usb: gadget: at91_udc: port linux driver at91_udc

port at91_udc driver from linux:

original commit Message:
commit c94e289f195e0e13cf34d27f9338d28221a85751
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Sat Apr 11 00:14:21 2015 +0200

    usb: gadget: remove incorrect __init/__exit annotations

    A recent change introduced a link error for the composite
    printer gadget driver:

    `printer_unbind' referenced in section `.ref.data' of drivers/built-in.o: defined in discarded section `.exit.text' of drivers/built-in.o

    Evidently the unbind function should not be marked __exit here,
    because it is called through a callback pointer that is not necessarily
    discarded, __composite_unbind() is indeed called from the error path of
    composite_bind(), which can never work for a built-in driver.

    Looking at the surrounding code, I found the same problem in all other
    composite gadget drivers in both the bind and unbind functions, as
    well as the udc platform driver 'remove' functions. Those will break
    if anyone uses the 'unbind' sysfs attribute to detach a device from a
    built-in driver.

    This patch removes the incorrect annotations from all the gadget
    drivers.

Signed-off-by: Heiko Schocher <hs@denx.de>

2 files changed, 2211 insertions, 0 deletions

diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
new file mode 100644
index 00000000000..fc4226462f8
--- /dev/null
+++ b/drivers/usb/gadget/at91_udc.c
@@ -0,0 +1,2036 @@
+/*
+ * at91_udc -- driver for at91-series USB peripheral controller
+ *
+ * Copyright (C) 2004 by Thomas Rathbone
+ * Copyright (C) 2005 by HP Labs
+ * Copyright (C) 2005 by David Brownell
+ *
+ * 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.
+ */
+
+#undef	VERBOSE_DEBUG
+#undef	PACKET_TRACE
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <linux/ioport.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/list.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/prefetch.h>
+#include <linux/clk.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
+#include <linux/platform_data/atmel.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/atmel-matrix.h>
+
+#include "at91_udc.h"
+
+
+/*
+ * This controller is simple and PIO-only.  It's used in many AT91-series
+ * full speed USB controllers, including the at91rm9200 (arm920T, with MMU),
+ * at91sam926x (arm926ejs, with MMU), and several no-mmu versions.
+ *
+ * This driver expects the board has been wired with two GPIOs supporting
+ * a VBUS sensing IRQ, and a D+ pullup.  (They may be omitted, but the
+ * testing hasn't covered such cases.)
+ *
+ * The pullup is most important (so it's integrated on sam926x parts).  It
+ * provides software control over whether the host enumerates the device.
+ *
+ * The VBUS sensing helps during enumeration, and allows both USB clocks
+ * (and the transceiver) to stay gated off until they're necessary, saving
+ * power.  During USB suspend, the 48 MHz clock is gated off in hardware;
+ * it may also be gated off by software during some Linux sleep states.
+ */
+
+#define	DRIVER_VERSION	"3 May 2006"
+
+static const char driver_name [] = "at91_udc";
+static const char * const ep_names[] = {
+	"ep0",
+	"ep1",
+	"ep2",
+	"ep3-int",
+	"ep4",
+	"ep5",
+};
+#define ep0name		ep_names[0]
+
+#define VBUS_POLL_TIMEOUT	msecs_to_jiffies(1000)
+
+#define at91_udp_read(udc, reg) \
+	__raw_readl((udc)->udp_baseaddr + (reg))
+#define at91_udp_write(udc, reg, val) \
+	__raw_writel((val), (udc)->udp_baseaddr + (reg))
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef CONFIG_USB_GADGET_DEBUG_FILES
+
+#include <linux/seq_file.h>
+
+static const char debug_filename[] = "driver/udc";
+
+#define FOURBITS "%s%s%s%s"
+#define EIGHTBITS FOURBITS FOURBITS
+
+static void proc_ep_show(struct seq_file *s, struct at91_ep *ep)
+{
+	static char		*types[] = {
+		"control", "out-iso", "out-bulk", "out-int",
+		"BOGUS",   "in-iso",  "in-bulk",  "in-int"};
+
+	u32			csr;
+	struct at91_request	*req;
+	unsigned long	flags;
+	struct at91_udc	*udc = ep->udc;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	csr = __raw_readl(ep->creg);
+
+	/* NOTE:  not collecting per-endpoint irq statistics... */
+
+	seq_printf(s, "\n");
+	seq_printf(s, "%s, maxpacket %d %s%s %s%s\n",
+			ep->ep.name, ep->ep.maxpacket,
+			ep->is_in ? "in" : "out",
+			ep->is_iso ? " iso" : "",
+			ep->is_pingpong
+				? (ep->fifo_bank ? "pong" : "ping")
+				: "",
+			ep->stopped ? " stopped" : "");
+	seq_printf(s, "csr %08x rxbytes=%d %s %s %s" EIGHTBITS "\n",
+		csr,
+		(csr & 0x07ff0000) >> 16,
+		(csr & (1 << 15)) ? "enabled" : "disabled",
+		(csr & (1 << 11)) ? "DATA1" : "DATA0",
+		types[(csr & 0x700) >> 8],
+
+		/* iff type is control then print current direction */
+		(!(csr & 0x700))
+			? ((csr & (1 << 7)) ? " IN" : " OUT")
+			: "",
+		(csr & (1 << 6)) ? " rxdatabk1" : "",
+		(csr & (1 << 5)) ? " forcestall" : "",
+		(csr & (1 << 4)) ? " txpktrdy" : "",
+
+		(csr & (1 << 3)) ? " stallsent" : "",
+		(csr & (1 << 2)) ? " rxsetup" : "",
+		(csr & (1 << 1)) ? " rxdatabk0" : "",
+		(csr & (1 << 0)) ? " txcomp" : "");
+	if (list_empty (&ep->queue))
+		seq_printf(s, "\t(queue empty)\n");
+
+	else list_for_each_entry (req, &ep->queue, queue) {
+		unsigned	length = req->req.actual;
+
+		seq_printf(s, "\treq %p len %d/%d buf %p\n",
+				&req->req, length,
+				req->req.length, req->req.buf);
+	}
+	spin_unlock_irqrestore(&udc->lock, flags);
+}
+
+static void proc_irq_show(struct seq_file *s, const char *label, u32 mask)
+{
+	int i;
+
+	seq_printf(s, "%s %04x:%s%s" FOURBITS, label, mask,
+		(mask & (1 << 13)) ? " wakeup" : "",
+		(mask & (1 << 12)) ? " endbusres" : "",
+
+		(mask & (1 << 11)) ? " sofint" : "",
+		(mask & (1 << 10)) ? " extrsm" : "",
+		(mask & (1 << 9)) ? " rxrsm" : "",
+		(mask & (1 << 8)) ? " rxsusp" : "");
+	for (i = 0; i < 8; i++) {
+		if (mask & (1 << i))
+			seq_printf(s, " ep%d", i);
+	}
+	seq_printf(s, "\n");
+}
+
+static int proc_udc_show(struct seq_file *s, void *unused)
+{
+	struct at91_udc	*udc = s->private;
+	struct at91_ep	*ep;
+	u32		tmp;
+
+	seq_printf(s, "%s: version %s\n", driver_name, DRIVER_VERSION);
+
+	seq_printf(s, "vbus %s, pullup %s, %s powered%s, gadget %s\n\n",
+		udc->vbus ? "present" : "off",
+		udc->enabled
+			? (udc->vbus ? "active" : "enabled")
+			: "disabled",
+		udc->gadget.is_selfpowered ? "self" : "VBUS",
+		udc->suspended ? ", suspended" : "",
+		udc->driver ? udc->driver->driver.name : "(none)");
+
+	/* don't access registers when interface isn't clocked */
+	if (!udc->clocked) {
+		seq_printf(s, "(not clocked)\n");
+		return 0;
+	}
+
+	tmp = at91_udp_read(udc, AT91_UDP_FRM_NUM);
+	seq_printf(s, "frame %05x:%s%s frame=%d\n", tmp,
+		(tmp & AT91_UDP_FRM_OK) ? " ok" : "",
+		(tmp & AT91_UDP_FRM_ERR) ? " err" : "",
+		(tmp & AT91_UDP_NUM));
+
+	tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
+	seq_printf(s, "glbstate %02x:%s" FOURBITS "\n", tmp,
+		(tmp & AT91_UDP_RMWUPE) ? " rmwupe" : "",
+		(tmp & AT91_UDP_RSMINPR) ? " rsminpr" : "",
+		(tmp & AT91_UDP_ESR) ? " esr" : "",
+		(tmp & AT91_UDP_CONFG) ? " confg" : "",
+		(tmp & AT91_UDP_FADDEN) ? " fadden" : "");
+
+	tmp = at91_udp_read(udc, AT91_UDP_FADDR);
+	seq_printf(s, "faddr   %03x:%s fadd=%d\n", tmp,
+		(tmp & AT91_UDP_FEN) ? " fen" : "",
+		(tmp & AT91_UDP_FADD));
+
+	proc_irq_show(s, "imr   ", at91_udp_read(udc, AT91_UDP_IMR));
+	proc_irq_show(s, "isr   ", at91_udp_read(udc, AT91_UDP_ISR));
+
+	if (udc->enabled && udc->vbus) {
+		proc_ep_show(s, &udc->ep[0]);
+		list_for_each_entry (ep, &udc->gadget.ep_list, ep.ep_list) {
+			if (ep->ep.desc)
+				proc_ep_show(s, ep);
+		}
+	}
+	return 0;
+}
+
+static int proc_udc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, proc_udc_show, PDE_DATA(inode));
+}
+
+static const struct file_operations proc_ops = {
+	.owner		= THIS_MODULE,
+	.open		= proc_udc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static void create_debug_file(struct at91_udc *udc)
+{
+	udc->pde = proc_create_data(debug_filename, 0, NULL, &proc_ops, udc);
+}
+
+static void remove_debug_file(struct at91_udc *udc)
+{
+	if (udc->pde)
+		remove_proc_entry(debug_filename, NULL);
+}
+
+#else
+
+static inline void create_debug_file(struct at91_udc *udc) {}
+static inline void remove_debug_file(struct at91_udc *udc) {}
+
+#endif
+
+
+/*-------------------------------------------------------------------------*/
+
+static void done(struct at91_ep *ep, struct at91_request *req, int status)
+{
+	unsigned	stopped = ep->stopped;
+	struct at91_udc	*udc = ep->udc;
+
+	list_del_init(&req->queue);
+	if (req->req.status == -EINPROGRESS)
+		req->req.status = status;
+	else
+		status = req->req.status;
+	if (status && status != -ESHUTDOWN)
+		VDBG("%s done %p, status %d\n", ep->ep.name, req, status);
+
+	ep->stopped = 1;
+	spin_unlock(&udc->lock);
+	usb_gadget_giveback_request(&ep->ep, &req->req);
+	spin_lock(&udc->lock);
+	ep->stopped = stopped;
+
+	/* ep0 is always ready; other endpoints need a non-empty queue */
+	if (list_empty(&ep->queue) && ep->int_mask != (1 << 0))
+		at91_udp_write(udc, AT91_UDP_IDR, ep->int_mask);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/* bits indicating OUT fifo has data ready */
+#define	RX_DATA_READY	(AT91_UDP_RX_DATA_BK0 | AT91_UDP_RX_DATA_BK1)
+
+/*
+ * Endpoint FIFO CSR bits have a mix of bits, making it unsafe to just write
+ * back most of the value you just read (because of side effects, including
+ * bits that may change after reading and before writing).
