phy: qcom-snps: Add SNPS USB PHY driver for QCOM based SOCs

This adds the SNPS FemtoPHY V2 driver used in QCOM SOCs.  There
are potentially multiple instances of this UTMI PHY on the
SOC, all which can utilize this driver.  The V2 driver will
have a different register map compared to V1.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Reviewed-by: Philipp Zabel <pza@pengutronix.de>
Reviewed-by: Manu Gautam <mgautam@codeaurora.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/1588636467-23409-3-git-send-email-wcheng@codeaurora.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/qualcomm/Kconfig

@@ -92,6 +92,16 @@ config PHY_QCOM_USB_HS
 	  Support for the USB high-speed ULPI compliant phy on Qualcomm
 	  chipsets.
 
+config PHY_QCOM_USB_SNPS_FEMTO_V2
+	tristate "Qualcomm SNPS FEMTO USB HS PHY V2 module"
+	depends on OF && (ARCH_QCOM || COMPILE_TEST)
+	select GENERIC_PHY
+	help
+	  Enable support for the USB high-speed SNPS Femto phy on Qualcomm
+	  chipsets.  This PHY has differences in the register map compared
+	  to the V1 variants.  The PHY is paired with a Synopsys DWC3 USB
+	  controller on Qualcomm SOCs.
+
 config PHY_QCOM_USB_HSIC
 	tristate "Qualcomm USB HSIC ULPI PHY module"
 	depends on USB_ULPI_BUS

drivers/phy/qualcomm/Makefile

@@ -13,3 +13,4 @@ obj-$(CONFIG_PHY_QCOM_USB_HS) 		+= phy-qcom-usb-hs.o
 obj-$(CONFIG_PHY_QCOM_USB_HSIC) 	+= phy-qcom-usb-hsic.o
 obj-$(CONFIG_PHY_QCOM_USB_HS_28NM)	+= phy-qcom-usb-hs-28nm.o
 obj-$(CONFIG_PHY_QCOM_USB_SS)		+= phy-qcom-usb-ss.o
+obj-$(CONFIG_PHY_QCOM_USB_SNPS_FEMTO_V2)+= phy-qcom-snps-femto-v2.o

