Merge commit 'v2.6.27-rc6' into core/rcu

1 files changed, 2170 insertions, 0 deletions

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
new file mode 100644
index 00000000000..8b4be012669
--- /dev/null
+++ b/drivers/usb/musb/musb_host.c
@@ -0,0 +1,2170 @@
+/*
+ * MUSB OTG driver host support
+ *
+ * Copyright 2005 Mentor Graphics Corporation
+ * Copyright (C) 2005-2006 by Texas Instruments
+ * Copyright (C) 2006-2007 Nokia Corporation
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * version 2 as published by the Free Software Foundation.
+ *
+ * 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., 51 Franklin St, Fifth Floor, Boston, MA
+ * 02110-1301 USA
+ *
+ * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
+ * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/list.h>
+
+#include "musb_core.h"
+#include "musb_host.h"
+
+
+/* MUSB HOST status 22-mar-2006
+ *
+ * - There's still lots of partial code duplication for fault paths, so
+ *   they aren't handled as consistently as they need to be.
+ *
+ * - PIO mostly behaved when last tested.
+ *     + including ep0, with all usbtest cases 9, 10
+ *     + usbtest 14 (ep0out) doesn't seem to run at all
+ *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
+ *       configurations, but otherwise double buffering passes basic tests.
+ *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
+ *
+ * - DMA (CPPI) ... partially behaves, not currently recommended
+ *     + about 1/15 the speed of typical EHCI implementations (PCI)
+ *     + RX, all too often reqpkt seems to misbehave after tx
+ *     + TX, no known issues (other than evident silicon issue)
+ *
+ * - DMA (Mentor/OMAP) ...has at least toggle update problems
+ *
+ * - Still no traffic scheduling code to make NAKing for bulk or control
+ *   transfers unable to starve other requests; or to make efficient use
+ *   of hardware with periodic transfers.  (Note that network drivers
+ *   commonly post bulk reads that stay pending for a long time; these
+ *   would make very visible trouble.)
+ *
+ * - Not tested with HNP, but some SRP paths seem to behave.
+ *
+ * NOTE 24-August-2006:
+ *
+ * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
+ *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
+ *   mostly works, except that with "usbnet" it's easy to trigger cases
+ *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
+ *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
+ *   although ARP RX wins.  (That test was done with a full speed link.)
+ */
+
+
+/*
+ * NOTE on endpoint usage:
+ *
+ * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
+ * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
+ *
+ * (Yes, bulk _could_ use more of the endpoints than that, and would even
+ * benefit from it ... one remote device may easily be NAKing while others
+ * need to perform transfers in that same direction.  The same thing could
+ * be done in software though, assuming dma cooperates.)
+ *
+ * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
+ * So far that scheduling is both dumb and optimistic:  the endpoint will be
+ * "claimed" until its software queue is no longer refilled.  No multiplexing
+ * of transfers between endpoints, or anything clever.
+ */
+
+
+static void musb_ep_program(struct musb *musb, u8 epnum,
+			struct urb *urb, unsigned int nOut,
+			u8 *buf, u32 len);
+
+/*
+ * Clear TX fifo. Needed to avoid BABBLE errors.
+ */
+static inline void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
+{
+	void __iomem	*epio = ep->regs;
+	u16		csr;
+	int		retries = 1000;
+
+	csr = musb_readw(epio, MUSB_TXCSR);
+	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
+		DBG(5, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
+		csr |= MUSB_TXCSR_FLUSHFIFO;
+		musb_writew(epio, MUSB_TXCSR, csr);
+		csr = musb_readw(epio, MUSB_TXCSR);
+		if (retries-- < 1) {
+			ERR("Could not flush host TX fifo: csr: %04x\n", csr);
+			return;
+		}
+		mdelay(1);
+	}
+}
+
+/*
+ * Start transmit. Caller is responsible for locking shared resources.
+ * musb must be locked.
+ */
+static inline void musb_h_tx_start(struct musb_hw_ep *ep)
+{
+	u16	txcsr;
+
+	/* NOTE: no locks here; caller should lock and select EP */
+	if (ep->epnum) {
+		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
+		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
+		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
+	} else {
+		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
+		musb_writew(ep->regs, MUSB_CSR0, txcsr);
+	}
+
+}
+
+static inline void cppi_host_txdma_start(struct musb_hw_ep *ep)
+{
+	u16	txcsr;
+
+	/* NOTE: no locks here; caller should lock and select EP */
+	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
+	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
+	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
+}
+
+/*
+ * Start the URB at the front of an endpoint's queue
+ * end must be claimed from the caller.
+ *
+ * Context: controller locked, irqs blocked
+ */
+static void
+musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
+{
+	u16			frame;
+	u32			len;
+	void			*buf;
+	void __iomem		*mbase =  musb->mregs;
+	struct urb		*urb = next_urb(qh);
+	struct musb_hw_ep	*hw_ep = qh->hw_ep;
+	unsigned		pipe = urb->pipe;
+	u8			address = usb_pipedevice(pipe);
+	int			epnum = hw_ep->epnum;
+
+	/* initialize software qh state */
+	qh->offset = 0;
+	qh->segsize = 0;
+
+	/* gather right source of data */
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		/* control transfers always start with SETUP */
+		is_in = 0;
+		hw_ep->out_qh = qh;
+		musb->ep0_stage = MUSB_EP0_START;
+		buf = urb->setup_packet;
+		len = 8;
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		qh->iso_idx = 0;
+		qh->frame = 0;
+		buf = urb->transfer_buffer + urb->iso_frame_desc[0].offset;
+		len = urb->iso_frame_desc[0].length;
+		break;
+	default:		/* bulk, interrupt */
+		buf = urb->transfer_buffer;
+		len = urb->transfer_buffer_length;
+	}
+
+	DBG(4, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
+			qh, urb, address, qh->epnum,
+			is_in ? "in" : "out",
+			({char *s; switch (qh->type) {
+			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
+			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
+			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
+			default:			s = "-intr"; break;
+			}; s; }),
+			epnum, buf, len);
+
+	/* Configure endpoint */
+	if (is_in || hw_ep->is_shared_fifo)
+		hw_ep->in_qh = qh;
+	else
+		hw_ep->out_qh = qh;
+	musb_ep_program(musb, epnum, urb, !is_in, buf, len);
+
+	/* transmit may have more work: start it when it is time */
+	if (is_in)
+		return;
+
+	/* determine if the time is right for a periodic transfer */
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_ISOC:
+	case USB_ENDPOINT_XFER_INT:
+		DBG(3, "check whether there's still time for periodic Tx\n");
+		qh->iso_idx = 0;
+		frame = musb_readw(mbase, MUSB_FRAME);
+		/* FIXME this doesn't implement that scheduling policy ...
+		 * or handle framecounter wrapping
+		 */
+		if ((urb->transfer_flags & URB_ISO_ASAP)
+				|| (frame >= urb->start_frame)) {
+			/* REVISIT the SOF irq handler shouldn't duplicate
+			 * this code; and we don't init urb->start_frame...
+			 */
+			qh->frame = 0;
+			goto start;
+		} else {
+			qh->frame = urb->start_frame;
+			/* enable SOF interrupt so we can count down */
+			DBG(1, "SOF for %d\n", epnum);
+#if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
+			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
+#endif
+		}
+		break;
+	default:
+start:
+		DBG(4, "Start TX%d %s\n", epnum,
+			hw_ep->tx_channel ? "dma" : "pio");
+
+		if (!hw_ep->tx_channel)
+			musb_h_tx_start(hw_ep);
+		else if (is_cppi_enabled() || tusb_dma_omap())
+			cppi_host_txdma_start(hw_ep);
+	}
+}
+
+/* caller owns controller lock, irqs are blocked */
+static void
+__musb_giveback(struct musb *musb, struct urb *urb, int status)
+__releases(musb->lock)
+__acquires(musb->lock)
+{
+	DBG(({ int level; switch (urb->status) {
+				case 0:
+					level = 4;
+					break;
+				/* common/boring faults */
+				case -EREMOTEIO:
+				case -ESHUTDOWN:
+				case -ECONNRESET:
+				case -EPIPE:
+					level = 3;
+					break;
+				default:
+					level = 2;
+					break;
+				}; level; }),
+			"complete %p (%d), dev%d ep%d%s, %d/%d\n",
+			urb, urb->status,
+			usb_pipedevice(urb->pipe),
+			usb_pipeendpoint(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out",
+			urb->actual_length, urb->transfer_buffer_length
+			);
+
+	spin_unlock(&musb->lock);
+	usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
+	spin_lock(&musb->lock);
+}
+
+/* for bulk/interrupt endpoints only */
+static inline void
+musb_save_toggle(struct musb_hw_ep *ep, int is_in, struct urb *urb)
+{
+	struct usb_device	*udev = urb->dev;
+	u16			csr;
+	void __iomem		*epio = ep->regs;
+	struct musb_qh		*qh;
+
+	/* FIXME:  the current Mentor DMA code seems to have
+	 * problems getting toggle correct.
