drivers/acpi/acpi_video.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  video.c - ACPI Video Driver
   4  *
   5  *  Copyright (C) 2004 Luming Yu <[email protected]>
   6  *  Copyright (C) 2004 Bruno Ducrot <[email protected]>
   7  *  Copyright (C) 2006 Thomas Tuttle <[email protected]>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/init.h>
  13 #include <linux/types.h>
  14 #include <linux/list.h>
  15 #include <linux/mutex.h>
  16 #include <linux/input.h>
  17 #include <linux/backlight.h>
  18 #include <linux/thermal.h>
  19 #include <linux/sort.h>
  20 #include <linux/pci.h>
  21 #include <linux/pci_ids.h>
  22 #include <linux/slab.h>
  23 #include <linux/dmi.h>
  24 #include <linux/suspend.h>
  25 #include <linux/acpi.h>
  26 #include <acpi/video.h>
  27 #include <linux/uaccess.h>
  28
  29 #define PREFIX "ACPI: "
  30
  31 #define ACPI_VIDEO_BUS_NAME             "Video Bus"
  32 #define ACPI_VIDEO_DEVICE_NAME          "Video Device"
  33
  34 #define MAX_NAME_LEN    20
  35
  36 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  37 ACPI_MODULE_NAME("video");
  38
  39 MODULE_AUTHOR("Bruno Ducrot");
  40 MODULE_DESCRIPTION("ACPI Video Driver");
  41 MODULE_LICENSE("GPL");
  42
  43 static bool brightness_switch_enabled = true;
  44 module_param(brightness_switch_enabled, bool, 0644);
  45
  46 /*
  47  * By default, we don't allow duplicate ACPI video bus devices
  48  * under the same VGA controller
  49  */
  50 static bool allow_duplicates;
  51 module_param(allow_duplicates, bool, 0644);
  52
  53 static int disable_backlight_sysfs_if = -1;
  54 module_param(disable_backlight_sysfs_if, int, 0444);
  55
  56 #define REPORT_OUTPUT_KEY_EVENTS                0x01
  57 #define REPORT_BRIGHTNESS_KEY_EVENTS            0x02
  58 static int report_key_events = -1;
  59 module_param(report_key_events, int, 0644);
  60 MODULE_PARM_DESC(report_key_events,
  61         "0: none, 1: output changes, 2: brightness changes, 3: all");
  62
  63 static int hw_changes_brightness = -1;
  64 module_param(hw_changes_brightness, int, 0644);
  65 MODULE_PARM_DESC(hw_changes_brightness,
  66         "Set this to 1 on buggy hw which changes the brightness itself when "
  67         "a hotkey is pressed: -1: auto, 0: normal 1: hw-changes-brightness");
  68
  69 /*
  70  * Whether the struct acpi_video_device_attrib::device_id_scheme bit should be
  71  * assumed even if not actually set.
  72  */
  73 static bool device_id_scheme = false;
  74 module_param(device_id_scheme, bool, 0444);
  75
  76 static int only_lcd = -1;
  77 module_param(only_lcd, int, 0444);
  78
  79 static int register_count;
  80 static DEFINE_MUTEX(register_count_mutex);
  81 static DEFINE_MUTEX(video_list_lock);
  82 static LIST_HEAD(video_bus_head);
  83 static int acpi_video_bus_add(struct acpi_device *device);
  84 static int acpi_video_bus_remove(struct acpi_device *device);
  85 static void acpi_video_bus_notify(struct acpi_device *device, u32 event);
  86 void acpi_video_detect_exit(void);
  87
  88 /*
  89  * Indices in the _BCL method response: the first two items are special,
  90  * the rest are all supported levels.
  91  *
  92  * See page 575 of the ACPI spec 3.0
  93  */
  94 enum acpi_video_level_idx {
  95         ACPI_VIDEO_AC_LEVEL,            /* level when machine has full power */
  96         ACPI_VIDEO_BATTERY_LEVEL,       /* level when machine is on batteries */
  97         ACPI_VIDEO_FIRST_LEVEL,         /* actual supported levels begin here */
  98 };
  99
 100 static const struct acpi_device_id video_device_ids[] = {
 101         {ACPI_VIDEO_HID, 0},
 102         {"", 0},
 103 };
 104 MODULE_DEVICE_TABLE(acpi, video_device_ids);
 105
 106 static struct acpi_driver acpi_video_bus = {
 107         .name = "video",
 108         .class = ACPI_VIDEO_CLASS,
 109         .ids = video_device_ids,
 110         .ops = {
 111                 .add = acpi_video_bus_add,
 112                 .remove = acpi_video_bus_remove,
 113                 .notify = acpi_video_bus_notify,
 114                 },
 115 };
 116
 117 struct acpi_video_bus_flags {
 118         u8 multihead:1;         /* can switch video heads */
 119         u8 rom:1;               /* can retrieve a video rom */
 120         u8 post:1;              /* can configure the head to */
 121         u8 reserved:5;
 122 };
 123
 124 struct acpi_video_bus_cap {
 125         u8 _DOS:1;              /* Enable/Disable output switching */
 126         u8 _DOD:1;              /* Enumerate all devices attached to display adapter */
 127         u8 _ROM:1;              /* Get ROM Data */
 128         u8 _GPD:1;              /* Get POST Device */
 129         u8 _SPD:1;              /* Set POST Device */
 130         u8 _VPO:1;              /* Video POST Options */
 131         u8 reserved:2;
 132 };
 133
 134 struct acpi_video_device_attrib {
 135         u32 display_index:4;    /* A zero-based instance of the Display */
 136         u32 display_port_attachment:4;  /* This field differentiates the display type */
 137         u32 display_type:4;     /* Describe the specific type in use */
 138         u32 vendor_specific:4;  /* Chipset Vendor Specific */
 139         u32 bios_can_detect:1;  /* BIOS can detect the device */
 140         u32 depend_on_vga:1;    /* Non-VGA output device whose power is related to
 141                                    the VGA device. */
 142         u32 pipe_id:3;          /* For VGA multiple-head devices. */
 143         u32 reserved:10;        /* Must be 0 */
 144
 145         /*
 146          * The device ID might not actually follow the scheme described by this
 147          * struct acpi_video_device_attrib. If it does, then this bit
 148          * device_id_scheme is set; otherwise, other fields should be ignored.
 149          *
 150          * (but also see the global flag device_id_scheme)
 151          */
 152         u32 device_id_scheme:1;
 153 };
 154
 155 struct acpi_video_enumerated_device {
 156         union {
 157                 u32 int_val;
 158                 struct acpi_video_device_attrib attrib;
 159         } value;
 160         struct acpi_video_device *bind_info;
 161 };
 162
 163 struct acpi_video_bus {
 164         struct acpi_device *device;
 165         bool backlight_registered;
 166         u8 dos_setting;
 167         struct acpi_video_enumerated_device *attached_array;
 168         u8 attached_count;
 169         u8 child_count;
 170         struct acpi_video_bus_cap cap;
 171         struct acpi_video_bus_flags flags;
 172         struct list_head video_device_list;
 173         struct mutex device_list_lock;  /* protects video_device_list */
 174         struct list_head entry;
 175         struct input_dev *input;
 176         char phys[32];  /* for input device */
 177         struct notifier_block pm_nb;
 178 };
 179
 180 struct acpi_video_device_flags {
 181         u8 crt:1;
 182         u8 lcd:1;
 183         u8 tvout:1;
 184         u8 dvi:1;
 185         u8 bios:1;
 186         u8 unknown:1;
 187         u8 notify:1;
 188         u8 reserved:1;
 189 };
 190
 191 struct acpi_video_device_cap {
 192         u8 _ADR:1;              /* Return the unique ID */
 193         u8 _BCL:1;              /* Query list of brightness control levels supported */
 194         u8 _BCM:1;              /* Set the brightness level */
 195         u8 _BQC:1;              /* Get current brightness level */
 196         u8 _BCQ:1;              /* Some buggy BIOS uses _BCQ instead of _BQC */
 197         u8 _DDC:1;              /* Return the EDID for this device */
 198 };
 199
 200 struct acpi_video_device {
 201         unsigned long device_id;
 202         struct acpi_video_device_flags flags;
 203         struct acpi_video_device_cap cap;
 204         struct list_head entry;
 205         struct delayed_work switch_brightness_work;
 206         int switch_brightness_event;
 207         struct acpi_video_bus *video;
 208         struct acpi_device *dev;
 209         struct acpi_video_device_brightness *brightness;
 210         struct backlight_device *backlight;
 211         struct thermal_cooling_device *cooling_dev;
 212 };
 213
 214 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data);
 215 static void acpi_video_device_rebind(struct acpi_video_bus *video);
 216 static void acpi_video_device_bind(struct acpi_video_bus *video,
 217                                    struct acpi_video_device *device);
 218 static int acpi_video_device_enumerate(struct acpi_video_bus *video);
 219 static int acpi_video_device_lcd_set_level(struct acpi_video_device *device,
 220                         int level);
 221 static int acpi_video_device_lcd_get_level_current(
 222                         struct acpi_video_device *device,
 223                         unsigned long long *level, bool raw);
 224 static int acpi_video_get_next_level(struct acpi_video_device *device,
 225                                      u32 level_current, u32 event);
 226 static void acpi_video_switch_brightness(struct work_struct *work);
 227
 228 /* backlight device sysfs support */
 229 static int acpi_video_get_brightness(struct backlight_device *bd)
 230 {
 231         unsigned long long cur_level;
 232         int i;
 233         struct acpi_video_device *vd = bl_get_data(bd);
 234
 235         if (acpi_video_device_lcd_get_level_current(vd, &cur_level, false))
 236                 return -EINVAL;
 237         for (i = ACPI_VIDEO_FIRST_LEVEL; i < vd->brightness->count; i++) {
 238                 if (vd->brightness->levels[i] == cur_level)
 239                         return i - ACPI_VIDEO_FIRST_LEVEL;
 240         }
 241         return 0;
 242 }
 243
 244 static int acpi_video_set_brightness(struct backlight_device *bd)
