Initial import

1 files changed, 2707 insertions, 0 deletions

diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
new file mode 100644
index 000000000..c3d5fc9df
--- /dev/null
+++ b/drivers/usb/musb/musb_host.c
@@ -0,0 +1,2707 @@
+/*
+ * MUSB OTG driver host support
+ *
+ * Copyright 2005 Mentor Graphics Corporation
+ * Copyright (C) 2005-2006 by Texas Instruments
+ * Copyright (C) 2006-2007 Nokia Corporation
+ * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
+ *
+ * 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/list.h>
+#include <linux/dma-mapping.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
+ *
+ * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
+ *   starvation ... nothing yet for TX, interrupt, or bulk.
+ *
+ * - 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.)
+ *
+ * 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.
+ */
+
+struct musb *hcd_to_musb(struct usb_hcd *hcd)
+{
+	return *(struct musb **) hcd->hcd_priv;
+}
+
+
+static void musb_ep_program(struct musb *musb, u8 epnum,
+			struct urb *urb, int is_out,
+			u8 *buf, u32 offset, u32 len);
+
+/*
+ * Clear TX fifo. Needed to avoid BABBLE errors.
+ */
+static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
+{
+	struct musb	*musb = ep->musb;
+	void __iomem	*epio = ep->regs;
+	u16		csr;
+	u16		lastcsr = 0;
+	int		retries = 1000;
+
+	csr = musb_readw(epio, MUSB_TXCSR);
+	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
+		if (csr != lastcsr)
+			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
+		lastcsr = csr;
+		csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_TXPKTRDY;
+		musb_writew(epio, MUSB_TXCSR, csr);
+		csr = musb_readw(epio, MUSB_TXCSR);
+		if (WARN(retries-- < 1,
+				"Could not flush host TX%d fifo: csr: %04x\n",
+				ep->epnum, csr))
+			return;
+		mdelay(1);
+	}
+}
+
+static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
+{
+	void __iomem	*epio = ep->regs;
+	u16		csr;
+	int		retries = 5;
+
+	/* scrub any data left in the fifo */
+	do {
+		csr = musb_readw(epio, MUSB_TXCSR);
+		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
+			break;
+		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
+		csr = musb_readw(epio, MUSB_TXCSR);
+		udelay(10);
+	} while (--retries);
+
+	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
+			ep->epnum, csr);
+
+	/* and reset for the next transfer */
+	musb_writew(epio, MUSB_TXCSR, 0);
+}
+
+/*
+ * 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 musb_h_tx_dma_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;
+	if (is_cppi_enabled())
+		txcsr |= MUSB_TXCSR_DMAMODE;
+	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
+}
+
+static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
+{
+	if (is_in != 0 || ep->is_shared_fifo)
+		ep->in_qh  = qh;
+	if (is_in == 0 || ep->is_shared_fifo)
+		ep->out_qh = qh;
+}
+
+static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
+{
+	return is_in ? ep->in_qh : ep->out_qh;
+}
+
+/*
+ * 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 __iomem		*mbase =  musb->mregs;
+	struct urb		*urb = next_urb(qh);
+	void			*buf = urb->transfer_buffer;
+	u32			offset = 0;
+	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;
+		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;
+		offset = urb->iso_frame_desc[0].offset;
+		len = urb->iso_frame_desc[0].length;
+		break;
+	default:		/* bulk, interrupt */
+		/* actual_length may be nonzero on retry paths */
+		buf = urb->transfer_buffer + urb->actual_length;
+		len = urb->transfer_buffer_length - urb->actual_length;
+	}
+
+	dev_dbg(musb->controller, "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 + offset, len);
+
+	/* Configure endpoint */
+	musb_ep_set_qh(hw_ep, is_in, qh);
+	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, 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:
+		dev_dbg(musb->controller, "check whether there's still time for periodic Tx\n");
+		frame = musb_readw(mbase, MUSB_FRAME);
+		/* FIXME this doesn't implement that scheduling policy ...
+		 * or handle framecounter wrapping
+		 */
+		if (1) {	/* Always assume URB_ISO_ASAP */
+			/* 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 */
+			dev_dbg(musb->controller, "SOF for %d\n", epnum);
+#if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
+			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
+#endif
+		}
+		break;
+	default:
+start:
+		dev_dbg(musb->controller, "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())
+			musb_h_tx_dma_start(hw_ep);
+	}
+}
+
+/* Context: 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)
+{
+	dev_dbg(musb->controller,
+			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
+			urb, urb->complete, status,
+			usb_pipedevice(urb->pipe),
+			usb_pipeendpoint(urb->pipe),
+			usb_pipein(urb->pipe) ? "in" : "out",
+			urb->actual_length, urb->transfer_buffer_length
+			);
+
+	usb_hcd_unlink_urb_from_ep(musb->hcd, urb);
+	spin_unlock(&musb->lock);
+	usb_hcd_giveback_urb(musb->hcd, urb, status);
+	spin_lock(&musb->lock);
+}
+
+/* For bulk/interrupt endpoints only */
+static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
+				    struct urb *urb)
+{
+	void __iomem		*epio = qh->hw_ep->regs;
+	u16			csr;
+
+	/*
+	 * FIXME: the current Mentor DMA code seems to have
+	 * problems getting toggle correct.
+	 */
+
+	if (is_in)
+		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
+	else
+		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
+
+	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
+}
+
+/*
+ * 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 = musb_ep_get_qh(hw_ep, is_in);
+	struct musb_hw_ep	*ep = qh->hw_ep;
+	int			ready = qh->is_ready;
+	int			status;
+
+	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
+
+	/* save toggle eagerly, for paranoia */
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_BULK:
+	case USB_ENDPOINT_XFER_INT:
+		musb_save_toggle(qh, is_in, urb);
+		break;
+	case USB_ENDPOINT_XFER_ISOC:
+		if (status == 0 && urb->error_count)
+			status = -EXDEV;
+		break;
+	}
+
+	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;
+		struct dma_controller	*dma = musb->dma_controller;
+
+		if (is_in) {
+			ep->rx_reinit = 1;
+			if (ep->rx_channel) {
+				dma->channel_release(ep->rx_channel);
+				ep->rx_channel = NULL;
+			}
+		} else {
+			ep->tx_reinit = 1;
+			if (ep->tx_channel) {
+				dma->channel_release(ep->tx_channel);
+				ep->tx_channel = NULL;
+			}
+		}
+
+		/* Clobber old pointers to this qh */
+		musb_ep_set_qh(ep, is_in, NULL);
+		qh->hep->hcpriv = NULL;
+
+		switch (qh->type) {
+
+		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).
