USB: Add Intel Langwell USB Device Controller driver

Intel Langwell USB Device Controller is a High-Speed USB OTG device
controller in Intel Moorestown platform. It can work in OTG device mode
with Intel Langwell USB OTG transceiver driver as well as device-only
mode. The number of programmable endpoints is different through
controller revision.

NOTE:
This patch is the first version Intel Langwell USB OTG device controller
driver. The bug fixing is on going for some hardware and software
issues.  Intel Langwell USB OTG transceiver driver and EHCI driver
patches will be submitted later.

Supported features:
 - USB OTG protocol support with Intel Langwell USB OTG transceiver
   driver (turn on CONFIG_USB_LANGWELL_OTG)
 - Support control, bulk, interrupt and isochronous endpoints
   (isochronous not tested)
 - PCI D0/D3 power management support
 - Link Power Management (LPM) support

Tested gadget drivers:
 - g_file_storage
 - g_ether
 - g_zero

The passed tests:
 - g_file_storage: USBCV Chapter 9 tests
 - g_file_storage: USBCV MSC tests
 - g_file_storage: from/to host files copying
 - g_ether: ping, ftp and scp files from/to host
 - Hotplug, with and without hubs

Known issues:
 - g_ether: failed part of USBCV chap9 tests
 - LPM support not fully tested

TODO:
 - g_ether: pass all USBCV chap9 tests
 - g_zero: pass usbtest tests
 - Stress tests on different gadget drivers
 - On-chip private SRAM caching support

Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

5 files changed, 3631 insertions, 0 deletions

diff --git a/drivers/usb/gadget/Kconfig b/drivers/usb/gadget/Kconfig
index ef9d9086cddc..5d1ddf485d1e 100644
--- a/drivers/usb/gadget/Kconfig
+++ b/drivers/usb/gadget/Kconfig
@@ -474,6 +474,27 @@ config USB_GOKU
 	default USB_GADGET
 	select USB_GADGET_SELECTED
 
+config USB_GADGET_LANGWELL
+	boolean "Intel Langwell USB Device Controller"
+	depends on PCI
+	select USB_GADGET_DUALSPEED
+	help
+	   Intel Langwell USB Device Controller is a High-Speed USB
+	   On-The-Go device controller.
+
+	   The number of programmable endpoints is different through
+	   controller revision.
+
+	   Say "y" to link the driver statically, or "m" to build a
+	   dynamically linked module called "langwell_udc" and force all
+	   gadget drivers to also be dynamically linked.
+
+config USB_LANGWELL
+	tristate
+	depends on USB_GADGET_LANGWELL
+	default USB_GADGET
+	select USB_GADGET_SELECTED
+
 
 #
 # LAST -- dummy/emulated controller
diff --git a/drivers/usb/gadget/Makefile b/drivers/usb/gadget/Makefile
index fc9a7dc01047..e6017e6bf6da 100644
--- a/drivers/usb/gadget/Makefile
+++ b/drivers/usb/gadget/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_USB_M66592)	+= m66592-udc.o
 obj-$(CONFIG_USB_FSL_QE)	+= fsl_qe_udc.o
 obj-$(CONFIG_USB_CI13XXX)	+= ci13xxx_udc.o
 obj-$(CONFIG_USB_S3C_HSOTG)	+= s3c-hsotg.o
+obj-$(CONFIG_USB_LANGWELL)	+= langwell_udc.o
 
 #
 # USB gadget drivers
diff --git a/drivers/usb/gadget/gadget_chips.h b/drivers/usb/gadget/gadget_chips.h
index ec6d439a2aa5..8e0e9a0b7364 100644
--- a/drivers/usb/gadget/gadget_chips.h
+++ b/drivers/usb/gadget/gadget_chips.h
@@ -137,6 +137,12 @@
 #define gadget_is_musbhdrc(g)	0
 #endif
 
+#ifdef CONFIG_USB_GADGET_LANGWELL
+#define gadget_is_langwell(g)	(!strcmp("langwell_udc", (g)->name))
+#else
+#define gadget_is_langwell(g)	0
+#endif
+
 /* from Montavista kernel (?) */
 #ifdef CONFIG_USB_GADGET_MPC8272
 #define gadget_is_mpc8272(g)	!strcmp("mpc8272_udc", (g)->name)
@@ -231,6 +237,8 @@ static inline int usb_gadget_controller_number(struct usb_gadget *gadget)
 		return 0x22;
 	else if (gadget_is_ci13xxx(gadget))
 		return 0x23;
+	else if (gadget_is_langwell(gadget))
+		return 0x24;
 	return -ENOENT;
 }
 
