drivers/acpi/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  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/list.h>
  28 #include <linux/mutex.h>
  29 #include <linux/input.h>
  30 #include <linux/backlight.h>
  31 #include <linux/thermal.h>
  32 #include <linux/sort.h>
  33 #include <linux/pci.h>
  34 #include <linux/pci_ids.h>
  35 #include <linux/slab.h>
  36 #include <linux/dmi.h>
  37 #include <linux/suspend.h>
  38 #include <linux/acpi.h>
  39 #include <acpi/video.h>
  40 #include <asm/uaccess.h>
  41
  42 #define PREFIX "ACPI: "
  43
  44 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
  45 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  46 #define ACPI_VIDEO_NOTIFY_SWITCH        0x80
  47 #define ACPI_VIDEO_NOTIFY_PROBE         0x81
  48 #define ACPI_VIDEO_NOTIFY_CYCLE         0x82
  49 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT   0x83
  50 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT   0x84
  51
  52 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS      0x85
  53 #define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS        0x86
  54 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS        0x87
  55 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS       0x88
  56 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF           0x89
  57
  58 #define MAX_NAME_LEN    20
  59
  60 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  61 ACPI_MODULE_NAME("video");
  62
  63 MODULE_AUTHOR("Bruno Ducrot");
  64 MODULE_DESCRIPTION("ACPI Video Driver");
  65 MODULE_LICENSE("GPL");
  66
  67 static bool brightness_switch_enabled = 1;
  68 module_param(brightness_switch_enabled, bool, 0644);
  69
  70 /*
  71  * By default, we don't allow duplicate ACPI video bus devices
  72  * under the same VGA controller
  73  */
  74 static bool allow_duplicates;
  75 module_param(allow_duplicates, bool, 0644);
  76
  77 static int disable_backlight_sysfs_if = -1;
  78 module_param(disable_backlight_sysfs_if, int, 0444);
  79
  80 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  81 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  82 static int report_key_events = -1;
  83 module_param(report_key_events, int, 0644);
  84 MODULE_PARM_DESC(report_key_events,
  85         "0: none, 1: output changes, 2: brightness changes, 3: all");
  86
  87 static bool device_id_scheme = false;
  88 module_param(device_id_scheme, bool, 0444);
  89
  90 static bool only_lcd = false;
  91 module_param(only_lcd, bool, 0444);
  92
  93 static int register_count;
  94 static DEFINE_MUTEX(register_count_mutex);
  95 static DEFINE_MUTEX(video_list_lock);
  96 static LIST_HEAD(video_bus_head);
  97 static int acpi_video_bus_add(struct acpi_device *device);
  98 static int acpi_video_bus_remove(struct acpi_device *device);
  99 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
 100 void acpi_video_detect_exit(void);
 101
 102 static const struct acpi_device_id video_device_ids[] = {
 103         {ACPI_VIDEO_HID, 0},
 104         {"", 0},
 105 };
 106 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 107
 108 static struct acpi_driver acpi_video_bus = {
 109         .name = "video",
 110         .class = ACPI_VIDEO_CLASS,
 111         .ids = video_device_ids,
 112         .ops = {
 113                 .add = acpi_video_bus_add,
 114                 .remove = acpi_video_bus_remove,
 115                 .notify = acpi_video_bus_notify,
 116                 },
 117 };
 118
 119 struct acpi_video_bus_flags {
 120         u8 multihead:1;         /* can switch video heads */
 121         u8 rom:1;               /* can retrieve a video rom */
 122         u8 post:1;              /* can configure the head to */
 123         u8 reserved:5;
 124 };
 125
 126 struct acpi_video_bus_cap {
 127         u8 _DOS:1;              /* Enable/Disable output switching */
 128         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 129         u8 _ROM:1;              /* Get ROM Data */
 130         u8 _GPD:1;              /* Get POST Device */
 131         u8 _SPD:1;              /* Set POST Device */
 132         u8 _VPO:1;              /* Video POST Options */
 133         u8 reserved:2;
 134 };
 135
 136 struct acpi_video_device_attrib {
 137         u32 display_index:4;    /* A zero-based instance of the Display */
 138         u32 display_port_attachment:4;  /* This field differentiates the display type */
 139         u32 display_type:4;     /* Describe the specific type in use */
 140         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 141         u32 bios_can_detect:1;  /* BIOS can detect the device */
 142         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 143                                    the VGA device. */
 144         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 145         u32 reserved:10;        /* Must be 0 */
 146         u32 device_id_scheme:1; /* Device ID Scheme */
 147 };
 148
 149 struct acpi_video_enumerated_device {
 150         union {
 151                 u32 int_val;
 152                 struct acpi_video_device_attrib attrib;
 153         } value;
 154         struct acpi_video_device *bind_info;
 155 };
 156
 157 struct acpi_video_bus {
 158         struct acpi_device *device;
 159         bool backlight_registered;
 160         u8 dos_setting;
 161         struct acpi_video_enumerated_device *attached_array;
 162         u8 attached_count;
 163         u8 child_count;
 164         struct acpi_video_bus_cap cap;
 165         struct acpi_video_bus_flags flags;
 166         struct list_head video_device_list;
 167         struct mutex device_list_lock;  /* protects video_device_list */
 168         struct list_head entry;
 169         struct input_dev *input;
 170         char phys[32];  /* for input device */
 171         struct notifier_block pm_nb;
 172 };
 173
 174 struct acpi_video_device_flags {
 175         u8 crt:1;
 176         u8 lcd:1;
 177         u8 tvout:1;
 178         u8 dvi:1;
 179         u8 bios:1;
 180         u8 unknown:1;
 181         u8 notify:1;
 182         u8 reserved:1;
 183 };
 184
 185 struct acpi_video_device_cap {
 186         u8 _ADR:1;              /* Return the unique ID */
 187         u8 _BCL:1;              /* Query list of brightness control levels supported */
 188         u8 _BCM:1;              /* Set the brightness level */
 189         u8 _BQC:1;              /* Get current brightness level */
 190         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 191         u8 _DDC:1;              /* Return the EDID for this device */
 192 };
 193
 194 struct acpi_video_brightness_flags {
 195         u8 _BCL_no_ac_battery_levels:1; /* no AC/Battery levels in _BCL */
 196         u8 _BCL_reversed:1;             /* _BCL package is in a reversed order */
 197         u8 _BQC_use_index:1;            /* _BQC returns an index value */
 198 };
 199
 200 struct acpi_video_device_brightness {
 201         int curr;
 202         int count;
 203         int *levels;
 204         struct acpi_video_brightness_flags flags;
 205 };
 206
 207 struct acpi_video_device {
 208         unsigned long device_id;
 209         struct acpi_video_device_flags flags;
 210         struct acpi_video_device_cap cap;
 211         struct list_head entry;
 212         struct delayed_work switch_brightness_work;
 213         int switch_brightness_event;
 214         struct acpi_video_bus *video;
 215         struct acpi_device *dev;
 216         struct acpi_video_device_brightness *brightness;
 217         struct backlight_device *backlight;
 218         struct thermal_cooling_device *cooling_dev;
 219 };
 220
 221 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 222 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 223 static void acpi_video_device_bind(struct acpi_video_bus *video,
 224                                    struct acpi_video_device *device);
 225 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 226 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 227                         int level);
 228 static int acpi_video_device_lcd_get_level_current(
 229                         struct acpi_video_device *device,
 230                         unsigned long long *level, bool raw);
 231 static int acpi_video_get_next_level(struct acpi_video_device *device,
 232                                      u32 level_current, u32 event);
 233 static void acpi_video_switch_brightness(struct work_struct *work);
 234
 235 /* backlight device sysfs support */
 236 static int acpi_video_get_brightness(struct backlight_device *bd)
 237 {
 238         unsigned long long cur_level;
 239         int i;
 240         struct acpi_video_device *vd = bl_get_data(bd);
 241
 242         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 243                 return -EINVAL;
 244         for (i = 2; i < vd->brightness->count; i++) {
 245                 if (vd->brightness->levels[i] == cur_level)
 246                         /*
 247                          * The first two entries are special - see page 575
 248                          * of the ACPI spec 3.0
 249                          */
 250                         return i - 2;
 251         }
 252         return 0;
 253 }
 254
 255 static int acpi_video_set_brightness(struct backlight_device *bd)
 256 {
 257         int request_level = bd->props.brightness + 2;
 258         struct acpi_video_device *vd = bl_get_data(bd);
 259
 260         cancel_delayed_work(&vd->switch_brightness_work);
 261         return acpi_video_device_lcd_set_level(vd,
 262                                 vd->brightness->levels[request_level]);
 263 }
 264
 265 static const struct backlight_ops acpi_backlight_ops = {
 266         .get_brightness = acpi_video_get_brightness,
 267         .update_status  = acpi_video_set_brightness,
 268 };
 269
 270 /* thermal cooling device callbacks */
 271 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
 272                                long *state)
