cedusb.tar

ced_ioc.c0000664000175000017500000016241211722662012011250 0ustar  greggreg/* ced_ioc.c
 ioctl part of the 1401 usb device driver for linux.
 Copyright (C) 2010 Cambridge Electronic Design Ltd
 Author Greg P Smith (greg@ced.co.uk)

 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
 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kref.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#include <linux/page-flags.h>
#include <linux/pagemap.h>
#include <linux/jiffies.h>

#include "usb1401.h"

/****************************************************************************
** FlushOutBuff
**
** Empties the Output buffer and sets int lines. Used from user level only
****************************************************************************/
void FlushOutBuff(DEVICE_EXTENSION *pdx)
{
    dev_dbg(&pdx->interface->dev, "%s currentState=%d", __func__, pdx->sCurrentState);
    if (pdx->sCurrentState == U14ERR_TIME)     /* Do nothing if hardware in trouble */
        return;
//    CharSend_Cancel(pdx);                   /* Kill off any pending I/O */
    spin_lock_irq(&pdx->charOutLock);
    pdx->dwNumOutput = 0;
    pdx->dwOutBuffGet = 0;
    pdx->dwOutBuffPut = 0;
    spin_unlock_irq(&pdx->charOutLock);
}

/****************************************************************************
**
** FlushInBuff
**
** Empties the input buffer and sets int lines
****************************************************************************/
void FlushInBuff(DEVICE_EXTENSION *pdx)
{
    dev_dbg(&pdx->interface->dev, "%s currentState=%d", __func__, pdx->sCurrentState);
    if (pdx->sCurrentState == U14ERR_TIME)     /* Do nothing if hardware in trouble */
        return;
//    CharRead_Cancel(pDevObject);            /* Kill off any pending I/O */
    spin_lock_irq(&pdx->charInLock);
    pdx->dwNumInput = 0;
    pdx->dwInBuffGet = 0;
    pdx->dwInBuffPut = 0;
    spin_unlock_irq(&pdx->charInLock);
}

/****************************************************************************
** PutChars
**
** Utility routine to copy chars into the output buffer and fire them off.
** called from user mode, holds charOutLock.
****************************************************************************/
static int PutChars(DEVICE_EXTENSION* pdx, const char* pCh, unsigned int uCount)
{
    int iReturn;
    spin_lock_irq(&pdx->charOutLock);   // get the output spin lock
    if ((OUTBUF_SZ - pdx->dwNumOutput) >= uCount)
    {
        unsigned int u;
        for (u=0; u<uCount; u++)
        {
            pdx->outputBuffer[pdx->dwOutBuffPut++] = pCh[u];
            if (pdx->dwOutBuffPut >= OUTBUF_SZ)
                pdx->dwOutBuffPut = 0;
        }
        pdx->dwNumOutput += uCount;
        spin_unlock_irq(&pdx->charOutLock);
        iReturn = SendChars(pdx);        // ...give a chance to transmit data
    }
    else
    {
        iReturn = U14ERR_NOOUT;          // no room at the out (ha-ha)
        spin_unlock_irq(&pdx->charOutLock);
    }
    return iReturn;
}

/*****************************************************************************
** Add the data in pData (local pointer) of length n to the output buffer, and
** trigger an output transfer if this is appropriate. User mode.
** Holds the io_mutex
*****************************************************************************/
int SendString(DEVICE_EXTENSION* pdx, const char __user* pData, unsigned int n)
{
    int iReturn = U14ERR_NOERROR;           // assume all will be well
    char buffer[OUTBUF_SZ+1];               // space in our address space for characters
    if (n > OUTBUF_SZ)                      // check space in local buffer...
        return U14ERR_NOOUT;                // ...too many characters
    if (copy_from_user(buffer, pData, n))
        return -ENOMEM;                     // could not copy
    buffer[n] = 0;                          // terminate for debug purposes

    mutex_lock(&pdx->io_mutex);             // Protect disconnect from new i/o
    if (n > 0)                              // do nothing if nowt to do!
    {
        dev_dbg(&pdx->interface->dev, "%s n=%d>%s<", __func__, n, buffer);
        iReturn = PutChars(pdx, buffer, n);
    }

    Allowi(pdx, false);                     // make sure we have input int
    mutex_unlock(&pdx->io_mutex);

   return iReturn;
}

/****************************************************************************
** SendChar
**
** Sends a single character to the 1401. User mode, holds io_mutex.
****************************************************************************/
int SendChar(DEVICE_EXTENSION *pdx, char c)
{
    int iReturn;
    mutex_lock(&pdx->io_mutex);         // Protect disconnect from new i/o
    iReturn = PutChars(pdx, &c, 1);
    dev_dbg(&pdx->interface->dev,"SendChar >%c< (0x%02x)", c, c);
    Allowi(pdx, false);                 // Make sure char reads are running
    mutex_unlock(&pdx->io_mutex);
    return iReturn;
}

/***************************************************************************
**
** Get1401State
**
**  Retrieves state information from the 1401, adjusts the 1401 state held
**  in the device extension to indicate the current 1401 type.
**
**  *state is updated with information about the 1401 state as returned by the
**         1401. The low byte is a code for what 1401 is doing:
**
**  0       normal 1401 operation
**  1       sending chars to host
**  2       sending block data to host
**  3       reading block data from host
**  4       sending an escape sequence to the host
**  0x80    1401 is executing self-test, in which case the upper word
**          is the last error code seen (or zero for no new error).
**
** *error is updated with error information if a self-test error code
**          is returned in the upper word of state.
**
**  both state and error are set to -1 if there are comms problems, and
**  to zero if there is a simple failure.
**
** return error code (U14ERR_NOERROR for OK)
*/
int Get1401State(DEVICE_EXTENSION* pdx, __u32* state, __u32* error)
{
    int nGot;
    dev_dbg(&pdx->interface->dev, "Get1401State() entry");

    *state = 0xFFFFFFFF;                        // Start off with invalid state
    nGot = usb_control_msg(pdx->udev, usb_rcvctrlpipe(pdx->udev, 0),
                           GET_STATUS, (D_TO_H|VENDOR|DEVREQ), 0,0,
                           pdx->statBuf, sizeof(pdx->statBuf), HZ);
    if (nGot != sizeof(pdx->statBuf))
    {
        dev_err(&pdx->interface->dev, "Get1401State() FAILED, return code %d", nGot);
        pdx->sCurrentState = U14ERR_TIME;  // Indicate that things are very wrong indeed
        *state = 0;                     // Force status values to a known state
        *error = 0;
    }
    else
    {
        int nDevice;
        dev_dbg(&pdx->interface->dev, "Get1401State() Success, state: 0x%x, 0x%x",
                         pdx->statBuf[0], pdx->statBuf[1]);

        *state = pdx->statBuf[0];       // Return the state values to the calling code
        *error = pdx->statBuf[1];

        nDevice = pdx->udev->descriptor.bcdDevice >> 8;    // 1401 type code value
        switch (nDevice)                // so we can clean up current state
        {
        case 0:
            pdx->sCurrentState = U14ERR_U1401;
            break;

        default:                        // allow lots of device codes for future 1401s
            if ((nDevice >= 1) && (nDevice <= 23))
                pdx->sCurrentState = (short)(nDevice + 6);
            else
                pdx->sCurrentState = U14ERR_ILL;
            break;
        }
    }

    return pdx->sCurrentState >= 0 ? U14ERR_NOERROR : pdx->sCurrentState;
}

/****************************************************************************
** ReadWrite_Cancel
**
** Kills off staged read\write request from the USB if one is pending.
****************************************************************************/
int ReadWrite_Cancel(DEVICE_EXTENSION *pdx)
{
    dev_dbg(&pdx->interface->dev, "ReadWrite_Cancel entry %d", pdx->bStagedUrbPending);
#ifdef NOT_WRITTEN_YET
    int ntStatus = STATUS_SUCCESS;
    bool bResult = false;
    unsigned int i;
    // We can fill this in when we know how we will implement the staged transfer stuff
    spin_lock_irq(&pdx->stagedLock);

    if (pdx->bStagedUrbPending)              // anything to be cancelled? May need more...
    {
        dev_info(&pdx->interface-dev, "ReadWrite_Cancel about to cancel Urb");

 //       KeClearEvent(&pdx->StagingDoneEvent);   // Clear the staging done flag
        USB_ASSERT(pdx->pStagedIrp != NULL);

        // Release the spinlock first otherwise the completion routine may hang
        //  on the spinlock while this function hands waiting for the event.
        spin_unlock_irq(&pdx->stagedLock);
        bResult = IoCancelIrp(pdx->pStagedIrp); // Actually do the cancel
        if (bResult)
        {
            LARGE_INTEGER timeout;
            timeout.QuadPart = -10000000;       // Use a timeout of 1 second
            dev_info(&pdx->interface-dev, "ReadWrite_Cancel about to wait till done");
            ntStatus = KeWaitForSingleObject(&pdx->StagingDoneEvent, Executive,
                                             KernelMode, FALSE, &timeout);
        }
        else
        {
            dev_info(&pdx->interface-dev, "ReadWrite_Cancel, cancellation failed");
            ntStatus = U14ERR_FAIL;
        }
        USB_KdPrint(DBGLVL_DEFAULT, ("ReadWrite_Cancel ntStatus = 0x%x decimal %d\n", ntStatus, ntStatus));
    }
    else
        spin_unlock_irq(&pdx->stagedLock);

    dev_info(&pdx->interface-dev, "ReadWrite_Cancel  done");
    return ntStatus;
#else
    return U14ERR_NOERROR;
#endif

}

/***************************************************************************
** InSelfTest - utility to check in self test. Return 1 for ST, 0 for not or
** a -ve error code if we failed for some reason.
***************************************************************************/
static int InSelfTest(DEVICE_EXTENSION* pdx, unsigned int* pState)
{
    unsigned int state, error;
    int iReturn = Get1401State(pdx, &state, &error);    // see if in self-test
    if (iReturn == U14ERR_NOERROR)                  // if all still OK
         iReturn = (state == (unsigned int)-1) ||   // TX problem or...
                   ((state & 0xff) == 0x80);        // ...self test
    *pState = state;                                // return actual state
    return iReturn;
}

/***************************************************************************
** Is1401 - ALWAYS CALLED HOLDING THE io_mutex
**
** Tests for the current state of the 1401. Sets sCurrentState:
**
**  U14ERR_NOIF  1401  i/f card not installed (not done here)
**  U14ERR_OFF   1401  apparently not switched on
**  U14ERR_NC    1401  appears to be not connected
**  U14ERR_ILL   1401  if it is there its not very well at all
**  U14ERR_TIME  1401  appears OK, but doesn't communicate - very bad
**  U14ERR_STD   1401  OK and ready for use
**  U14ERR_PLUS  1401+ OK and ready for use
**  U14ERR_U1401 Micro1401 OK and ready for use
**  U14ERR_POWER Power1401 OK and ready for use
**  U14ERR_U14012 Micro1401 mkII OK and ready for use
**
**  Returns TRUE if a 1401 detected and OK, else FALSE
****************************************************************************/
bool Is1401(DEVICE_EXTENSION* pdx)
{
    int iReturn;
    dev_dbg(&pdx->interface->dev, "%s", __func__);

    ced_draw_down(pdx);                     // wait for, then kill outstanding Urbs
    FlushInBuff(pdx);                       // Clear out input buffer & pipe
    FlushOutBuff(pdx);                      // Clear output buffer & pipe

    // The next call returns 0 if OK, but has returned 1 in the past, meaning that
    // usb_unlock_device() is needed... now it always is
    iReturn = usb_lock_device_for_reset(pdx->udev, pdx->interface);

    // release the io_mutex because if we don't, we will deadlock due to system
    // calls back into the driver.
    mutex_unlock(&pdx->io_mutex);           // locked, so we will not get system calls
    if (iReturn >= 0)                       // if we failed
    {
        iReturn = usb_reset_device(pdx->udev);  // try to do the reset
        usb_unlock_device(pdx->udev);       // undo the lock
    }

    mutex_lock(&pdx->io_mutex);             // hold stuff off while we wait
    pdx->dwDMAFlag = MODE_CHAR;             // Clear DMA mode flag regardless!
    if (iReturn == 0)                       // if all is OK still
    {
        unsigned int state;
        iReturn = InSelfTest(pdx, &state);  // see if likely in self test
        if (iReturn > 0)                    // do we need to wait for self-test?
        {
            unsigned long ulTimeOut = jiffies + 30*HZ;  // when to give up
            while((iReturn > 0) && time_before(jiffies, ulTimeOut))
            {
                schedule();                 // let other stuff run
                iReturn = InSelfTest(pdx, &state);  // see if done yet
            }
        }

        if (iReturn == 0)                   // if all is OK...
            iReturn = state == 0;           // then sucess is that the state is 0
    }
    else
        iReturn = 0;                        // we failed
    pdx->bForceReset = false;               // Clear forced reset flag now

    return iReturn > 0;
}

/****************************************************************************
** QuickCheck  - ALWAYS CALLED HOLDING THE io_mutex
** This is used to test for a 1401. It will try to do a quick check if all is
**  OK, that is the 1401 was OK the last time it was asked, and there is no DMA
**  in progress, and if the bTestBuff flag is set, the character buffers must be
**  empty too. If the quick check shows that the state is still the same, then
**  all is OK.
**
** If any of the above conditions are not met, or if the state or type of the
**  1401 has changed since the previous test, the full Is1401 test is done, but
**  only if bCanReset is also TRUE.
**
** The return value is TRUE if a useable 1401 is found, FALSE if not
*/
bool QuickCheck(DEVICE_EXTENSION* pdx, bool bTestBuff, bool bCanReset)
{
    bool bRet = false;           // assume it will fail and we will reset
    bool bShortTest;

    bShortTest = ((pdx->dwDMAFlag == MODE_CHAR) &&  // no DMA running
                  (!pdx->bForceReset) &&            // Not had a real reset forced
                  (pdx->sCurrentState >= U14ERR_STD));  // No 1401 errors stored

    dev_dbg(&pdx->interface->dev, "%s DMAFlag:%d, state:%d, force:%d, testBuff:%d, short:%d",
                     __func__, pdx->dwDMAFlag, pdx->sCurrentState, pdx->bForceReset, bTestBuff, bShortTest);

    if ((bTestBuff) &&                              // Buffer check requested, and...
        (pdx->dwNumInput || pdx->dwNumOutput))      // ...characters were in the buffer?
    {
        bShortTest = false;                         // Then do the full test
        dev_dbg(&pdx->interface->dev, "%s will reset as buffers not empty", __func__);
    }

    if (bShortTest || !bCanReset)                   // Still OK to try the short test?
    {                                               // Always test if no reset - we want state update
        unsigned int state, error;
        dev_dbg(&pdx->interface->dev, "%s->Get1401State", __func__);
        if (Get1401State(pdx, &state, &error) == U14ERR_NOERROR) // Check on the 1401 state
        {
            if ((state & 0xFF) == 0)                // If call worked, check the status value
                bRet = true;                        // If that was zero, all is OK, no reset needed
        }
    }

    if (!bRet && bCanReset)                         // If all not OK, then
    {
        dev_info(&pdx->interface->dev, "%s->Is1401 %d %d %d %d",
                 __func__, bShortTest, pdx->sCurrentState, bTestBuff, pdx->bForceReset);
        bRet = Is1401(pdx);                         //  do full test
    }

    return bRet;
}

/****************************************************************************
** Reset1401
**
** Resets the 1401 and empties the i/o buffers
*****************************************************************************/
int Reset1401(DEVICE_EXTENSION *pdx)
{
    mutex_lock(&pdx->io_mutex);             // Protect disconnect from new i/o
    dev_dbg(&pdx->interface->dev,"ABout to call QuickCheck");
    QuickCheck(pdx, true, true);            // Check 1401, reset if not OK
    mutex_unlock(&pdx->io_mutex);
    return U14ERR_NOERROR;
}

/****************************************************************************
** GetChar
**
** Gets a single character from the 1401
****************************************************************************/
int GetChar(DEVICE_EXTENSION *pdx)
{
    int iReturn = U14ERR_NOIN;             // assume we will get  nothing
    mutex_lock(&pdx->io_mutex);         // Protect disconnect from new i/o

    dev_dbg(&pdx->interface->dev, "GetChar");

    Allowi(pdx, false);                 // Make sure char reads are running
    SendChars(pdx);                     // and send any buffered chars

    spin_lock_irq(&pdx->charInLock);
    if (pdx->dwNumInput > 0)            // worth looking
    {
        iReturn = pdx->inputBuffer[pdx->dwInBuffGet++];
        if (pdx->dwInBuffGet >= INBUF_SZ)
            pdx->dwInBuffGet = 0;
        pdx->dwNumInput--;
    }
    else
        iReturn = U14ERR_NOIN;             // no input data to read
    spin_unlock_irq(&pdx->charInLock);

    Allowi(pdx, false);                 // Make sure char reads are running

    mutex_unlock(&pdx->io_mutex);       // Protect disconnect from new i/o
    return iReturn;
}

/****************************************************************************
** GetString
**
** Gets a string from the 1401. Returns chars up to the next CR or when
** there are no more to read or nowhere to put them. CR is translated to
** 0 and counted as a character. If the string does not end in a 0, we will
** add one, if there is room, but it is not counted as a character.
**
** returns the count of characters (including the terminator, or 0 if none
** or a negative error code.
****************************************************************************/
int GetString(DEVICE_EXTENSION *pdx, char __user* pUser, int n)
{
    int nAvailable;                         // character in the buffer
    int iReturn = U14ERR_NOIN;
    if (n <= 0)
        return -ENOMEM;

    mutex_lock(&pdx->io_mutex);             // Protect disconnect from new i/o
    Allowi(pdx, false);                     // Make sure char reads are running
    SendChars(pdx);                         // and send any buffered chars

    spin_lock_irq(&pdx->charInLock);
    nAvailable = pdx->dwNumInput;           // characters available now
    if (nAvailable > n)                     // read max of space in pUser...
        nAvailable = n;                     // ...or input characters

    if (nAvailable > 0)                     // worth looking?
    {
        char buffer[INBUF_SZ+1];            // space for a linear copy of data
        int nGot = 0;
        int nCopyToUser;                    // number to copy to user
        char cData;
        do
        {
            cData = pdx->inputBuffer[pdx->dwInBuffGet++];
            if (cData == CR_CHAR)           // replace CR with zero
                cData = (char)0;

            if (pdx->dwInBuffGet >= INBUF_SZ)
                pdx->dwInBuffGet = 0;       // wrap buffer pointer

            buffer[nGot++] = cData;         // save the output
        }
        while((nGot < nAvailable) && cData);

        nCopyToUser = nGot;                 // what to copy...
        if (cData)                          // do we need null
        {
            buffer[nGot] = (char)0;         // make it tidy
            if (nGot < n)                   // if space in user buffer...
                ++nCopyToUser;              // ...copy the 0 as well.
        }

        pdx->dwNumInput -= nGot;
        spin_unlock_irq(&pdx->charInLock);

        dev_dbg(&pdx->interface->dev,"GetString read %d characters >%s<", nGot, buffer);
        copy_to_user(pUser, buffer, nCopyToUser);

        iReturn = nGot;                     // report characters read
    }
    else
        spin_unlock_irq(&pdx->charInLock);

