hw/parallel.c - qemu - Git at Google

 /*
  * QEMU Parallel PORT emulation
  *
  * Copyright (c) 2003-2005 Fabrice Bellard
  * Copyright (c) 2007 Marko Kohtala
  *
  * 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 "hw.h"
 #include "qemu-char.h"
 #include "isa.h"
 #include "pc.h"

 //#define DEBUG_PARALLEL

 #ifdef DEBUG_PARALLEL
 #define pdebug(fmt, ...) printf("pp: " fmt, ## __VA_ARGS__)
 #else
 #define pdebug(fmt, ...) ((void)0)
 #endif

 #define PARA_REG_DATA 0
 #define PARA_REG_STS 1
 #define PARA_REG_CTR 2
 #define PARA_REG_EPP_ADDR 3
 #define PARA_REG_EPP_DATA 4

 /*
  * 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 */
 #define PARA_STS_TMOUT	0x01	/* EPP timeout */

 /*
  * These are the definitions for the Printer Control Register
  */
 #define PARA_CTR_DIR	0x20	/* Direction (1=read, 0=write) */
 #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 */

 #define PARA_CTR_SIGNAL (PARA_CTR_SELECT|PARA_CTR_INIT|PARA_CTR_AUTOLF|PARA_CTR_STROBE)

 struct ParallelState {
     uint8_t dataw;
     uint8_t datar;
     uint8_t status;
     uint8_t control;
     qemu_irq irq;
     int irq_pending;
     CharDriverState *chr;
     int hw_driver;
     int epp_timeout;
     uint32_t last_read_offset; /* For debugging */
     /* Memory-mapped interface */
     int it_shift;
 };

 static void parallel_update_irq(ParallelState *s)
 {
     if (s->irq_pending)
         qemu_irq_raise(s->irq);
     else
         qemu_irq_lower(s->irq);
 }

 static void
 parallel_ioport_write_sw(void *opaque, uint32_t addr, uint32_t val)
 {
     ParallelState *s = opaque;

     pdebug("write addr=0x%02x val=0x%02x\n", addr, val);

     addr &= 7;
     switch(addr) {
     case PARA_REG_DATA:
         s->dataw = val;
         parallel_update_irq(s);
         break;
     case PARA_REG_CTR:
         val |= 0xc0;
         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->dataw, 1);
             } else {
                 if (s->control & PARA_CTR_INTEN) {
                     s->irq_pending = 1;
                 }
             }
         }
         parallel_update_irq(s);
         s->control = val;
         break;
     }
 }

 static void parallel_ioport_write_hw(void *opaque, uint32_t addr, uint32_t val)
 {
     ParallelState *s = opaque;
     uint8_t parm = val;
     int dir;

     /* Sometimes programs do several writes for timing purposes on old
        HW. Take care not to waste time on writes that do nothing. */

     s->last_read_offset = ~0U;

     addr &= 7;
     switch(addr) {
     case PARA_REG_DATA:
         if (s->dataw == val)
             return;
         pdebug("wd%02x\n", val);
         qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_WRITE_DATA, &parm);
         s->dataw = val;
         break;
     case PARA_REG_STS:
         pdebug("ws%02x\n", val);
         if (val & PARA_STS_TMOUT)
             s->epp_timeout = 0;
         break;
     case PARA_REG_CTR:
         val |= 0xc0;
         if (s->control == val)
             return;
         pdebug("wc%02x\n", val);

         if ((val & PARA_CTR_DIR) != (s->control & PARA_CTR_DIR)) {
             if (val & PARA_CTR_DIR) {
                 dir = 1;
             } else {
                 dir = 0;
             }
             qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_DATA_DIR, &dir);
             parm &= ~PARA_CTR_DIR;
         }

         qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_WRITE_CONTROL, &parm);
         s->control = val;
         break;
     case PARA_REG_EPP_ADDR:
         if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT)
             /* Controls not correct for EPP address cycle, so do nothing */
             pdebug("wa%02x s\n", val);
         else {
             struct ParallelIOArg ioarg = { .buffer = &parm, .count = 1 };
             if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE_ADDR, &ioarg)) {
                 s->epp_timeout = 1;
                 pdebug("wa%02x t\n", val);
             }
             else
                 pdebug("wa%02x\n", val);
         }
         break;
     case PARA_REG_EPP_DATA:
         if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT)
             /* Controls not correct for EPP data cycle, so do nothing */
             pdebug("we%02x s\n", val);
         else {
             struct ParallelIOArg ioarg = { .buffer = &parm, .count = 1 };
             if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg)) {
                 s->epp_timeout = 1;
                 pdebug("we%02x t\n", val);
             }
             else
                 pdebug("we%02x\n", val);
         }
         break;
     }
 }

 static void
 parallel_ioport_eppdata_write_hw2(void *opaque, uint32_t addr, uint32_t val)
 {
     ParallelState *s = opaque;
     uint16_t eppdata = cpu_to_le16(val);
     int err;
     struct ParallelIOArg ioarg = {
         .buffer = &eppdata, .count = sizeof(eppdata)
     };
     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT) {
         /* Controls not correct for EPP data cycle, so do nothing */
         pdebug("we%04x s\n", val);
         return;
     }
     err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg);
     if (err) {
         s->epp_timeout = 1;
         pdebug("we%04x t\n", val);
     }
     else
         pdebug("we%04x\n", val);
 }

 static void
 parallel_ioport_eppdata_write_hw4(void *opaque, uint32_t addr, uint32_t val)
 {
     ParallelState *s = opaque;
     uint32_t eppdata = cpu_to_le32(val);
     int err;
     struct ParallelIOArg ioarg = {
         .buffer = &eppdata, .count = sizeof(eppdata)
     };
     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != PARA_CTR_INIT) {
         /* Controls not correct for EPP data cycle, so do nothing */
         pdebug("we%08x s\n", val);
         return;
     }
     err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg);
     if (err) {
         s->epp_timeout = 1;
         pdebug("we%08x t\n", val);
     }
     else
         pdebug("we%08x\n", val);
 }

 static uint32_t parallel_ioport_read_sw(void *opaque, uint32_t addr)
 {
     ParallelState *s = opaque;
     uint32_t ret = 0xff;

     addr &= 7;
     switch(addr) {
     case PARA_REG_DATA:
         if (s->control & PARA_CTR_DIR)
             ret = s->datar;
         else
             ret = s->dataw;
         break;
     case PARA_REG_STS:
         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 PARA_REG_CTR:
         ret = s->control;
         break;
     }
     pdebug("read addr=0x%02x val=0x%02x\n", addr, ret);
     return ret;
 }

 static uint32_t parallel_ioport_read_hw(void *opaque, uint32_t addr)
 {
     ParallelState *s = opaque;
     uint8_t ret = 0xff;
     addr &= 7;
     switch(addr) {
     case PARA_REG_DATA:
         qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_DATA, &ret);
         if (s->last_read_offset != addr || s->datar != ret)
             pdebug("rd%02x\n", ret);
         s->datar = ret;
         break;
     case PARA_REG_STS:
         qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_STATUS, &ret);
         ret &= ~PARA_STS_TMOUT;
         if (s->epp_timeout)
             ret |= PARA_STS_TMOUT;
         if (s->last_read_offset != addr || s->status != ret)
             pdebug("rs%02x\n", ret);
         s->status = ret;
         break;
     case PARA_REG_CTR:
         /* s->control has some bits fixed to 1. It is zero only when
            it has not been yet written to.  */
         if (s->control == 0) {
             qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_CONTROL, &ret);
             if (s->last_read_offset != addr)
                 pdebug("rc%02x\n", ret);
             s->control = ret;
         }
         else {
             ret = s->control;
             if (s->last_read_offset != addr)
                 pdebug("rc%02x\n", ret);
         }
         break;
     case PARA_REG_EPP_ADDR:
         if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR|PARA_CTR_INIT))
             /* Controls not correct for EPP addr cycle, so do nothing */
             pdebug("ra%02x s\n", ret);
         else {
             struct ParallelIOArg ioarg = { .buffer = &ret, .count = 1 };
             if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ_ADDR, &ioarg)) {
                 s->epp_timeout = 1;
                 pdebug("ra%02x t\n", ret);
             }
             else
                 pdebug("ra%02x\n", ret);
         }
         break;
     case PARA_REG_EPP_DATA:
         if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR|PARA_CTR_INIT))
             /* Controls not correct for EPP data cycle, so do nothing */
             pdebug("re%02x s\n", ret);
         else {
             struct ParallelIOArg ioarg = { .buffer = &ret, .count = 1 };
             if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg)) {
                 s->epp_timeout = 1;
                 pdebug("re%02x t\n", ret);
             }
             else
                 pdebug("re%02x\n", ret);
         }
         break;
     }
     s->last_read_offset = addr;
     return ret;
 }

