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  */
musb_h_tx_flush_fifo(struct musb_hw_ep * ep)107 static void musb_h_tx_flush_fifo(struct musb_hw_ep *ep)
108 {
109 	void __iomem	*epio = ep->regs;
110 	u16		csr;
111 	u16		lastcsr = 0;
112 	int		retries = 1000;
113 
114 	csr = musb_readw(epio, MUSB_TXCSR);
115 	while (csr & MUSB_TXCSR_FIFONOTEMPTY) {
116 		if (csr != lastcsr)
117 			DBG(3, "Host TX FIFONOTEMPTY csr: %02x\n", csr);
118 		lastcsr = csr;
119 		csr |= MUSB_TXCSR_FLUSHFIFO;
120 		musb_writew(epio, MUSB_TXCSR, csr);
121 		csr = musb_readw(epio, MUSB_TXCSR);
122 		if (WARN(retries-- < 1,
123 				"Could not flush host TX%d fifo: csr: %04x\n",
124 				ep->epnum, csr))
125 			return;
126 		mdelay(1);
127 	}
128 }
129 
musb_h_ep0_flush_fifo(struct musb_hw_ep * ep)130 static void musb_h_ep0_flush_fifo(struct musb_hw_ep *ep)
131 {
132 	void __iomem	*epio = ep->regs;
133 	u16		csr;
134 	int		retries = 5;
135 
136 	/* scrub any data left in the fifo */
137 	do {
138 		csr = musb_readw(epio, MUSB_TXCSR);
139 		if (!(csr & (MUSB_CSR0_TXPKTRDY | MUSB_CSR0_RXPKTRDY)))
140 			break;
141 		musb_writew(epio, MUSB_TXCSR, MUSB_CSR0_FLUSHFIFO);
142 		csr = musb_readw(epio, MUSB_TXCSR);
143 		udelay(10);
144 	} while (--retries);
145 
146 	WARN(!retries, "Could not flush host TX%d fifo: csr: %04x\n",
147 			ep->epnum, csr);
148 
149 	/* and reset for the next transfer */
150 	musb_writew(epio, MUSB_TXCSR, 0);
151 }
152 
153 /*
154  * Start transmit. Caller is responsible for locking shared resources.
155  * musb must be locked.
156  */
musb_h_tx_start(struct musb_hw_ep * ep)157 static inline void musb_h_tx_start(struct musb_hw_ep *ep)
158 {
159 	u16	txcsr;
160 
161 	/* NOTE: no locks here; caller should lock and select EP */
162 	if (ep->epnum) {
163 		txcsr = musb_readw(ep->regs, MUSB_TXCSR);
164 		txcsr |= MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_H_WZC_BITS;
165 		musb_writew(ep->regs, MUSB_TXCSR, txcsr);
166 	} else {
167 		txcsr = MUSB_CSR0_H_SETUPPKT | MUSB_CSR0_TXPKTRDY;
168 		musb_writew(ep->regs, MUSB_CSR0, txcsr);
169 	}
170 
171 }
172 
musb_h_tx_dma_start(struct musb_hw_ep * ep)173 static inline void musb_h_tx_dma_start(struct musb_hw_ep *ep)
174 {
175 	u16	txcsr;
176 
177 	/* NOTE: no locks here; caller should lock and select EP */
178 	txcsr = musb_readw(ep->regs, MUSB_TXCSR);
179 	txcsr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_H_WZC_BITS;
180 	if (is_cppi_enabled())
181 		txcsr |= MUSB_TXCSR_DMAMODE;
182 	musb_writew(ep->regs, MUSB_TXCSR, txcsr);
183 }
184 
musb_ep_set_qh(struct musb_hw_ep * ep,int is_in,struct musb_qh * qh)185 static void musb_ep_set_qh(struct musb_hw_ep *ep, int is_in, struct musb_qh *qh)
186 {
187 	if (is_in != 0 || ep->is_shared_fifo)
188 		ep->in_qh  = qh;
189 	if (is_in == 0 || ep->is_shared_fifo)
190 		ep->out_qh = qh;
191 }
192 
musb_ep_get_qh(struct musb_hw_ep * ep,int is_in)193 static struct musb_qh *musb_ep_get_qh(struct musb_hw_ep *ep, int is_in)
194 {
195 	return is_in ? ep->in_qh : ep->out_qh;
196 }
197 
198 /*
199  * Start the URB at the front of an endpoint's queue
200  * end must be claimed from the caller.
