tmk_core/ring_buffer.h

   1 #ifndef RING_BUFFER_H
   2 #define RING_BUFFER_H
   3 /*--------------------------------------------------------------------
   4  * Ring buffer to store scan codes from keyboard
   5  *------------------------------------------------------------------*/
   6 #define RBUF_SIZE 32
   7 #include <util/atomic.h>
   8 static uint8_t     rbuf[RBUF_SIZE];
   9 static uint8_t     rbuf_head = 0;
  10 static uint8_t     rbuf_tail = 0;
  11 static inline void rbuf_enqueue(uint8_t data) {
  12     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  13         uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
  14         if (next != rbuf_tail) {
  15             rbuf[rbuf_head] = data;
  16             rbuf_head       = next;
  17         } else {
  18             print("rbuf: full\n");
  19         }
  20     }
  21 }
  22 static inline uint8_t rbuf_dequeue(void) {
  23     uint8_t val = 0;
  24     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  25         if (rbuf_head != rbuf_tail) {
  26             val       = rbuf[rbuf_tail];
  27             rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
  28         }
  29     }
  30
  31     return val;
  32 }
  33 static inline bool rbuf_has_data(void) {
  34     bool has_data;
  35     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { has_data = (rbuf_head != rbuf_tail); }
  36     return has_data;
  37 }
  38 static inline void rbuf_clear(void) {
  39     ATOMIC_BLOCK(ATOMIC_RESTORESTATE) { rbuf_head = rbuf_tail = 0; }
  40 }
  41
  42 #endif /* RING_BUFFER_H */