[Patch v7 2/3] usb: phy: Add Qualcomm DWC3 HS/SS PHY drivers

Andy Gross agross at codeaurora.org
Mon Jun 30 09:03:52 PDT 2014


From: "Ivan T. Ivanov" <iivanov at mm-sol.com>

These drivers handles control and configuration of the HS
and SS USB PHY transceivers. They are part of the driver
which manage Synopsys DesignWare USB3 controller stack
inside Qualcomm SoC's.

Signed-off-by: Ivan T. Ivanov <iivanov at mm-sol.com>
Signed-off-by: Andy Gross <agross at codeaurora.org>
---
 drivers/usb/phy/Kconfig          |   11 ++
 drivers/usb/phy/Makefile         |    2 +
 drivers/usb/phy/phy-qcom-hsusb.c |  348 ++++++++++++++++++++++++++++++++++
 drivers/usb/phy/phy-qcom-ssusb.c |  385 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 746 insertions(+)
 create mode 100644 drivers/usb/phy/phy-qcom-hsusb.c
 create mode 100644 drivers/usb/phy/phy-qcom-ssusb.c

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index e253fa0..5580c2f 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -229,4 +229,15 @@ config USB_ULPI_VIEWPORT
 	  Provides read/write operations to the ULPI phy register set for
 	  controllers with a viewport register (e.g. Chipidea/ARC controllers).
 
+config USB_QCOM_DWC3_PHY
+	tristate "Qualcomm USB controller DWC3 PHY wrappers support"
+	depends on (USB || USB_GADGET) && ARCH_QCOM
+	select USB_PHY
+	help
+	  Enable this to support the DWC3 USB PHY transceivers on QCOM chips
+	  with DWC3 USB core. It handles PHY initialization, clock
+	  management required after resetting the hardware and power
+	  management. This driver is required even for peripheral only or
+	  host only mode configurations.
+
 endmenu
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index 24a9133..ef09c9c 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -29,3 +29,5 @@ obj-$(CONFIG_USB_RCAR_GEN2_PHY)		+= phy-rcar-gen2-usb.o
 obj-$(CONFIG_USB_ULPI)			+= phy-ulpi.o
 obj-$(CONFIG_USB_ULPI_VIEWPORT)		+= phy-ulpi-viewport.o
 obj-$(CONFIG_KEYSTONE_USB_PHY)		+= phy-keystone.o
+obj-$(CONFIG_USB_QCOM_DWC3_PHY)		+= phy-qcom-hsusb.o
+obj-$(CONFIG_USB_QCOM_DWC3_PHY)		+= phy-qcom-ssusb.o
diff --git a/drivers/usb/phy/phy-qcom-hsusb.c b/drivers/usb/phy/phy-qcom-hsusb.c
new file mode 100644
index 0000000..7a44b13
--- /dev/null
+++ b/drivers/usb/phy/phy-qcom-hsusb.c
@@ -0,0 +1,348 @@
+/* Copyright (c) 2013-2014, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb/phy.h>
+
+/**
+ *  USB QSCRATCH Hardware registers
+ */
+#define QSCRATCH_CTRL_REG		(0x04)
+#define QSCRATCH_GENERAL_CFG		(0x08)
+#define PHY_CTRL_REG			(0x10)
+#define PARAMETER_OVERRIDE_X_REG	(0x14)
+#define CHARGING_DET_CTRL_REG		(0x18)
+#define CHARGING_DET_OUTPUT_REG		(0x1c)
