/*
 * pata_it821x.c        - IT821x PATA for new ATA layer
 *                        (C) 2005 Red Hat Inc
 *                        Alan Cox <alan@lxorguk.ukuu.org.uk>
 *                        (C) 2007 Bartlomiej Zolnierkiewicz
 *
 * based upon
 *
 * it821x.c
 *
 * linux/drivers/ide/pci/it821x.c               Version 0.09    December 2004
 *
 * Copyright (C) 2004           Red Hat
 *
 *  May be copied or modified under the terms of the GNU General Public License
 *  Based in part on the ITE vendor provided SCSI driver.
 *
 *  Documentation available from IT8212F_V04.pdf
 *      http://www.ite.com.tw/EN/products_more.aspx?CategoryID=3&ID=5,91
 *  Some other documents are NDA.
 *
 *  The ITE8212 isn't exactly a standard IDE controller. It has two
 *  modes. In pass through mode then it is an IDE controller. In its smart
 *  mode its actually quite a capable hardware raid controller disguised
 *  as an IDE controller. Smart mode only understands DMA read/write and
 *  identify, none of the fancier commands apply. The IT8211 is identical
 *  in other respects but lacks the raid mode.
 *
 *  Errata:
 *  o   Rev 0x10 also requires master/slave hold the same DMA timings and
 *      cannot do ATAPI MWDMA.
 *  o   The identify data for raid volumes lacks CHS info (technically ok)
 *      but also fails to set the LBA28 and other bits. We fix these in
 *      the IDE probe quirk code.
 *  o   If you write LBA48 sized I/O's (ie > 256 sector) in smart mode
 *      raid then the controller firmware dies
 *  o   Smart mode without RAID doesn't clear all the necessary identify
 *      bits to reduce the command set to the one used
 *
 *  This has a few impacts on the driver
 *  - In pass through mode we do all the work you would expect
 *  - In smart mode the clocking set up is done by the controller generally
 *    but we must watch the other limits and filter.
 *  - There are a few extra vendor commands that actually talk to the
 *    controller but only work PIO with no IRQ.
 *
 *  Vendor areas of the identify block in smart mode are used for the
 *  timing and policy set up. Each HDD in raid mode also has a serial
 *  block on the disk. The hardware extra commands are get/set chip status,
 *  rebuild, get rebuild status.
 *
 *  In Linux the driver supports pass through mode as if the device was
 *  just another IDE controller. If the smart mode is running then
 *  volumes are managed by the controller firmware and each IDE "disk"
 *  is a raid volume. Even more cute - the controller can do automated
 *  hotplug and rebuild.
 *
 *  The pass through controller itself is a little demented. It has a
 *  flaw that it has a single set of PIO/MWDMA timings per channel so
 *  non UDMA devices restrict each others performance. It also has a
 *  single clock source per channel so mixed UDMA100/133 performance
 *  isn't perfect and we have to pick a clock. Thankfully none of this
 *  matters in smart mode. ATAPI DMA is not currently supported.
 *
 *  It seems the smart mode is a win for RAID1/RAID10 but otherwise not.
 *
 *  TODO
 *      -       ATAPI and other speed filtering
 *      -       RAID configuration ioctls
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>


#define DRV_NAME "pata_it821x"
#define DRV_VERSION "0.4.2"

struct it821x_dev
{
        unsigned int smart:1,           /* Are we in smart raid mode */
                timing10:1;             /* Rev 0x10 */
        u8      clock_mode;             /* 0, ATA_50 or ATA_66 */
        u8      want[2][2];             /* Mode/Pri log for master slave */
        /* We need these for switching the clock when DMA goes on/off
           The high byte is the 66Mhz timing */
        u16     pio[2];                 /* Cached PIO values */
        u16     mwdma[2];               /* Cached MWDMA values */
        u16     udma[2];                /* Cached UDMA values (per drive) */
        u16     last_device;            /* Master or slave loaded ? */
};

#define ATA_66          0
#define ATA_50          1
#define ATA_ANY         2

#define UDMA_OFF        0
#define MWDMA_OFF       0

/*
 *      We allow users to force the card into non raid mode without
 *      flashing the alternative BIOS. This is also necessary right now
 *      for embedded platforms that cannot run a PC BIOS but are using this
 *      device.
 */

static int it8212_noraid;

