xref: /openbmc/linux/drivers/usb/musb/musb_host.c (revision 79f08d9e)
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 /* MUSB HOST status 22-mar-2006
50  *
51  * - There's still lots of partial code duplication for fault paths, so
52  *   they aren't handled as consistently as they need to be.
53  *
54  * - PIO mostly behaved when last tested.
55  *     + including ep0, with all usbtest cases 9, 10
56  *     + usbtest 14 (ep0out) doesn't seem to run at all
57  *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
58  *       configurations, but otherwise double buffering passes basic tests.
59  *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
60  *
61  * - DMA (CPPI) ... partially behaves, not currently recommended
62  *     + about 1/15 the speed of typical EHCI implementations (PCI)
63  *     + RX, all too often reqpkt seems to misbehave after tx
64  *     + TX, no known issues (other than evident silicon issue)
65  *
66  * - DMA (Mentor/OMAP) ...has at least toggle update problems
67  *
68  * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
69  *   starvation ... nothing yet for TX, interrupt, or bulk.
70  *
71  * - Not tested with HNP, but some SRP paths seem to behave.
72  *
73  * NOTE 24-August-2006:
74  *
75  * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
76  *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
77  *   mostly works, except that with "usbnet" it's easy to trigger cases
78  *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
79  *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
80  *   although ARP RX wins.  (That test was done with a full speed link.)
81  */
82 
83 
84 /*
85  * NOTE on endpoint usage:
86  *
87  * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
88  * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
89  * (Yes, bulk _could_ use more of the endpoints than that, and would even
90  * benefit from it.)
91  *
92  * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
93  * So far that scheduling is both dumb and optimistic:  the endpoint will be
94  * "claimed" until its software queue is no longer refilled.  No multiplexing
95  * of transfers between endpoints, or anything clever.
96  */
97 
98 struct musb *hcd_to_musb(struct usb_hcd *hcd)
99 {
100 	return *(struct musb **) hcd->hcd_priv;
101 }
102 
103 
104 static void musb_ep_program(struct musb *musb, u8 epnum,
105 			struct urb *urb, int is_out,
106 			u8 *buf, u32 offset, u32 len);
107 
108 /*
109  * Clear TX fifo. Needed to avoid BABBLE errors.
110  */
111 static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
112 {
113 	struct musb	*musb = ep->musb;
114 	void __iomem	*epio = ep->regs;
115 	u16		csr;
116 	u16		lastcsr = 0;
117 	int		retries = 1000;
118 
119 	csr = musb_readw(epio, MUSB_TXCSR);
120 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
121 		if (csr != lastcsr)
122 			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
123 		lastcsr = csr;
124 		csr |= MUSB_TXCSR_FLUSHFIFO;
125 		musb_writew(epio, MUSB_TXCSR, csr);
126 		csr = musb_readw(epio, MUSB_TXCSR);
127 		if (WARN(retries-- < 1,
128 				"Could not flush host TX%d fifo: csr: %04x\n",
129 				ep->epnum, csr))
130 			return;
131 		mdelay(1);
132 	}
133 }
134 
135 static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
136 {
137 	void __iomem	*epio = ep->regs;
138 	u16		csr;
139 	int		retries = 5;
140 
141 	/* scrub any data left in the fifo */
142 	do {
143 		csr = musb_readw(epio, MUSB_TXCSR);
144 		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
145 			break;
146 		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
147 		csr = musb_readw(epio, MUSB_TXCSR);
148 		udelay(10);
149 	} while (--retries);
150 
151 	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
152 			ep->epnum, csr);
153 
154 	/* and reset for the next transfer */
155 	musb_writew(epio, MUSB_TXCSR, 0);
156 }
157 
158 /*
159  * Start transmit. Caller is responsible for locking shared resources.
160  * musb must be locked.
161  */
162 static inline void musb_h_tx_start(struct musb_hw_ep *ep)
163 {
164 	u16	txcsr;
165 
166 	/* NOTE: no locks here; caller should lock and select EP */
167 	if (ep->epnum) {
168 		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
169 		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
170 		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
171 	} else {
172 		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
173 		musb_writew(ep->regs, MUSB_CSR0, txcsr);
174 	}
175 
176 }
177 
178 static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
179 {
180 	u16	txcsr;
181 
182 	/* NOTE: no locks here; caller should lock and select EP */
183 	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
184 	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
185 	if (is_cppi_enabled())
186 		txcsr |= MUSB_TXCSR_DMAMODE;
187 	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
188 }
189 
190 static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
191 {
192 	if (is_in != 0 || ep->is_shared_fifo)
193 		ep->in_qh  = qh;
194 	if (is_in == 0 || ep->is_shared_fifo)
195 		ep->out_qh = qh;
196 }
197 
198 static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
199 {
200 	return is_in ? ep->in_qh : ep->out_qh;
201 }
202 
203 /*
204  * Start the URB at the front of an endpoint's queue
205  * end must be claimed from the caller.
206  *
207  * Context: controller locked, irqs blocked
208  */
209 static void
210 musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
211 {
212 	u16			frame;
213 	u32			len;
214 	void __iomem		*mbase =  musb->mregs;
215 	struct urb		*urb = next_urb(qh);
216 	void			*buf = urb->transfer_buffer;
217 	u32			offset = 0;
218 	struct musb_hw_ep	*hw_ep = qh->hw_ep;
219 	unsigned		pipe = urb->pipe;
220 	u8			address = usb_pipedevice(pipe);
221 	int			epnum = hw_ep->epnum;
222 
223 	/* initialize software qh state */
224 	qh->offset = 0;
225 	qh->segsize = 0;
226 
227 	/* gather right source of data */
228 	switch (qh->type) {
229 	case USB_ENDPOINT_XFER_CONTROL:
230 		/* control transfers always start with SETUP */
231 		is_in = 0;
232 		musb->ep0_stage = MUSB_EP0_START;
233 		buf = urb->setup_packet;
234 		len = 8;
235 		break;
236 	case USB_ENDPOINT_XFER_ISOC:
237 		qh->iso_idx = 0;
238 		qh->frame = 0;
239 		offset = urb->iso_frame_desc[0].offset;
240 		len = urb->iso_frame_desc[0].length;
241 		break;
242 	default:		/* bulk, interrupt */
243 		/* actual_length may be nonzero on retry paths */
244 		buf = urb->transfer_buffer + urb->actual_length;
245 		len = urb->transfer_buffer_length - urb->actual_length;
246 	}
247 
248 	dev_dbg(musb->controller, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
249 			qh, urb, address, qh->epnum,
250 			is_in ? "in" : "out",
251 			({char *s; switch (qh->type) {
252 			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
253 			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
254 			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
255 			default:			s = "-intr"; break;
256 			} s; }),
257 			epnum, buf + offset, len);
258 
259 	/* Configure endpoint */
260 	musb_ep_set_qh(hw_ep, is_in, qh);
261 	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
262 
263 	/* transmit may have more work: start it when it is time */
264 	if (is_in)
265 		return;
266 
267 	/* determine if the time is right for a periodic transfer */
268 	switch (qh->type) {
269 	case USB_ENDPOINT_XFER_ISOC:
270 	case USB_ENDPOINT_XFER_INT:
271 		dev_dbg(musb->controller, "check whether there's still time for periodic Tx\n");
272 		frame = musb_readw(mbase, MUSB_FRAME);
273 		/* FIXME this doesn't implement that scheduling policy ...
274 		 * or handle framecounter wrapping
275 		 */
276 		if (1) {	/* Always assume URB_ISO_ASAP */
277 			/* REVISIT the SOF irq handler shouldn't duplicate
278 			 * this code; and we don't init urb->start_frame...
279 			 */
280 			qh->frame = 0;
281 			goto start;
282 		} else {
283 			qh->frame = urb->start_frame;
284 			/* enable SOF interrupt so we can count down */
285 			dev_dbg(musb->controller, "SOF for %d\n", epnum);
286 #if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
287 			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
288 #endif
289 		}
290 		break;
291 	default:
292 start:
293 		dev_dbg(musb->controller, "Start TX%d %s\n", epnum,
294 			hw_ep->tx_channel ? "dma" : "pio");
295 
296 		if (!hw_ep->tx_channel)
297 			musb_h_tx_start(hw_ep);
298 		else if (is_cppi_enabled() || tusb_dma_omap())
299 			musb_h_tx_dma_start(hw_ep);
300 	}
301 }
302 
303 /* Context: caller owns controller lock, IRQs are blocked */
304 static void musb_giveback(struct musb *musb, struct urb *urb, int status)
305 __releases(musb->lock)
306 __acquires(musb->lock)
307 {
308 	dev_dbg(musb->controller,
309 			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
310 			urb, urb->complete, status,
311 			usb_pipedevice(urb->pipe),
312 			usb_pipeendpoint(urb->pipe),
313 			usb_pipein(urb->pipe) ? "in" : "out",
314 			urb->actual_length, urb->transfer_buffer_length
315 			);
316 
317 	usb_hcd_unlink_urb_from_ep(musb->hcd, urb);
318 	spin_unlock(&musb->lock);
319 	usb_hcd_giveback_urb(musb->hcd, urb, status);
320 	spin_lock(&musb->lock);
321 }
322 
323 /* For bulk/interrupt endpoints only */
324 static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
325 				    struct urb *urb)
326 {
327 	void __iomem		*epio = qh->hw_ep->regs;
328 	u16			csr;
329 
330 	/*
331 	 * FIXME: the current Mentor DMA code seems to have
332 	 * problems getting toggle correct.
333 	 */
334 
335 	if (is_in)
336 		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
337 	else
338 		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
339 
340 	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
341 }
342 
343 /*
344  * Advance this hardware endpoint's queue, completing the specified URB and
345  * advancing to either the next URB queued to that qh, or else invalidating
346  * that qh and advancing to the next qh scheduled after the current one.
347  *
348  * Context: caller owns controller lock, IRQs are blocked
349  */
350 static void musb_advance_schedule(struct musb *musb, struct urb *urb,
351 				  struct musb_hw_ep *hw_ep, int is_in)
352 {
353 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
354 	struct musb_hw_ep	*ep = qh->hw_ep;
355 	int			ready = qh->is_ready;
356 	int			status;
357 
358 	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
359 
360 	/* save toggle eagerly, for paranoia */
361 	switch (qh->type) {
362 	case USB_ENDPOINT_XFER_BULK:
363 	case USB_ENDPOINT_XFER_INT:
364 		musb_save_toggle(qh, is_in, urb);
365 		break;
366 	case USB_ENDPOINT_XFER_ISOC:
367 		if (status == 0 && urb->error_count)
368 			status = -EXDEV;
369 		break;
370 	}
371 
372 	qh->is_ready = 0;
373 	musb_giveback(musb, urb, status);
374 	qh->is_ready = ready;
375 
376 	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
377 	 * invalidate qh as soon as list_empty(&hep->urb_list)
378 	 */
379 	if (list_empty(&qh->hep->urb_list)) {
380 		struct list_head	*head;
381 		struct dma_controller	*dma = musb->dma_controller;
382 
383 		if (is_in) {
384 			ep->rx_reinit = 1;
385 			if (ep->rx_channel) {
386 				dma->channel_release(ep->rx_channel);
387 				ep->rx_channel = NULL;
388 			}
389 		} else {
390 			ep->tx_reinit = 1;
391 			if (ep->tx_channel) {
392 				dma->channel_release(ep->tx_channel);
393 				ep->tx_channel = NULL;
394 			}
395 		}
396 
397 		/* Clobber old pointers to this qh */
398 		musb_ep_set_qh(ep, is_in, NULL);
399 		qh->hep->hcpriv = NULL;
400 
401 		switch (qh->type) {
402 
403 		case USB_ENDPOINT_XFER_CONTROL:
404 		case USB_ENDPOINT_XFER_BULK:
405 			/* fifo policy for these lists, except that NAKing
406 			 * should rotate a qh to the end (for fairness).
