[PATCH 05/11] drm/i915/hdcp: Add new remote capability check shim function

[Suraj Kandpal <suraj.kandpal@xxxxxxxxx>]

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]

Signed-off-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
---
 .../drm/i915/display/intel_display_types.h    |  4 +++
 drivers/gpu/drm/i915/display/intel_dp_hdcp.c  | 26 +++++++++++++++++++
 drivers/gpu/drm/i915/display/intel_hdcp.c     | 16 ++++++++++++
 drivers/gpu/drm/i915/display/intel_hdcp.h     |  3 +++
 4 files changed, 49 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index ae2e8cff9d69..7e7a370a3b30 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -532,6 +532,10 @@ struct intel_hdcp_shim {
 	/* HDCP2.2 Link Integrity Check */
 	int (*check_2_2_link)(struct intel_digital_port *dig_port,
 			      struct intel_connector *connector);
+
+	/* HDCP remote sink cap */
+	int (*remote_hdcp_cap)(struct intel_connector *connector,
+			       bool *hdcp_capable, bool *hdcp2_capable);
 };
 
 struct intel_hdcp {
diff --git a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
index ef1a4c90c225..ccd274200f92 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_hdcp.c
@@ -668,6 +668,31 @@ int intel_dp_hdcp2_capable(struct intel_connector *connector,
 	return _intel_dp_hdcp2_capable(aux, capable);
 }
 
+static
+int intel_dp_hdcp_remote_cap(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_capable(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,
@@ -685,6 +710,7 @@ static const struct intel_hdcp_shim intel_dp_hdcp_shim = {
 	.config_stream_type = intel_dp_hdcp2_config_stream_type,
 	.check_2_2_link = intel_dp_hdcp2_check_link,
 	.hdcp_2_2_capable = intel_dp_hdcp2_capable,
+	.remote_hdcp_cap = intel_dp_hdcp_remote_cap,
 	.protocol = HDCP_PROTOCOL_DP,
 };
 
diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 4593ac10e2fa..2b739249b60c 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -205,6 +205,22 @@ bool intel_hdcp2_capable(struct intel_connector *connector)
 	return capable;
 }
 
+void intel_hdcp_remote_cap(struct intel_connector *connector,
+			   bool *hdcp_capable,
+			   bool *hdcp2_capable)
+{
+	struct intel_hdcp *hdcp = &connector->hdcp;
+
+	/* Remote Sink's capability for HDCP */
+	if (!hdcp->shim->remote_hdcp_cap)
+		return;
+
+	hdcp->shim->remote_hdcp_cap(connector, hdcp_capable, hdcp2_capable);
+
+	if (intel_hdcp2_prerequisite(connector))
+		*hdcp2_capable = false;
+}
+
 static bool intel_hdcp_in_use(struct drm_i915_private *i915,
 			      enum transcoder cpu_transcoder, enum port port)
 {
diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.h b/drivers/gpu/drm/i915/display/intel_hdcp.h
index a9c784fd9ba5..213d286ca3fa 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.h
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.h
@@ -40,6 +40,9 @@ void intel_hdcp_update_pipe(struct intel_atomic_state *state,
 bool is_hdcp_supported(struct drm_i915_private *i915, enum port port);
 bool intel_hdcp_capable(struct intel_connector *connector);
 bool intel_hdcp2_capable(struct intel_connector *connector);
+void intel_hdcp_remote_cap(struct intel_connector *connector,
+			   bool *hdcp_capable,
+			   bool *hdcp2_capable);
 void intel_hdcp_component_init(struct drm_i915_private *i915);
 void intel_hdcp_component_fini(struct drm_i915_private *i915);
 void intel_hdcp_cleanup(struct intel_connector *connector);
-- 
2.25.1