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/*
* This file is part of the libopencm3_cpp_extensions project.
* hosted at http://github.com/thirdpin/libopencm3_cpp_extensions
*
* Copyright (C) 2016 Third Pin LLC
* Written by Anastasiia Lazareva <a.lazareva@thirdpin.ru>
*
* 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 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 General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
RS485 implementation, public interface
*/
#ifndef RS_485_H
#define RS_485_H
#include <stdint.h>
#include <libopencm3/stm32/usart.h>
#ifdef STM32F2
#include <libopencm3/stm32/f2/nvic.h>
#endif
#ifdef STM32F4
#include <libopencm3/stm32/f4/nvic.h>
#endif
#include "gpio.hpp"
#include "private/assert.h"
#include "utils/round_buffer.hpp"
namespace cm3cpp {
class RS485
{
public:
using Gpio = gpio::Gpio;
struct Settings
{
uint32_t baud_rate;
uint16_t word_length;
uint16_t stop_bits;
uint16_t parity;
uint16_t mode;
uint16_t flow_control;
};
struct Struct
{
uint32_t number;
Gpio::Pinout tx;
Gpio::Pinout rx;
Gpio::Pinout de;
};
utils::RoundBuffer* rb_in;
utils::RoundBuffer* rb_out;
RS485(Struct rs485,
Settings settings,
utils::RoundBuffer rb_in_size,
utils::RoundBuffer rb_out_size);
CM3CPP_EXPLISIT_DESTRUCTOR(RS485)
void usart_enable_tc_interrupt() { USART_CR1(_rs485) |= USART_CR1_TCIE; }
void usart_disable_tc_interrupt() { USART_CR1(_rs485) &= ~USART_CR1_TCIE; }
bool interrupt_source_RXNE()
{
return (((USART_CR1(_rs485) & USART_CR1_RXNEIE) != 0) &&
usart_get_flag(_rs485, USART_SR_RXNE));
}
bool interrupt_source_TXE()
{
return (((USART_CR1(_rs485) & USART_CR1_TXEIE) != 0) &&
usart_get_flag(_rs485, USART_SR_TXE));
}
bool interrupt_source_TC()
{
return (((USART_CR1(_rs485) & USART_CR1_TCIE) != 0) &&
usart_get_flag(_rs485, USART_SR_TC));
}
void start_send()
{
_de.set();
usart_enable_tx_interrupt(_rs485);
}
void receive_handler()
{
if (interrupt_source_RXNE()) {
rb_in->push(usart_recv(_rs485));
}
}
void transmit_handler()
{
if (interrupt_source_TXE()) {
if (rb_out->get_count()) {
usart_send(_rs485, rb_out->pop());
}
else {
usart_disable_tx_interrupt(_rs485);
usart_enable_tc_interrupt();
}
}
if (interrupt_source_TC()) {
_de.clear();
usart_disable_tc_interrupt();
}
}
void inirq()
{
receive_handler();
transmit_handler();
}
private:
uint32_t _rs485;
gpio::Gpio _de;
};
} // namespace cm3cpp
#endif
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