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 <linux/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
  47 #define MAX_NAME_LEN    20
  48
  49 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  50 ACPI_MODULE_NAME("video");
  51
  52 MODULE_AUTHOR("Bruno Ducrot");
  53 MODULE_DESCRIPTION("ACPI Video Driver");
  54 MODULE_LICENSE("GPL");
  55
  56 static bool brightness_switch_enabled = true;
  57 module_param(brightness_switch_enabled, bool, 0644);
  58
  59 /*
  60  * By default, we don't allow duplicate ACPI video bus devices
  61  * under the same VGA controller
  62  */
  63 static bool allow_duplicates;
  64 module_param(allow_duplicates, bool, 0644);
  65
  66 static int disable_backlight_sysfs_if = -1;
  67 module_param(disable_backlight_sysfs_if, int, 0444);
  68
  69 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  70 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  71 static int report_key_events = -1;
  72 module_param(report_key_events, int, 0644);
  73 MODULE_PARM_DESC(report_key_events,
  74         "0: none, 1: output changes, 2: brightness changes, 3: all");
  75
  76 /*
  77  * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
  78  * assumed even if not actually set.
  79  */
  80 static bool device_id_scheme = false;
  81 module_param(device_id_scheme, bool, 0444);
  82
  83 static int only_lcd = -1;
  84 module_param(only_lcd, int, 0444);
  85
  86 static int register_count;
  87 static DEFINE_MUTEX(register_count_mutex);
  88 static DEFINE_MUTEX(video_list_lock);
  89 static LIST_HEAD(video_bus_head);
  90 static int acpi_video_bus_add(struct acpi_device *device);
  91 static int acpi_video_bus_remove(struct acpi_device *device);
  92 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  93 void acpi_video_detect_exit(void);
  94
  95 /*
  96  * Indices in the _BCL method response: the first two items are special,
  97  * the rest are all supported levels.
  98  *
  99  * See page 575 of the ACPI spec 3.0
 100  */
 101 enum acpi_video_level_idx {
 102         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
 103         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
 104         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
 105 };
 106
 107 static const struct acpi_device_id video_device_ids[] = {
 108         {ACPI_VIDEO_HID, 0},
 109         {"", 0},
 110 };
 111 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 112
 113 static struct acpi_driver acpi_video_bus = {
 114         .name = "video",
 115         .class = ACPI_VIDEO_CLASS,
 116         .ids = video_device_ids,
 117         .ops = {
 118                 .add = acpi_video_bus_add,
 119                 .remove = acpi_video_bus_remove,
 120                 .notify = acpi_video_bus_notify,
 121                 },
 122 };
 123
 124 struct acpi_video_bus_flags {
 125         u8 multihead:1;         /* can switch video heads */
 126         u8 rom:1;               /* can retrieve a video rom */
 127         u8 post:1;              /* can configure the head to */
 128         u8 reserved:5;
 129 };
 130
 131 struct acpi_video_bus_cap {
 132         u8 _DOS:1;              /* Enable/Disable output switching */
 133         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 134         u8 _ROM:1;              /* Get ROM Data */
 135         u8 _GPD:1;              /* Get POST Device */
 136         u8 _SPD:1;              /* Set POST Device */
 137         u8 _VPO:1;              /* Video POST Options */
 138         u8 reserved:2;
 139 };
 140
 141 struct acpi_video_device_attrib {
 142         u32 display_index:4;    /* A zero-based instance of the Display */
 143         u32 display_port_attachment:4;  /* This field differentiates the display type */
 144         u32 display_type:4;     /* Describe the specific type in use */
 145         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 146         u32 bios_can_detect:1;  /* BIOS can detect the device */
 147         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 148                                    the VGA device. */
 149         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 150         u32 reserved:10;        /* Must be 0 */
 151
 152         /*
 153          * The device ID might not actually follow the scheme described by this
 154          * struct acpi_video_device_attrib. If it does, then this bit
 155          * device_id_scheme is set; otherwise, other fields should be ignored.
 156          *
 157          * (but also see the global flag device_id_scheme)
 158          */
 159         u32 device_id_scheme:1;
 160 };
 161
 162 struct acpi_video_enumerated_device {
 163         union {
 164                 u32 int_val;
 165                 struct acpi_video_device_attrib attrib;
 166         } value;
 167         struct acpi_video_device *bind_info;
 168 };
 169
 170 struct acpi_video_bus {
 171         struct acpi_device *device;
 172         bool backlight_registered;
 173         u8 dos_setting;
 174         struct acpi_video_enumerated_device *attached_array;
 175         u8 attached_count;
 176         u8 child_count;
 177         struct acpi_video_bus_cap cap;
 178         struct acpi_video_bus_flags flags;
 179         struct list_head video_device_list;
 180         struct mutex device_list_lock;  /* protects video_device_list */
 181         struct list_head entry;
 182         struct input_dev *input;
 183         char phys[32];  /* for input device */
 184         struct notifier_block pm_nb;
 185 };
 186
 187 struct acpi_video_device_flags {
 188         u8 crt:1;
 189         u8 lcd:1;
 190         u8 tvout:1;
 191         u8 dvi:1;
 192         u8 bios:1;
 193         u8 unknown:1;
 194         u8 notify:1;
 195         u8 reserved:1;
 196 };
 197
 198 struct acpi_video_device_cap {
 199         u8 _ADR:1;              /* Return the unique ID */
 200         u8 _BCL:1;              /* Query list of brightness control levels supported */
 201         u8 _BCM:1;              /* Set the brightness level */
 202         u8 _BQC:1;              /* Get current brightness level */
 203         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 204         u8 _DDC:1;              /* Return the EDID for this device */
 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 = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 245                 if (vd->brightness->levels[i] == cur_level)
 246                         return i - ACPI_VIDEO_FIRST_LEVEL;
 247         }
 248         return 0;
 249 }
 250
 251 static int acpi_video_set_brightness(struct backlight_device *bd)
 252 {
 253         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 254         struct acpi_video_device *vd = bl_get_data(bd);
 255
 256         cancel_delayed_work(&vd->switch_brightness_work);
 257         return acpi_video_device_lcd_set_level(vd,
 258                                 vd->brightness->levels[request_level]);
 259 }
 260
 261 static const struct backlight_ops acpi_backlight_ops = {
 262         .get_brightness = acpi_video_get_brightness,
 263         .update_status  = acpi_video_set_brightness,
 264 };
 265
 266 /* thermal cooling device callbacks */
 267 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 268                                unsigned long *state)
 269 {
 270         struct acpi_device *device = cooling_dev->devdata;
 271         struct acpi_video_device *video = acpi_driver_data(device);
 272
 273         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 274         return 0;
 275 }
 276
 277 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 278                                unsigned long *state)
 279 {
 280         struct acpi_device *device = cooling_dev->devdata;
 281         struct acpi_video_device *video = acpi_driver_data(device);
 282         unsigned long long level;
 283         int offset;
 284
 285         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 286                 return -EINVAL;
 287         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 288              offset++)
 289                 if (level == video->brightness->levels[offset]) {
 290                         *state = video->brightness->count - offset - 1;
 291                         return 0;
 292                 }
 293
 294         return -EINVAL;
 295 }
 296
 297 static int
 298 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 299 {
 300         struct acpi_device *device = cooling_dev->devdata;
 301         struct acpi_video_device *video = acpi_driver_data(device);
 302         int level;
 303
 304         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 305                 return -EINVAL;
 306
 307         state = video->brightness->count - state;
 308         level = video->brightness->levels[state - 1];
 309         return acpi_video_device_lcd_set_level(video, level);
 310 }
 311
 312 static const struct thermal_cooling_device_ops video_cooling_ops = {
 313         .get_max_state = video_get_max_state,
 314         .get_cur_state = video_get_cur_state,
 315         .set_cur_state = video_set_cur_state,
 316 };
 317
 318 /*
 319  * --------------------------------------------------------------------------
 320  *                             Video Management
 321  * --------------------------------------------------------------------------
 322  */
 323
 324 static int
 325 acpi_video_device_lcd_query_levels(acpi_handle handle,
 326                                    union acpi_object **levels)
 327 {
 328         int status;
 329         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 330         union acpi_object *obj;
 331
 332
 333         *levels = NULL;
 334
 335         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 336         if (!ACPI_SUCCESS(status))
 337                 return status;
 338         obj = (union acpi_object *)buffer.pointer;
 339         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 340                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 341                 status = -EFAULT;
 342                 goto err;
 343         }
 344
 345         *levels = obj;
 346
 347         return 0;
 348
 349 err:
 350         kfree(buffer.pointer);
 351
 352         return status;
 353 }
 354
 355 static int
 356 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 357 {
 358         int status;
 359         int state;
 360
 361         status = acpi_execute_simple_method(device->dev->handle,
 362                                             "_BCM", level);
 363         if (ACPI_FAILURE(status)) {
 364                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 365                 return -EIO;
 366         }
 367
 368         device->brightness->curr = level;
 369         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 370              state++)
