* added 0.99 linux version

[mascara-docs.git] / i386 / linux / linux-2.3.21 / drivers / parport / parport_pc.c

/* Low-level parallel-port routines for 8255-based PC-style hardware.
 * 
 * Authors: Phil Blundell <Philip.Blundell@pobox.com>
 *          Tim Waugh <tim@cyberelk.demon.co.uk>
 *          Jose Renau <renau@acm.org>
 *          David Campbell <campbell@torque.net>
 *          Andrea Arcangeli
 *
 * based on work by Grant Guenther <grant@torque.net> and Phil Blundell.
 *
 * Cleaned up include files - Russell King <linux@arm.uk.linux.org>
 * DMA support - Bert De Jonghe <bert@sophis.be>
 * Many ECP bugs fixed.  Fred Barnes & Jamie Lokier, 1999
 */

/* This driver should work with any hardware that is broadly compatible
 * with that in the IBM PC.  This applies to the majority of integrated
 * I/O chipsets that are commonly available.  The expected register
 * layout is:
 *
 *      base+0          data
 *      base+1          status
 *      base+2          control
 *
 * In addition, there are some optional registers:
 *
 *      base+3          EPP address
 *      base+4          EPP data
 *      base+0x400      ECP config A
 *      base+0x401      ECP config B
 *      base+0x402      ECP control
 *
 * All registers are 8 bits wide and read/write.  If your hardware differs
 * only in register addresses (eg because your registers are on 32-bit
 * word boundaries) then you can alter the constants in parport_pc.h to
 * accomodate this.
 *
 * Note that the ECP registers may not start at offset 0x400 for PCI cards,
 * but rather will start at port->base_hi.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/malloc.h>
#include <linux/pci.h>
#include <linux/sysctl.h>

#include <asm/io.h>
#include <asm/dma.h>
#include <asm/uaccess.h>

#include <linux/parport.h>
#include <linux/parport_pc.h>
#include <asm/parport.h>

/* ECR modes */
#define ECR_SPP 00
#define ECR_PS2 01
#define ECR_PPF 02
#define ECR_ECP 03
#define ECR_EPP 04
#define ECR_VND 05
#define ECR_TST 06
#define ECR_CNF 07

/* frob_control, but for ECR */
static void frob_econtrol (struct parport *pb, unsigned char m,
                           unsigned char v)
{
        unsigned char ectr = inb (ECONTROL (pb));
#ifdef DEBUG_PARPORT
        printk (KERN_DEBUG "frob_econtrol(%02x,%02x): %02x -> %02x\n",
                m, v, ectr, (ectr & ~m) ^ v);
#endif
        outb ((ectr & ~m) ^ v, ECONTROL (pb));
}

#ifdef CONFIG_PARPORT_PC_FIFO
/* Safely change the mode bits in the ECR */
static int change_mode(struct parport *p, int m)
{
        const struct parport_pc_private *priv = p->physport->private_data;
        int ecr = ECONTROL(p);
        unsigned char oecr;
        int mode;

        if (!priv->ecr) {
                printk (KERN_DEBUG "change_mode: but there's no ECR!\n");
                return 0;
        }

        /* Bits <7:5> contain the mode. */
        oecr = inb (ecr);
        mode = (oecr >> 5) & 0x7;
        if (mode == m) return 0;

        if (mode >= 2 && !(priv->ctr & 0x20)) {
                /* This mode resets the FIFO, so we may
                 * have to wait for it to drain first. */
                long expire = jiffies + p->physport->cad->timeout;
                int counter;
                switch (mode) {
                case ECR_PPF: /* Parallel Port FIFO mode */
                case ECR_ECP: /* ECP Parallel Port mode */
                        /* Busy wait for 200us */
                        for (counter = 0; counter < 40; counter++) {
                                if (inb (ECONTROL (p)) & 0x01)
                                        break;
                                if (signal_pending (current)) break;
                                udelay (5);
                        }

                        /* Poll slowly. */
                        while (!(inb (ECONTROL (p)) & 0x01)) {
                                if (time_after_eq (jiffies, expire))
                                        /* The FIFO is stuck. */
                                        return -EBUSY;
                                current->state = TASK_INTERRUPTIBLE;
                                schedule_timeout ((HZ + 99) / 100);
                                if (signal_pending (current))
                                        break;
                        }
                }
        }

        if (mode >= 2 && m >= 2) {
                /* We have to go through mode 001 */
                oecr &= ~(7 << 5);
                oecr |= ECR_PS2 << 5;
                outb (oecr, ecr);
        }

        /* Set the mode. */
        oecr &= ~(7 << 5);
        oecr |= m << 5;
        outb (oecr, ecr);
        return 0;
}

#ifdef CONFIG_PARPORT_1284
/* Find FIFO lossage; FIFO is reset */
static int get_fifo_residue (struct parport *p)
{
        int residue;
        int cnfga;
        const struct parport_pc_private *priv = p->physport->private_data;

        /* Prevent further data transfer. */
        parport_frob_control (p,
                              PARPORT_CONTROL_STROBE,
                              PARPORT_CONTROL_STROBE);

        /* Adjust for the contents of the FIFO. */
        for (residue = priv->fifo_depth; ; residue--) {
                if (inb (ECONTROL (p)) & 0x2)
                                /* Full up. */
                        break;

                outb (0, FIFO (p));
        }

        printk (KERN_DEBUG "%s: %d PWords were left in FIFO\n", p->name,
                residue);

        /* Reset the FIFO. */
        frob_econtrol (p, 0xe0, ECR_PS2 << 5);
        parport_frob_control (p, PARPORT_CONTROL_STROBE, 0);

        /* Now change to config mode and clean up. FIXME */
        frob_econtrol (p, 0xe0, ECR_CNF << 5);
        cnfga = inb (CONFIGA (p));
        printk (KERN_DEBUG "%s: cnfgA contains 0x%02x\n", p->name, cnfga);

        if (!(cnfga & (1<<2))) {
                printk (KERN_DEBUG "%s: Accounting for extra byte\n", p->name);
                residue++;
        }

        /* Don't care about partial PWords until support is added for
         * PWord != 1 byte. */

        /* Back to PS2 mode. */
        frob_econtrol (p, 0xe0, ECR_PS2 << 5);

        return residue;
}
#endif /* IEEE 1284 support */
#endif /* FIFO support */

/*
 * Clear TIMEOUT BIT in EPP MODE
 *
 * This is also used in SPP detection.
 */
static int clear_epp_timeout(struct parport *pb)
{
        unsigned char r;

        if (!(parport_pc_read_status(pb) & 0x01))
                return 1;

        /* To clear timeout some chips require double read */
        parport_pc_read_status(pb);
        r = parport_pc_read_status(pb);
        outb (r | 0x01, STATUS (pb)); /* Some reset by writing 1 */
        outb (r & 0xfe, STATUS (pb)); /* Others by writing 0 */
        r = parport_pc_read_status(pb);

        return !(r & 0x01);
}

/*
 * Access functions.
 *
 * Most of these aren't static because they may be used by the
 * parport_xxx_yyy macros.  extern __inline__ versions of several
 * of these are in parport_pc.h.
 */

static void parport_pc_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
        parport_generic_irq(irq, (struct parport *) dev_id, regs);
}

void parport_pc_write_data(struct parport *p, unsigned char d)
{
        outb (d, DATA (p));
}

unsigned char parport_pc_read_data(struct parport *p)
{
        return inb (DATA (p));
}

void parport_pc_write_control(struct parport *p, unsigned char d)
{
        const unsigned char wm = (PARPORT_CONTROL_STROBE |
                                  PARPORT_CONTROL_AUTOFD |
                                  PARPORT_CONTROL_INIT |
                                  PARPORT_CONTROL_SELECT);