+#define ALT_INTERRUPT_EN_REG		(0x20)
+#define PHY_IRQ_STAT_REG		(0x24)
+#define CGCTL_REG			(0x28)
+
+#define PHY_3P3_VOL_MIN			3050000 /* uV */
+#define PHY_3P3_VOL_MAX			3300000 /* uV */
+#define PHY_3P3_HPM_LOAD		16000	/* uA */
+
+#define PHY_1P8_VOL_MIN			1800000 /* uV */
+#define PHY_1P8_VOL_MAX			1800000 /* uV */
+#define PHY_1P8_HPM_LOAD		19000	/* uA */
+
+/* TODO: these are suspicious */
+#define USB_VDDCX_NO			1	/* index */
+#define USB_VDDCX_MIN			5	/* index */
+#define USB_VDDCX_MAX			7	/* index */
+
+/* PHY_CTRL_REG */
+#define HSUSB_CTRL_DMSEHV_CLAMP			BIT(24)
+#define HSUSB_CTRL_USB2_SUSPEND			BIT(23)
+#define HSUSB_CTRL_UTMI_CLK_EN			BIT(21)
+#define	HSUSB_CTRL_UTMI_OTG_VBUS_VALID		BIT(20)
+#define HSUSB_CTRL_USE_CLKCORE			BIT(18)
+#define HSUSB_CTRL_DPSEHV_CLAMP			BIT(17)
+#define HSUSB_CTRL_COMMONONN			BIT(11)
+#define HSUSB_CTRL_ID_HV_CLAMP			BIT(9)
+#define HSUSB_CTRL_OTGSESSVLD_CLAMP		BIT(8)
+#define HSUSB_CTRL_CLAMP_EN			BIT(7)
+#define HSUSB_CTRL_RETENABLEN			BIT(1)
+#define HSYSB_CTRL_POR				BIT(0)
+
+
+/* QSCRATCH_GENERAL_CFG */
+#define HSUSB_GCFG_XHCI_REV		BIT(2)
+
+struct qcom_dwc3_hs_phy {
+	struct usb_phy		phy;
+	void __iomem		*base;
+	struct device		*dev;
+
+	struct clk		*xo_clk;
+	struct clk		*utmi_clk;
+
+	struct regulator	*v3p3;
+	struct regulator	*v1p8;
+	struct regulator	*vddcx;
+	struct regulator	*vbus;
+};
+
+#define	phy_to_dw_phy(x)	container_of((x), struct qcom_dwc3_hs_phy, phy)
+
+/**
+ * Write register.
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @offset - register offset.
+ * @val - value to write.
+ */
+static inline void qcom_dwc3_hs_write(void __iomem *base, u32 offset, u32 val)
+{
+	writel(val, base + offset);
+}
+
+/**
+ * Write register and read back masked value to confirm it is written
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @offset - register offset.
+ * @mask - register bitmask specifying what should be updated
+ * @val - value to write.
+ */
+static inline void qcom_dwc3_hs_write_readback(void __iomem *base, u32 offset,
+					    const u32 mask, u32 val)
+{
+	u32 write_val, tmp = readl(base + offset);
+
+	tmp &= ~mask;		/* retain other bits */
+	write_val = tmp | val;
+
+	writel(write_val, base + offset);
+
+	/* Read back to see if val was written */
+	tmp = readl(base + offset);
+	tmp &= mask;		/* clear other bits */
+
+	if (tmp != val)
+		pr_err("write: %x to QSCRATCH: %x FAILED\n", val, offset);
+}
+
+static void qcom_dwc3_hs_phy_shutdown(struct usb_phy *x)
+{
+	struct qcom_dwc3_hs_phy *phy = phy_to_dw_phy(x);
+	int ret;
+
+	ret = regulator_set_voltage(phy->v3p3, 0, PHY_3P3_VOL_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for v3p3\n");
