ardupilot/libraries/AP_HAL_Linux/UARTDriver.cpp

608 lines
13 KiB
C++

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: -*- nil -*-
#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_LINUX
#include "UARTDriver.h"
#include <stdio.h>
#include <errno.h>
#include <termios.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <poll.h>
#include <assert.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <string.h>
#include <arpa/inet.h>
#include <AP_HAL/utility/RingBuffer.h>
#include "UARTDevice.h"
#include "UDPDevice.h"
#include "ConsoleDevice.h"
#include "TCPServerDevice.h"
extern const AP_HAL::HAL& hal;
using namespace Linux;
UARTDriver::UARTDriver(bool default_console) :
device_path(NULL),
_packetise(false),
_flow_control(FLOW_CONTROL_DISABLE)
{
if (default_console) {
_device = new ConsoleDevice();
_device->open();
_console = true;
}
}
/*
set the tty device to use for this UART
*/
void UARTDriver::set_device_path(const char *path)
{
device_path = path;
}
/*
open the tty
*/
void UARTDriver::begin(uint32_t b)
{
begin(b, 0, 0);
}
void UARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
{
if (device_path == NULL && _console) {
_device = new ConsoleDevice();
_device->open();
_device->set_blocking(false);
} else if (!_initialised) {
if (device_path == NULL) {
return;
}
switch (_parseDevicePath(device_path)) {
case DEVICE_TCP:
{
_tcp_start_connection();
_flow_control = FLOW_CONTROL_ENABLE;
break;
}
case DEVICE_UDP:
{
_udp_start_connection();
_flow_control = FLOW_CONTROL_ENABLE;
break;
}
case DEVICE_SERIAL:
{
if (!_serial_start_connection()) {
break; /* Whatever it might mean */
}
break;
}
default:
{
// Notify that the option is not valid and select standart input and output
::printf("Argument is not valid. Fallback to console.\n");
::printf("Launch with --help to see an example.\n");
_device = new ConsoleDevice();
_device->open();
_device->set_blocking(false);
break;
}
}
}
_initialised = false;
while (_in_timer) hal.scheduler->delay(1);
_device->set_speed(b);
_allocate_buffers(rxS, txS);
}
void UARTDriver::_allocate_buffers(uint16_t rxS, uint16_t txS)
{
/* we have enough memory to have a larger transmit buffer for
* all ports. This means we don't get delays while waiting to
* write GPS config packets
*/
if (rxS < 8192) {
rxS = 8192;
}
if (txS < 32000) {
txS = 32000;
}
/*
allocate the read buffer
*/
if (rxS != 0 && rxS != _readbuf_size) {
_readbuf_size = rxS;
if (_readbuf != NULL) {
free(_readbuf);
}
_readbuf = (uint8_t *)malloc(_readbuf_size);
_readbuf_head = 0;
_readbuf_tail = 0;
}
/*
allocate the write buffer
*/
if (txS != 0 && txS != _writebuf_size) {
_writebuf_size = txS;
if (_writebuf != NULL) {
free(_writebuf);
}
_writebuf = (uint8_t *)malloc(_writebuf_size);
_writebuf_head = 0;
_writebuf_tail = 0;
}
if (_writebuf_size != 0 && _readbuf_size != 0) {
_initialised = true;
}
}
void UARTDriver::_deallocate_buffers()
{
if (_readbuf) {
free(_readbuf);
_readbuf = NULL;
}
if (_writebuf) {
free(_writebuf);
_writebuf = NULL;
}
_readbuf_size = _writebuf_size = 0;
_writebuf_head = 0;
_writebuf_tail = 0;
_readbuf_head = 0;
_readbuf_tail = 0;
}
/*
Device path accepts the following syntaxes:
- /dev/ttyO1
- tcp:*:1243:wait
- udp:192.168.2.15:1243
*/
UARTDriver::device_type UARTDriver::_parseDevicePath(const char *arg)
{
struct stat st;
if (stat(arg, &st) == 0 && S_ISCHR(st.st_mode)) {
return DEVICE_SERIAL;
} else if (strncmp(arg, "tcp:", 4) != 0 &&
strncmp(arg, "udp:", 4) != 0) {
return DEVICE_UNKNOWN;
}
char *devstr = strdup(arg);
if (devstr == NULL) {
return DEVICE_UNKNOWN;
}
char *saveptr = NULL;
char *protocol, *ip, *port, *flag;
protocol = strtok_r(devstr, ":", &saveptr);
ip = strtok_r(NULL, ":", &saveptr);
port = strtok_r(NULL, ":", &saveptr);
flag = strtok_r(NULL, ":", &saveptr);
device_type type = DEVICE_UNKNOWN;
if (ip == NULL || port == NULL) {
fprintf(stderr, "IP or port is set incorrectly.\n");
