drm/amd/display: Add CP_IRQ clear capability

[Why]
Currently we do not clear the CP_IRQ bit upon receiving it.

[How]
Added a function to clear CP_IRQ bit.
Signed-off-by: NHarmanprit Tatla <harmanprit.tatla@amd.com>
Acked-by: NAurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/modules/hdcp/hdcp.c

@@ -470,6 +470,15 @@ enum mod_hdcp_status mod_hdcp_process_event(struct mod_hdcp *hdcp,
 		if (reset_status != MOD_HDCP_STATUS_SUCCESS)
 			push_error_status(hdcp, reset_status);
 	}
+
+	/* Clear CP_IRQ status if needed */
+	if (event_ctx.event == MOD_HDCP_EVENT_CPIRQ &&
+			event_ctx.unexpected_event == 0) {
+		status = mod_hdcp_clear_cp_irq_status(hdcp);
+		if (status != MOD_HDCP_STATUS_SUCCESS)
+			push_error_status(hdcp, status);
+	}
+
 	return status;
 }
 

drivers/gpu/drm/amd/display/modules/hdcp/hdcp.h

@@ -386,6 +386,7 @@ enum mod_hdcp_status mod_hdcp_write_eks(struct mod_hdcp *hdcp);
 enum mod_hdcp_status mod_hdcp_write_repeater_auth_ack(struct mod_hdcp *hdcp);
 enum mod_hdcp_status mod_hdcp_write_stream_manage(struct mod_hdcp *hdcp);
 enum mod_hdcp_status mod_hdcp_write_content_type(struct mod_hdcp *hdcp);
+enum mod_hdcp_status mod_hdcp_clear_cp_irq_status(struct mod_hdcp *hdcp);
 
 /* hdcp version helpers */
 static inline uint8_t is_dp_hdcp(struct mod_hdcp *hdcp)

drivers/gpu/drm/amd/display/modules/hdcp/hdcp_ddc.c

@@ -645,3 +645,22 @@ enum mod_hdcp_status mod_hdcp_write_content_type(struct mod_hdcp *hdcp)
 		status = MOD_HDCP_STATUS_INVALID_OPERATION;
 	return status;
 }
+
+enum mod_hdcp_status mod_hdcp_clear_cp_irq_status(struct mod_hdcp *hdcp)
+{
+	uint8_t clear_cp_irq_bit = 2;
+	uint32_t size = 1;
+
+	if (is_dp_hdcp(hdcp)) {
+		if (hdcp->connection.link.dp.rev >= 0x14)
+			return hdcp->config.ddc.funcs.write_dpcd(hdcp->config.ddc.handle,
+					DP_DEVICE_SERVICE_IRQ_VECTOR_ESI0, &clear_cp_irq_bit, size)
+					? MOD_HDCP_STATUS_SUCCESS : MOD_HDCP_STATUS_DDC_FAILURE;
+		else
+			return hdcp->config.ddc.funcs.write_dpcd(hdcp->config.ddc.handle,
+					DP_DEVICE_SERVICE_IRQ_VECTOR, &clear_cp_irq_bit, size)
+					? MOD_HDCP_STATUS_SUCCESS : MOD_HDCP_STATUS_DDC_FAILURE;
+	}
+
+	return MOD_HDCP_STATUS_INVALID_OPERATION;
+}