+
+	ret = regulator_set_voltage(phy->v1p8, 0, PHY_1P8_VOL_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for v1p8\n");
+
+	ret = regulator_disable(phy->v1p8);
+	if (ret)
+		dev_err(phy->dev, "cannot disable v1p8\n");
+
+	ret = regulator_disable(phy->v3p3);
+	if (ret)
+		dev_err(phy->dev, "cannot disable v3p3\n");
+
+	ret = regulator_set_voltage(phy->vddcx, USB_VDDCX_NO, USB_VDDCX_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for vddcx\n");
+
+	ret = regulator_disable(phy->vddcx);
+	if (ret)
+		dev_err(phy->dev, "cannot enable vddcx\n");
+
+	clk_disable_unprepare(phy->utmi_clk);
+}
+
+static int qcom_dwc3_hs_phy_init(struct usb_phy *x)
+{
+	struct qcom_dwc3_hs_phy	*phy = phy_to_dw_phy(x);
+	int ret;
+	u32 val;
+
+	clk_prepare_enable(phy->utmi_clk);
+
+	ret = regulator_set_voltage(phy->vddcx, USB_VDDCX_MIN, USB_VDDCX_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for vddcx\n");
+
+	ret = regulator_enable(phy->vddcx);
+	if (ret)
+		dev_err(phy->dev, "cannot enable vddcx\n");
+
+	ret = regulator_set_voltage(phy->v3p3, PHY_3P3_VOL_MIN,
+				    PHY_3P3_VOL_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for v3p3\n");
+
+	ret = regulator_set_voltage(phy->v1p8, PHY_1P8_VOL_MIN,
+				    PHY_1P8_VOL_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for v1p8\n");
+
+	ret = regulator_set_optimum_mode(phy->v1p8, PHY_1P8_HPM_LOAD);
+	if (ret < 0)
+		dev_err(phy->dev, "cannot set HPM of regulator v1p8\n");
+
+	ret = regulator_enable(phy->v1p8);
+	if (ret)
+		dev_err(phy->dev, "cannot enable v1p8\n");
+
+	ret = regulator_set_optimum_mode(phy->v3p3, PHY_3P3_HPM_LOAD);
+	if (ret < 0)
+		dev_err(phy->dev, "cannot set HPM of regulator v3p3\n");
+
+	ret = regulator_enable(phy->v3p3);
+	if (ret)
+		dev_err(phy->dev, "cannot enable v3p3\n");
+
+	/*
+	 * HSPHY Initialization: Enable UTMI clock, select 19.2MHz fsel
+	 * enable clamping, and disable RETENTION (power-on default is ENABLED)
+	 */
+	val = HSUSB_CTRL_DPSEHV_CLAMP | HSUSB_CTRL_DMSEHV_CLAMP |
+		HSUSB_CTRL_RETENABLEN  | HSUSB_CTRL_COMMONONN |
+		HSUSB_CTRL_OTGSESSVLD_CLAMP | HSUSB_CTRL_ID_HV_CLAMP |
+		HSUSB_CTRL_DPSEHV_CLAMP | HSUSB_CTRL_UTMI_OTG_VBUS_VALID |
+		HSUSB_CTRL_UTMI_CLK_EN | HSUSB_CTRL_CLAMP_EN | 0x70;
+
+	/* use core clock if external reference is not present */
+	if (!phy->xo_clk)
+		val |= HSUSB_CTRL_USE_CLKCORE;
+
+	qcom_dwc3_hs_write(phy->base, PHY_CTRL_REG, val);
+	usleep_range(2000, 2200);
+
+	/*
+	 * write HSPHY init value to QSCRATCH reg to set HSPHY parameters like
+	 * VBUS valid threshold, disconnect valid threshold, DC voltage level,
+	 * preempasis and rise/fall time.
