xref: /openbmc/linux/drivers/usb/musb/musb_host.c (revision ee89bd6b)
1 /*
2  * MUSB OTG driver host support
3  *
4  * Copyright 2005 Mentor Graphics Corporation
5  * Copyright (C) 2005-2006 by Texas Instruments
6  * Copyright (C) 2006-2007 Nokia Corporation
7  * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * version 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
21  * 02110-1301 USA
22  *
23  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
24  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
26  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
30  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  */
35 
36 #include <linux/module.h>
37 #include <linux/kernel.h>
38 #include <linux/delay.h>
39 #include <linux/sched.h>
40 #include <linux/slab.h>
41 #include <linux/errno.h>
42 #include <linux/init.h>
43 #include <linux/list.h>
44 #include <linux/dma-mapping.h>
45 
46 #include "musb_core.h"
47 #include "musb_host.h"
48 
49 
50 /* MUSB HOST status 22-mar-2006
51  *
52  * - There's still lots of partial code duplication for fault paths, so
53  *   they aren't handled as consistently as they need to be.
54  *
55  * - PIO mostly behaved when last tested.
56  *     + including ep0, with all usbtest cases 9, 10
57  *     + usbtest 14 (ep0out) doesn't seem to run at all
58  *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
59  *       configurations, but otherwise double buffering passes basic tests.
60  *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
61  *
62  * - DMA (CPPI) ... partially behaves, not currently recommended
63  *     + about 1/15 the speed of typical EHCI implementations (PCI)
64  *     + RX, all too often reqpkt seems to misbehave after tx
65  *     + TX, no known issues (other than evident silicon issue)
66  *
67  * - DMA (Mentor/OMAP) ...has at least toggle update problems
68  *
69  * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
70  *   starvation ... nothing yet for TX, interrupt, or bulk.
71  *
72  * - Not tested with HNP, but some SRP paths seem to behave.
73  *
74  * NOTE 24-August-2006:
75  *
76  * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
77  *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
78  *   mostly works, except that with "usbnet" it's easy to trigger cases
79  *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
80  *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
81  *   although ARP RX wins.  (That test was done with a full speed link.)
82  */
83 
84 
85 /*
86  * NOTE on endpoint usage:
87  *
88  * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
89  * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
90  * (Yes, bulk _could_ use more of the endpoints than that, and would even
91  * benefit from it.)
92  *
93  * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
94  * So far that scheduling is both dumb and optimistic:  the endpoint will be
95  * "claimed" until its software queue is no longer refilled.  No multiplexing
96  * of transfers between endpoints, or anything clever.
97  */
98 
99 
100 static void musb_ep_program(struct musb *musb, u8 epnum,
101 			struct urb *urb, int is_out,
102 			u8 *buf, u32 offset, u32 len);
103 
104 /*
105  * Clear TX fifo. Needed to avoid BABBLE errors.
106  */
107 static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
108 {
109 	struct musb	*musb = ep->musb;
110 	void __iomem	*epio = ep->regs;
111 	u16		csr;
112 	u16		lastcsr = 0;
113 	int		retries = 1000;
114 
115 	csr = musb_readw(epio, MUSB_TXCSR);
116 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
117 		if (csr != lastcsr)
118 			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
119 		lastcsr = csr;
120 		csr |= MUSB_TXCSR_FLUSHFIFO;
121 		musb_writew(epio, MUSB_TXCSR, csr);
122 		csr = musb_readw(epio, MUSB_TXCSR);
123 		if (WARN(retries-- < 1,
124 				"Could not flush host TX%d fifo: csr: %04x\n",
125 				ep->epnum, csr))
126 			return;
127 		mdelay(1);
128 	}
129 }
130 
131 static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
132 {
133 	void __iomem	*epio = ep->regs;
134 	u16		csr;
135 	int		retries = 5;
136 
137 	/* scrub any data left in the fifo */
138 	do {
139 		csr = musb_readw(epio, MUSB_TXCSR);
140 		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
141 			break;
142 		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
143 		csr = musb_readw(epio, MUSB_TXCSR);
144 		udelay(10);
145 	} while (--retries);
146 
147 	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
148 			ep->epnum, csr);
149 
150 	/* and reset for the next transfer */
151 	musb_writew(epio, MUSB_TXCSR, 0);
152 }
153 
154 /*
155  * Start transmit. Caller is responsible for locking shared resources.
156  * musb must be locked.
157  */
158 static inline void musb_h_tx_start(struct musb_hw_ep *ep)
159 {
160 	u16	txcsr;
161 
162 	/* NOTE: no locks here; caller should lock and select EP */
163 	if (ep->epnum) {
164 		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
165 		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
166 		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
167 	} else {
168 		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
169 		musb_writew(ep->regs, MUSB_CSR0, txcsr);
170 	}
171 
172 }
173 
174 static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
175 {
176 	u16	txcsr;
177 
178 	/* NOTE: no locks here; caller should lock and select EP */
179 	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
180 	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
181 	if (is_cppi_enabled())
182 		txcsr |= MUSB_TXCSR_DMAMODE;
183 	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
184 }
185 
186 static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
187 {
188 	if (is_in != 0 || ep->is_shared_fifo)
189 		ep->in_qh  = qh;
190 	if (is_in == 0 || ep->is_shared_fifo)
191 		ep->out_qh = qh;
192 }
193 
194 static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
195 {
196 	return is_in ? ep->in_qh : ep->out_qh;
197 }
198 
199 /*
200  * Start the URB at the front of an endpoint's queue
201  * end must be claimed from the caller.
202  *
203  * Context: controller locked, irqs blocked
204  */
205 static void
206 musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
207 {
208 	u16			frame;
209 	u32			len;
210 	void __iomem		*mbase =  musb->mregs;
211 	struct urb		*urb = next_urb(qh);
212 	void			*buf = urb->transfer_buffer;
213 	u32			offset = 0;
214 	struct musb_hw_ep	*hw_ep = qh->hw_ep;
215 	unsigned		pipe = urb->pipe;
216 	u8			address = usb_pipedevice(pipe);
217 	int			epnum = hw_ep->epnum;
218 
219 	/* initialize software qh state */
220 	qh->offset = 0;
221 	qh->segsize = 0;
222 
223 	/* gather right source of data */
224 	switch (qh->type) {
225 	case USB_ENDPOINT_XFER_CONTROL:
226 		/* control transfers always start with SETUP */
227 		is_in = 0;
228 		musb->ep0_stage = MUSB_EP0_START;
229 		buf = urb->setup_packet;
230 		len = 8;
231 		break;
232 	case USB_ENDPOINT_XFER_ISOC:
233 		qh->iso_idx = 0;
234 		qh->frame = 0;
235 		offset = urb->iso_frame_desc[0].offset;
236 		len = urb->iso_frame_desc[0].length;
237 		break;
238 	default:		/* bulk, interrupt */
239 		/* actual_length may be nonzero on retry paths */
240 		buf = urb->transfer_buffer + urb->actual_length;
241 		len = urb->transfer_buffer_length - urb->actual_length;
242 	}
243 
244 	dev_dbg(musb->controller, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
245 			qh, urb, address, qh->epnum,
246 			is_in ? "in" : "out",
247 			({char *s; switch (qh->type) {
248 			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
249 			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
250 			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
251 			default:			s = "-intr"; break;
252 			}; s; }),
253 			epnum, buf + offset, len);
254 
255 	/* Configure endpoint */
256 	musb_ep_set_qh(hw_ep, is_in, qh);
257 	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
258 
259 	/* transmit may have more work: start it when it is time */
260 	if (is_in)
261 		return;
262 
263 	/* determine if the time is right for a periodic transfer */
264 	switch (qh->type) {
265 	case USB_ENDPOINT_XFER_ISOC:
266 	case USB_ENDPOINT_XFER_INT:
267 		dev_dbg(musb->controller, "check whether there's still time for periodic Tx\n");
268 		frame = musb_readw(mbase, MUSB_FRAME);
269 		/* FIXME this doesn't implement that scheduling policy ...
270 		 * or handle framecounter wrapping
271 		 */
272 		if ((urb->transfer_flags & URB_ISO_ASAP)
273 				|| (frame >= urb->start_frame)) {
274 			/* REVISIT the SOF irq handler shouldn't duplicate
275 			 * this code; and we don't init urb->start_frame...
276 			 */
277 			qh->frame = 0;
278 			goto start;
279 		} else {
280 			qh->frame = urb->start_frame;
281 			/* enable SOF interrupt so we can count down */
282 			dev_dbg(musb->controller, "SOF for %d\n", epnum);
283 #if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
284 			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
285 #endif
286 		}
287 		break;
288 	default:
289 start:
290 		dev_dbg(musb->controller, "Start TX%d %s\n", epnum,
291 			hw_ep->tx_channel ? "dma" : "pio");
292 
293 		if (!hw_ep->tx_channel)
294 			musb_h_tx_start(hw_ep);
295 		else if (is_cppi_enabled() || tusb_dma_omap())
296 			musb_h_tx_dma_start(hw_ep);
297 	}
298 }
299 
300 /* Context: caller owns controller lock, IRQs are blocked */
301 static void musb_giveback(struct musb *musb, struct urb *urb, int status)
302 __releases(musb->lock)
303 __acquires(musb->lock)
304 {
305 	dev_dbg(musb->controller,
306 			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
307 			urb, urb->complete, status,
308 			usb_pipedevice(urb->pipe),
309 			usb_pipeendpoint(urb->pipe),
310 			usb_pipein(urb->pipe) ? "in" : "out",
311 			urb->actual_length, urb->transfer_buffer_length
312 			);
313 
314 	usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
315 	spin_unlock(&musb->lock);
316 	usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
317 	spin_lock(&musb->lock);
318 }
319 
320 /* For bulk/interrupt endpoints only */
321 static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
322 				    struct urb *urb)
323 {
324 	void __iomem		*epio = qh->hw_ep->regs;
325 	u16			csr;
326 
327 	/*
328 	 * FIXME: the current Mentor DMA code seems to have
329 	 * problems getting toggle correct.
330 	 */
331 
332 	if (is_in)
333 		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
334 	else
335 		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
336 
337 	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
338 }
339 
340 /*
341  * Advance this hardware endpoint's queue, completing the specified URB and
342  * advancing to either the next URB queued to that qh, or else invalidating
343  * that qh and advancing to the next qh scheduled after the current one.
