Add xf86MonitorIsHDMI() helper.

hw/xfree86/ddc/interpret_edid.c

@@ -459,3 +459,56 @@ validate_version(int scrnIndex, struct edid_version *r)
 
     return TRUE;
 }
+
+/*
+ * Returns true if HDMI, false if definitely not or unknown.
+ */
+_X_EXPORT Bool
+xf86MonitorIsHDMI(xf86MonPtr mon)
+{
+    int i = 0, version, offset;
+    char *edid = NULL;
+
+    if (!mon)
+       return FALSE;
+
+    if (!(mon->flags & EDID_COMPLETE_RAWDATA))
+       return FALSE;
+
+    if (!mon->no_sections)
+       return FALSE;
+
+    edid = (char *)mon->rawData;
+    if (!edid)
+       return FALSE;
+
+    /* find the CEA extension block */
+    for (i = 1; i <= mon->no_sections; i++)
+       if (edid[i * 128] == 0x02)
+           break;
+    if (i == mon->no_sections + 1)
+       return FALSE;
+    edid += (i * 128);
+
+    version = edid[1];
+    offset = edid[2];
+    if (version < 3 || offset < 4)
+       return FALSE;
+
+    /* walk the cea data blocks */
+    for (i = 4; i < offset; i += (edid[i] & 0x1f) + 1) {
+       char *x = edid + i;
+
+       /* find a vendor specific block */
+       if ((x[0] & 0xe0) >> 5 == 0x03) {
+           int oui = (x[3] << 16) + (x[2] << 8) + x[1];
+
+           /* find the HDMI vendor OUI */
+           if (oui == 0x000c03)
+               return TRUE;
+       }
+    }
+
+    /* guess it's not HDMI after all */
+    return FALSE;
+}

hw/xfree86/ddc/xf86DDC.h

@@ -59,6 +59,7 @@ extern Bool xf86SetDDCproperties(
 
 DisplayModePtr xf86DDCGetModes(int scrnIndex, xf86MonPtr DDC);
 
+extern Bool
+xf86MonitorIsHDMI(xf86MonPtr mon);
+
 #endif
-
-

hw/xfree86/loader/xf86sym.c

@@ -922,6 +922,7 @@ _X_HIDDEN void *xfree86LookupTab[] = {
     SYMFUNC(xf86DoEEDID)
     SYMFUNC(xf86DDCMonitorSet)
     SYMFUNC(xf86SetDDCproperties)
+    SYMFUNC(xf86MonitorIsHDMI)
 
     SYMFUNC(xf86CreateI2CBusRec)
     SYMFUNC(xf86CreateI2CDevRec)