+	 */
+	qcom_dwc3_hs_write_readback(phy->base, PARAMETER_OVERRIDE_X_REG,
+				0x03ffffff, 0x00d191a4);
+
+	/* Disable (bypass) VBUS and ID filters */
+	qcom_dwc3_hs_write(phy->base, QSCRATCH_GENERAL_CFG,
+		HSUSB_GCFG_XHCI_REV);
+
+	return 0;
+}
+
+static int qcom_dwc3_hs_phy_set_vbus(struct usb_phy *x, int on)
+{
+	struct qcom_dwc3_hs_phy	*phy = phy_to_dw_phy(x);
+	int ret = 0;
+
+	if (IS_ERR(phy->vbus))
+		return on ? PTR_ERR(phy->vbus) : 0;
+
+	if (on)
+		ret = regulator_enable(phy->vbus);
+	else
+		ret = regulator_disable(phy->vbus);
+
+	if (ret)
+		dev_err(x->dev, "Cannot %s Vbus\n", on ? "set" : "off");
+	return ret;
+}
+
+static int qcom_dwc3_hs_probe(struct platform_device *pdev)
+{
+	struct qcom_dwc3_hs_phy	*phy;
+	struct resource		*res;
+	void __iomem		*base;
+
+	phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, phy);
+
+	phy->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(phy->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	phy->vddcx = devm_regulator_get(phy->dev, "vddcx");
+	if (IS_ERR(phy->vddcx)) {
+		dev_dbg(phy->dev, "cannot get vddcx\n");
+		return  PTR_ERR(phy->vddcx);
+	}
+
+	phy->v3p3 = devm_regulator_get(phy->dev, "v3p3");
+	if (IS_ERR(phy->v3p3)) {
+		dev_dbg(phy->dev, "cannot get v3p3\n");
+		return PTR_ERR(phy->v3p3);
+	}
+
+	phy->v1p8 = devm_regulator_get(phy->dev, "v1p8");
+	if (IS_ERR(phy->v1p8)) {
+		dev_dbg(phy->dev, "cannot get v1p8\n");
+		return PTR_ERR(phy->v1p8);
+	}
+
+	phy->vbus = devm_regulator_get(phy->dev, "vbus");
+	if (IS_ERR(phy->vbus))
+		dev_dbg(phy->dev, "Failed to get vbus\n");
+
+	phy->utmi_clk = devm_clk_get(phy->dev, "utmi");
+	if (IS_ERR(phy->utmi_clk)) {
+		dev_dbg(phy->dev, "cannot get UTMI handle\n");
+		return PTR_ERR(phy->utmi_clk);
+	}
+
+	phy->xo_clk = devm_clk_get(phy->dev, "xo");
+	if (IS_ERR(phy->xo_clk)) {
+		dev_dbg(phy->dev, "cannot get TCXO buffer handle\n");
+		phy->xo_clk = NULL;
+	}
+
+	clk_set_rate(phy->utmi_clk, 60000000);
+
+	if (phy->xo_clk)
+		clk_prepare_enable(phy->xo_clk);
+
+	phy->base		= base;
+	phy->phy.dev		= phy->dev;
+	phy->phy.label		= "qcom-dwc3-hsphy";
+	phy->phy.init		= qcom_dwc3_hs_phy_init;
+	phy->phy.shutdown	= qcom_dwc3_hs_phy_shutdown;
+	phy->phy.set_vbus	= qcom_dwc3_hs_phy_set_vbus;
+	phy->phy.type		= USB_PHY_TYPE_USB2;
+	phy->phy.state          = OTG_STATE_UNDEFINED;
+
+	usb_add_phy_dev(&phy->phy);
+	return 0;
+}
+
+static int qcom_dwc3_hs_remove(struct platform_device *pdev)
+{
+	struct qcom_dwc3_hs_phy *phy = platform_get_drvdata(pdev);
+
+	if (phy->xo_clk)
+		clk_disable_unprepare(phy->xo_clk);
+
+	clk_disable_unprepare(phy->utmi_clk);
+
+	usb_remove_phy(&phy->phy);
+	return 0;
+}
+
+static const struct of_device_id qcom_dwc3_hs_id_table[] = {
+	{ .compatible = "qcom,dwc3-hsphy" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, qcom_dwc3_hs_id_table);
+
+static struct platform_driver qcom_dwc3_hs_driver = {
+	.probe		= qcom_dwc3_hs_probe,
