comedi/comedi/drivers/usbduxfast.c

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#define DRIVER_VERSION "v1.0"
#define DRIVER_AUTHOR "Bernd Porr, BerndPorr@f2s.com"
#define DRIVER_DESC "USB-DUXfast, BerndPorr@f2s.com"
/*
   comedi/drivers/usbduxfast.c
   Copyright (C) 2004 Bernd Porr, Bernd.Porr@f2s.com

   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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
Driver: usbduxfast
Description: ITL USB-DUXfast
Devices: [ITL] USB-DUX (usbduxfast.o)
Author: Bernd Porr <BerndPorr@f2s.com>
Updated: 08 Dec 2008
Status: stable
*/

/*
 * I must give credit here to Chris Baugher who
 * wrote the driver for AT-MIO-16d. I used some parts of this
 * driver. I also must give credits to David Brownell
 * who supported me with the USB development.
 *
 * Bernd Porr
 *
 *
 * Revision history:
 * 0.9: Dropping the first data packet which seems to be from the last transfer.
 *      Buffer overflows in the FX2 are handed over to comedi.
 * 0.92: Dropping now 4 packets. The quad buffer has to be emptied.
 *       Added insn command basically for testing. Sample rate is 1MHz/16ch=62.5kHz
 * 0.99: Ian Abbott pointed out a bug which has been corrected. Thanks!
 * 0.99a: added external trigger.
 * 1.00: added firmware kernel request to the driver which fixed
 *       udev coldplug problem
 */

#include <linux/kernel.h>
#include <linux/firmware.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/usb.h>
#include <linux/smp_lock.h>
#include <linux/fcntl.h>
#include <linux/compiler.h>
#include "comedi_fc.h"
#include <linux/comedidev.h>
#include <linux/usb.h>

// (un)comment this if you want to have debug info.
//#define CONFIG_COMEDI_DEBUG
#undef  CONFIG_COMEDI_DEBUG

#define BOARDNAME "usbduxfast"

// timeout for the USB-transfer
#define EZTIMEOUT 30

// constants for "firmware" upload and download
#define USBDUXFASTSUB_FIRMWARE 0xA0
#define VENDOR_DIR_IN  0xC0
#define VENDOR_DIR_OUT 0x40

// internal adresses of the 8051 processor
#define USBDUXFASTSUB_CPUCS 0xE600

// max lenghth of the transfer-buffer for software upload
#define TB_LEN 0x2000

// Input endpoint number
#define BULKINEP           6

// Endpoint for the A/D channellist: bulk OUT
#define CHANNELLISTEP     4

// Number of channels
#define NUMCHANNELS       32

// size of the waveform descriptor
#define WAVESIZE          0x20

// Size of one A/D value
#define SIZEADIN          ((sizeof(int16_t)))

// Size of the input-buffer IN BYTES
#define SIZEINBUF         512

// 16 bytes.
#define SIZEINSNBUF       512

// Size of the buffer for the dux commands
#define SIZEOFDUXBUFFER    256  // bytes

// Number of in-URBs which receive the data: min=5
#define NUMOFINBUFFERSHIGH     10

// Total number of usbduxfast devices
#define NUMUSBDUXFAST             16

// Number of subdevices
#define N_SUBDEVICES          1

// Analogue in subdevice
#define SUBDEV_AD             0

// min delay steps for more than one channel
// basically when the mux gives up. ;-)
#define MIN_SAMPLING_PERIOD 9   // steps at 30MHz in the FX2

// Max number of 1/30MHz delay steps:
#define MAX_SAMPLING_PERIOD 500

// Number of received packets to ignore before we start handing data over to comedi.
// It's quad buffering and we have to ignore 4 packets.
#define PACKETS_TO_IGNORE 4

// comedi constants
static const comedi_lrange range_usbduxfast_ai_range = { 2, {
                        BIP_RANGE(0.75),
                        BIP_RANGE(0.5),
        }
};

/*
 * private structure of one subdevice
 */

// This is the structure which holds all the data of this driver
// one sub device just now: A/D
typedef struct {
        // attached?
        int attached;
        // is it associated with a subdevice?
        int probed;
        // pointer to the usb-device
        struct usb_device *usbdev;
        // BULK-transfer handling: urb
        struct urb *urbIn;
        int8_t *transfer_buffer;
        // input buffer for single insn
        int16_t *insnBuffer;
        // interface number
        int ifnum;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
        // interface structure in 2.6
        struct usb_interface *interface;
#endif
        // comedi device for the interrupt context
        comedi_device *comedidev;
        // asynchronous command is running
        short int ai_cmd_running;
        // continous aquisition
        short int ai_continous;
        // number of samples to aquire
        long int ai_sample_count;
        // commands
        uint8_t *dux_commands;
        // counter which ignores the first buffers
        int ignore;
        struct semaphore sem;
} usbduxfastsub_t;

// The pointer to the private usb-data of the driver
// is also the private data for the comedi-device.
// This has to be global as the usb subsystem needs
// global variables. The other reason is that this
// structure must be there _before_ any comedi
// command is issued. The usb subsystem must be
// initialised before comedi can access it.
static usbduxfastsub_t usbduxfastsub[NUMUSBDUXFAST];

static DECLARE_MUTEX(start_stop_sem);

// bulk transfers to usbduxfast

#define SENDADCOMMANDS            0
#define SENDINITEP6               1

static int send_dux_commands(usbduxfastsub_t * this_usbduxfastsub, int cmd_type)
{
        int result, nsent;
        this_usbduxfastsub->dux_commands[0] = cmd_type;
#ifdef CONFIG_COMEDI_DEBUG
        int i;
        printk("comedi%d: usbduxfast: dux_commands: ",
                this_usbduxfastsub->comedidev->minor);
        for (i = 0; i < SIZEOFDUXBUFFER; i++) {
                printk(" %02x", this_usbduxfastsub->dux_commands[i]);
        }
        printk("\n");
#endif
        result = USB_BULK_MSG(this_usbduxfastsub->usbdev,
                usb_sndbulkpipe(this_usbduxfastsub->usbdev,
                        CHANNELLISTEP),
                this_usbduxfastsub->dux_commands,
                SIZEOFDUXBUFFER, &nsent, 10000);
        if (result < 0) {
                printk("comedi%d: could not transmit dux_commands to the usb-device, err=%d\n", this_usbduxfastsub->comedidev->minor, result);
        }
        return result;
}

// Stops the data acquision
// It should be safe to call this function from any context
static int usbduxfastsub_unlink_InURBs(usbduxfastsub_t * usbduxfastsub_tmp)
{
        int j = 0;
        int err = 0;

        if (usbduxfastsub_tmp && usbduxfastsub_tmp->urbIn) {
                usbduxfastsub_tmp->ai_cmd_running = 0;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,8)
                j = usb_unlink_urb(usbduxfastsub_tmp->urbIn);
                if (j < 0) {
                        err = j;
                }
#else
                // waits until a running transfer is over
                usb_kill_urb(usbduxfastsub_tmp->urbIn);
                j = 0;
#endif
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi: usbduxfast: unlinked InURB: res=%d\n", j);
#endif
        return err;
}

/* This will stop a running acquisition operation */
// Is called from within this driver from both the
// interrupt context and from comedi
static int usbduxfast_ai_stop(usbduxfastsub_t * this_usbduxfastsub,
        int do_unlink)
{
        int ret = 0;

        if (!this_usbduxfastsub) {
                printk("comedi?: usbduxfast_ai_stop: this_usbduxfastsub=NULL!\n");
                return -EFAULT;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi: usbduxfast_ai_stop\n");
#endif

        this_usbduxfastsub->ai_cmd_running = 0;

        if (do_unlink) {
                // stop aquistion
                ret = usbduxfastsub_unlink_InURBs(this_usbduxfastsub);
        }

        return ret;
}

// This will cancel a running acquisition operation.
// This is called by comedi but never from inside the
// driver.
static int usbduxfast_ai_cancel(comedi_device * dev, comedi_subdevice * s)
{
        usbduxfastsub_t *this_usbduxfastsub;
        int res = 0;

