/*
   comedi/drivers/usbdux.c
   Copyright (C) 2011 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: usbduxsigma
Description: University of Stirling USB DAQ & INCITE Technology Limited
Devices: [ITL] USB-DUX (usbduxsigma.o)
Author: Bernd Porr <BerndPorr@f2s.com>
Updated: 8 Nov 2011
Status: testing
*/
/*
 * 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.
 *
 * Note: the raw data from the A/D converter is 24 bit big endian
 * anything else is little endian to/from the dux board
 *
 *
 * Revision history:
 *   0.1: initial version
 *   0.2: all basic functions implemented, digital I/O only for one port
 *   0.3: proper vendor ID and driver name
 *   0.4: fixed D/A voltage range
 *   0.5: various bug fixes, health check at startup
 *   0.6: corrected wrong input range
 */

/* generates loads of debug info */
/* #define NOISY_DUX_DEBUGBUG */

#include <linux/kernel.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 <linux/firmware.h>
#include "comedi_fc.h"
#include "../comedidev.h"

/* timeout for the USB-transfer in ms*/
#define BULK_TIMEOUT 1000

/* constants for "firmware" upload and download */
#define FIRMWARE "usbduxsigma_firmware.bin"
#define USBDUXSUB_FIRMWARE 0xA0
#define VENDOR_DIR_IN  0xC0
#define VENDOR_DIR_OUT 0x40

/* internal addresses of the 8051 processor */
#define USBDUXSUB_CPUCS 0xE600

/*
 * the minor device number, major is 180 only for debugging purposes and to
 * upload special firmware (programming the eeprom etc) which is not
 * compatible with the comedi framwork
 */
#define USBDUXSUB_MINOR 32

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

/* Input endpoint number: ISO/IRQ */
#define ISOINEP           6

/* Output endpoint number: ISO/IRQ */
#define ISOOUTEP          2

/* This EP sends DUX commands to USBDUX */
#define COMMAND_OUT_EP     1

/* This EP receives the DUX commands from USBDUX */
#define COMMAND_IN_EP        8

/* Output endpoint for PWM */
#define PWM_EP         4

/* 300Hz max frequ under PWM */
#define MIN_PWM_PERIOD  ((long)(1E9/300))

/* Default PWM frequency */
#define PWM_DEFAULT_PERIOD ((long)(1E9/100))

/* Number of channels (16 AD and offset)*/
#define NUMCHANNELS 16

/* Size of one A/D value */
#define SIZEADIN          ((sizeof(int32_t)))

/*
 * Size of the async input-buffer IN BYTES, the DIO state is transmitted
 * as the first byte.
 */
#define SIZEINBUF         (((NUMCHANNELS+1)*SIZEADIN))

/* 16 bytes. */
#define SIZEINSNBUF       16

/* Number of DA channels */
#define NUMOUTCHANNELS    8

/* size of one value for the D/A converter: channel and value */
#define SIZEDAOUT          ((sizeof(uint8_t)+sizeof(int16_t)))

/*
 * Size of the output-buffer in bytes
 * Actually only the first 4 triplets are used but for the
 * high speed mode we need to pad it to 8 (microframes).
 */
#define SIZEOUTBUF         ((8*SIZEDAOUT))

/*
 * Size of the buffer for the dux commands: just now max size is determined
 * by the analogue out + command byte + panic bytes...
 */
#define SIZEOFDUXBUFFER    ((8*SIZEDAOUT+2))

/* Number of in-URBs which receive the data: min=2 */
#define NUMOFINBUFFERSFULL     5

/* Number of out-URBs which send the data: min=2 */
#define NUMOFOUTBUFFERSFULL    5

/* Number of in-URBs which receive the data: min=5 */
/* must have more buffers due to buggy USB ctr */
#define NUMOFINBUFFERSHIGH     10

/* Number of out-URBs which send the data: min=5 */
/* must have more buffers due to buggy USB ctr */
#define NUMOFOUTBUFFERSHIGH    10

/* Total number of usbdux devices */
#define NUMUSBDUX             16

/* Analogue in subdevice */
#define SUBDEV_AD             0

/* Analogue out subdevice */
#define SUBDEV_DA             1

/* Digital I/O */
#define SUBDEV_DIO            2

/* timer aka pwm output */
#define SUBDEV_PWM            3

/* number of retries to get the right dux command */
#define RETRIES 10

/**************************************************/
/* comedi constants */
static const struct comedi_lrange range_usbdux_ai_range = { 1, {
                                                                BIP_RANGE
                                                                (2.65/2.0)
                                                                }
};

/*
 * 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 usbduxsub {
        /* attached? */
        int attached;
        /* is it associated with a subdevice? */
        int probed;
        /* pointer to the usb-device */
        struct usb_device *usbdev;
        /* actual number of in-buffers */
        int numOfInBuffers;
        /* actual number of out-buffers */
        int numOfOutBuffers;
        /* ISO-transfer handling: buffers */
        struct urb **urbIn;
        struct urb **urbOut;
        /* pwm-transfer handling */
        struct urb *urbPwm;
        /* PWM period */
        unsigned int pwmPeriod;
        /* PWM internal delay for the GPIF in the FX2 */
        uint8_t pwmDelay;
        /* size of the PWM buffer which holds the bit pattern */
        int sizePwmBuf;
        /* input buffer for the ISO-transfer */
        int32_t *inBuffer;
        /* input buffer for single insn */
        int8_t *insnBuffer;
        /* output buffer for single DA outputs */
        int16_t *outBuffer;
        /* interface number */
        int ifnum;
        /* interface structure in 2.6 */
        struct usb_interface *interface;
        /* comedi device for the interrupt context */
        struct comedi_device *comedidev;
        /* is it USB_SPEED_HIGH or not? */
        short int high_speed;
        /* asynchronous command is running */
        short int ai_cmd_running;
        short int ao_cmd_running;
        /* pwm is running */
        short int pwm_cmd_running;
        /* continuous acquisition */
        short int ai_continuous;
        short int ao_continuous;
        /* number of samples to acquire */
        int ai_sample_count;
        int ao_sample_count;
        /* time between samples in units of the timer */
        unsigned int ai_timer;
        unsigned int ao_timer;
        /* counter between acquisitions */
        unsigned int ai_counter;
        unsigned int ao_counter;
        /* interval in frames/uframes */
        unsigned int ai_interval;
        /* D/A commands */
        uint8_t *dac_commands;
        /* commands */
        uint8_t *dux_commands;
        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 usbduxsub usbduxsub[NUMUSBDUX];

static DEFINE_SEMAPHORE(start_stop_sem);

/*
 * Stops the data acquision
 * It should be safe to call this function from any context
 */
static int usbduxsub_unlink_InURBs(struct usbduxsub *usbduxsub_tmp)
{
        int i = 0;
        int err = 0;

        if (usbduxsub_tmp && usbduxsub_tmp->urbIn) {
                for (i = 0; i < usbduxsub_tmp->numOfInBuffers; i++) {
                        if (usbduxsub_tmp->urbIn[i]) {
                                /* We wait here until all transfers have been
                                 * cancelled. */
                                usb_kill_urb(usbduxsub_tmp->urbIn[i]);
                        }
                        dev_dbg(&usbduxsub_tmp->interface->dev,
                                "comedi: usbdux: unlinked InURB %d, err=%d\n",
                                i, err);
                }
        }
        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 usbdux_ai_stop(struct usbduxsub *this_usbduxsub, int do_unlink)
{
        int ret = 0;

        if (!this_usbduxsub) {
                pr_err("comedi?: usbdux_ai_stop: this_usbduxsub=NULL!\n");
                return -EFAULT;
        }
        dev_dbg(&this_usbduxsub->interface->dev, "comedi: usbdux_ai_stop\n");

        if (do_unlink) {
                /* stop aquistion */
                ret = usbduxsub_unlink_InURBs(this_usbduxsub);
        }

        this_usbduxsub->ai_cmd_running = 0;

        return ret;
}

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

        /* force unlink of all urbs */
        this_usbduxsub = dev->private;
        if (!this_usbduxsub)
                return -EFAULT;

        dev_dbg(&this_usbduxsub->interface->dev, "comedi: usbdux_ai_cancel\n");

        /* prevent other CPUs from submitting new commands just now */
        down(&this_usbduxsub->sem);
        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        /* unlink only if the urb really has been submitted */
        res = usbdux_ai_stop(this_usbduxsub, this_usbduxsub->ai_cmd_running);
        up(&this_usbduxsub->sem);
        return res;
}

/* analogue IN - interrupt service routine */
static void usbduxsub_ai_IsocIrq(struct urb *urb)
{
        int i, err, n;
        struct usbduxsub *this_usbduxsub;
        struct comedi_device *this_comedidev;
        struct comedi_subdevice *s;
        int32_t v;
        unsigned int dio_state;

        /* the context variable points to the comedi device */
        this_comedidev = urb->context;
        /* the private structure of the subdevice is struct usbduxsub */
        this_usbduxsub = this_comedidev->private;
        /* 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:
                /* copy the result in the transfer buffer */
                memcpy(this_usbduxsub->inBuffer,
                       urb->transfer_buffer, SIZEINBUF);
                break;
        case -EILSEQ:
                /* error in the ISOchronous data */
                /* we don't copy the data into the transfer buffer */
                /* and recycle the last data byte */
                dev_dbg(&urb->dev->dev,
                        "comedi%d: usbdux: CRC error in ISO IN stream.\n",
                        this_usbduxsub->comedidev->minor);

                break;

        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
        case -ECONNABORTED:
                /* happens after an unlink command */
                if (this_usbduxsub->ai_cmd_running) {
                        /* we are still running a command */
                        /* tell this comedi */
                        s->async->events |= COMEDI_CB_EOA;
                        s->async->events |= COMEDI_CB_ERROR;
                        comedi_event(this_usbduxsub->comedidev, s);
                        /* stop the transfer w/o unlink */
                        usbdux_ai_stop(this_usbduxsub, 0);
                }
                return;

        default:
                /* a real error on the bus */
                /* pass error to comedi if we are really running a command */
                if (this_usbduxsub->ai_cmd_running) {
                        dev_err(&urb->dev->dev,
                                "Non-zero urb status received in ai intr "
                                "context: %d\n", urb->status);
                        s->async->events |= COMEDI_CB_EOA;
                        s->async->events |= COMEDI_CB_ERROR;
                        comedi_event(this_usbduxsub->comedidev, s);
                        /* don't do an unlink here */
                        usbdux_ai_stop(this_usbduxsub, 0);
                }
                return;
        }

        /*
         * at this point we are reasonably sure that nothing dodgy has happened
         * are we running a command?
         */
        if (unlikely((!(this_usbduxsub->ai_cmd_running)))) {
                /*
                 * not running a command, do not continue execution if no
                 * asynchronous command is running in particular not resubmit
                 */
                return;
        }

        urb->dev = this_usbduxsub->usbdev;

