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Date:   Sat, 30 Sep 2023 17:17:58 +0100
From:   Jonathan Cameron <jic23@kernel.org>
To:     Jagath Jog J <jagathjog1996@gmail.com>
Cc:     Denis Benato <benato.denis96@gmail.com>,
        andriy.shevchenko@linux.intel.com, lars@metafoo.de,
        robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org,
        linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [RFC 2/2] iio: imu: Add driver for BMI323 IMU
Message-ID: <20230930171758.34689af6@jic23-huawei>
In-Reply-To: <CAM+2EuJUGu4QUCdZ7d28RaLNipJRVuASP9wSzF14k=oBoC4e_Q@mail.gmail.com>
References: <20230918080314.11959-1-jagathjog1996@gmail.com>
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        <20230924153055.0b3486f9@jic23-huawei>
        <CAM+2EuJBxj7P-ymu84u308g8LCemSEsYi_TSHYtaK9PyrhqrfA@mail.gmail.com>
        <5eb148b4-25eb-460d-9ec8-0a40bec1dc6f@gmail.com>
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On Fri, 29 Sep 2023 13:29:13 +0530
Jagath Jog J <jagathjog1996@gmail.com> wrote:

> Hi Denis,
>=20
> On Thu, Sep 28, 2023 at 2:55=E2=80=AFAM Denis Benato <benato.denis96@gmai=
l.com> wrote:
> >
> > Hello,
> >
> > Some devices (as my asus rog ally) have an ACPI node describing a BOSC0=
200 sensor. The IC being used in those devices is a  bmi323 but as a result=
 of how the ACPI table reports that device, it is detected by the existing =
kernel module and we have no way of differentiating until after the chip ID=
 probe.
> >
> > The module loaded is bmc150-accel-i2c.c which currently doesn't support=
 the bmi323 and the loading of the module just fails at chip check. =20
>=20
> bmc150 driver supports multiple accelerometer sensors such as
> bma222, bma280, bmi055 and all of them are having similar
> register map, but the bmi323 register map is completely different
> from bmc150.

Horrible bios hacks that depend on a particular driver stack
are always a pain.

Hmm. Andy (handy ACPI expert), any suggestion?

We could maybe do a wrapper driver that does appropriate checks and wraps
the probe + remove from the two drivers?  Whilst we can obviously have a
single driver that deals with radically different devices I'm not
particularly keen on that as it tends to make things less maintainable.

Jonathan

>=20
>=20
> >
> > I have solved the problem by expanding the current bmc150-accel-i2c.c a=
nd bmc150-accel-core.c files to handle that IC in almost every part: gyrosc=
ope, accelerometer and temperature sensor.
> >
> > What is the best way of organizing code to have this module mainlined? =
Is it correct leaving files called bmc150-accel-* even if it is managing an=
other IC and and not just the accelerometer part anymore?
> >
> > TIA for your time.
> >
> > Best regards,
> > Denis Benato =20
>=20
> Regards
>=20
> Jagath