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;
  71 module_param(only_lcd, int, 0444);
  72
  73 static bool may_report_brightness_keys;
  74 static int register_count;
  75 static DEFINE_MUTEX(register_count_mutex);
  76 static DEFINE_MUTEX(video_list_lock);
  77 static LIST_HEAD(video_bus_head);
  78 static int acpi_video_bus_add(struct acpi_device *device);
  79 static void acpi_video_bus_remove(struct acpi_device *device);
  80 static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data);
  81
  82 /*
  83  * Indices in the _BCL method response: the first two items are special,
  84  * the rest are all supported levels.
  85  *
  86  * See page 575 of the ACPI spec 3.0
  87  */
  88 enum acpi_video_level_idx {
  89         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
  90         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
  91         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
  92 };
  93
  94 static const struct acpi_device_id video_device_ids[] = {
  95         {ACPI_VIDEO_HID, 0},
  96         {"", 0},
  97 };
  98 MODULE_DEVICE_TABLE(acpi, video_device_ids);
  99
 100 static struct acpi_driver acpi_video_bus = {
 101         .name = "video",
 102         .class = ACPI_VIDEO_CLASS,
 103         .ids = video_device_ids,
 104         .ops = {
 105                 .add = acpi_video_bus_add,
 106                 .remove = acpi_video_bus_remove,
 107                 },
 108 };
 109
 110 struct acpi_video_bus_flags {
 111         u8 multihead:1;         /* can switch video heads */
 112         u8 rom:1;               /* can retrieve a video rom */
 113         u8 post:1;              /* can configure the head to */
 114         u8 reserved:5;
 115 };
 116
 117 struct acpi_video_bus_cap {
 118         u8 _DOS:1;              /* Enable/Disable output switching */
 119         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 120         u8 _ROM:1;              /* Get ROM Data */
 121         u8 _GPD:1;              /* Get POST Device */
 122         u8 _SPD:1;              /* Set POST Device */
 123         u8 _VPO:1;              /* Video POST Options */
 124         u8 reserved:2;
 125 };
 126
 127 struct acpi_video_device_attrib {
 128         u32 display_index:4;    /* A zero-based instance of the Display */
 129         u32 display_port_attachment:4;  /* This field differentiates the display type */
 130         u32 display_type:4;     /* Describe the specific type in use */
 131         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 132         u32 bios_can_detect:1;  /* BIOS can detect the device */
 133         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 134                                    the VGA device. */
 135         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 136         u32 reserved:10;        /* Must be 0 */
 137
 138         /*
 139          * The device ID might not actually follow the scheme described by this
 140          * struct acpi_video_device_attrib. If it does, then this bit
 141          * device_id_scheme is set; otherwise, other fields should be ignored.
 142          *
 143          * (but also see the global flag device_id_scheme)
 144          */
 145         u32 device_id_scheme:1;
 146 };
 147
 148 struct acpi_video_enumerated_device {
 149         union {
 150                 u32 int_val;
 151                 struct acpi_video_device_attrib attrib;
 152         } value;
 153         struct acpi_video_device *bind_info;
 154 };
 155
 156 struct acpi_video_bus {
 157         struct acpi_device *device;
 158         bool backlight_registered;
 159         u8 dos_setting;
 160         struct acpi_video_enumerated_device *attached_array;
 161         u8 attached_count;
 162         u8 child_count;
 163         struct acpi_video_bus_cap cap;
 164         struct acpi_video_bus_flags flags;
 165         struct list_head video_device_list;
 166         struct mutex device_list_lock;  /* protects video_device_list */
 167         struct list_head entry;
 168         struct input_dev *input;
 169         char phys[32];  /* for input device */
 170         struct notifier_block pm_nb;
 171 };
 172
 173 struct acpi_video_device_flags {
 174         u8 crt:1;
 175         u8 lcd:1;
 176         u8 tvout:1;
 177         u8 dvi:1;
 178         u8 bios:1;
 179         u8 unknown:1;
 180         u8 notify:1;
 181         u8 reserved:1;
 182 };
 183
 184 struct acpi_video_device_cap {
 185         u8 _ADR:1;              /* Return the unique ID */
 186         u8 _BCL:1;              /* Query list of brightness control levels supported */
 187         u8 _BCM:1;              /* Set the brightness level */
 188         u8 _BQC:1;              /* Get current brightness level */
 189         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 190         u8 _DDC:1;              /* Return the EDID for this device */
 191 };
 192
 193 struct acpi_video_device {
 194         unsigned long device_id;
 195         struct acpi_video_device_flags flags;
 196         struct acpi_video_device_cap cap;
 197         struct list_head entry;
 198         struct delayed_work switch_brightness_work;
 199         int switch_brightness_event;
 200         struct acpi_video_bus *video;
 201         struct acpi_device *dev;
 202         struct acpi_video_device_brightness *brightness;
 203         struct backlight_device *backlight;
 204         struct thermal_cooling_device *cooling_dev;
 205 };
 206
 207 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 208 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 209 static void acpi_video_device_bind(struct acpi_video_bus *video,
 210                                    struct acpi_video_device *device);
 211 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 212 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 213                         int level);
 214 static int acpi_video_device_lcd_get_level_current(
 215                         struct acpi_video_device *device,
 216                         unsigned long long *level, bool raw);
 217 static int acpi_video_get_next_level(struct acpi_video_device *device,
 218                                      u32 level_current, u32 event);
 219 static void acpi_video_switch_brightness(struct work_struct *work);
 220
 221 /* backlight device sysfs support */
 222 static int acpi_video_get_brightness(struct backlight_device *bd)
 223 {
 224         unsigned long long cur_level;
 225         int i;
 226         struct acpi_video_device *vd = bl_get_data(bd);
 227
 228         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 229                 return -EINVAL;
 230         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 231                 if (vd->brightness->levels[i] == cur_level)
 232                         return i - ACPI_VIDEO_FIRST_LEVEL;
 233         }
 234         return 0;
 235 }
 236
 237 static int acpi_video_set_brightness(struct backlight_device *bd)
 238 {
 239         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 240         struct acpi_video_device *vd = bl_get_data(bd);
 241
 242         cancel_delayed_work(&vd->switch_brightness_work);
 243         return acpi_video_device_lcd_set_level(vd,
 244                                 vd->brightness->levels[request_level]);
 245 }
 246
 247 static const struct backlight_ops acpi_backlight_ops = {
 248         .get_brightness = acpi_video_get_brightness,
 249         .update_status  = acpi_video_set_brightness,
 250 };
 251
 252 /* thermal cooling device callbacks */
 253 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 254                                unsigned long *state)
 255 {
 256         struct acpi_video_device *video = cooling_dev->devdata;
 257
 258         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 259         return 0;
 260 }
 261
 262 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 263                                unsigned long *state)
 264 {
 265         struct acpi_video_device *video = cooling_dev->devdata;
 266         unsigned long long level;
 267         int offset;
 268
 269         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 270                 return -EINVAL;
 271         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 272              offset++)
 273                 if (level == video->brightness->levels[offset]) {
 274                         *state = video->brightness->count - offset - 1;
 275                         return 0;
 276                 }
 277
 278         return -EINVAL;
 279 }
 280
 281 static int
 282 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 283 {
 284         struct acpi_video_device *video = cooling_dev->devdata;
 285         int level;
 286
 287         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 288                 return -EINVAL;
 289
 290         state = video->brightness->count - state;
 291         level = video->brightness->levels[state - 1];
 292         return acpi_video_device_lcd_set_level(video, level);
 293 }
 294
 295 static const struct thermal_cooling_device_ops video_cooling_ops = {
 296         .get_max_state = video_get_max_state,
 297         .get_cur_state = video_get_cur_state,
 298         .set_cur_state = video_set_cur_state,
 299 };
 300
 301 /*
 302  * --------------------------------------------------------------------------
 303  *                             Video Management
 304  * --------------------------------------------------------------------------
 305  */
 306
 307 static int
 308 acpi_video_device_lcd_query_levels(acpi_handle handle,
 309                                    union acpi_object **levels)
 310 {
 311         int status;
 312         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 313         union acpi_object *obj;
 314
 315
 316         *levels = NULL;
 317
 318         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 319         if (ACPI_FAILURE(status))
 320                 return status;
 321         obj = (union acpi_object *)buffer.pointer;
 322         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 323                 acpi_handle_info(handle, "Invalid _BCL data\n");
 324                 status = -EFAULT;
 325                 goto err;
 326         }
 327
 328         *levels = obj;
 329
 330         return 0;
 331
 332 err:
 333         kfree(buffer.pointer);
 334
 335         return status;
 336 }
 337
 338 static int
 339 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 340 {
 341         int status;
 342         int state;
 343
 344         status = acpi_execute_simple_method(device->dev->handle,
 345                                             "_BCM", level);
 346         if (ACPI_FAILURE(status)) {
