phy: usb: Add driver for Canaan K230 USB 2.0 PHY

Add driver for the USB 2.0 PHY in Canaan K230 SoC, which supports PHY
initialization and power management.

Add Kconfig/Makefile under drivers/phy/canaan/.

Signed-off-by: Jiayu Du <jiayu.riscv@isrc.iscas.ac.cn>
Link: https://patch.msgid.link/20260121145526.14672-4-jiayu.riscv@isrc.iscas.ac.cn
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/Kconfig

@@ -139,6 +139,7 @@ source "drivers/phy/amlogic/Kconfig"
 source "drivers/phy/apple/Kconfig"
 source "drivers/phy/broadcom/Kconfig"
 source "drivers/phy/cadence/Kconfig"
+source "drivers/phy/canaan/Kconfig"
 source "drivers/phy/freescale/Kconfig"
 source "drivers/phy/hisilicon/Kconfig"
 source "drivers/phy/ingenic/Kconfig"

drivers/phy/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_GENERIC_PHY)		+= allwinner/	\
 					   apple/	\
 					   broadcom/	\
 					   cadence/	\
+					   canaan/	\
 					   freescale/	\
 					   hisilicon/	\
 					   ingenic/	\

drivers/phy/canaan/Kconfig

@@ -0,0 +1,14 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Canaan platforms
+#
+config PHY_CANAAN_USB
+	tristate "Canaan USB2 PHY Driver"
+	depends on (ARCH_CANAAN || COMPILE_TEST) && OF
+	select GENERIC_PHY
+	help
+	Enable this driver to support the USB 2.0 PHY controller
+	on Canaan K230 RISC-V SoCs. This PHY controller
+	provides physical layer functionality for USB 2.0 devices.
+	If you have a Canaan K230 board and need USB 2.0 support,
+	say Y or M here.

drivers/phy/canaan/Makefile

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_PHY_CANAAN_USB)		+= phy-k230-usb.o

