/*
 *	driver/usb/gadget/imx_udc.c
 *
 *	Copyright (C) 2005 Mike Lee <eemike@gmail.com>
 *	Copyright (C) 2008 Darius Augulis <augulis.darius@gmail.com>
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This program is distributed in the hope that it will be useful,
 *	but WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *	GNU General Public License for more details.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/slab.h>
#include <linux/prefetch.h>

#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include <mach/usb.h>
#include <mach/hardware.h>

#include "imx_udc.h"

static const char driver_name[] = "imx_udc";
static const char ep0name[] = "ep0";

void ep0_chg_stat(const char *label, struct imx_udc_struct *imx_usb,
							enum ep0_state stat);

/*******************************************************************************
 * IMX UDC hardware related functions
 *******************************************************************************
 */

void imx_udc_enable(struct imx_udc_struct *imx_usb)
{
	int temp = __raw_readl(imx_usb->base + USB_CTRL);
	__raw_writel(temp | CTRL_FE_ENA | CTRL_AFE_ENA,
						imx_usb->base + USB_CTRL);
	imx_usb->gadget.speed = USB_SPEED_FULL;
}

void imx_udc_disable(struct imx_udc_struct *imx_usb)
{
	int temp = __raw_readl(imx_usb->base + USB_CTRL);

	__raw_writel(temp & ~(CTRL_FE_ENA | CTRL_AFE_ENA),
		 imx_usb->base + USB_CTRL);

	ep0_chg_stat(__func__, imx_usb, EP0_IDLE);
	imx_usb->gadget.speed = USB_SPEED_UNKNOWN;
}

void imx_udc_reset(struct imx_udc_struct *imx_usb)
{
	int temp = __raw_readl(imx_usb->base + USB_ENAB);

	/* set RST bit */
	__raw_writel(temp | ENAB_RST, imx_usb->base + USB_ENAB);

	/* wait RST bit to clear */
	do {} while (__raw_readl(imx_usb->base + USB_ENAB) & ENAB_RST);

	/* wait CFG bit to assert */
	do {} while (!(__raw_readl(imx_usb->base + USB_DADR) & DADR_CFG));

	/* udc module is now ready */
}

void imx_udc_config(struct imx_udc_struct *imx_usb)
{
	u8 ep_conf[5];
	u8 i, j, cfg;
	struct imx_ep_struct *imx_ep;

	/* wait CFG bit to assert */
	do {} while (!(__raw_readl(imx_usb->base + USB_DADR) & DADR_CFG));

	/* Download the endpoint buffer for endpoint 0. */
	for (j = 0; j < 5; j++) {
		i = (j == 2 ? imx_usb->imx_ep[0].fifosize : 0x00);
		__raw_writeb(i, imx_usb->base + USB_DDAT);
		do {} while (__raw_readl(imx_usb->base + USB_DADR) & DADR_BSY);
	}

	/* Download the endpoint buffers for endpoints 1-5.
	 * We specify two configurations, one interface
	 */
	for (cfg = 1; cfg < 3; cfg++) {
		for (i = 1; i < IMX_USB_NB_EP; i++) {
			imx_ep = &imx_usb->imx_ep[i];
			/* EP no | Config no */
			ep_conf[0] = (i << 4) | (cfg << 2);
			/* Type | Direction */
			ep_conf[1] = (imx_ep->bmAttributes << 3) |
					(EP_DIR(imx_ep) << 2);
			/* Max packet size */
			ep_conf[2] = imx_ep->fifosize;
			/* TRXTYP */
			ep_conf[3] = 0xC0;
			/* FIFO no */
			ep_conf[4] = i;

			D_INI(imx_usb->dev,
				"<%s> ep%d_conf[%d]:"
				"[%02x-%02x-%02x-%02x-%02x]\n",
				__func__, i, cfg,
				ep_conf[0], ep_conf[1], ep_conf[2],
				ep_conf[3], ep_conf[4]);

			for (j = 0; j < 5; j++) {
				__raw_writeb(ep_conf[j],
					imx_usb->base + USB_DDAT);
				do {} while (__raw_readl(imx_usb->base
								+ USB_DADR)
					& DADR_BSY);
			}
		}
	}

	/* wait CFG bit to clear */
	do {} while (__raw_readl(imx_usb->base + USB_DADR) & DADR_CFG);
}

void imx_udc_init_irq(struct imx_udc_struct *imx_usb)
{
	int i;

	/* Mask and clear all irqs */
	__raw_writel(0xFFFFFFFF, imx_usb->base + USB_MASK);
	__raw_writel(0xFFFFFFFF, imx_usb->base + USB_INTR);
	for (i = 0; i < IMX_USB_NB_EP; i++) {
		__raw_writel(0x1FF, imx_usb->base + USB_EP_MASK(i));
		__raw_writel(0x1FF, imx_usb->base + USB_EP_INTR(i));
	}

	/* Enable USB irqs */
	__raw_writel(INTR_MSOF | INTR_FRAME_MATCH, imx_usb->base + USB_MASK);

	/* Enable EP0 irqs */
	__raw_writel(0x1FF & ~(EPINTR_DEVREQ | EPINTR_MDEVREQ | EPINTR_EOT
		| EPINTR_EOF | EPINTR_FIFO_EMPTY | EPINTR_FIFO_FULL),
		imx_usb->base + USB_EP_MASK(0));
}

void imx_udc_init_ep(struct imx_udc_struct *imx_usb)
{
	int i, max, temp;
	struct imx_ep_struct *imx_ep;
	for (i = 0; i < IMX_USB_NB_EP; i++) {
		imx_ep = &imx_usb->imx_ep[i];
		switch (imx_ep->fifosize) {
		case 8:
			max = 0;
			break;
		case 16:
			max = 1;
			break;
		case 32:
			max = 2;
			break;
		case 64:
			max = 3;
			break;
		default:
			max = 1;
			break;
		}
		temp = (EP_DIR(imx_ep) << 7) | (max << 5)
			| (imx_ep->bmAttributes << 3);
		__raw_writel(temp, imx_usb->base + USB_EP_STAT(i));
		__raw_writel(temp | EPSTAT_FLUSH,
						imx_usb->base + USB_EP_STAT(i));
		D_INI(imx_usb->dev, "<%s> ep%d_stat %08x\n", __func__, i,
			__raw_readl(imx_usb->base + USB_EP_STAT(i)));
	}
}

void imx_udc_init_fifo(struct imx_udc_struct *imx_usb)
{
	int i, temp;
	struct imx_ep_struct *imx_ep;
	for (i = 0; i < IMX_USB_NB_EP; i++) {
		imx_ep = &imx_usb->imx_ep[i];

