radix-tree: fix small lockless radix-tree bug

[linux-2.6/pdupreez.git] / drivers / ata / pata_legacy.c

/*
 *   pata-legacy.c - Legacy port PATA/SATA controller driver.
 *   Copyright 2005/2006 Red Hat <alan@redhat.com>, all rights reserved.
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; see the file COPYING.  If not, write to
 *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *   An ATA driver for the legacy ATA ports.
 *
 *   Data Sources:
 *      Opti 82C465/82C611 support: Data sheets at opti-inc.com
 *      HT6560 series:
 *      Promise 20230/20620:
 *              http://www.ryston.cz/petr/vlb/pdc20230b.html
 *              http://www.ryston.cz/petr/vlb/pdc20230c.html
 *              http://www.ryston.cz/petr/vlb/pdc20630.html
 *
 *  Unsupported but docs exist:
 *      Appian/Adaptec AIC25VL01/Cirrus Logic PD7220
 *
 *  This driver handles legacy (that is "ISA/VLB side") IDE ports found
 *  on PC class systems. There are three hybrid devices that are exceptions
 *  The Cyrix 5510/5520 where a pre SFF ATA device is on the bridge and
 *  the MPIIX where the tuning is PCI side but the IDE is "ISA side".
 *
 *  Specific support is included for the ht6560a/ht6560b/opti82c611a/
 *  opti82c465mv/promise 20230c/20630/winbond83759A
 *
 *  Use the autospeed and pio_mask options with:
 *      Appian ADI/2 aka CLPD7220 or AIC25VL01.
 *  Use the jumpers, autospeed and set pio_mask to the mode on the jumpers with
 *      Goldstar GM82C711, PIC-1288A-125, UMC 82C871F, Winbond W83759,
 *      Winbond W83759A, Promise PDC20230-B
 *
 *  For now use autospeed and pio_mask as above with the W83759A. This may
 *  change.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <scsi/scsi_host.h>
#include <linux/ata.h>
#include <linux/libata.h>
#include <linux/platform_device.h>

#define DRV_NAME "pata_legacy"
#define DRV_VERSION "0.6.5"

#define NR_HOST 6

static int all;
module_param(all, int, 0444);
MODULE_PARM_DESC(all, "Grab all legacy port devices, even if PCI(0=off, 1=on)");

struct legacy_data {
        unsigned long timing;
        u8 clock[2];
        u8 last;
        int fast;
        struct platform_device *platform_dev;

};

enum controller {
        BIOS = 0,
        SNOOP = 1,
        PDC20230 = 2,
        HT6560A = 3,
        HT6560B = 4,
        OPTI611A = 5,
        OPTI46X = 6,
        QDI6500 = 7,
        QDI6580 = 8,
        QDI6580DP = 9,          /* Dual channel mode is different */
        W83759A = 10,

        UNKNOWN = -1
};


struct legacy_probe {
        unsigned char *name;
        unsigned long port;
        unsigned int irq;
        unsigned int slot;
        enum controller type;
        unsigned long private;
};

struct legacy_controller {
        const char *name;
        struct ata_port_operations *ops;
        unsigned int pio_mask;
        unsigned int flags;
        int (*setup)(struct platform_device *, struct legacy_probe *probe,
                struct legacy_data *data);
};

static int legacy_port[NR_HOST] = { 0x1f0, 0x170, 0x1e8, 0x168, 0x1e0, 0x160 };

static struct legacy_probe probe_list[NR_HOST];
static struct legacy_data legacy_data[NR_HOST];
static struct ata_host *legacy_host[NR_HOST];
static int nr_legacy_host;


static int probe_all;           /* Set to check all ISA port ranges */
static int ht6560a;             /* HT 6560A on primary 1, second 2, both 3 */
static int ht6560b;             /* HT 6560A on primary 1, second 2, both 3 */
static int opti82c611a;         /* Opti82c611A on primary 1, sec 2, both 3 */
static int opti82c46x;          /* Opti 82c465MV present(pri/sec autodetect) */
static int qdi;                 /* Set to probe QDI controllers */
static int winbond;             /* Set to probe Winbond controllers,
                                        give I/O port if non standard */
static int autospeed;           /* Chip present which snoops speed changes */
static int pio_mask = 0x1F;     /* PIO range for autospeed devices */
static int iordy_mask = 0xFFFFFFFF;     /* Use iordy if available */

/**
 *      legacy_probe_add        -       Add interface to probe list
 *      @port: Controller port
 *      @irq: IRQ number
 *      @type: Controller type
 *      @private: Controller specific info
 *
 *      Add an entry into the probe list for ATA controllers. This is used
 *      to add the default ISA slots and then to build up the table
 *      further according to other ISA/VLB/Weird device scans
 *
 *      An I/O port list is used to keep ordering stable and sane, as we
 *      don't have any good way to talk about ordering otherwise
 */

static int legacy_probe_add(unsigned long port, unsigned int irq,
                                enum controller type, unsigned long private)
{
        struct legacy_probe *lp = &probe_list[0];
        int i;
        struct legacy_probe *free = NULL;

        for (i = 0; i < NR_HOST; i++) {
                if (lp->port == 0 && free == NULL)
                        free = lp;
                /* Matching port, or the correct slot for ordering */
                if (lp->port == port || legacy_port[i] == port) {
                        free = lp;
                        break;
                }
                lp++;
        }
        if (free == NULL) {
                printk(KERN_ERR "pata_legacy: Too many interfaces.\n");
                return -1;
        }
        /* Fill in the entry for later probing */
        free->port = port;
        free->irq = irq;
        free->type = type;
        free->private = private;
        return 0;
}


