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  * SPDX-License-Identifier:	GPL-2.0
10  */
11 
12 #ifndef __UBOOT__
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/delay.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/errno.h>
19 #include <linux/init.h>
20 #include <linux/list.h>
21 #include <linux/dma-mapping.h>
22 #else
23 #include <common.h>
24 #include <usb.h>
25 #include "linux-compat.h"
26 #include "usb-compat.h"
27 #endif
28 
29 #include "musb_core.h"
30 #include "musb_host.h"
31 
32 
33 /* MUSB HOST status 22-mar-2006
34  *
35  * - There's still lots of partial code duplication for fault paths, so
36  *   they aren't handled as consistently as they need to be.
37  *
38  * - PIO mostly behaved when last tested.
39  *     + including ep0, with all usbtest cases 9, 10
40  *     + usbtest 14 (ep0out) doesn't seem to run at all
41  *     + double buffered OUT/TX endpoints saw stalls(!) with certain usbtest
42  *       configurations, but otherwise double buffering passes basic tests.
43  *     + for 2.6.N, for N > ~10, needs API changes for hcd framework.
44  *
45  * - DMA (CPPI) ... partially behaves, not currently recommended
46  *     + about 1/15 the speed of typical EHCI implementations (PCI)
47  *     + RX, all too often reqpkt seems to misbehave after tx
48  *     + TX, no known issues (other than evident silicon issue)
49  *
50  * - DMA (Mentor/OMAP) ...has at least toggle update problems
51  *
52  * - [23-feb-2009] minimal traffic scheduling to avoid bulk RX packet
53  *   starvation ... nothing yet for TX, interrupt, or bulk.
54  *
55  * - Not tested with HNP, but some SRP paths seem to behave.
56  *
57  * NOTE 24-August-2006:
58  *
59  * - Bulk traffic finally uses both sides of hardware ep1, freeing up an
60  *   extra endpoint for periodic use enabling hub + keybd + mouse.  That
61  *   mostly works, except that with "usbnet" it's easy to trigger cases
62  *   with "ping" where RX loses.  (a) ping to davinci, even "ping -f",
63  *   fine; but (b) ping _from_ davinci, even "ping -c 1", ICMP RX loses
64  *   although ARP RX wins.  (That test was done with a full speed link.)
65  */
66 
67 
68 /*
69  * NOTE on endpoint usage:
70  *
71  * CONTROL transfers all go through ep0.  BULK ones go through dedicated IN
72  * and OUT endpoints ... hardware is dedicated for those "async" queue(s).
73  * (Yes, bulk _could_ use more of the endpoints than that, and would even
74  * benefit from it.)
75  *
76  * INTERUPPT and ISOCHRONOUS transfers are scheduled to the other endpoints.
77  * So far that scheduling is both dumb and optimistic:  the endpoint will be
78  * "claimed" until its software queue is no longer refilled.  No multiplexing
79  * of transfers between endpoints, or anything clever.
80  */
81 
82 
83 static void musb_ep_program(struct musb *musb, u8 epnum,
84 			struct urb *urb, int is_out,
85 			u8 *buf, u32 offset, u32 len);
86 
87 /*
88  * Clear TX fifo. Needed to avoid BABBLE errors.
89  */
90 static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
91 {
92 	struct musb	*musb = ep->musb;
93 	void __iomem	*epio = ep->regs;
94 	u16		csr;
95 	u16		lastcsr = 0;
96 	int		retries = 1000;
97 
98 	csr = musb_readw(epio, MUSB_TXCSR);
99 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
100 		if (csr != lastcsr)
101 			dev_dbg(musb->controller, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
102 		lastcsr = csr;
103 		csr |= MUSB_TXCSR_FLUSHFIFO;
104 		musb_writew(epio, MUSB_TXCSR, csr);
105 		csr = musb_readw(epio, MUSB_TXCSR);
106 		if (WARN(retries-- < 1,
107 				"Could not flush host TX%d fifo: csr: %04x\n",
108 				ep->epnum, csr))
109 			return;
110 		mdelay(1);
111 	}
112 }
113 
114 static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
115 {
116 	void __iomem	*epio = ep->regs;
117 	u16		csr;
118 	int		retries = 5;
119 
120 	/* scrub any data left in the fifo */
121 	do {
122 		csr = musb_readw(epio, MUSB_TXCSR);
123 		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
124 			break;
125 		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
126 		csr = musb_readw(epio, MUSB_TXCSR);
127 		udelay(10);
128 	} while (--retries);
129 
130 	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
131 			ep->epnum, csr);
132 
133 	/* and reset for the next transfer */
134 	musb_writew(epio, MUSB_TXCSR, 0);
135 }
136 
137 /*
138  * Start transmit. Caller is responsible for locking shared resources.
139  * musb must be locked.
140  */
141 static inline void musb_h_tx_start(struct musb_hw_ep *ep)
142 {
143 	u16	txcsr;
144 
145 	/* NOTE: no locks here; caller should lock and select EP */
146 	if (ep->epnum) {
147 		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
148 		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
149 		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
150 	} else {
151 		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
152 		musb_writew(ep->regs, MUSB_CSR0, txcsr);
153 	}
154 
155 }
156 
157 static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
158 {
159 	u16	txcsr;
160 
161 	/* NOTE: no locks here; caller should lock and select EP */
162 	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
163 	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
164 	if (is_cppi_enabled())
165 		txcsr |= MUSB_TXCSR_DMAMODE;
166 	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
167 }
168 
169 static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
170 {
171 	if (is_in != 0 || ep->is_shared_fifo)
172 		ep->in_qh  = qh;
173 	if (is_in == 0 || ep->is_shared_fifo)
174 		ep->out_qh = qh;
175 }
176 
177 static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
178 {
179 	return is_in ? ep->in_qh : ep->out_qh;
180 }
181 
182 /*
183  * Start the URB at the front of an endpoint's queue
184  * end must be claimed from the caller.
185  *
186  * Context: controller locked, irqs blocked
187  */
188 static void
189 musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
190 {
191 	u16			frame;
192 	u32			len;
193 	void __iomem		*mbase =  musb->mregs;
194 	struct urb		*urb = next_urb(qh);
195 	void			*buf = urb->transfer_buffer;
196 	u32			offset = 0;
197 	struct musb_hw_ep	*hw_ep = qh->hw_ep;
198 	unsigned		pipe = urb->pipe;
199 	u8			address = usb_pipedevice(pipe);
200 	int			epnum = hw_ep->epnum;
201 
202 	/* initialize software qh state */
203 	qh->offset = 0;
204 	qh->segsize = 0;
205 
206 	/* gather right source of data */
207 	switch (qh->type) {
208 	case USB_ENDPOINT_XFER_CONTROL:
209 		/* control transfers always start with SETUP */
210 		is_in = 0;
211 		musb->ep0_stage = MUSB_EP0_START;
212 		buf = urb->setup_packet;
213 		len = 8;
214 		break;
215 #ifndef __UBOOT__
216 	case USB_ENDPOINT_XFER_ISOC:
217 		qh->iso_idx = 0;
218 		qh->frame = 0;
219 		offset = urb->iso_frame_desc[0].offset;
220 		len = urb->iso_frame_desc[0].length;
221 		break;
222 #endif
223 	default:		/* bulk, interrupt */
224 		/* actual_length may be nonzero on retry paths */
225 		buf = urb->transfer_buffer + urb->actual_length;
226 		len = urb->transfer_buffer_length - urb->actual_length;
227 	}
228 
229 	dev_dbg(musb->controller, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
230 			qh, urb, address, qh->epnum,
231 			is_in ? "in" : "out",
232 			({char *s; switch (qh->type) {
233 			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
234 			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
235 #ifndef __UBOOT__
236 			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
237 #endif
238 			default:			s = "-intr"; break;
239 			}; s; }),
240 			epnum, buf + offset, len);
241 
242 	/* Configure endpoint */
243 	musb_ep_set_qh(hw_ep, is_in, qh);
244 	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
245 
246 	/* transmit may have more work: start it when it is time */
247 	if (is_in)
248 		return;
249 
250 	/* determine if the time is right for a periodic transfer */
251 	switch (qh->type) {
252 #ifndef __UBOOT__
253 	case USB_ENDPOINT_XFER_ISOC:
254 #endif
255 	case USB_ENDPOINT_XFER_INT:
256 		dev_dbg(musb->controller, "check whether there's still time for periodic Tx\n");
257 		frame = musb_readw(mbase, MUSB_FRAME);
258 		/* FIXME this doesn't implement that scheduling policy ...
259 		 * or handle framecounter wrapping
260 		 */
261 #ifndef __UBOOT__
262 		if ((urb->transfer_flags & URB_ISO_ASAP)
263 				|| (frame >= urb->start_frame)) {
264 			/* REVISIT the SOF irq handler shouldn't duplicate
265 			 * this code; and we don't init urb->start_frame...
266 			 */
267 			qh->frame = 0;
268 			goto start;
269 		} else {
270 #endif
271 			qh->frame = urb->start_frame;
272 			/* enable SOF interrupt so we can count down */
273 			dev_dbg(musb->controller, "SOF for %d\n", epnum);
274 #if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
275 			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
276 #endif
277 #ifndef __UBOOT__
278 		}
279 #endif
280 		break;
281 	default:
282 start:
283 		dev_dbg(musb->controller, "Start TX%d %s\n", epnum,
284 			hw_ep->tx_channel ? "dma" : "pio");
285 
286 		if (!hw_ep->tx_channel)
287 			musb_h_tx_start(hw_ep);
288 		else if (is_cppi_enabled() || tusb_dma_omap())
289 			musb_h_tx_dma_start(hw_ep);
290 	}
291 }
292 
293 /* Context: caller owns controller lock, IRQs are blocked */
294 static void musb_giveback(struct musb *musb, struct urb *urb, int status)
295 __releases(musb->lock)
296 __acquires(musb->lock)
297 {
298 	dev_dbg(musb->controller,
299 			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
300 			urb, urb->complete, status,
301 			usb_pipedevice(urb->pipe),
302 			usb_pipeendpoint(urb->pipe),
303 			usb_pipein(urb->pipe) ? "in" : "out",
304 			urb->actual_length, urb->transfer_buffer_length
305 			);
306 
307 	usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
308 	spin_unlock(&musb->lock);
309 	usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
310 	spin_lock(&musb->lock);
311 }
312 
313 /* For bulk/interrupt endpoints only */
314 static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
315 				    struct urb *urb)
316 {
317 	void __iomem		*epio = qh->hw_ep->regs;
318 	u16			csr;
319 
320 	/*
321 	 * FIXME: the current Mentor DMA code seems to have
322 	 * problems getting toggle correct.