 273 {
 274         struct acpi_device *device = cooling_dev->devdata;
 275         struct acpi_video_device *video = acpi_driver_data(device);
 276
 277         *state = video->brightness->count - 3;
 278         return 0;
 279 }
 280
 281 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
 282                                long *state)
 283 {
 284         struct acpi_device *device = cooling_dev->devdata;
 285         struct acpi_video_device *video = acpi_driver_data(device);
 286         unsigned long long level;
 287         int offset;
 288
 289         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 290                 return -EINVAL;
 291         for (offset = 2; offset < video->brightness->count; offset++)
 292                 if (level == video->brightness->levels[offset]) {
 293                         *state = video->brightness->count - offset - 1;
 294                         return 0;
 295                 }
 296
 297         return -EINVAL;
 298 }
 299
 300 static int
 301 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 302 {
 303         struct acpi_device *device = cooling_dev->devdata;
 304         struct acpi_video_device *video = acpi_driver_data(device);
 305         int level;
 306
 307         if (state >= video->brightness->count - 2)
 308                 return -EINVAL;
 309
 310         state = video->brightness->count - state;
 311         level = video->brightness->levels[state - 1];
 312         return acpi_video_device_lcd_set_level(video, level);
 313 }
 314
 315 static const struct thermal_cooling_device_ops video_cooling_ops = {
 316         .get_max_state = video_get_max_state,
 317         .get_cur_state = video_get_cur_state,
 318         .set_cur_state = video_set_cur_state,
 319 };
 320
 321 /*
 322  * --------------------------------------------------------------------------
 323  *                             Video Management
 324  * --------------------------------------------------------------------------
 325  */
 326
 327 static int
 328 acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
 329                                    union acpi_object **levels)
 330 {
 331         int status;
 332         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 333         union acpi_object *obj;
 334
 335
 336         *levels = NULL;
 337
 338         status = acpi_evaluate_object(device->dev->handle, "_BCL", NULL, &buffer);
 339         if (!ACPI_SUCCESS(status))
 340                 return status;
 341         obj = (union acpi_object *)buffer.pointer;
 342         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 343                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 344                 status = -EFAULT;
 345                 goto err;
 346         }
 347
 348         *levels = obj;
 349
 350         return 0;
 351
 352 err:
 353         kfree(buffer.pointer);
 354
 355         return status;
 356 }
 357
 358 static int
 359 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 360 {
 361         int status;
 362         int state;
 363
 364         status = acpi_execute_simple_method(device->dev->handle,
 365                                             "_BCM", level);
 366         if (ACPI_FAILURE(status)) {
 367                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 368                 return -EIO;
 369         }
 370
 371         device->brightness->curr = level;
 372         for (state = 2; state < device->brightness->count; state++)
 373                 if (level == device->brightness->levels[state]) {
 374                         if (device->backlight)
 375                                 device->backlight->props.brightness = state - 2;
 376                         return 0;
 377                 }
 378
 379         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 380         return -EINVAL;
 381 }
 382
 383 /*
 384  * For some buggy _BQC methods, we need to add a constant value to
 385  * the _BQC return value to get the actual current brightness level
 386  */
 387
 388 static int bqc_offset_aml_bug_workaround;
 389 static int video_set_bqc_offset(const struct dmi_system_id *d)
 390 {
 391         bqc_offset_aml_bug_workaround = 9;
 392         return 0;
 393 }
 394
 395 static int video_disable_backlight_sysfs_if(
 396         const struct dmi_system_id *d)
 397 {
 398         if (disable_backlight_sysfs_if == -1)
 399                 disable_backlight_sysfs_if = 1;
 400         return 0;
 401 }
 402
 403 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 404 {
 405         device_id_scheme = true;
 406         return 0;
 407 }
 408
 409 static int video_enable_only_lcd(const struct dmi_system_id *d)
 410 {
 411         only_lcd = true;
 412         return 0;
 413 }
 414
 415 static int video_set_report_key_events(const struct dmi_system_id *id)
 416 {
 417         if (report_key_events == -1)
 418                 report_key_events = (uintptr_t)id->driver_data;
 419         return 0;
 420 }
 421
 422 static struct dmi_system_id video_dmi_table[] = {
 423         /*
 424          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 425          */
 426         {
 427          .callback = video_set_bqc_offset,
 428          .ident = "Acer Aspire 5720",
 429          .matches = {
 430                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 431                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 432                 },
 433         },
 434         {
 435          .callback = video_set_bqc_offset,
 436          .ident = "Acer Aspire 5710Z",
 437          .matches = {
 438                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 439                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 440                 },
 441         },
 442         {
 443          .callback = video_set_bqc_offset,
 444          .ident = "eMachines E510",
 445          .matches = {
 446                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 447                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 448                 },
 449         },
 450         {
 451          .callback = video_set_bqc_offset,
 452          .ident = "Acer Aspire 5315",
 453          .matches = {
 454                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 455                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 456                 },
 457         },
 458         {
 459          .callback = video_set_bqc_offset,
 460          .ident = "Acer Aspire 7720",
 461          .matches = {
 462                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 463                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 464                 },
 465         },
 466
 467         /*
 468          * Some machines have a broken acpi-video interface for brightness
 469          * control, but still need an acpi_video_device_lcd_set_level() call
 470          * on resume to turn the backlight power on.  We Enable backlight
 471          * control on these systems, but do not register a backlight sysfs
 472          * as brightness control does not work.
 473          */
 474         {
 475          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 476          .callback = video_disable_backlight_sysfs_if,
 477          .ident = "Toshiba Portege R700",
 478          .matches = {
 479                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 480                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 481                 },
 482         },
 483         {
 484          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 485          .callback = video_disable_backlight_sysfs_if,
 486          .ident = "Toshiba Portege R830",
 487          .matches = {
 488                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 489                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 490                 },
 491         },
 492         {
 493          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 494          .callback = video_disable_backlight_sysfs_if,
 495          .ident = "Toshiba Satellite R830",
 496          .matches = {
 497                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 498                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 499                 },
 500         },
 501         /*
 502          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 503          * but the IDs actually follow the Device ID Scheme.
 504          */
 505         {
 506          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 507          .callback = video_set_device_id_scheme,
 508          .ident = "ESPRIMO Mobile M9410",
 509          .matches = {
 510                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 511                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 512                 },
 513         },
 514         /*
 515          * Some machines have multiple video output devices, but only the one
 516          * that is the type of LCD can do the backlight control so we should not
 517          * register backlight interface for other video output devices.
 518          */
 519         {
 520          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 521          .callback = video_enable_only_lcd,
 522          .ident = "ESPRIMO Mobile M9410",
 523          .matches = {
 524                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 525                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 526                 },
 527         },
 528         /*
 529          * Some machines report wrong key events on the acpi-bus, suppress
 530          * key event reporting on these.  Note this is only intended to work
 531          * around events which are plain wrong. In some cases we get double
 532          * events, in this case acpi-video is considered the canonical source
 533          * and the events from the other source should be filtered. E.g.
