drivers/acpi/video.c

   1 /*
   2  *  video.c - ACPI Video Driver
   3  *
   4  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   5  *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
   6  *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License along
  21  *  with this program; if not, write to the Free Software Foundation, Inc.,
  22  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/types.h>
  31 #include <linux/list.h>
  32 #include <linux/mutex.h>
  33 #include <linux/input.h>
  34 #include <linux/backlight.h>
  35 #include <linux/thermal.h>
  36 #include <linux/sort.h>
  37 #include <linux/pci.h>
  38 #include <linux/pci_ids.h>
  39 #include <linux/slab.h>
  40 #include <linux/dmi.h>
  41 #include <linux/suspend.h>
  42 #include <linux/acpi.h>
  43 #include <acpi/video.h>
  44 #include <asm/uaccess.h>
  45
  46 #include "internal.h"
  47
  48 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
  49 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  50 #define ACPI_VIDEO_NOTIFY_SWITCH        0x80
  51 #define ACPI_VIDEO_NOTIFY_PROBE         0x81
  52 #define ACPI_VIDEO_NOTIFY_CYCLE         0x82
  53 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT   0x83
  54 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT   0x84
  55
  56 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS      0x85
  57 #define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS        0x86
  58 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS        0x87
  59 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS       0x88
  60 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF           0x89
  61
  62 #define MAX_NAME_LEN    20
  63
  64 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  65 ACPI_MODULE_NAME("video");
  66
  67 MODULE_AUTHOR("Bruno Ducrot");
  68 MODULE_DESCRIPTION("ACPI Video Driver");
  69 MODULE_LICENSE("GPL");
  70
  71 static bool brightness_switch_enabled = 1;
  72 module_param(brightness_switch_enabled, bool, 0644);
  73
  74 /*
  75  * By default, we don't allow duplicate ACPI video bus devices
  76  * under the same VGA controller
  77  */
  78 static bool allow_duplicates;
  79 module_param(allow_duplicates, bool, 0644);
  80
  81 /*
  82  * For Windows 8 systems: used to decide if video module
  83  * should skip registering backlight interface of its own.
  84  */
  85 static int use_native_backlight_param = -1;
  86 module_param_named(use_native_backlight, use_native_backlight_param, int, 0444);
  87 static bool use_native_backlight_dmi = true;
  88
  89 static int register_count;
  90 static struct mutex video_list_lock;
  91 static struct list_head video_bus_head;
  92 static int acpi_video_bus_add(struct acpi_device *device);
  93 static int acpi_video_bus_remove(struct acpi_device *device);
  94 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  95
  96 static const struct acpi_device_id video_device_ids[] = {
  97         {ACPI_VIDEO_HID, 0},
  98         {"", 0},
  99 };
 100 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 101
 102 static struct acpi_driver acpi_video_bus = {
 103         .name = "video",
 104         .class = ACPI_VIDEO_CLASS,
 105         .ids = video_device_ids,
 106         .ops = {
 107                 .add = acpi_video_bus_add,
 108                 .remove = acpi_video_bus_remove,
 109                 .notify = acpi_video_bus_notify,
 110                 },
 111 };
 112
 113 struct acpi_video_bus_flags {
 114         u8 multihead:1;         /* can switch video heads */
 115         u8 rom:1;               /* can retrieve a video rom */
 116         u8 post:1;              /* can configure the head to */
 117         u8 reserved:5;
 118 };
 119
 120 struct acpi_video_bus_cap {
 121         u8 _DOS:1;              /* Enable/Disable output switching */
 122         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 123         u8 _ROM:1;              /* Get ROM Data */
 124         u8 _GPD:1;              /* Get POST Device */
 125         u8 _SPD:1;              /* Set POST Device */
 126         u8 _VPO:1;              /* Video POST Options */
 127         u8 reserved:2;
 128 };
 129
 130 struct acpi_video_device_attrib {
 131         u32 display_index:4;    /* A zero-based instance of the Display */
 132         u32 display_port_attachment:4;  /* This field differentiates the display type */
 133         u32 display_type:4;     /* Describe the specific type in use */
 134         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 135         u32 bios_can_detect:1;  /* BIOS can detect the device */
 136         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 137                                    the VGA device. */
 138         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 139         u32 reserved:10;        /* Must be 0 */
 140         u32 device_id_scheme:1; /* Device ID Scheme */
 141 };
 142
 143 struct acpi_video_enumerated_device {
 144         union {
 145                 u32 int_val;
 146                 struct acpi_video_device_attrib attrib;
 147         } value;
 148         struct acpi_video_device *bind_info;
 149 };
 150
 151 struct acpi_video_bus {
 152         struct acpi_device *device;
 153         bool backlight_registered;
 154         bool backlight_notifier_registered;
 155         u8 dos_setting;
 156         struct acpi_video_enumerated_device *attached_array;
 157         u8 attached_count;
 158         u8 child_count;
 159         struct acpi_video_bus_cap cap;
 160         struct acpi_video_bus_flags flags;
 161         struct list_head video_device_list;
 162         struct mutex device_list_lock;  /* protects video_device_list */
 163         struct list_head entry;
 164         struct input_dev *input;
 165         char phys[32];  /* for input device */
 166         struct notifier_block pm_nb;
 167         struct notifier_block backlight_nb;
 168 };
 169
 170 struct acpi_video_device_flags {
 171         u8 crt:1;
 172         u8 lcd:1;
 173         u8 tvout:1;
 174         u8 dvi:1;
 175         u8 bios:1;
 176         u8 unknown:1;
 177         u8 notify:1;
 178         u8 reserved:1;
 179 };
 180
 181 struct acpi_video_device_cap {
 182         u8 _ADR:1;              /* Return the unique ID */
 183         u8 _BCL:1;              /* Query list of brightness control levels supported */
 184         u8 _BCM:1;              /* Set the brightness level */
 185         u8 _BQC:1;              /* Get current brightness level */
 186         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 187         u8 _DDC:1;              /* Return the EDID for this device */
 188 };
 189
 190 struct acpi_video_brightness_flags {
 191         u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */
 192         u8 _BCL_reversed:1;             /* _BCL package is in a reversed order */
 193         u8 _BQC_use_index:1;            /* _BQC returns an index value */
 194 };
 195
 196 struct acpi_video_device_brightness {
 197         int curr;
 198         int count;
 199         int *levels;
 200         struct acpi_video_brightness_flags flags;
 201 };
 202
 203 struct acpi_video_device {
 204         unsigned long device_id;
 205         struct acpi_video_device_flags flags;
 206         struct acpi_video_device_cap cap;
 207         struct list_head entry;
 208         struct delayed_work switch_brightness_work;
 209         int switch_brightness_event;
 210         struct acpi_video_bus *video;
 211         struct acpi_device *dev;
 212         struct acpi_video_device_brightness *brightness;
 213         struct backlight_device *backlight;
 214         struct thermal_cooling_device *cooling_dev;
 215 };
 216
 217 static const char device_decode[][30] = {
 218         "motherboard VGA device",
 219         "PCI VGA device",
 220         "AGP VGA device",
 221         "UNKNOWN",
 222 };
 223
 224 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 225 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 226 static void acpi_video_device_bind(struct acpi_video_bus *video,
 227                                    struct acpi_video_device *device);
 228 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 229 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 230                         int level);
 231 static int acpi_video_device_lcd_get_level_current(
 232                         struct acpi_video_device *device,
 233                         unsigned long long *level, bool raw);
 234 static int acpi_video_get_next_level(struct acpi_video_device *device,
 235                                      u32 level_current, u32 event);
 236 static void acpi_video_switch_brightness(struct work_struct *work);
 237
 238 static bool acpi_video_use_native_backlight(void)
 239 {
 240         if (use_native_backlight_param != -1)
 241                 return use_native_backlight_param;
 242         else
 243                 return use_native_backlight_dmi;
 244 }
 245
 246 bool acpi_video_verify_backlight_support(void)
 247 {
 248         if (acpi_osi_is_win8() && acpi_video_use_native_backlight() &&
 249             backlight_device_registered(BACKLIGHT_RAW))
 250                 return false;
 251         return acpi_video_backlight_support();
 252 }
 253 EXPORT_SYMBOL_GPL(acpi_video_verify_backlight_support);
 254
 255 /* backlight device sysfs support */
 256 static int acpi_video_get_brightness(struct backlight_device *bd)
 257 {
 258         unsigned long long cur_level;
 259         int i;
 260         struct acpi_video_device *vd = bl_get_data(bd);
 261
 262         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 263                 return -EINVAL;
 264         for (i = 2; i < vd->brightness->count; i++) {
 265                 if (vd->brightness->levels[i] == cur_level)
 266                         /*
 267                          * The first two entries are special - see page 575
 268                          * of the ACPI spec 3.0
 269                          */
 270                         return i - 2;
 271         }
 272         return 0;
 273 }
 274
 275 static int acpi_video_set_brightness(struct backlight_device *bd)
 276 {
 277         int request_level = bd->props.brightness + 2;
 278         struct acpi_video_device *vd = bl_get_data(bd);
 279
 280         cancel_delayed_work(&vd->switch_brightness_work);
 281         return acpi_video_device_lcd_set_level(vd,
 282                                 vd->brightness->levels[request_level]);
 283 }
 284
 285 static const struct backlight_ops acpi_backlight_ops = {
 286         .get_brightness = acpi_video_get_brightness,
 287         .update_status  = acpi_video_set_brightness,
 288 };
 289
 290 /* thermal cooling device callbacks */