344  *
345  * Context: caller owns controller lock, IRQs are blocked
346  */
347 static void musb_advance_schedule(struct musb *musb, struct urb *urb,
348 				  struct musb_hw_ep *hw_ep, int is_in)
349 {
350 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
351 	struct musb_hw_ep	*ep = qh->hw_ep;
352 	int			ready = qh->is_ready;
353 	int			status;
354 
355 	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
356 
357 	/* save toggle eagerly, for paranoia */
358 	switch (qh->type) {
359 	case USB_ENDPOINT_XFER_BULK:
360 	case USB_ENDPOINT_XFER_INT:
361 		musb_save_toggle(qh, is_in, urb);
362 		break;
363 	case USB_ENDPOINT_XFER_ISOC:
364 		if (status == 0 && urb->error_count)
365 			status = -EXDEV;
366 		break;
367 	}
368 
369 	qh->is_ready = 0;
370 	musb_giveback(musb, urb, status);
371 	qh->is_ready = ready;
372 
373 	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
374 	 * invalidate qh as soon as list_empty(&hep->urb_list)
375 	 */
376 	if (list_empty(&qh->hep->urb_list)) {
377 		struct list_head	*head;
378 		struct dma_controller	*dma = musb->dma_controller;
379 
380 		if (is_in) {
381 			ep->rx_reinit = 1;
382 			if (ep->rx_channel) {
383 				dma->channel_release(ep->rx_channel);
384 				ep->rx_channel = NULL;
385 			}
386 		} else {
387 			ep->tx_reinit = 1;
388 			if (ep->tx_channel) {
389 				dma->channel_release(ep->tx_channel);
390 				ep->tx_channel = NULL;
391 			}
392 		}
393 
394 		/* Clobber old pointers to this qh */
395 		musb_ep_set_qh(ep, is_in, NULL);
396 		qh->hep->hcpriv = NULL;
397 
398 		switch (qh->type) {
399 
400 		case USB_ENDPOINT_XFER_CONTROL:
401 		case USB_ENDPOINT_XFER_BULK:
402 			/* fifo policy for these lists, except that NAKing
403 			 * should rotate a qh to the end (for fairness).
404 			 */
405 			if (qh->mux == 1) {
406 				head = qh->ring.prev;
407 				list_del(&qh->ring);
408 				kfree(qh);
409 				qh = first_qh(head);
410 				break;
411 			}
412 
413 		case USB_ENDPOINT_XFER_ISOC:
414 		case USB_ENDPOINT_XFER_INT:
415 			/* this is where periodic bandwidth should be
416 			 * de-allocated if it's tracked and allocated;
417 			 * and where we'd update the schedule tree...
418 			 */
419 			kfree(qh);
420 			qh = NULL;
421 			break;
422 		}
423 	}
424 
425 	if (qh != NULL && qh->is_ready) {
426 		dev_dbg(musb->controller, "... next ep%d %cX urb %p\n",
427 		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
428 		musb_start_urb(musb, is_in, qh);
429 	}
430 }
431 
432 static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
433 {
434 	/* we don't want fifo to fill itself again;
435 	 * ignore dma (various models),
436 	 * leave toggle alone (may not have been saved yet)
437 	 */
438 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
439 	csr &= ~(MUSB_RXCSR_H_REQPKT
440 		| MUSB_RXCSR_H_AUTOREQ
441 		| MUSB_RXCSR_AUTOCLEAR);
442 
443 	/* write 2x to allow double buffering */
444 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
445 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
446 
447 	/* flush writebuffer */
448 	return musb_readw(hw_ep->regs, MUSB_RXCSR);
449 }
450 
451 /*
452  * PIO RX for a packet (or part of it).
453  */
454 static bool
455 musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
456 {
457 	u16			rx_count;
458 	u8			*buf;
459 	u16			csr;
460 	bool			done = false;
461 	u32			length;
462 	int			do_flush = 0;
463 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
464 	void __iomem		*epio = hw_ep->regs;
465 	struct musb_qh		*qh = hw_ep->in_qh;
466 	int			pipe = urb->pipe;
467 	void			*buffer = urb->transfer_buffer;
468 
469 	/* musb_ep_select(mbase, epnum); */
470 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
471 	dev_dbg(musb->controller, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
472 			urb->transfer_buffer, qh->offset,
473 			urb->transfer_buffer_length);
474 
475 	/* unload FIFO */
476 	if (usb_pipeisoc(pipe)) {
477 		int					status = 0;
478 		struct usb_iso_packet_descriptor	*d;
479 
480 		if (iso_err) {
481 			status = -EILSEQ;
482 			urb->error_count++;
483 		}
484 
485 		d = urb->iso_frame_desc + qh->iso_idx;
486 		buf = buffer + d->offset;
487 		length = d->length;
488 		if (rx_count > length) {
489 			if (status == 0) {
490 				status = -EOVERFLOW;
491 				urb->error_count++;
492 			}
493 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
494 			do_flush = 1;
495 		} else
496 			length = rx_count;
497 		urb->actual_length += length;
498 		d->actual_length = length;
499 
500 		d->status = status;
501 
502 		/* see if we are done */
503 		done = (++qh->iso_idx >= urb->number_of_packets);
504 	} else {
505 		/* non-isoch */
506 		buf = buffer + qh->offset;
507 		length = urb->transfer_buffer_length - qh->offset;
508 		if (rx_count > length) {
509 			if (urb->status == -EINPROGRESS)
510 				urb->status = -EOVERFLOW;
511 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
512 			do_flush = 1;
513 		} else
514 			length = rx_count;
515 		urb->actual_length += length;
516 		qh->offset += length;
517 
518 		/* see if we are done */
519 		done = (urb->actual_length == urb->transfer_buffer_length)
520 			|| (rx_count < qh->maxpacket)
521 			|| (urb->status != -EINPROGRESS);
522 		if (done
523 				&& (urb->status == -EINPROGRESS)
524 				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
525 				&& (urb->actual_length
526 					< urb->transfer_buffer_length))
527 			urb->status = -EREMOTEIO;
528 	}
529 
530 	musb_read_fifo(hw_ep, length, buf);
531 
532 	csr = musb_readw(epio, MUSB_RXCSR);
533 	csr |= MUSB_RXCSR_H_WZC_BITS;
534 	if (unlikely(do_flush))
535 		musb_h_flush_rxfifo(hw_ep, csr);
536 	else {
537 		/* REVISIT this assumes AUTOCLEAR is never set */
538 		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
539 		if (!done)
540 			csr |= MUSB_RXCSR_H_REQPKT;
541 		musb_writew(epio, MUSB_RXCSR, csr);
542 	}
543 
544 	return done;
545 }
546 
547 /* we don't always need to reinit a given side of an endpoint...
548  * when we do, use tx/rx reinit routine and then construct a new CSR
549  * to address data toggle, NYET, and DMA or PIO.
550  *
551  * it's possible that driver bugs (especially for DMA) or aborting a
552  * transfer might have left the endpoint busier than it should be.
553  * the busy/not-empty tests are basically paranoia.
554  */
555 static void
556 musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
557 {
558 	u16	csr;
559 
560 	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
561 	 * That always uses tx_reinit since ep0 repurposes TX register
562 	 * offsets; the initial SETUP packet is also a kind of OUT.
563 	 */
564 
565 	/* if programmed for Tx, put it in RX mode */
566 	if (ep->is_shared_fifo) {
567 		csr = musb_readw(ep->regs, MUSB_TXCSR);
568 		if (csr & MUSB_TXCSR_MODE) {
569 			musb_h_tx_flush_fifo(ep);
570 			csr = musb_readw(ep->regs, MUSB_TXCSR);
571 			musb_writew(ep->regs, MUSB_TXCSR,
572 				    csr | MUSB_TXCSR_FRCDATATOG);
573 		}
574 
575 		/*
576 		 * Clear the MODE bit (and everything else) to enable Rx.
577 		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
578 		 */
579 		if (csr & MUSB_TXCSR_DMAMODE)
580 			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
581 		musb_writew(ep->regs, MUSB_TXCSR, 0);
582 
583 	/* scrub all previous state, clearing toggle */
584 	} else {
585 		csr = musb_readw(ep->regs, MUSB_RXCSR);
586 		if (csr & MUSB_RXCSR_RXPKTRDY)
587 			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
588 				musb_readw(ep->regs, MUSB_RXCOUNT));
589 
590 		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
591 	}
592 
593 	/* target addr and (for multipoint) hub addr/port */
594 	if (musb->is_multipoint) {
595 		musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
596 		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
597 		musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
598 
599 	} else
600 		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
601 
602 	/* protocol/endpoint, interval/NAKlimit, i/o size */
603 	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
604 	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
605 	/* NOTE: bulk combining rewrites high bits of maxpacket */
606 	/* Set RXMAXP with the FIFO size of the endpoint
607 	 * to disable double buffer mode.
608 	 */
609 	if (musb->double_buffer_not_ok)
610 		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
611 	else
612 		musb_writew(ep->regs, MUSB_RXMAXP,
613 				qh->maxpacket | ((qh->hb_mult - 1) << 11));
614 
615 	ep->rx_reinit = 0;
616 }
617 
618 static bool musb_tx_dma_program(struct dma_controller *dma,
619 		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
620 		struct urb *urb, u32 offset, u32 length)
621 {
622 	struct dma_channel	*channel = hw_ep->tx_channel;
623 	void __iomem		*epio = hw_ep->regs;
624 	u16			pkt_size = qh->maxpacket;
625 	u16			csr;
626 	u8			mode;
627 
628 #ifdef	CONFIG_USB_INVENTRA_DMA
629 	if (length > channel->max_len)
630 		length = channel->max_len;
631 
632 	csr = musb_readw(epio, MUSB_TXCSR);
633 	if (length > pkt_size) {
634 		mode = 1;
635 		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
636 		/* autoset shouldn't be set in high bandwidth */
637 		/*
638 		 * Enable Autoset according to table
639 		 * below
640 		 * bulk_split hb_mult	Autoset_Enable
641 		 *	0	1	Yes(Normal)
642 		 *	0	>1	No(High BW ISO)
643 		 *	1	1	Yes(HS bulk)
644 		 *	1	>1	Yes(FS bulk)
645 		 */
646 		if (qh->hb_mult == 1 || (qh->hb_mult > 1 &&
647 					can_bulk_split(hw_ep->musb, qh->type)))
648 			csr |= MUSB_TXCSR_AUTOSET;
649 	} else {
650 		mode = 0;
651 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
652 		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
653 	}
654 	channel->desired_mode = mode;
655 	musb_writew(epio, MUSB_TXCSR, csr);
656 #else
657 	if (!is_cppi_enabled() && !tusb_dma_omap())
658 		return false;
659 
660 	channel->actual_len = 0;
661 
662 	/*
663 	 * TX uses "RNDIS" mode automatically but needs help
664 	 * to identify the zero-length-final-packet case.
