phy: qcom: Introduce M31 USB PHY driver

Add the M31 USB2 phy driver for the USB M31 PHY
(https://www.m31tech.com) found in Qualcomm IPQ5018, IPQ5332
SoCs.

Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
Reviewed-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/c8821bb0124a54cc774a2ff7b9c40df28eb7711e.1691999761.git.quic_varada@quicinc.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/qualcomm/Kconfig

@@ -143,6 +143,17 @@ config PHY_QCOM_EUSB2_REPEATER
 	  PMICs. The repeater is paired with a Synopsys eUSB2 Phy
 	  on Qualcomm SOCs.
 
+config PHY_QCOM_M31_USB
+	tristate "Qualcomm M31 HS PHY driver support"
+	depends on USB && (ARCH_QCOM || COMPILE_TEST)
+	select GENERIC_PHY
+	help
+	  Enable this to support M31 HS PHY transceivers on Qualcomm 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.
+
 config PHY_QCOM_USB_HS
 	tristate "Qualcomm USB HS PHY module"
 	depends on USB_ULPI_BUS

drivers/phy/qualcomm/Makefile

@@ -4,6 +4,7 @@ obj-$(CONFIG_PHY_QCOM_APQ8064_SATA)	+= phy-qcom-apq8064-sata.o
 obj-$(CONFIG_PHY_QCOM_EDP)		+= phy-qcom-edp.o
 obj-$(CONFIG_PHY_QCOM_IPQ4019_USB)	+= phy-qcom-ipq4019-usb.o
 obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA)	+= phy-qcom-ipq806x-sata.o
+obj-$(CONFIG_PHY_QCOM_M31_USB)		+= phy-qcom-m31.o
 obj-$(CONFIG_PHY_QCOM_PCIE2)		+= phy-qcom-pcie2.o
 
