[PATCH v3 3/6] phy: qcom-m31: Introduce qcom,m31 USB phy driver

[Varadarajan Narayanan]

Add the M31 USB2 phy driver.

Signed-off-by: Varadarajan Narayanan <quic_varada@xxxxxxxxxxx>
---
v1:
	Combine driver, makefile and kconfig into 1 patch
	Remove 'qscratch' region and its usage. The controller driver takes care
	of those settings
	Use compatible/data to handle ipq5332 init
	Drop the default case
	Get resources by index instead of name as there is only one resource
	Add clock
	Fix review comments in the driver
---
 drivers/phy/qualcomm/Kconfig        |  11 ++
 drivers/phy/qualcomm/Makefile       |   1 +
 drivers/phy/qualcomm/phy-qcom-m31.c | 256 ++++++++++++++++++++++++++++++++++++
 3 files changed, 268 insertions(+)
 create mode 100644 drivers/phy/qualcomm/phy-qcom-m31.c

diff --git a/drivers/phy/qualcomm/Kconfig b/drivers/phy/qualcomm/Kconfig
index 97ca595..76be191 100644
--- a/drivers/phy/qualcomm/Kconfig
+++ b/drivers/phy/qualcomm/Kconfig
@@ -197,3 +197,14 @@ config PHY_QCOM_SGMII_ETH
 	help
 	  Enable this to support the internal SerDes/SGMII PHY on various
 	  Qualcomm chipsets.
+
+config PHY_QCOM_M31_USB
+	tristate "Qualcomm M31 HS PHY driver support"
+	depends on (USB || USB_GADGET) && ARCH_QCOM
+	select USB_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.
diff --git a/drivers/phy/qualcomm/Makefile b/drivers/phy/qualcomm/Makefile
index b030858..0b5dd66 100644
--- a/drivers/phy/qualcomm/Makefile
+++ b/drivers/phy/qualcomm/Makefile
@@ -22,3 +22,4 @@ 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
 obj-$(CONFIG_PHY_QCOM_IPQ806X_USB)	+= phy-qcom-ipq806x-usb.o
 obj-$(CONFIG_PHY_QCOM_SGMII_ETH)	+= phy-qcom-sgmii-eth.o
+obj-$(CONFIG_PHY_QCOM_M31_USB)		+= phy-qcom-m31.o
diff --git a/drivers/phy/qualcomm/phy-qcom-m31.c b/drivers/phy/qualcomm/phy-qcom-m31.c
new file mode 100644
index 0000000..8700728
--- /dev/null
+++ b/drivers/phy/qualcomm/phy-qcom-m31.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2014-2016, 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_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/usb/of.h>
+#include <linux/usb/phy.h>
+
+enum clk_reset_action {
+	CLK_RESET_DEASSERT	= 0,
+	CLK_RESET_ASSERT	= 1
+};
+
+
+#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 ATERESET			~BIT(0)
+
+#define USB_PHY_HS_PHY_CTRL_COMMON0	0x54
+ #define COMMONONN			BIT(7)
+ #define FSEL				BIT(4)
+ #define RETENABLEN			BIT(3)
+ #define FREQ_24MHZ			(5 << 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;
+};
+
+#define M31_REG(__o, __v, __d)	\
+	{ .off = __o, .val = __v, .delay = __d }
+
+#define M31_REG_INVALID			0xffffffffu
+
+struct m31_phy_regs m31_ipq5332_regs[] = {
+	M31_REG(USB_PHY_CFG0, UTMI_PHY_OVERRIDE_EN, 0),
+	M31_REG(USB_PHY_UTMI_CTRL5, POR_EN, 15),
+	M31_REG(USB_PHY_FSEL_SEL, FREQ_SEL, 0),
+	M31_REG(USB_PHY_HS_PHY_CTRL_COMMON0,
+		COMMONONN | FREQ_24MHZ | RETENABLEN, 0),
+	M31_REG(USB_PHY_UTMI_CTRL5, POR_EN & ATERESET, 0),
+	M31_REG(USB_PHY_HS_PHY_CTRL2,
+		USB2_SUSPEND_N_SEL | USB2_SUSPEND_N | USB2_UTMI_CLK_EN, 0),
+	M31_REG(USB2PHY_USB_PHY_M31_XCFGI_11,
+		XCFG_COARSE_TUNE_NUM  | XCFG_FINE_TUNE_NUM, 0),
+	M31_REG(USB2PHY_USB_PHY_M31_XCFGI_4,
