freecom.c

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/* Driver for Freecom USB/IDE adaptor
 *
 * Freecom v0.1:
 *
 * First release
 *
 * Current development and maintenance by:
 *   (C) 2000 David Brown <[email protected]>
 *
 * 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.
 *
 * This driver was developed with information provided in FREECOM's USB
 * Programmers Reference Guide.  For further information contact Freecom
 * (http://www.freecom.de/)
 */

#include <linux/module.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 Freecom USB/IDE adaptor");
MODULE_AUTHOR("David Brown <[email protected]>");
MODULE_LICENSE("GPL");

#ifdef CONFIG_USB_STORAGE_DEBUG
static void pdump (void *, int);
#endif

/* Bits of HD_STATUS */
#define ERR_STAT        0x01
#define DRQ_STAT        0x08

/* All of the outgoing packets are 64 bytes long. */
struct freecom_cb_wrap {
    u8    Type;     /* Command type. */
    u8    Timeout;      /* Timeout in seconds. */
    u8    Atapi[12];    /* An ATAPI packet. */
    u8    Filler[50];   /* Padding Data. */
};

struct freecom_xfer_wrap {
    u8    Type;     /* Command type. */
    u8    Timeout;      /* Timeout in seconds. */
    __le32   Count;     /* Number of bytes to transfer. */
    u8    Pad[58];
} __attribute__ ((packed));

struct freecom_ide_out {
    u8    Type;     /* Type + IDE register. */
    u8    Pad;
    __le16   Value;     /* Value to write. */
    u8    Pad2[60];
};

struct freecom_ide_in {
    u8    Type;     /* Type | IDE register. */
    u8    Pad[63];
};

struct freecom_status {
    u8    Status;
    u8    Reason;
    __le16   Count;
    u8    Pad[60];
};

/* Freecom stuffs the interrupt status in the INDEX_STAT bit of the ide
 * register. */
#define FCM_INT_STATUS      0x02 /* INDEX_STAT */
#define FCM_STATUS_BUSY     0x80

/* These are the packet types.  The low bit indicates that this command
 * should wait for an interrupt. */
#define FCM_PACKET_ATAPI    0x21
#define FCM_PACKET_STATUS   0x20

/* Receive data from the IDE interface.  The ATAPI packet has already
 * waited, so the data should be immediately available. */
#define FCM_PACKET_INPUT    0x81

/* Send data to the IDE interface. */
#define FCM_PACKET_OUTPUT   0x01

/* Write a value to an ide register.  Or the ide register to write after
 * munging the address a bit. */
#define FCM_PACKET_IDE_WRITE    0x40
#define FCM_PACKET_IDE_READ 0xC0

/* All packets (except for status) are 64 bytes long. */
#define FCM_PACKET_LENGTH       64
#define FCM_STATUS_PACKET_LENGTH    4

static int init_freecom(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 freecom_usb_ids[] = {
#   include "unusual_freecom.h"
    { }     /* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, freecom_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 freecom_unusual_dev_list[] = {
#   include "unusual_freecom.h"
    { }     /* Terminating entry */
};

#undef UNUSUAL_DEV

static int
freecom_readdata (struct scsi_cmnd *srb, struct us_data *us,
        unsigned int ipipe, unsigned int opipe, int count)
{
    struct freecom_xfer_wrap *fxfr =
        (struct freecom_xfer_wrap *) us->iobuf;
    int result;

    fxfr->Type = FCM_PACKET_INPUT | 0x00;
    fxfr->Timeout = 0;    /* Short timeout for debugging. */
    fxfr->Count = cpu_to_le32 (count);
    memset (fxfr->Pad, 0, sizeof (fxfr->Pad));

    US_DEBUGP("Read data Freecom! (c=%d)\n", count);