 obj-$(CONFIG_PHY_QCOM_QMP_COMBO)	+= phy-qcom-qmp-combo.o

drivers/phy/qualcomm/phy-qcom-m31.c

@@ -0,0 +1,294 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2014-2023, 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/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+#define USB2PHY_PORT_UTMI_CTRL1		0x40
+
+#define USB2PHY_PORT_UTMI_CTRL2		0x44
+ #define UTMI_ULPI_SEL			BIT(7)
+ #define UTMI_TEST_MUX_SEL		BIT(6)
+
+#define HS_PHY_CTRL_REG			0x10
+ #define UTMI_OTG_VBUS_VALID		BIT(20)
+ #define SW_SESSVLD_SEL			BIT(28)
+
+#define USB_PHY_UTMI_CTRL0		0x3c
+
+#define USB_PHY_UTMI_CTRL5		0x50
+ #define POR_EN				BIT(1)
+
+#define USB_PHY_HS_PHY_CTRL_COMMON0	0x54
+ #define COMMONONN			BIT(7)
+ #define FSEL				BIT(4)
+ #define RETENABLEN			BIT(3)
+ #define FREQ_24MHZ			(BIT(6) | BIT(4))
+
+#define USB_PHY_HS_PHY_CTRL2		0x64
+ #define USB2_SUSPEND_N_SEL		BIT(3)
+ #define USB2_SUSPEND_N			BIT(2)
+ #define USB2_UTMI_CLK_EN		BIT(1)
+
+#define USB_PHY_CFG0			0x94
+ #define UTMI_PHY_OVERRIDE_EN		BIT(1)
+
+#define USB_PHY_REFCLK_CTRL		0xa0
+ #define CLKCORE			BIT(1)
+
+#define USB2PHY_PORT_POWERDOWN		0xa4
+ #define POWER_UP			BIT(0)
+ #define POWER_DOWN			0
+
+#define USB_PHY_FSEL_SEL		0xb8
+ #define FREQ_SEL			BIT(0)
+
+#define USB2PHY_USB_PHY_M31_XCFGI_1	0xbc
+ #define USB2_0_TX_ENABLE		BIT(2)
+
+#define USB2PHY_USB_PHY_M31_XCFGI_4	0xc8
+ #define HSTX_SLEW_RATE_565PS		GENMASK(1, 0)
+ #define PLL_CHARGING_PUMP_CURRENT_35UA	GENMASK(4, 3)
+ #define ODT_VALUE_38_02_OHM		GENMASK(7, 6)
+
+#define USB2PHY_USB_PHY_M31_XCFGI_5	0xcc
+ #define ODT_VALUE_45_02_OHM		BIT(2)
+ #define HSTX_PRE_EMPHASIS_LEVEL_0_55MA	BIT(0)
+
+#define USB2PHY_USB_PHY_M31_XCFGI_11	0xe4
+ #define XCFG_COARSE_TUNE_NUM		BIT(1)
+ #define XCFG_FINE_TUNE_NUM		BIT(3)
+
+struct m31_phy_regs {
+	u32 off;
+	u32 val;
+	u32 delay;
+};
+
+struct m31_priv_data {
+	bool				ulpi_mode;
+	const struct m31_phy_regs	*regs;
+	unsigned int			nregs;
+};
+
+struct m31_phy_regs m31_ipq5332_regs[] = {
+	{
+		USB_PHY_CFG0,
+		UTMI_PHY_OVERRIDE_EN,
+		0
+	},
+	{
+		USB_PHY_UTMI_CTRL5,
+		POR_EN,
+		15
+	},
+	{
+		USB_PHY_FSEL_SEL,
+		FREQ_SEL,
+		0
+	},
+	{
+		USB_PHY_HS_PHY_CTRL_COMMON0,
+		COMMONONN | FREQ_24MHZ | RETENABLEN,
+		0
+	},
+	{
+		USB_PHY_UTMI_CTRL5,
+		POR_EN,
+		0
+	},
+	{
+		USB_PHY_HS_PHY_CTRL2,
+		USB2_SUSPEND_N_SEL | USB2_SUSPEND_N | USB2_UTMI_CLK_EN,
+		0
+	},
+	{
+		USB2PHY_USB_PHY_M31_XCFGI_11,
+		XCFG_COARSE_TUNE_NUM  | XCFG_FINE_TUNE_NUM,
+		0
+	},
+	{
+		USB2PHY_USB_PHY_M31_XCFGI_4,
+		HSTX_SLEW_RATE_565PS | PLL_CHARGING_PUMP_CURRENT_35UA | ODT_VALUE_38_02_OHM,
+		0
+	},
+	{
+		USB2PHY_USB_PHY_M31_XCFGI_1,
+		USB2_0_TX_ENABLE,
+		0
+	},
+	{
+		USB2PHY_USB_PHY_M31_XCFGI_5,
+		ODT_VALUE_45_02_OHM | HSTX_PRE_EMPHASIS_LEVEL_0_55MA,
+		4
+	},
+	{
+		USB_PHY_UTMI_CTRL5,
+		0x0,
+		0
+	},
+	{
+		USB_PHY_HS_PHY_CTRL2,
+		USB2_SUSPEND_N | USB2_UTMI_CLK_EN,
+		0
+	},
+};
+
+struct m31usb_phy {
+	struct phy			*phy;
+	void __iomem			*base;
+	const struct m31_phy_regs	*regs;
+	int				nregs;
+
+	struct regulator		*vreg;
+	struct clk			*clk;
+	struct reset_control		*reset;
+
+	bool				ulpi_mode;
+};
+
+static int m31usb_phy_init(struct phy *phy)
+{
+	struct m31usb_phy *qphy = phy_get_drvdata(phy);
+	const struct m31_phy_regs *regs = qphy->regs;
+	int i, ret;
+
