// SPDX-License-Identifier: GPL-2.0+
/*
 * Driver for PLX NET2272 USB device controller
 *
 * Copyright (C) 2005-2006 PLX Technology, Inc.
 * Copyright (C) 2006-2011 Analog Devices, Inc.
 */

#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/pci.h>
#include <linux/platform_device.h>
#include <linux/prefetch.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/usb.h>
#include <linux/usb/ch9.h>
#include <linux/usb/gadget.h>

#include <asm/byteorder.h>
#include <asm/unaligned.h>

#include "net2272.h"

#define DRIVER_DESC "PLX NET2272 USB Peripheral Controller"

static const char driver_name[] = "net2272";
static const char driver_vers[] = "2006 October 17/mainline";
static const char driver_desc[] = DRIVER_DESC;

static const char ep0name[] = "ep0";
static const char * const ep_name[] = {
	ep0name,
	"ep-a", "ep-b", "ep-c",
};

#ifdef CONFIG_USB_NET2272_DMA
/*
 * use_dma: the NET2272 can use an external DMA controller.
 * Note that since there is no generic DMA api, some functions,
 * notably request_dma, start_dma, and cancel_dma will need to be
 * modified for your platform's particular dma controller.
 *
 * If use_dma is disabled, pio will be used instead.
 */
static bool use_dma = 0;
module_param(use_dma, bool, 0644);

/*
 * dma_ep: selects the endpoint for use with dma (1=ep-a, 2=ep-b)
 * The NET2272 can only use dma for a single endpoint at a time.
 * At some point this could be modified to allow either endpoint
 * to take control of dma as it becomes available.
 *
 * Note that DMA should not be used on OUT endpoints unless it can
 * be guaranteed that no short packets will arrive on an IN endpoint
 * while the DMA operation is pending.  Otherwise the OUT DMA will
 * terminate prematurely (See NET2272 Errata 630-0213-0101)
 */
static ushort dma_ep = 1;
module_param(dma_ep, ushort, 0644);

/*
 * dma_mode: net2272 dma mode setting (see LOCCTL1 definiton):
 *	mode 0 == Slow DREQ mode
 *	mode 1 == Fast DREQ mode
 *	mode 2 == Burst mode
 */
static ushort dma_mode = 2;
module_param(dma_mode, ushort, 0644);
#else
#define use_dma 0
#define dma_ep 1
#define dma_mode 2
#endif

/*
 * fifo_mode: net2272 buffer configuration:
 *      mode 0 == ep-{a,b,c} 512db each
 *      mode 1 == ep-a 1k, ep-{b,c} 512db
 *      mode 2 == ep-a 1k, ep-b 1k, ep-c 512db
 *      mode 3 == ep-a 1k, ep-b disabled, ep-c 512db
 */
static ushort fifo_mode = 0;
module_param(fifo_mode, ushort, 0644);

/*
 * enable_suspend: When enabled, the driver will respond to
 * USB suspend requests by powering down the NET2272.  Otherwise,
 * USB suspend requests will be ignored.  This is acceptible for
 * self-powered devices.  For bus powered devices set this to 1.
 */
static ushort enable_suspend = 0;
module_param(enable_suspend, ushort, 0644);

static void assert_out_naking(struct net2272_ep *ep, const char *where)
{
	u8 tmp;

#ifndef DEBUG
	return;
#endif

	tmp = net2272_ep_read(ep, EP_STAT0);
	if ((tmp & (1 << NAK_OUT_PACKETS)) == 0) {
		dev_dbg(ep->dev->dev, "%s %s %02x !NAK\n",
			ep->ep.name, where, tmp);
		net2272_ep_write(ep, EP_RSPSET, 1 << ALT_NAK_OUT_PACKETS);
	}
}
#define ASSERT_OUT_NAKING(ep) assert_out_naking(ep, __func__)

static void stop_out_naking(struct net2272_ep *ep)
{
	u8 tmp = net2272_ep_read(ep, EP_STAT0);

	if ((tmp & (1 << NAK_OUT_PACKETS)) != 0)
		net2272_ep_write(ep, EP_RSPCLR, 1 << ALT_NAK_OUT_PACKETS);
}

#define PIPEDIR(bAddress) (usb_pipein(bAddress) ? "in" : "out")

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 "intr";
	default:                     return "control";
	}
}

static char *buf_state_string(unsigned state)
{
	switch (state) {
	case BUFF_FREE:  return "free";
	case BUFF_VALID: return "valid";
	case BUFF_LCL:   return "local";
	case BUFF_USB:   return "usb";
	default:         return "unknown";
	}
}

static char *dma_mode_string(void)
{
	if (!use_dma)
		return "PIO";
	switch (dma_mode) {
	case 0:  return "SLOW DREQ";
	case 1:  return "FAST DREQ";
	case 2:  return "BURST";
	default: return "invalid";
	}
}

static void net2272_dequeue_all(struct net2272_ep *);
static int net2272_kick_dma(struct net2272_ep *, struct net2272_request *);
static int net2272_fifo_status(struct usb_ep *);

static const struct usb_ep_ops net2272_ep_ops;

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

static int
net2272_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
{
	struct net2272 *dev;
	struct net2272_ep *ep;
	u32 max;
	u8 tmp;
	unsigned long flags;

	ep = container_of(_ep, struct net2272_ep, ep);
	if (!_ep || !desc || ep->desc || _ep->name == ep0name
			|| desc->bDescriptorType != USB_DT_ENDPOINT)
		return -EINVAL;
	dev = ep->dev;
	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;

	max = usb_endpoint_maxp(desc);

	spin_lock_irqsave(&dev->lock, flags);
	_ep->maxpacket = max;
	ep->desc = desc;

	/* net2272_ep_reset() has already been called */
	ep->stopped = 0;
	ep->wedged = 0;

	/* set speed-dependent max packet */
	net2272_ep_write(ep, EP_MAXPKT0, max & 0xff);
	net2272_ep_write(ep, EP_MAXPKT1, (max & 0xff00) >> 8);

	/* set type, direction, address; reset fifo counters */
	net2272_ep_write(ep, EP_STAT1, 1 << BUFFER_FLUSH);
	tmp = usb_endpoint_type(desc);
	if (usb_endpoint_xfer_bulk(desc)) {
		/* catch some particularly blatant driver bugs */
		if ((dev->gadget.speed == USB_SPEED_HIGH && max != 512) ||
		    (dev->gadget.speed == USB_SPEED_FULL && max > 64)) {
			spin_unlock_irqrestore(&dev->lock, flags);
			return -ERANGE;
		}
	}
	ep->is_iso = usb_endpoint_xfer_isoc(desc) ? 1 : 0;
	tmp <<= ENDPOINT_TYPE;
	tmp |= ((desc->bEndpointAddress & 0x0f) << ENDPOINT_NUMBER);
	tmp |= usb_endpoint_dir_in(desc) << ENDPOINT_DIRECTION;
	tmp |= (1 << ENDPOINT_ENABLE);

	/* for OUT transfers, block the rx fifo until a read is posted */
	ep->is_in = usb_endpoint_dir_in(desc);
	if (!ep->is_in)
		net2272_ep_write(ep, EP_RSPSET, 1 << ALT_NAK_OUT_PACKETS);

	net2272_ep_write(ep, EP_CFG, tmp);

	/* enable irqs */
	tmp = (1 << ep->num) | net2272_read(dev, IRQENB0);
	net2272_write(dev, IRQENB0, tmp);

	tmp = (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
		| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE)
		| net2272_ep_read(ep, EP_IRQENB);
	net2272_ep_write(ep, EP_IRQENB, tmp);

	tmp = desc->bEndpointAddress;
	dev_dbg(dev->dev, "enabled %s (ep%d%s-%s) max %04x cfg %02x\n",
		_ep->name, tmp & 0x0f, PIPEDIR(tmp),
		type_string(desc->bmAttributes), max,
		net2272_ep_read(ep, EP_CFG));

	spin_unlock_irqrestore(&dev->lock, flags);
	return 0;
}

static void net2272_ep_reset(struct net2272_ep *ep)
{
	u8 tmp;

	ep->desc = NULL;
	INIT_LIST_HEAD(&ep->queue);

	usb_ep_set_maxpacket_limit(&ep->ep, ~0);
	ep->ep.ops = &net2272_ep_ops;

	/* disable irqs, endpoint */
	net2272_ep_write(ep, EP_IRQENB, 0);

	/* init to our chosen defaults, notably so that we NAK OUT
	 * packets until the driver queues a read.
	 */
	tmp = (1 << NAK_OUT_PACKETS_MODE) | (1 << ALT_NAK_OUT_PACKETS);
	net2272_ep_write(ep, EP_RSPSET, tmp);

	tmp = (1 << INTERRUPT_MODE) | (1 << HIDE_STATUS_PHASE);
	if (ep->num != 0)
		tmp |= (1 << ENDPOINT_TOGGLE) | (1 << ENDPOINT_HALT);

	net2272_ep_write(ep, EP_RSPCLR, tmp);

	/* scrub most status bits, and flush any fifo state */
	net2272_ep_write(ep, EP_STAT0,
			  (1 << DATA_IN_TOKEN_INTERRUPT)
			| (1 << DATA_OUT_TOKEN_INTERRUPT)
			| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
			| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
			| (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT));

	net2272_ep_write(ep, EP_STAT1,
			    (1 << TIMEOUT)
			  | (1 << USB_OUT_ACK_SENT)
			  | (1 << USB_OUT_NAK_SENT)
			  | (1 << USB_IN_ACK_RCVD)
			  | (1 << USB_IN_NAK_SENT)
			  | (1 << USB_STALL_SENT)
			  | (1 << LOCAL_OUT_ZLP)
			  | (1 << BUFFER_FLUSH));

	/* fifo size is handled seperately */
}

static int net2272_disable(struct usb_ep *_ep)
{
	struct net2272_ep *ep;
	unsigned long flags;

	ep = container_of(_ep, struct net2272_ep, ep);
	if (!_ep || !ep->desc || _ep->name == ep0name)
		return -EINVAL;

	spin_lock_irqsave(&ep->dev->lock, flags);
	net2272_dequeue_all(ep);
	net2272_ep_reset(ep);

	dev_vdbg(ep->dev->dev, "disabled %s\n", _ep->name);

	spin_unlock_irqrestore(&ep->dev->lock, flags);
	return 0;
}

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

static struct usb_request *
net2272_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
{
	struct net2272_request *req;

	if (!_ep)
		return NULL;

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

	INIT_LIST_HEAD(&req->queue);

	return &req->req;
}

static void
net2272_free_request(struct usb_ep *_ep, struct usb_request *_req)
{
	struct net2272_request *req;

	if (!_ep || !_req)
		return;

	req = container_of(_req, struct net2272_request, req);
	WARN_ON(!list_empty(&req->queue));
	kfree(req);
}

static void
net2272_done(struct net2272_ep *ep, struct net2272_request *req, int status)
{
	struct net2272 *dev;
	unsigned stopped = ep->stopped;

	if (ep->num == 0) {
		if (ep->dev->protocol_stall) {
			ep->stopped = 1;
			set_halt(ep);
		}
		allow_status(ep);
	}

	list_del_init(&req->queue);