/**
 *      legacy_set_mode         -       mode setting
 *      @link: IDE link
 *      @unused: Device that failed when error is returned
 *
 *      Use a non standard set_mode function. We don't want to be tuned.
 *
 *      The BIOS configured everything. Our job is not to fiddle. Just use
 *      whatever PIO the hardware is using and leave it at that. When we
 *      get some kind of nice user driven API for control then we can
 *      expand on this as per hdparm in the base kernel.
 */

static int legacy_set_mode(struct ata_link *link, struct ata_device **unused)
{
        struct ata_device *dev;

        ata_link_for_each_dev(dev, link) {
                if (ata_dev_enabled(dev)) {
                        ata_dev_printk(dev, KERN_INFO,
                                                "configured for PIO\n");
                        dev->pio_mode = XFER_PIO_0;
                        dev->xfer_mode = XFER_PIO_0;
                        dev->xfer_shift = ATA_SHIFT_PIO;
                        dev->flags |= ATA_DFLAG_PIO;
                }
        }
        return 0;
}

static struct scsi_host_template legacy_sht = {
        ATA_PIO_SHT(DRV_NAME),
};

static const struct ata_port_operations legacy_base_port_ops = {
        .inherits       = &ata_sff_port_ops,
        .cable_detect   = ata_cable_40wire,
};

/*
 *      These ops are used if the user indicates the hardware
 *      snoops the commands to decide on the mode and handles the
 *      mode selection "magically" itself. Several legacy controllers
 *      do this. The mode range can be set if it is not 0x1F by setting
 *      pio_mask as well.
 */

static struct ata_port_operations simple_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .sff_data_xfer  = ata_sff_data_xfer_noirq,
};

static struct ata_port_operations legacy_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .sff_data_xfer  = ata_sff_data_xfer_noirq,
        .set_mode       = legacy_set_mode,
};

/*
 *      Promise 20230C and 20620 support
 *
 *      This controller supports PIO0 to PIO2. We set PIO timings
 *      conservatively to allow for 50MHz Vesa Local Bus. The 20620 DMA
 *      support is weird being DMA to controller and PIO'd to the host
 *      and not supported.
 */

static void pdc20230_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        int tries = 5;
        int pio = adev->pio_mode - XFER_PIO_0;
        u8 rt;
        unsigned long flags;

        /* Safe as UP only. Force I/Os to occur together */

        local_irq_save(flags);

        /* Unlock the control interface */
        do {
                inb(0x1F5);
                outb(inb(0x1F2) | 0x80, 0x1F2);
                inb(0x1F2);
                inb(0x3F6);
                inb(0x3F6);
                inb(0x1F2);
                inb(0x1F2);
        }
        while ((inb(0x1F2) & 0x80) && --tries);

        local_irq_restore(flags);

        outb(inb(0x1F4) & 0x07, 0x1F4);

        rt = inb(0x1F3);
        rt &= 0x07 << (3 * adev->devno);
        if (pio)
                rt |= (1 + 3 * pio) << (3 * adev->devno);

        udelay(100);
        outb(inb(0x1F2) | 0x01, 0x1F2);
        udelay(100);
        inb(0x1F5);

}

static unsigned int pdc_data_xfer_vlb(struct ata_device *dev,
                        unsigned char *buf, unsigned int buflen, int rw)
{
        if (ata_id_has_dword_io(dev->id)) {
                struct ata_port *ap = dev->link->ap;
                int slop = buflen & 3;
                unsigned long flags;

                local_irq_save(flags);

                /* Perform the 32bit I/O synchronization sequence */
                ioread8(ap->ioaddr.nsect_addr);
                ioread8(ap->ioaddr.nsect_addr);
                ioread8(ap->ioaddr.nsect_addr);

                /* Now the data */
                if (rw == READ)
                        ioread32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);
                else
                        iowrite32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);

                if (unlikely(slop)) {
                        u32 pad;
                        if (rw == READ) {
                                pad = cpu_to_le32(ioread32(ap->ioaddr.data_addr));
                                memcpy(buf + buflen - slop, &pad, slop);
                        } else {
                                memcpy(&pad, buf + buflen - slop, slop);
                                iowrite32(le32_to_cpu(pad), ap->ioaddr.data_addr);
                        }
                        buflen += 4 - slop;
                }
                local_irq_restore(flags);
        } else
                buflen = ata_sff_data_xfer_noirq(dev, buf, buflen, rw);

        return buflen;
}

static struct ata_port_operations pdc20230_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = pdc20230_set_piomode,
        .sff_data_xfer  = pdc_data_xfer_vlb,
};

/*
 *      Holtek 6560A support
 *
 *      This controller supports PIO0 to PIO2 (no IORDY even though higher
 *      timings can be loaded).
 */

static void ht6560a_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        u8 active, recover;
        struct ata_timing t;

