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 bool may_report_brightness_keys;
  77 static int register_count;
  78 static DEFINE_MUTEX(register_count_mutex);
  79 static DEFINE_MUTEX(video_list_lock);
  80 static LIST_HEAD(video_bus_head);
  81 static int acpi_video_bus_add(struct acpi_device *device);
  82 static int acpi_video_bus_remove(struct acpi_device *device);
  83 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  84 void acpi_video_detect_exit(void);
  85
  86 /*
  87  * Indices in the _BCL method response: the first two items are special,
  88  * the rest are all supported levels.
  89  *
  90  * See page 575 of the ACPI spec 3.0
  91  */
  92 enum acpi_video_level_idx {
  93         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
  94         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
  95         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
  96 };
  97
  98 static const struct acpi_device_id video_device_ids[] = {
  99         {ACPI_VIDEO_HID, 0},
 100         {"", 0},
 101 };
 102 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 103
 104 static struct acpi_driver acpi_video_bus = {
 105         .name = "video",
 106         .class = ACPI_VIDEO_CLASS,
 107         .ids = video_device_ids,
 108         .ops = {
 109                 .add = acpi_video_bus_add,
 110                 .remove = acpi_video_bus_remove,
 111                 .notify = acpi_video_bus_notify,
 112                 },
 113 };
 114
 115 struct acpi_video_bus_flags {
 116         u8 multihead:1;         /* can switch video heads */
 117         u8 rom:1;               /* can retrieve a video rom */
 118         u8 post:1;              /* can configure the head to */
 119         u8 reserved:5;
 120 };
 121
 122 struct acpi_video_bus_cap {
 123         u8 _DOS:1;              /* Enable/Disable output switching */
 124         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 125         u8 _ROM:1;              /* Get ROM Data */
 126         u8 _GPD:1;              /* Get POST Device */
 127         u8 _SPD:1;              /* Set POST Device */
 128         u8 _VPO:1;              /* Video POST Options */
 129         u8 reserved:2;
 130 };
 131
 132 struct acpi_video_device_attrib {
 133         u32 display_index:4;    /* A zero-based instance of the Display */
 134         u32 display_port_attachment:4;  /* This field differentiates the display type */
 135         u32 display_type:4;     /* Describe the specific type in use */
 136         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 137         u32 bios_can_detect:1;  /* BIOS can detect the device */
 138         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 139                                    the VGA device. */
 140         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 141         u32 reserved:10;        /* Must be 0 */
 142
 143         /*
 144          * The device ID might not actually follow the scheme described by this
 145          * struct acpi_video_device_attrib. If it does, then this bit
 146          * device_id_scheme is set; otherwise, other fields should be ignored.
 147          *
 148          * (but also see the global flag device_id_scheme)
 149          */
 150         u32 device_id_scheme:1;
 151 };
 152
 153 struct acpi_video_enumerated_device {
 154         union {
 155                 u32 int_val;
 156                 struct acpi_video_device_attrib attrib;
 157         } value;
 158         struct acpi_video_device *bind_info;
 159 };
 160
 161 struct acpi_video_bus {
 162         struct acpi_device *device;
 163         bool backlight_registered;
 164         u8 dos_setting;
 165         struct acpi_video_enumerated_device *attached_array;
 166         u8 attached_count;
 167         u8 child_count;
 168         struct acpi_video_bus_cap cap;
 169         struct acpi_video_bus_flags flags;
 170         struct list_head video_device_list;
 171         struct mutex device_list_lock;  /* protects video_device_list */
 172         struct list_head entry;
 173         struct input_dev *input;
 174         char phys[32];  /* for input device */
 175         struct notifier_block pm_nb;
 176 };
 177
 178 struct acpi_video_device_flags {
 179         u8 crt:1;
 180         u8 lcd:1;
 181         u8 tvout:1;
 182         u8 dvi:1;
 183         u8 bios:1;
 184         u8 unknown:1;
 185         u8 notify:1;
 186         u8 reserved:1;
 187 };
 188
 189 struct acpi_video_device_cap {
 190         u8 _ADR:1;              /* Return the unique ID */
 191         u8 _BCL:1;              /* Query list of brightness control levels supported */
 192         u8 _BCM:1;              /* Set the brightness level */
 193         u8 _BQC:1;              /* Get current brightness level */
 194         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 195         u8 _DDC:1;              /* Return the EDID for this device */
 196 };
 197
 198 struct acpi_video_device {
 199         unsigned long device_id;
 200         struct acpi_video_device_flags flags;
 201         struct acpi_video_device_cap cap;
 202         struct list_head entry;
 203         struct delayed_work switch_brightness_work;
 204         int switch_brightness_event;
 205         struct acpi_video_bus *video;
 206         struct acpi_device *dev;
 207         struct acpi_video_device_brightness *brightness;
 208         struct backlight_device *backlight;
 209         struct thermal_cooling_device *cooling_dev;
 210 };
 211
 212 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 213 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 214 static void acpi_video_device_bind(struct acpi_video_bus *video,
 215                                    struct acpi_video_device *device);
 216 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 217 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 218                         int level);
 219 static int acpi_video_device_lcd_get_level_current(
 220                         struct acpi_video_device *device,
 221                         unsigned long long *level, bool raw);
 222 static int acpi_video_get_next_level(struct acpi_video_device *device,
 223                                      u32 level_current, u32 event);
 224 static void acpi_video_switch_brightness(struct work_struct *work);
 225
 226 /* backlight device sysfs support */
 227 static int acpi_video_get_brightness(struct backlight_device *bd)
 228 {
 229         unsigned long long cur_level;
 230         int i;
 231         struct acpi_video_device *vd = bl_get_data(bd);
 232
 233         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 234                 return -EINVAL;
 235         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 236                 if (vd->brightness->levels[i] == cur_level)
 237                         return i - ACPI_VIDEO_FIRST_LEVEL;
 238         }
 239         return 0;
 240 }
 241
 242 static int acpi_video_set_brightness(struct backlight_device *bd)
 243 {
 244         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 245         struct acpi_video_device *vd = bl_get_data(bd);
 246
 247         cancel_delayed_work(&vd->switch_brightness_work);
 248         return acpi_video_device_lcd_set_level(vd,
 249                                 vd->brightness->levels[request_level]);
 250 }
 251
 252 static const struct backlight_ops acpi_backlight_ops = {
 253         .get_brightness = acpi_video_get_brightness,
 254         .update_status  = acpi_video_set_brightness,
 255 };
 256
 257 /* thermal cooling device callbacks */
 258 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 259                                unsigned long *state)
 260 {
 261         struct acpi_device *device = cooling_dev->devdata;
 262         struct acpi_video_device *video = acpi_driver_data(device);
 263
 264         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 265         return 0;
 266 }
 267
 268 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 269                                unsigned long *state)
 270 {
 271         struct acpi_device *device = cooling_dev->devdata;
 272         struct acpi_video_device *video = acpi_driver_data(device);
 273         unsigned long long level;
 274         int offset;
 275
 276         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 277                 return -EINVAL;
 278         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 279              offset++)
 280                 if (level == video->brightness->levels[offset]) {
 281                         *state = video->brightness->count - offset - 1;
 282                         return 0;
 283                 }
 284
 285         return -EINVAL;
 286 }
 287
 288 static int
 289 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 290 {
 291         struct acpi_device *device = cooling_dev->devdata;
 292         struct acpi_video_device *video = acpi_driver_data(device);
 293         int level;
 294
 295         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 296                 return -EINVAL;
 297
 298         state = video->brightness->count - state;
 299         level = video->brightness->levels[state - 1];
 300         return acpi_video_device_lcd_set_level(video, level);
 301 }
 302
 303 static const struct thermal_cooling_device_ops video_cooling_ops = {
 304         .get_max_state = video_get_max_state,
 305         .get_cur_state = video_get_cur_state,
 306         .set_cur_state = video_set_cur_state,
 307 };
 308
 309 /*
 310  * --------------------------------------------------------------------------
 311  *                             Video Management
 312  * --------------------------------------------------------------------------
 313  */
 314
 315 static int
 316 acpi_video_device_lcd_query_levels(acpi_handle handle,
 317                                    union acpi_object **levels)
 318 {
 319         int status;
 320         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 321         union acpi_object *obj;
 322
 323
 324         *levels = NULL;
 325
 326         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 327         if (ACPI_FAILURE(status))
 328                 return status;
 329         obj = (union acpi_object *)buffer.pointer;
 330         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 331                 acpi_handle_info(handle, "Invalid _BCL data\n");
 332                 status = -EFAULT;
 333                 goto err;
 334         }
 335
 336         *levels = obj;
 337
 338         return 0;
 339
 340 err:
 341         kfree(buffer.pointer);
 342
 343         return status;
 344 }
 345
 346 static int
 347 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 348 {
 349         int status;
 350         int state;
 351
 352         status = acpi_execute_simple_method(device->dev->handle,
 353                                             "_BCM", level);
 354         if (ACPI_FAILURE(status)) {
 355                 acpi_handle_info(device->dev->handle, "_BCM evaluation failed\n");
 356                 return -EIO;
 357         }
 358
 359         device->brightness->curr = level;
 360         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 361              state++)
 362                 if (level == device->brightness->levels[state]) {
 363                         if (device->backlight)
 364                                 device->backlight->props.brightness =