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

	dev = ep->dev;
	if (use_dma && ep->dma)
		usb_gadget_unmap_request(&dev->gadget, &req->req,
				ep->is_in);

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

	/* don't modify queue heads during completion callback */
	ep->stopped = 1;
	spin_unlock(&dev->lock);
	usb_gadget_giveback_request(&ep->ep, &req->req);
	spin_lock(&dev->lock);
	ep->stopped = stopped;
}

static int
net2272_write_packet(struct net2272_ep *ep, u8 *buf,
	struct net2272_request *req, unsigned max)
{
	u16 __iomem *ep_data = net2272_reg_addr(ep->dev, EP_DATA);
	u16 *bufp;
	unsigned length, count;
	u8 tmp;

	length = min(req->req.length - req->req.actual, max);
	req->req.actual += length;

	dev_vdbg(ep->dev->dev, "write packet %s req %p max %u len %u avail %u\n",
		ep->ep.name, req, max, length,
		(net2272_ep_read(ep, EP_AVAIL1) << 8) | net2272_ep_read(ep, EP_AVAIL0));

	count = length;
	bufp = (u16 *)buf;

	while (likely(count >= 2)) {
		/* no byte-swap required; chip endian set during init */
		writew(*bufp++, ep_data);
		count -= 2;
	}
	buf = (u8 *)bufp;

	/* write final byte by placing the NET2272 into 8-bit mode */
	if (unlikely(count)) {
		tmp = net2272_read(ep->dev, LOCCTL);
		net2272_write(ep->dev, LOCCTL, tmp & ~(1 << DATA_WIDTH));
		writeb(*buf, ep_data);
		net2272_write(ep->dev, LOCCTL, tmp);
	}
	return length;
}

/* returns: 0: still running, 1: completed, negative: errno */
static int
net2272_write_fifo(struct net2272_ep *ep, struct net2272_request *req)
{
	u8 *buf;
	unsigned count, max;
	int status;

	dev_vdbg(ep->dev->dev, "write_fifo %s actual %d len %d\n",
		ep->ep.name, req->req.actual, req->req.length);

	/*
	 * Keep loading the endpoint until the final packet is loaded,
	 * or the endpoint buffer is full.
	 */
 top:
	/*
	 * Clear interrupt status
	 *  - Packet Transmitted interrupt will become set again when the
	 *    host successfully takes another packet
	 */
	net2272_ep_write(ep, EP_STAT0, (1 << DATA_PACKET_TRANSMITTED_INTERRUPT));
	while (!(net2272_ep_read(ep, EP_STAT0) & (1 << BUFFER_FULL))) {
		buf = req->req.buf + req->req.actual;
		prefetch(buf);

		/* force pagesel */
		net2272_ep_read(ep, EP_STAT0);

		max = (net2272_ep_read(ep, EP_AVAIL1) << 8) |
			(net2272_ep_read(ep, EP_AVAIL0));

		if (max < ep->ep.maxpacket)
			max = (net2272_ep_read(ep, EP_AVAIL1) << 8)
				| (net2272_ep_read(ep, EP_AVAIL0));

		count = net2272_write_packet(ep, buf, req, max);
		/* see if we are done */
		if (req->req.length == req->req.actual) {
			/* validate short or zlp packet */
			if (count < ep->ep.maxpacket)
				set_fifo_bytecount(ep, 0);
			net2272_done(ep, req, 0);

			if (!list_empty(&ep->queue)) {
				req = list_entry(ep->queue.next,
						struct net2272_request,
						queue);
				status = net2272_kick_dma(ep, req);

				if (status < 0)
					if ((net2272_ep_read(ep, EP_STAT0)
							& (1 << BUFFER_EMPTY)))
						goto top;
			}
			return 1;
		}
		net2272_ep_write(ep, EP_STAT0, (1 << DATA_PACKET_TRANSMITTED_INTERRUPT));
	}
	return 0;
}

static void
net2272_out_flush(struct net2272_ep *ep)
{
	ASSERT_OUT_NAKING(ep);

	net2272_ep_write(ep, EP_STAT0, (1 << DATA_OUT_TOKEN_INTERRUPT)
			| (1 << DATA_PACKET_RECEIVED_INTERRUPT));
	net2272_ep_write(ep, EP_STAT1, 1 << BUFFER_FLUSH);
}

static int
net2272_read_packet(struct net2272_ep *ep, u8 *buf,
	struct net2272_request *req, unsigned avail)
{
	u16 __iomem *ep_data = net2272_reg_addr(ep->dev, EP_DATA);
	unsigned is_short;
	u16 *bufp;

	req->req.actual += avail;

	dev_vdbg(ep->dev->dev, "read packet %s req %p len %u avail %u\n",
		ep->ep.name, req, avail,
		(net2272_ep_read(ep, EP_AVAIL1) << 8) | net2272_ep_read(ep, EP_AVAIL0));

	is_short = (avail < ep->ep.maxpacket);

	if (unlikely(avail == 0)) {
		/* remove any zlp from the buffer */
		(void)readw(ep_data);
		return is_short;
	}

	/* Ensure we get the final byte */
	if (unlikely(avail % 2))
		avail++;
	bufp = (u16 *)buf;

	do {
		*bufp++ = readw(ep_data);
		avail -= 2;
	} while (avail);

	/*
	 * To avoid false endpoint available race condition must read
	 * ep stat0 twice in the case of a short transfer
	 */
	if (net2272_ep_read(ep, EP_STAT0) & (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT))
		net2272_ep_read(ep, EP_STAT0);

	return is_short;
}

static int
net2272_read_fifo(struct net2272_ep *ep, struct net2272_request *req)
{
	u8 *buf;
	unsigned is_short;
	int count;
	int tmp;
	int cleanup = 0;
	int status = -1;

	dev_vdbg(ep->dev->dev, "read_fifo %s actual %d len %d\n",
		ep->ep.name, req->req.actual, req->req.length);

 top:
	do {
		buf = req->req.buf + req->req.actual;
		prefetchw(buf);

		count = (net2272_ep_read(ep, EP_AVAIL1) << 8)
			| net2272_ep_read(ep, EP_AVAIL0);

		net2272_ep_write(ep, EP_STAT0,
			(1 << SHORT_PACKET_TRANSFERRED_INTERRUPT) |
			(1 << DATA_PACKET_RECEIVED_INTERRUPT));

		tmp = req->req.length - req->req.actual;

		if (count > tmp) {
			if ((tmp % ep->ep.maxpacket) != 0) {
				dev_err(ep->dev->dev,
					"%s out fifo %d bytes, expected %d\n",
					ep->ep.name, count, tmp);
				cleanup = 1;
			}
			count = (tmp > 0) ? tmp : 0;
		}

		is_short = net2272_read_packet(ep, buf, req, count);

		/* completion */
		if (unlikely(cleanup || is_short ||
				req->req.actual == req->req.length)) {

			if (cleanup) {
				net2272_out_flush(ep);
				net2272_done(ep, req, -EOVERFLOW);
			} else
				net2272_done(ep, req, 0);

			/* re-initialize endpoint transfer registers
			 * otherwise they may result in erroneous pre-validation
			 * for subsequent control reads
			 */
			if (unlikely(ep->num == 0)) {
				net2272_ep_write(ep, EP_TRANSFER2, 0);
				net2272_ep_write(ep, EP_TRANSFER1, 0);
				net2272_ep_write(ep, EP_TRANSFER0, 0);
			}

			if (!list_empty(&ep->queue)) {
				req = list_entry(ep->queue.next,
					struct net2272_request, queue);
				status = net2272_kick_dma(ep, req);
				if ((status < 0) &&
				    !(net2272_ep_read(ep, EP_STAT0) & (1 << BUFFER_EMPTY)))
					goto top;
			}
			return 1;
		}
	} while (!(net2272_ep_read(ep, EP_STAT0) & (1 << BUFFER_EMPTY)));

	return 0;
}

static void
net2272_pio_advance(struct net2272_ep *ep)
{
	struct net2272_request *req;

	if (unlikely(list_empty(&ep->queue)))
		return;

	req = list_entry(ep->queue.next, struct net2272_request, queue);
	(ep->is_in ? net2272_write_fifo : net2272_read_fifo)(ep, req);
}

/* returns 0 on success, else negative errno */
static int
net2272_request_dma(struct net2272 *dev, unsigned ep, u32 buf,
	unsigned len, unsigned dir)
{
	dev_vdbg(dev->dev, "request_dma ep %d buf %08x len %d dir %d\n",
		ep, buf, len, dir);

	/* The NET2272 only supports a single dma channel */
	if (dev->dma_busy)
		return -EBUSY;
	/*
	 * EP_TRANSFER (used to determine the number of bytes received
	 * in an OUT transfer) is 24 bits wide; don't ask for more than that.
	 */
	if ((dir == 1) && (len > 0x1000000))
		return -EINVAL;

	dev->dma_busy = 1;

	/* initialize platform's dma */
#ifdef CONFIG_USB_PCI
	/* NET2272 addr, buffer addr, length, etc. */
	switch (dev->dev_id) {
	case PCI_DEVICE_ID_RDK1:
		/* Setup PLX 9054 DMA mode */
		writel((1 << LOCAL_BUS_WIDTH) |
			(1 << TA_READY_INPUT_ENABLE) |
			(0 << LOCAL_BURST_ENABLE) |
			(1 << DONE_INTERRUPT_ENABLE) |
			(1 << LOCAL_ADDRESSING_MODE) |
			(1 << DEMAND_MODE) |
			(1 << DMA_EOT_ENABLE) |
			(1 << FAST_SLOW_TERMINATE_MODE_SELECT) |
			(1 << DMA_CHANNEL_INTERRUPT_SELECT),
			dev->rdk1.plx9054_base_addr + DMAMODE0);

		writel(0x100000, dev->rdk1.plx9054_base_addr + DMALADR0);
		writel(buf, dev->rdk1.plx9054_base_addr + DMAPADR0);
		writel(len, dev->rdk1.plx9054_base_addr + DMASIZ0);
		writel((dir << DIRECTION_OF_TRANSFER) |
			(1 << INTERRUPT_AFTER_TERMINAL_COUNT),
			dev->rdk1.plx9054_base_addr + DMADPR0);
		writel((1 << LOCAL_DMA_CHANNEL_0_INTERRUPT_ENABLE) |
			readl(dev->rdk1.plx9054_base_addr + INTCSR),
			dev->rdk1.plx9054_base_addr + INTCSR);

		break;
	}
#endif

	net2272_write(dev, DMAREQ,
		(0 << DMA_BUFFER_VALID) |
		(1 << DMA_REQUEST_ENABLE) |
		(1 << DMA_CONTROL_DACK) |
		(dev->dma_eot_polarity << EOT_POLARITY) |
		(dev->dma_dack_polarity << DACK_POLARITY) |
		(dev->dma_dreq_polarity << DREQ_POLARITY) |
		((ep >> 1) << DMA_ENDPOINT_SELECT));

	(void) net2272_read(dev, SCRATCH);

	return 0;
}

static void
net2272_start_dma(struct net2272 *dev)
{
	/* start platform's dma controller */
#ifdef CONFIG_USB_PCI
	switch (dev->dev_id) {
	case PCI_DEVICE_ID_RDK1:
		writeb((1 << CHANNEL_ENABLE) | (1 << CHANNEL_START),
			dev->rdk1.plx9054_base_addr + DMACSR0);
		break;
	}
#endif
}

