Re: [PATCH v1 2/2] arm64: dts: qcom: eliza-cqs-evk: Enable sound card support with WSA8845 and DMIC

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 7/8/26 1:27 PM, Ravi Hothi wrote:
> 
> 
> On 7/7/2026 2:11 PM, Konrad Dybcio wrote:
>> On 7/1/26 7:43 PM, Ravi Hothi wrote:
>>> Enable the sound card on the Eliza CQS EVK platform, including the
>>> WSA8845 external speaker path and DMIC microphone capture via VA macro.
>>>
>>> Enable the required LPASS WSA macro, VA macro and SoundWire controller
>>> along with the necessary pinctrl configurations for DMIC and WSA
>>> SoundWire interfaces.
>>>
>>> Signed-off-by: Ravi Hothi <ravi.hothi@oss.qualcomm.com>
>>> ---

[...]

>>> +&pm7550_gpios {
>>> +    dmic-eldo-en-hog {
>>> +        gpio-hog;
>>> +        gpios = <7 GPIO_ACTIVE_HIGH>;
>>> +        output-high;
>>> +        line-name = "dmic-eldo-en";
>>> +    };
>>
>> Why add a hog if you defined the regulator already?
>>
>> Konrad
>>
> 
> The gpio-hog is the mechanism that actually drives PM7550 GPIO8 high at boot to enable the ELDO hardware. This GPIO enable is required to enable the ELDO regulator which is powering the MIC BIAS supply.
> The regulator-fixed driver with empty fixed_voltage_ops has no .enable()/.disable() callbacks — it cannot toggle the GPIO. The dmic_eldo regulator node is needed to correctly describe the supply chain to the VA macro driver (vdd-micb-supply) and for power tracking, but it cannot control the GPIO itself. Both are needed for different purposes.

Well, why do you think the binding would accept the GPIO if it
couldn't be controlled? Of course it can power it on/off, check
regulator core code

Konrad