[PATCH v6 2/3] phy:phy-bcm-ns2-usbdrd:Broadcom USB DRD Phy driver for Northstar2

[Raviteja Garimella]

This is driver for USB DRD Phy used in Broadcom's Northstar2
SoC. The phy can be configured to be in Device mode or Host
mode based on the type of cable connected to the port. The
driver registers to  extcon framework to get appropriate
connect events for Host/Device cables connect/disconnect
states based on VBUS and ID interrupts.

Signed-off-by: Raviteja Garimella <raviteja.garimella@xxxxxxxxxxxx>
---
 drivers/phy/Kconfig              |  13 ++
 drivers/phy/Makefile             |   1 +
 drivers/phy/phy-bcm-ns2-usbdrd.c | 466 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 480 insertions(+)
 create mode 100644 drivers/phy/phy-bcm-ns2-usbdrd.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index afaf7b6..8028da7 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -507,6 +507,19 @@ config PHY_CYGNUS_PCIE
 	  Enable this to support the Broadcom Cygnus PCIe PHY.
 	  If unsure, say N.
 
+config PHY_NS2_USB_DRD
+	tristate "Broadcom Northstar2 USB DRD PHY support"
+	depends on OF && (ARCH_BCM_IPROC || COMPILE_TEST)
+	select GENERIC_PHY
+	select EXTCON
+	default ARCH_BCM_IPROC
+	help
+	  Enable this to support the Broadcom Northstar2 USB DRD PHY.
+	  This driver initializes the PHY in either HOST or DEVICE mode.
+	  The host or device configuration is read from device tree.
+
+	  If unsure, say N.
+
 source "drivers/phy/tegra/Kconfig"
 
 config PHY_NS2_PCIE
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index f8047b4..e5fbb0e 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_PHY_TUSB1210)		+= phy-tusb1210.o
 obj-$(CONFIG_PHY_BRCM_SATA)		+= phy-brcm-sata.o
 obj-$(CONFIG_PHY_PISTACHIO_USB)		+= phy-pistachio-usb.o
 obj-$(CONFIG_PHY_CYGNUS_PCIE)		+= phy-bcm-cygnus-pcie.o
+obj-$(CONFIG_PHY_NS2_USB_DRD)		+= phy-bcm-ns2-usbdrd.o
 obj-$(CONFIG_ARCH_TEGRA) += tegra/
 obj-$(CONFIG_PHY_NS2_PCIE)		+= phy-bcm-ns2-pcie.o
 obj-$(CONFIG_PHY_MESON8B_USB2)		+= phy-meson8b-usb2.o
diff --git a/drivers/phy/phy-bcm-ns2-usbdrd.c b/drivers/phy/phy-bcm-ns2-usbdrd.c
new file mode 100644
index 0000000..8e05c70
--- /dev/null
+++ b/drivers/phy/phy-bcm-ns2-usbdrd.c
@@ -0,0 +1,466 @@
+/*
+ * Copyright (C) 2017 Broadcom
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/extcon.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+#include <linux/workqueue.h>
+
+#define ICFG_DRD_AFE		0x0
+#define ICFG_MISC_STAT		0x18
+#define ICFG_DRD_P0CTL		0x1C
+#define ICFG_STRAP_CTRL		0x20
+#define ICFG_FSM_CTRL		0x24
+
+#define ICFG_DEV_BIT		BIT(2)
+#define IDM_RST_BIT		BIT(0)
+#define AFE_CORERDY_VDDC	BIT(18)
+#define PHY_PLL_RESETB		BIT(15)
+#define PHY_RESETB		BIT(14)
+#define PHY_PLL_LOCK		BIT(0)
+
+#define DRD_DEV_MODE		BIT(20)
+#define OHCI_OVRCUR_POL		BIT(11)
+#define ICFG_OFF_MODE		BIT(6)
+#define PLL_LOCK_RETRY		1000
+
+#define EVT_DEVICE		0
+#define EVT_HOST		1
+
+#define DRD_HOST_MODE		(BIT(2) | BIT(3))
+#define DRD_DEVICE_MODE		(BIT(4) | BIT(5))
+#define DRD_HOST_VAL		0x803
+#define DRD_DEV_VAL		0x807
+#define GPIO_DELAY		20
+
+struct ns2_phy_data;
+struct ns2_phy_driver {
+	void __iomem *icfgdrd_regs;
+	void __iomem *idmdrd_rst_ctrl;
+	void __iomem *crmu_usb2_ctrl;
+	void __iomem *usb2h_strap_reg;
+	struct ns2_phy_data *data;
+	struct extcon_specific_cable_nb extcon_dev;
+	struct extcon_specific_cable_nb extcon_host;
+	struct extcon_dev *edev;
+	struct gpio_desc *vbus_gpiod;
+	struct gpio_desc *id_gpiod;
+	int id_irq;
+	int vbus_irq;
+	unsigned long debounce_jiffies;
+	struct delayed_work wq_extcon;
+};
+
+struct ns2_phy_data {
+	struct ns2_phy_driver *driver;