/**
 *      it821x_program  -       program the PIO/MWDMA registers
 *      @ap: ATA port
 *      @adev: Device to program
 *      @timing: Timing value (66Mhz in top 8bits, 50 in the low 8)
 *
 *      Program the PIO/MWDMA timing for this channel according to the
 *      current clock. These share the same register so are managed by
 *      the DMA start/stop sequence as with the old driver.
 */

static void it821x_program(struct ata_port *ap, struct ata_device *adev, u16 timing)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct it821x_dev *itdev = ap->private_data;
        int channel = ap->port_no;
        u8 conf;

        /* Program PIO/MWDMA timing bits */
        if (itdev->clock_mode == ATA_66)
                conf = timing >> 8;
        else
                conf = timing & 0xFF;
        pci_write_config_byte(pdev, 0x54 + 4 * channel, conf);
}


/**
 *      it821x_program_udma     -       program the UDMA registers
 *      @ap: ATA port
 *      @adev: ATA device to update
 *      @timing: Timing bits. Top 8 are for 66Mhz bottom for 50Mhz
 *
 *      Program the UDMA timing for this drive according to the
 *      current clock. Handles the dual clocks and also knows about
 *      the errata on the 0x10 revision. The UDMA errata is partly handled
 *      here and partly in start_dma.
 */

static void it821x_program_udma(struct ata_port *ap, struct ata_device *adev, u16 timing)
{
        struct it821x_dev *itdev = ap->private_data;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        int channel = ap->port_no;
        int unit = adev->devno;
        u8 conf;

        /* Program UDMA timing bits */
        if (itdev->clock_mode == ATA_66)
                conf = timing >> 8;
        else
                conf = timing & 0xFF;
        if (itdev->timing10 == 0)
                pci_write_config_byte(pdev, 0x56 + 4 * channel + unit, conf);
        else {
                /* Early revision must be programmed for both together */
                pci_write_config_byte(pdev, 0x56 + 4 * channel, conf);
                pci_write_config_byte(pdev, 0x56 + 4 * channel + 1, conf);
        }
}

/**
 *      it821x_clock_strategy
 *      @ap: ATA interface
 *      @adev: ATA device being updated
 *
 *      Select between the 50 and 66Mhz base clocks to get the best
 *      results for this interface.
 */

static void it821x_clock_strategy(struct ata_port *ap, struct ata_device *adev)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct it821x_dev *itdev = ap->private_data;
        u8 unit = adev->devno;
        struct ata_device *pair = ata_dev_pair(adev);

        int clock, altclock;
        u8 v;
        int sel = 0;

        /* Look for the most wanted clocking */
        if (itdev->want[0][0] > itdev->want[1][0]) {
                clock = itdev->want[0][1];
                altclock = itdev->want[1][1];
        } else {
                clock = itdev->want[1][1];
                altclock = itdev->want[0][1];
        }

        /* Master doesn't care does the slave ? */
        if (clock == ATA_ANY)
                clock = altclock;

        /* Nobody cares - keep the same clock */
        if (clock == ATA_ANY)
                return;
        /* No change */
        if (clock == itdev->clock_mode)
                return;

        /* Load this into the controller */
        if (clock == ATA_66)
                itdev->clock_mode = ATA_66;
        else {
                itdev->clock_mode = ATA_50;
                sel = 1;
        }
        pci_read_config_byte(pdev, 0x50, &v);
        v &= ~(1 << (1 + ap->port_no));
        v |= sel << (1 + ap->port_no);
        pci_write_config_byte(pdev, 0x50, v);

        /*
         *      Reprogram the UDMA/PIO of the pair drive for the switch
         *      MWDMA will be dealt with by the dma switcher
         */
        if (pair && itdev->udma[1-unit] != UDMA_OFF) {
                it821x_program_udma(ap, pair, itdev->udma[1-unit]);
                it821x_program(ap, pair, itdev->pio[1-unit]);
        }
        /*
         *      Reprogram the UDMA/PIO of our drive for the switch.
         *      MWDMA will be dealt with by the dma switcher
         */
        if (itdev->udma[unit] != UDMA_OFF) {
                it821x_program_udma(ap, adev, itdev->udma[unit]);
                it821x_program(ap, adev, itdev->pio[unit]);
        }
}

