xref: /openbmc/linux/drivers/usb/musb/musb_host.c (revision 5f32c314)
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/list.h>
43 #include <linux/dma-mapping.h>
44 
45 #include "musb_core.h"
46 #include "musb_host.h"
47 
48 /* MUSB HOST status 22-mar-2006
49  *
50  * - There's still lots of partial code duplication for fault paths, so
51  *   they aren't handled as consistently as they need to be.
52  *
53  * - PIO mostly behaved when last tested.
54  *     + including ep0, with all usbtest cases 9, 10
55  *     + usbtest 14 (ep0out) doesn't seem to run at all
56  *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
57  *       configurations, but otherwise double buffering passes basic tests.
58  *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
59  *
60  * - DMA (CPPI) ... partially behaves, not currently recommended
61  *     + about 1/15 the speed of typical EHCI implementations (PCI)
62  *     + RX, all too often reqpkt seems to misbehave after tx
63  *     + TX, no known issues (other than evident silicon issue)
64  *
65  * - DMA (Mentor/OMAP) ...has at least toggle update problems
66  *
67  * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
68  *   starvation ... nothing yet for TX, interrupt, or bulk.
69  *
70  * - Not tested with HNP, but some SRP paths seem to behave.
71  *
72  * NOTE 24-August-2006:
73  *
74  * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
75  *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
76  *   mostly works, except that with "usbnet" it's easy to trigger cases
77  *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
78  *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
79  *   although ARP RX wins.  (That test was done with a full speed link.)
80  */
81 
82 
83 /*
84  * NOTE on endpoint usage:
85  *
86  * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
87  * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
88  * (Yes, bulk _could_ use more of the endpoints than that, and would even
89  * benefit from it.)
90  *
91  * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
92  * So far that scheduling is both dumb and optimistic:  the endpoint will be
93  * "claimed" until its software queue is no longer refilled.  No multiplexing
94  * of transfers between endpoints, or anything clever.
95  */
96 
97 struct musb *hcd_to_musb(struct usb_hcd *hcd)
98 {
99 	return *(struct musb **) hcd->hcd_priv;
100 }
101 
102 
103 static void musb_ep_program(struct musb *musb, u8 epnum,
104 			struct urb *urb, int is_out,
105 			u8 *buf, u32 offset, u32 len);
106 
107 /*
108  * Clear TX fifo. Needed to avoid BABBLE errors.
109  */
110 static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
111 {
112 	struct musb	*musb = ep->musb;
113 	void __iomem	*epio = ep->regs;
114 	u16		csr;
115 	u16		lastcsr = 0;
116 	int		retries = 1000;
117 
118 	csr = musb_readw(epio, MUSB_TXCSR);
119 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
120 		if (csr != lastcsr)
121 			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
122 		lastcsr = csr;
123 		csr |= MUSB_TXCSR_FLUSHFIFO;
124 		musb_writew(epio, MUSB_TXCSR, csr);
125 		csr = musb_readw(epio, MUSB_TXCSR);
126 		if (WARN(retries-- < 1,
127 				"Could not flush host TX%d fifo: csr: %04x\n",
128 				ep->epnum, csr))
129 			return;
130 		mdelay(1);
131 	}
132 }
133 
134 static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
135 {
136 	void __iomem	*epio = ep->regs;
137 	u16		csr;
138 	int		retries = 5;
139 
140 	/* scrub any data left in the fifo */
141 	do {
142 		csr = musb_readw(epio, MUSB_TXCSR);
143 		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
144 			break;
145 		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
146 		csr = musb_readw(epio, MUSB_TXCSR);
147 		udelay(10);
148 	} while (--retries);
149 
150 	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
151 			ep->epnum, csr);
152 
153 	/* and reset for the next transfer */
154 	musb_writew(epio, MUSB_TXCSR, 0);
155 }
156 
157 /*
158  * Start transmit. Caller is responsible for locking shared resources.
159  * musb must be locked.
160  */
161 static inline void musb_h_tx_start(struct musb_hw_ep *ep)
162 {
163 	u16	txcsr;
164 
165 	/* NOTE: no locks here; caller should lock and select EP */
166 	if (ep->epnum) {
167 		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
168 		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
169 		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
170 	} else {
171 		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
172 		musb_writew(ep->regs, MUSB_CSR0, txcsr);
173 	}
174 
175 }
176 
177 static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
178 {
179 	u16	txcsr;
180 
181 	/* NOTE: no locks here; caller should lock and select EP */
182 	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
183 	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
184 	if (is_cppi_enabled())
185 		txcsr |= MUSB_TXCSR_DMAMODE;
186 	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
187 }
188 
189 static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
190 {
191 	if (is_in != 0 || ep->is_shared_fifo)
192 		ep->in_qh  = qh;
193 	if (is_in == 0 || ep->is_shared_fifo)
194 		ep->out_qh = qh;
195 }
196 
197 static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
198 {
199 	return is_in ? ep->in_qh : ep->out_qh;
200 }
201 
202 /*
203  * Start the URB at the front of an endpoint's queue
204  * end must be claimed from the caller.
205  *
206  * Context: controller locked, irqs blocked
207  */
208 static void
209 musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
210 {
211 	u16			frame;
212 	u32			len;
213 	void __iomem		*mbase =  musb->mregs;
214 	struct urb		*urb = next_urb(qh);
215 	void			*buf = urb->transfer_buffer;
216 	u32			offset = 0;
217 	struct musb_hw_ep	*hw_ep = qh->hw_ep;
218 	unsigned		pipe = urb->pipe;
219 	u8			address = usb_pipedevice(pipe);
220 	int			epnum = hw_ep->epnum;
221 
222 	/* initialize software qh state */
223 	qh->offset = 0;
224 	qh->segsize = 0;
225 
226 	/* gather right source of data */
227 	switch (qh->type) {
228 	case USB_ENDPOINT_XFER_CONTROL:
229 		/* control transfers always start with SETUP */
230 		is_in = 0;
231 		musb->ep0_stage = MUSB_EP0_START;
232 		buf = urb->setup_packet;
233 		len = 8;
234 		break;
235 	case USB_ENDPOINT_XFER_ISOC:
236 		qh->iso_idx = 0;
237 		qh->frame = 0;
238 		offset = urb->iso_frame_desc[0].offset;
239 		len = urb->iso_frame_desc[0].length;
240 		break;
241 	default:		/* bulk, interrupt */
242 		/* actual_length may be nonzero on retry paths */
243 		buf = urb->transfer_buffer + urb->actual_length;
244 		len = urb->transfer_buffer_length - urb->actual_length;
245 	}
246 
247 	dev_dbg(musb->controller, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
248 			qh, urb, address, qh->epnum,
249 			is_in ? "in" : "out",
250 			({char *s; switch (qh->type) {
251 			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
252 			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
253 			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
254 			default:			s = "-intr"; break;
255 			} s; }),
256 			epnum, buf + offset, len);
257 
258 	/* Configure endpoint */
259 	musb_ep_set_qh(hw_ep, is_in, qh);
260 	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
261 
262 	/* transmit may have more work: start it when it is time */
263 	if (is_in)
264 		return;
265 
266 	/* determine if the time is right for a periodic transfer */
267 	switch (qh->type) {
268 	case USB_ENDPOINT_XFER_ISOC:
269 	case USB_ENDPOINT_XFER_INT:
270 		dev_dbg(musb->controller, "check whether there's still time for periodic Tx\n");
271 		frame = musb_readw(mbase, MUSB_FRAME);
272 		/* FIXME this doesn't implement that scheduling policy ...
273 		 * or handle framecounter wrapping
274 		 */
275 		if (1) {	/* Always assume URB_ISO_ASAP */
276 			/* REVISIT the SOF irq handler shouldn't duplicate
277 			 * this code; and we don't init urb->start_frame...
278 			 */
279 			qh->frame = 0;
280 			goto start;
281 		} else {
282 			qh->frame = urb->start_frame;
283 			/* enable SOF interrupt so we can count down */
284 			dev_dbg(musb->controller, "SOF for %d\n", epnum);
285 #if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
286 			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
287 #endif
288 		}
289 		break;
290 	default:
291 start:
292 		dev_dbg(musb->controller, "Start TX%d %s\n", epnum,
293 			hw_ep->tx_channel ? "dma" : "pio");
294 
295 		if (!hw_ep->tx_channel)
296 			musb_h_tx_start(hw_ep);
297 		else if (is_cppi_enabled() || tusb_dma_omap())
298 			musb_h_tx_dma_start(hw_ep);
299 	}
300 }
301 
302 /* Context: caller owns controller lock, IRQs are blocked */
303 static void musb_giveback(struct musb *musb, struct urb *urb, int status)
304 __releases(musb->lock)
305 __acquires(musb->lock)
306 {
307 	dev_dbg(musb->controller,
308 			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
309 			urb, urb->complete, status,
310 			usb_pipedevice(urb->pipe),
311 			usb_pipeendpoint(urb->pipe),
312 			usb_pipein(urb->pipe) ? "in" : "out",
313 			urb->actual_length, urb->transfer_buffer_length
314 			);
315 
316 	usb_hcd_unlink_urb_from_ep(musb->hcd, urb);
317 	spin_unlock(&musb->lock);
318 	usb_hcd_giveback_urb(musb->hcd, urb, status);
319 	spin_lock(&musb->lock);
320 }
321 
322 /* For bulk/interrupt endpoints only */
323 static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
324 				    struct urb *urb)
325 {
326 	void __iomem		*epio = qh->hw_ep->regs;
327 	u16			csr;
328 
329 	/*
330 	 * FIXME: the current Mentor DMA code seems to have
331 	 * problems getting toggle correct.
332 	 */
333 
334 	if (is_in)
335 		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
336 	else
337 		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
338 
339 	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
340 }
341 
342 /*
343  * Advance this hardware endpoint's queue, completing the specified URB and
344  * advancing to either the next URB queued to that qh, or else invalidating
345  * that qh and advancing to the next qh scheduled after the current one.
346  *
347  * Context: caller owns controller lock, IRQs are blocked
348  */
349 static void musb_advance_schedule(struct musb *musb, struct urb *urb,
350 				  struct musb_hw_ep *hw_ep, int is_in)
351 {
352 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
353 	struct musb_hw_ep	*ep = qh->hw_ep;
354 	int			ready = qh->is_ready;
355 	int			status;
356 
357 	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
358 
359 	/* save toggle eagerly, for paranoia */
360 	switch (qh->type) {
361 	case USB_ENDPOINT_XFER_BULK:
362 	case USB_ENDPOINT_XFER_INT:
363 		musb_save_toggle(qh, is_in, urb);
364 		break;
365 	case USB_ENDPOINT_XFER_ISOC:
366 		if (status == 0 && urb->error_count)
367 			status = -EXDEV;
368 		break;
369 	}
370 
371 	qh->is_ready = 0;
372 	musb_giveback(musb, urb, status);
373 	qh->is_ready = ready;
374 
375 	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
376 	 * invalidate qh as soon as list_empty(&hep->urb_list)
377 	 */
378 	if (list_empty(&qh->hep->urb_list)) {
379 		struct list_head	*head;
380 		struct dma_controller	*dma = musb->dma_controller;
381 
382 		if (is_in) {
383 			ep->rx_reinit = 1;
384 			if (ep->rx_channel) {
385 				dma->channel_release(ep->rx_channel);
386 				ep->rx_channel = NULL;
387 			}
388 		} else {
389 			ep->tx_reinit = 1;
390 			if (ep->tx_channel) {
391 				dma->channel_release(ep->tx_channel);
392 				ep->tx_channel = NULL;
393 			}
394 		}
395 
396 		/* Clobber old pointers to this qh */
397 		musb_ep_set_qh(ep, is_in, NULL);
398 		qh->hep->hcpriv = NULL;
399 
400 		switch (qh->type) {
401 
402 		case USB_ENDPOINT_XFER_CONTROL:
403 		case USB_ENDPOINT_XFER_BULK:
404 			/* fifo policy for these lists, except that NAKing
405 			 * should rotate a qh to the end (for fairness).
