drivers/acpi/video_detect.c

   1 /*
   2  *  Copyright (C) 2015       Red Hat Inc.
   3  *                           Hans de Goede <hdegoede@redhat.com>
   4  *  Copyright (C) 2008       SuSE Linux Products GmbH
   5  *                           Thomas Renninger <trenn@suse.de>
   6  *
   7  *  May be copied or modified under the terms of the GNU General Public License
   8  *
   9  * video_detect.c:
  10  * After PCI devices are glued with ACPI devices
  11  * acpi_get_pci_dev() can be called to identify ACPI graphics
  12  * devices for which a real graphics card is plugged in
  13  *
  14  * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
  15  * are available, video.ko should be used to handle the device.
  16  *
  17  * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop,
  18  * sony_acpi,... can take care about backlight brightness.
  19  *
  20  * Backlight drivers can use acpi_video_get_backlight_type() to determine
  21  * which driver should handle the backlight.
  22  *
  23  * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
  24  * this file will not be compiled and acpi_video_get_backlight_type() will
  25  * always return acpi_backlight_vendor.
  26  */
  27
  28 #include <linux/export.h>
  29 #include <linux/acpi.h>
  30 #include <linux/backlight.h>
  31 #include <linux/dmi.h>
  32 #include <linux/module.h>
  33 #include <linux/pci.h>
  34 #include <linux/types.h>
  35 #include <linux/workqueue.h>
  36 #include <acpi/video.h>
  37
  38 ACPI_MODULE_NAME("video");
  39 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  40
  41 void acpi_video_unregister_backlight(void);
  42
  43 static bool backlight_notifier_registered;
  44 static struct notifier_block backlight_nb;
  45 static struct work_struct backlight_notify_work;
  46
  47 static enum acpi_backlight_type acpi_backlight_cmdline = acpi_backlight_undef;
  48 static enum acpi_backlight_type acpi_backlight_dmi = acpi_backlight_undef;
  49
  50 static void acpi_video_parse_cmdline(void)
  51 {
  52         if (!strcmp("vendor", acpi_video_backlight_string))
  53                 acpi_backlight_cmdline = acpi_backlight_vendor;
  54         if (!strcmp("video", acpi_video_backlight_string))
  55                 acpi_backlight_cmdline = acpi_backlight_video;
  56         if (!strcmp("native", acpi_video_backlight_string))
  57                 acpi_backlight_cmdline = acpi_backlight_native;
  58         if (!strcmp("none", acpi_video_backlight_string))
  59                 acpi_backlight_cmdline = acpi_backlight_none;
  60 }
  61
  62 static acpi_status
  63 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
  64 {
  65         long *cap = context;
  66         struct pci_dev *dev;
  67         struct acpi_device *acpi_dev;
  68
  69         static const struct acpi_device_id video_ids[] = {
  70                 {ACPI_VIDEO_HID, 0},
  71                 {"", 0},
  72         };
  73         if (acpi_bus_get_device(handle, &acpi_dev))
  74                 return AE_OK;
  75
  76         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
  77                 dev = acpi_get_pci_dev(handle);
  78                 if (!dev)
  79                         return AE_OK;
  80                 pci_dev_put(dev);
  81                 *cap |= acpi_is_video_device(handle);
  82         }
  83         return AE_OK;
  84 }
  85
  86 /* Force to use vendor driver when the ACPI device is known to be
  87  * buggy */
  88 static int video_detect_force_vendor(const struct dmi_system_id *d)
  89 {
  90         acpi_backlight_dmi = acpi_backlight_vendor;
  91         return 0;
  92 }
  93
  94 static int video_detect_force_video(const struct dmi_system_id *d)
  95 {
  96         acpi_backlight_dmi = acpi_backlight_video;
  97         return 0;
  98 }
  99
 100 static int video_detect_force_native(const struct dmi_system_id *d)
 101 {
 102         acpi_backlight_dmi = acpi_backlight_native;
 103         return 0;
 104 }
 105
 106 static const struct dmi_system_id video_detect_dmi_table[] = {
 107         /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
 108          * ACPI backlight device is used. This flag will definitively break
 109          * the backlight interface (even the vendor interface) untill next
 110          * reboot. It's why we should prevent video.ko from being used here
 111          * and we can't rely on a later call to acpi_video_unregister().