/**
 *      it821x_passthru_set_piomode     -       set PIO mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Configure for PIO mode. This is complicated as the register is
 *      shared by PIO and MWDMA and for both channels.
 */

static void it821x_passthru_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
        /* Spec says 89 ref driver uses 88 */
        static const u16 pio[]  = { 0xAA88, 0xA382, 0xA181, 0x3332, 0x3121 };
        static const u8 pio_want[]    = { ATA_66, ATA_66, ATA_66, ATA_66, ATA_ANY };

        struct it821x_dev *itdev = ap->private_data;
        int unit = adev->devno;
        int mode_wanted = adev->pio_mode - XFER_PIO_0;

        /* We prefer 66Mhz clock for PIO 0-3, don't care for PIO4 */
        itdev->want[unit][1] = pio_want[mode_wanted];
        itdev->want[unit][0] = 1;       /* PIO is lowest priority */
        itdev->pio[unit] = pio[mode_wanted];
        it821x_clock_strategy(ap, adev);
        it821x_program(ap, adev, itdev->pio[unit]);
}

/**
 *      it821x_passthru_set_dmamode     -       set initial DMA mode data
 *      @ap: ATA interface
 *      @adev: ATA device
 *
 *      Set up the DMA modes. The actions taken depend heavily on the mode
 *      to use. If UDMA is used as is hopefully the usual case then the
 *      timing register is private and we need only consider the clock. If
 *      we are using MWDMA then we have to manage the setting ourself as
 *      we switch devices and mode.
 */

static void it821x_passthru_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
        static const u16 dma[]  =       { 0x8866, 0x3222, 0x3121 };
        static const u8 mwdma_want[] =  { ATA_ANY, ATA_66, ATA_ANY };
        static const u16 udma[] =       { 0x4433, 0x4231, 0x3121, 0x2121, 0x1111, 0x2211, 0x1111 };
        static const u8 udma_want[] =   { ATA_ANY, ATA_50, ATA_ANY, ATA_66, ATA_66, ATA_50, ATA_66 };

        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct it821x_dev *itdev = ap->private_data;
        int channel = ap->port_no;
        int unit = adev->devno;
        u8 conf;

        if (adev->dma_mode >= XFER_UDMA_0) {
                int mode_wanted = adev->dma_mode - XFER_UDMA_0;

                itdev->want[unit][1] = udma_want[mode_wanted];
                itdev->want[unit][0] = 3;       /* UDMA is high priority */
                itdev->mwdma[unit] = MWDMA_OFF;
                itdev->udma[unit] = udma[mode_wanted];
                if (mode_wanted >= 5)
                        itdev->udma[unit] |= 0x8080;    /* UDMA 5/6 select on */

                /* UDMA on. Again revision 0x10 must do the pair */
                pci_read_config_byte(pdev, 0x50, &conf);
                if (itdev->timing10)
                        conf &= channel ? 0x9F: 0xE7;
                else
                        conf &= ~ (1 << (3 + 2 * channel + unit));
                pci_write_config_byte(pdev, 0x50, conf);
                it821x_clock_strategy(ap, adev);
                it821x_program_udma(ap, adev, itdev->udma[unit]);
        } else {
                int mode_wanted = adev->dma_mode - XFER_MW_DMA_0;

                itdev->want[unit][1] = mwdma_want[mode_wanted];
                itdev->want[unit][0] = 2;       /* MWDMA is low priority */
                itdev->mwdma[unit] = dma[mode_wanted];
                itdev->udma[unit] = UDMA_OFF;

                /* UDMA bits off - Revision 0x10 do them in pairs */
                pci_read_config_byte(pdev, 0x50, &conf);
                if (itdev->timing10)
                        conf |= channel ? 0x60: 0x18;
                else
                        conf |= 1 << (3 + 2 * channel + unit);
                pci_write_config_byte(pdev, 0x50, conf);
                it821x_clock_strategy(ap, adev);
        }
}