/* returns 0 on success, else negative errno */
static int
net2272_kick_dma(struct net2272_ep *ep, struct net2272_request *req)
{
	unsigned size;
	u8 tmp;

	if (!use_dma || (ep->num < 1) || (ep->num > 2) || !ep->dma)
		return -EINVAL;

	/* don't use dma for odd-length transfers
	 * otherwise, we'd need to deal with the last byte with pio
	 */
	if (req->req.length & 1)
		return -EINVAL;

	dev_vdbg(ep->dev->dev, "kick_dma %s req %p dma %08llx\n",
		ep->ep.name, req, (unsigned long long) req->req.dma);

	net2272_ep_write(ep, EP_RSPSET, 1 << ALT_NAK_OUT_PACKETS);

	/* The NET2272 can only use DMA on one endpoint at a time */
	if (ep->dev->dma_busy)
		return -EBUSY;

	/* Make sure we only DMA an even number of bytes (we'll use
	 * pio to complete the transfer)
	 */
	size = req->req.length;
	size &= ~1;

	/* device-to-host transfer */
	if (ep->is_in) {
		/* initialize platform's dma controller */
		if (net2272_request_dma(ep->dev, ep->num, req->req.dma, size, 0))
			/* unable to obtain DMA channel; return error and use pio mode */
			return -EBUSY;
		req->req.actual += size;

	/* host-to-device transfer */
	} else {
		tmp = net2272_ep_read(ep, EP_STAT0);

		/* initialize platform's dma controller */
		if (net2272_request_dma(ep->dev, ep->num, req->req.dma, size, 1))
			/* unable to obtain DMA channel; return error and use pio mode */
			return -EBUSY;

		if (!(tmp & (1 << BUFFER_EMPTY)))
			ep->not_empty = 1;
		else
			ep->not_empty = 0;


		/* allow the endpoint's buffer to fill */
		net2272_ep_write(ep, EP_RSPCLR, 1 << ALT_NAK_OUT_PACKETS);

		/* this transfer completed and data's already in the fifo
		 * return error so pio gets used.
		 */
		if (tmp & (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)) {

			/* deassert dreq */
			net2272_write(ep->dev, DMAREQ,
				(0 << DMA_BUFFER_VALID) |
				(0 << DMA_REQUEST_ENABLE) |
				(1 << DMA_CONTROL_DACK) |
				(ep->dev->dma_eot_polarity << EOT_POLARITY) |
				(ep->dev->dma_dack_polarity << DACK_POLARITY) |
				(ep->dev->dma_dreq_polarity << DREQ_POLARITY) |
				((ep->num >> 1) << DMA_ENDPOINT_SELECT));

			return -EBUSY;
		}
	}

	/* Don't use per-packet interrupts: use dma interrupts only */
	net2272_ep_write(ep, EP_IRQENB, 0);

	net2272_start_dma(ep->dev);

	return 0;
}

static void net2272_cancel_dma(struct net2272 *dev)
{
#ifdef CONFIG_USB_PCI
	switch (dev->dev_id) {
	case PCI_DEVICE_ID_RDK1:
		writeb(0, dev->rdk1.plx9054_base_addr + DMACSR0);
		writeb(1 << CHANNEL_ABORT, dev->rdk1.plx9054_base_addr + DMACSR0);
		while (!(readb(dev->rdk1.plx9054_base_addr + DMACSR0) &
		         (1 << CHANNEL_DONE)))
			continue;	/* wait for dma to stabalize */

		/* dma abort generates an interrupt */
		writeb(1 << CHANNEL_CLEAR_INTERRUPT,
			dev->rdk1.plx9054_base_addr + DMACSR0);
		break;
	}
#endif

	dev->dma_busy = 0;
}

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

static int
net2272_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
{
	struct net2272_request *req;
	struct net2272_ep *ep;
	struct net2272 *dev;
	unsigned long flags;
	int status = -1;
	u8 s;

	req = container_of(_req, struct net2272_request, req);
	if (!_req || !_req->complete || !_req->buf
			|| !list_empty(&req->queue))
		return -EINVAL;
	ep = container_of(_ep, struct net2272_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0))
		return -EINVAL;
	dev = ep->dev;
	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;

	/* set up dma mapping in case the caller didn't */
	if (use_dma && ep->dma) {
		status = usb_gadget_map_request(&dev->gadget, _req,
				ep->is_in);
		if (status)
			return status;
	}

	dev_vdbg(dev->dev, "%s queue req %p, len %d buf %p dma %08llx %s\n",
		_ep->name, _req, _req->length, _req->buf,
		(unsigned long long) _req->dma, _req->zero ? "zero" : "!zero");

	spin_lock_irqsave(&dev->lock, flags);

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

	/* kickstart this i/o queue? */
	if (list_empty(&ep->queue) && !ep->stopped) {
		/* maybe there's no control data, just status ack */
		if (ep->num == 0 && _req->length == 0) {
			net2272_done(ep, req, 0);
			dev_vdbg(dev->dev, "%s status ack\n", ep->ep.name);
			goto done;
		}

		/* Return zlp, don't let it block subsequent packets */
		s = net2272_ep_read(ep, EP_STAT0);
		if (s & (1 << BUFFER_EMPTY)) {
			/* Buffer is empty check for a blocking zlp, handle it */
			if ((s & (1 << NAK_OUT_PACKETS)) &&
			    net2272_ep_read(ep, EP_STAT1) & (1 << LOCAL_OUT_ZLP)) {
				dev_dbg(dev->dev, "WARNING: returning ZLP short packet termination!\n");
				/*
				 * Request is going to terminate with a short packet ...
				 * hope the client is ready for it!
				 */
				status = net2272_read_fifo(ep, req);
				/* clear short packet naking */
				net2272_ep_write(ep, EP_STAT0, (1 << NAK_OUT_PACKETS));
				goto done;
			}
		}

		/* try dma first */
		status = net2272_kick_dma(ep, req);

		if (status < 0) {
			/* dma failed (most likely in use by another endpoint)
			 * fallback to pio
			 */
			status = 0;

			if (ep->is_in)
				status = net2272_write_fifo(ep, req);
			else {
				s = net2272_ep_read(ep, EP_STAT0);
				if ((s & (1 << BUFFER_EMPTY)) == 0)
					status = net2272_read_fifo(ep, req);
			}

			if (unlikely(status != 0)) {
				if (status > 0)
					status = 0;
				req = NULL;
			}
		}
	}
	if (likely(req))
		list_add_tail(&req->queue, &ep->queue);

	if (likely(!list_empty(&ep->queue)))
		net2272_ep_write(ep, EP_RSPCLR, 1 << ALT_NAK_OUT_PACKETS);
 done:
	spin_unlock_irqrestore(&dev->lock, flags);

	return 0;
}

/* dequeue ALL requests */
static void
net2272_dequeue_all(struct net2272_ep *ep)
{
	struct net2272_request *req;

	/* called with spinlock held */
	ep->stopped = 1;

	while (!list_empty(&ep->queue)) {
		req = list_entry(ep->queue.next,
				struct net2272_request,
				queue);
		net2272_done(ep, req, -ESHUTDOWN);
	}
}

/* dequeue JUST ONE request */
static int
net2272_dequeue(struct usb_ep *_ep, struct usb_request *_req)
{
	struct net2272_ep *ep;
	struct net2272_request *req;
	unsigned long flags;
	int stopped;

	ep = container_of(_ep, struct net2272_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0) || !_req)
		return -EINVAL;

	spin_lock_irqsave(&ep->dev->lock, flags);
	stopped = ep->stopped;
	ep->stopped = 1;

	/* 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) {
		ep->stopped = stopped;
		spin_unlock_irqrestore(&ep->dev->lock, flags);
		return -EINVAL;
	}

	/* queue head may be partially complete */
	if (ep->queue.next == &req->queue) {
		dev_dbg(ep->dev->dev, "unlink (%s) pio\n", _ep->name);
		net2272_done(ep, req, -ECONNRESET);
	}
	req = NULL;
	ep->stopped = stopped;

	spin_unlock_irqrestore(&ep->dev->lock, flags);
	return 0;
}

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

static int
net2272_set_halt_and_wedge(struct usb_ep *_ep, int value, int wedged)
{
	struct net2272_ep *ep;
	unsigned long flags;
	int ret = 0;

	ep = container_of(_ep, struct net2272_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0))
		return -EINVAL;
	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;
	if (ep->desc /* not ep0 */ && usb_endpoint_xfer_isoc(ep->desc))
		return -EINVAL;

	spin_lock_irqsave(&ep->dev->lock, flags);
	if (!list_empty(&ep->queue))
		ret = -EAGAIN;
	else if (ep->is_in && value && net2272_fifo_status(_ep) != 0)
		ret = -EAGAIN;
	else {
		dev_vdbg(ep->dev->dev, "%s %s %s\n", _ep->name,
			value ? "set" : "clear",
			wedged ? "wedge" : "halt");
		/* set/clear */
		if (value) {
			if (ep->num == 0)
				ep->dev->protocol_stall = 1;
			else
				set_halt(ep);
			if (wedged)
				ep->wedged = 1;
		} else {
			clear_halt(ep);
			ep->wedged = 0;
		}
	}
	spin_unlock_irqrestore(&ep->dev->lock, flags);

	return ret;
}

static int
net2272_set_halt(struct usb_ep *_ep, int value)
{
	return net2272_set_halt_and_wedge(_ep, value, 0);
}

static int
net2272_set_wedge(struct usb_ep *_ep)
{
	if (!_ep || _ep->name == ep0name)
		return -EINVAL;
	return net2272_set_halt_and_wedge(_ep, 1, 1);
}

static int
net2272_fifo_status(struct usb_ep *_ep)
{
	struct net2272_ep *ep;
	u16 avail;

	ep = container_of(_ep, struct net2272_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0))
		return -ENODEV;
	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
		return -ESHUTDOWN;

	avail = net2272_ep_read(ep, EP_AVAIL1) << 8;
	avail |= net2272_ep_read(ep, EP_AVAIL0);
	if (avail > ep->fifo_size)
		return -EOVERFLOW;
	if (ep->is_in)
		avail = ep->fifo_size - avail;
	return avail;
}

static void
net2272_fifo_flush(struct usb_ep *_ep)
{
	struct net2272_ep *ep;

	ep = container_of(_ep, struct net2272_ep, ep);
	if (!_ep || (!ep->desc && ep->num != 0))
		return;
	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
		return;

	net2272_ep_write(ep, EP_STAT1, 1 << BUFFER_FLUSH);
}

static const struct usb_ep_ops net2272_ep_ops = {
	.enable        = net2272_enable,
	.disable       = net2272_disable,

	.alloc_request = net2272_alloc_request,
	.free_request  = net2272_free_request,

	.queue         = net2272_queue,
	.dequeue       = net2272_dequeue,

	.set_halt      = net2272_set_halt,
	.set_wedge     = net2272_set_wedge,
	.fifo_status   = net2272_fifo_status,
	.fifo_flush    = net2272_fifo_flush,
};

