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          * Some machine's _DOD IDs don't have bit 31(Device ID Scheme) set
 501          * but the IDs actually follow the Device ID Scheme.
 502          */
 503         {
 504          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 505          .callback = video_set_device_id_scheme,
 506          .ident = "ESPRIMO Mobile M9410",
 507          .matches = {
 508                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 509                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 510                 },
 511         },
 512         /*
 513          * Some machines have multiple video output devices, but only the one
 514          * that is the type of LCD can do the backlight control so we should not
 515          * register backlight interface for other video output devices.
 516          */
 517         {
 518          /* https://bugzilla.kernel.org/show_bug.cgi?id=104121 */
 519          .callback = video_enable_only_lcd,
 520          .ident = "ESPRIMO Mobile M9410",
 521          .matches = {
 522                 DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 523                 DMI_MATCH(DMI_PRODUCT_NAME, "ESPRIMO Mobile M9410"),
 524                 },
 525         },
 526         /*
 527          * Some machines report wrong key events on the acpi-bus, suppress
 528          * key event reporting on these.  Note this is only intended to work
 529          * around events which are plain wrong. In some cases we get double
 530          * events, in this case acpi-video is considered the canonical source
 531          * and the events from the other source should be filtered. E.g.
 532          * by calling acpi_video_handles_brightness_key_presses() from the
 533          * vendor acpi/wmi driver or by using /lib/udev/hwdb.d/60-keyboard.hwdb
 534          */
 535         {
 536          .callback = video_set_report_key_events,
 537          .driver_data = (void *)((uintptr_t)REPORT_OUTPUT_KEY_EVENTS),
 538          .ident = "Dell Vostro V131",
 539          .matches = {
 540                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 541                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro V131"),
 542                 },
 543         },
 544         {
 545          .callback = video_set_report_key_events,
 546          .driver_data = (void *)((uintptr_t)REPORT_BRIGHTNESS_KEY_EVENTS),
 547          .ident = "Dell Vostro 3350",
 548          .matches = {
 549                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 550                 DMI_MATCH(DMI_PRODUCT_NAME, "Vostro 3350"),
 551                 },
 552         },
 553         /*
 554          * Some machines change the brightness themselves when a brightness
 555          * hotkey gets pressed, despite us telling them not to. In this case
 556          * acpi_video_device_notify() should only call backlight_force_update(
 557          * BACKLIGHT_UPDATE_HOTKEY) and not do anything else.
 558          */
 559         {
 560          /* https://bugzilla.kernel.org/show_bug.cgi?id=204077 */
 561          .callback = video_hw_changes_brightness,
 562          .ident = "Packard Bell EasyNote MZ35",
 563          .matches = {
 564                 DMI_MATCH(DMI_SYS_VENDOR, "Packard Bell"),
 565                 DMI_MATCH(DMI_PRODUCT_NAME, "EasyNote MZ35"),
 566                 },
 567         },
 568         {}
 569 };
 570
 571 static unsigned long long
 572 acpi_video_bqc_value_to_level(struct acpi_video_device *device,
 573                               unsigned long long bqc_value)
 574 {
 575         unsigned long long level;
 576
 577         if (device->brightness->flags._BQC_use_index) {
 578                 /*
 579                  * _BQC returns an index that doesn't account for the first 2
 580                  * items with special meaning (see enum acpi_video_level_idx),
 581                  * so we need to compensate for that by offsetting ourselves
 582                  */
 583                 if (device->brightness->flags._BCL_reversed)
 584                         bqc_value = device->brightness->count -
 585                                 ACPI_VIDEO_FIRST_LEVEL - 1 - bqc_value;
 586
 587                 level = device->brightness->levels[bqc_value +
 588                                                    ACPI_VIDEO_FIRST_LEVEL];
 589         } else {
 590                 level = bqc_value;
 591         }
 592
 593         level += bqc_offset_aml_bug_workaround;
 594
 595         return level;
 596 }
 597
 598 static int
 599 acpi_video_device_lcd_get_level_current(struct acpi_video_device *device,
 600                                         unsigned long long *level, bool raw)
 601 {
 602         acpi_status status = AE_OK;
 603         int i;
 604
 605         if (device->cap._BQC || device->cap._BCQ) {
 606                 char *buf = device->cap._BQC ? "_BQC" : "_BCQ";
 607
 608                 status = acpi_evaluate_integer(device->dev->handle, buf,
 609                                                 NULL, level);
 610                 if (ACPI_SUCCESS(status)) {
 611                         if (raw) {
 612                                 /*
 613                                  * Caller has indicated he wants the raw
 614                                  * value returned by _BQC, so don't furtherly
 615                                  * mess with the value.
 616                                  */
 617                                 return 0;
 618                         }
 619
 620                         *level = acpi_video_bqc_value_to_level(device, *level);
 621
 622                         for (i = ACPI_VIDEO_FIRST_LEVEL;
 623                              i < device->brightness->count; i++)
 624                                 if (device->brightness->levels[i] == *level) {
 625                                         device->brightness->curr = *level;
 626                                         return 0;
 627                                 }
 628                         /*
 629                          * BQC returned an invalid level.
 630                          * Stop using it.
 631                          */
 632                         acpi_handle_info(device->dev->handle,
 633                                          "%s returned an invalid level", buf);
 634                         device->cap._BQC = device->cap._BCQ = 0;
 635                 } else {
 636                         /*
 637                          * Fixme:
 638                          * should we return an error or ignore this failure?
 639                          * dev->brightness->curr is a cached value which stores
 640                          * the correct current backlight level in most cases.
 641                          * ACPI video backlight still works w/ buggy _BQC.
 642                          * http://bugzilla.kernel.org/show_bug.cgi?id=12233
 643                          */
 644                         acpi_handle_info(device->dev->handle,
 645                                          "%s evaluation failed", buf);
 646                         device->cap._BQC = device->cap._BCQ = 0;
 647                 }
 648         }
 649
 650         *level = device->brightness->curr;
 651         return 0;
 652 }
 653
 654 static int
 655 acpi_video_device_EDID(struct acpi_video_device *device,
 656                        union acpi_object **edid, ssize_t length)
 657 {
 658         int status;
 659         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 660         union acpi_object *obj;
 661         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
 662         struct acpi_object_list args = { 1, &arg0 };
 663
 664
 665         *edid = NULL;
 666
 667         if (!device)
 668                 return -ENODEV;
 669         if (length == 128)
 670                 arg0.integer.value = 1;
 671         else if (length == 256)
 672                 arg0.integer.value = 2;
 673         else
 674                 return -EINVAL;
 675
 676         status = acpi_evaluate_object(device->dev->handle, "_DDC", &args, &buffer);
 677         if (ACPI_FAILURE(status))
 678                 return -ENODEV;
 679
 680         obj = buffer.pointer;
 681
 682         if (obj && obj->type == ACPI_TYPE_BUFFER)
 683                 *edid = obj;
 684         else {
 685                 acpi_handle_info(device->dev->handle, "Invalid _DDC data\n");
 686                 status = -EFAULT;
 687                 kfree(obj);
 688         }
 689
 690         return status;
 691 }
 692
 693 /* bus */
 694
 695 /*
 696  *  Arg:
 697  *      video           : video bus device pointer
 698  *      bios_flag       :
 699  *              0.      The system BIOS should NOT automatically switch(toggle)
 700  *                      the active display output.
 701  *              1.      The system BIOS should automatically switch (toggle) the
 702  *                      active display output. No switch event.
 703  *              2.      The _DGS value should be locked.
 704  *              3.      The system BIOS should not automatically switch (toggle) the
 705  *                      active display output, but instead generate the display switch
 706  *                      event notify code.
 707  *      lcd_flag        :
 708  *              0.      The system BIOS should automatically control the brightness level
 709  *                      of the LCD when:
 710  *                      - the power changes from AC to DC (ACPI appendix B)
 711  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 712  *              1.      The system BIOS should NOT automatically control the brightness
 713  *                      level of the LCD when:
 714  *                      - the power changes from AC to DC (ACPI appendix B)
 715  *                      - a brightness hotkey gets pressed (implied by Win7/8 backlight docs)
 716  *  Return Value:
 717  *              -EINVAL wrong arg.
