drivers/acpi/acpi_video.c

   1 /*
   2  *  video.c - ACPI Video Driver
   3  *
   4  *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
   5  *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
   6  *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
   7  *
   8  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 2 of the License, or (at
  13  *  your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful, but
  16  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  *  General Public License for more details.
  19  *
  20  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/list.h>
  28 #include <linux/mutex.h>
  29 #include <linux/input.h>
  30 #include <linux/backlight.h>
  31 #include <linux/thermal.h>
  32 #include <linux/sort.h>
  33 #include <linux/pci.h>
  34 #include <linux/pci_ids.h>
  35 #include <linux/slab.h>
  36 #include <linux/dmi.h>
  37 #include <linux/suspend.h>
  38 #include <linux/acpi.h>
  39 #include <acpi/video.h>
  40 #include <asm/uaccess.h>
  41
  42 #define PREFIX "ACPI: "
  43
  44 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
  45 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  46 #define ACPI_VIDEO_NOTIFY_SWITCH        0x80
  47 #define ACPI_VIDEO_NOTIFY_PROBE         0x81
  48 #define ACPI_VIDEO_NOTIFY_CYCLE         0x82
  49 #define ACPI_VIDEO_NOTIFY_NEXT_OUTPUT   0x83
  50 #define ACPI_VIDEO_NOTIFY_PREV_OUTPUT   0x84
  51
  52 #define ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS      0x85
  53 #define ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS        0x86
  54 #define ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS        0x87
  55 #define ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS       0x88
  56 #define ACPI_VIDEO_NOTIFY_DISPLAY_OFF           0x89
  57
  58 #define MAX_NAME_LEN    20
  59
  60 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  61 ACPI_MODULE_NAME("video");
  62
  63 MODULE_AUTHOR("Bruno Ducrot");
  64 MODULE_DESCRIPTION("ACPI Video Driver");
  65 MODULE_LICENSE("GPL");
  66
  67 static bool brightness_switch_enabled = 1;
  68 module_param(brightness_switch_enabled, bool, 0644);
  69
  70 /*
  71  * By default, we don't allow duplicate ACPI video bus devices
  72  * under the same VGA controller
  73  */
  74 static bool allow_duplicates;
  75 module_param(allow_duplicates, bool, 0644);
  76
  77 static int disable_backlight_sysfs_if = -1;
  78 module_param(disable_backlight_sysfs_if, int, 0444);
  79
  80 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  81 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  82 static int report_key_events = -1;
  83 module_param(report_key_events, int, 0644);
  84 MODULE_PARM_DESC(report_key_events,
  85         "0: none, 1: output changes, 2: brightness changes, 3: all");
  86
  87 static bool device_id_scheme = false;
  88 module_param(device_id_scheme, bool, 0444);
  89
  90 static bool only_lcd = false;
  91 module_param(only_lcd, bool, 0444);
  92
  93 static int register_count;
  94 static DEFINE_MUTEX(register_count_mutex);
  95 static DEFINE_MUTEX(video_list_lock);
  96 static LIST_HEAD(video_bus_head);
  97 static int acpi_video_bus_add(struct acpi_device *device);
  98 static int acpi_video_bus_remove(struct acpi_device *device);
  99 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
 100 void acpi_video_detect_exit(void);
 101
 102 static const struct acpi_device_id video_device_ids[] = {
 103         {ACPI_VIDEO_HID, 0},
 104         {"", 0},
 105 };
 106 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 107
 108 static struct acpi_driver acpi_video_bus = {
 109         .name = "video",
 110         .class = ACPI_VIDEO_CLASS,
 111         .ids = video_device_ids,
 112         .ops = {
 113                 .add = acpi_video_bus_add,
 114                 .remove = acpi_video_bus_remove,
 115                 .notify = acpi_video_bus_notify,
 116                 },
 117 };
 118
 119 struct acpi_video_bus_flags {
 120         u8 multihead:1;         /* can switch video heads */
 121         u8 rom:1;               /* can retrieve a video rom */
 122         u8 post:1;              /* can configure the head to */
 123         u8 reserved:5;
 124 };
 125
 126 struct acpi_video_bus_cap {
 127         u8 _DOS:1;              /* Enable/Disable output switching */
 128         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 129         u8 _ROM:1;              /* Get ROM Data */
 130         u8 _GPD:1;              /* Get POST Device */
 131         u8 _SPD:1;              /* Set POST Device */
 132         u8 _VPO:1;              /* Video POST Options */
 133         u8 reserved:2;
 134 };
 135
 136 struct acpi_video_device_attrib {
 137         u32 display_index:4;    /* A zero-based instance of the Display */
 138         u32 display_port_attachment:4;  /* This field differentiates the display type */
 139         u32 display_type:4;     /* Describe the specific type in use */
 140         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 141         u32 bios_can_detect:1;  /* BIOS can detect the device */
 142         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 143                                    the VGA device. */
 144         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 145         u32 reserved:10;        /* Must be 0 */
 146         u32 device_id_scheme:1; /* Device ID Scheme */
 147 };
 148
 149 struct acpi_video_enumerated_device {
 150         union {
 151                 u32 int_val;
 152                 struct acpi_video_device_attrib attrib;
 153         } value;
 154         struct acpi_video_device *bind_info;
 155 };
 156
 157 struct acpi_video_bus {
 158         struct acpi_device *device;
 159         bool backlight_registered;
 160         u8 dos_setting;
 161         struct acpi_video_enumerated_device *attached_array;
 162         u8 attached_count;
 163         u8 child_count;
 164         struct acpi_video_bus_cap cap;
 165         struct acpi_video_bus_flags flags;
 166         struct list_head video_device_list;
 167         struct mutex device_list_lock;  /* protects video_device_list */
 168         struct list_head entry;
 169         struct input_dev *input;
 170         char phys[32];  /* for input device */
 171         struct notifier_block pm_nb;
 172 };
 173
 174 struct acpi_video_device_flags {
 175         u8 crt:1;
 176         u8 lcd:1;
 177         u8 tvout:1;
 178         u8 dvi:1;
 179         u8 bios:1;
 180         u8 unknown:1;
 181         u8 notify:1;
 182         u8 reserved:1;
 183 };
 184
 185 struct acpi_video_device_cap {
 186         u8 _ADR:1;              /* Return the unique ID */
 187         u8 _BCL:1;              /* Query list of brightness control levels supported */
 188         u8 _BCM:1;              /* Set the brightness level */
 189         u8 _BQC:1;              /* Get current brightness level */
 190         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 191         u8 _DDC:1;              /* Return the EDID for this device */
 192 };
 193
 194 struct acpi_video_device {
 195         unsigned long device_id;
 196         struct acpi_video_device_flags flags;
 197         struct acpi_video_device_cap cap;
 198         struct list_head entry;
 199         struct delayed_work switch_brightness_work;
 200         int switch_brightness_event;
 201         struct acpi_video_bus *video;
 202         struct acpi_device *dev;
 203         struct acpi_video_device_brightness *brightness;
 204         struct backlight_device *backlight;
 205         struct thermal_cooling_device *cooling_dev;
 206 };
 207
 208 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 209 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 210 static void acpi_video_device_bind(struct acpi_video_bus *video,
 211                                    struct acpi_video_device *device);
 212 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 213 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 214                         int level);
 215 static int acpi_video_device_lcd_get_level_current(
 216                         struct acpi_video_device *device,
 217                         unsigned long long *level, bool raw);
 218 static int acpi_video_get_next_level(struct acpi_video_device *device,
 219                                      u32 level_current, u32 event);
 220 static void acpi_video_switch_brightness(struct work_struct *work);
 221
 222 /* backlight device sysfs support */
 223 static int acpi_video_get_brightness(struct backlight_device *bd)
 224 {
 225         unsigned long long cur_level;
 226         int i;
 227         struct acpi_video_device *vd = bl_get_data(bd);
 228
 229         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 230                 return -EINVAL;
 231         for (i = 2; i < vd->brightness->count; i++) {
 232                 if (vd->brightness->levels[i] == cur_level)
 233                         /*
 234                          * The first two entries are special - see page 575
 235                          * of the ACPI spec 3.0
 236                          */
 237                         return i - 2;
 238         }
 239         return 0;
 240 }
 241
 242 static int acpi_video_set_brightness(struct backlight_device *bd)
 243 {
 244         int request_level = bd->props.brightness + 2;
 245         struct acpi_video_device *vd = bl_get_data(bd);
 246
 247         cancel_delayed_work(&vd->switch_brightness_work);
 248         return acpi_video_device_lcd_set_level(vd,
 249                                 vd->brightness->levels[request_level]);
 250 }
 251
 252 static const struct backlight_ops acpi_backlight_ops = {
 253         .get_brightness = acpi_video_get_brightness,
 254         .update_status  = acpi_video_set_brightness,
 255 };
 256
 257 /* thermal cooling device callbacks */
 258 static int video_get_max_state(struct thermal_cooling_device *cooling_dev, unsigned
 259                                long *state)