 245 {
 246         int request_level = bd->props.brightness + ACPI_VIDEO_FIRST_LEVEL;
 247         struct acpi_video_device *vd = bl_get_data(bd);
 248
 249         cancel_delayed_work(&vd->switch_brightness_work);
 250         return acpi_video_device_lcd_set_level(vd,
 251                                 vd->brightness->levels[request_level]);
 252 }
 253
 254 static const struct backlight_ops acpi_backlight_ops = {
 255         .get_brightness = acpi_video_get_brightness,
 256         .update_status  = acpi_video_set_brightness,
 257 };
 258
 259 /* thermal cooling device callbacks */
 260 static int video_get_max_state(struct thermal_cooling_device *cooling_dev,
 261                                unsigned long *state)
 262 {
 263         struct acpi_device *device = cooling_dev->devdata;
 264         struct acpi_video_device *video = acpi_driver_data(device);
 265
 266         *state = video->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
 267         return 0;
 268 }
 269
 270 static int video_get_cur_state(struct thermal_cooling_device *cooling_dev,
 271                                unsigned long *state)
 272 {
 273         struct acpi_device *device = cooling_dev->devdata;
 274         struct acpi_video_device *video = acpi_driver_data(device);
 275         unsigned long long level;
 276         int offset;
 277
 278         if (acpi_video_device_lcd_get_level_current(video, &level, false))
 279                 return -EINVAL;
 280         for (offset = ACPI_VIDEO_FIRST_LEVEL; offset < video->brightness->count;
 281              offset++)
 282                 if (level == video->brightness->levels[offset]) {
 283                         *state = video->brightness->count - offset - 1;
 284                         return 0;
 285                 }
 286
 287         return -EINVAL;
 288 }
 289
 290 static int
 291 video_set_cur_state(struct thermal_cooling_device *cooling_dev, unsigned long state)
 292 {
 293         struct acpi_device *device = cooling_dev->devdata;
 294         struct acpi_video_device *video = acpi_driver_data(device);
 295         int level;
 296
 297         if (state >= video->brightness->count - ACPI_VIDEO_FIRST_LEVEL)
 298                 return -EINVAL;
 299
 300         state = video->brightness->count - state;
 301         level = video->brightness->levels[state - 1];
 302         return acpi_video_device_lcd_set_level(video, level);
 303 }
 304
 305 static const struct thermal_cooling_device_ops video_cooling_ops = {
 306         .get_max_state = video_get_max_state,
 307         .get_cur_state = video_get_cur_state,
 308         .set_cur_state = video_set_cur_state,
 309 };
 310
 311 /*
 312  * --------------------------------------------------------------------------
 313  *                             Video Management
 314  * --------------------------------------------------------------------------
 315  */
 316
 317 static int
 318 acpi_video_device_lcd_query_levels(acpi_handle handle,
 319                                    union acpi_object **levels)
 320 {
 321         int status;
 322         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 323         union acpi_object *obj;
 324
 325
 326         *levels = NULL;
 327
 328         status = acpi_evaluate_object(handle, "_BCL", NULL, &buffer);
 329         if (!ACPI_SUCCESS(status))
 330                 return status;
 331         obj = (union acpi_object *)buffer.pointer;
 332         if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) {
 333                 printk(KERN_ERR PREFIX "Invalid _BCL data\n");
 334                 status = -EFAULT;
 335                 goto err;
 336         }
 337
 338         *levels = obj;
 339
 340         return 0;
 341
 342 err:
 343         kfree(buffer.pointer);
 344
 345         return status;
 346 }
 347
 348 static int
 349 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 350 {
 351         int status;
 352         int state;
 353
 354         status = acpi_execute_simple_method(device->dev->handle,
 355                                             "_BCM", level);
 356         if (ACPI_FAILURE(status)) {
 357                 ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
 358                 return -EIO;
 359         }
 360
 361         device->brightness->curr = level;
 362         for (state = ACPI_VIDEO_FIRST_LEVEL; state < device->brightness->count;
 363              state++)
 364                 if (level == device->brightness->levels[state]) {
 365                         if (device->backlight)
 366                                 device->backlight->props.brightness =
 367                                         state - ACPI_VIDEO_FIRST_LEVEL;
 368                         return 0;
 369                 }
 370
 371         ACPI_ERROR((AE_INFO, "Current brightness invalid"));
 372         return -EINVAL;
 373 }
 374
 375 /*
 376  * For some buggy _BQC methods, we need to add a constant value to
 377  * the _BQC return value to get the actual current brightness level
 378  */
 379
 380 static int bqc_offset_aml_bug_workaround;
 381 static int video_set_bqc_offset(const struct dmi_system_id *d)
 382 {
 383         bqc_offset_aml_bug_workaround = 9;
 384         return 0;
 385 }
 386
 387 static int video_disable_backlight_sysfs_if(
 388         const struct dmi_system_id *d)
 389 {
 390         if (disable_backlight_sysfs_if == -1)
 391                 disable_backlight_sysfs_if = 1;
 392         return 0;
 393 }
 394
 395 static int video_set_device_id_scheme(const struct dmi_system_id *d)
 396 {
 397         device_id_scheme = true;
 398         return 0;
 399 }
 400
 401 static int video_enable_only_lcd(const struct dmi_system_id *d)
 402 {
 403         only_lcd = true;
 404         return 0;
 405 }
 406
 407 static int video_set_report_key_events(const struct dmi_system_id *id)
 408 {
 409         if (report_key_events == -1)
 410                 report_key_events = (uintptr_t)id->driver_data;
 411         return 0;
 412 }
 413
 414 static int video_hw_changes_brightness(
 415         const struct dmi_system_id *d)
 416 {
 417         if (hw_changes_brightness == -1)
 418                 hw_changes_brightness = 1;
 419         return 0;
 420 }
 421
 422 static const struct dmi_system_id video_dmi_table[] = {
 423         /*
 424          * Broken _BQC workaround http://bugzilla.kernel.org/show_bug.cgi?id=13121
 425          */
 426         {
 427          .callback = video_set_bqc_offset,
 428          .ident = "Acer Aspire 5720",
 429          .matches = {
 430                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 431                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5720"),
 432                 },
 433         },
 434         {
 435          .callback = video_set_bqc_offset,
 436          .ident = "Acer Aspire 5710Z",
 437          .matches = {
 438                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 439                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5710Z"),
 440                 },
 441         },
 442         {
 443          .callback = video_set_bqc_offset,
 444          .ident = "eMachines E510",
 445          .matches = {
 446                 DMI_MATCH(DMI_BOARD_VENDOR, "EMACHINES"),
 447                 DMI_MATCH(DMI_PRODUCT_NAME, "eMachines E510"),
 448                 },
 449         },
 450         {
 451          .callback = video_set_bqc_offset,
 452          .ident = "Acer Aspire 5315",
 453          .matches = {
 454                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 455                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 5315"),
 456                 },
 457         },
 458         {
 459          .callback = video_set_bqc_offset,
 460          .ident = "Acer Aspire 7720",
 461          .matches = {
 462                 DMI_MATCH(DMI_BOARD_VENDOR, "Acer"),
 463                 DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 7720"),
 464                 },
 465         },
 466
 467         /*
 468          * Some machines have a broken acpi-video interface for brightness
 469          * control, but still need an acpi_video_device_lcd_set_level() call
 470          * on resume to turn the backlight power on.  We Enable backlight
 471          * control on these systems, but do not register a backlight sysfs
 472          * as brightness control does not work.
 473          */
 474         {
 475          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 476          .callback = video_disable_backlight_sysfs_if,
 477          .ident = "Toshiba Portege R700",
 478          .matches = {
 479                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 480                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R700"),
 481                 },
 482         },
 483         {
 484          /* https://bugs.freedesktop.org/show_bug.cgi?id=82634 */
 485          .callback = video_disable_backlight_sysfs_if,
 486          .ident = "Toshiba Portege R830",
 487          .matches = {
 488                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 489                 DMI_MATCH(DMI_PRODUCT_NAME, "PORTEGE R830"),
 490                 },
 491         },
 492         {
 493          /* https://bugzilla.kernel.org/show_bug.cgi?id=21012 */
 494          .callback = video_disable_backlight_sysfs_if,
 495          .ident = "Toshiba Satellite R830",
 496          .matches = {
 497                 DMI_MATCH(DMI_SYS_VENDOR, "TOSHIBA"),
 498                 DMI_MATCH(DMI_PRODUCT_NAME, "SATELLITE R830"),
 499                 },
 500         },
 501         /*
 502          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 503          * but the IDs actually follow the Device ID Scheme.