 718  */
 719
 720 static int
 721 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 722 {
 723         acpi_status status;
 724
 725         if (!video->cap._DOS)
 726                 return 0;
 727
 728         if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
 729                 return -EINVAL;
 730         video->dos_setting = (lcd_flag << 2) | bios_flag;
 731         status = acpi_execute_simple_method(video->device->handle, "_DOS",
 732                                             (lcd_flag << 2) | bios_flag);
 733         if (ACPI_FAILURE(status))
 734                 return -EIO;
 735
 736         return 0;
 737 }
 738
 739 /*
 740  * Simple comparison function used to sort backlight levels.
 741  */
 742
 743 static int
 744 acpi_video_cmp_level(const void *a, const void *b)
 745 {
 746         return *(int *)a - *(int *)b;
 747 }
 748
 749 /*
 750  * Decides if _BQC/_BCQ for this system is usable
 751  *
 752  * We do this by changing the level first and then read out the current
 753  * brightness level, if the value does not match, find out if it is using
 754  * index. If not, clear the _BQC/_BCQ capability.
 755  */
 756 static int acpi_video_bqc_quirk(struct acpi_video_device *device,
 757                                 int max_level, int current_level)
 758 {
 759         struct acpi_video_device_brightness *br = device->brightness;
 760         int result;
 761         unsigned long long level;
 762         int test_level;
 763
 764         /* don't mess with existing known broken systems */
 765         if (bqc_offset_aml_bug_workaround)
 766                 return 0;
 767
 768         /*
 769          * Some systems always report current brightness level as maximum
 770          * through _BQC, we need to test another value for them. However,
 771          * there is a subtlety:
 772          *
 773          * If the _BCL package ordering is descending, the first level
 774          * (br->levels[2]) is likely to be 0, and if the number of levels
 775          * matches the number of steps, we might confuse a returned level to
 776          * mean the index.
 777          *
 778          * For example:
 779          *
 780          *     current_level = max_level = 100
 781          *     test_level = 0
 782          *     returned level = 100
 783          *
 784          * In this case 100 means the level, not the index, and _BCM failed.
 785          * Still, if the _BCL package ordering is descending, the index of
 786          * level 0 is also 100, so we assume _BQC is indexed, when it's not.
 787          *
 788          * This causes all _BQC calls to return bogus values causing weird
 789          * behavior from the user's perspective.  For example:
 790          *
 791          * xbacklight -set 10; xbacklight -set 20;
 792          *
 793          * would flash to 90% and then slowly down to the desired level (20).
 794          *
 795          * The solution is simple; test anything other than the first level
 796          * (e.g. 1).
 797          */
 798         test_level = current_level == max_level
 799                 ? br->levels[ACPI_VIDEO_FIRST_LEVEL + 1]
 800                 : max_level;
 801
 802         result = acpi_video_device_lcd_set_level(device, test_level);
 803         if (result)
 804                 return result;
 805
 806         result = acpi_video_device_lcd_get_level_current(device, &level, true);
 807         if (result)
 808                 return result;
 809
 810         if (level != test_level) {
 811                 /* buggy _BQC found, need to find out if it uses index */
 812                 if (level < br->count) {
 813                         if (br->flags._BCL_reversed)
 814                                 level = br->count - ACPI_VIDEO_FIRST_LEVEL - 1 - level;
 815                         if (br->levels[level + ACPI_VIDEO_FIRST_LEVEL] == test_level)
 816                                 br->flags._BQC_use_index = 1;
 817                 }
 818
 819                 if (!br->flags._BQC_use_index)
 820                         device->cap._BQC = device->cap._BCQ = 0;
 821         }
 822
 823         return 0;
 824 }
 825
 826 int acpi_video_get_levels(struct acpi_device *device,
 827                           struct acpi_video_device_brightness **dev_br,
 828                           int *pmax_level)
 829 {
 830         union acpi_object *obj = NULL;
 831         int i, max_level = 0, count = 0, level_ac_battery = 0;
 832         union acpi_object *o;
 833         struct acpi_video_device_brightness *br = NULL;
 834         int result = 0;
 835         u32 value;
 836
 837         if (ACPI_FAILURE(acpi_video_device_lcd_query_levels(device->handle, &obj))) {
 838                 acpi_handle_debug(device->handle,
 839                                   "Could not query available LCD brightness level\n");
 840                 result = -ENODEV;
 841                 goto out;
 842         }
 843
 844         if (obj->package.count < ACPI_VIDEO_FIRST_LEVEL) {
 845                 result = -EINVAL;
 846                 goto out;
 847         }
 848
 849         br = kzalloc(sizeof(*br), GFP_KERNEL);
 850         if (!br) {
 851                 result = -ENOMEM;
 852                 goto out;
 853         }
 854
 855         /*
 856          * Note that we have to reserve 2 extra items (ACPI_VIDEO_FIRST_LEVEL),
 857          * in order to account for buggy BIOS which don't export the first two
 858          * special levels (see below)
 859          */
 860         br->levels = kmalloc_array(obj->package.count + ACPI_VIDEO_FIRST_LEVEL,
 861                                    sizeof(*br->levels),
 862                                    GFP_KERNEL);
 863         if (!br->levels) {
 864                 result = -ENOMEM;
 865                 goto out_free;
 866         }
 867
 868         for (i = 0; i < obj->package.count; i++) {
 869                 o = (union acpi_object *)&obj->package.elements[i];
 870                 if (o->type != ACPI_TYPE_INTEGER) {
 871                         acpi_handle_info(device->handle, "Invalid data\n");
 872                         continue;
 873                 }
 874                 value = (u32) o->integer.value;
 875                 /* Skip duplicate entries */
 876                 if (count > ACPI_VIDEO_FIRST_LEVEL
 877                     && br->levels[count - 1] == value)
 878                         continue;
 879
 880                 br->levels[count] = value;
 881
 882                 if (br->levels[count] > max_level)
 883                         max_level = br->levels[count];
 884                 count++;
 885         }
 886
 887         /*
 888          * some buggy BIOS don't export the levels
 889          * when machine is on AC/Battery in _BCL package.
 890          * In this case, the first two elements in _BCL packages
 891          * are also supported brightness levels that OS should take care of.
 892          */
 893         for (i = ACPI_VIDEO_FIRST_LEVEL; i < count; i++) {
 894                 if (br->levels[i] == br->levels[ACPI_VIDEO_AC_LEVEL])
 895                         level_ac_battery++;
 896                 if (br->levels[i] == br->levels[ACPI_VIDEO_BATTERY_LEVEL])
 897                         level_ac_battery++;
 898         }
 899
 900         if (level_ac_battery < ACPI_VIDEO_FIRST_LEVEL) {
 901                 level_ac_battery = ACPI_VIDEO_FIRST_LEVEL - level_ac_battery;
 902                 br->flags._BCL_no_ac_battery_levels = 1;
 903                 for (i = (count - 1 + level_ac_battery);
 904                      i >= ACPI_VIDEO_FIRST_LEVEL; i--)
 905                         br->levels[i] = br->levels[i - level_ac_battery];
 906                 count += level_ac_battery;
 907         } else if (level_ac_battery > ACPI_VIDEO_FIRST_LEVEL)
 908                 acpi_handle_info(device->handle,
 909                                  "Too many duplicates in _BCL package");
 910
 911         /* Check if the _BCL package is in a reversed order */
 912         if (max_level == br->levels[ACPI_VIDEO_FIRST_LEVEL]) {
 913                 br->flags._BCL_reversed = 1;
 914                 sort(&br->levels[ACPI_VIDEO_FIRST_LEVEL],
 915                      count - ACPI_VIDEO_FIRST_LEVEL,
 916                      sizeof(br->levels[ACPI_VIDEO_FIRST_LEVEL]),
 917                      acpi_video_cmp_level, NULL);
 918         } else if (max_level != br->levels[count - 1])
 919                 acpi_handle_info(device->handle,
 920                                  "Found unordered _BCL package");
 921
 922         br->count = count;
 923         *dev_br = br;
 924         if (pmax_level)
 925                 *pmax_level = max_level;
 926
 927 out:
 928         kfree(obj);
 929         return result;
 930 out_free:
 931         kfree(br);
 932         goto out;
 933 }
 934 EXPORT_SYMBOL(acpi_video_get_levels);
 935
 936 /*
 937  *  Arg:
 938  *      device  : video output device (LCD, CRT, ..)