+	 */
+
+	if (is_in || ep->is_shared_fifo)
+		qh = ep->in_qh;
+	else
+		qh = ep->out_qh;
+
+	if (!is_in) {
+		csr = musb_readw(epio, MUSB_TXCSR);
+		usb_settoggle(udev, qh->epnum, 1,
+			(csr & MUSB_TXCSR_H_DATATOGGLE)
+				? 1 : 0);
+	} else {
+		csr = musb_readw(epio, MUSB_RXCSR);
+		usb_settoggle(udev, qh->epnum, 0,
+			(csr & MUSB_RXCSR_H_DATATOGGLE)
+				? 1 : 0);
+	}
+}
+
+/* caller owns controller lock, irqs are blocked */
+static struct musb_qh *
+musb_giveback(struct musb_qh *qh, struct urb *urb, int status)
+{
+	int			is_in;
+	struct musb_hw_ep	*ep = qh->hw_ep;
+	struct musb		*musb = ep->musb;
+	int			ready = qh->is_ready;
+
+	if (ep->is_shared_fifo)
+		is_in = 1;
+	else
+		is_in = usb_pipein(urb->pipe);
+
+	/* save toggle eagerly, for paranoia */
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_BULK:
+	case USB_ENDPOINT_XFER_INT:
+		musb_save_toggle(ep, is_in, urb);
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		if (status == 0 && urb->error_count)
+			status = -EXDEV;
+		break;
+	}
+
+	usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
+
+	qh->is_ready = 0;
+	__musb_giveback(musb, urb, status);
+	qh->is_ready = ready;
+
+	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
+	 * invalidate qh as soon as list_empty(&hep->urb_list)
+	 */
+	if (list_empty(&qh->hep->urb_list)) {
+		struct list_head	*head;
+
+		if (is_in)
+			ep->rx_reinit = 1;
+		else
+			ep->tx_reinit = 1;
+
+		/* clobber old pointers to this qh */
+		if (is_in || ep->is_shared_fifo)
+			ep->in_qh = NULL;
+		else
+			ep->out_qh = NULL;
+		qh->hep->hcpriv = NULL;
+
+		switch (qh->type) {
+
+		case USB_ENDPOINT_XFER_ISOC:
+		case USB_ENDPOINT_XFER_INT:
+			/* this is where periodic bandwidth should be
+			 * de-allocated if it's tracked and allocated;
+			 * and where we'd update the schedule tree...
+			 */
+			musb->periodic[ep->epnum] = NULL;
+			kfree(qh);
+			qh = NULL;
+			break;
+
+		case USB_ENDPOINT_XFER_CONTROL:
+		case USB_ENDPOINT_XFER_BULK:
+			/* fifo policy for these lists, except that NAKing
+			 * should rotate a qh to the end (for fairness).
+			 */
+			head = qh->ring.prev;
+			list_del(&qh->ring);
+			kfree(qh);
+			qh = first_qh(head);
+			break;
+		}
+	}
+	return qh;
+}
+
+/*
+ * Advance this hardware endpoint's queue, completing the specified urb and
+ * advancing to either the next urb queued to that qh, or else invalidating
+ * that qh and advancing to the next qh scheduled after the current one.
+ *
+ * Context: caller owns controller lock, irqs are blocked
+ */
+static void
+musb_advance_schedule(struct musb *musb, struct urb *urb,
+		struct musb_hw_ep *hw_ep, int is_in)
+{
+	struct musb_qh	*qh;
+
+	if (is_in || hw_ep->is_shared_fifo)
+		qh = hw_ep->in_qh;
+	else
+		qh = hw_ep->out_qh;
+
+	if (urb->status == -EINPROGRESS)
+		qh = musb_giveback(qh, urb, 0);
+	else
+		qh = musb_giveback(qh, urb, urb->status);
+
+	if (qh && qh->is_ready && !list_empty(&qh->hep->urb_list)) {
+		DBG(4, "... next ep%d %cX urb %p\n",
+				hw_ep->epnum, is_in ? 'R' : 'T',
+				next_urb(qh));
+		musb_start_urb(musb, is_in, qh);
+	}
+}
+
+static inline u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
+{
+	/* we don't want fifo to fill itself again;
+	 * ignore dma (various models),
+	 * leave toggle alone (may not have been saved yet)
+	 */
+	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
+	csr &= ~(MUSB_RXCSR_H_REQPKT
+		| MUSB_RXCSR_H_AUTOREQ
+		| MUSB_RXCSR_AUTOCLEAR);
+
+	/* write 2x to allow double buffering */
+	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
+	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
+
+	/* flush writebuffer */
+	return musb_readw(hw_ep->regs, MUSB_RXCSR);
+}
+
+/*
+ * PIO RX for a packet (or part of it).
+ */
+static bool
+musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
+{
+	u16			rx_count;
+	u8			*buf;
+	u16			csr;
+	bool			done = false;
+	u32			length;
+	int			do_flush = 0;
+	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
+	void __iomem		*epio = hw_ep->regs;
+	struct musb_qh		*qh = hw_ep->in_qh;
+	int			pipe = urb->pipe;
+	void			*buffer = urb->transfer_buffer;
+
+	/* musb_ep_select(mbase, epnum); */
+	rx_count = musb_readw(epio, MUSB_RXCOUNT);
+	DBG(3, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
+			urb->transfer_buffer, qh->offset,
+			urb->transfer_buffer_length);
+
+	/* unload FIFO */
+	if (usb_pipeisoc(pipe)) {
+		int					status = 0;
+		struct usb_iso_packet_descriptor	*d;
+
+		if (iso_err) {
+			status = -EILSEQ;
+			urb->error_count++;
+		}
+
+		d = urb->iso_frame_desc + qh->iso_idx;
+		buf = buffer + d->offset;
+		length = d->length;
+		if (rx_count > length) {
+			if (status == 0) {
+				status = -EOVERFLOW;
+				urb->error_count++;
+			}
+			DBG(2, "** OVERFLOW %d into %d\n", rx_count, length);
+			do_flush = 1;
+		} else
+			length = rx_count;
+		urb->actual_length += length;
+		d->actual_length = length;
+
+		d->status = status;
+
+		/* see if we are done */
+		done = (++qh->iso_idx >= urb->number_of_packets);
+	} else {
+		/* non-isoch */
+		buf = buffer + qh->offset;
+		length = urb->transfer_buffer_length - qh->offset;
+		if (rx_count > length) {
+			if (urb->status == -EINPROGRESS)
+				urb->status = -EOVERFLOW;
+			DBG(2, "** OVERFLOW %d into %d\n", rx_count, length);
+			do_flush = 1;
+		} else
+			length = rx_count;
+		urb->actual_length += length;
+		qh->offset += length;
+
+		/* see if we are done */
+		done = (urb->actual_length == urb->transfer_buffer_length)
+			|| (rx_count < qh->maxpacket)
+			|| (urb->status != -EINPROGRESS);
+		if (done
+				&& (urb->status == -EINPROGRESS)
+				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
+				&& (urb->actual_length
+					< urb->transfer_buffer_length))
+			urb->status = -EREMOTEIO;
+	}
+
+	musb_read_fifo(hw_ep, length, buf);
+
+	csr = musb_readw(epio, MUSB_RXCSR);
+	csr |= MUSB_RXCSR_H_WZC_BITS;
+	if (unlikely(do_flush))
+		musb_h_flush_rxfifo(hw_ep, csr);
+	else {
+		/* REVISIT this assumes AUTOCLEAR is never set */
+		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
+		if (!done)
+			csr |= MUSB_RXCSR_H_REQPKT;
+		musb_writew(epio, MUSB_RXCSR, csr);
+	}
+
+	return done;
+}
+
+/* we don't always need to reinit a given side of an endpoint...
+ * when we do, use tx/rx reinit routine and then construct a new CSR
+ * to address data toggle, NYET, and DMA or PIO.
+ *
+ * it's possible that driver bugs (especially for DMA) or aborting a
+ * transfer might have left the endpoint busier than it should be.
+ * the busy/not-empty tests are basically paranoia.
+ */
+static void
+musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
+{
+	u16	csr;
+
+	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
+	 * That always uses tx_reinit since ep0 repurposes TX register
+	 * offsets; the initial SETUP packet is also a kind of OUT.
