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mirror of git://sigrok.org/libserialport synced 2023-08-10 21:13:24 +03:00
libserialport/serialport.c
2013-11-15 00:42:37 +01:00

780 lines
17 KiB
C

/*
* This file is part of the libserialport project.
*
* Copyright (C) 2010-2012 Bert Vermeulen <bert@biot.com>
* Copyright (C) 2010-2012 Uwe Hermann <uwe@hermann-uwe.de>
* Copyright (C) 2013 Martin Ling <martin-libserialport@earth.li>
*
* 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/>.
*/
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#ifdef _WIN32
#include <windows.h>
#include <tchar.h>
#else
#include <termios.h>
#include <sys/ioctl.h>
#endif
#ifdef __APPLE__
#include <IOKit/IOKitLib.h>
#include <IOKit/serial/IOSerialKeys.h>
#include <sys/syslimits.h>
#endif
#ifdef __linux__
#include "libudev.h"
#include "linux/serial.h"
#endif
#include "serialport.h"
static char **sp_list_new(void)
{
char **list;
if ((list = malloc(sizeof(char *))))
list[0] = NULL;
return list;
}
static char **sp_list_append(char **list, void *data, size_t len)
{
void *tmp;
unsigned int count;
for (count = 0; list[count]; count++);
if (!(tmp = realloc(list, sizeof(char *) * (count + 2))))
goto fail;
list = tmp;
if (!(list[count] = malloc(len)))
goto fail;
memcpy(list[count], data, len);
list[count + 1] = NULL;
return list;
fail:
sp_free_port_list(list);
return NULL;
}
/**
* List the serial ports available on the system.
*
* @return A null-terminated array of port name strings.
*/
char **sp_list_ports(void)
{
char **list = NULL;
#ifdef _WIN32
HKEY key;
TCHAR *value, *data;
DWORD max_value_len, max_data_size, max_data_len;
DWORD value_len, data_size, data_len;
DWORD type, index = 0;
if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, _T("HARDWARE\\DEVICEMAP\\SERIALCOMM"),
0, KEY_QUERY_VALUE, &key) != ERROR_SUCCESS)
return NULL;
if (RegQueryInfoKey(key, NULL, NULL, NULL, NULL, NULL, NULL, NULL,
&max_value_len, &max_data_size, NULL, NULL) != ERROR_SUCCESS)
goto out_close;
max_data_len = max_data_size / sizeof(TCHAR);
if (!(value = malloc((max_value_len + 1) * sizeof(TCHAR))))
goto out_close;
if (!(data = malloc((max_data_len + 1) * sizeof(TCHAR))))
goto out_free_value;
if (!(list = sp_list_new()))
goto out;
while (
value_len = max_value_len,
data_size = max_data_size,
RegEnumValue(key, index, value, &value_len,
NULL, &type, (LPBYTE)data, &data_size) == ERROR_SUCCESS)
{
data_len = data_size / sizeof(TCHAR);
data[data_len] = '\0';
if (type == REG_SZ)
if (!(list = sp_list_append(list,
data, (data_len + 1) * sizeof(TCHAR))))
goto out;
index++;
}
out:
free(data);
out_free_value:
free(value);
out_close:
RegCloseKey(key);
return list;
#endif
#ifdef __APPLE__
mach_port_t master;
CFMutableDictionaryRef classes;
io_iterator_t iter;
char *path;
io_object_t port;
CFTypeRef cf_path;
Boolean result;
if (IOMasterPort(MACH_PORT_NULL, &master) != KERN_SUCCESS)
return NULL;
if (!(classes = IOServiceMatching(kIOSerialBSDServiceValue)))
return NULL;
CFDictionarySetValue(classes,
CFSTR(kIOSerialBSDTypeKey), CFSTR(kIOSerialBSDAllTypes));