 260 {
 261         struct acpi_device *device = cooling_dev->devdata;
 262         struct acpi_video_device *video = acpi_driver_data(device);
 263
 264         *state = video->brightness->count - 3;
 265         return 0;
 266 }
 267
 268 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev, unsigned
 269                                long *state)
 270 {
 271         struct acpi_device *device = cooling_dev->devdata;
 272         struct acpi_video_device *video = acpi_driver_data(device);
 273         unsigned long long level;
 274         int offset;
 275
 276         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 277                 return -EINVAL;
 278         for (offset = 2; offset < video->brightness->count; offset++)
 279                 if (level == video->brightness->levels[offset]) {
 280                         *state = video->brightness->count - offset - 1;
 281                         return 0;
 282                 }
 283
 284         return -EINVAL;
 285 }
 286
 287 static int
 288 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 289 {
 290         struct acpi_device *device = cooling_dev->devdata;
 291         struct acpi_video_device *video = acpi_driver_data(device);
 292         int level;
 293
 294         if (state >= video->brightness->count - 2)
 295                 return -EINVAL;
 296
 297         state = video->brightness->count - state;
 298         level = video->brightness->levels[state - 1];
 299         return acpi_video_device_lcd_set_level(video, level);
 300 }
 301
 302 static const struct thermal_cooling_device_ops video_cooling_ops = {
 303         .get_max_state = video_get_max_state,
 304         .get_cur_state = video_get_cur_state,
 305         .set_cur_state = video_set_cur_state,
 306 };
 307
 308 /*
 309  * --------------------------------------------------------------------------
 310  *                             Video Management
 311  * --------------------------------------------------------------------------
 312  */
 313
 314 static int
 315 acpi_video_device_lcd_query_levels(acpi_handle handle,
 316                                    union acpi_object **levels)
 317 {
 318         int status;
 319         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 320         union acpi_object *obj;
 321
 322
 323         *levels = NULL;
 324
 325         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 326         if (!ACPI_SUCCESS(status))
 327                 return status;
 328         obj = (union acpi_object *)buffer.pointer;
 329         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 330                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 331                 status = -EFAULT;
 332                 goto err;
 333         }
 334
 335         *levels = obj;
 336
 337         return 0;
 338
 339 err:
 340         kfree(buffer.pointer);
 341
 342         return status;
 343 }
 344
 345 static int
 346 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 347 {
 348         int status;
 349         int state;
 350
 351         status = acpi_execute_simple_method(device->dev->handle,
 352                                             "_BCM", level);
 353         if (ACPI_FAILURE(status)) {
 354                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 355                 return -EIO;
 356         }
 357
 358         device->brightness->curr = level;
 359         for (state = 2; state < device->brightness->count; state++)
 360                 if (level == device->brightness->levels[state]) {
 361                         if (device->backlight)
 362                                 device->backlight->props.brightness = state - 2;
 363                         return 0;
 364                 }
 365
 366         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 367         return -EINVAL;
 368 }
 369
 370 /*
 371  * For some buggy _BQC methods, we need to add a constant value to
 372  * the _BQC return value to get the actual current brightness level
 373  */
 374
 375 static int bqc_offset_aml_bug_workaround;
 376 static int video_set_bqc_offset(const struct dmi_system_id *d)
 377 {
 378         bqc_offset_aml_bug_workaround = 9;
 379         return 0;
 380 }
 381
 382 static int video_disable_backlight_sysfs_if(
 383         const struct dmi_system_id *d)
 384 {
 385         if (disable_backlight_sysfs_if == -1)
 386                 disable_backlight_sysfs_if = 1;
 387         return 0;
 388 }
 389
 390 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 391 {
 392         device_id_scheme = true;
 393         return 0;
 394 }
 395
 396 static int video_enable_only_lcd(const struct dmi_system_id *d)
 397 {
 398         only_lcd = true;
 399         return 0;
 400 }
 401
 402 static int video_set_report_key_events(const struct dmi_system_id *id)
 403 {
 404         if (report_key_events == -1)
 405                 report_key_events = (uintptr_t)id->driver_data;
 406         return 0;
 407 }
 408
 409 static struct dmi_system_id video_dmi_table[] = {
 410         /*
 411          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 412          */
 413         {
 414          .callback = video_set_bqc_offset,
 415          .ident = "Acer Aspire 5720",
 416          .matches = {
 417                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 418                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 419                 },
 420         },
 421         {
 422          .callback = video_set_bqc_offset,
 423          .ident = "Acer Aspire 5710Z",
 424          .matches = {
 425                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 426                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 427                 },
 428         },
 429         {
 430          .callback = video_set_bqc_offset,
 431          .ident = "eMachines E510",
 432          .matches = {
 433                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 434                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 435                 },
 436         },
 437         {
 438          .callback = video_set_bqc_offset,
 439          .ident = "Acer Aspire 5315",
 440          .matches = {
 441                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 442                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 443                 },
 444         },
 445         {
 446          .callback = video_set_bqc_offset,
 447          .ident = "Acer Aspire 7720",
 448          .matches = {
 449                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 450                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 451                 },
 452         },
 453
 454         /*
 455          * Some machines have a broken acpi-video interface for brightness
 456          * control, but still need an acpi_video_device_lcd_set_level() call
 457          * on resume to turn the backlight power on.  We Enable backlight
 458          * control on these systems, but do not register a backlight sysfs
 459          * as brightness control does not work.
 460          */
 461         {
 462          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 463          .callback = video_disable_backlight_sysfs_if,
 464          .ident = "Toshiba Portege R700",
 465          .matches = {
 466                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 467                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 468                 },
 469         },
 470         {
 471          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 472          .callback = video_disable_backlight_sysfs_if,
 473          .ident = "Toshiba Portege R830",
 474          .matches = {
 475                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 476                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 477                 },
 478         },
 479         {
 480          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 481          .callback = video_disable_backlight_sysfs_if,
 482          .ident = "Toshiba Satellite R830",
 483          .matches = {
 484                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 485                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 486                 },
 487         },
 488         /*
 489          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 490          * but the IDs actually follow the Device ID Scheme.
 491          */
 492         {
 493          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 494          .callback = video_set_device_id_scheme,
 495          .ident = "ESPRIMO Mobile M9410",
 496          .matches = {
 497                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 498                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 499                 },
 500         },
 501         /*
 502          * Some machines have multiple video output devices, but only the one
 503          * that is the type of LCD can do the backlight control so we should not
 504          * register backlight interface for other video output devices.
 505          */
 506         {
 507          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 508          .callback = video_enable_only_lcd,
 509          .ident = "ESPRIMO Mobile M9410",
 510          .matches = {
 511                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 512                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 513                 },
 514         },
 515         /*
 516          * Some machines report wrong key events on the acpi-bus, suppress
 517          * key event reporting on these.  Note this is only intended to work
 518          * around events which are plain wrong. In some cases we get double
 519          * events, in this case acpi-video is considered the canonical source
 520          * and the events from the other source should be filtered. E.g.