665 	 */
666 	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
667 #endif
668 
669 	qh->segsize = length;
670 
671 	/*
672 	 * Ensure the data reaches to main memory before starting
673 	 * DMA transfer
674 	 */
675 	wmb();
676 
677 	if (!dma->channel_program(channel, pkt_size, mode,
678 			urb->transfer_dma + offset, length)) {
679 		dma->channel_release(channel);
680 		hw_ep->tx_channel = NULL;
681 
682 		csr = musb_readw(epio, MUSB_TXCSR);
683 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
684 		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
685 		return false;
686 	}
687 	return true;
688 }
689 
690 /*
691  * Program an HDRC endpoint as per the given URB
692  * Context: irqs blocked, controller lock held
693  */
694 static void musb_ep_program(struct musb *musb, u8 epnum,
695 			struct urb *urb, int is_out,
696 			u8 *buf, u32 offset, u32 len)
697 {
698 	struct dma_controller	*dma_controller;
699 	struct dma_channel	*dma_channel;
700 	u8			dma_ok;
701 	void __iomem		*mbase = musb->mregs;
702 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
703 	void __iomem		*epio = hw_ep->regs;
704 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
705 	u16			packet_sz = qh->maxpacket;
706 	u8			use_dma = 1;
707 	u16			csr;
708 
709 	dev_dbg(musb->controller, "%s hw%d urb %p spd%d dev%d ep%d%s "
710 				"h_addr%02x h_port%02x bytes %d\n",
711 			is_out ? "-->" : "<--",
712 			epnum, urb, urb->dev->speed,
713 			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
714 			qh->h_addr_reg, qh->h_port_reg,
715 			len);
716 
717 	musb_ep_select(mbase, epnum);
718 
719 	if (is_out && !len) {
720 		use_dma = 0;
721 		csr = musb_readw(epio, MUSB_TXCSR);
722 		csr &= ~MUSB_TXCSR_DMAENAB;
723 		musb_writew(epio, MUSB_TXCSR, csr);
724 		hw_ep->tx_channel = NULL;
725 	}
726 
727 	/* candidate for DMA? */
728 	dma_controller = musb->dma_controller;
729 	if (use_dma && is_dma_capable() && epnum && dma_controller) {
730 		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
731 		if (!dma_channel) {
732 			dma_channel = dma_controller->channel_alloc(
733 					dma_controller, hw_ep, is_out);
734 			if (is_out)
735 				hw_ep->tx_channel = dma_channel;
736 			else
737 				hw_ep->rx_channel = dma_channel;
738 		}
739 	} else
740 		dma_channel = NULL;
741 
742 	/* make sure we clear DMAEnab, autoSet bits from previous run */
743 
744 	/* OUT/transmit/EP0 or IN/receive? */
745 	if (is_out) {
746 		u16	csr;
747 		u16	int_txe;
748 		u16	load_count;
749 
750 		csr = musb_readw(epio, MUSB_TXCSR);
751 
752 		/* disable interrupt in case we flush */
753 		int_txe = musb->intrtxe;
754 		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
755 
756 		/* general endpoint setup */
757 		if (epnum) {
758 			/* flush all old state, set default */
759 			/*
760 			 * We could be flushing valid
761 			 * packets in double buffering
762 			 * case
763 			 */
764 			if (!hw_ep->tx_double_buffered)
765 				musb_h_tx_flush_fifo(hw_ep);
766 
767 			/*
768 			 * We must not clear the DMAMODE bit before or in
769 			 * the same cycle with the DMAENAB bit, so we clear
770 			 * the latter first...
771 			 */
772 			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
773 					| MUSB_TXCSR_AUTOSET
774 					| MUSB_TXCSR_DMAENAB
775 					| MUSB_TXCSR_FRCDATATOG
776 					| MUSB_TXCSR_H_RXSTALL
777 					| MUSB_TXCSR_H_ERROR
778 					| MUSB_TXCSR_TXPKTRDY
779 					);
780 			csr |= MUSB_TXCSR_MODE;
781 
782 			if (!hw_ep->tx_double_buffered) {
783 				if (usb_gettoggle(urb->dev, qh->epnum, 1))
784 					csr |= MUSB_TXCSR_H_WR_DATATOGGLE
785 						| MUSB_TXCSR_H_DATATOGGLE;
786 				else
787 					csr |= MUSB_TXCSR_CLRDATATOG;
788 			}
789 
790 			musb_writew(epio, MUSB_TXCSR, csr);
791 			/* REVISIT may need to clear FLUSHFIFO ... */
792 			csr &= ~MUSB_TXCSR_DMAMODE;
793 			musb_writew(epio, MUSB_TXCSR, csr);
794 			csr = musb_readw(epio, MUSB_TXCSR);
795 		} else {
796 			/* endpoint 0: just flush */
797 			musb_h_ep0_flush_fifo(hw_ep);
798 		}
799 
800 		/* target addr and (for multipoint) hub addr/port */
801 		if (musb->is_multipoint) {
802 			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
803 			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
804 			musb_write_txhubport(mbase, epnum, qh->h_port_reg);
805 /* FIXME if !epnum, do the same for RX ... */
806 		} else
807 			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
808 
809 		/* protocol/endpoint/interval/NAKlimit */
810 		if (epnum) {
811 			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
812 			if (musb->double_buffer_not_ok) {
813 				musb_writew(epio, MUSB_TXMAXP,
814 						hw_ep->max_packet_sz_tx);
815 			} else if (can_bulk_split(musb, qh->type)) {
816 				qh->hb_mult = hw_ep->max_packet_sz_tx
817 						/ packet_sz;
818 				musb_writew(epio, MUSB_TXMAXP, packet_sz
819 					| ((qh->hb_mult) - 1) << 11);
820 			} else {
821 				musb_writew(epio, MUSB_TXMAXP,
822 						qh->maxpacket |
823 						((qh->hb_mult - 1) << 11));
824 			}
825 			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
826 		} else {
827 			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
828 			if (musb->is_multipoint)
829 				musb_writeb(epio, MUSB_TYPE0,
830 						qh->type_reg);
831 		}
832 
833 		if (can_bulk_split(musb, qh->type))
834 			load_count = min((u32) hw_ep->max_packet_sz_tx,
835 						len);
836 		else
837 			load_count = min((u32) packet_sz, len);
838 
839 		if (dma_channel && musb_tx_dma_program(dma_controller,
840 					hw_ep, qh, urb, offset, len))
841 			load_count = 0;
842 
843 		if (load_count) {
844 			/* PIO to load FIFO */
845 			qh->segsize = load_count;
846 			if (!buf) {
847 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
848 						SG_MITER_ATOMIC
849 						| SG_MITER_FROM_SG);
850 				if (!sg_miter_next(&qh->sg_miter)) {
851 					dev_err(musb->controller,
852 							"error: sg"
853 							"list empty\n");
854 					sg_miter_stop(&qh->sg_miter);
855 					goto finish;
856 				}
857 				buf = qh->sg_miter.addr + urb->sg->offset +
858 					urb->actual_length;
859 				load_count = min_t(u32, load_count,
860 						qh->sg_miter.length);
861 				musb_write_fifo(hw_ep, load_count, buf);
862 				qh->sg_miter.consumed = load_count;
863 				sg_miter_stop(&qh->sg_miter);
864 			} else
865 				musb_write_fifo(hw_ep, load_count, buf);
866 		}
867 finish:
868 		/* re-enable interrupt */
869 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
870 
871 	/* IN/receive */
872 	} else {
873 		u16	csr;
874 
875 		if (hw_ep->rx_reinit) {
876 			musb_rx_reinit(musb, qh, hw_ep);
877 
878 			/* init new state: toggle and NYET, maybe DMA later */
879 			if (usb_gettoggle(urb->dev, qh->epnum, 0))
880 				csr = MUSB_RXCSR_H_WR_DATATOGGLE
881 					| MUSB_RXCSR_H_DATATOGGLE;
882 			else
883 				csr = 0;
884 			if (qh->type == USB_ENDPOINT_XFER_INT)
885 				csr |= MUSB_RXCSR_DISNYET;
886 
887 		} else {
888 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
889 
890 			if (csr & (MUSB_RXCSR_RXPKTRDY
891 					| MUSB_RXCSR_DMAENAB
892 					| MUSB_RXCSR_H_REQPKT))
893 				ERR("broken !rx_reinit, ep%d csr %04x\n",
894 						hw_ep->epnum, csr);
895 
896 			/* scrub any stale state, leaving toggle alone */
897 			csr &= MUSB_RXCSR_DISNYET;
898 		}
899 
900 		/* kick things off */
901 
902 		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
903 			/* Candidate for DMA */
904 			dma_channel->actual_len = 0L;
905 			qh->segsize = len;
906 
907 			/* AUTOREQ is in a DMA register */
908 			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
909 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
910 
911 			/*
912 			 * Unless caller treats short RX transfers as
913 			 * errors, we dare not queue multiple transfers.
914 			 */
915 			dma_ok = dma_controller->channel_program(dma_channel,
916 					packet_sz, !(urb->transfer_flags &
917 						     URB_SHORT_NOT_OK),
918 					urb->transfer_dma + offset,
919 					qh->segsize);
920 			if (!dma_ok) {
921 				dma_controller->channel_release(dma_channel);
922 				hw_ep->rx_channel = dma_channel = NULL;
923 			} else
924 				csr |= MUSB_RXCSR_DMAENAB;
925 		}
926 
927 		csr |= MUSB_RXCSR_H_REQPKT;
928 		dev_dbg(musb->controller, "RXCSR%d := %04x\n", epnum, csr);
929 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
930 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
931 	}
932 }
933 
934 /* Schedule next QH from musb->in_bulk/out_bulk and move the current qh to
935  * the end; avoids starvation for other endpoints.
936  */
937 static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep,
938 	int is_in)
939 {
940 	struct dma_channel	*dma;
941 	struct urb		*urb;
942 	void __iomem		*mbase = musb->mregs;
943 	void __iomem		*epio = ep->regs;
944 	struct musb_qh		*cur_qh, *next_qh;
945 	u16			rx_csr, tx_csr;
946 
947 	musb_ep_select(mbase, ep->epnum);
948 	if (is_in) {
949 		dma = is_dma_capable() ? ep->rx_channel : NULL;
950 
951 		/* clear nak timeout bit */
952 		rx_csr = musb_readw(epio, MUSB_RXCSR);
953 		rx_csr |= MUSB_RXCSR_H_WZC_BITS;
954 		rx_csr &= ~MUSB_RXCSR_DATAERROR;
955 		musb_writew(epio, MUSB_RXCSR, rx_csr);
956 
957 		cur_qh = first_qh(&musb->in_bulk);
958 	} else {
959 		dma = is_dma_capable() ? ep->tx_channel : NULL;
960 
961 		/* clear nak timeout bit */
962 		tx_csr = musb_readw(epio, MUSB_TXCSR);
963 		tx_csr |= MUSB_TXCSR_H_WZC_BITS;
964 		tx_csr &= ~MUSB_TXCSR_H_NAKTIMEOUT;
965 		musb_writew(epio, MUSB_TXCSR, tx_csr);
966 
967 		cur_qh = first_qh(&musb->out_bulk);
968 	}
969 	if (cur_qh) {
970 		urb = next_urb(cur_qh);
971 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
972 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
973 			musb->dma_controller->channel_abort(dma);
974 			urb->actual_length += dma->actual_len;
975 			dma->actual_len = 0L;
976 		}
977 		musb_save_toggle(cur_qh, is_in, urb);
978 
979 		if (is_in) {
980 			/* move cur_qh to end of queue */
981 			list_move_tail(&cur_qh->ring, &musb->in_bulk);
982 
983 			/* get the next qh from musb->in_bulk */
984 			next_qh = first_qh(&musb->in_bulk);
985 
986 			/* set rx_reinit and schedule the next qh */
987 			ep->rx_reinit = 1;
988 		} else {
989 			/* move cur_qh to end of queue */
990 			list_move_tail(&cur_qh->ring, &musb->out_bulk);
991 
992 			/* get the next qh from musb->out_bulk */
993 			next_qh = first_qh(&musb->out_bulk);
994 
995 			/* set tx_reinit and schedule the next qh */
996 			ep->tx_reinit = 1;
997 		}
998 		musb_start_urb(musb, is_in, next_qh);
999 	}
1000 }
1001 
1002 /*
1003  * Service the default endpoint (ep0) as host.
1004  * Return true until it's time to start the status stage.