		/* Fifo control */
		temp = EP_DIR(imx_ep) ? 0x0B000000 : 0x0F000000;
		__raw_writel(temp, imx_usb->base + USB_EP_FCTRL(i));
		D_INI(imx_usb->dev, "<%s> ep%d_fctrl %08x\n", __func__, i,
			__raw_readl(imx_usb->base + USB_EP_FCTRL(i)));

		/* Fifo alarm */
		temp = (i ? imx_ep->fifosize / 2 : 0);
		__raw_writel(temp, imx_usb->base + USB_EP_FALRM(i));
		D_INI(imx_usb->dev, "<%s> ep%d_falrm %08x\n", __func__, i,
			__raw_readl(imx_usb->base + USB_EP_FALRM(i)));
	}
}

static void imx_udc_init(struct imx_udc_struct *imx_usb)
{
	/* Reset UDC */
	imx_udc_reset(imx_usb);

	/* Download config to enpoint buffer */
	imx_udc_config(imx_usb);

	/* Setup interrups */
	imx_udc_init_irq(imx_usb);

	/* Setup endpoints */
	imx_udc_init_ep(imx_usb);

	/* Setup fifos */
	imx_udc_init_fifo(imx_usb);
}

void imx_ep_irq_enable(struct imx_ep_struct *imx_ep)
{

	int i = EP_NO(imx_ep);

	__raw_writel(0x1FF, imx_ep->imx_usb->base + USB_EP_MASK(i));
	__raw_writel(0x1FF, imx_ep->imx_usb->base + USB_EP_INTR(i));
	__raw_writel(0x1FF & ~(EPINTR_EOT | EPINTR_EOF),
		imx_ep->imx_usb->base + USB_EP_MASK(i));
}

void imx_ep_irq_disable(struct imx_ep_struct *imx_ep)
{

	int i = EP_NO(imx_ep);

	__raw_writel(0x1FF, imx_ep->imx_usb->base + USB_EP_MASK(i));
	__raw_writel(0x1FF, imx_ep->imx_usb->base + USB_EP_INTR(i));
}

int imx_ep_empty(struct imx_ep_struct *imx_ep)
{
	struct imx_udc_struct *imx_usb = imx_ep->imx_usb;

	return __raw_readl(imx_usb->base + USB_EP_FSTAT(EP_NO(imx_ep)))
			& FSTAT_EMPTY;
}

unsigned imx_fifo_bcount(struct imx_ep_struct *imx_ep)
{
	struct imx_udc_struct *imx_usb = imx_ep->imx_usb;

	return (__raw_readl(imx_usb->base + USB_EP_STAT(EP_NO(imx_ep)))
			& EPSTAT_BCOUNT) >> 16;
}

void imx_flush(struct imx_ep_struct *imx_ep)
{
	struct imx_udc_struct *imx_usb = imx_ep->imx_usb;

	int temp = __raw_readl(imx_usb->base + USB_EP_STAT(EP_NO(imx_ep)));
	__raw_writel(temp | EPSTAT_FLUSH,
		imx_usb->base + USB_EP_STAT(EP_NO(imx_ep)));
}

void imx_ep_stall(struct imx_ep_struct *imx_ep)
{
	struct imx_udc_struct *imx_usb = imx_ep->imx_usb;
	int temp, i;

	D_ERR(imx_usb->dev,
		"<%s> Forced stall on %s\n", __func__, imx_ep->ep.name);

	imx_flush(imx_ep);

	/* Special care for ep0 */
	if (!EP_NO(imx_ep)) {
		temp = __raw_readl(imx_usb->base + USB_CTRL);
		__raw_writel(temp | CTRL_CMDOVER | CTRL_CMDERROR,
						imx_usb->base + USB_CTRL);
		do { } while (__raw_readl(imx_usb->base + USB_CTRL)
						& CTRL_CMDOVER);
		temp = __raw_readl(imx_usb->base + USB_CTRL);
		__raw_writel(temp & ~CTRL_CMDERROR, imx_usb->base + USB_CTRL);
	}
	else {
		temp = __raw_readl(imx_usb->base + USB_EP_STAT(EP_NO(imx_ep)));
		__raw_writel(temp | EPSTAT_STALL,
			imx_usb->base + USB_EP_STAT(EP_NO(imx_ep)));

		for (i = 0; i < 100; i ++) {
			temp = __raw_readl(imx_usb->base
						+ USB_EP_STAT(EP_NO(imx_ep)));
			if (!(temp & EPSTAT_STALL))
	 			break;
	 		udelay(20);
	 	}
		if (i == 100)
			D_ERR(imx_usb->dev, "<%s> Non finished stall on %s\n",
				__func__, imx_ep->ep.name);
	}
}

static int imx_udc_get_frame(struct usb_gadget *_gadget)
{
	struct imx_udc_struct *imx_usb = container_of(_gadget,
			struct imx_udc_struct, gadget);

	return __raw_readl(imx_usb->base + USB_FRAME) & 0x7FF;
}

static int imx_udc_wakeup(struct usb_gadget *_gadget)
{
	return 0;
}

/*******************************************************************************
 * USB request control functions
 *******************************************************************************
 */

static void ep_add_request(struct imx_ep_struct *imx_ep,
							struct imx_request *req)
{
	if (unlikely(!req))
		return;

	req->in_use = 1;
	list_add_tail(&req->queue, &imx_ep->queue);
}

static void ep_del_request(struct imx_ep_struct *imx_ep,
							struct imx_request *req)
{
	if (unlikely(!req))
		return;

	list_del_init(&req->queue);
	req->in_use = 0;
}

static void done(struct imx_ep_struct *imx_ep,
					struct imx_request *req, int status)
{
	ep_del_request(imx_ep, req);

	if (likely(req->req.status == -EINPROGRESS))
		req->req.status = status;
	else
		status = req->req.status;

	if (status && status != -ESHUTDOWN)
		D_ERR(imx_ep->imx_usb->dev,
			"<%s> complete %s req %p stat %d len %u/%u\n", __func__,
			imx_ep->ep.name, &req->req, status,
			req->req.actual, req->req.length);

	req->req.complete(&imx_ep->ep, &req->req);
}

static void nuke(struct imx_ep_struct *imx_ep, int status)
{
	struct imx_request *req;

	while (!list_empty(&imx_ep->queue)) {
		req = list_entry(imx_ep->queue.next, struct imx_request, queue);
		done(imx_ep, req, status);
	}
}