201  *
202  * Context: controller locked, irqs blocked
203  */
204 static void
musb_start_urb(struct musb * musb,int is_in,struct musb_qh * qh)205 musb_start_urb(struct musb *musb, int is_in, struct musb_qh *qh)
206 {
207 	u16			frame;
208 	u32			len;
209 	void __iomem		*mbase =  musb->mregs;
210 	struct urb		*urb = next_urb(qh);
211 	void			*buf = urb->transfer_buffer;
212 	u32			offset = 0;
213 	struct musb_hw_ep	*hw_ep = qh->hw_ep;
214 	unsigned		pipe = urb->pipe;
215 	u8			address = usb_pipedevice(pipe);
216 	int			epnum = hw_ep->epnum;
217 
218 	/* initialize software qh state */
219 	qh->offset = 0;
220 	qh->segsize = 0;
221 
222 	/* gather right source of data */
223 	switch (qh->type) {
224 	case USB_ENDPOINT_XFER_CONTROL:
225 		/* control transfers always start with SETUP */
226 		is_in = 0;
227 		musb->ep0_stage = MUSB_EP0_START;
228 		buf = urb->setup_packet;
229 		len = 8;
230 		break;
231 	case USB_ENDPOINT_XFER_ISOC:
232 		qh->iso_idx = 0;
233 		qh->frame = 0;
234 		offset = urb->iso_frame_desc[0].offset;
235 		len = urb->iso_frame_desc[0].length;
236 		break;
237 	default:		/* bulk, interrupt */
238 		/* actual_length may be nonzero on retry paths */
239 		buf = urb->transfer_buffer + urb->actual_length;
240 		len = urb->transfer_buffer_length - urb->actual_length;
241 	}
242 
243 	DBG(4, "qh %p urb %p dev%d ep%d%s%s, hw_ep %d, %p/%d\n",
244 			qh, urb, address, qh->epnum,
245 			is_in ? "in" : "out",
246 			({char *s; switch (qh->type) {
247 			case USB_ENDPOINT_XFER_CONTROL:	s = ""; break;
248 			case USB_ENDPOINT_XFER_BULK:	s = "-bulk"; break;
249 			case USB_ENDPOINT_XFER_ISOC:	s = "-iso"; break;
250 			default:			s = "-intr"; break;
251 			}; s; }),
252 			epnum, buf + offset, len);
253 
254 	/* Configure endpoint */
255 	musb_ep_set_qh(hw_ep, is_in, qh);
256 	musb_ep_program(musb, epnum, urb, !is_in, buf, offset, len);
257 
258 	/* transmit may have more work: start it when it is time */
259 	if (is_in)
260 		return;
261 
262 	/* determine if the time is right for a periodic transfer */
263 	switch (qh->type) {
264 	case USB_ENDPOINT_XFER_ISOC:
265 	case USB_ENDPOINT_XFER_INT:
266 		DBG(3, "check whether there's still time for periodic Tx\n");
267 		frame = musb_readw(mbase, MUSB_FRAME);
268 		/* FIXME this doesn't implement that scheduling policy ...
269 		 * or handle framecounter wrapping
270 		 */
271 		if ((urb->transfer_flags & URB_ISO_ASAP)
272 				|| (frame >= urb->start_frame)) {
273 			/* REVISIT the SOF irq handler shouldn't duplicate
274 			 * this code; and we don't init urb->start_frame...
