Re: [PATCH 6/7] ARM: dts: Add dts for Raspberry Pi 4 + Cirrus Logic Lochnagar2

[Richard Fitzgerald]

On 15/10/2020 16:12, Nicolas Saenz Julienne wrote:
> On Thu, 2020-10-15 at 12:14 +0100, Richard Fitzgerald wrote:
> > > Sadly I don't think creating a new device tree is a good solution here. If we
> > > were to do so for every RPi hat/usage it'd become unmanageable very fast. There
> > > is a way to maintain this in the open nonetheless. I suggest you build a DT
> > > overlay and submit it to https://github.com/raspberrypi/linux, see
> > > 'arch/arm/boot/dts/overlays.' The Raspberry Pi engineers have a kernel branch
> >
> > We want something in mainline so that it can be used by people
> > developing on mainline and taken as a starting point for configuring
> > the codecs for other host platforms. The RPi is a convenient platform to
> > use as the base because it is widely available and low-cost.
>
> If what you want to convey is the proper way of configuring your specific
> device the way to go is writing a devicetree binding. See

If we have a working configuration it is unreasonable not to make this
available for people who want to use it or examine it. A working example
can be more helpful than a ton of documentation.

It's also worth noting that setting up a working sound system involves
configuring multiple drivers (for example you also need a properly
configured ASoC machine driver at least) crossing multiple driver
bindings. So a complete working example is valuable to see how
it fits together.

> Documentation/devicetree. It's even possible to validate a given devicetree
> against the bindings (given they are written in yaml format).

Validating only checks syntax and bounds. It doesn't prove that it will
work.

> Regards,
> Nicolas