On Tue Dec 31 12:47:30 EST 2013, krystian....@gmail.com wrote:
> Thank you for the feedback, i think "ctl" file and numbering scheme
> selection could do the job. And maybe it could help to establish
> reasonable base for SPI and others.
>
> Is it safe to just generate new dev tree - to return either BCM,
> WiringPi or board pin set - based on pin numbering scheme selection
> made by user? What will happen if a process would try o read/write
> from/to pin when numbering scheme is changed? I tried to look at
> devproc.c (what would happen when process dies and something is
> reading its /proc entries) but i can.FN"t see any specific
> precautions there.
(sorry about the funny formatting. the header specifies
Content-Type: text/plain; charset=iso-2022-jp-2
which might be the same as iso-2022-jp, but i haven't tracked this down yet.)
there is a 1 character argument to attach. you can avoid the issue
by letting the attach argument specify which scheme you'd like, e.g.:
mount -a '#Gx' /dev
> Regarding ISRs - this is not implemented yet. Polling at the moment
> is the only option. But maybe "events$B!I(B file, with data
> populated by interrupt routine would be the answer. Is it correct
> Plan 9 way of doing things? QIO looks very suitable for this purpose.
"long" reads are an established way to avoid polling. plan 9
was doing this long before i'd heard the term. the network drivers
work this way.
- erik