 291 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
 292                                long *state)
 293 {
 294         struct acpi_device *device = cooling_dev->devdata;
 295         struct acpi_video_device *video = acpi_driver_data(device);
 296
 297         *state = video->brightness->count - 3;
 298         return 0;
 299 }
 300
 301 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
 302                                long *state)
 303 {
 304         struct acpi_device *device = cooling_dev->devdata;
 305         struct acpi_video_device *video = acpi_driver_data(device);
 306         unsigned long long level;
 307         int offset;
 308
 309         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 310                 return -EINVAL;
 311         for (offset = 2; offset < video->brightness->count; offset++)
 312                 if (level == video->brightness->levels[offset]) {
 313                         *state = video->brightness->count - offset - 1;
 314                         return 0;
 315                 }
 316
 317         return -EINVAL;
 318 }
 319
 320 static int
 321 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 322 {
 323         struct acpi_device *device = cooling_dev->devdata;
 324         struct acpi_video_device *video = acpi_driver_data(device);
 325         int level;
 326
 327         if (state >= video->brightness->count - 2)
 328                 return -EINVAL;
 329
 330         state = video->brightness->count - state;
 331         level = video->brightness->levels[state - 1];
 332         return acpi_video_device_lcd_set_level(video, level);
 333 }
 334
 335 static const struct thermal_cooling_device_ops video_cooling_ops = {
 336         .get_max_state = video_get_max_state,
 337         .get_cur_state = video_get_cur_state,
 338         .set_cur_state = video_set_cur_state,
 339 };
 340
 341 /*
 342  * --------------------------------------------------------------------------
 343  *                             Video Management
 344  * --------------------------------------------------------------------------
 345  */
 346
 347 static int
 348 acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
 349                                    union acpi_object **levels)
 350 {
 351         int status;
 352         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 353         union acpi_object *obj;
 354
 355
 356         *levels = NULL;
 357
 358         status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
 359         if (!ACPI_SUCCESS(status))
 360                 return status;
 361         obj = (union acpi_object *)buffer.pointer;
 362         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 363                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 364                 status = -EFAULT;
 365                 goto err;
 366         }
 367
 368         *levels = obj;
 369
 370         return 0;
 371
 372 err:
 373         kfree(buffer.pointer);
 374
 375         return status;
 376 }
 377
 378 static int
 379 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 380 {
 381         int status;
 382         int state;
 383
 384         status = acpi_execute_simple_method(device->dev->handle,
 385                                             "_BCM", level);
 386         if (ACPI_FAILURE(status)) {
 387                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 388                 return -EIO;
 389         }
 390
 391         device->brightness->curr = level;
 392         for (state = 2; state < device->brightness->count; state++)
 393                 if (level == device->brightness->levels[state]) {
 394                         if (device->backlight)
 395                                 device->backlight->props.brightness = state - 2;
 396                         return 0;
 397                 }
 398
 399         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 400         return -EINVAL;
 401 }
 402
 403 /*
 404  * For some buggy _BQC methods, we need to add a constant value to
 405  * the _BQC return value to get the actual current brightness level
 406  */
 407
 408 static int bqc_offset_aml_bug_workaround;
 409 static int __init video_set_bqc_offset(const struct dmi_system_id *d)
 410 {
 411         bqc_offset_aml_bug_workaround = 9;
 412         return 0;
 413 }
 414
 415 static int __init video_disable_native_backlight(const struct dmi_system_id *d)
 416 {
 417         use_native_backlight_dmi = false;
 418         return 0;
 419 }
 420
 421 static struct dmi_system_id video_dmi_table[] __initdata = {
 422         /*
 423          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 424          */
 425         {
 426          .callback = video_set_bqc_offset,
 427          .ident = "Acer Aspire 5720",
 428          .matches = {
 429                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 430                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 431                 },
 432         },
 433         {
 434          .callback = video_set_bqc_offset,
 435          .ident = "Acer Aspire 5710Z",
 436          .matches = {
 437                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 438                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 439                 },
 440         },
 441         {
 442          .callback = video_set_bqc_offset,
 443          .ident = "eMachines E510",
 444          .matches = {
 445                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 446                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 447                 },
 448         },
 449         {
 450          .callback = video_set_bqc_offset,
 451          .ident = "Acer Aspire 5315",
 452          .matches = {
 453                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 454                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 455                 },
 456         },
 457         {
 458          .callback = video_set_bqc_offset,
 459          .ident = "Acer Aspire 7720",
 460          .matches = {
 461                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 462                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 463                 },
 464         },
 465
 466         /*
 467          * These models have a working acpi_video backlight control, and using
 468          * native backlight causes a regression where backlight does not work
 469          * when userspace is not handling brightness key events. Disable
 470          * native_backlight on these to fix this:
 471          * https://bugzilla.kernel.org/show_bug.cgi?id=81691
 472          */
 473         {
 474          .callback = video_disable_native_backlight,
 475          .ident = "ThinkPad T420",
 476          .matches = {
 477                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 478                 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
 479                 },
 480         },
 481         {
 482          .callback = video_disable_native_backlight,
 483          .ident = "ThinkPad T520",
 484          .matches = {
 485                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 486                 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
 487                 },
 488         },
 489         {
 490          .callback = video_disable_native_backlight,
 491          .ident = "ThinkPad X201s",
 492          .matches = {
 493                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 494                 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
 495                 },
 496         },
 497
 498         /* The native backlight controls do not work on some older machines */
 499         {
 500          /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
 501          .callback = video_disable_native_backlight,
 502          .ident = "HP ENVY 15 Notebook",
 503          .matches = {
 504                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 505                 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
 506                 },
 507         },
 508
 509         {
 510          .callback = video_disable_native_backlight,
 511          .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
 512          .matches = {
 513                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 514                 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
 515                 },
 516         },
 517         {
 518          .callback = video_disable_native_backlight,
 519          .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
 520          .matches = {
 521                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 522                 DMI_MATCH(DMI_PRODUCT_NAME, "370R4E/370R4V/370R5E/3570RE/370R5V"),
 523                 },
 524         },
 525         {}
 526 };
 527
 528 static unsigned long long
 529 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 530                               unsigned long long bqc_value)
 531 {
 532         unsigned long long level;
 533
 534         if (device->brightness->flags._BQC_use_index) {
 535                 /*
 536                  * _BQC returns an index that doesn't account for
 537                  * the first 2 items with special meaning, so we need
 538                  * to compensate for that by offsetting ourselves
 539                  */
 540                 if (device->brightness->flags._BCL_reversed)
 541                         bqc_value = device->brightness->count - 3 - bqc_value;
 542
 543                 level = device->brightness->levels[bqc_value + 2];
 544         } else {
 545                 level = bqc_value;
 546         }
 547
 548         level += bqc_offset_aml_bug_workaround;
 549
 550         return level;
 551 }
 552
 553 static int
 554 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 555                                         unsigned long long *level, bool raw)
 556 {
 557         acpi_status status = AE_OK;
 558         int i;
 559
 560         if (device->cap._BQC || device->cap._BCQ) {
 561                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 562
 563                 status = acpi_evaluate_integer(device->dev->handle, buf,
 564                                                 NULL, level);
 565                 if (ACPI_SUCCESS(status)) {
 566                         if (raw) {
 567                                 /*
 568                                  * Caller has indicated he wants the raw
 569                                  * value returned by _BQC, so don't furtherly
 570                                  * mess with the value.