+	 */
+
+	/* if programmed for Tx, put it in RX mode */
+	if (ep->is_shared_fifo) {
+		csr = musb_readw(ep->regs, MUSB_TXCSR);
+		if (csr & MUSB_TXCSR_MODE) {
+			musb_h_tx_flush_fifo(ep);
+			musb_writew(ep->regs, MUSB_TXCSR,
+					MUSB_TXCSR_FRCDATATOG);
+		}
+		/* clear mode (and everything else) to enable Rx */
+		musb_writew(ep->regs, MUSB_TXCSR, 0);
+
+	/* scrub all previous state, clearing toggle */
+	} else {
+		csr = musb_readw(ep->regs, MUSB_RXCSR);
+		if (csr & MUSB_RXCSR_RXPKTRDY)
+			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
+				musb_readw(ep->regs, MUSB_RXCOUNT));
+
+		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
+	}
+
+	/* target addr and (for multipoint) hub addr/port */
+	if (musb->is_multipoint) {
+		musb_writeb(ep->target_regs, MUSB_RXFUNCADDR,
+			qh->addr_reg);
+		musb_writeb(ep->target_regs, MUSB_RXHUBADDR,
+			qh->h_addr_reg);
+		musb_writeb(ep->target_regs, MUSB_RXHUBPORT,
+			qh->h_port_reg);
+	} else
+		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
+
+	/* protocol/endpoint, interval/NAKlimit, i/o size */
+	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
+	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
+	/* NOTE: bulk combining rewrites high bits of maxpacket */
+	musb_writew(ep->regs, MUSB_RXMAXP, qh->maxpacket);
+
+	ep->rx_reinit = 0;
+}
+
+
+/*
+ * Program an HDRC endpoint as per the given URB
+ * Context: irqs blocked, controller lock held
+ */
+static void musb_ep_program(struct musb *musb, u8 epnum,
+			struct urb *urb, unsigned int is_out,
+			u8 *buf, u32 len)
+{
+	struct dma_controller	*dma_controller;
+	struct dma_channel	*dma_channel;
+	u8			dma_ok;
+	void __iomem		*mbase = musb->mregs;
+	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
+	void __iomem		*epio = hw_ep->regs;
+	struct musb_qh		*qh;
+	u16			packet_sz;
+
+	if (!is_out || hw_ep->is_shared_fifo)
+		qh = hw_ep->in_qh;
+	else
+		qh = hw_ep->out_qh;
+
+	packet_sz = qh->maxpacket;
+
+	DBG(3, "%s hw%d urb %p spd%d dev%d ep%d%s "
+				"h_addr%02x h_port%02x bytes %d\n",
+			is_out ? "-->" : "<--",
+			epnum, urb, urb->dev->speed,
+			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
+			qh->h_addr_reg, qh->h_port_reg,
+			len);
+
+	musb_ep_select(mbase, epnum);
+
+	/* candidate for DMA? */
+	dma_controller = musb->dma_controller;
+	if (is_dma_capable() && epnum && dma_controller) {
+		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
+		if (!dma_channel) {
+			dma_channel = dma_controller->channel_alloc(
+					dma_controller, hw_ep, is_out);
+			if (is_out)
+				hw_ep->tx_channel = dma_channel;
+			else
+				hw_ep->rx_channel = dma_channel;
+		}
+	} else
+		dma_channel = NULL;
+
+	/* make sure we clear DMAEnab, autoSet bits from previous run */
+
+	/* OUT/transmit/EP0 or IN/receive? */
+	if (is_out) {
+		u16	csr;
+		u16	int_txe;
+		u16	load_count;
+
+		csr = musb_readw(epio, MUSB_TXCSR);
+
+		/* disable interrupt in case we flush */
+		int_txe = musb_readw(mbase, MUSB_INTRTXE);
+		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
+
+		/* general endpoint setup */
+		if (epnum) {
+			/* ASSERT:  TXCSR_DMAENAB was already cleared */
+
+			/* flush all old state, set default */
+			musb_h_tx_flush_fifo(hw_ep);
+			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
+					| MUSB_TXCSR_DMAMODE
+					| MUSB_TXCSR_FRCDATATOG
+					| MUSB_TXCSR_H_RXSTALL
+					| MUSB_TXCSR_H_ERROR
+					| MUSB_TXCSR_TXPKTRDY
+					);
+			csr |= MUSB_TXCSR_MODE;
+
+			if (usb_gettoggle(urb->dev,
+					qh->epnum, 1))
+				csr |= MUSB_TXCSR_H_WR_DATATOGGLE
+					| MUSB_TXCSR_H_DATATOGGLE;
+			else
+				csr |= MUSB_TXCSR_CLRDATATOG;
+
+			/* twice in case of double packet buffering */
+			musb_writew(epio, MUSB_TXCSR, csr);
+			/* REVISIT may need to clear FLUSHFIFO ... */
+			musb_writew(epio, MUSB_TXCSR, csr);
+			csr = musb_readw(epio, MUSB_TXCSR);
+		} else {
+			/* endpoint 0: just flush */
+			musb_writew(epio, MUSB_CSR0,
+				csr | MUSB_CSR0_FLUSHFIFO);
+			musb_writew(epio, MUSB_CSR0,
+				csr | MUSB_CSR0_FLUSHFIFO);
+		}
+
+		/* target addr and (for multipoint) hub addr/port */
+		if (musb->is_multipoint) {
+			musb_writeb(mbase,
+				MUSB_BUSCTL_OFFSET(epnum, MUSB_TXFUNCADDR),
+				qh->addr_reg);
+			musb_writeb(mbase,
+				MUSB_BUSCTL_OFFSET(epnum, MUSB_TXHUBADDR),
+				qh->h_addr_reg);
+			musb_writeb(mbase,
+				MUSB_BUSCTL_OFFSET(epnum, MUSB_TXHUBPORT),
+				qh->h_port_reg);
+/* FIXME if !epnum, do the same for RX ... */
+		} else
+			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
+
+		/* protocol/endpoint/interval/NAKlimit */
+		if (epnum) {
+			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
+			if (can_bulk_split(musb, qh->type))
+				musb_writew(epio, MUSB_TXMAXP,
+					packet_sz
+					| ((hw_ep->max_packet_sz_tx /
+						packet_sz) - 1) << 11);
+			else
+				musb_writew(epio, MUSB_TXMAXP,
+					packet_sz);
+			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
+		} else {
+			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
+			if (musb->is_multipoint)
+				musb_writeb(epio, MUSB_TYPE0,
+						qh->type_reg);
+		}
+
+		if (can_bulk_split(musb, qh->type))
+			load_count = min((u32) hw_ep->max_packet_sz_tx,
+						len);
+		else
+			load_count = min((u32) packet_sz, len);
+
+#ifdef CONFIG_USB_INVENTRA_DMA
+		if (dma_channel) {
+
+			/* clear previous state */
+			csr = musb_readw(epio, MUSB_TXCSR);
+			csr &= ~(MUSB_TXCSR_AUTOSET
+				| MUSB_TXCSR_DMAMODE
+				| MUSB_TXCSR_DMAENAB);
+			csr |= MUSB_TXCSR_MODE;
+			musb_writew(epio, MUSB_TXCSR,
+				csr | MUSB_TXCSR_MODE);
+
+			qh->segsize = min(len, dma_channel->max_len);
+
+			if (qh->segsize <= packet_sz)
+				dma_channel->desired_mode = 0;
+			else
+				dma_channel->desired_mode = 1;
+
+
+			if (dma_channel->desired_mode == 0) {
+				csr &= ~(MUSB_TXCSR_AUTOSET
+					| MUSB_TXCSR_DMAMODE);
+				csr |= (MUSB_TXCSR_DMAENAB);
+					/* against programming guide */
+			} else
+				csr |= (MUSB_TXCSR_AUTOSET
+					| MUSB_TXCSR_DMAENAB
+					| MUSB_TXCSR_DMAMODE);
+
+			musb_writew(epio, MUSB_TXCSR, csr);
+
+			dma_ok = dma_controller->channel_program(
+					dma_channel, packet_sz,
+					dma_channel->desired_mode,
+					urb->transfer_dma,
+					qh->segsize);
+			if (dma_ok) {
+				load_count = 0;
+			} else {
+				dma_controller->channel_release(dma_channel);
+				if (is_out)
+					hw_ep->tx_channel = NULL;
+				else
+					hw_ep->rx_channel = NULL;
+				dma_channel = NULL;
+			}
+		}
+#endif
+
+		/* candidate for DMA */
+		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
+
+			/* program endpoint CSRs first, then setup DMA.
+			 * assume CPPI setup succeeds.
+			 * defer enabling dma.
+			 */
+			csr = musb_readw(epio, MUSB_TXCSR);
+			csr &= ~(MUSB_TXCSR_AUTOSET
+					| MUSB_TXCSR_DMAMODE
+					| MUSB_TXCSR_DMAENAB);
+			csr |= MUSB_TXCSR_MODE;
+			musb_writew(epio, MUSB_TXCSR,
+				csr | MUSB_TXCSR_MODE);
+
+			dma_channel->actual_len = 0L;
+			qh->segsize = len;
+
+			/* TX uses "rndis" mode automatically, but needs help
+			 * to identify the zero-length-final-packet case.