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

static int
net2272_get_frame(struct usb_gadget *_gadget)
{
	struct net2272 *dev;
	unsigned long flags;
	u16 ret;

	if (!_gadget)
		return -ENODEV;
	dev = container_of(_gadget, struct net2272, gadget);
	spin_lock_irqsave(&dev->lock, flags);

	ret = net2272_read(dev, FRAME1) << 8;
	ret |= net2272_read(dev, FRAME0);

	spin_unlock_irqrestore(&dev->lock, flags);
	return ret;
}

static int
net2272_wakeup(struct usb_gadget *_gadget)
{
	struct net2272 *dev;
	u8 tmp;
	unsigned long flags;

	if (!_gadget)
		return 0;
	dev = container_of(_gadget, struct net2272, gadget);

	spin_lock_irqsave(&dev->lock, flags);
	tmp = net2272_read(dev, USBCTL0);
	if (tmp & (1 << IO_WAKEUP_ENABLE))
		net2272_write(dev, USBCTL1, (1 << GENERATE_RESUME));

	spin_unlock_irqrestore(&dev->lock, flags);

	return 0;
}

static int
net2272_set_selfpowered(struct usb_gadget *_gadget, int value)
{
	if (!_gadget)
		return -ENODEV;

	_gadget->is_selfpowered = (value != 0);

	return 0;
}

static int
net2272_pullup(struct usb_gadget *_gadget, int is_on)
{
	struct net2272 *dev;
	u8 tmp;
	unsigned long flags;

	if (!_gadget)
		return -ENODEV;
	dev = container_of(_gadget, struct net2272, gadget);

	spin_lock_irqsave(&dev->lock, flags);
	tmp = net2272_read(dev, USBCTL0);
	dev->softconnect = (is_on != 0);
	if (is_on)
		tmp |= (1 << USB_DETECT_ENABLE);
	else
		tmp &= ~(1 << USB_DETECT_ENABLE);
	net2272_write(dev, USBCTL0, tmp);
	spin_unlock_irqrestore(&dev->lock, flags);

	return 0;
}

static int net2272_start(struct usb_gadget *_gadget,
		struct usb_gadget_driver *driver);
static int net2272_stop(struct usb_gadget *_gadget);

static const struct usb_gadget_ops net2272_ops = {
	.get_frame	= net2272_get_frame,
	.wakeup		= net2272_wakeup,
	.set_selfpowered = net2272_set_selfpowered,
	.pullup		= net2272_pullup,
	.udc_start	= net2272_start,
	.udc_stop	= net2272_stop,
};

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

static ssize_t
registers_show(struct device *_dev, struct device_attribute *attr, char *buf)
{
	struct net2272 *dev;
	char *next;
	unsigned size, t;
	unsigned long flags;
	u8 t1, t2;
	int i;
	const char *s;

	dev = dev_get_drvdata(_dev);
	next = buf;
	size = PAGE_SIZE;
	spin_lock_irqsave(&dev->lock, flags);

	/* Main Control Registers */
	t = scnprintf(next, size, "%s version %s,"
		"chiprev %02x, locctl %02x\n"
		"irqenb0 %02x irqenb1 %02x "
		"irqstat0 %02x irqstat1 %02x\n",
		driver_name, driver_vers, dev->chiprev,
		net2272_read(dev, LOCCTL),
		net2272_read(dev, IRQENB0),
		net2272_read(dev, IRQENB1),
		net2272_read(dev, IRQSTAT0),
		net2272_read(dev, IRQSTAT1));
	size -= t;
	next += t;

	/* DMA */
	t1 = net2272_read(dev, DMAREQ);
	t = scnprintf(next, size, "\ndmareq %02x: %s %s%s%s%s\n",
		t1, ep_name[(t1 & 0x01) + 1],
		t1 & (1 << DMA_CONTROL_DACK) ? "dack " : "",
		t1 & (1 << DMA_REQUEST_ENABLE) ? "reqenb " : "",
		t1 & (1 << DMA_REQUEST) ? "req " : "",
		t1 & (1 << DMA_BUFFER_VALID) ? "valid " : "");
	size -= t;
	next += t;

	/* USB Control Registers */
	t1 = net2272_read(dev, USBCTL1);
	if (t1 & (1 << VBUS_PIN)) {
		if (t1 & (1 << USB_HIGH_SPEED))
			s = "high speed";
		else if (dev->gadget.speed == USB_SPEED_UNKNOWN)
			s = "powered";
		else
			s = "full speed";
	} else
		s = "not attached";
	t = scnprintf(next, size,
		"usbctl0 %02x usbctl1 %02x addr 0x%02x (%s)\n",
		net2272_read(dev, USBCTL0), t1,
		net2272_read(dev, OURADDR), s);
	size -= t;
	next += t;

	/* Endpoint Registers */
	for (i = 0; i < 4; ++i) {
		struct net2272_ep *ep;

		ep = &dev->ep[i];
		if (i && !ep->desc)
			continue;

		t1 = net2272_ep_read(ep, EP_CFG);
		t2 = net2272_ep_read(ep, EP_RSPSET);
		t = scnprintf(next, size,
			"\n%s\tcfg %02x rsp (%02x) %s%s%s%s%s%s%s%s"
			"irqenb %02x\n",
			ep->ep.name, t1, t2,
			(t2 & (1 << ALT_NAK_OUT_PACKETS)) ? "NAK " : "",
			(t2 & (1 << HIDE_STATUS_PHASE)) ? "hide " : "",
			(t2 & (1 << AUTOVALIDATE)) ? "auto " : "",
			(t2 & (1 << INTERRUPT_MODE)) ? "interrupt " : "",
			(t2 & (1 << CONTROL_STATUS_PHASE_HANDSHAKE)) ? "status " : "",
			(t2 & (1 << NAK_OUT_PACKETS_MODE)) ? "NAKmode " : "",
			(t2 & (1 << ENDPOINT_TOGGLE)) ? "DATA1 " : "DATA0 ",
			(t2 & (1 << ENDPOINT_HALT)) ? "HALT " : "",
			net2272_ep_read(ep, EP_IRQENB));
		size -= t;
		next += t;

		t = scnprintf(next, size,
			"\tstat0 %02x stat1 %02x avail %04x "
			"(ep%d%s-%s)%s\n",
			net2272_ep_read(ep, EP_STAT0),
			net2272_ep_read(ep, EP_STAT1),
			(net2272_ep_read(ep, EP_AVAIL1) << 8) | net2272_ep_read(ep, EP_AVAIL0),
			t1 & 0x0f,
			ep->is_in ? "in" : "out",
			type_string(t1 >> 5),
			ep->stopped ? "*" : "");
		size -= t;
		next += t;

		t = scnprintf(next, size,
			"\tep_transfer %06x\n",
			((net2272_ep_read(ep, EP_TRANSFER2) & 0xff) << 16) |
			((net2272_ep_read(ep, EP_TRANSFER1) & 0xff) << 8) |
			((net2272_ep_read(ep, EP_TRANSFER0) & 0xff)));
		size -= t;
		next += t;

		t1 = net2272_ep_read(ep, EP_BUFF_STATES) & 0x03;
		t2 = (net2272_ep_read(ep, EP_BUFF_STATES) >> 2) & 0x03;
		t = scnprintf(next, size,
			"\tbuf-a %s buf-b %s\n",
			buf_state_string(t1),
			buf_state_string(t2));
		size -= t;
		next += t;
	}

	spin_unlock_irqrestore(&dev->lock, flags);

	return PAGE_SIZE - size;
}
static DEVICE_ATTR_RO(registers);

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

static void
net2272_set_fifo_mode(struct net2272 *dev, int mode)
{
	u8 tmp;

	tmp = net2272_read(dev, LOCCTL) & 0x3f;
	tmp |= (mode << 6);
	net2272_write(dev, LOCCTL, tmp);

	INIT_LIST_HEAD(&dev->gadget.ep_list);

	/* always ep-a, ep-c ... maybe not ep-b */
	list_add_tail(&dev->ep[1].ep.ep_list, &dev->gadget.ep_list);

	switch (mode) {
	case 0:
		list_add_tail(&dev->ep[2].ep.ep_list, &dev->gadget.ep_list);
		dev->ep[1].fifo_size = dev->ep[2].fifo_size = 512;
		break;
	case 1:
		list_add_tail(&dev->ep[2].ep.ep_list, &dev->gadget.ep_list);
		dev->ep[1].fifo_size = 1024;
		dev->ep[2].fifo_size = 512;
		break;
	case 2:
		list_add_tail(&dev->ep[2].ep.ep_list, &dev->gadget.ep_list);
		dev->ep[1].fifo_size = dev->ep[2].fifo_size = 1024;
		break;
	case 3:
		dev->ep[1].fifo_size = 1024;
		break;
	}

	/* ep-c is always 2 512 byte buffers */
	list_add_tail(&dev->ep[3].ep.ep_list, &dev->gadget.ep_list);
	dev->ep[3].fifo_size = 512;
}

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

static void
net2272_usb_reset(struct net2272 *dev)
{
	dev->gadget.speed = USB_SPEED_UNKNOWN;

	net2272_cancel_dma(dev);

	net2272_write(dev, IRQENB0, 0);
	net2272_write(dev, IRQENB1, 0);

	/* clear irq state */
	net2272_write(dev, IRQSTAT0, 0xff);
	net2272_write(dev, IRQSTAT1, ~(1 << SUSPEND_REQUEST_INTERRUPT));

	net2272_write(dev, DMAREQ,
		(0 << DMA_BUFFER_VALID) |
		(0 << DMA_REQUEST_ENABLE) |
		(1 << DMA_CONTROL_DACK) |
		(dev->dma_eot_polarity << EOT_POLARITY) |
		(dev->dma_dack_polarity << DACK_POLARITY) |
		(dev->dma_dreq_polarity << DREQ_POLARITY) |
		((dma_ep >> 1) << DMA_ENDPOINT_SELECT));

	net2272_cancel_dma(dev);
	net2272_set_fifo_mode(dev, (fifo_mode <= 3) ? fifo_mode : 0);

	/* Set the NET2272 ep fifo data width to 16-bit mode and for correct byte swapping
	 * note that the higher level gadget drivers are expected to convert data to little endian.
	 * Enable byte swap for your local bus/cpu if needed by setting BYTE_SWAP in LOCCTL here
	 */
	net2272_write(dev, LOCCTL, net2272_read(dev, LOCCTL) | (1 << DATA_WIDTH));
	net2272_write(dev, LOCCTL1, (dma_mode << DMA_MODE));
}

static void
net2272_usb_reinit(struct net2272 *dev)
{
	int i;