 static uint32_t
 parallel_ioport_eppdata_read_hw2(void *opaque, uint32_t addr)
 {
     ParallelState *s = opaque;
     uint32_t ret;
     uint16_t eppdata = ~0;
     int err;
     struct ParallelIOArg ioarg = {
         .buffer = &eppdata, .count = sizeof(eppdata)
     };
     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR|PARA_CTR_INIT)) {
         /* Controls not correct for EPP data cycle, so do nothing */
         pdebug("re%04x s\n", eppdata);
         return eppdata;
     }
     err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg);
     ret = le16_to_cpu(eppdata);

     if (err) {
         s->epp_timeout = 1;
         pdebug("re%04x t\n", ret);
     }
     else
         pdebug("re%04x\n", ret);
     return ret;
 }

 static uint32_t
 parallel_ioport_eppdata_read_hw4(void *opaque, uint32_t addr)
 {
     ParallelState *s = opaque;
     uint32_t ret;
     uint32_t eppdata = ~0U;
     int err;
     struct ParallelIOArg ioarg = {
         .buffer = &eppdata, .count = sizeof(eppdata)
     };
     if ((s->control & (PARA_CTR_DIR|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR|PARA_CTR_INIT)) {
         /* Controls not correct for EPP data cycle, so do nothing */
         pdebug("re%08x s\n", eppdata);
         return eppdata;
     }
     err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg);
     ret = le32_to_cpu(eppdata);

     if (err) {
         s->epp_timeout = 1;
         pdebug("re%08x t\n", ret);
     }
     else
         pdebug("re%08x\n", ret);
     return ret;
 }

 static void parallel_ioport_ecp_write(void *opaque, uint32_t addr, uint32_t val)
 {
     addr &= 7;
     pdebug("wecp%d=%02x\n", addr, val);
 }

 static uint32_t parallel_ioport_ecp_read(void *opaque, uint32_t addr)
 {
     uint8_t ret = 0xff;
     addr &= 7;
     pdebug("recp%d:%02x\n", addr, ret);
     return ret;
 }

 static void parallel_reset(void *opaque)
 {
     ParallelState *s = opaque;

     s->datar = ~0;
     s->dataw = ~0;
     s->status = PARA_STS_BUSY;
     s->status |= PARA_STS_ACK;
     s->status |= PARA_STS_ONLINE;
     s->status |= PARA_STS_ERROR;
     s->status |= PARA_STS_TMOUT;
     s->control = PARA_CTR_SELECT;
     s->control |= PARA_CTR_INIT;
     s->control |= 0xc0;
     s->irq_pending = 0;
     s->hw_driver = 0;
     s->epp_timeout = 0;
     s->last_read_offset = ~0U;
 }

