/*
 *  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.
 */

/*
 * 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/fcntl.h>
#include <linux/compiler.h>
#include "comedi_fc.h"
#include "../comedidev.h"

#define DRIVER_VERSION "v1.0"
#define DRIVER_AUTHOR "Bernd Porr, BerndPorr@f2s.com"
#define DRIVER_DESC "USB-DUXfast, BerndPorr@f2s.com"
#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 addresses 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 in bytes
 */
#define SIZEOFDUXBUFFER 256

/*
 * 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 ;-)
 *
 * steps at 30MHz in the FX2
 */
#define MIN_SAMPLING_PERIOD     9

/*
 * 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 struct 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
 */
struct usbduxfastsub_s {
        int attached;           /* is attached? */
        int probed;             /* is it associated with a subdevice? */
        struct usb_device *usbdev;      /* pointer to the usb-device */
        struct urb *urbIn;      /* BULK-transfer handling: urb */
        int8_t *transfer_buffer;
        int16_t *insnBuffer;    /* input buffer for single insn */
        int ifnum;              /* interface number */
        struct usb_interface *interface;        /* interface structure */
        /* comedi device for the interrupt context */
        struct comedi_device *comedidev;
        short int ai_cmd_running;       /* asynchronous command is running */
        short int ai_continous; /* continous aquisition */
        long int ai_sample_count;       /* number of samples to acquire */
        uint8_t *dux_commands;  /* commands */
        int ignore;             /* counter which ignores the first
                                   buffers */
        struct semaphore sem;
};

/*
 * 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 struct usbduxfastsub_s usbduxfastsub[NUMUSBDUXFAST];

static DEFINE_SEMAPHORE(start_stop_sem);

/*
 * bulk transfers to usbduxfast
 */
#define SENDADCOMMANDS            0
#define SENDINITEP6               1

static int send_dux_commands(struct usbduxfastsub_s *udfs, int cmd_type)
{
        int tmp, nsent;

        udfs->dux_commands[0] = cmd_type;

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: usbduxfast: dux_commands: ",
               udfs->comedidev->minor);
        for (tmp = 0; tmp < SIZEOFDUXBUFFER; tmp++)
                printk(" %02x", udfs->dux_commands[tmp]);
        printk("\n");
#endif

        tmp = usb_bulk_msg(udfs->usbdev,
                           usb_sndbulkpipe(udfs->usbdev, CHANNELLISTEP),
                           udfs->dux_commands, SIZEOFDUXBUFFER, &nsent, 10000);
        if (tmp < 0)
                printk(KERN_ERR "comedi%d: could not transmit dux_commands to"
                       "the usb-device, err=%d\n", udfs->comedidev->minor, tmp);
        return tmp;
}

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

        if (udfs && udfs->urbIn) {
                udfs->ai_cmd_running = 0;
                /* waits until a running transfer is over */
                usb_kill_urb(udfs->urbIn);
                j = 0;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "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(struct usbduxfastsub_s *udfs, int do_unlink)
{
        int ret = 0;

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

        udfs->ai_cmd_running = 0;

        if (do_unlink)
                /* stop aquistion */
                ret = usbduxfastsub_unlink_InURBs(udfs);

        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(struct comedi_device *dev,
                                struct comedi_subdevice *s)
{
        struct usbduxfastsub_s *udfs;
        int ret;

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

        return ret;
}

/*
 * analogue IN
 * interrupt service routine
 */
static void usbduxfastsub_ai_Irq(struct urb *urb)
{
        int n, err;
        struct usbduxfastsub_s *udfs;
        struct comedi_device *this_comedidev;
        struct comedi_subdevice *s;
        uint16_t *p;