323 	 */
324 
325 	if (is_in)
326 		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
327 	else
328 		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
329 
330 	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
331 }
332 
333 /*
334  * Advance this hardware endpoint's queue, completing the specified URB and
335  * advancing to either the next URB queued to that qh, or else invalidating
336  * that qh and advancing to the next qh scheduled after the current one.
337  *
338  * Context: caller owns controller lock, IRQs are blocked
339  */
340 static void musb_advance_schedule(struct musb *musb, struct urb *urb,
341 				  struct musb_hw_ep *hw_ep, int is_in)
342 {
343 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
344 	struct musb_hw_ep	*ep = qh->hw_ep;
345 	int			ready = qh->is_ready;
346 	int			status;
347 
348 	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
349 
350 	/* save toggle eagerly, for paranoia */
351 	switch (qh->type) {
352 	case USB_ENDPOINT_XFER_BULK:
353 	case USB_ENDPOINT_XFER_INT:
354 		musb_save_toggle(qh, is_in, urb);
355 		break;
356 #ifndef __UBOOT__
357 	case USB_ENDPOINT_XFER_ISOC:
358 		if (status == 0 && urb->error_count)
359 			status = -EXDEV;
360 		break;
361 #endif
362 	}
363 
364 	qh->is_ready = 0;
365 	musb_giveback(musb, urb, status);
366 	qh->is_ready = ready;
367 
368 	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
369 	 * invalidate qh as soon as list_empty(&hep->urb_list)
370 	 */
371 	if (list_empty(&qh->hep->urb_list)) {
372 		struct list_head	*head;
373 		struct dma_controller	*dma = musb->dma_controller;
374 
375 		if (is_in) {
376 			ep->rx_reinit = 1;
377 			if (ep->rx_channel) {
378 				dma->channel_release(ep->rx_channel);
379 				ep->rx_channel = NULL;
380 			}
381 		} else {
382 			ep->tx_reinit = 1;
383 			if (ep->tx_channel) {
384 				dma->channel_release(ep->tx_channel);
385 				ep->tx_channel = NULL;
386 			}
387 		}
388 
389 		/* Clobber old pointers to this qh */
390 		musb_ep_set_qh(ep, is_in, NULL);
391 		qh->hep->hcpriv = NULL;
392 
393 		switch (qh->type) {
394 
395 		case USB_ENDPOINT_XFER_CONTROL:
396 		case USB_ENDPOINT_XFER_BULK:
397 			/* fifo policy for these lists, except that NAKing
398 			 * should rotate a qh to the end (for fairness).
399 			 */
400 			if (qh->mux == 1) {
401 				head = qh->ring.prev;
402 				list_del(&qh->ring);
403 				kfree(qh);
404 				qh = first_qh(head);
405 				break;
406 			}
407 
408 		case USB_ENDPOINT_XFER_ISOC:
409 		case USB_ENDPOINT_XFER_INT:
410 			/* this is where periodic bandwidth should be
411 			 * de-allocated if it's tracked and allocated;
412 			 * and where we'd update the schedule tree...
413 			 */
414 			kfree(qh);
415 			qh = NULL;
416 			break;
417 		}
418 	}
419 
420 	if (qh != NULL && qh->is_ready) {
421 		dev_dbg(musb->controller, "... next ep%d %cX urb %p\n",
422 		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
423 		musb_start_urb(musb, is_in, qh);
424 	}
425 }
426 
427 static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
428 {
429 	/* we don't want fifo to fill itself again;
430 	 * ignore dma (various models),
431 	 * leave toggle alone (may not have been saved yet)
432 	 */
433 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
434 	csr &= ~(MUSB_RXCSR_H_REQPKT
435 		| MUSB_RXCSR_H_AUTOREQ
436 		| MUSB_RXCSR_AUTOCLEAR);
437 
438 	/* write 2x to allow double buffering */
439 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
440 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
441 
442 	/* flush writebuffer */
443 	return musb_readw(hw_ep->regs, MUSB_RXCSR);
444 }
445 
446 /*
447  * PIO RX for a packet (or part of it).
448  */
449 static bool
450 musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
451 {
452 	u16			rx_count;
453 	u8			*buf;
454 	u16			csr;
455 	bool			done = false;
456 	u32			length;
457 	int			do_flush = 0;
458 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
459 	void __iomem		*epio = hw_ep->regs;
460 	struct musb_qh		*qh = hw_ep->in_qh;
461 	int			pipe = urb->pipe;
462 	void			*buffer = urb->transfer_buffer;
463 
464 	/* musb_ep_select(mbase, epnum); */
465 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
466 	dev_dbg(musb->controller, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
467 			urb->transfer_buffer, qh->offset,
468 			urb->transfer_buffer_length);
469 
470 	/* unload FIFO */
471 #ifndef __UBOOT__
472 	if (usb_pipeisoc(pipe)) {
473 		int					status = 0;
474 		struct usb_iso_packet_descriptor	*d;
475 
476 		if (iso_err) {
477 			status = -EILSEQ;
478 			urb->error_count++;
479 		}
480 
481 		d = urb->iso_frame_desc + qh->iso_idx;
482 		buf = buffer + d->offset;
483 		length = d->length;
484 		if (rx_count > length) {
485 			if (status == 0) {
486 				status = -EOVERFLOW;
487 				urb->error_count++;
488 			}
489 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
490 			do_flush = 1;
491 		} else
492 			length = rx_count;
493 		urb->actual_length += length;
494 		d->actual_length = length;
495 
496 		d->status = status;
497 
498 		/* see if we are done */
499 		done = (++qh->iso_idx >= urb->number_of_packets);
500 	} else {
501 #endif
502 		/* non-isoch */
503 		buf = buffer + qh->offset;
504 		length = urb->transfer_buffer_length - qh->offset;
505 		if (rx_count > length) {
506 			if (urb->status == -EINPROGRESS)
507 				urb->status = -EOVERFLOW;
508 			dev_dbg(musb->controller, "** OVERFLOW %d into %d\n", rx_count, length);
509 			do_flush = 1;
510 		} else
511 			length = rx_count;
512 		urb->actual_length += length;
513 		qh->offset += length;
514 
515 		/* see if we are done */
516 		done = (urb->actual_length == urb->transfer_buffer_length)
517 			|| (rx_count < qh->maxpacket)
518 			|| (urb->status != -EINPROGRESS);
519 		if (done
520 				&& (urb->status == -EINPROGRESS)
521 				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
522 				&& (urb->actual_length
523 					< urb->transfer_buffer_length))
524 			urb->status = -EREMOTEIO;
525 #ifndef __UBOOT__
526 	}
527 #endif
528 
529 	musb_read_fifo(hw_ep, length, buf);
530 
531 	csr = musb_readw(epio, MUSB_RXCSR);
532 	csr |= MUSB_RXCSR_H_WZC_BITS;
533 	if (unlikely(do_flush))
534 		musb_h_flush_rxfifo(hw_ep, csr);
535 	else {
536 		/* REVISIT this assumes AUTOCLEAR is never set */
537 		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
538 		if (!done)
539 			csr |= MUSB_RXCSR_H_REQPKT;
540 		musb_writew(epio, MUSB_RXCSR, csr);
541 	}
542 
543 	return done;
544 }
545 
546 /* we don't always need to reinit a given side of an endpoint...
547  * when we do, use tx/rx reinit routine and then construct a new CSR
548  * to address data toggle, NYET, and DMA or PIO.
549  *
550  * it's possible that driver bugs (especially for DMA) or aborting a
551  * transfer might have left the endpoint busier than it should be.
552  * the busy/not-empty tests are basically paranoia.
553  */
554 static void
555 musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
556 {
557 	u16	csr;
558 
559 	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
560 	 * That always uses tx_reinit since ep0 repurposes TX register
561 	 * offsets; the initial SETUP packet is also a kind of OUT.
562 	 */
563 
564 	/* if programmed for Tx, put it in RX mode */
565 	if (ep->is_shared_fifo) {
566 		csr = musb_readw(ep->regs, MUSB_TXCSR);
567 		if (csr & MUSB_TXCSR_MODE) {
568 			musb_h_tx_flush_fifo(ep);
569 			csr = musb_readw(ep->regs, MUSB_TXCSR);
570 			musb_writew(ep->regs, MUSB_TXCSR,
571 				    csr | MUSB_TXCSR_FRCDATATOG);
572 		}
573 
574 		/*
575 		 * Clear the MODE bit (and everything else) to enable Rx.
576 		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
577 		 */
578 		if (csr & MUSB_TXCSR_DMAMODE)
579 			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
580 		musb_writew(ep->regs, MUSB_TXCSR, 0);
581 
582 	/* scrub all previous state, clearing toggle */
583 	} else {
584 		csr = musb_readw(ep->regs, MUSB_RXCSR);
585 		if (csr & MUSB_RXCSR_RXPKTRDY)
586 			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
587 				musb_readw(ep->regs, MUSB_RXCOUNT));
588 
589 		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
590 	}
591 
592 	/* target addr and (for multipoint) hub addr/port */
593 	if (musb->is_multipoint) {
594 		musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
595 		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
596 		musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
597 
598 	} else
599 		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
600 
601 	/* protocol/endpoint, interval/NAKlimit, i/o size */
602 	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
603 	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
604 	/* NOTE: bulk combining rewrites high bits of maxpacket */
605 	/* Set RXMAXP with the FIFO size of the endpoint
606 	 * to disable double buffer mode.
607 	 */
608 	if (musb->double_buffer_not_ok)
609 		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
610 	else
611 		musb_writew(ep->regs, MUSB_RXMAXP,
612 				qh->maxpacket | ((qh->hb_mult - 1) << 11));
613 
614 	ep->rx_reinit = 0;
615 }
616 
617 static bool musb_tx_dma_program(struct dma_controller *dma,
618 		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
619 		struct urb *urb, u32 offset, u32 length)
620 {
621 	struct dma_channel	*channel = hw_ep->tx_channel;
622 	void __iomem		*epio = hw_ep->regs;
623 	u16			pkt_size = qh->maxpacket;
624 	u16			csr;
625 	u8			mode;
626 
627 #ifdef	CONFIG_USB_INVENTRA_DMA
628 	if (length > channel->max_len)
629 		length = channel->max_len;
630 
631 	csr = musb_readw(epio, MUSB_TXCSR);
632 	if (length > pkt_size) {
633 		mode = 1;
634 		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
635 		/* autoset shouldn't be set in high bandwidth */
636 		if (qh->hb_mult == 1)
637 			csr |= MUSB_TXCSR_AUTOSET;
638 	} else {
639 		mode = 0;
640 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
641 		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
642 	}
643 	channel->desired_mode = mode;
644 	musb_writew(epio, MUSB_TXCSR, csr);
645 #else
646 	if (!is_cppi_enabled() && !tusb_dma_omap())
647 		return false;
648 
649 	channel->actual_len = 0;
650 
651 	/*
652 	 * TX uses "RNDIS" mode automatically but needs help
653 	 * to identify the zero-length-final-packet case.
