Add realtek target files

Signed-off-by: Roman Yeryomin <roman@advem.lv>

1 files changed, 3066 insertions, 0 deletions

diff --git a/target/linux/realtek/files/drivers/usb/gadget_cathy/net2280.c b/target/linux/realtek/files/drivers/usb/gadget_cathy/net2280.c
new file mode 100644
index 000000000..3acc896a5
--- /dev/null
+++ b/target/linux/realtek/files/drivers/usb/gadget_cathy/net2280.c
@@ -0,0 +1,3066 @@
+/*
+ * Driver for the PLX NET2280 USB device controller.
+ * Specs and errata are available from <http://www.plxtech.com>.
+ *
+ * PLX Technology Inc. (formerly NetChip Technology) supported the
+ * development of this driver.
+ *
+ *
+ * CODE STATUS HIGHLIGHTS
+ *
+ * This driver should work well with most "gadget" drivers, including
+ * the File Storage, Serial, and Ethernet/RNDIS gadget drivers
+ * as well as Gadget Zero and Gadgetfs.
+ *
+ * DMA is enabled by default.  Drivers using transfer queues might use
+ * DMA chaining to remove IRQ latencies between transfers.  (Except when
+ * short OUT transfers happen.)  Drivers can use the req->no_interrupt
+ * hint to completely eliminate some IRQs, if a later IRQ is guaranteed
+ * and DMA chaining is enabled.
+ *
+ * Note that almost all the errata workarounds here are only needed for
+ * rev1 chips.  Rev1a silicon (0110) fixes almost all of them.
+ */
+
+/*
+ * Copyright (C) 2003 David Brownell
+ * Copyright (C) 2003-2005 PLX Technology, Inc.
+ *
+ * Modified Seth Levy 2005 PLX Technology, Inc. to provide compatibility
+ *	with 2282 chip
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#undef	DEBUG		/* messages on error and most fault paths */
+#undef	VERBOSE		/* extra debug messages (success too) */
+
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/dma-mapping.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/smp_lock.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/timer.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/moduleparam.h>
+#include <linux/device.h>
+#include <linux/usb_ch9.h>
+#include <linux/usb_gadget.h>
+
+#include <asm/byteorder.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/system.h>
+#include <asm/unaligned.h>
+
+
+#define	DRIVER_DESC		"PLX NET228x USB Peripheral Controller"
+#define	DRIVER_VERSION		"2005 Sept 27"
+
+#define	DMA_ADDR_INVALID	(~(dma_addr_t)0)
+#define	EP_DONTUSE		13	/* nonzero */
+
+#define USE_RDK_LEDS		/* GPIO pins control three LEDs */
+
+
+static const char driver_name [] = "net2280";
+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", "ep-d",
+	"ep-e", "ep-f",
+};
+
+/* use_dma -- general goodness, fewer interrupts, less cpu load (vs PIO)
+ * use_dma_chaining -- dma descriptor queueing gives even more irq reduction
+ *
+ * The net2280 DMA engines are not tightly integrated with their FIFOs;
+ * not all cases are (yet) handled well in this driver or the silicon.
+ * Some gadget drivers work better with the dma support here than others.
+ * These two parameters let you use PIO or more aggressive DMA.
+ */
+static int use_dma = 1;
+static int use_dma_chaining = 0;
+
+/* "modprobe net2280 use_dma=n" etc */
+module_param (use_dma, bool, S_IRUGO);
+module_param (use_dma_chaining, bool, S_IRUGO);
+
+
+/* mode 0 == ep-{a,b,c,d} 1K fifo each
+ * mode 1 == ep-{a,b} 2K fifo each, ep-{c,d} unavailable
+ * mode 2 == ep-a 2K fifo, ep-{b,c} 1K each, ep-d unavailable
+ */
+static ushort fifo_mode = 0;
+
+/* "modprobe net2280 fifo_mode=1" etc */
+module_param (fifo_mode, ushort, 0644);
+
+/* enable_suspend -- When enabled, the driver will respond to
+ * USB suspend requests by powering down the NET2280.  Otherwise,
+ * USB suspend requests will be ignored.  This is acceptible for
+ * self-powered devices
+ */
+static int enable_suspend = 0;
+
+/* "modprobe net2280 enable_suspend=1" etc */
+module_param (enable_suspend, bool, S_IRUGO);
+
+
+#define	DIR_STRING(bAddress) (((bAddress) & USB_DIR_IN) ? "in" : "out")
+
+#if defined(CONFIG_USB_GADGET_DEBUG_FILES) || defined (DEBUG)
+static char *type_string (u8 bmAttributes)
+{
+	switch ((bmAttributes) & USB_ENDPOINT_XFERTYPE_MASK) {
+	case USB_ENDPOINT_XFER_BULK:	return "bulk";
+	case USB_ENDPOINT_XFER_ISOC:	return "iso";
+	case USB_ENDPOINT_XFER_INT:	return "intr";
+	};
+	return "control";
+}
+#endif
+
+#include "net2280.h"
+
+#define valid_bit	__constant_cpu_to_le32 (1 << VALID_BIT)
+#define dma_done_ie	__constant_cpu_to_le32 (1 << DMA_DONE_INTERRUPT_ENABLE)
+
+/*-------------------------------------------------------------------------*/
+
+static int
+net2280_enable (struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
+{
+	struct net2280		*dev;
+	struct net2280_ep	*ep;
+	u32			max, tmp;
+	unsigned long		flags;
+
+	ep = container_of (_ep, struct net2280_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;
+
+	/* erratum 0119 workaround ties up an endpoint number */
+	if ((desc->bEndpointAddress & 0x0f) == EP_DONTUSE)
+		return -EDOM;
+
+	/* sanity check ep-e/ep-f since their fifos are small */
+	max = le16_to_cpu (desc->wMaxPacketSize) & 0x1fff;
+	if (ep->num > 4 && max > 64)
+		return -ERANGE;
+
+	spin_lock_irqsave (&dev->lock, flags);
+	_ep->maxpacket = max & 0x7ff;
+	ep->desc = desc;
+
+	/* ep_reset() has already been called */
+	ep->stopped = 0;
+	ep->out_overflow = 0;
+
+	/* set speed-dependent max packet; may kick in high bandwidth */
+	set_idx_reg (dev->regs, REG_EP_MAXPKT (dev, ep->num), max);
+
+	/* FIFO lines can't go to different packets.  PIO is ok, so
+	 * use it instead of troublesome (non-bulk) multi-packet DMA.
+	 */
+	if (ep->dma && (max % 4) != 0 && use_dma_chaining) {
+		DEBUG (ep->dev, "%s, no dma for maxpacket %d\n",
+			ep->ep.name, ep->ep.maxpacket);
+		ep->dma = NULL;
+	}
+
+	/* set type, direction, address; reset fifo counters */
+	writel ((1 << FIFO_FLUSH), &ep->regs->ep_stat);
+	tmp = (desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK);
+	if (tmp == USB_ENDPOINT_XFER_INT) {
+		/* erratum 0105 workaround prevents hs NYET */
+		if (dev->chiprev == 0100
+				&& dev->gadget.speed == USB_SPEED_HIGH
+				&& !(desc->bEndpointAddress & USB_DIR_IN))
+			writel ((1 << CLEAR_NAK_OUT_PACKETS_MODE),
+				&ep->regs->ep_rsp);
+	} else if (tmp == USB_ENDPOINT_XFER_BULK) {
+		/* 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 = (tmp == USB_ENDPOINT_XFER_ISOC) ? 1 : 0;
+	tmp <<= ENDPOINT_TYPE;
+	tmp |= desc->bEndpointAddress;
+	tmp |= (4 << ENDPOINT_BYTE_COUNT);	/* default full fifo lines */
+	tmp |= 1 << ENDPOINT_ENABLE;
+	wmb ();
+
+	/* for OUT transfers, block the rx fifo until a read is posted */
+	ep->is_in = (tmp & USB_DIR_IN) != 0;
+	if (!ep->is_in)
+		writel ((1 << SET_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
+	else if (dev->pdev->device != 0x2280) {
+		/* Added for 2282, Don't use nak packets on an in endpoint,
+		 * this was ignored on 2280
+		 */
+		writel ((1 << CLEAR_NAK_OUT_PACKETS)
+			| (1 << CLEAR_NAK_OUT_PACKETS_MODE), &ep->regs->ep_rsp);
+	}
+
+	writel (tmp, &ep->regs->ep_cfg);
+
+	/* enable irqs */
+	if (!ep->dma) {				/* pio, per-packet */
+		tmp = (1 << ep->num) | readl (&dev->regs->pciirqenb0);
+		writel (tmp, &dev->regs->pciirqenb0);
+
+		tmp = (1 << DATA_PACKET_RECEIVED_INTERRUPT_ENABLE)
+			| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT_ENABLE);
+		if (dev->pdev->device == 0x2280)
+			tmp |= readl (&ep->regs->ep_irqenb);
+		writel (tmp, &ep->regs->ep_irqenb);
+	} else {				/* dma, per-request */
+		tmp = (1 << (8 + ep->num));	/* completion */
+		tmp |= readl (&dev->regs->pciirqenb1);
+		writel (tmp, &dev->regs->pciirqenb1);
+
+		/* for short OUT transfers, dma completions can't
+		 * advance the queue; do it pio-style, by hand.
+		 * NOTE erratum 0112 workaround #2
+		 */
+		if ((desc->bEndpointAddress & USB_DIR_IN) == 0) {
+			tmp = (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT_ENABLE);
+			writel (tmp, &ep->regs->ep_irqenb);
+
+			tmp = (1 << ep->num) | readl (&dev->regs->pciirqenb0);
+			writel (tmp, &dev->regs->pciirqenb0);
+		}
+	}
+
+	tmp = desc->bEndpointAddress;
+	DEBUG (dev, "enabled %s (ep%d%s-%s) %s max %04x\n",
+		_ep->name, tmp & 0x0f, DIR_STRING (tmp),
+		type_string (desc->bmAttributes),
+		ep->dma ? "dma" : "pio", max);
+
+	/* pci writes may still be posted */
+	spin_unlock_irqrestore (&dev->lock, flags);
+	return 0;
+}
+
+static int handshake (u32 __iomem *ptr, u32 mask, u32 done, int usec)
+{
+	u32	result;
+
+	do {
+		result = readl (ptr);
+		if (result == ~(u32)0)		/* "device unplugged" */
+			return -ENODEV;
+		result &= mask;
+		if (result == done)
+			return 0;
+		udelay (1);
+		usec--;
+	} while (usec > 0);
+	return -ETIMEDOUT;
+}
+
+static const struct usb_ep_ops net2280_ep_ops;
+
+static void ep_reset (struct net2280_regs __iomem *regs, struct net2280_ep *ep)
+{
+	u32		tmp;
+
+	ep->desc = NULL;
+	INIT_LIST_HEAD (&ep->queue);
+
+	ep->ep.maxpacket = ~0;
+	ep->ep.ops = &net2280_ep_ops;
+
+	/* disable the dma, irqs, endpoint... */
+	if (ep->dma) {
+		writel (0, &ep->dma->dmactl);
+		writel (  (1 << DMA_SCATTER_GATHER_DONE_INTERRUPT)
+			| (1 << DMA_TRANSACTION_DONE_INTERRUPT)
+			| (1 << DMA_ABORT)
+			, &ep->dma->dmastat);
+
+		tmp = readl (&regs->pciirqenb0);
+		tmp &= ~(1 << ep->num);
+		writel (tmp, &regs->pciirqenb0);
+	} else {
+		tmp = readl (&regs->pciirqenb1);
+		tmp &= ~(1 << (8 + ep->num));	/* completion */
+		writel (tmp, &regs->pciirqenb1);
+	}
+	writel (0, &ep->regs->ep_irqenb);
+
+	/* init to our chosen defaults, notably so that we NAK OUT
+	 * packets until the driver queues a read (+note erratum 0112)
+	 */
+	if (!ep->is_in || ep->dev->pdev->device == 0x2280) {
+		tmp = (1 << SET_NAK_OUT_PACKETS_MODE)
+		| (1 << SET_NAK_OUT_PACKETS)
+		| (1 << CLEAR_EP_HIDE_STATUS_PHASE)
+		| (1 << CLEAR_INTERRUPT_MODE);
+	} else {
+		/* added for 2282 */
+		tmp = (1 << CLEAR_NAK_OUT_PACKETS_MODE)
+		| (1 << CLEAR_NAK_OUT_PACKETS)
+		| (1 << CLEAR_EP_HIDE_STATUS_PHASE)
+		| (1 << CLEAR_INTERRUPT_MODE);
+	}
+
+	if (ep->num != 0) {
+		tmp |= (1 << CLEAR_ENDPOINT_TOGGLE)
+			| (1 << CLEAR_ENDPOINT_HALT);
+	}
+	writel (tmp, &ep->regs->ep_rsp);
+
+	/* scrub most status bits, and flush any fifo state */
+	if (ep->dev->pdev->device == 0x2280)
+		tmp = (1 << FIFO_OVERFLOW)
+			| (1 << FIFO_UNDERFLOW);
+	else
+		tmp = 0;
+
+	writel (tmp | (1 << TIMEOUT)
+		| (1 << USB_STALL_SENT)
+		| (1 << USB_IN_NAK_SENT)
+		| (1 << USB_IN_ACK_RCVD)
+		| (1 << USB_OUT_PING_NAK_SENT)
+		| (1 << USB_OUT_ACK_SENT)
+		| (1 << FIFO_FLUSH)
+		| (1 << SHORT_PACKET_OUT_DONE_INTERRUPT)
+		| (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)
+		| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
+		| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
+		| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
+		| (1 << DATA_IN_TOKEN_INTERRUPT)
+		, &ep->regs->ep_stat);
+
+	/* fifo size is handled separately */
+}
+
+static void nuke (struct net2280_ep *);
+
+static int net2280_disable (struct usb_ep *_ep)
+{
+	struct net2280_ep	*ep;
+	unsigned long		flags;
+
+	ep = container_of (_ep, struct net2280_ep, ep);
+	if (!_ep || !ep->desc || _ep->name == ep0name)
+		return -EINVAL;
+
+	spin_lock_irqsave (&ep->dev->lock, flags);
+	nuke (ep);
+	ep_reset (ep->dev->regs, ep);
+
+	VDEBUG (ep->dev, "disabled %s %s\n",
+			ep->dma ? "dma" : "pio", _ep->name);
+
+	/* synch memory views with the device */
+	(void) readl (&ep->regs->ep_cfg);
+
+	if (use_dma && !ep->dma && ep->num >= 1 && ep->num <= 4)
+		ep->dma = &ep->dev->dma [ep->num - 1];
+
+	spin_unlock_irqrestore (&ep->dev->lock, flags);
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static struct usb_request *
+net2280_alloc_request (struct usb_ep *_ep, gfp_t gfp_flags)
+{
+	struct net2280_ep	*ep;
+	struct net2280_request	*req;
+
+	if (!_ep)
+		return NULL;
+	ep = container_of (_ep, struct net2280_ep, ep);
+
+	req = kzalloc(sizeof(*req), gfp_flags);
+	if (!req)
+		return NULL;
+
+	req->req.dma = DMA_ADDR_INVALID;
+	INIT_LIST_HEAD (&req->queue);
+
+	/* this dma descriptor may be swapped with the previous dummy */
+	if (ep->dma) {
+		struct net2280_dma	*td;
+
+		td = pci_pool_alloc (ep->dev->requests, gfp_flags,
+				&req->td_dma);
+		if (!td) {
+			kfree (req);
+			return NULL;
+		}
+		td->dmacount = 0;	/* not VALID */
+		td->dmaaddr = __constant_cpu_to_le32 (DMA_ADDR_INVALID);
+		td->dmadesc = td->dmaaddr;
+		req->td = td;
+	}
+	return &req->req;
+}
+
+static void
+net2280_free_request (struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct net2280_ep	*ep;
+	struct net2280_request	*req;
+
+	ep = container_of (_ep, struct net2280_ep, ep);
+	if (!_ep || !_req)
+		return;
+
+	req = container_of (_req, struct net2280_request, req);
+	WARN_ON (!list_empty (&req->queue));
+	if (req->td)
+		pci_pool_free (ep->dev->requests, req->td, req->td_dma);
+	kfree (req);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * dma-coherent memory allocation (for dma-capable endpoints)
+ *
+ * NOTE: the dma_*_coherent() API calls suck.  Most implementations are
+ * (a) page-oriented, so small buffers lose big; and (b) asymmetric with
+ * respect to calls with irqs disabled:  alloc is safe, free is not.
