/*
 *    pata_sis.c - SiS ATA driver
 *
 *      (C) 2005 Red Hat
 *      (C) 2007,2009 Bartlomiej Zolnierkiewicz
 *
 *    Based upon linux/drivers/ide/pci/sis5513.c
 * Copyright (C) 1999-2000      Andre Hedrick <andre@linux-ide.org>
 * Copyright (C) 2002           Lionel Bouton <Lionel.Bouton@inet6.fr>, Maintainer
 * Copyright (C) 2003           Vojtech Pavlik <vojtech@suse.cz>
 * SiS Taiwan           : for direct support and hardware.
 * Daniela Engert       : for initial ATA100 advices and numerous others.
 * John Fremlin, Manfred Spraul, Dave Morgan, Peter Kjellerstedt        :
 *                        for checking code correctness, providing patches.
 * Original tests and design on the SiS620 chipset.
 * ATA100 tests and design on the SiS735 chipset.
 * ATA16/33 support from specs
 * ATA133 support for SiS961/962 by L.C. Chang <lcchang@sis.com.tw>
 *
 *
 *      TODO
 *      Check MWDMA on drives that don't support MWDMA speed pio cycles ?
 *      More Testing
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <linux/ata.h>
#include "sis.h"

#define DRV_NAME        "pata_sis"
#define DRV_VERSION     "0.5.2"

struct sis_chipset {
        u16 device;                             /* PCI host ID */
        const struct ata_port_info *info;       /* Info block */
        /* Probably add family, cable detect type etc here to clean
           up code later */
};

struct sis_laptop {
        u16 device;
        u16 subvendor;
        u16 subdevice;
};

static const struct sis_laptop sis_laptop[] = {
        /* devid, subvendor, subdev */
        { 0x5513, 0x1043, 0x1107 },     /* ASUS A6K */
        { 0x5513, 0x1734, 0x105F },     /* FSC Amilo A1630 */
        { 0x5513, 0x1071, 0x8640 },     /* EasyNote K5305 */
        /* end marker */
        { 0, }
};

static int sis_short_ata40(struct pci_dev *dev)
{
        const struct sis_laptop *lap = &sis_laptop[0];

        while (lap->device) {
                if (lap->device == dev->device &&
                    lap->subvendor == dev->subsystem_vendor &&
                    lap->subdevice == dev->subsystem_device)
                        return 1;
                lap++;
        }

        return 0;
}

/**
 *      sis_old_port_base - return PCI configuration base for dev
 *      @adev: device
 *
 *      Returns the base of the PCI configuration registers for this port
 *      number.
 */

static int sis_old_port_base(struct ata_device *adev)
{
        return 0x40 + (4 * adev->link->ap->port_no) + (2 * adev->devno);
}

/**
 *      sis_port_base - return PCI configuration base for dev
 *      @adev: device
 *
 *      Returns the base of the PCI configuration registers for this port
 *      number.
 */

static int sis_port_base(struct ata_device *adev)
{
        struct ata_port *ap = adev->link->ap;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int port = 0x40;
        u32 reg54;

        /* If bit 30 is set then the registers are mapped at 0x70 not 0x40 */
        pci_read_config_dword(pdev, 0x54, &reg54);
        if (reg54 & 0x40000000)
                port = 0x70;

        return port + (8 * ap->port_no) + (4 * adev->devno);
}

/**
 *      sis_133_cable_detect - check for 40/80 pin
 *      @ap: Port
 *      @deadline: deadline jiffies for the operation
 *
 *      Perform cable detection for the later UDMA133 capable
 *      SiS chipset.
 */

static int sis_133_cable_detect(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u16 tmp;

        /* The top bit of this register is the cable detect bit */
        pci_read_config_word(pdev, 0x50 + 2 * ap->port_no, &tmp);
        if ((tmp & 0x8000) && !sis_short_ata40(pdev))
                return ATA_CBL_PATA40;
        return ATA_CBL_PATA80;
}

