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

Message ID da7c2a4f469a81d8cdc5c04ab245529a094dbfd3.1552562385.git.jsarha@ti.com
State New
Headers show
Series
  • drm/bridge: sii902x: HDMI-audio support and some fixes
Related show

Commit Message

Jyri Sarha March 14, 2019, 11:27 a.m.
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@ti.com>
---
 .../bindings/display/bridge/sii902x.txt       | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)

Comments

Jyri Sarha March 19, 2019, 2:38 p.m. | #1
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@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

Patch

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.
+	- clocks: phandle and clock specifier for each clock listed in
+          the clock-names property
+	- clock-names: "mclk"
+	    Describes SII902x MCLK input. MCLK is used to produce
+	    HDMI audio CTS values. This property is required if
+	    "i2s-data-lanes"-property is present. This property follows
+	    Documentation/devicetree/bindings/clock/clock-bindings.txt
+	    consumer binding.
+
+	If HDMI audio is configured the sii902x device becomes an ASoC
+	codec component, that can be used in configuring full audio
+	devices with ASoC simple-card or audio-graph-card. See their
+	binding documents on how to describe how the sii902x device is
+	connected to the rest of the audio system:
+	Documentation/devicetree/bindings/sound/simple-card.txt
+	Documentation/devicetree/bindings/sound/audio-graph-card.txt
+
 Optional subnodes:
 	- video input: this subnode can contain a video input port node
 	  to connect the bridge to a display controller output (See this
@@ -21,6 +48,12 @@  Example:
 		compatible = "sil,sii9022";
 		reg = <0x39>;
 		reset-gpios = <&pioA 1 0>;
+
+		#sound-dai-cells = <0>;
+		i2s-data-lanes = < 0 1 2 >;
+		clocks = <&mclk>;
+		clock-names = "mclk";
+
 		ports {
 			#address-cells = <1>;
 			#size-cells = <0>;