Re: [PATCH v2 2/2] usb: dwc3: eic7700: Add EIC7700 USB driver

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Wed, Jul 30, 2025, zhangsenchuan@eswincomputing.com wrote:
> From: Senchuan Zhang <zhangsenchuan@eswincomputing.com>
> 
> Add the eic7700 usb driver, which is responsible for
> identifying,configuring and connecting usb devices.
> 
> Co-developed-by: Wei Yang <yangwei1@eswincomputing.com>
> Signed-off-by: Wei Yang <yangwei1@eswincomputing.com>
> Signed-off-by: Senchuan Zhang <zhangsenchuan@eswincomputing.com>
> ---
>  drivers/usb/dwc3/Kconfig        |  11 ++
>  drivers/usb/dwc3/Makefile       |   1 +
>  drivers/usb/dwc3/dwc3-eic7700.c | 207 ++++++++++++++++++++++++++++++++
>  3 files changed, 219 insertions(+)
>  create mode 100644 drivers/usb/dwc3/dwc3-eic7700.c
> 
> diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
> index 310d182e10b5..19657cfb5d08 100644
> --- a/drivers/usb/dwc3/Kconfig
> +++ b/drivers/usb/dwc3/Kconfig
> @@ -189,4 +189,15 @@ config USB_DWC3_RTK
>  	  or dual-role mode.
>  	  Say 'Y' or 'M' if you have such device.
>  
> +config USB_DWC3_EIC7700
> +	tristate "Eswin Platforms"
> +	depends on OF
> +	depends on USB=y || USB=USB_DWC3
> +	default USB_DWC3
> +	help
> +	  The usb controller on eic7700 SoC.
> +	  support of USB2/3 functionality
> +	  in Eswin platforms.
> +	  say 'Y' or 'M' if you have one such device.
> +
>  endif
> diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
> index 830e6c9e5fe0..05f582103f8b 100644
> --- a/drivers/usb/dwc3/Makefile
> +++ b/drivers/usb/dwc3/Makefile
> @@ -57,3 +57,4 @@ obj-$(CONFIG_USB_DWC3_IMX8MP)		+= dwc3-imx8mp.o
>  obj-$(CONFIG_USB_DWC3_XILINX)		+= dwc3-xilinx.o
>  obj-$(CONFIG_USB_DWC3_OCTEON)		+= dwc3-octeon.o
>  obj-$(CONFIG_USB_DWC3_RTK)		+= dwc3-rtk.o
> +obj-$(CONFIG_USB_DWC3_EIC7700)		+= dwc3-eic7700.o
> diff --git a/drivers/usb/dwc3/dwc3-eic7700.c b/drivers/usb/dwc3/dwc3-eic7700.c
> new file mode 100644
> index 000000000000..337f6c1cbe66
> --- /dev/null
> +++ b/drivers/usb/dwc3/dwc3-eic7700.c
> @@ -0,0 +1,207 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Eswin Specific Glue layer
> + *
> + * Copyright 2025, Beijing ESWIN Computing Technology Co., Ltd.
> + *
> + * Authors: Wei Yang <yangwei1@eswincomputing.com>
> + *          Senchuan Zhang <zhangsenchuan@eswincomputing.com>
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +#include <linux/clk.h>
> +#include <linux/of.h>
> +#include <linux/of_platform.h>
> +#include <linux/reset.h>
> +#include <linux/usb.h>
> +#include <linux/pm.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/regmap.h>
> +
> +#define HSP_USB_VBUS_FSEL 0x2a
> +#define HSP_USB_MPLL_DEFAULT 0x0
> +
> +#define HSP_USB_BUS_FILTER_EN (0x1 << 0)
> +#define HSP_USB_BUS_CLKEN_GM (0x1 << 9)
> +#define HSP_USB_BUS_CLKEN_GS (0x1 << 16)
> +#define HSP_USB_BUS_SW_RST (0x1 << 24)
> +#define HSP_USB_BUS_CLK_EN (0x1 << 28)
> +
> +#define HSP_USB_AXI_LP_XM_CSYSREQ (0x1 << 0)
> +#define HSP_USB_AXI_LP_XS_CSYSREQ (0x1 << 16)
> +
> +struct dwc3_eswin {
> +	int num_clks;
> +	struct device *dev;
> +	struct clk_bulk_data *clks;
> +	struct reset_control *vaux_rst;
> +};
> +
> +static int dwc_usb_clk_init(struct device *dev)
> +{
> +	struct regmap *regmap;
> +	u32 hsp_usb_bus;
> +	u32 hsp_usb_axi_lp;
> +	u32 hsp_usb_vbus_freq;
> +	u32 hsp_usb_mpll;
> +	u32 args[4];
> +
> +	regmap = syscon_regmap_lookup_by_phandle_args(dev->of_node,
> +						      "eswin,hsp-sp-csr", 4,
> +						      args);
> +	if (IS_ERR(regmap)) {
> +		dev_err(dev, "No hsp-sp-csr phandle specified\n");
> +		return PTR_ERR(regmap);
> +	}
> +
> +	hsp_usb_bus       = args[0];
> +	hsp_usb_axi_lp    = args[1];
> +	hsp_usb_vbus_freq = args[2];
> +	hsp_usb_mpll      = args[3];
> +
> +	/*
> +	 * usb clock init
> +	 * ref clock is 24M, below need to be set to satisfy
> +	 * usb phy requirement(125M)
> +	 */
> +	regmap_write(regmap, hsp_usb_vbus_freq, HSP_USB_VBUS_FSEL);
> +	regmap_write(regmap, hsp_usb_mpll, HSP_USB_MPLL_DEFAULT);
> +	/*
> +	 * reset usb core and usb phy
> +	 */
> +	regmap_write(regmap, hsp_usb_bus, HSP_USB_BUS_FILTER_EN |
> +		     HSP_USB_BUS_CLKEN_GM | HSP_USB_BUS_CLKEN_GS |
> +		     HSP_USB_BUS_SW_RST | HSP_USB_BUS_CLK_EN);
> +	regmap_write(regmap, hsp_usb_axi_lp, HSP_USB_AXI_LP_XM_CSYSREQ |
> +		     HSP_USB_AXI_LP_XS_CSYSREQ);
> +
> +	return 0;
> +}
> +
> +static int dwc3_eswin_probe(struct platform_device *pdev)
> +{
> +	struct dwc3_eswin *eswin;
> +	struct device *dev = &pdev->dev;
> +	struct device_node *np = dev->of_node;
> +	int ret;
> +
> +	eswin = devm_kzalloc(dev, sizeof(*eswin), GFP_KERNEL);
> +	if (!eswin)
> +		return -ENOMEM;
> +
> +	eswin->dev = dev;
> +	platform_set_drvdata(pdev, eswin);
> +
> +	eswin->num_clks = devm_clk_bulk_get_all_enabled(dev, &eswin->clks);
> +	if (eswin->num_clks < 0)
> +		return dev_err_probe(dev, eswin->num_clks,
> +				     "Failed to get usb clocks\n");
> +
> +	eswin->vaux_rst = devm_reset_control_get(dev, "vaux");
> +	if (IS_ERR(eswin->vaux_rst))
> +		return dev_err_probe(dev, PTR_ERR(eswin->vaux_rst),
> +				     "Failed to get vaux reset\n");
> +
> +	ret = reset_control_deassert(eswin->vaux_rst);
> +	if (ret)
> +		return dev_err_probe(eswin->dev, ret,
> +				     "Failed to deassert reset\n");
> +
> +	ret = dwc_usb_clk_init(dev);
> +	if (ret) {
> +		dev_err(eswin->dev, "Failed to clk init: %d\n", ret);
> +		goto reset_assert;
> +	}
> +
> +	pm_runtime_set_active(dev);
> +	pm_runtime_enable(dev);
> +
> +	ret = pm_runtime_get_sync(dev);
> +	if (ret < 0) {
> +		dev_err(dev, "get_sync failed with err %d\n", ret);
> +		goto disable_pm;
> +	}
> +
> +	/* Allocate and initialize the core */
> +	ret = of_platform_populate(np, NULL, NULL, dev);