        // force unlink of all urbs
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi: usbduxfast_ai_cancel\n");
#endif
        this_usbduxfastsub = dev->private;
        if (!this_usbduxfastsub) {
                printk("comedi: usbduxfast_ai_cancel: this_usbduxfastsub=NULL\n");
                return -EFAULT;
        }
        down(&this_usbduxfastsub->sem);
        if (!(this_usbduxfastsub->probed)) {
                up(&this_usbduxfastsub->sem);
                return -ENODEV;
        }
        // unlink
        res = usbduxfast_ai_stop(this_usbduxfastsub, 1);
        up(&this_usbduxfastsub->sem);

        return res;
}

// analogue IN
// interrupt service routine
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
static void usbduxfastsub_ai_Irq(struct urb *urb)
#else
static void usbduxfastsub_ai_Irq(struct urb *urb PT_REGS_ARG)
#endif
{
        int n, err;
        usbduxfastsub_t *this_usbduxfastsub;
        comedi_device *this_comedidev;
        comedi_subdevice *s;
        uint16_t *p;

        // sanity checks
        // is the urb there?
        if (!urb) {
                printk("comedi_: usbduxfast_: ao int-handler called with urb=NULL!\n");
                return;
        }
        // the context variable points to the subdevice
        this_comedidev = urb->context;
        if (!this_comedidev) {
                printk("comedi_: usbduxfast_: urb context is a NULL pointer!\n");
                return;
        }
        // the private structure of the subdevice is usbduxfastsub_t
        this_usbduxfastsub = this_comedidev->private;
        if (!this_usbduxfastsub) {
                printk("comedi_: usbduxfast_: private of comedi subdev is a NULL pointer!\n");
                return;
        }
        // are we running a command?
        if (unlikely(!(this_usbduxfastsub->ai_cmd_running))) {
                // not running a command
                // do not continue execution if no asynchronous command is running
                // in particular not resubmit
                return;
        }

        if (unlikely(!(this_usbduxfastsub->attached))) {
                // no comedi device there
                return;
        }
        // subdevice which is the AD converter
        s = this_comedidev->subdevices + SUBDEV_AD;

        // first we test if something unusual has just happened
        switch (urb->status) {
        case 0:
                break;

                // happens after an unlink command or when the device is plugged out
        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
        case -ECONNABORTED:
                // tell this comedi
                s->async->events |= COMEDI_CB_EOA;
                s->async->events |= COMEDI_CB_ERROR;
                comedi_event(this_usbduxfastsub->comedidev, s);
                // stop the transfer w/o unlink
                usbduxfast_ai_stop(this_usbduxfastsub, 0);
                return;

        default:
                printk("comedi%d: usbduxfast: non-zero urb status received in ai intr context: %d\n", this_usbduxfastsub->comedidev->minor, urb->status);
                s->async->events |= COMEDI_CB_EOA;
                s->async->events |= COMEDI_CB_ERROR;
                comedi_event(this_usbduxfastsub->comedidev, s);
                usbduxfast_ai_stop(this_usbduxfastsub, 0);
                return;
        }

        p = urb->transfer_buffer;
        if (!this_usbduxfastsub->ignore) {
                if (!(this_usbduxfastsub->ai_continous)) {
                        // not continous, fixed number of samples
                        n = urb->actual_length / sizeof(uint16_t);
                        if (unlikely(this_usbduxfastsub->ai_sample_count < n)) {
                                // we have send only a fraction of the bytes received
                                cfc_write_array_to_buffer(s,
                                        urb->transfer_buffer,
                                        this_usbduxfastsub->ai_sample_count *
                                        sizeof(uint16_t));
                                usbduxfast_ai_stop(this_usbduxfastsub, 0);
                                // say comedi that the acquistion is over
                                s->async->events |= COMEDI_CB_EOA;
                                comedi_event(this_usbduxfastsub->comedidev, s);
                                return;
                        }
                        this_usbduxfastsub->ai_sample_count -= n;
                }
                // write the full buffer to comedi
                err = cfc_write_array_to_buffer(s,
                                                urb->transfer_buffer, urb->actual_length);

                if (unlikely(err == 0)) {
                        /* buffer overflow */
                        usbduxfast_ai_stop(this_usbduxfastsub, 0);
                        return;
                }

                // tell comedi that data is there
                comedi_event(this_usbduxfastsub->comedidev, s);

        } else {
                // ignore this packet
                this_usbduxfastsub->ignore--;
        }

        // command is still running
        // resubmit urb for BULK transfer
        urb->dev = this_usbduxfastsub->usbdev;
        urb->status = 0;
        if ((err = USB_SUBMIT_URB(urb)) < 0) {
                printk("comedi%d: usbduxfast: urb resubm failed: %d",
                        this_usbduxfastsub->comedidev->minor, err);
                s->async->events |= COMEDI_CB_EOA;
                s->async->events |= COMEDI_CB_ERROR;
                comedi_event(this_usbduxfastsub->comedidev, s);
                usbduxfast_ai_stop(this_usbduxfastsub, 0);
        }
}

static int usbduxfastsub_start(usbduxfastsub_t * usbduxfastsub)
{
        int errcode = 0;
        unsigned char local_transfer_buffer[16];

        // 7f92 to zero
        local_transfer_buffer[0] = 0;
        errcode = USB_CONTROL_MSG(usbduxfastsub->usbdev,
                                  // create a pipe for a control transfer
                                  usb_sndctrlpipe(usbduxfastsub->usbdev, 0),
                                  // bRequest, "Firmware"
                                  USBDUXFASTSUB_FIRMWARE,
                                  // bmRequestType
                                  VENDOR_DIR_OUT,
                                  // Value
                                  USBDUXFASTSUB_CPUCS,
                                  // Index
                                  0x0000,
                                  // address of the transfer buffer
                                  local_transfer_buffer,
                                  // Length
                                  1,
                                  // Timeout
                                  EZTIMEOUT);
        if (errcode < 0) {
                printk("comedi_: usbduxfast_: control msg failed (start)\n");
                return errcode;
        }
        return 0;
}

static int usbduxfastsub_stop(usbduxfastsub_t * usbduxfastsub)
{
        int errcode = 0;

        unsigned char local_transfer_buffer[16];
        // 7f92 to one
        local_transfer_buffer[0] = 1;
        errcode = USB_CONTROL_MSG
                (usbduxfastsub->usbdev,
                 usb_sndctrlpipe(usbduxfastsub->usbdev, 0),
                 // bRequest, "Firmware"
                 USBDUXFASTSUB_FIRMWARE,
                 // bmRequestType
                 VENDOR_DIR_OUT,
                 // Value
                 USBDUXFASTSUB_CPUCS,
                 // Index
                 0x0000, local_transfer_buffer,
                 // Length
                 1,
                 // Timeout
                 EZTIMEOUT);
        if (errcode < 0) {
                printk("comedi_: usbduxfast: control msg failed (stop)\n");
                return errcode;
        }
        return 0;
}

static int usbduxfastsub_upload(usbduxfastsub_t * usbduxfastsub,
        unsigned char *local_transfer_buffer,
        unsigned int startAddr, unsigned int len)
{
        int errcode;

        errcode = USB_CONTROL_MSG
                (usbduxfastsub->usbdev,
                 usb_sndctrlpipe(usbduxfastsub->usbdev, 0),
                 // brequest, firmware
                 USBDUXFASTSUB_FIRMWARE,
                 // bmRequestType
                 VENDOR_DIR_OUT,
                 // value
                 startAddr,
                 // index
                 0x0000,
                 // our local safe buffer
                 local_transfer_buffer,
                 // length
                 len,
                 // timeout
                 EZTIMEOUT);
        if (errcode < 0) {
                printk("comedi_: usbduxfast: uppload failed\n");
                return errcode;
        }
        return 0;
}

int firmwareUpload(usbduxfastsub_t * usbduxfastsub,
        unsigned char *firmwareBinary, int sizeFirmware)
{
        int ret;

        if (!firmwareBinary) {
                return 0;
        }
        ret = usbduxfastsub_stop(usbduxfastsub);
        if (ret < 0) {
                printk("comedi_: usbduxfast: can not stop firmware\n");
                return ret;
        }
        ret = usbduxfastsub_upload(usbduxfastsub,
                firmwareBinary, 0, sizeFirmware);
        if (ret < 0) {
                printk("comedi_: usbduxfast: firmware upload failed\n");
                return ret;
        }
        ret = usbduxfastsub_start(usbduxfastsub);
        if (ret < 0) {
                printk("comedi_: usbduxfast: can not start firmware\n");
                return ret;
        }
        return 0;
}

int usbduxfastsub_submit_InURBs(usbduxfastsub_t * usbduxfastsub)
{
        int errFlag;

        if (!usbduxfastsub) {
                return -EFAULT;
        }
        usb_fill_bulk_urb(usbduxfastsub->urbIn,
                usbduxfastsub->usbdev,
                usb_rcvbulkpipe(usbduxfastsub->usbdev, BULKINEP),
                usbduxfastsub->transfer_buffer,
                SIZEINBUF, usbduxfastsub_ai_Irq, usbduxfastsub->comedidev);

