drm/omap: DISPC: support double-pixel mode

We need double-pixel mode (pixel repetition) for interlace modes. This
patch adds the necessary support to DISPC to output double-pixel mode.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c
index 6b50476..1e7f269 100644
--- a/drivers/gpu/drm/omapdrm/dss/dispc.c
+++ b/drivers/gpu/drm/omapdrm/dss/dispc.c
@@ -104,6 +104,8 @@
 	bool supports_sync_align:1;
 
 	bool has_writeback:1;
+
+	bool supports_double_pixel:1;
 };
 
 #define DISPC_MAX_NR_FIFOS 5
@@ -3287,6 +3289,10 @@
 	} else {
 		if (t.interlace)
 			t.y_res /= 2;
+
+		if (dispc.feat->supports_double_pixel)
+			REG_FLD_MOD(DISPC_CONTROL, t.double_pixel ? 1 : 0,
+				19, 17);
 	}
 
 	dispc_mgr_set_size(channel, t.x_res, t.y_res);
@@ -3951,6 +3957,7 @@
 	.set_max_preload	=	true,
 	.supports_sync_align	=	true,
 	.has_writeback		=	true,
+	.supports_double_pixel	=	true,
 };
 
 static const struct dispc_features omap54xx_dispc_feats = {
@@ -3974,6 +3981,7 @@
 	.set_max_preload	=	true,
 	.supports_sync_align	=	true,
 	.has_writeback		=	true,
+	.supports_double_pixel	=	true,
 };
 
 static int dispc_init_features(struct platform_device *pdev)
diff --git a/include/video/omapdss.h b/include/video/omapdss.h
index 86f28a9..6c1a3e1 100644
--- a/include/video/omapdss.h
+++ b/include/video/omapdss.h
@@ -367,6 +367,8 @@
 	enum omap_dss_signal_level de_level;
 	/* Pixel clock edges to drive HSYNC and VSYNC signals */
 	enum omap_dss_signal_edge sync_pclk_edge;
+
+	bool double_pixel;
 };
 
 /* Hardcoded timings for tv modes. Venc only uses these to