mirror of https://gerrit.osmocom.org/libosmocore
280 lines
6.4 KiB
C
280 lines
6.4 KiB
C
/*! \file serial.c
|
|
* Utility functions to deal with serial ports */
|
|
/*
|
|
* Copyright (C) 2011 Sylvain Munaut <tnt@246tNt.com>
|
|
*
|
|
* All Rights Reserved
|
|
*
|
|
* SPDX-License-Identifier: GPL-2.0+
|
|
*
|
|
* 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 2 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.
|
|
*/
|
|
|
|
/*! \addtogroup serial
|
|
* @{
|
|
* Osmocom serial port helpers
|
|
*
|
|
* \file serial.c */
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <stdio.h>
|
|
#include <termios.h>
|
|
#include <unistd.h>
|
|
#include <sys/ioctl.h>
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#ifdef __linux__
|
|
#include <linux/serial.h>
|
|
#endif
|
|
|
|
#include <osmocom/core/serial.h>
|
|
|
|
|
|
#if 0
|
|
# define dbg_perror(x) perror(x)
|
|
#else
|
|
# define dbg_perror(x) do { } while (0)
|
|
#endif
|
|
|
|
/*! Open serial device and does base init
|
|
* \param[in] dev Path to the device node to open
|
|
* \param[in] baudrate Baudrate constant (speed_t: B9600, B...)
|
|
* \returns >=0 file descriptor in case of success or negative errno.
|
|
*/
|
|
int
|
|
osmo_serial_init(const char *dev, speed_t baudrate)
|
|
{
|
|
int rc, fd=-1, v24, flags;
|
|
struct termios tio;
|
|
|
|
/* Use nonblock as the device might block otherwise */
|
|
fd = open(dev, O_RDWR | O_NOCTTY | O_SYNC | O_NONBLOCK);
|
|
if (fd < 0) {
|
|
dbg_perror("open");
|
|
return -errno;
|
|
}
|
|
|
|
/* now put it into blocking mode */
|
|
flags = fcntl(fd, F_GETFL, 0);
|
|
if (flags < 0) {
|
|
dbg_perror("fcntl get flags");
|
|
rc = -errno;
|
|
goto error;
|
|
}
|
|
|
|
flags &= ~O_NONBLOCK;
|
|
rc = fcntl(fd, F_SETFL, flags);
|
|
if (rc != 0) {
|
|
dbg_perror("fcntl set flags");
|
|
rc = -errno;
|
|
goto error;
|
|
}
|
|
|
|
/* Configure serial interface */
|
|
rc = tcgetattr(fd, &tio);
|
|
if (rc < 0) {
|
|
dbg_perror("tcgetattr()");
|
|
rc = -errno;
|
|
goto error;
|
|
}
|
|
|
|
if (cfsetispeed(&tio, baudrate) < 0)
|
|
dbg_perror("cfsetispeed()");
|
|
if (cfsetospeed(&tio, baudrate) < 0)
|
|
dbg_perror("cfsetospeed()");
|
|
|
|
tio.c_cflag &= ~(PARENB | CSTOPB | CSIZE | CRTSCTS);
|
|
tio.c_cflag |= (CREAD | CLOCAL | CS8);
|
|
tio.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
|
|
tio.c_iflag |= (INPCK);
|
|
tio.c_iflag &= ~(ISTRIP | IXON | IXOFF | IGNBRK | INLCR | ICRNL | IGNCR);
|
|
tio.c_oflag &= ~(OPOST | ONLCR);
|
|
|
|
rc = tcsetattr(fd, TCSANOW, &tio);
|
|
if (rc < 0) {
|
|
dbg_perror("tcsetattr()");
|
|
rc = -errno;
|
|
goto error;
|
|
}
|
|
|
|
/* Set ready to read/write */
|
|
v24 = TIOCM_DTR | TIOCM_RTS;
|
|
rc = ioctl(fd, TIOCMBIS, &v24);
|
|
if (rc < 0) {
|
|
dbg_perror("ioctl(TIOCMBIS)");
|
|
/* some serial porst don't support this, so let's not
|
|
* return an error here */
|
|
}
|
|
|
|
return fd;
|
|
|
|
error:
|
|
if (fd >= 0)
|
|
close(fd);
|
|
return rc;
|
|
}
|
|
|
|
static int
|
|
_osmo_serial_set_baudrate(int fd, speed_t baudrate)
|
|
{
|
|
int rc;
|
|
struct termios tio;
|
|
|
|
rc = tcgetattr(fd, &tio);
|
|
if (rc < 0) {
|
|
dbg_perror("tcgetattr()");
|
|
return -errno;
|
|
}
|
|
|
|
if (cfsetispeed(&tio, baudrate) < 0)
|
|
dbg_perror("cfsetispeed()");
|
|
if (cfsetospeed(&tio, baudrate) < 0)
|
|
dbg_perror("cfsetospeed()");
|
|
|
|
rc = tcsetattr(fd, TCSANOW, &tio);
|
|
if (rc < 0) {
|
|
dbg_perror("tcsetattr()");
|
|
return -errno;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*! Change current baudrate
|
|
* \param[in] fd File descriptor of the open device
|
|
* \param[in] baudrate Baudrate constant (speed_t: B9600, B...)
