EDID 1.4: Decode CVT 3-byte codes and add them to the mode pool.

Section 3.10.3.8: CVT 3 Byte Code Descriptor Definition.

hw/xfree86/ddc/edid.h

@@ -449,17 +449,33 @@ struct whitePoints{
   float white_gamma;
 };
 
+struct cvt_timings {
+    int width;
+    int height;
+    int rate;
+    int rates;
+};
+
+/*
+ * Be careful when adding new sections; this structure can't grow, it's
+ * embedded in the middle of xf86Monitor which is ABI.  Sizes below are
+ * in bytes, for ILP32 systems.  If all else fails just copy the section
+ * literally like serial and friends.
+ */
 struct detailed_monitor_section {
   int type;
   union {
-    struct detailed_timings d_timings;
+    struct detailed_timings d_timings;	/* 56 */
     Uchar serial[13];
     Uchar ascii_data[13];
     Uchar name[13];
-    struct monitor_ranges ranges;
+    struct monitor_ranges ranges;	/* 40 */
-    struct std_timings std_t[5];
+    struct std_timings std_t[5];	/* 80 */
-    struct whitePoints wp[2];
+    struct whitePoints wp[2];		/* 32 */
-  } section;
+    /* color management data */
+    struct cvt_timings cvt[4];		/* 64 */
+    /* established timings III */
+  } section;				/* max: 80 */
 };
 
 typedef struct {

hw/xfree86/ddc/interpret_edid.c

@@ -174,6 +174,34 @@ get_established_timing_section(Uchar *c, struct established_timings *r)
     r->t_manu = T_MANU;
 }
 
+static void
+get_cvt_timing_section(Uchar *c, struct cvt_timings *r)
+{
+    int i;
+
+    for (i = 0; i < 4; i++) {
+	if (c[0] && c[1] && c[2]) {
+	    r[i].height = (c[0] + ((c[1] & 0xF0) << 8) + 1) * 2;
+	    switch (c[1] & 0xc0) {
+		case 0x00: r[i].width = r[i].height * 4 / 3; break;
+		case 0x40: r[i].width = r[i].height * 16 / 9; break;
+		case 0x80: r[i].width = r[i].height * 16 / 10; break;
+		case 0xc0: r[i].width = r[i].height * 15 / 9; break;
+	    }
+	    switch (c[2] & 0x60) {
+		case 0x00: r[i].rate = 50; break;
+		case 0x20: r[i].rate = 60; break;
+		case 0x40: r[i].rate = 75; break;
+		case 0x60: r[i].rate = 85; break;
+	    }
+	    r[i].rates = c[2] & 0x1f;
+	} else {
+	    return;
+	}
+	c += 3;
+    }
+}
+
 static void
 get_std_timing_section(Uchar *c, struct std_timings *r,
 		       struct edid_version *v)
@@ -232,6 +260,7 @@ get_dt_md_section(Uchar *c, struct edid_version *ver,
 	break;
       case CVT_3BYTE_DATA:
 	det_mon[i].type = DS_CVT;
+	get_cvt_timing_section(c, det_mon[i].section.cvt);
 	break;
       case ADD_EST_TIMINGS:
 	det_mon[i].type = DS_EST_III;

hw/xfree86/ddc/print_edid.c

@@ -235,6 +235,24 @@ print_std_timings(int scrnIndex, struct std_timings *t)
 	}
     }
 }
+
+static void
+print_cvt_timings(int si, struct cvt_timings *t)
+{
+    int i;
+
+    for (i = 0; i < 4; i++) {
+	if (t[i].height) {
+	    xf86DrvMsg(si, X_INFO, "%dx%d @ %s%s%s%s%s Hz\n",
+		    t[i].width, t[i].height,
+		    t[i].rates & 0x10 ? "50," : "",
+		    t[i].rates & 0x08 ? "60," : "",
+		    t[i].rates & 0x04 ? "75," : "",
+		    t[i].rates & 0x02 ? "85," : "",
+		    t[i].rates & 0x01 ? "60RB" : "");
+	} else break;
+    }
+}
   
 static void
 print_detailed_monitor_section(int scrnIndex,
@@ -296,7 +314,8 @@ print_detailed_monitor_section(int scrnIndex,
 	    break;
 	case DS_CVT:
 	    xf86DrvMsg(scrnIndex, X_INFO,
-		       "CVT 3-byte-code modes: (not decoded)\n");
+		       "CVT 3-byte-code modes:\n");
+	    print_cvt_timings(scrnIndex, m[i].section.cvt);
 	    break;
 	case DS_EST_III:
 	    xf86DrvMsg(scrnIndex, X_INFO,

hw/xfree86/modes/xf86EdidModes.c

@@ -354,6 +354,36 @@ DDCModeFromDetailedTiming(int scrnIndex, struct detailed_timings *timing,
     return Mode;
 }
 
+static DisplayModePtr
+DDCModesFromCVT(int scrnIndex, struct cvt_timings *t)
+{
+    DisplayModePtr modes = NULL;
+    int i;
+
+    for (i = 0; i < 4; i++) {
+	if (t[i].height) {
+	    if (t[i].rates & 0x10)
+		modes = xf86ModesAdd(modes,
+			xf86CVTMode(t[i].width, t[i].height, 50, 0, 0));
+	    if (t[i].rates & 0x08)
+		modes = xf86ModesAdd(modes,
+			xf86CVTMode(t[i].width, t[i].height, 60, 0, 0));
+	    if (t[i].rates & 0x04)
+		modes = xf86ModesAdd(modes,
+			xf86CVTMode(t[i].width, t[i].height, 75, 0, 0));
+	    if (t[i].rates & 0x02)
+		modes = xf86ModesAdd(modes,
+			xf86CVTMode(t[i].width, t[i].height, 85, 0, 0));
+	    if (t[i].rates & 0x01)
+		modes = xf86ModesAdd(modes,
+			xf86CVTMode(t[i].width, t[i].height, 60, 1, 0));
+	} else break;
+    }
+
+    return modes;
+}
+
+
 /*
  *
  */
@@ -527,6 +557,10 @@ xf86DDCGetModes(int scrnIndex, xf86MonPtr DDC)
 					      quirks);
             Modes = xf86ModesAdd(Modes, Mode);
             break;
+	case DS_CVT:
+	    Mode = DDCModesFromCVT(scrnIndex, det_mon->section.cvt);
+	    Modes = xf86ModesAdd(Modes, Mode);
+	    break;
         default:
             break;
         }