/*******************************************************************************
 * Data tansfer over USB functions
 *******************************************************************************
 */
static int read_packet(struct imx_ep_struct *imx_ep, struct imx_request *req)
{
	u8	*buf;
	int	bytes_ep, bufferspace, count, i;

	bytes_ep = imx_fifo_bcount(imx_ep);
	bufferspace = req->req.length - req->req.actual;

	buf = req->req.buf + req->req.actual;
	prefetchw(buf);

	if (unlikely(imx_ep_empty(imx_ep)))
		count = 0;	/* zlp */
	else
		count = min(bytes_ep, bufferspace);

	for (i = count; i > 0; i--)
		*buf++ = __raw_readb(imx_ep->imx_usb->base
						+ USB_EP_FDAT0(EP_NO(imx_ep)));
	req->req.actual += count;

	return count;
}

static int write_packet(struct imx_ep_struct *imx_ep, struct imx_request *req)
{
	u8	*buf;
	int	length, count, temp;

	if (unlikely(__raw_readl(imx_ep->imx_usb->base +
				 USB_EP_STAT(EP_NO(imx_ep))) & EPSTAT_ZLPS)) {
		D_TRX(imx_ep->imx_usb->dev, "<%s> zlp still queued in EP %s\n",
			__func__, imx_ep->ep.name);
		return -1;
	}

	buf = req->req.buf + req->req.actual;
	prefetch(buf);

	length = min(req->req.length - req->req.actual, (u32)imx_ep->fifosize);

	if (imx_fifo_bcount(imx_ep) + length > imx_ep->fifosize) {
		D_TRX(imx_ep->imx_usb->dev, "<%s> packet overfill %s fifo\n",
			__func__, imx_ep->ep.name);
		return -1;
	}

	req->req.actual += length;
	count = length;

	if (!count && req->req.zero) {	/* zlp */
		temp = __raw_readl(imx_ep->imx_usb->base
			+ USB_EP_STAT(EP_NO(imx_ep)));
		__raw_writel(temp | EPSTAT_ZLPS, imx_ep->imx_usb->base
			+ USB_EP_STAT(EP_NO(imx_ep)));
		D_TRX(imx_ep->imx_usb->dev, "<%s> zero packet\n", __func__);
		return 0;
	}

	while (count--) {
		if (count == 0) {	/* last byte */
			temp = __raw_readl(imx_ep->imx_usb->base
				+ USB_EP_FCTRL(EP_NO(imx_ep)));
			__raw_writel(temp | FCTRL_WFR, imx_ep->imx_usb->base
				+ USB_EP_FCTRL(EP_NO(imx_ep)));
		}
		__raw_writeb(*buf++,
			imx_ep->imx_usb->base + USB_EP_FDAT0(EP_NO(imx_ep)));
	}

	return length;
}

static int read_fifo(struct imx_ep_struct *imx_ep, struct imx_request *req)
{
	int 	bytes = 0,
		count,
		completed = 0;

	while (__raw_readl(imx_ep->imx_usb->base + USB_EP_FSTAT(EP_NO(imx_ep)))
		& FSTAT_FR) {
			count = read_packet(imx_ep, req);
			bytes += count;

			completed = (count != imx_ep->fifosize);
			if (completed || req->req.actual == req->req.length) {
				completed = 1;
				break;
			}
	}

	if (completed || !req->req.length) {
		done(imx_ep, req, 0);
		D_REQ(imx_ep->imx_usb->dev, "<%s> %s req<%p> %s\n",
			__func__, imx_ep->ep.name, req,
			completed ? "completed" : "not completed");
		if (!EP_NO(imx_ep))
			ep0_chg_stat(__func__, imx_ep->imx_usb, EP0_IDLE);
	}

	D_TRX(imx_ep->imx_usb->dev, "<%s> bytes read: %d\n", __func__, bytes);

	return completed;
}

static int write_fifo(struct imx_ep_struct *imx_ep, struct imx_request *req)
{
	int	bytes = 0,
		count,
		completed = 0;

	while (!completed) {
		count = write_packet(imx_ep, req);
		if (count < 0)
			break; /* busy */
		bytes += count;

		/* last packet "must be" short (or a zlp) */
		completed = (count != imx_ep->fifosize);

		if (unlikely(completed)) {
			done(imx_ep, req, 0);
			D_REQ(imx_ep->imx_usb->dev, "<%s> %s req<%p> %s\n",
				__func__, imx_ep->ep.name, req,
				completed ? "completed" : "not completed");
			if (!EP_NO(imx_ep))
				ep0_chg_stat(__func__,
						imx_ep->imx_usb, EP0_IDLE);
		}
	}

	D_TRX(imx_ep->imx_usb->dev, "<%s> bytes sent: %d\n", __func__, bytes);

	return completed;
}

/*******************************************************************************
 * Endpoint handlers
 *******************************************************************************
 */
static int handle_ep(struct imx_ep_struct *imx_ep)
{
	struct imx_request *req;
	int completed = 0;

	do {
		if (!list_empty(&imx_ep->queue))
			req = list_entry(imx_ep->queue.next,
				struct imx_request, queue);
		else {
			D_REQ(imx_ep->imx_usb->dev, "<%s> no request on %s\n",
				__func__, imx_ep->ep.name);
			return 0;
		}

		if (EP_DIR(imx_ep))	/* to host */
			completed = write_fifo(imx_ep, req);
		else			/* to device */
			completed = read_fifo(imx_ep, req);

		dump_ep_stat(__func__, imx_ep);

	} while (completed);

	return 0;
}

static int handle_ep0(struct imx_ep_struct *imx_ep)
{
	struct imx_request *req = NULL;
	int ret = 0;

	if (!list_empty(&imx_ep->queue)) {
		req = list_entry(imx_ep->queue.next, struct imx_request, queue);

		switch (imx_ep->imx_usb->ep0state) {

		case EP0_IN_DATA_PHASE:			/* GET_DESCRIPTOR */
			write_fifo(imx_ep, req);
			break;
		case EP0_OUT_DATA_PHASE:		/* SET_DESCRIPTOR */
			read_fifo(imx_ep, req);
			break;
		default:
			D_EP0(imx_ep->imx_usb->dev,
				"<%s> ep0 i/o, odd state %d\n",
				__func__, imx_ep->imx_usb->ep0state);
			ep_del_request(imx_ep, req);
			ret = -EL2HLT;
			break;
		}
	}

	else
		D_ERR(imx_ep->imx_usb->dev, "<%s> no request on %s\n",
						__func__, imx_ep->ep.name);

	return ret;
}

static void handle_ep0_devreq(struct imx_udc_struct *imx_usb)
{
	struct imx_ep_struct *imx_ep = &imx_usb->imx_ep[0];
	union {
		struct usb_ctrlrequest	r;
		u8			raw[8];
		u32			word[2];
	} u;
	int temp, i;

	nuke(imx_ep, -EPROTO);

