pxa25x: Add support for USB ethernet gadget

Add to pxa25x based devices support for USB ethernet gadget. This is a
port of pxa25x UDC driver from Linux kernel.

Signed-off-by: Lukasz Dalek <luk0104@gmail.com>

1 files changed, 2059 insertions, 0 deletions

diff --git a/drivers/usb/gadget/pxa25x_udc.c b/drivers/usb/gadget/pxa25x_udc.c
new file mode 100644
index 0000000000..dd741439ae
--- /dev/null
+++ b/drivers/usb/gadget/pxa25x_udc.c
@@ -0,0 +1,2059 @@
+/*
+ * Intel PXA25x and IXP4xx on-chip full speed USB device controllers
+ *
+ * Copyright (C) 2002 Intrinsyc, Inc. (Frank Becker)
+ * Copyright (C) 2003 Robert Schwebel, Pengutronix
+ * Copyright (C) 2003 Benedikt Spranger, Pengutronix
+ * Copyright (C) 2003 David Brownell
+ * Copyright (C) 2003 Joshua Wise
+ * Copyright (C) 2012 Lukasz Dalek <luk0104@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * 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
+ *
+ * MODULE_AUTHOR("Frank Becker, Robert Schwebel, David Brownell");
+ */
+
+#define CONFIG_USB_PXA25X_SMALL
+#define DRIVER_NAME "pxa25x_udc_linux"
+#define ARCH_HAS_PREFETCH
+
+#include <common.h>
+#include <errno.h>
+#include <asm/byteorder.h>
+#include <asm/system.h>
+#include <asm/mach-types.h>
+#include <asm/unaligned.h>
+#include <linux/compat.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/arch/pxa.h>
+
+#include <usbdescriptors.h>
+#include <linux/usb/ch9.h>
+#include <linux/usb/gadget.h>
+#include <usb/lin_gadget_compat.h>
+#include <asm/arch/pxa-regs.h>
+
+#include "pxa25x_udc.h"
+
+/*
+ * This driver handles the USB Device Controller (UDC) in Intel's PXA 25x
+ * series processors.  The UDC for the IXP 4xx series is very similar.
+ * There are fifteen endpoints, in addition to ep0.
+ *
+ * Such controller drivers work with a gadget driver.  The gadget driver
+ * returns descriptors, implements configuration and data protocols used
+ * by the host to interact with this device, and allocates endpoints to
+ * the different protocol interfaces.  The controller driver virtualizes
+ * usb hardware so that the gadget drivers will be more portable.
+ *
+ * This UDC hardware wants to implement a bit too much USB protocol, so
+ * it constrains the sorts of USB configuration change events that work.
+ * The errata for these chips are misleading; some "fixed" bugs from
+ * pxa250 a0/a1 b0/b1/b2 sure act like they're still there.
+ *
+ * Note that the UDC hardware supports DMA (except on IXP) but that's
+ * not used here.  IN-DMA (to host) is simple enough, when the data is
+ * suitably aligned (16 bytes) ... the network stack doesn't do that,
+ * other software can.  OUT-DMA is buggy in most chip versions, as well
+ * as poorly designed (data toggle not automatic).  So this driver won't
+ * bother using DMA.  (Mostly-working IN-DMA support was available in
+ * kernels before 2.6.23, but was never enabled or well tested.)
+ */
+
+#define DRIVER_VERSION	"18-August-2012"
+#define DRIVER_DESC	"PXA 25x USB Device Controller driver"
+
+static const char driver_name[] = "pxa25x_udc";
+static const char ep0name[] = "ep0";
+
+/* Watchdog */
+static inline void start_watchdog(struct pxa25x_udc *udc)
+{
+	debug("Started watchdog\n");
+	udc->watchdog.base = get_timer(0);
+	udc->watchdog.running = 1;
+}
+
+static inline void stop_watchdog(struct pxa25x_udc *udc)
+{
+	udc->watchdog.running = 0;
+	debug("Stopped watchdog\n");
+}
+
+static inline void test_watchdog(struct pxa25x_udc *udc)
+{
+	if (!udc->watchdog.running)
+		return;
+
+	debug("watchdog %ld %ld\n", get_timer(udc->watchdog.base),
+		udc->watchdog.period);
+
+	if (get_timer(udc->watchdog.base) >= udc->watchdog.period) {
+		stop_watchdog(udc);
+		udc->watchdog.function(udc);
+	}
+}
+
+static void udc_watchdog(struct pxa25x_udc *dev)
+{
+	uint32_t udccs0 = readl(&dev->regs->udccs[0]);
+
+	debug("Fired up udc_watchdog\n");
+
+	local_irq_disable();
+	if (dev->ep0state == EP0_STALL
+			&& (udccs0 & UDCCS0_FST) == 0
+			&& (udccs0 & UDCCS0_SST) == 0) {
+		writel(UDCCS0_FST|UDCCS0_FTF, &dev->regs->udccs[0]);
+		debug("ep0 re-stall\n");
+		start_watchdog(dev);
+	}
+	local_irq_enable();
+}
+
+#ifdef DEBUG
+
+static const char * const state_name[] = {
+	"EP0_IDLE",
+	"EP0_IN_DATA_PHASE", "EP0_OUT_DATA_PHASE",
+	"EP0_END_XFER", "EP0_STALL"
+};
+
+static void
+dump_udccr(const char *label)
+{
+	u32 udccr = readl(&UDC_REGS->udccr);
+	debug("%s %02X =%s%s%s%s%s%s%s%s\n",
+		label, udccr,
+		(udccr & UDCCR_REM) ? " rem" : "",
+		(udccr & UDCCR_RSTIR) ? " rstir" : "",
+		(udccr & UDCCR_SRM) ? " srm" : "",
+		(udccr & UDCCR_SUSIR) ? " susir" : "",
+		(udccr & UDCCR_RESIR) ? " resir" : "",
+		(udccr & UDCCR_RSM) ? " rsm" : "",
+		(udccr & UDCCR_UDA) ? " uda" : "",
+		(udccr & UDCCR_UDE) ? " ude" : "");
+}
+
+static void
+dump_udccs0(const char *label)
+{
+	u32 udccs0 = readl(&UDC_REGS->udccs[0]);
+
+	debug("%s %s %02X =%s%s%s%s%s%s%s%s\n",
+		label, state_name[the_controller->ep0state], udccs0,
+		(udccs0 & UDCCS0_SA) ? " sa" : "",
+		(udccs0 & UDCCS0_RNE) ? " rne" : "",
+		(udccs0 & UDCCS0_FST) ? " fst" : "",
+		(udccs0 & UDCCS0_SST) ? " sst" : "",
+		(udccs0 & UDCCS0_DRWF) ? " dwrf" : "",
+		(udccs0 & UDCCS0_FTF) ? " ftf" : "",
+		(udccs0 & UDCCS0_IPR) ? " ipr" : "",
+		(udccs0 & UDCCS0_OPR) ? " opr" : "");
+}
+
+static void
+dump_state(struct pxa25x_udc *dev)
+{
+	u32 tmp;
+	unsigned i;
+
+	debug("%s, uicr %02X.%02X, usir %02X.%02x, ufnr %02X.%02X\n",
+		state_name[dev->ep0state],
+		readl(&UDC_REGS->uicr1), readl(&UDC_REGS->uicr0),
+		readl(&UDC_REGS->usir1), readl(&UDC_REGS->usir0),
+		readl(&UDC_REGS->ufnrh), readl(&UDC_REGS->ufnrl));
+	dump_udccr("udccr");
+	if (dev->has_cfr) {
+		tmp = readl(&UDC_REGS->udccfr);
+		debug("udccfr %02X =%s%s\n", tmp,
+			(tmp & UDCCFR_AREN) ? " aren" : "",
+			(tmp & UDCCFR_ACM) ? " acm" : "");
+	}
+
+	if (!dev->driver) {
+		debug("no gadget driver bound\n");
+		return;
+	} else
+		debug("ep0 driver '%s'\n", "ether");
+
+	dump_udccs0("udccs0");
+	debug("ep0 IN %lu/%lu, OUT %lu/%lu\n",
+		dev->stats.write.bytes, dev->stats.write.ops,
+		dev->stats.read.bytes, dev->stats.read.ops);
+
+	for (i = 1; i < PXA_UDC_NUM_ENDPOINTS; i++) {
+		if (dev->ep[i].desc == NULL)
+			continue;
+		debug("udccs%d = %02x\n", i, *dev->ep->reg_udccs);
+	}
+}
+
+#else /* DEBUG */
+
+static inline void dump_udccr(const char *label) { }
+static inline void dump_udccs0(const char *label) { }
+static inline void dump_state(struct pxa25x_udc *dev) { }
+
+#endif /* DEBUG */
+
+/*
+ * ---------------------------------------------------------------------------
+ *	endpoint related parts of the api to the usb controller hardware,
+ *	used by gadget driver; and the inner talker-to-hardware core.
