/*
 * EHCI-compliant USB host controller driver for NVIDIA Tegra SoCs
 *
 * Copyright (C) 2010 Google, Inc.
 * Copyright (C) 2009 - 2011 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.
 *
 */

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

#define TEGRA_USB_PORTSC_PHCD		(1 << 23)

#define TEGRA_USB_SUSP_CTRL_OFFSET	0x400
#define TEGRA_USB_SUSP_CLR			(1 << 5)
#define TEGRA_USB_PHY_CLK_VALID			(1 << 7)
#define TEGRA_USB_SRT				(1 << 25)
#define TEGRA_USB_PHY_CLK_VALID_INT_ENB		(1 << 9)
#define TEGRA_USB_PHY_CLK_VALID_INT_STS		(1 << 8)

#ifdef CONFIG_ARCH_TEGRA_2x_SOC
#define TEGRA_USB_PORTSC1_OFFSET	0x184
#else
#define TEGRA_USB_PORTSC1_OFFSET	0x174
#endif
#define TEGRA_USB_PORTSC1_WKCN			(1 << 20)

#define TEGRA_LVL2_CLK_GATE_OVRB	0xfc
#define TEGRA_USB2_CLK_OVR_ON			(1 << 10)

#define TEGRA_USB_DMA_ALIGN 32

#define STS_SRI	(1<<7)	/*	SOF Recieved	*/

#define TEGRA_HSIC_CONNECTION_MAX_RETRIES 5
#define HOSTPC_REG_OFFSET       0x1b4

#define HOSTPC1_DEVLC_STS 		(1 << 28)
#define HOSTPC1_DEVLC_PTS(x)		(((x) & 0x7) << 29)

struct tegra_ehci_hcd {
	struct ehci_hcd *ehci;
	struct tegra_usb_phy *phy;
	struct clk *clk;
	struct clk *emc_clk;
	struct clk *sclk_clk;
	struct otg_transceiver *transceiver;
	int host_resumed;
	int bus_suspended;
	int port_resuming;
	int power_down_on_bus_suspend;
	struct delayed_work work;
	enum tegra_usb_phy_port_speed port_speed;
	struct work_struct clk_timer_work;
	struct timer_list clk_timer;
	struct timer_list timer_device_detect;
	bool clock_enabled;
	int hsic_connect_retries;
	struct mutex tegra_ehci_hcd_mutex;
};

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

#ifndef CONFIG_USB_HOTPLUG
	clk_enable(tegra->clk);
#endif
	tegra_usb_phy_power_on(tegra->phy, is_dpd);
	tegra->host_resumed = 1;
}

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

	tegra->host_resumed = 0;
	tegra_usb_phy_power_off(tegra->phy, is_dpd);
#ifndef CONFIG_USB_HOTPLUG
	clk_disable(tegra->clk);
#endif
#ifndef CONFIG_ARCH_TEGRA_2x_SOC
	if (tegra->phy->instance == 2) {
		if (mod_timer(&tegra->timer_device_detect,
			jiffies + msecs_to_jiffies(2000)))
			pr_err("timer configuration failed \n");
	}
#endif
}

static irqreturn_t tegra_ehci_irq (struct usb_hcd *hcd)
{
	struct ehci_hcd *ehci = hcd_to_ehci (hcd);
	struct ehci_regs __iomem *hw = ehci->regs;
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	u32 val;

	if (tegra->phy->instance == 2) {
		spin_lock(&ehci->lock);
		val = readl(hcd->regs + TEGRA_USB_SUSP_CTRL_OFFSET);
		if ((val  & TEGRA_USB_PHY_CLK_VALID_INT_STS)) {
			val &= ~TEGRA_USB_PHY_CLK_VALID_INT_ENB |
				TEGRA_USB_PHY_CLK_VALID_INT_STS;
			writel(val , (hcd->regs + TEGRA_USB_SUSP_CTRL_OFFSET));

			val = readl(hcd->regs + TEGRA_USB_PORTSC1_OFFSET);
			val &= ~TEGRA_USB_PORTSC1_WKCN;
			writel(val , (hcd->regs + TEGRA_USB_PORTSC1_OFFSET));

			val = readl(&hw->status);
			if (!(val  & STS_PCD)) {
				spin_unlock(&ehci->lock);
				return 0;
			}
		}
		spin_unlock(&ehci->lock);
	}
	return ehci_irq(hcd);
}

