[PATCH v3 3/3] phy: cygnus-usbphy: Add Broadcom Cygnus USB phy driver

[Arun Ramamurthy]

This driver adds support for USB 2.0 host and device phy for
Broadcom's Cygnus chipset. The host controller is connected to
three separate phys and one of the phys (port 2) is connected to
the device controller

Signed-off-by: Arun Ramamurthy <arun.ramamurthy@xxxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dtor@xxxxxxxxxxxx>
Reviewed-by: Ray Jui <rjui@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
---
 drivers/phy/Kconfig              |  12 +
 drivers/phy/Makefile             |   1 +
 drivers/phy/phy-bcm-cygnus-usb.c | 504 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 517 insertions(+)
 create mode 100644 drivers/phy/phy-bcm-cygnus-usb.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 2962de2..0aa62dc 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -291,4 +291,16 @@ config PHY_QCOM_UFS
 	help
 	  Support for UFS PHY on QCOM chipsets.
 
+config PHY_BCM_CYGNUS_USB
+	tristate "Broadcom Cygnus USB PHY support"
+	depends on OF
+	depends on ARCH_BCM_CYGNUS || COMPILE_TEST
+	select GENERIC_PHY
+	default ARCH_BCM_CYGNUS
+	help
+	  Enable this to support the USB PHY in Broadcom's Cygnus chip.
+	  The phys are capable of supporting host mode for all ports
+	  and device mode for port 2. The host or device configuration is
+	  read from the device tree.
+
 endmenu
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index f080e1b..47a37fa 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_GENERIC_PHY)		+= phy-core.o
 obj-$(CONFIG_PHY_BERLIN_USB)		+= phy-berlin-usb.o
 obj-$(CONFIG_PHY_BERLIN_SATA)		+= phy-berlin-sata.o
 obj-$(CONFIG_ARMADA375_USBCLUSTER_PHY)	+= phy-armada375-usb2.o
+obj-$(CONFIG_PHY_BCM_CYGNUS_USB)	+= phy-bcm-cygnus-usb.o
 obj-$(CONFIG_BCM_KONA_USB2_PHY)		+= phy-bcm-kona-usb2.o
 obj-$(CONFIG_PHY_EXYNOS_DP_VIDEO)	+= phy-exynos-dp-video.o
 obj-$(CONFIG_PHY_EXYNOS_MIPI_VIDEO)	+= phy-exynos-mipi-video.o
diff --git a/drivers/phy/phy-bcm-cygnus-usb.c b/drivers/phy/phy-bcm-cygnus-usb.c
new file mode 100644
index 0000000..e718404
--- /dev/null
+++ b/drivers/phy/phy-bcm-cygnus-usb.c
@@ -0,0 +1,504 @@
+/*
+ * Copyright (C) 2015 Broadcom Corporation
+ *
+ * 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/delay.h>
+
+#define CDRU_USBPHY_CLK_RST_SEL_OFFSET			0x11b4
+#define CDRU_USBPHY2_HOST_DEV_SEL_OFFSET		0x11b8
+#define CDRU_SPARE_REG_0_OFFSET				0x1238
+#define CRMU_USB_PHY_AON_CTRL_OFFSET			0x00028
+#define CDRU_USB_DEV_SUSPEND_RESUME_CTRL_OFFSET		0x1210
+#define CDRU_USBPHY_P0_STATUS_OFFSET			0x11D0
+#define CDRU_USBPHY_P1_STATUS_OFFSET			0x11E8
+#define CDRU_USBPHY_P2_STATUS_OFFSET			0x1200
+#define CDRU_USBPHY_USBPHY_ILDO_ON_FLAG			1
+#define CDRU_USBPHY_USBPHY_PLL_LOCK			0
+#define CDRU_USB_DEV_SUSPEND_RESUME_CTRL_DISABLE	0
+#define PHY2_DEV_HOST_CTRL_SEL_HOST			1
+
+#define CRMU_USBPHY_P0_AFE_CORERDY_VDDC			1
+#define CRMU_USBPHY_P0_RESETB				2
+#define CRMU_USBPHY_P1_AFE_CORERDY_VDDC			9
+#define CRMU_USBPHY_P1_RESETB				10
+#define CRMU_USBPHY_P2_AFE_CORERDY_VDDC			17
