Re: [PATCH v2 3/4] phy: spacemit: support K1 USB2.0 PHY controller

[Vinod Koul <vkoul@kernel.org>]

Hi,

On 18-04-25, 21:19, Ze Huang wrote:
> Add support for SpacemiT K1 USB2.0 PHY.

Can you please add more details of this device, which SoC is this, and
what are the capablities of this phy

> 
> Signed-off-by: Ze Huang <huangze@whut.edu.cn>
> ---
>  drivers/phy/Kconfig                |   1 +
>  drivers/phy/Makefile               |   1 +
>  drivers/phy/spacemit/Kconfig       |  13 ++++
>  drivers/phy/spacemit/Makefile      |   2 +
>  drivers/phy/spacemit/phy-k1-usb2.c | 131 +++++++++++++++++++++++++++++++++++++
>  5 files changed, 148 insertions(+)
> 
> diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
> index 8d58efe998ec5fd50054eed2c90d6ecce6bd5dd8..fca589aa7926eb5bce14e99785cf32cf0395202e 100644
> --- a/drivers/phy/Kconfig
> +++ b/drivers/phy/Kconfig
> @@ -114,6 +114,7 @@ source "drivers/phy/renesas/Kconfig"
>  source "drivers/phy/rockchip/Kconfig"
>  source "drivers/phy/samsung/Kconfig"
>  source "drivers/phy/socionext/Kconfig"
> +source "drivers/phy/spacemit/Kconfig"
>  source "drivers/phy/st/Kconfig"
>  source "drivers/phy/starfive/Kconfig"
>  source "drivers/phy/sunplus/Kconfig"
> diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
> index e281442acc752820fe0bd638dfe38986a37c2a78..05993ff8a15daf7e2583b5f9b9b37ac584a30609 100644
> --- a/drivers/phy/Makefile
> +++ b/drivers/phy/Makefile
> @@ -34,6 +34,7 @@ obj-y					+= allwinner/	\
>  					   rockchip/	\
>  					   samsung/	\
>  					   socionext/	\
> +					   spacemit/	\
>  					   st/		\
>  					   starfive/	\
>  					   sunplus/	\
> diff --git a/drivers/phy/spacemit/Kconfig b/drivers/phy/spacemit/Kconfig
> new file mode 100644
> index 0000000000000000000000000000000000000000..0136aee2e8a2f5f484da136b26f80130794b992c
> --- /dev/null
> +++ b/drivers/phy/spacemit/Kconfig
> @@ -0,0 +1,13 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# Phy drivers for SpacemiT platforms
> +#
> +config PHY_SPACEMIT_K1_USB2
> +	tristate "SpacemiT K1 USB 2.0 PHY support"
> +	depends on (ARCH_SPACEMIT || COMPILE_TEST) && OF
> +	depends on COMMON_CLK
> +	depends on USB_COMMON
> +	select GENERIC_PHY
> +	help
> +	  Enable this to support K1 USB 2.0 PHY driver. This driver takes care of
> +	  enabling and clock setup and will be used by K1 udc/ehci/otg/xhci driver.
> diff --git a/drivers/phy/spacemit/Makefile b/drivers/phy/spacemit/Makefile
> new file mode 100644
> index 0000000000000000000000000000000000000000..fec0b425a948541b39b814caef0b05e1e002d92f
> --- /dev/null
> +++ b/drivers/phy/spacemit/Makefile
> @@ -0,0 +1,2 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +obj-$(CONFIG_PHY_SPACEMIT_K1_USB2)		+= phy-k1-usb2.o
> diff --git a/drivers/phy/spacemit/phy-k1-usb2.c b/drivers/phy/spacemit/phy-k1-usb2.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..4a5684f3185f61f9d865b0fb52644bb280756d00
> --- /dev/null
> +++ b/drivers/phy/spacemit/phy-k1-usb2.c
> @@ -0,0 +1,131 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * SpacemiT K1 USB 2.0 PHY driver
> + *
> + * Copyright (C) 2025 SpacemiT (Hangzhou) Technology Co. Ltd
> + * Copyright (C) 2025 Ze Huang <huangze@whut.edu.cn>
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/iopoll.h>
> +#include <linux/platform_device.h>
> +#include <linux/usb/of.h>
> +
> +#define USB2_PHY_REG01			0x04
> +#define  USB2_PHY_REG01_VAL		0x60ef
> +#define  USB2_PHY_REG01_PLL_IS_READY	BIT(0)
> +#define USB2_PHY_REG04			0x10
> +#define  USB2_PHY_REG04_AUTO_CLEAR_DIS	BIT(2)
> +#define USB2_PHY_REG0D			0x34
> +#define  USB2_PHY_REG0D_VAL		0x1c
> +#define USB2_PHY_REG26			0x98
> +#define  USB2_PHY_REG26_VAL		0xbec4

