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 <luming.yu@intel.com>
   6  *  Copyright (C) 2004 Bruno Ducrot <ducrot@poupinou.org>
   7  *  Copyright (C) 2006 Thomas Tuttle <linux-kernel@ttuttle.net>
   8  */
   9
  10 #define pr_fmt(fmt) "ACPI: video: " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/module.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/list.h>
  17 #include <linux/mutex.h>
  18 #include <linux/input.h>
  19 #include <linux/backlight.h>
  20 #include <linux/thermal.h>
  21 #include <linux/sort.h>
  22 #include <linux/pci.h>
  23 #include <linux/pci_ids.h>
  24 #include <linux/slab.h>
  25 #include <linux/dmi.h>
  26 #include <linux/suspend.h>
  27 #include <linux/acpi.h>
  28 #include <acpi/video.h>
  29 #include <linux/uaccess.h>
  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 MODULE_AUTHOR("Bruno Ducrot");
  37 MODULE_DESCRIPTION("ACPI Video Driver");
  38 MODULE_LICENSE("GPL");
  39
  40 static bool brightness_switch_enabled = true;
  41 module_param(brightness_switch_enabled, bool, 0644);
  42
  43 /*
  44  * By default, we don't allow duplicate ACPI video bus devices
  45  * under the same VGA controller
  46  */
  47 static bool allow_duplicates;
  48 module_param(allow_duplicates, bool, 0644);
  49
  50 static int disable_backlight_sysfs_if = -1;
  51 module_param(disable_backlight_sysfs_if, int, 0444);
  52
  53 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  54 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  55 static int report_key_events = -1;
  56 module_param(report_key_events, int, 0644);
  57 MODULE_PARM_DESC(report_key_events,
  58         "0: none, 1: output changes, 2: brightness changes, 3: all");
  59
  60 static int hw_changes_brightness = -1;
  61 module_param(hw_changes_brightness, int, 0644);
  62 MODULE_PARM_DESC(hw_changes_brightness,
  63         "Set this to 1 on buggy hw which changes the brightness itself when "
  64         "a hotkey is pressed: -1: auto, 0: normal 1: hw-changes-brightness");
  65
  66 /*
  67  * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
  68  * assumed even if not actually set.
  69  */
  70 static bool device_id_scheme = false;
  71 module_param(device_id_scheme, bool, 0444);
  72
  73 static int only_lcd = -1;
  74 module_param(only_lcd, int, 0444);
  75
  76 static int register_count;
  77 static DEFINE_MUTEX(register_count_mutex);
  78 static DEFINE_MUTEX(video_list_lock);
  79 static LIST_HEAD(video_bus_head);
  80 static int acpi_video_bus_add(struct acpi_device *device);
  81 static int acpi_video_bus_remove(struct acpi_device *device);
  82 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  83 void acpi_video_detect_exit(void);
  84
  85 /*
  86  * Indices in the _BCL method response: the first two items are special,
  87  * the rest are all supported levels.
  88  *
  89  * See page 575 of the ACPI spec 3.0
  90  */
  91 enum acpi_video_level_idx {
  92         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
  93         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
  94         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
  95 };
  96
  97 static const struct acpi_device_id video_device_ids[] = {
  98         {ACPI_VIDEO_HID, 0},
  99         {"", 0},
 100 };
 101 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 102
 103 static struct acpi_driver acpi_video_bus = {
 104         .name = "video",
 105         .class = ACPI_VIDEO_CLASS,
 106         .ids = video_device_ids,
 107         .ops = {
 108                 .add = acpi_video_bus_add,
 109                 .remove = acpi_video_bus_remove,
 110                 .notify = acpi_video_bus_notify,
 111                 },
 112 };
 113
 114 struct acpi_video_bus_flags {
 115         u8 multihead:1;         /* can switch video heads */
 116         u8 rom:1;               /* can retrieve a video rom */
 117         u8 post:1;              /* can configure the head to */
 118         u8 reserved:5;
 119 };
 120
 121 struct acpi_video_bus_cap {
 122         u8 _DOS:1;              /* Enable/Disable output switching */
 123         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 124         u8 _ROM:1;              /* Get ROM Data */
 125         u8 _GPD:1;              /* Get POST Device */
 126         u8 _SPD:1;              /* Set POST Device */
 127         u8 _VPO:1;              /* Video POST Options */
 128         u8 reserved:2;
 129 };
 130
 131 struct acpi_video_device_attrib {
 132         u32 display_index:4;    /* A zero-based instance of the Display */
 133         u32 display_port_attachment:4;  /* This field differentiates the display type */
 134         u32 display_type:4;     /* Describe the specific type in use */
 135         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 136         u32 bios_can_detect:1;  /* BIOS can detect the device */
 137         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 138                                    the VGA device. */
 139         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 140         u32 reserved:10;        /* Must be 0 */
 141
 142         /*
 143          * The device ID might not actually follow the scheme described by this
 144          * struct acpi_video_device_attrib. If it does, then this bit
 145          * device_id_scheme is set; otherwise, other fields should be ignored.
 146          *
 147          * (but also see the global flag device_id_scheme)
 148          */
 149         u32 device_id_scheme:1;
 150 };
 151
 152 struct acpi_video_enumerated_device {
 153         union {
 154                 u32 int_val;
 155                 struct acpi_video_device_attrib attrib;
 156         } value;
 157         struct acpi_video_device *bind_info;
 158 };
 159
 160 struct acpi_video_bus {
 161         struct acpi_device *device;
 162         bool backlight_registered;
 163         u8 dos_setting;
 164         struct acpi_video_enumerated_device *attached_array;
 165         u8 attached_count;
 166         u8 child_count;
 167         struct acpi_video_bus_cap cap;
 168         struct acpi_video_bus_flags flags;
 169         struct list_head video_device_list;
 170         struct mutex device_list_lock;  /* protects video_device_list */
 171         struct list_head entry;
 172         struct input_dev *input;
 173         char phys[32];  /* for input device */
 174         struct notifier_block pm_nb;
 175 };
 176
 177 struct acpi_video_device_flags {
 178         u8 crt:1;
 179         u8 lcd:1;
 180         u8 tvout:1;
 181         u8 dvi:1;
 182         u8 bios:1;
 183         u8 unknown:1;
 184         u8 notify:1;
 185         u8 reserved:1;
 186 };
 187
 188 struct acpi_video_device_cap {
 189         u8 _ADR:1;              /* Return the unique ID */
 190         u8 _BCL:1;              /* Query list of brightness control levels supported */
 191         u8 _BCM:1;              /* Set the brightness level */
 192         u8 _BQC:1;              /* Get current brightness level */
 193         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 194         u8 _DDC:1;              /* Return the EDID for this device */
 195 };
 196
 197 struct acpi_video_device {
 198         unsigned long device_id;
 199         struct acpi_video_device_flags flags;
 200         struct acpi_video_device_cap cap;
 201         struct list_head entry;
 202         struct delayed_work switch_brightness_work;
 203         int switch_brightness_event;
 204         struct acpi_video_bus *video;
 205         struct acpi_device *dev;
 206         struct acpi_video_device_brightness *brightness;
 207         struct backlight_device *backlight;
 208         struct thermal_cooling_device *cooling_dev;
 209 };
 210
 211 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 212 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 213 static void acpi_video_device_bind(struct acpi_video_bus *video,
 214                                    struct acpi_video_device *device);
 215 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 216 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 217                         int level);
 218 static int acpi_video_device_lcd_get_level_current(
 219                         struct acpi_video_device *device,
 220                         unsigned long long *level, bool raw);
 221 static int acpi_video_get_next_level(struct acpi_video_device *device,
 222                                      u32 level_current, u32 event);
 223 static void acpi_video_switch_brightness(struct work_struct *work);
 224
 225 /* backlight device sysfs support */
 226 static int acpi_video_get_brightness(struct backlight_device *bd)
 227 {
 228         unsigned long long cur_level;
 229         int i;
 230         struct acpi_video_device *vd = bl_get_data(bd);
 231
 232         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 233                 return -EINVAL;
 234         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 235                 if (vd->brightness->levels[i] == cur_level)
 236                         return i - ACPI_VIDEO_FIRST_LEVEL;