+			 */
+			dma_ok = dma_controller->channel_program(
+					dma_channel, packet_sz,
+					(urb->transfer_flags
+							& URB_ZERO_PACKET)
+						== URB_ZERO_PACKET,
+					urb->transfer_dma,
+					qh->segsize);
+			if (dma_ok) {
+				load_count = 0;
+			} else {
+				dma_controller->channel_release(dma_channel);
+				hw_ep->tx_channel = NULL;
+				dma_channel = NULL;
+
+				/* REVISIT there's an error path here that
+				 * needs handling:  can't do dma, but
+				 * there's no pio buffer address...
+				 */
+			}
+		}
+
+		if (load_count) {
+			/* ASSERT:  TXCSR_DMAENAB was already cleared */
+
+			/* PIO to load FIFO */
+			qh->segsize = load_count;
+			musb_write_fifo(hw_ep, load_count, buf);
+			csr = musb_readw(epio, MUSB_TXCSR);
+			csr &= ~(MUSB_TXCSR_DMAENAB
+				| MUSB_TXCSR_DMAMODE
+				| MUSB_TXCSR_AUTOSET);
+			/* write CSR */
+			csr |= MUSB_TXCSR_MODE;
+
+			if (epnum)
+				musb_writew(epio, MUSB_TXCSR, csr);
+		}
+
+		/* re-enable interrupt */
+		musb_writew(mbase, MUSB_INTRTXE, int_txe);
+
+	/* IN/receive */
+	} else {
+		u16	csr;
+
+		if (hw_ep->rx_reinit) {
+			musb_rx_reinit(musb, qh, hw_ep);
+
+			/* init new state: toggle and NYET, maybe DMA later */
+			if (usb_gettoggle(urb->dev, qh->epnum, 0))
+				csr = MUSB_RXCSR_H_WR_DATATOGGLE
+					| MUSB_RXCSR_H_DATATOGGLE;
+			else
+				csr = 0;
+			if (qh->type == USB_ENDPOINT_XFER_INT)
+				csr |= MUSB_RXCSR_DISNYET;
+
+		} else {
+			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
+
+			if (csr & (MUSB_RXCSR_RXPKTRDY
+					| MUSB_RXCSR_DMAENAB
+					| MUSB_RXCSR_H_REQPKT))
+				ERR("broken !rx_reinit, ep%d csr %04x\n",
+						hw_ep->epnum, csr);
+
+			/* scrub any stale state, leaving toggle alone */
+			csr &= MUSB_RXCSR_DISNYET;
+		}
+
+		/* kick things off */
+
+		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
+			/* candidate for DMA */
+			if (dma_channel) {
+				dma_channel->actual_len = 0L;
+				qh->segsize = len;
+
+				/* AUTOREQ is in a DMA register */
+				musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
+				csr = musb_readw(hw_ep->regs,
+						MUSB_RXCSR);
+
+				/* unless caller treats short rx transfers as
+				 * errors, we dare not queue multiple transfers.
+				 */
+				dma_ok = dma_controller->channel_program(
+						dma_channel, packet_sz,
+						!(urb->transfer_flags
+							& URB_SHORT_NOT_OK),
+						urb->transfer_dma,
+						qh->segsize);
+				if (!dma_ok) {
+					dma_controller->channel_release(
+							dma_channel);
+					hw_ep->rx_channel = NULL;
+					dma_channel = NULL;
+				} else
+					csr |= MUSB_RXCSR_DMAENAB;
+			}
+		}
+
+		csr |= MUSB_RXCSR_H_REQPKT;
+		DBG(7, "RXCSR%d := %04x\n", epnum, csr);
+		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
+		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
+	}
+}
+
+
+/*
+ * Service the default endpoint (ep0) as host.
+ * Return true until it's time to start the status stage.
+ */
+static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
+{
+	bool			 more = false;
+	u8			*fifo_dest = NULL;
+	u16			fifo_count = 0;
+	struct musb_hw_ep	*hw_ep = musb->control_ep;
+	struct musb_qh		*qh = hw_ep->in_qh;
+	struct usb_ctrlrequest	*request;
+
+	switch (musb->ep0_stage) {
+	case MUSB_EP0_IN:
+		fifo_dest = urb->transfer_buffer + urb->actual_length;
+		fifo_count = min(len, ((u16) (urb->transfer_buffer_length
+					- urb->actual_length)));
+		if (fifo_count < len)
+			urb->status = -EOVERFLOW;
+
+		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
+
+		urb->actual_length += fifo_count;
+		if (len < qh->maxpacket) {
+			/* always terminate on short read; it's
+			 * rarely reported as an error.
+			 */
+		} else if (urb->actual_length <
+				urb->transfer_buffer_length)
+			more = true;
+		break;
+	case MUSB_EP0_START:
+		request = (struct usb_ctrlrequest *) urb->setup_packet;
+
+		if (!request->wLength) {
+			DBG(4, "start no-DATA\n");
+			break;
+		} else if (request->bRequestType & USB_DIR_IN) {
+			DBG(4, "start IN-DATA\n");
+			musb->ep0_stage = MUSB_EP0_IN;
+			more = true;
+			break;
+		} else {
+			DBG(4, "start OUT-DATA\n");
+			musb->ep0_stage = MUSB_EP0_OUT;
+			more = true;
+		}
+		/* FALLTHROUGH */
+	case MUSB_EP0_OUT:
+		fifo_count = min(qh->maxpacket, ((u16)
+				(urb->transfer_buffer_length
+				- urb->actual_length)));
+
+		if (fifo_count) {
+			fifo_dest = (u8 *) (urb->transfer_buffer
+					+ urb->actual_length);
+			DBG(3, "Sending %d bytes to %p\n",
+					fifo_count, fifo_dest);
+			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
+
+			urb->actual_length += fifo_count;
+			more = true;
+		}
+		break;
+	default:
+		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
+		break;
+	}
+
+	return more;
+}
+
+/*
+ * Handle default endpoint interrupt as host. Only called in IRQ time
+ * from the LinuxIsr() interrupt service routine.
+ *
+ * called with controller irqlocked
+ */
+irqreturn_t musb_h_ep0_irq(struct musb *musb)
+{
+	struct urb		*urb;
+	u16			csr, len;
+	int			status = 0;
+	void __iomem		*mbase = musb->mregs;
+	struct musb_hw_ep	*hw_ep = musb->control_ep;
+	void __iomem		*epio = hw_ep->regs;
+	struct musb_qh		*qh = hw_ep->in_qh;
+	bool			complete = false;
+	irqreturn_t		retval = IRQ_NONE;
+
+	/* ep0 only has one queue, "in" */
+	urb = next_urb(qh);
+
+	musb_ep_select(mbase, 0);
+	csr = musb_readw(epio, MUSB_CSR0);
+	len = (csr & MUSB_CSR0_RXPKTRDY)
+			? musb_readb(epio, MUSB_COUNT0)
+			: 0;
+
+	DBG(4, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
+		csr, qh, len, urb, musb->ep0_stage);
+
+	/* if we just did status stage, we are done */
+	if (MUSB_EP0_STATUS == musb->ep0_stage) {
+		retval = IRQ_HANDLED;
+		complete = true;
+	}
+
+	/* prepare status */
+	if (csr & MUSB_CSR0_H_RXSTALL) {
+		DBG(6, "STALLING ENDPOINT\n");
+		status = -EPIPE;
+
+	} else if (csr & MUSB_CSR0_H_ERROR) {
+		DBG(2, "no response, csr0 %04x\n", csr);
+		status = -EPROTO;
+
+	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
+		DBG(2, "control NAK timeout\n");
+
+		/* NOTE:  this code path would be a good place to PAUSE a
+		 * control transfer, if another one is queued, so that
+		 * ep0 is more likely to stay busy.