654 	 */
655 	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
656 #endif
657 
658 	qh->segsize = length;
659 
660 	/*
661 	 * Ensure the data reaches to main memory before starting
662 	 * DMA transfer
663 	 */
664 	wmb();
665 
666 	if (!dma->channel_program(channel, pkt_size, mode,
667 			urb->transfer_dma + offset, length)) {
668 		dma->channel_release(channel);
669 		hw_ep->tx_channel = NULL;
670 
671 		csr = musb_readw(epio, MUSB_TXCSR);
672 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
673 		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
674 		return false;
675 	}
676 	return true;
677 }
678 
679 /*
680  * Program an HDRC endpoint as per the given URB
681  * Context: irqs blocked, controller lock held
682  */
683 static void musb_ep_program(struct musb *musb, u8 epnum,
684 			struct urb *urb, int is_out,
685 			u8 *buf, u32 offset, u32 len)
686 {
687 	struct dma_controller	*dma_controller;
688 	struct dma_channel	*dma_channel;
689 	u8			dma_ok;
690 	void __iomem		*mbase = musb->mregs;
691 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
692 	void __iomem		*epio = hw_ep->regs;
693 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
694 	u16			packet_sz = qh->maxpacket;
695 
696 	dev_dbg(musb->controller, "%s hw%d urb %p spd%d dev%d ep%d%s "
697 				"h_addr%02x h_port%02x bytes %d\n",
698 			is_out ? "-->" : "<--",
699 			epnum, urb, urb->dev->speed,
700 			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
701 			qh->h_addr_reg, qh->h_port_reg,
702 			len);
703 
704 	musb_ep_select(mbase, epnum);
705 
706 	/* candidate for DMA? */
707 	dma_controller = musb->dma_controller;
708 	if (is_dma_capable() && epnum && dma_controller) {
709 		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
710 		if (!dma_channel) {
711 			dma_channel = dma_controller->channel_alloc(
712 					dma_controller, hw_ep, is_out);
713 			if (is_out)
714 				hw_ep->tx_channel = dma_channel;
715 			else
716 				hw_ep->rx_channel = dma_channel;
717 		}
718 	} else
719 		dma_channel = NULL;
720 
721 	/* make sure we clear DMAEnab, autoSet bits from previous run */
722 
723 	/* OUT/transmit/EP0 or IN/receive? */
724 	if (is_out) {
725 		u16	csr;
726 		u16	int_txe;
727 		u16	load_count;
728 
729 		csr = musb_readw(epio, MUSB_TXCSR);
730 
731 		/* disable interrupt in case we flush */
732 		int_txe = musb_readw(mbase, MUSB_INTRTXE);
733 		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
734 
735 		/* general endpoint setup */
736 		if (epnum) {
737 			/* flush all old state, set default */
738 			musb_h_tx_flush_fifo(hw_ep);
739 
740 			/*
741 			 * We must not clear the DMAMODE bit before or in
742 			 * the same cycle with the DMAENAB bit, so we clear
743 			 * the latter first...
744 			 */
745 			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
746 					| MUSB_TXCSR_AUTOSET
747 					| MUSB_TXCSR_DMAENAB
748 					| MUSB_TXCSR_FRCDATATOG
749 					| MUSB_TXCSR_H_RXSTALL
750 					| MUSB_TXCSR_H_ERROR
751 					| MUSB_TXCSR_TXPKTRDY
752 					);
753 			csr |= MUSB_TXCSR_MODE;
754 
755 			if (usb_gettoggle(urb->dev, qh->epnum, 1))
756 				csr |= MUSB_TXCSR_H_WR_DATATOGGLE
757 					| MUSB_TXCSR_H_DATATOGGLE;
758 			else
759 				csr |= MUSB_TXCSR_CLRDATATOG;
760 
761 			musb_writew(epio, MUSB_TXCSR, csr);
762 			/* REVISIT may need to clear FLUSHFIFO ... */
763 			csr &= ~MUSB_TXCSR_DMAMODE;
764 			musb_writew(epio, MUSB_TXCSR, csr);
765 			csr = musb_readw(epio, MUSB_TXCSR);
766 		} else {
767 			/* endpoint 0: just flush */
768 			musb_h_ep0_flush_fifo(hw_ep);
769 		}
770 
771 		/* target addr and (for multipoint) hub addr/port */
772 		if (musb->is_multipoint) {
773 			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
774 			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
775 			musb_write_txhubport(mbase, epnum, qh->h_port_reg);
776 /* FIXME if !epnum, do the same for RX ... */
777 		} else
778 			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
779 
780 		/* protocol/endpoint/interval/NAKlimit */
781 		if (epnum) {
782 			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
783 			if (musb->double_buffer_not_ok)
784 				musb_writew(epio, MUSB_TXMAXP,
785 						hw_ep->max_packet_sz_tx);
786 			else if (can_bulk_split(musb, qh->type))
787 				musb_writew(epio, MUSB_TXMAXP, packet_sz
788 					| ((hw_ep->max_packet_sz_tx /
789 						packet_sz) - 1) << 11);
790 			else
791 				musb_writew(epio, MUSB_TXMAXP,
792 						qh->maxpacket |
793 						((qh->hb_mult - 1) << 11));
794 			musb_writeb(epio, MUSB_TXINTERVAL, qh->intv_reg);
795 		} else {
796 			musb_writeb(epio, MUSB_NAKLIMIT0, qh->intv_reg);
797 			if (musb->is_multipoint)
798 				musb_writeb(epio, MUSB_TYPE0,
799 						qh->type_reg);
800 		}
801 
802 		if (can_bulk_split(musb, qh->type))
803 			load_count = min((u32) hw_ep->max_packet_sz_tx,
804 						len);
805 		else
806 			load_count = min((u32) packet_sz, len);
807 
808 		if (dma_channel && musb_tx_dma_program(dma_controller,
809 					hw_ep, qh, urb, offset, len))
810 			load_count = 0;
811 
812 		if (load_count) {
813 			/* PIO to load FIFO */
814 			qh->segsize = load_count;
815 			musb_write_fifo(hw_ep, load_count, buf);
816 		}
817 
818 		/* re-enable interrupt */
819 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
820 
821 	/* IN/receive */
822 	} else {
823 		u16	csr;
824 
825 		if (hw_ep->rx_reinit) {
826 			musb_rx_reinit(musb, qh, hw_ep);
827 
828 			/* init new state: toggle and NYET, maybe DMA later */
829 			if (usb_gettoggle(urb->dev, qh->epnum, 0))
830 				csr = MUSB_RXCSR_H_WR_DATATOGGLE
831 					| MUSB_RXCSR_H_DATATOGGLE;
832 			else
833 				csr = 0;
834 			if (qh->type == USB_ENDPOINT_XFER_INT)
835 				csr |= MUSB_RXCSR_DISNYET;
836 
837 		} else {
838 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
839 
840 			if (csr & (MUSB_RXCSR_RXPKTRDY
841 					| MUSB_RXCSR_DMAENAB
842 					| MUSB_RXCSR_H_REQPKT))
843 				ERR("broken !rx_reinit, ep%d csr %04x\n",
844 						hw_ep->epnum, csr);
845 
846 			/* scrub any stale state, leaving toggle alone */
847 			csr &= MUSB_RXCSR_DISNYET;
848 		}
849 
850 		/* kick things off */
851 
852 		if ((is_cppi_enabled() || tusb_dma_omap()) && dma_channel) {
853 			/* Candidate for DMA */
854 			dma_channel->actual_len = 0L;
855 			qh->segsize = len;
856 
857 			/* AUTOREQ is in a DMA register */
858 			musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
859 			csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
860 
861 			/*
862 			 * Unless caller treats short RX transfers as
863 			 * errors, we dare not queue multiple transfers.
864 			 */
865 			dma_ok = dma_controller->channel_program(dma_channel,
866 					packet_sz, !(urb->transfer_flags &
867 						     URB_SHORT_NOT_OK),
868 					urb->transfer_dma + offset,
869 					qh->segsize);
870 			if (!dma_ok) {
871 				dma_controller->channel_release(dma_channel);
872 				hw_ep->rx_channel = dma_channel = NULL;
873 			} else
874 				csr |= MUSB_RXCSR_DMAENAB;
875 		}
876 
877 		csr |= MUSB_RXCSR_H_REQPKT;
878 		dev_dbg(musb->controller, "RXCSR%d := %04x\n", epnum, csr);
879 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
880 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
881 	}
882 }
883 
884 
885 /*
886  * Service the default endpoint (ep0) as host.
887  * Return true until it's time to start the status stage.
888  */
889 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
890 {
891 	bool			 more = false;
892 	u8			*fifo_dest = NULL;
893 	u16			fifo_count = 0;
894 	struct musb_hw_ep	*hw_ep = musb->control_ep;
895 	struct musb_qh		*qh = hw_ep->in_qh;
896 	struct usb_ctrlrequest	*request;
897 
898 	switch (musb->ep0_stage) {
899 	case MUSB_EP0_IN:
900 		fifo_dest = urb->transfer_buffer + urb->actual_length;
901 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
902 				   urb->actual_length);
903 		if (fifo_count < len)
904 			urb->status = -EOVERFLOW;
905 
906 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
907 
908 		urb->actual_length += fifo_count;
909 		if (len < qh->maxpacket) {
910 			/* always terminate on short read; it's
911 			 * rarely reported as an error.