#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast: submitting in-urb: %x,%x\n",
                usbduxfastsub->comedidev->minor,
                (int)(usbduxfastsub->urbIn->context),
                (int)(usbduxfastsub->urbIn->dev));
#endif
        errFlag = USB_SUBMIT_URB(usbduxfastsub->urbIn);
        if (errFlag) {
                printk("comedi_: usbduxfast: ai: ");
                printk("USB_SUBMIT_URB");
                printk(" error %d\n", errFlag);
                return errFlag;
        }
        return 0;
}

static int usbduxfast_ai_cmdtest(comedi_device * dev,
        comedi_subdevice * s, comedi_cmd * cmd)
{
        int err = 0, stop_mask = 0;
        long int steps, tmp = 0;
        int minSamplPer;
        usbduxfastsub_t *this_usbduxfastsub = dev->private;
        if (!(this_usbduxfastsub->probed)) {
                return -ENODEV;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast_ai_cmdtest\n", dev->minor);
        printk("comedi%d: usbduxfast: convert_arg=%u scan_begin_arg=%u\n",
                dev->minor, cmd->convert_arg, cmd->scan_begin_arg);
#endif
        /* step 1: make sure trigger sources are trivially valid */

        tmp = cmd->start_src;
        cmd->start_src &= TRIG_NOW | TRIG_EXT | TRIG_INT;
        if (!cmd->start_src || tmp != cmd->start_src)
                err++;

        tmp = cmd->scan_begin_src;
        cmd->scan_begin_src &= TRIG_TIMER | TRIG_FOLLOW | TRIG_EXT;
        if (!cmd->scan_begin_src || tmp != cmd->scan_begin_src)
                err++;

        tmp = cmd->convert_src;
        cmd->convert_src &= TRIG_TIMER | TRIG_EXT;
        if (!cmd->convert_src || tmp != cmd->convert_src)
                err++;

        tmp = cmd->scan_end_src;
        cmd->scan_end_src &= TRIG_COUNT;
        if (!cmd->scan_end_src || tmp != cmd->scan_end_src)
                err++;

        tmp = cmd->stop_src;
        stop_mask = TRIG_COUNT | TRIG_NONE;
        cmd->stop_src &= stop_mask;
        if (!cmd->stop_src || tmp != cmd->stop_src)
                err++;

        if (err)
                return 1;

        /* step 2: make sure trigger sources are unique and mutually compatible */

        if (cmd->start_src != TRIG_NOW &&
                cmd->start_src != TRIG_EXT && cmd->start_src != TRIG_INT)
                err++;
        if (cmd->scan_begin_src != TRIG_TIMER &&
                cmd->scan_begin_src != TRIG_FOLLOW &&
                cmd->scan_begin_src != TRIG_EXT)
                err++;
        if (cmd->convert_src != TRIG_TIMER && cmd->convert_src != TRIG_EXT)
                err++;
        if (cmd->stop_src != TRIG_COUNT &&
                cmd->stop_src != TRIG_EXT && cmd->stop_src != TRIG_NONE)
                err++;

        // can't have external stop and start triggers at once
        if (cmd->start_src == TRIG_EXT && cmd->stop_src == TRIG_EXT)
                err++;

        if (err)
                return 2;

        /* step 3: make sure arguments are trivially compatible */

        if (cmd->start_src == TRIG_NOW && cmd->start_arg != 0) {
                cmd->start_arg = 0;
                err++;
        }

        if (!cmd->chanlist_len) {
                err++;
        }
        if (cmd->scan_end_arg != cmd->chanlist_len) {
                cmd->scan_end_arg = cmd->chanlist_len;
                err++;
        }

        if (cmd->chanlist_len == 1) {
                minSamplPer = 1;
        } else {
                minSamplPer = MIN_SAMPLING_PERIOD;
        }

        if (cmd->convert_src == TRIG_TIMER) {
                steps = cmd->convert_arg * 30;
                if (steps < (minSamplPer * 1000)) {
                        steps = minSamplPer * 1000;
                }
                if (steps > (MAX_SAMPLING_PERIOD * 1000)) {
                        steps = MAX_SAMPLING_PERIOD * 1000;
                }
                // calc arg again
                tmp = steps / 30;
                if (cmd->convert_arg != tmp) {
                        cmd->convert_arg = tmp;
                        err++;
                }
        }

        if (cmd->scan_begin_src == TRIG_TIMER) {
                err++;
        }
        // stop source
        switch (cmd->stop_src) {
        case TRIG_COUNT:
                if (!cmd->stop_arg) {
                        cmd->stop_arg = 1;
                        err++;
                }
                break;
        case TRIG_NONE:
                if (cmd->stop_arg != 0) {
                        cmd->stop_arg = 0;
                        err++;
                }
                break;
                // TRIG_EXT doesn't care since it doesn't trigger off a numbered channel
        default:
                break;
        }

        if (err)
                return 3;

        /* step 4: fix up any arguments */

        return 0;

}

static int usbduxfast_ai_inttrig(comedi_device * dev,
        comedi_subdevice * s, unsigned int trignum)
{
        int ret;
        usbduxfastsub_t *this_usbduxfastsub = dev->private;
        if (!this_usbduxfastsub) {
                return -EFAULT;
        }
        down(&this_usbduxfastsub->sem);
        if (!(this_usbduxfastsub->probed)) {
                up(&this_usbduxfastsub->sem);
                return -ENODEV;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast_ai_inttrig\n", dev->minor);
#endif

        if (trignum != 0) {
                printk("comedi%d: usbduxfast_ai_inttrig: invalid trignum\n",
                        dev->minor);
                up(&this_usbduxfastsub->sem);
                return -EINVAL;
        }
        if (!(this_usbduxfastsub->ai_cmd_running)) {
                this_usbduxfastsub->ai_cmd_running = 1;
                ret = usbduxfastsub_submit_InURBs(this_usbduxfastsub);
                if (ret < 0) {
                        printk("comedi%d: usbduxfast_ai_inttrig: urbSubmit: err=%d\n", dev->minor, ret);
                        this_usbduxfastsub->ai_cmd_running = 0;
                        up(&this_usbduxfastsub->sem);
                        return ret;
                }
                s->async->inttrig = NULL;
        } else {
                printk("comedi%d: ai_inttrig but acqu is already running\n",
                        dev->minor);
        }
        up(&this_usbduxfastsub->sem);
        return 1;
}

// offsets for the GPIF bytes
// the first byte is the command byte
#define LENBASE 1+0x00
#define OPBASE  1+0x08
#define OUTBASE 1+0x10
#define LOGBASE 1+0x18

static int usbduxfast_ai_cmd(comedi_device * dev, comedi_subdevice * s)
{
        comedi_cmd *cmd = &s->async->cmd;
        unsigned int chan, gain, rngmask = 0xff;
        int i, j, ret;
        usbduxfastsub_t *this_usbduxfastsub = dev->private;
        int result;
        long steps, steps_tmp;

