[PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller

[PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller

[Marek Vasut]

The Renesas R-Car Gen5 SoC contains multiple instances of DWC3 USB
controller with glue logic wrapper around them. Document the glue
logic and DWC3 controller.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
---
V2: Rework to use flat bindings for generic plat driver
V3: - Support one or two PHYs to correctly describe the hardware
    - Make maximum-speed optional
---
 .../bindings/usb/renesas,rcar-gen5-dwc3.yaml  | 81 +++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml

diff --git a/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml
new file mode 100644
index 0000000000000..37944a7d5be04
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml
@@ -0,0 +1,81 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/renesas,rcar-gen5-dwc3.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas R-Car Gen5 DWC3 xHCI USB controller
+
+maintainers:
+  - Marek Vasut <marek.vasut+renesas@mailbox.org>
+
+properties:
+  compatible:
+    items:
+      - const: renesas,r8a78000-dwc3
+      - const: renesas,rcar-gen5-dwc3
+
+  reg:
+    maxItems: 2
+
+  reg-names:
+    items:
+      - const: dwc3
+      - const: glue
+
+  clocks:
+    maxItems: 1
+
+  dr_mode:
+    enum: [ host, otg, peripheral ]
+
+  interrupts:
+    maxItems: 1
+
+  maximum-speed:
+    enum: [ super-speed-plus, super-speed, high-speed ]
+
+  phys:
+    minItems: 1
+    maxItems: 2
+
+  phy-names:
+    minItems: 1
+    items:
+      - const: usb2-phy
+      - const: usb3-phy
+
+  power-domains:
+    maxItems: 1
+
+  resets:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - reg-names
+  - clocks
+  - interrupts
+  - phys
+  - phy-names
+  - power-domains
+  - resets
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    usb@c8800000 {
+        compatible = "renesas,r8a78000-dwc3", "renesas,rcar-gen5-dwc3";
+        reg = <0xc8800000 0x100000>, <0xc9c54000 0x2000>;
+        reg-names = "dwc3", "glue";
+        clocks = <&scmi_clk 336>;
+        interrupts = <GIC_SPI 795 IRQ_TYPE_LEVEL_HIGH>;
+        phys = <&usb30_phy>, <&mp_phy 2>;
+        phy-names = "usb2-phy", "usb3-phy";
+        power-domains = <&scmi_devpd 16>;
+        resets = <&scmi_reset 336>;
+    };
-- 
2.53.0

[PATCH v3 2/2] usb: dwc3: dwc3-generic-plat: Add Renesas R-Car Gen5 DWC3 xHCI USB controller glue

[Marek Vasut]

From: Thanh Quan <thanh.quan.xn@renesas.com>

The Renesas R-Car Gen5 SoC contains multiple instances of DWC3 USB
controller with glue logic wrapper around them. Extend the generic
DWC3 platform driver with Renesas R-Car Gen5 glue logic specifics.

Signed-off-by: Thanh Quan <thanh.quan.xn@renesas.com>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Conor Dooley <conor+dt@kernel.org>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
---
V2: Extend dwc3-generic-plat driver instead
V3: Handle maximum-speed as optional property, test for USB 3 PHY
    non-presence to determine whether the controller is USB 2 only,
    consider optional maximum-speed DT property, but if it is missing
    then default to maximum controller capabilities based on the
    presence of PHY phandles.
---
 drivers/usb/dwc3/dwc3-generic-plat.c | 60 ++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)

diff --git a/drivers/usb/dwc3/dwc3-generic-plat.c b/drivers/usb/dwc3/dwc3-generic-plat.c
index ca69ac0eb07ce..dec89b068291a 100644
--- a/drivers/usb/dwc3/dwc3-generic-plat.c
+++ b/drivers/usb/dwc3/dwc3-generic-plat.c
@@ -71,6 +71,60 @@ static int dwc3_eic7700_init(struct dwc3_generic *dwc3g)
 	return 0;
 }
 
+static int dwc3_renesas_rcar_gen5_init(struct dwc3_generic *dwc3g)
+{
+	struct device *dev = dwc3g->dev;
+	struct platform_device *pdev = to_platform_device(dev);
+	enum usb_device_speed speed = usb_get_maximum_speed(dev);
+	bool usb2only = false;
+	void __iomem *glue;
+
+	/* Wireless USB is not supported */
+	if (speed == USB_SPEED_WIRELESS)
+		return dev_err_probe(dev, -EINVAL, "Wireless USB not supported\n");
+
+	/* No USB 3 PHY in DT means this is surely USB 2 controller */
+	if (device_property_match_string(dev, "phy-names", "usb3-phy") < 0)
+		usb2only = true;
+
+	/*
+	 * Controller can be limited to USB 2 via optional maximum-speed DT
+	 * property. If the DT property is not present, default to maximum
+	 * controller capabilities.
+	 */
+	if (speed >= USB_SPEED_LOW && speed <= USB_SPEED_HIGH)
+		usb2only = true;
+
+	glue = devm_platform_ioremap_resource_byname(pdev, "glue");
+	if (IS_ERR(glue))
+		return PTR_ERR(glue);
+
+	/*
+	 * The datasheet describes initialization procedure without full
+	 * information about the registers. Therefore, the source code is
+	 * based on the bare metal code shared by the board team.
+	 */
+	writew(0x211, glue + 0x26);
+
+	/* USB2 does need additional register programming. */
+	if (!usb2only)
+		return 0;
+
+	writew(0x11, glue + 0x81c);
+	writew(0x0, glue + 0x81a);
+	writew(0x1, glue + 0x802);
+
+	usleep_range(10000, 20000);
+
+	writew(0x0, glue + 0x802);
+	writew(0x1, glue + 0x2a);
+	writew(0x1, glue + 0x81a);
+
+	usleep_range(10000, 20000);
+
+	return 0;
+}
+
 static int dwc3_spacemit_k1_init(struct dwc3_generic *dwc3g)
 {
 	struct device *dev = dwc3g->dev;
@@ -231,11 +285,17 @@ static const struct dwc3_generic_config eic7700_dwc3 =  {
 	.properties = DWC3_DEFAULT_PROPERTIES,
 };
 
