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:

quoted

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