+	.remove		= qcom_dwc3_hs_remove,
+	.driver		= {
+		.name	= "qcom-dwc3-hsphy",
+		.owner	= THIS_MODULE,
+		.of_match_table = qcom_dwc3_hs_id_table,
+	},
+};
+
+module_platform_driver(qcom_dwc3_hs_driver);
+
+MODULE_ALIAS("platform:qcom-dwc3-hsphy");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DesignWare USB3 QCOM HSPHY driver");
diff --git a/drivers/usb/phy/phy-qcom-ssusb.c b/drivers/usb/phy/phy-qcom-ssusb.c
new file mode 100644
index 0000000..d340c8f
--- /dev/null
+++ b/drivers/usb/phy/phy-qcom-ssusb.c
@@ -0,0 +1,385 @@
+/* Copyright (c) 2013-2014, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb/phy.h>
+
+/**
+ *  USB QSCRATCH Hardware registers
+ */
+#define PHY_CTRL_REG			(0x00)
+#define PHY_PARAM_CTRL_1		(0x04)
+#define PHY_PARAM_CTRL_2		(0x08)
+#define CR_PROTOCOL_DATA_IN_REG		(0x0c)
+#define CR_PROTOCOL_DATA_OUT_REG	(0x10)
+#define CR_PROTOCOL_CAP_ADDR_REG	(0x14)
+#define CR_PROTOCOL_CAP_DATA_REG	(0x18)
+#define CR_PROTOCOL_READ_REG		(0x1c)
+#define CR_PROTOCOL_WRITE_REG		(0x20)
+
+#define PHY_1P8_VOL_MIN			1800000 /* uV */
+#define PHY_1P8_VOL_MAX			1800000 /* uV */
+#define PHY_1P8_HPM_LOAD		23000	/* uA */
+
+/* TODO: these are suspicious */
+#define USB_VDDCX_NO			1	/* index */
+#define USB_VDDCX_MIN			5	/* index */
+#define USB_VDDCX_MAX			7	/* index */
+
+/* PHY_CTRL_REG */
+#define SSUSB_CTRL_REF_USE_PAD		BIT(28)
+#define SSUSB_CTRL_TEST_POWERDOWN	BIT(27)
+#define SSUSB_CTRL_LANE0_PWR_PRESENT	BIT(24)
+#define SSUSB_CTRL_SS_PHY_EN		BIT(8)
+#define SSUSB_CTRL_SS_PHY_RESET		BIT(7)
+
+struct qcom_dwc3_ss_phy {
+	struct usb_phy		phy;
+	void __iomem		*base;
+	struct device		*dev;
+
+	struct regulator	*v1p8;
+	struct regulator	*vddcx;
+
+	struct clk		*xo_clk;
+	struct clk		*ref_clk;
+};
+
+#define	phy_to_dw_phy(x)	container_of((x), struct qcom_dwc3_ss_phy, phy)
+
+
+/**
+ * Write register
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @offset - register offset.
+ * @val - value to write.
+ */
+static inline void qcom_dwc3_ss_write(void __iomem *base, u32 offset, u32 val)
+{
+	writel(val, base + offset);
+}
+
+/**
+ * Write register and read back masked value to confirm it is written
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @offset - register offset.
+ * @mask - register bitmask specifying what should be updated
+ * @val - value to write.
+ */
+static inline void qcom_dwc3_ss_write_readback(void __iomem *base, u32 offset,
+					    const u32 mask, u32 val)
+{
+	u32 write_val, tmp = readl(base + offset);
+
+	tmp &= ~mask;		/* retain other bits */
+	write_val = tmp | val;
+
+	writel(write_val, base + offset);
+
+	/* Read back to see if val was written */
+	tmp = readl(base + offset);
+	tmp &= mask;		/* clear other bits */
+
+	if (tmp != val)
+		pr_err("write: %x to QSCRATCH: %x FAILED\n", val, offset);
+}
+
+/**
+ * Write SSPHY register
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @addr - SSPHY address to write.
