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 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/types.h>
  14 #include <linux/list.h>
  15 #include <linux/mutex.h>
  16 #include <linux/input.h>
  17 #include <linux/backlight.h>
  18 #include <linux/thermal.h>
  19 #include <linux/sort.h>
  20 #include <linux/pci.h>
  21 #include <linux/pci_ids.h>
  22 #include <linux/slab.h>
  23 #include <linux/dmi.h>
  24 #include <linux/suspend.h>
  25 #include <linux/acpi.h>
  26 #include <acpi/video.h>
  27 #include <linux/uaccess.h>
  28
  29 #define PREFIX "ACPI: "
  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 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  37 ACPI_MODULE_NAME("video");
  38
  39 MODULE_AUTHOR("Bruno Ducrot");
  40 MODULE_DESCRIPTION("ACPI Video Driver");
  41 MODULE_LICENSE("GPL");
  42
  43 static bool brightness_switch_enabled = true;
  44 module_param(brightness_switch_enabled, bool, 0644);
  45
  46 /*
  47  * By default, we don't allow duplicate ACPI video bus devices
  48  * under the same VGA controller
  49  */
  50 static bool allow_duplicates;
  51 module_param(allow_duplicates, bool, 0644);
  52
  53 static int disable_backlight_sysfs_if = -1;
  54 module_param(disable_backlight_sysfs_if, int, 0444);
  55
  56 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  57 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  58 static int report_key_events = -1;
  59 module_param(report_key_events, int, 0644);
  60 MODULE_PARM_DESC(report_key_events,
  61         "0: none, 1: output changes, 2: brightness changes, 3: all");
  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 int register_count;
  74 static DEFINE_MUTEX(register_count_mutex);
  75 static DEFINE_MUTEX(video_list_lock);
  76 static LIST_HEAD(video_bus_head);
  77 static int acpi_video_bus_add(struct acpi_device *device);
  78 static int acpi_video_bus_remove(struct acpi_device *device);
  79 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  80 void acpi_video_detect_exit(void);
  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                 .notify = acpi_video_bus_notify,
 108                 },
 109 };
 110
 111 struct acpi_video_bus_flags {
 112         u8 multihead:1;         /* can switch video heads */
 113         u8 rom:1;               /* can retrieve a video rom */
 114         u8 post:1;              /* can configure the head to */
 115         u8 reserved:5;
 116 };
 117
 118 struct acpi_video_bus_cap {
 119         u8 _DOS:1;              /* Enable/Disable output switching */
 120         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 121         u8 _ROM:1;              /* Get ROM Data */
 122         u8 _GPD:1;              /* Get POST Device */
 123         u8 _SPD:1;              /* Set POST Device */
 124         u8 _VPO:1;              /* Video POST Options */
 125         u8 reserved:2;
 126 };
 127
 128 struct acpi_video_device_attrib {
 129         u32 display_index:4;    /* A zero-based instance of the Display */
 130         u32 display_port_attachment:4;  /* This field differentiates the display type */
 131         u32 display_type:4;     /* Describe the specific type in use */
 132         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 133         u32 bios_can_detect:1;  /* BIOS can detect the device */
 134         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 135                                    the VGA device. */
 136         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 137         u32 reserved:10;        /* Must be 0 */
 138
 139         /*
 140          * The device ID might not actually follow the scheme described by this
 141          * struct acpi_video_device_attrib. If it does, then this bit
 142          * device_id_scheme is set; otherwise, other fields should be ignored.
 143          *
 144          * (but also see the global flag device_id_scheme)
 145          */
 146         u32 device_id_scheme:1;
 147 };
 148
 149 struct acpi_video_enumerated_device {
 150         union {
 151                 u32 int_val;
 152                 struct acpi_video_device_attrib attrib;
 153         } value;
 154         struct acpi_video_device *bind_info;
 155 };
 156
 157 struct acpi_video_bus {
 158         struct acpi_device *device;
 159         bool backlight_registered;
 160         u8 dos_setting;
 161         struct acpi_video_enumerated_device *attached_array;
 162         u8 attached_count;
 163         u8 child_count;
 164         struct acpi_video_bus_cap cap;
 165         struct acpi_video_bus_flags flags;
 166         struct list_head video_device_list;
 167         struct mutex device_list_lock;  /* protects video_device_list */
 168         struct list_head entry;
 169         struct input_dev *input;
 170         char phys[32];  /* for input device */
 171         struct notifier_block pm_nb;
 172 };
 173
 174 struct acpi_video_device_flags {
 175         u8 crt:1;
 176         u8 lcd:1;
 177         u8 tvout:1;
 178         u8 dvi:1;
 179         u8 bios:1;
 180         u8 unknown:1;
 181         u8 notify:1;
 182         u8 reserved:1;
 183 };
 184
 185 struct acpi_video_device_cap {
 186         u8 _ADR:1;              /* Return the unique ID */
 187         u8 _BCL:1;              /* Query list of brightness control levels supported */
 188         u8 _BCM:1;              /* Set the brightness level */
 189         u8 _BQC:1;              /* Get current brightness level */
 190         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 191         u8 _DDC:1;              /* Return the EDID for this device */
 192 };
 193
 194 struct acpi_video_device {
 195         unsigned long device_id;
 196         struct acpi_video_device_flags flags;
 197         struct acpi_video_device_cap cap;
 198         struct list_head entry;
 199         struct delayed_work switch_brightness_work;
 200         int switch_brightness_event;
 201         struct acpi_video_bus *video;
 202         struct acpi_device *dev;
 203         struct acpi_video_device_brightness *brightness;
 204         struct backlight_device *backlight;
 205         struct thermal_cooling_device *cooling_dev;
 206 };
 207
 208 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 209 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 210 static void acpi_video_device_bind(struct acpi_video_bus *video,
 211                                    struct acpi_video_device *device);
 212 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 213 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 214                         int level);
 215 static int acpi_video_device_lcd_get_level_current(
 216                         struct acpi_video_device *device,
 217                         unsigned long long *level, bool raw);
 218 static int acpi_video_get_next_level(struct acpi_video_device *device,
 219                                      u32 level_current, u32 event);
 220 static void acpi_video_switch_brightness(struct work_struct *work);
 221
 222 /* backlight device sysfs support */
 223 static int acpi_video_get_brightness(struct backlight_device *bd)
 224 {
 225         unsigned long long cur_level;
 226         int i;
 227         struct acpi_video_device *vd = bl_get_data(bd);
 228
 229         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 230                 return -EINVAL;
 231         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 232                 if (vd->brightness->levels[i] == cur_level)
 233                         return i - ACPI_VIDEO_FIRST_LEVEL;
 234         }
 235         return 0;
 236 }
 237
 238 static int acpi_video_set_brightness(struct backlight_device *bd)
 239 {
 240         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 241         struct acpi_video_device *vd = bl_get_data(bd);
 242
 243         cancel_delayed_work(&vd->switch_brightness_work);
 244         return acpi_video_device_lcd_set_level(vd,
 245                                 vd->brightness->levels[request_level]);
 246 }
 247
 248 static const struct backlight_ops acpi_backlight_ops = {
 249         .get_brightness = acpi_video_get_brightness,
 250         .update_status  = acpi_video_set_brightness,
 251 };
 252
 253 /* thermal cooling device callbacks */
 254 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 255                                unsigned long *state)
 256 {
 257         struct acpi_device *device = cooling_dev->devdata;
 258         struct acpi_video_device *video = acpi_driver_data(device);
 259
 260         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 261         return 0;
 262 }
 263
 264 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 265                                unsigned long *state)
 266 {
 267         struct acpi_device *device = cooling_dev->devdata;
 268         struct acpi_video_device *video = acpi_driver_data(device);
 269         unsigned long long level;
 270         int offset;
 271
 272         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 273                 return -EINVAL;
 274         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 275              offset++)
 276                 if (level == video->brightness->levels[offset]) {
 277                         *state = video->brightness->count - offset - 1;
 278                         return 0;
 279                 }
 280
 281         return -EINVAL;
 282 }
 283
 284 static int
 285 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 286 {
 287         struct acpi_device *device = cooling_dev->devdata;
 288         struct acpi_video_device *video = acpi_driver_data(device);
 289         int level;
 290
 291         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 292                 return -EINVAL;
 293
 294         state = video->brightness->count - state;
 295         level = video->brightness->levels[state - 1];
 296         return acpi_video_device_lcd_set_level(video, level);
 297 }
 298
 299 static const struct thermal_cooling_device_ops video_cooling_ops = {
 300         .get_max_state = video_get_max_state,
 301         .get_cur_state = video_get_cur_state,
 302         .set_cur_state = video_set_cur_state,
 303 };
 304
 305 /*
 306  * --------------------------------------------------------------------------
 307  *                             Video Management
 308  * --------------------------------------------------------------------------
 309  */
 310
 311 static int
 312 acpi_video_device_lcd_query_levels(acpi_handle handle,
