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          /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
 527          .callback = video_disable_native_backlight,
 528          .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
 529          .matches = {
 530                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 531                 DMI_MATCH(DMI_PRODUCT_NAME, "3570R/370R/470R/450R/510R/4450RV"),
 532                 },
 533         },
 534         {
 535          /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
 536          .callback = video_disable_native_backlight,
 537          .ident = "SAMSUNG 730U3E/740U3E",
 538          .matches = {
 539                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 540                 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
 541                 },
 542         },
 543
 544         {
 545          /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
 546          .callback = video_disable_native_backlight,
 547          .ident = "Dell XPS15 L521X",
 548          .matches = {
 549                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 550                 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
 551                 },
 552         },
 553         {}
 554 };
 555
 556 static unsigned long long
 557 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 558                               unsigned long long bqc_value)
 559 {
 560         unsigned long long level;
 561
 562         if (device->brightness->flags._BQC_use_index) {
 563                 /*
 564                  * _BQC returns an index that doesn't account for
 565                  * the first 2 items with special meaning, so we need
 566                  * to compensate for that by offsetting ourselves
 567                  */
 568                 if (device->brightness->flags._BCL_reversed)
 569                         bqc_value = device->brightness->count - 3 - bqc_value;
 570
 571                 level = device->brightness->levels[bqc_value + 2];
 572         } else {
 573                 level = bqc_value;
 574         }
 575
 576         level += bqc_offset_aml_bug_workaround;
 577
 578         return level;
 579 }
 580
 581 static int
 582 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 583                                         unsigned long long *level, bool raw)
 584 {
 585         acpi_status status = AE_OK;
 586         int i;
 587
 588         if (device->cap._BQC || device->cap._BCQ) {
 589                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 590
 591                 status = acpi_evaluate_integer(device->dev->handle, buf,
 592                                                 NULL, level);
 593                 if (ACPI_SUCCESS(status)) {
 594                         if (raw) {
 595                                 /*
 596                                  * Caller has indicated he wants the raw
 597                                  * value returned by _BQC, so don't furtherly
 598                                  * mess with the value.
 599                                  */
 600                                 return 0;
 601                         }
 602
 603                         *level = acpi_video_bqc_value_to_level(device, *level);
 604
 605                         for (i = 2; i < device->brightness->count; i++)
 606                                 if (device->brightness->levels[i] == *level) {
 607                                         device->brightness->curr = *level;
 608                                         return 0;
 609                                 }
 610                         /*
 611                          * BQC returned an invalid level.
 612                          * Stop using it.
 613                          */
 614                         ACPI_WARNING((AE_INFO,
 615                                       "%s returned an invalid level",
 616                                       buf));
 617                         device->cap._BQC = device->cap._BCQ = 0;
 618                 } else {
 619                         /*
 620                          * Fixme:
 621                          * should we return an error or ignore this failure?
 622                          * dev->brightness->curr is a cached value which stores
 623                          * the correct current backlight level in most cases.
 624                          * ACPI video backlight still works w/ buggy _BQC.
 625                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 626                          */
 627                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 628                         device->cap._BQC = device->cap._BCQ = 0;
 629                 }
 630         }
 631
 632         *level = device->brightness->curr;
 633         return 0;
 634 }
 635
 636 static int
 637 acpi_video_device_EDID(struct acpi_video_device *device,
 638                        union acpi_object **edid, ssize_t length)
 639 {
 640         int status;
 641         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 642         union acpi_object *obj;
 643         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 644         struct acpi_object_list args = { 1, &arg0 };
 645
 646
 647         *edid = NULL;
 648
 649         if (!device)
 650                 return -ENODEV;
 651         if (length == 128)
 652                 arg0.integer.value = 1;
 653         else if (length == 256)
 654                 arg0.integer.value = 2;
 655         else
 656                 return -EINVAL;
 657
 658         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 659         if (ACPI_FAILURE(status))
 660                 return -ENODEV;
 661
 662         obj = buffer.pointer;
 663
 664         if (obj && obj->type == ACPI_TYPE_BUFFER)
 665                 *edid = obj;
 666         else {
 667                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 668                 status = -EFAULT;
 669                 kfree(obj);
 670         }
 671
 672         return status;
 673 }
 674
 675 /* bus */
 676
 677 /*
 678  *  Arg:
 679  *      video           : video bus device pointer
 680  *      bios_flag       :
 681  *              0.      The system BIOS should NOT automatically switch(toggle)
 682  *                      the active display output.
 683  *              1.      The system BIOS should automatically switch (toggle) the
 684  *                      active display output. No switch event.
 685  *              2.      The _DGS value should be locked.
 686  *              3.      The system BIOS should not automatically switch (toggle) the
 687  *                      active display output, but instead generate the display switch
 688  *                      event notify code.
 689  *      lcd_flag        :
 690  *              0.      The system BIOS should automatically control the brightness level
 691  *                      of the LCD when the power changes from AC to DC
 692  *              1.      The system BIOS should NOT automatically control the brightness
 693  *                      level of the LCD when the power changes from AC to DC.
 694  *  Return Value:
 695  *              -EINVAL wrong arg.
 696  */
 697
 698 static int
 699 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 700 {
 701         acpi_status status;
 702
 703         if (!video->cap._DOS)
 704                 return 0;
 705
 706         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 707                 return -EINVAL;
 708         video->dos_setting = (lcd_flag << 2) | bios_flag;
 709         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 710                                             (lcd_flag << 2) | bios_flag);
 711         if (ACPI_FAILURE(status))
 712                 return -EIO;
 713
 714         return 0;
 715 }
 716
 717 /*
 718  * Simple comparison function used to sort backlight levels.
 719  */
 720
 721 static int
 722 acpi_video_cmp_level(const void *a, const void *b)
 723 {
 724         return *(int *)a - *(int *)b;
 725 }
 726
 727 /*
 728  * Decides if _BQC/_BCQ for this system is usable
 729  *
 730  * We do this by changing the level first and then read out the current
 731  * brightness level, if the value does not match, find out if it is using
 732  * index. If not, clear the _BQC/_BCQ capability.