 347                 acpi_handle_info(device->dev->handle, "_BCM evaluation failed\n");
 348                 return -EIO;
 349         }
 350
 351         device->brightness->curr = level;
 352         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 353              state++)
 354                 if (level == device->brightness->levels[state]) {
 355                         if (device->backlight)
 356                                 device->backlight->props.brightness =
 357                                         state - ACPI_VIDEO_FIRST_LEVEL;
 358                         return 0;
 359                 }
 360
 361         acpi_handle_info(device->dev->handle, "Current brightness invalid\n");
 362         return -EINVAL;
 363 }
 364
 365 /*
 366  * For some buggy _BQC methods, we need to add a constant value to
 367  * the _BQC return value to get the actual current brightness level
 368  */
 369
 370 static int bqc_offset_aml_bug_workaround;
 371 static int video_set_bqc_offset(const struct dmi_system_id *d)
 372 {
 373         bqc_offset_aml_bug_workaround = 9;
 374         return 0;
 375 }
 376
 377 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 378 {
 379         device_id_scheme = true;
 380         return 0;
 381 }
 382
 383 static int video_enable_only_lcd(const struct dmi_system_id *d)
 384 {
 385         only_lcd = true;
 386         return 0;
 387 }
 388
 389 static int video_set_report_key_events(const struct dmi_system_id *id)
 390 {
 391         if (report_key_events == -1)
 392                 report_key_events = (uintptr_t)id->driver_data;
 393         return 0;
 394 }
 395
 396 static int video_hw_changes_brightness(
 397         const struct dmi_system_id *d)
 398 {
 399         if (hw_changes_brightness == -1)
 400                 hw_changes_brightness = 1;
 401         return 0;
 402 }
 403
 404 static const struct dmi_system_id video_dmi_table[] = {
 405         /*
 406          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 407          */
 408         {
 409          .callback = video_set_bqc_offset,
 410          .ident = "Acer Aspire 5720",
 411          .matches = {
 412                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 413                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 414                 },
 415         },
 416         {
 417          .callback = video_set_bqc_offset,
 418          .ident = "Acer Aspire 5710Z",
 419          .matches = {
 420                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 421                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 422                 },
 423         },
 424         {
 425          .callback = video_set_bqc_offset,
 426          .ident = "eMachines E510",
 427          .matches = {
 428                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 429                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 430                 },
 431         },
 432         {
 433          .callback = video_set_bqc_offset,
 434          .ident = "Acer Aspire 5315",
 435          .matches = {
 436                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 437                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 438                 },
 439         },
 440         {
 441          .callback = video_set_bqc_offset,
 442          .ident = "Acer Aspire 7720",
 443          .matches = {
 444                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 445                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 446                 },
 447         },
 448
 449         /*
 450          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 451          * but the IDs actually follow the Device ID Scheme.
 452          */
 453         {
 454          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 455          .callback = video_set_device_id_scheme,
 456          .ident = "ESPRIMO Mobile M9410",
 457          .matches = {
 458                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 459                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 460                 },
 461         },
 462         /*
 463          * Some machines have multiple video output devices, but only the one
 464          * that is the type of LCD can do the backlight control so we should not
 465          * register backlight interface for other video output devices.
 466          */
 467         {
 468          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 469          .callback = video_enable_only_lcd,
 470          .ident = "ESPRIMO Mobile M9410",
 471          .matches = {
 472                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 473                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 474                 },
 475         },
 476         /*
 477          * Some machines report wrong key events on the acpi-bus, suppress
 478          * key event reporting on these.  Note this is only intended to work
 479          * around events which are plain wrong. In some cases we get double
 480          * events, in this case acpi-video is considered the canonical source
 481          * and the events from the other source should be filtered. E.g.
 482          * by calling acpi_video_handles_brightness_key_presses() from the
 483          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 484          */
 485         {
 486          .callback = video_set_report_key_events,
 487          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 488          .ident = "Dell Vostro V131",
 489          .matches = {
 490                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 491                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 492                 },
 493         },
 494         {
 495          .callback = video_set_report_key_events,
 496          .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 497          .ident = "Dell Vostro 3350",
 498          .matches = {
 499                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 500                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3350"),
 501                 },
 502         },
 503         {
 504          .callback = video_set_report_key_events,
 505          .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 506          .ident = "COLORFUL X15 AT 23",
 507          .matches = {
 508                 DMI_MATCH(DMI_SYS_VENDOR, "COLORFUL"),
 509                 DMI_MATCH(DMI_PRODUCT_NAME, "X15 AT 23"),
 510                 },
 511         },
 512         /*
 513          * Some machines change the brightness themselves when a brightness
 514          * hotkey gets pressed, despite us telling them not to. In this case
 515          * acpi_video_device_notify() should only call backlight_force_update(
 516          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 517          */
 518         {
 519          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 520          .callback = video_hw_changes_brightness,
 521          .ident = "Packard Bell EasyNote MZ35",
 522          .matches = {
 523                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 524                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 525                 },
 526         },
 527         {}
 528 };
 529
 530 static unsigned long long
 531 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 532                               unsigned long long bqc_value)
 533 {
 534         unsigned long long level;
 535
 536         if (device->brightness->flags._BQC_use_index) {
 537                 /*
 538                  * _BQC returns an index that doesn't account for the first 2
 539                  * items with special meaning (see enum acpi_video_level_idx),
 540                  * so we need to compensate for that by offsetting ourselves
 541                  */
 542                 if (device->brightness->flags._BCL_reversed)
 543                         bqc_value = device->brightness->count -
 544                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 545
 546                 level = device->brightness->levels[bqc_value +
 547                                                    ACPI_VIDEO_FIRST_LEVEL];
 548         } else {
 549                 level = bqc_value;
 550         }
 551
 552         level += bqc_offset_aml_bug_workaround;
 553
 554         return level;
 555 }
 556
 557 static int
 558 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 559                                         unsigned long long *level, bool raw)
 560 {
 561         acpi_status status = AE_OK;
 562         int i;
 563
 564         if (device->cap._BQC || device->cap._BCQ) {
 565                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 566
 567                 status = acpi_evaluate_integer(device->dev->handle, buf,
 568                                                 NULL, level);
 569                 if (ACPI_SUCCESS(status)) {
 570                         if (raw) {
 571                                 /*
 572                                  * Caller has indicated he wants the raw
 573                                  * value returned by _BQC, so don't furtherly
 574                                  * mess with the value.
 575                                  */
 576                                 return 0;
 577                         }
 578
 579                         *level = acpi_video_bqc_value_to_level(device, *level);
 580
 581                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 582                              i < device->brightness->count; i++)
 583                                 if (device->brightness->levels[i] == *level) {
 584                                         device->brightness->curr = *level;
 585                                         return 0;
 586                                 }
 587                         /*
 588                          * BQC returned an invalid level.
 589                          * Stop using it.
 590                          */
 591                         acpi_handle_info(device->dev->handle,
 592                                          "%s returned an invalid level", buf);
 593                         device->cap._BQC = device->cap._BCQ = 0;
 594                 } else {
 595                         /*
 596                          * Fixme:
 597                          * should we return an error or ignore this failure?
 598                          * dev->brightness->curr is a cached value which stores
 599                          * the correct current backlight level in most cases.
 600                          * ACPI video backlight still works w/ buggy _BQC.