 /* If fd is zero, it means that the parallel device uses the console */
 ParallelState *parallel_init(int base, qemu_irq irq, CharDriverState *chr)
 {
     ParallelState *s;
     uint8_t dummy;

     s = qemu_mallocz(sizeof(ParallelState));
     s->irq = irq;
     s->chr = chr;
     parallel_reset(s);
     qemu_register_reset(parallel_reset, s);

     if (qemu_chr_ioctl(chr, CHR_IOCTL_PP_READ_STATUS, &dummy) == 0) {
         s->hw_driver = 1;
         s->status = dummy;
     }

     if (s->hw_driver) {
         register_ioport_write(base, 8, 1, parallel_ioport_write_hw, s);
         register_ioport_read(base, 8, 1, parallel_ioport_read_hw, s);
         register_ioport_write(base+4, 1, 2, parallel_ioport_eppdata_write_hw2, s);
         register_ioport_read(base+4, 1, 2, parallel_ioport_eppdata_read_hw2, s);
         register_ioport_write(base+4, 1, 4, parallel_ioport_eppdata_write_hw4, s);
         register_ioport_read(base+4, 1, 4, parallel_ioport_eppdata_read_hw4, s);
         register_ioport_write(base+0x400, 8, 1, parallel_ioport_ecp_write, s);
         register_ioport_read(base+0x400, 8, 1, parallel_ioport_ecp_read, s);
     }
     else {
         register_ioport_write(base, 8, 1, parallel_ioport_write_sw, s);
         register_ioport_read(base, 8, 1, parallel_ioport_read_sw, s);
     }
     return s;
 }

 /* Memory mapped interface */
 static uint32_t parallel_mm_readb (void *opaque, target_phys_addr_t addr)
 {
     ParallelState *s = opaque;

     return parallel_ioport_read_sw(s, addr >> s->it_shift) & 0xFF;
 }

 static void parallel_mm_writeb (void *opaque,
                                 target_phys_addr_t addr, uint32_t value)
 {
     ParallelState *s = opaque;

     parallel_ioport_write_sw(s, addr >> s->it_shift, value & 0xFF);
 }

 static uint32_t parallel_mm_readw (void *opaque, target_phys_addr_t addr)
 {
     ParallelState *s = opaque;

     return parallel_ioport_read_sw(s, addr >> s->it_shift) & 0xFFFF;
 }

 static void parallel_mm_writew (void *opaque,
                                 target_phys_addr_t addr, uint32_t value)
 {
     ParallelState *s = opaque;

     parallel_ioport_write_sw(s, addr >> s->it_shift, value & 0xFFFF);
 }

 static uint32_t parallel_mm_readl (void *opaque, target_phys_addr_t addr)
 {
     ParallelState *s = opaque;

     return parallel_ioport_read_sw(s, addr >> s->it_shift);
 }

 static void parallel_mm_writel (void *opaque,
                                 target_phys_addr_t addr, uint32_t value)
 {
     ParallelState *s = opaque;

     parallel_ioport_write_sw(s, addr >> s->it_shift, value);
 }

 static CPUReadMemoryFunc *parallel_mm_read_sw[] = {
     &parallel_mm_readb,
     &parallel_mm_readw,
     &parallel_mm_readl,
 };

 static CPUWriteMemoryFunc *parallel_mm_write_sw[] = {
     &parallel_mm_writeb,
     &parallel_mm_writew,
     &parallel_mm_writel,
 };

 /* If fd is zero, it means that the parallel device uses the console */
 ParallelState *parallel_mm_init(target_phys_addr_t base, int it_shift, qemu_irq irq, CharDriverState *chr)
 {
     ParallelState *s;
     int io_sw;

     s = qemu_mallocz(sizeof(ParallelState));
     s->irq = irq;
     s->chr = chr;
     s->it_shift = it_shift;
     parallel_reset(s);
     qemu_register_reset(parallel_reset, s);

     io_sw = cpu_register_io_memory(parallel_mm_read_sw, parallel_mm_write_sw, s);
     cpu_register_physical_memory(base, 8 << it_shift, io_sw);
     return s;
 }
	/*
	* QEMU Parallel PORT emulation
	*
	* Copyright (c) 2003-2005 Fabrice Bellard
	* Copyright (c) 2007 Marko Kohtala
	*
	* 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 "hw.h"
	#include "qemu-char.h"
	#include "isa.h"
	#include "pc.h"