 237         }
 238         return 0;
 239 }
 240
 241 static int acpi_video_set_brightness(struct backlight_device *bd)
 242 {
 243         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 244         struct acpi_video_device *vd = bl_get_data(bd);
 245
 246         cancel_delayed_work(&vd->switch_brightness_work);
 247         return acpi_video_device_lcd_set_level(vd,
 248                                 vd->brightness->levels[request_level]);
 249 }
 250
 251 static const struct backlight_ops acpi_backlight_ops = {
 252         .get_brightness = acpi_video_get_brightness,
 253         .update_status  = acpi_video_set_brightness,
 254 };
 255
 256 /* thermal cooling device callbacks */
 257 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 258                                unsigned long *state)
 259 {
 260         struct acpi_device *device = cooling_dev->devdata;
 261         struct acpi_video_device *video = acpi_driver_data(device);
 262
 263         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 264         return 0;
 265 }
 266
 267 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 268                                unsigned long *state)
 269 {
 270         struct acpi_device *device = cooling_dev->devdata;
 271         struct acpi_video_device *video = acpi_driver_data(device);
 272         unsigned long long level;
 273         int offset;
 274
 275         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 276                 return -EINVAL;
 277         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 278              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 - ACPI_VIDEO_FIRST_LEVEL)
 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_FAILURE(status))
 327                 return status;
 328         obj = (union acpi_object *)buffer.pointer;
 329         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 330                 acpi_handle_info(handle, "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_handle_info(device->dev->handle, "_BCM evaluation failed\n");
 355                 return -EIO;
 356         }
 357
 358         device->brightness->curr = level;
 359         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 360              state++)
 361                 if (level == device->brightness->levels[state]) {
 362                         if (device->backlight)
 363                                 device->backlight->props.brightness =
 364                                         state - ACPI_VIDEO_FIRST_LEVEL;
 365                         return 0;
 366                 }
 367
 368         acpi_handle_info(device->dev->handle, "Current brightness invalid\n");
 369         return -EINVAL;
 370 }
 371
 372 /*
 373  * For some buggy _BQC methods, we need to add a constant value to
 374  * the _BQC return value to get the actual current brightness level
 375  */
 376
 377 static int bqc_offset_aml_bug_workaround;
 378 static int video_set_bqc_offset(const struct dmi_system_id *d)
 379 {
 380         bqc_offset_aml_bug_workaround = 9;
 381         return 0;
 382 }
 383
 384 static int video_disable_backlight_sysfs_if(
 385         const struct dmi_system_id *d)
 386 {
 387         if (disable_backlight_sysfs_if == -1)
 388                 disable_backlight_sysfs_if = 1;
 389         return 0;
 390 }
 391
 392 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 393 {
 394         device_id_scheme = true;
 395         return 0;
 396 }
 397
 398 static int video_enable_only_lcd(const struct dmi_system_id *d)
 399 {
 400         only_lcd = true;
 401         return 0;
 402 }
 403
 404 static int video_set_report_key_events(const struct dmi_system_id *id)
 405 {
 406         if (report_key_events == -1)
 407                 report_key_events = (uintptr_t)id->driver_data;
 408         return 0;
 409 }
 410
 411 static int video_hw_changes_brightness(
 412         const struct dmi_system_id *d)
 413 {
 414         if (hw_changes_brightness == -1)
 415                 hw_changes_brightness = 1;
 416         return 0;
 417 }
 418
 419 static const struct dmi_system_id video_dmi_table[] = {
 420         /*
 421          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 422          */
 423         {
 424          .callback = video_set_bqc_offset,
 425          .ident = "Acer Aspire 5720",
 426          .matches = {
 427                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 428                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 429                 },
 430         },
 431         {
 432          .callback = video_set_bqc_offset,
 433          .ident = "Acer Aspire 5710Z",
 434          .matches = {
 435                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 436                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 437                 },
 438         },
 439         {
 440          .callback = video_set_bqc_offset,
 441          .ident = "eMachines E510",
 442          .matches = {
 443                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 444                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 445                 },
 446         },
 447         {
 448          .callback = video_set_bqc_offset,
 449          .ident = "Acer Aspire 5315",
 450          .matches = {
 451                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 452                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 453                 },
 454         },
 455         {
 456          .callback = video_set_bqc_offset,
 457          .ident = "Acer Aspire 7720",
 458          .matches = {
 459                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 460                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 461                 },
 462         },
 463
 464         /*
 465          * Some machines have a broken acpi-video interface for brightness
 466          * control, but still need an acpi_video_device_lcd_set_level() call
 467          * on resume to turn the backlight power on.  We Enable backlight
 468          * control on these systems, but do not register a backlight sysfs
 469          * as brightness control does not work.
 470          */
 471         {
 472          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 473          .callback = video_disable_backlight_sysfs_if,
 474          .ident = "Toshiba Portege R700",
 475          .matches = {
 476                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 477                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 478                 },
 479         },
 480         {
 481          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 482          .callback = video_disable_backlight_sysfs_if,
 483          .ident = "Toshiba Portege R830",
 484          .matches = {
 485                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 486                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 487                 },
 488         },
 489         {
 490          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 491          .callback = video_disable_backlight_sysfs_if,
 492          .ident = "Toshiba Satellite R830",
 493          .matches = {
 494                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 495                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 496                 },
 497         },
 498         /*
 499          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 500          * but the IDs actually follow the Device ID Scheme.
 501          */
 502         {
 503          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 504          .callback = video_set_device_id_scheme,
 505          .ident = "ESPRIMO Mobile M9410",
 506          .matches = {
 507                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 508                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 509                 },
 510         },
 511         /*
 512          * Some machines have multiple video output devices, but only the one
 513          * that is the type of LCD can do the backlight control so we should not
 514          * register backlight interface for other video output devices.
 515          */
 516         {
 517          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 518          .callback = video_enable_only_lcd,
 519          .ident = "ESPRIMO Mobile M9410",
 520          .matches = {
 521                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 522                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 523                 },
 524         },
 525         /*
 526          * Some machines report wrong key events on the acpi-bus, suppress
 527          * key event reporting on these.  Note this is only intended to work
 528          * around events which are plain wrong. In some cases we get double
 529          * events, in this case acpi-video is considered the canonical source
 530          * and the events from the other source should be filtered. E.g.
