Re: [PATCH v9 4/7] staging: fpga manager: add sysfs interface document

Pavel Machek
2015-07-24T12:43:09Z

On Fri 2015-07-24 07:39:15, atull wrote:
> On Fri, 24 Jul 2015, Pavel Machek wrote:
>
> Hi Pavel,
>
> Thanks for your your feedback in cleaning up these docs.
>
> > Hi!
> >
> > > +What: /sys/class/fpga_manager/<fpga>/state
> > > +Date: July 2015
> > > +KernelVersion: 4.2
> > > +Contact: Alan Tull <atull-yzvPICuk2ABMcg4IHK0kFoH6Mc4MB0Vx@public.gmane.org>
> > > +Description: Read fpga manager state as a string.
> >
> > fpga->FPGA.
>
> Yep
>
> >
> > > + Valid states may vary by manufacturer; superset is:
> > > + * unknown = can't determine state
> > > + * power off = FPGA power is off
> > > + * power up = FPGA reports power is up
> > > + * reset = FPGA held in reset state
> > > + * firmware request = firmware class request in progress
> > > + * firmware request error = firmware request failed
> > > + * write init = FPGA being prepared for programming
> > > + * write init error = Error while preparing FPGA for
> > > + programming
> > > + * write = FPGA ready to receive image data
> > > + * write error = Error while programming
> > > + * write complete = Doing post programming steps
> > > + * write complete error = Error while doing post programming
> > > + * operating = FPGA is programmed and operating
> >
>
> If I can make my intent clear, maybe we can figure out what will be most
> useful here.
>
> The intent is to provide enough detail that if something goes wrong with
> the FPGA programming (something that the driver can't take care of) then
> userspace can know that. Such as if the firmware request fails, that
> could be due to not being able to find the firmware file.
>
> > This will need some more details. "firmware request" is hardly a
> > hardware state, does it belong here?
>
> This is a superset of FPGA states and fpga manager driver states as the
> fpga manager driver is walking through the steps to get the FPGA into
> a known operating state. So it's a sequence, though some steps may get
> skipped. If there is an error, then userspace can know what step failed.
>
> Maybe this should be separated into fpga_state for hardware state and
> fpga_mgr_status (to report what step of progress the fpga manager driver
> is at during programming). I want this to be useful and still not be
> device (FPGA) specific.
>
> > Is power off or on while firmware
> > is being requested?
>
> On. It's a sequence.

Aha. Ok, so maybe noting that states normally go in the sequence (with
exception of various errors) would be enough?

Thanks,
Pavel
--
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