 521          * by calling acpi_video_handles_brightness_key_presses() from the
 522          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 523          */
 524         {
 525          .callback = video_set_report_key_events,
 526          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 527          .ident = "Dell Vostro V131",
 528          .matches = {
 529                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 530                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 531                 },
 532         },
 533         {}
 534 };
 535
 536 static unsigned long long
 537 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 538                               unsigned long long bqc_value)
 539 {
 540         unsigned long long level;
 541
 542         if (device->brightness->flags._BQC_use_index) {
 543                 /*
 544                  * _BQC returns an index that doesn't account for
 545                  * the first 2 items with special meaning, so we need
 546                  * to compensate for that by offsetting ourselves
 547                  */
 548                 if (device->brightness->flags._BCL_reversed)
 549                         bqc_value = device->brightness->count - 3 - bqc_value;
 550
 551                 level = device->brightness->levels[bqc_value + 2];
 552         } else {
 553                 level = bqc_value;
 554         }
 555
 556         level += bqc_offset_aml_bug_workaround;
 557
 558         return level;
 559 }
 560
 561 static int
 562 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 563                                         unsigned long long *level, bool raw)
 564 {
 565         acpi_status status = AE_OK;
 566         int i;
 567
 568         if (device->cap._BQC || device->cap._BCQ) {
 569                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 570
 571                 status = acpi_evaluate_integer(device->dev->handle, buf,
 572                                                 NULL, level);
 573                 if (ACPI_SUCCESS(status)) {
 574                         if (raw) {
 575                                 /*
 576                                  * Caller has indicated he wants the raw
 577                                  * value returned by _BQC, so don't furtherly
 578                                  * mess with the value.
 579                                  */
 580                                 return 0;
 581                         }
 582
 583                         *level = acpi_video_bqc_value_to_level(device, *level);
 584
 585                         for (i = 2; i < device->brightness->count; i++)
 586                                 if (device->brightness->levels[i] == *level) {
 587                                         device->brightness->curr = *level;
 588                                         return 0;
 589                                 }
 590                         /*
 591                          * BQC returned an invalid level.
 592                          * Stop using it.
 593                          */
 594                         ACPI_WARNING((AE_INFO,
 595                                       "%s returned an invalid level",
 596                                       buf));
 597                         device->cap._BQC = device->cap._BCQ = 0;
 598                 } else {
 599                         /*
 600                          * Fixme:
 601                          * should we return an error or ignore this failure?
 602                          * dev->brightness->curr is a cached value which stores
 603                          * the correct current backlight level in most cases.
 604                          * ACPI video backlight still works w/ buggy _BQC.
 605                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 606                          */
 607                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 608                         device->cap._BQC = device->cap._BCQ = 0;
 609                 }
 610         }
 611
 612         *level = device->brightness->curr;
 613         return 0;
 614 }
 615
 616 static int
 617 acpi_video_device_EDID(struct acpi_video_device *device,
 618                        union acpi_object **edid, ssize_t length)
 619 {
 620         int status;
 621         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 622         union acpi_object *obj;
 623         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 624         struct acpi_object_list args = { 1, &arg0 };
 625
 626
 627         *edid = NULL;
 628
 629         if (!device)
 630                 return -ENODEV;
 631         if (length == 128)
 632                 arg0.integer.value = 1;
 633         else if (length == 256)
 634                 arg0.integer.value = 2;
 635         else
 636                 return -EINVAL;
 637
 638         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 639         if (ACPI_FAILURE(status))
 640                 return -ENODEV;
 641
 642         obj = buffer.pointer;
 643
 644         if (obj && obj->type == ACPI_TYPE_BUFFER)
 645                 *edid = obj;
 646         else {
 647                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 648                 status = -EFAULT;
 649                 kfree(obj);
 650         }
 651
 652         return status;
 653 }
 654
 655 /* bus */
 656
 657 /*
 658  *  Arg:
 659  *      video           : video bus device pointer
 660  *      bios_flag       :
 661  *              0.      The system BIOS should NOT automatically switch(toggle)
 662  *                      the active display output.
 663  *              1.      The system BIOS should automatically switch (toggle) the
 664  *                      active display output. No switch event.
 665  *              2.      The _DGS value should be locked.
 666  *              3.      The system BIOS should not automatically switch (toggle) the
 667  *                      active display output, but instead generate the display switch
 668  *                      event notify code.
 669  *      lcd_flag        :
 670  *              0.      The system BIOS should automatically control the brightness level
 671  *                      of the LCD when the power changes from AC to DC
 672  *              1.      The system BIOS should NOT automatically control the brightness
 673  *                      level of the LCD when the power changes from AC to DC.
 674  *  Return Value:
 675  *              -EINVAL wrong arg.
 676  */
 677
 678 static int
 679 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 680 {
 681         acpi_status status;
 682
 683         if (!video->cap._DOS)
 684                 return 0;
 685
 686         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 687                 return -EINVAL;
 688         video->dos_setting = (lcd_flag << 2) | bios_flag;
 689         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 690                                             (lcd_flag << 2) | bios_flag);
 691         if (ACPI_FAILURE(status))
 692                 return -EIO;
 693
 694         return 0;
 695 }
 696
 697 /*
 698  * Simple comparison function used to sort backlight levels.
 699  */
 700
 701 static int
 702 acpi_video_cmp_level(const void *a, const void *b)
 703 {
 704         return *(int *)a - *(int *)b;
 705 }
 706
 707 /*
 708  * Decides if _BQC/_BCQ for this system is usable
 709  *
 710  * We do this by changing the level first and then read out the current
 711  * brightness level, if the value does not match, find out if it is using
 712  * index. If not, clear the _BQC/_BCQ capability.
 713  */
 714 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 715                                 int max_level, int current_level)
 716 {
 717         struct acpi_video_device_brightness *br = device->brightness;
 718         int result;
 719         unsigned long long level;
 720         int test_level;
 721
 722         /* don't mess with existing known broken systems */
 723         if (bqc_offset_aml_bug_workaround)
 724                 return 0;
 725
 726         /*
 727          * Some systems always report current brightness level as maximum
 728          * through _BQC, we need to test another value for them.
 729          */
 730         test_level = current_level == max_level ? br->levels[3] : max_level;
 731
 732         result = acpi_video_device_lcd_set_level(device, test_level);
 733         if (result)
 734                 return result;
 735
 736         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 737         if (result)
 738                 return result;
 739
 740         if (level != test_level) {
 741                 /* buggy _BQC found, need to find out if it uses index */
 742                 if (level < br->count) {
 743                         if (br->flags._BCL_reversed)
 744                                 level = br->count - 3 - level;
 745                         if (br->levels[level + 2] == test_level)
 746                                 br->flags._BQC_use_index = 1;
 747                 }
 748
 749                 if (!br->flags._BQC_use_index)
 750                         device->cap._BQC = device->cap._BCQ = 0;
 751         }
 752
 753         return 0;
 754 }
 755
 756 int acpi_video_get_levels(struct acpi_device *device,
 757                           struct acpi_video_device_brightness **dev_br,
 758                           int *pmax_level)
 759 {
 760         union acpi_object *obj = NULL;
 761         int i, max_level = 0, count = 0, level_ac_battery = 0;
 762         union acpi_object *o;
 763         struct acpi_video_device_brightness *br = NULL;
 764         int result = 0;
 765         u32 value;
 766
 767         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device->handle,
 768                                                                 &obj))) {
 769                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 770                                                 "LCD brightness level\n"));
 771                 result = -ENODEV;
 772                 goto out;
 773         }
 774
 775         if (obj->package.count < 2) {
 776                 result = -EINVAL;
 777                 goto out;
 778         }
 779
 780         br = kzalloc(sizeof(*br), GFP_KERNEL);
 781         if (!br) {
 782                 printk(KERN_ERR "can't allocate memory\n");
 783                 result = -ENOMEM;
 784                 goto out;
 785         }
 786
 787         br->levels = kmalloc((obj->package.count + 2) * sizeof *(br->levels),
 788                                 GFP_KERNEL);
 789         if (!br->levels) {
 790                 result = -ENOMEM;
 791                 goto out_free;
 792         }
 793
 794         for (i = 0; i < obj->package.count; i++) {
 795                 o = (union acpi_object *)&obj->package.elements[i];
 796                 if (o->type != ACPI_TYPE_INTEGER) {
 797                         printk(KERN_ERR PREFIX "Invalid data\n");
 798                         continue;
 799                 }
 800                 value = (u32) o->integer.value;
 801                 /* Skip duplicate entries */
 802                 if (count > 2 && br->levels[count - 1] == value)
 803                         continue;
 804
 805                 br->levels[count] = value;
 806
 807                 if (br->levels[count] > max_level)
 808                         max_level = br->levels[count];
 809                 count++;
 810         }
 811
 812         /*
 813          * some buggy BIOS don't export the levels
 814          * when machine is on AC/Battery in _BCL package.
