Re: [PATCH] iio: dac: ad5593r: Dynamically set AD5593R channel modes

From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: AceLan Kao <acelan.kao@canonical.com>
Cc: Alexandru Ardelean <alexandru.ardelean@analog.com>,
	William Sung <william.sung@advantech.com.tw>,
	Lars-Peter Clausen <lars@metafoo.de>,
	Michael Hennerich <Michael.Hennerich@analog.com>,
	Jonathan Cameron <jic23@kernel.org>,
	Hartmut Knaack <knaack.h@gmx.de>,
	Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
	linux-iio <linux-iio@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Campion Kang <Campion.Kang@advantech.com.tw>
Subject: Re: [PATCH] iio: dac: ad5593r: Dynamically set AD5593R channel modes
Date: Thu, 3 Sep 2020 13:54:07 +0300	[thread overview]
Message-ID: <CAHp75VcJp4zCxOUBgYTypv_R47vLAuAF2ZStLpA9mjFjbzWcxw@mail.gmail.com> (raw)
In-Reply-To: <CAHp75Vc6fgPmnPOYYvUi7EO7ovq2tLk_kBqqk-=wrr0V3nbcVw@mail.gmail.com>

On Thu, Sep 3, 2020 at 1:42 PM Andy Shevchenko
<andy.shevchenko@gmail.com> wrote:
> On Thu, Sep 3, 2020 at 10:37 AM AceLan Kao <acelan.kao@canonical.com> wrote:

Couple additional notes.

...

> > I spent some time studying/reading what you wrote, but I still don't
> > understand how to leverage meta-acpi.
>
> meta-acpi is a Yocto layer to support provided ACPI tables for the
> build. My point here is to have it as a collection of ASL examples.
> It's what you asked for below in this email.

> Also we can collect your ASL example under board (presumably new) folder.

Actually it seems Baytrail, so, minnowboard-max is good enough.

...

> On the first glance I didn't see any issues with it, but on second
> look here is one. Look into this [5] example.
> If you noticed it uses the same path in Scope and in the reference in
> I2cSerialBus() while in your ASL they are different.

Also there is an _ADR value wrong for the second channel (I'm not sure
if it affects anyhow the rest).

> Do you have issues with loading it (as is and after above addressed)?
>
> [5]: https://github.com/westeri/meta-acpi/blob/master/recipes-bsp/acpi-tables/samples/edison/ft6236.asli

Also a link [6] to our Buildroot repository which allows to create an
initramfs with ASL compiled. Maybe used as a reference how we created
initramfs and compile ASLs.

[6]: https://github.com/andy-shev/buildroot/tree/intel/board/intel/common
...

> > > One more useful link is SO answers on the topic:
> > > https://stackoverflow.com/search?tab=newest&q=prp0001
> > >
> > > > [1]: https://www.kernel.org/doc/html/latest/firmware-guide/acpi/enumeration.html#device-tree-namespace-link-device-id
> > > > [2]: https://elixir.bootlin.com/linux/v5.9-rc3/source/Documentation/devicetree/bindings/iio/dac/ad5592r.txt
> > > > [3]: https://github.com/westeri/meta-acpi
> > > > [4]: https://github.com/westeri/meta-acpi/tree/master/recipes-bsp/acpi-tables/samples

> > > > > 1. https://www.advantech.com/products/9a0cc561-8fc2-4e22-969c-9df90a3952b5/uno-420/mod_2d6a546b-39e3-4bc4-bbf4-ac89e6b7667c

-- 
With Best Regards,
Andy Shevchenko