+		HSTX_SLEW_RATE_565PS | PLL_CHARGING_PUMP_CURRENT_35UA |
+		ODT_VALUE_38_02_OHM, 0),
+	M31_REG(USB2PHY_USB_PHY_M31_XCFGI_1, USB2_0_TX_ENABLE, 0),
+	M31_REG(USB2PHY_USB_PHY_M31_XCFGI_5,
+		ODT_VALUE_45_02_OHM | HSTX_PRE_EMPHASIS_LEVEL_0_55MA, 4),
+	M31_REG(USB_PHY_UTMI_CTRL5, 0x0, 0),
+	M31_REG(USB_PHY_HS_PHY_CTRL2, USB2_SUSPEND_N | USB2_UTMI_CLK_EN, 0),
+	M31_REG(M31_REG_INVALID, 0, 0),
+};
+
+struct m31usb_phy {
+	struct usb_phy			phy;
+	void __iomem			*base;
+	const struct m31_phy_regs	*regs;
+
+	struct clk			*cfg_ahb_clk;
+	struct reset_control		*phy_reset;
+
+	bool				cable_connected;
+	bool				suspended;
+	bool				ulpi_mode;
+};
+
+static void m31usb_phy_enable_clock(struct m31usb_phy *qphy)
+{
+	const struct m31_phy_regs *regs = qphy->regs;
+
+	for (; regs->off != M31_REG_INVALID; regs++) {
+		writel(regs->val, qphy->base + regs->off);
+		if (regs->delay)
+			udelay(regs->delay);
+	}
+}
+
+static int m31usb_phy_init(struct usb_phy *phy)
+{
+	int ret;
+	struct m31usb_phy *qphy = container_of(phy, struct m31usb_phy, phy);
+
+	ret = clk_prepare_enable(qphy->cfg_ahb_clk);
+	if (ret) {
+		dev_err(phy->dev, "failed to enable cfg ahb clock, %d\n", ret);
+		return ret;
+	}
+
+	/* Perform phy reset */
+	reset_control_assert(qphy->phy_reset);
+	udelay(5);
+	reset_control_deassert(qphy->phy_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);
+
+	/* Make sure above write completed */
+	wmb();
+
+	/* Turn on phy ref clock */
+	m31usb_phy_enable_clock(qphy);
+
+	return 0;
+}
+
+static void m31usb_phy_shutdown(struct usb_phy *phy)
+{
+	struct m31usb_phy *qphy = container_of(phy, struct m31usb_phy, phy);
+
+	/* Disable the PHY */
+	writel_relaxed(POWER_DOWN, qphy->base + USB2PHY_PORT_POWERDOWN);
+	/* Make sure above write completed */
+	wmb();
+
+	clk_disable_unprepare(qphy->cfg_ahb_clk);
+}
+
+static int m31usb_phy_probe(struct platform_device *pdev)
+{
+	const struct m31_priv_data *data;
+	struct device *dev = &pdev->dev;
+	struct m31usb_phy *qphy;
+	int ret;
+
+	qphy = devm_kzalloc(dev, sizeof(*qphy), GFP_KERNEL);
+	if (!qphy)
+		return -ENOMEM;
+
+	qphy->phy.dev = dev;
+
+	qphy->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(qphy->base))
+		return PTR_ERR(qphy->base);
+
+	qphy->phy_reset = devm_reset_control_get_exclusive_by_index(dev, 0);
+	if (IS_ERR(qphy->phy_reset))
+		return PTR_ERR(qphy->phy_reset);
+
+	qphy->cfg_ahb_clk = devm_clk_get(dev, "cfg_ahb");
+	platform_set_drvdata(pdev, qphy);
+
+	data = of_device_get_match_data(dev);
+	qphy->regs = data->regs;
+	qphy->ulpi_mode = data->ulpi_mode;
+
+	qphy->phy.label			= "m31-usb-phy";
+	qphy->phy.init			= m31usb_phy_init;
+	qphy->phy.shutdown		= m31usb_phy_shutdown;
+	qphy->phy.type			= USB_PHY_TYPE_USB2;
+
+	ret = usb_add_phy_dev(&qphy->phy);
+
+	return ret;
+}
+
+static void m31usb_phy_remove(struct platform_device *pdev)
+{
+	struct m31usb_phy *qphy = platform_get_drvdata(pdev);
+
+	usb_remove_phy(&qphy->phy);
+}
+
+struct m31_priv_data m31_ipq5332_data = {
+	.ulpi_mode = false,
+	.regs = 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,
+	.remove_new	= m31usb_phy_remove,
+	.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");
-- 
2.7.4