diff --git a/drivers/usb/gadget/langwell_udc.c b/drivers/usb/gadget/langwell_udc.c
new file mode 100644
index 000000000000..6829d5961359
--- /dev/null
+++ b/drivers/usb/gadget/langwell_udc.c
@@ -0,0 +1,3373 @@
+/*
+ * Intel Langwell USB Device Controller driver
+ * Copyright (C) 2008-2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+
+/* #undef	DEBUG */
+/* #undef	VERBOSE */
+
+#if defined(CONFIG_USB_LANGWELL_OTG)
+#define	OTG_TRANSCEIVER
+#endif
+
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/dma-mapping.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/usb/otg.h>
+#include <linux/pm.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <asm/system.h>
+#include <asm/unaligned.h>
+
+#include "langwell_udc.h"
+
+
+#define	DRIVER_DESC		"Intel Langwell USB Device Controller driver"
+#define	DRIVER_VERSION		"16 May 2009"
+
+static const char driver_name[] = "langwell_udc";
+static const char driver_desc[] = DRIVER_DESC;
+
+
+/* controller device global variable */
+static struct langwell_udc	*the_controller;
+
+/* for endpoint 0 operations */
+static const struct usb_endpoint_descriptor
+langwell_ep0_desc = {
+	.bLength =		USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType =	USB_DT_ENDPOINT,
+	.bEndpointAddress =	0,
+	.bmAttributes =		USB_ENDPOINT_XFER_CONTROL,
+	.wMaxPacketSize =	EP0_MAX_PKT_SIZE,
+};
+
+
+/*-------------------------------------------------------------------------*/
+/* debugging */
+
+#ifdef	DEBUG
+#define	DBG(dev, fmt, args...) \
+	pr_debug("%s %s: " fmt , driver_name, \
+			pci_name(dev->pdev), ## args)
+#else
+#define	DBG(dev, fmt, args...) \
+	do { } while (0)
+#endif /* DEBUG */
+
+
+#ifdef	VERBOSE
+#define	VDBG DBG
+#else
+#define	VDBG(dev, fmt, args...) \
+	do { } while (0)
+#endif	/* VERBOSE */
+
+
+#define	ERROR(dev, fmt, args...) \
+	pr_err("%s %s: " fmt , driver_name, \
+			pci_name(dev->pdev), ## args)
+
+#define	WARNING(dev, fmt, args...) \
+	pr_warning("%s %s: " fmt , driver_name, \
+			pci_name(dev->pdev), ## args)
+
+#define	INFO(dev, fmt, args...) \
+	pr_info("%s %s: " fmt , driver_name, \
+			pci_name(dev->pdev), ## args)
+
+
+#ifdef	VERBOSE
+static inline void print_all_registers(struct langwell_udc *dev)
+{
+	int	i;
+
+	/* Capability Registers */
+	printk(KERN_DEBUG "Capability Registers (offset: "
+			"0x%04x, length: 0x%08x)\n",
+			CAP_REG_OFFSET,
+			(u32)sizeof(struct langwell_cap_regs));
+	printk(KERN_DEBUG "caplength=0x%02x\n",
+			readb(&dev->cap_regs->caplength));
+	printk(KERN_DEBUG "hciversion=0x%04x\n",
+			readw(&dev->cap_regs->hciversion));
+	printk(KERN_DEBUG "hcsparams=0x%08x\n",
+			readl(&dev->cap_regs->hcsparams));
+	printk(KERN_DEBUG "hccparams=0x%08x\n",
+			readl(&dev->cap_regs->hccparams));
+	printk(KERN_DEBUG "dciversion=0x%04x\n",
+			readw(&dev->cap_regs->dciversion));
+	printk(KERN_DEBUG "dccparams=0x%08x\n",
+			readl(&dev->cap_regs->dccparams));
+
+	/* Operational Registers */
+	printk(KERN_DEBUG "Operational Registers (offset: "
+			"0x%04x, length: 0x%08x)\n",
+			OP_REG_OFFSET,
+			(u32)sizeof(struct langwell_op_regs));
+	printk(KERN_DEBUG "extsts=0x%08x\n",
+			readl(&dev->op_regs->extsts));
+	printk(KERN_DEBUG "extintr=0x%08x\n",
+			readl(&dev->op_regs->extintr));
+	printk(KERN_DEBUG "usbcmd=0x%08x\n",
+			readl(&dev->op_regs->usbcmd));
+	printk(KERN_DEBUG "usbsts=0x%08x\n",
+			readl(&dev->op_regs->usbsts));
+	printk(KERN_DEBUG "usbintr=0x%08x\n",
+			readl(&dev->op_regs->usbintr));
+	printk(KERN_DEBUG "frindex=0x%08x\n",
+			readl(&dev->op_regs->frindex));
+	printk(KERN_DEBUG "ctrldssegment=0x%08x\n",
+			readl(&dev->op_regs->ctrldssegment));
+	printk(KERN_DEBUG "deviceaddr=0x%08x\n",
+			readl(&dev->op_regs->deviceaddr));
+	printk(KERN_DEBUG "endpointlistaddr=0x%08x\n",
+			readl(&dev->op_regs->endpointlistaddr));
+	printk(KERN_DEBUG "ttctrl=0x%08x\n",
+			readl(&dev->op_regs->ttctrl));
+	printk(KERN_DEBUG "burstsize=0x%08x\n",
+			readl(&dev->op_regs->burstsize));
+	printk(KERN_DEBUG "txfilltuning=0x%08x\n",
+			readl(&dev->op_regs->txfilltuning));
+	printk(KERN_DEBUG "txttfilltuning=0x%08x\n",
+			readl(&dev->op_regs->txttfilltuning));
+	printk(KERN_DEBUG "ic_usb=0x%08x\n",
+			readl(&dev->op_regs->ic_usb));
+	printk(KERN_DEBUG "ulpi_viewport=0x%08x\n",
+			readl(&dev->op_regs->ulpi_viewport));
+	printk(KERN_DEBUG "configflag=0x%08x\n",
+			readl(&dev->op_regs->configflag));
+	printk(KERN_DEBUG "portsc1=0x%08x\n",
+			readl(&dev->op_regs->portsc1));
+	printk(KERN_DEBUG "devlc=0x%08x\n",
+			readl(&dev->op_regs->devlc));
+	printk(KERN_DEBUG "otgsc=0x%08x\n",
+			readl(&dev->op_regs->otgsc));
+	printk(KERN_DEBUG "usbmode=0x%08x\n",
+			readl(&dev->op_regs->usbmode));
+	printk(KERN_DEBUG "endptnak=0x%08x\n",
+			readl(&dev->op_regs->endptnak));
+	printk(KERN_DEBUG "endptnaken=0x%08x\n",
+			readl(&dev->op_regs->endptnaken));
+	printk(KERN_DEBUG "endptsetupstat=0x%08x\n",
+			readl(&dev->op_regs->endptsetupstat));
+	printk(KERN_DEBUG "endptprime=0x%08x\n",
+			readl(&dev->op_regs->endptprime));
+	printk(KERN_DEBUG "endptflush=0x%08x\n",
+			readl(&dev->op_regs->endptflush));
+	printk(KERN_DEBUG "endptstat=0x%08x\n",
+			readl(&dev->op_regs->endptstat));
+	printk(KERN_DEBUG "endptcomplete=0x%08x\n",
+			readl(&dev->op_regs->endptcomplete));
+
+	for (i = 0; i < dev->ep_max / 2; i++) {
+		printk(KERN_DEBUG "endptctrl[%d]=0x%08x\n",
+				i, readl(&dev->op_regs->endptctrl[i]));
+	}
+}
+#endif /* VERBOSE */
+
+
+/*-------------------------------------------------------------------------*/
+
+#define	DIR_STRING(bAddress)	(((bAddress) & USB_DIR_IN) ? "in" : "out")
+
+#define is_in(ep)	(((ep)->ep_num == 0) ? ((ep)->dev->ep0_dir == \
+			USB_DIR_IN) : ((ep)->desc->bEndpointAddress \
+			& USB_DIR_IN) == USB_DIR_IN)
+
+
+#ifdef	DEBUG
+static char *type_string(u8 bmAttributes)
+{
+	switch ((bmAttributes) & USB_ENDPOINT_XFERTYPE_MASK) {
+	case USB_ENDPOINT_XFER_BULK:
+		return "bulk";
+	case USB_ENDPOINT_XFER_ISOC:
+		return "iso";
+	case USB_ENDPOINT_XFER_INT:
+		return "int";
+	};
+
+	return "control";
+}
+#endif
+
+
+/* configure endpoint control registers */
+static void ep_reset(struct langwell_ep *ep, unsigned char ep_num,
+		unsigned char is_in, unsigned char ep_type)
+{
+	struct langwell_udc	*dev;
+	u32			endptctrl;
+
+	dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	endptctrl = readl(&dev->op_regs->endptctrl[ep_num]);
+	if (is_in) {	/* TX */
+		if (ep_num)
+			endptctrl |= EPCTRL_TXR;
+		endptctrl |= EPCTRL_TXE;
+		endptctrl |= ep_type << EPCTRL_TXT_SHIFT;
+	} else {	/* RX */
+		if (ep_num)
+			endptctrl |= EPCTRL_RXR;
+		endptctrl |= EPCTRL_RXE;
+		endptctrl |= ep_type << EPCTRL_RXT_SHIFT;
+	}
+
+	writel(endptctrl, &dev->op_regs->endptctrl[ep_num]);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* reset ep0 dQH and endptctrl */
+static void ep0_reset(struct langwell_udc *dev)
+{
+	struct langwell_ep	*ep;
+	int			i;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* ep0 in and out */
+	for (i = 0; i < 2; i++) {
+		ep = &dev->ep[i];
+		ep->dev = dev;
+
+		/* ep0 dQH */
+		ep->dqh = &dev->ep_dqh[i];
+
+		/* configure ep0 endpoint capabilities in dQH */
+		ep->dqh->dqh_ios = 1;
+		ep->dqh->dqh_mpl = EP0_MAX_PKT_SIZE;
+
+		/* FIXME: enable ep0-in HW zero length termination select */
+		if (is_in(ep))
+			ep->dqh->dqh_zlt = 0;
+		ep->dqh->dqh_mult = 0;
+
+		/* configure ep0 control registers */
+		ep_reset(&dev->ep[0], 0, i, USB_ENDPOINT_XFER_CONTROL);
+	}
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* endpoints operations */
+
+/* configure endpoint, making it usable */
+static int langwell_ep_enable(struct usb_ep *_ep,
+		const struct usb_endpoint_descriptor *desc)
+{
+	struct langwell_udc	*dev;
+	struct langwell_ep	*ep;
+	u16			max = 0;
+	unsigned long		flags;
+	int			retval = 0;
+	unsigned char		zlt, ios = 0, mult = 0;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (!_ep || !desc || ep->desc
+			|| desc->bDescriptorType != USB_DT_ENDPOINT)
+		return -EINVAL;
+
+	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
+		return -ESHUTDOWN;
+
+	max = le16_to_cpu(desc->wMaxPacketSize);
+
+	/*
+	 * disable HW zero length termination select
+	 * driver handles zero length packet through req->req.zero
+	 */
+	zlt = 1;
+
+	/*
+	 * sanity check type, direction, address, and then
+	 * initialize the endpoint capabilities fields in dQH
+	 */
+	switch (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		ios = 1;
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		if ((dev->gadget.speed == USB_SPEED_HIGH
+					&& max != 512)
+				|| (dev->gadget.speed == USB_SPEED_FULL
+					&& max > 64)) {
+			goto done;
+		}
+		break;
+	case USB_ENDPOINT_XFER_INT:
+		if (strstr(ep->ep.name, "-iso")) /* bulk is ok */
+			goto done;
+
+		switch (dev->gadget.speed) {
+		case USB_SPEED_HIGH:
+			if (max <= 1024)
+				break;
+		case USB_SPEED_FULL:
+			if (max <= 64)
+				break;
+		default:
+			if (max <= 8)
+				break;
+			goto done;
+		}
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		if (strstr(ep->ep.name, "-bulk")
+				|| strstr(ep->ep.name, "-int"))
+			goto done;
+
+		switch (dev->gadget.speed) {
+		case USB_SPEED_HIGH:
+			if (max <= 1024)
+				break;
+		case USB_SPEED_FULL:
+			if (max <= 1023)
+				break;
+		default:
+			goto done;
+		}
+		/*
+		 * FIXME:
+		 * calculate transactions needed for high bandwidth iso
+		 */
+		mult = (unsigned char)(1 + ((max >> 11) & 0x03));
+		max = max & 0x8ff;	/* bit 0~10 */
+		/* 3 transactions at most */
+		if (mult > 3)
+			goto done;
+		break;
+	default:
+		goto done;
+	}
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* configure endpoint capabilities in dQH */
+	ep->dqh->dqh_ios = ios;
+	ep->dqh->dqh_mpl = cpu_to_le16(max);
+	ep->dqh->dqh_zlt = zlt;
+	ep->dqh->dqh_mult = mult;
+
+	ep->ep.maxpacket = max;
+	ep->desc = desc;
+	ep->stopped = 0;
+	ep->ep_num = desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
+
+	/* ep_type */
+	ep->ep_type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
+
+	/* configure endpoint control registers */
+	ep_reset(ep, ep->ep_num, is_in(ep), ep->ep_type);
+
+	DBG(dev, "enabled %s (ep%d%s-%s), max %04x\n",
+			_ep->name,
+			ep->ep_num,
+			DIR_STRING(desc->bEndpointAddress),
+			type_string(desc->bmAttributes),
+			max);
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+done:
+	VDBG(dev, "<--- %s()\n", __func__);
+	return retval;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* retire a request */
+static void done(struct langwell_ep *ep, struct langwell_request *req,
+		int status)
+{
+	struct langwell_udc	*dev = ep->dev;
+	unsigned		stopped = ep->stopped;
+	struct langwell_dtd	*curr_dtd, *next_dtd;
+	int			i;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* remove the req from ep->queue */
+	list_del_init(&req->queue);
+
+	if (req->req.status == -EINPROGRESS)
+		req->req.status = status;
+	else
+		status = req->req.status;
+
+	/* free dTD for the request */
+	next_dtd = req->head;
+	for (i = 0; i < req->dtd_count; i++) {
+		curr_dtd = next_dtd;
+		if (i != req->dtd_count - 1)
+			next_dtd = curr_dtd->next_dtd_virt;
+		dma_pool_free(dev->dtd_pool, curr_dtd, curr_dtd->dtd_dma);
+	}
+
+	if (req->mapped) {
+		dma_unmap_single(&dev->pdev->dev, req->req.dma, req->req.length,
+			is_in(ep) ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
+		req->req.dma = DMA_ADDR_INVALID;
+		req->mapped = 0;
+	} else
+		dma_sync_single_for_cpu(&dev->pdev->dev, req->req.dma,
+				req->req.length,
+				is_in(ep) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+
+	if (status != -ESHUTDOWN)
+		DBG(dev, "complete %s, req %p, stat %d, len %u/%u\n",
+			ep->ep.name, &req->req, status,
+			req->req.actual, req->req.length);
+
+	/* don't modify queue heads during completion callback */
+	ep->stopped = 1;
+
+	spin_unlock(&dev->lock);
+	/* complete routine from gadget driver */
+	if (req->req.complete)
+		req->req.complete(&ep->ep, &req->req);
+
+	spin_lock(&dev->lock);
+	ep->stopped = stopped;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+static void langwell_ep_fifo_flush(struct usb_ep *_ep);
+
+/* delete all endpoint requests, called with spinlock held */
+static void nuke(struct langwell_ep *ep, int status)
+{
+	/* called with spinlock held */
+	ep->stopped = 1;
+
+	/* endpoint fifo flush */
+	if (&ep->ep && ep->desc)
+		langwell_ep_fifo_flush(&ep->ep);
+
+	while (!list_empty(&ep->queue)) {
+		struct langwell_request	*req = NULL;
+		req = list_entry(ep->queue.next, struct langwell_request,
+				queue);
+		done(ep, req, status);
+	}
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* endpoint is no longer usable */
+static int langwell_ep_disable(struct usb_ep *_ep)
+{
+	struct langwell_ep	*ep;
+	unsigned long		flags;
+	struct langwell_udc	*dev;
+	int			ep_num;
+	u32			endptctrl;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (!_ep || !ep->desc)