 371                 if (level == device->brightness->levels[state]) {
 372                         if (device->backlight)
 373                                 device->backlight->props.brightness =
 374                                         state - ACPI_VIDEO_FIRST_LEVEL;
 375                         return 0;
 376                 }
 377
 378         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 379         return -EINVAL;
 380 }
 381
 382 /*
 383  * For some buggy _BQC methods, we need to add a constant value to
 384  * the _BQC return value to get the actual current brightness level
 385  */
 386
 387 static int bqc_offset_aml_bug_workaround;
 388 static int video_set_bqc_offset(const struct dmi_system_id *d)
 389 {
 390         bqc_offset_aml_bug_workaround = 9;
 391         return 0;
 392 }
 393
 394 static int video_disable_backlight_sysfs_if(
 395         const struct dmi_system_id *d)
 396 {
 397         if (disable_backlight_sysfs_if == -1)
 398                 disable_backlight_sysfs_if = 1;
 399         return 0;
 400 }
 401
 402 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 403 {
 404         device_id_scheme = true;
 405         return 0;
 406 }
 407
 408 static int video_enable_only_lcd(const struct dmi_system_id *d)
 409 {
 410         only_lcd = true;
 411         return 0;
 412 }
 413
 414 static int video_set_report_key_events(const struct dmi_system_id *id)
 415 {
 416         if (report_key_events == -1)
 417                 report_key_events = (uintptr_t)id->driver_data;
 418         return 0;
 419 }
 420
 421 static const struct dmi_system_id video_dmi_table[] = {
 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          * Some machines have a broken acpi-video interface for brightness
 468          * control, but still need an acpi_video_device_lcd_set_level() call
 469          * on resume to turn the backlight power on.  We Enable backlight
 470          * control on these systems, but do not register a backlight sysfs
 471          * as brightness control does not work.
 472          */
 473         {
 474          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 475          .callback = video_disable_backlight_sysfs_if,
 476          .ident = "Toshiba Portege R700",
 477          .matches = {
 478                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 479                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 480                 },
 481         },
 482         {
 483          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 484          .callback = video_disable_backlight_sysfs_if,
 485          .ident = "Toshiba Portege R830",
 486          .matches = {
 487                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 488                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 489                 },
 490         },
 491         {
 492          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 493          .callback = video_disable_backlight_sysfs_if,
 494          .ident = "Toshiba Satellite R830",
 495          .matches = {
 496                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 497                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 498                 },
 499         },
 500         /*
 501          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 502          * but the IDs actually follow the Device ID Scheme.
 503          */
 504         {
 505          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 506          .callback = video_set_device_id_scheme,
 507          .ident = "ESPRIMO Mobile M9410",
 508          .matches = {
 509                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 510                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 511                 },
 512         },
 513         /*
 514          * Some machines have multiple video output devices, but only the one
 515          * that is the type of LCD can do the backlight control so we should not
 516          * register backlight interface for other video output devices.
 517          */
 518         {
 519          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 520          .callback = video_enable_only_lcd,
 521          .ident = "ESPRIMO Mobile M9410",
 522          .matches = {
 523                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 524                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 525                 },
 526         },
 527         /*
 528          * Some machines report wrong key events on the acpi-bus, suppress
 529          * key event reporting on these.  Note this is only intended to work
 530          * around events which are plain wrong. In some cases we get double
 531          * events, in this case acpi-video is considered the canonical source
 532          * and the events from the other source should be filtered. E.g.
 533          * by calling acpi_video_handles_brightness_key_presses() from the
 534          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 535          */
 536         {
 537          .callback = video_set_report_key_events,
 538          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 539          .ident = "Dell Vostro V131",
 540          .matches = {
 541                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 542                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 543                 },
 544         },
 545         {}
 546 };
 547
 548 static unsigned long long
 549 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 550                               unsigned long long bqc_value)
 551 {
 552         unsigned long long level;
 553
 554         if (device->brightness->flags._BQC_use_index) {
 555                 /*
 556                  * _BQC returns an index that doesn't account for the first 2
 557                  * items with special meaning (see enum acpi_video_level_idx),
 558                  * so we need to compensate for that by offsetting ourselves
 559                  */
 560                 if (device->brightness->flags._BCL_reversed)
 561                         bqc_value = device->brightness->count -
 562                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 563
 564                 level = device->brightness->levels[bqc_value +
 565                                                    ACPI_VIDEO_FIRST_LEVEL];
 566         } else {
 567                 level = bqc_value;
 568         }
 569
 570         level += bqc_offset_aml_bug_workaround;
 571
 572         return level;
 573 }
 574
 575 static int
 576 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 577                                         unsigned long long *level, bool raw)
 578 {
 579         acpi_status status = AE_OK;
 580         int i;
 581
 582         if (device->cap._BQC || device->cap._BCQ) {
 583                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 584
 585                 status = acpi_evaluate_integer(device->dev->handle, buf,
 586                                                 NULL, level);
 587                 if (ACPI_SUCCESS(status)) {
 588                         if (raw) {
 589                                 /*
 590                                  * Caller has indicated he wants the raw
 591                                  * value returned by _BQC, so don't furtherly
 592                                  * mess with the value.
 593                                  */
 594                                 return 0;
 595                         }
 596
 597                         *level = acpi_video_bqc_value_to_level(device, *level);
 598
 599                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 600                              i < device->brightness->count; i++)
 601                                 if (device->brightness->levels[i] == *level) {
 602                                         device->brightness->curr = *level;
 603                                         return 0;
 604                                 }
 605                         /*
 606                          * BQC returned an invalid level.
 607                          * Stop using it.
 608                          */
 609                         ACPI_WARNING((AE_INFO,
 610                                       "%s returned an invalid level",
 611                                       buf));
 612                         device->cap._BQC = device->cap._BCQ = 0;
 613                 } else {
 614                         /*
 615                          * Fixme:
 616                          * should we return an error or ignore this failure?
 617                          * dev->brightness->curr is a cached value which stores
 618                          * the correct current backlight level in most cases.
 619                          * ACPI video backlight still works w/ buggy _BQC.
 620                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 621                          */
 622                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 623                         device->cap._BQC = device->cap._BCQ = 0;
 624                 }
 625         }
 626
 627         *level = device->brightness->curr;
 628         return 0;
 629 }
 630
 631 static int
 632 acpi_video_device_EDID(struct acpi_video_device *device,
 633                        union acpi_object **edid, ssize_t length)
 634 {
 635         int status;
 636         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 637         union acpi_object *obj;
 638         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 639         struct acpi_object_list args = { 1, &arg0 };
 640
 641
 642         *edid = NULL;
 643
 644         if (!device)
 645                 return -ENODEV;
 646         if (length == 128)
 647                 arg0.integer.value = 1;
 648         else if (length == 256)
 649                 arg0.integer.value = 2;
 650         else
 651                 return -EINVAL;
 652
 653         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 654         if (ACPI_FAILURE(status))
 655                 return -ENODEV;
 656
 657         obj = buffer.pointer;
 658
 659         if (obj && obj->type == ACPI_TYPE_BUFFER)
 660                 *edid = obj;
 661         else {
 662                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 663                 status = -EFAULT;
 664                 kfree(obj);
 665         }
 666
 667         return status;
 668 }
 669
 670 /* bus */
 671
 672 /*
 673  *  Arg:
 674  *      video           : video bus device pointer
 675  *      bios_flag       :
 676  *              0.      The system BIOS should NOT automatically switch(toggle)
 677  *                      the active display output.
