path: root/drivers/usb/host/ehci-tegra.c

/*
 * EHCI-compliant USB host controller driver for NVIDIA Tegra SoCs
 *
 * Copyright (C) 2010 Google, Inc.
 * Copyright (C) 2009 NVIDIA 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; either version 2 of the License, or (at your
 * option) any later version.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/clk.h>
#include <linux/platform_device.h>
#include <linux/tegra_usb.h>
#include <linux/irq.h>
#include <linux/usb/otg.h>
#include <mach/usb_phy.h>

#define TEGRA_USB_USBCMD_REG_OFFSET		0x140
#define TEGRA_USB_USBCMD_RESET			(1 << 1)
#define TEGRA_USB_USBMODE_REG_OFFSET		0x1a8
#define TEGRA_USB_USBMODE_HOST			(3 << 0)
#define TEGRA_USB_PORTSC1_PTC(x)		(((x) & 0xf) << 16)

#define TEGRA_USB_DMA_ALIGN 32

struct tegra_ehci_context {
	bool valid;
	u32 command;
	u32 frame_list;
	u32 async_next;
	u32 txfilltunning;
	u32 otgsc;
	enum tegra_usb_phy_port_speed port_speed;
};

struct tegra_ehci_hcd {
	struct ehci_hcd *ehci;
	struct tegra_usb_phy *phy;
	struct clk *clk;
	struct clk *emc_clk;
	struct otg_transceiver *transceiver;
	int host_resumed;
	int bus_suspended;
	int port_resuming;
	struct tegra_ehci_context context;
	int power_down_on_bus_suspend;
};

static void tegra_ehci_power_up(struct usb_hcd *hcd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);

	clk_enable(tegra->emc_clk);
	clk_enable(tegra->clk);
	tegra_usb_phy_power_on(tegra->phy);
	tegra->host_resumed = 1;
}

static void tegra_ehci_power_down(struct usb_hcd *hcd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);

	tegra->host_resumed = 0;
	tegra_usb_phy_power_off(tegra->phy);
	clk_disable(tegra->clk);
	clk_disable(tegra->emc_clk);
}

static int tegra_ehci_hub_control(
	struct usb_hcd	*hcd,
	u16		typeReq,
	u16		wValue,
	u16		wIndex,
	char		*buf,
	u16		wLength
)
{
	struct ehci_hcd	*ehci = hcd_to_ehci(hcd);
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	u32 __iomem	*status_reg;
	u32		temp;
	unsigned long	flags;
	int		retval = 0;

	status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];

	spin_lock_irqsave(&ehci->lock, flags);

	/*
	 * In ehci_hub_control() for USB_PORT_FEAT_ENABLE clears the other bits
	 * that are write on clear, by writing back the register read value, so
	 * USB_PORT_FEAT_ENABLE is handled by masking the set on clear bits
	 */
	if (typeReq == ClearPortFeature && wValue == USB_PORT_FEAT_ENABLE) {
		temp = ehci_readl(ehci, status_reg);
		ehci_writel(ehci, (temp & ~PORT_RWC_BITS) & ~PORT_PE, status_reg);
		goto done;
	}

	else if (typeReq == GetPortStatus) {
		temp = ehci_readl(ehci, status_reg);
		if (tegra->port_resuming && !(temp & PORT_SUSPEND)) {
			/* resume completed */
			tegra->port_resuming = 0;
			tegra_usb_phy_postresume(tegra->phy);
		}
	}

	else if (typeReq == SetPortFeature && wValue == USB_PORT_FEAT_SUSPEND) {
		temp = ehci_readl(ehci, status_reg);
		if ((temp & PORT_PE) == 0 || (temp & PORT_RESET) != 0) {
			retval = -EPIPE;
			goto done;
		}

		/* After above check the port must be connected.
		 * Set appropriate bit thus could put phy into low power
		 * mode if we have hostpc feature
		 */
		temp &= ~PORT_WKCONN_E;
		temp |= PORT_WKDISC_E | PORT_WKOC_E;
		ehci_writel(ehci, temp | PORT_SUSPEND, status_reg);
		if (handshake(ehci, status_reg, PORT_SUSPEND,
						PORT_SUSPEND, 5000))
			pr_err("%s: timeout waiting for PORT_SUSPEND\n", __func__);
		set_bit((wIndex & 0xff) - 1, &ehci->suspended_ports);
		goto done;
	}