407 			 */
408 			if (qh->mux == 1) {
409 				head = qh->ring.prev;
410 				list_del(&qh->ring);
411 				kfree(qh);
412 				qh = first_qh(head);
413 				break;
414 			}
415 
416 		case USB_ENDPOINT_XFER_ISOC:
417 		case USB_ENDPOINT_XFER_INT:
418 			/* this is where periodic bandwidth should be
419 			 * de-allocated if it's tracked and allocated;
420 			 * and where we'd update the schedule tree...
421 			 */
422 			kfree(qh);
423 			qh = NULL;
424 			break;
425 		}
426 	}
427 
428 	if (qh != NULL && qh->is_ready) {
429 		dev_dbg(musb->controller, "... next ep%d %cX urb %p\n",
430 		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
431 		musb_start_urb(musb, is_in, qh);
432 	}
433 }
434 
435 static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
436 {
437 	/* we don't want fifo to fill itself again;
438 	 * ignore dma (various models),
439 	 * leave toggle alone (may not have been saved yet)
440 	 */
441 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
442 	csr &= ~(MUSB_RXCSR_H_REQPKT
443 		| MUSB_RXCSR_H_AUTOREQ
444 		| MUSB_RXCSR_AUTOCLEAR);
445 
446 	/* write 2x to allow double buffering */
447 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
448 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
449 
450 	/* flush writebuffer */
451 	return musb_readw(hw_ep->regs, MUSB_RXCSR);
452 }
453 
454 /*
455  * PIO RX for a packet (or part of it).
456  */
457 static bool
458 musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
459 {
460 	u16			rx_count;
461 	u8			*buf;
462 	u16			csr;
463 	bool			done = false;
464 	u32			length;
465 	int			do_flush = 0;
466 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
467 	void __iomem		*epio = hw_ep->regs;
468 	struct musb_qh		*qh = hw_ep->in_qh;
469 	int			pipe = urb->pipe;
470 	void			*buffer = urb->transfer_buffer;
471 
472 	/* musb_ep_select(mbase, epnum); */
473 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
474 	dev_dbg(musb->controller, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
475 			urb->transfer_buffer, qh->offset,
476 			urb->transfer_buffer_length);
477 
478 	/* unload FIFO */
479 	if (usb_pipeisoc(pipe)) {
480 		int					status = 0;
481 		struct usb_iso_packet_descriptor	*d;
482 
483 		if (iso_err) {
484 			status = -EILSEQ;
485 			urb->error_count++;
486 		}
487 
488 		d = urb->iso_frame_desc + qh->iso_idx;
489 		buf = buffer + d->offset;
490 		length = d->length;
491 		if (rx_count > length) {
492 			if (status == 0) {
493 				status = -EOVERFLOW;
494 				urb->error_count++;
495 			}
496 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
497 			do_flush = 1;
498 		} else
499 			length = rx_count;
500 		urb->actual_length += length;
501 		d->actual_length = length;
502 
503 		d->status = status;
504 
505 		/* see if we are done */
506 		done = (++qh->iso_idx >= urb->number_of_packets);
507 	} else {
508 		/* non-isoch */
509 		buf = buffer + qh->offset;
510 		length = urb->transfer_buffer_length - qh->offset;
511 		if (rx_count > length) {
512 			if (urb->status == -EINPROGRESS)
513 				urb->status = -EOVERFLOW;
514 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
515 			do_flush = 1;
516 		} else
517 			length = rx_count;
518 		urb->actual_length += length;
519 		qh->offset += length;
520 
521 		/* see if we are done */
522 		done = (urb->actual_length == urb->transfer_buffer_length)
523 			|| (rx_count < qh->maxpacket)
524 			|| (urb->status != -EINPROGRESS);
525 		if (done
526 				&& (urb->status == -EINPROGRESS)
527 				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
528 				&& (urb->actual_length
529 					< urb->transfer_buffer_length))
530 			urb->status = -EREMOTEIO;
531 	}
532 
533 	musb_read_fifo(hw_ep, length, buf);
534 
535 	csr = musb_readw(epio, MUSB_RXCSR);
536 	csr |= MUSB_RXCSR_H_WZC_BITS;
537 	if (unlikely(do_flush))
538 		musb_h_flush_rxfifo(hw_ep, csr);
539 	else {
540 		/* REVISIT this assumes AUTOCLEAR is never set */
541 		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
542 		if (!done)
543 			csr |= MUSB_RXCSR_H_REQPKT;
544 		musb_writew(epio, MUSB_RXCSR, csr);
545 	}
546 
547 	return done;
548 }
549 
550 /* we don't always need to reinit a given side of an endpoint...
551  * when we do, use tx/rx reinit routine and then construct a new CSR
552  * to address data toggle, NYET, and DMA or PIO.
553  *
554  * it's possible that driver bugs (especially for DMA) or aborting a
555  * transfer might have left the endpoint busier than it should be.
556  * the busy/not-empty tests are basically paranoia.
557  */
558 static void
559 musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
560 {
561 	u16	csr;
562 
563 	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
564 	 * That always uses tx_reinit since ep0 repurposes TX register
565 	 * offsets; the initial SETUP packet is also a kind of OUT.
566 	 */
567 
568 	/* if programmed for Tx, put it in RX mode */
569 	if (ep->is_shared_fifo) {
570 		csr = musb_readw(ep->regs, MUSB_TXCSR);
571 		if (csr & MUSB_TXCSR_MODE) {
572 			musb_h_tx_flush_fifo(ep);
573 			csr = musb_readw(ep->regs, MUSB_TXCSR);
574 			musb_writew(ep->regs, MUSB_TXCSR,
575 				    csr | MUSB_TXCSR_FRCDATATOG);
576 		}
577 
578 		/*
579 		 * Clear the MODE bit (and everything else) to enable Rx.
580 		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
581 		 */
582 		if (csr & MUSB_TXCSR_DMAMODE)
583 			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
584 		musb_writew(ep->regs, MUSB_TXCSR, 0);
585 
586 	/* scrub all previous state, clearing toggle */
587 	} else {
588 		csr = musb_readw(ep->regs, MUSB_RXCSR);
589 		if (csr & MUSB_RXCSR_RXPKTRDY)
590 			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
591 				musb_readw(ep->regs, MUSB_RXCOUNT));
592 
593 		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
594 	}
595 
596 	/* target addr and (for multipoint) hub addr/port */
597 	if (musb->is_multipoint) {
598 		musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
599 		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
600 		musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
601 
602 	} else
603 		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
604 
605 	/* protocol/endpoint, interval/NAKlimit, i/o size */
606 	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
607 	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
608 	/* NOTE: bulk combining rewrites high bits of maxpacket */
609 	/* Set RXMAXP with the FIFO size of the endpoint
610 	 * to disable double buffer mode.
611 	 */
612 	if (musb->double_buffer_not_ok)
613 		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
614 	else
615 		musb_writew(ep->regs, MUSB_RXMAXP,
616 				qh->maxpacket | ((qh->hb_mult - 1) << 11));
617 
618 	ep->rx_reinit = 0;
619 }
620 
621 static bool musb_tx_dma_program(struct dma_controller *dma,
622 		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
623 		struct urb *urb, u32 offset, u32 length)
624 {
625 	struct dma_channel	*channel = hw_ep->tx_channel;
626 	void __iomem		*epio = hw_ep->regs;
627 	u16			pkt_size = qh->maxpacket;
628 	u16			csr;
629 	u8			mode;
630 
631 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
632 	if (length > channel->max_len)
633 		length = channel->max_len;
634 
635 	csr = musb_readw(epio, MUSB_TXCSR);
636 	if (length > pkt_size) {
637 		mode = 1;
638 		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
639 		/* autoset shouldn't be set in high bandwidth */
640 		/*
641 		 * Enable Autoset according to table
642 		 * below
643 		 * bulk_split hb_mult	Autoset_Enable
644 		 *	0	1	Yes(Normal)
645 		 *	0	>1	No(High BW ISO)
646 		 *	1	1	Yes(HS bulk)
647 		 *	1	>1	Yes(FS bulk)
648 		 */
649 		if (qh->hb_mult == 1 || (qh->hb_mult > 1 &&
650 					can_bulk_split(hw_ep->musb, qh->type)))
651 			csr |= MUSB_TXCSR_AUTOSET;
652 	} else {
653 		mode = 0;
654 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
655 		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
656 	}
657 	channel->desired_mode = mode;
658 	musb_writew(epio, MUSB_TXCSR, csr);
659 #else
660 	if (!is_cppi_enabled() && !tusb_dma_omap())
661 		return false;
662 
663 	channel->actual_len = 0;
664 
665 	/*
666 	 * TX uses "RNDIS" mode automatically but needs help
667 	 * to identify the zero-length-final-packet case.
668 	 */
669 	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
670 #endif
671 
672 	qh->segsize = length;
673 
674 	/*
675 	 * Ensure the data reaches to main memory before starting
676 	 * DMA transfer
677 	 */
678 	wmb();
679 
680 	if (!dma->channel_program(channel, pkt_size, mode,
681 			urb->transfer_dma + offset, length)) {
682 		dma->channel_release(channel);
683 		hw_ep->tx_channel = NULL;
684 
685 		csr = musb_readw(epio, MUSB_TXCSR);
686 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
687 		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
688 		return false;
689 	}
690 	return true;
691 }
692 
693 /*
694  * Program an HDRC endpoint as per the given URB
695  * Context: irqs blocked, controller lock held
696  */
697 static void musb_ep_program(struct musb *musb, u8 epnum,
698 			struct urb *urb, int is_out,
699 			u8 *buf, u32 offset, u32 len)
700 {
701 	struct dma_controller	*dma_controller;
702 	struct dma_channel	*dma_channel;
703 	u8			dma_ok;
704 	void __iomem		*mbase = musb->mregs;
705 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
706 	void __iomem		*epio = hw_ep->regs;
707 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
708 	u16			packet_sz = qh->maxpacket;
709 	u8			use_dma = 1;
710 	u16			csr;
711 
712 	dev_dbg(musb->controller, "%s hw%d urb %p spd%d dev%d ep%d%s "
713 				"h_addr%02x h_port%02x bytes %d\n",
714 			is_out ? "-->" : "<--",
715 			epnum, urb, urb->dev->speed,
716 			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
717 			qh->h_addr_reg, qh->h_port_reg,
718 			len);
719 
720 	musb_ep_select(mbase, epnum);
721 
722 	if (is_out && !len) {
723 		use_dma = 0;
724 		csr = musb_readw(epio, MUSB_TXCSR);
725 		csr &= ~MUSB_TXCSR_DMAENAB;
726 		musb_writew(epio, MUSB_TXCSR, csr);
727 		hw_ep->tx_channel = NULL;
728 	}
729 
730 	/* candidate for DMA? */
731 	dma_controller = musb->dma_controller;
732 	if (use_dma && is_dma_capable() && epnum && dma_controller) {
733 		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
734 		if (!dma_channel) {
735 			dma_channel = dma_controller->channel_alloc(
736 					dma_controller, hw_ep, is_out);
737 			if (is_out)
738 				hw_ep->tx_channel = dma_channel;
739 			else
740 				hw_ep->rx_channel = dma_channel;
741 		}
742 	} else
743 		dma_channel = NULL;
744 
745 	/* make sure we clear DMAEnab, autoSet bits from previous run */
746 
747 	/* OUT/transmit/EP0 or IN/receive? */
748 	if (is_out) {
749 		u16	csr;
750 		u16	int_txe;
751 		u16	load_count;
752 
753 		csr = musb_readw(epio, MUSB_TXCSR);
754 
755 		/* disable interrupt in case we flush */
756 		int_txe = musb->intrtxe;
757 		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
758 
759 		/* general endpoint setup */
760 		if (epnum) {
761 			/* flush all old state, set default */
762 			/*
763 			 * We could be flushing valid
764 			 * packets in double buffering
765 			 * case
766 			 */
767 			if (!hw_ep->tx_double_buffered)
768 				musb_h_tx_flush_fifo(hw_ep);
769 
770 			/*
771 			 * We must not clear the DMAMODE bit before or in
772 			 * the same cycle with the DMAENAB bit, so we clear
773 			 * the latter first...