    /* Issue the transfer command. */
    result = usb_stor_bulk_transfer_buf (us, opipe, fxfr,
            FCM_PACKET_LENGTH, NULL);
    if (result != USB_STOR_XFER_GOOD) {
        US_DEBUGP ("Freecom readdata transport error\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    /* Now transfer all of our blocks. */
    US_DEBUGP("Start of read\n");
    result = usb_stor_bulk_srb(us, ipipe, srb);
    US_DEBUGP("freecom_readdata done!\n");

    if (result > USB_STOR_XFER_SHORT)
        return USB_STOR_TRANSPORT_ERROR;
    return USB_STOR_TRANSPORT_GOOD;
}

static int
freecom_writedata (struct scsi_cmnd *srb, struct us_data *us,
        int unsigned ipipe, unsigned int opipe, int count)
{
    struct freecom_xfer_wrap *fxfr =
        (struct freecom_xfer_wrap *) us->iobuf;
    int result;

    fxfr->Type = FCM_PACKET_OUTPUT | 0x00;
    fxfr->Timeout = 0;    /* Short timeout for debugging. */
    fxfr->Count = cpu_to_le32 (count);
    memset (fxfr->Pad, 0, sizeof (fxfr->Pad));

    US_DEBUGP("Write data Freecom! (c=%d)\n", count);

    /* Issue the transfer command. */
    result = usb_stor_bulk_transfer_buf (us, opipe, fxfr,
            FCM_PACKET_LENGTH, NULL);
    if (result != USB_STOR_XFER_GOOD) {
        US_DEBUGP ("Freecom writedata transport error\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    /* Now transfer all of our blocks. */
    US_DEBUGP("Start of write\n");
    result = usb_stor_bulk_srb(us, opipe, srb);

    US_DEBUGP("freecom_writedata done!\n");
    if (result > USB_STOR_XFER_SHORT)
        return USB_STOR_TRANSPORT_ERROR;
    return USB_STOR_TRANSPORT_GOOD;
}

/*
 * Transport for the Freecom USB/IDE adaptor.
 *
 */
static int freecom_transport(struct scsi_cmnd *srb, struct us_data *us)
{
    struct freecom_cb_wrap *fcb;
    struct freecom_status  *fst;
    unsigned int ipipe, opipe;      /* We need both pipes. */
    int result;
    unsigned int partial;
    int length;

    fcb = (struct freecom_cb_wrap *) us->iobuf;
    fst = (struct freecom_status *) us->iobuf;

    US_DEBUGP("Freecom TRANSPORT STARTED\n");

    /* Get handles for both transports. */
    opipe = us->send_bulk_pipe;
    ipipe = us->recv_bulk_pipe;

    /* The ATAPI Command always goes out first. */
    fcb->Type = FCM_PACKET_ATAPI | 0x00;
    fcb->Timeout = 0;
    memcpy (fcb->Atapi, srb->cmnd, 12);
    memset (fcb->Filler, 0, sizeof (fcb->Filler));

    US_DEBUG(pdump (srb->cmnd, 12));

    /* Send it out. */
    result = usb_stor_bulk_transfer_buf (us, opipe, fcb,
            FCM_PACKET_LENGTH, NULL);

    /* The Freecom device will only fail if there is something wrong in
     * USB land.  It returns the status in its own registers, which
     * come back in the bulk pipe. */
    if (result != USB_STOR_XFER_GOOD) {
        US_DEBUGP ("freecom transport error\n");
        return USB_STOR_TRANSPORT_ERROR;
    }

    /* There are times we can optimize out this status read, but it
     * doesn't hurt us to always do it now. */
    result = usb_stor_bulk_transfer_buf (us, ipipe, fst,
            FCM_STATUS_PACKET_LENGTH, &partial);
    US_DEBUGP("foo Status result %d %u\n", result, partial);
    if (result != USB_STOR_XFER_GOOD)
        return USB_STOR_TRANSPORT_ERROR;

    US_DEBUG(pdump ((void *) fst, partial));

    /* The firmware will time-out commands after 20 seconds. Some commands
     * can legitimately take longer than this, so we use a different
     * command that only waits for the interrupt and then sends status,
     * without having to send a new ATAPI command to the device.
     *
     * NOTE: There is some indication that a data transfer after a timeout
     * may not work, but that is a condition that should never happen.
     */
    while (fst->Status & FCM_STATUS_BUSY) {
        US_DEBUGP("20 second USB/ATAPI bridge TIMEOUT occurred!\n");
        US_DEBUGP("fst->Status is %x\n", fst->Status);

        /* Get the status again */
        fcb->Type = FCM_PACKET_STATUS;
        fcb->Timeout = 0;
        memset (fcb->Atapi, 0, sizeof(fcb->Atapi));
        memset (fcb->Filler, 0, sizeof (fcb->Filler));

        /* Send it out. */
        result = usb_stor_bulk_transfer_buf (us, opipe, fcb,
                FCM_PACKET_LENGTH, NULL);