        /* sanity checks - is the urb there? */
        if (!urb) {
                printk(KERN_ERR "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(KERN_ERR "comedi_: usbduxfast_: urb context is a NULL "
                       "pointer!\n");
                return;
        }
        /* the private structure of the subdevice is usbduxfastsub_s */
        udfs = this_comedidev->private;
        if (!udfs) {
                printk(KERN_ERR "comedi_: usbduxfast_: private of comedi "
                       "subdev is a NULL pointer!\n");
                return;
        }
        /* are we running a command? */
        if (unlikely(!udfs->ai_cmd_running)) {
                /*
                 * not running a command
                 * do not continue execution if no asynchronous command
                 * is running in particular not resubmit
                 */
                return;
        }

        if (unlikely(!udfs->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(udfs->comedidev, s);
                /* stop the transfer w/o unlink */
                usbduxfast_ai_stop(udfs, 0);
                return;

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

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

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

        } else {
                /* ignore this packet */
                udfs->ignore--;
        }

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

static int usbduxfastsub_start(struct usbduxfastsub_s *udfs)
{
        int ret;
        unsigned char local_transfer_buffer[16];

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

        return 0;
}

static int usbduxfastsub_stop(struct usbduxfastsub_s *udfs)
{
        int ret;
        unsigned char local_transfer_buffer[16];

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

        return 0;
}

static int usbduxfastsub_upload(struct usbduxfastsub_s *udfs,
                                unsigned char *local_transfer_buffer,
                                unsigned int startAddr, unsigned int len)
{
        int ret;

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi: usbduxfast: uploading %d bytes", len);
        printk(KERN_DEBUG " to addr %d, first byte=%d.\n",
               startAddr, local_transfer_buffer[0]);
#endif
        /* brequest, firmware */
        ret = usb_control_msg(udfs->usbdev, usb_sndctrlpipe(udfs->usbdev, 0), USBDUXFASTSUB_FIRMWARE,
                                VENDOR_DIR_OUT, /* bmRequestType */
                                startAddr,      /* value */
                                0x0000, /* index */
                                /* our local safe buffer */
                                local_transfer_buffer,
                                len,    /* length */
                                EZTIMEOUT);     /* timeout */

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi_: usbduxfast: result=%d\n", ret);
#endif

        if (ret < 0) {
                printk(KERN_ERR "comedi_: usbduxfast: uppload failed\n");
                return ret;
        }

        return 0;
}

static int usbduxfastsub_submit_InURBs(struct usbduxfastsub_s *udfs)
{
        int ret;

        if (!udfs)
                return -EFAULT;

        usb_fill_bulk_urb(udfs->urbIn, udfs->usbdev,
                          usb_rcvbulkpipe(udfs->usbdev, BULKINEP),
                          udfs->transfer_buffer,
                          SIZEINBUF, usbduxfastsub_ai_Irq, udfs->comedidev);

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: usbduxfast: submitting in-urb: "
               "0x%p,0x%p\n", udfs->comedidev->minor, udfs->urbIn->context,
               udfs->urbIn->dev);
#endif
        ret = usb_submit_urb(udfs->urbIn, GFP_ATOMIC);
        if (ret) {
                printk(KERN_ERR "comedi_: usbduxfast: ai: usb_submit_urb error"
                       " %d\n", ret);
                return ret;
        }
        return 0;
}

static int usbduxfast_ai_cmdtest(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
                                 struct comedi_cmd *cmd)
{
        int err = 0, stop_mask = 0;
        long int steps, tmp;
        int minSamplPer;
        struct usbduxfastsub_s *udfs = dev->private;

        if (!udfs->probed)
                return -ENODEV;