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);
	int		ports = HCS_N_PORTS(ehci->hcs_params);
	u32		temp, status;
	u32 __iomem	*status_reg;
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
	u32		usbsts_reg;
#endif
	unsigned long	flags;
	int		retval = 0;
	unsigned	selector;
	struct		tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	bool		hsic = false;

	if (!tegra->host_resumed) {
		if (buf)
			memset (buf, 0, wLength);
		return retval;
	}

	hsic = (tegra->phy->usb_phy_type == TEGRA_USB_PHY_TYPE_HSIC);

	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) & ~PORT_RWC_BITS;
		ehci_writel(ehci, temp & ~PORT_PE, status_reg);
		goto done;
	} else if (typeReq == GetPortStatus) {
		temp = ehci_readl(ehci, status_reg);
		if (tegra->port_resuming && !(temp & PORT_SUSPEND) &&
		    time_after_eq(jiffies, ehci->reset_done[wIndex-1])) {
			/* Resume completed, re-enable disconnect detection */
			tegra->port_resuming = 0;
			clear_bit((wIndex & 0xff) - 1, &ehci->suspended_ports);
			ehci->reset_done[wIndex-1] = 0;
			tegra_usb_phy_postresume(tegra->phy, false);
#ifndef CONFIG_ARCH_TEGRA_2x_SOC
			ehci->command |= CMD_RUN;
			ehci_writel(ehci, ehci->command, &ehci->regs->command);
#endif
		}
	} 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;
		}

		temp &= ~PORT_WKCONN_E;
		temp |= PORT_WKDISC_E | PORT_WKOC_E;
		ehci_writel(ehci, temp | PORT_SUSPEND, status_reg);
		/* Need a 4ms delay before the controller goes to suspend */
		mdelay(4);

		/*
		 * If a transaction is in progress, there may be a delay in
		 * suspending the port. Poll until the port is suspended.
		 */
		if (handshake(ehci, status_reg, PORT_SUSPEND,
						PORT_SUSPEND, 5000))
			pr_err("%s: timeout waiting for SUSPEND\n", __func__);

		set_bit((wIndex & 0xff) - 1, &ehci->suspended_ports);

		tegra_usb_phy_postsuspend(tegra->phy, false);

		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->port_resuming = 1;

		/* Disable disconnect detection during port resume */
		tegra_usb_phy_preresume(tegra->phy, false);
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
		ehci_dbg(ehci, "%s:USBSTS = 0x%x", __func__,
			ehci_readl(ehci, &ehci->regs->status));
		usbsts_reg = ehci_readl(ehci, &ehci->regs->status);
		ehci_writel(ehci, usbsts_reg, &ehci->regs->status);
		usbsts_reg = ehci_readl(ehci, &ehci->regs->status);
		udelay(20);

		if (handshake(ehci, &ehci->regs->status, STS_SRI, STS_SRI, 2000))
			pr_err("%s: timeout set for STS_SRI\n", __func__);

		usbsts_reg = ehci_readl(ehci, &ehci->regs->status);
		ehci_writel(ehci, usbsts_reg, &ehci->regs->status);

		if (handshake(ehci, &ehci->regs->status, STS_SRI, 0, 2000))
			pr_err("%s: timeout clear STS_SRI\n", __func__);

		if (handshake(ehci, &ehci->regs->status, STS_SRI, STS_SRI, 2000))
			pr_err("%s: timeout set STS_SRI\n", __func__);

		udelay(20);
#endif
		temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
		/* start resume signaling */
		ehci_writel(ehci, temp | PORT_RESUME, status_reg);

		ehci->reset_done[wIndex-1] = jiffies + msecs_to_jiffies(25);
		/* whoever resumes must GetPortStatus to complete it!! */
		goto done;
	}