 733  */
 734 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 735                                 int max_level, int current_level)
 736 {
 737         struct acpi_video_device_brightness *br = device->brightness;
 738         int result;
 739         unsigned long long level;
 740         int test_level;
 741
 742         /* don't mess with existing known broken systems */
 743         if (bqc_offset_aml_bug_workaround)
 744                 return 0;
 745
 746         /*
 747          * Some systems always report current brightness level as maximum
 748          * through _BQC, we need to test another value for them.
 749          */
 750         test_level = current_level == max_level ? br->levels[3] : max_level;
 751
 752         result = acpi_video_device_lcd_set_level(device, test_level);
 753         if (result)
 754                 return result;
 755
 756         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 757         if (result)
 758                 return result;
 759
 760         if (level != test_level) {
 761                 /* buggy _BQC found, need to find out if it uses index */
 762                 if (level < br->count) {
 763                         if (br->flags._BCL_reversed)
 764                                 level = br->count - 3 - level;
 765                         if (br->levels[level + 2] == test_level)
 766                                 br->flags._BQC_use_index = 1;
 767                 }
 768
 769                 if (!br->flags._BQC_use_index)
 770                         device->cap._BQC = device->cap._BCQ = 0;
 771         }
 772
 773         return 0;
 774 }
 775
 776
 777 /*
 778  *  Arg:
 779  *      device  : video output device (LCD, CRT, ..)
 780  *
 781  *  Return Value:
 782  *      Maximum brightness level
 783  *
 784  *  Allocate and initialize device->brightness.
 785  */
 786
 787 static int
 788 acpi_video_init_brightness(struct acpi_video_device *device)
 789 {
 790         union acpi_object *obj = NULL;
 791         int i, max_level = 0, count = 0, level_ac_battery = 0;
 792         unsigned long long level, level_old;
 793         union acpi_object *o;
 794         struct acpi_video_device_brightness *br = NULL;
 795         int result = -EINVAL;
 796         u32 value;
 797
 798         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
 799                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 800                                                 "LCD brightness level\n"));
 801                 goto out;
 802         }
 803
 804         if (obj->package.count < 2)
 805                 goto out;
 806
 807         br = kzalloc(sizeof(*br), GFP_KERNEL);
 808         if (!br) {
 809                 printk(KERN_ERR "can't allocate memory\n");
 810                 result = -ENOMEM;
 811                 goto out;
 812         }
 813
 814         br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
 815                                 GFP_KERNEL);
 816         if (!br->levels) {
 817                 result = -ENOMEM;
 818                 goto out_free;
 819         }
 820
 821         for (i = 0; i < obj->package.count; i++) {
 822                 o = (union acpi_object *)&obj->package.elements[i];
 823                 if (o->type != ACPI_TYPE_INTEGER) {
 824                         printk(KERN_ERR PREFIX "Invalid data\n");
 825                         continue;
 826                 }
 827                 value = (u32) o->integer.value;
 828                 /* Skip duplicate entries */
 829                 if (count > 2 && br->levels[count - 1] == value)
 830                         continue;
 831
 832                 br->levels[count] = value;
 833
 834                 if (br->levels[count] > max_level)
 835                         max_level = br->levels[count];
 836                 count++;
 837         }
 838
 839         /*
 840          * some buggy BIOS don't export the levels
 841          * when machine is on AC/Battery in _BCL package.
 842          * In this case, the first two elements in _BCL packages
 843          * are also supported brightness levels that OS should take care of.
 844          */
 845         for (i = 2; i < count; i++) {
 846                 if (br->levels[i] == br->levels[0])
 847                         level_ac_battery++;
 848                 if (br->levels[i] == br->levels[1])
 849                         level_ac_battery++;
 850         }
 851
 852         if (level_ac_battery < 2) {
 853                 level_ac_battery = 2 - level_ac_battery;
 854                 br->flags._BCL_no_ac_battery_levels = 1;
 855                 for (i = (count - 1 + level_ac_battery); i >= 2; i--)
 856                         br->levels[i] = br->levels[i - level_ac_battery];
 857                 count += level_ac_battery;
 858         } else if (level_ac_battery > 2)
 859                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 860
 861         /* Check if the _BCL package is in a reversed order */
 862         if (max_level == br->levels[2]) {
 863                 br->flags._BCL_reversed = 1;
 864                 sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
 865                         acpi_video_cmp_level, NULL);
 866         } else if (max_level != br->levels[count - 1])
 867                 ACPI_ERROR((AE_INFO,
 868                             "Found unordered _BCL package"));
 869
 870         br->count = count;
 871         device->brightness = br;
 872
 873         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 874         br->curr = level = max_level;
 875
 876         if (!device->cap._BQC)
 877                 goto set_level;
 878
 879         result = acpi_video_device_lcd_get_level_current(device,
 880                                                          &level_old, true);
 881         if (result)
 882                 goto out_free_levels;
 883
 884         result = acpi_video_bqc_quirk(device, max_level, level_old);
 885         if (result)
 886                 goto out_free_levels;
 887         /*
 888          * cap._BQC may get cleared due to _BQC is found to be broken
 889          * in acpi_video_bqc_quirk, so check again here.
 890          */
 891         if (!device->cap._BQC)
 892                 goto set_level;
 893
 894         level = acpi_video_bqc_value_to_level(device, level_old);
 895         /*
 896          * On some buggy laptops, _BQC returns an uninitialized
 897          * value when invoked for the first time, i.e.
 898          * level_old is invalid (no matter whether it's a level
 899          * or an index). Set the backlight to max_level in this case.
 900          */
 901         for (i = 2; i < br->count; i++)
 902                 if (level == br->levels[i])
 903                         break;
 904         if (i == br->count || !level)
 905                 level = max_level;
 906
 907 set_level:
 908         result = acpi_video_device_lcd_set_level(device, level);
 909         if (result)
 910                 goto out_free_levels;
 911
 912         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 913                           "found %d brightness levels\n", count - 2));
 914         kfree(obj);
 915         return result;
 916
 917 out_free_levels:
 918         kfree(br->levels);
 919 out_free:
 920         kfree(br);
 921 out:
 922         device->brightness = NULL;
 923         kfree(obj);
 924         return result;
 925 }
 926
 927 /*
 928  *  Arg:
 929  *      device  : video output device (LCD, CRT, ..)
 930  *
 931  *  Return Value:
 932  *      None
 933  *
 934  *  Find out all required AML methods defined under the output
 935  *  device.