+	struct phy *phy;
+	int new_state;
+};
+
+static const unsigned int usb_extcon_cable[] = {
+	EXTCON_USB,
+	EXTCON_USB_HOST,
+	EXTCON_NONE,
+};
+
+static inline int pll_lock_stat(u32 usb_reg, int reg_mask,
+				struct ns2_phy_driver *driver)
+{
+	int retry = PLL_LOCK_RETRY;
+	u32 val;
+
+	do {
+		udelay(1);
+		val = readl(driver->icfgdrd_regs + usb_reg);
+		if (val & reg_mask)
+			return 0;
+	} while (--retry > 0);
+
+	return -EBUSY;
+}
+
+static int ns2_drd_phy_init(struct phy *phy)
+{
+	struct ns2_phy_data *data = phy_get_drvdata(phy);
+	struct ns2_phy_driver *driver = data->driver;
+	u32 val;
+
+	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+	if (data->new_state == EVT_HOST) {
+		val &= ~DRD_DEVICE_MODE;
+		val |= DRD_HOST_MODE;
+	} else {
+		val &= ~DRD_HOST_MODE;
+		val |= DRD_DEVICE_MODE;
+	}
+	writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+	return 0;
+}
+
+static int ns2_drd_phy_shutdown(struct phy *phy)
+{
+	struct ns2_phy_data *data = phy_get_drvdata(phy);
+	struct ns2_phy_driver *driver = data->driver;
+	u32 val;
+
+	val = readl(driver->crmu_usb2_ctrl);
+	val &= ~AFE_CORERDY_VDDC;
+	writel(val, driver->crmu_usb2_ctrl);
+
+	val = readl(driver->crmu_usb2_ctrl);
+	val &= ~DRD_DEV_MODE;
+	writel(val, driver->crmu_usb2_ctrl);
+
+	/* Disable Host and Device Mode */
+	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
+	val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE | ICFG_OFF_MODE);
+	writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+	return 0;
+}
+
+static int ns2_drd_phy_poweron(struct phy *phy)
+{
+	struct ns2_phy_data *data = phy_get_drvdata(phy);
+	struct ns2_phy_driver *driver = data->driver;
+	u32 extcon_event = data->new_state;
+	int ret;
+	u32 val;
+
+	if (extcon_event == EVT_DEVICE) {
+		writel(DRD_DEV_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
+
+		val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
+		val &= ~(DRD_HOST_MODE | ICFG_OFF_MODE);
+		val |= DRD_DEVICE_MODE;
+		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+		val = readl(driver->idmdrd_rst_ctrl);
+		val &= ~IDM_RST_BIT;
+		writel(val, driver->idmdrd_rst_ctrl);
+
+		val = readl(driver->crmu_usb2_ctrl);
+		val |= (AFE_CORERDY_VDDC | DRD_DEV_MODE);
+		writel(val, driver->crmu_usb2_ctrl);
+
+		/* Bring PHY and PHY_PLL out of Reset */
+		val = readl(driver->crmu_usb2_ctrl);
+		val |= (PHY_PLL_RESETB | PHY_RESETB);
+		writel(val, driver->crmu_usb2_ctrl);
+
+		ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
+		if (ret < 0) {
+			dev_err(&phy->dev, "Phy PLL lock failed\n");
+			goto err_shutdown;
+		}
+	} else {
+		writel(DRD_HOST_VAL, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
+
+		val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
+		val &= ~(DRD_DEVICE_MODE | ICFG_OFF_MODE);
+		val |= DRD_HOST_MODE;
+		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+		val = readl(driver->crmu_usb2_ctrl);
+		val |= AFE_CORERDY_VDDC;
+		writel(val, driver->crmu_usb2_ctrl);
+
+		ret = pll_lock_stat(ICFG_MISC_STAT, PHY_PLL_LOCK, driver);
+		if (ret < 0) {
+			dev_err(&phy->dev, "Phy PLL lock failed\n");
+			goto err_shutdown;
+		}
+
+		val = readl(driver->idmdrd_rst_ctrl);
+		val &= ~IDM_RST_BIT;
+		writel(val, driver->idmdrd_rst_ctrl);
+
+		/* port over current Polarity */
+		val = readl(driver->usb2h_strap_reg);
+		val |= OHCI_OVRCUR_POL;
+		writel(val, driver->usb2h_strap_reg);
+	}
+
+	return 0;
+
+err_shutdown:
+	ns2_drd_phy_shutdown(phy);
+	return ret;
+}
+
+static void connect_change(struct ns2_phy_driver *driver)
+{
+	u32 extcon_event;
+	u32 val;
+
+	extcon_event = driver->data->new_state;