774 			 */
775 			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
776 					| MUSB_TXCSR_AUTOSET
777 					| MUSB_TXCSR_DMAENAB
778 					| MUSB_TXCSR_FRCDATATOG
779 					| MUSB_TXCSR_H_RXSTALL
780 					| MUSB_TXCSR_H_ERROR
781 					| MUSB_TXCSR_TXPKTRDY
782 					);
783 			csr |= MUSB_TXCSR_MODE;
784 
785 			if (!hw_ep->tx_double_buffered) {
786 				if (usb_gettoggle(urb->dev, qh->epnum, 1))
787 					csr |= MUSB_TXCSR_H_WR_DATATOGGLE
788 						| MUSB_TXCSR_H_DATATOGGLE;
789 				else
790 					csr |= MUSB_TXCSR_CLRDATATOG;
791 			}
792 
793 			musb_writew(epio, MUSB_TXCSR, csr);
794 			/* REVISIT may need to clear FLUSHFIFO ... */
795 			csr &= ~MUSB_TXCSR_DMAMODE;
796 			musb_writew(epio, MUSB_TXCSR, csr);
797 			csr = musb_readw(epio, MUSB_TXCSR);
798 		} else {
799 			/* endpoint 0: just flush */
800 			musb_h_ep0_flush_fifo(hw_ep);
801 		}
802 
803 		/* target addr and (for multipoint) hub addr/port */
804 		if (musb->is_multipoint) {
805 			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
806 			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
807 			musb_write_txhubport(mbase, epnum, qh->h_port_reg);
808 /* FIXME if !epnum, do the same for RX ... */
809 		} else
810 			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
811 
812 		/* protocol/endpoint/interval/NAKlimit */
813 		if (epnum) {
814 			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
815 			if (musb->double_buffer_not_ok) {
816 				musb_writew(epio, MUSB_TXMAXP,
817 						hw_ep->max_packet_sz_tx);
818 			} else if (can_bulk_split(musb, qh->type)) {
819 				qh->hb_mult = hw_ep->max_packet_sz_tx
820 						/ packet_sz;
821 				musb_writew(epio, MUSB_TXMAXP, packet_sz
822 					| ((qh->hb_mult) - 1) << 11);
823 			} else {
824 				musb_writew(epio, MUSB_TXMAXP,
825 						qh->maxpacket |
826 						((qh->hb_mult - 1) << 11));
827 			}
828 			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
829 		} else {
830 			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
831 			if (musb->is_multipoint)
832 				musb_writeb(epio, MUSB_TYPE0,
833 						qh->type_reg);
834 		}
835 
836 		if (can_bulk_split(musb, qh->type))
837 			load_count = min((u32) hw_ep->max_packet_sz_tx,
838 						len);
839 		else
840 			load_count = min((u32) packet_sz, len);
841 
842 		if (dma_channel && musb_tx_dma_program(dma_controller,
843 					hw_ep, qh, urb, offset, len))
844 			load_count = 0;
845 
846 		if (load_count) {
847 			/* PIO to load FIFO */
848 			qh->segsize = load_count;
849 			if (!buf) {
850 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
851 						SG_MITER_ATOMIC
852 						| SG_MITER_FROM_SG);
853 				if (!sg_miter_next(&qh->sg_miter)) {
854 					dev_err(musb->controller,
855 							"error: sg"
856 							"list empty\n");
857 					sg_miter_stop(&qh->sg_miter);
858 					goto finish;
859 				}
860 				buf = qh->sg_miter.addr + urb->sg->offset +
861 					urb->actual_length;
862 				load_count = min_t(u32, load_count,
863 						qh->sg_miter.length);
864 				musb_write_fifo(hw_ep, load_count, buf);
865 				qh->sg_miter.consumed = load_count;
866 				sg_miter_stop(&qh->sg_miter);
867 			} else
868 				musb_write_fifo(hw_ep, load_count, buf);
869 		}
870 finish:
871 		/* re-enable interrupt */
872 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
873 
874 	/* IN/receive */
875 	} else {
876 		u16	csr;
877 
878 		if (hw_ep->rx_reinit) {
879 			musb_rx_reinit(musb, qh, hw_ep);
880 
881 			/* init new state: toggle and NYET, maybe DMA later */
882 			if (usb_gettoggle(urb->dev, qh->epnum, 0))
883 				csr = MUSB_RXCSR_H_WR_DATATOGGLE
884 					| MUSB_RXCSR_H_DATATOGGLE;
885 			else
886 				csr = 0;
887 			if (qh->type == USB_ENDPOINT_XFER_INT)
888 				csr |= MUSB_RXCSR_DISNYET;
889 
890 		} else {
891 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
892 
893 			if (csr & (MUSB_RXCSR_RXPKTRDY
894 					| MUSB_RXCSR_DMAENAB
895 					| MUSB_RXCSR_H_REQPKT))
896 				ERR("broken !rx_reinit, ep%d csr %04x\n",
897 						hw_ep->epnum, csr);
898 
899 			/* scrub any stale state, leaving toggle alone */
900 			csr &= MUSB_RXCSR_DISNYET;
901 		}
902 
903 		/* kick things off */
904 
905 		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
906 			/* Candidate for DMA */
907 			dma_channel->actual_len = 0L;
908 			qh->segsize = len;
909 
910 			/* AUTOREQ is in a DMA register */
911 			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
912 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
913 
914 			/*
915 			 * Unless caller treats short RX transfers as
916 			 * errors, we dare not queue multiple transfers.
917 			 */
918 			dma_ok = dma_controller->channel_program(dma_channel,
919 					packet_sz, !(urb->transfer_flags &
920 						     URB_SHORT_NOT_OK),
921 					urb->transfer_dma + offset,
922 					qh->segsize);
923 			if (!dma_ok) {
924 				dma_controller->channel_release(dma_channel);
925 				hw_ep->rx_channel = dma_channel = NULL;
926 			} else
927 				csr |= MUSB_RXCSR_DMAENAB;
928 		}
929 
930 		csr |= MUSB_RXCSR_H_REQPKT;
931 		dev_dbg(musb->controller, "RXCSR%d := %04x\n", epnum, csr);
932 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
933 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
934 	}
935 }
936 
937 /* Schedule next QH from musb->in_bulk/out_bulk and move the current qh to
938  * the end; avoids starvation for other endpoints.
939  */
940 static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep,
941 	int is_in)
942 {
943 	struct dma_channel	*dma;
944 	struct urb		*urb;
945 	void __iomem		*mbase = musb->mregs;
946 	void __iomem		*epio = ep->regs;
947 	struct musb_qh		*cur_qh, *next_qh;
948 	u16			rx_csr, tx_csr;
949 
950 	musb_ep_select(mbase, ep->epnum);
951 	if (is_in) {
952 		dma = is_dma_capable() ? ep->rx_channel : NULL;
953 
954 		/* clear nak timeout bit */
955 		rx_csr = musb_readw(epio, MUSB_RXCSR);
956 		rx_csr |= MUSB_RXCSR_H_WZC_BITS;
957 		rx_csr &= ~MUSB_RXCSR_DATAERROR;
958 		musb_writew(epio, MUSB_RXCSR, rx_csr);
959 
960 		cur_qh = first_qh(&musb->in_bulk);
961 	} else {
962 		dma = is_dma_capable() ? ep->tx_channel : NULL;
963 
964 		/* clear nak timeout bit */
965 		tx_csr = musb_readw(epio, MUSB_TXCSR);
966 		tx_csr |= MUSB_TXCSR_H_WZC_BITS;
967 		tx_csr &= ~MUSB_TXCSR_H_NAKTIMEOUT;
968 		musb_writew(epio, MUSB_TXCSR, tx_csr);
969 
970 		cur_qh = first_qh(&musb->out_bulk);
971 	}
972 	if (cur_qh) {
973 		urb = next_urb(cur_qh);
974 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
975 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
976 			musb->dma_controller->channel_abort(dma);
977 			urb->actual_length += dma->actual_len;
978 			dma->actual_len = 0L;
979 		}
980 		musb_save_toggle(cur_qh, is_in, urb);
981 
982 		if (is_in) {
983 			/* move cur_qh to end of queue */
984 			list_move_tail(&cur_qh->ring, &musb->in_bulk);
985 
986 			/* get the next qh from musb->in_bulk */
987 			next_qh = first_qh(&musb->in_bulk);
988 
989 			/* set rx_reinit and schedule the next qh */
990 			ep->rx_reinit = 1;
991 		} else {
992 			/* move cur_qh to end of queue */
993 			list_move_tail(&cur_qh->ring, &musb->out_bulk);
994 
995 			/* get the next qh from musb->out_bulk */
996 			next_qh = first_qh(&musb->out_bulk);
997 
998 			/* set tx_reinit and schedule the next qh */
999 			ep->tx_reinit = 1;
1000 		}
1001 		musb_start_urb(musb, is_in, next_qh);
1002 	}
1003 }
1004 
1005 /*
1006  * Service the default endpoint (ep0) as host.
1007  * Return true until it's time to start the status stage.
1008  */
1009 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
1010 {
1011 	bool			 more = false;
1012 	u8			*fifo_dest = NULL;
1013 	u16			fifo_count = 0;
1014 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1015 	struct musb_qh		*qh = hw_ep->in_qh;
1016 	struct usb_ctrlrequest	*request;
1017 
1018 	switch (musb->ep0_stage) {
1019 	case MUSB_EP0_IN:
1020 		fifo_dest = urb->transfer_buffer + urb->actual_length;
1021 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
1022 				   urb->actual_length);
1023 		if (fifo_count < len)
1024 			urb->status = -EOVERFLOW;
1025 
1026 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
1027 
1028 		urb->actual_length += fifo_count;
1029 		if (len < qh->maxpacket) {
1030 			/* always terminate on short read; it's
1031 			 * rarely reported as an error.
