Mirror
/
ardupilot
mirror of https://github.com/ArduPilot/ardupilot
5
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
ardupilot/libraries/AP_HAL_VRBRAIN/UARTDriver.cpp

485 lines
12 KiB
C++
Raw Blame History

#include <AP_HAL/AP_HAL.h>
#if CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN
#include "UARTDriver.h"
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <termios.h>
#include <drivers/drv_hrt.h>
#include <assert.h>
#include "GPIO.h"
using namespace VRBRAIN;
extern const AP_HAL::HAL& hal;
VRBRAINUARTDriver::VRBRAINUARTDriver(const char *devpath, const char *perf_name) :
_devpath(devpath),
_fd(-1),
_baudrate(57600),
_initialised(false),
_in_timer(false),
_perf_uart(perf_alloc(PC_ELAPSED, perf_name)),
_os_start_auto_space(-1),
_flow_control(FLOW_CONTROL_DISABLE)
{
}
extern const AP_HAL::HAL& hal;
/*
this UART driver maps to a serial device in /dev
*/
void VRBRAINUARTDriver::begin(uint32_t b, uint16_t rxS, uint16_t txS)
{
if (strcmp(_devpath, "/dev/null") == 0) {
// leave uninitialised
return;
}
uint16_t min_tx_buffer = 1024;
uint16_t min_rx_buffer = 512;
if (strcmp(_devpath, "/dev/ttyACM0") == 0) {
min_tx_buffer = 4096;
min_rx_buffer = 1024;
}
// on VRBRAIN we have enough memory to have a larger transmit and
// receive buffer for all ports. This means we don't get delays
// while waiting to write GPS config packets
if (txS < min_tx_buffer) {
txS = min_tx_buffer;
}
if (rxS < min_rx_buffer) {
rxS = min_rx_buffer;
}
/*
allocate the read buffer
we allocate buffers before we successfully open the device as we
want to allocate in the early stages of boot, and cause minimum
thrashing of the heap once we are up. The ttyACM0 driver may not
connect for some time after boot
*/
if (rxS != 0 && rxS != _readbuf.get_size()) {
_initialised = false;
while (_in_timer) {
hal.scheduler->delay(1);
}
_readbuf.set_size(rxS);
}
if (b != 0) {
_baudrate = b;
}
/*
allocate the write buffer
*/
if (txS != 0 && txS != _writebuf.get_size()) {
_initialised = false;
while (_in_timer) {
hal.scheduler->delay(1);
}
_writebuf.set_size(txS);
}
if (_fd == -1) {
_fd = open(_devpath, O_RDWR);
if (_fd == -1) {
return;
}
}
if (_baudrate != 0) {
// set the baud rate
struct termios t;
tcgetattr(_fd, &t);
cfsetspeed(&t, _baudrate);
// disable LF -> CR/LF
t.c_oflag &= ~ONLCR;
tcsetattr(_fd, TCSANOW, &t);
// separately setup IFLOW if we can. We do this as a 2nd call
// as if the port has no RTS pin then the tcsetattr() call
// will fail, and if done as one call then it would fail to
// set the baudrate.
tcgetattr(_fd, &t);
t.c_cflag |= CRTS_IFLOW;
tcsetattr(_fd, TCSANOW, &t);
}
if (_writebuf.get_size() && _readbuf.get_size() && _fd != -1) {
if (!_initialised) {
if (strcmp(_devpath, "/dev/ttyACM0") == 0) {
((VRBRAINGPIO *)hal.gpio)->set_usb_connected();
}
::printf("initialised %s OK %u %u\n", _devpath,
(unsigned)_writebuf.get_size(), (unsigned)_readbuf.get_size());
}
_initialised = true;
}
_uart_owner_pid = getpid();
}
void VRBRAINUARTDriver::set_flow_control(enum flow_control fcontrol)
{
if (_fd == -1) {
return;
}
struct termios t;
tcgetattr(_fd, &t);
// we already enabled CRTS_IFLOW above, just enable output flow control
if (fcontrol != FLOW_CONTROL_DISABLE) {
t.c_cflag |= CRTSCTS;
} else {
t.c_cflag &= ~CRTSCTS;
}
tcsetattr(_fd, TCSANOW, &t);
if (fcontrol == FLOW_CONTROL_AUTO) {
// reset flow control auto state machine
_total_written = 0;
_first_write_time = 0;
}
_flow_control = fcontrol;
}
void VRBRAINUARTDriver::begin(uint32_t b)
{
begin(b, 0, 0);
}
/*
try to initialise the UART. This is used to cope with the way NuttX
handles /dev/ttyACM0 (the USB port). The port appears in /dev on
boot, but cannot be opened until a USB cable is connected and the
host starts the CDCACM communication.