/**
 *      it821x_passthru_bmdma_start     -       DMA start callback
 *      @qc: Command in progress
 *
 *      Usually drivers set the DMA timing at the point the set_dmamode call
 *      is made. IT821x however requires we load new timings on the
 *      transitions in some cases.
 */

static void it821x_passthru_bmdma_start(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ata_device *adev = qc->dev;
        struct it821x_dev *itdev = ap->private_data;
        int unit = adev->devno;

        if (itdev->mwdma[unit] != MWDMA_OFF)
                it821x_program(ap, adev, itdev->mwdma[unit]);
        else if (itdev->udma[unit] != UDMA_OFF && itdev->timing10)
                it821x_program_udma(ap, adev, itdev->udma[unit]);
        ata_bmdma_start(qc);
}

/**
 *      it821x_passthru_bmdma_stop      -       DMA stop callback
 *      @qc: ATA command
 *
 *      We loaded new timings in dma_start, as a result we need to restore
 *      the PIO timings in dma_stop so that the next command issue gets the
 *      right clock values.
 */

static void it821x_passthru_bmdma_stop(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct ata_device *adev = qc->dev;
        struct it821x_dev *itdev = ap->private_data;
        int unit = adev->devno;

        ata_bmdma_stop(qc);
        if (itdev->mwdma[unit] != MWDMA_OFF)
                it821x_program(ap, adev, itdev->pio[unit]);
}


/**
 *      it821x_passthru_dev_select      -       Select master/slave
 *      @ap: ATA port
 *      @device: Device number (not pointer)
 *
 *      Device selection hook. If necessary perform clock switching
 */

static void it821x_passthru_dev_select(struct ata_port *ap,
                                       unsigned int device)
{
        struct it821x_dev *itdev = ap->private_data;
        if (itdev && device != itdev->last_device) {
                struct ata_device *adev = &ap->link.device[device];
                it821x_program(ap, adev, itdev->pio[adev->devno]);
                itdev->last_device = device;
        }
        ata_sff_dev_select(ap, device);
}

/**
 *      it821x_smart_qc_issue           -       wrap qc issue prot
 *      @qc: command
 *
 *      Wrap the command issue sequence for the IT821x. We need to
 *      perform out own device selection timing loads before the
 *      usual happenings kick off
 */

static unsigned int it821x_smart_qc_issue(struct ata_queued_cmd *qc)
{
        switch(qc->tf.command)
        {
                /* Commands the firmware supports */
                case ATA_CMD_READ:
                case ATA_CMD_READ_EXT:
                case ATA_CMD_WRITE:
                case ATA_CMD_WRITE_EXT:
                case ATA_CMD_PIO_READ:
                case ATA_CMD_PIO_READ_EXT:
                case ATA_CMD_PIO_WRITE:
                case ATA_CMD_PIO_WRITE_EXT:
                case ATA_CMD_READ_MULTI:
                case ATA_CMD_READ_MULTI_EXT:
                case ATA_CMD_WRITE_MULTI:
                case ATA_CMD_WRITE_MULTI_EXT:
                case ATA_CMD_ID_ATA:
                case ATA_CMD_INIT_DEV_PARAMS:
                case 0xFC:      /* Internal 'report rebuild state' */
                /* Arguably should just no-op this one */
                case ATA_CMD_SET_FEATURES:
                        return ata_bmdma_qc_issue(qc);
        }
        ata_dev_dbg(qc->dev, "it821x: can't process command 0x%02X\n",
                    qc->tf.command);
        return AC_ERR_DEV;
}

/**
 *      it821x_passthru_qc_issue        -       wrap qc issue prot
 *      @qc: command
 *
 *      Wrap the command issue sequence for the IT821x. We need to
 *      perform out own device selection timing loads before the
 *      usual happenings kick off
 */

static unsigned int it821x_passthru_qc_issue(struct ata_queued_cmd *qc)
{
        it821x_passthru_dev_select(qc->ap, qc->dev->devno);
        return ata_bmdma_qc_issue(qc);
}