+			 */
+			if (qh->mux == 1) {
+				head = qh->ring.prev;
+				list_del(&qh->ring);
+				kfree(qh);
+				qh = first_qh(head);
+				break;
+			}
+
+		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...
+			 */
+			kfree(qh);
+			qh = NULL;
+			break;
+		}
+	}
+
+	if (qh != NULL && qh->is_ready) {
+		dev_dbg(musb->controller, "... 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 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);
+	dev_dbg(musb->controller, "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++;
+			}
+			dev_dbg(musb->controller, "** 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;
+			dev_dbg(musb->controller, "** 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);
+			csr = musb_readw(ep->regs, MUSB_TXCSR);
+			musb_writew(ep->regs, MUSB_TXCSR,
+				    csr | MUSB_TXCSR_FRCDATATOG);
+		}
+
+		/*
+		 * Clear the MODE bit (and everything else) to enable Rx.
+		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
+		 */
+		if (csr & MUSB_TXCSR_DMAMODE)
+			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
+		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_write_rxfunaddr(ep->target_regs, qh->addr_reg);
+		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
+		musb_write_rxhubport(ep->target_regs, 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 */
+	/* Set RXMAXP with the FIFO size of the endpoint
+	 * to disable double buffer mode.
+	 */
+	if (musb->double_buffer_not_ok)
+		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
+	else
+		musb_writew(ep->regs, MUSB_RXMAXP,
+				qh->maxpacket | ((qh->hb_mult - 1) << 11));
+
+	ep->rx_reinit = 0;
+}
+
+static bool musb_tx_dma_program(struct dma_controller *dma,
+		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
+		struct urb *urb, u32 offset, u32 length)
+{
+	struct dma_channel	*channel = hw_ep->tx_channel;
+	void __iomem		*epio = hw_ep->regs;
+	u16			pkt_size = qh->maxpacket;
+	u16			csr;
+	u8			mode;
+
+#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
+	if (length > channel->max_len)
+		length = channel->max_len;
+
+	csr = musb_readw(epio, MUSB_TXCSR);
+	if (length > pkt_size) {
+		mode = 1;
+		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
+		/* autoset shouldn't be set in high bandwidth */
+		/*
+		 * Enable Autoset according to table
+		 * below
+		 * bulk_split hb_mult	Autoset_Enable
+		 *	0	1	Yes(Normal)
+		 *	0	>1	No(High BW ISO)
+		 *	1	1	Yes(HS bulk)
+		 *	1	>1	Yes(FS bulk)
+		 */
+		if (qh->hb_mult == 1 || (qh->hb_mult > 1 &&
+					can_bulk_split(hw_ep->musb, qh->type)))
+			csr |= MUSB_TXCSR_AUTOSET;
+	} else {
+		mode = 0;
+		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
+		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
+	}
+	channel->desired_mode = mode;
+	musb_writew(epio, MUSB_TXCSR, csr);
+#else
+	if (!is_cppi_enabled() && !tusb_dma_omap())
+		return false;
+
+	channel->actual_len = 0;
+
+	/*
+	 * TX uses "RNDIS" mode automatically but needs help
+	 * to identify the zero-length-final-packet case.
+	 */
+	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
+#endif
+
+	qh->segsize = length;
+
+	/*
+	 * Ensure the data reaches to main memory before starting
+	 * DMA transfer
+	 */
+	wmb();
+
+	if (!dma->channel_program(channel, pkt_size, mode,
+			urb->transfer_dma + offset, length)) {
+		dma->channel_release(channel);
+		hw_ep->tx_channel = NULL;
+
+		csr = musb_readw(epio, MUSB_TXCSR);
+		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
+		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
+		return false;
+	}
+	return true;
+}
+
+/*
+ * 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, int is_out,
+			u8 *buf, u32 offset, 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 = musb_ep_get_qh(hw_ep, !is_out);
+	u16			packet_sz = qh->maxpacket;
+	u8			use_dma = 1;
+	u16			csr;
+
+	dev_dbg(musb->controller, "%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);
+
+	if (is_out && !len) {
+		use_dma = 0;
+		csr = musb_readw(epio, MUSB_TXCSR);
+		csr &= ~MUSB_TXCSR_DMAENAB;
+		musb_writew(epio, MUSB_TXCSR, csr);
+		hw_ep->tx_channel = NULL;
+	}
+
+	/* candidate for DMA? */
+	dma_controller = musb->dma_controller;
+	if (use_dma && 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->intrtxe;
+		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
+
+		/* general endpoint setup */
+		if (epnum) {
+			/* flush all old state, set default */
+			/*
+			 * We could be flushing valid
+			 * packets in double buffering
+			 * case
+			 */
+			if (!hw_ep->tx_double_buffered)
+				musb_h_tx_flush_fifo(hw_ep);
+
+			/*
+			 * We must not clear the DMAMODE bit before or in
+			 * the same cycle with the DMAENAB bit, so we clear
+			 * the latter first...