 678  *              1.      The system BIOS should automatically switch (toggle) the
 679  *                      active display output. No switch event.
 680  *              2.      The _DGS value should be locked.
 681  *              3.      The system BIOS should not automatically switch (toggle) the
 682  *                      active display output, but instead generate the display switch
 683  *                      event notify code.
 684  *      lcd_flag        :
 685  *              0.      The system BIOS should automatically control the brightness level
 686  *                      of the LCD when the power changes from AC to DC
 687  *              1.      The system BIOS should NOT automatically control the brightness
 688  *                      level of the LCD when the power changes from AC to DC.
 689  *  Return Value:
 690  *              -EINVAL wrong arg.
 691  */
 692
 693 static int
 694 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 695 {
 696         acpi_status status;
 697
 698         if (!video->cap._DOS)
 699                 return 0;
 700
 701         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 702                 return -EINVAL;
 703         video->dos_setting = (lcd_flag << 2) | bios_flag;
 704         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 705                                             (lcd_flag << 2) | bios_flag);
 706         if (ACPI_FAILURE(status))
 707                 return -EIO;
 708
 709         return 0;
 710 }
 711
 712 /*
 713  * Simple comparison function used to sort backlight levels.
 714  */
 715
 716 static int
 717 acpi_video_cmp_level(const void *a, const void *b)
 718 {
 719         return *(int *)a - *(int *)b;
 720 }
 721
 722 /*
 723  * Decides if _BQC/_BCQ for this system is usable
 724  *
 725  * We do this by changing the level first and then read out the current
 726  * brightness level, if the value does not match, find out if it is using
 727  * index. If not, clear the _BQC/_BCQ capability.
 728  */
 729 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 730                                 int max_level, int current_level)
 731 {
 732         struct acpi_video_device_brightness *br = device->brightness;
 733         int result;
 734         unsigned long long level;
 735         int test_level;
 736
 737         /* don't mess with existing known broken systems */
 738         if (bqc_offset_aml_bug_workaround)
 739                 return 0;
 740
 741         /*
 742          * Some systems always report current brightness level as maximum
 743          * through _BQC, we need to test another value for them. However,
 744          * there is a subtlety:
 745          *
 746          * If the _BCL package ordering is descending, the first level
 747          * (br->levels[2]) is likely to be 0, and if the number of levels
 748          * matches the number of steps, we might confuse a returned level to
 749          * mean the index.
 750          *
 751          * For example:
 752          *
 753          *     current_level = max_level = 100
 754          *     test_level = 0
 755          *     returned level = 100
 756          *
 757          * In this case 100 means the level, not the index, and _BCM failed.
 758          * Still, if the _BCL package ordering is descending, the index of
 759          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 760          *
 761          * This causes all _BQC calls to return bogus values causing weird
 762          * behavior from the user's perspective.  For example:
 763          *
 764          * xbacklight -set 10; xbacklight -set 20;
 765          *
 766          * would flash to 90% and then slowly down to the desired level (20).
 767          *
 768          * The solution is simple; test anything other than the first level
 769          * (e.g. 1).
 770          */
 771         test_level = current_level == max_level
 772                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 773                 : max_level;
 774
 775         result = acpi_video_device_lcd_set_level(device, test_level);
 776         if (result)
 777                 return result;
 778
 779         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 780         if (result)
 781                 return result;
 782
 783         if (level != test_level) {
 784                 /* buggy _BQC found, need to find out if it uses index */
 785                 if (level < br->count) {
 786                         if (br->flags._BCL_reversed)
 787                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 788                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 789                                 br->flags._BQC_use_index = 1;
 790                 }
 791
 792                 if (!br->flags._BQC_use_index)
 793                         device->cap._BQC = device->cap._BCQ = 0;
 794         }
 795
 796         return 0;
 797 }
 798
 799 int acpi_video_get_levels(struct acpi_device *device,
 800                           struct acpi_video_device_brightness **dev_br,
 801                           int *pmax_level)
 802 {
 803         union acpi_object *obj = NULL;
 804         int i, max_level = 0, count = 0, level_ac_battery = 0;
 805         union acpi_object *o;
 806         struct acpi_video_device_brightness *br = NULL;
 807         int result = 0;
 808         u32 value;
 809
 810         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device->handle,
 811                                                                 &obj))) {
 812                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 813                                                 "LCD brightness level\n"));
 814                 result = -ENODEV;
 815                 goto out;
 816         }
 817
 818         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 819                 result = -EINVAL;
 820                 goto out;
 821         }
 822
 823         br = kzalloc(sizeof(*br), GFP_KERNEL);
 824         if (!br) {
 825                 printk(KERN_ERR "can't allocate memory\n");
 826                 result = -ENOMEM;
 827                 goto out;
 828         }
 829
 830         /*
 831          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 832          * in order to account for buggy BIOS which don't export the first two
 833          * special levels (see below)
 834          */
 835         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 836                                    sizeof(*br->levels),
 837                                    GFP_KERNEL);
 838         if (!br->levels) {
 839                 result = -ENOMEM;
 840                 goto out_free;
 841         }
 842
 843         for (i = 0; i < obj->package.count; i++) {
 844                 o = (union acpi_object *)&obj->package.elements[i];
 845                 if (o->type != ACPI_TYPE_INTEGER) {
 846                         printk(KERN_ERR PREFIX "Invalid data\n");
 847                         continue;
 848                 }
 849                 value = (u32) o->integer.value;
 850                 /* Skip duplicate entries */
 851                 if (count > ACPI_VIDEO_FIRST_LEVEL
 852                     && br->levels[count - 1] == value)
 853                         continue;
 854
 855                 br->levels[count] = value;
 856
 857                 if (br->levels[count] > max_level)
 858                         max_level = br->levels[count];
 859                 count++;
 860         }
 861
 862         /*
 863          * some buggy BIOS don't export the levels
 864          * when machine is on AC/Battery in _BCL package.
 865          * In this case, the first two elements in _BCL packages
 866          * are also supported brightness levels that OS should take care of.
 867          */
 868         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 869                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 870                         level_ac_battery++;
 871                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 872                         level_ac_battery++;
 873         }
 874
 875         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 876                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 877                 br->flags._BCL_no_ac_battery_levels = 1;
 878                 for (i = (count - 1 + level_ac_battery);
 879                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 880                         br->levels[i] = br->levels[i - level_ac_battery];
 881                 count += level_ac_battery;
 882         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 883                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 884
 885         /* Check if the _BCL package is in a reversed order */
 886         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 887                 br->flags._BCL_reversed = 1;
 888                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 889                      count - ACPI_VIDEO_FIRST_LEVEL,
 890                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 891                      acpi_video_cmp_level, NULL);
 892         } else if (max_level != br->levels[count - 1])
 893                 ACPI_ERROR((AE_INFO,
 894                             "Found unordered _BCL package"));
 895
 896         br->count = count;
 897         *dev_br = br;
 898         if (pmax_level)
 899                 *pmax_level = max_level;
 900
 901 out:
 902         kfree(obj);
 903         return result;
 904 out_free:
 905         kfree(br);
 906         goto out;
 907 }
 908 EXPORT_SYMBOL(acpi_video_get_levels);
 909
 910 /*
 911  *  Arg:
 912  *      device  : video output device (LCD, CRT, ..)
 913  *
 914  *  Return Value:
 915  *      Maximum brightness level
 916  *
 917  *  Allocate and initialize device->brightness.