 531          * by calling acpi_video_handles_brightness_key_presses() from the
 532          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 533          */
 534         {
 535          .callback = video_set_report_key_events,
 536          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 537          .ident = "Dell Vostro V131",
 538          .matches = {
 539                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 540                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 541                 },
 542         },
 543         /*
 544          * Some machines change the brightness themselves when a brightness
 545          * hotkey gets pressed, despite us telling them not to. In this case
 546          * acpi_video_device_notify() should only call backlight_force_update(
 547          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 548          */
 549         {
 550          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 551          .callback = video_hw_changes_brightness,
 552          .ident = "Packard Bell EasyNote MZ35",
 553          .matches = {
 554                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 555                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 556                 },
 557         },
 558         {}
 559 };
 560
 561 static unsigned long long
 562 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 563                               unsigned long long bqc_value)
 564 {
 565         unsigned long long level;
 566
 567         if (device->brightness->flags._BQC_use_index) {
 568                 /*
 569                  * _BQC returns an index that doesn't account for the first 2
 570                  * items with special meaning (see enum acpi_video_level_idx),
 571                  * so we need to compensate for that by offsetting ourselves
 572                  */
 573                 if (device->brightness->flags._BCL_reversed)
 574                         bqc_value = device->brightness->count -
 575                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 576
 577                 level = device->brightness->levels[bqc_value +
 578                                                    ACPI_VIDEO_FIRST_LEVEL];
 579         } else {
 580                 level = bqc_value;
 581         }
 582
 583         level += bqc_offset_aml_bug_workaround;
 584
 585         return level;
 586 }
 587
 588 static int
 589 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 590                                         unsigned long long *level, bool raw)
 591 {
 592         acpi_status status = AE_OK;
 593         int i;
 594
 595         if (device->cap._BQC || device->cap._BCQ) {
 596                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 597
 598                 status = acpi_evaluate_integer(device->dev->handle, buf,
 599                                                 NULL, level);
 600                 if (ACPI_SUCCESS(status)) {
 601                         if (raw) {
 602                                 /*
 603                                  * Caller has indicated he wants the raw
 604                                  * value returned by _BQC, so don't furtherly
 605                                  * mess with the value.
 606                                  */
 607                                 return 0;
 608                         }
 609
 610                         *level = acpi_video_bqc_value_to_level(device, *level);
 611
 612                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 613                              i < device->brightness->count; i++)
 614                                 if (device->brightness->levels[i] == *level) {
 615                                         device->brightness->curr = *level;
 616                                         return 0;
 617                                 }
 618                         /*
 619                          * BQC returned an invalid level.
 620                          * Stop using it.
 621                          */
 622                         acpi_handle_info(device->dev->handle,
 623                                          "%s returned an invalid level", buf);
 624                         device->cap._BQC = device->cap._BCQ = 0;
 625                 } else {
 626                         /*
 627                          * Fixme:
 628                          * should we return an error or ignore this failure?
 629                          * dev->brightness->curr is a cached value which stores
 630                          * the correct current backlight level in most cases.
 631                          * ACPI video backlight still works w/ buggy _BQC.
 632                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 633                          */
 634                         acpi_handle_info(device->dev->handle,
 635                                          "%s evaluation failed", buf);
 636                         device->cap._BQC = device->cap._BCQ = 0;
 637                 }
 638         }
 639
 640         *level = device->brightness->curr;
 641         return 0;
 642 }
 643
 644 static int
 645 acpi_video_device_EDID(struct acpi_video_device *device,
 646                        union acpi_object **edid, ssize_t length)
 647 {
 648         int status;
 649         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 650         union acpi_object *obj;
 651         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 652         struct acpi_object_list args = { 1, &arg0 };
 653
 654
 655         *edid = NULL;
 656
 657         if (!device)
 658                 return -ENODEV;
 659         if (length == 128)
 660                 arg0.integer.value = 1;
 661         else if (length == 256)
 662                 arg0.integer.value = 2;
 663         else
 664                 return -EINVAL;
 665
 666         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 667         if (ACPI_FAILURE(status))
 668                 return -ENODEV;
 669
 670         obj = buffer.pointer;
 671
 672         if (obj && obj->type == ACPI_TYPE_BUFFER)
 673                 *edid = obj;
 674         else {
 675                 acpi_handle_info(device->dev->handle, "Invalid _DDC data\n");
 676                 status = -EFAULT;
 677                 kfree(obj);
 678         }
 679
 680         return status;
 681 }
 682
 683 /* bus */
 684
 685 /*
 686  *  Arg:
 687  *      video           : video bus device pointer
 688  *      bios_flag       :
 689  *              0.      The system BIOS should NOT automatically switch(toggle)
 690  *                      the active display output.
 691  *              1.      The system BIOS should automatically switch (toggle) the
 692  *                      active display output. No switch event.
 693  *              2.      The _DGS value should be locked.
 694  *              3.      The system BIOS should not automatically switch (toggle) the
 695  *                      active display output, but instead generate the display switch
 696  *                      event notify code.
 697  *      lcd_flag        :
 698  *              0.      The system BIOS should automatically control the brightness level
 699  *                      of the LCD when:
 700  *                      - the power changes from AC to DC (ACPI appendix B)
 701  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 702  *              1.      The system BIOS should NOT automatically control the brightness
 703  *                      level of the LCD when:
 704  *                      - the power changes from AC to DC (ACPI appendix B)
 705  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 706  *  Return Value:
 707  *              -EINVAL wrong arg.
 708  */
 709
 710 static int
 711 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 712 {
 713         acpi_status status;
 714
 715         if (!video->cap._DOS)
 716                 return 0;
 717
 718         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 719                 return -EINVAL;
 720         video->dos_setting = (lcd_flag << 2) | bios_flag;
 721         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 722                                             (lcd_flag << 2) | bios_flag);
 723         if (ACPI_FAILURE(status))
 724                 return -EIO;
 725
 726         return 0;
 727 }
 728
 729 /*
 730  * Simple comparison function used to sort backlight levels.
 731  */
 732
 733 static int
 734 acpi_video_cmp_level(const void *a, const void *b)
 735 {
 736         return *(int *)a - *(int *)b;
 737 }
 738
 739 /*
 740  * Decides if _BQC/_BCQ for this system is usable
 741  *
 742  * We do this by changing the level first and then read out the current
 743  * brightness level, if the value does not match, find out if it is using
 744  * index. If not, clear the _BQC/_BCQ capability.
 745  */
 746 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 747                                 int max_level, int current_level)
 748 {
 749         struct acpi_video_device_brightness *br = device->brightness;
 750         int result;
 751         unsigned long long level;
 752         int test_level;
 753
 754         /* don't mess with existing known broken systems */
 755         if (bqc_offset_aml_bug_workaround)
 756                 return 0;
 757
 758         /*
 759          * Some systems always report current brightness level as maximum
 760          * through _BQC, we need to test another value for them. However,
 761          * there is a subtlety:
 762          *
 763          * If the _BCL package ordering is descending, the first level
 764          * (br->levels[2]) is likely to be 0, and if the number of levels
 765          * matches the number of steps, we might confuse a returned level to
 766          * mean the index.
 767          *
 768          * For example:
 769          *
 770          *     current_level = max_level = 100
 771          *     test_level = 0
 772          *     returned level = 100
 773          *
 774          * In this case 100 means the level, not the index, and _BCM failed.
