mirror of
https://github.com/eddyem/stm32samples.git
synced 2025-12-06 10:45:11 +03:00
87 lines
2.3 KiB
C
87 lines
2.3 KiB
C
/*
|
|
* This file is part of the pl2303 project.
|
|
* Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
|
|
*
|
|
* 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/>.
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include <stm32f3.h>
|
|
|
|
#include "ringbuffer.h"
|
|
#include "usb.h"
|
|
#include "usb_lib.h"
|
|
|
|
// ring buffer
|
|
static char ringbuffer[RBSIZE];
|
|
// head - position of first data byte
|
|
// tail - position of last data byte + 1
|
|
// head == tail - empty! So, buffer can't store more than RBSIZE-1 bytes of data!
|
|
static volatile int head = 0, tail = 0;
|
|
|
|
static int datalen(){
|
|
if(tail >= head) return (tail - head);
|
|
else return (RBSIZE - head + tail);
|
|
}
|
|
static int restlen(){
|
|
return (RBSIZE - 1 - datalen());
|
|
}
|
|
|
|
TRUE_INLINE void incr(volatile int *what, int n){
|
|
*what += n;
|
|
if(*what >= RBSIZE) *what -= RBSIZE;
|
|
}
|
|
|
|
int RB_read(char s[BLOCKSIZE]){
|
|
int l = datalen();
|
|
if(!l) return 0;
|
|
if(l > BLOCKSIZE) l = BLOCKSIZE;
|
|
int _1st = RBSIZE - head;
|
|
if(_1st > l) _1st = l;
|
|
if(_1st > BLOCKSIZE) _1st = BLOCKSIZE;
|
|
memcpy(s, ringbuffer+head, _1st);
|
|
if(_1st < BLOCKSIZE && l > _1st){
|
|
memcpy(s+_1st, ringbuffer, l-_1st);
|
|
incr(&head, l);
|
|
return l;
|
|
}
|
|
incr(&head ,_1st);
|
|
return _1st;
|
|
}
|
|
|
|
static int addportion(const char *str, int l){
|
|
int r = restlen();
|
|
if(l > r) l = r;
|
|
if(!l) return 0;
|
|
int _1st = RBSIZE - tail;
|
|
if(_1st > l) _1st = l;
|
|
memcpy(ringbuffer+tail, str, _1st);
|
|
if(_1st < l){ // add another piece from start
|
|
memcpy(ringbuffer, str+_1st, l-_1st);
|
|
}
|
|
incr(&tail, l);
|
|
return l;
|
|
}
|
|
|
|
void RB_write(const char *str, int l){
|
|
if(!str || !*str) return;
|
|
if(!usbON) return;
|
|
while(l){
|
|
send_next();
|
|
int a = addportion(str, l);
|
|
l -= a;
|
|
str += a;
|
|
}
|
|
}
|