	/* Handle port reset here */
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
	if ((hsic) && (typeReq == SetPortFeature) &&
		((wValue == USB_PORT_FEAT_RESET) || (wValue == USB_PORT_FEAT_POWER))) {
#else
	if ((hsic) && (typeReq == SetPortFeature) &&
		(wValue == USB_PORT_FEAT_POWER)) {
#endif
		selector = wIndex >> 8;
		wIndex &= 0xff;
		if (!wIndex || wIndex > ports) {
			retval = -EPIPE;
			goto done;
		}
		wIndex--;
		status = 0;
		temp = ehci_readl(ehci, status_reg);
		if (temp & PORT_OWNER)
			goto done;
		temp &= ~PORT_RWC_BITS;

		switch (wValue) {
#ifdef CONFIG_ARCH_TEGRA_2x_SOC
		case USB_PORT_FEAT_RESET:
		{
			if (temp & PORT_RESUME) {
				retval = -EPIPE;
				goto done;
			}
			/* line status bits may report this as low speed,
			* which can be fine if this root hub has a
			* transaction translator built in.
			*/
			if ((temp & (PORT_PE|PORT_CONNECT)) == PORT_CONNECT
					&& !ehci_is_TDI(ehci) && PORT_USB11 (temp)) {
				ehci_dbg (ehci, "port %d low speed --> companion\n", wIndex + 1);
				temp |= PORT_OWNER;
				ehci_writel(ehci, temp, status_reg);
			} else {
				ehci_vdbg(ehci, "port %d reset\n", wIndex + 1);
				temp &= ~PORT_PE;
				/*
				* caller must wait, then call GetPortStatus
				* usb 2.0 spec says 50 ms resets on root
				*/
				ehci->reset_done[wIndex] = jiffies + msecs_to_jiffies(50);
				ehci_writel(ehci, temp, status_reg);
				if (hsic && (wIndex == 0))
					tegra_usb_phy_bus_reset(tegra->phy);
			}

			break;
		}
#endif
		case USB_PORT_FEAT_POWER:
		{
			if (HCS_PPC(ehci->hcs_params))
				ehci_writel(ehci, temp | PORT_POWER, status_reg);
			if (hsic && (wIndex == 0))
				tegra_usb_phy_bus_connect(tegra->phy);
			break;
		}
		}
		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;
}

#ifdef CONFIG_PM
static void tegra_ehci_restart(struct usb_hcd *hcd)
{
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	unsigned int temp;

	ehci->controller_resets_phy = 0;
	ehci_reset(ehci);
	tegra_ehci_post_reset(tegra->phy, false);

	if (tegra->phy->usb_phy_type == TEGRA_USB_PHY_TYPE_NULL_ULPI)
		ehci->controller_resets_phy = 1;

	/* 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);

	/* Enable the root Port Power */
	if (HCS_PPC(ehci->hcs_params)) {
		temp = ehci_readl(ehci, &ehci->regs->port_status[0]);
		ehci_writel(ehci, temp | PORT_POWER, &ehci->regs->port_status[0]);
	}

	down_write(&ehci_cf_port_reset_rwsem);
	hcd->state = HC_STATE_RUNNING;
	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);

	/* Turn On Interrupts */
	ehci_writel(ehci, INTR_MASK, &ehci->regs->intr_enable);
}

static int tegra_usb_suspend(struct usb_hcd *hcd, bool is_dpd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	struct ehci_regs __iomem *hw = tegra->ehci->regs;
	unsigned long flags;
	int hsic = 0;

	hsic = (tegra->phy->usb_phy_type == TEGRA_USB_PHY_TYPE_HSIC);

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

	if (tegra->ehci->has_hostpc)
		tegra->port_speed = (readl(hcd->regs + HOSTPC_REG_OFFSET) >> 25) & 0x3;
	else
		tegra->port_speed = (readl(&hw->port_status[0]) >> 26) & 0x3;
	ehci_halt(tegra->ehci);
#ifndef CONFIG_ARCH_TEGRA_2x_SOC
	tegra->ehci->command = ehci_readl(tegra->ehci,
					&tegra->ehci->regs->command);
#endif

