drivers/acpi/acpi_video.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  video.c - ACPI Video Driver
   4  *
   5  *  Copyright (C) 2004 Luming Yu <[email protected]>
   6  *  Copyright (C) 2004 Bruno Ducrot <[email protected]>
   7  *  Copyright (C) 2006 Thomas Tuttle <[email protected]>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/types.h>
  14 #include <linux/list.h>
  15 #include <linux/mutex.h>
  16 #include <linux/input.h>
  17 #include <linux/backlight.h>
  18 #include <linux/thermal.h>
  19 #include <linux/sort.h>
  20 #include <linux/pci.h>
  21 #include <linux/pci_ids.h>
  22 #include <linux/slab.h>
  23 #include <linux/dmi.h>
  24 #include <linux/suspend.h>
  25 #include <linux/acpi.h>
  26 #include <acpi/video.h>
  27 #include <linux/uaccess.h>
  28
  29 #define PREFIX "ACPI: "
  30
  31 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
  32 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  33
  34 #define MAX_NAME_LEN    20
  35
  36 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  37 ACPI_MODULE_NAME("video");
  38
  39 MODULE_AUTHOR("Bruno Ducrot");
  40 MODULE_DESCRIPTION("ACPI Video Driver");
  41 MODULE_LICENSE("GPL");
  42
  43 static bool brightness_switch_enabled = true;
  44 module_param(brightness_switch_enabled, bool, 0644);
  45
  46 /*
  47  * By default, we don't allow duplicate ACPI video bus devices
  48  * under the same VGA controller
  49  */
  50 static bool allow_duplicates;
  51 module_param(allow_duplicates, bool, 0644);
  52
  53 static int disable_backlight_sysfs_if = -1;
  54 module_param(disable_backlight_sysfs_if, int, 0444);
  55
  56 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  57 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  58 static int report_key_events = -1;
  59 module_param(report_key_events, int, 0644);
  60 MODULE_PARM_DESC(report_key_events,
  61         "0: none, 1: output changes, 2: brightness changes, 3: all");
  62
  63 static int hw_changes_brightness = -1;
  64 module_param(hw_changes_brightness, int, 0644);
  65 MODULE_PARM_DESC(hw_changes_brightness,
  66         "Set this to 1 on buggy hw which changes the brightness itself when "
  67         "a hotkey is pressed: -1: auto, 0: normal 1: hw-changes-brightness");
  68
  69 /*
  70  * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
  71  * assumed even if not actually set.
  72  */
  73 static bool device_id_scheme = false;
  74 module_param(device_id_scheme, bool, 0444);
  75
  76 static int only_lcd = -1;
  77 module_param(only_lcd, int, 0444);
  78
  79 static int register_count;
  80 static DEFINE_MUTEX(register_count_mutex);
  81 static DEFINE_MUTEX(video_list_lock);
  82 static LIST_HEAD(video_bus_head);
  83 static int acpi_video_bus_add(struct acpi_device *device);
  84 static int acpi_video_bus_remove(struct acpi_device *device);
  85 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  86 void acpi_video_detect_exit(void);
  87
  88 /*
  89  * Indices in the _BCL method response: the first two items are special,
  90  * the rest are all supported levels.
  91  *
  92  * See page 575 of the ACPI spec 3.0
  93  */
  94 enum acpi_video_level_idx {
  95         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
  96         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
  97         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
  98 };
  99
 100 static const struct acpi_device_id video_device_ids[] = {
 101         {ACPI_VIDEO_HID, 0},
 102         {"", 0},
 103 };
 104 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 105
 106 static struct acpi_driver acpi_video_bus = {
 107         .name = "video",
 108         .class = ACPI_VIDEO_CLASS,
 109         .ids = video_device_ids,
 110         .ops = {
 111                 .add = acpi_video_bus_add,
 112                 .remove = acpi_video_bus_remove,
 113                 .notify = acpi_video_bus_notify,
 114                 },
 115 };
 116
 117 struct acpi_video_bus_flags {
 118         u8 multihead:1;         /* can switch video heads */
 119         u8 rom:1;               /* can retrieve a video rom */
 120         u8 post:1;              /* can configure the head to */
 121         u8 reserved:5;
 122 };
 123
 124 struct acpi_video_bus_cap {
 125         u8 _DOS:1;              /* Enable/Disable output switching */
 126         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 127         u8 _ROM:1;              /* Get ROM Data */
 128         u8 _GPD:1;              /* Get POST Device */
 129         u8 _SPD:1;              /* Set POST Device */
 130         u8 _VPO:1;              /* Video POST Options */
 131         u8 reserved:2;
 132 };
 133
 134 struct acpi_video_device_attrib {
 135         u32 display_index:4;    /* A zero-based instance of the Display */
 136         u32 display_port_attachment:4;  /* This field differentiates the display type */
 137         u32 display_type:4;     /* Describe the specific type in use */
 138         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 139         u32 bios_can_detect:1;  /* BIOS can detect the device */
 140         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 141                                    the VGA device. */
 142         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 143         u32 reserved:10;        /* Must be 0 */
 144
 145         /*
 146          * The device ID might not actually follow the scheme described by this
 147          * struct acpi_video_device_attrib. If it does, then this bit
 148          * device_id_scheme is set; otherwise, other fields should be ignored.
 149          *
 150          * (but also see the global flag device_id_scheme)
 151          */
 152         u32 device_id_scheme:1;
 153 };
 154
 155 struct acpi_video_enumerated_device {
 156         union {
 157                 u32 int_val;
 158                 struct acpi_video_device_attrib attrib;
 159         } value;
 160         struct acpi_video_device *bind_info;
 161 };
 162
 163 struct acpi_video_bus {
 164         struct acpi_device *device;
 165         bool backlight_registered;
 166         u8 dos_setting;
 167         struct acpi_video_enumerated_device *attached_array;
 168         u8 attached_count;
 169         u8 child_count;
 170         struct acpi_video_bus_cap cap;
 171         struct acpi_video_bus_flags flags;
 172         struct list_head video_device_list;
 173         struct mutex device_list_lock;  /* protects video_device_list */
 174         struct list_head entry;
 175         struct input_dev *input;
 176         char phys[32];  /* for input device */
 177         struct notifier_block pm_nb;
 178 };
 179
 180 struct acpi_video_device_flags {
 181         u8 crt:1;
 182         u8 lcd:1;
 183         u8 tvout:1;
 184         u8 dvi:1;
 185         u8 bios:1;
 186         u8 unknown:1;
 187         u8 notify:1;
 188         u8 reserved:1;
 189 };
 190
 191 struct acpi_video_device_cap {
 192         u8 _ADR:1;              /* Return the unique ID */
 193         u8 _BCL:1;              /* Query list of brightness control levels supported */
 194         u8 _BCM:1;              /* Set the brightness level */
 195         u8 _BQC:1;              /* Get current brightness level */
 196         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 197         u8 _DDC:1;              /* Return the EDID for this device */
 198 };
 199
 200 struct acpi_video_device {
 201         unsigned long device_id;
 202         struct acpi_video_device_flags flags;
 203         struct acpi_video_device_cap cap;
 204         struct list_head entry;
 205         struct delayed_work switch_brightness_work;
 206         int switch_brightness_event;
 207         struct acpi_video_bus *video;
 208         struct acpi_device *dev;
 209         struct acpi_video_device_brightness *brightness;
 210         struct backlight_device *backlight;
 211         struct thermal_cooling_device *cooling_dev;
 212 };
 213
 214 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 215 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 216 static void acpi_video_device_bind(struct acpi_video_bus *video,
 217                                    struct acpi_video_device *device);
 218 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 219 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 220                         int level);
 221 static int acpi_video_device_lcd_get_level_current(
 222                         struct acpi_video_device *device,
 223                         unsigned long long *level, bool raw);
 224 static int acpi_video_get_next_level(struct acpi_video_device *device,
 225                                      u32 level_current, u32 event);
 226 static void acpi_video_switch_brightness(struct work_struct *work);
 227
 228 /* backlight device sysfs support */
 229 static int acpi_video_get_brightness(struct backlight_device *bd)
 230 {
 231         unsigned long long cur_level;
 232         int i;
 233         struct acpi_video_device *vd = bl_get_data(bd);
 234
 235         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 236                 return -EINVAL;
 237         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 238                 if (vd->brightness->levels[i] == cur_level)
 239                         return i - ACPI_VIDEO_FIRST_LEVEL;
 240         }
 241         return 0;
 242 }
 243
 244 static int acpi_video_set_brightness(struct backlight_device *bd)
 245 {
 246         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 247         struct acpi_video_device *vd = bl_get_data(bd);
 248
 249         cancel_delayed_work(&vd->switch_brightness_work);
 250         return acpi_video_device_lcd_set_level(vd,
 251                                 vd->brightness->levels[request_level]);
 252 }
 253
 254 static const struct backlight_ops acpi_backlight_ops = {
 255         .get_brightness = acpi_video_get_brightness,
 256         .update_status  = acpi_video_set_brightness,
 257 };
 258
 259 /* thermal cooling device callbacks */
 260 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 261                                unsigned long *state)
 262 {
 263         struct acpi_device *device = cooling_dev->devdata;
