/*
 * sata_inic162x.c - Driver for Initio 162x SATA controllers
 *
 * Copyright 2006  SUSE Linux Products GmbH
 * Copyright 2006  Tejun Heo <teheo@novell.com>
 *
 * This file is released under GPL v2.
 *
 * **** WARNING ****
 *
 * This driver never worked properly and unfortunately data corruption is
 * relatively common.  There isn't anyone working on the driver and there's
 * no support from the vendor.  Do not use this driver in any production
 * environment.
 *
 * http://thread.gmane.org/gmane.linux.debian.devel.bugs.rc/378525/focus=54491
 * https://bugzilla.kernel.org/show_bug.cgi?id=60565
 *
 * *****************
 *
 * This controller is eccentric and easily locks up if something isn't
 * right.  Documentation is available at initio's website but it only
 * documents registers (not programming model).
 *
 * This driver has interesting history.  The first version was written
 * from the documentation and a 2.4 IDE driver posted on a Taiwan
 * company, which didn't use any IDMA features and couldn't handle
 * LBA48.  The resulting driver couldn't handle LBA48 devices either
 * making it pretty useless.
 *
 * After a while, initio picked the driver up, renamed it to
 * sata_initio162x, updated it to use IDMA for ATA DMA commands and
 * posted it on their website.  It only used ATA_PROT_DMA for IDMA and
 * attaching both devices and issuing IDMA and !IDMA commands
 * simultaneously broke it due to PIRQ masking interaction but it did
 * show how to use the IDMA (ADMA + some initio specific twists)
 * engine.
 *
 * Then, I picked up their changes again and here's the usable driver
 * which uses IDMA for everything.  Everything works now including
 * LBA48, CD/DVD burning, suspend/resume and hotplug.  There are some
 * issues tho.  Result Tf is not resported properly, NCQ isn't
 * supported yet and CD/DVD writing works with DMA assisted PIO
 * protocol (which, for native SATA devices, shouldn't cause any
 * noticeable difference).
 *
 * Anyways, so, here's finally a working driver for inic162x.  Enjoy!
 *
 * initio: If you guys wanna improve the driver regarding result TF
 * access and other stuff, please feel free to contact me.  I'll be
 * happy to assist.
 */

#include <linux/gfp.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#include <linux/blkdev.h>
#include <scsi/scsi_device.h>

#define DRV_NAME        "sata_inic162x"
#define DRV_VERSION     "0.4"

enum {
        MMIO_BAR_PCI            = 5,
        MMIO_BAR_CARDBUS        = 1,

        NR_PORTS                = 2,

        IDMA_CPB_TBL_SIZE       = 4 * 32,

        INIC_DMA_BOUNDARY       = 0xffffff,

        HOST_ACTRL              = 0x08,
        HOST_CTL                = 0x7c,
        HOST_STAT               = 0x7e,
        HOST_IRQ_STAT           = 0xbc,
        HOST_IRQ_MASK           = 0xbe,

        PORT_SIZE               = 0x40,

        /* registers for ATA TF operation */
        PORT_TF_DATA            = 0x00,
        PORT_TF_FEATURE         = 0x01,
        PORT_TF_NSECT           = 0x02,
        PORT_TF_LBAL            = 0x03,
        PORT_TF_LBAM            = 0x04,
        PORT_TF_LBAH            = 0x05,
        PORT_TF_DEVICE          = 0x06,
        PORT_TF_COMMAND         = 0x07,
        PORT_TF_ALT_STAT        = 0x08,
        PORT_IRQ_STAT           = 0x09,
        PORT_IRQ_MASK           = 0x0a,
        PORT_PRD_CTL            = 0x0b,
        PORT_PRD_ADDR           = 0x0c,
        PORT_PRD_XFERLEN        = 0x10,
        PORT_CPB_CPBLAR         = 0x18,
        PORT_CPB_PTQFIFO        = 0x1c,

        /* IDMA register */
        PORT_IDMA_CTL           = 0x14,
        PORT_IDMA_STAT          = 0x16,