 313                                    union acpi_object **levels)
 314 {
 315         int status;
 316         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 317         union acpi_object *obj;
 318
 319
 320         *levels = NULL;
 321
 322         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 323         if (!ACPI_SUCCESS(status))
 324                 return status;
 325         obj = (union acpi_object *)buffer.pointer;
 326         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 327                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 328                 status = -EFAULT;
 329                 goto err;
 330         }
 331
 332         *levels = obj;
 333
 334         return 0;
 335
 336 err:
 337         kfree(buffer.pointer);
 338
 339         return status;
 340 }
 341
 342 static int
 343 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 344 {
 345         int status;
 346         int state;
 347
 348         status = acpi_execute_simple_method(device->dev->handle,
 349                                             "_BCM", level);
 350         if (ACPI_FAILURE(status)) {
 351                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 352                 return -EIO;
 353         }
 354
 355         device->brightness->curr = level;
 356         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 357              state++)
 358                 if (level == device->brightness->levels[state]) {
 359                         if (device->backlight)
 360                                 device->backlight->props.brightness =
 361                                         state - ACPI_VIDEO_FIRST_LEVEL;
 362                         return 0;
 363                 }
 364
 365         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 366         return -EINVAL;
 367 }
 368
 369 /*
 370  * For some buggy _BQC methods, we need to add a constant value to
 371  * the _BQC return value to get the actual current brightness level
 372  */
 373
 374 static int bqc_offset_aml_bug_workaround;
 375 static int video_set_bqc_offset(const struct dmi_system_id *d)
 376 {
 377         bqc_offset_aml_bug_workaround = 9;
 378         return 0;
 379 }
 380
 381 static int video_disable_backlight_sysfs_if(
 382         const struct dmi_system_id *d)
 383 {
 384         if (disable_backlight_sysfs_if == -1)
 385                 disable_backlight_sysfs_if = 1;
 386         return 0;
 387 }
 388
 389 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 390 {
 391         device_id_scheme = true;
 392         return 0;
 393 }
 394
 395 static int video_enable_only_lcd(const struct dmi_system_id *d)
 396 {
 397         only_lcd = true;
 398         return 0;
 399 }
 400
 401 static int video_set_report_key_events(const struct dmi_system_id *id)
 402 {
 403         if (report_key_events == -1)
 404                 report_key_events = (uintptr_t)id->driver_data;
 405         return 0;
 406 }
 407
 408 static const struct dmi_system_id video_dmi_table[] = {
 409         /*
 410          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 411          */
 412         {
 413          .callback = video_set_bqc_offset,
 414          .ident = "Acer Aspire 5720",
 415          .matches = {
 416                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 417                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 418                 },
 419         },
 420         {
 421          .callback = video_set_bqc_offset,
 422          .ident = "Acer Aspire 5710Z",
 423          .matches = {
 424                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 425                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 426                 },
 427         },
 428         {
 429          .callback = video_set_bqc_offset,
 430          .ident = "eMachines E510",
 431          .matches = {
 432                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 433                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 434                 },
 435         },
 436         {
 437          .callback = video_set_bqc_offset,
 438          .ident = "Acer Aspire 5315",
 439          .matches = {
 440                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 441                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 442                 },
 443         },
 444         {
 445          .callback = video_set_bqc_offset,
 446          .ident = "Acer Aspire 7720",
 447          .matches = {
 448                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 449                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 450                 },
 451         },
 452
 453         /*
 454          * Some machines have a broken acpi-video interface for brightness
 455          * control, but still need an acpi_video_device_lcd_set_level() call
 456          * on resume to turn the backlight power on.  We Enable backlight
 457          * control on these systems, but do not register a backlight sysfs
 458          * as brightness control does not work.
 459          */
 460         {
 461          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 462          .callback = video_disable_backlight_sysfs_if,
 463          .ident = "Toshiba Portege R700",
 464          .matches = {
 465                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 466                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 467                 },
 468         },
 469         {
 470          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 471          .callback = video_disable_backlight_sysfs_if,
 472          .ident = "Toshiba Portege R830",
 473          .matches = {
 474                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 475                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 476                 },
 477         },
 478         {
 479          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 480          .callback = video_disable_backlight_sysfs_if,
 481          .ident = "Toshiba Satellite R830",
 482          .matches = {
 483                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 484                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 485                 },
 486         },
 487         /*
 488          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 489          * but the IDs actually follow the Device ID Scheme.
 490          */
 491         {
 492          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 493          .callback = video_set_device_id_scheme,
 494          .ident = "ESPRIMO Mobile M9410",
 495          .matches = {
 496                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 497                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 498                 },
 499         },
 500         /*
 501          * Some machines have multiple video output devices, but only the one
 502          * that is the type of LCD can do the backlight control so we should not
 503          * register backlight interface for other video output devices.
 504          */
 505         {
 506          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 507          .callback = video_enable_only_lcd,
 508          .ident = "ESPRIMO Mobile M9410",
 509          .matches = {
 510                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 511                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 512                 },
 513         },
 514         /*
 515          * Some machines report wrong key events on the acpi-bus, suppress
 516          * key event reporting on these.  Note this is only intended to work
 517          * around events which are plain wrong. In some cases we get double
 518          * events, in this case acpi-video is considered the canonical source
 519          * and the events from the other source should be filtered. E.g.
 520          * by calling acpi_video_handles_brightness_key_presses() from the
 521          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 522          */
 523         {
 524          .callback = video_set_report_key_events,
 525          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 526          .ident = "Dell Vostro V131",
 527          .matches = {
 528                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 529                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 530                 },
 531         },
 532         {}
 533 };
 534
 535 static unsigned long long
 536 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 537                               unsigned long long bqc_value)
 538 {
 539         unsigned long long level;
 540
 541         if (device->brightness->flags._BQC_use_index) {
 542                 /*
 543                  * _BQC returns an index that doesn't account for the first 2
 544                  * items with special meaning (see enum acpi_video_level_idx),
 545                  * so we need to compensate for that by offsetting ourselves
 546                  */
 547                 if (device->brightness->flags._BCL_reversed)
 548                         bqc_value = device->brightness->count -
 549                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 550
 551                 level = device->brightness->levels[bqc_value +
 552                                                    ACPI_VIDEO_FIRST_LEVEL];
 553         } else {
 554                 level = bqc_value;
 555         }
 556
 557         level += bqc_offset_aml_bug_workaround;
 558
 559         return level;
 560 }
 561
 562 static int
 563 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 564                                         unsigned long long *level, bool raw)
 565 {
 566         acpi_status status = AE_OK;
 567         int i;
 568
 569         if (device->cap._BQC || device->cap._BCQ) {
 570                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 571
 572                 status = acpi_evaluate_integer(device->dev->handle, buf,
 573                                                 NULL, level);
 574                 if (ACPI_SUCCESS(status)) {
 575                         if (raw) {
 576                                 /*
 577                                  * Caller has indicated he wants the raw
 578                                  * value returned by _BQC, so don't furtherly
 579                                  * mess with the value.