+ * ---------------------------------------------------------------------------
+ */
+
+static void pxa25x_ep_fifo_flush(struct usb_ep *ep);
+static void nuke(struct pxa25x_ep *, int status);
+
+/* one GPIO should control a D+ pullup, so host sees this device (or not) */
+static void pullup_off(void)
+{
+	struct pxa2xx_udc_mach_info *mach = the_controller->mach;
+
+	if (mach->udc_command)
+		mach->udc_command(PXA2XX_UDC_CMD_DISCONNECT);
+}
+
+static void pullup_on(void)
+{
+	struct pxa2xx_udc_mach_info *mach = the_controller->mach;
+
+	if (mach->udc_command)
+		mach->udc_command(PXA2XX_UDC_CMD_CONNECT);
+}
+
+static void pio_irq_enable(int bEndpointAddress)
+{
+	bEndpointAddress &= 0xf;
+	if (bEndpointAddress < 8) {
+		clrbits_le32(&the_controller->regs->uicr0,
+			1 << bEndpointAddress);
+	} else {
+		bEndpointAddress -= 8;
+		clrbits_le32(&the_controller->regs->uicr1,
+			1 << bEndpointAddress);
+	}
+}
+
+static void pio_irq_disable(int bEndpointAddress)
+{
+	bEndpointAddress &= 0xf;
+	if (bEndpointAddress < 8) {
+		setbits_le32(&the_controller->regs->uicr0,
+			1 << bEndpointAddress);
+	} else {
+		bEndpointAddress -= 8;
+		setbits_le32(&the_controller->regs->uicr1,
+			1 << bEndpointAddress);
+	}
+}
+
+static inline void udc_set_mask_UDCCR(int mask)
+{
+	/*
+	 * The UDCCR reg contains mask and interrupt status bits,
+	 * so using '|=' isn't safe as it may ack an interrupt.
+	 */
+	const uint32_t mask_bits = UDCCR_REM | UDCCR_SRM | UDCCR_UDE;
+
+	mask &= mask_bits;
+	clrsetbits_le32(&the_controller->regs->udccr, ~mask_bits, mask);
+}
+
+static inline void udc_clear_mask_UDCCR(int mask)
+{
+	const uint32_t mask_bits = UDCCR_REM | UDCCR_SRM | UDCCR_UDE;
+
+	mask = ~mask & mask_bits;
+	clrbits_le32(&the_controller->regs->udccr, ~mask);
+}
+
+static inline void udc_ack_int_UDCCR(int mask)
+{
+	const uint32_t mask_bits = UDCCR_REM | UDCCR_SRM | UDCCR_UDE;
+
+	mask &= ~mask_bits;
+	clrsetbits_le32(&the_controller->regs->udccr, ~mask_bits, mask);
+}
+
+/*
+ * endpoint enable/disable
+ *
+ * we need to verify the descriptors used to enable endpoints.  since pxa25x
+ * endpoint configurations are fixed, and are pretty much always enabled,
+ * there's not a lot to manage here.
+ *
+ * because pxa25x can't selectively initialize bulk (or interrupt) endpoints,
+ * (resetting endpoint halt and toggle), SET_INTERFACE is unusable except
+ * for a single interface (with only the default altsetting) and for gadget
+ * drivers that don't halt endpoints (not reset by set_interface).  that also
+ * means that if you use ISO, you must violate the USB spec rule that all
+ * iso endpoints must be in non-default altsettings.
+ */
+static int pxa25x_ep_enable(struct usb_ep *_ep,
+		const struct usb_endpoint_descriptor *desc)
+{
+	struct pxa25x_ep *ep;
+	struct pxa25x_udc *dev;
+
+	ep = container_of(_ep, struct pxa25x_ep, ep);
+	if (!_ep || !desc || ep->desc || _ep->name == ep0name
+			|| desc->bDescriptorType != USB_DT_ENDPOINT
+			|| ep->bEndpointAddress != desc->bEndpointAddress
+			|| ep->fifo_size < le16_to_cpu(desc->wMaxPacketSize)) {
+		printf("%s, bad ep or descriptor\n", __func__);
+		return -EINVAL;
+	}
+
+	/* xfer types must match, except that interrupt ~= bulk */
+	if (ep->bmAttributes != desc->bmAttributes
+			&& ep->bmAttributes != USB_ENDPOINT_XFER_BULK
+			&& desc->bmAttributes != USB_ENDPOINT_XFER_INT) {
+		printf("%s, %s type mismatch\n", __func__, _ep->name);
+		return -EINVAL;
+	}
+
+	/* hardware _could_ do smaller, but driver doesn't */
+	if ((desc->bmAttributes == USB_ENDPOINT_XFER_BULK
+				&& le16_to_cpu(desc->wMaxPacketSize)
+						!= BULK_FIFO_SIZE)
+			|| !desc->wMaxPacketSize) {
+		printf("%s, bad %s maxpacket\n", __func__, _ep->name);
+		return -ERANGE;
+	}
+
+	dev = ep->dev;
+	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN) {
+		printf("%s, bogus device state\n", __func__);
+		return -ESHUTDOWN;
+	}
+
+	ep->desc = desc;
+	ep->stopped = 0;
+	ep->pio_irqs = 0;
+	ep->ep.maxpacket = le16_to_cpu(desc->wMaxPacketSize);
+
+	/* flush fifo (mostly for OUT buffers) */
+	pxa25x_ep_fifo_flush(_ep);
+
+	/* ... reset halt state too, if we could ... */
+
+	debug("enabled %s\n", _ep->name);
+	return 0;
+}
+
+static int pxa25x_ep_disable(struct usb_ep *_ep)
+{
+	struct pxa25x_ep *ep;
+	unsigned long flags;
+
+	ep = container_of(_ep, struct pxa25x_ep, ep);
+	if (!_ep || !ep->desc) {
+		printf("%s, %s not enabled\n", __func__,
+			_ep ? ep->ep.name : NULL);
+		return -EINVAL;
+	}
+	local_irq_save(flags);
+
+	nuke(ep, -ESHUTDOWN);
+
+	/* flush fifo (mostly for IN buffers) */
+	pxa25x_ep_fifo_flush(_ep);
+
+	ep->desc = NULL;
+	ep->stopped = 1;
+
+	local_irq_restore(flags);
+	debug("%s disabled\n", _ep->name);
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * for the pxa25x, these can just wrap kmalloc/kfree.  gadget drivers
+ * must still pass correctly initialized endpoints, since other controller
+ * drivers may care about how it's currently set up (dma issues etc).
+ */
+
+/*
+ *	pxa25x_ep_alloc_request - allocate a request data structure
+ */
+static struct usb_request *
+pxa25x_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
+{
+	struct pxa25x_request *req;
+
+	req = kzalloc(sizeof(*req), gfp_flags);
+	if (!req)
+		return NULL;
+
+	INIT_LIST_HEAD(&req->queue);
+	return &req->req;
+}
+
+
+/*
+ *	pxa25x_ep_free_request - deallocate a request data structure
+ */
+static void
+pxa25x_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct pxa25x_request	*req;
+
+	req = container_of(_req, struct pxa25x_request, req);
+	WARN_ON(!list_empty(&req->queue));
+	kfree(req);
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ *	done - retire a request; caller blocked irqs
+ */
+static void done(struct pxa25x_ep *ep, struct pxa25x_request *req, int status)
+{
+	unsigned stopped = ep->stopped;
+
+	list_del_init(&req->queue);
+
+	if (likely(req->req.status == -EINPROGRESS))
+		req->req.status = status;
+	else
+		status = req->req.status;
+
+	if (status && status != -ESHUTDOWN)
+		debug("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;
+	req->req.complete(&ep->ep, &req->req);
+	ep->stopped = stopped;
+}
+
+
+static inline void ep0_idle(struct pxa25x_udc *dev)
+{
+	dev->ep0state = EP0_IDLE;
+}
+
+static int
+write_packet(u32 *uddr, struct pxa25x_request *req, unsigned max)
+{
+	u8 *buf;
+	unsigned length, count;
+
+	debug("%s(): uddr %p\n", __func__, uddr);
+
+	buf = req->req.buf + req->req.actual;
+	prefetch(buf);
+
+	/* how big will this packet be? */
+	length = min(req->req.length - req->req.actual, max);
+	req->req.actual += length;
+
+	count = length;
+	while (likely(count--))
+		writeb(*buf++, uddr);
+
+	return length;
+}
+
+/*
+ * write to an IN endpoint fifo, as many packets as possible.
+ * irqs will use this to write the rest later.
+ * caller guarantees at least one packet buffer is ready (or a zlp).
