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Date:   Wed, 2 Aug 2023 15:41:03 +0200
From:   Francesco Dolcini <francesco@dolcini.it>
To:     Nishanth Menon <nm@ti.com>
Cc:     Francesco Dolcini <francesco@dolcini.it>,
        Jai Luthra <j-luthra@ti.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Tero Kristo <kristo@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Francesco Dolcini <francesco.dolcini@toradex.com>
Subject: Re: [PATCH v1 1/4] arm64: dts: ti: k3-am62x: Enable AUDIO_REFCLKx
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On Wed, Aug 02, 2023 at 08:32:44AM -0500, Nishanth Menon wrote:
> On 13:37-20230802, Francesco Dolcini wrote:
> > Il 2 agosto 2023 13:23:50 CEST, Jai Luthra <j-luthra@ti.com> ha scritto:
> > >On Jul 31, 2023 at 16:21:32 +0200, Francesco Dolcini wrote:
> > >> From: Jai Luthra <j-luthra@ti.com>
> > >> 
> > >> On AM62-based SoCs the AUDIO_REFCLKx clocks can be used as an input to
> > >> external peripherals when configured through CTRL_MMR, so add the
> > >> clock nodes.
> > >> 
> > >> Signed-off-by: Jai Luthra <j-luthra@ti.com>
> > >> Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
> > >> ---
> > >>  arch/arm64/boot/dts/ti/k3-am62-main.dtsi  | 18 ++++++++++++++++++
> > >>  arch/arm64/boot/dts/ti/k3-am62a-main.dtsi | 18 ++++++++++++++++++
> > >
> > >Given currently none of the AM62A boards are using the refclks, can you 
> > >drop those or just mark the nodes as disabled. Whoever is the first user 
> > >can enable them.
> > 
> > I can drop the 2 clocks from AM62A, however, should we really do it?
> > These clocks exist and they are just defined in the DTS, they are
> > not going to be enabled if not used, "ti,am62-epwm-tbclk" is also
> > not disabled for example.
> 
> Overall, the SoC clock as such has nothing to do with board specific, so
> leave it default (enabled) in SoC.dts - just want to make sure that the
> clk-parent selection doesn't get in the way of platforms and is a sane
> default.

When I looked into that, months ago, this looked to me the correct and a
sane default. I had the same in our downstream way before the addition
from Jai Luthra to the SoC dtsi.

Not sure if Jai can add more on that regard.

> pll2_hsdiv8 output - which looks like the default mux value anyways..
> I am ok for it being explicit, but wondering if that works for boards
> that do not use this default.

IFF needed, it would be very easy to just override from the board dts,
using the labels that are already there (audio_refclk0, audio_refclk1).

> (sidenote): Fransesco - your new mail client has line wrap issues ;)
Yep, I had the crazy idea to reply from my mobile phone while having a
walk. It's already a success that I did not top post ;-)

Francesco