        /* Take this out when drivers have adapted to the newer interface. */
        if (d & 0x20) {
                printk (KERN_DEBUG "%s (%s): use data_reverse for this!\n",
                        p->name, p->cad->name);
                parport_pc_data_reverse (p);
        }

        __parport_pc_frob_control (p, wm, d & wm);
}

unsigned char parport_pc_read_control(struct parport *p)
{
        const unsigned char wm = (PARPORT_CONTROL_STROBE |
                                  PARPORT_CONTROL_AUTOFD |
                                  PARPORT_CONTROL_INIT |
                                  PARPORT_CONTROL_SELECT);
        const struct parport_pc_private *priv = p->physport->private_data;
        return priv->ctr & wm; /* Use soft copy */
}

unsigned char parport_pc_frob_control (struct parport *p, unsigned char mask,
                                       unsigned char val)
{
        const unsigned char wm = (PARPORT_CONTROL_STROBE |
                                  PARPORT_CONTROL_AUTOFD |
                                  PARPORT_CONTROL_INIT |
                                  PARPORT_CONTROL_SELECT);

        /* Take this out when drivers have adapted to the newer interface. */
        if (mask & 0x20) {
                printk (KERN_DEBUG "%s (%s): use data_%s for this!\n",
                        p->name, p->cad->name,
                        (val & 0x20) ? "reverse" : "forward");
                if (val & 0x20)
                        parport_pc_data_reverse (p);
                else
                        parport_pc_data_forward (p);
        }

        /* Restrict mask and val to control lines. */
        mask &= wm;
        val &= wm;

        return __parport_pc_frob_control (p, mask, val);
}

unsigned char parport_pc_read_status(struct parport *p)
{
        return inb (STATUS (p));
}

void parport_pc_disable_irq(struct parport *p)
{
        __parport_pc_frob_control (p, 0x10, 0);
}

void parport_pc_enable_irq(struct parport *p)
{
        __parport_pc_frob_control (p, 0x10, 0x10);
}

void parport_pc_data_forward (struct parport *p)
{
        __parport_pc_frob_control (p, 0x20, 0);
}

void parport_pc_data_reverse (struct parport *p)
{
        __parport_pc_frob_control (p, 0x20, 0x20);
}

void parport_pc_init_state(struct pardevice *dev, struct parport_state *s)
{
        s->u.pc.ctr = 0xc | (dev->irq_func ? 0x10 : 0x0);
        s->u.pc.ecr = 0x24;
}

void parport_pc_save_state(struct parport *p, struct parport_state *s)
{
        const struct parport_pc_private *priv = p->physport->private_data;
        s->u.pc.ctr = inb (CONTROL (p));
        if (priv->ecr)
                s->u.pc.ecr = inb (ECONTROL (p));
}

void parport_pc_restore_state(struct parport *p, struct parport_state *s)
{
        const struct parport_pc_private *priv = p->physport->private_data;
        outb (s->u.pc.ctr, CONTROL (p));
        if (priv->ecr)
                outb (s->u.pc.ecr, ECONTROL (p));
}

#ifdef CONFIG_PARPORT_1284
static size_t parport_pc_epp_read_data (struct parport *port, void *buf,
                                        size_t length, int flags)
{
        size_t got = 0;
        for (; got < length; got++) {
                *((char*)buf)++ = inb (EPPDATA(port));
                if (inb (STATUS(port)) & 0x01) {
                        clear_epp_timeout (port);
                        break;
                }
        }

        return got;
}

static size_t parport_pc_epp_write_data (struct parport *port, const void *buf,
                                         size_t length, int flags)
{
        size_t written = 0;
        for (; written < length; written++) {
                outb (*((char*)buf)++, EPPDATA(port));
                if (inb (STATUS(port)) & 0x01) {
                        clear_epp_timeout (port);
                        break;
                }
        }

        return written;
}

static size_t parport_pc_epp_read_addr (struct parport *port, void *buf,
                                        size_t length, int flags)
{
        size_t got = 0;
        for (; got < length; got++) {
                *((char*)buf)++ = inb (EPPADDR (port));
                if (inb (STATUS (port)) & 0x01) {
                        clear_epp_timeout (port);
                        break;
                }
        }

        return got;
}

static size_t parport_pc_epp_write_addr (struct parport *port,
                                         const void *buf, size_t length,
                                         int flags)
{
        size_t written = 0;
        for (; written < length; written++) {
                outb (*((char*)buf)++, EPPADDR (port));
                if (inb (STATUS (port)) & 0x01) {
                        clear_epp_timeout (port);
                        break;
                }
        }

        return written;
}

static size_t parport_pc_ecpepp_read_data (struct parport *port, void *buf,
                                           size_t length, int flags)
{
        size_t got;

        frob_econtrol (port, 0xe0, ECR_EPP << 5);
        got = parport_pc_epp_read_data (port, buf, length, flags);
        frob_econtrol (port, 0xe0, ECR_PS2 << 5);

        return got;
}

static size_t parport_pc_ecpepp_write_data (struct parport *port,
                                            const void *buf, size_t length,
                                            int flags)
{
        size_t written;

        frob_econtrol (port, 0xe0, ECR_EPP << 5);
        written = parport_pc_epp_write_data (port, buf, length, flags);
        frob_econtrol (port, 0xe0, ECR_PS2 << 5);

        return written;
}

static size_t parport_pc_ecpepp_read_addr (struct parport *port, void *buf,
                                           size_t length, int flags)
{
        size_t got;

        frob_econtrol (port, 0xe0, ECR_EPP << 5);
        got = parport_pc_epp_read_addr (port, buf, length, flags);
        frob_econtrol (port, 0xe0, ECR_PS2 << 5);

        return got;
}

static size_t parport_pc_ecpepp_write_addr (struct parport *port,
                                            const void *buf, size_t length,
                                            int flags)
{
        size_t written;

        frob_econtrol (port, 0xe0, ECR_EPP << 5);
        written = parport_pc_epp_write_addr (port, buf, length, flags);
        frob_econtrol (port, 0xe0, ECR_PS2 << 5);

        return written;
}
#endif /* IEEE 1284 support */

#ifdef CONFIG_PARPORT_PC_FIFO
static size_t parport_pc_fifo_write_block_pio (struct parport *port,
                                               const void *buf, size_t length)
{
        int ret = 0;
        const unsigned char *bufp = buf;
        size_t left = length;
        long expire = jiffies + port->physport->cad->timeout;
        const int fifo = FIFO (port);
        int poll_for = 8; /* 80 usecs */
        const struct parport_pc_private *priv = port->physport->private_data;
        const int fifo_depth = priv->fifo_depth;

        port = port->physport;

        /* We don't want to be interrupted every character. */
        parport_pc_disable_irq (port);
        frob_econtrol (port, (1<<4), (1<<4)); /* nErrIntrEn */

        /* Forward mode. */
        parport_pc_data_forward (port); /* Must be in PS2 mode */

        while (left) {
                unsigned char byte;
                unsigned char ecrval = inb (ECONTROL (port));
                int i = 0;

                if (current->need_resched && time_before (jiffies, expire))
                        /* Can't yield the port. */
                        schedule ();

                /* Anyone else waiting for the port? */
                if (port->waithead) {
                        printk (KERN_DEBUG "Somebody wants the port\n");
                        break;
                }

                if (ecrval & 0x02) {
                        /* FIFO is full. Wait for interrupt. */

                        /* Clear serviceIntr */
                        outb (ecrval & ~(1<<2), ECONTROL (port));
                false_alarm:
                        ret = parport_wait_event (port, HZ);
                        if (ret < 0) break;
                        ret = 0;
                        if (!time_before (jiffies, expire)) {
                                /* Timed out. */
                                printk (KERN_DEBUG "Timed out\n");
                                break;
                        }
                        ecrval = inb (ECONTROL (port));
                        if (!(ecrval & (1<<2))) {
                                if (current->need_resched &&
                                    time_before (jiffies, expire))
                                        schedule ();