+		return -EINVAL;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* disable endpoint control register */
+	ep_num = ep->ep_num;
+	endptctrl = readl(&dev->op_regs->endptctrl[ep_num]);
+	if (is_in(ep))
+		endptctrl &= ~EPCTRL_TXE;
+	else
+		endptctrl &= ~EPCTRL_RXE;
+	writel(endptctrl, &dev->op_regs->endptctrl[ep_num]);
+
+	/* nuke all pending requests (does flush) */
+	nuke(ep, -ESHUTDOWN);
+
+	ep->desc = NULL;
+	ep->stopped = 1;
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	DBG(dev, "disabled %s\n", _ep->name);
+	VDBG(dev, "<--- %s()\n", __func__);
+
+	return 0;
+}
+
+
+/* allocate a request object to use with this endpoint */
+static struct usb_request *langwell_alloc_request(struct usb_ep *_ep,
+		gfp_t gfp_flags)
+{
+	struct langwell_ep	*ep;
+	struct langwell_udc	*dev;
+	struct langwell_request	*req = NULL;
+
+	if (!_ep)
+		return NULL;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	req = kzalloc(sizeof(*req), gfp_flags);
+	if (!req)
+		return NULL;
+
+	req->req.dma = DMA_ADDR_INVALID;
+	INIT_LIST_HEAD(&req->queue);
+
+	VDBG(dev, "alloc request for %s\n", _ep->name);
+	VDBG(dev, "<--- %s()\n", __func__);
+	return &req->req;
+}
+
+
+/* free a request object */
+static void langwell_free_request(struct usb_ep *_ep,
+		struct usb_request *_req)
+{
+	struct langwell_ep	*ep;
+	struct langwell_udc	*dev;
+	struct langwell_request	*req = NULL;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (!_ep || !_req)
+		return;
+
+	req = container_of(_req, struct langwell_request, req);
+	WARN_ON(!list_empty(&req->queue));
+
+	if (_req)
+		kfree(req);
+
+	VDBG(dev, "free request for %s\n", _ep->name);
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* queue dTD and PRIME endpoint */
+static int queue_dtd(struct langwell_ep *ep, struct langwell_request *req)
+{
+	u32			bit_mask, usbcmd, endptstat, dtd_dma;
+	u8			dtd_status;
+	int			i;
+	struct langwell_dqh	*dqh;
+	struct langwell_udc	*dev;
+
+	dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	i = ep->ep_num * 2 + is_in(ep);
+	dqh = &dev->ep_dqh[i];
+
+	if (ep->ep_num)
+		VDBG(dev, "%s\n", ep->name);
+	else
+		/* ep0 */
+		VDBG(dev, "%s-%s\n", ep->name, is_in(ep) ? "in" : "out");
+
+	VDBG(dev, "ep_dqh[%d] addr: 0x%08x\n", i, (u32)&(dev->ep_dqh[i]));
+
+	bit_mask = is_in(ep) ?
+		(1 << (ep->ep_num + 16)) : (1 << (ep->ep_num));
+
+	VDBG(dev, "bit_mask = 0x%08x\n", bit_mask);
+
+	/* check if the pipe is empty */
+	if (!(list_empty(&ep->queue))) {
+		/* add dTD to the end of linked list */
+		struct langwell_request	*lastreq;
+		lastreq = list_entry(ep->queue.prev,
+				struct langwell_request, queue);
+
+		lastreq->tail->dtd_next =
+			cpu_to_le32(req->head->dtd_dma & DTD_NEXT_MASK);
+
+		/* read prime bit, if 1 goto out */
+		if (readl(&dev->op_regs->endptprime) & bit_mask)
+			goto out;
+
+		do {
+			/* set ATDTW bit in USBCMD */
+			usbcmd = readl(&dev->op_regs->usbcmd);
+			writel(usbcmd | CMD_ATDTW, &dev->op_regs->usbcmd);
+
+			/* read correct status bit */
+			endptstat = readl(&dev->op_regs->endptstat) & bit_mask;
+
+		} while (!(readl(&dev->op_regs->usbcmd) & CMD_ATDTW));
+
+		/* write ATDTW bit to 0 */
+		usbcmd = readl(&dev->op_regs->usbcmd);
+		writel(usbcmd & ~CMD_ATDTW, &dev->op_regs->usbcmd);
+
+		if (endptstat)
+			goto out;
+	}
+
+	/* write dQH next pointer and terminate bit to 0 */
+	dtd_dma = req->head->dtd_dma & DTD_NEXT_MASK;
+	dqh->dtd_next = cpu_to_le32(dtd_dma);
+
+	/* clear active and halt bit */
+	dtd_status = (u8) ~(DTD_STS_ACTIVE | DTD_STS_HALTED);
+	dqh->dtd_status &= dtd_status;
+	VDBG(dev, "dqh->dtd_status = 0x%x\n", dqh->dtd_status);
+
+	/* write 1 to endptprime register to PRIME endpoint */
+	bit_mask = is_in(ep) ? (1 << (ep->ep_num + 16)) : (1 << ep->ep_num);
+	VDBG(dev, "endprime bit_mask = 0x%08x\n", bit_mask);
+	writel(bit_mask, &dev->op_regs->endptprime);
+out:
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* fill in the dTD structure to build a transfer descriptor */
+static struct langwell_dtd *build_dtd(struct langwell_request *req,
+		unsigned *length, dma_addr_t *dma, int *is_last)
+{
+	u32			 buf_ptr;
+	struct langwell_dtd	*dtd;
+	struct langwell_udc	*dev;
+	int			i;
+
+	dev = req->ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* the maximum transfer length, up to 16k bytes */
+	*length = min(req->req.length - req->req.actual,
+			(unsigned)DTD_MAX_TRANSFER_LENGTH);
+
+	/* create dTD dma_pool resource */
+	dtd = dma_pool_alloc(dev->dtd_pool, GFP_KERNEL, dma);
+	if (dtd == NULL)
+		return dtd;
+	dtd->dtd_dma = *dma;
+
+	/* initialize buffer page pointers */
+	buf_ptr = (u32)(req->req.dma + req->req.actual);
+	for (i = 0; i < 5; i++)
+		dtd->dtd_buf[i] = cpu_to_le32(buf_ptr + i * PAGE_SIZE);
+
+	req->req.actual += *length;
+
+	/* fill in total bytes with transfer size */
+	dtd->dtd_total = cpu_to_le16(*length);
+	VDBG(dev, "dtd->dtd_total = %d\n", dtd->dtd_total);
+
+	/* set is_last flag if req->req.zero is set or not */
+	if (req->req.zero) {
+		if (*length == 0 || (*length % req->ep->ep.maxpacket) != 0)
+			*is_last = 1;
+		else
+			*is_last = 0;
+	} else if (req->req.length == req->req.actual) {
+		*is_last = 1;
+	} else
+		*is_last = 0;
+
+	if (*is_last == 0)
+		VDBG(dev, "multi-dtd request!\n");
+
+	/* set interrupt on complete bit for the last dTD */
+	if (*is_last && !req->req.no_interrupt)
+		dtd->dtd_ioc = 1;
+
+	/* set multiplier override 0 for non-ISO and non-TX endpoint */
+	dtd->dtd_multo = 0;
+
+	/* set the active bit of status field to 1 */
+	dtd->dtd_status = DTD_STS_ACTIVE;
+	VDBG(dev, "dtd->dtd_status = 0x%02x\n", dtd->dtd_status);
+
+	VDBG(dev, "length = %d, dma addr= 0x%08x\n", *length, (int)*dma);
+	VDBG(dev, "<--- %s()\n", __func__);
+	return dtd;
+}
+
+
+/* generate dTD linked list for a request */
+static int req_to_dtd(struct langwell_request *req)
+{
+	unsigned		count;
+	int			is_last, is_first = 1;
+	struct langwell_dtd	*dtd, *last_dtd = NULL;
+	struct langwell_udc	*dev;
+	dma_addr_t		dma;
+
+	dev = req->ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+	do {
+		dtd = build_dtd(req, &count, &dma, &is_last);
+		if (dtd == NULL)
+			return -ENOMEM;
+
+		if (is_first) {
+			is_first = 0;
+			req->head = dtd;
+		} else {
+			last_dtd->dtd_next = cpu_to_le32(dma);
+			last_dtd->next_dtd_virt = dtd;
+		}
+		last_dtd = dtd;
+		req->dtd_count++;
+	} while (!is_last);
+
+	/* set terminate bit to 1 for the last dTD */
+	dtd->dtd_next = DTD_TERM;
+
+	req->tail = dtd;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* queue (submits) an I/O requests to an endpoint */
+static int langwell_ep_queue(struct usb_ep *_ep, struct usb_request *_req,
+		gfp_t gfp_flags)
+{
+	struct langwell_request	*req;
+	struct langwell_ep	*ep;
+	struct langwell_udc	*dev;
+	unsigned long		flags;
+	int			is_iso = 0, zlflag = 0;
+
+	/* always require a cpu-view buffer */
+	req = container_of(_req, struct langwell_request, req);
+	ep = container_of(_ep, struct langwell_ep, ep);
+
+	if (!_req || !_req->complete || !_req->buf
+			|| !list_empty(&req->queue)) {
+		return -EINVAL;
+	}
+
+	if (unlikely(!_ep || !ep->desc))
+		return -EINVAL;
+
+	dev = ep->dev;
+	req->ep = ep;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (ep->desc->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
+		if (req->req.length > ep->ep.maxpacket)
+			return -EMSGSIZE;
+		is_iso = 1;
+	}
+
+	if (unlikely(!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN))
+		return -ESHUTDOWN;
+
+	/* set up dma mapping in case the caller didn't */
+	if (_req->dma == DMA_ADDR_INVALID) {
+		/* WORKAROUND: WARN_ON(size == 0) */
+		if (_req->length == 0) {
+			VDBG(dev, "req->length: 0->1\n");
+			zlflag = 1;
+			_req->length++;
+		}
+
+		_req->dma = dma_map_single(&dev->pdev->dev,
+				_req->buf, _req->length,
+				is_in(ep) ? DMA_TO_DEVICE : DMA_FROM_DEVICE);
+		if (zlflag && (_req->length == 1)) {
+			VDBG(dev, "req->length: 1->0\n");
+			zlflag = 0;
+			_req->length = 0;
+		}
+
+		req->mapped = 1;
+		VDBG(dev, "req->mapped = 1\n");
+	} else {
+		dma_sync_single_for_device(&dev->pdev->dev,
+				_req->dma, _req->length,
+				is_in(ep) ?  DMA_TO_DEVICE : DMA_FROM_DEVICE);
+		req->mapped = 0;
+		VDBG(dev, "req->mapped = 0\n");
+	}
+
+	DBG(dev, "%s queue req %p, len %u, buf %p, dma 0x%08x\n",
+			_ep->name,
+			_req, _req->length, _req->buf, _req->dma);
+
+	_req->status = -EINPROGRESS;
+	_req->actual = 0;
+	req->dtd_count = 0;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* build and put dTDs to endpoint queue */
+	if (!req_to_dtd(req)) {
+		queue_dtd(ep, req);
+	} else {
+		spin_unlock_irqrestore(&dev->lock, flags);
+		return -ENOMEM;
+	}
+
+	/* update ep0 state */
+	if (ep->ep_num == 0)
+		dev->ep0_state = DATA_STATE_XMIT;
+
+	if (likely(req != NULL)) {
+		list_add_tail(&req->queue, &ep->queue);
+		VDBG(dev, "list_add_tail() \n");
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* dequeue (cancels, unlinks) an I/O request from an endpoint */
+static int langwell_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct langwell_ep	*ep;
+	struct langwell_udc	*dev;
+	struct langwell_request	*req;
+	unsigned long		flags;
+	int			stopped, ep_num, retval = 0;
+	u32			endptctrl;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (!_ep || !ep->desc || !_req)
+		return -EINVAL;
+
+	if (!dev->driver)
+		return -ESHUTDOWN;
+
+	spin_lock_irqsave(&dev->lock, flags);
+	stopped = ep->stopped;
+
+	/* quiesce dma while we patch the queue */
+	ep->stopped = 1;
+	ep_num = ep->ep_num;
+
+	/* disable endpoint control register */
+	endptctrl = readl(&dev->op_regs->endptctrl[ep_num]);
+	if (is_in(ep))
+		endptctrl &= ~EPCTRL_TXE;
+	else
+		endptctrl &= ~EPCTRL_RXE;
+	writel(endptctrl, &dev->op_regs->endptctrl[ep_num]);
+
+	/* make sure it's still queued on this endpoint */
+	list_for_each_entry(req, &ep->queue, queue) {
+		if (&req->req == _req)
+			break;
+	}
+
+	if (&req->req != _req) {
+		retval = -EINVAL;
+		goto done;
+	}
+
+	/* queue head may be partially complete. */
+	if (ep->queue.next == &req->queue) {
+		DBG(dev, "unlink (%s) dma\n", _ep->name);
+		_req->status = -ECONNRESET;
+		langwell_ep_fifo_flush(&ep->ep);
+
+		/* not the last request in endpoint queue */
+		if (likely(ep->queue.next == &req->queue)) {
+			struct langwell_dqh	*dqh;
+			struct langwell_request	*next_req;
+
+			dqh = ep->dqh;
+			next_req = list_entry(req->queue.next,
+					struct langwell_request, queue);
+
+			/* point the dQH to the first dTD of next request */
+			writel((u32) next_req->head, &dqh->dqh_current);
+		}
+	} else {
+		struct langwell_request	*prev_req;
+
+		prev_req = list_entry(req->queue.prev,
+				struct langwell_request, queue);
+		writel(readl(&req->tail->dtd_next),
+				&prev_req->tail->dtd_next);
+	}
+
+	done(ep, req, -ECONNRESET);
+
+done:
+	/* enable endpoint again */
+	endptctrl = readl(&dev->op_regs->endptctrl[ep_num]);
+	if (is_in(ep))
+		endptctrl |= EPCTRL_TXE;
+	else
+		endptctrl |= EPCTRL_RXE;
+	writel(endptctrl, &dev->op_regs->endptctrl[ep_num]);
+
+	ep->stopped = stopped;
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return retval;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* endpoint set/clear halt */
+static void ep_set_halt(struct langwell_ep *ep, int value)
+{
+	u32			endptctrl = 0;
+	int			ep_num;
+	struct langwell_udc	*dev = ep->dev;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	ep_num = ep->ep_num;
+	endptctrl = readl(&dev->op_regs->endptctrl[ep_num]);
+
+	/* value: 1 - set halt, 0 - clear halt */
+	if (value) {
+		/* set the stall bit */
+		if (is_in(ep))
+			endptctrl |= EPCTRL_TXS;
+		else
+			endptctrl |= EPCTRL_RXS;
+	} else {
+		/* clear the stall bit and reset data toggle */
+		if (is_in(ep)) {
+			endptctrl &= ~EPCTRL_TXS;
+			endptctrl |= EPCTRL_TXR;
+		} else {
+			endptctrl &= ~EPCTRL_RXS;
+			endptctrl |= EPCTRL_RXR;
+		}
+	}
+
+	writel(endptctrl, &dev->op_regs->endptctrl[ep_num]);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* set the endpoint halt feature */
+static int langwell_ep_set_halt(struct usb_ep *_ep, int value)
+{
+	struct langwell_ep	*ep;
+	struct langwell_udc	*dev;
+	unsigned long		flags;
+	int			retval = 0;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (!_ep || !ep->desc)
+		return -EINVAL;
+
+	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
+		return -ESHUTDOWN;
+
+	if (ep->desc && (ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
+			== USB_ENDPOINT_XFER_ISOC)
+		return  -EOPNOTSUPP;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/*
+	 * attempt to halt IN ep will fail if any transfer requests
+	 * are still queue
+	 */
+	if (!list_empty(&ep->queue) && is_in(ep) && value) {
+		/* IN endpoint FIFO holds bytes */
+		DBG(dev, "%s FIFO holds bytes\n", _ep->name);
+		retval = -EAGAIN;
+		goto done;
+	}
+
+	/* endpoint set/clear halt */
+	if (ep->ep_num) {
+		ep_set_halt(ep, value);
+	} else { /* endpoint 0 */
+		dev->ep0_state = WAIT_FOR_SETUP;