 112          */
 113         {
 114          .callback = video_detect_force_vendor,
 115          .ident = "X360",
 116          .matches = {
 117                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 118                 DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
 119                 DMI_MATCH(DMI_BOARD_NAME, "X360"),
 120                 },
 121         },
 122         {
 123         .callback = video_detect_force_vendor,
 124         .ident = "Asus UL30VT",
 125         .matches = {
 126                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 127                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
 128                 },
 129         },
 130         {
 131         .callback = video_detect_force_vendor,
 132         .ident = "Asus UL30A",
 133         .matches = {
 134                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 135                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
 136                 },
 137         },
 138         {
 139         .callback = video_detect_force_vendor,
 140         .ident = "Dell Inspiron 5737",
 141         .matches = {
 142                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 143                 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5737"),
 144                 },
 145         },
 146
 147         /*
 148          * These models have a working acpi_video backlight control, and using
 149          * native backlight causes a regression where backlight does not work
 150          * when userspace is not handling brightness key events. Disable
 151          * native_backlight on these to fix this:
 152          * https://bugzilla.kernel.org/show_bug.cgi?id=81691
 153          */
 154         {
 155          .callback = video_detect_force_video,
 156          .ident = "ThinkPad T420",
 157          .matches = {
 158                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 159                 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T420"),
 160                 },
 161         },
 162         {
 163          .callback = video_detect_force_video,
 164          .ident = "ThinkPad T520",
 165          .matches = {
 166                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 167                 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad T520"),
 168                 },
 169         },
 170         {
 171          .callback = video_detect_force_video,
 172          .ident = "ThinkPad X201s",
 173          .matches = {
 174                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 175                 DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad X201s"),
 176                 },
 177         },
 178
 179         /* The native backlight controls do not work on some older machines */
 180         {
 181          /* https://bugs.freedesktop.org/show_bug.cgi?id=81515 */
 182          .callback = video_detect_force_video,
 183          .ident = "HP ENVY 15 Notebook",
 184          .matches = {
 185                 DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 186                 DMI_MATCH(DMI_PRODUCT_NAME, "HP ENVY 15 Notebook PC"),
 187                 },
 188         },
 189         {
 190          .callback = video_detect_force_video,
 191          .ident = "SAMSUNG 870Z5E/880Z5E/680Z5E",
 192          .matches = {
 193                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 194                 DMI_MATCH(DMI_PRODUCT_NAME, "870Z5E/880Z5E/680Z5E"),
 195                 },
 196         },
 197         {
 198          .callback = video_detect_force_video,
 199          .ident = "SAMSUNG 370R4E/370R4V/370R5E/3570RE/370R5V",
 200          .matches = {
 201                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 202                 DMI_MATCH(DMI_PRODUCT_NAME,
 203                           "370R4E/370R4V/370R5E/3570RE/370R5V"),
 204                 },
 205         },
 206         {
 207          /* https://bugzilla.redhat.com/show_bug.cgi?id=1186097 */
 208          .callback = video_detect_force_video,
 209          .ident = "SAMSUNG 3570R/370R/470R/450R/510R/4450RV",
 210          .matches = {
 211                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 212                 DMI_MATCH(DMI_PRODUCT_NAME,
 213                           "3570R/370R/470R/450R/510R/4450RV"),
 214                 },
 215         },
 216         {
 217          /* https://bugzilla.redhat.com/show_bug.cgi?id=1094948 */
 218          .callback = video_detect_force_video,
 219          .ident = "SAMSUNG 730U3E/740U3E",
 220          .matches = {
 221                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 222                 DMI_MATCH(DMI_PRODUCT_NAME, "730U3E/740U3E"),
 223                 },
 224         },
 225         {
 226          /* https://bugs.freedesktop.org/show_bug.cgi?id=87286 */
 227          .callback = video_detect_force_video,
 228          .ident = "SAMSUNG 900X3C/900X3D/900X3E/900X4C/900X4D",
 229          .matches = {
 230                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 231                 DMI_MATCH(DMI_PRODUCT_NAME,
 232                           "900X3C/900X3D/900X3E/900X4C/900X4D"),