 571                                  */
 572                                 return 0;
 573                         }
 574
 575                         *level = acpi_video_bqc_value_to_level(device, *level);
 576
 577                         for (i = 2; 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_WARNING((AE_INFO,
 587                                       "%s returned an invalid level",
 588                                       buf));
 589                         device->cap._BQC = device->cap._BCQ = 0;
 590                 } else {
 591                         /*
 592                          * Fixme:
 593                          * should we return an error or ignore this failure?
 594                          * dev->brightness->curr is a cached value which stores
 595                          * the correct current backlight level in most cases.
 596                          * ACPI video backlight still works w/ buggy _BQC.
 597                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 598                          */
 599                         ACPI_WARNING((AE_INFO, "Evaluating %s 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                 printk(KERN_ERR PREFIX "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 the power changes from AC to DC
 664  *              1.      The system BIOS should NOT automatically control the brightness
 665  *                      level of the LCD when the power changes from AC to DC.
 666  *  Return Value:
 667  *              -EINVAL wrong arg.
 668  */
 669
 670 static int
 671 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 672 {
 673         acpi_status status;
 674
 675         if (!video->cap._DOS)
 676                 return 0;
 677
 678         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 679                 return -EINVAL;
 680         video->dos_setting = (lcd_flag << 2) | bios_flag;
 681         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 682                                             (lcd_flag << 2) | bios_flag);
 683         if (ACPI_FAILURE(status))
 684                 return -EIO;
 685
 686         return 0;
 687 }
 688
 689 /*
 690  * Simple comparison function used to sort backlight levels.
 691  */
 692
 693 static int
 694 acpi_video_cmp_level(const void *a, const void *b)
 695 {
 696         return *(int *)a - *(int *)b;
 697 }
 698
 699 /*
 700  * Decides if _BQC/_BCQ for this system is usable
 701  *
 702  * We do this by changing the level first and then read out the current
 703  * brightness level, if the value does not match, find out if it is using
 704  * index. If not, clear the _BQC/_BCQ capability.
 705  */
 706 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 707                                 int max_level, int current_level)
 708 {
 709         struct acpi_video_device_brightness *br = device->brightness;
 710         int result;
 711         unsigned long long level;
 712         int test_level;
 713
 714         /* don't mess with existing known broken systems */
 715         if (bqc_offset_aml_bug_workaround)
 716                 return 0;
 717
 718         /*
 719          * Some systems always report current brightness level as maximum
 720          * through _BQC, we need to test another value for them.
 721          */
 722         test_level = current_level == max_level ? br->levels[3] : max_level;
 723
 724         result = acpi_video_device_lcd_set_level(device, test_level);
 725         if (result)
 726                 return result;
 727
 728         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 729         if (result)
 730                 return result;
 731
 732         if (level != test_level) {
 733                 /* buggy _BQC found, need to find out if it uses index */
 734                 if (level < br->count) {
 735                         if (br->flags._BCL_reversed)
 736                                 level = br->count - 3 - level;
 737                         if (br->levels[level + 2] == test_level)
 738                                 br->flags._BQC_use_index = 1;
 739                 }
 740
 741                 if (!br->flags._BQC_use_index)
 742                         device->cap._BQC = device->cap._BCQ = 0;
 743         }
 744
 745         return 0;
 746 }
 747
 748
 749 /*
 750  *  Arg:
 751  *      device  : video output device (LCD, CRT, ..)
 752  *
 753  *  Return Value:
 754  *      Maximum brightness level
 755  *
 756  *  Allocate and initialize device->brightness.
 757  */
 758
 759 static int
 760 acpi_video_init_brightness(struct acpi_video_device *device)
 761 {
 762         union acpi_object *obj = NULL;
 763         int i, max_level = 0, count = 0, level_ac_battery = 0;
 764         unsigned long long level, level_old;
 765         union acpi_object *o;
 766         struct acpi_video_device_brightness *br = NULL;
 767         int result = -EINVAL;
 768         u32 value;
 769
 770         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
 771                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 772                                                 "LCD brightness level\n"));
 773                 goto out;
 774         }
 775
 776         if (obj->package.count < 2)
 777                 goto out;
 778
 779         br = kzalloc(sizeof(*br), GFP_KERNEL);
 780         if (!br) {
 781                 printk(KERN_ERR "can't allocate memory\n");
 782                 result = -ENOMEM;
 783                 goto out;
 784         }
 785
 786         br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
 787                                 GFP_KERNEL);
 788         if (!br->levels) {
 789                 result = -ENOMEM;
 790                 goto out_free;
 791         }
 792
 793         for (i = 0; i < obj->package.count; i++) {
 794                 o = (union acpi_object *)&obj->package.elements[i];
 795                 if (o->type != ACPI_TYPE_INTEGER) {
 796                         printk(KERN_ERR PREFIX "Invalid data\n");
 797                         continue;
 798                 }
 799                 value = (u32) o->integer.value;
 800                 /* Skip duplicate entries */
 801                 if (count > 2 && br->levels[count - 1] == value)
 802                         continue;
 803
 804                 br->levels[count] = value;
 805
 806                 if (br->levels[count] > max_level)
 807                         max_level = br->levels[count];
 808                 count++;
 809         }
 810
 811         /*
 812          * some buggy BIOS don't export the levels
 813          * when machine is on AC/Battery in _BCL package.
 814          * In this case, the first two elements in _BCL packages
 815          * are also supported brightness levels that OS should take care of.
 816          */
 817         for (i = 2; i < count; i++) {
 818                 if (br->levels[i] == br->levels[0])
 819                         level_ac_battery++;
 820                 if (br->levels[i] == br->levels[1])
 821                         level_ac_battery++;
 822         }
 823
 824         if (level_ac_battery < 2) {
 825                 level_ac_battery = 2 - level_ac_battery;
 826                 br->flags._BCL_no_ac_battery_levels = 1;
 827                 for (i = (count - 1 + level_ac_battery); i >= 2; i--)
 828                         br->levels[i] = br->levels[i - level_ac_battery];
 829                 count += level_ac_battery;
 830         } else if (level_ac_battery > 2)
 831                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 832
 833         /* Check if the _BCL package is in a reversed order */
 834         if (max_level == br->levels[2]) {
 835                 br->flags._BCL_reversed = 1;
 836                 sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
 837                         acpi_video_cmp_level, NULL);
 838         } else if (max_level != br->levels[count - 1])
 839                 ACPI_ERROR((AE_INFO,
 840                             "Found unordered _BCL package"));
 841
 842         br->count = count;
 843         device->brightness = br;
 844
 845         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 846         br->curr = level = max_level;
 847
 848         if (!device->cap._BQC)
 849                 goto set_level;
 850
 851         result = acpi_video_device_lcd_get_level_current(device,
 852                                                          &level_old, true);
 853         if (result)
 854                 goto out_free_levels;
 855
 856         result = acpi_video_bqc_quirk(device, max_level, level_old);
 857         if (result)
 858                 goto out_free_levels;
 859         /*
 860          * cap._BQC may get cleared due to _BQC is found to be broken
 861          * in acpi_video_bqc_quirk, so check again here.