406 			 */
407 			if (qh->mux == 1) {
408 				head = qh->ring.prev;
409 				list_del(&qh->ring);
410 				kfree(qh);
411 				qh = first_qh(head);
412 				break;
413 			}
414 
415 		case USB_ENDPOINT_XFER_ISOC:
416 		case USB_ENDPOINT_XFER_INT:
417 			/* this is where periodic bandwidth should be
418 			 * de-allocated if it's tracked and allocated;
419 			 * and where we'd update the schedule tree...
420 			 */
421 			kfree(qh);
422 			qh = NULL;
423 			break;
424 		}
425 	}
426 
427 	if (qh != NULL && qh->is_ready) {
428 		dev_dbg(musb->controller, "... next ep%d %cX urb %p\n",
429 		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
430 		musb_start_urb(musb, is_in, qh);
431 	}
432 }
433 
434 static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
435 {
436 	/* we don't want fifo to fill itself again;
437 	 * ignore dma (various models),
438 	 * leave toggle alone (may not have been saved yet)
439 	 */
440 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
441 	csr &= ~(MUSB_RXCSR_H_REQPKT
442 		| MUSB_RXCSR_H_AUTOREQ
443 		| MUSB_RXCSR_AUTOCLEAR);
444 
445 	/* write 2x to allow double buffering */
446 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
447 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
448 
449 	/* flush writebuffer */
450 	return musb_readw(hw_ep->regs, MUSB_RXCSR);
451 }
452 
453 /*
454  * PIO RX for a packet (or part of it).
455  */
456 static bool
457 musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
458 {
459 	u16			rx_count;
460 	u8			*buf;
461 	u16			csr;
462 	bool			done = false;
463 	u32			length;
464 	int			do_flush = 0;
465 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
466 	void __iomem		*epio = hw_ep->regs;
467 	struct musb_qh		*qh = hw_ep->in_qh;
468 	int			pipe = urb->pipe;
469 	void			*buffer = urb->transfer_buffer;
470 
471 	/* musb_ep_select(mbase, epnum); */
472 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
473 	dev_dbg(musb->controller, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
474 			urb->transfer_buffer, qh->offset,
475 			urb->transfer_buffer_length);
476 
477 	/* unload FIFO */
478 	if (usb_pipeisoc(pipe)) {
479 		int					status = 0;
480 		struct usb_iso_packet_descriptor	*d;
481 
482 		if (iso_err) {
483 			status = -EILSEQ;
484 			urb->error_count++;
485 		}
486 
487 		d = urb->iso_frame_desc + qh->iso_idx;
488 		buf = buffer + d->offset;
489 		length = d->length;
490 		if (rx_count > length) {
491 			if (status == 0) {
492 				status = -EOVERFLOW;
493 				urb->error_count++;
494 			}
495 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
496 			do_flush = 1;
497 		} else
498 			length = rx_count;
499 		urb->actual_length += length;
500 		d->actual_length = length;
501 
502 		d->status = status;
503 
504 		/* see if we are done */
505 		done = (++qh->iso_idx >= urb->number_of_packets);
506 	} else {
507 		/* non-isoch */
508 		buf = buffer + qh->offset;
509 		length = urb->transfer_buffer_length - qh->offset;
510 		if (rx_count > length) {
511 			if (urb->status == -EINPROGRESS)
512 				urb->status = -EOVERFLOW;
513 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
514 			do_flush = 1;
515 		} else
516 			length = rx_count;
517 		urb->actual_length += length;
518 		qh->offset += length;
519 
520 		/* see if we are done */
521 		done = (urb->actual_length == urb->transfer_buffer_length)
522 			|| (rx_count < qh->maxpacket)
523 			|| (urb->status != -EINPROGRESS);
524 		if (done
525 				&& (urb->status == -EINPROGRESS)
526 				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
527 				&& (urb->actual_length
528 					< urb->transfer_buffer_length))
529 			urb->status = -EREMOTEIO;
530 	}
531 
532 	musb_read_fifo(hw_ep, length, buf);
533 
534 	csr = musb_readw(epio, MUSB_RXCSR);
535 	csr |= MUSB_RXCSR_H_WZC_BITS;
536 	if (unlikely(do_flush))
537 		musb_h_flush_rxfifo(hw_ep, csr);
538 	else {
539 		/* REVISIT this assumes AUTOCLEAR is never set */
540 		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
541 		if (!done)
542 			csr |= MUSB_RXCSR_H_REQPKT;
543 		musb_writew(epio, MUSB_RXCSR, csr);
544 	}
545 
546 	return done;
547 }
548 
549 /* we don't always need to reinit a given side of an endpoint...
550  * when we do, use tx/rx reinit routine and then construct a new CSR
551  * to address data toggle, NYET, and DMA or PIO.
552  *
553  * it's possible that driver bugs (especially for DMA) or aborting a
554  * transfer might have left the endpoint busier than it should be.
555  * the busy/not-empty tests are basically paranoia.
556  */
557 static void
558 musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
559 {
560 	u16	csr;
561 
562 	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
563 	 * That always uses tx_reinit since ep0 repurposes TX register
564 	 * offsets; the initial SETUP packet is also a kind of OUT.
565 	 */
566 
567 	/* if programmed for Tx, put it in RX mode */
568 	if (ep->is_shared_fifo) {
569 		csr = musb_readw(ep->regs, MUSB_TXCSR);
570 		if (csr & MUSB_TXCSR_MODE) {
571 			musb_h_tx_flush_fifo(ep);
572 			csr = musb_readw(ep->regs, MUSB_TXCSR);
573 			musb_writew(ep->regs, MUSB_TXCSR,
574 				    csr | MUSB_TXCSR_FRCDATATOG);
575 		}
576 
577 		/*
578 		 * Clear the MODE bit (and everything else) to enable Rx.
579 		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
580 		 */
581 		if (csr & MUSB_TXCSR_DMAMODE)
582 			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
583 		musb_writew(ep->regs, MUSB_TXCSR, 0);
584 
585 	/* scrub all previous state, clearing toggle */
586 	} else {
587 		csr = musb_readw(ep->regs, MUSB_RXCSR);
588 		if (csr & MUSB_RXCSR_RXPKTRDY)
589 			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
590 				musb_readw(ep->regs, MUSB_RXCOUNT));
591 
592 		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
593 	}
594 
595 	/* target addr and (for multipoint) hub addr/port */
596 	if (musb->is_multipoint) {
597 		musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
598 		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
599 		musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
600 
601 	} else
602 		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
603 
604 	/* protocol/endpoint, interval/NAKlimit, i/o size */
605 	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
606 	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
607 	/* NOTE: bulk combining rewrites high bits of maxpacket */
608 	/* Set RXMAXP with the FIFO size of the endpoint
609 	 * to disable double buffer mode.
610 	 */
611 	if (musb->double_buffer_not_ok)
612 		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
613 	else
614 		musb_writew(ep->regs, MUSB_RXMAXP,
615 				qh->maxpacket | ((qh->hb_mult - 1) << 11));
616 
617 	ep->rx_reinit = 0;
618 }
619 
620 static bool musb_tx_dma_program(struct dma_controller *dma,
621 		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
622 		struct urb *urb, u32 offset, u32 length)
623 {
624 	struct dma_channel	*channel = hw_ep->tx_channel;
625 	void __iomem		*epio = hw_ep->regs;
626 	u16			pkt_size = qh->maxpacket;
627 	u16			csr;
628 	u8			mode;
629 
630 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
631 	if (length > channel->max_len)
632 		length = channel->max_len;
633 
634 	csr = musb_readw(epio, MUSB_TXCSR);
635 	if (length > pkt_size) {
636 		mode = 1;
637 		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
638 		/* autoset shouldn't be set in high bandwidth */
639 		/*
640 		 * Enable Autoset according to table
641 		 * below
642 		 * bulk_split hb_mult	Autoset_Enable
643 		 *	0	1	Yes(Normal)
644 		 *	0	>1	No(High BW ISO)
645 		 *	1	1	Yes(HS bulk)
646 		 *	1	>1	Yes(FS bulk)
647 		 */
648 		if (qh->hb_mult == 1 || (qh->hb_mult > 1 &&
649 					can_bulk_split(hw_ep->musb, qh->type)))
650 			csr |= MUSB_TXCSR_AUTOSET;
651 	} else {
652 		mode = 0;
653 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
654 		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
655 	}
656 	channel->desired_mode = mode;
657 	musb_writew(epio, MUSB_TXCSR, csr);
658 #else
659 	if (!is_cppi_enabled() && !tusb_dma_omap())
660 		return false;
661 
662 	channel->actual_len = 0;
663 
664 	/*
665 	 * TX uses "RNDIS" mode automatically but needs help
666 	 * to identify the zero-length-final-packet case.
667 	 */
668 	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
669 #endif
670 
671 	qh->segsize = length;
672 
673 	/*
674 	 * Ensure the data reaches to main memory before starting
675 	 * DMA transfer
676 	 */
677 	wmb();
678 
679 	if (!dma->channel_program(channel, pkt_size, mode,
680 			urb->transfer_dma + offset, length)) {
681 		dma->channel_release(channel);
682 		hw_ep->tx_channel = NULL;
683 
684 		csr = musb_readw(epio, MUSB_TXCSR);
685 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
686 		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
687 		return false;
688 	}
689 	return true;
690 }
691 
692 /*
693  * Program an HDRC endpoint as per the given URB
694  * Context: irqs blocked, controller lock held
695  */
696 static void musb_ep_program(struct musb *musb, u8 epnum,
697 			struct urb *urb, int is_out,
698 			u8 *buf, u32 offset, u32 len)
699 {
700 	struct dma_controller	*dma_controller;
701 	struct dma_channel	*dma_channel;
702 	u8			dma_ok;
703 	void __iomem		*mbase = musb->mregs;
704 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
705 	void __iomem		*epio = hw_ep->regs;
706 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
707 	u16			packet_sz = qh->maxpacket;
708 	u8			use_dma = 1;
709 	u16			csr;
710 
711 	dev_dbg(musb->controller, "%s hw%d urb %p spd%d dev%d ep%d%s "
712 				"h_addr%02x h_port%02x bytes %d\n",
713 			is_out ? "-->" : "<--",
714 			epnum, urb, urb->dev->speed,
715 			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
716 			qh->h_addr_reg, qh->h_port_reg,
717 			len);
718 
719 	musb_ep_select(mbase, epnum);
720 
721 	if (is_out && !len) {
722 		use_dma = 0;
723 		csr = musb_readw(epio, MUSB_TXCSR);
724 		csr &= ~MUSB_TXCSR_DMAENAB;
725 		musb_writew(epio, MUSB_TXCSR, csr);
726 		hw_ep->tx_channel = NULL;
727 	}
728 
729 	/* candidate for DMA? */
730 	dma_controller = musb->dma_controller;
731 	if (use_dma && is_dma_capable() && epnum && dma_controller) {
732 		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
733 		if (!dma_channel) {
734 			dma_channel = dma_controller->channel_alloc(
735 					dma_controller, hw_ep, is_out);
736 			if (is_out)
737 				hw_ep->tx_channel = dma_channel;
738 			else
739 				hw_ep->rx_channel = dma_channel;
740 		}
741 	} else
742 		dma_channel = NULL;
743 
744 	/* make sure we clear DMAEnab, autoSet bits from previous run */
745 
746 	/* OUT/transmit/EP0 or IN/receive? */
747 	if (is_out) {
748 		u16	csr;
749 		u16	int_txe;
750 		u16	load_count;
751 
752 		csr = musb_readw(epio, MUSB_TXCSR);
753 
754 		/* disable interrupt in case we flush */
755 		int_txe = musb->intrtxe;
756 		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
757 
758 		/* general endpoint setup */
759 		if (epnum) {
760 			/* flush all old state, set default */
761 			/*
762 			 * We could be flushing valid
763 			 * packets in double buffering
764 			 * case
765 			 */
766 			if (!hw_ep->tx_double_buffered)
767 				musb_h_tx_flush_fifo(hw_ep);
768 
769 			/*
770 			 * We must not clear the DMAMODE bit before or in
771 			 * the same cycle with the DMAENAB bit, so we clear
772 			 * the latter first...
