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Date:   Sat, 17 Jun 2023 19:37:15 +0100
From:   Jonathan Cameron <jic23@kernel.org>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     "Paller, Kim Seer" <KimSeer.Paller@analog.com>,
        "lars@metafoo.de" <lars@metafoo.de>,
        "lgirdwood@gmail.com" <lgirdwood@gmail.com>,
        "broonie@kernel.org" <broonie@kernel.org>,
        "Hennerich, Michael" <Michael.Hennerich@analog.com>,
        "robh@kernel.org" <robh@kernel.org>,
        "krzysztof.kozlowski@linaro.org" <krzysztof.kozlowski@linaro.org>,
        "conor+dt@kernel.org" <conor+dt@kernel.org>,
        "linux-iio@vger.kernel.org" <linux-iio@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>
Subject: Re: [PATCH v6 2/2] iio: adc: max14001: New driver
Message-ID: <20230617193715.20d0c048@jic23-huawei>
In-Reply-To: <20230617193423.42a4d66c@jic23-huawei>
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        <20230617193423.42a4d66c@jic23-huawei>
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On Sat, 17 Jun 2023 19:34:23 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Wed, 14 Jun 2023 14:53:12 +0300
> Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
>=20
> > On Wed, Jun 14, 2023 at 1:43=E2=80=AFPM Paller, Kim Seer
> > <KimSeer.Paller@analog.com> wrote: =20
> > > > From: Andy Shevchenko <andy.shevchenko@gmail.com>
> > > > Sent: Wednesday, June 14, 2023 5:12 PM   =20
> >=20
> > ...
> >  =20
> > > > > +               /* select external voltage reference source for t=
he ADC */
> > > > > +               ret =3D max14001_reg_update(st, MAX14001_CFG,
> > > > > +                                         MAX14001_CFG_EXRF, 1);
> > > > > +
> > > > > +               ret =3D regulator_get_voltage(vref);
> > > > > +               if (ret < 0)
> > > > > +                       return dev_err_probe(dev, ret,
> > > > > +                                            "Failed to get vref\=
n");   =20
> > > >
> > > > Is it important to choose the external reference source _before_ ge=
tting the
> > > > voltage of the regulator? If not, I would swap these calls, otherwi=
se the
> > > > comment is needed to explain why the sequence is important in the w=
ay it's
> > > > written.   =20
> > >
> > > It is not important. These calls can be swap without any issues.   =20
> >=20
> > If you send a new version, please swap, otherwise I hope Jonathan can
> > do it when applying.
> >  =20
>=20
> I made these changes whilst applying...
>=20
> --- a/drivers/iio/adc/max14001.c
> +++ b/drivers/iio/adc/max14001.c
> @@ -290,16 +290,19 @@ static int max14001_probe(struct spi_device *spi)
>                 if (ret)
>                         return ret;
> =20
> -               /* select external voltage reference source for the ADC */
> -               ret =3D max14001_reg_update(st, MAX14001_CFG,
> -                                         MAX14001_CFG_EXRF, 1);
> -
>                 ret =3D regulator_get_voltage(vref);
>                 if (ret < 0)
>                         return dev_err_probe(dev, ret,
>                                              "Failed to get vref\n");
> =20
>                 st->vref_mv =3D ret / 1000;
> +
> +               /* select external voltage reference source for the ADC */
> +               ret =3D max14001_reg_update(st, MAX14001_CFG,
> +                                         MAX14001_CFG_EXRF, 1);
> +
> +               if (ret < 0)
> +                       return ret;
>         }
> =20
>         mutex_init(&st->lock);
>=20
>=20
> Note that whilst I've applied this to the togreg branch of iio.git - it i=
s just
> a tiny bit too late to make the merge window that starts in about a week.
> As such I'll only push this out as testing until I can rebase the tree
> on rc1 once available.

Actually nope. Dropped it again because a question came up in my build test=
s.

I'll address that in a separate reply.

Jonathan

>=20
> Thanks,
>=20
> Jonathan