 264         struct acpi_video_device *video = acpi_driver_data(device);
 265
 266         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 267         return 0;
 268 }
 269
 270 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 271                                unsigned long *state)
 272 {
 273         struct acpi_device *device = cooling_dev->devdata;
 274         struct acpi_video_device *video = acpi_driver_data(device);
 275         unsigned long long level;
 276         int offset;
 277
 278         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 279                 return -EINVAL;
 280         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 281              offset++)
 282                 if (level == video->brightness->levels[offset]) {
 283                         *state = video->brightness->count - offset - 1;
 284                         return 0;
 285                 }
 286
 287         return -EINVAL;
 288 }
 289
 290 static int
 291 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 292 {
 293         struct acpi_device *device = cooling_dev->devdata;
 294         struct acpi_video_device *video = acpi_driver_data(device);
 295         int level;
 296
 297         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 298                 return -EINVAL;
 299
 300         state = video->brightness->count - state;
 301         level = video->brightness->levels[state - 1];
 302         return acpi_video_device_lcd_set_level(video, level);
 303 }
 304
 305 static const struct thermal_cooling_device_ops video_cooling_ops = {
 306         .get_max_state = video_get_max_state,
 307         .get_cur_state = video_get_cur_state,
 308         .set_cur_state = video_set_cur_state,
 309 };
 310
 311 /*
 312  * --------------------------------------------------------------------------
 313  *                             Video Management
 314  * --------------------------------------------------------------------------
 315  */
 316
 317 static int
 318 acpi_video_device_lcd_query_levels(acpi_handle handle,
 319                                    union acpi_object **levels)
 320 {
 321         int status;
 322         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 323         union acpi_object *obj;
 324
 325
 326         *levels = NULL;
 327
 328         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 329         if (!ACPI_SUCCESS(status))
 330                 return status;
 331         obj = (union acpi_object *)buffer.pointer;
 332         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 333                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 334                 status = -EFAULT;
 335                 goto err;
 336         }
 337
 338         *levels = obj;
 339
 340         return 0;
 341
 342 err:
 343         kfree(buffer.pointer);
 344
 345         return status;
 346 }
 347
 348 static int
 349 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 350 {
 351         int status;
 352         int state;
 353
 354         status = acpi_execute_simple_method(device->dev->handle,
 355                                             "_BCM", level);
 356         if (ACPI_FAILURE(status)) {
 357                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 358                 return -EIO;
 359         }
 360
 361         device->brightness->curr = level;
 362         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 363              state++)
 364                 if (level == device->brightness->levels[state]) {
 365                         if (device->backlight)
 366                                 device->backlight->props.brightness =
 367                                         state - ACPI_VIDEO_FIRST_LEVEL;
 368                         return 0;
 369                 }
 370
 371         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 372         return -EINVAL;
 373 }
 374
 375 /*
 376  * For some buggy _BQC methods, we need to add a constant value to
 377  * the _BQC return value to get the actual current brightness level
 378  */
 379
 380 static int bqc_offset_aml_bug_workaround;
 381 static int video_set_bqc_offset(const struct dmi_system_id *d)
 382 {
 383         bqc_offset_aml_bug_workaround = 9;
 384         return 0;
 385 }
 386
 387 static int video_disable_backlight_sysfs_if(
 388         const struct dmi_system_id *d)
 389 {
 390         if (disable_backlight_sysfs_if == -1)
 391                 disable_backlight_sysfs_if = 1;
 392         return 0;
 393 }
 394
 395 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 396 {
 397         device_id_scheme = true;
 398         return 0;
 399 }
 400
 401 static int video_enable_only_lcd(const struct dmi_system_id *d)
 402 {
 403         only_lcd = true;
 404         return 0;
 405 }
 406
 407 static int video_set_report_key_events(const struct dmi_system_id *id)
 408 {
 409         if (report_key_events == -1)
 410                 report_key_events = (uintptr_t)id->driver_data;
 411         return 0;
 412 }
 413
 414 static int video_hw_changes_brightness(
 415         const struct dmi_system_id *d)
 416 {
 417         if (hw_changes_brightness == -1)
 418                 hw_changes_brightness = 1;
 419         return 0;
 420 }
 421
 422 static const struct dmi_system_id video_dmi_table[] = {
 423         /*
 424          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 425          */
 426         {
 427          .callback = video_set_bqc_offset,
 428          .ident = "Acer Aspire 5720",
 429          .matches = {
 430                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 431                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 432                 },
 433         },
 434         {
 435          .callback = video_set_bqc_offset,
 436          .ident = "Acer Aspire 5710Z",
 437          .matches = {
 438                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 439                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 440                 },
 441         },
 442         {
 443          .callback = video_set_bqc_offset,
 444          .ident = "eMachines E510",
 445          .matches = {
 446                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 447                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 448                 },
 449         },
 450         {
 451          .callback = video_set_bqc_offset,
 452          .ident = "Acer Aspire 5315",
 453          .matches = {
 454                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 455                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 456                 },
 457         },
 458         {
 459          .callback = video_set_bqc_offset,
 460          .ident = "Acer Aspire 7720",
 461          .matches = {
 462                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 463                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 464                 },
 465         },
 466
 467         /*
 468          * Some machines have a broken acpi-video interface for brightness
 469          * control, but still need an acpi_video_device_lcd_set_level() call
 470          * on resume to turn the backlight power on.  We Enable backlight
 471          * control on these systems, but do not register a backlight sysfs
 472          * as brightness control does not work.
 473          */
 474         {
 475          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 476          .callback = video_disable_backlight_sysfs_if,
 477          .ident = "Toshiba Portege R700",
 478          .matches = {
 479                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 480                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 481                 },
 482         },
 483         {
 484          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 485          .callback = video_disable_backlight_sysfs_if,
 486          .ident = "Toshiba Portege R830",
 487          .matches = {
 488                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 489                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 490                 },
 491         },
 492         {
 493          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 494          .callback = video_disable_backlight_sysfs_if,
 495          .ident = "Toshiba Satellite R830",
 496          .matches = {
 497                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 498                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 499                 },
 500         },
 501         /*
 502          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 503          * but the IDs actually follow the Device ID Scheme.
 504          */
 505         {
 506          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 507          .callback = video_set_device_id_scheme,
 508          .ident = "ESPRIMO Mobile M9410",
 509          .matches = {
 510                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 511                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 512                 },
 513         },
 514         /*
 515          * Some machines have multiple video output devices, but only the one
 516          * that is the type of LCD can do the backlight control so we should not
 517          * register backlight interface for other video output devices.
 518          */
 519         {
 520          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 521          .callback = video_enable_only_lcd,
 522          .ident = "ESPRIMO Mobile M9410",
 523          .matches = {
 524                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 525                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 526                 },
 527         },
 528         /*
 529          * Some machines report wrong key events on the acpi-bus, suppress
 530          * key event reporting on these.  Note this is only intended to work
 531          * around events which are plain wrong. In some cases we get double
 532          * events, in this case acpi-video is considered the canonical source
 533          * and the events from the other source should be filtered. E.g.