773 			 */
774 			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
775 					| MUSB_TXCSR_AUTOSET
776 					| MUSB_TXCSR_DMAENAB
777 					| MUSB_TXCSR_FRCDATATOG
778 					| MUSB_TXCSR_H_RXSTALL
779 					| MUSB_TXCSR_H_ERROR
780 					| MUSB_TXCSR_TXPKTRDY
781 					);
782 			csr |= MUSB_TXCSR_MODE;
783 
784 			if (!hw_ep->tx_double_buffered) {
785 				if (usb_gettoggle(urb->dev, qh->epnum, 1))
786 					csr |= MUSB_TXCSR_H_WR_DATATOGGLE
787 						| MUSB_TXCSR_H_DATATOGGLE;
788 				else
789 					csr |= MUSB_TXCSR_CLRDATATOG;
790 			}
791 
792 			musb_writew(epio, MUSB_TXCSR, csr);
793 			/* REVISIT may need to clear FLUSHFIFO ... */
794 			csr &= ~MUSB_TXCSR_DMAMODE;
795 			musb_writew(epio, MUSB_TXCSR, csr);
796 			csr = musb_readw(epio, MUSB_TXCSR);
797 		} else {
798 			/* endpoint 0: just flush */
799 			musb_h_ep0_flush_fifo(hw_ep);
800 		}
801 
802 		/* target addr and (for multipoint) hub addr/port */
803 		if (musb->is_multipoint) {
804 			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
805 			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
806 			musb_write_txhubport(mbase, epnum, qh->h_port_reg);
807 /* FIXME if !epnum, do the same for RX ... */
808 		} else
809 			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
810 
811 		/* protocol/endpoint/interval/NAKlimit */
812 		if (epnum) {
813 			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
814 			if (musb->double_buffer_not_ok) {
815 				musb_writew(epio, MUSB_TXMAXP,
816 						hw_ep->max_packet_sz_tx);
817 			} else if (can_bulk_split(musb, qh->type)) {
818 				qh->hb_mult = hw_ep->max_packet_sz_tx
819 						/ packet_sz;
820 				musb_writew(epio, MUSB_TXMAXP, packet_sz
821 					| ((qh->hb_mult) - 1) << 11);
822 			} else {
823 				musb_writew(epio, MUSB_TXMAXP,
824 						qh->maxpacket |
825 						((qh->hb_mult - 1) << 11));
826 			}
827 			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
828 		} else {
829 			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
830 			if (musb->is_multipoint)
831 				musb_writeb(epio, MUSB_TYPE0,
832 						qh->type_reg);
833 		}
834 
835 		if (can_bulk_split(musb, qh->type))
836 			load_count = min((u32) hw_ep->max_packet_sz_tx,
837 						len);
838 		else
839 			load_count = min((u32) packet_sz, len);
840 
841 		if (dma_channel && musb_tx_dma_program(dma_controller,
842 					hw_ep, qh, urb, offset, len))
843 			load_count = 0;
844 
845 		if (load_count) {
846 			/* PIO to load FIFO */
847 			qh->segsize = load_count;
848 			if (!buf) {
849 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
850 						SG_MITER_ATOMIC
851 						| SG_MITER_FROM_SG);
852 				if (!sg_miter_next(&qh->sg_miter)) {
853 					dev_err(musb->controller,
854 							"error: sg"
855 							"list empty\n");
856 					sg_miter_stop(&qh->sg_miter);
857 					goto finish;
858 				}
859 				buf = qh->sg_miter.addr + urb->sg->offset +
860 					urb->actual_length;
861 				load_count = min_t(u32, load_count,
862 						qh->sg_miter.length);
863 				musb_write_fifo(hw_ep, load_count, buf);
864 				qh->sg_miter.consumed = load_count;
865 				sg_miter_stop(&qh->sg_miter);
866 			} else
867 				musb_write_fifo(hw_ep, load_count, buf);
868 		}
869 finish:
870 		/* re-enable interrupt */
871 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
872 
873 	/* IN/receive */
874 	} else {
875 		u16	csr;
876 
877 		if (hw_ep->rx_reinit) {
878 			musb_rx_reinit(musb, qh, hw_ep);
879 
880 			/* init new state: toggle and NYET, maybe DMA later */
881 			if (usb_gettoggle(urb->dev, qh->epnum, 0))
882 				csr = MUSB_RXCSR_H_WR_DATATOGGLE
883 					| MUSB_RXCSR_H_DATATOGGLE;
884 			else
885 				csr = 0;
886 			if (qh->type == USB_ENDPOINT_XFER_INT)
887 				csr |= MUSB_RXCSR_DISNYET;
888 
889 		} else {
890 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
891 
892 			if (csr & (MUSB_RXCSR_RXPKTRDY
893 					| MUSB_RXCSR_DMAENAB
894 					| MUSB_RXCSR_H_REQPKT))
895 				ERR("broken !rx_reinit, ep%d csr %04x\n",
896 						hw_ep->epnum, csr);
897 
898 			/* scrub any stale state, leaving toggle alone */
899 			csr &= MUSB_RXCSR_DISNYET;
900 		}
901 
902 		/* kick things off */
903 
904 		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
905 			/* Candidate for DMA */
906 			dma_channel->actual_len = 0L;
907 			qh->segsize = len;
908 
909 			/* AUTOREQ is in a DMA register */
910 			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
911 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
912 
913 			/*
914 			 * Unless caller treats short RX transfers as
915 			 * errors, we dare not queue multiple transfers.
916 			 */
917 			dma_ok = dma_controller->channel_program(dma_channel,
918 					packet_sz, !(urb->transfer_flags &
919 						     URB_SHORT_NOT_OK),
920 					urb->transfer_dma + offset,
921 					qh->segsize);
922 			if (!dma_ok) {
923 				dma_controller->channel_release(dma_channel);
924 				hw_ep->rx_channel = dma_channel = NULL;
925 			} else
926 				csr |= MUSB_RXCSR_DMAENAB;
927 		}
928 
929 		csr |= MUSB_RXCSR_H_REQPKT;
930 		dev_dbg(musb->controller, "RXCSR%d := %04x\n", epnum, csr);
931 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
932 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
933 	}
934 }
935 
936 /* Schedule next QH from musb->in_bulk/out_bulk and move the current qh to
937  * the end; avoids starvation for other endpoints.
938  */
939 static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep,
940 	int is_in)
941 {
942 	struct dma_channel	*dma;
943 	struct urb		*urb;
944 	void __iomem		*mbase = musb->mregs;
945 	void __iomem		*epio = ep->regs;
946 	struct musb_qh		*cur_qh, *next_qh;
947 	u16			rx_csr, tx_csr;
948 
949 	musb_ep_select(mbase, ep->epnum);
950 	if (is_in) {
951 		dma = is_dma_capable() ? ep->rx_channel : NULL;
952 
953 		/* clear nak timeout bit */
954 		rx_csr = musb_readw(epio, MUSB_RXCSR);
955 		rx_csr |= MUSB_RXCSR_H_WZC_BITS;
956 		rx_csr &= ~MUSB_RXCSR_DATAERROR;
957 		musb_writew(epio, MUSB_RXCSR, rx_csr);
958 
959 		cur_qh = first_qh(&musb->in_bulk);
960 	} else {
961 		dma = is_dma_capable() ? ep->tx_channel : NULL;
962 
963 		/* clear nak timeout bit */
964 		tx_csr = musb_readw(epio, MUSB_TXCSR);
965 		tx_csr |= MUSB_TXCSR_H_WZC_BITS;
966 		tx_csr &= ~MUSB_TXCSR_H_NAKTIMEOUT;
967 		musb_writew(epio, MUSB_TXCSR, tx_csr);
968 
969 		cur_qh = first_qh(&musb->out_bulk);
970 	}
971 	if (cur_qh) {
972 		urb = next_urb(cur_qh);
973 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
974 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
975 			musb->dma_controller->channel_abort(dma);
976 			urb->actual_length += dma->actual_len;
977 			dma->actual_len = 0L;
978 		}
979 		musb_save_toggle(cur_qh, is_in, urb);
980 
981 		if (is_in) {
982 			/* move cur_qh to end of queue */
983 			list_move_tail(&cur_qh->ring, &musb->in_bulk);
984 
985 			/* get the next qh from musb->in_bulk */
986 			next_qh = first_qh(&musb->in_bulk);
987 
988 			/* set rx_reinit and schedule the next qh */
989 			ep->rx_reinit = 1;
990 		} else {
991 			/* move cur_qh to end of queue */
992 			list_move_tail(&cur_qh->ring, &musb->out_bulk);
993 
994 			/* get the next qh from musb->out_bulk */
995 			next_qh = first_qh(&musb->out_bulk);
996 
997 			/* set tx_reinit and schedule the next qh */
998 			ep->tx_reinit = 1;
999 		}
1000 		musb_start_urb(musb, is_in, next_qh);
1001 	}
1002 }
1003 
1004 /*
1005  * Service the default endpoint (ep0) as host.
1006  * Return true until it's time to start the status stage.
1007  */
1008 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
1009 {
1010 	bool			 more = false;
1011 	u8			*fifo_dest = NULL;
1012 	u16			fifo_count = 0;
1013 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1014 	struct musb_qh		*qh = hw_ep->in_qh;
1015 	struct usb_ctrlrequest	*request;
1016 
1017 	switch (musb->ep0_stage) {
1018 	case MUSB_EP0_IN:
1019 		fifo_dest = urb->transfer_buffer + urb->actual_length;
1020 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
1021 				   urb->actual_length);
1022 		if (fifo_count < len)
1023 			urb->status = -EOVERFLOW;
1024 
1025 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
1026 
1027 		urb->actual_length += fifo_count;
1028 		if (len < qh->maxpacket) {
1029 			/* always terminate on short read; it's
1030 			 * rarely reported as an error.