 918  */
 919
 920 static int
 921 acpi_video_init_brightness(struct acpi_video_device *device)
 922 {
 923         int i, max_level = 0;
 924         unsigned long long level, level_old;
 925         struct acpi_video_device_brightness *br = NULL;
 926         int result = -EINVAL;
 927
 928         result = acpi_video_get_levels(device->dev, &br, &max_level);
 929         if (result)
 930                 return result;
 931         device->brightness = br;
 932
 933         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 934         br->curr = level = max_level;
 935
 936         if (!device->cap._BQC)
 937                 goto set_level;
 938
 939         result = acpi_video_device_lcd_get_level_current(device,
 940                                                          &level_old, true);
 941         if (result)
 942                 goto out_free_levels;
 943
 944         result = acpi_video_bqc_quirk(device, max_level, level_old);
 945         if (result)
 946                 goto out_free_levels;
 947         /*
 948          * cap._BQC may get cleared due to _BQC is found to be broken
 949          * in acpi_video_bqc_quirk, so check again here.
 950          */
 951         if (!device->cap._BQC)
 952                 goto set_level;
 953
 954         level = acpi_video_bqc_value_to_level(device, level_old);
 955         /*
 956          * On some buggy laptops, _BQC returns an uninitialized
 957          * value when invoked for the first time, i.e.
 958          * level_old is invalid (no matter whether it's a level
 959          * or an index). Set the backlight to max_level in this case.
 960          */
 961         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 962                 if (level == br->levels[i])
 963                         break;
 964         if (i == br->count || !level)
 965                 level = max_level;
 966
 967 set_level:
 968         result = acpi_video_device_lcd_set_level(device, level);
 969         if (result)
 970                 goto out_free_levels;
 971
 972         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 973                           "found %d brightness levels\n",
 974                           br->count - ACPI_VIDEO_FIRST_LEVEL));
 975         return 0;
 976
 977 out_free_levels:
 978         kfree(br->levels);
 979         kfree(br);
 980         device->brightness = NULL;
 981         return result;
 982 }
 983
 984 /*
 985  *  Arg:
 986  *      device  : video output device (LCD, CRT, ..)
 987  *
 988  *  Return Value:
 989  *      None
 990  *
 991  *  Find out all required AML methods defined under the output
 992  *  device.
 993  */
 994
 995 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 996 {
 997         if (acpi_has_method(device->dev->handle, "_ADR"))
 998                 device->cap._ADR = 1;
 999         if (acpi_has_method(device->dev->handle, "_BCL"))
1000                 device->cap._BCL = 1;
1001         if (acpi_has_method(device->dev->handle, "_BCM"))
1002                 device->cap._BCM = 1;
1003         if (acpi_has_method(device->dev->handle, "_BQC")) {
1004                 device->cap._BQC = 1;
1005         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1006                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
1007                 device->cap._BCQ = 1;
1008         }
1009
1010         if (acpi_has_method(device->dev->handle, "_DDC"))
1011                 device->cap._DDC = 1;
1012 }
1013
1014 /*
1015  *  Arg:
1016  *      device  : video output device (VGA)
1017  *
1018  *  Return Value:
1019  *      None
1020  *
1021  *  Find out all required AML methods defined under the video bus device.
1022  */
1023
1024 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1025 {
1026         if (acpi_has_method(video->device->handle, "_DOS"))
1027                 video->cap._DOS = 1;
1028         if (acpi_has_method(video->device->handle, "_DOD"))
1029                 video->cap._DOD = 1;
1030         if (acpi_has_method(video->device->handle, "_ROM"))
1031                 video->cap._ROM = 1;
1032         if (acpi_has_method(video->device->handle, "_GPD"))
1033                 video->cap._GPD = 1;
1034         if (acpi_has_method(video->device->handle, "_SPD"))
1035                 video->cap._SPD = 1;
1036         if (acpi_has_method(video->device->handle, "_VPO"))
1037                 video->cap._VPO = 1;
1038 }
1039
1040 /*
1041  * Check whether the video bus device has required AML method to
1042  * support the desired features
1043  */
1044
1045 static int acpi_video_bus_check(struct acpi_video_bus *video)
1046 {
1047         acpi_status status = -ENOENT;
1048         struct pci_dev *dev;
1049
1050         if (!video)
1051                 return -EINVAL;
1052
1053         dev = acpi_get_pci_dev(video->device->handle);
1054         if (!dev)
1055                 return -ENODEV;
1056         pci_dev_put(dev);
1057
1058         /*
1059          * Since there is no HID, CID and so on for VGA driver, we have
1060          * to check well known required nodes.
1061          */
1062
1063         /* Does this device support video switching? */
1064         if (video->cap._DOS || video->cap._DOD) {
1065                 if (!video->cap._DOS) {
1066                         printk(KERN_WARNING FW_BUG
1067                                 "ACPI(%s) defines _DOD but not _DOS\n",
1068                                 acpi_device_bid(video->device));
1069                 }
1070                 video->flags.multihead = 1;
1071                 status = 0;
1072         }
1073
1074         /* Does this device support retrieving a video ROM? */
1075         if (video->cap._ROM) {
1076                 video->flags.rom = 1;
1077                 status = 0;
1078         }
1079
1080         /* Does this device support configuring which video device to POST? */
1081         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1082                 video->flags.post = 1;
1083                 status = 0;
1084         }
1085
1086         return status;
1087 }
1088
1089 /*
1090  * --------------------------------------------------------------------------
1091  *                               Driver Interface
1092  * --------------------------------------------------------------------------
1093  */
1094
1095 /* device interface */
1096 static struct acpi_video_device_attrib *
1097 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1098 {
1099         struct acpi_video_enumerated_device *ids;
1100         int i;
1101
1102         for (i = 0; i < video->attached_count; i++) {
1103                 ids = &video->attached_array[i];
1104                 if ((ids->value.int_val & 0xffff) == device_id)
1105                         return &ids->value.attrib;
1106         }
1107
1108         return NULL;
1109 }
1110
1111 static int
1112 acpi_video_get_device_type(struct acpi_video_bus *video,
1113                            unsigned long device_id)
1114 {
1115         struct acpi_video_enumerated_device *ids;
1116         int i;
1117
1118         for (i = 0; i < video->attached_count; i++) {
1119                 ids = &video->attached_array[i];
1120                 if ((ids->value.int_val & 0xffff) == device_id)
1121                         return ids->value.int_val;
1122         }
1123
1124         return 0;
1125 }
1126
1127 static int
1128 acpi_video_bus_get_one_device(struct acpi_device *device,
1129                               struct acpi_video_bus *video)
1130 {
1131         unsigned long long device_id;
1132         int status, device_type;
1133         struct acpi_video_device *data;
1134         struct acpi_video_device_attrib *attribute;
1135
1136         status =
1137             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1138         /* Some device omits _ADR, we skip them instead of fail */
1139         if (ACPI_FAILURE(status))
1140                 return 0;
1141
1142         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1143         if (!data)
1144                 return -ENOMEM;
1145
1146         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1147         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1148         device->driver_data = data;
1149
1150         data->device_id = device_id;
1151         data->video = video;
1152         data->dev = device;
1153         INIT_DELAYED_WORK(&data->switch_brightness_work,
1154                           acpi_video_switch_brightness);
1155
1156         attribute = acpi_video_get_device_attr(video, device_id);
1157
1158         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1159                 switch (attribute->display_type) {
1160                 case ACPI_VIDEO_DISPLAY_CRT:
1161                         data->flags.crt = 1;
1162                         break;
1163                 case ACPI_VIDEO_DISPLAY_TV:
1164                         data->flags.tvout = 1;
1165                         break;
1166                 case ACPI_VIDEO_DISPLAY_DVI:
1167                         data->flags.dvi = 1;
1168                         break;
1169                 case ACPI_VIDEO_DISPLAY_LCD:
1170                         data->flags.lcd = 1;
1171                         break;
1172                 default:
1173                         data->flags.unknown = 1;
1174                         break;
1175                 }
1176                 if (attribute->bios_can_detect)
1177                         data->flags.bios = 1;
1178         } else {
1179                 /* Check for legacy IDs */
1180                 device_type = acpi_video_get_device_type(video, device_id);
1181                 /* Ignore bits 16 and 18-20 */
1182                 switch (device_type & 0xffe2ffff) {
1183                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1184                         data->flags.crt = 1;
1185                         break;
1186                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1187                         data->flags.lcd = 1;
1188                         break;
1189                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1190                         data->flags.tvout = 1;
1191                         break;
1192                 default:
1193                         data->flags.unknown = 1;
1194                 }
1195         }
1196
1197         acpi_video_device_bind(video, data);
1198         acpi_video_device_find_cap(data);
1199
1200         mutex_lock(&video->device_list_lock);
1201         list_add_tail(&data->entry, &video->video_device_list);
1202         mutex_unlock(&video->device_list_lock);
1203
1204         return status;
1205 }
1206
1207 /*
1208  *  Arg:
1209  *      video   : video bus device
1210  *
1211  *  Return:
1212  *      none
1213  *
1214  *  Enumerate the video device list of the video bus,
1215  *  bind the ids with the corresponding video devices
1216  *  under the video bus.