+	val = readl(driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+	switch (extcon_event) {
+	case EVT_DEVICE:
+		val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
+		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+		val = (val & ~DRD_HOST_MODE) | DRD_DEVICE_MODE;
+		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+		val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
+		val |= ICFG_DEV_BIT;
+		writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
+		break;
+
+	case EVT_HOST:
+		val &= ~(DRD_HOST_MODE | DRD_DEVICE_MODE);
+		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+		val = (val & ~DRD_DEVICE_MODE) | DRD_HOST_MODE;
+		writel(val, driver->icfgdrd_regs + ICFG_FSM_CTRL);
+
+		val = readl(driver->usb2h_strap_reg);
+		val |= OHCI_OVRCUR_POL;
+		writel(val, driver->usb2h_strap_reg);
+
+		val = readl(driver->icfgdrd_regs + ICFG_DRD_P0CTL);
+		val &= ~ICFG_DEV_BIT;
+		writel(val, driver->icfgdrd_regs + ICFG_DRD_P0CTL);
+		break;
+
+	default:
+		pr_err("Invalid extcon event\n");
+		break;
+	}
+}
+
+static void extcon_work(struct work_struct *work)
+{
+	struct ns2_phy_driver *driver;
+	int vbus;
+	int id;
+
+	driver  = container_of(to_delayed_work(work),
+			       struct ns2_phy_driver, wq_extcon);
+
+	id = gpiod_get_value_cansleep(driver->id_gpiod);
+	vbus = gpiod_get_value_cansleep(driver->vbus_gpiod);
+
+	if (!id && vbus) { /* Host connected */
+		extcon_set_cable_state_(driver->edev, EXTCON_USB_HOST, true);
+		pr_debug("Host cable connected\n");
+		driver->data->new_state = EVT_HOST;
+		connect_change(driver);
+	} else if (id && !vbus) { /* Disconnected */
+		extcon_set_cable_state_(driver->edev, EXTCON_USB_HOST, false);
+		extcon_set_cable_state_(driver->edev, EXTCON_USB, false);
+		pr_debug("Cable disconnected\n");
+	} else if (id && vbus) { /* Device connected */
+		extcon_set_cable_state_(driver->edev, EXTCON_USB, true);
+		pr_debug("Device cable connected\n");
+		driver->data->new_state = EVT_DEVICE;
+		connect_change(driver);
+	}
+}
+
+static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
+{
+	struct ns2_phy_driver *driver = dev_id;
+
+	queue_delayed_work(system_power_efficient_wq, &driver->wq_extcon,
+			   driver->debounce_jiffies);
+
+	return IRQ_HANDLED;
+}
+
+static struct phy_ops ops = {
+	.init		= ns2_drd_phy_init,
+	.power_on	= ns2_drd_phy_poweron,
+	.power_off	= ns2_drd_phy_shutdown,
+	.owner		= THIS_MODULE,
+};
+
+static const struct of_device_id ns2_drd_phy_dt_ids[] = {
+	{ .compatible = "brcm,ns2-drd-phy", },
+	{ }
+};
+
+static int ns2_drd_phy_probe(struct platform_device *pdev)
+{
+	struct phy_provider *phy_provider;
+	struct device *dev = &pdev->dev;
+	struct ns2_phy_driver *driver;
+	struct ns2_phy_data *data;
+	struct resource *res;
+	int ret;
+	u32 val;
+
+	driver = devm_kzalloc(dev, sizeof(struct ns2_phy_driver),
+			      GFP_KERNEL);
+	if (!driver)
+		return -ENOMEM;
+
+	driver->data = devm_kzalloc(dev, sizeof(struct ns2_phy_data),
+				  GFP_KERNEL);
+	if (!driver->data)
+		return -ENOMEM;
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "icfg");
+	driver->icfgdrd_regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(driver->icfgdrd_regs))
+		return PTR_ERR(driver->icfgdrd_regs);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rst-ctrl");
+	driver->idmdrd_rst_ctrl = devm_ioremap_resource(dev, res);
+	if (IS_ERR(driver->idmdrd_rst_ctrl))
+		return PTR_ERR(driver->idmdrd_rst_ctrl);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "crmu-ctrl");
+	driver->crmu_usb2_ctrl = devm_ioremap_resource(dev, res);
+	if (IS_ERR(driver->crmu_usb2_ctrl))