1032 			 */
1033 		} else if (urb->actual_length <
1034 				urb->transfer_buffer_length)
1035 			more = true;
1036 		break;
1037 	case MUSB_EP0_START:
1038 		request = (struct usb_ctrlrequest *) urb->setup_packet;
1039 
1040 		if (!request->wLength) {
1041 			dev_dbg(musb->controller, "start no-DATA\n");
1042 			break;
1043 		} else if (request->bRequestType & USB_DIR_IN) {
1044 			dev_dbg(musb->controller, "start IN-DATA\n");
1045 			musb->ep0_stage = MUSB_EP0_IN;
1046 			more = true;
1047 			break;
1048 		} else {
1049 			dev_dbg(musb->controller, "start OUT-DATA\n");
1050 			musb->ep0_stage = MUSB_EP0_OUT;
1051 			more = true;
1052 		}
1053 		/* FALLTHROUGH */
1054 	case MUSB_EP0_OUT:
1055 		fifo_count = min_t(size_t, qh->maxpacket,
1056 				   urb->transfer_buffer_length -
1057 				   urb->actual_length);
1058 		if (fifo_count) {
1059 			fifo_dest = (u8 *) (urb->transfer_buffer
1060 					+ urb->actual_length);
1061 			dev_dbg(musb->controller, "Sending %d byte%s to ep0 fifo %p\n",
1062 					fifo_count,
1063 					(fifo_count == 1) ? "" : "s",
1064 					fifo_dest);
1065 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
1066 
1067 			urb->actual_length += fifo_count;
1068 			more = true;
1069 		}
1070 		break;
1071 	default:
1072 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
1073 		break;
1074 	}
1075 
1076 	return more;
1077 }
1078 
1079 /*
1080  * Handle default endpoint interrupt as host. Only called in IRQ time
1081  * from musb_interrupt().
1082  *
1083  * called with controller irqlocked
1084  */
1085 irqreturn_t musb_h_ep0_irq(struct musb *musb)
1086 {
1087 	struct urb		*urb;
1088 	u16			csr, len;
1089 	int			status = 0;
1090 	void __iomem		*mbase = musb->mregs;
1091 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1092 	void __iomem		*epio = hw_ep->regs;
1093 	struct musb_qh		*qh = hw_ep->in_qh;
1094 	bool			complete = false;
1095 	irqreturn_t		retval = IRQ_NONE;
1096 
1097 	/* ep0 only has one queue, "in" */
1098 	urb = next_urb(qh);
1099 
1100 	musb_ep_select(mbase, 0);
1101 	csr = musb_readw(epio, MUSB_CSR0);
1102 	len = (csr & MUSB_CSR0_RXPKTRDY)
1103 			? musb_readb(epio, MUSB_COUNT0)
1104 			: 0;
1105 
1106 	dev_dbg(musb->controller, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
1107 		csr, qh, len, urb, musb->ep0_stage);
1108 
1109 	/* if we just did status stage, we are done */
1110 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
1111 		retval = IRQ_HANDLED;
1112 		complete = true;
1113 	}
1114 
1115 	/* prepare status */
1116 	if (csr & MUSB_CSR0_H_RXSTALL) {
1117 		dev_dbg(musb->controller, "STALLING ENDPOINT\n");
1118 		status = -EPIPE;
1119 
1120 	} else if (csr & MUSB_CSR0_H_ERROR) {
1121 		dev_dbg(musb->controller, "no response, csr0 %04x\n", csr);
1122 		status = -EPROTO;
1123 
1124 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1125 		dev_dbg(musb->controller, "control NAK timeout\n");
1126 
1127 		/* NOTE:  this code path would be a good place to PAUSE a
1128 		 * control transfer, if another one is queued, so that
1129 		 * ep0 is more likely to stay busy.  That's already done
1130 		 * for bulk RX transfers.
1131 		 *
1132 		 * if (qh->ring.next != &musb->control), then
1133 		 * we have a candidate... NAKing is *NOT* an error
1134 		 */
1135 		musb_writew(epio, MUSB_CSR0, 0);
1136 		retval = IRQ_HANDLED;
1137 	}
1138 
1139 	if (status) {
1140 		dev_dbg(musb->controller, "aborting\n");
1141 		retval = IRQ_HANDLED;
1142 		if (urb)
1143 			urb->status = status;
1144 		complete = true;
1145 
1146 		/* use the proper sequence to abort the transfer */
1147 		if (csr & MUSB_CSR0_H_REQPKT) {
1148 			csr &= ~MUSB_CSR0_H_REQPKT;
1149 			musb_writew(epio, MUSB_CSR0, csr);
1150 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1151 			musb_writew(epio, MUSB_CSR0, csr);
1152 		} else {
1153 			musb_h_ep0_flush_fifo(hw_ep);
1154 		}
1155 
1156 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1157 
1158 		/* clear it */
1159 		musb_writew(epio, MUSB_CSR0, 0);
1160 	}
1161 
1162 	if (unlikely(!urb)) {
1163 		/* stop endpoint since we have no place for its data, this
1164 		 * SHOULD NEVER HAPPEN! */
1165 		ERR("no URB for end 0\n");
1166 
1167 		musb_h_ep0_flush_fifo(hw_ep);
1168 		goto done;
1169 	}
1170 
1171 	if (!complete) {
1172 		/* call common logic and prepare response */
1173 		if (musb_h_ep0_continue(musb, len, urb)) {
1174 			/* more packets required */
1175 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1176 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1177 		} else {
1178 			/* data transfer complete; perform status phase */
1179 			if (usb_pipeout(urb->pipe)
1180 					|| !urb->transfer_buffer_length)
1181 				csr = MUSB_CSR0_H_STATUSPKT
1182 					| MUSB_CSR0_H_REQPKT;
1183 			else
1184 				csr = MUSB_CSR0_H_STATUSPKT
1185 					| MUSB_CSR0_TXPKTRDY;
1186 
1187 			/* flag status stage */
1188 			musb->ep0_stage = MUSB_EP0_STATUS;
1189 
1190 			dev_dbg(musb->controller, "ep0 STATUS, csr %04x\n", csr);
1191 
1192 		}
1193 		musb_writew(epio, MUSB_CSR0, csr);
1194 		retval = IRQ_HANDLED;
1195 	} else
1196 		musb->ep0_stage = MUSB_EP0_IDLE;
1197 
1198 	/* call completion handler if done */
1199 	if (complete)
1200 		musb_advance_schedule(musb, urb, hw_ep, 1);
1201 done:
1202 	return retval;
1203 }
1204 
1205 
1206 #ifdef CONFIG_USB_INVENTRA_DMA
1207 
1208 /* Host side TX (OUT) using Mentor DMA works as follows:
1209 	submit_urb ->
1210 		- if queue was empty, Program Endpoint
1211 		- ... which starts DMA to fifo in mode 1 or 0
1212 
1213 	DMA Isr (transfer complete) -> TxAvail()
1214 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1215 					only in musb_cleanup_urb)
1216 		- TxPktRdy has to be set in mode 0 or for
1217 			short packets in mode 1.
1218 */
1219 
1220 #endif
1221 
1222 /* Service a Tx-Available or dma completion irq for the endpoint */
1223 void musb_host_tx(struct musb *musb, u8 epnum)
1224 {
1225 	int			pipe;
1226 	bool			done = false;
1227 	u16			tx_csr;
1228 	size_t			length = 0;
1229 	size_t			offset = 0;
1230 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1231 	void __iomem		*epio = hw_ep->regs;
1232 	struct musb_qh		*qh = hw_ep->out_qh;
1233 	struct urb		*urb = next_urb(qh);
1234 	u32			status = 0;
1235 	void __iomem		*mbase = musb->mregs;
1236 	struct dma_channel	*dma;
1237 	bool			transfer_pending = false;
1238 
1239 	musb_ep_select(mbase, epnum);
1240 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1241 
1242 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1243 	if (!urb) {
1244 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1245 		return;
1246 	}
1247 
1248 	pipe = urb->pipe;
1249 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1250 	dev_dbg(musb->controller, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
1251 			dma ? ", dma" : "");
1252 
1253 	/* check for errors */
1254 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1255 		/* dma was disabled, fifo flushed */
1256 		dev_dbg(musb->controller, "TX end %d stall\n", epnum);
1257 
1258 		/* stall; record URB status */
1259 		status = -EPIPE;
1260 
1261 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1262 		/* (NON-ISO) dma was disabled, fifo flushed */
1263 		dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum);
1264 
1265 		status = -ETIMEDOUT;
1266 
1267 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1268 		if (USB_ENDPOINT_XFER_BULK == qh->type && qh->mux == 1
1269 				&& !list_is_singular(&musb->out_bulk)) {
1270 			dev_dbg(musb->controller,
1271 				"NAK timeout on TX%d ep\n", epnum);
1272 			musb_bulk_nak_timeout(musb, hw_ep, 0);
1273 		} else {
1274 			dev_dbg(musb->controller,
1275 				"TX end=%d device not responding\n", epnum);
1276 			/* NOTE:  this code path would be a good place to PAUSE a
1277 			 * transfer, if there's some other (nonperiodic) tx urb
1278 			 * that could use this fifo.  (dma complicates it...)
1279 			 * That's already done for bulk RX transfers.
1280 			 *
1281 			 * if (bulk && qh->ring.next != &musb->out_bulk), then
1282 			 * we have a candidate... NAKing is *NOT* an error
1283 			 */
1284 			musb_ep_select(mbase, epnum);
1285 			musb_writew(epio, MUSB_TXCSR,
1286 					MUSB_TXCSR_H_WZC_BITS
1287 					| MUSB_TXCSR_TXPKTRDY);
1288 		}
1289 			return;
1290 	}
1291 
1292 done:
1293 	if (status) {
1294 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1295 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1296 			(void) musb->dma_controller->channel_abort(dma);
1297 		}
1298 
1299 		/* do the proper sequence to abort the transfer in the
1300 		 * usb core; the dma engine should already be stopped.
1301 		 */
1302 		musb_h_tx_flush_fifo(hw_ep);
1303 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1304 				| MUSB_TXCSR_DMAENAB
1305 				| MUSB_TXCSR_H_ERROR
1306 				| MUSB_TXCSR_H_RXSTALL
1307 				| MUSB_TXCSR_H_NAKTIMEOUT
1308 				);
1309 
1310 		musb_ep_select(mbase, epnum);
1311 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1312 		/* REVISIT may need to clear FLUSHFIFO ... */
1313 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1314 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1315 
1316 		done = true;
1317 	}
1318 
1319 	/* second cppi case */
1320 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1321 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1322 		return;
1323 	}
1324 
1325 	if (is_dma_capable() && dma && !status) {
1326 		/*
1327 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1328 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1329 		 * we can consider this transfer completed, lest we trash
1330 		 * its last packet when writing the next URB's data.  So we
1331 		 * switch back to mode 0 to get that interrupt; we'll come
1332 		 * back here once it happens.
1333 		 */
1334 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1335 			/*
1336 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1337 			 * clear them in a safe order.  That should be OK
1338 			 * once TXPKTRDY has been set (and I've never seen
1339 			 * it being 0 at this moment -- DMA interrupt latency
1340 			 * is significant) but if it hasn't been then we have
1341 			 * no choice but to stop being polite and ignore the
1342 			 * programmer's guide... :-)
1343 			 *
1344 			 * Note that we must write TXCSR with TXPKTRDY cleared
1345 			 * in order not to re-trigger the packet send (this bit
1346 			 * can't be cleared by CPU), and there's another caveat:
1347 			 * TXPKTRDY may be set shortly and then cleared in the
1348 			 * double-buffered FIFO mode, so we do an extra TXCSR
1349 			 * read for debouncing...
1350 			 */
1351 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1352 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1353 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1354 					    MUSB_TXCSR_TXPKTRDY);
1355 				musb_writew(epio, MUSB_TXCSR,
1356 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1357 			}
1358 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1359 				    MUSB_TXCSR_TXPKTRDY);
1360 			musb_writew(epio, MUSB_TXCSR,
1361 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1362 
1363 			/*
1364 			 * There is no guarantee that we'll get an interrupt
1365 			 * after clearing DMAMODE as we might have done this
1366 			 * too late (after TXPKTRDY was cleared by controller).
