phy: starfive: Add JH7110 PCIE 2.0 PHY driver

Add Starfive JH7110 SoC PCIe 2.0 PHY driver support.
PCIe 2.0 PHY default connect to PCIe controller.
PCIe PHY can connect to USB 3.0 controller.

Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Reviewed-by: Roger Quadros <rogerq@kernel.org>
Link: https://lore.kernel.org/r/20230629075115.11934-5-minda.chen@starfivetech.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

3 files changed, 215 insertions, 0 deletions

diff --git a/drivers/phy/starfive/Kconfig b/drivers/phy/starfive/Kconfig
index 65b5f879bbf9..da9a98cdf7e3 100644
--- a/drivers/phy/starfive/Kconfig
+++ b/drivers/phy/starfive/Kconfig
@@ -3,6 +3,16 @@
 # Phy drivers for StarFive platforms
 #
 
+config PHY_STARFIVE_JH7110_PCIE
+	tristate "Starfive JH7110 PCIE 2.0/USB 3.0 PHY support"
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support the StarFive PCIe 2.0 PHY,
+	  or used as USB 3.0 PHY.
+	  If M is selected, the module will be called
+	  phy-jh7110-pcie.ko.
+
 config PHY_STARFIVE_JH7110_USB
 	tristate "Starfive JH7110 USB 2.0 PHY support"
 	depends on USB_SUPPORT
diff --git a/drivers/phy/starfive/Makefile b/drivers/phy/starfive/Makefile
index 52e9a09cc619..1c62d93e3280 100644
--- a/drivers/phy/starfive/Makefile
+++ b/drivers/phy/starfive/Makefile
@@ -1,2 +1,3 @@
 # SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_PHY_STARFIVE_JH7110_PCIE)	+= phy-jh7110-pcie.o
 obj-$(CONFIG_PHY_STARFIVE_JH7110_USB)	+= phy-jh7110-usb.o
diff --git a/drivers/phy/starfive/phy-jh7110-pcie.c b/drivers/phy/starfive/phy-jh7110-pcie.c
new file mode 100644
index 000000000000..cbe79c1f59d3
--- /dev/null
+++ b/drivers/phy/starfive/phy-jh7110-pcie.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * StarFive JH7110 PCIe 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/mfd/syscon.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define PCIE_KVCO_LEVEL_OFF		0x28
+#define PCIE_USB3_PHY_PLL_CTL_OFF	0x7c
+#define PCIE_KVCO_TUNE_SIGNAL_OFF	0x80
+#define PCIE_USB3_PHY_ENABLE		BIT(4)
+#define PHY_KVCO_FINE_TUNE_LEVEL	0x91
+#define PHY_KVCO_FINE_TUNE_SIGNALS	0xc
+
+#define USB_PDRSTN_SPLIT		BIT(17)
+
+#define PCIE_PHY_MODE			BIT(20)
+#define PCIE_PHY_MODE_MASK		GENMASK(21, 20)
+#define PCIE_USB3_BUS_WIDTH_MASK	GENMASK(3, 2)
+#define PCIE_USB3_BUS_WIDTH		BIT(3)
+#define PCIE_USB3_RATE_MASK		GENMASK(6, 5)
+#define PCIE_USB3_RX_STANDBY_MASK	BIT(7)
+#define PCIE_USB3_PHY_ENABLE		BIT(4)
+
+struct jh7110_pcie_phy {
+	struct phy *phy;
+	struct regmap *stg_syscon;
+	struct regmap *sys_syscon;
+	void __iomem *regs;
+	u32 sys_phy_connect;
+	u32 stg_pcie_mode;
+	u32 stg_pcie_usb;
+	enum phy_mode mode;
+};
+
+static int phy_usb3_mode_set(struct jh7110_pcie_phy *data)
+{
+	if (!data->stg_syscon || !data->sys_syscon) {
+		dev_err(&data->phy->dev, "doesn't support usb3 mode\n");
+		return -EINVAL;
+	}
+
+	regmap_update_bits(data->stg_syscon, data->stg_pcie_mode,
+			   PCIE_PHY_MODE_MASK, PCIE_PHY_MODE);
+	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
+			   PCIE_USB3_BUS_WIDTH_MASK, 0);
+	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
+			   PCIE_USB3_PHY_ENABLE, PCIE_USB3_PHY_ENABLE);
+
+	/* Connect usb 3.0 phy mode */
+	regmap_update_bits(data->sys_syscon, data->sys_phy_connect,
+			   USB_PDRSTN_SPLIT, 0);
+
+	/* Configuare spread-spectrum mode: down-spread-spectrum */
+	writel(PCIE_USB3_PHY_ENABLE, data->regs + PCIE_USB3_PHY_PLL_CTL_OFF);