                                goto false_alarm;
                        }

                        continue;
                }

                /* Can't fail now. */
                expire = jiffies + port->cad->timeout;

        poll:
                if (signal_pending (current))
                        break;

                if (ecrval & 0x01) {
                        /* FIFO is empty. Blast it full. */
                        const int n = left < fifo_depth ? left : fifo_depth;
                        outsb (fifo, bufp, n);
                        bufp += n;
                        left -= n;

                        /* Adjust the poll time. */
                        if (i < (poll_for - 2)) poll_for--;
                        continue;
                } else if (i++ < poll_for) {
                        udelay (10);
                        ecrval = inb (ECONTROL (port));
                        goto poll;
                }

                /* Half-full (call me an optimist) */
                byte = *bufp++;
                outb (byte, fifo);
                left--;
        }

        return length - left;
}

static size_t parport_pc_fifo_write_block_dma (struct parport *port,
                                               const void *buf, size_t length)
{
        int ret = 0;
        unsigned long dmaflag;
        size_t left  = length;
        const struct parport_pc_private *priv = port->physport->private_data;

        port = port->physport;

        /* We don't want to be interrupted every character. */
        parport_pc_disable_irq (port);
        frob_econtrol (port, (1<<4), (1<<4)); /* nErrIntrEn */

        /* Forward mode. */
        parport_pc_data_forward (port); /* Must be in PS2 mode */

        while (left) {
                long expire = jiffies + port->physport->cad->timeout;

                size_t count = left;

                if (count > PAGE_SIZE)
                        count = PAGE_SIZE;

                memcpy(priv->dma_buf, buf, count);

                dmaflag = claim_dma_lock();
                disable_dma(port->dma);
                clear_dma_ff(port->dma);
                set_dma_mode(port->dma, DMA_MODE_WRITE);
                set_dma_addr(port->dma, virt_to_bus((volatile char *) priv->dma_buf));
                set_dma_count(port->dma, count);

                /* Set DMA mode */
                frob_econtrol (port, 1<<3, 1<<3);

                /* Clear serviceIntr */
                frob_econtrol (port, 1<<2, 0);

                enable_dma(port->dma);
                release_dma_lock(dmaflag);

                /* assume DMA will be successful */
                left -= count;
                buf  += count;

                /* Wait for interrupt. */
        false_alarm:
                ret = parport_wait_event (port, HZ);
                if (ret < 0) break;
                ret = 0;
                if (!time_before (jiffies, expire)) {
                        /* Timed out. */
                        printk (KERN_DEBUG "Timed out\n");
                        break;
                }
                /* Is serviceIntr set? */
                if (!(inb (ECONTROL (port)) & (1<<2))) {
                        if (current->need_resched)
                                schedule ();

                        goto false_alarm;
                }

                dmaflag = claim_dma_lock();
                disable_dma(port->dma);
                clear_dma_ff(port->dma);
                count = get_dma_residue(port->dma);
                release_dma_lock(dmaflag);

                if (current->need_resched)
                        /* Can't yield the port. */
                        schedule ();

                /* Anyone else waiting for the port? */
                if (port->waithead) {
                        printk (KERN_DEBUG "Somebody wants the port\n");
                        break;
                }

                /* update for possible DMA residue ! */
                buf  -= count;
                left += count;
        }

        /* Maybe got here through break, so adjust for DMA residue! */
        dmaflag = claim_dma_lock();
        disable_dma(port->dma);
        clear_dma_ff(port->dma);
        left += get_dma_residue(port->dma);
        release_dma_lock(dmaflag);

        /* Turn off DMA mode */
        frob_econtrol (port, 1<<3, 0);

        return length - left;
}

/* Parallel Port FIFO mode (ECP chipsets) */
size_t parport_pc_compat_write_block_pio (struct parport *port,
                                          const void *buf, size_t length,
                                          int flags)
{
        size_t written;

        /* Special case: a timeout of zero means we cannot call schedule(). */
        if (!port->physport->cad->timeout)
                return parport_ieee1284_write_compat (port, buf,
                                                      length, flags);

        /* Set up parallel port FIFO mode.*/
        parport_pc_data_forward (port); /* Must be in PS2 mode */
        change_mode (port, ECR_PPF); /* Parallel port FIFO */
        port->physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;

        /* Write the data to the FIFO. */
        if (port->dma != PARPORT_DMA_NONE)
                written = parport_pc_fifo_write_block_dma (port, buf, length);
        else
                written = parport_pc_fifo_write_block_pio (port, buf, length);

        /* Finish up. */
        if (change_mode (port, ECR_PS2) == -EBUSY) {
                const struct parport_pc_private *priv = 
                        port->physport->private_data;

                printk (KERN_DEBUG "%s: FIFO is stuck\n", port->name);

                /* Prevent further data transfer. */
                parport_frob_control (port,
                                      PARPORT_CONTROL_STROBE,
                                      PARPORT_CONTROL_STROBE);

                /* Adjust for the contents of the FIFO. */
                for (written -= priv->fifo_depth; ; written++) {
                        if (inb (ECONTROL (port)) & 0x2)
                                /* Full up. */
                                break;

                        outb (0, FIFO (port));
                }

                /* Reset the FIFO and return to PS2 mode. */
                frob_econtrol (port, 0xe0, ECR_PS2 << 5);

                /* De-assert strobe. */
                parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);
        }

        parport_wait_peripheral (port,
                                 PARPORT_STATUS_BUSY,
                                 PARPORT_STATUS_BUSY);
        port->physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;

        return written;
}

/* ECP */
#ifdef CONFIG_PARPORT_1284
size_t parport_pc_ecp_write_block_pio (struct parport *port,
                                       const void *buf, size_t length,
                                       int flags)
{
        size_t written;

        /* Special case: a timeout of zero means we cannot call schedule(). */
        if (!port->physport->cad->timeout)
                return parport_ieee1284_ecp_write_data (port, buf,
                                                        length, flags);

        /* Switch to forward mode if necessary. */
        if (port->physport->ieee1284.phase != IEEE1284_PH_FWD_IDLE) {
                /* Event 47: Set nInit high. */
                parport_frob_control (port, PARPORT_CONTROL_INIT, 0);

                /* Event 40: PError goes high. */
                parport_wait_peripheral (port,
                                         PARPORT_STATUS_PAPEROUT,
                                         PARPORT_STATUS_PAPEROUT);
        }

        /* Set up ECP parallel port mode.*/
        parport_pc_data_forward (port); /* Must be in PS2 mode */
        change_mode (port, ECR_ECP); /* ECP FIFO */
        port->physport->ieee1284.phase = IEEE1284_PH_FWD_DATA;

        /* Write the data to the FIFO. */
        if (port->dma != PARPORT_DMA_NONE)
                written = parport_pc_fifo_write_block_dma (port, buf, length);
        else
                written = parport_pc_fifo_write_block_pio (port, buf, length);

        /* Finish up. */
        if (change_mode (port, ECR_PS2) == -EBUSY) {
                const struct parport_pc_private *priv =
                        port->physport->private_data;

                printk (KERN_DEBUG "%s: FIFO is stuck\n", port->name);

                /* Prevent further data transfer. */
                parport_frob_control (port,
                                      PARPORT_CONTROL_STROBE,
                                      PARPORT_CONTROL_STROBE);

                /* Adjust for the contents of the FIFO. */
                for (written -= priv->fifo_depth; ; written++) {
                        if (inb (ECONTROL (port)) & 0x2)
                                /* Full up. */
                                break;

                        outb (0, FIFO (port));
                }

                /* Reset the FIFO and return to PS2 mode. */
                frob_econtrol (port, 0xe0, ECR_PS2 << 5);