        /* Get the timing data in cycles. For now play safe at 50Mhz */
        ata_timing_compute(adev, adev->pio_mode, &t, 20000, 1000);

        active = clamp_val(t.active, 2, 15);
        recover = clamp_val(t.recover, 4, 15);

        inb(0x3E6);
        inb(0x3E6);
        inb(0x3E6);
        inb(0x3E6);

        iowrite8(recover << 4 | active, ap->ioaddr.device_addr);
        ioread8(ap->ioaddr.status_addr);
}

static struct ata_port_operations ht6560a_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = ht6560a_set_piomode,
};

/*
 *      Holtek 6560B support
 *
 *      This controller supports PIO0 to PIO4. We honour the BIOS/jumper FIFO
 *      setting unless we see an ATAPI device in which case we force it off.
 *
 *      FIXME: need to implement 2nd channel support.
 */

static void ht6560b_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        u8 active, recover;
        struct ata_timing t;

        /* Get the timing data in cycles. For now play safe at 50Mhz */
        ata_timing_compute(adev, adev->pio_mode, &t, 20000, 1000);

        active = clamp_val(t.active, 2, 15);
        recover = clamp_val(t.recover, 2, 16);
        recover &= 0x15;

        inb(0x3E6);
        inb(0x3E6);
        inb(0x3E6);
        inb(0x3E6);

        iowrite8(recover << 4 | active, ap->ioaddr.device_addr);

        if (adev->class != ATA_DEV_ATA) {
                u8 rconf = inb(0x3E6);
                if (rconf & 0x24) {
                        rconf &= ~0x24;
                        outb(rconf, 0x3E6);
                }
        }
        ioread8(ap->ioaddr.status_addr);
}

static struct ata_port_operations ht6560b_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = ht6560b_set_piomode,
};

/*
 *      Opti core chipset helpers
 */

/**
 *      opti_syscfg     -       read OPTI chipset configuration
 *      @reg: Configuration register to read
 *
 *      Returns the value of an OPTI system board configuration register.
 */

static u8 opti_syscfg(u8 reg)
{
        unsigned long flags;
        u8 r;

        /* Uniprocessor chipset and must force cycles adjancent */
        local_irq_save(flags);
        outb(reg, 0x22);
        r = inb(0x24);
        local_irq_restore(flags);
        return r;
}

/*
 *      Opti 82C611A
 *
 *      This controller supports PIO0 to PIO3.
 */

static void opti82c611a_set_piomode(struct ata_port *ap,
                                                struct ata_device *adev)
{
        u8 active, recover, setup;
        struct ata_timing t;
        struct ata_device *pair = ata_dev_pair(adev);
        int clock;
        int khz[4] = { 50000, 40000, 33000, 25000 };
        u8 rc;

        /* Enter configuration mode */
        ioread16(ap->ioaddr.error_addr);
        ioread16(ap->ioaddr.error_addr);
        iowrite8(3, ap->ioaddr.nsect_addr);

        /* Read VLB clock strapping */
        clock = 1000000000 / khz[ioread8(ap->ioaddr.lbah_addr) & 0x03];

        /* Get the timing data in cycles */
        ata_timing_compute(adev, adev->pio_mode, &t, clock, 1000);

        /* Setup timing is shared */
        if (pair) {
                struct ata_timing tp;
                ata_timing_compute(pair, pair->pio_mode, &tp, clock, 1000);

                ata_timing_merge(&t, &tp, &t, ATA_TIMING_SETUP);
        }

        active = clamp_val(t.active, 2, 17) - 2;
        recover = clamp_val(t.recover, 1, 16) - 1;
        setup = clamp_val(t.setup, 1, 4) - 1;

        /* Select the right timing bank for write timing */
        rc = ioread8(ap->ioaddr.lbal_addr);
        rc &= 0x7F;
        rc |= (adev->devno << 7);
        iowrite8(rc, ap->ioaddr.lbal_addr);

        /* Write the timings */
        iowrite8(active << 4 | recover, ap->ioaddr.error_addr);

        /* Select the right bank for read timings, also
           load the shared timings for address */
        rc = ioread8(ap->ioaddr.device_addr);
        rc &= 0xC0;
        rc |= adev->devno;      /* Index select */
        rc |= (setup << 4) | 0x04;
        iowrite8(rc, ap->ioaddr.device_addr);

        /* Load the read timings */
        iowrite8(active << 4 | recover, ap->ioaddr.data_addr);

        /* Ensure the timing register mode is right */
        rc = ioread8(ap->ioaddr.lbal_addr);
        rc &= 0x73;
        rc |= 0x84;
        iowrite8(rc, ap->ioaddr.lbal_addr);

        /* Exit command mode */
        iowrite8(0x83,  ap->ioaddr.nsect_addr);
}


static struct ata_port_operations opti82c611a_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = opti82c611a_set_piomode,
};

/*
 *      Opti 82C465MV
 *
 *      This controller supports PIO0 to PIO3. Unlike the 611A the MVB
 *      version is dual channel but doesn't have a lot of unique registers.
 */

static void opti82c46x_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        u8 active, recover, setup;
        struct ata_timing t;
        struct ata_device *pair = ata_dev_pair(adev);
        int clock;
        int khz[4] = { 50000, 40000, 33000, 25000 };
        u8 rc;
        u8 sysclk;

