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

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:

quoted

From: Chaoyi Chen <redacted>

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 <redacted>
---
 .../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.

quoted

 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