275 			 */
276 			qh->frame = 0;
277 			goto start;
278 		} else {
279 			qh->frame = urb->start_frame;
280 			/* enable SOF interrupt so we can count down */
281 			DBG(1, "SOF for %d\n", epnum);
282 #if 1 /* ifndef	CONFIG_ARCH_DAVINCI */
283 			musb_writeb(mbase, MUSB_INTRUSBE, 0xff);
284 #endif
285 		}
286 		break;
287 	default:
288 start:
289 		DBG(4, "Start TX%d %s\n", epnum,
290 			hw_ep->tx_channel ? "dma" : "pio");
291 
292 		if (!hw_ep->tx_channel)
293 			musb_h_tx_start(hw_ep);
294 		else if (is_cppi_enabled() || tusb_dma_omap())
295 			musb_h_tx_dma_start(hw_ep);
296 	}
297 }
298 
299 /* Context: caller owns controller lock, IRQs are blocked */
musb_giveback(struct musb * musb,struct urb * urb,int status)300 static void musb_giveback(struct musb *musb, struct urb *urb, int status)
301 __releases(musb->lock)
302 __acquires(musb->lock)
303 {
304 	DBG(({ int level; switch (status) {
305 				case 0:
306 					level = 4;
307 					break;
308 				/* common/boring faults */
309 				case -EREMOTEIO:
310 				case -ESHUTDOWN:
311 				case -ECONNRESET:
312 				case -EPIPE:
313 					level = 3;
314 					break;
315 				default:
316 					level = 2;
317 					break;
318 				}; level; }),
319 			"complete %p %pF (%d), dev%d ep%d%s, %d/%d\n",
320 			urb, urb->complete, status,
321 			usb_pipedevice(urb->pipe),
322 			usb_pipeendpoint(urb->pipe),
323 			usb_pipein(urb->pipe) ? "in" : "out",
324 			urb->actual_length, urb->transfer_buffer_length
325 			);
326 
327 	usb_hcd_unlink_urb_from_ep(musb_to_hcd(musb), urb);
328 	spin_unlock(&musb->lock);
329 	usb_hcd_giveback_urb(musb_to_hcd(musb), urb, status);
330 	spin_lock(&musb->lock);
331 }
332 
333 /* For bulk/interrupt endpoints only */
musb_save_toggle(struct musb_qh * qh,int is_in,struct urb * urb)334 static inline void musb_save_toggle(struct musb_qh *qh, int is_in,
335 				    struct urb *urb)
336 {
337 	void __iomem		*epio = qh->hw_ep->regs;
338 	u16			csr;
339 
340 	/*
341 	 * FIXME: the current Mentor DMA code seems to have
342 	 * problems getting toggle correct.
343 	 */
344 
345 	if (is_in)
346 		csr = musb_readw(epio, MUSB_RXCSR) & MUSB_RXCSR_H_DATATOGGLE;
347 	else
348 		csr = musb_readw(epio, MUSB_TXCSR) & MUSB_TXCSR_H_DATATOGGLE;
349 
350 	usb_settoggle(urb->dev, qh->epnum, !is_in, csr ? 1 : 0);
351 }
352 
353 /*
354  * Advance this hardware endpoint's queue, completing the specified URB and
355  * advancing to either the next URB queued to that qh, or else invalidating
356  * that qh and advancing to the next qh scheduled after the current one.
357  *
358  * Context: caller owns controller lock, IRQs are blocked
359  */
musb_advance_schedule(struct musb * musb,struct urb * urb,struct musb_hw_ep * hw_ep,int is_in)360 static void musb_advance_schedule(struct musb *musb, struct urb *urb,
361 				  struct musb_hw_ep *hw_ep, int is_in)
362 {
363 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, is_in);
364 	struct musb_hw_ep	*ep = qh->hw_ep;
365 	int			ready = qh->is_ready;
366 	int			status;
367 
368 	status = (urb->status == -EINPROGRESS) ? 0 : urb->status;
369 
370 	/* save toggle eagerly, for paranoia */
371 	switch (qh->type) {
372 	case USB_ENDPOINT_XFER_BULK:
373 	case USB_ENDPOINT_XFER_INT:
374 		musb_save_toggle(qh, is_in, urb);
375 		break;
376 	case USB_ENDPOINT_XFER_ISOC:
377 		if (status == 0 && urb->error_count)
378 			status = -EXDEV;
379 		break;
380 	}
381 
382 	qh->is_ready = 0;
383 	musb_giveback(musb, urb, status);
384 	qh->is_ready = ready;
385 
386 	/* reclaim resources (and bandwidth) ASAP; deschedule it, and
387 	 * invalidate qh as soon as list_empty(&hep->urb_list)
388 	 */
389 	if (list_empty(&qh->hep->urb_list)) {
390 		struct list_head	*head;
391 
392 		if (is_in)
393 			ep->rx_reinit = 1;
394 		else
395 			ep->tx_reinit = 1;
396 
397 		/* Clobber old pointers to this qh */
398 		musb_ep_set_qh(ep, is_in, NULL);
399 		qh->hep->hcpriv = NULL;
400 
401 		switch (qh->type) {
402 
403 		case USB_ENDPOINT_XFER_CONTROL:
404 		case USB_ENDPOINT_XFER_BULK:
405 			/* fifo policy for these lists, except that NAKing
406 			 * should rotate a qh to the end (for fairness).