+#define CRMU_USBPHY_P2_RESETB				18
+
+#define USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET		0x0408
+#define USB2_IDM_IDM_IO_CONTROL_DIRECT__clk_enable	0
+#define USB2_IDM_IDM_RESET_CONTROL_OFFSET		0x0800
+#define USB2_IDM_IDM_RESET_CONTROL__RESET		0
+
+#define PLL_LOCK_RETRY_COUNT	1000
+#define MAX_PHY_PORTS		3
+
+static int power_bit[] = {CRMU_USBPHY_P0_AFE_CORERDY_VDDC,
+				CRMU_USBPHY_P1_AFE_CORERDY_VDDC,
+				CRMU_USBPHY_P2_AFE_CORERDY_VDDC};
+static int reset_bit[] = {CRMU_USBPHY_P0_RESETB,
+				CRMU_USBPHY_P1_RESETB,
+				CRMU_USBPHY_P2_RESETB};
+static int status_reg[] = {CDRU_USBPHY_P0_STATUS_OFFSET,
+				CDRU_USBPHY_P1_STATUS_OFFSET,
+				CDRU_USBPHY_P2_STATUS_OFFSET};
+
+struct bcm_phy_instance;
+
+struct bcm_phy_driver {
+	void __iomem *usbphy_regs;
+	void __iomem *usb2h_idm_regs;
+	void __iomem *usb2d_idm_regs;
+	struct bcm_phy_instance *ports[MAX_PHY_PORTS];
+	spinlock_t lock;
+	bool idm_host_enabled;
+};
+
+struct bcm_phy_instance {
+	struct bcm_phy_driver *driver;
+	struct phy *generic_phy;
+	int port_no;
+	bool host_mode; /* true - Host, false - device */
+	bool power;
+};
+
+static inline int bcm_phy_cdru_usbphy_status_wait(u32 usb_reg, int reg_bit,
+					  struct bcm_phy_driver *phy_driver)
+{
+	/* Wait for the PLL lock status */
+	int retry = PLL_LOCK_RETRY_COUNT;
+	u32 reg_val;
+
+	do {
+		udelay(1);
+		reg_val = readl(phy_driver->usbphy_regs +
+				usb_reg);
+		if (reg_val & (1 << reg_bit))
+			return 0;
+	} while (--retry > 0);
+
+	return -EBUSY;
+
+}
+
+static struct phy *bcm_usb_phy_xlate(struct device *dev,
+				     struct of_phandle_args *args)
+{
+	struct bcm_phy_driver *phy_driver = dev_get_drvdata(dev);
+	struct bcm_phy_instance *port = NULL;
+	int i;
+
+	if (!phy_driver)
+		return ERR_PTR(-ENODEV);
+
+	if (WARN_ON(args->args_count != 1))
+		return ERR_PTR(-ENODEV);
+
+	if (WARN_ON(args->args[0] < 0 || args->args[0] > 1))
+		return ERR_PTR(-ENODEV);
+
+	for (i = 0; i < ARRAY_SIZE(phy_driver->ports); i++) {
+		struct bcm_phy_instance *p = phy_driver->ports[i];
+
+		if (p && p->generic_phy->dev.of_node == args->np) {
+			port = p;
+			break;
+		}
+	}
+
+	if (!port) {
+		dev_err(dev, "Failed to locate phy %s\n", args->np->name);
+		return ERR_PTR(-EINVAL);
+	}
+
+	port->host_mode = args->args[0];
+
+	return port->generic_phy;
+}
+
+static int bcm_phy_init(struct phy *generic_phy)
+{
+	struct bcm_phy_instance *port = phy_get_drvdata(generic_phy);
+	struct bcm_phy_driver *phy_driver = port->driver;
+	unsigned long flags;
+	u32 reg_val;
+
+	spin_lock_irqsave(&phy_driver->lock, flags);
+
+	/*
+	 * Only PORT 2 is capable of being device and host
+	 * Default setting is device, check if it is set to host.
+	 */
+	if (port->port_no != 2) {
+		spin_unlock_irqrestore(&phy_driver->lock, flags);
+		return 0;
+	}
+
+	if (port->host_mode) {
+		writel(PHY2_DEV_HOST_CTRL_SEL_HOST,
+			phy_driver->usbphy_regs +
+			CDRU_USBPHY2_HOST_DEV_SEL_OFFSET);
+	} else {
+		/*
+		 * Disable suspend/resume signals to device controller
+		 * when a port is in device mode.
