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