+ */
+static int
+write_fifo(struct pxa25x_ep *ep, struct pxa25x_request *req)
+{
+	unsigned max;
+
+	max = le16_to_cpu(ep->desc->wMaxPacketSize);
+	do {
+		unsigned count;
+		int is_last, is_short;
+
+		count = write_packet(ep->reg_uddr, req, max);
+
+		/* last packet is usually short (or a zlp) */
+		if (unlikely(count != max))
+			is_last = is_short = 1;
+		else {
+			if (likely(req->req.length != req->req.actual)
+					|| req->req.zero)
+				is_last = 0;
+			else
+				is_last = 1;
+			/* interrupt/iso maxpacket may not fill the fifo */
+			is_short = unlikely(max < ep->fifo_size);
+		}
+
+		debug_cond(NOISY, "wrote %s %d bytes%s%s %d left %p\n",
+			ep->ep.name, count,
+			is_last ? "/L" : "", is_short ? "/S" : "",
+			req->req.length - req->req.actual, req);
+
+		/*
+		 * let loose that packet. maybe try writing another one,
+		 * double buffering might work.  TSP, TPC, and TFS
+		 * bit values are the same for all normal IN endpoints.
+		 */
+		writel(UDCCS_BI_TPC, ep->reg_udccs);
+		if (is_short)
+			writel(UDCCS_BI_TSP, ep->reg_udccs);
+
+		/* requests complete when all IN data is in the FIFO */
+		if (is_last) {
+			done(ep, req, 0);
+			if (list_empty(&ep->queue))
+				pio_irq_disable(ep->bEndpointAddress);
+			return 1;
+		}
+
+		/*
+		 * TODO experiment: how robust can fifo mode tweaking be?
+		 * double buffering is off in the default fifo mode, which
+		 * prevents TFS from being set here.
+		 */
+
+	} while (readl(ep->reg_udccs) & UDCCS_BI_TFS);
+	return 0;
+}
+
+/*
+ * caller asserts req->pending (ep0 irq status nyet cleared); starts
+ * ep0 data stage.  these chips want very simple state transitions.
+ */
+static inline
+void ep0start(struct pxa25x_udc *dev, u32 flags, const char *tag)
+{
+	writel(flags|UDCCS0_SA|UDCCS0_OPR, &dev->regs->udccs[0]);
+	writel(USIR0_IR0, &dev->regs->usir0);
+	dev->req_pending = 0;
+	debug_cond(NOISY, "%s() %s, udccs0: %02x/%02x usir: %X.%X\n",
+		__func__, tag, readl(&dev->regs->udccs[0]), flags,
+		readl(&dev->regs->usir1), readl(&dev->regs->usir0));
+}
+
+static int
+write_ep0_fifo(struct pxa25x_ep *ep, struct pxa25x_request *req)
+{
+	unsigned count;
+	int is_short;
+
+	count = write_packet(&ep->dev->regs->uddr0, req, EP0_FIFO_SIZE);
+	ep->dev->stats.write.bytes += count;
+
+	/* last packet "must be" short (or a zlp) */
+	is_short = (count != EP0_FIFO_SIZE);
+
+	debug_cond(NOISY, "ep0in %d bytes %d left %p\n", count,
+		req->req.length - req->req.actual, req);
+
+	if (unlikely(is_short)) {
+		if (ep->dev->req_pending)
+			ep0start(ep->dev, UDCCS0_IPR, "short IN");
+		else
+			writel(UDCCS0_IPR, &ep->dev->regs->udccs[0]);
+
+		count = req->req.length;
+		done(ep, req, 0);
+		ep0_idle(ep->dev);
+
+		/*
+		 * This seems to get rid of lost status irqs in some cases:
+		 * host responds quickly, or next request involves config
+		 * change automagic, or should have been hidden, or ...
+		 *
+		 * FIXME get rid of all udelays possible...
+		 */
+		if (count >= EP0_FIFO_SIZE) {
+			count = 100;
+			do {
+				if ((readl(&ep->dev->regs->udccs[0]) &
+				     UDCCS0_OPR) != 0) {
+					/* clear OPR, generate ack */
+					writel(UDCCS0_OPR,
+						&ep->dev->regs->udccs[0]);
+					break;
+				}
+				count--;
+				udelay(1);
+			} while (count);
+		}
+	} else if (ep->dev->req_pending)
+		ep0start(ep->dev, 0, "IN");
+
+	return is_short;
+}
+
+
+/*
+ * read_fifo -  unload packet(s) from the fifo we use for usb OUT
+ * transfers and put them into the request.  caller should have made
+ * sure there's at least one packet ready.
+ *
+ * returns true if the request completed because of short packet or the
+ * request buffer having filled (and maybe overran till end-of-packet).
+ */
+static int
+read_fifo(struct pxa25x_ep *ep, struct pxa25x_request *req)
+{
+	u32 udccs;
+	u8 *buf;
+	unsigned bufferspace, count, is_short;
+
+	for (;;) {
+		/*
+		 * make sure there's a packet in the FIFO.
+		 * UDCCS_{BO,IO}_RPC are all the same bit value.
+		 * UDCCS_{BO,IO}_RNE are all the same bit value.
+		 */
+		udccs = readl(ep->reg_udccs);
+		if (unlikely((udccs & UDCCS_BO_RPC) == 0))
+			break;
+		buf = req->req.buf + req->req.actual;
+		prefetchw(buf);
+		bufferspace = req->req.length - req->req.actual;
+
+		/* read all bytes from this packet */
+		if (likely(udccs & UDCCS_BO_RNE)) {
+			count = 1 + (0x0ff & readl(ep->reg_ubcr));
+			req->req.actual += min(count, bufferspace);
+		} else /* zlp */
+			count = 0;
+		is_short = (count < ep->ep.maxpacket);
+		debug_cond(NOISY, "read %s %02x, %d bytes%s req %p %d/%d\n",
+			ep->ep.name, udccs, count,
+			is_short ? "/S" : "",
+			req, req->req.actual, req->req.length);
+		while (likely(count-- != 0)) {
+			u8 byte = readb(ep->reg_uddr);
+
+			if (unlikely(bufferspace == 0)) {
+				/*
+				 * this happens when the driver's buffer
+				 * is smaller than what the host sent.
+				 * discard the extra data.
+				 */
+				if (req->req.status != -EOVERFLOW)
+					printf("%s overflow %d\n",
+						ep->ep.name, count);
+				req->req.status = -EOVERFLOW;
+			} else {
+				*buf++ = byte;
+				bufferspace--;
+			}
+		}
+		writel(UDCCS_BO_RPC, ep->reg_udccs);
+		/* RPC/RSP/RNE could now reflect the other packet buffer */
+
+		/* iso is one request per packet */
+		if (ep->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
+			if (udccs & UDCCS_IO_ROF)
+				req->req.status = -EHOSTUNREACH;
+			/* more like "is_done" */
+			is_short = 1;
+		}
+
+		/* completion */
+		if (is_short || req->req.actual == req->req.length) {
+			done(ep, req, 0);
+			if (list_empty(&ep->queue))
+				pio_irq_disable(ep->bEndpointAddress);
+			return 1;
+		}
+
+		/* finished that packet.  the next one may be waiting... */
+	}
+	return 0;
+}
+
+/*
+ * special ep0 version of the above.  no UBCR0 or double buffering; status
+ * handshaking is magic.  most device protocols don't need control-OUT.
+ * CDC vendor commands (and RNDIS), mass storage CB/CBI, and some other
+ * protocols do use them.
+ */
+static int
+read_ep0_fifo(struct pxa25x_ep *ep, struct pxa25x_request *req)
+{
+	u8 *buf, byte;
+	unsigned bufferspace;
+
+	buf = req->req.buf + req->req.actual;
+	bufferspace = req->req.length - req->req.actual;
+
+	while (readl(&ep->dev->regs->udccs[0]) & UDCCS0_RNE) {
+		byte = (u8)readb(&ep->dev->regs->uddr0);
+
+		if (unlikely(bufferspace == 0)) {
+			/*
+			 * this happens when the driver's buffer
+			 * is smaller than what the host sent.
+			 * discard the extra data.
