hw/parallel.c

/*
 * 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, a_target_phys_addr addr)
{
    ParallelState *s = opaque;

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

static void parallel_mm_writeb (void *opaque,
                                a_target_phys_addr 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, a_target_phys_addr addr)
{
    ParallelState *s = opaque;

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

static void parallel_mm_writew (void *opaque,
                                a_target_phys_addr 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, a_target_phys_addr addr)
{
    ParallelState *s = opaque;

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

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

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

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

static CPUWriteMemoryFunc * const 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(a_target_phys_addr 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;
}