Re: kern/51676 (Enhancement - interrupt support for RPI gpio, kevents for gpio.c, PPS driver for gpio, and more)

[Jason Thorpe <thorpej%me.com@localhost>]

The following reply was made to PR kern/51676; it has been noted by GNATS.

From: Jason Thorpe <thorpej%me.com@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: kern/51676 (Enhancement - interrupt support for RPI gpio,
 kevents for gpio.c, PPS driver for gpio, and more)
Date: Tue, 01 May 2018 09:31:24 -0700

 > On May 1, 2018, at 5:15 AM, Brad Spencer <brad%anduin.eldar.org@localhost> =
 wrote:
 > Hello...
 >=20
 > I was the one who put in this PR..  You may want to visit my web site:
 
 Hey Brad =E2=80=94 thanks for following up.  Cool stuff!  The project =
 I=E2=80=99m using this for is a Nixie tube display clock.
 
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 > http://anduin.eldar.org/stratum-1
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 > and download MUCH improved patches for some of what was in the PR.
 
 Great, noted.
 
 >=20
 >=20
 > I have not had time to update anything to support the FDTization that
 > occurred with the RPI, so all patches are very much pre-FDT.  Sorry...
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 > I was also mostly unclear if the RPI will support interrupts coming to
 > more than one CPU core.  Right now, the patches pretty much have CPU0
 > handle the interrupts.  This won't be a problem for PPS, but may very
 > well be a problem if there is a high number of interrupts occurring on =
 a
 > pin, such as what can happen here:
 
 I=E2=80=99ll have a look in the documentation.  I am doing my Nixie =
 project on a Pi B+, but I also have a Pi 3 for general hackery (and =
 eventually a cocktail table game system with important titles like Ms =
 Pac Man and Galaga), so if I can figure out how to steer interrupts to =
 other CPUs, I=E2=80=99ll work on it on that platform.
 
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 > http://anduin.eldar.org/true-rng
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 > for one of the true rng generators I built.
 
 This is excellent!
 
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 > I would love to see GPIO interrupts official for the RPI as well=E2=80=A6=
 .
 
 Yah, I=E2=80=99ll definitely be integrating that part.  In particular, =
 the thing I=E2=80=99m most interested in is the interrupt support, which =
 I will then enhance =E2=80=9Cgpiokeys=E2=80=9D with (I=E2=80=99d prefer =
 to generate the UI events for the buttons on the clock housing [snooze, =
 etc] without resorting using an AVR to generate USB events), and I =
 really loathe polling :-)
 
 Anyway, I=E2=80=99ll be working on it in the coming weeks (and I have a =
 couple of cross-country flights coming up, so that=E2=80=99ll give me =
 some extra time).
 
 Thanks for doing this work!
 
 >=20
 >=20
 >=20
 > --=20
 > Brad Spencer - brad%anduin.eldar.org@localhost - KC8VKS - =
 http://anduin.eldar.org
 >=20
 
 -- thorpej