qemu-e2k/hw/parallel.c

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/*
* QEMU Parallel PORT emulation
*
* Copyright (c) 2003-2005 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "vl.h"
//#define DEBUG_PARALLEL
/*
* These are the definitions for the Printer Status Register
*/
#define PARA_STS_BUSY 0x80 /* Busy complement */
#define PARA_STS_ACK 0x40 /* Acknowledge */
#define PARA_STS_PAPER 0x20 /* Out of paper */
#define PARA_STS_ONLINE 0x10 /* Online */
#define PARA_STS_ERROR 0x08 /* Error complement */
/*
* These are the definitions for the Printer Control Register
*/
#define PARA_CTR_INTEN 0x10 /* IRQ Enable */
#define PARA_CTR_SELECT 0x08 /* Select In complement */
#define PARA_CTR_INIT 0x04 /* Initialize Printer complement */
#define PARA_CTR_AUTOLF 0x02 /* Auto linefeed complement */
#define PARA_CTR_STROBE 0x01 /* Strobe complement */
struct ParallelState {
uint8_t data;
uint8_t status; /* read only register */
uint8_t control;
int irq;
int irq_pending;
CharDriverState *chr;
int hw_driver;
};
static void parallel_update_irq(ParallelState *s)
{
if (s->irq_pending)
pic_set_irq(s->irq, 1);
else
pic_set_irq(s->irq, 0);
}
static void parallel_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
ParallelState *s = opaque;
addr &= 7;
#ifdef DEBUG_PARALLEL
printf("parallel: write addr=0x%02x val=0x%02x\n", addr, val);
#endif
switch(addr) {
case 0:
if (s->hw_driver) {
s->data = val;
qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_WRITE_DATA, &s->data);
} else {
s->data = val;
parallel_update_irq(s);
}
break;
case 2:
if (s->hw_driver) {
s->control = val;
qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_WRITE_CONTROL, &s->control);
} else {
if ((val & PARA_CTR_INIT) == 0 ) {
s->status = PARA_STS_BUSY;
s->status |= PARA_STS_ACK;
s->status |= PARA_STS_ONLINE;
s->status |= PARA_STS_ERROR;
}
else if (val & PARA_CTR_SELECT) {
if (val & PARA_CTR_STROBE) {
s->status &= ~PARA_STS_BUSY;
if ((s->control & PARA_CTR_STROBE) == 0)
qemu_chr_write(s->chr, &s->data, 1);
} else {
if (s->control & PARA_CTR_INTEN) {
s->irq_pending = 1;
}
}
}
parallel_update_irq(s);
s->control = val;
}
break;
}
}
static uint32_t parallel_ioport_read(void *opaque, uint32_t addr)
{
ParallelState *s = opaque;
uint32_t ret = 0xff;
addr &= 7;
switch(addr) {
case 0:
if (s->hw_driver) {
qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_DATA, &s->data);
}
ret = s->data;
break;
case 1:
if (s->hw_driver) {
qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_STATUS, &s->status);
ret = s->status;
} else {
ret = s->status;
s->irq_pending = 0;
if ((s->status & PARA_STS_BUSY) == 0 && (s->control & PARA_CTR_STROBE) == 0) {
/* XXX Fixme: wait 5 microseconds */
if (s->status & PARA_STS_ACK)
s->status &= ~PARA_STS_ACK;
else {
/* XXX Fixme: wait 5 microseconds */
s->status |= PARA_STS_ACK;
s->status |= PARA_STS_BUSY;
}
}
parallel_update_irq(s);
}
break;
case 2:
if (s->hw_driver) {
qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_CONTROL, &s->control);
}
ret = s->control;
break;
}
#ifdef DEBUG_PARALLEL
printf("parallel: read addr=0x%02x val=0x%02x\n", addr, ret);
#endif
return ret;
}
/* If fd is zero, it means that the parallel device uses the console */
ParallelState *parallel_init(int base, int irq, CharDriverState *chr)
{
ParallelState *s;
uint8_t dummy;
s = qemu_mallocz(sizeof(ParallelState));
if (!s)
return NULL;
s->chr = chr;
s->hw_driver = 0;
if (qemu_chr_ioctl(chr, CHR_IOCTL_PP_READ_STATUS, &dummy) == 0)
s->hw_driver = 1;
s->irq = irq;
s->data = 0;
s->status = PARA_STS_BUSY;
s->status |= PARA_STS_ACK;
s->status |= PARA_STS_ONLINE;
s->status |= PARA_STS_ERROR;
s->control = PARA_CTR_SELECT;
s->control |= PARA_CTR_INIT;
register_ioport_write(base, 8, 1, parallel_ioport_write, s);
register_ioport_read(base, 8, 1, parallel_ioport_read, s);
return s;
}