HDCP:

ME FW as a security engine provides the capability for setting up HDCP2.2 protocol negotiation between the Intel graphics device and an HDC2.2 sink.

ME FW prepares HDCP2.2 negotiation parameters, signs and encrypts them according the HDCP 2.2 spec. The Intel graphics sends the created blob to the HDCP2.2 sink.

Similarly, the HDCP2.2 sink’s response is transferred to ME FW for decryption and verification.

Once all the steps of HDCP2.2 negotiation are completed, upon request ME FW will configure the port as authenticated and supply the HDCP encryption keys to Intel graphics hardware.

mei_hdcp driver

The mei_hdcp driver acts as a translation layer between HDCP 2.2 protocol implementer (I915) and ME FW by translating HDCP2.2 negotiation messages to ME FW command payloads and vice versa.

mei_hdcp api

int mei_hdcp_initiate_session(struct device *dev, struct hdcp_port_data *data, struct hdcp2_ake_init *ake_data)

Initiate a Wired HDCP2.2 Tx Session in ME FW

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_ake_init *ake_data

AKE_Init msg output.

Return

0 on Success, <0 on Failure.

int mei_hdcp_verify_receiver_cert_prepare_km(struct device *dev, struct hdcp_port_data *data, struct hdcp2_ake_send_cert *rx_cert, bool *km_stored, struct hdcp2_ake_no_stored_km *ek_pub_km, size_t *msg_sz)

Verify the Receiver Certificate AKE_Send_Cert and prepare AKE_Stored_Km/AKE_No_Stored_Km

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_ake_send_cert *rx_cert

AKE_Send_Cert for verification

bool *km_stored

Pairing status flag output

struct hdcp2_ake_no_stored_km *ek_pub_km

AKE_Stored_Km/AKE_No_Stored_Km output msg

size_t *msg_sz

size of AKE_XXXXX_Km output msg

Return

0 on Success, <0 on Failure

int mei_hdcp_verify_hprime(struct device *dev, struct hdcp_port_data *data, struct hdcp2_ake_send_hprime *rx_hprime)

Verify AKE_Send_H_prime at ME FW.

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_ake_send_hprime *rx_hprime

AKE_Send_H_prime msg for ME FW verification

Return

0 on Success, <0 on Failure

int mei_hdcp_store_pairing_info(struct device *dev, struct hdcp_port_data *data, struct hdcp2_ake_send_pairing_info *pairing_info)

Store pairing info received at ME FW

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_ake_send_pairing_info *pairing_info

AKE_Send_Pairing_Info msg input to ME FW

Return

0 on Success, <0 on Failure

int mei_hdcp_initiate_locality_check(struct device *dev, struct hdcp_port_data *data, struct hdcp2_lc_init *lc_init_data)

Prepare LC_Init

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_lc_init *lc_init_data

LC_Init msg output

Return

0 on Success, <0 on Failure

int mei_hdcp_verify_lprime(struct device *dev, struct hdcp_port_data *data, struct hdcp2_lc_send_lprime *rx_lprime)

Verify lprime.

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_lc_send_lprime *rx_lprime

LC_Send_L_prime msg for ME FW verification

Return

0 on Success, <0 on Failure

int mei_hdcp_get_session_key(struct device *dev, struct hdcp_port_data *data, struct hdcp2_ske_send_eks *ske_data)

Prepare SKE_Send_Eks.

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_ske_send_eks *ske_data

SKE_Send_Eks msg output from ME FW.

Return

0 on Success, <0 on Failure

int mei_hdcp_repeater_check_flow_prepare_ack(struct device *dev, struct hdcp_port_data *data, struct hdcp2_rep_send_receiverid_list *rep_topology, struct hdcp2_rep_send_ack *rep_send_ack)

Validate the Downstream topology and prepare rep_ack.

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_rep_send_receiverid_list *rep_topology

Receiver ID List to be validated

struct hdcp2_rep_send_ack *rep_send_ack

repeater ack from ME FW.

Return

0 on Success, <0 on Failure

int mei_hdcp_verify_mprime(struct device *dev, struct hdcp_port_data *data, struct hdcp2_rep_stream_ready *stream_ready)

Verify mprime.

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

struct hdcp2_rep_stream_ready *stream_ready

RepeaterAuth_Stream_Ready msg for ME FW verification.

Return

0 on Success, <0 on Failure

int mei_hdcp_enable_authentication(struct device *dev, struct hdcp_port_data *data)

Mark a port as authenticated through ME FW

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

Return

0 on Success, <0 on Failure

int mei_hdcp_close_session(struct device *dev, struct hdcp_port_data *data)

Close the Wired HDCP Tx session of ME FW per port. This also disables the authenticated state of the port.

Parameters

struct device *dev

device corresponding to the mei_cl_device

struct hdcp_port_data *data

Intel HW specific hdcp data

Return

0 on Success, <0 on Failure

int mei_hdcp_component_match(struct device *dev, int subcomponent, void *data)

compare function for matching mei hdcp.

Parameters

struct device *dev

master device

int subcomponent

subcomponent to match (I915_COMPONENT_HDCP)

void *data

compare data (mei hdcp device)

Description

The function checks if the driver is i915, the subcomponent is HDCP and the grand parent of hdcp and the parent of i915 are the same PCH device.

Return

• 1 - if components match
• 0 - otherwise