kernel/drivers/acpi/video_detect.c

   1 /*
   2  *  Copyright (C) 2008       SuSE Linux Products GmbH
   3  *                           Thomas Renninger <trenn@suse.de>
   4  *
   5  *  May be copied or modified under the terms of the GNU General Public License
   6  *
   7  * video_detect.c:
   8  * Provides acpi_is_video_device() for early scanning of ACPI devices in scan.c
   9  * There a Linux specific (Spec does not provide a HID for video devices) is
  10  * assigned
  11  *
  12  * After PCI devices are glued with ACPI devices
  13  * acpi_get_pci_dev() can be called to identify ACPI graphics
  14  * devices for which a real graphics card is plugged in
  15  *
  16  * Now acpi_video_get_capabilities() can be called to check which
  17  * capabilities the graphics cards plugged in support. The check for general
  18  * video capabilities will be triggered by the first caller of
  19  * acpi_video_get_capabilities(NULL); which will happen when the first
  20  * backlight switching supporting driver calls:
  21  * acpi_video_backlight_support();
  22  *
  23  * Depending on whether ACPI graphics extensions (cmp. ACPI spec Appendix B)
  24  * are available, video.ko should be used to handle the device.
  25  *
  26  * Otherwise vendor specific drivers like thinkpad_acpi, asus-laptop,
  27  * sony_acpi,... can take care about backlight brightness.
  28  *
  29  * If CONFIG_ACPI_VIDEO is neither set as "compiled in" (y) nor as a module (m)
  30  * this file will not be compiled, acpi_video_get_capabilities() and
  31  * acpi_video_backlight_support() will always return 0 and vendor specific
  32  * drivers always can handle backlight.
  33  *
  34  */
  35
  36 #include <linux/export.h>
  37 #include <linux/acpi.h>
  38 #include <linux/dmi.h>
  39 #include <linux/pci.h>
  40
  41 #include "internal.h"
  42
  43 ACPI_MODULE_NAME("video");
  44 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  45
  46 static long acpi_video_support;
  47 static bool acpi_video_caps_checked;
  48
  49 static acpi_status
  50 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
  51                           void **return_value)
  52 {
  53         long *cap = context;
  54
  55         if (acpi_has_method(handle, "_BCM") &&
  56             acpi_has_method(handle, "_BCL")) {
  57                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
  58                                   "support\n"));
  59                 *cap |= ACPI_VIDEO_BACKLIGHT;
  60                 if (!acpi_has_method(handle, "_BQC"))
  61                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
  62                                 "cannot determine initial brightness\n");
  63                 /* We have backlight support, no need to scan further */
  64                 return AE_CTRL_TERMINATE;
  65         }
  66         return 0;
  67 }
  68
  69 /* Returns true if the ACPI object is a video device which can be
  70  * handled by video.ko.
  71  * The device will get a Linux specific CID added in scan.c to
  72  * identify the device as an ACPI graphics device
  73  * Be aware that the graphics device may not be physically present
  74  * Use acpi_video_get_capabilities() to detect general ACPI video
  75  * capabilities of present cards
  76  */
  77 long acpi_is_video_device(acpi_handle handle)
  78 {
  79         long video_caps = 0;
  80
  81         /* Is this device able to support video switching ? */
  82         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
  83                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
  84
  85         /* Is this device able to retrieve a video ROM ? */
  86         if (acpi_has_method(handle, "_ROM"))
  87                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
  88
  89         /* Is this device able to configure which video head to be POSTed ? */
  90         if (acpi_has_method(handle, "_VPO") &&
  91             acpi_has_method(handle, "_GPD") &&
  92             acpi_has_method(handle, "_SPD"))
  93                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
  94
  95         /* Only check for backlight functionality if one of the above hit. */
  96         if (video_caps)
  97                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
  98                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
  99                                     &video_caps, NULL);
 100
 101         return video_caps;
 102 }
 103 EXPORT_SYMBOL(acpi_is_video_device);
 104
 105 static acpi_status
 106 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
 107 {
 108         long *cap = context;
 109         struct pci_dev *dev;
 110         struct acpi_device *acpi_dev;
 111
 112         const struct acpi_device_id video_ids[] = {
 113                 {ACPI_VIDEO_HID, 0},
 114                 {"", 0},
 115         };
 116         if (acpi_bus_get_device(handle, &acpi_dev))
 117                 return AE_OK;
 118
 119         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
 120                 dev = acpi_get_pci_dev(handle);
 121                 if (!dev)
 122                         return AE_OK;
 123                 pci_dev_put(dev);
 124                 *cap |= acpi_is_video_device(handle);
 125         }
 126         return AE_OK;
 127 }
 128
 129 /* Force to use vendor driver when the ACPI device is known to be
 130  * buggy */
 131 static int video_detect_force_vendor(const struct dmi_system_id *d)
 132 {
 133         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 134         return 0;
 135 }
 136
 137 static struct dmi_system_id video_detect_dmi_table[] = {
 138         /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
 139          * ACPI backlight device is used. This flag will definitively break
 140          * the backlight interface (even the vendor interface) untill next
 141          * reboot. It's why we should prevent video.ko from being used here
 142          * and we can't rely on a later call to acpi_video_unregister().