        /* Get the clock */
        sysclk = opti_syscfg(0xAC) & 0xC0;      /* BIOS set */

        /* Enter configuration mode */
        ioread16(ap->ioaddr.error_addr);
        ioread16(ap->ioaddr.error_addr);
        iowrite8(3, ap->ioaddr.nsect_addr);

        /* Read VLB clock strapping */
        clock = 1000000000 / khz[sysclk];

        /* Get the timing data in cycles */
        ata_timing_compute(adev, adev->pio_mode, &t, clock, 1000);

        /* Setup timing is shared */
        if (pair) {
                struct ata_timing tp;
                ata_timing_compute(pair, pair->pio_mode, &tp, clock, 1000);

                ata_timing_merge(&t, &tp, &t, ATA_TIMING_SETUP);
        }

        active = clamp_val(t.active, 2, 17) - 2;
        recover = clamp_val(t.recover, 1, 16) - 1;
        setup = clamp_val(t.setup, 1, 4) - 1;

        /* Select the right timing bank for write timing */
        rc = ioread8(ap->ioaddr.lbal_addr);
        rc &= 0x7F;
        rc |= (adev->devno << 7);
        iowrite8(rc, ap->ioaddr.lbal_addr);

        /* Write the timings */
        iowrite8(active << 4 | recover, ap->ioaddr.error_addr);

        /* Select the right bank for read timings, also
           load the shared timings for address */
        rc = ioread8(ap->ioaddr.device_addr);
        rc &= 0xC0;
        rc |= adev->devno;      /* Index select */
        rc |= (setup << 4) | 0x04;
        iowrite8(rc, ap->ioaddr.device_addr);

        /* Load the read timings */
        iowrite8(active << 4 | recover, ap->ioaddr.data_addr);

        /* Ensure the timing register mode is right */
        rc = ioread8(ap->ioaddr.lbal_addr);
        rc &= 0x73;
        rc |= 0x84;
        iowrite8(rc, ap->ioaddr.lbal_addr);

        /* Exit command mode */
        iowrite8(0x83,  ap->ioaddr.nsect_addr);

        /* We need to know this for quad device on the MVB */
        ap->host->private_data = ap;
}

/**
 *      opt82c465mv_qc_issue            -       command issue
 *      @qc: command pending
 *
 *      Called when the libata layer is about to issue a command. We wrap
 *      this interface so that we can load the correct ATA timings. The
 *      MVB has a single set of timing registers and these are shared
 *      across channels. As there are two registers we really ought to
 *      track the last two used values as a sort of register window. For
 *      now we just reload on a channel switch. On the single channel
 *      setup this condition never fires so we do nothing extra.
 *
 *      FIXME: dual channel needs ->serialize support
 */

static unsigned int opti82c46x_qc_issue(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ata_device *adev = qc->dev;

        /* If timings are set and for the wrong channel (2nd test is
           due to a libata shortcoming and will eventually go I hope) */
        if (ap->host->private_data != ap->host
            && ap->host->private_data != NULL)
                opti82c46x_set_piomode(ap, adev);

        return ata_sff_qc_issue(qc);
}

static struct ata_port_operations opti82c46x_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = opti82c46x_set_piomode,
        .qc_issue       = opti82c46x_qc_issue,
};

static void qdi6500_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        struct ata_timing t;
        struct legacy_data *ld_qdi = ap->host->private_data;
        int active, recovery;
        u8 timing;

        /* Get the timing data in cycles */
        ata_timing_compute(adev, adev->pio_mode, &t, 30303, 1000);

        if (ld_qdi->fast) {
                active = 8 - clamp_val(t.active, 1, 8);
                recovery = 18 - clamp_val(t.recover, 3, 18);
        } else {
                active = 9 - clamp_val(t.active, 2, 9);
                recovery = 15 - clamp_val(t.recover, 0, 15);
        }
        timing = (recovery << 4) | active | 0x08;

        ld_qdi->clock[adev->devno] = timing;

        outb(timing, ld_qdi->timing);
}

/**
 *      qdi6580dp_set_piomode           -       PIO setup for dual channel
 *      @ap: Port
 *      @adev: Device
 *      @irq: interrupt line
 *
 *      In dual channel mode the 6580 has one clock per channel and we have
 *      to software clockswitch in qc_issue.
 */

static void qdi6580dp_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        struct ata_timing t;
        struct legacy_data *ld_qdi = ap->host->private_data;
        int active, recovery;
        u8 timing;

        /* Get the timing data in cycles */
        ata_timing_compute(adev, adev->pio_mode, &t, 30303, 1000);

        if (ld_qdi->fast) {
                active = 8 - clamp_val(t.active, 1, 8);
                recovery = 18 - clamp_val(t.recover, 3, 18);
        } else {
                active = 9 - clamp_val(t.active, 2, 9);
                recovery = 15 - clamp_val(t.recover, 0, 15);
        }
        timing = (recovery << 4) | active | 0x08;

        ld_qdi->clock[adev->devno] = timing;

        outb(timing, ld_qdi->timing + 2 * ap->port_no);
        /* Clear the FIFO */
        if (adev->class != ATA_DEV_ATA)
                outb(0x5F, ld_qdi->timing + 3);
}