/**
 *      sis_66_cable_detect - check for 40/80 pin
 *      @ap: Port
 *
 *      Perform cable detection on the UDMA66, UDMA100 and early UDMA133
 *      SiS IDE controllers.
 */

static int sis_66_cable_detect(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u8 tmp;

        /* Older chips keep cable detect in bits 4/5 of reg 0x48 */
        pci_read_config_byte(pdev, 0x48, &tmp);
        tmp >>= ap->port_no;
        if ((tmp & 0x10) && !sis_short_ata40(pdev))
                return ATA_CBL_PATA40;
        return ATA_CBL_PATA80;
}


/**
 *      sis_pre_reset - probe begin
 *      @link: ATA link
 *      @deadline: deadline jiffies for the operation
 *
 *      Set up cable type and use generic probe init
 */

static int sis_pre_reset(struct ata_link *link, unsigned long deadline)
{
        static const struct pci_bits sis_enable_bits[] = {
                { 0x4aU, 1U, 0x02UL, 0x02UL },  /* port 0 */
                { 0x4aU, 1U, 0x04UL, 0x04UL },  /* port 1 */
        };

        struct ata_port *ap = link->ap;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        if (!pci_test_config_bits(pdev, &sis_enable_bits[ap->port_no]))
                return -ENOENT;

        /* Clear the FIFO settings. We can't enable the FIFO until
           we know we are poking at a disk */
        pci_write_config_byte(pdev, 0x4B, 0);
        return ata_sff_prereset(link, deadline);
}


/**
 *      sis_set_fifo - Set RWP fifo bits for this device
 *      @ap: Port
 *      @adev: Device
 *
 *      SIS chipsets implement prefetch/postwrite bits for each device
 *      on both channels. This functionality is not ATAPI compatible and
 *      must be configured according to the class of device present
 */

static void sis_set_fifo(struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u8 fifoctrl;
        u8 mask = 0x11;

        mask <<= (2 * ap->port_no);
        mask <<= adev->devno;

        /* This holds various bits including the FIFO control */
        pci_read_config_byte(pdev, 0x4B, &fifoctrl);
        fifoctrl &= ~mask;

        /* Enable for ATA (disk) only */
        if (adev->class == ATA_DEV_ATA)
                fifoctrl |= mask;
        pci_write_config_byte(pdev, 0x4B, fifoctrl);
}

/**
 *      sis_old_set_piomode - Initialize host controller PATA PIO timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device we are configuring for.
 *
 *      Set PIO mode for device, in host controller PCI config space. This
 *      function handles PIO set up for all chips that are pre ATA100 and
 *      also early ATA100 devices.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_old_set_piomode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int port = sis_old_port_base(adev);
        u8 t1, t2;
        int speed = adev->pio_mode - XFER_PIO_0;

        static const u8 active[]   = { 0x00, 0x07, 0x04, 0x03, 0x01 };
        static const u8 recovery[] = { 0x00, 0x06, 0x04, 0x03, 0x03 };

        sis_set_fifo(ap, adev);

        pci_read_config_byte(pdev, port, &t1);
        pci_read_config_byte(pdev, port + 1, &t2);

        t1 &= ~0x0F;    /* Clear active/recovery timings */
        t2 &= ~0x07;

        t1 |= active[speed];
        t2 |= recovery[speed];

        pci_write_config_byte(pdev, port, t1);
        pci_write_config_byte(pdev, port + 1, t2);
}

/**
 *      sis_100_set_piomode - Initialize host controller PATA PIO timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device we are configuring for.
 *
 *      Set PIO mode for device, in host controller PCI config space. This
 *      function handles PIO set up for ATA100 devices and early ATA133.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_100_set_piomode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int port = sis_old_port_base(adev);
        int speed = adev->pio_mode - XFER_PIO_0;

        static const u8 actrec[] = { 0x00, 0x67, 0x44, 0x33, 0x31 };

        sis_set_fifo(ap, adev);

