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 = 1;
  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 bool only_lcd = false;
  84 module_param(only_lcd, bool, 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 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((obj->package.count + ACPI_VIDEO_FIRST_LEVEL) *
 836                              sizeof(*br->levels), GFP_KERNEL);
 837         if (!br->levels) {
 838                 result = -ENOMEM;
 839                 goto out_free;
 840         }
 841
 842         for (i = 0; i < obj->package.count; i++) {
 843                 o = (union acpi_object *)&obj->package.elements[i];
 844                 if (o->type != ACPI_TYPE_INTEGER) {
 845                         printk(KERN_ERR PREFIX "Invalid data\n");
 846                         continue;
 847                 }
 848                 value = (u32) o->integer.value;
 849                 /* Skip duplicate entries */
 850                 if (count > ACPI_VIDEO_FIRST_LEVEL
 851                     && br->levels[count - 1] == value)
 852                         continue;
 853
 854                 br->levels[count] = value;
 855
 856                 if (br->levels[count] > max_level)
 857                         max_level = br->levels[count];
 858                 count++;
 859         }
 860
 861         /*
 862          * some buggy BIOS don't export the levels
 863          * when machine is on AC/Battery in _BCL package.
 864          * In this case, the first two elements in _BCL packages
 865          * are also supported brightness levels that OS should take care of.
 866          */
 867         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 868                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 869                         level_ac_battery++;
 870                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 871                         level_ac_battery++;
 872         }
 873
 874         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 875                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 876                 br->flags._BCL_no_ac_battery_levels = 1;
 877                 for (i = (count - 1 + level_ac_battery);
 878                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 879                         br->levels[i] = br->levels[i - level_ac_battery];
 880                 count += level_ac_battery;
 881         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 882                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 883
 884         /* Check if the _BCL package is in a reversed order */
 885         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 886                 br->flags._BCL_reversed = 1;
 887                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 888                      count - ACPI_VIDEO_FIRST_LEVEL,
 889                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 890                      acpi_video_cmp_level, NULL);
 891         } else if (max_level != br->levels[count - 1])
 892                 ACPI_ERROR((AE_INFO,
 893                             "Found unordered _BCL package"));
 894
 895         br->count = count;
 896         *dev_br = br;
 897         if (pmax_level)
 898                 *pmax_level = max_level;
 899
 900 out:
 901         kfree(obj);
 902         return result;
 903 out_free:
 904         kfree(br);
 905         goto out;
 906 }
 907 EXPORT_SYMBOL(acpi_video_get_levels);
 908
 909 /*
 910  *  Arg:
 911  *      device  : video output device (LCD, CRT, ..)
 912  *
 913  *  Return Value:
 914  *      Maximum brightness level
 915  *
 916  *  Allocate and initialize device->brightness.
 917  */
 918
 919 static int
 920 acpi_video_init_brightness(struct acpi_video_device *device)
 921 {
 922         int i, max_level = 0;
 923         unsigned long long level, level_old;
 924         struct acpi_video_device_brightness *br = NULL;
 925         int result = -EINVAL;
 926
 927         result = acpi_video_get_levels(device->dev, &br, &max_level);
 928         if (result)
 929                 return result;
 930         device->brightness = br;
 931
 932         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 933         br->curr = level = max_level;
 934
 935         if (!device->cap._BQC)
 936                 goto set_level;
 937
 938         result = acpi_video_device_lcd_get_level_current(device,
 939                                                          &level_old, true);
 940         if (result)
 941                 goto out_free_levels;
 942
 943         result = acpi_video_bqc_quirk(device, max_level, level_old);
 944         if (result)
 945                 goto out_free_levels;
 946         /*
 947          * cap._BQC may get cleared due to _BQC is found to be broken
 948          * in acpi_video_bqc_quirk, so check again here.
 949          */
 950         if (!device->cap._BQC)
 951                 goto set_level;
 952
 953         level = acpi_video_bqc_value_to_level(device, level_old);
 954         /*
 955          * On some buggy laptops, _BQC returns an uninitialized
 956          * value when invoked for the first time, i.e.
 957          * level_old is invalid (no matter whether it's a level
 958          * or an index). Set the backlight to max_level in this case.
 959          */
 960         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 961                 if (level == br->levels[i])
 962                         break;
 963         if (i == br->count || !level)
 964                 level = max_level;
 965
 966 set_level:
 967         result = acpi_video_device_lcd_set_level(device, level);
 968         if (result)
 969                 goto out_free_levels;
 970
 971         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 972                           "found %d brightness levels\n",
 973                           br->count - ACPI_VIDEO_FIRST_LEVEL));
 974         return 0;
 975
 976 out_free_levels:
 977         kfree(br->levels);
 978         kfree(br);
 979         device->brightness = NULL;
 980         return result;
 981 }
 982
 983 /*
 984  *  Arg:
 985  *      device  : video output device (LCD, CRT, ..)
 986  *
 987  *  Return Value:
 988  *      None
 989  *
 990  *  Find out all required AML methods defined under the output
 991  *  device.
