);
1247                 }
1248         }
1249 }
1250
1251 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1252 {
1253         struct acpi_video_bus *video = device->video;
1254         int i;
1255
1256         /*
1257          * If we have a broken _DOD or we have more than 8 output devices
1258          * under the graphics controller node that we can't proper deal with
1259          * in the operation region code currently, no need to test.
1260          */
1261         if (!video->attached_count || video->child_count > 8)
1262                 return true;
1263
1264         for (i = 0; i < video->attached_count; i++) {
1265                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1266                     (device->device_id & 0xfff))
1267                         return true;
1268         }
1269
1270         return false;
1271 }
1272
1273 /*
1274  *  Arg:
1275  *      video   : video bus device
1276  *
1277  *  Return:
1278  *      < 0     : error
1279  *
1280  *  Call _DOD to enumerate all devices attached to display adapter
1281  *
1282  */
1283
1284 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1285 {
1286         int status;
1287         int count;
1288         int i;
1289         struct acpi_video_enumerated_device *active_list;
1290         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1291         union acpi_object *dod = NULL;
1292         union acpi_object *obj;
1293
1294         if (!video->cap._DOD)
1295                 return AE_NOT_EXIST;
1296
1297         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1298         if (ACPI_FAILURE(status)) {
1299                 acpi_handle_info(video->device->handle,
1300                                  "_DOD evaluation failed: %s\n",
1301                                  acpi_format_exception(status));
1302                 return status;
1303         }
1304
1305         dod = buffer.pointer;
1306         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1307                 acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1308                 status = -EFAULT;
1309                 goto out;
1310         }
1311
1312         acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1313                           dod->package.count);
1314
1315         active_list = kcalloc(1 + dod->package.count,
1316                               sizeof(struct acpi_video_enumerated_device),
1317                               GFP_KERNEL);
1318         if (!active_list) {
1319                 status = -ENOMEM;
1320                 goto out;
1321         }
1322
1323         count = 0;
1324         for (i = 0; i < dod->package.count; i++) {
1325                 obj = &dod->package.elements[i];
1326
1327                 if (obj->type != ACPI_TYPE_INTEGER) {
1328                         acpi_handle_info(video->device->handle,
1329                                          "Invalid _DOD data in element %d\n", i);
1330                         continue;
1331                 }
1332
1333                 active_list[count].value.int_val = obj->integer.value;
1334                 active_list[count].bind_info = NULL;
1335
1336                 acpi_handle_debug(video->device->handle,
1337                                   "_DOD element[%d] = %d\n", i,
1338                                   (int)obj->integer.value);
1339
1340                 count++;
1341         }
1342
1343         kfree(video->attached_array);
1344
1345         video->attached_array = active_list;
1346         video->attached_count = count;
1347
1348 out:
1349         kfree(buffer.pointer);
1350         return status;
1351 }
1352
1353 static int
1354 acpi_video_get_next_level(struct acpi_video_device *device,
1355                           u32 level_current, u32 event)
1356 {
1357         int min, max, min_above, max_below, i, l, delta = 255;
1358         max = max_below = 0;
1359         min = min_above = 255;
1360         /* Find closest level to level_current */
1361         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1362                 l = device->brightness->levels[i];
1363                 if (abs(l - level_current) < abs(delta)) {
1364                         delta = l - level_current;
1365                         if (!delta)
1366                                 break;
1367                 }
1368         }
1369         /* Adjust level_current to closest available level */
1370         level_current += delta;
1371         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1372                 l = device->brightness->levels[i];
1373                 if (l < min)
1374                         min = l;
1375                 if (l > max)
1376                         max = l;
1377                 if (l < min_above && l > level_current)
1378                         min_above = l;
1379                 if (l > max_below && l < level_current)
1380                         max_below = l;
1381         }
1382
1383         switch (event) {
1384         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1385                 return (level_current < max) ? min_above : min;
1386         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1387                 return (level_current < max) ? min_above : max;