 936  */
 937
 938 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 939 {
 940         if (acpi_has_method(device->dev->handle, "_ADR"))
 941                 device->cap._ADR = 1;
 942         if (acpi_has_method(device->dev->handle, "_BCL"))
 943                 device->cap._BCL = 1;
 944         if (acpi_has_method(device->dev->handle, "_BCM"))
 945                 device->cap._BCM = 1;
 946         if (acpi_has_method(device->dev->handle, "_BQC")) {
 947                 device->cap._BQC = 1;
 948         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 949                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 950                 device->cap._BCQ = 1;
 951         }
 952
 953         if (acpi_has_method(device->dev->handle, "_DDC"))
 954                 device->cap._DDC = 1;
 955 }
 956
 957 /*
 958  *  Arg:
 959  *      device  : video output device (VGA)
 960  *
 961  *  Return Value:
 962  *      None
 963  *
 964  *  Find out all required AML methods defined under the video bus device.
 965  */
 966
 967 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 968 {
 969         if (acpi_has_method(video->device->handle, "_DOS"))
 970                 video->cap._DOS = 1;
 971         if (acpi_has_method(video->device->handle, "_DOD"))
 972                 video->cap._DOD = 1;
 973         if (acpi_has_method(video->device->handle, "_ROM"))
 974                 video->cap._ROM = 1;
 975         if (acpi_has_method(video->device->handle, "_GPD"))
 976                 video->cap._GPD = 1;
 977         if (acpi_has_method(video->device->handle, "_SPD"))
 978                 video->cap._SPD = 1;
 979         if (acpi_has_method(video->device->handle, "_VPO"))
 980                 video->cap._VPO = 1;
 981 }
 982
 983 /*
 984  * Check whether the video bus device has required AML method to
 985  * support the desired features
 986  */
 987
 988 static int acpi_video_bus_check(struct acpi_video_bus *video)
 989 {
 990         acpi_status status = -ENOENT;
 991         struct pci_dev *dev;
 992
 993         if (!video)
 994                 return -EINVAL;
 995
 996         dev = acpi_get_pci_dev(video->device->handle);
 997         if (!dev)
 998                 return -ENODEV;
 999         pci_dev_put(dev);
1000
1001         /*
1002          * Since there is no HID, CID and so on for VGA driver, we have
1003          * to check well known required nodes.
1004          */
1005
1006         /* Does this device support video switching? */
1007         if (video->cap._DOS || video->cap._DOD) {
1008                 if (!video->cap._DOS) {
1009                         printk(KERN_WARNING FW_BUG
1010                                 "ACPI(%s) defines _DOD but not _DOS\n",
1011                                 acpi_device_bid(video->device));
1012                 }
1013                 video->flags.multihead = 1;
1014                 status = 0;
1015         }
1016
1017         /* Does this device support retrieving a video ROM? */
1018         if (video->cap._ROM) {
1019                 video->flags.rom = 1;
1020                 status = 0;
1021         }
1022
1023         /* Does this device support configuring which video device to POST? */
1024         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1025                 video->flags.post = 1;
1026                 status = 0;
1027         }
1028
1029         return status;
1030 }
1031
1032 /*
1033  * --------------------------------------------------------------------------
1034  *                               Driver Interface
1035  * --------------------------------------------------------------------------
1036  */
1037
1038 /* device interface */
1039 static struct acpi_video_device_attrib *
1040 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1041 {
1042         struct acpi_video_enumerated_device *ids;
1043         int i;
1044
1045         for (i = 0; i < video->attached_count; i++) {
1046                 ids = &video->attached_array[i];
1047                 if ((ids->value.int_val & 0xffff) == device_id)
1048                         return &ids->value.attrib;
1049         }
1050
1051         return NULL;
1052 }
1053
1054 static int
1055 acpi_video_get_device_type(struct acpi_video_bus *video,
1056                            unsigned long device_id)
1057 {
1058         struct acpi_video_enumerated_device *ids;
1059         int i;
1060
1061         for (i = 0; i < video->attached_count; i++) {
1062                 ids = &video->attached_array[i];
1063                 if ((ids->value.int_val & 0xffff) == device_id)
1064                         return ids->value.int_val;
1065         }
1066
1067         return 0;
1068 }
1069
1070 static int
1071 acpi_video_bus_get_one_device(struct acpi_device *device,
1072                               struct acpi_video_bus *video)
1073 {
1074         unsigned long long device_id;
1075         int status, device_type;
1076         struct acpi_video_device *data;
1077         struct acpi_video_device_attrib *attribute;
1078
1079         status =
1080             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1081         /* Some device omits _ADR, we skip them instead of fail */
1082         if (ACPI_FAILURE(status))
1083                 return 0;
1084
1085         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1086         if (!data)
1087                 return -ENOMEM;
1088
1089         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1090         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1091         device->driver_data = data;
1092
1093         data->device_id = device_id;
1094         data->video = video;
1095         data->dev = device;
1096         INIT_DELAYED_WORK(&data->switch_brightness_work,
1097                           acpi_video_switch_brightness);
1098
1099         attribute = acpi_video_get_device_attr(video, device_id);
1100
1101         if (attribute && attribute->device_id_scheme) {
1102                 switch (attribute->display_type) {
1103                 case ACPI_VIDEO_DISPLAY_CRT:
1104                         data->flags.crt = 1;
1105                         break;
1106                 case ACPI_VIDEO_DISPLAY_TV:
1107                         data->flags.tvout = 1;
1108                         break;
1109                 case ACPI_VIDEO_DISPLAY_DVI:
1110                         data->flags.dvi = 1;
1111                         break;
1112                 case ACPI_VIDEO_DISPLAY_LCD:
1113                         data->flags.lcd = 1;
1114                         break;
1115                 default:
1116                         data->flags.unknown = 1;
1117                         break;
1118                 }
1119                 if (attribute->bios_can_detect)
1120                         data->flags.bios = 1;
1121         } else {
1122                 /* Check for legacy IDs */
1123                 device_type = acpi_video_get_device_type(video, device_id);
1124                 /* Ignore bits 16 and 18-20 */
1125                 switch (device_type & 0xffe2ffff) {
1126                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1127                         data->flags.crt = 1;
1128                         break;
1129                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1130                         data->flags.lcd = 1;
1131                         break;
1132                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1133                         data->flags.tvout = 1;
1134                         break;
1135                 default:
1136                         data->flags.unknown = 1;
1137                 }
1138         }
1139
1140         acpi_video_device_bind(video, data);
1141         acpi_video_device_find_cap(data);
1142
1143         mutex_lock(&video->device_list_lock);
1144         list_add_tail(&data->entry, &video->video_device_list);
1145         mutex_unlock(&video->device_list_lock);
1146
1147         return status;
1148 }
1149
1150 /*
1151  *  Arg:
1152  *      video   : video bus device
1153  *
1154  *  Return:
1155  *      none
1156  *
1157  *  Enumerate the video device list of the video bus,
1158  *  bind the ids with the corresponding video devices
1159  *  under the video bus.
