xref: /linux/drivers/usb/musb/musb_host.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
1 /*
2  * MUSB OTG driver host support
3  *
4  * Copyright 2005 Mentor Graphics Corporation
5  * Copyright (C) 2005-2006 by Texas Instruments
6  * Copyright (C) 2006-2007 Nokia Corporation
7  * Copyright (C) 2008-2009 MontaVista Software, Inc. <source@mvista.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * version 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
21  * 02110-1301 USA
22  *
23  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
24  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
26  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
30  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  */
35 
36 #include <linux/module.h>
37 #include <linux/kernel.h>
38 #include <linux/delay.h>
39 #include <linux/sched.h>
40 #include <linux/slab.h>
41 #include <linux/errno.h>
42 #include <linux/init.h>
43 #include <linux/list.h>
44 #include <linux/dma-mapping.h>
45 
46 #include "musb_core.h"
47 #include "musb_host.h"
48 
49 
50 /* MUSB HOST status 22-mar-2006
51  *
52  * - There's still lots of partial code duplication for fault paths, so
53  *   they aren't handled as consistently as they need to be.
54  *
55  * - PIO mostly behaved when last tested.
56  *     + including ep0, with all usbtest cases 9, 10
57  *     + usbtest 14 (ep0out) doesn't seem to run at all
58  *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
59  *       configurations, but otherwise double buffering passes basic tests.
60  *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
61  *
62  * - DMA (CPPI) ... partially behaves, not currently recommended
63  *     + about 1/15 the speed of typical EHCI implementations (PCI)
64  *     + RX, all too often reqpkt seems to misbehave after tx
65  *     + TX, no known issues (other than evident silicon issue)
66  *
67  * - DMA (Mentor/OMAP) ...has at least toggle update problems
68  *
69  * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
70  *   starvation ... nothing yet for TX, interrupt, or bulk.
71  *
72  * - Not tested with HNP, but some SRP paths seem to behave.
73  *
74  * NOTE 24-August-2006:
75  *
76  * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
77  *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
78  *   mostly works, except that with "usbnet" it's easy to trigger cases
79  *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
80  *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
81  *   although ARP RX wins.  (That test was done with a full speed link.)
82  */
83 
84 
85 /*
86  * NOTE on endpoint usage:
87  *
88  * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
89  * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
90  * (Yes, bulk _could_ use more of the endpoints than that, and would even
91  * benefit from it.)
92  *
93  * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
94  * So far that scheduling is both dumb and optimistic:  the endpoint will be
95  * "claimed" until its software queue is no longer refilled.  No multiplexing
96  * of transfers between endpoints, or anything clever.
97  */
98 
99 
100 static void musb_ep_program(struct musb *musb, u8 epnum,
101 			struct urb *urb, int is_out,
102 			u8 *buf, u32 offset, u32 len);
103 
104 /*
105  * Clear TX fifo. Needed to avoid BABBLE errors.
106  */
107 static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
108 {
109 	struct musb	*musb = ep->musb;
110 	void __iomem	*epio = ep->regs;
111 	u16		csr;
112 	u16		lastcsr = 0;
113 	int		retries = 1000;
114 
115 	csr = musb_readw(epio, MUSB_TXCSR);
116 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
117 		if (csr != lastcsr)
118 			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
119 		lastcsr = csr;
120 		csr |= MUSB_TXCSR_FLUSHFIFO;
121 		musb_writew(epio, MUSB_TXCSR, csr);
122 		csr = musb_readw(epio, MUSB_TXCSR);
123 		if (WARN(retries-- < 1,
124 				"Could not flush host TX%d fifo: csr: %04x\n",
125 				ep->epnum, csr))
126 			return;
127 		mdelay(1);
128 	}
129 }
130 
131 static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
132 {
133 	void __iomem	*epio = ep->regs;
134 	u16		csr;
135 	int		retries = 5;
136 
137 	/* scrub any data left in the fifo */
138 	do {
139 		csr = musb_readw(epio, MUSB_TXCSR);
140 		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
141 			break;
142 		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
143 		csr = musb_readw(epio, MUSB_TXCSR);
144 		udelay(10);
145 	} while (--retries);
146 
147 	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
148 			ep->epnum, csr);
149 
150 	/* and reset for the next transfer */
151 	musb_writew(epio, MUSB_TXCSR, 0);
152 }
153 
154 /*
155  * Start transmit. Caller is responsible for locking shared resources.
156  * musb must be locked.
157  */
158 static inline void musb_h_tx_start(struct musb_hw_ep *ep)
159 {
160 	u16	txcsr;
161 
162 	/* NOTE: no locks here; caller should lock and select EP */
163 	if (ep->epnum) {
164 		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
165 		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
166 		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
167 	} else {
168 		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
169 		musb_writew(ep->regs, MUSB_CSR0, txcsr);
170 	}
171 
172 }
173 
174 static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
175 {
176 	u16	txcsr;
177 
178 	/* NOTE: no locks here; caller should lock and select EP */
179 	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
180 	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
181 	if (is_cppi_enabled())
182 		txcsr |= MUSB_TXCSR_DMAMODE;
183 	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
184 }
185 
186 static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
187 {
188 	if (is_in != 0 || ep->is_shared_fifo)
189 		ep->in_qh  = qh;
190 	if (is_in == 0 || ep->is_shared_fifo)
191 		ep->out_qh = qh;
192 }
193 
194 static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
195 {
196 	return is_in ? ep->in_qh : ep->out_qh;
197 }
198 
199 /*
200  * Start the URB at the front of an endpoint's queue
201  * end must be claimed from the caller.
202  *
203  * Context: controller locked, irqs blocked
204  */
205 static void
206 musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
207 {
208 	u16			frame;
209 	u32			len;
210 	void __iomem		*mbase =  musb->mregs;
211 	struct urb		*urb = next_urb(qh);
212 	void			*buf = urb->transfer_buffer;
213 	u32			offset = 0;
214 	struct musb_hw_ep	*hw_ep = qh->hw_ep;
215 	unsigned		pipe = urb->pipe;
216 	u8			address = usb_pipedevice(pipe);
217 	int			epnum = hw_ep->epnum;
218 
219 	/* initialize software qh state */
220 	qh->offset = 0;
221 	qh->segsize = 0;
222 
223 	/* gather right source of data */
224 	switch (qh->type) {
225 	case USB_ENDPOINT_XFER_CONTROL:
226 		/* control transfers always start with SETUP */
227 		is_in = 0;
228 		musb->ep0_stage = MUSB_EP0_START;
229 		buf = urb->setup_packet;
230 		len = 8;
231 		break;
232 	case USB_ENDPOINT_XFER_ISOC:
233 		qh->iso_idx = 0;
234 		qh->frame = 0;
235 		offset = urb->iso_frame_desc[0].offset;
236 		len = urb->iso_frame_desc[0].length;
237 		break;
238 	default:		/* bulk, interrupt */
239 		/* actual_length may be nonzero on retry paths */
240 		buf = urb->transfer_buffer + urb->actual_length;
241 		len = urb->transfer_buffer_length - urb->actual_length;
242 	}
243 
244 	dev_dbg(musb->controller, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
245 			qh, urb, address, qh->epnum,
246 			is_in ? "in" : "out",
247 			({char *s; switch (qh->type) {
248 			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
249 			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
250 			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
251 			default:			s = "-intr"; break;
252 			}; s; }),
253 			epnum, buf + offset, len);
254 
255 	/* Configure endpoint */
256 	musb_ep_set_qh(hw_ep, is_in, qh);
257 	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
258 
259 	/* transmit may have more work: start it when it is time */
260 	if (is_in)
261 		return;
262 
263 	/* determine if the time is right for a periodic transfer */
264 	switch (qh->type) {
265 	case USB_ENDPOINT_XFER_ISOC:
266 	case USB_ENDPOINT_XFER_INT:
267 		dev_dbg(musb->controller, "check whether there's still time for periodic Tx\n");
268 		frame = musb_readw(mbase, MUSB_FRAME);
269 		/* FIXME this doesn't implement that scheduling policy ...
270 		 * or handle framecounter wrapping
271 		 */
272 		if ((urb->transfer_flags & URB_ISO_ASAP)
273 				|| (frame >= urb->start_frame)) {
274 			/* REVISIT the SOF irq handler shouldn't duplicate
275 			 * this code; and we don't init urb->start_frame...
276 			 */
277 			qh->frame = 0;
278 			goto start;
279 		} else {
280 			qh->frame = urb->start_frame;
281 			/* enable SOF interrupt so we can count down */
282 			dev_dbg(musb->controller, "SOF for %d\n", epnum);
283 #if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
284 			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
285 #endif
286 		}
287 		break;
288 	default:
289 start:
290 		dev_dbg(musb->controller, "Start TX%d %s\n", epnum,
291 			hw_ep->tx_channel ? "dma" : "pio");
292 
293 		if (!hw_ep->tx_channel)
294 			musb_h_tx_start(hw_ep);
295 		else if (is_cppi_enabled() || tusb_dma_omap())
296 			musb_h_tx_dma_start(hw_ep);
297 	}
298 }
299 
300 /* Context: caller owns controller lock, IRQs are blocked */
301 static void musb_giveback(struct musb *musb, struct urb *urb, int status)
302 __releases(musb->lock)
303 __acquires(musb->lock)
304 {
305 	dev_dbg(musb->controller,
306 			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
307 			urb, urb->complete, status,
308 			usb_pipedevice(urb->pipe),
309 			usb_pipeendpoint(urb->pipe),
310 			usb_pipein(urb->pipe) ? "in" : "out",
311 			urb->actual_length, urb->transfer_buffer_length
312 			);
313 
314 	usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
315 	spin_unlock(&musb->lock);
316 	usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
317 	spin_lock(&musb->lock);
318 }
319 
320 /* For bulk/interrupt endpoints only */
321 static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
322 				    struct urb *urb)
323 {
324 	void __iomem		*epio = qh->hw_ep->regs;
325 	u16			csr;
326 
327 	/*
328 	 * FIXME: the current Mentor DMA code seems to have
329 	 * problems getting toggle correct.
330 	 */
331 
332 	if (is_in)
333 		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
334 	else
335 		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
336 
337 	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
338 }
339 
340 /*
341  * Advance this hardware endpoint's queue, completing the specified URB and
342  * advancing to either the next URB queued to that qh, or else invalidating
343  * that qh and advancing to the next qh scheduled after the current one.