 862          */
 863         if (!device->cap._BQC)
 864                 goto set_level;
 865
 866         level = acpi_video_bqc_value_to_level(device, level_old);
 867         /*
 868          * On some buggy laptops, _BQC returns an uninitialized
 869          * value when invoked for the first time, i.e.
 870          * level_old is invalid (no matter whether it's a level
 871          * or an index). Set the backlight to max_level in this case.
 872          */
 873         for (i = 2; i < br->count; i++)
 874                 if (level == br->levels[i])
 875                         break;
 876         if (i == br->count || !level)
 877                 level = max_level;
 878
 879 set_level:
 880         result = acpi_video_device_lcd_set_level(device, level);
 881         if (result)
 882                 goto out_free_levels;
 883
 884         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 885                           "found %d brightness levels\n", count - 2));
 886         kfree(obj);
 887         return result;
 888
 889 out_free_levels:
 890         kfree(br->levels);
 891 out_free:
 892         kfree(br);
 893 out:
 894         device->brightness = NULL;
 895         kfree(obj);
 896         return result;
 897 }
 898
 899 /*
 900  *  Arg:
 901  *      device  : video output device (LCD, CRT, ..)
 902  *
 903  *  Return Value:
 904  *      None
 905  *
 906  *  Find out all required AML methods defined under the output
 907  *  device.
 908  */
 909
 910 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 911 {
 912         if (acpi_has_method(device->dev->handle, "_ADR"))
 913                 device->cap._ADR = 1;
 914         if (acpi_has_method(device->dev->handle, "_BCL"))
 915                 device->cap._BCL = 1;
 916         if (acpi_has_method(device->dev->handle, "_BCM"))
 917                 device->cap._BCM = 1;
 918         if (acpi_has_method(device->dev->handle, "_BQC")) {
 919                 device->cap._BQC = 1;
 920         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 921                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 922                 device->cap._BCQ = 1;
 923         }
 924
 925         if (acpi_has_method(device->dev->handle, "_DDC"))
 926                 device->cap._DDC = 1;
 927 }
 928
 929 /*
 930  *  Arg:
 931  *      device  : video output device (VGA)
 932  *
 933  *  Return Value:
 934  *      None
 935  *
 936  *  Find out all required AML methods defined under the video bus device.
 937  */
 938
 939 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 940 {
 941         if (acpi_has_method(video->device->handle, "_DOS"))
 942                 video->cap._DOS = 1;
 943         if (acpi_has_method(video->device->handle, "_DOD"))
 944                 video->cap._DOD = 1;
 945         if (acpi_has_method(video->device->handle, "_ROM"))
 946                 video->cap._ROM = 1;
 947         if (acpi_has_method(video->device->handle, "_GPD"))
 948                 video->cap._GPD = 1;
 949         if (acpi_has_method(video->device->handle, "_SPD"))
 950                 video->cap._SPD = 1;
 951         if (acpi_has_method(video->device->handle, "_VPO"))
 952                 video->cap._VPO = 1;
 953 }
 954
 955 /*
 956  * Check whether the video bus device has required AML method to
 957  * support the desired features
 958  */
 959
 960 static int acpi_video_bus_check(struct acpi_video_bus *video)
 961 {
 962         acpi_status status = -ENOENT;
 963         struct pci_dev *dev;
 964
 965         if (!video)
 966                 return -EINVAL;
 967
 968         dev = acpi_get_pci_dev(video->device->handle);
 969         if (!dev)
 970                 return -ENODEV;
 971         pci_dev_put(dev);
 972
 973         /*
 974          * Since there is no HID, CID and so on for VGA driver, we have
 975          * to check well known required nodes.
 976          */
 977
 978         /* Does this device support video switching? */
 979         if (video->cap._DOS || video->cap._DOD) {
 980                 if (!video->cap._DOS) {
 981                         printk(KERN_WARNING FW_BUG
 982                                 "ACPI(%s) defines _DOD but not _DOS\n",
 983                                 acpi_device_bid(video->device));
 984                 }
 985                 video->flags.multihead = 1;
 986                 status = 0;
 987         }
 988
 989         /* Does this device support retrieving a video ROM? */
 990         if (video->cap._ROM) {
 991                 video->flags.rom = 1;
 992                 status = 0;
 993         }
 994
 995         /* Does this device support configuring which video device to POST? */
 996         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
 997                 video->flags.post = 1;
 998                 status = 0;
 999         }
1000
1001         return status;
1002 }
1003
1004 /*
1005  * --------------------------------------------------------------------------
1006  *                               Driver Interface
1007  * --------------------------------------------------------------------------
1008  */
1009
1010 /* device interface */
1011 static struct acpi_video_device_attrib *
1012 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1013 {
1014         struct acpi_video_enumerated_device *ids;
1015         int i;
1016
1017         for (i = 0; i < video->attached_count; i++) {
1018                 ids = &video->attached_array[i];
1019                 if ((ids->value.int_val & 0xffff) == device_id)
1020                         return &ids->value.attrib;
1021         }
1022
1023         return NULL;
1024 }
1025
1026 static int
1027 acpi_video_get_device_type(struct acpi_video_bus *video,
1028                            unsigned long device_id)
1029 {
1030         struct acpi_video_enumerated_device *ids;
1031         int i;
1032
1033         for (i = 0; i < video->attached_count; i++) {
1034                 ids = &video->attached_array[i];
1035                 if ((ids->value.int_val & 0xffff) == device_id)
1036                         return ids->value.int_val;
1037         }
1038
1039         return 0;
1040 }
1041
1042 static int
1043 acpi_video_bus_get_one_device(struct acpi_device *device,
1044                               struct acpi_video_bus *video)
1045 {
1046         unsigned long long device_id;
1047         int status, device_type;
1048         struct acpi_video_device *data;
1049         struct acpi_video_device_attrib *attribute;
1050
1051         status =
1052             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1053         /* Some device omits _ADR, we skip them instead of fail */
1054         if (ACPI_FAILURE(status))
1055                 return 0;
1056
1057         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1058         if (!data)
1059                 return -ENOMEM;
1060
1061         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1062         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1063         device->driver_data = data;
1064
1065         data->device_id = device_id;
1066         data->video = video;
1067         data->dev = device;
1068         INIT_DELAYED_WORK(&data->switch_brightness_work,
1069                           acpi_video_switch_brightness);
1070
1071         attribute = acpi_video_get_device_attr(video, device_id);
1072
1073         if (attribute && attribute->device_id_scheme) {
1074                 switch (attribute->display_type) {
1075                 case ACPI_VIDEO_DISPLAY_CRT:
1076                         data->flags.crt = 1;
1077                         break;
1078                 case ACPI_VIDEO_DISPLAY_TV:
1079                         data->flags.tvout = 1;
1080                         break;
1081                 case ACPI_VIDEO_DISPLAY_DVI:
1082                         data->flags.dvi = 1;
1083                         break;
1084                 case ACPI_VIDEO_DISPLAY_LCD:
1085                         data->flags.lcd = 1;
1086                         break;
1087                 default:
1088                         data->flags.unknown = 1;
1089                         break;
1090                 }
1091                 if (attribute->bios_can_detect)
1092                         data->flags.bios = 1;
1093         } else {
1094                 /* Check for legacy IDs */
1095                 device_type = acpi_video_get_device_type(video, device_id);
1096                 /* Ignore bits 16 and 18-20 */
1097                 switch (device_type & 0xffe2ffff) {
1098                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1099                         data->flags.crt = 1;
1100                         break;
1101                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1102                         data->flags.lcd = 1;
1103                         break;
1104                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1105                         data->flags.tvout = 1;
1106                         break;
1107                 default:
1108                         data->flags.unknown = 1;
1109                 }
1110         }
1111
1112         acpi_video_device_bind(video, data);
1113         acpi_video_device_find_cap(data);
1114
1115         mutex_lock(&video->device_list_lock);
1116         list_add_tail(&data->entry, &video->video_device_list);
1117         mutex_unlock(&video->device_list_lock);
1118
1119         return status;
1120 }
1121
1122 /*
1123  *  Arg:
1124  *      video   : video bus device
1125  *
1126  *  Return:
1127  *      none
1128  *
1129  *  Enumerate the video device list of the video bus,
1130  *  bind the ids with the corresponding video devices
1131  *  under the video bus.
