[PATCH v2 5/5] ARM: dts: r8a7794: add sound support

[horms@verge.net.au (Simon Horman)]

On Fri, Feb 12, 2016 at 10:08:54PM +0300, Sergei Shtylyov wrote:
> On 02/12/2016 09:43 PM, Simon Horman wrote:
> 
> >>>>Sorry for my un-ordered response
> >>>>
> >>>>>Define the generic R8A7794 part of  the sound device node.
> >>>>>This sound device  is a complex one and comprises the Audio Clock Generator
> >>>>>(ADG), Sampling Rate Converter Unit (SCU), Serial Sound Interface [Unit]
> >>>>>(SSI[U]), and Audio DMAC-Peripheral-Peripheral.
> >>>>>It is up  to the board file to enable the device.
> >>>>>
> >>>>>This patch is based on the R8A7791 sound work by Kuninori Morimoto.
> >>>>>
> >>>>>Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
> >>>>(snip)
> >>>>>+		rcar_sound,src {
> >>>>>+			src1: src at 1 {
> >>>>>+				interrupts = <GIC_SPI 353 IRQ_TYPE_LEVEL_HIGH>;
> >>>>>+				dmas = <&audma0 0x87>, <&audma0 0x9c>;
> >>>>>+				dma-names = "rx", "tx";
> >>>>>+			};
> >>>>>+			src2: src at 2 {
> >>>>>+				interrupts = <GIC_SPI 354 IRQ_TYPE_LEVEL_HIGH>;
> >>>>>+				dmas = <&audma0 0x89>, <&audma0 0x9e>;
> >>>>>+				dma-names = "rx", "tx";
> >>>>>+			};
> >>>>>+			src3: src at 3 {
> >>>>>+				interrupts = <GIC_SPI 355 IRQ_TYPE_LEVEL_HIGH>;
> >>>>>+				dmas = <&audma0 0x8b>, <&audma0 0xa0>;
> >>>>>+				dma-names = "rx", "tx";
> >>>>>+			};
> >>>>>+			src4: src at 4 {
> >>>>>+				interrupts = <GIC_SPI 356 IRQ_TYPE_LEVEL_HIGH>;
> >>>>>+				dmas = <&audma0 0x8d>, <&audma0 0xb0>;
> >>>>>+				dma-names = "rx", "tx";
> >>>>>+			};
> >>>>>+			src5: src at 5 {
> >>>>>+				interrupts = <GIC_SPI 357 IRQ_TYPE_LEVEL_HIGH>;
> >>>>>+				dmas = <&audma0 0x8f>, <&audma0 0xb2>;
> >>>>>+				dma-names = "rx", "tx";
> >>>>>+			};
> >>>>>+			src6: src at 6 {
> >>>>>+				interrupts = <GIC_SPI 358 IRQ_TYPE_LEVEL_HIGH>;
> >>>>>+				dmas = <&audma0 0x91>, <&audma0 0xb4>;
> >>>>>+				dma-names = "rx", "tx";
> >>>>>+			};
> >>>>>+		};
> >>>>
> >>>>I think this can't work correctly, because driver is assuming
> >>>>DT has all channles (from 0). (see linux/sound/soc/sh/rcar/src.c :: rsnd_src_probe)
> >>>>Can you adds dummy src0 with some comments ? or fix src.c driver ?
> >>>
> >>>I would prefer the driver to be fixed (I had a similar patchset locally
> >>>and I found it doesn't work).
> >>
> >>    You mean you had R8A7794 sound patch set too?
> >
> >Yes, I was working on it recently.
> >I suppose we should coordinate these things in future to avoid
> >duplicated effort.
> 
>    Yes, seems a good idea now. :-)
> 
> >>>The reason is that DT should describe
> >>>the hardware rather than the current state of the software.
> >>
> >>    Yes, of course. Just tell me do I have to fix the driver *before* this
> >>patch set is accepted?
> 
> >I did not entirely get to the bottom of the problem, but I think that at
> >the very least something needs to be done about the for_each_rsnd_src()
> >loop in rsnd_src_probe.
> 
>    It's not that it replies to my question. :-)
>    So you're looking at this issue yourself?

I have not got very far, as you can see, but I was planning to look into it.
I don't mind if you want to do so.

> >My, obviously not satisfactory, hack around there being no src0 was as follows.
> >
> >diff --git a/sound/soc/sh/rcar/src.c b/sound/soc/sh/rcar/src.c
> >index 68b439ed22d7..58a447b0785b 100644
> >--- a/sound/soc/sh/rcar/src.c
> >+++ b/sound/soc/sh/rcar/src.c
> >@@ -1072,7 +1072,7 @@ int rsnd_src_probe(struct platform_device *pdev,
> >
> >  	for_each_rsnd_src(src, priv, i) {
> 
>    Which tree is this? The recent devel branch of renesas.git has
> for_each_child_of_node() here...

renesas-devel-20160118-v4.4

I guess the code in question updated in v4.5-rcX.

> >  		snprintf(name, RSND_SRC_NAME_SIZE, "%s.%d",
> >-			 SRC_NAME, i);
> >+			 SRC_NAME, i + 1);
> >
> >  		clk = devm_clk_get(dev, name);
> >  		if (IS_ERR(clk))
> 
> MBR, Sergei