 601                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 602                          */
 603                         acpi_handle_info(device->dev->handle,
 604                                          "%s evaluation failed", buf);
 605                         device->cap._BQC = device->cap._BCQ = 0;
 606                 }
 607         }
 608
 609         *level = device->brightness->curr;
 610         return 0;
 611 }
 612
 613 static int
 614 acpi_video_device_EDID(struct acpi_video_device *device,
 615                        union acpi_object **edid, int length)
 616 {
 617         int status;
 618         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 619         union acpi_object *obj;
 620         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 621         struct acpi_object_list args = { 1, &arg0 };
 622
 623
 624         *edid = NULL;
 625
 626         if (!device)
 627                 return -ENODEV;
 628         if (!length || (length % 128))
 629                 return -EINVAL;
 630
 631         arg0.integer.value = length / 128;
 632
 633         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 634         if (ACPI_FAILURE(status))
 635                 return -ENODEV;
 636
 637         obj = buffer.pointer;
 638
 639         if (obj && obj->type == ACPI_TYPE_BUFFER)
 640                 *edid = obj;
 641         else {
 642                 acpi_handle_debug(device->dev->handle,
 643                                  "Invalid _DDC data for length %d\n", length);
 644                 status = -EFAULT;
 645                 kfree(obj);
 646         }
 647
 648         return status;
 649 }
 650
 651 /* bus */
 652
 653 /*
 654  *  Arg:
 655  *      video           : video bus device pointer
 656  *      bios_flag       :
 657  *              0.      The system BIOS should NOT automatically switch(toggle)
 658  *                      the active display output.
 659  *              1.      The system BIOS should automatically switch (toggle) the
 660  *                      active display output. No switch event.
 661  *              2.      The _DGS value should be locked.
 662  *              3.      The system BIOS should not automatically switch (toggle) the
 663  *                      active display output, but instead generate the display switch
 664  *                      event notify code.
 665  *      lcd_flag        :
 666  *              0.      The system BIOS should automatically control the brightness level
 667  *                      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  *              1.      The system BIOS should NOT automatically control the brightness
 671  *                      level of the LCD when:
 672  *                      - the power changes from AC to DC (ACPI appendix B)
 673  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 674  *  Return Value:
 675  *              -EINVAL wrong arg.
 676  */
 677
 678 static int
 679 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 680 {
 681         acpi_status status;
 682
 683         if (!video->cap._DOS)
 684                 return 0;
 685
 686         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 687                 return -EINVAL;
 688         video->dos_setting = (lcd_flag << 2) | bios_flag;
 689         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 690                                             (lcd_flag << 2) | bios_flag);
 691         if (ACPI_FAILURE(status))
 692                 return -EIO;
 693
 694         return 0;
 695 }
 696
 697 /*
 698  * Simple comparison function used to sort backlight levels.
 699  */
 700
 701 static int
 702 acpi_video_cmp_level(const void *a, const void *b)
 703 {
 704         return *(int *)a - *(int *)b;
 705 }
 706
 707 /*
 708  * Decides if _BQC/_BCQ for this system is usable
 709  *
 710  * We do this by changing the level first and then read out the current
 711  * brightness level, if the value does not match, find out if it is using
 712  * index. If not, clear the _BQC/_BCQ capability.
 713  */
 714 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 715                                 int max_level, int current_level)
 716 {
 717         struct acpi_video_device_brightness *br = device->brightness;
 718         int result;
 719         unsigned long long level;
 720         int test_level;
 721
 722         /* don't mess with existing known broken systems */
 723         if (bqc_offset_aml_bug_workaround)
 724                 return 0;
 725
 726         /*
 727          * Some systems always report current brightness level as maximum
 728          * through _BQC, we need to test another value for them. However,
 729          * there is a subtlety:
 730          *
 731          * If the _BCL package ordering is descending, the first level
 732          * (br->levels[2]) is likely to be 0, and if the number of levels
 733          * matches the number of steps, we might confuse a returned level to
 734          * mean the index.
 735          *
 736          * For example:
 737          *
 738          *     current_level = max_level = 100
 739          *     test_level = 0
 740          *     returned level = 100
 741          *
 742          * In this case 100 means the level, not the index, and _BCM failed.
 743          * Still, if the _BCL package ordering is descending, the index of
 744          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 745          *
 746          * This causes all _BQC calls to return bogus values causing weird
 747          * behavior from the user's perspective.  For example:
 748          *
 749          * xbacklight -set 10; xbacklight -set 20;
 750          *
 751          * would flash to 90% and then slowly down to the desired level (20).
 752          *
 753          * The solution is simple; test anything other than the first level
 754          * (e.g. 1).
 755          */
 756         test_level = current_level == max_level
 757                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 758                 : max_level;
 759
 760         result = acpi_video_device_lcd_set_level(device, test_level);
 761         if (result)
 762                 return result;
 763
 764         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 765         if (result)
 766                 return result;
 767
 768         if (level != test_level) {
 769                 /* buggy _BQC found, need to find out if it uses index */
 770                 if (level < br->count) {
 771                         if (br->flags._BCL_reversed)
 772                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 773                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 774                                 br->flags._BQC_use_index = 1;
 775                 }
 776
 777                 if (!br->flags._BQC_use_index)
 778                         device->cap._BQC = device->cap._BCQ = 0;
 779         }
 780
 781         return 0;
 782 }
 783
 784 int acpi_video_get_levels(struct acpi_device *device,
 785                           struct acpi_video_device_brightness **dev_br,
 786                           int *pmax_level)
 787 {
 788         union acpi_object *obj = NULL;
 789         int i, max_level = 0, count = 0, level_ac_battery = 0;
 790         union acpi_object *o;
 791         struct acpi_video_device_brightness *br = NULL;
 792         int result = 0;
 793         u32 value;
 794
 795         if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
 796                 acpi_handle_debug(device->handle,
 797                                   "Could not query available LCD brightness level\n");
 798                 result = -ENODEV;
 799                 goto out;
 800         }
 801
 802         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 803                 result = -EINVAL;
 804                 goto out;
 805         }
 806
 807         br = kzalloc(sizeof(*br), GFP_KERNEL);
 808         if (!br) {
 809                 result = -ENOMEM;
 810                 goto out;
 811         }
 812
 813         /*
 814          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 815          * in order to account for buggy BIOS which don't export the first two
 816          * special levels (see below)
 817          */
 818         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 819                                    sizeof(*br->levels),
 820                                    GFP_KERNEL);
 821         if (!br->levels) {
 822                 result = -ENOMEM;
 823                 goto out_free;
 824         }
 825
 826         for (i = 0; i < obj->package.count; i++) {
 827                 o = (union acpi_object *)&obj->package.elements[i];
 828                 if (o->type != ACPI_TYPE_INTEGER) {
 829                         acpi_handle_info(device->handle, "Invalid data\n");
 830                         continue;
 831                 }
 832                 value = (u32) o->integer.value;
 833                 /* Skip duplicate entries */
 834                 if (count > ACPI_VIDEO_FIRST_LEVEL
 835                     && br->levels[count - 1] == value)
 836                         continue;
 837
 838                 br->levels[count] = value;
 839
 840                 if (br->levels[count] > max_level)
 841                         max_level = br->levels[count];
 842                 count++;
 843         }
 844
 845         /*
 846          * some buggy BIOS don't export the levels
 847          * when machine is on AC/Battery in _BCL package.
 848          * In this case, the first two elements in _BCL packages
 849          * are also supported brightness levels that OS should take care of.
 850          */
 851         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 852                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 853                         level_ac_battery++;
 854                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 855                         level_ac_battery++;
 856         }
 857
 858         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 859                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 860                 br->flags._BCL_no_ac_battery_levels = 1;
 861                 for (i = (count - 1 + level_ac_battery);
 862                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 863                         br->levels[i] = br->levels[i - level_ac_battery];
 864                 count += level_ac_battery;
 865         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 866                 acpi_handle_info(device->handle,
 867                                  "Too many duplicates in _BCL package");
 868
 869         /* Check if the _BCL package is in a reversed order */
 870         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 871                 br->flags._BCL_reversed = 1;
 872                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 873                      count - ACPI_VIDEO_FIRST_LEVEL,
 874                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 875                      acpi_video_cmp_level, NULL);
 876         } else if (max_level != br->levels[count - 1])
 877                 acpi_handle_info(device->handle,
 878                                  "Found unordered _BCL package");
 879
 880         br->count = count;
 881         *dev_br = br;
 882         if (pmax_level)
 883                 *pmax_level = max_level;
 884
 885 out:
 886         kfree(obj);
 887         return result;
 888 out_free:
 889         kfree(br);
 890         goto out;
 891 }
 892 EXPORT_SYMBOL(acpi_video_get_levels);
 893
 894 /*
 895  *  Arg:
 896  *      device  : video output device (LCD, CRT, ..)
