Message-ID: <aYYQ3jJ8GVIz4FS0@lizhi-Precision-Tower-5810>
Date: Fri, 6 Feb 2026 11:03:42 -0500
From: Frank Li <Frank.li@....com>
To: Xu Yang <xu.yang_2@....com>
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Rob Herring <robh@...nel.org>,
	Krzysztof Kozlowski <krzk+dt@...nel.org>,
	Conor Dooley <conor+dt@...nel.org>, Shawn Guo <shawnguo@...nel.org>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Pengutronix Kernel Team <kernel@...gutronix.de>,
	Fabio Estevam <festevam@...il.com>, Li Jun <jun.li@....com>,
	Thinh Nguyen <Thinh.Nguyen@...opsys.com>, linux-usb@...r.kernel.org,
	devicetree@...r.kernel.org, imx@...ts.linux.dev,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 3/3] usb: dwc3: introduce flatten model driver of i.MX
 Soc

On Fri, Feb 06, 2026 at 06:18:51PM +0800, Xu Yang wrote:
> The i.MX USB glue and DWC3 core are closely coupled. Describe the i.MX
> USB block in a single block will bring more benefits than a parent-
> child relation. To support the flatten model devicetree, DWC3 USB core
> driver already support to directly register and initialize the core in
> glue layer using one device. And many notification can be received in
> glue layer timely and proper actions can be executed accordingly.
>
> To align with mainstream, introduce a new driver to support flatten dwc3
> devicetree model for i.MX Soc. Besides this driver disabling wakeup irq
> when system is active, no other function change in this version compared
> to dwc3-imx8mp.c
>
> Signed-off-by: Xu Yang <xu.yang_2@....com>
>
> ---
> Changes in v3:
>  - update compatible as nxp,imx8mp-dwc3
> Changes in v2:
>  - improve commit message
>  - fix code style
>  - add IRQF_NO_AUTOEN
>  - remove pm_runtime_* in dwc3_imx_remove(), dwc3_core_remove()
>    will do that
> ---
>  drivers/usb/dwc3/Kconfig    |  12 ++
>  drivers/usb/dwc3/Makefile   |   1 +
>  drivers/usb/dwc3/dwc3-imx.c | 429 ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 442 insertions(+)
>
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 240b15bc52cb..18169727a413 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -150,6 +150,18 @@ config USB_DWC3_IMX8MP
>  	  functionality.
>  	  Say 'Y' or 'M' if you have one such device.
>
> +config USB_DWC3_IMX
> +	tristate "NXP iMX Platform"
> +	depends on OF && COMMON_CLK
> +	depends on (ARCH_MXC && ARM64) || COMPILE_TEST
> +	default USB_DWC3
> +	help
> +	  NXP iMX SoC use DesignWare Core IP for USB2/3
> +	  functionality.
> +	  This driver also handles the wakeup feature outside
> +	  of DesignWare Core.
> +	  Say 'Y' or 'M' if you have one such device.
> +
>  config USB_DWC3_XILINX
>  	tristate "Xilinx Platforms"
>  	depends on (ARCH_ZYNQMP || COMPILE_TEST) && OF
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index 073bef5309b5..f37971197203 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -55,6 +55,7 @@ obj-$(CONFIG_USB_DWC3_ST)		+= dwc3-st.o
>  obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom.o
>  obj-$(CONFIG_USB_DWC3_QCOM)		+= dwc3-qcom-legacy.o
>  obj-$(CONFIG_USB_DWC3_IMX8MP)		+= dwc3-imx8mp.o
> +obj-$(CONFIG_USB_DWC3_IMX)		+= dwc3-imx.o
>  obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