 775          * Still, if the _BCL package ordering is descending, the index of
 776          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 777          *
 778          * This causes all _BQC calls to return bogus values causing weird
 779          * behavior from the user's perspective.  For example:
 780          *
 781          * xbacklight -set 10; xbacklight -set 20;
 782          *
 783          * would flash to 90% and then slowly down to the desired level (20).
 784          *
 785          * The solution is simple; test anything other than the first level
 786          * (e.g. 1).
 787          */
 788         test_level = current_level == max_level
 789                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 790                 : max_level;
 791
 792         result = acpi_video_device_lcd_set_level(device, test_level);
 793         if (result)
 794                 return result;
 795
 796         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 797         if (result)
 798                 return result;
 799
 800         if (level != test_level) {
 801                 /* buggy _BQC found, need to find out if it uses index */
 802                 if (level < br->count) {
 803                         if (br->flags._BCL_reversed)
 804                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 805                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 806                                 br->flags._BQC_use_index = 1;
 807                 }
 808
 809                 if (!br->flags._BQC_use_index)
 810                         device->cap._BQC = device->cap._BCQ = 0;
 811         }
 812
 813         return 0;
 814 }
 815
 816 int acpi_video_get_levels(struct acpi_device *device,
 817                           struct acpi_video_device_brightness **dev_br,
 818                           int *pmax_level)
 819 {
 820         union acpi_object *obj = NULL;
 821         int i, max_level = 0, count = 0, level_ac_battery = 0;
 822         union acpi_object *o;
 823         struct acpi_video_device_brightness *br = NULL;
 824         int result = 0;
 825         u32 value;
 826
 827         if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
 828                 acpi_handle_debug(device->handle,
 829                                   "Could not query available 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                 result = -ENOMEM;
 842                 goto out;
 843         }
 844
 845         /*
 846          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 847          * in order to account for buggy BIOS which don't export the first two
 848          * special levels (see below)
 849          */
 850         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 851                                    sizeof(*br->levels),
 852                                    GFP_KERNEL);
 853         if (!br->levels) {
 854                 result = -ENOMEM;
 855                 goto out_free;
 856         }
 857
 858         for (i = 0; i < obj->package.count; i++) {
 859                 o = (union acpi_object *)&obj->package.elements[i];
 860                 if (o->type != ACPI_TYPE_INTEGER) {
 861                         acpi_handle_info(device->handle, "Invalid data\n");
 862                         continue;
 863                 }
 864                 value = (u32) o->integer.value;
 865                 /* Skip duplicate entries */
 866                 if (count > ACPI_VIDEO_FIRST_LEVEL
 867                     && br->levels[count - 1] == value)
 868                         continue;
 869
 870                 br->levels[count] = value;
 871
 872                 if (br->levels[count] > max_level)
 873                         max_level = br->levels[count];
 874                 count++;
 875         }
 876
 877         /*
 878          * some buggy BIOS don't export the levels
 879          * when machine is on AC/Battery in _BCL package.
 880          * In this case, the first two elements in _BCL packages
 881          * are also supported brightness levels that OS should take care of.
 882          */
 883         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 884                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 885                         level_ac_battery++;
 886                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 887                         level_ac_battery++;
 888         }
 889
 890         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 891                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 892                 br->flags._BCL_no_ac_battery_levels = 1;
 893                 for (i = (count - 1 + level_ac_battery);
 894                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 895                         br->levels[i] = br->levels[i - level_ac_battery];
 896                 count += level_ac_battery;
 897         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 898                 acpi_handle_info(device->handle,
 899                                  "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_handle_info(device->handle,
 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;
 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_handle_debug(device->dev->handle, "found %d brightness levels\n",
 989                           br->count - ACPI_VIDEO_FIRST_LEVEL);
 990
 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                 acpi_handle_info(device->dev->handle,
1023                                  "_BCQ is used instead of _BQC\n");
1024                 device->cap._BCQ = 1;
1025         }
1026
1027         if (acpi_has_method(device->dev->handle, "_DDC"))
1028                 device->cap._DDC = 1;
1029 }
1030
1031 /*
1032  *  Arg:
1033  *      device  : video output device (VGA)
1034  *
1035  *  Return Value:
1036  *      None
1037  *
1038  *  Find out all required AML methods defined under the video bus device.
1039  */
1040
1041 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1042 {
1043         if (acpi_has_method(video->device->handle, "_DOS"))
1044                 video->cap._DOS = 1;
1045         if (acpi_has_method(video->device->handle, "_DOD"))
1046                 video->cap._DOD = 1;
1047         if (acpi_has_method(video->device->handle, "_ROM"))
1048                 video->cap._ROM = 1;
1049         if (acpi_has_method(video->device->handle, "_GPD"))
1050                 video->cap._GPD = 1;
1051         if (acpi_has_method(video->device->handle, "_SPD"))
1052                 video->cap._SPD = 1;
1053         if (acpi_has_method(video->device->handle, "_VPO"))
1054                 video->cap._VPO = 1;
1055 }
1056
1057 /*
1058  * Check whether the video bus device has required AML method to
1059  * support the desired features
1060  */
1061
1062 static int acpi_video_bus_check(struct acpi_video_bus *video)
1063 {
1064         acpi_status status = -ENOENT;
1065         struct pci_dev *dev;
1066
1067         if (!video)
1068                 return -EINVAL;
1069
1070         dev = acpi_get_pci_dev(video->device->handle);
1071         if (!dev)
1072                 return -ENODEV;
1073         pci_dev_put(dev);
1074
1075         /*
1076          * Since there is no HID, CID and so on for VGA driver, we have
1077          * to check well known required nodes.
1078          */
1079
1080         /* Does this device support video switching? */
1081         if (video->cap._DOS || video->cap._DOD) {
1082                 if (!video->cap._DOS) {
1083                         pr_info(FW_BUG "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_handle_debug(video->device->handle, "%s: %d\n",
1272                                           __func__, i);
1273                 }
1274         }
1275 }
1276
1277 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1278 {
1279         struct acpi_video_bus *video = device->video;
1280         int i;
1281
1282         /*
1283          * If we have a broken _DOD or we have more than 8 output devices
1284          * under the graphics controller node that we can't proper deal with
1285          * in the operation region code currently, no need to test.
