shuttle_usbat.c

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/* Driver for SCM Microsystems (a.k.a. Shuttle) USB-ATAPI cable
 *
 * Current development and maintenance by:
 *   (c) 2000, 2001 Robert Baruch ([email protected])
 *   (c) 2004, 2005 Daniel Drake <[email protected]>
 *
 * Developed with the assistance of:
 *   (c) 2002 Alan Stern <[email protected]>
 *
 * Flash support based on earlier work by:
 *   (c) 2002 Thomas Kreiling <[email protected]>
 *
 * Many originally ATAPI devices were slightly modified to meet the USB
 * market by using some kind of translation from ATAPI to USB on the host,
 * and the peripheral would translate from USB back to ATAPI.
 *
 * SCM Microsystems (www.scmmicro.com) makes a device, sold to OEM's only, 
 * which does the USB-to-ATAPI conversion.  By obtaining the data sheet on
 * their device under nondisclosure agreement, I have been able to write
 * this driver for Linux.
 *
 * The chip used in the device can also be used for EPP and ISA translation
 * as well. This driver is only guaranteed to work with the ATAPI
 * translation.
 *
 * See the Kconfig help text for a list of devices known to be supported by
 * this driver.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2, or (at your option) any
 * later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/cdrom.h>

#include <scsi/scsi.h>
#include <scsi/scsi_cmnd.h>

#include "usb.h"
#include "transport.h"
#include "protocol.h"
#include "debug.h"

MODULE_DESCRIPTION("Driver for SCM Microsystems (a.k.a. Shuttle) USB-ATAPI cable");
MODULE_AUTHOR("Daniel Drake <[email protected]>, Robert Baruch <[email protected]>");
MODULE_LICENSE("GPL");

/* Supported device types */
#define USBAT_DEV_HP8200    0x01
#define USBAT_DEV_FLASH     0x02

#define USBAT_EPP_PORT      0x10
#define USBAT_EPP_REGISTER  0x30
#define USBAT_ATA       0x40
#define USBAT_ISA       0x50

/* Commands (need to be logically OR'd with an access type */
#define USBAT_CMD_READ_REG      0x00
#define USBAT_CMD_WRITE_REG     0x01
#define USBAT_CMD_READ_BLOCK    0x02
#define USBAT_CMD_WRITE_BLOCK   0x03
#define USBAT_CMD_COND_READ_BLOCK   0x04
#define USBAT_CMD_COND_WRITE_BLOCK  0x05
#define USBAT_CMD_WRITE_REGS    0x07

/* Commands (these don't need an access type) */
#define USBAT_CMD_EXEC_CMD  0x80
#define USBAT_CMD_SET_FEAT  0x81
#define USBAT_CMD_UIO       0x82

/* Methods of accessing UIO register */
#define USBAT_UIO_READ  1
#define USBAT_UIO_WRITE 0

/* Qualifier bits */
#define USBAT_QUAL_FCQ  0x20    /* full compare */
#define USBAT_QUAL_ALQ  0x10    /* auto load subcount */

/* USBAT Flash Media status types */
#define USBAT_FLASH_MEDIA_NONE  0
#define USBAT_FLASH_MEDIA_CF    1

/* USBAT Flash Media change types */
#define USBAT_FLASH_MEDIA_SAME  0
#define USBAT_FLASH_MEDIA_CHANGED   1

/* USBAT ATA registers */
#define USBAT_ATA_DATA      0x10  /* read/write data (R/W) */
#define USBAT_ATA_FEATURES  0x11  /* set features (W) */
#define USBAT_ATA_ERROR     0x11  /* error (R) */
#define USBAT_ATA_SECCNT    0x12  /* sector count (R/W) */
#define USBAT_ATA_SECNUM    0x13  /* sector number (R/W) */
#define USBAT_ATA_LBA_ME    0x14  /* cylinder low (R/W) */
#define USBAT_ATA_LBA_HI    0x15  /* cylinder high (R/W) */
#define USBAT_ATA_DEVICE    0x16  /* head/device selection (R/W) */
#define USBAT_ATA_STATUS    0x17  /* device status (R) */
#define USBAT_ATA_CMD       0x17  /* device command (W) */
#define USBAT_ATA_ALTSTATUS 0x0E  /* status (no clear IRQ) (R) */

/* USBAT User I/O Data registers */
#define USBAT_UIO_EPAD      0x80 /* Enable Peripheral Control Signals */
#define USBAT_UIO_CDT       0x40 /* Card Detect (Read Only) */
                     /* CDT = ACKD & !UI1 & !UI0 */
#define USBAT_UIO_1     0x20 /* I/O 1 */
#define USBAT_UIO_0     0x10 /* I/O 0 */
#define USBAT_UIO_EPP_ATA   0x08 /* 1=EPP mode, 0=ATA mode */
#define USBAT_UIO_UI1       0x04 /* Input 1 */
#define USBAT_UIO_UI0       0x02 /* Input 0 */
#define USBAT_UIO_INTR_ACK  0x01 /* Interrupt (ATA/ISA)/Acknowledge (EPP) */

/* USBAT User I/O Enable registers */
#define USBAT_UIO_DRVRST    0x80 /* Reset Peripheral */
#define USBAT_UIO_ACKD      0x40 /* Enable Card Detect */
#define USBAT_UIO_OE1       0x20 /* I/O 1 set=output/clr=input */
                     /* If ACKD=1, set OE1 to 1 also. */
#define USBAT_UIO_OE0       0x10 /* I/O 0 set=output/clr=input */
#define USBAT_UIO_ADPRST    0x01 /* Reset SCM chip */

/* USBAT Features */
#define USBAT_FEAT_ETEN 0x80    /* External trigger enable */
#define USBAT_FEAT_U1   0x08
#define USBAT_FEAT_U0   0x04
#define USBAT_FEAT_ET1  0x02
#define USBAT_FEAT_ET2  0x01

struct usbat_info {
    int devicetype;

    /* Used for Flash readers only */
    unsigned long sectors;     /* total sector count */
    unsigned long ssize;       /* sector size in bytes */

    unsigned char sense_key;
    unsigned long sense_asc;   /* additional sense code */
    unsigned long sense_ascq;  /* additional sense code qualifier */
};

#define short_pack(LSB,MSB) ( ((u16)(LSB)) | ( ((u16)(MSB))<<8 ) )
#define LSB_of(s) ((s)&0xFF)
#define MSB_of(s) ((s)>>8)

static int transferred = 0;

static int usbat_flash_transport(struct scsi_cmnd * srb, struct us_data *us);
static int usbat_hp8200e_transport(struct scsi_cmnd *srb, struct us_data *us);

static int init_usbat_cd(struct us_data *us);
static int init_usbat_flash(struct us_data *us);


/*
 * The table of devices
 */
#define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
            vendorName, productName, useProtocol, useTransport, \
            initFunction, flags) \
{ USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
  .driver_info = (flags) }

static struct usb_device_id usbat_usb_ids[] = {
#   include "unusual_usbat.h"
    { }     /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, usbat_usb_ids);

