Date:	Fri, 17 Jun 2016 12:25:18 +0200
From:	Neil Armstrong <narmstrong@...libre.com>
To:	balbi@...nel.org, gregkh@...uxfoundation.org
Cc:	Neil Armstrong <narmstrong@...libre.com>,
	linux-kernel@...r.kernel.org, linux-usb@...r.kernel.org
Subject: [PATCH 1/2] usb: phy: Add initial support for Qualcomm HSIC PHY

Add support for the HSIC PHY present in the Qualcomm MSM9615 SoC.
This PHY is also present on other SoCs and would need some changes.

Signed-off-by: Neil Armstrong <narmstrong@...libre.com>
---
 drivers/usb/phy/Kconfig             |  13 +
 drivers/usb/phy/Makefile            |   1 +
 drivers/usb/phy/phy-qcom-hsic-usb.c | 506 ++++++++++++++++++++++++++++++++++++
 3 files changed, 520 insertions(+)
 create mode 100644 drivers/usb/phy/phy-qcom-hsic-usb.c

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index c690474..b131e50 100644
--- a/drivers/usb/phy/Kconfig
+++ b/drivers/usb/phy/Kconfig
@@ -166,6 +166,19 @@ config USB_QCOM_8X16_PHY
 	  To compile this driver as a module, choose M here: the
 	  module will be called phy-qcom-8x16-usb.
 
+config USB_QCOM_HSIC_PHY
+	tristate "Qualcomm HSIC USB PHY controller support"
+	depends on ARCH_QCOM || COMPILE_TEST
+	depends on RESET_CONTROLLER && EXTCON
+	select USB_PHY
+	help
+	  Enable this to support the HSIC USB transceiver on Qualcomm chipsets.
+	  It handles PHY initialization, clock management, power management,
+	  and workarounds required after resetting the hardware.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called phy-qcom-hsic-usb.
+
 config USB_MV_OTG
 	tristate "Marvell USB OTG support"
 	depends on USB_EHCI_MV && USB_MV_UDC && PM && USB_OTG
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index b433e5d..f250632 100644
--- a/drivers/usb/phy/Makefile
+++ b/drivers/usb/phy/Makefile
@@ -21,6 +21,7 @@ obj-$(CONFIG_USB_GPIO_VBUS)		+= phy-gpio-vbus-usb.o
 obj-$(CONFIG_USB_ISP1301)		+= phy-isp1301.o
 obj-$(CONFIG_USB_MSM_OTG)		+= phy-msm-usb.o
 obj-$(CONFIG_USB_QCOM_8X16_PHY)	+= phy-qcom-8x16-usb.o
+obj-$(CONFIG_USB_QCOM_HSIC_PHY)	+= phy-qcom-hsic-usb.o
 obj-$(CONFIG_USB_MV_OTG)		+= phy-mv-usb.o
 obj-$(CONFIG_USB_MXS_PHY)		+= phy-mxs-usb.o
 obj-$(CONFIG_USB_ULPI)			+= phy-ulpi.o
diff --git a/drivers/usb/phy/phy-qcom-hsic-usb.c b/drivers/usb/phy/phy-qcom-hsic-usb.c
new file mode 100644
index 0000000..7d233cb
--- /dev/null
+++ b/drivers/usb/phy/phy-qcom-hsic-usb.c
@@ -0,0 +1,506 @@
+/*
+ * Copyright (c) 2015, Baylibre SAS
+ * Based on phy-qcom-hsic-usb.c
+ * Copyright (c) 2015, Linaro Limited
+ *
+ * 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/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/extcon.h>
+#include <linux/gpio/consumer.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/ulpi.h>
+#include <linux/usb/hcd.h>
+#include <linux/usb/msm_hsusb_hw.h>
+#include <linux/regmap.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