 897  *
 898  *  Return Value:
 899  *      Maximum brightness level
 900  *
 901  *  Allocate and initialize device->brightness.
 902  */
 903
 904 static int
 905 acpi_video_init_brightness(struct acpi_video_device *device)
 906 {
 907         int i, max_level = 0;
 908         unsigned long long level, level_old;
 909         struct acpi_video_device_brightness *br = NULL;
 910         int result;
 911
 912         result = acpi_video_get_levels(device->dev, &br, &max_level);
 913         if (result)
 914                 return result;
 915         device->brightness = br;
 916
 917         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 918         br->curr = level = max_level;
 919
 920         if (!device->cap._BQC)
 921                 goto set_level;
 922
 923         result = acpi_video_device_lcd_get_level_current(device,
 924                                                          &level_old, true);
 925         if (result)
 926                 goto out_free_levels;
 927
 928         result = acpi_video_bqc_quirk(device, max_level, level_old);
 929         if (result)
 930                 goto out_free_levels;
 931         /*
 932          * cap._BQC may get cleared due to _BQC is found to be broken
 933          * in acpi_video_bqc_quirk, so check again here.
 934          */
 935         if (!device->cap._BQC)
 936                 goto set_level;
 937
 938         level = acpi_video_bqc_value_to_level(device, level_old);
 939         /*
 940          * On some buggy laptops, _BQC returns an uninitialized
 941          * value when invoked for the first time, i.e.
 942          * level_old is invalid (no matter whether it's a level
 943          * or an index). Set the backlight to max_level in this case.
 944          */
 945         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 946                 if (level == br->levels[i])
 947                         break;
 948         if (i == br->count || !level)
 949                 level = max_level;
 950
 951 set_level:
 952         result = acpi_video_device_lcd_set_level(device, level);
 953         if (result)
 954                 goto out_free_levels;
 955
 956         acpi_handle_debug(device->dev->handle, "found %d brightness levels\n",
 957                           br->count - ACPI_VIDEO_FIRST_LEVEL);
 958
 959         return 0;
 960
 961 out_free_levels:
 962         kfree(br->levels);
 963         kfree(br);
 964         device->brightness = NULL;
 965         return result;
 966 }
 967
 968 /*
 969  *  Arg:
 970  *      device  : video output device (LCD, CRT, ..)
 971  *
 972  *  Return Value:
 973  *      None
 974  *
 975  *  Find out all required AML methods defined under the output
 976  *  device.
 977  */
 978
 979 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 980 {
 981         if (acpi_has_method(device->dev->handle, "_ADR"))
 982                 device->cap._ADR = 1;
 983         if (acpi_has_method(device->dev->handle, "_BCL"))
 984                 device->cap._BCL = 1;
 985         if (acpi_has_method(device->dev->handle, "_BCM"))
 986                 device->cap._BCM = 1;
 987         if (acpi_has_method(device->dev->handle, "_BQC")) {
 988                 device->cap._BQC = 1;
 989         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 990                 acpi_handle_info(device->dev->handle,
 991                                  "_BCQ is used instead of _BQC\n");
 992                 device->cap._BCQ = 1;
 993         }
 994
 995         if (acpi_has_method(device->dev->handle, "_DDC"))
 996                 device->cap._DDC = 1;
 997 }
 998
 999 /*
1000  *  Arg:
1001  *      device  : video output device (VGA)
1002  *
1003  *  Return Value:
1004  *      None
1005  *
1006  *  Find out all required AML methods defined under the video bus device.
1007  */
1008
1009 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1010 {
1011         if (acpi_has_method(video->device->handle, "_DOS"))
1012                 video->cap._DOS = 1;
1013         if (acpi_has_method(video->device->handle, "_DOD"))
1014                 video->cap._DOD = 1;
1015         if (acpi_has_method(video->device->handle, "_ROM"))
1016                 video->cap._ROM = 1;
1017         if (acpi_has_method(video->device->handle, "_GPD"))
1018                 video->cap._GPD = 1;
1019         if (acpi_has_method(video->device->handle, "_SPD"))
1020                 video->cap._SPD = 1;
1021         if (acpi_has_method(video->device->handle, "_VPO"))
1022                 video->cap._VPO = 1;
1023 }
1024
1025 /*
1026  * Check whether the video bus device has required AML method to
1027  * support the desired features
1028  */
1029
1030 static int acpi_video_bus_check(struct acpi_video_bus *video)
1031 {
1032         acpi_status status = -ENOENT;
1033         struct pci_dev *dev;
1034
1035         if (!video)
1036                 return -EINVAL;
1037
1038         dev = acpi_get_pci_dev(video->device->handle);
1039         if (!dev)
1040                 return -ENODEV;
1041         pci_dev_put(dev);
1042
1043         /*
1044          * Since there is no HID, CID and so on for VGA driver, we have
1045          * to check well known required nodes.
1046          */
1047
1048         /* Does this device support video switching? */
1049         if (video->cap._DOS || video->cap._DOD) {
1050                 if (!video->cap._DOS) {
1051                         pr_info(FW_BUG "ACPI(%s) defines _DOD but not _DOS\n",
1052                                 acpi_device_bid(video->device));
1053                 }
1054                 video->flags.multihead = 1;
1055                 status = 0;
1056         }
1057
1058         /* Does this device support retrieving a video ROM? */
1059         if (video->cap._ROM) {
1060                 video->flags.rom = 1;
1061                 status = 0;
1062         }
1063
1064         /* Does this device support configuring which video device to POST? */
1065         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1066                 video->flags.post = 1;
1067                 status = 0;
1068         }
1069
1070         return status;
1071 }
1072
1073 /*
1074  * --------------------------------------------------------------------------
1075  *                               Driver Interface
1076  * --------------------------------------------------------------------------
1077  */
1078
1079 /* device interface */
1080 static struct acpi_video_device_attrib *
1081 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1082 {
1083         struct acpi_video_enumerated_device *ids;
1084         int i;
1085
1086         for (i = 0; i < video->attached_count; i++) {
1087                 ids = &video->attached_array[i];
1088                 if ((ids->value.int_val & 0xffff) == device_id)
1089                         return &ids->value.attrib;
1090         }
1091
1092         return NULL;
1093 }
1094
1095 static int
1096 acpi_video_get_device_type(struct acpi_video_bus *video,
1097                            unsigned long device_id)
1098 {
1099         struct acpi_video_enumerated_device *ids;
1100         int i;
1101
1102         for (i = 0; i < video->attached_count; i++) {
1103                 ids = &video->attached_array[i];
1104                 if ((ids->value.int_val & 0xffff) == device_id)
1105                         return ids->value.int_val;
1106         }
1107
1108         return 0;
1109 }
1110
1111 static int acpi_video_bus_get_one_device(struct acpi_device *device, void *arg)
1112 {
1113         struct acpi_video_bus *video = arg;
1114         struct acpi_video_device_attrib *attribute;
1115         struct acpi_video_device *data;
1116         unsigned long long device_id;
1117         acpi_status status;
1118         int device_type;
1119
1120         status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1121         /* Skip devices without _ADR instead of failing. */
1122         if (ACPI_FAILURE(status))
1123                 goto exit;
1124
1125         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1126         if (!data) {
1127                 dev_dbg(&device->dev, "Cannot attach\n");
1128                 return -ENOMEM;
1129         }
1130
1131         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1132         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1133
1134         data->device_id = device_id;
1135         data->video = video;
1136         data->dev = device;
1137         INIT_DELAYED_WORK(&data->switch_brightness_work,
1138                           acpi_video_switch_brightness);
1139
1140         attribute = acpi_video_get_device_attr(video, device_id);
1141
1142         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1143                 switch (attribute->display_type) {
1144                 case ACPI_VIDEO_DISPLAY_CRT:
1145                         data->flags.crt = 1;
1146                         break;
1147                 case ACPI_VIDEO_DISPLAY_TV:
1148                         data->flags.tvout = 1;
1149                         break;
1150                 case ACPI_VIDEO_DISPLAY_DVI:
1151                         data->flags.dvi = 1;
1152                         break;
1153                 case ACPI_VIDEO_DISPLAY_LCD:
1154                         data->flags.lcd = 1;
1155                         break;
1156                 default:
1157                         data->flags.unknown = 1;
1158                         break;
1159                 }
1160                 if (attribute->bios_can_detect)
1161                         data->flags.bios = 1;
1162         } else {
1163                 /* Check for legacy IDs */
1164                 device_type = acpi_video_get_device_type(video, device_id);
1165                 /* Ignore bits 16 and 18-20 */
1166                 switch (device_type & 0xffe2ffff) {
1167                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1168                         data->flags.crt = 1;
1169                         break;
1170                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1171                         data->flags.lcd = 1;
1172                         break;
1173                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1174                         data->flags.tvout = 1;
1175                         break;
1176                 default:
1177                         data->flags.unknown = 1;
1178                 }
1179         }
1180
1181         acpi_video_device_bind(video, data);
1182         acpi_video_device_find_cap(data);
1183
1184         if (data->cap._BCM && data->cap._BCL)
1185                 may_report_brightness_keys = true;
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 exit:
1192         video->child_count++;
1193         return 0;
1194 }
1195
1196 /*
1197  *  Arg:
1198  *      video   : video bus device
1199  *
1200  *  Return:
1201  *      none
1202  *
1203  *  Enumerate the video device list of the video bus,
1204  *  bind the ids with the corresponding video devices
1205  *  under the video bus.