 815          * In this case, the first two elements in _BCL packages
 816          * are also supported brightness levels that OS should take care of.
 817          */
 818         for (i = 2; i < count; i++) {
 819                 if (br->levels[i] == br->levels[0])
 820                         level_ac_battery++;
 821                 if (br->levels[i] == br->levels[1])
 822                         level_ac_battery++;
 823         }
 824
 825         if (level_ac_battery < 2) {
 826                 level_ac_battery = 2 - level_ac_battery;
 827                 br->flags._BCL_no_ac_battery_levels = 1;
 828                 for (i = (count - 1 + level_ac_battery); i >= 2; i--)
 829                         br->levels[i] = br->levels[i - level_ac_battery];
 830                 count += level_ac_battery;
 831         } else if (level_ac_battery > 2)
 832                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 833
 834         /* Check if the _BCL package is in a reversed order */
 835         if (max_level == br->levels[2]) {
 836                 br->flags._BCL_reversed = 1;
 837                 sort(&br->levels[2], count - 2, sizeof(br->levels[2]),
 838                         acpi_video_cmp_level, NULL);
 839         } else if (max_level != br->levels[count - 1])
 840                 ACPI_ERROR((AE_INFO,
 841                             "Found unordered _BCL package"));
 842
 843         br->count = count;
 844         *dev_br = br;
 845         if (pmax_level)
 846                 *pmax_level = max_level;
 847
 848 out:
 849         kfree(obj);
 850         return result;
 851 out_free:
 852         kfree(br);
 853         goto out;
 854 }
 855 EXPORT_SYMBOL(acpi_video_get_levels);
 856
 857 /*
 858  *  Arg:
 859  *      device  : video output device (LCD, CRT, ..)
 860  *
 861  *  Return Value:
 862  *      Maximum brightness level
 863  *
 864  *  Allocate and initialize device->brightness.
 865  */
 866
 867 static int
 868 acpi_video_init_brightness(struct acpi_video_device *device)
 869 {
 870         int i, max_level = 0;
 871         unsigned long long level, level_old;
 872         struct acpi_video_device_brightness *br = NULL;
 873         int result = -EINVAL;
 874
 875         result = acpi_video_get_levels(device->dev, &br, &max_level);
 876         if (result)
 877                 return result;
 878         device->brightness = br;
 879
 880         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 881         br->curr = level = max_level;
 882
 883         if (!device->cap._BQC)
 884                 goto set_level;
 885
 886         result = acpi_video_device_lcd_get_level_current(device,
 887                                                          &level_old, true);
 888         if (result)
 889                 goto out_free_levels;
 890
 891         result = acpi_video_bqc_quirk(device, max_level, level_old);
 892         if (result)
 893                 goto out_free_levels;
 894         /*
 895          * cap._BQC may get cleared due to _BQC is found to be broken
 896          * in acpi_video_bqc_quirk, so check again here.
 897          */
 898         if (!device->cap._BQC)
 899                 goto set_level;
 900
 901         level = acpi_video_bqc_value_to_level(device, level_old);
 902         /*
 903          * On some buggy laptops, _BQC returns an uninitialized
 904          * value when invoked for the first time, i.e.
 905          * level_old is invalid (no matter whether it's a level
 906          * or an index). Set the backlight to max_level in this case.
 907          */
 908         for (i = 2; i < br->count; i++)
 909                 if (level == br->levels[i])
 910                         break;
 911         if (i == br->count || !level)
 912                 level = max_level;
 913
 914 set_level:
 915         result = acpi_video_device_lcd_set_level(device, level);
 916         if (result)
 917                 goto out_free_levels;
 918
 919         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 920                           "found %d brightness levels\n", br->count - 2));
 921         return 0;
 922
 923 out_free_levels:
 924         kfree(br->levels);
 925         kfree(br);
 926         device->brightness = NULL;
 927         return result;
 928 }
 929
 930 /*
 931  *  Arg:
 932  *      device  : video output device (LCD, CRT, ..)
 933  *
 934  *  Return Value:
 935  *      None
 936  *
 937  *  Find out all required AML methods defined under the output
 938  *  device.
 939  */
 940
 941 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 942 {
 943         if (acpi_has_method(device->dev->handle, "_ADR"))
 944                 device->cap._ADR = 1;
 945         if (acpi_has_method(device->dev->handle, "_BCL"))
 946                 device->cap._BCL = 1;
 947         if (acpi_has_method(device->dev->handle, "_BCM"))
 948                 device->cap._BCM = 1;
 949         if (acpi_has_method(device->dev->handle, "_BQC")) {
 950                 device->cap._BQC = 1;
 951         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
 952                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
 953                 device->cap._BCQ = 1;
 954         }
 955
 956         if (acpi_has_method(device->dev->handle, "_DDC"))
 957                 device->cap._DDC = 1;
 958 }
 959
 960 /*
 961  *  Arg:
 962  *      device  : video output device (VGA)
 963  *
 964  *  Return Value:
 965  *      None
 966  *
 967  *  Find out all required AML methods defined under the video bus device.
 968  */
 969
 970 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
 971 {
 972         if (acpi_has_method(video->device->handle, "_DOS"))
 973                 video->cap._DOS = 1;
 974         if (acpi_has_method(video->device->handle, "_DOD"))
 975                 video->cap._DOD = 1;
 976         if (acpi_has_method(video->device->handle, "_ROM"))
 977                 video->cap._ROM = 1;
 978         if (acpi_has_method(video->device->handle, "_GPD"))
 979                 video->cap._GPD = 1;
 980         if (acpi_has_method(video->device->handle, "_SPD"))
 981                 video->cap._SPD = 1;
 982         if (acpi_has_method(video->device->handle, "_VPO"))
 983                 video->cap._VPO = 1;
 984 }
 985
 986 /*
 987  * Check whether the video bus device has required AML method to
 988  * support the desired features
 989  */
 990
 991 static int acpi_video_bus_check(struct acpi_video_bus *video)
 992 {
 993         acpi_status status = -ENOENT;
 994         struct pci_dev *dev;
 995
 996         if (!video)
 997                 return -EINVAL;
 998
 999         dev = acpi_get_pci_dev(video->device->handle);
1000         if (!dev)
1001                 return -ENODEV;
1002         pci_dev_put(dev);
1003
1004         /*
1005          * Since there is no HID, CID and so on for VGA driver, we have
1006          * to check well known required nodes.