1388         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1389                 return (level_current > min) ? max_below : min;
1390         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1391         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1392                 return 0;
1393         default:
1394                 return level_current;
1395         }
1396 }
1397
1398 static void
1399 acpi_video_switch_brightness(struct work_struct *work)
1400 {
1401         struct acpi_video_device *device = container_of(to_delayed_work(work),
1402                              struct acpi_video_device, switch_brightness_work);
1403         unsigned long long level_current, level_next;
1404         int event = device->switch_brightness_event;
1405         int result = -EINVAL;
1406
1407         /* no warning message if acpi_backlight=vendor or a quirk is used */
1408         if (!device->backlight)
1409                 return;
1410
1411         if (!device->brightness)
1412                 goto out;
1413
1414         result = acpi_video_device_lcd_get_level_current(device,
1415                                                          &level_current,
1416                                                          false);
1417         if (result)
1418                 goto out;
1419
1420         level_next = acpi_video_get_next_level(device, level_current, event);
1421
1422         result = acpi_video_device_lcd_set_level(device, level_next);
1423
1424         if (!result)
1425                 backlight_force_update(device->backlight,
1426                                        BACKLIGHT_UPDATE_HOTKEY);
1427
1428 out:
1429         if (result)
1430                 acpi_handle_info(device->dev->handle,
1431                                  "Failed to switch brightness\n");
1432 }
1433
1434 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1435                         void **edid)
1436 {
1437         struct acpi_video_bus *video;
1438         struct acpi_video_device *video_device;
1439         union acpi_object *buffer = NULL;
1440         acpi_status status;
1441         int i, length;
1442
1443         if (!device || !acpi_driver_data(device))
1444                 return -EINVAL;
1445
1446         video = acpi_driver_data(device);
1447
1448         for (i = 0; i < video->attached_count; i++) {
1449                 video_device = video->attached_array[i].bind_info;
1450                 length = 256;
1451
1452                 if (!video_device)
1453                         continue;
1454
1455                 if (!video_device->cap._DDC)
1456                         continue;
1457
1458                 if (type) {
1459                         switch (type) {
1460                         case ACPI_VIDEO_DISPLAY_CRT:
1461                                 if (!video_device->flags.crt)
1462                                         continue;
1463                                 break;
1464                         case ACPI_VIDEO_DISPLAY_TV:
1465                                 if (!video_device->flags.tvout)
1466                                         continue;
1467                                 break;
1468                         case ACPI_VIDEO_DISPLAY_DVI:
1469                                 if (!video_device->flags.dvi)
1470                                         continue;
1471                                 break;
1472                         case ACPI_VIDEO_DISPLAY_LCD:
1473                                 if (!video_device->flags.lcd)
1474                                         continue;
1475                                 break;
1476                         }
1477                 } else if (video_device->device_id != device_id) {
1478                         continue;
1479                 }
1480
1481                 status = acpi_video_device_EDID(video_device, &buffer, length);
1482
1483                 if (ACPI_FAILURE(status) || !buffer ||
1484                     buffer->type != ACPI_TYPE_BUFFER) {
1485                         length = 128;
1486                         status = acpi_video_device_EDID(video_device, &buffer,
1487                                                         length);
1488                         if (ACPI_FAILURE(status) || !buffer ||
1489                             buffer->type != ACPI_TYPE_BUFFER) {
1490                                 continue;
1491                         }
1492                 }
1493
1494                 *edid = buffer->buffer.pointer;
1495                 return length;
1496         }
1497
1498         return -ENODEV;
1499 }
1500 EXPORT_SYMBOL(acpi_video_get_edid);
1501
1502 static int
1503 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1504                            struct acpi_device *device)
1505 {
1506         /*
1507          * There are systems where video module known to work fine regardless
1508          * of broken _DOD and ignoring returned value here doesn't cause
1509          * any issues later.
1510          */
1511         acpi_video_device_enumerate(video);
1512
1513         return acpi_dev_for_each_child(device, acpi_video_bus_get_one_device, video);
1514 }
1515
1516 /* acpi_video interface */
1517
1518 /*
1519  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1520  * perform any automatic brightness change on receiving a notification.