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

	tegra_ehci_power_down(hcd, is_dpd);
	return 0;
}

static int tegra_usb_resume(struct usb_hcd *hcd, bool is_dpd)
{
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	struct usb_device *udev = hcd->self.root_hub;
	struct ehci_hcd	*ehci = hcd_to_ehci(hcd);
	struct ehci_regs __iomem *hw = ehci->regs;
	unsigned long val;
	int hsic = 0;

	hsic = (tegra->phy->usb_phy_type == TEGRA_USB_PHY_TYPE_HSIC);

	tegra_ehci_power_up(hcd, is_dpd);
	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);

	if ((tegra->port_speed > TEGRA_USB_PHY_PORT_SPEED_HIGH) || (hsic))
		goto restart;

	/* Force the phy to keep data lines in suspend state */
	tegra_ehci_phy_restore_start(tegra->phy, tegra->port_speed);

	if (tegra->ehci->has_hostpc)
		ehci_reset(ehci);

	/* Enable host mode */
	tdi_reset(ehci);

	if (tegra->ehci->has_hostpc) {
		val = readl(hcd->regs + HOSTPC_REG_OFFSET);
		val &= ~HOSTPC1_DEVLC_PTS(~0);
		val |= HOSTPC1_DEVLC_STS;
		writel(val, hcd->regs + HOSTPC_REG_OFFSET);
	}

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

	/* Check if the phy resume from LP0. When the phy resume from LP0
	 * USB register will be reset. */
	if (!readl(&hw->async_next)) {
		/* Program the field PTC based on the saved speed mode */
		val = readl(&hw->port_status[0]);
		val &= ~PORT_TEST(~0);
		if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_HIGH)
			val |= PORT_TEST_FORCE;
		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_FULL)
			val |= PORT_TEST(6);
		else if (tegra->port_speed == TEGRA_USB_PHY_PORT_SPEED_LOW)
			val |= PORT_TEST(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 &= ~PORT_TEST(~0);
		writel(val, &hw->port_status[0]);
		udelay(10);
	}

	/* Poll until CCS is enabled */
	if (handshake(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(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]);
		/* Need a 4ms delay before the controller goes to suspend */
		mdelay(4);

		/* Wait until port suspend completes */
		if (handshake(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 ((tegra->port_speed <= TEGRA_USB_PHY_PORT_SPEED_HIGH) && (!hsic))
		tegra_ehci_phy_restore_end(tegra->phy);
	if (hsic) {
		val = readl(&hw->port_status[0]);
		if (!((val & PORT_POWER) && (val & PORT_PE))) {
			tegra_ehci_restart(hcd);
			usb_set_device_state(udev, USB_STATE_CONFIGURED);
		}
		tegra_usb_phy_bus_idle(tegra->phy);
		tegra->hsic_connect_retries = 0;
		if (!tegra_usb_phy_is_device_connected(tegra->phy))
			schedule_delayed_work(&tegra->work, 50);
	} else {
		tegra_ehci_restart(hcd);
	}

	return 0;
}
#endif

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

	mutex_lock(&tegra->tegra_ehci_hcd_mutex);
	/* ehci_shutdown touches the USB controller registers, make sure
	 * controller has clocks to it */
	if (!tegra->host_resumed)
		tegra_ehci_power_up(hcd, false);

	ehci_shutdown(hcd);

	/* we are ready to shut down, powerdown the phy */
	tegra_ehci_power_down(hcd, false);
	mutex_unlock(&tegra->tegra_ehci_hcd_mutex);
}

static int tegra_ehci_setup(struct usb_hcd *hcd)
{
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	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);

#ifndef CONFIG_ARCH_TEGRA_2x_SOC
	ehci->has_hostpc = 1;
#endif
	hcd->has_tt = 1;

	if (tegra->phy->usb_phy_type != TEGRA_USB_PHY_TYPE_NULL_ULPI) {
		ehci_reset(ehci);
		tegra_ehci_post_reset(tegra->phy, false);
	}