*/
void VRBRAINUARTDriver::try_initialise(void)
{
if (_initialised) {
return;
}
if ((AP_HAL::millis() - _last_initialise_attempt_ms) < 2000) {
return;
}
_last_initialise_attempt_ms = AP_HAL::millis();
if (hal.util->safety_switch_state() != AP_HAL::Util::SAFETY_ARMED || !hal.util->get_soft_armed()) {
begin(0);
}
}
void VRBRAINUARTDriver::end()
{
_initialised = false;
while (_in_timer) hal.scheduler->delay(1);
if (_fd != -1) {
close(_fd);
_fd = -1;
}
_readbuf.set_size(0);
_writebuf.set_size(0);
}
void VRBRAINUARTDriver::flush() {}
bool VRBRAINUARTDriver::is_initialized()
{
try_initialise();
return _initialised;
}
void VRBRAINUARTDriver::set_blocking_writes(bool blocking)
{
_nonblocking_writes = !blocking;
}
bool VRBRAINUARTDriver::tx_pending() { return false; }
/*
return number of bytes available to be read from the buffer
*/
uint32_t VRBRAINUARTDriver::available()
{
if (!_initialised) {
try_initialise();
return 0;
}
return _readbuf.available();
}
/*
return number of bytes that can be added to the write buffer
*/
uint32_t VRBRAINUARTDriver::txspace()
{
if (!_initialised) {
try_initialise();
return 0;
}
return _writebuf.space();
}
/*
read one byte from the read buffer
*/
int16_t VRBRAINUARTDriver::read()
{
if (_uart_owner_pid != getpid()){
return -1;
}
if (!_initialised) {
try_initialise();
return -1;
}
uint8_t byte;
if (!_readbuf.read_byte(&byte))
return -1;
return byte;
}
/*
write one byte to the buffer
*/
size_t VRBRAINUARTDriver::write(uint8_t c)
{
if (_uart_owner_pid != getpid()){
return 0;
}
if (!_initialised) {
try_initialise();
return 0;
}
while (_writebuf.space() == 0) {
if (_nonblocking_writes) {
return 0;
}
hal.scheduler->delay(1);
}
return _writebuf.write(&c, 1);
}
/*
write size bytes to the write buffer
*/
size_t VRBRAINUARTDriver::write(const uint8_t *buffer, size_t size)
{
if (_uart_owner_pid != getpid()){
return 0;
}
if (!_initialised) {
try_initialise();
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;
}
return _writebuf.write(buffer, size);
}
/*
try writing n bytes, handling an unresponsive port
*/
int VRBRAINUARTDriver::_write_fd(const uint8_t *buf, uint16_t n)
{
int ret = 0;
// the FIONWRITE check is to cope with broken O_NONBLOCK behaviour
// in NuttX on ttyACM0
// FIONWRITE is also used for auto flow control detection
// Assume output flow control is not working if:
// port is configured for auto flow control
// and this is not the first write since flow control turned on
// and no data has been removed from the buffer since flow control turned on
// and more than .5 seconds elapsed after writing a total of > 5 characters
//
int nwrite = 0;
if (ioctl(_fd, FIONWRITE, (unsigned long)&nwrite) == 0) {
if (_flow_control == FLOW_CONTROL_AUTO) {
if (_first_write_time == 0) {
if (_total_written == 0) {
// save the remaining buffer bytes for comparison next write
_os_start_auto_space = nwrite;
}
} else {
if (_os_start_auto_space - nwrite + 1 >= _total_written &&
(AP_HAL::micros64() - _first_write_time) > 500*1000UL) {
