nuclear@2: #include <avr/io.h>
nuclear@2: #include <avr/interrupt.h>
nuclear@2: #include <util/delay.h>
nuclear@2: #include "ps2kbd.h"
nuclear@2: #include "defs.h"
nuclear@2: 
nuclear@2: #define BUF_SZ	16
nuclear@2: #define BUF_IDX_MASK	(BUF_SZ - 1)
nuclear@2: #define NEXT_IDX(x) (((x) + 1) & BUF_IDX_MASK)
nuclear@2: static volatile unsigned char keybuf[BUF_SZ];
nuclear@2: static volatile unsigned char key_rd, key_wr;
nuclear@2: 
nuclear@2: static volatile int sending;
nuclear@2: 
nuclear@2: void ps2write(unsigned char c)
nuclear@2: {
nuclear@2: #if 0
nuclear@2: 	int i;
nuclear@2: 	unsigned short out = (unsigned short)c | ((unsigned short)(parity_even_bit(c) & 1) << 8);
nuclear@2: 
nuclear@2: 	/* pull clock low for >60us */
nuclear@2: 	PS2LOW(BIT_CLK);
nuclear@2: 	_delay_us(60);
nuclear@2: 
nuclear@2: 	/* then pull data low and release clock */
nuclear@2: 	PS2LOW(BIT_DATA);
nuclear@2: 	PS2REL(BIT_CLK);
nuclear@2: 
nuclear@2: 	for(i=0; i<9; i++) {
nuclear@2: 		while(PINB & BIT_CLK);	/* wait for kbd to drive the clock low */
nuclear@2: 		PORTB |= out & 1;
nuclear@2: 		out >>= 1;
nuclear@2: 		while(!(PINB & BIT_CLK));	/* wait for kbd to drive the clock high */
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	PS2REL(BIT_DATA);
nuclear@2: 	/* wait for ack */
nuclear@2: 	while(PINB & BIT_DATA);
nuclear@2: 	while(!(PINB & BIT_DATA));
nuclear@2: #endif
nuclear@2: }
nuclear@2: 
nuclear@2: unsigned char ps2read(void)
nuclear@2: {
nuclear@2: 	unsigned char key;
nuclear@2: 
nuclear@2: 	while(key_rd == key_wr) {
nuclear@2: 	}
nuclear@2: 
nuclear@2: 	cli();
nuclear@2: 	key = keybuf[key_rd];
nuclear@2: 	key_rd = NEXT_IDX(key_rd);
nuclear@2: 	sei();
nuclear@2: 
nuclear@2: 	return key;
nuclear@2: }
nuclear@2: 
nuclear@2: int ps2pending(void)
nuclear@2: {
nuclear@2: 	return key_rd != key_wr;
nuclear@2: }
nuclear@2: 
nuclear@2: ISR(INT0_vect)
nuclear@2: {
nuclear@2: 	static unsigned char value, parity;
nuclear@2: 	/*static unsigned char valp;*/
nuclear@2: 	static int nbits;
nuclear@2: 
nuclear@2: 	if(sending) {
nuclear@2: 	} else {
nuclear@2: 		if(nbits > 0 && nbits < 9) {
nuclear@2: 			value >>= 1;
nuclear@2: 			if(PIND & PDATA_BIT) {
nuclear@2: 				value |= 0x80;
nuclear@2: 				parity ^= 1;
nuclear@2: 			}
nuclear@2: 		}/* else if(nbits == 9) {
nuclear@2: 			valp = (PIND >> PDATA) & 1;
nuclear@2: 		}*/
nuclear@2: 		if(++nbits >= 11) {
nuclear@2: 			nbits = 0;
nuclear@2: 
nuclear@2: 			/* check parity */
nuclear@2: 			/*if((parity & 1) == (valp & 1)) {}*/
nuclear@2: 			keybuf[key_wr] = (unsigned char)value;
nuclear@2: 			key_wr = NEXT_IDX(key_wr);
nuclear@2: 
nuclear@2: 			value = 0;
nuclear@2: 			parity = 0;
nuclear@2: 		}
nuclear@2: 	}
nuclear@2: }