1367 			 * Re-read TXCSR as we have spoiled its previous value.
1368 			 */
1369 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1370 		}
1371 
1372 		/*
1373 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1374 		 * In any case, we must check the FIFO status here and bail out
1375 		 * only if the FIFO still has data -- that should prevent the
1376 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1377 		 * FIFO mode too...
1378 		 */
1379 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1380 			dev_dbg(musb->controller, "DMA complete but packet still in FIFO, "
1381 			    "CSR %04x\n", tx_csr);
1382 			return;
1383 		}
1384 	}
1385 
1386 	if (!status || dma || usb_pipeisoc(pipe)) {
1387 		if (dma)
1388 			length = dma->actual_len;
1389 		else
1390 			length = qh->segsize;
1391 		qh->offset += length;
1392 
1393 		if (usb_pipeisoc(pipe)) {
1394 			struct usb_iso_packet_descriptor	*d;
1395 
1396 			d = urb->iso_frame_desc + qh->iso_idx;
1397 			d->actual_length = length;
1398 			d->status = status;
1399 			if (++qh->iso_idx >= urb->number_of_packets) {
1400 				done = true;
1401 			} else {
1402 				d++;
1403 				offset = d->offset;
1404 				length = d->length;
1405 			}
1406 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1407 			done = true;
1408 		} else {
1409 			/* see if we need to send more data, or ZLP */
1410 			if (qh->segsize < qh->maxpacket)
1411 				done = true;
1412 			else if (qh->offset == urb->transfer_buffer_length
1413 					&& !(urb->transfer_flags
1414 						& URB_ZERO_PACKET))
1415 				done = true;
1416 			if (!done) {
1417 				offset = qh->offset;
1418 				length = urb->transfer_buffer_length - offset;
1419 				transfer_pending = true;
1420 			}
1421 		}
1422 	}
1423 
1424 	/* urb->status != -EINPROGRESS means request has been faulted,
1425 	 * so we must abort this transfer after cleanup
1426 	 */
1427 	if (urb->status != -EINPROGRESS) {
1428 		done = true;
1429 		if (status == 0)
1430 			status = urb->status;
1431 	}
1432 
1433 	if (done) {
1434 		/* set status */
1435 		urb->status = status;
1436 		urb->actual_length = qh->offset;
1437 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1438 		return;
1439 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1440 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1441 				offset, length)) {
1442 			if (is_cppi_enabled() || tusb_dma_omap())
1443 				musb_h_tx_dma_start(hw_ep);
1444 			return;
1445 		}
1446 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1447 		dev_dbg(musb->controller, "not complete, but DMA enabled?\n");
1448 		return;
1449 	}
1450 
1451 	/*
1452 	 * PIO: start next packet in this URB.
1453 	 *
1454 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1455 	 * (and presumably, FIFO is not half-full) we should write *two*
1456 	 * packets before updating TXCSR; other docs disagree...
1457 	 */
1458 	if (length > qh->maxpacket)
1459 		length = qh->maxpacket;
1460 	/* Unmap the buffer so that CPU can use it */
1461 	usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1462 
1463 	/*
1464 	 * We need to map sg if the transfer_buffer is
1465 	 * NULL.
1466 	 */
1467 	if (!urb->transfer_buffer)
1468 		qh->use_sg = true;
1469 
1470 	if (qh->use_sg) {
1471 		/* sg_miter_start is already done in musb_ep_program */
1472 		if (!sg_miter_next(&qh->sg_miter)) {
1473 			dev_err(musb->controller, "error: sg list empty\n");
1474 			sg_miter_stop(&qh->sg_miter);
1475 			status = -EINVAL;
1476 			goto done;
1477 		}
1478 		urb->transfer_buffer = qh->sg_miter.addr;
1479 		length = min_t(u32, length, qh->sg_miter.length);
1480 		musb_write_fifo(hw_ep, length, urb->transfer_buffer);
1481 		qh->sg_miter.consumed = length;
1482 		sg_miter_stop(&qh->sg_miter);
1483 	} else {
1484 		musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1485 	}
1486 
1487 	qh->segsize = length;
1488 
1489 	if (qh->use_sg) {
1490 		if (offset + length >= urb->transfer_buffer_length)
1491 			qh->use_sg = false;
1492 	}
1493 
1494 	musb_ep_select(mbase, epnum);
1495 	musb_writew(epio, MUSB_TXCSR,
1496 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1497 }
1498 
1499 
1500 #ifdef CONFIG_USB_INVENTRA_DMA
1501 
1502 /* Host side RX (IN) using Mentor DMA works as follows:
1503 	submit_urb ->
1504 		- if queue was empty, ProgramEndpoint
1505 		- first IN token is sent out (by setting ReqPkt)
1506 	LinuxIsr -> RxReady()
1507 	/\	=> first packet is received
1508 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1509 	|		-> DMA Isr (transfer complete) -> RxReady()
1510 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1511 	|		    - if urb not complete, send next IN token (ReqPkt)
1512 	|			   |		else complete urb.
1513 	|			   |
1514 	---------------------------
1515  *
1516  * Nuances of mode 1:
1517  *	For short packets, no ack (+RxPktRdy) is sent automatically
1518  *	(even if AutoClear is ON)
1519  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1520  *	automatically => major problem, as collecting the next packet becomes
1521  *	difficult. Hence mode 1 is not used.
1522  *
1523  * REVISIT
1524  *	All we care about at this driver level is that
1525  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1526  *       (b) termination conditions are: short RX, or buffer full;
1527  *       (c) fault modes include
1528  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1529  *             (and that endpoint's dma queue stops immediately)
1530  *           - overflow (full, PLUS more bytes in the terminal packet)
1531  *
1532  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1533  *	thus be a great candidate for using mode 1 ... for all but the
1534  *	last packet of one URB's transfer.
1535  */
1536 
1537 #endif
1538 
1539 /*
1540  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1541  * and high-bandwidth IN transfer cases.
1542  */
1543 void musb_host_rx(struct musb *musb, u8 epnum)
1544 {
1545 	struct urb		*urb;
1546 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1547 	void __iomem		*epio = hw_ep->regs;
1548 	struct musb_qh		*qh = hw_ep->in_qh;
1549 	size_t			xfer_len;
1550 	void __iomem		*mbase = musb->mregs;
1551 	int			pipe;
1552 	u16			rx_csr, val;
1553 	bool			iso_err = false;
1554 	bool			done = false;
1555 	u32			status;
1556 	struct dma_channel	*dma;
1557 	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
1558 
1559 	musb_ep_select(mbase, epnum);
1560 
1561 	urb = next_urb(qh);
1562 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1563 	status = 0;
1564 	xfer_len = 0;
1565 
1566 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1567 	val = rx_csr;
1568 
1569 	if (unlikely(!urb)) {
1570 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1571 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1572 		 * with fifo full.  (Only with DMA??)
1573 		 */
1574 		dev_dbg(musb->controller, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
1575 			musb_readw(epio, MUSB_RXCOUNT));
1576 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1577 		return;
1578 	}
1579 
1580 	pipe = urb->pipe;
1581 
1582 	dev_dbg(musb->controller, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
1583 		epnum, rx_csr, urb->actual_length,
1584 		dma ? dma->actual_len : 0);
1585 
1586 	/* check for errors, concurrent stall & unlink is not really
1587 	 * handled yet! */
1588 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1589 		dev_dbg(musb->controller, "RX end %d STALL\n", epnum);
1590 
1591 		/* stall; record URB status */
1592 		status = -EPIPE;
1593 
1594 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1595 		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
1596 
1597 		status = -EPROTO;
1598 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1599 
1600 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1601 
1602 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1603 			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
1604 
1605 			/* NOTE: NAKing is *NOT* an error, so we want to
1606 			 * continue.  Except ... if there's a request for
1607 			 * another QH, use that instead of starving it.
1608 			 *
1609 			 * Devices like Ethernet and serial adapters keep
1610 			 * reads posted at all times, which will starve
1611 			 * other devices without this logic.
1612 			 */
1613 			if (usb_pipebulk(urb->pipe)
1614 					&& qh->mux == 1
1615 					&& !list_is_singular(&musb->in_bulk)) {
1616 				musb_bulk_nak_timeout(musb, hw_ep, 1);
1617 				return;
1618 			}
1619 			musb_ep_select(mbase, epnum);
1620 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1621 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1622 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1623 
1624 			goto finish;
1625 		} else {
1626 			dev_dbg(musb->controller, "RX end %d ISO data error\n", epnum);
1627 			/* packet error reported later */
1628 			iso_err = true;
1629 		}
1630 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1631 		dev_dbg(musb->controller, "end %d high bandwidth incomplete ISO packet RX\n",
1632 				epnum);
1633 		status = -EPROTO;
1634 	}
1635 
1636 	/* faults abort the transfer */
1637 	if (status) {
1638 		/* clean up dma and collect transfer count */
1639 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1640 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1641 			(void) musb->dma_controller->channel_abort(dma);
1642 			xfer_len = dma->actual_len;
1643 		}
1644 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1645 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1646 		done = true;
1647 		goto finish;
1648 	}
1649 
1650 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1651 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1652 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1653 		goto finish;
1654 	}
1655 
1656 	/* thorough shutdown for now ... given more precise fault handling
1657 	 * and better queueing support, we might keep a DMA pipeline going
1658 	 * while processing this irq for earlier completions.
1659 	 */
1660 
1661 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1662 
1663 #if !defined(CONFIG_USB_INVENTRA_DMA) && !defined(CONFIG_USB_UX500_DMA)
1664 	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
1665 		/* REVISIT this happened for a while on some short reads...
1666 		 * the cleanup still needs investigation... looks bad...
1667 		 * and also duplicates dma cleanup code above ... plus,
1668 		 * shouldn't this be the "half full" double buffer case?