407 			 */
408 			if (qh->mux == 1) {
409 				head = qh->ring.prev;
410 				list_del(&qh->ring);
411 				kfree(qh);
412 				qh = first_qh(head);
413 				break;
414 			}
415 
416 		case USB_ENDPOINT_XFER_ISOC:
417 		case USB_ENDPOINT_XFER_INT:
418 			/* this is where periodic bandwidth should be
419 			 * de-allocated if it's tracked and allocated;
420 			 * and where we'd update the schedule tree...
421 			 */
422 			kfree(qh);
423 			qh = NULL;
424 			break;
425 		}
426 	}
427 
428 	if (qh != NULL && qh->is_ready) {
429 		DBG(4, "... next ep%d %cX urb %p\n",
430 		    hw_ep->epnum, is_in ? 'R' : 'T', next_urb(qh));
431 		musb_start_urb(musb, is_in, qh);
432 	}
433 }
434 
musb_h_flush_rxfifo(struct musb_hw_ep * hw_ep,u16 csr)435 static u16 musb_h_flush_rxfifo(struct musb_hw_ep *hw_ep, u16 csr)
436 {
437 	/* we don't want fifo to fill itself again;
438 	 * ignore dma (various models),
439 	 * leave toggle alone (may not have been saved yet)
440 	 */
441 	csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_RXPKTRDY;
442 	csr &= ~(MUSB_RXCSR_H_REQPKT
443 		| MUSB_RXCSR_H_AUTOREQ
444 		| MUSB_RXCSR_AUTOCLEAR);
445 
446 	/* write 2x to allow double buffering */
447 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
448 	musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
449 
450 	/* flush writebuffer */
451 	return musb_readw(hw_ep->regs, MUSB_RXCSR);
452 }
453 
454 /*
455  * PIO RX for a packet (or part of it).
456  */
457 static bool
musb_host_packet_rx(struct musb * musb,struct urb * urb,u8 epnum,u8 iso_err)458 musb_host_packet_rx(struct musb *musb, struct urb *urb, u8 epnum, u8 iso_err)
459 {
460 	u16			rx_count;
461 	u8			*buf;
462 	u16			csr;
463 	bool			done = false;
464 	u32			length;
465 	int			do_flush = 0;
466 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
467 	void __iomem		*epio = hw_ep->regs;
468 	struct musb_qh		*qh = hw_ep->in_qh;
469 	int			pipe = urb->pipe;
470 	void			*buffer = urb->transfer_buffer;
471 
472 	/* musb_ep_select(mbase, epnum); */
473 	rx_count = musb_readw(epio, MUSB_RXCOUNT);
474 	DBG(3, "RX%d count %d, buffer %p len %d/%d\n", epnum, rx_count,
475 			urb->transfer_buffer, qh->offset,
476 			urb->transfer_buffer_length);
477 
478 	/* unload FIFO */
479 	if (usb_pipeisoc(pipe)) {
480 		int					status = 0;
481 		struct usb_iso_packet_descriptor	*d;
482 
483 		if (iso_err) {
484 			status = -EILSEQ;
485 			urb->error_count++;
486 		}
487 
488 		d = urb->iso_frame_desc + qh->iso_idx;
489 		buf = buffer + d->offset;
490 		length = d->length;
491 		if (rx_count > length) {
492 			if (status == 0) {
493 				status = -EOVERFLOW;
494 				urb->error_count++;
495 			}
496 			DBG(2, "** OVERFLOW %d into %d\n", rx_count, length);
497 			do_flush = 1;
498 		} else
499 			length = rx_count;
500 		urb->actual_length += length;
501 		d->actual_length = length;
502 
503 		d->status = status;
504 
505 		/* see if we are done */
506 		done = (++qh->iso_idx >= urb->number_of_packets);
507 	} else {
508 		/* non-isoch */
509 		buf = buffer + qh->offset;
510 		length = urb->transfer_buffer_length - qh->offset;
511 		if (rx_count > length) {
512 			if (urb->status == -EINPROGRESS)
513 				urb->status = -EOVERFLOW;
514 			DBG(2, "** OVERFLOW %d into %d\n", rx_count, length);
515 			do_flush = 1;
516 		} else
517 			length = rx_count;
518 		urb->actual_length += length;
519 		qh->offset += length;
520 
521 		/* see if we are done */
522 		done = (urb->actual_length == urb->transfer_buffer_length)
523 			|| (rx_count < qh->maxpacket)
524 			|| (urb->status != -EINPROGRESS);
525 		if (done
526 				&& (urb->status == -EINPROGRESS)
527 				&& (urb->transfer_flags & URB_SHORT_NOT_OK)
528 				&& (urb->actual_length
529 					< urb->transfer_buffer_length))
530 			urb->status = -EREMOTEIO;
531 	}
532 
533 	musb_read_fifo(hw_ep, length, buf);
534 
535 	csr = musb_readw(epio, MUSB_RXCSR);
536 	csr |= MUSB_RXCSR_H_WZC_BITS;
537 	if (unlikely(do_flush))
538 		musb_h_flush_rxfifo(hw_ep, csr);
539 	else {
540 		/* REVISIT this assumes AUTOCLEAR is never set */
541 		csr &= ~(MUSB_RXCSR_RXPKTRDY | MUSB_RXCSR_H_REQPKT);
542 		if (!done)
543 			csr |= MUSB_RXCSR_H_REQPKT;
544 		musb_writew(epio, MUSB_RXCSR, csr);
545 	}
546 
547 	return done;
548 }
549 
550 /* we don't always need to reinit a given side of an endpoint...