    Allowi(pdx, false);                     // Make sure char reads are running
    mutex_unlock(&pdx->io_mutex);           // Protect disconnect from new i/o

    return iReturn;
}

/*******************************************************************************
** Get count of characters in the inout buffer.
*******************************************************************************/
int Stat1401(DEVICE_EXTENSION *pdx)
{
    int iReturn;
    mutex_lock(&pdx->io_mutex);             // Protect disconnect from new i/o
    Allowi(pdx, false);                     // make sure we allow pending chars
    SendChars(pdx);                         // in both directions
    iReturn = pdx->dwNumInput;              // no lock as single read
    mutex_unlock(&pdx->io_mutex);           // Protect disconnect from new i/o
    return iReturn;
}

/****************************************************************************
** LineCount
**
** Returns the number of newline chars in the buffer. There is no need for
** any fancy interlocks as we only read the interrupt routine data, and the
** system is arranged so nothing can be destroyed.
****************************************************************************/
int LineCount(DEVICE_EXTENSION *pdx)
{
    int iReturn = 0;                        // will be count of line ends

    mutex_lock(&pdx->io_mutex);             // Protect disconnect from new i/o
    Allowi(pdx, false);                     // Make sure char reads are running
    SendChars(pdx);                         // and send any buffered chars
    spin_lock_irq(&pdx->charInLock);        // Get protection

    if (pdx->dwNumInput > 0)                    // worth looking?
    {
        unsigned int dwIndex = pdx->dwInBuffGet;// start at first available
        unsigned int dwEnd = pdx->dwInBuffPut;  // Position for search end
        do
        {
            if (pdx->inputBuffer[dwIndex++] == CR_CHAR)
                ++iReturn;                      // inc count if CR

            if (dwIndex >= INBUF_SZ)            // see if we fall off buff
                dwIndex = 0;
        }
        while (dwIndex != dwEnd);               // go to last avaliable
    }

    spin_unlock_irq(&pdx->charInLock);
    dev_dbg(&pdx->interface->dev,"LineCount returned %d", iReturn);
    mutex_unlock(&pdx->io_mutex);             // Protect disconnect from new i/o
    return iReturn;
}

/****************************************************************************
** GetOutBufSpace
**
** Gets the space in the output buffer. Called from user code.
*****************************************************************************/
int GetOutBufSpace(DEVICE_EXTENSION *pdx)
{
    int iReturn;
    mutex_lock(&pdx->io_mutex);             // Protect disconnect from new i/o
    SendChars(pdx);                                 // send any buffered chars
    iReturn = (int)(OUTBUF_SZ - pdx->dwNumOutput);  // no lock needed for single read
    dev_dbg(&pdx->interface->dev,"OutBufSpace %d", iReturn);
    mutex_unlock(&pdx->io_mutex);           // Protect disconnect from new i/o
    return iReturn;
}

/****************************************************************************
**
** ClearArea
**
** Clears up a transfer area. This is always called in the context of a user
** request, never from a call-back.
****************************************************************************/
int ClearArea(DEVICE_EXTENSION *pdx, int nArea)
{
    int iReturn = U14ERR_NOERROR;

    if ((nArea < 0) || (nArea >= MAX_TRANSAREAS))
    {
        iReturn = U14ERR_BADAREA;
        dev_err(&pdx->interface->dev, "%s Attempt to clear area %d", __func__, nArea);
    }
    else
    {
        TRANSAREA *pTA = &pdx->rTransDef[nArea]; // to save typing
        if (!pTA->bUsed)                            // if not used...
            iReturn = U14ERR_NOTSET;                // ...nothing to be done
        else
        {
            // We must save the memory we return as we shouldn't mess with memory while
            // holding a spin lock.
            struct page **pPages = 0;               // save page address list
            int nPages = 0;                         // and number of pages
            int np;

            dev_dbg(&pdx->interface->dev, "%s area %d", __func__, nArea);
            spin_lock_irq(&pdx->stagedLock);
            if ((pdx->StagedId == nArea) && (pdx->dwDMAFlag > MODE_CHAR))
            {
                iReturn = U14ERR_UNLOCKFAIL;               // cannot delete as in use
                dev_err(&pdx->interface->dev, "%s call on area %d while active", __func__, nArea);
            }
            else
            {
                pPages = pTA->pPages;               // save page address list
                nPages = pTA->nPages;               // and page count
                if (pTA->dwEventSz)                 // if events flagging in use
                    wake_up_interruptible(&pTA->wqEvent);   // release anything that was waiting

                 if (pdx->bXFerWaiting && (pdx->rDMAInfo.wIdent == nArea))
                    pdx->bXFerWaiting = false;           // Cannot have pending xfer if area cleared

                // Clean out the TRANSAREA except for the wait queue, which is at the end
                // This sets bUsed to false and dwEventSz to 0 to say area not used and no events.
                memset(pTA, 0, sizeof(TRANSAREA)-sizeof(wait_queue_head_t));
            }
            spin_unlock_irq(&pdx->stagedLock);

            if (pPages)                             // if we decided to release the memory
            {
                // Now we must undo the pinning down of the pages. We will assume the worst and mark
                // all the pages as dirty. Don't be tempted to move this up above as you must not be
                // holding a spin lock to do this stuff as it is not atomic.
                dev_dbg(&pdx->interface->dev, "%s nPages=%d", __func__, nPages);

                for (np = 0; np < nPages; ++np)
                {
                    if (pPages[np])
                    {
                        SetPageDirty(pPages[np]);
                        page_cache_release(pPages[np]);
                    }
                }

                kfree(pPages);
                dev_dbg(&pdx->interface->dev, "%s kfree(pPages) done", __func__);
            }
        }
    }

    return iReturn;
}

/****************************************************************************
** SetArea
**
** Sets up a transfer area - the functional part. Called by both
** SetTransfer and SetCircular.
****************************************************************************/
static int SetArea(DEVICE_EXTENSION *pdx, int nArea, char __user* puBuf,
                     unsigned int dwLength, bool bCircular, bool bCircToHost)
{
    // Start by working out the page aligned start of the area and the size
    // of the area in pages, allowing for the start not being aligned and the
    // end needing to be rounded up to a page boundary.
    unsigned long ulStart = ((unsigned long)puBuf) & PAGE_MASK;
    unsigned int ulOffset = ((unsigned long)puBuf) & (PAGE_SIZE-1);
    int len = (dwLength + ulOffset+PAGE_SIZE - 1) >> PAGE_SHIFT;

    TRANSAREA *pTA = &pdx->rTransDef[nArea]; // to save typing
    struct page **pPages = 0;               // space for page tables
    int nPages = 0;                         // and number of pages

    int iReturn = ClearArea(pdx, nArea);    // see if OK to use this area
    if ((iReturn != U14ERR_NOTSET) &&          // if not area unused and...
        (iReturn != U14ERR_NOERROR))           // ...not all OK, then...
        return iReturn;                     // ...we cannot use this area

    if (!access_ok(VERIFY_WRITE, puBuf, dwLength))  // if we cannot access the memory...
        return -EFAULT;                     // ...then we are done

    // Now allocate space to hold the page pointer and virtual address pointer tables
    pPages = (struct page **)kmalloc(len*sizeof(struct page *), GFP_KERNEL);
    if (!pPages)
    {
        iReturn = U14ERR_NOMEMORY;
        goto error;
    }
    dev_dbg(&pdx->interface->dev, "%s %p, length=%06x, circular %d", __func__, puBuf, dwLength, bCircular);

    // To pin down user pages we must first acquire the mapping semaphore.
    down_read(&current->mm->mmap_sem);   // get memory map semaphore
    nPages = get_user_pages(current, current->mm, ulStart, len, 1, 0, pPages, 0);
    up_read(&current->mm->mmap_sem);     // release the semaphore
    dev_dbg(&pdx->interface->dev, "%s nPages = %d", __func__, nPages);

    if (nPages > 0)                     // if we succeeded
    {
        // If you are tempted to use page_address (form LDD3), forget it. You MUST use
        // kmap() or kmap_atomic() to get a virtual address. page_address will give you
        // (null) or at least it does in this context with an x86 machine.
        spin_lock_irq(&pdx->stagedLock);
        pTA->lpvBuff = puBuf;           // keep start of region (user address)
        pTA->dwBaseOffset = ulOffset;   // save offset in first page to start of xfer
        pTA->dwLength = dwLength;       // Size if the region in bytes
        pTA->pPages = pPages;           // list of pages that are used by buffer
        pTA->nPages = nPages;           // number of pages

        pTA->bCircular = bCircular;
        pTA->bCircToHost = bCircToHost;

        pTA->aBlocks[0].dwOffset = 0;
        pTA->aBlocks[0].dwSize = 0;
        pTA->aBlocks[1].dwOffset = 0;
        pTA->aBlocks[1].dwSize = 0;
        pTA->bUsed = true;              // This is now a used block

        spin_unlock_irq(&pdx->stagedLock);
        iReturn = U14ERR_NOERROR;          // say all was well
    }
    else
    {
        iReturn = U14ERR_LOCKFAIL;
        goto error;
    }

    return iReturn;

error:
    kfree(pPages);
    return iReturn;
}

/****************************************************************************
** SetTransfer
**
** Sets up a transfer area record. If the area is already set, we attempt to
** unset it. Unsetting will fail if the area is booked, and a transfer to that
** area is in progress. Otherwise, we will release the area and re-assign it.
****************************************************************************/
int SetTransfer(DEVICE_EXTENSION *pdx, TRANSFERDESC __user *pTD)
{
    int iReturn;
    TRANSFERDESC td;
    copy_from_user(&td, pTD, sizeof(td));
    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev,"%s area:%d, size:%08x", __func__, td.wAreaNum, td.dwLength);
    // The strange cast is done so that we don't get warnings in 32-bit linux about the size of the
    // pointer. The pointer is always passed as a 64-bit object so that we don't have problems using
    // a 32-bit program on a 64-bit system. unsigned long is 64-bits on a 64-bit system.
    iReturn = SetArea(pdx, td.wAreaNum, (char __user *)((unsigned long)td.lpvBuff), td.dwLength, false, false);
    mutex_unlock(&pdx->io_mutex);
    return iReturn;
}

/****************************************************************************
** UnSetTransfer
** Erases a transfer area record
****************************************************************************/
int UnsetTransfer(DEVICE_EXTENSION *pdx, int nArea)
{
    int iReturn;
    mutex_lock(&pdx->io_mutex);
    iReturn = ClearArea(pdx, nArea);
    mutex_unlock(&pdx->io_mutex);
    return iReturn;
}

/****************************************************************************
** SetEvent
** Creates an event that we can test for based on a transfer to/from an area.
** The area must be setup for a transfer. We attempt to simulate the Windows
** driver behavior for events (as we don't actually use them), which is to
** pretend that whatever the user asked for was achieved, so we return 1 if
** try to create one, and 0 if they ask to remove (assuming all else was OK).
****************************************************************************/
int SetEvent(DEVICE_EXTENSION *pdx, TRANSFEREVENT __user*pTE)
{
    int iReturn = U14ERR_NOERROR;
    TRANSFEREVENT te;
    copy_from_user(&te, pTE, sizeof(te));   // get a local copy of the data
    if (te.wAreaNum >= MAX_TRANSAREAS)      // the area must exist
        return U14ERR_BADAREA;
    else
    {
        TRANSAREA *pTA = &pdx->rTransDef[te.wAreaNum];
        mutex_lock(&pdx->io_mutex);         // make sure we have no competitor
        spin_lock_irq(&pdx->stagedLock);
        if (pTA->bUsed)                     // area must be in use
        {
            pTA->dwEventSt = te.dwStart;    // set area regions
            pTA->dwEventSz = te.dwLength;   // set size (0 cancels it)
            pTA->bEventToHost = te.wFlags & 1; // set the direction
            pTA->iWakeUp = 0;               // zero the wake up count
        }
        else
            iReturn = U14ERR_NOTSET;
        spin_unlock_irq(&pdx->stagedLock);
        mutex_unlock(&pdx->io_mutex);
    }
    return iReturn == U14ERR_NOERROR ? (te.iSetEvent ? 1 : U14ERR_NOERROR) : iReturn;
}

/****************************************************************************
** WaitEvent
** Sleep the process with a timeout waiting for an event. Returns the number
** of times that a block met the event condition since we last cleared it or
** 0 if timed out, or -ve error (bad area or not set, or signal).
****************************************************************************/
int WaitEvent(DEVICE_EXTENSION *pdx, int nArea, int msTimeOut)
{
    int iReturn;
    if ((unsigned)nArea > MAX_TRANSAREAS)
        return U14ERR_BADAREA;
    else
    {
        int iWait;
        TRANSAREA *pTA = &pdx->rTransDef[nArea];
        msTimeOut = (msTimeOut * HZ + 999)/1000; // convert timeout to jiffies

        // We cannot wait holding the mutex, but we check the flags while holding
        // it. This may well be pointless as another thread could get in between
        // releasing it and the wait call. However, this would have to clear the
        // iWakeUp flag. However, the !pTA-bUsed may help us in this case.
        mutex_lock(&pdx->io_mutex);         // make sure we have no competitor
        if (!pTA->bUsed || !pTA->dwEventSz) // check something to wait for...
            return U14ERR_NOTSET;           // ...else we do nothing
        mutex_unlock(&pdx->io_mutex);

        if (msTimeOut)
            iWait = wait_event_interruptible_timeout(pTA->wqEvent, pTA->iWakeUp || !pTA->bUsed, msTimeOut);
        else
            iWait = wait_event_interruptible(pTA->wqEvent, pTA->iWakeUp || !pTA->bUsed);
        if (iWait)
            iReturn = -ERESTARTSYS;         // oops - we have had a SIGNAL
        else
            iReturn = pTA->iWakeUp;         // else the wakeup count

        spin_lock_irq(&pdx->stagedLock);
        pTA->iWakeUp = 0;                   // clear the flag
        spin_unlock_irq(&pdx->stagedLock);
    }
    return iReturn;
}

/****************************************************************************
** TestEvent
** Test the event to see if a WaitEvent would return immediately. Returns the
** number of times a block completed since the last call, or 0 if none or a
** negative error.
****************************************************************************/
int TestEvent(DEVICE_EXTENSION *pdx, int nArea)
{
    int iReturn;
    if ((unsigned)nArea > MAX_TRANSAREAS)
        iReturn = U14ERR_BADAREA;
    else
    {
        TRANSAREA *pTA = &pdx->rTransDef[nArea];
        mutex_lock(&pdx->io_mutex);         // make sure we have no competitor
        spin_lock_irq(&pdx->stagedLock);
        iReturn = pTA->iWakeUp;             // get wakeup count since last call
        pTA->iWakeUp = 0;                   // clear the count
        spin_unlock_irq(&pdx->stagedLock);
        mutex_unlock(&pdx->io_mutex);
    }
    return iReturn;
}

/****************************************************************************
** GetTransferInfo
** Puts the current state of the 1401 in a TGET_TX_BLOCK.
*****************************************************************************/
int GetTransfer(DEVICE_EXTENSION *pdx, TGET_TX_BLOCK __user *pTX)
{
    int iReturn = U14ERR_NOERROR;
    unsigned int dwIdent;

    mutex_lock(&pdx->io_mutex);
    dwIdent = pdx->StagedId;                // area ident for last xfer
    if (dwIdent >= MAX_TRANSAREAS)
        iReturn = U14ERR_BADAREA;
    else
    {
        // Return the best information we have - we don't have physical addresses
        TGET_TX_BLOCK tx;
        memset(&tx, 0, sizeof(tx));         // clean out local work structure
        tx.size = pdx->rTransDef[dwIdent].dwLength;
        tx.linear = (long long)((long)pdx->rTransDef[dwIdent].lpvBuff);
        tx.avail = GET_TX_MAXENTRIES;       // how many blocks we could return
        tx.used = 1;                        // number we actually return
        tx.entries[0].physical = (long long)(tx.linear+pdx->StagedOffset);
        tx.entries[0].size = tx.size;
        copy_to_user(pTX, &tx, sizeof(tx));
    }
    mutex_unlock(&pdx->io_mutex);
    return iReturn;
}

/****************************************************************************
** KillIO1401
**
** Empties the host i/o buffers
****************************************************************************/
int KillIO1401(DEVICE_EXTENSION *pdx)
{
    dev_dbg(&pdx->interface->dev, "%s", __func__);
    mutex_lock(&pdx->io_mutex);
    FlushOutBuff(pdx);
    FlushInBuff(pdx);
    mutex_unlock(&pdx->io_mutex);
    return U14ERR_NOERROR;
}

/****************************************************************************
** BlkTransState
** Returns a 0 or a 1 for whether DMA is happening. No point holding a mutex
** for this as it only does one read.
*****************************************************************************/
int BlkTransState(DEVICE_EXTENSION *pdx)
{
    int iReturn = pdx->dwDMAFlag != MODE_CHAR;
    dev_dbg(&pdx->interface->dev, "%s = %d", __func__, iReturn);
    return iReturn;
}

/****************************************************************************
** StateOf1401
**
** Puts the current state of the 1401 in the Irp return buffer.
*****************************************************************************/
int StateOf1401(DEVICE_EXTENSION *pdx)
{
    int iReturn;
    mutex_lock(&pdx->io_mutex);