1669 		 */
1670 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1671 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1672 			(void) musb->dma_controller->channel_abort(dma);
1673 			xfer_len = dma->actual_len;
1674 			done = true;
1675 		}
1676 
1677 		dev_dbg(musb->controller, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
1678 				xfer_len, dma ? ", dma" : "");
1679 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1680 
1681 		musb_ep_select(mbase, epnum);
1682 		musb_writew(epio, MUSB_RXCSR,
1683 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1684 	}
1685 #endif
1686 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1687 		xfer_len = dma->actual_len;
1688 
1689 		val &= ~(MUSB_RXCSR_DMAENAB
1690 			| MUSB_RXCSR_H_AUTOREQ
1691 			| MUSB_RXCSR_AUTOCLEAR
1692 			| MUSB_RXCSR_RXPKTRDY);
1693 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1694 
1695 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
1696 		if (usb_pipeisoc(pipe)) {
1697 			struct usb_iso_packet_descriptor *d;
1698 
1699 			d = urb->iso_frame_desc + qh->iso_idx;
1700 			d->actual_length = xfer_len;
1701 
1702 			/* even if there was an error, we did the dma
1703 			 * for iso_frame_desc->length
1704 			 */
1705 			if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1706 				d->status = 0;
1707 
1708 			if (++qh->iso_idx >= urb->number_of_packets)
1709 				done = true;
1710 			else
1711 				done = false;
1712 
1713 		} else  {
1714 		/* done if urb buffer is full or short packet is recd */
1715 		done = (urb->actual_length + xfer_len >=
1716 				urb->transfer_buffer_length
1717 			|| dma->actual_len < qh->maxpacket);
1718 		}
1719 
1720 		/* send IN token for next packet, without AUTOREQ */
1721 		if (!done) {
1722 			val |= MUSB_RXCSR_H_REQPKT;
1723 			musb_writew(epio, MUSB_RXCSR,
1724 				MUSB_RXCSR_H_WZC_BITS | val);
1725 		}
1726 
1727 		dev_dbg(musb->controller, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
1728 			done ? "off" : "reset",
1729 			musb_readw(epio, MUSB_RXCSR),
1730 			musb_readw(epio, MUSB_RXCOUNT));
1731 #else
1732 		done = true;
1733 #endif
1734 	} else if (urb->status == -EINPROGRESS) {
1735 		/* if no errors, be sure a packet is ready for unloading */
1736 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1737 			status = -EPROTO;
1738 			ERR("Rx interrupt with no errors or packet!\n");
1739 
1740 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1741 
1742 /* SCRUB (RX) */
1743 			/* do the proper sequence to abort the transfer */
1744 			musb_ep_select(mbase, epnum);
1745 			val &= ~MUSB_RXCSR_H_REQPKT;
1746 			musb_writew(epio, MUSB_RXCSR, val);
1747 			goto finish;
1748 		}
1749 
1750 		/* we are expecting IN packets */
1751 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
1752 		if (dma) {
1753 			struct dma_controller	*c;
1754 			u16			rx_count;
1755 			int			ret, length;
1756 			dma_addr_t		buf;
1757 
1758 			rx_count = musb_readw(epio, MUSB_RXCOUNT);
1759 
1760 			dev_dbg(musb->controller, "RX%d count %d, buffer 0x%llx len %d/%d\n",
1761 					epnum, rx_count,
1762 					(unsigned long long) urb->transfer_dma
1763 					+ urb->actual_length,
1764 					qh->offset,
1765 					urb->transfer_buffer_length);
1766 
1767 			c = musb->dma_controller;
1768 
1769 			if (usb_pipeisoc(pipe)) {
1770 				int d_status = 0;
1771 				struct usb_iso_packet_descriptor *d;
1772 
1773 				d = urb->iso_frame_desc + qh->iso_idx;
1774 
1775 				if (iso_err) {
1776 					d_status = -EILSEQ;
1777 					urb->error_count++;
1778 				}
1779 				if (rx_count > d->length) {
1780 					if (d_status == 0) {
1781 						d_status = -EOVERFLOW;
1782 						urb->error_count++;
1783 					}
1784 					dev_dbg(musb->controller, "** OVERFLOW %d into %d\n",\
1785 					    rx_count, d->length);
1786 
1787 					length = d->length;
1788 				} else
1789 					length = rx_count;
1790 				d->status = d_status;
1791 				buf = urb->transfer_dma + d->offset;
1792 			} else {
1793 				length = rx_count;
1794 				buf = urb->transfer_dma +
1795 						urb->actual_length;
1796 			}
1797 
1798 			dma->desired_mode = 0;
1799 #ifdef USE_MODE1
1800 			/* because of the issue below, mode 1 will
1801 			 * only rarely behave with correct semantics.
1802 			 */
1803 			if ((urb->transfer_flags &
1804 						URB_SHORT_NOT_OK)
1805 				&& (urb->transfer_buffer_length -
1806 						urb->actual_length)
1807 					> qh->maxpacket)
1808 				dma->desired_mode = 1;
1809 			if (rx_count < hw_ep->max_packet_sz_rx) {
1810 				length = rx_count;
1811 				dma->desired_mode = 0;
1812 			} else {
1813 				length = urb->transfer_buffer_length;
1814 			}
1815 #endif
1816 
1817 /* Disadvantage of using mode 1:
1818  *	It's basically usable only for mass storage class; essentially all
1819  *	other protocols also terminate transfers on short packets.
1820  *
1821  * Details:
1822  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1823  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1824  *	to use the extra IN token to grab the last packet using mode 0, then
1825  *	the problem is that you cannot be sure when the device will send the
1826  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1827  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1828  *	transfer, while sometimes it is recd just a little late so that if you
1829  *	try to configure for mode 0 soon after the mode 1 transfer is
1830  *	completed, you will find rxcount 0. Okay, so you might think why not
1831  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1832  */
1833 
1834 			val = musb_readw(epio, MUSB_RXCSR);
1835 			val &= ~MUSB_RXCSR_H_REQPKT;
1836 
1837 			if (dma->desired_mode == 0)
1838 				val &= ~MUSB_RXCSR_H_AUTOREQ;
1839 			else
1840 				val |= MUSB_RXCSR_H_AUTOREQ;
1841 			val |= MUSB_RXCSR_DMAENAB;
1842 
1843 			/* autoclear shouldn't be set in high bandwidth */
1844 			if (qh->hb_mult == 1)
1845 				val |= MUSB_RXCSR_AUTOCLEAR;
1846 
1847 			musb_writew(epio, MUSB_RXCSR,
1848 				MUSB_RXCSR_H_WZC_BITS | val);
1849 
1850 			/* REVISIT if when actual_length != 0,
1851 			 * transfer_buffer_length needs to be
1852 			 * adjusted first...
1853 			 */
1854 			ret = c->channel_program(
1855 				dma, qh->maxpacket,
1856 				dma->desired_mode, buf, length);
1857 
1858 			if (!ret) {
1859 				c->channel_release(dma);
1860 				hw_ep->rx_channel = NULL;
1861 				dma = NULL;
1862 				val = musb_readw(epio, MUSB_RXCSR);
1863 				val &= ~(MUSB_RXCSR_DMAENAB
1864 					| MUSB_RXCSR_H_AUTOREQ
1865 					| MUSB_RXCSR_AUTOCLEAR);
1866 				musb_writew(epio, MUSB_RXCSR, val);
1867 			}
1868 		}
1869 #endif	/* Mentor DMA */
1870 
1871 		if (!dma) {
1872 			unsigned int received_len;
1873 
1874 			/* Unmap the buffer so that CPU can use it */
1875 			usb_hcd_unmap_urb_for_dma(musb->hcd, urb);
1876 
1877 			/*
1878 			 * We need to map sg if the transfer_buffer is
1879 			 * NULL.
1880 			 */
1881 			if (!urb->transfer_buffer) {
1882 				qh->use_sg = true;
1883 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
1884 						sg_flags);
1885 			}
1886 
1887 			if (qh->use_sg) {
1888 				if (!sg_miter_next(&qh->sg_miter)) {
1889 					dev_err(musb->controller, "error: sg list empty\n");
1890 					sg_miter_stop(&qh->sg_miter);
1891 					status = -EINVAL;
1892 					done = true;
1893 					goto finish;
1894 				}
1895 				urb->transfer_buffer = qh->sg_miter.addr;
1896 				received_len = urb->actual_length;
1897 				qh->offset = 0x0;
1898 				done = musb_host_packet_rx(musb, urb, epnum,
1899 						iso_err);
1900 				/* Calculate the number of bytes received */
1901 				received_len = urb->actual_length -
1902 					received_len;
1903 				qh->sg_miter.consumed = received_len;
1904 				sg_miter_stop(&qh->sg_miter);
1905 			} else {
1906 				done = musb_host_packet_rx(musb, urb,
1907 						epnum, iso_err);
1908 			}
1909 			dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
1910 		}
1911 	}
1912 
1913 finish:
1914 	urb->actual_length += xfer_len;
1915 	qh->offset += xfer_len;
1916 	if (done) {
1917 		if (qh->use_sg)
1918 			qh->use_sg = false;
1919 
1920 		if (urb->status == -EINPROGRESS)
1921 			urb->status = status;
1922 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1923 	}
1924 }
1925 
1926 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1927  * the software schedule associates multiple such nodes with a given
1928  * host side hardware endpoint + direction; scheduling may activate
1929  * that hardware endpoint.
1930  */
1931 static int musb_schedule(
1932 	struct musb		*musb,
1933 	struct musb_qh		*qh,
1934 	int			is_in)
1935 {
1936 	int			idle;
1937 	int			best_diff;
1938 	int			best_end, epnum;
1939 	struct musb_hw_ep	*hw_ep = NULL;
1940 	struct list_head	*head = NULL;
1941 	u8			toggle;
1942 	u8			txtype;
1943 	struct urb		*urb = next_urb(qh);
1944 
1945 	/* use fixed hardware for control and bulk */
1946 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1947 		head = &musb->control;
1948 		hw_ep = musb->control_ep;
1949 		goto success;
1950 	}
1951 
1952 	/* else, periodic transfers get muxed to other endpoints */
1953 
1954 	/*
1955 	 * We know this qh hasn't been scheduled, so all we need to do
1956 	 * is choose which hardware endpoint to put it on ...
1957 	 *
1958 	 * REVISIT what we really want here is a regular schedule tree
1959 	 * like e.g. OHCI uses.
1960 	 */
1961 	best_diff = 4096;
1962 	best_end = -1;
1963 
1964 	for (epnum = 1, hw_ep = musb->endpoints + 1;
1965 			epnum < musb->nr_endpoints;
1966 			epnum++, hw_ep++) {
1967 		int	diff;
1968 
1969 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
1970 			continue;
1971 
1972 		if (hw_ep == musb->bulk_ep)
1973 			continue;
1974 
1975 		if (is_in)
1976 			diff = hw_ep->max_packet_sz_rx;
1977 		else
1978 			diff = hw_ep->max_packet_sz_tx;
1979 		diff -= (qh->maxpacket * qh->hb_mult);
1980 
1981 		if (diff >= 0 && best_diff > diff) {
1982 
1983 			/*
1984 			 * Mentor controller has a bug in that if we schedule
1985 			 * a BULK Tx transfer on an endpoint that had earlier
1986 			 * handled ISOC then the BULK transfer has to start on
1987 			 * a zero toggle.  If the BULK transfer starts on a 1
1988 			 * toggle then this transfer will fail as the mentor
1989 			 * controller starts the Bulk transfer on a 0 toggle
1990 			 * irrespective of the programming of the toggle bits
1991 			 * in the TXCSR register.  Check for this condition
1992 			 * while allocating the EP for a Tx Bulk transfer.  If
1993 			 * so skip this EP.
1994 			 */
1995 			hw_ep = musb->endpoints + epnum;
1996 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
1997 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
1998 					>> 4) & 0x3;
1999 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
2000 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
2001 				continue;
2002 
2003 			best_diff = diff;
2004 			best_end = epnum;
2005 		}
2006 	}
2007 	/* use bulk reserved ep1 if no other ep is free */
2008 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
2009 		hw_ep = musb->bulk_ep;
2010 		if (is_in)
2011 			head = &musb->in_bulk;
2012 		else
2013 			head = &musb->out_bulk;
2014 
2015 		/* Enable bulk RX/TX NAK timeout scheme when bulk requests are
2016 		 * multiplexed.  This scheme doen't work in high speed to full
2017 		 * speed scenario as NAK interrupts are not coming from a
2018 		 * full speed device connected to a high speed device.
2019 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
2020 		 * 4 (8 frame or 8ms) for FS device.
