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Fix ibm4704 protocol with using interrupt

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This commit is contained in:
tmk 2014-10-27 21:39:02 +09:00 • committed by Jun Wako
parent 5ea50bfb30
commit d42aa47809
4 changed files with 152 additions and 85 deletions
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141
tmk_core/protocol/ibm4704.c
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@ -4,6 +4,7 @@ Copyright 2010,2011,2012,2013 Jun WAKO <wakojun@gmail.com>
#include <stdbool.h>
#include <util/delay.h>
#include "debug.h"
#include "ring_buffer.h"
#include "ibm4704.h"
@ -20,7 +21,9 @@ uint8_t ibm4704_error = 0;
void ibm4704_init(void)
{
inhibit();
IBM4704_INT_INIT();
IBM4704_INT_ON();
idle();
}
/*
@ -47,6 +50,8 @@ uint8_t ibm4704_send(uint8_t data)
bool parity = true; // odd parity
ibm4704_error = 0;
IBM4704_INT_OFF();
/* Request to send */
idle();
clock_lo();
@ -57,7 +62,6 @@ uint8_t ibm4704_send(uint8_t data)
/* Data bit */
for (uint8_t i = 0; i < 8; i++) {
WAIT(clock_hi, 100, 0x40+i);
//_delay_us(5);
if (data&(1<<i)) {
parity = !parity;
data_hi();
@ -79,28 +83,25 @@ uint8_t ibm4704_send(uint8_t data)
/* End */
WAIT(data_lo, 100, 0x36);
inhibit();
_delay_us(200); // wait to recover clock to hi
idle();
IBM4704_INT_ON();
return 0;
ERROR:
inhibit();
if (ibm4704_error >= 0x30) {
xprintf("x%02X ", ibm4704_error);
idle();
if (ibm4704_error > 0x30) {
xprintf("S:%02X ", ibm4704_error);
}
_delay_us(200); // wait to recover clock to hi
IBM4704_INT_ON();
return -1;
}
/* receive data when host want else inhibit communication */
/* wait forever to receive data */
uint8_t ibm4704_recv_response(void)
{
// 250 * 100us(wait start bit in ibm4704_recv)
uint8_t data = 0;
uint8_t try = 250;
do {
data = ibm4704_recv();
} while (try-- && ibm4704_error);
return data;
while (!rbuf_has_data()) {
_delay_ms(1);
}
return rbuf_dequeue();
}
/*
@ -121,49 +122,69 @@ Stop bit: Keyboard pulls down Data line to lo after 9th clock.
*/
uint8_t ibm4704_recv(void)
{
uint8_t data = 0;
bool parity = true; // odd parity
ibm4704_error = IBM4704_ERR_NONE;
idle();
_delay_us(5); // wait for line settles
/* start bit */
WAIT(clock_lo, 100, 0x11); // wait for keyboard to send
WAIT(data_hi, 100, 0x12); // can be delayed that long
WAIT(clock_hi, 100, 0x13); // first rising edge which can take longer
/* data */
for (uint8_t i = 0; i < 8; i++) {
WAIT(clock_hi, 100, 0x20+i);
//_delay_us(5);
if (data_in()) {
parity = !parity;
data |= (1<<i);
}
WAIT(clock_lo, 150, 0x28+i);
if (rbuf_has_data()) {
return rbuf_dequeue();
} else {
return -1;
}
/* parity */
WAIT(clock_hi, 100, 0x17);
if (data_in() != parity) {
ibm4704_error = IBM4704_ERR_PARITY;
goto ERROR;
}
WAIT(clock_lo, 150, 0x18);
/* stop bit */
WAIT(clock_hi, 100, 0x19);
WAIT(data_lo, 1, 0x19);
inhibit();
_delay_us(200); // wait to recover clock to hi
return data;
ERROR:
if (ibm4704_error > 0x12) {
xprintf("x%02X ", ibm4704_error);
}
inhibit();
_delay_us(200); // wait to recover clock to hi
return -1;
}
ISR(IBM4704_INT_VECT)
{
static enum {
INIT, START, BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7, PARITY,
} state = INIT;
// LSB first
static uint8_t data = 0;
// Odd parity
static uint8_t parity = false;
ibm4704_error = 0;
// return unless falling edge
if (clock_in()) { goto RETURN; } // why this occurs?
state++;
switch (state) {
case START:
// Data:Low
WAIT(data_hi, 10, state);
break;
case BIT0:
case BIT1:
case BIT2:
case BIT3:
case BIT4:
case BIT5:
case BIT6:
case BIT7:
data >>= 1;
if (data_in()) {
data |= 0x80;
parity = !parity;
}
break;
case PARITY:
if (data_in()) {
parity = !parity;
}
if (!parity)
goto ERROR;
rbuf_enqueue(data);
ibm4704_error = IBM4704_ERR_NONE;
goto DONE;
break;
default:
goto ERROR;
}
goto RETURN;
ERROR:
ibm4704_error = state;
while (ibm4704_send(0xFE)) _delay_ms(1); // resend
xprintf("R:%02X\n", data);
DONE:
state = INIT;
data = 0;
parity = false;
RETURN:
return;
}