 365                                         state - ACPI_VIDEO_FIRST_LEVEL;
 366                         return 0;
 367                 }
 368
 369         acpi_handle_info(device->dev->handle, "Current brightness invalid\n");
 370         return -EINVAL;
 371 }
 372
 373 /*
 374  * For some buggy _BQC methods, we need to add a constant value to
 375  * the _BQC return value to get the actual current brightness level
 376  */
 377
 378 static int bqc_offset_aml_bug_workaround;
 379 static int video_set_bqc_offset(const struct dmi_system_id *d)
 380 {
 381         bqc_offset_aml_bug_workaround = 9;
 382         return 0;
 383 }
 384
 385 static int video_disable_backlight_sysfs_if(
 386         const struct dmi_system_id *d)
 387 {
 388         if (disable_backlight_sysfs_if == -1)
 389                 disable_backlight_sysfs_if = 1;
 390         return 0;
 391 }
 392
 393 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 394 {
 395         device_id_scheme = true;
 396         return 0;
 397 }
 398
 399 static int video_enable_only_lcd(const struct dmi_system_id *d)
 400 {
 401         only_lcd = true;
 402         return 0;
 403 }
 404
 405 static int video_set_report_key_events(const struct dmi_system_id *id)
 406 {
 407         if (report_key_events == -1)
 408                 report_key_events = (uintptr_t)id->driver_data;
 409         return 0;
 410 }
 411
 412 static int video_hw_changes_brightness(
 413         const struct dmi_system_id *d)
 414 {
 415         if (hw_changes_brightness == -1)
 416                 hw_changes_brightness = 1;
 417         return 0;
 418 }
 419
 420 static const struct dmi_system_id video_dmi_table[] = {
 421         /*
 422          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 423          */
 424         {
 425          .callback = video_set_bqc_offset,
 426          .ident = "Acer Aspire 5720",
 427          .matches = {
 428                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 429                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 430                 },
 431         },
 432         {
 433          .callback = video_set_bqc_offset,
 434          .ident = "Acer Aspire 5710Z",
 435          .matches = {
 436                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 437                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 438                 },
 439         },
 440         {
 441          .callback = video_set_bqc_offset,
 442          .ident = "eMachines E510",
 443          .matches = {
 444                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 445                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 446                 },
 447         },
 448         {
 449          .callback = video_set_bqc_offset,
 450          .ident = "Acer Aspire 5315",
 451          .matches = {
 452                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 453                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 454                 },
 455         },
 456         {
 457          .callback = video_set_bqc_offset,
 458          .ident = "Acer Aspire 7720",
 459          .matches = {
 460                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 461                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 462                 },
 463         },
 464
 465         /*
 466          * Some machines have a broken acpi-video interface for brightness
 467          * control, but still need an acpi_video_device_lcd_set_level() call
 468          * on resume to turn the backlight power on.  We Enable backlight
 469          * control on these systems, but do not register a backlight sysfs
 470          * as brightness control does not work.
 471          */
 472         {
 473          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 474          .callback = video_disable_backlight_sysfs_if,
 475          .ident = "Toshiba Portege R700",
 476          .matches = {
 477                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 478                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 479                 },
 480         },
 481         {
 482          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 483          .callback = video_disable_backlight_sysfs_if,
 484          .ident = "Toshiba Portege R830",
 485          .matches = {
 486                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 487                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 488                 },
 489         },
 490         {
 491          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 492          .callback = video_disable_backlight_sysfs_if,
 493          .ident = "Toshiba Satellite R830",
 494          .matches = {
 495                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 496                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 497                 },
 498         },
 499         {
 500          .callback = video_disable_backlight_sysfs_if,
 501          .ident = "Toshiba Satellite Z830",
 502          .matches = {
 503                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 504                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE Z830"),
 505                 },
 506         },
 507         {
 508          .callback = video_disable_backlight_sysfs_if,
 509          .ident = "Toshiba Portege Z830",
 510          .matches = {
 511                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 512                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE Z830"),
 513                 },
 514         },
 515         /*
 516          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 517          * but the IDs actually follow the Device ID Scheme.
 518          */
 519         {
 520          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 521          .callback = video_set_device_id_scheme,
 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 have multiple video output devices, but only the one
 530          * that is the type of LCD can do the backlight control so we should not
 531          * register backlight interface for other video output devices.
 532          */
 533         {
 534          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 535          .callback = video_enable_only_lcd,
 536          .ident = "ESPRIMO Mobile M9410",
 537          .matches = {
 538                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 539                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 540                 },
 541         },
 542         /*
 543          * Some machines report wrong key events on the acpi-bus, suppress
 544          * key event reporting on these.  Note this is only intended to work
 545          * around events which are plain wrong. In some cases we get double
 546          * events, in this case acpi-video is considered the canonical source
 547          * and the events from the other source should be filtered. E.g.
 548          * by calling acpi_video_handles_brightness_key_presses() from the
 549          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 550          */
 551         {
 552          .callback = video_set_report_key_events,
 553          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 554          .ident = "Dell Vostro V131",
 555          .matches = {
 556                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 557                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 558                 },
 559         },
 560         {
 561          .callback = video_set_report_key_events,
 562          .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 563          .ident = "Dell Vostro 3350",
 564          .matches = {
 565                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 566                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3350"),
 567                 },
 568         },
 569         /*
 570          * Some machines change the brightness themselves when a brightness
 571          * hotkey gets pressed, despite us telling them not to. In this case
 572          * acpi_video_device_notify() should only call backlight_force_update(
 573          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 574          */
 575         {
 576          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 577          .callback = video_hw_changes_brightness,
 578          .ident = "Packard Bell EasyNote MZ35",
 579          .matches = {
 580                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 581                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 582                 },
 583         },
 584         {}
 585 };
 586
 587 static unsigned long long
 588 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 589                               unsigned long long bqc_value)
 590 {
 591         unsigned long long level;
 592
 593         if (device->brightness->flags._BQC_use_index) {
 594                 /*
 595                  * _BQC returns an index that doesn't account for the first 2
 596                  * items with special meaning (see enum acpi_video_level_idx),
 597                  * so we need to compensate for that by offsetting ourselves
 598                  */
 599                 if (device->brightness->flags._BCL_reversed)
 600                         bqc_value = device->brightness->count -
 601                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 602
 603                 level = device->brightness->levels[bqc_value +
 604                                                    ACPI_VIDEO_FIRST_LEVEL];
 605         } else {
 606                 level = bqc_value;
 607         }
 608
 609         level += bqc_offset_aml_bug_workaround;
 610
 611         return level;
 612 }
 613
 614 static int
 615 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 616                                         unsigned long long *level, bool raw)
 617 {
 618         acpi_status status = AE_OK;
 619         int i;
 620
 621         if (device->cap._BQC || device->cap._BCQ) {
 622                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 623
 624                 status = acpi_evaluate_integer(device->dev->handle, buf,
 625                                                 NULL, level);
 626                 if (ACPI_SUCCESS(status)) {
 627                         if (raw) {
 628                                 /*
 629                                  * Caller has indicated he wants the raw
 630                                  * value returned by _BQC, so don't furtherly
 631                                  * mess with the value.
 632                                  */
 633                                 return 0;
 634                         }
 635
 636                         *level = acpi_video_bqc_value_to_level(device, *level);
 637
 638                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 639                              i < device->brightness->count; i++)
 640                                 if (device->brightness->levels[i] == *level) {
 641                                         device->brightness->curr = *level;
 642                                         return 0;
 643                                 }
 644                         /*
 645                          * BQC returned an invalid level.