+#include <linux/mfd/syscon.h>
+
+#define HSPHY_ULPI_VIEWPORT	0x0170
+
+#define USB_PHY_VDD_DIG_VOL_MIN	1000000 /* uV */
+#define USB_PHY_VDD_DIG_VOL_MAX	1320000 /* uV */
+#define USB_PHY_SUSP_DIG_VOL	500000  /* uV */
+
+#define ULPI_IO_TIMEOUT_USEC	(10 * 1000)
+
+#define HSIC_DBG1_REG		0x38
+#define HSIC_CFG_REG		0x30
+#define HSIC_CFG1_REG		0x31
+#define HSIC_IO_CAL_PER_REG	0x33
+
+#define HSIC_CAL_PAD_CTL	0x20C8
+#define HSIC_LV_MODE		0x04
+#define HSIC_PAD_CALIBRATION	0xA8
+
+#define MSM_USB_BASE (qphy->regs)
+
+enum vdd_levels {
+	VDD_LEVEL_NONE = 0,
+	VDD_LEVEL_MIN,
+	VDD_LEVEL_MAX,
+};
+
+struct phy_hsic {
+	struct usb_phy			phy;
+	void __iomem			*regs;
+	struct clk			*core_clk;
+	struct clk			*alt_core_clk;
+	struct clk			*phy_clk;
+	struct clk			*cal_clk;
+	struct clk			*iface_clk;
+	struct regulator		*vdd;
+
+	struct reset_control		*link_reset;
+
+	int vdd_levels[3];
+
+	struct usb_bus			*host;
+
+	struct regmap			*tlmm;
+	u32				tlmm_cfg[4];
+
+	int				hsic_gpios[2];
+	bool				hsic_gpios_en;
+};
+
+static int ulpi_read(struct usb_phy *phy, u32 reg)
+{
+	struct phy_hsic *qphy = container_of(phy, struct phy_hsic, phy);
+	int cnt = 0;
+
+	/* initiate read operation */
+	writel(ULPI_RUN | ULPI_READ | ULPI_ADDR(reg),
+	       USB_ULPI_VIEWPORT);
+
+	/* wait for completion */
+	while (cnt < ULPI_IO_TIMEOUT_USEC) {
+		if (!(readl(USB_ULPI_VIEWPORT) & ULPI_RUN))
+			break;
+		udelay(1);
+		cnt++;
+	}
+
+	if (cnt >= ULPI_IO_TIMEOUT_USEC) {
+		dev_err(phy->dev, "ulpi_read: timeout %08x\n",
+			readl(USB_ULPI_VIEWPORT));
+		return -ETIMEDOUT;
+	}
+	return ULPI_DATA_READ(readl(USB_ULPI_VIEWPORT));
+}
+
+static int ulpi_write(struct usb_phy *phy, u32 val, u32 reg)
+{
+	struct phy_hsic *qphy = container_of(phy, struct phy_hsic, phy);
+	int cnt = 0;
+
+	/* initiate write operation */
+	writel(ULPI_RUN | ULPI_WRITE |
+	       ULPI_ADDR(reg) | ULPI_DATA(val),
+	       USB_ULPI_VIEWPORT);
+
+	/* wait for completion */
+	while (cnt < ULPI_IO_TIMEOUT_USEC) {
+		if (!(readl(USB_ULPI_VIEWPORT) & ULPI_RUN))
+			break;
+		udelay(1);
+		cnt++;
+	}
+
+	if (cnt >= ULPI_IO_TIMEOUT_USEC) {
+		dev_err(phy->dev, "ulpi_write: timeout\n");
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+static struct usb_phy_io_ops qcom_hsic_io_ops = {
+	.read = ulpi_read,
+	.write = ulpi_write,
+};
+
+static int phy_hsic_regulators_enable(struct phy_hsic *qphy)
+{
+	int ret;
+
+	ret = regulator_set_voltage(qphy->vdd,
+				qphy->vdd_levels[VDD_LEVEL_MIN],
+				qphy->vdd_levels[VDD_LEVEL_MAX]);
+	if (ret)
+		return ret;
+
+	ret = regulator_enable(qphy->vdd);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void phy_hsic_regulators_disable(struct phy_hsic *qphy)
+{
+	regulator_disable(qphy->vdd);
+}
+
+static int phy_hsic_clock_reset(struct phy_hsic *qphy)
+{
+	/* Reset sequence */