1160  */
1161
1162 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1163 {
1164         struct acpi_video_device *dev;
1165
1166         mutex_lock(&video->device_list_lock);
1167
1168         list_for_each_entry(dev, &video->video_device_list, entry)
1169                 acpi_video_device_bind(video, dev);
1170
1171         mutex_unlock(&video->device_list_lock);
1172 }
1173
1174 /*
1175  *  Arg:
1176  *      video   : video bus device
1177  *      device  : video output device under the video
1178  *              bus
1179  *
1180  *  Return:
1181  *      none
1182  *
1183  *  Bind the ids with the corresponding video devices
1184  *  under the video bus.
1185  */
1186
1187 static void
1188 acpi_video_device_bind(struct acpi_video_bus *video,
1189                        struct acpi_video_device *device)
1190 {
1191         struct acpi_video_enumerated_device *ids;
1192         int i;
1193
1194         for (i = 0; i < video->attached_count; i++) {
1195                 ids = &video->attached_array[i];
1196                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1197                         ids->bind_info = device;
1198                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1199                 }
1200         }
1201 }
1202
1203 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1204 {
1205         struct acpi_video_bus *video = device->video;
1206         int i;
1207
1208         /*
1209          * If we have a broken _DOD or we have more than 8 output devices
1210          * under the graphics controller node that we can't proper deal with
1211          * in the operation region code currently, no need to test.
1212          */
1213         if (!video->attached_count || video->child_count > 8)
1214                 return true;
1215
1216         for (i = 0; i < video->attached_count; i++) {
1217                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1218                     (device->device_id & 0xfff))
1219                         return true;
1220         }
1221
1222         return false;
1223 }
1224
1225 /*
1226  *  Arg:
1227  *      video   : video bus device
1228  *
1229  *  Return:
1230  *      < 0     : error
1231  *
1232  *  Call _DOD to enumerate all devices attached to display adapter
1233  *
1234  */
1235
1236 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1237 {
1238         int status;
1239         int count;
1240         int i;
1241         struct acpi_video_enumerated_device *active_list;
1242         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1243         union acpi_object *dod = NULL;
1244         union acpi_object *obj;
1245
1246         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1247         if (!ACPI_SUCCESS(status)) {
1248                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1249                 return status;
1250         }
1251
1252         dod = buffer.pointer;
1253         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1254                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1255                 status = -EFAULT;
1256                 goto out;
1257         }
1258
1259         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1260                           dod->package.count));
1261
1262         active_list = kcalloc(1 + dod->package.count,
1263                               sizeof(struct acpi_video_enumerated_device),
1264                               GFP_KERNEL);
1265         if (!active_list) {
1266                 status = -ENOMEM;
1267                 goto out;
1268         }
1269
1270         count = 0;
1271         for (i = 0; i < dod->package.count; i++) {
1272                 obj = &dod->package.elements[i];
1273
1274                 if (obj->type != ACPI_TYPE_INTEGER) {
1275                         printk(KERN_ERR PREFIX
1276                                 "Invalid _DOD data in element %d\n", i);
1277                         continue;
1278                 }
1279
1280                 active_list[count].value.int_val = obj->integer.value;
1281                 active_list[count].bind_info = NULL;
1282                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1283                                   (int)obj->integer.value));
1284                 count++;
1285         }
1286
1287         kfree(video->attached_array);
1288
1289         video->attached_array = active_list;
1290         video->attached_count = count;
1291
1292 out:
1293         kfree(buffer.pointer);
1294         return status;
1295 }
1296
1297 static int
1298 acpi_video_get_next_level(struct acpi_video_device *device,
1299                           u32 level_current, u32 event)
1300 {
1301         int min, max, min_above, max_below, i, l, delta = 255;
1302         max = max_below = 0;
1303         min = min_above = 255;
1304         /* Find closest level to level_current */
1305         for (i = 2; i < device->brightness->count; i++) {
1306                 l = device->brightness->levels[i];
1307                 if (abs(l - level_current) < abs(delta)) {
1308                         delta = l - level_current;
1309                         if (!delta)
1310                                 break;
1311                 }
1312         }
1313         /* Ajust level_current to closest available level */
1314         level_current += delta;
1315         for (i = 2; i < device->brightness->count; i++) {
1316                 l = device->brightness->levels[i];
1317                 if (l < min)
1318                         min = l;
1319                 if (l > max)
1320                         max = l;
1321                 if (l < min_above && l > level_current)
1322                         min_above = l;
1323                 if (l > max_below && l < level_current)
1324                         max_below = l;
1325         }
1326
1327         switch (event) {
1328         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1329                 return (level_current < max) ? min_above : min;
1330         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1331                 return (level_current < max) ? min_above : max;
1332         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1333                 return (level_current > min) ? max_below : min;
1334         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1335         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1336                 return 0;
1337         default:
1338                 return level_current;
1339         }
1340 }
1341
1342 static void
1343 acpi_video_switch_brightness(struct work_struct *work)
1344 {
1345         struct acpi_video_device *device = container_of(to_delayed_work(work),
1346                              struct acpi_video_device, switch_brightness_work);
1347         unsigned long long level_current, level_next;
1348         int event = device->switch_brightness_event;
1349         int result = -EINVAL;
1350