Can we use the dwc3 core as a library now instead of this as noted by
Krishna? Check dwc3-qcom for reference.

> +	if (ret) {
> +		dev_err(dev, "failed to create dwc3 core: %d\n", ret);
> +		goto put_pm;
> +	}
> +
> +	return ret;
> +
> +put_pm:
> +	pm_runtime_put_sync(dev);
> +disable_pm:
> +	pm_runtime_disable(dev);
> +reset_assert:
> +	reset_control_assert(eswin->vaux_rst);
> +
> +	return ret;
> +}
> +
> +static void dwc3_eswin_remove(struct platform_device *pdev)
> +{
> +	struct dwc3_eswin *eswin = platform_get_drvdata(pdev);
> +	struct device *dev = &pdev->dev;
> +
> +	of_platform_depopulate(dev);
> +
> +	pm_runtime_put_sync(dev);
> +	pm_runtime_disable(dev);
> +	reset_control_assert(eswin->vaux_rst);
> +}
> +
> +static int __maybe_unused dwc3_eswin_runtime_suspend(struct device *dev)
> +{
> +	struct dwc3_eswin *eswin = dev_get_drvdata(dev);
> +
> +	clk_bulk_disable_unprepare(eswin->num_clks, eswin->clks);
> +
> +	return 0;
> +}
> +
> +static int __maybe_unused dwc3_eswin_runtime_resume(struct device *dev)
> +{
> +	struct dwc3_eswin *eswin = dev_get_drvdata(dev);
> +	int ret;
> +
> +	ret = clk_bulk_prepare_enable(eswin->num_clks, eswin->clks);
> +	if (ret) {
> +		dev_err(dev, "failed to enable clocks: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct dev_pm_ops dwc3_eswin_dev_pm_ops = {
> +	SET_RUNTIME_PM_OPS(dwc3_eswin_runtime_suspend,
> +			   dwc3_eswin_runtime_resume, NULL)

You don't have system pm?

> +};
> +
> +static const struct of_device_id eswin_dwc3_match[] = {
> +	{ .compatible = "eswin,eic7700-dwc3" },
> +	{},
> +};
> +
> +MODULE_DEVICE_TABLE(of, eswin_dwc3_match);
> +
> +static struct platform_driver dwc3_eswin_driver = {
> +	.probe = dwc3_eswin_probe,
> +	.remove = dwc3_eswin_remove,
> +	.driver = {
> +		.name = "eic7700-dwc3",
> +		.pm	= &dwc3_eswin_dev_pm_ops,

Use pm_ptr() and remove the __maybe_unused tags.

> +		.of_match_table = eswin_dwc3_match,
> +	},
> +};
> +
> +module_platform_driver(dwc3_eswin_driver);
> +
> +MODULE_AUTHOR("Wei Yang <yangwei1@eswincomputing.com");
> +MODULE_AUTHOR("Senchuan Zhang <zhangsenchuan@eswincomputing.com");
> +MODULE_LICENSE("GPL");
> +MODULE_DESCRIPTION("DesignWare USB3 ESWIN Glue Layer");
> -- 
> 2.25.1
> 

BR,
Thinh