+		 *
+		 * if (qh->ring.next != &musb->control), then
+		 * we have a candidate... NAKing is *NOT* an error
+		 */
+		musb_writew(epio, MUSB_CSR0, 0);
+		retval = IRQ_HANDLED;
+	}
+
+	if (status) {
+		DBG(6, "aborting\n");
+		retval = IRQ_HANDLED;
+		if (urb)
+			urb->status = status;
+		complete = true;
+
+		/* use the proper sequence to abort the transfer */
+		if (csr & MUSB_CSR0_H_REQPKT) {
+			csr &= ~MUSB_CSR0_H_REQPKT;
+			musb_writew(epio, MUSB_CSR0, csr);
+			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
+			musb_writew(epio, MUSB_CSR0, csr);
+		} else {
+			csr |= MUSB_CSR0_FLUSHFIFO;
+			musb_writew(epio, MUSB_CSR0, csr);
+			musb_writew(epio, MUSB_CSR0, csr);
+			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
+			musb_writew(epio, MUSB_CSR0, csr);
+		}
+
+		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
+
+		/* clear it */
+		musb_writew(epio, MUSB_CSR0, 0);
+	}
+
+	if (unlikely(!urb)) {
+		/* stop endpoint since we have no place for its data, this
+		 * SHOULD NEVER HAPPEN! */
+		ERR("no URB for end 0\n");
+
+		musb_writew(epio, MUSB_CSR0, MUSB_CSR0_FLUSHFIFO);
+		musb_writew(epio, MUSB_CSR0, MUSB_CSR0_FLUSHFIFO);
+		musb_writew(epio, MUSB_CSR0, 0);
+
+		goto done;
+	}
+
+	if (!complete) {
+		/* call common logic and prepare response */
+		if (musb_h_ep0_continue(musb, len, urb)) {
+			/* more packets required */
+			csr = (MUSB_EP0_IN == musb->ep0_stage)
+				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
+		} else {
+			/* data transfer complete; perform status phase */
+			if (usb_pipeout(urb->pipe)
+					|| !urb->transfer_buffer_length)
+				csr = MUSB_CSR0_H_STATUSPKT
+					| MUSB_CSR0_H_REQPKT;
+			else
+				csr = MUSB_CSR0_H_STATUSPKT
+					| MUSB_CSR0_TXPKTRDY;
+
+			/* flag status stage */
+			musb->ep0_stage = MUSB_EP0_STATUS;
+
+			DBG(5, "ep0 STATUS, csr %04x\n", csr);
+
+		}
+		musb_writew(epio, MUSB_CSR0, csr);
+		retval = IRQ_HANDLED;
+	} else
+		musb->ep0_stage = MUSB_EP0_IDLE;
+
+	/* call completion handler if done */
+	if (complete)
+		musb_advance_schedule(musb, urb, hw_ep, 1);
+done:
+	return retval;
+}
+
+
+#ifdef CONFIG_USB_INVENTRA_DMA
+
+/* Host side TX (OUT) using Mentor DMA works as follows:
+	submit_urb ->
+		- if queue was empty, Program Endpoint
+		- ... which starts DMA to fifo in mode 1 or 0
+
+	DMA Isr (transfer complete) -> TxAvail()
+		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
+					only in musb_cleanup_urb)
+		- TxPktRdy has to be set in mode 0 or for
+			short packets in mode 1.
+*/
+
+#endif
+
+/* Service a Tx-Available or dma completion irq for the endpoint */
+void musb_host_tx(struct musb *musb, u8 epnum)
+{
+	int			pipe;
+	bool			done = false;
+	u16			tx_csr;
+	size_t			wLength = 0;
+	u8			*buf = NULL;
+	struct urb		*urb;
+	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
+	void __iomem		*epio = hw_ep->regs;
+	struct musb_qh		*qh = hw_ep->out_qh;
+	u32			status = 0;
+	void __iomem		*mbase = musb->mregs;
+	struct dma_channel	*dma;
+
+	urb = next_urb(qh);
+
+	musb_ep_select(mbase, epnum);
+	tx_csr = musb_readw(epio, MUSB_TXCSR);
+
+	/* with CPPI, DMA sometimes triggers "extra" irqs */
+	if (!urb) {
+		DBG(4, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
+		goto finish;
+	}
+
+	pipe = urb->pipe;
+	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
+	DBG(4, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
+			dma ? ", dma" : "");
+
+	/* check for errors */
+	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
+		/* dma was disabled, fifo flushed */
+		DBG(3, "TX end %d stall\n", epnum);
+
+		/* stall; record URB status */
+		status = -EPIPE;
+
+	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
+		/* (NON-ISO) dma was disabled, fifo flushed */
+		DBG(3, "TX 3strikes on ep=%d\n", epnum);
+
+		status = -ETIMEDOUT;
+
+	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
+		DBG(6, "TX end=%d device not responding\n", epnum);
+
+		/* NOTE:  this code path would be a good place to PAUSE a
+		 * transfer, if there's some other (nonperiodic) tx urb
+		 * that could use this fifo.  (dma complicates it...)
+		 *
+		 * if (bulk && qh->ring.next != &musb->out_bulk), then
+		 * we have a candidate... NAKing is *NOT* an error
+		 */
+		musb_ep_select(mbase, epnum);
+		musb_writew(epio, MUSB_TXCSR,
+				MUSB_TXCSR_H_WZC_BITS
+				| MUSB_TXCSR_TXPKTRDY);
+		goto finish;
+	}
+
+	if (status) {
+		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
+			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
+			(void) musb->dma_controller->channel_abort(dma);
+		}
+
+		/* do the proper sequence to abort the transfer in the
+		 * usb core; the dma engine should already be stopped.
+		 */
+		musb_h_tx_flush_fifo(hw_ep);
+		tx_csr &= ~(MUSB_TXCSR_AUTOSET
+				| MUSB_TXCSR_DMAENAB
+				| MUSB_TXCSR_H_ERROR
+				| MUSB_TXCSR_H_RXSTALL
+				| MUSB_TXCSR_H_NAKTIMEOUT
+				);
+
+		musb_ep_select(mbase, epnum);
+		musb_writew(epio, MUSB_TXCSR, tx_csr);
+		/* REVISIT may need to clear FLUSHFIFO ... */
+		musb_writew(epio, MUSB_TXCSR, tx_csr);
+		musb_writeb(epio, MUSB_TXINTERVAL, 0);
+
+		done = true;
+	}
+
+	/* second cppi case */
+	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
+		DBG(4, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
+		goto finish;
+
+	}
+
+	/* REVISIT this looks wrong... */
+	if (!status || dma || usb_pipeisoc(pipe)) {
+		if (dma)
+			wLength = dma->actual_len;
+		else
+			wLength = qh->segsize;
+		qh->offset += wLength;
+
+		if (usb_pipeisoc(pipe)) {
+			struct usb_iso_packet_descriptor	*d;
+
+			d = urb->iso_frame_desc + qh->iso_idx;
+			d->actual_length = qh->segsize;
+			if (++qh->iso_idx >= urb->number_of_packets) {
+				done = true;
+			} else {
+				d++;
+				buf = urb->transfer_buffer + d->offset;
+				wLength = d->length;
+			}
+		} else if (dma) {
+			done = true;
+		} else {
+			/* see if we need to send more data, or ZLP */
+			if (qh->segsize < qh->maxpacket)
+				done = true;
+			else if (qh->offset == urb->transfer_buffer_length
+					&& !(urb->transfer_flags
+						& URB_ZERO_PACKET))
+				done = true;
+			if (!done) {
+				buf = urb->transfer_buffer
+						+ qh->offset;
+				wLength = urb->transfer_buffer_length
+						- qh->offset;
+			}
+		}
+	}
+
+	/* urb->status != -EINPROGRESS means request has been faulted,
+	 * so we must abort this transfer after cleanup
+	 */
+	if (urb->status != -EINPROGRESS) {
+		done = true;
+		if (status == 0)
+			status = urb->status;
+	}
+
+	if (done) {
+		/* set status */
+		urb->status = status;
+		urb->actual_length = qh->offset;
+		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
+
+	} else if (!(tx_csr & MUSB_TXCSR_DMAENAB)) {
+		/* WARN_ON(!buf); */
+
+		/* REVISIT:  some docs say that when hw_ep->tx_double_buffered,
+		 * (and presumably, fifo is not half-full) we should write TWO
+		 * packets before updating TXCSR ... other docs disagree ...
+		 */
+		/* PIO:  start next packet in this URB */
+		wLength = min(qh->maxpacket, (u16) wLength);
+		musb_write_fifo(hw_ep, wLength, buf);
+		qh->segsize = wLength;
+
+		musb_ep_select(mbase, epnum);
+		musb_writew(epio, MUSB_TXCSR,
+				MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
+	} else
+		DBG(1, "not complete, but dma enabled?\n");
+
+finish:
+	return;
+}
+
+
+#ifdef CONFIG_USB_INVENTRA_DMA
+
+/* Host side RX (IN) using Mentor DMA works as follows:
+	submit_urb ->
+		- if queue was empty, ProgramEndpoint
+		- first IN token is sent out (by setting ReqPkt)
+	LinuxIsr -> RxReady()
+	/\	=> first packet is received
+	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
+	|		-> DMA Isr (transfer complete) -> RxReady()
+	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
+	|		    - if urb not complete, send next IN token (ReqPkt)
+	|			   |		else complete urb.
+	|			   |
+	---------------------------
+ *
+ * Nuances of mode 1:
+ *	For short packets, no ack (+RxPktRdy) is sent automatically
+ *	(even if AutoClear is ON)
+ *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
+ *	automatically => major problem, as collecting the next packet becomes
+ *	difficult. Hence mode 1 is not used.
