drm/amd/display: Add enum for H-timing divider mode

Add h_timing_div_mode enum to better reflect possible register
values. Replace previously programmed values with enum
Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_optc.c

@@ -154,7 +154,7 @@ void optc1_program_timing(
 	uint32_t h_sync_polarity, v_sync_polarity;
 	uint32_t start_point = 0;
 	uint32_t field_num = 0;
-	uint32_t h_div_2;
+	enum h_timing_div_mode h_div = H_TIMING_NO_DIV;
 
 	struct optc *optc1 = DCN10TG_FROM_TG(optc);
 
@@ -285,10 +285,11 @@ void optc1_program_timing(
 	 * of stereo handled in explicit call
 	 */
 
-	h_div_2 = optc1_is_two_pixels_per_containter(&patched_crtc_timing);
-	REG_UPDATE(OTG_H_TIMING_CNTL,
-			OTG_H_TIMING_DIV_BY2, h_div_2 || optc1->opp_count == 2);
+	if (optc1_is_two_pixels_per_containter(&patched_crtc_timing) || optc1->opp_count == 2)
+		h_div = H_TIMING_DIV_BY2;
 
+	REG_UPDATE(OTG_H_TIMING_CNTL,
+		OTG_H_TIMING_DIV_BY2, h_div);
 }
 
 void optc1_set_vtg_params(struct timing_generator *optc,

drivers/gpu/drm/amd/display/dc/inc/hw/timing_generator.h

@@ -96,6 +96,11 @@ enum crc_selection {
 	INTERSECT_WINDOW_NOT_A_NOT_B,
 };
 
+enum h_timing_div_mode {
+	H_TIMING_NO_DIV,
+	H_TIMING_DIV_BY2,
+};
+
 struct crc_params {
 	/* Regions used to calculate CRC*/
 	uint16_t windowa_x_start;