Messages in this thread | | | Date | Mon, 29 Nov 2010 08:32:11 -0800 | From | "Ira W. Snyder" <> | Subject | Re: [PATCH 3/5] fpga: add basic CARMA board support |
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On Mon, Nov 29, 2010 at 11:38:14AM +1100, Benjamin Herrenschmidt wrote: > On Wed, 2010-09-08 at 09:41 -0700, Ira W. Snyder wrote: > > This adds basic support for the system controller FPGA on the OVRO CARMA > > board. This patch only adds infrastructure that will be used by later > > drivers. > > Oh and another comment ... > > I'm not sure about drivers/fpga ... in the end, one would expect such a > directory to contain stuff to manipulate FPGAs in the sense of > downloading bitfiles, instanciating devices (device-tree manipulation ?) > etc... > > From what I see in your code, the fact that these are FPGAs is almost > irrelevant, you are providing support for "carma" devices, and such are > no different than some other platform device, they just happen to be > implemented as FPGAs. Or am I missing something ? >
You are exactly right. They are just regular platform devices. One devices does happen to be a bitfile downloading driver (carma-fpga-program), but it does not create any generic infrastructure for downloading bitfiles.
Regarding your earlier comment about the carma class: no, it isn't necessary. I found it convenient to have everything related to this hardware appear in /sys/class/carma/, nothing more. It just wasn't as easy to remember something like: /sys/bus/platform/devices/f0000000.carma-fpga/.
I was thinking about changing the drivers from generic char devices into misc devices instead. The sysfs interface would move from /sys/class/carma/carma-fpga to /sys/class/misc/carma-fpga (for example), but that is easy enough to remember.
Rather than putting the source code in drivers/fpga/carma, what about drivers/misc/carma instead? I've already done that in my local tree, and I'm much happier with the result.
Thanks for the comments.
Ira
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