if (!(IOServiceGetMatchingServices(master, classes, &iter)))
return NULL;
if (!(path = malloc(PATH_MAX)))
goto out_release;
if (!(list = sp_list_new()))
goto out;
while ((port = IOIteratorNext(iter))) {
cf_path = IORegistryEntryCreateCFProperty(port,
CFSTR(kIOCalloutDeviceKey), kCFAllocatorDefault, 0);
if (cf_path) {
result = CFStringGetCString(cf_path,
path, PATH_MAX, kCFStringEncodingASCII);
CFRelease(cf_path);
if (result)
if (!(list = sp_list_append(list, path, strlen(path) + 1)))
{
IOObjectRelease(port);
goto out;
}
}
IOObjectRelease(port);
}
out:
free(path);
out_release:
IOObjectRelease(iter);
return list;
#endif
#ifdef __linux__
struct udev *ud;
struct udev_enumerate *ud_enumerate;
struct udev_list_entry *ud_list;
struct udev_list_entry *ud_entry;
const char *path;
struct udev_device *ud_dev, *ud_parent;
const char *name;
const char *driver;
int fd, ioctl_result;
struct serial_struct serial_info;
ud = udev_new();
ud_enumerate = udev_enumerate_new(ud);
udev_enumerate_add_match_subsystem(ud_enumerate, "tty");
udev_enumerate_scan_devices(ud_enumerate);
ud_list = udev_enumerate_get_list_entry(ud_enumerate);
if (!(list = sp_list_new()))
goto out;
udev_list_entry_foreach(ud_entry, ud_list)
{
path = udev_list_entry_get_name(ud_entry);
ud_dev = udev_device_new_from_syspath(ud, path);
/* If there is no parent device, this is a virtual tty. */
ud_parent = udev_device_get_parent(ud_dev);
if (ud_parent == NULL)
{
udev_device_unref(ud_dev);
continue;
}
name = udev_device_get_devnode(ud_dev);
/* The serial8250 driver has a hardcoded number of ports.
* The only way to tell which actually exist on a given system
* is to try to open them and make an ioctl call. */
driver = udev_device_get_driver(ud_parent);
if (driver && !strcmp(driver, "serial8250"))
{
if ((fd = open(name, O_RDWR | O_NONBLOCK | O_NOCTTY)) < 0)
goto skip;
ioctl_result = ioctl(fd, TIOCGSERIAL, &serial_info);
close(fd);
if (ioctl_result != 0)
goto skip;
if (serial_info.type == PORT_UNKNOWN)
goto skip;
}
list = sp_list_append(list, (void *)name, strlen(name) + 1);
skip:
udev_device_unref(ud_dev);
if (!list)
goto out;
}
out:
udev_enumerate_unref(ud_enumerate);
udev_unref(ud);
return list;
#endif
}
/**
* Free a port list returned by sp_list_ports.
*/
void sp_free_port_list(char **list)
{
unsigned int i;
for (i = 0; list[i]; i++)
free(list[i]);
free(list);
}
static int sp_validate_port(struct sp_port *port)
{
if (port == NULL)
return 0;
#ifdef _WIN32
if (port->hdl == INVALID_HANDLE_VALUE)
return 0;
#else
if (port->fd < 0)
return 0;
#endif
return 1;
}
#define CHECK_PORT() do { if (!sp_validate_port(port)) return SP_ERR_ARG; } while (0)
/**
* Open the specified serial port.
*
* @param port Pointer to empty port structure allocated by caller.
* @param portname Name of port to open.
* @param flags Flags to use when opening the serial port. Possible flags
* are: SP_MODE_RDWR, SP_MODE_RDONLY, SP_MODE_NONBLOCK.
*
* @return SP_OK on success, SP_ERR_FAIL on failure,
* or SP_ERR_ARG if an invalid port or name is passed.