+ *
+ * REVISIT
+ *	All we care about at this driver level is that
+ *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
+ *       (b) termination conditions are: short RX, or buffer full;
+ *       (c) fault modes include
+ *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
+ *             (and that endpoint's dma queue stops immediately)
+ *           - overflow (full, PLUS more bytes in the terminal packet)
+ *
+ *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
+ *	thus be a great candidate for using mode 1 ... for all but the
+ *	last packet of one URB's transfer.
+ */
+
+#endif
+
+/*
+ * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
+ * and high-bandwidth IN transfer cases.
+ */
+void musb_host_rx(struct musb *musb, u8 epnum)
+{
+	struct urb		*urb;
+	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
+	void __iomem		*epio = hw_ep->regs;
+	struct musb_qh		*qh = hw_ep->in_qh;
+	size_t			xfer_len;
+	void __iomem		*mbase = musb->mregs;
+	int			pipe;
+	u16			rx_csr, val;
+	bool			iso_err = false;
+	bool			done = false;
+	u32			status;
+	struct dma_channel	*dma;
+
+	musb_ep_select(mbase, epnum);
+
+	urb = next_urb(qh);
+	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
+	status = 0;
+	xfer_len = 0;
+
+	rx_csr = musb_readw(epio, MUSB_RXCSR);
+	val = rx_csr;
+
+	if (unlikely(!urb)) {
+		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
+		 * usbtest #11 (unlinks) triggers it regularly, sometimes
+		 * with fifo full.  (Only with DMA??)
+		 */
+		DBG(3, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
+			musb_readw(epio, MUSB_RXCOUNT));
+		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
+		return;
+	}
+
+	pipe = urb->pipe;
+
+	DBG(5, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
+		epnum, rx_csr, urb->actual_length,
+		dma ? dma->actual_len : 0);
+
+	/* check for errors, concurrent stall & unlink is not really
+	 * handled yet! */
+	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
+		DBG(3, "RX end %d STALL\n", epnum);
+
+		/* stall; record URB status */
+		status = -EPIPE;
+
+	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
+		DBG(3, "end %d RX proto error\n", epnum);
+
+		status = -EPROTO;
+		musb_writeb(epio, MUSB_RXINTERVAL, 0);
+
+	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
+
+		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
+			/* NOTE this code path would be a good place to PAUSE a
+			 * transfer, if there's some other (nonperiodic) rx urb
+			 * that could use this fifo.  (dma complicates it...)
+			 *
+			 * if (bulk && qh->ring.next != &musb->in_bulk), then
+			 * we have a candidate... NAKing is *NOT* an error
+			 */
+			DBG(6, "RX end %d NAK timeout\n", epnum);
+			musb_ep_select(mbase, epnum);
+			musb_writew(epio, MUSB_RXCSR,
+					MUSB_RXCSR_H_WZC_BITS
+					| MUSB_RXCSR_H_REQPKT);
+
+			goto finish;
+		} else {
+			DBG(4, "RX end %d ISO data error\n", epnum);
+			/* packet error reported later */
+			iso_err = true;
+		}
+	}
+
+	/* faults abort the transfer */
+	if (status) {
+		/* clean up dma and collect transfer count */
+		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
+			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
+			(void) musb->dma_controller->channel_abort(dma);
+			xfer_len = dma->actual_len;
+		}
+		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
+		musb_writeb(epio, MUSB_RXINTERVAL, 0);
+		done = true;
+		goto finish;
+	}
+
+	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
+		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
+		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
+		goto finish;
+	}
+
+	/* thorough shutdown for now ... given more precise fault handling
+	 * and better queueing support, we might keep a DMA pipeline going
+	 * while processing this irq for earlier completions.
+	 */
+
+	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
+
+#ifndef CONFIG_USB_INVENTRA_DMA
+	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
+		/* REVISIT this happened for a while on some short reads...
+		 * the cleanup still needs investigation... looks bad...
+		 * and also duplicates dma cleanup code above ... plus,
+		 * shouldn't this be the "half full" double buffer case?
+		 */
+		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
+			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
+			(void) musb->dma_controller->channel_abort(dma);
+			xfer_len = dma->actual_len;
+			done = true;
+		}
+
+		DBG(2, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
+				xfer_len, dma ? ", dma" : "");
+		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
+
+		musb_ep_select(mbase, epnum);
+		musb_writew(epio, MUSB_RXCSR,
+				MUSB_RXCSR_H_WZC_BITS | rx_csr);
+	}
+#endif
+	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
+		xfer_len = dma->actual_len;
+
+		val &= ~(MUSB_RXCSR_DMAENAB
+			| MUSB_RXCSR_H_AUTOREQ
+			| MUSB_RXCSR_AUTOCLEAR
+			| MUSB_RXCSR_RXPKTRDY);
+		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
+
+#ifdef CONFIG_USB_INVENTRA_DMA
+		/* done if urb buffer is full or short packet is recd */
+		done = (urb->actual_length + xfer_len >=
+				urb->transfer_buffer_length
+			|| dma->actual_len < qh->maxpacket);
+
+		/* send IN token for next packet, without AUTOREQ */
+		if (!done) {
+			val |= MUSB_RXCSR_H_REQPKT;
+			musb_writew(epio, MUSB_RXCSR,
+				MUSB_RXCSR_H_WZC_BITS | val);
+		}
+
+		DBG(4, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
+			done ? "off" : "reset",
+			musb_readw(epio, MUSB_RXCSR),
+			musb_readw(epio, MUSB_RXCOUNT));
+#else
+		done = true;
+#endif
+	} else if (urb->status == -EINPROGRESS) {
+		/* if no errors, be sure a packet is ready for unloading */
+		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
+			status = -EPROTO;
+			ERR("Rx interrupt with no errors or packet!\n");
+
+			/* FIXME this is another "SHOULD NEVER HAPPEN" */
+
+/* SCRUB (RX) */
+			/* do the proper sequence to abort the transfer */
+			musb_ep_select(mbase, epnum);
+			val &= ~MUSB_RXCSR_H_REQPKT;
+			musb_writew(epio, MUSB_RXCSR, val);
+			goto finish;
+		}
+
+		/* we are expecting IN packets */
+#ifdef CONFIG_USB_INVENTRA_DMA
+		if (dma) {
+			struct dma_controller	*c;
+			u16			rx_count;
+			int			ret;
+
+			rx_count = musb_readw(epio, MUSB_RXCOUNT);
+
+			DBG(2, "RX%d count %d, buffer 0x%x len %d/%d\n",
+					epnum, rx_count,
+					urb->transfer_dma
+						+ urb->actual_length,
+					qh->offset,
+					urb->transfer_buffer_length);
+
+			c = musb->dma_controller;
+
+			dma->desired_mode = 0;
+#ifdef USE_MODE1
+			/* because of the issue below, mode 1 will
+			 * only rarely behave with correct semantics.
+			 */
+			if ((urb->transfer_flags &
+						URB_SHORT_NOT_OK)
+				&& (urb->transfer_buffer_length -
+						urb->actual_length)
+					> qh->maxpacket)
+				dma->desired_mode = 1;
+#endif
+
+/* Disadvantage of using mode 1:
+ *	It's basically usable only for mass storage class; essentially all
+ *	other protocols also terminate transfers on short packets.
+ *
+ * Details:
+ *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
+ *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
+ *	to use the extra IN token to grab the last packet using mode 0, then
+ *	the problem is that you cannot be sure when the device will send the
+ *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
+ *	such that it gets lost when RxCSR is re-set at the end of the mode 1
+ *	transfer, while sometimes it is recd just a little late so that if you
+ *	try to configure for mode 0 soon after the mode 1 transfer is
+ *	completed, you will find rxcount 0. Okay, so you might think why not
+ *	wait for an interrupt when the pkt is recd. Well, you won't get any!
+ */
+
+			val = musb_readw(epio, MUSB_RXCSR);
+			val &= ~MUSB_RXCSR_H_REQPKT;
+
+			if (dma->desired_mode == 0)
+				val &= ~MUSB_RXCSR_H_AUTOREQ;
+			else
+				val |= MUSB_RXCSR_H_AUTOREQ;
+			val |= MUSB_RXCSR_AUTOCLEAR | MUSB_RXCSR_DMAENAB;
+
+			musb_writew(epio, MUSB_RXCSR,
+				MUSB_RXCSR_H_WZC_BITS | val);
+
+			/* REVISIT if when actual_length != 0,
+			 * transfer_buffer_length needs to be
+			 * adjusted first...