 580                                  */
 581                                 return 0;
 582                         }
 583
 584                         *level = acpi_video_bqc_value_to_level(device, *level);
 585
 586                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 587                              i < device->brightness->count; i++)
 588                                 if (device->brightness->levels[i] == *level) {
 589                                         device->brightness->curr = *level;
 590                                         return 0;
 591                                 }
 592                         /*
 593                          * BQC returned an invalid level.
 594                          * Stop using it.
 595                          */
 596                         ACPI_WARNING((AE_INFO,
 597                                       "%s returned an invalid level",
 598                                       buf));
 599                         device->cap._BQC = device->cap._BCQ = 0;
 600                 } else {
 601                         /*
 602                          * Fixme:
 603                          * should we return an error or ignore this failure?
 604                          * dev->brightness->curr is a cached value which stores
 605                          * the correct current backlight level in most cases.
 606                          * ACPI video backlight still works w/ buggy _BQC.
 607                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 608                          */
 609                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 610                         device->cap._BQC = device->cap._BCQ = 0;
 611                 }
 612         }
 613
 614         *level = device->brightness->curr;
 615         return 0;
 616 }
 617
 618 static int
 619 acpi_video_device_EDID(struct acpi_video_device *device,
 620                        union acpi_object **edid, ssize_t length)
 621 {
 622         int status;
 623         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 624         union acpi_object *obj;
 625         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 626         struct acpi_object_list args = { 1, &arg0 };
 627
 628
 629         *edid = NULL;
 630
 631         if (!device)
 632                 return -ENODEV;
 633         if (length == 128)
 634                 arg0.integer.value = 1;
 635         else if (length == 256)
 636                 arg0.integer.value = 2;
 637         else
 638                 return -EINVAL;
 639
 640         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 641         if (ACPI_FAILURE(status))
 642                 return -ENODEV;
 643
 644         obj = buffer.pointer;
 645
 646         if (obj && obj->type == ACPI_TYPE_BUFFER)
 647                 *edid = obj;
 648         else {
 649                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 650                 status = -EFAULT;
 651                 kfree(obj);
 652         }
 653
 654         return status;
 655 }
 656
 657 /* bus */
 658
 659 /*
 660  *  Arg:
 661  *      video           : video bus device pointer
 662  *      bios_flag       :
 663  *              0.      The system BIOS should NOT automatically switch(toggle)
 664  *                      the active display output.
 665  *              1.      The system BIOS should automatically switch (toggle) the
 666  *                      active display output. No switch event.
 667  *              2.      The _DGS value should be locked.
 668  *              3.      The system BIOS should not automatically switch (toggle) the
 669  *                      active display output, but instead generate the display switch
 670  *                      event notify code.
 671  *      lcd_flag        :
 672  *              0.      The system BIOS should automatically control the brightness level
 673  *                      of the LCD when the power changes from AC to DC
 674  *              1.      The system BIOS should NOT automatically control the brightness
 675  *                      level of the LCD when the power changes from AC to DC.
 676  *  Return Value:
 677  *              -EINVAL wrong arg.
 678  */
 679
 680 static int
 681 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 682 {
 683         acpi_status status;
 684
 685         if (!video->cap._DOS)
 686                 return 0;
 687
 688         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 689                 return -EINVAL;
 690         video->dos_setting = (lcd_flag << 2) | bios_flag;
 691         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 692                                             (lcd_flag << 2) | bios_flag);
 693         if (ACPI_FAILURE(status))
 694                 return -EIO;
 695
 696         return 0;
 697 }
 698
 699 /*
 700  * Simple comparison function used to sort backlight levels.
 701  */
 702
 703 static int
 704 acpi_video_cmp_level(const void *a, const void *b)
 705 {
 706         return *(int *)a - *(int *)b;
 707 }
 708
 709 /*
 710  * Decides if _BQC/_BCQ for this system is usable
 711  *
 712  * We do this by changing the level first and then read out the current
 713  * brightness level, if the value does not match, find out if it is using
 714  * index. If not, clear the _BQC/_BCQ capability.
 715  */
 716 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 717                                 int max_level, int current_level)
 718 {
 719         struct acpi_video_device_brightness *br = device->brightness;
 720         int result;
 721         unsigned long long level;
 722         int test_level;
 723
 724         /* don't mess with existing known broken systems */
 725         if (bqc_offset_aml_bug_workaround)
 726                 return 0;
 727
 728         /*
 729          * Some systems always report current brightness level as maximum
 730          * through _BQC, we need to test another value for them. However,
 731          * there is a subtlety:
 732          *
 733          * If the _BCL package ordering is descending, the first level
 734          * (br->levels[2]) is likely to be 0, and if the number of levels
 735          * matches the number of steps, we might confuse a returned level to
 736          * mean the index.
 737          *
 738          * For example:
 739          *
 740          *     current_level = max_level = 100
 741          *     test_level = 0
 742          *     returned level = 100
 743          *
 744          * In this case 100 means the level, not the index, and _BCM failed.
 745          * Still, if the _BCL package ordering is descending, the index of
 746          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 747          *
 748          * This causes all _BQC calls to return bogus values causing weird
 749          * behavior from the user's perspective.  For example:
 750          *
 751          * xbacklight -set 10; xbacklight -set 20;
 752          *
 753          * would flash to 90% and then slowly down to the desired level (20).
 754          *
 755          * The solution is simple; test anything other than the first level
 756          * (e.g. 1).
 757          */
 758         test_level = current_level == max_level
 759                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 760                 : max_level;
 761
 762         result = acpi_video_device_lcd_set_level(device, test_level);
 763         if (result)
 764                 return result;
 765
 766         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 767         if (result)
 768                 return result;
 769
 770         if (level != test_level) {
 771                 /* buggy _BQC found, need to find out if it uses index */
 772                 if (level < br->count) {
 773                         if (br->flags._BCL_reversed)
 774                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 775                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 776                                 br->flags._BQC_use_index = 1;
 777                 }
 778
 779                 if (!br->flags._BQC_use_index)
 780                         device->cap._BQC = device->cap._BCQ = 0;
 781         }
 782
 783         return 0;
 784 }
 785
 786 int acpi_video_get_levels(struct acpi_device *device,
 787                           struct acpi_video_device_brightness **dev_br,
 788                           int *pmax_level)
 789 {
 790         union acpi_object *obj = NULL;
 791         int i, max_level = 0, count = 0, level_ac_battery = 0;
 792         union acpi_object *o;
 793         struct acpi_video_device_brightness *br = NULL;
 794         int result = 0;
 795         u32 value;
 796
 797         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device->handle,
 798                                                                 &obj))) {
 799                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 800                                                 "LCD brightness level\n"));
 801                 result = -ENODEV;
 802                 goto out;
 803         }
 804
 805         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 806                 result = -EINVAL;
 807                 goto out;
 808         }
 809
 810         br = kzalloc(sizeof(*br), GFP_KERNEL);
 811         if (!br) {
 812                 printk(KERN_ERR "can't allocate memory\n");
 813                 result = -ENOMEM;
 814                 goto out;
 815         }
 816
 817         /*
 818          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 819          * in order to account for buggy BIOS which don't export the first two
 820          * special levels (see below)
 821          */
 822         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 823                                    sizeof(*br->levels),
 824                                    GFP_KERNEL);
 825         if (!br->levels) {
 826                 result = -ENOMEM;
 827                 goto out_free;
 828         }
 829
 830         for (i = 0; i < obj->package.count; i++) {
 831                 o = (union acpi_object *)&obj->package.elements[i];
 832                 if (o->type != ACPI_TYPE_INTEGER) {
 833                         printk(KERN_ERR PREFIX "Invalid data\n");
 834                         continue;
 835                 }
 836                 value = (u32) o->integer.value;
 837                 /* Skip duplicate entries */
 838                 if (count > ACPI_VIDEO_FIRST_LEVEL
 839                     && br->levels[count - 1] == value)
 840                         continue;
 841
 842                 br->levels[count] = value;
 843
 844                 if (br->levels[count] > max_level)
 845                         max_level = br->levels[count];
 846                 count++;
 847         }
 848
 849         /*
 850          * some buggy BIOS don't export the levels
 851          * when machine is on AC/Battery in _BCL package.
