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@3: #include "timer.h"
nuclear@3: 
nuclear@3: #define TIMEOUT	100
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@3: static volatile int send_nbits, wait_ack;
nuclear@3: static volatile unsigned char send_val, send_par;
nuclear@2: 
nuclear@3: static void abort_send(void);
nuclear@3: 
nuclear@3: int ps2write(unsigned char c)
nuclear@2: {
nuclear@3: 	cli();
nuclear@3: 	send_nbits = 10;
nuclear@3: 	send_val = c;
nuclear@3: 	send_par = 0;	/* init to 0, will be calculated while sending */
nuclear@2: 
nuclear@3: 	/* inhibit transmission, hold at least 100us */
nuclear@3: 	PORTD &= ~PCLK_BIT;
nuclear@3: 	DDRD |= PCLK_BIT;
nuclear@3: 	EIFR |= (1 << INTF0);	/* clear pending interrupt due to clock transition */
nuclear@3: 	sei();
nuclear@3: 	_delay_us(100);
nuclear@2: 
nuclear@3: 	/* RTS by data low & release clock (this counts as start bit?) */
nuclear@3: 	PORTD &= ~PDATA_BIT;
nuclear@3: 	DDRD |= PDATA_BIT;
nuclear@3: 	DDRD &= ~PCLK_BIT;
nuclear@2: 
nuclear@3: 	reset_timer();
nuclear@3: 	while(send_nbits > 0) {
nuclear@3: 		if(get_msec() > TIMEOUT) {
nuclear@3: 			abort_send();
nuclear@3: 			return -1;
nuclear@3: 		}
nuclear@2: 	}
nuclear@3: 	_delay_us(5);
nuclear@2: 
nuclear@3: 	/* release data line and wait for ack */
nuclear@3: 	cli();
nuclear@3: 	wait_ack = 1;
nuclear@3: 	sei();
nuclear@3: 	DDRD &= ~PDATA_BIT;
nuclear@3: 	reset_timer();
nuclear@3: 	while(wait_ack) {
nuclear@3: 		if(get_msec() > TIMEOUT) {
nuclear@3: 			abort_send();
nuclear@3: 			return -1;
nuclear@3: 		}
nuclear@3: 	}
nuclear@3: 	return 0;
nuclear@3: }
nuclear@3: 
nuclear@3: static void abort_send(void)
nuclear@3: {
nuclear@3: 	cli();
nuclear@3: 	send_nbits = 0;
nuclear@3: 	wait_ack = 0;
nuclear@3: 	/* hold clock low for 100us */
nuclear@3: 	PORTD &= ~PCLK_BIT;
nuclear@3: 	DDRD |= PCLK_BIT;
nuclear@3: 	_delay_us(100);
nuclear@3: 	DDRD &= ~(PCLK_BIT | PDATA_BIT);
nuclear@3: 	EIFR |= (1 << INTF0);	/* clear pending interrupt */
nuclear@3: 	sei();
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@3: int ps2wait(unsigned int timeout)
nuclear@3: {
nuclear@3: 	reset_timer();
nuclear@3: 	while(key_rd == key_wr) {
nuclear@3: 		if(get_msec() >= timeout) return -1;
nuclear@3: 	}
nuclear@3: 	return 0;
nuclear@3: }
nuclear@3: 
nuclear@3: #define PS2_ACK		0xfa
nuclear@3: #define PS2_RESEND	0xfe
nuclear@3: #define PS2_ECHO	0xee
nuclear@3: 
nuclear@3: int ps2setled(unsigned char state)
nuclear@3: {
nuclear@3: 	unsigned char c;
nuclear@3: 
nuclear@3: 	ps2write(0xed);
nuclear@3: 	reset_timer();
nuclear@3: 	while(!ps2pending()) {
nuclear@3: 		if(get_msec() >= TIMEOUT) return -1;
nuclear@3: 	}
nuclear@3: 	c = ps2read();
nuclear@3: 	/*printf("ps2setled 1st response: %x\r\n", (unsigned int)c);*/
nuclear@3: 	if(c != PS2_ACK) return -1;
nuclear@3: 
nuclear@3: 	ps2write(state);
nuclear@3: 	reset_timer();
nuclear@3: 	while(!ps2pending()) {
nuclear@3: 		if(get_msec() >= TIMEOUT) return -1;
nuclear@3: 	}
nuclear@3: 	c = ps2read();
nuclear@3: 	/*printf("ps2setled 2nd response: %x\r\n", (unsigned int)c);*/
nuclear@3: 	if(c != PS2_ACK) return -1;
nuclear@3: 
nuclear@3: 	return 0;
nuclear@3: }
nuclear@3: 
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@3: 	if(wait_ack) {
nuclear@3: 		if(!(PIND & PDATA_BIT)) {
nuclear@3: 			wait_ack = 0;
nuclear@3: 		}
nuclear@3: 		return;
nuclear@3: 	}
nuclear@3: 
nuclear@3: 	if(send_nbits > 0) {
nuclear@3: 		--send_nbits;
nuclear@3: 		switch(send_nbits) {
nuclear@3: 		case 1:		/* parity bit */
nuclear@3: 			if(send_par & 1) {	/* odd number of ones: parity 0 */
nuclear@3: 				PORTD &= ~PDATA_BIT;
nuclear@3: 			} else {	/* even number of ones: parity 1 */
nuclear@3: 				PORTD |= PDATA_BIT;
nuclear@3: 			}
nuclear@3: 			break;
nuclear@3: 		case 0:	/* stop bit: 1 */
nuclear@3: 			PORTD |= PDATA_BIT;
nuclear@3: 			break;
nuclear@3: 		default:
nuclear@3: 			if(send_val & 1) {
nuclear@3: 				PORTD |= PDATA_BIT;
nuclear@3: 				++send_par;
nuclear@3: 			} else {
nuclear@3: 				PORTD &= ~PDATA_BIT;
nuclear@3: 			}
nuclear@3: 			send_val >>= 1;
nuclear@3: 		}
nuclear@3: 
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: }