>  obj-$(CONFIG_USB_DWC3_OCTEON)		+= dwc3-octeon.o
>  obj-$(CONFIG_USB_DWC3_RTK)		+= dwc3-rtk.o
> diff --git a/drivers/usb/dwc3/dwc3-imx.c b/drivers/usb/dwc3/dwc3-imx.c
> new file mode 100644
> index 000000000000..3b154d075bcf
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-imx.c
> @@ -0,0 +1,429 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * dwc3-imx.c - NXP i.MX Soc USB3 Specific Glue layer
> + *
> + * Copyright 2026 NXP
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of_platform.h>
> +#include <linux/platform_device.h>
> +#include <linux/pm_runtime.h>
> +
> +#include "core.h"
> +#include "glue.h"
> +
> +/* USB wakeup registers */
> +#define USB_WAKEUP_CTRL			0x00
> +
> +/* Global wakeup interrupt enable, also used to clear interrupt */
> +#define USB_WAKEUP_EN			BIT(31)
> +/* Wakeup from connect or disconnect, only for superspeed */
> +#define USB_WAKEUP_SS_CONN		BIT(5)
> +/* 0 select vbus_valid, 1 select sessvld */
> +#define USB_WAKEUP_VBUS_SRC_SESS_VAL	BIT(4)
> +/* Enable signal for wake up from u3 state */
> +#define USB_WAKEUP_U3_EN		BIT(3)
> +/* Enable signal for wake up from id change */
> +#define USB_WAKEUP_ID_EN		BIT(2)
> +/* Enable signal for wake up from vbus change */
> +#define	USB_WAKEUP_VBUS_EN		BIT(1)
> +/* Enable signal for wake up from dp/dm change */
> +#define USB_WAKEUP_DPDM_EN		BIT(0)
> +
> +#define USB_WAKEUP_EN_MASK		GENMASK(5, 0)
> +
> +/* USB glue registers */
> +#define USB_CTRL0		0x00
> +#define USB_CTRL1		0x04
> +
> +#define USB_CTRL0_PORTPWR_EN	BIT(12) /* 1 - PPC enabled (default) */
> +#define USB_CTRL0_USB3_FIXED	BIT(22) /* 1 - USB3 permanent attached */
> +#define USB_CTRL0_USB2_FIXED	BIT(23) /* 1 - USB2 permanent attached */
> +
> +#define USB_CTRL1_OC_POLARITY	BIT(16) /* 0 - HIGH / 1 - LOW */
> +#define USB_CTRL1_PWR_POLARITY	BIT(17) /* 0 - HIGH / 1 - LOW */
> +
> +struct dwc3_imx {
> +	struct dwc3	dwc;
> +	struct device	*dev;
> +	void __iomem	*blkctl_base;
> +	void __iomem	*glue_base;
> +	struct clk	*hsio_clk;
> +	struct clk	*suspend_clk;
> +	int		irq;
> +	bool		pm_suspended;
> +	bool		wakeup_pending;
> +};
> +
> +#define to_dwc3_imx(d) container_of((d), struct dwc3_imx, dwc)
> +
> +static void dwc3_imx_configure_glue(struct dwc3_imx *dwc_imx)
> +{
> +	struct device	*dev = dwc_imx->dev;
> +	u32		value;
> +
> +	if (!dwc_imx->glue_base)
> +		return;
> +
> +	value = readl(dwc_imx->glue_base + USB_CTRL0);
> +
> +	if (device_property_read_bool(dev, "fsl,permanently-attached"))

can you parse it at probe and save into dwc3_imx to avoid parse dts every
resume()?

Frank
> +		value |= USB_CTRL0_USB2_FIXED | USB_CTRL0_USB3_FIXED;
> +	else
> +		value &= ~(USB_CTRL0_USB2_FIXED | USB_CTRL0_USB3_FIXED);
> +
> +	if (device_property_read_bool(dev, "fsl,disable-port-power-control"))
> +		value &= ~USB_CTRL0_PORTPWR_EN;
> +	else
> +		value |= USB_CTRL0_PORTPWR_EN;
> +
> +	writel(value, dwc_imx->glue_base + USB_CTRL0);
> +
> +	value = readl(dwc_imx->glue_base + USB_CTRL1);
> +	if (device_property_read_bool(dev, "fsl,over-current-active-low"))
> +		value |= USB_CTRL1_OC_POLARITY;
> +	else
> +		value &= ~USB_CTRL1_OC_POLARITY;