344  *
345  * Context: caller owns controller lock, IRQs are blocked
346  */
347 static void musb_advance_schedule(struct musb *musb, struct urb *urb,
348 				  struct musb_hw_ep *hw_ep, int is_in)
349 {
350 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
351 	struct musb_hw_ep	*ep = qh->hw_ep;
352 	int			ready = qh->is_ready;
353 	int			status;
354 
355 	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
356 
357 	/* save toggle eagerly, for paranoia */
358 	switch (qh->type) {
359 	case USB_ENDPOINT_XFER_BULK:
360 	case USB_ENDPOINT_XFER_INT:
361 		musb_save_toggle(qh, is_in, urb);
362 		break;
363 	case USB_ENDPOINT_XFER_ISOC:
364 		if (status == 0 && urb->error_count)
365 			status = -EXDEV;
366 		break;
367 	}
368 
369 	qh->is_ready = 0;
370 	musb_giveback(musb, urb, status);
371 	qh->is_ready = ready;
372 
373 	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
374 	 * invalidate qh as soon as list_empty(&hep->urb_list)
375 	 */
376 	if (list_empty(&qh->hep->urb_list)) {
377 		struct list_head	*head;
378 		struct dma_controller	*dma = musb->dma_controller;
379 
380 		if (is_in) {
381 			ep->rx_reinit = 1;
382 			if (ep->rx_channel) {
383 				dma->channel_release(ep->rx_channel);
384 				ep->rx_channel = NULL;
385 			}
386 		} else {
387 			ep->tx_reinit = 1;
388 			if (ep->tx_channel) {
389 				dma->channel_release(ep->tx_channel);
390 				ep->tx_channel = NULL;
391 			}
392 		}
393 
394 		/* Clobber old pointers to this qh */
395 		musb_ep_set_qh(ep, is_in, NULL);
396 		qh->hep->hcpriv = NULL;
397 
398 		switch (qh->type) {
399 
400 		case USB_ENDPOINT_XFER_CONTROL:
401 		case USB_ENDPOINT_XFER_BULK:
402 			/* fifo policy for these lists, except that NAKing
403 			 * should rotate a qh to the end (for fairness).
404 			 */
405 			if (qh->mux == 1) {
406 				head = qh->ring.prev;
407 				list_del(&qh->ring);
408 				kfree(qh);
409 				qh = first_qh(head);
410 				break;
411 			}
412 
413 		case USB_ENDPOINT_XFER_ISOC:
414 		case USB_ENDPOINT_XFER_INT:
415 			/* this is where periodic bandwidth should be
416 			 * de-allocated if it's tracked and allocated;
417 			 * and where we'd update the schedule tree...
418 			 */
419 			kfree(qh);
420 			qh = NULL;
421 			break;
422 		}
423 	}
424 
425 	if (qh != NULL && qh->is_ready) {
426 		dev_dbg(musb->controller, "... next ep%d %cX urb %p\n",
427 		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
428 		musb_start_urb(musb, is_in, qh);
429 	}
430 }
431 
432 static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
433 {
434 	/* we don't want fifo to fill itself again;
435 	 * ignore dma (various models),
436 	 * leave toggle alone (may not have been saved yet)
437 	 */
438 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
439 	csr &= ~(MUSB_RXCSR_H_REQPKT
440 		| MUSB_RXCSR_H_AUTOREQ
441 		| MUSB_RXCSR_AUTOCLEAR);
442 
443 	/* write 2x to allow double buffering */
444 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
445 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
446 
447 	/* flush writebuffer */
448 	return musb_readw(hw_ep->regs, MUSB_RXCSR);
449 }
450 
451 /*
452  * PIO RX for a packet (or part of it).
453  */
454 static bool
455 musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
456 {
457 	u16			rx_count;
458 	u8			*buf;
459 	u16			csr;
460 	bool			done = false;
461 	u32			length;
462 	int			do_flush = 0;
463 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
464 	void __iomem		*epio = hw_ep->regs;
465 	struct musb_qh		*qh = hw_ep->in_qh;
466 	int			pipe = urb->pipe;
467 	void			*buffer = urb->transfer_buffer;
468 
469 	/* musb_ep_select(mbase, epnum); */
470 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
471 	dev_dbg(musb->controller, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
472 			urb->transfer_buffer, qh->offset,
473 			urb->transfer_buffer_length);
474 
475 	/* unload FIFO */
476 	if (usb_pipeisoc(pipe)) {
477 		int					status = 0;
478 		struct usb_iso_packet_descriptor	*d;
479 
480 		if (iso_err) {
481 			status = -EILSEQ;
482 			urb->error_count++;
483 		}
484 
485 		d = urb->iso_frame_desc + qh->iso_idx;
486 		buf = buffer + d->offset;
487 		length = d->length;
488 		if (rx_count > length) {
489 			if (status == 0) {
490 				status = -EOVERFLOW;
491 				urb->error_count++;
492 			}
493 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
494 			do_flush = 1;
495 		} else
496 			length = rx_count;
497 		urb->actual_length += length;
498 		d->actual_length = length;
499 
500 		d->status = status;
501 
502 		/* see if we are done */
503 		done = (++qh->iso_idx >= urb->number_of_packets);
504 	} else {
505 		/* non-isoch */
506 		buf = buffer + qh->offset;
507 		length = urb->transfer_buffer_length - qh->offset;
508 		if (rx_count > length) {
509 			if (urb->status == -EINPROGRESS)
510 				urb->status = -EOVERFLOW;
511 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
512 			do_flush = 1;
513 		} else
514 			length = rx_count;
515 		urb->actual_length += length;
516 		qh->offset += length;
517 
518 		/* see if we are done */
519 		done = (urb->actual_length == urb->transfer_buffer_length)
520 			|| (rx_count < qh->maxpacket)
521 			|| (urb->status != -EINPROGRESS);
522 		if (done
523 				&& (urb->status == -EINPROGRESS)
524 				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
525 				&& (urb->actual_length
526 					< urb->transfer_buffer_length))
527 			urb->status = -EREMOTEIO;
528 	}
529 
530 	musb_read_fifo(hw_ep, length, buf);
531 
532 	csr = musb_readw(epio, MUSB_RXCSR);
533 	csr |= MUSB_RXCSR_H_WZC_BITS;
534 	if (unlikely(do_flush))
535 		musb_h_flush_rxfifo(hw_ep, csr);
536 	else {
537 		/* REVISIT this assumes AUTOCLEAR is never set */
538 		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
539 		if (!done)
540 			csr |= MUSB_RXCSR_H_REQPKT;
541 		musb_writew(epio, MUSB_RXCSR, csr);
542 	}
543 
544 	return done;
545 }
546 
547 /* we don't always need to reinit a given side of an endpoint...
548  * when we do, use tx/rx reinit routine and then construct a new CSR
549  * to address data toggle, NYET, and DMA or PIO.
550  *
551  * it's possible that driver bugs (especially for DMA) or aborting a
552  * transfer might have left the endpoint busier than it should be.
553  * the busy/not-empty tests are basically paranoia.
554  */
555 static void
556 musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
557 {
558 	u16	csr;
559 
560 	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
561 	 * That always uses tx_reinit since ep0 repurposes TX register
562 	 * offsets; the initial SETUP packet is also a kind of OUT.
563 	 */
564 
565 	/* if programmed for Tx, put it in RX mode */
566 	if (ep->is_shared_fifo) {
567 		csr = musb_readw(ep->regs, MUSB_TXCSR);
568 		if (csr & MUSB_TXCSR_MODE) {
569 			musb_h_tx_flush_fifo(ep);
570 			csr = musb_readw(ep->regs, MUSB_TXCSR);
571 			musb_writew(ep->regs, MUSB_TXCSR,
572 				    csr | MUSB_TXCSR_FRCDATATOG);
573 		}
574 
575 		/*
576 		 * Clear the MODE bit (and everything else) to enable Rx.
577 		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
578 		 */
579 		if (csr & MUSB_TXCSR_DMAMODE)
580 			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
581 		musb_writew(ep->regs, MUSB_TXCSR, 0);
582 
583 	/* scrub all previous state, clearing toggle */
584 	} else {
585 		csr = musb_readw(ep->regs, MUSB_RXCSR);
586 		if (csr & MUSB_RXCSR_RXPKTRDY)
587 			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
588 				musb_readw(ep->regs, MUSB_RXCOUNT));
589 
590 		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
591 	}
592 
593 	/* target addr and (for multipoint) hub addr/port */
594 	if (musb->is_multipoint) {
595 		musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
596 		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
597 		musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
598 
599 	} else
600 		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
601 
602 	/* protocol/endpoint, interval/NAKlimit, i/o size */
603 	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
604 	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
605 	/* NOTE: bulk combining rewrites high bits of maxpacket */
606 	/* Set RXMAXP with the FIFO size of the endpoint
607 	 * to disable double buffer mode.
608 	 */
609 	if (musb->double_buffer_not_ok)
610 		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
611 	else
612 		musb_writew(ep->regs, MUSB_RXMAXP,
613 				qh->maxpacket | ((qh->hb_mult - 1) << 11));
614 
615 	ep->rx_reinit = 0;
616 }
617 
618 static bool musb_tx_dma_program(struct dma_controller *dma,
619 		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
620 		struct urb *urb, u32 offset, u32 length)
621 {
622 	struct dma_channel	*channel = hw_ep->tx_channel;
623 	void __iomem		*epio = hw_ep->regs;
624 	u16			pkt_size = qh->maxpacket;
625 	u16			csr;
626 	u8			mode;
627 
628 #ifdef	CONFIG_USB_INVENTRA_DMA
629 	if (length > channel->max_len)
630 		length = channel->max_len;
631 
632 	csr = musb_readw(epio, MUSB_TXCSR);
633 	if (length > pkt_size) {
634 		mode = 1;
635 		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
636 		/* autoset shouldn't be set in high bandwidth */
637 		if (qh->hb_mult == 1)
638 			csr |= MUSB_TXCSR_AUTOSET;
639 	} else {
640 		mode = 0;
641 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
642 		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
643 	}
644 	channel->desired_mode = mode;
645 	musb_writew(epio, MUSB_TXCSR, csr);
646 #else
647 	if (!is_cppi_enabled() && !tusb_dma_omap())
648 		return false;
649 
650 	channel->actual_len = 0;
651 
652 	/*
653 	 * TX uses "RNDIS" mode automatically but needs help
654 	 * to identify the zero-length-final-packet case.
