58 lines
1.2 KiB
C
58 lines
1.2 KiB
C
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/*--------------------------------------------------------------------
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* Ring buffer to store scan codes from keyboard
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*------------------------------------------------------------------*/
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#ifndef PBUFF_H
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#define PBUFF_H
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#include "print.h"
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#define PBUF_SIZE 32
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static uint16_t pbuf[PBUF_SIZE];
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static uint16_t pbuf_head = 0;
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static uint16_t pbuf_tail = 0;
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static inline void pbuf_enqueue(uint16_t data)
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{
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uint8_t sreg = SREG;
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cli();
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uint16_t next = (pbuf_head + 1) % PBUF_SIZE;
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if (next != pbuf_tail) {
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pbuf[pbuf_head] = data;
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pbuf_head = next;
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} else {
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print("pbuf: full\n");
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}
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SREG = sreg;
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}
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static inline uint16_t pbuf_dequeue(void)
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{
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uint16_t val = 0;
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uint8_t sreg = SREG;
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cli();
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if (pbuf_head != pbuf_tail) {
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val = pbuf[pbuf_tail];
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pbuf_tail = (pbuf_tail + 1) % PBUF_SIZE;
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}
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SREG = sreg;
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return val;
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}
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static inline bool pbuf_has_data(void)
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{
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uint8_t sreg = SREG;
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cli();
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bool has_data = (pbuf_head != pbuf_tail);
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SREG = sreg;
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return has_data;
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}
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static inline void pbuf_clear(void)
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{
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uint8_t sreg = SREG;
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cli();
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pbuf_head = pbuf_tail = 0;
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SREG = sreg;
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}
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#endif
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