1351         /* no warning message if acpi_backlight=vendor or a quirk is used */
1352         if (!acpi_video_verify_backlight_support())
1353                 return;
1354
1355         if (!device->brightness)
1356                 goto out;
1357
1358         result = acpi_video_device_lcd_get_level_current(device,
1359                                                          &level_current,
1360                                                          false);
1361         if (result)
1362                 goto out;
1363
1364         level_next = acpi_video_get_next_level(device, level_current, event);
1365
1366         result = acpi_video_device_lcd_set_level(device, level_next);
1367
1368         if (!result)
1369                 backlight_force_update(device->backlight,
1370                                        BACKLIGHT_UPDATE_HOTKEY);
1371
1372 out:
1373         if (result)
1374                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1375 }
1376
1377 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1378                         void **edid)
1379 {
1380         struct acpi_video_bus *video;
1381         struct acpi_video_device *video_device;
1382         union acpi_object *buffer = NULL;
1383         acpi_status status;
1384         int i, length;
1385
1386         if (!device || !acpi_driver_data(device))
1387                 return -EINVAL;
1388
1389         video = acpi_driver_data(device);
1390
1391         for (i = 0; i < video->attached_count; i++) {
1392                 video_device = video->attached_array[i].bind_info;
1393                 length = 256;
1394
1395                 if (!video_device)
1396                         continue;
1397
1398                 if (!video_device->cap._DDC)
1399                         continue;
1400
1401                 if (type) {
1402                         switch (type) {
1403                         case ACPI_VIDEO_DISPLAY_CRT:
1404                                 if (!video_device->flags.crt)
1405                                         continue;
1406                                 break;
1407                         case ACPI_VIDEO_DISPLAY_TV:
1408                                 if (!video_device->flags.tvout)
1409                                         continue;
1410                                 break;
1411                         case ACPI_VIDEO_DISPLAY_DVI:
1412                                 if (!video_device->flags.dvi)
1413                                         continue;
1414                                 break;
1415                         case ACPI_VIDEO_DISPLAY_LCD:
1416                                 if (!video_device->flags.lcd)
1417                                         continue;
1418                                 break;
1419                         }
1420                 } else if (video_device->device_id != device_id) {
1421                         continue;
1422                 }
1423
1424                 status = acpi_video_device_EDID(video_device, &buffer, length);
1425
1426                 if (ACPI_FAILURE(status) || !buffer ||
1427                     buffer->type != ACPI_TYPE_BUFFER) {
1428                         length = 128;
1429                         status = acpi_video_device_EDID(video_device, &buffer,
1430                                                         length);
1431                         if (ACPI_FAILURE(status) || !buffer ||
1432                             buffer->type != ACPI_TYPE_BUFFER) {
1433                                 continue;
1434                         }
1435                 }
1436
1437                 *edid = buffer->buffer.pointer;
1438                 return length;
1439         }
1440
1441         return -ENODEV;
1442 }
1443 EXPORT_SYMBOL(acpi_video_get_edid);
1444
1445 static int
1446 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1447                            struct acpi_device *device)
1448 {
1449         int status = 0;
1450         struct acpi_device *dev;
1451
1452         /*
1453          * There are systems where video module known to work fine regardless
1454          * of broken _DOD and ignoring returned value here doesn't cause
1455          * any issues later.
1456          */
1457         acpi_video_device_enumerate(video);
1458
1459         list_for_each_entry(dev, &device->children, node) {
1460
1461                 status = acpi_video_bus_get_one_device(dev, video);
1462                 if (status) {
1463                         dev_err(&dev->dev, "Can't attach device\n");
1464                         break;
1465                 }
1466                 video->child_count++;
1467         }
1468         return status;
1469 }
1470
1471 /* acpi_video interface */
1472
1473 /*
1474  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1475  * preform any automatic brightness change on receiving a notification.
1476  */
1477 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1478 {
1479         return acpi_video_bus_DOS(video, 0,
1480                                   acpi_osi_is_win8() ? 1 : 0);
1481 }
1482
1483 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1484 {
1485         return acpi_video_bus_DOS(video, 0,
1486                                   acpi_osi_is_win8() ? 0 : 1);
1487 }
1488
1489 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1490 {
1491         struct acpi_video_bus *video = acpi_driver_data(device);
1492         struct input_dev *input;
1493         int keycode = 0;
1494
1495         if (!video || !video->input)
1496                 return;
1497
1498         input = video->input;
1499
1500         switch (event) {
1501         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1502                                          * most likely via hotkey. */
1503                 keycode = KEY_SWITCHVIDEOMODE;
1504                 break;
1505
1506         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1507                                          * connector. */
1508                 acpi_video_device_enumerate(video);
1509                 acpi_video_device_rebind(video);
1510                 keycode = KEY_SWITCHVIDEOMODE;
1511                 break;
1512
1513         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1514                 keycode = KEY_SWITCHVIDEOMODE;
1515                 break;
1516         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1517                 keycode = KEY_VIDEO_NEXT;
1518                 break;
1519         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1520                 keycode = KEY_VIDEO_PREV;
1521                 break;
1522
1523         default:
1524                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1525                                   "Unsupported event [0x%x]\n", event));
1526                 break;
1527         }
1528
1529         if (acpi_notifier_call_chain(device, event, 0))
1530                 /* Something vetoed the keypress. */
1531                 keycode = 0;