+ * We currently work around (b), but not (a).
+ */
+
+static void *
+net2280_alloc_buffer (
+	struct usb_ep		*_ep,
+	unsigned		bytes,
+	dma_addr_t		*dma,
+	gfp_t			gfp_flags
+)
+{
+	void			*retval;
+	struct net2280_ep	*ep;
+
+	ep = container_of (_ep, struct net2280_ep, ep);
+	if (!_ep)
+		return NULL;
+	*dma = DMA_ADDR_INVALID;
+
+	if (ep->dma)
+		retval = dma_alloc_coherent(&ep->dev->pdev->dev,
+				bytes, dma, gfp_flags);
+	else
+		retval = kmalloc(bytes, gfp_flags);
+	return retval;
+}
+
+static DEFINE_SPINLOCK(buflock);
+static LIST_HEAD(buffers);
+
+struct free_record {
+	struct list_head	list;
+	struct device		*dev;
+	unsigned		bytes;
+	dma_addr_t		dma;
+};
+
+static void do_free(unsigned long ignored)
+{
+	spin_lock_irq(&buflock);
+	while (!list_empty(&buffers)) {
+		struct free_record	*buf;
+
+		buf = list_entry(buffers.next, struct free_record, list);
+		list_del(&buf->list);
+		spin_unlock_irq(&buflock);
+
+		dma_free_coherent(buf->dev, buf->bytes, buf, buf->dma);
+
+		spin_lock_irq(&buflock);
+	}
+	spin_unlock_irq(&buflock);
+}
+
+static DECLARE_TASKLET(deferred_free, do_free, 0);
+
+static void
+net2280_free_buffer (
+	struct usb_ep *_ep,
+	void *address,
+	dma_addr_t dma,
+	unsigned bytes
+) {
+	/* free memory into the right allocator */
+	if (dma != DMA_ADDR_INVALID) {
+		struct net2280_ep	*ep;
+		struct free_record	*buf = address;
+		unsigned long		flags;
+
+		ep = container_of(_ep, struct net2280_ep, ep);
+		if (!_ep)
+			return;
+
+		ep = container_of (_ep, struct net2280_ep, ep);
+		buf->dev = &ep->dev->pdev->dev;
+		buf->bytes = bytes;
+		buf->dma = dma;
+
+		spin_lock_irqsave(&buflock, flags);
+		list_add_tail(&buf->list, &buffers);
+		tasklet_schedule(&deferred_free);
+		spin_unlock_irqrestore(&buflock, flags);
+	} else
+		kfree (address);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* load a packet into the fifo we use for usb IN transfers.
+ * works for all endpoints.
+ *
+ * NOTE: pio with ep-a..ep-d could stuff multiple packets into the fifo
+ * at a time, but this code is simpler because it knows it only writes
+ * one packet.  ep-a..ep-d should use dma instead.
+ */
+static void
+write_fifo (struct net2280_ep *ep, struct usb_request *req)
+{
+	struct net2280_ep_regs	__iomem *regs = ep->regs;
+	u8			*buf;
+	u32			tmp;
+	unsigned		count, total;
+
+	/* INVARIANT:  fifo is currently empty. (testable) */
+
+	if (req) {
+		buf = req->buf + req->actual;
+		prefetch (buf);
+		total = req->length - req->actual;
+	} else {
+		total = 0;
+		buf = NULL;
+	}
+
+	/* write just one packet at a time */
+	count = ep->ep.maxpacket;
+	if (count > total)	/* min() cannot be used on a bitfield */
+		count = total;
+
+	VDEBUG (ep->dev, "write %s fifo (IN) %d bytes%s req %p\n",
+			ep->ep.name, count,
+			(count != ep->ep.maxpacket) ? " (short)" : "",
+			req);
+	while (count >= 4) {
+		/* NOTE be careful if you try to align these. fifo lines
+		 * should normally be full (4 bytes) and successive partial
+		 * lines are ok only in certain cases.
+		 */
+		tmp = get_unaligned ((u32 *)buf);
+		cpu_to_le32s (&tmp);
+		writel (tmp, &regs->ep_data);
+		buf += 4;
+		count -= 4;
+	}
+
+	/* last fifo entry is "short" unless we wrote a full packet.
+	 * also explicitly validate last word in (periodic) transfers
+	 * when maxpacket is not a multiple of 4 bytes.
+	 */
+	if (count || total < ep->ep.maxpacket) {
+		tmp = count ? get_unaligned ((u32 *)buf) : count;
+		cpu_to_le32s (&tmp);
+		set_fifo_bytecount (ep, count & 0x03);
+		writel (tmp, &regs->ep_data);
+	}
+
+	/* pci writes may still be posted */
+}
+
+/* work around erratum 0106: PCI and USB race over the OUT fifo.
+ * caller guarantees chiprev 0100, out endpoint is NAKing, and
+ * there's no real data in the fifo.
+ *
+ * NOTE:  also used in cases where that erratum doesn't apply:
+ * where the host wrote "too much" data to us.
+ */
+static void out_flush (struct net2280_ep *ep)
+{
+	u32	__iomem *statp;
+	u32	tmp;
+
+	ASSERT_OUT_NAKING (ep);
+
+	statp = &ep->regs->ep_stat;
+	writel (  (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
+		| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
+		, statp);
+	writel ((1 << FIFO_FLUSH), statp);
+	mb ();
+	tmp = readl (statp);
+	if (tmp & (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
+			/* high speed did bulk NYET; fifo isn't filling */
+			&& ep->dev->gadget.speed == USB_SPEED_FULL) {
+		unsigned	usec;
+
+		usec = 50;		/* 64 byte bulk/interrupt */
+		handshake (statp, (1 << USB_OUT_PING_NAK_SENT),
+				(1 << USB_OUT_PING_NAK_SENT), usec);
+		/* NAK done; now CLEAR_NAK_OUT_PACKETS is safe */
+	}
+}
+
+/* unload packet(s) from the fifo we use for usb OUT transfers.
+ * returns true iff the request completed, because of short packet
+ * or the request buffer having filled with full packets.
+ *
+ * for ep-a..ep-d this will read multiple packets out when they
+ * have been accepted.
+ */
+static int
+read_fifo (struct net2280_ep *ep, struct net2280_request *req)
+{
+	struct net2280_ep_regs	__iomem *regs = ep->regs;
+	u8			*buf = req->req.buf + req->req.actual;
+	unsigned		count, tmp, is_short;
+	unsigned		cleanup = 0, prevent = 0;
+
+	/* erratum 0106 ... packets coming in during fifo reads might
+	 * be incompletely rejected.  not all cases have workarounds.
+	 */
+	if (ep->dev->chiprev == 0x0100
+			&& ep->dev->gadget.speed == USB_SPEED_FULL) {
+		udelay (1);
+		tmp = readl (&ep->regs->ep_stat);
+		if ((tmp & (1 << NAK_OUT_PACKETS)))
+			cleanup = 1;
+		else if ((tmp & (1 << FIFO_FULL))) {
+			start_out_naking (ep);
+			prevent = 1;
+		}
+		/* else: hope we don't see the problem */
+	}
+
+	/* never overflow the rx buffer. the fifo reads packets until
+	 * it sees a short one; we might not be ready for them all.
+	 */
+	prefetchw (buf);
+	count = readl (&regs->ep_avail);
+	if (unlikely (count == 0)) {
+		udelay (1);
+		tmp = readl (&ep->regs->ep_stat);
+		count = readl (&regs->ep_avail);
+		/* handled that data already? */
+		if (count == 0 && (tmp & (1 << NAK_OUT_PACKETS)) == 0)
+			return 0;
+	}
+
+	tmp = req->req.length - req->req.actual;
+	if (count > tmp) {
+		/* as with DMA, data overflow gets flushed */
+		if ((tmp % ep->ep.maxpacket) != 0) {
+			ERROR (ep->dev,
+				"%s out fifo %d bytes, expected %d\n",
+				ep->ep.name, count, tmp);
+			req->req.status = -EOVERFLOW;
+			cleanup = 1;
+			/* NAK_OUT_PACKETS will be set, so flushing is safe;
+			 * the next read will start with the next packet
+			 */
+		} /* else it's a ZLP, no worries */
+		count = tmp;
+	}
+	req->req.actual += count;
+
+	is_short = (count == 0) || ((count % ep->ep.maxpacket) != 0);
+
+	VDEBUG (ep->dev, "read %s fifo (OUT) %d bytes%s%s%s req %p %d/%d\n",
+			ep->ep.name, count, is_short ? " (short)" : "",
+			cleanup ? " flush" : "", prevent ? " nak" : "",
+			req, req->req.actual, req->req.length);
+
+	while (count >= 4) {
+		tmp = readl (&regs->ep_data);
+		cpu_to_le32s (&tmp);
+		put_unaligned (tmp, (u32 *)buf);
+		buf += 4;
+		count -= 4;
+	}
+	if (count) {
+		tmp = readl (&regs->ep_data);
+		/* LE conversion is implicit here: */
+		do {
+			*buf++ = (u8) tmp;
+			tmp >>= 8;
+		} while (--count);
+	}
+	if (cleanup)
+		out_flush (ep);
+	if (prevent) {
+		writel ((1 << CLEAR_NAK_OUT_PACKETS), &ep->regs->ep_rsp);
+		(void) readl (&ep->regs->ep_rsp);
+	}
+
+	return is_short || ((req->req.actual == req->req.length)
+				&& !req->req.zero);
+}
+
+/* fill out dma descriptor to match a given request */
+static void
+fill_dma_desc (struct net2280_ep *ep, struct net2280_request *req, int valid)
+{
+	struct net2280_dma	*td = req->td;
+	u32			dmacount = req->req.length;
+
+	/* don't let DMA continue after a short OUT packet,
+	 * so overruns can't affect the next transfer.
+	 * in case of overruns on max-size packets, we can't
+	 * stop the fifo from filling but we can flush it.