+ *
+ * Except when changing a specific bit, always write values which:
+ *  - clear SET_FX bits (setting them could change something)
+ *  - set CLR_FX bits (clearing them could change something)
+ *
+ * There are also state bits like FORCESTALL, EPEDS, DIR, and EPTYPE
+ * that shouldn't normally be changed.
+ *
+ * NOTE at91sam9260 docs mention synch between UDPCK and MCK clock domains,
+ * implying a need to wait for one write to complete (test relevant bits)
+ * before starting the next write.  This shouldn't be an issue given how
+ * infrequently we write, except maybe for write-then-read idioms.
+ */
+#define	SET_FX	(AT91_UDP_TXPKTRDY)
+#define	CLR_FX	(RX_DATA_READY | AT91_UDP_RXSETUP \
+		| AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)
+
+/* pull OUT packet data from the endpoint's fifo */
+static int read_fifo (struct at91_ep *ep, struct at91_request *req)
+{
+	u32 __iomem	*creg = ep->creg;
+	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
+	u32		csr;
+	u8		*buf;
+	unsigned int	count, bufferspace, is_done;
+
+	buf = req->req.buf + req->req.actual;
+	bufferspace = req->req.length - req->req.actual;
+
+	/*
+	 * there might be nothing to read if ep_queue() calls us,
+	 * or if we already emptied both pingpong buffers
+	 */
+rescan:
+	csr = __raw_readl(creg);
+	if ((csr & RX_DATA_READY) == 0)
+		return 0;
+
+	count = (csr & AT91_UDP_RXBYTECNT) >> 16;
+	if (count > ep->ep.maxpacket)
+		count = ep->ep.maxpacket;
+	if (count > bufferspace) {
+		DBG("%s buffer overflow\n", ep->ep.name);
+		req->req.status = -EOVERFLOW;
+		count = bufferspace;
+	}
+	__raw_readsb(dreg, buf, count);
+
+	/* release and swap pingpong mem bank */
+	csr |= CLR_FX;
+	if (ep->is_pingpong) {
+		if (ep->fifo_bank == 0) {
+			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
+			ep->fifo_bank = 1;
+		} else {
+			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK1);
+			ep->fifo_bank = 0;
+		}
+	} else
+		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
+	__raw_writel(csr, creg);
+
+	req->req.actual += count;
+	is_done = (count < ep->ep.maxpacket);
+	if (count == bufferspace)
+		is_done = 1;
+
+	PACKET("%s %p out/%d%s\n", ep->ep.name, &req->req, count,
+			is_done ? " (done)" : "");
+
+	/*
+	 * avoid extra trips through IRQ logic for packets already in
+	 * the fifo ... maybe preventing an extra (expensive) OUT-NAK
+	 */
+	if (is_done)
+		done(ep, req, 0);
+	else if (ep->is_pingpong) {
+		/*
+		 * One dummy read to delay the code because of a HW glitch:
+		 * CSR returns bad RXCOUNT when read too soon after updating
+		 * RX_DATA_BK flags.
+		 */
+		csr = __raw_readl(creg);
+
+		bufferspace -= count;
+		buf += count;
+		goto rescan;
+	}
+
+	return is_done;
+}
+
+/* load fifo for an IN packet */
+static int write_fifo(struct at91_ep *ep, struct at91_request *req)
+{
+	u32 __iomem	*creg = ep->creg;
+	u32		csr = __raw_readl(creg);
+	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
+	unsigned	total, count, is_last;
+	u8		*buf;
+
+	/*
+	 * TODO: allow for writing two packets to the fifo ... that'll
+	 * reduce the amount of IN-NAKing, but probably won't affect
+	 * throughput much.  (Unlike preventing OUT-NAKing!)
+	 */
+
+	/*
+	 * If ep_queue() calls us, the queue is empty and possibly in
+	 * odd states like TXCOMP not yet cleared (we do it, saving at
+	 * least one IRQ) or the fifo not yet being free.  Those aren't
+	 * issues normally (IRQ handler fast path).
+	 */
+	if (unlikely(csr & (AT91_UDP_TXCOMP | AT91_UDP_TXPKTRDY))) {
+		if (csr & AT91_UDP_TXCOMP) {
+			csr |= CLR_FX;
+			csr &= ~(SET_FX | AT91_UDP_TXCOMP);
+			__raw_writel(csr, creg);
+			csr = __raw_readl(creg);
+		}
+		if (csr & AT91_UDP_TXPKTRDY)
+			return 0;
+	}
+
+	buf = req->req.buf + req->req.actual;
+	prefetch(buf);
+	total = req->req.length - req->req.actual;
+	if (ep->ep.maxpacket < total) {
+		count = ep->ep.maxpacket;
+		is_last = 0;
+	} else {
+		count = total;
+		is_last = (count < ep->ep.maxpacket) || !req->req.zero;
+	}
+
+	/*
+	 * Write the packet, maybe it's a ZLP.
+	 *
+	 * NOTE:  incrementing req->actual before we receive the ACK means
+	 * gadget driver IN bytecounts can be wrong in fault cases.  That's
+	 * fixable with PIO drivers like this one (save "count" here, and
+	 * do the increment later on TX irq), but not for most DMA hardware.
+	 *
+	 * So all gadget drivers must accept that potential error.  Some
+	 * hardware supports precise fifo status reporting, letting them
+	 * recover when the actual bytecount matters (e.g. for USB Test
+	 * and Measurement Class devices).
+	 */
+	__raw_writesb(dreg, buf, count);
+	csr &= ~SET_FX;
+	csr |= CLR_FX | AT91_UDP_TXPKTRDY;
+	__raw_writel(csr, creg);
+	req->req.actual += count;
+
+	PACKET("%s %p in/%d%s\n", ep->ep.name, &req->req, count,
+			is_last ? " (done)" : "");
+	if (is_last)
+		done(ep, req, 0);
+	return is_last;
+}
+
+static void nuke(struct at91_ep *ep, int status)
+{
+	struct at91_request *req;
+
+	/* terminate any request in the queue */
+	ep->stopped = 1;
+	if (list_empty(&ep->queue))
+		return;
+
+	VDBG("%s %s\n", __func__, ep->ep.name);
+	while (!list_empty(&ep->queue)) {
+		req = list_entry(ep->queue.next, struct at91_request, queue);
+		done(ep, req, status);
+	}
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int at91_ep_enable(struct usb_ep *_ep,
+				const struct usb_endpoint_descriptor *desc)
+{
+	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
+	struct at91_udc *udc;
+	u16		maxpacket;
+	u32		tmp;
+	unsigned long	flags;
+
+	if (!_ep || !ep
+			|| !desc || _ep->name == ep0name
+			|| desc->bDescriptorType != USB_DT_ENDPOINT
+			|| (maxpacket = usb_endpoint_maxp(desc)) == 0
+			|| maxpacket > ep->maxpacket) {
+		DBG("bad ep or descriptor\n");
+		return -EINVAL;
+	}
+
+	udc = ep->udc;
+	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
+		DBG("bogus device state\n");
+		return -ESHUTDOWN;
+	}
+
+	tmp = usb_endpoint_type(desc);
+	switch (tmp) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		DBG("only one control endpoint\n");
+		return -EINVAL;
+	case USB_ENDPOINT_XFER_INT:
+		if (maxpacket > 64)
+			goto bogus_max;
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		switch (maxpacket) {
+		case 8:
+		case 16:
+		case 32:
+		case 64:
+			goto ok;
+		}
+bogus_max:
+		DBG("bogus maxpacket %d\n", maxpacket);
+		return -EINVAL;
+	case USB_ENDPOINT_XFER_ISOC:
+		if (!ep->is_pingpong) {
+			DBG("iso requires double buffering\n");
+			return -EINVAL;
+		}
+		break;
+	}
+
+ok:
+	spin_lock_irqsave(&udc->lock, flags);
+
+	/* initialize endpoint to match this descriptor */
+	ep->is_in = usb_endpoint_dir_in(desc);
+	ep->is_iso = (tmp == USB_ENDPOINT_XFER_ISOC);
+	ep->stopped = 0;
+	if (ep->is_in)
+		tmp |= 0x04;
+	tmp <<= 8;
+	tmp |= AT91_UDP_EPEDS;
+	__raw_writel(tmp, ep->creg);
+
+	ep->ep.maxpacket = maxpacket;
+
+	/*
+	 * reset/init endpoint fifo.  NOTE:  leaves fifo_bank alone,
+	 * since endpoint resets don't reset hw pingpong state.
