bridge: Remove redundant npinfo NULL setting

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

/*
 * pata_via.c   - VIA PATA for new ATA layer
 *                        (C) 2005-2006 Red Hat Inc
 *
 *  Documentation
 *      Most chipset documentation available under NDA only
 *
 *  VIA version guide
 *      VIA VT82C561    -       early design, uses ata_generic currently
 *      VIA VT82C576    -       MWDMA, 33Mhz
 *      VIA VT82C586    -       MWDMA, 33Mhz
 *      VIA VT82C586a   -       Added UDMA to 33Mhz
 *      VIA VT82C586b   -       UDMA33
 *      VIA VT82C596a   -       Nonfunctional UDMA66
 *      VIA VT82C596b   -       Working UDMA66
 *      VIA VT82C686    -       Nonfunctional UDMA66
 *      VIA VT82C686a   -       Working UDMA66
 *      VIA VT82C686b   -       Updated to UDMA100
 *      VIA VT8231      -       UDMA100
 *      VIA VT8233      -       UDMA100
 *      VIA VT8233a     -       UDMA133
 *      VIA VT8233c     -       UDMA100
 *      VIA VT8235      -       UDMA133
 *      VIA VT8237      -       UDMA133
 *      VIA VT8237A     -       UDMA133
 *      VIA VT8237S     -       UDMA133
 *      VIA VT8251      -       UDMA133
 *
 *      Most registers remain compatible across chips. Others start reserved
 *      and acquire sensible semantics if set to 1 (eg cable detect). A few
 *      exceptions exist, notably around the FIFO settings.
 *
 *      One additional quirk of the VIA design is that like ALi they use few
 *      PCI IDs for a lot of chips.
 *
 *      Based heavily on:
 *
 * Version 3.38
 *
 * VIA IDE driver for Linux. Supported southbridges:
 *
 *   vt82c576, vt82c586, vt82c586a, vt82c586b, vt82c596a, vt82c596b,
 *   vt82c686, vt82c686a, vt82c686b, vt8231, vt8233, vt8233c, vt8233a,
 *   vt8235, vt8237
 *
 * Copyright (c) 2000-2002 Vojtech Pavlik
 *
 * Based on the work of:
 *      Michel Aubry
 *      Jeff Garzik
 *      Andre Hedrick

 */

#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/gfp.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <linux/dmi.h>

#define DRV_NAME "pata_via"
#define DRV_VERSION "0.3.4"

enum {
        VIA_BAD_PREQ    = 0x01, /* Crashes if PREQ# till DDACK# set */
        VIA_BAD_CLK66   = 0x02, /* 66 MHz clock doesn't work correctly */
        VIA_SET_FIFO    = 0x04, /* Needs to have FIFO split set */
        VIA_NO_UNMASK   = 0x08, /* Doesn't work with IRQ unmasking on */
        VIA_BAD_ID      = 0x10, /* Has wrong vendor ID (0x1107) */
        VIA_BAD_AST     = 0x20, /* Don't touch Address Setup Timing */
        VIA_NO_ENABLES  = 0x40, /* Has no enablebits */
        VIA_SATA_PATA   = 0x80, /* SATA/PATA combined configuration */
};

enum {
        VIA_IDFLAG_SINGLE = (1 << 0), /* single channel controller) */
};