 939  *
 940  *  Return Value:
 941  *      Maximum brightness level
 942  *
 943  *  Allocate and initialize device->brightness.
 944  */
 945
 946 static int
 947 acpi_video_init_brightness(struct acpi_video_device *device)
 948 {
 949         int i, max_level = 0;
 950         unsigned long long level, level_old;
 951         struct acpi_video_device_brightness *br = NULL;
 952         int result;
 953
 954         result = acpi_video_get_levels(device->dev, &br, &max_level);
 955         if (result)
 956                 return result;
 957         device->brightness = br;
 958
 959         /* _BQC uses INDEX while _BCL uses VALUE in some laptops */
 960         br->curr = level = max_level;
 961
 962         if (!device->cap._BQC)
 963                 goto set_level;
 964
 965         result = acpi_video_device_lcd_get_level_current(device,
 966                                                          &level_old, true);
 967         if (result)
 968                 goto out_free_levels;
 969
 970         result = acpi_video_bqc_quirk(device, max_level, level_old);
 971         if (result)
 972                 goto out_free_levels;
 973         /*
 974          * cap._BQC may get cleared due to _BQC is found to be broken
 975          * in acpi_video_bqc_quirk, so check again here.
 976          */
 977         if (!device->cap._BQC)
 978                 goto set_level;
 979
 980         level = acpi_video_bqc_value_to_level(device, level_old);
 981         /*
 982          * On some buggy laptops, _BQC returns an uninitialized
 983          * value when invoked for the first time, i.e.
 984          * level_old is invalid (no matter whether it's a level
 985          * or an index). Set the backlight to max_level in this case.
 986          */
 987         for (i = ACPI_VIDEO_FIRST_LEVEL; i < br->count; i++)
 988                 if (level == br->levels[i])
 989                         break;
 990         if (i == br->count || !level)
 991                 level = max_level;
 992
 993 set_level:
 994         result = acpi_video_device_lcd_set_level(device, level);
 995         if (result)
 996                 goto out_free_levels;
 997
 998         acpi_handle_debug(device->dev->handle, "found %d brightness levels\n",
 999                           br->count - ACPI_VIDEO_FIRST_LEVEL);
1000
1001         return 0;
1002
1003 out_free_levels:
1004         kfree(br->levels);
1005         kfree(br);
1006         device->brightness = NULL;
1007         return result;
1008 }
1009
1010 /*
1011  *  Arg:
1012  *      device  : video output device (LCD, CRT, ..)
1013  *
1014  *  Return Value:
1015  *      None
1016  *
1017  *  Find out all required AML methods defined under the output
1018  *  device.
1019  */
1020
1021 static void acpi_video_device_find_cap(struct acpi_video_device *device)
1022 {
1023         if (acpi_has_method(device->dev->handle, "_ADR"))
1024                 device->cap._ADR = 1;
1025         if (acpi_has_method(device->dev->handle, "_BCL"))
1026                 device->cap._BCL = 1;
1027         if (acpi_has_method(device->dev->handle, "_BCM"))
1028                 device->cap._BCM = 1;
1029         if (acpi_has_method(device->dev->handle, "_BQC")) {
1030                 device->cap._BQC = 1;
1031         } else if (acpi_has_method(device->dev->handle, "_BCQ")) {
1032                 acpi_handle_info(device->dev->handle,
1033                                  "_BCQ is used instead of _BQC\n");
1034                 device->cap._BCQ = 1;
1035         }
1036
1037         if (acpi_has_method(device->dev->handle, "_DDC"))
1038                 device->cap._DDC = 1;
1039 }
1040
1041 /*
1042  *  Arg:
1043  *      device  : video output device (VGA)
1044  *
1045  *  Return Value:
1046  *      None
1047  *
1048  *  Find out all required AML methods defined under the video bus device.
1049  */
1050
1051 static void acpi_video_bus_find_cap(struct acpi_video_bus *video)
1052 {
1053         if (acpi_has_method(video->device->handle, "_DOS"))
1054                 video->cap._DOS = 1;
1055         if (acpi_has_method(video->device->handle, "_DOD"))
1056                 video->cap._DOD = 1;
1057         if (acpi_has_method(video->device->handle, "_ROM"))
1058                 video->cap._ROM = 1;
1059         if (acpi_has_method(video->device->handle, "_GPD"))
1060                 video->cap._GPD = 1;
1061         if (acpi_has_method(video->device->handle, "_SPD"))
1062                 video->cap._SPD = 1;
1063         if (acpi_has_method(video->device->handle, "_VPO"))
1064                 video->cap._VPO = 1;
1065 }
1066
1067 /*
1068  * Check whether the video bus device has required AML method to
1069  * support the desired features
1070  */
1071
1072 static int acpi_video_bus_check(struct acpi_video_bus *video)
1073 {
1074         acpi_status status = -ENOENT;
1075         struct pci_dev *dev;
1076
1077         if (!video)
1078                 return -EINVAL;
1079
1080         dev = acpi_get_pci_dev(video->device->handle);
1081         if (!dev)
1082                 return -ENODEV;
1083         pci_dev_put(dev);
1084
1085         /*
1086          * Since there is no HID, CID and so on for VGA driver, we have
1087          * to check well known required nodes.