/**
 *      qdi6580_set_piomode             -       PIO setup for single channel
 *      @ap: Port
 *      @adev: Device
 *
 *      In single channel mode the 6580 has one clock per device and we can
 *      avoid the requirement to clock switch. We also have to load the timing
 *      into the right clock according to whether we are master or slave.
 */

static void qdi6580_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        struct ata_timing t;
        struct legacy_data *ld_qdi = ap->host->private_data;
        int active, recovery;
        u8 timing;

        /* Get the timing data in cycles */
        ata_timing_compute(adev, adev->pio_mode, &t, 30303, 1000);

        if (ld_qdi->fast) {
                active = 8 - clamp_val(t.active, 1, 8);
                recovery = 18 - clamp_val(t.recover, 3, 18);
        } else {
                active = 9 - clamp_val(t.active, 2, 9);
                recovery = 15 - clamp_val(t.recover, 0, 15);
        }
        timing = (recovery << 4) | active | 0x08;
        ld_qdi->clock[adev->devno] = timing;
        outb(timing, ld_qdi->timing + 2 * adev->devno);
        /* Clear the FIFO */
        if (adev->class != ATA_DEV_ATA)
                outb(0x5F, ld_qdi->timing + 3);
}

/**
 *      qdi_qc_issue            -       command issue
 *      @qc: command pending
 *
 *      Called when the libata layer is about to issue a command. We wrap
 *      this interface so that we can load the correct ATA timings.
 */

static unsigned int qdi_qc_issue(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ata_device *adev = qc->dev;
        struct legacy_data *ld_qdi = ap->host->private_data;

        if (ld_qdi->clock[adev->devno] != ld_qdi->last) {
                if (adev->pio_mode) {
                        ld_qdi->last = ld_qdi->clock[adev->devno];
                        outb(ld_qdi->clock[adev->devno], ld_qdi->timing +
                                                        2 * ap->port_no);
                }
        }
        return ata_sff_qc_issue(qc);
}

static unsigned int vlb32_data_xfer(struct ata_device *adev, unsigned char *buf,
                                        unsigned int buflen, int rw)
{
        struct ata_port *ap = adev->link->ap;
        int slop = buflen & 3;

        if (ata_id_has_dword_io(adev->id)) {
                if (rw == WRITE)
                        iowrite32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);
                else
                        ioread32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);

                if (unlikely(slop)) {
                        u32 pad;
                        if (rw == WRITE) {
                                memcpy(&pad, buf + buflen - slop, slop);
                                pad = le32_to_cpu(pad);
                                iowrite32(pad, ap->ioaddr.data_addr);
                        } else {
                                pad = ioread32(ap->ioaddr.data_addr);
                                pad = cpu_to_le32(pad);
                                memcpy(buf + buflen - slop, &pad, slop);
                        }
                }
                return (buflen + 3) & ~3;
        } else
                return ata_sff_data_xfer(adev, buf, buflen, rw);
}

static int qdi_port(struct platform_device *dev,
                        struct legacy_probe *lp, struct legacy_data *ld)
{
        if (devm_request_region(&dev->dev, lp->private, 4, "qdi") == NULL)
                return -EBUSY;
        ld->timing = lp->private;
        return 0;
}

static struct ata_port_operations qdi6500_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = qdi6500_set_piomode,
        .qc_issue       = qdi_qc_issue,
        .sff_data_xfer  = vlb32_data_xfer,
};

static struct ata_port_operations qdi6580_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = qdi6580_set_piomode,
        .sff_data_xfer  = vlb32_data_xfer,
};

static struct ata_port_operations qdi6580dp_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = qdi6580dp_set_piomode,
        .sff_data_xfer  = vlb32_data_xfer,
};

static DEFINE_SPINLOCK(winbond_lock);

static void winbond_writecfg(unsigned long port, u8 reg, u8 val)
{
        unsigned long flags;
        spin_lock_irqsave(&winbond_lock, flags);
        outb(reg, port + 0x01);
        outb(val, port + 0x02);
        spin_unlock_irqrestore(&winbond_lock, flags);
}

static u8 winbond_readcfg(unsigned long port, u8 reg)
{
        u8 val;

        unsigned long flags;
        spin_lock_irqsave(&winbond_lock, flags);
        outb(reg, port + 0x01);
        val = inb(port + 0x02);
        spin_unlock_irqrestore(&winbond_lock, flags);

        return val;
}

static void winbond_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        struct ata_timing t;
        struct legacy_data *ld_winbond = ap->host->private_data;
        int active, recovery;
        u8 reg;
        int timing = 0x88 + (ap->port_no * 4) + (adev->devno * 2);

        reg = winbond_readcfg(ld_winbond->timing, 0x81);

        /* Get the timing data in cycles */
        if (reg & 0x40)         /* Fast VLB bus, assume 50MHz */
                ata_timing_compute(adev, adev->pio_mode, &t, 20000, 1000);
        else
                ata_timing_compute(adev, adev->pio_mode, &t, 30303, 1000);

        active = (clamp_val(t.active, 3, 17) - 1) & 0x0F;
        recovery = (clamp_val(t.recover, 1, 15) + 1) & 0x0F;
        timing = (active << 4) | recovery;
        winbond_writecfg(ld_winbond->timing, timing, reg);