        PORT_RPQ_FIFO           = 0x1e,
        PORT_RPQ_CNT            = 0x1f,

        PORT_SCR                = 0x20,

        /* HOST_CTL bits */
        HCTL_LEDEN              = (1 << 3),  /* enable LED operation */
        HCTL_IRQOFF             = (1 << 8),  /* global IRQ off */
        HCTL_FTHD0              = (1 << 10), /* fifo threshold 0 */
        HCTL_FTHD1              = (1 << 11), /* fifo threshold 1*/
        HCTL_PWRDWN             = (1 << 12), /* power down PHYs */
        HCTL_SOFTRST            = (1 << 13), /* global reset (no phy reset) */
        HCTL_RPGSEL             = (1 << 15), /* register page select */

        HCTL_KNOWN_BITS         = HCTL_IRQOFF | HCTL_PWRDWN | HCTL_SOFTRST |
                                  HCTL_RPGSEL,

        /* HOST_IRQ_(STAT|MASK) bits */
        HIRQ_PORT0              = (1 << 0),
        HIRQ_PORT1              = (1 << 1),
        HIRQ_SOFT               = (1 << 14),
        HIRQ_GLOBAL             = (1 << 15), /* STAT only */

        /* PORT_IRQ_(STAT|MASK) bits */
        PIRQ_OFFLINE            = (1 << 0),  /* device unplugged */
        PIRQ_ONLINE             = (1 << 1),  /* device plugged */
        PIRQ_COMPLETE           = (1 << 2),  /* completion interrupt */
        PIRQ_FATAL              = (1 << 3),  /* fatal error */
        PIRQ_ATA                = (1 << 4),  /* ATA interrupt */
        PIRQ_REPLY              = (1 << 5),  /* reply FIFO not empty */
        PIRQ_PENDING            = (1 << 7),  /* port IRQ pending (STAT only) */

        PIRQ_ERR                = PIRQ_OFFLINE | PIRQ_ONLINE | PIRQ_FATAL,
        PIRQ_MASK_DEFAULT       = PIRQ_REPLY | PIRQ_ATA,
        PIRQ_MASK_FREEZE        = 0xff,

        /* PORT_PRD_CTL bits */
        PRD_CTL_START           = (1 << 0),
        PRD_CTL_WR              = (1 << 3),
        PRD_CTL_DMAEN           = (1 << 7),  /* DMA enable */

        /* PORT_IDMA_CTL bits */
        IDMA_CTL_RST_ATA        = (1 << 2),  /* hardreset ATA bus */
        IDMA_CTL_RST_IDMA       = (1 << 5),  /* reset IDMA machinary */
        IDMA_CTL_GO             = (1 << 7),  /* IDMA mode go */
        IDMA_CTL_ATA_NIEN       = (1 << 8),  /* ATA IRQ disable */

        /* PORT_IDMA_STAT bits */
        IDMA_STAT_PERR          = (1 << 0),  /* PCI ERROR MODE */
        IDMA_STAT_CPBERR        = (1 << 1),  /* ADMA CPB error */
        IDMA_STAT_LGCY          = (1 << 3),  /* ADMA legacy */
        IDMA_STAT_UIRQ          = (1 << 4),  /* ADMA unsolicited irq */
        IDMA_STAT_STPD          = (1 << 5),  /* ADMA stopped */
        IDMA_STAT_PSD           = (1 << 6),  /* ADMA pause */
        IDMA_STAT_DONE          = (1 << 7),  /* ADMA done */

        IDMA_STAT_ERR           = IDMA_STAT_PERR | IDMA_STAT_CPBERR,

        /* CPB Control Flags*/
        CPB_CTL_VALID           = (1 << 0),  /* CPB valid */
        CPB_CTL_QUEUED          = (1 << 1),  /* queued command */
        CPB_CTL_DATA            = (1 << 2),  /* data, rsvd in datasheet */
        CPB_CTL_IEN             = (1 << 3),  /* PCI interrupt enable */
        CPB_CTL_DEVDIR          = (1 << 4),  /* device direction control */

        /* CPB Response Flags */
        CPB_RESP_DONE           = (1 << 0),  /* ATA command complete */
        CPB_RESP_REL            = (1 << 1),  /* ATA release */
        CPB_RESP_IGNORED        = (1 << 2),  /* CPB ignored */
        CPB_RESP_ATA_ERR        = (1 << 3),  /* ATA command error */
        CPB_RESP_SPURIOUS       = (1 << 4),  /* ATA spurious interrupt error */
        CPB_RESP_UNDERFLOW      = (1 << 5),  /* APRD deficiency length error */
        CPB_RESP_OVERFLOW       = (1 << 6),  /* APRD exccess length error */
        CPB_RESP_CPB_ERR        = (1 << 7),  /* CPB error flag */