        /* resubmit the urb */
        err = usb_submit_urb(urb, GFP_ATOMIC);
        if (unlikely(err < 0)) {
                dev_err(&urb->dev->dev,
                        "comedi_: urb resubmit failed in int-context!"
                        "err=%d\n",
                        err);
                if (err == -EL2NSYNC)
                        dev_err(&urb->dev->dev,
                                "buggy USB host controller or bug in IRQ "
                                "handler!\n");
                s->async->events |= COMEDI_CB_EOA;
                s->async->events |= COMEDI_CB_ERROR;
                comedi_event(this_usbduxsub->comedidev, s);
                /* don't do an unlink here */
                usbdux_ai_stop(this_usbduxsub, 0);
                return;
        }

        /* get the state of the dio pins to allow external trigger */
        dio_state = be32_to_cpu(this_usbduxsub->inBuffer[0]);

        this_usbduxsub->ai_counter--;
        if (likely(this_usbduxsub->ai_counter > 0))
                return;

        /* timer zero, transfer measurements to comedi */
        this_usbduxsub->ai_counter = this_usbduxsub->ai_timer;

        /* test, if we transmit only a fixed number of samples */
        if (!(this_usbduxsub->ai_continuous)) {
                /* not continuous, fixed number of samples */
                this_usbduxsub->ai_sample_count--;
                /* all samples received? */
                if (this_usbduxsub->ai_sample_count < 0) {
                        /* prevent a resubmit next time */
                        usbdux_ai_stop(this_usbduxsub, 0);
                        /* say comedi that the acquistion is over */
                        s->async->events |= COMEDI_CB_EOA;
                        comedi_event(this_usbduxsub->comedidev, s);
                        return;
                }
        }
        /* get the data from the USB bus and hand it over to comedi */
        n = s->async->cmd.chanlist_len;
        for (i = 0; i < n; i++) {
                /* transfer data, note first byte is the DIO state */
                v = be32_to_cpu(this_usbduxsub->inBuffer[i+1]);
                /* strip status byte */
                v = v & 0x00ffffff;
                /* convert to unsigned */
                v = v ^ 0x00800000;
                /* write the byte to the buffer */
                err = cfc_write_array_to_buffer(s, &v, sizeof(uint32_t));
                if (unlikely(err == 0)) {
                        /* buffer overflow */
                        usbdux_ai_stop(this_usbduxsub, 0);
                        return;
                }
        }
        /* tell comedi that data is there */
        s->async->events |= COMEDI_CB_BLOCK | COMEDI_CB_EOS;
        comedi_event(this_usbduxsub->comedidev, s);
}

static int usbduxsub_unlink_OutURBs(struct usbduxsub *usbduxsub_tmp)
{
        int i = 0;
        int err = 0;

        if (usbduxsub_tmp && usbduxsub_tmp->urbOut) {
                for (i = 0; i < usbduxsub_tmp->numOfOutBuffers; i++) {
                        if (usbduxsub_tmp->urbOut[i])
                                usb_kill_urb(usbduxsub_tmp->urbOut[i]);

                        dev_dbg(&usbduxsub_tmp->interface->dev,
                                "comedi: usbdux: unlinked OutURB %d: res=%d\n",
                                i, err);
                }
        }
        return err;
}

/* This will cancel a running acquisition operation
 * in any context.
 */
static int usbdux_ao_stop(struct usbduxsub *this_usbduxsub, int do_unlink)
{
        int ret = 0;

        if (!this_usbduxsub)
                return -EFAULT;
        dev_dbg(&this_usbduxsub->interface->dev, "comedi: usbdux_ao_cancel\n");

        if (do_unlink)
                ret = usbduxsub_unlink_OutURBs(this_usbduxsub);

        this_usbduxsub->ao_cmd_running = 0;

        return ret;
}

/* force unlink, is called by comedi */
static int usbdux_ao_cancel(struct comedi_device *dev,
                            struct comedi_subdevice *s)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        int res = 0;

        if (!this_usbduxsub)
                return -EFAULT;

        /* prevent other CPUs from submitting a command just now */
        down(&this_usbduxsub->sem);
        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        /* unlink only if it is really running */
        res = usbdux_ao_stop(this_usbduxsub, this_usbduxsub->ao_cmd_running);
        up(&this_usbduxsub->sem);
        return res;
}

static void usbduxsub_ao_IsocIrq(struct urb *urb)
{
        int i, ret;
        uint8_t *datap;
        struct usbduxsub *this_usbduxsub;
        struct comedi_device *this_comedidev;
        struct comedi_subdevice *s;

        /* the context variable points to the subdevice */
        this_comedidev = urb->context;
        /* the private structure of the subdevice is struct usbduxsub */
        this_usbduxsub = this_comedidev->private;

        s = &this_comedidev->subdevices[SUBDEV_DA];

        switch (urb->status) {
        case 0:
                /* success */
                break;

        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
        case -ECONNABORTED:
                /* after an unlink command, unplug, ... etc */
                /* no unlink needed here. Already shutting down. */
                if (this_usbduxsub->ao_cmd_running) {
                        s->async->events |= COMEDI_CB_EOA;
                        comedi_event(this_usbduxsub->comedidev, s);
                        usbdux_ao_stop(this_usbduxsub, 0);
                }
                return;

        default:
                /* a real error */
                if (this_usbduxsub->ao_cmd_running) {
                        dev_err(&urb->dev->dev,
                                "comedi_: Non-zero urb status received in ao "
                                "intr context: %d\n", urb->status);
                        s->async->events |= COMEDI_CB_ERROR;
                        s->async->events |= COMEDI_CB_EOA;
                        comedi_event(this_usbduxsub->comedidev, s);
                        /* we do an unlink if we are in the high speed mode */
                        usbdux_ao_stop(this_usbduxsub, 0);
                }
                return;
        }

        /* are we actually running? */
        if (!(this_usbduxsub->ao_cmd_running))
                return;

        /* normal operation: executing a command in this subdevice */
        this_usbduxsub->ao_counter--;
        if ((int)this_usbduxsub->ao_counter <= 0) {
                /* timer zero */
                this_usbduxsub->ao_counter = this_usbduxsub->ao_timer;

                /* handle non continuous acquisition */
                if (!(this_usbduxsub->ao_continuous)) {
                        /* fixed number of samples */
                        this_usbduxsub->ao_sample_count--;
                        if (this_usbduxsub->ao_sample_count < 0) {
                                /* all samples transmitted */
                                usbdux_ao_stop(this_usbduxsub, 0);
                                s->async->events |= COMEDI_CB_EOA;
                                comedi_event(this_usbduxsub->comedidev, s);
                                /* no resubmit of the urb */
                                return;
                        }
                }
                /* transmit data to the USB bus */
                ((uint8_t *) (urb->transfer_buffer))[0] =
                    s->async->cmd.chanlist_len;
                for (i = 0; i < s->async->cmd.chanlist_len; i++) {
                        short temp;
                        if (i >= NUMOUTCHANNELS)
                                break;

                        /* pointer to the DA */
                        datap =
                            (&(((uint8_t *) urb->transfer_buffer)[i * 2 + 1]));
                        /* get the data from comedi */
                        ret = comedi_buf_get(s->async, &temp);
                        datap[0] = temp;
                        datap[1] = this_usbduxsub->dac_commands[i];
                        /* printk("data[0]=%x, data[1]=%x, data[2]=%x\n", */
                        /* datap[0],datap[1],datap[2]); */
                        if (ret < 0) {
                                dev_err(&urb->dev->dev,
                                        "comedi: buffer underflow\n");
                                s->async->events |= COMEDI_CB_EOA;
                                s->async->events |= COMEDI_CB_OVERFLOW;
                        }
                        /* transmit data to comedi */
                        s->async->events |= COMEDI_CB_BLOCK;
                        comedi_event(this_usbduxsub->comedidev, s);
                }
        }
        urb->transfer_buffer_length = SIZEOUTBUF;
        urb->dev = this_usbduxsub->usbdev;
        urb->status = 0;
        if (this_usbduxsub->ao_cmd_running) {
                if (this_usbduxsub->high_speed) {
                        /* uframes */
                        urb->interval = 8;
                } else {
                        /* frames */
                        urb->interval = 1;
                }
                urb->number_of_packets = 1;
                urb->iso_frame_desc[0].offset = 0;
                urb->iso_frame_desc[0].length = SIZEOUTBUF;
                urb->iso_frame_desc[0].status = 0;
                ret = usb_submit_urb(urb, GFP_ATOMIC);
                if (ret < 0) {
                        dev_err(&urb->dev->dev,
                                "comedi_: ao urb resubm failed in int-cont. "
                                "ret=%d", ret);
                        if (ret == EL2NSYNC)
                                dev_err(&urb->dev->dev,
                                        "buggy USB host controller or bug in "
                                        "IRQ handling!\n");

                        s->async->events |= COMEDI_CB_EOA;
                        s->async->events |= COMEDI_CB_ERROR;
                        comedi_event(this_usbduxsub->comedidev, s);
                        /* don't do an unlink here */
                        usbdux_ao_stop(this_usbduxsub, 0);
                }
        }
}

static int usbduxsub_start(struct usbduxsub *usbduxsub)
{
        int errcode = 0;
        uint8_t *local_transfer_buffer;

        local_transfer_buffer = kmalloc(16, GFP_KERNEL);
        if (!local_transfer_buffer)
                return -ENOMEM;

        /* 7f92 to zero */
        local_transfer_buffer[0] = 0;
        errcode = usb_control_msg(usbduxsub->usbdev,
                                  /* create a pipe for a control transfer */
                                  usb_sndctrlpipe(usbduxsub->usbdev, 0),
                                  /* bRequest, "Firmware" */
                                  USBDUXSUB_FIRMWARE,
                                  /* bmRequestType */
                                  VENDOR_DIR_OUT,
                                  /* Value */
                                  USBDUXSUB_CPUCS,
                                  /* Index */
                                  0x0000,
                                  /* address of the transfer buffer */
                                  local_transfer_buffer,
                                  /* Length */
                                  1,
                                  /* Timeout */
                                  BULK_TIMEOUT);
        if (errcode < 0)
                dev_err(&usbduxsub->interface->dev,
                        "comedi_: control msg failed (start)\n");

        kfree(local_transfer_buffer);
        return errcode;
}

static int usbduxsub_stop(struct usbduxsub *usbduxsub)
{
        int errcode = 0;
        uint8_t *local_transfer_buffer;

        local_transfer_buffer = kmalloc(16, GFP_KERNEL);
        if (!local_transfer_buffer)
                return -ENOMEM;