    QuickCheck(pdx, false, false);    // get state up to date, no reset
    iReturn = pdx->sCurrentState;

    mutex_unlock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s = %d", __func__, iReturn);

    return iReturn;
}
/****************************************************************************
** StartSelfTest
**
** Initiates a self-test cycle. The assumption is that we have no interrupts
** active, so we should make sure that this is the case.
*****************************************************************************/
int StartSelfTest(DEVICE_EXTENSION *pdx)
{
    int nGot;
    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s", __func__);

    ced_draw_down(pdx);                     // wait for, then kill outstanding Urbs
    FlushInBuff(pdx);                       // Clear out input buffer & pipe
    FlushOutBuff(pdx);                      // Clear output buffer & pipe
//    ReadWrite_Cancel(pDeviceObject);        /* so things stay tidy */
    pdx->dwDMAFlag = MODE_CHAR;             /* Clear DMA mode flags here */

    nGot = usb_control_msg(pdx->udev, usb_rcvctrlpipe(pdx->udev, 0),
                       DB_SELFTEST, (H_TO_D|VENDOR|DEVREQ), 0, 0,
                       0, 0, HZ);           // allow 1 second timeout
    pdx->ulSelfTestTime = jiffies + HZ*30;  // 30 seconds into the future

    mutex_unlock(&pdx->io_mutex);
    if (nGot < 0)
        dev_err(&pdx->interface->dev, "%s err=%d", __func__, nGot);
    return nGot < 0 ? U14ERR_FAIL : U14ERR_NOERROR;
}


/****************************************************************************
** CheckSelfTest
**
** Check progress of a self-test cycle
****************************************************************************/
int CheckSelfTest(DEVICE_EXTENSION *pdx, TGET_SELFTEST __user *pGST)
{
    unsigned int state, error;
    int iReturn;
    TGET_SELFTEST gst;                      // local work space
    memset(&gst, 0, sizeof(gst));           // clear out the space (sets code 0)

    mutex_lock(&pdx->io_mutex);

    dev_dbg(&pdx->interface->dev, "%s", __func__);
    iReturn = Get1401State(pdx, &state, &error);
    if (iReturn == U14ERR_NOERROR)             // Only accept zero if it happens twice
        iReturn = Get1401State(pdx, &state, &error);

    if (iReturn != U14ERR_NOERROR)             // Self-test can cause comms errors
    {                                       // so we assume still testing
        dev_err(&pdx->interface->dev, "%s Get1401State=%d, assuming still testing", __func__, iReturn);
        state = 0x80;                       // Force still-testing, no error
        error = 0;
        iReturn = U14ERR_NOERROR;
    }

    if ((state == -1) && (error == -1))     // If Get1401State had problems
    {
        dev_err(&pdx->interface->dev, "%s Get1401State failed, assuming still testing", __func__);
        state = 0x80;                       // Force still-testing, no error
        error = 0;
    }

    if ((state & 0xFF) == 0x80)             // If we are still in self-test
    {
        if (state & 0x00FF0000)             // Have we got an error?
        {
            gst.code = (state & 0x00FF0000) >> 16;  // read the error code
            gst.x = error & 0x0000FFFF;             // Error data X
            gst.y = (error & 0xFFFF0000) >> 16;     // and data Y
            dev_dbg(&pdx->interface->dev,"Self-test error code %d", gst.code);
        }
        else                                // No error, check for timeout
        {
            unsigned long ulNow = jiffies;  // get current time
            if (time_after(ulNow, pdx->ulSelfTestTime))
            {
                gst.code = -2;              // Flag the timeout
                dev_dbg(&pdx->interface->dev, "Self-test timed-out");
            }
            else
                dev_dbg(&pdx->interface->dev, "Self-test on-going");
        }
    }
    else
    {
        gst.code = -1;                      // Flag the test is done
        dev_dbg(&pdx->interface->dev, "Self-test done");
    }

    if (gst.code < 0)                       // If we have a problem or finished
    {                                       // If using the 2890 we should reset properly
        if ((pdx->nPipes == 4) && (pdx->s1401Type <= TYPEPOWER))
            Is1401(pdx);                    // Get 1401 reset and OK
        else
            QuickCheck(pdx, true, true);    // Otherwise check without reset unless problems
    }
    mutex_unlock(&pdx->io_mutex);

    copy_to_user(pGST, &gst, sizeof(gst));  // copy result to user space
    return iReturn;
}

/****************************************************************************
** TypeOf1401
**
** Returns code for standard, plus, micro1401, power1401 or none
****************************************************************************/
int TypeOf1401(DEVICE_EXTENSION *pdx)
{
    int iReturn = TYPEUNKNOWN;
    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s", __func__);

    switch (pdx->s1401Type)
    {
    case TYPE1401: iReturn = U14ERR_STD;  break;   // Handle these types directly
    case TYPEPLUS: iReturn = U14ERR_PLUS; break;
    case TYPEU1401:iReturn = U14ERR_U1401;break;
    default:
        if ((pdx->s1401Type >= TYPEPOWER) &&
            (pdx->s1401Type <= 25))
            iReturn = pdx->s1401Type + 4;       // We can calculate types
        else                                    //  for up-coming 1401 designs
            iReturn = TYPEUNKNOWN;              // Don't know or not there
    }
    dev_dbg(&pdx->interface->dev, "%s %d", __func__, iReturn);
    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}

/****************************************************************************
** TransferFlags
**
** Returns flags on block transfer abilities
****************************************************************************/
int TransferFlags(DEVICE_EXTENSION *pdx)
{
    int iReturn = U14TF_MULTIA | U14TF_DIAG |   // we always have multiple DMA area
                  U14TF_NOTIFY | U14TF_CIRCTH;  // diagnostics, notify and circular
    dev_dbg(&pdx->interface->dev, "%s", __func__);
    mutex_lock(&pdx->io_mutex);
    if (pdx->bIsUSB2)                           // Set flag for USB2 if appropriate
        iReturn |= U14TF_USB2;
    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}

/***************************************************************************
** DbgCmd1401
** Issues a debug\diagnostic command to the 1401 along with a 32-bit datum
** This is a utility command used for dbg operations.
*/
static int DbgCmd1401(DEVICE_EXTENSION *pdx, unsigned char cmd, unsigned int data)
{
    int iReturn;
    dev_dbg(&pdx->interface->dev, "%s entry", __func__);
    iReturn = usb_control_msg(pdx->udev, usb_sndctrlpipe(pdx->udev, 0),
                       cmd, (H_TO_D|VENDOR|DEVREQ),
                       (unsigned short)data, (unsigned short)(data >> 16),
                       0, 0, HZ);           // allow 1 second timeout
    if (iReturn < 0)
        dev_err(&pdx->interface->dev, "%s fail code=%d", __func__, iReturn);

    return iReturn;
}

/****************************************************************************
** DbgPeek
**
** Execute the diagnostic peek operation. Uses address, width and repeats.
****************************************************************************/
int DbgPeek(DEVICE_EXTENSION *pdx, TDBGBLOCK __user* pDB)
{
    int iReturn;
    TDBGBLOCK db;
    copy_from_user(&db, pDB, sizeof(db));   // get the data

    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s @ %08x", __func__, db.iAddr);

    iReturn = DbgCmd1401(pdx, DB_SETADD, db.iAddr);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_WIDTH, db.iWidth);
    if (iReturn == U14ERR_NOERROR)
       iReturn = DbgCmd1401(pdx, DB_REPEATS, db.iRepeats);
    if (iReturn == U14ERR_NOERROR)
       iReturn = DbgCmd1401(pdx, DB_PEEK, 0);
    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}


/****************************************************************************
** DbgPoke
**
** Execute the diagnostic poke operation. Parameters are in the CSBLOCK struct
** in order address, size, repeats and value to poke.
****************************************************************************/
int DbgPoke(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB)
{
    int iReturn;
    TDBGBLOCK db;
    copy_from_user(&db, pDB, sizeof(db));   // get the data

    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s @ %08x", __func__, db.iAddr);

    iReturn = DbgCmd1401(pdx, DB_SETADD, db.iAddr);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_WIDTH, db.iWidth);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_REPEATS, db.iRepeats);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_POKE, db.iData);
    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}


/****************************************************************************
** DbgRampData
**
** Execute the diagnostic ramp data operation. Parameters are in the CSBLOCK struct
** in order address, default, enable mask, size and repeats.
****************************************************************************/
int DbgRampData(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB)
{
    int iReturn;
    TDBGBLOCK db;
    copy_from_user(&db, pDB, sizeof(db));   // get the data

    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s @ %08x", __func__, db.iAddr);

    iReturn = DbgCmd1401(pdx, DB_SETADD, db.iAddr);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_SETDEF, db.iDefault);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_SETMASK, db.iMask);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_WIDTH, db.iWidth);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_REPEATS, db.iRepeats);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_RAMPD, 0);
    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}


/****************************************************************************
** DbgRampAddr
**
** Execute the diagnostic ramp address operation
****************************************************************************/
int DbgRampAddr(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB)
{
    int iReturn;
    TDBGBLOCK db;
    copy_from_user(&db, pDB, sizeof(db));   // get the data

    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s", __func__);

    iReturn = DbgCmd1401(pdx, DB_SETDEF, db.iDefault);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_SETMASK, db.iMask);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_WIDTH, db.iWidth);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_REPEATS, db.iRepeats);
    if (iReturn == U14ERR_NOERROR)
        iReturn = DbgCmd1401(pdx, DB_RAMPA, 0);
    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}


/****************************************************************************
** DbgGetData
**
** Retrieve the data resulting from the last debug Peek operation
****************************************************************************/
int DbgGetData(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB)
{
    int iReturn;
    TDBGBLOCK db;
    memset(&db, 0, sizeof(db));     // fill returned block with 0s

    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s", __func__);

    // Read back the last peeked value from the 1401.
    iReturn = usb_control_msg(pdx->udev, usb_rcvctrlpipe(pdx->udev, 0),
                           DB_DATA, (D_TO_H|VENDOR|DEVREQ), 0,0,
                           &db.iData, sizeof(db.iData), HZ);
    if (iReturn == sizeof(db.iData))
    {
        copy_to_user(pDB, &db, sizeof(db));
        iReturn = U14ERR_NOERROR;
    }
    else
        dev_err(&pdx->interface->dev, "%s failed, code %d", __func__, iReturn);

    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}

/****************************************************************************
** DbgStopLoop
**
** Stop any never-ending debug loop, we just call Get1401State for USB
**
****************************************************************************/
int DbgStopLoop(DEVICE_EXTENSION *pdx)
{
    int iReturn;
    unsigned int uState, uErr;

    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev, "%s", __func__);
    iReturn = Get1401State(pdx, &uState, &uErr);
    mutex_unlock(&pdx->io_mutex);

    return iReturn;
}


/****************************************************************************
** SetCircular
**
** Sets up a transfer area record for circular transfers. If the area is
** already set, we attempt to unset it. Unsetting will fail if the area is
** booked and a transfer to that area is in progress. Otherwise, we will
** release the area and re-assign it.
****************************************************************************/
int SetCircular(DEVICE_EXTENSION *pdx, TRANSFERDESC __user *pTD)
{
    int iReturn;
    bool bToHost;
    TRANSFERDESC td;
    copy_from_user(&td, pTD, sizeof(td));
    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev,"%s area:%d, size:%08x", __func__, td.wAreaNum, td.dwLength);
    bToHost = td.eSize != 0;    // this is used as the tohost flag

    // The strange cast is done so that we don't get warnings in 32-bit linux about the size of the
    // pointer. The pointer is always passed as a 64-bit object so that we don't have problems using
    // a 32-bit program on a 64-bit system. unsigned long is 64-bits on a 64-bit system.
    iReturn = SetArea(pdx, td.wAreaNum, (char __user *)((unsigned long)td.lpvBuff), td.dwLength, true, bToHost);
    mutex_unlock(&pdx->io_mutex);
    return iReturn;
}

/****************************************************************************
** GetCircBlock
**
** Return the next available block of circularly-transferred data.
****************************************************************************/
int GetCircBlock(DEVICE_EXTENSION *pdx, TCIRCBLOCK __user* pCB)
{
    int iReturn = U14ERR_NOERROR;
    unsigned int nArea;
    TCIRCBLOCK cb;
    dev_dbg(&pdx->interface->dev, "%s", __func__);
    copy_from_user(&cb, pCB, sizeof(cb));
    mutex_lock(&pdx->io_mutex);

    nArea = cb.nArea;                       // Retrieve parameters first
    cb.dwOffset = 0;                        // set default result (nothing)
    cb.dwSize = 0;

    if (nArea < MAX_TRANSAREAS)             // The area number must be OK
    {
        TRANSAREA* pArea = &pdx->rTransDef[nArea];  // Pointer to relevant info
        spin_lock_irq(&pdx->stagedLock);            // Lock others out

        if ((pArea->bUsed) && (pArea->bCircular) && // Must be circular area
            (pArea->bCircToHost))                   // For now at least must be to host
        {
            if (pArea->aBlocks[0].dwSize > 0)       // Got anything?
            {
                cb.dwOffset = pArea->aBlocks[0].dwOffset;
                cb.dwSize = pArea->aBlocks[0].dwSize;
                dev_dbg(&pdx->interface->dev, "%s return block 0: %d bytes at %d", __func__, cb.dwSize, cb.dwOffset);
            }
        }
        else
            iReturn = U14ERR_NOTSET;

        spin_unlock_irq(&pdx->stagedLock);
    }
    else
        iReturn = U14ERR_BADAREA;

    copy_to_user(pCB, &cb, sizeof(cb));
    mutex_unlock(&pdx->io_mutex);
    return iReturn;
}


/****************************************************************************
** FreeCircBlock
**
** Frees a block of circularly-transferred data and returns the next one.
****************************************************************************/
int FreeCircBlock(DEVICE_EXTENSION *pdx, TCIRCBLOCK __user* pCB)
{
    int iReturn = U14ERR_NOERROR;
    unsigned int nArea, uStart, uSize;
    TCIRCBLOCK cb;
    dev_dbg(&pdx->interface->dev, "%s", __func__);
    copy_from_user(&cb, pCB, sizeof(cb));
    mutex_lock(&pdx->io_mutex);

    nArea = cb.nArea;                               // Retrieve parameters first
    uStart = cb.dwOffset;
    uSize = cb.dwSize;
    cb.dwOffset = 0;                                // then set default result (nothing)
    cb.dwSize = 0;

    if (nArea < MAX_TRANSAREAS)                     // The area number must be OK
    {
        TRANSAREA* pArea = &pdx->rTransDef[nArea];  // Pointer to relevant info
        spin_lock_irq(&pdx->stagedLock);            // Lock others out

        if ((pArea->bUsed) && (pArea->bCircular) && // Must be circular area
            (pArea->bCircToHost))                   // For now at least must be to host
        {
            bool bWaiting = false;

            if ((pArea->aBlocks[0].dwSize >= uSize) &&  // Got anything?
                (pArea->aBlocks[0].dwOffset == uStart)) // Must be legal data
            {
                pArea->aBlocks[0].dwSize -= uSize;
                pArea->aBlocks[0].dwOffset += uSize;
                if (pArea->aBlocks[0].dwSize == 0)  // Have we emptied this block?
                {
                    if (pArea->aBlocks[1].dwSize)   // Is there a second block?
                    {
                        pArea->aBlocks[0] = pArea->aBlocks[1];  // Copy down block 2 data
                        pArea->aBlocks[1].dwSize = 0;   // and mark the second block as unused
                        pArea->aBlocks[1].dwOffset = 0;
                    }
                    else
                        pArea->aBlocks[0].dwOffset = 0;
                }

                dev_dbg(&pdx->interface->dev, "%s free %d bytes at %d, return %d bytes at %d, wait=%d",
                         __func__, uSize, uStart, pArea->aBlocks[0].dwSize, pArea->aBlocks[0].dwOffset, pdx->bXFerWaiting);

                // Return the next available block of memory as well
                if (pArea->aBlocks[0].dwSize > 0)   // Got anything?
                {
                    cb.dwOffset = pArea->aBlocks[0].dwOffset;
                    cb.dwSize = pArea->aBlocks[0].dwSize;
                }

                bWaiting = pdx->bXFerWaiting;
                if (bWaiting && pdx->bStagedUrbPending)
                {
                    dev_err(&pdx->interface->dev, "%s ERROR: waiting xfer and staged Urb pending!", __func__);
                    bWaiting = false;
                }
            }
            else
            {
                dev_err(&pdx->interface->dev, "%s ERROR: freeing %d bytes at %d, block 0 is %d bytes at %d",
                         __func__, uSize, uStart, pArea->aBlocks[0].dwSize, pArea->aBlocks[0].dwOffset);
                 iReturn = U14ERR_NOMEMORY;
            }

            // If we have one, kick off pending transfer
            if (bWaiting)                       // Got a block xfer waiting?
            {
                int RWMStat = ReadWriteMem(pdx, !pdx->rDMAInfo.bOutWard,
                                      pdx->rDMAInfo.wIdent, pdx->rDMAInfo.dwOffset, pdx->rDMAInfo.dwSize);
                if (RWMStat != U14ERR_NOERROR)
                    dev_err(&pdx->interface->dev, "%s rw setup failed %d", __func__, RWMStat);
            }
        }
        else
            iReturn = U14ERR_NOTSET;

        spin_unlock_irq(&pdx->stagedLock);
    }
    else
        iReturn = U14ERR_BADAREA;

    copy_to_user(pCB, &cb, sizeof(cb));
    mutex_unlock(&pdx->io_mutex);
    return iReturn;
}



ced_ioctl.h0000664000175000017500000002522311722662056011623 0ustar  greggreg/* ced_ioctl.h
 IOCTL calls for the CED1401 driver
 Copyright (C) 2010 Cambridge Electronic Design Ltd
 Author Greg P Smith (greg@ced.co.uk)

 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
 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/
#ifndef __CED_IOCTL_H__
#define __CED_IOCTL_H__
#include <asm/ioctl.h>

/// dma modes, only MODE_CHAR and MODE_LINEAR are used in this driver
#define MODE_CHAR           0
#define MODE_LINEAR         1

