be4e75423a
Adopt the macros for saving/restoring the interrupt state that are provided by the avr gcc environment. Removing intialization of the timer value; this shaves off a few bytes because globals are default initialized to zero.
52 lines
1.2 KiB
C
52 lines
1.2 KiB
C
#ifndef RING_BUFFER_H
|
|
#define RING_BUFFER_H
|
|
/*--------------------------------------------------------------------
|
|
* Ring buffer to store scan codes from keyboard
|
|
*------------------------------------------------------------------*/
|
|
#define RBUF_SIZE 32
|
|
#include <util/atomic.h>
|
|
static uint8_t rbuf[RBUF_SIZE];
|
|
static uint8_t rbuf_head = 0;
|
|
static uint8_t rbuf_tail = 0;
|
|
static inline void rbuf_enqueue(uint8_t data)
|
|
{
|
|
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
|
|
uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
|
|
if (next != rbuf_tail) {
|
|
rbuf[rbuf_head] = data;
|
|
rbuf_head = next;
|
|
} else {
|
|
print("rbuf: full\n");
|
|
}
|
|
}
|
|
}
|
|
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;
|
|
}
|
|
}
|
|
|
|
#endif /* RING_BUFFER_H */
|