#undef UNUSUAL_DEV

/*
 * The flags table
 */
#define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
            vendor_name, product_name, use_protocol, use_transport, \
            init_function, Flags) \
{ \
    .vendorName = vendor_name,  \
    .productName = product_name,    \
    .useProtocol = use_protocol,    \
    .useTransport = use_transport,  \
    .initFunction = init_function,  \
}

static struct us_unusual_dev usbat_unusual_dev_list[] = {
#   include "unusual_usbat.h"
    { }     /* Terminating entry */
};

#undef UNUSUAL_DEV

/*
 * Convenience function to produce an ATA read/write sectors command
 * Use cmd=0x20 for read, cmd=0x30 for write
 */
static void usbat_pack_ata_sector_cmd(unsigned char *buf,
                    unsigned char thistime,
                    u32 sector, unsigned char cmd)
{
    buf[0] = 0;
    buf[1] = thistime;
    buf[2] = sector & 0xFF;
    buf[3] = (sector >>  8) & 0xFF;
    buf[4] = (sector >> 16) & 0xFF;
    buf[5] = 0xE0 | ((sector >> 24) & 0x0F);
    buf[6] = cmd;
}

/*
 * Convenience function to get the device type (flash or hp8200)
 */
static int usbat_get_device_type(struct us_data *us)
{
    return ((struct usbat_info*)us->extra)->devicetype;
}

/*
 * Read a register from the device
 */
static int usbat_read(struct us_data *us,
              unsigned char access,
              unsigned char reg,
              unsigned char *content)
{
    return usb_stor_ctrl_transfer(us,
        us->recv_ctrl_pipe,
        access | USBAT_CMD_READ_REG,
        0xC0,
        (u16)reg,
        0,
        content,
        1);
}

/*
 * Write to a register on the device
 */
static int usbat_write(struct us_data *us,
               unsigned char access,
               unsigned char reg,
               unsigned char content)
{
    return usb_stor_ctrl_transfer(us,
        us->send_ctrl_pipe,
        access | USBAT_CMD_WRITE_REG,
        0x40,
        short_pack(reg, content),
        0,
        NULL,
        0);
}

/*
 * Convenience function to perform a bulk read
 */
static int usbat_bulk_read(struct us_data *us,
               void* buf,
               unsigned int len,
               int use_sg)
{
    if (len == 0)
        return USB_STOR_XFER_GOOD;

    US_DEBUGP("usbat_bulk_read: len = %d\n", len);
    return usb_stor_bulk_transfer_sg(us, us->recv_bulk_pipe, buf, len, use_sg, NULL);
}

/*
 * Convenience function to perform a bulk write
 */
static int usbat_bulk_write(struct us_data *us,
                void* buf,
                unsigned int len,
                int use_sg)
{
    if (len == 0)
        return USB_STOR_XFER_GOOD;

    US_DEBUGP("usbat_bulk_write:  len = %d\n", len);
    return usb_stor_bulk_transfer_sg(us, us->send_bulk_pipe, buf, len, use_sg, NULL);
}

/*
 * Some USBAT-specific commands can only be executed over a command transport
 * This transport allows one (len=8) or two (len=16) vendor-specific commands
 * to be executed.
 */
static int usbat_execute_command(struct us_data *us,
                                 unsigned char *commands,
                                 unsigned int len)
{
    return usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
                                  USBAT_CMD_EXEC_CMD, 0x40, 0, 0,
                                  commands, len);
}

/*
 * Read the status register
 */
static int usbat_get_status(struct us_data *us, unsigned char *status)
{
    int rc;
    rc = usbat_read(us, USBAT_ATA, USBAT_ATA_STATUS, status);

    US_DEBUGP("usbat_get_status: 0x%02X\n", (unsigned short) (*status));
    return rc;
}

/*
 * Check the device status
 */
static int usbat_check_status(struct us_data *us)
{
    unsigned char *reply = us->iobuf;
    int rc;

    rc = usbat_get_status(us, reply);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_FAILED;

    /* error/check condition (0x51 is ok) */
    if (*reply & 0x01 && *reply != 0x51)
        return USB_STOR_TRANSPORT_FAILED;

    /* device fault */
    if (*reply & 0x20)
        return USB_STOR_TRANSPORT_FAILED;

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Stores critical information in internal registers in preparation for the execution
 * of a conditional usbat_read_blocks or usbat_write_blocks call.
 */
static int usbat_set_shuttle_features(struct us_data *us,
                      unsigned char external_trigger,
                      unsigned char epp_control,
                      unsigned char mask_byte,
                      unsigned char test_pattern,
                      unsigned char subcountH,
                      unsigned char subcountL)
{
    unsigned char *command = us->iobuf;

    command[0] = 0x40;
    command[1] = USBAT_CMD_SET_FEAT;

    /*
     * The only bit relevant to ATA access is bit 6
     * which defines 8 bit data access (set) or 16 bit (unset)
     */
    command[2] = epp_control;

    /*
     * If FCQ is set in the qualifier (defined in R/W cmd), then bits U0, U1,
     * ET1 and ET2 define an external event to be checked for on event of a
     * _read_blocks or _write_blocks operation. The read/write will not take
     * place unless the defined trigger signal is active.
     */
    command[3] = external_trigger;

    /*
     * The resultant byte of the mask operation (see mask_byte) is compared for
     * equivalence with this test pattern. If equal, the read/write will take
     * place.
     */
    command[4] = test_pattern;

    /*
     * This value is logically ANDed with the status register field specified
     * in the read/write command.
     */
    command[5] = mask_byte;

    /*
     * If ALQ is set in the qualifier, this field contains the address of the
     * registers where the byte count should be read for transferring the data.
     * If ALQ is not set, then this field contains the number of bytes to be
     * transferred.
     */
    command[6] = subcountL;
    command[7] = subcountH;

    return usbat_execute_command(us, command, 8);
}

/*
 * Block, waiting for an ATA device to become not busy or to report
 * an error condition.
 */
static int usbat_wait_not_busy(struct us_data *us, int minutes)
{
    int i;
    int result;
    unsigned char *status = us->iobuf;

    /* Synchronizing cache on a CDR could take a heck of a long time,
     * but probably not more than 10 minutes or so. On the other hand,
     * doing a full blank on a CDRW at speed 1 will take about 75
     * minutes!
     */

    for (i=0; i<1200+minutes*60; i++) {

        result = usbat_get_status(us, status);

        if (result!=USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;
        if (*status & 0x01) { /* check condition */
            result = usbat_read(us, USBAT_ATA, 0x10, status);
            return USB_STOR_TRANSPORT_FAILED;
        }
        if (*status & 0x20) /* device fault */
            return USB_STOR_TRANSPORT_FAILED;

        if ((*status & 0x80)==0x00) { /* not busy */
            US_DEBUGP("Waited not busy for %d steps\n", i);
            return USB_STOR_TRANSPORT_GOOD;
        }

        if (i<500)
            msleep(10); /* 5 seconds */
        else if (i<700)
            msleep(50); /* 10 seconds */
        else if (i<1200)
            msleep(100); /* 50 seconds */
        else
            msleep(1000); /* X minutes */
    }

    US_DEBUGP("Waited not busy for %d minutes, timing out.\n",
        minutes);
    return USB_STOR_TRANSPORT_FAILED;
}