/**
 *      it821x_smart_set_mode   -       mode setting
 *      @link: interface to set up
 *      @unused: device that failed (error only)
 *
 *      Use a non standard set_mode function. We don't want to be tuned.
 *      The BIOS configured everything. Our job is not to fiddle. We
 *      read the dma enabled bits from the PCI configuration of the device
 *      and respect them.
 */

static int it821x_smart_set_mode(struct ata_link *link, struct ata_device **unused)
{
        struct ata_device *dev;

        ata_for_each_dev(dev, link, ENABLED) {
                /* We don't really care */
                dev->pio_mode = XFER_PIO_0;
                dev->dma_mode = XFER_MW_DMA_0;
                /* We do need the right mode information for DMA or PIO
                   and this comes from the current configuration flags */
                if (ata_id_has_dma(dev->id)) {
                        ata_dev_info(dev, "configured for DMA\n");
                        dev->xfer_mode = XFER_MW_DMA_0;
                        dev->xfer_shift = ATA_SHIFT_MWDMA;
                        dev->flags &= ~ATA_DFLAG_PIO;
                } else {
                        ata_dev_info(dev, "configured for PIO\n");
                        dev->xfer_mode = XFER_PIO_0;
                        dev->xfer_shift = ATA_SHIFT_PIO;
                        dev->flags |= ATA_DFLAG_PIO;
                }
        }
        return 0;
}

/**
 *      it821x_dev_config       -       Called each device identify
 *      @adev: Device that has just been identified
 *
 *      Perform the initial setup needed for each device that is chip
 *      special. In our case we need to lock the sector count to avoid
 *      blowing the brains out of the firmware with large LBA48 requests
 *
 */

static void it821x_dev_config(struct ata_device *adev)
{
        unsigned char model_num[ATA_ID_PROD_LEN + 1];

        ata_id_c_string(adev->id, model_num, ATA_ID_PROD, sizeof(model_num));

        if (adev->max_sectors > 255)
                adev->max_sectors = 255;

        if (strstr(model_num, "Integrated Technology Express")) {
                /* RAID mode */
                if (adev->id[129] == 1)
                        ata_dev_info(adev, "%sRAID%d volume\n",
                                     adev->id[147] ? "Bootable " : "",
                                     adev->id[129]);
                else
                        ata_dev_info(adev, "%sRAID%d volume (%dK stripe)\n",
                                     adev->id[147] ? "Bootable " : "",
                                     adev->id[129], adev->id[146]);
        }
        /* This is a controller firmware triggered funny, don't
           report the drive faulty! */
        adev->quirks &= ~ATA_QUIRK_DIAGNOSTIC;
        /* No HPA in 'smart' mode */
        adev->quirks |= ATA_QUIRK_BROKEN_HPA;
}

/**
 *      it821x_read_id  -       Hack identify data up
 *      @adev: device to read
 *      @tf: proposed taskfile
 *      @id: buffer for returned ident data
 *
 *      Query the devices on this firmware driven port and slightly
 *      mash the identify data to stop us and common tools trying to
 *      use features not firmware supported. The firmware itself does
 *      some masking (eg SMART) but not enough.
 */

static unsigned int it821x_read_id(struct ata_device *adev,
                                   struct ata_taskfile *tf, __le16 *id)
{
        unsigned int err_mask;
        unsigned char model_num[ATA_ID_PROD_LEN + 1];

        err_mask = ata_do_dev_read_id(adev, tf, id);
        if (err_mask)
                return err_mask;
        ata_id_c_string((u16 *)id, model_num, ATA_ID_PROD, sizeof(model_num));

        id[83] &= cpu_to_le16(~(1 << 12)); /* Cache flush is firmware handled */
        id[84] &= cpu_to_le16(~(1 << 6));  /* No FUA */
        id[85] &= cpu_to_le16(~(1 << 10)); /* No HPA */
        id[76] = 0;                        /* No NCQ/AN etc */

        if (strstr(model_num, "Integrated Technology Express")) {
                /* Set feature bits the firmware neglects */
                id[49] |= cpu_to_le16(0x0300);  /* LBA, DMA */
                id[83] &= cpu_to_le16(0x7FFF);
                id[83] |= cpu_to_le16(0x4400);  /* Word 83 is valid and LBA48 */
                id[86] |= cpu_to_le16(0x0400);  /* LBA48 on */
                id[ATA_ID_MAJOR_VER] |= cpu_to_le16(0x1F);
                /* Clear the serial number because it's different each boot
                   which breaks validation on resume */
                memset(&id[ATA_ID_SERNO], 0x20, ATA_ID_SERNO_LEN);
        }
        return err_mask;
}