1206  */
1207
1208 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1209 {
1210         struct acpi_video_device *dev;
1211
1212         mutex_lock(&video->device_list_lock);
1213
1214         list_for_each_entry(dev, &video->video_device_list, entry)
1215                 acpi_video_device_bind(video, dev);
1216
1217         mutex_unlock(&video->device_list_lock);
1218 }
1219
1220 /*
1221  *  Arg:
1222  *      video   : video bus device
1223  *      device  : video output device under the video
1224  *              bus
1225  *
1226  *  Return:
1227  *      none
1228  *
1229  *  Bind the ids with the corresponding video devices
1230  *  under the video bus.
1231  */
1232
1233 static void
1234 acpi_video_device_bind(struct acpi_video_bus *video,
1235                        struct acpi_video_device *device)
1236 {
1237         struct acpi_video_enumerated_device *ids;
1238         int i;
1239
1240         for (i = 0; i < video->attached_count; i++) {
1241                 ids = &video->attached_array[i];
1242                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1243                         ids->bind_info = device;
1244                         acpi_handle_debug(video->device->handle, "%s: %d\n",
1245                                           __func__, i);
1246                 }
1247         }
1248 }
1249
1250 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1251 {
1252         struct acpi_video_bus *video = device->video;
1253         int i;
1254
1255         /*
1256          * If we have a broken _DOD or we have more than 8 output devices
1257          * under the graphics controller node that we can't proper deal with
1258          * in the operation region code currently, no need to test.
1259          */
1260         if (!video->attached_count || video->child_count > 8)
1261                 return true;
1262
1263         for (i = 0; i < video->attached_count; i++) {
1264                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1265                     (device->device_id & 0xfff))
1266                         return true;
1267         }
1268
1269         return false;
1270 }
1271
1272 /*
1273  *  Arg:
1274  *      video   : video bus device
1275  *
1276  *  Return:
1277  *      < 0     : error
1278  *
1279  *  Call _DOD to enumerate all devices attached to display adapter
1280  *
1281  */
1282
1283 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1284 {
1285         int status;
1286         int count;
1287         int i;
1288         struct acpi_video_enumerated_device *active_list;
1289         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1290         union acpi_object *dod = NULL;
1291         union acpi_object *obj;
1292
1293         if (!video->cap._DOD)
1294                 return AE_NOT_EXIST;
1295
1296         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1297         if (ACPI_FAILURE(status)) {
1298                 acpi_handle_info(video->device->handle,
1299                                  "_DOD evaluation failed: %s\n",
1300                                  acpi_format_exception(status));
1301                 return status;
1302         }
1303
1304         dod = buffer.pointer;
1305         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1306                 acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1307                 status = -EFAULT;
1308                 goto out;
1309         }
1310
1311         acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1312                           dod->package.count);
1313
1314         active_list = kcalloc(1 + dod->package.count,
1315                               sizeof(struct acpi_video_enumerated_device),
1316                               GFP_KERNEL);
1317         if (!active_list) {
1318                 status = -ENOMEM;
1319                 goto out;
1320         }
1321
1322         count = 0;
1323         for (i = 0; i < dod->package.count; i++) {
1324                 obj = &dod->package.elements[i];
1325
1326                 if (obj->type != ACPI_TYPE_INTEGER) {
1327                         acpi_handle_info(video->device->handle,
1328                                          "Invalid _DOD data in element %d\n", i);
1329                         continue;
1330                 }
1331
1332                 active_list[count].value.int_val = obj->integer.value;
1333                 active_list[count].bind_info = NULL;
1334
1335                 acpi_handle_debug(video->device->handle,
1336                                   "_DOD element[%d] = %d\n", i,
1337                                   (int)obj->integer.value);
1338
1339                 count++;
1340         }
1341
1342         kfree(video->attached_array);
1343
1344         video->attached_array = active_list;
1345         video->attached_count = count;
1346
1347 out:
1348         kfree(buffer.pointer);
1349         return status;
1350 }
1351
1352 static int
1353 acpi_video_get_next_level(struct acpi_video_device *device,
1354                           u32 level_current, u32 event)
1355 {
1356         int min, max, min_above, max_below, i, l, delta = 255;
1357         max = max_below = 0;
1358         min = min_above = 255;
1359         /* Find closest level to level_current */
1360         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1361                 l = device->brightness->levels[i];
1362                 if (abs(l - level_current) < abs(delta)) {
1363                         delta = l - level_current;
1364                         if (!delta)
1365                                 break;
1366                 }
1367         }
1368         /* Adjust level_current to closest available level */
1369         level_current += delta;
1370         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1371                 l = device->brightness->levels[i];
1372                 if (l < min)
1373                         min = l;
1374                 if (l > max)
1375                         max = l;
1376                 if (l < min_above && l > level_current)
1377                         min_above = l;
1378                 if (l > max_below && l < level_current)
1379                         max_below = l;
1380         }
1381
1382         switch (event) {
1383         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1384                 return (level_current < max) ? min_above : min;
1385         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1386                 return (level_current < max) ? min_above : max;
1387         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1388                 return (level_current > min) ? max_below : min;
1389         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1390         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1391                 return 0;
1392         default:
1393                 return level_current;
1394         }
1395 }
1396
1397 static void
1398 acpi_video_switch_brightness(struct work_struct *work)
1399 {
1400         struct acpi_video_device *device = container_of(to_delayed_work(work),
1401                              struct acpi_video_device, switch_brightness_work);
1402         unsigned long long level_current, level_next;
1403         int event = device->switch_brightness_event;
1404         int result = -EINVAL;
1405
1406         /* no warning message if acpi_backlight=vendor or a quirk is used */
1407         if (!device->backlight)
1408                 return;
1409
1410         if (!device->brightness)
1411                 goto out;
1412
1413         result = acpi_video_device_lcd_get_level_current(device,
1414                                                          &level_current,
1415                                                          false);
1416         if (result)
1417                 goto out;
1418
1419         level_next = acpi_video_get_next_level(device, level_current, event);
1420
1421         result = acpi_video_device_lcd_set_level(device, level_next);
1422
1423         if (!result)
1424                 backlight_force_update(device->backlight,
1425                                        BACKLIGHT_UPDATE_HOTKEY);
1426
1427 out:
1428         if (result)
1429                 acpi_handle_info(device->dev->handle,
1430                                  "Failed to switch brightness\n");
1431 }
1432
1433 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1434                         void **edid)
1435 {
1436         struct acpi_video_bus *video;
1437         struct acpi_video_device *video_device;
1438         union acpi_object *buffer = NULL;
1439         acpi_status status;
1440         int i, length;
1441
1442         if (!device || !acpi_driver_data(device))
1443                 return -EINVAL;
1444
1445         video = acpi_driver_data(device);
1446
1447         for (i = 0; i < video->attached_count; i++) {
1448                 video_device = video->attached_array[i].bind_info;
1449
1450                 if (!video_device)
1451                         continue;
1452
1453                 if (!video_device->cap._DDC)
1454                         continue;
1455
1456                 if (type) {
1457                         switch (type) {
1458                         case ACPI_VIDEO_DISPLAY_CRT:
1459                                 if (!video_device->flags.crt)
1460                                         continue;
1461                                 break;
1462                         case ACPI_VIDEO_DISPLAY_TV:
1463                                 if (!video_device->flags.tvout)
1464                                         continue;
1465                                 break;
1466                         case ACPI_VIDEO_DISPLAY_DVI:
1467                                 if (!video_device->flags.dvi)
1468                                         continue;
1469                                 break;
1470                         case ACPI_VIDEO_DISPLAY_LCD:
1471                                 if (!video_device->flags.lcd)
1472                                         continue;
1473                                 break;
1474                         }
1475                 } else if (video_device->device_id != device_id) {
1476                         continue;
1477                 }
1478
1479                 for (length = 512; length > 0; length -= 128) {
1480                         status = acpi_video_device_EDID(video_device, &buffer,
1481                                                         length);
1482                         if (ACPI_SUCCESS(status))
1483                                 break;
1484                 }
1485                 if (!length)
1486                         continue;
1487
1488                 *edid = buffer->buffer.pointer;
1489                 return length;
1490         }
1491
1492         return -ENODEV;
1493 }
1494 EXPORT_SYMBOL(acpi_video_get_edid);
1495
1496 static int
1497 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1498                            struct acpi_device *device)
1499 {
1500         /*
1501          * There are systems where video module known to work fine regardless
1502          * of broken _DOD and ignoring returned value here doesn't cause
1503          * any issues later.