+ * @val - value to write.
+ */
+static void qcom_dwc3_ss_write_phycreg(void __iomem *base, u32 addr, u32 val)
+{
+	writel(addr, base + CR_PROTOCOL_DATA_IN_REG);
+	writel(0x1, base + CR_PROTOCOL_CAP_ADDR_REG);
+	while (readl(base + CR_PROTOCOL_CAP_ADDR_REG))
+		cpu_relax();
+
+	writel(val, base + CR_PROTOCOL_DATA_IN_REG);
+	writel(0x1, base + CR_PROTOCOL_CAP_DATA_REG);
+	while (readl(base + CR_PROTOCOL_CAP_DATA_REG))
+		cpu_relax();
+
+	writel(0x1, base + CR_PROTOCOL_WRITE_REG);
+	while (readl(base + CR_PROTOCOL_WRITE_REG))
+		cpu_relax();
+}
+
+/**
+ * Read SSPHY register.
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @addr - SSPHY address to read.
+ */
+static u32 qcom_dwc3_ss_read_phycreg(void __iomem *base, u32 addr)
+{
+	bool first_read = true;
+
+	writel(addr, base + CR_PROTOCOL_DATA_IN_REG);
+	writel(0x1, base + CR_PROTOCOL_CAP_ADDR_REG);
+	while (readl(base + CR_PROTOCOL_CAP_ADDR_REG))
+		cpu_relax();
+
+	/*
+	 * Due to hardware bug, first read of SSPHY register might be
+	 * incorrect. Hence as workaround, SW should perform SSPHY register
+	 * read twice, but use only second read and ignore first read.
+	 */
+retry:
+	writel(0x1, base + CR_PROTOCOL_READ_REG);
+	while (readl(base + CR_PROTOCOL_READ_REG))
+		cpu_relax();
+
+	if (first_read) {
+		readl(base + CR_PROTOCOL_DATA_OUT_REG);
+		first_read = false;
+		goto retry;
+	}
+
+	return readl(base + CR_PROTOCOL_DATA_OUT_REG);
+}
+
+static void qcom_dwc3_ss_phy_shutdown(struct usb_phy *x)
+{
+	struct qcom_dwc3_ss_phy *phy = phy_to_dw_phy(x);
+	int ret;
+
+	/* Sequence to put SSPHY in low power state:
+	 * 1. Clear REF_PHY_EN in PHY_CTRL_REG
+	 * 2. Clear REF_USE_PAD in PHY_CTRL_REG
+	 * 3. Set TEST_POWERED_DOWN in PHY_CTRL_REG to enable PHY retention
+	 * 4. Disable SSPHY ref clk
+	 */
+	qcom_dwc3_ss_write_readback(phy->base, PHY_CTRL_REG,
+		SSUSB_CTRL_SS_PHY_EN, 0x0);
+	qcom_dwc3_ss_write_readback(phy->base, PHY_CTRL_REG,
+		SSUSB_CTRL_REF_USE_PAD, 0x0);
+	qcom_dwc3_ss_write_readback(phy->base, PHY_CTRL_REG,
+		0x0, SSUSB_CTRL_TEST_POWERDOWN);
+
+	usleep_range(1000, 1200);
+	clk_disable_unprepare(phy->ref_clk);
+
+	ret = regulator_set_voltage(phy->vddcx, USB_VDDCX_NO, USB_VDDCX_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for vddcx\n");
+
+	regulator_disable(phy->vddcx);
+
+	ret = regulator_set_voltage(phy->v1p8, 0, PHY_1P8_VOL_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set v1p8\n");
+