+			 */
+			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
+					| MUSB_TXCSR_AUTOSET
+					| MUSB_TXCSR_DMAENAB
+					| MUSB_TXCSR_FRCDATATOG
+					| MUSB_TXCSR_H_RXSTALL
+					| MUSB_TXCSR_H_ERROR
+					| MUSB_TXCSR_TXPKTRDY
+					);
+			csr |= MUSB_TXCSR_MODE;
+
+			if (!hw_ep->tx_double_buffered) {
+				if (usb_gettoggle(urb->dev, qh->epnum, 1))
+					csr |= MUSB_TXCSR_H_WR_DATATOGGLE
+						| MUSB_TXCSR_H_DATATOGGLE;
+				else
+					csr |= MUSB_TXCSR_CLRDATATOG;
+			}
+
+			musb_writew(epio, MUSB_TXCSR, csr);
+			/* REVISIT may need to clear FLUSHFIFO ... */
+			csr &= ~MUSB_TXCSR_DMAMODE;
+			musb_writew(epio, MUSB_TXCSR, csr);
+			csr = musb_readw(epio, MUSB_TXCSR);
+		} else {
+			/* endpoint 0: just flush */
+			musb_h_ep0_flush_fifo(hw_ep);
+		}
+
+		/* target addr and (for multipoint) hub addr/port */
+		if (musb->is_multipoint) {
+			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
+			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
+			musb_write_txhubport(mbase, epnum, 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 (musb->double_buffer_not_ok) {
+				musb_writew(epio, MUSB_TXMAXP,
+						hw_ep->max_packet_sz_tx);
+			} else if (can_bulk_split(musb, qh->type)) {
+				qh->hb_mult = hw_ep->max_packet_sz_tx
+						/ packet_sz;
+				musb_writew(epio, MUSB_TXMAXP, packet_sz
+					| ((qh->hb_mult) - 1) << 11);
+			} else {
+				musb_writew(epio, MUSB_TXMAXP,
+						qh->maxpacket |
+						((qh->hb_mult - 1) << 11));
+			}
+			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);
+
+		if (dma_channel && musb_tx_dma_program(dma_controller,
+					hw_ep, qh, urb, offset, len))
+			load_count = 0;
+
+		if (load_count) {
+			/* PIO to load FIFO */
+			qh->segsize = load_count;
+			if (!buf) {
+				sg_miter_start(&qh->sg_miter, urb->sg, 1,
+						SG_MITER_ATOMIC
+						| SG_MITER_FROM_SG);
+				if (!sg_miter_next(&qh->sg_miter)) {
+					dev_err(musb->controller,
+							"error: sg"
+							"list empty\n");
+					sg_miter_stop(&qh->sg_miter);
+					goto finish;
+				}
+				buf = qh->sg_miter.addr + urb->sg->offset +
+					urb->actual_length;
+				load_count = min_t(u32, load_count,
+						qh->sg_miter.length);
+				musb_write_fifo(hw_ep, load_count, buf);
+				qh->sg_miter.consumed = load_count;
+				sg_miter_stop(&qh->sg_miter);
+			} else
+				musb_write_fifo(hw_ep, load_count, buf);
+		}
+finish:
+		/* 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 */
+			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 + offset,
+					qh->segsize);
+			if (!dma_ok) {
+				dma_controller->channel_release(dma_channel);
+				hw_ep->rx_channel = dma_channel = NULL;
+			} else
+				csr |= MUSB_RXCSR_DMAENAB;
+		}
+
+		csr |= MUSB_RXCSR_H_REQPKT;
+		dev_dbg(musb->controller, "RXCSR%d := %04x\n", epnum, csr);
+		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
+		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
+	}
+}
+
+/* Schedule next QH from musb->in_bulk/out_bulk and move the current qh to
+ * the end; avoids starvation for other endpoints.
+ */
+static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep,
+	int is_in)
+{
+	struct dma_channel	*dma;
+	struct urb		*urb;
+	void __iomem		*mbase = musb->mregs;
+	void __iomem		*epio = ep->regs;
+	struct musb_qh		*cur_qh, *next_qh;
+	u16			rx_csr, tx_csr;
+
+	musb_ep_select(mbase, ep->epnum);
+	if (is_in) {
+		dma = is_dma_capable() ? ep->rx_channel : NULL;
+
+		/* clear nak timeout bit */
+		rx_csr = musb_readw(epio, MUSB_RXCSR);
+		rx_csr |= MUSB_RXCSR_H_WZC_BITS;
+		rx_csr &= ~MUSB_RXCSR_DATAERROR;
+		musb_writew(epio, MUSB_RXCSR, rx_csr);
+
+		cur_qh = first_qh(&musb->in_bulk);
+	} else {
+		dma = is_dma_capable() ? ep->tx_channel : NULL;
+
+		/* clear nak timeout bit */
+		tx_csr = musb_readw(epio, MUSB_TXCSR);
+		tx_csr |= MUSB_TXCSR_H_WZC_BITS;
+		tx_csr &= ~MUSB_TXCSR_H_NAKTIMEOUT;
+		musb_writew(epio, MUSB_TXCSR, tx_csr);
+
+		cur_qh = first_qh(&musb->out_bulk);
+	}
+	if (cur_qh) {
+		urb = next_urb(cur_qh);
+		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
+			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
+			musb->dma_controller->channel_abort(dma);
+			urb->actual_length += dma->actual_len;
+			dma->actual_len = 0L;
+		}
+		musb_save_toggle(cur_qh, is_in, urb);
+
+		if (is_in) {
+			/* move cur_qh to end of queue */
+			list_move_tail(&cur_qh->ring, &musb->in_bulk);
+
+			/* get the next qh from musb->in_bulk */
+			next_qh = first_qh(&musb->in_bulk);
+
+			/* set rx_reinit and schedule the next qh */
+			ep->rx_reinit = 1;
+		} else {
+			/* move cur_qh to end of queue */
+			list_move_tail(&cur_qh->ring, &musb->out_bulk);
+
+			/* get the next qh from musb->out_bulk */
+			next_qh = first_qh(&musb->out_bulk);
+
+			/* set tx_reinit and schedule the next qh */
+			ep->tx_reinit = 1;
+		}
+		musb_start_urb(musb, is_in, next_qh);
+	}
+}
+
+/*
+ * 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_t(size_t, len, 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) {
+			dev_dbg(musb->controller, "start no-DATA\n");
+			break;
+		} else if (request->bRequestType & USB_DIR_IN) {
+			dev_dbg(musb->controller, "start IN-DATA\n");
+			musb->ep0_stage = MUSB_EP0_IN;
+			more = true;
+			break;
+		} else {
+			dev_dbg(musb->controller, "start OUT-DATA\n");
+			musb->ep0_stage = MUSB_EP0_OUT;
+			more = true;
+		}
+		/* FALLTHROUGH */
+	case MUSB_EP0_OUT:
+		fifo_count = min_t(size_t, qh->maxpacket,
+				   urb->transfer_buffer_length -
+				   urb->actual_length);
+		if (fifo_count) {
+			fifo_dest = (u8 *) (urb->transfer_buffer
+					+ urb->actual_length);
+			dev_dbg(musb->controller, "Sending %d byte%s to ep0 fifo %p\n",
+					fifo_count,
+					(fifo_count == 1) ? "" : "s",
+					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 musb_interrupt().