+			 */
+			if (req->req.status != -EOVERFLOW)
+				printf("%s overflow\n", ep->ep.name);
+			req->req.status = -EOVERFLOW;
+		} else {
+			*buf++ = byte;
+			req->req.actual++;
+			bufferspace--;
+		}
+	}
+
+	writel(UDCCS0_OPR | UDCCS0_IPR, &ep->dev->regs->udccs[0]);
+
+	/* completion */
+	if (req->req.actual >= req->req.length)
+		return 1;
+
+	/* finished that packet.  the next one may be waiting... */
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int
+pxa25x_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
+{
+	struct pxa25x_request *req;
+	struct pxa25x_ep *ep;
+	struct pxa25x_udc *dev;
+	unsigned long flags;
+
+	req = container_of(_req, struct pxa25x_request, req);
+	if (unlikely(!_req || !_req->complete || !_req->buf
+			|| !list_empty(&req->queue))) {
+		printf("%s, bad params\n", __func__);
+		return -EINVAL;
+	}
+
+	ep = container_of(_ep, struct pxa25x_ep, ep);
+	if (unlikely(!_ep || (!ep->desc && ep->ep.name != ep0name))) {
+		printf("%s, bad ep\n", __func__);
+		return -EINVAL;
+	}
+
+	dev = ep->dev;
+	if (unlikely(!dev->driver
+			|| dev->gadget.speed == USB_SPEED_UNKNOWN)) {
+		printf("%s, bogus device state\n", __func__);
+		return -ESHUTDOWN;
+	}
+
+	/*
+	 * iso is always one packet per request, that's the only way
+	 * we can report per-packet status.  that also helps with dma.
+	 */
+	if (unlikely(ep->bmAttributes == USB_ENDPOINT_XFER_ISOC
+			&& req->req.length >
+			le16_to_cpu(ep->desc->wMaxPacketSize)))
+		return -EMSGSIZE;
+
+	debug_cond(NOISY, "%s queue req %p, len %d buf %p\n",
+		_ep->name, _req, _req->length, _req->buf);
+
+	local_irq_save(flags);
+
+	_req->status = -EINPROGRESS;
+	_req->actual = 0;
+
+	/* kickstart this i/o queue? */
+	if (list_empty(&ep->queue) && !ep->stopped) {
+		if (ep->desc == NULL/* ep0 */) {
+			unsigned length = _req->length;
+
+			switch (dev->ep0state) {
+			case EP0_IN_DATA_PHASE:
+				dev->stats.write.ops++;
+				if (write_ep0_fifo(ep, req))
+					req = NULL;
+				break;
+
+			case EP0_OUT_DATA_PHASE:
+				dev->stats.read.ops++;
+				/* messy ... */
+				if (dev->req_config) {
+					debug("ep0 config ack%s\n",
+						dev->has_cfr ?  "" : " raced");
+					if (dev->has_cfr)
+						writel(UDCCFR_AREN|UDCCFR_ACM
+							|UDCCFR_MB1,
+							&ep->dev->regs->udccfr);
+					done(ep, req, 0);
+					dev->ep0state = EP0_END_XFER;
+					local_irq_restore(flags);
+					return 0;
+				}
+				if (dev->req_pending)
+					ep0start(dev, UDCCS0_IPR, "OUT");
+				if (length == 0 ||
+						((readl(
+						&ep->dev->regs->udccs[0])
+						& UDCCS0_RNE) != 0
+						&& read_ep0_fifo(ep, req))) {
+					ep0_idle(dev);
+					done(ep, req, 0);
+					req = NULL;
+				}
+				break;
+
+			default:
+				printf("ep0 i/o, odd state %d\n",
+					dev->ep0state);
+				local_irq_restore(flags);
+				return -EL2HLT;
+			}
+		/* can the FIFO can satisfy the request immediately? */
+		} else if ((ep->bEndpointAddress & USB_DIR_IN) != 0) {
+			if ((readl(ep->reg_udccs) & UDCCS_BI_TFS) != 0
+					&& write_fifo(ep, req))
+				req = NULL;
+		} else if ((readl(ep->reg_udccs) & UDCCS_BO_RFS) != 0
+				&& read_fifo(ep, req)) {
+			req = NULL;
+		}
+
+		if (likely(req && ep->desc))
+			pio_irq_enable(ep->bEndpointAddress);
+	}
+
+	/* pio or dma irq handler advances the queue. */
+	if (likely(req != NULL))
+		list_add_tail(&req->queue, &ep->queue);
+	local_irq_restore(flags);
+
+	return 0;
+}
+
+
+/*
+ *	nuke - dequeue ALL requests
+ */
+static void nuke(struct pxa25x_ep *ep, int status)
+{
+	struct pxa25x_request *req;
+
+	/* called with irqs blocked */
+	while (!list_empty(&ep->queue)) {
+		req = list_entry(ep->queue.next,
+				struct pxa25x_request,
+				queue);
+		done(ep, req, status);
+	}
+	if (ep->desc)
+		pio_irq_disable(ep->bEndpointAddress);
+}
+
+
+/* dequeue JUST ONE request */
+static int pxa25x_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
+{
+	struct pxa25x_ep *ep;
+	struct pxa25x_request *req;
+	unsigned long flags;
+
+	ep = container_of(_ep, struct pxa25x_ep, ep);
+	if (!_ep || ep->ep.name == ep0name)
+		return -EINVAL;
+
+	local_irq_save(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) {
+		local_irq_restore(flags);
+		return -EINVAL;
+	}
+
+	done(ep, req, -ECONNRESET);
+
+	local_irq_restore(flags);
+	return 0;
+}
+
+/*-------------------------------------------------------------------------*/
+
+static int pxa25x_ep_set_halt(struct usb_ep *_ep, int value)
+{
+	struct pxa25x_ep *ep;
+	unsigned long flags;
+
+	ep = container_of(_ep, struct pxa25x_ep, ep);
+	if (unlikely(!_ep
+			|| (!ep->desc && ep->ep.name != ep0name))
+			|| ep->bmAttributes == USB_ENDPOINT_XFER_ISOC) {
+		printf("%s, bad ep\n", __func__);
+		return -EINVAL;
+	}
+	if (value == 0) {
+		/*
+		 * this path (reset toggle+halt) is needed to implement
+		 * SET_INTERFACE on normal hardware.  but it can't be
+		 * done from software on the PXA UDC, and the hardware
+		 * forgets to do it as part of SET_INTERFACE automagic.
+		 */
+		printf("only host can clear %s halt\n", _ep->name);
+		return -EROFS;
+	}
+
+	local_irq_save(flags);
+
+	if ((ep->bEndpointAddress & USB_DIR_IN) != 0
+			&& ((readl(ep->reg_udccs) & UDCCS_BI_TFS) == 0
+			   || !list_empty(&ep->queue))) {
+		local_irq_restore(flags);
+		return -EAGAIN;
+	}
+
+	/* FST bit is the same for control, bulk in, bulk out, interrupt in */
+	writel(UDCCS_BI_FST|UDCCS_BI_FTF, ep->reg_udccs);
+
+	/* ep0 needs special care */
+	if (!ep->desc) {
+		start_watchdog(ep->dev);
+		ep->dev->req_pending = 0;
+		ep->dev->ep0state = EP0_STALL;
+
+	/* and bulk/intr endpoints like dropping stalls too */
+	} else {
+		unsigned i;
+		for (i = 0; i < 1000; i += 20) {
+			if (readl(ep->reg_udccs) & UDCCS_BI_SST)
+				break;
+			udelay(20);
+		}
+	}
+	local_irq_restore(flags);
+
+	debug("%s halt\n", _ep->name);
+	return 0;
+}
+
+static int pxa25x_ep_fifo_status(struct usb_ep *_ep)
+{
+	struct pxa25x_ep        *ep;
+
+	ep = container_of(_ep, struct pxa25x_ep, ep);
+	if (!_ep) {
+		printf("%s, bad ep\n", __func__);
+		return -ENODEV;
+	}
+	/* pxa can't report unclaimed bytes from IN fifos */
+	if ((ep->bEndpointAddress & USB_DIR_IN) != 0)
+		return -EOPNOTSUPP;
+	if (ep->dev->gadget.speed == USB_SPEED_UNKNOWN
+			|| (readl(ep->reg_udccs) & UDCCS_BO_RFS) == 0)
+		return 0;
+	else
+		return (readl(ep->reg_ubcr) & 0xfff) + 1;
+}
+
+static void pxa25x_ep_fifo_flush(struct usb_ep *_ep)
+{
+	struct pxa25x_ep        *ep;
+
+	ep = container_of(_ep, struct pxa25x_ep, ep);
+	if (!_ep || ep->ep.name == ep0name || !list_empty(&ep->queue)) {
+		printf("%s, bad ep\n", __func__);
+		return;
+	}
+
+	/* toggle and halt bits stay unchanged */
+
+	/* for OUT, just read and discard the FIFO contents. */
+	if ((ep->bEndpointAddress & USB_DIR_IN) == 0) {
+		while (((readl(ep->reg_udccs)) & UDCCS_BO_RNE) != 0)
+			(void)readb(ep->reg_uddr);
+		return;
+	}
+
+	/* most IN status is the same, but ISO can't stall */
+	writel(UDCCS_BI_TPC|UDCCS_BI_FTF|UDCCS_BI_TUR
+		| (ep->bmAttributes == USB_ENDPOINT_XFER_ISOC
+			? 0 : UDCCS_BI_SST), ep->reg_udccs);
+}
+
+
+static struct usb_ep_ops pxa25x_ep_ops = {
+	.enable		= pxa25x_ep_enable,
+	.disable	= pxa25x_ep_disable,
+
+	.alloc_request	= pxa25x_ep_alloc_request,
+	.free_request	= pxa25x_ep_free_request,
+
+	.queue		= pxa25x_ep_queue,
+	.dequeue	= pxa25x_ep_dequeue,
+
+	.set_halt	= pxa25x_ep_set_halt,
+	.fifo_status	= pxa25x_ep_fifo_status,
+	.fifo_flush	= pxa25x_ep_fifo_flush,
+};
+
+
+/* ---------------------------------------------------------------------------
+ *	device-scoped parts of the api to the usb controller hardware
+ * ---------------------------------------------------------------------------
+ */
+
+static int pxa25x_udc_get_frame(struct usb_gadget *_gadget)
+{
+	return ((readl(&the_controller->regs->ufnrh) & 0x07) << 8) |
+		(readl(&the_controller->regs->ufnrl) & 0xff);
+}
+
+static int pxa25x_udc_wakeup(struct usb_gadget *_gadget)
+{
+	/* host may not have enabled remote wakeup */
+	if ((readl(&the_controller->regs->udccs[0]) & UDCCS0_DRWF) == 0)
+		return -EHOSTUNREACH;
+	udc_set_mask_UDCCR(UDCCR_RSM);
+	return 0;
+}
+
+static void stop_activity(struct pxa25x_udc *, struct usb_gadget_driver *);
+static void udc_enable(struct pxa25x_udc *);
+static void udc_disable(struct pxa25x_udc *);
+
+/*
+ * We disable the UDC -- and its 48 MHz clock -- whenever it's not
+ * in active use.