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: usbduxfast_ai_cmdtest\n", dev->minor);
        printk(KERN_DEBUG "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(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
                                 unsigned int trignum)
{
        int ret;
        struct usbduxfastsub_s *udfs = dev->private;

        if (!udfs)
                return -EFAULT;

        down(&udfs->sem);
        if (!udfs->probed) {
                up(&udfs->sem);
                return -ENODEV;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: usbduxfast_ai_inttrig\n", dev->minor);
#endif

        if (trignum != 0) {
                printk(KERN_ERR "comedi%d: usbduxfast_ai_inttrig: invalid"
                       " trignum\n", dev->minor);
                up(&udfs->sem);
                return -EINVAL;
        }
        if (!udfs->ai_cmd_running) {
                udfs->ai_cmd_running = 1;
                ret = usbduxfastsub_submit_InURBs(udfs);
                if (ret < 0) {
                        printk(KERN_ERR "comedi%d: usbduxfast_ai_inttrig: "
                               "urbSubmit: err=%d\n", dev->minor, ret);
                        udfs->ai_cmd_running = 0;
                        up(&udfs->sem);
                        return ret;
                }
                s->async->inttrig = NULL;
        } else {
                printk(KERN_ERR "comedi%d: ai_inttrig but acqu is already"
                       " running\n", dev->minor);
        }
        up(&udfs->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(struct comedi_device *dev,
                             struct comedi_subdevice *s)
{
        struct comedi_cmd *cmd = &s->async->cmd;
        unsigned int chan, gain, rngmask = 0xff;
        int i, j, ret;
        struct usbduxfastsub_s *udfs;
        int result;
        long steps, steps_tmp;

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: usbduxfast_ai_cmd\n", dev->minor);
#endif
        udfs = dev->private;
        if (!udfs)
                return -EFAULT;

        down(&udfs->sem);
        if (!udfs->probed) {
                up(&udfs->sem);
                return -ENODEV;
        }
        if (udfs->ai_cmd_running) {
                printk(KERN_ERR "comedi%d: ai_cmd not possible. Another ai_cmd"
                       " is running.\n", dev->minor);
                up(&udfs->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
         */
        udfs->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(KERN_ERR "comedi%d: cmd is accepting "
                                       "only consecutive channels.\n",
                                       dev->minor);
                                up(&udfs->sem);
                                return -EINVAL;
                        }
                        if ((gain != CR_RANGE(cmd->chanlist[i]))
                            && (cmd->chanlist_len > 3)) {
                                printk(KERN_ERR "comedi%d: the gain must be"
                                       " the same for all channels.\n",
                                       dev->minor);
                                up(&udfs->sem);
                                return -EINVAL;
                        }
                        if (i >= NUMCHANNELS) {
                                printk(KERN_ERR "comedi%d: channel list too"
                                       " long\n", dev->minor);
                                break;
                        }
                }
        }
        steps = 0;
        if (cmd->scan_begin_src == TRIG_TIMER) {
                printk(KERN_ERR "comedi%d: usbduxfast: "
                       "scan_begin_src==TRIG_TIMER not valid.\n", dev->minor);
                up(&udfs->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(KERN_ERR "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(&udfs->sem);
                return -EINVAL;
        }
        if (steps > MAX_SAMPLING_PERIOD) {
                printk(KERN_ERR "comedi%d: usbduxfast: ai_cmd: sampling rate "
                       "too low.\n", dev->minor);
                up(&udfs->sem);
                return -EINVAL;
        }
        if ((cmd->start_src == TRIG_EXT) && (cmd->chanlist_len != 1)
            && (cmd->chanlist_len != 16)) {
                printk(KERN_ERR "comedi%d: usbduxfast: ai_cmd: TRIG_EXT only"
                       " with 1 or 16 channels possible.\n", dev->minor);
                up(&udfs->sem);
                return -EINVAL;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: usbduxfast: steps=%ld, convert_arg=%u\n",
               dev->minor, steps, cmd->convert_arg);
#endif

        switch (cmd->chanlist_len) {
        case 1:
                /*
                 * one channel
                 */

                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
                 */

                /* we loop here until ready has been set */
                if (cmd->start_src == TRIG_EXT) {
                        /* branch back to state 0 */
                        udfs->dux_commands[LENBASE + 0] = 0x01;
                        /* deceision state w/o data */
                        udfs->dux_commands[OPBASE + 0] = 0x01;
                        udfs->dux_commands[OUTBASE + 0] = 0xFF & rngmask;
                        /* RDY0 = 0 */
                        udfs->dux_commands[LOGBASE + 0] = 0x00;
                } else {        /* we just proceed to state 1 */
                        udfs->dux_commands[LENBASE + 0] = 1;
                        udfs->dux_commands[OPBASE + 0] = 0;
                        udfs->dux_commands[OUTBASE + 0] = 0xFF & rngmask;
                        udfs->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
                                 */