 534          * by calling acpi_video_handles_brightness_key_presses() from the
 535          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 536          */
 537         {
 538          .callback = video_set_report_key_events,
 539          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 540          .ident = "Dell Vostro V131",
 541          .matches = {
 542                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 543                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 544                 },
 545         },
 546         {}
 547 };
 548
 549 static unsigned long long
 550 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 551                               unsigned long long bqc_value)
 552 {
 553         unsigned long long level;
 554
 555         if (device->brightness->flags._BQC_use_index) {
 556                 /*
 557                  * _BQC returns an index that doesn't account for
 558                  * the first 2 items with special meaning, so we need
 559                  * to compensate for that by offsetting ourselves
 560                  */
 561                 if (device->brightness->flags._BCL_reversed)
 562                         bqc_value = device->brightness->count - 3 - bqc_value;
 563
 564                 level = device->brightness->levels[bqc_value + 2];
 565         } else {
 566                 level = bqc_value;
 567         }
 568
 569         level += bqc_offset_aml_bug_workaround;
 570
 571         return level;
 572 }
 573
 574 static int
 575 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 576                                         unsigned long long *level, bool raw)
 577 {
 578         acpi_status status = AE_OK;
 579         int i;
 580
 581         if (device->cap._BQC || device->cap._BCQ) {
 582                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 583
 584                 status = acpi_evaluate_integer(device->dev->handle, buf,
 585                                                 NULL, level);
 586                 if (ACPI_SUCCESS(status)) {
 587                         if (raw) {
 588                                 /*
 589                                  * Caller has indicated he wants the raw
 590                                  * value returned by _BQC, so don't furtherly
 591                                  * mess with the value.
 592                                  */
 593                                 return 0;
 594                         }
 595
 596                         *level = acpi_video_bqc_value_to_level(device, *level);
 597
 598                         for (i = 2; i < device->brightness->count; i++)
 599                                 if (device->brightness->levels[i] == *level) {
 600                                         device->brightness->curr = *level;
 601                                         return 0;
 602                                 }
 603                         /*
 604                          * BQC returned an invalid level.
 605                          * Stop using it.
 606                          */
 607                         ACPI_WARNING((AE_INFO,
 608                                       "%s returned an invalid level",
 609                                       buf));
 610                         device->cap._BQC = device->cap._BCQ = 0;
 611                 } else {
 612                         /*
 613                          * Fixme:
 614                          * should we return an error or ignore this failure?
 615                          * dev->brightness->curr is a cached value which stores
 616                          * the correct current backlight level in most cases.
 617                          * ACPI video backlight still works w/ buggy _BQC.
 618                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 619                          */
 620                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 621                         device->cap._BQC = device->cap._BCQ = 0;
 622                 }
 623         }
 624
 625         *level = device->brightness->curr;
 626         return 0;
 627 }
 628
 629 static int
 630 acpi_video_device_EDID(struct acpi_video_device *device,
 631                        union acpi_object **edid, ssize_t length)
 632 {
 633         int status;
 634         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 635         union acpi_object *obj;
 636         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 637         struct acpi_object_list args = { 1, &arg0 };
 638
 639
 640         *edid = NULL;
 641
 642         if (!device)
 643                 return -ENODEV;
 644         if (length == 128)
 645                 arg0.integer.value = 1;
 646         else if (length == 256)
 647                 arg0.integer.value = 2;
 648         else
 649                 return -EINVAL;
 650
 651         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 652         if (ACPI_FAILURE(status))
 653                 return -ENODEV;
 654
 655         obj = buffer.pointer;
 656
 657         if (obj && obj->type == ACPI_TYPE_BUFFER)
 658                 *edid = obj;
 659         else {
 660                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 661                 status = -EFAULT;
 662                 kfree(obj);
 663         }
 664
 665         return status;
 666 }
 667
 668 /* bus */
 669
 670 /*
 671  *  Arg:
 672  *      video           : video bus device pointer
 673  *      bios_flag       :
 674  *              0.      The system BIOS should NOT automatically switch(toggle)
 675  *                      the active display output.
 676  *              1.      The system BIOS should automatically switch (toggle) the
 677  *                      active display output. No switch event.
 678  *              2.      The _DGS value should be locked.
 679  *              3.      The system BIOS should not automatically switch (toggle) the
 680  *                      active display output, but instead generate the display switch
 681  *                      event notify code.
 682  *      lcd_flag        :
 683  *              0.      The system BIOS should automatically control the brightness level
 684  *                      of the LCD when the power changes from AC to DC
 685  *              1.      The system BIOS should NOT automatically control the brightness
 686  *                      level of the LCD when the power changes from AC to DC.
 687  *  Return Value:
 688  *              -EINVAL wrong arg.
 689  */
 690
 691 static int
 692 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 693 {
 694         acpi_status status;
 695
 696         if (!video->cap._DOS)
 697                 return 0;
 698
 699         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 700                 return -EINVAL;
 701         video->dos_setting = (lcd_flag << 2) | bios_flag;
 702         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 703                                             (lcd_flag << 2) | bios_flag);
 704         if (ACPI_FAILURE(status))
 705                 return -EIO;
 706
 707         return 0;
 708 }
 709
 710 /*
 711  * Simple comparison function used to sort backlight levels.
 712  */
 713
 714 static int
 715 acpi_video_cmp_level(const void *a, const void *b)
 716 {
 717         return *(int *)a - *(int *)b;
 718 }
 719
 720 /*
 721  * Decides if _BQC/_BCQ for this system is usable
 722  *
 723  * We do this by changing the level first and then read out the current
 724  * brightness level, if the value does not match, find out if it is using
 725  * index. If not, clear the _BQC/_BCQ capability.
 726  */
 727 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 728                                 int max_level, int current_level)
 729 {
 730         struct acpi_video_device_brightness *br = device->brightness;
 731         int result;
 732         unsigned long long level;
 733         int test_level;
 734
 735         /* don't mess with existing known broken systems */
 736         if (bqc_offset_aml_bug_workaround)
 737                 return 0;
 738
 739         /*
 740          * Some systems always report current brightness level as maximum
 741          * through _BQC, we need to test another value for them.
 742          */
 743         test_level = current_level == max_level ? br->levels[3] : max_level;
 744
 745         result = acpi_video_device_lcd_set_level(device, test_level);
 746         if (result)
 747                 return result;
 748
 749         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 750         if (result)
 751                 return result;
 752
 753         if (level != test_level) {
 754                 /* buggy _BQC found, need to find out if it uses index */
 755                 if (level < br->count) {
 756                         if (br->flags._BCL_reversed)
 757                                 level = br->count - 3 - level;
 758                         if (br->levels[level + 2] == test_level)
 759                                 br->flags._BQC_use_index = 1;
 760                 }
 761
 762                 if (!br->flags._BQC_use_index)
 763                         device->cap._BQC = device->cap._BCQ = 0;
 764         }
 765
 766         return 0;
 767 }
 768
 769
 770 /*
 771  *  Arg:
 772  *      device  : video output device (LCD, CRT, ..)
 773  *
 774  *  Return Value:
 775  *      Maximum brightness level
 776  *
 777  *  Allocate and initialize device->brightness.
 778  */
 779
 780 static int
 781 acpi_video_init_brightness(struct acpi_video_device *device)
 782 {
 783         union acpi_object *obj = NULL;
 784         int i, max_level = 0, count = 0, level_ac_battery = 0;
 785         unsigned long long level, level_old;
 786         union acpi_object *o;
 787         struct acpi_video_device_brightness *br = NULL;
 788         int result = -EINVAL;
 789         u32 value;
 790
 791         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
 792                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 793                                                 "LCD brightness level\n"));
 794                 goto out;
 795         }
 796
 797         if (obj->package.count < 2)
 798                 goto out;
 799
 800         br = kzalloc(sizeof(*br), GFP_KERNEL);
 801         if (!br) {
 802                 printk(KERN_ERR "can't allocate memory\n");
 803                 result = -ENOMEM;
 804                 goto out;
 805         }
 806
 807         br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
 808                                 GFP_KERNEL);
 809         if (!br->levels) {
 810                 result = -ENOMEM;
 811                 goto out_free;
 812         }
 813
 814         for (i = 0; i < obj->package.count; i++) {
 815                 o = (union acpi_object *)&obj->package.elements[i];
 816                 if (o->type != ACPI_TYPE_INTEGER) {
 817                         printk(KERN_ERR PREFIX "Invalid data\n");
 818                         continue;
 819                 }
 820                 value = (u32) o->integer.value;
 821                 /* Skip duplicate entries */
 822                 if (count > 2 && br->levels[count - 1] == value)
 823                         continue;
 824
 825                 br->levels[count] = value;
 826
 827                 if (br->levels[count] > max_level)
 828                         max_level = br->levels[count];
 829                 count++;
 830         }
 831
 832         /*
 833          * some buggy BIOS don't export the levels
 834          * when machine is on AC/Battery in _BCL package.