1088          */
1089
1090         /* Does this device support video switching? */
1091         if (video->cap._DOS || video->cap._DOD) {
1092                 if (!video->cap._DOS) {
1093                         pr_info(FW_BUG "ACPI(%s) defines _DOD but not _DOS\n",
1094                                 acpi_device_bid(video->device));
1095                 }
1096                 video->flags.multihead = 1;
1097                 status = 0;
1098         }
1099
1100         /* Does this device support retrieving a video ROM? */
1101         if (video->cap._ROM) {
1102                 video->flags.rom = 1;
1103                 status = 0;
1104         }
1105
1106         /* Does this device support configuring which video device to POST? */
1107         if (video->cap._GPD && video->cap._SPD && video->cap._VPO) {
1108                 video->flags.post = 1;
1109                 status = 0;
1110         }
1111
1112         return status;
1113 }
1114
1115 /*
1116  * --------------------------------------------------------------------------
1117  *                               Driver Interface
1118  * --------------------------------------------------------------------------
1119  */
1120
1121 /* device interface */
1122 static struct acpi_video_device_attrib *
1123 acpi_video_get_device_attr(struct acpi_video_bus *video, unsigned long device_id)
1124 {
1125         struct acpi_video_enumerated_device *ids;
1126         int i;
1127
1128         for (i = 0; i < video->attached_count; i++) {
1129                 ids = &video->attached_array[i];
1130                 if ((ids->value.int_val & 0xffff) == device_id)
1131                         return &ids->value.attrib;
1132         }
1133
1134         return NULL;
1135 }
1136
1137 static int
1138 acpi_video_get_device_type(struct acpi_video_bus *video,
1139                            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.int_val;
1148         }
1149
1150         return 0;
1151 }
1152
1153 static int
1154 acpi_video_bus_get_one_device(struct acpi_device *device,
1155                               struct acpi_video_bus *video)
1156 {
1157         unsigned long long device_id;
1158         int status, device_type;
1159         struct acpi_video_device *data;
1160         struct acpi_video_device_attrib *attribute;
1161
1162         status =
1163             acpi_evaluate_integer(device->handle, "_ADR", NULL, &device_id);
1164         /* Some device omits _ADR, we skip them instead of fail */
1165         if (ACPI_FAILURE(status))
1166                 return 0;
1167
1168         data = kzalloc(sizeof(struct acpi_video_device), GFP_KERNEL);
1169         if (!data)
1170                 return -ENOMEM;
1171
1172         strcpy(acpi_device_name(device), ACPI_VIDEO_DEVICE_NAME);
1173         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
1174         device->driver_data = data;
1175
1176         data->device_id = device_id;
1177         data->video = video;
1178         data->dev = device;
1179         INIT_DELAYED_WORK(&data->switch_brightness_work,
1180                           acpi_video_switch_brightness);
1181
1182         attribute = acpi_video_get_device_attr(video, device_id);
1183
1184         if (attribute && (attribute->device_id_scheme || device_id_scheme)) {
1185                 switch (attribute->display_type) {
1186                 case ACPI_VIDEO_DISPLAY_CRT:
1187                         data->flags.crt = 1;
1188                         break;
1189                 case ACPI_VIDEO_DISPLAY_TV:
1190                         data->flags.tvout = 1;
1191                         break;
1192                 case ACPI_VIDEO_DISPLAY_DVI:
1193                         data->flags.dvi = 1;
1194                         break;
1195                 case ACPI_VIDEO_DISPLAY_LCD:
1196                         data->flags.lcd = 1;
1197                         break;
1198                 default:
1199                         data->flags.unknown = 1;
1200                         break;
1201                 }
1202                 if (attribute->bios_can_detect)
1203                         data->flags.bios = 1;
1204         } else {
1205                 /* Check for legacy IDs */
1206                 device_type = acpi_video_get_device_type(video, device_id);
1207                 /* Ignore bits 16 and 18-20 */
1208                 switch (device_type & 0xffe2ffff) {
1209                 case ACPI_VIDEO_DISPLAY_LEGACY_MONITOR:
1210                         data->flags.crt = 1;
1211                         break;
1212                 case ACPI_VIDEO_DISPLAY_LEGACY_PANEL:
1213                         data->flags.lcd = 1;
1214                         break;
1215                 case ACPI_VIDEO_DISPLAY_LEGACY_TV:
1216                         data->flags.tvout = 1;
1217                         break;
1218                 default:
1219                         data->flags.unknown = 1;
1220                 }
1221         }
1222
1223         acpi_video_device_bind(video, data);
1224         acpi_video_device_find_cap(data);
1225
1226         if (data->cap._BCM && data->cap._BCL)
1227                 may_report_brightness_keys = true;
1228
1229         mutex_lock(&video->device_list_lock);
1230         list_add_tail(&data->entry, &video->video_device_list);
1231         mutex_unlock(&video->device_list_lock);
1232
1233         return status;
1234 }
1235
1236 /*
1237  *  Arg:
1238  *      video   : video bus device
1239  *
1240  *  Return:
1241  *      none
1242  *
1243  *  Enumerate the video device list of the video bus,
1244  *  bind the ids with the corresponding video devices
1245  *  under the video bus.
1246  */
1247
1248 static void acpi_video_device_rebind(struct acpi_video_bus *video)
1249 {
1250         struct acpi_video_device *dev;
1251
1252         mutex_lock(&video->device_list_lock);
1253
1254         list_for_each_entry(dev, &video->video_device_list, entry)
1255                 acpi_video_device_bind(video, dev);
1256
1257         mutex_unlock(&video->device_list_lock);
1258 }
1259
1260 /*
1261  *  Arg:
1262  *      video   : video bus device
1263  *      device  : video output device under the video
1264  *              bus
1265  *
1266  *  Return:
1267  *      none
1268  *
1269  *  Bind the ids with the corresponding video devices
1270  *  under the video bus.
1271  */
1272
1273 static void
1274 acpi_video_device_bind(struct acpi_video_bus *video,
1275                        struct acpi_video_device *device)
1276 {
1277         struct acpi_video_enumerated_device *ids;
1278         int i;
1279
1280         for (i = 0; i < video->attached_count; i++) {
1281                 ids = &video->attached_array[i];
1282                 if (device->device_id == (ids->value.int_val & 0xffff)) {
1283                         ids->bind_info = device;
1284                         acpi_handle_debug(video->device->handle, "%s: %d\n",
1285                                           __func__, i);
1286                 }
1287         }
1288 }
1289
1290 static bool acpi_video_device_in_dod(struct acpi_video_device *device)
1291 {
1292         struct acpi_video_bus *video = device->video;
1293         int i;
1294
1295         /*
1296          * If we have a broken _DOD or we have more than 8 output devices
1297          * under the graphics controller node that we can't proper deal with
1298          * in the operation region code currently, no need to test.
1299          */
1300         if (!video->attached_count || video->child_count > 8)
1301                 return true;
1302
1303         for (i = 0; i < video->attached_count; i++) {
1304                 if ((video->attached_array[i].value.int_val & 0xfff) ==
1305                     (device->device_id & 0xfff))
1306                         return true;
1307         }
1308
1309         return false;
1310 }
1311
1312 /*
1313  *  Arg:
1314  *      video   : video bus device
1315  *
1316  *  Return:
1317  *      < 0     : error
1318  *
1319  *  Call _DOD to enumerate all devices attached to display adapter
1320  *
1321  */
1322
1323 static int acpi_video_device_enumerate(struct acpi_video_bus *video)
1324 {
1325         int status;
1326         int count;
1327         int i;
1328         struct acpi_video_enumerated_device *active_list;
1329         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
1330         union acpi_object *dod = NULL;
1331         union acpi_object *obj;
1332
1333         if (!video->cap._DOD)
1334                 return AE_NOT_EXIST;
1335
1336         status = acpi_evaluate_object(video->device->handle, "_DOD", NULL, &buffer);
1337         if (ACPI_FAILURE(status)) {
1338                 acpi_handle_info(video->device->handle,
1339                                  "_DOD evaluation failed: %s\n",
1340                                  acpi_format_exception(status));
1341                 return status;
1342         }
1343
1344         dod = buffer.pointer;
1345         if (!dod || (dod->type != ACPI_TYPE_PACKAGE)) {
1346                 acpi_handle_info(video->device->handle, "Invalid _DOD data\n");
1347                 status = -EFAULT;
1348                 goto out;
1349         }
1350
1351         acpi_handle_debug(video->device->handle, "Found %d video heads in _DOD\n",
1352                           dod->package.count);
1353
1354         active_list = kcalloc(1 + dod->package.count,
1355                               sizeof(struct acpi_video_enumerated_device),
1356                               GFP_KERNEL);
1357         if (!active_list) {
1358                 status = -ENOMEM;
1359                 goto out;
1360         }
1361
1362         count = 0;
1363         for (i = 0; i < dod->package.count; i++) {
1364                 obj = &dod->package.elements[i];
1365