                                /* branch back to state 1 */
                                udfs->dux_commands[LENBASE + 1] = 0x89;
                                /* deceision state with data */
                                udfs->dux_commands[OPBASE + 1] = 0x03;
                                udfs->dux_commands[OUTBASE + 1] =
                                    0xFF & rngmask;
                                /* doesn't matter */
                                udfs->dux_commands[LOGBASE + 1] = 0xFF;
                        } else {
                                /*
                                 * we loop through two states: data and delay
                                 * max rate is 15MHz
                                 */
                                udfs->dux_commands[LENBASE + 1] = steps - 1;
                                /* data */
                                udfs->dux_commands[OPBASE + 1] = 0x02;
                                udfs->dux_commands[OUTBASE + 1] =
                                    0xFF & rngmask;
                                /* doesn't matter */
                                udfs->dux_commands[LOGBASE + 1] = 0;
                                /* branch back to state 1 */
                                udfs->dux_commands[LENBASE + 2] = 0x09;
                                /* deceision state w/o data */
                                udfs->dux_commands[OPBASE + 2] = 0x01;
                                udfs->dux_commands[OUTBASE + 2] =
                                    0xFF & rngmask;
                                /* doesn't matter */
                                udfs->dux_commands[LOGBASE + 2] = 0xFF;
                        }
                } 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 */
                        udfs->dux_commands[LENBASE + 1] = steps / 2;
                        udfs->dux_commands[OPBASE + 1] = 0;
                        udfs->dux_commands[OUTBASE + 1] = 0xFF & rngmask;
                        udfs->dux_commands[LOGBASE + 1] = 0;

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

                        /* get the data and branch back */

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

        case 2:
                /*
                 * two channels
                 * commit data to the FIFO
                 */

                if (CR_RANGE(cmd->chanlist[0]) > 0)
                        rngmask = 0xff - 0x04;
                else
                        rngmask = 0xff;

                udfs->dux_commands[LENBASE + 0] = 1;
                /* data */
                udfs->dux_commands[OPBASE + 0] = 0x02;
                udfs->dux_commands[OUTBASE + 0] = 0xFF & rngmask;
                udfs->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 */
                udfs->dux_commands[LENBASE + 1] = steps_tmp / 2;
                udfs->dux_commands[OPBASE + 1] = 0;
                /* count */
                udfs->dux_commands[OUTBASE + 1] = 0xFE & rngmask;
                udfs->dux_commands[LOGBASE + 1] = 0;

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

                udfs->dux_commands[LENBASE + 3] = 1;
                /* data */
                udfs->dux_commands[OPBASE + 3] = 0x02;
                udfs->dux_commands[OUTBASE + 3] = 0xFF & rngmask;
                udfs->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 */
                udfs->dux_commands[LENBASE + 4] = steps_tmp / 2;
                udfs->dux_commands[OPBASE + 4] = 0;
                /* reset */
                udfs->dux_commands[OUTBASE + 4] = (0xFF - 0x02) & rngmask;
                udfs->dux_commands[LOGBASE + 4] = 0;