1007          */
1008
1009         /* Does this device support video switching? */
1010         if (video->cap._DOS || video->cap._DOD) {
1011                 if (!video->cap._DOS) {
1012                         printk(KERN_WARNING FW_BUG
1013                                 "ACPI(%s) defines _DOD but not _DOS\n",
1014                                 acpi_device_bid(video->device));
1015                 }
1016                 video->flags.multihead = 1;
1017                 status = 0;
1018         }
1019
1020         /* Does this device support retrieving a video ROM? */
1021         if (video->cap._ROM) {
1022                 video->flags.rom = 1;
1023                 status = 0;
1024         }
1025
1026         /* Does this device support configuring which video device to POST? */
1027         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1028                 video->flags.post = 1;
1029                 status = 0;
1030         }
1031
1032         return status;
1033 }
1034
1035 /*
1036  * --------------------------------------------------------------------------
1037  *                               Driver Interface
1038  * --------------------------------------------------------------------------
1039  */
1040
1041 /* device interface */
1042 static struct acpi_video_device_attrib *
1043 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1044 {
1045         struct acpi_video_enumerated_device *ids;
1046         int i;
1047
1048         for (i = 0; i < video->attached_count; i++) {
1049                 ids = &video->attached_array[i];
1050                 if ((ids->value.int_val & 0xffff) == device_id)
1051                         return &ids->value.attrib;
1052         }
1053
1054         return NULL;
1055 }
1056
1057 static int
1058 acpi_video_get_device_type(struct acpi_video_bus *video,
1059                            unsigned long device_id)
1060 {
1061         struct acpi_video_enumerated_device *ids;
1062         int i;
1063
1064         for (i = 0; i < video->attached_count; i++) {
1065                 ids = &video->attached_array[i];
1066                 if ((ids->value.int_val & 0xffff) == device_id)
1067                         return ids->value.int_val;
1068         }
1069
1070         return 0;
1071 }
1072
1073 static int
1074 acpi_video_bus_get_one_device(struct acpi_device *device,
1075                               struct acpi_video_bus *video)
1076 {
1077         unsigned long long device_id;
1078         int status, device_type;
1079         struct acpi_video_device *data;
1080         struct acpi_video_device_attrib *attribute;
1081
1082         status =
1083             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1084         /* Some device omits _ADR, we skip them instead of fail */
1085         if (ACPI_FAILURE(status))
1086                 return 0;
1087
1088         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1089         if (!data)
1090                 return -ENOMEM;
1091
1092         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1093         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1094         device->driver_data = data;
1095
1096         data->device_id = device_id;
1097         data->video = video;
1098         data->dev = device;
1099         INIT_DELAYED_WORK(&data->switch_brightness_work,
1100                           acpi_video_switch_brightness);
1101
1102         attribute = acpi_video_get_device_attr(video, device_id);
1103
1104         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1105                 switch (attribute->display_type) {
1106                 case ACPI_VIDEO_DISPLAY_CRT:
1107                         data->flags.crt = 1;
1108                         break;
1109                 case ACPI_VIDEO_DISPLAY_TV:
1110                         data->flags.tvout = 1;
1111                         break;
1112                 case ACPI_VIDEO_DISPLAY_DVI:
1113                         data->flags.dvi = 1;
1114                         break;
1115                 case ACPI_VIDEO_DISPLAY_LCD:
1116                         data->flags.lcd = 1;
1117                         break;
1118                 default:
1119                         data->flags.unknown = 1;
1120                         break;
1121                 }
1122                 if (attribute->bios_can_detect)
1123                         data->flags.bios = 1;
1124         } else {
1125                 /* Check for legacy IDs */
1126                 device_type = acpi_video_get_device_type(video, device_id);
1127                 /* Ignore bits 16 and 18-20 */
1128                 switch (device_type & 0xffe2ffff) {
1129                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1130                         data->flags.crt = 1;
1131                         break;
1132                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1133                         data->flags.lcd = 1;
1134                         break;
1135                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1136                         data->flags.tvout = 1;
1137                         break;
1138                 default:
1139                         data->flags.unknown = 1;
1140                 }
1141         }
1142
1143         acpi_video_device_bind(video, data);
1144         acpi_video_device_find_cap(data);
1145
1146         mutex_lock(&video->device_list_lock);
1147         list_add_tail(&data->entry, &video->video_device_list);
1148         mutex_unlock(&video->device_list_lock);
1149
1150         return status;
1151 }
1152
1153 /*
1154  *  Arg:
1155  *      video   : video bus device
1156  *
1157  *  Return:
1158  *      none
1159  *
1160  *  Enumerate the video device list of the video bus,
1161  *  bind the ids with the corresponding video devices
1162  *  under the video bus.
1163  */
1164
1165 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1166 {
1167         struct acpi_video_device *dev;
1168
1169         mutex_lock(&video->device_list_lock);
1170
1171         list_for_each_entry(dev, &video->video_device_list, entry)
1172                 acpi_video_device_bind(video, dev);
1173
1174         mutex_unlock(&video->device_list_lock);
1175 }
1176
1177 /*
1178  *  Arg:
1179  *      video   : video bus device
1180  *      device  : video output device under the video
1181  *              bus
1182  *
1183  *  Return:
1184  *      none
1185  *
1186  *  Bind the ids with the corresponding video devices
1187  *  under the video bus.
1188  */
1189
1190 static void
1191 acpi_video_device_bind(struct acpi_video_bus *video,
1192                        struct acpi_video_device *device)
1193 {
1194         struct acpi_video_enumerated_device *ids;
1195         int i;
1196
1197         for (i = 0; i < video->attached_count; i++) {
1198                 ids = &video->attached_array[i];
1199                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1200                         ids->bind_info = device;
1201                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1202                 }
1203         }
1204 }
1205
1206 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1207 {
1208         struct acpi_video_bus *video = device->video;
1209         int i;
1210
1211         /*
1212          * If we have a broken _DOD or we have more than 8 output devices
1213          * under the graphics controller node that we can't proper deal with
1214          * in the operation region code currently, no need to test.
1215          */
1216         if (!video->attached_count || video->child_count > 8)
1217                 return true;
1218
1219         for (i = 0; i < video->attached_count; i++) {
1220                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1221                     (device->device_id & 0xfff))
1222                         return true;
1223         }
1224
1225         return false;
1226 }
1227
1228 /*
1229  *  Arg:
1230  *      video   : video bus device
1231  *
1232  *  Return:
1233  *      < 0     : error
1234  *
1235  *  Call _DOD to enumerate all devices attached to display adapter
1236  *
1237  */
1238
1239 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1240 {
1241         int status;
1242         int count;
1243         int i;
1244         struct acpi_video_enumerated_device *active_list;
1245         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1246         union acpi_object *dod = NULL;
1247         union acpi_object *obj;
1248
1249         if (!video->cap._DOD)
1250                 return AE_NOT_EXIST;
1251
1252         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1253         if (!ACPI_SUCCESS(status)) {
1254                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1255                 return status;
1256         }
1257
1258         dod = buffer.pointer;
1259         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1260                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1261                 status = -EFAULT;
1262                 goto out;
1263         }
1264
1265         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1266                           dod->package.count));
1267
1268         active_list = kcalloc(1 + dod->package.count,
1269                               sizeof(struct acpi_video_enumerated_device),
1270                               GFP_KERNEL);
1271         if (!active_list) {
1272                 status = -ENOMEM;
1273                 goto out;
1274         }
1275
1276         count = 0;
1277         for (i = 0; i < dod->package.count; i++) {
1278                 obj = &dod->package.elements[i];
1279
1280                 if (obj->type != ACPI_TYPE_INTEGER) {
1281                         printk(KERN_ERR PREFIX
1282                                 "Invalid _DOD data in element %d\n", i);
1283                         continue;
1284                 }
1285
1286                 active_list[count].value.int_val = obj->integer.value;
1287                 active_list[count].bind_info = NULL;
1288                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1289                                   (int)obj->integer.value));
1290                 count++;
1291         }
1292
1293         kfree(video->attached_array);
1294
1295         video->attached_array = active_list;
1296         video->attached_count = count;
1297
1298 out:
1299         kfree(buffer.pointer);
1300         return status;
1301 }
1302
1303 static int
1304 acpi_video_get_next_level(struct acpi_video_device *device,
1305                           u32 level_current, u32 event)
1306 {
1307         int min, max, min_above, max_below, i, l, delta = 255;
1308         max = max_below = 0;
