Re: multiple subdevice commands

On 16/11/06 01:13, Frank Mori Hess wrote:
> I've made some changes to cvs, so now every subdevice that supports 
> commands produces a device file (using udev) called /dev/comediX_subdY 
> corresponding to subdevice Y on board X.  This will allow a driver to 
> support read or write commands on multiple subdevices.  There are new 
> subdevice flags SUBD_CMD_READ and SUBD_CMD_WRITE to indicate the direction 
> a subdevice supports commands in.  All the drivers have been updated with 
> the new subdevice flags.  I also broke compilation on 2.4 kernels.

Just a thought...

I'm wondering if it's theoretically possible to do this with a single 
device file and use some ioctl calls to choose which subdevices to hook 
the read and write operations to.  This would require some stuff to be 
moved into a "per file object" data structure that points to the main 
comedi device structure, so that one could open the main device file 
multiple times and tell each instance where to hook the read and write 
operations.  Sounds like a lot of work though. ;-)

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-=( Ian Abbott _at_ MEV Ltd.    E-mail: <abbotti_at_mev.co.uk>        )=-
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Received on 2006-11-22Z13:23:40