2021 		 */
2022 		if (qh->dev)
2023 			qh->intv_reg =
2024 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
2025 		goto success;
2026 	} else if (best_end < 0) {
2027 		return -ENOSPC;
2028 	}
2029 
2030 	idle = 1;
2031 	qh->mux = 0;
2032 	hw_ep = musb->endpoints + best_end;
2033 	dev_dbg(musb->controller, "qh %p periodic slot %d\n", qh, best_end);
2034 success:
2035 	if (head) {
2036 		idle = list_empty(head);
2037 		list_add_tail(&qh->ring, head);
2038 		qh->mux = 1;
2039 	}
2040 	qh->hw_ep = hw_ep;
2041 	qh->hep->hcpriv = qh;
2042 	if (idle)
2043 		musb_start_urb(musb, is_in, qh);
2044 	return 0;
2045 }
2046 
2047 static int musb_urb_enqueue(
2048 	struct usb_hcd			*hcd,
2049 	struct urb			*urb,
2050 	gfp_t				mem_flags)
2051 {
2052 	unsigned long			flags;
2053 	struct musb			*musb = hcd_to_musb(hcd);
2054 	struct usb_host_endpoint	*hep = urb->ep;
2055 	struct musb_qh			*qh;
2056 	struct usb_endpoint_descriptor	*epd = &hep->desc;
2057 	int				ret;
2058 	unsigned			type_reg;
2059 	unsigned			interval;
2060 
2061 	/* host role must be active */
2062 	if (!is_host_active(musb) || !musb->is_active)
2063 		return -ENODEV;
2064 
2065 	spin_lock_irqsave(&musb->lock, flags);
2066 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
2067 	qh = ret ? NULL : hep->hcpriv;
2068 	if (qh)
2069 		urb->hcpriv = qh;
2070 	spin_unlock_irqrestore(&musb->lock, flags);
2071 
2072 	/* DMA mapping was already done, if needed, and this urb is on
2073 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
2074 	 * scheduled onto a live qh.
2075 	 *
2076 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
2077 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
2078 	 * except for the first urb queued after a config change.
2079 	 */
2080 	if (qh || ret)
2081 		return ret;
2082 
2083 	/* Allocate and initialize qh, minimizing the work done each time
2084 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
2085 	 *
2086 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
2087 	 * for bugs in other kernel code to break this driver...
2088 	 */
2089 	qh = kzalloc(sizeof *qh, mem_flags);
2090 	if (!qh) {
2091 		spin_lock_irqsave(&musb->lock, flags);
2092 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2093 		spin_unlock_irqrestore(&musb->lock, flags);
2094 		return -ENOMEM;
2095 	}
2096 
2097 	qh->hep = hep;
2098 	qh->dev = urb->dev;
2099 	INIT_LIST_HEAD(&qh->ring);
2100 	qh->is_ready = 1;
2101 
2102 	qh->maxpacket = usb_endpoint_maxp(epd);
2103 	qh->type = usb_endpoint_type(epd);
2104 
2105 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
2106 	 * Some musb cores don't support high bandwidth ISO transfers; and
2107 	 * we don't (yet!) support high bandwidth interrupt transfers.
2108 	 */
2109 	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
2110 	if (qh->hb_mult > 1) {
2111 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
2112 
2113 		if (ok)
2114 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
2115 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
2116 		if (!ok) {
2117 			ret = -EMSGSIZE;
2118 			goto done;
2119 		}
2120 		qh->maxpacket &= 0x7ff;
2121 	}
2122 
2123 	qh->epnum = usb_endpoint_num(epd);
2124 
2125 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
2126 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
2127 
2128 	/* precompute rxtype/txtype/type0 register */
2129 	type_reg = (qh->type << 4) | qh->epnum;
2130 	switch (urb->dev->speed) {
2131 	case USB_SPEED_LOW:
2132 		type_reg |= 0xc0;
2133 		break;
2134 	case USB_SPEED_FULL:
2135 		type_reg |= 0x80;
2136 		break;
2137 	default:
2138 		type_reg |= 0x40;
2139 	}
2140 	qh->type_reg = type_reg;
2141 
2142 	/* Precompute RXINTERVAL/TXINTERVAL register */
2143 	switch (qh->type) {
2144 	case USB_ENDPOINT_XFER_INT:
2145 		/*
2146 		 * Full/low speeds use the  linear encoding,
2147 		 * high speed uses the logarithmic encoding.
2148 		 */
2149 		if (urb->dev->speed <= USB_SPEED_FULL) {
2150 			interval = max_t(u8, epd->bInterval, 1);
2151 			break;
2152 		}
2153 		/* FALLTHROUGH */
2154 	case USB_ENDPOINT_XFER_ISOC:
2155 		/* ISO always uses logarithmic encoding */
2156 		interval = min_t(u8, epd->bInterval, 16);
2157 		break;
2158 	default:
2159 		/* REVISIT we actually want to use NAK limits, hinting to the
2160 		 * transfer scheduling logic to try some other qh, e.g. try
2161 		 * for 2 msec first:
2162 		 *
2163 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2164 		 *
2165 		 * The downside of disabling this is that transfer scheduling
2166 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2167 		 * peripheral could make that hurt.  That's perfectly normal
2168 		 * for reads from network or serial adapters ... so we have
2169 		 * partial NAKlimit support for bulk RX.
2170 		 *
2171 		 * The upside of disabling it is simpler transfer scheduling.
2172 		 */
2173 		interval = 0;
2174 	}
2175 	qh->intv_reg = interval;
2176 
2177 	/* precompute addressing for external hub/tt ports */
2178 	if (musb->is_multipoint) {
2179 		struct usb_device	*parent = urb->dev->parent;
2180 
2181 		if (parent != hcd->self.root_hub) {
2182 			qh->h_addr_reg = (u8) parent->devnum;
2183 
2184 			/* set up tt info if needed */
2185 			if (urb->dev->tt) {
2186 				qh->h_port_reg = (u8) urb->dev->ttport;
2187 				if (urb->dev->tt->hub)
2188 					qh->h_addr_reg =
2189 						(u8) urb->dev->tt->hub->devnum;
2190 				if (urb->dev->tt->multi)
2191 					qh->h_addr_reg |= 0x80;
2192 			}
2193 		}
2194 	}
2195 
2196 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2197 	 * until we get real dma queues (with an entry for each urb/buffer),
2198 	 * we only have work to do in the former case.
2199 	 */
2200 	spin_lock_irqsave(&musb->lock, flags);
2201 	if (hep->hcpriv || !next_urb(qh)) {
2202 		/* some concurrent activity submitted another urb to hep...
2203 		 * odd, rare, error prone, but legal.
2204 		 */
2205 		kfree(qh);
2206 		qh = NULL;
2207 		ret = 0;
2208 	} else
2209 		ret = musb_schedule(musb, qh,
2210 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2211 
2212 	if (ret == 0) {
2213 		urb->hcpriv = qh;
2214 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2215 		 * musb_start_urb(), but otherwise only konicawc cares ...
2216 		 */
2217 	}
2218 	spin_unlock_irqrestore(&musb->lock, flags);
2219 
2220 done:
2221 	if (ret != 0) {
2222 		spin_lock_irqsave(&musb->lock, flags);
2223 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2224 		spin_unlock_irqrestore(&musb->lock, flags);
2225 		kfree(qh);
2226 	}
2227 	return ret;
2228 }
2229 
2230 
2231 /*
2232  * abort a transfer that's at the head of a hardware queue.
2233  * called with controller locked, irqs blocked
2234  * that hardware queue advances to the next transfer, unless prevented
2235  */
2236 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2237 {
2238 	struct musb_hw_ep	*ep = qh->hw_ep;
2239 	struct musb		*musb = ep->musb;
2240 	void __iomem		*epio = ep->regs;
2241 	unsigned		hw_end = ep->epnum;
2242 	void __iomem		*regs = ep->musb->mregs;
2243 	int			is_in = usb_pipein(urb->pipe);
2244 	int			status = 0;
2245 	u16			csr;
2246 
2247 	musb_ep_select(regs, hw_end);
2248 
2249 	if (is_dma_capable()) {
2250 		struct dma_channel	*dma;
2251 
2252 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2253 		if (dma) {
2254 			status = ep->musb->dma_controller->channel_abort(dma);
2255 			dev_dbg(musb->controller,
2256 				"abort %cX%d DMA for urb %p --> %d\n",
2257 				is_in ? 'R' : 'T', ep->epnum,
2258 				urb, status);
2259 			urb->actual_length += dma->actual_len;
2260 		}
2261 	}
2262 
2263 	/* turn off DMA requests, discard state, stop polling ... */
2264 	if (ep->epnum && is_in) {
2265 		/* giveback saves bulk toggle */
2266 		csr = musb_h_flush_rxfifo(ep, 0);
2267 
2268 		/* REVISIT we still get an irq; should likely clear the
2269 		 * endpoint's irq status here to avoid bogus irqs.
2270 		 * clearing that status is platform-specific...
2271 		 */
2272 	} else if (ep->epnum) {
2273 		musb_h_tx_flush_fifo(ep);
2274 		csr = musb_readw(epio, MUSB_TXCSR);
2275 		csr &= ~(MUSB_TXCSR_AUTOSET
2276 			| MUSB_TXCSR_DMAENAB
2277 			| MUSB_TXCSR_H_RXSTALL
2278 			| MUSB_TXCSR_H_NAKTIMEOUT
2279 			| MUSB_TXCSR_H_ERROR
2280 			| MUSB_TXCSR_TXPKTRDY);
2281 		musb_writew(epio, MUSB_TXCSR, csr);
2282 		/* REVISIT may need to clear FLUSHFIFO ... */
2283 		musb_writew(epio, MUSB_TXCSR, csr);
2284 		/* flush cpu writebuffer */
2285 		csr = musb_readw(epio, MUSB_TXCSR);
2286 	} else  {
2287 		musb_h_ep0_flush_fifo(ep);
2288 	}
2289 	if (status == 0)
2290 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2291 	return status;
2292 }
2293 
2294 static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
2295 {
2296 	struct musb		*musb = hcd_to_musb(hcd);
2297 	struct musb_qh		*qh;
2298 	unsigned long		flags;
2299 	int			is_in  = usb_pipein(urb->pipe);
2300 	int			ret;
2301 
2302 	dev_dbg(musb->controller, "urb=%p, dev%d ep%d%s\n", urb,
2303 			usb_pipedevice(urb->pipe),
2304 			usb_pipeendpoint(urb->pipe),
2305 			is_in ? "in" : "out");
2306 
2307 	spin_lock_irqsave(&musb->lock, flags);
2308 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2309 	if (ret)
2310 		goto done;
2311 
2312 	qh = urb->hcpriv;
2313 	if (!qh)
2314 		goto done;
2315 
2316 	/*
2317 	 * Any URB not actively programmed into endpoint hardware can be
2318 	 * immediately given back; that's any URB not at the head of an
2319 	 * endpoint queue, unless someday we get real DMA queues.  And even
2320 	 * if it's at the head, it might not be known to the hardware...
2321 	 *
2322 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2323 	 * has already been updated.  This is a synchronous abort; it'd be
2324 	 * OK to hold off until after some IRQ, though.
2325 	 *
2326 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2327 	 */
2328 	if (!qh->is_ready
2329 			|| urb->urb_list.prev != &qh->hep->urb_list
2330 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2331 		int	ready = qh->is_ready;
2332 
2333 		qh->is_ready = 0;
2334 		musb_giveback(musb, urb, 0);
2335 		qh->is_ready = ready;
2336 
2337 		/* If nothing else (usually musb_giveback) is using it
2338 		 * and its URB list has emptied, recycle this qh.
