need help with my first device driver

[greg@kroah.com (Greg KH)]

On Fri, Apr 29, 2011 at 03:10:53PM +0530, Prashant Shah wrote:
> Hi,
> 
> I am trying to write a comedi (drivers/staging/comedi) based driver
> for the National Instruments USB 6008 USB based data acquisition card.
> 
> I have created a basic but more simpler structure for the drivers
> based on usbdux driver which are already present. I have got to the
> point where the device is detected and drivers are loaded. The
> /dev/comedi0 device file is created. I am unable to deal with the data
> transfer. When I try to run xoscope that is used to read the output
> from the card - the card freezes (the status lights stop blinking).
> 
> Output from the lsusb :
> https://github.com/prashants/temptest/blob/8e81e7fb4ea260fa24e68f43c185d768aec48023/device.txt
> Source of the driver :
> https://github.com/prashants/temptest/blob/8e81e7fb4ea260fa24e68f43c185d768aec48023/drivers/ni_usb6008.c
> Device : http://sine.ni.com/nips/cds/view/p/lang/en/nid/201986
> 
> I am not interested in the digital input/output and analog output at
> this point. My main concern is the ability to read the analog input.

I would recommend asking this on the comedi mailing list.

But, I would really not recommend writing a new driver for the comedi
subsystem, instead, look at the iio subsystem, which is what I want to
move the comedi drivers over to once it settles down.  There is an
active developer community for the drivers, and a subsystem maintainer,
and people should be able to give you lots of help with your code if you
post it to their list and ask for help (hint, post the code, not a link
to the code so it can be reviewed in-line.)

Good luck,

greg k-h