Btrfs: lower the bar for chunk allocation

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / ata / pata_scc.c

/*
 * Support for IDE interfaces on Celleb platform
 *
 * (C) Copyright 2006 TOSHIBA CORPORATION
 *
 * This code is based on drivers/ata/ata_piix.c:
 *  Copyright 2003-2005 Red Hat Inc
 *  Copyright 2003-2005 Jeff Garzik
 *  Copyright (C) 1998-1999 Andrzej Krzysztofowicz, Author and Maintainer
 *  Copyright (C) 1998-2000 Andre Hedrick <andre@linux-ide.org>
 *  Copyright (C) 2003 Red Hat Inc
 *
 * and drivers/ata/ahci.c:
 *  Copyright 2004-2005 Red Hat, Inc.
 *
 * and drivers/ata/libata-core.c:
 *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
 *  Copyright 2003-2004 Jeff Garzik
 *
 * 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 of the License, 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; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#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 <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>

#define DRV_NAME                "pata_scc"
#define DRV_VERSION             "0.3"

#define PCI_DEVICE_ID_TOSHIBA_SCC_ATA           0x01b4

/* PCI BARs */
#define SCC_CTRL_BAR            0
#define SCC_BMID_BAR            1

/* offset of CTRL registers */
#define SCC_CTL_PIOSHT          0x000
#define SCC_CTL_PIOCT           0x004
#define SCC_CTL_MDMACT          0x008
#define SCC_CTL_MCRCST          0x00C
#define SCC_CTL_SDMACT          0x010
#define SCC_CTL_SCRCST          0x014
#define SCC_CTL_UDENVT          0x018
#define SCC_CTL_TDVHSEL         0x020
#define SCC_CTL_MODEREG         0x024
#define SCC_CTL_ECMODE          0xF00
#define SCC_CTL_MAEA0           0xF50
#define SCC_CTL_MAEC0           0xF54
#define SCC_CTL_CCKCTRL         0xFF0

/* offset of BMID registers */
#define SCC_DMA_CMD             0x000
#define SCC_DMA_STATUS          0x004
#define SCC_DMA_TABLE_OFS       0x008
#define SCC_DMA_INTMASK         0x010
#define SCC_DMA_INTST           0x014
#define SCC_DMA_PTERADD         0x018
#define SCC_REG_CMD_ADDR        0x020
#define SCC_REG_DATA            0x000
#define SCC_REG_ERR             0x004
#define SCC_REG_FEATURE         0x004
#define SCC_REG_NSECT           0x008
#define SCC_REG_LBAL            0x00C
#define SCC_REG_LBAM            0x010
#define SCC_REG_LBAH            0x014
#define SCC_REG_DEVICE          0x018
#define SCC_REG_STATUS          0x01C
#define SCC_REG_CMD             0x01C
#define SCC_REG_ALTSTATUS       0x020

/* register value */
#define TDVHSEL_MASTER          0x00000001
#define TDVHSEL_SLAVE           0x00000004

#define MODE_JCUSFEN            0x00000080

#define ECMODE_VALUE            0x01

#define CCKCTRL_ATARESET        0x00040000
#define CCKCTRL_BUFCNT          0x00020000
#define CCKCTRL_CRST            0x00010000
#define CCKCTRL_OCLKEN          0x00000100
#define CCKCTRL_ATACLKOEN       0x00000002
#define CCKCTRL_LCLKEN          0x00000001

#define QCHCD_IOS_SS            0x00000001

#define QCHSD_STPDIAG           0x00020000

#define INTMASK_MSK             0xD1000012
#define INTSTS_SERROR           0x80000000
#define INTSTS_PRERR            0x40000000
#define INTSTS_RERR             0x10000000
#define INTSTS_ICERR            0x01000000
#define INTSTS_BMSINT           0x00000010
#define INTSTS_BMHE             0x00000008
#define INTSTS_IOIRQS           0x00000004
#define INTSTS_INTRQ            0x00000002
#define INTSTS_ACTEINT          0x00000001


/* PIO transfer mode table */
/* JCHST */
static const unsigned long JCHSTtbl[2][7] = {
        {0x0E, 0x05, 0x02, 0x03, 0x02, 0x00, 0x00},     /* 100MHz */
        {0x13, 0x07, 0x04, 0x04, 0x03, 0x00, 0x00}      /* 133MHz */
};

/* JCHHT */
static const unsigned long JCHHTtbl[2][7] = {
        {0x0E, 0x02, 0x02, 0x02, 0x02, 0x00, 0x00},     /* 100MHz */
        {0x13, 0x03, 0x03, 0x03, 0x03, 0x00, 0x00}      /* 133MHz */
};

/* JCHCT */
static const unsigned long JCHCTtbl[2][7] = {
        {0x1D, 0x1D, 0x1C, 0x0B, 0x06, 0x00, 0x00},     /* 100MHz */
        {0x27, 0x26, 0x26, 0x0E, 0x09, 0x00, 0x00}      /* 133MHz */
};