 852          * In this case, the first two elements in _BCL packages
 853          * are also supported brightness levels that OS should take care of.
 854          */
 855         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 856                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 857                         level_ac_battery++;
 858                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 859                         level_ac_battery++;
 860         }
 861
 862         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 863                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 864                 br->flags._BCL_no_ac_battery_levels = 1;
 865                 for (i = (count - 1 + level_ac_battery);
 866                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 867                         br->levels[i] = br->levels[i - level_ac_battery];
 868                 count += level_ac_battery;
 869         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 870                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 871
 872         /* Check if the _BCL package is in a reversed order */
 873         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 874                 br->flags._BCL_reversed = 1;
 875                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 876                      count - ACPI_VIDEO_FIRST_LEVEL,
 877                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 878                      acpi_video_cmp_level, NULL);
 879         } else if (max_level != br->levels[count - 1])
 880                 ACPI_ERROR((AE_INFO,
 881                             "Found unordered _BCL package"));
 882
 883         br->count = count;
 884         *dev_br = br;
 885         if (pmax_level)
 886                 *pmax_level = max_level;
 887
 888 out:
 889         kfree(obj);
 890         return result;
 891 out_free:
 892         kfree(br);
 893         goto out;
 894 }
 895 EXPORT_SYMBOL(acpi_video_get_levels);
 896
 897 /*
 898  *  Arg:
 899  *      device  : video output device (LCD, CRT, ..)
 900  *
 901  *  Return Value:
 902  *      Maximum brightness level
 903  *
 904  *  Allocate and initialize device->brightness.
 905  */
 906
 907 static int
 908 acpi_video_init_brightness(struct acpi_video_device *device)
 909 {
 910         int i, max_level = 0;
 911         unsigned long long level, level_old;
 912         struct acpi_video_device_brightness *br = NULL;
 913         int result = -EINVAL;
 914
 915         result = acpi_video_get_levels(device->dev, &br, &max_level);
 916         if (result)
 917                 return result;
 918         device->brightness = br;
 919
 920         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 921         br->curr = level = max_level;
 922
 923         if (!device->cap._BQC)
 924                 goto set_level;
 925
 926         result = acpi_video_device_lcd_get_level_current(device,
 927                                                          &level_old, true);
 928         if (result)
 929                 goto out_free_levels;
 930
 931         result = acpi_video_bqc_quirk(device, max_level, level_old);
 932         if (result)
 933                 goto out_free_levels;
 934         /*
 935          * cap._BQC may get cleared due to _BQC is found to be broken
 936          * in acpi_video_bqc_quirk, so check again here.
 937          */
 938         if (!device->cap._BQC)
 939                 goto set_level;
 940
 941         level = acpi_video_bqc_value_to_level(device, level_old);
 942         /*
 943          * On some buggy laptops, _BQC returns an uninitialized
 944          * value when invoked for the first time, i.e.
 945          * level_old is invalid (no matter whether it's a level
 946          * or an index). Set the backlight to max_level in this case.
 947          */
 948         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 949                 if (level == br->levels[i])
 950                         break;
 951         if (i == br->count || !level)
 952                 level = max_level;
 953
 954 set_level:
 955         result = acpi_video_device_lcd_set_level(device, level);
 956         if (result)
 957                 goto out_free_levels;
 958
 959         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 960                           "found %d brightness levels\n",
 961                           br->count - ACPI_VIDEO_FIRST_LEVEL));
 962         return 0;
 963
 964 out_free_levels:
 965         kfree(br->levels);
 966         kfree(br);
 967         device->brightness = NULL;
 968         return result;
 969 }
 970
 971 /*
 972  *  Arg:
 973  *      device  : video output device (LCD, CRT, ..)
 974  *
 975  *  Return Value:
 976  *      None
 977  *
 978  *  Find out all required AML methods defined under the output
 979  *  device.
 980  */
 981
 982 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 983 {
 984         if (acpi_has_method(device->dev->handle, "_ADR"))
 985                 device->cap._ADR = 1;
 986         if (acpi_has_method(device->dev->handle, "_BCL"))
 987                 device->cap._BCL = 1;
 988         if (acpi_has_method(device->dev->handle, "_BCM"))
 989                 device->cap._BCM = 1;
 990         if (acpi_has_method(device->dev->handle, "_BQC")) {
 991                 device->cap._BQC = 1;
 992         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 993                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 994                 device->cap._BCQ = 1;
 995         }
 996
 997         if (acpi_has_method(device->dev->handle, "_DDC"))
 998                 device->cap._DDC = 1;
 999 }
1000
1001 /*
1002  *  Arg:
1003  *      device  : video output device (VGA)
1004  *
1005  *  Return Value:
1006  *      None
1007  *
1008  *  Find out all required AML methods defined under the video bus device.
1009  */
1010
1011 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1012 {
1013         if (acpi_has_method(video->device->handle, "_DOS"))
1014                 video->cap._DOS = 1;
1015         if (acpi_has_method(video->device->handle, "_DOD"))
1016                 video->cap._DOD = 1;
1017         if (acpi_has_method(video->device->handle, "_ROM"))
1018                 video->cap._ROM = 1;
1019         if (acpi_has_method(video->device->handle, "_GPD"))
1020                 video->cap._GPD = 1;
1021         if (acpi_has_method(video->device->handle, "_SPD"))
1022                 video->cap._SPD = 1;
1023         if (acpi_has_method(video->device->handle, "_VPO"))
1024                 video->cap._VPO = 1;
1025 }
1026
1027 /*
1028  * Check whether the video bus device has required AML method to
1029  * support the desired features
1030  */
1031
1032 static int acpi_video_bus_check(struct acpi_video_bus *video)
1033 {
1034         acpi_status status = -ENOENT;
1035         struct pci_dev *dev;
1036
1037         if (!video)
1038                 return -EINVAL;
1039
1040         dev = acpi_get_pci_dev(video->device->handle);
1041         if (!dev)
1042                 return -ENODEV;
1043         pci_dev_put(dev);
1044
1045         /*
1046          * Since there is no HID, CID and so on for VGA driver, we have
1047          * to check well known required nodes.