> +
> +	if (device_property_read_bool(dev, "fsl,power-active-low"))
> +		value |= USB_CTRL1_PWR_POLARITY;
> +	else
> +		value &= ~USB_CTRL1_PWR_POLARITY;
> +
> +	writel(value, dwc_imx->glue_base + USB_CTRL1);
> +}
> +
> +static void dwc3_imx_wakeup_enable(struct dwc3_imx *dwc_imx, pm_message_t msg)
> +{
> +	struct dwc3	*dwc = &dwc_imx->dwc;
> +	u32		val;
> +
> +	val = readl(dwc_imx->blkctl_base + USB_WAKEUP_CTRL);
> +
> +	if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST && dwc->xhci) {
> +		val |= USB_WAKEUP_EN | USB_WAKEUP_DPDM_EN;
> +		if (PMSG_IS_AUTO(msg))
> +			val |= USB_WAKEUP_SS_CONN | USB_WAKEUP_U3_EN;
> +	} else {
> +		val |= USB_WAKEUP_EN | USB_WAKEUP_VBUS_EN |
> +		       USB_WAKEUP_VBUS_SRC_SESS_VAL;
> +	}
> +
> +	writel(val, dwc_imx->blkctl_base + USB_WAKEUP_CTRL);
> +}
> +
> +static void dwc3_imx_wakeup_disable(struct dwc3_imx *dwc_imx)
> +{
> +	u32	val;
> +
> +	val = readl(dwc_imx->blkctl_base + USB_WAKEUP_CTRL);
> +	val &= ~(USB_WAKEUP_EN | USB_WAKEUP_EN_MASK);
> +	writel(val, dwc_imx->blkctl_base + USB_WAKEUP_CTRL);
> +}
> +
> +static irqreturn_t dwc3_imx_interrupt(int irq, void *data)
> +{
> +	struct dwc3_imx	*dwc_imx = data;
> +	struct dwc3	*dwc = &dwc_imx->dwc;
> +
> +	if (!dwc_imx->pm_suspended)
> +		return IRQ_HANDLED;
> +
> +	disable_irq_nosync(dwc_imx->irq);
> +	dwc_imx->wakeup_pending = true;
> +
> +	if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_HOST && dwc->xhci)
> +		pm_runtime_resume(&dwc->xhci->dev);
> +	else if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE)
> +		pm_runtime_get(dwc->dev);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static void dwc3_imx_pre_set_role(struct dwc3 *dwc, enum usb_role role)
> +{
> +	if (role == USB_ROLE_HOST)
> +		/*
> +		 * For xhci host, we need disable dwc core auto
> +		 * suspend, because during this auto suspend delay(5s),
> +		 * xhci host RUN_STOP is cleared and wakeup is not
> +		 * enabled, if device is inserted, xhci host can't
> +		 * response the connection.
> +		 */
> +		pm_runtime_dont_use_autosuspend(dwc->dev);
> +	else
> +		pm_runtime_use_autosuspend(dwc->dev);
> +}
> +
> +static struct dwc3_glue_ops dwc3_imx_glue_ops = {
> +	.pre_set_role = dwc3_imx_pre_set_role,
> +};
> +
> +static const struct property_entry dwc3_imx_properties[] = {
> +	PROPERTY_ENTRY_BOOL("xhci-missing-cas-quirk"),
> +	PROPERTY_ENTRY_BOOL("xhci-skip-phy-init-quirk"),
> +	{},
> +};
> +
> +static const struct software_node dwc3_imx_swnode = {
> +	.properties = dwc3_imx_properties,
> +};
> +
> +static int dwc3_imx_probe(struct platform_device *pdev)
> +{
> +	struct device		*dev = &pdev->dev;
> +	struct dwc3_imx		*dwc_imx;
> +	struct dwc3		*dwc;
> +	struct resource		*res;
> +	const char		*irq_name;
> +	struct dwc3_probe_data	probe_data = {};
> +	int			ret, irq;
> +
> +	dwc_imx = devm_kzalloc(dev, sizeof(*dwc_imx), GFP_KERNEL);
> +	if (!dwc_imx)
> +		return -ENOMEM;
> +
> +	platform_set_drvdata(pdev, dwc_imx);
> +	dwc_imx->dev = dev;
> +
> +	dwc_imx->blkctl_base = devm_platform_ioremap_resource_byname(pdev, "blkctl");
> +	if (IS_ERR(dwc_imx->blkctl_base))
> +		return PTR_ERR(dwc_imx->blkctl_base);