        /* 7f92 to one */
        local_transfer_buffer[0] = 1;
        errcode = usb_control_msg(usbduxsub->usbdev,
                                  usb_sndctrlpipe(usbduxsub->usbdev, 0),
                                  /* bRequest, "Firmware" */
                                  USBDUXSUB_FIRMWARE,
                                  /* bmRequestType */
                                  VENDOR_DIR_OUT,
                                  /* Value */
                                  USBDUXSUB_CPUCS,
                                  /* Index */
                                  0x0000, local_transfer_buffer,
                                  /* Length */
                                  1,
                                  /* Timeout */
                                  BULK_TIMEOUT);
        if (errcode < 0)
                dev_err(&usbduxsub->interface->dev,
                        "comedi_: control msg failed (stop)\n");

        kfree(local_transfer_buffer);
        return errcode;
}

static int usbduxsub_upload(struct usbduxsub *usbduxsub,
                            uint8_t *local_transfer_buffer,
                            unsigned int startAddr, unsigned int len)
{
        int errcode;

        errcode = usb_control_msg(usbduxsub->usbdev,
                                  usb_sndctrlpipe(usbduxsub->usbdev, 0),
                                  /* brequest, firmware */
                                  USBDUXSUB_FIRMWARE,
                                  /* bmRequestType */
                                  VENDOR_DIR_OUT,
                                  /* value */
                                  startAddr,
                                  /* index */
                                  0x0000,
                                  /* our local safe buffer */
                                  local_transfer_buffer,
                                  /* length */
                                  len,
                                  /* timeout */
                                  BULK_TIMEOUT);
        dev_dbg(&usbduxsub->interface->dev, "comedi_: result=%d\n", errcode);
        if (errcode < 0) {
                dev_err(&usbduxsub->interface->dev,
                        "comedi_: upload failed\n");
                return errcode;
        }
        return 0;
}

/* the FX2LP has twice as much as the standard FX2 */
#define FIRMWARE_MAX_LEN 0x4000

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

        if (!firmwareBinary)
                return 0;

        if (sizeFirmware > FIRMWARE_MAX_LEN) {
                dev_err(&usbduxsub->interface->dev,
                        "usbduxsigma 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(&usbduxsub->interface->dev,
                        "comedi_: mem alloc for firmware failed\n");
                return -ENOMEM;
        }

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

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

static int usbduxsub_submit_InURBs(struct usbduxsub *usbduxsub)
{
        int i, errFlag;

        if (!usbduxsub)
                return -EFAULT;

        /* Submit all URBs and start the transfer on the bus */
        for (i = 0; i < usbduxsub->numOfInBuffers; i++) {
                /* in case of a resubmission after an unlink... */
                usbduxsub->urbIn[i]->interval = usbduxsub->ai_interval;
                usbduxsub->urbIn[i]->context = usbduxsub->comedidev;
                usbduxsub->urbIn[i]->dev = usbduxsub->usbdev;
                usbduxsub->urbIn[i]->status = 0;
                usbduxsub->urbIn[i]->transfer_flags = URB_ISO_ASAP;
                dev_dbg(&usbduxsub->interface->dev,
                        "comedi%d: submitting in-urb[%d]: %p,%p intv=%d\n",
                        usbduxsub->comedidev->minor, i,
                        (usbduxsub->urbIn[i]->context),
                        (usbduxsub->urbIn[i]->dev),
                        (usbduxsub->urbIn[i]->interval));
                errFlag = usb_submit_urb(usbduxsub->urbIn[i], GFP_ATOMIC);
                if (errFlag) {
                        dev_err(&usbduxsub->interface->dev,
                                "comedi_: ai: usb_submit_urb(%d) error %d\n",
                                i, errFlag);
                        return errFlag;
                }
        }
        return 0;
}

static int usbduxsub_submit_OutURBs(struct usbduxsub *usbduxsub)
{
        int i, errFlag;

        if (!usbduxsub)
                return -EFAULT;

        for (i = 0; i < usbduxsub->numOfOutBuffers; i++) {
                dev_dbg(&usbduxsub->interface->dev,
                        "comedi_: submitting out-urb[%d]\n", i);
                /* in case of a resubmission after an unlink... */
                usbduxsub->urbOut[i]->context = usbduxsub->comedidev;
                usbduxsub->urbOut[i]->dev = usbduxsub->usbdev;
                usbduxsub->urbOut[i]->status = 0;
                usbduxsub->urbOut[i]->transfer_flags = URB_ISO_ASAP;
                errFlag = usb_submit_urb(usbduxsub->urbOut[i], GFP_ATOMIC);
                if (errFlag) {
                        dev_err(&usbduxsub->interface->dev,
                                "comedi_: ao: usb_submit_urb(%d) error %d\n",
                                i, errFlag);
                        return errFlag;
                }
        }
        return 0;
}

static int chanToInterval(int nChannels)
{
        if (nChannels <= 2)
                /* 4kHz */
                return 2;
        if (nChannels <= 8)
                /* 2kHz */
                return 4;
        /* 1kHz */
        return 8;
}

static int usbdux_ai_cmdtest(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             struct comedi_cmd *cmd)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        int err = 0, i;
        unsigned int tmpTimer;

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

        /* Step 1 : check if triggers are trivially valid */

        err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);
        err |= cfc_check_trigger_src(&cmd->scan_begin_src, TRIG_TIMER);
        err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
        err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
        err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);

        if (err)
                return 1;

        /* Step 2a : make sure trigger sources are unique */

        err |= cfc_check_trigger_is_unique(cmd->start_src);
        err |= cfc_check_trigger_is_unique(cmd->stop_src);

        /* Step 2b : and mutually compatible */

        if (err)
                return 2;

        /* Step 3: check if arguments are trivially valid */

        err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);

        if (cmd->scan_begin_src == TRIG_FOLLOW) /* internal trigger */
                err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);

        if (cmd->scan_begin_src == TRIG_TIMER) {
                if (this_usbduxsub->high_speed) {
                        /*
                         * In high speed mode microframes are possible.
                         * However, during one microframe we can roughly
                         * sample two channels. Thus, the more channels
                         * are in the channel list the more time we need.
                         */
                        i = chanToInterval(cmd->chanlist_len);
                        err |= cfc_check_trigger_arg_min(&cmd->scan_begin_arg,
                                                         (1000000 / 8 * i));
                        /* now calc the real sampling rate with all the
                         * rounding errors */
                        tmpTimer =
                            ((unsigned int)(cmd->scan_begin_arg / 125000)) *
                            125000;
                } else {
                        /* full speed */
                        /* 1kHz scans every USB frame */
                        err |= cfc_check_trigger_arg_min(&cmd->scan_begin_arg,
                                                         1000000);
                        /*
                         * calc the real sampling rate with the rounding errors
                         */
                        tmpTimer = ((unsigned int)(cmd->scan_begin_arg /
                                                   1000000)) * 1000000;
                }
                err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg,
                                                tmpTimer);
        }

        err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);

        if (cmd->stop_src == TRIG_COUNT) {
                /* any count is allowed */
        } else {
                /* TRIG_NONE */
                err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
        }

        if (err)
                return 3;

        return 0;
}

/*
 * creates the ADC command for the MAX1271
 * range is the range value from comedi
 */
static void create_adc_command(unsigned int chan,
                               uint8_t *muxsg0,
                               uint8_t *muxsg1)
{
        if (chan < 8)
                (*muxsg0) = (*muxsg0) | (1 << chan);
        else if (chan < 16)
                (*muxsg1) = (*muxsg1) | (1 << (chan-8));
}


/* bulk transfers to usbdux */

#define SENDADCOMMANDS            0
#define SENDDACOMMANDS            1

#define SENDDIOCONFIGCOMMAND      2
#define SENDDIOBITSCOMMAND        3
#define SENDSINGLEAD              4
#define SENDPWMON                 7
#define SENDPWMOFF                8

static int send_dux_commands(struct usbduxsub *this_usbduxsub, int cmd_type)
{
        int result, nsent;

        this_usbduxsub->dux_commands[0] = cmd_type;
#ifdef NOISY_DUX_DEBUGBUG
        printk(KERN_DEBUG "comedi%d: usbdux: dux_commands: ",
               this_usbduxsub->comedidev->minor);
        for (result = 0; result < SIZEOFDUXBUFFER; result++)
                printk(" %02x", this_usbduxsub->dux_commands[result]);
        printk("\n");
#endif
        result = usb_bulk_msg(this_usbduxsub->usbdev,
                              usb_sndbulkpipe(this_usbduxsub->usbdev,
                                              COMMAND_OUT_EP),
                              this_usbduxsub->dux_commands, SIZEOFDUXBUFFER,
                              &nsent, BULK_TIMEOUT);
        if (result < 0)
                dev_err(&this_usbduxsub->interface->dev, "comedi%d: "
                        "could not transmit dux_command to the usb-device, "
                        "err=%d\n", this_usbduxsub->comedidev->minor, result);

        return result;
}

static int receive_dux_commands(struct usbduxsub *this_usbduxsub, int command)
{
        int result = (-EFAULT);
        int nrec;
        int i;

        for (i = 0; i < RETRIES; i++) {
                result = usb_bulk_msg(this_usbduxsub->usbdev,
                                      usb_rcvbulkpipe(this_usbduxsub->usbdev,
                                                      COMMAND_IN_EP),
                                      this_usbduxsub->insnBuffer, SIZEINSNBUF,
                                      &nrec, BULK_TIMEOUT);
                if (result < 0) {
                        dev_err(&this_usbduxsub->interface->dev, "comedi%d: "
                                "insn: USB error %d "
                                "while receiving DUX command"
                                "\n", this_usbduxsub->comedidev->minor,
                                result);
                        return result;
                }
                if (this_usbduxsub->insnBuffer[0] == command)
                        return result;
        }
        /* this is only reached if the data has been requested a couple of
         * times */
        dev_err(&this_usbduxsub->interface->dev, "comedi%d: insn: "
                "wrong data returned from firmware: want %d, got %d.\n",
                this_usbduxsub->comedidev->minor, command,
                this_usbduxsub->insnBuffer[0]);
        return -EFAULT;
}

static int usbdux_ai_inttrig(struct comedi_device *dev,
                             struct comedi_subdevice *s, unsigned int trignum)
{
        int ret;
        struct usbduxsub *this_usbduxsub = dev->private;
        if (!this_usbduxsub)
                return -EFAULT;

        down(&this_usbduxsub->sem);
        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi%d: usbdux_ai_inttrig\n", dev->minor);

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

static int usbdux_ai_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
        struct comedi_cmd *cmd = &s->async->cmd;
        unsigned int chan;
        int i, ret;
        struct usbduxsub *this_usbduxsub = dev->private;
        int result;
        uint8_t muxsg0 = 0;
        uint8_t muxsg1 = 0;
        uint8_t sysred = 0;

        if (!this_usbduxsub)
                return -EFAULT;