        /* Load the setup timing */

        reg = 0x35;
        if (adev->class != ATA_DEV_ATA)
                reg |= 0x08;    /* FIFO off */
        if (!ata_pio_need_iordy(adev))
                reg |= 0x02;    /* IORDY off */
        reg |= (clamp_val(t.setup, 0, 3) << 6);
        winbond_writecfg(ld_winbond->timing, timing + 1, reg);
}

static int winbond_port(struct platform_device *dev,
                        struct legacy_probe *lp, struct legacy_data *ld)
{
        if (devm_request_region(&dev->dev, lp->private, 4, "winbond") == NULL)
                return -EBUSY;
        ld->timing = lp->private;
        return 0;
}

static struct ata_port_operations winbond_port_ops = {
        .inherits       = &legacy_base_port_ops,
        .set_piomode    = winbond_set_piomode,
        .sff_data_xfer  = vlb32_data_xfer,
};

static struct legacy_controller controllers[] = {
        {"BIOS",        &legacy_port_ops,       0x1F,
                                                ATA_FLAG_NO_IORDY,      NULL },
        {"Snooping",    &simple_port_ops,       0x1F,
                                                0              ,        NULL },
        {"PDC20230",    &pdc20230_port_ops,     0x7,
                                                ATA_FLAG_NO_IORDY,      NULL },
        {"HT6560A",     &ht6560a_port_ops,      0x07,
                                                ATA_FLAG_NO_IORDY,      NULL },
        {"HT6560B",     &ht6560b_port_ops,      0x1F,
                                                ATA_FLAG_NO_IORDY,      NULL },
        {"OPTI82C611A", &opti82c611a_port_ops,  0x0F,
                                                0              ,        NULL },
        {"OPTI82C46X",  &opti82c46x_port_ops,   0x0F,
                                                0              ,        NULL },
        {"QDI6500",     &qdi6500_port_ops,      0x07,
                                        ATA_FLAG_NO_IORDY,      qdi_port },
        {"QDI6580",     &qdi6580_port_ops,      0x1F,
                                        0              ,        qdi_port },
        {"QDI6580DP",   &qdi6580dp_port_ops,    0x1F,
                                        0              ,        qdi_port },
        {"W83759A",     &winbond_port_ops,      0x1F,
                                        0              ,        winbond_port }
};

/**
 *      probe_chip_type         -       Discover controller
 *      @probe: Probe entry to check
 *
 *      Probe an ATA port and identify the type of controller. We don't
 *      check if the controller appears to be driveless at this point.
 */

static __init int probe_chip_type(struct legacy_probe *probe)
{
        int mask = 1 << probe->slot;

        if (winbond && (probe->port == 0x1F0 || probe->port == 0x170)) {
                u8 reg = winbond_readcfg(winbond, 0x81);
                reg |= 0x80;    /* jumpered mode off */
                winbond_writecfg(winbond, 0x81, reg);
                reg = winbond_readcfg(winbond, 0x83);
                reg |= 0xF0;    /* local control */
                winbond_writecfg(winbond, 0x83, reg);
                reg = winbond_readcfg(winbond, 0x85);
                reg |= 0xF0;    /* programmable timing */
                winbond_writecfg(winbond, 0x85, reg);

                reg = winbond_readcfg(winbond, 0x81);

                if (reg & mask)
                        return W83759A;
        }
        if (probe->port == 0x1F0) {
                unsigned long flags;
                local_irq_save(flags);
                /* Probes */
                outb(inb(0x1F2) | 0x80, 0x1F2);
                inb(0x1F5);
                inb(0x1F2);
                inb(0x3F6);
                inb(0x3F6);
                inb(0x1F2);
                inb(0x1F2);

                if ((inb(0x1F2) & 0x80) == 0) {
                        /* PDC20230c or 20630 ? */
                        printk(KERN_INFO  "PDC20230-C/20630 VLB ATA controller"
                                                        " detected.\n");
                        udelay(100);
                        inb(0x1F5);
                        local_irq_restore(flags);
                        return PDC20230;
                } else {
                        outb(0x55, 0x1F2);
                        inb(0x1F2);
                        inb(0x1F2);
                        if (inb(0x1F2) == 0x00)
                                printk(KERN_INFO "PDC20230-B VLB ATA "
                                                     "controller detected.\n");
                        local_irq_restore(flags);
                        return BIOS;
                }
                local_irq_restore(flags);
        }

        if (ht6560a & mask)
                return HT6560A;
        if (ht6560b & mask)
                return HT6560B;
        if (opti82c611a & mask)
                return OPTI611A;
        if (opti82c46x & mask)
                return OPTI46X;
        if (autospeed & mask)
                return SNOOP;
        return BIOS;
}