What are these values referred to, why are you defining fixed values for
driver to use and not set the register bits?
> +
> +#define USB2D_CTRL_RESET_TIME_MS	50
> +
> +struct spacemit_usb2phy {
> +	struct phy	*phy;
> +	struct clk	*clk;
> +	void __iomem	*base;
> +};
> +
> +static int spacemit_usb2phy_init(struct phy *phy)
> +{
> +	struct spacemit_usb2phy *sphy = phy_get_drvdata(phy);
> +	void __iomem *base = sphy->base;
> +	u32 val;
> +	int ret;
> +
> +	ret = clk_prepare_enable(sphy->clk);
> +	if (ret) {
> +		dev_err(&phy->dev, "failed to enable clock\n");
> +		return ret;
> +	}
> +
> +	/*
> +	 * make sure the usb controller is not under reset process before
> +	 * any configuration
> +	 */
> +	usleep_range(150, 200);
> +	writel(USB2_PHY_REG26_VAL, base + USB2_PHY_REG26); /* 24M ref clk */
> +
> +	ret = read_poll_timeout(readl, val, (val & USB2_PHY_REG01_PLL_IS_READY),
> +				500, USB2D_CTRL_RESET_TIME_MS * 1000, true,
> +				base + USB2_PHY_REG01);
> +	if (ret) {
> +		dev_err(&phy->dev, "wait PHY_REG01[PLLREADY] timeout\n");
> +		return ret;
> +	}
> +
> +	/* release usb2 phy internal reset and enable clock gating */
> +	writel(USB2_PHY_REG01_VAL, base + USB2_PHY_REG01);
> +	writel(USB2_PHY_REG0D_VAL, base + USB2_PHY_REG0D);
> +
> +	/* auto clear host disc */
> +	val = readl(base + USB2_PHY_REG04);
> +	val |= USB2_PHY_REG04_AUTO_CLEAR_DIS;
> +	writel(val, base + USB2_PHY_REG04);
> +
> +	return 0;
> +}
> +
> +static int spacemit_usb2phy_exit(struct phy *phy)
> +{
> +	struct spacemit_usb2phy *sphy = phy_get_drvdata(phy);
> +
> +	clk_disable_unprepare(sphy->clk);
> +
> +	return 0;
> +}
> +
> +static const struct phy_ops spacemit_usb2phy_ops = {
> +	.init = spacemit_usb2phy_init,
> +	.exit = spacemit_usb2phy_exit,
> +	.owner = THIS_MODULE,
> +};
> +
> +static int spacemit_usb2phy_probe(struct platform_device *pdev)
> +{
> +	struct phy_provider *phy_provider;
> +	struct device *dev = &pdev->dev;
> +	struct spacemit_usb2phy *sphy;
> +
> +	sphy = devm_kzalloc(dev, sizeof(*sphy), GFP_KERNEL);
> +	if (!sphy)
> +		return -ENOMEM;
> +
> +	sphy->clk = devm_clk_get_prepared(&pdev->dev, NULL);
> +	if (IS_ERR(sphy->clk))
> +		return dev_err_probe(dev, PTR_ERR(sphy->clk), "Failed to get clock\n");
> +
> +	sphy->base = devm_platform_ioremap_resource(pdev, 0);
> +	if (IS_ERR(sphy->base))
> +		return PTR_ERR(sphy->base);
> +
> +	sphy->phy = devm_phy_create(dev, NULL, &spacemit_usb2phy_ops);
> +	if (IS_ERR(sphy->phy))
> +		return dev_err_probe(dev, PTR_ERR(sphy->phy), "Failed to create phy\n");
> +
> +	phy_set_drvdata(sphy->phy, sphy);
> +	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 spacemit_usb2phy_dt_match[] = {
> +	{ .compatible = "spacemit,k1-usb2-phy", },
> +	{ /* sentinal */ }
> +};
> +MODULE_DEVICE_TABLE(of, spacemit_usb2phy_dt_match);
> +
> +static struct platform_driver spacemit_usb2_phy_driver = {
> +	.probe	= spacemit_usb2phy_probe,
> +	.driver = {
> +		.name   = "spacemit-usb2-phy",
> +		.of_match_table = spacemit_usb2phy_dt_match,
> +	},
> +};
> +module_platform_driver(spacemit_usb2_phy_driver);
> +
> +MODULE_DESCRIPTION("Spacemit USB 2.0 PHY driver");
> +MODULE_LICENSE("GPL");
> 
> -- 
> 2.49.0
> 
> 
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-- 
~Vinod