	/*
	 * Tegra host controller will time the resume operation to clear the bit
	 * when the port control state switches to HS or FS Idle. This behavior
	 * is different from EHCI where the host controller driver is required
	 * to set this bit to a zero after the resume duration is timed in the
	 * driver.
	 */
	else if (typeReq == ClearPortFeature && wValue == USB_PORT_FEAT_SUSPEND) {
		temp = ehci_readl(ehci, status_reg);
		if ((temp & PORT_RESET) || !(temp & PORT_PE)) {
			retval = -EPIPE;
			goto done;
		}

		if (!(temp & PORT_SUSPEND))
			goto done;

		tegra_usb_phy_preresume(tegra->phy);

		ehci->reset_done[wIndex-1] = jiffies + msecs_to_jiffies(25);

		temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
		/* start resume signalling */
		ehci_writel(ehci, temp | PORT_RESUME, status_reg);

		spin_unlock_irqrestore(&ehci->lock, flags);
		msleep(20);
		spin_lock_irqsave(&ehci->lock, flags);

		/* polling PORT_RESUME until the controller clear this bit */
		if (handshake(ehci, status_reg, PORT_RESUME, 0, 2000))
			pr_err("%s: timeout waiting for PORT_RESUME\n", __func__);

		/* polling PORT_SUSPEND until the controller clear this bit */
		if (handshake(ehci, status_reg, PORT_SUSPEND, 0, 2000))
			pr_err("%s: timeout waiting for PORT_SUSPEND\n", __func__);

		ehci->reset_done[wIndex-1] = 0;

		tegra->port_resuming = 1;
		goto done;
	}

	spin_unlock_irqrestore(&ehci->lock, flags);

	/* Handle the hub control events here */
	return ehci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
done:
	spin_unlock_irqrestore(&ehci->lock, flags);
	return retval;
}

static void tegra_ehci_restart(struct usb_hcd *hcd)
{
	unsigned int temp;
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);

	/* reset the ehci controller */
	ehci->controller_resets_phy = 0;
	ehci_reset(ehci);
	ehci->controller_resets_phy = 1;

	/* Set to Host mode by setting bit 0-1 of USB device mode register */
	temp = readl(hcd->regs + TEGRA_USB_USBMODE_REG_OFFSET);
	writel((temp | TEGRA_USB_USBMODE_HOST),
		(hcd->regs + TEGRA_USB_USBMODE_REG_OFFSET));

	/* setup the frame list and Async q heads */
	ehci_writel(ehci, ehci->periodic_dma, &ehci->regs->frame_list);
	ehci_writel(ehci, (u32)ehci->async->qh_dma, &ehci->regs->async_next);
	/* setup the command register and set the controller in RUN mode */
	ehci->command &= ~(CMD_LRESET|CMD_IAAD|CMD_PSE|CMD_ASE|CMD_RESET);
	ehci->command |= CMD_RUN;
	ehci_writel(ehci, ehci->command, &ehci->regs->command);

	down_write(&ehci_cf_port_reset_rwsem);
	ehci_writel(ehci, FLAG_CF, &ehci->regs->configured_flag);
	/* flush posted writes */
	ehci_readl(ehci, &ehci->regs->command);
	up_write(&ehci_cf_port_reset_rwsem);
}

static int tegra_usb_suspend(struct usb_hcd *hcd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	struct ehci_regs __iomem *hw = tegra->ehci->regs;
	struct tegra_ehci_context *context = &tegra->context;
	unsigned long flags;

	spin_lock_irqsave(&tegra->ehci->lock, flags);

	context->port_speed = (readl(&hw->port_status[0]) >> 26) & 0x3;

	if (context->port_speed > TEGRA_USB_PHY_PORT_HIGH) {
		/* If no device connection or invalid speeds,
		 * don't save the context */
		context->valid = false;
	} else {
		context->command	= readl(&hw->command);
		context->frame_list	= readl(&hw->frame_list);
		context->async_next	= readl(&hw->async_next);
		context->txfilltunning	= readl(&hw->reserved[2]);
		context->otgsc		= readl(&hw->reserved[18]);
		context->valid = true;
	}

	ehci_halt(tegra->ehci);
	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

	spin_unlock_irqrestore(&tegra->ehci->lock, flags);

	tegra_ehci_power_down(ehci_to_hcd(tegra->ehci));
	return 0;
}

static int tegra_usb_resume(struct usb_hcd *hcd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	struct tegra_ehci_context *context = &tegra->context;
	struct ehci_regs __iomem *hw = tegra->ehci->regs;
	unsigned long val;
	int lp0_resume = 0;