 646                          * Stop using it.
 647                          */
 648                         acpi_handle_info(device->dev->handle,
 649                                          "%s returned an invalid level", buf);
 650                         device->cap._BQC = device->cap._BCQ = 0;
 651                 } else {
 652                         /*
 653                          * Fixme:
 654                          * should we return an error or ignore this failure?
 655                          * dev->brightness->curr is a cached value which stores
 656                          * the correct current backlight level in most cases.
 657                          * ACPI video backlight still works w/ buggy _BQC.
 658                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 659                          */
 660                         acpi_handle_info(device->dev->handle,
 661                                          "%s evaluation failed", buf);
 662                         device->cap._BQC = device->cap._BCQ = 0;
 663                 }
 664         }
 665
 666         *level = device->brightness->curr;
 667         return 0;
 668 }
 669
 670 static int
 671 acpi_video_device_EDID(struct acpi_video_device *device,
 672                        union acpi_object **edid, ssize_t length)
 673 {
 674         int status;
 675         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 676         union acpi_object *obj;
 677         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 678         struct acpi_object_list args = { 1, &arg0 };
 679
 680
 681         *edid = NULL;
 682
 683         if (!device)
 684                 return -ENODEV;
 685         if (length == 128)
 686                 arg0.integer.value = 1;
 687         else if (length == 256)
 688                 arg0.integer.value = 2;
 689         else
 690                 return -EINVAL;
 691
 692         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 693         if (ACPI_FAILURE(status))
 694                 return -ENODEV;
 695
 696         obj = buffer.pointer;
 697
 698         if (obj && obj->type == ACPI_TYPE_BUFFER)
 699                 *edid = obj;
 700         else {
 701                 acpi_handle_info(device->dev->handle, "Invalid _DDC data\n");
 702                 status = -EFAULT;
 703                 kfree(obj);
 704         }
 705
 706         return status;
 707 }
 708
 709 /* bus */
 710
 711 /*
 712  *  Arg:
 713  *      video           : video bus device pointer
 714  *      bios_flag       :
 715  *              0.      The system BIOS should NOT automatically switch(toggle)
 716  *                      the active display output.
 717  *              1.      The system BIOS should automatically switch (toggle) the
 718  *                      active display output. No switch event.
 719  *              2.      The _DGS value should be locked.
 720  *              3.      The system BIOS should not automatically switch (toggle) the
 721  *                      active display output, but instead generate the display switch
 722  *                      event notify code.
 723  *      lcd_flag        :
 724  *              0.      The system BIOS should automatically control the brightness level
 725  *                      of the LCD when:
 726  *                      - the power changes from AC to DC (ACPI appendix B)
 727  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 728  *              1.      The system BIOS should NOT automatically control the brightness
 729  *                      level of the LCD when:
 730  *                      - the power changes from AC to DC (ACPI appendix B)
 731  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 732  *  Return Value:
 733  *              -EINVAL wrong arg.
 734  */
 735
 736 static int
 737 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 738 {
 739         acpi_status status;
 740
 741         if (!video->cap._DOS)
 742                 return 0;
 743
 744         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 745                 return -EINVAL;
 746         video->dos_setting = (lcd_flag << 2) | bios_flag;
 747         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 748                                             (lcd_flag << 2) | bios_flag);
 749         if (ACPI_FAILURE(status))
 750                 return -EIO;
 751
 752         return 0;
 753 }
 754
 755 /*
 756  * Simple comparison function used to sort backlight levels.
 757  */
 758
 759 static int
 760 acpi_video_cmp_level(const void *a, const void *b)
 761 {
 762         return *(int *)a - *(int *)b;
 763 }
 764
 765 /*
 766  * Decides if _BQC/_BCQ for this system is usable
 767  *
 768  * We do this by changing the level first and then read out the current
 769  * brightness level, if the value does not match, find out if it is using
 770  * index. If not, clear the _BQC/_BCQ capability.
 771  */
 772 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 773                                 int max_level, int current_level)
 774 {
 775         struct acpi_video_device_brightness *br = device->brightness;
 776         int result;
 777         unsigned long long level;
 778         int test_level;
 779
 780         /* don't mess with existing known broken systems */
 781         if (bqc_offset_aml_bug_workaround)
 782                 return 0;
 783
 784         /*
 785          * Some systems always report current brightness level as maximum
 786          * through _BQC, we need to test another value for them. However,
 787          * there is a subtlety:
 788          *
 789          * If the _BCL package ordering is descending, the first level
 790          * (br->levels[2]) is likely to be 0, and if the number of levels
 791          * matches the number of steps, we might confuse a returned level to
 792          * mean the index.
 793          *
 794          * For example:
 795          *
 796          *     current_level = max_level = 100
 797          *     test_level = 0
 798          *     returned level = 100
 799          *
 800          * In this case 100 means the level, not the index, and _BCM failed.
 801          * Still, if the _BCL package ordering is descending, the index of
 802          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 803          *
 804          * This causes all _BQC calls to return bogus values causing weird
 805          * behavior from the user's perspective.  For example:
 806          *
 807          * xbacklight -set 10; xbacklight -set 20;
 808          *
 809          * would flash to 90% and then slowly down to the desired level (20).
 810          *
 811          * The solution is simple; test anything other than the first level
 812          * (e.g. 1).
 813          */
 814         test_level = current_level == max_level
 815                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 816                 : max_level;
 817
 818         result = acpi_video_device_lcd_set_level(device, test_level);
 819         if (result)
 820                 return result;
 821
 822         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 823         if (result)
 824                 return result;
 825
 826         if (level != test_level) {
 827                 /* buggy _BQC found, need to find out if it uses index */
 828                 if (level < br->count) {
 829                         if (br->flags._BCL_reversed)
 830                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 831                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 832                                 br->flags._BQC_use_index = 1;
 833                 }
 834
 835                 if (!br->flags._BQC_use_index)
 836                         device->cap._BQC = device->cap._BCQ = 0;
 837         }
 838
 839         return 0;
 840 }
 841
 842 int acpi_video_get_levels(struct acpi_device *device,
 843                           struct acpi_video_device_brightness **dev_br,
 844                           int *pmax_level)
 845 {
 846         union acpi_object *obj = NULL;
 847         int i, max_level = 0, count = 0, level_ac_battery = 0;
 848         union acpi_object *o;
 849         struct acpi_video_device_brightness *br = NULL;
 850         int result = 0;
 851         u32 value;
 852
 853         if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
 854                 acpi_handle_debug(device->handle,
 855                                   "Could not query available LCD brightness level\n");
 856                 result = -ENODEV;
 857                 goto out;
 858         }
 859
 860         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 861                 result = -EINVAL;
 862                 goto out;
 863         }
 864
 865         br = kzalloc(sizeof(*br), GFP_KERNEL);
 866         if (!br) {
 867                 result = -ENOMEM;
 868                 goto out;
 869         }
 870
 871         /*
 872          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 873          * in order to account for buggy BIOS which don't export the first two
 874          * special levels (see below)
 875          */
 876         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 877                                    sizeof(*br->levels),
 878                                    GFP_KERNEL);
 879         if (!br->levels) {
 880                 result = -ENOMEM;
 881                 goto out_free;
 882         }
 883
 884         for (i = 0; i < obj->package.count; i++) {
 885                 o = (union acpi_object *)&obj->package.elements[i];
 886                 if (o->type != ACPI_TYPE_INTEGER) {
 887                         acpi_handle_info(device->handle, "Invalid data\n");
 888                         continue;
 889                 }
 890                 value = (u32) o->integer.value;
 891                 /* Skip duplicate entries */
 892                 if (count > ACPI_VIDEO_FIRST_LEVEL
 893                     && br->levels[count - 1] == value)
 894                         continue;
 895
 896                 br->levels[count] = value;
 897
 898                 if (br->levels[count] > max_level)
 899                         max_level = br->levels[count];
 900                 count++;
 901         }
 902
 903         /*
 904          * some buggy BIOS don't export the levels
 905          * when machine is on AC/Battery in _BCL package.
 906          * In this case, the first two elements in _BCL packages
 907          * are also supported brightness levels that OS should take care of.