1132  */
1133
1134 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1135 {
1136         struct acpi_video_device *dev;
1137
1138         mutex_lock(&video->device_list_lock);
1139
1140         list_for_each_entry(dev, &video->video_device_list, entry)
1141                 acpi_video_device_bind(video, dev);
1142
1143         mutex_unlock(&video->device_list_lock);
1144 }
1145
1146 /*
1147  *  Arg:
1148  *      video   : video bus device
1149  *      device  : video output device under the video
1150  *              bus
1151  *
1152  *  Return:
1153  *      none
1154  *
1155  *  Bind the ids with the corresponding video devices
1156  *  under the video bus.
1157  */
1158
1159 static void
1160 acpi_video_device_bind(struct acpi_video_bus *video,
1161                        struct acpi_video_device *device)
1162 {
1163         struct acpi_video_enumerated_device *ids;
1164         int i;
1165
1166         for (i = 0; i < video->attached_count; i++) {
1167                 ids = &video->attached_array[i];
1168                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1169                         ids->bind_info = device;
1170                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1171                 }
1172         }
1173 }
1174
1175 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1176 {
1177         struct acpi_video_bus *video = device->video;
1178         int i;
1179
1180         /*
1181          * If we have a broken _DOD or we have more than 8 output devices
1182          * under the graphics controller node that we can't proper deal with
1183          * in the operation region code currently, no need to test.
1184          */
1185         if (!video->attached_count || video->child_count > 8)
1186                 return true;
1187
1188         for (i = 0; i < video->attached_count; i++) {
1189                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1190                     (device->device_id & 0xfff))
1191                         return true;
1192         }
1193
1194         return false;
1195 }
1196
1197 /*
1198  *  Arg:
1199  *      video   : video bus device
1200  *
1201  *  Return:
1202  *      < 0     : error
1203  *
1204  *  Call _DOD to enumerate all devices attached to display adapter
1205  *
1206  */
1207
1208 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1209 {
1210         int status;
1211         int count;
1212         int i;
1213         struct acpi_video_enumerated_device *active_list;
1214         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1215         union acpi_object *dod = NULL;
1216         union acpi_object *obj;
1217
1218         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1219         if (!ACPI_SUCCESS(status)) {
1220                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1221                 return status;
1222         }
1223
1224         dod = buffer.pointer;
1225         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1226                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1227                 status = -EFAULT;
1228                 goto out;
1229         }
1230
1231         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1232                           dod->package.count));
1233
1234         active_list = kcalloc(1 + dod->package.count,
1235                               sizeof(struct acpi_video_enumerated_device),
1236                               GFP_KERNEL);
1237         if (!active_list) {
1238                 status = -ENOMEM;
1239                 goto out;
1240         }
1241
1242         count = 0;
1243         for (i = 0; i < dod->package.count; i++) {
1244                 obj = &dod->package.elements[i];
1245
1246                 if (obj->type != ACPI_TYPE_INTEGER) {
1247                         printk(KERN_ERR PREFIX
1248                                 "Invalid _DOD data in element %d\n", i);
1249                         continue;
1250                 }
1251
1252                 active_list[count].value.int_val = obj->integer.value;
1253                 active_list[count].bind_info = NULL;
1254                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1255                                   (int)obj->integer.value));
1256                 count++;
1257         }
1258
1259         kfree(video->attached_array);
1260
1261         video->attached_array = active_list;
1262         video->attached_count = count;
1263
1264 out:
1265         kfree(buffer.pointer);
1266         return status;
1267 }
1268
1269 static int
1270 acpi_video_get_next_level(struct acpi_video_device *device,
1271                           u32 level_current, u32 event)
1272 {
1273         int min, max, min_above, max_below, i, l, delta = 255;
1274         max = max_below = 0;
1275         min = min_above = 255;
1276         /* Find closest level to level_current */
1277         for (i = 2; i < device->brightness->count; i++) {
1278                 l = device->brightness->levels[i];
1279                 if (abs(l - level_current) < abs(delta)) {
1280                         delta = l - level_current;
1281                         if (!delta)
1282                                 break;
1283                 }
1284         }
1285         /* Ajust level_current to closest available level */
1286         level_current += delta;
1287         for (i = 2; i < device->brightness->count; i++) {
1288                 l = device->brightness->levels[i];
1289                 if (l < min)
1290                         min = l;
1291                 if (l > max)
1292                         max = l;
1293                 if (l < min_above && l > level_current)
1294                         min_above = l;
1295                 if (l > max_below && l < level_current)
1296                         max_below = l;
1297         }
1298
1299         switch (event) {
1300         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1301                 return (level_current < max) ? min_above : min;
1302         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1303                 return (level_current < max) ? min_above : max;
1304         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1305                 return (level_current > min) ? max_below : min;
1306         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1307         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1308                 return 0;
1309         default:
1310                 return level_current;
1311         }
1312 }
1313
1314 static void
1315 acpi_video_switch_brightness(struct work_struct *work)
1316 {
1317         struct acpi_video_device *device = container_of(to_delayed_work(work),
1318                              struct acpi_video_device, switch_brightness_work);
1319         unsigned long long level_current, level_next;
1320         int event = device->switch_brightness_event;
1321         int result = -EINVAL;
1322
1323         /* no warning message if acpi_backlight=vendor or a quirk is used */
1324         if (!acpi_video_verify_backlight_support())
1325                 return;
1326
1327         if (!device->brightness)
1328                 goto out;
1329
1330         result = acpi_video_device_lcd_get_level_current(device,
1331                                                          &level_current,
1332                                                          false);
1333         if (result)
1334                 goto out;
1335
1336         level_next = acpi_video_get_next_level(device, level_current, event);
1337
1338         result = acpi_video_device_lcd_set_level(device, level_next);
1339
1340         if (!result)
1341                 backlight_force_update(device->backlight,
1342                                        BACKLIGHT_UPDATE_HOTKEY);
1343
1344 out:
1345         if (result)
1346                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1347 }
1348
1349 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1350                         void **edid)
1351 {
1352         struct acpi_video_bus *video;
1353         struct acpi_video_device *video_device;
1354         union acpi_object *buffer = NULL;
1355         acpi_status status;
1356         int i, length;
1357
1358         if (!device || !acpi_driver_data(device))
1359                 return -EINVAL;
1360
1361         video = acpi_driver_data(device);
1362
1363         for (i = 0; i < video->attached_count; i++) {
1364                 video_device = video->attached_array[i].bind_info;
1365                 length = 256;
1366
1367                 if (!video_device)
1368                         continue;
1369
1370                 if (!video_device->cap._DDC)
1371                         continue;
1372
1373                 if (type) {
1374                         switch (type) {
1375                         case ACPI_VIDEO_DISPLAY_CRT:
1376                                 if (!video_device->flags.crt)
1377                                         continue;
1378                                 break;
1379                         case ACPI_VIDEO_DISPLAY_TV:
1380                                 if (!video_device->flags.tvout)
1381                                         continue;
1382                                 break;
1383                         case ACPI_VIDEO_DISPLAY_DVI:
1384                                 if (!video_device->flags.dvi)
1385                                         continue;
1386                                 break;
1387                         case ACPI_VIDEO_DISPLAY_LCD:
1388                                 if (!video_device->flags.lcd)
1389                                         continue;
1390                                 break;
1391                         }
1392                 } else if (video_device->device_id != device_id) {
1393                         continue;
1394                 }
1395
1396                 status = acpi_video_device_EDID(video_device, &buffer, length);
1397
1398                 if (ACPI_FAILURE(status) || !buffer ||
1399                     buffer->type != ACPI_TYPE_BUFFER) {
1400                         length = 128;
1401                         status = acpi_video_device_EDID(video_device, &buffer,
1402                                                         length);
1403                         if (ACPI_FAILURE(status) || !buffer ||
1404                             buffer->type != ACPI_TYPE_BUFFER) {
1405                                 continue;
1406                         }
1407                 }
1408
1409                 *edid = buffer->buffer.pointer;
1410                 return length;
1411         }
1412
1413         return -ENODEV;
1414 }
1415 EXPORT_SYMBOL(acpi_video_get_edid);
1416
1417 static int
1418 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1419                            struct acpi_device *device)
1420 {
1421         int status = 0;
1422         struct acpi_device *dev;
1423
1424         /*
1425          * There are systems where video module known to work fine regardless
1426          * of broken _DOD and ignoring returned value here doesn't cause
1427          * any issues later.