        pci_write_config_byte(pdev, port, actrec[speed]);
}

/**
 *      sis_133_set_piomode - Initialize host controller PATA PIO timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device we are configuring for.
 *
 *      Set PIO mode for device, in host controller PCI config space. This
 *      function handles PIO set up for the later ATA133 devices.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_133_set_piomode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int port;
        u32 t1;
        int speed = adev->pio_mode - XFER_PIO_0;

        static const u32 timing133[] = {
                0x28269000,     /* Recovery << 24 | Act << 16 | Ini << 12 */
                0x0C266000,
                0x04263000,
                0x0C0A3000,
                0x05093000
        };
        static const u32 timing100[] = {
                0x1E1C6000,     /* Recovery << 24 | Act << 16 | Ini << 12 */
                0x091C4000,
                0x031C2000,
                0x09072000,
                0x04062000
        };

        sis_set_fifo(ap, adev);

        port = sis_port_base(adev);
        pci_read_config_dword(pdev, port, &t1);
        t1 &= 0xC0C00FFF;       /* Mask out timing */

        if (t1 & 0x08)          /* 100 or 133 ? */
                t1 |= timing133[speed];
        else
                t1 |= timing100[speed];
        pci_write_config_byte(pdev, port, t1);
}

/**
 *      sis_old_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device to program
 *
 *      Set UDMA/MWDMA mode for device, in host controller PCI config space.
 *      Handles pre UDMA and UDMA33 devices. Supports MWDMA as well unlike
 *      the old ide/pci driver.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_old_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int speed = adev->dma_mode - XFER_MW_DMA_0;
        int drive_pci = sis_old_port_base(adev);
        u16 timing;

        static const u16 mwdma_bits[] = { 0x008, 0x302, 0x301 };
        static const u16 udma_bits[]  = { 0xE000, 0xC000, 0xA000 };

        pci_read_config_word(pdev, drive_pci, &timing);

        if (adev->dma_mode < XFER_UDMA_0) {
                /* bits 3-0 hold recovery timing bits 8-10 active timing and
                   the higher bits are dependent on the device */
                timing &= ~0x870F;
                timing |= mwdma_bits[speed];
        } else {
                /* Bit 15 is UDMA on/off, bit 13-14 are cycle time */
                speed = adev->dma_mode - XFER_UDMA_0;
                timing &= ~0x6000;
                timing |= udma_bits[speed];
        }
        pci_write_config_word(pdev, drive_pci, timing);
}

/**
 *      sis_66_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device to program
 *
 *      Set UDMA/MWDMA mode for device, in host controller PCI config space.
 *      Handles UDMA66 and early UDMA100 devices. Supports MWDMA as well unlike
 *      the old ide/pci driver.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_66_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int speed = adev->dma_mode - XFER_MW_DMA_0;
        int drive_pci = sis_old_port_base(adev);
        u16 timing;

        /* MWDMA 0-2 and UDMA 0-5 */
        static const u16 mwdma_bits[] = { 0x008, 0x302, 0x301 };
        static const u16 udma_bits[]  = { 0xF000, 0xD000, 0xB000, 0xA000, 0x9000, 0x8000 };

        pci_read_config_word(pdev, drive_pci, &timing);

        if (adev->dma_mode < XFER_UDMA_0) {
                /* bits 3-0 hold recovery timing bits 8-10 active timing and
                   the higher bits are dependent on the device, bit 15 udma */
                timing &= ~0x870F;
                timing |= mwdma_bits[speed];
        } else {
                /* Bit 15 is UDMA on/off, bit 12-14 are cycle time */
                speed = adev->dma_mode - XFER_UDMA_0;
                timing &= ~0xF000;
                timing |= udma_bits[speed];
        }
        pci_write_config_word(pdev, drive_pci, timing);
}