        /* PRD Control Flags */
        PRD_DRAIN               = (1 << 1),  /* ignore data excess */
        PRD_CDB                 = (1 << 2),  /* atapi packet command pointer */
        PRD_DIRECT_INTR         = (1 << 3),  /* direct interrupt */
        PRD_DMA                 = (1 << 4),  /* data transfer method */
        PRD_WRITE               = (1 << 5),  /* data dir, rsvd in datasheet */
        PRD_IOM                 = (1 << 6),  /* io/memory transfer */
        PRD_END                 = (1 << 7),  /* APRD chain end */
};

/* Comman Parameter Block */
struct inic_cpb {
        u8              resp_flags;     /* Response Flags */
        u8              error;          /* ATA Error */
        u8              status;         /* ATA Status */
        u8              ctl_flags;      /* Control Flags */
        __le32          len;            /* Total Transfer Length */
        __le32          prd;            /* First PRD pointer */
        u8              rsvd[4];
        /* 16 bytes */
        u8              feature;        /* ATA Feature */
        u8              hob_feature;    /* ATA Ex. Feature */
        u8              device;         /* ATA Device/Head */
        u8              mirctl;         /* Mirror Control */
        u8              nsect;          /* ATA Sector Count */
        u8              hob_nsect;      /* ATA Ex. Sector Count */
        u8              lbal;           /* ATA Sector Number */
        u8              hob_lbal;       /* ATA Ex. Sector Number */
        u8              lbam;           /* ATA Cylinder Low */
        u8              hob_lbam;       /* ATA Ex. Cylinder Low */
        u8              lbah;           /* ATA Cylinder High */
        u8              hob_lbah;       /* ATA Ex. Cylinder High */
        u8              command;        /* ATA Command */
        u8              ctl;            /* ATA Control */
        u8              slave_error;    /* Slave ATA Error */
        u8              slave_status;   /* Slave ATA Status */
        /* 32 bytes */
} __packed;

/* Physical Region Descriptor */
struct inic_prd {
        __le32          mad;            /* Physical Memory Address */
        __le16          len;            /* Transfer Length */
        u8              rsvd;
        u8              flags;          /* Control Flags */
} __packed;

struct inic_pkt {
        struct inic_cpb cpb;
        struct inic_prd prd[LIBATA_MAX_PRD + 1];        /* + 1 for cdb */
        u8              cdb[ATAPI_CDB_LEN];
} __packed;

struct inic_host_priv {
        void __iomem    *mmio_base;
        u16             cached_hctl;
};

struct inic_port_priv {
        struct inic_pkt *pkt;
        dma_addr_t      pkt_dma;
        u32             *cpb_tbl;
        dma_addr_t      cpb_tbl_dma;
};

static struct scsi_host_template inic_sht = {
        ATA_BASE_SHT(DRV_NAME),
        .sg_tablesize   = LIBATA_MAX_PRD,       /* maybe it can be larger? */
        .dma_boundary   = INIC_DMA_BOUNDARY,
};

static const int scr_map[] = {
        [SCR_STATUS]    = 0,
        [SCR_ERROR]     = 1,
        [SCR_CONTROL]   = 2,
};

static void __iomem *inic_port_base(struct ata_port *ap)
{
        struct inic_host_priv *hpriv = ap->host->private_data;

        return hpriv->mmio_base + ap->port_no * PORT_SIZE;
}

static void inic_reset_port(void __iomem *port_base)
{
        void __iomem *idma_ctl = port_base + PORT_IDMA_CTL;

        /* stop IDMA engine */
        readw(idma_ctl); /* flush */
        msleep(1);

        /* mask IRQ and assert reset */
        writew(IDMA_CTL_RST_IDMA, idma_ctl);
        readw(idma_ctl); /* flush */
        msleep(1);

        /* release reset */
        writew(0, idma_ctl);

        /* clear irq */
        writeb(0xff, port_base + PORT_IRQ_STAT);
}

static int inic_scr_read(struct ata_link *link, unsigned sc_reg, u32 *val)
{
        void __iomem *scr_addr = inic_port_base(link->ap) + PORT_SCR;

        if (unlikely(sc_reg >= ARRAY_SIZE(scr_map)))
                return -EINVAL;

