OMAP: DSS2: add dss_get_hdmi_venc_clk_source()

Add dss_get_hdmi_venc_clk_source(), which can be used to get the value
programmed with dss_select_hdmi_venc_clk_source(). This can be used to
find out if the digit output is going to VENC or HDMI.

For OMAP2/3 dss_get_hdmi_venc_clk_source() always returns
DSS_VENC_TV_CLK.

Cc: Mythri P K <mythripk@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss.c b/drivers/video/omap2/dss/dss.c
index 356d3c1..3e09726 100644
--- a/drivers/video/omap2/dss/dss.c
+++ b/drivers/video/omap2/dss/dss.c
@@ -639,6 +639,17 @@
 	REG_FLD_MOD(DSS_CONTROL, hdmi, 15, 15);	/* VENC_HDMI_SWITCH */
 }
 
+enum dss_hdmi_venc_clk_source_select dss_get_hdmi_venc_clk_source(void)
+{
+	enum omap_display_type displays;
+
+	displays = dss_feat_get_supported_displays(OMAP_DSS_CHANNEL_DIGIT);
+	if ((displays & OMAP_DISPLAY_TYPE_HDMI) == 0)
+		return DSS_VENC_TV_CLK;
+
+	return REG_GET(DSS_CONTROL, 15, 15);
+}
+
 static int dss_get_clocks(void)
 {
 	struct clk *clk;