1217  */
1218
1219 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1220 {
1221         struct acpi_video_device *dev;
1222
1223         mutex_lock(&video->device_list_lock);
1224
1225         list_for_each_entry(dev, &video->video_device_list, entry)
1226                 acpi_video_device_bind(video, dev);
1227
1228         mutex_unlock(&video->device_list_lock);
1229 }
1230
1231 /*
1232  *  Arg:
1233  *      video   : video bus device
1234  *      device  : video output device under the video
1235  *              bus
1236  *
1237  *  Return:
1238  *      none
1239  *
1240  *  Bind the ids with the corresponding video devices
1241  *  under the video bus.
1242  */
1243
1244 static void
1245 acpi_video_device_bind(struct acpi_video_bus *video,
1246                        struct acpi_video_device *device)
1247 {
1248         struct acpi_video_enumerated_device *ids;
1249         int i;
1250
1251         for (i = 0; i < video->attached_count; i++) {
1252                 ids = &video->attached_array[i];
1253                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1254                         ids->bind_info = device;
1255                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1256                 }
1257         }
1258 }
1259
1260 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1261 {
1262         struct acpi_video_bus *video = device->video;
1263         int i;
1264
1265         /*
1266          * If we have a broken _DOD or we have more than 8 output devices
1267          * under the graphics controller node that we can't proper deal with
1268          * in the operation region code currently, no need to test.
1269          */
1270         if (!video->attached_count || video->child_count > 8)
1271                 return true;
1272
1273         for (i = 0; i < video->attached_count; i++) {
1274                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1275                     (device->device_id & 0xfff))
1276                         return true;
1277         }
1278
1279         return false;
1280 }
1281
1282 /*
1283  *  Arg:
1284  *      video   : video bus device
1285  *
1286  *  Return:
1287  *      < 0     : error
1288  *
1289  *  Call _DOD to enumerate all devices attached to display adapter
1290  *
1291  */
1292
1293 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1294 {
1295         int status;
1296         int count;
1297         int i;
1298         struct acpi_video_enumerated_device *active_list;
1299         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1300         union acpi_object *dod = NULL;
1301         union acpi_object *obj;
1302
1303         if (!video->cap._DOD)
1304                 return AE_NOT_EXIST;
1305
1306         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1307         if (!ACPI_SUCCESS(status)) {
1308                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1309                 return status;
1310         }
1311
1312         dod = buffer.pointer;
1313         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1314                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1315                 status = -EFAULT;
1316                 goto out;
1317         }
1318
1319         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1320                           dod->package.count));
1321
1322         active_list = kcalloc(1 + dod->package.count,
1323                               sizeof(struct acpi_video_enumerated_device),
1324                               GFP_KERNEL);
1325         if (!active_list) {
1326                 status = -ENOMEM;
1327                 goto out;
1328         }
1329
1330         count = 0;
1331         for (i = 0; i < dod->package.count; i++) {
1332                 obj = &dod->package.elements[i];
1333
1334                 if (obj->type != ACPI_TYPE_INTEGER) {
1335                         printk(KERN_ERR PREFIX
1336                                 "Invalid _DOD data in element %d\n", i);
1337                         continue;
1338                 }
1339
1340                 active_list[count].value.int_val = obj->integer.value;
1341                 active_list[count].bind_info = NULL;
1342                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1343                                   (int)obj->integer.value));
1344                 count++;
1345         }
1346
1347         kfree(video->attached_array);
1348
1349         video->attached_array = active_list;
1350         video->attached_count = count;
1351
1352 out:
1353         kfree(buffer.pointer);
1354         return status;
1355 }
1356
1357 static int
1358 acpi_video_get_next_level(struct acpi_video_device *device,
1359                           u32 level_current, u32 event)
1360 {
1361         int min, max, min_above, max_below, i, l, delta = 255;
1362         max = max_below = 0;
1363         min = min_above = 255;
1364         /* Find closest level to level_current */
1365         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1366                 l = device->brightness->levels[i];
1367                 if (abs(l - level_current) < abs(delta)) {
1368                         delta = l - level_current;
1369                         if (!delta)
1370                                 break;
1371                 }
1372         }
1373         /* Ajust level_current to closest available level */
1374         level_current += delta;
1375         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1376                 l = device->brightness->levels[i];
1377                 if (l < min)
1378                         min = l;
1379                 if (l > max)
1380                         max = l;
1381                 if (l < min_above && l > level_current)
1382                         min_above = l;
1383                 if (l > max_below && l < level_current)
1384                         max_below = l;
1385         }
1386
1387         switch (event) {
1388         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1389                 return (level_current < max) ? min_above : min;
1390         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1391                 return (level_current < max) ? min_above : max;
1392         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1393                 return (level_current > min) ? max_below : min;
1394         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1395         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1396                 return 0;
1397         default:
1398                 return level_current;
1399         }
1400 }
1401
1402 static void
1403 acpi_video_switch_brightness(struct work_struct *work)
1404 {
1405         struct acpi_video_device *device = container_of(to_delayed_work(work),
1406                              struct acpi_video_device, switch_brightness_work);
1407         unsigned long long level_current, level_next;
1408         int event = device->switch_brightness_event;
1409         int result = -EINVAL;
1410
1411         /* no warning message if acpi_backlight=vendor or a quirk is used */
1412         if (!device->backlight)
1413                 return;
1414
1415         if (!device->brightness)
1416                 goto out;
1417
1418         result = acpi_video_device_lcd_get_level_current(device,
1419                                                          &level_current,
1420                                                          false);
1421         if (result)
1422                 goto out;
1423
1424         level_next = acpi_video_get_next_level(device, level_current, event);
1425
1426         result = acpi_video_device_lcd_set_level(device, level_next);
1427
1428         if (!result)
1429                 backlight_force_update(device->backlight,
1430                                        BACKLIGHT_UPDATE_HOTKEY);
1431
1432 out:
1433         if (result)
1434                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1435 }
1436
1437 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1438                         void **edid)
1439 {
1440         struct acpi_video_bus *video;
1441         struct acpi_video_device *video_device;
1442         union acpi_object *buffer = NULL;
1443         acpi_status status;
1444         int i, length;
1445
1446         if (!device || !acpi_driver_data(device))
1447                 return -EINVAL;
1448
1449         video = acpi_driver_data(device);
1450
1451         for (i = 0; i < video->attached_count; i++) {
1452                 video_device = video->attached_array[i].bind_info;
1453                 length = 256;
1454
1455                 if (!video_device)
1456                         continue;
1457
1458                 if (!video_device->cap._DDC)
1459                         continue;
1460
1461                 if (type) {
1462                         switch (type) {
1463                         case ACPI_VIDEO_DISPLAY_CRT:
1464                                 if (!video_device->flags.crt)
1465                                         continue;
1466                                 break;
1467                         case ACPI_VIDEO_DISPLAY_TV:
1468                                 if (!video_device->flags.tvout)
1469                                         continue;
1470                                 break;
1471                         case ACPI_VIDEO_DISPLAY_DVI:
1472                                 if (!video_device->flags.dvi)
1473                                         continue;
1474                                 break;
1475                         case ACPI_VIDEO_DISPLAY_LCD:
1476                                 if (!video_device->flags.lcd)
1477                                         continue;
1478                                 break;
1479                         }
1480                 } else if (video_device->device_id != device_id) {
1481                         continue;
1482                 }
1483
1484                 status = acpi_video_device_EDID(video_device, &buffer, length);
1485
1486                 if (ACPI_FAILURE(status) || !buffer ||
1487                     buffer->type != ACPI_TYPE_BUFFER) {
1488                         length = 128;
1489                         status = acpi_video_device_EDID(video_device, &buffer,
1490                                                         length);
1491                         if (ACPI_FAILURE(status) || !buffer ||
1492                             buffer->type != ACPI_TYPE_BUFFER) {
1493                                 continue;
1494                         }
1495                 }
1496
1497                 *edid = buffer->buffer.pointer;
1498                 return length;
1499         }
1500
1501         return -ENODEV;
1502 }
1503 EXPORT_SYMBOL(acpi_video_get_edid);
1504
1505 static int
1506 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1507                            struct acpi_device *device)
1508 {
1509         int status = 0;
1510         struct acpi_device *dev;
1511
1512         /*
1513          * There are systems where video module known to work fine regardless
1514          * of broken _DOD and ignoring returned value here doesn't cause
1515          * any issues later.