+	 */
+	at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
+	at91_udp_write(udc, AT91_UDP_RST_EP, 0);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+static int at91_ep_disable (struct usb_ep * _ep)
+{
+	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
+	struct at91_udc	*udc = ep->udc;
+	unsigned long	flags;
+
+	if (ep == &ep->udc->ep[0])
+		return -EINVAL;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	nuke(ep, -ESHUTDOWN);
+
+	/* restore the endpoint's pristine config */
+	ep->ep.desc = NULL;
+	ep->ep.maxpacket = ep->maxpacket;
+
+	/* reset fifos and endpoint */
+	if (ep->udc->clocked) {
+		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
+		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
+		__raw_writel(0, ep->creg);
+	}
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+/*
+ * this is a PIO-only driver, so there's nothing
+ * interesting for request or buffer allocation.
+ */
+
+static struct usb_request *
+at91_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
+{
+	struct at91_request *req;
+
+	req = kzalloc(sizeof (struct at91_request), gfp_flags);
+	if (!req)
+		return NULL;
+
+	INIT_LIST_HEAD(&req->queue);
+	return &req->req;
+}
+
+static void at91_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct at91_request *req;
+
+	req = container_of(_req, struct at91_request, req);
+	BUG_ON(!list_empty(&req->queue));
+	kfree(req);
+}
+
+static int at91_ep_queue(struct usb_ep *_ep,
+			struct usb_request *_req, gfp_t gfp_flags)
+{
+	struct at91_request	*req;
+	struct at91_ep		*ep;
+	struct at91_udc		*udc;
+	int			status;
+	unsigned long		flags;
+
+	req = container_of(_req, struct at91_request, req);
+	ep = container_of(_ep, struct at91_ep, ep);
+
+	if (!_req || !_req->complete
+			|| !_req->buf || !list_empty(&req->queue)) {
+		DBG("invalid request\n");
+		return -EINVAL;
+	}
+
+	if (!_ep || (!ep->ep.desc && ep->ep.name != ep0name)) {
+		DBG("invalid ep\n");
+		return -EINVAL;
+	}
+
+	udc = ep->udc;
+
+	if (!udc || !udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
+		DBG("invalid device\n");
+		return -EINVAL;
+	}
+
+	_req->status = -EINPROGRESS;
+	_req->actual = 0;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	/* try to kickstart any empty and idle queue */
+	if (list_empty(&ep->queue) && !ep->stopped) {
+		int	is_ep0;
+
+		/*
+		 * If this control request has a non-empty DATA stage, this
+		 * will start that stage.  It works just like a non-control
+		 * request (until the status stage starts, maybe early).
+		 *
+		 * If the data stage is empty, then this starts a successful
+		 * IN/STATUS stage.  (Unsuccessful ones use set_halt.)
+		 */
+		is_ep0 = (ep->ep.name == ep0name);
+		if (is_ep0) {
+			u32	tmp;
+
+			if (!udc->req_pending) {
+				status = -EINVAL;
+				goto done;
+			}
+
+			/*
+			 * defer changing CONFG until after the gadget driver
+			 * reconfigures the endpoints.
+			 */
+			if (udc->wait_for_config_ack) {
+				tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
+				tmp ^= AT91_UDP_CONFG;
+				VDBG("toggle config\n");
+				at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
+			}
+			if (req->req.length == 0) {
+ep0_in_status:
+				PACKET("ep0 in/status\n");
+				status = 0;
+				tmp = __raw_readl(ep->creg);
+				tmp &= ~SET_FX;
+				tmp |= CLR_FX | AT91_UDP_TXPKTRDY;
+				__raw_writel(tmp, ep->creg);
+				udc->req_pending = 0;
+				goto done;
+			}
+		}
+
+		if (ep->is_in)
+			status = write_fifo(ep, req);
+		else {
+			status = read_fifo(ep, req);
+
+			/* IN/STATUS stage is otherwise triggered by irq */
+			if (status && is_ep0)
+				goto ep0_in_status;
+		}
+	} else
+		status = 0;
+
+	if (req && !status) {
+		list_add_tail (&req->queue, &ep->queue);
+		at91_udp_write(udc, AT91_UDP_IER, ep->int_mask);
+	}
+done:
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return (status < 0) ? status : 0;
+}
+
+static int at91_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct at91_ep		*ep;
+	struct at91_request	*req;
+	unsigned long		flags;
+	struct at91_udc		*udc;
+
+	ep = container_of(_ep, struct at91_ep, ep);
+	if (!_ep || ep->ep.name == ep0name)
+		return -EINVAL;
+
+	udc = ep->udc;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	/* make sure it's actually queued on this endpoint */
+	list_for_each_entry (req, &ep->queue, queue) {
+		if (&req->req == _req)
+			break;
+	}
+	if (&req->req != _req) {
+		spin_unlock_irqrestore(&udc->lock, flags);
+		return -EINVAL;
+	}
+
+	done(ep, req, -ECONNRESET);
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+static int at91_ep_set_halt(struct usb_ep *_ep, int value)
+{
+	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
+	struct at91_udc	*udc = ep->udc;
+	u32 __iomem	*creg;
+	u32		csr;
+	unsigned long	flags;
+	int		status = 0;
+
+	if (!_ep || ep->is_iso || !ep->udc->clocked)
+		return -EINVAL;
+
+	creg = ep->creg;
+	spin_lock_irqsave(&udc->lock, flags);
+
+	csr = __raw_readl(creg);
+
+	/*
+	 * fail with still-busy IN endpoints, ensuring correct sequencing
+	 * of data tx then stall.  note that the fifo rx bytecount isn't
+	 * completely accurate as a tx bytecount.
+	 */
+	if (ep->is_in && (!list_empty(&ep->queue) || (csr >> 16) != 0))
+		status = -EAGAIN;
+	else {
+		csr |= CLR_FX;
+		csr &= ~SET_FX;
+		if (value) {
+			csr |= AT91_UDP_FORCESTALL;
+			VDBG("halt %s\n", ep->ep.name);
+		} else {
+			at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
+			at91_udp_write(udc, AT91_UDP_RST_EP, 0);
+			csr &= ~AT91_UDP_FORCESTALL;
+		}
+		__raw_writel(csr, creg);
+	}
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return status;
+}
+
+static const struct usb_ep_ops at91_ep_ops = {
+	.enable		= at91_ep_enable,
+	.disable	= at91_ep_disable,
+	.alloc_request	= at91_ep_alloc_request,
+	.free_request	= at91_ep_free_request,
+	.queue		= at91_ep_queue,
+	.dequeue	= at91_ep_dequeue,
+	.set_halt	= at91_ep_set_halt,
+	/* there's only imprecise fifo status reporting */
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int at91_get_frame(struct usb_gadget *gadget)
+{
+	struct at91_udc *udc = to_udc(gadget);
+
+	if (!to_udc(gadget)->clocked)
+		return -EINVAL;
+	return at91_udp_read(udc, AT91_UDP_FRM_NUM) & AT91_UDP_NUM;
+}
+
+static int at91_wakeup(struct usb_gadget *gadget)
+{
+	struct at91_udc	*udc = to_udc(gadget);
+	u32		glbstate;
+	int		status = -EINVAL;
+	unsigned long	flags;
+
+	DBG("%s\n", __func__ );
+	spin_lock_irqsave(&udc->lock, flags);
+
+	if (!udc->clocked || !udc->suspended)
+		goto done;
+
+	/* NOTE:  some "early versions" handle ESR differently ... */
+
+	glbstate = at91_udp_read(udc, AT91_UDP_GLB_STAT);
+	if (!(glbstate & AT91_UDP_ESR))
+		goto done;
+	glbstate |= AT91_UDP_ESR;
+	at91_udp_write(udc, AT91_UDP_GLB_STAT, glbstate);
+
+done:
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return status;
+}
+
+/* reinit == restore initial software state */
+static void udc_reinit(struct at91_udc *udc)
+{
+	u32 i;
+
+	INIT_LIST_HEAD(&udc->gadget.ep_list);
+	INIT_LIST_HEAD(&udc->gadget.ep0->ep_list);
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		struct at91_ep *ep = &udc->ep[i];
+
+		if (i != 0)
+			list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
+		ep->ep.desc = NULL;
+		ep->stopped = 0;
+		ep->fifo_bank = 0;
+		usb_ep_set_maxpacket_limit(&ep->ep, ep->maxpacket);
+		ep->creg = (void __iomem *) udc->udp_baseaddr + AT91_UDP_CSR(i);
+		/* initialize one queue per endpoint */
+		INIT_LIST_HEAD(&ep->queue);
+	}
+}
+
+static void reset_gadget(struct at91_udc *udc)
+{
+	struct usb_gadget_driver *driver = udc->driver;
+	int i;
+
+	if (udc->gadget.speed == USB_SPEED_UNKNOWN)
+		driver = NULL;
+	udc->gadget.speed = USB_SPEED_UNKNOWN;
+	udc->suspended = 0;
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		struct at91_ep *ep = &udc->ep[i];
+
+		ep->stopped = 1;
+		nuke(ep, -ESHUTDOWN);
+	}
+	if (driver) {
+		spin_unlock(&udc->lock);
+		usb_gadget_udc_reset(&udc->gadget, driver);
+		spin_lock(&udc->lock);
+	}
+
+	udc_reinit(udc);
+}
+
+static void stop_activity(struct at91_udc *udc)
+{
+	struct usb_gadget_driver *driver = udc->driver;
+	int i;
+
+	if (udc->gadget.speed == USB_SPEED_UNKNOWN)
+		driver = NULL;
+	udc->gadget.speed = USB_SPEED_UNKNOWN;
+	udc->suspended = 0;
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		struct at91_ep *ep = &udc->ep[i];
+		ep->stopped = 1;
+		nuke(ep, -ESHUTDOWN);
+	}
+	if (driver) {
+		spin_unlock(&udc->lock);
+		driver->disconnect(&udc->gadget);
+		spin_lock(&udc->lock);
+	}
+
+	udc_reinit(udc);
+}
+
+static void clk_on(struct at91_udc *udc)
+{
+	if (udc->clocked)
+		return;
+	udc->clocked = 1;
+
+	clk_enable(udc->iclk);
+	clk_enable(udc->fclk);
+}
+
+static void clk_off(struct at91_udc *udc)
+{
+	if (!udc->clocked)
+		return;
+	udc->clocked = 0;
+	udc->gadget.speed = USB_SPEED_UNKNOWN;
+	clk_disable(udc->fclk);
+	clk_disable(udc->iclk);
+}
+
+/*
+ * activate/deactivate link with host; minimize power usage for
+ * inactive links by cutting clocks and transceiver power.