	/* basic endpoint init */
	for (i = 0; i < 4; ++i) {
		struct net2272_ep *ep = &dev->ep[i];

		ep->ep.name = ep_name[i];
		ep->dev = dev;
		ep->num = i;
		ep->not_empty = 0;

		if (use_dma && ep->num == dma_ep)
			ep->dma = 1;

		if (i > 0 && i <= 3)
			ep->fifo_size = 512;
		else
			ep->fifo_size = 64;
		net2272_ep_reset(ep);

		if (i == 0) {
			ep->ep.caps.type_control = true;
		} else {
			ep->ep.caps.type_iso = true;
			ep->ep.caps.type_bulk = true;
			ep->ep.caps.type_int = true;
		}

		ep->ep.caps.dir_in = true;
		ep->ep.caps.dir_out = true;
	}
	usb_ep_set_maxpacket_limit(&dev->ep[0].ep, 64);

	dev->gadget.ep0 = &dev->ep[0].ep;
	dev->ep[0].stopped = 0;
	INIT_LIST_HEAD(&dev->gadget.ep0->ep_list);
}

static void
net2272_ep0_start(struct net2272 *dev)
{
	struct net2272_ep *ep0 = &dev->ep[0];

	net2272_ep_write(ep0, EP_RSPSET,
		(1 << NAK_OUT_PACKETS_MODE) |
		(1 << ALT_NAK_OUT_PACKETS));
	net2272_ep_write(ep0, EP_RSPCLR,
		(1 << HIDE_STATUS_PHASE) |
		(1 << CONTROL_STATUS_PHASE_HANDSHAKE));
	net2272_write(dev, USBCTL0,
		(dev->softconnect << USB_DETECT_ENABLE) |
		(1 << USB_ROOT_PORT_WAKEUP_ENABLE) |
		(1 << IO_WAKEUP_ENABLE));
	net2272_write(dev, IRQENB0,
		(1 << SETUP_PACKET_INTERRUPT_ENABLE) |
		(1 << ENDPOINT_0_INTERRUPT_ENABLE) |
		(1 << DMA_DONE_INTERRUPT_ENABLE));
	net2272_write(dev, IRQENB1,
		(1 << VBUS_INTERRUPT_ENABLE) |
		(1 << ROOT_PORT_RESET_INTERRUPT_ENABLE) |
		(1 << SUSPEND_REQUEST_CHANGE_INTERRUPT_ENABLE));
}

/* 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.
 */
static int net2272_start(struct usb_gadget *_gadget,
		struct usb_gadget_driver *driver)
{
	struct net2272 *dev;
	unsigned i;

	if (!driver || !driver->setup ||
	    driver->max_speed != USB_SPEED_HIGH)
		return -EINVAL;

	dev = container_of(_gadget, struct net2272, gadget);

	for (i = 0; i < 4; ++i)
		dev->ep[i].irqs = 0;
	/* hook up the driver ... */
	dev->softconnect = 1;
	driver->driver.bus = NULL;
	dev->driver = driver;

	/* ... then enable host detection and ep0; and we're ready
	 * for set_configuration as well as eventual disconnect.
	 */
	net2272_ep0_start(dev);

	return 0;
}

static void
stop_activity(struct net2272 *dev, struct usb_gadget_driver *driver)
{
	int i;

	/* don't disconnect if it's not connected */
	if (dev->gadget.speed == USB_SPEED_UNKNOWN)
		driver = NULL;

	/* stop hardware; prevent new request submissions;
	 * and kill any outstanding requests.
	 */
	net2272_usb_reset(dev);
	for (i = 0; i < 4; ++i)
		net2272_dequeue_all(&dev->ep[i]);

	/* report disconnect; the driver is already quiesced */
	if (driver) {
		spin_unlock(&dev->lock);
		driver->disconnect(&dev->gadget);
		spin_lock(&dev->lock);
	}

	net2272_usb_reinit(dev);
}

static int net2272_stop(struct usb_gadget *_gadget)
{
	struct net2272 *dev;
	unsigned long flags;

	dev = container_of(_gadget, struct net2272, gadget);

	spin_lock_irqsave(&dev->lock, flags);
	stop_activity(dev, NULL);
	spin_unlock_irqrestore(&dev->lock, flags);

	dev->driver = NULL;

	return 0;
}

/*---------------------------------------------------------------------------*/
/* handle ep-a/ep-b dma completions */
static void
net2272_handle_dma(struct net2272_ep *ep)
{
	struct net2272_request *req;
	unsigned len;
	int status;

	if (!list_empty(&ep->queue))
		req = list_entry(ep->queue.next,
				struct net2272_request, queue);
	else
		req = NULL;

	dev_vdbg(ep->dev->dev, "handle_dma %s req %p\n", ep->ep.name, req);

	/* Ensure DREQ is de-asserted */
	net2272_write(ep->dev, DMAREQ,
		(0 << DMA_BUFFER_VALID)
	      | (0 << DMA_REQUEST_ENABLE)
	      | (1 << DMA_CONTROL_DACK)
	      | (ep->dev->dma_eot_polarity << EOT_POLARITY)
	      | (ep->dev->dma_dack_polarity << DACK_POLARITY)
	      | (ep->dev->dma_dreq_polarity << DREQ_POLARITY)
	      | (ep->dma << DMA_ENDPOINT_SELECT));

	ep->dev->dma_busy = 0;

	net2272_ep_write(ep, EP_IRQENB,
		  (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
		| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE)
		| net2272_ep_read(ep, EP_IRQENB));

	/* device-to-host transfer completed */
	if (ep->is_in) {
		/* validate a short packet or zlp if necessary */
		if ((req->req.length % ep->ep.maxpacket != 0) ||
				req->req.zero)
			set_fifo_bytecount(ep, 0);

		net2272_done(ep, req, 0);
		if (!list_empty(&ep->queue)) {
			req = list_entry(ep->queue.next,
					struct net2272_request, queue);
			status = net2272_kick_dma(ep, req);
			if (status < 0)
				net2272_pio_advance(ep);
		}

	/* host-to-device transfer completed */
	} else {
		/* terminated with a short packet? */
		if (net2272_read(ep->dev, IRQSTAT0) &
				(1 << DMA_DONE_INTERRUPT)) {
			/* abort system dma */
			net2272_cancel_dma(ep->dev);
		}

		/* EP_TRANSFER will contain the number of bytes
		 * actually received.
		 * NOTE: There is no overflow detection on EP_TRANSFER:
		 * We can't deal with transfers larger than 2^24 bytes!
		 */
		len = (net2272_ep_read(ep, EP_TRANSFER2) << 16)
			| (net2272_ep_read(ep, EP_TRANSFER1) << 8)
			| (net2272_ep_read(ep, EP_TRANSFER0));

		if (ep->not_empty)
			len += 4;

		req->req.actual += len;

		/* get any remaining data */
		net2272_pio_advance(ep);
	}
}

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

static void
net2272_handle_ep(struct net2272_ep *ep)
{
	struct net2272_request *req;
	u8 stat0, stat1;

	if (!list_empty(&ep->queue))
		req = list_entry(ep->queue.next,
			struct net2272_request, queue);
	else
		req = NULL;

	/* ack all, and handle what we care about */
	stat0 = net2272_ep_read(ep, EP_STAT0);
	stat1 = net2272_ep_read(ep, EP_STAT1);
	ep->irqs++;

	dev_vdbg(ep->dev->dev, "%s ack ep_stat0 %02x, ep_stat1 %02x, req %p\n",
		ep->ep.name, stat0, stat1, req ? &req->req : NULL);

	net2272_ep_write(ep, EP_STAT0, stat0 &
		~((1 << NAK_OUT_PACKETS)
		| (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)));
	net2272_ep_write(ep, EP_STAT1, stat1);

	/* data packet(s) received (in the fifo, OUT)
	 * direction must be validated, otherwise control read status phase
	 * could be interpreted as a valid packet
	 */
	if (!ep->is_in && (stat0 & (1 << DATA_PACKET_RECEIVED_INTERRUPT)))
		net2272_pio_advance(ep);
	/* data packet(s) transmitted (IN) */
	else if (stat0 & (1 << DATA_PACKET_TRANSMITTED_INTERRUPT))
		net2272_pio_advance(ep);
}

static struct net2272_ep *
net2272_get_ep_by_addr(struct net2272 *dev, u16 wIndex)
{
	struct net2272_ep *ep;

	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 & 0x0f) == (bEndpointAddress & 0x0f))
			return ep;
	}
	return NULL;
}

/*
 * USB Test Packet:
 * JKJKJKJK * 9
 * JJKKJJKK * 8
 * JJJJKKKK * 8
 * JJJJJJJKKKKKKK * 8
 * JJJJJJJK * 8
 * {JKKKKKKK * 10}, JK
 */
static const u8 net2272_test_packet[] = {
	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
	0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE, 0xEE,
	0xFE, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
	0x7F, 0xBF, 0xDF, 0xEF, 0xF7, 0xFB, 0xFD,
	0xFC, 0x7E, 0xBF, 0xDF, 0xEF, 0xF7, 0xFD, 0x7E
};

static void
net2272_set_test_mode(struct net2272 *dev, int mode)
{
	int i;

	/* Disable all net2272 interrupts:
	 * Nothing but a power cycle should stop the test.
	 */
	net2272_write(dev, IRQENB0, 0x00);
	net2272_write(dev, IRQENB1, 0x00);

	/* Force tranceiver to high-speed */
	net2272_write(dev, XCVRDIAG, 1 << FORCE_HIGH_SPEED);

	net2272_write(dev, PAGESEL, 0);
	net2272_write(dev, EP_STAT0, 1 << DATA_PACKET_TRANSMITTED_INTERRUPT);
	net2272_write(dev, EP_RSPCLR,
			  (1 << CONTROL_STATUS_PHASE_HANDSHAKE)
			| (1 << HIDE_STATUS_PHASE));
	net2272_write(dev, EP_CFG, 1 << ENDPOINT_DIRECTION);
	net2272_write(dev, EP_STAT1, 1 << BUFFER_FLUSH);

	/* wait for status phase to complete */
	while (!(net2272_read(dev, EP_STAT0) &
				(1 << DATA_PACKET_TRANSMITTED_INTERRUPT)))
		;

	/* Enable test mode */
	net2272_write(dev, USBTEST, mode);

	/* load test packet */
	if (mode == TEST_PACKET) {
		/* switch to 8 bit mode */
		net2272_write(dev, LOCCTL, net2272_read(dev, LOCCTL) &
				~(1 << DATA_WIDTH));

		for (i = 0; i < sizeof(net2272_test_packet); ++i)
			net2272_write(dev, EP_DATA, net2272_test_packet[i]);

		/* Validate test packet */
		net2272_write(dev, EP_TRANSFER0, 0);
	}
}

static void
net2272_handle_stat0_irqs(struct net2272 *dev, u8 stat)
{
	struct net2272_ep *ep;
	u8 num, scratch;

	/* starting a control request? */
	if (unlikely(stat & (1 << SETUP_PACKET_INTERRUPT))) {
		union {
			u8 raw[8];
			struct usb_ctrlrequest	r;
		} u;
		int tmp = 0;
		struct net2272_request *req;

		if (dev->gadget.speed == USB_SPEED_UNKNOWN) {
			if (net2272_read(dev, USBCTL1) & (1 << USB_HIGH_SPEED))
				dev->gadget.speed = USB_SPEED_HIGH;
			else
				dev->gadget.speed = USB_SPEED_FULL;
			dev_dbg(dev->dev, "%s\n",
				usb_speed_string(dev->gadget.speed));
		}

		ep = &dev->ep[0];
		ep->irqs++;