 534          * by calling acpi_video_handles_brightness_key_presses() from the
 535          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 536          */
 537         {
 538          .callback = video_set_report_key_events,
 539          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 540          .ident = "Dell Vostro V131",
 541          .matches = {
 542                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 543                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 544                 },
 545         },
 546         /*
 547          * Some machines change the brightness themselves when a brightness
 548          * hotkey gets pressed, despite us telling them not to. In this case
 549          * acpi_video_device_notify() should only call backlight_force_update(
 550          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 551          */
 552         {
 553          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 554          .callback = video_hw_changes_brightness,
 555          .ident = "Packard Bell EasyNote MZ35",
 556          .matches = {
 557                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 558                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 559                 },
 560         },
 561         {}
 562 };
 563
 564 static unsigned long long
 565 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 566                               unsigned long long bqc_value)
 567 {
 568         unsigned long long level;
 569
 570         if (device->brightness->flags._BQC_use_index) {
 571                 /*
 572                  * _BQC returns an index that doesn't account for the first 2
 573                  * items with special meaning (see enum acpi_video_level_idx),
 574                  * so we need to compensate for that by offsetting ourselves
 575                  */
 576                 if (device->brightness->flags._BCL_reversed)
 577                         bqc_value = device->brightness->count -
 578                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 579
 580                 level = device->brightness->levels[bqc_value +
 581                                                    ACPI_VIDEO_FIRST_LEVEL];
 582         } else {
 583                 level = bqc_value;
 584         }
 585
 586         level += bqc_offset_aml_bug_workaround;
 587
 588         return level;
 589 }
 590
 591 static int
 592 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 593                                         unsigned long long *level, bool raw)
 594 {
 595         acpi_status status = AE_OK;
 596         int i;
 597
 598         if (device->cap._BQC || device->cap._BCQ) {
 599                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 600
 601                 status = acpi_evaluate_integer(device->dev->handle, buf,
 602                                                 NULL, level);
 603                 if (ACPI_SUCCESS(status)) {
 604                         if (raw) {
 605                                 /*
 606                                  * Caller has indicated he wants the raw
 607                                  * value returned by _BQC, so don't furtherly
 608                                  * mess with the value.
 609                                  */
 610                                 return 0;
 611                         }
 612
 613                         *level = acpi_video_bqc_value_to_level(device, *level);
 614
 615                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 616                              i < device->brightness->count; i++)
 617                                 if (device->brightness->levels[i] == *level) {
 618                                         device->brightness->curr = *level;
 619                                         return 0;
 620                                 }
 621                         /*
 622                          * BQC returned an invalid level.
 623                          * Stop using it.
 624                          */
 625                         ACPI_WARNING((AE_INFO,
 626                                       "%s returned an invalid level",
 627                                       buf));
 628                         device->cap._BQC = device->cap._BCQ = 0;
 629                 } else {
 630                         /*
 631                          * Fixme:
 632                          * should we return an error or ignore this failure?
 633                          * dev->brightness->curr is a cached value which stores
 634                          * the correct current backlight level in most cases.
 635                          * ACPI video backlight still works w/ buggy _BQC.
 636                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 637                          */
 638                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 639                         device->cap._BQC = device->cap._BCQ = 0;
 640                 }
 641         }
 642
 643         *level = device->brightness->curr;
 644         return 0;
 645 }
 646
 647 static int
 648 acpi_video_device_EDID(struct acpi_video_device *device,
 649                        union acpi_object **edid, ssize_t length)
 650 {
 651         int status;
 652         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 653         union acpi_object *obj;
 654         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 655         struct acpi_object_list args = { 1, &arg0 };
 656
 657
 658         *edid = NULL;
 659
 660         if (!device)
 661                 return -ENODEV;
 662         if (length == 128)
 663                 arg0.integer.value = 1;
 664         else if (length == 256)
 665                 arg0.integer.value = 2;
 666         else
 667                 return -EINVAL;
 668
 669         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 670         if (ACPI_FAILURE(status))
 671                 return -ENODEV;
 672
 673         obj = buffer.pointer;
 674
 675         if (obj && obj->type == ACPI_TYPE_BUFFER)
 676                 *edid = obj;
 677         else {
 678                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 679                 status = -EFAULT;
 680                 kfree(obj);
 681         }
 682
 683         return status;
 684 }
 685
 686 /* bus */
 687
 688 /*
 689  *  Arg:
 690  *      video           : video bus device pointer
 691  *      bios_flag       :
 692  *              0.      The system BIOS should NOT automatically switch(toggle)
 693  *                      the active display output.
 694  *              1.      The system BIOS should automatically switch (toggle) the
 695  *                      active display output. No switch event.
 696  *              2.      The _DGS value should be locked.
 697  *              3.      The system BIOS should not automatically switch (toggle) the
 698  *                      active display output, but instead generate the display switch
 699  *                      event notify code.
 700  *      lcd_flag        :
 701  *              0.      The system BIOS should automatically control the brightness level
 702  *                      of the LCD when the power changes from AC to DC
 703  *              1.      The system BIOS should NOT automatically control the brightness
 704  *                      level of the LCD when the power changes from AC to DC.
 705  *  Return Value:
 706  *              -EINVAL wrong arg.
 707  */
 708
 709 static int
 710 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 711 {
 712         acpi_status status;
 713
 714         if (!video->cap._DOS)
 715                 return 0;
 716
 717         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 718                 return -EINVAL;
 719         video->dos_setting = (lcd_flag << 2) | bios_flag;
 720         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 721                                             (lcd_flag << 2) | bios_flag);
 722         if (ACPI_FAILURE(status))
 723                 return -EIO;
 724
 725         return 0;
 726 }
 727
 728 /*
 729  * Simple comparison function used to sort backlight levels.
 730  */
 731
 732 static int
 733 acpi_video_cmp_level(const void *a, const void *b)
 734 {
 735         return *(int *)a - *(int *)b;
 736 }
 737
 738 /*
 739  * Decides if _BQC/_BCQ for this system is usable
 740  *
 741  * We do this by changing the level first and then read out the current
 742  * brightness level, if the value does not match, find out if it is using
 743  * index. If not, clear the _BQC/_BCQ capability.
 744  */
 745 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 746                                 int max_level, int current_level)
 747 {
 748         struct acpi_video_device_brightness *br = device->brightness;
 749         int result;
 750         unsigned long long level;
 751         int test_level;
 752
 753         /* don't mess with existing known broken systems */
 754         if (bqc_offset_aml_bug_workaround)
 755                 return 0;
 756
 757         /*
 758          * Some systems always report current brightness level as maximum
 759          * through _BQC, we need to test another value for them. However,
 760          * there is a subtlety:
 761          *
 762          * If the _BCL package ordering is descending, the first level
 763          * (br->levels[2]) is likely to be 0, and if the number of levels
 764          * matches the number of steps, we might confuse a returned level to
 765          * mean the index.
 766          *
 767          * For example:
 768          *
 769          *     current_level = max_level = 100
 770          *     test_level = 0
 771          *     returned level = 100
 772          *
 773          * In this case 100 means the level, not the index, and _BCM failed.
 774          * Still, if the _BCL package ordering is descending, the index of
 775          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 776          *
 777          * This causes all _BQC calls to return bogus values causing weird
 778          * behavior from the user's perspective.  For example:
 779          *
 780          * xbacklight -set 10; xbacklight -set 20;
 781          *
 782          * would flash to 90% and then slowly down to the desired level (20).
 783          *
 784          * The solution is simple; test anything other than the first level
 785          * (e.g. 1).
 786          */
 787         test_level = current_level == max_level
 788                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 789                 : max_level;
 790
 791         result = acpi_video_device_lcd_set_level(device, test_level);
 792         if (result)
 793                 return result;
 794
 795         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 796         if (result)
 797                 return result;
 798
 799         if (level != test_level) {
 800                 /* buggy _BQC found, need to find out if it uses index */
 801                 if (level < br->count) {
 802                         if (br->flags._BCL_reversed)
 803                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 804                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 805                                 br->flags._BQC_use_index = 1;
 806                 }
 807
 808                 if (!br->flags._BQC_use_index)
 809                         device->cap._BQC = device->cap._BCQ = 0;
 810         }
 811
 812         return 0;
 813 }
 814
 815 int acpi_video_get_levels(struct acpi_device *device,
 816                           struct acpi_video_device_brightness **dev_br,
 817                           int *pmax_level)
 818 {
 819         union acpi_object *obj = NULL;
 820         int i, max_level = 0, count = 0, level_ac_battery = 0;
 821         union acpi_object *o;
 822         struct acpi_video_device_brightness *br = NULL;
 823         int result = 0;
 824         u32 value;
 825
 826         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device->handle,
 827                                                                 &obj))) {
 828                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 829                                                 "LCD brightness level\n"));
 830                 result = -ENODEV;
 831                 goto out;
 832         }
 833
 834         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 835                 result = -EINVAL;
 836                 goto out;
 837         }
 838
 839         br = kzalloc(sizeof(*br), GFP_KERNEL);
 840         if (!br) {
 841                 printk(KERN_ERR "can't allocate memory\n");
 842                 result = -ENOMEM;
 843                 goto out;
 844         }
 845
 846         /*
 847          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 848          * in order to account for buggy BIOS which don't export the first two
 849          * special levels (see below)
 850          */
 851         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 852                                    sizeof(*br->levels),
 853                                    GFP_KERNEL);
 854         if (!br->levels) {
 855                 result = -ENOMEM;
 856                 goto out_free;
 857         }
 858
 859         for (i = 0; i < obj->package.count; i++) {
 860                 o = (union acpi_object *)&obj->package.elements[i];
 861                 if (o->type != ACPI_TYPE_INTEGER) {
 862                         printk(KERN_ERR PREFIX "Invalid data\n");
 863                         continue;
 864                 }
 865                 value = (u32) o->integer.value;
 866                 /* Skip duplicate entries */
 867                 if (count > ACPI_VIDEO_FIRST_LEVEL
 868                     && br->levels[count - 1] == value)
 869                         continue;
 870
 871                 br->levels[count] = value;
 872
 873                 if (br->levels[count] > max_level)
 874                         max_level = br->levels[count];
 875                 count++;
 876         }
 877
 878         /*
 879          * some buggy BIOS don't export the levels
 880          * when machine is on AC/Battery in _BCL package.
