Thread (23 messages) 23 messages, 3 authors, 2026-03-04

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

From: Krzysztof Kozlowski <krzk@kernel.org>
Date: 2026-02-18 19:54:27
Also in: linux-arm-kernel, linux-samsung-soc, lkml

On 18/02/2026 10:28, pritam.sutar@samsung.com wrote:
quoted hunk ↗ jump to hunk
quoted
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+	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.
quoted hunk ↗ jump to hunk
               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>;
        };
...
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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@linaro.org/ (local)

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


Best regards,
Krzysztof
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