drivers/phy/canaan/phy-k230-usb.c

@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Canaan usb PHY driver
+ *
+ * Copyright (C) 2026 Jiayu Du <jiayu.riscv@isrc.iscas.ac.cn>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+
+#define MAX_PHYS		2
+
+/* Register offsets within the HiSysConfig system controller */
+#define K230_USB0_TEST_REG_BASE     0x70
+#define K230_USB0_CTL_REG_BASE      0xb0
+#define K230_USB1_TEST_REG_BASE     0x90
+#define K230_USB1_CTL_REG_BASE      0xb8
+
+/* Relative offsets within each PHY's control/test block */
+#define CTL0_OFFSET		0x00
+#define CTL1_OFFSET		0x04
+#define TEST_CTL3_OFFSET	0x0c
+
+/* Bit definitions for TEST_CTL3 */
+#define USB_IDPULLUP0		BIT(4)
+#define USB_DMPULLDOWN0		BIT(8)
+#define USB_DPPULLDOWN0		BIT(9)
+
+/* USB control register 0 in HiSysConfig system controller */
+/* PLL Integral Path Tune */
+#define USB_CTL0_PLLITUNE_MASK		GENMASK(23, 22)
+
+/* PLL Proportional Path Tune */
+#define USB_CTL0_PLLPTUNE_MASK		GENMASK(21, 18)
+
+/* PLL Bandwidth Adjustment */
+#define USB_CTL0_PLLBTUNE_MASK		GENMASK(17, 17)
+
+/* VReg18 Bypass Control */
+#define USB_CTL0_VREGBYPASS_MASK	GENMASK(16, 16)
+
+/* Retention Mode Enable */
+#define USB_CTL0_RETENABLEN_MASK	GENMASK(15, 15)
+
+/* Reserved Request Input */
+#define USB_CTL0_RESREQIN_MASK		GENMASK(14, 14)
+
+/* External VBUS Valid Select */
+#define USB_CTL0_VBUSVLDEXTSEL0_MASK	GENMASK(13, 13)
+
+/* OTG Block Disable Control */
+#define USB_CTL0_OTGDISABLE0_MASK	GENMASK(12, 12)
+
+/* Drive VBUS Enable */
+#define USB_CTL0_DRVVBUS0_MASK		GENMASK(11, 11)
+
+/* Autoresume Mode Enable */
+#define USB_CTL0_AUTORSMENB0_MASK	GENMASK(10, 10)
+
+/* HS Transceiver Asynchronous Control */
+#define USB_CTL0_HSXCVREXTCTL0_MASK	GENMASK(9, 9)
+
+/* USB 1.1 Transmit Data */
+#define USB_CTL0_FSDATAEXT0_MASK	GENMASK(8, 8)
+
+/* USB 1.1 SE0 Generation */
+#define USB_CTL0_FSSE0EXT0_MASK		GENMASK(7, 7)
+
+/* USB 1.1 Data Enable */
+#define USB_CTL0_TXENABLEN0_MASK	GENMASK(6, 6)
+
+/* Disconnect Threshold */
+#define USB_CTL0_COMPDISTUNE0_MASK	GENMASK(5, 3)
+
+/* Squelch Threshold */
+#define USB_CTL0_SQRXTUNE0_MASK		GENMASK(2, 0)
+
+/* USB control register 1 in HiSysConfig system controller */
+/* Data Detect Voltage */
+#define USB_CTL1_VDATREFTUNE0_MASK	GENMASK(23, 22)
+
+/* VBUS Valid Threshold */
+#define USB_CTL1_OTGTUNE0_MASK		GENMASK(21, 19)
+
+/* Transmitter High-Speed Crossover */
+#define USB_CTL1_TXHSXVTUNE0_MASK	GENMASK(18, 17)
+
+/* FS/LS Source Impedance */
+#define USB_CTL1_TXFSLSTUNE0_MASK	GENMASK(16, 13)
+
+/* HS DC Voltage Level */
+#define USB_CTL1_TXVREFTUNE0_MASK	GENMASK(12, 9)
+
+/* HS Transmitter Rise/Fall Time */
+#define USB_CTL1_TXRISETUNE0_MASK	GENMASK(8, 7)
+
+/* USB Source Impedance */
+#define USB_CTL1_TXRESTUNE0_MASK	GENMASK(6, 5)
+
+/* HS Transmitter Pre-Emphasis Current Control */
+#define USB_CTL1_TXPREEMPAMPTUNE0_MASK	GENMASK(4, 3)
+
+/* HS Transmitter Pre-Emphasis Duration Control */
+#define USB_CTL1_TXPREEMPPULSETUNE0_MASK	GENMASK(2, 2)
+
+/* charging detection */
+#define USB_CTL1_CHRGSRCPUENB0_MASK	GENMASK(1, 0)
+
+#define K230_PHY_CTL0_VAL \
+( \
+	FIELD_PREP(USB_CTL0_PLLITUNE_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_PLLPTUNE_MASK, 0xc) | \
+	FIELD_PREP(USB_CTL0_PLLBTUNE_MASK, 0x1) | \
+	FIELD_PREP(USB_CTL0_VREGBYPASS_MASK, 0x1) | \
+	FIELD_PREP(USB_CTL0_RETENABLEN_MASK, 0x1) | \
+	FIELD_PREP(USB_CTL0_RESREQIN_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_VBUSVLDEXTSEL0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_OTGDISABLE0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_DRVVBUS0_MASK, 0x1) | \
+	FIELD_PREP(USB_CTL0_AUTORSMENB0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_HSXCVREXTCTL0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_FSDATAEXT0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_FSSE0EXT0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_TXENABLEN0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL0_COMPDISTUNE0_MASK, 0x3) | \
+	FIELD_PREP(USB_CTL0_SQRXTUNE0_MASK, 0x3) \
+)
+
+#define K230_PHY_CTL1_VAL \
+( \
+	FIELD_PREP(USB_CTL1_VDATREFTUNE0_MASK, 0x1) | \
+	FIELD_PREP(USB_CTL1_OTGTUNE0_MASK, 0x3) | \