/*
 * Read block data from the data register
 */
static int usbat_read_block(struct us_data *us,
                void* buf,
                unsigned short len,
                int use_sg)
{
    int result;
    unsigned char *command = us->iobuf;

    if (!len)
        return USB_STOR_TRANSPORT_GOOD;

    command[0] = 0xC0;
    command[1] = USBAT_ATA | USBAT_CMD_READ_BLOCK;
    command[2] = USBAT_ATA_DATA;
    command[3] = 0;
    command[4] = 0;
    command[5] = 0;
    command[6] = LSB_of(len);
    command[7] = MSB_of(len);

    result = usbat_execute_command(us, command, 8);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    result = usbat_bulk_read(us, buf, len, use_sg);
    return (result == USB_STOR_XFER_GOOD ?
            USB_STOR_TRANSPORT_GOOD : USB_STOR_TRANSPORT_ERROR);
}

/*
 * Write block data via the data register
 */
static int usbat_write_block(struct us_data *us,
                 unsigned char access,
                 void* buf,
                 unsigned short len,
                 int minutes,
                 int use_sg)
{
    int result;
    unsigned char *command = us->iobuf;

    if (!len)
        return USB_STOR_TRANSPORT_GOOD;

    command[0] = 0x40;
    command[1] = access | USBAT_CMD_WRITE_BLOCK;
    command[2] = USBAT_ATA_DATA;
    command[3] = 0;
    command[4] = 0;
    command[5] = 0;
    command[6] = LSB_of(len);
    command[7] = MSB_of(len);

    result = usbat_execute_command(us, command, 8);

    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    result = usbat_bulk_write(us, buf, len, use_sg);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    return usbat_wait_not_busy(us, minutes);
}

/*
 * Process read and write requests
 */
static int usbat_hp8200e_rw_block_test(struct us_data *us,
                       unsigned char access,
                       unsigned char *registers,
                       unsigned char *data_out,
                       unsigned short num_registers,
                       unsigned char data_reg,
                       unsigned char status_reg,
                       unsigned char timeout,
                       unsigned char qualifier,
                       int direction,
                       void *buf,
                       unsigned short len,
                       int use_sg,
                       int minutes)
{
    int result;
    unsigned int pipe = (direction == DMA_FROM_DEVICE) ?
            us->recv_bulk_pipe : us->send_bulk_pipe;

    unsigned char *command = us->iobuf;
    int i, j;
    int cmdlen;
    unsigned char *data = us->iobuf;
    unsigned char *status = us->iobuf;

    BUG_ON(num_registers > US_IOBUF_SIZE/2);

    for (i=0; i<20; i++) {

        /*
         * The first time we send the full command, which consists
         * of downloading the SCSI command followed by downloading
         * the data via a write-and-test.  Any other time we only
         * send the command to download the data -- the SCSI command
         * is still 'active' in some sense in the device.
         * 
         * We're only going to try sending the data 10 times. After
         * that, we just return a failure.
         */

        if (i==0) {
            cmdlen = 16;
            /*
             * Write to multiple registers
             * Not really sure the 0x07, 0x17, 0xfc, 0xe7 is
             * necessary here, but that's what came out of the
             * trace every single time.
             */
            command[0] = 0x40;
            command[1] = access | USBAT_CMD_WRITE_REGS;
            command[2] = 0x07;
            command[3] = 0x17;
            command[4] = 0xFC;
            command[5] = 0xE7;
            command[6] = LSB_of(num_registers*2);
            command[7] = MSB_of(num_registers*2);
        } else
            cmdlen = 8;

        /* Conditionally read or write blocks */
        command[cmdlen-8] = (direction==DMA_TO_DEVICE ? 0x40 : 0xC0);
        command[cmdlen-7] = access |
                (direction==DMA_TO_DEVICE ?
                 USBAT_CMD_COND_WRITE_BLOCK : USBAT_CMD_COND_READ_BLOCK);
        command[cmdlen-6] = data_reg;
        command[cmdlen-5] = status_reg;
        command[cmdlen-4] = timeout;
        command[cmdlen-3] = qualifier;
        command[cmdlen-2] = LSB_of(len);
        command[cmdlen-1] = MSB_of(len);

        result = usbat_execute_command(us, command, cmdlen);

        if (result != USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (i==0) {

            for (j=0; j<num_registers; j++) {
                data[j<<1] = registers[j];
                data[1+(j<<1)] = data_out[j];
            }

            result = usbat_bulk_write(us, data, num_registers*2, 0);
            if (result != USB_STOR_XFER_GOOD)
                return USB_STOR_TRANSPORT_ERROR;

        }

        result = usb_stor_bulk_transfer_sg(us,
            pipe, buf, len, use_sg, NULL);

        /*
         * If we get a stall on the bulk download, we'll retry
         * the bulk download -- but not the SCSI command because
         * in some sense the SCSI command is still 'active' and
         * waiting for the data. Don't ask me why this should be;
         * I'm only following what the Windoze driver did.
         *
         * Note that a stall for the test-and-read/write command means
         * that the test failed. In this case we're testing to make
         * sure that the device is error-free
         * (i.e. bit 0 -- CHK -- of status is 0). The most likely
         * hypothesis is that the USBAT chip somehow knows what
         * the device will accept, but doesn't give the device any
         * data until all data is received. Thus, the device would
         * still be waiting for the first byte of data if a stall
         * occurs, even if the stall implies that some data was
         * transferred.
         */

        if (result == USB_STOR_XFER_SHORT ||
                result == USB_STOR_XFER_STALLED) {

            /*
             * If we're reading and we stalled, then clear
             * the bulk output pipe only the first time.
             */

            if (direction==DMA_FROM_DEVICE && i==0) {
                if (usb_stor_clear_halt(us,
                        us->send_bulk_pipe) < 0)
                    return USB_STOR_TRANSPORT_ERROR;
            }

            /*
             * Read status: is the device angry, or just busy?
             */

            result = usbat_read(us, USBAT_ATA, 
                direction==DMA_TO_DEVICE ?
                    USBAT_ATA_STATUS : USBAT_ATA_ALTSTATUS,
                status);

            if (result!=USB_STOR_XFER_GOOD)
                return USB_STOR_TRANSPORT_ERROR;
            if (*status & 0x01) /* check condition */
                return USB_STOR_TRANSPORT_FAILED;
            if (*status & 0x20) /* device fault */
                return USB_STOR_TRANSPORT_FAILED;

            US_DEBUGP("Redoing %s\n",
              direction==DMA_TO_DEVICE ? "write" : "read");

        } else if (result != USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;
        else
            return usbat_wait_not_busy(us, minutes);

    }

    US_DEBUGP("Bummer! %s bulk data 20 times failed.\n",
        direction==DMA_TO_DEVICE ? "Writing" : "Reading");

    return USB_STOR_TRANSPORT_FAILED;
}

/*
 * Write to multiple registers:
 * Allows us to write specific data to any registers. The data to be written
 * gets packed in this sequence: reg0, data0, reg1, data1, ..., regN, dataN
 * which gets sent through bulk out.
 * Not designed for large transfers of data!
 */
static int usbat_multiple_write(struct us_data *us,
                unsigned char *registers,
                unsigned char *data_out,
                unsigned short num_registers)
{
    int i, result;
    unsigned char *data = us->iobuf;
    unsigned char *command = us->iobuf;