/*
 * VIA SouthBridge chips.
 */

static const struct via_isa_bridge {
        const char *name;
        u16 id;
        u8 rev_min;
        u8 rev_max;
        u8 udma_mask;
        u8 flags;
} via_isa_bridges[] = {
        { "vx855",      PCI_DEVICE_ID_VIA_VX855,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST | VIA_SATA_PATA },
        { "vx800",      PCI_DEVICE_ID_VIA_VX800,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST | VIA_SATA_PATA },
        { "vt8261",     PCI_DEVICE_ID_VIA_8261,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { "vt8237s",    PCI_DEVICE_ID_VIA_8237S,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { "vt8251",     PCI_DEVICE_ID_VIA_8251,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { "cx700",      PCI_DEVICE_ID_VIA_CX700,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST | VIA_SATA_PATA },
        { "vt6410",     PCI_DEVICE_ID_VIA_6410,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST | VIA_NO_ENABLES },
        { "vt6415",     PCI_DEVICE_ID_VIA_6415,     0x00, 0xff, ATA_UDMA6, VIA_BAD_AST | VIA_NO_ENABLES },
        { "vt8237a",    PCI_DEVICE_ID_VIA_8237A,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { "vt8237",     PCI_DEVICE_ID_VIA_8237,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { "vt8235",     PCI_DEVICE_ID_VIA_8235,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { "vt8233a",    PCI_DEVICE_ID_VIA_8233A,    0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { "vt8233c",    PCI_DEVICE_ID_VIA_8233C_0,  0x00, 0x2f, ATA_UDMA5, },
        { "vt8233",     PCI_DEVICE_ID_VIA_8233_0,   0x00, 0x2f, ATA_UDMA5, },
        { "vt8231",     PCI_DEVICE_ID_VIA_8231,     0x00, 0x2f, ATA_UDMA5, },
        { "vt82c686b",  PCI_DEVICE_ID_VIA_82C686,   0x40, 0x4f, ATA_UDMA5, },
        { "vt82c686a",  PCI_DEVICE_ID_VIA_82C686,   0x10, 0x2f, ATA_UDMA4, },
        { "vt82c686",   PCI_DEVICE_ID_VIA_82C686,   0x00, 0x0f, ATA_UDMA2, VIA_BAD_CLK66 },
        { "vt82c596b",  PCI_DEVICE_ID_VIA_82C596,   0x10, 0x2f, ATA_UDMA4, },
        { "vt82c596a",  PCI_DEVICE_ID_VIA_82C596,   0x00, 0x0f, ATA_UDMA2, VIA_BAD_CLK66 },
        { "vt82c586b",  PCI_DEVICE_ID_VIA_82C586_0, 0x47, 0x4f, ATA_UDMA2, VIA_SET_FIFO },
        { "vt82c586b",  PCI_DEVICE_ID_VIA_82C586_0, 0x40, 0x46, ATA_UDMA2, VIA_SET_FIFO | VIA_BAD_PREQ },
        { "vt82c586b",  PCI_DEVICE_ID_VIA_82C586_0, 0x30, 0x3f, ATA_UDMA2, VIA_SET_FIFO },
        { "vt82c586a",  PCI_DEVICE_ID_VIA_82C586_0, 0x20, 0x2f, ATA_UDMA2, VIA_SET_FIFO },
        { "vt82c586",   PCI_DEVICE_ID_VIA_82C586_0, 0x00, 0x0f,      0x00, VIA_SET_FIFO },
        { "vt82c576",   PCI_DEVICE_ID_VIA_82C576,   0x00, 0x2f,      0x00, VIA_SET_FIFO | VIA_NO_UNMASK },
        { "vt82c576",   PCI_DEVICE_ID_VIA_82C576,   0x00, 0x2f,      0x00, VIA_SET_FIFO | VIA_NO_UNMASK | VIA_BAD_ID },
        { "vtxxxx",     PCI_DEVICE_ID_VIA_ANON,     0x00, 0x2f, ATA_UDMA6, VIA_BAD_AST },
        { NULL }
};

struct via_port {
        u8 cached_device;
};

/*
 *      Cable special cases
 */

static const struct dmi_system_id cable_dmi_table[] = {
        {
                .ident = "Acer Ferrari 3400",
                .matches = {
                        DMI_MATCH(DMI_BOARD_VENDOR, "Acer,Inc."),
                        DMI_MATCH(DMI_BOARD_NAME, "Ferrari 3400"),
                },
        },
        { }
};

static int via_cable_override(struct pci_dev *pdev)
{
        /* Systems by DMI */
        if (dmi_check_system(cable_dmi_table))
                return 1;
        /* Arima W730-K8/Targa Visionary 811/... */
        if (pdev->subsystem_vendor == 0x161F && pdev->subsystem_device == 0x2032)
                return 1;
        return 0;
}


/**
 *      via_cable_detect        -       cable detection
 *      @ap: ATA port
 *
 *      Perform cable detection. Actually for the VIA case the BIOS
 *      already did this for us. We read the values provided by the
 *      BIOS. If you are using an 8235 in a non-PC configuration you
 *      may need to update this code.
 *
 *      Hotplug also impacts on this.
 */

static int via_cable_detect(struct ata_port *ap) {
        const struct via_isa_bridge *config = ap->host->private_data;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        u32 ata66;

        if (via_cable_override(pdev))
                return ATA_CBL_PATA40_SHORT;

        if ((config->flags & VIA_SATA_PATA) && ap->port_no == 0)
                return ATA_CBL_SATA;