        *val = readl(scr_addr + scr_map[sc_reg] * 4);

        /* this controller has stuck DIAG.N, ignore it */
        if (sc_reg == SCR_ERROR)
                *val &= ~SERR_PHYRDY_CHG;
        return 0;
}

static int inic_scr_write(struct ata_link *link, unsigned sc_reg, u32 val)
{
        void __iomem *scr_addr = inic_port_base(link->ap) + PORT_SCR;

        if (unlikely(sc_reg >= ARRAY_SIZE(scr_map)))
                return -EINVAL;

        writel(val, scr_addr + scr_map[sc_reg] * 4);
        return 0;
}

static void inic_stop_idma(struct ata_port *ap)
{
        void __iomem *port_base = inic_port_base(ap);

        readb(port_base + PORT_RPQ_FIFO);
        readb(port_base + PORT_RPQ_CNT);
        writew(0, port_base + PORT_IDMA_CTL);
}

static void inic_host_err_intr(struct ata_port *ap, u8 irq_stat, u16 idma_stat)
{
        struct ata_eh_info *ehi = &ap->link.eh_info;
        struct inic_port_priv *pp = ap->private_data;
        struct inic_cpb *cpb = &pp->pkt->cpb;
        bool freeze = false;

        ata_ehi_clear_desc(ehi);
        ata_ehi_push_desc(ehi, "irq_stat=0x%x idma_stat=0x%x",
                          irq_stat, idma_stat);

        inic_stop_idma(ap);

        if (irq_stat & (PIRQ_OFFLINE | PIRQ_ONLINE)) {
                ata_ehi_push_desc(ehi, "hotplug");
                ata_ehi_hotplugged(ehi);
                freeze = true;
        }

        if (idma_stat & IDMA_STAT_PERR) {
                ata_ehi_push_desc(ehi, "PCI error");
                freeze = true;
        }

        if (idma_stat & IDMA_STAT_CPBERR) {
                ata_ehi_push_desc(ehi, "CPB error");

                if (cpb->resp_flags & CPB_RESP_IGNORED) {
                        __ata_ehi_push_desc(ehi, " ignored");
                        ehi->err_mask |= AC_ERR_INVALID;
                        freeze = true;
                }

                if (cpb->resp_flags & CPB_RESP_ATA_ERR)
                        ehi->err_mask |= AC_ERR_DEV;

                if (cpb->resp_flags & CPB_RESP_SPURIOUS) {
                        __ata_ehi_push_desc(ehi, " spurious-intr");
                        ehi->err_mask |= AC_ERR_HSM;
                        freeze = true;
                }

                if (cpb->resp_flags &
                    (CPB_RESP_UNDERFLOW | CPB_RESP_OVERFLOW)) {
                        __ata_ehi_push_desc(ehi, " data-over/underflow");
                        ehi->err_mask |= AC_ERR_HSM;
                        freeze = true;
                }
        }

        if (freeze)
                ata_port_freeze(ap);
        else
                ata_port_abort(ap);
}

static void inic_host_intr(struct ata_port *ap)
{
        void __iomem *port_base = inic_port_base(ap);
        struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->link.active_tag);
        u8 irq_stat;
        u16 idma_stat;

        /* read and clear IRQ status */
        irq_stat = readb(port_base + PORT_IRQ_STAT);
        writeb(irq_stat, port_base + PORT_IRQ_STAT);
        idma_stat = readw(port_base + PORT_IDMA_STAT);

        if (unlikely((irq_stat & PIRQ_ERR) || (idma_stat & IDMA_STAT_ERR)))
                inic_host_err_intr(ap, irq_stat, idma_stat);

        if (unlikely(!qc))
                goto spurious;

        if (likely(idma_stat & IDMA_STAT_DONE)) {
                inic_stop_idma(ap);