912 			 */
913 		} else if (urb->actual_length <
914 				urb->transfer_buffer_length)
915 			more = true;
916 		break;
917 	case MUSB_EP0_START:
918 		request = (struct usb_ctrlrequest *) urb->setup_packet;
919 
920 		if (!request->wLength) {
921 			dev_dbg(musb->controller, "start no-DATA\n");
922 			break;
923 		} else if (request->bRequestType & USB_DIR_IN) {
924 			dev_dbg(musb->controller, "start IN-DATA\n");
925 			musb->ep0_stage = MUSB_EP0_IN;
926 			more = true;
927 			break;
928 		} else {
929 			dev_dbg(musb->controller, "start OUT-DATA\n");
930 			musb->ep0_stage = MUSB_EP0_OUT;
931 			more = true;
932 		}
933 		/* FALLTHROUGH */
934 	case MUSB_EP0_OUT:
935 		fifo_count = min_t(size_t, qh->maxpacket,
936 				   urb->transfer_buffer_length -
937 				   urb->actual_length);
938 		if (fifo_count) {
939 			fifo_dest = (u8 *) (urb->transfer_buffer
940 					+ urb->actual_length);
941 			dev_dbg(musb->controller, "Sending %d byte%s to ep0 fifo %p\n",
942 					fifo_count,
943 					(fifo_count == 1) ? "" : "s",
944 					fifo_dest);
945 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
946 
947 			urb->actual_length += fifo_count;
948 			more = true;
949 		}
950 		break;
951 	default:
952 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
953 		break;
954 	}
955 
956 	return more;
957 }
958 
959 /*
960  * Handle default endpoint interrupt as host. Only called in IRQ time
961  * from musb_interrupt().
962  *
963  * called with controller irqlocked
964  */
965 irqreturn_t musb_h_ep0_irq(struct musb *musb)
966 {
967 	struct urb		*urb;
968 	u16			csr, len;
969 	int			status = 0;
970 	void __iomem		*mbase = musb->mregs;
971 	struct musb_hw_ep	*hw_ep = musb->control_ep;
972 	void __iomem		*epio = hw_ep->regs;
973 	struct musb_qh		*qh = hw_ep->in_qh;
974 	bool			complete = false;
975 	irqreturn_t		retval = IRQ_NONE;
976 
977 	/* ep0 only has one queue, "in" */
978 	urb = next_urb(qh);
979 
980 	musb_ep_select(mbase, 0);
981 	csr = musb_readw(epio, MUSB_CSR0);
982 	len = (csr & MUSB_CSR0_RXPKTRDY)
983 			? musb_readb(epio, MUSB_COUNT0)
984 			: 0;
985 
986 	dev_dbg(musb->controller, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
987 		csr, qh, len, urb, musb->ep0_stage);
988 
989 	/* if we just did status stage, we are done */
990 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
991 		retval = IRQ_HANDLED;
992 		complete = true;
993 	}
994 
995 	/* prepare status */
996 	if (csr & MUSB_CSR0_H_RXSTALL) {
997 		dev_dbg(musb->controller, "STALLING ENDPOINT\n");
998 		status = -EPIPE;
999 
1000 	} else if (csr & MUSB_CSR0_H_ERROR) {
1001 		dev_dbg(musb->controller, "no response, csr0 %04x\n", csr);
1002 		status = -EPROTO;
1003 
1004 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1005 		dev_dbg(musb->controller, "control NAK timeout\n");
1006 
1007 		/* NOTE:  this code path would be a good place to PAUSE a
1008 		 * control transfer, if another one is queued, so that
1009 		 * ep0 is more likely to stay busy.  That's already done
1010 		 * for bulk RX transfers.
1011 		 *
1012 		 * if (qh->ring.next != &musb->control), then
1013 		 * we have a candidate... NAKing is *NOT* an error
1014 		 */
1015 		musb_writew(epio, MUSB_CSR0, 0);
1016 		retval = IRQ_HANDLED;
1017 	}
1018 
1019 	if (status) {
1020 		dev_dbg(musb->controller, "aborting\n");
1021 		retval = IRQ_HANDLED;
1022 		if (urb)
1023 			urb->status = status;
1024 		complete = true;
1025 
1026 		/* use the proper sequence to abort the transfer */
1027 		if (csr & MUSB_CSR0_H_REQPKT) {
1028 			csr &= ~MUSB_CSR0_H_REQPKT;
1029 			musb_writew(epio, MUSB_CSR0, csr);
1030 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1031 			musb_writew(epio, MUSB_CSR0, csr);
1032 		} else {
1033 			musb_h_ep0_flush_fifo(hw_ep);
1034 		}
1035 
1036 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1037 
1038 		/* clear it */
1039 		musb_writew(epio, MUSB_CSR0, 0);
1040 	}
1041 
1042 	if (unlikely(!urb)) {
1043 		/* stop endpoint since we have no place for its data, this
1044 		 * SHOULD NEVER HAPPEN! */
1045 		ERR("no URB for end 0\n");
1046 
1047 		musb_h_ep0_flush_fifo(hw_ep);
1048 		goto done;
1049 	}
1050 
1051 	if (!complete) {
1052 		/* call common logic and prepare response */
1053 		if (musb_h_ep0_continue(musb, len, urb)) {
1054 			/* more packets required */
1055 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1056 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1057 		} else {
1058 			/* data transfer complete; perform status phase */
1059 			if (usb_pipeout(urb->pipe)
1060 					|| !urb->transfer_buffer_length)
1061 				csr = MUSB_CSR0_H_STATUSPKT
1062 					| MUSB_CSR0_H_REQPKT;
1063 			else
1064 				csr = MUSB_CSR0_H_STATUSPKT
1065 					| MUSB_CSR0_TXPKTRDY;
1066 
1067 			/* flag status stage */
1068 			musb->ep0_stage = MUSB_EP0_STATUS;
1069 
1070 			dev_dbg(musb->controller, "ep0 STATUS, csr %04x\n", csr);
1071 
1072 		}
1073 		musb_writew(epio, MUSB_CSR0, csr);
1074 		retval = IRQ_HANDLED;
1075 	} else
1076 		musb->ep0_stage = MUSB_EP0_IDLE;
1077 
1078 	/* call completion handler if done */
1079 	if (complete)
1080 		musb_advance_schedule(musb, urb, hw_ep, 1);
1081 done:
1082 	return retval;
1083 }
1084 
1085 
1086 #ifdef CONFIG_USB_INVENTRA_DMA
1087 
1088 /* Host side TX (OUT) using Mentor DMA works as follows:
1089 	submit_urb ->
1090 		- if queue was empty, Program Endpoint
1091 		- ... which starts DMA to fifo in mode 1 or 0
1092 
1093 	DMA Isr (transfer complete) -> TxAvail()
1094 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1095 					only in musb_cleanup_urb)
1096 		- TxPktRdy has to be set in mode 0 or for
1097 			short packets in mode 1.
1098 */
1099 
1100 #endif
1101 
1102 /* Service a Tx-Available or dma completion irq for the endpoint */
1103 void musb_host_tx(struct musb *musb, u8 epnum)
1104 {
1105 	int			pipe;
1106 	bool			done = false;
1107 	u16			tx_csr;
1108 	size_t			length = 0;
1109 	size_t			offset = 0;
1110 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1111 	void __iomem		*epio = hw_ep->regs;
1112 	struct musb_qh		*qh = hw_ep->out_qh;
1113 	struct urb		*urb = next_urb(qh);
1114 	u32			status = 0;
1115 	void __iomem		*mbase = musb->mregs;
1116 	struct dma_channel	*dma;
1117 	bool			transfer_pending = false;
1118 
1119 	musb_ep_select(mbase, epnum);
1120 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1121 
1122 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1123 	if (!urb) {
1124 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1125 		return;
1126 	}
1127 
1128 	pipe = urb->pipe;
1129 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1130 	dev_dbg(musb->controller, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
1131 			dma ? ", dma" : "");
1132 
1133 	/* check for errors */
1134 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1135 		/* dma was disabled, fifo flushed */
1136 		dev_dbg(musb->controller, "TX end %d stall\n", epnum);
1137 
1138 		/* stall; record URB status */
1139 		status = -EPIPE;
1140 
1141 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1142 		/* (NON-ISO) dma was disabled, fifo flushed */
1143 		dev_dbg(musb->controller, "TX 3strikes on ep=%d\n", epnum);
1144 
1145 		status = -ETIMEDOUT;
1146 
1147 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1148 		dev_dbg(musb->controller, "TX end=%d device not responding\n", epnum);
1149 
1150 		/* NOTE:  this code path would be a good place to PAUSE a
1151 		 * transfer, if there's some other (nonperiodic) tx urb
1152 		 * that could use this fifo.  (dma complicates it...)
1153 		 * That's already done for bulk RX transfers.
1154 		 *
1155 		 * if (bulk && qh->ring.next != &musb->out_bulk), then
1156 		 * we have a candidate... NAKing is *NOT* an error
1157 		 */
1158 		musb_ep_select(mbase, epnum);
1159 		musb_writew(epio, MUSB_TXCSR,
1160 				MUSB_TXCSR_H_WZC_BITS
1161 				| MUSB_TXCSR_TXPKTRDY);
1162 		return;
1163 	}
1164 
1165 	if (status) {
1166 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1167 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1168 			(void) musb->dma_controller->channel_abort(dma);
1169 		}
1170 
1171 		/* do the proper sequence to abort the transfer in the
1172 		 * usb core; the dma engine should already be stopped.
1173 		 */
1174 		musb_h_tx_flush_fifo(hw_ep);
1175 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1176 				| MUSB_TXCSR_DMAENAB
1177 				| MUSB_TXCSR_H_ERROR
1178 				| MUSB_TXCSR_H_RXSTALL
1179 				| MUSB_TXCSR_H_NAKTIMEOUT
1180 				);
1181 
1182 		musb_ep_select(mbase, epnum);
1183 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1184 		/* REVISIT may need to clear FLUSHFIFO ... */
1185 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1186 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1187 
1188 		done = true;
1189 	}
1190 
1191 	/* second cppi case */
1192 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1193 		dev_dbg(musb->controller, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1194 		return;
1195 	}
1196 
1197 	if (is_dma_capable() && dma && !status) {
1198 		/*
1199 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1200 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1201 		 * we can consider this transfer completed, lest we trash
1202 		 * its last packet when writing the next URB's data.  So we
1203 		 * switch back to mode 0 to get that interrupt; we'll come
1204 		 * back here once it happens.
