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From:   Jagath Jog J <jagathjog1996@gmail.com>
Date:   Wed, 4 Oct 2023 02:05:33 +0530
Message-ID: <CAM+2EuKJwW8i9-1Y4v7ccaT3HUHJ9E79j7cPWqzbig_tcFWxSA@mail.gmail.com>
Subject: Re: [RFC 2/2] iio: imu: Add driver for BMI323 IMU
To:     Denis Benato <benato.denis96@gmail.com>
Cc:     Jonathan Cameron <jic23@kernel.org>,
        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
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Hi Denis, Jonathan

On Sun, Oct 1, 2023 at 7:23=E2=80=AFPM Denis Benato <benato.denis96@gmail.c=
om> wrote:
>
> Hello Jagath,
>
> On 9/29/23 09:59, Jagath Jog J wrote:
> > Hi Denis,
> >
> > On Thu, Sep 28, 2023 at 2:55=E2=80=AFAM Denis Benato <benato.denis96@gm=
ail.com> wrote:
> >>
> >> Hello,
> >>
> >> Some devices (as my asus rog ally) have an ACPI node describing a BOSC=
0200 sensor. The IC being used in those devices is a  bmi323 but as a resul=
t 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 I=
D probe.
> >>
> >> The module loaded is bmc150-accel-i2c.c which currently doesn't suppor=
t the bmi323 and the loading of the module just fails at chip check.
> >
> > 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.
>
> I apologize for the confusion.
>
> What I was trying to say is that to have the bmi323 working in those afor=
ementioned devices bmc150 will need to be modified: that is the probe funct=
ion that ends up being executed, fact that cannot be changed because it dep=
ends on the ACPI implementation shipped on those devices.
>
> Therefore I was asking about the best way of handing control to the new d=
river and how that should be organized: in my implementation the new bmi323=
 code was written inside the bmc150-accel-core.c and only shares sleep/susp=
end, probe and removal functions in addition to checking for the new chip p=
resence before checking for any bmc150 chip as that issues an i2c write, wh=
ile the check for the bmi323 only requires an i2c read.

Means you want to handle control to the standalone driver from bmc150.
Sorry, I didn't find any examples.

Important thing to handle is the bmi323 private structure and call required
exported functions from another driver.

Jonathan: Can you suggest any example wrapper drivers which handle that way=
?

>
> We also have done duplicate work as I have written a driver for that chip=
 myself, but it's not as good as yours because my hardware didn't come with=
 the IRQ pin connected and so I couldn't develop triggers and I only got th=
e i2c interface working.
>
> >
> >
> >>
> >> I have solved the problem by expanding the current bmc150-accel-i2c.c =
and bmc150-accel-core.c files to handle that IC in almost every part: gyros=
cope, 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 a=
nother IC and and not just the accelerometer part anymore?
> >>
> >> TIA for your time.
> >>
> >> Best regards,
> >> Denis Benato
> >
> > Regards
> >
> > Jagath
>
> TIA for your time.
>
> Best regards,
> Denis Benato

Regards
Jagath