                /* Depending on circumstances, device error
                 * isn't reported by IDMA, check it explicitly.
                 */
                if (unlikely(readb(port_base + PORT_TF_COMMAND) &
                             (ATA_DF | ATA_ERR)))
                        qc->err_mask |= AC_ERR_DEV;

                ata_qc_complete(qc);
                return;
        }

 spurious:
        ata_port_warn(ap, "unhandled interrupt: cmd=0x%x irq_stat=0x%x idma_stat=0x%x\n",
                      qc ? qc->tf.command : 0xff, irq_stat, idma_stat);
}

static irqreturn_t inic_interrupt(int irq, void *dev_instance)
{
        struct ata_host *host = dev_instance;
        struct inic_host_priv *hpriv = host->private_data;
        u16 host_irq_stat;
        int i, handled = 0;

        host_irq_stat = readw(hpriv->mmio_base + HOST_IRQ_STAT);

        if (unlikely(!(host_irq_stat & HIRQ_GLOBAL)))
                goto out;

        spin_lock(&host->lock);

        for (i = 0; i < NR_PORTS; i++)
                if (host_irq_stat & (HIRQ_PORT0 << i)) {
                        inic_host_intr(host->ports[i]);
                        handled++;
                }

        spin_unlock(&host->lock);

 out:
        return IRQ_RETVAL(handled);
}

static int inic_check_atapi_dma(struct ata_queued_cmd *qc)
{
        /* For some reason ATAPI_PROT_DMA doesn't work for some
         * commands including writes and other misc ops.  Use PIO
         * protocol instead, which BTW is driven by the DMA engine
         * anyway, so it shouldn't make much difference for native
         * SATA devices.
         */
        if (atapi_cmd_type(qc->cdb[0]) == READ)
                return 0;
        return 1;
}

static void inic_fill_sg(struct inic_prd *prd, struct ata_queued_cmd *qc)
{
        struct scatterlist *sg;
        unsigned int si;
        u8 flags = 0;

        if (qc->tf.flags & ATA_TFLAG_WRITE)
                flags |= PRD_WRITE;

        if (ata_is_dma(qc->tf.protocol))
                flags |= PRD_DMA;

        for_each_sg(qc->sg, sg, qc->n_elem, si) {
                prd->mad = cpu_to_le32(sg_dma_address(sg));
                prd->len = cpu_to_le16(sg_dma_len(sg));
                prd->flags = flags;
                prd++;
        }

        WARN_ON(!si);
        prd[-1].flags |= PRD_END;
}

static void inic_qc_prep(struct ata_queued_cmd *qc)
{
        struct inic_port_priv *pp = qc->ap->private_data;
        struct inic_pkt *pkt = pp->pkt;
        struct inic_cpb *cpb = &pkt->cpb;
        struct inic_prd *prd = pkt->prd;
        bool is_atapi = ata_is_atapi(qc->tf.protocol);
        bool is_data = ata_is_data(qc->tf.protocol);
        unsigned int cdb_len = 0;

        VPRINTK("ENTER\n");

        if (is_atapi)
                cdb_len = qc->dev->cdb_len;

        /* prepare packet, based on initio driver */
        memset(pkt, 0, sizeof(struct inic_pkt));

        cpb->ctl_flags = CPB_CTL_VALID | CPB_CTL_IEN;
        if (is_atapi || is_data)
                cpb->ctl_flags |= CPB_CTL_DATA;

        cpb->len = cpu_to_le32(qc->nbytes + cdb_len);
        cpb->prd = cpu_to_le32(pp->pkt_dma + offsetof(struct inic_pkt, prd));

        cpb->device = qc->tf.device;
        cpb->feature = qc->tf.feature;
        cpb->nsect = qc->tf.nsect;
        cpb->lbal = qc->tf.lbal;
        cpb->lbam = qc->tf.lbam;
        cpb->lbah = qc->tf.lbah;

        if (qc->tf.flags & ATA_TFLAG_LBA48) {
                cpb->hob_feature = qc->tf.hob_feature;
                cpb->hob_nsect = qc->tf.hob_nsect;
                cpb->hob_lbal = qc->tf.hob_lbal;
                cpb->hob_lbam = qc->tf.hob_lbam;
                cpb->hob_lbah = qc->tf.hob_lbah;
        }

        cpb->command = qc->tf.command;
        /* don't load ctl - dunno why.  it's like that in the initio driver */

        /* setup PRD for CDB */
        if (is_atapi) {
                memcpy(pkt->cdb, qc->cdb, ATAPI_CDB_LEN);
                prd->mad = cpu_to_le32(pp->pkt_dma +
                                       offsetof(struct inic_pkt, cdb));
                prd->len = cpu_to_le16(cdb_len);
                prd->flags = PRD_CDB | PRD_WRITE;
                if (!is_data)
                        prd->flags |= PRD_END;
                prd++;
        }