1205 		 */
1206 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1207 			/*
1208 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1209 			 * clear them in a safe order.  That should be OK
1210 			 * once TXPKTRDY has been set (and I've never seen
1211 			 * it being 0 at this moment -- DMA interrupt latency
1212 			 * is significant) but if it hasn't been then we have
1213 			 * no choice but to stop being polite and ignore the
1214 			 * programmer's guide... :-)
1215 			 *
1216 			 * Note that we must write TXCSR with TXPKTRDY cleared
1217 			 * in order not to re-trigger the packet send (this bit
1218 			 * can't be cleared by CPU), and there's another caveat:
1219 			 * TXPKTRDY may be set shortly and then cleared in the
1220 			 * double-buffered FIFO mode, so we do an extra TXCSR
1221 			 * read for debouncing...
1222 			 */
1223 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1224 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1225 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1226 					    MUSB_TXCSR_TXPKTRDY);
1227 				musb_writew(epio, MUSB_TXCSR,
1228 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1229 			}
1230 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1231 				    MUSB_TXCSR_TXPKTRDY);
1232 			musb_writew(epio, MUSB_TXCSR,
1233 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1234 
1235 			/*
1236 			 * There is no guarantee that we'll get an interrupt
1237 			 * after clearing DMAMODE as we might have done this
1238 			 * too late (after TXPKTRDY was cleared by controller).
1239 			 * Re-read TXCSR as we have spoiled its previous value.
1240 			 */
1241 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1242 		}
1243 
1244 		/*
1245 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1246 		 * In any case, we must check the FIFO status here and bail out
1247 		 * only if the FIFO still has data -- that should prevent the
1248 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1249 		 * FIFO mode too...
1250 		 */
1251 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1252 			dev_dbg(musb->controller, "DMA complete but packet still in FIFO, "
1253 			    "CSR %04x\n", tx_csr);
1254 			return;
1255 		}
1256 	}
1257 
1258 	if (!status || dma || usb_pipeisoc(pipe)) {
1259 		if (dma)
1260 			length = dma->actual_len;
1261 		else
1262 			length = qh->segsize;
1263 		qh->offset += length;
1264 
1265 		if (usb_pipeisoc(pipe)) {
1266 #ifndef __UBOOT__
1267 			struct usb_iso_packet_descriptor	*d;
1268 
1269 			d = urb->iso_frame_desc + qh->iso_idx;
1270 			d->actual_length = length;
1271 			d->status = status;
1272 			if (++qh->iso_idx >= urb->number_of_packets) {
1273 				done = true;
1274 			} else {
1275 				d++;
1276 				offset = d->offset;
1277 				length = d->length;
1278 			}
1279 #endif
1280 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1281 			done = true;
1282 		} else {
1283 			/* see if we need to send more data, or ZLP */
1284 			if (qh->segsize < qh->maxpacket)
1285 				done = true;
1286 			else if (qh->offset == urb->transfer_buffer_length
1287 					&& !(urb->transfer_flags
1288 						& URB_ZERO_PACKET))
1289 				done = true;
1290 			if (!done) {
1291 				offset = qh->offset;
1292 				length = urb->transfer_buffer_length - offset;
1293 				transfer_pending = true;
1294 			}
1295 		}
1296 	}
1297 
1298 	/* urb->status != -EINPROGRESS means request has been faulted,
1299 	 * so we must abort this transfer after cleanup
1300 	 */
1301 	if (urb->status != -EINPROGRESS) {
1302 		done = true;
1303 		if (status == 0)
1304 			status = urb->status;
1305 	}
1306 
1307 	if (done) {
1308 		/* set status */
1309 		urb->status = status;
1310 		urb->actual_length = qh->offset;
1311 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1312 		return;
1313 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1314 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1315 				offset, length)) {
1316 			if (is_cppi_enabled() || tusb_dma_omap())
1317 				musb_h_tx_dma_start(hw_ep);
1318 			return;
1319 		}
1320 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1321 		dev_dbg(musb->controller, "not complete, but DMA enabled?\n");
1322 		return;
1323 	}
1324 
1325 	/*
1326 	 * PIO: start next packet in this URB.
1327 	 *
1328 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1329 	 * (and presumably, FIFO is not half-full) we should write *two*
1330 	 * packets before updating TXCSR; other docs disagree...
1331 	 */
1332 	if (length > qh->maxpacket)
1333 		length = qh->maxpacket;
1334 	/* Unmap the buffer so that CPU can use it */
1335 	usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1336 	musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1337 	qh->segsize = length;
1338 
1339 	musb_ep_select(mbase, epnum);
1340 	musb_writew(epio, MUSB_TXCSR,
1341 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1342 }
1343 
1344 
1345 #ifdef CONFIG_USB_INVENTRA_DMA
1346 
1347 /* Host side RX (IN) using Mentor DMA works as follows:
1348 	submit_urb ->
1349 		- if queue was empty, ProgramEndpoint
1350 		- first IN token is sent out (by setting ReqPkt)
1351 	LinuxIsr -> RxReady()
1352 	/\	=> first packet is received
1353 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1354 	|		-> DMA Isr (transfer complete) -> RxReady()
1355 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1356 	|		    - if urb not complete, send next IN token (ReqPkt)
1357 	|			   |		else complete urb.
1358 	|			   |
1359 	---------------------------
1360  *
1361  * Nuances of mode 1:
1362  *	For short packets, no ack (+RxPktRdy) is sent automatically
1363  *	(even if AutoClear is ON)
1364  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1365  *	automatically => major problem, as collecting the next packet becomes
1366  *	difficult. Hence mode 1 is not used.
1367  *
1368  * REVISIT
1369  *	All we care about at this driver level is that
1370  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1371  *       (b) termination conditions are: short RX, or buffer full;
1372  *       (c) fault modes include
1373  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1374  *             (and that endpoint's dma queue stops immediately)
1375  *           - overflow (full, PLUS more bytes in the terminal packet)
1376  *
1377  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1378  *	thus be a great candidate for using mode 1 ... for all but the
1379  *	last packet of one URB's transfer.
1380  */
1381 
1382 #endif
1383 
1384 /* Schedule next QH from musb->in_bulk and move the current qh to
1385  * the end; avoids starvation for other endpoints.
1386  */
1387 static void musb_bulk_rx_nak_timeout(struct musb *musb, struct musb_hw_ep *ep)
1388 {
1389 	struct dma_channel	*dma;
1390 	struct urb		*urb;
1391 	void __iomem		*mbase = musb->mregs;
1392 	void __iomem		*epio = ep->regs;
1393 	struct musb_qh		*cur_qh, *next_qh;
1394 	u16			rx_csr;
1395 
1396 	musb_ep_select(mbase, ep->epnum);
1397 	dma = is_dma_capable() ? ep->rx_channel : NULL;
1398 
1399 	/* clear nak timeout bit */
1400 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1401 	rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1402 	rx_csr &= ~MUSB_RXCSR_DATAERROR;
1403 	musb_writew(epio, MUSB_RXCSR, rx_csr);
1404 
1405 	cur_qh = first_qh(&musb->in_bulk);
1406 	if (cur_qh) {
1407 		urb = next_urb(cur_qh);
1408 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1409 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1410 			musb->dma_controller->channel_abort(dma);
1411 			urb->actual_length += dma->actual_len;
1412 			dma->actual_len = 0L;
1413 		}
1414 		musb_save_toggle(cur_qh, 1, urb);
1415 
1416 		/* move cur_qh to end of queue */
1417 		list_move_tail(&cur_qh->ring, &musb->in_bulk);
1418 
1419 		/* get the next qh from musb->in_bulk */
1420 		next_qh = first_qh(&musb->in_bulk);
1421 
1422 		/* set rx_reinit and schedule the next qh */
1423 		ep->rx_reinit = 1;
1424 		musb_start_urb(musb, 1, next_qh);
1425 	}
1426 }
1427 
1428 /*
1429  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1430  * and high-bandwidth IN transfer cases.
1431  */
1432 void musb_host_rx(struct musb *musb, u8 epnum)
1433 {
1434 	struct urb		*urb;
1435 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1436 	void __iomem		*epio = hw_ep->regs;
1437 	struct musb_qh		*qh = hw_ep->in_qh;
1438 	size_t			xfer_len;
1439 	void __iomem		*mbase = musb->mregs;
1440 	int			pipe;
1441 	u16			rx_csr, val;
1442 	bool			iso_err = false;
1443 	bool			done = false;
1444 	u32			status;
1445 	struct dma_channel	*dma;
1446 
1447 	musb_ep_select(mbase, epnum);
1448 
1449 	urb = next_urb(qh);
1450 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1451 	status = 0;
1452 	xfer_len = 0;
1453 
1454 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1455 	val = rx_csr;
1456 
1457 	if (unlikely(!urb)) {
1458 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1459 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1460 		 * with fifo full.  (Only with DMA??)
1461 		 */
1462 		dev_dbg(musb->controller, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
1463 			musb_readw(epio, MUSB_RXCOUNT));
1464 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1465 		return;
1466 	}
1467 
1468 	pipe = urb->pipe;
1469 
1470 	dev_dbg(musb->controller, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
1471 		epnum, rx_csr, urb->actual_length,
1472 		dma ? dma->actual_len : 0);
1473 
1474 	/* check for errors, concurrent stall & unlink is not really
1475 	 * handled yet! */
1476 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1477 		dev_dbg(musb->controller, "RX end %d STALL\n", epnum);
1478 
1479 		/* stall; record URB status */
1480 		status = -EPIPE;
1481 
1482 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1483 		dev_dbg(musb->controller, "end %d RX proto error\n", epnum);
1484 
1485 		status = -EPROTO;
1486 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1487 
1488 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1489 
1490 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1491 			dev_dbg(musb->controller, "RX end %d NAK timeout\n", epnum);
1492 
1493 			/* NOTE: NAKing is *NOT* an error, so we want to
1494 			 * continue.  Except ... if there's a request for
1495 			 * another QH, use that instead of starving it.
1496 			 *
1497 			 * Devices like Ethernet and serial adapters keep
1498 			 * reads posted at all times, which will starve
1499 			 * other devices without this logic.