                /* De-assert strobe. */
                parport_frob_control (port, PARPORT_CONTROL_STROBE, 0);

                /* Host transfer recovery. */
                parport_pc_data_reverse (port); /* Must be in PS2 mode */
                udelay (5);
                parport_frob_control (port, PARPORT_CONTROL_INIT, 0);
                parport_wait_peripheral (port, PARPORT_STATUS_PAPEROUT, 0);
                parport_frob_control (port,
                                      PARPORT_CONTROL_INIT,
                                      PARPORT_CONTROL_INIT);
                parport_wait_peripheral (port,
                                         PARPORT_STATUS_PAPEROUT,
                                         PARPORT_STATUS_PAPEROUT);
        }

        parport_wait_peripheral (port,
                                 PARPORT_STATUS_BUSY, 
                                 PARPORT_STATUS_BUSY);
        port->physport->ieee1284.phase = IEEE1284_PH_FWD_IDLE;

        return written;
}

size_t parport_pc_ecp_read_block_pio (struct parport *port,
                                      void *buf, size_t length, int flags)
{
        size_t left = length;
        size_t fifofull;
        const int fifo = FIFO(port);
        const struct parport_pc_private *priv = port->physport->private_data;
        const int fifo_depth = priv->fifo_depth;
        char *bufp = buf;

        port = port->physport;

        /* Special case: a timeout of zero means we cannot call schedule(). */
        if (!port->cad->timeout)
                return parport_ieee1284_ecp_read_data (port, buf,
                                                       length, flags);

        fifofull = fifo_depth;
        if (port->ieee1284.mode == IEEE1284_MODE_ECPRLE)
                /* If the peripheral is allowed to send RLE compressed
                 * data, it is possible for a byte to expand to 128
                 * bytes in the FIFO. */
                fifofull = 128;

        /* If the caller wants less than a full FIFO's worth of data,
         * go through software emulation.  Otherwise we may have to through
         * away data. */
        if (length < fifofull)
                return parport_ieee1284_ecp_read_data (port, buf,
                                                       length, flags);

        /* Switch to reverse mode if necessary. */
        if (port->ieee1284.phase != IEEE1284_PH_REV_IDLE) {
                /* Event 38: Set nAutoFd low */
                parport_frob_control (port,
                                      PARPORT_CONTROL_AUTOFD,
                                      PARPORT_CONTROL_AUTOFD);
                parport_pc_data_reverse (port); /* Must be in PS2 mode */
                udelay (5);

                /* Event 39: Set nInit low to initiate bus reversal */
                parport_frob_control (port,
                                      PARPORT_CONTROL_INIT,
                                      0);

                /* Event 40: PError goes low */
                parport_wait_peripheral (port, PARPORT_STATUS_PAPEROUT, 0);
        }

        /* Set up ECP parallel port mode.*/
        parport_pc_data_reverse (port); /* Must be in PS2 mode */
        change_mode (port, ECR_ECP); /* ECP FIFO */
        port->ieee1284.phase = IEEE1284_PH_REV_DATA;

        /* Do the transfer. */
        while (left > fifofull) {
                int ret;
                long int expire = jiffies + port->cad->timeout;
                unsigned char ecrval = inb (ECONTROL (port));

                if (current->need_resched && time_before (jiffies, expire))
                        /* Can't yield the port. */
                        schedule ();

                /* At this point, the FIFO may already be full.
                 * Ideally, we'd be able to tell the port to hold on
                 * for a second while we empty the FIFO, and we'd be
                 * able to ensure that no data is lost.  I'm not sure
                 * that's the case. :-(  It might be that you can play
                 * games with STB, as in the forward case; someone should
                 * look at a datasheet. */

                if (ecrval & 0x01) {
                        /* FIFO is empty. Wait for interrupt. */

                        /* Anyone else waiting for the port? */
                        if (port->waithead) {
                                printk (KERN_DEBUG
                                        "Somebody wants the port\n");
                                break;
                        }

                        /* Clear serviceIntr */
                        outb (ecrval & ~(1<<2), ECONTROL (port));
                false_alarm:
                        ret = parport_wait_event (port, HZ);
                        if (ret < 0) break;
                        ret = 0;
                        if (!time_before (jiffies, expire)) {
                                /* Timed out. */
                                printk (KERN_DEBUG "Timed out\n");
                                break;
                        }
                        ecrval = inb (ECONTROL (port));
                        if (!(ecrval & (1<<2))) {
                                if (current->need_resched &&
                                    time_before (jiffies, expire))
                                        schedule ();

                                goto false_alarm;
                        }

                        continue;
                }

                if (ecrval & 0x02) {
                        /* FIFO is full. */
                        insb (fifo, bufp, fifo_depth);
                        bufp += fifo_depth;
                        left -= fifo_depth;
                        continue;
                }

                *bufp++ = inb (fifo);
                left--;
        }

        /* Finish up. */
        if (change_mode (port, ECR_PS2) == -EBUSY) {
                int lost = get_fifo_residue (port);
                printk (KERN_DEBUG "%s: DATA LOSS (%d bytes)!\n", port->name,
                        lost);
        }

        port->ieee1284.phase = IEEE1284_PH_REV_IDLE;

        return length - left;
}

#endif /* IEEE 1284 support */

#endif /* Allowed to use FIFO/DMA */

void parport_pc_inc_use_count(void)
{
#ifdef MODULE
        MOD_INC_USE_COUNT;
#endif
}

void parport_pc_dec_use_count(void)
{
#ifdef MODULE
        MOD_DEC_USE_COUNT;
#endif
}

struct parport_operations parport_pc_ops = 
{
        parport_pc_write_data,
        parport_pc_read_data,

        parport_pc_write_control,
        parport_pc_read_control,
        parport_pc_frob_control,

        parport_pc_read_status,

        parport_pc_enable_irq,
        parport_pc_disable_irq,

        parport_pc_data_forward,
        parport_pc_data_reverse,

        parport_pc_init_state,
        parport_pc_save_state,
        parport_pc_restore_state,

        parport_pc_inc_use_count,
        parport_pc_dec_use_count,

        parport_ieee1284_epp_write_data,
        parport_ieee1284_epp_read_data,
        parport_ieee1284_epp_write_addr,
        parport_ieee1284_epp_read_addr,

        parport_ieee1284_ecp_write_data,
        parport_ieee1284_ecp_read_data,
        parport_ieee1284_ecp_write_addr,

        parport_ieee1284_write_compat,
        parport_ieee1284_read_nibble,
        parport_ieee1284_read_byte,
};

/* --- Mode detection ------------------------------------- */

/*
 * Checks for port existence, all ports support SPP MODE
 */
static int __maybe_init parport_SPP_supported(struct parport *pb)
{
        unsigned char r, w;

        /*
         * first clear an eventually pending EPP timeout 
         * I (sailer@ife.ee.ethz.ch) have an SMSC chipset
         * that does not even respond to SPP cycles if an EPP
         * timeout is pending
         */
        clear_epp_timeout(pb);

        /* Do a simple read-write test to make sure the port exists. */
        w = 0xc;
        outb (w, CONTROL (pb));

        /* Is there a control register that we can read from?  Some
         * ports don't allow reads, so read_control just returns a
         * software copy. Some ports _do_ allow reads, so bypass the
         * software copy here.  In addition, some bits aren't
         * writable. */
        r = inb (CONTROL (pb));
        if ((r & 0xf) == w) {
                w = 0xe;
                outb (w, CONTROL (pb));
                r = inb (CONTROL (pb));
                outb (0xc, CONTROL (pb));
                if ((r & 0xf) == w)
                        return PARPORT_MODE_PCSPP;
        }

        if (user_specified)
                /* That didn't work, but the user thinks there's a
                 * port here. */
                printk (KERN_DEBUG "0x%lx: CTR: wrote 0x%02x, read 0x%02x\n",
                        pb->base, w, r);