1521  */
1522 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1523 {
1524         return acpi_video_bus_DOS(video, 0,
1525                                   acpi_osi_is_win8() ? 1 : 0);
1526 }
1527
1528 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1529 {
1530         return acpi_video_bus_DOS(video, 0,
1531                                   acpi_osi_is_win8() ? 0 : 1);
1532 }
1533
1534 static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data)
1535 {
1536         struct acpi_device *device = data;
1537         struct acpi_video_bus *video = acpi_driver_data(device);
1538         struct input_dev *input;
1539         int keycode = 0;
1540
1541         if (!video || !video->input)
1542                 return;
1543
1544         input = video->input;
1545
1546         switch (event) {
1547         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1548                                          * most likely via hotkey. */
1549                 keycode = KEY_SWITCHVIDEOMODE;
1550                 break;
1551
1552         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1553                                          * connector. */
1554                 acpi_video_device_enumerate(video);
1555                 acpi_video_device_rebind(video);
1556                 keycode = KEY_SWITCHVIDEOMODE;
1557                 break;
1558
1559         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1560                 keycode = KEY_SWITCHVIDEOMODE;
1561                 break;
1562         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1563                 keycode = KEY_VIDEO_NEXT;
1564                 break;
1565         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1566                 keycode = KEY_VIDEO_PREV;
1567                 break;
1568
1569         default:
1570                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1571                                   event);
1572                 break;
1573         }
1574
1575         if (acpi_notifier_call_chain(device, event, 0))
1576                 /* Something vetoed the keypress. */
1577                 keycode = 0;
1578
1579         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1580                 input_report_key(input, keycode, 1);
1581                 input_sync(input);
1582                 input_report_key(input, keycode, 0);
1583                 input_sync(input);
1584         }
1585 }
1586
1587 static void brightness_switch_event(struct acpi_video_device *video_device,
1588                                     u32 event)
1589 {
1590         if (!brightness_switch_enabled)
1591                 return;
1592
1593         video_device->switch_brightness_event = event;
1594         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1595 }
1596
1597 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1598 {
1599         struct acpi_video_device *video_device = data;
1600         struct acpi_device *device = NULL;
1601         struct acpi_video_bus *bus;
1602         struct input_dev *input;
1603         int keycode = 0;
1604
1605         if (!video_device)
1606                 return;
1607
1608         device = video_device->dev;
1609         bus = video_device->video;
1610         input = bus->input;
1611
1612         if (hw_changes_brightness > 0) {
1613                 if (video_device->backlight)
1614                         backlight_force_update(video_device->backlight,
1615                                                BACKLIGHT_UPDATE_HOTKEY);
1616                 acpi_notifier_call_chain(device, event, 0);
1617                 return;
1618         }
1619
1620         switch (event) {
1621         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1622                 brightness_switch_event(video_device, event);
1623                 keycode = KEY_BRIGHTNESS_CYCLE;
1624                 break;
1625         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1626                 brightness_switch_event(video_device, event);
1627                 keycode = KEY_BRIGHTNESSUP;
1628                 break;
1629         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1630                 brightness_switch_event(video_device, event);
1631                 keycode = KEY_BRIGHTNESSDOWN;
1632                 break;
1633         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1634                 brightness_switch_event(video_device, event);
1635                 keycode = KEY_BRIGHTNESS_ZERO;
1636                 break;
1637         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1638                 brightness_switch_event(video_device, event);
1639                 keycode = KEY_DISPLAY_OFF;
1640                 break;
1641         default:
1642                 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1643                 break;
1644         }
1645
1646         if (keycode)
1647                 may_report_brightness_keys = true;
1648
1649         acpi_notifier_call_chain(device, event, 0);
1650
1651         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1652                 input_report_key(input, keycode, 1);
1653                 input_sync(input);
1654                 input_report_key(input, keycode, 0);
1655                 input_sync(input);
1656         }
1657 }
1658
1659 static int acpi_video_resume(struct notifier_block *nb,
1660                                 unsigned long val, void *ign)
1661 {