1500 			 */
1501 			if (usb_pipebulk(urb->pipe)
1502 					&& qh->mux == 1
1503 					&& !list_is_singular(&musb->in_bulk)) {
1504 				musb_bulk_rx_nak_timeout(musb, hw_ep);
1505 				return;
1506 			}
1507 			musb_ep_select(mbase, epnum);
1508 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1509 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1510 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1511 
1512 			goto finish;
1513 		} else {
1514 			dev_dbg(musb->controller, "RX end %d ISO data error\n", epnum);
1515 			/* packet error reported later */
1516 			iso_err = true;
1517 		}
1518 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1519 		dev_dbg(musb->controller, "end %d high bandwidth incomplete ISO packet RX\n",
1520 				epnum);
1521 		status = -EPROTO;
1522 	}
1523 
1524 	/* faults abort the transfer */
1525 	if (status) {
1526 		/* clean up dma and collect transfer count */
1527 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1528 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1529 			(void) musb->dma_controller->channel_abort(dma);
1530 			xfer_len = dma->actual_len;
1531 		}
1532 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1533 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1534 		done = true;
1535 		goto finish;
1536 	}
1537 
1538 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1539 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1540 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1541 		goto finish;
1542 	}
1543 
1544 	/* thorough shutdown for now ... given more precise fault handling
1545 	 * and better queueing support, we might keep a DMA pipeline going
1546 	 * while processing this irq for earlier completions.
1547 	 */
1548 
1549 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1550 
1551 #ifndef CONFIG_USB_INVENTRA_DMA
1552 	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
1553 		/* REVISIT this happened for a while on some short reads...
1554 		 * the cleanup still needs investigation... looks bad...
1555 		 * and also duplicates dma cleanup code above ... plus,
1556 		 * shouldn't this be the "half full" double buffer case?
1557 		 */
1558 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1559 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1560 			(void) musb->dma_controller->channel_abort(dma);
1561 			xfer_len = dma->actual_len;
1562 			done = true;
1563 		}
1564 
1565 		dev_dbg(musb->controller, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
1566 				xfer_len, dma ? ", dma" : "");
1567 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1568 
1569 		musb_ep_select(mbase, epnum);
1570 		musb_writew(epio, MUSB_RXCSR,
1571 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1572 	}
1573 #endif
1574 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1575 		xfer_len = dma->actual_len;
1576 
1577 		val &= ~(MUSB_RXCSR_DMAENAB
1578 			| MUSB_RXCSR_H_AUTOREQ
1579 			| MUSB_RXCSR_AUTOCLEAR
1580 			| MUSB_RXCSR_RXPKTRDY);
1581 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1582 
1583 #ifdef CONFIG_USB_INVENTRA_DMA
1584 		if (usb_pipeisoc(pipe)) {
1585 			struct usb_iso_packet_descriptor *d;
1586 
1587 			d = urb->iso_frame_desc + qh->iso_idx;
1588 			d->actual_length = xfer_len;
1589 
1590 			/* even if there was an error, we did the dma
1591 			 * for iso_frame_desc->length
1592 			 */
1593 			if (d->status != -EILSEQ && d->status != -EOVERFLOW)
1594 				d->status = 0;
1595 
1596 			if (++qh->iso_idx >= urb->number_of_packets)
1597 				done = true;
1598 			else
1599 				done = false;
1600 
1601 		} else  {
1602 		/* done if urb buffer is full or short packet is recd */
1603 		done = (urb->actual_length + xfer_len >=
1604 				urb->transfer_buffer_length
1605 			|| dma->actual_len < qh->maxpacket);
1606 		}
1607 
1608 		/* send IN token for next packet, without AUTOREQ */
1609 		if (!done) {
1610 			val |= MUSB_RXCSR_H_REQPKT;
1611 			musb_writew(epio, MUSB_RXCSR,
1612 				MUSB_RXCSR_H_WZC_BITS | val);
1613 		}
1614 
1615 		dev_dbg(musb->controller, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
1616 			done ? "off" : "reset",
1617 			musb_readw(epio, MUSB_RXCSR),
1618 			musb_readw(epio, MUSB_RXCOUNT));
1619 #else
1620 		done = true;
1621 #endif
1622 	} else if (urb->status == -EINPROGRESS) {
1623 		/* if no errors, be sure a packet is ready for unloading */
1624 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1625 			status = -EPROTO;
1626 			ERR("Rx interrupt with no errors or packet!\n");
1627 
1628 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1629 
1630 /* SCRUB (RX) */
1631 			/* do the proper sequence to abort the transfer */
1632 			musb_ep_select(mbase, epnum);
1633 			val &= ~MUSB_RXCSR_H_REQPKT;
1634 			musb_writew(epio, MUSB_RXCSR, val);
1635 			goto finish;
1636 		}
1637 
1638 		/* we are expecting IN packets */
1639 #ifdef CONFIG_USB_INVENTRA_DMA
1640 		if (dma) {
1641 			struct dma_controller	*c;
1642 			u16			rx_count;
1643 			int			ret, length;
1644 			dma_addr_t		buf;
1645 
1646 			rx_count = musb_readw(epio, MUSB_RXCOUNT);
1647 
1648 			dev_dbg(musb->controller, "RX%d count %d, buffer 0x%x len %d/%d\n",
1649 					epnum, rx_count,
1650 					urb->transfer_dma
1651 						+ urb->actual_length,
1652 					qh->offset,
1653 					urb->transfer_buffer_length);
1654 
1655 			c = musb->dma_controller;
1656 
1657 			if (usb_pipeisoc(pipe)) {
1658 				int d_status = 0;
1659 				struct usb_iso_packet_descriptor *d;
1660 
1661 				d = urb->iso_frame_desc + qh->iso_idx;
1662 
1663 				if (iso_err) {
1664 					d_status = -EILSEQ;
1665 					urb->error_count++;
1666 				}
1667 				if (rx_count > d->length) {
1668 					if (d_status == 0) {
1669 						d_status = -EOVERFLOW;
1670 						urb->error_count++;
1671 					}
1672 					dev_dbg(musb->controller, "** OVERFLOW %d into %d\n",\
1673 					    rx_count, d->length);
1674 
1675 					length = d->length;
1676 				} else
1677 					length = rx_count;
1678 				d->status = d_status;
1679 				buf = urb->transfer_dma + d->offset;
1680 			} else {
1681 				length = rx_count;
1682 				buf = urb->transfer_dma +
1683 						urb->actual_length;
1684 			}
1685 
1686 			dma->desired_mode = 0;
1687 #ifdef USE_MODE1
1688 			/* because of the issue below, mode 1 will
1689 			 * only rarely behave with correct semantics.
1690 			 */
1691 			if ((urb->transfer_flags &
1692 						URB_SHORT_NOT_OK)
1693 				&& (urb->transfer_buffer_length -
1694 						urb->actual_length)
1695 					> qh->maxpacket)
1696 				dma->desired_mode = 1;
1697 			if (rx_count < hw_ep->max_packet_sz_rx) {
1698 				length = rx_count;
1699 				dma->desired_mode = 0;
1700 			} else {
1701 				length = urb->transfer_buffer_length;
1702 			}
1703 #endif
1704 
1705 /* Disadvantage of using mode 1:
1706  *	It's basically usable only for mass storage class; essentially all
1707  *	other protocols also terminate transfers on short packets.
1708  *
1709  * Details:
1710  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1711  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1712  *	to use the extra IN token to grab the last packet using mode 0, then
1713  *	the problem is that you cannot be sure when the device will send the
1714  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1715  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1716  *	transfer, while sometimes it is recd just a little late so that if you
1717  *	try to configure for mode 0 soon after the mode 1 transfer is
1718  *	completed, you will find rxcount 0. Okay, so you might think why not
1719  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1720  */
1721 
1722 			val = musb_readw(epio, MUSB_RXCSR);
1723 			val &= ~MUSB_RXCSR_H_REQPKT;
1724 
1725 			if (dma->desired_mode == 0)
1726 				val &= ~MUSB_RXCSR_H_AUTOREQ;
1727 			else
1728 				val |= MUSB_RXCSR_H_AUTOREQ;
1729 			val |= MUSB_RXCSR_DMAENAB;
1730 
1731 			/* autoclear shouldn't be set in high bandwidth */
1732 			if (qh->hb_mult == 1)
1733 				val |= MUSB_RXCSR_AUTOCLEAR;
1734 
1735 			musb_writew(epio, MUSB_RXCSR,
1736 				MUSB_RXCSR_H_WZC_BITS | val);
1737 
1738 			/* REVISIT if when actual_length != 0,
1739 			 * transfer_buffer_length needs to be
1740 			 * adjusted first...
1741 			 */
1742 			ret = c->channel_program(
1743 				dma, qh->maxpacket,
1744 				dma->desired_mode, buf, length);
1745 
1746 			if (!ret) {
1747 				c->channel_release(dma);
1748 				hw_ep->rx_channel = NULL;
1749 				dma = NULL;
1750 				val = musb_readw(epio, MUSB_RXCSR);
1751 				val &= ~(MUSB_RXCSR_DMAENAB
1752 					| MUSB_RXCSR_H_AUTOREQ
1753 					| MUSB_RXCSR_AUTOCLEAR);
1754 				musb_writew(epio, MUSB_RXCSR, val);
1755 			}
1756 		}
1757 #endif	/* Mentor DMA */
1758 
1759 		if (!dma) {
1760 			/* Unmap the buffer so that CPU can use it */
1761 			usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1762 			done = musb_host_packet_rx(musb, urb,
1763 					epnum, iso_err);
1764 			dev_dbg(musb->controller, "read %spacket\n", done ? "last " : "");
1765 		}
1766 	}
1767 
1768 finish:
1769 	urb->actual_length += xfer_len;
1770 	qh->offset += xfer_len;
1771 	if (done) {
1772 		if (urb->status == -EINPROGRESS)
1773 			urb->status = status;
1774 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1775 	}
1776 }
1777 
1778 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1779  * the software schedule associates multiple such nodes with a given
1780  * host side hardware endpoint + direction; scheduling may activate
1781  * that hardware endpoint.
1782  */
1783 static int musb_schedule(
1784 	struct musb		*musb,
1785 	struct musb_qh		*qh,
1786 	int			is_in)
1787 {
1788 	int			idle;
1789 	int			best_diff;
1790 	int			best_end, epnum;
1791 	struct musb_hw_ep	*hw_ep = NULL;
1792 	struct list_head	*head = NULL;
1793 	u8			toggle;
1794 	u8			txtype;
1795 	struct urb		*urb = next_urb(qh);
1796 
1797 	/* use fixed hardware for control and bulk */
1798 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1799 		head = &musb->control;
1800 		hw_ep = musb->control_ep;
1801 		goto success;
1802 	}
1803 
1804 	/* else, periodic transfers get muxed to other endpoints */
1805 
1806 	/*
1807 	 * We know this qh hasn't been scheduled, so all we need to do
1808 	 * is choose which hardware endpoint to put it on ...