// it doesn't look like hw flow control is working
::printf("disabling flow control on %s _total_written=%u\n",
_devpath, (unsigned)_total_written);
set_flow_control(FLOW_CONTROL_DISABLE);
}
}
}
if (nwrite > n) {
nwrite = n;
}
if (nwrite > 0) {
ret = ::write(_fd, buf, nwrite);
}
}
if (ret > 0) {
_last_write_time = AP_HAL::micros64();
_total_written += ret;
if (! _first_write_time && _total_written > 5) {
_first_write_time = _last_write_time;
}
return ret;
}
if (AP_HAL::micros64() - _last_write_time > 2000 &&
_flow_control == FLOW_CONTROL_DISABLE) {
#if 0
// this trick is disabled for now, as it sometimes blocks on
// re-opening the ttyACM0 port, which would cause a crash
if (AP_HAL::micros64() - _last_write_time > 2000000) {
// we haven't done a successful write for 2 seconds - try
// reopening the port
_initialised = false;
::close(_fd);
_fd = ::open(_devpath, O_RDWR);
if (_fd == -1) {
fprintf(stdout, "Failed to reopen UART device %s - %s\n",
_devpath, strerror(errno));
// leave it uninitialised
return n;
}
_last_write_time = AP_HAL::micros64();
_initialised = true;
}
#else
_last_write_time = AP_HAL::micros64();
#endif
// we haven't done a successful write for 2ms, which means the
// port is running at less than 500 bytes/sec. Start
// discarding bytes, even if this is a blocking port. This
// prevents the ttyACM0 port blocking startup if the endpoint
// is not connected
return n;
}
return ret;
}
/*
try reading n bytes, handling an unresponsive port
*/
int VRBRAINUARTDriver::_read_fd(uint8_t *buf, uint16_t n)
{
int ret = 0;
// the FIONREAD check is to cope with broken O_NONBLOCK behaviour
// in NuttX on ttyACM0
int nread = 0;
if (ioctl(_fd, FIONREAD, (unsigned long)&nread) == 0) {
if (nread > n) {
nread = n;
}
if (nread > 0) {
ret = ::read(_fd, buf, nread);
}
}
if (ret > 0) {
_total_read += ret;
}
return ret;
}
/*
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 VRBRAINUARTDriver::_timer_tick(void)
{
int ret;
uint32_t n;
if (!_initialised) return;
// don't try IO on a disconnected USB port
if (strcmp(_devpath, "/dev/ttyACM0") == 0 && !hal.gpio->usb_connected()) {
return;
}
_in_timer = true;
// write any pending bytes
n = _writebuf.available();
if (n > 0) {
ByteBuffer::IoVec vec[2];
perf_begin(_perf_uart);
const auto n_vec = _writebuf.peekiovec(vec, n);
for (int i = 0; i < n_vec; i++) {
ret = _write_fd(vec[i].data, (uint16_t)vec[i].len);
if (ret < 0) {
break;
}
_writebuf.advance(ret);
/* We wrote less than we asked for, stop */
if ((unsigned)ret != vec[i].len) {
break;
}
}
perf_end(_perf_uart);
}
// try to fill the read buffer
ByteBuffer::IoVec vec[2];
perf_begin(_perf_uart);
const auto n_vec = _readbuf.reserve(vec, _readbuf.space());
for (int i = 0; i < n_vec; i++) {
ret = _read_fd(vec[i].data, vec[i].len);
if (ret < 0) {
break;
}
_readbuf.commit((unsigned)ret);
/* stop reading as we read less than we asked for */
if ((unsigned)ret < vec[i].len) {
break;
}
}
perf_end(_perf_uart);
_in_timer = false;
}
#endif // CONFIG_HAL_BOARD
Reference in New Issue View Git Blame Copy Permalink