1005  */
1006 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
1007 {
1008 	bool			 more = false;
1009 	u8			*fifo_dest = NULL;
1010 	u16			fifo_count = 0;
1011 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1012 	struct musb_qh		*qh = hw_ep->in_qh;
1013 	struct usb_ctrlrequest	*request;
1014 
1015 	switch (musb->ep0_stage) {
1016 	case MUSB_EP0_IN:
1017 		fifo_dest = urb->transfer_buffer + urb->actual_length;
1018 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
1019 				   urb->actual_length);
1020 		if (fifo_count < len)
1021 			urb->status = -EOVERFLOW;
1022 
1023 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
1024 
1025 		urb->actual_length += fifo_count;
1026 		if (len < qh->maxpacket) {
1027 			/* always terminate on short read; it's
1028 			 * rarely reported as an error.
1029 			 */
1030 		} else if (urb->actual_length <
1031 				urb->transfer_buffer_length)
1032 			more = true;
1033 		break;
1034 	case MUSB_EP0_START:
1035 		request = (struct usb_ctrlrequest *) urb->setup_packet;
1036 
1037 		if (!request->wLength) {
1038 			dev_dbg(musb->controller, "start no-DATA\n");
1039 			break;
1040 		} else if (request->bRequestType & USB_DIR_IN) {
1041 			dev_dbg(musb->controller, "start IN-DATA\n");
1042 			musb->ep0_stage = MUSB_EP0_IN;
1043 			more = true;
1044 			break;
1045 		} else {
1046 			dev_dbg(musb->controller, "start OUT-DATA\n");
1047 			musb->ep0_stage = MUSB_EP0_OUT;
1048 			more = true;
1049 		}
1050 		/* FALLTHROUGH */
1051 	case MUSB_EP0_OUT:
1052 		fifo_count = min_t(size_t, qh->maxpacket,
1053 				   urb->transfer_buffer_length -
1054 				   urb->actual_length);
1055 		if (fifo_count) {
1056 			fifo_dest = (u8 *) (urb->transfer_buffer
1057 					+ urb->actual_length);
1058 			dev_dbg(musb->controller, "Sending %d byte%s to ep0 fifo %p\n",
1059 					fifo_count,
1060 					(fifo_count == 1) ? "" : "s",
1061 					fifo_dest);
1062 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
1063 
1064 			urb->actual_length += fifo_count;
1065 			more = true;
1066 		}
1067 		break;
1068 	default:
1069 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
1070 		break;
1071 	}
1072 
1073 	return more;
1074 }
1075 
1076 /*
1077  * Handle default endpoint interrupt as host. Only called in IRQ time
1078  * from musb_interrupt().
1079  *
1080  * called with controller irqlocked
1081  */
1082 irqreturn_t musb_h_ep0_irq(struct musb *musb)
1083 {
1084 	struct urb		*urb;
1085 	u16			csr, len;
1086 	int			status = 0;
1087 	void __iomem		*mbase = musb->mregs;
1088 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1089 	void __iomem		*epio = hw_ep->regs;
1090 	struct musb_qh		*qh = hw_ep->in_qh;
1091 	bool			complete = false;
1092 	irqreturn_t		retval = IRQ_NONE;
1093 
1094 	/* ep0 only has one queue, "in" */
1095 	urb = next_urb(qh);
1096 
1097 	musb_ep_select(mbase, 0);
1098 	csr = musb_readw(epio, MUSB_CSR0);
1099 	len = (csr & MUSB_CSR0_RXPKTRDY)
1100 			? musb_readb(epio, MUSB_COUNT0)
1101 			: 0;
1102 
1103 	dev_dbg(musb->controller, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
1104 		csr, qh, len, urb, musb->ep0_stage);
1105 
1106 	/* if we just did status stage, we are done */
1107 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
1108 		retval = IRQ_HANDLED;
1109 		complete = true;
1110 	}
1111 
1112 	/* prepare status */
1113 	if (csr & MUSB_CSR0_H_RXSTALL) {
1114 		dev_dbg(musb->controller, "STALLING ENDPOINT\n");
1115 		status = -EPIPE;
1116 
1117 	} else if (csr & MUSB_CSR0_H_ERROR) {
1118 		dev_dbg(musb->controller, "no response, csr0 %04x\n", csr);
1119 		status = -EPROTO;
1120 
1121 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1122 		dev_dbg(musb->controller, "control NAK timeout\n");
1123 
1124 		/* NOTE:  this code path would be a good place to PAUSE a
1125 		 * control transfer, if another one is queued, so that
1126 		 * ep0 is more likely to stay busy.  That's already done
1127 		 * for bulk RX transfers.
1128 		 *
1129 		 * if (qh->ring.next != &musb->control), then
1130 		 * we have a candidate... NAKing is *NOT* an error
1131 		 */
1132 		musb_writew(epio, MUSB_CSR0, 0);
1133 		retval = IRQ_HANDLED;
1134 	}
1135 
1136 	if (status) {
1137 		dev_dbg(musb->controller, "aborting\n");
1138 		retval = IRQ_HANDLED;
1139 		if (urb)
1140 			urb->status = status;
1141 		complete = true;
1142 
1143 		/* use the proper sequence to abort the transfer */
1144 		if (csr & MUSB_CSR0_H_REQPKT) {
1145 			csr &= ~MUSB_CSR0_H_REQPKT;
1146 			musb_writew(epio, MUSB_CSR0, csr);
1147 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1148 			musb_writew(epio, MUSB_CSR0, csr);
1149 		} else {
1150 			musb_h_ep0_flush_fifo(hw_ep);
1151 		}
1152 
1153 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1154 
1155 		/* clear it */
1156 		musb_writew(epio, MUSB_CSR0, 0);
1157 	}
1158 
1159 	if (unlikely(!urb)) {
1160 		/* stop endpoint since we have no place for its data, this
1161 		 * SHOULD NEVER HAPPEN! */
1162 		ERR("no URB for end 0\n");
1163 
1164 		musb_h_ep0_flush_fifo(hw_ep);
1165 		goto done;
1166 	}
1167 
1168 	if (!complete) {
1169 		/* call common logic and prepare response */
1170 		if (musb_h_ep0_continue(musb, len, urb)) {
1171 			/* more packets required */
1172 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1173 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1174 		} else {
1175 			/* data transfer complete; perform status phase */
1176 			if (usb_pipeout(urb->pipe)
1177 					|| !urb->transfer_buffer_length)
1178 				csr = MUSB_CSR0_H_STATUSPKT
1179 					| MUSB_CSR0_H_REQPKT;
1180 			else
1181 				csr = MUSB_CSR0_H_STATUSPKT
1182 					| MUSB_CSR0_TXPKTRDY;
1183 
1184 			/* flag status stage */
1185 			musb->ep0_stage = MUSB_EP0_STATUS;
1186 
1187 			dev_dbg(musb->controller, "ep0 STATUS, csr %04x\n", csr);
1188 
1189 		}
1190 		musb_writew(epio, MUSB_CSR0, csr);
1191 		retval = IRQ_HANDLED;
1192 	} else
1193 		musb->ep0_stage = MUSB_EP0_IDLE;
1194 
1195 	/* call completion handler if done */
1196 	if (complete)
1197 		musb_advance_schedule(musb, urb, hw_ep, 1);
1198 done:
1199 	return retval;
1200 }
1201 
1202 
1203 #ifdef CONFIG_USB_INVENTRA_DMA
1204 
1205 /* Host side TX (OUT) using Mentor DMA works as follows:
1206 	submit_urb ->
1207 		- if queue was empty, Program Endpoint
1208 		- ... which starts DMA to fifo in mode 1 or 0
1209 
1210 	DMA Isr (transfer complete) -> TxAvail()
1211 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1212 					only in musb_cleanup_urb)
1213 		- TxPktRdy has to be set in mode 0 or for
1214 			short packets in mode 1.
1215 */
1216 
1217 #endif
1218 
1219 /* Service a Tx-Available or dma completion irq for the endpoint */
1220 void musb_host_tx(struct musb *musb, u8 epnum)
1221 {
1222 	int			pipe;
1223 	bool			done = false;
1224 	u16			tx_csr;
1225 	size_t			length = 0;
1226 	size_t			offset = 0;
1227 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1228 	void __iomem		*epio = hw_ep->regs;
1229 	struct musb_qh		*qh = hw_ep->out_qh;
1230 	struct urb		*urb = next_urb(qh);
1231 	u32			status = 0;
1232 	void __iomem		*mbase = musb->mregs;
1233 	struct dma_channel	*dma;
1234 	bool			transfer_pending = false;
1235 
1236 	musb_ep_select(mbase, epnum);
1237 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1238 
1239 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1240 	if (!urb) {
1241 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1242 		return;
1243 	}
1244 
1245 	pipe = urb->pipe;
1246 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1247 	dev_dbg(musb->controller, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
1248 			dma ? ", dma" : "");
1249 
1250 	/* check for errors */
1251 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1252 		/* dma was disabled, fifo flushed */
1253 		dev_dbg(musb->controller, "TX end %d stall\n", epnum);
1254 
1255 		/* stall; record URB status */
1256 		status = -EPIPE;
1257 
1258 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1259 		/* (NON-ISO) dma was disabled, fifo flushed */
1260 		dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum);
1261 
1262 		status = -ETIMEDOUT;
1263 
1264 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1265 		if (USB_ENDPOINT_XFER_BULK == qh->type && qh->mux == 1
1266 				&& !list_is_singular(&musb->out_bulk)) {
1267 			dev_dbg(musb->controller,
1268 				"NAK timeout on TX%d ep\n", epnum);
1269 			musb_bulk_nak_timeout(musb, hw_ep, 0);
1270 		} else {
1271 			dev_dbg(musb->controller,
1272 				"TX end=%d device not responding\n", epnum);
1273 			/* NOTE:  this code path would be a good place to PAUSE a
1274 			 * transfer, if there's some other (nonperiodic) tx urb
1275 			 * that could use this fifo.  (dma complicates it...)
1276 			 * That's already done for bulk RX transfers.
1277 			 *
1278 			 * if (bulk && qh->ring.next != &musb->out_bulk), then
1279 			 * we have a candidate... NAKing is *NOT* an error
1280 			 */
1281 			musb_ep_select(mbase, epnum);
1282 			musb_writew(epio, MUSB_TXCSR,
1283 					MUSB_TXCSR_H_WZC_BITS
1284 					| MUSB_TXCSR_TXPKTRDY);
1285 		}
1286 			return;
1287 	}
1288 
1289 done:
1290 	if (status) {
1291 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1292 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1293 			(void) musb->dma_controller->channel_abort(dma);
1294 		}
1295 
1296 		/* do the proper sequence to abort the transfer in the
1297 		 * usb core; the dma engine should already be stopped.
1298 		 */
1299 		musb_h_tx_flush_fifo(hw_ep);
1300 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1301 				| MUSB_TXCSR_DMAENAB
1302 				| MUSB_TXCSR_H_ERROR
1303 				| MUSB_TXCSR_H_RXSTALL
1304 				| MUSB_TXCSR_H_NAKTIMEOUT
1305 				);
1306 
1307 		musb_ep_select(mbase, epnum);
1308 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1309 		/* REVISIT may need to clear FLUSHFIFO ... */
1310 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1311 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1312 
1313 		done = true;
1314 	}
1315 
1316 	/* second cppi case */
1317 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1318 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1319 		return;
1320 	}
1321 
1322 	if (is_dma_capable() && dma && !status) {
1323 		/*
1324 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1325 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1326 		 * we can consider this transfer completed, lest we trash
1327 		 * its last packet when writing the next URB's data.  So we
1328 		 * switch back to mode 0 to get that interrupt; we'll come
1329 		 * back here once it happens.