	//#define DEBUG_PARALLEL

	#ifdef DEBUG_PARALLEL
	#define pdebug(fmt, ...) printf("pp: " fmt, ## __VA_ARGS__)
	#else
	#define pdebug(fmt, ...) ((void)0)
	#endif

	#define PARA_REG_DATA 0
	#define PARA_REG_STS 1
	#define PARA_REG_CTR 2
	#define PARA_REG_EPP_ADDR 3
	#define PARA_REG_EPP_DATA 4

	/*
	* 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 */
	#define PARA_STS_TMOUT 0x01 /* EPP timeout */

	/*
	* These are the definitions for the Printer Control Register
	*/
	#define PARA_CTR_DIR 0x20 /* Direction (1=read, 0=write) */
	#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 */

	#define PARA_CTR_SIGNAL (PARA_CTR_SELECT\|PARA_CTR_INIT\|PARA_CTR_AUTOLF\|PARA_CTR_STROBE)

	struct ParallelState {
	uint8_t dataw;
	uint8_t datar;
	uint8_t status;
	uint8_t control;
	qemu_irq irq;
	int irq_pending;
	CharDriverState *chr;
	int hw_driver;
	int epp_timeout;
	uint32_t last_read_offset; /* For debugging */
	/* Memory-mapped interface */
	int it_shift;
	};

	static void parallel_update_irq(ParallelState *s)
	{
	if (s->irq_pending)
	qemu_irq_raise(s->irq);
	else
	qemu_irq_lower(s->irq);
	}

	static void
	parallel_ioport_write_sw(void *opaque, uint32_t addr, uint32_t val)
	{
	ParallelState *s = opaque;

	pdebug("write addr=0x%02x val=0x%02x\n", addr, val);

	addr &= 7;
	switch(addr) {
	case PARA_REG_DATA:
	s->dataw = val;
	parallel_update_irq(s);
	break;
	case PARA_REG_CTR:
	val \|= 0xc0;
	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->dataw, 1);
	} else {
	if (s->control & PARA_CTR_INTEN) {
	s->irq_pending = 1;
	}
	}
	}
	parallel_update_irq(s);
	s->control = val;
	break;
	}
	}

	static void parallel_ioport_write_hw(void *opaque, uint32_t addr, uint32_t val)
	{
	ParallelState *s = opaque;
	uint8_t parm = val;
	int dir;

	/* Sometimes programs do several writes for timing purposes on old
	HW. Take care not to waste time on writes that do nothing. */

	s->last_read_offset = ~0U;

	addr &= 7;
	switch(addr) {
	case PARA_REG_DATA:
	if (s->dataw == val)
	return;
	pdebug("wd%02x\n", val);
	qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_WRITE_DATA, &parm);
	s->dataw = val;
	break;
	case PARA_REG_STS:
	pdebug("ws%02x\n", val);
	if (val & PARA_STS_TMOUT)
	s->epp_timeout = 0;
	break;
	case PARA_REG_CTR:
	val \|= 0xc0;
	if (s->control == val)
	return;
	pdebug("wc%02x\n", val);

	if ((val & PARA_CTR_DIR) != (s->control & PARA_CTR_DIR)) {
	if (val & PARA_CTR_DIR) {
	dir = 1;
	} else {
	dir = 0;
	}
	qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_DATA_DIR, &dir);
	parm &= ~PARA_CTR_DIR;
	}

	qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_WRITE_CONTROL, &parm);
	s->control = val;
	break;
	case PARA_REG_EPP_ADDR:
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != PARA_CTR_INIT)
	/* Controls not correct for EPP address cycle, so do nothing */
	pdebug("wa%02x s\n", val);
	else {
	struct ParallelIOArg ioarg = { .buffer = &parm, .count = 1 };
	if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE_ADDR, &ioarg)) {
	s->epp_timeout = 1;
	pdebug("wa%02x t\n", val);
	}
	else
	pdebug("wa%02x\n", val);
	}
	break;
	case PARA_REG_EPP_DATA:
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != PARA_CTR_INIT)
	/* Controls not correct for EPP data cycle, so do nothing */
	pdebug("we%02x s\n", val);
	else {
	struct ParallelIOArg ioarg = { .buffer = &parm, .count = 1 };
	if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg)) {
	s->epp_timeout = 1;
	pdebug("we%02x t\n", val);
	}
	else
	pdebug("we%02x\n", val);
	}
	break;
	}
	}

	static void
	parallel_ioport_eppdata_write_hw2(void *opaque, uint32_t addr, uint32_t val)
	{
	ParallelState *s = opaque;
	uint16_t eppdata = cpu_to_le16(val);
	int err;
	struct ParallelIOArg ioarg = {
	.buffer = &eppdata, .count = sizeof(eppdata)
	};
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != PARA_CTR_INIT) {
	/* Controls not correct for EPP data cycle, so do nothing */
	pdebug("we%04x s\n", val);
	return;
	}
	err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg);
	if (err) {
	s->epp_timeout = 1;
	pdebug("we%04x t\n", val);
	}
	else
	pdebug("we%04x\n", val);
	}

	static void
	parallel_ioport_eppdata_write_hw4(void *opaque, uint32_t addr, uint32_t val)
	{
	ParallelState *s = opaque;
	uint32_t eppdata = cpu_to_le32(val);
	int err;
	struct ParallelIOArg ioarg = {
	.buffer = &eppdata, .count = sizeof(eppdata)
	};
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != PARA_CTR_INIT) {
	/* Controls not correct for EPP data cycle, so do nothing */
	pdebug("we%08x s\n", val);
	return;
	}
	err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_WRITE, &ioarg);
	if (err) {
	s->epp_timeout = 1;
	pdebug("we%08x t\n", val);
	}
	else
	pdebug("we%08x\n", val);
	}

	static uint32_t parallel_ioport_read_sw(void *opaque, uint32_t addr)
	{
	ParallelState *s = opaque;
	uint32_t ret = 0xff;

	addr &= 7;
	switch(addr) {
	case PARA_REG_DATA:
	if (s->control & PARA_CTR_DIR)
	ret = s->datar;
	else
	ret = s->dataw;
	break;
	case PARA_REG_STS:
	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 PARA_REG_CTR:
	ret = s->control;
	break;
	}
	pdebug("read addr=0x%02x val=0x%02x\n", addr, ret);
	return ret;
	}

	static uint32_t parallel_ioport_read_hw(void *opaque, uint32_t addr)
	{
	ParallelState *s = opaque;
	uint8_t ret = 0xff;
	addr &= 7;
	switch(addr) {
	case PARA_REG_DATA:
	qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_DATA, &ret);
	if (s->last_read_offset != addr \|\| s->datar != ret)
	pdebug("rd%02x\n", ret);
	s->datar = ret;
	break;
	case PARA_REG_STS:
	qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_STATUS, &ret);
	ret &= ~PARA_STS_TMOUT;
	if (s->epp_timeout)
	ret \|= PARA_STS_TMOUT;
	if (s->last_read_offset != addr \|\| s->status != ret)
	pdebug("rs%02x\n", ret);
	s->status = ret;
	break;
	case PARA_REG_CTR:
	/* s->control has some bits fixed to 1. It is zero only when
	it has not been yet written to. */
	if (s->control == 0) {
	qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_READ_CONTROL, &ret);
	if (s->last_read_offset != addr)
	pdebug("rc%02x\n", ret);
	s->control = ret;
	}
	else {
	ret = s->control;
	if (s->last_read_offset != addr)
	pdebug("rc%02x\n", ret);
	}
	break;
	case PARA_REG_EPP_ADDR:
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR\|PARA_CTR_INIT))
	/* Controls not correct for EPP addr cycle, so do nothing */
	pdebug("ra%02x s\n", ret);
	else {
	struct ParallelIOArg ioarg = { .buffer = &ret, .count = 1 };
	if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ_ADDR, &ioarg)) {
	s->epp_timeout = 1;
	pdebug("ra%02x t\n", ret);
	}
	else
	pdebug("ra%02x\n", ret);
	}
	break;
	case PARA_REG_EPP_DATA:
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR\|PARA_CTR_INIT))
	/* Controls not correct for EPP data cycle, so do nothing */
	pdebug("re%02x s\n", ret);
	else {
	struct ParallelIOArg ioarg = { .buffer = &ret, .count = 1 };
	if (qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg)) {
	s->epp_timeout = 1;
	pdebug("re%02x t\n", ret);
	}
	else
	pdebug("re%02x\n", ret);
	}
	break;
	}
	s->last_read_offset = addr;
	return ret;
	}