1504          */
1505         acpi_video_device_enumerate(video);
1506
1507         return acpi_dev_for_each_child(device, acpi_video_bus_get_one_device, video);
1508 }
1509
1510 /* acpi_video interface */
1511
1512 /*
1513  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1514  * perform any automatic brightness change on receiving a notification.
1515  */
1516 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1517 {
1518         return acpi_video_bus_DOS(video, 0,
1519                                   acpi_osi_is_win8() ? 1 : 0);
1520 }
1521
1522 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1523 {
1524         return acpi_video_bus_DOS(video, 0,
1525                                   acpi_osi_is_win8() ? 0 : 1);
1526 }
1527
1528 static void acpi_video_bus_notify(acpi_handle handle, u32 event, void *data)
1529 {
1530         struct acpi_device *device = data;
1531         struct acpi_video_bus *video = acpi_driver_data(device);
1532         struct input_dev *input;
1533         int keycode = 0;
1534
1535         if (!video || !video->input)
1536                 return;
1537
1538         input = video->input;
1539
1540         switch (event) {
1541         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1542                                          * most likely via hotkey. */
1543                 keycode = KEY_SWITCHVIDEOMODE;
1544                 break;
1545
1546         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1547                                          * connector. */
1548                 acpi_video_device_enumerate(video);
1549                 acpi_video_device_rebind(video);
1550                 keycode = KEY_SWITCHVIDEOMODE;
1551                 break;
1552
1553         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1554                 keycode = KEY_SWITCHVIDEOMODE;
1555                 break;
1556         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1557                 keycode = KEY_VIDEO_NEXT;
1558                 break;
1559         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1560                 keycode = KEY_VIDEO_PREV;
1561                 break;
1562
1563         default:
1564                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1565                                   event);
1566                 break;
1567         }
1568
1569         if (acpi_notifier_call_chain(device, event, 0))
1570                 /* Something vetoed the keypress. */
1571                 keycode = 0;
1572
1573         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1574                 input_report_key(input, keycode, 1);
1575                 input_sync(input);
1576                 input_report_key(input, keycode, 0);
1577                 input_sync(input);
1578         }
1579 }
1580
1581 static void brightness_switch_event(struct acpi_video_device *video_device,
1582                                     u32 event)
1583 {
1584         if (!brightness_switch_enabled)
1585                 return;
1586
1587         video_device->switch_brightness_event = event;
1588         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1589 }
1590
1591 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1592 {
1593         struct acpi_video_device *video_device = data;
1594         struct acpi_device *device = NULL;
1595         struct acpi_video_bus *bus;
1596         struct input_dev *input;
1597         int keycode = 0;
1598
1599         if (!video_device)
1600                 return;
1601
1602         device = video_device->dev;
1603         bus = video_device->video;
1604         input = bus->input;
1605
1606         if (hw_changes_brightness > 0) {
1607                 if (video_device->backlight)
1608                         backlight_force_update(video_device->backlight,
1609                                                BACKLIGHT_UPDATE_HOTKEY);
1610                 acpi_notifier_call_chain(device, event, 0);
1611                 return;
1612         }
1613
1614         switch (event) {
1615         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1616                 brightness_switch_event(video_device, event);
1617                 keycode = KEY_BRIGHTNESS_CYCLE;
1618                 break;
1619         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1620                 brightness_switch_event(video_device, event);
1621                 keycode = KEY_BRIGHTNESSUP;
1622                 break;
1623         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1624                 brightness_switch_event(video_device, event);
1625                 keycode = KEY_BRIGHTNESSDOWN;
1626                 break;
1627         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1628                 brightness_switch_event(video_device, event);
1629                 keycode = KEY_BRIGHTNESS_ZERO;
1630                 break;
1631         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1632                 brightness_switch_event(video_device, event);
1633                 keycode = KEY_DISPLAY_OFF;
1634                 break;
1635         default:
1636                 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1637                 break;
1638         }
1639
1640         if (keycode)
1641                 may_report_brightness_keys = true;
1642
1643         acpi_notifier_call_chain(device, event, 0);
1644
1645         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1646                 input_report_key(input, keycode, 1);
1647                 input_sync(input);
1648                 input_report_key(input, keycode, 0);
1649                 input_sync(input);
1650         }
1651 }
1652
1653 static int acpi_video_resume(struct notifier_block *nb,
1654                                 unsigned long val, void *ign)
1655 {
1656         struct acpi_video_bus *video;
1657         struct acpi_video_device *video_device;
1658         int i;
1659
1660         switch (val) {
1661         case PM_POST_HIBERNATION:
1662         case PM_POST_SUSPEND:
1663         case PM_POST_RESTORE:
1664                 video = container_of(nb, struct acpi_video_bus, pm_nb);
1665
1666                 dev_info(&video->device->dev, "Restoring backlight state\n");
1667
1668                 for (i = 0; i < video->attached_count; i++) {
1669                         video_device = video->attached_array[i].bind_info;
1670                         if (video_device && video_device->brightness)
1671                                 acpi_video_device_lcd_set_level(video_device,
1672                                                 video_device->brightness->curr);
1673                 }
1674
1675                 return NOTIFY_OK;
1676         }
1677         return NOTIFY_DONE;
1678 }
1679
1680 static acpi_status
1681 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1682                         void **return_value)
1683 {
1684         struct acpi_device *device = context;
1685         struct acpi_device *sibling;
1686
1687         if (handle == device->handle)
1688                 return AE_CTRL_TERMINATE;
1689
1690         sibling = acpi_fetch_acpi_dev(handle);
1691         if (!sibling)
1692                 return AE_OK;
1693
1694         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1695                         return AE_ALREADY_EXISTS;
1696
1697         return AE_OK;
1698 }
1699
1700 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1701 {
1702         struct backlight_properties props;
1703         struct pci_dev *pdev;
1704         acpi_handle acpi_parent;
1705         struct device *parent = NULL;
1706         int result;
1707         static int count;
1708         char *name;
1709
1710         result = acpi_video_init_brightness(device);
1711         if (result)
1712                 return;
1713
1714         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1715         if (!name)
1716                 return;
1717         count++;
1718
1719         if (ACPI_SUCCESS(acpi_get_parent(device->dev->handle, &acpi_parent))) {
1720                 pdev = acpi_get_pci_dev(acpi_parent);
1721                 if (pdev) {
1722                         parent = &pdev->dev;
1723                         pci_dev_put(pdev);
1724                 }
1725         }
1726
1727         memset(&props, 0, sizeof(struct backlight_properties));
1728         props.type = BACKLIGHT_FIRMWARE;
1729         props.max_brightness =
1730                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1731         device->backlight = backlight_device_register(name,
1732                                                       parent,
1733                                                       device,
1734                                                       &acpi_backlight_ops,
1735                                                       &props);
1736         kfree(name);
1737         if (IS_ERR(device->backlight)) {
1738                 device->backlight = NULL;
1739                 return;
1740         }
1741
1742         /*
1743          * Save current brightness level in case we have to restore it
1744          * before acpi_video_device_lcd_set_level() is called next time.