#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast_ai_cmd\n", dev->minor);
#endif
        if (!this_usbduxfastsub) {
                return -EFAULT;
        }
        down(&this_usbduxfastsub->sem);
        if (!(this_usbduxfastsub->probed)) {
                up(&this_usbduxfastsub->sem);
                return -ENODEV;
        }
        if (this_usbduxfastsub->ai_cmd_running) {
                printk("comedi%d: ai_cmd not possible. Another ai_cmd is running.\n", dev->minor);
                up(&this_usbduxfastsub->sem);
                return -EBUSY;
        }
        // set current channel of the running aquisition to zero
        s->async->cur_chan = 0;

        // ignore the first buffers from the device if there is an error condition
        this_usbduxfastsub->ignore = PACKETS_TO_IGNORE;

        if (cmd->chanlist_len > 0) {
                gain = CR_RANGE(cmd->chanlist[0]);
                for (i = 0; i < cmd->chanlist_len; ++i) {
                        chan = CR_CHAN(cmd->chanlist[i]);
                        if (chan != i) {
                                printk("comedi%d: cmd is accepting only consecutive channels.\n", dev->minor);
                                up(&this_usbduxfastsub->sem);
                                return -EINVAL;
                        }
                        if ((gain != CR_RANGE(cmd->chanlist[i]))
                                && (cmd->chanlist_len > 3)) {
                                printk("comedi%d: the gain must be the same for all channels.\n", dev->minor);
                                up(&this_usbduxfastsub->sem);
                                return -EINVAL;
                        }
                        if (i >= NUMCHANNELS) {
                                printk("comedi%d: channel list too long\n",
                                        dev->minor);
                                break;
                        }
                }
        }
        steps = 0;
        if (cmd->scan_begin_src == TRIG_TIMER) {
                printk("comedi%d: usbduxfast: scan_begin_src==TRIG_TIMER not valid.\n", dev->minor);
                up(&this_usbduxfastsub->sem);
                return -EINVAL;
        }
        if (cmd->convert_src == TRIG_TIMER) {
                steps = (cmd->convert_arg * 30) / 1000;
        }
        if ((steps < MIN_SAMPLING_PERIOD) && (cmd->chanlist_len != 1)) {
                printk("comedi%d: usbduxfast: ai_cmd: steps=%ld, scan_begin_arg=%d. Not properly tested by cmdtest?\n", dev->minor, steps, cmd->scan_begin_arg);
                up(&this_usbduxfastsub->sem);
                return -EINVAL;
        }
        if (steps > MAX_SAMPLING_PERIOD) {
                printk("comedi%d: usbduxfast: ai_cmd: sampling rate too low.\n",
                        dev->minor);
                up(&this_usbduxfastsub->sem);
                return -EINVAL;
        }
        if ((cmd->start_src == TRIG_EXT) && (cmd->chanlist_len != 1)
                && (cmd->chanlist_len != 16)) {
                printk("comedi%d: usbduxfast: ai_cmd: TRIG_EXT only with 1 or 16 channels possible.\n", dev->minor);
                up(&this_usbduxfastsub->sem);
                return -EINVAL;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast: steps=%ld, convert_arg=%u, ai_timer=%u\n",
                dev->minor,
                steps, cmd->convert_arg, this_usbduxfastsub->ai_timer);
#endif

        switch (cmd->chanlist_len) {
                // one channel
        case 1:
                if (CR_RANGE(cmd->chanlist[0]) > 0)
                        rngmask = 0xff - 0x04;
                else
                        rngmask = 0xff;

                // for external trigger: looping in this state until the RDY0 pin
                // becomes zero
                if (cmd->start_src == TRIG_EXT) {       // we loop here until ready has been set
                        this_usbduxfastsub->dux_commands[LENBASE + 0] = 0x01;   // branch back to state 0
                        this_usbduxfastsub->dux_commands[OPBASE + 0] = 0x01;    // deceision state w/o data
                        this_usbduxfastsub->dux_commands[OUTBASE + 0] =
                                0xFF & rngmask;
                        this_usbduxfastsub->dux_commands[LOGBASE + 0] = 0x00;   // RDY0 = 0
                } else {        // we just proceed to state 1
                        this_usbduxfastsub->dux_commands[LENBASE + 0] = 1;
                        this_usbduxfastsub->dux_commands[OPBASE + 0] = 0;
                        this_usbduxfastsub->dux_commands[OUTBASE + 0] =
                                0xFF & rngmask;
                        this_usbduxfastsub->dux_commands[LOGBASE + 0] = 0;
                }

                if (steps < MIN_SAMPLING_PERIOD) {
                        // for fast single channel aqu without mux
                        if (steps <= 1) {
                                // we just stay here at state 1 and rexecute the same state
                                // this gives us 30MHz sampling rate
                                this_usbduxfastsub->dux_commands[LENBASE + 1] = 0x89;   // branch back to state 1
                                this_usbduxfastsub->dux_commands[OPBASE + 1] = 0x03;    // deceision state with data
                                this_usbduxfastsub->dux_commands[OUTBASE + 1] =
                                        0xFF & rngmask;
                                this_usbduxfastsub->dux_commands[LOGBASE + 1] = 0xFF;   // doesn't matter
                        } else {
                                // we loop through two states: data and delay: max rate is 15Mhz
                                this_usbduxfastsub->dux_commands[LENBASE + 1] =
                                        steps - 1;
                                this_usbduxfastsub->dux_commands[OPBASE + 1] = 0x02;    // data
                                this_usbduxfastsub->dux_commands[OUTBASE + 1] =
                                        0xFF & rngmask;
                                this_usbduxfastsub->dux_commands[LOGBASE + 1] = 0;      // doesn't matter

                                this_usbduxfastsub->dux_commands[LENBASE + 2] = 0x09;   // branch back to state 1
                                this_usbduxfastsub->dux_commands[OPBASE + 2] = 0x01;    // deceision state w/o data
                                this_usbduxfastsub->dux_commands[OUTBASE + 2] =
                                        0xFF & rngmask;
                                this_usbduxfastsub->dux_commands[LOGBASE + 2] = 0xFF;   // doesn't matter
                        }
                } else {
                        // we loop through 3 states: 2x delay and 1x data. This gives a min
                        // sampling rate of 60kHz.

                        // we have 1 state with duration 1
                        steps = steps - 1;

                        // do the first part of the delay
                        this_usbduxfastsub->dux_commands[LENBASE + 1] =
                                steps / 2;
                        this_usbduxfastsub->dux_commands[OPBASE + 1] = 0;
                        this_usbduxfastsub->dux_commands[OUTBASE + 1] =
                                0xFF & rngmask;
                        this_usbduxfastsub->dux_commands[LOGBASE + 1] = 0;

                        // and the second part
                        this_usbduxfastsub->dux_commands[LENBASE + 2] =
                                steps - steps / 2;
                        this_usbduxfastsub->dux_commands[OPBASE + 2] = 0;
                        this_usbduxfastsub->dux_commands[OUTBASE + 2] =
                                0xFF & rngmask;
                        this_usbduxfastsub->dux_commands[LOGBASE + 2] = 0;

                        // get the data and branch back
                        this_usbduxfastsub->dux_commands[LENBASE + 3] = 0x09;   // branch back to state 1
                        this_usbduxfastsub->dux_commands[OPBASE + 3] = 0x03;    // deceision state w data
                        this_usbduxfastsub->dux_commands[OUTBASE + 3] =
                                0xFF & rngmask;
                        this_usbduxfastsub->dux_commands[LOGBASE + 3] = 0xFF;   // doesn't matter
                }
                break;

        case 2:
                // two channels
                // commit data to the FIFO
                if (CR_RANGE(cmd->chanlist[0]) > 0)
                        rngmask = 0xff - 0x04;
                else
                        rngmask = 0xff;
                this_usbduxfastsub->dux_commands[LENBASE + 0] = 1;
                this_usbduxfastsub->dux_commands[OPBASE + 0] = 0x02;    // data
                this_usbduxfastsub->dux_commands[OUTBASE + 0] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 0] = 0;