+static const struct dwc3_generic_config renesas_rcar_gen5_dwc3 = {
+	.init = dwc3_renesas_rcar_gen5_init,
+	.properties = DWC3_DEFAULT_PROPERTIES,
+};
+
 static const struct of_device_id dwc3_generic_of_match[] = {
 	{ .compatible = "spacemit,k1-dwc3", &spacemit_k1_dwc3},
 	{ .compatible = "spacemit,k3-dwc3", },
 	{ .compatible = "fsl,ls1028a-dwc3", &fsl_ls1028_dwc3},
 	{ .compatible = "eswin,eic7700-dwc3", &eic7700_dwc3},
+	{ .compatible = "renesas,rcar-gen5-dwc3", &renesas_rcar_gen5_dwc3},
 	{ .compatible = "starfive,jhb100-dwc3", },
 	{ /* sentinel */ }
 };
-- 
2.53.0

Re: [PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller

[Krzysztof Kozlowski]

On Tue, Aug 11, 2026 at 07:09:33AM +0200, Marek Vasut wrote:
> The Renesas R-Car Gen5 SoC contains multiple instances of DWC3 USB
> controller with glue logic wrapper around them. Document the glue
> logic and DWC3 controller.
> 
> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Cc: Conor Dooley <conor+dt@kernel.org>
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org>
> Cc: Rob Herring <robh@kernel.org>
> Cc: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> Cc: devicetree@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> Cc: linux-usb@vger.kernel.org
> ---
> V2: Rework to use flat bindings for generic plat driver
> V3: - Support one or two PHYs to correctly describe the hardware
>     - Make maximum-speed optional
> ---
>  .../bindings/usb/renesas,rcar-gen5-dwc3.yaml  | 81 +++++++++++++++++++
>  1 file changed, 81 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml
> 
> diff --git a/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml
> new file mode 100644
> index 0000000000000..37944a7d5be04
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml
> @@ -0,0 +1,81 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/usb/renesas,rcar-gen5-dwc3.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Renesas R-Car Gen5 DWC3 xHCI USB controller
> +
> +maintainers:
> +  - Marek Vasut <marek.vasut+renesas@mailbox.org>
> +
> +properties:
> +  compatible:
> +    items:
> +      - const: renesas,r8a78000-dwc3
> +      - const: renesas,rcar-gen5-dwc3
> +
> +  reg:
> +    maxItems: 2
> +
> +  reg-names:
> +    items:
> +      - const: dwc3
> +      - const: glue
> +
> +  clocks:
> +    maxItems: 1
> +
> +  dr_mode:

We don't accept properties with underscores, unless this is coming from
existing schema but I do not see snps,dwc referenced in the binding.

> +    enum: [ host, otg, peripheral ]
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  maximum-speed:

Again, where is the property defined?

> +    enum: [ super-speed-plus, super-speed, high-speed ]
> +
> +  phys:
> +    minItems: 1
> +    maxItems: 2

Why is this flexible?

> +
> +  phy-names:
> +    minItems: 1
> +    items:
> +      - const: usb2-phy

phy is redundant. Are you implementing completely new bindings which
have nothing in common with all others?

Best regards,
Krzysztof

Re: [PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller

[Geert Uytterhoeven]

On Mon, 17 Aug 2026 at 09:01, Krzysztof Kozlowski <krzk@kernel.org> wrote:
> On Tue, Aug 11, 2026 at 07:09:33AM +0200, Marek Vasut wrote:
> > The Renesas R-Car Gen5 SoC contains multiple instances of DWC3 USB
> > controller with glue logic wrapper around them. Document the glue
> > logic and DWC3 controller.
> >
> > Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>

> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml

> > +  dr_mode:
>
> We don't accept properties with underscores, unless this is coming from
> existing schema but I do not see snps,dwc referenced in the binding.
>
> > +    enum: [ host, otg, peripheral ]

Probably this should just reference usb/usb-drd.yaml instead of
defining it itselves.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller

[Krzysztof Kozlowski]

On 17/08/2026 09:06, Geert Uytterhoeven wrote:
> On Mon, 17 Aug 2026 at 09:01, Krzysztof Kozlowski <krzk@kernel.org> wrote:
>> On Tue, Aug 11, 2026 at 07:09:33AM +0200, Marek Vasut wrote:
>>> The Renesas R-Car Gen5 SoC contains multiple instances of DWC3 USB
>>> controller with glue logic wrapper around them. Document the glue
>>> logic and DWC3 controller.
>>>
>>> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> 
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-dwc3.yaml
> 
>>> +  dr_mode:
>>
>> We don't accept properties with underscores, unless this is coming from
>> existing schema but I do not see snps,dwc referenced in the binding.
>>
>>> +    enum: [ host, otg, peripheral ]
> 
> Probably this should just reference usb/usb-drd.yaml instead of
> defining it itselves.
If this is DWC, why isn't it referencing snps,dwc-common?


Best regards,
Krzysztof