1809 	 *
1810 	 * REVISIT what we really want here is a regular schedule tree
1811 	 * like e.g. OHCI uses.
1812 	 */
1813 	best_diff = 4096;
1814 	best_end = -1;
1815 
1816 	for (epnum = 1, hw_ep = musb->endpoints + 1;
1817 			epnum < musb->nr_endpoints;
1818 			epnum++, hw_ep++) {
1819 		int	diff;
1820 
1821 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
1822 			continue;
1823 
1824 		if (hw_ep == musb->bulk_ep)
1825 			continue;
1826 
1827 		if (is_in)
1828 			diff = hw_ep->max_packet_sz_rx;
1829 		else
1830 			diff = hw_ep->max_packet_sz_tx;
1831 		diff -= (qh->maxpacket * qh->hb_mult);
1832 
1833 		if (diff >= 0 && best_diff > diff) {
1834 
1835 			/*
1836 			 * Mentor controller has a bug in that if we schedule
1837 			 * a BULK Tx transfer on an endpoint that had earlier
1838 			 * handled ISOC then the BULK transfer has to start on
1839 			 * a zero toggle.  If the BULK transfer starts on a 1
1840 			 * toggle then this transfer will fail as the mentor
1841 			 * controller starts the Bulk transfer on a 0 toggle
1842 			 * irrespective of the programming of the toggle bits
1843 			 * in the TXCSR register.  Check for this condition
1844 			 * while allocating the EP for a Tx Bulk transfer.  If
1845 			 * so skip this EP.
1846 			 */
1847 			hw_ep = musb->endpoints + epnum;
1848 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
1849 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
1850 					>> 4) & 0x3;
1851 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
1852 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
1853 				continue;
1854 
1855 			best_diff = diff;
1856 			best_end = epnum;
1857 		}
1858 	}
1859 	/* use bulk reserved ep1 if no other ep is free */
1860 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
1861 		hw_ep = musb->bulk_ep;
1862 		if (is_in)
1863 			head = &musb->in_bulk;
1864 		else
1865 			head = &musb->out_bulk;
1866 
1867 		/* Enable bulk RX NAK timeout scheme when bulk requests are
1868 		 * multiplexed.  This scheme doen't work in high speed to full
1869 		 * speed scenario as NAK interrupts are not coming from a
1870 		 * full speed device connected to a high speed device.
1871 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
1872 		 * 4 (8 frame or 8ms) for FS device.
1873 		 */
1874 		if (is_in && qh->dev)
1875 			qh->intv_reg =
1876 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
1877 		goto success;
1878 	} else if (best_end < 0) {
1879 		return -ENOSPC;
1880 	}
1881 
1882 	idle = 1;
1883 	qh->mux = 0;
1884 	hw_ep = musb->endpoints + best_end;
1885 	dev_dbg(musb->controller, "qh %p periodic slot %d\n", qh, best_end);
1886 success:
1887 	if (head) {
1888 		idle = list_empty(head);
1889 		list_add_tail(&qh->ring, head);
1890 		qh->mux = 1;
1891 	}
1892 	qh->hw_ep = hw_ep;
1893 	qh->hep->hcpriv = qh;
1894 	if (idle)
1895 		musb_start_urb(musb, is_in, qh);
1896 	return 0;
1897 }
1898 
1899 #ifdef __UBOOT__
1900 /* check if transaction translator is needed for device */
1901 static int tt_needed(struct musb *musb, struct usb_device *dev)
1902 {
1903 	if ((musb_readb(musb->mregs, MUSB_POWER) & MUSB_POWER_HSMODE) &&
1904 			(dev->speed < USB_SPEED_HIGH))
1905 		return 1;
1906 	return 0;
1907 }
1908 #endif
1909 
1910 #ifndef __UBOOT__
1911 static int musb_urb_enqueue(
1912 #else
1913 int musb_urb_enqueue(
1914 #endif
1915 	struct usb_hcd			*hcd,
1916 	struct urb			*urb,
1917 	gfp_t				mem_flags)
1918 {
1919 	unsigned long			flags;
1920 	struct musb			*musb = hcd_to_musb(hcd);
1921 	struct usb_host_endpoint	*hep = urb->ep;
1922 	struct musb_qh			*qh;
1923 	struct usb_endpoint_descriptor	*epd = &hep->desc;
1924 	int				ret;
1925 	unsigned			type_reg;
1926 	unsigned			interval;
1927 
1928 	/* host role must be active */
1929 	if (!is_host_active(musb) || !musb->is_active)
1930 		return -ENODEV;
1931 
1932 	spin_lock_irqsave(&musb->lock, flags);
1933 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
1934 	qh = ret ? NULL : hep->hcpriv;
1935 	if (qh)
1936 		urb->hcpriv = qh;
1937 	spin_unlock_irqrestore(&musb->lock, flags);
1938 
1939 	/* DMA mapping was already done, if needed, and this urb is on
1940 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
1941 	 * scheduled onto a live qh.
1942 	 *
1943 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
1944 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
1945 	 * except for the first urb queued after a config change.
1946 	 */
1947 	if (qh || ret)
1948 		return ret;
1949 
1950 	/* Allocate and initialize qh, minimizing the work done each time
1951 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
1952 	 *
1953 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
1954 	 * for bugs in other kernel code to break this driver...
1955 	 */
1956 	qh = kzalloc(sizeof *qh, mem_flags);
1957 	if (!qh) {
1958 		spin_lock_irqsave(&musb->lock, flags);
1959 		usb_hcd_unlink_urb_from_ep(hcd, urb);
1960 		spin_unlock_irqrestore(&musb->lock, flags);
1961 		return -ENOMEM;
1962 	}
1963 
1964 	qh->hep = hep;
1965 	qh->dev = urb->dev;
1966 	INIT_LIST_HEAD(&qh->ring);
1967 	qh->is_ready = 1;
1968 
1969 	qh->maxpacket = usb_endpoint_maxp(epd);
1970 	qh->type = usb_endpoint_type(epd);
1971 
1972 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
1973 	 * Some musb cores don't support high bandwidth ISO transfers; and
1974 	 * we don't (yet!) support high bandwidth interrupt transfers.
1975 	 */
1976 	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
1977 	if (qh->hb_mult > 1) {
1978 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
1979 
1980 		if (ok)
1981 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
1982 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
1983 		if (!ok) {
1984 			ret = -EMSGSIZE;
1985 			goto done;
1986 		}
1987 		qh->maxpacket &= 0x7ff;
1988 	}
1989 
1990 	qh->epnum = usb_endpoint_num(epd);
1991 
1992 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
1993 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
1994 
1995 	/* precompute rxtype/txtype/type0 register */
1996 	type_reg = (qh->type << 4) | qh->epnum;
1997 	switch (urb->dev->speed) {
1998 	case USB_SPEED_LOW:
1999 		type_reg |= 0xc0;
2000 		break;
2001 	case USB_SPEED_FULL:
2002 		type_reg |= 0x80;
2003 		break;
2004 	default:
2005 		type_reg |= 0x40;
2006 	}
2007 	qh->type_reg = type_reg;
2008 
2009 	/* Precompute RXINTERVAL/TXINTERVAL register */
2010 	switch (qh->type) {
2011 	case USB_ENDPOINT_XFER_INT:
2012 		/*
2013 		 * Full/low speeds use the  linear encoding,
2014 		 * high speed uses the logarithmic encoding.
2015 		 */
2016 		if (urb->dev->speed <= USB_SPEED_FULL) {
2017 			interval = max_t(u8, epd->bInterval, 1);
2018 			break;
2019 		}
2020 		/* FALLTHROUGH */
2021 	case USB_ENDPOINT_XFER_ISOC:
2022 		/* ISO always uses logarithmic encoding */
2023 		interval = min_t(u8, epd->bInterval, 16);
2024 		break;
2025 	default:
2026 		/* REVISIT we actually want to use NAK limits, hinting to the
2027 		 * transfer scheduling logic to try some other qh, e.g. try
2028 		 * for 2 msec first:
2029 		 *
2030 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2031 		 *
2032 		 * The downside of disabling this is that transfer scheduling
2033 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2034 		 * peripheral could make that hurt.  That's perfectly normal
2035 		 * for reads from network or serial adapters ... so we have
2036 		 * partial NAKlimit support for bulk RX.
2037 		 *
2038 		 * The upside of disabling it is simpler transfer scheduling.
2039 		 */
2040 		interval = 0;
2041 	}
2042 	qh->intv_reg = interval;
2043 
2044 	/* precompute addressing for external hub/tt ports */
2045 	if (musb->is_multipoint) {
2046 #ifndef __UBOOT__
2047 		struct usb_device	*parent = urb->dev->parent;
2048 #else
2049 		struct usb_device	*parent = usb_dev_get_parent(urb->dev);
2050 #endif
2051 
2052 #ifndef __UBOOT__
2053 		if (parent != hcd->self.root_hub) {
2054 #else
2055 		if (parent) {
2056 #endif
2057 			qh->h_addr_reg = (u8) parent->devnum;
2058 
2059 #ifndef __UBOOT__
2060 			/* set up tt info if needed */
2061 			if (urb->dev->tt) {
2062 				qh->h_port_reg = (u8) urb->dev->ttport;
2063 				if (urb->dev->tt->hub)
2064 					qh->h_addr_reg =
2065 						(u8) urb->dev->tt->hub->devnum;
2066 				if (urb->dev->tt->multi)
2067 					qh->h_addr_reg |= 0x80;
2068 			}
2069 #else
2070 			if (tt_needed(musb, urb->dev)) {
2071 				uint8_t portnr = 0;
2072 				uint8_t hubaddr = 0;
2073 				usb_find_usb2_hub_address_port(urb->dev,
2074 							       &hubaddr,
2075 							       &portnr);
2076 				qh->h_addr_reg = hubaddr;
2077 				qh->h_port_reg = portnr;
2078 			}
2079 #endif
2080 		}
2081 	}
2082 
2083 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2084 	 * until we get real dma queues (with an entry for each urb/buffer),
2085 	 * we only have work to do in the former case.
2086 	 */
2087 	spin_lock_irqsave(&musb->lock, flags);
2088 	if (hep->hcpriv) {
2089 		/* some concurrent activity submitted another urb to hep...
2090 		 * odd, rare, error prone, but legal.
2091 		 */
2092 		kfree(qh);
2093 		qh = NULL;
2094 		ret = 0;
2095 	} else
2096 		ret = musb_schedule(musb, qh,
2097 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2098 
2099 	if (ret == 0) {
2100 		urb->hcpriv = qh;
2101 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2102 		 * musb_start_urb(), but otherwise only konicawc cares ...