655 	 */
656 	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
657 #endif
658 
659 	qh->segsize = length;
660 
661 	/*
662 	 * Ensure the data reaches to main memory before starting
663 	 * DMA transfer
664 	 */
665 	wmb();
666 
667 	if (!dma->channel_program(channel, pkt_size, mode,
668 			urb->transfer_dma + offset, length)) {
669 		dma->channel_release(channel);
670 		hw_ep->tx_channel = NULL;
671 
672 		csr = musb_readw(epio, MUSB_TXCSR);
673 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
674 		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
675 		return false;
676 	}
677 	return true;
678 }
679 
680 /*
681  * Program an HDRC endpoint as per the given URB
682  * Context: irqs blocked, controller lock held
683  */
684 static void musb_ep_program(struct musb *musb, u8 epnum,
685 			struct urb *urb, int is_out,
686 			u8 *buf, u32 offset, u32 len)
687 {
688 	struct dma_controller	*dma_controller;
689 	struct dma_channel	*dma_channel;
690 	u8			dma_ok;
691 	void __iomem		*mbase = musb->mregs;
692 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
693 	void __iomem		*epio = hw_ep->regs;
694 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
695 	u16			packet_sz = qh->maxpacket;
696 	u8			use_dma = 1;
697 	u16			csr;
698 
699 	dev_dbg(musb->controller, "%s hw%d urb %p spd%d dev%d ep%d%s "
700 				"h_addr%02x h_port%02x bytes %d\n",
701 			is_out ? "-->" : "<--",
702 			epnum, urb, urb->dev->speed,
703 			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
704 			qh->h_addr_reg, qh->h_port_reg,
705 			len);
706 
707 	musb_ep_select(mbase, epnum);
708 
709 	if (is_out && !len) {
710 		use_dma = 0;
711 		csr = musb_readw(epio, MUSB_TXCSR);
712 		csr &= ~MUSB_TXCSR_DMAENAB;
713 		musb_writew(epio, MUSB_TXCSR, csr);
714 		hw_ep->tx_channel = NULL;
715 	}
716 
717 	/* candidate for DMA? */
718 	dma_controller = musb->dma_controller;
719 	if (use_dma && is_dma_capable() && epnum && dma_controller) {
720 		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
721 		if (!dma_channel) {
722 			dma_channel = dma_controller->channel_alloc(
723 					dma_controller, hw_ep, is_out);
724 			if (is_out)
725 				hw_ep->tx_channel = dma_channel;
726 			else
727 				hw_ep->rx_channel = dma_channel;
728 		}
729 	} else
730 		dma_channel = NULL;
731 
732 	/* make sure we clear DMAEnab, autoSet bits from previous run */
733 
734 	/* OUT/transmit/EP0 or IN/receive? */
735 	if (is_out) {
736 		u16	csr;
737 		u16	int_txe;
738 		u16	load_count;
739 
740 		csr = musb_readw(epio, MUSB_TXCSR);
741 
742 		/* disable interrupt in case we flush */
743 		int_txe = musb->intrtxe;
744 		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
745 
746 		/* general endpoint setup */
747 		if (epnum) {
748 			/* flush all old state, set default */
749 			musb_h_tx_flush_fifo(hw_ep);
750 
751 			/*
752 			 * We must not clear the DMAMODE bit before or in
753 			 * the same cycle with the DMAENAB bit, so we clear
754 			 * the latter first...
755 			 */
756 			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
757 					| MUSB_TXCSR_AUTOSET
758 					| MUSB_TXCSR_DMAENAB
759 					| MUSB_TXCSR_FRCDATATOG
760 					| MUSB_TXCSR_H_RXSTALL
761 					| MUSB_TXCSR_H_ERROR
762 					| MUSB_TXCSR_TXPKTRDY
763 					);
764 			csr |= MUSB_TXCSR_MODE;
765 
766 			if (usb_gettoggle(urb->dev, qh->epnum, 1))
767 				csr |= MUSB_TXCSR_H_WR_DATATOGGLE
768 					| MUSB_TXCSR_H_DATATOGGLE;
769 			else
770 				csr |= MUSB_TXCSR_CLRDATATOG;
771 
772 			musb_writew(epio, MUSB_TXCSR, csr);
773 			/* REVISIT may need to clear FLUSHFIFO ... */
774 			csr &= ~MUSB_TXCSR_DMAMODE;
775 			musb_writew(epio, MUSB_TXCSR, csr);
776 			csr = musb_readw(epio, MUSB_TXCSR);
777 		} else {
778 			/* endpoint 0: just flush */
779 			musb_h_ep0_flush_fifo(hw_ep);
780 		}
781 
782 		/* target addr and (for multipoint) hub addr/port */
783 		if (musb->is_multipoint) {
784 			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
785 			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
786 			musb_write_txhubport(mbase, epnum, qh->h_port_reg);
787 /* FIXME if !epnum, do the same for RX ... */
788 		} else
789 			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
790 
791 		/* protocol/endpoint/interval/NAKlimit */
792 		if (epnum) {
793 			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
794 			if (musb->double_buffer_not_ok)
795 				musb_writew(epio, MUSB_TXMAXP,
796 						hw_ep->max_packet_sz_tx);
797 			else if (can_bulk_split(musb, qh->type))
798 				musb_writew(epio, MUSB_TXMAXP, packet_sz
799 					| ((hw_ep->max_packet_sz_tx /
800 						packet_sz) - 1) << 11);
801 			else
802 				musb_writew(epio, MUSB_TXMAXP,
803 						qh->maxpacket |
804 						((qh->hb_mult - 1) << 11));
805 			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
806 		} else {
807 			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
808 			if (musb->is_multipoint)
809 				musb_writeb(epio, MUSB_TYPE0,
810 						qh->type_reg);
811 		}
812 
813 		if (can_bulk_split(musb, qh->type))
814 			load_count = min((u32) hw_ep->max_packet_sz_tx,
815 						len);
816 		else
817 			load_count = min((u32) packet_sz, len);
818 
819 		if (dma_channel && musb_tx_dma_program(dma_controller,
820 					hw_ep, qh, urb, offset, len))
821 			load_count = 0;
822 
823 		if (load_count) {
824 			/* PIO to load FIFO */
825 			qh->segsize = load_count;
826 			if (!buf) {
827 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
828 						SG_MITER_ATOMIC
829 						| SG_MITER_FROM_SG);
830 				if (!sg_miter_next(&qh->sg_miter)) {
831 					dev_err(musb->controller,
832 							"error: sg"
833 							"list empty\n");
834 					sg_miter_stop(&qh->sg_miter);
835 					goto finish;
836 				}
837 				buf = qh->sg_miter.addr + urb->sg->offset +
838 					urb->actual_length;
839 				load_count = min_t(u32, load_count,
840 						qh->sg_miter.length);
841 				musb_write_fifo(hw_ep, load_count, buf);
842 				qh->sg_miter.consumed = load_count;
843 				sg_miter_stop(&qh->sg_miter);
844 			} else
845 				musb_write_fifo(hw_ep, load_count, buf);
846 		}
847 finish:
848 		/* re-enable interrupt */
849 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
850 
851 	/* IN/receive */
852 	} else {
853 		u16	csr;
854 
855 		if (hw_ep->rx_reinit) {
856 			musb_rx_reinit(musb, qh, hw_ep);
857 
858 			/* init new state: toggle and NYET, maybe DMA later */
859 			if (usb_gettoggle(urb->dev, qh->epnum, 0))
860 				csr = MUSB_RXCSR_H_WR_DATATOGGLE
861 					| MUSB_RXCSR_H_DATATOGGLE;
862 			else
863 				csr = 0;
864 			if (qh->type == USB_ENDPOINT_XFER_INT)
865 				csr |= MUSB_RXCSR_DISNYET;
866 
867 		} else {
868 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
869 
870 			if (csr & (MUSB_RXCSR_RXPKTRDY
871 					| MUSB_RXCSR_DMAENAB
872 					| MUSB_RXCSR_H_REQPKT))
873 				ERR("broken !rx_reinit, ep%d csr %04x\n",
874 						hw_ep->epnum, csr);
875 
876 			/* scrub any stale state, leaving toggle alone */
877 			csr &= MUSB_RXCSR_DISNYET;
878 		}
879 
880 		/* kick things off */
881 
882 		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
883 			/* Candidate for DMA */
884 			dma_channel->actual_len = 0L;
885 			qh->segsize = len;
886 
887 			/* AUTOREQ is in a DMA register */
888 			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
889 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
890 
891 			/*
892 			 * Unless caller treats short RX transfers as
893 			 * errors, we dare not queue multiple transfers.
894 			 */
895 			dma_ok = dma_controller->channel_program(dma_channel,
896 					packet_sz, !(urb->transfer_flags &
897 						     URB_SHORT_NOT_OK),
898 					urb->transfer_dma + offset,
899 					qh->segsize);
900 			if (!dma_ok) {
901 				dma_controller->channel_release(dma_channel);
902 				hw_ep->rx_channel = dma_channel = NULL;
903 			} else
904 				csr |= MUSB_RXCSR_DMAENAB;
905 		}
906 
907 		csr |= MUSB_RXCSR_H_REQPKT;
908 		dev_dbg(musb->controller, "RXCSR%d := %04x\n", epnum, csr);
909 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
910 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
911 	}
912 }
913 
914 /* Schedule next QH from musb->in_bulk/out_bulk and move the current qh to
915  * the end; avoids starvation for other endpoints.
916  */
917 static void musb_bulk_nak_timeout(struct musb *musb, struct musb_hw_ep *ep,
918 	int is_in)
919 {
920 	struct dma_channel	*dma;
921 	struct urb		*urb;
922 	void __iomem		*mbase = musb->mregs;
923 	void __iomem		*epio = ep->regs;
924 	struct musb_qh		*cur_qh, *next_qh;
925 	u16			rx_csr, tx_csr;
926 
927 	musb_ep_select(mbase, ep->epnum);
928 	if (is_in) {
929 		dma = is_dma_capable() ? ep->rx_channel : NULL;
930 
931 		/* clear nak timeout bit */
932 		rx_csr = musb_readw(epio, MUSB_RXCSR);
933 		rx_csr |= MUSB_RXCSR_H_WZC_BITS;
934 		rx_csr &= ~MUSB_RXCSR_DATAERROR;
935 		musb_writew(epio, MUSB_RXCSR, rx_csr);
936 
937 		cur_qh = first_qh(&musb->in_bulk);
938 	} else {
939 		dma = is_dma_capable() ? ep->tx_channel : NULL;
940 
941 		/* clear nak timeout bit */
942 		tx_csr = musb_readw(epio, MUSB_TXCSR);
943 		tx_csr |= MUSB_TXCSR_H_WZC_BITS;
944 		tx_csr &= ~MUSB_TXCSR_H_NAKTIMEOUT;
945 		musb_writew(epio, MUSB_TXCSR, tx_csr);
946 
947 		cur_qh = first_qh(&musb->out_bulk);
948 	}
949 	if (cur_qh) {
950 		urb = next_urb(cur_qh);
951 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
952 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
953 			musb->dma_controller->channel_abort(dma);
954 			urb->actual_length += dma->actual_len;
955 			dma->actual_len = 0L;
956 		}
957 		musb_save_toggle(cur_qh, is_in, urb);
958 
959 		if (is_in) {
960 			/* move cur_qh to end of queue */
961 			list_move_tail(&cur_qh->ring, &musb->in_bulk);
962 
963 			/* get the next qh from musb->in_bulk */
964 			next_qh = first_qh(&musb->in_bulk);
965 
966 			/* set rx_reinit and schedule the next qh */
967 			ep->rx_reinit = 1;
968 		} else {
969 			/* move cur_qh to end of queue */
970 			list_move_tail(&cur_qh->ring, &musb->out_bulk);
971 
972 			/* get the next qh from musb->out_bulk */
973 			next_qh = first_qh(&musb->out_bulk);
974 
975 			/* set tx_reinit and schedule the next qh */
976 			ep->tx_reinit = 1;
977 		}
978 		musb_start_urb(musb, is_in, next_qh);
979 	}
980 }
981 
982 /*
983  * Service the default endpoint (ep0) as host.