+ */
+static void pullup(struct at91_udc *udc, int is_on)
+{
+	if (!udc->enabled || !udc->vbus)
+		is_on = 0;
+	DBG("%sactive\n", is_on ? "" : "in");
+
+	if (is_on) {
+		clk_on(udc);
+		at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
+		at91_udp_write(udc, AT91_UDP_TXVC, 0);
+	} else {
+		stop_activity(udc);
+		at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
+		at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
+		clk_off(udc);
+	}
+
+	if (udc->caps && udc->caps->pullup)
+		udc->caps->pullup(udc, is_on);
+}
+
+/* vbus is here!  turn everything on that's ready */
+static int at91_vbus_session(struct usb_gadget *gadget, int is_active)
+{
+	struct at91_udc	*udc = to_udc(gadget);
+	unsigned long	flags;
+
+	/* VDBG("vbus %s\n", is_active ? "on" : "off"); */
+	spin_lock_irqsave(&udc->lock, flags);
+	udc->vbus = (is_active != 0);
+	if (udc->driver)
+		pullup(udc, is_active);
+	else
+		pullup(udc, 0);
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+static int at91_pullup(struct usb_gadget *gadget, int is_on)
+{
+	struct at91_udc	*udc = to_udc(gadget);
+	unsigned long	flags;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	udc->enabled = is_on = !!is_on;
+	pullup(udc, is_on);
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+static int at91_set_selfpowered(struct usb_gadget *gadget, int is_on)
+{
+	struct at91_udc	*udc = to_udc(gadget);
+	unsigned long	flags;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	gadget->is_selfpowered = (is_on != 0);
+	spin_unlock_irqrestore(&udc->lock, flags);
+	return 0;
+}
+
+static int at91_start(struct usb_gadget *gadget,
+		struct usb_gadget_driver *driver);
+static int at91_stop(struct usb_gadget *gadget);
+
+static const struct usb_gadget_ops at91_udc_ops = {
+	.get_frame		= at91_get_frame,
+	.wakeup			= at91_wakeup,
+	.set_selfpowered	= at91_set_selfpowered,
+	.vbus_session		= at91_vbus_session,
+	.pullup			= at91_pullup,
+	.udc_start		= at91_start,
+	.udc_stop		= at91_stop,
+
+	/*
+	 * VBUS-powered devices may also also want to support bigger
+	 * power budgets after an appropriate SET_CONFIGURATION.
+	 */
+	/* .vbus_power		= at91_vbus_power, */
+};
+
+/*-------------------------------------------------------------------------*/
+
+static int handle_ep(struct at91_ep *ep)
+{
+	struct at91_request	*req;
+	u32 __iomem		*creg = ep->creg;
+	u32			csr = __raw_readl(creg);
+
+	if (!list_empty(&ep->queue))
+		req = list_entry(ep->queue.next,
+			struct at91_request, queue);
+	else
+		req = NULL;
+
+	if (ep->is_in) {
+		if (csr & (AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)) {
+			csr |= CLR_FX;
+			csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_TXCOMP);
+			__raw_writel(csr, creg);
+		}
+		if (req)
+			return write_fifo(ep, req);
+
+	} else {
+		if (csr & AT91_UDP_STALLSENT) {
+			/* STALLSENT bit == ISOERR */
+			if (ep->is_iso && req)
+				req->req.status = -EILSEQ;
+			csr |= CLR_FX;
+			csr &= ~(SET_FX | AT91_UDP_STALLSENT);
+			__raw_writel(csr, creg);
+			csr = __raw_readl(creg);
+		}
+		if (req && (csr & RX_DATA_READY))
+			return read_fifo(ep, req);
+	}
+	return 0;
+}
+
+union setup {
+	u8			raw[8];
+	struct usb_ctrlrequest	r;
+};
+
+static void handle_setup(struct at91_udc *udc, struct at91_ep *ep, u32 csr)
+{
+	u32 __iomem	*creg = ep->creg;
+	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
+	unsigned	rxcount, i = 0;
+	u32		tmp;
+	union setup	pkt;
+	int		status = 0;
+
+	/* read and ack SETUP; hard-fail for bogus packets */
+	rxcount = (csr & AT91_UDP_RXBYTECNT) >> 16;
+	if (likely(rxcount == 8)) {
+		while (rxcount--)
+			pkt.raw[i++] = __raw_readb(dreg);
+		if (pkt.r.bRequestType & USB_DIR_IN) {
+			csr |= AT91_UDP_DIR;
+			ep->is_in = 1;
+		} else {
+			csr &= ~AT91_UDP_DIR;
+			ep->is_in = 0;
+		}
+	} else {
+		/* REVISIT this happens sometimes under load; why?? */
+		ERR("SETUP len %d, csr %08x\n", rxcount, csr);
+		status = -EINVAL;
+	}
+	csr |= CLR_FX;
+	csr &= ~(SET_FX | AT91_UDP_RXSETUP);
+	__raw_writel(csr, creg);
+	udc->wait_for_addr_ack = 0;
+	udc->wait_for_config_ack = 0;
+	ep->stopped = 0;
+	if (unlikely(status != 0))
+		goto stall;
+
+#define w_index		le16_to_cpu(pkt.r.wIndex)
+#define w_value		le16_to_cpu(pkt.r.wValue)
+#define w_length	le16_to_cpu(pkt.r.wLength)
+
+	VDBG("SETUP %02x.%02x v%04x i%04x l%04x\n",
+			pkt.r.bRequestType, pkt.r.bRequest,
+			w_value, w_index, w_length);
+
+	/*
+	 * A few standard requests get handled here, ones that touch
+	 * hardware ... notably for device and endpoint features.
+	 */
+	udc->req_pending = 1;
+	csr = __raw_readl(creg);
+	csr |= CLR_FX;
+	csr &= ~SET_FX;
+	switch ((pkt.r.bRequestType << 8) | pkt.r.bRequest) {
+
+	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
+			| USB_REQ_SET_ADDRESS:
+		__raw_writel(csr | AT91_UDP_TXPKTRDY, creg);
+		udc->addr = w_value;
+		udc->wait_for_addr_ack = 1;
+		udc->req_pending = 0;
+		/* FADDR is set later, when we ack host STATUS */
+		return;
+
+	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
+			| USB_REQ_SET_CONFIGURATION:
+		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_CONFG;
+		if (pkt.r.wValue)
+			udc->wait_for_config_ack = (tmp == 0);
+		else
+			udc->wait_for_config_ack = (tmp != 0);
+		if (udc->wait_for_config_ack)
+			VDBG("wait for config\n");
+		/* CONFG is toggled later, if gadget driver succeeds */
+		break;
+
+	/*
+	 * Hosts may set or clear remote wakeup status, and
+	 * devices may report they're VBUS powered.
