Re: [PATCH RFC 4/6] sm8650-hdk: Enable I2S for HDMI

[Neil Armstrong <neil.armstrong@linaro.org>]

On 10/7/25 03:39, Alexey Klimov wrote:
> On Mon Oct 6, 2025 at 7:37 PM BST, Neil Armstrong wrote:
>> Add the necessary nodes to configure the right I2S interface
>> to output audio via the DSI HDMI bridge.
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   arch/arm64/boot/dts/qcom/sm8650-hdk.dts | 30 +++++++++++++++++++++++++
>>   arch/arm64/boot/dts/qcom/sm8650.dtsi    | 40 +++++++++++++++++++++++++++++++++
>>   2 files changed, 70 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/qcom/sm8650-hdk.dts b/arch/arm64/boot/dts/qcom/sm8650-hdk.dts
>> index 87d7190dc991b11f5d1162aabb693dcadd198c51..1286ce95235d5544322a1877292cbdd426298c11 100644
>> --- a/arch/arm64/boot/dts/qcom/sm8650-hdk.dts
>> +++ b/arch/arm64/boot/dts/qcom/sm8650-hdk.dts
>> @@ -171,6 +171,19 @@ sound {
>>   				"TX SWR_INPUT1", "ADC2_OUTPUT",
>>   				"TX SWR_INPUT3", "ADC4_OUTPUT";
>>   
>> +		pinctrl-0 = <&i2s0_default_state>, <&audio_mclk0_default_state>;
>> +		pinctrl-names = "default";
>> +
>> +		clocks = <&q6prmcc LPASS_CLK_ID_PRI_MI2S_IBIT LPASS_CLK_ATTRIBUTE_COUPLE_NO>,
>> +			 <&q6prmcc LPASS_CLK_ID_MCLK_1 LPASS_CLK_ATTRIBUTE_COUPLE_NO>;
>> +		clock-names = "pri-mi2s",
>> +			      "pri-mclk";
>> +
>> +		assigned-clocks = <&q6prmcc LPASS_CLK_ID_PRI_MI2S_IBIT LPASS_CLK_ATTRIBUTE_COUPLE_NO>,
>> +				  <&q6prmcc LPASS_CLK_ID_MCLK_1 LPASS_CLK_ATTRIBUTE_COUPLE_NO>;
>> +		assigned-clock-rates = <1536000>,
>> +				       <24576000>;
>> +
>>   		wcd-playback-dai-link {
>>   			link-name = "WCD Playback";
>>   
>> @@ -218,6 +231,22 @@ platform {
>>   				sound-dai = <&q6apm>;
>>   			};
>>   		};
>> +
>> +		pri-mi2s-dai-link {
>> +			link-name = "Primary MI2S Playback";
> 
> Is it HDMI only audio playback or does it have switches to playback it as raw i2s
> (when external DAC is needed)?

The HDK has i2s lines of the secondary i2s on the LS connector, but without any additional
boards connected it has no on-board i2s dacs.

Neil

> 
> 
>> +			cpu {
>> +				sound-dai = <&q6apmbedai PRIMARY_MI2S_RX>;
>> +			};
>> +
>> +			codec {
>> +				sound-dai = <&lt9611_codec 0>;
>> +			};
>> +
>> +			platform {
>> +				sound-dai = <&q6apm>;
>> +			};
>> +		};
>>   	};
> 
> [..]
> 
> Best regards,
> Alexey