 992  */
 993
 994 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 995 {
 996         if (acpi_has_method(device->dev->handle, "_ADR"))
 997                 device->cap._ADR = 1;
 998         if (acpi_has_method(device->dev->handle, "_BCL"))
 999                 device->cap._BCL = 1;
1000         if (acpi_has_method(device->dev->handle, "_BCM"))
1001                 device->cap._BCM = 1;
1002         if (acpi_has_method(device->dev->handle, "_BQC")) {
1003                 device->cap._BQC = 1;
1004         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1005                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
1006                 device->cap._BCQ = 1;
1007         }
1008
1009         if (acpi_has_method(device->dev->handle, "_DDC"))
1010                 device->cap._DDC = 1;
1011 }
1012
1013 /*
1014  *  Arg:
1015  *      device  : video output device (VGA)
1016  *
1017  *  Return Value:
1018  *      None
1019  *
1020  *  Find out all required AML methods defined under the video bus device.
1021  */
1022
1023 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1024 {
1025         if (acpi_has_method(video->device->handle, "_DOS"))
1026                 video->cap._DOS = 1;
1027         if (acpi_has_method(video->device->handle, "_DOD"))
1028                 video->cap._DOD = 1;
1029         if (acpi_has_method(video->device->handle, "_ROM"))
1030                 video->cap._ROM = 1;
1031         if (acpi_has_method(video->device->handle, "_GPD"))
1032                 video->cap._GPD = 1;
1033         if (acpi_has_method(video->device->handle, "_SPD"))
1034                 video->cap._SPD = 1;
1035         if (acpi_has_method(video->device->handle, "_VPO"))
1036                 video->cap._VPO = 1;
1037 }
1038
1039 /*
1040  * Check whether the video bus device has required AML method to
1041  * support the desired features
1042  */
1043
1044 static int acpi_video_bus_check(struct acpi_video_bus *video)
1045 {
1046         acpi_status status = -ENOENT;
1047         struct pci_dev *dev;
1048
1049         if (!video)
1050                 return -EINVAL;
1051
1052         dev = acpi_get_pci_dev(video->device->handle);
1053         if (!dev)
1054                 return -ENODEV;
1055         pci_dev_put(dev);
1056
1057         /*
1058          * Since there is no HID, CID and so on for VGA driver, we have
1059          * to check well known required nodes.
1060          */
1061
1062         /* Does this device support video switching? */
1063         if (video->cap._DOS || video->cap._DOD) {
1064                 if (!video->cap._DOS) {
1065                         printk(KERN_WARNING FW_BUG
1066                                 "ACPI(%s) defines _DOD but not _DOS\n",
1067                                 acpi_device_bid(video->device));
1068                 }
1069                 video->flags.multihead = 1;
1070                 status = 0;
1071         }
1072
1073         /* Does this device support retrieving a video ROM? */
1074         if (video->cap._ROM) {
1075                 video->flags.rom = 1;
1076                 status = 0;
1077         }
1078
1079         /* Does this device support configuring which video device to POST? */
1080         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1081                 video->flags.post = 1;
1082                 status = 0;
1083         }
1084
1085         return status;
1086 }
1087
1088 /*
1089  * --------------------------------------------------------------------------
1090  *                               Driver Interface
1091  * --------------------------------------------------------------------------
1092  */
1093
1094 /* device interface */
1095 static struct acpi_video_device_attrib *
1096 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1097 {
1098         struct acpi_video_enumerated_device *ids;
1099         int i;
1100
1101         for (i = 0; i < video->attached_count; i++) {
1102                 ids = &video->attached_array[i];
1103                 if ((ids->value.int_val & 0xffff) == device_id)
1104                         return &ids->value.attrib;
1105         }
1106
1107         return NULL;
1108 }
1109
1110 static int
1111 acpi_video_get_device_type(struct acpi_video_bus *video,
1112                            unsigned long device_id)
1113 {
1114         struct acpi_video_enumerated_device *ids;
1115         int i;
1116
1117         for (i = 0; i < video->attached_count; i++) {
1118                 ids = &video->attached_array[i];
1119                 if ((ids->value.int_val & 0xffff) == device_id)
1120                         return ids->value.int_val;
1121         }
1122
1123         return 0;
1124 }
1125
1126 static int
1127 acpi_video_bus_get_one_device(struct acpi_device *device,
1128                               struct acpi_video_bus *video)
1129 {
1130         unsigned long long device_id;
1131         int status, device_type;
1132         struct acpi_video_device *data;
1133         struct acpi_video_device_attrib *attribute;
1134
1135         status =
1136             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1137         /* Some device omits _ADR, we skip them instead of fail */
1138         if (ACPI_FAILURE(status))
1139                 return 0;
1140
1141         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1142         if (!data)
1143                 return -ENOMEM;
1144
1145         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1146         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1147         device->driver_data = data;
1148
1149         data->device_id = device_id;
1150         data->video = video;
1151         data->dev = device;
1152         INIT_DELAYED_WORK(&data->switch_brightness_work,
1153                           acpi_video_switch_brightness);
1154
1155         attribute = acpi_video_get_device_attr(video, device_id);
1156
1157         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1158                 switch (attribute->display_type) {
1159                 case ACPI_VIDEO_DISPLAY_CRT:
1160                         data->flags.crt = 1;
1161                         break;
1162                 case ACPI_VIDEO_DISPLAY_TV:
1163                         data->flags.tvout = 1;
1164                         break;
1165                 case ACPI_VIDEO_DISPLAY_DVI:
1166                         data->flags.dvi = 1;
1167                         break;
1168                 case ACPI_VIDEO_DISPLAY_LCD:
