Re: [PATCH 8/8] arm64: dts: renesas: salvator: add a connection from adv748x codec (HDMI input) to the R-Car SoC

Kuninori Morimoto
2020-03-09T01:31:05Z

Hi

> > > Those clocks are part of the CSI-2 protocol and also don't need to be
> > > explicitly controlled. As far as I can tell from a quick check of the
> > > ADV7482 documentation, only the I2S MCLK is a general-purpose clock that
> > > needs to be exposed.
(snip)
> > Do you know, by chance, which of the snd_soc* callbacks should be used to
> > implement setting of the MCLK? The one in snd_soc_component_driver or
> > snd_soc_dai_driver->ops (snd_soc_dai_ops)?
> >
> > Or how the userspace interface looks like? Or, if there is no userspace
> > interface for this, how the MCLK is supposed to be set? Through mclk-fs?
>
> I'm afraid my knowledge of the sound subsystem is limited. Morimoto-san
> is the main developer and maintainer of Renesas sound drivers.
> Morimoto-sensei, would you have an answer to that question ? :-)

In my quick check, it goes to AUDIO_CLKC.
If so, you can update rcar_sound::clocks.

&rcar_sound {
...
- /* update <audio_clk_b> to <cs2000> */
+ /* update <audio_clk_b> to <cs2000>,
+ * <audio_clk_c> to <adv748x> */
clocks = <&cpg CPG_MOD 1005>,
...
<&audio_clk_a>, <&cs2000>,
- <&audio_clk_c>,
+ <&adv748x>,
<&cpg CPG_CORE CPG_AUDIO_CLK_I>;

Thank you for your help !!

Best regards
---
Kuninori Morimoto