	/* read SETUP packet */
	for (i = 0; i < 2; i++) {
		if (imx_ep_empty(imx_ep)) {
			D_ERR(imx_usb->dev,
				"<%s> no setup packet received\n", __func__);
			goto stall;
		}
		u.word[i] = __raw_readl(imx_usb->base
						+ USB_EP_FDAT(EP_NO(imx_ep)));
	}

	temp = imx_ep_empty(imx_ep);
	while (!imx_ep_empty(imx_ep)) {
		i = __raw_readl(imx_usb->base +	USB_EP_FDAT(EP_NO(imx_ep)));
		D_ERR(imx_usb->dev,
			"<%s> wrong to have extra bytes for setup : 0x%08x\n",
			__func__, i);
	}
	if (!temp)
		goto stall;

	le16_to_cpus(&u.r.wValue);
	le16_to_cpus(&u.r.wIndex);
	le16_to_cpus(&u.r.wLength);

	D_REQ(imx_usb->dev, "<%s> SETUP %02x.%02x v%04x i%04x l%04x\n",
		__func__, u.r.bRequestType, u.r.bRequest,
		u.r.wValue, u.r.wIndex, u.r.wLength);

	if (imx_usb->set_config) {
		/* NACK the host by using CMDOVER */
		temp = __raw_readl(imx_usb->base + USB_CTRL);
		__raw_writel(temp | CTRL_CMDOVER, imx_usb->base + USB_CTRL);

		D_ERR(imx_usb->dev,
			"<%s> set config req is pending, NACK the host\n",
			__func__);
		return;
	}

	if (u.r.bRequestType & USB_DIR_IN)
		ep0_chg_stat(__func__, imx_usb, EP0_IN_DATA_PHASE);
	else
		ep0_chg_stat(__func__, imx_usb, EP0_OUT_DATA_PHASE);

	i = imx_usb->driver->setup(&imx_usb->gadget, &u.r);
	if (i < 0) {
		D_ERR(imx_usb->dev, "<%s> device setup error %d\n",
			__func__, i);
		goto stall;
	}

	return;
stall:
	D_ERR(imx_usb->dev, "<%s> protocol STALL\n", __func__);
	imx_ep_stall(imx_ep);
	ep0_chg_stat(__func__, imx_usb, EP0_STALL);
	return;
}

/*******************************************************************************
 * USB gadget callback functions
 *******************************************************************************
 */

static int imx_ep_enable(struct usb_ep *usb_ep,
				const struct usb_endpoint_descriptor *desc)
{
	struct imx_ep_struct *imx_ep = container_of(usb_ep,
						struct imx_ep_struct, ep);
	struct imx_udc_struct *imx_usb = imx_ep->imx_usb;
	unsigned long flags;

	if (!usb_ep
		|| !desc
		|| !EP_NO(imx_ep)
		|| desc->bDescriptorType != USB_DT_ENDPOINT
		|| imx_ep->bEndpointAddress != desc->bEndpointAddress) {
			D_ERR(imx_usb->dev,
				"<%s> bad ep or descriptor\n", __func__);
			return -EINVAL;
	}

	if (imx_ep->bmAttributes != desc->bmAttributes) {
		D_ERR(imx_usb->dev,
			"<%s> %s type mismatch\n", __func__, usb_ep->name);
		return -EINVAL;
	}

	if (imx_ep->fifosize < usb_endpoint_maxp(desc)) {
		D_ERR(imx_usb->dev,
			"<%s> bad %s maxpacket\n", __func__, usb_ep->name);
		return -ERANGE;
	}

	if (!imx_usb->driver || imx_usb->gadget.speed == USB_SPEED_UNKNOWN) {
		D_ERR(imx_usb->dev, "<%s> bogus device state\n", __func__);
		return -ESHUTDOWN;
	}

	local_irq_save(flags);

	imx_ep->stopped = 0;
	imx_flush(imx_ep);
	imx_ep_irq_enable(imx_ep);

	local_irq_restore(flags);

	D_EPX(imx_usb->dev, "<%s> ENABLED %s\n", __func__, usb_ep->name);
	return 0;
}

static int imx_ep_disable(struct usb_ep *usb_ep)
{
	struct imx_ep_struct *imx_ep = container_of(usb_ep,
						struct imx_ep_struct, ep);
	unsigned long flags;

	if (!usb_ep || !EP_NO(imx_ep) || !list_empty(&imx_ep->queue)) {
		D_ERR(imx_ep->imx_usb->dev, "<%s> %s can not be disabled\n",
			__func__, usb_ep ? imx_ep->ep.name : NULL);
		return -EINVAL;
	}

	local_irq_save(flags);

	imx_ep->stopped = 1;
	nuke(imx_ep, -ESHUTDOWN);
	imx_flush(imx_ep);
	imx_ep_irq_disable(imx_ep);

	local_irq_restore(flags);

	D_EPX(imx_ep->imx_usb->dev,
		"<%s> DISABLED %s\n", __func__, usb_ep->name);
	return 0;
}

static struct usb_request *imx_ep_alloc_request
					(struct usb_ep *usb_ep, gfp_t gfp_flags)
{
	struct imx_request *req;

	if (!usb_ep)
		return NULL;

	req = kzalloc(sizeof *req, gfp_flags);
	if (!req)
		return NULL;

	INIT_LIST_HEAD(&req->queue);
	req->in_use = 0;

	return &req->req;
}

static void imx_ep_free_request
			(struct usb_ep *usb_ep, struct usb_request *usb_req)
{
	struct imx_request *req;

	req = container_of(usb_req, struct imx_request, req);
	WARN_ON(!list_empty(&req->queue));
	kfree(req);
}

static int imx_ep_queue
	(struct usb_ep *usb_ep, struct usb_request *usb_req, gfp_t gfp_flags)
{
	struct imx_ep_struct	*imx_ep;
	struct imx_udc_struct	*imx_usb;
	struct imx_request	*req;
	unsigned long		flags;
	int			ret = 0;

	imx_ep = container_of(usb_ep, struct imx_ep_struct, ep);
	imx_usb = imx_ep->imx_usb;
	req = container_of(usb_req, struct imx_request, req);