1330 		 */
1331 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1332 			/*
1333 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1334 			 * clear them in a safe order.  That should be OK
1335 			 * once TXPKTRDY has been set (and I've never seen
1336 			 * it being 0 at this moment -- DMA interrupt latency
1337 			 * is significant) but if it hasn't been then we have
1338 			 * no choice but to stop being polite and ignore the
1339 			 * programmer's guide... :-)
1340 			 *
1341 			 * Note that we must write TXCSR with TXPKTRDY cleared
1342 			 * in order not to re-trigger the packet send (this bit
1343 			 * can't be cleared by CPU), and there's another caveat:
1344 			 * TXPKTRDY may be set shortly and then cleared in the
1345 			 * double-buffered FIFO mode, so we do an extra TXCSR
1346 			 * read for debouncing...
1347 			 */
1348 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1349 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1350 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1351 					    MUSB_TXCSR_TXPKTRDY);
1352 				musb_writew(epio, MUSB_TXCSR,
1353 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1354 			}
1355 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1356 				    MUSB_TXCSR_TXPKTRDY);
1357 			musb_writew(epio, MUSB_TXCSR,
1358 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1359 
1360 			/*
1361 			 * There is no guarantee that we'll get an interrupt
1362 			 * after clearing DMAMODE as we might have done this
1363 			 * too late (after TXPKTRDY was cleared by controller).
1364 			 * Re-read TXCSR as we have spoiled its previous value.
1365 			 */
1366 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1367 		}
1368 
1369 		/*
1370 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1371 		 * In any case, we must check the FIFO status here and bail out
1372 		 * only if the FIFO still has data -- that should prevent the
1373 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1374 		 * FIFO mode too...
1375 		 */
1376 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1377 			dev_dbg(musb->controller, "DMA complete but packet still in FIFO, "
1378 			    "CSR %04x\n", tx_csr);
1379 			return;
1380 		}
1381 	}
1382 
1383 	if (!status || dma || usb_pipeisoc(pipe)) {
1384 		if (dma)
1385 			length = dma->actual_len;
1386 		else
1387 			length = qh->segsize;
1388 		qh->offset += length;
1389 
1390 		if (usb_pipeisoc(pipe)) {
1391 			struct usb_iso_packet_descriptor	*d;
1392 
1393 			d = urb->iso_frame_desc + qh->iso_idx;
1394 			d->actual_length = length;
1395 			d->status = status;
1396 			if (++qh->iso_idx >= urb->number_of_packets) {
1397 				done = true;
1398 			} else {
1399 				d++;
1400 				offset = d->offset;
1401 				length = d->length;
1402 			}
1403 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1404 			done = true;
1405 		} else {
1406 			/* see if we need to send more data, or ZLP */
1407 			if (qh->segsize < qh->maxpacket)
1408 				done = true;
1409 			else if (qh->offset == urb->transfer_buffer_length
1410 					&& !(urb->transfer_flags
1411 						& URB_ZERO_PACKET))
1412 				done = true;
1413 			if (!done) {
1414 				offset = qh->offset;
1415 				length = urb->transfer_buffer_length - offset;
1416 				transfer_pending = true;
1417 			}
1418 		}
1419 	}
1420 
1421 	/* urb->status != -EINPROGRESS means request has been faulted,
1422 	 * so we must abort this transfer after cleanup
1423 	 */
1424 	if (urb->status != -EINPROGRESS) {
1425 		done = true;
1426 		if (status == 0)
1427 			status = urb->status;
1428 	}
1429 
1430 	if (done) {
1431 		/* set status */
1432 		urb->status = status;
1433 		urb->actual_length = qh->offset;
1434 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1435 		return;
1436 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1437 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1438 				offset, length)) {
1439 			if (is_cppi_enabled() || tusb_dma_omap())
1440 				musb_h_tx_dma_start(hw_ep);
1441 			return;
1442 		}
1443 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1444 		dev_dbg(musb->controller, "not complete, but DMA enabled?\n");
1445 		return;
1446 	}
1447 
1448 	/*
1449 	 * PIO: start next packet in this URB.
1450 	 *
1451 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1452 	 * (and presumably, FIFO is not half-full) we should write *two*
1453 	 * packets before updating TXCSR; other docs disagree...
1454 	 */
1455 	if (length > qh->maxpacket)
1456 		length = qh->maxpacket;
1457 	/* Unmap the buffer so that CPU can use it */
1458 	usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1459 
1460 	/*
1461 	 * We need to map sg if the transfer_buffer is
1462 	 * NULL.
1463 	 */
1464 	if (!urb->transfer_buffer)
1465 		qh->use_sg = true;
1466 
1467 	if (qh->use_sg) {
1468 		/* sg_miter_start is already done in musb_ep_program */
1469 		if (!sg_miter_next(&qh->sg_miter)) {
1470 			dev_err(musb->controller, "error: sg list empty\n");
1471 			sg_miter_stop(&qh->sg_miter);
1472 			status = -EINVAL;
1473 			goto done;
1474 		}
1475 		urb->transfer_buffer = qh->sg_miter.addr;
1476 		length = min_t(u32, length, qh->sg_miter.length);
1477 		musb_write_fifo(hw_ep, length, urb->transfer_buffer);
1478 		qh->sg_miter.consumed = length;
1479 		sg_miter_stop(&qh->sg_miter);
1480 	} else {
1481 		musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1482 	}
1483 
1484 	qh->segsize = length;
1485 
1486 	if (qh->use_sg) {
1487 		if (offset + length >= urb->transfer_buffer_length)
1488 			qh->use_sg = false;
1489 	}
1490 
1491 	musb_ep_select(mbase, epnum);
1492 	musb_writew(epio, MUSB_TXCSR,
1493 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1494 }
1495 
1496 
1497 #ifdef CONFIG_USB_INVENTRA_DMA
1498 
1499 /* Host side RX (IN) using Mentor DMA works as follows:
1500 	submit_urb ->
1501 		- if queue was empty, ProgramEndpoint
1502 		- first IN token is sent out (by setting ReqPkt)
1503 	LinuxIsr -> RxReady()
1504 	/\	=> first packet is received
1505 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1506 	|		-> DMA Isr (transfer complete) -> RxReady()
1507 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1508 	|		    - if urb not complete, send next IN token (ReqPkt)
1509 	|			   |		else complete urb.
1510 	|			   |
1511 	---------------------------
1512  *
1513  * Nuances of mode 1:
1514  *	For short packets, no ack (+RxPktRdy) is sent automatically
1515  *	(even if AutoClear is ON)
1516  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1517  *	automatically => major problem, as collecting the next packet becomes
1518  *	difficult. Hence mode 1 is not used.
1519  *
1520  * REVISIT
1521  *	All we care about at this driver level is that
1522  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1523  *       (b) termination conditions are: short RX, or buffer full;
1524  *       (c) fault modes include
1525  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1526  *             (and that endpoint's dma queue stops immediately)
1527  *           - overflow (full, PLUS more bytes in the terminal packet)
1528  *
1529  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1530  *	thus be a great candidate for using mode 1 ... for all but the
1531  *	last packet of one URB's transfer.
1532  */
1533 
1534 #endif
1535 
1536 /*
1537  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1538  * and high-bandwidth IN transfer cases.
1539  */
1540 void musb_host_rx(struct musb *musb, u8 epnum)
1541 {
1542 	struct urb		*urb;
1543 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1544 	void __iomem		*epio = hw_ep->regs;
1545 	struct musb_qh		*qh = hw_ep->in_qh;
1546 	size_t			xfer_len;
1547 	void __iomem		*mbase = musb->mregs;
1548 	int			pipe;
1549 	u16			rx_csr, val;
1550 	bool			iso_err = false;
1551 	bool			done = false;
1552 	u32			status;
1553 	struct dma_channel	*dma;
1554 	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
1555 
1556 	musb_ep_select(mbase, epnum);
1557 
1558 	urb = next_urb(qh);
1559 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1560 	status = 0;
1561 	xfer_len = 0;
1562 
1563 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1564 	val = rx_csr;
1565 
1566 	if (unlikely(!urb)) {
1567 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1568 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1569 		 * with fifo full.  (Only with DMA??)
1570 		 */
1571 		dev_dbg(musb->controller, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
1572 			musb_readw(epio, MUSB_RXCOUNT));
1573 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1574 		return;
1575 	}
1576 
1577 	pipe = urb->pipe;
1578 
1579 	dev_dbg(musb->controller, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
1580 		epnum, rx_csr, urb->actual_length,
1581 		dma ? dma->actual_len : 0);
1582 
1583 	/* check for errors, concurrent stall & unlink is not really
1584 	 * handled yet! */
1585 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1586 		dev_dbg(musb->controller, "RX end %d STALL\n", epnum);
1587 
1588 		/* stall; record URB status */
1589 		status = -EPIPE;
1590 
1591 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1592 		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
1593 
1594 		status = -EPROTO;
1595 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1596 
1597 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1598 
1599 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1600 			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
1601 
1602 			/* NOTE: NAKing is *NOT* an error, so we want to
1603 			 * continue.  Except ... if there's a request for
1604 			 * another QH, use that instead of starving it.
1605 			 *
1606 			 * Devices like Ethernet and serial adapters keep
1607 			 * reads posted at all times, which will starve
1608 			 * other devices without this logic.
1609 			 */
1610 			if (usb_pipebulk(urb->pipe)
1611 					&& qh->mux == 1
1612 					&& !list_is_singular(&musb->in_bulk)) {
1613 				musb_bulk_nak_timeout(musb, hw_ep, 1);
1614 				return;
1615 			}
1616 			musb_ep_select(mbase, epnum);
1617 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1618 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1619 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1620 
1621 			goto finish;
1622 		} else {
1623 			dev_dbg(musb->controller, "RX end %d ISO data error\n", epnum);
1624 			/* packet error reported later */
1625 			iso_err = true;
1626 		}
1627 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1628 		dev_dbg(musb->controller, "end %d high bandwidth incomplete ISO packet RX\n",
1629 				epnum);
1630 		status = -EPROTO;
1631 	}
1632 
1633 	/* faults abort the transfer */
1634 	if (status) {
1635 		/* clean up dma and collect transfer count */
1636 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1637 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1638 			(void) musb->dma_controller->channel_abort(dma);
1639 			xfer_len = dma->actual_len;
1640 		}
1641 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1642 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1643 		done = true;
1644 		goto finish;
1645 	}
1646 
1647 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1648 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1649 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1650 		goto finish;
1651 	}
1652 
1653 	/* thorough shutdown for now ... given more precise fault handling
1654 	 * and better queueing support, we might keep a DMA pipeline going
1655 	 * while processing this irq for earlier completions.
1656 	 */
1657 
1658 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1659 
1660 #ifndef CONFIG_USB_INVENTRA_DMA
1661 	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
1662 		/* REVISIT this happened for a while on some short reads...
1663 		 * the cleanup still needs investigation... looks bad...
