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From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Tue, 9 Mar 2021 13:46:55 +0200
Message-ID: <CAHp75VfR2_N=krD8Rady77ST19o5vL7zChLnJ32wmx-+M1N3pg@mail.gmail.com>
Subject: Re: [PATCH v1 2/2] iio: adc: add ADC driver for the TI TSC2046 controller
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Rob Herring <robh+dt@kernel.org>,
        Jonathan Cameron <jic23@kernel.org>,
        devicetree <devicetree@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        David Jander <david@protonic.nl>,
        Robin van der Gracht <robin@protonic.nl>,
        linux-iio <linux-iio@vger.kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>
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On Tue, Mar 9, 2021 at 1:42 PM Oleksij Rempel <o.rempel@pengutronix.de> wrote:
> On Tue, Mar 09, 2021 at 01:05:27PM +0200, Andy Shevchenko wrote:
> > On Fri, Mar 5, 2021 at 9:05 PM Jonathan Cameron
> > <Jonathan.Cameron@huawei.com> wrote:
> > >
> > > On Fri, 5 Mar 2021 14:38:13 +0100
> > > Oleksij Rempel <o.rempel@pengutronix.de> wrote:
> > >
> > > > Basically the TI TSC2046 touchscreen controller is 8 channel ADC optimized for
> > > > the touchscreen use case. By implementing it as IIO ADC device, we can
> > > > make use of resistive-adc-touch and iio-hwmon drivers.
> > > >
> > > > So far, this driver was tested with custom version of resistive-adc-touch driver,
> > > > since it need to be extended to make use of Z1 and Z2 channels. The X/Y
> > > > are working without additional changes.
> > > >
> > > > Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> > >
> > > Hi Oleksij,
> > >
> > > To consider this as a possible long term route instead of just making this
> > > a touchscreen driver, we'll want to see those mods to the resistive-adc-touch.
> > > Of course that doesn't stop review of this in the meantime.
> > >
> > > There are quite a few things in here that feel pretty specific to the touchscreen
> > > usecase. That makes me wonder if this is a sensible approach or not.
> >
> > I'm wondering if this has any similarities with existing drivers under
> > drivers/input/touchscreen.
>
> Yes, for example: drivers/input/touchscreen/ads7846.c

Then I have a few questions here:
1/ why the above mentioned driver can't be extended to cover this?
2/ or why is the proposed driver named after the touchscreen instead
of the real AD/C chip behind it?
3/ maybe we can introduce a simple AD/C driver under IIO for that?


-- 
With Best Regards,
Andy Shevchenko