/****************************************************************************
** TypeDefs
*****************************************************************************/

typedef unsigned short TBLOCKENTRY; // index the blk transfer table 0-7

typedef struct TransferDesc
{
    long long   lpvBuff;            // address of transfer area (for 64 or 32 bit)
    unsigned int dwLength;          // length of the area
    TBLOCKENTRY wAreaNum;           // number of transfer area to set up
    short       eSize;              // element size - is tohost flag for circular
} TRANSFERDESC;

typedef TRANSFERDESC*   LPTRANSFERDESC;

typedef struct TransferEvent
{
    unsigned int dwStart;           // offset into the area
    unsigned int dwLength;          // length of the region
    unsigned short wAreaNum;        // the area number
    unsigned short wFlags;          // bit 0 set for toHost
    int iSetEvent;                  // could be dummy in LINUX
} TRANSFEREVENT;

#define MAX_TRANSFER_SIZE  0x4000       /* Maximum data bytes per IRP */
#define MAX_AREA_LENGTH    0x100000     /* Maximum size of transfer area */
#define MAX_TRANSAREAS 8                /* definitions for dma set up  */

typedef struct TGetSelfTest
{
    int code;                           // self-test error code
    int x,y;                            // additional information
} TGET_SELFTEST;

/// Debug block used for several commands. Not all fields are used for all commands.
typedef struct TDbgBlock
{
    int iAddr;                          // the address in the 1401
    int iRepeats;                       // number of repeats
    int iWidth;                         // width in bytes 1, 2, 4
    int iDefault;                       // default value
    int iMask;                          // mask to apply
    int iData;                          // data for poke, result for peek
} TDBGBLOCK;

/// Used to collect information about a circular block from the device driver
typedef struct TCircBlock
{
    unsigned int nArea;                 // the area to collect information from
    unsigned int dwOffset;              // offset into the area to the available block
    unsigned int dwSize;                // size of the area
} TCIRCBLOCK;

/// Used to clollect the 1401 status
typedef struct TCSBlock
{
    unsigned int uiState;
    unsigned int uiError;
} TCSBLOCK;

// As seen by the user, an ioctl call looks like:
// int ioctl(int fd, unsigned long cmd, char* argp);
// We will then have all sorts of variants on this that can be used
// to pass stuff to our driver. We will generate macros for each type
// of call so as to provide some sort of type safety in the calling:
#define CED_MAGIC_IOC 0xce

// NBNB: READ and WRITE are from the point of view of the device, not user.
typedef struct ced_ioc_string
{
    int nChars;
    char buffer[256];
} CED_IOC_STRING;

#define  IOCTL_CED_SENDSTRING(n)        _IOC(_IOC_WRITE, CED_MAGIC_IOC, 2, n)

#define  IOCTL_CED_RESET1401            _IO(CED_MAGIC_IOC, 3)
#define  IOCTL_CED_GETCHAR              _IO(CED_MAGIC_IOC, 4)
#define  IOCTL_CED_SENDCHAR             _IO(CED_MAGIC_IOC, 5)
#define  IOCTL_CED_STAT1401             _IO(CED_MAGIC_IOC, 6)
#define  IOCTL_CED_LINECOUNT            _IO(CED_MAGIC_IOC, 7)
#define  IOCTL_CED_GETSTRING(nMax)      _IOC(_IOC_READ, CED_MAGIC_IOC, 8, nMax)

#define  IOCTL_CED_SETTRANSFER          _IOW(CED_MAGIC_IOC, 11, TRANSFERDESC)
#define  IOCTL_CED_UNSETTRANSFER        _IO(CED_MAGIC_IOC, 12)
#define  IOCTL_CED_SETEVENT             _IOW(CED_MAGIC_IOC,13, TRANSFEREVENT)
#define  IOCTL_CED_GETOUTBUFSPACE       _IO(CED_MAGIC_IOC, 14)
#define  IOCTL_CED_GETBASEADDRESS       _IO(CED_MAGIC_IOC, 15)
#define  IOCTL_CED_GETDRIVERREVISION    _IO(CED_MAGIC_IOC, 16)

#define  IOCTL_CED_GETTRANSFER          _IOR(CED_MAGIC_IOC,17, TGET_TX_BLOCK)
#define  IOCTL_CED_KILLIO1401           _IO(CED_MAGIC_IOC,18)
#define  IOCTL_CED_BLKTRANSSTATE        _IO(CED_MAGIC_IOC,19)

#define  IOCTL_CED_STATEOF1401          _IO(CED_MAGIC_IOC,23)
#define  IOCTL_CED_GRAB1401             _IO(CED_MAGIC_IOC,25)
#define  IOCTL_CED_FREE1401             _IO(CED_MAGIC_IOC,26)
#define  IOCTL_CED_STARTSELFTEST        _IO(CED_MAGIC_IOC,31)
#define  IOCTL_CED_CHECKSELFTEST        _IOR(CED_MAGIC_IOC,32, TGET_SELFTEST)
#define  IOCTL_CED_TYPEOF1401           _IO(CED_MAGIC_IOC,33)
#define  IOCTL_CED_TRANSFERFLAGS        _IO(CED_MAGIC_IOC,34)

#define  IOCTL_CED_DBGPEEK              _IOW(CED_MAGIC_IOC,35, TDBGBLOCK)
#define  IOCTL_CED_DBGPOKE              _IOW(CED_MAGIC_IOC,36, TDBGBLOCK)
#define  IOCTL_CED_DBGRAMPDATA          _IOW(CED_MAGIC_IOC,37, TDBGBLOCK)
#define  IOCTL_CED_DBGRAMPADDR          _IOW(CED_MAGIC_IOC,38, TDBGBLOCK)
#define  IOCTL_CED_DBGGETDATA           _IOR(CED_MAGIC_IOC,39, TDBGBLOCK)
#define  IOCTL_CED_DBGSTOPLOOP          _IO(CED_MAGIC_IOC,40)
#define  IOCTL_CED_FULLRESET            _IO(CED_MAGIC_IOC,41)
#define  IOCTL_CED_SETCIRCULAR          _IOW(CED_MAGIC_IOC,42, TRANSFERDESC)
#define  IOCTL_CED_GETCIRCBLOCK         _IOWR(CED_MAGIC_IOC,43, TCIRCBLOCK)
#define  IOCTL_CED_FREECIRCBLOCK        _IOWR(CED_MAGIC_IOC,44, TCIRCBLOCK)
#define  IOCTL_CED_WAITEVENT            _IO(CED_MAGIC_IOC, 45)
#define  IOCTL_CED_TESTEVENT            _IO(CED_MAGIC_IOC, 46)

#ifndef __KERNEL__
// If nothing said about return value, it is a U14ERR_... error code (U14ERR_NOERROR for none)
inline int CED_SendString(int fh, const char* szText, int n){return ioctl(fh, IOCTL_CED_SENDSTRING(n), szText);}

inline int CED_Reset1401(int fh){return ioctl(fh, IOCTL_CED_RESET1401);}

inline int CED_GetChar(int fh){return ioctl(fh, IOCTL_CED_GETCHAR);}
// Return the singe character or a -ve error code.

inline int CED_Stat1401(int fh){return ioctl(fh, IOCTL_CED_STAT1401);}
// Return character count in input buffer

inline int CED_SendChar(int fh, char c){return ioctl(fh, IOCTL_CED_SENDCHAR, c);}

inline int CED_LineCount(int fh){return ioctl(fh, IOCTL_CED_LINECOUNT);}

inline int CED_GetString(int fh, char* szText, int nMax){return ioctl(fh, IOCTL_CED_GETSTRING(nMax), szText);}
// return the count of characters returned. If the string was terminated by CR or 0, then the 0 is part
// of the count. Otherwise, we will add a zero if there is room, but it is not included in the count.
// The return value is 0 if there was nothing to read.

inline int CED_GetOutBufSpace(int fh){return ioctl(fh, IOCTL_CED_GETOUTBUFSPACE);}
// returns space in the output buffer.

inline int CED_GetBaseAddress(int fh){return ioctl(fh, IOCTL_CED_GETBASEADDRESS);}
// This always returns -1 as not implemented.

inline int CED_GetDriverRevision(int fh){return ioctl(fh, IOCTL_CED_GETDRIVERREVISION);}
// returns the major revision <<16 | minor revision.

inline int CED_SetTransfer(int fh, TRANSFERDESC* pTD){return ioctl(fh, IOCTL_CED_SETTRANSFER, pTD);}

inline int CED_UnsetTransfer(int fh, int nArea){return ioctl(fh, IOCTL_CED_UNSETTRANSFER, nArea);}

inline int CED_SetEvent(int fh, TRANSFEREVENT* pTE){return ioctl(fh, IOCTL_CED_SETEVENT, pTE);}

inline int CED_GetTransfer(int fh, TGET_TX_BLOCK* pTX){return ioctl(fh, IOCTL_CED_GETTRANSFER, pTX);}

inline int CED_KillIO1401(int fh){return ioctl(fh, IOCTL_CED_KILLIO1401);}

inline int CED_BlkTransState(int fh){return ioctl(fh, IOCTL_CED_BLKTRANSSTATE);}
// returns 0 if no active DMA, 1 if active

inline int CED_StateOf1401(int fh){return ioctl(fh, IOCTL_CED_STATEOF1401);}

inline int CED_Grab1401(int fh){return ioctl(fh, IOCTL_CED_GRAB1401);}
inline int CED_Free1401(int fh){return ioctl(fh, IOCTL_CED_FREE1401);}

inline int CED_StartSelfTest(int fh){return ioctl(fh, IOCTL_CED_STARTSELFTEST);}
inline int CED_CheckSelfTest(int fh, TGET_SELFTEST* pGST){return ioctl(fh, IOCTL_CED_CHECKSELFTEST, pGST);}

inline int CED_TypeOf1401(int fh){return ioctl(fh, IOCTL_CED_TYPEOF1401);}
inline int CED_TransferFlags(int fh){return ioctl(fh, IOCTL_CED_TRANSFERFLAGS);}

inline int CED_DbgPeek(int fh, TDBGBLOCK* pDB){return ioctl(fh, IOCTL_CED_DBGPEEK, pDB);}
inline int CED_DbgPoke(int fh, TDBGBLOCK* pDB){return ioctl(fh, IOCTL_CED_DBGPOKE, pDB);}
inline int CED_DbgRampData(int fh, TDBGBLOCK* pDB){return ioctl(fh, IOCTL_CED_DBGRAMPDATA, pDB);}
inline int CED_DbgRampAddr(int fh, TDBGBLOCK* pDB){return ioctl(fh, IOCTL_CED_DBGRAMPADDR, pDB);}
inline int CED_DbgGetData(int fh, TDBGBLOCK* pDB){return ioctl(fh, IOCTL_CED_DBGGETDATA, pDB);}
inline int CED_DbgStopLoop(int fh){return ioctl(fh, IOCTL_CED_DBGSTOPLOOP);}

inline int CED_FullReset(int fh){return ioctl(fh, IOCTL_CED_FULLRESET);}

inline int CED_SetCircular(int fh, TRANSFERDESC* pTD){return ioctl(fh, IOCTL_CED_SETCIRCULAR, pTD);}
inline int CED_GetCircBlock(int fh, TCIRCBLOCK* pCB){return ioctl(fh, IOCTL_CED_GETCIRCBLOCK, pCB);}
inline int CED_FreeCircBlock(int fh, TCIRCBLOCK* pCB){return ioctl(fh, IOCTL_CED_FREECIRCBLOCK, pCB);}

inline int CED_WaitEvent(int fh, int nArea, int msTimeOut){return ioctl(fh, IOCTL_CED_WAITEVENT, (nArea & 0xff)|(msTimeOut << 8));}
inline int CED_TestEvent(int fh, int nArea){return ioctl(fh, IOCTL_CED_TESTEVENT, nArea);}
#endif

#ifdef NOTWANTEDYET
#define  IOCTL_CED_REGCALLBACK          _IO(CED_MAGIC_IOC,9)    // Not used
#define  IOCTL_CED_GETMONITORBUF        _IO(CED_MAGIC_IOC,10)   // Not used

#define  IOCTL_CED_BYTECOUNT            _IO(CED_MAGIC_IOC,20)   // Not used
#define  IOCTL_CED_ZEROBLOCKCOUNT       _IO(CED_MAGIC_IOC,21)   // Not used
#define  IOCTL_CED_STOPCIRCULAR         _IO(CED_MAGIC_IOC,22)   // Not used

#define  IOCTL_CED_REGISTERS1401        _IO(CED_MAGIC_IOC,24)   // Not used
#define  IOCTL_CED_STEP1401             _IO(CED_MAGIC_IOC,27)   // Not used
#define  IOCTL_CED_SET1401REGISTERS     _IO(CED_MAGIC_IOC,28)   // Not used
#define  IOCTL_CED_STEPTILL1401         _IO(CED_MAGIC_IOC,29)   // Not used
#define  IOCTL_CED_SETORIN              _IO(CED_MAGIC_IOC,30)   // Not used

#endif

// __CED_IOCTL_H__
#endif
Makefile0000644000175000017500000000051711500465761011160 0ustar  greggregobj-m := cedusb.o
cedusb-objs := usb1401.o ced_ioc.o
KDIR := /lib/modules/$(shell uname -r)/build
PWD := $(shell pwd)
KBUILD_EXTRA_SYMBOLS := $(PWD)
EXTRA_CFLAGS = -I/home/greg/devel/use1432/use1432 -I/home/greg/devel/QT/Try1401/Try1401
all:
	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) modules

clean:
	$(MAKE) -C $(KDIR) SUBDIRS=$(PWD) clean

usb1401.c0000664000175000017500000020306211722662011010756 0ustar  greggreg/***********************************************************************************
 CED1401 usb driver. This basic loading is based on the usb-skeleton.c code that is:
 Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com)
 There is not a great deal of the skeleton left.

 All the remainder dealing specifically with the CED1401 is based on drivers written
 by CED for other systems (mainly Windows) and is:
 Copyright (C) 2010 Cambridge Electronic Design Ltd
 Author Greg P Smith (greg@ced.co.uk)

 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
 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.


Endpoints
*********
There are 4 endpoints plus the control endpoint in the standard interface
provided by most 1401s. The control endpoint is used for standard USB requests,
plus various CED-specific transactions such as start self test, debug and get
the 1401 status. The other endpoints are:

 1 Characters to the 1401
 2 Characters from the 1401
 3 Block data to the 1401
 4 Block data to the host.

inside the driver these are indexed as an array from 0 to 3, transactions
over the control endpoint are carried out using a separate mechanism. The
use of the endpoints is mostly straightforward, with the driver issuing
IO request packets (IRPs) as required to transfer data to and from the 1401.
The handling of endpoint 2 is different because it is used for characters
from the 1401, which can appear spontaneously and without any other driver
activity - for example to repeatedly request DMA transfers in Spike2. The
desired effect is achieved by using an interrupt endpoint which can be
polled to see if it has data available, and writing the driver so that it
always maintains a pending read IRP from that endpoint which will read the
character data and terminate as soon as the 1401 makes data available. This
works very well, some care is taken with when you kick off this character
read IRP to avoid it being active when it is not wanted but generally it
is running all the time.

In the 2270, there are only three endpoints plus the control endpoint. In
addition to the transactions mentioned above, the control endpoint is used
to transfer character data to the 1401. The other endpoints are used as:

 1 Characters from the 1401
 2 Block data to the 1401
 3 Block data to the host.

The type of interface available is specified by the interface subclass field
in the interface descriptor provided by the 1401. See the USB_INT_ constants
for the values that this field can hold.

****************************************************************************
Linux implementation

Although Linux Device Drivers (3rd Edition) was a major source of information,
it is very out of date. A lot of information was gleaned from the latest
usb_skeleton.c code (you need to download the kernel sources to get this).

To match the Windows version, everything is done using ioctl calls. All the
device state is held in the DEVICE_EXTENSION (named to match Windows use).
Block transfers are done by using get_user_pages() to pin down a list of
pages that we hold a pointer to in the device driver. We also allocate a
coherent transfer buffer of size STAGED_SZ (this must be a multiple of the
bulk endpoint size so that the 1401 does not realise that we break large
transfers down into smaller pieces). We use kmap_atomic() to get a kernel
va for each page, as it is required, for copying; see CopyUserSpace().

