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 #define PREFIX "ACPI: "
  44
  45 ACPI_MODULE_NAME("video");
  46 #define _COMPONENT              ACPI_VIDEO_COMPONENT
  47
  48 static long acpi_video_support;
  49 static bool acpi_video_caps_checked;
  50
  51 static acpi_status
  52 acpi_backlight_cap_match(acpi_handle handle, u32 level, void *context,
  53                           void **return_value)
  54 {
  55         long *cap = context;
  56
  57         if (acpi_has_method(handle, "_BCM") &&
  58             acpi_has_method(handle, "_BCL")) {
  59                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found generic backlight "
  60                                   "support\n"));
  61                 *cap |= ACPI_VIDEO_BACKLIGHT;
  62                 if (!acpi_has_method(handle, "_BQC"))
  63                         printk(KERN_WARNING FW_BUG PREFIX "No _BQC method, "
  64                                 "cannot determine initial brightness\n");
  65                 /* We have backlight support, no need to scan further */
  66                 return AE_CTRL_TERMINATE;
  67         }
  68         return 0;
  69 }
  70
  71 /* Returns true if the ACPI object is a video device which can be
  72  * handled by video.ko.
  73  * The device will get a Linux specific CID added in scan.c to
  74  * identify the device as an ACPI graphics device
  75  * Be aware that the graphics device may not be physically present
  76  * Use acpi_video_get_capabilities() to detect general ACPI video
  77  * capabilities of present cards
  78  */
  79 long acpi_is_video_device(acpi_handle handle)
  80 {
  81         long video_caps = 0;
  82
  83         /* Is this device able to support video switching ? */
  84         if (acpi_has_method(handle, "_DOD") || acpi_has_method(handle, "_DOS"))
  85                 video_caps |= ACPI_VIDEO_OUTPUT_SWITCHING;
  86
  87         /* Is this device able to retrieve a video ROM ? */
  88         if (acpi_has_method(handle, "_ROM"))
  89                 video_caps |= ACPI_VIDEO_ROM_AVAILABLE;
  90
  91         /* Is this device able to configure which video head to be POSTed ? */
  92         if (acpi_has_method(handle, "_VPO") &&
  93             acpi_has_method(handle, "_GPD") &&
  94             acpi_has_method(handle, "_SPD"))
  95                 video_caps |= ACPI_VIDEO_DEVICE_POSTING;
  96
  97         /* Only check for backlight functionality if one of the above hit. */
  98         if (video_caps)
  99                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
 100                                     ACPI_UINT32_MAX, acpi_backlight_cap_match, NULL,
 101                                     &video_caps, NULL);
 102
 103         return video_caps;
 104 }
 105 EXPORT_SYMBOL(acpi_is_video_device);
 106
 107 static acpi_status
 108 find_video(acpi_handle handle, u32 lvl, void *context, void **rv)
 109 {
 110         long *cap = context;
 111         struct pci_dev *dev;
 112         struct acpi_device *acpi_dev;
 113
 114         const struct acpi_device_id video_ids[] = {
 115                 {ACPI_VIDEO_HID, 0},
 116                 {"", 0},
 117         };
 118         if (acpi_bus_get_device(handle, &acpi_dev))
 119                 return AE_OK;
 120
 121         if (!acpi_match_device_ids(acpi_dev, video_ids)) {
 122                 dev = acpi_get_pci_dev(handle);
 123                 if (!dev)
 124                         return AE_OK;
 125                 pci_dev_put(dev);
 126                 *cap |= acpi_is_video_device(handle);
 127         }
 128         return AE_OK;
 129 }
 130
 131 /* Force to use vendor driver when the ACPI device is known to be
 132  * buggy */
 133 static int video_detect_force_vendor(const struct dmi_system_id *d)
 134 {
 135         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 136         return 0;
 137 }
 138
 139 static struct dmi_system_id video_detect_dmi_table[] = {
 140         /* On Samsung X360, the BIOS will set a flag (VDRV) if generic
 141          * ACPI backlight device is used. This flag will definitively break
 142          * the backlight interface (even the vendor interface) untill next
 143          * reboot. It's why we should prevent video.ko from being used here
 144          * and we can't rely on a later call to acpi_video_unregister().
 145          */
 146         {
 147          .callback = video_detect_force_vendor,
 148          .ident = "X360",
 149          .matches = {
 150                 DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG ELECTRONICS CO., LTD."),
 151                 DMI_MATCH(DMI_PRODUCT_NAME, "X360"),
 152                 DMI_MATCH(DMI_BOARD_NAME, "X360"),
 153                 },
 154         },
 155         {
 156         .callback = video_detect_force_vendor,
 157         .ident = "Asus UL30VT",
 158         .matches = {
 159                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 160                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30VT"),
 161                 },
 162         },
 163         {
 164         .callback = video_detect_force_vendor,
 165         .ident = "Asus UL30A",
 166         .matches = {
 167                 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 168                 DMI_MATCH(DMI_PRODUCT_NAME, "UL30A"),
 169                 },
 170         },
 171         {
 172         .callback = video_detect_force_vendor,
 173         .ident = "Lenovo Yoga 13",
 174         .matches = {
 175                 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 176                 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Yoga 13"),
 177                 },
 178         },
 179         { },
 180 };
 181
 182 /*
 183  * Returns the video capabilities of a specific ACPI graphics device
 184  *
 185  * if NULL is passed as argument all ACPI devices are enumerated and
 186  * all graphics capabilities of physically present devices are
 187  * summarized and returned. This is cached and done only once.