                // we have 1 state with duration 1: state 0
                steps_tmp = steps - 1;

                if (CR_RANGE(cmd->chanlist[1]) > 0)
                        rngmask = 0xff - 0x04;
                else
                        rngmask = 0xff;
                // do the first part of the delay
                this_usbduxfastsub->dux_commands[LENBASE + 1] = steps_tmp / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 1] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 1] = 0xFE & rngmask; //count
                this_usbduxfastsub->dux_commands[LOGBASE + 1] = 0;

                // and the second part
                this_usbduxfastsub->dux_commands[LENBASE + 2] =
                        steps_tmp - steps_tmp / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 2] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 2] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 2] = 0;

                this_usbduxfastsub->dux_commands[LENBASE + 3] = 1;
                this_usbduxfastsub->dux_commands[OPBASE + 3] = 0x02;    // data
                this_usbduxfastsub->dux_commands[OUTBASE + 3] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 3] = 0;

                // we have 2 states with duration 1: step 6 and the IDLE state
                steps_tmp = steps - 2;

                if (CR_RANGE(cmd->chanlist[0]) > 0)
                        rngmask = 0xff - 0x04;
                else
                        rngmask = 0xff;
                // do the first part of the delay
                this_usbduxfastsub->dux_commands[LENBASE + 4] = steps_tmp / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 4] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 4] = (0xFF - 0x02) & rngmask;        //reset
                this_usbduxfastsub->dux_commands[LOGBASE + 4] = 0;

                // and the second part
                this_usbduxfastsub->dux_commands[LENBASE + 5] =
                        steps_tmp - steps_tmp / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 5] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 5] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 5] = 0;

                this_usbduxfastsub->dux_commands[LENBASE + 6] = 1;
                this_usbduxfastsub->dux_commands[OPBASE + 6] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 6] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 6] = 0;
                break;

        case 3:
                // three channels
                for (j = 0; j < 1; j++) {
                        if (CR_RANGE(cmd->chanlist[j]) > 0)
                                rngmask = 0xff - 0x04;
                        else
                                rngmask = 0xff;
                        // commit data to the FIFO and do the first part of the delay
                        this_usbduxfastsub->dux_commands[LENBASE + j * 2] =
                                steps / 2;
                        this_usbduxfastsub->dux_commands[OPBASE + j * 2] = 0x02;        // data
                        this_usbduxfastsub->dux_commands[OUTBASE + j * 2] = 0xFF & rngmask;     // no change
                        this_usbduxfastsub->dux_commands[LOGBASE + j * 2] = 0;

                        if (CR_RANGE(cmd->chanlist[j + 1]) > 0)
                                rngmask = 0xff - 0x04;
                        else
                                rngmask = 0xff;
                        // do the second part of the delay
                        this_usbduxfastsub->dux_commands[LENBASE + j * 2 + 1] =
                                steps - steps / 2;
                        this_usbduxfastsub->dux_commands[OPBASE + j * 2 + 1] = 0;       // no data
                        this_usbduxfastsub->dux_commands[OUTBASE + j * 2 + 1] = 0xFE & rngmask; //count
                        this_usbduxfastsub->dux_commands[LOGBASE + j * 2 + 1] =
                                0;
                }

                // 2 steps with duration 1: the idele step and step 6:
                steps_tmp = steps - 2;
                // commit data to the FIFO and do the first part of the delay
                this_usbduxfastsub->dux_commands[LENBASE + 4] = steps_tmp / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 4] = 0x02;    // data
                this_usbduxfastsub->dux_commands[OUTBASE + 4] = 0xFF & rngmask; // no change
                this_usbduxfastsub->dux_commands[LOGBASE + 4] = 0;

                if (CR_RANGE(cmd->chanlist[0]) > 0)
                        rngmask = 0xff - 0x04;
                else
                        rngmask = 0xff;
                // do the second part of the delay
                this_usbduxfastsub->dux_commands[LENBASE + 5] =
                        steps_tmp - steps_tmp / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 5] = 0;       // no data
                this_usbduxfastsub->dux_commands[OUTBASE + 5] = (0xFF - 0x02) & rngmask;        // reset
                this_usbduxfastsub->dux_commands[LOGBASE + 5] = 0;

                this_usbduxfastsub->dux_commands[LENBASE + 6] = 1;
                this_usbduxfastsub->dux_commands[OPBASE + 6] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 6] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 6] = 0;

        case 16:
                if (CR_RANGE(cmd->chanlist[0]) > 0)
                        rngmask = 0xff - 0x04;
                else
                        rngmask = 0xff;
                if (cmd->start_src == TRIG_EXT) {       // we loop here until ready has been set
                        this_usbduxfastsub->dux_commands[LENBASE + 0] = 0x01;   // branch back to state 0
                        this_usbduxfastsub->dux_commands[OPBASE + 0] = 0x01;    // deceision state w/o data
                        this_usbduxfastsub->dux_commands[OUTBASE + 0] = (0xFF - 0x02) & rngmask;        // reset
                        this_usbduxfastsub->dux_commands[LOGBASE + 0] = 0x00;   // RDY0 = 0
                } else {        // we just proceed to state 1
                        this_usbduxfastsub->dux_commands[LENBASE + 0] = 255;    // 30us reset pulse
                        this_usbduxfastsub->dux_commands[OPBASE + 0] = 0;
                        this_usbduxfastsub->dux_commands[OUTBASE + 0] = (0xFF - 0x02) & rngmask;        // reset
                        this_usbduxfastsub->dux_commands[LOGBASE + 0] = 0;
                }

                // commit data to the FIFO
                this_usbduxfastsub->dux_commands[LENBASE + 1] = 1;
                this_usbduxfastsub->dux_commands[OPBASE + 1] = 0x02;    // data
                this_usbduxfastsub->dux_commands[OUTBASE + 1] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 1] = 0;

                // we have 2 states with duration 1
                steps = steps - 2;

                // do the first part of the delay
                this_usbduxfastsub->dux_commands[LENBASE + 2] = steps / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 2] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 2] = 0xFE & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 2] = 0;

                // and the second part
                this_usbduxfastsub->dux_commands[LENBASE + 3] =
                        steps - steps / 2;
                this_usbduxfastsub->dux_commands[OPBASE + 3] = 0;
                this_usbduxfastsub->dux_commands[OUTBASE + 3] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 3] = 0;

                this_usbduxfastsub->dux_commands[LENBASE + 4] = 0x09;   // branch back to state 1
                this_usbduxfastsub->dux_commands[OPBASE + 4] = 0x01;    // deceision state w/o data
                this_usbduxfastsub->dux_commands[OUTBASE + 4] = 0xFF & rngmask;
                this_usbduxfastsub->dux_commands[LOGBASE + 4] = 0xFF;   // doesn't matter

                break;

        default:
                printk("comedi %d: unsupported combination of channels\n",
                        dev->minor);
                up(&this_usbduxfastsub->sem);
                return -EFAULT;
        }