+	regulator_disable(phy->v1p8);
+}
+
+static int qcom_dwc3_ss_phy_init(struct usb_phy *x)
+{
+	struct qcom_dwc3_ss_phy *phy = phy_to_dw_phy(x);
+	u32 data = 0;
+	int ret;
+
+	ret = regulator_set_voltage(phy->vddcx, USB_VDDCX_MIN, USB_VDDCX_MAX);
+	if (ret)
+		dev_err(phy->dev, "cannot set voltage for vddcx\n");
+
+	ret = regulator_enable(phy->vddcx);
+	if (ret) {
+		dev_err(phy->dev, "cannot enable vddcx\n");
+		return ret;
+	}
+
+	ret = regulator_set_voltage(phy->v1p8, PHY_1P8_VOL_MIN,
+				    PHY_1P8_VOL_MAX);
+	if (ret) {
+		regulator_disable(phy->vddcx);
+		dev_err(phy->dev, "cannot set v1p8\n");
+	}
+
+	ret = regulator_enable(phy->v1p8);
+	if (ret) {
+		regulator_disable(phy->vddcx);
+		dev_err(phy->dev, "cannot enable v1p8\n");
+	}
+
+	clk_prepare_enable(phy->ref_clk);
+	usleep_range(1000, 1200);
+
+	/* reset phy */
+	data = readl_relaxed(phy->base + PHY_CTRL_REG);
+	writel_relaxed(data | SSUSB_CTRL_SS_PHY_RESET,
+		phy->base + PHY_CTRL_REG);
+	usleep_range(2000, 2200);
+	writel_relaxed(data, phy->base + PHY_CTRL_REG);
+
+	/* clear REF_PAD, we don't have XO clk */
+	data &= ~SSUSB_CTRL_REF_USE_PAD;
+	writel_relaxed(data, phy->base + PHY_CTRL_REG);
+	msleep(30);
+
+	data |= SSUSB_CTRL_SS_PHY_EN | SSUSB_CTRL_LANE0_PWR_PRESENT;
+	writel_relaxed(data, phy->base + PHY_CTRL_REG);
+
+	/*
+	 * WORKAROUND: There is SSPHY suspend bug due to which USB enumerates
+	 * in HS mode instead of SS mode. Workaround it by asserting
+	 * LANE0.TX_ALT_BLOCK.EN_ALT_BUS to enable TX to use alt bus mode
+	 */
+	data = qcom_dwc3_ss_read_phycreg(phy->base, 0x102d);
+	data |= (1 << 7);
+	qcom_dwc3_ss_write_phycreg(phy->base, 0x102D, data);
+
+	data = qcom_dwc3_ss_read_phycreg(phy->base, 0x1010);
+	data &= ~0xff0;
+	data |= 0x20;
+	qcom_dwc3_ss_write_phycreg(phy->base, 0x1010, data);
+
+	/*
+	 * Fix RX Equalization setting as follows
+	 * LANE0.RX_OVRD_IN_HI. RX_EQ_EN set to 0
+	 * LANE0.RX_OVRD_IN_HI.RX_EQ_EN_OVRD set to 1
+	 * LANE0.RX_OVRD_IN_HI.RX_EQ set to 3
+	 * LANE0.RX_OVRD_IN_HI.RX_EQ_OVRD set to 1
+	 */
+	data = qcom_dwc3_ss_read_phycreg(phy->base, 0x1006);
+	data &= ~(1 << 6);
+	data |= (1 << 7);
+	data &= ~(0x7 << 8);
+	data |= (0x3 << 8);
+	data |= (0x1 << 11);
+	qcom_dwc3_ss_write_phycreg(phy->base, 0x1006, data);
+
+	/*
+	 * Set EQ and TX launch amplitudes as follows
+	 * LANE0.TX_OVRD_DRV_LO.PREEMPH set to 22
+	 * LANE0.TX_OVRD_DRV_LO.AMPLITUDE set to 127
+	 * LANE0.TX_OVRD_DRV_LO.EN set to 1.