 188  */
 189 long acpi_video_get_capabilities(acpi_handle graphics_handle)
 190 {
 191         long caps = 0;
 192         struct acpi_device *tmp_dev;
 193         acpi_status status;
 194
 195         if (acpi_video_caps_checked && graphics_handle == NULL)
 196                 return acpi_video_support;
 197
 198         if (!graphics_handle) {
 199                 /* Only do the global walk through all graphics devices once */
 200                 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
 201                                     ACPI_UINT32_MAX, find_video, NULL,
 202                                     &caps, NULL);
 203                 /* There might be boot param flags set already... */
 204                 acpi_video_support |= caps;
 205                 acpi_video_caps_checked = 1;
 206                 /* Add blacklists here. Be careful to use the right *DMI* bits
 207                  * to still be able to override logic via boot params, e.g.:
 208                  *
 209                  *   if (dmi_name_in_vendors("XY")) {
 210                  *      acpi_video_support |=
 211                  *              ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 212                  *}
 213                  */
 214
 215                 dmi_check_system(video_detect_dmi_table);
 216         } else {
 217                 status = acpi_bus_get_device(graphics_handle, &tmp_dev);
 218                 if (ACPI_FAILURE(status)) {
 219                         ACPI_EXCEPTION((AE_INFO, status, "Invalid device"));
 220                         return 0;
 221                 }
 222                 acpi_walk_namespace(ACPI_TYPE_DEVICE, graphics_handle,
 223                                     ACPI_UINT32_MAX, find_video, NULL,
 224                                     &caps, NULL);
 225         }
 226         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "We have 0x%lX video support %s %s\n",
 227                           graphics_handle ? caps : acpi_video_support,
 228                           graphics_handle ? "on device " : "in general",
 229                           graphics_handle ? acpi_device_bid(tmp_dev) : ""));
 230         return caps;
 231 }
 232 EXPORT_SYMBOL(acpi_video_get_capabilities);
 233
 234 static void acpi_video_caps_check(void)
 235 {
 236         /*
 237          * We must check whether the ACPI graphics device is physically plugged
 238          * in. Therefore this must be called after binding PCI and ACPI devices
 239          */
 240         if (!acpi_video_caps_checked)
 241                 acpi_video_get_capabilities(NULL);
 242 }
 243
 244 bool acpi_osi_is_win8(void)
 245 {
 246         return acpi_gbl_osi_data >= ACPI_OSI_WIN_8;
 247 }
 248 EXPORT_SYMBOL(acpi_osi_is_win8);
 249
 250 /* Promote the vendor interface instead of the generic video module.
 251  * This function allow DMI blacklists to be implemented by externals
 252  * platform drivers instead of putting a big blacklist in video_detect.c
 253  * After calling this function you will probably want to call
 254  * acpi_video_unregister() to make sure the video module is not loaded
 255  */
 256 void acpi_video_dmi_promote_vendor(void)
 257 {
 258         acpi_video_caps_check();
 259         acpi_video_support |= ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 260 }
 261 EXPORT_SYMBOL(acpi_video_dmi_promote_vendor);
 262
 263 /* To be called when a driver who previously promoted the vendor
 264  * interface */
 265 void acpi_video_dmi_demote_vendor(void)
 266 {
 267         acpi_video_caps_check();
 268         acpi_video_support &= ~ACPI_VIDEO_BACKLIGHT_DMI_VENDOR;
 269 }
 270 EXPORT_SYMBOL(acpi_video_dmi_demote_vendor);
 271
 272 /* Returns true if video.ko can do backlight switching */
 273 int acpi_video_backlight_support(void)
 274 {
 275         acpi_video_caps_check();
 276
 277         /* First check for boot param -> highest prio */
 278         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR)
 279                 return 0;
 280         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO)
 281                 return 1;
 282
 283         /* Then check for DMI blacklist -> second highest prio */
 284         if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VENDOR)
 285                 return 0;
 286         else if (acpi_video_support & ACPI_VIDEO_BACKLIGHT_DMI_VIDEO)
 287                 return 1;
 288
 289         /* Then go the default way */
 290         return acpi_video_support & ACPI_VIDEO_BACKLIGHT;
 291 }
 292 EXPORT_SYMBOL(acpi_video_backlight_support);
 293
 294 /*
 295  * Use acpi_backlight=vendor/video to force that backlight switching
 296  * is processed by vendor specific acpi drivers or video.ko driver.
 297  */
 298 static int __init acpi_backlight(char *str)
 299 {
 300         if (str == NULL || *str == '\0')
 301                 return 1;
 302         else {
 303                 if (!strcmp("vendor", str))
 304                         acpi_video_support |=
 305                                 ACPI_VIDEO_BACKLIGHT_FORCE_VENDOR;
 306                 if (!strcmp("video", str))
 307                         acpi_video_support |=
 308                                 ACPI_VIDEO_BACKLIGHT_FORCE_VIDEO;
 309         }
 310         return 1;
 311 }
 312 __setup("acpi_backlight=", acpi_backlight);