linux-kernel - Re: [PATCH] regulator: mc13783: consider Power Gates as digital regulators.

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: <1263837004.3632.52.camel@realization>
Date:	Mon, 18 Jan 2010 18:50:04 +0100
From:	Alberto Panizzo <maramaopercheseimorto@...il.com>
To:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
Cc:	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	Samuel Ortiz <sameo@...ux.intel.com>,
	Liam Girdwood <lrg@...mlogic.co.uk>,
	Sascha linux-arm <s.hauer@...gutronix.de>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	linux-arm-kernel-infradead <linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH] regulator: mc13783: consider Power Gates as digital
 regulators.

On lun, 2010-01-18 at 17:20 +0000, Mark Brown wrote:
> On Mon, Jan 18, 2010 at 06:07:53PM +0100, Alberto Panizzo wrote:
> 
> > Something like this?
> > 	if (mask & MC13783_REG_POWERMISC_PWGTSPI_M) {
> > 		u32 new_state = (val & MC13783_REG_POWERMISC_PWGTSPI_M) ^ mask;
> > 
> > 		mc13783_state_powermisc_pwgt =
> > 			(mc13783_state_powermisc_pwgt & ~mask) | new_state;
> > 	}
> 
> Yes, that's clearer.
> 
> > > > +	if (ret)
> > > > +		return ret;
> > > > +
> > > > +	valread = (valread & ~mask) | val;
> > > > +
> > > > +	/* Re propose the stored state for Power Gates */
> > > > +	valread = (valread & ~MC13783_REG_POWERMISC_PWGTSPI_M) |
> > > > +						mc13783_state_powermisc_pwgt;
> > > 
> > > ...and this further mainpulation.
> 
> > What is obscure in this? it is the same operation as the previous
> > MC13783_REG_POWERMISC_PWGTSPI_M is the mask for PWGT1 and 2 bits and in 
> > mc13783_state_powermisc_pwgt there is the stored state for those two bits.
> 
> Part of it is the fact that the first bit was almost completely opaque
> but even so it would be less surprising if you first worked out the
> value you wanted to set, then did whatever manipulation was required to
> translate into the format that actually gets written.

Maybe I not deep explained what's going on..
In POWERMISC register there are other controls bits than PWGTxEN that follow
the convention of 1= enable 0= disable and for those bits read and write value
are consistent: what is written could be read.

So, for all these bits the way to manipulate is the normal:
	valread = (valread & ~mask) | val;

where the mask can indicate the manipulation of not only one bit.
As "mask" could contain manipulation of PWGTxEN bits, what I do is to overwrite
those with the previously updated value:
	valread = (valread & ~MC13783_REG_POWERMISC_PWGTSPI_M) |
						mc13783_state_powermisc_pwgt;

mc13783_state_powermisc_pwgt is maintained to be 0 in bits other than 
MC13783_REG_POWERMISC_PWGTSPI_M mask.
I got me much clear?
I misunderstood the question?

Sorry my English please.. :)
Thanks!

Alberto.


--
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/