OMAPDSS: DISPC: Add function to set channel in for writeback

Writeback can take input from either one of the overlays, or one of the overlay
managers. Add an enum which represents the channel_in for writeback, and maps
to the register field programming.

Add a function to configure channel in for writeback. This will be used later in
APPLY.
Signed-off-by: Archit Taneja <archit@ti.com>

drivers/video/omap2/dss/dispc.c

@@ -983,6 +983,13 @@ static enum omap_channel dispc_ovl_get_channel_out(enum omap_plane plane)
 	return channel;
 }
 
+void dispc_wb_set_channel_in(enum dss_writeback_channel channel)
+{
+	enum omap_plane plane = OMAP_DSS_WB;
+
+	REG_FLD_MOD(DISPC_OVL_ATTRIBUTES(plane), channel, 18, 16);
+}
+
 static void dispc_ovl_set_burst_size(enum omap_plane plane,
 		enum omap_burst_size burst_size)
 {

drivers/video/omap2/dss/dss.h

@@ -113,6 +113,17 @@ enum dss_dsi_content_type {
 	DSS_DSI_CONTENT_GENERIC,
 };
 
+enum dss_writeback_channel {
+	DSS_WB_LCD1_MGR =	0,
+	DSS_WB_LCD2_MGR =	1,
+	DSS_WB_TV_MGR =		2,
+	DSS_WB_OVL0 =		3,
+	DSS_WB_OVL1 =		4,
+	DSS_WB_OVL2 =		5,
+	DSS_WB_OVL3 =		6,
+	DSS_WB_LCD3_MGR =	7,
+};
+
 struct dss_clock_info {
 	/* rates that we get with dividers below */
 	unsigned long fck;
@@ -475,6 +486,8 @@ int dispc_mgr_get_clock_div(enum omap_channel channel,
 void dispc_mgr_setup(enum omap_channel channel,
 		struct omap_overlay_manager_info *info);
 
+void dispc_wb_set_channel_in(enum dss_writeback_channel channel);
+
 /* VENC */
 #ifdef CONFIG_OMAP2_DSS_VENC
 int venc_init_platform_driver(void) __init;