type = DEVICE_UNKNOWN;
goto errout;
}
if (_ip) {
free(_ip);
_ip = NULL;
}
if (_flag) {
free(_flag);
_flag = NULL;
}
_base_port = (uint16_t) atoi(port);
_ip = strdup(ip);
/* Optional flag for TCP */
if (flag != NULL) {
_flag = strdup(flag);
}
if (strcmp(protocol, "udp") == 0) {
type = DEVICE_UDP;
} else {
type = DEVICE_TCP;
}
errout:
free(devstr);
return type;
}
bool UARTDriver::_serial_start_connection()
{
_device = new UARTDevice(device_path);
_connected = _device->open();
_device->set_blocking(false);
_flow_control = FLOW_CONTROL_DISABLE;
return true;
}
/*
start a UDP connection for the serial port
*/
void UARTDriver::_udp_start_connection(void)
{
bool bcast = (_flag && strcmp(_flag, "bcast") == 0);
_device = new UDPDevice(_ip, _base_port, bcast);
_connected = _device->open();
_device->set_blocking(false);
/* try to write on MAVLink packet boundaries if possible */
_packetise = true;
}
void UARTDriver::_tcp_start_connection(void)
{
bool wait = (_flag && strcmp(_flag, "wait") == 0);
_device = new TCPServerDevice(_ip, _base_port, wait);
_connected = _device->open();
}
/*
shutdown a UART
*/
void UARTDriver::end()
{
_initialised = false;
_connected = false;
while (_in_timer) {
hal.scheduler->delay(1);
}
_device->close();
_deallocate_buffers();
}
void UARTDriver::flush()
{
// we are not doing any buffering, so flush is a no-op
}
/*
return true if the UART is initialised
*/
bool UARTDriver::is_initialized()
{
return _initialised;
}
/*
enable or disable blocking writes
*/
void UARTDriver::set_blocking_writes(bool blocking)
{
_nonblocking_writes = !blocking;
}
/*
do we have any bytes pending transmission?
*/
bool UARTDriver::tx_pending()
{
return !BUF_EMPTY(_writebuf);
}
/*
return the number of bytes available to be read
*/
int16_t UARTDriver::available()
{
if (!_initialised) {
return 0;
}
uint16_t _tail;
return BUF_AVAILABLE(_readbuf);
}
/*
how many bytes are available in the output buffer?
*/
int16_t UARTDriver::txspace()
{
if (!_initialised) {
return 0;
}
uint16_t _head;
return BUF_SPACE(_writebuf);
}
int16_t UARTDriver::read()
{
uint8_t c;
if (!_initialised || _readbuf == NULL) {
return -1;
}
if (BUF_EMPTY(_readbuf)) {
return -1;
}
c = _readbuf[_readbuf_head];
BUF_ADVANCEHEAD(_readbuf, 1);
return c;
}
/* Linux implementations of Print virtual methods */
size_t UARTDriver::write(uint8_t c)
{
if (!_initialised) {
return 0;
}
uint16_t _head;
while (BUF_SPACE(_writebuf) == 0) {
if (_nonblocking_writes) {
return 0;
}
hal.scheduler->delay(1);
}
_writebuf[_writebuf_tail] = c;
BUF_ADVANCETAIL(_writebuf, 1);
return 1;
}
/*
write size bytes to the write buffer
*/
size_t UARTDriver::write(const uint8_t *buffer, size_t size)
{
if (!_initialised) {
return 0;
}
if (!_nonblocking_writes) {
/*
use the per-byte delay loop in write() above for blocking writes
*/
size_t ret = 0;
while (size--) {
if (write(*buffer++) != 1) break;
ret++;
}
return ret;
}
uint16_t _head, space;
space = BUF_SPACE(_writebuf);
if (space == 0) {
return 0;
}
if (size > space) {
size = space;
}
if (_writebuf_tail < _head) {
// perform as single memcpy
assert(_writebuf_tail+size <= _writebuf_size);
memcpy(&_writebuf[_writebuf_tail], buffer, size);
BUF_ADVANCETAIL(_writebuf, size);
return size;
}
// perform as two memcpy calls
uint16_t n = _writebuf_size - _writebuf_tail;
if (n > size) n = size;
assert(_writebuf_tail+n <= _writebuf_size);
memcpy(&_writebuf[_writebuf_tail], buffer, n);
BUF_ADVANCETAIL(_writebuf, n);
buffer += n;
n = size - n;
if (n > 0) {
assert(_writebuf_tail+n <= _writebuf_size);
memcpy(&_writebuf[_writebuf_tail], buffer, n);
BUF_ADVANCETAIL(_writebuf, n);
}
return size;
}
/*
try writing n bytes, handling an unresponsive port
*/
int UARTDriver::_write_fd(const uint8_t *buf, uint16_t n)
{
int ret = 0;
/*
allow for delayed connection. This allows ArduPilot to start
before a network interface is available.