+ */
+static int pullup(struct pxa25x_udc *udc)
+{
+	if (udc->pullup)
+		pullup_on();
+	else
+		pullup_off();
+
+
+	int is_active = udc->pullup;
+	if (is_active) {
+		if (!udc->active) {
+			udc->active = 1;
+			udc_enable(udc);
+		}
+	} else {
+		if (udc->active) {
+			if (udc->gadget.speed != USB_SPEED_UNKNOWN)
+				stop_activity(udc, udc->driver);
+			udc_disable(udc);
+			udc->active = 0;
+		}
+
+	}
+	return 0;
+}
+
+/* VBUS reporting logically comes from a transceiver */
+static int pxa25x_udc_vbus_session(struct usb_gadget *_gadget, int is_active)
+{
+	struct pxa25x_udc *udc;
+
+	udc = container_of(_gadget, struct pxa25x_udc, gadget);
+	printf("vbus %s\n", is_active ? "supplied" : "inactive");
+	pullup(udc);
+	return 0;
+}
+
+/* drivers may have software control over D+ pullup */
+static int pxa25x_udc_pullup(struct usb_gadget *_gadget, int is_active)
+{
+	struct pxa25x_udc	*udc;
+
+	udc = container_of(_gadget, struct pxa25x_udc, gadget);
+
+	/* not all boards support pullup control */
+	if (!udc->mach->udc_command)
+		return -EOPNOTSUPP;
+
+	udc->pullup = (is_active != 0);
+	pullup(udc);
+	return 0;
+}
+
+/*
+ * boards may consume current from VBUS, up to 100-500mA based on config.
+ * the 500uA suspend ceiling means that exclusively vbus-powered PXA designs
+ * violate USB specs.
+ */
+static int pxa25x_udc_vbus_draw(struct usb_gadget *_gadget, unsigned mA)
+{
+	return -EOPNOTSUPP;
+}
+
+static const struct usb_gadget_ops pxa25x_udc_ops = {
+	.get_frame	= pxa25x_udc_get_frame,
+	.wakeup		= pxa25x_udc_wakeup,
+	.vbus_session	= pxa25x_udc_vbus_session,
+	.pullup		= pxa25x_udc_pullup,
+	.vbus_draw	= pxa25x_udc_vbus_draw,
+};
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ *	udc_disable - disable USB device controller
+ */
+static void udc_disable(struct pxa25x_udc *dev)
+{
+	/* block all irqs */
+	udc_set_mask_UDCCR(UDCCR_SRM|UDCCR_REM);
+	writel(0xff, &dev->regs->uicr0);
+	writel(0xff, &dev->regs->uicr1);
+	writel(UFNRH_SIM, &dev->regs->ufnrh);
+
+	/* if hardware supports it, disconnect from usb */
+	pullup_off();
+
+	udc_clear_mask_UDCCR(UDCCR_UDE);
+
+	ep0_idle(dev);
+	dev->gadget.speed = USB_SPEED_UNKNOWN;
+}
+
+/*
+ *	udc_reinit - initialize software state
+ */
+static void udc_reinit(struct pxa25x_udc *dev)
+{
+	u32 i;
+
+	/* device/ep0 records init */
+	INIT_LIST_HEAD(&dev->gadget.ep_list);
+	INIT_LIST_HEAD(&dev->gadget.ep0->ep_list);
+	dev->ep0state = EP0_IDLE;
+
+	/* basic endpoint records init */
+	for (i = 0; i < PXA_UDC_NUM_ENDPOINTS; i++) {
+		struct pxa25x_ep *ep = &dev->ep[i];
+
+		if (i != 0)
+			list_add_tail(&ep->ep.ep_list, &dev->gadget.ep_list);
+
+		ep->desc = NULL;
+		ep->stopped = 0;
+		INIT_LIST_HEAD(&ep->queue);
+		ep->pio_irqs = 0;
+	}
+
+	/* the rest was statically initialized, and is read-only */
+}
+
+/*
+ * until it's enabled, this UDC should be completely invisible
+ * to any USB host.
+ */
+static void udc_enable(struct pxa25x_udc *dev)
+{
+	debug("udc: enabling udc\n");
+
+	udc_clear_mask_UDCCR(UDCCR_UDE);
+
+	/*
+	 * Try to clear these bits before we enable the udc.
+	 * Do not touch reset ack bit, we would take care of it in
+	 * interrupt handle routine
+	 */
+	udc_ack_int_UDCCR(UDCCR_SUSIR|UDCCR_RESIR);
+
+	ep0_idle(dev);
+	dev->gadget.speed = USB_SPEED_UNKNOWN;
+	dev->stats.irqs = 0;
+
+	/*
+	 * sequence taken from chapter 12.5.10, PXA250 AppProcDevManual:
+	 * - enable UDC
+	 * - if RESET is already in progress, ack interrupt
+	 * - unmask reset interrupt
+	 */
+	udc_set_mask_UDCCR(UDCCR_UDE);
+	if (!(readl(&dev->regs->udccr) & UDCCR_UDA))
+		udc_ack_int_UDCCR(UDCCR_RSTIR);
+
+	if (dev->has_cfr /* UDC_RES2 is defined */) {
+		/*
+		 * pxa255 (a0+) can avoid a set_config race that could
+		 * prevent gadget drivers from configuring correctly
+		 */
+		writel(UDCCFR_ACM | UDCCFR_MB1, &dev->regs->udccfr);
+	}
+
+	/* enable suspend/resume and reset irqs */
+	udc_clear_mask_UDCCR(UDCCR_SRM | UDCCR_REM);
+
+	/* enable ep0 irqs */
+	clrbits_le32(&dev->regs->uicr0, UICR0_IM0);
+
+	/* if hardware supports it, pullup D+ and wait for reset */
+	pullup_on();
+}
+
+static inline void clear_ep_state(struct pxa25x_udc *dev)
+{
+	unsigned i;
+
+	/*
+	 * hardware SET_{CONFIGURATION,INTERFACE} automagic resets endpoint
+	 * fifos, and pending transactions mustn't be continued in any case.