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

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

	ehci->sbrn = 0x20;

	if (tegra->phy->usb_phy_type == TEGRA_USB_PHY_TYPE_NULL_ULPI) {
		ehci_reset(ehci);
		tegra_ehci_post_reset(tegra->phy, false);

		/*
		 * 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_power(ehci, 1);
	return retval;
}

#ifdef CONFIG_PM
static int tegra_ehci_bus_suspend(struct usb_hcd *hcd)
{
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(hcd->self.controller);
	u32 port_status;
	int error_status = 0;

	error_status = ehci_bus_suspend(hcd);
	if (!error_status && tegra->power_down_on_bus_suspend) {
		port_status = ehci_readl(ehci, &ehci->regs->port_status[0]);
		if (!port_status & PORT_CONNECT) {
			tegra_usb_suspend(hcd, false);
			tegra->bus_suspended = 1;
		}
	}
	tegra_usb_phy_postsuspend(tegra->phy, false);

	return error_status;
}

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

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

	ehci_bus_resumed = ehci_bus_resume(hcd);
	mutex_unlock(&tegra->tegra_ehci_hcd_mutex);
	return ehci_bus_resumed;
}
#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 void tegra_hsic_connection_work(struct work_struct *work)
{
	struct tegra_ehci_hcd *tegra =
		container_of(work, struct tegra_ehci_hcd, work.work);
	if (tegra_usb_phy_is_device_connected(tegra->phy)) {
		cancel_delayed_work(&tegra->work);
		return;
	}
	/* Few cases HSIC device may not be connected, so   *
	** skip this check after configured max re-tries.   */
	if (tegra->hsic_connect_retries++ > TEGRA_HSIC_CONNECTION_MAX_RETRIES)
		return;

	schedule_delayed_work(&tegra->work, jiffies + msecs_to_jiffies(50));
	return;
}

#ifdef CONFIG_USB_EHCI_ONOFF_FEATURE
/* Stored ehci handle for hsic insatnce */
struct usb_hcd *ehci_handle;
int ehci_tegra_irq;

static ssize_t show_ehci_power(struct device *dev,
			struct device_attribute *attr,
			char *buf)
{
	return sprintf(buf, "EHCI Power %s\n", (ehci_handle) ? "on" : "off");
}

static ssize_t store_ehci_power(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
{
	int power_on;
	int retval;
	struct tegra_ehci_hcd *tegra = dev_get_drvdata(dev);
	struct usb_hcd *hcd = ehci_to_hcd(tegra->ehci);

	if (sscanf(buf, "%d", &power_on) != 1)
		return -EINVAL;

	if (power_on == 0 && ehci_handle != NULL) {
		usb_remove_hcd(hcd);
		tegra_ehci_power_down(hcd, false);
		ehci_handle = NULL;
	} else if (power_on == 1) {
		if (ehci_handle)
			usb_remove_hcd(hcd);
		tegra_ehci_power_up(hcd, false);
		retval = usb_add_hcd(hcd, ehci_tegra_irq,
					IRQF_DISABLED | IRQF_SHARED);
		if (retval < 0)
			printk(KERN_ERR "power_on error\n");
		ehci_handle = hcd;
	}

	return count;
}

static DEVICE_ATTR(ehci_power, S_IRUSR | S_IRGRP | S_IWUSR | S_IWGRP,
		show_ehci_power, store_ehci_power);

static inline int create_ehci_sys_file(struct ehci_hcd *ehci)
{
	return device_create_file(ehci_to_hcd(ehci)->self.controller,
							&dev_attr_ehci_power);
}

static inline void remove_ehci_sys_file(struct ehci_hcd *ehci)
{
	device_remove_file(ehci_to_hcd(ehci)->self.controller,
						&dev_attr_ehci_power);
}

