[PATCH v4 5/6] dt-bindings: display: sii902x: Add HDMI audio bindings

[Jyri Sarha]

On 17/03/2019 18:16, Laurent Pinchart wrote:
> Hi Jyri,
> 
> Thank you for the patch.
> 
> On Thu, Mar 14, 2019 at 01:27:51PM +0200, Jyri Sarha wrote:
>> The sii902x chip family supports also HDMI audio. Add binding for
>> describing the necessary i2s and mclk wiring for it.
>>
>> Signed-off-by: Jyri Sarha <jsarha at ti.com>
>> ---
>>  .../bindings/display/bridge/sii902x.txt       | 33 +++++++++++++++++++
>>  1 file changed, 33 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/display/bridge/sii902x.txt b/Documentation/devicetree/bindings/display/bridge/sii902x.txt
>> index c4c1855ca654..1a37bbe7c597 100644
>> --- a/Documentation/devicetree/bindings/display/bridge/sii902x.txt
>> +++ b/Documentation/devicetree/bindings/display/bridge/sii902x.txt
>> @@ -9,6 +9,33 @@ Optional properties:
>>  	  about hotplug events.
>>  	- reset-gpios: OF device-tree gpio specification for RST_N pin.
>>  
>> +	HDMI audio properties:
>> +	- i2s-data-lanes: Array of up to 4 integers with values of 0-3
>> +	   Each integer indicates which i2s pin is connected to which
>> +	   audio fifo. The first integer selects i2s audio pin for the
>> +	   first audio fifo#0 (HDMI channels 1&2), second for fifo#1
>> +	   (HDMI channels 3&4), and so on. There is 4 fifos and 4 i2s
>> +	   pins (SD0 - SD3). Any i2s pin can be connected to any fifo,
>> +	   but there can be no gaps. E.g. an i2s pin must be mapped to
>> +	   fifo#0 and fifo#1 before mapping a channel to fifo#2.
>> +	   I2S HDMI audio is configured only if this property is found.
> This looks good to me, but shouldn't the property be defined somewhere
> in Documentation/devicetree/bindings/sound/ ? The sound bindings seem to
> be a bit messy though, with little common or high-level documentation,
> so I don't want to ask you to fix all that :-) Maybe just adding a
> common-i2s.txt file there would be enough ? 
> 
> Apart from this the rest looks good to me, but I'd appreciate if it
> could be reviewed by audio people.
> 
When I think about this property, it hardly is a generic enough to for
all i2s devices or even codecs. That would probably require gaps in the
i2s-data-lane order. I would not want to create common-i2s.txt just for
this property. The is some many other properties that should be added
there first. Maybe this should be made vendor specific property after all.

I think I make a resend with alsa-devel included.

Best regards,
Jyri

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