Re: [PATCH 05/12] phy: add a driver for T-Head TH1520 USB PHY

[Vinod Koul <vkoul@kernel.org>]

On 07-05-26, 16:17, Icenowy Zheng wrote:
> The USB PHY on T-Head TH1520 SoC is a Synopsys USB 3.0 FemtoPHY, with
> some PHY parameters exported as another system controller along with it.
> 
> As a few PHY parameters' default value isn't ready to work, add a driver
> configuring them before letting the PHY run, in addition to
> clock/reset/regulator management.

Is there any dependency on the rest of series, if not please split up!

Some warnings flagged by sashiko, please check
https://sashiko.dev/#/patchset/20260507081710.4090814-1-zhengxingda%40iscas.ac.cn


> 
> Signed-off-by: Icenowy Zheng <zhengxingda@iscas.ac.cn>
> ---
>  drivers/phy/Kconfig                |   1 +
>  drivers/phy/Makefile               |   1 +
>  drivers/phy/thead/Kconfig          |  12 ++
>  drivers/phy/thead/Makefile         |   2 +
>  drivers/phy/thead/phy-th1520-usb.c | 197 +++++++++++++++++++++++++++++
>  5 files changed, 213 insertions(+)
>  create mode 100644 drivers/phy/thead/Kconfig
>  create mode 100644 drivers/phy/thead/Makefile
>  create mode 100644 drivers/phy/thead/phy-th1520-usb.c
> 
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 227b9a4c612e8..ea1a52e14b839 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -164,6 +164,7 @@ source "drivers/phy/st/Kconfig"
>  source "drivers/phy/starfive/Kconfig"
>  source "drivers/phy/sunplus/Kconfig"
>  source "drivers/phy/tegra/Kconfig"
> +source "drivers/phy/thead/Kconfig"
>  source "drivers/phy/ti/Kconfig"
>  source "drivers/phy/xilinx/Kconfig"
>  
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index f49d83f00a3d8..4604522548c91 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -48,5 +48,6 @@ obj-$(CONFIG_GENERIC_PHY)		+= allwinner/	\
>  					   starfive/	\
>  					   sunplus/	\
>  					   tegra/	\
> +					   thead/	\
>  					   ti/		\
>  					   xilinx/
> diff --git a/drivers/phy/thead/Kconfig b/drivers/phy/thead/Kconfig
> new file mode 100644
> index 0000000000000..14012db5973c4
> --- /dev/null
> +++ b/drivers/phy/thead/Kconfig
> @@ -0,0 +1,12 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +config PHY_TH1520_USB
> +	tristate "USB PHY driver for T-Head TH1520 SoC"
> +	depends on ARCH_THEAD || COMPILE_TEST
> +	depends on COMMON_CLK
> +	depends on HAS_IOMEM
> +	depends on OF
> +	depends on RESET_CONTROLLER
> +	select GENERIC_PHY
> +	default ARCH_THEAD

Why should this be default?

> +	help
> +	  Enable support for the USB PHY on the T-Head TH1520 SoC.
> diff --git a/drivers/phy/thead/Makefile b/drivers/phy/thead/Makefile
> new file mode 100644
> index 0000000000000..5b459bc7004bd
> --- /dev/null
> +++ b/drivers/phy/thead/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +obj-$(CONFIG_PHY_TH1520_USB) += phy-th1520-usb.o
> diff --git a/drivers/phy/thead/phy-th1520-usb.c b/drivers/phy/thead/phy-th1520-usb.c
> new file mode 100644
> index 0000000000000..c87bd779bbb74
> --- /dev/null
> +++ b/drivers/phy/thead/phy-th1520-usb.c
> @@ -0,0 +1,197 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (C) 2026 Institute of Software, Chinese Academy of Sciences (ISCAS)
> + *
> + * Authors:
> + * Icenowy Zheng <zhengxingda@iscas.ac.cn>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/phy/phy.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/reset.h>
> +
> +#define USB_SYSCON_OFFSET		0xf000
> +
> +/* All the below registers are in the USB syscon region */
> +#define USB_CLK_GATE_STS		0x0
> +#define USB_LOGIC_ANALYZER_TRACE_STS0	0x4
> +#define USB_LOGIC_ANALYZER_TRACE_STS1	0x8
> +#define USB_GPIO			0xc
> +#define USB_DEBUG_STS0			0x10
> +#define USB_DEBUG_STS1			0x14
> +#define USB_DEBUG_STS2			0x18
> +#define USBCTL_CLK_CTRL0		0x1c
> +#define USBPHY_CLK_CTRL1		0x20
> +#define USBPHY_TEST_CTRL0		0x24
> +#define USBPHY_TEST_CTRL1		0x28
> +#define USBPHY_TEST_CTRL2		0x2c
> +#define USBPHY_TEST_CTRL3		0x30
> +#define USB_SSP_EN			0x34
> +#define USB_HADDR_SEL			0x38
> +#define USB_SYS				0x3c
> +#define USB_HOST_STATUS			0x40
> +#define USB_HOST_CTRL			0x44
> +#define USBPHY_HOST_CTRL		0x48
> +#define USBPHY_HOST_STATUS		0x4c
> +#define USB_TEST_REG0			0x50
> +#define USB_TEST_REG1			0x54
> +#define USB_TEST_REG2			0x58
> +#define USB_TEST_REG3			0x5c

Why do need these test registers, they seem unused?

