46 lines
1.3 KiB
C
46 lines
1.3 KiB
C
#pragma once
|
|
|
|
/*--------------------------------------------------------------------
|
|
* Ring buffer to store scan codes from keyboard
|
|
*------------------------------------------------------------------*/
|
|
#ifndef RBUF_SIZE
|
|
# define RBUF_SIZE 32
|
|
#endif
|
|
#include <util/atomic.h>
|
|
#include <stdint.h>
|
|
#include <stdbool.h>
|
|
static uint8_t rbuf[RBUF_SIZE];
|
|
static uint8_t rbuf_head = 0;
|
|
static uint8_t rbuf_tail = 0;
|
|
static inline bool rbuf_enqueue(uint8_t data) {
|
|
bool ret = false;
|
|
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
|
|
uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
|
|
if (next != rbuf_tail) {
|
|
rbuf[rbuf_head] = data;
|
|
rbuf_head = next;
|
|
ret = true;
|
|
}
|
|
}
|
|
return ret;
|
|
}
|
|
static inline uint8_t rbuf_dequeue(void) {
|
|
uint8_t val = 0;
|
|
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
|
|
if (rbuf_head != rbuf_tail) {
|
|
val = rbuf[rbuf_tail];
|
|
rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
|
|
}
|
|
}
|
|
|
|
return val;
|
|
}
|
|
static inline bool rbuf_has_data(void) {
|
|
bool has_data;
|
|
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { has_data = (rbuf_head != rbuf_tail); }
|
|
return has_data;
|
|
}
|
|
static inline void rbuf_clear(void) {
|
|
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { rbuf_head = rbuf_tail = 0; }
|
|
}
|