1169                         data->flags.lcd = 1;
1170                         break;
1171                 default:
1172                         data->flags.unknown = 1;
1173                         break;
1174                 }
1175                 if (attribute->bios_can_detect)
1176                         data->flags.bios = 1;
1177         } else {
1178                 /* Check for legacy IDs */
1179                 device_type = acpi_video_get_device_type(video, device_id);
1180                 /* Ignore bits 16 and 18-20 */
1181                 switch (device_type & 0xffe2ffff) {
1182                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1183                         data->flags.crt = 1;
1184                         break;
1185                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1186                         data->flags.lcd = 1;
1187                         break;
1188                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1189                         data->flags.tvout = 1;
1190                         break;
1191                 default:
1192                         data->flags.unknown = 1;
1193                 }
1194         }
1195
1196         acpi_video_device_bind(video, data);
1197         acpi_video_device_find_cap(data);
1198
1199         mutex_lock(&video->device_list_lock);
1200         list_add_tail(&data->entry, &video->video_device_list);
1201         mutex_unlock(&video->device_list_lock);
1202
1203         return status;
1204 }
1205
1206 /*
1207  *  Arg:
1208  *      video   : video bus device
1209  *
1210  *  Return:
1211  *      none
1212  *
1213  *  Enumerate the video device list of the video bus,
1214  *  bind the ids with the corresponding video devices
1215  *  under the video bus.
1216  */
1217
1218 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1219 {
1220         struct acpi_video_device *dev;
1221
1222         mutex_lock(&video->device_list_lock);
1223
1224         list_for_each_entry(dev, &video->video_device_list, entry)
1225                 acpi_video_device_bind(video, dev);
1226
1227         mutex_unlock(&video->device_list_lock);
1228 }
1229
1230 /*
1231  *  Arg:
1232  *      video   : video bus device
1233  *      device  : video output device under the video
1234  *              bus
1235  *
1236  *  Return:
1237  *      none
1238  *
1239  *  Bind the ids with the corresponding video devices
1240  *  under the video bus.
1241  */
1242
1243 static void
1244 acpi_video_device_bind(struct acpi_video_bus *video,
1245                        struct acpi_video_device *device)
1246 {
1247         struct acpi_video_enumerated_device *ids;
1248         int i;
1249
1250         for (i = 0; i < video->attached_count; i++) {
1251                 ids = &video->attached_array[i];
1252                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1253                         ids->bind_info = device;
1254                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1255                 }
1256         }
1257 }
1258
1259 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1260 {
1261         struct acpi_video_bus *video = device->video;
1262         int i;
1263
1264         /*
1265          * If we have a broken _DOD or we have more than 8 output devices
1266          * under the graphics controller node that we can't proper deal with
1267          * in the operation region code currently, no need to test.
1268          */
1269         if (!video->attached_count || video->child_count > 8)
1270                 return true;
1271
1272         for (i = 0; i < video->attached_count; i++) {
1273                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1274                     (device->device_id & 0xfff))
1275                         return true;
1276         }
1277
1278         return false;
1279 }
1280
1281 /*
1282  *  Arg:
1283  *      video   : video bus device
1284  *
1285  *  Return:
1286  *      < 0     : error
1287  *
1288  *  Call _DOD to enumerate all devices attached to display adapter
1289  *
1290  */
1291
1292 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1293 {
1294         int status;
1295         int count;
1296         int i;
1297         struct acpi_video_enumerated_device *active_list;
1298         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1299         union acpi_object *dod = NULL;
1300         union acpi_object *obj;
1301
1302         if (!video->cap._DOD)
1303                 return AE_NOT_EXIST;
1304
1305         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1306         if (!ACPI_SUCCESS(status)) {
1307                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1308                 return status;
1309         }
1310
1311         dod = buffer.pointer;
1312         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1313                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1314                 status = -EFAULT;
1315                 goto out;
1316         }
1317
1318         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1319                           dod->package.count));
1320
1321         active_list = kcalloc(1 + dod->package.count,
1322                               sizeof(struct acpi_video_enumerated_device),
1323                               GFP_KERNEL);
1324         if (!active_list) {
1325                 status = -ENOMEM;
1326                 goto out;
1327         }
1328
1329         count = 0;
1330         for (i = 0; i < dod->package.count; i++) {
1331                 obj = &dod->package.elements[i];
1332
1333                 if (obj->type != ACPI_TYPE_INTEGER) {
1334                         printk(KERN_ERR PREFIX
1335                                 "Invalid _DOD data in element %d\n", i);
1336                         continue;
1337                 }
1338
1339                 active_list[count].value.int_val = obj->integer.value;
1340                 active_list[count].bind_info = NULL;
1341                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1342                                   (int)obj->integer.value));
1343                 count++;
1344         }
1345
1346         kfree(video->attached_array);
1347
1348         video->attached_array = active_list;
1349         video->attached_count = count;
1350
1351 out:
1352         kfree(buffer.pointer);
1353         return status;
1354 }
1355
1356 static int
1357 acpi_video_get_next_level(struct acpi_video_device *device,