/* DMA transfer mode  table */
/* JCHDCTM/JCHDCTS */
static const unsigned long JCHDCTxtbl[2][7] = {
        {0x0A, 0x06, 0x04, 0x03, 0x01, 0x00, 0x00},     /* 100MHz */
        {0x0E, 0x09, 0x06, 0x04, 0x02, 0x01, 0x00}      /* 133MHz */
};

/* JCSTWTM/JCSTWTS  */
static const unsigned long JCSTWTxtbl[2][7] = {
        {0x06, 0x04, 0x03, 0x02, 0x02, 0x02, 0x00},     /* 100MHz */
        {0x09, 0x06, 0x04, 0x02, 0x02, 0x02, 0x02}      /* 133MHz */
};

/* JCTSS */
static const unsigned long JCTSStbl[2][7] = {
        {0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x00},     /* 100MHz */
        {0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05}      /* 133MHz */
};

/* JCENVT */
static const unsigned long JCENVTtbl[2][7] = {
        {0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x00},     /* 100MHz */
        {0x02, 0x02, 0x02, 0x02, 0x02, 0x02, 0x02}      /* 133MHz */
};

/* JCACTSELS/JCACTSELM */
static const unsigned long JCACTSELtbl[2][7] = {
        {0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x00},     /* 100MHz */
        {0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}      /* 133MHz */
};

static const struct pci_device_id scc_pci_tbl[] = {
        { PCI_VDEVICE(TOSHIBA_2, PCI_DEVICE_ID_TOSHIBA_SCC_ATA), 0},
        { }     /* terminate list */
};

/**
 *      scc_set_piomode - Initialize host controller PATA PIO timings
 *      @ap: Port whose timings we are configuring
 *      @adev: um
 *
 *      Set PIO mode for device.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void scc_set_piomode (struct ata_port *ap, struct ata_device *adev)
{
        unsigned int pio = adev->pio_mode - XFER_PIO_0;
        void __iomem *ctrl_base = ap->host->iomap[SCC_CTRL_BAR];
        void __iomem *cckctrl_port = ctrl_base + SCC_CTL_CCKCTRL;
        void __iomem *piosht_port = ctrl_base + SCC_CTL_PIOSHT;
        void __iomem *pioct_port = ctrl_base + SCC_CTL_PIOCT;
        unsigned long reg;
        int offset;

        reg = in_be32(cckctrl_port);
        if (reg & CCKCTRL_ATACLKOEN)
                offset = 1;     /* 133MHz */
        else
                offset = 0;     /* 100MHz */

        reg = JCHSTtbl[offset][pio] << 16 | JCHHTtbl[offset][pio];
        out_be32(piosht_port, reg);
        reg = JCHCTtbl[offset][pio];
        out_be32(pioct_port, reg);
}

/**
 *      scc_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: um
 *
 *      Set UDMA mode for device.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void scc_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
        unsigned int udma = adev->dma_mode;
        unsigned int is_slave = (adev->devno != 0);
        u8 speed = udma;
        void __iomem *ctrl_base = ap->host->iomap[SCC_CTRL_BAR];
        void __iomem *cckctrl_port = ctrl_base + SCC_CTL_CCKCTRL;
        void __iomem *mdmact_port = ctrl_base + SCC_CTL_MDMACT;
        void __iomem *mcrcst_port = ctrl_base + SCC_CTL_MCRCST;
        void __iomem *sdmact_port = ctrl_base + SCC_CTL_SDMACT;
        void __iomem *scrcst_port = ctrl_base + SCC_CTL_SCRCST;
        void __iomem *udenvt_port = ctrl_base + SCC_CTL_UDENVT;
        void __iomem *tdvhsel_port = ctrl_base + SCC_CTL_TDVHSEL;
        int offset, idx;

        if (in_be32(cckctrl_port) & CCKCTRL_ATACLKOEN)
                offset = 1;     /* 133MHz */
        else
                offset = 0;     /* 100MHz */

        if (speed >= XFER_UDMA_0)
                idx = speed - XFER_UDMA_0;
        else
                return;

        if (is_slave) {
                out_be32(sdmact_port, JCHDCTxtbl[offset][idx]);
                out_be32(scrcst_port, JCSTWTxtbl[offset][idx]);
                out_be32(tdvhsel_port,
                         (in_be32(tdvhsel_port) & ~TDVHSEL_SLAVE) | (JCACTSELtbl[offset][idx] << 2));
        } else {
                out_be32(mdmact_port, JCHDCTxtbl[offset][idx]);
                out_be32(mcrcst_port, JCSTWTxtbl[offset][idx]);
                out_be32(tdvhsel_port,
                         (in_be32(tdvhsel_port) & ~TDVHSEL_MASTER) | JCACTSELtbl[offset][idx]);
        }
        out_be32(udenvt_port,
                 JCTSStbl[offset][idx] << 16 | JCENVTtbl[offset][idx]);
}

unsigned long scc_mode_filter(struct ata_device *adev, unsigned long mask)
{
        /* errata A308 workaround: limit ATAPI UDMA mode to UDMA4 */
        if (adev->class == ATA_DEV_ATAPI &&
            (mask & (0xE0 << ATA_SHIFT_UDMA))) {
                printk(KERN_INFO "%s: limit ATAPI UDMA to UDMA4\n", DRV_NAME);
                mask &= ~(0xE0 << ATA_SHIFT_UDMA);
        }
        return mask;
}