 908          */
 909         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 910                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 911                         level_ac_battery++;
 912                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 913                         level_ac_battery++;
 914         }
 915
 916         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 917                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 918                 br->flags._BCL_no_ac_battery_levels = 1;
 919                 for (i = (count - 1 + level_ac_battery);
 920                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 921                         br->levels[i] = br->levels[i - level_ac_battery];
 922                 count += level_ac_battery;
 923         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 924                 acpi_handle_info(device->handle,
 925                                  "Too many duplicates in _BCL package");
 926
 927         /* Check if the _BCL package is in a reversed order */
 928         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 929                 br->flags._BCL_reversed = 1;
 930                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 931                      count - ACPI_VIDEO_FIRST_LEVEL,
 932                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 933                      acpi_video_cmp_level, NULL);
 934         } else if (max_level != br->levels[count - 1])
 935                 acpi_handle_info(device->handle,
 936                                  "Found unordered _BCL package");
 937
 938         br->count = count;
 939         *dev_br = br;
 940         if (pmax_level)
 941                 *pmax_level = max_level;
 942
 943 out:
 944         kfree(obj);
 945         return result;
 946 out_free:
 947         kfree(br);
 948         goto out;
 949 }
 950 EXPORT_SYMBOL(acpi_video_get_levels);
 951
 952 /*
 953  *  Arg:
 954  *      device  : video output device (LCD, CRT, ..)
 955  *
 956  *  Return Value:
 957  *      Maximum brightness level
 958  *
 959  *  Allocate and initialize device->brightness.
 960  */
 961
 962 static int
 963 acpi_video_init_brightness(struct acpi_video_device *device)
 964 {
 965         int i, max_level = 0;
 966         unsigned long long level, level_old;
 967         struct acpi_video_device_brightness *br = NULL;
 968         int result;
 969
 970         result = acpi_video_get_levels(device->dev, &br, &max_level);
 971         if (result)
 972                 return result;
 973         device->brightness = br;
 974
 975         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 976         br->curr = level = max_level;
 977
 978         if (!device->cap._BQC)
 979                 goto set_level;
 980
 981         result = acpi_video_device_lcd_get_level_current(device,
 982                                                          &level_old, true);
 983         if (result)
 984                 goto out_free_levels;
 985
 986         result = acpi_video_bqc_quirk(device, max_level, level_old);
 987         if (result)
 988                 goto out_free_levels;
 989         /*
 990          * cap._BQC may get cleared due to _BQC is found to be broken
 991          * in acpi_video_bqc_quirk, so check again here.
 992          */
 993         if (!device->cap._BQC)
 994                 goto set_level;
 995
 996         level = acpi_video_bqc_value_to_level(device, level_old);
 997         /*
 998          * On some buggy laptops, _BQC returns an uninitialized
 999          * value when invoked for the first time, i.e.
1000          * level_old is invalid (no matter whether it's a level
1001          * or an index). Set the backlight to max_level in this case.
1002          */
1003         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
1004                 if (level == br->levels[i])
1005                         break;
1006         if (i == br->count || !level)
1007                 level = max_level;
1008
1009 set_level:
1010         result = acpi_video_device_lcd_set_level(device, level);
1011         if (result)
1012                 goto out_free_levels;
1013
1014         acpi_handle_debug(device->dev->handle, "found %d brightness levels\n",
1015                           br->count - ACPI_VIDEO_FIRST_LEVEL);
1016
1017         return 0;
1018
1019 out_free_levels:
1020         kfree(br->levels);
1021         kfree(br);
1022         device->brightness = NULL;
1023         return result;
1024 }
1025
1026 /*
1027  *  Arg:
1028  *      device  : video output device (LCD, CRT, ..)
1029  *
1030  *  Return Value:
1031  *      None
1032  *
1033  *  Find out all required AML methods defined under the output
1034  *  device.
1035  */
1036
1037 static void acpi_video_device_find_cap(struct acpi_video_device *device)
1038 {
1039         if (acpi_has_method(device->dev->handle, "_ADR"))
1040                 device->cap._ADR = 1;
1041         if (acpi_has_method(device->dev->handle, "_BCL"))
1042                 device->cap._BCL = 1;
1043         if (acpi_has_method(device->dev->handle, "_BCM"))
1044                 device->cap._BCM = 1;
1045         if (acpi_has_method(device->dev->handle, "_BQC")) {
1046                 device->cap._BQC = 1;
1047         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1048                 acpi_handle_info(device->dev->handle,
1049                                  "_BCQ is used instead of _BQC\n");
1050                 device->cap._BCQ = 1;
1051         }
1052
1053         if (acpi_has_method(device->dev->handle, "_DDC"))
1054                 device->cap._DDC = 1;
1055 }
1056
1057 /*
1058  *  Arg:
1059  *      device  : video output device (VGA)
1060  *
1061  *  Return Value:
1062  *      None
1063  *
1064  *  Find out all required AML methods defined under the video bus device.
1065  */
1066
1067 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1068 {
1069         if (acpi_has_method(video->device->handle, "_DOS"))
1070                 video->cap._DOS = 1;
1071         if (acpi_has_method(video->device->handle, "_DOD"))
1072                 video->cap._DOD = 1;
1073         if (acpi_has_method(video->device->handle, "_ROM"))
1074                 video->cap._ROM = 1;
1075         if (acpi_has_method(video->device->handle, "_GPD"))
1076                 video->cap._GPD = 1;
1077         if (acpi_has_method(video->device->handle, "_SPD"))
1078                 video->cap._SPD = 1;
1079         if (acpi_has_method(video->device->handle, "_VPO"))
1080                 video->cap._VPO = 1;
1081 }
1082
1083 /*
1084  * Check whether the video bus device has required AML method to
1085  * support the desired features
1086  */
1087
1088 static int acpi_video_bus_check(struct acpi_video_bus *video)
1089 {
1090         acpi_status status = -ENOENT;
1091         struct pci_dev *dev;
1092
1093         if (!video)
1094                 return -EINVAL;
1095
1096         dev = acpi_get_pci_dev(video->device->handle);
1097         if (!dev)
1098                 return -ENODEV;
1099         pci_dev_put(dev);
1100
1101         /*
1102          * Since there is no HID, CID and so on for VGA driver, we have
1103          * to check well known required nodes.
1104          */
1105
1106         /* Does this device support video switching? */
1107         if (video->cap._DOS || video->cap._DOD) {
1108                 if (!video->cap._DOS) {
1109                         pr_info(FW_BUG "ACPI(%s) defines _DOD but not _DOS\n",
1110                                 acpi_device_bid(video->device));
1111                 }
1112                 video->flags.multihead = 1;
1113                 status = 0;
1114         }
1115
1116         /* Does this device support retrieving a video ROM? */
1117         if (video->cap._ROM) {
1118                 video->flags.rom = 1;
1119                 status = 0;
1120         }
1121
1122         /* Does this device support configuring which video device to POST? */
1123         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1124                 video->flags.post = 1;
1125                 status = 0;
1126         }
1127
1128         return status;
1129 }
1130
1131 /*
1132  * --------------------------------------------------------------------------
1133  *                               Driver Interface
1134  * --------------------------------------------------------------------------
1135  */
1136
1137 /* device interface */
1138 static struct acpi_video_device_attrib *
1139 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1140 {
1141         struct acpi_video_enumerated_device *ids;
1142         int i;
1143
1144         for (i = 0; i < video->attached_count; i++) {
1145                 ids = &video->attached_array[i];
1146                 if ((ids->value.int_val & 0xffff) == device_id)
1147                         return &ids->value.attrib;
1148         }
1149
1150         return NULL;
1151 }
1152
1153 static int
1154 acpi_video_get_device_type(struct acpi_video_bus *video,
1155                            unsigned long device_id)
1156 {
1157         struct acpi_video_enumerated_device *ids;
1158         int i;
1159
1160         for (i = 0; i < video->attached_count; i++) {
1161                 ids = &video->attached_array[i];
1162                 if ((ids->value.int_val & 0xffff) == device_id)
1163                         return ids->value.int_val;
1164         }
1165
1166         return 0;
1167 }
1168
1169 static int acpi_video_bus_get_one_device(struct acpi_device *device, void *arg)
1170 {
1171         struct acpi_video_bus *video = arg;
1172         struct acpi_video_device_attrib *attribute;
1173         struct acpi_video_device *data;
1174         unsigned long long device_id;
1175         acpi_status status;
1176         int device_type;
1177
1178         status = acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1179         /* Skip devices without _ADR instead of failing. */
1180         if (ACPI_FAILURE(status))
1181                 goto exit;
1182
1183         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1184         if (!data) {
1185                 dev_dbg(&device->dev, "Cannot attach\n");
1186                 return -ENOMEM;
1187         }
1188
1189         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1190         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1191         device->driver_data = data;
1192
1193         data->device_id = device_id;
1194         data->video = video;
1195         data->dev = device;
1196         INIT_DELAYED_WORK(&data->switch_brightness_work,
1197                           acpi_video_switch_brightness);
1198
1199         attribute = acpi_video_get_device_attr(video, device_id);
1200
1201         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1202                 switch (attribute->display_type) {
1203                 case ACPI_VIDEO_DISPLAY_CRT:
1204                         data->flags.crt = 1;
1205                         break;
1206                 case ACPI_VIDEO_DISPLAY_TV:
1207                         data->flags.tvout = 1;
1208                         break;
1209                 case ACPI_VIDEO_DISPLAY_DVI:
1210                         data->flags.dvi = 1;
1211                         break;
1212                 case ACPI_VIDEO_DISPLAY_LCD:
1213                         data->flags.lcd = 1;
1214                         break;
1215                 default:
1216                         data->flags.unknown = 1;
1217                         break;
1218                 }
1219                 if (attribute->bios_can_detect)
1220                         data->flags.bios = 1;
1221         } else {
1222                 /* Check for legacy IDs */
1223                 device_type = acpi_video_get_device_type(video, device_id);
1224                 /* Ignore bits 16 and 18-20 */
1225                 switch (device_type & 0xffe2ffff) {
1226                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1227                         data->flags.crt = 1;
1228                         break;
1229                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1230                         data->flags.lcd = 1;
1231                         break;
1232                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1233                         data->flags.tvout = 1;
1234                         break;
1235                 default:
1236                         data->flags.unknown = 1;
1237                 }
1238         }
1239
1240         acpi_video_device_bind(video, data);
1241         acpi_video_device_find_cap(data);
1242
1243         if (data->cap._BCM && data->cap._BCL)
1244                 may_report_brightness_keys = true;
1245
1246         mutex_lock(&video->device_list_lock);
1247         list_add_tail(&data->entry, &video->video_device_list);
1248         mutex_unlock(&video->device_list_lock);
1249
1250 exit:
1251         video->child_count++;
1252         return 0;
1253 }
1254
1255 /*
1256  *  Arg:
1257  *      video   : video bus device
1258  *
1259  *  Return:
1260  *      none
1261  *
1262  *  Enumerate the video device list of the video bus,
1263  *  bind the ids with the corresponding video devices
1264  *  under the video bus.