	/*
	  Special care on IMX udc.
	  Ignore enqueue when after set configuration from the
	  host. This assume all gadget drivers reply set
	  configuration with the next ep0 req enqueue.
	*/
	if (imx_usb->set_config && !EP_NO(imx_ep)) {
		imx_usb->set_config = 0;
		D_ERR(imx_usb->dev,
			"<%s> gadget reply set config\n", __func__);
		return 0;
	}

	if (unlikely(!usb_req || !req || !usb_req->complete || !usb_req->buf)) {
		D_ERR(imx_usb->dev, "<%s> bad params\n", __func__);
		return -EINVAL;
	}

	if (unlikely(!usb_ep || !imx_ep)) {
		D_ERR(imx_usb->dev, "<%s> bad ep\n", __func__);
		return -EINVAL;
	}

	if (!imx_usb->driver || imx_usb->gadget.speed == USB_SPEED_UNKNOWN) {
		D_ERR(imx_usb->dev, "<%s> bogus device state\n", __func__);
		return -ESHUTDOWN;
	}

	/* Debug */
	D_REQ(imx_usb->dev, "<%s> ep%d %s request for [%d] bytes\n",
		__func__, EP_NO(imx_ep),
		((!EP_NO(imx_ep) && imx_ep->imx_usb->ep0state
							== EP0_IN_DATA_PHASE)
		|| (EP_NO(imx_ep) && EP_DIR(imx_ep)))
					? "IN" : "OUT", usb_req->length);
	dump_req(__func__, imx_ep, usb_req);

	if (imx_ep->stopped) {
		usb_req->status = -ESHUTDOWN;
		return -ESHUTDOWN;
	}

	if (req->in_use) {
		D_ERR(imx_usb->dev,
			"<%s> refusing to queue req %p (already queued)\n",
			__func__, req);
		return 0;
	}

	local_irq_save(flags);

	usb_req->status = -EINPROGRESS;
	usb_req->actual = 0;

	ep_add_request(imx_ep, req);

	if (!EP_NO(imx_ep))
		ret = handle_ep0(imx_ep);
	else
		ret = handle_ep(imx_ep);

	local_irq_restore(flags);
	return ret;
}

static int imx_ep_dequeue(struct usb_ep *usb_ep, struct usb_request *usb_req)
{

	struct imx_ep_struct *imx_ep = container_of
					(usb_ep, struct imx_ep_struct, ep);
	struct imx_request *req;
	unsigned long flags;

	if (unlikely(!usb_ep || !EP_NO(imx_ep))) {
		D_ERR(imx_ep->imx_usb->dev, "<%s> bad ep\n", __func__);
		return -EINVAL;
	}

	local_irq_save(flags);

	/* make sure it's actually queued on this endpoint */
	list_for_each_entry(req, &imx_ep->queue, queue) {
		if (&req->req == usb_req)
			break;
	}
	if (&req->req != usb_req) {
		local_irq_restore(flags);
		return -EINVAL;
	}

	done(imx_ep, req, -ECONNRESET);

	local_irq_restore(flags);
	return 0;
}

static int imx_ep_set_halt(struct usb_ep *usb_ep, int value)
{
	struct imx_ep_struct *imx_ep = container_of
					(usb_ep, struct imx_ep_struct, ep);
	unsigned long flags;

	if (unlikely(!usb_ep || !EP_NO(imx_ep))) {
		D_ERR(imx_ep->imx_usb->dev, "<%s> bad ep\n", __func__);
		return -EINVAL;
	}

	local_irq_save(flags);

	if ((imx_ep->bEndpointAddress & USB_DIR_IN)
		&& !list_empty(&imx_ep->queue)) {
			local_irq_restore(flags);
			return -EAGAIN;
	}

	imx_ep_stall(imx_ep);

	local_irq_restore(flags);

	D_EPX(imx_ep->imx_usb->dev, "<%s> %s halt\n", __func__, usb_ep->name);
	return 0;
}

static int imx_ep_fifo_status(struct usb_ep *usb_ep)
{
	struct imx_ep_struct *imx_ep = container_of
					(usb_ep, struct imx_ep_struct, ep);

	if (!usb_ep) {
		D_ERR(imx_ep->imx_usb->dev, "<%s> bad ep\n", __func__);
		return -ENODEV;
	}

	if (imx_ep->imx_usb->gadget.speed == USB_SPEED_UNKNOWN)
		return 0;
	else
		return imx_fifo_bcount(imx_ep);
}

static void imx_ep_fifo_flush(struct usb_ep *usb_ep)
{
	struct imx_ep_struct *imx_ep = container_of
					(usb_ep, struct imx_ep_struct, ep);
	unsigned long flags;

	local_irq_save(flags);

	if (!usb_ep || !EP_NO(imx_ep) || !list_empty(&imx_ep->queue)) {
		D_ERR(imx_ep->imx_usb->dev, "<%s> bad ep\n", __func__);
		local_irq_restore(flags);
		return;
	}

	/* toggle and halt bits stay unchanged */
	imx_flush(imx_ep);

	local_irq_restore(flags);
}

static struct usb_ep_ops imx_ep_ops = {
	.enable		= imx_ep_enable,
	.disable	= imx_ep_disable,

	.alloc_request	= imx_ep_alloc_request,
	.free_request	= imx_ep_free_request,

	.queue		= imx_ep_queue,
	.dequeue	= imx_ep_dequeue,

	.set_halt	= imx_ep_set_halt,
	.fifo_status	= imx_ep_fifo_status,
	.fifo_flush	= imx_ep_fifo_flush,
};

/*******************************************************************************
 * USB endpoint control functions
 *******************************************************************************
 */

void ep0_chg_stat(const char *label,
			struct imx_udc_struct *imx_usb, enum ep0_state stat)
{
	D_EP0(imx_usb->dev, "<%s> from %15s to %15s\n",
		label, state_name[imx_usb->ep0state], state_name[stat]);

	if (imx_usb->ep0state == stat)
		return;

	imx_usb->ep0state = stat;
}

static void usb_init_data(struct imx_udc_struct *imx_usb)
{
	struct imx_ep_struct *imx_ep;
	u8 i;

	/* device/ep0 records init */
	INIT_LIST_HEAD(&imx_usb->gadget.ep_list);
	INIT_LIST_HEAD(&imx_usb->gadget.ep0->ep_list);
	ep0_chg_stat(__func__, imx_usb, EP0_IDLE);

	/* basic endpoint records init */
	for (i = 0; i < IMX_USB_NB_EP; i++) {
		imx_ep = &imx_usb->imx_ep[i];

		if (i) {
			list_add_tail(&imx_ep->ep.ep_list,
				&imx_usb->gadget.ep_list);
			imx_ep->stopped = 1;
		} else
			imx_ep->stopped = 0;