/**
 *      sis_100_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device to program
 *
 *      Set UDMA/MWDMA mode for device, in host controller PCI config space.
 *      Handles UDMA66 and early UDMA100 devices.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_100_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int speed = adev->dma_mode - XFER_MW_DMA_0;
        int drive_pci = sis_old_port_base(adev);
        u8 timing;

        static const u8 udma_bits[]  = { 0x8B, 0x87, 0x85, 0x83, 0x82, 0x81};

        pci_read_config_byte(pdev, drive_pci + 1, &timing);

        if (adev->dma_mode < XFER_UDMA_0) {
                /* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
        } else {
                /* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
                speed = adev->dma_mode - XFER_UDMA_0;
                timing &= ~0x8F;
                timing |= udma_bits[speed];
        }
        pci_write_config_byte(pdev, drive_pci + 1, timing);
}

/**
 *      sis_133_early_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device to program
 *
 *      Set UDMA/MWDMA mode for device, in host controller PCI config space.
 *      Handles early SiS 961 bridges.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_133_early_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int speed = adev->dma_mode - XFER_MW_DMA_0;
        int drive_pci = sis_old_port_base(adev);
        u8 timing;
        /* Low 4 bits are timing */
        static const u8 udma_bits[]  = { 0x8F, 0x8A, 0x87, 0x85, 0x83, 0x82, 0x81};

        pci_read_config_byte(pdev, drive_pci + 1, &timing);

        if (adev->dma_mode < XFER_UDMA_0) {
                /* NOT SUPPORTED YET: NEED DATA SHEET. DITTO IN OLD DRIVER */
        } else {
                /* Bit 7 is UDMA on/off, bit 0-3 are cycle time */
                speed = adev->dma_mode - XFER_UDMA_0;
                timing &= ~0x8F;
                timing |= udma_bits[speed];
        }
        pci_write_config_byte(pdev, drive_pci + 1, timing);
}

/**
 *      sis_133_set_dmamode - Initialize host controller PATA DMA timings
 *      @ap: Port whose timings we are configuring
 *      @adev: Device to program
 *
 *      Set UDMA/MWDMA mode for device, in host controller PCI config space.
 *
 *      LOCKING:
 *      None (inherited from caller).
 */

static void sis_133_set_dmamode (struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int port;
        u32 t1;

        port = sis_port_base(adev);
        pci_read_config_dword(pdev, port, &t1);

        if (adev->dma_mode < XFER_UDMA_0) {
                /* Recovery << 24 | Act << 16 | Ini << 12, like PIO modes */
                static const u32 timing_u100[] = { 0x19154000, 0x06072000, 0x04062000 };
                static const u32 timing_u133[] = { 0x221C6000, 0x0C0A3000, 0x05093000 };
                int speed = adev->dma_mode - XFER_MW_DMA_0;

                t1 &= 0xC0C00FFF;
                /* disable UDMA */
                t1 &= ~0x00000004;
                if (t1 & 0x08)
                        t1 |= timing_u133[speed];
                else
                        t1 |= timing_u100[speed];
        } else {
                /* bits 4- cycle time 8 - cvs time */
                static const u32 timing_u100[] = { 0x6B0, 0x470, 0x350, 0x140, 0x120, 0x110, 0x000 };
                static const u32 timing_u133[] = { 0x9F0, 0x6A0, 0x470, 0x250, 0x230, 0x220, 0x210 };
                int speed = adev->dma_mode - XFER_UDMA_0;

                t1 &= ~0x00000FF0;
                /* enable UDMA */
                t1 |= 0x00000004;
                if (t1 & 0x08)
                        t1 |= timing_u133[speed];
                else
                        t1 |= timing_u100[speed];
        }
        pci_write_config_dword(pdev, port, t1);
}

/**
 *      sis_133_mode_filter - mode selection filter
 *      @adev: ATA device
 *
 *      Block UDMA6 on devices that do not support it.
 */

static unsigned long sis_133_mode_filter(struct ata_device *adev, unsigned long mask)
{
        struct ata_port *ap = adev->link->ap;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int port = sis_port_base(adev);
        u32 t1;

        pci_read_config_dword(pdev, port, &t1);
        /* if ATA133 is disabled, mask it out */
        if (!(t1 & 0x08))
                mask &= ~(0xC0 << ATA_SHIFT_UDMA);
        return mask;
}