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

                udfs->dux_commands[LENBASE + 6] = 1;
                udfs->dux_commands[OPBASE + 6] = 0;
                udfs->dux_commands[OUTBASE + 6] = 0xFF & rngmask;
                udfs->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
                         */
                        udfs->dux_commands[LENBASE + j * 2] = steps / 2;
                        /* data */
                        udfs->dux_commands[OPBASE + j * 2] = 0x02;
                        /* no change */
                        udfs->dux_commands[OUTBASE + j * 2] = 0xFF & rngmask;
                        udfs->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 */
                        udfs->dux_commands[LENBASE + j * 2 + 1] =
                            steps - steps / 2;
                        /* no data */
                        udfs->dux_commands[OPBASE + j * 2 + 1] = 0;
                        /* count */
                        udfs->dux_commands[OUTBASE + j * 2 + 1] =
                            0xFE & rngmask;
                        udfs->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 */
                udfs->dux_commands[LENBASE + 4] = steps_tmp / 2;
                /* data */
                udfs->dux_commands[OPBASE + 4] = 0x02;
                udfs->dux_commands[OUTBASE + 4] = 0xFF & rngmask;
                udfs->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 */
                udfs->dux_commands[LENBASE + 5] = steps_tmp - steps_tmp / 2;
                /* no data */
                udfs->dux_commands[OPBASE + 5] = 0;
                /* reset */
                udfs->dux_commands[OUTBASE + 5] = (0xFF - 0x02) & rngmask;
                udfs->dux_commands[LOGBASE + 5] = 0;

                udfs->dux_commands[LENBASE + 6] = 1;
                udfs->dux_commands[OPBASE + 6] = 0;
                udfs->dux_commands[OUTBASE + 6] = 0xFF & rngmask;
                udfs->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
                         */

                        /* branch back to state 0 */
                        udfs->dux_commands[LENBASE + 0] = 0x01;
                        /* deceision state w/o data */
                        udfs->dux_commands[OPBASE + 0] = 0x01;
                        /* reset */
                        udfs->dux_commands[OUTBASE + 0] =
                            (0xFF - 0x02) & rngmask;
                        /* RDY0 = 0 */
                        udfs->dux_commands[LOGBASE + 0] = 0x00;
                } else {
                        /*
                         * we just proceed to state 1
                         */

                        /* 30us reset pulse */
                        udfs->dux_commands[LENBASE + 0] = 255;
                        udfs->dux_commands[OPBASE + 0] = 0;
                        /* reset */
                        udfs->dux_commands[OUTBASE + 0] =
                            (0xFF - 0x02) & rngmask;
                        udfs->dux_commands[LOGBASE + 0] = 0;
                }

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

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

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

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

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

                break;

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

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

        if ((cmd->start_src == TRIG_NOW) || (cmd->start_src == TRIG_EXT)) {
                /* enable this acquisition operation */
                udfs->ai_cmd_running = 1;
                ret = usbduxfastsub_submit_InURBs(udfs);
                if (ret < 0) {
                        udfs->ai_cmd_running = 0;
                        /* fixme: unlink here?? */
                        up(&udfs->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(&udfs->sem);

        return 0;
}

/*
 * Mode 0 is used to get a single conversion on demand.
 */
static int usbduxfast_ai_insn_read(struct comedi_device *dev,
                                   struct comedi_subdevice *s,
                                   struct comedi_insn *insn, unsigned int *data)
{
        int i, j, n, actual_length;
        int chan, range, rngmask;
        int err;
        struct usbduxfastsub_s *udfs;

        udfs = dev->private;
        if (!udfs) {
                printk(KERN_ERR "comedi%d: ai_insn_read: no usb dev.\n",
                       dev->minor);
                return -ENODEV;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: ai_insn_read, insn->n=%d, "
               "insn->subdev=%d\n", dev->minor, insn->n, insn->subdev);
#endif
        down(&udfs->sem);
        if (!udfs->probed) {
                up(&udfs->sem);
                return -ENODEV;
        }
        if (udfs->ai_cmd_running) {
                printk(KERN_ERR "comedi%d: ai_insn_read not possible. Async "
                       "Command is running.\n", dev->minor);
                up(&udfs->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 */
        udfs->dux_commands[LENBASE + 0] = 1;
        /* data */
        udfs->dux_commands[OPBASE + 0] = 0x02;
        udfs->dux_commands[OUTBASE + 0] = 0xFF & rngmask;
        udfs->dux_commands[LOGBASE + 0] = 0;