#endif

void clk_timer_callback(unsigned long data)
{
	struct tegra_ehci_hcd *tegra = (struct tegra_ehci_hcd*) data;
	unsigned long flags;

	if (!timer_pending(&tegra->clk_timer)) {
		clk_disable(tegra->emc_clk);
		clk_disable(tegra->sclk_clk);
		spin_lock_irqsave(&tegra->ehci->lock, flags);
		tegra->clock_enabled = 0;
		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
	}
}

void timer_callback_device_detect(unsigned long data)
{
#ifndef CONFIG_ARCH_TEGRA_2x_SOC
	struct tegra_ehci_hcd *tegra = (struct tegra_ehci_hcd*) data;
	int ret;
	u32 val;
	struct usb_hcd *hcd;
	u32 timer_deactivated;
	hcd = ehci_to_hcd(tegra->ehci);

	if(tegra->phy->instance == 2) {
		val = tegra_usb_phy_is_device_detected(tegra->phy);
		if (val) {
			timer_deactivated = del_timer(
				&tegra->timer_device_detect);
			if (timer_deactivated)
				pr_err("timer deactivation failed \n");
			tegra_ehci_power_up(hcd, false);
		} else {
			ret = mod_timer(&tegra->timer_device_detect,
					jiffies + msecs_to_jiffies(2000));
			if (ret)
				pr_err("tegra device detect failed \n");
		}
	}
#endif
}

static void clk_timer_work_handler(struct work_struct* clk_timer_work) {
	struct tegra_ehci_hcd *tegra = container_of(clk_timer_work,
						struct tegra_ehci_hcd, clk_timer_work);
	int ret;
	unsigned long flags;
	bool clock_enabled;

	spin_lock_irqsave(&tegra->ehci->lock, flags);
	clock_enabled = tegra->clock_enabled;
	spin_unlock_irqrestore(&tegra->ehci->lock, flags);
	if ((!clock_enabled)) {
		ret = mod_timer(&tegra->clk_timer, jiffies + msecs_to_jiffies(2000));
		if (ret)
			pr_err("tegra_ehci_urb_enqueue timer modify failed \n");
		clk_enable(tegra->emc_clk);
		clk_enable(tegra->sclk_clk);
		spin_lock_irqsave(&tegra->ehci->lock, flags);
		tegra->clock_enabled = 1;
		spin_unlock_irqrestore(&tegra->ehci->lock, flags);
	} else {
		if (timer_pending(&tegra->clk_timer)) {
			mod_timer_pending (&tegra->clk_timer, jiffies
						+ msecs_to_jiffies(2000));
		}
	}
}

static int tegra_ehci_urb_enqueue (
	struct usb_hcd	*hcd,
	struct urb	*urb,
	gfp_t		mem_flags)
{
	struct tegra_ehci_hcd *pdata;
	int xfertype;
	int transfer_buffer_length;
	struct ehci_hcd *ehci = hcd_to_ehci(hcd);
	unsigned long flags;
	pdata = dev_get_drvdata(hcd->self.controller);

	xfertype = usb_endpoint_type(&urb->ep->desc);
	transfer_buffer_length = urb->transfer_buffer_length;
	spin_lock_irqsave(&ehci->lock,flags);
	/* Turn on the USB busy hints */
	switch (xfertype) {
		case USB_ENDPOINT_XFER_INT:
		if (transfer_buffer_length < 255) {
		/* Do nothing for interrupt buffers < 255 */
		} else {
			/* signal to set the busy hints */
			schedule_work(&pdata->clk_timer_work);
		}
		break;
		case USB_ENDPOINT_XFER_ISOC:
		case USB_ENDPOINT_XFER_BULK:
			/* signal to set the busy hints */
			schedule_work(&pdata->clk_timer_work);
		break;
		case USB_ENDPOINT_XFER_CONTROL:
		default:
			/* Do nothing special here */
		break;
	}
	spin_unlock_irqrestore(&ehci->lock,flags);
	return ehci_urb_enqueue(hcd, urb, mem_flags);
}

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			= tegra_ehci_irq,

	.start			= ehci_run,
	.stop			= ehci_stop,
	.shutdown		= tegra_ehci_shutdown,
	.urb_enqueue		= tegra_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 tegra_ehci_hcd *tegra;
	struct tegra_ehci_platform_data *pdata;
	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;

	mutex_init(&tegra->tegra_ehci_hcd_mutex);