/**
 *      scc_tf_load - send taskfile registers to host controller
 *      @ap: Port to which output is sent
 *      @tf: ATA taskfile register set
 *
 *      Note: Original code is ata_sff_tf_load().
 */

static void scc_tf_load (struct ata_port *ap, const struct ata_taskfile *tf)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;
        unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;

        if (tf->ctl != ap->last_ctl) {
                out_be32(ioaddr->ctl_addr, tf->ctl);
                ap->last_ctl = tf->ctl;
                ata_wait_idle(ap);
        }

        if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
                out_be32(ioaddr->feature_addr, tf->hob_feature);
                out_be32(ioaddr->nsect_addr, tf->hob_nsect);
                out_be32(ioaddr->lbal_addr, tf->hob_lbal);
                out_be32(ioaddr->lbam_addr, tf->hob_lbam);
                out_be32(ioaddr->lbah_addr, tf->hob_lbah);
                VPRINTK("hob: feat 0x%X nsect 0x%X, lba 0x%X 0x%X 0x%X\n",
                        tf->hob_feature,
                        tf->hob_nsect,
                        tf->hob_lbal,
                        tf->hob_lbam,
                        tf->hob_lbah);
        }

        if (is_addr) {
                out_be32(ioaddr->feature_addr, tf->feature);
                out_be32(ioaddr->nsect_addr, tf->nsect);
                out_be32(ioaddr->lbal_addr, tf->lbal);
                out_be32(ioaddr->lbam_addr, tf->lbam);
                out_be32(ioaddr->lbah_addr, tf->lbah);
                VPRINTK("feat 0x%X nsect 0x%X lba 0x%X 0x%X 0x%X\n",
                        tf->feature,
                        tf->nsect,
                        tf->lbal,
                        tf->lbam,
                        tf->lbah);
        }

        if (tf->flags & ATA_TFLAG_DEVICE) {
                out_be32(ioaddr->device_addr, tf->device);
                VPRINTK("device 0x%X\n", tf->device);
        }

        ata_wait_idle(ap);
}

/**
 *      scc_check_status - Read device status reg & clear interrupt
 *      @ap: port where the device is
 *
 *      Note: Original code is ata_check_status().
 */

static u8 scc_check_status (struct ata_port *ap)
{
        return in_be32(ap->ioaddr.status_addr);
}

/**
 *      scc_tf_read - input device's ATA taskfile shadow registers
 *      @ap: Port from which input is read
 *      @tf: ATA taskfile register set for storing input
 *
 *      Note: Original code is ata_sff_tf_read().
 */

static void scc_tf_read (struct ata_port *ap, struct ata_taskfile *tf)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;

        tf->command = scc_check_status(ap);
        tf->feature = in_be32(ioaddr->error_addr);
        tf->nsect = in_be32(ioaddr->nsect_addr);
        tf->lbal = in_be32(ioaddr->lbal_addr);
        tf->lbam = in_be32(ioaddr->lbam_addr);
        tf->lbah = in_be32(ioaddr->lbah_addr);
        tf->device = in_be32(ioaddr->device_addr);

        if (tf->flags & ATA_TFLAG_LBA48) {
                out_be32(ioaddr->ctl_addr, tf->ctl | ATA_HOB);
                tf->hob_feature = in_be32(ioaddr->error_addr);
                tf->hob_nsect = in_be32(ioaddr->nsect_addr);
                tf->hob_lbal = in_be32(ioaddr->lbal_addr);
                tf->hob_lbam = in_be32(ioaddr->lbam_addr);
                tf->hob_lbah = in_be32(ioaddr->lbah_addr);
                out_be32(ioaddr->ctl_addr, tf->ctl);
                ap->last_ctl = tf->ctl;
        }
}

/**
 *      scc_exec_command - issue ATA command to host controller
 *      @ap: port to which command is being issued
 *      @tf: ATA taskfile register set
 *
 *      Note: Original code is ata_sff_exec_command().
 */

static void scc_exec_command (struct ata_port *ap,
                              const struct ata_taskfile *tf)
{
        DPRINTK("ata%u: cmd 0x%X\n", ap->print_id, tf->command);

        out_be32(ap->ioaddr.command_addr, tf->command);
        ata_sff_pause(ap);
}

/**
 *      scc_check_altstatus - Read device alternate status reg
 *      @ap: port where the device is
 */

static u8 scc_check_altstatus (struct ata_port *ap)
{
        return in_be32(ap->ioaddr.altstatus_addr);
}