+ *
+ * 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;
+
+	dev_dbg(musb->controller, "<== 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) {
+		dev_dbg(musb->controller, "STALLING ENDPOINT\n");
+		status = -EPIPE;
+
+	} else if (csr & MUSB_CSR0_H_ERROR) {
+		dev_dbg(musb->controller, "no response, csr0 %04x\n", csr);
+		status = -EPROTO;
+
+	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
+		dev_dbg(musb->controller, "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.  That's already done
+		 * for bulk RX transfers.
+		 *
+		 * 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) {
+		dev_dbg(musb->controller, "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 {
+			musb_h_ep0_flush_fifo(hw_ep);
+		}
+
+		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_h_ep0_flush_fifo(hw_ep);
+		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;
+
+			/* disable ping token in status phase */
+			csr |= MUSB_CSR0_H_DIS_PING;
+
+			/* flag status stage */
+			musb->ep0_stage = MUSB_EP0_STATUS;
+
+			dev_dbg(musb->controller, "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			length = 0;
+	size_t			offset = 0;
+	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
+	void __iomem		*epio = hw_ep->regs;
+	struct musb_qh		*qh = hw_ep->out_qh;
+	struct urb		*urb = next_urb(qh);
+	u32			status = 0;
+	void __iomem		*mbase = musb->mregs;
+	struct dma_channel	*dma;
+	bool			transfer_pending = false;
+
+	musb_ep_select(mbase, epnum);
+	tx_csr = musb_readw(epio, MUSB_TXCSR);
+
+	/* with CPPI, DMA sometimes triggers "extra" irqs */
+	if (!urb) {
+		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
+		return;
+	}
+
+	pipe = urb->pipe;
+	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
+	dev_dbg(musb->controller, "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 */
+		dev_dbg(musb->controller, "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 */
+		dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum);
+
+		status = -ETIMEDOUT;
+
+	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
+		if (USB_ENDPOINT_XFER_BULK == qh->type && qh->mux == 1
+				&& !list_is_singular(&musb->out_bulk)) {
+			dev_dbg(musb->controller,
+				"NAK timeout on TX%d ep\n", epnum);
+			musb_bulk_nak_timeout(musb, hw_ep, 0);
+		} else {
+			dev_dbg(musb->controller,
+				"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...)
+			 * That's already done for bulk RX transfers.
+			 *
+			 * 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);
+		}
+			return;
+	}
+
+done:
+	if (status) {
+		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
+			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
+			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) {
+		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
+		return;
+	}
+
+	if (is_dma_capable() && dma && !status) {
+		/*
+		 * DMA has completed.  But if we're using DMA mode 1 (multi
+		 * packet DMA), we need a terminal TXPKTRDY interrupt before
+		 * we can consider this transfer completed, lest we trash
+		 * its last packet when writing the next URB's data.  So we
+		 * switch back to mode 0 to get that interrupt; we'll come
+		 * back here once it happens.
+		 */
+		if (tx_csr & MUSB_TXCSR_DMAMODE) {
+			/*
+			 * We shouldn't clear DMAMODE with DMAENAB set; so
+			 * clear them in a safe order.  That should be OK
+			 * once TXPKTRDY has been set (and I've never seen
+			 * it being 0 at this moment -- DMA interrupt latency
+			 * is significant) but if it hasn't been then we have
+			 * no choice but to stop being polite and ignore the
+			 * programmer's guide... :-)
+			 *
+			 * Note that we must write TXCSR with TXPKTRDY cleared
+			 * in order not to re-trigger the packet send (this bit
+			 * can't be cleared by CPU), and there's another caveat:
+			 * TXPKTRDY may be set shortly and then cleared in the
+			 * double-buffered FIFO mode, so we do an extra TXCSR
+			 * read for debouncing...
+			 */
+			tx_csr &= musb_readw(epio, MUSB_TXCSR);
+			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
+				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
+					    MUSB_TXCSR_TXPKTRDY);
+				musb_writew(epio, MUSB_TXCSR,
+					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
+			}
+			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
+				    MUSB_TXCSR_TXPKTRDY);
+			musb_writew(epio, MUSB_TXCSR,
+				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
+
+			/*
+			 * There is no guarantee that we'll get an interrupt
+			 * after clearing DMAMODE as we might have done this
+			 * too late (after TXPKTRDY was cleared by controller).
+			 * Re-read TXCSR as we have spoiled its previous value.
+			 */
+			tx_csr = musb_readw(epio, MUSB_TXCSR);
+		}
+
+		/*
+		 * We may get here from a DMA completion or TXPKTRDY interrupt.
+		 * In any case, we must check the FIFO status here and bail out
+		 * only if the FIFO still has data -- that should prevent the
+		 * "missed" TXPKTRDY interrupts and deal with double-buffered
+		 * FIFO mode too...
+		 */
+		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
+			dev_dbg(musb->controller, "DMA complete but packet still in FIFO, "
+			    "CSR %04x\n", tx_csr);
+			return;
+		}
+	}
+
+	if (!status || dma || usb_pipeisoc(pipe)) {
+		if (dma)
+			length = dma->actual_len;
+		else
+			length = qh->segsize;
+		qh->offset += length;
+
+		if (usb_pipeisoc(pipe)) {
+			struct usb_iso_packet_descriptor	*d;
+
+			d = urb->iso_frame_desc + qh->iso_idx;
+			d->actual_length = length;
+			d->status = status;
+			if (++qh->iso_idx >= urb->number_of_packets) {
+				done = true;
+			} else {
+				d++;
+				offset = d->offset;
+				length = d->length;
+			}
+		} else if (dma && urb->transfer_buffer_length == qh->offset) {
+			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) {
+				offset = qh->offset;
+				length = urb->transfer_buffer_length - offset;
+				transfer_pending = true;
+			}
+		}
+	}
+
+	/* 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);
+		return;
+	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
+		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
+				offset, length)) {
+			if (is_cppi_enabled() || tusb_dma_omap())
+				musb_h_tx_dma_start(hw_ep);
+			return;
+		}
+	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
+		dev_dbg(musb->controller, "not complete, but DMA enabled?\n");
+		return;
+	}
+
+	/*
+	 * PIO: start next packet in this URB.