1662         struct acpi_video_bus *video;
1663         struct acpi_video_device *video_device;
1664         int i;
1665
1666         switch (val) {
1667         case PM_POST_HIBERNATION:
1668         case PM_POST_SUSPEND:
1669         case PM_POST_RESTORE:
1670                 video = container_of(nb, struct acpi_video_bus, pm_nb);
1671
1672                 dev_info(&video->device->dev, "Restoring backlight state\n");
1673
1674                 for (i = 0; i < video->attached_count; i++) {
1675                         video_device = video->attached_array[i].bind_info;
1676                         if (video_device && video_device->brightness)
1677                                 acpi_video_device_lcd_set_level(video_device,
1678                                                 video_device->brightness->curr);
1679                 }
1680
1681                 return NOTIFY_OK;
1682         }
1683         return NOTIFY_DONE;
1684 }
1685
1686 static acpi_status
1687 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1688                         void **return_value)
1689 {
1690         struct acpi_device *device = context;
1691         struct acpi_device *sibling;
1692
1693         if (handle == device->handle)
1694                 return AE_CTRL_TERMINATE;
1695
1696         sibling = acpi_fetch_acpi_dev(handle);
1697         if (!sibling)
1698                 return AE_OK;
1699
1700         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1701                         return AE_ALREADY_EXISTS;
1702
1703         return AE_OK;
1704 }
1705
1706 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1707 {
1708         struct backlight_properties props;
1709         struct pci_dev *pdev;
1710         acpi_handle acpi_parent;
1711         struct device *parent = NULL;
1712         int result;
1713         static int count;
1714         char *name;
1715
1716         result = acpi_video_init_brightness(device);
1717         if (result)
1718                 return;
1719
1720         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1721         if (!name)
1722                 return;
1723         count++;
1724
1725         if (ACPI_SUCCESS(acpi_get_parent(device->dev->handle, &acpi_parent))) {
1726                 pdev = acpi_get_pci_dev(acpi_parent);
1727                 if (pdev) {
1728                         parent = &pdev->dev;
1729                         pci_dev_put(pdev);
1730                 }
1731         }
1732
1733         memset(&props, 0, sizeof(struct backlight_properties));
1734         props.type = BACKLIGHT_FIRMWARE;
1735         props.max_brightness =
1736                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1737         device->backlight = backlight_device_register(name,
1738                                                       parent,
1739                                                       device,
1740                                                       &acpi_backlight_ops,
1741                                                       &props);
1742         kfree(name);
1743         if (IS_ERR(device->backlight)) {
1744                 device->backlight = NULL;
1745                 return;
1746         }
1747
1748         /*
1749          * Save current brightness level in case we have to restore it
1750          * before acpi_video_device_lcd_set_level() is called next time.
1751          */
1752         device->backlight->props.brightness =
1753                         acpi_video_get_brightness(device->backlight);
1754
1755         device->cooling_dev = thermal_cooling_device_register("LCD", device,
1756                                                               &video_cooling_ops);
1757         if (IS_ERR(device->cooling_dev)) {
1758                 /*
1759                  * Set cooling_dev to NULL so we don't crash trying to free it.
1760                  * Also, why the hell we are returning early and not attempt to
1761                  * register video output if cooling device registration failed?
1762                  * -- dtor
1763                  */
1764                 device->cooling_dev = NULL;
1765                 return;
1766         }
1767
1768         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1769                  device->cooling_dev->id);
1770         result = sysfs_create_link(&device->dev->dev.kobj,
1771                         &device->cooling_dev->device.kobj,
1772                         "thermal_cooling");
1773         if (result)
1774                 pr_info("sysfs link creation failed\n");
1775
1776         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1777                         &device->dev->dev.kobj, "device");
1778         if (result)
1779                 pr_info("Reverse sysfs link creation failed\n");
1780 }
1781
1782 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1783 {
1784         struct acpi_video_device *dev;
1785         union acpi_object *levels;
1786
1787         mutex_lock(&video->device_list_lock);
1788         list_for_each_entry(dev, &video->video_device_list, entry) {
1789                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1790                         kfree(levels);
1791         }
1792         mutex_unlock(&video->device_list_lock);
1793 }
1794
1795 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1796 {
1797         /*
1798          * Do not create backlight device for video output
1799          * device that is not in the enumerated list.