        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi%d: usbdux_ai_cmd\n", dev->minor);

        /* block other CPUs from starting an ai_cmd */
        down(&this_usbduxsub->sem);

        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        if (this_usbduxsub->ai_cmd_running) {
                dev_err(&this_usbduxsub->interface->dev, "comedi%d: "
                        "ai_cmd not possible. Another ai_cmd is running.\n",
                        dev->minor);
                up(&this_usbduxsub->sem);
                return -EBUSY;
        }
        /* set current channel of the running acquisition to zero */
        s->async->cur_chan = 0;

        /* first the number of channels per time step */
        this_usbduxsub->dux_commands[1] = cmd->chanlist_len;

        /* CONFIG0 */
        this_usbduxsub->dux_commands[2] = 0x12;

        /* CONFIG1: 23kHz sampling rate, delay = 0us,  */
        this_usbduxsub->dux_commands[3] = 0x03;

        /* CONFIG3: differential channels off */
        this_usbduxsub->dux_commands[4] = 0x00;

        for (i = 0; i < cmd->chanlist_len; i++) {
                chan = CR_CHAN(cmd->chanlist[i]);
                create_adc_command(chan, &muxsg0, &muxsg1);
                if (i >= NUMCHANNELS) {
                        dev_err(&this_usbduxsub->interface->dev,
                                "comedi%d: channel list too long\n",
                                dev->minor);
                        break;
                }
        }
        this_usbduxsub->dux_commands[5] = muxsg0;
        this_usbduxsub->dux_commands[6] = muxsg1;
        this_usbduxsub->dux_commands[7] = sysred;

        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi %d: sending commands to the usb device: size=%u\n",
                dev->minor, NUMCHANNELS);

        result = send_dux_commands(this_usbduxsub, SENDADCOMMANDS);
        if (result < 0) {
                up(&this_usbduxsub->sem);
                return result;
        }

        if (this_usbduxsub->high_speed) {
                /*
                 * every 2 channels get a time window of 125us. Thus, if we
                 * sample all 16 channels we need 1ms. If we sample only one
                 * channel we need only 125us
                 */
                this_usbduxsub->ai_interval =
                        chanToInterval(cmd->chanlist_len);
                this_usbduxsub->ai_timer = cmd->scan_begin_arg / (125000 *
                                                          (this_usbduxsub->
                                                           ai_interval));
        } else {
                /* interval always 1ms */
                this_usbduxsub->ai_interval = 1;
                this_usbduxsub->ai_timer = cmd->scan_begin_arg / 1000000;
        }
        if (this_usbduxsub->ai_timer < 1) {
                dev_err(&this_usbduxsub->interface->dev, "comedi%d: ai_cmd: "
                        "timer=%d, scan_begin_arg=%d. "
                        "Not properly tested by cmdtest?\n", dev->minor,
                        this_usbduxsub->ai_timer, cmd->scan_begin_arg);
                up(&this_usbduxsub->sem);
                return -EINVAL;
        }
        this_usbduxsub->ai_counter = this_usbduxsub->ai_timer;

        if (cmd->stop_src == TRIG_COUNT) {
                /* data arrives as one packet */
                this_usbduxsub->ai_sample_count = cmd->stop_arg;
                this_usbduxsub->ai_continuous = 0;
        } else {
                /* continuous acquisition */
                this_usbduxsub->ai_continuous = 1;
                this_usbduxsub->ai_sample_count = 0;
        }

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

/* Mode 0 is used to get a single conversion on demand */
static int usbdux_ai_insn_read(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn, unsigned int *data)
{
        int i;
        int32_t one = 0;
        int chan;
        int err;
        struct usbduxsub *this_usbduxsub = dev->private;
        uint8_t muxsg0 = 0;
        uint8_t muxsg1 = 0;
        uint8_t sysred = 0;

        if (!this_usbduxsub)
                return 0;

        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi%d: ai_insn_read, insn->n=%d, insn->subdev=%d\n",
                dev->minor, insn->n, insn->subdev);

        down(&this_usbduxsub->sem);
        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        if (this_usbduxsub->ai_cmd_running) {
                dev_err(&this_usbduxsub->interface->dev,
                        "comedi%d: ai_insn_read not possible. "
                        "Async Command is running.\n", dev->minor);
                up(&this_usbduxsub->sem);
                return 0;
        }

        /* sample one channel */
        /* CONFIG0: chopper on */
        this_usbduxsub->dux_commands[1] = 0x16;

        /* CONFIG1: 2kHz sampling rate */
        this_usbduxsub->dux_commands[2] = 0x80;

        /* CONFIG3: differential channels off */
        this_usbduxsub->dux_commands[3] = 0x00;

        chan = CR_CHAN(insn->chanspec);
        create_adc_command(chan, &muxsg0, &muxsg1);

        this_usbduxsub->dux_commands[4] = muxsg0;
        this_usbduxsub->dux_commands[5] = muxsg1;
        this_usbduxsub->dux_commands[6] = sysred;

        /* adc commands */
        err = send_dux_commands(this_usbduxsub, SENDSINGLEAD);
        if (err < 0) {
                up(&this_usbduxsub->sem);
                return err;
        }

        for (i = 0; i < insn->n; i++) {
                err = receive_dux_commands(this_usbduxsub, SENDSINGLEAD);
                if (err < 0) {
                        up(&this_usbduxsub->sem);
                        return 0;
                }
                /* 32 bits big endian from the A/D converter */
                one = be32_to_cpu(*((int32_t *)
                                    ((this_usbduxsub->insnBuffer)+1)));
                /* mask out the status byte */
                one = one & 0x00ffffff;
                /* turn it into an unsigned integer */
                one = one ^ 0x00800000;
                data[i] = one;
        }
        up(&this_usbduxsub->sem);
        return i;
}




static int usbdux_getstatusinfo(struct comedi_device *dev, int chan)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        uint8_t sysred = 0;
        uint32_t one;
        int err;

        if (!this_usbduxsub)
                return 0;

        if (this_usbduxsub->ai_cmd_running) {
                dev_err(&this_usbduxsub->interface->dev,
                        "comedi%d: status read not possible. "
                        "Async Command is running.\n", dev->minor);
                return 0;
        }

        /* CONFIG0 */
        this_usbduxsub->dux_commands[1] = 0x12;

        /* CONFIG1: 2kHz sampling rate */
        this_usbduxsub->dux_commands[2] = 0x80;

        /* CONFIG3: differential channels off */
        this_usbduxsub->dux_commands[3] = 0x00;

        if (chan == 1) {
                /* ADC offset */
                sysred = sysred | 1;
        } else if (chan == 2) {
                /* VCC */
                sysred = sysred | 4;
        } else if (chan == 3) {
                /* temperature */
                sysred = sysred | 8;
        } else if (chan == 4) {
                /* gain */
                sysred = sysred | 16;
        } else if (chan == 5) {
                /* ref */
                sysred = sysred | 32;
        }

        this_usbduxsub->dux_commands[4] = 0;
        this_usbduxsub->dux_commands[5] = 0;
        this_usbduxsub->dux_commands[6] = sysred;

        /* adc commands */
        err = send_dux_commands(this_usbduxsub, SENDSINGLEAD);
        if (err < 0)
                return err;

        err = receive_dux_commands(this_usbduxsub, SENDSINGLEAD);
        if (err < 0)
                return err;

        /* 32 bits big endian from the A/D converter */
        one = be32_to_cpu(*((int32_t *)((this_usbduxsub->insnBuffer)+1)));
        /* mask out the status byte */
        one = one & 0x00ffffff;
        one = one ^ 0x00800000;

        return (int)one;
}






/************************************/
/* analog out */

static int usbdux_ao_insn_read(struct comedi_device *dev,
                               struct comedi_subdevice *s,
                               struct comedi_insn *insn, unsigned int *data)
{
        int i;
        int chan = CR_CHAN(insn->chanspec);
        struct usbduxsub *this_usbduxsub = dev->private;

        if (!this_usbduxsub)
                return -EFAULT;

        down(&this_usbduxsub->sem);
        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        for (i = 0; i < insn->n; i++)
                data[i] = this_usbduxsub->outBuffer[chan];

        up(&this_usbduxsub->sem);
        return i;
}

static int usbdux_ao_insn_write(struct comedi_device *dev,
                                struct comedi_subdevice *s,
                                struct comedi_insn *insn, unsigned int *data)
{
        int i, err;
        int chan = CR_CHAN(insn->chanspec);
        struct usbduxsub *this_usbduxsub = dev->private;

        if (!this_usbduxsub)
                return -EFAULT;

        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi%d: ao_insn_write\n", dev->minor);

        down(&this_usbduxsub->sem);
        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        if (this_usbduxsub->ao_cmd_running) {
                dev_err(&this_usbduxsub->interface->dev,
                        "comedi%d: ao_insn_write: "
                        "ERROR: asynchronous ao_cmd is running\n", dev->minor);
                up(&this_usbduxsub->sem);
                return 0;
        }

        for (i = 0; i < insn->n; i++) {
                dev_dbg(&this_usbduxsub->interface->dev,
                        "comedi%d: ao_insn_write: data[chan=%d,i=%d]=%d\n",
                        dev->minor, chan, i, data[i]);

                /* number of channels: 1 */
                this_usbduxsub->dux_commands[1] = 1;
                /* channel number */
                this_usbduxsub->dux_commands[2] = data[i];
                this_usbduxsub->outBuffer[chan] = data[i];
                this_usbduxsub->dux_commands[3] = chan;
                err = send_dux_commands(this_usbduxsub, SENDDACOMMANDS);
                if (err < 0) {
                        up(&this_usbduxsub->sem);
                        return err;
                }
        }
        up(&this_usbduxsub->sem);

        return i;
}

static int usbdux_ao_inttrig(struct comedi_device *dev,
                             struct comedi_subdevice *s, unsigned int trignum)
{
        int ret;
        struct usbduxsub *this_usbduxsub = dev->private;

        if (!this_usbduxsub)
                return -EFAULT;

        down(&this_usbduxsub->sem);

        if (!(this_usbduxsub->probed)) {
                ret = -ENODEV;
                goto out;
        }
        if (trignum != 0) {
                dev_err(&this_usbduxsub->interface->dev,
                        "comedi%d: usbdux_ao_inttrig: invalid trignum\n",
                        dev->minor);
                ret = -EINVAL;
                goto out;
        }
        if (!(this_usbduxsub->ao_cmd_running)) {
                this_usbduxsub->ao_cmd_running = 1;
                ret = usbduxsub_submit_OutURBs(this_usbduxsub);
                if (ret < 0) {
                        dev_err(&this_usbduxsub->interface->dev,
                                "comedi%d: usbdux_ao_inttrig: submitURB: "
                                "err=%d\n", dev->minor, ret);
                        this_usbduxsub->ao_cmd_running = 0;
                        goto out;
                }
                s->async->inttrig = NULL;
        } else {
                dev_err(&this_usbduxsub->interface->dev,
                        "comedi%d: ao_inttrig but acqu is already running.\n",
                        dev->minor);
        }
        ret = 1;
out:
        up(&this_usbduxsub->sem);
        return ret;
}

static int usbdux_ao_cmdtest(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             struct comedi_cmd *cmd)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        int err = 0;
        unsigned int flags;

        if (!this_usbduxsub)
                return -EFAULT;