    BUG_ON(num_registers > US_IOBUF_SIZE/2);

    /* Write to multiple registers, ATA access */
    command[0] = 0x40;
    command[1] = USBAT_ATA | USBAT_CMD_WRITE_REGS;

    /* No relevance */
    command[2] = 0;
    command[3] = 0;
    command[4] = 0;
    command[5] = 0;

    /* Number of bytes to be transferred (incl. addresses and data) */
    command[6] = LSB_of(num_registers*2);
    command[7] = MSB_of(num_registers*2);

    /* The setup command */
    result = usbat_execute_command(us, command, 8);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    /* Create the reg/data, reg/data sequence */
    for (i=0; i<num_registers; i++) {
        data[i<<1] = registers[i];
        data[1+(i<<1)] = data_out[i];
    }

    /* Send the data */
    result = usbat_bulk_write(us, data, num_registers*2, 0);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    if (usbat_get_device_type(us) == USBAT_DEV_HP8200)
        return usbat_wait_not_busy(us, 0);
    else
        return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Conditionally read blocks from device:
 * Allows us to read blocks from a specific data register, based upon the
 * condition that a status register can be successfully masked with a status
 * qualifier. If this condition is not initially met, the read will wait
 * up until a maximum amount of time has elapsed, as specified by timeout.
 * The read will start when the condition is met, otherwise the command aborts.
 *
 * The qualifier defined here is not the value that is masked, it defines
 * conditions for the write to take place. The actual masked qualifier (and
 * other related details) are defined beforehand with _set_shuttle_features().
 */
static int usbat_read_blocks(struct us_data *us,
                 void* buffer,
                 int len,
                 int use_sg)
{
    int result;
    unsigned char *command = us->iobuf;

    command[0] = 0xC0;
    command[1] = USBAT_ATA | USBAT_CMD_COND_READ_BLOCK;
    command[2] = USBAT_ATA_DATA;
    command[3] = USBAT_ATA_STATUS;
    command[4] = 0xFD; /* Timeout (ms); */
    command[5] = USBAT_QUAL_FCQ;
    command[6] = LSB_of(len);
    command[7] = MSB_of(len);

    /* Multiple block read setup command */
    result = usbat_execute_command(us, command, 8);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_FAILED;
    
    /* Read the blocks we just asked for */
    result = usbat_bulk_read(us, buffer, len, use_sg);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_FAILED;

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Conditionally write blocks to device:
 * Allows us to write blocks to a specific data register, based upon the
 * condition that a status register can be successfully masked with a status
 * qualifier. If this condition is not initially met, the write will wait
 * up until a maximum amount of time has elapsed, as specified by timeout.
 * The read will start when the condition is met, otherwise the command aborts.
 *
 * The qualifier defined here is not the value that is masked, it defines
 * conditions for the write to take place. The actual masked qualifier (and
 * other related details) are defined beforehand with _set_shuttle_features().
 */
static int usbat_write_blocks(struct us_data *us,
                  void* buffer,
                  int len,
                  int use_sg)
{
    int result;
    unsigned char *command = us->iobuf;

    command[0] = 0x40;
    command[1] = USBAT_ATA | USBAT_CMD_COND_WRITE_BLOCK;
    command[2] = USBAT_ATA_DATA;
    command[3] = USBAT_ATA_STATUS;
    command[4] = 0xFD; /* Timeout (ms) */
    command[5] = USBAT_QUAL_FCQ;
    command[6] = LSB_of(len);
    command[7] = MSB_of(len);

    /* Multiple block write setup command */
    result = usbat_execute_command(us, command, 8);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_FAILED;
    
    /* Write the data */
    result = usbat_bulk_write(us, buffer, len, use_sg);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_FAILED;

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Read the User IO register
 */
static int usbat_read_user_io(struct us_data *us, unsigned char *data_flags)
{
    int result;

    result = usb_stor_ctrl_transfer(us,
        us->recv_ctrl_pipe,
        USBAT_CMD_UIO,
        0xC0,
        0,
        0,
        data_flags,
        USBAT_UIO_READ);

    US_DEBUGP("usbat_read_user_io: UIO register reads %02X\n", (unsigned short) (*data_flags));

    return result;
}

/*
 * Write to the User IO register
 */
static int usbat_write_user_io(struct us_data *us,
                   unsigned char enable_flags,
                   unsigned char data_flags)
{
    return usb_stor_ctrl_transfer(us,
        us->send_ctrl_pipe,
        USBAT_CMD_UIO,
        0x40,
        short_pack(enable_flags, data_flags),
        0,
        NULL,
        USBAT_UIO_WRITE);
}

/*
 * Reset the device
 * Often needed on media change.
 */
static int usbat_device_reset(struct us_data *us)
{
    int rc;

    /*
     * Reset peripheral, enable peripheral control signals
     * (bring reset signal up)
     */
    rc = usbat_write_user_io(us,
                             USBAT_UIO_DRVRST | USBAT_UIO_OE1 | USBAT_UIO_OE0,
                             USBAT_UIO_EPAD | USBAT_UIO_1);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;
            
    /*
     * Enable peripheral control signals
     * (bring reset signal down)
     */
    rc = usbat_write_user_io(us,
                             USBAT_UIO_OE1  | USBAT_UIO_OE0,
                             USBAT_UIO_EPAD | USBAT_UIO_1);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Enable card detect
 */
static int usbat_device_enable_cdt(struct us_data *us)
{
    int rc;

    /* Enable peripheral control signals and card detect */
    rc = usbat_write_user_io(us,
                             USBAT_UIO_ACKD | USBAT_UIO_OE1  | USBAT_UIO_OE0,
                             USBAT_UIO_EPAD | USBAT_UIO_1);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Determine if media is present.
 */
static int usbat_flash_check_media_present(unsigned char *uio)
{
    if (*uio & USBAT_UIO_UI0) {
        US_DEBUGP("usbat_flash_check_media_present: no media detected\n");
        return USBAT_FLASH_MEDIA_NONE;
    }

    return USBAT_FLASH_MEDIA_CF;
}

/*
 * Determine if media has changed since last operation
 */
static int usbat_flash_check_media_changed(unsigned char *uio)
{
    if (*uio & USBAT_UIO_0) {
        US_DEBUGP("usbat_flash_check_media_changed: media change detected\n");
        return USBAT_FLASH_MEDIA_CHANGED;
    }

    return USBAT_FLASH_MEDIA_SAME;
}

/*
 * Check for media change / no media and handle the situation appropriately
 */
static int usbat_flash_check_media(struct us_data *us,
                   struct usbat_info *info)
{
    int rc;
    unsigned char *uio = us->iobuf;

    rc = usbat_read_user_io(us, uio);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    /* Check for media existence */
    rc = usbat_flash_check_media_present(uio);
    if (rc == USBAT_FLASH_MEDIA_NONE) {
        info->sense_key = 0x02;
        info->sense_asc = 0x3A;
        info->sense_ascq = 0x00;
        return USB_STOR_TRANSPORT_FAILED;
    }