1745          */
1746         device->backlight->props.brightness =
1747                         acpi_video_get_brightness(device->backlight);
1748
1749         device->cooling_dev = thermal_cooling_device_register("LCD", device,
1750                                                               &video_cooling_ops);
1751         if (IS_ERR(device->cooling_dev)) {
1752                 /*
1753                  * Set cooling_dev to NULL so we don't crash trying to free it.
1754                  * Also, why the hell we are returning early and not attempt to
1755                  * register video output if cooling device registration failed?
1756                  * -- dtor
1757                  */
1758                 device->cooling_dev = NULL;
1759                 return;
1760         }
1761
1762         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1763                  device->cooling_dev->id);
1764         result = sysfs_create_link(&device->dev->dev.kobj,
1765                         &device->cooling_dev->device.kobj,
1766                         "thermal_cooling");
1767         if (result)
1768                 pr_info("sysfs link creation failed\n");
1769
1770         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1771                         &device->dev->dev.kobj, "device");
1772         if (result)
1773                 pr_info("Reverse sysfs link creation failed\n");
1774 }
1775
1776 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1777 {
1778         struct acpi_video_device *dev;
1779         union acpi_object *levels;
1780
1781         mutex_lock(&video->device_list_lock);
1782         list_for_each_entry(dev, &video->video_device_list, entry) {
1783                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1784                         kfree(levels);
1785         }
1786         mutex_unlock(&video->device_list_lock);
1787 }
1788
1789 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1790 {
1791         /*
1792          * Do not create backlight device for video output
1793          * device that is not in the enumerated list.
1794          */
1795         if (!acpi_video_device_in_dod(dev)) {
1796                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1797                 return false;
1798         }
1799
1800         if (only_lcd)
1801                 return dev->flags.lcd;
1802         return true;
1803 }
1804
1805 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1806 {
1807         struct acpi_video_device *dev;
1808
1809         if (video->backlight_registered)
1810                 return 0;
1811
1812         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1813                 return 0;
1814
1815         mutex_lock(&video->device_list_lock);
1816         list_for_each_entry(dev, &video->video_device_list, entry) {
1817                 if (acpi_video_should_register_backlight(dev))
1818                         acpi_video_dev_register_backlight(dev);
1819         }
1820         mutex_unlock(&video->device_list_lock);
1821
1822         video->backlight_registered = true;
1823
1824         video->pm_nb.notifier_call = acpi_video_resume;
1825         video->pm_nb.priority = 0;
1826         return register_pm_notifier(&video->pm_nb);
1827 }
1828
1829 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1830 {
1831         if (device->backlight) {
1832                 backlight_device_unregister(device->backlight);
1833                 device->backlight = NULL;
1834         }
1835         if (device->brightness) {
1836                 kfree(device->brightness->levels);
1837                 kfree(device->brightness);
1838                 device->brightness = NULL;
1839         }
1840         if (device->cooling_dev) {
1841                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1842                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1843                 thermal_cooling_device_unregister(device->cooling_dev);
1844                 device->cooling_dev = NULL;
1845         }
1846 }
1847
1848 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1849 {
1850         struct acpi_video_device *dev;
1851         int error;
1852
1853         if (!video->backlight_registered)
1854                 return 0;
1855
1856         error = unregister_pm_notifier(&video->pm_nb);
1857
1858         mutex_lock(&video->device_list_lock);
1859         list_for_each_entry(dev, &video->video_device_list, entry)
1860                 acpi_video_dev_unregister_backlight(dev);
1861         mutex_unlock(&video->device_list_lock);
1862
1863         video->backlight_registered = false;
1864
1865         return error;
1866 }
1867
1868 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1869 {
1870         acpi_status status;
1871         struct acpi_device *adev = device->dev;
1872
1873         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1874                                              acpi_video_device_notify, device);
1875         if (ACPI_FAILURE(status))
1876                 dev_err(&adev->dev, "Error installing notify handler\n");
1877         else
1878                 device->flags.notify = 1;
1879 }
1880
1881 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1882 {
1883         struct input_dev *input;
1884         struct acpi_video_device *dev;
1885         int error;
1886
1887         video->input = input = input_allocate_device();
1888         if (!input) {
1889                 error = -ENOMEM;
1890                 goto out;
1891         }
1892
1893         error = acpi_video_bus_start_devices(video);
1894         if (error)
1895                 goto err_free_input;
1896
1897         snprintf(video->phys, sizeof(video->phys),
1898                         "%s/video/input0", acpi_device_hid(video->device));
1899
1900         input->name = acpi_device_name(video->device);
1901         input->phys = video->phys;
1902         input->id.bustype = BUS_HOST;
1903         input->id.product = 0x06;
1904         input->dev.parent = &video->device->dev;
1905         input->evbit[0] = BIT(EV_KEY);
1906         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1907         set_bit(KEY_VIDEO_NEXT, input->keybit);
1908         set_bit(KEY_VIDEO_PREV, input->keybit);
1909         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1910         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1911         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1912         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1913         set_bit(KEY_DISPLAY_OFF, input->keybit);
1914
1915         error = input_register_device(input);
1916         if (error)
1917                 goto err_stop_dev;
1918
1919         mutex_lock(&video->device_list_lock);
1920         list_for_each_entry(dev, &video->video_device_list, entry)
1921                 acpi_video_dev_add_notify_handler(dev);
1922         mutex_unlock(&video->device_list_lock);
1923
1924         return 0;
1925
1926 err_stop_dev:
1927         acpi_video_bus_stop_devices(video);
1928 err_free_input:
1929         input_free_device(input);
1930         video->input = NULL;
1931 out:
1932         return error;
1933 }
1934
1935 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1936 {
1937         if (dev->flags.notify) {
1938                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1939                                            acpi_video_device_notify);
1940                 dev->flags.notify = 0;
1941         }
1942 }
1943
1944 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1945 {
1946         struct acpi_video_device *dev;
1947
1948         mutex_lock(&video->device_list_lock);
1949         list_for_each_entry(dev, &video->video_device_list, entry)
1950                 acpi_video_dev_remove_notify_handler(dev);
1951         mutex_unlock(&video->device_list_lock);
1952
1953         acpi_video_bus_stop_devices(video);
1954         input_unregister_device(video->input);
1955         video->input = NULL;
1956 }
1957
1958 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1959 {
1960         struct acpi_video_device *dev, *next;
1961
1962         mutex_lock(&video->device_list_lock);
1963         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1964                 list_del(&dev->entry);
1965                 kfree(dev);
1966         }
1967         mutex_unlock(&video->device_list_lock);
1968
1969         return 0;
1970 }
1971
1972 static int instance;
1973
1974 static int acpi_video_bus_add(struct acpi_device *device)
1975 {
1976         struct acpi_video_bus *video;
1977         bool auto_detect;
1978         int error;
1979         acpi_status status;
1980
1981         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1982                                 acpi_dev_parent(device)->handle, 1,
1983                                 acpi_video_bus_match, NULL,
1984                                 device, NULL);
1985         if (status == AE_ALREADY_EXISTS) {
1986                 pr_info(FW_BUG
1987                         "Duplicate ACPI video bus devices for the"
1988                         " same VGA controller, please try module "
1989                         "parameter \"video.allow_duplicates=1\""
1990                         "if the current driver doesn't work.\n");
1991                 if (!allow_duplicates)
1992                         return -ENODEV;
1993         }
1994
1995         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1996         if (!video)
1997                 return -ENOMEM;
1998
1999         /* a hack to fix the duplicate name "VID" problem on T61 */
2000         if (!strcmp(device->pnp.bus_id, "VID")) {
2001                 if (instance)
2002                         device->pnp.bus_id[3] = '0' + instance;
2003                 instance++;
2004         }
2005         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2006         if (!strcmp(device->pnp.bus_id, "VGA")) {
2007                 if (instance)
2008                         device->pnp.bus_id[3] = '0' + instance;
2009                 instance++;
2010         }
2011
2012         video->device = device;
2013         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2014         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2015         device->driver_data = video;
2016
2017         acpi_video_bus_find_cap(video);
2018         error = acpi_video_bus_check(video);
2019         if (error)
2020                 goto err_free_video;
2021
2022         mutex_init(&video->device_list_lock);
2023         INIT_LIST_HEAD(&video->video_device_list);
2024
2025         error = acpi_video_bus_get_devices(video, device);
2026         if (error)
2027                 goto err_put_video;
2028
2029         /*
2030          * HP ZBook Fury 16 G10 requires ACPI video's child devices have _PS0
2031          * evaluated to have functional panel brightness control.