/**
 *      scc_dev_select - Select device 0/1 on ATA bus
 *      @ap: ATA channel to manipulate
 *      @device: ATA device (numbered from zero) to select
 *
 *      Note: Original code is ata_sff_dev_select().
 */

static void scc_dev_select (struct ata_port *ap, unsigned int device)
{
        u8 tmp;

        if (device == 0)
                tmp = ATA_DEVICE_OBS;
        else
                tmp = ATA_DEVICE_OBS | ATA_DEV1;

        out_be32(ap->ioaddr.device_addr, tmp);
        ata_sff_pause(ap);
}

/**
 *      scc_set_devctl - Write device control reg
 *      @ap: port where the device is
 *      @ctl: value to write
 */

static void scc_set_devctl(struct ata_port *ap, u8 ctl)
{
        out_be32(ap->ioaddr.ctl_addr, ctl);
}

/**
 *      scc_bmdma_setup - Set up PCI IDE BMDMA transaction
 *      @qc: Info associated with this ATA transaction.
 *
 *      Note: Original code is ata_bmdma_setup().
 */

static void scc_bmdma_setup (struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
        u8 dmactl;
        void __iomem *mmio = ap->ioaddr.bmdma_addr;

        /* load PRD table addr */
        out_be32(mmio + SCC_DMA_TABLE_OFS, ap->bmdma_prd_dma);

        /* specify data direction, triple-check start bit is clear */
        dmactl = in_be32(mmio + SCC_DMA_CMD);
        dmactl &= ~(ATA_DMA_WR | ATA_DMA_START);
        if (!rw)
                dmactl |= ATA_DMA_WR;
        out_be32(mmio + SCC_DMA_CMD, dmactl);

        /* issue r/w command */
        ap->ops->sff_exec_command(ap, &qc->tf);
}

/**
 *      scc_bmdma_start - Start a PCI IDE BMDMA transaction
 *      @qc: Info associated with this ATA transaction.
 *
 *      Note: Original code is ata_bmdma_start().
 */

static void scc_bmdma_start (struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        u8 dmactl;
        void __iomem *mmio = ap->ioaddr.bmdma_addr;

        /* start host DMA transaction */
        dmactl = in_be32(mmio + SCC_DMA_CMD);
        out_be32(mmio + SCC_DMA_CMD, dmactl | ATA_DMA_START);
}

/**
 *      scc_devchk - PATA device presence detection
 *      @ap: ATA channel to examine
 *      @device: Device to examine (starting at zero)
 *
 *      Note: Original code is ata_devchk().
 */

static unsigned int scc_devchk (struct ata_port *ap,
                                unsigned int device)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;
        u8 nsect, lbal;

        ap->ops->sff_dev_select(ap, device);

        out_be32(ioaddr->nsect_addr, 0x55);
        out_be32(ioaddr->lbal_addr, 0xaa);

        out_be32(ioaddr->nsect_addr, 0xaa);
        out_be32(ioaddr->lbal_addr, 0x55);

        out_be32(ioaddr->nsect_addr, 0x55);
        out_be32(ioaddr->lbal_addr, 0xaa);

        nsect = in_be32(ioaddr->nsect_addr);
        lbal = in_be32(ioaddr->lbal_addr);

        if ((nsect == 0x55) && (lbal == 0xaa))
                return 1;       /* we found a device */

        return 0;               /* nothing found */
}

/**
 *      scc_wait_after_reset - wait for devices to become ready after reset
 *
 *      Note: Original code is ata_sff_wait_after_reset
 */

static int scc_wait_after_reset(struct ata_link *link, unsigned int devmask,
                                unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        struct ata_ioports *ioaddr = &ap->ioaddr;
        unsigned int dev0 = devmask & (1 << 0);
        unsigned int dev1 = devmask & (1 << 1);
        int rc, ret = 0;

        /* Spec mandates ">= 2ms" before checking status.  We wait
         * 150ms, because that was the magic delay used for ATAPI
         * devices in Hale Landis's ATADRVR, for the period of time
         * between when the ATA command register is written, and then
         * status is checked.  Because waiting for "a while" before
         * checking status is fine, post SRST, we perform this magic
         * delay here as well.
         *
         * Old drivers/ide uses the 2mS rule and then waits for ready.
         */
        ata_msleep(ap, 150);

        /* always check readiness of the master device */
        rc = ata_sff_wait_ready(link, deadline);
        /* -ENODEV means the odd clown forgot the D7 pulldown resistor
         * and TF status is 0xff, bail out on it too.
         */
        if (rc)
                return rc;

        /* if device 1 was found in ata_devchk, wait for register
         * access briefly, then wait for BSY to clear.
         */
        if (dev1) {
                int i;

                ap->ops->sff_dev_select(ap, 1);

