drm/i915/hdcp: Support for HDCP 2.2 MST shim callbacks

Add support for HDCP 2.2 DP MST shim callback.
This adds existing DP HDCP shim callback for Link Authentication
and Encryption and HDCP 2.2 stream encryption
callback.

v2:
- Added a WARN_ON() instead of drm_err. [Uma]
- Cosmetic changes. [Uma]
v3:
- 's/port_data/hdcp_port_data' [Ram]
- skip redundant link check. [Ram]
v4:
- use pipe instead of port to access HDCP2_STREAM_STATUS

Cc: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Reviewed-by: Ramalingam C <ramalingam.c@intel.com>
Tested-by: Karthik B S <karthik.b.s@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210111081120.28417-18-anshuman.gupta@intel.com

drivers/gpu/drm/i915/display/intel_display_types.h

@@ -378,6 +378,10 @@ struct intel_hdcp_shim {
 	int (*config_stream_type)(struct intel_digital_port *dig_port,
 				  bool is_repeater, u8 type);
 
+	/* Enable/Disable HDCP 2.2 stream encryption on DP MST Transport Link */
+	int (*stream_2_2_encryption)(struct intel_connector *connector,
+				     bool enable);
+
 	/* HDCP2.2 Link Integrity Check */
 	int (*check_2_2_link)(struct intel_digital_port *dig_port,
 			      struct intel_connector *connector);

drivers/gpu/drm/i915/display/intel_dp_hdcp.c

@@ -698,18 +698,14 @@ intel_dp_mst_hdcp_stream_encryption(struct intel_connector *connector,
 	return 0;
 }
 
-static
-bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
-				  struct intel_connector *connector)
+static bool intel_dp_mst_get_qses_status(struct intel_digital_port *dig_port,
+					 struct intel_connector *connector)
 {
 	struct drm_i915_private *i915 = to_i915(dig_port->base.base.dev);
-	struct intel_dp *intel_dp = &dig_port->dp;
 	struct drm_dp_query_stream_enc_status_ack_reply reply;
+	struct intel_dp *intel_dp = &dig_port->dp;
 	int ret;
 
-	if (!intel_dp_hdcp_check_link(dig_port, connector))
-		return false;
-
 	ret = drm_dp_send_query_stream_enc_status(&intel_dp->mst_mgr,
 						  connector->port, &reply);
 	if (ret) {
@@ -726,6 +722,78 @@ bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
 	return reply.auth_completed && reply.encryption_enabled;
 }
 
+static
+bool intel_dp_mst_hdcp_check_link(struct intel_digital_port *dig_port,
+				  struct intel_connector *connector)
+{
+	if (!intel_dp_hdcp_check_link(dig_port, connector))
+		return false;
+
+	return intel_dp_mst_get_qses_status(dig_port, connector);
+}
+
+static int
+intel_dp_mst_hdcp2_stream_encryption(struct intel_connector *connector,
+				     bool enable)
+{
+	struct intel_digital_port *dig_port = intel_attached_dig_port(connector);
+	struct drm_i915_private *i915 = to_i915(connector->base.dev);
+	struct hdcp_port_data *data = &dig_port->hdcp_port_data;
+	struct intel_hdcp *hdcp = &connector->hdcp;
+	enum transcoder cpu_transcoder = hdcp->stream_transcoder;
+	enum pipe pipe = (enum pipe)cpu_transcoder;
+	enum port port = dig_port->base.port;
+	int ret;
+
+	drm_WARN_ON(&i915->drm, enable &&
+		    !!(intel_de_read(i915, HDCP2_AUTH_STREAM(i915, cpu_transcoder, port))
+		    & AUTH_STREAM_TYPE) != data->streams[0].stream_type);
+
+	ret = intel_dp_mst_toggle_hdcp_stream_select(connector, enable);
+	if (ret)
+		return ret;
+
+	/* Wait for encryption confirmation */
+	if (intel_de_wait_for_register(i915,
+				       HDCP2_STREAM_STATUS(i915, cpu_transcoder, pipe),
+				       STREAM_ENCRYPTION_STATUS,
+				       enable ? STREAM_ENCRYPTION_STATUS : 0,
+				       HDCP_ENCRYPT_STATUS_CHANGE_TIMEOUT_MS)) {
+		drm_err(&i915->drm, "Timed out waiting for transcoder: %s stream encryption %s\n",
+			transcoder_name(cpu_transcoder), enable ? "enabled" : "disabled");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+/*
+ * DP v2.0 I.3.3 ignore the stream signature L' in QSES reply msg reply.
+ * I.3.5 MST source device may use a QSES msg to query downstream status
+ * for a particular stream.
+ */
+static
+int intel_dp_mst_hdcp2_check_link(struct intel_digital_port *dig_port,
+				  struct intel_connector *connector)
+{
+	struct intel_hdcp *hdcp = &connector->hdcp;
+	int ret;
+
+	/*
+	 * We do need to do the Link Check only for the connector involved with
+	 * HDCP port authentication and encryption.
+	 * We can re-use the hdcp->is_repeater flag to know that the connector
+	 * involved with HDCP port authentication and encryption.
+	 */
+	if (hdcp->is_repeater) {
+		ret = intel_dp_hdcp2_check_link(dig_port, connector);
+		if (ret)
+			return ret;
+	}
+
+	return intel_dp_mst_get_qses_status(dig_port, connector) ? 0 : -EINVAL;
+}
+
 static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
 	.write_an_aksv = intel_dp_hdcp_write_an_aksv,
 	.read_bksv = intel_dp_hdcp_read_bksv,
@@ -739,7 +807,12 @@ static const struct intel_hdcp_shim intel_dp_mst_hdcp_shim = {
 	.stream_encryption = intel_dp_mst_hdcp_stream_encryption,
 	.check_link = intel_dp_mst_hdcp_check_link,
 	.hdcp_capable = intel_dp_hdcp_capable,
-
+	.write_2_2_msg = intel_dp_hdcp2_write_msg,
+	.read_2_2_msg = intel_dp_hdcp2_read_msg,
+	.config_stream_type = intel_dp_hdcp2_config_stream_type,
+	.stream_2_2_encryption = intel_dp_mst_hdcp2_stream_encryption,
+	.check_2_2_link = intel_dp_mst_hdcp2_check_link,
+	.hdcp_2_2_capable = intel_dp_hdcp2_capable,
 	.protocol = HDCP_PROTOCOL_DP,
 };