	static uint32_t
	parallel_ioport_eppdata_read_hw2(void *opaque, uint32_t addr)
	{
	ParallelState *s = opaque;
	uint32_t ret;
	uint16_t eppdata = ~0;
	int err;
	struct ParallelIOArg ioarg = {
	.buffer = &eppdata, .count = sizeof(eppdata)
	};
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR\|PARA_CTR_INIT)) {
	/* Controls not correct for EPP data cycle, so do nothing */
	pdebug("re%04x s\n", eppdata);
	return eppdata;
	}
	err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg);
	ret = le16_to_cpu(eppdata);

	if (err) {
	s->epp_timeout = 1;
	pdebug("re%04x t\n", ret);
	}
	else
	pdebug("re%04x\n", ret);
	return ret;
	}

	static uint32_t
	parallel_ioport_eppdata_read_hw4(void *opaque, uint32_t addr)
	{
	ParallelState *s = opaque;
	uint32_t ret;
	uint32_t eppdata = ~0U;
	int err;
	struct ParallelIOArg ioarg = {
	.buffer = &eppdata, .count = sizeof(eppdata)
	};
	if ((s->control & (PARA_CTR_DIR\|PARA_CTR_SIGNAL)) != (PARA_CTR_DIR\|PARA_CTR_INIT)) {
	/* Controls not correct for EPP data cycle, so do nothing */
	pdebug("re%08x s\n", eppdata);
	return eppdata;
	}
	err = qemu_chr_ioctl(s->chr, CHR_IOCTL_PP_EPP_READ, &ioarg);
	ret = le32_to_cpu(eppdata);

	if (err) {
	s->epp_timeout = 1;
	pdebug("re%08x t\n", ret);
	}
	else
	pdebug("re%08x\n", ret);
	return ret;
	}

	static void parallel_ioport_ecp_write(void *opaque, uint32_t addr, uint32_t val)
	{
	addr &= 7;
	pdebug("wecp%d=%02x\n", addr, val);
	}

	static uint32_t parallel_ioport_ecp_read(void *opaque, uint32_t addr)
	{
	uint8_t ret = 0xff;
	addr &= 7;
	pdebug("recp%d:%02x\n", addr, ret);
	return ret;
	}

	static void parallel_reset(void *opaque)
	{
	ParallelState *s = opaque;

	s->datar = ~0;
	s->dataw = ~0;
	s->status = PARA_STS_BUSY;
	s->status \|= PARA_STS_ACK;
	s->status \|= PARA_STS_ONLINE;
	s->status \|= PARA_STS_ERROR;
	s->status \|= PARA_STS_TMOUT;
	s->control = PARA_CTR_SELECT;
	s->control \|= PARA_CTR_INIT;
	s->control \|= 0xc0;
	s->irq_pending = 0;
	s->hw_driver = 0;
	s->epp_timeout = 0;
	s->last_read_offset = ~0U;
	}