1800          */
1801         if (!acpi_video_device_in_dod(dev)) {
1802                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1803                 return false;
1804         }
1805
1806         if (only_lcd)
1807                 return dev->flags.lcd;
1808         return true;
1809 }
1810
1811 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1812 {
1813         struct acpi_video_device *dev;
1814
1815         if (video->backlight_registered)
1816                 return 0;
1817
1818         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1819                 return 0;
1820
1821         mutex_lock(&video->device_list_lock);
1822         list_for_each_entry(dev, &video->video_device_list, entry) {
1823                 if (acpi_video_should_register_backlight(dev))
1824                         acpi_video_dev_register_backlight(dev);
1825         }
1826         mutex_unlock(&video->device_list_lock);
1827
1828         video->backlight_registered = true;
1829
1830         video->pm_nb.notifier_call = acpi_video_resume;
1831         video->pm_nb.priority = 0;
1832         return register_pm_notifier(&video->pm_nb);
1833 }
1834
1835 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1836 {
1837         if (device->backlight) {
1838                 backlight_device_unregister(device->backlight);
1839                 device->backlight = NULL;
1840         }
1841         if (device->brightness) {
1842                 kfree(device->brightness->levels);
1843                 kfree(device->brightness);
1844                 device->brightness = NULL;
1845         }
1846         if (device->cooling_dev) {
1847                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1848                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1849                 thermal_cooling_device_unregister(device->cooling_dev);
1850                 device->cooling_dev = NULL;
1851         }
1852 }
1853
1854 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1855 {
1856         struct acpi_video_device *dev;
1857         int error;
1858
1859         if (!video->backlight_registered)
1860                 return 0;
1861
1862         error = unregister_pm_notifier(&video->pm_nb);
1863
1864         mutex_lock(&video->device_list_lock);
1865         list_for_each_entry(dev, &video->video_device_list, entry)
1866                 acpi_video_dev_unregister_backlight(dev);
1867         mutex_unlock(&video->device_list_lock);
1868
1869         video->backlight_registered = false;
1870
1871         return error;
1872 }
1873
1874 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1875 {
1876         acpi_status status;
1877         struct acpi_device *adev = device->dev;
1878
1879         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1880                                              acpi_video_device_notify, device);
1881         if (ACPI_FAILURE(status))
1882                 dev_err(&adev->dev, "Error installing notify handler\n");
1883         else
1884                 device->flags.notify = 1;
1885 }
1886
1887 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1888 {
1889         struct input_dev *input;
1890         struct acpi_video_device *dev;
1891         int error;
1892
1893         video->input = input = input_allocate_device();
1894         if (!input) {
1895                 error = -ENOMEM;
1896                 goto out;
1897         }
1898
1899         error = acpi_video_bus_start_devices(video);
1900         if (error)
1901                 goto err_free_input;
1902
1903         snprintf(video->phys, sizeof(video->phys),
1904                         "%s/video/input0", acpi_device_hid(video->device));
1905
1906         input->name = acpi_device_name(video->device);
1907         input->phys = video->phys;
1908         input->id.bustype = BUS_HOST;
1909         input->id.product = 0x06;
1910         input->dev.parent = &video->device->dev;
1911         input->evbit[0] = BIT(EV_KEY);
1912         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1913         set_bit(KEY_VIDEO_NEXT, input->keybit);
1914         set_bit(KEY_VIDEO_PREV, input->keybit);
1915         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1916         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1917         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1918         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1919         set_bit(KEY_DISPLAY_OFF, input->keybit);
1920
1921         error = input_register_device(input);
1922         if (error)
1923                 goto err_stop_dev;
1924
1925         mutex_lock(&video->device_list_lock);
1926         list_for_each_entry(dev, &video->video_device_list, entry)
1927                 acpi_video_dev_add_notify_handler(dev);