 881          * In this case, the first two elements in _BCL packages
 882          * are also supported brightness levels that OS should take care of.
 883          */
 884         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 885                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 886                         level_ac_battery++;
 887                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 888                         level_ac_battery++;
 889         }
 890
 891         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 892                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 893                 br->flags._BCL_no_ac_battery_levels = 1;
 894                 for (i = (count - 1 + level_ac_battery);
 895                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 896                         br->levels[i] = br->levels[i - level_ac_battery];
 897                 count += level_ac_battery;
 898         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 899                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 900
 901         /* Check if the _BCL package is in a reversed order */
 902         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 903                 br->flags._BCL_reversed = 1;
 904                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 905                      count - ACPI_VIDEO_FIRST_LEVEL,
 906                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 907                      acpi_video_cmp_level, NULL);
 908         } else if (max_level != br->levels[count - 1])
 909                 ACPI_ERROR((AE_INFO,
 910                             "Found unordered _BCL package"));
 911
 912         br->count = count;
 913         *dev_br = br;
 914         if (pmax_level)
 915                 *pmax_level = max_level;
 916
 917 out:
 918         kfree(obj);
 919         return result;
 920 out_free:
 921         kfree(br);
 922         goto out;
 923 }
 924 EXPORT_SYMBOL(acpi_video_get_levels);
 925
 926 /*
 927  *  Arg:
 928  *      device  : video output device (LCD, CRT, ..)
 929  *
 930  *  Return Value:
 931  *      Maximum brightness level
 932  *
 933  *  Allocate and initialize device->brightness.
 934  */
 935
 936 static int
 937 acpi_video_init_brightness(struct acpi_video_device *device)
 938 {
 939         int i, max_level = 0;
 940         unsigned long long level, level_old;
 941         struct acpi_video_device_brightness *br = NULL;
 942         int result = -EINVAL;
 943
 944         result = acpi_video_get_levels(device->dev, &br, &max_level);
 945         if (result)
 946                 return result;
 947         device->brightness = br;
 948
 949         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 950         br->curr = level = max_level;
 951
 952         if (!device->cap._BQC)
 953                 goto set_level;
 954
 955         result = acpi_video_device_lcd_get_level_current(device,
 956                                                          &level_old, true);
 957         if (result)
 958                 goto out_free_levels;
 959
 960         result = acpi_video_bqc_quirk(device, max_level, level_old);
 961         if (result)
 962                 goto out_free_levels;
 963         /*
 964          * cap._BQC may get cleared due to _BQC is found to be broken
 965          * in acpi_video_bqc_quirk, so check again here.
 966          */
 967         if (!device->cap._BQC)
 968                 goto set_level;
 969
 970         level = acpi_video_bqc_value_to_level(device, level_old);
 971         /*
 972          * On some buggy laptops, _BQC returns an uninitialized
 973          * value when invoked for the first time, i.e.
 974          * level_old is invalid (no matter whether it's a level
 975          * or an index). Set the backlight to max_level in this case.
 976          */
 977         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 978                 if (level == br->levels[i])
 979                         break;
 980         if (i == br->count || !level)
 981                 level = max_level;
 982
 983 set_level:
 984         result = acpi_video_device_lcd_set_level(device, level);
 985         if (result)
 986                 goto out_free_levels;
 987
 988         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 989                           "found %d brightness levels\n",
 990                           br->count - ACPI_VIDEO_FIRST_LEVEL));
 991         return 0;
 992
 993 out_free_levels:
 994         kfree(br->levels);
 995         kfree(br);
 996         device->brightness = NULL;
 997         return result;
 998 }
 999
1000 /*
1001  *  Arg:
1002  *      device  : video output device (LCD, CRT, ..)
1003  *
1004  *  Return Value:
1005  *      None
1006  *
1007  *  Find out all required AML methods defined under the output
1008  *  device.
1009  */
1010
1011 static void acpi_video_device_find_cap(struct acpi_video_device *device)
1012 {
1013         if (acpi_has_method(device->dev->handle, "_ADR"))
1014                 device->cap._ADR = 1;
1015         if (acpi_has_method(device->dev->handle, "_BCL"))
1016                 device->cap._BCL = 1;
1017         if (acpi_has_method(device->dev->handle, "_BCM"))
1018                 device->cap._BCM = 1;
1019         if (acpi_has_method(device->dev->handle, "_BQC")) {
1020                 device->cap._BQC = 1;
1021         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1022                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
1023                 device->cap._BCQ = 1;
1024         }
1025
1026         if (acpi_has_method(device->dev->handle, "_DDC"))
1027                 device->cap._DDC = 1;
1028 }
1029
1030 /*
1031  *  Arg:
1032  *      device  : video output device (VGA)
1033  *
1034  *  Return Value:
1035  *      None
1036  *
1037  *  Find out all required AML methods defined under the video bus device.
1038  */
1039
1040 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1041 {
1042         if (acpi_has_method(video->device->handle, "_DOS"))
1043                 video->cap._DOS = 1;
1044         if (acpi_has_method(video->device->handle, "_DOD"))
1045                 video->cap._DOD = 1;
1046         if (acpi_has_method(video->device->handle, "_ROM"))
1047                 video->cap._ROM = 1;
1048         if (acpi_has_method(video->device->handle, "_GPD"))
1049                 video->cap._GPD = 1;
1050         if (acpi_has_method(video->device->handle, "_SPD"))
1051                 video->cap._SPD = 1;
1052         if (acpi_has_method(video->device->handle, "_VPO"))
1053                 video->cap._VPO = 1;
1054 }
1055
1056 /*
1057  * Check whether the video bus device has required AML method to
1058  * support the desired features
1059  */
1060
1061 static int acpi_video_bus_check(struct acpi_video_bus *video)
1062 {
1063         acpi_status status = -ENOENT;
1064         struct pci_dev *dev;
1065
1066         if (!video)
1067                 return -EINVAL;
1068
1069         dev = acpi_get_pci_dev(video->device->handle);
1070         if (!dev)
1071                 return -ENODEV;
1072         pci_dev_put(dev);
1073
1074         /*
1075          * Since there is no HID, CID and so on for VGA driver, we have
1076          * to check well known required nodes.