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "glue");
> +	if (!res) {
> +		dev_warn(dev, "Base address for glue layer missing\n");
> +	} else {
> +		dwc_imx->glue_base = devm_ioremap_resource(dev, res);
> +		if (IS_ERR(dwc_imx->glue_base))
> +			return PTR_ERR(dwc_imx->glue_base);
> +	}
> +
> +	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "core");
> +	if (!res)
> +		return dev_err_probe(dev, -ENODEV, "missing core memory resource\n");
> +
> +	dwc_imx->hsio_clk = devm_clk_get_enabled(dev, "hsio");
> +	if (IS_ERR(dwc_imx->hsio_clk))
> +		return dev_err_probe(dev, PTR_ERR(dwc_imx->hsio_clk),
> +				     "Failed to get hsio clk\n");
> +
> +	dwc_imx->suspend_clk = devm_clk_get_enabled(dev, "suspend");
> +	if (IS_ERR(dwc_imx->suspend_clk))
> +		return dev_err_probe(dev, PTR_ERR(dwc_imx->suspend_clk),
> +				     "Failed to get suspend clk\n");
> +
> +	irq = platform_get_irq_byname(pdev, "wakeup");
> +	if (irq < 0)
> +		return irq;
> +	dwc_imx->irq = irq;
> +
> +	irq_name = devm_kasprintf(dev, GFP_KERNEL, "%s:wakeup", dev_name(dev));
> +	if (!irq_name)
> +		return dev_err_probe(dev, -ENOMEM, "failed to create irq_name\n");
> +
> +	ret = devm_request_threaded_irq(dev, irq, NULL, dwc3_imx_interrupt,
> +					IRQF_ONESHOT | IRQF_NO_AUTOEN,
> +					irq_name, dwc_imx);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to request IRQ #%d\n", irq);
> +
> +	ret = device_add_software_node(dev, &dwc3_imx_swnode);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "failed to add software node\n");
> +
> +	dwc = &dwc_imx->dwc;
> +	dwc->dev = dev;
> +	dwc->glue_ops = &dwc3_imx_glue_ops;
> +
> +	probe_data.res = res;
> +	probe_data.dwc = dwc;
> +	probe_data.properties = DWC3_DEFAULT_PROPERTIES;
> +	probe_data.properties.core_may_lose_power = true;
> +
> +	ret = dwc3_core_probe(&probe_data);
> +	if (ret) {
> +		device_remove_software_node(dev);
> +		return ret;
> +	}
> +
> +	device_set_wakeup_capable(dev, true);
> +	return 0;
> +}
> +
> +static void dwc3_imx_remove(struct platform_device *pdev)
> +{
> +	struct device	*dev = &pdev->dev;
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +
> +	dwc3_core_remove(dwc);
> +	device_remove_software_node(dev);
> +}
> +
> +static void dwc3_imx_suspend(struct dwc3_imx *dwc_imx, pm_message_t msg)
> +{
> +	if (PMSG_IS_AUTO(msg) || device_may_wakeup(dwc_imx->dev))
> +		dwc3_imx_wakeup_enable(dwc_imx, msg);
> +
> +	enable_irq(dwc_imx->irq);
> +	dwc_imx->pm_suspended = true;
> +}
> +
> +static void dwc3_imx_resume(struct dwc3_imx *dwc_imx, pm_message_t msg)
> +{
> +	struct dwc3	*dwc = &dwc_imx->dwc;
> +
> +	dwc_imx->pm_suspended = false;
> +	if (!dwc_imx->wakeup_pending)
> +		disable_irq_nosync(dwc_imx->irq);
> +
> +	dwc3_imx_wakeup_disable(dwc_imx);
> +
> +	/* Upon power loss any previous configuration is lost, restore it */
> +	dwc3_imx_configure_glue(dwc_imx);
> +
> +	if (dwc_imx->wakeup_pending) {
> +		dwc_imx->wakeup_pending = false;
> +		if (dwc->current_dr_role == DWC3_GCTL_PRTCAP_DEVICE)
> +			pm_runtime_put_autosuspend(dwc->dev);
> +		else
> +			/*
> +			 * Add wait for xhci switch from suspend
> +			 * clock to normal clock to detect connection.