1532
1533         if (keycode) {
1534                 input_report_key(input, keycode, 1);
1535                 input_sync(input);
1536                 input_report_key(input, keycode, 0);
1537                 input_sync(input);
1538         }
1539
1540         return;
1541 }
1542
1543 static void brightness_switch_event(struct acpi_video_device *video_device,
1544                                     u32 event)
1545 {
1546         if (!brightness_switch_enabled)
1547                 return;
1548
1549         video_device->switch_brightness_event = event;
1550         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1551 }
1552
1553 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1554 {
1555         struct acpi_video_device *video_device = data;
1556         struct acpi_device *device = NULL;
1557         struct acpi_video_bus *bus;
1558         struct input_dev *input;
1559         int keycode = 0;
1560
1561         if (!video_device)
1562                 return;
1563
1564         device = video_device->dev;
1565         bus = video_device->video;
1566         input = bus->input;
1567
1568         switch (event) {
1569         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1570                 brightness_switch_event(video_device, event);
1571                 keycode = KEY_BRIGHTNESS_CYCLE;
1572                 break;
1573         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1574                 brightness_switch_event(video_device, event);
1575                 keycode = KEY_BRIGHTNESSUP;
1576                 break;
1577         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1578                 brightness_switch_event(video_device, event);
1579                 keycode = KEY_BRIGHTNESSDOWN;
1580                 break;
1581         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1582                 brightness_switch_event(video_device, event);
1583                 keycode = KEY_BRIGHTNESS_ZERO;
1584                 break;
1585         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1586                 brightness_switch_event(video_device, event);
1587                 keycode = KEY_DISPLAY_OFF;
1588                 break;
1589         default:
1590                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1591                                   "Unsupported event [0x%x]\n", event));
1592                 break;
1593         }
1594
1595         acpi_notifier_call_chain(device, event, 0);
1596
1597         if (keycode) {
1598                 input_report_key(input, keycode, 1);
1599                 input_sync(input);
1600                 input_report_key(input, keycode, 0);
1601                 input_sync(input);
1602         }
1603
1604         return;
1605 }
1606
1607 static int acpi_video_resume(struct notifier_block *nb,
1608                                 unsigned long val, void *ign)
1609 {
1610         struct acpi_video_bus *video;
1611         struct acpi_video_device *video_device;
1612         int i;
1613
1614         switch (val) {
1615         case PM_HIBERNATION_PREPARE:
1616         case PM_SUSPEND_PREPARE:
1617         case PM_RESTORE_PREPARE:
1618                 return NOTIFY_DONE;
1619         }
1620
1621         video = container_of(nb, struct acpi_video_bus, pm_nb);
1622
1623         dev_info(&video->device->dev, "Restoring backlight state\n");
1624
1625         for (i = 0; i < video->attached_count; i++) {
1626                 video_device = video->attached_array[i].bind_info;
1627                 if (video_device && video_device->backlight)
1628                         acpi_video_set_brightness(video_device->backlight);
1629         }
1630
1631         return NOTIFY_OK;
1632 }
1633
1634 static acpi_status
1635 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1636                         void **return_value)
1637 {
1638         struct acpi_device *device = context;
1639         struct acpi_device *sibling;
1640         int result;
1641
1642         if (handle == device->handle)
1643                 return AE_CTRL_TERMINATE;
1644
1645         result = acpi_bus_get_device(handle, &sibling);
1646         if (result)
1647                 return AE_OK;
1648
1649         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1650                         return AE_ALREADY_EXISTS;
1651
1652         return AE_OK;
1653 }
1654
1655 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1656 {
1657         struct backlight_properties props;
1658         struct pci_dev *pdev;
1659         acpi_handle acpi_parent;
1660         struct device *parent = NULL;
1661         int result;
1662         static int count;
1663         char *name;
1664
1665         /*
1666          * Do not create backlight device for video output
1667          * device that is not in the enumerated list.
1668          */
1669         if (!acpi_video_device_in_dod(device)) {
1670                 dev_dbg(&device->dev->dev, "not in _DOD list, ignore\n");
1671                 return;
1672         }
1673
1674         result = acpi_video_init_brightness(device);
1675         if (result)
1676                 return;
1677         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1678         if (!name)
1679                 return;
1680         count++;
1681
1682         acpi_get_parent(device->dev->handle, &acpi_parent);
1683
1684         pdev = acpi_get_pci_dev(acpi_parent);
1685         if (pdev) {
1686                 parent = &pdev->dev;
1687                 pci_dev_put(pdev);
1688         }
1689
1690         memset(&props, 0, sizeof(struct backlight_properties));
1691         props.type = BACKLIGHT_FIRMWARE;
1692         props.max_brightness = device->brightness->count - 3;
1693         device->backlight = backlight_device_register(name,
1694                                                       parent,
1695                                                       device,
1696                                                       &acpi_backlight_ops,
1697                                                       &props);
1698         kfree(name);
1699         if (IS_ERR(device->backlight))
1700                 return;
1701
1702         /*
1703          * Save current brightness level in case we have to restore it
1704          * before acpi_video_device_lcd_set_level() is called next time.
1705          */
1706         device->backlight->props.brightness =
1707                         acpi_video_get_brightness(device->backlight);
1708
1709         device->cooling_dev = thermal_cooling_device_register("LCD",
1710                                 device->dev, &video_cooling_ops);
1711         if (IS_ERR(device->cooling_dev)) {
1712                 /*
1713                  * Set cooling_dev to NULL so we don't crash trying to free it.
1714                  * Also, why the hell we are returning early and not attempt to
1715                  * register video output if cooling device registration failed?