984  * Return true until it's time to start the status stage.
985  */
986 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
987 {
988 	bool			 more = false;
989 	u8			*fifo_dest = NULL;
990 	u16			fifo_count = 0;
991 	struct musb_hw_ep	*hw_ep = musb->control_ep;
992 	struct musb_qh		*qh = hw_ep->in_qh;
993 	struct usb_ctrlrequest	*request;
994 
995 	switch (musb->ep0_stage) {
996 	case MUSB_EP0_IN:
997 		fifo_dest = urb->transfer_buffer + urb->actual_length;
998 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
999 				   urb->actual_length);
1000 		if (fifo_count < len)
1001 			urb->status = -EOVERFLOW;
1002 
1003 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
1004 
1005 		urb->actual_length += fifo_count;
1006 		if (len < qh->maxpacket) {
1007 			/* always terminate on short read; it's
1008 			 * rarely reported as an error.
1009 			 */
1010 		} else if (urb->actual_length <
1011 				urb->transfer_buffer_length)
1012 			more = true;
1013 		break;
1014 	case MUSB_EP0_START:
1015 		request = (struct usb_ctrlrequest *) urb->setup_packet;
1016 
1017 		if (!request->wLength) {
1018 			dev_dbg(musb->controller, "start no-DATA\n");
1019 			break;
1020 		} else if (request->bRequestType & USB_DIR_IN) {
1021 			dev_dbg(musb->controller, "start IN-DATA\n");
1022 			musb->ep0_stage = MUSB_EP0_IN;
1023 			more = true;
1024 			break;
1025 		} else {
1026 			dev_dbg(musb->controller, "start OUT-DATA\n");
1027 			musb->ep0_stage = MUSB_EP0_OUT;
1028 			more = true;
1029 		}
1030 		/* FALLTHROUGH */
1031 	case MUSB_EP0_OUT:
1032 		fifo_count = min_t(size_t, qh->maxpacket,
1033 				   urb->transfer_buffer_length -
1034 				   urb->actual_length);
1035 		if (fifo_count) {
1036 			fifo_dest = (u8 *) (urb->transfer_buffer
1037 					+ urb->actual_length);
1038 			dev_dbg(musb->controller, "Sending %d byte%s to ep0 fifo %p\n",
1039 					fifo_count,
1040 					(fifo_count == 1) ? "" : "s",
1041 					fifo_dest);
1042 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
1043 
1044 			urb->actual_length += fifo_count;
1045 			more = true;
1046 		}
1047 		break;
1048 	default:
1049 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
1050 		break;
1051 	}
1052 
1053 	return more;
1054 }
1055 
1056 /*
1057  * Handle default endpoint interrupt as host. Only called in IRQ time
1058  * from musb_interrupt().
1059  *
1060  * called with controller irqlocked
1061  */
1062 irqreturn_t musb_h_ep0_irq(struct musb *musb)
1063 {
1064 	struct urb		*urb;
1065 	u16			csr, len;
1066 	int			status = 0;
1067 	void __iomem		*mbase = musb->mregs;
1068 	struct musb_hw_ep	*hw_ep = musb->control_ep;
1069 	void __iomem		*epio = hw_ep->regs;
1070 	struct musb_qh		*qh = hw_ep->in_qh;
1071 	bool			complete = false;
1072 	irqreturn_t		retval = IRQ_NONE;
1073 
1074 	/* ep0 only has one queue, "in" */
1075 	urb = next_urb(qh);
1076 
1077 	musb_ep_select(mbase, 0);
1078 	csr = musb_readw(epio, MUSB_CSR0);
1079 	len = (csr & MUSB_CSR0_RXPKTRDY)
1080 			? musb_readb(epio, MUSB_COUNT0)
1081 			: 0;
1082 
1083 	dev_dbg(musb->controller, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
1084 		csr, qh, len, urb, musb->ep0_stage);
1085 
1086 	/* if we just did status stage, we are done */
1087 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
1088 		retval = IRQ_HANDLED;
1089 		complete = true;
1090 	}
1091 
1092 	/* prepare status */
1093 	if (csr & MUSB_CSR0_H_RXSTALL) {
1094 		dev_dbg(musb->controller, "STALLING ENDPOINT\n");
1095 		status = -EPIPE;
1096 
1097 	} else if (csr & MUSB_CSR0_H_ERROR) {
1098 		dev_dbg(musb->controller, "no response, csr0 %04x\n", csr);
1099 		status = -EPROTO;
1100 
1101 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1102 		dev_dbg(musb->controller, "control NAK timeout\n");
1103 
1104 		/* NOTE:  this code path would be a good place to PAUSE a
1105 		 * control transfer, if another one is queued, so that
1106 		 * ep0 is more likely to stay busy.  That's already done
1107 		 * for bulk RX transfers.
1108 		 *
1109 		 * if (qh->ring.next != &musb->control), then
1110 		 * we have a candidate... NAKing is *NOT* an error
1111 		 */
1112 		musb_writew(epio, MUSB_CSR0, 0);
1113 		retval = IRQ_HANDLED;
1114 	}
1115 
1116 	if (status) {
1117 		dev_dbg(musb->controller, "aborting\n");
1118 		retval = IRQ_HANDLED;
1119 		if (urb)
1120 			urb->status = status;
1121 		complete = true;
1122 
1123 		/* use the proper sequence to abort the transfer */
1124 		if (csr & MUSB_CSR0_H_REQPKT) {
1125 			csr &= ~MUSB_CSR0_H_REQPKT;
1126 			musb_writew(epio, MUSB_CSR0, csr);
1127 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1128 			musb_writew(epio, MUSB_CSR0, csr);
1129 		} else {
1130 			musb_h_ep0_flush_fifo(hw_ep);
1131 		}
1132 
1133 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1134 
1135 		/* clear it */
1136 		musb_writew(epio, MUSB_CSR0, 0);
1137 	}
1138 
1139 	if (unlikely(!urb)) {
1140 		/* stop endpoint since we have no place for its data, this
1141 		 * SHOULD NEVER HAPPEN! */
1142 		ERR("no URB for end 0\n");
1143 
1144 		musb_h_ep0_flush_fifo(hw_ep);
1145 		goto done;
1146 	}
1147 
1148 	if (!complete) {
1149 		/* call common logic and prepare response */
1150 		if (musb_h_ep0_continue(musb, len, urb)) {
1151 			/* more packets required */
1152 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1153 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1154 		} else {
1155 			/* data transfer complete; perform status phase */
1156 			if (usb_pipeout(urb->pipe)
1157 					|| !urb->transfer_buffer_length)
1158 				csr = MUSB_CSR0_H_STATUSPKT
1159 					| MUSB_CSR0_H_REQPKT;
1160 			else
1161 				csr = MUSB_CSR0_H_STATUSPKT
1162 					| MUSB_CSR0_TXPKTRDY;
1163 
1164 			/* flag status stage */
1165 			musb->ep0_stage = MUSB_EP0_STATUS;
1166 
1167 			dev_dbg(musb->controller, "ep0 STATUS, csr %04x\n", csr);
1168 
1169 		}
1170 		musb_writew(epio, MUSB_CSR0, csr);
1171 		retval = IRQ_HANDLED;
1172 	} else
1173 		musb->ep0_stage = MUSB_EP0_IDLE;
1174 
1175 	/* call completion handler if done */
1176 	if (complete)
1177 		musb_advance_schedule(musb, urb, hw_ep, 1);
1178 done:
1179 	return retval;
1180 }
1181 
1182 
1183 #ifdef CONFIG_USB_INVENTRA_DMA
1184 
1185 /* Host side TX (OUT) using Mentor DMA works as follows:
1186 	submit_urb ->
1187 		- if queue was empty, Program Endpoint
1188 		- ... which starts DMA to fifo in mode 1 or 0
1189 
1190 	DMA Isr (transfer complete) -> TxAvail()
1191 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1192 					only in musb_cleanup_urb)
1193 		- TxPktRdy has to be set in mode 0 or for
1194 			short packets in mode 1.
1195 */
1196 
1197 #endif
1198 
1199 /* Service a Tx-Available or dma completion irq for the endpoint */
1200 void musb_host_tx(struct musb *musb, u8 epnum)
1201 {
1202 	int			pipe;
1203 	bool			done = false;
1204 	u16			tx_csr;
1205 	size_t			length = 0;
1206 	size_t			offset = 0;
1207 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1208 	void __iomem		*epio = hw_ep->regs;
1209 	struct musb_qh		*qh = hw_ep->out_qh;
1210 	struct urb		*urb = next_urb(qh);
1211 	u32			status = 0;
1212 	void __iomem		*mbase = musb->mregs;
1213 	struct dma_channel	*dma;
1214 	bool			transfer_pending = false;
1215 	static bool use_sg;
1216 
1217 	musb_ep_select(mbase, epnum);
1218 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1219 
1220 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1221 	if (!urb) {
1222 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1223 		return;
1224 	}
1225 
1226 	pipe = urb->pipe;
1227 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1228 	dev_dbg(musb->controller, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
1229 			dma ? ", dma" : "");
1230 
1231 	/* check for errors */
1232 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1233 		/* dma was disabled, fifo flushed */
1234 		dev_dbg(musb->controller, "TX end %d stall\n", epnum);
1235 
1236 		/* stall; record URB status */
1237 		status = -EPIPE;
1238 
1239 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1240 		/* (NON-ISO) dma was disabled, fifo flushed */
1241 		dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum);
1242 
1243 		status = -ETIMEDOUT;
1244 
1245 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1246 		if (USB_ENDPOINT_XFER_BULK == qh->type && qh->mux == 1
1247 				&& !list_is_singular(&musb->out_bulk)) {
1248 			dev_dbg(musb->controller,
1249 				"NAK timeout on TX%d ep\n", epnum);
1250 			musb_bulk_nak_timeout(musb, hw_ep, 0);
1251 		} else {
1252 			dev_dbg(musb->controller,
1253 				"TX end=%d device not responding\n", epnum);
1254 			/* NOTE:  this code path would be a good place to PAUSE a
1255 			 * transfer, if there's some other (nonperiodic) tx urb
1256 			 * that could use this fifo.  (dma complicates it...)