1358                           u32 level_current, u32 event)
1359 {
1360         int min, max, min_above, max_below, i, l, delta = 255;
1361         max = max_below = 0;
1362         min = min_above = 255;
1363         /* Find closest level to level_current */
1364         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1365                 l = device->brightness->levels[i];
1366                 if (abs(l - level_current) < abs(delta)) {
1367                         delta = l - level_current;
1368                         if (!delta)
1369                                 break;
1370                 }
1371         }
1372         /* Ajust level_current to closest available level */
1373         level_current += delta;
1374         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1375                 l = device->brightness->levels[i];
1376                 if (l < min)
1377                         min = l;
1378                 if (l > max)
1379                         max = l;
1380                 if (l < min_above && l > level_current)
1381                         min_above = l;
1382                 if (l > max_below && l < level_current)
1383                         max_below = l;
1384         }
1385
1386         switch (event) {
1387         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1388                 return (level_current < max) ? min_above : min;
1389         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1390                 return (level_current < max) ? min_above : max;
1391         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1392                 return (level_current > min) ? max_below : min;
1393         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1394         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1395                 return 0;
1396         default:
1397                 return level_current;
1398         }
1399 }
1400
1401 static void
1402 acpi_video_switch_brightness(struct work_struct *work)
1403 {
1404         struct acpi_video_device *device = container_of(to_delayed_work(work),
1405                              struct acpi_video_device, switch_brightness_work);
1406         unsigned long long level_current, level_next;
1407         int event = device->switch_brightness_event;
1408         int result = -EINVAL;
1409
1410         /* no warning message if acpi_backlight=vendor or a quirk is used */
1411         if (!device->backlight)
1412                 return;
1413
1414         if (!device->brightness)
1415                 goto out;
1416
1417         result = acpi_video_device_lcd_get_level_current(device,
1418                                                          &level_current,
1419                                                          false);
1420         if (result)
1421                 goto out;
1422
1423         level_next = acpi_video_get_next_level(device, level_current, event);
1424
1425         result = acpi_video_device_lcd_set_level(device, level_next);
1426
1427         if (!result)
1428                 backlight_force_update(device->backlight,
1429                                        BACKLIGHT_UPDATE_HOTKEY);
1430
1431 out:
1432         if (result)
1433                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1434 }
1435
1436 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1437                         void **edid)
1438 {
1439         struct acpi_video_bus *video;
1440         struct acpi_video_device *video_device;
1441         union acpi_object *buffer = NULL;
1442         acpi_status status;
1443         int i, length;
1444
1445         if (!device || !acpi_driver_data(device))
1446                 return -EINVAL;
1447
1448         video = acpi_driver_data(device);
1449
1450         for (i = 0; i < video->attached_count; i++) {
1451                 video_device = video->attached_array[i].bind_info;
1452                 length = 256;
1453
1454                 if (!video_device)
1455                         continue;
1456
1457                 if (!video_device->cap._DDC)
1458                         continue;
1459
1460                 if (type) {
1461                         switch (type) {
1462                         case ACPI_VIDEO_DISPLAY_CRT:
1463                                 if (!video_device->flags.crt)
1464                                         continue;
1465                                 break;
1466                         case ACPI_VIDEO_DISPLAY_TV:
1467                                 if (!video_device->flags.tvout)
1468                                         continue;
1469                                 break;
1470                         case ACPI_VIDEO_DISPLAY_DVI:
1471                                 if (!video_device->flags.dvi)
1472                                         continue;
1473                                 break;
1474                         case ACPI_VIDEO_DISPLAY_LCD:
1475                                 if (!video_device->flags.lcd)
1476                                         continue;
1477                                 break;
1478                         }
1479                 } else if (video_device->device_id != device_id) {
1480                         continue;
1481                 }
1482
1483                 status = acpi_video_device_EDID(video_device, &buffer, length);
1484
1485                 if (ACPI_FAILURE(status) || !buffer ||
1486                     buffer->type != ACPI_TYPE_BUFFER) {
1487                         length = 128;
1488                         status = acpi_video_device_EDID(video_device, &buffer,
1489                                                         length);
1490                         if (ACPI_FAILURE(status) || !buffer ||
1491                             buffer->type != ACPI_TYPE_BUFFER) {
1492                                 continue;
1493                         }
1494                 }
1495
1496                 *edid = buffer->buffer.pointer;
1497                 return length;
1498         }
1499
1500         return -ENODEV;
1501 }
1502 EXPORT_SYMBOL(acpi_video_get_edid);
1503
1504 static int
1505 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1506                            struct acpi_device *device)
1507 {
1508         int status = 0;
1509         struct acpi_device *dev;
1510
1511         /*
1512          * There are systems where video module known to work fine regardless
1513          * of broken _DOD and ignoring returned value here doesn't cause
1514          * any issues later.