+		dev->ep0_dir = USB_DIR_OUT;
+	}
+done:
+	spin_unlock_irqrestore(&dev->lock, flags);
+	DBG(dev, "%s %s halt\n", _ep->name, value ? "set" : "clear");
+	VDBG(dev, "<--- %s()\n", __func__);
+	return retval;
+}
+
+
+/* set the halt feature and ignores clear requests */
+static int langwell_ep_set_wedge(struct usb_ep *_ep)
+{
+	struct langwell_ep	*ep;
+	struct langwell_udc	*dev;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (!_ep || !ep->desc)
+		return -EINVAL;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return usb_ep_set_halt(_ep);
+}
+
+
+/* flush contents of a fifo */
+static void langwell_ep_fifo_flush(struct usb_ep *_ep)
+{
+	struct langwell_ep	*ep;
+	struct langwell_udc	*dev;
+	u32			flush_bit;
+	unsigned long		timeout;
+
+	ep = container_of(_ep, struct langwell_ep, ep);
+	dev = ep->dev;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (!_ep || !ep->desc) {
+		VDBG(dev, "ep or ep->desc is NULL\n");
+		VDBG(dev, "<--- %s()\n", __func__);
+		return;
+	}
+
+	VDBG(dev, "%s-%s fifo flush\n", _ep->name, is_in(ep) ? "in" : "out");
+
+	/* flush endpoint buffer */
+	if (ep->ep_num == 0)
+		flush_bit = (1 << 16) | 1;
+	else if (is_in(ep))
+		flush_bit = 1 << (ep->ep_num + 16);	/* TX */
+	else
+		flush_bit = 1 << ep->ep_num;		/* RX */
+
+	/* wait until flush complete */
+	timeout = jiffies + FLUSH_TIMEOUT;
+	do {
+		writel(flush_bit, &dev->op_regs->endptflush);
+		while (readl(&dev->op_regs->endptflush)) {
+			if (time_after(jiffies, timeout)) {
+				ERROR(dev, "ep flush timeout\n");
+				goto done;
+			}
+			cpu_relax();
+		}
+	} while (readl(&dev->op_regs->endptstat) & flush_bit);
+done:
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* endpoints operations structure */
+static const struct usb_ep_ops langwell_ep_ops = {
+
+	/* configure endpoint, making it usable */
+	.enable		= langwell_ep_enable,
+
+	/* endpoint is no longer usable */
+	.disable	= langwell_ep_disable,
+
+	/* allocate a request object to use with this endpoint */
+	.alloc_request	= langwell_alloc_request,
+
+	/* free a request object */
+	.free_request	= langwell_free_request,
+
+	/* queue (submits) an I/O requests to an endpoint */
+	.queue		= langwell_ep_queue,
+
+	/* dequeue (cancels, unlinks) an I/O request from an endpoint */
+	.dequeue	= langwell_ep_dequeue,
+
+	/* set the endpoint halt feature */
+	.set_halt	= langwell_ep_set_halt,
+
+	/* set the halt feature and ignores clear requests */
+	.set_wedge	= langwell_ep_set_wedge,
+
+	/* flush contents of a fifo */
+	.fifo_flush	= langwell_ep_fifo_flush,
+};
+
+
+/*-------------------------------------------------------------------------*/
+
+/* device controller usb_gadget_ops structure */
+
+/* returns the current frame number */
+static int langwell_get_frame(struct usb_gadget *_gadget)
+{
+	struct langwell_udc	*dev;
+	u16			retval;
+
+	if (!_gadget)
+		return -ENODEV;
+
+	dev = container_of(_gadget, struct langwell_udc, gadget);
+	VDBG(dev, "---> %s()\n", __func__);
+
+	retval = readl(&dev->op_regs->frindex) & FRINDEX_MASK;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return retval;
+}
+
+
+/* tries to wake up the host connected to this gadget */
+static int langwell_wakeup(struct usb_gadget *_gadget)
+{
+	struct langwell_udc	*dev;
+	u32 			portsc1, devlc;
+	unsigned long   	flags;
+
+	if (!_gadget)
+		return 0;
+
+	dev = container_of(_gadget, struct langwell_udc, gadget);
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* Remote Wakeup feature not enabled by host */
+	if (!dev->remote_wakeup)
+		return -ENOTSUPP;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	portsc1 = readl(&dev->op_regs->portsc1);
+	if (!(portsc1 & PORTS_SUSP)) {
+		spin_unlock_irqrestore(&dev->lock, flags);
+		return 0;
+	}
+
+	/* LPM L1 to L0, remote wakeup */
+	if (dev->lpm && dev->lpm_state == LPM_L1) {
+		portsc1 |= PORTS_SLP;
+		writel(portsc1, &dev->op_regs->portsc1);
+	}
+
+	/* force port resume */
+	if (dev->usb_state == USB_STATE_SUSPENDED) {
+		portsc1 |= PORTS_FPR;
+		writel(portsc1, &dev->op_regs->portsc1);
+	}
+
+	/* exit PHY low power suspend */
+	devlc = readl(&dev->op_regs->devlc);
+	VDBG(dev, "devlc = 0x%08x\n", devlc);
+	devlc &= ~LPM_PHCD;
+	writel(devlc, &dev->op_regs->devlc);
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* notify controller that VBUS is powered or not */
+static int langwell_vbus_session(struct usb_gadget *_gadget, int is_active)
+{
+	struct langwell_udc	*dev;
+	unsigned long		flags;
+	u32             	usbcmd;
+
+	if (!_gadget)
+		return -ENODEV;
+
+	dev = container_of(_gadget, struct langwell_udc, gadget);
+	VDBG(dev, "---> %s()\n", __func__);
+
+	spin_lock_irqsave(&dev->lock, flags);
+	VDBG(dev, "VBUS status: %s\n", is_active ? "on" : "off");
+
+	dev->vbus_active = (is_active != 0);
+	if (dev->driver && dev->softconnected && dev->vbus_active) {
+		usbcmd = readl(&dev->op_regs->usbcmd);
+		usbcmd |= CMD_RUNSTOP;
+		writel(usbcmd, &dev->op_regs->usbcmd);
+	} else {
+		usbcmd = readl(&dev->op_regs->usbcmd);
+		usbcmd &= ~CMD_RUNSTOP;
+		writel(usbcmd, &dev->op_regs->usbcmd);
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* constrain controller's VBUS power usage */
+static int langwell_vbus_draw(struct usb_gadget *_gadget, unsigned mA)
+{
+	struct langwell_udc	*dev;
+
+	if (!_gadget)
+		return -ENODEV;
+
+	dev = container_of(_gadget, struct langwell_udc, gadget);
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (dev->transceiver) {
+		VDBG(dev, "otg_set_power\n");
+		VDBG(dev, "<--- %s()\n", __func__);
+		return otg_set_power(dev->transceiver, mA);
+	}
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return -ENOTSUPP;
+}
+
+
+/* D+ pullup, software-controlled connect/disconnect to USB host */
+static int langwell_pullup(struct usb_gadget *_gadget, int is_on)
+{
+	struct langwell_udc	*dev;
+	u32             	usbcmd;
+	unsigned long   	flags;
+
+	if (!_gadget)
+		return -ENODEV;
+
+	dev = container_of(_gadget, struct langwell_udc, gadget);
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	spin_lock_irqsave(&dev->lock, flags);
+	dev->softconnected = (is_on != 0);
+
+	if (dev->driver && dev->softconnected && dev->vbus_active) {
+		usbcmd = readl(&dev->op_regs->usbcmd);
+		usbcmd |= CMD_RUNSTOP;
+		writel(usbcmd, &dev->op_regs->usbcmd);
+	} else {
+		usbcmd = readl(&dev->op_regs->usbcmd);
+		usbcmd &= ~CMD_RUNSTOP;
+		writel(usbcmd, &dev->op_regs->usbcmd);
+	}
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* device controller usb_gadget_ops structure */
+static const struct usb_gadget_ops langwell_ops = {
+
+	/* returns the current frame number */
+	.get_frame	= langwell_get_frame,
+
+	/* tries to wake up the host connected to this gadget */
+	.wakeup		= langwell_wakeup,
+
+	/* set the device selfpowered feature, always selfpowered */
+	/* .set_selfpowered = langwell_set_selfpowered, */
+
+	/* notify controller that VBUS is powered or not */
+	.vbus_session	= langwell_vbus_session,
+
+	/* constrain controller's VBUS power usage */
+	.vbus_draw	= langwell_vbus_draw,
+
+	/* D+ pullup, software-controlled connect/disconnect to USB host */
+	.pullup		= langwell_pullup,
+};
+
+
+/*-------------------------------------------------------------------------*/
+
+/* device controller operations */
+
+/* reset device controller */
+static int langwell_udc_reset(struct langwell_udc *dev)
+{
+	u32		usbcmd, usbmode, devlc, endpointlistaddr;
+	unsigned long	timeout;
+
+	if (!dev)
+		return -EINVAL;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	/* set controller to stop state */
+	usbcmd = readl(&dev->op_regs->usbcmd);
+	usbcmd &= ~CMD_RUNSTOP;
+	writel(usbcmd, &dev->op_regs->usbcmd);
+
+	/* reset device controller */
+	usbcmd = readl(&dev->op_regs->usbcmd);
+	usbcmd |= CMD_RST;
+	writel(usbcmd, &dev->op_regs->usbcmd);
+
+	/* wait for reset to complete */
+	timeout = jiffies + RESET_TIMEOUT;
+	while (readl(&dev->op_regs->usbcmd) & CMD_RST) {
+		if (time_after(jiffies, timeout)) {
+			ERROR(dev, "device reset timeout\n");
+			return -ETIMEDOUT;
+		}
+		cpu_relax();
+	}
+
+	/* set controller to device mode */
+	usbmode = readl(&dev->op_regs->usbmode);
+	usbmode |= MODE_DEVICE;
+
+	/* turn setup lockout off, require setup tripwire in usbcmd */
+	usbmode |= MODE_SLOM;
+
+	writel(usbmode, &dev->op_regs->usbmode);
+	usbmode = readl(&dev->op_regs->usbmode);
+	VDBG(dev, "usbmode=0x%08x\n", usbmode);
+
+	/* Write-Clear setup status */
+	writel(0, &dev->op_regs->usbsts);
+
+	/* if support USB LPM, ACK all LPM token */
+	if (dev->lpm) {
+		devlc = readl(&dev->op_regs->devlc);
+		devlc &= ~LPM_STL;	/* don't STALL LPM token */
+		devlc &= ~LPM_NYT_ACK;	/* ACK LPM token */
+		writel(devlc, &dev->op_regs->devlc);
+	}
+
+	/* fill endpointlistaddr register */
+	endpointlistaddr = dev->ep_dqh_dma;
+	endpointlistaddr &= ENDPOINTLISTADDR_MASK;
+	writel(endpointlistaddr, &dev->op_regs->endpointlistaddr);
+
+	VDBG(dev, "dQH base (vir: %p, phy: 0x%08x), endpointlistaddr=0x%08x\n",
+			dev->ep_dqh, endpointlistaddr,
+			readl(&dev->op_regs->endpointlistaddr));
+	DBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* reinitialize device controller endpoints */
+static int eps_reinit(struct langwell_udc *dev)
+{
+	struct langwell_ep	*ep;
+	char			name[14];
+	int			i;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* initialize ep0 */
+	ep = &dev->ep[0];
+	ep->dev = dev;
+	strncpy(ep->name, "ep0", sizeof(ep->name));
+	ep->ep.name = ep->name;
+	ep->ep.ops = &langwell_ep_ops;
+	ep->stopped = 0;
+	ep->ep.maxpacket = EP0_MAX_PKT_SIZE;
+	ep->ep_num = 0;
+	ep->desc = &langwell_ep0_desc;
+	INIT_LIST_HEAD(&ep->queue);
+
+	ep->ep_type = USB_ENDPOINT_XFER_CONTROL;
+
+	/* initialize other endpoints */
+	for (i = 2; i < dev->ep_max; i++) {
+		ep = &dev->ep[i];
+		if (i % 2)
+			snprintf(name, sizeof(name), "ep%din", i / 2);
+		else
+			snprintf(name, sizeof(name), "ep%dout", i / 2);
+		ep->dev = dev;
+		strncpy(ep->name, name, sizeof(ep->name));
+		ep->ep.name = ep->name;
+
+		ep->ep.ops = &langwell_ep_ops;
+		ep->stopped = 0;
+		ep->ep.maxpacket = (unsigned short) ~0;
+		ep->ep_num = i / 2;
+
+		INIT_LIST_HEAD(&ep->queue);
+		list_add_tail(&ep->ep.ep_list, &dev->gadget.ep_list);
+
+		ep->dqh = &dev->ep_dqh[i];
+	}
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* enable interrupt and set controller to run state */
+static void langwell_udc_start(struct langwell_udc *dev)
+{
+	u32	usbintr, usbcmd;
+	DBG(dev, "---> %s()\n", __func__);
+
+	/* enable interrupts */
+	usbintr = INTR_ULPIE	/* ULPI */
+		| INTR_SLE	/* suspend */
+		/* | INTR_SRE	SOF received */
+		| INTR_URE	/* USB reset */
+		| INTR_AAE	/* async advance */
+		| INTR_SEE	/* system error */
+		| INTR_FRE	/* frame list rollover */
+		| INTR_PCE	/* port change detect */
+		| INTR_UEE	/* USB error interrupt */
+		| INTR_UE;	/* USB interrupt */
+	writel(usbintr, &dev->op_regs->usbintr);
+
+	/* clear stopped bit */
+	dev->stopped = 0;
+
+	/* set controller to run */
+	usbcmd = readl(&dev->op_regs->usbcmd);
+	usbcmd |= CMD_RUNSTOP;
+	writel(usbcmd, &dev->op_regs->usbcmd);
+
+	DBG(dev, "<--- %s()\n", __func__);
+	return;
+}
+
+
+/* disable interrupt and set controller to stop state */
+static void langwell_udc_stop(struct langwell_udc *dev)
+{
+	u32	usbcmd;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	/* disable all interrupts */
+	writel(0, &dev->op_regs->usbintr);
+
+	/* set stopped bit */
+	dev->stopped = 1;
+
+	/* set controller to stop state */
+	usbcmd = readl(&dev->op_regs->usbcmd);
+	usbcmd &= ~CMD_RUNSTOP;
+	writel(usbcmd, &dev->op_regs->usbcmd);
+
+	DBG(dev, "<--- %s()\n", __func__);
+	return;
+}
+
+
+/* stop all USB activities */
+static void stop_activity(struct langwell_udc *dev,
+		struct usb_gadget_driver *driver)
+{
+	struct langwell_ep	*ep;
+	DBG(dev, "---> %s()\n", __func__);
+
+	nuke(&dev->ep[0], -ESHUTDOWN);
+
+	list_for_each_entry(ep, &dev->gadget.ep_list, ep.ep_list) {
+		nuke(ep, -ESHUTDOWN);
+	}
+
+	/* report disconnect; the driver is already quiesced */
+	if (driver) {
+		spin_unlock(&dev->lock);
+		driver->disconnect(&dev->gadget);
+		spin_lock(&dev->lock);
+	}
+
+	DBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* device "function" sysfs attribute file */
+static ssize_t show_function(struct device *_dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct langwell_udc	*dev = the_controller;
+
+	if (!dev->driver || !dev->driver->function
+			|| strlen(dev->driver->function) > PAGE_SIZE)
+		return 0;
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", dev->driver->function);
+}
+static DEVICE_ATTR(function, S_IRUGO, show_function, NULL);
+
+
+/* device "langwell_udc" sysfs attribute file */
+static ssize_t show_langwell_udc(struct device *_dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct langwell_udc	*dev = the_controller;
+	struct langwell_request *req;
+	struct langwell_ep	*ep = NULL;
+	char			*next;