All character and data transfers are done using asynchronous IO. All Urbs are
tracked by anchoring them. Status and debug ioctls are implemented with the
synchronous non-Urb based transfers.
*/

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/kref.h>
#include <linux/uaccess.h>
#include <linux/usb.h>
#include <linux/mutex.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/version.h>

#include "usb1401.h"

/* Define these values to match your devices */
#define USB_CED_VENDOR_ID	0x0525
#define USB_CED_PRODUCT_ID	0xa0f0

/* table of devices that work with this driver */
static const struct usb_device_id ced_table[] =
{
    { USB_DEVICE(USB_CED_VENDOR_ID, USB_CED_PRODUCT_ID) },
    { }					/* Terminating entry */
};
MODULE_DEVICE_TABLE(usb, ced_table);


/* Get a minor range for your devices from the usb maintainer */
#define USB_CED_MINOR_BASE	192

/* our private defines. if this grows any larger, use your own .h file */
#define MAX_TRANSFER		(PAGE_SIZE - 512)
/* MAX_TRANSFER is chosen so that the VM is not stressed by
   allocations > PAGE_SIZE and the number of packets in a page
   is an integer 512 is the largest possible packet on EHCI */
#define WRITES_IN_FLIGHT	8
/* arbitrarily chosen */


static struct usb_driver ced_driver;

static void ced_delete(struct kref *kref)
{
    DEVICE_EXTENSION *pdx = to_DEVICE_EXTENSION(kref);

    // Free up the output buffer, then free the output urb. Note that the interface member
    // of pdx will probably be NULL, so cannot be used to get to dev.
    usb_free_coherent(pdx->udev, OUTBUF_SZ, pdx->pCoherCharOut, pdx->pUrbCharOut->transfer_dma);
    usb_free_urb(pdx->pUrbCharOut);

    // Do the same for chan input
    usb_free_coherent(pdx->udev, INBUF_SZ, pdx->pCoherCharIn, pdx->pUrbCharIn->transfer_dma);
    usb_free_urb(pdx->pUrbCharIn);

    // Do the same for the block transfers
    usb_free_coherent(pdx->udev, STAGED_SZ, pdx->pCoherStagedIO, pdx->pStagedUrb->transfer_dma);
    usb_free_urb(pdx->pStagedUrb);

    usb_put_dev(pdx->udev);
    kfree(pdx);
}

// This is the driver end of the open() call from user space.
static int ced_open(struct inode *inode, struct file *file)
{
    DEVICE_EXTENSION *pdx;
    int retval = 0;
    int subminor = iminor(inode);
    struct usb_interface* interface = usb_find_interface(&ced_driver, subminor);
    if (!interface)
    {
        err("%s - error, can't find device for minor %d", __func__, subminor);
        retval = -ENODEV;
        goto exit;
    }

    pdx = usb_get_intfdata(interface);
    if (!pdx)
    {
        retval = -ENODEV;
        goto exit;
    }

    dev_dbg(&interface->dev, "%s got pdx", __func__);

    /* increment our usage count for the device */
    kref_get(&pdx->kref);

    /* lock the device to allow correctly handling errors
     * in resumption */
    mutex_lock(&pdx->io_mutex);

    if (!pdx->open_count++)
    {
        retval = usb_autopm_get_interface(interface);
        if (retval)
        {
            pdx->open_count--;
            mutex_unlock(&pdx->io_mutex);
            kref_put(&pdx->kref, ced_delete);
            goto exit;
        }
    }
    else
    {   //uncomment this block if you want exclusive open
        dev_err(&interface->dev, "%s fail: already open", __func__);
		retval = -EBUSY;
		pdx->open_count--;
		mutex_unlock(&pdx->io_mutex);
		kref_put(&pdx->kref, ced_delete);
		goto exit;
	}
    /* prevent the device from being autosuspended */

    /* save our object in the file's private structure */
    file->private_data = pdx;
    mutex_unlock(&pdx->io_mutex);

exit:
    return retval;
}

static int ced_release(struct inode *inode, struct file *file)
{
    DEVICE_EXTENSION *pdx = file->private_data;
    if (pdx == NULL)
        return -ENODEV;

    dev_dbg(&pdx->interface->dev,"%s called", __func__);
    mutex_lock(&pdx->io_mutex);
    if (!--pdx->open_count && pdx->interface)   // Allow autosuspend
        usb_autopm_put_interface(pdx->interface);
    mutex_unlock(&pdx->io_mutex);

    kref_put(&pdx->kref, ced_delete);  // decrement the count on our device
    return 0;
}

static int ced_flush(struct file *file, fl_owner_t id)
{
    int res;
    DEVICE_EXTENSION *pdx = file->private_data;
    if (pdx == NULL)
        return -ENODEV;

    dev_dbg(&pdx->interface->dev,"%s char in pend=%d", __func__, pdx->bReadCharsPending);

    /* wait for io to stop */
    mutex_lock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev,"%s got io_mutex", __func__);
    ced_draw_down(pdx);

    /* read out errors, leave subsequent opens a clean slate */
    spin_lock_irq(&pdx->err_lock);
    res = pdx->errors ? (pdx->errors == -EPIPE ? -EPIPE : -EIO) : 0;
    pdx->errors = 0;
    spin_unlock_irq(&pdx->err_lock);

    mutex_unlock(&pdx->io_mutex);
    dev_dbg(&pdx->interface->dev,"%s exit reached", __func__);

    return res;
}


static ssize_t ced_read(struct file *file, char *buffer, size_t count,
                        loff_t *ppos)
{
    DEVICE_EXTENSION *pdx = file->private_data;
    dev_err(&pdx->interface->dev, "%s called: use ioctl for cedusb", __func__);
    return 0;           // as we do not do reads this way
}

static ssize_t ced_write(struct file *file, const char *user_buffer,
                         size_t count, loff_t *ppos)
{
    DEVICE_EXTENSION *pdx = file->private_data;
    dev_err(&pdx->interface->dev, "%s called: use ioctl for cedusb", __func__);
    return 0;
}

/***************************************************************************
** CanAcceptIoRequests
** If the device is removed, interface is set NULL. We also clear our pointer
** from the interface, so we should make sure that pdx is not NULL. This will
** not help with a device extension held by a file.
** return true if can accept new io requests, else false
*/
static bool CanAcceptIoRequests(DEVICE_EXTENSION* pdx)
{
    return pdx && pdx->interface;	        // Can we accept IO requests
}

/****************************************************************************
** Callback routine to complete writes. This may need to fire off another
** urb to complete the transfer.
****************************************************************************/
static void ced_writechar_callback(struct urb* pUrb)
{
    DEVICE_EXTENSION *pdx = pUrb->context;
    int nGot = pUrb->actual_length;             // what we transferred

    if (pUrb->status)
    {                                           // sync/async unlink faults aren't errors
        if (!(pUrb->status == -ENOENT || pUrb->status == -ECONNRESET || pUrb->status == -ESHUTDOWN))
        {
            dev_err(&pdx->interface->dev, "%s - nonzero write bulk status received: %d", __func__, pUrb->status);
        }

        spin_lock(&pdx->err_lock);
        pdx->errors = pUrb->status;
        spin_unlock(&pdx->err_lock);
        nGot = 0;                               //  and tidy up again if so

        spin_lock(&pdx->charOutLock);           // already at irq level
        pdx->dwOutBuffGet = 0;                  // Reset the output buffer
        pdx->dwOutBuffPut = 0;
        pdx->dwNumOutput = 0;                   // Clear the char count
        pdx->bPipeError[0] = 1;                 // Flag an error for later
        pdx->bSendCharsPending = false;         // Allow other threads again
        spin_unlock(&pdx->charOutLock);         // already at irq level
        dev_dbg(&pdx->interface->dev, "%s - char out done, 0 chars sent", __func__);
    }
    else
    {
        dev_dbg(&pdx->interface->dev, "%s - char out done, %d chars sent", __func__, nGot);
        spin_lock(&pdx->charOutLock);           // already at irq level
        pdx->dwNumOutput -= nGot;               // Now adjust the char send buffer
        pdx->dwOutBuffGet += nGot;              // to match what we did
        if (pdx->dwOutBuffGet >= OUTBUF_SZ)     // Can't do this any earlier as data could be overwritten
            pdx->dwOutBuffGet = 0;

        if (pdx->dwNumOutput > 0)               // if more to be done...
        {
            int nPipe = 0;                      // The pipe number to use
            int iReturn;
            char* pDat = &pdx->outputBuffer[pdx->dwOutBuffGet];
            unsigned int dwCount = pdx->dwNumOutput;     // maximum to send
            if ((pdx->dwOutBuffGet+dwCount) > OUTBUF_SZ)    // does it cross buffer end?
                dwCount = OUTBUF_SZ - pdx->dwOutBuffGet;
            spin_unlock(&pdx->charOutLock);             // we are done with stuff that changes
            memcpy(pdx->pCoherCharOut, pDat, dwCount);  // copy output data to the buffer
            usb_fill_bulk_urb(pdx->pUrbCharOut, pdx->udev,
                              usb_sndbulkpipe(pdx->udev, pdx->epAddr[0]),
                              pdx->pCoherCharOut, dwCount, ced_writechar_callback, pdx);
            pdx->pUrbCharOut->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
            usb_anchor_urb(pdx->pUrbCharOut, &pdx->submitted);   // in case we need to kill it
            iReturn = usb_submit_urb(pdx->pUrbCharOut, GFP_ATOMIC);
            dev_dbg(&pdx->interface->dev, "%s n=%d>%s<", __func__, dwCount, pDat);
            spin_lock(&pdx->charOutLock);       // grab lock for errors
            if (iReturn)
            {
                pdx->bPipeError[nPipe] = 1;     // Flag an error to be handled later
                pdx->bSendCharsPending = false; // Allow other threads again
                usb_unanchor_urb(pdx->pUrbCharOut);
                dev_err(&pdx->interface->dev, "%s usb_submit_urb() returned %d", __func__, iReturn);
          }
        }
        else
            pdx->bSendCharsPending = false;     // Allow other threads again
        spin_unlock(&pdx->charOutLock);         // already at irq level
    }
}

/****************************************************************************
** SendChars
** Transmit the characters in the output buffer to the 1401. This may need
** breaking down into multiple transfers.
****************************************************************************/
int SendChars(DEVICE_EXTENSION* pdx)
{
    int iReturn = U14ERR_NOERROR;

    spin_lock_irq(&pdx->charOutLock);                       // Protect ourselves

    if ((!pdx->bSendCharsPending) &&                        // Not currently sending
        (pdx->dwNumOutput > 0) &&                           //  has characters to output
        (CanAcceptIoRequests(pdx)))                         //  and current activity is OK
    {
        unsigned int dwCount = pdx->dwNumOutput;            // Get a copy of the character count
        pdx->bSendCharsPending = true;                      // Set flag to lock out other threads

        dev_dbg(&pdx->interface->dev, "Send %d chars to 1401, EP0 flag %d\n", dwCount, pdx->nPipes == 3);
        // If we have only 3 end points we must send the characters to the 1401 using EP0.
        if (pdx->nPipes == 3)
        {
            // For EP0 character transmissions to the 1401, we have to hang about until they
            // are gone, as otherwise without more character IO activity they will never go.
            unsigned int count = dwCount;                   // Local char counter
            unsigned int index = 0;                         // The index into the char buffer

            spin_unlock_irq(&pdx->charOutLock);             // Free spinlock as we call USBD

            while ((count > 0) && (iReturn == U14ERR_NOERROR))
            {
                // We have to break the transfer up into 64-byte chunks because of a 2270 problem
                int n = count > 64 ? 64 : count;            // Chars for this xfer, max of 64
                int nSent = usb_control_msg(pdx->udev,
                                            usb_sndctrlpipe(pdx->udev,0), // use end point 0
                                            DB_CHARS,                   // bRequest
                                            (H_TO_D|VENDOR|DEVREQ),     // to the device, vendor request to the device
                                            0,0,                        // value and index are both 0
                                            &pdx->outputBuffer[index],  // where to send from
                                            n,                          // how much to send
                                            1000);                      // timeout in jiffies
                if (nSent <= 0)
                {
                    iReturn = nSent ? nSent : -ETIMEDOUT;   // if 0 chars says we timed out
                    dev_err(&pdx->interface->dev, "Send %d chars by EP0 failed: %d", n, iReturn);
                }
                else
                {
                    dev_dbg(&pdx->interface->dev, "Sent %d chars by EP0", n);
                    count -= nSent;
                    index += nSent;
                }
            }

            spin_lock_irq(&pdx->charOutLock);               // Protect pdx changes, released by general code
            pdx->dwOutBuffGet = 0;                          // so reset the output buffer
            pdx->dwOutBuffPut = 0;
            pdx->dwNumOutput = 0;                           // and clear the buffer count
            pdx->bSendCharsPending = false;                 // Allow other threads again
        }
        else
        {   // Here for sending chars normally - we hold the spin lock
            int nPipe = 0;                                  // The pipe number to use
            char* pDat = &pdx->outputBuffer[pdx->dwOutBuffGet];

            if ((pdx->dwOutBuffGet+dwCount) > OUTBUF_SZ)    // does it cross buffer end?
                dwCount = OUTBUF_SZ - pdx->dwOutBuffGet;
            spin_unlock_irq(&pdx->charOutLock);             // we are done with stuff that changes
            memcpy(pdx->pCoherCharOut, pDat, dwCount);      // copy output data to the buffer
            usb_fill_bulk_urb(pdx->pUrbCharOut, pdx->udev,
                              usb_sndbulkpipe(pdx->udev, pdx->epAddr[0]),
                              pdx->pCoherCharOut, dwCount, ced_writechar_callback, pdx);
            pdx->pUrbCharOut->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
            usb_anchor_urb(pdx->pUrbCharOut, &pdx->submitted);
            iReturn = usb_submit_urb(pdx->pUrbCharOut, GFP_KERNEL);
            spin_lock_irq(&pdx->charOutLock);       // grab lock for errors
            if (iReturn)
            {
                pdx->bPipeError[nPipe] = 1;         // Flag an error to be handled later
                pdx->bSendCharsPending = false;     // Allow other threads again
                usb_unanchor_urb(pdx->pUrbCharOut); // remove from list of active urbs
            }
        }
    }
    else
        if (pdx->bSendCharsPending && (pdx->dwNumOutput > 0))
            dev_dbg(&pdx->interface->dev, "SendChars bSendCharsPending:true");


    dev_dbg(&pdx->interface->dev, "SendChars exit code: %d", iReturn);
    spin_unlock_irq(&pdx->charOutLock);             // Now let go of the spinlock
    return iReturn;
}

/***************************************************************************
** CopyUserSpace
** This moves memory between pinned down user space and the pCoherStagedIO
** memory buffer we use for transfers. Copy n bytes in the directions that
** is defined by pdx->StagedRead. The user space is determined by the area
** in pdx->StagedId and the offset in pdx->StagedDone. The user
** area may well not start on a page boundary, so allow for that.
**
** We have a table of physical pages that describe the area, so we can use
** this to get a virtual address that the kernel can use.
**
** pdx  Is our device extension which holds all we know about the transfer.
** n    The number of bytes to move one way or the other.
***************************************************************************/
static void CopyUserSpace(DEVICE_EXTENSION *pdx, int n)
{
    unsigned int nArea = pdx->StagedId;
    if (nArea < MAX_TRANSAREAS)
    {
        TRANSAREA *pArea = &pdx->rTransDef[nArea];  // area to be used
        unsigned int dwOffset = pdx->StagedDone + pdx->StagedOffset + pArea->dwBaseOffset;
        char* pCoherBuf = pdx->pCoherStagedIO;      // coherent buffer
        if (!pArea->bUsed)
        {
            dev_err(&pdx->interface->dev, "%s area %d unused", __func__, nArea);
            return;
        }

        while (n)
        {
            int nPage = dwOffset >> PAGE_SHIFT;    // page number in table
            if (nPage < pArea->nPages)
            {
                char *pvAddress = (char*)kmap_atomic(pArea->pPages[nPage], KM_IRQ0);
                if (pvAddress)
                {
                    unsigned int uiPageOff = dwOffset & (PAGE_SIZE-1);   // offset into the page
                    size_t uiXfer = PAGE_SIZE - uiPageOff;         // max to transfer on this page
                    if (uiXfer > n)                         // limit byte count if too much
                        uiXfer = n;                         // for the page
                    if (pdx->StagedRead)
                        memcpy(pvAddress+uiPageOff, pCoherBuf, uiXfer);
                    else
                        memcpy(pCoherBuf, pvAddress+uiPageOff, uiXfer);
                    kunmap_atomic(pvAddress, KM_IRQ0);
                    dwOffset += uiXfer;
                    pCoherBuf += uiXfer;
                    n -= uiXfer;
                }
                else
                {
                    dev_err(&pdx->interface->dev, "%s did not map page %d", __func__, nPage);
                    return;
                }

            }
            else
            {
                dev_err(&pdx->interface->dev, "%s exceeded pages %d", __func__, nPage);
                return;
            }
        }
    }
    else
        dev_err(&pdx->interface->dev, "%s bad area %d", __func__, nArea);
}

// Forward declarations for stuff used circularly
static int StageChunk(DEVICE_EXTENSION *pdx);
/***************************************************************************
** ReadWrite_Complete
**
**  Completion routine for our staged read/write Irps
*/
static void staged_callback(struct urb* pUrb)
{
    DEVICE_EXTENSION *pdx = pUrb->context;
    unsigned int nGot = pUrb->actual_length;     // what we transferred
    bool bCancel = false;
    bool bRestartCharInput;             // used at the end

    spin_lock(&pdx->stagedLock);        // stop ReadWriteMem() action while this routine is running
    pdx->bStagedUrbPending = false;     // clear the flag for staged IRP pending

    if (pUrb->status)
    {   // sync/async unlink faults aren't errors
        if (!(pUrb->status == -ENOENT || pUrb->status == -ECONNRESET || pUrb->status == -ESHUTDOWN))
        {
            dev_err(&pdx->interface->dev, "%s - nonzero write bulk status received: %d", __func__, pUrb->status);
        }
        else
            dev_info(&pdx->interface->dev, "%s - staged xfer cancelled", __func__);

        spin_lock(&pdx->err_lock);
        pdx->errors = pUrb->status;
        spin_unlock(&pdx->err_lock);
        nGot = 0;                               //  and tidy up again if so
        bCancel = true;
    }
    else
    {
        dev_dbg(&pdx->interface->dev, "%s %d chars xferred", __func__, nGot);
        if (pdx->StagedRead)                    // if reading, save to user space
            CopyUserSpace(pdx, nGot);           // copy from buffer to user
        if (nGot == 0)
            dev_dbg(&pdx->interface->dev, "%s ZLP", __func__);
    }

    // Update the transfer length based on the TransferBufferLength value in the URB
    pdx->StagedDone += nGot;

    dev_dbg(&pdx->interface->dev, "%s, done %d bytes of %d", __func__, pdx->StagedDone, pdx->StagedLength);

    if ((pdx->StagedDone == pdx->StagedLength) ||       // If no more to do
        (bCancel))                                      // or this IRP was cancelled
    {
        TRANSAREA* pArea = &pdx->rTransDef[pdx->StagedId];    // Transfer area info
		dev_dbg(&pdx->interface->dev, "%s transfer done, bytes %d, cancel %d", __func__, pdx->StagedDone, bCancel);

