[4/7] phy: spacemit: support K1 USB2.0 PHY controller

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..f0c2a33f53cc810e71c6140ae957aa68a2b6ff0c
--- /dev/null
+++ b/drivers/phy/spacemit/Kconfig
@@ -0,0 +1,12 @@ 
+# 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 USB || USB_GADGET
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	select USB_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 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..acbf6a0ebad0ee6b53cc7fd89bad4780c7b7cab5
--- /dev/null
+++ b/drivers/phy/spacemit/phy-k1-usb2.c
@@ -0,0 +1,132 @@ 
+// 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
+
+#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_usb_phy_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_usb_phy_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",
+		.owner  = THIS_MODULE,
+		.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");