        /* The Freecom device will only fail if there is something
         * wrong in USB land.  It returns the status in its own
         * registers, which come back in the bulk pipe.
         */
        if (result != USB_STOR_XFER_GOOD) {
            US_DEBUGP ("freecom transport error\n");
            return USB_STOR_TRANSPORT_ERROR;
        }

        /* get the data */
        result = usb_stor_bulk_transfer_buf (us, ipipe, fst,
                FCM_STATUS_PACKET_LENGTH, &partial);

        US_DEBUGP("bar Status result %d %u\n", result, partial);
        if (result != USB_STOR_XFER_GOOD)
            return USB_STOR_TRANSPORT_ERROR;

        US_DEBUG(pdump ((void *) fst, partial));
    }

    if (partial != 4)
        return USB_STOR_TRANSPORT_ERROR;
    if ((fst->Status & 1) != 0) {
        US_DEBUGP("operation failed\n");
        return USB_STOR_TRANSPORT_FAILED;
    }

    /* The device might not have as much data available as we
     * requested.  If you ask for more than the device has, this reads
     * and such will hang. */
    US_DEBUGP("Device indicates that it has %d bytes available\n",
            le16_to_cpu (fst->Count));
    US_DEBUGP("SCSI requested %d\n", scsi_bufflen(srb));

    /* Find the length we desire to read. */
    switch (srb->cmnd[0]) {
    case INQUIRY:
    case REQUEST_SENSE: /* 16 or 18 bytes? spec says 18, lots of devices only have 16 */
    case MODE_SENSE:
    case MODE_SENSE_10:
        length = le16_to_cpu(fst->Count);
        break;
    default:
        length = scsi_bufflen(srb);
    }

    /* verify that this amount is legal */
    if (length > scsi_bufflen(srb)) {
        length = scsi_bufflen(srb);
        US_DEBUGP("Truncating request to match buffer length: %d\n", length);
    }

    /* What we do now depends on what direction the data is supposed to
     * move in. */

    switch (us->srb->sc_data_direction) {
    case DMA_FROM_DEVICE:
        /* catch bogus "read 0 length" case */
        if (!length)
            break;
        /* Make sure that the status indicates that the device
         * wants data as well. */
        if ((fst->Status & DRQ_STAT) == 0 || (fst->Reason & 3) != 2) {
            US_DEBUGP("SCSI wants data, drive doesn't have any\n");
            return USB_STOR_TRANSPORT_FAILED;
        }
        result = freecom_readdata (srb, us, ipipe, opipe, length);
        if (result != USB_STOR_TRANSPORT_GOOD)
            return result;

        US_DEBUGP("FCM: Waiting for status\n");
        result = usb_stor_bulk_transfer_buf (us, ipipe, fst,
                FCM_PACKET_LENGTH, &partial);
        US_DEBUG(pdump ((void *) fst, partial));

        if (partial != 4 || result > USB_STOR_XFER_SHORT)
            return USB_STOR_TRANSPORT_ERROR;
        if ((fst->Status & ERR_STAT) != 0) {
            US_DEBUGP("operation failed\n");
            return USB_STOR_TRANSPORT_FAILED;
        }
        if ((fst->Reason & 3) != 3) {
            US_DEBUGP("Drive seems still hungry\n");
            return USB_STOR_TRANSPORT_FAILED;
        }
        US_DEBUGP("Transfer happy\n");
        break;

    case DMA_TO_DEVICE:
        /* catch bogus "write 0 length" case */
        if (!length)
            break;
        /* Make sure the status indicates that the device wants to
         * send us data. */
        /* !!IMPLEMENT!! */
        result = freecom_writedata (srb, us, ipipe, opipe, length);
        if (result != USB_STOR_TRANSPORT_GOOD)
            return result;

        US_DEBUGP("FCM: Waiting for status\n");
        result = usb_stor_bulk_transfer_buf (us, ipipe, fst,
                FCM_PACKET_LENGTH, &partial);

        if (partial != 4 || result > USB_STOR_XFER_SHORT)
            return USB_STOR_TRANSPORT_ERROR;
        if ((fst->Status & ERR_STAT) != 0) {
            US_DEBUGP("operation failed\n");
            return USB_STOR_TRANSPORT_FAILED;
        }
        if ((fst->Reason & 3) != 3) {
            US_DEBUGP("Drive seems still hungry\n");
            return USB_STOR_TRANSPORT_FAILED;
        }