*/
if (!_connected) {
_connected = _device->open();
}
if (!_connected) {
return 0;
}
ret = _device->write(buf, n);
if (ret > 0) {
BUF_ADVANCEHEAD(_writebuf, ret);
return ret;
}
return ret;
}
/*
try reading n bytes, handling an unresponsive port
*/
int UARTDriver::_read_fd(uint8_t *buf, uint16_t n)
{
int ret;
ret = _device->read(buf, n);
if (ret > 0) {
BUF_ADVANCETAIL(_readbuf, ret);
}
return ret;
}
/*
try to push out one lump of pending bytes
return true if progress is made
*/
bool UARTDriver::_write_pending_bytes(void)
{
uint16_t n;
// write any pending bytes
uint16_t _tail;
uint16_t available_bytes = BUF_AVAILABLE(_writebuf);
n = available_bytes;
if (_packetise && n > 0 && _writebuf[_writebuf_head] != 254) {
/*
we have a non-mavlink packet at the start of the
buffer. Look ahead for a MAVLink start byte, up to 256 bytes
ahead
*/
uint16_t limit = n>256?256:n;
uint16_t i;
for (i=0; i<limit; i++) {
if (_writebuf[(_writebuf_head + i) % _writebuf_size] == 254) {
n = i;
break;
}
}
// if we didn't find a MAVLink marker then limit the send size to 256
if (i == limit) {
n = limit;
}
}
if (_packetise && n > 0 && _writebuf[_writebuf_head] == 254) {
// this looks like a MAVLink packet - try to write on
// packet boundaries when possible
if (n < 8) {
n = 0;
} else {
// the length of the packet is the 2nd byte, and mavlink
// packets have a 6 byte header plus 2 byte checksum,
// giving len+8 bytes
uint16_t ofs = (_writebuf_head + 1) % _writebuf_size;
uint8_t len = _writebuf[ofs];
if (n < len+8) {
// we don't have a full packet yet
n = 0;
} else if (n > len+8) {
// send just 1 packet at a time (so MAVLink packets
// are aligned on UDP boundaries)
n = len+8;
}
}
}
if (n > 0) {
uint16_t n1 = _writebuf_size - _writebuf_head;
if (n1 >= n) {
// do as a single write
_write_fd(&_writebuf[_writebuf_head], n);
} else {
// split into two writes
if (_packetise) {
// keep as a single UDP packet
uint8_t tmpbuf[n];
memcpy(tmpbuf, &_writebuf[_writebuf_head], n1);
if (n > n1) {
memcpy(&tmpbuf[n1], &_writebuf[0], n-n1);
}
_write_fd(tmpbuf, n);
} else {
int ret = _write_fd(&_writebuf[_writebuf_head], n1);
if (ret == n1 && n > n1) {
_write_fd(&_writebuf[_writebuf_head], n - n1);
}
}
}
}
return BUF_AVAILABLE(_writebuf) != available_bytes;
}
/*
push any pending bytes to/from the serial port. This is called at
1kHz in the timer thread. Doing it this way reduces the system call
overhead in the main task enormously.
*/
void UARTDriver::_timer_tick(void)
{
uint16_t n;
if (!_initialised) return;
_in_timer = true;
uint8_t num_send = 10;
while (num_send != 0 && _write_pending_bytes()) {
num_send--;
}
// try to fill the read buffer
uint16_t _head;
n = BUF_SPACE(_readbuf);
if (n > 0) {
uint16_t n1 = _readbuf_size - _readbuf_tail;
if (n1 >= n) {
// one read will do
assert(_readbuf_tail+n <= _readbuf_size);
_read_fd(&_readbuf[_readbuf_tail], n);
} else {
assert(_readbuf_tail+n1 <= _readbuf_size);
int ret = _read_fd(&_readbuf[_readbuf_tail], n1);
if (ret == n1 && n > n1) {
assert(_readbuf_tail+(n-n1) <= _readbuf_size);
_read_fd(&_readbuf[_readbuf_tail], n - n1);
}
}
}
_in_timer = false;
}
#endif // CONFIG_HAL_BOARD