Re: [PATCH v2 1/2] dt-bindings: i3c: add Realtek RTS490x I3C HUB

From: Krzysztof Kozlowski

Date: Mon May 25 2026 - 10:06:17 EST


On 25/05/2026 14:51, zain_zhou@xxxxxxxxxxxxxx wrote:
> From: Yin Zhou <zain_zhou@xxxxxxxxxxxxxx>
>
> Add DT binding schema for Realtek RTS490x series I3C HUB devices.
>
> The binding describes configuration properties for:
> - LDO enable/disable and voltage level per port group
> - Pull-up resistance per port group
> - IO driver strength per port
> - Per target-port mode (I3C/SMBus/GPIO/disabled), pull-up,
> IO mode, SMBus clock frequency and polling interval
> - Hub network always-I3C mode
> - Hardware identification via CSEL pin (id) and CP1 pins (id-cp1)
>
> Signed-off-by: Yin Zhou <zain_zhou@xxxxxxxxxxxxxx>
>
> Changes in v2:

Messed patch. DCO is always the last. And this should tell you that
changelog does not belong here - goes under ---.

Anyway, did you test the binding this time or we expect another failures?


> - Rework binding per Krzysztof Kozlowski's review:
> add realtek, vendor prefix to all custom properties; use boolean
> for enable flags; use u32 with unit suffixes (-microvolt, -ohms)
> for voltage/resistance; change to unevaluatedProperties: false;
> fix title, maintainer name, description, $nodename pattern
> - Consolidate examples; add dt-bindings/i2c/i2c.h include
> ---
> .../bindings/i3c/realtek,rts490x-i3c-hub.yaml | 263 ++++++++++++++++++
> 1 file changed, 263 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/i3c/realtek,rts490x-i3c-hub.yaml
>
> diff --git a/Documentation/devicetree/bindings/i3c/realtek,rts490x-i3c-hub.yaml b/Documentation/devicetree/bindings/i3c/realtek,rts490x-i3c-hub.yaml
> new file mode 100644
> index 000000000000..851a433abcd3
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/i3c/realtek,rts490x-i3c-hub.yaml
> @@ -0,0 +1,263 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/i3c/realtek,rts490x-i3c-hub.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Realtek RTS490x I3C HUB
> +
> +maintainers:
> + - Yin Zhou <zain_zhou@xxxxxxxxxxxxxx>
> +
> +description:
> + The Realtek RTS490x is an I3C HUB device that provides voltage level
> + translation between I3C controller and target devices, bus capacitance
> + isolation, address conflict isolation, I3C port expansion (up to 8
> + target ports), simultaneous dual-controller port support, and per-port
> + mode selection (I3C, SMBus, GPIO, or disabled).
> +
> +properties:
> + $nodename:
> + pattern: "^hub@[0-9a-f]+(,[0-9a-f]+)*$"
> +
> + compatible:
> + const: realtek,rts490x-i3c-hub
> +
> + reg:
> + maxItems: 1
> + description:
> + Encodes the static I2C address, manufacturer ID, and part/instance ID
> + as defined by the I3C specification.
> +
> + assigned-address:
> + $ref: /schemas/types.yaml#/definitions/uint32
> + minimum: 0x1
> + maximum: 0xff
> + description:
> + Dynamic I3C address to assign to this device.
> +
> + dcr:

Where is the property defined?

Read carefully writing bindings doc and DTS101 slides. I finished review
here. You still did not implement things we asked - to follow other
bindings style.

Best regards,
Krzysztof