 504          */
 505         {
 506          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 507          .callback = video_set_device_id_scheme,
 508          .ident = "ESPRIMO Mobile M9410",
 509          .matches = {
 510                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 511                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 512                 },
 513         },
 514         /*
 515          * Some machines have multiple video output devices, but only the one
 516          * that is the type of LCD can do the backlight control so we should not
 517          * register backlight interface for other video output devices.
 518          */
 519         {
 520          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 521          .callback = video_enable_only_lcd,
 522          .ident = "ESPRIMO Mobile M9410",
 523          .matches = {
 524                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 525                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 526                 },
 527         },
 528         /*
 529          * Some machines report wrong key events on the acpi-bus, suppress
 530          * key event reporting on these.  Note this is only intended to work
 531          * around events which are plain wrong. In some cases we get double
 532          * events, in this case acpi-video is considered the canonical source
 533          * and the events from the other source should be filtered. E.g.
 534          * by calling acpi_video_handles_brightness_key_presses() from the
 535          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 536          */
 537         {
 538          .callback = video_set_report_key_events,
 539          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 540          .ident = "Dell Vostro V131",
 541          .matches = {
 542                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 543                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 544                 },
 545         },
 546         /*
 547          * Some machines change the brightness themselves when a brightness
 548          * hotkey gets pressed, despite us telling them not to. In this case
 549          * acpi_video_device_notify() should only call backlight_force_update(
 550          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 551          */
 552         {
 553          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 554          .callback = video_hw_changes_brightness,
 555          .ident = "Packard Bell EasyNote MZ35",
 556          .matches = {
 557                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 558                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 559                 },
 560         },
 561         {}
 562 };
 563
 564 static unsigned long long
 565 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 566                               unsigned long long bqc_value)
 567 {
 568         unsigned long long level;
 569
 570         if (device->brightness->flags._BQC_use_index) {
 571                 /*
 572                  * _BQC returns an index that doesn't account for the first 2
 573                  * items with special meaning (see enum acpi_video_level_idx),
 574                  * so we need to compensate for that by offsetting ourselves
 575                  */
 576                 if (device->brightness->flags._BCL_reversed)
 577                         bqc_value = device->brightness->count -
 578                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 579
 580                 level = device->brightness->levels[bqc_value +
 581                                                    ACPI_VIDEO_FIRST_LEVEL];
 582         } else {
 583                 level = bqc_value;
 584         }
 585
 586         level += bqc_offset_aml_bug_workaround;
 587
 588         return level;
 589 }
 590
 591 static int
 592 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 593                                         unsigned long long *level, bool raw)
 594 {
 595         acpi_status status = AE_OK;
 596         int i;
 597
 598         if (device->cap._BQC || device->cap._BCQ) {
 599                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 600
 601                 status = acpi_evaluate_integer(device->dev->handle, buf,
 602                                                 NULL, level);
 603                 if (ACPI_SUCCESS(status)) {
 604                         if (raw) {
 605                                 /*
 606                                  * Caller has indicated he wants the raw
 607                                  * value returned by _BQC, so don't furtherly
 608                                  * mess with the value.
 609                                  */
 610                                 return 0;
 611                         }
 612
 613                         *level = acpi_video_bqc_value_to_level(device, *level);
 614
 615                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 616                              i < device->brightness->count; i++)
 617                                 if (device->brightness->levels[i] == *level) {
 618                                         device->brightness->curr = *level;
 619                                         return 0;
 620                                 }
 621                         /*
 622                          * BQC returned an invalid level.
 623                          * Stop using it.
 624                          */
 625                         ACPI_WARNING((AE_INFO,
 626                                       "%s returned an invalid level",
 627                                       buf));
 628                         device->cap._BQC = device->cap._BCQ = 0;
 629                 } else {
 630                         /*
 631                          * Fixme:
 632                          * should we return an error or ignore this failure?
 633                          * dev->brightness->curr is a cached value which stores
 634                          * the correct current backlight level in most cases.
 635                          * ACPI video backlight still works w/ buggy _BQC.
 636                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 637                          */
 638                         ACPI_WARNING((AE_INFO, "Evaluating %s failed", buf));
 639                         device->cap._BQC = device->cap._BCQ = 0;
 640                 }
 641         }
 642
 643         *level = device->brightness->curr;
 644         return 0;
 645 }
 646
 647 static int
 648 acpi_video_device_EDID(struct acpi_video_device *device,
 649                        union acpi_object **edid, ssize_t length)
 650 {
 651         int status;
 652         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 653         union acpi_object *obj;
 654         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 655         struct acpi_object_list args = { 1, &arg0 };
 656
 657
 658         *edid = NULL;
 659
 660         if (!device)
 661                 return -ENODEV;
 662         if (length == 128)
 663                 arg0.integer.value = 1;
 664         else if (length == 256)
 665                 arg0.integer.value = 2;
 666         else
 667                 return -EINVAL;
 668
 669         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 670         if (ACPI_FAILURE(status))
 671                 return -ENODEV;
 672
 673         obj = buffer.pointer;
 674
 675         if (obj && obj->type == ACPI_TYPE_BUFFER)
 676                 *edid = obj;
 677         else {
 678                 printk(KERN_ERR PREFIX "Invalid _DDC data\n");
 679                 status = -EFAULT;
 680                 kfree(obj);
 681         }
 682
 683         return status;
 684 }
 685
 686 /* bus */
 687
 688 /*
 689  *  Arg:
 690  *      video           : video bus device pointer
 691  *      bios_flag       :
 692  *              0.      The system BIOS should NOT automatically switch(toggle)
 693  *                      the active display output.
 694  *              1.      The system BIOS should automatically switch (toggle) the
 695  *                      active display output. No switch event.
 696  *              2.      The _DGS value should be locked.
 697  *              3.      The system BIOS should not automatically switch (toggle) the
 698  *                      active display output, but instead generate the display switch
 699  *                      event notify code.
 700  *      lcd_flag        :
 701  *              0.      The system BIOS should automatically control the brightness level
 702  *                      of the LCD when:
 703  *                      - the power changes from AC to DC (ACPI appendix B)
 704  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 705  *              1.      The system BIOS should NOT automatically control the brightness
 706  *                      level of the LCD when:
 707  *                      - the power changes from AC to DC (ACPI appendix B)
 708  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 709  *  Return Value:
 710  *              -EINVAL wrong arg.
 711  */
 712
 713 static int
 714 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 715 {
 716         acpi_status status;
 717
 718         if (!video->cap._DOS)
 719                 return 0;
 720
 721         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 722                 return -EINVAL;
 723         video->dos_setting = (lcd_flag << 2) | bios_flag;
 724         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 725                                             (lcd_flag << 2) | bios_flag);
 726         if (ACPI_FAILURE(status))
 727                 return -EIO;
 728
 729         return 0;
 730 }
 731
 732 /*
 733  * Simple comparison function used to sort backlight levels.
 734  */
 735
 736 static int
 737 acpi_video_cmp_level(const void *a, const void *b)
 738 {
 739         return *(int *)a - *(int *)b;
 740 }
 741
 742 /*
 743  * Decides if _BQC/_BCQ for this system is usable
 744  *
 745  * We do this by changing the level first and then read out the current
 746  * brightness level, if the value does not match, find out if it is using
 747  * index. If not, clear the _BQC/_BCQ capability.
 748  */
 749 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 750                                 int max_level, int current_level)
 751 {
 752         struct acpi_video_device_brightness *br = device->brightness;
 753         int result;
 754         unsigned long long level;
 755         int test_level;
 756
 757         /* don't mess with existing known broken systems */
 758         if (bqc_offset_aml_bug_workaround)
 759                 return 0;
 760
 761         /*
 762          * Some systems always report current brightness level as maximum
 763          * through _BQC, we need to test another value for them. However,
 764          * there is a subtlety:
 765          *
 766          * If the _BCL package ordering is descending, the first level
 767          * (br->levels[2]) is likely to be 0, and if the number of levels
 768          * matches the number of steps, we might confuse a returned level to
 769          * mean the index.
 770          *
 771          * For example:
 772          *
 773          *     current_level = max_level = 100
 774          *     test_level = 0
 775          *     returned level = 100
 776          *
 777          * In this case 100 means the level, not the index, and _BCM failed.
 778          * Still, if the _BCL package ordering is descending, the index of
 779          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 780          *
 781          * This causes all _BQC calls to return bogus values causing weird
 782          * behavior from the user's perspective.  For example:
 783          *
 784          * xbacklight -set 10; xbacklight -set 20;
 785          *
 786          * would flash to 90% and then slowly down to the desired level (20).