        /* Try the data register.  The data lines aren't tri-stated at
         * this stage, so we expect back what we wrote. */
        w = 0xaa;
        parport_pc_write_data (pb, w);
        r = parport_pc_read_data (pb);
        if (r == w) {
                w = 0x55;
                parport_pc_write_data (pb, w);
                r = parport_pc_read_data (pb);
                if (r == w)
                        return PARPORT_MODE_PCSPP;
        }

        if (user_specified)
                /* Didn't work, but the user is convinced this is the
                 * place. */
                printk (KERN_DEBUG "0x%lx: DATA: wrote 0x%02x, read 0x%02x\n",
                        pb->base, w, r);

        /* It's possible that we can't read the control register or
         * the data register.  In that case just believe the user. */
        if (user_specified)
                return PARPORT_MODE_PCSPP;

        return 0;
}

/* Check for ECR
 *
 * Old style XT ports alias io ports every 0x400, hence accessing ECR
 * on these cards actually accesses the CTR.
 *
 * Modern cards don't do this but reading from ECR will return 0xff
 * regardless of what is written here if the card does NOT support
 * ECP.
 *
 * We first check to see if ECR is the same as CTR.  If not, the low
 * two bits of ECR aren't writable, so we check by writing ECR and
 * reading it back to see if it's what we expect.
 */
static int __maybe_init parport_ECR_present(struct parport *pb)
{
        struct parport_pc_private *priv = pb->private_data;
        unsigned char r = 0xc;

        outb (r, CONTROL (pb));
        if ((inb (ECONTROL (pb)) & 0x3) == (r & 0x3)) {
                outb (r ^ 0x2, CONTROL (pb)); /* Toggle bit 1 */

                r = inb (CONTROL (pb));
                if ((inb (ECONTROL (pb)) & 0x2) == (r & 0x2))
                        goto no_reg; /* Sure that no ECR register exists */
        }
        
        if ((inb (ECONTROL (pb)) & 0x3 ) != 0x1)
                goto no_reg;

        outb (0x34, ECONTROL (pb));
        if (inb (ECONTROL (pb)) != 0x35)
                goto no_reg;

        priv->ecr = 1;
        outb (0xc, CONTROL (pb));
        
        /* Go to mode 000 */
        frob_econtrol (pb, 0xe0, ECR_SPP << 5);

        return 1;

 no_reg:
        outb (0xc, CONTROL (pb));
        return 0; 
}

#ifdef CONFIG_PARPORT_1284
/* Detect PS/2 support.
 *
 * Bit 5 (0x20) sets the PS/2 data direction; setting this high
 * allows us to read data from the data lines.  In theory we would get back
 * 0xff but any peripheral attached to the port may drag some or all of the
 * lines down to zero.  So if we get back anything that isn't the contents
 * of the data register we deem PS/2 support to be present. 
 *
 * Some SPP ports have "half PS/2" ability - you can't turn off the line
 * drivers, but an external peripheral with sufficiently beefy drivers of
 * its own can overpower them and assert its own levels onto the bus, from
 * where they can then be read back as normal.  Ports with this property
 * and the right type of device attached are likely to fail the SPP test,
 * (as they will appear to have stuck bits) and so the fact that they might
 * be misdetected here is rather academic. 
 */

static int __maybe_init parport_PS2_supported(struct parport *pb)
{
        int ok = 0;
  
        clear_epp_timeout(pb);

        /* try to tri-state the buffer */
        parport_pc_data_reverse (pb);
        
        parport_pc_write_data(pb, 0x55);
        if (parport_pc_read_data(pb) != 0x55) ok++;

        parport_pc_write_data(pb, 0xaa);
        if (parport_pc_read_data(pb) != 0xaa) ok++;

        /* cancel input mode */
        parport_pc_data_forward (pb);

        if (ok) {
                pb->modes |= PARPORT_MODE_TRISTATE;
        } else {
                struct parport_pc_private *priv = pb->private_data;
                priv->ctr_writable &= ~0x20;
        }

        return ok;
}

static int __maybe_init parport_ECP_supported(struct parport *pb)
{
        int i;
        int config;
        int pword;
        struct parport_pc_private *priv = pb->private_data;

        /* If there is no ECR, we have no hope of supporting ECP. */
        if (!priv->ecr)
                return 0;

        /* Find out FIFO depth */
        outb (ECR_SPP << 5, ECONTROL (pb)); /* Reset FIFO */
        outb (ECR_TST << 5, ECONTROL (pb)); /* TEST FIFO */
        for (i=0; i < 1024 && !(inb (ECONTROL (pb)) & 0x02); i++)
                outb (0xaa, FIFO (pb));

        /*
         * Using LGS chipset it uses ECR register, but
         * it doesn't support ECP or FIFO MODE
         */
        if (i == 1024) {
                outb (ECR_SPP << 5, ECONTROL (pb));
                return 0;
        }

        priv->fifo_depth = i;
        printk (KERN_INFO "0x%lx: FIFO is %d bytes\n", pb->base, i);

        /* Find out writeIntrThreshold */
        frob_econtrol (pb, 1<<2, 1<<2);
        frob_econtrol (pb, 1<<2, 0);
        for (i = 1; i <= priv->fifo_depth; i++) {
                inb (FIFO (pb));
                udelay (50);
                if (inb (ECONTROL (pb)) & (1<<2))
                        break;
        }

        if (i <= priv->fifo_depth)
                printk (KERN_INFO "0x%lx: writeIntrThreshold is %d\n",
                        pb->base, i);
        else
                /* Number of bytes we know we can write if we get an
                   interrupt. */
                i = 0;

        priv->writeIntrThreshold = i;

        /* Find out readIntrThreshold */
        frob_econtrol (pb, 0xe0, ECR_PS2 << 5); /* Reset FIFO and enable PS2 */
        parport_pc_data_reverse (pb); /* Must be in PS2 mode */
        frob_econtrol (pb, 0xe0, ECR_TST << 5); /* Test FIFO */
        frob_econtrol (pb, 1<<2, 1<<2);
        frob_econtrol (pb, 1<<2, 0);
        for (i = 1; i <= priv->fifo_depth; i++) {
                outb (0xaa, FIFO (pb));
                if (inb (ECONTROL (pb)) & (1<<2))
                        break;
        }

        if (i <= priv->fifo_depth)
                printk (KERN_INFO "0x%lx: readIntrThreshold is %d\n",
                        pb->base, i);
        else
                /* Number of bytes we can read if we get an interrupt. */
                i = 0;

        priv->readIntrThreshold = i;

        outb (ECR_SPP << 5, ECONTROL (pb)); /* Reset FIFO */
        outb (0xf4, ECONTROL (pb)); /* Configuration mode */
        config = inb (FIFO (pb));
        pword = (config >> 4) & 0x7;
        switch (pword) {
        case 0:
                pword = 2;
                printk (KERN_WARNING "0x%lx: Unsupported pword size!\n",
                        pb->base);
                break;
        case 2:
                pword = 4;
                printk (KERN_WARNING "0x%lx: Unsupported pword size!\n",
                        pb->base);
                break;
        default:
                printk (KERN_WARNING "0x%lx: Unknown implementation ID\n",
                        pb->base);
                /* Assume 1 */
        case 1:
                pword = 1;
        }
        priv->pword = pword;
        printk (KERN_DEBUG "0x%lx: PWord is %d bits\n", pb->base, 8 * pword);

        config = inb (CONFIGB (pb));
        printk (KERN_DEBUG "0x%lx: Interrupts are ISA-%s\n", pb->base,
                config & 0x80 ? "Level" : "Pulses");

        if (!(config & 0x40)) {
                printk (KERN_WARNING "0x%lx: IRQ conflict!\n", pb->base);
                pb->irq = PARPORT_IRQ_NONE;
        }

