Re: [PATCH 2/2] arm64: dts: qcom: sm8750-mtp: Add sound (speakers, headset codec, dmics)

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 25/04/2025 11:30, Konrad Dybcio wrote:
> On 4/24/25 11:40 AM, Krzysztof Kozlowski wrote:
>> Add device nodes for most of the sound support - WSA883x smart speakers,
>> WCD9395 audio codec (headset) and sound card - which allows sound
>> playback via speakers and recording via DMIC microphones.  Changes bring
>> necessary foundation for headset playback/recording via USB, but that
>> part is not yet ready.
>>
>> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> ---
> 
> [...]
> 
>> +	sound {
>> +		compatible = "qcom,sm8750-sndcard", "qcom,sm8450-sndcard";
>> +		model = "SM8750-MTP";
>> +		audio-routing = "SpkrLeft IN", "WSA_SPK1 OUT",
>> +				"SpkrRight IN", "WSA_SPK2 OUT",
>> +				"IN1_HPHL", "HPHL_OUT",
>> +				"IN2_HPHR", "HPHR_OUT",
>> +				"AMIC2", "MIC BIAS2",
>> +				"VA DMIC0", "MIC BIAS3", /* MIC4 on schematics */
>> +				"VA DMIC1", "MIC BIAS3", /* MIC1 on schematics */
> 
> Is this a mistake in what the codec driver exposes, or just a fumble
> in numbering $somewhere?

Which mistake? MIC4? Schematics call name things differently. They
always were, so to make it clear for people without schematics I wrote
which MIC it actually is.

> 
>> +				"VA DMIC2", "MIC BIAS1",
>> +				"VA DMIC3", "MIC BIAS1",
>> +				"VA DMIC0", "VA MIC BIAS3",
>> +				"VA DMIC1", "VA MIC BIAS3",
>> +				"VA DMIC2", "VA MIC BIAS1",
>> +				"VA DMIC3", "VA MIC BIAS1",
>> +				"TX SWR_INPUT1", "ADC2_OUTPUT";
>> +
>> +		wcd-playback-dai-link {
>> +			link-name = "WCD Playback";
>> +
>> +			cpu {
>> +				sound-dai = <&q6apmbedai RX_CODEC_DMA_RX_0>;
>> +			};
>> +
>> +			codec {
> 
> 'co'dec < 'cp'u
> 
> [...]

That was the convention so far, but we can start a new one, sure. Just
ask the same all other patch contributors, because each of them will be
copying old code, which means cpu->codec->platform

> 
>> +		/*
>> +		 * WCD9395 RX Port 1 (HPH_L/R)      <=> SWR1 Port 1 (HPH_L/R)
>> +		 * WCD9395 RX Port 2 (CLSH)         <=> SWR1 Port 2 (CLSH)
>> +		 * WCD9395 RX Port 3 (COMP_L/R)     <=> SWR1 Port 3 (COMP_L/R)
>> +		 * WCD9395 RX Port 4 (LO)           <=> SWR1 Port 4 (LO)
>> +		 * WCD9395 RX Port 5 (DSD_L/R)      <=> SWR1 Port 5 (DSD_L/R)
>> +		 * WCD9395 RX Port 6 (HIFI_PCM_L/R) <=> SWR1 Port 9 (HIFI_PCM_L/R)
>> +		 */
>> +		qcom,rx-port-mapping = <1 2 3 4 5 9>;
> 
> Does this deserve some dt-bindings constants?

No, because these are hardware details/constants. Drivers do not use them.

Best regards,
Krzysztof