        /* Early chips are 40 wire */
        if (config->udma_mask < ATA_UDMA4)
                return ATA_CBL_PATA40;
        /* UDMA 66 chips have only drive side logic */
        else if (config->udma_mask < ATA_UDMA5)
                return ATA_CBL_PATA_UNK;
        /* UDMA 100 or later */
        pci_read_config_dword(pdev, 0x50, &ata66);
        /* Check both the drive cable reporting bits, we might not have
           two drives */
        if (ata66 & (0x10100000 >> (16 * ap->port_no)))
                return ATA_CBL_PATA80;
        /* Check with ACPI so we can spot BIOS reported SATA bridges */
        if (ata_acpi_init_gtm(ap) &&
            ata_acpi_cbl_80wire(ap, ata_acpi_init_gtm(ap)))
                return ATA_CBL_PATA80;
        return ATA_CBL_PATA40;
}

static int via_pre_reset(struct ata_link *link, unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        const struct via_isa_bridge *config = ap->host->private_data;

        if (!(config->flags & VIA_NO_ENABLES)) {
                static const struct pci_bits via_enable_bits[] = {
                        { 0x40, 1, 0x02, 0x02 },
                        { 0x40, 1, 0x01, 0x01 }
                };
                struct pci_dev *pdev = to_pci_dev(ap->host->dev);
                if (!pci_test_config_bits(pdev, &via_enable_bits[ap->port_no]))
                        return -ENOENT;
        }

        return ata_sff_prereset(link, deadline);
}


/**
 *      via_do_set_mode -       set transfer mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *      @mode: ATA mode being programmed
 *      @set_ast: Set to program address setup
 *      @udma_type: UDMA mode/format of registers
 *
 *      Program the VIA registers for DMA and PIO modes. Uses the ata timing
 *      support in order to compute modes.
 *
 *      FIXME: Hotplug will require we serialize multiple mode changes
 *      on the two channels.
 */

static void via_do_set_mode(struct ata_port *ap, struct ata_device *adev,
                            int mode, int set_ast, int udma_type)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct ata_device *peer = ata_dev_pair(adev);
        struct ata_timing t, p;
        static int via_clock = 33333;   /* Bus clock in kHZ */
        unsigned long T =  1000000000 / via_clock;
        unsigned long UT = T;
        int ut;
        int offset = 3 - (2*ap->port_no) - adev->devno;

        switch (udma_type) {
        case ATA_UDMA4:
                UT = T / 2; break;
        case ATA_UDMA5:
                UT = T / 3; break;
        case ATA_UDMA6:
                UT = T / 4; break;
        }

        /* Calculate the timing values we require */
        ata_timing_compute(adev, mode, &t, T, UT);

        /* We share 8bit timing so we must merge the constraints */
        if (peer) {
                if (peer->pio_mode) {
                        ata_timing_compute(peer, peer->pio_mode, &p, T, UT);
                        ata_timing_merge(&p, &t, &t, ATA_TIMING_8BIT);
                }
        }

        /* Address setup is programmable but breaks on UDMA133 setups */
        if (set_ast) {
                u8 setup;       /* 2 bits per drive */
                int shift = 2 * offset;

                pci_read_config_byte(pdev, 0x4C, &setup);
                setup &= ~(3 << shift);
                setup |= (clamp_val(t.setup, 1, 4) - 1) << shift;
                pci_write_config_byte(pdev, 0x4C, setup);
        }

        /* Load the PIO mode bits */
        pci_write_config_byte(pdev, 0x4F - ap->port_no,
                ((clamp_val(t.act8b, 1, 16) - 1) << 4) | (clamp_val(t.rec8b, 1, 16) - 1));
        pci_write_config_byte(pdev, 0x48 + offset,
                ((clamp_val(t.active, 1, 16) - 1) << 4) | (clamp_val(t.recover, 1, 16) - 1));

