* [PATCH v1 2/2] usb: dwc3: Add Renesas R-Car Gen5 DWC3 xHCI USB controller glue
2026-07-28 1:14 [PATCH v1 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller Marek Vasut
@ 2026-07-28 1:14 ` Marek Vasut
2026-07-28 1:34 ` sashiko-bot
2026-07-28 1:31 ` [PATCH v1 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller sashiko-bot
1 sibling, 1 reply; 4+ messages in thread
From: Marek Vasut @ 2026-07-28 1:14 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. Add driver for the
glue logic around the DWC3 USB controller core.
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
---
drivers/usb/dwc3/Kconfig | 10 ++
drivers/usb/dwc3/Makefile | 1 +
drivers/usb/dwc3/dwc3-rcar-gen5.c | 150 ++++++++++++++++++++++++++++++
3 files changed, 161 insertions(+)
create mode 100644 drivers/usb/dwc3/dwc3-rcar-gen5.c
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 18169727a413e..7d8ee192b1241 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -234,4 +234,14 @@ config USB_DWC3_GOOGLE
To compile this driver as a module, choose M here: the
module will be called dwc3-google.ko.
+config USB_DWC3_RCAR_GEN5
+ tristate "Renesas R-Car Gen5 DWC3 Platform Driver"
+ depends on ARCH_RENESAS || COMPILE_TEST
+ default USB_DWC3
+ help
+ Support the DesignWare Core USB3 IP found on Renesas R-Car Gen5
+ SoC. This driver provides the glue layer for the USB controller
+ on Renesas R-Car Gen5 platform.
+ Say 'Y' or 'M' if you have such device.
+
endif
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index f37971197203e..99bbd147f0b5f 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -61,3 +61,4 @@ obj-$(CONFIG_USB_DWC3_OCTEON) += dwc3-octeon.o
obj-$(CONFIG_USB_DWC3_RTK) += dwc3-rtk.o
obj-$(CONFIG_USB_DWC3_GENERIC_PLAT) += dwc3-generic-plat.o
obj-$(CONFIG_USB_DWC3_GOOGLE) += dwc3-google.o
+obj-$(CONFIG_USB_DWC3_RCAR_GEN5) += dwc3-rcar-gen5.o
diff --git a/drivers/usb/dwc3/dwc3-rcar-gen5.c b/drivers/usb/dwc3/dwc3-rcar-gen5.c
new file mode 100644
index 0000000000000..344d0851559f5
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-rcar-gen5.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Renesas USB device driver with DWC3 integration
+ *
+ * Copyright (C) 2025-2026 Renesas Electronics Corporation
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+
+struct dwc3_rcar_gen5_priv {
+ void __iomem *base;
+ struct clk *clk;
+ bool use_usb3_flow;
+};
+
+static int dwc3_rcar_gen5_init(struct dwc3_rcar_gen5_priv *priv)
+{
+ /*
+ * 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, priv->base + 0x26);
+
+ /* USB3 does not need additional register programming. */
+ if (priv->use_usb3_flow)
+ return 0;
+
+ writew(0x11, priv->base + 0x81c);
+ writew(0x0, priv->base + 0x81a);
+ writew(0x1, priv->base + 0x802);
+
+ usleep_range(10000, 20000);
+
+ writew(0x0, priv->base + 0x802);
+ writew(0x1, priv->base + 0x2a);
+ writew(0x1, priv->base + 0x81a);
+
+ usleep_range(10000, 20000);
+
+ return 0;
+}
+
+static int dwc3_rcar_gen5_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *subnode;
+ struct reset_control *reset;
+ const char *maximum_speed;
+ struct dwc3_rcar_gen5_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, priv);
+
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return dev_err_probe(dev, PTR_ERR(priv->base), "Failed to map registers\n");
+
+ reset = devm_reset_control_get(dev, NULL);
+ if (IS_ERR(reset))
+ return dev_err_probe(dev, PTR_ERR(reset), "Failed to get reset control\n");
+
+ priv->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(priv->clk))
+ return dev_err_probe(dev, PTR_ERR(priv->clk), "Failed to get clock control\n");
+
+ subnode = of_get_compatible_child(dev->of_node, "synopsys,dwc3");
+ if (!subnode)
+ return dev_err_probe(dev, -ENODEV, "Failed to find DWC3 subnode node\n");
+
+ ret = of_property_read_string(subnode, "maximum-speed", &maximum_speed);
+ of_node_put(subnode);
+ if (ret)
+ return dev_err_probe(dev, -ENODEV, "Failed to determine maximum speed\n");
+
+ priv->use_usb3_flow = !strcmp(maximum_speed, "super-speed-plus") ||
+ !strcmp(maximum_speed, "super-speed");