+	 */
+	if (ep->is_in)
+		dmacount |= (1 << DMA_DIRECTION);
+	if ((!ep->is_in && (dmacount % ep->ep.maxpacket) != 0)
+			|| ep->dev->pdev->device != 0x2280)
+		dmacount |= (1 << END_OF_CHAIN);
+
+	req->valid = valid;
+	if (valid)
+		dmacount |= (1 << VALID_BIT);
+	if (likely(!req->req.no_interrupt || !use_dma_chaining))
+		dmacount |= (1 << DMA_DONE_INTERRUPT_ENABLE);
+
+	/* td->dmadesc = previously set by caller */
+	td->dmaaddr = cpu_to_le32 (req->req.dma);
+
+	/* 2280 may be polling VALID_BIT through ep->dma->dmadesc */
+	wmb ();
+	td->dmacount = cpu_to_le32p (&dmacount);
+}
+
+static const u32 dmactl_default =
+		  (1 << DMA_SCATTER_GATHER_DONE_INTERRUPT)
+		| (1 << DMA_CLEAR_COUNT_ENABLE)
+		/* erratum 0116 workaround part 1 (use POLLING) */
+		| (POLL_100_USEC << DESCRIPTOR_POLLING_RATE)
+		| (1 << DMA_VALID_BIT_POLLING_ENABLE)
+		| (1 << DMA_VALID_BIT_ENABLE)
+		| (1 << DMA_SCATTER_GATHER_ENABLE)
+		/* erratum 0116 workaround part 2 (no AUTOSTART) */
+		| (1 << DMA_ENABLE);
+
+static inline void spin_stop_dma (struct net2280_dma_regs __iomem *dma)
+{
+	handshake (&dma->dmactl, (1 << DMA_ENABLE), 0, 50);
+}
+
+static inline void stop_dma (struct net2280_dma_regs __iomem *dma)
+{
+	writel (readl (&dma->dmactl) & ~(1 << DMA_ENABLE), &dma->dmactl);
+	spin_stop_dma (dma);
+}
+
+static void start_queue (struct net2280_ep *ep, u32 dmactl, u32 td_dma)
+{
+	struct net2280_dma_regs	__iomem *dma = ep->dma;
+	unsigned int tmp = (1 << VALID_BIT) | (ep->is_in << DMA_DIRECTION);
+
+	if (ep->dev->pdev->device != 0x2280)
+		tmp |= (1 << END_OF_CHAIN);
+
+	writel (tmp, &dma->dmacount);
+	writel (readl (&dma->dmastat), &dma->dmastat);
+
+	writel (td_dma, &dma->dmadesc);
+	writel (dmactl, &dma->dmactl);
+
+	/* erratum 0116 workaround part 3:  pci arbiter away from net2280 */
+	(void) readl (&ep->dev->pci->pcimstctl);
+
+	writel ((1 << DMA_START), &dma->dmastat);
+
+	if (!ep->is_in)
+		stop_out_naking (ep);
+}
+
+static void start_dma (struct net2280_ep *ep, struct net2280_request *req)
+{
+	u32			tmp;
+	struct net2280_dma_regs	__iomem *dma = ep->dma;
+
+	/* FIXME can't use DMA for ZLPs */
+
+	/* on this path we "know" there's no dma active (yet) */
+	WARN_ON (readl (&dma->dmactl) & (1 << DMA_ENABLE));
+	writel (0, &ep->dma->dmactl);
+
+	/* previous OUT packet might have been short */
+	if (!ep->is_in && ((tmp = readl (&ep->regs->ep_stat))
+				& (1 << NAK_OUT_PACKETS)) != 0) {
+		writel ((1 << SHORT_PACKET_TRANSFERRED_INTERRUPT),
+			&ep->regs->ep_stat);
+
+		tmp = readl (&ep->regs->ep_avail);
+		if (tmp) {
+			writel (readl (&dma->dmastat), &dma->dmastat);
+
+			/* transfer all/some fifo data */
+			writel (req->req.dma, &dma->dmaaddr);
+			tmp = min (tmp, req->req.length);
+
+			/* dma irq, faking scatterlist status */
+			req->td->dmacount = cpu_to_le32 (req->req.length - tmp);
+			writel ((1 << DMA_DONE_INTERRUPT_ENABLE)
+				| tmp, &dma->dmacount);
+			req->td->dmadesc = 0;
+			req->valid = 1;
+
+			writel ((1 << DMA_ENABLE), &dma->dmactl);
+			writel ((1 << DMA_START), &dma->dmastat);
+			return;
+		}
+	}
+
+	tmp = dmactl_default;
+
+	/* force packet boundaries between dma requests, but prevent the
+	 * controller from automagically writing a last "short" packet
+	 * (zero length) unless the driver explicitly said to do that.
+	 */
+	if (ep->is_in) {
+		if (likely ((req->req.length % ep->ep.maxpacket) != 0
+				|| req->req.zero)) {
+			tmp |= (1 << DMA_FIFO_VALIDATE);
+			ep->in_fifo_validate = 1;
+		} else
+			ep->in_fifo_validate = 0;
+	}
+
+	/* init req->td, pointing to the current dummy */
+	req->td->dmadesc = cpu_to_le32 (ep->td_dma);
+	fill_dma_desc (ep, req, 1);
+
+	if (!use_dma_chaining)
+		req->td->dmacount |= __constant_cpu_to_le32 (1 << END_OF_CHAIN);
+
+	start_queue (ep, tmp, req->td_dma);
+}
+
+static inline void
+queue_dma (struct net2280_ep *ep, struct net2280_request *req, int valid)
+{
+	struct net2280_dma	*end;
+	dma_addr_t		tmp;
+
+	/* swap new dummy for old, link; fill and maybe activate */
+	end = ep->dummy;
+	ep->dummy = req->td;
+	req->td = end;
+
+	tmp = ep->td_dma;
+	ep->td_dma = req->td_dma;
+	req->td_dma = tmp;
+
+	end->dmadesc = cpu_to_le32 (ep->td_dma);
+
+	fill_dma_desc (ep, req, valid);
+}
+
+static void
+done (struct net2280_ep *ep, struct net2280_request *req, int status)
+{
+	struct net2280		*dev;
+	unsigned		stopped = ep->stopped;
+
+	list_del_init (&req->queue);
+
+	if (req->req.status == -EINPROGRESS)
+		req->req.status = status;
+	else
+		status = req->req.status;
+
+	dev = ep->dev;
+	if (req->mapped) {
+		pci_unmap_single (dev->pdev, req->req.dma, req->req.length,
+			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
+		req->req.dma = DMA_ADDR_INVALID;
+		req->mapped = 0;
+	}
+
+	if (status && status != -ESHUTDOWN)
+		VDEBUG (dev, "complete %s req %p stat %d len %u/%u\n",
+			ep->ep.name, &req->req, status,
+			req->req.actual, req->req.length);
+
+	/* don't modify queue heads during completion callback */
+	ep->stopped = 1;
+	spin_unlock (&dev->lock);
+	req->req.complete (&ep->ep, &req->req);
+	spin_lock (&dev->lock);
+	ep->stopped = stopped;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int
+net2280_queue (struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
+{
+	struct net2280_request	*req;
+	struct net2280_ep	*ep;
+	struct net2280		*dev;
+	unsigned long		flags;
+
+	/* we always require a cpu-view buffer, so that we can
+	 * always use pio (as fallback or whatever).
+	 */
+	req = container_of (_req, struct net2280_request, req);
+	if (!_req || !_req->complete || !_req->buf
+			|| !list_empty (&req->queue))
+		return -EINVAL;
+	if (_req->length > (~0 & DMA_BYTE_COUNT_MASK))
+		return -EDOM;
+	ep = container_of (_ep, struct net2280_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;
+
+	/* FIXME implement PIO fallback for ZLPs with DMA */
+	if (ep->dma && _req->length == 0)
+		return -EOPNOTSUPP;
+
+	/* set up dma mapping in case the caller didn't */
+	if (ep->dma && _req->dma == DMA_ADDR_INVALID) {
+		_req->dma = pci_map_single (dev->pdev, _req->buf, _req->length,
+			ep->is_in ? PCI_DMA_TODEVICE : PCI_DMA_FROMDEVICE);
+		req->mapped = 1;
+	}
+
+#if 0
+	VDEBUG (dev, "%s queue req %p, len %d buf %p\n",
+			_ep->name, _req, _req->length, _req->buf);
+#endif
+
+	spin_lock_irqsave (&dev->lock, flags);
+
+	_req->status = -EINPROGRESS;
+	_req->actual = 0;
+
+	/* kickstart this i/o queue? */
+	if (list_empty (&ep->queue) && !ep->stopped) {
+		/* use DMA if the endpoint supports it, else pio */
+		if (ep->dma)
+			start_dma (ep, req);
+		else {
+			/* maybe there's no control data, just status ack */
+			if (ep->num == 0 && _req->length == 0) {
+				allow_status (ep);
+				done (ep, req, 0);
+				VDEBUG (dev, "%s status ack\n", ep->ep.name);
+				goto done;
+			}
+
+			/* PIO ... stuff the fifo, or unblock it.  */
+			if (ep->is_in)
+				write_fifo (ep, _req);
+			else if (list_empty (&ep->queue)) {
+				u32	s;
+
+				/* OUT FIFO might have packet(s) buffered */
+				s = readl (&ep->regs->ep_stat);
+				if ((s & (1 << FIFO_EMPTY)) == 0) {
+					/* note:  _req->short_not_ok is
+					 * ignored here since PIO _always_
+					 * stops queue advance here, and
+					 * _req->status doesn't change for
+					 * short reads (only _req->actual)
+					 */
+					if (read_fifo (ep, req)) {
+						done (ep, req, 0);
+						if (ep->num == 0)
+							allow_status (ep);
+						/* don't queue it */
+						req = NULL;
+					} else
+						s = readl (&ep->regs->ep_stat);
+				}
+
+				/* don't NAK, let the fifo fill */
+				if (req && (s & (1 << NAK_OUT_PACKETS)))
+					writel ((1 << CLEAR_NAK_OUT_PACKETS),
+							&ep->regs->ep_rsp);
+			}
+		}
+
+	} else if (ep->dma) {
+		int	valid = 1;
+
+		if (ep->is_in) {
+			int	expect;
+
+			/* preventing magic zlps is per-engine state, not
+			 * per-transfer; irq logic must recover hiccups.
+			 */
+			expect = likely (req->req.zero
+				|| (req->req.length % ep->ep.maxpacket) != 0);
+			if (expect != ep->in_fifo_validate)
+				valid = 0;
+		}
+		queue_dma (ep, req, valid);
+
+	} /* else the irq handler advances the queue. */
+
+	if (req)
+		list_add_tail (&req->queue, &ep->queue);
+done:
+	spin_unlock_irqrestore (&dev->lock, flags);
+
+	/* pci writes may still be posted */
+	return 0;
+}
+
+static inline void
+dma_done (
+	struct net2280_ep *ep,
+	struct net2280_request *req,
+	u32 dmacount,
+	int status
+)
+{
+	req->req.actual = req->req.length - (DMA_BYTE_COUNT_MASK & dmacount);
+	done (ep, req, status);
+}
+
+static void restart_dma (struct net2280_ep *ep);
+
+static void scan_dma_completions (struct net2280_ep *ep)
+{
+	/* only look at descriptors that were "naturally" retired,
+	 * so fifo and list head state won't matter
+	 */
+	while (!list_empty (&ep->queue)) {
+		struct net2280_request	*req;
+		u32			tmp;
+
+		req = list_entry (ep->queue.next,
+				struct net2280_request, queue);
+		if (!req->valid)
+			break;
+		rmb ();
+		tmp = le32_to_cpup (&req->td->dmacount);
+		if ((tmp & (1 << VALID_BIT)) != 0)
+			break;
+
+		/* SHORT_PACKET_TRANSFERRED_INTERRUPT handles "usb-short"
+		 * cases where DMA must be aborted; this code handles
+		 * all non-abort DMA completions.
+		 */
+		if (unlikely (req->td->dmadesc == 0)) {
+			/* paranoia */
+			tmp = readl (&ep->dma->dmacount);
+			if (tmp & DMA_BYTE_COUNT_MASK)
+				break;
+			/* single transfer mode */
+			dma_done (ep, req, tmp, 0);
+			break;
+		} else if (!ep->is_in
+				&& (req->req.length % ep->ep.maxpacket) != 0) {
+			tmp = readl (&ep->regs->ep_stat);
+
+			/* AVOID TROUBLE HERE by not issuing short reads from
+			 * your gadget driver.  That helps avoids errata 0121,
+			 * 0122, and 0124; not all cases trigger the warning.
+			 */
+			if ((tmp & (1 << NAK_OUT_PACKETS)) == 0) {
+				WARN (ep->dev, "%s lost packet sync!\n",
+						ep->ep.name);
+				req->req.status = -EOVERFLOW;
+			} else if ((tmp = readl (&ep->regs->ep_avail)) != 0) {
+				/* fifo gets flushed later */
+				ep->out_overflow = 1;
+				DEBUG (ep->dev, "%s dma, discard %d len %d\n",
+						ep->ep.name, tmp,
+						req->req.length);
+				req->req.status = -EOVERFLOW;
+			}
+		}
+		dma_done (ep, req, tmp, 0);
+	}
+}
+
+static void restart_dma (struct net2280_ep *ep)
+{
+	struct net2280_request	*req;
+	u32			dmactl = dmactl_default;
+
+	if (ep->stopped)
+		return;
+	req = list_entry (ep->queue.next, struct net2280_request, queue);
+
+	if (!use_dma_chaining) {
+		start_dma (ep, req);
+		return;
+	}
+
+	/* the 2280 will be processing the queue unless queue hiccups after
+	 * the previous transfer:
+	 *  IN:   wanted automagic zlp, head doesn't (or vice versa)
+	 *        DMA_FIFO_VALIDATE doesn't init from dma descriptors.
+	 *  OUT:  was "usb-short", we must restart.