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

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

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

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

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

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

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

#define FIRMWARE_MAX_LEN 0x2000

static int firmwareUpload(struct usbduxfastsub_s *usbduxfastsub,
                          const u8 *firmwareBinary, int sizeFirmware)
{
        int ret;
        uint8_t *fwBuf;

        if (!firmwareBinary)
                return 0;

        if (sizeFirmware > FIRMWARE_MAX_LEN) {
                dev_err(&usbduxfastsub->interface->dev,
                        "comedi_: usbduxfast firmware binary it too large for FX2.\n");
                return -ENOMEM;
        }

        /* we generate a local buffer for the firmware */
        fwBuf = kmemdup(firmwareBinary, sizeFirmware, GFP_KERNEL);
        if (!fwBuf) {
                dev_err(&usbduxfastsub->interface->dev,
                        "comedi_: mem alloc for firmware failed\n");
                return -ENOMEM;
        }

        ret = usbduxfastsub_stop(usbduxfastsub);
        if (ret < 0) {
                dev_err(&usbduxfastsub->interface->dev,
                        "comedi_: can not stop firmware\n");
                kfree(fwBuf);
                return ret;
        }

        ret = usbduxfastsub_upload(usbduxfastsub, fwBuf, 0, sizeFirmware);
        if (ret < 0) {
                dev_err(&usbduxfastsub->interface->dev,
                        "comedi_: firmware upload failed\n");
                kfree(fwBuf);
                return ret;
        }
        ret = usbduxfastsub_start(usbduxfastsub);
        if (ret < 0) {
                dev_err(&usbduxfastsub->interface->dev,
                        "comedi_: can not start firmware\n");
                kfree(fwBuf);
                return ret;
        }
        kfree(fwBuf);
        return 0;
}

static void tidy_up(struct usbduxfastsub_s *udfs)
{
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi_: usbduxfast: tiding up\n");
#endif

        if (!udfs)
                return;

        /* shows the usb subsystem that the driver is down */
        if (udfs->interface)
                usb_set_intfdata(udfs->interface, NULL);

        udfs->probed = 0;

        if (udfs->urbIn) {
                /* waits until a running transfer is over */
                usb_kill_urb(udfs->urbIn);

                kfree(udfs->transfer_buffer);
                udfs->transfer_buffer = NULL;

                usb_free_urb(udfs->urbIn);
                udfs->urbIn = NULL;
        }

        kfree(udfs->insnBuffer);
        udfs->insnBuffer = NULL;

        kfree(udfs->dux_commands);
        udfs->dux_commands = NULL;

        udfs->ai_cmd_running = 0;
}

static void usbduxfast_firmware_request_complete_handler(const struct firmware
                                                         *fw, void *context)
{
        struct usbduxfastsub_s *usbduxfastsub_tmp = 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 once we've left this function
         */
        ret = firmwareUpload(usbduxfastsub_tmp, fw->data, fw->size);

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

        comedi_usb_auto_config(usbdev, BOARDNAME);
 out:
        release_firmware(fw);
}

/*
 * allocate memory for the urbs and initialise them
 */
static int usbduxfastsub_probe(struct usb_interface *uinterf,
                               const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(uinterf);
        int i;
        int index;
        int ret;

        if (udev->speed != USB_SPEED_HIGH) {
                printk(KERN_ERR "comedi_: usbduxfast_: This driver needs"
                       "USB 2.0 to operate. Aborting...\n");
                return -ENODEV;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "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(KERN_ERR "Too many usbduxfast-devices connected.\n");
                up(&start_stop_sem);
                return -EMFILE;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi_: usbduxfast: usbduxfastsub[%d] is ready to "
               "connect to comedi.\n", index);
#endif

        sema_init(&(usbduxfastsub[index].sem), 1);
        /* save a pointer to the usb device */
        usbduxfastsub[index].usbdev = udev;

        /* 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]));

