The problem with i.MX8MQ HDCP is as follows:
1.How to turn on HDCP?
2.Whether HDCP requires a key?
Refer to the data sheet, not all of imx8mq part number can support this feature, if your chip can support this, as I known, current bsp can support this, HDCP could be enabled by the command in iMX8MQ.
modetest -M imx-dcss -w 48:"Content Protection":1