    /* Check for media change */
    rc = usbat_flash_check_media_changed(uio);
    if (rc == USBAT_FLASH_MEDIA_CHANGED) {

        /* Reset and re-enable card detect */
        rc = usbat_device_reset(us);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;
        rc = usbat_device_enable_cdt(us);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;

        msleep(50);

        rc = usbat_read_user_io(us, uio);
        if (rc != USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;
        
        info->sense_key = UNIT_ATTENTION;
        info->sense_asc = 0x28;
        info->sense_ascq = 0x00;
        return USB_STOR_TRANSPORT_FAILED;
    }

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Determine whether we are controlling a flash-based reader/writer,
 * or a HP8200-based CD drive.
 * Sets transport functions as appropriate.
 */
static int usbat_identify_device(struct us_data *us,
                 struct usbat_info *info)
{
    int rc;
    unsigned char status;

    if (!us || !info)
        return USB_STOR_TRANSPORT_ERROR;

    rc = usbat_device_reset(us);
    if (rc != USB_STOR_TRANSPORT_GOOD)
        return rc;
    msleep(500);

    /*
     * In attempt to distinguish between HP CDRW's and Flash readers, we now
     * execute the IDENTIFY PACKET DEVICE command. On ATA devices (i.e. flash
     * readers), this command should fail with error. On ATAPI devices (i.e.
     * CDROM drives), it should succeed.
     */
    rc = usbat_write(us, USBAT_ATA, USBAT_ATA_CMD, 0xA1);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    rc = usbat_get_status(us, &status);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    /* Check for error bit, or if the command 'fell through' */
    if (status == 0xA1 || !(status & 0x01)) {
        /* Device is HP 8200 */
        US_DEBUGP("usbat_identify_device: Detected HP8200 CDRW\n");
        info->devicetype = USBAT_DEV_HP8200;
    } else {
        /* Device is a CompactFlash reader/writer */
        US_DEBUGP("usbat_identify_device: Detected Flash reader/writer\n");
        info->devicetype = USBAT_DEV_FLASH;
    }

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Set the transport function based on the device type
 */
static int usbat_set_transport(struct us_data *us,
                   struct usbat_info *info,
                   int devicetype)
{

    if (!info->devicetype)
        info->devicetype = devicetype;

    if (!info->devicetype)
        usbat_identify_device(us, info);

    switch (info->devicetype) {
    default:
        return USB_STOR_TRANSPORT_ERROR;

    case  USBAT_DEV_HP8200:
        us->transport = usbat_hp8200e_transport;
        break;

    case USBAT_DEV_FLASH:
        us->transport = usbat_flash_transport;
        break;
    }

    return 0;
}

/*
 * Read the media capacity
 */
static int usbat_flash_get_sector_count(struct us_data *us,
                    struct usbat_info *info)
{
    unsigned char registers[3] = {
        USBAT_ATA_SECCNT,
        USBAT_ATA_DEVICE,
        USBAT_ATA_CMD,
    };
    unsigned char  command[3] = { 0x01, 0xA0, 0xEC };
    unsigned char *reply;
    unsigned char status;
    int rc;

    if (!us || !info)
        return USB_STOR_TRANSPORT_ERROR;

    reply = kmalloc(512, GFP_NOIO);
    if (!reply)
        return USB_STOR_TRANSPORT_ERROR;

    /* ATA command : IDENTIFY DEVICE */
    rc = usbat_multiple_write(us, registers, command, 3);
    if (rc != USB_STOR_XFER_GOOD) {
        US_DEBUGP("usbat_flash_get_sector_count: Gah! identify_device failed\n");
        rc = USB_STOR_TRANSPORT_ERROR;
        goto leave;
    }

    /* Read device status */
    if (usbat_get_status(us, &status) != USB_STOR_XFER_GOOD) {
        rc = USB_STOR_TRANSPORT_ERROR;
        goto leave;
    }

    msleep(100);

    /* Read the device identification data */
    rc = usbat_read_block(us, reply, 512, 0);
    if (rc != USB_STOR_TRANSPORT_GOOD)
        goto leave;

    info->sectors = ((u32)(reply[117]) << 24) |
        ((u32)(reply[116]) << 16) |
        ((u32)(reply[115]) <<  8) |
        ((u32)(reply[114])      );

    rc = USB_STOR_TRANSPORT_GOOD;

 leave:
    kfree(reply);
    return rc;
}

/*
 * Read data from device
 */
static int usbat_flash_read_data(struct us_data *us,
                                 struct usbat_info *info,
                                 u32 sector,
                                 u32 sectors)
{
    unsigned char registers[7] = {
        USBAT_ATA_FEATURES,
        USBAT_ATA_SECCNT,
        USBAT_ATA_SECNUM,
        USBAT_ATA_LBA_ME,
        USBAT_ATA_LBA_HI,
        USBAT_ATA_DEVICE,
        USBAT_ATA_STATUS,
    };
    unsigned char command[7];
    unsigned char *buffer;
    unsigned char  thistime;
    unsigned int totallen, alloclen;
    int len, result;
    unsigned int sg_offset = 0;
    struct scatterlist *sg = NULL;

    result = usbat_flash_check_media(us, info);
    if (result != USB_STOR_TRANSPORT_GOOD)
        return result;

    /*
     * we're working in LBA mode.  according to the ATA spec,
     * we can support up to 28-bit addressing.  I don't know if Jumpshot
     * supports beyond 24-bit addressing.  It's kind of hard to test
     * since it requires > 8GB CF card.
     */

    if (sector > 0x0FFFFFFF)
        return USB_STOR_TRANSPORT_ERROR;

    totallen = sectors * info->ssize;

    /*
     * Since we don't read more than 64 KB at a time, we have to create
     * a bounce buffer and move the data a piece at a time between the
     * bounce buffer and the actual transfer buffer.
     */

    alloclen = min(totallen, 65536u);
    buffer = kmalloc(alloclen, GFP_NOIO);
    if (buffer == NULL)
        return USB_STOR_TRANSPORT_ERROR;

    do {
        /*
         * loop, never allocate or transfer more than 64k at once
         * (min(128k, 255*info->ssize) is the real limit)
         */
        len = min(totallen, alloclen);
        thistime = (len / info->ssize) & 0xff;
 
        /* ATA command 0x20 (READ SECTORS) */
        usbat_pack_ata_sector_cmd(command, thistime, sector, 0x20);

        /* Write/execute ATA read command */
        result = usbat_multiple_write(us, registers, command, 7);
        if (result != USB_STOR_TRANSPORT_GOOD)
            goto leave;

        /* Read the data we just requested */
        result = usbat_read_blocks(us, buffer, len, 0);
        if (result != USB_STOR_TRANSPORT_GOOD)
            goto leave;
     
        US_DEBUGP("usbat_flash_read_data:  %d bytes\n", len);
    