+	unsigned		size;
+	unsigned		t;
+	unsigned		i;
+	unsigned long		flags;
+	u32			tmp_reg;
+
+	next = buf;
+	size = PAGE_SIZE;
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* driver basic information */
+	t = scnprintf(next, size,
+			DRIVER_DESC "\n"
+			"%s version: %s\n"
+			"Gadget driver: %s\n\n",
+			driver_name, DRIVER_VERSION,
+			dev->driver ? dev->driver->driver.name : "(none)");
+	size -= t;
+	next += t;
+
+	/* device registers */
+	tmp_reg = readl(&dev->op_regs->usbcmd);
+	t = scnprintf(next, size,
+			"USBCMD reg:\n"
+			"SetupTW: %d\n"
+			"Run/Stop: %s\n\n",
+			(tmp_reg & CMD_SUTW) ? 1 : 0,
+			(tmp_reg & CMD_RUNSTOP) ? "Run" : "Stop");
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->usbsts);
+	t = scnprintf(next, size,
+			"USB Status Reg:\n"
+			"Device Suspend: %d\n"
+			"Reset Received: %d\n"
+			"System Error: %s\n"
+			"USB Error Interrupt: %s\n\n",
+			(tmp_reg & STS_SLI) ? 1 : 0,
+			(tmp_reg & STS_URI) ? 1 : 0,
+			(tmp_reg & STS_SEI) ? "Error" : "No error",
+			(tmp_reg & STS_UEI) ? "Error detected" : "No error");
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->usbintr);
+	t = scnprintf(next, size,
+			"USB Intrrupt Enable Reg:\n"
+			"Sleep Enable: %d\n"
+			"SOF Received Enable: %d\n"
+			"Reset Enable: %d\n"
+			"System Error Enable: %d\n"
+			"Port Change Dectected Enable: %d\n"
+			"USB Error Intr Enable: %d\n"
+			"USB Intr Enable: %d\n\n",
+			(tmp_reg & INTR_SLE) ? 1 : 0,
+			(tmp_reg & INTR_SRE) ? 1 : 0,
+			(tmp_reg & INTR_URE) ? 1 : 0,
+			(tmp_reg & INTR_SEE) ? 1 : 0,
+			(tmp_reg & INTR_PCE) ? 1 : 0,
+			(tmp_reg & INTR_UEE) ? 1 : 0,
+			(tmp_reg & INTR_UE) ? 1 : 0);
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->frindex);
+	t = scnprintf(next, size,
+			"USB Frame Index Reg:\n"
+			"Frame Number is 0x%08x\n\n",
+			(tmp_reg & FRINDEX_MASK));
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->deviceaddr);
+	t = scnprintf(next, size,
+			"USB Device Address Reg:\n"
+			"Device Addr is 0x%x\n\n",
+			USBADR(tmp_reg));
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->endpointlistaddr);
+	t = scnprintf(next, size,
+			"USB Endpoint List Address Reg:\n"
+			"Endpoint List Pointer is 0x%x\n\n",
+			EPBASE(tmp_reg));
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->portsc1);
+	t = scnprintf(next, size,
+		"USB Port Status & Control Reg:\n"
+		"Port Reset: %s\n"
+		"Port Suspend Mode: %s\n"
+		"Over-current Change: %s\n"
+		"Port Enable/Disable Change: %s\n"
+		"Port Enabled/Disabled: %s\n"
+		"Current Connect Status: %s\n\n",
+		(tmp_reg & PORTS_PR) ? "Reset" : "Not Reset",
+		(tmp_reg & PORTS_SUSP) ? "Suspend " : "Not Suspend",
+		(tmp_reg & PORTS_OCC) ? "Detected" : "No",
+		(tmp_reg & PORTS_PEC) ? "Changed" : "Not Changed",
+		(tmp_reg & PORTS_PE) ? "Enable" : "Not Correct",
+		(tmp_reg & PORTS_CCS) ?  "Attached" : "Not Attached");
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->devlc);
+	t = scnprintf(next, size,
+		"Device LPM Control Reg:\n"
+		"Parallel Transceiver : %d\n"
+		"Serial Transceiver : %d\n"
+		"Port Speed: %s\n"
+		"Port Force Full Speed Connenct: %s\n"
+		"PHY Low Power Suspend Clock Disable: %s\n"
+		"BmAttributes: %d\n\n",
+		LPM_PTS(tmp_reg),
+		(tmp_reg & LPM_STS) ? 1 : 0,
+		({
+			char	*s;
+			switch (LPM_PSPD(tmp_reg)) {
+			case LPM_SPEED_FULL:
+				s = "Full Speed"; break;
+			case LPM_SPEED_LOW:
+				s = "Low Speed"; break;
+			case LPM_SPEED_HIGH:
+				s = "High Speed"; break;
+			default:
+				s = "Unknown Speed"; break;
+			}
+			s;
+		}),
+		(tmp_reg & LPM_PFSC) ? "Force Full Speed" : "Not Force",
+		(tmp_reg & LPM_PHCD) ? "Disabled" : "Enabled",
+		LPM_BA(tmp_reg));
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->usbmode);
+	t = scnprintf(next, size,
+			"USB Mode Reg:\n"
+			"Controller Mode is : %s\n\n", ({
+				char *s;
+				switch (MODE_CM(tmp_reg)) {
+				case MODE_IDLE:
+					s = "Idle"; break;
+				case MODE_DEVICE:
+					s = "Device Controller"; break;
+				case MODE_HOST:
+					s = "Host Controller"; break;
+				default:
+					s = "None"; break;
+				}
+				s;
+			}));
+	size -= t;
+	next += t;
+
+	tmp_reg = readl(&dev->op_regs->endptsetupstat);
+	t = scnprintf(next, size,
+			"Endpoint Setup Status Reg:\n"
+			"SETUP on ep 0x%04x\n\n",
+			tmp_reg & SETUPSTAT_MASK);
+	size -= t;
+	next += t;
+
+	for (i = 0; i < dev->ep_max / 2; i++) {
+		tmp_reg = readl(&dev->op_regs->endptctrl[i]);
+		t = scnprintf(next, size, "EP Ctrl Reg [%d]: 0x%08x\n",
+				i, tmp_reg);
+		size -= t;
+		next += t;
+	}
+	tmp_reg = readl(&dev->op_regs->endptprime);
+	t = scnprintf(next, size, "EP Prime Reg: 0x%08x\n\n", tmp_reg);
+	size -= t;
+	next += t;
+
+	/* langwell_udc, langwell_ep, langwell_request structure information */
+	ep = &dev->ep[0];
+	t = scnprintf(next, size, "%s MaxPacketSize: 0x%x, ep_num: %d\n",
+			ep->ep.name, ep->ep.maxpacket, ep->ep_num);
+	size -= t;
+	next += t;
+
+	if (list_empty(&ep->queue)) {
+		t = scnprintf(next, size, "its req queue is empty\n\n");
+		size -= t;
+		next += t;
+	} else {
+		list_for_each_entry(req, &ep->queue, queue) {
+			t = scnprintf(next, size,
+				"req %p actual 0x%x length 0x%x  buf %p\n",
+				&req->req, req->req.actual,
+				req->req.length, req->req.buf);
+			size -= t;
+			next += t;
+		}
+	}
+	/* other gadget->eplist ep */
+	list_for_each_entry(ep, &dev->gadget.ep_list, ep.ep_list) {
+		if (ep->desc) {
+			t = scnprintf(next, size,
+					"\n%s MaxPacketSize: 0x%x, "
+					"ep_num: %d\n",
+					ep->ep.name, ep->ep.maxpacket,
+					ep->ep_num);
+			size -= t;
+			next += t;
+
+			if (list_empty(&ep->queue)) {
+				t = scnprintf(next, size,
+						"its req queue is empty\n\n");
+				size -= t;
+				next += t;
+			} else {
+				list_for_each_entry(req, &ep->queue, queue) {
+					t = scnprintf(next, size,
+						"req %p actual 0x%x length "
+						"0x%x  buf %p\n",
+						&req->req, req->req.actual,
+						req->req.length, req->req.buf);
+					size -= t;
+					next += t;
+				}
+			}
+		}
+	}
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+	return PAGE_SIZE - size;
+}
+static DEVICE_ATTR(langwell_udc, S_IRUGO, show_langwell_udc, NULL);
+
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * when a driver is successfully registered, it will receive
+ * control requests including set_configuration(), which enables
+ * non-control requests.  then usb traffic follows until a
+ * disconnect is reported.  then a host may connect again, or
+ * the driver might get unbound.
+ */
+
+int usb_gadget_register_driver(struct usb_gadget_driver *driver)
+{
+	struct langwell_udc	*dev = the_controller;
+	unsigned long		flags;
+	int			retval;
+
+	if (!dev)
+		return -ENODEV;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	if (dev->driver)
+		return -EBUSY;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* hook up the driver ... */
+	driver->driver.bus = NULL;
+	dev->driver = driver;
+	dev->gadget.dev.driver = &driver->driver;
+
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	retval = driver->bind(&dev->gadget);
+	if (retval) {
+		DBG(dev, "bind to driver %s --> %d\n",
+				driver->driver.name, retval);
+		dev->driver = NULL;
+		dev->gadget.dev.driver = NULL;
+		return retval;
+	}
+
+	retval = device_create_file(&dev->pdev->dev, &dev_attr_function);
+	if (retval)
+		goto err_unbind;
+
+	dev->usb_state = USB_STATE_ATTACHED;
+	dev->ep0_state = WAIT_FOR_SETUP;
+	dev->ep0_dir = USB_DIR_OUT;
+
+	/* enable interrupt and set controller to run state */
+	if (dev->got_irq)
+		langwell_udc_start(dev);
+
+	VDBG(dev, "After langwell_udc_start(), print all registers:\n");
+#ifdef	VERBOSE
+	print_all_registers(dev);
+#endif
+
+	INFO(dev, "register driver: %s\n", driver->driver.name);
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+
+err_unbind:
+	driver->unbind(&dev->gadget);
+	dev->gadget.dev.driver = NULL;
+	dev->driver = NULL;
+
+	DBG(dev, "<--- %s()\n", __func__);
+	return retval;
+}
+EXPORT_SYMBOL(usb_gadget_register_driver);
+
+
+/* unregister gadget driver */
+int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
+{
+	struct langwell_udc	*dev = the_controller;
+	unsigned long		flags;
+
+	if (!dev)
+		return -ENODEV;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	if (unlikely(!driver || !driver->bind || !driver->unbind))
+		return -EINVAL;
+
+	/* unbind OTG transceiver */
+	if (dev->transceiver)
+		(void)otg_set_peripheral(dev->transceiver, 0);
+
+	/* disable interrupt and set controller to stop state */
+	langwell_udc_stop(dev);
+
+	dev->usb_state = USB_STATE_ATTACHED;
+	dev->ep0_state = WAIT_FOR_SETUP;
+	dev->ep0_dir = USB_DIR_OUT;
+
+	spin_lock_irqsave(&dev->lock, flags);
+
+	/* stop all usb activities */
+	dev->gadget.speed = USB_SPEED_UNKNOWN;
+	stop_activity(dev, driver);
+	spin_unlock_irqrestore(&dev->lock, flags);
+
+	/* unbind gadget driver */
+	driver->unbind(&dev->gadget);
+	dev->gadget.dev.driver = NULL;
+	dev->driver = NULL;
+
+	device_remove_file(&dev->pdev->dev, &dev_attr_function);
+
+	INFO(dev, "unregistered driver '%s'\n", driver->driver.name);
+	DBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+EXPORT_SYMBOL(usb_gadget_unregister_driver);
+
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * setup tripwire is used as a semaphore to ensure that the setup data
+ * payload is extracted from a dQH without being corrupted
+ */
+static void setup_tripwire(struct langwell_udc *dev)
+{
+	u32			usbcmd,
+				endptsetupstat;
+	unsigned long		timeout;
+	struct langwell_dqh	*dqh;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* ep0 OUT dQH */
+	dqh = &dev->ep_dqh[EP_DIR_OUT];
+
+	/* Write-Clear endptsetupstat */
+	endptsetupstat = readl(&dev->op_regs->endptsetupstat);
+	writel(endptsetupstat, &dev->op_regs->endptsetupstat);
+
+	/* wait until endptsetupstat is cleared */
+	timeout = jiffies + SETUPSTAT_TIMEOUT;
+	while (readl(&dev->op_regs->endptsetupstat)) {
+		if (time_after(jiffies, timeout)) {
+			ERROR(dev, "setup_tripwire timeout\n");
+			break;
+		}
+		cpu_relax();
+	}
+
+	/* while a hazard exists when setup packet arrives */
+	do {
+		/* set setup tripwire bit */
+		usbcmd = readl(&dev->op_regs->usbcmd);
+		writel(usbcmd | CMD_SUTW, &dev->op_regs->usbcmd);
+
+		/* copy the setup packet to local buffer */
+		memcpy(&dev->local_setup_buff, &dqh->dqh_setup, 8);
+	} while (!(readl(&dev->op_regs->usbcmd) & CMD_SUTW));
+
+	/* Write-Clear setup tripwire bit */
+	usbcmd = readl(&dev->op_regs->usbcmd);
+	writel(usbcmd & ~CMD_SUTW, &dev->op_regs->usbcmd);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* protocol ep0 stall, will automatically be cleared on new transaction */
+static void ep0_stall(struct langwell_udc *dev)
+{
+	u32	endptctrl;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* set TX and RX to stall */
+	endptctrl = readl(&dev->op_regs->endptctrl[0]);
+	endptctrl |= EPCTRL_TXS | EPCTRL_RXS;
+	writel(endptctrl, &dev->op_regs->endptctrl[0]);
+
+	/* update ep0 state */
+	dev->ep0_state = WAIT_FOR_SETUP;
+	dev->ep0_dir = USB_DIR_OUT;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* PRIME a status phase for ep0 */
+static int prime_status_phase(struct langwell_udc *dev, int dir)
+{
+	struct langwell_request	*req;
+	struct langwell_ep	*ep;
+	int			status = 0;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (dir == EP_DIR_IN)
+		dev->ep0_dir = USB_DIR_IN;
+	else
+		dev->ep0_dir = USB_DIR_OUT;
+
+	ep = &dev->ep[0];
+	dev->ep0_state = WAIT_FOR_OUT_STATUS;
+
+	req = dev->status_req;
+
+	req->ep = ep;
+	req->req.length = 0;
+	req->req.status = -EINPROGRESS;
+	req->req.actual = 0;
+	req->req.complete = NULL;
+	req->dtd_count = 0;
+
+	if (!req_to_dtd(req))
+		status = queue_dtd(ep, req);
+	else
+		return -ENOMEM;
+
+	if (status)
+		ERROR(dev, "can't queue ep0 status request\n");
+
+	list_add_tail(&req->queue, &ep->queue);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return status;
+}
+
+
+/* SET_ADDRESS request routine */
+static void set_address(struct langwell_udc *dev, u16 value,
+		u16 index, u16 length)
+{
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* save the new address to device struct */
+	dev->dev_addr = (u8) value;
+	VDBG(dev, "dev->dev_addr = %d\n", dev->dev_addr);
+
+	/* update usb state */
+	dev->usb_state = USB_STATE_ADDRESS;
+
+	/* STATUS phase */
+	if (prime_status_phase(dev, EP_DIR_IN))
+		ep0_stall(dev);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* return endpoint by windex */
+static struct langwell_ep *get_ep_by_windex(struct langwell_udc *dev,
+		u16 wIndex)
+{
+	struct langwell_ep		*ep;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if ((wIndex & USB_ENDPOINT_NUMBER_MASK) == 0)
+		return &dev->ep[0];
+
+	list_for_each_entry(ep, &dev->gadget.ep_list, ep.ep_list) {
+		u8	bEndpointAddress;
+		if (!ep->desc)
+			continue;
+
+		bEndpointAddress = ep->desc->bEndpointAddress;
+		if ((wIndex ^ bEndpointAddress) & USB_DIR_IN)
