libnfc/libnfc/buses/uart.c
2010-10-22 14:25:09 +00:00

441 lines
11 KiB
C

/*-
* Public platform independent Near Field Communication (NFC) library
*
* Copyright (C) 2009, 2010, Roel Verdult, Romuald Conty
*
* This program is free software: you can redistribute it and/or modify it
* under the terms of the GNU Lesser 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 Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>
*
*/
/**
* @file uart.c
* @brief UART driver
*
* This file contains 2 implementations of UART driver: first for POSIX systems, second for Windows system.
*/
/*
Based on RS232 code written by Teunis van Beelen available:
http://www.teuniz.net/RS-232/index.html
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif // HAVE_CONFIG_H
#include "uart.h"
#include <nfc/nfc.h>
#include <nfc/nfc-messages.h>
// Test if we are dealing with unix operating systems
#ifndef _WIN32
# include <sys/select.h>
# include <termios.h>
typedef struct termios term_info;
typedef struct {
int fd; // Serial port file descriptor
term_info tiOld; // Terminal info before using the port
term_info tiNew; // Terminal info during the transaction
} serial_port_unix;
// timeval struct that define timeout delay for serial port
static struct timeval default_timeout = {
.tv_sec = 0, // 0 second
.tv_usec = 60000 // 60 ms
};
// Work-around to claim uart interface using the c_iflag (software input processing) from the termios struct
# define CCLAIMED 0x80000000
serial_port
uart_open (const char *pcPortName)
{
serial_port_unix *sp = malloc (sizeof (serial_port_unix));
if (sp == 0)
return INVALID_SERIAL_PORT;
sp->fd = open (pcPortName, O_RDWR | O_NOCTTY | O_NONBLOCK);
if (sp->fd == -1) {
uart_close (sp);
return INVALID_SERIAL_PORT;
}
if (tcgetattr (sp->fd, &sp->tiOld) == -1) {
uart_close (sp);
return INVALID_SERIAL_PORT;
}
// Make sure the port is not claimed already
if (sp->tiOld.c_iflag & CCLAIMED) {
uart_close (sp);
return CLAIMED_SERIAL_PORT;
}
// Copy the old terminal info struct
sp->tiNew = sp->tiOld;
sp->tiNew.c_cflag = CS8 | CLOCAL | CREAD;
sp->tiNew.c_iflag = CCLAIMED | IGNPAR;
sp->tiNew.c_oflag = 0;
sp->tiNew.c_lflag = 0;
sp->tiNew.c_cc[VMIN] = 0; // block until n bytes are received
sp->tiNew.c_cc[VTIME] = 0; // block until a timer expires (n * 100 mSec.)
if (tcsetattr (sp->fd, TCSANOW, &sp->tiNew) == -1) {
uart_close (sp);
return INVALID_SERIAL_PORT;
}
tcflush (sp->fd, TCIFLUSH);
return sp;
}
// TODO Remove PN53x related timeout
#define UART_TIMEOUT(X) ((X * 7) + 15000) // 1-byte duration (µs) * 6+1 bytes (ACK + 1 other chance) + 15 ms (PN532 Tmax to reply ACK)
void
uart_set_speed (serial_port sp, const uint32_t uiPortSpeed)
{
long int iTimeout = UART_TIMEOUT(uiPortSpeed/9); // 8,n,1 => 9bits => ~ bauds/9
DBG ("Serial port speed requested to be set to %d bauds (%ld µs).", uiPortSpeed, iTimeout);
const serial_port_unix *spu = (serial_port_unix *) sp;
// Portability note: on some systems, B9600 != 9600 so we have to do
// uint32_t <=> speed_t associations by hand.
speed_t stPortSpeed = B9600;
switch (uiPortSpeed) {
case 9600:
stPortSpeed = B9600;
break;
case 19200:
stPortSpeed = B19200;
break;
case 38400:
stPortSpeed = B38400;
break;
# ifdef B57600
case 57600:
stPortSpeed = B57600;
break;
# endif
# ifdef B115200
case 115200:
stPortSpeed = B115200;
break;
# endif
# ifdef B230400
case 230400:
stPortSpeed = B230400;
break;
# endif
# ifdef B460800
case 460800:
stPortSpeed = B460800;
break;
# endif
default:
ERR ("Unable to set serial port speed to %d bauds. Speed value must be one of those defined in termios(3).",
uiPortSpeed);
return;
};
// Set default timeout
default_timeout.tv_usec = iTimeout;
// Set port speed (Input and Output)
cfsetispeed ((struct termios *) &(spu->tiNew), stPortSpeed);
cfsetospeed ((struct termios *) &(spu->tiNew), stPortSpeed);
if (tcsetattr (spu->fd, TCSADRAIN, &(spu->tiNew)) == -1) {
ERR ("%s", "Unable to apply new speed settings.");
}
}
uint32_t
uart_get_speed (serial_port sp)
{
uint32_t uiPortSpeed = 0;
const serial_port_unix *spu = (serial_port_unix *) sp;
switch (cfgetispeed (&spu->tiNew)) {
case B9600:
uiPortSpeed = 9600;
break;
case B19200:
uiPortSpeed = 19200;
break;
case B38400:
uiPortSpeed = 38400;
break;