		INIT_LIST_HEAD(&imx_ep->queue);
	}
}

static void udc_stop_activity(struct imx_udc_struct *imx_usb,
					struct usb_gadget_driver *driver)
{
	struct imx_ep_struct *imx_ep;
	int i;

	if (imx_usb->gadget.speed == USB_SPEED_UNKNOWN)
		driver = NULL;

	/* prevent new request submissions, kill any outstanding requests  */
	for (i = 1; i < IMX_USB_NB_EP; i++) {
		imx_ep = &imx_usb->imx_ep[i];
		imx_flush(imx_ep);
		imx_ep->stopped = 1;
		imx_ep_irq_disable(imx_ep);
		nuke(imx_ep, -ESHUTDOWN);
	}

	imx_usb->cfg = 0;
	imx_usb->intf = 0;
	imx_usb->alt = 0;

	if (driver)
		driver->disconnect(&imx_usb->gadget);
}

/*******************************************************************************
 * Interrupt handlers
 *******************************************************************************
 */

/*
 * Called when timer expires.
 * Timer is started when CFG_CHG is received.
 */
static void handle_config(unsigned long data)
{
	struct imx_udc_struct *imx_usb = (void *)data;
	struct usb_ctrlrequest u;
	int temp, cfg, intf, alt;

	local_irq_disable();

	temp = __raw_readl(imx_usb->base + USB_STAT);
	cfg  = (temp & STAT_CFG) >> 5;
	intf = (temp & STAT_INTF) >> 3;
	alt  =  temp & STAT_ALTSET;

	D_REQ(imx_usb->dev,
		"<%s> orig config C=%d, I=%d, A=%d / "
		"req config C=%d, I=%d, A=%d\n",
		__func__, imx_usb->cfg, imx_usb->intf, imx_usb->alt,
		cfg, intf, alt);

	if (cfg == 1 || cfg == 2) {

		if (imx_usb->cfg != cfg) {
			u.bRequest = USB_REQ_SET_CONFIGURATION;
			u.bRequestType = USB_DIR_OUT |
					USB_TYPE_STANDARD |
					USB_RECIP_DEVICE;
			u.wValue = cfg;
			u.wIndex = 0;
			u.wLength = 0;
			imx_usb->cfg = cfg;
			imx_usb->driver->setup(&imx_usb->gadget, &u);

		}
		if (imx_usb->intf != intf || imx_usb->alt != alt) {
			u.bRequest = USB_REQ_SET_INTERFACE;
			u.bRequestType = USB_DIR_OUT |
					  USB_TYPE_STANDARD |
					  USB_RECIP_INTERFACE;
			u.wValue = alt;
			u.wIndex = intf;
			u.wLength = 0;
			imx_usb->intf = intf;
			imx_usb->alt = alt;
			imx_usb->driver->setup(&imx_usb->gadget, &u);
		}
	}

	imx_usb->set_config = 0;

	local_irq_enable();
}

static irqreturn_t imx_udc_irq(int irq, void *dev)
{
	struct imx_udc_struct *imx_usb = dev;
	int intr = __raw_readl(imx_usb->base + USB_INTR);
	int temp;

	if (intr & (INTR_WAKEUP | INTR_SUSPEND | INTR_RESUME | INTR_RESET_START
			| INTR_RESET_STOP | INTR_CFG_CHG)) {
				dump_intr(__func__, intr, imx_usb->dev);
				dump_usb_stat(__func__, imx_usb);
	}

	if (!imx_usb->driver)
		goto end_irq;

	if (intr & INTR_SOF) {
		/* Copy from Freescale BSP.
		   We must enable SOF intr and set CMDOVER.
		   Datasheet don't specifiy this action, but it
		   is done in Freescale BSP, so just copy it.
		*/
		if (imx_usb->ep0state == EP0_IDLE) {
			temp = __raw_readl(imx_usb->base + USB_CTRL);
			__raw_writel(temp | CTRL_CMDOVER,
						imx_usb->base + USB_CTRL);
		}
	}

	if (intr & INTR_CFG_CHG) {
		/* A workaround of serious IMX UDC bug.
		   Handling of CFG_CHG should be delayed for some time, because
		   IMX does not NACK the host when CFG_CHG interrupt is pending.
		   There is no time to handle current CFG_CHG
		   if next CFG_CHG or SETUP packed is send immediately.
		   We have to clear CFG_CHG, start the timer and
		   NACK the host by setting CTRL_CMDOVER
		   if it sends any SETUP packet.
		   When timer expires, handler is called to handle configuration
		   changes. While CFG_CHG is not handled (set_config=1),
		   we must NACK the host to every SETUP packed.
		   This delay prevents from going out of sync with host.
		 */
		__raw_writel(INTR_CFG_CHG, imx_usb->base + USB_INTR);
		imx_usb->set_config = 1;
		mod_timer(&imx_usb->timer, jiffies + 5);
		goto end_irq;
	}

	if (intr & INTR_WAKEUP) {
		if (imx_usb->gadget.speed == USB_SPEED_UNKNOWN
			&& imx_usb->driver && imx_usb->driver->resume)
				imx_usb->driver->resume(&imx_usb->gadget);
		imx_usb->set_config = 0;
		del_timer(&imx_usb->timer);
		imx_usb->gadget.speed = USB_SPEED_FULL;
	}

	if (intr & INTR_SUSPEND) {
		if (imx_usb->gadget.speed != USB_SPEED_UNKNOWN
			&& imx_usb->driver && imx_usb->driver->suspend)
				imx_usb->driver->suspend(&imx_usb->gadget);
		imx_usb->set_config = 0;
		del_timer(&imx_usb->timer);
		imx_usb->gadget.speed = USB_SPEED_UNKNOWN;
	}

	if (intr & INTR_RESET_START) {
		__raw_writel(intr, imx_usb->base + USB_INTR);
		udc_stop_activity(imx_usb, imx_usb->driver);
		imx_usb->set_config = 0;
		del_timer(&imx_usb->timer);
		imx_usb->gadget.speed = USB_SPEED_UNKNOWN;
	}

	if (intr & INTR_RESET_STOP)
		imx_usb->gadget.speed = USB_SPEED_FULL;

end_irq:
	__raw_writel(intr, imx_usb->base + USB_INTR);
	return IRQ_HANDLED;
}

static irqreturn_t imx_udc_ctrl_irq(int irq, void *dev)
{
	struct imx_udc_struct *imx_usb = dev;
	struct imx_ep_struct *imx_ep = &imx_usb->imx_ep[0];
	int intr = __raw_readl(imx_usb->base + USB_EP_INTR(0));

	dump_ep_intr(__func__, 0, intr, imx_usb->dev);

	if (!imx_usb->driver) {
		__raw_writel(intr, imx_usb->base + USB_EP_INTR(0));
		return IRQ_HANDLED;
	}