/**
 *      it821x_check_atapi_dma  -       ATAPI DMA handler
 *      @qc: Command we are about to issue
 *
 *      Decide if this ATAPI command can be issued by DMA on this
 *      controller. Return 0 if it can be.
 */

static int it821x_check_atapi_dma(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct it821x_dev *itdev = ap->private_data;

        /* Only use dma for transfers to/from the media. */
        if (ata_qc_raw_nbytes(qc) < 2048)
                return -EOPNOTSUPP;

        /* No ATAPI DMA in smart mode */
        if (itdev->smart)
                return -EOPNOTSUPP;
        /* No ATAPI DMA on rev 10 */
        if (itdev->timing10)
                return -EOPNOTSUPP;
        /* Cool */
        return 0;
}

/**
 *      it821x_display_disk     -       display disk setup
 *      @ap: ATA port
 *      @n: Device number
 *      @buf: Buffer block from firmware
 *
 *      Produce a nice informative display of the device setup as provided
 *      by the firmware.
 */

static void it821x_display_disk(struct ata_port *ap, int n, u8 *buf)
{
        unsigned char id[41];
        int mode = 0;
        const char *mtype = "";
        char mbuf[8];
        const char *cbl = "(40 wire cable)";

        static const char *types[5] = {
                "RAID0", "RAID1", "RAID 0+1", "JBOD", "DISK"
        };

        if (buf[52] > 4)        /* No Disk */
                return;

        ata_id_c_string((u16 *)buf, id, 0, 41);

        if (buf[51]) {
                mode = ffs(buf[51]);
                mtype = "UDMA";
        } else if (buf[49]) {
                mode = ffs(buf[49]);
                mtype = "MWDMA";
        }

        if (buf[76])
                cbl = "";

        if (mode)
                snprintf(mbuf, sizeof(mbuf), "%5s%d", mtype, mode - 1);
        else
                strscpy(mbuf, "PIO");
        if (buf[52] == 4)
                ata_port_info(ap, "%d: %-6s %-8s          %s %s\n",
                                n, mbuf, types[buf[52]], id, cbl);
        else
                ata_port_info(ap, "%d: %-6s %-8s Volume: %1d %s %s\n",
                                n, mbuf, types[buf[52]], buf[53], id, cbl);
        if (buf[125] < 100)
                ata_port_info(ap, "%d: Rebuilding: %d%%\n", n, buf[125]);
}

/**
 *      it821x_firmware_command         -       issue firmware command
 *      @ap: IT821x port to interrogate
 *      @cmd: command
 *      @len: length
 *
 *      Issue firmware commands expecting data back from the controller. We
 *      use this to issue commands that do not go via the normal paths. Other
 *      commands such as 0xFC can be issued normally.
 */

static u8 *it821x_firmware_command(struct ata_port *ap, u8 cmd, int len)
{
        u8 status;
        int n = 0;
        u16 *buf = kmalloc(len, GFP_KERNEL);

        if (!buf)
                return NULL;

        /* This isn't quite a normal ATA command as we are talking to the
           firmware not the drives */
        ap->ctl |= ATA_NIEN;
        iowrite8(ap->ctl, ap->ioaddr.ctl_addr);
        ata_wait_idle(ap);
        iowrite8(ATA_DEVICE_OBS, ap->ioaddr.device_addr);
        iowrite8(cmd, ap->ioaddr.command_addr);
        udelay(1);
        /* This should be almost immediate but a little paranoia goes a long
           way. */
        while(n++ < 10) {
                status = ioread8(ap->ioaddr.status_addr);
                if (status & ATA_ERR) {
                        kfree(buf);
                        ata_port_err(ap, "%s: rejected\n", __func__);
                        return NULL;
                }
                if (status & ATA_DRQ) {
                        ioread16_rep(ap->ioaddr.data_addr, buf, len/2);
                        return (u8 *)buf;
                }
                usleep_range(500, 1000);
        }
        kfree(buf);
        ata_port_err(ap, "%s: timeout\n", __func__);
        return NULL;
}

/**
 *      it821x_probe_firmware   -       firmware reporting/setup
 *      @ap: IT821x port being probed
 *
 *      Probe the firmware of the controller by issuing firmware command
 *      0xFA and analysing the returned data.
 */

static void it821x_probe_firmware(struct ata_port *ap)
{
        u8 *buf;
        int i;