1515          */
1516         acpi_video_device_enumerate(video);
1517
1518         list_for_each_entry(dev, &device->children, node) {
1519
1520                 status = acpi_video_bus_get_one_device(dev, video);
1521                 if (status) {
1522                         dev_err(&dev->dev, "Can't attach device\n");
1523                         break;
1524                 }
1525                 video->child_count++;
1526         }
1527         return status;
1528 }
1529
1530 /* acpi_video interface */
1531
1532 /*
1533  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1534  * preform any automatic brightness change on receiving a notification.
1535  */
1536 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1537 {
1538         return acpi_video_bus_DOS(video, 0,
1539                                   acpi_osi_is_win8() ? 1 : 0);
1540 }
1541
1542 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1543 {
1544         return acpi_video_bus_DOS(video, 0,
1545                                   acpi_osi_is_win8() ? 0 : 1);
1546 }
1547
1548 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1549 {
1550         struct acpi_video_bus *video = acpi_driver_data(device);
1551         struct input_dev *input;
1552         int keycode = 0;
1553
1554         if (!video || !video->input)
1555                 return;
1556
1557         input = video->input;
1558
1559         switch (event) {
1560         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1561                                          * most likely via hotkey. */
1562                 keycode = KEY_SWITCHVIDEOMODE;
1563                 break;
1564
1565         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1566                                          * connector. */
1567                 acpi_video_device_enumerate(video);
1568                 acpi_video_device_rebind(video);
1569                 keycode = KEY_SWITCHVIDEOMODE;
1570                 break;
1571
1572         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1573                 keycode = KEY_SWITCHVIDEOMODE;
1574                 break;
1575         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1576                 keycode = KEY_VIDEO_NEXT;
1577                 break;
1578         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1579                 keycode = KEY_VIDEO_PREV;
1580                 break;
1581
1582         default:
1583                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1584                                   "Unsupported event [0x%x]\n", event));
1585                 break;
1586         }
1587
1588         if (acpi_notifier_call_chain(device, event, 0))
1589                 /* Something vetoed the keypress. */
1590                 keycode = 0;
1591
1592         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1593                 input_report_key(input, keycode, 1);
1594                 input_sync(input);
1595                 input_report_key(input, keycode, 0);
1596                 input_sync(input);
1597         }
1598
1599         return;
1600 }
1601
1602 static void brightness_switch_event(struct acpi_video_device *video_device,
1603                                     u32 event)
1604 {
1605         if (!brightness_switch_enabled)
1606                 return;
1607
1608         video_device->switch_brightness_event = event;
1609         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1610 }
1611
1612 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1613 {
1614         struct acpi_video_device *video_device = data;
1615         struct acpi_device *device = NULL;
1616         struct acpi_video_bus *bus;
1617         struct input_dev *input;
1618         int keycode = 0;
1619
1620         if (!video_device)
1621                 return;
1622
1623         device = video_device->dev;
1624         bus = video_device->video;
1625         input = bus->input;
1626
1627         switch (event) {
1628         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1629                 brightness_switch_event(video_device, event);
1630                 keycode = KEY_BRIGHTNESS_CYCLE;
1631                 break;
1632         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1633                 brightness_switch_event(video_device, event);
1634                 keycode = KEY_BRIGHTNESSUP;
1635                 break;
1636         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1637                 brightness_switch_event(video_device, event);
1638                 keycode = KEY_BRIGHTNESSDOWN;
1639                 break;
1640         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1641                 brightness_switch_event(video_device, event);
1642                 keycode = KEY_BRIGHTNESS_ZERO;
1643                 break;
1644         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1645                 brightness_switch_event(video_device, event);
1646                 keycode = KEY_DISPLAY_OFF;
1647                 break;
1648         default:
1649                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1650                                   "Unsupported event [0x%x]\n", event));
1651                 break;
1652         }
1653
1654         acpi_notifier_call_chain(device, event, 0);
1655
1656         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1657                 input_report_key(input, keycode, 1);
1658                 input_sync(input);
1659                 input_report_key(input, keycode, 0);
1660                 input_sync(input);
1661         }
1662
1663         return;
1664 }
1665
1666 static int acpi_video_resume(struct notifier_block *nb,
1667                                 unsigned long val, void *ign)
1668 {
1669         struct acpi_video_bus *video;
1670         struct acpi_video_device *video_device;
1671         int i;
1672
1673         switch (val) {
1674         case PM_HIBERNATION_PREPARE:
1675         case PM_SUSPEND_PREPARE:
1676         case PM_RESTORE_PREPARE:
1677                 return NOTIFY_DONE;
1678         }
1679
1680         video = container_of(nb, struct acpi_video_bus, pm_nb);
1681
1682         dev_info(&video->device->dev, "Restoring backlight state\n");
1683
1684         for (i = 0; i < video->attached_count; i++) {
1685                 video_device = video->attached_array[i].bind_info;
1686                 if (video_device && video_device->brightness)
1687                         acpi_video_device_lcd_set_level(video_device,