+		 */
+		reg_val = readl(phy_driver->usbphy_regs +
+			      CDRU_USB_DEV_SUSPEND_RESUME_CTRL_OFFSET);
+		reg_val |=
+			1 << CDRU_USB_DEV_SUSPEND_RESUME_CTRL_DISABLE;
+		writel(reg_val, phy_driver->usbphy_regs +
+		       CDRU_USB_DEV_SUSPEND_RESUME_CTRL_OFFSET);
+	}
+
+
+	spin_unlock_irqrestore(&phy_driver->lock, flags);
+	return 0;
+}
+
+static int bcm_phy_shutdown(struct phy *generic_phy)
+{
+	struct bcm_phy_instance *port = phy_get_drvdata(generic_phy);
+	struct bcm_phy_driver *phy_driver = port->driver;
+	unsigned long flags;
+	int i;
+	u32 reg_val, powered_on_phy;
+	bool power_off_flag = true;
+
+	spin_lock_irqsave(&phy_driver->lock, flags);
+
+	/* power down the phy */
+	reg_val = readl(phy_driver->usbphy_regs +
+			CRMU_USB_PHY_AON_CTRL_OFFSET);
+	reg_val &= ~(1 << power_bit[port->port_no]);
+	reg_val &= ~(1 << reset_bit[port->port_no]);
+	writel(reg_val, phy_driver->usbphy_regs +
+		CRMU_USB_PHY_AON_CTRL_OFFSET);
+	port->power = false;
+
+	/*
+	 * If a port is configured to device and it is being shutdown,
+	 * turn off the clocks to the usb device controller.
+	 */
+	if (port->port_no == 2 && !port->host_mode) {
+		reg_val = readl(phy_driver->usb2d_idm_regs +
+				USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+		reg_val &= ~(1 << USB2_IDM_IDM_IO_CONTROL_DIRECT__clk_enable);
+		writel(reg_val, phy_driver->usb2d_idm_regs +
+				USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+
+		reg_val = readl(phy_driver->usb2d_idm_regs +
+				 USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+		reg_val |= 1 << USB2_IDM_IDM_RESET_CONTROL__RESET;
+		writel(reg_val, phy_driver->usb2d_idm_regs +
+				USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+
+		spin_unlock_irqrestore(&phy_driver->lock, flags);
+		return 0;
+	}
+
+	/*
+	 * If the phy being shutdown provides clock and reset to
+	 * the host controller, change it do a different powered on phy
+	 * If all phys are powered off, shut of the host controller
+	 */
+	reg_val = readl(phy_driver->usbphy_regs +
+			CDRU_USBPHY_CLK_RST_SEL_OFFSET);
+	powered_on_phy = reg_val;
+	if (reg_val == port->port_no) {
+		for (i = 0; i < ARRAY_SIZE(phy_driver->ports); i++) {
+			if (phy_driver->ports[i] &&
+			    phy_driver->ports[i]->power &&
+			    phy_driver->ports[i]->host_mode) {
+				power_off_flag = false;
+				powered_on_phy = i;
+				break;
+			}
+		}
+	}
+
+	if (power_off_flag) {
+		/*
+		 * Put the host controller into reset state and
+		 * disable clock.
+		 */
+		reg_val = readl(phy_driver->usb2h_idm_regs +
+			USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+		reg_val &=
+		  ~(1 << USB2_IDM_IDM_IO_CONTROL_DIRECT__clk_enable);
+		writel(reg_val, phy_driver->usb2h_idm_regs +
+				USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+
+		reg_val = readl(phy_driver->usb2h_idm_regs +
+				 USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+		reg_val |= (1 << USB2_IDM_IDM_RESET_CONTROL__RESET);
+		writel(reg_val, phy_driver->usb2h_idm_regs +
+				USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+		phy_driver->idm_host_enabled = 0;
+	} else {
+		writel(powered_on_phy, phy_driver->usbphy_regs +
+			   CDRU_USBPHY_CLK_RST_SEL_OFFSET);
+	}
+
+	spin_unlock_irqrestore(&phy_driver->lock, flags);
+
+	return 0;
+}
+
+static int bcm_phy_poweron(struct phy *generic_phy)
+{
+	struct bcm_phy_instance *port = phy_get_drvdata(generic_phy);
+	struct bcm_phy_driver *phy_driver = port->driver;
+	unsigned long flags;
+	int ret;
+	u32 reg_val;
+	bool clock_reset_flag = true;
+
+	spin_lock_irqsave(&phy_driver->lock, flags);
+
+	/* Bring the AFE block out of reset to start powering up the PHY */
+	reg_val = readl(phy_driver->usbphy_regs + CRMU_USB_PHY_AON_CTRL_OFFSET);
+	reg_val |= 1 << power_bit[port->port_no];
+	writel(reg_val, phy_driver->usbphy_regs + CRMU_USB_PHY_AON_CTRL_OFFSET);
+
+	/* Check for power on and PLL lock */
+	ret = bcm_phy_cdru_usbphy_status_wait(status_reg[port->port_no],
+		   CDRU_USBPHY_USBPHY_ILDO_ON_FLAG, phy_driver);
+	if (ret < 0) {
+		dev_err(&generic_phy->dev,
+			"Timed out waiting for USBPHY_ILDO_ON_FLAG on port %d",
+			port->port_no);
+		goto err_shutdown;
+	}
+	ret = bcm_phy_cdru_usbphy_status_wait(status_reg[port->port_no],
+		CDRU_USBPHY_USBPHY_PLL_LOCK, phy_driver);
+	if (ret < 0) {
+		dev_err(&generic_phy->dev,
+			"Timed out waiting for USBPHY_PLL_LOCK on port %d",
+			port->port_no);
+		goto err_shutdown;
+	}
+	port->power = true;
+
+	/* Check if the port 2 is configured for device */
+	if (port->port_no == 2 && !port->host_mode) {
+		/*
+		 * Enable clock to USB device and get the USB device
+		 * out of reset.