2103 		 */
2104 	}
2105 	spin_unlock_irqrestore(&musb->lock, flags);
2106 
2107 done:
2108 	if (ret != 0) {
2109 		spin_lock_irqsave(&musb->lock, flags);
2110 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2111 		spin_unlock_irqrestore(&musb->lock, flags);
2112 		kfree(qh);
2113 	}
2114 	return ret;
2115 }
2116 
2117 /*
2118  * abort a transfer that's at the head of a hardware queue.
2119  * called with controller locked, irqs blocked
2120  * that hardware queue advances to the next transfer, unless prevented
2121  */
2122 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2123 {
2124 	struct musb_hw_ep	*ep = qh->hw_ep;
2125 	struct musb		*musb = ep->musb;
2126 	void __iomem		*epio = ep->regs;
2127 	unsigned		hw_end = ep->epnum;
2128 	void __iomem		*regs = ep->musb->mregs;
2129 	int			is_in = usb_pipein(urb->pipe);
2130 	int			status = 0;
2131 	u16			csr;
2132 
2133 	musb_ep_select(regs, hw_end);
2134 
2135 	if (is_dma_capable()) {
2136 		struct dma_channel	*dma;
2137 
2138 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2139 		if (dma) {
2140 			status = ep->musb->dma_controller->channel_abort(dma);
2141 			dev_dbg(musb->controller,
2142 				"abort %cX%d DMA for urb %p --> %d\n",
2143 				is_in ? 'R' : 'T', ep->epnum,
2144 				urb, status);
2145 			urb->actual_length += dma->actual_len;
2146 		}
2147 	}
2148 
2149 	/* turn off DMA requests, discard state, stop polling ... */
2150 	if (ep->epnum && is_in) {
2151 		/* giveback saves bulk toggle */
2152 		csr = musb_h_flush_rxfifo(ep, 0);
2153 
2154 		/* REVISIT we still get an irq; should likely clear the
2155 		 * endpoint's irq status here to avoid bogus irqs.
2156 		 * clearing that status is platform-specific...
2157 		 */
2158 	} else if (ep->epnum) {
2159 		musb_h_tx_flush_fifo(ep);
2160 		csr = musb_readw(epio, MUSB_TXCSR);
2161 		csr &= ~(MUSB_TXCSR_AUTOSET
2162 			| MUSB_TXCSR_DMAENAB
2163 			| MUSB_TXCSR_H_RXSTALL
2164 			| MUSB_TXCSR_H_NAKTIMEOUT
2165 			| MUSB_TXCSR_H_ERROR
2166 			| MUSB_TXCSR_TXPKTRDY);
2167 		musb_writew(epio, MUSB_TXCSR, csr);
2168 		/* REVISIT may need to clear FLUSHFIFO ... */
2169 		musb_writew(epio, MUSB_TXCSR, csr);
2170 		/* flush cpu writebuffer */
2171 		csr = musb_readw(epio, MUSB_TXCSR);
2172 	} else  {
2173 		musb_h_ep0_flush_fifo(ep);
2174 	}
2175 	if (status == 0)
2176 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2177 	return status;
2178 }
2179 
2180 #ifndef __UBOOT__
2181 static int musb_urb_dequeue(
2182 #else
2183 int musb_urb_dequeue(
2184 #endif
2185 	struct usb_hcd *hcd,
2186 	struct urb *urb,
2187 	int status)
2188 {
2189 	struct musb		*musb = hcd_to_musb(hcd);
2190 	struct musb_qh		*qh;
2191 	unsigned long		flags;
2192 	int			is_in  = usb_pipein(urb->pipe);
2193 	int			ret;
2194 
2195 	dev_dbg(musb->controller, "urb=%p, dev%d ep%d%s\n", urb,
2196 			usb_pipedevice(urb->pipe),
2197 			usb_pipeendpoint(urb->pipe),
2198 			is_in ? "in" : "out");
2199 
2200 	spin_lock_irqsave(&musb->lock, flags);
2201 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2202 	if (ret)
2203 		goto done;
2204 
2205 	qh = urb->hcpriv;
2206 	if (!qh)
2207 		goto done;
2208 
2209 	/*
2210 	 * Any URB not actively programmed into endpoint hardware can be
2211 	 * immediately given back; that's any URB not at the head of an
2212 	 * endpoint queue, unless someday we get real DMA queues.  And even
2213 	 * if it's at the head, it might not be known to the hardware...
2214 	 *
2215 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2216 	 * has already been updated.  This is a synchronous abort; it'd be
2217 	 * OK to hold off until after some IRQ, though.
2218 	 *
2219 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2220 	 */
2221 	if (!qh->is_ready
2222 			|| urb->urb_list.prev != &qh->hep->urb_list
2223 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2224 		int	ready = qh->is_ready;
2225 
2226 		qh->is_ready = 0;
2227 		musb_giveback(musb, urb, 0);
2228 		qh->is_ready = ready;
2229 
2230 		/* If nothing else (usually musb_giveback) is using it
2231 		 * and its URB list has emptied, recycle this qh.
2232 		 */
2233 		if (ready && list_empty(&qh->hep->urb_list)) {
2234 			qh->hep->hcpriv = NULL;
2235 			list_del(&qh->ring);
2236 			kfree(qh);
2237 		}
2238 	} else
2239 		ret = musb_cleanup_urb(urb, qh);
2240 done:
2241 	spin_unlock_irqrestore(&musb->lock, flags);
2242 	return ret;
2243 }
2244 
2245 #ifndef __UBOOT__
2246 /* disable an endpoint */
2247 static void
2248 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2249 {
2250 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2251 	unsigned long		flags;
2252 	struct musb		*musb = hcd_to_musb(hcd);
2253 	struct musb_qh		*qh;
2254 	struct urb		*urb;
2255 
2256 	spin_lock_irqsave(&musb->lock, flags);
2257 
2258 	qh = hep->hcpriv;
2259 	if (qh == NULL)
2260 		goto exit;
2261 
2262 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2263 
2264 	/* Kick the first URB off the hardware, if needed */
2265 	qh->is_ready = 0;
2266 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2267 		urb = next_urb(qh);
2268 
2269 		/* make software (then hardware) stop ASAP */
2270 		if (!urb->unlinked)
2271 			urb->status = -ESHUTDOWN;
2272 
2273 		/* cleanup */
2274 		musb_cleanup_urb(urb, qh);
2275 
2276 		/* Then nuke all the others ... and advance the
2277 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2278 		 */
2279 		while (!list_empty(&hep->urb_list)) {
2280 			urb = next_urb(qh);
2281 			urb->status = -ESHUTDOWN;
2282 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2283 		}
2284 	} else {
2285 		/* Just empty the queue; the hardware is busy with
2286 		 * other transfers, and since !qh->is_ready nothing
2287 		 * will activate any of these as it advances.
2288 		 */
2289 		while (!list_empty(&hep->urb_list))
2290 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2291 
2292 		hep->hcpriv = NULL;
2293 		list_del(&qh->ring);
2294 		kfree(qh);
2295 	}
2296 exit:
2297 	spin_unlock_irqrestore(&musb->lock, flags);
2298 }
2299 
2300 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2301 {
2302 	struct musb	*musb = hcd_to_musb(hcd);
2303 
2304 	return musb_readw(musb->mregs, MUSB_FRAME);
2305 }
2306 
2307 static int musb_h_start(struct usb_hcd *hcd)
2308 {
2309 	struct musb	*musb = hcd_to_musb(hcd);
2310 
2311 	/* NOTE: musb_start() is called when the hub driver turns
2312 	 * on port power, or when (OTG) peripheral starts.
2313 	 */
2314 	hcd->state = HC_STATE_RUNNING;
2315 	musb->port1_status = 0;
2316 	return 0;
2317 }
2318 
2319 static void musb_h_stop(struct usb_hcd *hcd)
2320 {
2321 	musb_stop(hcd_to_musb(hcd));
2322 	hcd->state = HC_STATE_HALT;
2323 }
2324 
2325 static int musb_bus_suspend(struct usb_hcd *hcd)
2326 {
2327 	struct musb	*musb = hcd_to_musb(hcd);
2328 	u8		devctl;
2329 
2330 	if (!is_host_active(musb))
2331 		return 0;
2332 
2333 	switch (musb->xceiv->state) {
2334 	case OTG_STATE_A_SUSPEND:
2335 		return 0;
2336 	case OTG_STATE_A_WAIT_VRISE:
2337 		/* ID could be grounded even if there's no device
2338 		 * on the other end of the cable.  NOTE that the
2339 		 * A_WAIT_VRISE timers are messy with MUSB...
2340 		 */
2341 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2342 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2343 			musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2344 		break;
2345 	default:
2346 		break;
2347 	}
2348 
2349 	if (musb->is_active) {
2350 		WARNING("trying to suspend as %s while active\n",
2351 				otg_state_string(musb->xceiv->state));
2352 		return -EBUSY;
2353 	} else
2354 		return 0;
2355 }
2356 
2357 static int musb_bus_resume(struct usb_hcd *hcd)
2358 {
2359 	/* resuming child port does the work */
2360 	return 0;
2361 }
2362 
2363 const struct hc_driver musb_hc_driver = {
2364 	.description		= "musb-hcd",
2365 	.product_desc		= "MUSB HDRC host driver",
2366 	.hcd_priv_size		= sizeof(struct musb),
2367 	.flags			= HCD_USB2 | HCD_MEMORY,
2368 
2369 	/* not using irq handler or reset hooks from usbcore, since
2370 	 * those must be shared with peripheral code for OTG configs
2371 	 */
2372 
2373 	.start			= musb_h_start,
2374 	.stop			= musb_h_stop,
2375 
2376 	.get_frame_number	= musb_h_get_frame_number,
2377 
2378 	.urb_enqueue		= musb_urb_enqueue,
2379 	.urb_dequeue		= musb_urb_dequeue,
2380 	.endpoint_disable	= musb_h_disable,
2381 
2382 	.hub_status_data	= musb_hub_status_data,
2383 	.hub_control		= musb_hub_control,
2384 	.bus_suspend		= musb_bus_suspend,
2385 	.bus_resume		= musb_bus_resume,
2386 	/* .start_port_reset	= NULL, */
2387 	/* .hub_irq_enable	= NULL, */
2388 };
2389 #endif
2390