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

        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi%d: usbdux_ao_cmdtest\n", dev->minor);

        /* Step 1 : check if triggers are trivially valid */

        err |= cfc_check_trigger_src(&cmd->start_src, TRIG_NOW | TRIG_INT);

        if (0) {                /* (this_usbduxsub->high_speed) */
                /*
                 * start immediately a new scan
                 * the sampling rate is set by the coversion rate
                 */
                flags = TRIG_FOLLOW;
        } else {
                /* start a new scan (output at once) with a timer */
                flags = TRIG_TIMER;
        }
        err |= cfc_check_trigger_src(&cmd->scan_begin_src, flags);

        err |= cfc_check_trigger_src(&cmd->convert_src, TRIG_NOW);
        err |= cfc_check_trigger_src(&cmd->scan_end_src, TRIG_COUNT);
        err |= cfc_check_trigger_src(&cmd->stop_src, TRIG_COUNT | TRIG_NONE);

        if (err)
                return 1;

        /* Step 2a : make sure trigger sources are unique */

        err |= cfc_check_trigger_is_unique(cmd->start_src);
        err |= cfc_check_trigger_is_unique(cmd->stop_src);

        /* Step 2b : and mutually compatible */

        if (err)
                return 2;

        /* Step 3: check if arguments are trivially valid */

        err |= cfc_check_trigger_arg_is(&cmd->start_arg, 0);

        if (cmd->scan_begin_src == TRIG_FOLLOW) /* internal trigger */
                err |= cfc_check_trigger_arg_is(&cmd->scan_begin_arg, 0);

        if (cmd->scan_begin_src == TRIG_TIMER)
                err |= cfc_check_trigger_arg_min(&cmd->scan_begin_arg,
                                                 1000000);

        /* not used now, is for later use */
        if (cmd->convert_src == TRIG_TIMER)
                err |= cfc_check_trigger_arg_min(&cmd->convert_arg, 125000);

        err |= cfc_check_trigger_arg_is(&cmd->scan_end_arg, cmd->chanlist_len);

        if (cmd->stop_src == TRIG_COUNT) {
                /* any count is allowed */
        } else {
                /* TRIG_NONE */
                err |= cfc_check_trigger_arg_is(&cmd->stop_arg, 0);
        }

        if (err)
                return 3;

        return 0;
}

static int usbdux_ao_cmd(struct comedi_device *dev, struct comedi_subdevice *s)
{
        struct comedi_cmd *cmd = &s->async->cmd;
        unsigned int chan, gain;
        int i, ret;
        struct usbduxsub *this_usbduxsub = dev->private;

        if (!this_usbduxsub)
                return -EFAULT;

        down(&this_usbduxsub->sem);
        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }
        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi%d: %s\n", dev->minor, __func__);

        /* set current channel of the running acquisition to zero */
        s->async->cur_chan = 0;
        for (i = 0; i < cmd->chanlist_len; ++i) {
                chan = CR_CHAN(cmd->chanlist[i]);
                gain = CR_RANGE(cmd->chanlist[i]);
                if (i >= NUMOUTCHANNELS) {
                        dev_err(&this_usbduxsub->interface->dev,
                                "comedi%d: %s: channel list too long\n",
                                dev->minor, __func__);
                        break;
                }
                this_usbduxsub->dac_commands[i] = chan;
                dev_dbg(&this_usbduxsub->interface->dev,
                        "comedi%d: dac command for ch %d is %x\n",
                        dev->minor, i, this_usbduxsub->dac_commands[i]);
        }

        /* we count in steps of 1ms (125us) */
        /* 125us mode not used yet */
        if (0) {                /* (this_usbduxsub->high_speed) */
                /* 125us */
                /* timing of the conversion itself: every 125 us */
                this_usbduxsub->ao_timer = cmd->convert_arg / 125000;
        } else {
                /* 1ms */
                /* timing of the scan: we get all channels at once */
                this_usbduxsub->ao_timer = cmd->scan_begin_arg / 1000000;
                dev_dbg(&this_usbduxsub->interface->dev,
                        "comedi%d: scan_begin_src=%d, scan_begin_arg=%d, "
                        "convert_src=%d, convert_arg=%d\n", dev->minor,
                        cmd->scan_begin_src, cmd->scan_begin_arg,
                        cmd->convert_src, cmd->convert_arg);
                dev_dbg(&this_usbduxsub->interface->dev,
                        "comedi%d: ao_timer=%d (ms)\n",
                        dev->minor, this_usbduxsub->ao_timer);
                if (this_usbduxsub->ao_timer < 1) {
                        dev_err(&this_usbduxsub->interface->dev,
                                "comedi%d: usbdux: ao_timer=%d, "
                                "scan_begin_arg=%d. "
                                "Not properly tested by cmdtest?\n",
                                dev->minor, this_usbduxsub->ao_timer,
                                cmd->scan_begin_arg);
                        up(&this_usbduxsub->sem);
                        return -EINVAL;
                }
        }
        this_usbduxsub->ao_counter = this_usbduxsub->ao_timer;

        if (cmd->stop_src == TRIG_COUNT) {
                /* not continuous */
                /* counter */
                /* high speed also scans everything at once */
                if (0) {        /* (this_usbduxsub->high_speed) */
                        this_usbduxsub->ao_sample_count =
                            (cmd->stop_arg) * (cmd->scan_end_arg);
                } else {
                        /* there's no scan as the scan has been */
                        /* perf inside the FX2 */
                        /* data arrives as one packet */
                        this_usbduxsub->ao_sample_count = cmd->stop_arg;
                }
                this_usbduxsub->ao_continuous = 0;
        } else {
                /* continuous acquisition */
                this_usbduxsub->ao_continuous = 1;
                this_usbduxsub->ao_sample_count = 0;
        }

        if (cmd->start_src == TRIG_NOW) {
                /* enable this acquisition operation */
                this_usbduxsub->ao_cmd_running = 1;
                ret = usbduxsub_submit_OutURBs(this_usbduxsub);
                if (ret < 0) {
                        this_usbduxsub->ao_cmd_running = 0;
                        /* fixme: unlink here?? */
                        up(&this_usbduxsub->sem);
                        return ret;
                }
                s->async->inttrig = NULL;
        } else {
                /* TRIG_INT */
                /* submit the urbs later */
                /* wait for an internal signal */
                s->async->inttrig = usbdux_ao_inttrig;
        }

        up(&this_usbduxsub->sem);
        return 0;
}

static int usbdux_dio_insn_config(struct comedi_device *dev,
                                  struct comedi_subdevice *s,
                                  struct comedi_insn *insn, unsigned int *data)
{
        int chan = CR_CHAN(insn->chanspec);

        /* The input or output configuration of each digital line is
         * configured by a special insn_config instruction.  chanspec
         * contains the channel to be changed, and data[0] contains the
         * value COMEDI_INPUT or COMEDI_OUTPUT. */

        switch (data[0]) {
        case INSN_CONFIG_DIO_OUTPUT:
                s->io_bits |= 1 << chan;        /* 1 means Out */
                break;
        case INSN_CONFIG_DIO_INPUT:
                s->io_bits &= ~(1 << chan);
                break;
        case INSN_CONFIG_DIO_QUERY:
                data[1] =
                    (s->io_bits & (1 << chan)) ? COMEDI_OUTPUT : COMEDI_INPUT;
                break;
        default:
                return -EINVAL;
                break;
        }
        /* we don't tell the firmware here as it would take 8 frames */
        /* to submit the information. We do it in the insn_bits. */
        return insn->n;
}

static int usbdux_dio_insn_bits(struct comedi_device *dev,
                                struct comedi_subdevice *s,
                                struct comedi_insn *insn,
                                unsigned int *data)
{

        struct usbduxsub *this_usbduxsub = dev->private;
        int err;

        if (!this_usbduxsub)
                return -EFAULT;

        down(&this_usbduxsub->sem);

        if (!(this_usbduxsub->probed)) {
                up(&this_usbduxsub->sem);
                return -ENODEV;
        }

        /* The insn data is a mask in data[0] and the new data
         * in data[1], each channel cooresponding to a bit. */
        s->state &= ~data[0];
        s->state |= data[0] & data[1];
        /* The commands are 8 bits wide */
        this_usbduxsub->dux_commands[1] = (s->io_bits) & 0x000000FF;
        this_usbduxsub->dux_commands[4] = (s->state) & 0x000000FF;
        this_usbduxsub->dux_commands[2] = ((s->io_bits) & 0x0000FF00) >> 8;
        this_usbduxsub->dux_commands[5] = ((s->state) & 0x0000FF00) >> 8;
        this_usbduxsub->dux_commands[3] = ((s->io_bits) & 0x00FF0000) >> 16;
        this_usbduxsub->dux_commands[6] = ((s->state) & 0x00FF0000) >> 16;

        /* This command also tells the firmware to return */
        /* the digital input lines */
        err = send_dux_commands(this_usbduxsub, SENDDIOBITSCOMMAND);
        if (err < 0) {
                up(&this_usbduxsub->sem);
                return err;
        }
        err = receive_dux_commands(this_usbduxsub, SENDDIOBITSCOMMAND);
        if (err < 0) {
                up(&this_usbduxsub->sem);
                return err;
        }

        data[1] = (((unsigned int)(this_usbduxsub->insnBuffer[1]))&0xff) |
                ((((unsigned int)(this_usbduxsub->insnBuffer[2]))&0xff) << 8) |
                ((((unsigned int)(this_usbduxsub->insnBuffer[3]))&0xff) << 16);

        s->state = data[1];

        up(&this_usbduxsub->sem);
        return insn->n;
}

/***********************************/
/* PWM */

static int usbduxsub_unlink_PwmURBs(struct usbduxsub *usbduxsub_tmp)
{
        int err = 0;

        if (usbduxsub_tmp && usbduxsub_tmp->urbPwm) {
                if (usbduxsub_tmp->urbPwm)
                        usb_kill_urb(usbduxsub_tmp->urbPwm);
                dev_dbg(&usbduxsub_tmp->interface->dev,
                        "comedi: unlinked PwmURB: res=%d\n", err);
        }
        return err;
}