+	 */
+	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
+			| USB_REQ_GET_STATUS:
+		tmp = (udc->gadget.is_selfpowered << USB_DEVICE_SELF_POWERED);
+		if (at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_ESR)
+			tmp |= (1 << USB_DEVICE_REMOTE_WAKEUP);
+		PACKET("get device status\n");
+		__raw_writeb(tmp, dreg);
+		__raw_writeb(0, dreg);
+		goto write_in;
+		/* then STATUS starts later, automatically */
+	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
+			| USB_REQ_SET_FEATURE:
+		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
+			goto stall;
+		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
+		tmp |= AT91_UDP_ESR;
+		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
+		goto succeed;
+	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
+			| USB_REQ_CLEAR_FEATURE:
+		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
+			goto stall;
+		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
+		tmp &= ~AT91_UDP_ESR;
+		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
+		goto succeed;
+
+	/*
+	 * Interfaces have no feature settings; this is pretty useless.
+	 * we won't even insist the interface exists...
+	 */
+	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
+			| USB_REQ_GET_STATUS:
+		PACKET("get interface status\n");
+		__raw_writeb(0, dreg);
+		__raw_writeb(0, dreg);
+		goto write_in;
+		/* then STATUS starts later, automatically */
+	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
+			| USB_REQ_SET_FEATURE:
+	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
+			| USB_REQ_CLEAR_FEATURE:
+		goto stall;
+
+	/*
+	 * Hosts may clear bulk/intr endpoint halt after the gadget
+	 * driver sets it (not widely used); or set it (for testing)
+	 */
+	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
+			| USB_REQ_GET_STATUS:
+		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
+		ep = &udc->ep[tmp];
+		if (tmp >= NUM_ENDPOINTS || (tmp && !ep->ep.desc))
+			goto stall;
+
+		if (tmp) {
+			if ((w_index & USB_DIR_IN)) {
+				if (!ep->is_in)
+					goto stall;
+			} else if (ep->is_in)
+				goto stall;
+		}
+		PACKET("get %s status\n", ep->ep.name);
+		if (__raw_readl(ep->creg) & AT91_UDP_FORCESTALL)
+			tmp = (1 << USB_ENDPOINT_HALT);
+		else
+			tmp = 0;
+		__raw_writeb(tmp, dreg);
+		__raw_writeb(0, dreg);
+		goto write_in;
+		/* then STATUS starts later, automatically */
+	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
+			| USB_REQ_SET_FEATURE:
+		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
+		ep = &udc->ep[tmp];
+		if (w_value != USB_ENDPOINT_HALT || tmp >= NUM_ENDPOINTS)
+			goto stall;
+		if (!ep->ep.desc || ep->is_iso)
+			goto stall;
+		if ((w_index & USB_DIR_IN)) {
+			if (!ep->is_in)
+				goto stall;
+		} else if (ep->is_in)
+			goto stall;
+
+		tmp = __raw_readl(ep->creg);
+		tmp &= ~SET_FX;
+		tmp |= CLR_FX | AT91_UDP_FORCESTALL;
+		__raw_writel(tmp, ep->creg);
+		goto succeed;
+	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
+			| USB_REQ_CLEAR_FEATURE:
+		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
+		ep = &udc->ep[tmp];
+		if (w_value != USB_ENDPOINT_HALT || tmp >= NUM_ENDPOINTS)
+			goto stall;
+		if (tmp == 0)
+			goto succeed;
+		if (!ep->ep.desc || ep->is_iso)
+			goto stall;
+		if ((w_index & USB_DIR_IN)) {
+			if (!ep->is_in)
+				goto stall;
+		} else if (ep->is_in)
+			goto stall;
+
+		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
+		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
+		tmp = __raw_readl(ep->creg);
+		tmp |= CLR_FX;
+		tmp &= ~(SET_FX | AT91_UDP_FORCESTALL);
+		__raw_writel(tmp, ep->creg);
+		if (!list_empty(&ep->queue))
+			handle_ep(ep);
+		goto succeed;
+	}
+
+#undef w_value
+#undef w_index
+#undef w_length
+
+	/* pass request up to the gadget driver */
+	if (udc->driver) {
+		spin_unlock(&udc->lock);
+		status = udc->driver->setup(&udc->gadget, &pkt.r);
+		spin_lock(&udc->lock);
+	}
+	else
+		status = -ENODEV;
+	if (status < 0) {
+stall:
+		VDBG("req %02x.%02x protocol STALL; stat %d\n",
+				pkt.r.bRequestType, pkt.r.bRequest, status);
+		csr |= AT91_UDP_FORCESTALL;
+		__raw_writel(csr, creg);
+		udc->req_pending = 0;
+	}
+	return;
+
+succeed:
+	/* immediate successful (IN) STATUS after zero length DATA */
+	PACKET("ep0 in/status\n");
+write_in:
+	csr |= AT91_UDP_TXPKTRDY;
+	__raw_writel(csr, creg);
+	udc->req_pending = 0;
+}
+
+static void handle_ep0(struct at91_udc *udc)
+{
+	struct at91_ep		*ep0 = &udc->ep[0];
+	u32 __iomem		*creg = ep0->creg;
+	u32			csr = __raw_readl(creg);
+	struct at91_request	*req;
+
+	if (unlikely(csr & AT91_UDP_STALLSENT)) {
+		nuke(ep0, -EPROTO);
+		udc->req_pending = 0;
+		csr |= CLR_FX;
+		csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_FORCESTALL);
+		__raw_writel(csr, creg);
+		VDBG("ep0 stalled\n");
+		csr = __raw_readl(creg);
+	}
+	if (csr & AT91_UDP_RXSETUP) {
+		nuke(ep0, 0);
+		udc->req_pending = 0;
+		handle_setup(udc, ep0, csr);
+		return;
+	}
+
+	if (list_empty(&ep0->queue))
+		req = NULL;
+	else
+		req = list_entry(ep0->queue.next, struct at91_request, queue);
+
+	/* host ACKed an IN packet that we sent */
+	if (csr & AT91_UDP_TXCOMP) {
+		csr |= CLR_FX;
+		csr &= ~(SET_FX | AT91_UDP_TXCOMP);
+
+		/* write more IN DATA? */
+		if (req && ep0->is_in) {
+			if (handle_ep(ep0))
+				udc->req_pending = 0;
+
+		/*
+		 * Ack after:
+		 *  - last IN DATA packet (including GET_STATUS)
+		 *  - IN/STATUS for OUT DATA
+		 *  - IN/STATUS for any zero-length DATA stage
+		 * except for the IN DATA case, the host should send
+		 * an OUT status later, which we'll ack.
+		 */
+		} else {
+			udc->req_pending = 0;
+			__raw_writel(csr, creg);
+
+			/*
+			 * SET_ADDRESS takes effect only after the STATUS
+			 * (to the original address) gets acked.
+			 */
+			if (udc->wait_for_addr_ack) {
+				u32	tmp;
+
+				at91_udp_write(udc, AT91_UDP_FADDR,
+						AT91_UDP_FEN | udc->addr);
+				tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
+				tmp &= ~AT91_UDP_FADDEN;
+				if (udc->addr)
+					tmp |= AT91_UDP_FADDEN;
+				at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
+
+				udc->wait_for_addr_ack = 0;
+				VDBG("address %d\n", udc->addr);
+			}
+		}
+	}
+
+	/* OUT packet arrived ... */
+	else if (csr & AT91_UDP_RX_DATA_BK0) {
+		csr |= CLR_FX;
+		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
+
+		/* OUT DATA stage */
+		if (!ep0->is_in) {
+			if (req) {
+				if (handle_ep(ep0)) {
+					/* send IN/STATUS */
+					PACKET("ep0 in/status\n");
+					csr = __raw_readl(creg);
+					csr &= ~SET_FX;
+					csr |= CLR_FX | AT91_UDP_TXPKTRDY;
+					__raw_writel(csr, creg);
+					udc->req_pending = 0;
+				}
+			} else if (udc->req_pending) {
+				/*
+				 * AT91 hardware has a hard time with this
+				 * "deferred response" mode for control-OUT
+				 * transfers.  (For control-IN it's fine.)
+				 *
+				 * The normal solution leaves OUT data in the
+				 * fifo until the gadget driver is ready.
+				 * We couldn't do that here without disabling
+				 * the IRQ that tells about SETUP packets,
+				 * e.g. when the host gets impatient...
+				 *
+				 * Working around it by copying into a buffer
+				 * would almost be a non-deferred response,
+				 * except that it wouldn't permit reliable
+				 * stalling of the request.  Instead, demand
+				 * that gadget drivers not use this mode.
