* [PATCH v3 2/2] usb: dwc3: dwc3-generic-plat: Add Renesas R-Car Gen5 DWC3 xHCI USB controller glue
2026-08-11 5:09 [PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller Marek Vasut
@ 2026-08-11 5:09 ` Marek Vasut
2026-08-17 7:00 ` [PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller Krzysztof Kozlowski
1 sibling, 0 replies; 5+ messages in thread
From: Marek Vasut @ 2026-08-11 5:09 UTC (permalink / raw)
To: linux-usb
Cc: Thanh Quan, Marek Vasut, Conor Dooley, Geert Uytterhoeven,
Greg Kroah-Hartman, Krzysztof Kozlowski, Rob Herring,
Thinh Nguyen, devicetree, linux-kernel, linux-renesas-soc
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
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller
2026-08-11 5:09 [PATCH v3 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller Marek Vasut
2026-08-11 5:09 ` [PATCH v3 2/2] usb: dwc3: dwc3-generic-plat: Add Renesas R-Car Gen5 DWC3 xHCI USB controller glue Marek Vasut
@ 2026-08-17 7:00 ` Krzysztof Kozlowski
2026-08-17 7:06 ` Geert Uytterhoeven
1 sibling, 1 reply; 5+ messages in thread
From: Krzysztof Kozlowski @ 2026-08-17 7:00 UTC (permalink / raw)
To: Marek Vasut
Cc: linux-usb, Conor Dooley, Geert Uytterhoeven, Greg Kroah-Hartman,
Krzysztof Kozlowski, Rob Herring, Thinh Nguyen, devicetree,
linux-kernel, linux-renesas-soc
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
^ permalink raw reply [flat|nested] 5+ messages in thread