		/* make sure any leftover interrupt state is cleared */
		stat &= ~(1 << ENDPOINT_0_INTERRUPT);
		while (!list_empty(&ep->queue)) {
			req = list_entry(ep->queue.next,
				struct net2272_request, queue);
			net2272_done(ep, req,
				(req->req.actual == req->req.length) ? 0 : -EPROTO);
		}
		ep->stopped = 0;
		dev->protocol_stall = 0;
		net2272_ep_write(ep, EP_STAT0,
			    (1 << DATA_IN_TOKEN_INTERRUPT)
			  | (1 << DATA_OUT_TOKEN_INTERRUPT)
			  | (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
			  | (1 << DATA_PACKET_RECEIVED_INTERRUPT)
			  | (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT));
		net2272_ep_write(ep, EP_STAT1,
			    (1 << TIMEOUT)
			  | (1 << USB_OUT_ACK_SENT)
			  | (1 << USB_OUT_NAK_SENT)
			  | (1 << USB_IN_ACK_RCVD)
			  | (1 << USB_IN_NAK_SENT)
			  | (1 << USB_STALL_SENT)
			  | (1 << LOCAL_OUT_ZLP));

		/*
		 * Ensure Control Read pre-validation setting is beyond maximum size
		 *  - Control Writes can leave non-zero values in EP_TRANSFER. If
		 *    an EP0 transfer following the Control Write is a Control Read,
		 *    the NET2272 sees the non-zero EP_TRANSFER as an unexpected
		 *    pre-validation count.
		 *  - Setting EP_TRANSFER beyond the maximum EP0 transfer size ensures
		 *    the pre-validation count cannot cause an unexpected validatation
		 */
		net2272_write(dev, PAGESEL, 0);
		net2272_write(dev, EP_TRANSFER2, 0xff);
		net2272_write(dev, EP_TRANSFER1, 0xff);
		net2272_write(dev, EP_TRANSFER0, 0xff);

		u.raw[0] = net2272_read(dev, SETUP0);
		u.raw[1] = net2272_read(dev, SETUP1);
		u.raw[2] = net2272_read(dev, SETUP2);
		u.raw[3] = net2272_read(dev, SETUP3);
		u.raw[4] = net2272_read(dev, SETUP4);
		u.raw[5] = net2272_read(dev, SETUP5);
		u.raw[6] = net2272_read(dev, SETUP6);
		u.raw[7] = net2272_read(dev, SETUP7);
		/*
		 * If you have a big endian cpu make sure le16_to_cpus
		 * performs the proper byte swapping here...
		 */
		le16_to_cpus(&u.r.wValue);
		le16_to_cpus(&u.r.wIndex);
		le16_to_cpus(&u.r.wLength);

		/* ack the irq */
		net2272_write(dev, IRQSTAT0, 1 << SETUP_PACKET_INTERRUPT);
		stat ^= (1 << SETUP_PACKET_INTERRUPT);

		/* watch control traffic at the token level, and force
		 * synchronization before letting the status phase happen.
		 */
		ep->is_in = (u.r.bRequestType & USB_DIR_IN) != 0;
		if (ep->is_in) {
			scratch = (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE)
				| (1 << DATA_OUT_TOKEN_INTERRUPT_ENABLE)
				| (1 << DATA_IN_TOKEN_INTERRUPT_ENABLE);
			stop_out_naking(ep);
		} else
			scratch = (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
				| (1 << DATA_OUT_TOKEN_INTERRUPT_ENABLE)
				| (1 << DATA_IN_TOKEN_INTERRUPT_ENABLE);
		net2272_ep_write(ep, EP_IRQENB, scratch);

		if ((u.r.bRequestType & USB_TYPE_MASK) != USB_TYPE_STANDARD)
			goto delegate;
		switch (u.r.bRequest) {
		case USB_REQ_GET_STATUS: {
			struct net2272_ep *e;
			u16 status = 0;

			switch (u.r.bRequestType & USB_RECIP_MASK) {
			case USB_RECIP_ENDPOINT:
				e = net2272_get_ep_by_addr(dev, u.r.wIndex);
				if (!e || u.r.wLength > 2)
					goto do_stall;
				if (net2272_ep_read(e, EP_RSPSET) & (1 << ENDPOINT_HALT))
					status = cpu_to_le16(1);
				else
					status = cpu_to_le16(0);

				/* don't bother with a request object! */
				net2272_ep_write(&dev->ep[0], EP_IRQENB, 0);
				writew(status, net2272_reg_addr(dev, EP_DATA));
				set_fifo_bytecount(&dev->ep[0], 0);
				allow_status(ep);
				dev_vdbg(dev->dev, "%s stat %02x\n",
					ep->ep.name, status);
				goto next_endpoints;
			case USB_RECIP_DEVICE:
				if (u.r.wLength > 2)
					goto do_stall;
				if (dev->gadget.is_selfpowered)
					status = (1 << USB_DEVICE_SELF_POWERED);

				/* don't bother with a request object! */
				net2272_ep_write(&dev->ep[0], EP_IRQENB, 0);
				writew(status, net2272_reg_addr(dev, EP_DATA));
				set_fifo_bytecount(&dev->ep[0], 0);
				allow_status(ep);
				dev_vdbg(dev->dev, "device stat %02x\n", status);
				goto next_endpoints;
			case USB_RECIP_INTERFACE:
				if (u.r.wLength > 2)
					goto do_stall;

				/* don't bother with a request object! */
				net2272_ep_write(&dev->ep[0], EP_IRQENB, 0);
				writew(status, net2272_reg_addr(dev, EP_DATA));
				set_fifo_bytecount(&dev->ep[0], 0);
				allow_status(ep);
				dev_vdbg(dev->dev, "interface status %02x\n", status);
				goto next_endpoints;
			}

			break;
		}
		case USB_REQ_CLEAR_FEATURE: {
			struct net2272_ep *e;

			if (u.r.bRequestType != USB_RECIP_ENDPOINT)
				goto delegate;
			if (u.r.wValue != USB_ENDPOINT_HALT ||
			    u.r.wLength != 0)
				goto do_stall;
			e = net2272_get_ep_by_addr(dev, u.r.wIndex);
			if (!e)
				goto do_stall;
			if (e->wedged) {
				dev_vdbg(dev->dev, "%s wedged, halt not cleared\n",
					ep->ep.name);
			} else {
				dev_vdbg(dev->dev, "%s clear halt\n", ep->ep.name);
				clear_halt(e);
			}
			allow_status(ep);
			goto next_endpoints;
		}
		case USB_REQ_SET_FEATURE: {
			struct net2272_ep *e;

			if (u.r.bRequestType == USB_RECIP_DEVICE) {
				if (u.r.wIndex != NORMAL_OPERATION)
					net2272_set_test_mode(dev, (u.r.wIndex >> 8));
				allow_status(ep);
				dev_vdbg(dev->dev, "test mode: %d\n", u.r.wIndex);
				goto next_endpoints;
			} else if (u.r.bRequestType != USB_RECIP_ENDPOINT)
				goto delegate;
			if (u.r.wValue != USB_ENDPOINT_HALT ||
			    u.r.wLength != 0)
				goto do_stall;
			e = net2272_get_ep_by_addr(dev, u.r.wIndex);
			if (!e)
				goto do_stall;
			set_halt(e);
			allow_status(ep);
			dev_vdbg(dev->dev, "%s set halt\n", ep->ep.name);
			goto next_endpoints;
		}
		case USB_REQ_SET_ADDRESS: {
			net2272_write(dev, OURADDR, u.r.wValue & 0xff);
			allow_status(ep);
			break;
		}
		default:
 delegate:
			dev_vdbg(dev->dev, "setup %02x.%02x v%04x i%04x "
				"ep_cfg %08x\n",
				u.r.bRequestType, u.r.bRequest,
				u.r.wValue, u.r.wIndex,
				net2272_ep_read(ep, EP_CFG));
			spin_unlock(&dev->lock);
			tmp = dev->driver->setup(&dev->gadget, &u.r);
			spin_lock(&dev->lock);
		}

		/* stall ep0 on error */
		if (tmp < 0) {
 do_stall:
			dev_vdbg(dev->dev, "req %02x.%02x protocol STALL; stat %d\n",
				u.r.bRequestType, u.r.bRequest, tmp);
			dev->protocol_stall = 1;
		}
	/* endpoint dma irq? */
	} else if (stat & (1 << DMA_DONE_INTERRUPT)) {
		net2272_cancel_dma(dev);
		net2272_write(dev, IRQSTAT0, 1 << DMA_DONE_INTERRUPT);
		stat &= ~(1 << DMA_DONE_INTERRUPT);
		num = (net2272_read(dev, DMAREQ) & (1 << DMA_ENDPOINT_SELECT))
			? 2 : 1;

		ep = &dev->ep[num];
		net2272_handle_dma(ep);
	}

 next_endpoints:
	/* endpoint data irq? */
	scratch = stat & 0x0f;
	stat &= ~0x0f;
	for (num = 0; scratch; num++) {
		u8 t;

		/* does this endpoint's FIFO and queue need tending? */
		t = 1 << num;
		if ((scratch & t) == 0)
			continue;
		scratch ^= t;

		ep = &dev->ep[num];
		net2272_handle_ep(ep);
	}

	/* some interrupts we can just ignore */
	stat &= ~(1 << SOF_INTERRUPT);

	if (stat)
		dev_dbg(dev->dev, "unhandled irqstat0 %02x\n", stat);
}

static void
net2272_handle_stat1_irqs(struct net2272 *dev, u8 stat)
{
	u8 tmp, mask;

	/* after disconnect there's nothing else to do! */
	tmp = (1 << VBUS_INTERRUPT) | (1 << ROOT_PORT_RESET_INTERRUPT);
	mask = (1 << USB_HIGH_SPEED) | (1 << USB_FULL_SPEED);

	if (stat & tmp) {
		bool	reset = false;
		bool	disconnect = false;

		/*
		 * Ignore disconnects and resets if the speed hasn't been set.
		 * VBUS can bounce and there's always an initial reset.
		 */
		net2272_write(dev, IRQSTAT1, tmp);
		if (dev->gadget.speed != USB_SPEED_UNKNOWN) {
			if ((stat & (1 << VBUS_INTERRUPT)) &&
					(net2272_read(dev, USBCTL1) &
						(1 << VBUS_PIN)) == 0) {
				disconnect = true;
				dev_dbg(dev->dev, "disconnect %s\n",
					dev->driver->driver.name);
			} else if ((stat & (1 << ROOT_PORT_RESET_INTERRUPT)) &&
					(net2272_read(dev, USBCTL1) & mask)
						== 0) {
				reset = true;
				dev_dbg(dev->dev, "reset %s\n",
					dev->driver->driver.name);
			}

			if (disconnect || reset) {
				stop_activity(dev, dev->driver);
				net2272_ep0_start(dev);
				spin_unlock(&dev->lock);
				if (reset)
					usb_gadget_udc_reset
						(&dev->gadget, dev->driver);
				else
					(dev->driver->disconnect)
						(&dev->gadget);
				spin_lock(&dev->lock);
				return;
			}
		}
		stat &= ~tmp;

		if (!stat)
			return;
	}

	tmp = (1 << SUSPEND_REQUEST_CHANGE_INTERRUPT);
	if (stat & tmp) {
		net2272_write(dev, IRQSTAT1, tmp);
		if (stat & (1 << SUSPEND_REQUEST_INTERRUPT)) {
			if (dev->driver->suspend)
				dev->driver->suspend(&dev->gadget);
			if (!enable_suspend) {
				stat &= ~(1 << SUSPEND_REQUEST_INTERRUPT);
				dev_dbg(dev->dev, "Suspend disabled, ignoring\n");
			}
		} else {
			if (dev->driver->resume)
				dev->driver->resume(&dev->gadget);
		}
		stat &= ~tmp;
	}