1516          */
1517         acpi_video_device_enumerate(video);
1518
1519         list_for_each_entry(dev, &device->children, node) {
1520
1521                 status = acpi_video_bus_get_one_device(dev, video);
1522                 if (status) {
1523                         dev_err(&dev->dev, "Can't attach device\n");
1524                         break;
1525                 }
1526                 video->child_count++;
1527         }
1528         return status;
1529 }
1530
1531 /* acpi_video interface */
1532
1533 /*
1534  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1535  * preform any automatic brightness change on receiving a notification.
1536  */
1537 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1538 {
1539         return acpi_video_bus_DOS(video, 0,
1540                                   acpi_osi_is_win8() ? 1 : 0);
1541 }
1542
1543 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1544 {
1545         return acpi_video_bus_DOS(video, 0,
1546                                   acpi_osi_is_win8() ? 0 : 1);
1547 }
1548
1549 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1550 {
1551         struct acpi_video_bus *video = acpi_driver_data(device);
1552         struct input_dev *input;
1553         int keycode = 0;
1554
1555         if (!video || !video->input)
1556                 return;
1557
1558         input = video->input;
1559
1560         switch (event) {
1561         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1562                                          * most likely via hotkey. */
1563                 keycode = KEY_SWITCHVIDEOMODE;
1564                 break;
1565
1566         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1567                                          * connector. */
1568                 acpi_video_device_enumerate(video);
1569                 acpi_video_device_rebind(video);
1570                 keycode = KEY_SWITCHVIDEOMODE;
1571                 break;
1572
1573         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1574                 keycode = KEY_SWITCHVIDEOMODE;
1575                 break;
1576         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1577                 keycode = KEY_VIDEO_NEXT;
1578                 break;
1579         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1580                 keycode = KEY_VIDEO_PREV;
1581                 break;
1582
1583         default:
1584                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1585                                   "Unsupported event [0x%x]\n", event));
1586                 break;
1587         }
1588
1589         if (acpi_notifier_call_chain(device, event, 0))
1590                 /* Something vetoed the keypress. */
1591                 keycode = 0;
1592
1593         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1594                 input_report_key(input, keycode, 1);
1595                 input_sync(input);
1596                 input_report_key(input, keycode, 0);
1597                 input_sync(input);
1598         }
1599
1600         return;
1601 }
1602
1603 static void brightness_switch_event(struct acpi_video_device *video_device,
1604                                     u32 event)
1605 {
1606         if (!brightness_switch_enabled)
1607                 return;
1608
1609         video_device->switch_brightness_event = event;
1610         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1611 }
1612
1613 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1614 {
1615         struct acpi_video_device *video_device = data;
1616         struct acpi_device *device = NULL;
1617         struct acpi_video_bus *bus;
1618         struct input_dev *input;
1619         int keycode = 0;
1620
1621         if (!video_device)
1622                 return;
1623
1624         device = video_device->dev;
1625         bus = video_device->video;
1626         input = bus->input;
1627
1628         switch (event) {
1629         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1630                 brightness_switch_event(video_device, event);
1631                 keycode = KEY_BRIGHTNESS_CYCLE;
1632                 break;
1633         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1634                 brightness_switch_event(video_device, event);
1635                 keycode = KEY_BRIGHTNESSUP;
1636                 break;
1637         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1638                 brightness_switch_event(video_device, event);
1639                 keycode = KEY_BRIGHTNESSDOWN;
1640                 break;
1641         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1642                 brightness_switch_event(video_device, event);
1643                 keycode = KEY_BRIGHTNESS_ZERO;
1644                 break;
1645         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1646                 brightness_switch_event(video_device, event);
1647                 keycode = KEY_DISPLAY_OFF;
1648                 break;
1649         default:
1650                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1651                                   "Unsupported event [0x%x]\n", event));
1652                 break;
1653         }
1654
1655         acpi_notifier_call_chain(device, event, 0);
1656
1657         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1658                 input_report_key(input, keycode, 1);
1659                 input_sync(input);
1660                 input_report_key(input, keycode, 0);
1661                 input_sync(input);
1662         }
1663
1664         return;
1665 }
1666
1667 static int acpi_video_resume(struct notifier_block *nb,
1668                                 unsigned long val, void *ign)
1669 {
1670         struct acpi_video_bus *video;
1671         struct acpi_video_device *video_device;
1672         int i;
1673
1674         switch (val) {
1675         case PM_HIBERNATION_PREPARE:
1676         case PM_SUSPEND_PREPARE:
1677         case PM_RESTORE_PREPARE:
1678                 return NOTIFY_DONE;
1679         }
1680
1681         video = container_of(nb, struct acpi_video_bus, pm_nb);
1682
1683         dev_info(&video->device->dev, "Restoring backlight state\n");
1684
1685         for (i = 0; i < video->attached_count; i++) {
1686                 video_device = video->attached_array[i].bind_info;
1687                 if (video_device && video_device->brightness)
1688                         acpi_video_device_lcd_set_level(video_device,
1689                                         video_device->brightness->curr);
1690         }
1691
1692         return NOTIFY_OK;
1693 }
1694
1695 static acpi_status
1696 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1697                         void **return_value)
1698 {
1699         struct acpi_device *device = context;
1700         struct acpi_device *sibling;
1701         int result;
1702
1703         if (handle == device->handle)
1704                 return AE_CTRL_TERMINATE;
1705
1706         result = acpi_bus_get_device(handle, &sibling);
1707         if (result)
1708                 return AE_OK;
1709
1710         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1711                         return AE_ALREADY_EXISTS;
1712
1713         return AE_OK;
1714 }
1715
1716 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1717 {
1718         struct backlight_properties props;
1719         struct pci_dev *pdev;
1720         acpi_handle acpi_parent;
1721         struct device *parent = NULL;
1722         int result;
1723         static int count;
1724         char *name;
1725
1726         result = acpi_video_init_brightness(device);
1727         if (result)
1728                 return;
1729
1730         if (disable_backlight_sysfs_if > 0)
1731                 return;
1732
1733         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1734         if (!name)
1735                 return;
1736         count++;
1737
1738         acpi_get_parent(device->dev->handle, &acpi_parent);
1739
1740         pdev = acpi_get_pci_dev(acpi_parent);
1741         if (pdev) {
1742                 parent = &pdev->dev;
1743                 pci_dev_put(pdev);
1744         }
1745
1746         memset(&props, 0, sizeof(struct backlight_properties));
1747         props.type = BACKLIGHT_FIRMWARE;
1748         props.max_brightness =
1749                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1750         device->backlight = backlight_device_register(name,
1751                                                       parent,
1752                                                       device,
1753                                                       &acpi_backlight_ops,
1754                                                       &props);
1755         kfree(name);
1756         if (IS_ERR(device->backlight)) {
1757                 device->backlight = NULL;
1758                 return;
1759         }
1760
1761         /*
1762          * Save current brightness level in case we have to restore it
1763          * before acpi_video_device_lcd_set_level() is called next time.
