Re: [PATCH v2 2/3] arm64: dts: exynos: ExynosAutov920: Add regulators for the USB

[Krzysztof Kozlowski]

On 18/02/2026 10:28, pritam.sutar@xxxxxxxxxxx wrote:
>>>>> +	usbdrd31_dwc3_vbus: usbdrd31_dwc3-vbus {
>>>>
>>>> Please use name for all fixed regulators which matches current format
>>>> recommendation: 'regulator-[0-9]v[0-9]'
>>>>
>>>> https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.gi
>>>> t/tree/
>>>> Documentation/devicetree/bindings/regulator/fixed-regulator.yaml
>>>>
>>>> None of the regulators are called like you wrote. Really NONE.
>>>>
>>>
>>> Thank you for the references. Will bring changes for regulator's name
>>> and labels as
>>>
>>> -       usbdrd31_dwc3_vbus: usbdrd31_dwc3-vbus {
>>> +       reg_usbdrd31_dwc3_vbus: regulator-1 {
>>
>> Did you read the binding? That's not what I asked.
>>
> 
> Yes. 
> Sorry for misinterpreting above comment. Is it expected as below?
> 
> This is based on our understanding by referring binding and other vendor dts.
> 
> --- a/arch/arm64/boot/dts/exynos/exynosautov920-sadk.dts
> +++ b/arch/arm64/boot/dts/exynos/exynosautov920-sadk.dts
> @@ -59,7 +59,7 @@ dummy_regulator: regulator-0 {
>                  regulator-name = "dummy_regulator";
>         };
> 
> -       usbdrd31_dwc3_vbus: usbdrd31_dwc3-vbus {
> +       reg_usb_vbus0: regulator-5v0-vbus0 {

Yes, that's better.

Only under the assumption these are actually dedicated single-enable-pin
regulators, not pins going to the PMIC.

>                compatible = "regulator-fixed";
>                regulator-name = "usbdrd31_dwc3-vbus";
>                regulator-min-microvolt = <5000000>;
> @@ -75,7 +75,7 @@ usb_phy0: usb-phy0 {
>                 vbus-supply = <&usbdrd31_dwc3_vbus>;
>         };
> 

...

>>>>
>>>> That's a bit too much of dummies. This is heavily incomplete. You
>>>> need to bring back the PMIC first.
>>>>
>>>
>>> Presently, relying on USB LDOs being enabled by the bootloader in this
>>> automotive SoC. However, we understand the concern and it is added in
>>> case if anyone wants to use implemented PMIC in future. For now, would
>>> like to proceed with the dummy regulators to enable the required USB
>> features.
>>
>> And I don't see the point of these dummies. Solves nothing.
>>
> 
> Are you expecting details as mentioned in above section in commit message? 
> However, we have mentioned these details in cover letter.

No, I am expecting proper PMIC to be represented here. One dummy
regulator during the fast development phase is okay. Dummy added by
community contributors without resources and schematics would also fly.

But Samsung, with all the resources, schematics doing development since
2023 and still adding 20 dummies to every device? Nope, no, sorry.

Please start doing this properly. Look how entire new SoC was upstreamed
by Linaro:
https://lore.kernel.org/all/20231121-topic-sm8650-upstream-dt-v3-0-db9d0507ffd3@xxxxxxxxxx/

Or something newer by Qualcomm:
https://lore.kernel.org/linux-arm-msm/?q=s%3Aglymur


Best regards,
Krzysztof