1257 			 * That's already done for bulk RX transfers.
1258 			 *
1259 			 * if (bulk && qh->ring.next != &musb->out_bulk), then
1260 			 * we have a candidate... NAKing is *NOT* an error
1261 			 */
1262 			musb_ep_select(mbase, epnum);
1263 			musb_writew(epio, MUSB_TXCSR,
1264 					MUSB_TXCSR_H_WZC_BITS
1265 					| MUSB_TXCSR_TXPKTRDY);
1266 		}
1267 			return;
1268 	}
1269 
1270 done:
1271 	if (status) {
1272 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1273 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1274 			(void) musb->dma_controller->channel_abort(dma);
1275 		}
1276 
1277 		/* do the proper sequence to abort the transfer in the
1278 		 * usb core; the dma engine should already be stopped.
1279 		 */
1280 		musb_h_tx_flush_fifo(hw_ep);
1281 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1282 				| MUSB_TXCSR_DMAENAB
1283 				| MUSB_TXCSR_H_ERROR
1284 				| MUSB_TXCSR_H_RXSTALL
1285 				| MUSB_TXCSR_H_NAKTIMEOUT
1286 				);
1287 
1288 		musb_ep_select(mbase, epnum);
1289 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1290 		/* REVISIT may need to clear FLUSHFIFO ... */
1291 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1292 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1293 
1294 		done = true;
1295 	}
1296 
1297 	/* second cppi case */
1298 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1299 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1300 		return;
1301 	}
1302 
1303 	if (is_dma_capable() && dma && !status) {
1304 		/*
1305 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1306 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1307 		 * we can consider this transfer completed, lest we trash
1308 		 * its last packet when writing the next URB's data.  So we
1309 		 * switch back to mode 0 to get that interrupt; we'll come
1310 		 * back here once it happens.
1311 		 */
1312 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1313 			/*
1314 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1315 			 * clear them in a safe order.  That should be OK
1316 			 * once TXPKTRDY has been set (and I've never seen
1317 			 * it being 0 at this moment -- DMA interrupt latency
1318 			 * is significant) but if it hasn't been then we have
1319 			 * no choice but to stop being polite and ignore the
1320 			 * programmer's guide... :-)
1321 			 *
1322 			 * Note that we must write TXCSR with TXPKTRDY cleared
1323 			 * in order not to re-trigger the packet send (this bit
1324 			 * can't be cleared by CPU), and there's another caveat:
1325 			 * TXPKTRDY may be set shortly and then cleared in the
1326 			 * double-buffered FIFO mode, so we do an extra TXCSR
1327 			 * read for debouncing...
1328 			 */
1329 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1330 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1331 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1332 					    MUSB_TXCSR_TXPKTRDY);
1333 				musb_writew(epio, MUSB_TXCSR,
1334 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1335 			}
1336 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1337 				    MUSB_TXCSR_TXPKTRDY);
1338 			musb_writew(epio, MUSB_TXCSR,
1339 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1340 
1341 			/*
1342 			 * There is no guarantee that we'll get an interrupt
1343 			 * after clearing DMAMODE as we might have done this
1344 			 * too late (after TXPKTRDY was cleared by controller).
1345 			 * Re-read TXCSR as we have spoiled its previous value.
1346 			 */
1347 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1348 		}
1349 
1350 		/*
1351 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1352 		 * In any case, we must check the FIFO status here and bail out
1353 		 * only if the FIFO still has data -- that should prevent the
1354 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1355 		 * FIFO mode too...
1356 		 */
1357 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1358 			dev_dbg(musb->controller, "DMA complete but packet still in FIFO, "
1359 			    "CSR %04x\n", tx_csr);
1360 			return;
1361 		}
1362 	}
1363 
1364 	if (!status || dma || usb_pipeisoc(pipe)) {
1365 		if (dma)
1366 			length = dma->actual_len;
1367 		else
1368 			length = qh->segsize;
1369 		qh->offset += length;
1370 
1371 		if (usb_pipeisoc(pipe)) {
1372 			struct usb_iso_packet_descriptor	*d;
1373 
1374 			d = urb->iso_frame_desc + qh->iso_idx;
1375 			d->actual_length = length;
1376 			d->status = status;
1377 			if (++qh->iso_idx >= urb->number_of_packets) {
1378 				done = true;
1379 			} else {
1380 				d++;
1381 				offset = d->offset;
1382 				length = d->length;
1383 			}
1384 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1385 			done = true;
1386 		} else {
1387 			/* see if we need to send more data, or ZLP */
1388 			if (qh->segsize < qh->maxpacket)
1389 				done = true;
1390 			else if (qh->offset == urb->transfer_buffer_length
1391 					&& !(urb->transfer_flags
1392 						& URB_ZERO_PACKET))
1393 				done = true;
1394 			if (!done) {
1395 				offset = qh->offset;
1396 				length = urb->transfer_buffer_length - offset;
1397 				transfer_pending = true;
1398 			}
1399 		}
1400 	}
1401 
1402 	/* urb->status != -EINPROGRESS means request has been faulted,
1403 	 * so we must abort this transfer after cleanup
1404 	 */
1405 	if (urb->status != -EINPROGRESS) {
1406 		done = true;
1407 		if (status == 0)
1408 			status = urb->status;
1409 	}
1410 
1411 	if (done) {
1412 		/* set status */
1413 		urb->status = status;
1414 		urb->actual_length = qh->offset;
1415 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1416 		return;
1417 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1418 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1419 				offset, length)) {
1420 			if (is_cppi_enabled() || tusb_dma_omap())
1421 				musb_h_tx_dma_start(hw_ep);
1422 			return;
1423 		}
1424 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1425 		dev_dbg(musb->controller, "not complete, but DMA enabled?\n");
1426 		return;
1427 	}
1428 
1429 	/*
1430 	 * PIO: start next packet in this URB.
1431 	 *
1432 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1433 	 * (and presumably, FIFO is not half-full) we should write *two*
1434 	 * packets before updating TXCSR; other docs disagree...
1435 	 */
1436 	if (length > qh->maxpacket)
1437 		length = qh->maxpacket;
1438 	/* Unmap the buffer so that CPU can use it */
1439 	usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1440 
1441 	/*
1442 	 * We need to map sg if the transfer_buffer is
1443 	 * NULL.
1444 	 */
1445 	if (!urb->transfer_buffer)
1446 		use_sg = true;
1447 
1448 	if (use_sg) {
1449 		/* sg_miter_start is already done in musb_ep_program */
1450 		if (!sg_miter_next(&qh->sg_miter)) {
1451 			dev_err(musb->controller, "error: sg list empty\n");
1452 			sg_miter_stop(&qh->sg_miter);
1453 			status = -EINVAL;
1454 			goto done;
1455 		}
1456 		urb->transfer_buffer = qh->sg_miter.addr;
1457 		length = min_t(u32, length, qh->sg_miter.length);
1458 		musb_write_fifo(hw_ep, length, urb->transfer_buffer);
1459 		qh->sg_miter.consumed = length;
1460 		sg_miter_stop(&qh->sg_miter);
1461 	} else {
1462 		musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1463 	}
1464 
1465 	qh->segsize = length;
1466 
1467 	if (use_sg) {
1468 		if (offset + length >= urb->transfer_buffer_length)
1469 			use_sg = false;
1470 	}
1471 
1472 	musb_ep_select(mbase, epnum);
1473 	musb_writew(epio, MUSB_TXCSR,
1474 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1475 }
1476 
1477 
1478 #ifdef CONFIG_USB_INVENTRA_DMA
1479 
1480 /* Host side RX (IN) using Mentor DMA works as follows:
1481 	submit_urb ->
1482 		- if queue was empty, ProgramEndpoint
1483 		- first IN token is sent out (by setting ReqPkt)
1484 	LinuxIsr -> RxReady()
1485 	/\	=> first packet is received
1486 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1487 	|		-> DMA Isr (transfer complete) -> RxReady()
1488 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1489 	|		    - if urb not complete, send next IN token (ReqPkt)
1490 	|			   |		else complete urb.
1491 	|			   |
1492 	---------------------------
1493  *
1494  * Nuances of mode 1:
1495  *	For short packets, no ack (+RxPktRdy) is sent automatically
1496  *	(even if AutoClear is ON)
1497  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1498  *	automatically => major problem, as collecting the next packet becomes
1499  *	difficult. Hence mode 1 is not used.
1500  *
1501  * REVISIT
1502  *	All we care about at this driver level is that
1503  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1504  *       (b) termination conditions are: short RX, or buffer full;
1505  *       (c) fault modes include
1506  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1507  *             (and that endpoint's dma queue stops immediately)
1508  *           - overflow (full, PLUS more bytes in the terminal packet)
1509  *
1510  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1511  *	thus be a great candidate for using mode 1 ... for all but the
1512  *	last packet of one URB's transfer.
1513  */
1514 
1515 #endif
1516 
1517 /*
1518  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1519  * and high-bandwidth IN transfer cases.
1520  */
1521 void musb_host_rx(struct musb *musb, u8 epnum)
1522 {
1523 	struct urb		*urb;
1524 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1525 	void __iomem		*epio = hw_ep->regs;
1526 	struct musb_qh		*qh = hw_ep->in_qh;
1527 	size_t			xfer_len;
1528 	void __iomem		*mbase = musb->mregs;
1529 	int			pipe;
1530 	u16			rx_csr, val;
1531 	bool			iso_err = false;
1532 	bool			done = false;
1533 	u32			status;
1534 	struct dma_channel	*dma;
1535 	static bool use_sg;
1536 	unsigned int sg_flags = SG_MITER_ATOMIC | SG_MITER_TO_SG;
1537 
1538 	musb_ep_select(mbase, epnum);
1539 
1540 	urb = next_urb(qh);
1541 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1542 	status = 0;
1543 	xfer_len = 0;
1544 
1545 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1546 	val = rx_csr;
1547 
1548 	if (unlikely(!urb)) {
1549 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1550 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1551 		 * with fifo full.  (Only with DMA??)