 787          *
 788          * The solution is simple; test anything other than the first level
 789          * (e.g. 1).
 790          */
 791         test_level = current_level == max_level
 792                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 793                 : max_level;
 794
 795         result = acpi_video_device_lcd_set_level(device, test_level);
 796         if (result)
 797                 return result;
 798
 799         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 800         if (result)
 801                 return result;
 802
 803         if (level != test_level) {
 804                 /* buggy _BQC found, need to find out if it uses index */
 805                 if (level < br->count) {
 806                         if (br->flags._BCL_reversed)
 807                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 808                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 809                                 br->flags._BQC_use_index = 1;
 810                 }
 811
 812                 if (!br->flags._BQC_use_index)
 813                         device->cap._BQC = device->cap._BCQ = 0;
 814         }
 815
 816         return 0;
 817 }
 818
 819 int acpi_video_get_levels(struct acpi_device *device,
 820                           struct acpi_video_device_brightness **dev_br,
 821                           int *pmax_level)
 822 {
 823         union acpi_object *obj = NULL;
 824         int i, max_level = 0, count = 0, level_ac_battery = 0;
 825         union acpi_object *o;
 826         struct acpi_video_device_brightness *br = NULL;
 827         int result = 0;
 828         u32 value;
 829
 830         if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device->handle,
 831                                                                 &obj))) {
 832                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
 833                                                 "LCD brightness level\n"));
 834                 result = -ENODEV;
 835                 goto out;
 836         }
 837
 838         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 839                 result = -EINVAL;
 840                 goto out;
 841         }
 842
 843         br = kzalloc(sizeof(*br), GFP_KERNEL);
 844         if (!br) {
 845                 printk(KERN_ERR "can't allocate memory\n");
 846                 result = -ENOMEM;
 847                 goto out;
 848         }
 849
 850         /*
 851          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 852          * in order to account for buggy BIOS which don't export the first two
 853          * special levels (see below)
 854          */
 855         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 856                                    sizeof(*br->levels),
 857                                    GFP_KERNEL);
 858         if (!br->levels) {
 859                 result = -ENOMEM;
 860                 goto out_free;
 861         }
 862
 863         for (i = 0; i < obj->package.count; i++) {
 864                 o = (union acpi_object *)&obj->package.elements[i];
 865                 if (o->type != ACPI_TYPE_INTEGER) {
 866                         printk(KERN_ERR PREFIX "Invalid data\n");
 867                         continue;
 868                 }
 869                 value = (u32) o->integer.value;
 870                 /* Skip duplicate entries */
 871                 if (count > ACPI_VIDEO_FIRST_LEVEL
 872                     && br->levels[count - 1] == value)
 873                         continue;
 874
 875                 br->levels[count] = value;
 876
 877                 if (br->levels[count] > max_level)
 878                         max_level = br->levels[count];
 879                 count++;
 880         }
 881
 882         /*
 883          * some buggy BIOS don't export the levels
 884          * when machine is on AC/Battery in _BCL package.
 885          * In this case, the first two elements in _BCL packages
 886          * are also supported brightness levels that OS should take care of.
 887          */
 888         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 889                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 890                         level_ac_battery++;
 891                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 892                         level_ac_battery++;
 893         }
 894
 895         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 896                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 897                 br->flags._BCL_no_ac_battery_levels = 1;
 898                 for (i = (count - 1 + level_ac_battery);
 899                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 900                         br->levels[i] = br->levels[i - level_ac_battery];
 901                 count += level_ac_battery;
 902         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 903                 ACPI_ERROR((AE_INFO, "Too many duplicates in _BCL package"));
 904
 905         /* Check if the _BCL package is in a reversed order */
 906         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 907                 br->flags._BCL_reversed = 1;
 908                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 909                      count - ACPI_VIDEO_FIRST_LEVEL,
 910                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 911                      acpi_video_cmp_level, NULL);
 912         } else if (max_level != br->levels[count - 1])
 913                 ACPI_ERROR((AE_INFO,
 914                             "Found unordered _BCL package"));
 915
 916         br->count = count;
 917         *dev_br = br;
 918         if (pmax_level)
 919                 *pmax_level = max_level;
 920
 921 out:
 922         kfree(obj);
 923         return result;
 924 out_free:
 925         kfree(br);
 926         goto out;
 927 }
 928 EXPORT_SYMBOL(acpi_video_get_levels);
 929
 930 /*
 931  *  Arg:
 932  *      device  : video output device (LCD, CRT, ..)
 933  *
 934  *  Return Value:
 935  *      Maximum brightness level
 936  *
 937  *  Allocate and initialize device->brightness.
 938  */
 939
 940 static int
 941 acpi_video_init_brightness(struct acpi_video_device *device)
 942 {
 943         int i, max_level = 0;
 944         unsigned long long level, level_old;
 945         struct acpi_video_device_brightness *br = NULL;
 946         int result;
 947
 948         result = acpi_video_get_levels(device->dev, &br, &max_level);
 949         if (result)
 950                 return result;
 951         device->brightness = br;
 952
 953         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 954         br->curr = level = max_level;
 955
 956         if (!device->cap._BQC)
 957                 goto set_level;
 958
 959         result = acpi_video_device_lcd_get_level_current(device,
 960                                                          &level_old, true);
 961         if (result)
 962                 goto out_free_levels;
 963
 964         result = acpi_video_bqc_quirk(device, max_level, level_old);
 965         if (result)
 966                 goto out_free_levels;
 967         /*
 968          * cap._BQC may get cleared due to _BQC is found to be broken
 969          * in acpi_video_bqc_quirk, so check again here.
 970          */
 971         if (!device->cap._BQC)
 972                 goto set_level;
 973
 974         level = acpi_video_bqc_value_to_level(device, level_old);
 975         /*
 976          * On some buggy laptops, _BQC returns an uninitialized
 977          * value when invoked for the first time, i.e.
 978          * level_old is invalid (no matter whether it's a level
 979          * or an index). Set the backlight to max_level in this case.
 980          */
 981         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 982                 if (level == br->levels[i])
 983                         break;
 984         if (i == br->count || !level)
 985                 level = max_level;
 986
 987 set_level:
 988         result = acpi_video_device_lcd_set_level(device, level);
 989         if (result)
 990                 goto out_free_levels;
 991
 992         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 993                           "found %d brightness levels\n",
 994                           br->count - ACPI_VIDEO_FIRST_LEVEL));
 995         return 0;
 996
 997 out_free_levels:
 998         kfree(br->levels);
 999         kfree(br);
1000         device->brightness = NULL;
1001         return result;
1002 }
1003
1004 /*
1005  *  Arg:
1006  *      device  : video output device (LCD, CRT, ..)
1007  *
1008  *  Return Value:
1009  *      None
1010  *
1011  *  Find out all required AML methods defined under the output
1012  *  device.
1013  */
1014
1015 static void acpi_video_device_find_cap(struct acpi_video_device *device)
1016 {
1017         if (acpi_has_method(device->dev->handle, "_ADR"))
1018                 device->cap._ADR = 1;
1019         if (acpi_has_method(device->dev->handle, "_BCL"))
1020                 device->cap._BCL = 1;
1021         if (acpi_has_method(device->dev->handle, "_BCM"))
1022                 device->cap._BCM = 1;
1023         if (acpi_has_method(device->dev->handle, "_BQC")) {
1024                 device->cap._BQC = 1;
1025         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1026                 printk(KERN_WARNING FW_BUG "_BCQ is used instead of _BQC\n");
1027                 device->cap._BCQ = 1;
1028         }
1029
1030         if (acpi_has_method(device->dev->handle, "_DDC"))
1031                 device->cap._DDC = 1;
1032 }
1033
1034 /*
1035  *  Arg:
1036  *      device  : video output device (VGA)
1037  *
1038  *  Return Value:
1039  *      None
1040  *
1041  *  Find out all required AML methods defined under the video bus device.
1042  */
1043
1044 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1045 {
1046         if (acpi_has_method(video->device->handle, "_DOS"))
1047                 video->cap._DOS = 1;
1048         if (acpi_has_method(video->device->handle, "_DOD"))
1049                 video->cap._DOD = 1;
1050         if (acpi_has_method(video->device->handle, "_ROM"))
1051                 video->cap._ROM = 1;
1052         if (acpi_has_method(video->device->handle, "_GPD"))
1053                 video->cap._GPD = 1;
1054         if (acpi_has_method(video->device->handle, "_SPD"))
1055                 video->cap._SPD = 1;
1056         if (acpi_has_method(video->device->handle, "_VPO"))
1057                 video->cap._VPO = 1;
1058 }
1059
1060 /*
1061  * Check whether the video bus device has required AML method to
1062  * support the desired features
1063  */
1064
1065 static int acpi_video_bus_check(struct acpi_video_bus *video)
1066 {
1067         acpi_status status = -ENOENT;
1068         struct pci_dev *dev;
1069
1070         if (!video)
1071                 return -EINVAL;
1072
1073         dev = acpi_get_pci_dev(video->device->handle);
1074         if (!dev)
1075                 return -ENODEV;
1076         pci_dev_put(dev);
1077
1078         /*
1079          * Since there is no HID, CID and so on for VGA driver, we have
1080          * to check well known required nodes.
