Re: [PATCH] regulator: mc13783: consider Power Gates as digitalregulators.

From: Alberto Panizzo
Date: Mon Jan 18 2010 - 12:50:27 EST


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.


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