        // Here is where we sort out what to do with this transfer if using a circular buffer. We have
        //  a completed transfer that can be assumed to fit into the transfer area. We should be able to
        //  add this to the end of a growing block or to use it to start a new block unless the code
        //  that calculates the offset to use (in ReadWriteMem) is totally duff.
        if ((pArea->bCircular) && (pArea->bCircToHost) && (!bCancel) &&  // Time to sort out circular buffer info?
            (pdx->StagedRead))                          // Only for tohost transfers for now
        {
            if (pArea->aBlocks[1].dwSize > 0)           // If block 1 is in use we must append to it
            {
                if (pdx->StagedOffset == (pArea->aBlocks[1].dwOffset + pArea->aBlocks[1].dwSize))
                {
                    pArea->aBlocks[1].dwSize += pdx->StagedLength;
                    dev_dbg(&pdx->interface->dev, "RWM_Complete, circ block 1 now %d bytes at %d",
                                                   pArea->aBlocks[1].dwSize, pArea->aBlocks[1].dwOffset);
                }
                else
                {
                    // Here things have gone very, very, wrong, but I cannot see how this can actually be achieved
                    pArea->aBlocks[1].dwOffset = pdx->StagedOffset;
                    pArea->aBlocks[1].dwSize = pdx->StagedLength;
                    dev_err(&pdx->interface->dev, "%s ERROR, circ block 1 re-started %d bytes at %d",
                                                   __func__, pArea->aBlocks[1].dwSize, pArea->aBlocks[1].dwOffset);
                }
            }
            else                                        // If block 1 is not used, we try to add to block 0
            {
                if (pArea->aBlocks[0].dwSize > 0)       // Got stored block 0 information?
                {                                       // Must append onto the existing block 0
                    if (pdx->StagedOffset == (pArea->aBlocks[0].dwOffset + pArea->aBlocks[0].dwSize))
                    {
                        pArea->aBlocks[0].dwSize += pdx->StagedLength;  // Just add this transfer in
                        dev_dbg(&pdx->interface->dev, "RWM_Complete, circ block 0 now %d bytes at %d",
                                                       pArea->aBlocks[0].dwSize, pArea->aBlocks[0].dwOffset);
                    }
                    else                                // If it doesn't append, put into new block 1
                    {
                        pArea->aBlocks[1].dwOffset = pdx->StagedOffset;
                        pArea->aBlocks[1].dwSize = pdx->StagedLength;
                        dev_dbg(&pdx->interface->dev, "RWM_Complete, circ block 1 started %d bytes at %d",
                                                       pArea->aBlocks[1].dwSize, pArea->aBlocks[1].dwOffset);
                    }
                }
                else                                    // No info stored yet, just save in block 0
                {
                    pArea->aBlocks[0].dwOffset = pdx->StagedOffset;
                    pArea->aBlocks[0].dwSize = pdx->StagedLength;
                    dev_dbg(&pdx->interface->dev, "RWM_Complete, circ block 0 started %d bytes at %d",
                                                   pArea->aBlocks[0].dwSize, pArea->aBlocks[0].dwOffset);
                }
            }
        }

        if (!bCancel)                                   // Don't generate an event if cancelled
        {
            dev_dbg(&pdx->interface->dev, "RWM_Complete,  bCircular %d, bToHost %d, eStart %d, eSize %d",
                                         pArea->bCircular, pArea->bEventToHost, pArea->dwEventSt, pArea->dwEventSz);
            if ((pArea->dwEventSz) &&                   // Set a user-mode event...
                (pdx->StagedRead == pArea->bEventToHost)) // ...on transfers in this direction?
            {
                int iWakeUp = 0;                        // assume
                // If we have completed the right sort of DMA transfer then set the event to notify
                //   the user code to wake up anyone that is waiting.
                if ((pArea->bCircular) &&               // Circular areas use a simpler test
                    (pArea->bCircToHost))               // only in supported direction
                {										// Is total data waiting up to size limit?
					unsigned int dwTotal = pArea->aBlocks[0].dwSize + pArea->aBlocks[1].dwSize;
                    iWakeUp = (dwTotal >= pArea->dwEventSz);
                }
                else
                {
                    unsigned int transEnd = pdx->StagedOffset + pdx->StagedLength;
                    unsigned int eventEnd = pArea->dwEventSt + pArea->dwEventSz;
                    iWakeUp = (pdx->StagedOffset < eventEnd) && (transEnd > pArea->dwEventSt);
                }

                if (iWakeUp)
                {
                    dev_dbg(&pdx->interface->dev, "About to set event to notify app");
                    wake_up_interruptible(&pArea->wqEvent); // wake up waiting processes
                    ++pArea->iWakeUp;                   // increment wakeup count
                }
            }
        }

        pdx->dwDMAFlag = MODE_CHAR;                     // Switch back to char mode before ReadWriteMem call

        if (!bCancel)                                   // Don't look for waiting transfer if cancelled
        {
            // If we have a transfer waiting, kick it off
            if (pdx->bXFerWaiting)                      // Got a block xfer waiting?
            {
                int iReturn;
                dev_info(&pdx->interface->dev, "*** RWM_Complete *** pending transfer will now be set up!!!");
                iReturn = ReadWriteMem(pdx, !pdx->rDMAInfo.bOutWard, pdx->rDMAInfo.wIdent, pdx->rDMAInfo.dwOffset, pdx->rDMAInfo.dwSize);

                if (iReturn)
                    dev_err(&pdx->interface->dev, "RWM_Complete rw setup failed %d", iReturn);
            }
        }

    }
    else                                                // Here for more to do
        StageChunk(pdx);                                // fire off the next bit

    // While we hold the stagedLock, see if we should reallow character input ints
    // Don't allow if cancelled, or if a new block has started or if there is a waiting block.
    // This feels wrong as we should ask which spin lock protects dwDMAFlag.
    bRestartCharInput = !bCancel && (pdx->dwDMAFlag == MODE_CHAR) && !pdx->bXFerWaiting;

    spin_unlock(&pdx->stagedLock);                      // Finally release the lock again

    // This is not correct as dwDMAFlag is protected by the staged lock, but it is treated
    // in Allowi as if it were protected by the char lock. In any case, most systems will
    // not be upset by char input during DMA... sigh. Needs sorting out.
    if (bRestartCharInput)                              // may be out of date, but...
        Allowi(pdx, true);                              // ...Allowi tests a lock too.
    dev_dbg(&pdx->interface->dev, "%s done", __func__);
}

/****************************************************************************
** StageChunk
**
** Generates the next chunk of data making up a staged transfer.
**
** The calling code must have acquired the staging spinlock before calling
**  this function, and is responsible for releasing it. We are at callback level.
****************************************************************************/
static int StageChunk(DEVICE_EXTENSION *pdx)
{
    int iReturn = U14ERR_NOERROR;
	unsigned int ChunkSize;
    int nPipe = pdx->StagedRead ? 3 : 2;                // The pipe number to use for reads or writes
    if (pdx->nPipes == 3) nPipe--;                      // Adjust for the 3-pipe case
    if (nPipe < 0)                                      // and trap case that should never happen
        return U14ERR_FAIL;

    if (!CanAcceptIoRequests(pdx))                      // got sudden remove?
    {
		dev_info(&pdx->interface->dev, "%s sudden remove, giving up", __func__);
        return U14ERR_FAIL;                                // could do with a better error
    }

    ChunkSize = (pdx->StagedLength - pdx->StagedDone);  // transfer length remaining
    if (ChunkSize > STAGED_SZ)                          // make sure to keep legal
		ChunkSize = STAGED_SZ;                          //  limit to max allowed

    if (!pdx->StagedRead)                               // if writing...
        CopyUserSpace(pdx, ChunkSize);                  // ...copy data into the buffer

    usb_fill_bulk_urb(pdx->pStagedUrb, pdx->udev,
                      pdx->StagedRead ? usb_rcvbulkpipe(pdx->udev, pdx->epAddr[nPipe]):
                                        usb_sndbulkpipe(pdx->udev, pdx->epAddr[nPipe]),
                      pdx->pCoherStagedIO, ChunkSize, staged_callback, pdx);
    pdx->pStagedUrb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
    usb_anchor_urb(pdx->pStagedUrb, &pdx->submitted);   // in case we need to kill it
    iReturn = usb_submit_urb(pdx->pStagedUrb, GFP_ATOMIC);
    if (iReturn)
    {
        usb_unanchor_urb(pdx->pStagedUrb);              // kill it
        pdx->bPipeError[nPipe] = 1;                     // Flag an error to be handled later
        dev_err(&pdx->interface->dev, "%s submit urb failed, code %d", __func__, iReturn);
    }
    else
        pdx->bStagedUrbPending = true;                  // Set the flag for staged URB pending
    dev_dbg(&pdx->interface->dev, "%s done so far:%d, this size:%d", __func__, pdx->StagedDone, ChunkSize);

    return iReturn;
}

/***************************************************************************
** ReadWriteMem
**
** This routine is used generally for block read and write operations.
** Breaks up a read or write in to specified sized chunks, as specified by pipe
** information on maximum transfer size.
**
** Any code that calls this must be holding the stagedLock
**
** Arguments:
**    DeviceObject - pointer to our FDO (Functional Device Object)
**    Read - TRUE for read, FALSE for write. This is from POV of the driver
**    wIdent - the transfer area number - defines memory area and more.
**    dwOffs - the start offset within the transfer area of the start of this
**             transfer.
**    dwLen - the number of bytes to transfer.
*/
int ReadWriteMem(DEVICE_EXTENSION *pdx, bool Read, unsigned short wIdent,
                      unsigned int dwOffs, unsigned int dwLen)
{
    TRANSAREA* pArea = &pdx->rTransDef[wIdent];     // Transfer area info

    if (!CanAcceptIoRequests(pdx))         // Are we in a state to accept new requests?
    {
		dev_err(&pdx->interface->dev, "%s can't accept requests", __func__);
        return U14ERR_FAIL;
    }

    dev_dbg(&pdx->interface->dev, "%s xfer %d bytes to %s, offset %d, area %d",
            __func__, dwLen, Read ? "host" : "1401", dwOffs, wIdent);

    // Amazingly, we can get an escape sequence back before the current staged Urb is done, so we
    //  have to check for this situation and, if so, wait until all is OK.
    if (pdx->bStagedUrbPending)
    {
        pdx->bXFerWaiting = true;                   // Flag we are waiting
  		dev_info(&pdx->interface->dev, "%s xfer is waiting, as previous staged pending", __func__);
        return U14ERR_NOERROR;
    }

    if (dwLen == 0)                 		        // allow 0-len read or write; just return success
    {
		dev_dbg(&pdx->interface->dev, "%s OK; zero-len read/write request", __func__);
        return U14ERR_NOERROR;
    }

    if ((pArea->bCircular) &&                       // Circular transfer?
        (pArea->bCircToHost) && (Read))             // In a supported direction
    {                                               // If so, we sort out offset ourself
        bool bWait = false;                         // Flag for transfer having to wait

	    dev_dbg(&pdx->interface->dev, "Circular buffers are %d at %d and %d at %d",
              pArea->aBlocks[0].dwSize, pArea->aBlocks[0].dwOffset, pArea->aBlocks[1].dwSize, pArea->aBlocks[1].dwOffset);
        if (pArea->aBlocks[1].dwSize > 0)           // Using the second block already?
        {
            dwOffs = pArea->aBlocks[1].dwOffset + pArea->aBlocks[1].dwSize; // take offset from that
            bWait = (dwOffs + dwLen) > pArea->aBlocks[0].dwOffset;  // Wait if will overwrite block 0?
            bWait |= (dwOffs + dwLen) > pArea->dwLength;            // or if it overflows the buffer
        }
        else                                        // Area 1 not in use, try to use area 0
        {
            if (pArea->aBlocks[0].dwSize == 0)      // Reset block 0 if not in use
                pArea->aBlocks[0].dwOffset = 0;
            dwOffs = pArea->aBlocks[0].dwOffset + pArea->aBlocks[0].dwSize;
            if ((dwOffs+dwLen) > pArea->dwLength)   // Off the end of the buffer?
            {
                pArea->aBlocks[1].dwOffset = 0;     // Set up to use second block
                dwOffs = 0;
                bWait = (dwOffs + dwLen) > pArea->aBlocks[0].dwOffset;    // Wait if will overwrite block 0?
                bWait |= (dwOffs + dwLen) > pArea->dwLength;            // or if it overflows the buffer
            }
        }

        if (bWait)                                  // This transfer will have to wait?
        {
            pdx->bXFerWaiting = true;               // Flag we are waiting
    		dev_dbg(&pdx->interface->dev, "%s xfer waiting for circular buffer space", __func__);
            return U14ERR_NOERROR;
        }

  		dev_dbg(&pdx->interface->dev, "%s circular xfer, %d bytes starting at %d", __func__, dwLen, dwOffs);
    }

    // Save the parameters for the read\write transfer
    pdx->StagedRead = Read;                         // Save the parameters for this read
    pdx->StagedId = wIdent;                         // ID allows us to get transfer area info
    pdx->StagedOffset = dwOffs;                     // The area within the transfer area
    pdx->StagedLength = dwLen;
    pdx->StagedDone = 0;                            // Initialise the byte count
    pdx->dwDMAFlag = MODE_LINEAR;                   // Set DMA mode flag at this point
    pdx->bXFerWaiting = false;                      // Clearly not a transfer waiting now

//    KeClearEvent(&pdx->StagingDoneEvent);           // Clear the transfer done event
    StageChunk(pdx);                                // fire off the first chunk

    return U14ERR_NOERROR;
}

/****************************************************************************
**
** ReadChar
**
** Reads a character a buffer. If there is no more
**  data we return FALSE. Used as part of decoding a DMA request.
**
****************************************************************************/
static bool ReadChar(unsigned char* pChar, char* pBuf, unsigned int* pdDone, unsigned int dGot)
{
    bool bRead = false;
    unsigned int dDone = *pdDone;

    if (dDone < dGot)                       // If there is more data
    {
        *pChar = (unsigned char)pBuf[dDone];// Extract the next char
        dDone++;                            // Increment the done count
        *pdDone = dDone;
        bRead = true;                       // and flag success
    }

    return bRead;
}

#ifdef NOTUSED
/****************************************************************************
**
** ReadWord
**
** Reads a word from the 1401, just uses ReadChar twice; passes on any error
**
*****************************************************************************/
static bool ReadWord(unsigned short* pWord, char* pBuf, unsigned int* pdDone, unsigned int dGot)
{
    if (ReadChar((unsigned char*)pWord, pBuf, pdDone, dGot))
        return ReadChar(((unsigned char*)pWord)+1, pBuf, pdDone, dGot);
    else
        return false;
}
#endif

/****************************************************************************
** ReadHuff
**
** Reads a coded number in and returns it, Code is:
** If data is in range 0..127 we recieve 1 byte. If data in range 128-16383
** we recieve two bytes, top bit of first indicates another on its way. If
** data in range 16383-4194303 we get three bytes, top two bits of first set
** to indicate three byte total.
**
*****************************************************************************/
static bool ReadHuff(volatile unsigned int* pDWord, char* pBuf, unsigned int* pdDone, unsigned int dGot)
{
    unsigned char ucData;                /* for each read to ReadChar */
    bool bReturn = true;                 /* assume we will succeed */
    unsigned int dwData = 0;             /* Accumulator for the data */

    if (ReadChar(&ucData, pBuf, pdDone, dGot))
    {
        dwData = ucData;                        /* copy the data */
        if ((dwData & 0x00000080) != 0)         /* Bit set for more data ? */
        {
            dwData &= 0x0000007F;               /* Clear the relevant bit */
            if (ReadChar(&ucData, pBuf, pdDone, dGot))
            {
                dwData = (dwData << 8) | ucData;
                if ((dwData & 0x00004000) != 0) /* three byte sequence ? */
                {
                    dwData &= 0x00003FFF;       /* Clear the relevant bit */
                    if (ReadChar(&ucData, pBuf, pdDone, dGot))
                        dwData = (dwData << 8) | ucData;
                    else
                        bReturn = false;
                }
            }
            else
                bReturn = false;                /* couldn't read data */
        }
    }
    else
        bReturn = false;

    *pDWord = dwData;                           /* return the data */
    return bReturn;
}

/***************************************************************************
**
** ReadDMAInfo
**
** Tries to read info about the dma request from the 1401 and decode it into
** the dma descriptor block. We have at this point had the escape character
** from the 1401 and now we must read in the rest of the information about
** the transfer request. Returns FALSE if 1401 fails to respond or obselete
** code from 1401 or bad parameters.
**
** The pBuf char pointer does not include the initial escape character, so
**  we start handling the data at offset zero.
**
*****************************************************************************/
static bool ReadDMAInfo(volatile DMADESC* pDmaDesc, DEVICE_EXTENSION *pdx,
                           char* pBuf, unsigned int dwCount)
{
    bool bResult = false;       // assume we won't succeed
    unsigned char ucData;
    unsigned int dDone = 0;     // We haven't parsed anything so far

    dev_dbg(&pdx->interface->dev, "%s", __func__);

    if (ReadChar(&ucData, pBuf, &dDone, dwCount))
    {
        unsigned char ucTransCode = (ucData & 0x0F);    // get code for transfer type
        unsigned short wIdent = ((ucData >> 4) & 0x07); // and area identifier

        // fill in the structure we were given
        pDmaDesc->wTransType = ucTransCode; // type of transfer
        pDmaDesc->wIdent = wIdent;          // area to use
        pDmaDesc->dwSize = 0;               // initialise other bits
        pDmaDesc->dwOffset = 0;

        dev_dbg(&pdx->interface->dev, "%s type: %d ident: %d", __func__, pDmaDesc->wTransType, pDmaDesc->wIdent);

        pDmaDesc->bOutWard = (ucTransCode != TM_EXTTOHOST); // set transfer direction

        switch (ucTransCode)
        {
            case TM_EXTTOHOST:              // Extended linear transfer modes (the only ones!)
            case TM_EXTTO1401:
            {
                bResult = ReadHuff(&(pDmaDesc->dwOffset), pBuf, &dDone, dwCount) &&
                          ReadHuff(&(pDmaDesc->dwSize), pBuf, &dDone, dwCount);
                if (bResult)
                {
                    dev_dbg(&pdx->interface->dev, "%s xfer offset & size %d %d",
                            __func__, pDmaDesc->dwOffset, pDmaDesc->dwSize);

                    if ((wIdent >= MAX_TRANSAREAS) ||       // Illegal area number, or...
                        (!pdx->rTransDef[wIdent].bUsed) ||  // area not set up, or...
                        (pDmaDesc->dwOffset > pdx->rTransDef[wIdent].dwLength) || // range/size
                        ((pDmaDesc->dwOffset + pDmaDesc->dwSize) > (pdx->rTransDef[wIdent].dwLength)))
                    {
                        bResult = false;                    // bad parameter(s)
                        dev_dbg(&pdx->interface->dev, "%s bad param - id %d, bUsed %d, offset %d, size %d, area length %d",
                                 __func__, wIdent, pdx->rTransDef[wIdent].bUsed, pDmaDesc->dwOffset, pDmaDesc->dwSize,
                                  pdx->rTransDef[wIdent].dwLength);
                    }
                }
                break;
            }
            default:
                break;
        }
    }
    else
        bResult = false;

    if (!bResult)                            // now check parameters for validity
        dev_err(&pdx->interface->dev, "%s error reading Esc sequence", __func__);

    return bResult;
}

/****************************************************************************
**
** Handle1401Esc
**
** Deals with an escape sequence coming from the 1401. This can either be
**  a DMA transfer request of various types or a response to an escape sequence
**  sent to the 1401. This is called from a callback.
**
** Parameters are
**
** dwCount - the number of characters in the device extension char in buffer,
**           this is known to be at least 2 or we will not be called.
**
****************************************************************************/
static int Handle1401Esc(DEVICE_EXTENSION* pdx, char* pCh, unsigned int dwCount)
{
    int iReturn = U14ERR_FAIL;