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "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(KERN_ERR "comedi_: usbduxfast: error alloc space for "
                       "dac commands\n");
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        /* create space of the instruction buffer */
        usbduxfastsub[index].insnBuffer = kmalloc(SIZEINSNBUF, GFP_KERNEL);
        if (!usbduxfastsub[index].insnBuffer) {
                printk(KERN_ERR "comedi_: usbduxfast: could not alloc space "
                       "for insnBuffer\n");
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                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(KERN_ERR "comedi_: usbduxfast%d: could not switch to "
                       "alternate setting 1.\n", index);
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return -ENODEV;
        }
        usbduxfastsub[index].urbIn = usb_alloc_urb(0, GFP_KERNEL);
        if (!usbduxfastsub[index].urbIn) {
                printk(KERN_ERR "comedi_: usbduxfast%d: Could not alloc."
                       "urb\n", index);
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        usbduxfastsub[index].transfer_buffer = kmalloc(SIZEINBUF, GFP_KERNEL);
        if (!usbduxfastsub[index].transfer_buffer) {
                printk(KERN_ERR "comedi_: usbduxfast%d: could not alloc. "
                       "transb.\n", index);
                tidy_up(&(usbduxfastsub[index]));
                up(&start_stop_sem);
                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.bin",
                                      &udev->dev,
                                      GFP_KERNEL,
                                      usbduxfastsub + index,
                                      usbduxfast_firmware_request_complete_handler);

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

        printk(KERN_INFO "comedi_: usbduxfast%d has been successfully "
               "initialized.\n", index);
        /* success */
        return 0;
}

static void usbduxfastsub_disconnect(struct usb_interface *intf)
{
        struct usbduxfastsub_s *udfs = usb_get_intfdata(intf);
        struct usb_device *udev = interface_to_usbdev(intf);

        if (!udfs) {
                printk(KERN_ERR "comedi_: usbduxfast: disconnect called with "
                       "null pointer.\n");
                return;
        }
        if (udfs->usbdev != udev) {
                printk(KERN_ERR "comedi_: usbduxfast: BUG! called with wrong "
                       "ptr!!!\n");
                return;
        }

        comedi_usb_auto_unconfig(udev);

        down(&start_stop_sem);
        down(&udfs->sem);
        tidy_up(udfs);
        up(&udfs->sem);
        up(&start_stop_sem);

#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi_: usbduxfast: disconnected from the usb\n");
#endif
}

/*
 * is called when comedi-config is called
 */
static int usbduxfast_attach(struct comedi_device *dev,
                             struct comedi_devconfig *it)
{
        int ret;
        int index;
        int i;
        struct 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(KERN_ERR "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]) {
                firmwareUpload(&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 */
        ret = alloc_subdevices(dev, N_SUBDEVICES);
        if (ret < 0) {
                printk(KERN_ERR "comedi%d: usbduxfast: error alloc space for "
                       "subdev\n", dev->minor);
                up(&(usbduxfastsub[index].sem));
                up(&start_stop_sem);
                return ret;
        }

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

        return 0;
}

static int usbduxfast_detach(struct comedi_device *dev)
{
        struct usbduxfastsub_s *udfs;

        if (!dev) {
                printk(KERN_ERR "comedi?: usbduxfast: detach without dev "
                       "variable...\n");
                return -EFAULT;
        }
#ifdef CONFIG_COMEDI_DEBUG
        printk(KERN_DEBUG "comedi%d: usbduxfast: detach usb device\n",
               dev->minor);
#endif

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

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

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

/*
 * Table with the USB-devices: just now only testing IDs
 */
static const 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 init_usbduxfast(void)
{
        printk(KERN_INFO
               KBUILD_MODNAME ": " DRIVER_VERSION ":" DRIVER_DESC "\n");
        usb_register(&usbduxfastsub_driver);
        comedi_driver_register(&driver_usbduxfast);
        return 0;
}

/*
 * deregistering the comedi driver and the usb-subsystem
 */
static void __exit 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");