        /* setup sg table */
        if (is_data)
                inic_fill_sg(prd, qc);

        pp->cpb_tbl[0] = pp->pkt_dma;
}

static unsigned int inic_qc_issue(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        void __iomem *port_base = inic_port_base(ap);

        /* fire up the ADMA engine */
        writew(HCTL_FTHD0 | HCTL_LEDEN, port_base + HOST_CTL);
        writew(IDMA_CTL_GO, port_base + PORT_IDMA_CTL);
        writeb(0, port_base + PORT_CPB_PTQFIFO);

        return 0;
}

static void inic_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
        void __iomem *port_base = inic_port_base(ap);

        tf->feature     = readb(port_base + PORT_TF_FEATURE);
        tf->nsect       = readb(port_base + PORT_TF_NSECT);
        tf->lbal        = readb(port_base + PORT_TF_LBAL);
        tf->lbam        = readb(port_base + PORT_TF_LBAM);
        tf->lbah        = readb(port_base + PORT_TF_LBAH);
        tf->device      = readb(port_base + PORT_TF_DEVICE);
        tf->command     = readb(port_base + PORT_TF_COMMAND);
}

static bool inic_qc_fill_rtf(struct ata_queued_cmd *qc)
{
        struct ata_taskfile *rtf = &qc->result_tf;
        struct ata_taskfile tf;

        /* FIXME: Except for status and error, result TF access
         * doesn't work.  I tried reading from BAR0/2, CPB and BAR5.
         * None works regardless of which command interface is used.
         * For now return true iff status indicates device error.
         * This means that we're reporting bogus sector for RW
         * failures.  Eeekk....
         */
        inic_tf_read(qc->ap, &tf);

        if (!(tf.command & ATA_ERR))
                return false;

        rtf->command = tf.command;
        rtf->feature = tf.feature;
        return true;
}

static void inic_freeze(struct ata_port *ap)
{
        void __iomem *port_base = inic_port_base(ap);

        writeb(PIRQ_MASK_FREEZE, port_base + PORT_IRQ_MASK);
        writeb(0xff, port_base + PORT_IRQ_STAT);
}

static void inic_thaw(struct ata_port *ap)
{
        void __iomem *port_base = inic_port_base(ap);

        writeb(0xff, port_base + PORT_IRQ_STAT);
        writeb(PIRQ_MASK_DEFAULT, port_base + PORT_IRQ_MASK);
}

static int inic_check_ready(struct ata_link *link)
{
        void __iomem *port_base = inic_port_base(link->ap);

        return ata_check_ready(readb(port_base + PORT_TF_COMMAND));
}

/*
 * SRST and SControl hardreset don't give valid signature on this
 * controller.  Only controller specific hardreset mechanism works.
 */
static int inic_hardreset(struct ata_link *link, unsigned int *class,
                          unsigned long deadline)
{
        struct ata_port *ap = link->ap;
        void __iomem *port_base = inic_port_base(ap);
        void __iomem *idma_ctl = port_base + PORT_IDMA_CTL;
        const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
        int rc;

        /* hammer it into sane state */
        inic_reset_port(port_base);

        writew(IDMA_CTL_RST_ATA, idma_ctl);
        readw(idma_ctl);        /* flush */
        ata_msleep(ap, 1);
        writew(0, idma_ctl);

        rc = sata_link_resume(link, timing, deadline);
        if (rc) {
                ata_link_warn(link,
                              "failed to resume link after reset (errno=%d)\n",
                              rc);
                return rc;
        }

        *class = ATA_DEV_NONE;
        if (ata_link_online(link)) {
                struct ata_taskfile tf;