*/
int sp_open(struct sp_port *port, char *portname, int flags)
{
if (!port)
return SP_ERR_ARG;
if (!portname)
return SP_ERR_ARG;
port->name = portname;
#ifdef _WIN32
DWORD desired_access = 0, flags_and_attributes = 0;
/* Map 'flags' to the OS-specific settings. */
desired_access |= GENERIC_READ;
flags_and_attributes = FILE_ATTRIBUTE_NORMAL;
if (flags & SP_MODE_RDWR)
desired_access |= GENERIC_WRITE;
if (flags & SP_MODE_NONBLOCK)
flags_and_attributes |= FILE_FLAG_OVERLAPPED;
port->hdl = CreateFile(port->name, desired_access, 0, 0,
OPEN_EXISTING, flags_and_attributes, 0);
if (port->hdl == INVALID_HANDLE_VALUE)
return SP_ERR_FAIL;
#else
int flags_local = 0;
/* Map 'flags' to the OS-specific settings. */
if (flags & SP_MODE_RDWR)
flags_local |= O_RDWR;
if (flags & SP_MODE_RDONLY)
flags_local |= O_RDONLY;
if (flags & SP_MODE_NONBLOCK)
flags_local |= O_NONBLOCK;
if ((port->fd = open(port->name, flags_local)) < 0)
return SP_ERR_FAIL;
#endif
return SP_OK;
}
/**
* Close the specified serial port.
*
* @param port Pointer to port structure.
*
* @return SP_OK on success, SP_ERR_FAIL on failure,
* or SP_ERR_ARG if an invalid port is passed.
*/
int sp_close(struct sp_port *port)
{
CHECK_PORT();
#ifdef _WIN32
/* Returns non-zero upon success, 0 upon failure. */
if (CloseHandle(port->hdl) == 0)
return SP_ERR_FAIL;
#else
/* Returns 0 upon success, -1 upon failure. */
if (close(port->fd) == -1)
return SP_ERR_FAIL;
#endif
return SP_OK;
}
/**
* Flush serial port buffers.
*
* @param port Pointer to port structure.
*
* @return SP_OK on success, SP_ERR_FAIL on failure,
* or SP_ERR_ARG if an invalid port is passed.
*/
int sp_flush(struct sp_port *port)
{
CHECK_PORT();
#ifdef _WIN32
/* Returns non-zero upon success, 0 upon failure. */
if (PurgeComm(port->hdl, PURGE_RXCLEAR | PURGE_TXCLEAR) == 0)
return SP_ERR_FAIL;
#else
/* Returns 0 upon success, -1 upon failure. */
if (tcflush(port->fd, TCIOFLUSH) < 0)
return SP_ERR_FAIL;
#endif
return SP_OK;
}
/**
* Write a number of bytes to the specified serial port.
*
* @param port Pointer to port structure.
* @param buf Buffer containing the bytes to write.
* @param count Number of bytes to write.
*
* @return The number of bytes written, SP_ERR_FAIL on failure,
* or SP_ERR_ARG if an invalid port is passed.
*/
int sp_write(struct sp_port *port, const void *buf, size_t count)
{
CHECK_PORT();
if (!buf)
return SP_ERR_ARG;
#ifdef _WIN32
DWORD written = 0;
/* Returns non-zero upon success, 0 upon failure. */
if (WriteFile(port->hdl, buf, count, &written, NULL) == 0)
return SP_ERR_FAIL;
return written;
#else
/* Returns the number of bytes written, or -1 upon failure. */
ssize_t written = write(port->fd, buf, count);
if (written < 0)
return SP_ERR_FAIL;
else
return written;;
#endif
}
/**
* Read a number of bytes from the specified serial port.
*
* @param port Pointer to port structure.
* @param buf Buffer where to store the bytes that are read.
* @param count The number of bytes to read.
*
* @return The number of bytes read, SP_ERR_FAIL on failure,
* or SP_ERR_ARG if an invalid port is passed.
*/
int sp_read(struct sp_port *port, void *buf, size_t count)
{
CHECK_PORT();
if (!buf)
return SP_ERR_ARG;
#ifdef _WIN32
DWORD bytes_read = 0;
/* Returns non-zero upon success, 0 upon failure. */
if (ReadFile(port->hdl, buf, count, &bytes_read, NULL) == 0)
return SP_ERR_FAIL;
return bytes_read;
#else
ssize_t bytes_read;
/* Returns the number of bytes read, or -1 upon failure. */
if ((bytes_read = read(port->fd, buf, count)) < 0)
return SP_ERR_FAIL;
return bytes_read;
#endif
}
/**
* Set serial parameters for the specified serial port.
*
* @param port Pointer to port structure.
* @param baudrate The baudrate to set.
