Re: [PATCH v1 1/4] arm64: dts: ti: k3-am62x: Enable AUDIO_REFCLKx

[Jai Luthra]

Hi Nishanth, Francesco,

On Aug 02, 2023 at 09:00:20 -0500, Nishanth Menon wrote:
> On 15:41-20230802, Francesco Dolcini wrote:
> > 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@xxxxxx> ha scritto:
> > > > >On Jul 31, 2023 at 16:21:32 +0200, Francesco Dolcini wrote:
> > > > >> From: Jai Luthra <j-luthra@xxxxxx>
> > > > >> 
> > > > >> 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@xxxxxx>
> > > > >> Signed-off-by: Francesco Dolcini <francesco.dolcini@xxxxxxxxxxx>
> > > > >> ---
> > > > >>  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).
> 
> Jai: This sounds sane to me, if you are OK as well, I'd appreciate a reviewed-by
> 

Makes sense, most external peripherals would prefer that default PLL as 
parent - for other usecases what Francesco said can work.

Reviewed-by: Jai Luthra <j-luthra@xxxxxx>

> > 
> > > (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 ;-)
> 
> hehe ;)
> 
> -- 
> Regards,
> Nishanth Menon
> Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3  1A34 DDB5 849D 1736 249D
> 

-- 
Thanks,
Jai

GPG Fingerprint: 4DE0 D818 E5D5 75E8 D45A AFC5 43DE 91F9 249A 7145

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