GRBL-Advanced/HAL/USART/FIFO_USART.c

115 wiersze
2.8 KiB
C

/*
FIFO_USART.c - FIFO USART Implementation
Part of STM32F4_HAL
Copyright (c) 2016-2017 Patrick F.
STM32F4_HAL 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.
STM32F4_HAL 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 STM32F4_HAL. If not, see <http://www.gnu.org/licenses/>.
*/
/* Very simple queue
* These are FIFO queues which discard the new data when full.
*
* Queue is empty when in == out.
* If in != out, then
* - items are placed into in before incrementing in
* - items are removed from out before incrementing out
* Queue is full when in == (out-1 + QUEUE_SIZE) % QUEUE_SIZE;
*
* The queue will hold QUEUE_ELEMENTS number of items before the
* calls to FifoUsart_Insert fail.
*/
#include <string.h>
#include "FIFO_USART.h"
#include "debug.h"
static char FifoQueue[USART_NUM][2][QUEUE_SIZE];
static uint8_t QueueIn[2][USART_NUM], QueueOut[2][USART_NUM];
static uint32_t Count[USART_NUM] = {0};
void FifoUsart_Init(void)
{
memset(QueueIn, 0, sizeof(QueueIn));
memset(QueueOut, 0, sizeof(QueueOut));
memset(Count, 0, sizeof(Count));
}
int8_t FifoUsart_Insert(uint8_t usart, uint8_t direction, char ch)
{
if(usart >= USART_NUM) {
d_printf("ERROR: Wrong USART %d\n", usart);
return -1;
}
if(direction > 1) {
d_printf("ERROR: USART direction out of range\n");
return -1;
}
if(QueueIn[direction][usart] == ((QueueOut[direction][usart] - 1 + QUEUE_SIZE) % QUEUE_SIZE))
{
return -1; // Queue Full
}
FifoQueue[usart][direction][QueueIn[direction][usart]] = ch;
QueueIn[direction][usart] = (QueueIn[direction][usart] + 1) % QUEUE_SIZE;
Count[usart]++;
return 0; // No errors
}
int8_t FifoUsart_Get(uint8_t usart, uint8_t direction, char *ch)
{
if(usart >= USART_NUM) {
d_printf("ERROR: Wrong USART %d\n", usart);
return -1;
}
if(direction > 1) {
d_printf("ERROR: USART direction out of range\n");
return -1;
}
if(QueueIn[direction][usart] == QueueOut[direction][usart])
{
return -1; /* Queue Empty - nothing to get*/
}
*ch = FifoQueue[usart][direction][QueueOut[direction][usart]];
QueueOut[direction][usart] = (QueueOut[direction][usart] + 1) % QUEUE_SIZE;
Count[usart]--;
return 0; // No errors
}
uint32_t FifoUsart_Available(uint8_t usart)
{
if(usart >= USART_NUM) {
d_printf("ERROR: Wrong USART %d\n", usart);
return 0xFFFFFFFF;
}
return (QUEUE_ELEMENTS - Count[usart]);
}