        /* Load the UDMA bits according to type */
        switch (udma_type) {
        case ATA_UDMA2:
        default:
                ut = t.udma ? (0xe0 | (clamp_val(t.udma, 2, 5) - 2)) : 0x03;
                break;
        case ATA_UDMA4:
                ut = t.udma ? (0xe8 | (clamp_val(t.udma, 2, 9) - 2)) : 0x0f;
                break;
        case ATA_UDMA5:
                ut = t.udma ? (0xe0 | (clamp_val(t.udma, 2, 9) - 2)) : 0x07;
                break;
        case ATA_UDMA6:
                ut = t.udma ? (0xe0 | (clamp_val(t.udma, 2, 9) - 2)) : 0x07;
                break;
        }

        /* Set UDMA unless device is not UDMA capable */
        if (udma_type) {
                u8 udma_etc;

                pci_read_config_byte(pdev, 0x50 + offset, &udma_etc);

                /* clear transfer mode bit */
                udma_etc &= ~0x20;

                if (t.udma) {
                        /* preserve 80-wire cable detection bit */
                        udma_etc &= 0x10;
                        udma_etc |= ut;
                }

                pci_write_config_byte(pdev, 0x50 + offset, udma_etc);
        }
}

static void via_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        const struct via_isa_bridge *config = ap->host->private_data;
        int set_ast = (config->flags & VIA_BAD_AST) ? 0 : 1;

        via_do_set_mode(ap, adev, adev->pio_mode, set_ast, config->udma_mask);
}

static void via_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        const struct via_isa_bridge *config = ap->host->private_data;
        int set_ast = (config->flags & VIA_BAD_AST) ? 0 : 1;

        via_do_set_mode(ap, adev, adev->dma_mode, set_ast, config->udma_mask);
}

/**
 *      via_mode_filter         -       filter buggy device/mode pairs
 *      @dev: ATA device
 *      @mask: Mode bitmask
 *
 *      We need to apply some minimal filtering for old controllers and at least
 *      one breed of Transcend SSD. Return the updated mask.
 */

static unsigned long via_mode_filter(struct ata_device *dev, unsigned long mask)
{
        struct ata_host *host = dev->link->ap->host;
        const struct via_isa_bridge *config = host->private_data;
        unsigned char model_num[ATA_ID_PROD_LEN + 1];

        if (config->id == PCI_DEVICE_ID_VIA_82C586_0) {
                ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
                if (strcmp(model_num, "TS64GSSD25-M") == 0) {
                        ata_dev_printk(dev, KERN_WARNING,
        "disabling UDMA mode due to reported lockups with this device.\n");
                        mask &= ~ ATA_MASK_UDMA;
                }
        }
        return mask;
}

/**
 *      via_tf_load - send taskfile registers to host controller
 *      @ap: Port to which output is sent
 *      @tf: ATA taskfile register set
 *
 *      Outputs ATA taskfile to standard ATA host controller.
 *
 *      Note: This is to fix the internal bug of via chipsets, which
 *      will reset the device register after changing the IEN bit on
 *      ctl register
 */
static void via_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
{
        struct ata_ioports *ioaddr = &ap->ioaddr;
        struct via_port *vp = ap->private_data;
        unsigned int is_addr = tf->flags & ATA_TFLAG_ISADDR;
        int newctl = 0;

        if (tf->ctl != ap->last_ctl) {
                iowrite8(tf->ctl, ioaddr->ctl_addr);
                ap->last_ctl = tf->ctl;
                ata_wait_idle(ap);
                newctl = 1;
        }

        if (tf->flags & ATA_TFLAG_DEVICE) {
                iowrite8(tf->device, ioaddr->device_addr);
                vp->cached_device = tf->device;
        } else if (newctl)
                iowrite8(vp->cached_device, ioaddr->device_addr);

        if (is_addr && (tf->flags & ATA_TFLAG_LBA48)) {
                WARN_ON_ONCE(!ioaddr->ctl_addr);
                iowrite8(tf->hob_feature, ioaddr->feature_addr);
                iowrite8(tf->hob_nsect, ioaddr->nsect_addr);
                iowrite8(tf->hob_lbal, ioaddr->lbal_addr);
                iowrite8(tf->hob_lbam, ioaddr->lbam_addr);
                iowrite8(tf->hob_lbah, ioaddr->lbah_addr);
                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) {
                iowrite8(tf->feature, ioaddr->feature_addr);
                iowrite8(tf->nsect, ioaddr->nsect_addr);
                iowrite8(tf->lbal, ioaddr->lbal_addr);
                iowrite8(tf->lbam, ioaddr->lbam_addr);
                iowrite8(tf->lbah, ioaddr->lbah_addr);
                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);
        }
}