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

	clk_set_rate(tegra->sclk_clk, 80000000);

	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;
	}
	init_timer(&tegra->clk_timer);
	tegra->clk_timer.function = clk_timer_callback;
	tegra->clk_timer.data = (unsigned long) tegra;

	init_timer(&tegra->timer_device_detect);
	tegra->timer_device_detect.function = timer_callback_device_detect;
	tegra->timer_device_detect.data = (unsigned long) tegra;

#ifdef CONFIG_ARCH_TEGRA_2x_SOC
	/* Set DDR busy hints to 150MHz. For Tegra 2x SOC, DDR rate is half of EMC rate */
	clk_set_rate(tegra->emc_clk, 300000000);
#else
	/* Set DDR busy hints to 150MHz. For Tegra 3x SOC DDR rate equals to EMC rate */
	clk_set_rate(tegra->emc_clk, 150000000);
#endif

	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;
	}

	INIT_DELAYED_WORK(&tegra->work, tegra_hsic_connection_work);

	INIT_WORK(&tegra->clk_timer_work, clk_timer_work_handler);

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

	err = tegra_usb_phy_power_on(tegra->phy, true);
	if (err) {
		dev_err(&pdev->dev, "Failed to power on the phy\n");
		goto fail;
	}

	tegra->host_resumed = 1;
	tegra->power_down_on_bus_suspend = pdata->power_down_on_bus_suspend;
	tegra->ehci = hcd_to_ehci(hcd);

	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);

#ifdef CONFIG_USB_EHCI_ONOFF_FEATURE
	if (instance == 1) {
		ehci_tegra_irq = irq;
		create_ehci_sys_file(tegra->ehci);
	}
#endif

#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) {
		dev_err(&pdev->dev, "Failed to add USB HCD\n");
		goto fail;
	}

#ifdef CONFIG_USB_EHCI_ONOFF_FEATURE
	if (instance == 1)
		ehci_handle = hcd;
#endif
	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->sclk_clk);
	clk_put(tegra->sclk_clk);
fail_sclk_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) && (tegra->power_down_on_bus_suspend)) {
#ifdef CONFIG_USB_HOTPLUG
		clk_enable(tegra->clk);
#endif
		return 0;
	}

#ifdef CONFIG_USB_HOTPLUG
	clk_enable(tegra->clk);
#endif
	return tegra_usb_resume(hcd, true);
}

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);
	int ret;

	if ((tegra->bus_suspended) && (tegra->power_down_on_bus_suspend)) {
#ifdef CONFIG_USB_HOTPLUG
		clk_disable(tegra->clk);
#endif
		return 0;
	}

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

	ret = tegra_usb_suspend(hcd, true);
#ifdef CONFIG_USB_HOTPLUG
	clk_disable(tegra->clk);
#endif
	return ret;
}
#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;
	/* make sure controller is on as we will touch its registers */
	if (!tegra->host_resumed)
		tegra_ehci_power_up(hcd, true);

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

#ifdef CONFIG_USB_EHCI_ONOFF_FEATURE
	if (tegra->phy->instance == 1) {
		remove_ehci_sys_file(hcd_to_ehci(hcd));
		ehci_handle = NULL;
	}
#endif

	/* Turn Off Interrupts */
	ehci_writel(tegra->ehci, 0, &tegra->ehci->regs->intr_enable);
	clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
	usb_remove_hcd(hcd);
	usb_put_hcd(hcd);
	cancel_delayed_work(&tegra->work);
	tegra_usb_phy_power_off(tegra->phy, true);
	tegra_usb_phy_close(tegra->phy);
	iounmap(hcd->regs);

	del_timer_sync(&tegra->clk_timer);
	del_timer_sync(&tegra->timer_device_detect);

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

	if (tegra->clock_enabled){
		clk_disable(tegra->sclk_clk);
		clk_disable(tegra->emc_clk);
	}
	clk_put(tegra->sclk_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",
	}
};