linux-kernel - Re: Recommendations for a new MFD device driver?

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-prev] [day] [month] [year] [list]

Message-ID: <20150211094259.GL12209@pengutronix.de>
Date:	Wed, 11 Feb 2015 10:42:59 +0100
From:	Sascha Hauer <s.hauer@...gutronix.de>
To:	Lee Jones <lee.jones@...aro.org>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	eddie.huang@...iatek.com, Mark Brown <broonie@...nel.org>
Subject: Re: Recommendations for a new MFD device driver?

On Tue, Feb 10, 2015 at 03:20:39PM +0800, Lee Jones wrote:
> On Fri, 06 Feb 2015, Sascha Hauer wrote:
> 
> > Hi All,
> > 
> > We are adding support for a new pretty typical MFD device, the MediaTek
> > MT6397. Initial patches are already posted. It's a PMIC which among other
> > things has regulators and a RTC. The same RTC is reused on another PMIC,
> > but with another register offset and another interrupt.
> > 
> > Now the question is where shall we put the register/irq resource
> > information?
> > 
> > 1) Put it into the RTC device driver.
> > 2) Put it into the .resource field of struct mfd_cell
> > 3) Put it into the device tree using standard reg, interrupt properties and
> >    a) Let the RTC driver interpret these
> >    b) Let the MFD driver create resources in the .resource field of struct
> >       mfd_cell
> >    c) Let the MFD core create the resources
> 
> I have no problem with 2, if that's the route you'd like to take.

Ok, thanks Lee and Mark for the input. I think we should go with option
2 then. While it's convenient to put the resources into the device tree
in the first place, it probably becomes cumbersome when Linux gets a
different idea how the subdevices of the PMIC should be arranged.

Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
--
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/