+				 */
+				DBG("no control-OUT deferred responses!\n");
+				__raw_writel(csr | AT91_UDP_FORCESTALL, creg);
+				udc->req_pending = 0;
+			}
+
+		/* STATUS stage for control-IN; ack.  */
+		} else {
+			PACKET("ep0 out/status ACK\n");
+			__raw_writel(csr, creg);
+
+			/* "early" status stage */
+			if (req)
+				done(ep0, req, 0);
+		}
+	}
+}
+
+static irqreturn_t at91_udc_irq (int irq, void *_udc)
+{
+	struct at91_udc		*udc = _udc;
+	u32			rescans = 5;
+	int			disable_clock = 0;
+	unsigned long		flags;
+
+	spin_lock_irqsave(&udc->lock, flags);
+
+	if (!udc->clocked) {
+		clk_on(udc);
+		disable_clock = 1;
+	}
+
+	while (rescans--) {
+		u32 status;
+
+		status = at91_udp_read(udc, AT91_UDP_ISR)
+			& at91_udp_read(udc, AT91_UDP_IMR);
+		if (!status)
+			break;
+
+		/* USB reset irq:  not maskable */
+		if (status & AT91_UDP_ENDBUSRES) {
+			at91_udp_write(udc, AT91_UDP_IDR, ~MINIMUS_INTERRUPTUS);
+			at91_udp_write(udc, AT91_UDP_IER, MINIMUS_INTERRUPTUS);
+			/* Atmel code clears this irq twice */
+			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
+			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
+			VDBG("end bus reset\n");
+			udc->addr = 0;
+			reset_gadget(udc);
+
+			/* enable ep0 */
+			at91_udp_write(udc, AT91_UDP_CSR(0),
+					AT91_UDP_EPEDS | AT91_UDP_EPTYPE_CTRL);
+			udc->gadget.speed = USB_SPEED_FULL;
+			udc->suspended = 0;
+			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_EP(0));
+
+			/*
+			 * NOTE:  this driver keeps clocks off unless the
+			 * USB host is present.  That saves power, but for
+			 * boards that don't support VBUS detection, both
+			 * clocks need to be active most of the time.
+			 */
+
+		/* host initiated suspend (3+ms bus idle) */
+		} else if (status & AT91_UDP_RXSUSP) {
+			at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXSUSP);
+			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXRSM);
+			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXSUSP);
+			/* VDBG("bus suspend\n"); */
+			if (udc->suspended)
+				continue;
+			udc->suspended = 1;
+
+			/*
+			 * NOTE:  when suspending a VBUS-powered device, the
+			 * gadget driver should switch into slow clock mode
+			 * and then into standby to avoid drawing more than
+			 * 500uA power (2500uA for some high-power configs).
+			 */
+			if (udc->driver && udc->driver->suspend) {
+				spin_unlock(&udc->lock);
+				udc->driver->suspend(&udc->gadget);
+				spin_lock(&udc->lock);
+			}
+
+		/* host initiated resume */
+		} else if (status & AT91_UDP_RXRSM) {
+			at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
+			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXSUSP);
+			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
+			/* VDBG("bus resume\n"); */
+			if (!udc->suspended)
+				continue;
+			udc->suspended = 0;
+
+			/*
+			 * NOTE:  for a VBUS-powered device, the gadget driver
+			 * would normally want to switch out of slow clock
+			 * mode into normal mode.
+			 */
+			if (udc->driver && udc->driver->resume) {
+				spin_unlock(&udc->lock);
+				udc->driver->resume(&udc->gadget);
+				spin_lock(&udc->lock);
+			}
+
+		/* endpoint IRQs are cleared by handling them */
+		} else {
+			int		i;
+			unsigned	mask = 1;
+			struct at91_ep	*ep = &udc->ep[1];
+
+			if (status & mask)
+				handle_ep0(udc);
+			for (i = 1; i < NUM_ENDPOINTS; i++) {
+				mask <<= 1;
+				if (status & mask)
+					handle_ep(ep);
+				ep++;
+			}
+		}
+	}
+
+	if (disable_clock)
+		clk_off(udc);
+
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	return IRQ_HANDLED;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void at91_vbus_update(struct at91_udc *udc, unsigned value)
+{
+	value ^= udc->board.vbus_active_low;
+	if (value != udc->vbus)
+		at91_vbus_session(&udc->gadget, value);
+}
+
+static irqreturn_t at91_vbus_irq(int irq, void *_udc)
+{
+	struct at91_udc	*udc = _udc;
+
+	/* vbus needs at least brief debouncing */
+	udelay(10);
+	at91_vbus_update(udc, gpio_get_value(udc->board.vbus_pin));
+
+	return IRQ_HANDLED;
+}
+
+static void at91_vbus_timer_work(struct work_struct *work)
+{
+	struct at91_udc *udc = container_of(work, struct at91_udc,
+					    vbus_timer_work);
+
+	at91_vbus_update(udc, gpio_get_value_cansleep(udc->board.vbus_pin));
+
+	if (!timer_pending(&udc->vbus_timer))
+		mod_timer(&udc->vbus_timer, jiffies + VBUS_POLL_TIMEOUT);
+}
+
+static void at91_vbus_timer(unsigned long data)
+{
+	struct at91_udc *udc = (struct at91_udc *)data;
+
+	/*
+	 * If we are polling vbus it is likely that the gpio is on an
+	 * bus such as i2c or spi which may sleep, so schedule some work
+	 * to read the vbus gpio
+	 */
+	schedule_work(&udc->vbus_timer_work);
+}
+
+static int at91_start(struct usb_gadget *gadget,
+		struct usb_gadget_driver *driver)
+{
+	struct at91_udc	*udc;
+
+	udc = container_of(gadget, struct at91_udc, gadget);
+	udc->driver = driver;
+	udc->gadget.dev.of_node = udc->pdev->dev.of_node;
+	udc->enabled = 1;
+	udc->gadget.is_selfpowered = 1;
+
+	return 0;
+}
+
+static int at91_stop(struct usb_gadget *gadget)
+{
+	struct at91_udc *udc;
+	unsigned long	flags;
+
+	udc = container_of(gadget, struct at91_udc, gadget);
+	spin_lock_irqsave(&udc->lock, flags);
+	udc->enabled = 0;
+	at91_udp_write(udc, AT91_UDP_IDR, ~0);
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	udc->driver = NULL;
+
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static void at91udc_shutdown(struct platform_device *dev)
+{
+	struct at91_udc *udc = platform_get_drvdata(dev);
+	unsigned long	flags;
+
+	/* force disconnect on reboot */
+	spin_lock_irqsave(&udc->lock, flags);
+	pullup(platform_get_drvdata(dev), 0);
+	spin_unlock_irqrestore(&udc->lock, flags);
+}
+
+static int at91rm9200_udc_init(struct at91_udc *udc)
+{
+	struct at91_ep *ep;
+	int ret;
+	int i;
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+
+		switch (i) {
+		case 0:
+		case 3:
+			ep->maxpacket = 8;
+			break;
+		case 1 ... 2:
+			ep->maxpacket = 64;
+			break;
+		case 4 ... 5:
+			ep->maxpacket = 256;
+			break;
+		}
+	}
+
+	if (!gpio_is_valid(udc->board.pullup_pin)) {
+		DBG("no D+ pullup?\n");
+		return -ENODEV;
+	}
+
+	ret = devm_gpio_request(&udc->pdev->dev, udc->board.pullup_pin,
+				"udc_pullup");
+	if (ret) {
+		DBG("D+ pullup is busy\n");
+		return ret;
+	}
+
+	gpio_direction_output(udc->board.pullup_pin,
+			      udc->board.pullup_active_low);
+
+	return 0;
+}
+
+static void at91rm9200_udc_pullup(struct at91_udc *udc, int is_on)
+{
+	int active = !udc->board.pullup_active_low;
+
+	if (is_on)
+		gpio_set_value(udc->board.pullup_pin, active);
+	else
+		gpio_set_value(udc->board.pullup_pin, !active);
+}
+
+static const struct at91_udc_caps at91rm9200_udc_caps = {
+	.init = at91rm9200_udc_init,
+	.pullup = at91rm9200_udc_pullup,
+};
+
+static int at91sam9260_udc_init(struct at91_udc *udc)
+{
+	struct at91_ep *ep;
+	int i;
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+
+		switch (i) {
+		case 0 ... 3:
+			ep->maxpacket = 64;
+			break;
+		case 4 ... 5:
+			ep->maxpacket = 512;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static void at91sam9260_udc_pullup(struct at91_udc *udc, int is_on)
+{
+	u32 txvc = at91_udp_read(udc, AT91_UDP_TXVC);
+
+	if (is_on)
+		txvc |= AT91_UDP_TXVC_PUON;
+	else
+		txvc &= ~AT91_UDP_TXVC_PUON;
+
+	at91_udp_write(udc, AT91_UDP_TXVC, txvc);
+}
+
+static const struct at91_udc_caps at91sam9260_udc_caps = {
+	.init = at91sam9260_udc_init,
+	.pullup = at91sam9260_udc_pullup,
+};
+
+static int at91sam9261_udc_init(struct at91_udc *udc)
+{
+	struct at91_ep *ep;
+	int i;
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+
+		switch (i) {
+		case 0:
+			ep->maxpacket = 8;
+			break;
+		case 1 ... 3:
+			ep->maxpacket = 64;
+			break;
+		case 4 ... 5:
+			ep->maxpacket = 256;
+			break;
+		}
+	}
+
+	udc->matrix = syscon_regmap_lookup_by_phandle(udc->pdev->dev.of_node,
+						      "atmel,matrix");
+	if (IS_ERR(udc->matrix))
+		return PTR_ERR(udc->matrix);
+
+	return 0;
+}
+
+static void at91sam9261_udc_pullup(struct at91_udc *udc, int is_on)
+{
+	u32 usbpucr = 0;
+
+	if (is_on)
+		usbpucr = AT91_MATRIX_USBPUCR_PUON;
+
+	regmap_update_bits(udc->matrix, AT91SAM9261_MATRIX_USBPUCR,
+			   AT91_MATRIX_USBPUCR_PUON, usbpucr);
+}
+
+static const struct at91_udc_caps at91sam9261_udc_caps = {
