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 {
  13   ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  14     uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
  15     if (next != rbuf_tail) {
  16         rbuf[rbuf_head] = data;
  17         rbuf_head = next;
  18     } else {
  19         print("rbuf: full\n");
  20     }
  21   }
  22 }
  23 static inline uint8_t rbuf_dequeue(void)
  24 {
  25     uint8_t val = 0;
  26   ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  27
  28     if (rbuf_head != rbuf_tail) {
  29         val = rbuf[rbuf_tail];
  30         rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE;
  31     }
  32   }
  33
  34     return val;
  35 }
  36 static inline bool rbuf_has_data(void)
  37 {
  38   bool has_data;
  39   ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  40     has_data = (rbuf_head != rbuf_tail);
  41   }
  42   return has_data;
  43 }
  44 static inline void rbuf_clear(void)
  45 {
  46   ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
  47     rbuf_head = rbuf_tail = 0;
  48   }
  49 }
  50
  51 #endif  /* RING_BUFFER_H */