        /* This is a bit ugly as we can't just issue a task file to a device
           as this is controller magic */

        buf = it821x_firmware_command(ap, 0xFA, 512);

        if (buf != NULL) {
                ata_port_info(ap, "pata_it821x: Firmware %02X/%02X/%02X%02X\n",
                                buf[505],
                                buf[506],
                                buf[507],
                                buf[508]);
                for (i = 0; i < 4; i++)
                        it821x_display_disk(ap, i, buf + 128 * i);
                kfree(buf);
        }
}



/**
 *      it821x_port_start       -       port setup
 *      @ap: ATA port being set up
 *
 *      The it821x needs to maintain private data structures and also to
 *      use the standard PCI interface which lacks support for this
 *      functionality. We instead set up the private data on the port
 *      start hook, and tear it down on port stop
 */

static int it821x_port_start(struct ata_port *ap)
{
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
        struct it821x_dev *itdev;
        u8 conf;

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

        itdev = devm_kzalloc(&pdev->dev, sizeof(struct it821x_dev), GFP_KERNEL);
        if (itdev == NULL)
                return -ENOMEM;
        ap->private_data = itdev;

        pci_read_config_byte(pdev, 0x50, &conf);

        if (conf & 1) {
                itdev->smart = 1;
                /* Long I/O's although allowed in LBA48 space cause the
                   onboard firmware to enter the twighlight zone */
                /* No ATAPI DMA in this mode either */
                if (ap->port_no == 0)
                        it821x_probe_firmware(ap);
        }
        /* Pull the current clocks from 0x50 */
        if (conf & (1 << (1 + ap->port_no)))
                itdev->clock_mode = ATA_50;
        else
                itdev->clock_mode = ATA_66;

        itdev->want[0][1] = ATA_ANY;
        itdev->want[1][1] = ATA_ANY;
        itdev->last_device = -1;

        if (pdev->revision == 0x10) {
                itdev->timing10 = 1;
                /* Need to disable ATAPI DMA for this case */
                if (!itdev->smart)
                        dev_warn(&pdev->dev,
                                 "Revision 0x10, workarounds activated.\n");
        }

        return 0;
}

/**
 *      it821x_rdc_cable        -       Cable detect for RDC1010
 *      @ap: port we are checking
 *
 *      Return the RDC1010 cable type. Unlike the IT821x we know how to do
 *      this and can do host side cable detect
 */

static int it821x_rdc_cable(struct ata_port *ap)
{
        u16 r40;
        struct pci_dev *pdev = to_pci_dev(ap->host->dev);

        pci_read_config_word(pdev, 0x40, &r40);
        if (r40 & (1 << (2 + ap->port_no)))
                return ATA_CBL_PATA40;
        return ATA_CBL_PATA80;
}

static const struct scsi_host_template it821x_sht = {
        ATA_BMDMA_SHT(DRV_NAME),
};

static struct ata_port_operations it821x_smart_port_ops = {
        .inherits       = &ata_bmdma_port_ops,

        .check_atapi_dma= it821x_check_atapi_dma,
        .qc_issue       = it821x_smart_qc_issue,

        .cable_detect   = ata_cable_80wire,
        .set_mode       = it821x_smart_set_mode,
        .dev_config     = it821x_dev_config,
        .read_id        = it821x_read_id,

        .port_start     = it821x_port_start,
};

static struct ata_port_operations it821x_passthru_port_ops = {
        .inherits       = &ata_bmdma_port_ops,

        .check_atapi_dma= it821x_check_atapi_dma,
        .sff_dev_select = it821x_passthru_dev_select,
        .bmdma_start    = it821x_passthru_bmdma_start,
        .bmdma_stop     = it821x_passthru_bmdma_stop,
        .qc_issue       = it821x_passthru_qc_issue,

        .cable_detect   = ata_cable_unknown,
        .set_piomode    = it821x_passthru_set_piomode,
        .set_dmamode    = it821x_passthru_set_dmamode,

        .port_start     = it821x_port_start,
};

static struct ata_port_operations it821x_rdc_port_ops = {
        .inherits       = &ata_bmdma_port_ops,

        .check_atapi_dma= it821x_check_atapi_dma,
        .sff_dev_select = it821x_passthru_dev_select,
        .bmdma_start    = it821x_passthru_bmdma_start,
        .bmdma_stop     = it821x_passthru_bmdma_stop,
        .qc_issue       = it821x_passthru_qc_issue,