    // I have no idea what this next test is about. '?' is 0x3f, which is area 3, code
    // 15. At the moment, this is not used, so it does no harm, but unless someone can
    // tell me what this is for, it should be removed from this and the Windows driver.
    if (pCh[0] == '?')                              // Is this an information response
    {                                               // Parse and save the information
    }
    else
    {
        spin_lock(&pdx->stagedLock);                // Lock others out

        if (ReadDMAInfo(&pdx->rDMAInfo, pdx, pCh, dwCount))    // Get DMA parameters
        {
            unsigned short wTransType = pdx->rDMAInfo.wTransType;    // check transfer type

            dev_dbg(&pdx->interface->dev, "%s xfer to %s, offset %d, length %d", __func__,
                    pdx->rDMAInfo.bOutWard ? "1401" : "host",
                    pdx->rDMAInfo.dwOffset, pdx->rDMAInfo.dwSize);

            if (pdx->bXFerWaiting)                  // Check here for badly out of kilter...
            {                                       // This can never happen, really
                dev_err(&pdx->interface->dev, "ERROR: DMA setup while transfer still waiting");
                spin_unlock(&pdx->stagedLock);
            }
            else
            {
                if ((wTransType == TM_EXTTOHOST) || (wTransType == TM_EXTTO1401))
                {
                    iReturn = ReadWriteMem(pdx, !pdx->rDMAInfo.bOutWard, pdx->rDMAInfo.wIdent, pdx->rDMAInfo.dwOffset, pdx->rDMAInfo.dwSize);
                    if (iReturn != U14ERR_NOERROR)
                        dev_err(&pdx->interface->dev, "%s ReadWriteMem() failed %d", __func__, iReturn);
                }
                else                                    // This covers non-linear transfer setup
                    dev_err(&pdx->interface->dev, "%s Unknown block xfer type %d", __func__, wTransType);
            }
        }
        else                                        // Failed to read parameters
            dev_err(&pdx->interface->dev, "%s ReadDMAInfo() fail", __func__);

        spin_unlock(&pdx->stagedLock);   // OK here
    }

    dev_dbg(&pdx->interface->dev, "%s returns %d", __func__, iReturn);

    return iReturn;
}

/****************************************************************************
** Callback for the character read complete or error
****************************************************************************/
static void ced_readchar_callback(struct urb* pUrb)
{
    DEVICE_EXTENSION *pdx = pUrb->context;
    int nGot = pUrb->actual_length;             // what we transferred

    if (pUrb->status)                           // Do we have a problem to handle?
    {
        int nPipe = pdx->nPipes == 4 ? 1 : 0;   // The pipe number to use for error
        // sync/async unlink faults aren't errors... just saying device removed or stopped
        if (!(pUrb->status == -ENOENT || pUrb->status == -ECONNRESET || pUrb->status == -ESHUTDOWN))
        {
            dev_err(&pdx->interface->dev, "%s - nonzero write bulk status received: %d", __func__, pUrb->status);
        }
        else
            dev_dbg(&pdx->interface->dev, "%s - 0 chars pUrb->status=%d (shutdown?)", __func__, pUrb->status);

        spin_lock(&pdx->err_lock);
        pdx->errors = pUrb->status;
        spin_unlock(&pdx->err_lock);
        nGot = 0;                               //  and tidy up again if so

        spin_lock(&pdx->charInLock);            // already at irq level
        pdx->bPipeError[nPipe] = 1;             // Flag an error for later
    }
    else
    {
        if ((nGot > 1) && ((pdx->pCoherCharIn[0] & 0x7f) == 0x1b))  // Esc sequence?
        {
            Handle1401Esc(pdx, &pdx->pCoherCharIn[1], nGot-1);      // handle it
            spin_lock(&pdx->charInLock);            // already at irq level
        }
        else
        {
            spin_lock(&pdx->charInLock);            // already at irq level
            if (nGot > 0)
            {
                unsigned int i;
                if (nGot < INBUF_SZ)
                {
                    pdx->pCoherCharIn[nGot] = 0;    // tidy the string
                    dev_dbg(&pdx->interface->dev, "%s got %d chars >%s<", __func__, nGot, pdx->pCoherCharIn);
                }

                // We know that whatever we read must fit in the input buffer
                for (i = 0; i < nGot; i++)
                {
                    pdx->inputBuffer[pdx->dwInBuffPut++] = pdx->pCoherCharIn[i] & 0x7F;
                    if (pdx->dwInBuffPut >= INBUF_SZ)
                        pdx->dwInBuffPut = 0;
                }

                if ((pdx->dwNumInput + nGot) <= INBUF_SZ)
                    pdx->dwNumInput += nGot;            // Adjust the buffer count accordingly
            }
            else
                dev_dbg(&pdx->interface->dev, "%s read ZLP", __func__);
        }
    }

    pdx->bReadCharsPending = false;         // No longer have a pending read
    spin_unlock(&pdx->charInLock);          // already at irq level

    Allowi(pdx, true);                      // see if we can do the next one
}

/****************************************************************************
** Allowi
**
** This is used to make sure that there is always a pending input transfer so
** we can pick up any inward transfers. This can be called in multiple contexts
** so we use the irqsave version of the spinlock.
****************************************************************************/
int Allowi(DEVICE_EXTENSION* pdx, bool bInCallback)
{
    int iReturn = U14ERR_NOERROR;
    unsigned long flags;
    spin_lock_irqsave(&pdx->charInLock, flags);     // can be called in multiple contexts

    // We don't want char input running while DMA is in progress as we know that this
    //  can cause sequencing problems for the 2270. So don't. It will also allow the
    //  ERR response to get back to the host code too early on some PCs, even if there
    //  is no actual driver failure, so we don't allow this at all.
    if (!pdx->bInDrawDown &&                        // stop input if
        !pdx->bReadCharsPending &&                  // If no read request outstanding
        (pdx->dwNumInput < (INBUF_SZ/2)) &&         //  and there is some space
        (pdx->dwDMAFlag == MODE_CHAR) &&            //  not doing any DMA
        (!pdx->bXFerWaiting) &&                     //  no xfer waiting to start
        (CanAcceptIoRequests(pdx)))                 //  and activity is generally OK
    {                                               //  then off we go
        unsigned int nMax = INBUF_SZ-pdx->dwNumInput; // max we could read
        int nPipe = pdx->nPipes == 4 ? 1 : 0;       // The pipe number to use

        dev_dbg(&pdx->interface->dev, "%s %d chars in input buffer", __func__, pdx->dwNumInput);

        usb_fill_int_urb(pdx->pUrbCharIn, pdx->udev,
                         usb_rcvintpipe(pdx->udev, pdx->epAddr[nPipe]),
                         pdx->pCoherCharIn, nMax, ced_readchar_callback,
                         pdx, pdx->bInterval);
        pdx->pUrbCharIn->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; // short xfers are OK by default
        usb_anchor_urb(pdx->pUrbCharIn, &pdx->submitted);   // in case we need to kill it
        iReturn = usb_submit_urb(pdx->pUrbCharIn, bInCallback ? GFP_ATOMIC : GFP_KERNEL);
        if (iReturn)
        {
            usb_unanchor_urb(pdx->pUrbCharIn);  // remove from list of active Urbs
            pdx->bPipeError[nPipe] = 1;         // Flag an error to be handled later
            dev_err(&pdx->interface->dev,"%s submit urb failed: %d", __func__, iReturn);
        }
        else
            pdx->bReadCharsPending = true;      // Flag that we are active here
    }

    spin_unlock_irqrestore(&pdx->charInLock, flags);

    return iReturn;

}

/*****************************************************************************
** The ioctl entry point to the driver that is used by us to talk to it.
** inode    The device node (no longer in 3.0.0 kernels)
** file     The file that is open, which holds our pdx pointer
** ulArg    The argument passed in. Note that long is 64-bits in 64-bit system, i.e. it is big
**          enough for a 64-bit pointer.
*****************************************************************************/
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
static int ced_ioctl(struct file * file, unsigned int cmd, unsigned long ulArg)
#else
static int ced_ioctl(struct inode * node, struct file * file, unsigned int cmd, unsigned long ulArg)
#endif
{
    int err = 0;
    DEVICE_EXTENSION *pdx = file->private_data;
    if (!CanAcceptIoRequests(pdx))          // check we still exist
        return -ENODEV;

    // Check that access is allowed, where is is needed. Anything that would have an indeterminate
    // size will be checked by the specific command.
    if (_IOC_DIR(cmd) & _IOC_READ)          // read from point of view of user...
        err = !access_ok(VERIFY_WRITE, (void __user *)ulArg, _IOC_SIZE(cmd)); // is kernel write
    else if (_IOC_DIR(cmd) & _IOC_WRITE)    // and write from point of view of user...
        err = !access_ok(VERIFY_READ, (void __user *)ulArg, _IOC_SIZE(cmd)); // is kernel read
    if (err)
        return -EFAULT;

    switch (_IOC_NR(cmd))
    {
    case _IOC_NR(IOCTL_CED_SENDSTRING(0)):
        return SendString(pdx, (const char __user*)ulArg, _IOC_SIZE(cmd));

    case _IOC_NR(IOCTL_CED_RESET1401):
        return Reset1401(pdx);

    case _IOC_NR(IOCTL_CED_GETCHAR):
        return GetChar(pdx);

    case _IOC_NR(IOCTL_CED_SENDCHAR):
        return SendChar(pdx, (char)ulArg);

    case _IOC_NR(IOCTL_CED_STAT1401):
        return Stat1401(pdx);

    case _IOC_NR(IOCTL_CED_LINECOUNT):
        return LineCount(pdx);

    case _IOC_NR(IOCTL_CED_GETSTRING(0)):
        return GetString(pdx, (char __user*)ulArg, _IOC_SIZE(cmd));

    case _IOC_NR(IOCTL_CED_SETTRANSFER):
        return SetTransfer(pdx, (TRANSFERDESC __user*)ulArg);

    case _IOC_NR(IOCTL_CED_UNSETTRANSFER):
        return UnsetTransfer(pdx, (int)ulArg);

    case _IOC_NR(IOCTL_CED_SETEVENT):
        return SetEvent(pdx, (TRANSFEREVENT __user*)ulArg);

    case _IOC_NR(IOCTL_CED_GETOUTBUFSPACE):
        return GetOutBufSpace(pdx);

    case _IOC_NR(IOCTL_CED_GETBASEADDRESS):
        return -1;

    case _IOC_NR(IOCTL_CED_GETDRIVERREVISION):
        return (2<<24)|(DRIVERMAJREV<<16) | DRIVERMINREV;   // USB | MAJOR | MINOR

    case _IOC_NR(IOCTL_CED_GETTRANSFER):
        return GetTransfer(pdx, (TGET_TX_BLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_KILLIO1401):
        return KillIO1401(pdx);

    case _IOC_NR(IOCTL_CED_STATEOF1401):
        return StateOf1401(pdx);

    case _IOC_NR(IOCTL_CED_GRAB1401):
    case _IOC_NR(IOCTL_CED_FREE1401):
        return U14ERR_NOERROR;

    case _IOC_NR(IOCTL_CED_STARTSELFTEST):
        return StartSelfTest(pdx);

    case _IOC_NR(IOCTL_CED_CHECKSELFTEST):
        return CheckSelfTest(pdx, (TGET_SELFTEST __user*)ulArg);

    case _IOC_NR(IOCTL_CED_TYPEOF1401):
        return TypeOf1401(pdx);

    case _IOC_NR(IOCTL_CED_TRANSFERFLAGS):
        return TransferFlags(pdx);

    case _IOC_NR(IOCTL_CED_DBGPEEK):
        return DbgPeek(pdx, (TDBGBLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_DBGPOKE):
        return DbgPoke(pdx, (TDBGBLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_DBGRAMPDATA):
        return DbgRampData(pdx, (TDBGBLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_DBGRAMPADDR):
        return DbgRampAddr(pdx, (TDBGBLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_DBGGETDATA):
        return DbgGetData(pdx, (TDBGBLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_DBGSTOPLOOP):
        return DbgStopLoop(pdx);

    case _IOC_NR(IOCTL_CED_FULLRESET):
          pdx->bForceReset = true;              // Set a flag for a full reset
          break;

    case _IOC_NR(IOCTL_CED_SETCIRCULAR):
        return SetCircular(pdx, (TRANSFERDESC __user*)ulArg);

    case _IOC_NR(IOCTL_CED_GETCIRCBLOCK):
        return GetCircBlock(pdx, (TCIRCBLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_FREECIRCBLOCK):
        return FreeCircBlock(pdx, (TCIRCBLOCK __user*)ulArg);

    case _IOC_NR(IOCTL_CED_WAITEVENT):
        return WaitEvent(pdx, (int)(ulArg & 0xff), (int)(ulArg >> 8));

    case _IOC_NR(IOCTL_CED_TESTEVENT):
        return TestEvent(pdx, (int)ulArg);

    default:
        return U14ERR_NO_SUCH_FN;
    }
    return U14ERR_NOERROR;
}

static const struct file_operations ced_fops =
{
    .owner =	THIS_MODULE,
    .read =		ced_read,
    .write =	ced_write,
    .open =		ced_open,
    .release =	ced_release,
    .flush =	ced_flush,
    .llseek =	noop_llseek,
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,36)
    .unlocked_ioctl =    ced_ioctl,
#else
    .ioctl =    ced_ioctl,
#endif
};

/*
 * usb class driver info in order to get a minor number from the usb core,
 * and to have the device registered with the driver core
 */
static struct usb_class_driver ced_class =
{
    .name =		"cedusb%d",
    .fops =		&ced_fops,
    .minor_base =	USB_CED_MINOR_BASE,
};

// Check that the device that matches a 1401 vendor and product ID is OK to use and
// initialise our DEVICE_EXTENSION.
static int ced_probe(struct usb_interface *interface, const struct usb_device_id *id)
{
    DEVICE_EXTENSION *pdx;
    struct usb_host_interface *iface_desc;
    struct usb_endpoint_descriptor *endpoint;
    int i, bcdDevice;
    int retval = -ENOMEM;

    // allocate memory for our device extension and initialize it
    pdx = kzalloc(sizeof(*pdx), GFP_KERNEL);
    if (!pdx)
    {
        err("Out of memory");
        goto error;
    }

    for (i=0; i<MAX_TRANSAREAS; ++i)      // Initialise the wait queues
    {
        init_waitqueue_head(&pdx->rTransDef[i].wqEvent);
    }

    // Put initialises for our stuff here. Note that all of *pdx is zero, so
    // no need to explicitly zero it.
    spin_lock_init(&pdx->charOutLock);
    spin_lock_init(&pdx->charInLock);
    spin_lock_init(&pdx->stagedLock);

    // Initialises from the skeleton stuff
    kref_init(&pdx->kref);
    mutex_init(&pdx->io_mutex);
    spin_lock_init(&pdx->err_lock);
    init_usb_anchor(&pdx->submitted);

    pdx->udev = usb_get_dev(interface_to_usbdev(interface));
    pdx->interface = interface;

    // Attempt to identify the device
    bcdDevice = pdx->udev->descriptor.bcdDevice;
    i = (bcdDevice >> 8);
    if (i == 0)
        pdx->s1401Type = TYPEU1401;
    else if ((i>=1) && (i<=23))
        pdx->s1401Type = i+2;
    else
    {
        dev_err(&interface->dev, "%s Unknown device. bcdDevice = %d", __func__, bcdDevice);
        goto error;
    }
    // set up the endpoint information. We only care about the number of EP as
    // we know that we are dealing with a 1401 device.
    iface_desc = interface->cur_altsetting;
    pdx->nPipes = iface_desc->desc.bNumEndpoints;
    dev_info(&interface->dev, "1401Type=%d with %d End Points", pdx->s1401Type, pdx->nPipes);
    if ((pdx->nPipes < 3) || (pdx->nPipes > 4))
        goto error;

    // Allocate the URBs we hold for performing transfers
    pdx->pUrbCharOut = usb_alloc_urb(0, GFP_KERNEL);    // character output URB
    pdx->pUrbCharIn = usb_alloc_urb(0, GFP_KERNEL);     // character input URB
    pdx->pStagedUrb = usb_alloc_urb(0, GFP_KERNEL);     // block transfer URB
    if (!pdx->pUrbCharOut || !pdx->pUrbCharIn || !pdx->pStagedUrb)
    {
        dev_err(&interface->dev, "%s URB alloc failed", __func__);
        goto error;
    }

    pdx->pCoherStagedIO = usb_alloc_coherent(pdx->udev, STAGED_SZ, GFP_KERNEL, &pdx->pStagedUrb->transfer_dma);
    pdx->pCoherCharOut = usb_alloc_coherent(pdx->udev, OUTBUF_SZ, GFP_KERNEL, &pdx->pUrbCharOut->transfer_dma);
    pdx->pCoherCharIn = usb_alloc_coherent(pdx->udev, INBUF_SZ, GFP_KERNEL, &pdx->pUrbCharIn->transfer_dma);
    if (!pdx->pCoherCharOut || !pdx->pCoherCharIn || !pdx->pCoherStagedIO)
    {
        dev_err(&interface->dev, "%s Coherent buffer alloc failed", __func__);
        goto error;
    }

    for (i = 0; i < pdx->nPipes; ++i)
    {
        endpoint = &iface_desc->endpoint[i].desc;
        pdx->epAddr[i] = endpoint->bEndpointAddress;
        dev_info(&interface->dev, "Pipe %d, ep address %02x", i, pdx->epAddr[i]);
        if (((pdx->nPipes==3) && (i==0)) || // if char input end point
            ((pdx->nPipes==4) && (i==1)))
        {
            pdx->bInterval = endpoint->bInterval;   // save the endpoint interrupt interval
            dev_info(&interface->dev, "Pipe %d, bInterval = %d", i, pdx->bInterval);
        }

