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Date:   Sat, 3 Jul 2021 18:31:11 +0200
From:   Andreas Kemnade <andreas@kemnade.info>
To:     Jonathan Cameron <jic23@kernel.org>
Cc:     lee.jones@linaro.org, robh+dt@kernel.org, lars@metafoo.de,
        sre@kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-iio@vger.kernel.org,
        linux-pm@vger.kernel.org, leonard.crestez@nxp.com,
        letux-kernel@openphoenux.org
Subject: Re: [PATCH 2/4] mfd: rn5t618: Add of compatibles for ADC and power
Message-ID: <20210703183111.2b2b9b4f@aktux>
In-Reply-To: <20210703170405.60828c57@jic23-huawei>
References: <20210703084224.31623-1-andreas@kemnade.info>
        <20210703084224.31623-3-andreas@kemnade.info>
        <20210703170405.60828c57@jic23-huawei>
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Hi,

On Sat, 3 Jul 2021 17:04:05 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Sat,  3 Jul 2021 10:42:22 +0200
> Andreas Kemnade <andreas@kemnade.info> wrote:
> 
> > This allows having devicetree nodes for the subdevices.
> > 
> > Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
> > ---
> >  drivers/mfd/rn5t618.c | 6 ++++--
> >  1 file changed, 4 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/mfd/rn5t618.c b/drivers/mfd/rn5t618.c
> > index 384acb459427..b916c7471ca3 100644
> > --- a/drivers/mfd/rn5t618.c
> > +++ b/drivers/mfd/rn5t618.c
> > @@ -24,8 +24,10 @@ static const struct mfd_cell rn5t618_cells[] = {
> >  };
> >  
> >  static const struct mfd_cell rc5t619_cells[] = {
> > -	{ .name = "rn5t618-adc" },
> > -	{ .name = "rn5t618-power" },
> > +	{ .name = "rn5t618-adc",
> > +	  .of_compatible = "ricoh,rc5t619-adc" },  
> 
> Odd to have a name of 618 and a compatible of 619.  Why?
> Definitely deserves a comment if this is necessary for some reason!
> 
Background of this whole thing:
Both RN5T618 and RC5T619 have an ADC. I would expect the driver to work
for both but I cannot prove that. No RN5T618 here to test. Maybe it
requires some quirks, probably not. The only hint I have is that
a) I use register definitions added to the kernel for RN5T618 support
b) public datasheets looks same regarding the ADC.
c) out-of-tree code for the RN5T618 does not give a clear picture, it
shows no differences but is not complete enough to judge.

To avoid introducing untested things, I am only adding it to the
rc5t619_cell list. I would really hope that someone does some rn5t618
tests... Because everything else which is both for the RN5T618 and
RC5T619 uses rn5t618 as a name, I continued that practise.

The subdevice driver also gets the information whether it is a rn5t618
or rc5t619 via rn5t618->variant, so it can handle things.

> > +	{ .name = "rn5t618-power",
> > +	  .of_compatible = "ricoh,rc5t619-power" },

Similar situation here.

> >  	{ .name = "rn5t618-regulator" },
> >  	{ .name = "rc5t619-rtc" },
and this one definitively only exists in the rc5t619.

> >  	{ .name = "rn5t618-wdt" },  
> 
> 

Regards,
Andreas