phy: add A3700 UTMI PHY driver

Marvell Armada 3700 SoC has two USB controllers, each of them being
wired to an internal UTMI PHY. Add a driver to control them.

Igal Liberman worked on supporting the PHY, I took the while 'register
configuration' from his work and rewrote almost entirely the
driver/bindings around it.

Co-developed-by: Igal Liberman <[e-mail]>
Signed-off-by: Miquel Raynal <[e-mail]>
Signed-off-by: Igal Liberman <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

drivers/phy/marvell/Kconfig

···
 	  shared serdes PHYs on Marvell Armada 3700. Its serdes lanes can be
 	  used by various controllers: Ethernet, SATA, USB3, PCIe.
 
+config PHY_MVEBU_A3700_UTMI
+	tristate "Marvell A3700 UTMI driver"
+	depends on ARCH_MVEBU || COMPILE_TEST
+	depends on OF
+	default y
+	select GENERIC_PHY
+	help
+	  Enable this to support Marvell A3700 UTMI PHY driver.
+
 config PHY_MVEBU_CP110_COMPHY
 	tristate "Marvell CP110 comphy driver"
 	depends on ARCH_MVEBU || COMPILE_TEST

drivers/phy/marvell/Makefile

···
 obj-$(CONFIG_PHY_BERLIN_SATA)		+= phy-berlin-sata.o
 obj-$(CONFIG_PHY_BERLIN_USB)		+= phy-berlin-usb.o
 obj-$(CONFIG_PHY_MVEBU_A3700_COMPHY)	+= phy-mvebu-a3700-comphy.o
+obj-$(CONFIG_PHY_MVEBU_A3700_UTMI)	+= phy-mvebu-a3700-utmi.o
 obj-$(CONFIG_PHY_MVEBU_CP110_COMPHY)	+= phy-mvebu-cp110-comphy.o
 obj-$(CONFIG_PHY_MVEBU_SATA)		+= phy-mvebu-sata.o
 obj-$(CONFIG_PHY_PXA_28NM_HSIC)		+= phy-pxa-28nm-hsic.o