1764          */
1765         device->backlight->props.brightness =
1766                         acpi_video_get_brightness(device->backlight);
1767
1768         device->cooling_dev = thermal_cooling_device_register("LCD",
1769                                 device->dev, &video_cooling_ops);
1770         if (IS_ERR(device->cooling_dev)) {
1771                 /*
1772                  * Set cooling_dev to NULL so we don't crash trying to free it.
1773                  * Also, why the hell we are returning early and not attempt to
1774                  * register video output if cooling device registration failed?
1775                  * -- dtor
1776                  */
1777                 device->cooling_dev = NULL;
1778                 return;
1779         }
1780
1781         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1782                  device->cooling_dev->id);
1783         result = sysfs_create_link(&device->dev->dev.kobj,
1784                         &device->cooling_dev->device.kobj,
1785                         "thermal_cooling");
1786         if (result)
1787                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1788         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1789                         &device->dev->dev.kobj, "device");
1790         if (result)
1791                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1792 }
1793
1794 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1795 {
1796         struct acpi_video_device *dev;
1797         union acpi_object *levels;
1798
1799         mutex_lock(&video->device_list_lock);
1800         list_for_each_entry(dev, &video->video_device_list, entry) {
1801                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1802                         kfree(levels);
1803         }
1804         mutex_unlock(&video->device_list_lock);
1805 }
1806
1807 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1808 {
1809         /*
1810          * Do not create backlight device for video output
1811          * device that is not in the enumerated list.
1812          */
1813         if (!acpi_video_device_in_dod(dev)) {
1814                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1815                 return false;
1816         }
1817
1818         if (only_lcd)
1819                 return dev->flags.lcd;
1820         return true;
1821 }
1822
1823 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1824 {
1825         struct acpi_video_device *dev;
1826
1827         if (video->backlight_registered)
1828                 return 0;
1829
1830         acpi_video_run_bcl_for_osi(video);
1831
1832         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1833                 return 0;
1834
1835         mutex_lock(&video->device_list_lock);
1836         list_for_each_entry(dev, &video->video_device_list, entry) {
1837                 if (acpi_video_should_register_backlight(dev))
1838                         acpi_video_dev_register_backlight(dev);
1839         }
1840         mutex_unlock(&video->device_list_lock);
1841
1842         video->backlight_registered = true;
1843
1844         video->pm_nb.notifier_call = acpi_video_resume;
1845         video->pm_nb.priority = 0;
1846         return register_pm_notifier(&video->pm_nb);
1847 }
1848
1849 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1850 {
1851         if (device->backlight) {
1852                 backlight_device_unregister(device->backlight);
1853                 device->backlight = NULL;
1854         }
1855         if (device->brightness) {
1856                 kfree(device->brightness->levels);
1857                 kfree(device->brightness);
1858                 device->brightness = NULL;
1859         }
1860         if (device->cooling_dev) {
1861                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1862                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1863                 thermal_cooling_device_unregister(device->cooling_dev);
1864                 device->cooling_dev = NULL;
1865         }
1866 }
1867
1868 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1869 {
1870         struct acpi_video_device *dev;
1871         int error;
1872
1873         if (!video->backlight_registered)
1874                 return 0;
1875
1876         error = unregister_pm_notifier(&video->pm_nb);
1877
1878         mutex_lock(&video->device_list_lock);
1879         list_for_each_entry(dev, &video->video_device_list, entry)
1880                 acpi_video_dev_unregister_backlight(dev);
1881         mutex_unlock(&video->device_list_lock);
1882
1883         video->backlight_registered = false;
1884
1885         return error;
1886 }
1887
1888 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1889 {
1890         acpi_status status;
1891         struct acpi_device *adev = device->dev;
1892
1893         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1894                                              acpi_video_device_notify, device);
1895         if (ACPI_FAILURE(status))
1896                 dev_err(&adev->dev, "Error installing notify handler\n");
1897         else
1898                 device->flags.notify = 1;
1899 }
1900
1901 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1902 {
1903         struct input_dev *input;
1904         struct acpi_video_device *dev;
1905         int error;
1906
1907         video->input = input = input_allocate_device();
1908         if (!input) {
1909                 error = -ENOMEM;
1910                 goto out;
1911         }
1912
1913         error = acpi_video_bus_start_devices(video);
1914         if (error)
1915                 goto err_free_input;
1916
1917         snprintf(video->phys, sizeof(video->phys),
1918                         "%s/video/input0", acpi_device_hid(video->device));
1919
1920         input->name = acpi_device_name(video->device);
1921         input->phys = video->phys;
1922         input->id.bustype = BUS_HOST;
1923         input->id.product = 0x06;
1924         input->dev.parent = &video->device->dev;
1925         input->evbit[0] = BIT(EV_KEY);
1926         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1927         set_bit(KEY_VIDEO_NEXT, input->keybit);
1928         set_bit(KEY_VIDEO_PREV, input->keybit);
1929         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1930         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1931         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1932         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1933         set_bit(KEY_DISPLAY_OFF, input->keybit);
1934
1935         error = input_register_device(input);
1936         if (error)
1937                 goto err_stop_dev;
1938
1939         mutex_lock(&video->device_list_lock);
1940         list_for_each_entry(dev, &video->video_device_list, entry)
1941                 acpi_video_dev_add_notify_handler(dev);
1942         mutex_unlock(&video->device_list_lock);
1943
1944         return 0;
1945
1946 err_stop_dev:
1947         acpi_video_bus_stop_devices(video);
1948 err_free_input:
1949         input_free_device(input);
1950         video->input = NULL;
1951 out:
1952         return error;
1953 }
1954
1955 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1956 {
1957         if (dev->flags.notify) {
1958                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1959                                            acpi_video_device_notify);
1960                 dev->flags.notify = 0;
1961         }
1962 }
1963
1964 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1965 {
1966         struct acpi_video_device *dev;
1967
1968         mutex_lock(&video->device_list_lock);
1969         list_for_each_entry(dev, &video->video_device_list, entry)
1970                 acpi_video_dev_remove_notify_handler(dev);
1971         mutex_unlock(&video->device_list_lock);
1972
1973         acpi_video_bus_stop_devices(video);
1974         input_unregister_device(video->input);
1975         video->input = NULL;
1976 }
1977
1978 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1979 {
1980         struct acpi_video_device *dev, *next;
1981
1982         mutex_lock(&video->device_list_lock);
1983         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1984                 list_del(&dev->entry);
1985                 kfree(dev);
1986         }
1987         mutex_unlock(&video->device_list_lock);
1988
1989         return 0;
1990 }
1991
1992 static int instance;
1993
1994 static int acpi_video_bus_add(struct acpi_device *device)
1995 {
1996         struct acpi_video_bus *video;
1997         int error;
1998         acpi_status status;
1999
2000         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2001                                 device->parent->handle, 1,
2002                                 acpi_video_bus_match, NULL,
2003                                 device, NULL);
2004         if (status == AE_ALREADY_EXISTS) {
2005                 printk(KERN_WARNING FW_BUG
2006                         "Duplicate ACPI video bus devices for the"