                /* wait for link to become ready */
                rc = ata_wait_after_reset(link, deadline, inic_check_ready);
                /* link occupied, -ENODEV too is an error */
                if (rc) {
                        ata_link_warn(link,
                                      "device not ready after hardreset (errno=%d)\n",
                                      rc);
                        return rc;
                }

                inic_tf_read(ap, &tf);
                *class = ata_dev_classify(&tf);
        }

        return 0;
}

static void inic_error_handler(struct ata_port *ap)
{
        void __iomem *port_base = inic_port_base(ap);

        inic_reset_port(port_base);
        ata_std_error_handler(ap);
}

static void inic_post_internal_cmd(struct ata_queued_cmd *qc)
{
        /* make DMA engine forget about the failed command */
        if (qc->flags & ATA_QCFLAG_FAILED)
                inic_reset_port(inic_port_base(qc->ap));
}

static void init_port(struct ata_port *ap)
{
        void __iomem *port_base = inic_port_base(ap);
        struct inic_port_priv *pp = ap->private_data;

        /* clear packet and CPB table */
        memset(pp->pkt, 0, sizeof(struct inic_pkt));
        memset(pp->cpb_tbl, 0, IDMA_CPB_TBL_SIZE);

        /* setup CPB lookup table addresses */
        writel(pp->cpb_tbl_dma, port_base + PORT_CPB_CPBLAR);
}

static int inic_port_resume(struct ata_port *ap)
{
        init_port(ap);
        return 0;
}

static int inic_port_start(struct ata_port *ap)
{
        struct device *dev = ap->host->dev;
        struct inic_port_priv *pp;

        /* alloc and initialize private data */
        pp = devm_kzalloc(dev, sizeof(*pp), GFP_KERNEL);
        if (!pp)
                return -ENOMEM;
        ap->private_data = pp;

        /* Alloc resources */
        pp->pkt = dmam_alloc_coherent(dev, sizeof(struct inic_pkt),
                                      &pp->pkt_dma, GFP_KERNEL);
        if (!pp->pkt)
                return -ENOMEM;

        pp->cpb_tbl = dmam_alloc_coherent(dev, IDMA_CPB_TBL_SIZE,
                                          &pp->cpb_tbl_dma, GFP_KERNEL);
        if (!pp->cpb_tbl)
                return -ENOMEM;

        init_port(ap);

        return 0;
}

static struct ata_port_operations inic_port_ops = {
        .inherits               = &sata_port_ops,

        .check_atapi_dma        = inic_check_atapi_dma,
        .qc_prep                = inic_qc_prep,
        .qc_issue               = inic_qc_issue,
        .qc_fill_rtf            = inic_qc_fill_rtf,

        .freeze                 = inic_freeze,
        .thaw                   = inic_thaw,
        .hardreset              = inic_hardreset,
        .error_handler          = inic_error_handler,
        .post_internal_cmd      = inic_post_internal_cmd,

        .scr_read               = inic_scr_read,
        .scr_write              = inic_scr_write,

        .port_resume            = inic_port_resume,
        .port_start             = inic_port_start,
};

static const struct ata_port_info inic_port_info = {
        .flags                  = ATA_FLAG_SATA | ATA_FLAG_PIO_DMA,
        .pio_mask               = ATA_PIO4,
        .mwdma_mask             = ATA_MWDMA2,
        .udma_mask              = ATA_UDMA6,
        .port_ops               = &inic_port_ops
};

static int init_controller(void __iomem *mmio_base, u16 hctl)
{
        int i;
        u16 val;

        hctl &= ~HCTL_KNOWN_BITS;

        /* Soft reset whole controller.  Spec says reset duration is 3
         * PCI clocks, be generous and give it 10ms.
         */
        writew(hctl | HCTL_SOFTRST, mmio_base + HOST_CTL);
        readw(mmio_base + HOST_CTL); /* flush */

        for (i = 0; i < 10; i++) {
                msleep(1);
                val = readw(mmio_base + HOST_CTL);
                if (!(val & HCTL_SOFTRST))
                        break;
        }

        if (val & HCTL_SOFTRST)
                return -EIO;

        /* mask all interrupts and reset ports */
        for (i = 0; i < NR_PORTS; i++) {
                void __iomem *port_base = mmio_base + i * PORT_SIZE;

                writeb(0xff, port_base + PORT_IRQ_MASK);
                inic_reset_port(port_base);
        }

        /* port IRQ is masked now, unmask global IRQ */
        writew(hctl & ~HCTL_IRQOFF, mmio_base + HOST_CTL);
        val = readw(mmio_base + HOST_IRQ_MASK);
        val &= ~(HIRQ_PORT0 | HIRQ_PORT1);
        writew(val, mmio_base + HOST_IRQ_MASK);