        US_DEBUGP("Transfer happy\n");
        break;


    case DMA_NONE:
        /* Easy, do nothing. */
        break;

    default:
        /* should never hit here -- filtered in usb.c */
        US_DEBUGP ("freecom unimplemented direction: %d\n",
                us->srb->sc_data_direction);
        /* Return fail, SCSI seems to handle this better. */
        return USB_STOR_TRANSPORT_FAILED;
        break;
    }

    return USB_STOR_TRANSPORT_GOOD;
}

static int init_freecom(struct us_data *us)
{
    int result;
    char *buffer = us->iobuf;

    /* The DMA-mapped I/O buffer is 64 bytes long, just right for
     * all our packets.  No need to allocate any extra buffer space.
     */

    result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
            0x4c, 0xc0, 0x4346, 0x0, buffer, 0x20, 3*HZ);
    buffer[32] = '\0';
    US_DEBUGP("String returned from FC init is: %s\n", buffer);

    /* Special thanks to the people at Freecom for providing me with
     * this "magic sequence", which they use in their Windows and MacOS
     * drivers to make sure that all the attached perhiperals are
     * properly reset.
     */

    /* send reset */
    result = usb_stor_control_msg(us, us->send_ctrl_pipe,
            0x4d, 0x40, 0x24d8, 0x0, NULL, 0x0, 3*HZ);
    US_DEBUGP("result from activate reset is %d\n", result);

    /* wait 250ms */
    mdelay(250);

    /* clear reset */
    result = usb_stor_control_msg(us, us->send_ctrl_pipe,
            0x4d, 0x40, 0x24f8, 0x0, NULL, 0x0, 3*HZ);
    US_DEBUGP("result from clear reset is %d\n", result);

    /* wait 3 seconds */
    mdelay(3 * 1000);

    return USB_STOR_TRANSPORT_GOOD;
}

static int usb_stor_freecom_reset(struct us_data *us)
{
    printk (KERN_CRIT "freecom reset called\n");

    /* We don't really have this feature. */
    return FAILED;
}

#ifdef CONFIG_USB_STORAGE_DEBUG
static void pdump (void *ibuffer, int length)
{
    static char line[80];
    int offset = 0;
    unsigned char *buffer = (unsigned char *) ibuffer;
    int i, j;
    int from, base;

    offset = 0;
    for (i = 0; i < length; i++) {
        if ((i & 15) == 0) {
            if (i > 0) {
                offset += sprintf (line+offset, " - ");
                for (j = i - 16; j < i; j++) {
                    if (buffer[j] >= 32 && buffer[j] <= 126)
                        line[offset++] = buffer[j];
                    else
                        line[offset++] = '.';
                }
                line[offset] = 0;
                US_DEBUGP("%s\n", line);
                offset = 0;
            }
            offset += sprintf (line+offset, "%08x:", i);
        } else if ((i & 7) == 0) {
            offset += sprintf (line+offset, " -");
        }
        offset += sprintf (line+offset, " %02x", buffer[i] & 0xff);
    }

    /* Add the last "chunk" of data. */
    from = (length - 1) % 16;
    base = ((length - 1) / 16) * 16;

    for (i = from + 1; i < 16; i++)
        offset += sprintf (line+offset, "   ");
    if (from < 8)
        offset += sprintf (line+offset, "  ");
    offset += sprintf (line+offset, " - ");

    for (i = 0; i <= from; i++) {
        if (buffer[base+i] >= 32 && buffer[base+i] <= 126)
            line[offset++] = buffer[base+i];
        else
            line[offset++] = '.';
    }
    line[offset] = 0;
    US_DEBUGP("%s\n", line);
    offset = 0;
}
#endif

static int freecom_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 - freecom_usb_ids) + freecom_unusual_dev_list);
    if (result)
        return result;

    us->transport_name = "Freecom";
    us->transport = freecom_transport;
    us->transport_reset = usb_stor_freecom_reset;
    us->max_lun = 0;

    result = usb_stor_probe2(us);
    return result;
}

static struct usb_driver freecom_driver = {
    .name =     "ums-freecom",
    .probe =    freecom_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 = freecom_usb_ids,
    .soft_unbind =  1,
    .no_dynamic_id = 1,
};

module_usb_driver(freecom_driver);