static int via_port_start(struct ata_port *ap)
{
        struct via_port *vp;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        int ret = ata_bmdma_port_start(ap);
        if (ret < 0)
                return ret;

        vp = devm_kzalloc(&pdev->dev, sizeof(struct via_port), GFP_KERNEL);
        if (vp == NULL)
                return -ENOMEM;
        ap->private_data = vp;
        return 0;
}

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

static struct ata_port_operations via_port_ops = {
        .inherits       = &ata_bmdma_port_ops,
        .cable_detect   = via_cable_detect,
        .set_piomode    = via_set_piomode,
        .set_dmamode    = via_set_dmamode,
        .prereset       = via_pre_reset,
        .sff_tf_load    = via_tf_load,
        .port_start     = via_port_start,
        .mode_filter    = via_mode_filter,
};

static struct ata_port_operations via_port_ops_noirq = {
        .inherits       = &via_port_ops,
        .sff_data_xfer  = ata_sff_data_xfer_noirq,
};

/**
 *      via_config_fifo         -       set up the FIFO
 *      @pdev: PCI device
 *      @flags: configuration flags
 *
 *      Set the FIFO properties for this device if necessary. Used both on
 *      set up and on and the resume path
 */

static void via_config_fifo(struct pci_dev *pdev, unsigned int flags)
{
        u8 enable;

        /* 0x40 low bits indicate enabled channels */
        pci_read_config_byte(pdev, 0x40 , &enable);
        enable &= 3;

        if (flags & VIA_SET_FIFO) {
                static const u8 fifo_setting[4] = {0x00, 0x60, 0x00, 0x20};
                u8 fifo;

                pci_read_config_byte(pdev, 0x43, &fifo);

                /* Clear PREQ# until DDACK# for errata */
                if (flags & VIA_BAD_PREQ)
                        fifo &= 0x7F;
                else
                        fifo &= 0x9f;
                /* Turn on FIFO for enabled channels */
                fifo |= fifo_setting[enable];
                pci_write_config_byte(pdev, 0x43, fifo);
        }
}

/**
 *      via_init_one            -       discovery callback
 *      @pdev: PCI device
 *      @id: PCI table info
 *
 *      A VIA IDE interface has been discovered. Figure out what revision
 *      and perform configuration work before handing it to the ATA layer
 */

static int via_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        /* Early VIA without UDMA support */
        static const struct ata_port_info via_mwdma_info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .port_ops = &via_port_ops
        };
        /* Ditto with IRQ masking required */
        static const struct ata_port_info via_mwdma_info_borked = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .port_ops = &via_port_ops_noirq,
        };
        /* VIA UDMA 33 devices (and borked 66) */
        static const struct ata_port_info via_udma33_info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA2,
                .port_ops = &via_port_ops
        };
        /* VIA UDMA 66 devices */
        static const struct ata_port_info via_udma66_info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA4,
                .port_ops = &via_port_ops
        };
        /* VIA UDMA 100 devices */
        static const struct ata_port_info via_udma100_info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA5,
                .port_ops = &via_port_ops
        };
        /* UDMA133 with bad AST (All current 133) */
        static const struct ata_port_info via_udma133_info = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA6, /* FIXME: should check north bridge */
                .port_ops = &via_port_ops
        };
        const struct ata_port_info *ppi[] = { NULL, NULL };
        struct pci_dev *isa;
        const struct via_isa_bridge *config;
        static int printed_version;
        u8 enable;
        u32 timing;
        unsigned long flags = id->driver_data;
        int rc;

        if (!printed_version++)
                dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");

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

        if (flags & VIA_IDFLAG_SINGLE)
                ppi[1] = &ata_dummy_port_info;

        /* To find out how the IDE will behave and what features we
           actually have to look at the bridge not the IDE controller */
        for (config = via_isa_bridges; config->id != PCI_DEVICE_ID_VIA_ANON;
             config++)
                if ((isa = pci_get_device(PCI_VENDOR_ID_VIA +
                        !!(config->flags & VIA_BAD_ID),
                        config->id, NULL))) {
                        u8 rev = isa->revision;
                        pci_dev_put(isa);