1048          */
1049
1050         /* Does this device support video switching? */
1051         if (video->cap._DOS || video->cap._DOD) {
1052                 if (!video->cap._DOS) {
1053                         printk(KERN_WARNING FW_BUG
1054                                 "ACPI(%s) defines _DOD but not _DOS\n",
1055                                 acpi_device_bid(video->device));
1056                 }
1057                 video->flags.multihead = 1;
1058                 status = 0;
1059         }
1060
1061         /* Does this device support retrieving a video ROM? */
1062         if (video->cap._ROM) {
1063                 video->flags.rom = 1;
1064                 status = 0;
1065         }
1066
1067         /* Does this device support configuring which video device to POST? */
1068         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1069                 video->flags.post = 1;
1070                 status = 0;
1071         }
1072
1073         return status;
1074 }
1075
1076 /*
1077  * --------------------------------------------------------------------------
1078  *                               Driver Interface
1079  * --------------------------------------------------------------------------
1080  */
1081
1082 /* device interface */
1083 static struct acpi_video_device_attrib *
1084 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1085 {
1086         struct acpi_video_enumerated_device *ids;
1087         int i;
1088
1089         for (i = 0; i < video->attached_count; i++) {
1090                 ids = &video->attached_array[i];
1091                 if ((ids->value.int_val & 0xffff) == device_id)
1092                         return &ids->value.attrib;
1093         }
1094
1095         return NULL;
1096 }
1097
1098 static int
1099 acpi_video_get_device_type(struct acpi_video_bus *video,
1100                            unsigned long device_id)
1101 {
1102         struct acpi_video_enumerated_device *ids;
1103         int i;
1104
1105         for (i = 0; i < video->attached_count; i++) {
1106                 ids = &video->attached_array[i];
1107                 if ((ids->value.int_val & 0xffff) == device_id)
1108                         return ids->value.int_val;
1109         }
1110
1111         return 0;
1112 }
1113
1114 static int
1115 acpi_video_bus_get_one_device(struct acpi_device *device,
1116                               struct acpi_video_bus *video)
1117 {
1118         unsigned long long device_id;
1119         int status, device_type;
1120         struct acpi_video_device *data;
1121         struct acpi_video_device_attrib *attribute;
1122
1123         status =
1124             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1125         /* Some device omits _ADR, we skip them instead of fail */
1126         if (ACPI_FAILURE(status))
1127                 return 0;
1128
1129         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1130         if (!data)
1131                 return -ENOMEM;
1132
1133         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1134         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1135         device->driver_data = data;
1136
1137         data->device_id = device_id;
1138         data->video = video;
1139         data->dev = device;
1140         INIT_DELAYED_WORK(&data->switch_brightness_work,
1141                           acpi_video_switch_brightness);
1142
1143         attribute = acpi_video_get_device_attr(video, device_id);
1144
1145         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1146                 switch (attribute->display_type) {
1147                 case ACPI_VIDEO_DISPLAY_CRT:
1148                         data->flags.crt = 1;
1149                         break;
1150                 case ACPI_VIDEO_DISPLAY_TV:
1151                         data->flags.tvout = 1;
1152                         break;
1153                 case ACPI_VIDEO_DISPLAY_DVI:
1154                         data->flags.dvi = 1;
1155                         break;
1156                 case ACPI_VIDEO_DISPLAY_LCD:
1157                         data->flags.lcd = 1;
1158                         break;
1159                 default:
1160                         data->flags.unknown = 1;
1161                         break;
1162                 }
1163                 if (attribute->bios_can_detect)
1164                         data->flags.bios = 1;
1165         } else {
1166                 /* Check for legacy IDs */
1167                 device_type = acpi_video_get_device_type(video, device_id);
1168                 /* Ignore bits 16 and 18-20 */
1169                 switch (device_type & 0xffe2ffff) {
1170                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1171                         data->flags.crt = 1;
1172                         break;
1173                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1174                         data->flags.lcd = 1;
1175                         break;
1176                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1177                         data->flags.tvout = 1;
1178                         break;
1179                 default:
1180                         data->flags.unknown = 1;
1181                 }
1182         }
1183
1184         acpi_video_device_bind(video, data);
1185         acpi_video_device_find_cap(data);
1186
1187         mutex_lock(&video->device_list_lock);
1188         list_add_tail(&data->entry, &video->video_device_list);
1189         mutex_unlock(&video->device_list_lock);
1190
1191         return status;
1192 }
1193
1194 /*
1195  *  Arg:
1196  *      video   : video bus device
1197  *
1198  *  Return:
1199  *      none
1200  *
1201  *  Enumerate the video device list of the video bus,
1202  *  bind the ids with the corresponding video devices
1203  *  under the video bus.
1204  */
1205
1206 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1207 {
1208         struct acpi_video_device *dev;
1209
1210         mutex_lock(&video->device_list_lock);
1211
1212         list_for_each_entry(dev, &video->video_device_list, entry)
1213                 acpi_video_device_bind(video, dev);
1214
1215         mutex_unlock(&video->device_list_lock);
1216 }
1217
1218 /*
1219  *  Arg:
1220  *      video   : video bus device
1221  *      device  : video output device under the video
1222  *              bus
1223  *
1224  *  Return:
1225  *      none
1226  *
1227  *  Bind the ids with the corresponding video devices
1228  *  under the video bus.
1229  */
1230
1231 static void
1232 acpi_video_device_bind(struct acpi_video_bus *video,
1233                        struct acpi_video_device *device)
1234 {
1235         struct acpi_video_enumerated_device *ids;
1236         int i;
1237
1238         for (i = 0; i < video->attached_count; i++) {
1239                 ids = &video->attached_array[i];
1240                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1241                         ids->bind_info = device;
1242                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1243                 }
1244         }
1245 }
1246
1247 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1248 {
1249         struct acpi_video_bus *video = device->video;
1250         int i;
1251
1252         /*
1253          * If we have a broken _DOD or we have more than 8 output devices
1254          * under the graphics controller node that we can't proper deal with
1255          * in the operation region code currently, no need to test.
1256          */
1257         if (!video->attached_count || video->child_count > 8)
1258                 return true;
1259
1260         for (i = 0; i < video->attached_count; i++) {
1261                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1262                     (device->device_id & 0xfff))
1263                         return true;
1264         }
1265
1266         return false;
1267 }
1268
1269 /*
1270  *  Arg:
1271  *      video   : video bus device
1272  *
1273  *  Return:
1274  *      < 0     : error
1275  *
1276  *  Call _DOD to enumerate all devices attached to display adapter
1277  *
1278  */
1279
1280 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1281 {
1282         int status;
1283         int count;
1284         int i;
1285         struct acpi_video_enumerated_device *active_list;
1286         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1287         union acpi_object *dod = NULL;
1288         union acpi_object *obj;
1289
1290         if (!video->cap._DOD)
1291                 return AE_NOT_EXIST;
1292
1293         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1294         if (!ACPI_SUCCESS(status)) {
1295                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1296                 return status;
1297         }
1298
1299         dod = buffer.pointer;
1300         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1301                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1302                 status = -EFAULT;
1303                 goto out;
1304         }
1305
1306         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1307                           dod->package.count));
1308
1309         active_list = kcalloc(1 + dod->package.count,
1310                               sizeof(struct acpi_video_enumerated_device),
1311                               GFP_KERNEL);
1312         if (!active_list) {
1313                 status = -ENOMEM;
1314                 goto out;
1315         }
1316
1317         count = 0;
1318         for (i = 0; i < dod->package.count; i++) {
1319                 obj = &dod->package.elements[i];
1320
1321                 if (obj->type != ACPI_TYPE_INTEGER) {
1322                         printk(KERN_ERR PREFIX
1323                                 "Invalid _DOD data in element %d\n", i);
1324                         continue;
1325                 }
1326
1327                 active_list[count].value.int_val = obj->integer.value;
1328                 active_list[count].bind_info = NULL;
1329                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1330                                   (int)obj->integer.value));
1331                 count++;
1332         }
1333