        /* Go back to mode 000 */
        frob_econtrol (pb, 0xe0, ECR_SPP << 5);
        pb->modes |= PARPORT_MODE_ECP;

        return 1;
}

static int __maybe_init parport_ECPPS2_supported(struct parport *pb)
{
        const struct parport_pc_private *priv = pb->private_data;
        int result;
        unsigned char oecr;

        if (!priv->ecr)
                return 0;

        oecr = inb (ECONTROL (pb));
        outb (ECR_PS2 << 5, ECONTROL (pb));
        
        result = parport_PS2_supported(pb);

        outb (oecr, ECONTROL (pb));
        return result;
}

/* EPP mode detection  */

static int __maybe_init parport_EPP_supported(struct parport *pb)
{
        const struct parport_pc_private *priv = pb->private_data;

        /*
         * Theory:
         *      Bit 0 of STR is the EPP timeout bit, this bit is 0
         *      when EPP is possible and is set high when an EPP timeout
         *      occurs (EPP uses the HALT line to stop the CPU while it does
         *      the byte transfer, an EPP timeout occurs if the attached
         *      device fails to respond after 10 micro seconds).
         *
         *      This bit is cleared by either reading it (National Semi)
         *      or writing a 1 to the bit (SMC, UMC, WinBond), others ???
         *      This bit is always high in non EPP modes.
         */

        /* If EPP timeout bit clear then EPP available */
        if (!clear_epp_timeout(pb))
                return 0;  /* No way to clear timeout */

        /* Check for Intel bug. */
        if (priv->ecr) {
                unsigned char i;
                for (i = 0x00; i < 0x80; i += 0x20) {
                        outb (i, ECONTROL (pb));
                        if (clear_epp_timeout (pb))
                                /* Phony EPP in ECP. */
                                return 0;
                }
        }

        pb->modes |= PARPORT_MODE_EPP;

        /* Set up access functions to use EPP hardware. */
        pb->ops->epp_read_data = parport_pc_epp_read_data;
        pb->ops->epp_write_data = parport_pc_epp_write_data;
        pb->ops->epp_read_addr = parport_pc_epp_read_addr;
        pb->ops->epp_write_addr = parport_pc_epp_write_addr;

        return 1;
}

static int __maybe_init parport_ECPEPP_supported(struct parport *pb)
{
        struct parport_pc_private *priv = pb->private_data;
        int result;
        unsigned char oecr;

        if (!priv->ecr)
                return 0;

        oecr = inb (ECONTROL (pb));
        /* Search for SMC style EPP+ECP mode */
        outb (0x80, ECONTROL (pb));
        
        result = parport_EPP_supported(pb);

        outb (oecr, ECONTROL (pb));

        if (result) {
                /* Set up access functions to use ECP+EPP hardware. */
                pb->ops->epp_read_data = parport_pc_ecpepp_read_data;
                pb->ops->epp_write_data = parport_pc_ecpepp_write_data;
                pb->ops->epp_read_addr = parport_pc_ecpepp_read_addr;
                pb->ops->epp_write_addr = parport_pc_ecpepp_write_addr;
        }

        return result;
}

#else /* No IEEE 1284 support */

/* Don't bother probing for modes we know we won't use. */
static int __maybe_init parport_PS2_supported(struct parport *pb) { return 0; }
static int __maybe_init parport_ECP_supported(struct parport *pb) { return 0; }
static int __maybe_init parport_EPP_supported(struct parport *pb) { return 0; }
static int __maybe_init parport_ECPEPP_supported(struct parport *pb){return 0;}
static int __maybe_init parport_ECPPS2_supported(struct parport *pb){return 0;}

#endif /* No IEEE 1284 support */

/* --- IRQ detection -------------------------------------- */

/* Only if supports ECP mode */
static int __maybe_init programmable_irq_support(struct parport *pb)
{
        int irq, intrLine;
        unsigned char oecr = inb (ECONTROL (pb));
        static const int lookup[8] = {
                PARPORT_IRQ_NONE, 7, 9, 10, 11, 14, 15, 5
        };

        outb (ECR_CNF << 5, ECONTROL (pb)); /* Configuration MODE */

        intrLine = (inb (CONFIGB (pb)) >> 3) & 0x07;
        irq = lookup[intrLine];

        outb (oecr, ECONTROL (pb));
        return irq;
}

static int __maybe_init irq_probe_ECP(struct parport *pb)
{
        int i;
        unsigned long irqs;

        sti();
        irqs = probe_irq_on();
                
        outb (ECR_SPP << 5, ECONTROL (pb)); /* Reset FIFO */
        outb ((ECR_TST << 5) | 0x04, ECONTROL (pb));
        outb (ECR_TST << 5, ECONTROL (pb));

        /* If Full FIFO sure that writeIntrThreshold is generated */
        for (i=0; i < 1024 && !(inb (ECONTROL (pb)) & 0x02) ; i++) 
                outb (0xaa, FIFO (pb));
                
        pb->irq = probe_irq_off(irqs);
        outb (ECR_SPP << 5, ECONTROL (pb));

        if (pb->irq <= 0)
                pb->irq = PARPORT_IRQ_NONE;

        return pb->irq;
}

/*
 * This detection seems that only works in National Semiconductors
 * This doesn't work in SMC, LGS, and Winbond 
 */
static int __maybe_init irq_probe_EPP(struct parport *pb)
{
#ifndef ADVANCED_DETECT
        return PARPORT_IRQ_NONE;
#else
        int irqs;
        unsigned char oecr;

        if (pb->modes & PARPORT_MODE_PCECR)
                oecr = inb (ECONTROL (pb));

        sti();
        irqs = probe_irq_on();

        if (pb->modes & PARPORT_MODE_PCECR)
                frob_econtrol (pb, 0x10, 0x10);
        
        clear_epp_timeout(pb);
        parport_pc_frob_control (pb, 0x20, 0x20);
        parport_pc_frob_control (pb, 0x10, 0x10);
        clear_epp_timeout(pb);

        /* Device isn't expecting an EPP read
         * and generates an IRQ.
         */
        parport_pc_read_epp(pb);
        udelay(20);

        pb->irq = probe_irq_off (irqs);
        if (pb->modes & PARPORT_MODE_PCECR)
                outb (oecr, ECONTROL (pb));
        parport_pc_write_control(pb, 0xc);

        if (pb->irq <= 0)
                pb->irq = PARPORT_IRQ_NONE;

        return pb->irq;
#endif /* Advanced detection */
}

static int __maybe_init irq_probe_SPP(struct parport *pb)
{
        /* Don't even try to do this. */
        return PARPORT_IRQ_NONE;
}