 835          * In this case, the first two elements in _BCL packages
 836          * are also supported brightness levels that OS should take care of.
 837          */
 838         for (i = 2; i < count; i++) {
 839                 if (br->levels[i] == br->levels[0])
 840                         level_ac_battery++;
 841                 if (br->levels[i] == br->levels[1])
 842                         level_ac_battery++;
 843         }
 844
 845         if (level_ac_battery < 2) {
 846                 level_ac_battery = 2 - level_ac_battery;
 847                 br->flags._BCL_no_ac_battery_levels = 1;
 848                 for (i = (count - 1 + level_ac_battery); i >= 2; i--)
 849                         br->levels[i] = br->levels[i - level_ac_battery];
 850                 count += level_ac_battery;
 851         } else if (level_ac_battery > 2)
 852                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 853
 854         /* Check if the _BCL package is in a reversed order */
 855         if (max_level == br->levels[2]) {
 856                 br->flags._BCL_reversed = 1;
 857                 sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
 858                         acpi_video_cmp_level, NULL);
 859         } else if (max_level != br->levels[count - 1])
 860                 ACPI_ERROR((AE_INFO,
 861                             "Found unordered _BCL package"));
 862
 863         br->count = count;
 864         device->brightness = br;
 865
 866         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 867         br->curr = level = max_level;
 868
 869         if (!device->cap._BQC)
 870                 goto set_level;
 871
 872         result = acpi_video_device_lcd_get_level_current(device,
 873                                                          &level_old, true);
 874         if (result)
 875                 goto out_free_levels;
 876
 877         result = acpi_video_bqc_quirk(device, max_level, level_old);
 878         if (result)
 879                 goto out_free_levels;
 880         /*
 881          * cap._BQC may get cleared due to _BQC is found to be broken
 882          * in acpi_video_bqc_quirk, so check again here.
 883          */
 884         if (!device->cap._BQC)
 885                 goto set_level;
 886
 887         level = acpi_video_bqc_value_to_level(device, level_old);
 888         /*
 889          * On some buggy laptops, _BQC returns an uninitialized
 890          * value when invoked for the first time, i.e.
 891          * level_old is invalid (no matter whether it's a level
 892          * or an index). Set the backlight to max_level in this case.
 893          */
 894         for (i = 2; i < br->count; i++)
 895                 if (level == br->levels[i])
 896                         break;
 897         if (i == br->count || !level)
 898                 level = max_level;
 899
 900 set_level:
 901         result = acpi_video_device_lcd_set_level(device, level);
 902         if (result)
 903                 goto out_free_levels;
 904
 905         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 906                           "found %d brightness levels\n", count - 2));
 907         kfree(obj);
 908         return result;
 909
 910 out_free_levels:
 911         kfree(br->levels);
 912 out_free:
 913         kfree(br);
 914 out:
 915         device->brightness = NULL;
 916         kfree(obj);
 917         return result;
 918 }
 919
 920 /*
 921  *  Arg:
 922  *      device  : video output device (LCD, CRT, ..)
 923  *
 924  *  Return Value:
 925  *      None
 926  *
 927  *  Find out all required AML methods defined under the output
 928  *  device.
 929  */
 930
 931 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 932 {
 933         if (acpi_has_method(device->dev->handle, "_ADR"))
 934                 device->cap._ADR = 1;
 935         if (acpi_has_method(device->dev->handle, "_BCL"))
 936                 device->cap._BCL = 1;
 937         if (acpi_has_method(device->dev->handle, "_BCM"))
 938                 device->cap._BCM = 1;
 939         if (acpi_has_method(device->dev->handle, "_BQC")) {
 940                 device->cap._BQC = 1;
 941         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 942                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 943                 device->cap._BCQ = 1;
 944         }
 945
 946         if (acpi_has_method(device->dev->handle, "_DDC"))
 947                 device->cap._DDC = 1;
 948 }
 949
 950 /*
 951  *  Arg:
 952  *      device  : video output device (VGA)
 953  *
 954  *  Return Value:
 955  *      None
 956  *
 957  *  Find out all required AML methods defined under the video bus device.
 958  */
 959
 960 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 961 {
 962         if (acpi_has_method(video->device->handle, "_DOS"))
 963                 video->cap._DOS = 1;
 964         if (acpi_has_method(video->device->handle, "_DOD"))
 965                 video->cap._DOD = 1;
 966         if (acpi_has_method(video->device->handle, "_ROM"))
 967                 video->cap._ROM = 1;
 968         if (acpi_has_method(video->device->handle, "_GPD"))
 969                 video->cap._GPD = 1;
 970         if (acpi_has_method(video->device->handle, "_SPD"))
 971                 video->cap._SPD = 1;
 972         if (acpi_has_method(video->device->handle, "_VPO"))
 973                 video->cap._VPO = 1;
 974 }
 975
 976 /*
 977  * Check whether the video bus device has required AML method to
 978  * support the desired features
 979  */
 980
 981 static int acpi_video_bus_check(struct acpi_video_bus *video)
 982 {
 983         acpi_status status = -ENOENT;
 984         struct pci_dev *dev;
 985
 986         if (!video)
 987                 return -EINVAL;
 988
 989         dev = acpi_get_pci_dev(video->device->handle);
 990         if (!dev)
 991                 return -ENODEV;
 992         pci_dev_put(dev);
 993
 994         /*
 995          * Since there is no HID, CID and so on for VGA driver, we have
 996          * to check well known required nodes.