2339 		 */
2340 		if (ready && list_empty(&qh->hep->urb_list)) {
2341 			qh->hep->hcpriv = NULL;
2342 			list_del(&qh->ring);
2343 			kfree(qh);
2344 		}
2345 	} else
2346 		ret = musb_cleanup_urb(urb, qh);
2347 done:
2348 	spin_unlock_irqrestore(&musb->lock, flags);
2349 	return ret;
2350 }
2351 
2352 /* disable an endpoint */
2353 static void
2354 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2355 {
2356 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2357 	unsigned long		flags;
2358 	struct musb		*musb = hcd_to_musb(hcd);
2359 	struct musb_qh		*qh;
2360 	struct urb		*urb;
2361 
2362 	spin_lock_irqsave(&musb->lock, flags);
2363 
2364 	qh = hep->hcpriv;
2365 	if (qh == NULL)
2366 		goto exit;
2367 
2368 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2369 
2370 	/* Kick the first URB off the hardware, if needed */
2371 	qh->is_ready = 0;
2372 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2373 		urb = next_urb(qh);
2374 
2375 		/* make software (then hardware) stop ASAP */
2376 		if (!urb->unlinked)
2377 			urb->status = -ESHUTDOWN;
2378 
2379 		/* cleanup */
2380 		musb_cleanup_urb(urb, qh);
2381 
2382 		/* Then nuke all the others ... and advance the
2383 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2384 		 */
2385 		while (!list_empty(&hep->urb_list)) {
2386 			urb = next_urb(qh);
2387 			urb->status = -ESHUTDOWN;
2388 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2389 		}
2390 	} else {
2391 		/* Just empty the queue; the hardware is busy with
2392 		 * other transfers, and since !qh->is_ready nothing
2393 		 * will activate any of these as it advances.
2394 		 */
2395 		while (!list_empty(&hep->urb_list))
2396 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2397 
2398 		hep->hcpriv = NULL;
2399 		list_del(&qh->ring);
2400 		kfree(qh);
2401 	}
2402 exit:
2403 	spin_unlock_irqrestore(&musb->lock, flags);
2404 }
2405 
2406 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2407 {
2408 	struct musb	*musb = hcd_to_musb(hcd);
2409 
2410 	return musb_readw(musb->mregs, MUSB_FRAME);
2411 }
2412 
2413 static int musb_h_start(struct usb_hcd *hcd)
2414 {
2415 	struct musb	*musb = hcd_to_musb(hcd);
2416 
2417 	/* NOTE: musb_start() is called when the hub driver turns
2418 	 * on port power, or when (OTG) peripheral starts.
2419 	 */
2420 	hcd->state = HC_STATE_RUNNING;
2421 	musb->port1_status = 0;
2422 	return 0;
2423 }
2424 
2425 static void musb_h_stop(struct usb_hcd *hcd)
2426 {
2427 	musb_stop(hcd_to_musb(hcd));
2428 	hcd->state = HC_STATE_HALT;
2429 }
2430 
2431 static int musb_bus_suspend(struct usb_hcd *hcd)
2432 {
2433 	struct musb	*musb = hcd_to_musb(hcd);
2434 	u8		devctl;
2435 
2436 	if (!is_host_active(musb))
2437 		return 0;
2438 
2439 	switch (musb->xceiv->state) {
2440 	case OTG_STATE_A_SUSPEND:
2441 		return 0;
2442 	case OTG_STATE_A_WAIT_VRISE:
2443 		/* ID could be grounded even if there's no device
2444 		 * on the other end of the cable.  NOTE that the
2445 		 * A_WAIT_VRISE timers are messy with MUSB...
2446 		 */
2447 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2448 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2449 			musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2450 		break;
2451 	default:
2452 		break;
2453 	}
2454 
2455 	if (musb->is_active) {
2456 		WARNING("trying to suspend as %s while active\n",
2457 				usb_otg_state_string(musb->xceiv->state));
2458 		return -EBUSY;
2459 	} else
2460 		return 0;
2461 }
2462 
2463 static int musb_bus_resume(struct usb_hcd *hcd)
2464 {
2465 	/* resuming child port does the work */
2466 	return 0;
2467 }
2468 
2469 #ifndef CONFIG_MUSB_PIO_ONLY
2470 
2471 #define MUSB_USB_DMA_ALIGN 4
2472 
2473 struct musb_temp_buffer {
2474 	void *kmalloc_ptr;
2475 	void *old_xfer_buffer;
2476 	u8 data[0];
2477 };
2478 
2479 static void musb_free_temp_buffer(struct urb *urb)
2480 {
2481 	enum dma_data_direction dir;
2482 	struct musb_temp_buffer *temp;
2483 
2484 	if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
2485 		return;
2486 
2487 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2488 
2489 	temp = container_of(urb->transfer_buffer, struct musb_temp_buffer,
2490 			    data);
2491 
2492 	if (dir == DMA_FROM_DEVICE) {
2493 		memcpy(temp->old_xfer_buffer, temp->data,
2494 		       urb->transfer_buffer_length);
2495 	}
2496 	urb->transfer_buffer = temp->old_xfer_buffer;
2497 	kfree(temp->kmalloc_ptr);
2498 
2499 	urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
2500 }
2501 
2502 static int musb_alloc_temp_buffer(struct urb *urb, gfp_t mem_flags)
2503 {
2504 	enum dma_data_direction dir;
2505 	struct musb_temp_buffer *temp;
2506 	void *kmalloc_ptr;
2507 	size_t kmalloc_size;
2508 
2509 	if (urb->num_sgs || urb->sg ||
2510 	    urb->transfer_buffer_length == 0 ||
2511 	    !((uintptr_t)urb->transfer_buffer & (MUSB_USB_DMA_ALIGN - 1)))
2512 		return 0;
2513 
2514 	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
2515 
2516 	/* Allocate a buffer with enough padding for alignment */
2517 	kmalloc_size = urb->transfer_buffer_length +
2518 		sizeof(struct musb_temp_buffer) + MUSB_USB_DMA_ALIGN - 1;
2519 
2520 	kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
2521 	if (!kmalloc_ptr)
2522 		return -ENOMEM;
2523 
2524 	/* Position our struct temp_buffer such that data is aligned */
2525 	temp = PTR_ALIGN(kmalloc_ptr, MUSB_USB_DMA_ALIGN);
2526 
2527 
2528 	temp->kmalloc_ptr = kmalloc_ptr;
2529 	temp->old_xfer_buffer = urb->transfer_buffer;
2530 	if (dir == DMA_TO_DEVICE)
2531 		memcpy(temp->data, urb->transfer_buffer,
2532 		       urb->transfer_buffer_length);
2533 	urb->transfer_buffer = temp->data;
2534 
2535 	urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
2536 
2537 	return 0;
2538 }
2539 
2540 static int musb_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
2541 				      gfp_t mem_flags)
2542 {
2543 	struct musb	*musb = hcd_to_musb(hcd);
2544 	int ret;
2545 
2546 	/*
2547 	 * The DMA engine in RTL1.8 and above cannot handle
2548 	 * DMA addresses that are not aligned to a 4 byte boundary.
2549 	 * For such engine implemented (un)map_urb_for_dma hooks.
2550 	 * Do not use these hooks for RTL<1.8
2551 	 */
2552 	if (musb->hwvers < MUSB_HWVERS_1800)
2553 		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2554 
2555 	ret = musb_alloc_temp_buffer(urb, mem_flags);
2556 	if (ret)
2557 		return ret;
2558 
2559 	ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
2560 	if (ret)
2561 		musb_free_temp_buffer(urb);
2562 
2563 	return ret;
2564 }
2565 
2566 static void musb_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
2567 {
2568 	struct musb	*musb = hcd_to_musb(hcd);
2569 
2570 	usb_hcd_unmap_urb_for_dma(hcd, urb);
2571 
2572 	/* Do not use this hook for RTL<1.8 (see description above) */
2573 	if (musb->hwvers < MUSB_HWVERS_1800)
2574 		return;
2575 
2576 	musb_free_temp_buffer(urb);
2577 }
2578 #endif /* !CONFIG_MUSB_PIO_ONLY */
2579 
2580 static const struct hc_driver musb_hc_driver = {
2581 	.description		= "musb-hcd",
2582 	.product_desc		= "MUSB HDRC host driver",
2583 	.hcd_priv_size		= sizeof(struct musb *),
2584 	.flags			= HCD_USB2 | HCD_MEMORY,
2585 
2586 	/* not using irq handler or reset hooks from usbcore, since
2587 	 * those must be shared with peripheral code for OTG configs
2588 	 */
2589 
2590 	.start			= musb_h_start,
2591 	.stop			= musb_h_stop,
2592 
2593 	.get_frame_number	= musb_h_get_frame_number,
2594 
2595 	.urb_enqueue		= musb_urb_enqueue,
2596 	.urb_dequeue		= musb_urb_dequeue,
2597 	.endpoint_disable	= musb_h_disable,
2598 
2599 #ifndef CONFIG_MUSB_PIO_ONLY
2600 	.map_urb_for_dma	= musb_map_urb_for_dma,
2601 	.unmap_urb_for_dma	= musb_unmap_urb_for_dma,
2602 #endif
2603 
2604 	.hub_status_data	= musb_hub_status_data,
2605 	.hub_control		= musb_hub_control,
2606 	.bus_suspend		= musb_bus_suspend,
2607 	.bus_resume		= musb_bus_resume,
2608 	/* .start_port_reset	= NULL, */
2609 	/* .hub_irq_enable	= NULL, */
2610 };
2611 
2612 int musb_host_alloc(struct musb *musb)
2613 {
2614 	struct device	*dev = musb->controller;
2615 
2616 	/* usbcore sets dev->driver_data to hcd, and sometimes uses that... */
2617 	musb->hcd = usb_create_hcd(&musb_hc_driver, dev, dev_name(dev));
2618 	if (!musb->hcd)
2619 		return -EINVAL;
2620 
2621 	*musb->hcd->hcd_priv = (unsigned long) musb;
2622 	musb->hcd->self.uses_pio_for_control = 1;
2623 	musb->hcd->uses_new_polling = 1;
2624 	musb->hcd->has_tt = 1;
2625 
2626 	return 0;
2627 }
2628 
2629 void musb_host_cleanup(struct musb *musb)
2630 {
2631 	if (musb->port_mode == MUSB_PORT_MODE_GADGET)
2632 		return;
2633 	usb_remove_hcd(musb->hcd);
2634 	musb->hcd = NULL;
2635 }
2636 
2637 void musb_host_free(struct musb *musb)
2638 {
2639 	usb_put_hcd(musb->hcd);
2640 }
2641 
2642 int musb_host_setup(struct musb *musb, int power_budget)
2643 {
2644 	int ret;
2645 	struct usb_hcd *hcd = musb->hcd;
2646 
2647 	MUSB_HST_MODE(musb);
2648 	musb->xceiv->otg->default_a = 1;
2649 	musb->xceiv->state = OTG_STATE_A_IDLE;
2650 
2651 	otg_set_host(musb->xceiv->otg, &hcd->self);
2652 	hcd->self.otg_port = 1;
2653 	musb->xceiv->otg->host = &hcd->self;
2654 	hcd->power_budget = 2 * (power_budget ? : 250);
2655 
2656 	ret = usb_add_hcd(hcd, 0, 0);
2657 	if (ret < 0)
2658 		return ret;
2659 
2660 	return 0;
2661 }
2662 
2663 void musb_host_resume_root_hub(struct musb *musb)
2664 {
2665 	usb_hcd_resume_root_hub(musb->hcd);
2666 }
2667 
2668 void musb_host_poke_root_hub(struct musb *musb)
2669 {
2670 	MUSB_HST_MODE(musb);
2671 	if (musb->hcd->status_urb)
2672 		usb_hcd_poll_rh_status(musb->hcd);
2673 	else
2674 		usb_hcd_resume_root_hub(musb->hcd);
2675 }
2676