	/* clear any other status/irqs */
	if (stat)
		net2272_write(dev, IRQSTAT1, stat);

	/* some status we can just ignore */
	stat &= ~((1 << CONTROL_STATUS_INTERRUPT)
			| (1 << SUSPEND_REQUEST_INTERRUPT)
			| (1 << RESUME_INTERRUPT));
	if (!stat)
		return;
	else
		dev_dbg(dev->dev, "unhandled irqstat1 %02x\n", stat);
}

static irqreturn_t net2272_irq(int irq, void *_dev)
{
	struct net2272 *dev = _dev;
#if defined(PLX_PCI_RDK) || defined(PLX_PCI_RDK2)
	u32 intcsr;
#endif
#if defined(PLX_PCI_RDK)
	u8 dmareq;
#endif
	spin_lock(&dev->lock);
#if defined(PLX_PCI_RDK)
	intcsr = readl(dev->rdk1.plx9054_base_addr + INTCSR);

	if ((intcsr & LOCAL_INTERRUPT_TEST) == LOCAL_INTERRUPT_TEST) {
		writel(intcsr & ~(1 << PCI_INTERRUPT_ENABLE),
				dev->rdk1.plx9054_base_addr + INTCSR);
		net2272_handle_stat1_irqs(dev, net2272_read(dev, IRQSTAT1));
		net2272_handle_stat0_irqs(dev, net2272_read(dev, IRQSTAT0));
		intcsr = readl(dev->rdk1.plx9054_base_addr + INTCSR);
		writel(intcsr | (1 << PCI_INTERRUPT_ENABLE),
			dev->rdk1.plx9054_base_addr + INTCSR);
	}
	if ((intcsr & DMA_CHANNEL_0_TEST) == DMA_CHANNEL_0_TEST) {
		writeb((1 << CHANNEL_CLEAR_INTERRUPT | (0 << CHANNEL_ENABLE)),
				dev->rdk1.plx9054_base_addr + DMACSR0);

		dmareq = net2272_read(dev, DMAREQ);
		if (dmareq & 0x01)
			net2272_handle_dma(&dev->ep[2]);
		else
			net2272_handle_dma(&dev->ep[1]);
	}
#endif
#if defined(PLX_PCI_RDK2)
	/* see if PCI int for us by checking irqstat */
	intcsr = readl(dev->rdk2.fpga_base_addr + RDK2_IRQSTAT);
	if (!(intcsr & (1 << NET2272_PCI_IRQ))) {
		spin_unlock(&dev->lock);
		return IRQ_NONE;
	}
	/* check dma interrupts */
#endif
	/* Platform/devcice interrupt handler */
#if !defined(PLX_PCI_RDK)
	net2272_handle_stat1_irqs(dev, net2272_read(dev, IRQSTAT1));
	net2272_handle_stat0_irqs(dev, net2272_read(dev, IRQSTAT0));
#endif
	spin_unlock(&dev->lock);

	return IRQ_HANDLED;
}

static int net2272_present(struct net2272 *dev)
{
	/*
	 * Quick test to see if CPU can communicate properly with the NET2272.
	 * Verifies connection using writes and reads to write/read and
	 * read-only registers.
	 *
	 * This routine is strongly recommended especially during early bring-up
	 * of new hardware, however for designs that do not apply Power On System
	 * Tests (POST) it may discarded (or perhaps minimized).
	 */
	unsigned int ii;
	u8 val, refval;

	/* Verify NET2272 write/read SCRATCH register can write and read */
	refval = net2272_read(dev, SCRATCH);
	for (ii = 0; ii < 0x100; ii += 7) {
		net2272_write(dev, SCRATCH, ii);
		val = net2272_read(dev, SCRATCH);
		if (val != ii) {
			dev_dbg(dev->dev,
				"%s: write/read SCRATCH register test failed: "
				"wrote:0x%2.2x, read:0x%2.2x\n",
				__func__, ii, val);
			return -EINVAL;
		}
	}
	/* To be nice, we write the original SCRATCH value back: */
	net2272_write(dev, SCRATCH, refval);

	/* Verify NET2272 CHIPREV register is read-only: */
	refval = net2272_read(dev, CHIPREV_2272);
	for (ii = 0; ii < 0x100; ii += 7) {
		net2272_write(dev, CHIPREV_2272, ii);
		val = net2272_read(dev, CHIPREV_2272);
		if (val != refval) {
			dev_dbg(dev->dev,
				"%s: write/read CHIPREV register test failed: "
				"wrote 0x%2.2x, read:0x%2.2x expected:0x%2.2x\n",
				__func__, ii, val, refval);
			return -EINVAL;
		}
	}

	/*
	 * Verify NET2272's "NET2270 legacy revision" register
	 *  - NET2272 has two revision registers. The NET2270 legacy revision
	 *    register should read the same value, regardless of the NET2272
	 *    silicon revision.  The legacy register applies to NET2270
	 *    firmware being applied to the NET2272.
	 */
	val = net2272_read(dev, CHIPREV_LEGACY);
	if (val != NET2270_LEGACY_REV) {
		/*
		 * Unexpected legacy revision value
		 * - Perhaps the chip is a NET2270?
		 */
		dev_dbg(dev->dev,
			"%s: WARNING: UNEXPECTED NET2272 LEGACY REGISTER VALUE:\n"
			" - CHIPREV_LEGACY: expected 0x%2.2x, got:0x%2.2x. (Not NET2272?)\n",
			__func__, NET2270_LEGACY_REV, val);
		return -EINVAL;
	}

	/*
	 * Verify NET2272 silicon revision
	 *  - This revision register is appropriate for the silicon version
	 *    of the NET2272
	 */
	val = net2272_read(dev, CHIPREV_2272);
	switch (val) {
	case CHIPREV_NET2272_R1:
		/*
		 * NET2272 Rev 1 has DMA related errata:
		 *  - Newer silicon (Rev 1A or better) required
		 */
		dev_dbg(dev->dev,
			"%s: Rev 1 detected: newer silicon recommended for DMA support\n",
			__func__);
		break;
	case CHIPREV_NET2272_R1A:
		break;
	default:
		/* NET2272 silicon version *may* not work with this firmware */
		dev_dbg(dev->dev,
			"%s: unexpected silicon revision register value: "
			" CHIPREV_2272: 0x%2.2x\n",
			__func__, val);
		/*
		 * Return Success, even though the chip rev is not an expected value
		 *  - Older, pre-built firmware can attempt to operate on newer silicon
		 *  - Often, new silicon is perfectly compatible
		 */
	}

	/* Success: NET2272 checks out OK */
	return 0;
}

static void
net2272_gadget_release(struct device *_dev)
{
	struct net2272 *dev = dev_get_drvdata(_dev);
	kfree(dev);
}

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

static void
net2272_remove(struct net2272 *dev)
{
	usb_del_gadget_udc(&dev->gadget);
	free_irq(dev->irq, dev);
	iounmap(dev->base_addr);
	device_remove_file(dev->dev, &dev_attr_registers);

	dev_info(dev->dev, "unbind\n");
}

static struct net2272 *net2272_probe_init(struct device *dev, unsigned int irq)
{
	struct net2272 *ret;

	if (!irq) {
		dev_dbg(dev, "No IRQ!\n");
		return ERR_PTR(-ENODEV);
	}

	/* alloc, and start init */
	ret = kzalloc(sizeof(*ret), GFP_KERNEL);
	if (!ret)
		return ERR_PTR(-ENOMEM);

	spin_lock_init(&ret->lock);
	ret->irq = irq;
	ret->dev = dev;
	ret->gadget.ops = &net2272_ops;
	ret->gadget.max_speed = USB_SPEED_HIGH;

	/* the "gadget" abstracts/virtualizes the controller */
	ret->gadget.name = driver_name;

	return ret;
}

static int
net2272_probe_fin(struct net2272 *dev, unsigned int irqflags)
{
	int ret;

	/* See if there... */
	if (net2272_present(dev)) {
		dev_warn(dev->dev, "2272 not found!\n");
		ret = -ENODEV;
		goto err;
	}

	net2272_usb_reset(dev);
	net2272_usb_reinit(dev);

	ret = request_irq(dev->irq, net2272_irq, irqflags, driver_name, dev);
	if (ret) {
		dev_err(dev->dev, "request interrupt %i failed\n", dev->irq);
		goto err;
	}

	dev->chiprev = net2272_read(dev, CHIPREV_2272);

	/* done */
	dev_info(dev->dev, "%s\n", driver_desc);
	dev_info(dev->dev, "irq %i, mem %p, chip rev %04x, dma %s\n",
		dev->irq, dev->base_addr, dev->chiprev,
		dma_mode_string());
	dev_info(dev->dev, "version: %s\n", driver_vers);

	ret = device_create_file(dev->dev, &dev_attr_registers);
	if (ret)
		goto err_irq;

	ret = usb_add_gadget_udc_release(dev->dev, &dev->gadget,
			net2272_gadget_release);
	if (ret)
		goto err_add_udc;

	return 0;

err_add_udc:
	device_remove_file(dev->dev, &dev_attr_registers);
 err_irq:
	free_irq(dev->irq, dev);
 err:
	return ret;
}

#ifdef CONFIG_USB_PCI

/*
 * wrap this driver around the specified device, but
 * don't respond over USB until a gadget driver binds to us
 */

static int
net2272_rdk1_probe(struct pci_dev *pdev, struct net2272 *dev)
{
	unsigned long resource, len, tmp;
	void __iomem *mem_mapped_addr[4];
	int ret, i;

	/*
	 * BAR 0 holds PLX 9054 config registers
	 * BAR 1 is i/o memory; unused here
	 * BAR 2 holds EPLD config registers
	 * BAR 3 holds NET2272 registers
	 */

	/* Find and map all address spaces */
	for (i = 0; i < 4; ++i) {
		if (i == 1)
			continue;	/* BAR1 unused */

		resource = pci_resource_start(pdev, i);
		len = pci_resource_len(pdev, i);

		if (!request_mem_region(resource, len, driver_name)) {
			dev_dbg(dev->dev, "controller already in use\n");
			ret = -EBUSY;
			goto err;
		}

		mem_mapped_addr[i] = ioremap_nocache(resource, len);
		if (mem_mapped_addr[i] == NULL) {
			release_mem_region(resource, len);
			dev_dbg(dev->dev, "can't map memory\n");
			ret = -EFAULT;
			goto err;
		}
	}

	dev->rdk1.plx9054_base_addr = mem_mapped_addr[0];
	dev->rdk1.epld_base_addr = mem_mapped_addr[2];
	dev->base_addr = mem_mapped_addr[3];

	/* Set PLX 9054 bus width (16 bits) */
	tmp = readl(dev->rdk1.plx9054_base_addr + LBRD1);
	writel((tmp & ~(3 << MEMORY_SPACE_LOCAL_BUS_WIDTH)) | W16_BIT,
			dev->rdk1.plx9054_base_addr + LBRD1);