1688                                         video_device->brightness->curr);
1689         }
1690
1691         return NOTIFY_OK;
1692 }
1693
1694 static acpi_status
1695 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1696                         void **return_value)
1697 {
1698         struct acpi_device *device = context;
1699         struct acpi_device *sibling;
1700         int result;
1701
1702         if (handle == device->handle)
1703                 return AE_CTRL_TERMINATE;
1704
1705         result = acpi_bus_get_device(handle, &sibling);
1706         if (result)
1707                 return AE_OK;
1708
1709         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1710                         return AE_ALREADY_EXISTS;
1711
1712         return AE_OK;
1713 }
1714
1715 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1716 {
1717         struct backlight_properties props;
1718         struct pci_dev *pdev;
1719         acpi_handle acpi_parent;
1720         struct device *parent = NULL;
1721         int result;
1722         static int count;
1723         char *name;
1724
1725         result = acpi_video_init_brightness(device);
1726         if (result)
1727                 return;
1728
1729         if (disable_backlight_sysfs_if > 0)
1730                 return;
1731
1732         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1733         if (!name)
1734                 return;
1735         count++;
1736
1737         acpi_get_parent(device->dev->handle, &acpi_parent);
1738
1739         pdev = acpi_get_pci_dev(acpi_parent);
1740         if (pdev) {
1741                 parent = &pdev->dev;
1742                 pci_dev_put(pdev);
1743         }
1744
1745         memset(&props, 0, sizeof(struct backlight_properties));
1746         props.type = BACKLIGHT_FIRMWARE;
1747         props.max_brightness =
1748                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1749         device->backlight = backlight_device_register(name,
1750                                                       parent,
1751                                                       device,
1752                                                       &acpi_backlight_ops,
1753                                                       &props);
1754         kfree(name);
1755         if (IS_ERR(device->backlight)) {
1756                 device->backlight = NULL;
1757                 return;
1758         }
1759
1760         /*
1761          * Save current brightness level in case we have to restore it
1762          * before acpi_video_device_lcd_set_level() is called next time.
1763          */
1764         device->backlight->props.brightness =
1765                         acpi_video_get_brightness(device->backlight);
1766
1767         device->cooling_dev = thermal_cooling_device_register("LCD",
1768                                 device->dev, &video_cooling_ops);
1769         if (IS_ERR(device->cooling_dev)) {
1770                 /*
1771                  * Set cooling_dev to NULL so we don't crash trying to free it.
1772                  * Also, why the hell we are returning early and not attempt to
1773                  * register video output if cooling device registration failed?
1774                  * -- dtor
1775                  */
1776                 device->cooling_dev = NULL;
1777                 return;
1778         }
1779
1780         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1781                  device->cooling_dev->id);
1782         result = sysfs_create_link(&device->dev->dev.kobj,
1783                         &device->cooling_dev->device.kobj,
1784                         "thermal_cooling");
1785         if (result)
1786                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1787         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1788                         &device->dev->dev.kobj, "device");
1789         if (result)
1790                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1791 }
1792
1793 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1794 {
1795         struct acpi_video_device *dev;
1796         union acpi_object *levels;
1797
1798         mutex_lock(&video->device_list_lock);
1799         list_for_each_entry(dev, &video->video_device_list, entry) {
1800                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1801                         kfree(levels);
1802         }
1803         mutex_unlock(&video->device_list_lock);
1804 }
1805
1806 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1807 {
1808         /*
1809          * Do not create backlight device for video output
1810          * device that is not in the enumerated list.
1811          */
1812         if (!acpi_video_device_in_dod(dev)) {
1813                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1814                 return false;
1815         }
1816
1817         if (only_lcd)
1818                 return dev->flags.lcd;
1819         return true;
1820 }
1821
1822 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1823 {
1824         struct acpi_video_device *dev;
1825
1826         if (video->backlight_registered)
1827                 return 0;
1828
1829         acpi_video_run_bcl_for_osi(video);
1830
1831         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1832                 return 0;
1833
1834         mutex_lock(&video->device_list_lock);
1835         list_for_each_entry(dev, &video->video_device_list, entry) {
1836                 if (acpi_video_should_register_backlight(dev))
1837                         acpi_video_dev_register_backlight(dev);
1838         }
1839         mutex_unlock(&video->device_list_lock);
1840
1841         video->backlight_registered = true;
1842
1843         video->pm_nb.notifier_call = acpi_video_resume;
1844         video->pm_nb.priority = 0;
1845         return register_pm_notifier(&video->pm_nb);
1846 }
1847
1848 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1849 {
1850         if (device->backlight) {
1851                 backlight_device_unregister(device->backlight);
1852                 device->backlight = NULL;
1853         }
1854         if (device->brightness) {
1855                 kfree(device->brightness->levels);
1856                 kfree(device->brightness);
1857                 device->brightness = NULL;
1858         }
1859         if (device->cooling_dev) {