drivers/phy/qualcomm/phy-qcom-snps-femto-v2.c

@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#define USB2_PHY_USB_PHY_UTMI_CTRL0		(0x3c)
+#define SLEEPM					BIT(0)
+#define OPMODE_MASK				GENMASK(4, 3)
+#define OPMODE_NORMAL				(0x00)
+#define OPMODE_NONDRIVING			BIT(3)
+#define TERMSEL					BIT(5)
+
+#define USB2_PHY_USB_PHY_UTMI_CTRL1		(0x40)
+#define XCVRSEL					BIT(0)
+
+#define USB2_PHY_USB_PHY_UTMI_CTRL5		(0x50)
+#define POR					BIT(1)
+
+#define USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON0	(0x54)
+#define RETENABLEN				BIT(3)
+#define FSEL_MASK				GENMASK(7, 5)
+#define FSEL_DEFAULT				(0x3 << 4)
+
+#define USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON1	(0x58)
+#define VBUSVLDEXTSEL0				BIT(4)
+#define PLLBTUNE				BIT(5)
+
+#define USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON2	(0x5c)
+#define VREGBYPASS				BIT(0)
+
+#define USB2_PHY_USB_PHY_HS_PHY_CTRL1		(0x60)
+#define VBUSVLDEXT0				BIT(0)
+
+#define USB2_PHY_USB_PHY_HS_PHY_CTRL2		(0x64)
+#define USB2_AUTO_RESUME			BIT(0)
+#define USB2_SUSPEND_N				BIT(2)
+#define USB2_SUSPEND_N_SEL			BIT(3)
+
+#define USB2_PHY_USB_PHY_CFG0			(0x94)
+#define UTMI_PHY_DATAPATH_CTRL_OVERRIDE_EN	BIT(0)
+#define UTMI_PHY_CMN_CTRL_OVERRIDE_EN		BIT(1)
+
+#define USB2_PHY_USB_PHY_REFCLK_CTRL		(0xa0)
+#define REFCLK_SEL_MASK				GENMASK(1, 0)
+#define REFCLK_SEL_DEFAULT			(0x2 << 0)
+
+static const char * const qcom_snps_hsphy_vreg_names[] = {
+	"vdda-pll", "vdda33", "vdda18",
+};
+
+#define SNPS_HS_NUM_VREGS		ARRAY_SIZE(qcom_snps_hsphy_vreg_names)
+
+/**
+ * struct qcom_snps_hsphy - snps hs phy attributes
+ *
+ * @phy: generic phy
+ * @base: iomapped memory space for snps hs phy
+ *
+ * @cfg_ahb_clk: AHB2PHY interface clock
+ * @ref_clk: phy reference clock
+ * @iface_clk: phy interface clock
+ * @phy_reset: phy reset control
+ * @vregs: regulator supplies bulk data
+ * @phy_initialized: if PHY has been initialized correctly
+ */
+struct qcom_snps_hsphy {
+	struct phy *phy;
+	void __iomem *base;
+
+	struct clk *cfg_ahb_clk;
+	struct clk *ref_clk;
+	struct reset_control *phy_reset;
+	struct regulator_bulk_data vregs[SNPS_HS_NUM_VREGS];
+
+	bool phy_initialized;
+};
+
+static inline void qcom_snps_hsphy_write_mask(void __iomem *base, u32 offset,
+						u32 mask, u32 val)
+{
+	u32 reg;
+
+	reg = readl_relaxed(base + offset);
+	reg &= ~mask;
+	reg |= val & mask;
+	writel_relaxed(reg, base + offset);
+
+	/* Ensure above write is completed */
+	readl_relaxed(base + offset);
+}
+
+static int qcom_snps_hsphy_init(struct phy *phy)
+{
+	struct qcom_snps_hsphy *hsphy = phy_get_drvdata(phy);
+	int ret;
+
+	dev_vdbg(&phy->dev, "%s(): Initializing SNPS HS phy\n", __func__);
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(hsphy->vregs), hsphy->vregs);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(hsphy->cfg_ahb_clk);
+	if (ret) {
+		dev_err(&phy->dev, "failed to enable cfg ahb clock, %d\n", ret);
+		goto poweroff_phy;
+	}
+
+	ret = reset_control_assert(hsphy->phy_reset);
+	if (ret) {
+		dev_err(&phy->dev, "failed to assert phy_reset, %d\n", ret);
+		goto disable_ahb_clk;
+	}
+
+	usleep_range(100, 150);
+
+	ret = reset_control_deassert(hsphy->phy_reset);
+	if (ret) {
+		dev_err(&phy->dev, "failed to de-assert phy_reset, %d\n", ret);
+		goto disable_ahb_clk;
+	}
+
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_CFG0,
+					UTMI_PHY_CMN_CTRL_OVERRIDE_EN,
+					UTMI_PHY_CMN_CTRL_OVERRIDE_EN);
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_UTMI_CTRL5,
+							POR, POR);
+	qcom_snps_hsphy_write_mask(hsphy->base,
+					USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON0,
+					FSEL_MASK, 0);
+	qcom_snps_hsphy_write_mask(hsphy->base,
+					USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON1,
+					PLLBTUNE, PLLBTUNE);
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_REFCLK_CTRL,
+					REFCLK_SEL_DEFAULT, REFCLK_SEL_MASK);