1081          */
1082
1083         /* Does this device support video switching? */
1084         if (video->cap._DOS || video->cap._DOD) {
1085                 if (!video->cap._DOS) {
1086                         printk(KERN_WARNING FW_BUG
1087                                 "ACPI(%s) defines _DOD but not _DOS\n",
1088                                 acpi_device_bid(video->device));
1089                 }
1090                 video->flags.multihead = 1;
1091                 status = 0;
1092         }
1093
1094         /* Does this device support retrieving a video ROM? */
1095         if (video->cap._ROM) {
1096                 video->flags.rom = 1;
1097                 status = 0;
1098         }
1099
1100         /* Does this device support configuring which video device to POST? */
1101         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1102                 video->flags.post = 1;
1103                 status = 0;
1104         }
1105
1106         return status;
1107 }
1108
1109 /*
1110  * --------------------------------------------------------------------------
1111  *                               Driver Interface
1112  * --------------------------------------------------------------------------
1113  */
1114
1115 /* device interface */
1116 static struct acpi_video_device_attrib *
1117 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1118 {
1119         struct acpi_video_enumerated_device *ids;
1120         int i;
1121
1122         for (i = 0; i < video->attached_count; i++) {
1123                 ids = &video->attached_array[i];
1124                 if ((ids->value.int_val & 0xffff) == device_id)
1125                         return &ids->value.attrib;
1126         }
1127
1128         return NULL;
1129 }
1130
1131 static int
1132 acpi_video_get_device_type(struct acpi_video_bus *video,
1133                            unsigned long device_id)
1134 {
1135         struct acpi_video_enumerated_device *ids;
1136         int i;
1137
1138         for (i = 0; i < video->attached_count; i++) {
1139                 ids = &video->attached_array[i];
1140                 if ((ids->value.int_val & 0xffff) == device_id)
1141                         return ids->value.int_val;
1142         }
1143
1144         return 0;
1145 }
1146
1147 static int
1148 acpi_video_bus_get_one_device(struct acpi_device *device,
1149                               struct acpi_video_bus *video)
1150 {
1151         unsigned long long device_id;
1152         int status, device_type;
1153         struct acpi_video_device *data;
1154         struct acpi_video_device_attrib *attribute;
1155
1156         status =
1157             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1158         /* Some device omits _ADR, we skip them instead of fail */
1159         if (ACPI_FAILURE(status))
1160                 return 0;
1161
1162         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1163         if (!data)
1164                 return -ENOMEM;
1165
1166         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1167         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1168         device->driver_data = data;
1169
1170         data->device_id = device_id;
1171         data->video = video;
1172         data->dev = device;
1173         INIT_DELAYED_WORK(&data->switch_brightness_work,
1174                           acpi_video_switch_brightness);
1175
1176         attribute = acpi_video_get_device_attr(video, device_id);
1177
1178         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1179                 switch (attribute->display_type) {
1180                 case ACPI_VIDEO_DISPLAY_CRT:
1181                         data->flags.crt = 1;
1182                         break;
1183                 case ACPI_VIDEO_DISPLAY_TV:
1184                         data->flags.tvout = 1;
1185                         break;
1186                 case ACPI_VIDEO_DISPLAY_DVI:
1187                         data->flags.dvi = 1;
1188                         break;
1189                 case ACPI_VIDEO_DISPLAY_LCD:
1190                         data->flags.lcd = 1;
1191                         break;
1192                 default:
1193                         data->flags.unknown = 1;
1194                         break;
1195                 }
1196                 if (attribute->bios_can_detect)
1197                         data->flags.bios = 1;
1198         } else {
1199                 /* Check for legacy IDs */
1200                 device_type = acpi_video_get_device_type(video, device_id);
1201                 /* Ignore bits 16 and 18-20 */
1202                 switch (device_type & 0xffe2ffff) {
1203                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1204                         data->flags.crt = 1;
1205                         break;
1206                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1207                         data->flags.lcd = 1;
1208                         break;
1209                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1210                         data->flags.tvout = 1;
1211                         break;
1212                 default:
1213                         data->flags.unknown = 1;
1214                 }
1215         }
1216
1217         acpi_video_device_bind(video, data);
1218         acpi_video_device_find_cap(data);
1219
1220         mutex_lock(&video->device_list_lock);
1221         list_add_tail(&data->entry, &video->video_device_list);
1222         mutex_unlock(&video->device_list_lock);
1223
1224         return status;
1225 }
1226
1227 /*
1228  *  Arg:
1229  *      video   : video bus device
1230  *
1231  *  Return:
1232  *      none
1233  *
1234  *  Enumerate the video device list of the video bus,
1235  *  bind the ids with the corresponding video devices
1236  *  under the video bus.
1237  */
1238
1239 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1240 {
1241         struct acpi_video_device *dev;
1242
1243         mutex_lock(&video->device_list_lock);
1244
1245         list_for_each_entry(dev, &video->video_device_list, entry)
1246                 acpi_video_device_bind(video, dev);
1247
1248         mutex_unlock(&video->device_list_lock);
1249 }
1250
1251 /*
1252  *  Arg:
1253  *      video   : video bus device
1254  *      device  : video output device under the video
1255  *              bus
1256  *
1257  *  Return:
1258  *      none
1259  *
1260  *  Bind the ids with the corresponding video devices
1261  *  under the video bus.
1262  */
1263
1264 static void
1265 acpi_video_device_bind(struct acpi_video_bus *video,
1266                        struct acpi_video_device *device)
1267 {
1268         struct acpi_video_enumerated_device *ids;
1269         int i;
1270
1271         for (i = 0; i < video->attached_count; i++) {
1272                 ids = &video->attached_array[i];
1273                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1274                         ids->bind_info = device;
1275                         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "device_bind %d\n", i));
1276                 }
1277         }
1278 }
1279
1280 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1281 {
1282         struct acpi_video_bus *video = device->video;
1283         int i;
1284
1285         /*
1286          * If we have a broken _DOD or we have more than 8 output devices
1287          * under the graphics controller node that we can't proper deal with
1288          * in the operation region code currently, no need to test.
1289          */
1290         if (!video->attached_count || video->child_count > 8)
1291                 return true;
1292
1293         for (i = 0; i < video->attached_count; i++) {
1294                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1295                     (device->device_id & 0xfff))
1296                         return true;
1297         }
1298
1299         return false;
1300 }
1301
1302 /*
1303  *  Arg:
1304  *      video   : video bus device
1305  *
1306  *  Return:
1307  *      < 0     : error
1308  *
1309  *  Call _DOD to enumerate all devices attached to display adapter
1310  *
1311  */
1312
1313 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1314 {
1315         int status;
1316         int count;
1317         int i;
1318         struct acpi_video_enumerated_device *active_list;
1319         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1320         union acpi_object *dod = NULL;
1321         union acpi_object *obj;
1322
1323         if (!video->cap._DOD)
1324                 return AE_NOT_EXIST;
1325
1326         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1327         if (!ACPI_SUCCESS(status)) {
1328                 ACPI_EXCEPTION((AE_INFO, status, "Evaluating _DOD"));
1329                 return status;
1330         }
1331
1332         dod = buffer.pointer;
1333         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1334                 ACPI_EXCEPTION((AE_INFO, status, "Invalid _DOD data"));
1335                 status = -EFAULT;
1336                 goto out;
1337         }
1338
1339         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d video heads in _DOD\n",
1340                           dod->package.count));
1341
1342         active_list = kcalloc(1 + dod->package.count,
1343                               sizeof(struct acpi_video_enumerated_device),
1344                               GFP_KERNEL);
1345         if (!active_list) {
1346                 status = -ENOMEM;
1347                 goto out;
1348         }
1349
1350         count = 0;
1351         for (i = 0; i < dod->package.count; i++) {
1352                 obj = &dod->package.elements[i];
1353
1354                 if (obj->type != ACPI_TYPE_INTEGER) {
1355                         printk(KERN_ERR PREFIX
1356                                 "Invalid _DOD data in element %d\n", i);
1357                         continue;
1358                 }
1359
1360                 active_list[count].value.int_val = obj->integer.value;
1361                 active_list[count].bind_info = NULL;
1362                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "dod element[%d] = %d\n", i,
1363                                   (int)obj->integer.value));
1364                 count++;
1365         }
1366
1367         kfree(video->attached_array);
1368
1369         video->attached_array = active_list;
1370         video->attached_count = count;
1371
1372 out:
1373         kfree(buffer.pointer);
1374         return status;
1375 }
1376
1377 static int
1378 acpi_video_get_next_level(struct acpi_video_device *device,
1379                           u32 level_current, u32 event)
1380 {
1381         int min, max, min_above, max_below, i, l, delta = 255;
1382         max = max_below = 0;
1383         min = min_above = 255;
1384         /* Find closest level to level_current */
1385         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1386                 l = device->brightness->levels[i];
1387                 if (abs(l - level_current) < abs(delta)) {
1388                         delta = l - level_current;
1389                         if (!delta)
1390                                 break;
1391                 }