1664 		 * and also duplicates dma cleanup code above ... plus,
1665 		 * shouldn't this be the "half full" double buffer case?
1666 		 */
1667 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1668 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1669 			(void) musb->dma_controller->channel_abort(dma);
1670 			xfer_len = dma->actual_len;
1671 			done = true;
1672 		}
1673 
1674 		dev_dbg(musb->controller, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
1675 				xfer_len, dma ? ", dma" : "");
1676 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1677 
1678 		musb_ep_select(mbase, epnum);
1679 		musb_writew(epio, MUSB_RXCSR,
1680 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1681 	}
1682 #endif
1683 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1684 		xfer_len = dma->actual_len;
1685 
1686 		val &= ~(MUSB_RXCSR_DMAENAB
1687 			| MUSB_RXCSR_H_AUTOREQ
1688 			| MUSB_RXCSR_AUTOCLEAR
1689 			| MUSB_RXCSR_RXPKTRDY);
1690 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1691 
1692 #ifdef CONFIG_USB_INVENTRA_DMA
1693 		if (usb_pipeisoc(pipe)) {
1694 			struct usb_iso_packet_descriptor *d;
1695 
1696 			d = urb->iso_frame_desc + qh->iso_idx;
1697 			d->actual_length = xfer_len;
1698 
1699 			/* even if there was an error, we did the dma
1700 			 * for iso_frame_desc->length
1701 			 */
1702 			if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1703 				d->status = 0;
1704 
1705 			if (++qh->iso_idx >= urb->number_of_packets)
1706 				done = true;
1707 			else
1708 				done = false;
1709 
1710 		} else  {
1711 		/* done if urb buffer is full or short packet is recd */
1712 		done = (urb->actual_length + xfer_len >=
1713 				urb->transfer_buffer_length
1714 			|| dma->actual_len < qh->maxpacket);
1715 		}
1716 
1717 		/* send IN token for next packet, without AUTOREQ */
1718 		if (!done) {
1719 			val |= MUSB_RXCSR_H_REQPKT;
1720 			musb_writew(epio, MUSB_RXCSR,
1721 				MUSB_RXCSR_H_WZC_BITS | val);
1722 		}
1723 
1724 		dev_dbg(musb->controller, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
1725 			done ? "off" : "reset",
1726 			musb_readw(epio, MUSB_RXCSR),
1727 			musb_readw(epio, MUSB_RXCOUNT));
1728 #else
1729 		done = true;
1730 #endif
1731 	} else if (urb->status == -EINPROGRESS) {
1732 		/* if no errors, be sure a packet is ready for unloading */
1733 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1734 			status = -EPROTO;
1735 			ERR("Rx interrupt with no errors or packet!\n");
1736 
1737 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1738 
1739 /* SCRUB (RX) */
1740 			/* do the proper sequence to abort the transfer */
1741 			musb_ep_select(mbase, epnum);
1742 			val &= ~MUSB_RXCSR_H_REQPKT;
1743 			musb_writew(epio, MUSB_RXCSR, val);
1744 			goto finish;
1745 		}
1746 
1747 		/* we are expecting IN packets */
1748 #ifdef CONFIG_USB_INVENTRA_DMA
1749 		if (dma) {
1750 			struct dma_controller	*c;
1751 			u16			rx_count;
1752 			int			ret, length;
1753 			dma_addr_t		buf;
1754 
1755 			rx_count = musb_readw(epio, MUSB_RXCOUNT);
1756 
1757 			dev_dbg(musb->controller, "RX%d count %d, buffer 0x%x len %d/%d\n",
1758 					epnum, rx_count,
1759 					urb->transfer_dma
1760 						+ urb->actual_length,
1761 					qh->offset,
1762 					urb->transfer_buffer_length);
1763 
1764 			c = musb->dma_controller;
1765 
1766 			if (usb_pipeisoc(pipe)) {
1767 				int d_status = 0;
1768 				struct usb_iso_packet_descriptor *d;
1769 
1770 				d = urb->iso_frame_desc + qh->iso_idx;
1771 
1772 				if (iso_err) {
1773 					d_status = -EILSEQ;
1774 					urb->error_count++;
1775 				}
1776 				if (rx_count > d->length) {
1777 					if (d_status == 0) {
1778 						d_status = -EOVERFLOW;
1779 						urb->error_count++;
1780 					}
1781 					dev_dbg(musb->controller, "** OVERFLOW %d into %d\n",\
1782 					    rx_count, d->length);
1783 
1784 					length = d->length;
1785 				} else
1786 					length = rx_count;
1787 				d->status = d_status;
1788 				buf = urb->transfer_dma + d->offset;
1789 			} else {
1790 				length = rx_count;
1791 				buf = urb->transfer_dma +
1792 						urb->actual_length;
1793 			}
1794 
1795 			dma->desired_mode = 0;
1796 #ifdef USE_MODE1
1797 			/* because of the issue below, mode 1 will
1798 			 * only rarely behave with correct semantics.
1799 			 */
1800 			if ((urb->transfer_flags &
1801 						URB_SHORT_NOT_OK)
1802 				&& (urb->transfer_buffer_length -
1803 						urb->actual_length)
1804 					> qh->maxpacket)
1805 				dma->desired_mode = 1;
1806 			if (rx_count < hw_ep->max_packet_sz_rx) {
1807 				length = rx_count;
1808 				dma->desired_mode = 0;
1809 			} else {
1810 				length = urb->transfer_buffer_length;
1811 			}
1812 #endif
1813 
1814 /* Disadvantage of using mode 1:
1815  *	It's basically usable only for mass storage class; essentially all
1816  *	other protocols also terminate transfers on short packets.
1817  *
1818  * Details:
1819  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1820  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1821  *	to use the extra IN token to grab the last packet using mode 0, then
1822  *	the problem is that you cannot be sure when the device will send the
1823  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1824  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1825  *	transfer, while sometimes it is recd just a little late so that if you
1826  *	try to configure for mode 0 soon after the mode 1 transfer is
1827  *	completed, you will find rxcount 0. Okay, so you might think why not
1828  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1829  */
1830 
1831 			val = musb_readw(epio, MUSB_RXCSR);
1832 			val &= ~MUSB_RXCSR_H_REQPKT;
1833 
1834 			if (dma->desired_mode == 0)
1835 				val &= ~MUSB_RXCSR_H_AUTOREQ;
1836 			else
1837 				val |= MUSB_RXCSR_H_AUTOREQ;
1838 			val |= MUSB_RXCSR_DMAENAB;
1839 
1840 			/* autoclear shouldn't be set in high bandwidth */
1841 			if (qh->hb_mult == 1)
1842 				val |= MUSB_RXCSR_AUTOCLEAR;
1843 
1844 			musb_writew(epio, MUSB_RXCSR,
1845 				MUSB_RXCSR_H_WZC_BITS | val);
1846 
1847 			/* REVISIT if when actual_length != 0,
1848 			 * transfer_buffer_length needs to be
1849 			 * adjusted first...
1850 			 */
1851 			ret = c->channel_program(
1852 				dma, qh->maxpacket,
1853 				dma->desired_mode, buf, length);
1854 
1855 			if (!ret) {
1856 				c->channel_release(dma);
1857 				hw_ep->rx_channel = NULL;
1858 				dma = NULL;
1859 				val = musb_readw(epio, MUSB_RXCSR);
1860 				val &= ~(MUSB_RXCSR_DMAENAB
1861 					| MUSB_RXCSR_H_AUTOREQ
1862 					| MUSB_RXCSR_AUTOCLEAR);
1863 				musb_writew(epio, MUSB_RXCSR, val);
1864 			}
1865 		}
1866 #endif	/* Mentor DMA */
1867 
1868 		if (!dma) {
1869 			unsigned int received_len;
1870 
1871 			/* Unmap the buffer so that CPU can use it */
1872 			usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1873 
1874 			/*
1875 			 * We need to map sg if the transfer_buffer is
1876 			 * NULL.
1877 			 */
1878 			if (!urb->transfer_buffer) {
1879 				qh->use_sg = true;
1880 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
1881 						sg_flags);
1882 			}
1883 
1884 			if (qh->use_sg) {
1885 				if (!sg_miter_next(&qh->sg_miter)) {
1886 					dev_err(musb->controller, "error: sg list empty\n");
1887 					sg_miter_stop(&qh->sg_miter);
1888 					status = -EINVAL;
1889 					done = true;
1890 					goto finish;
1891 				}
1892 				urb->transfer_buffer = qh->sg_miter.addr;
1893 				received_len = urb->actual_length;
1894 				qh->offset = 0x0;
1895 				done = musb_host_packet_rx(musb, urb, epnum,
1896 						iso_err);
1897 				/* Calculate the number of bytes received */
1898 				received_len = urb->actual_length -
1899 					received_len;
1900 				qh->sg_miter.consumed = received_len;
1901 				sg_miter_stop(&qh->sg_miter);
1902 			} else {
1903 				done = musb_host_packet_rx(musb, urb,
1904 						epnum, iso_err);
1905 			}
1906 			dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
1907 		}
1908 	}
1909 
1910 finish:
1911 	urb->actual_length += xfer_len;
1912 	qh->offset += xfer_len;
1913 	if (done) {
1914 		if (qh->use_sg)
1915 			qh->use_sg = false;
1916 
1917 		if (urb->status == -EINPROGRESS)
1918 			urb->status = status;
1919 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1920 	}
1921 }
1922 
1923 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1924  * the software schedule associates multiple such nodes with a given
1925  * host side hardware endpoint + direction; scheduling may activate
1926  * that hardware endpoint.
1927  */
1928 static int musb_schedule(
1929 	struct musb		*musb,
1930 	struct musb_qh		*qh,
1931 	int			is_in)
1932 {
1933 	int			idle;
1934 	int			best_diff;
1935 	int			best_end, epnum;
1936 	struct musb_hw_ep	*hw_ep = NULL;
1937 	struct list_head	*head = NULL;
1938 	u8			toggle;
1939 	u8			txtype;
1940 	struct urb		*urb = next_urb(qh);
1941 
1942 	/* use fixed hardware for control and bulk */
1943 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1944 		head = &musb->control;
1945 		hw_ep = musb->control_ep;
1946 		goto success;
1947 	}
1948 
1949 	/* else, periodic transfers get muxed to other endpoints */
1950 
1951 	/*
1952 	 * We know this qh hasn't been scheduled, so all we need to do
1953 	 * is choose which hardware endpoint to put it on ...
1954 	 *
1955 	 * REVISIT what we really want here is a regular schedule tree
1956 	 * like e.g. OHCI uses.
1957 	 */
1958 	best_diff = 4096;
1959 	best_end = -1;
1960 
1961 	for (epnum = 1, hw_ep = musb->endpoints + 1;
1962 			epnum < musb->nr_endpoints;
1963 			epnum++, hw_ep++) {
1964 		int	diff;
1965 
1966 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
1967 			continue;
1968 
1969 		if (hw_ep == musb->bulk_ep)
1970 			continue;
1971 
1972 		if (is_in)
1973 			diff = hw_ep->max_packet_sz_rx;
1974 		else
1975 			diff = hw_ep->max_packet_sz_tx;
1976 		diff -= (qh->maxpacket * qh->hb_mult);
1977 
1978 		if (diff >= 0 && best_diff > diff) {
1979 
1980 			/*
1981 			 * Mentor controller has a bug in that if we schedule
1982 			 * a BULK Tx transfer on an endpoint that had earlier
1983 			 * handled ISOC then the BULK transfer has to start on
1984 			 * a zero toggle.  If the BULK transfer starts on a 1
1985 			 * toggle then this transfer will fail as the mentor
1986 			 * controller starts the Bulk transfer on a 0 toggle
1987 			 * irrespective of the programming of the toggle bits
1988 			 * in the TXCSR register.  Check for this condition
1989 			 * while allocating the EP for a Tx Bulk transfer.  If
1990 			 * so skip this EP.