1716                  * -- dtor
1717                  */
1718                 device->cooling_dev = NULL;
1719                 return;
1720         }
1721
1722         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1723                  device->cooling_dev->id);
1724         result = sysfs_create_link(&device->dev->dev.kobj,
1725                         &device->cooling_dev->device.kobj,
1726                         "thermal_cooling");
1727         if (result)
1728                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1729         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1730                         &device->dev->dev.kobj, "device");
1731         if (result)
1732                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1733 }
1734
1735 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1736 {
1737         struct acpi_video_device *dev;
1738         union acpi_object *levels;
1739
1740         mutex_lock(&video->device_list_lock);
1741         list_for_each_entry(dev, &video->video_device_list, entry) {
1742                 if (!acpi_video_device_lcd_query_levels(dev, &levels))
1743                         kfree(levels);
1744         }
1745         mutex_unlock(&video->device_list_lock);
1746 }
1747
1748 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1749 {
1750         struct acpi_video_device *dev;
1751
1752         if (video->backlight_registered)
1753                 return 0;
1754
1755         acpi_video_run_bcl_for_osi(video);
1756
1757         if (!acpi_video_verify_backlight_support())
1758                 return 0;
1759
1760         mutex_lock(&video->device_list_lock);
1761         list_for_each_entry(dev, &video->video_device_list, entry)
1762                 acpi_video_dev_register_backlight(dev);
1763         mutex_unlock(&video->device_list_lock);
1764
1765         video->backlight_registered = true;
1766
1767         video->pm_nb.notifier_call = acpi_video_resume;
1768         video->pm_nb.priority = 0;
1769         return register_pm_notifier(&video->pm_nb);
1770 }
1771
1772 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1773 {
1774         if (device->backlight) {
1775                 backlight_device_unregister(device->backlight);
1776                 device->backlight = NULL;
1777         }
1778         if (device->brightness) {
1779                 kfree(device->brightness->levels);
1780                 kfree(device->brightness);
1781                 device->brightness = NULL;
1782         }
1783         if (device->cooling_dev) {
1784                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1785                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1786                 thermal_cooling_device_unregister(device->cooling_dev);
1787                 device->cooling_dev = NULL;
1788         }
1789 }
1790
1791 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1792 {
1793         struct acpi_video_device *dev;
1794         int error;
1795
1796         if (!video->backlight_registered)
1797                 return 0;
1798
1799         error = unregister_pm_notifier(&video->pm_nb);
1800
1801         mutex_lock(&video->device_list_lock);
1802         list_for_each_entry(dev, &video->video_device_list, entry)
1803                 acpi_video_dev_unregister_backlight(dev);
1804         mutex_unlock(&video->device_list_lock);
1805
1806         video->backlight_registered = false;
1807
1808         return error;
1809 }
1810
1811 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1812 {
1813         acpi_status status;
1814         struct acpi_device *adev = device->dev;
1815
1816         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1817                                              acpi_video_device_notify, device);
1818         if (ACPI_FAILURE(status))
1819                 dev_err(&adev->dev, "Error installing notify handler\n");
1820         else
1821                 device->flags.notify = 1;
1822 }
1823
1824 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1825 {
1826         struct input_dev *input;
1827         struct acpi_video_device *dev;
1828         int error;
1829
1830         video->input = input = input_allocate_device();
1831         if (!input) {
1832                 error = -ENOMEM;
1833                 goto out;
1834         }
1835
1836         error = acpi_video_bus_start_devices(video);
1837         if (error)
1838                 goto err_free_input;
1839
1840         snprintf(video->phys, sizeof(video->phys),
1841                         "%s/video/input0", acpi_device_hid(video->device));
1842
1843         input->name = acpi_device_name(video->device);
1844         input->phys = video->phys;
1845         input->id.bustype = BUS_HOST;
1846         input->id.product = 0x06;
1847         input->dev.parent = &video->device->dev;
1848         input->evbit[0] = BIT(EV_KEY);
1849         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1850         set_bit(KEY_VIDEO_NEXT, input->keybit);
1851         set_bit(KEY_VIDEO_PREV, input->keybit);
1852         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1853         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1854         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1855         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1856         set_bit(KEY_DISPLAY_OFF, input->keybit);
1857
1858         error = input_register_device(input);
1859         if (error)
1860                 goto err_stop_dev;
1861
1862         mutex_lock(&video->device_list_lock);
1863         list_for_each_entry(dev, &video->video_device_list, entry)
1864                 acpi_video_dev_add_notify_handler(dev);
1865         mutex_unlock(&video->device_list_lock);
1866
1867         return 0;
1868
1869 err_stop_dev:
1870         acpi_video_bus_stop_devices(video);
1871 err_free_input:
1872         input_free_device(input);
1873         video->input = NULL;
1874 out:
1875         return error;
1876 }
1877
1878 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1879 {
1880         if (dev->flags.notify) {
1881                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1882                                            acpi_video_device_notify);
1883                 dev->flags.notify = 0;
1884         }
1885 }
1886
1887 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1888 {
1889         struct acpi_video_device *dev;
1890
1891         mutex_lock(&video->device_list_lock);
1892         list_for_each_entry(dev, &video->video_device_list, entry)
1893                 acpi_video_dev_remove_notify_handler(dev);
1894         mutex_unlock(&video->device_list_lock);
1895
1896         acpi_video_bus_stop_devices(video);
1897         input_unregister_device(video->input);
1898         video->input = NULL;
1899 }
1900
1901 static int acpi_video_backlight_notify(struct notifier_block *nb,
1902                                         unsigned long val, void *bd)
1903 {
1904         struct backlight_device *backlight = bd;
1905         struct acpi_video_bus *video;
1906
1907         /* acpi_video_verify_backlight_support only cares about raw devices */
1908         if (backlight->props.type != BACKLIGHT_RAW)
1909                 return NOTIFY_DONE;
1910
1911         video = container_of(nb, struct acpi_video_bus, backlight_nb);
1912
1913         switch (val) {
1914         case BACKLIGHT_REGISTERED:
1915                 if (!acpi_video_verify_backlight_support())
1916                         acpi_video_bus_unregister_backlight(video);
1917                 break;
1918         case BACKLIGHT_UNREGISTERED:
1919                 acpi_video_bus_register_backlight(video);
1920                 break;
1921         }
1922
1923         return NOTIFY_OK;
1924 }
1925
1926 static int acpi_video_bus_add_backlight_notify_handler(
1927                                                 struct acpi_video_bus *video)
1928 {
1929         int error;
1930
1931         video->backlight_nb.notifier_call = acpi_video_backlight_notify;
1932         video->backlight_nb.priority = 0;
1933         error = backlight_register_notifier(&video->backlight_nb);
1934         if (error == 0)
1935                 video->backlight_notifier_registered = true;
1936
1937         return error;
1938 }
1939
1940 static int acpi_video_bus_remove_backlight_notify_handler(