1334         kfree(video->attached_array);
1335
1336         video->attached_array = active_list;
1337         video->attached_count = count;
1338
1339 out:
1340         kfree(buffer.pointer);
1341         return status;
1342 }
1343
1344 static int
1345 acpi_video_get_next_level(struct acpi_video_device *device,
1346                           u32 level_current, u32 event)
1347 {
1348         int min, max, min_above, max_below, i, l, delta = 255;
1349         max = max_below = 0;
1350         min = min_above = 255;
1351         /* Find closest level to level_current */
1352         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1353                 l = device->brightness->levels[i];
1354                 if (abs(l - level_current) < abs(delta)) {
1355                         delta = l - level_current;
1356                         if (!delta)
1357                                 break;
1358                 }
1359         }
1360         /* Ajust level_current to closest available level */
1361         level_current += delta;
1362         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1363                 l = device->brightness->levels[i];
1364                 if (l < min)
1365                         min = l;
1366                 if (l > max)
1367                         max = l;
1368                 if (l < min_above && l > level_current)
1369                         min_above = l;
1370                 if (l > max_below && l < level_current)
1371                         max_below = l;
1372         }
1373
1374         switch (event) {
1375         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1376                 return (level_current < max) ? min_above : min;
1377         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1378                 return (level_current < max) ? min_above : max;
1379         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1380                 return (level_current > min) ? max_below : min;
1381         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1382         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1383                 return 0;
1384         default:
1385                 return level_current;
1386         }
1387 }
1388
1389 static void
1390 acpi_video_switch_brightness(struct work_struct *work)
1391 {
1392         struct acpi_video_device *device = container_of(to_delayed_work(work),
1393                              struct acpi_video_device, switch_brightness_work);
1394         unsigned long long level_current, level_next;
1395         int event = device->switch_brightness_event;
1396         int result = -EINVAL;
1397
1398         /* no warning message if acpi_backlight=vendor or a quirk is used */
1399         if (!device->backlight)
1400                 return;
1401
1402         if (!device->brightness)
1403                 goto out;
1404
1405         result = acpi_video_device_lcd_get_level_current(device,
1406                                                          &level_current,
1407                                                          false);
1408         if (result)
1409                 goto out;
1410
1411         level_next = acpi_video_get_next_level(device, level_current, event);
1412
1413         result = acpi_video_device_lcd_set_level(device, level_next);
1414
1415         if (!result)
1416                 backlight_force_update(device->backlight,
1417                                        BACKLIGHT_UPDATE_HOTKEY);
1418
1419 out:
1420         if (result)
1421                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1422 }
1423
1424 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1425                         void **edid)
1426 {
1427         struct acpi_video_bus *video;
1428         struct acpi_video_device *video_device;
1429         union acpi_object *buffer = NULL;
1430         acpi_status status;
1431         int i, length;
1432
1433         if (!device || !acpi_driver_data(device))
1434                 return -EINVAL;
1435
1436         video = acpi_driver_data(device);
1437
1438         for (i = 0; i < video->attached_count; i++) {
1439                 video_device = video->attached_array[i].bind_info;
1440                 length = 256;
1441
1442                 if (!video_device)
1443                         continue;
1444
1445                 if (!video_device->cap._DDC)
1446                         continue;
1447
1448                 if (type) {
1449                         switch (type) {
1450                         case ACPI_VIDEO_DISPLAY_CRT:
1451                                 if (!video_device->flags.crt)
1452                                         continue;
1453                                 break;
1454                         case ACPI_VIDEO_DISPLAY_TV:
1455                                 if (!video_device->flags.tvout)
1456                                         continue;
1457                                 break;
1458                         case ACPI_VIDEO_DISPLAY_DVI:
1459                                 if (!video_device->flags.dvi)
1460                                         continue;
1461                                 break;
1462                         case ACPI_VIDEO_DISPLAY_LCD:
1463                                 if (!video_device->flags.lcd)
1464                                         continue;
1465                                 break;
1466                         }
1467                 } else if (video_device->device_id != device_id) {
1468                         continue;
1469                 }
1470
1471                 status = acpi_video_device_EDID(video_device, &buffer, length);
1472
1473                 if (ACPI_FAILURE(status) || !buffer ||
1474                     buffer->type != ACPI_TYPE_BUFFER) {
1475                         length = 128;
1476                         status = acpi_video_device_EDID(video_device, &buffer,
1477                                                         length);
1478                         if (ACPI_FAILURE(status) || !buffer ||
1479                             buffer->type != ACPI_TYPE_BUFFER) {
1480                                 continue;
1481                         }
1482                 }
1483
1484                 *edid = buffer->buffer.pointer;
1485                 return length;
1486         }
1487
1488         return -ENODEV;
1489 }
1490 EXPORT_SYMBOL(acpi_video_get_edid);
1491
1492 static int
1493 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1494                            struct acpi_device *device)
1495 {
1496         int status = 0;
1497         struct acpi_device *dev;
1498
1499         /*
1500          * There are systems where video module known to work fine regardless
1501          * of broken _DOD and ignoring returned value here doesn't cause
1502          * any issues later.
1503          */
1504         acpi_video_device_enumerate(video);
1505
1506         list_for_each_entry(dev, &device->children, node) {
1507
1508                 status = acpi_video_bus_get_one_device(dev, video);
1509                 if (status) {
1510                         dev_err(&dev->dev, "Can't attach device\n");
1511                         break;
1512                 }
1513                 video->child_count++;
1514         }
1515         return status;
1516 }
1517
1518 /* acpi_video interface */
1519
1520 /*
1521  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1522  * preform any automatic brightness change on receiving a notification.
1523  */
1524 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1525 {
1526         return acpi_video_bus_DOS(video, 0,
1527                                   acpi_osi_is_win8() ? 1 : 0);
1528 }
1529
1530 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1531 {
1532         return acpi_video_bus_DOS(video, 0,
1533                                   acpi_osi_is_win8() ? 0 : 1);
1534 }
1535
1536 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1537 {
1538         struct acpi_video_bus *video = acpi_driver_data(device);
1539         struct input_dev *input;
1540         int keycode = 0;
1541
1542         if (!video || !video->input)
1543                 return;
1544
1545         input = video->input;
1546
1547         switch (event) {
1548         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1549                                          * most likely via hotkey. */
1550                 keycode = KEY_SWITCHVIDEOMODE;
1551                 break;
1552
1553         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1554                                          * connector. */
1555                 acpi_video_device_enumerate(video);
1556                 acpi_video_device_rebind(video);
1557                 keycode = KEY_SWITCHVIDEOMODE;
1558                 break;
1559
1560         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1561                 keycode = KEY_SWITCHVIDEOMODE;
1562                 break;
1563         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1564                 keycode = KEY_VIDEO_NEXT;
1565                 break;
1566         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1567                 keycode = KEY_VIDEO_PREV;
1568                 break;
1569
1570         default:
1571                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1572                                   "Unsupported event [0x%x]\n", event));
1573                 break;
1574         }
1575
1576         if (acpi_notifier_call_chain(device, event, 0))
1577                 /* Something vetoed the keypress. */
1578                 keycode = 0;
1579
1580         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1581                 input_report_key(input, keycode, 1);
1582                 input_sync(input);
1583                 input_report_key(input, keycode, 0);
1584                 input_sync(input);
1585         }
1586
1587         return;
1588 }
1589
1590 static void brightness_switch_event(struct acpi_video_device *video_device,
1591                                     u32 event)
1592 {
1593         if (!brightness_switch_enabled)
1594                 return;
1595
1596         video_device->switch_brightness_event = event;
1597         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1598 }