1077          */
1078
1079         /* Does this device support video switching? */
1080         if (video->cap._DOS || video->cap._DOD) {
1081                 if (!video->cap._DOS) {
1082                         printk(KERN_WARNING FW_BUG
1083                                 "ACPI(%s) defines _DOD but not _DOS\n",
1084                                 acpi_device_bid(video->device));
1085                 }
1086                 video->flags.multihead = 1;
1087                 status = 0;
1088         }
1089
1090         /* Does this device support retrieving a video ROM? */
1091         if (video->cap._ROM) {
1092                 video->flags.rom = 1;
1093                 status = 0;
1094         }
1095
1096         /* Does this device support configuring which video device to POST? */
1097         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1098                 video->flags.post = 1;
1099                 status = 0;
1100         }
1101
1102         return status;
1103 }
1104
1105 /*
1106  * --------------------------------------------------------------------------
1107  *                               Driver Interface
1108  * --------------------------------------------------------------------------
1109  */
1110
1111 /* device interface */
1112 static struct acpi_video_device_attrib *
1113 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1114 {
1115         struct acpi_video_enumerated_device *ids;
1116         int i;
1117
1118         for (i = 0; i < video->attached_count; i++) {
1119                 ids = &video->attached_array[i];
1120                 if ((ids->value.int_val & 0xffff) == device_id)
1121                         return &ids->value.attrib;
1122         }
1123
1124         return NULL;
1125 }
1126
1127 static int
1128 acpi_video_get_device_type(struct acpi_video_bus *video,
1129                            unsigned long device_id)
1130 {
1131         struct acpi_video_enumerated_device *ids;
1132         int i;
1133
1134         for (i = 0; i < video->attached_count; i++) {
1135                 ids = &video->attached_array[i];
1136                 if ((ids->value.int_val & 0xffff) == device_id)
1137                         return ids->value.int_val;
1138         }
1139
1140         return 0;
1141 }
1142
1143 static int
1144 acpi_video_bus_get_one_device(struct acpi_device *device,
1145                               struct acpi_video_bus *video)
1146 {
1147         unsigned long long device_id;
1148         int status, device_type;
1149         struct acpi_video_device *data;
1150         struct acpi_video_device_attrib *attribute;
1151
1152         status =
1153             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1154         /* Some device omits _ADR, we skip them instead of fail */
1155         if (ACPI_FAILURE(status))
1156                 return 0;
1157
1158         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1159         if (!data)
1160                 return -ENOMEM;
1161
1162         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1163         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1164         device->driver_data = data;
1165
1166         data->device_id = device_id;
1167         data->video = video;
1168         data->dev = device;
1169         INIT_DELAYED_WORK(&data->switch_brightness_work,
1170                           acpi_video_switch_brightness);
1171
1172         attribute = acpi_video_get_device_attr(video, device_id);
1173
1174         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1175                 switch (attribute->display_type) {
1176                 case ACPI_VIDEO_DISPLAY_CRT:
1177                         data->flags.crt = 1;
1178                         break;
1179                 case ACPI_VIDEO_DISPLAY_TV:
1180                         data->flags.tvout = 1;
1181                         break;
1182                 case ACPI_VIDEO_DISPLAY_DVI:
1183                         data->flags.dvi = 1;
1184                         break;
1185                 case ACPI_VIDEO_DISPLAY_LCD:
1186                         data->flags.lcd = 1;
1187                         break;
1188                 default:
1189                         data->flags.unknown = 1;
1190                         break;
1191                 }
1192                 if (attribute->bios_can_detect)
1193                         data->flags.bios = 1;
1194         } else {
1195                 /* Check for legacy IDs */
1196                 device_type = acpi_video_get_device_type(video, device_id);
1197                 /* Ignore bits 16 and 18-20 */
1198                 switch (device_type & 0xffe2ffff) {
1199                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1200                         data->flags.crt = 1;
1201                         break;
1202                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1203                         data->flags.lcd = 1;
1204                         break;
1205                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1206                         data->flags.tvout = 1;
1207                         break;
1208                 default:
1209                         data->flags.unknown = 1;
1210                 }
1211         }
1212
1213         acpi_video_device_bind(video, data);
1214         acpi_video_device_find_cap(data);
1215
1216         mutex_lock(&video->device_list_lock);
1217         list_add_tail(&data->entry, &video->video_device_list);
1218         mutex_unlock(&video->device_list_lock);
1219
1220         return status;
1221 }
1222
1223 /*
1224  *  Arg:
1225  *      video   : video bus device
1226  *
1227  *  Return:
1228  *      none
1229  *
1230  *  Enumerate the video device list of the video bus,
1231  *  bind the ids with the corresponding video devices
1232  *  under the video bus.
1233  */
1234
1235 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1236 {
1237         struct acpi_video_device *dev;
1238
1239         mutex_lock(&video->device_list_lock);
1240
1241         list_for_each_entry(dev, &video->video_device_list, entry)
1242                 acpi_video_device_bind(video, dev);
1243
1244         mutex_unlock(&video->device_list_lock);
1245 }
1246
1247 /*
1248  *  Arg:
1249  *      video   : video bus device
1250  *      device  : video output device under the video
1251  *              bus
1252  *
1253  *  Return:
1254  *      none
1255  *
1256  *  Bind the ids with the corresponding video devices
1257  *  under the video bus.
1258  */
1259
1260 static void
1261 acpi_video_device_bind(struct acpi_video_bus *video,
1262                        struct acpi_video_device *device)
1263 {
1264         struct acpi_video_enumerated_device *ids;
1265         int i;
1266
1267         for (i = 0; i < video->attached_count; i++) {
1268                 ids = &video->attached_array[i];
1269                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1270                         ids->bind_info = device;
1271                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1272                 }
1273         }
1274 }
1275
1276 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1277 {
1278         struct acpi_video_bus *video = device->video;
1279         int i;
1280
1281         /*
1282          * If we have a broken _DOD or we have more than 8 output devices
1283          * under the graphics controller node that we can't proper deal with
1284          * in the operation region code currently, no need to test.
1285          */
1286         if (!video->attached_count || video->child_count > 8)
1287                 return true;
1288
1289         for (i = 0; i < video->attached_count; i++) {
1290                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1291                     (device->device_id & 0xfff))
1292                         return true;
1293         }
1294
1295         return false;
1296 }
1297
1298 /*
1299  *  Arg:
1300  *      video   : video bus device
1301  *
1302  *  Return:
1303  *      < 0     : error
1304  *
1305  *  Call _DOD to enumerate all devices attached to display adapter
1306  *
1307  */
1308
1309 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1310 {
1311         int status;
1312         int count;
1313         int i;
1314         struct acpi_video_enumerated_device *active_list;
1315         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1316         union acpi_object *dod = NULL;
1317         union acpi_object *obj;
1318
1319         if (!video->cap._DOD)
1320                 return AE_NOT_EXIST;
1321
1322         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1323         if (!ACPI_SUCCESS(status)) {
1324                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1325                 return status;
1326         }
1327
1328         dod = buffer.pointer;
1329         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1330                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1331                 status = -EFAULT;
1332                 goto out;
1333         }
1334
1335         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1336                           dod->package.count));
1337
1338         active_list = kcalloc(1 + dod->package.count,
1339                               sizeof(struct acpi_video_enumerated_device),
1340                               GFP_KERNEL);
1341         if (!active_list) {
1342                 status = -ENOMEM;
1343                 goto out;
1344         }
1345
1346         count = 0;
1347         for (i = 0; i < dod->package.count; i++) {
1348                 obj = &dod->package.elements[i];
1349
1350                 if (obj->type != ACPI_TYPE_INTEGER) {
1351                         printk(KERN_ERR PREFIX
1352                                 "Invalid _DOD data in element %d\n", i);
1353                         continue;
1354                 }
1355
1356                 active_list[count].value.int_val = obj->integer.value;
1357                 active_list[count].bind_info = NULL;
1358                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1359                                   (int)obj->integer.value));
1360                 count++;
1361         }
1362
1363         kfree(video->attached_array);
1364
1365         video->attached_array = active_list;
1366         video->attached_count = count;
1367
1368 out:
1369         kfree(buffer.pointer);
1370         return status;
1371 }
1372
1373 static int
1374 acpi_video_get_next_level(struct acpi_video_device *device,
1375                           u32 level_current, u32 event)
1376 {
1377         int min, max, min_above, max_below, i, l, delta = 255;
1378         max = max_below = 0;
1379         min = min_above = 255;
1380         /* Find closest level to level_current */
1381         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1382                 l = device->brightness->levels[i];
1383                 if (abs(l - level_current) < abs(delta)) {
1384                         delta = l - level_current;
1385                         if (!delta)
1386                                 break;
1387                 }
1388         }
1389         /* Ajust level_current to closest available level */
1390         level_current += delta;
1391         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1392                 l = device->brightness->levels[i];
1393                 if (l < min)
1394                         min = l;
1395                 if (l > max)
1396                         max = l;
1397                 if (l < min_above && l > level_current)
1398                         min_above = l;
1399                 if (l > max_below && l < level_current)
1400                         max_below = l;
1401         }
1402
1403         switch (event) {
1404         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1405                 return (level_current < max) ? min_above : min;
1406         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1407                 return (level_current < max) ? min_above : max;
1408         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1409                 return (level_current > min) ? max_below : min;
1410         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1411         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1412                 return 0;
1413         default:
1414                 return level_current;
1415         }
1416 }
1417
1418 static void
1419 acpi_video_switch_brightness(struct work_struct *work)
1420 {
1421         struct acpi_video_device *device = container_of(to_delayed_work(work),
1422                              struct acpi_video_device, switch_brightness_work);
1423         unsigned long long level_current, level_next;
1424         int event = device->switch_brightness_event;
1425         int result = -EINVAL;
1426
1427         /* no warning message if acpi_backlight=vendor or a quirk is used */
1428         if (!device->backlight)
1429                 return;
1430
1431         if (!device->brightness)
1432                 goto out;
1433
1434         result = acpi_video_device_lcd_get_level_current(device,
1435                                                          &level_current,