+	 */
+	for (i = 1; i < PXA_UDC_NUM_ENDPOINTS; i++)
+		nuke(&dev->ep[i], -ECONNABORTED);
+}
+
+static void handle_ep0(struct pxa25x_udc *dev)
+{
+	u32 udccs0 = readl(&dev->regs->udccs[0]);
+	struct pxa25x_ep *ep = &dev->ep[0];
+	struct pxa25x_request *req;
+	union {
+		struct usb_ctrlrequest	r;
+		u8			raw[8];
+		u32			word[2];
+	} u;
+
+	if (list_empty(&ep->queue))
+		req = NULL;
+	else
+		req = list_entry(ep->queue.next, struct pxa25x_request, queue);
+
+	/* clear stall status */
+	if (udccs0 & UDCCS0_SST) {
+		nuke(ep, -EPIPE);
+		writel(UDCCS0_SST, &dev->regs->udccs[0]);
+		stop_watchdog(dev);
+		ep0_idle(dev);
+	}
+
+	/* previous request unfinished?  non-error iff back-to-back ... */
+	if ((udccs0 & UDCCS0_SA) != 0 && dev->ep0state != EP0_IDLE) {
+		nuke(ep, 0);
+		stop_watchdog(dev);
+		ep0_idle(dev);
+	}
+
+	switch (dev->ep0state) {
+	case EP0_IDLE:
+		/* late-breaking status? */
+		udccs0 = readl(&dev->regs->udccs[0]);
+
+		/* start control request? */
+		if (likely((udccs0 & (UDCCS0_OPR|UDCCS0_SA|UDCCS0_RNE))
+				== (UDCCS0_OPR|UDCCS0_SA|UDCCS0_RNE))) {
+			int i;
+
+			nuke(ep, -EPROTO);
+
+			/* read SETUP packet */
+			for (i = 0; i < 8; i++) {
+				if (unlikely(!(readl(&dev->regs->udccs[0]) &
+						UDCCS0_RNE))) {
+bad_setup:
+					debug("SETUP %d!\n", i);
+					goto stall;
+				}
+				u.raw[i] = (u8)readb(&dev->regs->uddr0);
+			}
+			if (unlikely((readl(&dev->regs->udccs[0]) &
+					UDCCS0_RNE) != 0))
+				goto bad_setup;
+
+got_setup:
+			debug("SETUP %02x.%02x v%04x i%04x l%04x\n",
+				u.r.bRequestType, u.r.bRequest,
+				le16_to_cpu(u.r.wValue),
+				le16_to_cpu(u.r.wIndex),
+				le16_to_cpu(u.r.wLength));
+
+			/* cope with automagic for some standard requests. */
+			dev->req_std = (u.r.bRequestType & USB_TYPE_MASK)
+						== USB_TYPE_STANDARD;
+			dev->req_config = 0;
+			dev->req_pending = 1;
+			switch (u.r.bRequest) {
+			/* hardware restricts gadget drivers here! */
+			case USB_REQ_SET_CONFIGURATION:
+				debug("GOT SET_CONFIGURATION\n");
+				if (u.r.bRequestType == USB_RECIP_DEVICE) {
+					/*
+					 * reflect hardware's automagic
+					 * up to the gadget driver.
+					 */
+config_change:
+					dev->req_config = 1;
+					clear_ep_state(dev);
+					/*
+					 * if !has_cfr, there's no synch
+					 * else use AREN (later) not SA|OPR
+					 * USIR0_IR0 acts edge sensitive
+					 */
+				}
+				break;
+			/* ... and here, even more ... */
+			case USB_REQ_SET_INTERFACE:
+				if (u.r.bRequestType == USB_RECIP_INTERFACE) {
+					/*
+					 * udc hardware is broken by design:
+					 *  - altsetting may only be zero;
+					 *  - hw resets all interfaces' eps;
+					 *  - ep reset doesn't include halt(?).
+					 */
+					printf("broken set_interface (%d/%d)\n",
+						le16_to_cpu(u.r.wIndex),
+						le16_to_cpu(u.r.wValue));
+					goto config_change;
+				}
+				break;
+			/* hardware was supposed to hide this */
+			case USB_REQ_SET_ADDRESS:
+				debug("GOT SET ADDRESS\n");
+				if (u.r.bRequestType == USB_RECIP_DEVICE) {
+					ep0start(dev, 0, "address");
+					return;
+				}
+				break;
+			}
+
+			if (u.r.bRequestType & USB_DIR_IN)
+				dev->ep0state = EP0_IN_DATA_PHASE;
+			else
+				dev->ep0state = EP0_OUT_DATA_PHASE;
+
+			i = dev->driver->setup(&dev->gadget, &u.r);
+			if (i < 0) {
+				/* hardware automagic preventing STALL... */
+				if (dev->req_config) {
+					/*
+					 * hardware sometimes neglects to tell
+					 * tell us about config change events,
+					 * so later ones may fail...
+					 */
+					printf("config change %02x fail %d?\n",
+						u.r.bRequest, i);
+					return;
+					/*
+					 * TODO experiment:  if has_cfr,
+					 * hardware didn't ACK; maybe we
+					 * could actually STALL!
+					 */
+				}
+				if (0) {
+stall:
+					/* uninitialized when goto stall */
+					i = 0;
+				}
+				debug("protocol STALL, "
+					"%02x err %d\n",
+					readl(&dev->regs->udccs[0]), i);
+
+				/*
+				 * the watchdog timer helps deal with cases
+				 * where udc seems to clear FST wrongly, and
+				 * then NAKs instead of STALLing.
+				 */
+				ep0start(dev, UDCCS0_FST|UDCCS0_FTF, "stall");
+				start_watchdog(dev);
+				dev->ep0state = EP0_STALL;
+
+			/* deferred i/o == no response yet */
+			} else if (dev->req_pending) {
+				if (likely(dev->ep0state == EP0_IN_DATA_PHASE
+						|| dev->req_std || u.r.wLength))
+					ep0start(dev, 0, "defer");
+				else
+					ep0start(dev, UDCCS0_IPR, "defer/IPR");
+			}
+
+			/* expect at least one data or status stage irq */
+			return;
+
+		} else if (likely((udccs0 & (UDCCS0_OPR|UDCCS0_SA))
+				== (UDCCS0_OPR|UDCCS0_SA))) {
+			unsigned i;
+
+			/*
+			 * pxa210/250 erratum 131 for B0/B1 says RNE lies.
+			 * still observed on a pxa255 a0.
+			 */
+			debug("e131\n");
+			nuke(ep, -EPROTO);
+
+			/* read SETUP data, but don't trust it too much */
+			for (i = 0; i < 8; i++)
+				u.raw[i] = (u8)readb(&dev->regs->uddr0);
+			if ((u.r.bRequestType & USB_RECIP_MASK)
+					> USB_RECIP_OTHER)
+				goto stall;
+			if (u.word[0] == 0 && u.word[1] == 0)
+				goto stall;
+			goto got_setup;
+		} else {
+			/*
+			 * some random early IRQ:
+			 * - we acked FST
+			 * - IPR cleared
+			 * - OPR got set, without SA (likely status stage)
+			 */
+			debug("random IRQ %X %X\n", udccs0,
+				readl(&dev->regs->udccs[0]));
+			writel(udccs0 & (UDCCS0_SA|UDCCS0_OPR),
+				&dev->regs->udccs[0]);
+		}
+		break;
+	case EP0_IN_DATA_PHASE:			/* GET_DESCRIPTOR etc */
+		if (udccs0 & UDCCS0_OPR) {
+			debug("ep0in premature status\n");
+			if (req)
+				done(ep, req, 0);
+			ep0_idle(dev);
+		} else /* irq was IPR clearing */ {
+			if (req) {
+				debug("next ep0 in packet\n");
+				/* this IN packet might finish the request */
+				(void) write_ep0_fifo(ep, req);
+			} /* else IN token before response was written */
+		}
+		break;
+	case EP0_OUT_DATA_PHASE:		/* SET_DESCRIPTOR etc */
+		if (udccs0 & UDCCS0_OPR) {
+			if (req) {
+				/* this OUT packet might finish the request */
+				if (read_ep0_fifo(ep, req))
+					done(ep, req, 0);
+				/* else more OUT packets expected */
+			} /* else OUT token before read was issued */
+		} else /* irq was IPR clearing */ {
+			debug("ep0out premature status\n");
+			if (req)
+				done(ep, req, 0);
+			ep0_idle(dev);
+		}
+		break;
+	case EP0_END_XFER:
+		if (req)
+			done(ep, req, 0);
+		/*
+		 * ack control-IN status (maybe in-zlp was skipped)
+		 * also appears after some config change events.