                        if ((id->device == 0x0415 || id->device == 0x3164) &&
                            (config->id != id->device))
                                continue;

                        if (rev >= config->rev_min && rev <= config->rev_max)
                                break;
                }

        if (!(config->flags & VIA_NO_ENABLES)) {
                /* 0x40 low bits indicate enabled channels */
                pci_read_config_byte(pdev, 0x40 , &enable);
                enable &= 3;
                if (enable == 0)
                        return -ENODEV;
        }

        /* Initialise the FIFO for the enabled channels. */
        via_config_fifo(pdev, config->flags);

        /* Clock set up */
        switch (config->udma_mask) {
        case 0x00:
                if (config->flags & VIA_NO_UNMASK)
                        ppi[0] = &via_mwdma_info_borked;
                else
                        ppi[0] = &via_mwdma_info;
                break;
        case ATA_UDMA2:
                ppi[0] = &via_udma33_info;
                break;
        case ATA_UDMA4:
                ppi[0] = &via_udma66_info;
                break;
        case ATA_UDMA5:
                ppi[0] = &via_udma100_info;
                break;
        case ATA_UDMA6:
                ppi[0] = &via_udma133_info;
                break;
        default:
                WARN_ON(1);
                return -ENODEV;
        }

        if (config->flags & VIA_BAD_CLK66) {
                /* Disable the 66MHz clock on problem devices */
                pci_read_config_dword(pdev, 0x50, &timing);
                timing &= ~0x80008;
                pci_write_config_dword(pdev, 0x50, timing);
        }

        /* We have established the device type, now fire it up */
        return ata_pci_bmdma_init_one(pdev, ppi, &via_sht, (void *)config, 0);
}

#ifdef CONFIG_PM
/**
 *      via_reinit_one          -       reinit after resume
 *      @pdev; PCI device
 *
 *      Called when the VIA PATA device is resumed. We must then
 *      reconfigure the fifo and other setup we may have altered. In
 *      addition the kernel needs to have the resume methods on PCI
 *      quirk supported.
 */

static int via_reinit_one(struct pci_dev *pdev)
{
        u32 timing;
        struct ata_host *host = dev_get_drvdata(&pdev->dev);
        const struct via_isa_bridge *config = host->private_data;
        int rc;

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

        via_config_fifo(pdev, config->flags);

        if (config->udma_mask == ATA_UDMA4) {
                /* The 66 MHz devices require we enable the clock */
                pci_read_config_dword(pdev, 0x50, &timing);
                timing |= 0x80008;
                pci_write_config_dword(pdev, 0x50, timing);
        }
        if (config->flags & VIA_BAD_CLK66) {
                /* Disable the 66MHz clock on problem devices */
                pci_read_config_dword(pdev, 0x50, &timing);
                timing &= ~0x80008;
                pci_write_config_dword(pdev, 0x50, timing);
        }

        ata_host_resume(host);
        return 0;
}
#endif

static const struct pci_device_id via[] = {
        { PCI_VDEVICE(VIA, 0x0415), },
        { PCI_VDEVICE(VIA, 0x0571), },
        { PCI_VDEVICE(VIA, 0x0581), },
        { PCI_VDEVICE(VIA, 0x1571), },
        { PCI_VDEVICE(VIA, 0x3164), },
        { PCI_VDEVICE(VIA, 0x5324), },
        { PCI_VDEVICE(VIA, 0xC409), VIA_IDFLAG_SINGLE },
        { PCI_VDEVICE(VIA, 0x9001), VIA_IDFLAG_SINGLE },

        { },
};

static struct pci_driver via_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = via,
        .probe          = via_init_one,
        .remove         = ata_pci_remove_one,
#ifdef CONFIG_PM
        .suspend        = ata_pci_device_suspend,
        .resume         = via_reinit_one,
#endif
};

static int __init via_init(void)
{
        return pci_register_driver(&via_pci_driver);
}

static void __exit via_exit(void)
{
        pci_unregister_driver(&via_pci_driver);
}

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for VIA PATA");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, via);
MODULE_VERSION(DRV_VERSION);

module_init(via_init);
module_exit(via_exit);