        .cable_detect   = it821x_rdc_cable,
        .set_piomode    = it821x_passthru_set_piomode,
        .set_dmamode    = it821x_passthru_set_dmamode,

        .port_start     = it821x_port_start,
};

static void it821x_disable_raid(struct pci_dev *pdev)
{
        /* Neither the RDC nor the IT8211 */
        if (pdev->vendor != PCI_VENDOR_ID_ITE ||
                        pdev->device != PCI_DEVICE_ID_ITE_8212)
                        return;

        /* Reset local CPU, and set BIOS not ready */
        pci_write_config_byte(pdev, 0x5E, 0x01);

        /* Set to bypass mode, and reset PCI bus */
        pci_write_config_byte(pdev, 0x50, 0x00);
        pci_write_config_word(pdev, PCI_COMMAND,
                              PCI_COMMAND_PARITY | PCI_COMMAND_IO |
                              PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER);
        pci_write_config_word(pdev, 0x40, 0xA0F3);

        pci_write_config_dword(pdev,0x4C, 0x02040204);
        pci_write_config_byte(pdev, 0x42, 0x36);
        pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 0x20);
}


static int it821x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
        u8 conf;

        static const struct ata_port_info info_smart = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA6,
                .port_ops = &it821x_smart_port_ops
        };
        static const struct ata_port_info info_passthru = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA6,
                .port_ops = &it821x_passthru_port_ops
        };
        static const struct ata_port_info info_rdc = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                .udma_mask = ATA_UDMA6,
                .port_ops = &it821x_rdc_port_ops
        };
        static const struct ata_port_info info_rdc_11 = {
                .flags = ATA_FLAG_SLAVE_POSS,
                .pio_mask = ATA_PIO4,
                .mwdma_mask = ATA_MWDMA2,
                /* No UDMA */
                .port_ops = &it821x_rdc_port_ops
        };

        const struct ata_port_info *ppi[] = { NULL, NULL };
        static const char *mode[2] = { "pass through", "smart" };
        int rc;

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

        if (pdev->vendor == PCI_VENDOR_ID_RDC) {
                /* Deal with Vortex86SX */
                if (pdev->revision == 0x11)
                        ppi[0] = &info_rdc_11;
                else
                        ppi[0] = &info_rdc;
        } else {
                /* Force the card into bypass mode if so requested */
                if (it8212_noraid) {
                        dev_info(&pdev->dev, "forcing bypass mode.\n");
                        it821x_disable_raid(pdev);
                }
                pci_read_config_byte(pdev, 0x50, &conf);
                conf &= 1;

                dev_info(&pdev->dev, "controller in %s mode.\n", mode[conf]);

                if (conf == 0)
                        ppi[0] = &info_passthru;
                else
                        ppi[0] = &info_smart;
        }
        return ata_pci_bmdma_init_one(pdev, ppi, &it821x_sht, NULL, 0);
}

#ifdef CONFIG_PM_SLEEP
static int it821x_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;
        /* Resume - turn raid back off if need be */
        if (it8212_noraid)
                it821x_disable_raid(pdev);
        ata_host_resume(host);
        return rc;
}
#endif

static const struct pci_device_id it821x[] = {
        { PCI_VDEVICE(ITE, PCI_DEVICE_ID_ITE_8211), },
        { PCI_VDEVICE(ITE, PCI_DEVICE_ID_ITE_8212), },
        { PCI_VDEVICE(RDC, PCI_DEVICE_ID_RDC_D1010), },

        { },
};

static struct pci_driver it821x_pci_driver = {
        .name           = DRV_NAME,
        .id_table       = it821x,
        .probe          = it821x_init_one,
        .remove         = ata_pci_remove_one,
#ifdef CONFIG_PM_SLEEP
        .suspend        = ata_pci_device_suspend,
        .resume         = it821x_reinit_one,
#endif
};

module_pci_driver(it821x_pci_driver);

MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for the IT8211/IT8212 IDE RAID controller");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, it821x);
MODULE_VERSION(DRV_VERSION);

module_param_named(noraid, it8212_noraid, int, S_IRUGO);
MODULE_PARM_DESC(noraid, "Force card into bypass mode");