+	 */
+	if (ep->is_in && !req->valid) {
+		struct net2280_request	*entry, *prev = NULL;
+		int			reqmode, done = 0;
+
+		DEBUG (ep->dev, "%s dma hiccup td %p\n", ep->ep.name, req->td);
+		ep->in_fifo_validate = likely (req->req.zero
+			|| (req->req.length % ep->ep.maxpacket) != 0);
+		if (ep->in_fifo_validate)
+			dmactl |= (1 << DMA_FIFO_VALIDATE);
+		list_for_each_entry (entry, &ep->queue, queue) {
+			__le32		dmacount;
+
+			if (entry == req)
+				continue;
+			dmacount = entry->td->dmacount;
+			if (!done) {
+				reqmode = likely (entry->req.zero
+					|| (entry->req.length
+						% ep->ep.maxpacket) != 0);
+				if (reqmode == ep->in_fifo_validate) {
+					entry->valid = 1;
+					dmacount |= valid_bit;
+					entry->td->dmacount = dmacount;
+					prev = entry;
+					continue;
+				} else {
+					/* force a hiccup */
+					prev->td->dmacount |= dma_done_ie;
+					done = 1;
+				}
+			}
+
+			/* walk the rest of the queue so unlinks behave */
+			entry->valid = 0;
+			dmacount &= ~valid_bit;
+			entry->td->dmacount = dmacount;
+			prev = entry;
+		}
+	}
+
+	writel (0, &ep->dma->dmactl);
+	start_queue (ep, dmactl, req->td_dma);
+}
+
+static void abort_dma (struct net2280_ep *ep)
+{
+	/* abort the current transfer */
+	if (likely (!list_empty (&ep->queue))) {
+		/* FIXME work around errata 0121, 0122, 0124 */
+		writel ((1 << DMA_ABORT), &ep->dma->dmastat);
+		spin_stop_dma (ep->dma);
+	} else
+		stop_dma (ep->dma);
+	scan_dma_completions (ep);
+}
+
+/* dequeue ALL requests */
+static void nuke (struct net2280_ep *ep)
+{
+	struct net2280_request	*req;
+
+	/* called with spinlock held */
+	ep->stopped = 1;
+	if (ep->dma)
+		abort_dma (ep);
+	while (!list_empty (&ep->queue)) {
+		req = list_entry (ep->queue.next,
+				struct net2280_request,
+				queue);
+		done (ep, req, -ESHUTDOWN);
+	}
+}
+
+/* dequeue JUST ONE request */
+static int net2280_dequeue (struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct net2280_ep	*ep;
+	struct net2280_request	*req;
+	unsigned long		flags;
+	u32			dmactl;
+	int			stopped;
+
+	ep = container_of (_ep, struct net2280_ep, ep);
+	if (!_ep || (!ep->desc && ep->num != 0) || !_req)
+		return -EINVAL;
+
+	spin_lock_irqsave (&ep->dev->lock, flags);
+	stopped = ep->stopped;
+
+	/* quiesce dma while we patch the queue */
+	dmactl = 0;
+	ep->stopped = 1;
+	if (ep->dma) {
+		dmactl = readl (&ep->dma->dmactl);
+		/* WARNING erratum 0127 may kick in ... */
+		stop_dma (ep->dma);
+		scan_dma_completions (ep);
+	}
+
+	/* 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) {
+		spin_unlock_irqrestore (&ep->dev->lock, flags);
+		return -EINVAL;
+	}
+
+	/* queue head may be partially complete. */
+	if (ep->queue.next == &req->queue) {
+		if (ep->dma) {
+			DEBUG (ep->dev, "unlink (%s) dma\n", _ep->name);
+			_req->status = -ECONNRESET;
+			abort_dma (ep);
+			if (likely (ep->queue.next == &req->queue)) {
+				// NOTE: misreports single-transfer mode
+				req->td->dmacount = 0;	/* invalidate */
+				dma_done (ep, req,
+					readl (&ep->dma->dmacount),
+					-ECONNRESET);
+			}
+		} else {
+			DEBUG (ep->dev, "unlink (%s) pio\n", _ep->name);
+			done (ep, req, -ECONNRESET);
+		}
+		req = NULL;
+
+	/* patch up hardware chaining data */
+	} else if (ep->dma && use_dma_chaining) {
+		if (req->queue.prev == ep->queue.next) {
+			writel (le32_to_cpu (req->td->dmadesc),
+				&ep->dma->dmadesc);
+			if (req->td->dmacount & dma_done_ie)
+				writel (readl (&ep->dma->dmacount)
+						| le32_to_cpu(dma_done_ie),
+					&ep->dma->dmacount);
+		} else {
+			struct net2280_request	*prev;
+
+			prev = list_entry (req->queue.prev,
+				struct net2280_request, queue);
+			prev->td->dmadesc = req->td->dmadesc;
+			if (req->td->dmacount & dma_done_ie)
+				prev->td->dmacount |= dma_done_ie;
+		}
+	}
+
+	if (req)
+		done (ep, req, -ECONNRESET);
+	ep->stopped = stopped;
+
+	if (ep->dma) {
+		/* turn off dma on inactive queues */
+		if (list_empty (&ep->queue))
+			stop_dma (ep->dma);
+		else if (!ep->stopped) {
+			/* resume current request, or start new one */
+			if (req)
+				writel (dmactl, &ep->dma->dmactl);
+			else
+				start_dma (ep, list_entry (ep->queue.next,
+					struct net2280_request, queue));
+		}
+	}
+
+	spin_unlock_irqrestore (&ep->dev->lock, flags);
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int net2280_fifo_status (struct usb_ep *_ep);
+
+static int
+net2280_set_halt (struct usb_ep *_ep, int value)
+{
+	struct net2280_ep	*ep;
+	unsigned long		flags;
+	int			retval = 0;
+
+	ep = container_of (_ep, struct net2280_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 */ && (ep->desc->bmAttributes & 0x03)
+						== USB_ENDPOINT_XFER_ISOC)
+		return -EINVAL;
+
+	spin_lock_irqsave (&ep->dev->lock, flags);
+	if (!list_empty (&ep->queue))
+		retval = -EAGAIN;
+	else if (ep->is_in && value && net2280_fifo_status (_ep) != 0)
+		retval = -EAGAIN;
+	else {
+		VDEBUG (ep->dev, "%s %s halt\n", _ep->name,
+				value ? "set" : "clear");
+		/* set/clear, then synch memory views with the device */
+		if (value) {
+			if (ep->num == 0)
+				ep->dev->protocol_stall = 1;
+			else
+				set_halt (ep);
+		} else
+			clear_halt (ep);
+		(void) readl (&ep->regs->ep_rsp);
+	}
+	spin_unlock_irqrestore (&ep->dev->lock, flags);
+
+	return retval;
+}
+
+static int
+net2280_fifo_status (struct usb_ep *_ep)
+{
+	struct net2280_ep	*ep;
+	u32			avail;
+
+	ep = container_of (_ep, struct net2280_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 = readl (&ep->regs->ep_avail) & ((1 << 12) - 1);
+	if (avail > ep->fifo_size)
+		return -EOVERFLOW;
+	if (ep->is_in)
+		avail = ep->fifo_size - avail;
+	return avail;
+}
+
+static void
+net2280_fifo_flush (struct usb_ep *_ep)
+{
+	struct net2280_ep	*ep;
+
+	ep = container_of (_ep, struct net2280_ep, ep);
+	if (!_ep || (!ep->desc && ep->num != 0))
+		return;
+	if (!ep->dev->driver || ep->dev->gadget.speed == USB_SPEED_UNKNOWN)
+		return;
+
+	writel ((1 << FIFO_FLUSH), &ep->regs->ep_stat);
+	(void) readl (&ep->regs->ep_rsp);
+}
+
+static const struct usb_ep_ops net2280_ep_ops = {
+	.enable		= net2280_enable,
+	.disable	= net2280_disable,
+
+	.alloc_request	= net2280_alloc_request,
+	.free_request	= net2280_free_request,
+
+	.alloc_buffer	= net2280_alloc_buffer,
+	.free_buffer	= net2280_free_buffer,
+
+	.queue		= net2280_queue,
+	.dequeue	= net2280_dequeue,
+
+	.set_halt	= net2280_set_halt,
+	.fifo_status	= net2280_fifo_status,
+	.fifo_flush	= net2280_fifo_flush,
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int net2280_get_frame (struct usb_gadget *_gadget)
+{
+	struct net2280		*dev;
+	unsigned long		flags;
+	u16			retval;
+
+	if (!_gadget)
+		return -ENODEV;
+	dev = container_of (_gadget, struct net2280, gadget);
+	spin_lock_irqsave (&dev->lock, flags);
+	retval = get_idx_reg (dev->regs, REG_FRAME) & 0x03ff;
+	spin_unlock_irqrestore (&dev->lock, flags);
+	return retval;
+}
+
+static int net2280_wakeup (struct usb_gadget *_gadget)
+{
+	struct net2280		*dev;
+	u32			tmp;
+	unsigned long		flags;
+
+	if (!_gadget)
+		return 0;
+	dev = container_of (_gadget, struct net2280, gadget);
+
+	spin_lock_irqsave (&dev->lock, flags);
+	tmp = readl (&dev->usb->usbctl);
+	if (tmp & (1 << DEVICE_REMOTE_WAKEUP_ENABLE))
+		writel (1 << GENERATE_RESUME, &dev->usb->usbstat);
+	spin_unlock_irqrestore (&dev->lock, flags);
+
+	/* pci writes may still be posted */
+	return 0;
+}
+
+static int net2280_set_selfpowered (struct usb_gadget *_gadget, int value)
+{
+	struct net2280		*dev;
+	u32			tmp;
+	unsigned long		flags;
+
+	if (!_gadget)
+		return 0;
+	dev = container_of (_gadget, struct net2280, gadget);
+
+	spin_lock_irqsave (&dev->lock, flags);
+	tmp = readl (&dev->usb->usbctl);
+	if (value)
+		tmp |= (1 << SELF_POWERED_STATUS);
+	else
+		tmp &= ~(1 << SELF_POWERED_STATUS);
+	writel (tmp, &dev->usb->usbctl);
+	spin_unlock_irqrestore (&dev->lock, flags);
+
+	return 0;
+}
+
+static int net2280_pullup(struct usb_gadget *_gadget, int is_on)
+{
+	struct net2280  *dev;
+	u32             tmp;
+	unsigned long   flags;
+
+	if (!_gadget)
+		return -ENODEV;
+	dev = container_of (_gadget, struct net2280, gadget);
+
+	spin_lock_irqsave (&dev->lock, flags);
+	tmp = readl (&dev->usb->usbctl);
+	dev->softconnect = (is_on != 0);
+	if (is_on)
+		tmp |= (1 << USB_DETECT_ENABLE);
+	else
+		tmp &= ~(1 << USB_DETECT_ENABLE);
+	writel (tmp, &dev->usb->usbctl);
+	spin_unlock_irqrestore (&dev->lock, flags);
+
+	return 0;
+}
+
+static const struct usb_gadget_ops net2280_ops = {
+	.get_frame	= net2280_get_frame,
+	.wakeup		= net2280_wakeup,
+	.set_selfpowered = net2280_set_selfpowered,
+	.pullup		= net2280_pullup,
+};
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef	CONFIG_USB_GADGET_DEBUG_FILES
+
+/* FIXME move these into procfs, and use seq_file.
+ * Sysfs _still_ doesn't behave for arbitrarily sized files,
+ * and also doesn't help products using this with 2.4 kernels.