1436                                                          false);
1437         if (result)
1438                 goto out;
1439
1440         level_next = acpi_video_get_next_level(device, level_current, event);
1441
1442         result = acpi_video_device_lcd_set_level(device, level_next);
1443
1444         if (!result)
1445                 backlight_force_update(device->backlight,
1446                                        BACKLIGHT_UPDATE_HOTKEY);
1447
1448 out:
1449         if (result)
1450                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1451 }
1452
1453 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1454                         void **edid)
1455 {
1456         struct acpi_video_bus *video;
1457         struct acpi_video_device *video_device;
1458         union acpi_object *buffer = NULL;
1459         acpi_status status;
1460         int i, length;
1461
1462         if (!device || !acpi_driver_data(device))
1463                 return -EINVAL;
1464
1465         video = acpi_driver_data(device);
1466
1467         for (i = 0; i < video->attached_count; i++) {
1468                 video_device = video->attached_array[i].bind_info;
1469                 length = 256;
1470
1471                 if (!video_device)
1472                         continue;
1473
1474                 if (!video_device->cap._DDC)
1475                         continue;
1476
1477                 if (type) {
1478                         switch (type) {
1479                         case ACPI_VIDEO_DISPLAY_CRT:
1480                                 if (!video_device->flags.crt)
1481                                         continue;
1482                                 break;
1483                         case ACPI_VIDEO_DISPLAY_TV:
1484                                 if (!video_device->flags.tvout)
1485                                         continue;
1486                                 break;
1487                         case ACPI_VIDEO_DISPLAY_DVI:
1488                                 if (!video_device->flags.dvi)
1489                                         continue;
1490                                 break;
1491                         case ACPI_VIDEO_DISPLAY_LCD:
1492                                 if (!video_device->flags.lcd)
1493                                         continue;
1494                                 break;
1495                         }
1496                 } else if (video_device->device_id != device_id) {
1497                         continue;
1498                 }
1499
1500                 status = acpi_video_device_EDID(video_device, &buffer, length);
1501
1502                 if (ACPI_FAILURE(status) || !buffer ||
1503                     buffer->type != ACPI_TYPE_BUFFER) {
1504                         length = 128;
1505                         status = acpi_video_device_EDID(video_device, &buffer,
1506                                                         length);
1507                         if (ACPI_FAILURE(status) || !buffer ||
1508                             buffer->type != ACPI_TYPE_BUFFER) {
1509                                 continue;
1510                         }
1511                 }
1512
1513                 *edid = buffer->buffer.pointer;
1514                 return length;
1515         }
1516
1517         return -ENODEV;
1518 }
1519 EXPORT_SYMBOL(acpi_video_get_edid);
1520
1521 static int
1522 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1523                            struct acpi_device *device)
1524 {
1525         int status = 0;
1526         struct acpi_device *dev;
1527
1528         /*
1529          * There are systems where video module known to work fine regardless
1530          * of broken _DOD and ignoring returned value here doesn't cause
1531          * any issues later.
1532          */
1533         acpi_video_device_enumerate(video);
1534
1535         list_for_each_entry(dev, &device->children, node) {
1536
1537                 status = acpi_video_bus_get_one_device(dev, video);
1538                 if (status) {
1539                         dev_err(&dev->dev, "Can't attach device\n");
1540                         break;
1541                 }
1542                 video->child_count++;
1543         }
1544         return status;
1545 }
1546
1547 /* acpi_video interface */
1548
1549 /*
1550  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1551  * preform any automatic brightness change on receiving a notification.
1552  */
1553 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1554 {
1555         return acpi_video_bus_DOS(video, 0,
1556                                   acpi_osi_is_win8() ? 1 : 0);
1557 }
1558
1559 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1560 {
1561         return acpi_video_bus_DOS(video, 0,
1562                                   acpi_osi_is_win8() ? 0 : 1);
1563 }
1564
1565 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1566 {
1567         struct acpi_video_bus *video = acpi_driver_data(device);
1568         struct input_dev *input;
1569         int keycode = 0;
1570
1571         if (!video || !video->input)
1572                 return;
1573
1574         input = video->input;
1575
1576         switch (event) {
1577         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1578                                          * most likely via hotkey. */
1579                 keycode = KEY_SWITCHVIDEOMODE;
1580                 break;
1581
1582         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1583                                          * connector. */
1584                 acpi_video_device_enumerate(video);
1585                 acpi_video_device_rebind(video);
1586                 keycode = KEY_SWITCHVIDEOMODE;
1587                 break;
1588
1589         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1590                 keycode = KEY_SWITCHVIDEOMODE;
1591                 break;
1592         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1593                 keycode = KEY_VIDEO_NEXT;
1594                 break;
1595         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1596                 keycode = KEY_VIDEO_PREV;
1597                 break;
1598
1599         default:
1600                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1601                                   "Unsupported event [0x%x]\n", event));
1602                 break;
1603         }
1604
1605         if (acpi_notifier_call_chain(device, event, 0))
1606                 /* Something vetoed the keypress. */
1607                 keycode = 0;
1608
1609         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1610                 input_report_key(input, keycode, 1);
1611                 input_sync(input);
1612                 input_report_key(input, keycode, 0);
1613                 input_sync(input);
1614         }
1615
1616         return;
1617 }
1618
1619 static void brightness_switch_event(struct acpi_video_device *video_device,
1620                                     u32 event)
1621 {
1622         if (!brightness_switch_enabled)
1623                 return;
1624
1625         video_device->switch_brightness_event = event;
1626         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1627 }
1628
1629 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1630 {
1631         struct acpi_video_device *video_device = data;
1632         struct acpi_device *device = NULL;
1633         struct acpi_video_bus *bus;
1634         struct input_dev *input;
1635         int keycode = 0;
1636
1637         if (!video_device)
1638                 return;
1639
1640         device = video_device->dev;
1641         bus = video_device->video;
1642         input = bus->input;
1643
1644         if (hw_changes_brightness > 0) {
1645                 if (video_device->backlight)
1646                         backlight_force_update(video_device->backlight,
1647                                                BACKLIGHT_UPDATE_HOTKEY);
1648                 acpi_notifier_call_chain(device, event, 0);
1649                 return;
1650         }
1651
1652         switch (event) {
1653         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1654                 brightness_switch_event(video_device, event);
1655                 keycode = KEY_BRIGHTNESS_CYCLE;
1656                 break;
1657         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1658                 brightness_switch_event(video_device, event);
1659                 keycode = KEY_BRIGHTNESSUP;
1660                 break;
1661         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1662                 brightness_switch_event(video_device, event);
1663                 keycode = KEY_BRIGHTNESSDOWN;
1664                 break;
1665         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1666                 brightness_switch_event(video_device, event);
1667                 keycode = KEY_BRIGHTNESS_ZERO;
1668                 break;
1669         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1670                 brightness_switch_event(video_device, event);
1671                 keycode = KEY_DISPLAY_OFF;
1672                 break;
1673         default:
1674                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1675                                   "Unsupported event [0x%x]\n", event));
1676                 break;
1677         }
1678
1679         acpi_notifier_call_chain(device, event, 0);
1680
1681         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1682                 input_report_key(input, keycode, 1);
1683                 input_sync(input);
1684                 input_report_key(input, keycode, 0);
1685                 input_sync(input);
1686         }
1687
1688         return;
1689 }
1690
1691 static int acpi_video_resume(struct notifier_block *nb,
1692                                 unsigned long val, void *ign)
1693 {
1694         struct acpi_video_bus *video;
1695         struct acpi_video_device *video_device;
1696         int i;
1697
1698         switch (val) {
1699         case PM_HIBERNATION_PREPARE:
1700         case PM_SUSPEND_PREPARE:
1701         case PM_RESTORE_PREPARE:
1702                 return NOTIFY_DONE;
1703         }
1704
1705         video = container_of(nb, struct acpi_video_bus, pm_nb);
1706
1707         dev_info(&video->device->dev, "Restoring backlight state\n");
1708
1709         for (i = 0; i < video->attached_count; i++) {
1710                 video_device = video->attached_array[i].bind_info;
1711                 if (video_device && video_device->brightness)
1712                         acpi_video_device_lcd_set_level(video_device,
1713                                         video_device->brightness->curr);
1714         }
1715
1716         return NOTIFY_OK;
1717 }
1718
1719 static acpi_status
1720 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1721                         void **return_value)
1722 {
1723         struct acpi_device *device = context;
1724         struct acpi_device *sibling;
1725         int result;
1726
1727         if (handle == device->handle)
1728                 return AE_CTRL_TERMINATE;
1729
1730         result = acpi_bus_get_device(handle, &sibling);
1731         if (result)
1732                 return AE_OK;
1733
1734         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1735                         return AE_ALREADY_EXISTS;
1736
1737         return AE_OK;
1738 }
1739
1740 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1741 {
1742         struct backlight_properties props;
1743         struct pci_dev *pdev;
1744         acpi_handle acpi_parent;
1745         struct device *parent = NULL;
1746         int result;
1747         static int count;
1748         char *name;
1749
1750         result = acpi_video_init_brightness(device);
1751         if (result)
1752                 return;
1753
1754         if (disable_backlight_sysfs_if > 0)
1755                 return;
1756
1757         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1758         if (!name)
1759                 return;
1760         count++;
1761
1762         acpi_get_parent(device->dev->handle, &acpi_parent);
1763
1764         pdev = acpi_get_pci_dev(acpi_parent);
1765         if (pdev) {
1766                 parent = &pdev->dev;
1767                 pci_dev_put(pdev);
1768         }
1769
1770         memset(&props, 0, sizeof(struct backlight_properties));
1771         props.type = BACKLIGHT_FIRMWARE;
1772         props.max_brightness =
1773                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1774         device->backlight = backlight_device_register(name,
1775                                                       parent,
1776                                                       device,
1777                                                       &acpi_backlight_ops,
1778                                                       &props);
1779         kfree(name);
1780         if (IS_ERR(device->backlight)) {
1781                 device->backlight = NULL;
1782                 return;
1783         }
1784
1785         /*
1786          * Save current brightness level in case we have to restore it
1787          * before acpi_video_device_lcd_set_level() is called next time.