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

static struct ata_port_operations sis_133_for_sata_ops = {
        .inherits               = &ata_bmdma_port_ops,
        .set_piomode            = sis_133_set_piomode,
        .set_dmamode            = sis_133_set_dmamode,
        .cable_detect           = sis_133_cable_detect,
};

static struct ata_port_operations sis_base_ops = {
        .inherits               = &ata_bmdma_port_ops,
        .prereset               = sis_pre_reset,
};

static struct ata_port_operations sis_133_ops = {
        .inherits               = &sis_base_ops,
        .set_piomode            = sis_133_set_piomode,
        .set_dmamode            = sis_133_set_dmamode,
        .cable_detect           = sis_133_cable_detect,
        .mode_filter            = sis_133_mode_filter,
};

static struct ata_port_operations sis_133_early_ops = {
        .inherits               = &sis_base_ops,
        .set_piomode            = sis_100_set_piomode,
        .set_dmamode            = sis_133_early_set_dmamode,
        .cable_detect           = sis_66_cable_detect,
};

static struct ata_port_operations sis_100_ops = {
        .inherits               = &sis_base_ops,
        .set_piomode            = sis_100_set_piomode,
        .set_dmamode            = sis_100_set_dmamode,
        .cable_detect           = sis_66_cable_detect,
};

static struct ata_port_operations sis_66_ops = {
        .inherits               = &sis_base_ops,
        .set_piomode            = sis_old_set_piomode,
        .set_dmamode            = sis_66_set_dmamode,
        .cable_detect           = sis_66_cable_detect,
};

static struct ata_port_operations sis_old_ops = {
        .inherits               = &sis_base_ops,
        .set_piomode            = sis_old_set_piomode,
        .set_dmamode            = sis_old_set_dmamode,
        .cable_detect           = ata_cable_40wire,
};

static const struct ata_port_info sis_info = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        .mwdma_mask     = ATA_MWDMA2,
        /* No UDMA */
        .port_ops       = &sis_old_ops,
};
static const struct ata_port_info sis_info33 = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        .mwdma_mask     = ATA_MWDMA2,
        .udma_mask      = ATA_UDMA2,
        .port_ops       = &sis_old_ops,
};
static const struct ata_port_info sis_info66 = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        /* No MWDMA */
        .udma_mask      = ATA_UDMA4,
        .port_ops       = &sis_66_ops,
};
static const struct ata_port_info sis_info100 = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        /* No MWDMA */
        .udma_mask      = ATA_UDMA5,
        .port_ops       = &sis_100_ops,
};
static const struct ata_port_info sis_info100_early = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        /* No MWDMA */
        .udma_mask      = ATA_UDMA5,
        .port_ops       = &sis_66_ops,
};
static const struct ata_port_info sis_info133 = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        .mwdma_mask     = ATA_MWDMA2,
        .udma_mask      = ATA_UDMA6,
        .port_ops       = &sis_133_ops,
};
const struct ata_port_info sis_info133_for_sata = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        /* No MWDMA */
        .udma_mask      = ATA_UDMA6,
        .port_ops       = &sis_133_for_sata_ops,
};
static const struct ata_port_info sis_info133_early = {
        .flags          = ATA_FLAG_SLAVE_POSS,
        .pio_mask       = ATA_PIO4,
        /* No MWDMA */
        .udma_mask      = ATA_UDMA6,
        .port_ops       = &sis_133_early_ops,
};