	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
	tegra_ehci_power_up(ehci_to_hcd(tegra->ehci));

	if (!context->valid) {
		/* Wait for the phy to detect new devices
		 * before we restart the controller */
		msleep(10);
		goto restart;
	}

	tegra_ehci_phy_restore_start(tegra->phy, context->port_speed);

	/* Check if the phy resume from LP0. When the phy resume from LP0
	 * USB register will be reset. */
	if (!readl(&hw->async_next))
		lp0_resume = 1;

	/* Restore register context */
	writel(TEGRA_USB_USBMODE_HOST, &hw->reserved[19]);
	writel(context->otgsc,         &hw->reserved[18]);
	writel(context->txfilltunning, &hw->reserved[2]);
	writel(context->async_next,    &hw->async_next);
	writel(context->frame_list,    &hw->frame_list);
	writel(context->command,       &hw->command);

	/* Enable Port Power */
	val = readl(&hw->port_status[0]);
	val |= PORT_POWER;
	writel(val, &hw->port_status[0]);
	udelay(10);

	if (lp0_resume) {
		/* Program the field PTC in PORTSC based on the saved speed mode */
		val = readl(&hw->port_status[0]);
		val &= ~(TEGRA_USB_PORTSC1_PTC(~0));
		if (context->port_speed == TEGRA_USB_PHY_PORT_HIGH)
			val |= TEGRA_USB_PORTSC1_PTC(5);
		else if (context->port_speed == TEGRA_USB_PHY_PORT_SPEED_FULL)
			val |= TEGRA_USB_PORTSC1_PTC(6);
		else if (context->port_speed == TEGRA_USB_PHY_PORT_SPEED_LOW)
			val |= TEGRA_USB_PORTSC1_PTC(7);
		writel(val, &hw->port_status[0]);
		udelay(10);
	}

	/* Disable test mode by setting PTC field to NORMAL_OP */
	val = readl(&hw->port_status[0]);
	val &= ~(TEGRA_USB_PORTSC1_PTC(~0));
	writel(val, &hw->port_status[0]);
	udelay(10);

	/* Poll until CCS is enabled */
	if (handshake(tegra->ehci, &hw->port_status[0], PORT_CONNECT,
							PORT_CONNECT, 2000)) {
		pr_err("%s: timeout waiting for PORT_CONNECT\n", __func__);
		goto restart;
	}

	/* Poll until PE is enabled */
	if (handshake(tegra->ehci, &hw->port_status[0], PORT_PE,
							PORT_PE, 2000)) {
		pr_err("%s: timeout waiting for USB_PORTSC1_PE\n", __func__);
		goto restart;
	}

	/* Clear the PCI status, to avoid an interrupt taken upon resume */
	val = readl(&hw->status);
	val |= STS_PCD;
	writel(val, &hw->status);

	/* Put controller in suspend mode by writing 1 to SUSP bit of PORTSC */
	val = readl(&hw->port_status[0]);
	if ((val & PORT_POWER) && (val & PORT_PE)) {
		val |= PORT_SUSPEND;
		writel(val, &hw->port_status[0]);

		/* Wait until port suspend completes */
		if (handshake(tegra->ehci, &hw->port_status[0], PORT_SUSPEND,
							PORT_SUSPEND, 1000)) {
			pr_err("%s: timeout waiting for PORT_SUSPEND\n",
								__func__);
			goto restart;
		}
	}

	tegra_ehci_phy_restore_end(tegra->phy);

	return 0;

restart:
	if (context->valid)
		tegra_ehci_phy_restore_end(tegra->phy);

	tegra_ehci_restart(hcd);
	return 0;
}

static int tegra_ehci_reset(struct usb_hcd *hcd)
{
	unsigned long temp;
	int usec = 250*1000; /* see ehci_reset */

	temp = readl(hcd->regs + TEGRA_USB_USBCMD_REG_OFFSET);
	temp |= TEGRA_USB_USBCMD_RESET;
	writel(temp, hcd->regs + TEGRA_USB_USBCMD_REG_OFFSET);

	do {
		temp = readl(hcd->regs + TEGRA_USB_USBCMD_REG_OFFSET);
		if (!(temp & TEGRA_USB_USBCMD_RESET))
			break;
		udelay(1);
		usec--;
	} while (usec);

	if (!usec)
		return -ETIMEDOUT;