1788          */
1789         device->backlight->props.brightness =
1790                         acpi_video_get_brightness(device->backlight);
1791
1792         device->cooling_dev = thermal_cooling_device_register("LCD",
1793                                 device->dev, &video_cooling_ops);
1794         if (IS_ERR(device->cooling_dev)) {
1795                 /*
1796                  * Set cooling_dev to NULL so we don't crash trying to free it.
1797                  * Also, why the hell we are returning early and not attempt to
1798                  * register video output if cooling device registration failed?
1799                  * -- dtor
1800                  */
1801                 device->cooling_dev = NULL;
1802                 return;
1803         }
1804
1805         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1806                  device->cooling_dev->id);
1807         result = sysfs_create_link(&device->dev->dev.kobj,
1808                         &device->cooling_dev->device.kobj,
1809                         "thermal_cooling");
1810         if (result)
1811                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1812         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1813                         &device->dev->dev.kobj, "device");
1814         if (result)
1815                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1816 }
1817
1818 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1819 {
1820         struct acpi_video_device *dev;
1821         union acpi_object *levels;
1822
1823         mutex_lock(&video->device_list_lock);
1824         list_for_each_entry(dev, &video->video_device_list, entry) {
1825                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1826                         kfree(levels);
1827         }
1828         mutex_unlock(&video->device_list_lock);
1829 }
1830
1831 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1832 {
1833         /*
1834          * Do not create backlight device for video output
1835          * device that is not in the enumerated list.
1836          */
1837         if (!acpi_video_device_in_dod(dev)) {
1838                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1839                 return false;
1840         }
1841
1842         if (only_lcd)
1843                 return dev->flags.lcd;
1844         return true;
1845 }
1846
1847 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1848 {
1849         struct acpi_video_device *dev;
1850
1851         if (video->backlight_registered)
1852                 return 0;
1853
1854         acpi_video_run_bcl_for_osi(video);
1855
1856         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1857                 return 0;
1858
1859         mutex_lock(&video->device_list_lock);
1860         list_for_each_entry(dev, &video->video_device_list, entry) {
1861                 if (acpi_video_should_register_backlight(dev))
1862                         acpi_video_dev_register_backlight(dev);
1863         }
1864         mutex_unlock(&video->device_list_lock);
1865
1866         video->backlight_registered = true;
1867
1868         video->pm_nb.notifier_call = acpi_video_resume;
1869         video->pm_nb.priority = 0;
1870         return register_pm_notifier(&video->pm_nb);
1871 }
1872
1873 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1874 {
1875         if (device->backlight) {
1876                 backlight_device_unregister(device->backlight);
1877                 device->backlight = NULL;
1878         }
1879         if (device->brightness) {
1880                 kfree(device->brightness->levels);
1881                 kfree(device->brightness);
1882                 device->brightness = NULL;
1883         }
1884         if (device->cooling_dev) {
1885                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1886                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1887                 thermal_cooling_device_unregister(device->cooling_dev);
1888                 device->cooling_dev = NULL;
1889         }
1890 }
1891
1892 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1893 {
1894         struct acpi_video_device *dev;
1895         int error;
1896
1897         if (!video->backlight_registered)
1898                 return 0;
1899
1900         error = unregister_pm_notifier(&video->pm_nb);
1901
1902         mutex_lock(&video->device_list_lock);
1903         list_for_each_entry(dev, &video->video_device_list, entry)
1904                 acpi_video_dev_unregister_backlight(dev);
1905         mutex_unlock(&video->device_list_lock);
1906
1907         video->backlight_registered = false;
1908
1909         return error;
1910 }
1911
1912 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1913 {
1914         acpi_status status;
1915         struct acpi_device *adev = device->dev;
1916
1917         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1918                                              acpi_video_device_notify, device);
1919         if (ACPI_FAILURE(status))
1920                 dev_err(&adev->dev, "Error installing notify handler\n");
1921         else
1922                 device->flags.notify = 1;
1923 }
1924
1925 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1926 {
1927         struct input_dev *input;
1928         struct acpi_video_device *dev;
1929         int error;
1930
1931         video->input = input = input_allocate_device();
1932         if (!input) {
1933                 error = -ENOMEM;
1934                 goto out;
1935         }
1936
1937         error = acpi_video_bus_start_devices(video);
1938         if (error)
1939                 goto err_free_input;
1940
1941         snprintf(video->phys, sizeof(video->phys),
1942                         "%s/video/input0", acpi_device_hid(video->device));
1943
1944         input->name = acpi_device_name(video->device);
1945         input->phys = video->phys;
1946         input->id.bustype = BUS_HOST;
1947         input->id.product = 0x06;
1948         input->dev.parent = &video->device->dev;
1949         input->evbit[0] = BIT(EV_KEY);
1950         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1951         set_bit(KEY_VIDEO_NEXT, input->keybit);
1952         set_bit(KEY_VIDEO_PREV, input->keybit);
1953         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1954         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1955         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1956         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1957         set_bit(KEY_DISPLAY_OFF, input->keybit);
1958
1959         error = input_register_device(input);
1960         if (error)
1961                 goto err_stop_dev;
1962
1963         mutex_lock(&video->device_list_lock);
1964         list_for_each_entry(dev, &video->video_device_list, entry)
1965                 acpi_video_dev_add_notify_handler(dev);
1966         mutex_unlock(&video->device_list_lock);
1967
1968         return 0;
1969
1970 err_stop_dev:
1971         acpi_video_bus_stop_devices(video);
1972 err_free_input:
1973         input_free_device(input);
1974         video->input = NULL;
1975 out:
1976         return error;
1977 }
1978
1979 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1980 {
1981         if (dev->flags.notify) {
1982                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1983                                            acpi_video_device_notify);
1984                 dev->flags.notify = 0;
1985         }
1986 }
1987
1988 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1989 {
1990         struct acpi_video_device *dev;
1991
1992         mutex_lock(&video->device_list_lock);
1993         list_for_each_entry(dev, &video->video_device_list, entry)
1994                 acpi_video_dev_remove_notify_handler(dev);
1995         mutex_unlock(&video->device_list_lock);
1996
1997         acpi_video_bus_stop_devices(video);
1998         input_unregister_device(video->input);
1999         video->input = NULL;
2000 }
2001
2002 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
2003 {
2004         struct acpi_video_device *dev, *next;
2005
2006         mutex_lock(&video->device_list_lock);
2007         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
2008                 list_del(&dev->entry);
2009                 kfree(dev);
2010         }
2011         mutex_unlock(&video->device_list_lock);
2012
2013         return 0;
2014 }
2015
2016 static int instance;
2017
2018 static int acpi_video_bus_add(struct acpi_device *device)
2019 {
2020         struct acpi_video_bus *video;
2021         int error;
2022         acpi_status status;
2023
2024         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2025                                 device->parent->handle, 1,
2026                                 acpi_video_bus_match, NULL,
2027                                 device, NULL);
2028         if (status == AE_ALREADY_EXISTS) {
2029                 printk(KERN_WARNING FW_BUG
2030                         "Duplicate ACPI video bus devices for the"
2031                         " same VGA controller, please try module "