+	if (!IS_ERR(qphy->link_reset))
+		reset_control_assert(qphy->link_reset);
+
+	clk_disable(qphy->core_clk);
+	clk_disable(qphy->alt_core_clk);
+
+	if (!IS_ERR(qphy->link_reset))
+		reset_control_deassert(qphy->link_reset);
+
+	usleep_range(10000, 12000);
+
+	clk_enable(qphy->core_clk);
+	clk_enable(qphy->alt_core_clk);
+
+	return 0;
+}
+
+static int phy_hsic_reset(struct phy_hsic *qphy)
+{
+	phy_hsic_clock_reset(qphy);
+
+	/* select ULPI phy and clear other status/control bits in PORTSC */
+	writel_relaxed(0x80000000, USB_PORTSC);
+
+	/* Be sure PORTSC is written */
+	mb();
+
+	if (qphy->tlmm &&
+	    qphy->hsic_gpios[0] > 0 &&
+	    qphy->hsic_gpios[1] > 0) {
+
+		/* Enable LV_MODE in HSIC_CAL_PAD_CTL register */
+		regmap_write(qphy->tlmm, HSIC_CAL_PAD_CTL, HSIC_LV_MODE);
+
+		/* Be sure register is written */
+		mb();
+
+		/* set periodic calibration interval to ~2.048sec */
+		ulpi_write(&qphy->phy, 0xFF, HSIC_IO_CAL_PER_REG);
+
+		/* Enable periodic IO calibration in HSIC_CFG register */
+		ulpi_write(&qphy->phy, 0xA8, HSIC_CFG_REG);
+
+		/* Configure GPIO pins for HSIC functionality mode */
+		if (!qphy->hsic_gpios_en) {
+			gpio_request(qphy->hsic_gpios[0], "HSIC_GPIO0");
+			gpio_request(qphy->hsic_gpios[1], "HSIC_GPIO1");
+			qphy->hsic_gpios_en = true;
+		}
+
+		/* Set LV_MODE=0x1 and DCC=0x2 in HSIC_GPIO PAD_CTL register */
+		regmap_write(qphy->tlmm, qphy->tlmm_cfg[0],
+					 qphy->tlmm_cfg[1]);
+		regmap_write(qphy->tlmm, qphy->tlmm_cfg[2],
+					 qphy->tlmm_cfg[3]);
+
+		/* Enable HSIC mode in HSIC_CFG register */
+		ulpi_write(&qphy->phy, 0x01, HSIC_CFG1_REG);
+
+	} else {
+		/* Setup HSIC pads */
+		if (qphy->tlmm) {
+			regmap_write(qphy->tlmm, qphy->tlmm_cfg[0],
+						 qphy->tlmm_cfg[1]);
+			regmap_write(qphy->tlmm, qphy->tlmm_cfg[2],
+						 qphy->tlmm_cfg[3]);
+		}
+
+		/* programmable length of connect signaling (33.2ns) */
+		ulpi_write(&qphy->phy, 3, HSIC_DBG1_REG);
+
+		/* set periodic calibration interval to ~2.048sec */
+		ulpi_write(&qphy->phy, 0xFF, HSIC_IO_CAL_PER_REG);
+
+		/* Enable HSIC mode in HSIC_CFG register */
+		ulpi_write(&qphy->phy, 0xA9, HSIC_CFG_REG);
+	}
+
+	/* Disable auto resume */
+	ulpi_write(&qphy->phy, ULPI_IFC_CTRL_AUTORESUME,
+			ULPI_CLR(ULPI_IFC_CTRL));
+
+	return 0;
+};
+
+static int phy_hsic_init(struct usb_phy *phy)
+{
+	struct phy_hsic *qphy = container_of(phy, struct phy_hsic, phy);
+
+	/* bursts of unspecified length. */
+	writel_relaxed(0, USB_AHBBURST);
+
+	/* Use the AHB transactor */
+	writel_relaxed(0x08, USB_AHBMODE);
+
+	/* Disable streaming mode and select host mode */
+	writel_relaxed(0x13, USB_USBMODE);
+
+	return 0;
+}
+
+static int phy_hsic_set_host(struct usb_otg *otg, struct usb_bus *host)
+{
+	struct phy_hsic *qphy =
+		container_of(otg->usb_phy, struct phy_hsic, phy);
+	struct usb_hcd *hcd;
+