+	.init = at91sam9261_udc_init,
+	.pullup = at91sam9261_udc_pullup,
+};
+
+static int at91sam9263_udc_init(struct at91_udc *udc)
+{
+	struct at91_ep *ep;
+	int i;
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+
+		switch (i) {
+		case 0:
+		case 1:
+		case 2:
+		case 3:
+			ep->maxpacket = 64;
+			break;
+		case 4:
+		case 5:
+			ep->maxpacket = 256;
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static const struct at91_udc_caps at91sam9263_udc_caps = {
+	.init = at91sam9263_udc_init,
+	.pullup = at91sam9260_udc_pullup,
+};
+
+static const struct of_device_id at91_udc_dt_ids[] = {
+	{
+		.compatible = "atmel,at91rm9200-udc",
+		.data = &at91rm9200_udc_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9260-udc",
+		.data = &at91sam9260_udc_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9261-udc",
+		.data = &at91sam9261_udc_caps,
+	},
+	{
+		.compatible = "atmel,at91sam9263-udc",
+		.data = &at91sam9263_udc_caps,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, at91_udc_dt_ids);
+
+static void at91udc_of_init(struct at91_udc *udc, struct device_node *np)
+{
+	struct at91_udc_data *board = &udc->board;
+	const struct of_device_id *match;
+	enum of_gpio_flags flags;
+	u32 val;
+
+	if (of_property_read_u32(np, "atmel,vbus-polled", &val) == 0)
+		board->vbus_polled = 1;
+
+	board->vbus_pin = of_get_named_gpio_flags(np, "atmel,vbus-gpio", 0,
+						  &flags);
+	board->vbus_active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
+
+	board->pullup_pin = of_get_named_gpio_flags(np, "atmel,pullup-gpio", 0,
+						  &flags);
+
+	board->pullup_active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
+
+	match = of_match_node(at91_udc_dt_ids, np);
+	if (match)
+		udc->caps = match->data;
+}
+
+static int at91udc_probe(struct platform_device *pdev)
+{
+	struct device	*dev = &pdev->dev;
+	struct at91_udc	*udc;
+	int		retval;
+	struct resource	*res;
+	struct at91_ep	*ep;
+	int		i;
+
+	udc = devm_kzalloc(dev, sizeof(*udc), GFP_KERNEL);
+	if (!udc)
+		return -ENOMEM;
+
+	/* init software state */
+	udc->gadget.dev.parent = dev;
+	at91udc_of_init(udc, pdev->dev.of_node);
+	udc->pdev = pdev;
+	udc->enabled = 0;
+	spin_lock_init(&udc->lock);
+
+	udc->gadget.ops = &at91_udc_ops;
+	udc->gadget.ep0 = &udc->ep[0].ep;
+	udc->gadget.name = driver_name;
+	udc->gadget.dev.init_name = "gadget";
+
+	for (i = 0; i < NUM_ENDPOINTS; i++) {
+		ep = &udc->ep[i];
+		ep->ep.name = ep_names[i];
+		ep->ep.ops = &at91_ep_ops;
+		ep->udc = udc;
+		ep->int_mask = BIT(i);
+		if (i != 0 && i != 3)
+			ep->is_pingpong = 1;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	udc->udp_baseaddr = devm_ioremap_resource(dev, res);
+	if (IS_ERR(udc->udp_baseaddr))
+		return PTR_ERR(udc->udp_baseaddr);
+
+	if (udc->caps && udc->caps->init) {
+		retval = udc->caps->init(udc);
+		if (retval)
+			return retval;
+	}
+
+	udc_reinit(udc);
+
+	/* get interface and function clocks */
+	udc->iclk = devm_clk_get(dev, "pclk");
+	if (IS_ERR(udc->iclk))
+		return PTR_ERR(udc->iclk);
+
+	udc->fclk = devm_clk_get(dev, "hclk");
+	if (IS_ERR(udc->fclk))
+		return PTR_ERR(udc->fclk);
+
+	/* don't do anything until we have both gadget driver and VBUS */
+	clk_set_rate(udc->fclk, 48000000);
+	retval = clk_prepare(udc->fclk);
+	if (retval)
+		return retval;
+
+	retval = clk_prepare_enable(udc->iclk);
+	if (retval)
+		goto err_unprepare_fclk;
+
+	at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
+	at91_udp_write(udc, AT91_UDP_IDR, 0xffffffff);
+	/* Clear all pending interrupts - UDP may be used by bootloader. */
+	at91_udp_write(udc, AT91_UDP_ICR, 0xffffffff);
+	clk_disable(udc->iclk);
+
+	/* request UDC and maybe VBUS irqs */
+	udc->udp_irq = platform_get_irq(pdev, 0);
+	retval = devm_request_irq(dev, udc->udp_irq, at91_udc_irq, 0,
+				  driver_name, udc);
+	if (retval) {
+		DBG("request irq %d failed\n", udc->udp_irq);
+		goto err_unprepare_iclk;
+	}
+
+	if (gpio_is_valid(udc->board.vbus_pin)) {
+		retval = devm_gpio_request(dev, udc->board.vbus_pin,
+					   "udc_vbus");
+		if (retval) {
+			DBG("request vbus pin failed\n");
+			goto err_unprepare_iclk;
+		}
+
+		gpio_direction_input(udc->board.vbus_pin);
+
+		/*
+		 * Get the initial state of VBUS - we cannot expect
+		 * a pending interrupt.
+		 */
+		udc->vbus = gpio_get_value_cansleep(udc->board.vbus_pin) ^
+			udc->board.vbus_active_low;
+
+		if (udc->board.vbus_polled) {
+			INIT_WORK(&udc->vbus_timer_work, at91_vbus_timer_work);
+			setup_timer(&udc->vbus_timer, at91_vbus_timer,
+				    (unsigned long)udc);
+			mod_timer(&udc->vbus_timer,
+				  jiffies + VBUS_POLL_TIMEOUT);
+		} else {
+			retval = devm_request_irq(dev,
+					gpio_to_irq(udc->board.vbus_pin),
+					at91_vbus_irq, 0, driver_name, udc);
+			if (retval) {
+				DBG("request vbus irq %d failed\n",
+				    udc->board.vbus_pin);
+				goto err_unprepare_iclk;
+			}
+		}
+	} else {
+		DBG("no VBUS detection, assuming always-on\n");
+		udc->vbus = 1;
+	}
+	retval = usb_add_gadget_udc(dev, &udc->gadget);
+	if (retval)
+		goto err_unprepare_iclk;
+	dev_set_drvdata(dev, udc);
+	device_init_wakeup(dev, 1);
+	create_debug_file(udc);
+
+	INFO("%s version %s\n", driver_name, DRIVER_VERSION);
+	return 0;
+
+err_unprepare_iclk:
+	clk_unprepare(udc->iclk);
+err_unprepare_fclk:
+	clk_unprepare(udc->fclk);
+
+	DBG("%s probe failed, %d\n", driver_name, retval);
+
+	return retval;
+}
+
+static int at91udc_remove(struct platform_device *pdev)
+{
+	struct at91_udc *udc = platform_get_drvdata(pdev);
+	unsigned long	flags;
+
+	DBG("remove\n");
+
+	usb_del_gadget_udc(&udc->gadget);
+	if (udc->driver)
+		return -EBUSY;
+
+	spin_lock_irqsave(&udc->lock, flags);
+	pullup(udc, 0);
+	spin_unlock_irqrestore(&udc->lock, flags);
+
+	device_init_wakeup(&pdev->dev, 0);
+	remove_debug_file(udc);
+	clk_unprepare(udc->fclk);
+	clk_unprepare(udc->iclk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int at91udc_suspend(struct platform_device *pdev, pm_message_t mesg)
+{
+	struct at91_udc *udc = platform_get_drvdata(pdev);
+	int		wake = udc->driver && device_may_wakeup(&pdev->dev);
+	unsigned long	flags;
+
+	/* Unless we can act normally to the host (letting it wake us up
+	 * whenever it has work for us) force disconnect.  Wakeup requires
+	 * PLLB for USB events (signaling for reset, wakeup, or incoming
+	 * tokens) and VBUS irqs (on systems which support them).
+	 */
+	if ((!udc->suspended && udc->addr)
+			|| !wake
+			|| at91_suspend_entering_slow_clock()) {
+		spin_lock_irqsave(&udc->lock, flags);
+		pullup(udc, 0);
+		wake = 0;
+		spin_unlock_irqrestore(&udc->lock, flags);
+	} else
+		enable_irq_wake(udc->udp_irq);
+
+	udc->active_suspend = wake;
+	if (gpio_is_valid(udc->board.vbus_pin) && !udc->board.vbus_polled && wake)
+		enable_irq_wake(udc->board.vbus_pin);
+	return 0;
+}
+
+static int at91udc_resume(struct platform_device *pdev)
+{
+	struct at91_udc *udc = platform_get_drvdata(pdev);
+	unsigned long	flags;
+
+	if (gpio_is_valid(udc->board.vbus_pin) && !udc->board.vbus_polled &&
+	    udc->active_suspend)
+		disable_irq_wake(udc->board.vbus_pin);
+
+	/* maybe reconnect to host; if so, clocks on */
+	if (udc->active_suspend)
+		disable_irq_wake(udc->udp_irq);
+	else {
+		spin_lock_irqsave(&udc->lock, flags);
+		pullup(udc, 1);
+		spin_unlock_irqrestore(&udc->lock, flags);
+	}
+	return 0;
+}
+#else
+#define	at91udc_suspend	NULL
+#define	at91udc_resume	NULL
+#endif
+
+static struct platform_driver at91_udc_driver = {
+	.remove		= at91udc_remove,
+	.shutdown	= at91udc_shutdown,
+	.suspend	= at91udc_suspend,
+	.resume		= at91udc_resume,
+	.driver		= {
+		.name	= (char *) driver_name,
+		.of_match_table	= at91_udc_dt_ids,
+	},
+};
+
+module_platform_driver_probe(at91_udc_driver, at91udc_probe);
+
+MODULE_DESCRIPTION("AT91 udc driver");
+MODULE_AUTHOR("Thomas Rathbone, David Brownell");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:at91_udc");
diff --git a/drivers/usb/gadget/at91_udc.h b/drivers/usb/gadget/at91_udc.h
new file mode 100644
index 00000000000..2679c8b217c
--- /dev/null
+++ b/drivers/usb/gadget/at91_udc.h
@@ -0,0 +1,175 @@
+/*
+ * Copyright (C) 2004 by Thomas Rathbone, HP Labs
+ * Copyright (C) 2005 by Ivan Kokshaysky
+ * Copyright (C) 2006 by SAN People
+ *
+ * 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.