1286          */
1287         if (!video->attached_count || video->child_count > 8)
1288                 return true;
1289
1290         for (i = 0; i < video->attached_count; i++) {
1291                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1292                     (device->device_id & 0xfff))
1293                         return true;
1294         }
1295
1296         return false;
1297 }
1298
1299 /*
1300  *  Arg:
1301  *      video   : video bus device
1302  *
1303  *  Return:
1304  *      < 0     : error
1305  *
1306  *  Call _DOD to enumerate all devices attached to display adapter
1307  *
1308  */
1309
1310 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1311 {
1312         int status;
1313         int count;
1314         int i;
1315         struct acpi_video_enumerated_device *active_list;
1316         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1317         union acpi_object *dod = NULL;
1318         union acpi_object *obj;
1319
1320         if (!video->cap._DOD)
1321                 return AE_NOT_EXIST;
1322
1323         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1324         if (ACPI_FAILURE(status)) {
1325                 acpi_handle_info(video->device->handle,
1326                                  "_DOD evaluation failed: %s\n",
1327                                  acpi_format_exception(status));
1328                 return status;
1329         }
1330
1331         dod = buffer.pointer;
1332         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1333                 acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1334                 status = -EFAULT;
1335                 goto out;
1336         }
1337
1338         acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1339                           dod->package.count);
1340
1341         active_list = kcalloc(1 + dod->package.count,
1342                               sizeof(struct acpi_video_enumerated_device),
1343                               GFP_KERNEL);
1344         if (!active_list) {
1345                 status = -ENOMEM;
1346                 goto out;
1347         }
1348
1349         count = 0;
1350         for (i = 0; i < dod->package.count; i++) {
1351                 obj = &dod->package.elements[i];
1352
1353                 if (obj->type != ACPI_TYPE_INTEGER) {
1354                         acpi_handle_info(video->device->handle,
1355                                          "Invalid _DOD data in element %d\n", i);
1356                         continue;
1357                 }
1358
1359                 active_list[count].value.int_val = obj->integer.value;
1360                 active_list[count].bind_info = NULL;
1361
1362                 acpi_handle_debug(video->device->handle,
1363                                   "_DOD element[%d] = %d\n", i,
1364                                   (int)obj->integer.value);
1365
1366                 count++;
1367         }
1368
1369         kfree(video->attached_array);
1370
1371         video->attached_array = active_list;
1372         video->attached_count = count;
1373
1374 out:
1375         kfree(buffer.pointer);
1376         return status;
1377 }
1378
1379 static int
1380 acpi_video_get_next_level(struct acpi_video_device *device,
1381                           u32 level_current, u32 event)
1382 {
1383         int min, max, min_above, max_below, i, l, delta = 255;
1384         max = max_below = 0;
1385         min = min_above = 255;
1386         /* Find closest level to level_current */
1387         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1388                 l = device->brightness->levels[i];
1389                 if (abs(l - level_current) < abs(delta)) {
1390                         delta = l - level_current;
1391                         if (!delta)
1392                                 break;
1393                 }
1394         }
1395         /* Adjust level_current to closest available level */
1396         level_current += delta;
1397         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1398                 l = device->brightness->levels[i];
1399                 if (l < min)
1400                         min = l;
1401                 if (l > max)
1402                         max = l;
1403                 if (l < min_above && l > level_current)
1404                         min_above = l;
1405                 if (l > max_below && l < level_current)
1406                         max_below = l;
1407         }
1408
1409         switch (event) {
1410         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1411                 return (level_current < max) ? min_above : min;
1412         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1413                 return (level_current < max) ? min_above : max;
1414         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1415                 return (level_current > min) ? max_below : min;
1416         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1417         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1418                 return 0;
1419         default:
1420                 return level_current;
1421         }
1422 }
1423
1424 static void
1425 acpi_video_switch_brightness(struct work_struct *work)
1426 {
1427         struct acpi_video_device *device = container_of(to_delayed_work(work),
1428                              struct acpi_video_device, switch_brightness_work);
1429         unsigned long long level_current, level_next;
1430         int event = device->switch_brightness_event;
1431         int result = -EINVAL;
1432
1433         /* no warning message if acpi_backlight=vendor or a quirk is used */
1434         if (!device->backlight)
1435                 return;
1436
1437         if (!device->brightness)
1438                 goto out;
1439
1440         result = acpi_video_device_lcd_get_level_current(device,
1441                                                          &level_current,
1442                                                          false);
1443         if (result)
1444                 goto out;
1445
1446         level_next = acpi_video_get_next_level(device, level_current, event);
1447
1448         result = acpi_video_device_lcd_set_level(device, level_next);
1449
1450         if (!result)
1451                 backlight_force_update(device->backlight,
1452                                        BACKLIGHT_UPDATE_HOTKEY);
1453
1454 out:
1455         if (result)
1456                 acpi_handle_info(device->dev->handle,
1457                                  "Failed to switch brightness\n");
1458 }
1459
1460 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1461                         void **edid)
1462 {
1463         struct acpi_video_bus *video;
1464         struct acpi_video_device *video_device;
1465         union acpi_object *buffer = NULL;
1466         acpi_status status;
1467         int i, length;
1468
1469         if (!device || !acpi_driver_data(device))
1470                 return -EINVAL;
1471
1472         video = acpi_driver_data(device);
1473
1474         for (i = 0; i < video->attached_count; i++) {
1475                 video_device = video->attached_array[i].bind_info;
1476                 length = 256;
1477
1478                 if (!video_device)
1479                         continue;
1480
1481                 if (!video_device->cap._DDC)
1482                         continue;
1483
1484                 if (type) {
1485                         switch (type) {
1486                         case ACPI_VIDEO_DISPLAY_CRT:
1487                                 if (!video_device->flags.crt)
1488                                         continue;
1489                                 break;
1490                         case ACPI_VIDEO_DISPLAY_TV:
1491                                 if (!video_device->flags.tvout)
1492                                         continue;
1493                                 break;
1494                         case ACPI_VIDEO_DISPLAY_DVI:
1495                                 if (!video_device->flags.dvi)
1496                                         continue;
1497                                 break;
1498                         case ACPI_VIDEO_DISPLAY_LCD:
1499                                 if (!video_device->flags.lcd)
1500                                         continue;
1501                                 break;
1502                         }
1503                 } else if (video_device->device_id != device_id) {
1504                         continue;
1505                 }
1506
1507                 status = acpi_video_device_EDID(video_device, &buffer, length);
1508
1509                 if (ACPI_FAILURE(status) || !buffer ||
1510                     buffer->type != ACPI_TYPE_BUFFER) {
1511                         length = 128;
1512                         status = acpi_video_device_EDID(video_device, &buffer,
1513                                                         length);
1514                         if (ACPI_FAILURE(status) || !buffer ||
1515                             buffer->type != ACPI_TYPE_BUFFER) {
1516                                 continue;
1517                         }
1518                 }
1519
1520                 *edid = buffer->buffer.pointer;
1521                 return length;
1522         }
1523
1524         return -ENODEV;
1525 }
1526 EXPORT_SYMBOL(acpi_video_get_edid);
1527
1528 static int
1529 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1530                            struct acpi_device *device)
1531 {
1532         int status = 0;
1533         struct acpi_device *dev;
1534
1535         /*
1536          * There are systems where video module known to work fine regardless
1537          * of broken _DOD and ignoring returned value here doesn't cause
1538          * any issues later.
1539          */
1540         acpi_video_device_enumerate(video);
1541
1542         list_for_each_entry(dev, &device->children, node) {
1543
1544                 status = acpi_video_bus_get_one_device(dev, video);
1545                 if (status) {
1546                         dev_err(&dev->dev, "Can't attach device\n");
1547                         break;
1548                 }
1549                 video->child_count++;
1550         }
1551         return status;
1552 }
1553
1554 /* acpi_video interface */
1555
1556 /*
1557  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1558  * perform any automatic brightness change on receiving a notification.