 997          */
 998
 999         /* Does this device support video switching? */
1000         if (video->cap._DOS || video->cap._DOD) {
1001                 if (!video->cap._DOS) {
1002                         printk(KERN_WARNING FW_BUG
1003                                 "ACPI(%s) defines _DOD but not _DOS\n",
1004                                 acpi_device_bid(video->device));
1005                 }
1006                 video->flags.multihead = 1;
1007                 status = 0;
1008         }
1009
1010         /* Does this device support retrieving a video ROM? */
1011         if (video->cap._ROM) {
1012                 video->flags.rom = 1;
1013                 status = 0;
1014         }
1015
1016         /* Does this device support configuring which video device to POST? */
1017         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1018                 video->flags.post = 1;
1019                 status = 0;
1020         }
1021
1022         return status;
1023 }
1024
1025 /*
1026  * --------------------------------------------------------------------------
1027  *                               Driver Interface
1028  * --------------------------------------------------------------------------
1029  */
1030
1031 /* device interface */
1032 static struct acpi_video_device_attrib *
1033 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1034 {
1035         struct acpi_video_enumerated_device *ids;
1036         int i;
1037
1038         for (i = 0; i < video->attached_count; i++) {
1039                 ids = &video->attached_array[i];
1040                 if ((ids->value.int_val & 0xffff) == device_id)
1041                         return &ids->value.attrib;
1042         }
1043
1044         return NULL;
1045 }
1046
1047 static int
1048 acpi_video_get_device_type(struct acpi_video_bus *video,
1049                            unsigned long device_id)
1050 {
1051         struct acpi_video_enumerated_device *ids;
1052         int i;
1053
1054         for (i = 0; i < video->attached_count; i++) {
1055                 ids = &video->attached_array[i];
1056                 if ((ids->value.int_val & 0xffff) == device_id)
1057                         return ids->value.int_val;
1058         }
1059
1060         return 0;
1061 }
1062
1063 static int
1064 acpi_video_bus_get_one_device(struct acpi_device *device,
1065                               struct acpi_video_bus *video)
1066 {
1067         unsigned long long device_id;
1068         int status, device_type;
1069         struct acpi_video_device *data;
1070         struct acpi_video_device_attrib *attribute;
1071
1072         status =
1073             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1074         /* Some device omits _ADR, we skip them instead of fail */
1075         if (ACPI_FAILURE(status))
1076                 return 0;
1077
1078         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1079         if (!data)
1080                 return -ENOMEM;
1081
1082         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1083         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1084         device->driver_data = data;
1085
1086         data->device_id = device_id;
1087         data->video = video;
1088         data->dev = device;
1089         INIT_DELAYED_WORK(&data->switch_brightness_work,
1090                           acpi_video_switch_brightness);
1091
1092         attribute = acpi_video_get_device_attr(video, device_id);
1093
1094         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1095                 switch (attribute->display_type) {
1096                 case ACPI_VIDEO_DISPLAY_CRT:
1097                         data->flags.crt = 1;
1098                         break;
1099                 case ACPI_VIDEO_DISPLAY_TV:
1100                         data->flags.tvout = 1;
1101                         break;
1102                 case ACPI_VIDEO_DISPLAY_DVI:
1103                         data->flags.dvi = 1;
1104                         break;
1105                 case ACPI_VIDEO_DISPLAY_LCD:
1106                         data->flags.lcd = 1;
1107                         break;
1108                 default:
1109                         data->flags.unknown = 1;
1110                         break;
1111                 }
1112                 if (attribute->bios_can_detect)
1113                         data->flags.bios = 1;
1114         } else {
1115                 /* Check for legacy IDs */
1116                 device_type = acpi_video_get_device_type(video, device_id);
1117                 /* Ignore bits 16 and 18-20 */
1118                 switch (device_type & 0xffe2ffff) {
1119                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1120                         data->flags.crt = 1;
1121                         break;
1122                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1123                         data->flags.lcd = 1;
1124                         break;
1125                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1126                         data->flags.tvout = 1;
1127                         break;
1128                 default:
1129                         data->flags.unknown = 1;
1130                 }
1131         }
1132
1133         acpi_video_device_bind(video, data);
1134         acpi_video_device_find_cap(data);
1135
1136         mutex_lock(&video->device_list_lock);
1137         list_add_tail(&data->entry, &video->video_device_list);
1138         mutex_unlock(&video->device_list_lock);
1139
1140         return status;
1141 }
1142
1143 /*
1144  *  Arg:
1145  *      video   : video bus device
1146  *
1147  *  Return:
1148  *      none
1149  *
1150  *  Enumerate the video device list of the video bus,
1151  *  bind the ids with the corresponding video devices
1152  *  under the video bus.
1153  */
1154
1155 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1156 {
1157         struct acpi_video_device *dev;
1158
1159         mutex_lock(&video->device_list_lock);
1160
1161         list_for_each_entry(dev, &video->video_device_list, entry)
1162                 acpi_video_device_bind(video, dev);
1163
1164         mutex_unlock(&video->device_list_lock);
1165 }
1166
1167 /*
1168  *  Arg:
1169  *      video   : video bus device
1170  *      device  : video output device under the video
1171  *              bus
1172  *
1173  *  Return:
1174  *      none
1175  *
1176  *  Bind the ids with the corresponding video devices
1177  *  under the video bus.
1178  */
1179
1180 static void
1181 acpi_video_device_bind(struct acpi_video_bus *video,
1182                        struct acpi_video_device *device)
1183 {
1184         struct acpi_video_enumerated_device *ids;
1185         int i;
1186
1187         for (i = 0; i < video->attached_count; i++) {
1188                 ids = &video->attached_array[i];
1189                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1190                         ids->bind_info = device;
1191                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1192                 }
1193         }
1194 }
1195
1196 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1197 {
1198         struct acpi_video_bus *video = device->video;
1199         int i;
1200
1201         /*
1202          * If we have a broken _DOD or we have more than 8 output devices
1203          * under the graphics controller node that we can't proper deal with
1204          * in the operation region code currently, no need to test.
1205          */
1206         if (!video->attached_count || video->child_count > 8)
1207                 return true;
1208
1209         for (i = 0; i < video->attached_count; i++) {
1210                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1211                     (device->device_id & 0xfff))
1212                         return true;
1213         }
1214
1215         return false;
1216 }
1217
1218 /*
1219  *  Arg:
1220  *      video   : video bus device
1221  *
1222  *  Return:
1223  *      < 0     : error
1224  *
1225  *  Call _DOD to enumerate all devices attached to display adapter
1226  *
1227  */
1228
1229 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1230 {
1231         int status;
1232         int count;
1233         int i;
1234         struct acpi_video_enumerated_device *active_list;
1235         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1236         union acpi_object *dod = NULL;
1237         union acpi_object *obj;
1238
1239         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1240         if (!ACPI_SUCCESS(status)) {
1241                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1242                 return status;
1243         }
1244
1245         dod = buffer.pointer;
1246         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1247                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1248                 status = -EFAULT;
1249                 goto out;
1250         }
1251
1252         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1253                           dod->package.count));
1254
1255         active_list = kcalloc(1 + dod->package.count,
1256                               sizeof(struct acpi_video_enumerated_device),
1257                               GFP_KERNEL);
1258         if (!active_list) {
1259                 status = -ENOMEM;
1260                 goto out;
1261         }
1262
1263         count = 0;
1264         for (i = 0; i < dod->package.count; i++) {
1265                 obj = &dod->package.elements[i];
1266
1267                 if (obj->type != ACPI_TYPE_INTEGER) {
1268                         printk(KERN_ERR PREFIX
1269                                 "Invalid _DOD data in element %d\n", i);
1270                         continue;
1271                 }
1272
1273                 active_list[count].value.int_val = obj->integer.value;
1274                 active_list[count].bind_info = NULL;
1275                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1276                                   (int)obj->integer.value));
1277                 count++;
1278         }
1279
1280         kfree(video->attached_array);
1281
1282         video->attached_array = active_list;
1283         video->attached_count = count;
1284
1285 out:
1286         kfree(buffer.pointer);
1287         return status;
1288 }
1289
1290 static int
1291 acpi_video_get_next_level(struct acpi_video_device *device,
1292                           u32 level_current, u32 event)
1293 {
1294         int min, max, min_above, max_below, i, l, delta = 255;
1295         max = max_below = 0;
1296         min = min_above = 255;
1297         /* Find closest level to level_current */
1298         for (i = 2; i < device->brightness->count; i++) {
1299                 l = device->brightness->levels[i];
1300                 if (abs(l - level_current) < abs(delta)) {
1301                         delta = l - level_current;
1302                         if (!delta)
1303                                 break;
1304                 }
1305         }
1306         /* Ajust level_current to closest available level */
1307         level_current += delta;
1308         for (i = 2; i < device->brightness->count; i++) {
1309                 l = device->brightness->levels[i];
1310                 if (l < min)
1311                         min = l;
1312                 if (l > max)
1313                         max = l;
1314                 if (l < min_above && l > level_current)
1315                         min_above = l;
1316                 if (l > max_below && l < level_current)
1317                         max_below = l;
1318         }
1319
1320         switch (event) {
1321         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1322                 return (level_current < max) ? min_above : min;
1323         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1324                 return (level_current < max) ? min_above : max;
1325         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1326                 return (level_current > min) ? max_below : min;
1327         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1328         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1329                 return 0;
1330         default:
1331                 return level_current;
1332         }
1333 }
1334
1335 static void
1336 acpi_video_switch_brightness(struct work_struct *work)
1337 {
1338         struct acpi_video_device *device = container_of(to_delayed_work(work),
1339                              struct acpi_video_device, switch_brightness_work);
1340         unsigned long long level_current, level_next;
1341         int event = device->switch_brightness_event;
1342         int result = -EINVAL;
1343
1344         /* no warning message if acpi_backlight=vendor or a quirk is used */
1345         if (!device->backlight)
1346                 return;
1347
1348         if (!device->brightness)
1349                 goto out;
1350