1265  */
1266
1267 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1268 {
1269         struct acpi_video_device *dev;
1270
1271         mutex_lock(&video->device_list_lock);
1272
1273         list_for_each_entry(dev, &video->video_device_list, entry)
1274                 acpi_video_device_bind(video, dev);
1275
1276         mutex_unlock(&video->device_list_lock);
1277 }
1278
1279 /*
1280  *  Arg:
1281  *      video   : video bus device
1282  *      device  : video output device under the video
1283  *              bus
1284  *
1285  *  Return:
1286  *      none
1287  *
1288  *  Bind the ids with the corresponding video devices
1289  *  under the video bus.
1290  */
1291
1292 static void
1293 acpi_video_device_bind(struct acpi_video_bus *video,
1294                        struct acpi_video_device *device)
1295 {
1296         struct acpi_video_enumerated_device *ids;
1297         int i;
1298
1299         for (i = 0; i < video->attached_count; i++) {
1300                 ids = &video->attached_array[i];
1301                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1302                         ids->bind_info = device;
1303                         acpi_handle_debug(video->device->handle, "%s: %d\n",
1304                                           __func__, i);
1305                 }
1306         }
1307 }
1308
1309 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1310 {
1311         struct acpi_video_bus *video = device->video;
1312         int i;
1313
1314         /*
1315          * If we have a broken _DOD or we have more than 8 output devices
1316          * under the graphics controller node that we can't proper deal with
1317          * in the operation region code currently, no need to test.
1318          */
1319         if (!video->attached_count || video->child_count > 8)
1320                 return true;
1321
1322         for (i = 0; i < video->attached_count; i++) {
1323                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1324                     (device->device_id & 0xfff))
1325                         return true;
1326         }
1327
1328         return false;
1329 }
1330
1331 /*
1332  *  Arg:
1333  *      video   : video bus device
1334  *
1335  *  Return:
1336  *      < 0     : error
1337  *
1338  *  Call _DOD to enumerate all devices attached to display adapter
1339  *
1340  */
1341
1342 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1343 {
1344         int status;
1345         int count;
1346         int i;
1347         struct acpi_video_enumerated_device *active_list;
1348         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1349         union acpi_object *dod = NULL;
1350         union acpi_object *obj;
1351
1352         if (!video->cap._DOD)
1353                 return AE_NOT_EXIST;
1354
1355         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1356         if (ACPI_FAILURE(status)) {
1357                 acpi_handle_info(video->device->handle,
1358                                  "_DOD evaluation failed: %s\n",
1359                                  acpi_format_exception(status));
1360                 return status;
1361         }
1362
1363         dod = buffer.pointer;
1364         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1365                 acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1366                 status = -EFAULT;
1367                 goto out;
1368         }
1369
1370         acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1371                           dod->package.count);
1372
1373         active_list = kcalloc(1 + dod->package.count,
1374                               sizeof(struct acpi_video_enumerated_device),
1375                               GFP_KERNEL);
1376         if (!active_list) {
1377                 status = -ENOMEM;
1378                 goto out;
1379         }
1380
1381         count = 0;
1382         for (i = 0; i < dod->package.count; i++) {
1383                 obj = &dod->package.elements[i];
1384
1385                 if (obj->type != ACPI_TYPE_INTEGER) {
1386                         acpi_handle_info(video->device->handle,
1387                                          "Invalid _DOD data in element %d\n", i);
1388                         continue;
1389                 }
1390
1391                 active_list[count].value.int_val = obj->integer.value;
1392                 active_list[count].bind_info = NULL;
1393
1394                 acpi_handle_debug(video->device->handle,
1395                                   "_DOD element[%d] = %d\n", i,
1396                                   (int)obj->integer.value);
1397
1398                 count++;
1399         }
1400
1401         kfree(video->attached_array);
1402
1403         video->attached_array = active_list;
1404         video->attached_count = count;
1405
1406 out:
1407         kfree(buffer.pointer);
1408         return status;
1409 }
1410
1411 static int
1412 acpi_video_get_next_level(struct acpi_video_device *device,
1413                           u32 level_current, u32 event)
1414 {
1415         int min, max, min_above, max_below, i, l, delta = 255;
1416         max = max_below = 0;
1417         min = min_above = 255;
1418         /* Find closest level to level_current */
1419         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1420                 l = device->brightness->levels[i];
1421                 if (abs(l - level_current) < abs(delta)) {
1422                         delta = l - level_current;
1423                         if (!delta)
1424                                 break;
1425                 }
1426         }
1427         /* Adjust level_current to closest available level */
1428         level_current += delta;
1429         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1430                 l = device->brightness->levels[i];
1431                 if (l < min)
1432                         min = l;
1433                 if (l > max)
1434                         max = l;
1435                 if (l < min_above && l > level_current)
1436                         min_above = l;
1437                 if (l > max_below && l < level_current)
1438                         max_below = l;
1439         }
1440
1441         switch (event) {
1442         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1443                 return (level_current < max) ? min_above : min;
1444         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1445                 return (level_current < max) ? min_above : max;
1446         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1447                 return (level_current > min) ? max_below : min;
1448         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1449         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1450                 return 0;
1451         default:
1452                 return level_current;
1453         }
1454 }
1455
1456 static void
1457 acpi_video_switch_brightness(struct work_struct *work)
1458 {
1459         struct acpi_video_device *device = container_of(to_delayed_work(work),
1460                              struct acpi_video_device, switch_brightness_work);
1461         unsigned long long level_current, level_next;
1462         int event = device->switch_brightness_event;
1463         int result = -EINVAL;
1464
1465         /* no warning message if acpi_backlight=vendor or a quirk is used */
1466         if (!device->backlight)
1467                 return;
1468
1469         if (!device->brightness)
1470                 goto out;
1471
1472         result = acpi_video_device_lcd_get_level_current(device,
1473                                                          &level_current,
1474                                                          false);
1475         if (result)
1476                 goto out;
1477
1478         level_next = acpi_video_get_next_level(device, level_current, event);
1479
1480         result = acpi_video_device_lcd_set_level(device, level_next);
1481
1482         if (!result)
1483                 backlight_force_update(device->backlight,
1484                                        BACKLIGHT_UPDATE_HOTKEY);
1485
1486 out:
1487         if (result)
1488                 acpi_handle_info(device->dev->handle,
1489                                  "Failed to switch brightness\n");
1490 }
1491
1492 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1493                         void **edid)
1494 {
1495         struct acpi_video_bus *video;
1496         struct acpi_video_device *video_device;
1497         union acpi_object *buffer = NULL;
1498         acpi_status status;
1499         int i, length;
1500
1501         if (!device || !acpi_driver_data(device))
1502                 return -EINVAL;
1503
1504         video = acpi_driver_data(device);
1505
1506         for (i = 0; i < video->attached_count; i++) {
1507                 video_device = video->attached_array[i].bind_info;
1508                 length = 256;
1509
1510                 if (!video_device)
1511                         continue;
1512
1513                 if (!video_device->cap._DDC)
1514                         continue;
1515
1516                 if (type) {
1517                         switch (type) {
1518                         case ACPI_VIDEO_DISPLAY_CRT:
1519                                 if (!video_device->flags.crt)
1520                                         continue;
1521                                 break;
1522                         case ACPI_VIDEO_DISPLAY_TV:
1523                                 if (!video_device->flags.tvout)
1524                                         continue;
1525                                 break;
1526                         case ACPI_VIDEO_DISPLAY_DVI:
1527                                 if (!video_device->flags.dvi)
1528                                         continue;
1529                                 break;
1530                         case ACPI_VIDEO_DISPLAY_LCD:
1531                                 if (!video_device->flags.lcd)
1532                                         continue;
1533                                 break;
1534                         }
1535                 } else if (video_device->device_id != device_id) {
1536                         continue;
1537                 }
1538