+			 */
+			ret = c->channel_program(
+				dma, qh->maxpacket,
+				dma->desired_mode,
+				urb->transfer_dma
+					+ urb->actual_length,
+				(dma->desired_mode == 0)
+					? rx_count
+					: urb->transfer_buffer_length);
+
+			if (!ret) {
+				c->channel_release(dma);
+				hw_ep->rx_channel = NULL;
+				dma = NULL;
+				/* REVISIT reset CSR */
+			}
+		}
+#endif	/* Mentor DMA */
+
+		if (!dma) {
+			done = musb_host_packet_rx(musb, urb,
+					epnum, iso_err);
+			DBG(6, "read %spacket\n", done ? "last " : "");
+		}
+	}
+
+	if (dma && usb_pipeisoc(pipe)) {
+		struct usb_iso_packet_descriptor	*d;
+		int					iso_stat = status;
+
+		d = urb->iso_frame_desc + qh->iso_idx;
+		d->actual_length += xfer_len;
+		if (iso_err) {
+			iso_stat = -EILSEQ;
+			urb->error_count++;
+		}
+		d->status = iso_stat;
+	}
+
+finish:
+	urb->actual_length += xfer_len;
+	qh->offset += xfer_len;
+	if (done) {
+		if (urb->status == -EINPROGRESS)
+			urb->status = status;
+		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
+	}
+}
+
+/* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
+ * the software schedule associates multiple such nodes with a given
+ * host side hardware endpoint + direction; scheduling may activate
+ * that hardware endpoint.
+ */
+static int musb_schedule(
+	struct musb		*musb,
+	struct musb_qh		*qh,
+	int			is_in)
+{
+	int			idle;
+	int			best_diff;
+	int			best_end, epnum;
+	struct musb_hw_ep	*hw_ep = NULL;
+	struct list_head	*head = NULL;
+
+	/* use fixed hardware for control and bulk */
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		head = &musb->control;
+		hw_ep = musb->control_ep;
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		hw_ep = musb->bulk_ep;
+		if (is_in)
+			head = &musb->in_bulk;
+		else
+			head = &musb->out_bulk;
+		break;
+	}
+	if (head) {
+		idle = list_empty(head);
+		list_add_tail(&qh->ring, head);
+		goto success;
+	}
+
+	/* else, periodic transfers get muxed to other endpoints */
+
+	/* FIXME this doesn't consider direction, so it can only
+	 * work for one half of the endpoint hardware, and assumes
+	 * the previous cases handled all non-shared endpoints...
+	 */
+
+	/* we know this qh hasn't been scheduled, so all we need to do
+	 * is choose which hardware endpoint to put it on ...
+	 *
+	 * REVISIT what we really want here is a regular schedule tree
+	 * like e.g. OHCI uses, but for now musb->periodic is just an
+	 * array of the _single_ logical endpoint associated with a
+	 * given physical one (identity mapping logical->physical).
+	 *
+	 * that simplistic approach makes TT scheduling a lot simpler;
+	 * there is none, and thus none of its complexity...
+	 */
+	best_diff = 4096;
+	best_end = -1;
+
+	for (epnum = 1; epnum < musb->nr_endpoints; epnum++) {
+		int	diff;
+
+		if (musb->periodic[epnum])
+			continue;
+		hw_ep = &musb->endpoints[epnum];
+		if (hw_ep == musb->bulk_ep)
+			continue;
+
+		if (is_in)
+			diff = hw_ep->max_packet_sz_rx - qh->maxpacket;
+		else
+			diff = hw_ep->max_packet_sz_tx - qh->maxpacket;
+
+		if (diff > 0 && best_diff > diff) {
+			best_diff = diff;
+			best_end = epnum;
+		}
+	}
+	if (best_end < 0)
+		return -ENOSPC;
+
+	idle = 1;
+	hw_ep = musb->endpoints + best_end;
+	musb->periodic[best_end] = qh;
+	DBG(4, "qh %p periodic slot %d\n", qh, best_end);
+success:
+	qh->hw_ep = hw_ep;
+	qh->hep->hcpriv = qh;
+	if (idle)
+		musb_start_urb(musb, is_in, qh);
+	return 0;
+}
+
+static int musb_urb_enqueue(
+	struct usb_hcd			*hcd,
+	struct urb			*urb,
+	gfp_t				mem_flags)
+{
+	unsigned long			flags;
+	struct musb			*musb = hcd_to_musb(hcd);
+	struct usb_host_endpoint	*hep = urb->ep;
+	struct musb_qh			*qh = hep->hcpriv;
+	struct usb_endpoint_descriptor	*epd = &hep->desc;
+	int				ret;
+	unsigned			type_reg;
+	unsigned			interval;
+
+	/* host role must be active */
+	if (!is_host_active(musb) || !musb->is_active)
+		return -ENODEV;
+
+	spin_lock_irqsave(&musb->lock, flags);
+	ret = usb_hcd_link_urb_to_ep(hcd, urb);
+	spin_unlock_irqrestore(&musb->lock, flags);
+	if (ret)
+		return ret;
+
+	/* DMA mapping was already done, if needed, and this urb is on
+	 * hep->urb_list ... so there's little to do unless hep wasn't
+	 * yet scheduled onto a live qh.
+	 *
+	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
+	 * disabled, testing for empty qh->ring and avoiding qh setup costs
+	 * except for the first urb queued after a config change.
+	 */
+	if (qh) {
+		urb->hcpriv = qh;
+		return 0;
+	}
+
+	/* Allocate and initialize qh, minimizing the work done each time
+	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
+	 *
+	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
+	 * for bugs in other kernel code to break this driver...
+	 */
+	qh = kzalloc(sizeof *qh, mem_flags);
+	if (!qh) {
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
+		return -ENOMEM;
+	}
+
+	qh->hep = hep;
+	qh->dev = urb->dev;
+	INIT_LIST_HEAD(&qh->ring);
+	qh->is_ready = 1;
+
+	qh->maxpacket = le16_to_cpu(epd->wMaxPacketSize);
+
+	/* no high bandwidth support yet */
+	if (qh->maxpacket & ~0x7ff) {
+		ret = -EMSGSIZE;
+		goto done;
+	}
+
+	qh->epnum = epd->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
+	qh->type = epd->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
+
+	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
+	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
+
+	/* precompute rxtype/txtype/type0 register */
+	type_reg = (qh->type << 4) | qh->epnum;
+	switch (urb->dev->speed) {
+	case USB_SPEED_LOW:
+		type_reg |= 0xc0;
+		break;
+	case USB_SPEED_FULL:
+		type_reg |= 0x80;
+		break;
+	default:
+		type_reg |= 0x40;
+	}
+	qh->type_reg = type_reg;
+
+	/* precompute rxinterval/txinterval register */
+	interval = min((u8)16, epd->bInterval);	/* log encoding */
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_INT:
+		/* fullspeed uses linear encoding */
+		if (USB_SPEED_FULL == urb->dev->speed) {
+			interval = epd->bInterval;
+			if (!interval)
+				interval = 1;
+		}
+		/* FALLTHROUGH */
+	case USB_ENDPOINT_XFER_ISOC:
+		/* iso always uses log encoding */
+		break;
+	default:
+		/* REVISIT we actually want to use NAK limits, hinting to the
+		 * transfer scheduling logic to try some other qh, e.g. try
+		 * for 2 msec first:
+		 *
+		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
+		 *
+		 * The downside of disabling this is that transfer scheduling
+		 * gets VERY unfair for nonperiodic transfers; a misbehaving
+		 * peripheral could make that hurt.  Or for reads, one that's
+		 * perfectly normal:  network and other drivers keep reads
+		 * posted at all times, having one pending for a week should
+		 * be perfectly safe.
+		 *
+		 * The upside of disabling it is avoidng transfer scheduling
+		 * code to put this aside for while.
+		 */
+		interval = 0;
+	}
+	qh->intv_reg = interval;
+
+	/* precompute addressing for external hub/tt ports */
+	if (musb->is_multipoint) {
+		struct usb_device	*parent = urb->dev->parent;
+
+		if (parent != hcd->self.root_hub) {
+			qh->h_addr_reg = (u8) parent->devnum;
+
+			/* set up tt info if needed */
+			if (urb->dev->tt) {
+				qh->h_port_reg = (u8) urb->dev->ttport;
+				qh->h_addr_reg |= 0x80;
+			}
+		}
+	}
+
+	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
+	 * until we get real dma queues (with an entry for each urb/buffer),
+	 * we only have work to do in the former case.
+	 */
+	spin_lock_irqsave(&musb->lock, flags);
+	if (hep->hcpriv) {
+		/* some concurrent activity submitted another urb to hep...
+		 * odd, rare, error prone, but legal.
+		 */
+		kfree(qh);
+		ret = 0;
+	} else
+		ret = musb_schedule(musb, qh,
+				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
+
+	if (ret == 0) {
+		urb->hcpriv = qh;
+		/* FIXME set urb->start_frame for iso/intr, it's tested in
+		 * musb_start_urb(), but otherwise only konicawc cares ...
+		 */
+	}
+	spin_unlock_irqrestore(&musb->lock, flags);
+
+done:
+	if (ret != 0) {
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
+		kfree(qh);
+	}
+	return ret;
+}
+
+
+/*
+ * abort a transfer that's at the head of a hardware queue.