1928         mutex_unlock(&video->device_list_lock);
1929
1930         return 0;
1931
1932 err_stop_dev:
1933         acpi_video_bus_stop_devices(video);
1934 err_free_input:
1935         input_free_device(input);
1936         video->input = NULL;
1937 out:
1938         return error;
1939 }
1940
1941 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1942 {
1943         if (dev->flags.notify) {
1944                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1945                                            acpi_video_device_notify);
1946                 dev->flags.notify = 0;
1947         }
1948 }
1949
1950 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1951 {
1952         struct acpi_video_device *dev;
1953
1954         mutex_lock(&video->device_list_lock);
1955         list_for_each_entry(dev, &video->video_device_list, entry)
1956                 acpi_video_dev_remove_notify_handler(dev);
1957         mutex_unlock(&video->device_list_lock);
1958
1959         acpi_video_bus_stop_devices(video);
1960         input_unregister_device(video->input);
1961         video->input = NULL;
1962 }
1963
1964 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1965 {
1966         struct acpi_video_device *dev, *next;
1967
1968         mutex_lock(&video->device_list_lock);
1969         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1970                 list_del(&dev->entry);
1971                 kfree(dev);
1972         }
1973         mutex_unlock(&video->device_list_lock);
1974
1975         return 0;
1976 }
1977
1978 static int instance;
1979
1980 static int acpi_video_bus_add(struct acpi_device *device)
1981 {
1982         struct acpi_video_bus *video;
1983         bool auto_detect;
1984         int error;
1985         acpi_status status;
1986
1987         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1988                                 acpi_dev_parent(device)->handle, 1,
1989                                 acpi_video_bus_match, NULL,
1990                                 device, NULL);
1991         if (status == AE_ALREADY_EXISTS) {
1992                 pr_info(FW_BUG
1993                         "Duplicate ACPI video bus devices for the"
1994                         " same VGA controller, please try module "
1995                         "parameter \"video.allow_duplicates=1\""
1996                         "if the current driver doesn't work.\n");
1997                 if (!allow_duplicates)
1998                         return -ENODEV;
1999         }
2000
2001         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2002         if (!video)
2003                 return -ENOMEM;
2004
2005         /* a hack to fix the duplicate name "VID" problem on T61 */
2006         if (!strcmp(device->pnp.bus_id, "VID")) {
2007                 if (instance)
2008                         device->pnp.bus_id[3] = '0' + instance;
2009                 instance++;
2010         }
2011         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2012         if (!strcmp(device->pnp.bus_id, "VGA")) {
2013                 if (instance)
2014                         device->pnp.bus_id[3] = '0' + instance;
2015                 instance++;
2016         }
2017
2018         video->device = device;
2019         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2020         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2021         device->driver_data = video;
2022
2023         acpi_video_bus_find_cap(video);
2024         error = acpi_video_bus_check(video);
2025         if (error)
2026                 goto err_free_video;
2027
2028         mutex_init(&video->device_list_lock);
2029         INIT_LIST_HEAD(&video->video_device_list);
2030
2031         error = acpi_video_bus_get_devices(video, device);
2032         if (error)
2033                 goto err_put_video;
2034
2035         /*
2036          * HP ZBook Fury 16 G10 requires ACPI video's child devices have _PS0
2037          * evaluated to have functional panel brightness control.
2038          */
2039         acpi_device_fix_up_power_children(device);
2040
2041         pr_info("%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2042                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2043                video->flags.multihead ? "yes" : "no",
2044                video->flags.rom ? "yes" : "no",
2045                video->flags.post ? "yes" : "no");
2046         mutex_lock(&video_list_lock);
2047         list_add_tail(&video->entry, &video_bus_head);
2048         mutex_unlock(&video_list_lock);
2049
2050         /*
2051          * If backlight-type auto-detection is used then a native backlight may
2052          * show up later and this may change the result from video to native.