                /* Wait for register access.  Some ATAPI devices fail
                 * to set nsect/lbal after reset, so don't waste too
                 * much time on it.  We're gonna wait for !BSY anyway.
                 */
                for (i = 0; i < 2; i++) {
                        u8 nsect, lbal;

                        nsect = in_be32(ioaddr->nsect_addr);
                        lbal = in_be32(ioaddr->lbal_addr);
                        if ((nsect == 1) && (lbal == 1))
                                break;
                        ata_msleep(ap, 50);     /* give drive a breather */
                }

                rc = ata_sff_wait_ready(link, deadline);
                if (rc) {
                        if (rc != -ENODEV)
                                return rc;
                        ret = rc;
                }
        }

        /* is all this really necessary? */
        ap->ops->sff_dev_select(ap, 0);
        if (dev1)
                ap->ops->sff_dev_select(ap, 1);
        if (dev0)
                ap->ops->sff_dev_select(ap, 0);

        return ret;
}

/**
 *      scc_bus_softreset - PATA device software reset
 *
 *      Note: Original code is ata_bus_softreset().
 */

static unsigned int scc_bus_softreset(struct ata_port *ap, unsigned int devmask,
                                      unsigned long deadline)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;

        DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);

        /* software reset.  causes dev0 to be selected */
        out_be32(ioaddr->ctl_addr, ap->ctl);
        udelay(20);
        out_be32(ioaddr->ctl_addr, ap->ctl | ATA_SRST);
        udelay(20);
        out_be32(ioaddr->ctl_addr, ap->ctl);

        scc_wait_after_reset(&ap->link, devmask, deadline);

        return 0;
}

/**
 *      scc_softreset - reset host port via ATA SRST
 *      @ap: port to reset
 *      @classes: resulting classes of attached devices
 *      @deadline: deadline jiffies for the operation
 *
 *      Note: Original code is ata_sff_softreset().
 */

static int scc_softreset(struct ata_link *link, unsigned int *classes,
                         unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
        unsigned int devmask = 0, err_mask;
        u8 err;

        DPRINTK("ENTER\n");

        /* determine if device 0/1 are present */
        if (scc_devchk(ap, 0))
                devmask |= (1 << 0);
        if (slave_possible && scc_devchk(ap, 1))
                devmask |= (1 << 1);

        /* select device 0 again */
        ap->ops->sff_dev_select(ap, 0);

        /* issue bus reset */
        DPRINTK("about to softreset, devmask=%x\n", devmask);
        err_mask = scc_bus_softreset(ap, devmask, deadline);
        if (err_mask) {
                ata_port_err(ap, "SRST failed (err_mask=0x%x)\n", err_mask);
                return -EIO;
        }

        /* determine by signature whether we have ATA or ATAPI devices */
        classes[0] = ata_sff_dev_classify(&ap->link.device[0],
                                          devmask & (1 << 0), &err);
        if (slave_possible && err != 0x81)
                classes[1] = ata_sff_dev_classify(&ap->link.device[1],
                                                  devmask & (1 << 1), &err);

        DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
        return 0;
}

/**
 *      scc_bmdma_stop - Stop PCI IDE BMDMA transfer
 *      @qc: Command we are ending DMA for
 */

static void scc_bmdma_stop (struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        void __iomem *ctrl_base = ap->host->iomap[SCC_CTRL_BAR];
        void __iomem *bmid_base = ap->host->iomap[SCC_BMID_BAR];
        u32 reg;

        while (1) {
                reg = in_be32(bmid_base + SCC_DMA_INTST);

                if (reg & INTSTS_SERROR) {
                        printk(KERN_WARNING "%s: SERROR\n", DRV_NAME);
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_SERROR|INTSTS_BMSINT);
                        out_be32(bmid_base + SCC_DMA_CMD,
                                 in_be32(bmid_base + SCC_DMA_CMD) & ~ATA_DMA_START);
                        continue;
                }

                if (reg & INTSTS_PRERR) {
                        u32 maea0, maec0;
                        maea0 = in_be32(ctrl_base + SCC_CTL_MAEA0);
                        maec0 = in_be32(ctrl_base + SCC_CTL_MAEC0);
                        printk(KERN_WARNING "%s: PRERR [addr:%x cmd:%x]\n", DRV_NAME, maea0, maec0);
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_PRERR|INTSTS_BMSINT);
                        out_be32(bmid_base + SCC_DMA_CMD,
                                 in_be32(bmid_base + SCC_DMA_CMD) & ~ATA_DMA_START);
                        continue;
                }

                if (reg & INTSTS_RERR) {
                        printk(KERN_WARNING "%s: Response Error\n", DRV_NAME);
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_RERR|INTSTS_BMSINT);
                        out_be32(bmid_base + SCC_DMA_CMD,
                                 in_be32(bmid_base + SCC_DMA_CMD) & ~ATA_DMA_START);
                        continue;
                }