+			continue;
+
+		if ((wIndex & USB_ENDPOINT_NUMBER_MASK)
+			== (bEndpointAddress & USB_ENDPOINT_NUMBER_MASK))
+			return ep;
+	}
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return NULL;
+}
+
+
+/* return whether endpoint is stalled, 0: not stalled; 1: stalled */
+static int ep_is_stall(struct langwell_ep *ep)
+{
+	struct langwell_udc	*dev = ep->dev;
+	u32			endptctrl;
+	int			retval;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	endptctrl = readl(&dev->op_regs->endptctrl[ep->ep_num]);
+	if (is_in(ep))
+		retval = endptctrl & EPCTRL_TXS ? 1 : 0;
+	else
+		retval = endptctrl & EPCTRL_RXS ? 1 : 0;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return retval;
+}
+
+
+/* GET_STATUS request routine */
+static void get_status(struct langwell_udc *dev, u8 request_type, u16 value,
+		u16 index, u16 length)
+{
+	struct langwell_request	*req;
+	struct langwell_ep	*ep;
+	u16	status_data = 0;	/* 16 bits cpu view status data */
+	int	status = 0;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	ep = &dev->ep[0];
+
+	if ((request_type & USB_RECIP_MASK) == USB_RECIP_DEVICE) {
+		/* get device status */
+		status_data = 1 << USB_DEVICE_SELF_POWERED;
+		status_data |= dev->remote_wakeup << USB_DEVICE_REMOTE_WAKEUP;
+	} else if ((request_type & USB_RECIP_MASK) == USB_RECIP_INTERFACE) {
+		/* get interface status */
+		status_data = 0;
+	} else if ((request_type & USB_RECIP_MASK) == USB_RECIP_ENDPOINT) {
+		/* get endpoint status */
+		struct langwell_ep	*epn;
+		epn = get_ep_by_windex(dev, index);
+		/* stall if endpoint doesn't exist */
+		if (!epn)
+			goto stall;
+
+		status_data = ep_is_stall(epn) << USB_ENDPOINT_HALT;
+	}
+
+	dev->ep0_dir = USB_DIR_IN;
+
+	/* borrow the per device status_req */
+	req = dev->status_req;
+
+	/* fill in the reqest structure */
+	*((u16 *) req->req.buf) = cpu_to_le16(status_data);
+	req->ep = ep;
+	req->req.length = 2;
+	req->req.status = -EINPROGRESS;
+	req->req.actual = 0;
+	req->req.complete = NULL;
+	req->dtd_count = 0;
+
+	/* prime the data phase */
+	if (!req_to_dtd(req))
+		status = queue_dtd(ep, req);
+	else			/* no mem */
+		goto stall;
+
+	if (status) {
+		ERROR(dev, "response error on GET_STATUS request\n");
+		goto stall;
+	}
+
+	list_add_tail(&req->queue, &ep->queue);
+	dev->ep0_state = DATA_STATE_XMIT;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return;
+stall:
+	ep0_stall(dev);
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* setup packet interrupt handler */
+static void handle_setup_packet(struct langwell_udc *dev,
+		struct usb_ctrlrequest *setup)
+{
+	u16	wValue = le16_to_cpu(setup->wValue);
+	u16	wIndex = le16_to_cpu(setup->wIndex);
+	u16	wLength = le16_to_cpu(setup->wLength);
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* ep0 fifo flush */
+	nuke(&dev->ep[0], -ESHUTDOWN);
+
+	DBG(dev, "SETUP %02x.%02x v%04x i%04x l%04x\n",
+			setup->bRequestType, setup->bRequest,
+			wValue, wIndex, wLength);
+
+	/* RNDIS gadget delegate */
+	if ((setup->bRequestType == 0x21) && (setup->bRequest == 0x00)) {
+		/* USB_CDC_SEND_ENCAPSULATED_COMMAND */
+		goto delegate;
+	}
+
+	/* USB_CDC_GET_ENCAPSULATED_RESPONSE */
+	if ((setup->bRequestType == 0xa1) && (setup->bRequest == 0x01)) {
+		/* USB_CDC_GET_ENCAPSULATED_RESPONSE */
+		goto delegate;
+	}
+
+	/* We process some stardard setup requests here */
+	switch (setup->bRequest) {
+	case USB_REQ_GET_STATUS:
+		DBG(dev, "SETUP: USB_REQ_GET_STATUS\n");
+		/* get status, DATA and STATUS phase */
+		if ((setup->bRequestType & (USB_DIR_IN | USB_TYPE_MASK))
+					!= (USB_DIR_IN | USB_TYPE_STANDARD))
+			break;
+		get_status(dev, setup->bRequestType, wValue, wIndex, wLength);
+		goto end;
+
+	case USB_REQ_SET_ADDRESS:
+		DBG(dev, "SETUP: USB_REQ_SET_ADDRESS\n");
+		/* STATUS phase */
+		if (setup->bRequestType != (USB_DIR_OUT | USB_TYPE_STANDARD
+						| USB_RECIP_DEVICE))
+			break;
+		set_address(dev, wValue, wIndex, wLength);
+		goto end;
+
+	case USB_REQ_CLEAR_FEATURE:
+	case USB_REQ_SET_FEATURE:
+		/* STATUS phase */
+	{
+		int rc = -EOPNOTSUPP;
+		if (setup->bRequest == USB_REQ_SET_FEATURE)
+			DBG(dev, "SETUP: USB_REQ_SET_FEATURE\n");
+		else if (setup->bRequest == USB_REQ_CLEAR_FEATURE)
+			DBG(dev, "SETUP: USB_REQ_CLEAR_FEATURE\n");
+
+		if ((setup->bRequestType & (USB_RECIP_MASK | USB_TYPE_MASK))
+				== (USB_RECIP_ENDPOINT | USB_TYPE_STANDARD)) {
+			struct langwell_ep	*epn;
+			epn = get_ep_by_windex(dev, wIndex);
+			/* stall if endpoint doesn't exist */
+			if (!epn) {
+				ep0_stall(dev);
+				goto end;
+			}
+
+			if (wValue != 0 || wLength != 0
+					|| epn->ep_num > dev->ep_max)
+				break;
+
+			spin_unlock(&dev->lock);
+			rc = langwell_ep_set_halt(&epn->ep,
+					(setup->bRequest == USB_REQ_SET_FEATURE)
+						? 1 : 0);
+			spin_lock(&dev->lock);
+
+		} else if ((setup->bRequestType & (USB_RECIP_MASK
+				| USB_TYPE_MASK)) == (USB_RECIP_DEVICE
+				| USB_TYPE_STANDARD)) {
+			if (!gadget_is_otg(&dev->gadget))
+				break;
+			else if (setup->bRequest == USB_DEVICE_B_HNP_ENABLE) {
+				dev->gadget.b_hnp_enable = 1;
+#ifdef	OTG_TRANSCEIVER
+				if (!dev->lotg->otg.default_a)
+					dev->lotg->hsm.b_hnp_enable = 1;
+#endif
+			} else if (setup->bRequest == USB_DEVICE_A_HNP_SUPPORT)
+				dev->gadget.a_hnp_support = 1;
+			else if (setup->bRequest ==
+					USB_DEVICE_A_ALT_HNP_SUPPORT)
+				dev->gadget.a_alt_hnp_support = 1;
+			else
+				break;
+			rc = 0;
+		} else
+			break;
+
+		if (rc == 0) {
+			if (prime_status_phase(dev, EP_DIR_IN))
+				ep0_stall(dev);
+		}
+		goto end;
+	}
+
+	case USB_REQ_GET_DESCRIPTOR:
+		DBG(dev, "SETUP: USB_REQ_GET_DESCRIPTOR\n");
+		goto delegate;
+
+	case USB_REQ_SET_DESCRIPTOR:
+		DBG(dev, "SETUP: USB_REQ_SET_DESCRIPTOR unsupported\n");
+		goto delegate;
+
+	case USB_REQ_GET_CONFIGURATION:
+		DBG(dev, "SETUP: USB_REQ_GET_CONFIGURATION\n");
+		goto delegate;
+
+	case USB_REQ_SET_CONFIGURATION:
+		DBG(dev, "SETUP: USB_REQ_SET_CONFIGURATION\n");
+		goto delegate;
+
+	case USB_REQ_GET_INTERFACE:
+		DBG(dev, "SETUP: USB_REQ_GET_INTERFACE\n");
+		goto delegate;
+
+	case USB_REQ_SET_INTERFACE:
+		DBG(dev, "SETUP: USB_REQ_SET_INTERFACE\n");
+		goto delegate;
+
+	case USB_REQ_SYNCH_FRAME:
+		DBG(dev, "SETUP: USB_REQ_SYNCH_FRAME unsupported\n");
+		goto delegate;
+
+	default:
+		/* delegate USB standard requests to the gadget driver */
+		goto delegate;
+delegate:
+		/* USB requests handled by gadget */
+		if (wLength) {
+			/* DATA phase from gadget, STATUS phase from udc */
+			dev->ep0_dir = (setup->bRequestType & USB_DIR_IN)
+					?  USB_DIR_IN : USB_DIR_OUT;
+			VDBG(dev, "dev->ep0_dir = 0x%x, wLength = %d\n",
+					dev->ep0_dir, wLength);
+			spin_unlock(&dev->lock);
+			if (dev->driver->setup(&dev->gadget,
+					&dev->local_setup_buff) < 0)
+				ep0_stall(dev);
+			spin_lock(&dev->lock);
+			dev->ep0_state = (setup->bRequestType & USB_DIR_IN)
+					?  DATA_STATE_XMIT : DATA_STATE_RECV;
+		} else {
+			/* no DATA phase, IN STATUS phase from gadget */
+			dev->ep0_dir = USB_DIR_IN;
+			VDBG(dev, "dev->ep0_dir = 0x%x, wLength = %d\n",
+					dev->ep0_dir, wLength);
+			spin_unlock(&dev->lock);
+			if (dev->driver->setup(&dev->gadget,
+					&dev->local_setup_buff) < 0)
+				ep0_stall(dev);
+			spin_lock(&dev->lock);
+			dev->ep0_state = WAIT_FOR_OUT_STATUS;
+		}
+		break;
+	}
+end:
+	VDBG(dev, "<--- %s()\n", __func__);
+	return;
+}
+
+
+/* transfer completion, process endpoint request and free the completed dTDs
+ * for this request
+ */
+static int process_ep_req(struct langwell_udc *dev, int index,
+		struct langwell_request *curr_req)
+{
+	struct langwell_dtd	*curr_dtd;
+	struct langwell_dqh	*curr_dqh;
+	int			td_complete, actual, remaining_length;
+	int			i, dir;
+	u8			dtd_status = 0;
+	int			retval = 0;
+
+	curr_dqh = &dev->ep_dqh[index];
+	dir = index % 2;
+
+	curr_dtd = curr_req->head;
+	td_complete = 0;
+	actual = curr_req->req.length;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	for (i = 0; i < curr_req->dtd_count; i++) {
+		remaining_length = le16_to_cpu(curr_dtd->dtd_total);
+		actual -= remaining_length;
+
+		/* command execution states by dTD */
+		dtd_status = curr_dtd->dtd_status;
+
+		if (!dtd_status) {
+			/* transfers completed successfully */
+			if (!remaining_length) {
+				td_complete++;
+				VDBG(dev, "dTD transmitted successfully\n");
+			} else {
+				if (dir) {
+					VDBG(dev, "TX dTD remains data\n");
+					retval = -EPROTO;
+					break;
+
+				} else {
+					td_complete++;
+					break;
+				}
+			}
+		} else {
+			/* transfers completed with errors */
+			if (dtd_status & DTD_STS_ACTIVE) {
+				DBG(dev, "request not completed\n");
+				retval = 1;
+				return retval;
+			} else if (dtd_status & DTD_STS_HALTED) {
+				ERROR(dev, "dTD error %08x dQH[%d]\n",
+						dtd_status, index);
+				/* clear the errors and halt condition */
+				curr_dqh->dtd_status = 0;
+				retval = -EPIPE;
+				break;
+			} else if (dtd_status & DTD_STS_DBE) {
+				DBG(dev, "data buffer (overflow) error\n");
+				retval = -EPROTO;
+				break;
+			} else if (dtd_status & DTD_STS_TRE) {
+				DBG(dev, "transaction(ISO) error\n");
+				retval = -EILSEQ;
+				break;
+			} else
+				ERROR(dev, "unknown error (0x%x)!\n",
+						dtd_status);
+		}
+
+		if (i != curr_req->dtd_count - 1)
+			curr_dtd = (struct langwell_dtd *)
+				curr_dtd->next_dtd_virt;
+	}
+
+	if (retval)
+		return retval;
+
+	curr_req->req.actual = actual;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* complete DATA or STATUS phase of ep0 prime status phase if needed */
+static void ep0_req_complete(struct langwell_udc *dev,
+		struct langwell_ep *ep0, struct langwell_request *req)
+{
+	u32	new_addr;
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (dev->usb_state == USB_STATE_ADDRESS) {
+		/* set the new address */
+		new_addr = (u32)dev->dev_addr;
+		writel(new_addr << USBADR_SHIFT, &dev->op_regs->deviceaddr);
+
+		new_addr = USBADR(readl(&dev->op_regs->deviceaddr));
+		VDBG(dev, "new_addr = %d\n", new_addr);
+	}
+
+	done(ep0, req, 0);
+
+	switch (dev->ep0_state) {
+	case DATA_STATE_XMIT:
+		/* receive status phase */
+		if (prime_status_phase(dev, EP_DIR_OUT))
+			ep0_stall(dev);
+		break;
+	case DATA_STATE_RECV:
+		/* send status phase */
+		if (prime_status_phase(dev, EP_DIR_IN))
+			ep0_stall(dev);
+		break;
+	case WAIT_FOR_OUT_STATUS:
+		dev->ep0_state = WAIT_FOR_SETUP;
+		break;
+	case WAIT_FOR_SETUP:
+		ERROR(dev, "unexpect ep0 packets\n");
+		break;
+	default:
+		ep0_stall(dev);
+		break;
+	}
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* USB transfer completion interrupt */
+static void handle_trans_complete(struct langwell_udc *dev)
+{
+	u32			complete_bits;
+	int			i, ep_num, dir, bit_mask, status;
+	struct langwell_ep	*epn;
+	struct langwell_request	*curr_req, *temp_req;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	complete_bits = readl(&dev->op_regs->endptcomplete);
+	VDBG(dev, "endptcomplete register: 0x%08x\n", complete_bits);
+
+	/* Write-Clear the bits in endptcomplete register */
+	writel(complete_bits, &dev->op_regs->endptcomplete);
+
+	if (!complete_bits) {
+		DBG(dev, "complete_bits = 0\n");
+		goto done;
+	}
+
+	for (i = 0; i < dev->ep_max; i++) {
+		ep_num = i / 2;
+		dir = i % 2;
+
+		bit_mask = 1 << (ep_num + 16 * dir);
+
+		if (!(complete_bits & bit_mask))
+			continue;
+
+		/* ep0 */
+		if (i == 1)
+			epn = &dev->ep[0];
+		else
+			epn = &dev->ep[i];
+
+		if (epn->name == NULL) {
+			WARNING(dev, "invalid endpoint\n");
+			continue;
+		}
+
+		if (i < 2)
+			/* ep0 in and out */
+			DBG(dev, "%s-%s transfer completed\n",
+					epn->name,
+					is_in(epn) ? "in" : "out");
+		else
+			DBG(dev, "%s transfer completed\n", epn->name);
+
+		/* process the req queue until an uncomplete request */
+		list_for_each_entry_safe(curr_req, temp_req,
+				&epn->queue, queue) {
+			status = process_ep_req(dev, i, curr_req);
+			VDBG(dev, "%s req status: %d\n", epn->name, status);
+
+			if (status)
+				break;
+
+			/* write back status to req */
+			curr_req->req.status = status;
+
+			/* ep0 request completion */
+			if (ep_num == 0) {
+				ep0_req_complete(dev, epn, curr_req);
+				break;
+			} else {
+				done(epn, curr_req, status);
+			}
+		}
+	}
+done:
+	VDBG(dev, "<--- %s()\n", __func__);
+	return;
+}
+
+
+/* port change detect interrupt handler */
+static void handle_port_change(struct langwell_udc *dev)
+{
+	u32	portsc1, devlc;
+	u32	speed;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (dev->bus_reset)
+		dev->bus_reset = 0;
+
+	portsc1 = readl(&dev->op_regs->portsc1);
+	devlc = readl(&dev->op_regs->devlc);
+	VDBG(dev, "portsc1 = 0x%08x, devlc = 0x%08x\n",
+			portsc1, devlc);
+
+	/* bus reset is finished */
+	if (!(portsc1 & PORTS_PR)) {
+		/* get the speed */
+		speed = LPM_PSPD(devlc);
+		switch (speed) {
+		case LPM_SPEED_HIGH:
+			dev->gadget.speed = USB_SPEED_HIGH;
+			break;