> +			 */
> +			usleep_range(9000, 10000);
> +	}
> +}
> +
> +static int dwc3_imx_runtime_suspend(struct device *dev)
> +{
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +	struct dwc3_imx	*dwc_imx = to_dwc3_imx(dwc);
> +	int		ret;
> +
> +	dev_dbg(dev, "at %s\n", __func__);
> +
> +	ret = dwc3_runtime_suspend(dwc);
> +	if (ret)
> +		return ret;
> +
> +	dwc3_imx_suspend(dwc_imx, PMSG_AUTO_SUSPEND);
> +	return 0;
> +}
> +
> +static int dwc3_imx_runtime_resume(struct device *dev)
> +{
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +	struct dwc3_imx	*dwc_imx = to_dwc3_imx(dwc);
> +
> +	dev_dbg(dev, "at %s\n", __func__);
> +
> +	dwc3_imx_resume(dwc_imx, PMSG_AUTO_RESUME);
> +	return dwc3_runtime_resume(dwc);
> +}
> +
> +static int dwc3_imx_runtime_idle(struct device *dev)
> +{
> +	return dwc3_runtime_idle(dev_get_drvdata(dev));
> +}
> +
> +static int dwc3_imx_pm_suspend(struct device *dev)
> +{
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +	struct dwc3_imx *dwc_imx = to_dwc3_imx(dwc);
> +	int		ret;
> +
> +	dev_dbg(dev, "at %s\n", __func__);
> +
> +	ret = dwc3_pm_suspend(dwc);
> +	if (ret)
> +		return ret;
> +
> +	dwc3_imx_suspend(dwc_imx, PMSG_SUSPEND);
> +
> +	if (device_may_wakeup(dev)) {
> +		enable_irq_wake(dwc_imx->irq);
> +		device_set_out_band_wakeup(dev);
> +	} else {
> +		clk_disable_unprepare(dwc_imx->suspend_clk);
> +	}
> +
> +	clk_disable_unprepare(dwc_imx->hsio_clk);
> +
> +	return 0;
> +}
> +
> +static int dwc3_imx_pm_resume(struct device *dev)
> +{
> +	struct dwc3	*dwc = dev_get_drvdata(dev);
> +	struct dwc3_imx *dwc_imx = to_dwc3_imx(dwc);
> +	int		ret;
> +
> +	dev_dbg(dev, "at %s\n", __func__);
> +
> +	if (device_may_wakeup(dwc_imx->dev)) {
> +		disable_irq_wake(dwc_imx->irq);
> +	} else {
> +		ret = clk_prepare_enable(dwc_imx->suspend_clk);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = clk_prepare_enable(dwc_imx->hsio_clk);
> +	if (ret) {
> +		clk_disable_unprepare(dwc_imx->suspend_clk);
> +		return ret;
> +	}
> +
> +	dwc3_imx_resume(dwc_imx, PMSG_RESUME);
> +
> +	ret = dwc3_pm_resume(dwc);
> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static void dwc3_imx_complete(struct device *dev)
> +{
> +	dwc3_pm_complete(dev_get_drvdata(dev));
> +}
> +
> +static int dwc3_imx_prepare(struct device *dev)
> +{
> +	return dwc3_pm_prepare(dev_get_drvdata(dev));
> +}
> +
> +static const struct dev_pm_ops dwc3_imx_dev_pm_ops = {
> +	SYSTEM_SLEEP_PM_OPS(dwc3_imx_pm_suspend, dwc3_imx_pm_resume)
> +	RUNTIME_PM_OPS(dwc3_imx_runtime_suspend, dwc3_imx_runtime_resume,
> +		       dwc3_imx_runtime_idle)
> +	.complete = pm_sleep_ptr(dwc3_imx_complete),
> +	.prepare = pm_sleep_ptr(dwc3_imx_prepare),
> +};
> +
> +static const struct of_device_id dwc3_imx_of_match[] = {
> +	{ .compatible = "nxp,imx8mp-dwc3", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, dwc3_imx_of_match);
> +
> +static struct platform_driver dwc3_imx_driver = {
> +	.probe		= dwc3_imx_probe,
> +	.remove		= dwc3_imx_remove,
> +	.driver		= {
> +		.name	= "imx-dwc3",
> +		.pm	= pm_ptr(&dwc3_imx_dev_pm_ops),
> +		.of_match_table	= dwc3_imx_of_match,
> +	},
> +};
> +
> +module_platform_driver(dwc3_imx_driver);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("DesignWare USB3 i.MX Glue Layer");
>
> --
> 2.34.1
>

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