                if (reg & INTSTS_ICERR) {
                        out_be32(bmid_base + SCC_DMA_CMD,
                                 in_be32(bmid_base + SCC_DMA_CMD) & ~ATA_DMA_START);
                        printk(KERN_WARNING "%s: Illegal Configuration\n", DRV_NAME);
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_ICERR|INTSTS_BMSINT);
                        continue;
                }

                if (reg & INTSTS_BMSINT) {
                        unsigned int classes;
                        unsigned long deadline = ata_deadline(jiffies, ATA_TMOUT_BOOT);
                        printk(KERN_WARNING "%s: Internal Bus Error\n", DRV_NAME);
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_BMSINT);
                        /* TBD: SW reset */
                        scc_softreset(&ap->link, &classes, deadline);
                        continue;
                }

                if (reg & INTSTS_BMHE) {
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_BMHE);
                        continue;
                }

                if (reg & INTSTS_ACTEINT) {
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_ACTEINT);
                        continue;
                }

                if (reg & INTSTS_IOIRQS) {
                        out_be32(bmid_base + SCC_DMA_INTST, INTSTS_IOIRQS);
                        continue;
                }
                break;
        }

        /* clear start/stop bit */
        out_be32(bmid_base + SCC_DMA_CMD,
                 in_be32(bmid_base + SCC_DMA_CMD) & ~ATA_DMA_START);

        /* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
        ata_sff_dma_pause(ap);  /* dummy read */
}

/**
 *      scc_bmdma_status - Read PCI IDE BMDMA status
 *      @ap: Port associated with this ATA transaction.
 */

static u8 scc_bmdma_status (struct ata_port *ap)
{
        void __iomem *mmio = ap->ioaddr.bmdma_addr;
        u8 host_stat = in_be32(mmio + SCC_DMA_STATUS);
        u32 int_status = in_be32(mmio + SCC_DMA_INTST);
        struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->link.active_tag);
        static int retry = 0;

        /* return if IOS_SS is cleared */
        if (!(in_be32(mmio + SCC_DMA_CMD) & ATA_DMA_START))
                return host_stat;

        /* errata A252,A308 workaround: Step4 */
        if ((scc_check_altstatus(ap) & ATA_ERR)
                                        && (int_status & INTSTS_INTRQ))
                return (host_stat | ATA_DMA_INTR);

        /* errata A308 workaround Step5 */
        if (int_status & INTSTS_IOIRQS) {
                host_stat |= ATA_DMA_INTR;

                /* We don't check ATAPI DMA because it is limited to UDMA4 */
                if ((qc->tf.protocol == ATA_PROT_DMA &&
                     qc->dev->xfer_mode > XFER_UDMA_4)) {
                        if (!(int_status & INTSTS_ACTEINT)) {
                                printk(KERN_WARNING "ata%u: operation failed (transfer data loss)\n",
                                       ap->print_id);
                                host_stat |= ATA_DMA_ERR;
                                if (retry++)
                                        ap->udma_mask &= ~(1 << qc->dev->xfer_mode);
                        } else
                                retry = 0;
                }
        }

        return host_stat;
}

/**
 *      scc_data_xfer - Transfer data by PIO
 *      @dev: device for this I/O
 *      @buf: data buffer
 *      @buflen: buffer length
 *      @rw: read/write
 *
 *      Note: Original code is ata_sff_data_xfer().
 */

static unsigned int scc_data_xfer (struct ata_device *dev, unsigned char *buf,
                                   unsigned int buflen, int rw)
{
        struct ata_port *ap = dev->link->ap;
        unsigned int words = buflen >> 1;
        unsigned int i;
        __le16 *buf16 = (__le16 *) buf;
        void __iomem *mmio = ap->ioaddr.data_addr;

        /* Transfer multiple of 2 bytes */
        if (rw == READ)
                for (i = 0; i < words; i++)
                        buf16[i] = cpu_to_le16(in_be32(mmio));
        else
                for (i = 0; i < words; i++)
                        out_be32(mmio, le16_to_cpu(buf16[i]));

        /* Transfer trailing 1 byte, if any. */
        if (unlikely(buflen & 0x01)) {
                __le16 align_buf[1] = { 0 };
                unsigned char *trailing_buf = buf + buflen - 1;

                if (rw == READ) {
                        align_buf[0] = cpu_to_le16(in_be32(mmio));
                        memcpy(trailing_buf, align_buf, 1);
                } else {
                        memcpy(align_buf, trailing_buf, 1);
                        out_be32(mmio, le16_to_cpu(align_buf[0]));
                }
                words++;
        }

        return words << 1;
}

/**
 *      scc_postreset - standard postreset callback
 *      @ap: the target ata_port
 *      @classes: classes of attached devices
 *
 *      Note: Original code is ata_sff_postreset().
 */

static void scc_postreset(struct ata_link *link, unsigned int *classes)
{
        struct ata_port *ap = link->ap;

