[PATCH v6 3/7] phy: starfive: Add JH7110 USB 2.0 PHY driver

[Minda Chen <minda.chen@starfivetech.com>]

Add Starfive JH7110 SoC USB 2.0 PHY driver support.
USB 2.0 PHY default connect to Cadence USB controller.

Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
---
 MAINTAINERS                           |   6 ++
 drivers/phy/starfive/Kconfig          |  11 ++
 drivers/phy/starfive/Makefile         |   1 +
 drivers/phy/starfive/phy-jh7110-usb.c | 150 ++++++++++++++++++++++++++
 4 files changed, 168 insertions(+)
 create mode 100644 drivers/phy/starfive/phy-jh7110-usb.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 0606ed87cf1c..b900f661c2e0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20160,6 +20160,12 @@ S:	Supported
 F:	Documentation/devicetree/bindings/watchdog/starfive*
 F:	drivers/watchdog/starfive-wdt.c
 
+STARFIVE JH71X0 USB PHY DRIVER
+M:	Minda Chen <minda.chen@starfivetech.com>
+S:	Supported
+F:	Documentation/devicetree/bindings/phy/starfive,jh7110-usb-phy.yaml
+F:	drivers/phy/starfive/phy-jh7110-usb.c
+
 STATIC BRANCH/CALL
 M:	Peter Zijlstra <peterz@infradead.org>
 M:	Josh Poimboeuf <jpoimboe@kernel.org>
diff --git a/drivers/phy/starfive/Kconfig b/drivers/phy/starfive/Kconfig
index f989b8ff8bcb..2c013c390dee 100644
--- a/drivers/phy/starfive/Kconfig
+++ b/drivers/phy/starfive/Kconfig
@@ -11,3 +11,14 @@ config PHY_STARFIVE_DPHY_RX
 	  Choose this option if you have a StarFive D-PHY in your
 	  system. If M is selected, the module will be called
 	  phy-starfive-dphy-rx.
+
+config PHY_STARFIVE_JH7110_USB
+	tristate "Starfive JH7110 USB 2.0 PHY support"
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	select USB_PHY
+	help
+	  Enable this to support the StarFive USB 2.0 PHY,
+	  used with the Cadence USB controller.
+	  If M is selected, the module will be called
+	  phy-jh7110-usb.ko.
diff --git a/drivers/phy/starfive/Makefile b/drivers/phy/starfive/Makefile
index 7ec576cb30ae..176443852f4d 100644
--- a/drivers/phy/starfive/Makefile
+++ b/drivers/phy/starfive/Makefile
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_PHY_STARFIVE_DPHY_RX)      += phy-starfive-dphy-rx.o
+obj-$(CONFIG_PHY_STARFIVE_JH7110_USB)	+= phy-jh7110-usb.o
diff --git a/drivers/phy/starfive/phy-jh7110-usb.c b/drivers/phy/starfive/phy-jh7110-usb.c
new file mode 100644
index 000000000000..90d788423705
--- /dev/null
+++ b/drivers/phy/starfive/phy-jh7110-usb.c
@@ -0,0 +1,150 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * StarFive JH7110 USB 2.0 PHY driver
+ *
+ * Copyright (C) 2023 StarFive Technology Co., Ltd.
+ * Author: Minda Chen <minda.chen@starfivetech.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/usb/of.h>
+
+#define USB_125M_CLK_RATE		125000000
+#define USB_LS_KEEPALIVE_OFF		0x4
+#define USB_LS_KEEPALIVE_ENABLE		BIT(4)
+
+struct jh7110_usb2_phy {
+	struct phy *phy;
+	void __iomem *regs;
+	struct clk *usb_125m_clk;
+	struct clk *app_125m;
+	enum phy_mode mode;
+};
+
+static void jh7110_usb2_mode_set(struct jh7110_usb2_phy *phy)
+{
+	unsigned int val;
+
+	if (phy->mode != PHY_MODE_USB_HOST) {
+		/* Enable the LS speed keep-alive signal */
+		val = readl(phy->regs + USB_LS_KEEPALIVE_OFF);
+		val |= USB_LS_KEEPALIVE_ENABLE;
+		writel(val, phy->regs + USB_LS_KEEPALIVE_OFF);
+	}
+}
+
+static int jh7110_usb2_phy_set_mode(struct phy *_phy,
+				    enum phy_mode mode, int submode)
+{
+	struct jh7110_usb2_phy *phy = phy_get_drvdata(_phy);
+
+	switch (mode) {
+	case PHY_MODE_USB_HOST:
+	case PHY_MODE_USB_DEVICE:
+	case PHY_MODE_USB_OTG:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (mode != phy->mode) {
+		dev_dbg(&_phy->dev, "Changing phy to %d\n", mode);
+		phy->mode = mode;
+		jh7110_usb2_mode_set(phy);
+	}
+
+	return 0;
+}
+
+static int jh7110_usb2_phy_init(struct phy *_phy)
+{
+	struct jh7110_usb2_phy *phy = phy_get_drvdata(_phy);
+	int ret;
+
+	ret = clk_set_rate(phy->usb_125m_clk, USB_125M_CLK_RATE);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(phy->app_125m);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int jh7110_usb2_phy_exit(struct phy *_phy)
+{
+	struct jh7110_usb2_phy *phy = phy_get_drvdata(_phy);
+
+	clk_disable_unprepare(phy->app_125m);
+
+	return 0;
+}
+
+static const struct phy_ops jh7110_usb2_phy_ops = {
+	.init		= jh7110_usb2_phy_init,
+	.exit		= jh7110_usb2_phy_exit,
+	.set_mode	= jh7110_usb2_phy_set_mode,
+	.owner		= THIS_MODULE,
+};
+
+static int jh7110_usb_phy_probe(struct platform_device *pdev)
+{
+	struct jh7110_usb2_phy *phy;
+	struct device *dev = &pdev->dev;
+	struct phy_provider *phy_provider;
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->usb_125m_clk = devm_clk_get(dev, "125m");
+	if (IS_ERR(phy->usb_125m_clk))
+		return dev_err_probe(dev, PTR_ERR(phy->usb_125m_clk),
+			"Failed to get 125m clock\n");
+
+	phy->app_125m = devm_clk_get(dev, "app_125m");
+	if (IS_ERR(phy->app_125m))
+		return dev_err_probe(dev, PTR_ERR(phy->app_125m),
+			"Failed to get app 125m clock\n");
+
+	phy->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(phy->regs))
+		return dev_err_probe(dev, PTR_ERR(phy->regs),
+			"Failed to map phy base\n");
+
+	phy->phy = devm_phy_create(dev, NULL, &jh7110_usb2_phy_ops);
+	if (IS_ERR(phy->phy))
+		return dev_err_probe(dev, PTR_ERR(phy->phy),
+			"Failed to create phy\n");
+
+	phy_set_drvdata(phy->phy, 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 jh7110_usb_phy_of_match[] = {
+	{ .compatible = "starfive,jh7110-usb-phy" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, jh7110_usb_phy_of_match);
+
+static struct platform_driver jh7110_usb_phy_driver = {
+	.probe	= jh7110_usb_phy_probe,
+	.driver = {
+		.of_match_table	= jh7110_usb_phy_of_match,
+		.name  = "jh7110-usb-phy",
+	}
+};
+module_platform_driver(jh7110_usb_phy_driver);
+
+MODULE_DESCRIPTION("StarFive JH7110 USB 2.0 PHY driver");
+MODULE_AUTHOR("Minda Chen <minda.chen@starfivetech.com>");
+MODULE_LICENSE("GPL");
-- 
2.17.1