#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi %d: sending commands to the usb device\n", dev->minor);
#endif
        // 0 means that the AD commands are sent
        result = send_dux_commands(this_usbduxfastsub, SENDADCOMMANDS);
        if (result < 0) {
                printk("comedi%d: adc command could not be submitted. Aborting...\n", dev->minor);
                up(&this_usbduxfastsub->sem);
                return result;
        }
        if (cmd->stop_src == TRIG_COUNT) {
                this_usbduxfastsub->ai_sample_count =
                        (cmd->stop_arg) * (cmd->scan_end_arg);
                if (usbduxfastsub->ai_sample_count < 1) {
                        printk("comedi%d: (cmd->stop_arg)*(cmd->scan_end_arg)<1, aborting.\n", dev->minor);
                        up(&this_usbduxfastsub->sem);
                        return -EFAULT;
                }
                this_usbduxfastsub->ai_continous = 0;
        } else {
                // continous aquisition
                this_usbduxfastsub->ai_continous = 1;
                this_usbduxfastsub->ai_sample_count = 0;
        }

        if ((cmd->start_src == TRIG_NOW) || (cmd->start_src == TRIG_EXT)) {
                // enable this acquisition operation
                this_usbduxfastsub->ai_cmd_running = 1;
                ret = usbduxfastsub_submit_InURBs(this_usbduxfastsub);
                if (ret < 0) {
                        this_usbduxfastsub->ai_cmd_running = 0;
                        // fixme: unlink here??
                        up(&this_usbduxfastsub->sem);
                        return ret;
                }
                s->async->inttrig = NULL;
        } else {
                /* TRIG_INT */
                // don't enable the acquision operation
                // wait for an internal signal
                s->async->inttrig = usbduxfast_ai_inttrig;
        }
        up(&this_usbduxfastsub->sem);

        return 0;
}

/* Mode 0 is used to get a single conversion on demand */
static int usbduxfast_ai_insn_read(comedi_device * dev,
        comedi_subdevice * s, comedi_insn * insn, lsampl_t * data)
{
        int i, j, n, actual_length;
        int chan, range, rngmask;
        int err;
        usbduxfastsub_t *usbduxfastsub = dev->private;

        if (!usbduxfastsub) {
                printk("comedi%d: ai_insn_read: no usb dev.\n", dev->minor);
                return -ENODEV;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: ai_insn_read, insn->n=%d, insn->subdev=%d\n",
                dev->minor, insn->n, insn->subdev);
#endif
        down(&usbduxfastsub->sem);
        if (!(usbduxfastsub->probed)) {
                up(&usbduxfastsub->sem);
                return -ENODEV;
        }
        if (usbduxfastsub->ai_cmd_running) {
                printk("comedi%d: ai_insn_read not possible. Async Command is running.\n", dev->minor);
                up(&usbduxfastsub->sem);
                return -EBUSY;
        }
        // sample one channel
        chan = CR_CHAN(insn->chanspec);
        range = CR_RANGE(insn->chanspec);
        // set command for the first channel

        if (range > 0)
                rngmask = 0xff - 0x04;
        else
                rngmask = 0xff;
        // commit data to the FIFO
        usbduxfastsub->dux_commands[LENBASE + 0] = 1;
        usbduxfastsub->dux_commands[OPBASE + 0] = 0x02; // data
        usbduxfastsub->dux_commands[OUTBASE + 0] = 0xFF & rngmask;
        usbduxfastsub->dux_commands[LOGBASE + 0] = 0;

        // do the first part of the delay
        usbduxfastsub->dux_commands[LENBASE + 1] = 12;
        usbduxfastsub->dux_commands[OPBASE + 1] = 0;
        usbduxfastsub->dux_commands[OUTBASE + 1] = 0xFE & rngmask;
        usbduxfastsub->dux_commands[LOGBASE + 1] = 0;

        usbduxfastsub->dux_commands[LENBASE + 2] = 1;
        usbduxfastsub->dux_commands[OPBASE + 2] = 0;
        usbduxfastsub->dux_commands[OUTBASE + 2] = 0xFE & rngmask;
        usbduxfastsub->dux_commands[LOGBASE + 2] = 0;

        usbduxfastsub->dux_commands[LENBASE + 3] = 1;
        usbduxfastsub->dux_commands[OPBASE + 3] = 0;
        usbduxfastsub->dux_commands[OUTBASE + 3] = 0xFE & rngmask;
        usbduxfastsub->dux_commands[LOGBASE + 3] = 0;

        usbduxfastsub->dux_commands[LENBASE + 4] = 1;
        usbduxfastsub->dux_commands[OPBASE + 4] = 0;
        usbduxfastsub->dux_commands[OUTBASE + 4] = 0xFE & rngmask;
        usbduxfastsub->dux_commands[LOGBASE + 4] = 0;

        // second part
        usbduxfastsub->dux_commands[LENBASE + 5] = 12;
        usbduxfastsub->dux_commands[OPBASE + 5] = 0;
        usbduxfastsub->dux_commands[OUTBASE + 5] = 0xFF & rngmask;
        usbduxfastsub->dux_commands[LOGBASE + 5] = 0;

        usbduxfastsub->dux_commands[LENBASE + 6] = 1;
        usbduxfastsub->dux_commands[OPBASE + 6] = 0;
        usbduxfastsub->dux_commands[OUTBASE + 6] = 0xFF & rngmask;
        usbduxfastsub->dux_commands[LOGBASE + 0] = 0;

#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi %d: sending commands to the usb device\n", dev->minor);
#endif
        // 0 means that the AD commands are sent
        err = send_dux_commands(usbduxfastsub, SENDADCOMMANDS);
        if (err < 0) {
                printk("comedi%d: adc command could not be submitted. Aborting...\n", dev->minor);
                up(&usbduxfastsub->sem);
                return err;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast: submitting in-urb: %x,%x\n",
                usbduxfastsub->comedidev->minor,
                (int)(usbduxfastsub->urbIn->context),
                (int)(usbduxfastsub->urbIn->dev));
#endif
        for (i = 0; i < PACKETS_TO_IGNORE; i++) {
                err = USB_BULK_MSG(usbduxfastsub->usbdev,
                        usb_rcvbulkpipe(usbduxfastsub->usbdev, BULKINEP),
                        usbduxfastsub->transfer_buffer,
                        SIZEINBUF, &actual_length, 10000);
                if (err < 0) {
                        printk("comedi%d: insn timeout. No data.\n",
                                dev->minor);
                        up(&usbduxfastsub->sem);
                        return err;
                }
        }
        // data points
        for (i = 0; i < insn->n;) {
                err = USB_BULK_MSG(usbduxfastsub->usbdev,
                        usb_rcvbulkpipe(usbduxfastsub->usbdev, BULKINEP),
                        usbduxfastsub->transfer_buffer,
                        SIZEINBUF, &actual_length, 10000);
                if (err < 0) {
                        printk("comedi%d: insn data error: %d\n",
                                dev->minor, err);
                        up(&usbduxfastsub->sem);
                        return err;
                }
                n = actual_length / sizeof(uint16_t);
                if ((n % 16) != 0) {
                        printk("comedi%d: insn data packet corrupted.\n",
                                dev->minor);
                        up(&usbduxfastsub->sem);
                        return -EINVAL;
                }
                for (j = chan; (j < n) && (i < insn->n); j = j + 16) {
                        data[i] =
                                ((uint16_t *) (usbduxfastsub->
                                        transfer_buffer))[j];
                        i++;
                }
        }
        up(&usbduxfastsub->sem);
        return i;
}

static unsigned hex2unsigned(char *h)
{
        unsigned hi, lo;
        if (h[0] > '9') {
                hi = h[0] - 'A' + 0x0a;
        } else {
                hi = h[0] - '0';
        }
        if (h[1] > '9') {
                lo = h[1] - 'A' + 0x0a;
        } else {
                lo = h[1] - '0';
        }
        return hi * 0x10 + lo;
}

// for FX2
#define FIRMWARE_MAX_LEN 0x2000

// taken from David Brownell's fxload and adjusted for this driver
static int read_firmware(usbduxfastsub_t * usbduxfastsub,
                         const void *firmwarePtr,
                         long size)
{
        int i = 0;
        unsigned char *fp = (char *)firmwarePtr;
        unsigned char *firmwareBinary = NULL;
        int res = 0;
        int maxAddr = 0;

        firmwareBinary = kmalloc(FIRMWARE_MAX_LEN, GFP_KERNEL);
        if (!firmwareBinary) {
                printk("comedi_: usbduxfast: mem alloc for firmware failed\n");
                return -ENOMEM;
        }

        for (;;) {
                char buf[256], *cp;
                char type;
                int len;
                int idx, off;
                int j = 0;

                // get one line
                while ((i < size) && (fp[i] != 13) && (fp[i] != 10)) {
                        buf[j] = fp[i];
                        i++;
                        j++;
                        if (j >= sizeof(buf)) {
                                printk("comedi_: usbduxfast: bogus firmware file!\n");
                                return -1;
                        }
                }
                // get rid of LF/CR/...
                while ((i < size) && ((fp[i] == 13) || (fp[i] == 10)
                                || (fp[i] == 0))) {
                        i++;
                }

                buf[j] = 0;
                //printk("comedi_: buf=%s\n",buf);