2053          * Therefor normally the userspace visible /sys/class/backlight device
2054          * gets registered separately by the GPU driver calling
2055          * acpi_video_register_backlight() when an internal panel is detected.
2056          * Register the backlight now when not using auto-detection, so that
2057          * when the kernel cmdline or DMI-quirks are used the backlight will
2058          * get registered even if acpi_video_register_backlight() is not called.
2059          */
2060         acpi_video_run_bcl_for_osi(video);
2061         if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video &&
2062             !auto_detect)
2063                 acpi_video_bus_register_backlight(video);
2064
2065         error = acpi_video_bus_add_notify_handler(video);
2066         if (error)
2067                 goto err_del;
2068
2069         error = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
2070                                                 acpi_video_bus_notify);
2071         if (error)
2072                 goto err_remove;
2073
2074         return 0;
2075
2076 err_remove:
2077         acpi_video_bus_remove_notify_handler(video);
2078 err_del:
2079         mutex_lock(&video_list_lock);
2080         list_del(&video->entry);
2081         mutex_unlock(&video_list_lock);
2082         acpi_video_bus_unregister_backlight(video);
2083 err_put_video:
2084         acpi_video_bus_put_devices(video);
2085         kfree(video->attached_array);
2086 err_free_video:
2087         kfree(video);
2088         device->driver_data = NULL;
2089
2090         return error;
2091 }
2092
2093 static void acpi_video_bus_remove(struct acpi_device *device)
2094 {
2095         struct acpi_video_bus *video = NULL;
2096
2097
2098         if (!device || !acpi_driver_data(device))
2099                 return;
2100
2101         video = acpi_driver_data(device);
2102
2103         acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
2104                                        acpi_video_bus_notify);
2105
2106         mutex_lock(&video_list_lock);
2107         list_del(&video->entry);
2108         mutex_unlock(&video_list_lock);
2109
2110         acpi_video_bus_remove_notify_handler(video);
2111         acpi_video_bus_unregister_backlight(video);
2112         acpi_video_bus_put_devices(video);
2113
2114         kfree(video->attached_array);
2115         kfree(video);
2116 }
2117
2118 static int __init is_i740(struct pci_dev *dev)
2119 {
2120         if (dev->device == 0x00D1)
2121                 return 1;
2122         if (dev->device == 0x7000)
2123                 return 1;
2124         return 0;
2125 }
2126
2127 static int __init intel_opregion_present(void)
2128 {
2129         int opregion = 0;
2130         struct pci_dev *dev = NULL;
2131         u32 address;
2132
2133         for_each_pci_dev(dev) {
2134                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2135                         continue;
2136                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2137                         continue;
2138                 /* We don't want to poke around undefined i740 registers */
2139                 if (is_i740(dev))
2140                         continue;
2141                 pci_read_config_dword(dev, 0xfc, &address);
2142                 if (!address)
2143                         continue;
2144                 opregion = 1;
2145         }
2146         return opregion;
2147 }
2148
2149 /* Check if the chassis-type indicates there is no builtin LCD panel */
2150 static bool dmi_is_desktop(void)
2151 {
2152         const char *chassis_type;
2153         unsigned long type;
2154
2155         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2156         if (!chassis_type)
2157                 return false;
2158
2159         if (kstrtoul(chassis_type, 10, &type) != 0)
2160                 return false;
2161
2162         switch (type) {
2163         case 0x03: /* Desktop */
2164         case 0x04: /* Low Profile Desktop */
2165         case 0x05: /* Pizza Box */
2166         case 0x06: /* Mini Tower */
2167         case 0x07: /* Tower */
2168         case 0x10: /* Lunch Box */
2169         case 0x11: /* Main Server Chassis */