/* This cancels a running acquisition operation
 * in any context.
 */
static int usbdux_pwm_stop(struct usbduxsub *this_usbduxsub, int do_unlink)
{
        int ret = 0;

        if (!this_usbduxsub)
                return -EFAULT;

        dev_dbg(&this_usbduxsub->interface->dev, "comedi: %s\n", __func__);
        if (do_unlink)
                ret = usbduxsub_unlink_PwmURBs(this_usbduxsub);

        this_usbduxsub->pwm_cmd_running = 0;

        return ret;
}

/* force unlink - is called by comedi */
static int usbdux_pwm_cancel(struct comedi_device *dev,
                             struct comedi_subdevice *s)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        int res = 0;

        /* unlink only if it is really running */
        res = usbdux_pwm_stop(this_usbduxsub, this_usbduxsub->pwm_cmd_running);

        dev_dbg(&this_usbduxsub->interface->dev,
                "comedi %d: sending pwm off command to the usb device.\n",
                dev->minor);
        res = send_dux_commands(this_usbduxsub, SENDPWMOFF);
        if (res < 0)
                return res;

        return res;
}

static void usbduxsub_pwm_irq(struct urb *urb)
{
        int ret;
        struct usbduxsub *this_usbduxsub;
        struct comedi_device *this_comedidev;
        struct comedi_subdevice *s;

        /* printk(KERN_DEBUG "PWM: IRQ\n"); */

        /* the context variable points to the subdevice */
        this_comedidev = urb->context;
        /* the private structure of the subdevice is struct usbduxsub */
        this_usbduxsub = this_comedidev->private;

        s = &this_comedidev->subdevices[SUBDEV_DA];

        switch (urb->status) {
        case 0:
                /* success */
                break;

        case -ECONNRESET:
        case -ENOENT:
        case -ESHUTDOWN:
        case -ECONNABORTED:
                /*
                 * after an unlink command, unplug, ... etc
                 * no unlink needed here. Already shutting down.
                 */
                if (this_usbduxsub->pwm_cmd_running)
                        usbdux_pwm_stop(this_usbduxsub, 0);

                return;

        default:
                /* a real error */
                if (this_usbduxsub->pwm_cmd_running) {
                        dev_err(&this_usbduxsub->interface->dev,
                                "comedi_: Non-zero urb status received in "
                                "pwm intr context: %d\n", urb->status);
                        usbdux_pwm_stop(this_usbduxsub, 0);
                }
                return;
        }

        /* are we actually running? */
        if (!(this_usbduxsub->pwm_cmd_running))
                return;

        urb->transfer_buffer_length = this_usbduxsub->sizePwmBuf;
        urb->dev = this_usbduxsub->usbdev;
        urb->status = 0;
        if (this_usbduxsub->pwm_cmd_running) {
                ret = usb_submit_urb(urb, GFP_ATOMIC);
                if (ret < 0) {
                        dev_err(&this_usbduxsub->interface->dev,
                                "comedi_: pwm urb resubm failed in int-cont. "
                                "ret=%d", ret);
                        if (ret == EL2NSYNC)
                                dev_err(&this_usbduxsub->interface->dev,
                                        "buggy USB host controller or bug in "
                                        "IRQ handling!\n");

                        /* don't do an unlink here */
                        usbdux_pwm_stop(this_usbduxsub, 0);
                }
        }
}

static int usbduxsub_submit_PwmURBs(struct usbduxsub *usbduxsub)
{
        int errFlag;

        if (!usbduxsub)
                return -EFAULT;

        dev_dbg(&usbduxsub->interface->dev, "comedi_: submitting pwm-urb\n");

        /* in case of a resubmission after an unlink... */
        usb_fill_bulk_urb(usbduxsub->urbPwm,
                          usbduxsub->usbdev,
                          usb_sndbulkpipe(usbduxsub->usbdev, PWM_EP),
                          usbduxsub->urbPwm->transfer_buffer,
                          usbduxsub->sizePwmBuf, usbduxsub_pwm_irq,
                          usbduxsub->comedidev);

        errFlag = usb_submit_urb(usbduxsub->urbPwm, GFP_ATOMIC);
        if (errFlag) {
                dev_err(&usbduxsub->interface->dev,
                        "comedi_: usbduxsigma: pwm: usb_submit_urb error %d\n",
                        errFlag);
                return errFlag;
        }
        return 0;
}

static int usbdux_pwm_period(struct comedi_device *dev,
                             struct comedi_subdevice *s, unsigned int period)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        int fx2delay = 255;

        if (period < MIN_PWM_PERIOD) {
                dev_err(&this_usbduxsub->interface->dev,
                        "comedi%d: illegal period setting for pwm.\n",
                        dev->minor);
                return -EAGAIN;
        } else {
                fx2delay = period / ((int)(6 * 512 * (1.0 / 0.033))) - 6;
                if (fx2delay > 255) {
                        dev_err(&this_usbduxsub->interface->dev,
                                "comedi%d: period %d for pwm is too low.\n",
                                dev->minor, period);
                        return -EAGAIN;
                }
        }
        this_usbduxsub->pwmDelay = fx2delay;
        this_usbduxsub->pwmPeriod = period;
        dev_dbg(&this_usbduxsub->interface->dev, "%s: frequ=%d, period=%d\n",
                __func__, period, fx2delay);
        return 0;
}

/* is called from insn so there's no need to do all the sanity checks */
static int usbdux_pwm_start(struct comedi_device *dev,
                            struct comedi_subdevice *s)
{
        int ret, i;
        struct usbduxsub *this_usbduxsub = dev->private;

        dev_dbg(&this_usbduxsub->interface->dev, "comedi%d: %s\n",
                dev->minor, __func__);

        if (this_usbduxsub->pwm_cmd_running) {
                /* already running */
                return 0;
        }

        this_usbduxsub->dux_commands[1] = ((uint8_t) this_usbduxsub->pwmDelay);
        ret = send_dux_commands(this_usbduxsub, SENDPWMON);
        if (ret < 0)
                return ret;

        /* initialise the buffer */
        for (i = 0; i < this_usbduxsub->sizePwmBuf; i++)
                ((char *)(this_usbduxsub->urbPwm->transfer_buffer))[i] = 0;

        this_usbduxsub->pwm_cmd_running = 1;
        ret = usbduxsub_submit_PwmURBs(this_usbduxsub);
        if (ret < 0) {
                this_usbduxsub->pwm_cmd_running = 0;
                return ret;
        }
        return 0;
}

/* generates the bit pattern for PWM with the optional sign bit */
static int usbdux_pwm_pattern(struct comedi_device *dev,
                              struct comedi_subdevice *s, int channel,
                              unsigned int value, unsigned int sign)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        int i, szbuf;
        char *pBuf;
        char pwm_mask;
        char sgn_mask;
        char c;

        if (!this_usbduxsub)

                return -EFAULT;

        /* this is the DIO bit which carries the PWM data */
        pwm_mask = (1 << channel);
        /* this is the DIO bit which carries the optional direction bit */
        sgn_mask = (16 << channel);
        /* this is the buffer which will be filled with the with bit */
        /* pattern for one period */
        szbuf = this_usbduxsub->sizePwmBuf;
        pBuf = (char *)(this_usbduxsub->urbPwm->transfer_buffer);
        for (i = 0; i < szbuf; i++) {
                c = *pBuf;
                /* reset bits */
                c = c & (~pwm_mask);
                /* set the bit as long as the index is lower than the value */
                if (i < value)
                        c = c | pwm_mask;
                /* set the optional sign bit for a relay */
                if (!sign) {
                        /* positive value */
                        c = c & (~sgn_mask);
                } else {
                        /* negative value */
                        c = c | sgn_mask;
                }
                *(pBuf++) = c;
        }
        return 1;
}

static int usbdux_pwm_write(struct comedi_device *dev,
                            struct comedi_subdevice *s,
                            struct comedi_insn *insn, unsigned int *data)
{
        struct usbduxsub *this_usbduxsub = dev->private;

        if (!this_usbduxsub)
                return -EFAULT;

        if ((insn->n) != 1) {
                /*
                 * doesn't make sense to have more than one value here because
                 * it would just overwrite the PWM buffer a couple of times
                 */
                return -EINVAL;
        }

        /*
         * the sign is set via a special INSN only, this gives us 8 bits for
         * normal operation
         * relay sign 0 by default
         */
        return usbdux_pwm_pattern(dev, s, CR_CHAN(insn->chanspec), data[0], 0);
}

static int usbdux_pwm_read(struct comedi_device *x1,
                           struct comedi_subdevice *x2, struct comedi_insn *x3,
                           unsigned int *x4)
{
        /* not needed */
        return -EINVAL;
};

/* switches on/off PWM */
static int usbdux_pwm_config(struct comedi_device *dev,
                             struct comedi_subdevice *s,
                             struct comedi_insn *insn, unsigned int *data)
{
        struct usbduxsub *this_usbduxsub = dev->private;
        switch (data[0]) {
        case INSN_CONFIG_ARM:
                /* switch it on */
                dev_dbg(&this_usbduxsub->interface->dev,
                        "comedi%d: %s: pwm on\n", dev->minor, __func__);
                /*
                 * if not zero the PWM is limited to a certain time which is
                 * not supported here
                 */
                if (data[1] != 0)
                        return -EINVAL;
                return usbdux_pwm_start(dev, s);
        case INSN_CONFIG_DISARM:
                dev_dbg(&this_usbduxsub->interface->dev,
                        "comedi%d: %s: pwm off\n", dev->minor, __func__);
                return usbdux_pwm_cancel(dev, s);
        case INSN_CONFIG_GET_PWM_STATUS:
                /*
                 * to check if the USB transmission has failed or in case PWM
                 * was limited to n cycles to check if it has terminated
                 */
                data[1] = this_usbduxsub->pwm_cmd_running;
                return 0;
        case INSN_CONFIG_PWM_SET_PERIOD:
                dev_dbg(&this_usbduxsub->interface->dev,
                        "comedi%d: %s: setting period\n", dev->minor,
                        __func__);
                return usbdux_pwm_period(dev, s, data[1]);
        case INSN_CONFIG_PWM_GET_PERIOD:
                data[1] = this_usbduxsub->pwmPeriod;
                return 0;
        case INSN_CONFIG_PWM_SET_H_BRIDGE:
                /* value in the first byte and the sign in the second for a
                   relay */
                return usbdux_pwm_pattern(dev, s,
                                          /* the channel number */
                                          CR_CHAN(insn->chanspec),
                                          /* actual PWM data */
                                          data[1],
                                          /* just a sign */
                                          (data[2] != 0));
        case INSN_CONFIG_PWM_GET_H_BRIDGE:
                /* values are not kept in this driver, nothing to return */
                return -EINVAL;
        }
        return -EINVAL;
}

