linux-kernel - Implementing a gpio based regulator with status pins

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <555FF8AD.5010502@roeck-us.net>
Date:	Fri, 22 May 2015 20:49:01 -0700
From:	Guenter Roeck <linux@...ck-us.net>
To:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
CC:	Mark Brown <broonie@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>
Subject: Implementing a gpio based regulator with status pins

Hi all,

I have a system with a gpio based regulator which does not only have an
enable pin, but also a status pin to report the actual power status.
In some cases there may be a secondary status pin, making it possible
to report on/off/error.

Some twist of this is that power activation time is not exactly well
defined; activation can vary from board to board. I could of course
use the existing (fixed) timeout supported by the regulator core,
but it would be nice to be able to use an interrupt on the status
pin(s), possibly with a timeout, to achieve a dynamic activation
time.

The gpio pin(s) support interrupts, making it possible to report
status updates, which might be useful if the power source goes bad
or to support a dynamic power enable time.

As far as I can see, the existing gpio regulators don't implement
status pins.

What would be the best way to implement this ?

- Add status support to the 'fixed' regulator
- Add status support to gpio-regulator.c
- Add (gpio) status support to the regulator core
- Write a new regulator driver
- Something else

Thanks,
Guenter
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/