1031 			 */
1032 		} else if (urb->actual_length <
1033 				urb->transfer_buffer_length)
1034 			more = true;
1035 		break;
1036 	case MUSB_EP0_START:
1037 		request = (struct usb_ctrlrequest *) urb->setup_packet;
1038 
1039 		if (!request->wLength) {
1040 			dev_dbg(musb->controller, "start no-DATA\n");
1041 			break;
1042 		} else if (request->bRequestType & USB_DIR_IN) {
1043 			dev_dbg(musb->controller, "start IN-DATA\n");
1044 			musb->ep0_stage = MUSB_EP0_IN;
1045 			more = true;
1046 			break;
1047 		} else {
1048 			dev_dbg(musb->controller, "start OUT-DATA\n");
1049 			musb->ep0_stage = MUSB_EP0_OUT;
1050 			more = true;
1051 		}
1052 		/* FALLTHROUGH */
1053 	case MUSB_EP0_OUT:
1054 		fifo_count = min_t(size_t, qh->maxpacket,
1055 				   urb->transfer_buffer_length -
1056 				   urb->actual_length);
1057 		if (fifo_count) {
1058 			fifo_dest = (u8 *) (urb->transfer_buffer
1059 					+ urb->actual_length);
1060 			dev_dbg(musb->controller, "Sending %d byte%s to ep0 fifo %p\n",
1061 					fifo_count,
1062 					(fifo_count == 1) ? "" : "s",
1063 					fifo_dest);
1064 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
1065 
1066 			urb->actual_length += fifo_count;
1067 			more = true;
1068 		}
1069 		break;
1070 	default:
1071 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
1072 		break;
1073 	}
1074 
1075 	return more;
1076 }
1077 
1078 /*
1079  * Handle default endpoint interrupt as host. Only called in IRQ time
1080  * from musb_interrupt().
1081  *
1082  * called with controller irqlocked
1083  */
1084 irqreturn_t musb_h_ep0_irq(struct musb *musb)
1085 {
1086 	struct urb		*urb;
1087 	u16			csr, len;
1088 	int			status = 0;
1089 	void __iomem		*mbase = musb->mregs;
1090 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1091 	void __iomem		*epio = hw_ep->regs;
1092 	struct musb_qh		*qh = hw_ep->in_qh;
1093 	bool			complete = false;
1094 	irqreturn_t		retval = IRQ_NONE;
1095 
1096 	/* ep0 only has one queue, "in" */
1097 	urb = next_urb(qh);
1098 
1099 	musb_ep_select(mbase, 0);
1100 	csr = musb_readw(epio, MUSB_CSR0);
1101 	len = (csr & MUSB_CSR0_RXPKTRDY)
1102 			? musb_readb(epio, MUSB_COUNT0)
1103 			: 0;
1104 
1105 	dev_dbg(musb->controller, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
1106 		csr, qh, len, urb, musb->ep0_stage);
1107 
1108 	/* if we just did status stage, we are done */
1109 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
1110 		retval = IRQ_HANDLED;
1111 		complete = true;
1112 	}
1113 
1114 	/* prepare status */
1115 	if (csr & MUSB_CSR0_H_RXSTALL) {
1116 		dev_dbg(musb->controller, "STALLING ENDPOINT\n");
1117 		status = -EPIPE;
1118 
1119 	} else if (csr & MUSB_CSR0_H_ERROR) {
1120 		dev_dbg(musb->controller, "no response, csr0 %04x\n", csr);
1121 		status = -EPROTO;
1122 
1123 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1124 		dev_dbg(musb->controller, "control NAK timeout\n");
1125 
1126 		/* NOTE:  this code path would be a good place to PAUSE a
1127 		 * control transfer, if another one is queued, so that
1128 		 * ep0 is more likely to stay busy.  That's already done
1129 		 * for bulk RX transfers.
1130 		 *
1131 		 * if (qh->ring.next != &musb->control), then
1132 		 * we have a candidate... NAKing is *NOT* an error
1133 		 */
1134 		musb_writew(epio, MUSB_CSR0, 0);
1135 		retval = IRQ_HANDLED;
1136 	}
1137 
1138 	if (status) {
1139 		dev_dbg(musb->controller, "aborting\n");
1140 		retval = IRQ_HANDLED;
1141 		if (urb)
1142 			urb->status = status;
1143 		complete = true;
1144 
1145 		/* use the proper sequence to abort the transfer */
1146 		if (csr & MUSB_CSR0_H_REQPKT) {
1147 			csr &= ~MUSB_CSR0_H_REQPKT;
1148 			musb_writew(epio, MUSB_CSR0, csr);
1149 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1150 			musb_writew(epio, MUSB_CSR0, csr);
1151 		} else {
1152 			musb_h_ep0_flush_fifo(hw_ep);
1153 		}
1154 
1155 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1156 
1157 		/* clear it */
1158 		musb_writew(epio, MUSB_CSR0, 0);
1159 	}
1160 
1161 	if (unlikely(!urb)) {
1162 		/* stop endpoint since we have no place for its data, this
1163 		 * SHOULD NEVER HAPPEN! */
1164 		ERR("no URB for end 0\n");
1165 
1166 		musb_h_ep0_flush_fifo(hw_ep);
1167 		goto done;
1168 	}
1169 
1170 	if (!complete) {
1171 		/* call common logic and prepare response */
1172 		if (musb_h_ep0_continue(musb, len, urb)) {
1173 			/* more packets required */
1174 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1175 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1176 		} else {
1177 			/* data transfer complete; perform status phase */
1178 			if (usb_pipeout(urb->pipe)
1179 					|| !urb->transfer_buffer_length)
1180 				csr = MUSB_CSR0_H_STATUSPKT
1181 					| MUSB_CSR0_H_REQPKT;
1182 			else
1183 				csr = MUSB_CSR0_H_STATUSPKT
1184 					| MUSB_CSR0_TXPKTRDY;
1185 
1186 			/* flag status stage */
1187 			musb->ep0_stage = MUSB_EP0_STATUS;
1188 
1189 			dev_dbg(musb->controller, "ep0 STATUS, csr %04x\n", csr);
1190 
1191 		}
1192 		musb_writew(epio, MUSB_CSR0, csr);
1193 		retval = IRQ_HANDLED;
1194 	} else
1195 		musb->ep0_stage = MUSB_EP0_IDLE;
1196 
1197 	/* call completion handler if done */
1198 	if (complete)
1199 		musb_advance_schedule(musb, urb, hw_ep, 1);
1200 done:
1201 	return retval;
1202 }
1203 
1204 
1205 #ifdef CONFIG_USB_INVENTRA_DMA
1206 
1207 /* Host side TX (OUT) using Mentor DMA works as follows:
1208 	submit_urb ->
1209 		- if queue was empty, Program Endpoint
1210 		- ... which starts DMA to fifo in mode 1 or 0
1211 
1212 	DMA Isr (transfer complete) -> TxAvail()
1213 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1214 					only in musb_cleanup_urb)
1215 		- TxPktRdy has to be set in mode 0 or for
1216 			short packets in mode 1.
1217 */
1218 
1219 #endif
1220 
1221 /* Service a Tx-Available or dma completion irq for the endpoint */
1222 void musb_host_tx(struct musb *musb, u8 epnum)
1223 {
1224 	int			pipe;
1225 	bool			done = false;
1226 	u16			tx_csr;
1227 	size_t			length = 0;
1228 	size_t			offset = 0;
1229 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1230 	void __iomem		*epio = hw_ep->regs;
1231 	struct musb_qh		*qh = hw_ep->out_qh;
1232 	struct urb		*urb = next_urb(qh);
1233 	u32			status = 0;
1234 	void __iomem		*mbase = musb->mregs;
1235 	struct dma_channel	*dma;
1236 	bool			transfer_pending = false;
1237 
1238 	musb_ep_select(mbase, epnum);
1239 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1240 
1241 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1242 	if (!urb) {
1243 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1244 		return;
1245 	}
1246 
1247 	pipe = urb->pipe;
1248 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1249 	dev_dbg(musb->controller, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
1250 			dma ? ", dma" : "");
1251 
1252 	/* check for errors */
1253 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1254 		/* dma was disabled, fifo flushed */
1255 		dev_dbg(musb->controller, "TX end %d stall\n", epnum);
1256 
1257 		/* stall; record URB status */
1258 		status = -EPIPE;
1259 
1260 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1261 		/* (NON-ISO) dma was disabled, fifo flushed */
1262 		dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum);
1263 
1264 		status = -ETIMEDOUT;
1265 
1266 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1267 		if (USB_ENDPOINT_XFER_BULK == qh->type && qh->mux == 1
1268 				&& !list_is_singular(&musb->out_bulk)) {
1269 			dev_dbg(musb->controller,
1270 				"NAK timeout on TX%d ep\n", epnum);
1271 			musb_bulk_nak_timeout(musb, hw_ep, 0);
1272 		} else {
1273 			dev_dbg(musb->controller,
1274 				"TX end=%d device not responding\n", epnum);
1275 			/* NOTE:  this code path would be a good place to PAUSE a
1276 			 * transfer, if there's some other (nonperiodic) tx urb
1277 			 * that could use this fifo.  (dma complicates it...)
1278 			 * That's already done for bulk RX transfers.
1279 			 *
1280 			 * if (bulk && qh->ring.next != &musb->out_bulk), then
1281 			 * we have a candidate... NAKing is *NOT* an error
1282 			 */
1283 			musb_ep_select(mbase, epnum);
1284 			musb_writew(epio, MUSB_TXCSR,
1285 					MUSB_TXCSR_H_WZC_BITS
1286 					| MUSB_TXCSR_TXPKTRDY);
1287 		}
1288 			return;
1289 	}
1290 
1291 done:
1292 	if (status) {
1293 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1294 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1295 			(void) musb->dma_controller->channel_abort(dma);
1296 		}
1297 
1298 		/* do the proper sequence to abort the transfer in the
1299 		 * usb core; the dma engine should already be stopped.
1300 		 */
1301 		musb_h_tx_flush_fifo(hw_ep);
1302 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1303 				| MUSB_TXCSR_DMAENAB
1304 				| MUSB_TXCSR_H_ERROR
1305 				| MUSB_TXCSR_H_RXSTALL
1306 				| MUSB_TXCSR_H_NAKTIMEOUT
1307 				);
1308 
1309 		musb_ep_select(mbase, epnum);
1310 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1311 		/* REVISIT may need to clear FLUSHFIFO ... */
1312 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1313 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1314 
1315 		done = true;
1316 	}
1317 
1318 	/* second cppi case */
1319 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1320 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1321 		return;
1322 	}
1323 
1324 	if (is_dma_capable() && dma && !status) {
1325 		/*
1326 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1327 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1328 		 * we can consider this transfer completed, lest we trash
1329 		 * its last packet when writing the next URB's data.  So we
1330 		 * switch back to mode 0 to get that interrupt; we'll come
1331 		 * back here once it happens.
1332 		 */
1333 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1334 			/*
1335 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1336 			 * clear them in a safe order.  That should be OK
1337 			 * once TXPKTRDY has been set (and I've never seen
1338 			 * it being 0 at this moment -- DMA interrupt latency
1339 			 * is significant) but if it hasn't been then we have
1340 			 * no choice but to stop being polite and ignore the
1341 			 * programmer's guide... :-)
1342 			 *
1343 			 * Note that we must write TXCSR with TXPKTRDY cleared
1344 			 * in order not to re-trigger the packet send (this bit
1345 			 * can't be cleared by CPU), and there's another caveat:
1346 			 * TXPKTRDY may be set shortly and then cleared in the
1347 			 * double-buffered FIFO mode, so we do an extra TXCSR
1348 			 * read for debouncing...
1349 			 */
1350 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1351 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1352 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1353 					    MUSB_TXCSR_TXPKTRDY);
1354 				musb_writew(epio, MUSB_TXCSR,
1355 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1356 			}
1357 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1358 				    MUSB_TXCSR_TXPKTRDY);
1359 			musb_writew(epio, MUSB_TXCSR,
1360 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1361 
1362 			/*
1363 			 * There is no guarantee that we'll get an interrupt
1364 			 * after clearing DMAMODE as we might have done this
1365 			 * too late (after TXPKTRDY was cleared by controller).