/* end of PWM */
/*****************************************************************/

static void tidy_up(struct usbduxsub *usbduxsub_tmp)
{
        int i;

        if (!usbduxsub_tmp)
                return;
        dev_dbg(&usbduxsub_tmp->interface->dev, "comedi_: tiding up\n");

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

        usbduxsub_tmp->probed = 0;

        if (usbduxsub_tmp->urbIn) {
                if (usbduxsub_tmp->ai_cmd_running) {
                        usbduxsub_tmp->ai_cmd_running = 0;
                        usbduxsub_unlink_InURBs(usbduxsub_tmp);
                }
                for (i = 0; i < usbduxsub_tmp->numOfInBuffers; i++) {
                        kfree(usbduxsub_tmp->urbIn[i]->transfer_buffer);
                        usbduxsub_tmp->urbIn[i]->transfer_buffer = NULL;
                        usb_kill_urb(usbduxsub_tmp->urbIn[i]);
                        usb_free_urb(usbduxsub_tmp->urbIn[i]);
                        usbduxsub_tmp->urbIn[i] = NULL;
                }
                kfree(usbduxsub_tmp->urbIn);
                usbduxsub_tmp->urbIn = NULL;
        }
        if (usbduxsub_tmp->urbOut) {
                if (usbduxsub_tmp->ao_cmd_running) {
                        usbduxsub_tmp->ao_cmd_running = 0;
                        usbduxsub_unlink_OutURBs(usbduxsub_tmp);
                }
                for (i = 0; i < usbduxsub_tmp->numOfOutBuffers; i++) {
                        if (usbduxsub_tmp->urbOut[i]->transfer_buffer) {
                                kfree(usbduxsub_tmp->
                                      urbOut[i]->transfer_buffer);
                                usbduxsub_tmp->urbOut[i]->transfer_buffer =
                                    NULL;
                        }
                        if (usbduxsub_tmp->urbOut[i]) {
                                usb_kill_urb(usbduxsub_tmp->urbOut[i]);
                                usb_free_urb(usbduxsub_tmp->urbOut[i]);
                                usbduxsub_tmp->urbOut[i] = NULL;
                        }
                }
                kfree(usbduxsub_tmp->urbOut);
                usbduxsub_tmp->urbOut = NULL;
        }
        if (usbduxsub_tmp->urbPwm) {
                if (usbduxsub_tmp->pwm_cmd_running) {
                        usbduxsub_tmp->pwm_cmd_running = 0;
                        usbduxsub_unlink_PwmURBs(usbduxsub_tmp);
                }
                kfree(usbduxsub_tmp->urbPwm->transfer_buffer);
                usbduxsub_tmp->urbPwm->transfer_buffer = NULL;
                usb_kill_urb(usbduxsub_tmp->urbPwm);
                usb_free_urb(usbduxsub_tmp->urbPwm);
                usbduxsub_tmp->urbPwm = NULL;
        }
        kfree(usbduxsub_tmp->inBuffer);
        usbduxsub_tmp->inBuffer = NULL;
        kfree(usbduxsub_tmp->insnBuffer);
        usbduxsub_tmp->insnBuffer = NULL;
        kfree(usbduxsub_tmp->outBuffer);
        usbduxsub_tmp->outBuffer = NULL;
        kfree(usbduxsub_tmp->dac_commands);
        usbduxsub_tmp->dac_commands = NULL;
        kfree(usbduxsub_tmp->dux_commands);
        usbduxsub_tmp->dux_commands = NULL;
        usbduxsub_tmp->ai_cmd_running = 0;
        usbduxsub_tmp->ao_cmd_running = 0;
        usbduxsub_tmp->pwm_cmd_running = 0;
}

static int usbduxsigma_attach_common(struct comedi_device *dev,
                                     struct usbduxsub *uds)
{
        int ret;
        struct comedi_subdevice *s;
        int n_subdevs;
        int offset;

        down(&uds->sem);
        /* pointer back to the corresponding comedi device */
        uds->comedidev = dev;

        /* set number of subdevices */
        if (uds->high_speed)
                n_subdevs = 4;  /* with pwm */
        else
                n_subdevs = 3;  /* without pwm */
        ret = comedi_alloc_subdevices(dev, n_subdevs);
        if (ret) {
                up(&uds->sem);
                return ret;
        }
        /* private structure is also simply the usb-structure */
        dev->private = uds;
        /* 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, 32 bit wide data! */
        s->subdev_flags = SDF_READABLE | SDF_GROUND |
                SDF_CMD_READ | SDF_LSAMPL;
        /* 16 A/D channels */
        s->n_chan = NUMCHANNELS;
        /* length of the channellist */
        s->len_chanlist = NUMCHANNELS;
        /* callback functions */
        s->insn_read = usbdux_ai_insn_read;
        s->do_cmdtest = usbdux_ai_cmdtest;
        s->do_cmd = usbdux_ai_cmd;
        s->cancel = usbdux_ai_cancel;
        /* max value from the A/D converter (24bit) */
        s->maxdata = 0x00FFFFFF;
        /* range table to convert to physical units */
        s->range_table = (&range_usbdux_ai_range);
        /* analog output subdevice */
        s = &dev->subdevices[SUBDEV_DA];
        /* analog out */
        s->type = COMEDI_SUBD_AO;
        /* backward pointer */
        dev->write_subdev = s;
        /* the subdevice receives as private structure the */
        /* usb-structure */
        s->private = NULL;
        /* are writable */
        s->subdev_flags = SDF_WRITABLE | SDF_GROUND | SDF_CMD_WRITE;
        /* 4 channels */
        s->n_chan = 4;
        /* length of the channellist */
        s->len_chanlist = 4;
        /* 8 bit resolution */
        s->maxdata = 0x00ff;
        /* unipolar range */
        s->range_table = &range_unipolar2_5;
        /* callback */
        s->do_cmdtest = usbdux_ao_cmdtest;
        s->do_cmd = usbdux_ao_cmd;
        s->cancel = usbdux_ao_cancel;
        s->insn_read = usbdux_ao_insn_read;
        s->insn_write = usbdux_ao_insn_write;
        /* digital I/O subdevice */
        s = &dev->subdevices[SUBDEV_DIO];
        s->type = COMEDI_SUBD_DIO;
        s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
        /* 8 external and 16 internal channels */
        s->n_chan = 24;
        s->maxdata = 1;
        s->range_table = (&range_digital);
        s->insn_bits = usbdux_dio_insn_bits;
        s->insn_config = usbdux_dio_insn_config;
        /* we don't use it */
        s->private = NULL;
        if (uds->high_speed) {
                /* timer / pwm subdevice */
                s = &dev->subdevices[SUBDEV_PWM];
                s->type = COMEDI_SUBD_PWM;
                s->subdev_flags = SDF_WRITABLE | SDF_PWM_HBRIDGE;
                s->n_chan = 8;
                /* this defines the max duty cycle resolution */
                s->maxdata = uds->sizePwmBuf;
                s->insn_write = usbdux_pwm_write;
                s->insn_read = usbdux_pwm_read;
                s->insn_config = usbdux_pwm_config;
                usbdux_pwm_period(dev, s, PWM_DEFAULT_PERIOD);
        }
        /* finally decide that it's attached */
        uds->attached = 1;
        up(&uds->sem);
        offset = usbdux_getstatusinfo(dev, 0);
        if (offset < 0)
                dev_err(&uds->interface->dev,
                        "Communication to USBDUXSIGMA failed! Check firmware and cabling.");
        dev_info(&uds->interface->dev,
                 "comedi%d: attached, ADC_zero = %x\n", dev->minor, offset);
        return 0;
}

static int usbduxsigma_auto_attach(struct comedi_device *dev,
                                   unsigned long context_unused)
{
        struct usb_interface *uinterf = comedi_to_usb_interface(dev);
        int ret;
        struct usbduxsub *uds;

        dev->private = NULL;
        down(&start_stop_sem);
        uds = usb_get_intfdata(uinterf);
        if (!uds || !uds->probed) {
                dev_err(dev->class_dev,
                        "usbduxsigma: error: auto_attach failed, not connected\n");
                ret = -ENODEV;
        } else if (uds->attached) {
                dev_err(dev->class_dev,
                       "usbduxsigma: error: auto_attach failed, already attached\n");
                ret = -ENODEV;
        } else
                ret = usbduxsigma_attach_common(dev, uds);
        up(&start_stop_sem);
        return ret;
}

static void usbduxsigma_detach(struct comedi_device *dev)
{
        struct usbduxsub *usb = dev->private;

        if (usb) {
                down(&usb->sem);
                dev->private = NULL;
                usb->attached = 0;
                usb->comedidev = NULL;
                up(&usb->sem);
        }
}

static struct comedi_driver usbduxsigma_driver = {
        .driver_name    = "usbduxsigma",
        .module         = THIS_MODULE,
        .auto_attach    = usbduxsigma_auto_attach,
        .detach         = usbduxsigma_detach,
};

static void usbdux_firmware_request_complete_handler(const struct firmware *fw,
                                                     void *context)
{
        struct usbduxsub *usbduxsub_tmp = context;
        struct usb_interface *uinterf = usbduxsub_tmp->interface;
        int ret;

        if (fw == NULL) {
                dev_err(&uinterf->dev,
                        "Firmware complete handler without firmware!\n");
                return;
        }

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

        if (ret) {
                dev_err(&uinterf->dev,
                        "Could not upload firmware (err=%d)\n", ret);
                goto out;
        }
        comedi_usb_auto_config(uinterf, &usbduxsigma_driver, 0);
out:
        release_firmware(fw);
}

static int usbduxsigma_usb_probe(struct usb_interface *uinterf,
                                 const struct usb_device_id *id)
{
        struct usb_device *udev = interface_to_usbdev(uinterf);
        struct device *dev = &uinterf->dev;
        int i;
        int index;
        int ret;

        dev_dbg(dev, "comedi_: usbdux_: "
                "finding a free structure for the usb-device\n");

        down(&start_stop_sem);
        /* look for a free place in the usbdux array */
        index = -1;
        for (i = 0; i < NUMUSBDUX; i++) {
                if (!(usbduxsub[i].probed)) {
                        index = i;
                        break;
                }
        }

        /* no more space */
        if (index == -1) {
                dev_err(dev, "Too many usbduxsigma-devices connected.\n");
                up(&start_stop_sem);
                return -EMFILE;
        }
        dev_dbg(dev, "comedi_: usbdux: "
                "usbduxsub[%d] is ready to connect to comedi.\n", index);

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

        /* save the interface itself */
        usbduxsub[index].interface = uinterf;
        /* get the interface number from the interface */
        usbduxsub[index].ifnum = uinterf->altsetting->desc.bInterfaceNumber;
        /* hand the private data over to the usb subsystem */
        /* will be needed for disconnect */
        usb_set_intfdata(uinterf, &(usbduxsub[index]));

        dev_dbg(dev, "comedi_: usbdux: ifnum=%d\n", usbduxsub[index].ifnum);