+	dev_info(otg->usb_phy->dev, "%s()\n", __func__);
+
+	if (!host) {
+		if (!qphy->host)
+			return -EINVAL;
+
+		hcd = bus_to_hcd(host);
+
+		usb_remove_hcd(hcd);
+
+		qphy->host = NULL;
+
+		dev_dbg(otg->usb_phy->dev, "host off\n");
+
+	} else {
+		if (qphy->host) {
+			dev_err(otg->usb_phy->dev, "host already registered\n");
+			return -EFAULT;
+		}
+
+		phy_hsic_init(otg->usb_phy);
+
+		hcd = bus_to_hcd(host);
+
+		usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
+
+		device_wakeup_enable(hcd->self.controller);
+
+		dev_dbg(otg->usb_phy->dev, "host on\n");
+
+		qphy->host = host;
+	}
+
+	return 0;
+}
+
+static int phy_hsic_read_devicetree(struct phy_hsic *qphy)
+{
+	struct regulator_bulk_data regs[1];
+	struct device *dev = qphy->phy.dev;
+	u32 tmp[3];
+	int ret;
+	int len;
+
+	qphy->core_clk = devm_clk_get(dev, "core");
+	if (IS_ERR(qphy->core_clk))
+		return PTR_ERR(qphy->core_clk);
+
+	qphy->alt_core_clk = devm_clk_get(dev, "alt-core");
+	if (IS_ERR(qphy->alt_core_clk))
+		return PTR_ERR(qphy->alt_core_clk);
+
+	qphy->phy_clk = devm_clk_get(dev, "phy");
+	if (IS_ERR(qphy->phy_clk))
+		return PTR_ERR(qphy->phy_clk);
+
+	qphy->cal_clk = devm_clk_get(dev, "cal");
+	if (IS_ERR(qphy->cal_clk))
+		return PTR_ERR(qphy->cal_clk);
+
+	qphy->iface_clk = devm_clk_get(dev, "iface");
+	if (IS_ERR(qphy->iface_clk))
+		return PTR_ERR(qphy->iface_clk);
+
+	regs[0].supply = "vddcx";
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(regs), regs);
+	if (ret)
+		return ret;
+
+	qphy->vdd  = regs[0].consumer;
+
+	qphy->vdd_levels[VDD_LEVEL_NONE] = USB_PHY_SUSP_DIG_VOL;
+	qphy->vdd_levels[VDD_LEVEL_MIN] = USB_PHY_VDD_DIG_VOL_MIN;
+	qphy->vdd_levels[VDD_LEVEL_MAX] = USB_PHY_VDD_DIG_VOL_MAX;
+
+	if (of_get_property(dev->of_node, "qcom,vdd-levels", &len) &&
+	    len == sizeof(tmp)) {
+		of_property_read_u32_array(dev->of_node, "qcom,vdd-levels",
+					   tmp, len / sizeof(*tmp));
+		qphy->vdd_levels[VDD_LEVEL_NONE] = tmp[VDD_LEVEL_NONE];
+		qphy->vdd_levels[VDD_LEVEL_MIN] = tmp[VDD_LEVEL_MIN];
+		qphy->vdd_levels[VDD_LEVEL_MAX] = tmp[VDD_LEVEL_MAX];
+	}
+
+	qphy->link_reset = devm_reset_control_get(dev, "link");
+	if (IS_ERR(qphy->link_reset))
+		return PTR_ERR(qphy->link_reset);
+
+	qphy->tlmm = syscon_regmap_lookup_by_phandle(dev->of_node,
+						     "qcom,tlmm");
+	if (!IS_ERR(qphy->tlmm) &&
+	    of_get_property(dev->of_node, "qcom,tlmm-cfg", &len) &&
+	    len == (4 * sizeof(u32))) {
+		of_property_read_u32_array(dev->of_node, "qcom,tlmm-cfg",
+					   qphy->tlmm_cfg, 4);
+		dev_info(dev, "got tlmm hsic pad cfg\n");
+
+		if (of_gpio_named_count(dev->of_node,
+					"qcom,hsic-gpios") == 2) {
+			qphy->hsic_gpios[0] = of_get_named_gpio(dev->of_node,
+							"qcom,hsic-gpios", 0);
+			qphy->hsic_gpios[1] = of_get_named_gpio(dev->of_node,
+							"qcom,hsic-gpios", 1);
+		}
+	} else
+		qphy->tlmm = NULL;
+