* @param bits The number of data bits to use.
* @param parity The parity setting to use (0 = none, 1 = even, 2 = odd).
* @param stopbits The number of stop bits to use (1 or 2).
* @param flowcontrol The flow control settings to use (0 = none, 1 = RTS/CTS,
* 2 = XON/XOFF).
*
* @return The number of bytes read, SP_ERR_FAIL on failure,
* or SP_ERR_ARG if an invalid argument is passed.
*/
int sp_set_params(struct sp_port *port, int baudrate,
int bits, int parity, int stopbits,
int flowcontrol, int rts, int dtr)
{
CHECK_PORT();
#ifdef _WIN32
DCB dcb;
if (!GetCommState(port->hdl, &dcb))
return SP_ERR_FAIL;
switch (baudrate) {
/*
* The baudrates 50/75/134/150/200/1800/230400/460800 do not seem to
* have documented CBR_* macros.
*/
case 110:
dcb.BaudRate = CBR_110;
break;
case 300:
dcb.BaudRate = CBR_300;
break;
case 600:
dcb.BaudRate = CBR_600;
break;
case 1200:
dcb.BaudRate = CBR_1200;
break;
case 2400:
dcb.BaudRate = CBR_2400;
break;
case 4800:
dcb.BaudRate = CBR_4800;
break;
case 9600:
dcb.BaudRate = CBR_9600;
break;
case 14400:
dcb.BaudRate = CBR_14400; /* Not available on Unix? */
break;
case 19200:
dcb.BaudRate = CBR_19200;
break;
case 38400:
dcb.BaudRate = CBR_38400;
break;
case 57600:
dcb.BaudRate = CBR_57600;
break;
case 115200:
dcb.BaudRate = CBR_115200;
break;
case 128000:
dcb.BaudRate = CBR_128000; /* Not available on Unix? */
break;
case 256000:
dcb.BaudRate = CBR_256000; /* Not available on Unix? */
break;
default:
return SP_ERR_ARG;
}
switch (stopbits) {
/* Note: There's also ONE5STOPBITS == 1.5 (unneeded so far). */
case 1:
dcb.StopBits = ONESTOPBIT;
break;
case 2:
dcb.StopBits = TWOSTOPBITS;
break;
default:
return SP_ERR_ARG;
}
switch (parity) {
/* Note: There's also SPACEPARITY, MARKPARITY (unneeded so far). */
case SP_PARITY_NONE:
dcb.Parity = NOPARITY;
break;
case SP_PARITY_EVEN:
dcb.Parity = EVENPARITY;
break;
case SP_PARITY_ODD:
dcb.Parity = ODDPARITY;
break;
default:
return SP_ERR_ARG;
}
if (rts != -1) {
if (rts)
dcb.fRtsControl = RTS_CONTROL_ENABLE;
else
dcb.fRtsControl = RTS_CONTROL_DISABLE;
}
if (dtr != -1) {
if (dtr)
dcb.fDtrControl = DTR_CONTROL_ENABLE;
else
dcb.fDtrControl = DTR_CONTROL_DISABLE;
}
if (!SetCommState(port->hdl, &dcb))
return SP_ERR_FAIL;
#else
struct termios term;
speed_t baud;
int controlbits;
if (tcgetattr(port->fd, &term) < 0)
return SP_ERR_FAIL;
switch (baudrate) {
case 50:
baud = B50;
break;
case 75:
baud = B75;
break;
case 110:
baud = B110;
break;
case 134:
baud = B134;
break;
case 150:
baud = B150;
break;
case 200:
baud = B200;
break;
case 300:
baud = B300;
break;
case 600:
baud = B600;
break;
case 1200:
baud = B1200;
break;
case 1800:
baud = B1800;
break;
case 2400:
baud = B2400;
break;
case 4800:
baud = B4800;
break;
case 9600:
baud = B9600;
break;
case 19200:
baud = B19200;
break;
case 38400:
baud = B38400;
break;
case 57600:
baud = B57600;
break;
case 115200:
baud = B115200;
break;
case 230400:
baud = B230400;
break;
#if !defined(__APPLE__) && !defined(__OpenBSD__)
case 460800:
baud = B460800;
break;
#endif
default:
return SP_ERR_ARG;
}
if (cfsetospeed(&term, baud) < 0)