1599
1600 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1601 {
1602         struct acpi_video_device *video_device = data;
1603         struct acpi_device *device = NULL;
1604         struct acpi_video_bus *bus;
1605         struct input_dev *input;
1606         int keycode = 0;
1607
1608         if (!video_device)
1609                 return;
1610
1611         device = video_device->dev;
1612         bus = video_device->video;
1613         input = bus->input;
1614
1615         switch (event) {
1616         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1617                 brightness_switch_event(video_device, event);
1618                 keycode = KEY_BRIGHTNESS_CYCLE;
1619                 break;
1620         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1621                 brightness_switch_event(video_device, event);
1622                 keycode = KEY_BRIGHTNESSUP;
1623                 break;
1624         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1625                 brightness_switch_event(video_device, event);
1626                 keycode = KEY_BRIGHTNESSDOWN;
1627                 break;
1628         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1629                 brightness_switch_event(video_device, event);
1630                 keycode = KEY_BRIGHTNESS_ZERO;
1631                 break;
1632         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1633                 brightness_switch_event(video_device, event);
1634                 keycode = KEY_DISPLAY_OFF;
1635                 break;
1636         default:
1637                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1638                                   "Unsupported event [0x%x]\n", event));
1639                 break;
1640         }
1641
1642         acpi_notifier_call_chain(device, event, 0);
1643
1644         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1645                 input_report_key(input, keycode, 1);
1646                 input_sync(input);
1647                 input_report_key(input, keycode, 0);
1648                 input_sync(input);
1649         }
1650
1651         return;
1652 }
1653
1654 static int acpi_video_resume(struct notifier_block *nb,
1655                                 unsigned long val, void *ign)
1656 {
1657         struct acpi_video_bus *video;
1658         struct acpi_video_device *video_device;
1659         int i;
1660
1661         switch (val) {
1662         case PM_HIBERNATION_PREPARE:
1663         case PM_SUSPEND_PREPARE:
1664         case PM_RESTORE_PREPARE:
1665                 return NOTIFY_DONE;
1666         }
1667
1668         video = container_of(nb, struct acpi_video_bus, pm_nb);
1669
1670         dev_info(&video->device->dev, "Restoring backlight state\n");
1671
1672         for (i = 0; i < video->attached_count; i++) {
1673                 video_device = video->attached_array[i].bind_info;
1674                 if (video_device && video_device->brightness)
1675                         acpi_video_device_lcd_set_level(video_device,
1676                                         video_device->brightness->curr);
1677         }
1678
1679         return NOTIFY_OK;
1680 }
1681
1682 static acpi_status
1683 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1684                         void **return_value)
1685 {
1686         struct acpi_device *device = context;
1687         struct acpi_device *sibling;
1688         int result;
1689
1690         if (handle == device->handle)
1691                 return AE_CTRL_TERMINATE;
1692
1693         result = acpi_bus_get_device(handle, &sibling);
1694         if (result)
1695                 return AE_OK;
1696
1697         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1698                         return AE_ALREADY_EXISTS;
1699
1700         return AE_OK;
1701 }
1702
1703 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1704 {
1705         struct backlight_properties props;
1706         struct pci_dev *pdev;
1707         acpi_handle acpi_parent;
1708         struct device *parent = NULL;
1709         int result;
1710         static int count;
1711         char *name;
1712
1713         result = acpi_video_init_brightness(device);
1714         if (result)
1715                 return;
1716
1717         if (disable_backlight_sysfs_if > 0)
1718                 return;
1719
1720         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1721         if (!name)
1722                 return;
1723         count++;
1724
1725         acpi_get_parent(device->dev->handle, &acpi_parent);
1726
1727         pdev = acpi_get_pci_dev(acpi_parent);
1728         if (pdev) {
1729                 parent = &pdev->dev;
1730                 pci_dev_put(pdev);
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",
1756                                 device->dev, &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                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1775         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1776                         &device->dev->dev.kobj, "device");
1777         if (result)
1778                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1779 }
1780
1781 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1782 {
1783         struct acpi_video_device *dev;
1784         union acpi_object *levels;
1785
1786         mutex_lock(&video->device_list_lock);
1787         list_for_each_entry(dev, &video->video_device_list, entry) {
1788                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1789                         kfree(levels);
1790         }
1791         mutex_unlock(&video->device_list_lock);
1792 }
1793
1794 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1795 {
1796         /*
1797          * Do not create backlight device for video output
1798          * device that is not in the enumerated list.
1799          */
1800         if (!acpi_video_device_in_dod(dev)) {
1801                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1802                 return false;
1803         }
1804
1805         if (only_lcd)
1806                 return dev->flags.lcd;
1807         return true;
1808 }
1809
1810 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1811 {
1812         struct acpi_video_device *dev;
1813
1814         if (video->backlight_registered)
1815                 return 0;
1816
1817         acpi_video_run_bcl_for_osi(video);
1818
1819         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1820                 return 0;
1821
1822         mutex_lock(&video->device_list_lock);
1823         list_for_each_entry(dev, &video->video_device_list, entry) {
1824                 if (acpi_video_should_register_backlight(dev))
1825                         acpi_video_dev_register_backlight(dev);
1826         }
1827         mutex_unlock(&video->device_list_lock);
1828
1829         video->backlight_registered = true;
1830
1831         video->pm_nb.notifier_call = acpi_video_resume;
1832         video->pm_nb.priority = 0;
1833         return register_pm_notifier(&video->pm_nb);
1834 }
1835
1836 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1837 {
1838         if (device->backlight) {
1839                 backlight_device_unregister(device->backlight);
1840                 device->backlight = NULL;
1841         }
1842         if (device->brightness) {
1843                 kfree(device->brightness->levels);
1844                 kfree(device->brightness);
1845                 device->brightness = NULL;
1846         }
1847         if (device->cooling_dev) {
1848                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1849                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1850                 thermal_cooling_device_unregister(device->cooling_dev);
1851                 device->cooling_dev = NULL;
1852         }
1853 }
1854
1855 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1856 {
1857         struct acpi_video_device *dev;
1858         int error;
1859
1860         if (!video->backlight_registered)
1861                 return 0;
1862
1863         error = unregister_pm_notifier(&video->pm_nb);
1864
1865         mutex_lock(&video->device_list_lock);
1866         list_for_each_entry(dev, &video->video_device_list, entry)
1867                 acpi_video_dev_unregister_backlight(dev);
1868         mutex_unlock(&video->device_list_lock);
1869
1870         video->backlight_registered = false;
1871
1872         return error;
1873 }
1874
1875 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1876 {
1877         acpi_status status;
1878         struct acpi_device *adev = device->dev;
1879
1880         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1881                                              acpi_video_device_notify, device);
1882         if (ACPI_FAILURE(status))
1883                 dev_err(&adev->dev, "Error installing notify handler\n");
1884         else
1885                 device->flags.notify = 1;
1886 }
1887
1888 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1889 {
1890         struct input_dev *input;
1891         struct acpi_video_device *dev;
1892         int error;
1893
1894         video->input = input = input_allocate_device();
1895         if (!input) {
1896                 error = -ENOMEM;
1897                 goto out;
1898         }
1899
1900         error = acpi_video_bus_start_devices(video);
1901         if (error)
1902                 goto err_free_input;
1903
1904         snprintf(video->phys, sizeof(video->phys),
1905                         "%s/video/input0", acpi_device_hid(video->device));
1906
1907         input->name = acpi_device_name(video->device);
1908         input->phys = video->phys;
1909         input->id.bustype = BUS_HOST;
1910         input->id.product = 0x06;
1911         input->dev.parent = &video->device->dev;
1912         input->evbit[0] = BIT(EV_KEY);
1913         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1914         set_bit(KEY_VIDEO_NEXT, input->keybit);
1915         set_bit(KEY_VIDEO_PREV, input->keybit);