1559  */
1560 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1561 {
1562         return acpi_video_bus_DOS(video, 0,
1563                                   acpi_osi_is_win8() ? 1 : 0);
1564 }
1565
1566 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1567 {
1568         return acpi_video_bus_DOS(video, 0,
1569                                   acpi_osi_is_win8() ? 0 : 1);
1570 }
1571
1572 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1573 {
1574         struct acpi_video_bus *video = acpi_driver_data(device);
1575         struct input_dev *input;
1576         int keycode = 0;
1577
1578         if (!video || !video->input)
1579                 return;
1580
1581         input = video->input;
1582
1583         switch (event) {
1584         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1585                                          * most likely via hotkey. */
1586                 keycode = KEY_SWITCHVIDEOMODE;
1587                 break;
1588
1589         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1590                                          * connector. */
1591                 acpi_video_device_enumerate(video);
1592                 acpi_video_device_rebind(video);
1593                 keycode = KEY_SWITCHVIDEOMODE;
1594                 break;
1595
1596         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1597                 keycode = KEY_SWITCHVIDEOMODE;
1598                 break;
1599         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1600                 keycode = KEY_VIDEO_NEXT;
1601                 break;
1602         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1603                 keycode = KEY_VIDEO_PREV;
1604                 break;
1605
1606         default:
1607                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1608                                   event);
1609                 break;
1610         }
1611
1612         if (acpi_notifier_call_chain(device, event, 0))
1613                 /* Something vetoed the keypress. */
1614                 keycode = 0;
1615
1616         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1617                 input_report_key(input, keycode, 1);
1618                 input_sync(input);
1619                 input_report_key(input, keycode, 0);
1620                 input_sync(input);
1621         }
1622
1623         return;
1624 }
1625
1626 static void brightness_switch_event(struct acpi_video_device *video_device,
1627                                     u32 event)
1628 {
1629         if (!brightness_switch_enabled)
1630                 return;
1631
1632         video_device->switch_brightness_event = event;
1633         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1634 }
1635
1636 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1637 {
1638         struct acpi_video_device *video_device = data;
1639         struct acpi_device *device = NULL;
1640         struct acpi_video_bus *bus;
1641         struct input_dev *input;
1642         int keycode = 0;
1643
1644         if (!video_device)
1645                 return;
1646
1647         device = video_device->dev;
1648         bus = video_device->video;
1649         input = bus->input;
1650
1651         if (hw_changes_brightness > 0) {
1652                 if (video_device->backlight)
1653                         backlight_force_update(video_device->backlight,
1654                                                BACKLIGHT_UPDATE_HOTKEY);
1655                 acpi_notifier_call_chain(device, event, 0);
1656                 return;
1657         }
1658
1659         switch (event) {
1660         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1661                 brightness_switch_event(video_device, event);
1662                 keycode = KEY_BRIGHTNESS_CYCLE;
1663                 break;
1664         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1665                 brightness_switch_event(video_device, event);
1666                 keycode = KEY_BRIGHTNESSUP;
1667                 break;
1668         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1669                 brightness_switch_event(video_device, event);
1670                 keycode = KEY_BRIGHTNESSDOWN;
1671                 break;
1672         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1673                 brightness_switch_event(video_device, event);
1674                 keycode = KEY_BRIGHTNESS_ZERO;
1675                 break;
1676         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1677                 brightness_switch_event(video_device, event);
1678                 keycode = KEY_DISPLAY_OFF;
1679                 break;
1680         default:
1681                 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1682                 break;
1683         }
1684
1685         acpi_notifier_call_chain(device, event, 0);
1686
1687         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1688                 input_report_key(input, keycode, 1);
1689                 input_sync(input);
1690                 input_report_key(input, keycode, 0);
1691                 input_sync(input);
1692         }
1693
1694         return;
1695 }
1696
1697 static int acpi_video_resume(struct notifier_block *nb,
1698                                 unsigned long val, void *ign)
1699 {
1700         struct acpi_video_bus *video;
1701         struct acpi_video_device *video_device;
1702         int i;
1703
1704         switch (val) {
1705         case PM_HIBERNATION_PREPARE:
1706         case PM_SUSPEND_PREPARE:
1707         case PM_RESTORE_PREPARE:
1708                 return NOTIFY_DONE;
1709         }
1710
1711         video = container_of(nb, struct acpi_video_bus, pm_nb);
1712
1713         dev_info(&video->device->dev, "Restoring backlight state\n");
1714
1715         for (i = 0; i < video->attached_count; i++) {
1716                 video_device = video->attached_array[i].bind_info;
1717                 if (video_device && video_device->brightness)
1718                         acpi_video_device_lcd_set_level(video_device,
1719                                         video_device->brightness->curr);
1720         }
1721
1722         return NOTIFY_OK;
1723 }
1724
1725 static acpi_status
1726 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1727                         void **return_value)
1728 {
1729         struct acpi_device *device = context;
1730         struct acpi_device *sibling;
1731         int result;
1732
1733         if (handle == device->handle)
1734                 return AE_CTRL_TERMINATE;
1735
1736         result = acpi_bus_get_device(handle, &sibling);
1737         if (result)
1738                 return AE_OK;
1739
1740         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1741                         return AE_ALREADY_EXISTS;
1742
1743         return AE_OK;
1744 }
1745
1746 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1747 {
1748         struct backlight_properties props;
1749         struct pci_dev *pdev;
1750         acpi_handle acpi_parent;
1751         struct device *parent = NULL;
1752         int result;
1753         static int count;
1754         char *name;
1755
1756         result = acpi_video_init_brightness(device);
1757         if (result)
1758                 return;
1759
1760         if (disable_backlight_sysfs_if > 0)
1761                 return;
1762
1763         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1764         if (!name)
1765                 return;
1766         count++;
1767
1768         acpi_get_parent(device->dev->handle, &acpi_parent);
1769
1770         pdev = acpi_get_pci_dev(acpi_parent);
1771         if (pdev) {
1772                 parent = &pdev->dev;
1773                 pci_dev_put(pdev);
1774         }
1775
1776         memset(&props, 0, sizeof(struct backlight_properties));
1777         props.type = BACKLIGHT_FIRMWARE;
1778         props.max_brightness =
1779                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1780         device->backlight = backlight_device_register(name,
1781                                                       parent,
1782                                                       device,
1783                                                       &acpi_backlight_ops,
1784                                                       &props);
1785         kfree(name);
1786         if (IS_ERR(device->backlight)) {
1787                 device->backlight = NULL;
1788                 return;
1789         }
1790
1791         /*
1792          * Save current brightness level in case we have to restore it
1793          * before acpi_video_device_lcd_set_level() is called next time.
1794          */
1795         device->backlight->props.brightness =
1796                         acpi_video_get_brightness(device->backlight);
1797
1798         device->cooling_dev = thermal_cooling_device_register("LCD",
1799                                 device->dev, &video_cooling_ops);
1800         if (IS_ERR(device->cooling_dev)) {
1801                 /*
1802                  * Set cooling_dev to NULL so we don't crash trying to free it.
1803                  * Also, why the hell we are returning early and not attempt to
1804                  * register video output if cooling device registration failed?
1805                  * -- dtor
1806                  */
1807                 device->cooling_dev = NULL;
1808                 return;
1809         }
1810
1811         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1812                  device->cooling_dev->id);
1813         result = sysfs_create_link(&device->dev->dev.kobj,
1814                         &device->cooling_dev->device.kobj,
1815                         "thermal_cooling");
1816         if (result)
1817                 pr_info("sysfs link creation failed\n");
1818
1819         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1820                         &device->dev->dev.kobj, "device");
1821         if (result)
1822                 pr_info("Reverse sysfs link creation failed\n");
1823 }
1824
1825 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1826 {
1827         struct acpi_video_device *dev;
1828         union acpi_object *levels;
1829
1830         mutex_lock(&video->device_list_lock);
1831         list_for_each_entry(dev, &video->video_device_list, entry) {
1832                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1833                         kfree(levels);
1834         }
1835         mutex_unlock(&video->device_list_lock);
1836 }
1837
1838 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1839 {
1840         /*
1841          * Do not create backlight device for video output
1842          * device that is not in the enumerated list.