1366 			 * Re-read TXCSR as we have spoiled its previous value.
1367 			 */
1368 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1369 		}
1370 
1371 		/*
1372 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1373 		 * In any case, we must check the FIFO status here and bail out
1374 		 * only if the FIFO still has data -- that should prevent the
1375 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1376 		 * FIFO mode too...
1377 		 */
1378 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1379 			dev_dbg(musb->controller, "DMA complete but packet still in FIFO, "
1380 			    "CSR %04x\n", tx_csr);
1381 			return;
1382 		}
1383 	}
1384 
1385 	if (!status || dma || usb_pipeisoc(pipe)) {
1386 		if (dma)
1387 			length = dma->actual_len;
1388 		else
1389 			length = qh->segsize;
1390 		qh->offset += length;
1391 
1392 		if (usb_pipeisoc(pipe)) {
1393 			struct usb_iso_packet_descriptor	*d;
1394 
1395 			d = urb->iso_frame_desc + qh->iso_idx;
1396 			d->actual_length = length;
1397 			d->status = status;
1398 			if (++qh->iso_idx >= urb->number_of_packets) {
1399 				done = true;
1400 			} else {
1401 				d++;
1402 				offset = d->offset;
1403 				length = d->length;
1404 			}
1405 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1406 			done = true;
1407 		} else {
1408 			/* see if we need to send more data, or ZLP */
1409 			if (qh->segsize < qh->maxpacket)
1410 				done = true;
1411 			else if (qh->offset == urb->transfer_buffer_length
1412 					&& !(urb->transfer_flags
1413 						& URB_ZERO_PACKET))
1414 				done = true;
1415 			if (!done) {
1416 				offset = qh->offset;
1417 				length = urb->transfer_buffer_length - offset;
1418 				transfer_pending = true;
1419 			}
1420 		}
1421 	}
1422 
1423 	/* urb->status != -EINPROGRESS means request has been faulted,
1424 	 * so we must abort this transfer after cleanup
1425 	 */
1426 	if (urb->status != -EINPROGRESS) {
1427 		done = true;
1428 		if (status == 0)
1429 			status = urb->status;
1430 	}
1431 
1432 	if (done) {
1433 		/* set status */
1434 		urb->status = status;
1435 		urb->actual_length = qh->offset;
1436 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1437 		return;
1438 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1439 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1440 				offset, length)) {
1441 			if (is_cppi_enabled() || tusb_dma_omap())
1442 				musb_h_tx_dma_start(hw_ep);
1443 			return;
1444 		}
1445 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1446 		dev_dbg(musb->controller, "not complete, but DMA enabled?\n");
1447 		return;
1448 	}
1449 
1450 	/*
1451 	 * PIO: start next packet in this URB.
1452 	 *
1453 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1454 	 * (and presumably, FIFO is not half-full) we should write *two*
1455 	 * packets before updating TXCSR; other docs disagree...
1456 	 */
1457 	if (length > qh->maxpacket)
1458 		length = qh->maxpacket;
1459 	/* Unmap the buffer so that CPU can use it */
1460 	usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1461 
1462 	/*
1463 	 * We need to map sg if the transfer_buffer is
1464 	 * NULL.
1465 	 */
1466 	if (!urb->transfer_buffer)
1467 		qh->use_sg = true;
1468 
1469 	if (qh->use_sg) {
1470 		/* sg_miter_start is already done in musb_ep_program */
1471 		if (!sg_miter_next(&qh->sg_miter)) {
1472 			dev_err(musb->controller, "error: sg list empty\n");
1473 			sg_miter_stop(&qh->sg_miter);
1474 			status = -EINVAL;
1475 			goto done;
1476 		}
1477 		urb->transfer_buffer = qh->sg_miter.addr;
1478 		length = min_t(u32, length, qh->sg_miter.length);
1479 		musb_write_fifo(hw_ep, length, urb->transfer_buffer);
1480 		qh->sg_miter.consumed = length;
1481 		sg_miter_stop(&qh->sg_miter);
1482 	} else {
1483 		musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1484 	}
1485 
1486 	qh->segsize = length;
1487 
1488 	if (qh->use_sg) {
1489 		if (offset + length >= urb->transfer_buffer_length)
1490 			qh->use_sg = false;
1491 	}
1492 
1493 	musb_ep_select(mbase, epnum);
1494 	musb_writew(epio, MUSB_TXCSR,
1495 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1496 }
1497 
1498 
1499 #ifdef CONFIG_USB_INVENTRA_DMA
1500 
1501 /* Host side RX (IN) using Mentor DMA works as follows:
1502 	submit_urb ->
1503 		- if queue was empty, ProgramEndpoint
1504 		- first IN token is sent out (by setting ReqPkt)
1505 	LinuxIsr -> RxReady()
1506 	/\	=> first packet is received
1507 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1508 	|		-> DMA Isr (transfer complete) -> RxReady()
1509 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1510 	|		    - if urb not complete, send next IN token (ReqPkt)
1511 	|			   |		else complete urb.
1512 	|			   |
1513 	---------------------------
1514  *
1515  * Nuances of mode 1:
1516  *	For short packets, no ack (+RxPktRdy) is sent automatically
1517  *	(even if AutoClear is ON)
1518  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1519  *	automatically => major problem, as collecting the next packet becomes
1520  *	difficult. Hence mode 1 is not used.
1521  *
1522  * REVISIT
1523  *	All we care about at this driver level is that
1524  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1525  *       (b) termination conditions are: short RX, or buffer full;
1526  *       (c) fault modes include
1527  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1528  *             (and that endpoint's dma queue stops immediately)
1529  *           - overflow (full, PLUS more bytes in the terminal packet)
1530  *
1531  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1532  *	thus be a great candidate for using mode 1 ... for all but the
1533  *	last packet of one URB's transfer.
1534  */
1535 
1536 #endif
1537 
1538 /*
1539  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1540  * and high-bandwidth IN transfer cases.
1541  */
1542 void musb_host_rx(struct musb *musb, u8 epnum)
1543 {
1544 	struct urb		*urb;
1545 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1546 	void __iomem		*epio = hw_ep->regs;
1547 	struct musb_qh		*qh = hw_ep->in_qh;
1548 	size_t			xfer_len;
1549 	void __iomem		*mbase = musb->mregs;
1550 	int			pipe;
1551 	u16			rx_csr, val;
1552 	bool			iso_err = false;
1553 	bool			done = false;
1554 	u32			status;
1555 	struct dma_channel	*dma;
1556 	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
1557 
1558 	musb_ep_select(mbase, epnum);
1559 
1560 	urb = next_urb(qh);
1561 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1562 	status = 0;
1563 	xfer_len = 0;
1564 
1565 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1566 	val = rx_csr;
1567 
1568 	if (unlikely(!urb)) {
1569 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1570 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1571 		 * with fifo full.  (Only with DMA??)
1572 		 */
1573 		dev_dbg(musb->controller, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
1574 			musb_readw(epio, MUSB_RXCOUNT));
1575 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1576 		return;
1577 	}
1578 
1579 	pipe = urb->pipe;
1580 
1581 	dev_dbg(musb->controller, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
1582 		epnum, rx_csr, urb->actual_length,
1583 		dma ? dma->actual_len : 0);
1584 
1585 	/* check for errors, concurrent stall & unlink is not really
1586 	 * handled yet! */
1587 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1588 		dev_dbg(musb->controller, "RX end %d STALL\n", epnum);
1589 
1590 		/* stall; record URB status */
1591 		status = -EPIPE;
1592 
1593 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1594 		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
1595 
1596 		status = -EPROTO;
1597 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1598 
1599 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1600 
1601 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1602 			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
1603 
1604 			/* NOTE: NAKing is *NOT* an error, so we want to
1605 			 * continue.  Except ... if there's a request for
1606 			 * another QH, use that instead of starving it.
1607 			 *
1608 			 * Devices like Ethernet and serial adapters keep
1609 			 * reads posted at all times, which will starve
1610 			 * other devices without this logic.
1611 			 */
1612 			if (usb_pipebulk(urb->pipe)
1613 					&& qh->mux == 1
1614 					&& !list_is_singular(&musb->in_bulk)) {
1615 				musb_bulk_nak_timeout(musb, hw_ep, 1);
1616 				return;
1617 			}
1618 			musb_ep_select(mbase, epnum);
1619 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1620 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1621 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1622 
1623 			goto finish;
1624 		} else {
1625 			dev_dbg(musb->controller, "RX end %d ISO data error\n", epnum);
1626 			/* packet error reported later */
1627 			iso_err = true;
1628 		}
1629 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1630 		dev_dbg(musb->controller, "end %d high bandwidth incomplete ISO packet RX\n",
1631 				epnum);
1632 		status = -EPROTO;
1633 	}
1634 
1635 	/* faults abort the transfer */
1636 	if (status) {
1637 		/* clean up dma and collect transfer count */
1638 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1639 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1640 			(void) musb->dma_controller->channel_abort(dma);
1641 			xfer_len = dma->actual_len;
1642 		}
1643 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1644 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1645 		done = true;
1646 		goto finish;
1647 	}
1648 
1649 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1650 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1651 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1652 		goto finish;
1653 	}
1654 
1655 	/* thorough shutdown for now ... given more precise fault handling
1656 	 * and better queueing support, we might keep a DMA pipeline going
1657 	 * while processing this irq for earlier completions.
1658 	 */
1659 
1660 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1661 
1662 #if !defined(CONFIG_USB_INVENTRA_DMA) && !defined(CONFIG_USB_UX500_DMA)
1663 	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
1664 		/* REVISIT this happened for a while on some short reads...
1665 		 * the cleanup still needs investigation... looks bad...
1666 		 * and also duplicates dma cleanup code above ... plus,
1667 		 * shouldn't this be the "half full" double buffer case?