1860                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1861                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1862                 thermal_cooling_device_unregister(device->cooling_dev);
1863                 device->cooling_dev = NULL;
1864         }
1865 }
1866
1867 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1868 {
1869         struct acpi_video_device *dev;
1870         int error;
1871
1872         if (!video->backlight_registered)
1873                 return 0;
1874
1875         error = unregister_pm_notifier(&video->pm_nb);
1876
1877         mutex_lock(&video->device_list_lock);
1878         list_for_each_entry(dev, &video->video_device_list, entry)
1879                 acpi_video_dev_unregister_backlight(dev);
1880         mutex_unlock(&video->device_list_lock);
1881
1882         video->backlight_registered = false;
1883
1884         return error;
1885 }
1886
1887 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1888 {
1889         acpi_status status;
1890         struct acpi_device *adev = device->dev;
1891
1892         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1893                                              acpi_video_device_notify, device);
1894         if (ACPI_FAILURE(status))
1895                 dev_err(&adev->dev, "Error installing notify handler\n");
1896         else
1897                 device->flags.notify = 1;
1898 }
1899
1900 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1901 {
1902         struct input_dev *input;
1903         struct acpi_video_device *dev;
1904         int error;
1905
1906         video->input = input = input_allocate_device();
1907         if (!input) {
1908                 error = -ENOMEM;
1909                 goto out;
1910         }
1911
1912         error = acpi_video_bus_start_devices(video);
1913         if (error)
1914                 goto err_free_input;
1915
1916         snprintf(video->phys, sizeof(video->phys),
1917                         "%s/video/input0", acpi_device_hid(video->device));
1918
1919         input->name = acpi_device_name(video->device);
1920         input->phys = video->phys;
1921         input->id.bustype = BUS_HOST;
1922         input->id.product = 0x06;
1923         input->dev.parent = &video->device->dev;
1924         input->evbit[0] = BIT(EV_KEY);
1925         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1926         set_bit(KEY_VIDEO_NEXT, input->keybit);
1927         set_bit(KEY_VIDEO_PREV, input->keybit);
1928         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1929         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1930         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1931         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1932         set_bit(KEY_DISPLAY_OFF, input->keybit);
1933
1934         error = input_register_device(input);
1935         if (error)
1936                 goto err_stop_dev;
1937
1938         mutex_lock(&video->device_list_lock);
1939         list_for_each_entry(dev, &video->video_device_list, entry)
1940                 acpi_video_dev_add_notify_handler(dev);
1941         mutex_unlock(&video->device_list_lock);
1942
1943         return 0;
1944
1945 err_stop_dev:
1946         acpi_video_bus_stop_devices(video);
1947 err_free_input:
1948         input_free_device(input);
1949         video->input = NULL;
1950 out:
1951         return error;
1952 }
1953
1954 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1955 {
1956         if (dev->flags.notify) {
1957                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1958                                            acpi_video_device_notify);
1959                 dev->flags.notify = 0;
1960         }
1961 }
1962
1963 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1964 {
1965         struct acpi_video_device *dev;
1966
1967         mutex_lock(&video->device_list_lock);
1968         list_for_each_entry(dev, &video->video_device_list, entry)
1969                 acpi_video_dev_remove_notify_handler(dev);
1970         mutex_unlock(&video->device_list_lock);
1971
1972         acpi_video_bus_stop_devices(video);
1973         input_unregister_device(video->input);
1974         video->input = NULL;
1975 }
1976
1977 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1978 {
1979         struct acpi_video_device *dev, *next;
1980
1981         mutex_lock(&video->device_list_lock);
1982         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1983                 list_del(&dev->entry);
1984                 kfree(dev);
1985         }
1986         mutex_unlock(&video->device_list_lock);
1987
1988         return 0;
1989 }
1990
1991 static int instance;
1992
1993 static int acpi_video_bus_add(struct acpi_device *device)
1994 {
1995         struct acpi_video_bus *video;
1996         int error;
1997         acpi_status status;
1998
1999         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2000                                 device->parent->handle, 1,
2001                                 acpi_video_bus_match, NULL,
2002                                 device, NULL);
2003         if (status == AE_ALREADY_EXISTS) {
2004                 printk(KERN_WARNING FW_BUG
2005                         "Duplicate ACPI video bus devices for the"
2006                         " same VGA controller, please try module "
2007                         "parameter \"video.allow_duplicates=1\""
2008                         "if the current driver doesn't work.\n");
2009                 if (!allow_duplicates)
2010                         return -ENODEV;
2011         }
2012
2013         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2014         if (!video)
2015                 return -ENOMEM;
2016
2017         /* a hack to fix the duplicate name "VID" problem on T61 */
2018         if (!strcmp(device->pnp.bus_id, "VID")) {
2019                 if (instance)
2020                         device->pnp.bus_id[3] = '0' + instance;
2021                 instance++;
2022         }
2023         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2024         if (!strcmp(device->pnp.bus_id, "VGA")) {
2025                 if (instance)
2026                         device->pnp.bus_id[3] = '0' + instance;
2027                 instance++;
2028         }
2029
2030         video->device = device;
2031         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2032         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2033         device->driver_data = video;