1392         }
1393         /* Ajust level_current to closest available level */
1394         level_current += delta;
1395         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1396                 l = device->brightness->levels[i];
1397                 if (l < min)
1398                         min = l;
1399                 if (l > max)
1400                         max = l;
1401                 if (l < min_above && l > level_current)
1402                         min_above = l;
1403                 if (l > max_below && l < level_current)
1404                         max_below = l;
1405         }
1406
1407         switch (event) {
1408         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1409                 return (level_current < max) ? min_above : min;
1410         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1411                 return (level_current < max) ? min_above : max;
1412         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1413                 return (level_current > min) ? max_below : min;
1414         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1415         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1416                 return 0;
1417         default:
1418                 return level_current;
1419         }
1420 }
1421
1422 static void
1423 acpi_video_switch_brightness(struct work_struct *work)
1424 {
1425         struct acpi_video_device *device = container_of(to_delayed_work(work),
1426                              struct acpi_video_device, switch_brightness_work);
1427         unsigned long long level_current, level_next;
1428         int event = device->switch_brightness_event;
1429         int result = -EINVAL;
1430
1431         /* no warning message if acpi_backlight=vendor or a quirk is used */
1432         if (!device->backlight)
1433                 return;
1434
1435         if (!device->brightness)
1436                 goto out;
1437
1438         result = acpi_video_device_lcd_get_level_current(device,
1439                                                          &level_current,
1440                                                          false);
1441         if (result)
1442                 goto out;
1443
1444         level_next = acpi_video_get_next_level(device, level_current, event);
1445
1446         result = acpi_video_device_lcd_set_level(device, level_next);
1447
1448         if (!result)
1449                 backlight_force_update(device->backlight,
1450                                        BACKLIGHT_UPDATE_HOTKEY);
1451
1452 out:
1453         if (result)
1454                 printk(KERN_ERR PREFIX "Failed to switch the brightness\n");
1455 }
1456
1457 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1458                         void **edid)
1459 {
1460         struct acpi_video_bus *video;
1461         struct acpi_video_device *video_device;
1462         union acpi_object *buffer = NULL;
1463         acpi_status status;
1464         int i, length;
1465
1466         if (!device || !acpi_driver_data(device))
1467                 return -EINVAL;
1468
1469         video = acpi_driver_data(device);
1470
1471         for (i = 0; i < video->attached_count; i++) {
1472                 video_device = video->attached_array[i].bind_info;
1473                 length = 256;
1474
1475                 if (!video_device)
1476                         continue;
1477
1478                 if (!video_device->cap._DDC)
1479                         continue;
1480
1481                 if (type) {
1482                         switch (type) {
1483                         case ACPI_VIDEO_DISPLAY_CRT:
1484                                 if (!video_device->flags.crt)
1485                                         continue;
1486                                 break;
1487                         case ACPI_VIDEO_DISPLAY_TV:
1488                                 if (!video_device->flags.tvout)
1489                                         continue;
1490                                 break;
1491                         case ACPI_VIDEO_DISPLAY_DVI:
1492                                 if (!video_device->flags.dvi)
1493                                         continue;
1494                                 break;
1495                         case ACPI_VIDEO_DISPLAY_LCD:
1496                                 if (!video_device->flags.lcd)
1497                                         continue;
1498                                 break;
1499                         }
1500                 } else if (video_device->device_id != device_id) {
1501                         continue;
1502                 }
1503
1504                 status = acpi_video_device_EDID(video_device, &buffer, length);
1505
1506                 if (ACPI_FAILURE(status) || !buffer ||
1507                     buffer->type != ACPI_TYPE_BUFFER) {
1508                         length = 128;
1509                         status = acpi_video_device_EDID(video_device, &buffer,
1510                                                         length);
1511                         if (ACPI_FAILURE(status) || !buffer ||
1512                             buffer->type != ACPI_TYPE_BUFFER) {
1513                                 continue;
1514                         }
1515                 }
1516
1517                 *edid = buffer->buffer.pointer;
1518                 return length;
1519         }
1520
1521         return -ENODEV;
1522 }
1523 EXPORT_SYMBOL(acpi_video_get_edid);
1524
1525 static int
1526 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1527                            struct acpi_device *device)
1528 {
1529         int status = 0;
1530         struct acpi_device *dev;
1531
1532         /*
1533          * There are systems where video module known to work fine regardless
1534          * of broken _DOD and ignoring returned value here doesn't cause
1535          * any issues later.
1536          */
1537         acpi_video_device_enumerate(video);
1538
1539         list_for_each_entry(dev, &device->children, node) {
1540
1541                 status = acpi_video_bus_get_one_device(dev, video);
1542                 if (status) {
1543                         dev_err(&dev->dev, "Can't attach device\n");
1544                         break;
1545                 }
1546                 video->child_count++;
1547         }
1548         return status;
1549 }
1550
1551 /* acpi_video interface */
1552
1553 /*
1554  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1555  * preform any automatic brightness change on receiving a notification.
1556  */
1557 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1558 {
1559         return acpi_video_bus_DOS(video, 0,
1560                                   acpi_osi_is_win8() ? 1 : 0);
1561 }
1562
1563 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1564 {
1565         return acpi_video_bus_DOS(video, 0,
1566                                   acpi_osi_is_win8() ? 0 : 1);
1567 }
1568
1569 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1570 {
1571         struct acpi_video_bus *video = acpi_driver_data(device);
1572         struct input_dev *input;
1573         int keycode = 0;
1574
1575         if (!video || !video->input)
1576                 return;
1577
1578         input = video->input;
1579
1580         switch (event) {
1581         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1582                                          * most likely via hotkey. */
1583                 keycode = KEY_SWITCHVIDEOMODE;
1584                 break;
1585
1586         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1587                                          * connector. */
1588                 acpi_video_device_enumerate(video);
1589                 acpi_video_device_rebind(video);
1590                 keycode = KEY_SWITCHVIDEOMODE;
1591                 break;
1592
1593         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1594                 keycode = KEY_SWITCHVIDEOMODE;
1595                 break;
1596         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1597                 keycode = KEY_VIDEO_NEXT;
1598                 break;
1599         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1600                 keycode = KEY_VIDEO_PREV;
1601                 break;
1602
1603         default:
1604                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1605                                   "Unsupported event [0x%x]\n", event));
1606                 break;
1607         }
1608
1609         if (acpi_notifier_call_chain(device, event, 0))
1610                 /* Something vetoed the keypress. */
1611                 keycode = 0;
1612
1613         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1614                 input_report_key(input, keycode, 1);
1615                 input_sync(input);
1616                 input_report_key(input, keycode, 0);
1617                 input_sync(input);
1618         }
1619
1620         return;
1621 }
1622
1623 static void brightness_switch_event(struct acpi_video_device *video_device,
1624                                     u32 event)
1625 {
1626         if (!brightness_switch_enabled)
1627                 return;
1628
1629         video_device->switch_brightness_event = event;
1630         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1631 }
1632
1633 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1634 {
1635         struct acpi_video_device *video_device = data;
1636         struct acpi_device *device = NULL;
1637         struct acpi_video_bus *bus;
1638         struct input_dev *input;
1639         int keycode = 0;
1640
1641         if (!video_device)
1642                 return;
1643
1644         device = video_device->dev;
1645         bus = video_device->video;
1646         input = bus->input;
1647
1648         if (hw_changes_brightness > 0) {
1649                 if (video_device->backlight)
1650                         backlight_force_update(video_device->backlight,
1651                                                BACKLIGHT_UPDATE_HOTKEY);
1652                 acpi_notifier_call_chain(device, event, 0);
1653                 return;
1654         }
1655
1656         switch (event) {
1657         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1658                 brightness_switch_event(video_device, event);
1659                 keycode = KEY_BRIGHTNESS_CYCLE;
1660                 break;
1661         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1662                 brightness_switch_event(video_device, event);
1663                 keycode = KEY_BRIGHTNESSUP;
1664                 break;
1665         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1666                 brightness_switch_event(video_device, event);
1667                 keycode = KEY_BRIGHTNESSDOWN;
1668                 break;
1669         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1670                 brightness_switch_event(video_device, event);
1671                 keycode = KEY_BRIGHTNESS_ZERO;
1672                 break;
1673         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1674                 brightness_switch_event(video_device, event);
1675                 keycode = KEY_DISPLAY_OFF;