1309         min = min_above = 255;
1310         /* Find closest level to level_current */
1311         for (i = 2; i < device->brightness->count; i++) {
1312                 l = device->brightness->levels[i];
1313                 if (abs(l - level_current) < abs(delta)) {
1314                         delta = l - level_current;
1315                         if (!delta)
1316                                 break;
1317                 }
1318         }
1319         /* Ajust level_current to closest available level */
1320         level_current += delta;
1321         for (i = 2; i < device->brightness->count; i++) {
1322                 l = device->brightness->levels[i];
1323                 if (l < min)
1324                         min = l;
1325                 if (l > max)
1326                         max = l;
1327                 if (l < min_above && l > level_current)
1328                         min_above = l;
1329                 if (l > max_below && l < level_current)
1330                         max_below = l;
1331         }
1332
1333         switch (event) {
1334         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1335                 return (level_current < max) ? min_above : min;
1336         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1337                 return (level_current < max) ? min_above : max;
1338         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1339                 return (level_current > min) ? max_below : min;
1340         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1341         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1342                 return 0;
1343         default:
1344                 return level_current;
1345         }
1346 }
1347
1348 static void
1349 acpi_video_switch_brightness(struct work_struct *work)
1350 {
1351         struct acpi_video_device *device = container_of(to_delayed_work(work),
1352                              struct acpi_video_device, switch_brightness_work);
1353         unsigned long long level_current, level_next;
1354         int event = device->switch_brightness_event;
1355         int result = -EINVAL;
1356
1357         /* no warning message if acpi_backlight=vendor or a quirk is used */
1358         if (!device->backlight)
1359                 return;
1360
1361         if (!device->brightness)
1362                 goto out;
1363
1364         result = acpi_video_device_lcd_get_level_current(device,
1365                                                          &level_current,
1366                                                          false);
1367         if (result)
1368                 goto out;
1369
1370         level_next = acpi_video_get_next_level(device, level_current, event);
1371
1372         result = acpi_video_device_lcd_set_level(device, level_next);
1373
1374         if (!result)
1375                 backlight_force_update(device->backlight,
1376                                        BACKLIGHT_UPDATE_HOTKEY);
1377
1378 out:
1379         if (result)
1380                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1381 }
1382
1383 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1384                         void **edid)
1385 {
1386         struct acpi_video_bus *video;
1387         struct acpi_video_device *video_device;
1388         union acpi_object *buffer = NULL;
1389         acpi_status status;
1390         int i, length;
1391
1392         if (!device || !acpi_driver_data(device))
1393                 return -EINVAL;
1394
1395         video = acpi_driver_data(device);
1396
1397         for (i = 0; i < video->attached_count; i++) {
1398                 video_device = video->attached_array[i].bind_info;
1399                 length = 256;
1400
1401                 if (!video_device)
1402                         continue;
1403
1404                 if (!video_device->cap._DDC)
1405                         continue;
1406
1407                 if (type) {
1408                         switch (type) {
1409                         case ACPI_VIDEO_DISPLAY_CRT:
1410                                 if (!video_device->flags.crt)
1411                                         continue;
1412                                 break;
1413                         case ACPI_VIDEO_DISPLAY_TV:
1414                                 if (!video_device->flags.tvout)
1415                                         continue;
1416                                 break;
1417                         case ACPI_VIDEO_DISPLAY_DVI:
1418                                 if (!video_device->flags.dvi)
1419                                         continue;
1420                                 break;
1421                         case ACPI_VIDEO_DISPLAY_LCD:
1422                                 if (!video_device->flags.lcd)
1423                                         continue;
1424                                 break;
1425                         }
1426                 } else if (video_device->device_id != device_id) {
1427                         continue;
1428                 }
1429
1430                 status = acpi_video_device_EDID(video_device, &buffer, length);
1431
1432                 if (ACPI_FAILURE(status) || !buffer ||
1433                     buffer->type != ACPI_TYPE_BUFFER) {
1434                         length = 128;
1435                         status = acpi_video_device_EDID(video_device, &buffer,
1436                                                         length);
1437                         if (ACPI_FAILURE(status) || !buffer ||
1438                             buffer->type != ACPI_TYPE_BUFFER) {
1439                                 continue;
1440                         }
1441                 }
1442
1443                 *edid = buffer->buffer.pointer;
1444                 return length;
1445         }
1446
1447         return -ENODEV;
1448 }
1449 EXPORT_SYMBOL(acpi_video_get_edid);
1450
1451 static int
1452 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1453                            struct acpi_device *device)
1454 {
1455         int status = 0;
1456         struct acpi_device *dev;
1457
1458         /*
1459          * There are systems where video module known to work fine regardless
1460          * of broken _DOD and ignoring returned value here doesn't cause
1461          * any issues later.
1462          */
1463         acpi_video_device_enumerate(video);
1464
1465         list_for_each_entry(dev, &device->children, node) {
1466
1467                 status = acpi_video_bus_get_one_device(dev, video);
1468                 if (status) {
1469                         dev_err(&dev->dev, "Can't attach device\n");
1470                         break;
1471                 }
1472                 video->child_count++;
1473         }
1474         return status;
1475 }
1476
1477 /* acpi_video interface */
1478
1479 /*
1480  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1481  * preform any automatic brightness change on receiving a notification.
1482  */
1483 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1484 {
1485         return acpi_video_bus_DOS(video, 0,
1486                                   acpi_osi_is_win8() ? 1 : 0);
1487 }
1488
1489 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1490 {
1491         return acpi_video_bus_DOS(video, 0,
1492                                   acpi_osi_is_win8() ? 0 : 1);
1493 }
1494
1495 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1496 {
1497         struct acpi_video_bus *video = acpi_driver_data(device);
1498         struct input_dev *input;
1499         int keycode = 0;
1500
1501         if (!video || !video->input)
1502                 return;
1503
1504         input = video->input;
1505
1506         switch (event) {
1507         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1508                                          * most likely via hotkey. */
1509                 keycode = KEY_SWITCHVIDEOMODE;
1510                 break;
1511
1512         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1513                                          * connector. */
1514                 acpi_video_device_enumerate(video);
1515                 acpi_video_device_rebind(video);
1516                 keycode = KEY_SWITCHVIDEOMODE;
1517                 break;
1518
1519         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1520                 keycode = KEY_SWITCHVIDEOMODE;
1521                 break;
1522         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1523                 keycode = KEY_VIDEO_NEXT;
1524                 break;
1525         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1526                 keycode = KEY_VIDEO_PREV;
1527                 break;
1528
1529         default:
1530                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1531                                   "Unsupported event [0x%x]\n", event));
1532                 break;
1533         }
1534
1535         if (acpi_notifier_call_chain(device, event, 0))
1536                 /* Something vetoed the keypress. */
1537                 keycode = 0;
1538
1539         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1540                 input_report_key(input, keycode, 1);
1541                 input_sync(input);
1542                 input_report_key(input, keycode, 0);
1543                 input_sync(input);
1544         }
1545
1546         return;
1547 }
1548
1549 static void brightness_switch_event(struct acpi_video_device *video_device,
1550                                     u32 event)
1551 {
1552         if (!brightness_switch_enabled)
1553                 return;
1554
1555         video_device->switch_brightness_event = event;
1556         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1557 }
1558
1559 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1560 {
1561         struct acpi_video_device *video_device = data;
1562         struct acpi_device *device = NULL;
1563         struct acpi_video_bus *bus;
1564         struct input_dev *input;
1565         int keycode = 0;
1566
1567         if (!video_device)
1568                 return;
1569
1570         device = video_device->dev;
1571         bus = video_device->video;
1572         input = bus->input;
1573
1574         switch (event) {
1575         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1576                 brightness_switch_event(video_device, event);
1577                 keycode = KEY_BRIGHTNESS_CYCLE;
1578                 break;
1579         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1580                 brightness_switch_event(video_device, event);
1581                 keycode = KEY_BRIGHTNESSUP;
1582                 break;