/* Privately shared with the SiS180 SATA driver, not for use elsewhere */
EXPORT_SYMBOL_GPL(sis_info133_for_sata);

static void sis_fixup(struct pci_dev *pdev, struct sis_chipset *sis)
{
        u16 regw;
        u8 reg;

        if (sis->info == &sis_info133) {
                pci_read_config_word(pdev, 0x50, &regw);
                if (regw & 0x08)
                        pci_write_config_word(pdev, 0x50, regw & ~0x08);
                pci_read_config_word(pdev, 0x52, &regw);
                if (regw & 0x08)
                        pci_write_config_word(pdev, 0x52, regw & ~0x08);
                return;
        }

        if (sis->info == &sis_info133_early || sis->info == &sis_info100) {
                /* Fix up latency */
                pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0x80);
                /* Set compatibility bit */
                pci_read_config_byte(pdev, 0x49, &reg);
                if (!(reg & 0x01))
                        pci_write_config_byte(pdev, 0x49, reg | 0x01);
                return;
        }

        if (sis->info == &sis_info66 || sis->info == &sis_info100_early) {
                /* Fix up latency */
                pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0x80);
                /* Set compatibility bit */
                pci_read_config_byte(pdev, 0x52, &reg);
                if (!(reg & 0x04))
                        pci_write_config_byte(pdev, 0x52, reg | 0x04);
                return;
        }

        if (sis->info == &sis_info33) {
                pci_read_config_byte(pdev, PCI_CLASS_PROG, &reg);
                if (( reg & 0x0F ) != 0x00)
                        pci_write_config_byte(pdev, PCI_CLASS_PROG, reg & 0xF0);
                /* Fall through to ATA16 fixup below */
        }

        if (sis->info == &sis_info || sis->info == &sis_info33) {
                /* force per drive recovery and active timings
                   needed on ATA_33 and below chips */
                pci_read_config_byte(pdev, 0x52, &reg);
                if (!(reg & 0x08))
                        pci_write_config_byte(pdev, 0x52, reg|0x08);
                return;
        }

        BUG();
}

/**
 *      sis_init_one - Register SiS ATA PCI device with kernel services
 *      @pdev: PCI device to register
 *      @ent: Entry in sis_pci_tbl matching with @pdev
 *
 *      Called from kernel PCI layer. We probe for combined mode (sigh),
 *      and then hand over control to libata, for it to do the rest.
 *
 *      LOCKING:
 *      Inherited from PCI layer (may sleep).
 *
 *      RETURNS:
 *      Zero on success, or -ERRNO value.
 */

static int sis_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
{
        const struct ata_port_info *ppi[] = { NULL, NULL };
        struct pci_dev *host = NULL;
        struct sis_chipset *chipset = NULL;
        struct sis_chipset *sets;
        int rc;

        static struct sis_chipset sis_chipsets[] = {

                { 0x0968, &sis_info133 },
                { 0x0966, &sis_info133 },
                { 0x0965, &sis_info133 },
                { 0x0745, &sis_info100 },
                { 0x0735, &sis_info100 },
                { 0x0733, &sis_info100 },
                { 0x0635, &sis_info100 },
                { 0x0633, &sis_info100 },

                { 0x0730, &sis_info100_early }, /* 100 with ATA 66 layout */
                { 0x0550, &sis_info100_early }, /* 100 with ATA 66 layout */

                { 0x0640, &sis_info66 },
                { 0x0630, &sis_info66 },
                { 0x0620, &sis_info66 },
                { 0x0540, &sis_info66 },
                { 0x0530, &sis_info66 },

                { 0x5600, &sis_info33 },
                { 0x5598, &sis_info33 },
                { 0x5597, &sis_info33 },
                { 0x5591, &sis_info33 },
                { 0x5582, &sis_info33 },
                { 0x5581, &sis_info33 },

                { 0x5596, &sis_info },
                { 0x5571, &sis_info },
                { 0x5517, &sis_info },
                { 0x5511, &sis_info },

                {0}
        };
        static struct sis_chipset sis133_early = {
                0x0, &sis_info133_early
        };
        static struct sis_chipset sis133 = {
                0x0, &sis_info133
        };
        static struct sis_chipset sis100_early = {
                0x0, &sis_info100_early
        };
        static struct sis_chipset sis100 = {
                0x0, &sis_info100
        };

        ata_print_version_once(&pdev->dev, DRV_VERSION);

