drm/i915/hdcp: Add new remote capability check shim function

Create a remote HDCP capability shim function which can read the
remote monitor HDCP capability when in MST configuration.

--v2
-Add an assertion to make sure only mst encoder call this remote_cap
function [Ankit]

--v3
-rename remote_hdcp_cap to remote_hdcp_capability [Jani]

--v4
-fix hdcp2_prerequisite check condition
-Move intel_dp_hdcp_get_remote_capability to dp_mst shim instead of
having it in dp shim [Ankit]

Signed-off-by: Suraj Kandpal <suraj.kandpal@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240226051017.1652970-2-suraj.kandpal@intel.com

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
index bf90e9024feb..eab6e9fab4e6 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
@@ -672,6 +672,32 @@ int intel_dp_hdcp2_get_capability(struct intel_connector *connector,
 	return _intel_dp_hdcp2_get_capability(aux, capable);
 }
 
+static
+int intel_dp_hdcp_get_remote_capability(struct intel_connector *connector,
+					bool *hdcp_capable,
+					bool *hdcp2_capable)
+{
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+	struct drm_dp_aux *aux = &connector->port->aux;
+	u8 bcaps;
+	int ret;
+
+	if (!intel_encoder_is_mst(connector->encoder))
+		return -EINVAL;
+
+	ret =  _intel_dp_hdcp2_get_capability(aux, hdcp2_capable);
+	if (ret)
+		return ret;
+
+	ret = intel_dp_hdcp_read_bcaps(aux, i915, &bcaps);
+	if (ret)
+		return ret;
+
+	*hdcp_capable = bcaps & DP_BCAPS_HDCP_CAPABLE;
+
+	return 0;
+}
+
 static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
 	.write_an_aksv = intel_dp_hdcp_write_an_aksv,
 	.read_bksv = intel_dp_hdcp_read_bksv,
@@ -820,6 +846,7 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
 	.stream_2_2_encryption = intel_dp_mst_hdcp2_stream_encryption,
 	.check_2_2_link = intel_dp_mst_hdcp2_check_link,
 	.hdcp_2_2_get_capability = intel_dp_hdcp2_get_capability,
+	.get_remote_hdcp_capability = intel_dp_hdcp_get_remote_capability,
 	.protocol = HDCP_PROTOCOL_DP,
 };