 233                 },
 234         },
 235         {
 236          /* https://bugzilla.redhat.com/show_bug.cgi?id=1163574 */
 237          .callback = video_detect_force_video,
 238          .ident = "Dell XPS15 L521X",
 239          .matches = {
 240                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 241                 DMI_MATCH(DMI_PRODUCT_NAME, "XPS L521X"),
 242                 },
 243         },
 244
 245         /* Non win8 machines which need native backlight nevertheless */
 246         {
 247          /* https://bugzilla.redhat.com/show_bug.cgi?id=1187004 */
 248          .callback = video_detect_force_native,
 249          .ident = "Lenovo Ideapad Z570",
 250          .matches = {
 251                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 252                 DMI_MATCH(DMI_PRODUCT_NAME, "102434U"),
 253                 },
 254         },
 255         {
 256          /* https://bugzilla.redhat.com/show_bug.cgi?id=1217249 */
 257          .callback = video_detect_force_native,
 258          .ident = "Apple MacBook Pro 12,1",
 259          .matches = {
 260                 DMI_MATCH(DMI_SYS_VENDOR, "Apple Inc."),
 261                 DMI_MATCH(DMI_PRODUCT_NAME, "MacBookPro12,1"),
 262                 },
 263         },
 264         { },
 265 };
 266
 267 /* This uses a workqueue to avoid various locking ordering issues */
 268 static void acpi_video_backlight_notify_work(struct work_struct *work)
 269 {
 270         if (acpi_video_get_backlight_type() != acpi_backlight_video)
 271                 acpi_video_unregister_backlight();
 272 }
 273
 274 static int acpi_video_backlight_notify(struct notifier_block *nb,
 275                                        unsigned long val, void *bd)
 276 {
 277         struct backlight_device *backlight = bd;
 278
 279         /* A raw bl registering may change video -> native */
 280         if (backlight->props.type == BACKLIGHT_RAW &&
 281             val == BACKLIGHT_REGISTERED)
 282                 schedule_work(&backlight_notify_work);
 283
 284         return NOTIFY_OK;
 285 }
 286
 287 /*
 288  * Determine which type of backlight interface to use on this system,
 289  * First check cmdline, then dmi quirks, then do autodetect.
 290  *
 291  * The autodetect order is:
 292  * 1) Is the acpi-video backlight interface supported ->
 293  *  no, use a vendor interface
 294  * 2) Is this a win8 "ready" BIOS and do we have a native interface ->
 295  *  yes, use a native interface
 296  * 3) Else use the acpi-video interface
 297  *
 298  * Arguably the native on win8 check should be done first, but that would
 299  * be a behavior change, which may causes issues.
 300  */
 301 enum acpi_backlight_type acpi_video_get_backlight_type(void)
 302 {
 303         static DEFINE_MUTEX(init_mutex);
 304         static bool init_done;
 305         static long video_caps;
 306
 307         /* Parse cmdline, dmi and acpi only once */
 308         mutex_lock(&init_mutex);
 309         if (!init_done) {
 310                 acpi_video_parse_cmdline();
 311                 dmi_check_system(video_detect_dmi_table);
 312                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 313                                     ACPI_UINT32_MAX, find_video, NULL,
 314                                     &video_caps, NULL);
 315                 INIT_WORK(&backlight_notify_work,
 316                           acpi_video_backlight_notify_work);
 317                 backlight_nb.notifier_call = acpi_video_backlight_notify;
 318                 backlight_nb.priority = 0;
 319                 if (backlight_register_notifier(&backlight_nb) == 0)
 320                         backlight_notifier_registered = true;
 321                 init_done = true;
 322         }
 323         mutex_unlock(&init_mutex);
 324
 325         if (acpi_backlight_cmdline != acpi_backlight_undef)
 326                 return acpi_backlight_cmdline;
 327
 328         if (acpi_backlight_dmi != acpi_backlight_undef)
 329                 return acpi_backlight_dmi;
 330
 331         if (!(video_caps & ACPI_VIDEO_BACKLIGHT))
 332                 return acpi_backlight_vendor;
 333
 334         if (acpi_osi_is_win8() && backlight_device_registered(BACKLIGHT_RAW))
 335                 return acpi_backlight_native;
 336
 337         return acpi_backlight_video;
 338 }
 339 EXPORT_SYMBOL(acpi_video_get_backlight_type);
 340
 341 /*
 342  * Set the preferred backlight interface type based on DMI info.
 343  * This function allows DMI blacklists to be implemented by external
 344  * platform drivers instead of putting a big blacklist in video_detect.c
 345  */
 346 void acpi_video_set_dmi_backlight_type(enum acpi_backlight_type type)
 347 {
 348         acpi_backlight_dmi = type;
 349         /* Remove acpi-video backlight interface if it is no longer desired */
 350         if (acpi_video_get_backlight_type() != acpi_backlight_video)
 351                 acpi_video_unregister_backlight();
 352 }
 353 EXPORT_SYMBOL(acpi_video_set_dmi_backlight_type);
 354
 355 void __exit acpi_video_detect_exit(void)
 356 {
 357         if (backlight_notifier_registered)
 358                 backlight_unregister_notifier(&backlight_nb);
 359 }