+	 */
+	data = qcom_dwc3_ss_read_phycreg(phy->base, 0x1002);
+	data &= ~0x3f80;
+	data |= (0x16 << 7);
+	data &= ~0x7f;
+	data |= (0x7f | (1 << 14));
+	qcom_dwc3_ss_write_phycreg(phy->base, 0x1002, data);
+
+	/*
+	 * Set the QSCRATCH PHY_PARAM_CTRL1 parameters as follows
+	 * TX_FULL_SWING [26:20] amplitude to 127
+	 * TX_DEEMPH_3_5DB [13:8] to 22
+	 * LOS_BIAS [2:0] to 0x5
+	 */
+	qcom_dwc3_ss_write_readback(phy->base, PHY_PARAM_CTRL_1,
+				   0x07f03f07, 0x07f01605);
+	return 0;
+}
+
+static int qcom_dwc3_ss_probe(struct platform_device *pdev)
+{
+	struct qcom_dwc3_ss_phy	*phy;
+	struct resource		*res;
+	void __iomem		*base;
+	int ret;
+
+	phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
+	if (!phy)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, phy);
+
+	phy->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(phy->dev, res);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	phy->vddcx = devm_regulator_get(phy->dev, "vddcx");
+	if (IS_ERR(phy->vddcx)) {
+		dev_dbg(phy->dev, "cannot get vddcx\n");
+		return  PTR_ERR(phy->vddcx);
+	}
+
+	phy->v1p8 = devm_regulator_get(phy->dev, "v1p8");
+	if (IS_ERR(phy->v1p8)) {
+		dev_dbg(phy->dev, "cannot get v1p8\n");
+		return  PTR_ERR(phy->v1p8);
+	}
+
+	phy->xo_clk = devm_clk_get(phy->dev, "xo");
+	if (IS_ERR(phy->xo_clk)) {
+		dev_dbg(phy->dev, "cannot get XO clk, assuming not present\n");
+		phy->xo_clk = NULL;
+	}
+
+	phy->ref_clk = devm_clk_get(phy->dev, "ref");
+	if (IS_ERR(phy->ref_clk)) {
+		dev_dbg(phy->dev, "cannot get ref clock handle\n");
+		return PTR_ERR(phy->ref_clk);
+	}
+
+	clk_set_rate(phy->ref_clk, 125000000);
+	if (phy->xo_clk)
+		clk_prepare_enable(phy->xo_clk);
+
+	phy->base		= base;
+	phy->phy.dev		= phy->dev;
+	phy->phy.label		= "qcom-dwc3-ssphy";
+	phy->phy.init		= qcom_dwc3_ss_phy_init;
+	phy->phy.shutdown       = qcom_dwc3_ss_phy_shutdown;
+	phy->phy.type		= USB_PHY_TYPE_USB3;
+
+	ret = usb_add_phy_dev(&phy->phy);
+	return ret;
+}
+
+static int qcom_dwc3_ss_remove(struct platform_device *pdev)
+{
+	struct qcom_dwc3_ss_phy *phy = platform_get_drvdata(pdev);
+
+	if (phy->xo_clk)
+		clk_disable_unprepare(phy->xo_clk);
+	usb_remove_phy(&phy->phy);
+	return 0;
+}
+
+static const struct of_device_id qcom_dwc3_ss_id_table[] = {
+	{ .compatible = "qcom,dwc3-ssphy" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, qcom_dwc3_ss_id_table);
+
+static struct platform_driver qcom_dwc3_ss_driver = {
+	.probe		= qcom_dwc3_ss_probe,
+	.remove		= qcom_dwc3_ss_remove,
+	.driver		= {
+		.name	= "qcom-dwc3-ssphy",
+		.owner	= THIS_MODULE,
+		.of_match_table = qcom_dwc3_ss_id_table,
+	},
+};
+
+module_platform_driver(qcom_dwc3_ss_driver);
+
+MODULE_ALIAS("platform:qcom-dwc3-ssphy");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DesignWare USB3 QCOM SSPHY driver");
-- 
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