/* SPDX-License-Identifier: MIT */
/* Copyright © 2024 Intel Corporation */

#ifndef __INTEL_HDCP_SHIM_H__
#define __INTEL_HDCP_SHIM_H__

#include <linux/types.h>

#include <drm/intel/i915_hdcp_interface.h>

enum transcoder;
struct intel_connector;
struct intel_digital_port;

enum check_link_response {
        HDCP_LINK_PROTECTED     = 0,
        HDCP_TOPOLOGY_CHANGE,
        HDCP_LINK_INTEGRITY_FAILURE,
        HDCP_REAUTH_REQUEST
};

/*
 * This structure serves as a translation layer between the generic HDCP code
 * and the bus-specific code. What that means is that HDCP over HDMI differs
 * from HDCP over DP, so to account for these differences, we need to
 * communicate with the receiver through this shim.
 *
 * For completeness, the 2 buses differ in the following ways:
 *      - DP AUX vs. DDC
 *              HDCP registers on the receiver are set via DP AUX for DP, and
 *              they are set via DDC for HDMI.
 *      - Receiver register offsets
 *              The offsets of the registers are different for DP vs. HDMI
 *      - Receiver register masks/offsets
 *              For instance, the ready bit for the KSV fifo is in a different
 *              place on DP vs HDMI
 *      - Receiver register names
 *              Seriously. In the DP spec, the 16-bit register containing
 *              downstream information is called BINFO, on HDMI it's called
 *              BSTATUS. To confuse matters further, DP has a BSTATUS register
 *              with a completely different definition.
 *      - KSV FIFO
 *              On HDMI, the ksv fifo is read all at once, whereas on DP it must
 *              be read 3 keys at a time
 *      - Aksv output
 *              Since Aksv is hidden in hardware, there's different procedures
 *              to send it over DP AUX vs DDC
 */
struct intel_hdcp_shim {
        /* Outputs the transmitter's An and Aksv values to the receiver. */
        int (*write_an_aksv)(struct intel_digital_port *dig_port, u8 *an);

        /* Reads the receiver's key selection vector */
        int (*read_bksv)(struct intel_digital_port *dig_port, u8 *bksv);

        /*
         * Reads BINFO from DP receivers and BSTATUS from HDMI receivers. The
         * definitions are the same in the respective specs, but the names are
         * different. Call it BSTATUS since that's the name the HDMI spec
         * uses and it was there first.
         */
        int (*read_bstatus)(struct intel_digital_port *dig_port,
                            u8 *bstatus);

        /* Determines whether a repeater is present downstream */
        int (*repeater_present)(struct intel_digital_port *dig_port,
                                bool *repeater_present);

        /* Reads the receiver's Ri' value */
        int (*read_ri_prime)(struct intel_digital_port *dig_port, u8 *ri);

        /* Determines if the receiver's KSV FIFO is ready for consumption */
        int (*read_ksv_ready)(struct intel_digital_port *dig_port,
                              bool *ksv_ready);

        /* Reads the ksv fifo for num_downstream devices */
        int (*read_ksv_fifo)(struct intel_digital_port *dig_port,
                             int num_downstream, u8 *ksv_fifo);

        /* Reads a 32-bit part of V' from the receiver */
        int (*read_v_prime_part)(struct intel_digital_port *dig_port,
                                 int i, u32 *part);

        /* Enables HDCP signalling on the port */
        int (*toggle_signalling)(struct intel_digital_port *dig_port,
                                 enum transcoder cpu_transcoder,
                                 bool enable);

        /* Enable/Disable stream encryption on DP MST Transport Link */
        int (*stream_encryption)(struct intel_connector *connector,
                                 bool enable);

        /* Ensures the link is still protected */
        bool (*check_link)(struct intel_digital_port *dig_port,
                           struct intel_connector *connector);

        /* Detects panel's hdcp capability. This is optional for HDMI. */
        int (*hdcp_get_capability)(struct intel_digital_port *dig_port,
                                   bool *hdcp_capable);

        /* HDCP adaptation(DP/HDMI) required on the port */
        enum hdcp_wired_protocol protocol;

        /* Detects whether sink is HDCP2.2 capable */
        int (*hdcp_2_2_get_capability)(struct intel_connector *connector,
                                       bool *capable);

        /* Write HDCP2.2 messages */
        int (*write_2_2_msg)(struct intel_connector *connector,
                             void *buf, size_t size);

        /* Read HDCP2.2 messages */
        int (*read_2_2_msg)(struct intel_connector *connector,
                            u8 msg_id, void *buf, size_t size);

        /*
         * Implementation of DP HDCP2.2 Errata for the communication of stream
         * type to Receivers. In DP HDCP2.2 Stream type is one of the input to
         * the HDCP2.2 Cipher for En/De-Cryption. Not applicable for HDMI.
         */
        int (*config_stream_type)(struct intel_connector *connector,
                                  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);

        /* HDCP remote sink cap */
        int (*get_remote_hdcp_capability)(struct intel_connector *connector,
                                          bool *hdcp_capable, bool *hdcp2_capable);
};

#endif /* __INTEL_HDCP_SHIM_H__ */