	/* Set to Host mode by setting bit 0-1 of USB device mode register */
	temp = readl(hcd->regs + TEGRA_USB_USBMODE_REG_OFFSET);
	writel((temp | TEGRA_USB_USBMODE_HOST),
			(hcd->regs + TEGRA_USB_USBMODE_REG_OFFSET));

	return 0;
}

static void tegra_ehci_shutdown(struct usb_hcd *hcd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	/* ehci_shutdown touches the USB controller registers, make sure
	 * controller has clocks to it */
	if (!tegra->host_resumed)
		tegra_ehci_power_up(hcd);

	/* call ehci shut down */
	ehci_shutdown(hcd);
}

static int tegra_ehci_setup(struct usb_hcd *hcd)
{
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
	int retval;

	/* EHCI registers start at offset 0x100 */
	ehci->caps = hcd->regs + 0x100;
	ehci->regs = hcd->regs + 0x100 +
		HC_LENGTH(readl(&ehci->caps->hc_capbase));

	dbg_hcs_params(ehci, "reset");
	dbg_hcc_params(ehci, "reset");

	/* cache this readonly data; minimize chip reads */
	ehci->hcs_params = readl(&ehci->caps->hcs_params);

	retval = ehci_halt(ehci);
	if (retval)
		return retval;

	/* data structure init */
	retval = ehci_init(hcd);
	if (retval)
		return retval;

	hcd->has_tt = 1;
	ehci->sbrn = 0x20;

	ehci_reset(ehci);

	/*
	 * Resetting the controller has the side effect of resetting the PHY.
	 * So, never reset the controller after the calling
	 * tegra_ehci_reinit API.
	 */
	ehci->controller_resets_phy = 1;
	ehci->port_reset_no_wait = 1;

	ehci_port_power(ehci, 1);
	return retval;
}

#ifdef CONFIG_PM
static int tegra_ehci_bus_suspend(struct usb_hcd *hcd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	int error_status = 0;

	error_status = ehci_bus_suspend(hcd);
	if (!error_status && tegra->power_down_on_bus_suspend) {
		tegra_usb_suspend(hcd);
		tegra->bus_suspended = 1;
	}

	return error_status;
}

static int tegra_ehci_bus_resume(struct usb_hcd *hcd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);

	if (tegra->bus_suspended && tegra->power_down_on_bus_suspend) {
		tegra_usb_resume(hcd);
		tegra->bus_suspended = 0;
	}

	tegra_usb_phy_preresume(tegra->phy);
	tegra->port_resuming = 1;
	return ehci_bus_resume(hcd);
}
#endif

struct temp_buffer {
	void *kmalloc_ptr;
	void *old_xfer_buffer;
	u8 data[0];
};

static void free_temp_buffer(struct urb *urb)
{
	enum dma_data_direction dir;
	struct temp_buffer *temp;

	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
		return;

	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

	temp = container_of(urb->transfer_buffer, struct temp_buffer,
			    data);

	if (dir == DMA_FROM_DEVICE)
		memcpy(temp->old_xfer_buffer, temp->data,
		       urb->transfer_buffer_length);
	urb->transfer_buffer = temp->old_xfer_buffer;
	kfree(temp->kmalloc_ptr);

	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
}

static int alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
{
	enum dma_data_direction dir;
	struct temp_buffer *temp, *kmalloc_ptr;
	size_t kmalloc_size;

	if (urb->num_sgs || urb->sg ||
	    urb->transfer_buffer_length == 0 ||
	    !((uintptr_t)urb->transfer_buffer & (TEGRA_USB_DMA_ALIGN - 1)))
		return 0;

	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;

	/* Allocate a buffer with enough padding for alignment */
	kmalloc_size = urb->transfer_buffer_length +
		sizeof(struct temp_buffer) + TEGRA_USB_DMA_ALIGN - 1;

	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
	if (!kmalloc_ptr)
		return -ENOMEM;