        DPRINTK("ENTER\n");

        /* is double-select really necessary? */
        if (classes[0] != ATA_DEV_NONE)
                ap->ops->sff_dev_select(ap, 1);
        if (classes[1] != ATA_DEV_NONE)
                ap->ops->sff_dev_select(ap, 0);

        /* bail out if no device is present */
        if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
                DPRINTK("EXIT, no device\n");
                return;
        }

        /* set up device control */
        out_be32(ap->ioaddr.ctl_addr, ap->ctl);

        DPRINTK("EXIT\n");
}

/**
 *      scc_irq_clear - Clear PCI IDE BMDMA interrupt.
 *      @ap: Port associated with this ATA transaction.
 *
 *      Note: Original code is ata_bmdma_irq_clear().
 */

static void scc_irq_clear (struct ata_port *ap)
{
        void __iomem *mmio = ap->ioaddr.bmdma_addr;

        if (!mmio)
                return;

        out_be32(mmio + SCC_DMA_STATUS, in_be32(mmio + SCC_DMA_STATUS));
}

/**
 *      scc_port_start - Set port up for dma.
 *      @ap: Port to initialize
 *
 *      Allocate space for PRD table using ata_bmdma_port_start().
 *      Set PRD table address for PTERADD. (PRD Transfer End Read)
 */

static int scc_port_start (struct ata_port *ap)
{
        void __iomem *mmio = ap->ioaddr.bmdma_addr;
        int rc;

        rc = ata_bmdma_port_start(ap);
        if (rc)
                return rc;

        out_be32(mmio + SCC_DMA_PTERADD, ap->bmdma_prd_dma);
        return 0;
}

/**
 *      scc_port_stop - Undo scc_port_start()
 *      @ap: Port to shut down
 *
 *      Reset PTERADD.
 */

static void scc_port_stop (struct ata_port *ap)
{
        void __iomem *mmio = ap->ioaddr.bmdma_addr;

        out_be32(mmio + SCC_DMA_PTERADD, 0);
}

static struct scsi_host_template scc_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
};

static struct ata_port_operations scc_pata_ops = {
        .inherits               = &ata_bmdma_port_ops,

        .set_piomode            = scc_set_piomode,
        .set_dmamode            = scc_set_dmamode,
        .mode_filter            = scc_mode_filter,

        .sff_tf_load            = scc_tf_load,
        .sff_tf_read            = scc_tf_read,
        .sff_exec_command       = scc_exec_command,
        .sff_check_status       = scc_check_status,
        .sff_check_altstatus    = scc_check_altstatus,
        .sff_dev_select         = scc_dev_select,
        .sff_set_devctl         = scc_set_devctl,

        .bmdma_setup            = scc_bmdma_setup,
        .bmdma_start            = scc_bmdma_start,
        .bmdma_stop             = scc_bmdma_stop,
        .bmdma_status           = scc_bmdma_status,
        .sff_data_xfer          = scc_data_xfer,

        .cable_detect           = ata_cable_80wire,
        .softreset              = scc_softreset,
        .postreset              = scc_postreset,

        .sff_irq_clear          = scc_irq_clear,

        .port_start             = scc_port_start,
        .port_stop              = scc_port_stop,
};

static struct ata_port_info scc_port_info[] = {
        {
                .flags          = ATA_FLAG_SLAVE_POSS,
                .pio_mask       = ATA_PIO4,
                /* No MWDMA */
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &scc_pata_ops,
        },
};

/**
 *      scc_reset_controller - initialize SCC PATA controller.
 */

static int scc_reset_controller(struct ata_host *host)
{
        void __iomem *ctrl_base = host->iomap[SCC_CTRL_BAR];
        void __iomem *bmid_base = host->iomap[SCC_BMID_BAR];
        void __iomem *cckctrl_port = ctrl_base + SCC_CTL_CCKCTRL;
        void __iomem *mode_port = ctrl_base + SCC_CTL_MODEREG;
        void __iomem *ecmode_port = ctrl_base + SCC_CTL_ECMODE;
        void __iomem *intmask_port = bmid_base + SCC_DMA_INTMASK;
        void __iomem *dmastatus_port = bmid_base + SCC_DMA_STATUS;
        u32 reg = 0;

        out_be32(cckctrl_port, reg);
        reg |= CCKCTRL_ATACLKOEN;
        out_be32(cckctrl_port, reg);
        reg |= CCKCTRL_LCLKEN | CCKCTRL_OCLKEN;
        out_be32(cckctrl_port, reg);
        reg |= CCKCTRL_CRST;
        out_be32(cckctrl_port, reg);

        for (;;) {
                reg = in_be32(cckctrl_port);
                if (reg & CCKCTRL_CRST)
                        break;
                udelay(5000);
        }

        reg |= CCKCTRL_ATARESET;
        out_be32(cckctrl_port, reg);
        out_be32(ecmode_port, ECMODE_VALUE);
        out_be32(mode_port, MODE_JCUSFEN);
        out_be32(intmask_port, INTMASK_MSK);