1552 		 */
1553 		dev_dbg(musb->controller, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
1554 			musb_readw(epio, MUSB_RXCOUNT));
1555 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1556 		return;
1557 	}
1558 
1559 	pipe = urb->pipe;
1560 
1561 	dev_dbg(musb->controller, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
1562 		epnum, rx_csr, urb->actual_length,
1563 		dma ? dma->actual_len : 0);
1564 
1565 	/* check for errors, concurrent stall & unlink is not really
1566 	 * handled yet! */
1567 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1568 		dev_dbg(musb->controller, "RX end %d STALL\n", epnum);
1569 
1570 		/* stall; record URB status */
1571 		status = -EPIPE;
1572 
1573 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1574 		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
1575 
1576 		status = -EPROTO;
1577 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1578 
1579 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1580 
1581 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1582 			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
1583 
1584 			/* NOTE: NAKing is *NOT* an error, so we want to
1585 			 * continue.  Except ... if there's a request for
1586 			 * another QH, use that instead of starving it.
1587 			 *
1588 			 * Devices like Ethernet and serial adapters keep
1589 			 * reads posted at all times, which will starve
1590 			 * other devices without this logic.
1591 			 */
1592 			if (usb_pipebulk(urb->pipe)
1593 					&& qh->mux == 1
1594 					&& !list_is_singular(&musb->in_bulk)) {
1595 				musb_bulk_nak_timeout(musb, hw_ep, 1);
1596 				return;
1597 			}
1598 			musb_ep_select(mbase, epnum);
1599 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1600 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1601 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1602 
1603 			goto finish;
1604 		} else {
1605 			dev_dbg(musb->controller, "RX end %d ISO data error\n", epnum);
1606 			/* packet error reported later */
1607 			iso_err = true;
1608 		}
1609 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1610 		dev_dbg(musb->controller, "end %d high bandwidth incomplete ISO packet RX\n",
1611 				epnum);
1612 		status = -EPROTO;
1613 	}
1614 
1615 	/* faults abort the transfer */
1616 	if (status) {
1617 		/* clean up dma and collect transfer count */
1618 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1619 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1620 			(void) musb->dma_controller->channel_abort(dma);
1621 			xfer_len = dma->actual_len;
1622 		}
1623 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1624 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1625 		done = true;
1626 		goto finish;
1627 	}
1628 
1629 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1630 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1631 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1632 		goto finish;
1633 	}
1634 
1635 	/* thorough shutdown for now ... given more precise fault handling
1636 	 * and better queueing support, we might keep a DMA pipeline going
1637 	 * while processing this irq for earlier completions.
1638 	 */
1639 
1640 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1641 
1642 #ifndef CONFIG_USB_INVENTRA_DMA
1643 	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
1644 		/* REVISIT this happened for a while on some short reads...
1645 		 * the cleanup still needs investigation... looks bad...
1646 		 * and also duplicates dma cleanup code above ... plus,
1647 		 * shouldn't this be the "half full" double buffer case?
1648 		 */
1649 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1650 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1651 			(void) musb->dma_controller->channel_abort(dma);
1652 			xfer_len = dma->actual_len;
1653 			done = true;
1654 		}
1655 
1656 		dev_dbg(musb->controller, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
1657 				xfer_len, dma ? ", dma" : "");
1658 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1659 
1660 		musb_ep_select(mbase, epnum);
1661 		musb_writew(epio, MUSB_RXCSR,
1662 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1663 	}
1664 #endif
1665 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1666 		xfer_len = dma->actual_len;
1667 
1668 		val &= ~(MUSB_RXCSR_DMAENAB
1669 			| MUSB_RXCSR_H_AUTOREQ
1670 			| MUSB_RXCSR_AUTOCLEAR
1671 			| MUSB_RXCSR_RXPKTRDY);
1672 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1673 
1674 #ifdef CONFIG_USB_INVENTRA_DMA
1675 		if (usb_pipeisoc(pipe)) {
1676 			struct usb_iso_packet_descriptor *d;
1677 
1678 			d = urb->iso_frame_desc + qh->iso_idx;
1679 			d->actual_length = xfer_len;
1680 
1681 			/* even if there was an error, we did the dma
1682 			 * for iso_frame_desc->length
1683 			 */
1684 			if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1685 				d->status = 0;
1686 
1687 			if (++qh->iso_idx >= urb->number_of_packets)
1688 				done = true;
1689 			else
1690 				done = false;
1691 
1692 		} else  {
1693 		/* done if urb buffer is full or short packet is recd */
1694 		done = (urb->actual_length + xfer_len >=
1695 				urb->transfer_buffer_length
1696 			|| dma->actual_len < qh->maxpacket);
1697 		}
1698 
1699 		/* send IN token for next packet, without AUTOREQ */
1700 		if (!done) {
1701 			val |= MUSB_RXCSR_H_REQPKT;
1702 			musb_writew(epio, MUSB_RXCSR,
1703 				MUSB_RXCSR_H_WZC_BITS | val);
1704 		}
1705 
1706 		dev_dbg(musb->controller, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
1707 			done ? "off" : "reset",
1708 			musb_readw(epio, MUSB_RXCSR),
1709 			musb_readw(epio, MUSB_RXCOUNT));
1710 #else
1711 		done = true;
1712 #endif
1713 	} else if (urb->status == -EINPROGRESS) {
1714 		/* if no errors, be sure a packet is ready for unloading */
1715 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1716 			status = -EPROTO;
1717 			ERR("Rx interrupt with no errors or packet!\n");
1718 
1719 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1720 
1721 /* SCRUB (RX) */
1722 			/* do the proper sequence to abort the transfer */
1723 			musb_ep_select(mbase, epnum);
1724 			val &= ~MUSB_RXCSR_H_REQPKT;
1725 			musb_writew(epio, MUSB_RXCSR, val);
1726 			goto finish;
1727 		}
1728 
1729 		/* we are expecting IN packets */
1730 #ifdef CONFIG_USB_INVENTRA_DMA
1731 		if (dma) {
1732 			struct dma_controller	*c;
1733 			u16			rx_count;
1734 			int			ret, length;
1735 			dma_addr_t		buf;
1736 
1737 			rx_count = musb_readw(epio, MUSB_RXCOUNT);
1738 
1739 			dev_dbg(musb->controller, "RX%d count %d, buffer 0x%x len %d/%d\n",
1740 					epnum, rx_count,
1741 					urb->transfer_dma
1742 						+ urb->actual_length,
1743 					qh->offset,
1744 					urb->transfer_buffer_length);
1745 
1746 			c = musb->dma_controller;
1747 
1748 			if (usb_pipeisoc(pipe)) {
1749 				int d_status = 0;
1750 				struct usb_iso_packet_descriptor *d;
1751 
1752 				d = urb->iso_frame_desc + qh->iso_idx;
1753 
1754 				if (iso_err) {
1755 					d_status = -EILSEQ;
1756 					urb->error_count++;
1757 				}
1758 				if (rx_count > d->length) {
1759 					if (d_status == 0) {
1760 						d_status = -EOVERFLOW;
1761 						urb->error_count++;
1762 					}
1763 					dev_dbg(musb->controller, "** OVERFLOW %d into %d\n",\
1764 					    rx_count, d->length);
1765 
1766 					length = d->length;
1767 				} else
1768 					length = rx_count;
1769 				d->status = d_status;
1770 				buf = urb->transfer_dma + d->offset;
1771 			} else {
1772 				length = rx_count;
1773 				buf = urb->transfer_dma +
1774 						urb->actual_length;
1775 			}
1776 
1777 			dma->desired_mode = 0;
1778 #ifdef USE_MODE1
1779 			/* because of the issue below, mode 1 will
1780 			 * only rarely behave with correct semantics.
1781 			 */
1782 			if ((urb->transfer_flags &
1783 						URB_SHORT_NOT_OK)
1784 				&& (urb->transfer_buffer_length -
1785 						urb->actual_length)
1786 					> qh->maxpacket)
1787 				dma->desired_mode = 1;
1788 			if (rx_count < hw_ep->max_packet_sz_rx) {
1789 				length = rx_count;
1790 				dma->desired_mode = 0;
1791 			} else {
1792 				length = urb->transfer_buffer_length;
1793 			}
1794 #endif
1795 
1796 /* Disadvantage of using mode 1:
1797  *	It's basically usable only for mass storage class; essentially all
1798  *	other protocols also terminate transfers on short packets.
1799  *
1800  * Details:
1801  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1802  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1803  *	to use the extra IN token to grab the last packet using mode 0, then
1804  *	the problem is that you cannot be sure when the device will send the
1805  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1806  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1807  *	transfer, while sometimes it is recd just a little late so that if you
1808  *	try to configure for mode 0 soon after the mode 1 transfer is
1809  *	completed, you will find rxcount 0. Okay, so you might think why not
1810  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1811  */
1812 
1813 			val = musb_readw(epio, MUSB_RXCSR);
1814 			val &= ~MUSB_RXCSR_H_REQPKT;
1815 
1816 			if (dma->desired_mode == 0)
1817 				val &= ~MUSB_RXCSR_H_AUTOREQ;
1818 			else
1819 				val |= MUSB_RXCSR_H_AUTOREQ;
1820 			val |= MUSB_RXCSR_DMAENAB;
1821 
1822 			/* autoclear shouldn't be set in high bandwidth */
1823 			if (qh->hb_mult == 1)
1824 				val |= MUSB_RXCSR_AUTOCLEAR;
1825 
1826 			musb_writew(epio, MUSB_RXCSR,
1827 				MUSB_RXCSR_H_WZC_BITS | val);
1828 
1829 			/* REVISIT if when actual_length != 0,
1830 			 * transfer_buffer_length needs to be
1831 			 * adjusted first...
1832 			 */
1833 			ret = c->channel_program(
1834 				dma, qh->maxpacket,
1835 				dma->desired_mode, buf, length);
1836 
1837 			if (!ret) {
1838 				c->channel_release(dma);
1839 				hw_ep->rx_channel = NULL;
1840 				dma = NULL;
1841 				val = musb_readw(epio, MUSB_RXCSR);
1842 				val &= ~(MUSB_RXCSR_DMAENAB
1843 					| MUSB_RXCSR_H_AUTOREQ
1844 					| MUSB_RXCSR_AUTOCLEAR);
1845 				musb_writew(epio, MUSB_RXCSR, val);
1846 			}
1847 		}
1848 #endif	/* Mentor DMA */
1849 
1850 		if (!dma) {
1851 			unsigned int received_len;
1852 
1853 			/* Unmap the buffer so that CPU can use it */
1854 			usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1855 
1856 			/*
1857 			 * We need to map sg if the transfer_buffer is
1858 			 * NULL.