/* We will attempt to share interrupt requests since other devices
 * such as sound cards and network cards seem to like using the
 * printer IRQs.
 *
 * When ECP is available we can autoprobe for IRQs.
 * NOTE: If we can autoprobe it, we can register the IRQ.
 */
static int __maybe_init parport_irq_probe(struct parport *pb)
{
        const struct parport_pc_private *priv = pb->private_data;

        if (priv->ecr) {
                pb->irq = programmable_irq_support(pb);
                if (pb->irq != PARPORT_IRQ_NONE)
                        goto out;
        }

        if (pb->modes & PARPORT_MODE_ECP)
                pb->irq = irq_probe_ECP(pb);

        if (pb->irq == PARPORT_IRQ_NONE && priv->ecr &&
            (pb->modes & PARPORT_MODE_EPP))
                pb->irq = irq_probe_EPP(pb);

        clear_epp_timeout(pb);

        if (pb->irq == PARPORT_IRQ_NONE && (pb->modes & PARPORT_MODE_EPP))
                pb->irq = irq_probe_EPP(pb);

        clear_epp_timeout(pb);

        if (pb->irq == PARPORT_IRQ_NONE)
                pb->irq = irq_probe_SPP(pb);

out:
        return pb->irq;
}

/* --- DMA detection -------------------------------------- */

/* Only if supports ECP mode */
static int __maybe_init programmable_dma_support (struct parport *p)
{
        unsigned char oecr = inb (ECONTROL (p));
        int dma;

        frob_econtrol (p, 0xe0, ECR_CNF << 5);
        
        dma = inb (CONFIGB(p)) & 0x03;
        if (!dma)
                dma = PARPORT_DMA_NONE;

        outb (oecr, ECONTROL (p));
        return dma;
}

static int __maybe_init parport_dma_probe (struct parport *p)
{
        const struct parport_pc_private *priv = p->private_data;
        if (priv->ecr)
                p->dma = programmable_dma_support(p);

        return p->dma;
}

/* --- Initialisation code -------------------------------- */

struct parport *__maybe_init parport_pc_probe_port (unsigned long int base,
                                                    unsigned long int base_hi,
                                                    int irq, int dma)
{
        struct parport_pc_private *priv;
        struct parport_operations *ops;
        struct parport tmp;
        struct parport *p = &tmp;
        int probedirq = PARPORT_IRQ_NONE;
        if (check_region(base, 3)) return NULL;
        priv = kmalloc (sizeof (struct parport_pc_private), GFP_KERNEL);
        if (!priv) {
                printk (KERN_DEBUG "parport (0x%lx): no memory!\n", base);
                return NULL;
        }
        ops = kmalloc (sizeof (struct parport_operations), GFP_KERNEL);
        if (!ops) {
                printk (KERN_DEBUG "parport (0x%lx): no memory for ops!\n",
                        base);
                kfree (priv);
                return NULL;
        }
        memcpy (ops, &parport_pc_ops, sizeof (struct parport_operations));
        priv->ctr = 0xc;
        priv->ctr_writable = 0xff;
        priv->ecr = 0;
        priv->fifo_depth = 0;
        priv->dma_buf = 0;
        p->base = base;
        p->base_hi = base_hi;
        p->irq = irq;
        p->dma = dma;
        p->modes = PARPORT_MODE_PCSPP | PARPORT_MODE_SAFEININT;
        p->ops = ops;
        p->private_data = priv;
        p->physport = p;
        if (base_hi && !check_region(base_hi,3)) {
                parport_ECR_present(p);
                parport_ECP_supported(p);
        }
        if (base != 0x3bc) {
                if (!check_region(base+0x3, 5)) {
                        if (!parport_EPP_supported(p))
                                parport_ECPEPP_supported(p);
                }
        }
        if (!parport_SPP_supported (p)) {
                /* No port. */
                kfree (priv);
                return NULL;
        }
        if (priv->ecr)
                parport_ECPPS2_supported(p);
        else
                parport_PS2_supported (p);

        if (!(p = parport_register_port(base, PARPORT_IRQ_NONE,
                                        PARPORT_DMA_NONE, ops))) {
                kfree (priv);
                kfree (ops);
                return NULL;
        }

        p->base_hi = base_hi;
        p->modes = tmp.modes;
        p->size = (p->modes & PARPORT_MODE_EPP)?8:3;
        p->private_data = priv;

        printk(KERN_INFO "%s: PC-style at 0x%lx", p->name, p->base);
        if (p->base_hi && (p->modes & PARPORT_MODE_ECP))
                printk(" (0x%lx)", p->base_hi);
        p->irq = irq;
        p->dma = dma;
        if (p->irq == PARPORT_IRQ_AUTO) {
                p->irq = PARPORT_IRQ_NONE;
                parport_irq_probe(p);
        } else if (p->irq == PARPORT_IRQ_PROBEONLY) {
                p->irq = PARPORT_IRQ_NONE;
                parport_irq_probe(p);
                probedirq = p->irq;
                p->irq = PARPORT_IRQ_NONE;
        }
        if (p->irq != PARPORT_IRQ_NONE) {
                printk(", irq %d", p->irq);

                if (p->dma == PARPORT_DMA_AUTO) {
                        p->dma = PARPORT_DMA_NONE;
                        parport_dma_probe(p);
                }
        }
        if (p->dma == PARPORT_DMA_AUTO)         
                p->dma = PARPORT_DMA_NONE;

#ifdef CONFIG_PARPORT_PC_FIFO
        if (p->dma != PARPORT_DMA_NOFIFO &&
            priv->fifo_depth > 0 && p->irq != PARPORT_IRQ_NONE) {
                p->ops->compat_write_data = parport_pc_compat_write_block_pio;
#ifdef CONFIG_PARPORT_1284
                p->ops->ecp_write_data = parport_pc_ecp_write_block_pio;
#endif /* IEEE 1284 support */
                if (p->dma != PARPORT_DMA_NONE) {
                        printk(", dma %d", p->dma);
                        p->modes |= PARPORT_MODE_DMA;
                }
                else printk(", using FIFO");
        }
        else
                /* We can't use the DMA channel after all. */
                p->dma = PARPORT_DMA_NONE;
#endif /* Allowed to use FIFO/DMA */

        printk(" [");
#define printmode(x) {if(p->modes&PARPORT_MODE_##x){printk("%s%s",f?",":"",#x);f++;}}
        {
                int f = 0;
                printmode(PCSPP);
                printmode(TRISTATE);
                printmode(COMPAT)
                printmode(EPP);
                printmode(ECP);
                printmode(DMA);
        }
#undef printmode
        printk("]\n");
        if (probedirq != PARPORT_IRQ_NONE) 
                printk("%s: irq %d detected\n", p->name, probedirq);
        parport_proc_register(p);

        request_region (p->base, 3, p->name);
        if (p->size > 3)
                request_region (p->base + 3, p->size - 3, p->name);
        if (p->modes & PARPORT_MODE_ECP)
                request_region (p->base_hi, 3, p->name);

        if (p->irq != PARPORT_IRQ_NONE) {
                if (request_irq (p->irq, parport_pc_interrupt,
                                 0, p->name, p)) {
                        printk (KERN_WARNING "%s: irq %d in use, "
                                "resorting to polled operation\n",
                                p->name, p->irq);
                        p->irq = PARPORT_IRQ_NONE;
                        p->dma = PARPORT_DMA_NONE;
                }

                if (p->dma != PARPORT_DMA_NONE) {
                        if (request_dma (p->dma, p->name)) {
                                printk (KERN_WARNING "%s: dma %d in use, "
                                        "resorting to PIO operation\n",
                                        p->name, p->dma);
                                p->dma = PARPORT_DMA_NONE;
                        } else {
                                priv->dma_buf =
                                        (char *)__get_dma_pages(GFP_KERNEL, 0);
                                if (! priv->dma_buf) {
                                        printk (KERN_WARNING "%s: "
                                                "cannot get buffer for DMA, "
                                                "resorting to PIO operation\n",
                                                p->name);
                                        free_dma(p->dma);
                                        p->dma = PARPORT_DMA_NONE;
                                }
                        }
                }
        }

        /* Done probing.  Now put the port into a sensible start-up state.
         * SELECT | INIT also puts IEEE1284-compliant devices into
         * compatibility mode. */
        if (priv->ecr)
                /*
                 * Put the ECP detected port in PS2 mode.
                 * Do this also for ports that have ECR but don't do ECP.
                 */
                outb (0x34, ECONTROL (p));

        parport_pc_write_data(p, 0);
        parport_pc_data_forward (p);
        parport_pc_write_control(p, PARPORT_CONTROL_SELECT);
        udelay (50);
        parport_pc_write_control(p,
                                 PARPORT_CONTROL_SELECT
                                 | PARPORT_CONTROL_INIT);
        udelay (50);