1843          */
1844         if (!acpi_video_device_in_dod(dev)) {
1845                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1846                 return false;
1847         }
1848
1849         if (only_lcd)
1850                 return dev->flags.lcd;
1851         return true;
1852 }
1853
1854 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1855 {
1856         struct acpi_video_device *dev;
1857
1858         if (video->backlight_registered)
1859                 return 0;
1860
1861         acpi_video_run_bcl_for_osi(video);
1862
1863         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1864                 return 0;
1865
1866         mutex_lock(&video->device_list_lock);
1867         list_for_each_entry(dev, &video->video_device_list, entry) {
1868                 if (acpi_video_should_register_backlight(dev))
1869                         acpi_video_dev_register_backlight(dev);
1870         }
1871         mutex_unlock(&video->device_list_lock);
1872
1873         video->backlight_registered = true;
1874
1875         video->pm_nb.notifier_call = acpi_video_resume;
1876         video->pm_nb.priority = 0;
1877         return register_pm_notifier(&video->pm_nb);
1878 }
1879
1880 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1881 {
1882         if (device->backlight) {
1883                 backlight_device_unregister(device->backlight);
1884                 device->backlight = NULL;
1885         }
1886         if (device->brightness) {
1887                 kfree(device->brightness->levels);
1888                 kfree(device->brightness);
1889                 device->brightness = NULL;
1890         }
1891         if (device->cooling_dev) {
1892                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1893                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1894                 thermal_cooling_device_unregister(device->cooling_dev);
1895                 device->cooling_dev = NULL;
1896         }
1897 }
1898
1899 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1900 {
1901         struct acpi_video_device *dev;
1902         int error;
1903
1904         if (!video->backlight_registered)
1905                 return 0;
1906
1907         error = unregister_pm_notifier(&video->pm_nb);
1908
1909         mutex_lock(&video->device_list_lock);
1910         list_for_each_entry(dev, &video->video_device_list, entry)
1911                 acpi_video_dev_unregister_backlight(dev);
1912         mutex_unlock(&video->device_list_lock);
1913
1914         video->backlight_registered = false;
1915
1916         return error;
1917 }
1918
1919 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1920 {
1921         acpi_status status;
1922         struct acpi_device *adev = device->dev;
1923
1924         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1925                                              acpi_video_device_notify, device);
1926         if (ACPI_FAILURE(status))
1927                 dev_err(&adev->dev, "Error installing notify handler\n");
1928         else
1929                 device->flags.notify = 1;
1930 }
1931
1932 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1933 {
1934         struct input_dev *input;
1935         struct acpi_video_device *dev;
1936         int error;
1937
1938         video->input = input = input_allocate_device();
1939         if (!input) {
1940                 error = -ENOMEM;
1941                 goto out;
1942         }
1943
1944         error = acpi_video_bus_start_devices(video);
1945         if (error)
1946                 goto err_free_input;
1947
1948         snprintf(video->phys, sizeof(video->phys),
1949                         "%s/video/input0", acpi_device_hid(video->device));
1950
1951         input->name = acpi_device_name(video->device);
1952         input->phys = video->phys;
1953         input->id.bustype = BUS_HOST;
1954         input->id.product = 0x06;
1955         input->dev.parent = &video->device->dev;
1956         input->evbit[0] = BIT(EV_KEY);
1957         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1958         set_bit(KEY_VIDEO_NEXT, input->keybit);
1959         set_bit(KEY_VIDEO_PREV, input->keybit);
1960         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1961         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1962         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1963         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1964         set_bit(KEY_DISPLAY_OFF, input->keybit);
1965
1966         error = input_register_device(input);
1967         if (error)
1968                 goto err_stop_dev;
1969
1970         mutex_lock(&video->device_list_lock);
1971         list_for_each_entry(dev, &video->video_device_list, entry)
1972                 acpi_video_dev_add_notify_handler(dev);
1973         mutex_unlock(&video->device_list_lock);
1974
1975         return 0;
1976
1977 err_stop_dev:
1978         acpi_video_bus_stop_devices(video);
1979 err_free_input:
1980         input_free_device(input);
1981         video->input = NULL;
1982 out:
1983         return error;
1984 }
1985
1986 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1987 {
1988         if (dev->flags.notify) {
1989                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1990                                            acpi_video_device_notify);
1991                 dev->flags.notify = 0;
1992         }
1993 }
1994
1995 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1996 {
1997         struct acpi_video_device *dev;
1998
1999         mutex_lock(&video->device_list_lock);
2000         list_for_each_entry(dev, &video->video_device_list, entry)
2001                 acpi_video_dev_remove_notify_handler(dev);
2002         mutex_unlock(&video->device_list_lock);
2003
2004         acpi_video_bus_stop_devices(video);
2005         input_unregister_device(video->input);
2006         video->input = NULL;
2007 }
2008
2009 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
2010 {
2011         struct acpi_video_device *dev, *next;
2012
2013         mutex_lock(&video->device_list_lock);
2014         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
2015                 list_del(&dev->entry);
2016                 kfree(dev);
2017         }
2018         mutex_unlock(&video->device_list_lock);
2019
2020         return 0;
2021 }
2022
2023 static int instance;
2024
2025 static int acpi_video_bus_add(struct acpi_device *device)
2026 {
2027         struct acpi_video_bus *video;
2028         int error;
2029         acpi_status status;
2030
2031         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2032                                 device->parent->handle, 1,
2033                                 acpi_video_bus_match, NULL,
2034                                 device, NULL);
2035         if (status == AE_ALREADY_EXISTS) {
2036                 pr_info(FW_BUG
2037                         "Duplicate ACPI video bus devices for the"
2038                         " same VGA controller, please try module "
2039                         "parameter \"video.allow_duplicates=1\""
2040                         "if the current driver doesn't work.\n");
2041                 if (!allow_duplicates)
2042                         return -ENODEV;
2043         }
2044
2045         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2046         if (!video)
2047                 return -ENOMEM;
2048
2049         /* a hack to fix the duplicate name "VID" problem on T61 */
2050         if (!strcmp(device->pnp.bus_id, "VID")) {
2051                 if (instance)
2052                         device->pnp.bus_id[3] = '0' + instance;
2053                 instance++;
2054         }
2055         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2056         if (!strcmp(device->pnp.bus_id, "VGA")) {
2057                 if (instance)
2058                         device->pnp.bus_id[3] = '0' + instance;
2059                 instance++;
2060         }
2061
2062         video->device = device;
2063         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2064         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2065         device->driver_data = video;
2066
2067         acpi_video_bus_find_cap(video);