1668 		 */
1669 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1670 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1671 			(void) musb->dma_controller->channel_abort(dma);
1672 			xfer_len = dma->actual_len;
1673 			done = true;
1674 		}
1675 
1676 		dev_dbg(musb->controller, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
1677 				xfer_len, dma ? ", dma" : "");
1678 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1679 
1680 		musb_ep_select(mbase, epnum);
1681 		musb_writew(epio, MUSB_RXCSR,
1682 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1683 	}
1684 #endif
1685 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1686 		xfer_len = dma->actual_len;
1687 
1688 		val &= ~(MUSB_RXCSR_DMAENAB
1689 			| MUSB_RXCSR_H_AUTOREQ
1690 			| MUSB_RXCSR_AUTOCLEAR
1691 			| MUSB_RXCSR_RXPKTRDY);
1692 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1693 
1694 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
1695 		if (usb_pipeisoc(pipe)) {
1696 			struct usb_iso_packet_descriptor *d;
1697 
1698 			d = urb->iso_frame_desc + qh->iso_idx;
1699 			d->actual_length = xfer_len;
1700 
1701 			/* even if there was an error, we did the dma
1702 			 * for iso_frame_desc->length
1703 			 */
1704 			if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1705 				d->status = 0;
1706 
1707 			if (++qh->iso_idx >= urb->number_of_packets)
1708 				done = true;
1709 			else
1710 				done = false;
1711 
1712 		} else  {
1713 		/* done if urb buffer is full or short packet is recd */
1714 		done = (urb->actual_length + xfer_len >=
1715 				urb->transfer_buffer_length
1716 			|| dma->actual_len < qh->maxpacket);
1717 		}
1718 
1719 		/* send IN token for next packet, without AUTOREQ */
1720 		if (!done) {
1721 			val |= MUSB_RXCSR_H_REQPKT;
1722 			musb_writew(epio, MUSB_RXCSR,
1723 				MUSB_RXCSR_H_WZC_BITS | val);
1724 		}
1725 
1726 		dev_dbg(musb->controller, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
1727 			done ? "off" : "reset",
1728 			musb_readw(epio, MUSB_RXCSR),
1729 			musb_readw(epio, MUSB_RXCOUNT));
1730 #else
1731 		done = true;
1732 #endif
1733 	} else if (urb->status == -EINPROGRESS) {
1734 		/* if no errors, be sure a packet is ready for unloading */
1735 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1736 			status = -EPROTO;
1737 			ERR("Rx interrupt with no errors or packet!\n");
1738 
1739 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1740 
1741 /* SCRUB (RX) */
1742 			/* do the proper sequence to abort the transfer */
1743 			musb_ep_select(mbase, epnum);
1744 			val &= ~MUSB_RXCSR_H_REQPKT;
1745 			musb_writew(epio, MUSB_RXCSR, val);
1746 			goto finish;
1747 		}
1748 
1749 		/* we are expecting IN packets */
1750 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
1751 		if (dma) {
1752 			struct dma_controller	*c;
1753 			u16			rx_count;
1754 			int			ret, length;
1755 			dma_addr_t		buf;
1756 
1757 			rx_count = musb_readw(epio, MUSB_RXCOUNT);
1758 
1759 			dev_dbg(musb->controller, "RX%d count %d, buffer 0x%llx len %d/%d\n",
1760 					epnum, rx_count,
1761 					(unsigned long long) urb->transfer_dma
1762 					+ urb->actual_length,
1763 					qh->offset,
1764 					urb->transfer_buffer_length);
1765 
1766 			c = musb->dma_controller;
1767 
1768 			if (usb_pipeisoc(pipe)) {
1769 				int d_status = 0;
1770 				struct usb_iso_packet_descriptor *d;
1771 
1772 				d = urb->iso_frame_desc + qh->iso_idx;
1773 
1774 				if (iso_err) {
1775 					d_status = -EILSEQ;
1776 					urb->error_count++;
1777 				}
1778 				if (rx_count > d->length) {
1779 					if (d_status == 0) {
1780 						d_status = -EOVERFLOW;
1781 						urb->error_count++;
1782 					}
1783 					dev_dbg(musb->controller, "** OVERFLOW %d into %d\n",\
1784 					    rx_count, d->length);
1785 
1786 					length = d->length;
1787 				} else
1788 					length = rx_count;
1789 				d->status = d_status;
1790 				buf = urb->transfer_dma + d->offset;
1791 			} else {
1792 				length = rx_count;
1793 				buf = urb->transfer_dma +
1794 						urb->actual_length;
1795 			}
1796 
1797 			dma->desired_mode = 0;
1798 #ifdef USE_MODE1
1799 			/* because of the issue below, mode 1 will
1800 			 * only rarely behave with correct semantics.
1801 			 */
1802 			if ((urb->transfer_flags &
1803 						URB_SHORT_NOT_OK)
1804 				&& (urb->transfer_buffer_length -
1805 						urb->actual_length)
1806 					> qh->maxpacket)
1807 				dma->desired_mode = 1;
1808 			if (rx_count < hw_ep->max_packet_sz_rx) {
1809 				length = rx_count;
1810 				dma->desired_mode = 0;
1811 			} else {
1812 				length = urb->transfer_buffer_length;
1813 			}
1814 #endif
1815 
1816 /* Disadvantage of using mode 1:
1817  *	It's basically usable only for mass storage class; essentially all
1818  *	other protocols also terminate transfers on short packets.
1819  *
1820  * Details:
1821  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1822  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1823  *	to use the extra IN token to grab the last packet using mode 0, then
1824  *	the problem is that you cannot be sure when the device will send the
1825  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1826  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1827  *	transfer, while sometimes it is recd just a little late so that if you
1828  *	try to configure for mode 0 soon after the mode 1 transfer is
1829  *	completed, you will find rxcount 0. Okay, so you might think why not
1830  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1831  */
1832 
1833 			val = musb_readw(epio, MUSB_RXCSR);
1834 			val &= ~MUSB_RXCSR_H_REQPKT;
1835 
1836 			if (dma->desired_mode == 0)
1837 				val &= ~MUSB_RXCSR_H_AUTOREQ;
1838 			else
1839 				val |= MUSB_RXCSR_H_AUTOREQ;
1840 			val |= MUSB_RXCSR_DMAENAB;
1841 
1842 			/* autoclear shouldn't be set in high bandwidth */
1843 			if (qh->hb_mult == 1)
1844 				val |= MUSB_RXCSR_AUTOCLEAR;
1845 
1846 			musb_writew(epio, MUSB_RXCSR,
1847 				MUSB_RXCSR_H_WZC_BITS | val);
1848 
1849 			/* REVISIT if when actual_length != 0,
1850 			 * transfer_buffer_length needs to be
1851 			 * adjusted first...
1852 			 */
1853 			ret = c->channel_program(
1854 				dma, qh->maxpacket,
1855 				dma->desired_mode, buf, length);
1856 
1857 			if (!ret) {
1858 				c->channel_release(dma);
1859 				hw_ep->rx_channel = NULL;
1860 				dma = NULL;
1861 				val = musb_readw(epio, MUSB_RXCSR);
1862 				val &= ~(MUSB_RXCSR_DMAENAB
1863 					| MUSB_RXCSR_H_AUTOREQ
1864 					| MUSB_RXCSR_AUTOCLEAR);
1865 				musb_writew(epio, MUSB_RXCSR, val);
1866 			}
1867 		}
1868 #endif	/* Mentor DMA */
1869 
1870 		if (!dma) {
1871 			unsigned int received_len;
1872 
1873 			/* Unmap the buffer so that CPU can use it */
1874 			usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1875 
1876 			/*
1877 			 * We need to map sg if the transfer_buffer is
1878 			 * NULL.
1879 			 */
1880 			if (!urb->transfer_buffer) {
1881 				qh->use_sg = true;
1882 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
1883 						sg_flags);
1884 			}
1885 
1886 			if (qh->use_sg) {
1887 				if (!sg_miter_next(&qh->sg_miter)) {
1888 					dev_err(musb->controller, "error: sg list empty\n");
1889 					sg_miter_stop(&qh->sg_miter);
1890 					status = -EINVAL;
1891 					done = true;
1892 					goto finish;
1893 				}
1894 				urb->transfer_buffer = qh->sg_miter.addr;
1895 				received_len = urb->actual_length;
1896 				qh->offset = 0x0;
1897 				done = musb_host_packet_rx(musb, urb, epnum,
1898 						iso_err);
1899 				/* Calculate the number of bytes received */
1900 				received_len = urb->actual_length -
1901 					received_len;
1902 				qh->sg_miter.consumed = received_len;
1903 				sg_miter_stop(&qh->sg_miter);
1904 			} else {
1905 				done = musb_host_packet_rx(musb, urb,
1906 						epnum, iso_err);
1907 			}
1908 			dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
1909 		}
1910 	}
1911 
1912 finish:
1913 	urb->actual_length += xfer_len;
1914 	qh->offset += xfer_len;
1915 	if (done) {
1916 		if (qh->use_sg)
1917 			qh->use_sg = false;
1918 
1919 		if (urb->status == -EINPROGRESS)
1920 			urb->status = status;
1921 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1922 	}
1923 }
1924 
1925 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1926  * the software schedule associates multiple such nodes with a given
1927  * host side hardware endpoint + direction; scheduling may activate
1928  * that hardware endpoint.
1929  */
1930 static int musb_schedule(
1931 	struct musb		*musb,
1932 	struct musb_qh		*qh,
1933 	int			is_in)
1934 {
1935 	int			idle;
1936 	int			best_diff;
1937 	int			best_end, epnum;
1938 	struct musb_hw_ep	*hw_ep = NULL;
1939 	struct list_head	*head = NULL;
1940 	u8			toggle;
1941 	u8			txtype;
1942 	struct urb		*urb = next_urb(qh);
1943 
1944 	/* use fixed hardware for control and bulk */
1945 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1946 		head = &musb->control;
1947 		hw_ep = musb->control_ep;
1948 		goto success;
1949 	}
1950 
1951 	/* else, periodic transfers get muxed to other endpoints */
1952 
1953 	/*
1954 	 * We know this qh hasn't been scheduled, so all we need to do
1955 	 * is choose which hardware endpoint to put it on ...
1956 	 *
1957 	 * REVISIT what we really want here is a regular schedule tree
1958 	 * like e.g. OHCI uses.
1959 	 */
1960 	best_diff = 4096;
1961 	best_end = -1;
1962 
1963 	for (epnum = 1, hw_ep = musb->endpoints + 1;
1964 			epnum < musb->nr_endpoints;
1965 			epnum++, hw_ep++) {
1966 		int	diff;
1967 
1968 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
1969 			continue;
1970 
1971 		if (hw_ep == musb->bulk_ep)
1972 			continue;
1973 
1974 		if (is_in)
1975 			diff = hw_ep->max_packet_sz_rx;
1976 		else
1977 			diff = hw_ep->max_packet_sz_tx;
1978 		diff -= (qh->maxpacket * qh->hb_mult);
1979 
1980 		if (diff >= 0 && best_diff > diff) {
1981 
1982 			/*
1983 			 * Mentor controller has a bug in that if we schedule
1984 			 * a BULK Tx transfer on an endpoint that had earlier
1985 			 * handled ISOC then the BULK transfer has to start on
1986 			 * a zero toggle.  If the BULK transfer starts on a 1
1987 			 * toggle then this transfer will fail as the mentor
1988 			 * controller starts the Bulk transfer on a 0 toggle
1989 			 * irrespective of the programming of the toggle bits
1990 			 * in the TXCSR register.  Check for this condition
1991 			 * while allocating the EP for a Tx Bulk transfer.  If
1992 			 * so skip this EP.
1993 			 */
1994 			hw_ep = musb->endpoints + epnum;
1995 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
1996 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
1997 					>> 4) & 0x3;
1998 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
1999 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
2000 				continue;
2001 
2002 			best_diff = diff;
2003 			best_end = epnum;
2004 		}
2005 	}
2006 	/* use bulk reserved ep1 if no other ep is free */
2007 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
2008 		hw_ep = musb->bulk_ep;
2009 		if (is_in)
2010 			head = &musb->in_bulk;
2011 		else
2012 			head = &musb->out_bulk;
2013 
2014 		/* Enable bulk RX/TX NAK timeout scheme when bulk requests are
2015 		 * multiplexed. This scheme does not work in high speed to full
2016 		 * speed scenario as NAK interrupts are not coming from a
2017 		 * full speed device connected to a high speed device.
2018 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
2019 		 * 4 (8 frame or 8ms) for FS device.
