Re: [PATCH 1/3] ASoC: simple-card-utils: Fix device module clock

[Michael Walle]

Am 2021-03-12 12:35, schrieb Mark Brown:
> On Thu, Mar 11, 2021 at 11:11:15PM +0100, Michael Walle wrote:
> > Am 2021-03-11 17:15, schrieb Mark Brown:
>
> > > The trick is figuring out if it's best to vary the input clock
> > > or to use the FLL to adapt a fixed input clock,
>
> > For simple-audio-card you can set the "clock" property if you want
> > that clock to be changed/enabled/disabled. But that doesn't seem to
> > be the way to go, at least it was NAKed by Rob for the 
> > audio-graph-card.
> > I don't see a way to figure out if MCLK should be controlled by
> > simple-*-card without adding further properties to the device tree.
>
> If the card has a clock API clock as sysclk then set_sysclk(() should
> be configuring that clock.

What do you mean by "the card". The simple-audio-card itself?

Take a look at:
https://elixir.bootlin.com/linux/v5.12-rc2/source/arch/arm64/boot/dts/freescale/fsl-ls1028a-kontron-sl28-var3-ads2.dts#L29

Does the card has a clock? IMHO the WM8904 codec has a clock, but not
the audio card.

-michael