+ */
+
+/* "function" sysfs attribute */
+static ssize_t
+show_function (struct device *_dev, struct device_attribute *attr, char *buf)
+{
+	struct net2280	*dev = dev_get_drvdata (_dev);
+
+	if (!dev->driver
+			|| !dev->driver->function
+			|| strlen (dev->driver->function) > PAGE_SIZE)
+		return 0;
+	return scnprintf (buf, PAGE_SIZE, "%s\n", dev->driver->function);
+}
+static DEVICE_ATTR (function, S_IRUGO, show_function, NULL);
+
+static ssize_t
+show_registers (struct device *_dev, struct device_attribute *attr, char *buf)
+{
+	struct net2280		*dev;
+	char			*next;
+	unsigned		size, t;
+	unsigned long		flags;
+	int			i;
+	u32			t1, t2;
+	const char		*s;
+
+	dev = dev_get_drvdata (_dev);
+	next = buf;
+	size = PAGE_SIZE;
+	spin_lock_irqsave (&dev->lock, flags);
+
+	if (dev->driver)
+		s = dev->driver->driver.name;
+	else
+		s = "(none)";
+
+	/* Main Control Registers */
+	t = scnprintf (next, size, "%s version " DRIVER_VERSION
+			", chiprev %04x, dma %s\n\n"
+			"devinit %03x fifoctl %08x gadget '%s'\n"
+			"pci irqenb0 %02x irqenb1 %08x "
+			"irqstat0 %04x irqstat1 %08x\n",
+			driver_name, dev->chiprev,
+			use_dma
+				? (use_dma_chaining ? "chaining" : "enabled")
+				: "disabled",
+			readl (&dev->regs->devinit),
+			readl (&dev->regs->fifoctl),
+			s,
+			readl (&dev->regs->pciirqenb0),
+			readl (&dev->regs->pciirqenb1),
+			readl (&dev->regs->irqstat0),
+			readl (&dev->regs->irqstat1));
+	size -= t;
+	next += t;
+
+	/* USB Control Registers */
+	t1 = readl (&dev->usb->usbctl);
+	t2 = readl (&dev->usb->usbstat);
+	if (t1 & (1 << VBUS_PIN)) {
+		if (t2 & (1 << HIGH_SPEED))
+			s = "high speed";
+		else if (dev->gadget.speed == USB_SPEED_UNKNOWN)
+			s = "powered";
+		else
+			s = "full speed";
+		/* full speed bit (6) not working?? */
+	} else
+			s = "not attached";
+	t = scnprintf (next, size,
+			"stdrsp %08x usbctl %08x usbstat %08x "
+				"addr 0x%02x (%s)\n",
+			readl (&dev->usb->stdrsp), t1, t2,
+			readl (&dev->usb->ouraddr), s);
+	size -= t;
+	next += t;
+
+	/* PCI Master Control Registers */
+
+	/* DMA Control Registers */
+
+	/* Configurable EP Control Registers */
+	for (i = 0; i < 7; i++) {
+		struct net2280_ep	*ep;
+
+		ep = &dev->ep [i];
+		if (i && !ep->desc)
+			continue;
+
+		t1 = readl (&ep->regs->ep_cfg);
+		t2 = readl (&ep->regs->ep_rsp) & 0xff;
+		t = scnprintf (next, size,
+				"\n%s\tcfg %05x rsp (%02x) %s%s%s%s%s%s%s%s"
+					"irqenb %02x\n",
+				ep->ep.name, t1, t2,
+				(t2 & (1 << CLEAR_NAK_OUT_PACKETS))
+					? "NAK " : "",
+				(t2 & (1 << CLEAR_EP_HIDE_STATUS_PHASE))
+					? "hide " : "",
+				(t2 & (1 << CLEAR_EP_FORCE_CRC_ERROR))
+					? "CRC " : "",
+				(t2 & (1 << CLEAR_INTERRUPT_MODE))
+					? "interrupt " : "",
+				(t2 & (1<<CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE))
+					? "status " : "",
+				(t2 & (1 << CLEAR_NAK_OUT_PACKETS_MODE))
+					? "NAKmode " : "",
+				(t2 & (1 << CLEAR_ENDPOINT_TOGGLE))
+					? "DATA1 " : "DATA0 ",
+				(t2 & (1 << CLEAR_ENDPOINT_HALT))
+					? "HALT " : "",
+				readl (&ep->regs->ep_irqenb));
+		size -= t;
+		next += t;
+
+		t = scnprintf (next, size,
+				"\tstat %08x avail %04x "
+				"(ep%d%s-%s)%s\n",
+				readl (&ep->regs->ep_stat),
+				readl (&ep->regs->ep_avail),
+				t1 & 0x0f, DIR_STRING (t1),
+				type_string (t1 >> 8),
+				ep->stopped ? "*" : "");
+		size -= t;
+		next += t;
+
+		if (!ep->dma)
+			continue;
+
+		t = scnprintf (next, size,
+				"  dma\tctl %08x stat %08x count %08x\n"
+				"\taddr %08x desc %08x\n",
+				readl (&ep->dma->dmactl),
+				readl (&ep->dma->dmastat),
+				readl (&ep->dma->dmacount),
+				readl (&ep->dma->dmaaddr),
+				readl (&ep->dma->dmadesc));
+		size -= t;
+		next += t;
+
+	}
+
+	/* Indexed Registers */
+		// none yet
+
+	/* Statistics */
+	t = scnprintf (next, size, "\nirqs:  ");
+	size -= t;
+	next += t;
+	for (i = 0; i < 7; i++) {
+		struct net2280_ep	*ep;
+
+		ep = &dev->ep [i];
+		if (i && !ep->irqs)
+			continue;
+		t = scnprintf (next, size, " %s/%lu", ep->ep.name, ep->irqs);
+		size -= t;
+		next += t;
+
+	}
+	t = scnprintf (next, size, "\n");
+	size -= t;
+	next += t;
+
+	spin_unlock_irqrestore (&dev->lock, flags);
+
+	return PAGE_SIZE - size;
+}
+static DEVICE_ATTR (registers, S_IRUGO, show_registers, NULL);
+
+static ssize_t
+show_queues (struct device *_dev, struct device_attribute *attr, char *buf)
+{
+	struct net2280		*dev;
+	char			*next;
+	unsigned		size;
+	unsigned long		flags;
+	int			i;
+
+	dev = dev_get_drvdata (_dev);
+	next = buf;
+	size = PAGE_SIZE;
+	spin_lock_irqsave (&dev->lock, flags);
+
+	for (i = 0; i < 7; i++) {
+		struct net2280_ep		*ep = &dev->ep [i];
+		struct net2280_request		*req;
+		int				t;
+
+		if (i != 0) {
+			const struct usb_endpoint_descriptor	*d;
+
+			d = ep->desc;
+			if (!d)
+				continue;
+			t = d->bEndpointAddress;
+			t = scnprintf (next, size,
+				"\n%s (ep%d%s-%s) max %04x %s fifo %d\n",
+				ep->ep.name, t & USB_ENDPOINT_NUMBER_MASK,
+				(t & USB_DIR_IN) ? "in" : "out",
+				({ char *val;
+				 switch (d->bmAttributes & 0x03) {
+				 case USB_ENDPOINT_XFER_BULK:
+					val = "bulk"; break;
+				 case USB_ENDPOINT_XFER_INT:
+					val = "intr"; break;
+				 default:
+					val = "iso"; break;
+				 }; val; }),
+				le16_to_cpu (d->wMaxPacketSize) & 0x1fff,
+				ep->dma ? "dma" : "pio", ep->fifo_size
+				);
+		} else /* ep0 should only have one transfer queued */
+			t = scnprintf (next, size, "ep0 max 64 pio %s\n",
+					ep->is_in ? "in" : "out");
+		if (t <= 0 || t > size)
+			goto done;
+		size -= t;
+		next += t;
+
+		if (list_empty (&ep->queue)) {
+			t = scnprintf (next, size, "\t(nothing queued)\n");
+			if (t <= 0 || t > size)
+				goto done;
+			size -= t;
+			next += t;
+			continue;
+		}
+		list_for_each_entry (req, &ep->queue, queue) {
+			if (ep->dma && req->td_dma == readl (&ep->dma->dmadesc))
+				t = scnprintf (next, size,
+					"\treq %p len %d/%d "
+					"buf %p (dmacount %08x)\n",
+					&req->req, req->req.actual,
+					req->req.length, req->req.buf,
+					readl (&ep->dma->dmacount));
+			else
+				t = scnprintf (next, size,
+					"\treq %p len %d/%d buf %p\n",
+					&req->req, req->req.actual,
+					req->req.length, req->req.buf);
+			if (t <= 0 || t > size)
+				goto done;
+			size -= t;
+			next += t;
+
+			if (ep->dma) {
+				struct net2280_dma	*td;
+
+				td = req->td;
+				t = scnprintf (next, size, "\t    td %08x "
+					" count %08x buf %08x desc %08x\n",
+					(u32) req->td_dma,
+					le32_to_cpu (td->dmacount),
+					le32_to_cpu (td->dmaaddr),
+					le32_to_cpu (td->dmadesc));
+				if (t <= 0 || t > size)
+					goto done;
+				size -= t;
+				next += t;
+			}
+		}
+	}
+
+done:
+	spin_unlock_irqrestore (&dev->lock, flags);
+	return PAGE_SIZE - size;
+}
+static DEVICE_ATTR (queues, S_IRUGO, show_queues, NULL);
+
+
+#else
+
+#define device_create_file(a,b)	(0)
+#define device_remove_file(a,b)	do { } while (0)
+
+#endif
+
+/*-------------------------------------------------------------------------*/
+
+/* another driver-specific mode might be a request type doing dma
+ * to/from another device fifo instead of to/from memory.
+ */
+
+static void set_fifo_mode (struct net2280 *dev, int mode)
+{
+	/* keeping high bits preserves BAR2 */
+	writel ((0xffff << PCI_BASE2_RANGE) | mode, &dev->regs->fifoctl);
+
+	/* always ep-{a,b,e,f} ... maybe not ep-c or ep-d */
+	INIT_LIST_HEAD (&dev->gadget.ep_list);
+	list_add_tail (&dev->ep [1].ep.ep_list, &dev->gadget.ep_list);
+	list_add_tail (&dev->ep [2].ep.ep_list, &dev->gadget.ep_list);
+	switch (mode) {
+	case 0:
+		list_add_tail (&dev->ep [3].ep.ep_list, &dev->gadget.ep_list);
+		list_add_tail (&dev->ep [4].ep.ep_list, &dev->gadget.ep_list);
+		dev->ep [1].fifo_size = dev->ep [2].fifo_size = 1024;
+		break;
+	case 1:
+		dev->ep [1].fifo_size = dev->ep [2].fifo_size = 2048;
+		break;
+	case 2:
+		list_add_tail (&dev->ep [3].ep.ep_list, &dev->gadget.ep_list);
+		dev->ep [1].fifo_size = 2048;
+		dev->ep [2].fifo_size = 1024;
+		break;
+	}
+	/* fifo sizes for ep0, ep-c, ep-d, ep-e, and ep-f never change */
+	list_add_tail (&dev->ep [5].ep.ep_list, &dev->gadget.ep_list);
+	list_add_tail (&dev->ep [6].ep.ep_list, &dev->gadget.ep_list);
+}
+
+/* just declare this in any driver that really need it */
+extern int net2280_set_fifo_mode (struct usb_gadget *gadget, int mode);
+
+/**
+ * net2280_set_fifo_mode - change allocation of fifo buffers
+ * @gadget: access to the net2280 device that will be updated
+ * @mode: 0 for default, four 1kB buffers (ep-a through ep-d);
+ *	1 for two 2kB buffers (ep-a and ep-b only);
+ *	2 for one 2kB buffer (ep-a) and two 1kB ones (ep-b, ep-c).
+ *
+ * returns zero on success, else negative errno.  when this succeeds,
+ * the contents of gadget->ep_list may have changed.
+ *
+ * you may only call this function when endpoints a-d are all disabled.
+ * use it whenever extra hardware buffering can help performance, such
+ * as before enabling "high bandwidth" interrupt endpoints that use
+ * maxpacket bigger than 512 (when double buffering would otherwise
+ * be unavailable).
+ */
+int net2280_set_fifo_mode (struct usb_gadget *gadget, int mode)
+{
+	int			i;
+	struct net2280		*dev;
+	int			status = 0;
+	unsigned long		flags;
+
+	if (!gadget)
+		return -ENODEV;
+	dev = container_of (gadget, struct net2280, gadget);
+
+	spin_lock_irqsave (&dev->lock, flags);
+
+	for (i = 1; i <= 4; i++)
+		if (dev->ep [i].desc) {
+			status = -EINVAL;
+			break;
+		}
+	if (mode < 0 || mode > 2)
+		status = -EINVAL;
+	if (status == 0)
+		set_fifo_mode (dev, mode);
+	spin_unlock_irqrestore (&dev->lock, flags);
+
+	if (status == 0) {
+		if (mode == 1)
+			DEBUG (dev, "fifo:  ep-a 2K, ep-b 2K\n");
+		else if (mode == 2)
+			DEBUG (dev, "fifo:  ep-a 2K, ep-b 1K, ep-c 1K\n");
+		/* else all are 1K */
+	}
+	return status;
+}
+EXPORT_SYMBOL (net2280_set_fifo_mode);
+
+/*-------------------------------------------------------------------------*/
+
+/* keeping it simple:
+ * - one bus driver, initted first;
+ * - one function driver, initted second
+ *
+ * most of the work to support multiple net2280 controllers would
+ * be to associate this gadget driver (yes?) with all of them, or
+ * perhaps to bind specific drivers to specific devices.
+ */
+
+static struct net2280	*the_controller;
+
+static void usb_reset (struct net2280 *dev)
+{
+	u32	tmp;
+
+	dev->gadget.speed = USB_SPEED_UNKNOWN;
+	(void) readl (&dev->usb->usbctl);
+
+	net2280_led_init (dev);
+
+	/* disable automatic responses, and irqs */
+	writel (0, &dev->usb->stdrsp);
+	writel (0, &dev->regs->pciirqenb0);
+	writel (0, &dev->regs->pciirqenb1);
+
+	/* clear old dma and irq state */
+	for (tmp = 0; tmp < 4; tmp++) {
+		struct net2280_ep	*ep = &dev->ep [tmp + 1];
+
+		if (ep->dma)
+			abort_dma (ep);
+	}
+	writel (~0, &dev->regs->irqstat0),
+	writel (~(1 << SUSPEND_REQUEST_INTERRUPT), &dev->regs->irqstat1),
+
+	/* reset, and enable pci */
+	tmp = readl (&dev->regs->devinit)
+		| (1 << PCI_ENABLE)
+		| (1 << FIFO_SOFT_RESET)
+		| (1 << USB_SOFT_RESET)
+		| (1 << M8051_RESET);
+	writel (tmp, &dev->regs->devinit);
+
+	/* standard fifo and endpoint allocations */
+	set_fifo_mode (dev, (fifo_mode <= 2) ? fifo_mode : 0);
+}
+
+static void usb_reinit (struct net2280 *dev)
+{
+	u32	tmp;
+	int	init_dma;
+
+	/* use_dma changes are ignored till next device re-init */
+	init_dma = use_dma;
+
+	/* basic endpoint init */
+	for (tmp = 0; tmp < 7; tmp++) {
+		struct net2280_ep	*ep = &dev->ep [tmp];
+
+		ep->ep.name = ep_name [tmp];
+		ep->dev = dev;
+		ep->num = tmp;
+
+		if (tmp > 0 && tmp <= 4) {
+			ep->fifo_size = 1024;
+			if (init_dma)
+				ep->dma = &dev->dma [tmp - 1];
+		} else
+			ep->fifo_size = 64;
+		ep->regs = &dev->epregs [tmp];
+		ep_reset (dev->regs, ep);
+	}
+	dev->ep [0].ep.maxpacket = 64;
+	dev->ep [5].ep.maxpacket = 64;
+	dev->ep [6].ep.maxpacket = 64;
+
+	dev->gadget.ep0 = &dev->ep [0].ep;
+	dev->ep [0].stopped = 0;
+	INIT_LIST_HEAD (&dev->gadget.ep0->ep_list);
+
+	/* we want to prevent lowlevel/insecure access from the USB host,
+	 * but erratum 0119 means this enable bit is ignored
+	 */
+	for (tmp = 0; tmp < 5; tmp++)
+		writel (EP_DONTUSE, &dev->dep [tmp].dep_cfg);
+}
+
+static void ep0_start (struct net2280 *dev)
+{
+	writel (  (1 << CLEAR_EP_HIDE_STATUS_PHASE)
+		| (1 << CLEAR_NAK_OUT_PACKETS)
+		| (1 << CLEAR_CONTROL_STATUS_PHASE_HANDSHAKE)
+		, &dev->epregs [0].ep_rsp);
+
+	/*
+	 * hardware optionally handles a bunch of standard requests
+	 * that the API hides from drivers anyway.  have it do so.