2020 		 */
2021 		if (qh->dev)
2022 			qh->intv_reg =
2023 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
2024 		goto success;
2025 	} else if (best_end < 0) {
2026 		return -ENOSPC;
2027 	}
2028 
2029 	idle = 1;
2030 	qh->mux = 0;
2031 	hw_ep = musb->endpoints + best_end;
2032 	dev_dbg(musb->controller, "qh %p periodic slot %d\n", qh, best_end);
2033 success:
2034 	if (head) {
2035 		idle = list_empty(head);
2036 		list_add_tail(&qh->ring, head);
2037 		qh->mux = 1;
2038 	}
2039 	qh->hw_ep = hw_ep;
2040 	qh->hep->hcpriv = qh;
2041 	if (idle)
2042 		musb_start_urb(musb, is_in, qh);
2043 	return 0;
2044 }
2045 
2046 static int musb_urb_enqueue(
2047 	struct usb_hcd			*hcd,
2048 	struct urb			*urb,
2049 	gfp_t				mem_flags)
2050 {
2051 	unsigned long			flags;
2052 	struct musb			*musb = hcd_to_musb(hcd);
2053 	struct usb_host_endpoint	*hep = urb->ep;
2054 	struct musb_qh			*qh;
2055 	struct usb_endpoint_descriptor	*epd = &hep->desc;
2056 	int				ret;
2057 	unsigned			type_reg;
2058 	unsigned			interval;
2059 
2060 	/* host role must be active */
2061 	if (!is_host_active(musb) || !musb->is_active)
2062 		return -ENODEV;
2063 
2064 	spin_lock_irqsave(&musb->lock, flags);
2065 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
2066 	qh = ret ? NULL : hep->hcpriv;
2067 	if (qh)
2068 		urb->hcpriv = qh;
2069 	spin_unlock_irqrestore(&musb->lock, flags);
2070 
2071 	/* DMA mapping was already done, if needed, and this urb is on
2072 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
2073 	 * scheduled onto a live qh.
2074 	 *
2075 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
2076 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
2077 	 * except for the first urb queued after a config change.
2078 	 */
2079 	if (qh || ret)
2080 		return ret;
2081 
2082 	/* Allocate and initialize qh, minimizing the work done each time
2083 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
2084 	 *
2085 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
2086 	 * for bugs in other kernel code to break this driver...
2087 	 */
2088 	qh = kzalloc(sizeof *qh, mem_flags);
2089 	if (!qh) {
2090 		spin_lock_irqsave(&musb->lock, flags);
2091 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2092 		spin_unlock_irqrestore(&musb->lock, flags);
2093 		return -ENOMEM;
2094 	}
2095 
2096 	qh->hep = hep;
2097 	qh->dev = urb->dev;
2098 	INIT_LIST_HEAD(&qh->ring);
2099 	qh->is_ready = 1;
2100 
2101 	qh->maxpacket = usb_endpoint_maxp(epd);
2102 	qh->type = usb_endpoint_type(epd);
2103 
2104 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
2105 	 * Some musb cores don't support high bandwidth ISO transfers; and
2106 	 * we don't (yet!) support high bandwidth interrupt transfers.
2107 	 */
2108 	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
2109 	if (qh->hb_mult > 1) {
2110 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
2111 
2112 		if (ok)
2113 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
2114 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
2115 		if (!ok) {
2116 			ret = -EMSGSIZE;
2117 			goto done;
2118 		}
2119 		qh->maxpacket &= 0x7ff;
2120 	}
2121 
2122 	qh->epnum = usb_endpoint_num(epd);
2123 
2124 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
2125 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
2126 
2127 	/* precompute rxtype/txtype/type0 register */
2128 	type_reg = (qh->type << 4) | qh->epnum;
2129 	switch (urb->dev->speed) {
2130 	case USB_SPEED_LOW:
2131 		type_reg |= 0xc0;
2132 		break;
2133 	case USB_SPEED_FULL:
2134 		type_reg |= 0x80;
2135 		break;
2136 	default:
2137 		type_reg |= 0x40;
2138 	}
2139 	qh->type_reg = type_reg;
2140 
2141 	/* Precompute RXINTERVAL/TXINTERVAL register */
2142 	switch (qh->type) {
2143 	case USB_ENDPOINT_XFER_INT:
2144 		/*
2145 		 * Full/low speeds use the  linear encoding,
2146 		 * high speed uses the logarithmic encoding.
2147 		 */
2148 		if (urb->dev->speed <= USB_SPEED_FULL) {
2149 			interval = max_t(u8, epd->bInterval, 1);
2150 			break;
2151 		}
2152 		/* FALLTHROUGH */
2153 	case USB_ENDPOINT_XFER_ISOC:
2154 		/* ISO always uses logarithmic encoding */
2155 		interval = min_t(u8, epd->bInterval, 16);
2156 		break;
2157 	default:
2158 		/* REVISIT we actually want to use NAK limits, hinting to the
2159 		 * transfer scheduling logic to try some other qh, e.g. try
2160 		 * for 2 msec first:
2161 		 *
2162 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2163 		 *
2164 		 * The downside of disabling this is that transfer scheduling
2165 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2166 		 * peripheral could make that hurt.  That's perfectly normal
2167 		 * for reads from network or serial adapters ... so we have
2168 		 * partial NAKlimit support for bulk RX.
2169 		 *
2170 		 * The upside of disabling it is simpler transfer scheduling.
2171 		 */
2172 		interval = 0;
2173 	}
2174 	qh->intv_reg = interval;
2175 
2176 	/* precompute addressing for external hub/tt ports */
2177 	if (musb->is_multipoint) {
2178 		struct usb_device	*parent = urb->dev->parent;
2179 
2180 		if (parent != hcd->self.root_hub) {
2181 			qh->h_addr_reg = (u8) parent->devnum;
2182 
2183 			/* set up tt info if needed */
2184 			if (urb->dev->tt) {
2185 				qh->h_port_reg = (u8) urb->dev->ttport;
2186 				if (urb->dev->tt->hub)
2187 					qh->h_addr_reg =
2188 						(u8) urb->dev->tt->hub->devnum;
2189 				if (urb->dev->tt->multi)
2190 					qh->h_addr_reg |= 0x80;
2191 			}
2192 		}
2193 	}
2194 
2195 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2196 	 * until we get real dma queues (with an entry for each urb/buffer),
2197 	 * we only have work to do in the former case.
2198 	 */
2199 	spin_lock_irqsave(&musb->lock, flags);
2200 	if (hep->hcpriv || !next_urb(qh)) {
2201 		/* some concurrent activity submitted another urb to hep...
2202 		 * odd, rare, error prone, but legal.
2203 		 */
2204 		kfree(qh);
2205 		qh = NULL;
2206 		ret = 0;
2207 	} else
2208 		ret = musb_schedule(musb, qh,
2209 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2210 
2211 	if (ret == 0) {
2212 		urb->hcpriv = qh;
2213 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2214 		 * musb_start_urb(), but otherwise only konicawc cares ...
2215 		 */
2216 	}
2217 	spin_unlock_irqrestore(&musb->lock, flags);
2218 
2219 done:
2220 	if (ret != 0) {
2221 		spin_lock_irqsave(&musb->lock, flags);
2222 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2223 		spin_unlock_irqrestore(&musb->lock, flags);
2224 		kfree(qh);
2225 	}
2226 	return ret;
2227 }
2228 
2229 
2230 /*
2231  * abort a transfer that's at the head of a hardware queue.
2232  * called with controller locked, irqs blocked
2233  * that hardware queue advances to the next transfer, unless prevented
2234  */
2235 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2236 {
2237 	struct musb_hw_ep	*ep = qh->hw_ep;
2238 	struct musb		*musb = ep->musb;
2239 	void __iomem		*epio = ep->regs;
2240 	unsigned		hw_end = ep->epnum;
2241 	void __iomem		*regs = ep->musb->mregs;
2242 	int			is_in = usb_pipein(urb->pipe);
2243 	int			status = 0;
2244 	u16			csr;
2245 
2246 	musb_ep_select(regs, hw_end);
2247 
2248 	if (is_dma_capable()) {
2249 		struct dma_channel	*dma;
2250 
2251 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2252 		if (dma) {
2253 			status = ep->musb->dma_controller->channel_abort(dma);
2254 			dev_dbg(musb->controller,
2255 				"abort %cX%d DMA for urb %p --> %d\n",
2256 				is_in ? 'R' : 'T', ep->epnum,
2257 				urb, status);
2258 			urb->actual_length += dma->actual_len;
2259 		}
2260 	}
2261 
2262 	/* turn off DMA requests, discard state, stop polling ... */
2263 	if (ep->epnum && is_in) {
2264 		/* giveback saves bulk toggle */
2265 		csr = musb_h_flush_rxfifo(ep, 0);
2266 
2267 		/* REVISIT we still get an irq; should likely clear the
2268 		 * endpoint's irq status here to avoid bogus irqs.
2269 		 * clearing that status is platform-specific...
2270 		 */
2271 	} else if (ep->epnum) {
2272 		musb_h_tx_flush_fifo(ep);
2273 		csr = musb_readw(epio, MUSB_TXCSR);
2274 		csr &= ~(MUSB_TXCSR_AUTOSET
2275 			| MUSB_TXCSR_DMAENAB
2276 			| MUSB_TXCSR_H_RXSTALL
2277 			| MUSB_TXCSR_H_NAKTIMEOUT
2278 			| MUSB_TXCSR_H_ERROR
2279 			| MUSB_TXCSR_TXPKTRDY);
2280 		musb_writew(epio, MUSB_TXCSR, csr);
2281 		/* REVISIT may need to clear FLUSHFIFO ... */
2282 		musb_writew(epio, MUSB_TXCSR, csr);
2283 		/* flush cpu writebuffer */
2284 		csr = musb_readw(epio, MUSB_TXCSR);
2285 	} else  {
2286 		musb_h_ep0_flush_fifo(ep);
2287 	}
2288 	if (status == 0)
2289 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2290 	return status;
2291 }
2292 
2293 static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
2294 {
2295 	struct musb		*musb = hcd_to_musb(hcd);
2296 	struct musb_qh		*qh;
2297 	unsigned long		flags;
2298 	int			is_in  = usb_pipein(urb->pipe);
2299 	int			ret;
2300 
2301 	dev_dbg(musb->controller, "urb=%p, dev%d ep%d%s\n", urb,
2302 			usb_pipedevice(urb->pipe),
2303 			usb_pipeendpoint(urb->pipe),
2304 			is_in ? "in" : "out");
2305 
2306 	spin_lock_irqsave(&musb->lock, flags);
2307 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2308 	if (ret)
2309 		goto done;
2310 
2311 	qh = urb->hcpriv;
2312 	if (!qh)
2313 		goto done;
2314 
2315 	/*
2316 	 * Any URB not actively programmed into endpoint hardware can be
2317 	 * immediately given back; that's any URB not at the head of an
2318 	 * endpoint queue, unless someday we get real DMA queues.  And even
2319 	 * if it's at the head, it might not be known to the hardware...
2320 	 *
2321 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2322 	 * has already been updated.  This is a synchronous abort; it'd be
2323 	 * OK to hold off until after some IRQ, though.
2324 	 *
2325 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2326 	 */
2327 	if (!qh->is_ready
2328 			|| urb->urb_list.prev != &qh->hep->urb_list
2329 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2330 		int	ready = qh->is_ready;
2331 
2332 		qh->is_ready = 0;
2333 		musb_giveback(musb, urb, 0);
2334 		qh->is_ready = ready;
2335 
2336 		/* If nothing else (usually musb_giveback) is using it
2337 		 * and its URB list has emptied, recycle this qh.