+
+ ret = devm_pm_runtime_enable(dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable runtime PM\n");
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to resume runtime PM\n");
+
+ return devm_of_platform_populate(dev);
+}
+
+static int __maybe_unused dwc3_rcar_gen5_suspend(struct device *dev)
+{
+ struct dwc3_rcar_gen5_priv *priv = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(priv->clk);
+
+ return 0;
+}
+
+static int __maybe_unused dwc3_rcar_gen5_resume(struct device *dev)
+{
+ struct dwc3_rcar_gen5_priv *priv = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_prepare_enable(priv->clk);
+ if (ret) {
+ dev_err(dev, "Failed to enable clock on resume: %d\n", ret);
+ return ret;
+ }
+
+ usleep_range(10000, 20000);
+
+ return dwc3_rcar_gen5_init(priv);
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(dwc3_rcar_gen5_pm_ops,
+ dwc3_rcar_gen5_suspend,
+ dwc3_rcar_gen5_resume, NULL);
+
+static const struct of_device_id dwc3_rcar_gen5_of_match[] = {
+ { .compatible = "renesas,rcar-gen5-usb" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, dwc3_rcar_gen5_of_match);
+
+static struct platform_driver dwc3_rcar_gen5_driver = {
+ .probe = dwc3_rcar_gen5_probe,
+ .driver = {
+ .name = "renesas-rcar-gen5-usb",
+ .of_match_table = dwc3_rcar_gen5_of_match,
+ .pm = &dwc3_rcar_gen5_pm_ops,
+ },
+};
+
+module_platform_driver(dwc3_rcar_gen5_driver);
+
+MODULE_AUTHOR("Thanh Quan");
+MODULE_DESCRIPTION("Renesas R-Car X5H USB Glue Layer Driver");
+MODULE_LICENSE("GPL");
--
2.53.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v1 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller
2026-07-28 1:14 [PATCH v1 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller Marek Vasut
2026-07-28 1:14 ` [PATCH v1 2/2] usb: dwc3: Add Renesas R-Car Gen5 DWC3 xHCI USB controller glue Marek Vasut
@ 2026-07-28 1:31 ` sashiko-bot
1 sibling, 0 replies; 4+ messages in thread
From: sashiko-bot @ 2026-07-28 1:31 UTC (permalink / raw)
To: Marek Vasut; +Cc: devicetree, robh, wsa+renesas, conor+dt
Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] The device tree binding example uses a deprecated compatible string 'synopsys,dwc3' for the child DWC3 node.
--
--- Patch [1]: [PATCH v1 1/2] dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller ---
commit 716289e3efcde452eab06f93d71e6ed140cbc0c3
Author: Marek Vasut <marek.vasut+renesas@mailbox.org>
dt-bindings: usb: dwc3: Document Renesas R-Car Gen5 DWC3 xHCI USB controller
This commit adds documentation for the Renesas R-Car Gen5 DWC3 xHCI USB
controller and its glue logic wrapper. It defines a new YAML binding schema
that references the core snps,dwc3.yaml schema.
> diff --git a/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-usb.yaml b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-usb.yaml
> new file mode 100644
> index 0000000000000..a334648e2dfc4
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/usb/renesas,rcar-gen5-usb.yaml
[ ... ]
> +examples:
> + - |
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> + bus {
> + #address-cells = <2>;
> + #size-cells = <2>;
> +
> + usb@c9c54000 {
> + compatible = "renesas,r8a78000-usb", "renesas,rcar-gen5-usb";
[ ... ]
> + ranges = <0x0 0xc8800000 0x0 0xc8800000 0x0 0x100000>;
> +
> + usb@c8800000 {
> + compatible = "synopsys,dwc3";
[Severity: Low]
This isn't a bug, but the example uses the deprecated compatible string
"synopsys,dwc3" for the child DWC3 node. The base schema snps,dwc3.yaml
explicitly marks this as deprecated in favor of "snps,dwc3".
Should this be updated to avoid triggering warnings during schema validation
and to prevent users from copying outdated patterns into new device trees?
> + reg = <0x0 0xc8800000 0x0 0x100000>;
> + interrupts = <GIC_SPI 795 IRQ_TYPE_LEVEL_HIGH>;
> + maximum-speed = "super-speed-plus";
> + phys = <&mp_phy 2>;
> + phy-names = "usb3-phy";
> + };
> + };
> + };
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260728011656.465040-1-marek.vasut+renesas@mailbox.org?part=1
^ permalink raw reply [flat|nested] 4+ messages in thread