2034
2035         acpi_video_bus_find_cap(video);
2036         error = acpi_video_bus_check(video);
2037         if (error)
2038                 goto err_free_video;
2039
2040         mutex_init(&video->device_list_lock);
2041         INIT_LIST_HEAD(&video->video_device_list);
2042
2043         error = acpi_video_bus_get_devices(video, device);
2044         if (error)
2045                 goto err_put_video;
2046
2047         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2048                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2049                video->flags.multihead ? "yes" : "no",
2050                video->flags.rom ? "yes" : "no",
2051                video->flags.post ? "yes" : "no");
2052         mutex_lock(&video_list_lock);
2053         list_add_tail(&video->entry, &video_bus_head);
2054         mutex_unlock(&video_list_lock);
2055
2056         acpi_video_bus_register_backlight(video);
2057         acpi_video_bus_add_notify_handler(video);
2058
2059         return 0;
2060
2061 err_put_video:
2062         acpi_video_bus_put_devices(video);
2063         kfree(video->attached_array);
2064 err_free_video:
2065         kfree(video);
2066         device->driver_data = NULL;
2067
2068         return error;
2069 }
2070
2071 static int acpi_video_bus_remove(struct acpi_device *device)
2072 {
2073         struct acpi_video_bus *video = NULL;
2074
2075
2076         if (!device || !acpi_driver_data(device))
2077                 return -EINVAL;
2078
2079         video = acpi_driver_data(device);
2080
2081         acpi_video_bus_remove_notify_handler(video);
2082         acpi_video_bus_unregister_backlight(video);
2083         acpi_video_bus_put_devices(video);
2084
2085         mutex_lock(&video_list_lock);
2086         list_del(&video->entry);
2087         mutex_unlock(&video_list_lock);
2088
2089         kfree(video->attached_array);
2090         kfree(video);
2091
2092         return 0;
2093 }
2094
2095 static int __init is_i740(struct pci_dev *dev)
2096 {
2097         if (dev->device == 0x00D1)
2098                 return 1;
2099         if (dev->device == 0x7000)
2100                 return 1;
2101         return 0;
2102 }
2103
2104 static int __init intel_opregion_present(void)
2105 {
2106         int opregion = 0;
2107         struct pci_dev *dev = NULL;
2108         u32 address;
2109
2110         for_each_pci_dev(dev) {
2111                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2112                         continue;
2113                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2114                         continue;
2115                 /* We don't want to poke around undefined i740 registers */
2116                 if (is_i740(dev))
2117                         continue;
2118                 pci_read_config_dword(dev, 0xfc, &address);
2119                 if (!address)
2120                         continue;
2121                 opregion = 1;
2122         }
2123         return opregion;
2124 }
2125
2126 int acpi_video_register(void)
2127 {
2128         int ret = 0;
2129
2130         mutex_lock(&register_count_mutex);
2131         if (register_count) {
2132                 /*
2133                  * if the function of acpi_video_register is already called,
2134                  * don't register the acpi_vide_bus again and return no error.
2135                  */
2136                 goto leave;
2137         }
2138
2139         dmi_check_system(video_dmi_table);
2140
2141         ret = acpi_bus_register_driver(&acpi_video_bus);
2142         if (ret)
2143                 goto leave;
2144
2145         /*
2146          * When the acpi_video_bus is loaded successfully, increase
2147          * the counter reference.
2148          */
2149         register_count = 1;
2150
2151 leave:
2152         mutex_unlock(&register_count_mutex);
2153         return ret;
2154 }
2155 EXPORT_SYMBOL(acpi_video_register);
2156
2157 void acpi_video_unregister(void)
2158 {
2159         mutex_lock(&register_count_mutex);
2160         if (register_count) {
2161                 acpi_bus_unregister_driver(&acpi_video_bus);
2162                 register_count = 0;
2163         }
2164         mutex_unlock(&register_count_mutex);
2165 }
2166 EXPORT_SYMBOL(acpi_video_unregister);
2167
2168 void acpi_video_unregister_backlight(void)
2169 {
2170         struct acpi_video_bus *video;
2171
2172         mutex_lock(&register_count_mutex);
2173         if (register_count) {
2174                 mutex_lock(&video_list_lock);
2175                 list_for_each_entry(video, &video_bus_head, entry)
2176                         acpi_video_bus_unregister_backlight(video);
2177                 mutex_unlock(&video_list_lock);
2178         }
2179         mutex_unlock(&register_count_mutex);
2180 }
2181
2182 bool acpi_video_handles_brightness_key_presses(void)
2183 {
2184         bool have_video_busses;
2185
2186         mutex_lock(&video_list_lock);
2187         have_video_busses = !list_empty(&video_bus_head);
2188         mutex_unlock(&video_list_lock);
2189
2190         return have_video_busses &&
2191                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2192 }
2193 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2194
2195 /*
2196  * This is kind of nasty. Hardware using Intel chipsets may require
2197  * the video opregion code to be run first in order to initialise
2198  * state before any ACPI video calls are made. To handle this we defer
2199  * registration of the video class until the opregion code has run.
2200  */
2201
2202 static int __init acpi_video_init(void)
2203 {
2204         /*
2205          * Let the module load even if ACPI is disabled (e.g. due to
2206          * a broken BIOS) so that i915.ko can still be loaded on such
2207          * old systems without an AcpiOpRegion.
2208          *
2209          * acpi_video_register() will report -ENODEV later as well due
2210          * to acpi_disabled when i915.ko tries to register itself afterwards.
2211          */
2212         if (acpi_disabled)
2213                 return 0;
2214
2215         if (intel_opregion_present())
2216                 return 0;
2217
2218         return acpi_video_register();
2219 }
2220
2221 static void __exit acpi_video_exit(void)
2222 {
2223         acpi_video_detect_exit();
2224         acpi_video_unregister();
2225
2226         return;
2227 }
2228
2229 module_init(acpi_video_init);
2230 module_exit(acpi_video_exit);