/**
 *      legacy_init_one         -       attach a legacy interface
 *      @pl: probe record
 *
 *      Register an ISA bus IDE interface. Such interfaces are PIO and we
 *      assume do not support IRQ sharing.
 */

static __init int legacy_init_one(struct legacy_probe *probe)
{
        struct legacy_controller *controller = &controllers[probe->type];
        int pio_modes = controller->pio_mask;
        unsigned long io = probe->port;
        u32 mask = (1 << probe->slot);
        struct ata_port_operations *ops = controller->ops;
        struct legacy_data *ld = &legacy_data[probe->slot];
        struct ata_host *host = NULL;
        struct ata_port *ap;
        struct platform_device *pdev;
        struct ata_device *dev;
        void __iomem *io_addr, *ctrl_addr;
        u32 iordy = (iordy_mask & mask) ? 0: ATA_FLAG_NO_IORDY;
        int ret;

        iordy |= controller->flags;

        pdev = platform_device_register_simple(DRV_NAME, probe->slot, NULL, 0);
        if (IS_ERR(pdev))
                return PTR_ERR(pdev);

        ret = -EBUSY;
        if (devm_request_region(&pdev->dev, io, 8, "pata_legacy") == NULL ||
            devm_request_region(&pdev->dev, io + 0x0206, 1,
                                                        "pata_legacy") == NULL)
                goto fail;

        ret = -ENOMEM;
        io_addr = devm_ioport_map(&pdev->dev, io, 8);
        ctrl_addr = devm_ioport_map(&pdev->dev, io + 0x0206, 1);
        if (!io_addr || !ctrl_addr)
                goto fail;
        if (controller->setup)
                if (controller->setup(pdev, probe, ld) < 0)
                        goto fail;
        host = ata_host_alloc(&pdev->dev, 1);
        if (!host)
                goto fail;
        ap = host->ports[0];

        ap->ops = ops;
        ap->pio_mask = pio_modes;
        ap->flags |= ATA_FLAG_SLAVE_POSS | iordy;
        ap->ioaddr.cmd_addr = io_addr;
        ap->ioaddr.altstatus_addr = ctrl_addr;
        ap->ioaddr.ctl_addr = ctrl_addr;
        ata_sff_std_ports(&ap->ioaddr);
        ap->host->private_data = ld;

        ata_port_desc(ap, "cmd 0x%lx ctl 0x%lx", io, io + 0x0206);

        ret = ata_host_activate(host, probe->irq, ata_sff_interrupt, 0,
                                &legacy_sht);
        if (ret)
                goto fail;
        ld->platform_dev = pdev;

        /* Nothing found means we drop the port as its probably not there */

        ret = -ENODEV;
        ata_link_for_each_dev(dev, &ap->link) {
                if (!ata_dev_absent(dev)) {
                        legacy_host[probe->slot] = host;
                        ld->platform_dev = pdev;
                        return 0;
                }
        }
fail:
        platform_device_unregister(pdev);
        return ret;
}

/**
 *      legacy_check_special_cases      -       ATA special cases
 *      @p: PCI device to check
 *      @master: set this if we find an ATA master
 *      @master: set this if we find an ATA secondary
 *
 *      A small number of vendors implemented early PCI ATA interfaces
 *      on bridge logic without the ATA interface being PCI visible.
 *      Where we have a matching PCI driver we must skip the relevant
 *      device here. If we don't know about it then the legacy driver
 *      is the right driver anyway.
 */

static void __init legacy_check_special_cases(struct pci_dev *p, int *primary,
                                                                int *secondary)
{
        /* Cyrix CS5510 pre SFF MWDMA ATA on the bridge */
        if (p->vendor == 0x1078 && p->device == 0x0000) {
                *primary = *secondary = 1;
                return;
        }
        /* Cyrix CS5520 pre SFF MWDMA ATA on the bridge */
        if (p->vendor == 0x1078 && p->device == 0x0002) {
                *primary = *secondary = 1;
                return;
        }
        /* Intel MPIIX - PIO ATA on non PCI side of bridge */
        if (p->vendor == 0x8086 && p->device == 0x1234) {
                u16 r;
                pci_read_config_word(p, 0x6C, &r);
                if (r & 0x8000) {
                        /* ATA port enabled */
                        if (r & 0x4000)
                                *secondary = 1;
                        else
                                *primary = 1;
                }
                return;
        }
}

static __init void probe_opti_vlb(void)
{
        /* If an OPTI 82C46X is present find out where the channels are */
        static const char *optis[4] = {
                "3/463MV", "5MV",
                "5MVA", "5MVB"
        };
        u8 chans = 1;
        u8 ctrl = (opti_syscfg(0x30) & 0xC0) >> 6;

        opti82c46x = 3; /* Assume master and slave first */
        printk(KERN_INFO DRV_NAME ": Opti 82C46%s chipset support.\n",
                                                                optis[ctrl]);
        if (ctrl == 3)
                chans = (opti_syscfg(0x3F) & 0x20) ? 2 : 1;
        ctrl = opti_syscfg(0xAC);
        /* Check enabled and this port is the 465MV port. On the
           MVB we may have two channels */
        if (ctrl & 8) {
                if (chans == 2) {
                        legacy_probe_add(0x1F0, 14, OPTI46X, 0);
                        legacy_probe_add(0x170, 15, OPTI46X, 0);
                }
                if (ctrl & 4)
                        legacy_probe_add(0x170, 15, OPTI46X, 0);
                else
                        legacy_probe_add(0x1F0, 14, OPTI46X, 0);
        } else
                legacy_probe_add(0x1F0, 14, OPTI46X, 0);
}