	/* Enable PLX 9054 Interrupts */
	writel(readl(dev->rdk1.plx9054_base_addr + INTCSR) |
			(1 << PCI_INTERRUPT_ENABLE) |
			(1 << LOCAL_INTERRUPT_INPUT_ENABLE),
			dev->rdk1.plx9054_base_addr + INTCSR);

	writeb((1 << CHANNEL_CLEAR_INTERRUPT | (0 << CHANNEL_ENABLE)),
			dev->rdk1.plx9054_base_addr + DMACSR0);

	/* reset */
	writeb((1 << EPLD_DMA_ENABLE) |
		(1 << DMA_CTL_DACK) |
		(1 << DMA_TIMEOUT_ENABLE) |
		(1 << USER) |
		(0 << MPX_MODE) |
		(1 << BUSWIDTH) |
		(1 << NET2272_RESET),
		dev->base_addr + EPLD_IO_CONTROL_REGISTER);

	mb();
	writeb(readb(dev->base_addr + EPLD_IO_CONTROL_REGISTER) &
		~(1 << NET2272_RESET),
		dev->base_addr + EPLD_IO_CONTROL_REGISTER);
	udelay(200);

	return 0;

 err:
	while (--i >= 0) {
		iounmap(mem_mapped_addr[i]);
		release_mem_region(pci_resource_start(pdev, i),
			pci_resource_len(pdev, i));
	}

	return ret;
}

static int
net2272_rdk2_probe(struct pci_dev *pdev, struct net2272 *dev)
{
	unsigned long resource, len;
	void __iomem *mem_mapped_addr[2];
	int ret, i;

	/*
	 * BAR 0 holds FGPA config registers
	 * BAR 1 holds NET2272 registers
	 */

	/* Find and map all address spaces, bar2-3 unused in rdk 2 */
	for (i = 0; i < 2; ++i) {
		resource = pci_resource_start(pdev, i);
		len = pci_resource_len(pdev, i);

		if (!request_mem_region(resource, len, driver_name)) {
			dev_dbg(dev->dev, "controller already in use\n");
			ret = -EBUSY;
			goto err;
		}

		mem_mapped_addr[i] = ioremap_nocache(resource, len);
		if (mem_mapped_addr[i] == NULL) {
			release_mem_region(resource, len);
			dev_dbg(dev->dev, "can't map memory\n");
			ret = -EFAULT;
			goto err;
		}
	}

	dev->rdk2.fpga_base_addr = mem_mapped_addr[0];
	dev->base_addr = mem_mapped_addr[1];

	mb();
	/* Set 2272 bus width (16 bits) and reset */
	writel((1 << CHIP_RESET), dev->rdk2.fpga_base_addr + RDK2_LOCCTLRDK);
	udelay(200);
	writel((1 << BUS_WIDTH), dev->rdk2.fpga_base_addr + RDK2_LOCCTLRDK);
	/* Print fpga version number */
	dev_info(dev->dev, "RDK2 FPGA version %08x\n",
		readl(dev->rdk2.fpga_base_addr + RDK2_FPGAREV));
	/* Enable FPGA Interrupts */
	writel((1 << NET2272_PCI_IRQ), dev->rdk2.fpga_base_addr + RDK2_IRQENB);

	return 0;

 err:
	while (--i >= 0) {
		iounmap(mem_mapped_addr[i]);
		release_mem_region(pci_resource_start(pdev, i),
			pci_resource_len(pdev, i));
	}

	return ret;
}

static int
net2272_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
	struct net2272 *dev;
	int ret;

	dev = net2272_probe_init(&pdev->dev, pdev->irq);
	if (IS_ERR(dev))
		return PTR_ERR(dev);
	dev->dev_id = pdev->device;

	if (pci_enable_device(pdev) < 0) {
		ret = -ENODEV;
		goto err_free;
	}

	pci_set_master(pdev);

	switch (pdev->device) {
	case PCI_DEVICE_ID_RDK1: ret = net2272_rdk1_probe(pdev, dev); break;
	case PCI_DEVICE_ID_RDK2: ret = net2272_rdk2_probe(pdev, dev); break;
	default: BUG();
	}
	if (ret)
		goto err_pci;

	ret = net2272_probe_fin(dev, 0);
	if (ret)
		goto err_pci;

	pci_set_drvdata(pdev, dev);

	return 0;

 err_pci:
	pci_disable_device(pdev);
 err_free:
	kfree(dev);

	return ret;
}

static void
net2272_rdk1_remove(struct pci_dev *pdev, struct net2272 *dev)
{
	int i;

	/* disable PLX 9054 interrupts */
	writel(readl(dev->rdk1.plx9054_base_addr + INTCSR) &
		~(1 << PCI_INTERRUPT_ENABLE),
		dev->rdk1.plx9054_base_addr + INTCSR);

	/* clean up resources allocated during probe() */
	iounmap(dev->rdk1.plx9054_base_addr);
	iounmap(dev->rdk1.epld_base_addr);

	for (i = 0; i < 4; ++i) {
		if (i == 1)
			continue;	/* BAR1 unused */
		release_mem_region(pci_resource_start(pdev, i),
			pci_resource_len(pdev, i));
	}
}

static void
net2272_rdk2_remove(struct pci_dev *pdev, struct net2272 *dev)
{
	int i;

	/* disable fpga interrupts
	writel(readl(dev->rdk1.plx9054_base_addr + INTCSR) &
			~(1 << PCI_INTERRUPT_ENABLE),
			dev->rdk1.plx9054_base_addr + INTCSR);
	*/

	/* clean up resources allocated during probe() */
	iounmap(dev->rdk2.fpga_base_addr);

	for (i = 0; i < 2; ++i)
		release_mem_region(pci_resource_start(pdev, i),
			pci_resource_len(pdev, i));
}

static void
net2272_pci_remove(struct pci_dev *pdev)
{
	struct net2272 *dev = pci_get_drvdata(pdev);

	net2272_remove(dev);

	switch (pdev->device) {
	case PCI_DEVICE_ID_RDK1: net2272_rdk1_remove(pdev, dev); break;
	case PCI_DEVICE_ID_RDK2: net2272_rdk2_remove(pdev, dev); break;
	default: BUG();
	}

	pci_disable_device(pdev);

	kfree(dev);
}

/* Table of matching PCI IDs */
static struct pci_device_id pci_ids[] = {
	{	/* RDK 1 card */
		.class       = ((PCI_CLASS_BRIDGE_OTHER << 8) | 0xfe),
		.class_mask  = 0,
		.vendor      = PCI_VENDOR_ID_PLX,
		.device      = PCI_DEVICE_ID_RDK1,
		.subvendor   = PCI_ANY_ID,
		.subdevice   = PCI_ANY_ID,
	},
	{	/* RDK 2 card */
		.class       = ((PCI_CLASS_BRIDGE_OTHER << 8) | 0xfe),
		.class_mask  = 0,
		.vendor      = PCI_VENDOR_ID_PLX,
		.device      = PCI_DEVICE_ID_RDK2,
		.subvendor   = PCI_ANY_ID,
		.subdevice   = PCI_ANY_ID,
	},
	{ }
};
MODULE_DEVICE_TABLE(pci, pci_ids);

static struct pci_driver net2272_pci_driver = {
	.name     = driver_name,
	.id_table = pci_ids,

	.probe    = net2272_pci_probe,
	.remove   = net2272_pci_remove,
};

static int net2272_pci_register(void)
{
	return pci_register_driver(&net2272_pci_driver);
}

static void net2272_pci_unregister(void)
{
	pci_unregister_driver(&net2272_pci_driver);
}

#else
static inline int net2272_pci_register(void) { return 0; }
static inline void net2272_pci_unregister(void) { }
#endif

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

static int
net2272_plat_probe(struct platform_device *pdev)
{
	struct net2272 *dev;
	int ret;
	unsigned int irqflags;
	resource_size_t base, len;
	struct resource *iomem, *iomem_bus, *irq_res;

	irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
	iomem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	iomem_bus = platform_get_resource(pdev, IORESOURCE_BUS, 0);
	if (!irq_res || !iomem) {
		dev_err(&pdev->dev, "must provide irq/base addr");
		return -EINVAL;
	}

	dev = net2272_probe_init(&pdev->dev, irq_res->start);
	if (IS_ERR(dev))
		return PTR_ERR(dev);

	irqflags = 0;
	if (irq_res->flags & IORESOURCE_IRQ_HIGHEDGE)
		irqflags |= IRQF_TRIGGER_RISING;
	if (irq_res->flags & IORESOURCE_IRQ_LOWEDGE)
		irqflags |= IRQF_TRIGGER_FALLING;
	if (irq_res->flags & IORESOURCE_IRQ_HIGHLEVEL)
		irqflags |= IRQF_TRIGGER_HIGH;
	if (irq_res->flags & IORESOURCE_IRQ_LOWLEVEL)
		irqflags |= IRQF_TRIGGER_LOW;

	base = iomem->start;
	len = resource_size(iomem);
	if (iomem_bus)
		dev->base_shift = iomem_bus->start;

	if (!request_mem_region(base, len, driver_name)) {
		dev_dbg(dev->dev, "get request memory region!\n");
		ret = -EBUSY;
		goto err;
	}
	dev->base_addr = ioremap_nocache(base, len);
	if (!dev->base_addr) {
		dev_dbg(dev->dev, "can't map memory\n");
		ret = -EFAULT;
		goto err_req;
	}

	ret = net2272_probe_fin(dev, IRQF_TRIGGER_LOW);
	if (ret)
		goto err_io;

	platform_set_drvdata(pdev, dev);
	dev_info(&pdev->dev, "running in 16-bit, %sbyte swap local bus mode\n",
		(net2272_read(dev, LOCCTL) & (1 << BYTE_SWAP)) ? "" : "no ");

	return 0;

 err_io:
	iounmap(dev->base_addr);
 err_req:
	release_mem_region(base, len);
 err:
	kfree(dev);

	return ret;
}

static int
net2272_plat_remove(struct platform_device *pdev)
{
	struct net2272 *dev = platform_get_drvdata(pdev);

	net2272_remove(dev);

	release_mem_region(pdev->resource[0].start,
		resource_size(&pdev->resource[0]));

	kfree(dev);

	return 0;
}

static struct platform_driver net2272_plat_driver = {
	.probe   = net2272_plat_probe,
	.remove  = net2272_plat_remove,
	.driver  = {
		.name  = driver_name,
	},
	/* FIXME .suspend, .resume */
};
MODULE_ALIAS("platform:net2272");

static int __init net2272_init(void)
{
	int ret;

	ret = net2272_pci_register();
	if (ret)
		return ret;
	ret = platform_driver_register(&net2272_plat_driver);
	if (ret)
		goto err_pci;
	return ret;

err_pci:
	net2272_pci_unregister();
	return ret;
}
module_init(net2272_init);

static void __exit net2272_cleanup(void)
{
	net2272_pci_unregister();
	platform_driver_unregister(&net2272_plat_driver);
}
module_exit(net2272_cleanup);

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR("PLX Technology, Inc.");
MODULE_LICENSE("GPL");