[PATCH v10 01/23] drm/dsc: Modify DRM helper to return complete DSC color depth capabilities

[Manasi Navare]

DSC DPCD color depth register advertises its color depth capabilities
by setting each of the bits that corresponding to a specific color
depth. This patch defines those specific color depths and adds
a helper to return an array of color depth capabilities.

v2:
* Simplify the logic (Ville)

Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
---
 drivers/gpu/drm/drm_dp_helper.c | 14 ++++++++------
 include/drm/drm_dp_helper.h     |  3 ++-
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 6d483487f2b4..2d6c491a0542 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -1428,17 +1428,19 @@ u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
 }
 EXPORT_SYMBOL(drm_dp_dsc_sink_line_buf_depth);
 
-u8 drm_dp_dsc_sink_max_color_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
+int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
+					 u8 dsc_bpc[3])
 {
+	int num_bpc = 0;
 	u8 color_depth = dsc_dpcd[DP_DSC_DEC_COLOR_DEPTH_CAP - DP_DSC_SUPPORT];
 
 	if (color_depth & DP_DSC_12_BPC)
-		return 12;
+		dsc_bpc[num_bpc++] = 12;
 	if (color_depth & DP_DSC_10_BPC)
-		return 10;
+		dsc_bpc[num_bpc++] = 10;
 	if (color_depth & DP_DSC_8_BPC)
-		return 8;
+		dsc_bpc[num_bpc++] = 8;
 
-	return 0;
+	return num_bpc;
 }
-EXPORT_SYMBOL(drm_dp_dsc_sink_max_color_depth);
+EXPORT_SYMBOL(drm_dp_dsc_sink_supported_input_bpcs);
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 3314e91f6eb3..5736c942c85b 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1123,7 +1123,8 @@ drm_dp_is_branch(const u8 dpcd[DP_RECEIVER_CAP_SIZE])
 u8 drm_dp_dsc_sink_max_slice_count(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE],
 				   bool is_edp);
 u8 drm_dp_dsc_sink_line_buf_depth(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]);
-u8 drm_dp_dsc_sink_max_color_depth(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE]);
+int drm_dp_dsc_sink_supported_input_bpcs(const u8 dsc_dpc[DP_DSC_RECEIVER_CAP_SIZE],
+					 u8 dsc_bpc[3]);
 
 static inline bool
 drm_dp_sink_supports_dsc(const u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE])
-- 
2.19.1