+		 */
+		reg_val = readl(phy_driver->usb2d_idm_regs +
+				USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+		reg_val |= 1 << USB2_IDM_IDM_IO_CONTROL_DIRECT__clk_enable;
+		writel(reg_val, phy_driver->usb2d_idm_regs +
+				USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+
+		reg_val = readl(phy_driver->usb2d_idm_regs +
+				USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+		reg_val &= ~(1 << USB2_IDM_IDM_RESET_CONTROL__RESET);
+		writel(reg_val, phy_driver->usb2d_idm_regs +
+				USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+
+	} else {
+		reg_val = readl(phy_driver->usbphy_regs +
+				CDRU_USBPHY_CLK_RST_SEL_OFFSET);
+
+		/*
+		 * Check if the phy that is configured to provide clock
+		 * and reset is powered on.
+		 */
+		if (reg_val >= 0 && reg_val < ARRAY_SIZE(phy_driver->ports))
+			if (phy_driver->ports[reg_val])
+				if (phy_driver->ports[reg_val]->power)
+					clock_reset_flag = false;
+
+		/* if not set the current phy */
+		if (clock_reset_flag) {
+			reg_val = port->port_no;
+			writel(reg_val, phy_driver->usbphy_regs +
+			       CDRU_USBPHY_CLK_RST_SEL_OFFSET);
+		}
+	}
+
+	if (!phy_driver->idm_host_enabled) {
+		/* Enable clock to USB and get the USB out of reset */
+		reg_val = readl(phy_driver->usb2h_idm_regs +
+				USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+		reg_val |= 1 << USB2_IDM_IDM_IO_CONTROL_DIRECT__clk_enable;
+		writel(reg_val, phy_driver->usb2h_idm_regs +
+				USB2_IDM_IDM_IO_CONTROL_DIRECT_OFFSET);
+
+		reg_val = readl(phy_driver->usb2h_idm_regs +
+				USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+		reg_val &= ~(1 << USB2_IDM_IDM_RESET_CONTROL__RESET);
+		writel(reg_val, phy_driver->usb2h_idm_regs +
+				USB2_IDM_IDM_RESET_CONTROL_OFFSET);
+		phy_driver->idm_host_enabled = true;
+	}
+
+	spin_unlock_irqrestore(&phy_driver->lock, flags);
+	return 0;
+
+err_shutdown:
+	spin_unlock_irqrestore(&phy_driver->lock, flags);
+	bcm_phy_shutdown(generic_phy);
+	return ret;
+}
+
+static struct phy_ops ops = {
+	.init		= bcm_phy_init,
+	.power_on	= bcm_phy_poweron,
+	.power_off	= bcm_phy_shutdown,
+};
+
+static const struct of_device_id bcm_phy_dt_ids[] = {
+	{ .compatible = "brcm,cygnus-usb-phy", },
+	{ }
+};
+
+static int bcm_phy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct bcm_phy_driver *phy_driver;
+	struct phy_provider *phy_provider;
+	struct device_node *child;
+	struct resource *res;
+	int error;
+	u32 reg_val;
+
+	phy_driver = devm_kzalloc(dev, sizeof(struct bcm_phy_driver),
+				  GFP_KERNEL);
+	if (!phy_driver)
+		return -ENOMEM;
+
+	spin_lock_init(&phy_driver->lock);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "missing memory resource usbphy_regs\n");
+		return -EINVAL;
+	}
+	phy_driver->usbphy_regs = devm_ioremap_nocache(dev, res->start,
+						resource_size(res));
+	if (!phy_driver->usbphy_regs) {
+		dev_err(dev, "Failed to remap usbphy_regs\n");
+		return -ENOMEM;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res) {