1941                                                 struct acpi_video_bus *video)
1942 {
1943         if (!video->backlight_notifier_registered)
1944                 return 0;
1945
1946         video->backlight_notifier_registered = false;
1947
1948         return backlight_unregister_notifier(&video->backlight_nb);
1949 }
1950
1951 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1952 {
1953         struct acpi_video_device *dev, *next;
1954
1955         mutex_lock(&video->device_list_lock);
1956         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1957                 list_del(&dev->entry);
1958                 kfree(dev);
1959         }
1960         mutex_unlock(&video->device_list_lock);
1961
1962         return 0;
1963 }
1964
1965 static int instance;
1966
1967 static int acpi_video_bus_add(struct acpi_device *device)
1968 {
1969         struct acpi_video_bus *video;
1970         int error;
1971         acpi_status status;
1972
1973         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1974                                 device->parent->handle, 1,
1975                                 acpi_video_bus_match, NULL,
1976                                 device, NULL);
1977         if (status == AE_ALREADY_EXISTS) {
1978                 printk(KERN_WARNING FW_BUG
1979                         "Duplicate ACPI video bus devices for the"
1980                         " same VGA controller, please try module "
1981                         "parameter \"video.allow_duplicates=1\""
1982                         "if the current driver doesn't work.\n");
1983                 if (!allow_duplicates)
1984                         return -ENODEV;
1985         }
1986
1987         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1988         if (!video)
1989                 return -ENOMEM;
1990
1991         /* a hack to fix the duplicate name "VID" problem on T61 */
1992         if (!strcmp(device->pnp.bus_id, "VID")) {
1993                 if (instance)
1994                         device->pnp.bus_id[3] = '0' + instance;
1995                 instance++;
1996         }
1997         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1998         if (!strcmp(device->pnp.bus_id, "VGA")) {
1999                 if (instance)
2000                         device->pnp.bus_id[3] = '0' + instance;
2001                 instance++;
2002         }
2003
2004         video->device = device;
2005         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2006         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2007         device->driver_data = video;
2008
2009         acpi_video_bus_find_cap(video);
2010         error = acpi_video_bus_check(video);
2011         if (error)
2012                 goto err_free_video;
2013
2014         mutex_init(&video->device_list_lock);
2015         INIT_LIST_HEAD(&video->video_device_list);
2016
2017         error = acpi_video_bus_get_devices(video, device);
2018         if (error)
2019                 goto err_put_video;
2020
2021         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2022                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2023                video->flags.multihead ? "yes" : "no",
2024                video->flags.rom ? "yes" : "no",
2025                video->flags.post ? "yes" : "no");
2026         mutex_lock(&video_list_lock);
2027         list_add_tail(&video->entry, &video_bus_head);
2028         mutex_unlock(&video_list_lock);
2029
2030         acpi_video_bus_register_backlight(video);
2031         acpi_video_bus_add_notify_handler(video);
2032         acpi_video_bus_add_backlight_notify_handler(video);
2033
2034         return 0;
2035
2036 err_put_video:
2037         acpi_video_bus_put_devices(video);
2038         kfree(video->attached_array);
2039 err_free_video:
2040         kfree(video);
2041         device->driver_data = NULL;
2042
2043         return error;
2044 }
2045
2046 static int acpi_video_bus_remove(struct acpi_device *device)
2047 {
2048         struct acpi_video_bus *video = NULL;
2049
2050
2051         if (!device || !acpi_driver_data(device))
2052                 return -EINVAL;
2053
2054         video = acpi_driver_data(device);
2055
2056         acpi_video_bus_remove_backlight_notify_handler(video);
2057         acpi_video_bus_remove_notify_handler(video);
2058         acpi_video_bus_unregister_backlight(video);
2059         acpi_video_bus_put_devices(video);
2060
2061         mutex_lock(&video_list_lock);
2062         list_del(&video->entry);
2063         mutex_unlock(&video_list_lock);
2064
2065         kfree(video->attached_array);
2066         kfree(video);
2067
2068         return 0;
2069 }
2070
2071 static int __init is_i740(struct pci_dev *dev)
2072 {
2073         if (dev->device == 0x00D1)
2074                 return 1;
2075         if (dev->device == 0x7000)
2076                 return 1;
2077         return 0;
2078 }
2079
2080 static int __init intel_opregion_present(void)
2081 {
2082         int opregion = 0;
2083         struct pci_dev *dev = NULL;
2084         u32 address;
2085
2086         for_each_pci_dev(dev) {
2087                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2088                         continue;
2089                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2090                         continue;
2091                 /* We don't want to poke around undefined i740 registers */
2092                 if (is_i740(dev))
2093                         continue;
2094                 pci_read_config_dword(dev, 0xfc, &address);
2095                 if (!address)
2096                         continue;
2097                 opregion = 1;
2098         }
2099         return opregion;
2100 }
2101
2102 int acpi_video_register(void)
2103 {
2104         int result = 0;
2105         if (register_count) {
2106                 /*
2107                  * if the function of acpi_video_register is already called,
2108                  * don't register the acpi_vide_bus again and return no error.
2109                  */
2110                 return 0;
2111         }
2112
2113         mutex_init(&video_list_lock);
2114         INIT_LIST_HEAD(&video_bus_head);
2115
2116         result = acpi_bus_register_driver(&acpi_video_bus);
2117         if (result < 0)
2118                 return -ENODEV;
2119
2120         /*
2121          * When the acpi_video_bus is loaded successfully, increase
2122          * the counter reference.
2123          */
2124         register_count = 1;
2125
2126         return 0;
2127 }
2128 EXPORT_SYMBOL(acpi_video_register);
2129
2130 void acpi_video_unregister(void)
2131 {
2132         if (!register_count) {
2133                 /*
2134                  * If the acpi video bus is already unloaded, don't
2135                  * unload it again and return directly.
2136                  */
2137                 return;
2138         }
2139         acpi_bus_unregister_driver(&acpi_video_bus);
2140
2141         register_count = 0;
2142
2143         return;
2144 }
2145 EXPORT_SYMBOL(acpi_video_unregister);
2146
2147 void acpi_video_unregister_backlight(void)
2148 {
2149         struct acpi_video_bus *video;
2150
2151         if (!register_count)
2152                 return;
2153
2154         mutex_lock(&video_list_lock);
2155         list_for_each_entry(video, &video_bus_head, entry)
2156                 acpi_video_bus_unregister_backlight(video);
2157         mutex_unlock(&video_list_lock);
2158 }
2159 EXPORT_SYMBOL(acpi_video_unregister_backlight);
2160
2161 /*
2162  * This is kind of nasty. Hardware using Intel chipsets may require
2163  * the video opregion code to be run first in order to initialise
2164  * state before any ACPI video calls are made. To handle this we defer
2165  * registration of the video class until the opregion code has run.
2166  */
2167
2168 static int __init acpi_video_init(void)
2169 {
2170         dmi_check_system(video_dmi_table);
2171
2172         if (intel_opregion_present())
2173                 return 0;
2174
2175         return acpi_video_register();
2176 }
2177
2178 static void __exit acpi_video_exit(void)
2179 {
2180         acpi_video_unregister();
2181
2182         return;
2183 }
2184
2185 module_init(acpi_video_init);
2186 module_exit(acpi_video_exit);