|
|
* \returns 0 for success or negative errno.
|
|
*/
|
|
int
|
|
osmo_serial_set_baudrate(int fd, speed_t baudrate)
|
|
{
|
|
osmo_serial_clear_custom_baudrate(fd);
|
|
return _osmo_serial_set_baudrate(fd, baudrate);
|
|
}
|
|
|
|
/*! Change current baudrate to a custom one using OS specific method
|
|
* \param[in] fd File descriptor of the open device
|
|
* \param[in] baudrate Baudrate as integer
|
|
* \returns 0 for success or negative errno.
|
|
*
|
|
* This function might not work on all OS or with all type of serial adapters
|
|
*/
|
|
int
|
|
osmo_serial_set_custom_baudrate(int fd, int baudrate)
|
|
{
|
|
#ifdef __linux__
|
|
int rc;
|
|
struct serial_struct ser_info;
|
|
|
|
rc = ioctl(fd, TIOCGSERIAL, &ser_info);
|
|
if (rc < 0) {
|
|
dbg_perror("ioctl(TIOCGSERIAL)");
|
|
return -errno;
|
|
}
|
|
|
|
ser_info.flags = ASYNC_SPD_CUST | ASYNC_LOW_LATENCY;
|
|
ser_info.custom_divisor = ser_info.baud_base / baudrate;
|
|
|
|
rc = ioctl(fd, TIOCSSERIAL, &ser_info);
|
|
if (rc < 0) {
|
|
dbg_perror("ioctl(TIOCSSERIAL)");
|
|
return -errno;
|
|
}
|
|
|
|
return _osmo_serial_set_baudrate(fd, B38400); /* 38400 is a kind of magic ... */
|
|
#elif defined(__APPLE__)
|
|
#ifndef IOSSIOSPEED
|
|
#define IOSSIOSPEED _IOW('T', 2, speed_t)
|
|
#endif
|
|
int rc;
|
|
|
|
unsigned int speed = baudrate;
|
|
rc = ioctl(fd, IOSSIOSPEED, &speed);
|
|
if (rc < 0) {
|
|
dbg_perror("ioctl(IOSSIOSPEED)");
|
|
return -errno;
|
|
}
|
|
return 0;
|
|
#else
|
|
#pragma message ("osmo_serial_set_custom_baudrate: unsupported platform")
|
|
return 0;
|
|
#endif
|
|
}
|
|
|
|
/*! Clear any custom baudrate
|
|
* \param[in] fd File descriptor of the open device
|
|
* \returns 0 for success or negative errno.
|
|
*
|
|
* This function might not work on all OS or with all type of serial adapters
|
|
*/
|
|
int
|
|
osmo_serial_clear_custom_baudrate(int fd)
|
|
{
|
|
#ifdef __linux__
|
|
int rc;
|
|
struct serial_struct ser_info;
|
|
|
|
rc = ioctl(fd, TIOCGSERIAL, &ser_info);
|
|
if (rc < 0) {
|
|
dbg_perror("ioctl(TIOCGSERIAL)");
|
|
return -errno;
|
|
}
|
|
|
|
ser_info.flags = ASYNC_LOW_LATENCY;
|
|
ser_info.custom_divisor = 0;
|
|
|
|
rc = ioctl(fd, TIOCSSERIAL, &ser_info);
|
|
if (rc < 0) {
|
|
dbg_perror("ioctl(TIOCSSERIAL)");
|
|
return -errno;
|
|
}
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/*! Convert unsigned integer value to speed_t
|
|
* \param[in] baudrate integer value containing the desired standard baudrate
|
|
* \param[out] speed the standrd baudrate requested in speed_t format
|
|
* \returns 0 for success or negative errno.
|
|
*/
|
|
int
|
|
osmo_serial_speed_t(unsigned int baudrate, speed_t *speed)
|
|
{
|
|
switch(baudrate) {
|
|
case 0: *speed = B0; break;
|
|
case 50: *speed = B50; break;
|
|
case 75: *speed = B75; break;
|
|
case 110: *speed = B110; break;
|
|
case 134: *speed = B134; break;
|
|
case 150: *speed = B150; break;
|
|
case 200: *speed = B200; break;
|
|
case 300: *speed = B300; break;
|
|
case 600: *speed = B600; break;
|
|
case 1200: *speed = B1200; break;
|
|
case 1800: *speed = B1800; break;
|
|
case 2400: *speed = B2400; break;
|
|
case 4800: *speed = B4800; break;
|
|
case 9600: *speed = B9600; break;
|
|
case 19200: *speed = B19200; break;
|
|
case 38400: *speed = B38400; break;
|
|
case 57600: *speed = B57600; break;
|
|
case 115200: *speed = B115200; break;
|
|
case 230400: *speed = B230400; break;
|
|
default:
|
|
*speed = B0;
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*! @} */
|