        // Detect USB2 by checking last ep size (64 if USB1)
        if (i == pdx->nPipes-1)     // if this is the last ep (bulk)
        {
            pdx->bIsUSB2 = le16_to_cpu(endpoint->wMaxPacketSize) > 64;
            dev_info(&pdx->interface->dev, "USB%d", pdx->bIsUSB2 + 1);
        }
    }

    /* save our data pointer in this interface device */
    usb_set_intfdata(interface, pdx);

    /* we can register the device now, as it is ready */
    retval = usb_register_dev(interface, &ced_class);
    if (retval)
    {
        /* something prevented us from registering this driver */
        err("Not able to get a minor for this device.");
        usb_set_intfdata(interface, NULL);
        goto error;
    }

    /* let the user know what node this device is now attached to */
    dev_info(&interface->dev,
             "USB CEDUSB device now attached to cedusb #%d",
             interface->minor);
    return 0;

error:
    if (pdx)
        kref_put(&pdx->kref, ced_delete);   // frees allocated memory
    return retval;
}

static void ced_disconnect(struct usb_interface *interface)
{
    DEVICE_EXTENSION *pdx = usb_get_intfdata(interface);
    int minor = interface->minor;               // save for message at the end
    int i;

    usb_set_intfdata(interface, NULL);          // remove the pdx from the interface
    usb_deregister_dev(interface, &ced_class);  // give back our minor device number

    mutex_lock(&pdx->io_mutex);                 // stop more I/O starting while...
    ced_draw_down(pdx);                         // ...wait for then kill any io
    for (i=0; i<MAX_TRANSAREAS; ++i)
    {
        int iErr = ClearArea(pdx, i);           // ...release any used memory
        if (iErr == U14ERR_UNLOCKFAIL)
            dev_err(&pdx->interface->dev, "%s Area %d was in used", __func__, i);
    }
    pdx->interface = NULL;                      // ...we kill off link to interface
    mutex_unlock(&pdx->io_mutex);

    usb_kill_anchored_urbs(&pdx->submitted);

    kref_put(&pdx->kref, ced_delete);           // decrement our usage count

    dev_info(&interface->dev, "USB cedusb #%d now disconnected", minor);
}

// Wait for all the urbs we know of to be done with, then kill off any that
// are left. NBNB we will need to have a mechanism to stop circular xfers
// from trying to fire off more urbs. We will wait up to 3 seconds for Urbs
// to be done.
void ced_draw_down(DEVICE_EXTENSION *pdx)
{
    int time;
    dev_dbg(&pdx->interface->dev,"%s called", __func__);

    pdx->bInDrawDown = true;
    time = usb_wait_anchor_empty_timeout(&pdx->submitted, 3000);
    if (!time)              // if we timed out we kill the urbs
    {
        usb_kill_anchored_urbs(&pdx->submitted);
        dev_err(&pdx->interface->dev,"%s timed out", __func__);
    }
    pdx->bInDrawDown = false;
 }

static int ced_suspend(struct usb_interface *intf, pm_message_t message)
{
    DEVICE_EXTENSION *pdx = usb_get_intfdata(intf);
    if (!pdx)
        return 0;
    ced_draw_down(pdx);

    dev_dbg(&pdx->interface->dev,"%s called", __func__);
    return 0;
}

static int ced_resume(struct usb_interface *intf)
{
    DEVICE_EXTENSION *pdx = usb_get_intfdata(intf);
    if (!pdx)
        return 0;
    dev_dbg(&pdx->interface->dev,"%s called", __func__);
    return 0;
}

static int ced_pre_reset(struct usb_interface *intf)
{
    DEVICE_EXTENSION *pdx = usb_get_intfdata(intf);
    dev_dbg(&pdx->interface->dev, "%s", __func__);
    mutex_lock(&pdx->io_mutex);
    ced_draw_down(pdx);
    return 0;
}

static int ced_post_reset(struct usb_interface *intf)
{
    DEVICE_EXTENSION *pdx = usb_get_intfdata(intf);
    dev_dbg(&pdx->interface->dev, "%s", __func__);

    /* we are sure no URBs are active - no locking needed */
    pdx->errors = -EPIPE;
    mutex_unlock(&pdx->io_mutex);

    return 0;
}

static struct usb_driver ced_driver =
{
    .name =		    "cedusb",
    .probe =	    ced_probe,
    .disconnect =	ced_disconnect,
    .suspend =	    ced_suspend,
    .resume =	    ced_resume,
    .pre_reset =	ced_pre_reset,
    .post_reset =	ced_post_reset,
    .id_table =	    ced_table,
    .supports_autosuspend = 1,
};

static int __init usb_skel_init(void)
{
    /* register this driver with the USB subsystem */
    int result = usb_register(&ced_driver);
    if (result)
        err("usb_register failed. Error number %d", result);

    return result;
}

static void __exit usb_skel_exit(void)
{
    /* deregister this driver with the USB subsystem */
    usb_deregister(&ced_driver);
}

module_init(usb_skel_init);
module_exit(usb_skel_exit);

MODULE_LICENSE("GPL");
usb1401.h0000664000175000017500000003250211722662202010764 0ustar  greggreg/* usb1401.h
 Header file for the CED 1401 USB device driver for Linux
 Copyright (C) 2010 Cambridge Electronic Design Ltd
 Author Greg P Smith (greg@ced.co.uk)

 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
 of the License, 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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
*/
#ifndef __USB1401_H__
#define __USB1401_H__
#include "USE1401.H"
#include "ced_ioctl.h"

#ifndef UINT
#define UINT unsigned int
#endif

/// Device type codes, but these don't need to be extended - a succession is assumed
/// These are set for usb from the bcdDevice field (suitably mangled). Future devices
/// will be added in order of device creation to the list, so the names here are just
/// to help use remember which device is which. The U14ERR_... values follow the same
/// pattern for modern devices.
#define TYPEUNKNOWN        -1             // dont know
#define TYPE1401           0              // standard 1401
#define TYPEPLUS           1              // 1401 plus
#define TYPEU1401          2              // u1401
#define TYPEPOWER          3              // Power1401
#define TYPEU14012         4              // u1401 mkII
#define TYPEPOWER2         5              // Power1401 mk II
#define TYPEMICRO3         6              // Micro1401-3
#define TYPEPOWER3         7              // Power1401-3

/// Some useful defines of constants. DONT FORGET to change the version in the
/// resources whenever you change it here!.
#define DRIVERMAJREV      2             // driver revision level major (match windows)
#define DRIVERMINREV      0             // driver revision level minor

/// Definitions of the various block transfer command codes
#define TM_EXTTOHOST    8               // extended tohost
#define TM_EXTTO1401    9               // extended to1401

/// Definitions of values in usbReqtype. Used in sorting out setup actions
#define H_TO_D 0x00
#define D_TO_H 0x80
#define VENDOR 0x40
#define DEVREQ 0x00
#define INTREQ 0x01
#define ENDREQ 0x02

/// Definition of values in usbRequest, again used to sort out setup
#define GET_STATUS      0x00
#define CLEAR_FEATURE   0x01
#define SET_FEATURE     0x03
#define SET_ADDRESS     0x05
#define GET_DESC        0x06
#define SET_DESC        0x07
#define GET_CONF        0x08
#define SET_CONF        0x09
#define GET_INTERFACE   0x0a
#define SET_INTERFACE   0x0b
#define SYNCH_FRAME     0x0c

/// Definitions of the various debug command codes understood by the 1401. These
/// are used in various vendor-specific commands to achieve the desired effect
#define DB_GRAB         0x50            /* Grab is a NOP for USB */
#define DB_FREE         0x51            /* Free is a NOP for the USB */
#define DB_SETADD       0x52            /* Set debug address (double) */
#define DB_SELFTEST     0x53            /* Start self test */
#define DB_SETMASK      0x54            /* Set enable mask (double) */
#define DB_SETDEF       0x55            /* Set default mask (double) */
#define DB_PEEK         0x56            /* Peek address, save result */
#define DB_POKE         0x57            /* Poke address with data (double) */
#define DB_RAMPD        0x58            /* Ramp data at debug address */
#define DB_RAMPA        0x59            /* Ramp address bus */
#define DB_REPEATS      0x5A            /* Set repeats for operations (double) */
#define DB_WIDTH        0x5B            /* Set width for operations (byte) */
#define DB_DATA         0x5C            /* Get 4-byte data read by PEEK */
#define DB_CHARS        0x5D            /* Send chars via EP0 control write */

#define CR_CHAR          0x0D           /* The carriage return character */
#define CR_CHAR_80       0x8d           /*  and with bit 7 set */

/// A structure holding information about a block of memory for use in circular transfers
typedef struct circBlk
{
    volatile UINT dwOffset;             /* Offset within area of block start */
    volatile UINT dwSize;               /* Size of the block, in bytes (0 = unused) */
} CIRCBLK;

/// A structure holding all of the information about a transfer area - an area of
///  memory set up for use either as a source or destination in DMA transfers.
typedef struct transarea
{
    void*       lpvBuff;                // User address of xfer area saved for completeness
    UINT        dwBaseOffset;           // offset to start of xfer area in first page
    UINT        dwLength;               // Length of xfer area, in bytes
    struct page **pPages;               // Points at array of locked down pages
    int         nPages;                 // number of pages that are locked down
    bool        bUsed;                  // Is this structure in use?
    bool        bCircular;              // Is this area for circular transfers?
    bool        bCircToHost;            // Flag for direction of circular transfer
    bool        bEventToHost;           // Set event on transfer to host?
    int         iWakeUp;                // Set 1 on event, cleared by TestEvent()
    UINT        dwEventSt;              // Defines section within xfer area for...
    UINT        dwEventSz;              // ...notification by the event SZ is 0 if unset
    CIRCBLK     aBlocks[2];             // Info on a pair of circular blocks
    wait_queue_head_t wqEvent;          // The wait queue for events in this area MUST BE LAST
} TRANSAREA;

/// The DMADESC structure is used to hold information on the transfer in progress. It
/// is set up by ReadDMAInfo, using information sent by the 1401 in an escape sequence.
typedef struct dmadesc
{
    unsigned short wTransType;          /* transfer type as TM_xxx above        */
    unsigned short wIdent;              /* identifier word                      */
    unsigned int   dwSize;              /* bytes to transfer                    */
    unsigned int   dwOffset;            /* offset into transfer area for trans  */
    bool           bOutWard;            /* true when data is going TO 1401      */
} DMADESC;

#define INBUF_SZ         256            /* input buffer size */
#define OUTBUF_SZ        256            /* output buffer size */
#define STAGED_SZ 0x10000               // size of coherent buffer for staged transfers

/// Structure to hold all of our device specific stuff. We are making this as similar as we
/// can to the Windows driver to help in our understanding of what is going on.
typedef struct _DEVICE_EXTENSION
{
    char inputBuffer[INBUF_SZ];         /* The two buffers */
    char outputBuffer[OUTBUF_SZ];       /* accessed by the host functions */
    volatile unsigned int dwNumInput;   /* num of chars in input buffer   */
    volatile unsigned int dwInBuffGet;  /* where to get from input buffer */
    volatile unsigned int dwInBuffPut;  /* where to put into input buffer */
    volatile unsigned int dwNumOutput;  /* num of chars in output buffer  */
    volatile unsigned int dwOutBuffGet; /* where to get from output buffer*/
    volatile unsigned int dwOutBuffPut; /* where to put into output buffer*/

    volatile bool bSendCharsPending;    /* Flag to indicate sendchar active */
    volatile bool bReadCharsPending;    /* Flag to indicate a read is primed */
    char* pCoherCharOut;                /* special aligned buffer for chars to 1401 */
    struct urb* pUrbCharOut;            /* urb used for chars to 1401 */
    char* pCoherCharIn;                 /* special aligned buffer for chars to host */
    struct urb* pUrbCharIn;             /* urb used for chars to host */

    spinlock_t charOutLock;             /* to protect the outputBuffer and outputting */
    spinlock_t charInLock;              /* to protect the inputBuffer and char reads */
    __u8 bInterval;                     /* Interrupt end point interval */

    volatile unsigned int dwDMAFlag;    /* state of DMA */
    TRANSAREA rTransDef[MAX_TRANSAREAS];/* transfer area info */
    volatile DMADESC rDMAInfo;          // info on current DMA transfer
    volatile bool bXFerWaiting;         // Flag set if DMA transfer stalled
    volatile bool bInDrawDown;          // Flag that we want to halt transfers

    // Parameters relating to a block read\write that is in progress. Some of these values
    //  are equivalent to values in rDMAInfo. The values here are those in use, while those
    //  in rDMAInfo are those recieved from the 1401 via an escape sequence. If another
    //  escape sequence arrives before the previous xfer ends, rDMAInfo values are updated while these
    //  are used to finish off the current transfer.
    volatile short StagedId;            // The transfer area id for this transfer
    volatile bool StagedRead;           // Flag TRUE for read from 1401, FALSE for write
    volatile unsigned int StagedLength; // Total length of this transfer
    volatile unsigned int StagedOffset; // Offset within memory area for transfer start
    volatile unsigned int StagedDone;   // Bytes transferred so far
    volatile bool bStagedUrbPending;    // Flag to indicate active
    char* pCoherStagedIO;               // buffer used for block transfers
    struct urb* pStagedUrb;             // The URB to use
    spinlock_t stagedLock;              // protects ReadWriteMem() and circular buffer stuff

    short s1401Type;                    // type of 1401 attached
    short sCurrentState;                // current error state
    bool bIsUSB2;                       // type of the interface we connect to
    bool bForceReset;                   // Flag to make sure we get a real reset
    __u32 statBuf[2];                   // buffer for 1401 state info

    unsigned long ulSelfTestTime;       // used to timeout self test

    int nPipes;                         // Should be 3 or 4 depending on 1401 usb chip
    int bPipeError[4];                  // set non-zero if an error on one of the pipe
    __u8 epAddr[4];                     // addresses of the 3/4 end points

    struct usb_device *udev;            // the usb device for this device
    struct usb_interface *interface;    // the interface for this device, NULL if removed
    struct usb_anchor submitted;        // in case we need to retract our submissions
    struct mutex io_mutex;              // synchronize I/O with disconnect, one user-mode caller at a time

    int    errors;                      // the last request tanked
    int    open_count;                  // count the number of openers
    spinlock_t err_lock;                // lock for errors
    struct kref kref;
}DEVICE_EXTENSION, *PDEVICE_EXTENSION;
#define to_DEVICE_EXTENSION(d) container_of(d, DEVICE_EXTENSION, kref)

/// Definitions of routimes used between compilation object files
// in usb1401.c
extern int Allowi(DEVICE_EXTENSION* pdx, bool bInCallback);
extern int SendChars(DEVICE_EXTENSION* pdx);
extern void ced_draw_down(DEVICE_EXTENSION *pdx);
extern int ReadWriteMem(DEVICE_EXTENSION *pdx, bool Read, unsigned short wIdent,
                      unsigned int dwOffs, unsigned int dwLen);

// in ced_ioc.c
extern int ClearArea(DEVICE_EXTENSION *pdx, int nArea);
extern int SendString(DEVICE_EXTENSION* pdx, const char __user* pData, unsigned int n);
extern int SendChar(DEVICE_EXTENSION *pdx, char c);
extern int Get1401State(DEVICE_EXTENSION* pdx, __u32* state, __u32* error);
extern int ReadWrite_Cancel(DEVICE_EXTENSION *pdx);
extern bool Is1401(DEVICE_EXTENSION* pdx);
extern bool QuickCheck(DEVICE_EXTENSION* pdx, bool bTestBuff, bool bCanReset);
extern int Reset1401(DEVICE_EXTENSION *pdx);
extern int GetChar(DEVICE_EXTENSION *pdx);
extern int GetString(DEVICE_EXTENSION *pdx, char __user* pUser, int n);
extern int SetTransfer(DEVICE_EXTENSION *pdx, TRANSFERDESC __user *pTD);
extern int UnsetTransfer(DEVICE_EXTENSION *pdx, int nArea);
extern int SetEvent(DEVICE_EXTENSION *pdx, TRANSFEREVENT __user*pTE);
extern int Stat1401(DEVICE_EXTENSION *pdx);
extern int LineCount(DEVICE_EXTENSION *pdx);
extern int GetOutBufSpace(DEVICE_EXTENSION *pdx);
extern int GetTransfer(DEVICE_EXTENSION *pdx, TGET_TX_BLOCK __user *pGTB);
extern int KillIO1401(DEVICE_EXTENSION *pdx);
extern int BlkTransState(DEVICE_EXTENSION *pdx);
extern int StateOf1401(DEVICE_EXTENSION *pdx);
extern int StartSelfTest(DEVICE_EXTENSION *pdx);
extern int CheckSelfTest(DEVICE_EXTENSION *pdx, TGET_SELFTEST __user *pGST);
extern int TypeOf1401(DEVICE_EXTENSION *pdx);
extern int TransferFlags(DEVICE_EXTENSION *pdx);
extern int DbgPeek(DEVICE_EXTENSION *pdx, TDBGBLOCK __user* pDB);
extern int DbgPoke(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB);
extern int DbgRampData(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB);
extern int DbgRampAddr(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB);
extern int DbgGetData(DEVICE_EXTENSION *pdx, TDBGBLOCK __user *pDB);
extern int DbgStopLoop(DEVICE_EXTENSION *pdx);
extern int SetCircular(DEVICE_EXTENSION *pdx, TRANSFERDESC __user *pTD);
extern int GetCircBlock(DEVICE_EXTENSION *pdx, TCIRCBLOCK __user* pCB);
extern int FreeCircBlock(DEVICE_EXTENSION *pdx, TCIRCBLOCK __user* pCB);
extern int WaitEvent(DEVICE_EXTENSION *pdx, int nArea, int msTimeOut);
extern int TestEvent(DEVICE_EXTENSION *pdx, int nArea);
#endif