1859 			 */
1860 			if (!urb->transfer_buffer) {
1861 				use_sg = true;
1862 				sg_miter_start(&qh->sg_miter, urb->sg, 1,
1863 						sg_flags);
1864 			}
1865 
1866 			if (use_sg) {
1867 				if (!sg_miter_next(&qh->sg_miter)) {
1868 					dev_err(musb->controller, "error: sg list empty\n");
1869 					sg_miter_stop(&qh->sg_miter);
1870 					status = -EINVAL;
1871 					done = true;
1872 					goto finish;
1873 				}
1874 				urb->transfer_buffer = qh->sg_miter.addr;
1875 				received_len = urb->actual_length;
1876 				qh->offset = 0x0;
1877 				done = musb_host_packet_rx(musb, urb, epnum,
1878 						iso_err);
1879 				/* Calculate the number of bytes received */
1880 				received_len = urb->actual_length -
1881 					received_len;
1882 				qh->sg_miter.consumed = received_len;
1883 				sg_miter_stop(&qh->sg_miter);
1884 			} else {
1885 				done = musb_host_packet_rx(musb, urb,
1886 						epnum, iso_err);
1887 			}
1888 			dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
1889 		}
1890 	}
1891 
1892 finish:
1893 	urb->actual_length += xfer_len;
1894 	qh->offset += xfer_len;
1895 	if (done) {
1896 		if (use_sg)
1897 			use_sg = false;
1898 
1899 		if (urb->status == -EINPROGRESS)
1900 			urb->status = status;
1901 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1902 	}
1903 }
1904 
1905 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1906  * the software schedule associates multiple such nodes with a given
1907  * host side hardware endpoint + direction; scheduling may activate
1908  * that hardware endpoint.
1909  */
1910 static int musb_schedule(
1911 	struct musb		*musb,
1912 	struct musb_qh		*qh,
1913 	int			is_in)
1914 {
1915 	int			idle;
1916 	int			best_diff;
1917 	int			best_end, epnum;
1918 	struct musb_hw_ep	*hw_ep = NULL;
1919 	struct list_head	*head = NULL;
1920 	u8			toggle;
1921 	u8			txtype;
1922 	struct urb		*urb = next_urb(qh);
1923 
1924 	/* use fixed hardware for control and bulk */
1925 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1926 		head = &musb->control;
1927 		hw_ep = musb->control_ep;
1928 		goto success;
1929 	}
1930 
1931 	/* else, periodic transfers get muxed to other endpoints */
1932 
1933 	/*
1934 	 * We know this qh hasn't been scheduled, so all we need to do
1935 	 * is choose which hardware endpoint to put it on ...
1936 	 *
1937 	 * REVISIT what we really want here is a regular schedule tree
1938 	 * like e.g. OHCI uses.
1939 	 */
1940 	best_diff = 4096;
1941 	best_end = -1;
1942 
1943 	for (epnum = 1, hw_ep = musb->endpoints + 1;
1944 			epnum < musb->nr_endpoints;
1945 			epnum++, hw_ep++) {
1946 		int	diff;
1947 
1948 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
1949 			continue;
1950 
1951 		if (hw_ep == musb->bulk_ep)
1952 			continue;
1953 
1954 		if (is_in)
1955 			diff = hw_ep->max_packet_sz_rx;
1956 		else
1957 			diff = hw_ep->max_packet_sz_tx;
1958 		diff -= (qh->maxpacket * qh->hb_mult);
1959 
1960 		if (diff >= 0 && best_diff > diff) {
1961 
1962 			/*
1963 			 * Mentor controller has a bug in that if we schedule
1964 			 * a BULK Tx transfer on an endpoint that had earlier
1965 			 * handled ISOC then the BULK transfer has to start on
1966 			 * a zero toggle.  If the BULK transfer starts on a 1
1967 			 * toggle then this transfer will fail as the mentor
1968 			 * controller starts the Bulk transfer on a 0 toggle
1969 			 * irrespective of the programming of the toggle bits
1970 			 * in the TXCSR register.  Check for this condition
1971 			 * while allocating the EP for a Tx Bulk transfer.  If
1972 			 * so skip this EP.
1973 			 */
1974 			hw_ep = musb->endpoints + epnum;
1975 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
1976 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
1977 					>> 4) & 0x3;
1978 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
1979 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
1980 				continue;
1981 
1982 			best_diff = diff;
1983 			best_end = epnum;
1984 		}
1985 	}
1986 	/* use bulk reserved ep1 if no other ep is free */
1987 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
1988 		hw_ep = musb->bulk_ep;
1989 		if (is_in)
1990 			head = &musb->in_bulk;
1991 		else
1992 			head = &musb->out_bulk;
1993 
1994 		/* Enable bulk RX/TX NAK timeout scheme when bulk requests are
1995 		 * multiplexed.  This scheme doen't work in high speed to full
1996 		 * speed scenario as NAK interrupts are not coming from a
1997 		 * full speed device connected to a high speed device.
1998 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
1999 		 * 4 (8 frame or 8ms) for FS device.
2000 		 */
2001 		if (qh->dev)
2002 			qh->intv_reg =
2003 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
2004 		goto success;
2005 	} else if (best_end < 0) {
2006 		return -ENOSPC;
2007 	}
2008 
2009 	idle = 1;
2010 	qh->mux = 0;
2011 	hw_ep = musb->endpoints + best_end;
2012 	dev_dbg(musb->controller, "qh %p periodic slot %d\n", qh, best_end);
2013 success:
2014 	if (head) {
2015 		idle = list_empty(head);
2016 		list_add_tail(&qh->ring, head);
2017 		qh->mux = 1;
2018 	}
2019 	qh->hw_ep = hw_ep;
2020 	qh->hep->hcpriv = qh;
2021 	if (idle)
2022 		musb_start_urb(musb, is_in, qh);
2023 	return 0;
2024 }
2025 
2026 static int musb_urb_enqueue(
2027 	struct usb_hcd			*hcd,
2028 	struct urb			*urb,
2029 	gfp_t				mem_flags)
2030 {
2031 	unsigned long			flags;
2032 	struct musb			*musb = hcd_to_musb(hcd);
2033 	struct usb_host_endpoint	*hep = urb->ep;
2034 	struct musb_qh			*qh;
2035 	struct usb_endpoint_descriptor	*epd = &hep->desc;
2036 	int				ret;
2037 	unsigned			type_reg;
2038 	unsigned			interval;
2039 
2040 	/* host role must be active */
2041 	if (!is_host_active(musb) || !musb->is_active)
2042 		return -ENODEV;
2043 
2044 	spin_lock_irqsave(&musb->lock, flags);
2045 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
2046 	qh = ret ? NULL : hep->hcpriv;
2047 	if (qh)
2048 		urb->hcpriv = qh;
2049 	spin_unlock_irqrestore(&musb->lock, flags);
2050 
2051 	/* DMA mapping was already done, if needed, and this urb is on
2052 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
2053 	 * scheduled onto a live qh.
2054 	 *
2055 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
2056 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
2057 	 * except for the first urb queued after a config change.
2058 	 */
2059 	if (qh || ret)
2060 		return ret;
2061 
2062 	/* Allocate and initialize qh, minimizing the work done each time
2063 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
2064 	 *
2065 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
2066 	 * for bugs in other kernel code to break this driver...
2067 	 */
2068 	qh = kzalloc(sizeof *qh, mem_flags);
2069 	if (!qh) {
2070 		spin_lock_irqsave(&musb->lock, flags);
2071 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2072 		spin_unlock_irqrestore(&musb->lock, flags);
2073 		return -ENOMEM;
2074 	}
2075 
2076 	qh->hep = hep;
2077 	qh->dev = urb->dev;
2078 	INIT_LIST_HEAD(&qh->ring);
2079 	qh->is_ready = 1;
2080 
2081 	qh->maxpacket = usb_endpoint_maxp(epd);
2082 	qh->type = usb_endpoint_type(epd);
2083 
2084 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
2085 	 * Some musb cores don't support high bandwidth ISO transfers; and
2086 	 * we don't (yet!) support high bandwidth interrupt transfers.
2087 	 */
2088 	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
2089 	if (qh->hb_mult > 1) {
2090 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
2091 
2092 		if (ok)
2093 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
2094 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
2095 		if (!ok) {
2096 			ret = -EMSGSIZE;
2097 			goto done;
2098 		}
2099 		qh->maxpacket &= 0x7ff;
2100 	}
2101 
2102 	qh->epnum = usb_endpoint_num(epd);
2103 
2104 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
2105 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
2106 
2107 	/* precompute rxtype/txtype/type0 register */
2108 	type_reg = (qh->type << 4) | qh->epnum;
2109 	switch (urb->dev->speed) {
2110 	case USB_SPEED_LOW:
2111 		type_reg |= 0xc0;
2112 		break;
2113 	case USB_SPEED_FULL:
2114 		type_reg |= 0x80;
2115 		break;
2116 	default:
2117 		type_reg |= 0x40;
2118 	}
2119 	qh->type_reg = type_reg;
2120 
2121 	/* Precompute RXINTERVAL/TXINTERVAL register */
2122 	switch (qh->type) {
2123 	case USB_ENDPOINT_XFER_INT:
2124 		/*
2125 		 * Full/low speeds use the  linear encoding,
2126 		 * high speed uses the logarithmic encoding.
2127 		 */
2128 		if (urb->dev->speed <= USB_SPEED_FULL) {
2129 			interval = max_t(u8, epd->bInterval, 1);
2130 			break;
2131 		}
2132 		/* FALLTHROUGH */
2133 	case USB_ENDPOINT_XFER_ISOC:
2134 		/* ISO always uses logarithmic encoding */
2135 		interval = min_t(u8, epd->bInterval, 16);
2136 		break;
2137 	default:
2138 		/* REVISIT we actually want to use NAK limits, hinting to the
2139 		 * transfer scheduling logic to try some other qh, e.g. try
2140 		 * for 2 msec first:
2141 		 *
2142 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2143 		 *
2144 		 * The downside of disabling this is that transfer scheduling
2145 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2146 		 * peripheral could make that hurt.  That's perfectly normal
2147 		 * for reads from network or serial adapters ... so we have
2148 		 * partial NAKlimit support for bulk RX.
2149 		 *
2150 		 * The upside of disabling it is simpler transfer scheduling.
2151 		 */
2152 		interval = 0;
2153 	}
2154 	qh->intv_reg = interval;
2155 
2156 	/* precompute addressing for external hub/tt ports */
2157 	if (musb->is_multipoint) {
2158 		struct usb_device	*parent = urb->dev->parent;
2159 
2160 		if (parent != hcd->self.root_hub) {
2161 			qh->h_addr_reg = (u8) parent->devnum;
2162 
2163 			/* set up tt info if needed */
2164 			if (urb->dev->tt) {
2165 				qh->h_port_reg = (u8) urb->dev->ttport;
2166 				if (urb->dev->tt->hub)
2167 					qh->h_addr_reg =
2168 						(u8) urb->dev->tt->hub->devnum;
2169 				if (urb->dev->tt->multi)
2170 					qh->h_addr_reg |= 0x80;
2171 			}
2172 		}
2173 	}
2174 
2175 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2176 	 * until we get real dma queues (with an entry for each urb/buffer),
2177 	 * we only have work to do in the former case.