	/* DEVREQ has highest priority */
	if (intr & (EPINTR_DEVREQ | EPINTR_MDEVREQ))
		handle_ep0_devreq(imx_usb);
	/* Seem i.MX is missing EOF interrupt sometimes.
	 * Therefore we don't monitor EOF.
	 * We call handle_ep0() only if a request is queued for ep0.
	 */
	else if (!list_empty(&imx_ep->queue))
		handle_ep0(imx_ep);

	__raw_writel(intr, imx_usb->base + USB_EP_INTR(0));

	return IRQ_HANDLED;
}

#ifndef MX1_INT_USBD0
#define MX1_INT_USBD0 MX1_USBD_INT0
#endif

static irqreturn_t imx_udc_bulk_irq(int irq, void *dev)
{
	struct imx_udc_struct *imx_usb = dev;
	struct imx_ep_struct *imx_ep = &imx_usb->imx_ep[irq - MX1_INT_USBD0];
	int intr = __raw_readl(imx_usb->base + USB_EP_INTR(EP_NO(imx_ep)));

	dump_ep_intr(__func__, irq - MX1_INT_USBD0, intr, imx_usb->dev);

	if (!imx_usb->driver) {
		__raw_writel(intr, imx_usb->base + USB_EP_INTR(EP_NO(imx_ep)));
		return IRQ_HANDLED;
	}

	handle_ep(imx_ep);

	__raw_writel(intr, imx_usb->base + USB_EP_INTR(EP_NO(imx_ep)));

	return IRQ_HANDLED;
}

irq_handler_t intr_handler(int i)
{
	switch (i) {
	case 0:
		return imx_udc_ctrl_irq;
	case 1:
	case 2:
	case 3:
	case 4:
	case 5:
		return imx_udc_bulk_irq;
	default:
		return imx_udc_irq;
	}
}

/*******************************************************************************
 * Static defined IMX UDC structure
 *******************************************************************************
 */

static int imx_udc_start(struct usb_gadget_driver *driver,
		int (*bind)(struct usb_gadget *));
static int imx_udc_stop(struct usb_gadget_driver *driver);
static const struct usb_gadget_ops imx_udc_ops = {
	.get_frame	 = imx_udc_get_frame,
	.wakeup		 = imx_udc_wakeup,
	.start		= imx_udc_start,
	.stop		= imx_udc_stop,
};

static struct imx_udc_struct controller = {
	.gadget = {
		.ops		= &imx_udc_ops,
		.ep0		= &controller.imx_ep[0].ep,
		.name		= driver_name,
		.dev = {
			.init_name	= "gadget",
		},
	},

	.imx_ep[0] = {
		.ep = {
			.name		= ep0name,
			.ops		= &imx_ep_ops,
			.maxpacket	= 32,
		},
		.imx_usb		= &controller,
		.fifosize		= 32,
		.bEndpointAddress	= 0,
		.bmAttributes		= USB_ENDPOINT_XFER_CONTROL,
	 },
	.imx_ep[1] = {
		.ep = {
			.name		= "ep1in-bulk",
			.ops		= &imx_ep_ops,
			.maxpacket	= 64,
		},
		.imx_usb		= &controller,
		.fifosize		= 64,
		.bEndpointAddress	= USB_DIR_IN | 1,
		.bmAttributes		= USB_ENDPOINT_XFER_BULK,
	 },
	.imx_ep[2] = {
		.ep = {
			.name		= "ep2out-bulk",
			.ops		= &imx_ep_ops,
			.maxpacket	= 64,
		},
		.imx_usb		= &controller,
		.fifosize		= 64,
		.bEndpointAddress	= USB_DIR_OUT | 2,
		.bmAttributes		= USB_ENDPOINT_XFER_BULK,
	 },
	.imx_ep[3] = {
		.ep = {
			.name		= "ep3out-bulk",
			.ops		= &imx_ep_ops,
			.maxpacket	= 32,
		},
		.imx_usb		= &controller,
		.fifosize		= 32,
		.bEndpointAddress 	= USB_DIR_OUT | 3,
		.bmAttributes		= USB_ENDPOINT_XFER_BULK,
	 },
	.imx_ep[4] = {
		.ep = {
			.name		= "ep4in-int",
			.ops		= &imx_ep_ops,
			.maxpacket	= 32,
		 },
		.imx_usb		= &controller,
		.fifosize		= 32,
		.bEndpointAddress 	= USB_DIR_IN | 4,
		.bmAttributes		= USB_ENDPOINT_XFER_INT,
	 },
	.imx_ep[5] = {
		.ep = {
			.name		= "ep5out-int",
			.ops		= &imx_ep_ops,
			.maxpacket	= 32,
		},
		.imx_usb		= &controller,
		.fifosize		= 32,
		.bEndpointAddress 	= USB_DIR_OUT | 5,
		.bmAttributes		= USB_ENDPOINT_XFER_INT,
	 },
};

/*******************************************************************************
 * USB gadget driver functions
 *******************************************************************************
 */
static int imx_udc_start(struct usb_gadget_driver *driver,
		int (*bind)(struct usb_gadget *))
{
	struct imx_udc_struct *imx_usb = &controller;
	int retval;

	if (!driver
		|| driver->max_speed < USB_SPEED_FULL
		|| !bind
		|| !driver->disconnect
		|| !driver->setup)
			return -EINVAL;
	if (!imx_usb)
		return -ENODEV;
	if (imx_usb->driver)
		return -EBUSY;

	/* first hook up the driver ... */
	imx_usb->driver = driver;
	imx_usb->gadget.dev.driver = &driver->driver;

	retval = device_add(&imx_usb->gadget.dev);
	if (retval)
		goto fail;
	retval = bind(&imx_usb->gadget);
	if (retval) {
		D_ERR(imx_usb->dev, "<%s> bind to driver %s --> error %d\n",
			__func__, driver->driver.name, retval);
		device_del(&imx_usb->gadget.dev);

		goto fail;
	}

	D_INI(imx_usb->dev, "<%s> registered gadget driver '%s'\n",
		__func__, driver->driver.name);

	imx_udc_enable(imx_usb);

	return 0;
fail:
	imx_usb->driver = NULL;
	imx_usb->gadget.dev.driver = NULL;
	return retval;
}

static int imx_udc_stop(struct usb_gadget_driver *driver)
{
	struct imx_udc_struct *imx_usb = &controller;

	if (!imx_usb)
		return -ENODEV;
	if (!driver || driver != imx_usb->driver || !driver->unbind)
		return -EINVAL;

	udc_stop_activity(imx_usb, driver);
	imx_udc_disable(imx_usb);
	del_timer(&imx_usb->timer);

	driver->unbind(&imx_usb->gadget);
	imx_usb->gadget.dev.driver = NULL;
	imx_usb->driver = NULL;

	device_del(&imx_usb->gadget.dev);