        /* Store the data in the transfer buffer */
        usb_stor_access_xfer_buf(buffer, len, us->srb,
                     &sg, &sg_offset, TO_XFER_BUF);

        sector += thistime;
        totallen -= len;
    } while (totallen > 0);

    kfree(buffer);
    return USB_STOR_TRANSPORT_GOOD;

leave:
    kfree(buffer);
    return USB_STOR_TRANSPORT_ERROR;
}

/*
 * Write data to device
 */
static int usbat_flash_write_data(struct us_data *us,
                                  struct usbat_info *info,
                                  u32 sector,
                                  u32 sectors)
{
    unsigned char registers[7] = {
        USBAT_ATA_FEATURES,
        USBAT_ATA_SECCNT,
        USBAT_ATA_SECNUM,
        USBAT_ATA_LBA_ME,
        USBAT_ATA_LBA_HI,
        USBAT_ATA_DEVICE,
        USBAT_ATA_STATUS,
    };
    unsigned char command[7];
    unsigned char *buffer;
    unsigned char  thistime;
    unsigned int totallen, alloclen;
    int len, result;
    unsigned int sg_offset = 0;
    struct scatterlist *sg = NULL;

    result = usbat_flash_check_media(us, info);
    if (result != USB_STOR_TRANSPORT_GOOD)
        return result;

    /*
     * we're working in LBA mode.  according to the ATA spec,
     * we can support up to 28-bit addressing.  I don't know if the device
     * supports beyond 24-bit addressing.  It's kind of hard to test
     * since it requires > 8GB media.
     */

    if (sector > 0x0FFFFFFF)
        return USB_STOR_TRANSPORT_ERROR;

    totallen = sectors * info->ssize;

    /*
     * Since we don't write more than 64 KB at a time, we have to create
     * a bounce buffer and move the data a piece at a time between the
     * bounce buffer and the actual transfer buffer.
     */

    alloclen = min(totallen, 65536u);
    buffer = kmalloc(alloclen, GFP_NOIO);
    if (buffer == NULL)
        return USB_STOR_TRANSPORT_ERROR;

    do {
        /*
         * loop, never allocate or transfer more than 64k at once
         * (min(128k, 255*info->ssize) is the real limit)
         */
        len = min(totallen, alloclen);
        thistime = (len / info->ssize) & 0xff;

        /* Get the data from the transfer buffer */
        usb_stor_access_xfer_buf(buffer, len, us->srb,
                     &sg, &sg_offset, FROM_XFER_BUF);

        /* ATA command 0x30 (WRITE SECTORS) */
        usbat_pack_ata_sector_cmd(command, thistime, sector, 0x30);

        /* Write/execute ATA write command */
        result = usbat_multiple_write(us, registers, command, 7);
        if (result != USB_STOR_TRANSPORT_GOOD)
            goto leave;

        /* Write the data */
        result = usbat_write_blocks(us, buffer, len, 0);
        if (result != USB_STOR_TRANSPORT_GOOD)
            goto leave;

        sector += thistime;
        totallen -= len;
    } while (totallen > 0);

    kfree(buffer);
    return result;

leave:
    kfree(buffer);
    return USB_STOR_TRANSPORT_ERROR;
}

/*
 * Squeeze a potentially huge (> 65535 byte) read10 command into
 * a little ( <= 65535 byte) ATAPI pipe
 */
static int usbat_hp8200e_handle_read10(struct us_data *us,
                       unsigned char *registers,
                       unsigned char *data,
                       struct scsi_cmnd *srb)
{
    int result = USB_STOR_TRANSPORT_GOOD;
    unsigned char *buffer;
    unsigned int len;
    unsigned int sector;
    unsigned int sg_offset = 0;
    struct scatterlist *sg = NULL;

    US_DEBUGP("handle_read10: transfersize %d\n",
        srb->transfersize);

    if (scsi_bufflen(srb) < 0x10000) {

        result = usbat_hp8200e_rw_block_test(us, USBAT_ATA, 
            registers, data, 19,
            USBAT_ATA_DATA, USBAT_ATA_STATUS, 0xFD,
            (USBAT_QUAL_FCQ | USBAT_QUAL_ALQ),
            DMA_FROM_DEVICE,
            scsi_sglist(srb),
            scsi_bufflen(srb), scsi_sg_count(srb), 1);

        return result;
    }

    /*
     * Since we're requesting more data than we can handle in
     * a single read command (max is 64k-1), we will perform
     * multiple reads, but each read must be in multiples of
     * a sector.  Luckily the sector size is in srb->transfersize
     * (see linux/drivers/scsi/sr.c).
     */

    if (data[7+0] == GPCMD_READ_CD) {
        len = short_pack(data[7+9], data[7+8]);
        len <<= 16;
        len |= data[7+7];
        US_DEBUGP("handle_read10: GPCMD_READ_CD: len %d\n", len);
        srb->transfersize = scsi_bufflen(srb)/len;
    }

    if (!srb->transfersize)  {
        srb->transfersize = 2048; /* A guess */
        US_DEBUGP("handle_read10: transfersize 0, forcing %d\n",
            srb->transfersize);
    }

    /*
     * Since we only read in one block at a time, we have to create
     * a bounce buffer and move the data a piece at a time between the
     * bounce buffer and the actual transfer buffer.
     */

    len = (65535/srb->transfersize) * srb->transfersize;
    US_DEBUGP("Max read is %d bytes\n", len);
    len = min(len, scsi_bufflen(srb));
    buffer = kmalloc(len, GFP_NOIO);
    if (buffer == NULL) /* bloody hell! */
        return USB_STOR_TRANSPORT_FAILED;
    sector = short_pack(data[7+3], data[7+2]);
    sector <<= 16;
    sector |= short_pack(data[7+5], data[7+4]);
    transferred = 0;

    while (transferred != scsi_bufflen(srb)) {

        if (len > scsi_bufflen(srb) - transferred)
            len = scsi_bufflen(srb) - transferred;

        data[3] = len&0xFF;       /* (cylL) = expected length (L) */
        data[4] = (len>>8)&0xFF;  /* (cylH) = expected length (H) */

        /* Fix up the SCSI command sector and num sectors */

        data[7+2] = MSB_of(sector>>16); /* SCSI command sector */
        data[7+3] = LSB_of(sector>>16);
        data[7+4] = MSB_of(sector&0xFFFF);
        data[7+5] = LSB_of(sector&0xFFFF);
        if (data[7+0] == GPCMD_READ_CD)
            data[7+6] = 0;
        data[7+7] = MSB_of(len / srb->transfersize); /* SCSI command */
        data[7+8] = LSB_of(len / srb->transfersize); /* num sectors */

        result = usbat_hp8200e_rw_block_test(us, USBAT_ATA, 
            registers, data, 19,
            USBAT_ATA_DATA, USBAT_ATA_STATUS, 0xFD, 
            (USBAT_QUAL_FCQ | USBAT_QUAL_ALQ),
            DMA_FROM_DEVICE,
            buffer,
            len, 0, 1);

        if (result != USB_STOR_TRANSPORT_GOOD)
            break;

        /* Store the data in the transfer buffer */
        usb_stor_access_xfer_buf(buffer, len, srb,
                 &sg, &sg_offset, TO_XFER_BUF);

        /* Update the amount transferred and the sector number */

        transferred += len;
        sector += len / srb->transfersize;

    } /* while transferred != scsi_bufflen(srb) */

    kfree(buffer);
    return result;
}

static int usbat_select_and_test_registers(struct us_data *us)
{
    int selector;
    unsigned char *status = us->iobuf;