1539                 status = acpi_video_device_EDID(video_device, &buffer, length);
1540
1541                 if (ACPI_FAILURE(status) || !buffer ||
1542                     buffer->type != ACPI_TYPE_BUFFER) {
1543                         length = 128;
1544                         status = acpi_video_device_EDID(video_device, &buffer,
1545                                                         length);
1546                         if (ACPI_FAILURE(status) || !buffer ||
1547                             buffer->type != ACPI_TYPE_BUFFER) {
1548                                 continue;
1549                         }
1550                 }
1551
1552                 *edid = buffer->buffer.pointer;
1553                 return length;
1554         }
1555
1556         return -ENODEV;
1557 }
1558 EXPORT_SYMBOL(acpi_video_get_edid);
1559
1560 static int
1561 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1562                            struct acpi_device *device)
1563 {
1564         /*
1565          * There are systems where video module known to work fine regardless
1566          * of broken _DOD and ignoring returned value here doesn't cause
1567          * any issues later.
1568          */
1569         acpi_video_device_enumerate(video);
1570
1571         return acpi_dev_for_each_child(device, acpi_video_bus_get_one_device, video);
1572 }
1573
1574 /* acpi_video interface */
1575
1576 /*
1577  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1578  * perform any automatic brightness change on receiving a notification.
1579  */
1580 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1581 {
1582         return acpi_video_bus_DOS(video, 0,
1583                                   acpi_osi_is_win8() ? 1 : 0);
1584 }
1585
1586 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1587 {
1588         return acpi_video_bus_DOS(video, 0,
1589                                   acpi_osi_is_win8() ? 0 : 1);
1590 }
1591
1592 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1593 {
1594         struct acpi_video_bus *video = acpi_driver_data(device);
1595         struct input_dev *input;
1596         int keycode = 0;
1597
1598         if (!video || !video->input)
1599                 return;
1600
1601         input = video->input;
1602
1603         switch (event) {
1604         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1605                                          * most likely via hotkey. */
1606                 keycode = KEY_SWITCHVIDEOMODE;
1607                 break;
1608
1609         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1610                                          * connector. */
1611                 acpi_video_device_enumerate(video);
1612                 acpi_video_device_rebind(video);
1613                 keycode = KEY_SWITCHVIDEOMODE;
1614                 break;
1615
1616         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1617                 keycode = KEY_SWITCHVIDEOMODE;
1618                 break;
1619         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1620                 keycode = KEY_VIDEO_NEXT;
1621                 break;
1622         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1623                 keycode = KEY_VIDEO_PREV;
1624                 break;
1625
1626         default:
1627                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1628                                   event);
1629                 break;
1630         }
1631
1632         if (acpi_notifier_call_chain(device, event, 0))
1633                 /* Something vetoed the keypress. */
1634                 keycode = 0;
1635
1636         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1637                 input_report_key(input, keycode, 1);
1638                 input_sync(input);
1639                 input_report_key(input, keycode, 0);
1640                 input_sync(input);
1641         }
1642 }
1643
1644 static void brightness_switch_event(struct acpi_video_device *video_device,
1645                                     u32 event)
1646 {
1647         if (!brightness_switch_enabled)
1648                 return;
1649
1650         video_device->switch_brightness_event = event;
1651         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1652 }
1653
1654 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1655 {
1656         struct acpi_video_device *video_device = data;
1657         struct acpi_device *device = NULL;
1658         struct acpi_video_bus *bus;
1659         struct input_dev *input;
1660         int keycode = 0;
1661
1662         if (!video_device)
1663                 return;
1664
1665         device = video_device->dev;
1666         bus = video_device->video;
1667         input = bus->input;
1668
1669         if (hw_changes_brightness > 0) {
1670                 if (video_device->backlight)
1671                         backlight_force_update(video_device->backlight,
1672                                                BACKLIGHT_UPDATE_HOTKEY);
1673                 acpi_notifier_call_chain(device, event, 0);
1674                 return;
1675         }
1676
1677         switch (event) {
1678         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1679                 brightness_switch_event(video_device, event);
1680                 keycode = KEY_BRIGHTNESS_CYCLE;
1681                 break;
1682         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1683                 brightness_switch_event(video_device, event);
1684                 keycode = KEY_BRIGHTNESSUP;
1685                 break;
1686         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1687                 brightness_switch_event(video_device, event);
1688                 keycode = KEY_BRIGHTNESSDOWN;
1689                 break;
1690         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1691                 brightness_switch_event(video_device, event);
1692                 keycode = KEY_BRIGHTNESS_ZERO;
1693                 break;
1694         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1695                 brightness_switch_event(video_device, event);
1696                 keycode = KEY_DISPLAY_OFF;
1697                 break;
1698         default:
1699                 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1700                 break;
1701         }
1702
1703         if (keycode)
1704                 may_report_brightness_keys = true;
1705
1706         acpi_notifier_call_chain(device, event, 0);
1707
1708         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1709                 input_report_key(input, keycode, 1);
1710                 input_sync(input);
1711                 input_report_key(input, keycode, 0);
1712                 input_sync(input);
1713         }
1714 }
1715
1716 static int acpi_video_resume(struct notifier_block *nb,
1717                                 unsigned long val, void *ign)
1718 {
1719         struct acpi_video_bus *video;
1720         struct acpi_video_device *video_device;
1721         int i;
1722
1723         switch (val) {
1724         case PM_POST_HIBERNATION:
1725         case PM_POST_SUSPEND:
1726         case PM_POST_RESTORE:
1727                 video = container_of(nb, struct acpi_video_bus, pm_nb);
1728
1729                 dev_info(&video->device->dev, "Restoring backlight state\n");
1730
1731                 for (i = 0; i < video->attached_count; i++) {
1732                         video_device = video->attached_array[i].bind_info;
1733                         if (video_device && video_device->brightness)
1734                                 acpi_video_device_lcd_set_level(video_device,
1735                                                 video_device->brightness->curr);
1736                 }
1737
1738                 return NOTIFY_OK;
1739         }
1740         return NOTIFY_DONE;
1741 }
1742
1743 static acpi_status
1744 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1745                         void **return_value)
1746 {
1747         struct acpi_device *device = context;
1748         struct acpi_device *sibling;
1749
1750         if (handle == device->handle)
1751                 return AE_CTRL_TERMINATE;
1752
1753         sibling = acpi_fetch_acpi_dev(handle);
1754         if (!sibling)
1755                 return AE_OK;
1756
1757         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1758                         return AE_ALREADY_EXISTS;
1759
1760         return AE_OK;
1761 }
1762
1763 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1764 {
1765         struct backlight_properties props;
1766         struct pci_dev *pdev;
1767         acpi_handle acpi_parent;
1768         struct device *parent = NULL;
1769         int result;
1770         static int count;
1771         char *name;
1772
1773         result = acpi_video_init_brightness(device);
1774         if (result)
1775                 return;
1776
1777         if (disable_backlight_sysfs_if > 0)
1778                 return;
1779
1780         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1781         if (!name)
1782                 return;
1783         count++;
1784
1785         acpi_get_parent(device->dev->handle, &acpi_parent);
1786
1787         pdev = acpi_get_pci_dev(acpi_parent);
1788         if (pdev) {
1789                 parent = &pdev->dev;
1790                 pci_dev_put(pdev);
1791         }
1792
1793         memset(&props, 0, sizeof(struct backlight_properties));
1794         props.type = BACKLIGHT_FIRMWARE;
1795         props.max_brightness =
1796                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1797         device->backlight = backlight_device_register(name,
1798                                                       parent,
1799                                                       device,
1800                                                       &acpi_backlight_ops,
1801                                                       &props);
1802         kfree(name);
1803         if (IS_ERR(device->backlight)) {
1804                 device->backlight = NULL;
1805                 return;
1806         }
1807
1808         /*
1809          * Save current brightness level in case we have to restore it
1810          * before acpi_video_device_lcd_set_level() is called next time.