drivers/phy/marvell/phy-mvebu-a3700-utmi.c

···
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Marvell
+ *
+ * Authors:
+ *   Igal Liberman <[e-mail]>
+ *   Miquèl Raynal <[e-mail]>
+ *
+ * Marvell A3700 UTMI PHY driver
+ */
+
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* Armada 3700 UTMI PHY registers */
+#define USB2_PHY_PLL_CTRL_REG0			0x0
+#define   PLL_REF_DIV_OFF			0
+#define   PLL_REF_DIV_MASK			GENMASK(6, 0)
+#define   PLL_REF_DIV_5				5
+#define   PLL_FB_DIV_OFF			16
+#define   PLL_FB_DIV_MASK			GENMASK(24, 16)
+#define   PLL_FB_DIV_96				96
+#define   PLL_SEL_LPFR_OFF			28
+#define   PLL_SEL_LPFR_MASK			GENMASK(29, 28)
+#define   PLL_READY				BIT(31)
+#define USB2_PHY_CAL_CTRL			0x8
+#define   PHY_PLLCAL_DONE			BIT(31)
+#define   PHY_IMPCAL_DONE			BIT(23)
+#define USB2_RX_CHAN_CTRL1			0x18
+#define   USB2PHY_SQCAL_DONE			BIT(31)
+#define USB2_PHY_OTG_CTRL			0x34
+#define   PHY_PU_OTG				BIT(4)
+#define USB2_PHY_CHRGR_DETECT			0x38
+#define   PHY_CDP_EN				BIT(2)
+#define   PHY_DCP_EN				BIT(3)
+#define   PHY_PD_EN				BIT(4)
+#define   PHY_PU_CHRG_DTC			BIT(5)
+#define   PHY_CDP_DM_AUTO			BIT(7)
+#define   PHY_ENSWITCH_DP			BIT(12)
+#define   PHY_ENSWITCH_DM			BIT(13)
+
+/* Armada 3700 USB miscellaneous registers */
+#define USB2_PHY_CTRL(usb32)			(usb32 ? 0x20 : 0x4)
+#define   RB_USB2PHY_PU				BIT(0)
+#define   USB2_DP_PULLDN_DEV_MODE		BIT(5)
+#define   USB2_DM_PULLDN_DEV_MODE		BIT(6)
+#define   RB_USB2PHY_SUSPM(usb32)		(usb32 ? BIT(14) : BIT(7))
+
+#define PLL_LOCK_DELAY_US			10000
+#define PLL_LOCK_TIMEOUT_US			1000000
+
+/**
+ * struct mvebu_a3700_utmi_caps - PHY capabilities
+ *
+ * @usb32: Flag indicating which PHY is in use (impacts the register map):
+ *           - The UTMI PHY wired to the USB3/USB2 controller (otg)
+ *           - The UTMI PHY wired to the USB2 controller (host only)
+ * @ops: PHY operations
+ */
+struct mvebu_a3700_utmi_caps {
+	int usb32;
+	const struct phy_ops *ops;
+};
+
+/**
+ * struct mvebu_a3700_utmi - PHY driver data
+ *
+ * @regs: PHY registers
+ * @usb_mis: Regmap with USB miscellaneous registers including PHY ones
+ * @caps: PHY capabilities
+ * @phy: PHY handle
+ */
+struct mvebu_a3700_utmi {
+	void __iomem *regs;
+	struct regmap *usb_misc;
+	const struct mvebu_a3700_utmi_caps *caps;
+	struct phy *phy;
+};
+
+static int mvebu_a3700_utmi_phy_power_on(struct phy *phy)
+{
+	struct mvebu_a3700_utmi *utmi = phy_get_drvdata(phy);
+	struct device *dev = &phy->dev;
+	int usb32 = utmi->caps->usb32;
+	int ret = 0;
+	u32 reg;
+
+	/*
+	 * Setup PLL. 40MHz clock used to be the default, being 25MHz now.
+	 * See "PLL Settings for Typical REFCLK" table.
+	 */
+	reg = readl(utmi->regs + USB2_PHY_PLL_CTRL_REG0);
+	reg &= ~(PLL_REF_DIV_MASK | PLL_FB_DIV_MASK | PLL_SEL_LPFR_MASK);
+	reg |= (PLL_REF_DIV_5 << PLL_REF_DIV_OFF) |
+	       (PLL_FB_DIV_96 << PLL_FB_DIV_OFF);
+	writel(reg, utmi->regs + USB2_PHY_PLL_CTRL_REG0);
+
+	/* Enable PHY pull up and disable USB2 suspend */
+	regmap_update_bits(utmi->usb_misc, USB2_PHY_CTRL(usb32),
+			   RB_USB2PHY_SUSPM(usb32) | RB_USB2PHY_PU,
+			   RB_USB2PHY_SUSPM(usb32) | RB_USB2PHY_PU);
+
+	if (usb32) {
+		/* Power up OTG module */
+		reg = readl(utmi->regs + USB2_PHY_OTG_CTRL);
+		reg |= PHY_PU_OTG;
+		writel(reg, utmi->regs + USB2_PHY_OTG_CTRL);
+
+		/* Disable PHY charger detection */
+		reg = readl(utmi->regs + USB2_PHY_CHRGR_DETECT);
+		reg &= ~(PHY_CDP_EN | PHY_DCP_EN | PHY_PD_EN | PHY_PU_CHRG_DTC |
+			 PHY_CDP_DM_AUTO | PHY_ENSWITCH_DP | PHY_ENSWITCH_DM);
+		writel(reg, utmi->regs + USB2_PHY_CHRGR_DETECT);
+
+		/* Disable PHY DP/DM pull-down (used for device mode) */
+		regmap_update_bits(utmi->usb_misc, USB2_PHY_CTRL(usb32),
+				   USB2_DP_PULLDN_DEV_MODE |
+				   USB2_DM_PULLDN_DEV_MODE, 0);
+	}
+
+	/* Wait for PLL calibration */
+	ret = readl_poll_timeout(utmi->regs + USB2_PHY_CAL_CTRL, reg,
+				 reg & PHY_PLLCAL_DONE,
+				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
+	if (ret) {
