Add support for the USB 3.0 Dual-Role Device (DRD) controller embedded
in
the SpacemiT K1 SoC. The controller is based on the Synopsys DesignWare
Core USB 3 (DWC3) IP, supporting both Host and Device modes for USB 3.0
and USB 2.0 standards.

Signed-off-by: Ze Huang <huangze@whut.edu.cn>
---
 .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 95 ++++++++++++++++++++++
 1 file changed, 95 insertions(+)

diff --git a/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..5aece388900fa5bda9acb19add658310064bef8f
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.yaml
@@ -0,0 +1,95 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/spacemit,k1-dwc3.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SpacemiT K1 SuperSpeed DWC3 USB SoC Controller
+
+maintainers:
+  - Ze Huang <huangze@whut.edu.cn>
+
+description: |
+  The SpacemiT K1 embeds a DWC3 USB IP Core which supports both Host and Device
+  functions for USB 3.0 and USB 2.0 standards.
+
+  Key features:
+  - USB3.0 SuperSpeed and USB2.0 High/Full/Low-Speed support
+  - Supports low-power modes (USB2.0 suspend, USB3.0 U1/U2/U3)
+  - Internal DMA controller and flexible endpoint FIFO sizing
+
+  Communication Interface:
+  - Use of PIPE3 (125MHz) interface for USB3.0 PHY
+  - Use of UTMI+ (30/60MHz) interface for USB2.0 PHY
+
+  The common content of the node is defined in snps,dwc3.yaml.
+
+select:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - spacemit,k1-dwc3
+  required:
+    - compatible
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - spacemit,k1-dwc3
+      - const: snps,dwc3
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  clock-names:
+    const: bus_early
+
+  resets:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  interconnects:
+    maxItems: 1
+    description:
+      On SpacemiT K1, USB performs DMA through bus other than parent DT node.
+      The 'interconnects' property explicitly describes this path, ensuring
+      correct address translation.
+
+  interconnect-names:
+    const: dma-mem
+
+  vbus-supply:
+    description: A phandle to the regulator supplying the VBUS voltage.
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - resets
+  - interrupts
+  - interconnects
+  - interconnect-names
+
+additionalProperties: false
+
+examples:
+  - |
+    usb@c0a00000 {
+        compatible = "spacemit,k1-dwc3", "snps,dwc3";
+        reg = <0xc0a00000 0x10000>;
+        clocks = <&syscon_apmu 16>;
+        clock-names = "bus_early";
+        resets = <&syscon_apmu 8>;
+        interrupt-parent = <&plic>;
+        interrupts = <125>;
+        interconnects = <&dram_range0>;
+        interconnect-names = "dma-mem";
+    };

-- 
2.49.0

On Mon, 28 Apr 2025 15:38:11 +0800, Ze Huang wrote:
> Add support for the USB 3.0 Dual-Role Device (DRD) controller embedded
> in
> the SpacemiT K1 SoC. The controller is based on the Synopsys DesignWare
> Core USB 3 (DWC3) IP, supporting both Host and Device modes for USB 3.0
> and USB 2.0 standards.
> 
> Signed-off-by: Ze Huang <huangze@whut.edu.cn>
> ---
>  .../devicetree/bindings/usb/spacemit,k1-dwc3.yaml  | 95 ++++++++++++++++++++++
>  1 file changed, 95 insertions(+)
> 

My bot found errors running 'make dt_binding_check' on your patch:

yamllint warnings/errors:

dtschema/dtc warnings/errors:
/builds/robherring/dt-review-ci/linux/Documentation/devicetree/bindings/usb/spacemit,k1-dwc3.example.dtb: usb@c0a00000 (spacemit,k1-dwc3): Unevaluated properties are not allowed ('interconnect-names', 'interconnects' were unexpected)
	from schema $id: http://devicetree.org/schemas/usb/snps,dwc3.yaml#

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/project/devicetree-bindings/patch/20250428-b4-k1-dwc3-v2-v1-1-7cb061abd619@whut.edu.cn

The base for the series is generally the latest rc1. A different dependency
should be noted in *this* patch.

If you already ran 'make dt_binding_check' and didn't see the above
error(s), then make sure 'yamllint' is installed and dt-schema is up to
date:

pip3 install dtschema --upgrade

Please check and re-submit after running the above command yourself. Note
that DT_SCHEMA_FILES can be set to your schema file to speed up checking
your schema. However, it must be unset to test all examples with your schema.