1811          */
1812         device->backlight->props.brightness =
1813                         acpi_video_get_brightness(device->backlight);
1814
1815         device->cooling_dev = thermal_cooling_device_register("LCD",
1816                                 device->dev, &video_cooling_ops);
1817         if (IS_ERR(device->cooling_dev)) {
1818                 /*
1819                  * Set cooling_dev to NULL so we don't crash trying to free it.
1820                  * Also, why the hell we are returning early and not attempt to
1821                  * register video output if cooling device registration failed?
1822                  * -- dtor
1823                  */
1824                 device->cooling_dev = NULL;
1825                 return;
1826         }
1827
1828         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1829                  device->cooling_dev->id);
1830         result = sysfs_create_link(&device->dev->dev.kobj,
1831                         &device->cooling_dev->device.kobj,
1832                         "thermal_cooling");
1833         if (result)
1834                 pr_info("sysfs link creation failed\n");
1835
1836         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1837                         &device->dev->dev.kobj, "device");
1838         if (result)
1839                 pr_info("Reverse sysfs link creation failed\n");
1840 }
1841
1842 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1843 {
1844         struct acpi_video_device *dev;
1845         union acpi_object *levels;
1846
1847         mutex_lock(&video->device_list_lock);
1848         list_for_each_entry(dev, &video->video_device_list, entry) {
1849                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1850                         kfree(levels);
1851         }
1852         mutex_unlock(&video->device_list_lock);
1853 }
1854
1855 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1856 {
1857         /*
1858          * Do not create backlight device for video output
1859          * device that is not in the enumerated list.
1860          */
1861         if (!acpi_video_device_in_dod(dev)) {
1862                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1863                 return false;
1864         }
1865
1866         if (only_lcd)
1867                 return dev->flags.lcd;
1868         return true;
1869 }
1870
1871 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1872 {
1873         struct acpi_video_device *dev;
1874
1875         if (video->backlight_registered)
1876                 return 0;
1877
1878         acpi_video_run_bcl_for_osi(video);
1879
1880         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1881                 return 0;
1882
1883         mutex_lock(&video->device_list_lock);
1884         list_for_each_entry(dev, &video->video_device_list, entry) {
1885                 if (acpi_video_should_register_backlight(dev))
1886                         acpi_video_dev_register_backlight(dev);
1887         }
1888         mutex_unlock(&video->device_list_lock);
1889
1890         video->backlight_registered = true;
1891
1892         video->pm_nb.notifier_call = acpi_video_resume;
1893         video->pm_nb.priority = 0;
1894         return register_pm_notifier(&video->pm_nb);
1895 }
1896
1897 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1898 {
1899         if (device->backlight) {
1900                 backlight_device_unregister(device->backlight);
1901                 device->backlight = NULL;
1902         }
1903         if (device->brightness) {
1904                 kfree(device->brightness->levels);
1905                 kfree(device->brightness);
1906                 device->brightness = NULL;
1907         }
1908         if (device->cooling_dev) {
1909                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1910                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1911                 thermal_cooling_device_unregister(device->cooling_dev);
1912                 device->cooling_dev = NULL;
1913         }
1914 }
1915
1916 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1917 {
1918         struct acpi_video_device *dev;
1919         int error;
1920
1921         if (!video->backlight_registered)
1922                 return 0;
1923
1924         error = unregister_pm_notifier(&video->pm_nb);
1925
1926         mutex_lock(&video->device_list_lock);
1927         list_for_each_entry(dev, &video->video_device_list, entry)
1928                 acpi_video_dev_unregister_backlight(dev);
1929         mutex_unlock(&video->device_list_lock);
1930
1931         video->backlight_registered = false;
1932
1933         return error;
1934 }
1935
1936 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1937 {
1938         acpi_status status;
1939         struct acpi_device *adev = device->dev;
1940
1941         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1942                                              acpi_video_device_notify, device);
1943         if (ACPI_FAILURE(status))
1944                 dev_err(&adev->dev, "Error installing notify handler\n");
1945         else
1946                 device->flags.notify = 1;
1947 }
1948
1949 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1950 {
1951         struct input_dev *input;
1952         struct acpi_video_device *dev;
1953         int error;
1954
1955         video->input = input = input_allocate_device();
1956         if (!input) {
1957                 error = -ENOMEM;
1958                 goto out;
1959         }
1960
1961         error = acpi_video_bus_start_devices(video);
1962         if (error)
1963                 goto err_free_input;
1964
1965         snprintf(video->phys, sizeof(video->phys),
1966                         "%s/video/input0", acpi_device_hid(video->device));
1967
1968         input->name = acpi_device_name(video->device);
1969         input->phys = video->phys;
1970         input->id.bustype = BUS_HOST;
1971         input->id.product = 0x06;
1972         input->dev.parent = &video->device->dev;
1973         input->evbit[0] = BIT(EV_KEY);
1974         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1975         set_bit(KEY_VIDEO_NEXT, input->keybit);
1976         set_bit(KEY_VIDEO_PREV, input->keybit);
1977         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1978         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1979         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1980         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1981         set_bit(KEY_DISPLAY_OFF, input->keybit);
1982
1983         error = input_register_device(input);
1984         if (error)
1985                 goto err_stop_dev;
1986
1987         mutex_lock(&video->device_list_lock);
1988         list_for_each_entry(dev, &video->video_device_list, entry)
1989                 acpi_video_dev_add_notify_handler(dev);
1990         mutex_unlock(&video->device_list_lock);
1991
1992         return 0;
1993
1994 err_stop_dev:
1995         acpi_video_bus_stop_devices(video);
1996 err_free_input:
1997         input_free_device(input);
1998         video->input = NULL;
1999 out:
2000         return error;
2001 }
2002
2003 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
2004 {
2005         if (dev->flags.notify) {
2006                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
2007                                            acpi_video_device_notify);
2008                 dev->flags.notify = 0;
2009         }
2010 }
2011
2012 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
2013 {
2014         struct acpi_video_device *dev;
2015
2016         mutex_lock(&video->device_list_lock);
2017         list_for_each_entry(dev, &video->video_device_list, entry)
2018                 acpi_video_dev_remove_notify_handler(dev);
2019         mutex_unlock(&video->device_list_lock);
2020
2021         acpi_video_bus_stop_devices(video);
2022         input_unregister_device(video->input);
2023         video->input = NULL;
2024 }
2025
2026 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
2027 {
2028         struct acpi_video_device *dev, *next;
2029
2030         mutex_lock(&video->device_list_lock);
2031         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
2032                 list_del(&dev->entry);
2033                 kfree(dev);
2034         }
2035         mutex_unlock(&video->device_list_lock);
2036
2037         return 0;
2038 }
2039
2040 static int instance;
2041
2042 static int acpi_video_bus_add(struct acpi_device *device)
2043 {
2044         struct acpi_video_bus *video;
2045         int error;
2046         acpi_status status;
2047
2048         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2049                                 acpi_dev_parent(device)->handle, 1,
2050                                 acpi_video_bus_match, NULL,
2051                                 device, NULL);
2052         if (status == AE_ALREADY_EXISTS) {
2053                 pr_info(FW_BUG
2054                         "Duplicate ACPI video bus devices for the"
2055                         " same VGA controller, please try module "
2056                         "parameter \"video.allow_duplicates=1\""