	D_INI(imx_usb->dev, "<%s> unregistered gadget driver '%s'\n",
		__func__, driver->driver.name);

	return 0;
}

/*******************************************************************************
 * Module functions
 *******************************************************************************
 */

static int __init imx_udc_probe(struct platform_device *pdev)
{
	struct imx_udc_struct *imx_usb = &controller;
	struct resource *res;
	struct imxusb_platform_data *pdata;
	struct clk *clk;
	void __iomem *base;
	int ret = 0;
	int i;
	resource_size_t res_size;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!res) {
		dev_err(&pdev->dev, "can't get device resources\n");
		return -ENODEV;
	}

	pdata = pdev->dev.platform_data;
	if (!pdata) {
		dev_err(&pdev->dev, "driver needs platform data\n");
		return -ENODEV;
	}

	res_size = resource_size(res);
	if (!request_mem_region(res->start, res_size, res->name)) {
		dev_err(&pdev->dev, "can't allocate %d bytes at %d address\n",
			res_size, res->start);
		return -ENOMEM;
	}

	if (pdata->init) {
		ret = pdata->init(&pdev->dev);
		if (ret)
			goto fail0;
	}

	base = ioremap(res->start, res_size);
	if (!base) {
		dev_err(&pdev->dev, "ioremap failed\n");
		ret = -EIO;
		goto fail1;
	}

	clk = clk_get(NULL, "usbd_clk");
	if (IS_ERR(clk)) {
		ret = PTR_ERR(clk);
		dev_err(&pdev->dev, "can't get USB clock\n");
		goto fail2;
	}
	clk_enable(clk);

	if (clk_get_rate(clk) != 48000000) {
		D_INI(&pdev->dev,
			"Bad USB clock (%d Hz), changing to 48000000 Hz\n",
			(int)clk_get_rate(clk));
		if (clk_set_rate(clk, 48000000)) {
			dev_err(&pdev->dev,
				"Unable to set correct USB clock (48MHz)\n");
			ret = -EIO;
			goto fail3;
		}
	}

	for (i = 0; i < IMX_USB_NB_EP + 1; i++) {
		imx_usb->usbd_int[i] = platform_get_irq(pdev, i);
		if (imx_usb->usbd_int[i] < 0) {
			dev_err(&pdev->dev, "can't get irq number\n");
			ret = -ENODEV;
			goto fail3;
		}
	}

	for (i = 0; i < IMX_USB_NB_EP + 1; i++) {
		ret = request_irq(imx_usb->usbd_int[i], intr_handler(i),
				     0, driver_name, imx_usb);
		if (ret) {
			dev_err(&pdev->dev, "can't get irq %i, err %d\n",
				imx_usb->usbd_int[i], ret);
			for (--i; i >= 0; i--)
				free_irq(imx_usb->usbd_int[i], imx_usb);
			goto fail3;
		}
	}

	imx_usb->res = res;
	imx_usb->base = base;
	imx_usb->clk = clk;
	imx_usb->dev = &pdev->dev;

	device_initialize(&imx_usb->gadget.dev);

	imx_usb->gadget.dev.parent = &pdev->dev;
	imx_usb->gadget.dev.dma_mask = pdev->dev.dma_mask;

	platform_set_drvdata(pdev, imx_usb);

	usb_init_data(imx_usb);
	imx_udc_init(imx_usb);

	init_timer(&imx_usb->timer);
	imx_usb->timer.function = handle_config;
	imx_usb->timer.data = (unsigned long)imx_usb;

	ret = usb_add_gadget_udc(&pdev->dev, &imx_usb->gadget);
	if (ret)
		goto fail4;

	return 0;
fail4:
	for (i = 0; i < IMX_USB_NB_EP + 1; i++)
		free_irq(imx_usb->usbd_int[i], imx_usb);
fail3:
	clk_put(clk);
	clk_disable(clk);
fail2:
	iounmap(base);
fail1:
	if (pdata->exit)
		pdata->exit(&pdev->dev);
fail0:
	release_mem_region(res->start, res_size);
	return ret;
}

static int __exit imx_udc_remove(struct platform_device *pdev)
{
	struct imx_udc_struct *imx_usb = platform_get_drvdata(pdev);
	struct imxusb_platform_data *pdata = pdev->dev.platform_data;
	int i;

	usb_del_gadget_udc(&imx_usb->gadget);
	imx_udc_disable(imx_usb);
	del_timer(&imx_usb->timer);

	for (i = 0; i < IMX_USB_NB_EP + 1; i++)
		free_irq(imx_usb->usbd_int[i], imx_usb);

	clk_put(imx_usb->clk);
	clk_disable(imx_usb->clk);
	iounmap(imx_usb->base);

	release_mem_region(imx_usb->res->start, resource_size(imx_usb->res));

	if (pdata->exit)
		pdata->exit(&pdev->dev);

	platform_set_drvdata(pdev, NULL);

	return 0;
}

/*----------------------------------------------------------------------------*/

#ifdef	CONFIG_PM
#define	imx_udc_suspend	NULL
#define	imx_udc_resume	NULL
#else
#define	imx_udc_suspend	NULL
#define	imx_udc_resume	NULL
#endif

/*----------------------------------------------------------------------------*/

static struct platform_driver udc_driver = {
	.driver		= {
		.name	= driver_name,
		.owner	= THIS_MODULE,
	},
	.remove		= __exit_p(imx_udc_remove),
	.suspend	= imx_udc_suspend,
	.resume		= imx_udc_resume,
};

static int __init udc_init(void)
{
	return platform_driver_probe(&udc_driver, imx_udc_probe);
}
module_init(udc_init);

static void __exit udc_exit(void)
{
	platform_driver_unregister(&udc_driver);
}
module_exit(udc_exit);

MODULE_DESCRIPTION("IMX USB Device Controller driver");
MODULE_AUTHOR("Darius Augulis <augulis.darius@gmail.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:imx_udc");