1366                 if (obj->type != ACPI_TYPE_INTEGER) {
1367                         acpi_handle_info(video->device->handle,
1368                                          "Invalid _DOD data in element %d\n", i);
1369                         continue;
1370                 }
1371
1372                 active_list[count].value.int_val = obj->integer.value;
1373                 active_list[count].bind_info = NULL;
1374
1375                 acpi_handle_debug(video->device->handle,
1376                                   "_DOD element[%d] = %d\n", i,
1377                                   (int)obj->integer.value);
1378
1379                 count++;
1380         }
1381
1382         kfree(video->attached_array);
1383
1384         video->attached_array = active_list;
1385         video->attached_count = count;
1386
1387 out:
1388         kfree(buffer.pointer);
1389         return status;
1390 }
1391
1392 static int
1393 acpi_video_get_next_level(struct acpi_video_device *device,
1394                           u32 level_current, u32 event)
1395 {
1396         int min, max, min_above, max_below, i, l, delta = 255;
1397         max = max_below = 0;
1398         min = min_above = 255;
1399         /* Find closest level to level_current */
1400         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1401                 l = device->brightness->levels[i];
1402                 if (abs(l - level_current) < abs(delta)) {
1403                         delta = l - level_current;
1404                         if (!delta)
1405                                 break;
1406                 }
1407         }
1408         /* Adjust level_current to closest available level */
1409         level_current += delta;
1410         for (i = ACPI_VIDEO_FIRST_LEVEL; i < device->brightness->count; i++) {
1411                 l = device->brightness->levels[i];
1412                 if (l < min)
1413                         min = l;
1414                 if (l > max)
1415                         max = l;
1416                 if (l < min_above && l > level_current)
1417                         min_above = l;
1418                 if (l > max_below && l < level_current)
1419                         max_below = l;
1420         }
1421
1422         switch (event) {
1423         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:
1424                 return (level_current < max) ? min_above : min;
1425         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:
1426                 return (level_current < max) ? min_above : max;
1427         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:
1428                 return (level_current > min) ? max_below : min;
1429         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:
1430         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:
1431                 return 0;
1432         default:
1433                 return level_current;
1434         }
1435 }
1436
1437 static void
1438 acpi_video_switch_brightness(struct work_struct *work)
1439 {
1440         struct acpi_video_device *device = container_of(to_delayed_work(work),
1441                              struct acpi_video_device, switch_brightness_work);
1442         unsigned long long level_current, level_next;
1443         int event = device->switch_brightness_event;
1444         int result = -EINVAL;
1445
1446         /* no warning message if acpi_backlight=vendor or a quirk is used */
1447         if (!device->backlight)
1448                 return;
1449
1450         if (!device->brightness)
1451                 goto out;
1452
1453         result = acpi_video_device_lcd_get_level_current(device,
1454                                                          &level_current,
1455                                                          false);
1456         if (result)
1457                 goto out;
1458
1459         level_next = acpi_video_get_next_level(device, level_current, event);
1460
1461         result = acpi_video_device_lcd_set_level(device, level_next);
1462
1463         if (!result)
1464                 backlight_force_update(device->backlight,
1465                                        BACKLIGHT_UPDATE_HOTKEY);
1466
1467 out:
1468         if (result)
1469                 acpi_handle_info(device->dev->handle,
1470                                  "Failed to switch brightness\n");
1471 }
1472
1473 int acpi_video_get_edid(struct acpi_device *device, int type, int device_id,
1474                         void **edid)
1475 {
1476         struct acpi_video_bus *video;
1477         struct acpi_video_device *video_device;
1478         union acpi_object *buffer = NULL;
1479         acpi_status status;
1480         int i, length;
1481
1482         if (!device || !acpi_driver_data(device))
1483                 return -EINVAL;
1484
1485         video = acpi_driver_data(device);
1486
1487         for (i = 0; i < video->attached_count; i++) {
1488                 video_device = video->attached_array[i].bind_info;
1489                 length = 256;
1490
1491                 if (!video_device)
1492                         continue;
1493
1494                 if (!video_device->cap._DDC)
1495                         continue;
1496
1497                 if (type) {
1498                         switch (type) {
1499                         case ACPI_VIDEO_DISPLAY_CRT:
1500                                 if (!video_device->flags.crt)
1501                                         continue;
1502                                 break;
1503                         case ACPI_VIDEO_DISPLAY_TV:
1504                                 if (!video_device->flags.tvout)
1505                                         continue;
1506                                 break;
1507                         case ACPI_VIDEO_DISPLAY_DVI:
1508                                 if (!video_device->flags.dvi)
1509                                         continue;
1510                                 break;
1511                         case ACPI_VIDEO_DISPLAY_LCD:
1512                                 if (!video_device->flags.lcd)
1513                                         continue;
1514                                 break;
1515                         }
1516                 } else if (video_device->device_id != device_id) {
1517                         continue;
1518                 }
1519
1520                 status = acpi_video_device_EDID(video_device, &buffer, length);
1521
1522                 if (ACPI_FAILURE(status) || !buffer ||
1523                     buffer->type != ACPI_TYPE_BUFFER) {
1524                         length = 128;
1525                         status = acpi_video_device_EDID(video_device, &buffer,
1526                                                         length);
1527                         if (ACPI_FAILURE(status) || !buffer ||
1528                             buffer->type != ACPI_TYPE_BUFFER) {
1529                                 continue;
1530                         }
1531                 }
1532
1533                 *edid = buffer->buffer.pointer;
1534                 return length;
1535         }
1536
1537         return -ENODEV;
1538 }
1539 EXPORT_SYMBOL(acpi_video_get_edid);
1540
1541 static int
1542 acpi_video_bus_get_devices(struct acpi_video_bus *video,
1543                            struct acpi_device *device)
1544 {
1545         int status = 0;
1546         struct acpi_device *dev;
1547
1548         /*
1549          * There are systems where video module known to work fine regardless
1550          * of broken _DOD and ignoring returned value here doesn't cause
1551          * any issues later.
1552          */
1553         acpi_video_device_enumerate(video);
1554
1555         list_for_each_entry(dev, &device->children, node) {
1556
1557                 status = acpi_video_bus_get_one_device(dev, video);
1558                 if (status) {
1559                         dev_err(&dev->dev, "Can't attach device\n");
1560                         break;
1561                 }
1562                 video->child_count++;
1563         }
1564         return status;
1565 }
1566
1567 /* acpi_video interface */
1568
1569 /*
1570  * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
1571  * perform any automatic brightness change on receiving a notification.
1572  */
1573 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
1574 {
1575         return acpi_video_bus_DOS(video, 0,
1576                                   acpi_osi_is_win8() ? 1 : 0);
1577 }
1578
1579 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
1580 {
1581         return acpi_video_bus_DOS(video, 0,
1582                                   acpi_osi_is_win8() ? 0 : 1);
1583 }
1584
1585 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)
1586 {
1587         struct acpi_video_bus *video = acpi_driver_data(device);
1588         struct input_dev *input;
1589         int keycode = 0;
1590
1591         if (!video || !video->input)
1592                 return;
1593
1594         input = video->input;
1595
1596         switch (event) {
1597         case ACPI_VIDEO_NOTIFY_SWITCH:  /* User requested a switch,
1598                                          * most likely via hotkey. */
1599                 keycode = KEY_SWITCHVIDEOMODE;
1600                 break;
1601
1602         case ACPI_VIDEO_NOTIFY_PROBE:   /* User plugged in or removed a video
1603                                          * connector. */
1604                 acpi_video_device_enumerate(video);
1605                 acpi_video_device_rebind(video);
1606                 keycode = KEY_SWITCHVIDEOMODE;
1607                 break;
1608
1609         case ACPI_VIDEO_NOTIFY_CYCLE:   /* Cycle Display output hotkey pressed. */
1610                 keycode = KEY_SWITCHVIDEOMODE;
1611                 break;