+		return PTR_ERR(driver->crmu_usb2_ctrl);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "usb2-strap");
+	driver->usb2h_strap_reg = devm_ioremap_resource(dev, res);
+	if (IS_ERR(driver->usb2h_strap_reg))
+		return PTR_ERR(driver->usb2h_strap_reg);
+
+	 /* create extcon */
+	driver->id_gpiod = devm_gpiod_get(&pdev->dev, "id", GPIOD_IN);
+	if (IS_ERR(driver->id_gpiod)) {
+		dev_err(dev, "failed to get ID GPIO\n");
+		return PTR_ERR(driver->id_gpiod);
+	}
+	driver->vbus_gpiod = devm_gpiod_get(&pdev->dev, "vbus", GPIOD_IN);
+	if (IS_ERR(driver->vbus_gpiod)) {
+		dev_err(dev, "failed to get VBUS GPIO\n");
+		return PTR_ERR(driver->vbus_gpiod);
+	}
+
+	driver->edev = devm_extcon_dev_allocate(dev, usb_extcon_cable);
+	if (IS_ERR(driver->edev)) {
+		dev_err(dev, "failed to allocate extcon device\n");
+		return -ENOMEM;
+	}
+
+	ret = devm_extcon_dev_register(dev, driver->edev);
+	if (ret < 0) {
+		dev_err(dev, "failed to register extcon device\n");
+		goto extcon_free;
+	}
+
+	ret = gpiod_set_debounce(driver->id_gpiod, GPIO_DELAY * 1000);
+	if (ret < 0)
+		driver->debounce_jiffies = msecs_to_jiffies(GPIO_DELAY);
+
+	INIT_DELAYED_WORK(&driver->wq_extcon, extcon_work);
+
+	driver->id_irq = gpiod_to_irq(driver->id_gpiod);
+	if (driver->id_irq < 0) {
+		dev_err(dev, "failed to get ID IRQ\n");
+		ret = driver->id_irq;
+		goto extcon_unregister;
+	}
+	driver->vbus_irq = gpiod_to_irq(driver->vbus_gpiod);
+	if (driver->vbus_irq < 0) {
+		dev_err(dev, "failed to get ID IRQ\n");
+		ret = driver->vbus_irq;
+		goto extcon_unregister;
+	}
+
+	ret = devm_request_threaded_irq(dev, driver->id_irq, NULL,
+					gpio_irq_handler,
+					IRQF_TRIGGER_RISING |
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					"usb_id", driver);
+	if (ret < 0) {
+		dev_err(dev, "failed to request handler for ID IRQ\n");
+		goto extcon_unregister;
+	}
+	ret = devm_request_threaded_irq(dev, driver->vbus_irq, NULL,
+					gpio_irq_handler,
+					IRQF_TRIGGER_RISING |
+					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
+					"usb_vbus", driver);
+	if (ret < 0) {
+		dev_err(dev, "failed to request handler for VBUS IRQ\n");
+		goto extcon_unregister;
+	}
+
+	dev_set_drvdata(dev, driver);
+
+	/* Shutdown all ports. They can be powered up as required */
+	val = readl(driver->crmu_usb2_ctrl);
+	val &= ~(AFE_CORERDY_VDDC | PHY_RESETB);
+	writel(val, driver->crmu_usb2_ctrl);
+
+	data = driver->data;
+	data->phy = devm_phy_create(dev, dev->of_node, &ops);
+	if (IS_ERR(data->phy)) {
+		dev_err(dev, "Failed to create usb drd phy\n");
+		ret = PTR_ERR(data->phy);
+		goto extcon_unregister;
+	}
+
+	data->driver = driver;
+	phy_set_drvdata(data->phy, data);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(phy_provider)) {
+		dev_err(dev, "Failed to register as phy provider\n");
+		ret = PTR_ERR(phy_provider);
+		goto extcon_unregister;
+	}
+
+	platform_set_drvdata(pdev, driver);
+
+	dev_info(dev, "Registered NS2 DRD Phy device\n");
+	queue_delayed_work(system_power_efficient_wq, &driver->wq_extcon,
+			   driver->debounce_jiffies);
+
+	return 0;
+
+extcon_unregister:
+	devm_extcon_dev_unregister(dev, driver->edev);
+extcon_free:
+	devm_extcon_dev_free(dev, driver->edev);
+	return ret;
+}
+
+MODULE_DEVICE_TABLE(of, ns2_drd_phy_dt_ids);
+
+static struct platform_driver ns2_drd_phy_driver = {
+	.probe = ns2_drd_phy_probe,
+	.driver = {
+		.name = "bcm-ns2-usbphy",
+		.of_match_table = of_match_ptr(ns2_drd_phy_dt_ids),
+	},
+};
+module_platform_driver(ns2_drd_phy_driver);
+
+MODULE_ALIAS("platform:bcm-ns2-drd-phy");
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("Broadcom NS2 USB2 PHY driver");
+MODULE_LICENSE("GPL v2");
-- 
2.1.0