        /* Now that we've told the sharing engine about the port, and
           found out its characteristics, let the high-level drivers
           know about it. */
        parport_announce_port (p);

        return p;
}

/* Look for PCI parallel port cards. */
static int __init parport_pc_init_pci (int irq, int dma)
{
        struct {
                unsigned int vendor;
                unsigned int device;
                unsigned int numports;
                struct {
                        unsigned long lo;
                        unsigned long hi; /* -ve if not there */
                } addr[4];
        } cards[] = {
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S1P_10x_550, 1,
                  { { 3, 4 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S1P_10x_650, 1,
                  { { 3, 4 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S1P_10x_850, 1,
                  { { 3, 4 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1P_10x, 1,
                  { { 2, 3 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2P_10x, 2,
                  { { 2, 3 }, { 4, 5 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S1P_10x_550, 1,
                  { { 4, 5 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S1P_10x_650, 1,
                  { { 4, 5 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S1P_10x_850, 1,
                  { { 4, 5 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1P_20x, 1,
                  { { 0, 1 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2P_20x, 2,
                  { { 0, 1 }, { 2, 3 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2P1S_20x_550, 2,
                  { { 1, 2 }, { 3, 4 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2P1S_20x_650, 2,
                  { { 1, 2 }, { 3, 4 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2P1S_20x_850, 2,
                  { { 1, 2 }, { 3, 4 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S1P_20x_550, 1,
                  { { 1, 2 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S1P_20x_650, 1,
                  { { 1, 2 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_1S1P_20x_850, 1,
                  { { 1, 2 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S1P_20x_550, 1,
                  { { 2, 3 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S1P_20x_650, 1,
                  { { 2, 3 }, } },
                { PCI_VENDOR_ID_SIIG, PCI_DEVICE_ID_SIIG_2S1P_20x_850, 1,
                  { { 2, 3 }, } },
                { PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_PARALLEL, 1,
                  { { 0, -1 }, } },
                { PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_DUAL_PAR_A, 1,
                  { { 0, -1 }, } },
                { PCI_VENDOR_ID_LAVA, PCI_DEVICE_ID_LAVA_DUAL_PAR_B, 1,
                  { { 0, -1 }, } },
                { PCI_VENDOR_ID_EXSYS, PCI_DEVICE_ID_EXSYS_4014, 2,
                  { { 2, -1 }, { 3, -1 }, } },
                { 0, }
        };

        struct pci_dev *pcidev;
        int count = 0;
        int i;

        if (!pci_present ())
                return 0;

        for (i = 0; cards[i].vendor; i++) {
                pcidev = NULL;
                while ((pcidev = pci_find_device (cards[i].vendor,
                                                  cards[i].device,
                                                  pcidev)) != NULL) {
                        int n;
                        for (n = 0; n < cards[i].numports; n++) {
                                unsigned long lo = cards[i].addr[n].lo;
                                unsigned long hi = cards[i].addr[n].hi;
                                unsigned long io_lo, io_hi;
                                io_lo = pcidev->resource[lo].start;
                                io_hi = ((hi < 0) ? 0 :
                                         pcidev->resource[hi].start);
                                if (irq == PARPORT_IRQ_AUTO) {
                                        if (parport_pc_probe_port (io_lo,
                                                                   io_hi,
                                                                   pcidev->irq,
                                                                   dma))
                                                count++;
                                } else if (parport_pc_probe_port (io_lo, io_hi,
                                                                  irq, dma))
                                        count++;
                        }
                }
        }

        /* Look for parallel controllers that we don't know about. */
        for (pcidev = pci_devices; pcidev; pcidev = pcidev->next) {
                const int class_noprogif = pcidev->class & ~0xff;
                if (class_noprogif != (PCI_CLASS_COMMUNICATION_PARALLEL << 8))
                        continue;

                for (i = 0; cards[i].vendor; i++)
                        if ((cards[i].vendor == pcidev->vendor) &&
                            (cards[i].device == pcidev->device))
                                break;
                if (cards[i].vendor)
                        /* We know about this one. */
                        continue;

                printk (KERN_INFO
                        "Unknown PCI parallel I/O card (%04x/%04x)\n"
                        "Please send 'lspci' output to "
                        "tim@cyberelk.demon.co.uk\n",
                        pcidev->vendor, pcidev->device);
        }

        return count;
}

/* Exported symbols. */
#ifdef CONFIG_PARPORT_PC_PCMCIA

/* parport_cs needs this in order to dyncamically get us to find ports. */
EXPORT_SYMBOL (parport_pc_probe_port);

#else

EXPORT_NO_SYMBOLS;

#endif

#ifdef MODULE
static int io[PARPORT_PC_MAX_PORTS+1] = { [0 ... PARPORT_PC_MAX_PORTS] = 0 };
static int io_hi[PARPORT_PC_MAX_PORTS+1] = { [0 ... PARPORT_PC_MAX_PORTS] = 0 };
static int dmaval[PARPORT_PC_MAX_PORTS] = { [0 ... PARPORT_PC_MAX_PORTS-1] = PARPORT_DMA_AUTO };
static int irqval[PARPORT_PC_MAX_PORTS] = { [0 ... PARPORT_PC_MAX_PORTS-1] = PARPORT_IRQ_PROBEONLY };
static const char *irq[PARPORT_PC_MAX_PORTS] = { NULL, };
static const char *dma[PARPORT_PC_MAX_PORTS] = { NULL, };
MODULE_PARM(io, "1-" __MODULE_STRING(PARPORT_PC_MAX_PORTS) "i");
MODULE_PARM(io_hi, "1-" __MODULE_STRING(PARPORT_PC_MAX_PORTS) "i");
MODULE_PARM(irq, "1-" __MODULE_STRING(PARPORT_PC_MAX_PORTS) "s");
MODULE_PARM(dma, "1-" __MODULE_STRING(PARPORT_PC_MAX_PORTS) "s");

int init_module(void)
{       
        /* Work out how many ports we have, then get parport_share to parse
           the irq values. */
        unsigned int i;
        for (i = 0; i < PARPORT_PC_MAX_PORTS && io[i]; i++);
        if (i) {
                if (parport_parse_irqs(i, irq, irqval)) return 1;
                if (parport_parse_dmas(i, dma, dmaval)) return 1;
        }
        else {
                /* The user can make us use any IRQs or DMAs we find. */
                int val;

                if (irq[0] && !parport_parse_irqs (1, irq, &val))
                        switch (val) {
                        case PARPORT_IRQ_NONE:
                        case PARPORT_IRQ_AUTO:
                                irqval[0] = val;
                        }

                if (dma[0] && !parport_parse_dmas (1, dma, &val))
                        switch (val) {
                        case PARPORT_DMA_NONE:
                        case PARPORT_DMA_AUTO:
                                dmaval[0] = val;
                        }
        }

        return (parport_pc_init(io, io_hi, irqval, dmaval)?0:1);
}

void cleanup_module(void)
{
        struct parport *p = parport_enumerate(), *tmp;
        while (p) {
                tmp = p->next;
                if (p->modes & PARPORT_MODE_PCSPP) { 
                        struct parport_pc_private *priv = p->private_data;
                        struct parport_operations *ops = p->ops;
                        if (p->dma != PARPORT_DMA_NONE)
                                free_dma(p->dma);
                        if (p->irq != PARPORT_IRQ_NONE)
                                free_irq(p->irq, p);
                        release_region(p->base, 3);
                        if (p->size > 3)
                                release_region(p->base + 3, p->size - 3);
                        if (p->modes & PARPORT_MODE_ECP)
                                release_region(p->base_hi, 3);
                        parport_proc_unregister(p);
                        if (priv->dma_buf)
                                free_page((unsigned long) priv->dma_buf);
                        kfree (p->private_data);
                        parport_unregister_port(p);
                        kfree (ops); /* hope no-one cached it */
                }
                p = tmp;
        }
}
#endif