+ */
+
+#ifndef AT91_UDC_H
+#define AT91_UDC_H
+
+/*
+ * USB Device Port (UDP) registers.
+ * Based on AT91RM9200 datasheet revision E.
+ */
+
+#define AT91_UDP_FRM_NUM	0x00		/* Frame Number Register */
+#define     AT91_UDP_NUM	(0x7ff <<  0)	/* Frame Number */
+#define     AT91_UDP_FRM_ERR	(1     << 16)	/* Frame Error */
+#define     AT91_UDP_FRM_OK	(1     << 17)	/* Frame OK */
+
+#define AT91_UDP_GLB_STAT	0x04		/* Global State Register */
+#define     AT91_UDP_FADDEN	(1 <<  0)	/* Function Address Enable */
+#define     AT91_UDP_CONFG	(1 <<  1)	/* Configured */
+#define     AT91_UDP_ESR	(1 <<  2)	/* Enable Send Resume */
+#define     AT91_UDP_RSMINPR	(1 <<  3)	/* Resume has been sent */
+#define     AT91_UDP_RMWUPE	(1 <<  4)	/* Remote Wake Up Enable */
+
+#define AT91_UDP_FADDR		0x08		/* Function Address Register */
+#define     AT91_UDP_FADD	(0x7f << 0)	/* Function Address Value */
+#define     AT91_UDP_FEN	(1    << 8)	/* Function Enable */
+
+#define AT91_UDP_IER		0x10		/* Interrupt Enable Register */
+#define AT91_UDP_IDR		0x14		/* Interrupt Disable Register */
+#define AT91_UDP_IMR		0x18		/* Interrupt Mask Register */
+
+#define AT91_UDP_ISR		0x1c		/* Interrupt Status Register */
+#define     AT91_UDP_EP(n)	(1 << (n))	/* Endpoint Interrupt Status */
+#define     AT91_UDP_RXSUSP	(1 <<  8) 	/* USB Suspend Interrupt Status */
+#define     AT91_UDP_RXRSM	(1 <<  9)	/* USB Resume Interrupt Status */
+#define     AT91_UDP_EXTRSM	(1 << 10)	/* External Resume Interrupt Status [AT91RM9200 only] */
+#define     AT91_UDP_SOFINT	(1 << 11)	/* Start of Frame Interrupt Status */
+#define     AT91_UDP_ENDBUSRES	(1 << 12)	/* End of Bus Reset Interrupt Status */
+#define     AT91_UDP_WAKEUP	(1 << 13)	/* USB Wakeup Interrupt Status [AT91RM9200 only] */
+
+#define AT91_UDP_ICR		0x20		/* Interrupt Clear Register */
+#define AT91_UDP_RST_EP		0x28		/* Reset Endpoint Register */
+
+#define AT91_UDP_CSR(n)		(0x30+((n)*4))	/* Endpoint Control/Status Registers 0-7 */
+#define     AT91_UDP_TXCOMP	(1 <<  0)	/* Generates IN packet with data previously written in DPR */
+#define     AT91_UDP_RX_DATA_BK0 (1 <<  1)	/* Receive Data Bank 0 */
+#define     AT91_UDP_RXSETUP	(1 <<  2)	/* Send STALL to the host */
+#define     AT91_UDP_STALLSENT	(1 <<  3)	/* Stall Sent / Isochronous error (Isochronous endpoints) */
+#define     AT91_UDP_TXPKTRDY	(1 <<  4)	/* Transmit Packet Ready */
+#define     AT91_UDP_FORCESTALL	(1 <<  5)	/* Force Stall */
+#define     AT91_UDP_RX_DATA_BK1 (1 <<  6)	/* Receive Data Bank 1 */
+#define     AT91_UDP_DIR	(1 <<  7)	/* Transfer Direction */
+#define     AT91_UDP_EPTYPE	(7 <<  8)	/* Endpoint Type */
+#define		AT91_UDP_EPTYPE_CTRL		(0 <<  8)
+#define		AT91_UDP_EPTYPE_ISO_OUT		(1 <<  8)
+#define		AT91_UDP_EPTYPE_BULK_OUT	(2 <<  8)
+#define		AT91_UDP_EPTYPE_INT_OUT		(3 <<  8)
+#define		AT91_UDP_EPTYPE_ISO_IN		(5 <<  8)
+#define		AT91_UDP_EPTYPE_BULK_IN		(6 <<  8)
+#define		AT91_UDP_EPTYPE_INT_IN		(7 <<  8)
+#define     AT91_UDP_DTGLE	(1 << 11)	/* Data Toggle */
+#define     AT91_UDP_EPEDS	(1 << 15)	/* Endpoint Enable/Disable */
+#define     AT91_UDP_RXBYTECNT	(0x7ff << 16)	/* Number of bytes in FIFO */
+
+#define AT91_UDP_FDR(n)		(0x50+((n)*4))	/* Endpoint FIFO Data Registers 0-7 */
+
+#define AT91_UDP_TXVC		0x74		/* Transceiver Control Register */
+#define     AT91_UDP_TXVC_TXVDIS (1 << 8)	/* Transceiver Disable */
+#define     AT91_UDP_TXVC_PUON   (1 << 9)	/* PullUp On [AT91SAM9260 only] */
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * controller driver data structures
+ */
+
+#define	NUM_ENDPOINTS	6
+
+/*
+ * hardware won't disable bus reset, or resume while the controller
+ * is suspended ... watching suspend helps keep the logic symmetric.
+ */
+#define	MINIMUS_INTERRUPTUS \
+	(AT91_UDP_ENDBUSRES | AT91_UDP_RXRSM | AT91_UDP_RXSUSP)
+
+struct at91_ep {
+	struct usb_ep			ep;
+	struct list_head		queue;
+	struct at91_udc			*udc;
+	void __iomem			*creg;
+
+	unsigned			maxpacket:16;
+	u8				int_mask;
+	unsigned			is_pingpong:1;
+
+	unsigned			stopped:1;
+	unsigned			is_in:1;
+	unsigned			is_iso:1;
+	unsigned			fifo_bank:1;
+};
+
+struct at91_udc_caps {
+	int (*init)(struct at91_udc *udc);
+	void (*pullup)(struct at91_udc *udc, int is_on);
+};
+
+/*
+ * driver is non-SMP, and just blocks IRQs whenever it needs
+ * access protection for chip registers or driver state
+ */
+struct at91_udc {
+	struct usb_gadget		gadget;
+	struct at91_ep			ep[NUM_ENDPOINTS];
+	struct usb_gadget_driver	*driver;
+	const struct at91_udc_caps	*caps;
+	unsigned			vbus:1;
+	unsigned			enabled:1;
+	unsigned			clocked:1;
+	unsigned			suspended:1;
+	unsigned			req_pending:1;
+	unsigned			wait_for_addr_ack:1;
+	unsigned			wait_for_config_ack:1;
+	unsigned			active_suspend:1;
+	u8				addr;
+	struct at91_udc_data		board;
+	struct clk			*iclk, *fclk;
+	struct platform_device		*pdev;
+	struct proc_dir_entry		*pde;
+	void __iomem			*udp_baseaddr;
+	int				udp_irq;
+	spinlock_t			lock;
+	struct timer_list		vbus_timer;
+	struct work_struct		vbus_timer_work;
+	struct regmap			*matrix;
+};
+
+static inline struct at91_udc *to_udc(struct usb_gadget *g)
+{
+	return container_of(g, struct at91_udc, gadget);
+}
+
+struct at91_request {
+	struct usb_request		req;
+	struct list_head		queue;
+};
+
+/*-------------------------------------------------------------------------*/
+
+#ifdef VERBOSE_DEBUG
+#    define VDBG		DBG
+#else
+#    define VDBG(stuff...)	do{}while(0)
+#endif
+
+#ifdef PACKET_TRACE
+#    define PACKET		VDBG
+#else
+#    define PACKET(stuff...)	do{}while(0)
+#endif
+
+#define ERR(stuff...)		pr_err("udc: " stuff)
+#define WARNING(stuff...)	pr_warning("udc: " stuff)
+#define INFO(stuff...)		pr_info("udc: " stuff)
+#define DBG(stuff...)		pr_debug("udc: " stuff)
+
+#endif
+