LibrePilot/flight/modules/ComUsbBridge/ComUsbBridge.c

/**
 ******************************************************************************
 * @addtogroup OpenPilotModules OpenPilot Modules
 * @{
 * @addtogroup ComUsbBridgeModule Com Port to USB VCP Bridge Module
 * @brief Bridge Com and USB VCP ports
 * @{
 *
 * @file       ComUsbBridge.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2011.
 * @brief      Bridges selected Com Port to the USB VCP emulated serial port
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

// ****************

#include <openpilot.h>

#include "taskinfo.h"

#include <stdbool.h>

#include <pios_board_io.h>

// ****************
// Private functions

static void com2UsbBridgeTask(void *parameters);
static void usb2ComBridgeTask(void *parameters);
static void usb2ComBridgeSetCtrlLine(uint32_t com_id, uint32_t mask, uint32_t state);
static void usb2ComBridgeSetBaudRate(uint32_t com_id, uint32_t baud);


// ****************
// Private constants

#define U2C_STACK_SIZE_BYTES 260
#define C2U_STACK_SIZE_BYTES 316

#define TASK_PRIORITY        (tskIDLE_PRIORITY + 1)

#define BRIDGE_BUF_LEN       10

// ****************
// Private variables

static xTaskHandle com2UsbBridgeTaskHandle;
static xTaskHandle usb2ComBridgeTaskHandle;

static uint8_t *com2usb_buf;
static uint8_t *usb2com_buf;

static uint32_t usart_port;
static uint32_t vcp_port;

static bool bridge_enabled = false;

/**
 * Initialise the module
 * \return -1 if initialisation failed
 * \return 0 on success
 */

static int32_t comUsbBridgeStart(void)
{
    if (bridge_enabled) {
        // Start tasks
        xTaskCreate(com2UsbBridgeTask, "Com2UsbBridge", C2U_STACK_SIZE_BYTES / 4, NULL, TASK_PRIORITY, &com2UsbBridgeTaskHandle);
        PIOS_TASK_MONITOR_RegisterTask(TASKINFO_RUNNING_COM2USBBRIDGE, com2UsbBridgeTaskHandle);
        xTaskCreate(usb2ComBridgeTask, "Usb2ComBridge", U2C_STACK_SIZE_BYTES / 4, NULL, TASK_PRIORITY, &usb2ComBridgeTaskHandle);
        PIOS_TASK_MONITOR_RegisterTask(TASKINFO_RUNNING_USB2COMBRIDGE, usb2ComBridgeTaskHandle);
        return 0;
    }

    return -1;
}
/**
 * Initialise the module
 * \return -1 if initialisation failed
 * \return 0 on success
 */
static int32_t comUsbBridgeInitialize(void)
{
    // TODO: Get from settings object
    usart_port = PIOS_COM_BRIDGE;
    vcp_port   = PIOS_COM_VCP;

    // Register the call back handler for USB control line changes to simply
    // pass these onto any handler registered on the USART
    if (vcp_port) {
        PIOS_COM_RegisterCtrlLineCallback(vcp_port,
                                          usb2ComBridgeSetCtrlLine,
                                          usart_port);
        PIOS_COM_RegisterBaudRateCallback(vcp_port,
                                          usb2ComBridgeSetBaudRate,
                                          usart_port);
    }

#ifdef MODULE_COMUSBBRIDGE_BUILTIN
    bridge_enabled = true;
#else

    if (usart_port && vcp_port) {
        bridge_enabled = true;
    } else {
        bridge_enabled = false;
    }
#endif

    if (bridge_enabled) {
        com2usb_buf = pios_malloc(BRIDGE_BUF_LEN);
        PIOS_Assert(com2usb_buf);
        usb2com_buf = pios_malloc(BRIDGE_BUF_LEN);
        PIOS_Assert(usb2com_buf);
    }

    return 0;
}
MODULE_INITCALL(comUsbBridgeInitialize, comUsbBridgeStart);

/**
 * Main task. It does not return.
 */

static void com2UsbBridgeTask(__attribute__((unused)) void *parameters)
{
    /* Handle usart -> vcp direction */
    volatile uint32_t tx_errors = 0;

    while (1) {
        uint32_t rx_bytes;

        rx_bytes = PIOS_COM_ReceiveBuffer(usart_port, com2usb_buf, BRIDGE_BUF_LEN, 500);
        if (rx_bytes > 0) {
            /* Bytes available to transfer */
            if (PIOS_COM_SendBuffer(vcp_port, com2usb_buf, rx_bytes) != (int32_t)rx_bytes) {
                /* Error on transmit */
                tx_errors++;
            }
        }
    }
}

static void usb2ComBridgeTask(__attribute__((unused)) void *parameters)
{
    /* Handle vcp -> usart direction */
    volatile uint32_t tx_errors = 0;

    while (1) {
        uint32_t rx_bytes;

        rx_bytes = PIOS_COM_ReceiveBuffer(vcp_port, usb2com_buf, BRIDGE_BUF_LEN, 500);
        if (rx_bytes > 0) {
            /* Bytes available to transfer */
            if (PIOS_COM_SendBuffer(usart_port, usb2com_buf, rx_bytes) != (int32_t)rx_bytes) {
                /* Error on transmit */
                tx_errors++;
            }
        }
    }
}

/* This routine is registered with the USB driver and will be called in the
 * event of a control line state change. It will then call down to the USART
 * driver to drive the required control line state.
 */
static void usb2ComBridgeSetCtrlLine(uint32_t com_id, uint32_t mask, uint32_t state)
{
    PIOS_COM_SetCtrlLine(com_id, mask, state);
}

static void usb2ComBridgeSetBaudRate(uint32_t com_id, uint32_t baud)
{
    PIOS_COM_ChangeBaud(com_id, baud);
}