+		 */
+		if (udccs0 & UDCCS0_OPR)
+			writel(UDCCS0_OPR, &dev->regs->udccs[0]);
+		ep0_idle(dev);
+		break;
+	case EP0_STALL:
+		writel(UDCCS0_FST, &dev->regs->udccs[0]);
+		break;
+	}
+
+	writel(USIR0_IR0, &dev->regs->usir0);
+}
+
+static void handle_ep(struct pxa25x_ep *ep)
+{
+	struct pxa25x_request	*req;
+	int			is_in = ep->bEndpointAddress & USB_DIR_IN;
+	int			completed;
+	u32			udccs, tmp;
+
+	do {
+		completed = 0;
+		if (likely(!list_empty(&ep->queue)))
+			req = list_entry(ep->queue.next,
+					struct pxa25x_request, queue);
+		else
+			req = NULL;
+
+		/* TODO check FST handling */
+
+		udccs = readl(ep->reg_udccs);
+		if (unlikely(is_in)) {	/* irq from TPC, SST, or (ISO) TUR */
+			tmp = UDCCS_BI_TUR;
+			if (likely(ep->bmAttributes == USB_ENDPOINT_XFER_BULK))
+				tmp |= UDCCS_BI_SST;
+			tmp &= udccs;
+			if (likely(tmp))
+				writel(tmp, ep->reg_udccs);
+			if (req && likely((udccs & UDCCS_BI_TFS) != 0))
+				completed = write_fifo(ep, req);
+
+		} else {	/* irq from RPC (or for ISO, ROF) */
+			if (likely(ep->bmAttributes == USB_ENDPOINT_XFER_BULK))
+				tmp = UDCCS_BO_SST | UDCCS_BO_DME;
+			else
+				tmp = UDCCS_IO_ROF | UDCCS_IO_DME;
+			tmp &= udccs;
+			if (likely(tmp))
+				writel(tmp, ep->reg_udccs);
+
+			/* fifos can hold packets, ready for reading... */
+			if (likely(req))
+				completed = read_fifo(ep, req);
+			else
+				pio_irq_disable(ep->bEndpointAddress);
+		}
+		ep->pio_irqs++;
+	} while (completed);
+}
+
+/*
+ *	pxa25x_udc_irq - interrupt handler
+ *
+ * avoid delays in ep0 processing. the control handshaking isn't always
+ * under software control (pxa250c0 and the pxa255 are better), and delays
+ * could cause usb protocol errors.
+ */
+static struct pxa25x_udc memory;
+static int
+pxa25x_udc_irq(void)
+{
+	struct pxa25x_udc *dev = &memory;
+	int handled;
+
+	test_watchdog(dev);
+
+	dev->stats.irqs++;
+	do {
+		u32 udccr = readl(&dev->regs->udccr);
+
+		handled = 0;
+
+		/* SUSpend Interrupt Request */
+		if (unlikely(udccr & UDCCR_SUSIR)) {
+			udc_ack_int_UDCCR(UDCCR_SUSIR);
+			handled = 1;
+			debug("USB suspend\n");
+
+			if (dev->gadget.speed != USB_SPEED_UNKNOWN
+					&& dev->driver
+					&& dev->driver->suspend)
+				dev->driver->suspend(&dev->gadget);
+			ep0_idle(dev);
+		}
+
+		/* RESume Interrupt Request */
+		if (unlikely(udccr & UDCCR_RESIR)) {
+			udc_ack_int_UDCCR(UDCCR_RESIR);
+			handled = 1;
+			debug("USB resume\n");
+
+			if (dev->gadget.speed != USB_SPEED_UNKNOWN
+					&& dev->driver
+					&& dev->driver->resume)
+				dev->driver->resume(&dev->gadget);
+		}
+
+		/* ReSeT Interrupt Request - USB reset */
+		if (unlikely(udccr & UDCCR_RSTIR)) {
+			udc_ack_int_UDCCR(UDCCR_RSTIR);
+			handled = 1;
+
+			if ((readl(&dev->regs->udccr) & UDCCR_UDA) == 0) {
+				debug("USB reset start\n");
+
+				/*
+				 * reset driver and endpoints,
+				 * in case that's not yet done
+				 */
+				stop_activity(dev, dev->driver);
+
+			} else {
+				debug("USB reset end\n");
+				dev->gadget.speed = USB_SPEED_FULL;
+				memset(&dev->stats, 0, sizeof dev->stats);
+				/* driver and endpoints are still reset */
+			}
+
+		} else {
+			u32 uicr0 = readl(&dev->regs->uicr0);
+			u32 uicr1 = readl(&dev->regs->uicr1);
+			u32 usir0 = readl(&dev->regs->usir0);
+			u32 usir1 = readl(&dev->regs->usir1);
+
+			usir0 = usir0 & ~uicr0;
+			usir1 = usir1 & ~uicr1;
+			int i;
+
+			if (unlikely(!usir0 && !usir1))
+				continue;
+
+			debug_cond(NOISY, "irq %02x.%02x\n", usir1, usir0);
+
+			/* control traffic */
+			if (usir0 & USIR0_IR0) {
+				dev->ep[0].pio_irqs++;
+				handle_ep0(dev);
+				handled = 1;
+			}
+
+			/* endpoint data transfers */
+			for (i = 0; i < 8; i++) {
+				u32	tmp = 1 << i;
+
+				if (i && (usir0 & tmp)) {
+					handle_ep(&dev->ep[i]);
+					setbits_le32(&dev->regs->usir0, tmp);
+					handled = 1;
+				}
+#ifndef	CONFIG_USB_PXA25X_SMALL
+				if (usir1 & tmp) {
+					handle_ep(&dev->ep[i+8]);
+					setbits_le32(&dev->regs->usir1, tmp);
+					handled = 1;
+				}
+#endif
+			}
+		}
+
+		/* we could also ask for 1 msec SOF (SIR) interrupts */
+
+	} while (handled);
+	return IRQ_HANDLED;
+}
+
+/*-------------------------------------------------------------------------*/
+
+/*
+ * this uses load-time allocation and initialization (instead of
+ * doing it at run-time) to save code, eliminate fault paths, and
+ * be more obviously correct.
+ */
+static struct pxa25x_udc memory = {
+	.regs = UDC_REGS,
+
+	.gadget = {
+		.ops		= &pxa25x_udc_ops,
+		.ep0		= &memory.ep[0].ep,
+		.name		= driver_name,
+	},
+
+	/* control endpoint */
+	.ep[0] = {
+		.ep = {
+			.name		= ep0name,
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= EP0_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.reg_udccs	= &UDC_REGS->udccs[0],
+		.reg_uddr	= &UDC_REGS->uddr0,
+	},
+
+	/* first group of endpoints */
+	.ep[1] = {
+		.ep = {
+			.name		= "ep1in-bulk",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= BULK_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= BULK_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 1,
+		.bmAttributes	= USB_ENDPOINT_XFER_BULK,
+		.reg_udccs	= &UDC_REGS->udccs[1],
+		.reg_uddr	= &UDC_REGS->uddr1,
+	},
+	.ep[2] = {
+		.ep = {
+			.name		= "ep2out-bulk",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= BULK_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= BULK_FIFO_SIZE,
+		.bEndpointAddress = 2,
+		.bmAttributes	= USB_ENDPOINT_XFER_BULK,
+		.reg_udccs	= &UDC_REGS->udccs[2],
+		.reg_ubcr	= &UDC_REGS->ubcr2,
+		.reg_uddr	= &UDC_REGS->uddr2,
+	},
+#ifndef CONFIG_USB_PXA25X_SMALL
+	.ep[3] = {
+		.ep = {
+			.name		= "ep3in-iso",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= ISO_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= ISO_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 3,
+		.bmAttributes	= USB_ENDPOINT_XFER_ISOC,
+		.reg_udccs	= &UDC_REGS->udccs[3],
+		.reg_uddr	= &UDC_REGS->uddr3,
+	},
+	.ep[4] = {
+		.ep = {
+			.name		= "ep4out-iso",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= ISO_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= ISO_FIFO_SIZE,
+		.bEndpointAddress = 4,
+		.bmAttributes	= USB_ENDPOINT_XFER_ISOC,
+		.reg_udccs	= &UDC_REGS->udccs[4],
+		.reg_ubcr	= &UDC_REGS->ubcr4,
+		.reg_uddr	= &UDC_REGS->uddr4,
+	},
+	.ep[5] = {
+		.ep = {
+			.name		= "ep5in-int",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= INT_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= INT_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 5,
+		.bmAttributes	= USB_ENDPOINT_XFER_INT,
+		.reg_udccs	= &UDC_REGS->udccs[5],
+		.reg_uddr	= &UDC_REGS->uddr5,
+	},
+
+	/* second group of endpoints */
+	.ep[6] = {
+		.ep = {
+			.name		= "ep6in-bulk",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= BULK_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= BULK_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 6,
+		.bmAttributes	= USB_ENDPOINT_XFER_BULK,
+		.reg_udccs	= &UDC_REGS->udccs[6],
+		.reg_uddr	= &UDC_REGS->uddr6,
+	},
+	.ep[7] = {
+		.ep = {
+			.name		= "ep7out-bulk",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= BULK_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= BULK_FIFO_SIZE,
+		.bEndpointAddress = 7,