return SP_ERR_FAIL;
if (cfsetispeed(&term, baud) < 0)
return SP_ERR_FAIL;
term.c_cflag &= ~CSIZE;
switch (bits) {
case 8:
term.c_cflag |= CS8;
break;
case 7:
term.c_cflag |= CS7;
break;
default:
return SP_ERR_ARG;
}
term.c_cflag &= ~CSTOPB;
switch (stopbits) {
case 1:
term.c_cflag &= ~CSTOPB;
break;
case 2:
term.c_cflag |= CSTOPB;
break;
default:
return SP_ERR_ARG;
}
term.c_iflag &= ~(IXON | IXOFF | IXANY);
term.c_cflag &= ~CRTSCTS;
switch (flowcontrol) {
case 0:
/* No flow control. */
break;
case 1:
term.c_cflag |= CRTSCTS;
break;
case 2:
term.c_iflag |= IXON | IXOFF | IXANY;
break;
default:
return SP_ERR_ARG;
}
term.c_iflag &= ~IGNPAR;
term.c_cflag &= ~(PARENB | PARODD);
switch (parity) {
case SP_PARITY_NONE:
term.c_iflag |= IGNPAR;
break;
case SP_PARITY_EVEN:
term.c_cflag |= PARENB;
break;
case SP_PARITY_ODD:
term.c_cflag |= PARENB | PARODD;
break;
default:
return SP_ERR_ARG;
}
/* Turn off all serial port cooking. */
term.c_iflag &= ~(ISTRIP | INLCR | ICRNL);
term.c_oflag &= ~(ONLCR | OCRNL | ONOCR);
#if !defined(__FreeBSD__) && !defined(__OpenBSD__) && !defined(__NetBSD__)
term.c_oflag &= ~OFILL;
#endif
/* Disable canonical mode, and don't echo input characters. */
term.c_lflag &= ~(ICANON | ECHO);
/* Ignore modem status lines; enable receiver */
term.c_cflag |= (CLOCAL | CREAD);
/* Write the configured settings. */
if (tcsetattr(port->fd, TCSADRAIN, &term) < 0)
return SP_ERR_FAIL;
if (rts != -1) {
controlbits = TIOCM_RTS;
if (ioctl(port->fd, rts ? TIOCMBIS : TIOCMBIC,
&controlbits) < 0)
return SP_ERR_FAIL;
}
if (dtr != -1) {
controlbits = TIOCM_DTR;
if (ioctl(port->fd, dtr ? TIOCMBIS : TIOCMBIC,
&controlbits) < 0)
return SP_ERR_FAIL;
}
#endif
return SP_OK;
}
/**
* Get error code for failed operation.
*
* In order to obtain the correct result, this function should be called
* straight after the failure, before executing any other system operations.
*
* @return The system's numeric code for the error that caused the last
* operation to fail.
*/
int sp_last_error_code(void)
{
#ifdef _WIN32
return GetLastError();
#else
return errno;
#endif
}
/**
* Get error message for failed operation.
*
* In order to obtain the correct result, this function should be called
* straight after the failure, before executing other system operations.
*
* @return The system's message for the error that caused the last
* operation to fail. This string may be allocated by the function,
* and can be freed after use by calling sp_free_error_message.
*/
char *sp_last_error_message(void)
{
#ifdef _WIN32
LPVOID message;
DWORD error = GetLastError();
FormatMessage(
FORMAT_MESSAGE_ALLOCATE_BUFFER |
FORMAT_MESSAGE_FROM_SYSTEM |
FORMAT_MESSAGE_IGNORE_INSERTS,
NULL,
error,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
(LPTSTR) &message,
0, NULL );
return message;
#else
return strerror(errno);
#endif
}
/**
* Free error message.
*
* This function can be used to free a string returned by the
* sp_last_error_message function.
*/
void sp_free_error_message(char *message)
{
#ifdef _WIN32
LocalFree(message);
#else
(void)message;
#endif
}