+		dev_err(dev, "Failed to end USB2 PLL calibration\n");
+		return ret;
+	}
+
+	/* Wait for impedance calibration */
+	ret = readl_poll_timeout(utmi->regs + USB2_PHY_CAL_CTRL, reg,
+				 reg & PHY_IMPCAL_DONE,
+				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
+	if (ret) {
+		dev_err(dev, "Failed to end USB2 impedance calibration\n");
+		return ret;
+	}
+
+	/* Wait for squelch calibration */
+	ret = readl_poll_timeout(utmi->regs + USB2_RX_CHAN_CTRL1, reg,
+				 reg & USB2PHY_SQCAL_DONE,
+				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
+	if (ret) {
+		dev_err(dev, "Failed to end USB2 unknown calibration\n");
+		return ret;
+	}
+
+	/* Wait for PLL to be locked */
+	ret = readl_poll_timeout(utmi->regs + USB2_PHY_PLL_CTRL_REG0, reg,
+				 reg & PLL_READY,
+				 PLL_LOCK_DELAY_US, PLL_LOCK_TIMEOUT_US);
+	if (ret)
+		dev_err(dev, "Failed to lock USB2 PLL\n");
+
+	return ret;
+}
+
+static int mvebu_a3700_utmi_phy_power_off(struct phy *phy)
+{
+	struct mvebu_a3700_utmi *utmi = phy_get_drvdata(phy);
+	int usb32 = utmi->caps->usb32;
+	u32 reg;
+
+	/* Disable PHY pull-up and enable USB2 suspend */
+	reg = readl(utmi->regs + USB2_PHY_CTRL(usb32));
+	reg &= ~(RB_USB2PHY_PU | RB_USB2PHY_SUSPM(usb32));
+	writel(reg, utmi->regs + USB2_PHY_CTRL(usb32));
+
+	/* Power down OTG module */
+	if (usb32) {
+		reg = readl(utmi->regs + USB2_PHY_OTG_CTRL);
+		reg &= ~PHY_PU_OTG;
+		writel(reg, utmi->regs + USB2_PHY_OTG_CTRL);
+	}
+
+	return 0;
+}
+
+static const struct phy_ops mvebu_a3700_utmi_phy_ops = {
+	.power_on = mvebu_a3700_utmi_phy_power_on,
+	.power_off = mvebu_a3700_utmi_phy_power_off,
+	.owner = THIS_MODULE,
+};
+
+static const struct mvebu_a3700_utmi_caps mvebu_a3700_utmi_otg_phy_caps = {
+	.usb32 = true,
+	.ops = &mvebu_a3700_utmi_phy_ops,
+};
+
+static const struct mvebu_a3700_utmi_caps mvebu_a3700_utmi_host_phy_caps = {
+	.usb32 = false,
+	.ops = &mvebu_a3700_utmi_phy_ops,
+};
+
+static const struct of_device_id mvebu_a3700_utmi_of_match[] = {
+	{
+		.compatible = "marvell,a3700-utmi-otg-phy",
+		.data = &mvebu_a3700_utmi_otg_phy_caps,
+	},
+	{
+		.compatible = "marvell,a3700-utmi-host-phy",
+		.data = &mvebu_a3700_utmi_host_phy_caps,
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, mvebu_a3700_utmi_of_match);
+
+static int mvebu_a3700_utmi_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mvebu_a3700_utmi *utmi;
+	struct phy_provider *provider;
+	struct resource *res;
+
+	utmi = devm_kzalloc(dev, sizeof(*utmi), GFP_KERNEL);
+	if (!utmi)
+		return -ENOMEM;
+
+	/* Get UTMI memory region */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(dev, "Missing UTMI PHY memory resource\n");
+		return -ENODEV;
+	}
+
+	utmi->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(utmi->regs))
+		return PTR_ERR(utmi->regs);
+
+	/* Get miscellaneous Host/PHY region */
+	utmi->usb_misc = syscon_regmap_lookup_by_phandle(dev->of_node,
+							 "marvell,usb-misc-reg");
+	if (IS_ERR(utmi->usb_misc)) {
+		dev_err(dev,
+			"Missing USB misc purpose system controller\n");
+		return PTR_ERR(utmi->usb_misc);
+	}
+
+	/* Retrieve PHY capabilities */
+	utmi->caps = of_device_get_match_data(dev);
+
+	/* Instantiate the PHY */
+	utmi->phy = devm_phy_create(dev, NULL, utmi->caps->ops);
+	if (IS_ERR(utmi->phy)) {
+		dev_err(dev, "Failed to create the UTMI PHY\n");
+		return PTR_ERR(utmi->phy);
+	}
+
+	phy_set_drvdata(utmi->phy, utmi);
+
+	/* Ensure the PHY is powered off */
+	utmi->caps->ops->power_off(utmi->phy);
+
+	provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(provider);
+}
+
+static struct platform_driver mvebu_a3700_utmi_driver = {
+	.probe	= mvebu_a3700_utmi_phy_probe,
+	.driver	= {
+		.name		= "mvebu-a3700-utmi-phy",
+		.owner		= THIS_MODULE,
+		.of_match_table	= mvebu_a3700_utmi_of_match,
+	 },
+};
+module_platform_driver(mvebu_a3700_utmi_driver);
+
+MODULE_AUTHOR("Igal Liberman <[e-mail]>");
+MODULE_AUTHOR("Miquel Raynal <[e-mail]>");
+MODULE_DESCRIPTION("Marvell EBU A3700 UTMI PHY driver");
+MODULE_LICENSE("GPL v2");