+ * called with controller locked, irqs blocked
+ * that hardware queue advances to the next transfer, unless prevented
+ */
+static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh, int is_in)
+{
+	struct musb_hw_ep	*ep = qh->hw_ep;
+	void __iomem		*epio = ep->regs;
+	unsigned		hw_end = ep->epnum;
+	void __iomem		*regs = ep->musb->mregs;
+	u16			csr;
+	int			status = 0;
+
+	musb_ep_select(regs, hw_end);
+
+	if (is_dma_capable()) {
+		struct dma_channel	*dma;
+
+		dma = is_in ? ep->rx_channel : ep->tx_channel;
+		if (dma) {
+			status = ep->musb->dma_controller->channel_abort(dma);
+			DBG(status ? 1 : 3,
+				"abort %cX%d DMA for urb %p --> %d\n",
+				is_in ? 'R' : 'T', ep->epnum,
+				urb, status);
+			urb->actual_length += dma->actual_len;
+		}
+	}
+
+	/* turn off DMA requests, discard state, stop polling ... */
+	if (is_in) {
+		/* giveback saves bulk toggle */
+		csr = musb_h_flush_rxfifo(ep, 0);
+
+		/* REVISIT we still get an irq; should likely clear the
+		 * endpoint's irq status here to avoid bogus irqs.
+		 * clearing that status is platform-specific...
+		 */
+	} else {
+		musb_h_tx_flush_fifo(ep);
+		csr = musb_readw(epio, MUSB_TXCSR);
+		csr &= ~(MUSB_TXCSR_AUTOSET
+			| MUSB_TXCSR_DMAENAB
+			| MUSB_TXCSR_H_RXSTALL
+			| MUSB_TXCSR_H_NAKTIMEOUT
+			| MUSB_TXCSR_H_ERROR
+			| MUSB_TXCSR_TXPKTRDY);
+		musb_writew(epio, MUSB_TXCSR, csr);
+		/* REVISIT may need to clear FLUSHFIFO ... */
+		musb_writew(epio, MUSB_TXCSR, csr);
+		/* flush cpu writebuffer */
+		csr = musb_readw(epio, MUSB_TXCSR);
+	}
+	if (status == 0)
+		musb_advance_schedule(ep->musb, urb, ep, is_in);
+	return status;
+}
+
+static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
+{
+	struct musb		*musb = hcd_to_musb(hcd);
+	struct musb_qh		*qh;
+	struct list_head	*sched;
+	unsigned long		flags;
+	int			ret;
+
+	DBG(4, "urb=%p, dev%d ep%d%s\n", urb,
+			usb_pipedevice(urb->pipe),
+			usb_pipeendpoint(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out");
+
+	spin_lock_irqsave(&musb->lock, flags);
+	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
+	if (ret)
+		goto done;
+
+	qh = urb->hcpriv;
+	if (!qh)
+		goto done;
+
+	/* Any URB not actively programmed into endpoint hardware can be
+	 * immediately given back.  Such an URB must be at the head of its
+	 * endpoint queue, unless someday we get real DMA queues.  And even
+	 * then, it might not be known to the hardware...
+	 *
+	 * Otherwise abort current transfer, pending dma, etc.; urb->status
+	 * has already been updated.  This is a synchronous abort; it'd be
+	 * OK to hold off until after some IRQ, though.
+	 */
+	if (!qh->is_ready || urb->urb_list.prev != &qh->hep->urb_list)
+		ret = -EINPROGRESS;
+	else {
+		switch (qh->type) {
+		case USB_ENDPOINT_XFER_CONTROL:
+			sched = &musb->control;
+			break;
+		case USB_ENDPOINT_XFER_BULK:
+			if (usb_pipein(urb->pipe))
+				sched = &musb->in_bulk;
+			else
+				sched = &musb->out_bulk;
+			break;
+		default:
+			/* REVISIT when we get a schedule tree, periodic
+			 * transfers won't always be at the head of a
+			 * singleton queue...
+			 */
+			sched = NULL;
+			break;
+		}
+	}
+
+	/* NOTE:  qh is invalid unless !list_empty(&hep->urb_list) */
+	if (ret < 0 || (sched && qh != first_qh(sched))) {
+		int	ready = qh->is_ready;
+
+		ret = 0;
+		qh->is_ready = 0;
+		__musb_giveback(musb, urb, 0);
+		qh->is_ready = ready;
+	} else
+		ret = musb_cleanup_urb(urb, qh, urb->pipe & USB_DIR_IN);
+done:
+	spin_unlock_irqrestore(&musb->lock, flags);
+	return ret;
+}
+
+/* disable an endpoint */
+static void
+musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
+{
+	u8			epnum = hep->desc.bEndpointAddress;
+	unsigned long		flags;
+	struct musb		*musb = hcd_to_musb(hcd);
+	u8			is_in = epnum & USB_DIR_IN;
+	struct musb_qh		*qh = hep->hcpriv;
+	struct urb		*urb, *tmp;
+	struct list_head	*sched;
+
+	if (!qh)
+		return;
+
+	spin_lock_irqsave(&musb->lock, flags);
+
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_CONTROL:
+		sched = &musb->control;
+		break;
+	case USB_ENDPOINT_XFER_BULK:
+		if (is_in)
+			sched = &musb->in_bulk;
+		else
+			sched = &musb->out_bulk;
+		break;
+	default:
+		/* REVISIT when we get a schedule tree, periodic transfers
+		 * won't always be at the head of a singleton queue...
+		 */
+		sched = NULL;
+		break;
+	}
+
+	/* NOTE:  qh is invalid unless !list_empty(&hep->urb_list) */
+
+	/* kick first urb off the hardware, if needed */
+	qh->is_ready = 0;
+	if (!sched || qh == first_qh(sched)) {
+		urb = next_urb(qh);
+
+		/* make software (then hardware) stop ASAP */
+		if (!urb->unlinked)
+			urb->status = -ESHUTDOWN;
+
+		/* cleanup */
+		musb_cleanup_urb(urb, qh, urb->pipe & USB_DIR_IN);
+	} else
+		urb = NULL;
+
+	/* then just nuke all the others */
+	list_for_each_entry_safe_from(urb, tmp, &hep->urb_list, urb_list)
+		musb_giveback(qh, urb, -ESHUTDOWN);
+
+	spin_unlock_irqrestore(&musb->lock, flags);
+}
+
+static int musb_h_get_frame_number(struct usb_hcd *hcd)
+{
+	struct musb	*musb = hcd_to_musb(hcd);
+
+	return musb_readw(musb->mregs, MUSB_FRAME);
+}
+
+static int musb_h_start(struct usb_hcd *hcd)
+{
+	struct musb	*musb = hcd_to_musb(hcd);
+
+	/* NOTE: musb_start() is called when the hub driver turns
+	 * on port power, or when (OTG) peripheral starts.
+	 */
+	hcd->state = HC_STATE_RUNNING;
+	musb->port1_status = 0;
+	return 0;
+}
+
+static void musb_h_stop(struct usb_hcd *hcd)
+{
+	musb_stop(hcd_to_musb(hcd));
+	hcd->state = HC_STATE_HALT;
+}
+
+static int musb_bus_suspend(struct usb_hcd *hcd)
+{
+	struct musb	*musb = hcd_to_musb(hcd);
+
+	if (musb->xceiv.state == OTG_STATE_A_SUSPEND)
+		return 0;
+
+	if (is_host_active(musb) && musb->is_active) {
+		WARNING("trying to suspend as %s is_active=%i\n",
+			otg_state_string(musb), musb->is_active);
+		return -EBUSY;
+	} else
+		return 0;
+}
+
+static int musb_bus_resume(struct usb_hcd *hcd)
+{
+	/* resuming child port does the work */
+	return 0;
+}
+
+const struct hc_driver musb_hc_driver = {
+	.description		= "musb-hcd",
+	.product_desc		= "MUSB HDRC host driver",
+	.hcd_priv_size		= sizeof(struct musb),
+	.flags			= HCD_USB2 | HCD_MEMORY,
+
+	/* not using irq handler or reset hooks from usbcore, since
+	 * those must be shared with peripheral code for OTG configs
+	 */
+
+	.start			= musb_h_start,
+	.stop			= musb_h_stop,
+
+	.get_frame_number	= musb_h_get_frame_number,
+
+	.urb_enqueue		= musb_urb_enqueue,
+	.urb_dequeue		= musb_urb_dequeue,
+	.endpoint_disable	= musb_h_disable,
+
+	.hub_status_data	= musb_hub_status_data,
+	.hub_control		= musb_hub_control,
+	.bus_suspend		= musb_bus_suspend,
+	.bus_resume		= musb_bus_resume,
+	/* .start_port_reset	= NULL, */
+	/* .hub_irq_enable	= NULL, */
+};