1612         case ACPI_VIDEO_NOTIFY_NEXT_OUTPUT:     /* Next Display output hotkey pressed. */
1613                 keycode = KEY_VIDEO_NEXT;
1614                 break;
1615         case ACPI_VIDEO_NOTIFY_PREV_OUTPUT:     /* previous Display output hotkey pressed. */
1616                 keycode = KEY_VIDEO_PREV;
1617                 break;
1618
1619         default:
1620                 acpi_handle_debug(device->handle, "Unsupported event [0x%x]\n",
1621                                   event);
1622                 break;
1623         }
1624
1625         if (acpi_notifier_call_chain(device, event, 0))
1626                 /* Something vetoed the keypress. */
1627                 keycode = 0;
1628
1629         if (keycode && (report_key_events & REPORT_OUTPUT_KEY_EVENTS)) {
1630                 input_report_key(input, keycode, 1);
1631                 input_sync(input);
1632                 input_report_key(input, keycode, 0);
1633                 input_sync(input);
1634         }
1635 }
1636
1637 static void brightness_switch_event(struct acpi_video_device *video_device,
1638                                     u32 event)
1639 {
1640         if (!brightness_switch_enabled)
1641                 return;
1642
1643         video_device->switch_brightness_event = event;
1644         schedule_delayed_work(&video_device->switch_brightness_work, HZ / 10);
1645 }
1646
1647 static void acpi_video_device_notify(acpi_handle handle, u32 event, void *data)
1648 {
1649         struct acpi_video_device *video_device = data;
1650         struct acpi_device *device = NULL;
1651         struct acpi_video_bus *bus;
1652         struct input_dev *input;
1653         int keycode = 0;
1654
1655         if (!video_device)
1656                 return;
1657
1658         device = video_device->dev;
1659         bus = video_device->video;
1660         input = bus->input;
1661
1662         if (hw_changes_brightness > 0) {
1663                 if (video_device->backlight)
1664                         backlight_force_update(video_device->backlight,
1665                                                BACKLIGHT_UPDATE_HOTKEY);
1666                 acpi_notifier_call_chain(device, event, 0);
1667                 return;
1668         }
1669
1670         switch (event) {
1671         case ACPI_VIDEO_NOTIFY_CYCLE_BRIGHTNESS:        /* Cycle brightness */
1672                 brightness_switch_event(video_device, event);
1673                 keycode = KEY_BRIGHTNESS_CYCLE;
1674                 break;
1675         case ACPI_VIDEO_NOTIFY_INC_BRIGHTNESS:  /* Increase brightness */
1676                 brightness_switch_event(video_device, event);
1677                 keycode = KEY_BRIGHTNESSUP;
1678                 break;
1679         case ACPI_VIDEO_NOTIFY_DEC_BRIGHTNESS:  /* Decrease brightness */
1680                 brightness_switch_event(video_device, event);
1681                 keycode = KEY_BRIGHTNESSDOWN;
1682                 break;
1683         case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS: /* zero brightness */
1684                 brightness_switch_event(video_device, event);
1685                 keycode = KEY_BRIGHTNESS_ZERO;
1686                 break;
1687         case ACPI_VIDEO_NOTIFY_DISPLAY_OFF:     /* display device off */
1688                 brightness_switch_event(video_device, event);
1689                 keycode = KEY_DISPLAY_OFF;
1690                 break;
1691         default:
1692                 acpi_handle_debug(handle, "Unsupported event [0x%x]\n", event);
1693                 break;
1694         }
1695
1696         if (keycode)
1697                 may_report_brightness_keys = true;
1698
1699         acpi_notifier_call_chain(device, event, 0);
1700
1701         if (keycode && (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS)) {
1702                 input_report_key(input, keycode, 1);
1703                 input_sync(input);
1704                 input_report_key(input, keycode, 0);
1705                 input_sync(input);
1706         }
1707 }
1708
1709 static int acpi_video_resume(struct notifier_block *nb,
1710                                 unsigned long val, void *ign)
1711 {
1712         struct acpi_video_bus *video;
1713         struct acpi_video_device *video_device;
1714         int i;
1715
1716         switch (val) {
1717         case PM_POST_HIBERNATION:
1718         case PM_POST_SUSPEND:
1719         case PM_POST_RESTORE:
1720                 video = container_of(nb, struct acpi_video_bus, pm_nb);
1721
1722                 dev_info(&video->device->dev, "Restoring backlight state\n");
1723
1724                 for (i = 0; i < video->attached_count; i++) {
1725                         video_device = video->attached_array[i].bind_info;
1726                         if (video_device && video_device->brightness)
1727                                 acpi_video_device_lcd_set_level(video_device,
1728                                                 video_device->brightness->curr);
1729                 }
1730
1731                 return NOTIFY_OK;
1732         }
1733         return NOTIFY_DONE;
1734 }
1735
1736 static acpi_status
1737 acpi_video_bus_match(acpi_handle handle, u32 level, void *context,
1738                         void **return_value)
1739 {
1740         struct acpi_device *device = context;
1741         struct acpi_device *sibling;
1742
1743         if (handle == device->handle)
1744                 return AE_CTRL_TERMINATE;
1745
1746         sibling = acpi_fetch_acpi_dev(handle);
1747         if (!sibling)
1748                 return AE_OK;
1749
1750         if (!strcmp(acpi_device_name(sibling), ACPI_VIDEO_BUS_NAME))
1751                         return AE_ALREADY_EXISTS;
1752
1753         return AE_OK;
1754 }
1755
1756 static void acpi_video_dev_register_backlight(struct acpi_video_device *device)
1757 {
1758         struct backlight_properties props;
1759         struct pci_dev *pdev;
1760         acpi_handle acpi_parent;
1761         struct device *parent = NULL;
1762         int result;
1763         static int count;
1764         char *name;
1765
1766         result = acpi_video_init_brightness(device);
1767         if (result)
1768                 return;
1769
1770         if (disable_backlight_sysfs_if > 0)
1771                 return;
1772
1773         name = kasprintf(GFP_KERNEL, "acpi_video%d", count);
1774         if (!name)
1775                 return;
1776         count++;
1777
1778         acpi_get_parent(device->dev->handle, &acpi_parent);
1779
1780         pdev = acpi_get_pci_dev(acpi_parent);
1781         if (pdev) {
1782                 parent = &pdev->dev;
1783                 pci_dev_put(pdev);
1784         }
1785
1786         memset(&props, 0, sizeof(struct backlight_properties));
1787         props.type = BACKLIGHT_FIRMWARE;
1788         props.max_brightness =
1789                 device->brightness->count - ACPI_VIDEO_FIRST_LEVEL - 1;
1790         device->backlight = backlight_device_register(name,
1791                                                       parent,
1792                                                       device,
1793                                                       &acpi_backlight_ops,
1794                                                       &props);
1795         kfree(name);
1796         if (IS_ERR(device->backlight)) {
1797                 device->backlight = NULL;
1798                 return;
1799         }
1800
1801         /*
1802          * Save current brightness level in case we have to restore it
1803          * before acpi_video_device_lcd_set_level() is called next time.
1804          */
1805         device->backlight->props.brightness =
1806                         acpi_video_get_brightness(device->backlight);
1807
1808         device->cooling_dev = thermal_cooling_device_register("LCD",
1809                                 device->dev, &video_cooling_ops);
1810         if (IS_ERR(device->cooling_dev)) {
1811                 /*
1812                  * Set cooling_dev to NULL so we don't crash trying to free it.
1813                  * Also, why the hell we are returning early and not attempt to
1814                  * register video output if cooling device registration failed?
1815                  * -- dtor
1816                  */
1817                 device->cooling_dev = NULL;
1818                 return;
1819         }
1820
1821         dev_info(&device->dev->dev, "registered as cooling_device%d\n",
1822                  device->cooling_dev->id);
1823         result = sysfs_create_link(&device->dev->dev.kobj,
1824                         &device->cooling_dev->device.kobj,
1825                         "thermal_cooling");
1826         if (result)
1827                 pr_info("sysfs link creation failed\n");
1828
1829         result = sysfs_create_link(&device->cooling_dev->device.kobj,
1830                         &device->dev->dev.kobj, "device");
1831         if (result)
1832                 pr_info("Reverse sysfs link creation failed\n");
1833 }
1834
1835 static void acpi_video_run_bcl_for_osi(struct acpi_video_bus *video)
1836 {
1837         struct acpi_video_device *dev;
1838         union acpi_object *levels;
1839
1840         mutex_lock(&video->device_list_lock);
1841         list_for_each_entry(dev, &video->video_device_list, entry) {
1842                 if (!acpi_video_device_lcd_query_levels(dev->dev->handle, &levels))
1843                         kfree(levels);
1844         }
1845         mutex_unlock(&video->device_list_lock);
1846 }
1847
1848 static bool acpi_video_should_register_backlight(struct acpi_video_device *dev)
1849 {
1850         /*
1851          * Do not create backlight device for video output
1852          * device that is not in the enumerated list.
