uart_win32.c

/*
 * Generic uart / rs232/ serial port library
 *
 * Copyright (c) 2013, Roel Verdult
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the
 * names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @file uart_win32.c
 *
 * Note: the win32 version of this library has also been seen under the GPLv3+
 * license as part of the libnfc project, which appears to have additional
 * contributors.
 *
 * This version of the library has functionality removed which was not used by
 * proxmark3 project.
 */

#include "uart.h"

#include <stdio.h>
#include <stdint.h>
#include <stdbool.h>


// The windows serial port implementation
#ifdef _WIN32
#include <windows.h>

typedef struct {
	HANDLE hPort;     // Serial port handle
	DCB dcb;          // Device control settings
	COMMTIMEOUTS ct;  // Serial port time-out configuration
} serial_port_windows;


void upcase(char *p) {
	while(*p != '\0') {
		if(*p >= 97 && *p <= 122) {
			*p -= 32;
		}
		++p;
	}
}


void uart_close(const serial_port sp) {
	CloseHandle(((serial_port_windows*)sp)->hPort);
	free(sp);
}


serial_port uart_open(const char* pcPortName) {
	char acPortName[255];
	serial_port_windows* sp = malloc(sizeof(serial_port_windows));

	// Copy the input "com?" to "\\.\COM?" format
	sprintf(acPortName,"\\\\.\\%s",pcPortName);
	upcase(acPortName);

	// Try to open the serial port
	sp->hPort = CreateFileA(acPortName, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, 0, NULL);
	if (sp->hPort == INVALID_HANDLE_VALUE) {
		uart_close(sp);
		return INVALID_SERIAL_PORT;
	}

	// Prepare the device control
	memset(&sp->dcb, 0, sizeof(DCB));
	sp->dcb.DCBlength = sizeof(DCB);
	if (!BuildCommDCBA("baud=9600 data=8 parity=N stop=1",&sp->dcb)) {
		uart_close(sp);
		return INVALID_SERIAL_PORT;
	}

	// Update the active serial port
	if (!SetCommState(sp->hPort,&sp->dcb)) {
		uart_close(sp);
		return INVALID_SERIAL_PORT;
	}

	sp->ct.ReadIntervalTimeout         = 0;
	sp->ct.ReadTotalTimeoutMultiplier  = 0;
	sp->ct.ReadTotalTimeoutConstant    = 30;
	sp->ct.WriteTotalTimeoutMultiplier = 0;
	sp->ct.WriteTotalTimeoutConstant   = 30;

	if (!SetCommTimeouts(sp->hPort, &sp->ct)) {
		uart_close(sp);
		return INVALID_SERIAL_PORT;
	}

	PurgeComm(sp->hPort, PURGE_RXABORT | PURGE_RXCLEAR);

	return sp;
}


bool uart_receive(const serial_port sp, uint8_t *pbtRx, size_t pszMaxRxLen, size_t *pszRxLen) {
	return ReadFile(((serial_port_windows*)sp)->hPort, pbtRx, pszMaxRxLen, (LPDWORD)pszRxLen, NULL);
}


bool uart_send(const serial_port sp, const uint8_t* pbtTx, const size_t szTxLen) {
	DWORD dwTxLen = 0;
	return WriteFile(((serial_port_windows*)sp)->hPort, pbtTx, szTxLen, &dwTxLen, NULL);
}


bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) {
	serial_port_windows* spw;
	spw = (serial_port_windows*)sp;
	spw->dcb.BaudRate = uiPortSpeed;
	return SetCommState(spw->hPort, &spw->dcb);
}


uint32_t uart_get_speed(const serial_port sp) {
	const serial_port_windows* spw = (serial_port_windows*)sp;
	if (!GetCommState(spw->hPort, (serial_port)&spw->dcb)) {
		return spw->dcb.BaudRate;
	}
	return 0;
}

#endif