    /* try device = master, then device = slave. */
    for (selector = 0xA0; selector <= 0xB0; selector += 0x10) {
        if (usbat_write(us, USBAT_ATA, USBAT_ATA_DEVICE, selector) !=
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_read(us, USBAT_ATA, USBAT_ATA_STATUS, status) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_read(us, USBAT_ATA, USBAT_ATA_DEVICE, status) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_read(us, USBAT_ATA, USBAT_ATA_LBA_ME, status) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_read(us, USBAT_ATA, USBAT_ATA_LBA_HI, status) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_write(us, USBAT_ATA, USBAT_ATA_LBA_ME, 0x55) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_write(us, USBAT_ATA, USBAT_ATA_LBA_HI, 0xAA) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_read(us, USBAT_ATA, USBAT_ATA_LBA_ME, status) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        if (usbat_read(us, USBAT_ATA, USBAT_ATA_LBA_ME, status) != 
                USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;
    }

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Initialize the USBAT processor and the storage device
 */
static int init_usbat(struct us_data *us, int devicetype)
{
    int rc;
    struct usbat_info *info;
    unsigned char subcountH = USBAT_ATA_LBA_HI;
    unsigned char subcountL = USBAT_ATA_LBA_ME;
    unsigned char *status = us->iobuf;

    us->extra = kzalloc(sizeof(struct usbat_info), GFP_NOIO);
    if (!us->extra) {
        US_DEBUGP("init_usbat: Gah! Can't allocate storage for usbat info struct!\n");
        return 1;
    }
    info = (struct usbat_info *) (us->extra);

    /* Enable peripheral control signals */
    rc = usbat_write_user_io(us,
                 USBAT_UIO_OE1 | USBAT_UIO_OE0,
                 USBAT_UIO_EPAD | USBAT_UIO_1);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("INIT 1\n");

    msleep(2000);

    rc = usbat_read_user_io(us, status);
    if (rc != USB_STOR_TRANSPORT_GOOD)
        return rc;

    US_DEBUGP("INIT 2\n");

    rc = usbat_read_user_io(us, status);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    rc = usbat_read_user_io(us, status);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("INIT 3\n");

    rc = usbat_select_and_test_registers(us);
    if (rc != USB_STOR_TRANSPORT_GOOD)
        return rc;

    US_DEBUGP("INIT 4\n");

    rc = usbat_read_user_io(us, status);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("INIT 5\n");

    /* Enable peripheral control signals and card detect */
    rc = usbat_device_enable_cdt(us);
    if (rc != USB_STOR_TRANSPORT_GOOD)
        return rc;

    US_DEBUGP("INIT 6\n");

    rc = usbat_read_user_io(us, status);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("INIT 7\n");

    msleep(1400);

    rc = usbat_read_user_io(us, status);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("INIT 8\n");

    rc = usbat_select_and_test_registers(us);
    if (rc != USB_STOR_TRANSPORT_GOOD)
        return rc;

    US_DEBUGP("INIT 9\n");

    /* At this point, we need to detect which device we are using */
    if (usbat_set_transport(us, info, devicetype))
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("INIT 10\n");

    if (usbat_get_device_type(us) == USBAT_DEV_FLASH) { 
        subcountH = 0x02;
        subcountL = 0x00;
    }
    rc = usbat_set_shuttle_features(us, (USBAT_FEAT_ETEN | USBAT_FEAT_ET2 | USBAT_FEAT_ET1),
                                    0x00, 0x88, 0x08, subcountH, subcountL);
    if (rc != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUGP("INIT 11\n");

    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Transport for the HP 8200e
 */
static int usbat_hp8200e_transport(struct scsi_cmnd *srb, struct us_data *us)
{
    int result;
    unsigned char *status = us->iobuf;
    unsigned char registers[32];
    unsigned char data[32];
    unsigned int len;
    int i;

    len = scsi_bufflen(srb);

    /* Send A0 (ATA PACKET COMMAND).
       Note: I guess we're never going to get any of the ATA
       commands... just ATA Packet Commands.
     */

    registers[0] = USBAT_ATA_FEATURES;
    registers[1] = USBAT_ATA_SECCNT;
    registers[2] = USBAT_ATA_SECNUM;
    registers[3] = USBAT_ATA_LBA_ME;
    registers[4] = USBAT_ATA_LBA_HI;
    registers[5] = USBAT_ATA_DEVICE;
    registers[6] = USBAT_ATA_CMD;
    data[0] = 0x00;
    data[1] = 0x00;
    data[2] = 0x00;
    data[3] = len&0xFF;         /* (cylL) = expected length (L) */
    data[4] = (len>>8)&0xFF;    /* (cylH) = expected length (H) */
    data[5] = 0xB0;         /* (device sel) = slave */
    data[6] = 0xA0;         /* (command) = ATA PACKET COMMAND */

    for (i=7; i<19; i++) {
        registers[i] = 0x10;
        data[i] = (i-7 >= srb->cmd_len) ? 0 : srb->cmnd[i-7];
    }

    result = usbat_get_status(us, status);
    US_DEBUGP("Status = %02X\n", *status);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;
    if (srb->cmnd[0] == TEST_UNIT_READY)
        transferred = 0;

    if (srb->sc_data_direction == DMA_TO_DEVICE) {

        result = usbat_hp8200e_rw_block_test(us, USBAT_ATA, 
            registers, data, 19,
            USBAT_ATA_DATA, USBAT_ATA_STATUS, 0xFD,
            (USBAT_QUAL_FCQ | USBAT_QUAL_ALQ),
            DMA_TO_DEVICE,
            scsi_sglist(srb),
            len, scsi_sg_count(srb), 10);

        if (result == USB_STOR_TRANSPORT_GOOD) {
            transferred += len;
            US_DEBUGP("Wrote %08X bytes\n", transferred);
        }

        return result;

    } else if (srb->cmnd[0] == READ_10 ||
           srb->cmnd[0] == GPCMD_READ_CD) {

        return usbat_hp8200e_handle_read10(us, registers, data, srb);

    }

    if (len > 0xFFFF) {
        US_DEBUGP("Error: len = %08X... what do I do now?\n",
            len);
        return USB_STOR_TRANSPORT_ERROR;
    }

    result = usbat_multiple_write(us, registers, data, 7);

    if (result != USB_STOR_TRANSPORT_GOOD)
        return result;

    /*
     * Write the 12-byte command header.
     *
     * If the command is BLANK then set the timer for 75 minutes.
     * Otherwise set it for 10 minutes.
     *
     * NOTE: THE 8200 DOCUMENTATION STATES THAT BLANKING A CDRW
     * AT SPEED 4 IS UNRELIABLE!!!
     */

    result = usbat_write_block(us, USBAT_ATA, srb->cmnd, 12,
                   srb->cmnd[0] == GPCMD_BLANK ? 75 : 10, 0);

    if (result != USB_STOR_TRANSPORT_GOOD)
        return result;