+	 * endpoint status/features are handled in software, to
+	 * help pass tests for some dubious behavior.
+	 */
+	writel (  (1 << SET_TEST_MODE)
+		| (1 << SET_ADDRESS)
+		| (1 << DEVICE_SET_CLEAR_DEVICE_REMOTE_WAKEUP)
+		| (1 << GET_DEVICE_STATUS)
+		| (1 << GET_INTERFACE_STATUS)
+		, &dev->usb->stdrsp);
+	writel (  (1 << USB_ROOT_PORT_WAKEUP_ENABLE)
+		| (1 << SELF_POWERED_USB_DEVICE)
+		| (1 << REMOTE_WAKEUP_SUPPORT)
+		| (dev->softconnect << USB_DETECT_ENABLE)
+		| (1 << SELF_POWERED_STATUS)
+		, &dev->usb->usbctl);
+
+	/* enable irqs so we can see ep0 and general operation  */
+	writel (  (1 << SETUP_PACKET_INTERRUPT_ENABLE)
+		| (1 << ENDPOINT_0_INTERRUPT_ENABLE)
+		, &dev->regs->pciirqenb0);
+	writel (  (1 << PCI_INTERRUPT_ENABLE)
+		| (1 << PCI_MASTER_ABORT_RECEIVED_INTERRUPT_ENABLE)
+		| (1 << PCI_TARGET_ABORT_RECEIVED_INTERRUPT_ENABLE)
+		| (1 << PCI_RETRY_ABORT_INTERRUPT_ENABLE)
+		| (1 << VBUS_INTERRUPT_ENABLE)
+		| (1 << ROOT_PORT_RESET_INTERRUPT_ENABLE)
+		| (1 << SUSPEND_REQUEST_CHANGE_INTERRUPT_ENABLE)
+		, &dev->regs->pciirqenb1);
+
+	/* don't leave any writes posted */
+	(void) readl (&dev->usb->usbctl);
+}
+
+/* when a driver is successfully registered, it will receive
+ * control requests including set_configuration(), which enables
+ * non-control requests.  then usb traffic follows until a
+ * disconnect is reported.  then a host may connect again, or
+ * the driver might get unbound.
+ */
+int usb_gadget_register_driver (struct usb_gadget_driver *driver)
+{
+	struct net2280		*dev = the_controller;
+	int			retval;
+	unsigned		i;
+
+	/* insist on high speed support from the driver, since
+	 * (dev->usb->xcvrdiag & FORCE_FULL_SPEED_MODE)
+	 * "must not be used in normal operation"
+	 */
+	if (!driver
+			|| driver->speed != USB_SPEED_HIGH
+			|| !driver->bind
+			|| !driver->unbind
+			|| !driver->setup)
+		return -EINVAL;
+	if (!dev)
+		return -ENODEV;
+	if (dev->driver)
+		return -EBUSY;
+
+	for (i = 0; i < 7; i++)
+		dev->ep [i].irqs = 0;
+
+	/* hook up the driver ... */
+	dev->softconnect = 1;
+	driver->driver.bus = NULL;
+	dev->driver = driver;
+	dev->gadget.dev.driver = &driver->driver;
+	retval = driver->bind (&dev->gadget);
+	if (retval) {
+		DEBUG (dev, "bind to driver %s --> %d\n",
+				driver->driver.name, retval);
+		dev->driver = NULL;
+		dev->gadget.dev.driver = NULL;
+		return retval;
+	}
+
+	retval = device_create_file (&dev->pdev->dev, &dev_attr_function);
+	if (retval) goto err_unbind;
+	retval = device_create_file (&dev->pdev->dev, &dev_attr_queues);
+	if (retval) goto err_func;
+
+	/* ... then enable host detection and ep0; and we're ready
+	 * for set_configuration as well as eventual disconnect.
+	 */
+	net2280_led_active (dev, 1);
+	ep0_start (dev);
+
+	DEBUG (dev, "%s ready, usbctl %08x stdrsp %08x\n",
+			driver->driver.name,
+			readl (&dev->usb->usbctl),
+			readl (&dev->usb->stdrsp));
+
+	/* pci writes may still be posted */
+	return 0;
+
+err_func:
+	device_remove_file (&dev->pdev->dev, &dev_attr_function);
+err_unbind:
+	driver->unbind (&dev->gadget);
+	dev->gadget.dev.driver = NULL;
+	dev->driver = NULL;
+	return retval;
+}
+EXPORT_SYMBOL (usb_gadget_register_driver);
+
+static void
+stop_activity (struct net2280 *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.
+	 */
+	usb_reset (dev);
+	for (i = 0; i < 7; i++)
+		nuke (&dev->ep [i]);
+
+	/* report disconnect; the driver is already quiesced */
+	if (driver) {
+		spin_unlock (&dev->lock);
+		driver->disconnect (&dev->gadget);
+		spin_lock (&dev->lock);
+	}
+
+	usb_reinit (dev);
+}
+
+int usb_gadget_unregister_driver (struct usb_gadget_driver *driver)
+{
+	struct net2280	*dev = the_controller;
+	unsigned long	flags;
+
+	if (!dev)
+		return -ENODEV;
+	if (!driver || driver != dev->driver)
+		return -EINVAL;
+
+	spin_lock_irqsave (&dev->lock, flags);
+	stop_activity (dev, driver);
+	spin_unlock_irqrestore (&dev->lock, flags);
+
+	net2280_pullup (&dev->gadget, 0);
+
+	driver->unbind (&dev->gadget);
+	dev->gadget.dev.driver = NULL;
+	dev->driver = NULL;
+
+	net2280_led_active (dev, 0);
+	device_remove_file (&dev->pdev->dev, &dev_attr_function);
+	device_remove_file (&dev->pdev->dev, &dev_attr_queues);
+
+	DEBUG (dev, "unregistered driver '%s'\n", driver->driver.name);
+	return 0;
+}
+EXPORT_SYMBOL (usb_gadget_unregister_driver);
+
+
+/*-------------------------------------------------------------------------*/
+
+/* handle ep0, ep-e, ep-f with 64 byte packets: packet per irq.
+ * also works for dma-capable endpoints, in pio mode or just
+ * to manually advance the queue after short OUT transfers.
+ */
+static void handle_ep_small (struct net2280_ep *ep)
+{
+	struct net2280_request	*req;
+	u32			t;
+	/* 0 error, 1 mid-data, 2 done */
+	int			mode = 1;
+
+	if (!list_empty (&ep->queue))
+		req = list_entry (ep->queue.next,
+			struct net2280_request, queue);
+	else
+		req = NULL;
+
+	/* ack all, and handle what we care about */
+	t = readl (&ep->regs->ep_stat);
+	ep->irqs++;
+#if 0
+	VDEBUG (ep->dev, "%s ack ep_stat %08x, req %p\n",
+			ep->ep.name, t, req ? &req->req : 0);
+#endif
+	if (!ep->is_in || ep->dev->pdev->device == 0x2280)
+		writel (t & ~(1 << NAK_OUT_PACKETS), &ep->regs->ep_stat);
+	else
+		/* Added for 2282 */
+		writel (t, &ep->regs->ep_stat);
+
+	/* for ep0, monitor token irqs to catch data stage length errors
+	 * and to synchronize on status.
+	 *
+	 * also, to defer reporting of protocol stalls ... here's where
+	 * data or status first appears, handling stalls here should never
+	 * cause trouble on the host side..
+	 *
+	 * control requests could be slightly faster without token synch for
+	 * status, but status can jam up that way.
+	 */
+	if (unlikely (ep->num == 0)) {
+		if (ep->is_in) {
+			/* status; stop NAKing */
+			if (t & (1 << DATA_OUT_PING_TOKEN_INTERRUPT)) {
+				if (ep->dev->protocol_stall) {
+					ep->stopped = 1;
+					set_halt (ep);
+				}
+				if (!req)
+					allow_status (ep);
+				mode = 2;
+			/* reply to extra IN data tokens with a zlp */
+			} else if (t & (1 << DATA_IN_TOKEN_INTERRUPT)) {
+				if (ep->dev->protocol_stall) {
+					ep->stopped = 1;
+					set_halt (ep);
+					mode = 2;
+				} else if (!req && !ep->stopped)
+					write_fifo (ep, NULL);
+			}
+		} else {
+			/* status; stop NAKing */
+			if (t & (1 << DATA_IN_TOKEN_INTERRUPT)) {
+				if (ep->dev->protocol_stall) {
+					ep->stopped = 1;
+					set_halt (ep);
+				}
+				mode = 2;
+			/* an extra OUT token is an error */
+			} else if (((t & (1 << DATA_OUT_PING_TOKEN_INTERRUPT))
+					&& req
+					&& req->req.actual == req->req.length)
+					|| !req) {
+				ep->dev->protocol_stall = 1;
+				set_halt (ep);
+				ep->stopped = 1;
+				if (req)
+					done (ep, req, -EOVERFLOW);
+				req = NULL;
+			}
+		}
+	}
+
+	if (unlikely (!req))
+		return;
+
+	/* manual DMA queue advance after short OUT */
+	if (likely (ep->dma != 0)) {
+		if (t & (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)) {
+			u32	count;
+			int	stopped = ep->stopped;
+
+			/* TRANSFERRED works around OUT_DONE erratum 0112.
+			 * we expect (N <= maxpacket) bytes; host wrote M.
+			 * iff (M < N) we won't ever see a DMA interrupt.
+			 */
+			ep->stopped = 1;
+			for (count = 0; ; t = readl (&ep->regs->ep_stat)) {
+
+				/* any preceding dma transfers must finish.
+				 * dma handles (M >= N), may empty the queue
+				 */
+				scan_dma_completions (ep);
+				if (unlikely (list_empty (&ep->queue)
+						|| ep->out_overflow)) {
+					req = NULL;
+					break;
+				}
+				req = list_entry (ep->queue.next,
+					struct net2280_request, queue);
+
+				/* here either (M < N), a "real" short rx;
+				 * or (M == N) and the queue didn't empty
+				 */
+				if (likely (t & (1 << FIFO_EMPTY))) {
+					count = readl (&ep->dma->dmacount);
+					count &= DMA_BYTE_COUNT_MASK;
+					if (readl (&ep->dma->dmadesc)
+							!= req->td_dma)
+						req = NULL;
+					break;
+				}
+				udelay(1);
+			}
+
+			/* stop DMA, leave ep NAKing */
+			writel ((1 << DMA_ABORT), &ep->dma->dmastat);
+			spin_stop_dma (ep->dma);
+
+			if (likely (req)) {
+				req->td->dmacount = 0;
+				t = readl (&ep->regs->ep_avail);
+				dma_done (ep, req, count,
+					(ep->out_overflow || t)
+						? -EOVERFLOW : 0);
+			}
+
+			/* also flush to prevent erratum 0106 trouble */
+			if (unlikely (ep->out_overflow
+					|| (ep->dev->chiprev == 0x0100
+						&& ep->dev->gadget.speed
+							== USB_SPEED_FULL))) {
+				out_flush (ep);
+				ep->out_overflow = 0;
+			}
+
+			/* (re)start dma if needed, stop NAKing */
+			ep->stopped = stopped;
+			if (!list_empty (&ep->queue))
+				restart_dma (ep);
+		} else
+			DEBUG (ep->dev, "%s dma ep_stat %08x ??\n",
+					ep->ep.name, t);
+		return;
+
+	/* data packet(s) received (in the fifo, OUT) */
+	} else if (t & (1 << DATA_PACKET_RECEIVED_INTERRUPT)) {
+		if (read_fifo (ep, req) && ep->num != 0)
+			mode = 2;
+
+	/* data packet(s) transmitted (IN) */
+	} else if (t & (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)) {
+		unsigned	len;
+
+		len = req->req.length - req->req.actual;
+		if (len > ep->ep.maxpacket)
+			len = ep->ep.maxpacket;
+		req->req.actual += len;
+
+		/* if we wrote it all, we're usually done */
+		if (req->req.actual == req->req.length) {
+			if (ep->num == 0) {
+				/* send zlps until the status stage */
+			} else if (!req->req.zero || len != ep->ep.maxpacket)
+				mode = 2;
+		}
+
+	/* there was nothing to do ...  */
+	} else if (mode == 1)
+		return;
+
+	/* done */
+	if (mode == 2) {
+		/* stream endpoints often resubmit/unlink in completion */
+		done (ep, req, 0);
+
+		/* maybe advance queue to next request */
+		if (ep->num == 0) {
+			/* NOTE:  net2280 could let gadget driver start the
+			 * status stage later. since not all controllers let
+			 * them control that, the api doesn't (yet) allow it.