        /* test if it is high speed (USB 2.0) */
        usbduxsub[index].high_speed =
            (usbduxsub[index].usbdev->speed == USB_SPEED_HIGH);

        /* create space for the commands of the DA converter */
        usbduxsub[index].dac_commands = kzalloc(NUMOUTCHANNELS, GFP_KERNEL);
        if (!usbduxsub[index].dac_commands) {
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        /* create space for the commands going to the usb device */
        usbduxsub[index].dux_commands = kzalloc(SIZEOFDUXBUFFER, GFP_KERNEL);
        if (!usbduxsub[index].dux_commands) {
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        /* create space for the in buffer and set it to zero */
        usbduxsub[index].inBuffer = kzalloc(SIZEINBUF, GFP_KERNEL);
        if (!(usbduxsub[index].inBuffer)) {
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        /* create space of the instruction buffer */
        usbduxsub[index].insnBuffer = kzalloc(SIZEINSNBUF, GFP_KERNEL);
        if (!(usbduxsub[index].insnBuffer)) {
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        /* create space for the outbuffer */
        usbduxsub[index].outBuffer = kzalloc(SIZEOUTBUF, GFP_KERNEL);
        if (!(usbduxsub[index].outBuffer)) {
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        /* setting to alternate setting 3: enabling iso ep and bulk ep. */
        i = usb_set_interface(usbduxsub[index].usbdev,
                              usbduxsub[index].ifnum, 3);
        if (i < 0) {
                dev_err(dev, "comedi_: usbduxsigma%d: "
                        "could not set alternate setting 3 in high speed.\n",
                        index);
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENODEV;
        }
        if (usbduxsub[index].high_speed)
                usbduxsub[index].numOfInBuffers = NUMOFINBUFFERSHIGH;
        else
                usbduxsub[index].numOfInBuffers = NUMOFINBUFFERSFULL;

        usbduxsub[index].urbIn = kcalloc(usbduxsub[index].numOfInBuffers,
                                         sizeof(struct urb *),
                                         GFP_KERNEL);
        if (!(usbduxsub[index].urbIn)) {
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        for (i = 0; i < usbduxsub[index].numOfInBuffers; i++) {
                /* one frame: 1ms */
                usbduxsub[index].urbIn[i] = usb_alloc_urb(1, GFP_KERNEL);
                if (usbduxsub[index].urbIn[i] == NULL) {
                        dev_err(dev, "comedi_: usbduxsigma%d: "
                                "Could not alloc. urb(%d)\n", index, i);
                        tidy_up(&(usbduxsub[index]));
                        up(&start_stop_sem);
                        return -ENOMEM;
                }
                usbduxsub[index].urbIn[i]->dev = usbduxsub[index].usbdev;
                /* will be filled later with a pointer to the comedi-device */
                /* and ONLY then the urb should be submitted */
                usbduxsub[index].urbIn[i]->context = NULL;
                usbduxsub[index].urbIn[i]->pipe =
                    usb_rcvisocpipe(usbduxsub[index].usbdev, ISOINEP);
                usbduxsub[index].urbIn[i]->transfer_flags = URB_ISO_ASAP;
                usbduxsub[index].urbIn[i]->transfer_buffer =
                    kzalloc(SIZEINBUF, GFP_KERNEL);
                if (!(usbduxsub[index].urbIn[i]->transfer_buffer)) {
                        tidy_up(&(usbduxsub[index]));
                        up(&start_stop_sem);
                        return -ENOMEM;
                }
                usbduxsub[index].urbIn[i]->complete = usbduxsub_ai_IsocIrq;
                usbduxsub[index].urbIn[i]->number_of_packets = 1;
                usbduxsub[index].urbIn[i]->transfer_buffer_length = SIZEINBUF;
                usbduxsub[index].urbIn[i]->iso_frame_desc[0].offset = 0;
                usbduxsub[index].urbIn[i]->iso_frame_desc[0].length =
                        SIZEINBUF;
        }

        /* out */
        if (usbduxsub[index].high_speed)
                usbduxsub[index].numOfOutBuffers = NUMOFOUTBUFFERSHIGH;
        else
                usbduxsub[index].numOfOutBuffers = NUMOFOUTBUFFERSFULL;

        usbduxsub[index].urbOut = kcalloc(usbduxsub[index].numOfOutBuffers,
                                          sizeof(struct urb *), GFP_KERNEL);
        if (!(usbduxsub[index].urbOut)) {
                tidy_up(&(usbduxsub[index]));
                up(&start_stop_sem);
                return -ENOMEM;
        }
        for (i = 0; i < usbduxsub[index].numOfOutBuffers; i++) {
                /* one frame: 1ms */
                usbduxsub[index].urbOut[i] = usb_alloc_urb(1, GFP_KERNEL);
                if (usbduxsub[index].urbOut[i] == NULL) {
                        dev_err(dev, "comedi_: usbduxsigma%d: "
                                "Could not alloc. urb(%d)\n", index, i);
                        tidy_up(&(usbduxsub[index]));
                        up(&start_stop_sem);
                        return -ENOMEM;
                }
                usbduxsub[index].urbOut[i]->dev = usbduxsub[index].usbdev;
                /* will be filled later with a pointer to the comedi-device */
                /* and ONLY then the urb should be submitted */
                usbduxsub[index].urbOut[i]->context = NULL;
                usbduxsub[index].urbOut[i]->pipe =
                    usb_sndisocpipe(usbduxsub[index].usbdev, ISOOUTEP);
                usbduxsub[index].urbOut[i]->transfer_flags = URB_ISO_ASAP;
                usbduxsub[index].urbOut[i]->transfer_buffer =
                    kzalloc(SIZEOUTBUF, GFP_KERNEL);
                if (!(usbduxsub[index].urbOut[i]->transfer_buffer)) {
                        tidy_up(&(usbduxsub[index]));
                        up(&start_stop_sem);
                        return -ENOMEM;
                }
                usbduxsub[index].urbOut[i]->complete = usbduxsub_ao_IsocIrq;
                usbduxsub[index].urbOut[i]->number_of_packets = 1;
                usbduxsub[index].urbOut[i]->transfer_buffer_length =
                        SIZEOUTBUF;
                usbduxsub[index].urbOut[i]->iso_frame_desc[0].offset = 0;
                usbduxsub[index].urbOut[i]->iso_frame_desc[0].length =
                    SIZEOUTBUF;
                if (usbduxsub[index].high_speed) {
                        /* uframes */
                        usbduxsub[index].urbOut[i]->interval = 8;
                } else {
                        /* frames */
                        usbduxsub[index].urbOut[i]->interval = 1;
                }
        }

        /* pwm */
        if (usbduxsub[index].high_speed) {
                /* max bulk ep size in high speed */
                usbduxsub[index].sizePwmBuf = 512;
                usbduxsub[index].urbPwm = usb_alloc_urb(0, GFP_KERNEL);
                if (usbduxsub[index].urbPwm == NULL) {
                        dev_err(dev, "comedi_: usbduxsigma%d: "
                                "Could not alloc. pwm urb\n", index);
                        tidy_up(&(usbduxsub[index]));
                        up(&start_stop_sem);
                        return -ENOMEM;
                }
                usbduxsub[index].urbPwm->transfer_buffer =
                    kzalloc(usbduxsub[index].sizePwmBuf, GFP_KERNEL);
                if (!(usbduxsub[index].urbPwm->transfer_buffer)) {
                        tidy_up(&(usbduxsub[index]));
                        up(&start_stop_sem);
                        return -ENOMEM;
                }
        } else {
                usbduxsub[index].urbPwm = NULL;
                usbduxsub[index].sizePwmBuf = 0;
        }

        usbduxsub[index].ai_cmd_running = 0;
        usbduxsub[index].ao_cmd_running = 0;
        usbduxsub[index].pwm_cmd_running = 0;

        /* we've reached the bottom of the function */
        usbduxsub[index].probed = 1;
        up(&start_stop_sem);

        ret = request_firmware_nowait(THIS_MODULE,
                                      FW_ACTION_HOTPLUG,
                                      FIRMWARE,
                                      &udev->dev,
                                      GFP_KERNEL,
                                      usbduxsub + index,
                                      usbdux_firmware_request_complete_handler
                                      );

        if (ret) {
                dev_err(dev, "Could not load firmware (err=%d)\n", ret);
                return ret;
        }

        dev_info(dev, "comedi_: successfully initialised.\n");
        /* success */
        return 0;
}

static void usbduxsigma_usb_disconnect(struct usb_interface *intf)
{
        struct usbduxsub *usbduxsub_tmp = usb_get_intfdata(intf);
        struct usb_device *udev = interface_to_usbdev(intf);

        if (!usbduxsub_tmp) {
                dev_err(&intf->dev,
                        "comedi_: disconnect called with null pointer.\n");
                return;
        }
        if (usbduxsub_tmp->usbdev != udev) {
                dev_err(&intf->dev, "comedi_: BUG! wrong ptr!\n");
                return;
        }
        if (usbduxsub_tmp->ai_cmd_running)
                /* we are still running a command */
                usbdux_ai_stop(usbduxsub_tmp, 1);
        if (usbduxsub_tmp->ao_cmd_running)
                /* we are still running a command */
                usbdux_ao_stop(usbduxsub_tmp, 1);
        comedi_usb_auto_unconfig(intf);
        down(&start_stop_sem);
        down(&usbduxsub_tmp->sem);
        tidy_up(usbduxsub_tmp);
        up(&usbduxsub_tmp->sem);
        up(&start_stop_sem);
        dev_info(&intf->dev, "comedi_: disconnected from the usb\n");
}

static const struct usb_device_id usbduxsigma_usb_table[] = {
        { USB_DEVICE(0x13d8, 0x0020) },
        { USB_DEVICE(0x13d8, 0x0021) },
        { USB_DEVICE(0x13d8, 0x0022) },
        { }
};
MODULE_DEVICE_TABLE(usb, usbduxsigma_usb_table);

static struct usb_driver usbduxsigma_usb_driver = {
        .name           = "usbduxsigma",
        .probe          = usbduxsigma_usb_probe,
        .disconnect     = usbduxsigma_usb_disconnect,
        .id_table       = usbduxsigma_usb_table,
};
module_comedi_usb_driver(usbduxsigma_driver, usbduxsigma_usb_driver);

MODULE_AUTHOR("Bernd Porr, BerndPorr@f2s.com");
MODULE_DESCRIPTION("Stirling/ITL USB-DUX SIGMA -- Bernd.Porr@f2s.com");
MODULE_LICENSE("GPL");
MODULE_FIRMWARE(FIRMWARE);