uart_half_duplex.c
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/*
* Copyright (C) 2017 Inria
*
* This file is subject to the terms and conditions of the GNU Lesser General
* Public License v2.1. See the file LICENSE in the top level directory for more
* details.
*/
/**
* @ingroup drivers_uart_half_duplex
* @{
*
* @file
* @brief Driver implementation for half-duplex UART devices
*
* @author Loïc Dauphin <loic.dauphin@inria.fr>
*
* @}
*/
#include "uart_half_duplex.h"
#include "periph/uart.h"
#include "periph/gpio.h"
#include "xtimer.h"
#define IS_SET(dir) ((dir & 1) == 0)
#define IS_CLEAR(dir) ((dir & 1) == 1)
#define IS_PIN(dir) (dir >= UART_HALF_DUPLEX_DIR_PIN_SET(0))
#define GET_PIN(dir) ((dir >> 1) - 1)
static inline void _enable_tx(const uart_half_duplex_t *dev)
{
if (dev->params.dir.enable_tx) {
dev->params.dir.enable_tx(dev->params.uart);
}
}
static inline void _disable_tx(const uart_half_duplex_t *dev)
{
if (dev->params.dir.disable_tx) {
dev->params.dir.disable_tx(dev->params.uart);
}
}
static void _rx_cb(void* data, uint8_t c)
{
uart_half_duplex_t *dev = data;
if (dev->size < dev->buffer_max_size) {
dev->buffer[dev->size++] = c;
}
}
int uart_half_duplex_init(uart_half_duplex_t *dev, uint8_t *buffer, size_t buffer_max_size, const uart_half_duplex_params_t *params)
{
if (buffer == NULL || buffer_max_size <= 7) {
return UART_HALF_DUPLEX_NOBUFF;
}
dev->buffer = buffer;
dev->buffer_max_size = buffer_max_size;
dev->params = *params;
dev->timeout_us = UART_HALF_DUPLEX_DEFAULT_TIMEOUT_US;
if (dev->params.dir.init) {
dev->params.dir.init(dev->params.uart);
}
int ret = uart_init(dev->params.uart, dev->params.baudrate, _rx_cb, dev);
_disable_tx(dev);
uart_half_duplex_set_rx(dev);
return ret;
}
size_t uart_half_duplex_send(const uart_half_duplex_t *dev, size_t size)
{
_enable_tx(dev);
uart_write(dev->params.uart, dev->buffer, size);
_disable_tx(dev);
return size;
}
size_t uart_half_duplex_recv(const uart_half_duplex_t *dev, size_t size)
{
const uint32_t begin = xtimer_now_usec();
while (xtimer_now_usec() - begin < dev->timeout_us) {
if (dev->size >= size) {
break;
}
}
return dev->size;
}