+			 */
+			if (!ep->stopped)
+				allow_status (ep);
+			req = NULL;
+		} else {
+			if (!list_empty (&ep->queue) && !ep->stopped)
+				req = list_entry (ep->queue.next,
+					struct net2280_request, queue);
+			else
+				req = NULL;
+			if (req && !ep->is_in)
+				stop_out_naking (ep);
+		}
+	}
+
+	/* is there a buffer for the next packet?
+	 * for best streaming performance, make sure there is one.
+	 */
+	if (req && !ep->stopped) {
+
+		/* load IN fifo with next packet (may be zlp) */
+		if (t & (1 << DATA_PACKET_TRANSMITTED_INTERRUPT))
+			write_fifo (ep, &req->req);
+	}
+}
+
+static struct net2280_ep *
+get_ep_by_addr (struct net2280 *dev, u16 wIndex)
+{
+	struct net2280_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;
+}
+
+static void handle_stat0_irqs (struct net2280 *dev, u32 stat)
+{
+	struct net2280_ep	*ep;
+	u32			num, scratch;
+
+	/* most of these don't need individual acks */
+	stat &= ~(1 << INTA_ASSERTED);
+	if (!stat)
+		return;
+	// DEBUG (dev, "irqstat0 %04x\n", stat);
+
+	/* starting a control request? */
+	if (unlikely (stat & (1 << SETUP_PACKET_INTERRUPT))) {
+		union {
+			u32			raw [2];
+			struct usb_ctrlrequest	r;
+		} u;
+		int				tmp;
+		struct net2280_request		*req;
+
+		if (dev->gadget.speed == USB_SPEED_UNKNOWN) {
+			if (readl (&dev->usb->usbstat) & (1 << HIGH_SPEED))
+				dev->gadget.speed = USB_SPEED_HIGH;
+			else
+				dev->gadget.speed = USB_SPEED_FULL;
+			net2280_led_speed (dev, dev->gadget.speed);
+			DEBUG (dev, "%s speed\n",
+				(dev->gadget.speed == USB_SPEED_HIGH)
+					? "high" : "full");
+		}
+
+		ep = &dev->ep [0];
+		ep->irqs++;
+
+		/* make sure any leftover request state is cleared */
+		stat &= ~(1 << ENDPOINT_0_INTERRUPT);
+		while (!list_empty (&ep->queue)) {
+			req = list_entry (ep->queue.next,
+					struct net2280_request, queue);
+			done (ep, req, (req->req.actual == req->req.length)
+						? 0 : -EPROTO);
+		}
+		ep->stopped = 0;
+		dev->protocol_stall = 0;
+
+		if (ep->dev->pdev->device == 0x2280)
+			tmp = (1 << FIFO_OVERFLOW)
+				| (1 << FIFO_UNDERFLOW);
+		else
+			tmp = 0;
+
+		writel (tmp | (1 << TIMEOUT)
+			| (1 << USB_STALL_SENT)
+			| (1 << USB_IN_NAK_SENT)
+			| (1 << USB_IN_ACK_RCVD)
+			| (1 << USB_OUT_PING_NAK_SENT)
+			| (1 << USB_OUT_ACK_SENT)
+			| (1 << SHORT_PACKET_OUT_DONE_INTERRUPT)
+			| (1 << SHORT_PACKET_TRANSFERRED_INTERRUPT)
+			| (1 << DATA_PACKET_RECEIVED_INTERRUPT)
+			| (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
+			| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
+			| (1 << DATA_IN_TOKEN_INTERRUPT)
+			, &ep->regs->ep_stat);
+		u.raw [0] = readl (&dev->usb->setup0123);
+		u.raw [1] = readl (&dev->usb->setup4567);
+
+		cpu_to_le32s (&u.raw [0]);
+		cpu_to_le32s (&u.raw [1]);
+
+		tmp = 0;
+
+#define	w_value		le16_to_cpup (&u.r.wValue)
+#define	w_index		le16_to_cpup (&u.r.wIndex)
+#define	w_length	le16_to_cpup (&u.r.wLength)
+
+		/* ack the irq */
+		writel (1 << SETUP_PACKET_INTERRUPT, &dev->regs->irqstat0);
+		stat ^= (1 << SETUP_PACKET_INTERRUPT);
+
+		/* watch control traffic at the token level, and force
+		 * synchronization before letting the status stage happen.
+		 * FIXME ignore tokens we'll NAK, until driver responds.
+		 * that'll mean a lot less irqs for some drivers.
+		 */
+		ep->is_in = (u.r.bRequestType & USB_DIR_IN) != 0;
+		if (ep->is_in) {
+			scratch = (1 << DATA_PACKET_TRANSMITTED_INTERRUPT)
+				| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
+				| (1 << DATA_IN_TOKEN_INTERRUPT);
+			stop_out_naking (ep);
+		} else
+			scratch = (1 << DATA_PACKET_RECEIVED_INTERRUPT)
+				| (1 << DATA_OUT_PING_TOKEN_INTERRUPT)
+				| (1 << DATA_IN_TOKEN_INTERRUPT);
+		writel (scratch, &dev->epregs [0].ep_irqenb);
+
+		/* we made the hardware handle most lowlevel requests;
+		 * everything else goes uplevel to the gadget code.
+		 */
+		switch (u.r.bRequest) {
+		case USB_REQ_GET_STATUS: {
+			struct net2280_ep	*e;
+			__le32			status;
+
+			/* hw handles device and interface status */
+			if (u.r.bRequestType != (USB_DIR_IN|USB_RECIP_ENDPOINT))
+				goto delegate;
+			if ((e = get_ep_by_addr (dev, w_index)) == 0
+					|| w_length > 2)
+				goto do_stall;
+
+			if (readl (&e->regs->ep_rsp)
+					& (1 << SET_ENDPOINT_HALT))
+				status = __constant_cpu_to_le32 (1);
+			else
+				status = __constant_cpu_to_le32 (0);
+
+			/* don't bother with a request object! */
+			writel (0, &dev->epregs [0].ep_irqenb);
+			set_fifo_bytecount (ep, w_length);
+			writel ((__force u32)status, &dev->epregs [0].ep_data);
+			allow_status (ep);
+			VDEBUG (dev, "%s stat %02x\n", ep->ep.name, status);
+			goto next_endpoints;
+			}
+			break;
+		case USB_REQ_CLEAR_FEATURE: {
+			struct net2280_ep	*e;
+
+			/* hw handles device features */
+			if (u.r.bRequestType != USB_RECIP_ENDPOINT)
+				goto delegate;
+			if (w_value != USB_ENDPOINT_HALT
+					|| w_length != 0)
+				goto do_stall;
+			if ((e = get_ep_by_addr (dev, w_index)) == 0)
+				goto do_stall;
+			clear_halt (e);
+			allow_status (ep);
+			VDEBUG (dev, "%s clear halt\n", ep->ep.name);
+			goto next_endpoints;
+			}
+			break;
+		case USB_REQ_SET_FEATURE: {
+			struct net2280_ep	*e;
+
+			/* hw handles device features */
+			if (u.r.bRequestType != USB_RECIP_ENDPOINT)
+				goto delegate;
+			if (w_value != USB_ENDPOINT_HALT
+					|| w_length != 0)
+				goto do_stall;
+			if ((e = get_ep_by_addr (dev, w_index)) == 0)
+				goto do_stall;
+			set_halt (e);
+			allow_status (ep);
+			VDEBUG (dev, "%s set halt\n", ep->ep.name);
+			goto next_endpoints;
+			}
+			break;
+		default:
+delegate:
+			VDEBUG (dev, "setup %02x.%02x v%04x i%04x l%04x"
+				"ep_cfg %08x\n",
+				u.r.bRequestType, u.r.bRequest,
+				w_value, w_index, w_length,
+				readl (&ep->regs->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:
+			VDEBUG (dev, "req %02x.%02x protocol STALL; stat %d\n",
+					u.r.bRequestType, u.r.bRequest, tmp);
+			dev->protocol_stall = 1;
+		}
+
+		/* some in/out token irq should follow; maybe stall then.
+		 * driver must queue a request (even zlp) or halt ep0
+		 * before the host times out.
+		 */
+	}
+
+#undef	w_value
+#undef	w_index
+#undef	w_length
+
+next_endpoints:
+	/* endpoint data irq ? */
+	scratch = stat & 0x7f;
+	stat &= ~0x7f;
+	for (num = 0; scratch; num++) {
+		u32		t;
+
+		/* do this endpoint's FIFO and queue need tending? */
+		t = 1 << num;
+		if ((scratch & t) == 0)
+			continue;
+		scratch ^= t;
+
+		ep = &dev->ep [num];
+		handle_ep_small (ep);
+	}
+
+	if (stat)
+		DEBUG (dev, "unhandled irqstat0 %08x\n", stat);
+}
+
+#define DMA_INTERRUPTS ( \
+		  (1 << DMA_D_INTERRUPT) \
+		| (1 << DMA_C_INTERRUPT) \
+		| (1 << DMA_B_INTERRUPT) \
+		| (1 << DMA_A_INTERRUPT))
+#define	PCI_ERROR_INTERRUPTS ( \
+		  (1 << PCI_MASTER_ABORT_RECEIVED_INTERRUPT) \
+		| (1 << PCI_TARGET_ABORT_RECEIVED_INTERRUPT) \
+		| (1 << PCI_RETRY_ABORT_INTERRUPT))
+
+static void handle_stat1_irqs (struct net2280 *dev, u32 stat)
+{
+	struct net2280_ep	*ep;
+	u32			tmp, num, mask, scratch;
+
+	/* after disconnect there's nothing else to do! */
+	tmp = (1 << VBUS_INTERRUPT) | (1 << ROOT_PORT_RESET_INTERRUPT);
+	mask = (1 << HIGH_SPEED) | (1 << FULL_SPEED);
+
+	/* VBUS disconnect is indicated by VBUS_PIN and VBUS_INTERRUPT set.
+	 * Root Port Reset is indicated by ROOT_PORT_RESET_INTERRRUPT set and
+	 * both HIGH_SPEED and FULL_SPEED clear (as ROOT_PORT_RESET_INTERRUPT
+	 * only indicates a change in the reset state).
+	 */
+	if (stat & tmp) {
+		writel (tmp, &dev->regs->irqstat1);
+		if ((((stat & (1 << ROOT_PORT_RESET_INTERRUPT))
+					&& ((readl (&dev->usb->usbstat) & mask)
+							== 0))
+				|| ((readl (&dev->usb->usbctl)
+					& (1 << VBUS_PIN)) == 0)
+			    ) && ( dev->gadget.speed != USB_SPEED_UNKNOWN)) {
+			DEBUG (dev, "disconnect %s\n",
+					dev->driver->driver.name);
+			stop_activity (dev, dev->driver);
+			ep0_start (dev);
+			return;
+		}
+		stat &= ~tmp;
+
+		/* vBUS can bounce ... one of many reasons to ignore the
+		 * notion of hotplug events on bus connect/disconnect!
+		 */
+		if (!stat)
+			return;
+	}
+
+	/* NOTE: chip stays in PCI D0 state for now, but it could
+	 * enter D1 to save more power
+	 */
+	tmp = (1 << SUSPEND_REQUEST_CHANGE_INTERRUPT);
+	if (stat & tmp) {
+		writel (tmp, &dev->regs->irqstat1);
+		if (stat & (1 << SUSPEND_REQUEST_INTERRUPT)) {
+			if (dev->driver->suspend)
+				dev->driver->suspend (&dev->gadget);
+			if (!enable_suspend)
+				stat &= ~(1 << SUSPEND_REQUEST_INTERRUPT);
+		} else {
+			if (dev->driver->resume)
+				dev->driver->resume (&dev->gadget);
+			/* at high speed, note erratum 0133 */
+		}
+		stat &= ~tmp;
+	}
+
+	/* clear any other status/irqs */
+	if (stat)
+		writel (stat, &dev->regs->irqstat1);
+
+	/* some status we can just ignore */
+	if (dev->pdev->device == 0x2280)
+		stat &= ~((1 << CONTROL_STATUS_INTERRUPT)
+			  | (1 << SUSPEND_REQUEST_INTERRUPT)
+			  | (1 << RESUME_INTERRUPT)
+			  | (1 << SOF_INTERRUPT));
+	else
+		stat &= ~((1 << CONTROL_STATUS_INTERRUPT)
+			  | (1 << RESUME_INTERRUPT)
+			  | (1 << SOF_DOWN_INTERRUPT)
+			  | (1 << SOF_INTERRUPT));
+
+	if (!stat)
+		return;
+	// DEBUG (dev, "irqstat1 %08x\n", stat);
+
+	/* DMA status, for ep-{a,b,c,d} */
+	scratch = stat & DMA_INTERRUPTS;
+	stat &= ~DMA_INTERRUPTS;
+	scratch >>= 9;
+	for (num = 0; scratch; num++) {
+		struct net2280_dma_regs	__iomem *dma;
+
+		tmp = 1 << num;
+		if ((tmp & scratch) == 0)
+			continue;
+		scratch ^= tmp;
+
+		ep = &dev->ep [num + 1];
+		dma = ep->dma;
+
+		if (!dma)
+			continue;
+
+		/* clear ep's dma status */
+		tmp = readl (&dma->dmastat);
+		writel (tmp, &dma->dmastat);
+
+		/* chaining should stop on abort, short OUT from fifo,
+		 * or (stat0 codepath) short OUT transfer.