    /* If there is response data to be read in then do it here. */

    if (len != 0 && (srb->sc_data_direction == DMA_FROM_DEVICE)) {

        /* How many bytes to read in? Check cylL register */

        if (usbat_read(us, USBAT_ATA, USBAT_ATA_LBA_ME, status) != 
                USB_STOR_XFER_GOOD) {
            return USB_STOR_TRANSPORT_ERROR;
        }

        if (len > 0xFF) { /* need to read cylH also */
            len = *status;
            if (usbat_read(us, USBAT_ATA, USBAT_ATA_LBA_HI, status) !=
                    USB_STOR_XFER_GOOD) {
                return USB_STOR_TRANSPORT_ERROR;
            }
            len += ((unsigned int) *status)<<8;
        }
        else
            len = *status;


        result = usbat_read_block(us, scsi_sglist(srb), len,
                                               scsi_sg_count(srb));
    }

    return result;
}

/*
 * Transport for USBAT02-based CompactFlash and similar storage devices
 */
static int usbat_flash_transport(struct scsi_cmnd * srb, struct us_data *us)
{
    int rc;
    struct usbat_info *info = (struct usbat_info *) (us->extra);
    unsigned long block, blocks;
    unsigned char *ptr = us->iobuf;
    static unsigned char inquiry_response[36] = {
        0x00, 0x80, 0x00, 0x01, 0x1F, 0x00, 0x00, 0x00
    };

    if (srb->cmnd[0] == INQUIRY) {
        US_DEBUGP("usbat_flash_transport: INQUIRY. Returning bogus response.\n");
        memcpy(ptr, inquiry_response, sizeof(inquiry_response));
        fill_inquiry_response(us, ptr, 36);
        return USB_STOR_TRANSPORT_GOOD;
    }

    if (srb->cmnd[0] == READ_CAPACITY) {
        rc = usbat_flash_check_media(us, info);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;

        rc = usbat_flash_get_sector_count(us, info);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;

        /* hard coded 512 byte sectors as per ATA spec */
        info->ssize = 0x200;
        US_DEBUGP("usbat_flash_transport: READ_CAPACITY: %ld sectors, %ld bytes per sector\n",
              info->sectors, info->ssize);

        /*
         * build the reply
         * note: must return the sector number of the last sector,
         * *not* the total number of sectors
         */
        ((__be32 *) ptr)[0] = cpu_to_be32(info->sectors - 1);
        ((__be32 *) ptr)[1] = cpu_to_be32(info->ssize);
        usb_stor_set_xfer_buf(ptr, 8, srb);

        return USB_STOR_TRANSPORT_GOOD;
    }

    if (srb->cmnd[0] == MODE_SELECT_10) {
        US_DEBUGP("usbat_flash_transport:  Gah! MODE_SELECT_10.\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    if (srb->cmnd[0] == READ_10) {
        block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

        blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));

        US_DEBUGP("usbat_flash_transport:  READ_10: read block 0x%04lx  count %ld\n", block, blocks);
        return usbat_flash_read_data(us, info, block, blocks);
    }

    if (srb->cmnd[0] == READ_12) {
        /*
         * I don't think we'll ever see a READ_12 but support it anyway
         */
        block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

        blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
                 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));

        US_DEBUGP("usbat_flash_transport: READ_12: read block 0x%04lx  count %ld\n", block, blocks);
        return usbat_flash_read_data(us, info, block, blocks);
    }

    if (srb->cmnd[0] == WRITE_10) {
        block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

        blocks = ((u32)(srb->cmnd[7]) << 8) | ((u32)(srb->cmnd[8]));

        US_DEBUGP("usbat_flash_transport: WRITE_10: write block 0x%04lx  count %ld\n", block, blocks);
        return usbat_flash_write_data(us, info, block, blocks);
    }

    if (srb->cmnd[0] == WRITE_12) {
        /*
         * I don't think we'll ever see a WRITE_12 but support it anyway
         */
        block = ((u32)(srb->cmnd[2]) << 24) | ((u32)(srb->cmnd[3]) << 16) |
                ((u32)(srb->cmnd[4]) <<  8) | ((u32)(srb->cmnd[5]));

        blocks = ((u32)(srb->cmnd[6]) << 24) | ((u32)(srb->cmnd[7]) << 16) |
                 ((u32)(srb->cmnd[8]) <<  8) | ((u32)(srb->cmnd[9]));

        US_DEBUGP("usbat_flash_transport: WRITE_12: write block 0x%04lx  count %ld\n", block, blocks);
        return usbat_flash_write_data(us, info, block, blocks);
    }


    if (srb->cmnd[0] == TEST_UNIT_READY) {
        US_DEBUGP("usbat_flash_transport: TEST_UNIT_READY.\n");

        rc = usbat_flash_check_media(us, info);
        if (rc != USB_STOR_TRANSPORT_GOOD)
            return rc;

        return usbat_check_status(us);
    }

    if (srb->cmnd[0] == REQUEST_SENSE) {
        US_DEBUGP("usbat_flash_transport: REQUEST_SENSE.\n");

        memset(ptr, 0, 18);
        ptr[0] = 0xF0;
        ptr[2] = info->sense_key;
        ptr[7] = 11;
        ptr[12] = info->sense_asc;
        ptr[13] = info->sense_ascq;
        usb_stor_set_xfer_buf(ptr, 18, srb);

        return USB_STOR_TRANSPORT_GOOD;
    }

    if (srb->cmnd[0] == ALLOW_MEDIUM_REMOVAL) {
        /*
         * sure.  whatever.  not like we can stop the user from popping
         * the media out of the device (no locking doors, etc)
         */
        return USB_STOR_TRANSPORT_GOOD;
    }

    US_DEBUGP("usbat_flash_transport: Gah! Unknown command: %d (0x%x)\n",
              srb->cmnd[0], srb->cmnd[0]);
    info->sense_key = 0x05;
    info->sense_asc = 0x20;
    info->sense_ascq = 0x00;
    return USB_STOR_TRANSPORT_FAILED;
}

static int init_usbat_cd(struct us_data *us)
{
    return init_usbat(us, USBAT_DEV_HP8200);
}

static int init_usbat_flash(struct us_data *us)
{
    return init_usbat(us, USBAT_DEV_FLASH);
}

static int usbat_probe(struct usb_interface *intf,
             const struct usb_device_id *id)
{
    struct us_data *us;
    int result;

    result = usb_stor_probe1(&us, intf, id,
            (id - usbat_usb_ids) + usbat_unusual_dev_list);
    if (result)
        return result;

    /* The actual transport will be determined later by the
     * initialization routine; this is just a placeholder.
     */
    us->transport_name = "Shuttle USBAT";
    us->transport = usbat_flash_transport;
    us->transport_reset = usb_stor_CB_reset;
    us->max_lun = 1;

    result = usb_stor_probe2(us);
    return result;
}

static struct usb_driver usbat_driver = {
    .name =     "ums-usbat",
    .probe =    usbat_probe,
    .disconnect =   usb_stor_disconnect,
    .suspend =  usb_stor_suspend,
    .resume =   usb_stor_resume,
    .reset_resume = usb_stor_reset_resume,
    .pre_reset =    usb_stor_pre_reset,
    .post_reset =   usb_stor_post_reset,
    .id_table = usbat_usb_ids,
    .soft_unbind =  1,
    .no_dynamic_id = 1,
};

module_usb_driver(usbat_driver);