drm/edid: Decode 3-byte CVT codes from EDID 1.4
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index cc8e696..30af8f3 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -897,6 +897,51 @@
return modes;
}
+static int drm_cvt_modes(struct drm_connector *connector,
+ struct detailed_timing *timing)
+{
+ int i, j, modes = 0;
+ struct drm_display_mode *newmode;
+ struct drm_device *dev = connector->dev;
+ struct cvt_timing *cvt;
+ const int rates[] = { 60, 85, 75, 60, 50 };
+
+ for (i = 0; i < 4; i++) {
+ int width, height;
+ cvt = &(timing->data.other_data.data.cvt[i]);
+
+ height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 8) + 1) * 2;
+ switch (cvt->code[1] & 0xc0) {
+ case 0x00:
+ width = height * 4 / 3;
+ break;
+ case 0x40:
+ width = height * 16 / 9;
+ break;
+ case 0x80:
+ width = height * 16 / 10;
+ break;
+ case 0xc0:
+ width = height * 15 / 9;
+ break;
+ }
+
+ for (j = 1; j < 5; j++) {
+ if (cvt->code[2] & (1 << j)) {
+ newmode = drm_cvt_mode(dev, width, height,
+ rates[j], j == 0,
+ false, false);
+ if (newmode) {
+ drm_mode_probed_add(connector, newmode);
+ modes++;
+ }
+ }
+ }
+ }
+
+ return modes;
+}
+
static int add_detailed_modes(struct drm_connector *connector,
struct detailed_timing *timing,
struct edid *edid, u32 quirks, int preferred)
@@ -941,6 +986,9 @@
}
}
break;
+ case EDID_DETAIL_CVT_3BYTE:
+ modes += drm_cvt_modes(connector, timing);
+ break;
default:
break;
}