Am Mittwoch, 7. Januar 2026, 11:04:42 Mitteleuropäische Normalzeit schrieb Chaoyi Chen:

On 1/7/2026 5:57 PM, Chaoyi Chen wrote:

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On 1/7/2026 4:21 PM, Heiko Stübner wrote:

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Am Mittwoch, 7. Januar 2026, 08:56:04 Mitteleuropäische Normalzeit schrieb Alexey Charkov:

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On Wed, Jan 7, 2026 at 11:04 AM Chaoyi Chen [off-list ref] wrote:

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+       vcc3v3_hubreset: vcc3v3-hubreset {
+               compatible = "regulator-fixed";
+               regulator-name = "vcc3v3_hubreset";
+               regulator-boot-on;
+               regulator-always-on;

If this regulator supplies a soldered-on discrete hub and is required
to power it up, won't it be better to describe the hub in the device
tree (see binding at [1]), make the regulator its supply, and perhaps
drop the "regulator-boot-on/regulator-always-on" annotation here,
letting the regulator core deal with its enabling instead?

[1] https://github.com/torvalds/linux/blob/master/Documentation/devicetree/bindings/usb/usb-device.yaml

Yep, it would be nicer to it this way.
A live example can be found in the Rock 5 ITX [2]

[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/arch/arm64/boot/dts/rockchip/rk3588-rock-5-itx.dts#n1266

Thank you for the great example. BTW the hub used here is CH344. It
looks like we need to add a new binding :)

Typo... It is WCH CH334.

I don't think you need a new compatible at all :-) 

When you look at the usb-device.yaml linked above you'll the compatible
already defined as a pattern:

  compatible:
    contains:
      pattern: "^usb[0-9a-f]{1,4},[0-9a-f]{1,4}$"
    description: Device nodes or combined nodes.
      "usbVID,PID", where VID is the vendor id and PID the product id.
      The textual representation of VID and PID shall be in lower case
      hexadecimal with leading zeroes suppressed. The other compatible
      strings from the above standard binding could also be used,
      but a device adhering to this binding may leave out all except
      for "usbVID,PID".

Which will match everything VID + PID combination, so you just need
to use the VID+PID from your hub.


Heiko