ardupilot/libraries/AP_HAL_SMACCM/UARTDriver.cpp

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/*
* UARTDriver.cpp --- AP_HAL_SMACCM UART driver.
*
* Copyright (C) 2012, Galois, Inc.
* All Rights Reserved.
*
* This software is released under the "BSD3" license. Read the file
* "LICENSE" for more information.
*/
#include "UARTDriver.h"
#include <stdio.h> // for vsnprintf
using namespace SMACCM;
// XXX the AVR driver enables itself in the constructor. This seems
// like a very bad idea, since it will run somewhere in the startup
// code before our clocks are all set up and such.
SMACCMUARTDriver::SMACCMUARTDriver(struct usart *dev)
: m_dev(dev), m_initialized(false), m_blocking(true)
{
}
void SMACCMUARTDriver::begin(uint32_t baud)
{
usart_init(m_dev, baud);
usart_enable(m_dev);
m_initialized = true;
}
// XXX buffer sizes ignored
void SMACCMUARTDriver::begin(uint32_t baud, uint16_t rxS, uint16_t txS)
{
begin(baud);
}
// XXX hwf4 doesn't support de-initializing a USART
void SMACCMUARTDriver::end()
{
}
// XXX hwf4 doesn't support flushing, could be tricky to get the
// synchronization right. Would we just force the TX/RX queues to
// empty?
void SMACCMUARTDriver::flush()
{
}
bool SMACCMUARTDriver::is_initialized()
{
return m_initialized;
}
void SMACCMUARTDriver::set_blocking_writes(bool blocking)
{
m_blocking = blocking;
}
bool SMACCMUARTDriver::tx_pending()
{
return usart_is_tx_pending(m_dev);
}
/* SMACCM implementations of BetterStream virtual methods */
void SMACCMUARTDriver::print_P(const prog_char_t *pstr)
{
while (*pstr)
write(*pstr++);
}
void SMACCMUARTDriver::println_P(const prog_char_t *pstr)
{
print_P(pstr);
println();
}
// XXX this will be changing, putting this on the stack hurts but
// allows us to be easily re-entrant
void SMACCMUARTDriver::printf(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vprintf(fmt, ap);
va_end(ap);
}
void SMACCMUARTDriver::_printf_P(const prog_char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vprintf(fmt, ap);
va_end(ap);
}
void SMACCMUARTDriver::vprintf(const char *pstr, va_list ap)
{
char buf[128];
vsnprintf(buf, sizeof(buf), pstr, ap);
print(buf);
}
void SMACCMUARTDriver::vprintf_P(const prog_char *pstr, va_list ap)
{
vprintf(pstr, ap);
}
/* SMACCM implementations of Stream virtual methods */
int16_t SMACCMUARTDriver::available()
{
return (int16_t)usart_available(m_dev);
}
int16_t SMACCMUARTDriver::txspace()
{
return (int16_t)usart_txspace(m_dev);
}
// It looks like this should always be a non-blocking read, so return
// -1 if there is nothing to receive immediately.
int16_t SMACCMUARTDriver::read()
{
uint8_t c;
if (usart_read_timeout(m_dev, 0, &c, 1) == 0)
return -1;
return (int16_t)c;
}
int16_t SMACCMUARTDriver::peek()
{
uint8_t c;
if (!usart_peek(m_dev, &c))
return -1;
return (int16_t)c;
}
/* SMACCM implementations of Print virtual methods */
size_t SMACCMUARTDriver::write(uint8_t c)
{
portTickType delay = m_blocking ? portMAX_DELAY : 0;
return usart_write_timeout(m_dev, delay, &c, 1);
}