        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int inic_pci_device_resume(struct pci_dev *pdev)
{
        struct ata_host *host = pci_get_drvdata(pdev);
        struct inic_host_priv *hpriv = host->private_data;
        int rc;

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

        if (pdev->dev.power.power_state.event == PM_EVENT_SUSPEND) {
                rc = init_controller(hpriv->mmio_base, hpriv->cached_hctl);
                if (rc)
                        return rc;
        }

        ata_host_resume(host);

        return 0;
}
#endif

static int inic_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
{
        const struct ata_port_info *ppi[] = { &inic_port_info, NULL };
        struct ata_host *host;
        struct inic_host_priv *hpriv;
        void __iomem * const *iomap;
        int mmio_bar;
        int i, rc;

        ata_print_version_once(&pdev->dev, DRV_VERSION);

        dev_alert(&pdev->dev, "inic162x support is broken with common data corruption issues and will be disabled by default, contact linux-ide@vger.kernel.org if in production use\n");

        /* alloc host */
        host = ata_host_alloc_pinfo(&pdev->dev, ppi, NR_PORTS);
        hpriv = devm_kzalloc(&pdev->dev, sizeof(*hpriv), GFP_KERNEL);
        if (!host || !hpriv)
                return -ENOMEM;

        host->private_data = hpriv;

        /* Acquire resources and fill host.  Note that PCI and cardbus
         * use different BARs.
         */
        rc = pcim_enable_device(pdev);
        if (rc)
                return rc;

        if (pci_resource_flags(pdev, MMIO_BAR_PCI) & IORESOURCE_MEM)
                mmio_bar = MMIO_BAR_PCI;
        else
                mmio_bar = MMIO_BAR_CARDBUS;

        rc = pcim_iomap_regions(pdev, 1 << mmio_bar, DRV_NAME);
        if (rc)
                return rc;
        host->iomap = iomap = pcim_iomap_table(pdev);
        hpriv->mmio_base = iomap[mmio_bar];
        hpriv->cached_hctl = readw(hpriv->mmio_base + HOST_CTL);

        for (i = 0; i < NR_PORTS; i++) {
                struct ata_port *ap = host->ports[i];

                ata_port_pbar_desc(ap, mmio_bar, -1, "mmio");
                ata_port_pbar_desc(ap, mmio_bar, i * PORT_SIZE, "port");
        }

        /* Set dma_mask.  This devices doesn't support 64bit addressing. */
        rc = dma_set_mask(&pdev->dev, DMA_BIT_MASK(32));
        if (rc) {
                dev_err(&pdev->dev, "32-bit DMA enable failed\n");
                return rc;
        }

        rc = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
        if (rc) {
                dev_err(&pdev->dev, "32-bit consistent DMA enable failed\n");
                return rc;
        }

        /*
         * This controller is braindamaged.  dma_boundary is 0xffff
         * like others but it will lock up the whole machine HARD if
         * 65536 byte PRD entry is fed. Reduce maximum segment size.
         */
        rc = pci_set_dma_max_seg_size(pdev, 65536 - 512);
        if (rc) {
                dev_err(&pdev->dev, "failed to set the maximum segment size\n");
                return rc;
        }

        rc = init_controller(hpriv->mmio_base, hpriv->cached_hctl);
        if (rc) {
                dev_err(&pdev->dev, "failed to initialize controller\n");
                return rc;
        }

        pci_set_master(pdev);
        return ata_host_activate(host, pdev->irq, inic_interrupt, IRQF_SHARED,
                                 &inic_sht);
}

static const struct pci_device_id inic_pci_tbl[] = {
        { PCI_VDEVICE(INIT, 0x1622), },
        { },
};

static struct pci_driver inic_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = inic_pci_tbl,
#ifdef CONFIG_PM_SLEEP
        .suspend        = ata_pci_device_suspend,
        .resume         = inic_pci_device_resume,
#endif
        .probe          = inic_init_one,
        .remove         = ata_pci_remove_one,
};

module_pci_driver(inic_pci_driver);

MODULE_AUTHOR("Tejun Heo");
MODULE_DESCRIPTION("low-level driver for Initio 162x SATA");
MODULE_LICENSE("GPL v2");
MODULE_DEVICE_TABLE(pci, inic_pci_tbl);
MODULE_VERSION(DRV_VERSION);