1428          */
1429         acpi_video_device_enumerate(video);
1430
1431         list_for_each_entry(dev, &device->children, node) {
1432
1433                 status = acpi_video_bus_get_one_device(dev, video);
1434                 if (status) {
1435                         dev_err(&dev->dev, "Can't attach device\n");
1436                         break;
1437                 }
1438                 video->child_count++;
1439         }
1440         return status;
1441 }
1442
1443 /* acpi_video interface */
1444
1445 /*
1446  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1447  * preform any automatic brightness change on receiving a notification.
1448  */
1449 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1450 {
1451         return acpi_video_bus_DOS(video, 0,
1452                                   acpi_osi_is_win8() ? 1 : 0);
1453 }
1454
1455 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1456 {
1457         return acpi_video_bus_DOS(video, 0,
1458                                   acpi_osi_is_win8() ? 0 : 1);
1459 }
1460
1461 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1462 {
1463         struct acpi_video_bus *video = acpi_driver_data(device);
1464         struct input_dev *input;
1465         int keycode = 0;
1466
1467         if (!video || !video->input)
1468                 return;
1469
1470         input = video->input;
1471
1472         switch (event) {
1473         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1474                                          * most likely via hotkey. */
1475                 keycode = KEY_SWITCHVIDEOMODE;
1476                 break;
1477
1478         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1479                                          * connector. */
1480                 acpi_video_device_enumerate(video);
1481                 acpi_video_device_rebind(video);
1482                 keycode = KEY_SWITCHVIDEOMODE;
1483                 break;
1484
1485         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1486                 keycode = KEY_SWITCHVIDEOMODE;
1487                 break;
1488         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1489                 keycode = KEY_VIDEO_NEXT;
1490                 break;
1491         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1492                 keycode = KEY_VIDEO_PREV;
1493                 break;
1494
1495         default:
1496                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1497                                   "Unsupported event [0x%x]\n", event));
1498                 break;
1499         }
1500
1501         if (acpi_notifier_call_chain(device, event, 0))
1502                 /* Something vetoed the keypress. */
1503                 keycode = 0;
1504
1505         if (keycode) {
1506                 input_report_key(input, keycode, 1);
1507                 input_sync(input);
1508                 input_report_key(input, keycode, 0);
1509                 input_sync(input);
1510         }
1511
1512         return;
1513 }
1514
1515 static void brightness_switch_event(struct acpi_video_device *video_device,
1516                                     u32 event)
1517 {
1518         if (!brightness_switch_enabled)
1519                 return;
1520
1521         video_device->switch_brightness_event = event;
1522         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1523 }
1524
1525 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1526 {
1527         struct acpi_video_device *video_device = data;
1528         struct acpi_device *device = NULL;
1529         struct acpi_video_bus *bus;
1530         struct input_dev *input;
1531         int keycode = 0;
1532
1533         if (!video_device)
1534                 return;
1535
1536         device = video_device->dev;
1537         bus = video_device->video;
1538         input = bus->input;
1539
1540         switch (event) {
1541         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1542                 brightness_switch_event(video_device, event);
1543                 keycode = KEY_BRIGHTNESS_CYCLE;
1544                 break;
1545         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1546                 brightness_switch_event(video_device, event);
1547                 keycode = KEY_BRIGHTNESSUP;
1548                 break;
1549         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1550                 brightness_switch_event(video_device, event);
1551                 keycode = KEY_BRIGHTNESSDOWN;
1552                 break;
1553         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1554                 brightness_switch_event(video_device, event);
1555                 keycode = KEY_BRIGHTNESS_ZERO;
1556                 break;
1557         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1558                 brightness_switch_event(video_device, event);
1559                 keycode = KEY_DISPLAY_OFF;
1560                 break;
1561         default:
1562                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1563                                   "Unsupported event [0x%x]\n", event));
1564                 break;
1565         }
1566
1567         acpi_notifier_call_chain(device, event, 0);
1568
1569         if (keycode) {
1570                 input_report_key(input, keycode, 1);
1571                 input_sync(input);
1572                 input_report_key(input, keycode, 0);
1573                 input_sync(input);
1574         }
1575
1576         return;
1577 }
1578
1579 static int acpi_video_resume(struct notifier_block *nb,
1580                                 unsigned long val, void *ign)
1581 {
1582         struct acpi_video_bus *video;
1583         struct acpi_video_device *video_device;
1584         int i;
1585
1586         switch (val) {
1587         case PM_HIBERNATION_PREPARE:
1588         case PM_SUSPEND_PREPARE:
1589         case PM_RESTORE_PREPARE:
1590                 return NOTIFY_DONE;
1591         }
1592
1593         video = container_of(nb, struct acpi_video_bus, pm_nb);
1594
1595         dev_info(&video->device->dev, "Restoring backlight state\n");
1596
1597         for (i = 0; i < video->attached_count; i++) {
1598                 video_device = video->attached_array[i].bind_info;
1599                 if (video_device && video_device->backlight)
1600                         acpi_video_set_brightness(video_device->backlight);
1601         }
1602
1603         return NOTIFY_OK;
1604 }
1605
1606 static acpi_status
1607 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1608                         void **return_value)
1609 {
1610         struct acpi_device *device = context;
1611         struct acpi_device *sibling;
1612         int result;
1613
1614         if (handle == device->handle)
1615                 return AE_CTRL_TERMINATE;
1616
1617         result = acpi_bus_get_device(handle, &sibling);
1618         if (result)
1619                 return AE_OK;
1620
1621         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1622                         return AE_ALREADY_EXISTS;
1623
1624         return AE_OK;
1625 }
1626
1627 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1628 {
1629         struct backlight_properties props;
1630         struct pci_dev *pdev;
1631         acpi_handle acpi_parent;
1632         struct device *parent = NULL;
1633         int result;
1634         static int count;
1635         char *name;
1636
1637         /*
1638          * Do not create backlight device for video output
1639          * device that is not in the enumerated list.