+		.bmAttributes	= USB_ENDPOINT_XFER_BULK,
+		.reg_udccs	= &UDC_REGS->udccs[7],
+		.reg_ubcr	= &UDC_REGS->ubcr7,
+		.reg_uddr	= &UDC_REGS->uddr7,
+	},
+	.ep[8] = {
+		.ep = {
+			.name		= "ep8in-iso",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= ISO_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= ISO_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 8,
+		.bmAttributes	= USB_ENDPOINT_XFER_ISOC,
+		.reg_udccs	= &UDC_REGS->udccs[8],
+		.reg_uddr	= &UDC_REGS->uddr8,
+	},
+	.ep[9] = {
+		.ep = {
+			.name		= "ep9out-iso",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= ISO_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= ISO_FIFO_SIZE,
+		.bEndpointAddress = 9,
+		.bmAttributes	= USB_ENDPOINT_XFER_ISOC,
+		.reg_udccs	= &UDC_REGS->udccs[9],
+		.reg_ubcr	= &UDC_REGS->ubcr9,
+		.reg_uddr	= &UDC_REGS->uddr9,
+	},
+	.ep[10] = {
+		.ep = {
+			.name		= "ep10in-int",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= INT_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= INT_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 10,
+		.bmAttributes	= USB_ENDPOINT_XFER_INT,
+		.reg_udccs	= &UDC_REGS->udccs[10],
+		.reg_uddr	= &UDC_REGS->uddr10,
+	},
+
+	/* third group of endpoints */
+	.ep[11] = {
+		.ep = {
+			.name		= "ep11in-bulk",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= BULK_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= BULK_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 11,
+		.bmAttributes	= USB_ENDPOINT_XFER_BULK,
+		.reg_udccs	= &UDC_REGS->udccs[11],
+		.reg_uddr	= &UDC_REGS->uddr11,
+	},
+	.ep[12] = {
+		.ep = {
+			.name		= "ep12out-bulk",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= BULK_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= BULK_FIFO_SIZE,
+		.bEndpointAddress = 12,
+		.bmAttributes	= USB_ENDPOINT_XFER_BULK,
+		.reg_udccs	= &UDC_REGS->udccs[12],
+		.reg_ubcr	= &UDC_REGS->ubcr12,
+		.reg_uddr	= &UDC_REGS->uddr12,
+	},
+	.ep[13] = {
+		.ep = {
+			.name		= "ep13in-iso",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= ISO_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= ISO_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 13,
+		.bmAttributes	= USB_ENDPOINT_XFER_ISOC,
+		.reg_udccs	= &UDC_REGS->udccs[13],
+		.reg_uddr	= &UDC_REGS->uddr13,
+	},
+	.ep[14] = {
+		.ep = {
+			.name		= "ep14out-iso",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= ISO_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= ISO_FIFO_SIZE,
+		.bEndpointAddress = 14,
+		.bmAttributes	= USB_ENDPOINT_XFER_ISOC,
+		.reg_udccs	= &UDC_REGS->udccs[14],
+		.reg_ubcr	= &UDC_REGS->ubcr14,
+		.reg_uddr	= &UDC_REGS->uddr14,
+	},
+	.ep[15] = {
+		.ep = {
+			.name		= "ep15in-int",
+			.ops		= &pxa25x_ep_ops,
+			.maxpacket	= INT_FIFO_SIZE,
+		},
+		.dev		= &memory,
+		.fifo_size	= INT_FIFO_SIZE,
+		.bEndpointAddress = USB_DIR_IN | 15,
+		.bmAttributes	= USB_ENDPOINT_XFER_INT,
+		.reg_udccs	= &UDC_REGS->udccs[15],
+		.reg_uddr	= &UDC_REGS->uddr15,
+	},
+#endif /* !CONFIG_USB_PXA25X_SMALL */
+};
+
+static void udc_command(int cmd)
+{
+	switch (cmd) {
+	case PXA2XX_UDC_CMD_CONNECT:
+		setbits_le32(GPDR(CONFIG_USB_DEV_PULLUP_GPIO),
+			GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO));
+
+		/* enable pullup */
+		writel(GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO),
+			GPCR(CONFIG_USB_DEV_PULLUP_GPIO));
+
+		debug("Connected to USB\n");
+		break;
+
+	case PXA2XX_UDC_CMD_DISCONNECT:
+		/* disable pullup resistor */
+		writel(GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO),
+			GPSR(CONFIG_USB_DEV_PULLUP_GPIO));
+
+		/* setup pin as input, line will float */
+		clrbits_le32(GPDR(CONFIG_USB_DEV_PULLUP_GPIO),
+			GPIO_bit(CONFIG_USB_DEV_PULLUP_GPIO));
+
+		debug("Disconnected from USB\n");
+		break;
+	}
+}
+
+static struct pxa2xx_udc_mach_info mach_info = {
+	.udc_command = udc_command,
+};
+
+/*
+ * 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 pxa25x_udc *dev = &memory;
+	int retval;
+	uint32_t chiprev;
+
+	if (!driver
+			|| driver->speed < USB_SPEED_FULL
+			|| !driver->disconnect
+			|| !driver->setup)
+		return -EINVAL;
+	if (!dev)
+		return -ENODEV;
+	if (dev->driver)
+		return -EBUSY;
+
+	/* Enable clock for usb controller */
+	setbits_le32(CKEN, CKEN11_USB);
+
+	/* first hook up the driver ... */
+	dev->driver = driver;
+	dev->pullup = 1;
+
+	/* trigger chiprev-specific logic */
+	switch ((chiprev = pxa_get_cpu_revision())) {
+	case PXA255_A0:
+		dev->has_cfr = 1;
+		break;
+	case PXA250_A0:
+	case PXA250_A1:
+		/* A0/A1 "not released"; ep 13, 15 unusable */
+		/* fall through */
+	case PXA250_B2: case PXA210_B2:
+	case PXA250_B1: case PXA210_B1:
+	case PXA250_B0: case PXA210_B0:
+		/* OUT-DMA is broken ... */
+		/* fall through */
+	case PXA250_C0: case PXA210_C0:
+		break;
+	default:
+		printf("%s: unrecognized processor: %08x\n",
+			DRIVER_NAME, chiprev);
+		return -ENODEV;
+	}
+
+	the_controller = dev;
+
+	/* prepare watchdog timer */
+	dev->watchdog.running = 0;
+	dev->watchdog.period = 5000 * CONFIG_SYS_HZ / 1000000; /* 5 ms */
+	dev->watchdog.function = udc_watchdog;
+
+	udc_disable(dev);
+	udc_reinit(dev);
+
+	dev->mach = &mach_info;
+
+	dev->gadget.name = "pxa2xx_udc";
+	retval = driver->bind(&dev->gadget);
+	if (retval) {
+		printf("bind to driver %s --> error %d\n",
+				DRIVER_NAME, retval);
+		dev->driver = NULL;
+		return retval;
+	}
+
+	/*
+	 * ... then enable host detection and ep0; and we're ready
+	 * for set_configuration as well as eventual disconnect.
+	 */
+	printf("registered gadget driver '%s'\n", DRIVER_NAME);
+
+	pullup(dev);
+	dump_state(dev);
+	return 0;
+}
+
+static void
+stop_activity(struct pxa25x_udc *dev, struct usb_gadget_driver *driver)
+{
+	int i;
+
+	/* don't disconnect drivers more than once */
+	if (dev->gadget.speed == USB_SPEED_UNKNOWN)
+		driver = NULL;
+	dev->gadget.speed = USB_SPEED_UNKNOWN;
+
+	/* prevent new request submissions, kill any outstanding requests  */
+	for (i = 0; i < PXA_UDC_NUM_ENDPOINTS; i++) {
+		struct pxa25x_ep *ep = &dev->ep[i];
+
+		ep->stopped = 1;
+		nuke(ep, -ESHUTDOWN);
+	}
+	stop_watchdog(dev);
+
+	/* report disconnect; the driver is already quiesced */
+	if (driver)
+		driver->disconnect(&dev->gadget);
+
+	/* re-init driver-visible data structures */
+	udc_reinit(dev);
+}
+
+int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
+{
+	struct pxa25x_udc	*dev = the_controller;
+
+	if (!dev)
+		return -ENODEV;
+	if (!driver || driver != dev->driver || !driver->unbind)
+		return -EINVAL;
+
+	local_irq_disable();
+	dev->pullup = 0;
+	pullup(dev);
+	stop_activity(dev, driver);
+	local_irq_enable();
+
+	driver->unbind(&dev->gadget);
+	dev->driver = NULL;
+
+	printf("unregistered gadget driver '%s'\n", DRIVER_NAME);
+	dump_state(dev);
+
+	the_controller = NULL;
+
+	clrbits_le32(CKEN, CKEN11_USB);
+
+	return 0;
+}
+
+extern void udc_disconnect(void)
+{
+	setbits_le32(CKEN, CKEN11_USB);
+	udc_clear_mask_UDCCR(UDCCR_UDE);
+	udc_command(PXA2XX_UDC_CMD_DISCONNECT);
+	clrbits_le32(CKEN, CKEN11_USB);
+}
+
+/*-------------------------------------------------------------------------*/
+
+extern int
+usb_gadget_handle_interrupts(void)
+{
+	return pxa25x_udc_irq();
+}