+	 *
+	 * 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...
+	 */
+	if (length > qh->maxpacket)
+		length = qh->maxpacket;
+	/* Unmap the buffer so that CPU can use it */
+	usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
+
+	/*
+	 * We need to map sg if the transfer_buffer is
+	 * NULL.
+	 */
+	if (!urb->transfer_buffer)
+		qh->use_sg = true;
+
+	if (qh->use_sg) {
+		/* sg_miter_start is already done in musb_ep_program */
+		if (!sg_miter_next(&qh->sg_miter)) {
+			dev_err(musb->controller, "error: sg list empty\n");
+			sg_miter_stop(&qh->sg_miter);
+			status = -EINVAL;
+			goto done;
+		}
+		urb->transfer_buffer = qh->sg_miter.addr;
+		length = min_t(u32, length, qh->sg_miter.length);
+		musb_write_fifo(hw_ep, length, urb->transfer_buffer);
+		qh->sg_miter.consumed = length;
+		sg_miter_stop(&qh->sg_miter);
+	} else {
+		musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
+	}
+
+	qh->segsize = length;
+
+	if (qh->use_sg) {
+		if (offset + length >= urb->transfer_buffer_length)
+			qh->use_sg = false;
+	}
+
+	musb_ep_select(mbase, epnum);
+	musb_writew(epio, MUSB_TXCSR,
+			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
+}
+
+
+#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;
+	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
+
+	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??)
+		 */
+		dev_dbg(musb->controller, "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;
+
+	dev_dbg(musb->controller, "<== 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) {
+		dev_dbg(musb->controller, "RX end %d STALL\n", epnum);
+
+		/* stall; record URB status */
+		status = -EPIPE;
+
+	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
+		dev_dbg(musb->controller, "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) {
+			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
+
+			/* NOTE: NAKing is *NOT* an error, so we want to
+			 * continue.  Except ... if there's a request for
+			 * another QH, use that instead of starving it.
+			 *
+			 * Devices like Ethernet and serial adapters keep
+			 * reads posted at all times, which will starve
+			 * other devices without this logic.
+			 */
+			if (usb_pipebulk(urb->pipe)
+					&& qh->mux == 1
+					&& !list_is_singular(&musb->in_bulk)) {
+				musb_bulk_nak_timeout(musb, hw_ep, 1);
+				return;
+			}
+			musb_ep_select(mbase, epnum);
+			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
+			rx_csr &= ~MUSB_RXCSR_DATAERROR;
+			musb_writew(epio, MUSB_RXCSR, rx_csr);
+
+			goto finish;
+		} else {
+			dev_dbg(musb->controller, "RX end %d ISO data error\n", epnum);
+			/* packet error reported later */
+			iso_err = true;
+		}
+	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
+		dev_dbg(musb->controller, "end %d high bandwidth incomplete ISO packet RX\n",
+				epnum);
+		status = -EPROTO;
+	}
+
+	/* 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;
+			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 */
+
+#if !defined(CONFIG_USB_INVENTRA_DMA) && !defined(CONFIG_USB_UX500_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;
+			musb->dma_controller->channel_abort(dma);
+			xfer_len = dma->actual_len;
+			done = true;
+		}
+
+		dev_dbg(musb->controller, "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);
+
+#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA) || \
+	defined(CONFIG_USB_TI_CPPI41_DMA)
+		if (usb_pipeisoc(pipe)) {
+			struct usb_iso_packet_descriptor *d;
+
+			d = urb->iso_frame_desc + qh->iso_idx;
+			d->actual_length = xfer_len;
+
+			/* even if there was an error, we did the dma
+			 * for iso_frame_desc->length
+			 */
+			if (d->status != -EILSEQ && d->status != -EOVERFLOW)
+				d->status = 0;
+
+			if (++qh->iso_idx >= urb->number_of_packets) {
+				done = true;
+			} else {
+#if defined(CONFIG_USB_TI_CPPI41_DMA)
+				struct dma_controller   *c;
+				dma_addr_t *buf;
+				u32 length, ret;
+
+				c = musb->dma_controller;
+				buf = (void *)
+					urb->iso_frame_desc[qh->iso_idx].offset
+					+ (u32)urb->transfer_dma;
+
+				length =
+					urb->iso_frame_desc[qh->iso_idx].length;
+
+				val |= MUSB_RXCSR_DMAENAB;
+				musb_writew(hw_ep->regs, MUSB_RXCSR, val);
+
+				ret = c->channel_program(dma, qh->maxpacket,
+						0, (u32) buf, length);
+#endif
+				done = false;
+			}
+
+		} else  {
+			/* 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
+				|| dma->rx_packet_done);
+		}
+
+		/* 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);
+		}
+
+		dev_dbg(musb->controller, "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 */
+#if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA) || \
+	defined(CONFIG_USB_TI_CPPI41_DMA)
+		if (dma) {
+			struct dma_controller	*c;
+			u16			rx_count;
+			int			ret, length;
+			dma_addr_t		buf;
+
+			rx_count = musb_readw(epio, MUSB_RXCOUNT);
+
+			dev_dbg(musb->controller, "RX%d count %d, buffer 0x%llx len %d/%d\n",
+					epnum, rx_count,
+					(unsigned long long) urb->transfer_dma
+					+ urb->actual_length,
+					qh->offset,
+					urb->transfer_buffer_length);
+
+			c = musb->dma_controller;
+
+			if (usb_pipeisoc(pipe)) {
+				int d_status = 0;
+				struct usb_iso_packet_descriptor *d;
+
+				d = urb->iso_frame_desc + qh->iso_idx;
+
+				if (iso_err) {
+					d_status = -EILSEQ;
+					urb->error_count++;
+				}
+				if (rx_count > d->length) {
+					if (d_status == 0) {
+						d_status = -EOVERFLOW;
+						urb->error_count++;
+					}
+					dev_dbg(musb->controller, "** OVERFLOW %d into %d\n",\
+					    rx_count, d->length);
+
+					length = d->length;
+				} else
+					length = rx_count;
+				d->status = d_status;
+				buf = urb->transfer_dma + d->offset;
+			} else {
+				length = rx_count;
+				buf = urb->transfer_dma +
+						urb->actual_length;
+			}
+
+			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;
+			if (rx_count < hw_ep->max_packet_sz_rx) {
+				length = rx_count;
+				dma->desired_mode = 0;
+			} else {
+				length = urb->transfer_buffer_length;
+			}
+#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_DMAENAB;
+
+			/* autoclear shouldn't be set in high bandwidth */
+			if (qh->hb_mult == 1)
+				val |= MUSB_RXCSR_AUTOCLEAR;
+
+			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, buf, length);
+
+			if (!ret) {
+				c->channel_release(dma);
+				hw_ep->rx_channel = NULL;
+				dma = NULL;
+				val = musb_readw(epio, MUSB_RXCSR);
+				val &= ~(MUSB_RXCSR_DMAENAB
+					| MUSB_RXCSR_H_AUTOREQ
+					| MUSB_RXCSR_AUTOCLEAR);
+				musb_writew(epio, MUSB_RXCSR, val);
+			}
+		}
+#endif	/* Mentor DMA */
+
+		if (!dma) {
+			unsigned int received_len;
+
+			/* Unmap the buffer so that CPU can use it */
+			usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
+
+			/*
+			 * We need to map sg if the transfer_buffer is
+			 * NULL.