1991 			 */
1992 			hw_ep = musb->endpoints + epnum;
1993 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
1994 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
1995 					>> 4) & 0x3;
1996 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
1997 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
1998 				continue;
1999 
2000 			best_diff = diff;
2001 			best_end = epnum;
2002 		}
2003 	}
2004 	/* use bulk reserved ep1 if no other ep is free */
2005 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
2006 		hw_ep = musb->bulk_ep;
2007 		if (is_in)
2008 			head = &musb->in_bulk;
2009 		else
2010 			head = &musb->out_bulk;
2011 
2012 		/* Enable bulk RX/TX NAK timeout scheme when bulk requests are
2013 		 * multiplexed.  This scheme doen't work in high speed to full
2014 		 * speed scenario as NAK interrupts are not coming from a
2015 		 * full speed device connected to a high speed device.
2016 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
2017 		 * 4 (8 frame or 8ms) for FS device.
2018 		 */
2019 		if (qh->dev)
2020 			qh->intv_reg =
2021 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
2022 		goto success;
2023 	} else if (best_end < 0) {
2024 		return -ENOSPC;
2025 	}
2026 
2027 	idle = 1;
2028 	qh->mux = 0;
2029 	hw_ep = musb->endpoints + best_end;
2030 	dev_dbg(musb->controller, "qh %p periodic slot %d\n", qh, best_end);
2031 success:
2032 	if (head) {
2033 		idle = list_empty(head);
2034 		list_add_tail(&qh->ring, head);
2035 		qh->mux = 1;
2036 	}
2037 	qh->hw_ep = hw_ep;
2038 	qh->hep->hcpriv = qh;
2039 	if (idle)
2040 		musb_start_urb(musb, is_in, qh);
2041 	return 0;
2042 }
2043 
2044 static int musb_urb_enqueue(
2045 	struct usb_hcd			*hcd,
2046 	struct urb			*urb,
2047 	gfp_t				mem_flags)
2048 {
2049 	unsigned long			flags;
2050 	struct musb			*musb = hcd_to_musb(hcd);
2051 	struct usb_host_endpoint	*hep = urb->ep;
2052 	struct musb_qh			*qh;
2053 	struct usb_endpoint_descriptor	*epd = &hep->desc;
2054 	int				ret;
2055 	unsigned			type_reg;
2056 	unsigned			interval;
2057 
2058 	/* host role must be active */
2059 	if (!is_host_active(musb) || !musb->is_active)
2060 		return -ENODEV;
2061 
2062 	spin_lock_irqsave(&musb->lock, flags);
2063 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
2064 	qh = ret ? NULL : hep->hcpriv;
2065 	if (qh)
2066 		urb->hcpriv = qh;
2067 	spin_unlock_irqrestore(&musb->lock, flags);
2068 
2069 	/* DMA mapping was already done, if needed, and this urb is on
2070 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
2071 	 * scheduled onto a live qh.
2072 	 *
2073 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
2074 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
2075 	 * except for the first urb queued after a config change.
2076 	 */
2077 	if (qh || ret)
2078 		return ret;
2079 
2080 	/* Allocate and initialize qh, minimizing the work done each time
2081 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
2082 	 *
2083 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
2084 	 * for bugs in other kernel code to break this driver...
2085 	 */
2086 	qh = kzalloc(sizeof *qh, mem_flags);
2087 	if (!qh) {
2088 		spin_lock_irqsave(&musb->lock, flags);
2089 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2090 		spin_unlock_irqrestore(&musb->lock, flags);
2091 		return -ENOMEM;
2092 	}
2093 
2094 	qh->hep = hep;
2095 	qh->dev = urb->dev;
2096 	INIT_LIST_HEAD(&qh->ring);
2097 	qh->is_ready = 1;
2098 
2099 	qh->maxpacket = usb_endpoint_maxp(epd);
2100 	qh->type = usb_endpoint_type(epd);
2101 
2102 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
2103 	 * Some musb cores don't support high bandwidth ISO transfers; and
2104 	 * we don't (yet!) support high bandwidth interrupt transfers.
2105 	 */
2106 	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
2107 	if (qh->hb_mult > 1) {
2108 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
2109 
2110 		if (ok)
2111 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
2112 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
2113 		if (!ok) {
2114 			ret = -EMSGSIZE;
2115 			goto done;
2116 		}
2117 		qh->maxpacket &= 0x7ff;
2118 	}
2119 
2120 	qh->epnum = usb_endpoint_num(epd);
2121 
2122 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
2123 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
2124 
2125 	/* precompute rxtype/txtype/type0 register */
2126 	type_reg = (qh->type << 4) | qh->epnum;
2127 	switch (urb->dev->speed) {
2128 	case USB_SPEED_LOW:
2129 		type_reg |= 0xc0;
2130 		break;
2131 	case USB_SPEED_FULL:
2132 		type_reg |= 0x80;
2133 		break;
2134 	default:
2135 		type_reg |= 0x40;
2136 	}
2137 	qh->type_reg = type_reg;
2138 
2139 	/* Precompute RXINTERVAL/TXINTERVAL register */
2140 	switch (qh->type) {
2141 	case USB_ENDPOINT_XFER_INT:
2142 		/*
2143 		 * Full/low speeds use the  linear encoding,
2144 		 * high speed uses the logarithmic encoding.
2145 		 */
2146 		if (urb->dev->speed <= USB_SPEED_FULL) {
2147 			interval = max_t(u8, epd->bInterval, 1);
2148 			break;
2149 		}
2150 		/* FALLTHROUGH */
2151 	case USB_ENDPOINT_XFER_ISOC:
2152 		/* ISO always uses logarithmic encoding */
2153 		interval = min_t(u8, epd->bInterval, 16);
2154 		break;
2155 	default:
2156 		/* REVISIT we actually want to use NAK limits, hinting to the
2157 		 * transfer scheduling logic to try some other qh, e.g. try
2158 		 * for 2 msec first:
2159 		 *
2160 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2161 		 *
2162 		 * The downside of disabling this is that transfer scheduling
2163 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2164 		 * peripheral could make that hurt.  That's perfectly normal
2165 		 * for reads from network or serial adapters ... so we have
2166 		 * partial NAKlimit support for bulk RX.
2167 		 *
2168 		 * The upside of disabling it is simpler transfer scheduling.
2169 		 */
2170 		interval = 0;
2171 	}
2172 	qh->intv_reg = interval;
2173 
2174 	/* precompute addressing for external hub/tt ports */
2175 	if (musb->is_multipoint) {
2176 		struct usb_device	*parent = urb->dev->parent;
2177 
2178 		if (parent != hcd->self.root_hub) {
2179 			qh->h_addr_reg = (u8) parent->devnum;
2180 
2181 			/* set up tt info if needed */
2182 			if (urb->dev->tt) {
2183 				qh->h_port_reg = (u8) urb->dev->ttport;
2184 				if (urb->dev->tt->hub)
2185 					qh->h_addr_reg =
2186 						(u8) urb->dev->tt->hub->devnum;
2187 				if (urb->dev->tt->multi)
2188 					qh->h_addr_reg |= 0x80;
2189 			}
2190 		}
2191 	}
2192 
2193 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2194 	 * until we get real dma queues (with an entry for each urb/buffer),
2195 	 * we only have work to do in the former case.
2196 	 */
2197 	spin_lock_irqsave(&musb->lock, flags);
2198 	if (hep->hcpriv || !next_urb(qh)) {
2199 		/* some concurrent activity submitted another urb to hep...
2200 		 * odd, rare, error prone, but legal.
2201 		 */
2202 		kfree(qh);
2203 		qh = NULL;
2204 		ret = 0;
2205 	} else
2206 		ret = musb_schedule(musb, qh,
2207 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2208 
2209 	if (ret == 0) {
2210 		urb->hcpriv = qh;
2211 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2212 		 * musb_start_urb(), but otherwise only konicawc cares ...
2213 		 */
2214 	}
2215 	spin_unlock_irqrestore(&musb->lock, flags);
2216 
2217 done:
2218 	if (ret != 0) {
2219 		spin_lock_irqsave(&musb->lock, flags);
2220 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2221 		spin_unlock_irqrestore(&musb->lock, flags);
2222 		kfree(qh);
2223 	}
2224 	return ret;
2225 }
2226 
2227 
2228 /*
2229  * abort a transfer that's at the head of a hardware queue.
2230  * called with controller locked, irqs blocked
2231  * that hardware queue advances to the next transfer, unless prevented
2232  */
2233 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2234 {
2235 	struct musb_hw_ep	*ep = qh->hw_ep;
2236 	struct musb		*musb = ep->musb;
2237 	void __iomem		*epio = ep->regs;
2238 	unsigned		hw_end = ep->epnum;
2239 	void __iomem		*regs = ep->musb->mregs;
2240 	int			is_in = usb_pipein(urb->pipe);
2241 	int			status = 0;
2242 	u16			csr;
2243 
2244 	musb_ep_select(regs, hw_end);
2245 
2246 	if (is_dma_capable()) {
2247 		struct dma_channel	*dma;
2248 
2249 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2250 		if (dma) {
2251 			status = ep->musb->dma_controller->channel_abort(dma);
2252 			dev_dbg(musb->controller,
2253 				"abort %cX%d DMA for urb %p --> %d\n",
2254 				is_in ? 'R' : 'T', ep->epnum,
2255 				urb, status);
2256 			urb->actual_length += dma->actual_len;
2257 		}
2258 	}
2259 
2260 	/* turn off DMA requests, discard state, stop polling ... */
2261 	if (ep->epnum && is_in) {
2262 		/* giveback saves bulk toggle */
2263 		csr = musb_h_flush_rxfifo(ep, 0);
2264 
2265 		/* REVISIT we still get an irq; should likely clear the
2266 		 * endpoint's irq status here to avoid bogus irqs.
2267 		 * clearing that status is platform-specific...