                /* EXTENSION: "# comment-till-end-of-line", for copyrights etc */
                if (buf[0] == '#')
                        continue;

                if (buf[0] != ':') {
                        printk("comedi_: usbduxfast: upload: not an ihex record: %s", buf);
                        return -EFAULT;
                }

                /* Read the length field (up to 16 bytes) */
                len = hex2unsigned(buf + 1);

                /* Read the target offset */
                off = (hex2unsigned(buf + 3) * 0x0100) + hex2unsigned(buf + 5);

                if ((off + len) > maxAddr) {
                        maxAddr = off + len;
                }

                if (maxAddr >= FIRMWARE_MAX_LEN) {
                        printk("comedi_: usbduxfast: firmware upload goes beyond FX2 RAM boundaries.");
                        return -EFAULT;
                }
                //printk("comedi_: usbduxfast: off=%x, len=%x:",off,len);

                /* Read the record type */
                type = hex2unsigned(buf + 7);

                /* If this is an EOF record, then make it so. */
                if (type == 1) {
                        break;
                }

                if (type != 0) {
                        printk("comedi_: usbduxfast: unsupported record type: %u\n", type);
                        return -EFAULT;
                }

                for (idx = 0, cp = buf + 9; idx < len; idx += 1, cp += 2) {
                        firmwareBinary[idx + off] = hex2unsigned(cp);
                        //printk("%02x ",firmwareBinary[idx+off]);
                }
                //printk("\n");

                if (i >= size) {
                        printk("comedi_: usbduxfast: unexpected end of hex file\n");
                        break;
                }

        }
        res = firmwareUpload(usbduxfastsub, firmwareBinary, maxAddr + 1);
        kfree(firmwareBinary);
        return res;
}

static void tidy_up(usbduxfastsub_t * usbduxfastsub_tmp)
{
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi_: usbduxfast: tiding up\n");
#endif
        if (!usbduxfastsub_tmp) {
                return;
        }
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
        // shows the usb subsystem that the driver is down
        if (usbduxfastsub_tmp->interface) {
                usb_set_intfdata(usbduxfastsub_tmp->interface, NULL);
        }
#endif

        usbduxfastsub_tmp->probed = 0;

        if (usbduxfastsub_tmp->urbIn) {
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,8)
                // waits until a running transfer is over
                // thus, under 2.4 hotplugging while a command
                // is running is not safe
                usb_kill_urb(usbduxfastsub_tmp->urbIn);
#endif
                if (usbduxfastsub_tmp->transfer_buffer) {
                        kfree(usbduxfastsub_tmp->transfer_buffer);
                        usbduxfastsub_tmp->transfer_buffer = NULL;
                }
                usb_free_urb(usbduxfastsub_tmp->urbIn);
                usbduxfastsub_tmp->urbIn = NULL;
        }
        if (usbduxfastsub_tmp->insnBuffer) {
                kfree(usbduxfastsub_tmp->insnBuffer);
                usbduxfastsub_tmp->insnBuffer = NULL;
        }
        if (usbduxfastsub_tmp->dux_commands) {
                kfree(usbduxfastsub_tmp->dux_commands);
                usbduxfastsub_tmp->dux_commands = NULL;
        }
        usbduxfastsub_tmp->ai_cmd_running = 0;
}

static void usbduxfast_firmware_request_complete_handler(
        const struct firmware *fw,
        void *context)
{
        usbduxfastsub_t * usbduxfastsub_tmp = (usbduxfastsub_t *)context;
        struct usb_device *usbdev = usbduxfastsub_tmp->usbdev;
        int ret;

        if(fw == NULL) {
                return;
        }

        // we need to upload the firmware here because fw will be
        // freed one we've left this function
        ret=read_firmware(usbduxfastsub_tmp,
                          fw->data,
                          fw->size);

        if (ret) {
                dev_err(&usbdev->dev,
                        "Could not upload firmware (err=%d)\n",
                        ret);
                return;
        }

        comedi_usb_auto_config(usbdev, BOARDNAME);
}

// allocate memory for the urbs and initialise them
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
static void *usbduxfastsub_probe(struct usb_device *udev,
                                 unsigned int interfnum,
                                 const struct usb_device_id *id)
{
#else
static int usbduxfastsub_probe(struct usb_interface *uinterf,
        const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(uinterf);
#endif
        int i;
        int index;
        int ret;

        if (udev->speed != USB_SPEED_HIGH) {
                printk("comedi_: usbduxfast_: This driver needs USB 2.0 to operate. Aborting...\n");
                return PROBE_ERR_RETURN(-ENODEV);
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi_: usbduxfast_: finding a free structure for the usb-device\n");
#endif
        down(&start_stop_sem);
        // look for a free place in the usbduxfast array
        index = -1;
        for (i = 0; i < NUMUSBDUXFAST; i++) {
                if (!(usbduxfastsub[i].probed)) {
                        index = i;
                        break;
                }
        }

        // no more space
        if (index == -1) {
                printk("Too many usbduxfast-devices connected.\n");
                up(&start_stop_sem);
                return PROBE_ERR_RETURN(-EMFILE);
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi_: usbduxfast: usbduxfastsub[%d] is ready to connect to comedi.\n", index);
#endif

        init_MUTEX(&(usbduxfastsub[index].sem));
        // save a pointer to the usb device
        usbduxfastsub[index].usbdev = udev;

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
        // save the interface number
        usbduxfastsub[index].ifnum = interfnum;
#else
        // 2.6: save the interface itself
        usbduxfastsub[index].interface = uinterf;
        // get the interface number from the interface
        usbduxfastsub[index].ifnum = uinterf->altsetting->desc.bInterfaceNumber;
        // hand the private data over to the usb subsystem
        // will be needed for disconnect
        usb_set_intfdata(uinterf, &(usbduxfastsub[index]));
#endif

#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi_: usbduxfast: ifnum=%d\n", usbduxfastsub[index].ifnum);
#endif
        // create space for the commands going to the usb device
        usbduxfastsub[index].dux_commands = kmalloc(SIZEOFDUXBUFFER,
                GFP_KERNEL);
        if (!usbduxfastsub[index].dux_commands) {
                printk("comedi_: usbduxfast: error alloc space for dac commands\n");
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return PROBE_ERR_RETURN(-ENOMEM);
        }
        // create space of the instruction buffer
        usbduxfastsub[index].insnBuffer = kmalloc(SIZEINSNBUF, GFP_KERNEL);
        if (!(usbduxfastsub[index].insnBuffer)) {
                printk("comedi_: usbduxfast: could not alloc space for insnBuffer\n");
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return PROBE_ERR_RETURN(-ENOMEM);
        }
        // setting to alternate setting 1: enabling bulk ep
        i = usb_set_interface(usbduxfastsub[index].usbdev,
                usbduxfastsub[index].ifnum, 1);
        if (i < 0) {
                printk("comedi_: usbduxfast%d: could not switch to alternate setting 1.\n", index);
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return PROBE_ERR_RETURN(-ENODEV);
        }
        usbduxfastsub[index].urbIn = USB_ALLOC_URB(0);
        if (usbduxfastsub[index].urbIn == NULL) {
                printk("comedi_: usbduxfast%d: Could not alloc. urb\n", index);
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return PROBE_ERR_RETURN(-ENOMEM);
        }
        usbduxfastsub[index].transfer_buffer = kmalloc(SIZEINBUF, GFP_KERNEL);
        if (!(usbduxfastsub[index].transfer_buffer)) {
                printk("comedi_: usbduxfast%d: could not alloc. transb.\n",
                        index);
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return PROBE_ERR_RETURN(-ENOMEM);
        }
        // we've reached the bottom of the function
        usbduxfastsub[index].probed = 1;
        up(&start_stop_sem);

        ret = request_firmware_nowait(THIS_MODULE,
                                      FW_ACTION_HOTPLUG,
                                      "usbduxfast_firmware.hex",
                                      &udev->dev,
                                      usbduxfastsub + index,
                                      usbduxfast_firmware_request_complete_handler);

        if (ret) {
                dev_err(&udev->dev,
                        "could not load firmware (err=%d)\n",
                        ret);
                return ret;
        }

        printk("comedi_: usbduxfast%d has been successfully initialized.\n",
               index);