> +
> +#define USB_SYS_COMMONONN		BIT(0)
> +
> +#define USB_SSP_EN_REF_SSP_EN		BIT(0)
> +
> +struct th1520_usb_phy {
> +	struct platform_device *pdev;
> +	struct phy *phy;
> +	struct regmap *regmap;
> +	struct clk *ref_clk;
> +	struct reset_control *phy_reset;
> +};
> +
> +static int th1520_usb_phy_init(struct phy *phy)
> +{
> +	struct th1520_usb_phy *th1520_phy = phy_get_drvdata(phy);
> +	int ret;
> +
> +	ret = clk_prepare_enable(th1520_phy->ref_clk);
> +	if (ret)
> +		return ret;
> +
> +	ret = reset_control_assert(th1520_phy->phy_reset);
> +	if (ret)
> +		goto err_disable_clk;
> +
> +	/*
> +	 * Do some initial PHY setup:
> +	 * - Set COMMONONN to allow the PHY to automatically power down.
> +	 * - Set REF_SSP_EN to enable feeding reference clock to SuperSpeed
> +	 *   PHY clock PLL.
> +	 */
> +	regmap_set_bits(th1520_phy->regmap, USB_SYS, USB_SYS_COMMONONN);
> +	regmap_set_bits(th1520_phy->regmap, USB_SSP_EN, USB_SSP_EN_REF_SSP_EN);
> +
> +	ret = reset_control_deassert(th1520_phy->phy_reset);
> +	if (ret)
> +		goto err_disable_clk;
> +
> +	udelay(10);
> +
> +	return 0;
> +
> +err_disable_clk:
> +	clk_disable_unprepare(th1520_phy->ref_clk);
> +	return ret;
> +}
> +
> +static int th1520_usb_phy_exit(struct phy *phy)
> +{
> +	struct th1520_usb_phy *th1520_phy = phy_get_drvdata(phy);
> +	int ret;
> +
> +	ret = reset_control_assert(th1520_phy->phy_reset);
> +	if (ret)
> +		return ret;
> +
> +	clk_disable_unprepare(th1520_phy->ref_clk);
> +
> +	return 0;
> +}
> +
> +static const struct phy_ops th1520_usb_phy_ops = {
> +	.init		= th1520_usb_phy_init,
> +	.exit		= th1520_usb_phy_exit,
> +	.owner		= THIS_MODULE,
> +};
> +
> +static const struct regmap_config phy_regmap_config = {
> +	.reg_bits = 32,
> +	.val_bits = 32,
> +	.reg_stride = 4,
> +	.max_register = USB_TEST_REG3,
> +};
> +
> +static int th1520_usb_phy_probe(struct platform_device *pdev)
> +{
> +	struct phy_provider *phy_provider;
> +	struct device *dev = &pdev->dev;
> +	struct th1520_usb_phy *th1520_phy;
> +	struct reset_control *bus_reset;
> +	void __iomem *base;
> +	int ret;
> +
> +	th1520_phy = devm_kzalloc(dev, sizeof(*th1520_phy), GFP_KERNEL);
> +	if (!th1520_phy)
> +		return -ENOMEM;
> +
> +	th1520_phy->pdev = pdev;
> +
> +	base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(base))
> +		return PTR_ERR(base);
> +
> +	th1520_phy->ref_clk = devm_clk_get(dev, "ref");
> +	if (IS_ERR(th1520_phy->ref_clk))
> +		return PTR_ERR(th1520_phy->ref_clk);
> +
> +	/* De-assert the bus reset and leave it that way */
> +	bus_reset = devm_reset_control_get_exclusive_deasserted(dev, "bus");
> +	if (IS_ERR(bus_reset))
> +		return PTR_ERR(bus_reset);
> +
> +	th1520_phy->phy_reset = devm_reset_control_get_exclusive(dev, "phy");
> +	if (IS_ERR(th1520_phy->phy_reset))
> +		return PTR_ERR(th1520_phy->phy_reset);
> +
> +	/*
> +	 * Schematics of several boards (Lichee Module 4A/Milk-V Meles)
> +	 * describe this power rail as always-on.
> +	 */
> +	ret = devm_regulator_get_enable(dev, "avdd33-usb3");
> +	if (ret)
> +		return ret;
> +
> +	th1520_phy->regmap = devm_regmap_init_mmio_clk(dev, "bus",
> +						       base + USB_SYSCON_OFFSET,
> +						       &phy_regmap_config);
> +	if (IS_ERR(th1520_phy->regmap))
> +		return dev_err_probe(dev, PTR_ERR(th1520_phy->regmap),
> +				     "Failed to init regmap\n");
> +
> +	th1520_phy->phy = devm_phy_create(dev, dev->of_node, &th1520_usb_phy_ops);
> +	if (IS_ERR(th1520_phy->phy)) {
> +		dev_err(dev, "failed to create PHY\n");
> +		return PTR_ERR(th1520_phy->phy);
> +	}
> +
> +	phy_set_drvdata(th1520_phy->phy, th1520_phy);
> +
> +	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
> +
> +	return PTR_ERR_OR_ZERO(phy_provider);
> +}
> +
> +static const struct of_device_id th1520_usb_phy_of_table[] = {
> +	{ .compatible = "thead,th1520-usb-phy" },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, th1520_usb_phy_of_table);
> +
> +static struct platform_driver th1520_usb_phy_driver = {
> +	.driver = {
> +		.name = "th1520-usb-phy",
> +		.of_match_table = th1520_usb_phy_of_table,
> +	},
> +	.probe = th1520_usb_phy_probe,
> +};
> +
> +module_platform_driver(th1520_usb_phy_driver);
> +
> +MODULE_DESCRIPTION("T-Head TH1520 USB PHY driver");
> +MODULE_LICENSE("GPL");
> -- 
> 2.52.0

-- 
~Vinod