1640          */
1641         if (!acpi_video_device_in_dod(device)) {
1642                 dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n");
1643                 return;
1644         }
1645
1646         result = acpi_video_init_brightness(device);
1647         if (result)
1648                 return;
1649         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1650         if (!name)
1651                 return;
1652         count++;
1653
1654         acpi_get_parent(device->dev->handle, &acpi_parent);
1655
1656         pdev = acpi_get_pci_dev(acpi_parent);
1657         if (pdev) {
1658                 parent = &pdev->dev;
1659                 pci_dev_put(pdev);
1660         }
1661
1662         memset(&props, 0, sizeof(struct backlight_properties));
1663         props.type = BACKLIGHT_FIRMWARE;
1664         props.max_brightness = device->brightness->count - 3;
1665         device->backlight = backlight_device_register(name,
1666                                                       parent,
1667                                                       device,
1668                                                       &acpi_backlight_ops,
1669                                                       &props);
1670         kfree(name);
1671         if (IS_ERR(device->backlight))
1672                 return;
1673
1674         /*
1675          * Save current brightness level in case we have to restore it
1676          * before acpi_video_device_lcd_set_level() is called next time.
1677          */
1678         device->backlight->props.brightness =
1679                         acpi_video_get_brightness(device->backlight);
1680
1681         device->cooling_dev = thermal_cooling_device_register("LCD",
1682                                 device->dev, &video_cooling_ops);
1683         if (IS_ERR(device->cooling_dev)) {
1684                 /*
1685                  * Set cooling_dev to NULL so we don't crash trying to free it.
1686                  * Also, why the hell we are returning early and not attempt to
1687                  * register video output if cooling device registration failed?
1688                  * -- dtor
1689                  */
1690                 device->cooling_dev = NULL;
1691                 return;
1692         }
1693
1694         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1695                  device->cooling_dev->id);
1696         result = sysfs_create_link(&device->dev->dev.kobj,
1697                         &device->cooling_dev->device.kobj,
1698                         "thermal_cooling");
1699         if (result)
1700                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1701         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1702                         &device->dev->dev.kobj, "device");
1703         if (result)
1704                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1705 }
1706
1707 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1708 {
1709         struct acpi_video_device *dev;
1710         union acpi_object *levels;
1711
1712         mutex_lock(&video->device_list_lock);
1713         list_for_each_entry(dev, &video->video_device_list, entry) {
1714                 if (!acpi_video_device_lcd_query_levels(dev, &levels))
1715                         kfree(levels);
1716         }
1717         mutex_unlock(&video->device_list_lock);
1718 }
1719
1720 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1721 {
1722         struct acpi_video_device *dev;
1723
1724         if (video->backlight_registered)
1725                 return 0;
1726
1727         acpi_video_run_bcl_for_osi(video);
1728
1729         if (!acpi_video_verify_backlight_support())
1730                 return 0;
1731
1732         mutex_lock(&video->device_list_lock);
1733         list_for_each_entry(dev, &video->video_device_list, entry)
1734                 acpi_video_dev_register_backlight(dev);
1735         mutex_unlock(&video->device_list_lock);
1736
1737         video->backlight_registered = true;
1738
1739         video->pm_nb.notifier_call = acpi_video_resume;
1740         video->pm_nb.priority = 0;
1741         return register_pm_notifier(&video->pm_nb);
1742 }
1743
1744 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1745 {
1746         if (device->backlight) {
1747                 backlight_device_unregister(device->backlight);
1748                 device->backlight = NULL;
1749         }
1750         if (device->brightness) {
1751                 kfree(device->brightness->levels);
1752                 kfree(device->brightness);
1753                 device->brightness = NULL;
1754         }
1755         if (device->cooling_dev) {
1756                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1757                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1758                 thermal_cooling_device_unregister(device->cooling_dev);
1759                 device->cooling_dev = NULL;
1760         }
1761 }
1762
1763 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1764 {
1765         struct acpi_video_device *dev;
1766         int error;
1767
1768         if (!video->backlight_registered)
1769                 return 0;
1770
1771         error = unregister_pm_notifier(&video->pm_nb);
1772
1773         mutex_lock(&video->device_list_lock);
1774         list_for_each_entry(dev, &video->video_device_list, entry)
1775                 acpi_video_dev_unregister_backlight(dev);
1776         mutex_unlock(&video->device_list_lock);
1777
1778         video->backlight_registered = false;
1779
1780         return error;
1781 }
1782
1783 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1784 {
1785         acpi_status status;
1786         struct acpi_device *adev = device->dev;
1787
1788         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1789                                              acpi_video_device_notify, device);
1790         if (ACPI_FAILURE(status))
1791                 dev_err(&adev->dev, "Error installing notify handler\n");
1792         else
1793                 device->flags.notify = 1;
1794 }
1795
1796 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1797 {
1798         struct input_dev *input;
1799         struct acpi_video_device *dev;
1800         int error;
1801
1802         video->input = input = input_allocate_device();
1803         if (!input) {
1804                 error = -ENOMEM;
1805                 goto out;
1806         }
1807
1808         error = acpi_video_bus_start_devices(video);
1809         if (error)
1810                 goto err_free_input;
1811
1812         snprintf(video->phys, sizeof(video->phys),
1813                         "%s/video/input0", acpi_device_hid(video->device));
1814
1815         input->name = acpi_device_name(video->device);
1816         input->phys = video->phys;
1817         input->id.bustype = BUS_HOST;
1818         input->id.product = 0x06;
1819         input->dev.parent = &video->device->dev;
1820         input->evbit[0] = BIT(EV_KEY);
1821         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1822         set_bit(KEY_VIDEO_NEXT, input->keybit);
1823         set_bit(KEY_VIDEO_PREV, input->keybit);
1824         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1825         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1826         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1827         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1828         set_bit(KEY_DISPLAY_OFF, input->keybit);
1829
1830         error = input_register_device(input);
1831         if (error)
1832                 goto err_stop_dev;
1833
1834         mutex_lock(&video->device_list_lock);
1835         list_for_each_entry(dev, &video->video_device_list, entry)
1836                 acpi_video_dev_add_notify_handler(dev);
1837         mutex_unlock(&video->device_list_lock);
1838
1839         return 0;
1840
1841 err_stop_dev:
1842         acpi_video_bus_stop_devices(video);
1843 err_free_input:
1844         input_free_device(input);
1845         video->input = NULL;
1846 out:
1847         return error;
1848 }
1849
1850 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1851 {
1852         if (dev->flags.notify) {
1853                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1854                                            acpi_video_device_notify);
1855                 dev->flags.notify = 0;
1856         }
1857 }
1858
1859 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1860 {
1861         struct acpi_video_device *dev;
1862
1863         mutex_lock(&video->device_list_lock);
1864         list_for_each_entry(dev, &video->video_device_list, entry)
1865                 acpi_video_dev_remove_notify_handler(dev);
1866         mutex_unlock(&video->device_list_lock);
1867
1868         acpi_video_bus_stop_devices(video);
1869         input_unregister_device(video->input);
1870         video->input = NULL;
1871 }
1872
1873 static int acpi_video_backlight_notify(struct notifier_block *nb,
1874                                         unsigned long val, void *bd)
1875 {
1876         struct backlight_device *backlight = bd;
1877         struct acpi_video_bus *video;
1878
1879         /* acpi_video_verify_backlight_support only cares about raw devices */
1880         if (backlight->props.type != BACKLIGHT_RAW)
1881                 return NOTIFY_DONE;
1882