# ifdef B57600
case B57600:
uiPortSpeed = 57600;
break;
# endif
# ifdef B115200
case B115200:
uiPortSpeed = 115200;
break;
# endif
# ifdef B230400
case B230400:
uiPortSpeed = 230400;
break;
# endif
# ifdef B460800
case B460800:
uiPortSpeed = 460800;
break;
# endif
}
return uiPortSpeed;
}
void
uart_close (const serial_port sp)
{
if (((serial_port_unix *) sp)->fd >= 0) {
tcsetattr (((serial_port_unix *) sp)->fd, TCSANOW, &((serial_port_unix *) sp)->tiOld);
close (((serial_port_unix *) sp)->fd);
}
free (sp);
}
/**
* @brief Receive data from UART and copy data to \a pbtRx
*
* @return 0 on success, otherwise driver error code
*/
int
uart_receive (serial_port sp, byte_t * pbtRx, size_t * pszRx)
{
int res;
int byteCount;
fd_set rfds;
struct timeval tv;
// Reset the output count
*pszRx = 0;
do {
// Reset file descriptor
FD_ZERO (&rfds);
FD_SET (((serial_port_unix *) sp)->fd, &rfds);
tv = default_timeout;
res = select (((serial_port_unix *) sp)->fd + 1, &rfds, NULL, NULL, &tv);
// Read error
if (res < 0) {
DBG ("%s", "RX error.");
return DEIO;
}
// Read time-out
if (res == 0) {
if (*pszRx == 0) {
// Error, we received no data
DBG ("RX time-out (%ld µs), buffer empty.", default_timeout.tv_usec);
return DETIMEOUT;
} else {
// We received some data, but nothing more is available
return 0;
}
}
// Retrieve the count of the incoming bytes
res = ioctl (((serial_port_unix *) sp)->fd, FIONREAD, &byteCount);
if (res < 0) {
return DEIO;
}
// There is something available, read the data
res = read (((serial_port_unix *) sp)->fd, pbtRx + (*pszRx), byteCount);
// Stop if the OS has some troubles reading the data
if (res <= 0) {
return DEIO;
}
*pszRx += res;
} while (byteCount);
return 0;
}
/**
* @brief Send \a pbtTx content to UART
*
* @return 0 on success, otherwise a driver error is returned
*/
int
uart_send (serial_port sp, const byte_t * pbtTx, const size_t szTx)
{
int32_t res;
size_t szPos = 0;
fd_set rfds;
struct timeval tv;
while (szPos < szTx) {
// Reset file descriptor
FD_ZERO (&rfds);
FD_SET (((serial_port_unix *) sp)->fd, &rfds);
tv = default_timeout;
res = select (((serial_port_unix *) sp)->fd + 1, NULL, &rfds, NULL, &tv);
// Write error
if (res < 0) {
DBG ("%s", "TX error.");
return DEIO;
}
// Write time-out
if (res == 0) {
DBG ("%s", "TX time-out.");
return DETIMEOUT;
}
// Send away the bytes
res = write (((serial_port_unix *) sp)->fd, pbtTx + szPos, szTx - szPos);
// Stop if the OS has some troubles sending the data
if (res <= 0) {
return DEIO;
}
szPos += res;
}
return 0;
}
#else
// The windows serial port implementation
typedef struct {
HANDLE hPort; // Serial port handle
DCB dcb; // Device control settings
COMMTIMEOUTS ct; // Serial port time-out configuration
} serial_port_windows;
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);
_strupr (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;
}
void
uart_close (const serial_port sp)
{
if (((serial_port_windows *) sp)->hPort != INVALID_HANDLE_VALUE) {
CloseHandle (((serial_port_windows *) sp)->hPort);
}
free (sp);
}
void
uart_set_speed (serial_port sp, const uint32_t uiPortSpeed)
{
serial_port_windows *spw;
DBG ("Serial port speed requested to be set to %d bauds.", uiPortSpeed);
// Set port speed (Input and Output)
switch (uiPortSpeed) {
case 9600:
case 19200:
case 38400:
case 57600:
case 115200:
case 230400:
case 460800:
break;
default:
ERR
("Unable to set serial port speed to %d bauds. Speed value must be one of these constants: 9600 (default), 19200, 38400, 57600, 115200, 230400 or 460800.",
uiPortSpeed);
};
spw = (serial_port_windows *) sp;
spw->dcb.BaudRate = uiPortSpeed;
if (!SetCommState (spw->hPort, &spw->dcb)) {
ERR ("Unable to apply new speed settings.");
}
}
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;
}
int
uart_receive (serial_port sp, byte_t * pbtRx, size_t * pszRx)
{
if (!ReadFile (((serial_port_windows *) sp)->hPort, pbtRx, *pszRx, (LPDWORD) pszRx, NULL)) {
return DEIO;
}
if (!*pszRx)
return DEIO;
return 0;
}
int
uart_send (serial_port sp, const byte_t * pbtTx, const size_t szTx)
{
DWORD dwTxLen = 0;
if (!WriteFile (((serial_port_windows *) sp)->hPort, pbtTx, szTx, &dwTxLen, NULL)) {
return DEIO;
}
if (!dwTxLen)
return DEIO;
return 0;
}
#endif /* _WIN32 */