+	FIELD_PREP(USB_CTL1_TXHSXVTUNE0_MASK, 0x3) | \
+	FIELD_PREP(USB_CTL1_TXFSLSTUNE0_MASK, 0x3) | \
+	FIELD_PREP(USB_CTL1_TXVREFTUNE0_MASK, 0x3) | \
+	FIELD_PREP(USB_CTL1_TXRISETUNE0_MASK, 0x1) | \
+	FIELD_PREP(USB_CTL1_TXRESTUNE0_MASK, 0x1) | \
+	FIELD_PREP(USB_CTL1_TXPREEMPAMPTUNE0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL1_TXPREEMPPULSETUNE0_MASK, 0x0) | \
+	FIELD_PREP(USB_CTL1_CHRGSRCPUENB0_MASK, 0x0) \
+)
+
+struct k230_usb_phy_instance {
+	struct k230_usb_phy_global *global;
+	struct phy *phy;
+	u32 test_offset;
+	u32 ctl_offset;
+	int index;
+};
+
+struct k230_usb_phy_global {
+	struct k230_usb_phy_instance phys[MAX_PHYS];
+	void __iomem *base;
+};
+
+static int k230_usb_phy_power_on(struct phy *phy)
+{
+	struct k230_usb_phy_instance *inst = phy_get_drvdata(phy);
+	struct k230_usb_phy_global *global = inst->global;
+	void __iomem *base = global->base;
+	u32 val;
+
+	/* Apply recommended settings */
+	writel(K230_PHY_CTL0_VAL, base + inst->ctl_offset + CTL0_OFFSET);
+	writel(K230_PHY_CTL1_VAL, base + inst->ctl_offset + CTL1_OFFSET);
+
+	/* Configure test register (pull-ups/pull-downs) */
+	val = readl(base + inst->test_offset + TEST_CTL3_OFFSET);
+	val |= USB_IDPULLUP0;
+
+	if (inst->index == 1)
+		val |= (USB_DMPULLDOWN0 | USB_DPPULLDOWN0);
+	else
+		val &= ~(USB_DMPULLDOWN0 | USB_DPPULLDOWN0);
+
+	writel(val, base + inst->test_offset + TEST_CTL3_OFFSET);
+
+	return 0;
+}
+
+static int k230_usb_phy_power_off(struct phy *phy)
+{
+	struct k230_usb_phy_instance *inst = phy_get_drvdata(phy);
+	struct k230_usb_phy_global *global = inst->global;
+	void __iomem *base = global->base;
+	u32 val;
+
+	val = readl(base + inst->test_offset + TEST_CTL3_OFFSET);
+	val &= ~(USB_DMPULLDOWN0 | USB_DPPULLDOWN0);
+	writel(val, base + inst->test_offset + TEST_CTL3_OFFSET);
+
+	return 0;
+}
+
+static const struct phy_ops k230_usb_phy_ops = {
+	.power_on = k230_usb_phy_power_on,
+	.power_off = k230_usb_phy_power_off,
+	.owner = THIS_MODULE,
+};
+
+static struct phy *k230_usb_phy_xlate(struct device *dev,
+				      const struct of_phandle_args *args)
+{
+	struct k230_usb_phy_global *global = dev_get_drvdata(dev);
+	unsigned int idx = args->args[0];
+
+	if (idx >= MAX_PHYS)
+		return ERR_PTR(-EINVAL);
+
+	return global->phys[idx].phy;
+}
+
+static int k230_usb_phy_probe(struct platform_device *pdev)
+{
+	struct k230_usb_phy_global *global;
+	struct device *dev = &pdev->dev;
+	struct phy_provider *provider;
+	int i;
+
+	global = devm_kzalloc(dev, sizeof(*global), GFP_KERNEL);
+	if (!global)
+		return -ENOMEM;
+	dev_set_drvdata(dev, global);
+
+	global->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(global->base))
+		return dev_err_probe(dev, PTR_ERR(global->base),
+				     "failed to map registers\n");
+
+	static const struct {
+		u32 test_offset;
+		u32 ctl_offset;
+	} phy_reg_info[MAX_PHYS] = {
+		[0] = { K230_USB0_TEST_REG_BASE, K230_USB0_CTL_REG_BASE },
+		[1] = { K230_USB1_TEST_REG_BASE, K230_USB1_CTL_REG_BASE },
+	};
+
+	for (i = 0; i < MAX_PHYS; i++) {
+		struct k230_usb_phy_instance *inst = &global->phys[i];
+		struct phy *phy;
+
+		inst->global = global;
+		inst->index = i;
+		inst->test_offset = phy_reg_info[i].test_offset;
+		inst->ctl_offset  = phy_reg_info[i].ctl_offset;
+
+		phy = devm_phy_create(dev, NULL, &k230_usb_phy_ops);
+		if (IS_ERR(phy)) {
+			dev_err(dev, "failed to create phy%d\n", i);
+			return PTR_ERR(phy);
+		}
+
+		phy_set_drvdata(phy, inst);
+		inst->phy = phy;
+	}
+
+	provider = devm_of_phy_provider_register(dev, k230_usb_phy_xlate);
+	if (IS_ERR(provider))
+		return PTR_ERR(provider);
+
+	return 0;
+}
+
+static const struct of_device_id k230_usb_phy_of_match[] = {
+	{ .compatible = "canaan,k230-usb-phy" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, k230_usb_phy_of_match);
+
+static struct platform_driver k230_usb_phy_driver = {
+	.probe = k230_usb_phy_probe,
+	.driver = {
+		.name = "k230-usb-phy",
+		.of_match_table = k230_usb_phy_of_match,
+	},
+};
+module_platform_driver(k230_usb_phy_driver);
+
+MODULE_DESCRIPTION("Canaan Kendryte K230 USB 2.0 PHY driver");
+MODULE_AUTHOR("Jiayu Du <jiayu.riscv@isrc.iscas.ac.cn>");
+MODULE_LICENSE("GPL");