1351         result = acpi_video_device_lcd_get_level_current(device,
1352                                                          &level_current,
1353                                                          false);
1354         if (result)
1355                 goto out;
1356
1357         level_next = acpi_video_get_next_level(device, level_current, event);
1358
1359         result = acpi_video_device_lcd_set_level(device, level_next);
1360
1361         if (!result)
1362                 backlight_force_update(device->backlight,
1363                                        BACKLIGHT_UPDATE_HOTKEY);
1364
1365 out:
1366         if (result)
1367                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1368 }
1369
1370 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1371                         void **edid)
1372 {
1373         struct acpi_video_bus *video;
1374         struct acpi_video_device *video_device;
1375         union acpi_object *buffer = NULL;
1376         acpi_status status;
1377         int i, length;
1378
1379         if (!device || !acpi_driver_data(device))
1380                 return -EINVAL;
1381
1382         video = acpi_driver_data(device);
1383
1384         for (i = 0; i < video->attached_count; i++) {
1385                 video_device = video->attached_array[i].bind_info;
1386                 length = 256;
1387
1388                 if (!video_device)
1389                         continue;
1390
1391                 if (!video_device->cap._DDC)
1392                         continue;
1393
1394                 if (type) {
1395                         switch (type) {
1396                         case ACPI_VIDEO_DISPLAY_CRT:
1397                                 if (!video_device->flags.crt)
1398                                         continue;
1399                                 break;
1400                         case ACPI_VIDEO_DISPLAY_TV:
1401                                 if (!video_device->flags.tvout)
1402                                         continue;
1403                                 break;
1404                         case ACPI_VIDEO_DISPLAY_DVI:
1405                                 if (!video_device->flags.dvi)
1406                                         continue;
1407                                 break;
1408                         case ACPI_VIDEO_DISPLAY_LCD:
1409                                 if (!video_device->flags.lcd)
1410                                         continue;
1411                                 break;
1412                         }
1413                 } else if (video_device->device_id != device_id) {
1414                         continue;
1415                 }
1416
1417                 status = acpi_video_device_EDID(video_device, &buffer, length);
1418
1419                 if (ACPI_FAILURE(status) || !buffer ||
1420                     buffer->type != ACPI_TYPE_BUFFER) {
1421                         length = 128;
1422                         status = acpi_video_device_EDID(video_device, &buffer,
1423                                                         length);
1424                         if (ACPI_FAILURE(status) || !buffer ||
1425                             buffer->type != ACPI_TYPE_BUFFER) {
1426                                 continue;
1427                         }
1428                 }
1429
1430                 *edid = buffer->buffer.pointer;
1431                 return length;
1432         }
1433
1434         return -ENODEV;
1435 }
1436 EXPORT_SYMBOL(acpi_video_get_edid);
1437
1438 static int
1439 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1440                            struct acpi_device *device)
1441 {
1442         int status = 0;
1443         struct acpi_device *dev;
1444
1445         /*
1446          * There are systems where video module known to work fine regardless
1447          * of broken _DOD and ignoring returned value here doesn't cause
1448          * any issues later.
1449          */
1450         acpi_video_device_enumerate(video);
1451
1452         list_for_each_entry(dev, &device->children, node) {
1453
1454                 status = acpi_video_bus_get_one_device(dev, video);
1455                 if (status) {
1456                         dev_err(&dev->dev, "Can't attach device\n");
1457                         break;
1458                 }
1459                 video->child_count++;
1460         }
1461         return status;
1462 }
1463
1464 /* acpi_video interface */
1465
1466 /*
1467  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1468  * preform any automatic brightness change on receiving a notification.
1469  */
1470 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1471 {
1472         return acpi_video_bus_DOS(video, 0,
1473                                   acpi_osi_is_win8() ? 1 : 0);
1474 }
1475
1476 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1477 {
1478         return acpi_video_bus_DOS(video, 0,
1479                                   acpi_osi_is_win8() ? 0 : 1);
1480 }
1481
1482 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1483 {
1484         struct acpi_video_bus *video = acpi_driver_data(device);
1485         struct input_dev *input;
1486         int keycode = 0;
1487
1488         if (!video || !video->input)
1489                 return;
1490
1491         input = video->input;
1492
1493         switch (event) {
1494         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1495                                          * most likely via hotkey. */
1496                 keycode = KEY_SWITCHVIDEOMODE;
1497                 break;
1498
1499         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1500                                          * connector. */
1501                 acpi_video_device_enumerate(video);
1502                 acpi_video_device_rebind(video);
1503                 keycode = KEY_SWITCHVIDEOMODE;
1504                 break;
1505
1506         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1507                 keycode = KEY_SWITCHVIDEOMODE;
1508                 break;
1509         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1510                 keycode = KEY_VIDEO_NEXT;
1511                 break;
1512         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1513                 keycode = KEY_VIDEO_PREV;
1514                 break;
1515
1516         default:
1517                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1518                                   "Unsupported event [0x%x]\n", event));
1519                 break;
1520         }
1521
1522         if (acpi_notifier_call_chain(device, event, 0))
1523                 /* Something vetoed the keypress. */
1524                 keycode = 0;
1525
1526         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1527                 input_report_key(input, keycode, 1);
1528                 input_sync(input);
1529                 input_report_key(input, keycode, 0);
1530                 input_sync(input);
1531         }
1532
1533         return;
1534 }
1535
1536 static void brightness_switch_event(struct acpi_video_device *video_device,
1537                                     u32 event)
1538 {
1539         if (!brightness_switch_enabled)
1540                 return;
1541
1542         video_device->switch_brightness_event = event;
1543         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1544 }
1545
1546 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1547 {
1548         struct acpi_video_device *video_device = data;
1549         struct acpi_device *device = NULL;
1550         struct acpi_video_bus *bus;
1551         struct input_dev *input;
1552         int keycode = 0;
1553
1554         if (!video_device)
1555                 return;
1556
1557         device = video_device->dev;
1558         bus = video_device->video;
1559         input = bus->input;
1560
1561         switch (event) {
1562         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1563                 brightness_switch_event(video_device, event);
1564                 keycode = KEY_BRIGHTNESS_CYCLE;
1565                 break;
1566         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1567                 brightness_switch_event(video_device, event);
1568                 keycode = KEY_BRIGHTNESSUP;
1569                 break;
1570         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1571                 brightness_switch_event(video_device, event);
1572                 keycode = KEY_BRIGHTNESSDOWN;
1573                 break;
1574         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1575                 brightness_switch_event(video_device, event);
1576                 keycode = KEY_BRIGHTNESS_ZERO;
1577                 break;
1578         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1579                 brightness_switch_event(video_device, event);
1580                 keycode = KEY_DISPLAY_OFF;
1581                 break;
1582         default:
1583                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1584                                   "Unsupported event [0x%x]\n", event));
1585                 break;
1586         }
1587
1588         acpi_notifier_call_chain(device, event, 0);
1589
1590         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1591                 input_report_key(input, keycode, 1);
1592                 input_sync(input);
1593                 input_report_key(input, keycode, 0);
1594                 input_sync(input);
1595         }
1596
1597         return;
1598 }
1599
1600 static int acpi_video_resume(struct notifier_block *nb,
1601                                 unsigned long val, void *ign)
1602 {
1603         struct acpi_video_bus *video;
1604         struct acpi_video_device *video_device;
1605         int i;
1606
1607         switch (val) {
1608         case PM_HIBERNATION_PREPARE:
1609         case PM_SUSPEND_PREPARE:
1610         case PM_RESTORE_PREPARE:
1611                 return NOTIFY_DONE;
1612         }
1613
1614         video = container_of(nb, struct acpi_video_bus, pm_nb);
1615
1616         dev_info(&video->device->dev, "Restoring backlight state\n");
1617
1618         for (i = 0; i < video->attached_count; i++) {
1619                 video_device = video->attached_array[i].bind_info;
1620                 if (video_device && video_device->brightness)
1621                         acpi_video_device_lcd_set_level(video_device,
1622                                         video_device->brightness->curr);
1623         }
1624
1625         return NOTIFY_OK;
1626 }
1627
1628 static acpi_status
1629 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1630                         void **return_value)
1631 {
1632         struct acpi_device *device = context;
1633         struct acpi_device *sibling;
1634         int result;
1635
1636         if (handle == device->handle)
1637                 return AE_CTRL_TERMINATE;
1638
1639         result = acpi_bus_get_device(handle, &sibling);
1640         if (result)
1641                 return AE_OK;
1642
1643         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1644                         return AE_ALREADY_EXISTS;
1645
1646         return AE_OK;
1647 }
1648
1649 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1650 {
1651         struct backlight_properties props;
1652         struct pci_dev *pdev;
1653         acpi_handle acpi_parent;
1654         struct device *parent = NULL;
1655         int result;
1656         static int count;
1657         char *name;
1658
1659         result = acpi_video_init_brightness(device);
1660         if (result)
1661                 return;
1662
1663         if (disable_backlight_sysfs_if > 0)
1664                 return;
1665
1666         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1667         if (!name)
1668                 return;
1669         count++;
1670
1671         acpi_get_parent(device->dev->handle, &acpi_parent);
1672
1673         pdev = acpi_get_pci_dev(acpi_parent);
1674         if (pdev) {
1675                 parent = &pdev->dev;
1676                 pci_dev_put(pdev);
1677         }
1678
1679         memset(&props, 0, sizeof(struct backlight_properties));
1680         props.type = BACKLIGHT_FIRMWARE;
1681         props.max_brightness = device->brightness->count - 3;
1682         device->backlight = backlight_device_register(name,
1683                                                       parent,
1684                                                       device,
1685                                                       &acpi_backlight_ops,
1686                                                       &props);
1687         kfree(name);
1688         if (IS_ERR(device->backlight)) {
1689                 device->backlight = NULL;
1690                 return;
1691         }
1692
1693         /*
1694          * Save current brightness level in case we have to restore it
1695          * before acpi_video_device_lcd_set_level() is called next time.
