[PATCH v4 1/3] dt-bindings: usb: amd,versal2-mmi-dwc3: Add MMI USB support on Versal Gen2 platform

[Radhey Shyam Pandey]

The Versal Gen 2 platform includes two distinct USB controllers. The
LPD controller is a USB 2.0 instance and reuses the existing
xlnx,versal-dwc3 binding. The second is the Multimedia Integrated (MMI)
USB 3.2 Gen 2x1 Dual-Role (DRD) controller, which natively supports USB
3.2 host and device operation over Type-C in a Gen 2x1 configuration
with a maximum data rate of 10 Gbps per direction.

Introduce a new compatible in <vendor>,<soc>-<subsystem>-<ip> format to
uniquely distinguish the MMI USB controller.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey at amd.com>
---
Changes for v4:
- Switch to flat mode and rephrase commit description.

Changes for v3:
- Modify commit description to explain that there are two different
  USB controllers and difference between versal2-dwc3 and
  versal2-mmi-dwc3. Suggested by Krzysztof.

Changes for v2:
- Add blank line after compatible as suggested by Krzysztof.
- Retain the mmi suffix in the compatible string, as this USB 3.2 Gen2
  IP from Synopsys is part of the dedicated Multimedia Interface. The
  Versal Gen2 platform also includes a separate USB 2.0 controller,
  and the mmi suffix uniquely distinguishes between the two USB
  controllers. MMI is an independent subsystem particularly targeted for
  deployment in Multi-Media related applications. The MMI block include
  following submodules: UDH: USB3.2 Gen 2x1 Dual Role Device, DisplayPort
  Transmit Controller, Security Module (ESM) for DisplayPort and HDMI
  Controllers, DP AUX-I2C PHY.
- For MMI USB define parent address space i.e UDH block.
- Fix inconsistent MHz spacing to use SI convention with spaces.
- Move description before $ref and items in xlnx,usb-syscon property.
- Restore original zynqmp-dwc3 example, add new versal2-mmi-dwc3 example.
- Use 'usb' node name (without unit address) for versal2 example since
  it has no reg property.
- Use 1/1 address/size configuration in versal2 example, use lowercase
  hex in syscon offsets.
---
 .../bindings/usb/amd,versal2-mmi-dwc3.yaml    | 92 +++++++++++++++++++
 1 file changed, 92 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/amd,versal2-mmi-dwc3.yaml

diff --git a/Documentation/devicetree/bindings/usb/amd,versal2-mmi-dwc3.yaml b/Documentation/devicetree/bindings/usb/amd,versal2-mmi-dwc3.yaml
new file mode 100644
index 000000000000..f71fccd95b2a
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/amd,versal2-mmi-dwc3.yaml
@@ -0,0 +1,92 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/amd,versal2-mmi-dwc3.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AMD Versal Gen 2 MMI SuperSpeedPlus DWC3 USB controller
+
+maintainers:
+  - Radhey Shyam Pandey <radhey.shyam.pandey at amd.com>
+
+description:
+  AMD Versal Gen 2 MMI (Multimedia Integrated) USB 3.2 controller.
+  The MMI subsystem integrates a DesignWare USB 3.2 host/device controller
+  with platform-specific clock, reset, and power domain management. It
+  supports USB 3.2 Gen 2x1 SuperSpeedPlus operation. SuperSpeedPlus
+  operation uses an external combo PHY shared with DisplayPort, and cable
+  orientation and role management are handled by a USB Type-C PD
+  controller.
+
+allOf:
+  - $ref: snps,dwc3-common.yaml#
+
+properties:
+  compatible:
+    const: amd,versal2-mmi-dwc3
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: SoC bus clock, has to be >= 156.25 MHz in SSP mode,
+          >= 125 MHz for SS operation and >= 60 MHz for HS operation.
+      - description: Reference clock, generates ITP when the USB2 PHY is
+          suspended.
+
+  clock-names:
+    items:
+      - const: bus_early
+      - const: ref
+
+  dma-coherent: true
+
+  interrupts:
+    maxItems: 1
+
+  phys:
+    minItems: 1
+    maxItems: 2
+
+  phy-names:
+    minItems: 1
+    maxItems: 2
+    items:
+      enum:
+        - usb2-phy
+        - usb3-phy
+
+  power-domains:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - clocks
+  - clock-names
+  - interrupts
+  - power-domains
+  - resets
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    usb at edec0000 {
+        compatible = "amd,versal2-mmi-dwc3";
+        reg = <0xedec0000 0x10000>;
+        clocks = <&usb_bus_clk>, <&usb_ref_clk>;
+        clock-names = "bus_early", "ref";
+        dma-coherent;
+        dr_mode = "host";
+        interrupts = <GIC_SPI 191 IRQ_TYPE_LEVEL_HIGH>;
+        power-domains = <&scmi_devpd 0>;
+        resets = <&scmi_reset 0>;
+    };
-- 
2.43.0