1583         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1584                 brightness_switch_event(video_device, event);
1585                 keycode = KEY_BRIGHTNESSDOWN;
1586                 break;
1587         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1588                 brightness_switch_event(video_device, event);
1589                 keycode = KEY_BRIGHTNESS_ZERO;
1590                 break;
1591         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1592                 brightness_switch_event(video_device, event);
1593                 keycode = KEY_DISPLAY_OFF;
1594                 break;
1595         default:
1596                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1597                                   "Unsupported event [0x%x]\n", event));
1598                 break;
1599         }
1600
1601         acpi_notifier_call_chain(device, event, 0);
1602
1603         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1604                 input_report_key(input, keycode, 1);
1605                 input_sync(input);
1606                 input_report_key(input, keycode, 0);
1607                 input_sync(input);
1608         }
1609
1610         return;
1611 }
1612
1613 static int acpi_video_resume(struct notifier_block *nb,
1614                                 unsigned long val, void *ign)
1615 {
1616         struct acpi_video_bus *video;
1617         struct acpi_video_device *video_device;
1618         int i;
1619
1620         switch (val) {
1621         case PM_HIBERNATION_PREPARE:
1622         case PM_SUSPEND_PREPARE:
1623         case PM_RESTORE_PREPARE:
1624                 return NOTIFY_DONE;
1625         }
1626
1627         video = container_of(nb, struct acpi_video_bus, pm_nb);
1628
1629         dev_info(&video->device->dev, "Restoring backlight state\n");
1630
1631         for (i = 0; i < video->attached_count; i++) {
1632                 video_device = video->attached_array[i].bind_info;
1633                 if (video_device && video_device->brightness)
1634                         acpi_video_device_lcd_set_level(video_device,
1635                                         video_device->brightness->curr);
1636         }
1637
1638         return NOTIFY_OK;
1639 }
1640
1641 static acpi_status
1642 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1643                         void **return_value)
1644 {
1645         struct acpi_device *device = context;
1646         struct acpi_device *sibling;
1647         int result;
1648
1649         if (handle == device->handle)
1650                 return AE_CTRL_TERMINATE;
1651
1652         result = acpi_bus_get_device(handle, &sibling);
1653         if (result)
1654                 return AE_OK;
1655
1656         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1657                         return AE_ALREADY_EXISTS;
1658
1659         return AE_OK;
1660 }
1661
1662 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1663 {
1664         struct backlight_properties props;
1665         struct pci_dev *pdev;
1666         acpi_handle acpi_parent;
1667         struct device *parent = NULL;
1668         int result;
1669         static int count;
1670         char *name;
1671
1672         result = acpi_video_init_brightness(device);
1673         if (result)
1674                 return;
1675
1676         if (disable_backlight_sysfs_if > 0)
1677                 return;
1678
1679         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1680         if (!name)
1681                 return;
1682         count++;
1683
1684         acpi_get_parent(device->dev->handle, &acpi_parent);
1685
1686         pdev = acpi_get_pci_dev(acpi_parent);
1687         if (pdev) {
1688                 parent = &pdev->dev;
1689                 pci_dev_put(pdev);
1690         }
1691
1692         memset(&props, 0, sizeof(struct backlight_properties));
1693         props.type = BACKLIGHT_FIRMWARE;
1694         props.max_brightness = device->brightness->count - 3;
1695         device->backlight = backlight_device_register(name,
1696                                                       parent,
1697                                                       device,
1698                                                       &acpi_backlight_ops,
1699                                                       &props);
1700         kfree(name);
1701         if (IS_ERR(device->backlight)) {
1702                 device->backlight = NULL;
1703                 return;
1704         }
1705
1706         /*
1707          * Save current brightness level in case we have to restore it
1708          * before acpi_video_device_lcd_set_level() is called next time.
1709          */
1710         device->backlight->props.brightness =
1711                         acpi_video_get_brightness(device->backlight);
1712
1713         device->cooling_dev = thermal_cooling_device_register("LCD",
1714                                 device->dev, &video_cooling_ops);
1715         if (IS_ERR(device->cooling_dev)) {
1716                 /*
1717                  * Set cooling_dev to NULL so we don't crash trying to free it.
1718                  * Also, why the hell we are returning early and not attempt to
1719                  * register video output if cooling device registration failed?
1720                  * -- dtor
1721                  */
1722                 device->cooling_dev = NULL;
1723                 return;
1724         }
1725
1726         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1727                  device->cooling_dev->id);
1728         result = sysfs_create_link(&device->dev->dev.kobj,
1729                         &device->cooling_dev->device.kobj,
1730                         "thermal_cooling");
1731         if (result)
1732                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1733         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1734                         &device->dev->dev.kobj, "device");
1735         if (result)
1736                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1737 }
1738
1739 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1740 {
1741         struct acpi_video_device *dev;
1742         union acpi_object *levels;
1743
1744         mutex_lock(&video->device_list_lock);
1745         list_for_each_entry(dev, &video->video_device_list, entry) {
1746                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1747                         kfree(levels);
1748         }
1749         mutex_unlock(&video->device_list_lock);
1750 }
1751
1752 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1753 {
1754         /*
1755          * Do not create backlight device for video output
1756          * device that is not in the enumerated list.
1757          */
1758         if (!acpi_video_device_in_dod(dev)) {
1759                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1760                 return false;
1761         }
1762
1763         if (only_lcd)
1764                 return dev->flags.lcd;
1765         return true;
1766 }
1767
1768 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1769 {
1770         struct acpi_video_device *dev;
1771
1772         if (video->backlight_registered)
1773                 return 0;
1774
1775         acpi_video_run_bcl_for_osi(video);
1776
1777         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1778                 return 0;
1779
1780         mutex_lock(&video->device_list_lock);
1781         list_for_each_entry(dev, &video->video_device_list, entry) {
1782                 if (acpi_video_should_register_backlight(dev))
1783                         acpi_video_dev_register_backlight(dev);
1784         }
1785         mutex_unlock(&video->device_list_lock);
1786
1787         video->backlight_registered = true;
1788
1789         video->pm_nb.notifier_call = acpi_video_resume;
1790         video->pm_nb.priority = 0;
1791         return register_pm_notifier(&video->pm_nb);
1792 }
1793
1794 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1795 {
1796         if (device->backlight) {
1797                 backlight_device_unregister(device->backlight);
1798                 device->backlight = NULL;
1799         }
1800         if (device->brightness) {
1801                 kfree(device->brightness->levels);
1802                 kfree(device->brightness);
1803                 device->brightness = NULL;
1804         }
1805         if (device->cooling_dev) {
1806                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1807                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1808                 thermal_cooling_device_unregister(device->cooling_dev);
1809                 device->cooling_dev = NULL;
1810         }
1811 }
1812
1813 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1814 {
1815         struct acpi_video_device *dev;
1816         int error;
1817
1818         if (!video->backlight_registered)
1819                 return 0;
1820
1821         error = unregister_pm_notifier(&video->pm_nb);
1822
1823         mutex_lock(&video->device_list_lock);
1824         list_for_each_entry(dev, &video->video_device_list, entry)
1825                 acpi_video_dev_unregister_backlight(dev);
1826         mutex_unlock(&video->device_list_lock);
1827
1828         video->backlight_registered = false;
1829
1830         return error;
1831 }
1832
1833 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1834 {
1835         acpi_status status;
1836         struct acpi_device *adev = device->dev;
1837
1838         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1839                                              acpi_video_device_notify, device);
1840         if (ACPI_FAILURE(status))
1841                 dev_err(&adev->dev, "Error installing notify handler\n");
1842         else
1843                 device->flags.notify = 1;
1844 }
1845
1846 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1847 {
1848         struct input_dev *input;
1849         struct acpi_video_device *dev;
1850         int error;
1851
1852         video->input = input = input_allocate_device();
1853         if (!input) {
1854                 error = -ENOMEM;
1855                 goto out;
1856         }
1857
1858         error = acpi_video_bus_start_devices(video);
1859         if (error)
1860                 goto err_free_input;
1861
1862         snprintf(video->phys, sizeof(video->phys),
1863                         "%s/video/input0", acpi_device_hid(video->device));
1864
1865         input->name = acpi_device_name(video->device);
1866         input->phys = video->phys;
1867         input->id.bustype = BUS_HOST;
1868         input->id.product = 0x06;
1869         input->dev.parent = &video->device->dev;
