main.c

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/*
 * ether2ser — Ethernet ↔ synchronous V.24 (RS-232/V.28) bridge
 *
 * File:    src/main.c
 * Purpose: Firmware entry point and high-level scheduler.
 *
 * This project targets the W55RP20-EVB-PICO (RP2040 + W5500). The RP2040 CPU
 * runs the control plane and protocol processing (L3 forwarding, framing/CRC,
 * buffering, configuration). The RP2040 PIO implements the time-critical
 * synchronous serial “PHY” (TXD/RXD with TXC/RXC).
 *
 * Notes:
 *  - USB CDC is used for a simple CLI and status output.
 *  - PIO programs live in /pio (top-level); PIO C glue lives in src/pio/.
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Copyright (c) 2026 Florian <f.leuze@outlook.de>
 */
 
// Related headers
#include "system/app_context.h"
 
// Standard library headers
#include <stdbool.h>
#include <stdio.h>
 
// Library Headers
#include "hardware/gpio.h"
#include "hardware/pio.h"
#include "hardware/sync.h"
#include "hardware/watchdog.h"
#include "pico/multicore.h"
#include "pico/stdio.h"
#include "pico/time.h"
 
// Project Headers
#include "drivers/gpio_driver.h"
#include "drivers/pio_tx_rx_driver.h"
#include "drivers/tx_queue.h"
#include "drivers/w5500_driver.h"
#include "platform/pinmap.h"
#include "system/baudrate_monitor.h"
#include "system/common.h"
#include "system/error.h"
#include "system/event_loop.h"
#include "system/event_queue.h"
#include "system/persistent_config.h"
#include "version.h"
 
// Generated headers
 
// USB CDC enumeration delay in milliseconds
#define USB_ENUMERATION_DELAY_MS 1500
#define GLOBAL_WATCHDOG_TIMEOUT_MS 5000
#define WATCHDOG_DISABLED_FOR_DEBUGGING 1
 
static void core1_entry(void)
{
    __sev();
    __wfe();
    __wfe();
    while (true)
    {
        log_core1_drain();
        __wfe(); // sleep until interrupt/event, minimal contention
    }
}
 
int main(void)
{
    e2s_error_t err;
 
    // Application Context
    static app_ctx_t app_context = {0};
 
    // Config variables
    config_t persistent_config;
 
    // Initialize USB CDC
    stdio_init_all();
 
    // Give the USB CDC a moment to enumerate (harmless even if not using USB)
    sleep_ms(USB_ENUMERATION_DELAY_MS);
 
    // Initialize W5500
    w5500_driver_init();
    // Initialize GPIOs
    init_pins();
 
    if (config_is_valid())
    {
        app_context.config_valid = config_read(&persistent_config);
    }
    else
    {
        app_context.config_valid = false;
    }
 
    init_app(&app_context, &persistent_config);
 
    if ((err = w5500_open_udp_socket(&app_context.local_config)) != E2S_OK)
    {
        fatal_panic(err);
    }
    w5500_debug_status();
 
    // Initialize TX Queue
    tx_queue_init(&app_context.tx_queue, app_context.tx_queue_buffer);
 
    // Initialize PIO
    // Currently anything faster than 38400 is not supported
    tx_clock_init(pio0, 0, &app_context.v24_config);
    rx_clock_init(pio0, 1, &(app_context.v24_config.polarities.rx_polarities));
    baudrate_estimator_init(V24_RXC);
    if (app_context.v24_config.external_clock)
    {
        baudrate_estimator_init(V24_TXC_DCE);
    }
 
    // Enable watchdog, 5s timeout, disabled in debugging
    watchdog_enable(GLOBAL_WATCHDOG_TIMEOUT_MS, WATCHDOG_DISABLED_FOR_DEBUGGING);
 
    LOG_PLAIN("\r\nv24-eth-bridge: hello from RP2040\r\n");
    LOG_PLAIN("\r\nType 'help' in USB serial.\r\n");
    LOG_PLAIN("Version: %s\r\n", VERSION_STRING);
 
    if (get_loglevel() == LOG_LEVEL_DEBUG)
    {
        LOG_PLAIN("\r\nDebug logging enabled.\r\n> ");
        dump_config();
        app_context.need_prompt = true;
    }
    multicore_launch_core1(core1_entry);
 
    // Initialize event queue finally
    event_queue_init();
 
    // Indicate DTE is present just before we enter the event loop
    gpio_put(V24_DTR, 1);
 
    event_loop(&app_context);
}