+		dev_err(&pdev->dev, "missing memory resource ubs2h_idm_regs\n");
+		return -EINVAL;
+	}
+	phy_driver->usb2h_idm_regs = devm_ioremap_nocache(dev, res->start,
+						  resource_size(res));
+	if (!phy_driver->usb2h_idm_regs) {
+		dev_err(dev, "Failed to remap usb2h_idm_regs\n");
+		return -ENOMEM;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
+	if (!res) {
+		dev_err(&pdev->dev, "missing memory resource ubs2d_idm_regs\n");
+		return -EINVAL;
+	}
+	phy_driver->usb2d_idm_regs = devm_ioremap_nocache(dev, res->start,
+						   resource_size(res));
+	if (!phy_driver->usb2d_idm_regs) {
+		dev_err(dev, "Failed to remap usb2d_idm_regs\n");
+		return -ENOMEM;
+	}
+
+	dev_set_drvdata(dev, phy_driver);
+
+	phy_driver->idm_host_enabled = false;
+
+	/* Shut down all ports. They can be powered up as required */
+	reg_val = readl(phy_driver->usbphy_regs +
+			CRMU_USB_PHY_AON_CTRL_OFFSET);
+	reg_val &= ~(1 << CRMU_USBPHY_P0_AFE_CORERDY_VDDC);
+	reg_val &= ~(1 << CRMU_USBPHY_P0_RESETB);
+	reg_val &= ~(1 << CRMU_USBPHY_P1_AFE_CORERDY_VDDC);
+	reg_val &= ~(1 << CRMU_USBPHY_P1_RESETB);
+	reg_val &= ~(1 << CRMU_USBPHY_P2_AFE_CORERDY_VDDC);
+	reg_val &= ~(1 << CRMU_USBPHY_P2_RESETB);
+	writel(reg_val, phy_driver->usbphy_regs +
+		CRMU_USB_PHY_AON_CTRL_OFFSET);
+
+	for_each_available_child_of_node(dev->of_node, child) {
+		struct bcm_phy_instance *port;
+		u32 port_no;
+
+		if (of_property_read_u32(child, "reg", &port_no)) {
+			dev_err(dev, "missing reg property in node %s\n",
+				child->name);
+			return -EINVAL;
+		}
+
+		if (port_no >= ARRAY_SIZE(phy_driver->ports)) {
+			dev_err(dev, "invalid reg in node %s: %u\n",
+				child->name, port_no);
+			return -EINVAL;
+		}
+
+		port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+		if (!port)
+			return -ENOMEM;
+
+		port->generic_phy = devm_phy_create(dev, child, &ops);
+		if (IS_ERR(port->generic_phy)) {
+			error = PTR_ERR(port->generic_phy);
+			dev_err(dev, "Failed to create phy %u: %d",
+				port_no, error);
+			return error;
+		}
+
+		port->port_no = port_no;
+		port->driver = phy_driver;
+		phy_set_drvdata(port->generic_phy, port);
+
+		phy_driver->ports[port_no] = port;
+	}
+
+	phy_provider = devm_of_phy_provider_register(dev, bcm_usb_phy_xlate);
+	if (IS_ERR(phy_provider)) {
+		error = PTR_ERR(phy_provider);
+		dev_err(dev, "Failed to register as phy provider: %d\n",
+			error);
+		return error;
+	}
+
+	dev_set_drvdata(pdev, phy_driver);
+
+	return 0;
+
+}
+
+MODULE_DEVICE_TABLE(of, bcm_phy_dt_ids);
+
+static struct platform_driver bcm_phy_driver = {
+	.probe = bcm_phy_probe,
+	.driver = {
+		.name = "bcm-cygnus-usbphy",
+		.of_match_table = of_match_ptr(bcm_phy_dt_ids),
+	},
+};
+module_platform_driver(bcm_phy_driver);
+
+MODULE_ALIAS("platform:bcm-cygnus-usbphy");
+MODULE_AUTHOR("Broadcom");
+MODULE_DESCRIPTION("Broadcom Cygnus USB PHY driver");
+MODULE_LICENSE("GPL v2");
-- 
2.3.4

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