+
+	return 0;
+}
+
+static void phy_pcie_mode_set(struct jh7110_pcie_phy *data)
+{
+	u32 val;
+
+	/* default is PCIe mode */
+	if (!data->stg_syscon || !data->sys_syscon)
+		return;
+
+	regmap_update_bits(data->stg_syscon, data->stg_pcie_mode,
+			   PCIE_PHY_MODE_MASK, 0);
+	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
+			   PCIE_USB3_BUS_WIDTH_MASK,
+			   PCIE_USB3_BUS_WIDTH);
+	regmap_update_bits(data->stg_syscon, data->stg_pcie_usb,
+			   PCIE_USB3_PHY_ENABLE, 0);
+
+	regmap_update_bits(data->sys_syscon, data->sys_phy_connect,
+			   USB_PDRSTN_SPLIT, 0);
+
+	val = readl(data->regs + PCIE_USB3_PHY_PLL_CTL_OFF);
+	val &= ~PCIE_USB3_PHY_ENABLE;
+	writel(val, data->regs + PCIE_USB3_PHY_PLL_CTL_OFF);
+}
+
+static void phy_kvco_gain_set(struct jh7110_pcie_phy *phy)
+{
+	/* PCIe Multi-PHY PLL KVCO Gain fine tune settings: */
+	writel(PHY_KVCO_FINE_TUNE_LEVEL, phy->regs + PCIE_KVCO_LEVEL_OFF);
+	writel(PHY_KVCO_FINE_TUNE_SIGNALS, phy->regs + PCIE_KVCO_TUNE_SIGNAL_OFF);
+}
+
+static int jh7110_pcie_phy_set_mode(struct phy *_phy,
+				    enum phy_mode mode, int submode)
+{
+	struct jh7110_pcie_phy *phy = phy_get_drvdata(_phy);
+	int ret;
+
+	if (mode == phy->mode)
+		return 0;
+
+	switch (mode) {
+	case PHY_MODE_USB_HOST:
+	case PHY_MODE_USB_DEVICE:
+	case PHY_MODE_USB_OTG:
+		ret = phy_usb3_mode_set(phy);
+		if (ret)
+			return ret;
+		break;
+	case PHY_MODE_PCIE:
+		phy_pcie_mode_set(phy);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	dev_dbg(&_phy->dev, "Changing phy mode to %d\n", mode);
+	phy->mode = mode;
+
+	return 0;
+}
+
+static const struct phy_ops jh7110_pcie_phy_ops = {
+	.set_mode	= jh7110_pcie_phy_set_mode,
+	.owner		= THIS_MODULE,
+};
+
+static int jh7110_pcie_phy_probe(struct platform_device *pdev)
+{
+	struct jh7110_pcie_phy *phy;
+	struct device *dev = &pdev->dev;
+	struct phy_provider *phy_provider;
+	u32 args[2];
+
+	phy = devm_kzalloc(dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	phy->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(phy->regs))
+		return PTR_ERR(phy->regs);
+
+	phy->phy = devm_phy_create(dev, NULL, &jh7110_pcie_phy_ops);
+	if (IS_ERR(phy->phy))
+		return dev_err_probe(dev, PTR_ERR(phy->regs),
+				     "Failed to map phy base\n");
+
+	phy->sys_syscon =
+		syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
+						     "starfive,sys-syscon",
+						     1, args);
+
+	if (!IS_ERR_OR_NULL(phy->sys_syscon))
+		phy->sys_phy_connect = args[0];
+	else
+		phy->sys_syscon = NULL;
+
+	phy->stg_syscon =
+		syscon_regmap_lookup_by_phandle_args(pdev->dev.of_node,
+						     "starfive,stg-syscon",
+						     2, args);
+
+	if (!IS_ERR_OR_NULL(phy->stg_syscon)) {
+		phy->stg_pcie_mode = args[0];
+		phy->stg_pcie_usb = args[1];
+	} else {
+		phy->stg_syscon = NULL;
+	}
+
+	phy_kvco_gain_set(phy);
+
+	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_pcie_phy_of_match[] = {
+	{ .compatible = "starfive,jh7110-pcie-phy" },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, jh7110_pcie_phy_of_match);
+
+static struct platform_driver jh7110_pcie_phy_driver = {
+	.probe	= jh7110_pcie_phy_probe,
+	.driver = {
+		.of_match_table	= jh7110_pcie_phy_of_match,
+		.name  = "jh7110-pcie-phy",
+	}
+};
+module_platform_driver(jh7110_pcie_phy_driver);
+
+MODULE_DESCRIPTION("StarFive JH7110 PCIe 2.0 PHY driver");
+MODULE_AUTHOR("Minda Chen <minda.chen@starfivetech.com>");
+MODULE_LICENSE("GPL");