1883         video = container_of(nb, struct acpi_video_bus, backlight_nb);
1884
1885         switch (val) {
1886         case BACKLIGHT_REGISTERED:
1887                 if (!acpi_video_verify_backlight_support())
1888                         acpi_video_bus_unregister_backlight(video);
1889                 break;
1890         case BACKLIGHT_UNREGISTERED:
1891                 acpi_video_bus_register_backlight(video);
1892                 break;
1893         }
1894
1895         return NOTIFY_OK;
1896 }
1897
1898 static int acpi_video_bus_add_backlight_notify_handler(
1899                                                 struct acpi_video_bus *video)
1900 {
1901         int error;
1902
1903         video->backlight_nb.notifier_call = acpi_video_backlight_notify;
1904         video->backlight_nb.priority = 0;
1905         error = backlight_register_notifier(&video->backlight_nb);
1906         if (error == 0)
1907                 video->backlight_notifier_registered = true;
1908
1909         return error;
1910 }
1911
1912 static int acpi_video_bus_remove_backlight_notify_handler(
1913                                                 struct acpi_video_bus *video)
1914 {
1915         if (!video->backlight_notifier_registered)
1916                 return 0;
1917
1918         video->backlight_notifier_registered = false;
1919
1920         return backlight_unregister_notifier(&video->backlight_nb);
1921 }
1922
1923 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1924 {
1925         struct acpi_video_device *dev, *next;
1926
1927         mutex_lock(&video->device_list_lock);
1928         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1929                 list_del(&dev->entry);
1930                 kfree(dev);
1931         }
1932         mutex_unlock(&video->device_list_lock);
1933
1934         return 0;
1935 }
1936
1937 static int instance;
1938
1939 static int acpi_video_bus_add(struct acpi_device *device)
1940 {
1941         struct acpi_video_bus *video;
1942         int error;
1943         acpi_status status;
1944
1945         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1946                                 device->parent->handle, 1,
1947                                 acpi_video_bus_match, NULL,
1948                                 device, NULL);
1949         if (status == AE_ALREADY_EXISTS) {
1950                 printk(KERN_WARNING FW_BUG
1951                         "Duplicate ACPI video bus devices for the"
1952                         " same VGA controller, please try module "
1953                         "parameter \"video.allow_duplicates=1\""
1954                         "if the current driver doesn't work.\n");
1955                 if (!allow_duplicates)
1956                         return -ENODEV;
1957         }
1958
1959         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1960         if (!video)
1961                 return -ENOMEM;
1962
1963         /* a hack to fix the duplicate name "VID" problem on T61 */
1964         if (!strcmp(device->pnp.bus_id, "VID")) {
1965                 if (instance)
1966                         device->pnp.bus_id[3] = '0' + instance;
1967                 instance++;
1968         }
1969         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1970         if (!strcmp(device->pnp.bus_id, "VGA")) {
1971                 if (instance)
1972                         device->pnp.bus_id[3] = '0' + instance;
1973                 instance++;
1974         }
1975
1976         video->device = device;
1977         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1978         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1979         device->driver_data = video;
1980
1981         acpi_video_bus_find_cap(video);
1982         error = acpi_video_bus_check(video);
1983         if (error)
1984                 goto err_free_video;
1985
1986         mutex_init(&video->device_list_lock);
1987         INIT_LIST_HEAD(&video->video_device_list);
1988
1989         error = acpi_video_bus_get_devices(video, device);
1990         if (error)
1991                 goto err_put_video;
1992
1993         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1994                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1995                video->flags.multihead ? "yes" : "no",
1996                video->flags.rom ? "yes" : "no",
1997                video->flags.post ? "yes" : "no");
1998         mutex_lock(&video_list_lock);
1999         list_add_tail(&video->entry, &video_bus_head);
2000         mutex_unlock(&video_list_lock);
2001
2002         acpi_video_bus_register_backlight(video);
2003         acpi_video_bus_add_notify_handler(video);
2004         acpi_video_bus_add_backlight_notify_handler(video);
2005
2006         return 0;
2007
2008 err_put_video:
2009         acpi_video_bus_put_devices(video);
2010         kfree(video->attached_array);
2011 err_free_video:
2012         kfree(video);
2013         device->driver_data = NULL;
2014
2015         return error;
2016 }
2017
2018 static int acpi_video_bus_remove(struct acpi_device *device)
2019 {
2020         struct acpi_video_bus *video = NULL;
2021
2022
2023         if (!device || !acpi_driver_data(device))
2024                 return -EINVAL;
2025
2026         video = acpi_driver_data(device);
2027
2028         acpi_video_bus_remove_backlight_notify_handler(video);
2029         acpi_video_bus_remove_notify_handler(video);
2030         acpi_video_bus_unregister_backlight(video);
2031         acpi_video_bus_put_devices(video);
2032
2033         mutex_lock(&video_list_lock);
2034         list_del(&video->entry);
2035         mutex_unlock(&video_list_lock);
2036
2037         kfree(video->attached_array);
2038         kfree(video);
2039
2040         return 0;
2041 }
2042
2043 static int __init is_i740(struct pci_dev *dev)
2044 {
2045         if (dev->device == 0x00D1)
2046                 return 1;
2047         if (dev->device == 0x7000)
2048                 return 1;
2049         return 0;
2050 }
2051
2052 static int __init intel_opregion_present(void)
2053 {
2054         int opregion = 0;
2055         struct pci_dev *dev = NULL;
2056         u32 address;
2057
2058         for_each_pci_dev(dev) {
2059                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2060                         continue;
2061                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2062                         continue;
2063                 /* We don't want to poke around undefined i740 registers */
2064                 if (is_i740(dev))
2065                         continue;
2066                 pci_read_config_dword(dev, 0xfc, &address);
2067                 if (!address)
2068                         continue;
2069                 opregion = 1;
2070         }
2071         return opregion;
2072 }
2073
2074 int acpi_video_register(void)
2075 {
2076         int result = 0;
2077         if (register_count) {
2078                 /*
2079                  * if the function of acpi_video_register is already called,
2080                  * don't register the acpi_vide_bus again and return no error.
2081                  */
2082                 return 0;
2083         }
2084
2085         mutex_init(&video_list_lock);
2086         INIT_LIST_HEAD(&video_bus_head);
2087
2088         result = acpi_bus_register_driver(&acpi_video_bus);
2089         if (result < 0)
2090                 return -ENODEV;
2091
2092         /*
2093          * When the acpi_video_bus is loaded successfully, increase
2094          * the counter reference.
2095          */
2096         register_count = 1;
2097
2098         return 0;
2099 }
2100 EXPORT_SYMBOL(acpi_video_register);
2101
2102 void acpi_video_unregister(void)
2103 {
2104         if (!register_count) {
2105                 /*
2106                  * If the acpi video bus is already unloaded, don't
2107                  * unload it again and return directly.
2108                  */
2109                 return;
2110         }
2111         acpi_bus_unregister_driver(&acpi_video_bus);
2112
2113         register_count = 0;
2114
2115         return;
2116 }
2117 EXPORT_SYMBOL(acpi_video_unregister);
2118
2119 void acpi_video_unregister_backlight(void)
2120 {
2121         struct acpi_video_bus *video;
2122
2123         if (!register_count)
2124                 return;
2125
2126         mutex_lock(&video_list_lock);
2127         list_for_each_entry(video, &video_bus_head, entry)
2128                 acpi_video_bus_unregister_backlight(video);
2129         mutex_unlock(&video_list_lock);
2130 }
2131 EXPORT_SYMBOL(acpi_video_unregister_backlight);
2132
2133 /*
2134  * This is kind of nasty. Hardware using Intel chipsets may require
2135  * the video opregion code to be run first in order to initialise
2136  * state before any ACPI video calls are made. To handle this we defer
2137  * registration of the video class until the opregion code has run.
2138  */
2139
2140 static int __init acpi_video_init(void)
2141 {
2142         dmi_check_system(video_dmi_table);
2143
2144         if (intel_opregion_present())
2145                 return 0;
2146
2147         return acpi_video_register();
2148 }
2149
2150 static void __exit acpi_video_exit(void)
2151 {
2152         acpi_video_unregister();
2153
2154         return;
2155 }
2156
2157 module_init(acpi_video_init);
2158 module_exit(acpi_video_exit);