2032          */
2033         acpi_device_fix_up_power_children(device);
2034
2035         pr_info("%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         /*
2045          * If backlight-type auto-detection is used then a native backlight may
2046          * show up later and this may change the result from video to native.
2047          * Therefor normally the userspace visible /sys/class/backlight device
2048          * gets registered separately by the GPU driver calling
2049          * acpi_video_register_backlight() when an internal panel is detected.
2050          * Register the backlight now when not using auto-detection, so that
2051          * when the kernel cmdline or DMI-quirks are used the backlight will
2052          * get registered even if acpi_video_register_backlight() is not called.
2053          */
2054         acpi_video_run_bcl_for_osi(video);
2055         if (__acpi_video_get_backlight_type(false, &auto_detect) == acpi_backlight_video &&
2056             !auto_detect)
2057                 acpi_video_bus_register_backlight(video);
2058
2059         error = acpi_video_bus_add_notify_handler(video);
2060         if (error)
2061                 goto err_del;
2062
2063         error = acpi_dev_install_notify_handler(device, ACPI_DEVICE_NOTIFY,
2064                                                 acpi_video_bus_notify, device);
2065         if (error)
2066                 goto err_remove;
2067
2068         return 0;
2069
2070 err_remove:
2071         acpi_video_bus_remove_notify_handler(video);
2072 err_del:
2073         mutex_lock(&video_list_lock);
2074         list_del(&video->entry);
2075         mutex_unlock(&video_list_lock);
2076         acpi_video_bus_unregister_backlight(video);
2077 err_put_video:
2078         acpi_video_bus_put_devices(video);
2079         kfree(video->attached_array);
2080 err_free_video:
2081         kfree(video);
2082         device->driver_data = NULL;
2083
2084         return error;
2085 }
2086
2087 static void acpi_video_bus_remove(struct acpi_device *device)
2088 {
2089         struct acpi_video_bus *video = NULL;
2090
2091
2092         if (!device || !acpi_driver_data(device))
2093                 return;
2094
2095         video = acpi_driver_data(device);
2096
2097         acpi_dev_remove_notify_handler(device, ACPI_DEVICE_NOTIFY,
2098                                        acpi_video_bus_notify);
2099
2100         mutex_lock(&video_list_lock);
2101         list_del(&video->entry);
2102         mutex_unlock(&video_list_lock);
2103
2104         acpi_video_bus_remove_notify_handler(video);
2105         acpi_video_bus_unregister_backlight(video);
2106         acpi_video_bus_put_devices(video);
2107
2108         kfree(video->attached_array);
2109         kfree(video);
2110 }
2111
2112 static int __init is_i740(struct pci_dev *dev)
2113 {
2114         if (dev->device == 0x00D1)
2115                 return 1;
2116         if (dev->device == 0x7000)
2117                 return 1;
2118         return 0;
2119 }
2120
2121 static int __init intel_opregion_present(void)
2122 {
2123         int opregion = 0;
2124         struct pci_dev *dev = NULL;
2125         u32 address;
2126
2127         for_each_pci_dev(dev) {
2128                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2129                         continue;
2130                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2131                         continue;
2132                 /* We don't want to poke around undefined i740 registers */
2133                 if (is_i740(dev))
2134                         continue;
2135                 pci_read_config_dword(dev, 0xfc, &address);
2136                 if (!address)
2137                         continue;
2138                 opregion = 1;
2139         }
2140         return opregion;
2141 }
2142
2143 int acpi_video_register(void)
2144 {
2145         int ret = 0;
2146
2147         mutex_lock(&register_count_mutex);
2148         if (register_count) {
2149                 /*
2150                  * if the function of acpi_video_register is already called,
2151                  * don't register the acpi_video_bus again and return no error.
2152                  */
2153                 goto leave;
2154         }
2155
2156         dmi_check_system(video_dmi_table);
2157
2158         ret = acpi_bus_register_driver(&acpi_video_bus);
2159         if (ret)
2160                 goto leave;
2161
2162         /*
2163          * When the acpi_video_bus is loaded successfully, increase
2164          * the counter reference.
2165          */
2166         register_count = 1;
2167
2168 leave:
2169         mutex_unlock(&register_count_mutex);
2170         return ret;
2171 }
2172 EXPORT_SYMBOL(acpi_video_register);
2173
2174 void acpi_video_unregister(void)
2175 {
2176         mutex_lock(&register_count_mutex);
2177         if (register_count) {
2178                 acpi_bus_unregister_driver(&acpi_video_bus);
2179                 register_count = 0;
2180                 may_report_brightness_keys = false;
2181         }
2182         mutex_unlock(&register_count_mutex);
2183 }
2184 EXPORT_SYMBOL(acpi_video_unregister);
2185
2186 void acpi_video_register_backlight(void)
2187 {
2188         struct acpi_video_bus *video;
2189
2190         mutex_lock(&video_list_lock);
2191         list_for_each_entry(video, &video_bus_head, entry)
2192                 acpi_video_bus_register_backlight(video);
2193         mutex_unlock(&video_list_lock);
2194 }
2195 EXPORT_SYMBOL(acpi_video_register_backlight);
2196
2197 bool acpi_video_handles_brightness_key_presses(void)
2198 {
2199         return may_report_brightness_keys &&
2200                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2201 }
2202 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2203
2204 /*
2205  * This is kind of nasty. Hardware using Intel chipsets may require
2206  * the video opregion code to be run first in order to initialise
2207  * state before any ACPI video calls are made. To handle this we defer
2208  * registration of the video class until the opregion code has run.
2209  */
2210
2211 static int __init acpi_video_init(void)
2212 {
2213         /*
2214          * Let the module load even if ACPI is disabled (e.g. due to
2215          * a broken BIOS) so that i915.ko can still be loaded on such
2216          * old systems without an AcpiOpRegion.
2217          *
2218          * acpi_video_register() will report -ENODEV later as well due
2219          * to acpi_disabled when i915.ko tries to register itself afterwards.
2220          */
2221         if (acpi_disabled)
2222                 return 0;
2223
2224         if (intel_opregion_present())
2225                 return 0;
2226
2227         return acpi_video_register();
2228 }
2229
2230 static void __exit acpi_video_exit(void)
2231 {
2232         acpi_video_unregister();
2233 }
2234
2235 module_init(acpi_video_init);
2236 module_exit(acpi_video_exit);