1853          */
1854         if (!acpi_video_device_in_dod(dev)) {
1855                 dev_dbg(&dev->dev->dev, "not in _DOD list, ignore\n");
1856                 return false;
1857         }
1858
1859         if (only_lcd)
1860                 return dev->flags.lcd;
1861         return true;
1862 }
1863
1864 static int acpi_video_bus_register_backlight(struct acpi_video_bus *video)
1865 {
1866         struct acpi_video_device *dev;
1867
1868         if (video->backlight_registered)
1869                 return 0;
1870
1871         acpi_video_run_bcl_for_osi(video);
1872
1873         if (acpi_video_get_backlight_type() != acpi_backlight_video)
1874                 return 0;
1875
1876         mutex_lock(&video->device_list_lock);
1877         list_for_each_entry(dev, &video->video_device_list, entry) {
1878                 if (acpi_video_should_register_backlight(dev))
1879                         acpi_video_dev_register_backlight(dev);
1880         }
1881         mutex_unlock(&video->device_list_lock);
1882
1883         video->backlight_registered = true;
1884
1885         video->pm_nb.notifier_call = acpi_video_resume;
1886         video->pm_nb.priority = 0;
1887         return register_pm_notifier(&video->pm_nb);
1888 }
1889
1890 static void acpi_video_dev_unregister_backlight(struct acpi_video_device *device)
1891 {
1892         if (device->backlight) {
1893                 backlight_device_unregister(device->backlight);
1894                 device->backlight = NULL;
1895         }
1896         if (device->brightness) {
1897                 kfree(device->brightness->levels);
1898                 kfree(device->brightness);
1899                 device->brightness = NULL;
1900         }
1901         if (device->cooling_dev) {
1902                 sysfs_remove_link(&device->dev->dev.kobj, "thermal_cooling");
1903                 sysfs_remove_link(&device->cooling_dev->device.kobj, "device");
1904                 thermal_cooling_device_unregister(device->cooling_dev);
1905                 device->cooling_dev = NULL;
1906         }
1907 }
1908
1909 static int acpi_video_bus_unregister_backlight(struct acpi_video_bus *video)
1910 {
1911         struct acpi_video_device *dev;
1912         int error;
1913
1914         if (!video->backlight_registered)
1915                 return 0;
1916
1917         error = unregister_pm_notifier(&video->pm_nb);
1918
1919         mutex_lock(&video->device_list_lock);
1920         list_for_each_entry(dev, &video->video_device_list, entry)
1921                 acpi_video_dev_unregister_backlight(dev);
1922         mutex_unlock(&video->device_list_lock);
1923
1924         video->backlight_registered = false;
1925
1926         return error;
1927 }
1928
1929 static void acpi_video_dev_add_notify_handler(struct acpi_video_device *device)
1930 {
1931         acpi_status status;
1932         struct acpi_device *adev = device->dev;
1933
1934         status = acpi_install_notify_handler(adev->handle, ACPI_DEVICE_NOTIFY,
1935                                              acpi_video_device_notify, device);
1936         if (ACPI_FAILURE(status))
1937                 dev_err(&adev->dev, "Error installing notify handler\n");
1938         else
1939                 device->flags.notify = 1;
1940 }
1941
1942 static int acpi_video_bus_add_notify_handler(struct acpi_video_bus *video)
1943 {
1944         struct input_dev *input;
1945         struct acpi_video_device *dev;
1946         int error;
1947
1948         video->input = input = input_allocate_device();
1949         if (!input) {
1950                 error = -ENOMEM;
1951                 goto out;
1952         }
1953
1954         error = acpi_video_bus_start_devices(video);
1955         if (error)
1956                 goto err_free_input;
1957
1958         snprintf(video->phys, sizeof(video->phys),
1959                         "%s/video/input0", acpi_device_hid(video->device));
1960
1961         input->name = acpi_device_name(video->device);
1962         input->phys = video->phys;
1963         input->id.bustype = BUS_HOST;
1964         input->id.product = 0x06;
1965         input->dev.parent = &video->device->dev;
1966         input->evbit[0] = BIT(EV_KEY);
1967         set_bit(KEY_SWITCHVIDEOMODE, input->keybit);
1968         set_bit(KEY_VIDEO_NEXT, input->keybit);
1969         set_bit(KEY_VIDEO_PREV, input->keybit);
1970         set_bit(KEY_BRIGHTNESS_CYCLE, input->keybit);
1971         set_bit(KEY_BRIGHTNESSUP, input->keybit);
1972         set_bit(KEY_BRIGHTNESSDOWN, input->keybit);
1973         set_bit(KEY_BRIGHTNESS_ZERO, input->keybit);
1974         set_bit(KEY_DISPLAY_OFF, input->keybit);
1975
1976         error = input_register_device(input);
1977         if (error)
1978                 goto err_stop_dev;
1979
1980         mutex_lock(&video->device_list_lock);
1981         list_for_each_entry(dev, &video->video_device_list, entry)
1982                 acpi_video_dev_add_notify_handler(dev);
1983         mutex_unlock(&video->device_list_lock);
1984
1985         return 0;
1986
1987 err_stop_dev:
1988         acpi_video_bus_stop_devices(video);
1989 err_free_input:
1990         input_free_device(input);
1991         video->input = NULL;
1992 out:
1993         return error;
1994 }
1995
1996 static void acpi_video_dev_remove_notify_handler(struct acpi_video_device *dev)
1997 {
1998         if (dev->flags.notify) {
1999                 acpi_remove_notify_handler(dev->dev->handle, ACPI_DEVICE_NOTIFY,
2000                                            acpi_video_device_notify);
2001                 dev->flags.notify = 0;
2002         }
2003 }
2004
2005 static void acpi_video_bus_remove_notify_handler(struct acpi_video_bus *video)
2006 {
2007         struct acpi_video_device *dev;
2008
2009         mutex_lock(&video->device_list_lock);
2010         list_for_each_entry(dev, &video->video_device_list, entry)
2011                 acpi_video_dev_remove_notify_handler(dev);
2012         mutex_unlock(&video->device_list_lock);
2013
2014         acpi_video_bus_stop_devices(video);
2015         input_unregister_device(video->input);
2016         video->input = NULL;
2017 }
2018
2019 static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
2020 {
2021         struct acpi_video_device *dev, *next;
2022
2023         mutex_lock(&video->device_list_lock);
2024         list_for_each_entry_safe(dev, next, &video->video_device_list, entry) {
2025                 list_del(&dev->entry);
2026                 kfree(dev);
2027         }
2028         mutex_unlock(&video->device_list_lock);
2029
2030         return 0;
2031 }
2032
2033 static int instance;
2034
2035 static int acpi_video_bus_add(struct acpi_device *device)
2036 {
2037         struct acpi_video_bus *video;
2038         int error;
2039         acpi_status status;
2040
2041         status = acpi_walk_namespace(ACPI_TYPE_DEVICE,
2042                                 device->parent->handle, 1,
2043                                 acpi_video_bus_match, NULL,
2044                                 device, NULL);
2045         if (status == AE_ALREADY_EXISTS) {
2046                 pr_info(FW_BUG
2047                         "Duplicate ACPI video bus devices for the"
2048                         " same VGA controller, please try module "
2049                         "parameter \"video.allow_duplicates=1\""
2050                         "if the current driver doesn't work.\n");
2051                 if (!allow_duplicates)
2052                         return -ENODEV;
2053         }
2054
2055         video = kzalloc(sizeof(struct acpi_video_bus), GFP_KERNEL);
2056         if (!video)
2057                 return -ENOMEM;
2058
2059         /* a hack to fix the duplicate name "VID" problem on T61 */
2060         if (!strcmp(device->pnp.bus_id, "VID")) {
2061                 if (instance)
2062                         device->pnp.bus_id[3] = '0' + instance;
2063                 instance++;
2064         }
2065         /* a hack to fix the duplicate name "VGA" problem on Pa 3553 */
2066         if (!strcmp(device->pnp.bus_id, "VGA")) {
2067                 if (instance)
2068                         device->pnp.bus_id[3] = '0' + instance;
2069                 instance++;
2070         }
2071
