[RFC,2/2] ASoC: simple-card: Add documentation for force-dpcm property
diff mbox series

Message ID 20191013190014.32138-3-daniel.baluta@nxp.com
State Changes Requested
Headers show
Series
  • Introduce for-dpcm DT property
Related show

Checks

Context Check Description
robh/checkpatch success

Commit Message

Daniel Baluta Oct. 13, 2019, 7 p.m. UTC
This property can be global in which case all links created will be DPCM
or present in certian dai-link subnode in which case only that specific
link is forced to be DPCM.

Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
---
 Documentation/devicetree/bindings/sound/simple-card.txt | 1 +
 1 file changed, 1 insertion(+)

Comments

Mark Brown Oct. 14, 2019, 11:56 a.m. UTC | #1
On Sun, Oct 13, 2019 at 10:00:14PM +0300, Daniel Baluta wrote:

> This property can be global in which case all links created will be DPCM
> or present in certian dai-link subnode in which case only that specific
> link is forced to be DPCM.

> +- force-dpcm				: Indicates dai-link is always DPCM.

DPCM is an implementation detail of Linux (and one that we want to phase
out going forwards too), we shouldn't be putting it in the DT bindings
where it becomes an ABI.
Daniel Baluta Oct. 14, 2019, 1:17 p.m. UTC | #2
On Mon, Oct 14, 2019 at 2:57 PM Mark Brown <broonie@kernel.org> wrote:
>
> On Sun, Oct 13, 2019 at 10:00:14PM +0300, Daniel Baluta wrote:
>
> > This property can be global in which case all links created will be DPCM
> > or present in certian dai-link subnode in which case only that specific
> > link is forced to be DPCM.
>
> > +- force-dpcm                         : Indicates dai-link is always DPCM.
>
> DPCM is an implementation detail of Linux (and one that we want to phase
> out going forwards too), we shouldn't be putting it in the DT bindings
> where it becomes an ABI.

Hi Mark,

I see your point. This is way I marked the patch series as RFC. I need to find
another way to reuse simple-card as machine driver for SOF.

thanks,
Daniel.
Mark Brown Oct. 14, 2019, 4:10 p.m. UTC | #3
On Mon, Oct 14, 2019 at 04:17:31PM +0300, Daniel Baluta wrote:
> On Mon, Oct 14, 2019 at 2:57 PM Mark Brown <broonie@kernel.org> wrote:

> > DPCM is an implementation detail of Linux (and one that we want to phase
> > out going forwards too), we shouldn't be putting it in the DT bindings
> > where it becomes an ABI.

> I see your point. This is way I marked the patch series as RFC. I need to find
> another way to reuse simple-card as machine driver for SOF.

Have a look at the way the Renesas systems are using this and the audio
graph card - they have DPCM.
Kuninori Morimoto Oct. 15, 2019, 1:02 a.m. UTC | #4
Hi

> > > DPCM is an implementation detail of Linux (and one that we want to phase
> > > out going forwards too), we shouldn't be putting it in the DT bindings
> > > where it becomes an ABI.
> 
> > I see your point. This is way I marked the patch series as RFC. I need to find
> > another way to reuse simple-card as machine driver for SOF.
> 
> Have a look at the way the Renesas systems are using this and the audio
> graph card - they have DPCM.

Indeed we (= Renesas) are using this as DPCM, but unfortunately
it is not upstreamed. Using local patch.

Thank you for your help !!
Best regards
---
Kuninori Morimoto
Kuninori Morimoto Oct. 15, 2019, 1:18 a.m. UTC | #5
Hi

> > > > DPCM is an implementation detail of Linux (and one that we want to phase
> > > > out going forwards too), we shouldn't be putting it in the DT bindings
> > > > where it becomes an ABI.
> > 
> > > I see your point. This is way I marked the patch series as RFC. I need to find
> > > another way to reuse simple-card as machine driver for SOF.
> > 
> > Have a look at the way the Renesas systems are using this and the audio
> > graph card - they have DPCM.
> 
> Indeed we (= Renesas) are using this as DPCM, but unfortunately
> it is not upstreamed. Using local patch.

I mean DT part.

Thank you for your help !!
Best regards
---
Kuninori Morimoto

Patch
diff mbox series

diff --git a/Documentation/devicetree/bindings/sound/simple-card.txt b/Documentation/devicetree/bindings/sound/simple-card.txt
index 79954cd6e37b..15e6f5329857 100644
--- a/Documentation/devicetree/bindings/sound/simple-card.txt
+++ b/Documentation/devicetree/bindings/sound/simple-card.txt
@@ -63,6 +63,7 @@  Optional dai-link subnode properties:
 - mclk-fs             			: Multiplication factor between stream
 					  rate and codec mclk, applied only for
 					  the dai-link.
+- force-dpcm				: Indicates dai-link is always DPCM.
 
 For backward compatibility the frame-master and bitclock-master
 properties can be used as booleans in codec subnode to indicate if the