1870         input->evbit[0] = BIT(EV_KEY);
1871         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1872         set_bit(KEY_VIDEO_NEXT, input->keybit);
1873         set_bit(KEY_VIDEO_PREV, input->keybit);
1874         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1875         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1876         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1877         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1878         set_bit(KEY_DISPLAY_OFF, input->keybit);
1879
1880         error = input_register_device(input);
1881         if (error)
1882                 goto err_stop_dev;
1883
1884         mutex_lock(&video->device_list_lock);
1885         list_for_each_entry(dev, &video->video_device_list, entry)
1886                 acpi_video_dev_add_notify_handler(dev);
1887         mutex_unlock(&video->device_list_lock);
1888
1889         return 0;
1890
1891 err_stop_dev:
1892         acpi_video_bus_stop_devices(video);
1893 err_free_input:
1894         input_free_device(input);
1895         video->input = NULL;
1896 out:
1897         return error;
1898 }
1899
1900 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1901 {
1902         if (dev->flags.notify) {
1903                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1904                                            acpi_video_device_notify);
1905                 dev->flags.notify = 0;
1906         }
1907 }
1908
1909 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1910 {
1911         struct acpi_video_device *dev;
1912
1913         mutex_lock(&video->device_list_lock);
1914         list_for_each_entry(dev, &video->video_device_list, entry)
1915                 acpi_video_dev_remove_notify_handler(dev);
1916         mutex_unlock(&video->device_list_lock);
1917
1918         acpi_video_bus_stop_devices(video);
1919         input_unregister_device(video->input);
1920         video->input = NULL;
1921 }
1922
1923 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
1924 {
1925         struct acpi_video_device *dev, *next;
1926
1927         mutex_lock(&video->device_list_lock);
1928         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
1929                 list_del(&dev->entry);
1930                 kfree(dev);
1931         }
1932         mutex_unlock(&video->device_list_lock);
1933
1934         return 0;
1935 }
1936
1937 static int instance;
1938
1939 static int acpi_video_bus_add(struct acpi_device *device)
1940 {
1941         struct acpi_video_bus *video;
1942         int error;
1943         acpi_status status;
1944
1945         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
1946                                 device->parent->handle, 1,
1947                                 acpi_video_bus_match, NULL,
1948                                 device, NULL);
1949         if (status == AE_ALREADY_EXISTS) {
1950                 printk(KERN_WARNING FW_BUG
1951                         "Duplicate ACPI video bus devices for the"
1952                         " same VGA controller, please try module "
1953                         "parameter \"video.allow_duplicates=1\""
1954                         "if the current driver doesn't work.\n");
1955                 if (!allow_duplicates)
1956                         return -ENODEV;
1957         }
1958
1959         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
1960         if (!video)
1961                 return -ENOMEM;
1962
1963         /* a hack to fix the duplicate name "VID" problem on T61 */
1964         if (!strcmp(device->pnp.bus_id, "VID")) {
1965                 if (instance)
1966                         device->pnp.bus_id[3] = '0' + instance;
1967                 instance++;
1968         }
1969         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
1970         if (!strcmp(device->pnp.bus_id, "VGA")) {
1971                 if (instance)
1972                         device->pnp.bus_id[3] = '0' + instance;
1973                 instance++;
1974         }
1975
1976         video->device = device;
1977         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
1978         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1979         device->driver_data = video;
1980
1981         acpi_video_bus_find_cap(video);
1982         error = acpi_video_bus_check(video);
1983         if (error)
1984                 goto err_free_video;
1985
1986         mutex_init(&video->device_list_lock);
1987         INIT_LIST_HEAD(&video->video_device_list);
1988
1989         error = acpi_video_bus_get_devices(video, device);
1990         if (error)
1991                 goto err_put_video;
1992
1993         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
1994                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
1995                video->flags.multihead ? "yes" : "no",
1996                video->flags.rom ? "yes" : "no",
1997                video->flags.post ? "yes" : "no");
1998         mutex_lock(&video_list_lock);
1999         list_add_tail(&video->entry, &video_bus_head);
2000         mutex_unlock(&video_list_lock);
2001
2002         acpi_video_bus_register_backlight(video);
2003         acpi_video_bus_add_notify_handler(video);
2004
2005         return 0;
2006
2007 err_put_video:
2008         acpi_video_bus_put_devices(video);
2009         kfree(video->attached_array);
2010 err_free_video:
2011         kfree(video);
2012         device->driver_data = NULL;
2013
2014         return error;
2015 }
2016
2017 static int acpi_video_bus_remove(struct acpi_device *device)
2018 {
2019         struct acpi_video_bus *video = NULL;
2020
2021
2022         if (!device || !acpi_driver_data(device))
2023                 return -EINVAL;
2024
2025         video = acpi_driver_data(device);
2026
2027         acpi_video_bus_remove_notify_handler(video);
2028         acpi_video_bus_unregister_backlight(video);
2029         acpi_video_bus_put_devices(video);
2030
2031         mutex_lock(&video_list_lock);
2032         list_del(&video->entry);
2033         mutex_unlock(&video_list_lock);
2034
2035         kfree(video->attached_array);
2036         kfree(video);
2037
2038         return 0;
2039 }
2040
2041 static int __init is_i740(struct pci_dev *dev)
2042 {
2043         if (dev->device == 0x00D1)
2044                 return 1;
2045         if (dev->device == 0x7000)
2046                 return 1;
2047         return 0;
2048 }
2049
2050 static int __init intel_opregion_present(void)
2051 {
2052         int opregion = 0;
2053         struct pci_dev *dev = NULL;
2054         u32 address;
2055
2056         for_each_pci_dev(dev) {
2057                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2058                         continue;
2059                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2060                         continue;
2061                 /* We don't want to poke around undefined i740 registers */
2062                 if (is_i740(dev))
2063                         continue;
2064                 pci_read_config_dword(dev, 0xfc, &address);
2065                 if (!address)
2066                         continue;
2067                 opregion = 1;
2068         }
2069         return opregion;
2070 }
2071
2072 int acpi_video_register(void)
2073 {
2074         int ret = 0;
2075
2076         mutex_lock(&register_count_mutex);
2077         if (register_count) {
2078                 /*
2079                  * if the function of acpi_video_register is already called,
2080                  * don't register the acpi_vide_bus again and return no error.
2081                  */
2082                 goto leave;
2083         }
2084
2085         dmi_check_system(video_dmi_table);
2086
2087         ret = acpi_bus_register_driver(&acpi_video_bus);
2088         if (ret)
2089                 goto leave;
2090
2091         /*
2092          * When the acpi_video_bus is loaded successfully, increase
2093          * the counter reference.
2094          */
2095         register_count = 1;
2096
2097 leave:
2098         mutex_unlock(&register_count_mutex);
2099         return ret;
2100 }
2101 EXPORT_SYMBOL(acpi_video_register);
2102
2103 void acpi_video_unregister(void)
2104 {
2105         mutex_lock(&register_count_mutex);
2106         if (register_count) {
2107                 acpi_bus_unregister_driver(&acpi_video_bus);
2108                 register_count = 0;
2109         }
2110         mutex_unlock(&register_count_mutex);
2111 }
2112 EXPORT_SYMBOL(acpi_video_unregister);
2113
2114 void acpi_video_unregister_backlight(void)
2115 {
2116         struct acpi_video_bus *video;
2117
2118         mutex_lock(&register_count_mutex);
2119         if (register_count) {
2120                 mutex_lock(&video_list_lock);
2121                 list_for_each_entry(video, &video_bus_head, entry)
2122                         acpi_video_bus_unregister_backlight(video);
2123                 mutex_unlock(&video_list_lock);
2124         }
2125         mutex_unlock(&register_count_mutex);
2126 }
2127
2128 bool acpi_video_handles_brightness_key_presses(void)
2129 {
2130         bool have_video_busses;
2131
2132         mutex_lock(&video_list_lock);
2133         have_video_busses = !list_empty(&video_bus_head);
2134         mutex_unlock(&video_list_lock);
2135
2136         return have_video_busses &&
2137                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2138 }
2139 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2140
2141 /*
2142  * This is kind of nasty. Hardware using Intel chipsets may require
2143  * the video opregion code to be run first in order to initialise
2144  * state before any ACPI video calls are made. To handle this we defer
2145  * registration of the video class until the opregion code has run.
2146  */
2147
2148 static int __init acpi_video_init(void)
2149 {
2150         /*
2151          * Let the module load even if ACPI is disabled (e.g. due to
2152          * a broken BIOS) so that i915.ko can still be loaded on such
2153          * old systems without an AcpiOpRegion.
2154          *
2155          * acpi_video_register() will report -ENODEV later as well due
2156          * to acpi_disabled when i915.ko tries to register itself afterwards.
2157          */
2158         if (acpi_disabled)
2159                 return 0;
2160
2161         if (intel_opregion_present())
2162                 return 0;
2163
2164         return acpi_video_register();
2165 }
2166
2167 static void __exit acpi_video_exit(void)
2168 {
2169         acpi_video_detect_exit();
2170         acpi_video_unregister();
2171
2172         return;
2173 }
2174
2175 module_init(acpi_video_init);
2176 module_exit(acpi_video_exit);