2072         video->device = device;
2073         strcpy(acpi_device_name(device), ACPI_VIDEO_BUS_NAME);
2074         strcpy(acpi_device_class(device), ACPI_VIDEO_CLASS);
2075         device->driver_data = video;
2076
2077         acpi_video_bus_find_cap(video);
2078         error = acpi_video_bus_check(video);
2079         if (error)
2080                 goto err_free_video;
2081
2082         mutex_init(&video->device_list_lock);
2083         INIT_LIST_HEAD(&video->video_device_list);
2084
2085         error = acpi_video_bus_get_devices(video, device);
2086         if (error)
2087                 goto err_put_video;
2088
2089         pr_info("%s [%s] (multi-head: %s  rom: %s  post: %s)\n",
2090                ACPI_VIDEO_DEVICE_NAME, acpi_device_bid(device),
2091                video->flags.multihead ? "yes" : "no",
2092                video->flags.rom ? "yes" : "no",
2093                video->flags.post ? "yes" : "no");
2094         mutex_lock(&video_list_lock);
2095         list_add_tail(&video->entry, &video_bus_head);
2096         mutex_unlock(&video_list_lock);
2097
2098         acpi_video_bus_register_backlight(video);
2099         acpi_video_bus_add_notify_handler(video);
2100
2101         return 0;
2102
2103 err_put_video:
2104         acpi_video_bus_put_devices(video);
2105         kfree(video->attached_array);
2106 err_free_video:
2107         kfree(video);
2108         device->driver_data = NULL;
2109
2110         return error;
2111 }
2112
2113 static int acpi_video_bus_remove(struct acpi_device *device)
2114 {
2115         struct acpi_video_bus *video = NULL;
2116
2117
2118         if (!device || !acpi_driver_data(device))
2119                 return -EINVAL;
2120
2121         video = acpi_driver_data(device);
2122
2123         acpi_video_bus_remove_notify_handler(video);
2124         acpi_video_bus_unregister_backlight(video);
2125         acpi_video_bus_put_devices(video);
2126
2127         mutex_lock(&video_list_lock);
2128         list_del(&video->entry);
2129         mutex_unlock(&video_list_lock);
2130
2131         kfree(video->attached_array);
2132         kfree(video);
2133
2134         return 0;
2135 }
2136
2137 static int __init is_i740(struct pci_dev *dev)
2138 {
2139         if (dev->device == 0x00D1)
2140                 return 1;
2141         if (dev->device == 0x7000)
2142                 return 1;
2143         return 0;
2144 }
2145
2146 static int __init intel_opregion_present(void)
2147 {
2148         int opregion = 0;
2149         struct pci_dev *dev = NULL;
2150         u32 address;
2151
2152         for_each_pci_dev(dev) {
2153                 if ((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
2154                         continue;
2155                 if (dev->vendor != PCI_VENDOR_ID_INTEL)
2156                         continue;
2157                 /* We don't want to poke around undefined i740 registers */
2158                 if (is_i740(dev))
2159                         continue;
2160                 pci_read_config_dword(dev, 0xfc, &address);
2161                 if (!address)
2162                         continue;
2163                 opregion = 1;
2164         }
2165         return opregion;
2166 }
2167
2168 /* Check if the chassis-type indicates there is no builtin LCD panel */
2169 static bool dmi_is_desktop(void)
2170 {
2171         const char *chassis_type;
2172         unsigned long type;
2173
2174         chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
2175         if (!chassis_type)
2176                 return false;
2177
2178         if (kstrtoul(chassis_type, 10, &type) != 0)
2179                 return false;
2180
2181         switch (type) {
2182         case 0x03: /* Desktop */
2183         case 0x04: /* Low Profile Desktop */
2184         case 0x05: /* Pizza Box */
2185         case 0x06: /* Mini Tower */
2186         case 0x07: /* Tower */
2187         case 0x10: /* Lunch Box */
2188         case 0x11: /* Main Server Chassis */
2189                 return true;
2190         }
2191
2192         return false;
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 the
2198  * lcd flag fixes this, enable this by default on any machines which are:
2199  * 1.  Win8 ready (where we also prefer the native backlight driver, so
2200  *     normally the acpi_video code should not register there anyways); *and*
2201  * 2.1 Report a desktop/server DMI chassis-type, or
2202  * 2.2 Are an ACPI-reduced-hardware platform (and thus won't use the EC for
2203        backlight control)
2204  */
2205 static bool should_check_lcd_flag(void)
2206 {
2207         if (!acpi_osi_is_win8())
2208                 return false;
2209
2210         if (dmi_is_desktop())
2211                 return true;
2212
2213         if (acpi_reduced_hardware())
2214                 return true;
2215
2216         return false;
2217 }
2218
2219 int acpi_video_register(void)
2220 {
2221         int ret = 0;
2222
2223         mutex_lock(&register_count_mutex);
2224         if (register_count) {
2225                 /*
2226                  * if the function of acpi_video_register is already called,
2227                  * don't register the acpi_video_bus again and return no error.
2228                  */
2229                 goto leave;
2230         }
2231
2232         if (only_lcd == -1)
2233                 only_lcd = should_check_lcd_flag();
2234
2235         dmi_check_system(video_dmi_table);
2236
2237         ret = acpi_bus_register_driver(&acpi_video_bus);
2238         if (ret)
2239                 goto leave;
2240
2241         /*
2242          * When the acpi_video_bus is loaded successfully, increase
2243          * the counter reference.
2244          */
2245         register_count = 1;
2246
2247 leave:
2248         mutex_unlock(&register_count_mutex);
2249         return ret;
2250 }
2251 EXPORT_SYMBOL(acpi_video_register);
2252
2253 void acpi_video_unregister(void)
2254 {
2255         mutex_lock(&register_count_mutex);
2256         if (register_count) {
2257                 acpi_bus_unregister_driver(&acpi_video_bus);
2258                 register_count = 0;
2259                 may_report_brightness_keys = false;
2260         }
2261         mutex_unlock(&register_count_mutex);
2262 }
2263 EXPORT_SYMBOL(acpi_video_unregister);
2264
2265 void acpi_video_unregister_backlight(void)
2266 {
2267         struct acpi_video_bus *video;
2268
2269         mutex_lock(&register_count_mutex);
2270         if (register_count) {
2271                 mutex_lock(&video_list_lock);
2272                 list_for_each_entry(video, &video_bus_head, entry)
2273                         acpi_video_bus_unregister_backlight(video);
2274                 mutex_unlock(&video_list_lock);
2275         }
2276         mutex_unlock(&register_count_mutex);
2277 }
2278
2279 bool acpi_video_handles_brightness_key_presses(void)
2280 {
2281         return may_report_brightness_keys &&
2282                (report_key_events & REPORT_BRIGHTNESS_KEY_EVENTS);
2283 }
2284 EXPORT_SYMBOL(acpi_video_handles_brightness_key_presses);
2285
2286 /*
2287  * This is kind of nasty. Hardware using Intel chipsets may require
2288  * the video opregion code to be run first in order to initialise
2289  * state before any ACPI video calls are made. To handle this we defer
2290  * registration of the video class until the opregion code has run.
2291  */
2292
2293 static int __init acpi_video_init(void)
2294 {
2295         /*
2296          * Let the module load even if ACPI is disabled (e.g. due to
2297          * a broken BIOS) so that i915.ko can still be loaded on such
2298          * old systems without an AcpiOpRegion.
2299          *
2300          * acpi_video_register() will report -ENODEV later as well due
2301          * to acpi_disabled when i915.ko tries to register itself afterwards.
2302          */
2303         if (acpi_disabled)
2304                 return 0;
2305
2306         if (intel_opregion_present())
2307                 return 0;
2308
2309         return acpi_video_register();
2310 }
2311
2312 static void __exit acpi_video_exit(void)
2313 {
2314         acpi_video_detect_exit();
2315         acpi_video_unregister();
2316 }
2317
2318 module_init(acpi_video_init);
2319 module_exit(acpi_video_exit);