+	ret = regulator_enable(qphy->vreg);
+	if (ret) {
+		dev_err(&phy->dev, "failed to enable regulator, %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(qphy->clk);
+	if (ret) {
+		if (qphy->vreg)
+			regulator_disable(qphy->vreg);
+		dev_err(&phy->dev, "failed to enable cfg ahb clock, %d\n", ret);
+		return ret;
+	}
+
+	/* Perform phy reset */
+	reset_control_assert(qphy->reset);
+	udelay(5);
+	reset_control_deassert(qphy->reset);
+
+	/* configure for ULPI mode if requested */
+	if (qphy->ulpi_mode)
+		writel(0x0, qphy->base + USB2PHY_PORT_UTMI_CTRL2);
+
+	/* Enable the PHY */
+	writel(POWER_UP, qphy->base + USB2PHY_PORT_POWERDOWN);
+
+	/* Turn on phy ref clock */
+	for (i = 0; i < qphy->nregs; i++) {
+		writel(regs[i].val, qphy->base + regs[i].off);
+		if (regs[i].delay)
+			udelay(regs[i].delay);
+	}
+
+	return 0;
+}
+
+static int m31usb_phy_shutdown(struct phy *phy)
+{
+	struct m31usb_phy *qphy = phy_get_drvdata(phy);
+
+	/* Disable the PHY */
+	writel_relaxed(POWER_DOWN, qphy->base + USB2PHY_PORT_POWERDOWN);
+
+	clk_disable_unprepare(qphy->clk);
+
+	regulator_disable(qphy->vreg);
+
+	return 0;
+}
+
+static const struct phy_ops m31usb_phy_gen_ops = {
+	.power_on	= m31usb_phy_init,
+	.power_off	= m31usb_phy_shutdown,
+	.owner		= THIS_MODULE,
+};
+
+static int m31usb_phy_probe(struct platform_device *pdev)
+{
+	struct phy_provider *phy_provider;
+	const struct m31_priv_data *data;
+	struct device *dev = &pdev->dev;
+	struct m31usb_phy *qphy;
+
+	qphy = devm_kzalloc(dev, sizeof(*qphy), GFP_KERNEL);
+	if (!qphy)
+		return -ENOMEM;
+
+	qphy->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(qphy->base))
+		return PTR_ERR(qphy->base);
+
+	qphy->reset = devm_reset_control_get_exclusive_by_index(dev, 0);
+	if (IS_ERR(qphy->reset))
+		return PTR_ERR(qphy->reset);
+
+	qphy->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(qphy->clk))
+		return dev_err_probe(dev, PTR_ERR(qphy->clk),
+						"failed to get clk\n");
+
+	data = of_device_get_match_data(dev);
+	qphy->regs		= data->regs;
+	qphy->nregs		= data->nregs;
+	qphy->ulpi_mode		= data->ulpi_mode;
+
+	qphy->phy = devm_phy_create(dev, NULL, &m31usb_phy_gen_ops);
+	if (IS_ERR(qphy->phy))
+		return dev_err_probe(dev, PTR_ERR(qphy->phy),
+						"failed to create phy\n");
+
+	qphy->vreg = devm_regulator_get(dev, "vdda-phy");
+	if (IS_ERR(qphy->vreg))
+		return dev_err_probe(dev, PTR_ERR(qphy->phy),
+						"failed to get vreg\n");
+
+	phy_set_drvdata(qphy->phy, qphy);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (!IS_ERR(phy_provider))
+		dev_info(dev, "Registered M31 USB phy\n");
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct m31_priv_data m31_ipq5332_data = {
+	.ulpi_mode = false,
+	.regs = m31_ipq5332_regs,
+	.nregs = ARRAY_SIZE(m31_ipq5332_regs),
+};
+
+static const struct of_device_id m31usb_phy_id_table[] = {
+	{ .compatible = "qcom,ipq5332-usb-hsphy", .data = &m31_ipq5332_data },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, m31usb_phy_id_table);
+
+static struct platform_driver m31usb_phy_driver = {
+	.probe = m31usb_phy_probe,
+	.driver = {
+		.name = "qcom-m31usb-phy",
+		.of_match_table = m31usb_phy_id_table,
+	},
+};
+
+module_platform_driver(m31usb_phy_driver);
+
+MODULE_DESCRIPTION("USB2 Qualcomm M31 HSPHY driver");
+MODULE_LICENSE("GPL");