2338 		 */
2339 		if (ready && list_empty(&qh->hep->urb_list)) {
2340 			qh->hep->hcpriv = NULL;
2341 			list_del(&qh->ring);
2342 			kfree(qh);
2343 		}
2344 	} else
2345 		ret = musb_cleanup_urb(urb, qh);
2346 done:
2347 	spin_unlock_irqrestore(&musb->lock, flags);
2348 	return ret;
2349 }
2350 
2351 /* disable an endpoint */
2352 static void
2353 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2354 {
2355 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2356 	unsigned long		flags;
2357 	struct musb		*musb = hcd_to_musb(hcd);
2358 	struct musb_qh		*qh;
2359 	struct urb		*urb;
2360 
2361 	spin_lock_irqsave(&musb->lock, flags);
2362 
2363 	qh = hep->hcpriv;
2364 	if (qh == NULL)
2365 		goto exit;
2366 
2367 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2368 
2369 	/* Kick the first URB off the hardware, if needed */
2370 	qh->is_ready = 0;
2371 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2372 		urb = next_urb(qh);
2373 
2374 		/* make software (then hardware) stop ASAP */
2375 		if (!urb->unlinked)
2376 			urb->status = -ESHUTDOWN;
2377 
2378 		/* cleanup */
2379 		musb_cleanup_urb(urb, qh);
2380 
2381 		/* Then nuke all the others ... and advance the
2382 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2383 		 */
2384 		while (!list_empty(&hep->urb_list)) {
2385 			urb = next_urb(qh);
2386 			urb->status = -ESHUTDOWN;
2387 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2388 		}
2389 	} else {
2390 		/* Just empty the queue; the hardware is busy with
2391 		 * other transfers, and since !qh->is_ready nothing
2392 		 * will activate any of these as it advances.
2393 		 */
2394 		while (!list_empty(&hep->urb_list))
2395 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2396 
2397 		hep->hcpriv = NULL;
2398 		list_del(&qh->ring);
2399 		kfree(qh);
2400 	}
2401 exit:
2402 	spin_unlock_irqrestore(&musb->lock, flags);
2403 }
2404 
2405 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2406 {
2407 	struct musb	*musb = hcd_to_musb(hcd);
2408 
2409 	return musb_readw(musb->mregs, MUSB_FRAME);
2410 }
2411 
2412 static int musb_h_start(struct usb_hcd *hcd)
2413 {
2414 	struct musb	*musb = hcd_to_musb(hcd);
2415 
2416 	/* NOTE: musb_start() is called when the hub driver turns
2417 	 * on port power, or when (OTG) peripheral starts.
2418 	 */
2419 	hcd->state = HC_STATE_RUNNING;
2420 	musb->port1_status = 0;
2421 	return 0;
2422 }
2423 
2424 static void musb_h_stop(struct usb_hcd *hcd)
2425 {
2426 	musb_stop(hcd_to_musb(hcd));
2427 	hcd->state = HC_STATE_HALT;
2428 }
2429 
2430 static int musb_bus_suspend(struct usb_hcd *hcd)
2431 {
2432 	struct musb	*musb = hcd_to_musb(hcd);
2433 	u8		devctl;
2434 
2435 	musb_port_suspend(musb, true);
2436 
2437 	if (!is_host_active(musb))
2438 		return 0;
2439 
2440 	switch (musb->xceiv->state) {
2441 	case OTG_STATE_A_SUSPEND:
2442 		return 0;
2443 	case OTG_STATE_A_WAIT_VRISE:
2444 		/* ID could be grounded even if there's no device
2445 		 * on the other end of the cable.  NOTE that the
2446 		 * A_WAIT_VRISE timers are messy with MUSB...
2447 		 */
2448 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2449 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2450 			musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2451 		break;
2452 	default:
2453 		break;
2454 	}
2455 
2456 	if (musb->is_active) {
2457 		WARNING("trying to suspend as %s while active\n",
2458 				usb_otg_state_string(musb->xceiv->state));
2459 		return -EBUSY;
2460 	} else
2461 		return 0;
2462 }
2463 
2464 static int musb_bus_resume(struct usb_hcd *hcd)
2465 {
2466 	struct musb *musb = hcd_to_musb(hcd);
2467 
2468 	if (musb->config &&
2469 	    musb->config->host_port_deassert_reset_at_resume)
2470 		musb_port_reset(musb, false);
2471 
2472 	return 0;
2473 }
2474 
2475 #ifndef CONFIG_MUSB_PIO_ONLY
2476 
2477 #define MUSB_USB_DMA_ALIGN 4
2478 
2479 struct musb_temp_buffer {
2480 	void *kmalloc_ptr;
2481 	void *old_xfer_buffer;
2482 	u8 data[0];
2483 };
2484 
2485 static void musb_free_temp_buffer(struct urb *urb)
2486 {
2487 	enum dma_data_direction dir;
2488 	struct musb_temp_buffer *temp;
2489 
2490 	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
2491 		return;
2492 
2493 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2494 
2495 	temp = container_of(urb->transfer_buffer, struct musb_temp_buffer,
2496 			    data);
2497 
2498 	if (dir == DMA_FROM_DEVICE) {
2499 		memcpy(temp->old_xfer_buffer, temp->data,
2500 		       urb->transfer_buffer_length);
2501 	}
2502 	urb->transfer_buffer = temp->old_xfer_buffer;
2503 	kfree(temp->kmalloc_ptr);
2504 
2505 	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
2506 }
2507 
2508 static int musb_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
2509 {
2510 	enum dma_data_direction dir;
2511 	struct musb_temp_buffer *temp;
2512 	void *kmalloc_ptr;
2513 	size_t kmalloc_size;
2514 
2515 	if (urb->num_sgs || urb->sg ||
2516 	    urb->transfer_buffer_length == 0 ||
2517 	    !((uintptr_t)urb->transfer_buffer & (MUSB_USB_DMA_ALIGN - 1)))
2518 		return 0;
2519 
2520 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2521 
2522 	/* Allocate a buffer with enough padding for alignment */
2523 	kmalloc_size = urb->transfer_buffer_length +
2524 		sizeof(struct musb_temp_buffer) + MUSB_USB_DMA_ALIGN - 1;
2525 
2526 	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
2527 	if (!kmalloc_ptr)
2528 		return -ENOMEM;
2529 
2530 	/* Position our struct temp_buffer such that data is aligned */
2531 	temp = PTR_ALIGN(kmalloc_ptr, MUSB_USB_DMA_ALIGN);
2532 
2533 
2534 	temp->kmalloc_ptr = kmalloc_ptr;
2535 	temp->old_xfer_buffer = urb->transfer_buffer;
2536 	if (dir == DMA_TO_DEVICE)
2537 		memcpy(temp->data, urb->transfer_buffer,
2538 		       urb->transfer_buffer_length);
2539 	urb->transfer_buffer = temp->data;
2540 
2541 	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
2542 
2543 	return 0;
2544 }
2545 
2546 static int musb_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
2547 				      gfp_t mem_flags)
2548 {
2549 	struct musb	*musb = hcd_to_musb(hcd);
2550 	int ret;
2551 
2552 	/*
2553 	 * The DMA engine in RTL1.8 and above cannot handle
2554 	 * DMA addresses that are not aligned to a 4 byte boundary.
2555 	 * For such engine implemented (un)map_urb_for_dma hooks.
2556 	 * Do not use these hooks for RTL<1.8
2557 	 */
2558 	if (musb->hwvers < MUSB_HWVERS_1800)
2559 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2560 
2561 	ret = musb_alloc_temp_buffer(urb, mem_flags);
2562 	if (ret)
2563 		return ret;
2564 
2565 	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2566 	if (ret)
2567 		musb_free_temp_buffer(urb);
2568 
2569 	return ret;
2570 }
2571 
2572 static void musb_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
2573 {
2574 	struct musb	*musb = hcd_to_musb(hcd);
2575 
2576 	usb_hcd_unmap_urb_for_dma(hcd, urb);
2577 
2578 	/* Do not use this hook for RTL<1.8 (see description above) */
2579 	if (musb->hwvers < MUSB_HWVERS_1800)
2580 		return;
2581 
2582 	musb_free_temp_buffer(urb);
2583 }
2584 #endif /* !CONFIG_MUSB_PIO_ONLY */
2585 
2586 static const struct hc_driver musb_hc_driver = {
2587 	.description		= "musb-hcd",
2588 	.product_desc		= "MUSB HDRC host driver",
2589 	.hcd_priv_size		= sizeof(struct musb *),
2590 	.flags			= HCD_USB2 | HCD_MEMORY,
2591 
2592 	/* not using irq handler or reset hooks from usbcore, since
2593 	 * those must be shared with peripheral code for OTG configs
2594 	 */
2595 
2596 	.start			= musb_h_start,
2597 	.stop			= musb_h_stop,
2598 
2599 	.get_frame_number	= musb_h_get_frame_number,
2600 
2601 	.urb_enqueue		= musb_urb_enqueue,
2602 	.urb_dequeue		= musb_urb_dequeue,
2603 	.endpoint_disable	= musb_h_disable,
2604 
2605 #ifndef CONFIG_MUSB_PIO_ONLY
2606 	.map_urb_for_dma	= musb_map_urb_for_dma,
2607 	.unmap_urb_for_dma	= musb_unmap_urb_for_dma,
2608 #endif
2609 
2610 	.hub_status_data	= musb_hub_status_data,
2611 	.hub_control		= musb_hub_control,
2612 	.bus_suspend		= musb_bus_suspend,
2613 	.bus_resume		= musb_bus_resume,
2614 	/* .start_port_reset	= NULL, */
2615 	/* .hub_irq_enable	= NULL, */
2616 };
2617 
2618 int musb_host_alloc(struct musb *musb)
2619 {
2620 	struct device	*dev = musb->controller;
2621 
2622 	/* usbcore sets dev->driver_data to hcd, and sometimes uses that... */
2623 	musb->hcd = usb_create_hcd(&musb_hc_driver, dev, dev_name(dev));
2624 	if (!musb->hcd)
2625 		return -EINVAL;
2626 
2627 	*musb->hcd->hcd_priv = (unsigned long) musb;
2628 	musb->hcd->self.uses_pio_for_control = 1;
2629 	musb->hcd->uses_new_polling = 1;
2630 	musb->hcd->has_tt = 1;
2631 
2632 	return 0;
2633 }
2634 
2635 void musb_host_cleanup(struct musb *musb)
2636 {
2637 	if (musb->port_mode == MUSB_PORT_MODE_GADGET)
2638 		return;
2639 	usb_remove_hcd(musb->hcd);
2640 	musb->hcd = NULL;
2641 }
2642 
2643 void musb_host_free(struct musb *musb)
2644 {
2645 	usb_put_hcd(musb->hcd);
2646 }
2647 
2648 int musb_host_setup(struct musb *musb, int power_budget)
2649 {
2650 	int ret;
2651 	struct usb_hcd *hcd = musb->hcd;
2652 
2653 	MUSB_HST_MODE(musb);
2654 	musb->xceiv->otg->default_a = 1;
2655 	musb->xceiv->state = OTG_STATE_A_IDLE;
2656 
2657 	otg_set_host(musb->xceiv->otg, &hcd->self);
2658 	hcd->self.otg_port = 1;
2659 	musb->xceiv->otg->host = &hcd->self;
2660 	hcd->power_budget = 2 * (power_budget ? : 250);
2661 
2662 	ret = usb_add_hcd(hcd, 0, 0);
2663 	if (ret < 0)
2664 		return ret;
2665 
2666 	device_wakeup_enable(hcd->self.controller);
2667 	return 0;
2668 }
2669 
2670 void musb_host_resume_root_hub(struct musb *musb)
2671 {
2672 	usb_hcd_resume_root_hub(musb->hcd);
2673 }
2674 
2675 void musb_host_poke_root_hub(struct musb *musb)
2676 {
2677 	MUSB_HST_MODE(musb);
2678 	if (musb->hcd->status_urb)
2679 		usb_hcd_poll_rh_status(musb->hcd);
2680 	else
2681 		usb_hcd_resume_root_hub(musb->hcd);
2682 }
2683