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
        return (void *)(&usbduxfastsub[index]);
#else
        // success
        return 0;
#endif
}

#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,0)
static void usbduxfastsub_disconnect(struct usb_device *udev, void *ptr)
{
        usbduxfastsub_t *usbduxfastsub_tmp = (usbduxfastsub_t *) ptr;
#else
static void usbduxfastsub_disconnect(struct usb_interface *intf)
{
        usbduxfastsub_t *usbduxfastsub_tmp = usb_get_intfdata(intf);
        struct usb_device *udev = interface_to_usbdev(intf);
#endif
        if (!usbduxfastsub_tmp) {
                printk("comedi_: usbduxfast: disconnect called with null pointer.\n");
                return;
        }
        if (usbduxfastsub_tmp->usbdev != udev) {
                printk("comedi_: usbduxfast: BUG! called with wrong ptr!!!\n");
                return;
        }

        comedi_usb_auto_unconfig(udev);

        down(&start_stop_sem);
        down(&usbduxfastsub_tmp->sem);
        tidy_up(usbduxfastsub_tmp);
        up(&usbduxfastsub_tmp->sem);
        up(&start_stop_sem);
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi_: usbduxfast: disconnected from the usb\n");
#endif
}

// is called when comedi-config is called
static int usbduxfast_attach(comedi_device * dev, comedi_devconfig * it)
{
        int ret;
        int index;
        int i;
        comedi_subdevice *s = NULL;
        dev->private = NULL;

        down(&start_stop_sem);
        // find a valid device which has been detected by the probe function of the usb
        index = -1;
        for (i = 0; i < NUMUSBDUXFAST; i++) {
                if ((usbduxfastsub[i].probed) && (!usbduxfastsub[i].attached)) {
                        index = i;
                        break;
                }
        }

        if (index < 0) {
                printk("comedi%d: usbduxfast: error: attach failed, no usbduxfast devs connected to the usb bus.\n", dev->minor);
                up(&start_stop_sem);
                return -ENODEV;
        }

        down(&(usbduxfastsub[index].sem));
        // pointer back to the corresponding comedi device
        usbduxfastsub[index].comedidev = dev;

        // trying to upload the firmware into the chip
        if (comedi_aux_data(it->options, 0) &&
            it->options[COMEDI_DEVCONF_AUX_DATA_LENGTH]) {
                read_firmware(&usbduxfastsub[index],
                              comedi_aux_data(it->options, 0),
                              it->options[COMEDI_DEVCONF_AUX_DATA_LENGTH]);
        }

        dev->board_name = BOARDNAME;

        /* set number of subdevices */
        dev->n_subdevices = N_SUBDEVICES;

        // allocate space for the subdevices
        if ((ret = alloc_subdevices(dev, N_SUBDEVICES)) < 0) {
                printk("comedi%d: usbduxfast: error alloc space for subdev\n",
                        dev->minor);
                up(&start_stop_sem);
                return ret;
        }

        printk("comedi%d: usbduxfast: usb-device %d is attached to comedi.\n",
                dev->minor, index);
        // private structure is also simply the usb-structure
        dev->private = usbduxfastsub + index;
        // the first subdevice is the A/D converter
        s = dev->subdevices + SUBDEV_AD;
        // the URBs get the comedi subdevice
        // which is responsible for reading
        // this is the subdevice which reads data
        dev->read_subdev = s;
        // the subdevice receives as private structure the
        // usb-structure
        s->private = NULL;
        // analog input
        s->type = COMEDI_SUBD_AI;
        // readable and ref is to ground
        s->subdev_flags = SDF_READABLE | SDF_GROUND | SDF_CMD_READ;
        // 16 channels
        s->n_chan = 16;
        // length of the channellist
        s->len_chanlist = 16;
        // callback functions
        s->insn_read = usbduxfast_ai_insn_read;
        s->do_cmdtest = usbduxfast_ai_cmdtest;
        s->do_cmd = usbduxfast_ai_cmd;
        s->cancel = usbduxfast_ai_cancel;
        // max value from the A/D converter (12bit+1 bit for overflow)
        s->maxdata = 0x1000;
        // range table to convert to physical units
        s->range_table = &range_usbduxfast_ai_range;

        // finally decide that it's attached
        usbduxfastsub[index].attached = 1;

        up(&(usbduxfastsub[index].sem));

        up(&start_stop_sem);

        printk("comedi%d: successfully attached to usbduxfast.\n", dev->minor);

        return 0;
}

static int usbduxfast_detach(comedi_device * dev)
{
        usbduxfastsub_t *usbduxfastsub_tmp;

#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast: detach usb device\n", dev->minor);
#endif

        if (!dev) {
                printk("comedi?: usbduxfast: detach without dev variable...\n");
                return -EFAULT;
        }

        usbduxfastsub_tmp = dev->private;
        if (!usbduxfastsub_tmp) {
                printk("comedi?: usbduxfast: detach without ptr to usbduxfastsub[]\n");
                return -EFAULT;
        }

        down(&usbduxfastsub_tmp->sem);
        down(&start_stop_sem);
        // Don't allow detach to free the private structure
        // It's one entry of of usbduxfastsub[]
        dev->private = NULL;
        usbduxfastsub_tmp->attached = 0;
        usbduxfastsub_tmp->comedidev = NULL;
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi%d: usbduxfast: detach: successfully removed\n",
                dev->minor);
#endif
        up(&start_stop_sem);
        up(&usbduxfastsub_tmp->sem);
        return 0;
}

/* main driver struct */
static comedi_driver driver_usbduxfast = {
      driver_name:"usbduxfast",
      module:THIS_MODULE,
      attach:usbduxfast_attach,
      detach:usbduxfast_detach,
};

static void init_usb_devices(void)
{
        int index;
#ifdef CONFIG_COMEDI_DEBUG
        printk("comedi_: usbduxfast: setting all possible devs to invalid\n");
#endif
        // all devices entries are invalid to begin with
        // they will become valid by the probe function
        // and then finally by the attach-function
        for (index = 0; index < NUMUSBDUXFAST; index++) {
                memset(&(usbduxfastsub[index]), 0x00,
                        sizeof(usbduxfastsub[index]));
                init_MUTEX(&(usbduxfastsub[index].sem));
        }
}

// Table with the USB-devices: just now only testing IDs
static struct usb_device_id usbduxfastsub_table[] = {
        //        { USB_DEVICE(0x4b4, 0x8613), //testing
        //        },
        {USB_DEVICE(0x13d8, 0x0010)     //real ID
                },
        {USB_DEVICE(0x13d8, 0x0011)     //real ID
                },
        {}                      /* Terminating entry */
};

MODULE_DEVICE_TABLE(usb, usbduxfastsub_table);

// The usbduxfastsub-driver
static struct usb_driver usbduxfastsub_driver = {
#ifdef COMEDI_HAVE_USB_DRIVER_OWNER
      owner:THIS_MODULE,
#endif
      name:BOARDNAME,
      probe:usbduxfastsub_probe,
      disconnect:usbduxfastsub_disconnect,
      id_table:usbduxfastsub_table,
};

// Can't use the nice macro as I have also to initialise the USB
// subsystem:
// registering the usb-system _and_ the comedi-driver
static int init_usbduxfast(void)
{
        printk(KERN_INFO KBUILD_MODNAME ": "
               DRIVER_VERSION ":" DRIVER_DESC "\n");
        init_usb_devices();
        usb_register(&usbduxfastsub_driver);
        comedi_driver_register(&driver_usbduxfast);
        return 0;
}

// deregistering the comedi driver and the usb-subsystem
static void exit_usbduxfast(void)
{
        comedi_driver_unregister(&driver_usbduxfast);
        usb_deregister(&usbduxfastsub_driver);
}

module_init(init_usbduxfast);
module_exit(exit_usbduxfast);

MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");