[PATCH v2 17/18] drm/dp: Add helpers for DFP YCbCr 4:2:0 handling
Ville Syrjala
ville.syrjala at linux.intel.com
Fri Sep 4 11:53:53 UTC 2020
From: Ville Syrjälä <ville.syrjala at linux.intel.com>
Add helpers to determine whether the DFP supports
YCbCr 4:2:0 passthrough or YCbCr 4:4:4->4:2:0 conversion.
Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
drivers/gpu/drm/drm_dp_helper.c | 44 +++++++++++++++++++++++++++++++++
include/drm/drm_dp_helper.h | 8 ++++++
2 files changed, 52 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c
index 0d5e9bcf11d0..dc68e10aa1fd 100644
--- a/drivers/gpu/drm/drm_dp_helper.c
+++ b/drivers/gpu/drm/drm_dp_helper.c
@@ -808,6 +808,50 @@ int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
}
EXPORT_SYMBOL(drm_dp_downstream_max_bpc);
+bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+ const u8 port_cap[4])
+{
+ if (!drm_dp_is_branch(dpcd))
+ return false;
+
+ if (dpcd[DP_DPCD_REV] < 0x13)
+ return false;
+
+ switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
+ case DP_DS_PORT_TYPE_DP:
+ return true;
+ case DP_DS_PORT_TYPE_HDMI:
+ if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
+ return false;
+
+ return port_cap[3] & DP_DS_HDMI_YCBCR420_PASS_THROUGH;
+ default:
+ return false;
+ }
+}
+EXPORT_SYMBOL(drm_dp_downstream_420_passthrough);
+
+bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+ const u8 port_cap[4])
+{
+ if (!drm_dp_is_branch(dpcd))
+ return false;
+
+ if (dpcd[DP_DPCD_REV] < 0x13)
+ return false;
+
+ switch (port_cap[0] & DP_DS_PORT_TYPE_MASK) {
+ case DP_DS_PORT_TYPE_HDMI:
+ if ((dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) == 0)
+ return false;
+
+ return port_cap[3] & DP_DS_HDMI_YCBCR444_TO_420_CONV;
+ default:
+ return false;
+ }
+}
+EXPORT_SYMBOL(drm_dp_downstream_444_to_420_conversion);
+
/**
* drm_dp_downstream_mode() - return a mode for downstream facing port
* @dpcd: DisplayPort configuration data
diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index fbba4a0f7366..c9f2851904d0 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -407,6 +407,10 @@ struct drm_device;
# define DP_DS_DVI_HIGH_COLOR_DEPTH (1 << 2)
/* offset 3 for HDMI */
# define DP_DS_HDMI_FRAME_SEQ_TO_FRAME_PACK (1 << 0)
+# define DP_DS_HDMI_YCBCR422_PASS_THROUGH (1 << 1)
+# define DP_DS_HDMI_YCBCR420_PASS_THROUGH (1 << 2)
+# define DP_DS_HDMI_YCBCR444_TO_422_CONV (1 << 3)
+# define DP_DS_HDMI_YCBCR444_TO_420_CONV (1 << 4)
#define DP_MAX_DOWNSTREAM_PORTS 0x10
@@ -1663,6 +1667,10 @@ int drm_dp_downstream_min_tmds_clock(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
int drm_dp_downstream_max_bpc(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4],
const struct edid *edid);
+bool drm_dp_downstream_420_passthrough(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+ const u8 port_cap[4]);
+bool drm_dp_downstream_444_to_420_conversion(const u8 dpcd[DP_RECEIVER_CAP_SIZE],
+ const u8 port_cap[4]);
struct drm_display_mode *drm_dp_downstream_mode(struct drm_device *dev,
const u8 dpcd[DP_RECEIVER_CAP_SIZE],
const u8 port_cap[4]);
--
2.26.2
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