2170                 return true;
2171         }
2172
2173         return false;
2174 }
2175
2176 /*
2177  * We're seeing a lot of bogus backlight interfaces on newer machines
2178  * without a LCD such as desktops, servers and HDMI sticks. Checking the
2179  * lcd flag fixes this, enable this by default on any machines which are:
2180  * 1.  Win8 ready (where we also prefer the native backlight driver, so
2181  *     normally the acpi_video code should not register there anyways); *and*
2182  * 2.1 Report a desktop/server DMI chassis-type, or
2183  * 2.2 Are an ACPI-reduced-hardware platform (and thus won't use the EC for
2184        backlight control)
2185  */
2186 static bool should_check_lcd_flag(void)
2187 {
2188         if (!acpi_osi_is_win8())
2189                 return false;
2190
2191         if (dmi_is_desktop())
2192                 return true;
2193
2194         if (acpi_reduced_hardware())
2195                 return true;
2196
2197         return false;
2198 }
2199
2200 int acpi_video_register(void)
2201 {
2202         int ret = 0;
2203
2204         mutex_lock(&register_count_mutex);
2205         if (register_count) {
2206                 /*
2207                  * if the function of acpi_video_register is already called,
2208                  * don't register the acpi_video_bus again and return no error.
2209                  */
2210                 goto leave;
2211         }
2212
2213         if (only_lcd == -1)
2214                 only_lcd = should_check_lcd_flag();
2215
2216         dmi_check_system(video_dmi_table);
2217
2218         ret = acpi_bus_register_driver(&acpi_video_bus);
2219         if (ret)
2220                 goto leave;
2221
2222         /*
2223          * When the acpi_video_bus is loaded successfully, increase
2224          * the counter reference.
2225          */
2226         register_count = 1;
2227
2228 leave:
2229         mutex_unlock(&register_count_mutex);
2230         return ret;
2231 }
2232 EXPORT_SYMBOL(acpi_video_register);
2233
2234 void acpi_video_unregister(void)
2235 {
2236         mutex_lock(&register_count_mutex);
2237         if (register_count) {
2238                 acpi_bus_unregister_driver(&acpi_video_bus);
2239                 register_count = 0;
2240                 may_report_brightness_keys = false;
2241         }
2242         mutex_unlock(&register_count_mutex);
2243 }
2244 EXPORT_SYMBOL(acpi_video_unregister);
2245
2246 void acpi_video_register_backlight(void)
2247 {
2248         struct acpi_video_bus *video;
2249
2250         mutex_lock(&video_list_lock);
2251         list_for_each_entry(video, &video_bus_head, entry)
2252                 acpi_video_bus_register_backlight(video);
2253         mutex_unlock(&video_list_lock);
2254 }
2255 EXPORT_SYMBOL(acpi_video_register_backlight);
2256
2257 bool acpi_video_handles_brightness_key_presses(void)
2258 {
2259         return may_report_brightness_keys &&
2260                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2261 }
2262 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2263
2264 /*
2265  * This is kind of nasty. Hardware using Intel chipsets may require
2266  * the video opregion code to be run first in order to initialise
2267  * state before any ACPI video calls are made. To handle this we defer
2268  * registration of the video class until the opregion code has run.
2269  */
2270
2271 static int __init acpi_video_init(void)
2272 {
2273         /*
2274          * Let the module load even if ACPI is disabled (e.g. due to
2275          * a broken BIOS) so that i915.ko can still be loaded on such
2276          * old systems without an AcpiOpRegion.
2277          *
2278          * acpi_video_register() will report -ENODEV later as well due
2279          * to acpi_disabled when i915.ko tries to register itself afterwards.
2280          */
2281         if (acpi_disabled)
2282                 return 0;
2283
2284         if (intel_opregion_present())
2285                 return 0;
2286
2287         return acpi_video_register();
2288 }
2289
2290 static void __exit acpi_video_exit(void)
2291 {
2292         acpi_video_unregister();
2293 }
2294
2295 module_init(acpi_video_init);
2296 module_exit(acpi_video_exit);