	/* Position our struct temp_buffer such that data is aligned */
	temp = PTR_ALIGN(kmalloc_ptr + 1, TEGRA_USB_DMA_ALIGN) - 1;

	temp->kmalloc_ptr = kmalloc_ptr;
	temp->old_xfer_buffer = urb->transfer_buffer;
	if (dir == DMA_TO_DEVICE)
		memcpy(temp->data, urb->transfer_buffer,
		       urb->transfer_buffer_length);
	urb->transfer_buffer = temp->data;

	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;

	return 0;
}

static int tegra_ehci_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
				      gfp_t mem_flags)
{
	int ret;

	ret = alloc_temp_buffer(urb, mem_flags);
	if (ret)
		return ret;

	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
	if (ret)
		free_temp_buffer(urb);

	return ret;
}

static void tegra_ehci_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
{
	usb_hcd_unmap_urb_for_dma(hcd, urb);
	free_temp_buffer(urb);
}

static const struct hc_driver tegra_ehci_hc_driver = {
	.description		= hcd_name,
	.product_desc		= "Tegra EHCI Host Controller",
	.hcd_priv_size		= sizeof(struct ehci_hcd),

	.flags			= HCD_USB2 | HCD_MEMORY,

	.reset			= tegra_ehci_setup,
	.irq			= ehci_irq,

	.start			= ehci_run,
	.stop			= ehci_stop,
	.shutdown		= tegra_ehci_shutdown,
	.urb_enqueue		= ehci_urb_enqueue,
	.urb_dequeue		= ehci_urb_dequeue,
	.map_urb_for_dma	= tegra_ehci_map_urb_for_dma,
	.unmap_urb_for_dma	= tegra_ehci_unmap_urb_for_dma,
	.endpoint_disable	= ehci_endpoint_disable,
	.endpoint_reset		= ehci_endpoint_reset,
	.get_frame_number	= ehci_get_frame,
	.hub_status_data	= ehci_hub_status_data,
	.hub_control		= tegra_ehci_hub_control,
	.clear_tt_buffer_complete = ehci_clear_tt_buffer_complete,
#ifdef CONFIG_PM
	.bus_suspend		= tegra_ehci_bus_suspend,
	.bus_resume		= tegra_ehci_bus_resume,
#endif
	.relinquish_port	= ehci_relinquish_port,
	.port_handed_over	= ehci_port_handed_over,
};

static int tegra_ehci_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct usb_hcd *hcd;
	struct ehci_hcd *ehci;
	struct tegra_ehci_hcd *tegra;
	struct tegra_ehci_platform_data *pdata;
	struct tegra_utmip_config *config;
	int err = 0;
	int irq;
	int instance = pdev->id;

	pdata = pdev->dev.platform_data;
	if (!pdata) {
		dev_err(&pdev->dev, "Platform data missing\n");
		return -EINVAL;
	}

	tegra = kzalloc(sizeof(struct tegra_ehci_hcd), GFP_KERNEL);
	if (!tegra)
		return -ENOMEM;

	hcd = usb_create_hcd(&tegra_ehci_hc_driver, &pdev->dev,
					dev_name(&pdev->dev));
	if (!hcd) {
		dev_err(&pdev->dev, "Unable to create HCD\n");
		err = -ENOMEM;
		goto fail_hcd;
	}

	platform_set_drvdata(pdev, tegra);

	tegra->clk = clk_get(&pdev->dev, NULL);
	if (IS_ERR(tegra->clk)) {
		dev_err(&pdev->dev, "Can't get ehci clock\n");
		err = PTR_ERR(tegra->clk);
		goto fail_clk;
	}

	err = clk_enable(tegra->clk);
	if (err)
		goto fail_clken;

	tegra->emc_clk = clk_get(&pdev->dev, "emc");
	if (IS_ERR(tegra->emc_clk)) {
		dev_err(&pdev->dev, "Can't get emc clock\n");
		err = PTR_ERR(tegra->emc_clk);
		goto fail_emc_clk;
	}

	clk_enable(tegra->emc_clk);
	clk_set_rate(tegra->emc_clk, 400000000);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "Failed to get I/O memory\n");
		err = -ENXIO;
		goto fail_io;
	}
	hcd->rsrc_start = res->start;
	hcd->rsrc_len = resource_size(res);
	hcd->regs = ioremap(res->start, resource_size(res));
	if (!hcd->regs) {
		dev_err(&pdev->dev, "Failed to remap I/O memory\n");
		err = -ENOMEM;
		goto fail_io;
	}