	/* If fd is zero, it means that the parallel device uses the console */
	ParallelState parallel_init(int base, qemu_irq irq, CharDriverState chr)
	{
	ParallelState *s;
	uint8_t dummy;

	s = qemu_mallocz(sizeof(ParallelState));
	s->irq = irq;
	s->chr = chr;
	parallel_reset(s);
	qemu_register_reset(parallel_reset, s);

	if (qemu_chr_ioctl(chr, CHR_IOCTL_PP_READ_STATUS, &dummy) == 0) {
	s->hw_driver = 1;
	s->status = dummy;
	}

	if (s->hw_driver) {
	register_ioport_write(base, 8, 1, parallel_ioport_write_hw, s);
	register_ioport_read(base, 8, 1, parallel_ioport_read_hw, s);
	register_ioport_write(base+4, 1, 2, parallel_ioport_eppdata_write_hw2, s);
	register_ioport_read(base+4, 1, 2, parallel_ioport_eppdata_read_hw2, s);
	register_ioport_write(base+4, 1, 4, parallel_ioport_eppdata_write_hw4, s);
	register_ioport_read(base+4, 1, 4, parallel_ioport_eppdata_read_hw4, s);
	register_ioport_write(base+0x400, 8, 1, parallel_ioport_ecp_write, s);
	register_ioport_read(base+0x400, 8, 1, parallel_ioport_ecp_read, s);
	}
	else {
	register_ioport_write(base, 8, 1, parallel_ioport_write_sw, s);
	register_ioport_read(base, 8, 1, parallel_ioport_read_sw, s);
	}
	return s;
	}

	/* Memory mapped interface */
	static uint32_t parallel_mm_readb (void *opaque, target_phys_addr_t addr)
	{
	ParallelState *s = opaque;

	return parallel_ioport_read_sw(s, addr >> s->it_shift) & 0xFF;
	}

	static void parallel_mm_writeb (void *opaque,
	target_phys_addr_t addr, uint32_t value)
	{
	ParallelState *s = opaque;

	parallel_ioport_write_sw(s, addr >> s->it_shift, value & 0xFF);
	}

	static uint32_t parallel_mm_readw (void *opaque, target_phys_addr_t addr)
	{
	ParallelState *s = opaque;

	return parallel_ioport_read_sw(s, addr >> s->it_shift) & 0xFFFF;
	}

	static void parallel_mm_writew (void *opaque,
	target_phys_addr_t addr, uint32_t value)
	{
	ParallelState *s = opaque;

	parallel_ioport_write_sw(s, addr >> s->it_shift, value & 0xFFFF);
	}

	static uint32_t parallel_mm_readl (void *opaque, target_phys_addr_t addr)
	{
	ParallelState *s = opaque;

	return parallel_ioport_read_sw(s, addr >> s->it_shift);
	}

	static void parallel_mm_writel (void *opaque,
	target_phys_addr_t addr, uint32_t value)
	{
	ParallelState *s = opaque;

	parallel_ioport_write_sw(s, addr >> s->it_shift, value);
	}

	static CPUReadMemoryFunc *parallel_mm_read_sw[] = {
	&parallel_mm_readb,
	&parallel_mm_readw,
	&parallel_mm_readl,
	};

	static CPUWriteMemoryFunc *parallel_mm_write_sw[] = {
	&parallel_mm_writeb,
	&parallel_mm_writew,
	&parallel_mm_writel,
	};

	/* If fd is zero, it means that the parallel device uses the console */
	ParallelState parallel_mm_init(target_phys_addr_t base, int it_shift, qemu_irq irq, CharDriverState chr)
	{
	ParallelState *s;
	int io_sw;

	s = qemu_mallocz(sizeof(ParallelState));
	s->irq = irq;
	s->chr = chr;
	s->it_shift = it_shift;
	parallel_reset(s);
	qemu_register_reset(parallel_reset, s);

	io_sw = cpu_register_io_memory(parallel_mm_read_sw, parallel_mm_write_sw, s);
	cpu_register_physical_memory(base, 8 << it_shift, io_sw);
	return s;
	}