+			 */
+			if (!urb->transfer_buffer) {
+				qh->use_sg = true;
+				sg_miter_start(&qh->sg_miter, urb->sg, 1,
+						sg_flags);
+			}
+
+			if (qh->use_sg) {
+				if (!sg_miter_next(&qh->sg_miter)) {
+					dev_err(musb->controller, "error: sg list empty\n");
+					sg_miter_stop(&qh->sg_miter);
+					status = -EINVAL;
+					done = true;
+					goto finish;
+				}
+				urb->transfer_buffer = qh->sg_miter.addr;
+				received_len = urb->actual_length;
+				qh->offset = 0x0;
+				done = musb_host_packet_rx(musb, urb, epnum,
+						iso_err);
+				/* Calculate the number of bytes received */
+				received_len = urb->actual_length -
+					received_len;
+				qh->sg_miter.consumed = received_len;
+				sg_miter_stop(&qh->sg_miter);
+			} else {
+				done = musb_host_packet_rx(musb, urb,
+						epnum, iso_err);
+			}
+			dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
+		}
+	}
+
+finish:
+	urb->actual_length += xfer_len;
+	qh->offset += xfer_len;
+	if (done) {
+		if (qh->use_sg)
+			qh->use_sg = false;
+
+		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 = 0;
+	int			best_diff;
+	int			best_end, epnum;
+	struct musb_hw_ep	*hw_ep = NULL;
+	struct list_head	*head = NULL;
+	u8			toggle;
+	u8			txtype;
+	struct urb		*urb = next_urb(qh);
+
+	/* use fixed hardware for control and bulk */
+	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
+		head = &musb->control;
+		hw_ep = musb->control_ep;
+		goto success;
+	}
+
+	/* else, periodic transfers get muxed to other 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.
+	 */
+	best_diff = 4096;
+	best_end = -1;
+
+	for (epnum = 1, hw_ep = musb->endpoints + 1;
+			epnum < musb->nr_endpoints;
+			epnum++, hw_ep++) {
+		int	diff;
+
+		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
+			continue;
+
+		if (hw_ep == musb->bulk_ep)
+			continue;
+
+		if (is_in)
+			diff = hw_ep->max_packet_sz_rx;
+		else
+			diff = hw_ep->max_packet_sz_tx;
+		diff -= (qh->maxpacket * qh->hb_mult);
+
+		if (diff >= 0 && best_diff > diff) {
+
+			/*
+			 * Mentor controller has a bug in that if we schedule
+			 * a BULK Tx transfer on an endpoint that had earlier
+			 * handled ISOC then the BULK transfer has to start on
+			 * a zero toggle.  If the BULK transfer starts on a 1
+			 * toggle then this transfer will fail as the mentor
+			 * controller starts the Bulk transfer on a 0 toggle
+			 * irrespective of the programming of the toggle bits
+			 * in the TXCSR register.  Check for this condition
+			 * while allocating the EP for a Tx Bulk transfer.  If
+			 * so skip this EP.
+			 */
+			hw_ep = musb->endpoints + epnum;
+			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
+			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
+					>> 4) & 0x3;
+			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
+				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
+				continue;
+
+			best_diff = diff;
+			best_end = epnum;
+		}
+	}
+	/* use bulk reserved ep1 if no other ep is free */
+	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
+		hw_ep = musb->bulk_ep;
+		if (is_in)
+			head = &musb->in_bulk;
+		else
+			head = &musb->out_bulk;
+
+		/* Enable bulk RX/TX NAK timeout scheme when bulk requests are
+		 * multiplexed. This scheme does not work in high speed to full
+		 * speed scenario as NAK interrupts are not coming from a
+		 * full speed device connected to a high speed device.
+		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
+		 * 4 (8 frame or 8ms) for FS device.
+		 */
+		if (qh->dev)
+			qh->intv_reg =
+				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
+		goto success;
+	} else if (best_end < 0) {
+		return -ENOSPC;
+	}
+
+	idle = 1;
+	qh->mux = 0;
+	hw_ep = musb->endpoints + best_end;
+	dev_dbg(musb->controller, "qh %p periodic slot %d\n", qh, best_end);
+success:
+	if (head) {
+		idle = list_empty(head);
+		list_add_tail(&qh->ring, head);
+		qh->mux = 1;
+	}
+	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;
+	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);
+	qh = ret ? NULL : hep->hcpriv;
+	if (qh)
+		urb->hcpriv = qh;
+	spin_unlock_irqrestore(&musb->lock, flags);
+
+	/* DMA mapping was already done, if needed, and this urb is on
+	 * hep->urb_list now ... so we're done, 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 || ret)
+		return ret;
+
+	/* 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) {
+		spin_lock_irqsave(&musb->lock, flags);
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
+		spin_unlock_irqrestore(&musb->lock, flags);
+		return -ENOMEM;
+	}
+
+	qh->hep = hep;
+	qh->dev = urb->dev;
+	INIT_LIST_HEAD(&qh->ring);
+	qh->is_ready = 1;
+
+	qh->maxpacket = usb_endpoint_maxp(epd);
+	qh->type = usb_endpoint_type(epd);
+
+	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
+	 * Some musb cores don't support high bandwidth ISO transfers; and
+	 * we don't (yet!) support high bandwidth interrupt transfers.
