Re: [PATCH 2/3] regulator: qcom_spmi: Add support for PM8005

[Jeffrey Hugo]

On 5/22/2019 8:28 AM, Mark Brown wrote:
> On Wed, May 22, 2019 at 08:16:38AM -0600, Jeffrey Hugo wrote:
> > On 5/22/2019 5:01 AM, Mark Brown wrote:
> > > On Tue, May 21, 2019 at 05:16:06PM -0600, Jeffrey Hugo wrote:
>
> > > > I'm open to suggestions.  Apparently there are two register common register
> > > > schemes - the old one and the new one.  PMIC designs after some random point
> > > > in time are all the new register scheme per the documentation I see.
>
> > > > As far as I an aware, the FT426 design is the first design to be added to
> > > > this driver to make use of the new scheme, but I expect more to be supported
> > > > in future, thus I'm reluctant to make these ft426 specific in the name.
>
> > > If there's a completely new register map why are these even in the same
> > > driver?
>
> > Its not completely new, its a derivative of the old scheme.  Of the 104
> > registers, approximately 5 have been modified, therefore the new scheme is
> > 95% compatible with the old one.  Duplicating a 1883 line driver to handle a
> > change in 5% of the register space seems less than ideal. Particularly
> > considering your previous comments seem to indicate that you feel its pretty
> > trivial to handle the quirks associated with the changes in this driver.
>
> Ah, so it's not a completely new scheme but rather just a couple of
> registers that have changed.  Sharing the driver is fine then.  Ideally
> there would be some documentation from the vendor about this, a mention
> of IP revisions or some such.  If not what the DT bindings do for names
> is use the first chip things were found in.

The documentation isn't great.  There isn't really an IP revision this 
started with.  Looking at all of the PMIC designs, this actually started 
with PM8005, so I guess "common2" becomes "pm8005", and the PMS405 
should reuse that.  I'll coordinate with Jorge.

--
Jeffrey Hugo
Qualcomm Datacenter Technologies as an affiliate of Qualcomm 
Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
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