291 lines
7 KiB
C
291 lines
7 KiB
C
/*
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Copyright 2010,2011,2012,2013,2019 Jun WAKO <wakojun@gmail.com>
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This software is licensed with a Modified BSD License.
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All of this is supposed to be Free Software, Open Source, DFSG-free,
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GPL-compatible, and OK to use in both free and proprietary applications.
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Additions and corrections to this file are welcome.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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distribution.
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* Neither the name of the copyright holders nor the names of
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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/*
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* IBM PC keyboard protocol
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*/
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#include <stdbool.h>
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#include <avr/interrupt.h>
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#include "ringbuf.h"
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#include "ibmpc.h"
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#include "debug.h"
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#include "timer.h"
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#include "wait.h"
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#define WAIT(stat, us, err) do { \
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if (!wait_##stat(us)) { \
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ibmpc_error = err; \
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goto ERROR; \
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} \
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} while (0)
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#define BUF_SIZE 16
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static uint8_t buf[BUF_SIZE];
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static ringbuf_t rb = {
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.buffer = buf,
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.head = 0,
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.tail = 0,
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.size_mask = BUF_SIZE - 1
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};
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volatile uint8_t ibmpc_protocol = IBMPC_PROTOCOL_AT;
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volatile uint8_t ibmpc_error = IBMPC_ERR_NONE;
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void ibmpc_host_init(void)
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{
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// initialize reset pin
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IBMPC_RST_PORT |= (1<<IBMPC_RST_BIT1);
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IBMPC_RST_DDR |= (1<<IBMPC_RST_BIT1);
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IBMPC_RST_PORT |= (1<<IBMPC_RST_BIT2);
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IBMPC_RST_DDR |= (1<<IBMPC_RST_BIT2);
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inhibit();
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IBMPC_INT_INIT();
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IBMPC_INT_OFF();
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}
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void ibmpc_host_enable(void)
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{
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IBMPC_INT_ON();
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idle();
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}
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void ibmpc_host_disable(void)
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{
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// TODO: test order? uneeded interrupt happens by making clock lo
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inhibit();
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IBMPC_INT_OFF();
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}
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int16_t ibmpc_host_send(uint8_t data)
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{
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bool parity = true;
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ibmpc_error = IBMPC_ERR_NONE;
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if (ibmpc_protocol == IBMPC_PROTOCOL_XT) return -1;
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dprintf("w%02X ", data);
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IBMPC_INT_OFF();
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/* terminate a transmission if we have */
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inhibit();
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wait_us(100); // 100us [4]p.13, [5]p.50
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/* 'Request to Send' and Start bit */
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data_lo();
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clock_hi();
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WAIT(clock_lo, 10000, 1); // 10ms [5]p.50
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/* Data bit[2-9] */
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for (uint8_t i = 0; i < 8; i++) {
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wait_us(15);
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if (data&(1<<i)) {
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parity = !parity;
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data_hi();
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} else {
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data_lo();
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}
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WAIT(clock_hi, 50, 2);
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WAIT(clock_lo, 50, 3);
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}
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/* Parity bit */
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wait_us(15);
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if (parity) { data_hi(); } else { data_lo(); }
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WAIT(clock_hi, 50, 4);
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WAIT(clock_lo, 50, 5);
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/* Stop bit */
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wait_us(15);
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data_hi();
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/* Ack */
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WAIT(data_lo, 50, 6);
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WAIT(clock_lo, 50, 7);
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/* wait for idle state */
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WAIT(clock_hi, 50, 8);
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WAIT(data_hi, 50, 9);
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// clear buffer to get response correctly
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ringbuf_reset(&rb);
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ibmpc_host_isr_clear();
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idle();
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IBMPC_INT_ON();
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return ibmpc_host_recv_response();
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ERROR:
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ibmpc_error |= IBMPC_ERR_SEND;
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idle();
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IBMPC_INT_ON();
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return -1;
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}
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int16_t ibmpc_host_recv_response(void)
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{
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// Command may take 25ms/20ms at most([5]p.46, [3]p.21)
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uint8_t retry = 25;
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while (retry-- && ringbuf_is_empty(&rb)) {
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wait_ms(1);
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}
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int16_t data = ringbuf_get(&rb);
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if (data != -1) dprintf("r%02X ", data);
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return data;
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}
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/* get data received by interrupt */
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int16_t ibmpc_host_recv(void)
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{
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int16_t data = ringbuf_get(&rb);
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if (data != -1) dprintf("r%02X ", data);
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return data;
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}
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/*
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* Receive data from keyboard with ISR
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*/
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static enum {
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START,
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BIT0, BIT1, BIT2, BIT3, BIT4, BIT5, BIT6, BIT7,
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PARITY,
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STOP, } isr_state = START;
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static uint8_t isr_data = 0;
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static uint8_t isr_parity = 1;
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static uint16_t isr_time = 0;
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void ibmpc_host_isr_clear(void)
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{
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isr_state = START;
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isr_data = 0;
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isr_parity = 1;
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isr_time = 0;
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}
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ISR(IBMPC_INT_VECT)
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{
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uint8_t dbit = IBMPC_DATA_PIN&(1<<IBMPC_DATA_BIT);
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// Reset state when taking more than 1ms
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if (isr_time && timer_elapsed(isr_time) > 1) {
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ibmpc_error = IBMPC_ERR_TIMEOUT | IBMPC_ERR_RECV | isr_state;
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isr_state = START;
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isr_data = 0;
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isr_parity = 1;
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}
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isr_time = timer_read();
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switch (isr_state) {
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case START:
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if (ibmpc_protocol == IBMPC_PROTOCOL_XT) {
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// ignore start(0) bit
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if (!dbit) return;
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} else {
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if (dbit)
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goto ERROR;
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}
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break;
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case BIT0:
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case BIT1:
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case BIT2:
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case BIT3:
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case BIT4:
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case BIT5:
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case BIT6:
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case BIT7:
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isr_data >>= 1;
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if (dbit) {
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isr_data |= 0x80;
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isr_parity++;
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}
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if (isr_state == BIT7 && ibmpc_protocol == IBMPC_PROTOCOL_XT) {
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if (!ringbuf_put(&rb, isr_data)) {
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ibmpc_error = IBMPC_ERR_FULL;
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goto ERROR;
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}
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ibmpc_error = IBMPC_ERR_NONE;
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goto DONE;
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}
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break;
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case PARITY:
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if (dbit) {
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if (!(isr_parity & 0x01))
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goto ERROR;
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} else {
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if (isr_parity & 0x01)
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goto ERROR;
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}
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break;
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case STOP:
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if (!dbit)
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goto ERROR;
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if (!ringbuf_put(&rb, isr_data)) {
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ibmpc_error = IBMPC_ERR_FULL;
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goto ERROR;
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}
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ibmpc_error = IBMPC_ERR_NONE;
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goto DONE;
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break;
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default:
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goto ERROR;
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}
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goto NEXT;
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ERROR:
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ibmpc_error |= isr_state;
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ibmpc_error |= IBMPC_ERR_RECV;
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ringbuf_reset(&rb);
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DONE:
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isr_state = START;
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isr_data = 0;
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isr_parity = 1;
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isr_time = 0;
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return;
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NEXT:
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isr_state++;
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return;
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}
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/* send LED state to keyboard */
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void ibmpc_host_set_led(uint8_t led)
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{
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ibmpc_host_send(0xED);
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ibmpc_host_send(led);
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}
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