2007                         " same VGA controller, please try module "
2008                         "parameter \"video.allow_duplicates=1\""
2009                         "if the current driver doesn't work.\n");
2010                 if (!allow_duplicates)
2011                         return -ENODEV;
2012         }
2013
2014         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2015         if (!video)
2016                 return -ENOMEM;
2017
2018         /* a hack to fix the duplicate name "VID" problem on T61 */
2019         if (!strcmp(device->pnp.bus_id, "VID")) {
2020                 if (instance)
2021                         device->pnp.bus_id[3] = '0' + instance;
2022                 instance++;
2023         }
2024         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2025         if (!strcmp(device->pnp.bus_id, "VGA")) {
2026                 if (instance)
2027                         device->pnp.bus_id[3] = '0' + instance;
2028                 instance++;
2029         }
2030
2031         video->device = device;
2032         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2033         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2034         device->driver_data = video;
2035
2036         acpi_video_bus_find_cap(video);
2037         error = acpi_video_bus_check(video);
2038         if (error)
2039                 goto err_free_video;
2040
2041         mutex_init(&video->device_list_lock);
2042         INIT_LIST_HEAD(&video->video_device_list);
2043
2044         error = acpi_video_bus_get_devices(video, device);
2045         if (error)
2046                 goto err_put_video;
2047
2048         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2049                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2050                video->flags.multihead ? "yes" : "no",
2051                video->flags.rom ? "yes" : "no",
2052                video->flags.post ? "yes" : "no");
2053         mutex_lock(&video_list_lock);
2054         list_add_tail(&video->entry, &video_bus_head);
2055         mutex_unlock(&video_list_lock);
2056
2057         acpi_video_bus_register_backlight(video);
2058         acpi_video_bus_add_notify_handler(video);
2059
2060         return 0;
2061
2062 err_put_video:
2063         acpi_video_bus_put_devices(video);
2064         kfree(video->attached_array);
2065 err_free_video:
2066         kfree(video);
2067         device->driver_data = NULL;
2068
2069         return error;
2070 }
2071
2072 static int acpi_video_bus_remove(struct acpi_device *device)
2073 {
2074         struct acpi_video_bus *video = NULL;
2075
2076
2077         if (!device || !acpi_driver_data(device))
2078                 return -EINVAL;
2079
2080         video = acpi_driver_data(device);
2081
2082         acpi_video_bus_remove_notify_handler(video);
2083         acpi_video_bus_unregister_backlight(video);
2084         acpi_video_bus_put_devices(video);
2085
2086         mutex_lock(&video_list_lock);
2087         list_del(&video->entry);
2088         mutex_unlock(&video_list_lock);
2089
2090         kfree(video->attached_array);
2091         kfree(video);
2092
2093         return 0;
2094 }
2095
2096 static int __init is_i740(struct pci_dev *dev)
2097 {
2098         if (dev->device == 0x00D1)
2099                 return 1;
2100         if (dev->device == 0x7000)
2101                 return 1;
2102         return 0;
2103 }
2104
2105 static int __init intel_opregion_present(void)
2106 {
2107         int opregion = 0;
2108         struct pci_dev *dev = NULL;
2109         u32 address;
2110
2111         for_each_pci_dev(dev) {
2112                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2113                         continue;
2114                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2115                         continue;
2116                 /* We don't want to poke around undefined i740 registers */
2117                 if (is_i740(dev))
2118                         continue;
2119                 pci_read_config_dword(dev, 0xfc, &address);
2120                 if (!address)
2121                         continue;
2122                 opregion = 1;
2123         }
2124         return opregion;
2125 }
2126
2127 static bool dmi_is_desktop(void)
2128 {
2129         const char *chassis_type;
2130
2131         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2132         if (!chassis_type)
2133                 return false;
2134
2135         if (!strcmp(chassis_type, "3") || /*  3: Desktop */
2136             !strcmp(chassis_type, "4") || /*  4: Low Profile Desktop */
2137             !strcmp(chassis_type, "5") || /*  5: Pizza Box */
2138             !strcmp(chassis_type, "6") || /*  6: Mini Tower */
2139             !strcmp(chassis_type, "7") || /*  7: Tower */
2140             !strcmp(chassis_type, "11"))  /* 11: Main Server Chassis */
2141                 return true;
2142
2143         return false;
2144 }
2145
2146 int acpi_video_register(void)
2147 {
2148         int ret = 0;
2149
2150         mutex_lock(&register_count_mutex);
2151         if (register_count) {
2152                 /*
2153                  * if the function of acpi_video_register is already called,
2154                  * don't register the acpi_vide_bus again and return no error.
2155                  */
2156                 goto leave;
2157         }
2158
2159         /*
2160          * We're seeing a lot of bogus backlight interfaces on newer machines
2161          * without a LCD such as desktops, servers and HDMI sticks. Checking
2162          * the lcd flag fixes this, so enable this on any machines which are
2163          * win8 ready (where we also prefer the native backlight driver, so
2164          * normally the acpi_video code should not register there anyways).
2165          */
2166         if (only_lcd == -1) {
2167                 if (dmi_is_desktop() && acpi_osi_is_win8())
2168                         only_lcd = true;
2169                 else
2170                         only_lcd = false;
2171         }
2172
2173         dmi_check_system(video_dmi_table);
2174
2175         ret = acpi_bus_register_driver(&acpi_video_bus);
2176         if (ret)
2177                 goto leave;
2178
2179         /*
2180          * When the acpi_video_bus is loaded successfully, increase
2181          * the counter reference.
2182          */
2183         register_count = 1;
2184
2185 leave:
2186         mutex_unlock(&register_count_mutex);
2187         return ret;
2188 }
2189 EXPORT_SYMBOL(acpi_video_register);
2190
2191 void acpi_video_unregister(void)
2192 {
2193         mutex_lock(&register_count_mutex);
2194         if (register_count) {
2195                 acpi_bus_unregister_driver(&acpi_video_bus);
2196                 register_count = 0;
2197         }
2198         mutex_unlock(&register_count_mutex);
2199 }
2200 EXPORT_SYMBOL(acpi_video_unregister);
2201
2202 void acpi_video_unregister_backlight(void)
2203 {
2204         struct acpi_video_bus *video;
2205
2206         mutex_lock(&register_count_mutex);
2207         if (register_count) {
2208                 mutex_lock(&video_list_lock);
2209                 list_for_each_entry(video, &video_bus_head, entry)
2210                         acpi_video_bus_unregister_backlight(video);
2211                 mutex_unlock(&video_list_lock);
2212         }
2213         mutex_unlock(&register_count_mutex);
2214 }
2215
2216 bool acpi_video_handles_brightness_key_presses(void)
2217 {
2218         bool have_video_busses;
2219
2220         mutex_lock(&video_list_lock);
2221         have_video_busses = !list_empty(&video_bus_head);
2222         mutex_unlock(&video_list_lock);
2223
2224         return have_video_busses &&
2225                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2226 }
2227 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2228
2229 /*
2230  * This is kind of nasty. Hardware using Intel chipsets may require
2231  * the video opregion code to be run first in order to initialise
2232  * state before any ACPI video calls are made. To handle this we defer
2233  * registration of the video class until the opregion code has run.
2234  */
2235
2236 static int __init acpi_video_init(void)
2237 {
2238         /*
2239          * Let the module load even if ACPI is disabled (e.g. due to
2240          * a broken BIOS) so that i915.ko can still be loaded on such
2241          * old systems without an AcpiOpRegion.
2242          *
2243          * acpi_video_register() will report -ENODEV later as well due
2244          * to acpi_disabled when i915.ko tries to register itself afterwards.
2245          */
2246         if (acpi_disabled)
2247                 return 0;
2248
2249         if (intel_opregion_present())
2250                 return 0;
2251
2252         return acpi_video_register();
2253 }
2254
2255 static void __exit acpi_video_exit(void)
2256 {
2257         acpi_video_detect_exit();
2258         acpi_video_unregister();
2259
2260         return;
2261 }
2262
2263 module_init(acpi_video_init);
2264 module_exit(acpi_video_exit);