Re: [PATCH v3 1/3] dt-bindings: usb: Add binding for WCH CH334/CH335 hub controller

[Chaoyi Chen <chaoyi.chen@rock-chips.com>]

Hi Krzysztof,

On 1/12/2026 4:50 PM, Krzysztof Kozlowski wrote:
> On Mon, Jan 12, 2026 at 10:28:21AM +0800, Chaoyi Chen wrote:
>> From: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>>
>> The WCH CH334/CH335[0] are USB2.0 protocol compliant 4-port USB HUB
>> controller chips, supporting USB2.0 high-speed and full-speed for
>> upstream ports, and USB2.0 high-speed 480Mbps, full-speed 12Mbps and
>> low-speed 1.5Mbps for downstream ports, supporting not only low-cost STT
>> mode (single TT schedules 4 downstream ports in time share), but also
>> supports high performance MTT mode (4 TTs each corresponding to 1 port,
>> concurrent processing).
>>
>> Add a device tree binding for it.
>>
>> [0]: https://www.wch-ic.com/downloads/CH334DS1_PDF.html
>>
>> Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com>
>> ---
>>  .../devicetree/bindings/usb/wch,ch334.yaml    | 65 +++++++++++++++++++
> 
> This must be separate patch. Do not combine independent subsystems into
> one patchset.
> 

Okay, thank you for the reminder.

>>  1 file changed, 65 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/usb/wch,ch334.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/usb/wch,ch334.yaml b/Documentation/devicetree/bindings/usb/wch,ch334.yaml
>> new file mode 100644
>> index 000000000000..2eeb92f25b4c
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/usb/wch,ch334.yaml
>> @@ -0,0 +1,65 @@
>> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/usb/wch,ch334.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: WCH CH334/CH335 USB 2.0 Hub Controller
>> +
>> +maintainers:
>> +  - Chaoyi Chen <kernel@airkyi.com>
>> +
>> +allOf:
>> +  - $ref: usb-hub.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    enum:
>> +      - usb1a86,8091
>> +
>> +  reg: true
>> +
>> +  reset-gpios:
>> +    description: GPIO controlling the RESET# pin.
>> +
>> +  vdd-supply:
>> +    description:
>> +      The regulator that provides 3.3V core power to the hub.
>> +
>> +  vdd2-supply:
>> +    description:
>> +      The regulator that provides 3.3V or 5V power to the hub.
>> +
>> +  ports:
>> +    $ref: /schemas/graph.yaml#/properties/ports
>> +
>> +    patternProperties:
>> +      '^port@':
>> +        $ref: /schemas/graph.yaml#/properties/port
>> +
>> +        properties:
>> +          reg:
>> +            minimum: 1
>> +            maximum: 4
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +
>> +additionalProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/gpio/gpio.h>
>> +    usb {
>> +        dr_mode = "host";
>> +        #address-cells = <1>;
>> +        #size-cells = <0>;
>> +
>> +        hub: hub@1 {
>> +            compatible = "usb1a86,8091";
>> +            reg = <1>;
>> +            reset-gpios = <&gpio0 2 GPIO_ACTIVE_HIGH>;
> 
> Are you sure?

I guess what you're concerned about here is the polarity? 
If that's the case, then there's no problem.

-- 
Best, 
Chaoyi