1676                 break;
1677         default:
1678                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
1679                                   "Unsupported event [0x%x]\n", event));
1680                 break;
1681         }
1682
1683         acpi_notifier_call_chain(device, event, 0);
1684
1685         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1686                 input_report_key(input, keycode, 1);
1687                 input_sync(input);
1688                 input_report_key(input, keycode, 0);
1689                 input_sync(input);
1690         }
1691
1692         return;
1693 }
1694
1695 static int acpi_video_resume(struct notifier_block *nb,
1696                                 unsigned long val, void *ign)
1697 {
1698         struct acpi_video_bus *video;
1699         struct acpi_video_device *video_device;
1700         int i;
1701
1702         switch (val) {
1703         case PM_HIBERNATION_PREPARE:
1704         case PM_SUSPEND_PREPARE:
1705         case PM_RESTORE_PREPARE:
1706                 return NOTIFY_DONE;
1707         }
1708
1709         video = container_of(nb, struct acpi_video_bus, pm_nb);
1710
1711         dev_info(&video->device->dev, "Restoring backlight state\n");
1712
1713         for (i = 0; i < video->attached_count; i++) {
1714                 video_device = video->attached_array[i].bind_info;
1715                 if (video_device && video_device->brightness)
1716                         acpi_video_device_lcd_set_level(video_device,
1717                                         video_device->brightness->curr);
1718         }
1719
1720         return NOTIFY_OK;
1721 }
1722
1723 static acpi_status
1724 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1725                         void **return_value)
1726 {
1727         struct acpi_device *device = context;
1728         struct acpi_device *sibling;
1729         int result;
1730
1731         if (handle == device->handle)
1732                 return AE_CTRL_TERMINATE;
1733
1734         result = acpi_bus_get_device(handle, &sibling);
1735         if (result)
1736                 return AE_OK;
1737
1738         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1739                         return AE_ALREADY_EXISTS;
1740
1741         return AE_OK;
1742 }
1743
1744 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1745 {
1746         struct backlight_properties props;
1747         struct pci_dev *pdev;
1748         acpi_handle acpi_parent;
1749         struct device *parent = NULL;
1750         int result;
1751         static int count;
1752         char *name;
1753
1754         result = acpi_video_init_brightness(device);
1755         if (result)
1756                 return;
1757
1758         if (disable_backlight_sysfs_if > 0)
1759                 return;
1760
1761         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1762         if (!name)
1763                 return;
1764         count++;
1765
1766         acpi_get_parent(device->dev->handle, &acpi_parent);
1767
1768         pdev = acpi_get_pci_dev(acpi_parent);
1769         if (pdev) {
1770                 parent = &pdev->dev;
1771                 pci_dev_put(pdev);
1772         }
1773
1774         memset(&props, 0, sizeof(struct backlight_properties));
1775         props.type = BACKLIGHT_FIRMWARE;
1776         props.max_brightness =
1777                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1778         device->backlight = backlight_device_register(name,
1779                                                       parent,
1780                                                       device,
1781                                                       &acpi_backlight_ops,
1782                                                       &props);
1783         kfree(name);
1784         if (IS_ERR(device->backlight)) {
1785                 device->backlight = NULL;
1786                 return;
1787         }
1788
1789         /*
1790          * Save current brightness level in case we have to restore it
1791          * before acpi_video_device_lcd_set_level() is called next time.
1792          */
1793         device->backlight->props.brightness =
1794                         acpi_video_get_brightness(device->backlight);
1795
1796         device->cooling_dev = thermal_cooling_device_register("LCD",
1797                                 device->dev, &video_cooling_ops);
1798         if (IS_ERR(device->cooling_dev)) {
1799                 /*
1800                  * Set cooling_dev to NULL so we don't crash trying to free it.
1801                  * Also, why the hell we are returning early and not attempt to
1802                  * register video output if cooling device registration failed?
1803                  * -- dtor
1804                  */
1805                 device->cooling_dev = NULL;
1806                 return;
1807         }
1808
1809         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1810                  device->cooling_dev->id);
1811         result = sysfs_create_link(&device->dev->dev.kobj,
1812                         &device->cooling_dev->device.kobj,
1813                         "thermal_cooling");
1814         if (result)
1815                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1816         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1817                         &device->dev->dev.kobj, "device");
1818         if (result)
1819                 printk(KERN_ERR PREFIX "Create sysfs link\n");
1820 }
1821
1822 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1823 {
1824         struct acpi_video_device *dev;
1825         union acpi_object *levels;
1826
1827         mutex_lock(&video->device_list_lock);
1828         list_for_each_entry(dev, &video->video_device_list, entry) {
1829                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1830                         kfree(levels);
1831         }
1832         mutex_unlock(&video->device_list_lock);
1833 }
1834
1835 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1836 {
1837         /*
1838          * Do not create backlight device for video output
1839          * device that is not in the enumerated list.
1840          */
1841         if (!acpi_video_device_in_dod(dev)) {
1842                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1843                 return false;
1844         }
1845
1846         if (only_lcd)
1847                 return dev->flags.lcd;
1848         return true;
1849 }
1850
1851 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1852 {
1853         struct acpi_video_device *dev;
1854
1855         if (video->backlight_registered)
1856                 return 0;
1857
1858         acpi_video_run_bcl_for_osi(video);
1859
1860         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1861                 return 0;
1862
1863         mutex_lock(&video->device_list_lock);
1864         list_for_each_entry(dev, &video->video_device_list, entry) {
1865                 if (acpi_video_should_register_backlight(dev))
1866                         acpi_video_dev_register_backlight(dev);
1867         }
1868         mutex_unlock(&video->device_list_lock);
1869
1870         video->backlight_registered = true;
1871
1872         video->pm_nb.notifier_call = acpi_video_resume;
1873         video->pm_nb.priority = 0;
1874         return register_pm_notifier(&video->pm_nb);
1875 }
1876
1877 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1878 {
1879         if (device->backlight) {
1880                 backlight_device_unregister(device->backlight);
1881                 device->backlight = NULL;
1882         }
1883         if (device->brightness) {
1884                 kfree(device->brightness->levels);
1885                 kfree(device->brightness);
1886                 device->brightness = NULL;
1887         }
1888         if (device->cooling_dev) {
1889                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1890                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1891                 thermal_cooling_device_unregister(device->cooling_dev);
1892                 device->cooling_dev = NULL;
1893         }
1894 }
1895
1896 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1897 {
1898         struct acpi_video_device *dev;
1899         int error;
1900
1901         if (!video->backlight_registered)
1902                 return 0;
1903
1904         error = unregister_pm_notifier(&video->pm_nb);
1905
1906         mutex_lock(&video->device_list_lock);
1907         list_for_each_entry(dev, &video->video_device_list, entry)
1908                 acpi_video_dev_unregister_backlight(dev);
1909         mutex_unlock(&video->device_list_lock);
1910
1911         video->backlight_registered = false;
1912
1913         return error;
1914 }
1915
1916 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1917 {
1918         acpi_status status;
1919         struct acpi_device *adev = device->dev;
1920
1921         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1922                                              acpi_video_device_notify, device);
1923         if (ACPI_FAILURE(status))
1924                 dev_err(&adev->dev, "Error installing notify handler\n");
1925         else
1926                 device->flags.notify = 1;
1927 }
1928
1929 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1930 {
1931         struct input_dev *input;
1932         struct acpi_video_device *dev;
1933         int error;
1934
1935         video->input = input = input_allocate_device();
1936         if (!input) {
1937                 error = -ENOMEM;
1938                 goto out;
1939         }
1940
1941         error = acpi_video_bus_start_devices(video);
1942         if (error)
1943                 goto err_free_input;
1944
1945         snprintf(video->phys, sizeof(video->phys),
1946                         "%s/video/input0", acpi_device_hid(video->device));
1947
1948         input->name = acpi_device_name(video->device);
1949         input->phys = video->phys;
1950         input->id.bustype = BUS_HOST;
1951         input->id.product = 0x06;
1952         input->dev.parent = &video->device->dev;
1953         input->evbit[0] = BIT(EV_KEY);
1954         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1955         set_bit(KEY_VIDEO_NEXT, input->keybit);
1956         set_bit(KEY_VIDEO_PREV, input->keybit);
1957         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1958         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1959         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1960         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1961         set_bit(KEY_DISPLAY_OFF, input->keybit);
1962
1963         error = input_register_device(input);
1964         if (error)
1965                 goto err_stop_dev;
1966
1967         mutex_lock(&video->device_list_lock);
1968         list_for_each_entry(dev, &video->video_device_list, entry)
1969                 acpi_video_dev_add_notify_handler(dev);
1970         mutex_unlock(&video->device_list_lock);
1971
1972         return 0;
1973
1974 err_stop_dev:
1975         acpi_video_bus_stop_devices(video);
1976 err_free_input:
