drm/msm/dp: return correct Colorimetry for DP_TEST_DYNAMIC_RANGE_CEA case

MSA MISC0 bit 1 to 7 contains Colorimetry Indicator Field.
dp_link_get_colorimetry_config() returns wrong colorimetry value
in the DP_TEST_DYNAMIC_RANGE_CEA case in the current implementation.
Hence fix this problem by having dp_link_get_colorimetry_config()
return defined CEA RGB colorimetry value in the case of
DP_TEST_DYNAMIC_RANGE_CEA.

Changes in V2:
-- drop retrieving colorimetry from colorspace
-- drop dr = link->dp_link.test_video.test_dyn_range assignment

Changes in V3:
-- move defined MISCr0a Colorimetry vale to dp_reg.h
-- rewording commit title
-- rewording commit text to more precise describe this patch

Fixes: c943b49 ("drm/msm/dp: add displayPort driver support")
Signed-off-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/574888/
Link: https://lore.kernel.org/r/1705526010-597-1-git-send-email-quic_khsieh@quicinc.com
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>

Author: Kuogee Hsieh

drivers/gpu/drm/msm/dp/dp_link.c

@@ -7,6 +7,7 @@
 
 #include <drm/drm_print.h>
 
+#include "dp_reg.h"
 #include "dp_link.h"
 #include "dp_panel.h"
 
@@ -1082,7 +1083,7 @@ int dp_link_process_request(struct dp_link *dp_link)
 
 int dp_link_get_colorimetry_config(struct dp_link *dp_link)
 {
-	u32 cc;
+	u32 cc = DP_MISC0_COLORIMERY_CFG_LEGACY_RGB;
 	struct dp_link_private *link;
 
 	if (!dp_link) {
@@ -1096,10 +1097,11 @@ int dp_link_get_colorimetry_config(struct dp_link *dp_link)
 	 * Unless a video pattern CTS test is ongoing, use RGB_VESA
 	 * Only RGB_VESA and RGB_CEA supported for now
 	 */
-	if (dp_link_is_video_pattern_requested(link))
-		cc = link->dp_link.test_video.test_dyn_range;
-	else
-		cc = DP_TEST_DYNAMIC_RANGE_VESA;
+	if (dp_link_is_video_pattern_requested(link)) {
+		if (link->dp_link.test_video.test_dyn_range &
+					DP_TEST_DYNAMIC_RANGE_CEA)
+			cc = DP_MISC0_COLORIMERY_CFG_CEA_RGB;
+	}
 
 	return cc;
 }

drivers/gpu/drm/msm/dp/dp_reg.h

@@ -143,6 +143,9 @@
 #define DP_MISC0_COLORIMETRY_CFG_SHIFT		(0x00000001)
 #define DP_MISC0_TEST_BITS_DEPTH_SHIFT		(0x00000005)
 
+#define DP_MISC0_COLORIMERY_CFG_LEGACY_RGB	(0)
+#define DP_MISC0_COLORIMERY_CFG_CEA_RGB		(0x04)
+
 #define REG_DP_VALID_BOUNDARY			(0x00000030)
 #define REG_DP_VALID_BOUNDARY_2			(0x00000034)