1916         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1917         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1918         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1919         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1920         set_bit(KEY_DISPLAY_OFF, input->keybit);
1921
1922         error = input_register_device(input);
1923         if (error)
1924                 goto err_stop_dev;
1925
1926         mutex_lock(&video->device_list_lock);
1927         list_for_each_entry(dev, &video->video_device_list, entry)
1928                 acpi_video_dev_add_notify_handler(dev);
1929         mutex_unlock(&video->device_list_lock);
1930
1931         return 0;
1932
1933 err_stop_dev:
1934         acpi_video_bus_stop_devices(video);
1935 err_free_input:
1936         input_free_device(input);
1937         video->input = NULL;
1938 out:
1939         return error;
1940 }
1941
1942 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1943 {
1944         if (dev->flags.notify) {
1945                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1946                                            acpi_video_device_notify);
1947                 dev->flags.notify = 0;
1948         }
1949 }
1950
1951 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1952 {
1953         struct acpi_video_device *dev;
1954
1955         mutex_lock(&video->device_list_lock);
1956         list_for_each_entry(dev, &video->video_device_list, entry)
1957                 acpi_video_dev_remove_notify_handler(dev);
1958         mutex_unlock(&video->device_list_lock);
1959
1960         acpi_video_bus_stop_devices(video);
1961         input_unregister_device(video->input);
1962         video->input = NULL;
1963 }
1964
1965 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1966 {
1967         struct acpi_video_device *dev, *next;
1968
1969         mutex_lock(&video->device_list_lock);
1970         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1971                 list_del(&dev->entry);
1972                 kfree(dev);
1973         }
1974         mutex_unlock(&video->device_list_lock);
1975
1976         return 0;
1977 }
1978
1979 static int instance;
1980
1981 static int acpi_video_bus_add(struct acpi_device *device)
1982 {
1983         struct acpi_video_bus *video;
1984         int error;
1985         acpi_status status;
1986
1987         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1988                                 device->parent->handle, 1,
1989                                 acpi_video_bus_match, NULL,
1990                                 device, NULL);
1991         if (status == AE_ALREADY_EXISTS) {
1992                 printk(KERN_WARNING 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         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2036                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2037                video->flags.multihead ? "yes" : "no",
2038                video->flags.rom ? "yes" : "no",
2039                video->flags.post ? "yes" : "no");
2040         mutex_lock(&video_list_lock);
2041         list_add_tail(&video->entry, &video_bus_head);
2042         mutex_unlock(&video_list_lock);
2043
2044         acpi_video_bus_register_backlight(video);
2045         acpi_video_bus_add_notify_handler(video);
2046
2047         return 0;
2048
2049 err_put_video:
2050         acpi_video_bus_put_devices(video);
2051         kfree(video->attached_array);
2052 err_free_video:
2053         kfree(video);
2054         device->driver_data = NULL;
2055
2056         return error;
2057 }
2058
2059 static int acpi_video_bus_remove(struct acpi_device *device)
2060 {
2061         struct acpi_video_bus *video = NULL;
2062
2063
2064         if (!device || !acpi_driver_data(device))
2065                 return -EINVAL;
2066
2067         video = acpi_driver_data(device);
2068
2069         acpi_video_bus_remove_notify_handler(video);
2070         acpi_video_bus_unregister_backlight(video);
2071         acpi_video_bus_put_devices(video);
2072
2073         mutex_lock(&video_list_lock);
2074         list_del(&video->entry);
2075         mutex_unlock(&video_list_lock);
2076
2077         kfree(video->attached_array);
2078         kfree(video);
2079
2080         return 0;
2081 }
2082
2083 static int __init is_i740(struct pci_dev *dev)
2084 {
2085         if (dev->device == 0x00D1)
2086                 return 1;
2087         if (dev->device == 0x7000)
2088                 return 1;
2089         return 0;
2090 }
2091
2092 static int __init intel_opregion_present(void)
2093 {
2094         int opregion = 0;
2095         struct pci_dev *dev = NULL;
2096         u32 address;
2097
2098         for_each_pci_dev(dev) {
2099                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2100                         continue;
2101                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2102                         continue;
2103                 /* We don't want to poke around undefined i740 registers */
2104                 if (is_i740(dev))
2105                         continue;
2106                 pci_read_config_dword(dev, 0xfc, &address);
2107                 if (!address)
2108                         continue;
2109                 opregion = 1;
2110         }
2111         return opregion;
2112 }
2113
2114 /* Check if the chassis-type indicates there is no builtin LCD panel */
2115 static bool dmi_is_desktop(void)
2116 {
2117         const char *chassis_type;
2118         unsigned long type;
2119
2120         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2121         if (!chassis_type)
2122                 return false;
2123
2124         if (kstrtoul(chassis_type, 10, &type) != 0)
2125                 return false;
2126
2127         switch (type) {
2128         case 0x03: /* Desktop */
2129         case 0x04: /* Low Profile Desktop */
2130         case 0x05: /* Pizza Box */
2131         case 0x06: /* Mini Tower */
2132         case 0x07: /* Tower */
2133         case 0x10: /* Lunch Box */
2134         case 0x11: /* Main Server Chassis */
2135                 return true;
2136         }
2137
2138         return false;
2139 }
2140
2141 int acpi_video_register(void)
2142 {
2143         int ret = 0;
2144
2145         mutex_lock(&register_count_mutex);
2146         if (register_count) {
2147                 /*
2148                  * if the function of acpi_video_register is already called,
2149                  * don't register the acpi_vide_bus again and return no error.
2150                  */
2151                 goto leave;
2152         }
2153
2154         /*
2155          * We're seeing a lot of bogus backlight interfaces on newer machines
2156          * without a LCD such as desktops, servers and HDMI sticks. Checking
2157          * the lcd flag fixes this, so enable this on any machines which are
2158          * win8 ready (where we also prefer the native backlight driver, so
2159          * normally the acpi_video code should not register there anyways).
2160          */
2161         if (only_lcd == -1) {
2162                 if (dmi_is_desktop() && acpi_osi_is_win8())
2163                         only_lcd = true;
2164                 else
2165                         only_lcd = false;
2166         }
2167
2168         dmi_check_system(video_dmi_table);
2169
2170         ret = acpi_bus_register_driver(&acpi_video_bus);
2171         if (ret)
2172                 goto leave;
2173
2174         /*
2175          * When the acpi_video_bus is loaded successfully, increase
2176          * the counter reference.
2177          */
2178         register_count = 1;
2179
2180 leave:
2181         mutex_unlock(&register_count_mutex);
2182         return ret;
2183 }
2184 EXPORT_SYMBOL(acpi_video_register);
2185
2186 void acpi_video_unregister(void)
2187 {
2188         mutex_lock(&register_count_mutex);
2189         if (register_count) {
2190                 acpi_bus_unregister_driver(&acpi_video_bus);
2191                 register_count = 0;
2192         }
2193         mutex_unlock(&register_count_mutex);
2194 }
2195 EXPORT_SYMBOL(acpi_video_unregister);
2196
2197 void acpi_video_unregister_backlight(void)
2198 {
2199         struct acpi_video_bus *video;
2200
2201         mutex_lock(&register_count_mutex);
2202         if (register_count) {
2203                 mutex_lock(&video_list_lock);
2204                 list_for_each_entry(video, &video_bus_head, entry)
2205                         acpi_video_bus_unregister_backlight(video);
2206                 mutex_unlock(&video_list_lock);
2207         }
2208         mutex_unlock(&register_count_mutex);
2209 }
2210
2211 bool acpi_video_handles_brightness_key_presses(void)
2212 {
2213         bool have_video_busses;
2214
2215         mutex_lock(&video_list_lock);
2216         have_video_busses = !list_empty(&video_bus_head);
2217         mutex_unlock(&video_list_lock);
2218
2219         return have_video_busses &&
2220                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2221 }
2222 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2223
2224 /*
2225  * This is kind of nasty. Hardware using Intel chipsets may require
2226  * the video opregion code to be run first in order to initialise
2227  * state before any ACPI video calls are made. To handle this we defer
2228  * registration of the video class until the opregion code has run.
2229  */
2230
2231 static int __init acpi_video_init(void)
2232 {
2233         /*
2234          * Let the module load even if ACPI is disabled (e.g. due to
2235          * a broken BIOS) so that i915.ko can still be loaded on such
2236          * old systems without an AcpiOpRegion.
2237          *
2238          * acpi_video_register() will report -ENODEV later as well due
2239          * to acpi_disabled when i915.ko tries to register itself afterwards.
2240          */
2241         if (acpi_disabled)
2242                 return 0;
2243
2244         if (intel_opregion_present())
2245                 return 0;
2246
2247         return acpi_video_register();
2248 }
2249
2250 static void __exit acpi_video_exit(void)
2251 {
2252         acpi_video_detect_exit();
2253         acpi_video_unregister();
2254
2255         return;
2256 }
2257
2258 module_init(acpi_video_init);
2259 module_exit(acpi_video_exit);