1696          */
1697         device->backlight->props.brightness =
1698                         acpi_video_get_brightness(device->backlight);
1699
1700         device->cooling_dev = thermal_cooling_device_register("LCD",
1701                                 device->dev, &video_cooling_ops);
1702         if (IS_ERR(device->cooling_dev)) {
1703                 /*
1704                  * Set cooling_dev to NULL so we don't crash trying to free it.
1705                  * Also, why the hell we are returning early and not attempt to
1706                  * register video output if cooling device registration failed?
1707                  * -- dtor
1708                  */
1709                 device->cooling_dev = NULL;
1710                 return;
1711         }
1712
1713         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1714                  device->cooling_dev->id);
1715         result = sysfs_create_link(&device->dev->dev.kobj,
1716                         &device->cooling_dev->device.kobj,
1717                         "thermal_cooling");
1718         if (result)
1719                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1720         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1721                         &device->dev->dev.kobj, "device");
1722         if (result)
1723                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1724 }
1725
1726 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1727 {
1728         struct acpi_video_device *dev;
1729         union acpi_object *levels;
1730
1731         mutex_lock(&video->device_list_lock);
1732         list_for_each_entry(dev, &video->video_device_list, entry) {
1733                 if (!acpi_video_device_lcd_query_levels(dev, &levels))
1734                         kfree(levels);
1735         }
1736         mutex_unlock(&video->device_list_lock);
1737 }
1738
1739 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1740 {
1741         /*
1742          * Do not create backlight device for video output
1743          * device that is not in the enumerated list.
1744          */
1745         if (!acpi_video_device_in_dod(dev)) {
1746                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1747                 return false;
1748         }
1749
1750         if (only_lcd)
1751                 return dev->flags.lcd;
1752         return true;
1753 }
1754
1755 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1756 {
1757         struct acpi_video_device *dev;
1758
1759         if (video->backlight_registered)
1760                 return 0;
1761
1762         acpi_video_run_bcl_for_osi(video);
1763
1764         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1765                 return 0;
1766
1767         mutex_lock(&video->device_list_lock);
1768         list_for_each_entry(dev, &video->video_device_list, entry) {
1769                 if (acpi_video_should_register_backlight(dev))
1770                         acpi_video_dev_register_backlight(dev);
1771         }
1772         mutex_unlock(&video->device_list_lock);
1773
1774         video->backlight_registered = true;
1775
1776         video->pm_nb.notifier_call = acpi_video_resume;
1777         video->pm_nb.priority = 0;
1778         return register_pm_notifier(&video->pm_nb);
1779 }
1780
1781 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1782 {
1783         if (device->backlight) {
1784                 backlight_device_unregister(device->backlight);
1785                 device->backlight = NULL;
1786         }
1787         if (device->brightness) {
1788                 kfree(device->brightness->levels);
1789                 kfree(device->brightness);
1790                 device->brightness = NULL;
1791         }
1792         if (device->cooling_dev) {
1793                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1794                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1795                 thermal_cooling_device_unregister(device->cooling_dev);
1796                 device->cooling_dev = NULL;
1797         }
1798 }
1799
1800 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1801 {
1802         struct acpi_video_device *dev;
1803         int error;
1804
1805         if (!video->backlight_registered)
1806                 return 0;
1807
1808         error = unregister_pm_notifier(&video->pm_nb);
1809
1810         mutex_lock(&video->device_list_lock);
1811         list_for_each_entry(dev, &video->video_device_list, entry)
1812                 acpi_video_dev_unregister_backlight(dev);
1813         mutex_unlock(&video->device_list_lock);
1814
1815         video->backlight_registered = false;
1816
1817         return error;
1818 }
1819
1820 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1821 {
1822         acpi_status status;
1823         struct acpi_device *adev = device->dev;
1824
1825         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1826                                              acpi_video_device_notify, device);
1827         if (ACPI_FAILURE(status))
1828                 dev_err(&adev->dev, "Error installing notify handler\n");
1829         else
1830                 device->flags.notify = 1;
1831 }
1832
1833 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1834 {
1835         struct input_dev *input;
1836         struct acpi_video_device *dev;
1837         int error;
1838
1839         video->input = input = input_allocate_device();
1840         if (!input) {
1841                 error = -ENOMEM;
1842                 goto out;
1843         }
1844
1845         error = acpi_video_bus_start_devices(video);
1846         if (error)
1847                 goto err_free_input;
1848
1849         snprintf(video->phys, sizeof(video->phys),
1850                         "%s/video/input0", acpi_device_hid(video->device));
1851
1852         input->name = acpi_device_name(video->device);
1853         input->phys = video->phys;
1854         input->id.bustype = BUS_HOST;
1855         input->id.product = 0x06;
1856         input->dev.parent = &video->device->dev;
1857         input->evbit[0] = BIT(EV_KEY);
1858         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1859         set_bit(KEY_VIDEO_NEXT, input->keybit);
1860         set_bit(KEY_VIDEO_PREV, input->keybit);
1861         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1862         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1863         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1864         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1865         set_bit(KEY_DISPLAY_OFF, input->keybit);
1866
1867         error = input_register_device(input);
1868         if (error)
1869                 goto err_stop_dev;
1870
1871         mutex_lock(&video->device_list_lock);
1872         list_for_each_entry(dev, &video->video_device_list, entry)
1873                 acpi_video_dev_add_notify_handler(dev);
1874         mutex_unlock(&video->device_list_lock);
1875
1876         return 0;
1877
1878 err_stop_dev:
1879         acpi_video_bus_stop_devices(video);
1880 err_free_input:
1881         input_free_device(input);
1882         video->input = NULL;
1883 out:
1884         return error;
1885 }
1886
1887 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1888 {
1889         if (dev->flags.notify) {
1890                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1891                                            acpi_video_device_notify);
1892                 dev->flags.notify = 0;
1893         }
1894 }
1895
1896 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1897 {
1898         struct acpi_video_device *dev;
1899
1900         mutex_lock(&video->device_list_lock);
1901         list_for_each_entry(dev, &video->video_device_list, entry)
1902                 acpi_video_dev_remove_notify_handler(dev);
1903         mutex_unlock(&video->device_list_lock);
1904
1905         acpi_video_bus_stop_devices(video);
1906         input_unregister_device(video->input);
1907         video->input = NULL;
1908 }
1909
1910 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1911 {
1912         struct acpi_video_device *dev, *next;
1913
1914         mutex_lock(&video->device_list_lock);
1915         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1916                 list_del(&dev->entry);
1917                 kfree(dev);
1918         }