static __init void qdi65_identify_port(u8 r, u8 res, unsigned long port)
{
        static const unsigned long ide_port[2] = { 0x170, 0x1F0 };
        /* Check card type */
        if ((r & 0xF0) == 0xC0) {
                /* QD6500: single channel */
                if (r & 8)
                        /* Disabled ? */
                        return;
                legacy_probe_add(ide_port[r & 0x01], 14 + (r & 0x01),
                                                                QDI6500, port);
        }
        if (((r & 0xF0) == 0xA0) || (r & 0xF0) == 0x50) {
                /* QD6580: dual channel */
                if (!request_region(port + 2 , 2, "pata_qdi")) {
                        release_region(port, 2);
                        return;
                }
                res = inb(port + 3);
                /* Single channel mode ? */
                if (res & 1)
                        legacy_probe_add(ide_port[r & 0x01], 14 + (r & 0x01),
                                                                QDI6580, port);
                else { /* Dual channel mode */
                        legacy_probe_add(0x1F0, 14, QDI6580DP, port);
                        /* port + 0x02, r & 0x04 */
                        legacy_probe_add(0x170, 15, QDI6580DP, port + 2);
                }
                release_region(port + 2, 2);
        }
}

static __init void probe_qdi_vlb(void)
{
        unsigned long flags;
        static const unsigned long qd_port[2] = { 0x30, 0xB0 };
        int i;

        /*
         *      Check each possible QD65xx base address
         */

        for (i = 0; i < 2; i++) {
                unsigned long port = qd_port[i];
                u8 r, res;


                if (request_region(port, 2, "pata_qdi")) {
                        /* Check for a card */
                        local_irq_save(flags);
                        /* I have no h/w that needs this delay but it
                           is present in the historic code */
                        r = inb(port);
                        udelay(1);
                        outb(0x19, port);
                        udelay(1);
                        res = inb(port);
                        udelay(1);
                        outb(r, port);
                        udelay(1);
                        local_irq_restore(flags);

                        /* Fail */
                        if (res == 0x19) {
                                release_region(port, 2);
                                continue;
                        }
                        /* Passes the presence test */
                        r = inb(port + 1);
                        udelay(1);
                        /* Check port agrees with port set */
                        if ((r & 2) >> 1 == i)
                                qdi65_identify_port(r, res, port);
                        release_region(port, 2);
                }
        }
}

/**
 *      legacy_init             -       attach legacy interfaces
 *
 *      Attach legacy IDE interfaces by scanning the usual IRQ/port suspects.
 *      Right now we do not scan the ide0 and ide1 address but should do so
 *      for non PCI systems or systems with no PCI IDE legacy mode devices.
 *      If you fix that note there are special cases to consider like VLB
 *      drivers and CS5510/20.
 */

static __init int legacy_init(void)
{
        int i;
        int ct = 0;
        int primary = 0;
        int secondary = 0;
        int pci_present = 0;
        struct legacy_probe *pl = &probe_list[0];
        int slot = 0;

        struct pci_dev *p = NULL;

        for_each_pci_dev(p) {
                int r;
                /* Check for any overlap of the system ATA mappings. Native
                   mode controllers stuck on these addresses or some devices
                   in 'raid' mode won't be found by the storage class test */
                for (r = 0; r < 6; r++) {
                        if (pci_resource_start(p, r) == 0x1f0)
                                primary = 1;
                        if (pci_resource_start(p, r) == 0x170)
                                secondary = 1;
                }
                /* Check for special cases */
                legacy_check_special_cases(p, &primary, &secondary);

                /* If PCI bus is present then don't probe for tertiary
                   legacy ports */
                pci_present = 1;
        }

        if (winbond == 1)
                winbond = 0x130;        /* Default port, alt is 1B0 */

        if (primary == 0 || all)
                legacy_probe_add(0x1F0, 14, UNKNOWN, 0);
        if (secondary == 0 || all)
                legacy_probe_add(0x170, 15, UNKNOWN, 0);

        if (probe_all || !pci_present) {
                /* ISA/VLB extra ports */
                legacy_probe_add(0x1E8, 11, UNKNOWN, 0);
                legacy_probe_add(0x168, 10, UNKNOWN, 0);
                legacy_probe_add(0x1E0, 8, UNKNOWN, 0);
                legacy_probe_add(0x160, 12, UNKNOWN, 0);
        }

        if (opti82c46x)
                probe_opti_vlb();
        if (qdi)
                probe_qdi_vlb();

        for (i = 0; i < NR_HOST; i++, pl++) {
                if (pl->port == 0)
                        continue;
                if (pl->type == UNKNOWN)
                        pl->type = probe_chip_type(pl);
                pl->slot = slot++;
                if (legacy_init_one(pl) == 0)
                        ct++;
        }
        if (ct != 0)
                return 0;
        return -ENODEV;
}

static __exit void legacy_exit(void)
{
        int i;

        for (i = 0; i < nr_legacy_host; i++) {
                struct legacy_data *ld = &legacy_data[i];
                ata_host_detach(legacy_host[i]);
                platform_device_unregister(ld->platform_dev);
        }
}

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for legacy ATA");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);

module_param(probe_all, int, 0);
module_param(autospeed, int, 0);
module_param(ht6560a, int, 0);
module_param(ht6560b, int, 0);
module_param(opti82c611a, int, 0);
module_param(opti82c46x, int, 0);
module_param(qdi, int, 0);
module_param(pio_mask, int, 0);
module_param(iordy_mask, int, 0);

module_init(legacy_init);
module_exit(legacy_exit);