+	qcom_snps_hsphy_write_mask(hsphy->base,
+					USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON1,
+					VBUSVLDEXTSEL0, VBUSVLDEXTSEL0);
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_HS_PHY_CTRL1,
+					VBUSVLDEXT0, VBUSVLDEXT0);
+
+	qcom_snps_hsphy_write_mask(hsphy->base,
+					USB2_PHY_USB_PHY_HS_PHY_CTRL_COMMON2,
+					VREGBYPASS, VREGBYPASS);
+
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_HS_PHY_CTRL2,
+					USB2_SUSPEND_N_SEL | USB2_SUSPEND_N,
+					USB2_SUSPEND_N_SEL | USB2_SUSPEND_N);
+
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_UTMI_CTRL0,
+					SLEEPM, SLEEPM);
+
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_UTMI_CTRL5,
+					POR, 0);
+
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_HS_PHY_CTRL2,
+					USB2_SUSPEND_N_SEL, 0);
+
+	qcom_snps_hsphy_write_mask(hsphy->base, USB2_PHY_USB_PHY_CFG0,
+					UTMI_PHY_CMN_CTRL_OVERRIDE_EN, 0);
+
+	hsphy->phy_initialized = true;
+
+	return 0;
+
+disable_ahb_clk:
+	clk_disable_unprepare(hsphy->cfg_ahb_clk);
+poweroff_phy:
+	regulator_bulk_disable(ARRAY_SIZE(hsphy->vregs), hsphy->vregs);
+
+	return ret;
+}
+
+static int qcom_snps_hsphy_exit(struct phy *phy)
+{
+	struct qcom_snps_hsphy *hsphy = phy_get_drvdata(phy);
+
+	reset_control_assert(hsphy->phy_reset);
+	clk_disable_unprepare(hsphy->cfg_ahb_clk);
+	regulator_bulk_disable(ARRAY_SIZE(hsphy->vregs), hsphy->vregs);
+	hsphy->phy_initialized = false;
+
+	return 0;
+}
+
+static const struct phy_ops qcom_snps_hsphy_gen_ops = {
+	.init		= qcom_snps_hsphy_init,
+	.exit		= qcom_snps_hsphy_exit,
+	.owner		= THIS_MODULE,
+};
+
+static const struct of_device_id qcom_snps_hsphy_of_match_table[] = {
+	{ .compatible	= "qcom,sm8150-usb-hs-phy", },
+	{ .compatible	= "qcom,usb-snps-hs-7nm-phy", },
+	{ .compatible	= "qcom,usb-snps-femto-v2-phy",	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, qcom_snps_hsphy_of_match_table);
+
+static int qcom_snps_hsphy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct qcom_snps_hsphy *hsphy;
+	struct phy_provider *phy_provider;
+	struct phy *generic_phy;
+	int ret, i;
+	int num;
+
+	hsphy = devm_kzalloc(dev, sizeof(*hsphy), GFP_KERNEL);
+	if (!hsphy)
+		return -ENOMEM;
+
+	hsphy->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(hsphy->base))
+		return PTR_ERR(hsphy->base);
+
+	hsphy->ref_clk = devm_clk_get(dev, "ref");
+	if (IS_ERR(hsphy->ref_clk)) {
+		ret = PTR_ERR(hsphy->ref_clk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "failed to get ref clk, %d\n", ret);
+		return ret;
+	}
+
+	hsphy->phy_reset = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(hsphy->phy_reset)) {
+		dev_err(dev, "failed to get phy core reset\n");
+		return PTR_ERR(hsphy->phy_reset);
+	}
+
+	num = ARRAY_SIZE(hsphy->vregs);
+	for (i = 0; i < num; i++)
+		hsphy->vregs[i].supply = qcom_snps_hsphy_vreg_names[i];
+
+	ret = devm_regulator_bulk_get(dev, num, hsphy->vregs);
+	if (ret) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "failed to get regulator supplies: %d\n",
+				ret);
+		return ret;
+	}
+
+	generic_phy = devm_phy_create(dev, NULL, &qcom_snps_hsphy_gen_ops);
+	if (IS_ERR(generic_phy)) {
+		ret = PTR_ERR(generic_phy);
+		dev_err(dev, "failed to create phy, %d\n", ret);
+		return ret;
+	}
+	hsphy->phy = generic_phy;
+
+	dev_set_drvdata(dev, hsphy);
+	phy_set_drvdata(generic_phy, hsphy);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (!IS_ERR(phy_provider))
+		dev_dbg(dev, "Registered Qcom-SNPS HS phy\n");
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static struct platform_driver qcom_snps_hsphy_driver = {
+	.probe		= qcom_snps_hsphy_probe,
+	.driver = {
+		.name	= "qcom-snps-hs-femto-v2-phy",
+		.of_match_table = qcom_snps_hsphy_of_match_table,
+	},
+};
+
+module_platform_driver(qcom_snps_hsphy_driver);
+
+MODULE_DESCRIPTION("Qualcomm SNPS FEMTO USB HS PHY V2 driver");
+MODULE_LICENSE("GPL v2");