drm/nouveau: add overscan compensation connector properties

Exposes the same connector properties as the Radeon implementation, however
their behaviour isn't exactly the same.  The primary difference being that
unless both hborder/vborder have been defined by the user, the driver will
keep the aspect ratio of the overscanned area the same as the mode the
display is programmed for.

Enabled for digital outputs on GeForce 8 and up, excluding GF119.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 58 insertions, 41 deletions

diff --git a/drivers/gpu/drm/nouveau/nv50_crtc.c b/drivers/gpu/drm/nouveau/nv50_crtc.c
index 8eb108b28eb1..e426a9b9865a 100644
--- a/drivers/gpu/drm/nouveau/nv50_crtc.c
+++ b/drivers/gpu/drm/nouveau/nv50_crtc.c
@@ -215,74 +215,91 @@ nouveau_crtc_connector_get(struct nouveau_crtc *nv_crtc)
 static int
 nv50_crtc_set_scale(struct nouveau_crtc *nv_crtc, int scaling_mode, bool update)
 {
-	struct nouveau_connector *nv_connector =
-		nouveau_crtc_connector_get(nv_crtc);
+	struct nouveau_connector *nv_connector;
 	struct drm_crtc *crtc = &nv_crtc->base;
 	struct drm_device *dev = crtc->dev;
 	struct nouveau_channel *evo = nv50_display(dev)->master;
-	struct drm_display_mode *native_mode = NULL;
 	struct drm_display_mode *mode = &crtc->mode;
-	uint32_t outX, outY, horiz, vert;
+	u32 ctrl = 0, oX, oY;
 	int ret;
 
 	NV_DEBUG_KMS(dev, "\n");
 
-	switch (scaling_mode) {
-	case DRM_MODE_SCALE_NONE:
-		break;
-	default:
-		if (!nv_connector || !nv_connector->native_mode) {
-			NV_ERROR(dev, "No native mode, forcing panel scaling\n");
-			scaling_mode = DRM_MODE_SCALE_NONE;
+	nv_connector = nouveau_crtc_connector_get(nv_crtc);
+	if (!nv_connector || !nv_connector->native_mode) {
+		NV_ERROR(dev, "no native mode, forcing panel scaling\n");
+		scaling_mode = DRM_MODE_SCALE_NONE;
+	}
+
+	/* start off at the resolution we programmed the crtc for, this
+	 * effectively handles NONE/FULL scaling
+	 */
+	if (scaling_mode != DRM_MODE_SCALE_NONE) {
+		oX = nv_connector->native_mode->hdisplay;
+		oY = nv_connector->native_mode->vdisplay;
+	} else {
+		oX = mode->hdisplay;
+		oY = mode->vdisplay;
+	}
+
+	/* add overscan compensation if necessary, will keep the aspect
+	 * ratio the same as the backend mode unless overridden by the
+	 * user setting both hborder and vborder properties.
+	 */
+	if (nv_connector && ( nv_connector->underscan == UNDERSCAN_ON ||
+			     (nv_connector->underscan == UNDERSCAN_AUTO &&
+			      nv_connector->edid &&
+			      drm_detect_hdmi_monitor(nv_connector->edid)))) {
+		u32 bX = nv_connector->underscan_hborder;
+		u32 bY = nv_connector->underscan_vborder;
+		u32 aspect = (oY << 19) / oX;
+
+		if (bX) {
+			oX -= (bX * 2);
+			if (bY) oY -= (bY * 2);
+			else    oY  = ((oX * aspect) + (aspect / 2)) >> 19;
 		} else {
-			native_mode = nv_connector->native_mode;
+			oX -= (oX >> 4) + 32;
+			if (bY) oY -= (bY * 2);
+			else    oY  = ((oX * aspect) + (aspect / 2)) >> 19;
 		}
-		break;
 	}
 
+	/* handle CENTER/ASPECT scaling, taking into account the areas
+	 * removed already for overscan compensation
+	 */
 	switch (scaling_mode) {
+	case DRM_MODE_SCALE_CENTER:
+		oX = min((u32)mode->hdisplay, oX);
+		oY = min((u32)mode->vdisplay, oY);
+		/* fall-through */
 	case DRM_MODE_SCALE_ASPECT:
-		horiz = (native_mode->hdisplay << 19) / mode->hdisplay;
-		vert = (native_mode->vdisplay << 19) / mode->vdisplay;
-
-		if (vert > horiz) {
-			outX = (mode->hdisplay * horiz) >> 19;
-			outY = (mode->vdisplay * horiz) >> 19;
+		if (oY < oX) {
+			u32 aspect = (mode->hdisplay << 19) / mode->vdisplay;
+			oX = ((oY * aspect) + (aspect / 2)) >> 19;
 		} else {
-			outX = (mode->hdisplay * vert) >> 19;
-			outY = (mode->vdisplay * vert) >> 19;
+			u32 aspect = (mode->vdisplay << 19) / mode->hdisplay;
+			oY = ((oX * aspect) + (aspect / 2)) >> 19;
 		}
 		break;
-	case DRM_MODE_SCALE_FULLSCREEN:
-		outX = native_mode->hdisplay;
-		outY = native_mode->vdisplay;
-		break;
-	case DRM_MODE_SCALE_CENTER:
-	case DRM_MODE_SCALE_NONE:
 	default:
-		outX = mode->hdisplay;
-		outY = mode->vdisplay;
 		break;
 	}
 
+	if (mode->hdisplay != oX || mode->vdisplay != oY ||
+	    mode->flags & DRM_MODE_FLAG_INTERLACE ||
+	    mode->flags & DRM_MODE_FLAG_DBLSCAN)
+		ctrl |= NV50_EVO_CRTC_SCALE_CTRL_ACTIVE;
+
 	ret = RING_SPACE(evo, 5);
 	if (ret)
 		return ret;
 
-	/* Got a better name for SCALER_ACTIVE? */
-	/* One day i've got to really figure out why this is needed. */
 	BEGIN_RING(evo, 0, NV50_EVO_CRTC(nv_crtc->index, SCALE_CTRL), 1);
-	if ((mode->flags & DRM_MODE_FLAG_DBLSCAN) ||
-	    (mode->flags & DRM_MODE_FLAG_INTERLACE) ||
-	    mode->hdisplay != outX || mode->vdisplay != outY) {
-		OUT_RING(evo, NV50_EVO_CRTC_SCALE_CTRL_ACTIVE);
-	} else {
-		OUT_RING(evo, NV50_EVO_CRTC_SCALE_CTRL_INACTIVE);
-	}
-
+	OUT_RING  (evo, ctrl);
 	BEGIN_RING(evo, 0, NV50_EVO_CRTC(nv_crtc->index, SCALE_RES1), 2);
-	OUT_RING(evo, outY << 16 | outX);
-	OUT_RING(evo, outY << 16 | outX);
+	OUT_RING  (evo, oY << 16 | oX);
+	OUT_RING  (evo, oY << 16 | oX);
 
 	if (update) {
 		nv50_display_flip_stop(crtc);