 143          */
 144         {
 145          .callback = video_detect_force_vendor,
 146          .ident = "X360",
 147          .matches = {
 148                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 149                 DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
 150                 DMI_MATCH(DMI_BOARD_NAME, "X360"),
 151                 },
 152         },
 153         {
 154         .callback = video_detect_force_vendor,
 155         .ident = "Asus UL30VT",
 156         .matches = {
 157                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 158                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
 159                 },
 160         },
 161         {
 162         .callback = video_detect_force_vendor,
 163         .ident = "Asus UL30A",
 164         .matches = {
 165                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 166                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
 167                 },
 168         },
 169         {
 170         .callback = video_detect_force_vendor,
 171         .ident = "Dell Inspiron 5737",
 172         .matches = {
 173                 DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
 174                 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 5737"),
 175                 },
 176         },
 177         { },
 178 };
 179
 180 /*
 181  * Returns the video capabilities of a specific ACPI graphics device
 182  *
 183  * if NULL is passed as argument all ACPI devices are enumerated and
 184  * all graphics capabilities of physically present devices are
 185  * summarized and returned. This is cached and done only once.
 186  */
 187 long acpi_video_get_capabilities(acpi_handle graphics_handle)
 188 {
 189         long caps = 0;
 190         struct acpi_device *tmp_dev;
 191         acpi_status status;
 192
 193         if (acpi_video_caps_checked && graphics_handle == NULL)
 194                 return acpi_video_support;
 195
 196         if (!graphics_handle) {
 197                 /* Only do the global walk through all graphics devices once */
 198                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 199                                     ACPI_UINT32_MAX, find_video, NULL,
 200                                     &caps, NULL);
 201                 /* There might be boot param flags set already... */
 202                 acpi_video_support |= caps;
 203                 acpi_video_caps_checked = 1;
 204                 /* Add blacklists here. Be careful to use the right *DMI* bits
 205                  * to still be able to override logic via boot params, e.g.:
 206                  *
 207                  *   if (dmi_name_in_vendors("XY")) {
 208                  *      acpi_video_support |=
 209                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 210                  *}
 211                  */
 212
 213                 dmi_check_system(video_detect_dmi_table);
 214         } else {
 215                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
 216                 if (ACPI_FAILURE(status)) {
 217                         ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
 218                         return 0;
 219                 }
 220                 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
 221                                     ACPI_UINT32_MAX, find_video, NULL,
 222                                     &caps, NULL);
 223         }
 224         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
 225                           graphics_handle ? caps : acpi_video_support,
 226                           graphics_handle ? "on device " : "in general",
 227                           graphics_handle ? acpi_device_bid(tmp_dev) : ""));
 228         return caps;
 229 }
 230 EXPORT_SYMBOL(acpi_video_get_capabilities);
 231
 232 static void acpi_video_caps_check(void)
 233 {
 234         /*
 235          * We must check whether the ACPI graphics device is physically plugged
 236          * in. Therefore this must be called after binding PCI and ACPI devices
 237          */
 238         if (!acpi_video_caps_checked)
 239                 acpi_video_get_capabilities(NULL);
 240 }
 241
 242 bool acpi_osi_is_win8(void)
 243 {
 244         return acpi_gbl_osi_data >= ACPI_OSI_WIN_8;
 245 }
 246 EXPORT_SYMBOL(acpi_osi_is_win8);
 247
 248 /* Promote the vendor interface instead of the generic video module.
 249  * This function allow DMI blacklists to be implemented by externals
 250  * platform drivers instead of putting a big blacklist in video_detect.c
 251  * After calling this function you will probably want to call
 252  * acpi_video_unregister() to make sure the video module is not loaded
 253  */
 254 void acpi_video_dmi_promote_vendor(void)
 255 {
 256         acpi_video_caps_check();
 257         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 258 }
 259 EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);
 260
 261 /* To be called when a driver who previously promoted the vendor
 262  * interface */
 263 void acpi_video_dmi_demote_vendor(void)
 264 {
 265         acpi_video_caps_check();
 266         acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 267 }
 268 EXPORT_SYMBOL(acpi_video_dmi_demote_vendor);
 269
 270 /* Returns true if video.ko can do backlight switching */
 271 int acpi_video_backlight_support(void)
 272 {
 273         acpi_video_caps_check();
 274
 275         /* First check for boot param -> highest prio */
 276         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
 277                 return 0;
 278         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
 279                 return 1;
 280
 281         /* Then check for DMI blacklist -> second highest prio */
 282         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
 283                 return 0;
 284         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
 285                 return 1;
 286
 287         /* Then go the default way */
 288         return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
 289 }
 290 EXPORT_SYMBOL(acpi_video_backlight_support);
 291
 292 /*
 293  * Use acpi_backlight=vendor/video to force that backlight switching
 294  * is processed by vendor specific acpi drivers or video.ko driver.
 295  */
 296 static int __init acpi_backlight(char *str)
 297 {
 298         if (str == NULL || *str == '\0')
 299                 return 1;
 300         else {
 301                 if (!strcmp("vendor", str))
 302                         acpi_video_support |=
 303                                 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
 304                 if (!strcmp("video", str))
 305                         acpi_video_support |=
 306                                 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
 307         }
 308         return 1;
 309 }
 310 __setup("acpi_backlight=", acpi_backlight);