1977         input_free_device(input);
1978         video->input = NULL;
1979 out:
1980         return error;
1981 }
1982
1983 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1984 {
1985         if (dev->flags.notify) {
1986                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
1987                                            acpi_video_device_notify);
1988                 dev->flags.notify = 0;
1989         }
1990 }
1991
1992 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
1993 {
1994         struct acpi_video_device *dev;
1995
1996         mutex_lock(&video->device_list_lock);
1997         list_for_each_entry(dev, &video->video_device_list, entry)
1998                 acpi_video_dev_remove_notify_handler(dev);
1999         mutex_unlock(&video->device_list_lock);
2000
2001         acpi_video_bus_stop_devices(video);
2002         input_unregister_device(video->input);
2003         video->input = NULL;
2004 }
2005
2006 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
2007 {
2008         struct acpi_video_device *dev, *next;
2009
2010         mutex_lock(&video->device_list_lock);
2011         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
2012                 list_del(&dev->entry);
2013                 kfree(dev);
2014         }
2015         mutex_unlock(&video->device_list_lock);
2016
2017         return 0;
2018 }
2019
2020 static int instance;
2021
2022 static int acpi_video_bus_add(struct acpi_device *device)
2023 {
2024         struct acpi_video_bus *video;
2025         int error;
2026         acpi_status status;
2027
2028         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2029                                 device->parent->handle, 1,
2030                                 acpi_video_bus_match, NULL,
2031                                 device, NULL);
2032         if (status == AE_ALREADY_EXISTS) {
2033                 printk(KERN_WARNING FW_BUG
2034                         "Duplicate ACPI video bus devices for the"
2035                         " same VGA controller, please try module "
2036                         "parameter \"video.allow_duplicates=1\""
2037                         "if the current driver doesn't work.\n");
2038                 if (!allow_duplicates)
2039                         return -ENODEV;
2040         }
2041
2042         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2043         if (!video)
2044                 return -ENOMEM;
2045
2046         /* a hack to fix the duplicate name "VID" problem on T61 */
2047         if (!strcmp(device->pnp.bus_id, "VID")) {
2048                 if (instance)
2049                         device->pnp.bus_id[3] = '0' + instance;
2050                 instance++;
2051         }
2052         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2053         if (!strcmp(device->pnp.bus_id, "VGA")) {
2054                 if (instance)
2055                         device->pnp.bus_id[3] = '0' + instance;
2056                 instance++;
2057         }
2058
2059         video->device = device;
2060         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2061         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2062         device->driver_data = video;
2063
2064         acpi_video_bus_find_cap(video);
2065         error = acpi_video_bus_check(video);
2066         if (error)
2067                 goto err_free_video;
2068
2069         mutex_init(&video->device_list_lock);
2070         INIT_LIST_HEAD(&video->video_device_list);
2071
2072         error = acpi_video_bus_get_devices(video, device);
2073         if (error)
2074                 goto err_put_video;
2075
2076         printk(KERN_INFO PREFIX "%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2077                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2078                video->flags.multihead ? "yes" : "no",
2079                video->flags.rom ? "yes" : "no",
2080                video->flags.post ? "yes" : "no");
2081         mutex_lock(&video_list_lock);
2082         list_add_tail(&video->entry, &video_bus_head);
2083         mutex_unlock(&video_list_lock);
2084
2085         acpi_video_bus_register_backlight(video);
2086         acpi_video_bus_add_notify_handler(video);
2087
2088         return 0;
2089
2090 err_put_video:
2091         acpi_video_bus_put_devices(video);
2092         kfree(video->attached_array);
2093 err_free_video:
2094         kfree(video);
2095         device->driver_data = NULL;
2096
2097         return error;
2098 }
2099
2100 static int acpi_video_bus_remove(struct acpi_device *device)
2101 {
2102         struct acpi_video_bus *video = NULL;
2103
2104
2105         if (!device || !acpi_driver_data(device))
2106                 return -EINVAL;
2107
2108         video = acpi_driver_data(device);
2109
2110         acpi_video_bus_remove_notify_handler(video);
2111         acpi_video_bus_unregister_backlight(video);
2112         acpi_video_bus_put_devices(video);
2113
2114         mutex_lock(&video_list_lock);
2115         list_del(&video->entry);
2116         mutex_unlock(&video_list_lock);
2117
2118         kfree(video->attached_array);
2119         kfree(video);
2120
2121         return 0;
2122 }
2123
2124 static int __init is_i740(struct pci_dev *dev)
2125 {
2126         if (dev->device == 0x00D1)
2127                 return 1;
2128         if (dev->device == 0x7000)
2129                 return 1;
2130         return 0;
2131 }
2132
2133 static int __init intel_opregion_present(void)
2134 {
2135         int opregion = 0;
2136         struct pci_dev *dev = NULL;
2137         u32 address;
2138
2139         for_each_pci_dev(dev) {
2140                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2141                         continue;
2142                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2143                         continue;
2144                 /* We don't want to poke around undefined i740 registers */
2145                 if (is_i740(dev))
2146                         continue;
2147                 pci_read_config_dword(dev, 0xfc, &address);
2148                 if (!address)
2149                         continue;
2150                 opregion = 1;
2151         }
2152         return opregion;
2153 }
2154
2155 /* Check if the chassis-type indicates there is no builtin LCD panel */
2156 static bool dmi_is_desktop(void)
2157 {
2158         const char *chassis_type;
2159         unsigned long type;
2160
2161         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2162         if (!chassis_type)
2163                 return false;
2164
2165         if (kstrtoul(chassis_type, 10, &type) != 0)
2166                 return false;
2167
2168         switch (type) {
2169         case 0x03: /* Desktop */
2170         case 0x04: /* Low Profile Desktop */
2171         case 0x05: /* Pizza Box */
2172         case 0x06: /* Mini Tower */
2173         case 0x07: /* Tower */
2174         case 0x10: /* Lunch Box */
2175         case 0x11: /* Main Server Chassis */
2176                 return true;
2177         }
2178
2179         return false;
2180 }
2181
2182 int acpi_video_register(void)
2183 {
2184         int ret = 0;
2185
2186         mutex_lock(&register_count_mutex);
2187         if (register_count) {
2188                 /*
2189                  * if the function of acpi_video_register is already called,
2190                  * don't register the acpi_video_bus again and return no error.
2191                  */
2192                 goto leave;
2193         }
2194
2195         /*
2196          * We're seeing a lot of bogus backlight interfaces on newer machines
2197          * without a LCD such as desktops, servers and HDMI sticks. Checking
2198          * the lcd flag fixes this, so enable this on any machines which are
2199          * win8 ready (where we also prefer the native backlight driver, so
2200          * normally the acpi_video code should not register there anyways).
2201          */
2202         if (only_lcd == -1) {
2203                 if (dmi_is_desktop() && acpi_osi_is_win8())
2204                         only_lcd = true;
2205                 else
2206                         only_lcd = false;
2207         }
2208
2209         dmi_check_system(video_dmi_table);
2210
2211         ret = acpi_bus_register_driver(&acpi_video_bus);
2212         if (ret)
2213                 goto leave;
2214
2215         /*
2216          * When the acpi_video_bus is loaded successfully, increase
2217          * the counter reference.
2218          */
2219         register_count = 1;
2220
2221 leave:
2222         mutex_unlock(&register_count_mutex);
2223         return ret;
2224 }
2225 EXPORT_SYMBOL(acpi_video_register);
2226
2227 void acpi_video_unregister(void)
2228 {
2229         mutex_lock(&register_count_mutex);
2230         if (register_count) {
2231                 acpi_bus_unregister_driver(&acpi_video_bus);
2232                 register_count = 0;
2233         }
2234         mutex_unlock(&register_count_mutex);
2235 }
2236 EXPORT_SYMBOL(acpi_video_unregister);
2237
2238 void acpi_video_unregister_backlight(void)
2239 {
2240         struct acpi_video_bus *video;
2241
2242         mutex_lock(&register_count_mutex);
2243         if (register_count) {
2244                 mutex_lock(&video_list_lock);
2245                 list_for_each_entry(video, &video_bus_head, entry)
2246                         acpi_video_bus_unregister_backlight(video);
2247                 mutex_unlock(&video_list_lock);
2248         }
2249         mutex_unlock(&register_count_mutex);
2250 }
2251
2252 bool acpi_video_handles_brightness_key_presses(void)
2253 {
2254         bool have_video_busses;
2255
2256         mutex_lock(&video_list_lock);
2257         have_video_busses = !list_empty(&video_bus_head);
2258         mutex_unlock(&video_list_lock);
2259
2260         return have_video_busses &&
2261                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2262 }
2263 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2264
2265 /*
2266  * This is kind of nasty. Hardware using Intel chipsets may require
2267  * the video opregion code to be run first in order to initialise
2268  * state before any ACPI video calls are made. To handle this we defer
2269  * registration of the video class until the opregion code has run.
2270  */
2271
2272 static int __init acpi_video_init(void)
2273 {
2274         /*
2275          * Let the module load even if ACPI is disabled (e.g. due to
2276          * a broken BIOS) so that i915.ko can still be loaded on such
2277          * old systems without an AcpiOpRegion.
2278          *
2279          * acpi_video_register() will report -ENODEV later as well due
2280          * to acpi_disabled when i915.ko tries to register itself afterwards.
2281          */
2282         if (acpi_disabled)
2283                 return 0;
2284
2285         if (intel_opregion_present())
2286                 return 0;
2287
2288         return acpi_video_register();
2289 }
2290
2291 static void __exit acpi_video_exit(void)
2292 {
2293         acpi_video_detect_exit();
2294         acpi_video_unregister();
2295
2296         return;
2297 }
2298
2299 module_init(acpi_video_init);
2300 module_exit(acpi_video_exit);