+	return 0;
+}
+
+static int phy_hsic_probe(struct platform_device *pdev)
+{
+	struct phy_hsic *qphy;
+	struct resource *res;
+	struct usb_phy *phy;
+	int ret;
+
+	qphy = devm_kzalloc(&pdev->dev, sizeof(*qphy), GFP_KERNEL);
+	if (!qphy)
+		return -ENOMEM;
+
+	qphy->phy.otg = devm_kzalloc(&pdev->dev, sizeof(struct usb_otg),
+				     GFP_KERNEL);
+	if (!qphy->phy.otg)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, qphy);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	qphy->regs = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!qphy->regs)
+		return -ENOMEM;
+
+	phy			= &qphy->phy;
+	phy->dev		= &pdev->dev;
+	phy->label		= dev_name(&pdev->dev);
+	phy->io_ops		= &qcom_hsic_io_ops;
+	phy->type		= USB_PHY_TYPE_USB2;
+	phy->init		= phy_hsic_init;
+
+	phy->otg->usb_phy	= phy;
+	phy->otg->set_host	= phy_hsic_set_host;
+
+	ret = phy_hsic_read_devicetree(qphy);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_prepare_enable(qphy->core_clk);
+	if (ret < 0)
+		return ret;
+
+	ret = clk_prepare_enable(qphy->phy_clk);
+	if (ret < 0)
+		goto off_alt;
+
+	ret = clk_prepare_enable(qphy->cal_clk);
+	if (ret < 0)
+		goto off_phy;
+
+	ret = clk_prepare_enable(qphy->iface_clk);
+	if (ret < 0)
+		goto off_cal;
+
+	ret = clk_prepare_enable(qphy->alt_core_clk);
+	if (ret < 0)
+		goto off_core;
+
+	ret = phy_hsic_regulators_enable(qphy);
+	if (ret)
+		goto off_clks;
+
+	ret = phy_hsic_reset(qphy);
+	if (ret)
+		goto off_clks;
+
+	ret = usb_add_phy_dev(&qphy->phy);
+	if (ret)
+		goto off_power;
+
+	return 0;
+
+off_power:
+	phy_hsic_regulators_disable(qphy);
+off_clks:
+	clk_disable_unprepare(qphy->iface_clk);
+off_cal:
+	clk_disable_unprepare(qphy->cal_clk);
+off_phy:
+	clk_disable_unprepare(qphy->phy_clk);
+off_alt:
+	clk_disable_unprepare(qphy->alt_core_clk);
+off_core:
+	clk_disable_unprepare(qphy->core_clk);
+	return ret;
+}
+
+static int phy_hsic_remove(struct platform_device *pdev)
+{
+	struct phy_hsic *qphy = platform_get_drvdata(pdev);
+
+	usb_remove_phy(&qphy->phy);
+
+	clk_disable_unprepare(qphy->iface_clk);
+	clk_disable_unprepare(qphy->cal_clk);
+	clk_disable_unprepare(qphy->phy_clk);
+	clk_disable_unprepare(qphy->alt_core_clk);
+	clk_disable_unprepare(qphy->core_clk);
+	phy_hsic_regulators_disable(qphy);
+	return 0;
+}
+
+static const struct of_device_id phy_hsic_dt_match[] = {
+	{ .compatible = "qcom,usb-hsic-phy" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, phy_hsic_dt_match);
+
+static struct platform_driver phy_hsic_driver = {
+	.probe	= phy_hsic_probe,
+	.remove = phy_hsic_remove,
+	.driver = {
+		.name = "phy-qcom-hsic-usb",
+		.of_match_table = phy_hsic_dt_match,
+	},
+};
+module_platform_driver(phy_hsic_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Qualcomm HSIC USB transceiver driver");
-- 
1.9.1

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