        if (in_be32(dmastatus_port) & QCHSD_STPDIAG) {
                printk(KERN_WARNING "%s: failed to detect 80c cable. (PDIAG# is high)\n", DRV_NAME);
                return -EIO;
        }

        return 0;
}

/**
 *      scc_setup_ports - initialize ioaddr with SCC PATA port offsets.
 *      @ioaddr: IO address structure to be initialized
 *      @base: base address of BMID region
 */

static void scc_setup_ports (struct ata_ioports *ioaddr, void __iomem *base)
{
        ioaddr->cmd_addr = base + SCC_REG_CMD_ADDR;
        ioaddr->altstatus_addr = ioaddr->cmd_addr + SCC_REG_ALTSTATUS;
        ioaddr->ctl_addr = ioaddr->cmd_addr + SCC_REG_ALTSTATUS;
        ioaddr->bmdma_addr = base;
        ioaddr->data_addr = ioaddr->cmd_addr + SCC_REG_DATA;
        ioaddr->error_addr = ioaddr->cmd_addr + SCC_REG_ERR;
        ioaddr->feature_addr = ioaddr->cmd_addr + SCC_REG_FEATURE;
        ioaddr->nsect_addr = ioaddr->cmd_addr + SCC_REG_NSECT;
        ioaddr->lbal_addr = ioaddr->cmd_addr + SCC_REG_LBAL;
        ioaddr->lbam_addr = ioaddr->cmd_addr + SCC_REG_LBAM;
        ioaddr->lbah_addr = ioaddr->cmd_addr + SCC_REG_LBAH;
        ioaddr->device_addr = ioaddr->cmd_addr + SCC_REG_DEVICE;
        ioaddr->status_addr = ioaddr->cmd_addr + SCC_REG_STATUS;
        ioaddr->command_addr = ioaddr->cmd_addr + SCC_REG_CMD;
}

static int scc_host_init(struct ata_host *host)
{
        struct pci_dev *pdev = to_pci_dev(host->dev);
        int rc;

        rc = scc_reset_controller(host);
        if (rc)
                return rc;

        rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
        if (rc)
                return rc;
        rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
        if (rc)
                return rc;

        scc_setup_ports(&host->ports[0]->ioaddr, host->iomap[SCC_BMID_BAR]);

        pci_set_master(pdev);

        return 0;
}

/**
 *      scc_init_one - Register SCC PATA device with kernel services
 *      @pdev: PCI device to register
 *      @ent: Entry in scc_pci_tbl matching with @pdev
 *
 *      LOCKING:
 *      Inherited from PCI layer (may sleep).
 *
 *      RETURNS:
 *      Zero on success, or -ERRNO value.
 */

static int scc_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
        unsigned int board_idx = (unsigned int) ent->driver_data;
        const struct ata_port_info *ppi[] = { &scc_port_info[board_idx], NULL };
        struct ata_host *host;
        int rc;

        ata_print_version_once(&pdev->dev, DRV_VERSION);

        host = ata_host_alloc_pinfo(&pdev->dev, ppi, 1);
        if (!host)
                return -ENOMEM;

        rc = pcim_enable_device(pdev);
        if (rc)
                return rc;

        rc = pcim_iomap_regions(pdev, (1 << SCC_CTRL_BAR) | (1 << SCC_BMID_BAR), DRV_NAME);
        if (rc == -EBUSY)
                pcim_pin_device(pdev);
        if (rc)
                return rc;
        host->iomap = pcim_iomap_table(pdev);

        ata_port_pbar_desc(host->ports[0], SCC_CTRL_BAR, -1, "ctrl");
        ata_port_pbar_desc(host->ports[0], SCC_BMID_BAR, -1, "bmid");

        rc = scc_host_init(host);
        if (rc)
                return rc;

        return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,
                                 IRQF_SHARED, &scc_sht);
}

static struct pci_driver scc_pci_driver = {
        .name                   = DRV_NAME,
        .id_table               = scc_pci_tbl,
        .probe                  = scc_init_one,
        .remove                 = ata_pci_remove_one,
#ifdef CONFIG_PM
        .suspend                = ata_pci_device_suspend,
        .resume                 = ata_pci_device_resume,
#endif
};

static int __init scc_init (void)
{
        int rc;

        DPRINTK("pci_register_driver\n");
        rc = pci_register_driver(&scc_pci_driver);
        if (rc)
                return rc;

        DPRINTK("done\n");
        return 0;
}

static void __exit scc_exit (void)
{
        pci_unregister_driver(&scc_pci_driver);
}

module_init(scc_init);
module_exit(scc_exit);

MODULE_AUTHOR("Toshiba corp");
MODULE_DESCRIPTION("SCSI low-level driver for Toshiba SCC PATA controller");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, scc_pci_tbl);
MODULE_VERSION(DRV_VERSION);