+		 */
+		if (!use_dma_chaining) {
+			if ((tmp & (1 << DMA_TRANSACTION_DONE_INTERRUPT))
+					== 0) {
+				DEBUG (ep->dev, "%s no xact done? %08x\n",
+					ep->ep.name, tmp);
+				continue;
+			}
+			stop_dma (ep->dma);
+		}
+
+		/* OUT transfers terminate when the data from the
+		 * host is in our memory.  Process whatever's done.
+		 * On this path, we know transfer's last packet wasn't
+		 * less than req->length. NAK_OUT_PACKETS may be set,
+		 * or the FIFO may already be holding new packets.
+		 *
+		 * IN transfers can linger in the FIFO for a very
+		 * long time ... we ignore that for now, accounting
+		 * precisely (like PIO does) needs per-packet irqs
+		 */
+		scan_dma_completions (ep);
+
+		/* disable dma on inactive queues; else maybe restart */
+		if (list_empty (&ep->queue)) {
+			if (use_dma_chaining)
+				stop_dma (ep->dma);
+		} else {
+			tmp = readl (&dma->dmactl);
+			if (!use_dma_chaining
+					|| (tmp & (1 << DMA_ENABLE)) == 0)
+				restart_dma (ep);
+			else if (ep->is_in && use_dma_chaining) {
+				struct net2280_request	*req;
+				__le32			dmacount;
+
+				/* the descriptor at the head of the chain
+				 * may still have VALID_BIT clear; that's
+				 * used to trigger changing DMA_FIFO_VALIDATE
+				 * (affects automagic zlp writes).
+				 */
+				req = list_entry (ep->queue.next,
+						struct net2280_request, queue);
+				dmacount = req->td->dmacount;
+				dmacount &= __constant_cpu_to_le32 (
+						(1 << VALID_BIT)
+						| DMA_BYTE_COUNT_MASK);
+				if (dmacount && (dmacount & valid_bit) == 0)
+					restart_dma (ep);
+			}
+		}
+		ep->irqs++;
+	}
+
+	/* NOTE:  there are other PCI errors we might usefully notice.
+	 * if they appear very often, here's where to try recovering.
+	 */
+	if (stat & PCI_ERROR_INTERRUPTS) {
+		ERROR (dev, "pci dma error; stat %08x\n", stat);
+		stat &= ~PCI_ERROR_INTERRUPTS;
+		/* these are fatal errors, but "maybe" they won't
+		 * happen again ...
+		 */
+		stop_activity (dev, dev->driver);
+		ep0_start (dev);
+		stat = 0;
+	}
+
+	if (stat)
+		DEBUG (dev, "unhandled irqstat1 %08x\n", stat);
+}
+
+static irqreturn_t net2280_irq (int irq, void *_dev)
+{
+	struct net2280		*dev = _dev;
+
+	/* shared interrupt, not ours */
+	if (!(readl(&dev->regs->irqstat0) & (1 << INTA_ASSERTED)))
+		return IRQ_NONE;
+
+	spin_lock (&dev->lock);
+
+	/* handle disconnect, dma, and more */
+	handle_stat1_irqs (dev, readl (&dev->regs->irqstat1));
+
+	/* control requests and PIO */
+	handle_stat0_irqs (dev, readl (&dev->regs->irqstat0));
+
+	spin_unlock (&dev->lock);
+
+	return IRQ_HANDLED;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void gadget_release (struct device *_dev)
+{
+	struct net2280	*dev = dev_get_drvdata (_dev);
+
+	kfree (dev);
+}
+
+/* tear down the binding between this driver and the pci device */
+
+static void net2280_remove (struct pci_dev *pdev)
+{
+	struct net2280		*dev = pci_get_drvdata (pdev);
+
+	/* start with the driver above us */
+	if (dev->driver) {
+		/* should have been done already by driver model core */
+		WARN (dev, "pci remove, driver '%s' is still registered\n",
+				dev->driver->driver.name);
+		usb_gadget_unregister_driver (dev->driver);
+	}
+
+	/* then clean up the resources we allocated during probe() */
+	net2280_led_shutdown (dev);
+	if (dev->requests) {
+		int		i;
+		for (i = 1; i < 5; i++) {
+			if (!dev->ep [i].dummy)
+				continue;
+			pci_pool_free (dev->requests, dev->ep [i].dummy,
+					dev->ep [i].td_dma);
+		}
+		pci_pool_destroy (dev->requests);
+	}
+	if (dev->got_irq)
+		free_irq (pdev->irq, dev);
+	if (dev->regs)
+		iounmap (dev->regs);
+	if (dev->region)
+		release_mem_region (pci_resource_start (pdev, 0),
+				pci_resource_len (pdev, 0));
+	if (dev->enabled)
+		pci_disable_device (pdev);
+	device_unregister (&dev->gadget.dev);
+	device_remove_file (&pdev->dev, &dev_attr_registers);
+	pci_set_drvdata (pdev, NULL);
+
+	INFO (dev, "unbind\n");
+
+	the_controller = NULL;
+}
+
+/* wrap this driver around the specified device, but
+ * don't respond over USB until a gadget driver binds to us.
+ */
+
+static int net2280_probe (struct pci_dev *pdev, const struct pci_device_id *id)
+{
+	struct net2280		*dev;
+	unsigned long		resource, len;
+	void			__iomem *base = NULL;
+	int			retval, i;
+
+	/* if you want to support more than one controller in a system,
+	 * usb_gadget_driver_{register,unregister}() must change.
+	 */
+	if (the_controller) {
+		dev_warn (&pdev->dev, "ignoring\n");
+		return -EBUSY;
+	}
+
+	/* alloc, and start init */
+	dev = kzalloc (sizeof *dev, SLAB_KERNEL);
+	if (dev == NULL){
+		retval = -ENOMEM;
+		goto done;
+	}
+
+	pci_set_drvdata (pdev, dev);
+	spin_lock_init (&dev->lock);
+	dev->pdev = pdev;
+	dev->gadget.ops = &net2280_ops;
+	dev->gadget.is_dualspeed = 1;
+
+	/* the "gadget" abstracts/virtualizes the controller */
+	strcpy (dev->gadget.dev.bus_id, "gadget");
+	dev->gadget.dev.parent = &pdev->dev;
+	dev->gadget.dev.dma_mask = pdev->dev.dma_mask;
+	dev->gadget.dev.release = gadget_release;
+	dev->gadget.name = driver_name;
+
+	/* now all the pci goodies ... */
+	if (pci_enable_device (pdev) < 0) {
+	        retval = -ENODEV;
+		goto done;
+	}
+	dev->enabled = 1;
+
+	/* BAR 0 holds all the registers
+	 * BAR 1 is 8051 memory; unused here (note erratum 0103)
+	 * BAR 2 is fifo memory; unused here
+	 */
+	resource = pci_resource_start (pdev, 0);
+	len = pci_resource_len (pdev, 0);
+	if (!request_mem_region (resource, len, driver_name)) {
+		DEBUG (dev, "controller already in use\n");
+		retval = -EBUSY;
+		goto done;
+	}
+	dev->region = 1;
+
+	/* FIXME provide firmware download interface to put
+	 * 8051 code into the chip, e.g. to turn on PCI PM.
+	 */
+
+	base = ioremap_nocache (resource, len);
+	if (base == NULL) {
+		DEBUG (dev, "can't map memory\n");
+		retval = -EFAULT;
+		goto done;
+	}
+	dev->regs = (struct net2280_regs __iomem *) base;
+	dev->usb = (struct net2280_usb_regs __iomem *) (base + 0x0080);
+	dev->pci = (struct net2280_pci_regs __iomem *) (base + 0x0100);
+	dev->dma = (struct net2280_dma_regs __iomem *) (base + 0x0180);
+	dev->dep = (struct net2280_dep_regs __iomem *) (base + 0x0200);
+	dev->epregs = (struct net2280_ep_regs __iomem *) (base + 0x0300);
+
+	/* put into initial config, link up all endpoints */
+	writel (0, &dev->usb->usbctl);
+	usb_reset (dev);
+	usb_reinit (dev);
+
+	/* irq setup after old hardware is cleaned up */
+	if (!pdev->irq) {
+		ERROR (dev, "No IRQ.  Check PCI setup!\n");
+		retval = -ENODEV;
+		goto done;
+	}
+
+	if (request_irq (pdev->irq, net2280_irq, IRQF_SHARED, driver_name, dev)
+			!= 0) {
+		ERROR (dev, "request interrupt %d failed\n", pdev->irq);
+		retval = -EBUSY;
+		goto done;
+	}
+	dev->got_irq = 1;
+
+	/* DMA setup */
+	/* NOTE:  we know only the 32 LSBs of dma addresses may be nonzero */
+	dev->requests = pci_pool_create ("requests", pdev,
+		sizeof (struct net2280_dma),
+		0 /* no alignment requirements */,
+		0 /* or page-crossing issues */);
+	if (!dev->requests) {
+		DEBUG (dev, "can't get request pool\n");
+		retval = -ENOMEM;
+		goto done;
+	}
+	for (i = 1; i < 5; i++) {
+		struct net2280_dma	*td;
+
+		td = pci_pool_alloc (dev->requests, GFP_KERNEL,
+				&dev->ep [i].td_dma);
+		if (!td) {
+			DEBUG (dev, "can't get dummy %d\n", i);
+			retval = -ENOMEM;
+			goto done;
+		}
+		td->dmacount = 0;	/* not VALID */
+		td->dmaaddr = __constant_cpu_to_le32 (DMA_ADDR_INVALID);
+		td->dmadesc = td->dmaaddr;
+		dev->ep [i].dummy = td;
+	}
+
+	/* enable lower-overhead pci memory bursts during DMA */
+	writel ( (1 << DMA_MEMORY_WRITE_AND_INVALIDATE_ENABLE)
+			// 256 write retries may not be enough...
+			// | (1 << PCI_RETRY_ABORT_ENABLE)
+			| (1 << DMA_READ_MULTIPLE_ENABLE)
+			| (1 << DMA_READ_LINE_ENABLE)
+			, &dev->pci->pcimstctl);
+	/* erratum 0115 shouldn't appear: Linux inits PCI_LATENCY_TIMER */
+	pci_set_master (pdev);
+	pci_set_mwi (pdev);
+
+	/* ... also flushes any posted pci writes */
+	dev->chiprev = get_idx_reg (dev->regs, REG_CHIPREV) & 0xffff;
+
+	/* done */
+	INFO (dev, "%s\n", driver_desc);
+	INFO (dev, "irq %d, pci mem %p, chip rev %04x\n",
+			pdev->irq, base, dev->chiprev);
+	INFO (dev, "version: " DRIVER_VERSION "; dma %s\n",
+			use_dma
+				? (use_dma_chaining ? "chaining" : "enabled")
+				: "disabled");
+	the_controller = dev;
+
+	retval = device_register (&dev->gadget.dev);
+	if (retval) goto done;
+	retval = device_create_file (&pdev->dev, &dev_attr_registers);
+	if (retval) goto done;
+
+	return 0;
+
+done:
+	if (dev)
+		net2280_remove (pdev);
+	return retval;
+}
+
+/* make sure the board is quiescent; otherwise it will continue
+ * generating IRQs across the upcoming reboot.
+ */
+
+static void net2280_shutdown (struct pci_dev *pdev)
+{
+	struct net2280		*dev = pci_get_drvdata (pdev);
+
+	/* disable IRQs */
+	writel (0, &dev->regs->pciirqenb0);
+	writel (0, &dev->regs->pciirqenb1);
+
+	/* disable the pullup so the host will think we're gone */
+	writel (0, &dev->usb->usbctl);
+}
+
+
+/*-------------------------------------------------------------------------*/
+
+static const struct pci_device_id pci_ids [] = { {
+	.class =	((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
+	.class_mask =	~0,
+	.vendor =	0x17cc,
+	.device =	0x2280,
+	.subvendor =	PCI_ANY_ID,
+	.subdevice =	PCI_ANY_ID,
+}, {
+	.class =	((PCI_CLASS_SERIAL_USB << 8) | 0xfe),
+	.class_mask =	~0,
+	.vendor =	0x17cc,
+	.device =	0x2282,
+	.subvendor =	PCI_ANY_ID,
+	.subdevice =	PCI_ANY_ID,
+
+}, { /* end: all zeroes */ }
+};
+MODULE_DEVICE_TABLE (pci, pci_ids);
+
+/* pci driver glue; this is a "new style" PCI driver module */
+static struct pci_driver net2280_pci_driver = {
+	.name =		(char *) driver_name,
+	.id_table =	pci_ids,
+
+	.probe =	net2280_probe,
+	.remove =	net2280_remove,
+	.shutdown =	net2280_shutdown,
+
+	/* FIXME add power management support */
+};
+
+MODULE_DESCRIPTION (DRIVER_DESC);
+MODULE_AUTHOR ("David Brownell");
+MODULE_LICENSE ("GPL");
+
+static int __init init (void)
+{
+	if (!use_dma)
+		use_dma_chaining = 0;
+	return pci_register_driver (&net2280_pci_driver);
+}
+module_init (init);
+
+static void __exit cleanup (void)
+{
+	pci_unregister_driver (&net2280_pci_driver);
+}
+module_exit (cleanup);