2068         error = acpi_video_bus_check(video);
2069         if (error)
2070                 goto err_free_video;
2071
2072         mutex_init(&video->device_list_lock);
2073         INIT_LIST_HEAD(&video->video_device_list);
2074
2075         error = acpi_video_bus_get_devices(video, device);
2076         if (error)
2077                 goto err_put_video;
2078
2079         pr_info("%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2080                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2081                video->flags.multihead ? "yes" : "no",
2082                video->flags.rom ? "yes" : "no",
2083                video->flags.post ? "yes" : "no");
2084         mutex_lock(&video_list_lock);
2085         list_add_tail(&video->entry, &video_bus_head);
2086         mutex_unlock(&video_list_lock);
2087
2088         acpi_video_bus_register_backlight(video);
2089         acpi_video_bus_add_notify_handler(video);
2090
2091         return 0;
2092
2093 err_put_video:
2094         acpi_video_bus_put_devices(video);
2095         kfree(video->attached_array);
2096 err_free_video:
2097         kfree(video);
2098         device->driver_data = NULL;
2099
2100         return error;
2101 }
2102
2103 static int acpi_video_bus_remove(struct acpi_device *device)
2104 {
2105         struct acpi_video_bus *video = NULL;
2106
2107
2108         if (!device || !acpi_driver_data(device))
2109                 return -EINVAL;
2110
2111         video = acpi_driver_data(device);
2112
2113         acpi_video_bus_remove_notify_handler(video);
2114         acpi_video_bus_unregister_backlight(video);
2115         acpi_video_bus_put_devices(video);
2116
2117         mutex_lock(&video_list_lock);
2118         list_del(&video->entry);
2119         mutex_unlock(&video_list_lock);
2120
2121         kfree(video->attached_array);
2122         kfree(video);
2123
2124         return 0;
2125 }
2126
2127 static int __init is_i740(struct pci_dev *dev)
2128 {
2129         if (dev->device == 0x00D1)
2130                 return 1;
2131         if (dev->device == 0x7000)
2132                 return 1;
2133         return 0;
2134 }
2135
2136 static int __init intel_opregion_present(void)
2137 {
2138         int opregion = 0;
2139         struct pci_dev *dev = NULL;
2140         u32 address;
2141
2142         for_each_pci_dev(dev) {
2143                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2144                         continue;
2145                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2146                         continue;
2147                 /* We don't want to poke around undefined i740 registers */
2148                 if (is_i740(dev))
2149                         continue;
2150                 pci_read_config_dword(dev, 0xfc, &address);
2151                 if (!address)
2152                         continue;
2153                 opregion = 1;
2154         }
2155         return opregion;
2156 }
2157
2158 /* Check if the chassis-type indicates there is no builtin LCD panel */
2159 static bool dmi_is_desktop(void)
2160 {
2161         const char *chassis_type;
2162         unsigned long type;
2163
2164         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2165         if (!chassis_type)
2166                 return false;
2167
2168         if (kstrtoul(chassis_type, 10, &type) != 0)
2169                 return false;
2170
2171         switch (type) {
2172         case 0x03: /* Desktop */
2173         case 0x04: /* Low Profile Desktop */
2174         case 0x05: /* Pizza Box */
2175         case 0x06: /* Mini Tower */
2176         case 0x07: /* Tower */
2177         case 0x10: /* Lunch Box */
2178         case 0x11: /* Main Server Chassis */
2179                 return true;
2180         }
2181
2182         return false;
2183 }
2184
2185 /*
2186  * We're seeing a lot of bogus backlight interfaces on newer machines
2187  * without a LCD such as desktops, servers and HDMI sticks. Checking the
2188  * lcd flag fixes this, enable this by default on any machines which are:
2189  * 1.  Win8 ready (where we also prefer the native backlight driver, so
2190  *     normally the acpi_video code should not register there anyways); *and*
2191  * 2.1 Report a desktop/server DMI chassis-type, or
2192  * 2.2 Are an ACPI-reduced-hardware platform (and thus won't use the EC for
2193        backlight control)
2194  */
2195 static bool should_check_lcd_flag(void)
2196 {
2197         if (!acpi_osi_is_win8())
2198                 return false;
2199
2200         if (dmi_is_desktop())
2201                 return true;
2202
2203         if (acpi_reduced_hardware())
2204                 return true;
2205
2206         return false;
2207 }
2208
2209 int acpi_video_register(void)
2210 {
2211         int ret = 0;
2212
2213         mutex_lock(&register_count_mutex);
2214         if (register_count) {
2215                 /*
2216                  * if the function of acpi_video_register is already called,
2217                  * don't register the acpi_video_bus again and return no error.
2218                  */
2219                 goto leave;
2220         }
2221
2222         if (only_lcd == -1)
2223                 only_lcd = should_check_lcd_flag();
2224
2225         dmi_check_system(video_dmi_table);
2226
2227         ret = acpi_bus_register_driver(&acpi_video_bus);
2228         if (ret)
2229                 goto leave;
2230
2231         /*
2232          * When the acpi_video_bus is loaded successfully, increase
2233          * the counter reference.
2234          */
2235         register_count = 1;
2236
2237 leave:
2238         mutex_unlock(&register_count_mutex);
2239         return ret;
2240 }
2241 EXPORT_SYMBOL(acpi_video_register);
2242
2243 void acpi_video_unregister(void)
2244 {
2245         mutex_lock(&register_count_mutex);
2246         if (register_count) {
2247                 acpi_bus_unregister_driver(&acpi_video_bus);
2248                 register_count = 0;
2249         }
2250         mutex_unlock(&register_count_mutex);
2251 }
2252 EXPORT_SYMBOL(acpi_video_unregister);
2253
2254 void acpi_video_unregister_backlight(void)
2255 {
2256         struct acpi_video_bus *video;
2257
2258         mutex_lock(&register_count_mutex);
2259         if (register_count) {
2260                 mutex_lock(&video_list_lock);
2261                 list_for_each_entry(video, &video_bus_head, entry)
2262                         acpi_video_bus_unregister_backlight(video);
2263                 mutex_unlock(&video_list_lock);
2264         }
2265         mutex_unlock(&register_count_mutex);
2266 }
2267
2268 bool acpi_video_handles_brightness_key_presses(void)
2269 {
2270         bool have_video_busses;
2271
2272         mutex_lock(&video_list_lock);
2273         have_video_busses = !list_empty(&video_bus_head);
2274         mutex_unlock(&video_list_lock);
2275
2276         return have_video_busses &&
2277                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2278 }
2279 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2280
2281 /*
2282  * This is kind of nasty. Hardware using Intel chipsets may require
2283  * the video opregion code to be run first in order to initialise
2284  * state before any ACPI video calls are made. To handle this we defer
2285  * registration of the video class until the opregion code has run.
2286  */
2287
2288 static int __init acpi_video_init(void)
2289 {
2290         /*
2291          * Let the module load even if ACPI is disabled (e.g. due to
2292          * a broken BIOS) so that i915.ko can still be loaded on such
2293          * old systems without an AcpiOpRegion.
2294          *
2295          * acpi_video_register() will report -ENODEV later as well due
2296          * to acpi_disabled when i915.ko tries to register itself afterwards.
2297          */
2298         if (acpi_disabled)
2299                 return 0;
2300
2301         if (intel_opregion_present())
2302                 return 0;
2303
2304         return acpi_video_register();
2305 }
2306
2307 static void __exit acpi_video_exit(void)
2308 {
2309         acpi_video_detect_exit();
2310         acpi_video_unregister();
2311
2312         return;
2313 }
2314
2315 module_init(acpi_video_init);
2316 module_exit(acpi_video_exit);