port_mailbox.h

// Copyright 2021-2025 The Aerospace Corporation.
// This file is a part of SatCat5, licensed under CERN-OHL-W v2 or later.
// Driver for the internal "MailBox" Ethernet port
 
#pragma once
 
#include <satcat5/cfgbus_interrupt.h>
#include <satcat5/io_buffer.h>
 
// Default size parameters:
// (Must be large enough for one full-size Ethernet frame + metadata,
//  larger sizes are fine if you have the memory for it.)
#ifndef SATCAT5_MAILBOX_BUFFSIZE
#define SATCAT5_MAILBOX_BUFFSIZE    1600    // Buffer size in bytes
#endif
 
#ifndef SATCAT5_MAILBOX_BUFFPKT
#define SATCAT5_MAILBOX_BUFFPKT     32      // Maximum packets per buffer
#endif
 
namespace satcat5 {
    namespace port {
        class Mailbox
            : public    satcat5::io::BufferedIO
            , protected satcat5::cfg::Interrupt
        {
        public:
            Mailbox(satcat5::cfg::ConfigBus* cfg, unsigned devaddr, unsigned regaddr);
 
        private:
            // Event handlers.
            void data_rcvd(satcat5::io::Readable* src) override;
            void irq_event() override;
 
            // Copy of contiguous segment of transmit data from the Tx buffer.
            // Returns the number of bytes copied.
            u32 copy_tx_segment();
 
            // Copy a contiguous segment of received data to Rx buffer.
            // Returns last reading from hardware status register.
            u32 copy_rx_segment();
 
            // Pointer to the hardware control register.
            satcat5::cfg::Register m_hw_reg;
 
            // Raw Tx/Rx working buffers for BufferedIO.
            u8 m_txbuff[SATCAT5_MAILBOX_BUFFSIZE];
            u8 m_rxbuff[SATCAT5_MAILBOX_BUFFSIZE];
        };
    }
}