	config = pdata->phy_config;

	tegra->phy = tegra_usb_phy_open(instance, hcd->regs, config,
						TEGRA_USB_PHY_MODE_HOST);
	if (IS_ERR(tegra->phy)) {
		dev_err(&pdev->dev, "Failed to open USB phy\n");
		err = -ENXIO;
		goto fail_phy;
	}

	err = tegra_ehci_reset(hcd);
	if (err) {
		dev_err(&pdev->dev, "Failed to reset controller\n");
		goto fail;
	}

	tegra_usb_phy_power_on(tegra->phy);
	tegra->host_resumed = 1;
	tegra->power_down_on_bus_suspend = pdata->power_down_on_bus_suspend;

	irq = platform_get_irq(pdev, 0);
	if (!irq) {
		dev_err(&pdev->dev, "Failed to get IRQ\n");
		err = -ENODEV;
		goto fail;
	}

	set_irq_flags(irq, IRQF_VALID);

	ehci = hcd_to_ehci(hcd);
	tegra->ehci = ehci;

#ifdef CONFIG_USB_OTG_UTILS
	if (pdata->operating_mode == TEGRA_USB_OTG) {
		tegra->transceiver = otg_get_transceiver();
		if (tegra->transceiver)
			otg_set_host(tegra->transceiver, &hcd->self);
	}
#endif

	err = usb_add_hcd(hcd, irq, IRQF_DISABLED | IRQF_SHARED);
	if (err != 0) {
		dev_err(&pdev->dev, "Failed to add USB HCD\n");
		goto fail;
	}

	return err;

fail:
#ifdef CONFIG_USB_OTG_UTILS
	if (tegra->transceiver) {
		otg_set_host(tegra->transceiver, NULL);
		otg_put_transceiver(tegra->transceiver);
	}
#endif
	tegra_usb_phy_close(tegra->phy);
fail_phy:
	iounmap(hcd->regs);
fail_io:
	clk_disable(tegra->emc_clk);
	clk_put(tegra->emc_clk);
fail_emc_clk:
	clk_disable(tegra->clk);
fail_clken:
	clk_put(tegra->clk);
fail_clk:
	usb_put_hcd(hcd);
fail_hcd:
	kfree(tegra);
	return err;
}

#ifdef CONFIG_PM
static int tegra_ehci_resume(struct platform_device *pdev)
{
	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);

	if (tegra->bus_suspended)
		return 0;

	return tegra_usb_resume(hcd);
}

static int tegra_ehci_suspend(struct platform_device *pdev, pm_message_t state)
{
	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);

	if (tegra->bus_suspended)
		return 0;

	if (time_before(jiffies, tegra->ehci->next_statechange))
		msleep(10);

	return tegra_usb_suspend(hcd);
}
#endif

static int tegra_ehci_remove(struct platform_device *pdev)
{
	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);

	if (tegra == NULL || hcd == NULL)
		return -EINVAL;

#ifdef CONFIG_USB_OTG_UTILS
	if (tegra->transceiver) {
		otg_set_host(tegra->transceiver, NULL);
		otg_put_transceiver(tegra->transceiver);
	}
#endif

	usb_remove_hcd(hcd);
	usb_put_hcd(hcd);

	tegra_usb_phy_close(tegra->phy);
	iounmap(hcd->regs);

	clk_disable(tegra->clk);
	clk_put(tegra->clk);

	clk_disable(tegra->emc_clk);
	clk_put(tegra->emc_clk);

	kfree(tegra);
	return 0;
}

static void tegra_ehci_hcd_shutdown(struct platform_device *pdev)
{
	struct tegra_ehci_hcd *tegra = platform_get_drvdata(pdev);
	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);

	if (hcd->driver->shutdown)
		hcd->driver->shutdown(hcd);
}

static struct platform_driver tegra_ehci_driver = {
	.probe		= tegra_ehci_probe,
	.remove		= tegra_ehci_remove,
#ifdef CONFIG_PM
	.suspend	= tegra_ehci_suspend,
	.resume		= tegra_ehci_resume,
#endif
	.shutdown	= tegra_ehci_hcd_shutdown,
	.driver		= {
		.name	= "tegra-ehci",
	}
};