2057                         "if the current driver doesn't work.\n");
2058                 if (!allow_duplicates)
2059                         return -ENODEV;
2060         }
2061
2062         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2063         if (!video)
2064                 return -ENOMEM;
2065
2066         /* a hack to fix the duplicate name "VID" problem on T61 */
2067         if (!strcmp(device->pnp.bus_id, "VID")) {
2068                 if (instance)
2069                         device->pnp.bus_id[3] = '0' + instance;
2070                 instance++;
2071         }
2072         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2073         if (!strcmp(device->pnp.bus_id, "VGA")) {
2074                 if (instance)
2075                         device->pnp.bus_id[3] = '0' + instance;
2076                 instance++;
2077         }
2078
2079         video->device = device;
2080         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2081         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2082         device->driver_data = video;
2083
2084         acpi_video_bus_find_cap(video);
2085         error = acpi_video_bus_check(video);
2086         if (error)
2087                 goto err_free_video;
2088
2089         mutex_init(&video->device_list_lock);
2090         INIT_LIST_HEAD(&video->video_device_list);
2091
2092         error = acpi_video_bus_get_devices(video, device);
2093         if (error)
2094                 goto err_put_video;
2095
2096         pr_info("%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2097                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2098                video->flags.multihead ? "yes" : "no",
2099                video->flags.rom ? "yes" : "no",
2100                video->flags.post ? "yes" : "no");
2101         mutex_lock(&video_list_lock);
2102         list_add_tail(&video->entry, &video_bus_head);
2103         mutex_unlock(&video_list_lock);
2104
2105         acpi_video_bus_register_backlight(video);
2106         acpi_video_bus_add_notify_handler(video);
2107
2108         return 0;
2109
2110 err_put_video:
2111         acpi_video_bus_put_devices(video);
2112         kfree(video->attached_array);
2113 err_free_video:
2114         kfree(video);
2115         device->driver_data = NULL;
2116
2117         return error;
2118 }
2119
2120 static int acpi_video_bus_remove(struct acpi_device *device)
2121 {
2122         struct acpi_video_bus *video = NULL;
2123
2124
2125         if (!device || !acpi_driver_data(device))
2126                 return -EINVAL;
2127
2128         video = acpi_driver_data(device);
2129
2130         acpi_video_bus_remove_notify_handler(video);
2131         acpi_video_bus_unregister_backlight(video);
2132         acpi_video_bus_put_devices(video);
2133
2134         mutex_lock(&video_list_lock);
2135         list_del(&video->entry);
2136         mutex_unlock(&video_list_lock);
2137
2138         kfree(video->attached_array);
2139         kfree(video);
2140
2141         return 0;
2142 }
2143
2144 static int __init is_i740(struct pci_dev *dev)
2145 {
2146         if (dev->device == 0x00D1)
2147                 return 1;
2148         if (dev->device == 0x7000)
2149                 return 1;
2150         return 0;
2151 }
2152
2153 static int __init intel_opregion_present(void)
2154 {
2155         int opregion = 0;
2156         struct pci_dev *dev = NULL;
2157         u32 address;
2158
2159         for_each_pci_dev(dev) {
2160                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2161                         continue;
2162                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2163                         continue;
2164                 /* We don't want to poke around undefined i740 registers */
2165                 if (is_i740(dev))
2166                         continue;
2167                 pci_read_config_dword(dev, 0xfc, &address);
2168                 if (!address)
2169                         continue;
2170                 opregion = 1;
2171         }
2172         return opregion;
2173 }
2174
2175 /* Check if the chassis-type indicates there is no builtin LCD panel */
2176 static bool dmi_is_desktop(void)
2177 {
2178         const char *chassis_type;
2179         unsigned long type;
2180
2181         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2182         if (!chassis_type)
2183                 return false;
2184
2185         if (kstrtoul(chassis_type, 10, &type) != 0)
2186                 return false;
2187
2188         switch (type) {
2189         case 0x03: /* Desktop */
2190         case 0x04: /* Low Profile Desktop */
2191         case 0x05: /* Pizza Box */
2192         case 0x06: /* Mini Tower */
2193         case 0x07: /* Tower */
2194         case 0x10: /* Lunch Box */
2195         case 0x11: /* Main Server Chassis */
2196                 return true;
2197         }
2198
2199         return false;
2200 }
2201
2202 /*
2203  * We're seeing a lot of bogus backlight interfaces on newer machines
2204  * without a LCD such as desktops, servers and HDMI sticks. Checking the
2205  * lcd flag fixes this, enable this by default on any machines which are:
2206  * 1.  Win8 ready (where we also prefer the native backlight driver, so
2207  *     normally the acpi_video code should not register there anyways); *and*
2208  * 2.1 Report a desktop/server DMI chassis-type, or
2209  * 2.2 Are an ACPI-reduced-hardware platform (and thus won't use the EC for
2210        backlight control)
2211  */
2212 static bool should_check_lcd_flag(void)
2213 {
2214         if (!acpi_osi_is_win8())
2215                 return false;
2216
2217         if (dmi_is_desktop())
2218                 return true;
2219
2220         if (acpi_reduced_hardware())
2221                 return true;
2222
2223         return false;
2224 }
2225
2226 int acpi_video_register(void)
2227 {
2228         int ret = 0;
2229
2230         mutex_lock(&register_count_mutex);
2231         if (register_count) {
2232                 /*
2233                  * if the function of acpi_video_register is already called,
2234                  * don't register the acpi_video_bus again and return no error.
2235                  */
2236                 goto leave;
2237         }
2238
2239         if (only_lcd == -1)
2240                 only_lcd = should_check_lcd_flag();
2241
2242         dmi_check_system(video_dmi_table);
2243
2244         ret = acpi_bus_register_driver(&acpi_video_bus);
2245         if (ret)
2246                 goto leave;
2247
2248         /*
2249          * When the acpi_video_bus is loaded successfully, increase
2250          * the counter reference.
2251          */
2252         register_count = 1;
2253
2254 leave:
2255         mutex_unlock(&register_count_mutex);
2256         return ret;
2257 }
2258 EXPORT_SYMBOL(acpi_video_register);
2259
2260 void acpi_video_unregister(void)
2261 {
2262         mutex_lock(&register_count_mutex);
2263         if (register_count) {
2264                 acpi_bus_unregister_driver(&acpi_video_bus);
2265                 register_count = 0;
2266                 may_report_brightness_keys = false;
2267         }
2268         mutex_unlock(&register_count_mutex);
2269 }
2270 EXPORT_SYMBOL(acpi_video_unregister);
2271
2272 void acpi_video_unregister_backlight(void)
2273 {
2274         struct acpi_video_bus *video;
2275
2276         mutex_lock(&register_count_mutex);
2277         if (register_count) {
2278                 mutex_lock(&video_list_lock);
2279                 list_for_each_entry(video, &video_bus_head, entry)
2280                         acpi_video_bus_unregister_backlight(video);
2281                 mutex_unlock(&video_list_lock);
2282         }
2283         mutex_unlock(&register_count_mutex);
2284 }
2285
2286 bool acpi_video_handles_brightness_key_presses(void)
2287 {
2288         return may_report_brightness_keys &&
2289                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2290 }
2291 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2292
2293 /*
2294  * This is kind of nasty. Hardware using Intel chipsets may require
2295  * the video opregion code to be run first in order to initialise
2296  * state before any ACPI video calls are made. To handle this we defer
2297  * registration of the video class until the opregion code has run.
2298  */
2299
2300 static int __init acpi_video_init(void)
2301 {
2302         /*
2303          * Let the module load even if ACPI is disabled (e.g. due to
2304          * a broken BIOS) so that i915.ko can still be loaded on such
2305          * old systems without an AcpiOpRegion.
2306          *
2307          * acpi_video_register() will report -ENODEV later as well due
2308          * to acpi_disabled when i915.ko tries to register itself afterwards.
2309          */
2310         if (acpi_disabled)
2311                 return 0;
2312
2313         if (intel_opregion_present())
2314                 return 0;
2315
2316         return acpi_video_register();
2317 }
2318
2319 static void __exit acpi_video_exit(void)
2320 {
2321         acpi_video_detect_exit();
2322         acpi_video_unregister();
2323 }
2324
2325 module_init(acpi_video_init);
2326 module_exit(acpi_video_exit);