+	 */
+	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
+	if (qh->hb_mult > 1) {
+		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
+
+		if (ok)
+			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
+				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
+		if (!ok) {
+			ret = -EMSGSIZE;
+			goto done;
+		}
+		qh->maxpacket &= 0x7ff;
+	}
+
+	qh->epnum = usb_endpoint_num(epd);
+
+	/* 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 */
+	switch (qh->type) {
+	case USB_ENDPOINT_XFER_INT:
+		/*
+		 * Full/low speeds use the  linear encoding,
+		 * high speed uses the logarithmic encoding.
+		 */
+		if (urb->dev->speed <= USB_SPEED_FULL) {
+			interval = max_t(u8, epd->bInterval, 1);
+			break;
+		}
+		/* FALLTHROUGH */
+	case USB_ENDPOINT_XFER_ISOC:
+		/* ISO always uses logarithmic encoding */
+		interval = min_t(u8, epd->bInterval, 16);
+		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.  That's perfectly normal
+		 * for reads from network or serial adapters ... so we have
+		 * partial NAKlimit support for bulk RX.
+		 *
+		 * The upside of disabling it is simpler transfer scheduling.
+		 */
+		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;
+				if (urb->dev->tt->hub)
+					qh->h_addr_reg =
+						(u8) urb->dev->tt->hub->devnum;
+				if (urb->dev->tt->multi)
+					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 || !next_urb(qh)) {
+		/* some concurrent activity submitted another urb to hep...
+		 * odd, rare, error prone, but legal.
+		 */
+		kfree(qh);
+		qh = NULL;
+		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) {
+		spin_lock_irqsave(&musb->lock, flags);
+		usb_hcd_unlink_urb_from_ep(hcd, urb);
+		spin_unlock_irqrestore(&musb->lock, flags);
+		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)
+{
+	struct musb_hw_ep	*ep = qh->hw_ep;
+	struct musb		*musb = ep->musb;
+	void __iomem		*epio = ep->regs;
+	unsigned		hw_end = ep->epnum;
+	void __iomem		*regs = ep->musb->mregs;
+	int			is_in = usb_pipein(urb->pipe);
+	int			status = 0;
+	u16			csr;
+
+	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);
+			dev_dbg(musb->controller,
+				"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 (ep->epnum && 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 if (ep->epnum) {
+		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);
+	} else  {
+		musb_h_ep0_flush_fifo(ep);
+	}
+	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;
+	unsigned long		flags;
+	int			is_in  = usb_pipein(urb->pipe);
+	int			ret;
+
+	dev_dbg(musb->controller, "urb=%p, dev%d ep%d%s\n", urb,
+			usb_pipedevice(urb->pipe),
+			usb_pipeendpoint(urb->pipe),
+			is_in ? "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; that's any URB not at the head of an
+	 * endpoint queue, unless someday we get real DMA queues.  And even
+	 * if it's at the head, 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.
+	 *
+	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
+	 */
+	if (!qh->is_ready
+			|| urb->urb_list.prev != &qh->hep->urb_list
+			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
+		int	ready = qh->is_ready;
+
+		qh->is_ready = 0;
+		musb_giveback(musb, urb, 0);
+		qh->is_ready = ready;
+
+		/* If nothing else (usually musb_giveback) is using it
+		 * and its URB list has emptied, recycle this qh.
+		 */
+		if (ready && list_empty(&qh->hep->urb_list)) {
+			qh->hep->hcpriv = NULL;
+			list_del(&qh->ring);
+			kfree(qh);
+		}
+	} else
+		ret = musb_cleanup_urb(urb, qh);
+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			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
+	unsigned long		flags;
+	struct musb		*musb = hcd_to_musb(hcd);
+	struct musb_qh		*qh;
+	struct urb		*urb;
+
+	spin_lock_irqsave(&musb->lock, flags);
+
+	qh = hep->hcpriv;
+	if (qh == NULL)
+		goto exit;
+
+	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
+
+	/* Kick the first URB off the hardware, if needed */
+	qh->is_ready = 0;
+	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
+		urb = next_urb(qh);
+
+		/* make software (then hardware) stop ASAP */
+		if (!urb->unlinked)
+			urb->status = -ESHUTDOWN;
+
+		/* cleanup */
+		musb_cleanup_urb(urb, qh);
+
+		/* Then nuke all the others ... and advance the
+		 * queue on hw_ep (e.g. bulk ring) when we're done.
+		 */
+		while (!list_empty(&hep->urb_list)) {
+			urb = next_urb(qh);
+			urb->status = -ESHUTDOWN;
+			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
+		}
+	} else {
+		/* Just empty the queue; the hardware is busy with
+		 * other transfers, and since !qh->is_ready nothing
+		 * will activate any of these as it advances.
+		 */
+		while (!list_empty(&hep->urb_list))
+			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
+
+		hep->hcpriv = NULL;
+		list_del(&qh->ring);
+		kfree(qh);
+	}
+exit:
+	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);
+	u8		devctl;
+
+	musb_port_suspend(musb, true);
+
+	if (!is_host_active(musb))
+		return 0;
+
+	switch (musb->xceiv->otg->state) {
+	case OTG_STATE_A_SUSPEND:
+		return 0;
+	case OTG_STATE_A_WAIT_VRISE:
+		/* ID could be grounded even if there's no device
+		 * on the other end of the cable.  NOTE that the
+		 * A_WAIT_VRISE timers are messy with MUSB...