+		case LPM_SPEED_FULL:
+			dev->gadget.speed = USB_SPEED_FULL;
+			break;
+		case LPM_SPEED_LOW:
+			dev->gadget.speed = USB_SPEED_LOW;
+			break;
+		default:
+			dev->gadget.speed = USB_SPEED_UNKNOWN;
+			break;
+		}
+		VDBG(dev, "speed = %d, dev->gadget.speed = %d\n",
+				speed, dev->gadget.speed);
+	}
+
+	/* LPM L0 to L1 */
+	if (dev->lpm && dev->lpm_state == LPM_L0)
+		if (portsc1 & PORTS_SUSP && portsc1 & PORTS_SLP) {
+				INFO(dev, "LPM L0 to L1\n");
+				dev->lpm_state = LPM_L1;
+		}
+
+	/* LPM L1 to L0, force resume or remote wakeup finished */
+	if (dev->lpm && dev->lpm_state == LPM_L1)
+		if (!(portsc1 & PORTS_SUSP)) {
+			if (portsc1 & PORTS_SLP)
+				INFO(dev, "LPM L1 to L0, force resume\n");
+			else
+				INFO(dev, "LPM L1 to L0, remote wakeup\n");
+
+			dev->lpm_state = LPM_L0;
+		}
+
+	/* update USB state */
+	if (!dev->resume_state)
+		dev->usb_state = USB_STATE_DEFAULT;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* USB reset interrupt handler */
+static void handle_usb_reset(struct langwell_udc *dev)
+{
+	u32		deviceaddr,
+			endptsetupstat,
+			endptcomplete;
+	unsigned long	timeout;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	/* Write-Clear the device address */
+	deviceaddr = readl(&dev->op_regs->deviceaddr);
+	writel(deviceaddr & ~USBADR_MASK, &dev->op_regs->deviceaddr);
+
+	dev->dev_addr = 0;
+
+	/* clear usb state */
+	dev->resume_state = 0;
+
+	/* LPM L1 to L0, reset */
+	if (dev->lpm)
+		dev->lpm_state = LPM_L0;
+
+	dev->ep0_dir = USB_DIR_OUT;
+	dev->ep0_state = WAIT_FOR_SETUP;
+	dev->remote_wakeup = 0;		/* default to 0 on reset */
+	dev->gadget.b_hnp_enable = 0;
+	dev->gadget.a_hnp_support = 0;
+	dev->gadget.a_alt_hnp_support = 0;
+
+	/* Write-Clear all the setup token semaphores */
+	endptsetupstat = readl(&dev->op_regs->endptsetupstat);
+	writel(endptsetupstat, &dev->op_regs->endptsetupstat);
+
+	/* Write-Clear all the endpoint complete status bits */
+	endptcomplete = readl(&dev->op_regs->endptcomplete);
+	writel(endptcomplete, &dev->op_regs->endptcomplete);
+
+	/* wait until all endptprime bits cleared */
+	timeout = jiffies + PRIME_TIMEOUT;
+	while (readl(&dev->op_regs->endptprime)) {
+		if (time_after(jiffies, timeout)) {
+			ERROR(dev, "USB reset timeout\n");
+			break;
+		}
+		cpu_relax();
+	}
+
+	/* write 1s to endptflush register to clear any primed buffers */
+	writel((u32) ~0, &dev->op_regs->endptflush);
+
+	if (readl(&dev->op_regs->portsc1) & PORTS_PR) {
+		VDBG(dev, "USB bus reset\n");
+		/* bus is reseting */
+		dev->bus_reset = 1;
+
+		/* reset all the queues, stop all USB activities */
+		stop_activity(dev, dev->driver);
+		dev->usb_state = USB_STATE_DEFAULT;
+	} else {
+		VDBG(dev, "device controller reset\n");
+		/* controller reset */
+		langwell_udc_reset(dev);
+
+		/* reset all the queues, stop all USB activities */
+		stop_activity(dev, dev->driver);
+
+		/* reset ep0 dQH and endptctrl */
+		ep0_reset(dev);
+
+		/* enable interrupt and set controller to run state */
+		langwell_udc_start(dev);
+
+		dev->usb_state = USB_STATE_ATTACHED;
+	}
+
+#ifdef	OTG_TRANSCEIVER
+	/* refer to USB OTG 6.6.2.3 b_hnp_en is cleared */
+	if (!dev->lotg->otg.default_a)
+		dev->lotg->hsm.b_hnp_enable = 0;
+#endif
+
+	VDBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* USB bus suspend/resume interrupt */
+static void handle_bus_suspend(struct langwell_udc *dev)
+{
+	u32		devlc;
+	DBG(dev, "---> %s()\n", __func__);
+
+	dev->resume_state = dev->usb_state;
+	dev->usb_state = USB_STATE_SUSPENDED;
+
+#ifdef	OTG_TRANSCEIVER
+	if (dev->lotg->otg.default_a) {
+		if (dev->lotg->hsm.b_bus_suspend_vld == 1) {
+			dev->lotg->hsm.b_bus_suspend = 1;
+			/* notify transceiver the state changes */
+			if (spin_trylock(&dev->lotg->wq_lock)) {
+				langwell_update_transceiver();
+				spin_unlock(&dev->lotg->wq_lock);
+			}
+		}
+		dev->lotg->hsm.b_bus_suspend_vld++;
+	} else {
+		if (!dev->lotg->hsm.a_bus_suspend) {
+			dev->lotg->hsm.a_bus_suspend = 1;
+			/* notify transceiver the state changes */
+			if (spin_trylock(&dev->lotg->wq_lock)) {
+				langwell_update_transceiver();
+				spin_unlock(&dev->lotg->wq_lock);
+			}
+		}
+	}
+#endif
+
+	/* report suspend to the driver */
+	if (dev->driver) {
+		if (dev->driver->suspend) {
+			spin_unlock(&dev->lock);
+			dev->driver->suspend(&dev->gadget);
+			spin_lock(&dev->lock);
+			DBG(dev, "suspend %s\n", dev->driver->driver.name);
+		}
+	}
+
+	/* enter PHY low power suspend */
+	devlc = readl(&dev->op_regs->devlc);
+	VDBG(dev, "devlc = 0x%08x\n", devlc);
+	devlc |= LPM_PHCD;
+	writel(devlc, &dev->op_regs->devlc);
+
+	DBG(dev, "<--- %s()\n", __func__);
+}
+
+
+static void handle_bus_resume(struct langwell_udc *dev)
+{
+	u32		devlc;
+	DBG(dev, "---> %s()\n", __func__);
+
+	dev->usb_state = dev->resume_state;
+	dev->resume_state = 0;
+
+	/* exit PHY low power suspend */
+	devlc = readl(&dev->op_regs->devlc);
+	VDBG(dev, "devlc = 0x%08x\n", devlc);
+	devlc &= ~LPM_PHCD;
+	writel(devlc, &dev->op_regs->devlc);
+
+#ifdef	OTG_TRANSCEIVER
+	if (dev->lotg->otg.default_a == 0)
+		dev->lotg->hsm.a_bus_suspend = 0;
+#endif
+
+	/* report resume to the driver */
+	if (dev->driver) {
+		if (dev->driver->resume) {
+			spin_unlock(&dev->lock);
+			dev->driver->resume(&dev->gadget);
+			spin_lock(&dev->lock);
+			DBG(dev, "resume %s\n", dev->driver->driver.name);
+		}
+	}
+
+	DBG(dev, "<--- %s()\n", __func__);
+}
+
+
+/* USB device controller interrupt handler */
+static irqreturn_t langwell_irq(int irq, void *_dev)
+{
+	struct langwell_udc	*dev = _dev;
+	u32			usbsts,
+				usbintr,
+				irq_sts,
+				portsc1;
+
+	VDBG(dev, "---> %s()\n", __func__);
+
+	if (dev->stopped) {
+		VDBG(dev, "handle IRQ_NONE\n");
+		VDBG(dev, "<--- %s()\n", __func__);
+		return IRQ_NONE;
+	}
+
+	spin_lock(&dev->lock);
+
+	/* USB status */
+	usbsts = readl(&dev->op_regs->usbsts);
+
+	/* USB interrupt enable */
+	usbintr = readl(&dev->op_regs->usbintr);
+
+	irq_sts = usbsts & usbintr;
+	VDBG(dev, "usbsts = 0x%08x, usbintr = 0x%08x, irq_sts = 0x%08x\n",
+			usbsts, usbintr, irq_sts);
+
+	if (!irq_sts) {
+		VDBG(dev, "handle IRQ_NONE\n");
+		VDBG(dev, "<--- %s()\n", __func__);
+		spin_unlock(&dev->lock);
+		return IRQ_NONE;
+	}
+
+	/* Write-Clear interrupt status bits */
+	writel(irq_sts, &dev->op_regs->usbsts);
+
+	/* resume from suspend */
+	portsc1 = readl(&dev->op_regs->portsc1);
+	if (dev->usb_state == USB_STATE_SUSPENDED)
+		if (!(portsc1 & PORTS_SUSP))
+			handle_bus_resume(dev);
+
+	/* USB interrupt */
+	if (irq_sts & STS_UI) {
+		VDBG(dev, "USB interrupt\n");
+
+		/* setup packet received from ep0 */
+		if (readl(&dev->op_regs->endptsetupstat)
+				& EP0SETUPSTAT_MASK) {
+			VDBG(dev, "USB SETUP packet received interrupt\n");
+			/* setup tripwire semaphone */
+			setup_tripwire(dev);
+			handle_setup_packet(dev, &dev->local_setup_buff);
+		}
+
+		/* USB transfer completion */
+		if (readl(&dev->op_regs->endptcomplete)) {
+			VDBG(dev, "USB transfer completion interrupt\n");
+			handle_trans_complete(dev);
+		}
+	}
+
+	/* SOF received interrupt (for ISO transfer) */
+	if (irq_sts & STS_SRI) {
+		/* FIXME */
+		/* VDBG(dev, "SOF received interrupt\n"); */
+	}
+
+	/* port change detect interrupt */
+	if (irq_sts & STS_PCI) {
+		VDBG(dev, "port change detect interrupt\n");
+		handle_port_change(dev);
+	}
+
+	/* suspend interrrupt */
+	if (irq_sts & STS_SLI) {
+		VDBG(dev, "suspend interrupt\n");
+		handle_bus_suspend(dev);
+	}
+
+	/* USB reset interrupt */
+	if (irq_sts & STS_URI) {
+		VDBG(dev, "USB reset interrupt\n");
+		handle_usb_reset(dev);
+	}
+
+	/* USB error or system error interrupt */
+	if (irq_sts & (STS_UEI | STS_SEI)) {
+		/* FIXME */
+		WARNING(dev, "error IRQ, irq_sts: %x\n", irq_sts);
+	}
+
+	spin_unlock(&dev->lock);
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return IRQ_HANDLED;
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+/* release device structure */
+static void gadget_release(struct device *_dev)
+{
+	struct langwell_udc	*dev = the_controller;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	complete(dev->done);
+
+	DBG(dev, "<--- %s()\n", __func__);
+	kfree(dev);
+}
+
+
+/* tear down the binding between this driver and the pci device */
+static void langwell_udc_remove(struct pci_dev *pdev)
+{
+	struct langwell_udc	*dev = the_controller;
+
+	DECLARE_COMPLETION(done);
+
+	BUG_ON(dev->driver);
+	DBG(dev, "---> %s()\n", __func__);
+
+	dev->done = &done;
+
+	/* free memory allocated in probe */
+	if (dev->dtd_pool)
+		dma_pool_destroy(dev->dtd_pool);
+
+	if (dev->status_req) {
+		kfree(dev->status_req->req.buf);
+		kfree(dev->status_req);
+	}
+
+	if (dev->ep_dqh)
+		dma_free_coherent(&pdev->dev, dev->ep_dqh_size,
+			dev->ep_dqh, dev->ep_dqh_dma);
+
+	kfree(dev->ep);
+
+	/* diable IRQ handler */
+	if (dev->got_irq)
+		free_irq(pdev->irq, dev);
+
+#ifndef	OTG_TRANSCEIVER
+	if (dev->cap_regs)
+		iounmap(dev->cap_regs);
+
+	if (dev->region)
+		release_mem_region(pci_resource_start(pdev, 0),
+				pci_resource_len(pdev, 0));
+
+	if (dev->enabled)
+		pci_disable_device(pdev);
+#else
+	if (dev->transceiver) {
+		otg_put_transceiver(dev->transceiver);
+		dev->transceiver = NULL;
+		dev->lotg = NULL;
+	}
+#endif
+
+	dev->cap_regs = NULL;
+
+	INFO(dev, "unbind\n");
+	DBG(dev, "<--- %s()\n", __func__);
+
+	device_unregister(&dev->gadget.dev);
+	device_remove_file(&pdev->dev, &dev_attr_langwell_udc);
+
+#ifndef	OTG_TRANSCEIVER
+	pci_set_drvdata(pdev, NULL);
+#endif
+
+	/* free dev, wait for the release() finished */
+	wait_for_completion(&done);
+
+	the_controller = NULL;
+}
+
+
+/*
+ * wrap this driver around the specified device, but
+ * don't respond over USB until a gadget driver binds to us.
+ */
+static int langwell_udc_probe(struct pci_dev *pdev,
+		const struct pci_device_id *id)
+{
+	struct langwell_udc	*dev;
+#ifndef	OTG_TRANSCEIVER
+	unsigned long		resource, len;
+#endif
+	void			__iomem *base = NULL;
+	size_t			size;
+	int			retval;
+
+	if (the_controller) {
+		dev_warn(&pdev->dev, "ignoring\n");
+		return -EBUSY;
+	}
+
+	/* alloc, and start init */
+	dev = kzalloc(sizeof *dev, GFP_KERNEL);
+	if (dev == NULL) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	/* initialize device spinlock */
+	spin_lock_init(&dev->lock);
+
+	dev->pdev = pdev;
+	DBG(dev, "---> %s()\n", __func__);
+
+#ifdef	OTG_TRANSCEIVER
+	/* PCI device is already enabled by otg_transceiver driver */
+	dev->enabled = 1;
+
+	/* mem region and register base */
+	dev->region = 1;
+	dev->transceiver = otg_get_transceiver();
+	dev->lotg = otg_to_langwell(dev->transceiver);
+	base = dev->lotg->regs;
+#else
+	pci_set_drvdata(pdev, dev);
+
+	/* now all the pci goodies ... */
+	if (pci_enable_device(pdev) < 0) {
+		retval = -ENODEV;
+		goto error;
+	}
+	dev->enabled = 1;
+
+	/* control register: BAR 0 */
+	resource = pci_resource_start(pdev, 0);
+	len = pci_resource_len(pdev, 0);
+	if (!request_mem_region(resource, len, driver_name)) {
+		ERROR(dev, "controller already in use\n");
+		retval = -EBUSY;
+		goto error;
+	}
+	dev->region = 1;
+
+	base = ioremap_nocache(resource, len);
+#endif
+	if (base == NULL) {
+		ERROR(dev, "can't map memory\n");
+		retval = -EFAULT;
+		goto error;
+	}
+
+	dev->cap_regs = (struct langwell_cap_regs __iomem *) base;
+	VDBG(dev, "dev->cap_regs: %p\n", dev->cap_regs);
+	dev->op_regs = (struct langwell_op_regs __iomem *)
+		(base + OP_REG_OFFSET);
+	VDBG(dev, "dev->op_regs: %p\n", dev->op_regs);
+
+	/* irq setup after old hardware is cleaned up */
+	if (!pdev->irq) {
+		ERROR(dev, "No IRQ. Check PCI setup!\n");
+		retval = -ENODEV;
+		goto error;
+	}
+
+#ifndef	OTG_TRANSCEIVER
+	INFO(dev, "irq %d, io mem: 0x%08lx, len: 0x%08lx, pci mem 0x%p\n",
+			pdev->irq, resource, len, base);
+	/* enables bus-mastering for device dev */
+	pci_set_master(pdev);
+
+	if (request_irq(pdev->irq, langwell_irq, IRQF_SHARED,
+				driver_name, dev) != 0) {
+		ERROR(dev, "request interrupt %d failed\n", pdev->irq);
+		retval = -EBUSY;
+		goto error;
+	}
+	dev->got_irq = 1;
+#endif
+
+	/* set stopped bit */
+	dev->stopped = 1;
+
+	/* capabilities and endpoint number */
+	dev->lpm = (readl(&dev->cap_regs->hccparams) & HCC_LEN) ? 1 : 0;
+	dev->dciversion = readw(&dev->cap_regs->dciversion);
+	dev->devcap = (readl(&dev->cap_regs->dccparams) & DEVCAP) ? 1 : 0;
+	VDBG(dev, "dev->lpm: %d\n", dev->lpm);
+	VDBG(dev, "dev->dciversion: 0x%04x\n", dev->dciversion);
+	VDBG(dev, "dccparams: 0x%08x\n", readl(&dev->cap_regs->dccparams));
+	VDBG(dev, "dev->devcap: %d\n", dev->devcap);
+	if (!dev->devcap) {
+		ERROR(dev, "can't support device mode\n");
+		retval = -ENODEV;
+		goto error;
+	}
+
+	/* a pair of endpoints (out/in) for each address */
+	dev->ep_max = DEN(readl(&dev->cap_regs->dccparams)) * 2;
+	VDBG(dev, "dev->ep_max: %d\n", dev->ep_max);
+
+	/* allocate endpoints memory */
+	dev->ep = kzalloc(sizeof(struct langwell_ep) * dev->ep_max,