2178 	 */
2179 	spin_lock_irqsave(&musb->lock, flags);
2180 	if (hep->hcpriv || !next_urb(qh)) {
2181 		/* some concurrent activity submitted another urb to hep...
2182 		 * odd, rare, error prone, but legal.
2183 		 */
2184 		kfree(qh);
2185 		qh = NULL;
2186 		ret = 0;
2187 	} else
2188 		ret = musb_schedule(musb, qh,
2189 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2190 
2191 	if (ret == 0) {
2192 		urb->hcpriv = qh;
2193 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2194 		 * musb_start_urb(), but otherwise only konicawc cares ...
2195 		 */
2196 	}
2197 	spin_unlock_irqrestore(&musb->lock, flags);
2198 
2199 done:
2200 	if (ret != 0) {
2201 		spin_lock_irqsave(&musb->lock, flags);
2202 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2203 		spin_unlock_irqrestore(&musb->lock, flags);
2204 		kfree(qh);
2205 	}
2206 	return ret;
2207 }
2208 
2209 
2210 /*
2211  * abort a transfer that's at the head of a hardware queue.
2212  * called with controller locked, irqs blocked
2213  * that hardware queue advances to the next transfer, unless prevented
2214  */
2215 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2216 {
2217 	struct musb_hw_ep	*ep = qh->hw_ep;
2218 	struct musb		*musb = ep->musb;
2219 	void __iomem		*epio = ep->regs;
2220 	unsigned		hw_end = ep->epnum;
2221 	void __iomem		*regs = ep->musb->mregs;
2222 	int			is_in = usb_pipein(urb->pipe);
2223 	int			status = 0;
2224 	u16			csr;
2225 
2226 	musb_ep_select(regs, hw_end);
2227 
2228 	if (is_dma_capable()) {
2229 		struct dma_channel	*dma;
2230 
2231 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2232 		if (dma) {
2233 			status = ep->musb->dma_controller->channel_abort(dma);
2234 			dev_dbg(musb->controller,
2235 				"abort %cX%d DMA for urb %p --> %d\n",
2236 				is_in ? 'R' : 'T', ep->epnum,
2237 				urb, status);
2238 			urb->actual_length += dma->actual_len;
2239 		}
2240 	}
2241 
2242 	/* turn off DMA requests, discard state, stop polling ... */
2243 	if (ep->epnum && is_in) {
2244 		/* giveback saves bulk toggle */
2245 		csr = musb_h_flush_rxfifo(ep, 0);
2246 
2247 		/* REVISIT we still get an irq; should likely clear the
2248 		 * endpoint's irq status here to avoid bogus irqs.
2249 		 * clearing that status is platform-specific...
2250 		 */
2251 	} else if (ep->epnum) {
2252 		musb_h_tx_flush_fifo(ep);
2253 		csr = musb_readw(epio, MUSB_TXCSR);
2254 		csr &= ~(MUSB_TXCSR_AUTOSET
2255 			| MUSB_TXCSR_DMAENAB
2256 			| MUSB_TXCSR_H_RXSTALL
2257 			| MUSB_TXCSR_H_NAKTIMEOUT
2258 			| MUSB_TXCSR_H_ERROR
2259 			| MUSB_TXCSR_TXPKTRDY);
2260 		musb_writew(epio, MUSB_TXCSR, csr);
2261 		/* REVISIT may need to clear FLUSHFIFO ... */
2262 		musb_writew(epio, MUSB_TXCSR, csr);
2263 		/* flush cpu writebuffer */
2264 		csr = musb_readw(epio, MUSB_TXCSR);
2265 	} else  {
2266 		musb_h_ep0_flush_fifo(ep);
2267 	}
2268 	if (status == 0)
2269 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2270 	return status;
2271 }
2272 
2273 static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
2274 {
2275 	struct musb		*musb = hcd_to_musb(hcd);
2276 	struct musb_qh		*qh;
2277 	unsigned long		flags;
2278 	int			is_in  = usb_pipein(urb->pipe);
2279 	int			ret;
2280 
2281 	dev_dbg(musb->controller, "urb=%p, dev%d ep%d%s\n", urb,
2282 			usb_pipedevice(urb->pipe),
2283 			usb_pipeendpoint(urb->pipe),
2284 			is_in ? "in" : "out");
2285 
2286 	spin_lock_irqsave(&musb->lock, flags);
2287 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2288 	if (ret)
2289 		goto done;
2290 
2291 	qh = urb->hcpriv;
2292 	if (!qh)
2293 		goto done;
2294 
2295 	/*
2296 	 * Any URB not actively programmed into endpoint hardware can be
2297 	 * immediately given back; that's any URB not at the head of an
2298 	 * endpoint queue, unless someday we get real DMA queues.  And even
2299 	 * if it's at the head, it might not be known to the hardware...
2300 	 *
2301 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2302 	 * has already been updated.  This is a synchronous abort; it'd be
2303 	 * OK to hold off until after some IRQ, though.
2304 	 *
2305 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2306 	 */
2307 	if (!qh->is_ready
2308 			|| urb->urb_list.prev != &qh->hep->urb_list
2309 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2310 		int	ready = qh->is_ready;
2311 
2312 		qh->is_ready = 0;
2313 		musb_giveback(musb, urb, 0);
2314 		qh->is_ready = ready;
2315 
2316 		/* If nothing else (usually musb_giveback) is using it
2317 		 * and its URB list has emptied, recycle this qh.
2318 		 */
2319 		if (ready && list_empty(&qh->hep->urb_list)) {
2320 			qh->hep->hcpriv = NULL;
2321 			list_del(&qh->ring);
2322 			kfree(qh);
2323 		}
2324 	} else
2325 		ret = musb_cleanup_urb(urb, qh);
2326 done:
2327 	spin_unlock_irqrestore(&musb->lock, flags);
2328 	return ret;
2329 }
2330 
2331 /* disable an endpoint */
2332 static void
2333 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2334 {
2335 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2336 	unsigned long		flags;
2337 	struct musb		*musb = hcd_to_musb(hcd);
2338 	struct musb_qh		*qh;
2339 	struct urb		*urb;
2340 
2341 	spin_lock_irqsave(&musb->lock, flags);
2342 
2343 	qh = hep->hcpriv;
2344 	if (qh == NULL)
2345 		goto exit;
2346 
2347 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2348 
2349 	/* Kick the first URB off the hardware, if needed */
2350 	qh->is_ready = 0;
2351 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2352 		urb = next_urb(qh);
2353 
2354 		/* make software (then hardware) stop ASAP */
2355 		if (!urb->unlinked)
2356 			urb->status = -ESHUTDOWN;
2357 
2358 		/* cleanup */
2359 		musb_cleanup_urb(urb, qh);
2360 
2361 		/* Then nuke all the others ... and advance the
2362 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2363 		 */
2364 		while (!list_empty(&hep->urb_list)) {
2365 			urb = next_urb(qh);
2366 			urb->status = -ESHUTDOWN;
2367 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2368 		}
2369 	} else {
2370 		/* Just empty the queue; the hardware is busy with
2371 		 * other transfers, and since !qh->is_ready nothing
2372 		 * will activate any of these as it advances.
2373 		 */
2374 		while (!list_empty(&hep->urb_list))
2375 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2376 
2377 		hep->hcpriv = NULL;
2378 		list_del(&qh->ring);
2379 		kfree(qh);
2380 	}
2381 exit:
2382 	spin_unlock_irqrestore(&musb->lock, flags);
2383 }
2384 
2385 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2386 {
2387 	struct musb	*musb = hcd_to_musb(hcd);
2388 
2389 	return musb_readw(musb->mregs, MUSB_FRAME);
2390 }
2391 
2392 static int musb_h_start(struct usb_hcd *hcd)
2393 {
2394 	struct musb	*musb = hcd_to_musb(hcd);
2395 
2396 	/* NOTE: musb_start() is called when the hub driver turns
2397 	 * on port power, or when (OTG) peripheral starts.
2398 	 */
2399 	hcd->state = HC_STATE_RUNNING;
2400 	musb->port1_status = 0;
2401 	return 0;
2402 }
2403 
2404 static void musb_h_stop(struct usb_hcd *hcd)
2405 {
2406 	musb_stop(hcd_to_musb(hcd));
2407 	hcd->state = HC_STATE_HALT;
2408 }
2409 
2410 static int musb_bus_suspend(struct usb_hcd *hcd)
2411 {
2412 	struct musb	*musb = hcd_to_musb(hcd);
2413 	u8		devctl;
2414 
2415 	if (!is_host_active(musb))
2416 		return 0;
2417 
2418 	switch (musb->xceiv->state) {
2419 	case OTG_STATE_A_SUSPEND:
2420 		return 0;
2421 	case OTG_STATE_A_WAIT_VRISE:
2422 		/* ID could be grounded even if there's no device
2423 		 * on the other end of the cable.  NOTE that the
2424 		 * A_WAIT_VRISE timers are messy with MUSB...
2425 		 */
2426 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2427 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2428 			musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2429 		break;
2430 	default:
2431 		break;
2432 	}
2433 
2434 	if (musb->is_active) {
2435 		WARNING("trying to suspend as %s while active\n",
2436 				otg_state_string(musb->xceiv->state));
2437 		return -EBUSY;
2438 	} else
2439 		return 0;
2440 }
2441 
2442 static int musb_bus_resume(struct usb_hcd *hcd)
2443 {
2444 	/* resuming child port does the work */
2445 	return 0;
2446 }
2447 
2448 const struct hc_driver musb_hc_driver = {
2449 	.description		= "musb-hcd",
2450 	.product_desc		= "MUSB HDRC host driver",
2451 	.hcd_priv_size		= sizeof(struct musb),
2452 	.flags			= HCD_USB2 | HCD_MEMORY,
2453 
2454 	/* not using irq handler or reset hooks from usbcore, since
2455 	 * those must be shared with peripheral code for OTG configs
2456 	 */
2457 
2458 	.start			= musb_h_start,
2459 	.stop			= musb_h_stop,
2460 
2461 	.get_frame_number	= musb_h_get_frame_number,
2462 
2463 	.urb_enqueue		= musb_urb_enqueue,
2464 	.urb_dequeue		= musb_urb_dequeue,
2465 	.endpoint_disable	= musb_h_disable,
2466 
2467 	.hub_status_data	= musb_hub_status_data,
2468 	.hub_control		= musb_hub_control,
2469 	.bus_suspend		= musb_bus_suspend,
2470 	.bus_resume		= musb_bus_resume,
2471 	/* .start_port_reset	= NULL, */
2472 	/* .hub_irq_enable	= NULL, */
2473 };
2474