1919         mutex_unlock(&video->device_list_lock);
1920
1921         return 0;
1922 }
1923
1924 static int instance;
1925
1926 static int acpi_video_bus_add(struct acpi_device *device)
1927 {
1928         struct acpi_video_bus *video;
1929         int error;
1930         acpi_status status;
1931
1932         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1933                                 device->parent->handle, 1,
1934                                 acpi_video_bus_match, NULL,
1935                                 device, NULL);
1936         if (status == AE_ALREADY_EXISTS) {
1937                 printk(KERN_WARNING FW_BUG
1938                         "Duplicate ACPI video bus devices for the"
1939                         " same VGA controller, please try module "
1940                         "parameter \"video.allow_duplicates=1\""
1941                         "if the current driver doesn't work.\n");
1942                 if (!allow_duplicates)
1943                         return -ENODEV;
1944         }
1945
1946         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1947         if (!video)
1948                 return -ENOMEM;
1949
1950         /* a hack to fix the duplicate name "VID" problem on T61 */
1951         if (!strcmp(device->pnp.bus_id, "VID")) {
1952                 if (instance)
1953                         device->pnp.bus_id[3] = '0' + instance;
1954                 instance++;
1955         }
1956         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1957         if (!strcmp(device->pnp.bus_id, "VGA")) {
1958                 if (instance)
1959                         device->pnp.bus_id[3] = '0' + instance;
1960                 instance++;
1961         }
1962
1963         video->device = device;
1964         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1965         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1966         device->driver_data = video;
1967
1968         acpi_video_bus_find_cap(video);
1969         error = acpi_video_bus_check(video);
1970         if (error)
1971                 goto err_free_video;
1972
1973         mutex_init(&video->device_list_lock);
1974         INIT_LIST_HEAD(&video->video_device_list);
1975
1976         error = acpi_video_bus_get_devices(video, device);
1977         if (error)
1978                 goto err_put_video;
1979
1980         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1981                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1982                video->flags.multihead ? "yes" : "no",
1983                video->flags.rom ? "yes" : "no",
1984                video->flags.post ? "yes" : "no");
1985         mutex_lock(&video_list_lock);
1986         list_add_tail(&video->entry, &video_bus_head);
1987         mutex_unlock(&video_list_lock);
1988
1989         acpi_video_bus_register_backlight(video);
1990         acpi_video_bus_add_notify_handler(video);
1991
1992         return 0;
1993
1994 err_put_video:
1995         acpi_video_bus_put_devices(video);
1996         kfree(video->attached_array);
1997 err_free_video:
1998         kfree(video);
1999         device->driver_data = NULL;
2000
2001         return error;
2002 }
2003
2004 static int acpi_video_bus_remove(struct acpi_device *device)
2005 {
2006         struct acpi_video_bus *video = NULL;
2007
2008
2009         if (!device || !acpi_driver_data(device))
2010                 return -EINVAL;
2011
2012         video = acpi_driver_data(device);
2013
2014         acpi_video_bus_remove_notify_handler(video);
2015         acpi_video_bus_unregister_backlight(video);
2016         acpi_video_bus_put_devices(video);
2017
2018         mutex_lock(&video_list_lock);
2019         list_del(&video->entry);
2020         mutex_unlock(&video_list_lock);
2021
2022         kfree(video->attached_array);
2023         kfree(video);
2024
2025         return 0;
2026 }
2027
2028 static int __init is_i740(struct pci_dev *dev)
2029 {
2030         if (dev->device == 0x00D1)
2031                 return 1;
2032         if (dev->device == 0x7000)
2033                 return 1;
2034         return 0;
2035 }
2036
2037 static int __init intel_opregion_present(void)
2038 {
2039         int opregion = 0;
2040         struct pci_dev *dev = NULL;
2041         u32 address;
2042
2043         for_each_pci_dev(dev) {
2044                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2045                         continue;
2046                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2047                         continue;
2048                 /* We don't want to poke around undefined i740 registers */
2049                 if (is_i740(dev))
2050                         continue;
2051                 pci_read_config_dword(dev, 0xfc, &address);
2052                 if (!address)
2053                         continue;
2054                 opregion = 1;
2055         }
2056         return opregion;
2057 }
2058
2059 int acpi_video_register(void)
2060 {
2061         int ret = 0;
2062
2063         mutex_lock(&register_count_mutex);
2064         if (register_count) {
2065                 /*
2066                  * if the function of acpi_video_register is already called,
2067                  * don't register the acpi_vide_bus again and return no error.
2068                  */
2069                 goto leave;
2070         }
2071
2072         dmi_check_system(video_dmi_table);
2073
2074         ret = acpi_bus_register_driver(&acpi_video_bus);
2075         if (ret)
2076                 goto leave;
2077
2078         /*
2079          * When the acpi_video_bus is loaded successfully, increase
2080          * the counter reference.
2081          */
2082         register_count = 1;
2083
2084 leave:
2085         mutex_unlock(&register_count_mutex);
2086         return ret;
2087 }
2088 EXPORT_SYMBOL(acpi_video_register);
2089
2090 void acpi_video_unregister(void)
2091 {
2092         mutex_lock(&register_count_mutex);
2093         if (register_count) {
2094                 acpi_bus_unregister_driver(&acpi_video_bus);
2095                 register_count = 0;
2096         }
2097         mutex_unlock(&register_count_mutex);
2098 }
2099 EXPORT_SYMBOL(acpi_video_unregister);
2100
2101 void acpi_video_unregister_backlight(void)
2102 {
2103         struct acpi_video_bus *video;
2104
2105         mutex_lock(&register_count_mutex);
2106         if (register_count) {
2107                 mutex_lock(&video_list_lock);
2108                 list_for_each_entry(video, &video_bus_head, entry)
2109                         acpi_video_bus_unregister_backlight(video);
2110                 mutex_unlock(&video_list_lock);
2111         }
2112         mutex_unlock(&register_count_mutex);
2113 }
2114
2115 bool acpi_video_handles_brightness_key_presses(void)
2116 {
2117         bool have_video_busses;
2118
2119         mutex_lock(&video_list_lock);
2120         have_video_busses = !list_empty(&video_bus_head);
2121         mutex_unlock(&video_list_lock);
2122
2123         return have_video_busses &&
2124                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2125 }
2126 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2127
2128 /*
2129  * This is kind of nasty. Hardware using Intel chipsets may require
2130  * the video opregion code to be run first in order to initialise
2131  * state before any ACPI video calls are made. To handle this we defer
2132  * registration of the video class until the opregion code has run.
2133  */
2134
2135 static int __init acpi_video_init(void)
2136 {
2137         /*
2138          * Let the module load even if ACPI is disabled (e.g. due to
2139          * a broken BIOS) so that i915.ko can still be loaded on such
2140          * old systems without an AcpiOpRegion.
2141          *
2142          * acpi_video_register() will report -ENODEV later as well due
2143          * to acpi_disabled when i915.ko tries to register itself afterwards.
2144          */
2145         if (acpi_disabled)
2146                 return 0;
2147
2148         if (intel_opregion_present())
2149                 return 0;
2150
2151         return acpi_video_register();
2152 }
2153
2154 static void __exit acpi_video_exit(void)
2155 {
2156         acpi_video_detect_exit();
2157         acpi_video_unregister();
2158
2159         return;
2160 }
2161
2162 module_init(acpi_video_init);
2163 module_exit(acpi_video_exit);