On 05/04/2018 05:07 AM, Jörn Dreyer wrote:
> I am currently working on a driver for a PCI card. To access this card I have
> writen a small uio kernel driver for Linux based on the concept from mrfio2.
Did you see the 'uio_pci_generic' driver which comes with Linux, and my
'pci_generic_msi' variant in devlib2?
> In the asynDriver that I'm working on I use devlib2 to get access to the
> mapped memory regions of the card following the concept of evrMrmApp from
> mrfio2. In mrfCommon a lot of macros (BITSET, BITCLR, READS and WRITE for
> various bitwidth) are defined.
Which ones would you find useful? I didn't port them over because, in hindsight
I'm not sure they were so helpful to me.
The original goal was to prevent unintentional access with an incorrect width.
eg. Using a 32-bit read of a 16-bit register. In practice with mrfioc2
this was a waste. Due to the strict recipe needed to work with both vme and pci,
only 32-bit reads could be used.
Also in hindsight, the BITSET/CLR read-modify-write macros are a recipe for
race conditions if used without preventing concurrent access (eg. interrupt
disable or mutex). This convenience was a little too convenient.
> Should these macros not be part of devlib2? This way other modules could
> profit from this work much easier. Pulling these files into my project would
> require to install the mrfio2 module even if I do not have the hardware. Not
> thinking about license conflicts that might arise if I copy the code over to
> my project.
mrfioc2 uses the same EPICS open license as devlib2, and Base itself. So I
don't think that this aspect will make your life more complicated than it
already is (if you're thinking about licensing).
> Regards,
> Jörn Dreyer
>
- Replies:
- RE: Question regarding the usage of devlib2 Kline, David
- Re: Question regarding the usage of devlib2 Jörn Dreyer
- References:
- Question regarding the usage of devlib2 Jörn Dreyer
- Navigate by Date:
- Prev:
Job Opening at Fermilab, Accelerator Controls Dennis Nicklaus
- Next:
RE: Question regarding the usage of devlib2 Kline, David
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
<2018>
2019
2020
2021
2022
2023
2024
- Navigate by Thread:
- Prev:
Question regarding the usage of devlib2 Jörn Dreyer
- Next:
RE: Question regarding the usage of devlib2 Kline, David
- Index:
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
<2018>
2019
2020
2021
2022
2023
2024
|