2032                         "parameter \"video.allow_duplicates=1\""
2033                         "if the current driver doesn't work.\n");
2034                 if (!allow_duplicates)
2035                         return -ENODEV;
2036         }
2037
2038         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2039         if (!video)
2040                 return -ENOMEM;
2041
2042         /* a hack to fix the duplicate name "VID" problem on T61 */
2043         if (!strcmp(device->pnp.bus_id, "VID")) {
2044                 if (instance)
2045                         device->pnp.bus_id[3] = '0' + instance;
2046                 instance++;
2047         }
2048         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2049         if (!strcmp(device->pnp.bus_id, "VGA")) {
2050                 if (instance)
2051                         device->pnp.bus_id[3] = '0' + instance;
2052                 instance++;
2053         }
2054
2055         video->device = device;
2056         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2057         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2058         device->driver_data = video;
2059
2060         acpi_video_bus_find_cap(video);
2061         error = acpi_video_bus_check(video);
2062         if (error)
2063                 goto err_free_video;
2064
2065         mutex_init(&video->device_list_lock);
2066         INIT_LIST_HEAD(&video->video_device_list);
2067
2068         error = acpi_video_bus_get_devices(video, device);
2069         if (error)
2070                 goto err_put_video;
2071
2072         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2073                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2074                video->flags.multihead ? "yes" : "no",
2075                video->flags.rom ? "yes" : "no",
2076                video->flags.post ? "yes" : "no");
2077         mutex_lock(&video_list_lock);
2078         list_add_tail(&video->entry, &video_bus_head);
2079         mutex_unlock(&video_list_lock);
2080
2081         acpi_video_bus_register_backlight(video);
2082         acpi_video_bus_add_notify_handler(video);
2083
2084         return 0;
2085
2086 err_put_video:
2087         acpi_video_bus_put_devices(video);
2088         kfree(video->attached_array);
2089 err_free_video:
2090         kfree(video);
2091         device->driver_data = NULL;
2092
2093         return error;
2094 }
2095
2096 static int acpi_video_bus_remove(struct acpi_device *device)
2097 {
2098         struct acpi_video_bus *video = NULL;
2099
2100
2101         if (!device || !acpi_driver_data(device))
2102                 return -EINVAL;
2103
2104         video = acpi_driver_data(device);
2105
2106         acpi_video_bus_remove_notify_handler(video);
2107         acpi_video_bus_unregister_backlight(video);
2108         acpi_video_bus_put_devices(video);
2109
2110         mutex_lock(&video_list_lock);
2111         list_del(&video->entry);
2112         mutex_unlock(&video_list_lock);
2113
2114         kfree(video->attached_array);
2115         kfree(video);
2116
2117         return 0;
2118 }
2119
2120 static int __init is_i740(struct pci_dev *dev)
2121 {
2122         if (dev->device == 0x00D1)
2123                 return 1;
2124         if (dev->device == 0x7000)
2125                 return 1;
2126         return 0;
2127 }
2128
2129 static int __init intel_opregion_present(void)
2130 {
2131         int opregion = 0;
2132         struct pci_dev *dev = NULL;
2133         u32 address;
2134
2135         for_each_pci_dev(dev) {
2136                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2137                         continue;
2138                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2139                         continue;
2140                 /* We don't want to poke around undefined i740 registers */
2141                 if (is_i740(dev))
2142                         continue;
2143                 pci_read_config_dword(dev, 0xfc, &address);
2144                 if (!address)
2145                         continue;
2146                 opregion = 1;
2147         }
2148         return opregion;
2149 }
2150
2151 /* Check if the chassis-type indicates there is no builtin LCD panel */
2152 static bool dmi_is_desktop(void)
2153 {
2154         const char *chassis_type;
2155         unsigned long type;
2156
2157         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2158         if (!chassis_type)
2159                 return false;
2160
2161         if (kstrtoul(chassis_type, 10, &type) != 0)
2162                 return false;
2163
2164         switch (type) {
2165         case 0x03: /* Desktop */
2166         case 0x04: /* Low Profile Desktop */
2167         case 0x05: /* Pizza Box */
2168         case 0x06: /* Mini Tower */
2169         case 0x07: /* Tower */
2170         case 0x10: /* Lunch Box */
2171         case 0x11: /* Main Server Chassis */
2172                 return true;
2173         }
2174
2175         return false;
2176 }
2177
2178 int acpi_video_register(void)
2179 {
2180         int ret = 0;
2181
2182         mutex_lock(&register_count_mutex);
2183         if (register_count) {
2184                 /*
2185                  * if the function of acpi_video_register is already called,
2186                  * don't register the acpi_vide_bus again and return no error.
2187                  */
2188                 goto leave;
2189         }
2190
2191         /*
2192          * We're seeing a lot of bogus backlight interfaces on newer machines
2193          * without a LCD such as desktops, servers and HDMI sticks. Checking
2194          * the lcd flag fixes this, so enable this on any machines which are
2195          * win8 ready (where we also prefer the native backlight driver, so
2196          * normally the acpi_video code should not register there anyways).
2197          */
2198         if (only_lcd == -1) {
2199                 if (dmi_is_desktop() && acpi_osi_is_win8())
2200                         only_lcd = true;
2201                 else
2202                         only_lcd = false;
2203         }
2204
2205         dmi_check_system(video_dmi_table);
2206
2207         ret = acpi_bus_register_driver(&acpi_video_bus);
2208         if (ret)
2209                 goto leave;
2210
2211         /*
2212          * When the acpi_video_bus is loaded successfully, increase
2213          * the counter reference.
2214          */
2215         register_count = 1;
2216
2217 leave:
2218         mutex_unlock(&register_count_mutex);
2219         return ret;
2220 }
2221 EXPORT_SYMBOL(acpi_video_register);
2222
2223 void acpi_video_unregister(void)
2224 {
2225         mutex_lock(&register_count_mutex);
2226         if (register_count) {
2227                 acpi_bus_unregister_driver(&acpi_video_bus);
2228                 register_count = 0;
2229         }
2230         mutex_unlock(&register_count_mutex);
2231 }
2232 EXPORT_SYMBOL(acpi_video_unregister);
2233
2234 void acpi_video_unregister_backlight(void)
2235 {
2236         struct acpi_video_bus *video;
2237
2238         mutex_lock(&register_count_mutex);
2239         if (register_count) {
2240                 mutex_lock(&video_list_lock);
2241                 list_for_each_entry(video, &video_bus_head, entry)
2242                         acpi_video_bus_unregister_backlight(video);
2243                 mutex_unlock(&video_list_lock);
2244         }
2245         mutex_unlock(&register_count_mutex);
2246 }
2247
2248 bool acpi_video_handles_brightness_key_presses(void)
2249 {
2250         bool have_video_busses;
2251
2252         mutex_lock(&video_list_lock);
2253         have_video_busses = !list_empty(&video_bus_head);
2254         mutex_unlock(&video_list_lock);
2255
2256         return have_video_busses &&
2257                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2258 }
2259 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2260
2261 /*
2262  * This is kind of nasty. Hardware using Intel chipsets may require
2263  * the video opregion code to be run first in order to initialise
2264  * state before any ACPI video calls are made. To handle this we defer
2265  * registration of the video class until the opregion code has run.
2266  */
2267
2268 static int __init acpi_video_init(void)
2269 {
2270         /*
2271          * Let the module load even if ACPI is disabled (e.g. due to
2272          * a broken BIOS) so that i915.ko can still be loaded on such
2273          * old systems without an AcpiOpRegion.
2274          *
2275          * acpi_video_register() will report -ENODEV later as well due
2276          * to acpi_disabled when i915.ko tries to register itself afterwards.
2277          */
2278         if (acpi_disabled)
2279                 return 0;
2280
2281         if (intel_opregion_present())
2282                 return 0;
2283
2284         return acpi_video_register();
2285 }
2286
2287 static void __exit acpi_video_exit(void)
2288 {
2289         acpi_video_detect_exit();
2290         acpi_video_unregister();
2291
2292         return;
2293 }
2294
2295 module_init(acpi_video_init);
2296 module_exit(acpi_video_exit);