+			GFP_KERNEL);
+	if (!dev->ep) {
+		ERROR(dev, "allocate endpoints memory failed\n");
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	/* allocate device dQH memory */
+	size = dev->ep_max * sizeof(struct langwell_dqh);
+	VDBG(dev, "orig size = %d\n", size);
+	if (size < DQH_ALIGNMENT)
+		size = DQH_ALIGNMENT;
+	else if ((size % DQH_ALIGNMENT) != 0) {
+		size += DQH_ALIGNMENT + 1;
+		size &= ~(DQH_ALIGNMENT - 1);
+	}
+	dev->ep_dqh = dma_alloc_coherent(&pdev->dev, size,
+					&dev->ep_dqh_dma, GFP_KERNEL);
+	if (!dev->ep_dqh) {
+		ERROR(dev, "allocate dQH memory failed\n");
+		retval = -ENOMEM;
+		goto error;
+	}
+	dev->ep_dqh_size = size;
+	VDBG(dev, "ep_dqh_size = %d\n", dev->ep_dqh_size);
+
+	/* initialize ep0 status request structure */
+	dev->status_req = kzalloc(sizeof(struct langwell_request), GFP_KERNEL);
+	if (!dev->status_req) {
+		ERROR(dev, "allocate status_req memory failed\n");
+		retval = -ENOMEM;
+		goto error;
+	}
+	INIT_LIST_HEAD(&dev->status_req->queue);
+
+	/* allocate a small amount of memory to get valid address */
+	dev->status_req->req.buf = kmalloc(8, GFP_KERNEL);
+	dev->status_req->req.dma = virt_to_phys(dev->status_req->req.buf);
+
+	dev->resume_state = USB_STATE_NOTATTACHED;
+	dev->usb_state = USB_STATE_POWERED;
+	dev->ep0_dir = USB_DIR_OUT;
+	dev->remote_wakeup = 0;	/* default to 0 on reset */
+
+#ifndef	OTG_TRANSCEIVER
+	/* reset device controller */
+	langwell_udc_reset(dev);
+#endif
+
+	/* initialize gadget structure */
+	dev->gadget.ops = &langwell_ops;	/* usb_gadget_ops */
+	dev->gadget.ep0 = &dev->ep[0].ep;	/* gadget ep0 */
+	INIT_LIST_HEAD(&dev->gadget.ep_list);	/* ep_list */
+	dev->gadget.speed = USB_SPEED_UNKNOWN;	/* speed */
+	dev->gadget.is_dualspeed = 1;		/* support dual speed */
+#ifdef	OTG_TRANSCEIVER
+	dev->gadget.is_otg = 1;			/* support otg mode */
+#endif
+
+	/* the "gadget" abstracts/virtualizes the controller */
+	dev_set_name(&dev->gadget.dev, "gadget");
+	dev->gadget.dev.parent = &pdev->dev;
+	dev->gadget.dev.dma_mask = pdev->dev.dma_mask;
+	dev->gadget.dev.release = gadget_release;
+	dev->gadget.name = driver_name;		/* gadget name */
+
+	/* controller endpoints reinit */
+	eps_reinit(dev);
+
+#ifndef	OTG_TRANSCEIVER
+	/* reset ep0 dQH and endptctrl */
+	ep0_reset(dev);
+#endif
+
+	/* create dTD dma_pool resource */
+	dev->dtd_pool = dma_pool_create("langwell_dtd",
+			&dev->pdev->dev,
+			sizeof(struct langwell_dtd),
+			DTD_ALIGNMENT,
+			DMA_BOUNDARY);
+
+	if (!dev->dtd_pool) {
+		retval = -ENOMEM;
+		goto error;
+	}
+
+	/* done */
+	INFO(dev, "%s\n", driver_desc);
+	INFO(dev, "irq %d, pci mem %p\n", pdev->irq, base);
+	INFO(dev, "Driver version: " DRIVER_VERSION "\n");
+	INFO(dev, "Support (max) %d endpoints\n", dev->ep_max);
+	INFO(dev, "Device interface version: 0x%04x\n", dev->dciversion);
+	INFO(dev, "Controller mode: %s\n", dev->devcap ? "Device" : "Host");
+	INFO(dev, "Support USB LPM: %s\n", dev->lpm ? "Yes" : "No");
+
+	VDBG(dev, "After langwell_udc_probe(), print all registers:\n");
+#ifdef	VERBOSE
+	print_all_registers(dev);
+#endif
+
+	the_controller = dev;
+
+	retval = device_register(&dev->gadget.dev);
+	if (retval)
+		goto error;
+
+	retval = device_create_file(&pdev->dev, &dev_attr_langwell_udc);
+	if (retval)
+		goto error;
+
+	VDBG(dev, "<--- %s()\n", __func__);
+	return 0;
+
+error:
+	if (dev) {
+		DBG(dev, "<--- %s()\n", __func__);
+		langwell_udc_remove(pdev);
+	}
+
+	return retval;
+}
+
+
+/* device controller suspend */
+static int langwell_udc_suspend(struct pci_dev *pdev, pm_message_t state)
+{
+	struct langwell_udc	*dev = the_controller;
+	u32			devlc;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	/* disable interrupt and set controller to stop state */
+	langwell_udc_stop(dev);
+
+	/* diable IRQ handler */
+	if (dev->got_irq)
+		free_irq(pdev->irq, dev);
+	dev->got_irq = 0;
+
+
+	/* save PCI state */
+	pci_save_state(pdev);
+
+	/* set device power state */
+	pci_set_power_state(pdev, PCI_D3hot);
+
+	/* enter PHY low power suspend */
+	devlc = readl(&dev->op_regs->devlc);
+	VDBG(dev, "devlc = 0x%08x\n", devlc);
+	devlc |= LPM_PHCD;
+	writel(devlc, &dev->op_regs->devlc);
+
+	DBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* device controller resume */
+static int langwell_udc_resume(struct pci_dev *pdev)
+{
+	struct langwell_udc	*dev = the_controller;
+	u32			devlc;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	/* exit PHY low power suspend */
+	devlc = readl(&dev->op_regs->devlc);
+	VDBG(dev, "devlc = 0x%08x\n", devlc);
+	devlc &= ~LPM_PHCD;
+	writel(devlc, &dev->op_regs->devlc);
+
+	/* set device D0 power state */
+	pci_set_power_state(pdev, PCI_D0);
+
+	/* restore PCI state */
+	pci_restore_state(pdev);
+
+	/* enable IRQ handler */
+	if (request_irq(pdev->irq, langwell_irq, IRQF_SHARED, driver_name, dev)
+			!= 0) {
+		ERROR(dev, "request interrupt %d failed\n", pdev->irq);
+		return -1;
+	}
+	dev->got_irq = 1;
+
+	/* reset and start controller to run state */
+	if (dev->stopped) {
+		/* reset device controller */
+		langwell_udc_reset(dev);
+
+		/* reset ep0 dQH and endptctrl */
+		ep0_reset(dev);
+
+		/* start device if gadget is loaded */
+		if (dev->driver)
+			langwell_udc_start(dev);
+	}
+
+	/* reset USB status */
+	dev->usb_state = USB_STATE_ATTACHED;
+	dev->ep0_state = WAIT_FOR_SETUP;
+	dev->ep0_dir = USB_DIR_OUT;
+
+	DBG(dev, "<--- %s()\n", __func__);
+	return 0;
+}
+
+
+/* pci driver shutdown */
+static void langwell_udc_shutdown(struct pci_dev *pdev)
+{
+	struct langwell_udc	*dev = the_controller;
+	u32			usbmode;
+
+	DBG(dev, "---> %s()\n", __func__);
+
+	/* reset controller mode to IDLE */
+	usbmode = readl(&dev->op_regs->usbmode);
+	DBG(dev, "usbmode = 0x%08x\n", usbmode);
+	usbmode &= (~3 | MODE_IDLE);
+	writel(usbmode, &dev->op_regs->usbmode);
+
+	DBG(dev, "<--- %s()\n", __func__);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static const struct pci_device_id pci_ids[] = { {
+	.class =	((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
+	.class_mask =	~0,
+	.vendor =	0x8086,
+	.device =	0x0811,
+	.subvendor =	PCI_ANY_ID,
+	.subdevice =	PCI_ANY_ID,
+}, { /* end: all zeroes */ }
+};
+
+
+MODULE_DEVICE_TABLE(pci, pci_ids);
+
+
+static struct pci_driver langwell_pci_driver = {
+	.name =		(char *) driver_name,
+	.id_table =	pci_ids,
+
+	.probe =	langwell_udc_probe,
+	.remove =	langwell_udc_remove,
+
+	/* device controller suspend/resume */
+	.suspend =	langwell_udc_suspend,
+	.resume =	langwell_udc_resume,
+
+	.shutdown =	langwell_udc_shutdown,
+};
+
+
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_AUTHOR("Xiaochen Shen <xiaochen.shen@intel.com>");
+MODULE_VERSION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");
+
+
+static int __init init(void)
+{
+#ifdef	OTG_TRANSCEIVER
+	return langwell_register_peripheral(&langwell_pci_driver);
+#else
+	return pci_register_driver(&langwell_pci_driver);
+#endif
+}
+module_init(init);
+
+
+static void __exit cleanup(void)
+{
+#ifdef	OTG_TRANSCEIVER
+	return langwell_unregister_peripheral(&langwell_pci_driver);
+#else
+	pci_unregister_driver(&langwell_pci_driver);
+#endif
+}
+module_exit(cleanup);
+
diff --git a/drivers/usb/gadget/langwell_udc.h b/drivers/usb/gadget/langwell_udc.h
new file mode 100644
index 000000000000..9719934e1c08
--- /dev/null
+++ b/drivers/usb/gadget/langwell_udc.h
@@ -0,0 +1,228 @@
+/*
+ * Intel Langwell USB Device Controller driver
+ * Copyright (C) 2008-2009, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/usb/langwell_udc.h>
+
+#if defined(CONFIG_USB_LANGWELL_OTG)
+#include <linux/usb/langwell_otg.h>
+#endif
+
+
+/*-------------------------------------------------------------------------*/
+
+/* driver data structures and utilities */
+
+/*
+ * dTD: Device Endpoint Transfer Descriptor
+ * describe to the device controller the location and quantity of
+ * data to be send/received for given transfer
+ */
+struct langwell_dtd {
+	u32	dtd_next;
+/* bits 31:5, next transfer element pointer */
+#define	DTD_NEXT(d)	(((d)>>5)&0x7ffffff)
+#define	DTD_NEXT_MASK	(0x7ffffff << 5)
+/* terminate */
+#define	DTD_TERM	BIT(0)
+	/* bits 7:0, execution back states */
+	u32	dtd_status:8;
+#define	DTD_STATUS(d)	(((d)>>0)&0xff)
+#define	DTD_STS_ACTIVE	BIT(7)	/* active */
+#define	DTD_STS_HALTED	BIT(6)	/* halted */
+#define	DTD_STS_DBE	BIT(5)	/* data buffer error */
+#define	DTD_STS_TRE	BIT(3)	/* transaction error  */
+	/* bits 9:8 */
+	u32	dtd_res0:2;
+	/* bits 11:10, multipier override */
+	u32	dtd_multo:2;
+#define	DTD_MULTO	(BIT(11) | BIT(10))
+	/* bits 14:12 */
+	u32	dtd_res1:3;
+	/* bit 15, interrupt on complete */
+	u32	dtd_ioc:1;
+#define	DTD_IOC		BIT(15)
+	/* bits 30:16, total bytes */
+	u32	dtd_total:15;
+#define	DTD_TOTAL(d)	(((d)>>16)&0x7fff)
+#define	DTD_MAX_TRANSFER_LENGTH	0x4000
+	/* bit 31 */
+	u32	dtd_res2:1;
+	/* dTD buffer pointer page 0 to 4 */
+	u32	dtd_buf[5];
+#define	DTD_OFFSET_MASK	0xfff
+/* bits 31:12, buffer pointer */
+#define	DTD_BUFFER(d)	(((d)>>12)&0x3ff)
+/* bits 11:0, current offset */
+#define	DTD_C_OFFSET(d)	(((d)>>0)&0xfff)
+/* bits 10:0, frame number */
+#define	DTD_FRAME(d)	(((d)>>0)&0x7ff)
+
+	/* driver-private parts */
+
+	/* dtd dma address */
+	dma_addr_t		dtd_dma;
+	/* next dtd virtual address */
+	struct langwell_dtd	*next_dtd_virt;
+};
+
+
+/*
+ * dQH: Device Endpoint Queue Head
+ * describe where all transfers are managed
+ * 48-byte data structure, aligned on 64-byte boundary
+ *
+ * These are associated with dTD structure
+ */
+struct langwell_dqh {
+	/* endpoint capabilities and characteristics */
+	u32	dqh_res0:15;	/* bits 14:0 */
+	u32	dqh_ios:1;	/* bit 15, interrupt on setup */
+#define	DQH_IOS		BIT(15)
+	u32	dqh_mpl:11;	/* bits 26:16, maximum packet length */
+#define	DQH_MPL		(0x7ff << 16)
+	u32	dqh_res1:2;	/* bits 28:27 */
+	u32	dqh_zlt:1;	/* bit 29, zero length termination */
+#define	DQH_ZLT		BIT(29)
+	u32	dqh_mult:2;	/* bits 31:30 */
+#define	DQH_MULT	(BIT(30) | BIT(31))
+
+	/* current dTD pointer */
+	u32	dqh_current;	/* locate the transfer in progress */
+#define DQH_C_DTD(e)	\
+	(((e)>>5)&0x7ffffff)	/* bits 31:5, current dTD pointer */
+
+	/* transfer overlay, hardware parts of a struct langwell_dtd */
+	u32	dtd_next;
+	u32	dtd_status:8;	/* bits 7:0, execution back states */
+	u32	dtd_res0:2;	/* bits 9:8 */
+	u32	dtd_multo:2;	/* bits 11:10, multipier override */
+	u32	dtd_res1:3;	/* bits 14:12 */
+	u32	dtd_ioc:1;	/* bit 15, interrupt on complete */
+	u32	dtd_total:15;	/* bits 30:16, total bytes */
+	u32	dtd_res2:1;	/* bit 31 */
+	u32	dtd_buf[5];	/* dTD buffer pointer page 0 to 4 */
+
+	u32	dqh_res2;
+	struct usb_ctrlrequest	dqh_setup;	/* setup packet buffer */
+} __attribute__ ((aligned(64)));
+
+
+/* endpoint data structure */
+struct langwell_ep {
+	struct usb_ep		ep;
+	dma_addr_t		dma;
+	struct langwell_udc	*dev;
+	unsigned long		irqs;
+	struct list_head	queue;
+	struct langwell_dqh	*dqh;
+	const struct usb_endpoint_descriptor	*desc;
+	char			name[14];
+	unsigned		stopped:1,
+				ep_type:2,
+				ep_num:8;
+};
+
+
+/* request data structure */
+struct langwell_request {
+	struct usb_request	req;
+	struct langwell_dtd	*dtd, *head, *tail;
+	struct langwell_ep	*ep;
+	dma_addr_t		dtd_dma;
+	struct list_head	queue;
+	unsigned		dtd_count;
+	unsigned		mapped:1;
+};
+
+
+/* ep0 transfer state */
+enum ep0_state {
+	WAIT_FOR_SETUP,
+	DATA_STATE_XMIT,
+	DATA_STATE_NEED_ZLP,
+	WAIT_FOR_OUT_STATUS,
+	DATA_STATE_RECV,
+};
+
+
+/* device suspend state */
+enum lpm_state {
+	LPM_L0,	/* on */
+	LPM_L1,	/* LPM L1 sleep */
+	LPM_L2,	/* suspend */
+	LPM_L3,	/* off */
+};
+
+
+/* device data structure */
+struct langwell_udc {
+	/* each pci device provides one gadget, several endpoints */
+	struct usb_gadget	gadget;
+	spinlock_t		lock;	/* device lock */
+	struct langwell_ep	*ep;
+	struct usb_gadget_driver	*driver;
+	struct otg_transceiver	*transceiver;
+	u8			dev_addr;
+	u32			usb_state;
+	u32			resume_state;
+	u32			bus_reset;
+	enum lpm_state		lpm_state;
+	enum ep0_state		ep0_state;
+	u32			ep0_dir;
+	u16			dciversion;
+	unsigned		ep_max;
+	unsigned		devcap:1,
+				enabled:1,
+				region:1,
+				got_irq:1,
+				powered:1,
+				remote_wakeup:1,
+				rate:1,
+				is_reset:1,
+				softconnected:1,
+				vbus_active:1,
+				suspended:1,
+				stopped:1,
+				lpm:1;	/* LPM capability */
+
+	/* pci state used to access those endpoints */
+	struct pci_dev		*pdev;
+
+	/* Langwell otg transceiver */
+	struct langwell_otg	*lotg;
+
+	/* control registers */
+	struct langwell_cap_regs	__iomem	*cap_regs;
+	struct langwell_op_regs		__iomem	*op_regs;
+
+	struct usb_ctrlrequest	local_setup_buff;
+	struct langwell_dqh	*ep_dqh;
+	size_t			ep_dqh_size;
+	dma_addr_t		ep_dqh_dma;
+
+	/* ep0 status request */
+	struct langwell_request	*status_req;
+
+	/* dma pool */
+	struct dma_pool		*dtd_pool;
+
+	/* make sure release() is done */
+	struct completion	*done;
+};
+