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

        /* We have to find the bridge first */
        for (sets = &sis_chipsets[0]; sets->device; sets++) {
                host = pci_get_device(PCI_VENDOR_ID_SI, sets->device, NULL);
                if (host != NULL) {
                        chipset = sets;                 /* Match found */
                        if (sets->device == 0x630) {    /* SIS630 */
                                if (host->revision >= 0x30)     /* 630 ET */
                                        chipset = &sis100_early;
                        }
                        break;
                }
        }

        /* Look for concealed bridges */
        if (chipset == NULL) {
                /* Second check */
                u32 idemisc;
                u16 trueid;

                /* Disable ID masking and register remapping then
                   see what the real ID is */

                pci_read_config_dword(pdev, 0x54, &idemisc);
                pci_write_config_dword(pdev, 0x54, idemisc & 0x7fffffff);
                pci_read_config_word(pdev, PCI_DEVICE_ID, &trueid);
                pci_write_config_dword(pdev, 0x54, idemisc);

                switch(trueid) {
                case 0x5518:    /* SIS 962/963 */
                        dev_info(&pdev->dev,
                                 "SiS 962/963 MuTIOL IDE UDMA133 controller\n");
                        chipset = &sis133;
                        if ((idemisc & 0x40000000) == 0) {
                                pci_write_config_dword(pdev, 0x54, idemisc | 0x40000000);
                                dev_info(&pdev->dev,
                                         "Switching to 5513 register mapping\n");
                        }
                        break;
                case 0x0180:    /* SIS 965/965L */
                        chipset = &sis133;
                        break;
                case 0x1180:    /* SIS 966/966L */
                        chipset = &sis133;
                        break;
                }
        }

        /* Further check */
        if (chipset == NULL) {
                struct pci_dev *lpc_bridge;
                u16 trueid;
                u8 prefctl;
                u8 idecfg;

                /* Try the second unmasking technique */
                pci_read_config_byte(pdev, 0x4a, &idecfg);
                pci_write_config_byte(pdev, 0x4a, idecfg | 0x10);
                pci_read_config_word(pdev, PCI_DEVICE_ID, &trueid);
                pci_write_config_byte(pdev, 0x4a, idecfg);

                switch(trueid) {
                case 0x5517:
                        lpc_bridge = pci_get_slot(pdev->bus, 0x10); /* Bus 0 Dev 2 Fn 0 */
                        if (lpc_bridge == NULL)
                                break;
                        pci_read_config_byte(pdev, 0x49, &prefctl);
                        pci_dev_put(lpc_bridge);

                        if (lpc_bridge->revision == 0x10 && (prefctl & 0x80)) {
                                chipset = &sis133_early;
                                break;
                        }
                        chipset = &sis100;
                        break;
                }
        }
        pci_dev_put(host);

        /* No chipset info, no support */
        if (chipset == NULL)
                return -ENODEV;

        ppi[0] = chipset->info;

        sis_fixup(pdev, chipset);

        return ata_pci_bmdma_init_one(pdev, ppi, &sis_sht, chipset, 0);
}

#ifdef CONFIG_PM_SLEEP
static int sis_reinit_one(struct pci_dev *pdev)
{
        struct ata_host *host = pci_get_drvdata(pdev);
        int rc;

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

        sis_fixup(pdev, host->private_data);

        ata_host_resume(host);
        return 0;
}
#endif

static const struct pci_device_id sis_pci_tbl[] = {
        { PCI_VDEVICE(SI, 0x5513), },   /* SiS 5513 */
        { PCI_VDEVICE(SI, 0x5518), },   /* SiS 5518 */
        { PCI_VDEVICE(SI, 0x1180), },   /* SiS 1180 */

        { }
};

static struct pci_driver sis_pci_driver = {
        .name                   = DRV_NAME,
        .id_table               = sis_pci_tbl,
        .probe                  = sis_init_one,
        .remove                 = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend                = ata_pci_device_suspend,
        .resume                 = sis_reinit_one,
#endif
};

module_pci_driver(sis_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("SCSI low-level driver for SiS ATA");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, sis_pci_tbl);
MODULE_VERSION(DRV_VERSION);