2268 		 */
2269 	} else if (ep->epnum) {
2270 		musb_h_tx_flush_fifo(ep);
2271 		csr = musb_readw(epio, MUSB_TXCSR);
2272 		csr &= ~(MUSB_TXCSR_AUTOSET
2273 			| MUSB_TXCSR_DMAENAB
2274 			| MUSB_TXCSR_H_RXSTALL
2275 			| MUSB_TXCSR_H_NAKTIMEOUT
2276 			| MUSB_TXCSR_H_ERROR
2277 			| MUSB_TXCSR_TXPKTRDY);
2278 		musb_writew(epio, MUSB_TXCSR, csr);
2279 		/* REVISIT may need to clear FLUSHFIFO ... */
2280 		musb_writew(epio, MUSB_TXCSR, csr);
2281 		/* flush cpu writebuffer */
2282 		csr = musb_readw(epio, MUSB_TXCSR);
2283 	} else  {
2284 		musb_h_ep0_flush_fifo(ep);
2285 	}
2286 	if (status == 0)
2287 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2288 	return status;
2289 }
2290 
2291 static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
2292 {
2293 	struct musb		*musb = hcd_to_musb(hcd);
2294 	struct musb_qh		*qh;
2295 	unsigned long		flags;
2296 	int			is_in  = usb_pipein(urb->pipe);
2297 	int			ret;
2298 
2299 	dev_dbg(musb->controller, "urb=%p, dev%d ep%d%s\n", urb,
2300 			usb_pipedevice(urb->pipe),
2301 			usb_pipeendpoint(urb->pipe),
2302 			is_in ? "in" : "out");
2303 
2304 	spin_lock_irqsave(&musb->lock, flags);
2305 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2306 	if (ret)
2307 		goto done;
2308 
2309 	qh = urb->hcpriv;
2310 	if (!qh)
2311 		goto done;
2312 
2313 	/*
2314 	 * Any URB not actively programmed into endpoint hardware can be
2315 	 * immediately given back; that's any URB not at the head of an
2316 	 * endpoint queue, unless someday we get real DMA queues.  And even
2317 	 * if it's at the head, it might not be known to the hardware...
2318 	 *
2319 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2320 	 * has already been updated.  This is a synchronous abort; it'd be
2321 	 * OK to hold off until after some IRQ, though.
2322 	 *
2323 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2324 	 */
2325 	if (!qh->is_ready
2326 			|| urb->urb_list.prev != &qh->hep->urb_list
2327 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2328 		int	ready = qh->is_ready;
2329 
2330 		qh->is_ready = 0;
2331 		musb_giveback(musb, urb, 0);
2332 		qh->is_ready = ready;
2333 
2334 		/* If nothing else (usually musb_giveback) is using it
2335 		 * and its URB list has emptied, recycle this qh.
2336 		 */
2337 		if (ready && list_empty(&qh->hep->urb_list)) {
2338 			qh->hep->hcpriv = NULL;
2339 			list_del(&qh->ring);
2340 			kfree(qh);
2341 		}
2342 	} else
2343 		ret = musb_cleanup_urb(urb, qh);
2344 done:
2345 	spin_unlock_irqrestore(&musb->lock, flags);
2346 	return ret;
2347 }
2348 
2349 /* disable an endpoint */
2350 static void
2351 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2352 {
2353 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2354 	unsigned long		flags;
2355 	struct musb		*musb = hcd_to_musb(hcd);
2356 	struct musb_qh		*qh;
2357 	struct urb		*urb;
2358 
2359 	spin_lock_irqsave(&musb->lock, flags);
2360 
2361 	qh = hep->hcpriv;
2362 	if (qh == NULL)
2363 		goto exit;
2364 
2365 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2366 
2367 	/* Kick the first URB off the hardware, if needed */
2368 	qh->is_ready = 0;
2369 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2370 		urb = next_urb(qh);
2371 
2372 		/* make software (then hardware) stop ASAP */
2373 		if (!urb->unlinked)
2374 			urb->status = -ESHUTDOWN;
2375 
2376 		/* cleanup */
2377 		musb_cleanup_urb(urb, qh);
2378 
2379 		/* Then nuke all the others ... and advance the
2380 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2381 		 */
2382 		while (!list_empty(&hep->urb_list)) {
2383 			urb = next_urb(qh);
2384 			urb->status = -ESHUTDOWN;
2385 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2386 		}
2387 	} else {
2388 		/* Just empty the queue; the hardware is busy with
2389 		 * other transfers, and since !qh->is_ready nothing
2390 		 * will activate any of these as it advances.
2391 		 */
2392 		while (!list_empty(&hep->urb_list))
2393 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2394 
2395 		hep->hcpriv = NULL;
2396 		list_del(&qh->ring);
2397 		kfree(qh);
2398 	}
2399 exit:
2400 	spin_unlock_irqrestore(&musb->lock, flags);
2401 }
2402 
2403 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2404 {
2405 	struct musb	*musb = hcd_to_musb(hcd);
2406 
2407 	return musb_readw(musb->mregs, MUSB_FRAME);
2408 }
2409 
2410 static int musb_h_start(struct usb_hcd *hcd)
2411 {
2412 	struct musb	*musb = hcd_to_musb(hcd);
2413 
2414 	/* NOTE: musb_start() is called when the hub driver turns
2415 	 * on port power, or when (OTG) peripheral starts.
2416 	 */
2417 	hcd->state = HC_STATE_RUNNING;
2418 	musb->port1_status = 0;
2419 	return 0;
2420 }
2421 
2422 static void musb_h_stop(struct usb_hcd *hcd)
2423 {
2424 	musb_stop(hcd_to_musb(hcd));
2425 	hcd->state = HC_STATE_HALT;
2426 }
2427 
2428 static int musb_bus_suspend(struct usb_hcd *hcd)
2429 {
2430 	struct musb	*musb = hcd_to_musb(hcd);
2431 	u8		devctl;
2432 
2433 	if (!is_host_active(musb))
2434 		return 0;
2435 
2436 	switch (musb->xceiv->state) {
2437 	case OTG_STATE_A_SUSPEND:
2438 		return 0;
2439 	case OTG_STATE_A_WAIT_VRISE:
2440 		/* ID could be grounded even if there's no device
2441 		 * on the other end of the cable.  NOTE that the
2442 		 * A_WAIT_VRISE timers are messy with MUSB...
2443 		 */
2444 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2445 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2446 			musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2447 		break;
2448 	default:
2449 		break;
2450 	}
2451 
2452 	if (musb->is_active) {
2453 		WARNING("trying to suspend as %s while active\n",
2454 				usb_otg_state_string(musb->xceiv->state));
2455 		return -EBUSY;
2456 	} else
2457 		return 0;
2458 }
2459 
2460 static int musb_bus_resume(struct usb_hcd *hcd)
2461 {
2462 	/* resuming child port does the work */
2463 	return 0;
2464 }
2465 
2466 
2467 #ifndef CONFIG_MUSB_PIO_ONLY
2468 
2469 #define MUSB_USB_DMA_ALIGN 4
2470 
2471 struct musb_temp_buffer {
2472 	void *kmalloc_ptr;
2473 	void *old_xfer_buffer;
2474 	u8 data[0];
2475 };
2476 
2477 static void musb_free_temp_buffer(struct urb *urb)
2478 {
2479 	enum dma_data_direction dir;
2480 	struct musb_temp_buffer *temp;
2481 
2482 	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
2483 		return;
2484 
2485 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2486 
2487 	temp = container_of(urb->transfer_buffer, struct musb_temp_buffer,
2488 			    data);
2489 
2490 	if (dir == DMA_FROM_DEVICE) {
2491 		memcpy(temp->old_xfer_buffer, temp->data,
2492 		       urb->transfer_buffer_length);
2493 	}
2494 	urb->transfer_buffer = temp->old_xfer_buffer;
2495 	kfree(temp->kmalloc_ptr);
2496 
2497 	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
2498 }
2499 
2500 static int musb_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
2501 {
2502 	enum dma_data_direction dir;
2503 	struct musb_temp_buffer *temp;
2504 	void *kmalloc_ptr;
2505 	size_t kmalloc_size;
2506 
2507 	if (urb->num_sgs || urb->sg ||
2508 	    urb->transfer_buffer_length == 0 ||
2509 	    !((uintptr_t)urb->transfer_buffer & (MUSB_USB_DMA_ALIGN - 1)))
2510 		return 0;
2511 
2512 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2513 
2514 	/* Allocate a buffer with enough padding for alignment */
2515 	kmalloc_size = urb->transfer_buffer_length +
2516 		sizeof(struct musb_temp_buffer) + MUSB_USB_DMA_ALIGN - 1;
2517 
2518 	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
2519 	if (!kmalloc_ptr)
2520 		return -ENOMEM;
2521 
2522 	/* Position our struct temp_buffer such that data is aligned */
2523 	temp = PTR_ALIGN(kmalloc_ptr, MUSB_USB_DMA_ALIGN);
2524 
2525 
2526 	temp->kmalloc_ptr = kmalloc_ptr;
2527 	temp->old_xfer_buffer = urb->transfer_buffer;
2528 	if (dir == DMA_TO_DEVICE)
2529 		memcpy(temp->data, urb->transfer_buffer,
2530 		       urb->transfer_buffer_length);
2531 	urb->transfer_buffer = temp->data;
2532 
2533 	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
2534 
2535 	return 0;
2536 }
2537 
2538 static int musb_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
2539 				      gfp_t mem_flags)
2540 {
2541 	struct musb	*musb = hcd_to_musb(hcd);
2542 	int ret;
2543 
2544 	/*
2545 	 * The DMA engine in RTL1.8 and above cannot handle
2546 	 * DMA addresses that are not aligned to a 4 byte boundary.
2547 	 * For such engine implemented (un)map_urb_for_dma hooks.
2548 	 * Do not use these hooks for RTL<1.8
2549 	 */
2550 	if (musb->hwvers < MUSB_HWVERS_1800)
2551 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2552 
2553 	ret = musb_alloc_temp_buffer(urb, mem_flags);
2554 	if (ret)
2555 		return ret;
2556 
2557 	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2558 	if (ret)
2559 		musb_free_temp_buffer(urb);
2560 
2561 	return ret;
2562 }
2563 
2564 static void musb_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
2565 {
2566 	struct musb	*musb = hcd_to_musb(hcd);
2567 
2568 	usb_hcd_unmap_urb_for_dma(hcd, urb);
2569 
2570 	/* Do not use this hook for RTL<1.8 (see description above) */
2571 	if (musb->hwvers < MUSB_HWVERS_1800)
2572 		return;
2573 
2574 	musb_free_temp_buffer(urb);
2575 }
2576 #endif /* !CONFIG_MUSB_PIO_ONLY */
2577 
2578 const struct hc_driver musb_hc_driver = {
2579 	.description		= "musb-hcd",
2580 	.product_desc		= "MUSB HDRC host driver",
2581 	.hcd_priv_size		= sizeof(struct musb),
2582 	.flags			= HCD_USB2 | HCD_MEMORY,
2583 
2584 	/* not using irq handler or reset hooks from usbcore, since
2585 	 * those must be shared with peripheral code for OTG configs
2586 	 */
2587 
2588 	.start			= musb_h_start,
2589 	.stop			= musb_h_stop,
2590 
2591 	.get_frame_number	= musb_h_get_frame_number,
2592 
2593 	.urb_enqueue		= musb_urb_enqueue,
2594 	.urb_dequeue		= musb_urb_dequeue,
2595 	.endpoint_disable	= musb_h_disable,
2596 
2597 #ifndef CONFIG_MUSB_PIO_ONLY
2598 	.map_urb_for_dma	= musb_map_urb_for_dma,
2599 	.unmap_urb_for_dma	= musb_unmap_urb_for_dma,
2600 #endif
2601 
2602 	.hub_status_data	= musb_hub_status_data,
2603 	.hub_control		= musb_hub_control,
2604 	.bus_suspend		= musb_bus_suspend,
2605 	.bus_resume		= musb_bus_resume,
2606 	/* .start_port_reset	= NULL, */
2607 	/* .hub_irq_enable	= NULL, */
2608 };
2609