+		 */
+		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
+		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
+			musb->xceiv->otg->state = OTG_STATE_A_WAIT_BCON;
+		break;
+	default:
+		break;
+	}
+
+	if (musb->is_active) {
+		WARNING("trying to suspend as %s while active\n",
+				usb_otg_state_string(musb->xceiv->otg->state));
+		return -EBUSY;
+	} else
+		return 0;
+}
+
+static int musb_bus_resume(struct usb_hcd *hcd)
+{
+	struct musb *musb = hcd_to_musb(hcd);
+
+	if (musb->config &&
+	    musb->config->host_port_deassert_reset_at_resume)
+		musb_port_reset(musb, false);
+
+	return 0;
+}
+
+#ifndef CONFIG_MUSB_PIO_ONLY
+
+#define MUSB_USB_DMA_ALIGN 4
+
+struct musb_temp_buffer {
+	void *kmalloc_ptr;
+	void *old_xfer_buffer;
+	u8 data[0];
+};
+
+static void musb_free_temp_buffer(struct urb *urb)
+{
+	enum dma_data_direction dir;
+	struct musb_temp_buffer *temp;
+
+	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
+		return;
+
+	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	temp = container_of(urb->transfer_buffer, struct musb_temp_buffer,
+			    data);
+
+	if (dir == DMA_FROM_DEVICE) {
+		memcpy(temp->old_xfer_buffer, temp->data,
+		       urb->transfer_buffer_length);
+	}
+	urb->transfer_buffer = temp->old_xfer_buffer;
+	kfree(temp->kmalloc_ptr);
+
+	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
+}
+
+static int musb_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
+{
+	enum dma_data_direction dir;
+	struct musb_temp_buffer *temp;
+	void *kmalloc_ptr;
+	size_t kmalloc_size;
+
+	if (urb->num_sgs || urb->sg ||
+	    urb->transfer_buffer_length == 0 ||
+	    !((uintptr_t)urb->transfer_buffer & (MUSB_USB_DMA_ALIGN - 1)))
+		return 0;
+
+	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+
+	/* Allocate a buffer with enough padding for alignment */
+	kmalloc_size = urb->transfer_buffer_length +
+		sizeof(struct musb_temp_buffer) + MUSB_USB_DMA_ALIGN - 1;
+
+	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
+	if (!kmalloc_ptr)
+		return -ENOMEM;
+
+	/* Position our struct temp_buffer such that data is aligned */
+	temp = PTR_ALIGN(kmalloc_ptr, MUSB_USB_DMA_ALIGN);
+
+
+	temp->kmalloc_ptr = kmalloc_ptr;
+	temp->old_xfer_buffer = urb->transfer_buffer;
+	if (dir == DMA_TO_DEVICE)
+		memcpy(temp->data, urb->transfer_buffer,
+		       urb->transfer_buffer_length);
+	urb->transfer_buffer = temp->data;
+
+	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
+
+	return 0;
+}
+
+static int musb_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
+				      gfp_t mem_flags)
+{
+	struct musb	*musb = hcd_to_musb(hcd);
+	int ret;
+
+	/*
+	 * The DMA engine in RTL1.8 and above cannot handle
+	 * DMA addresses that are not aligned to a 4 byte boundary.
+	 * For such engine implemented (un)map_urb_for_dma hooks.
+	 * Do not use these hooks for RTL<1.8
+	 */
+	if (musb->hwvers < MUSB_HWVERS_1800)
+		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
+
+	ret = musb_alloc_temp_buffer(urb, mem_flags);
+	if (ret)
+		return ret;
+
+	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
+	if (ret)
+		musb_free_temp_buffer(urb);
+
+	return ret;
+}
+
+static void musb_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
+{
+	struct musb	*musb = hcd_to_musb(hcd);
+
+	usb_hcd_unmap_urb_for_dma(hcd, urb);
+
+	/* Do not use this hook for RTL<1.8 (see description above) */
+	if (musb->hwvers < MUSB_HWVERS_1800)
+		return;
+
+	musb_free_temp_buffer(urb);
+}
+#endif /* !CONFIG_MUSB_PIO_ONLY */
+
+static 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 | HCD_BH,
+
+	/* 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,
+
+#ifndef CONFIG_MUSB_PIO_ONLY
+	.map_urb_for_dma	= musb_map_urb_for_dma,
+	.unmap_urb_for_dma	= musb_unmap_urb_for_dma,
+#endif
+
+	.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, */
+};
+
+int musb_host_alloc(struct musb *musb)
+{
+	struct device	*dev = musb->controller;
+
+	/* usbcore sets dev->driver_data to hcd, and sometimes uses that... */
+	musb->hcd = usb_create_hcd(&musb_hc_driver, dev, dev_name(dev));
+	if (!musb->hcd)
+		return -EINVAL;
+
+	*musb->hcd->hcd_priv = (unsigned long) musb;
+	musb->hcd->self.uses_pio_for_control = 1;
+	musb->hcd->uses_new_polling = 1;
+	musb->hcd->has_tt = 1;
+
+	return 0;
+}
+
+void musb_host_cleanup(struct musb *musb)
+{
+	if (musb->port_mode == MUSB_PORT_MODE_GADGET)
+		return;
+	usb_remove_hcd(musb->hcd);
+}
+
+void musb_host_free(struct musb *musb)
+{
+	usb_put_hcd(musb->hcd);
+}
+
+int musb_host_setup(struct musb *musb, int power_budget)
+{
+	int ret;
+	struct usb_hcd *hcd = musb->hcd;
+
+	MUSB_HST_MODE(musb);
+	musb->xceiv->otg->default_a = 1;
+	musb->xceiv->otg->state = OTG_STATE_A_IDLE;
+
+	otg_set_host(musb->xceiv->otg, &hcd->self);
+	hcd->self.otg_port = 1;
+	musb->xceiv->otg->host = &hcd->self;
+	hcd->power_budget = 2 * (power_budget ? : 250);
+
+	ret = usb_add_hcd(hcd, 0, 0);
+	if (ret < 0)
+		return ret;
+
+	device_wakeup_enable(hcd->self.controller);
+	return 0;
+}
+
+void musb_host_resume_root_hub(struct musb *musb)
+{
+	usb_hcd_resume_root_hub(musb->hcd);
+}
+
+void musb_host_poke_root_hub(struct musb *musb)
+{
+	MUSB_HST_MODE(musb);
+	if (musb->hcd->status_urb)
+		usb_hcd_poll_rh_status(musb->hcd);
+	else
+		usb_hcd_resume_root_hub(musb->hcd);
+}