551  * when we do, use tx/rx reinit routine and then construct a new CSR
552  * to address data toggle, NYET, and DMA or PIO.
553  *
554  * it's possible that driver bugs (especially for DMA) or aborting a
555  * transfer might have left the endpoint busier than it should be.
556  * the busy/not-empty tests are basically paranoia.
557  */
558 static void
musb_rx_reinit(struct musb * musb,struct musb_qh * qh,struct musb_hw_ep * ep)559 musb_rx_reinit(struct musb *musb, struct musb_qh *qh, struct musb_hw_ep *ep)
560 {
561 	u16	csr;
562 
563 	/* NOTE:  we know the "rx" fifo reinit never triggers for ep0.
564 	 * That always uses tx_reinit since ep0 repurposes TX register
565 	 * offsets; the initial SETUP packet is also a kind of OUT.
566 	 */
567 
568 	/* if programmed for Tx, put it in RX mode */
569 	if (ep->is_shared_fifo) {
570 		csr = musb_readw(ep->regs, MUSB_TXCSR);
571 		if (csr & MUSB_TXCSR_MODE) {
572 			musb_h_tx_flush_fifo(ep);
573 			csr = musb_readw(ep->regs, MUSB_TXCSR);
574 			musb_writew(ep->regs, MUSB_TXCSR,
575 				    csr | MUSB_TXCSR_FRCDATATOG);
576 		}
577 
578 		/*
579 		 * Clear the MODE bit (and everything else) to enable Rx.
580 		 * NOTE: we mustn't clear the DMAMODE bit before DMAENAB.
581 		 */
582 		if (csr & MUSB_TXCSR_DMAMODE)
583 			musb_writew(ep->regs, MUSB_TXCSR, MUSB_TXCSR_DMAMODE);
584 		musb_writew(ep->regs, MUSB_TXCSR, 0);
585 
586 	/* scrub all previous state, clearing toggle */
587 	} else {
588 		csr = musb_readw(ep->regs, MUSB_RXCSR);
589 		if (csr & MUSB_RXCSR_RXPKTRDY)
590 			WARNING("rx%d, packet/%d ready?\n", ep->epnum,
591 				musb_readw(ep->regs, MUSB_RXCOUNT));
592 
593 		musb_h_flush_rxfifo(ep, MUSB_RXCSR_CLRDATATOG);
594 	}
595 
596 	/* target addr and (for multipoint) hub addr/port */
597 	if (musb->is_multipoint) {
598 		musb_write_rxfunaddr(ep->target_regs, qh->addr_reg);
599 		musb_write_rxhubaddr(ep->target_regs, qh->h_addr_reg);
600 		musb_write_rxhubport(ep->target_regs, qh->h_port_reg);
601 
602 	} else
603 		musb_writeb(musb->mregs, MUSB_FADDR, qh->addr_reg);
604 
605 	/* protocol/endpoint, interval/NAKlimit, i/o size */
606 	musb_writeb(ep->regs, MUSB_RXTYPE, qh->type_reg);
607 	musb_writeb(ep->regs, MUSB_RXINTERVAL, qh->intv_reg);
608 	/* NOTE: bulk combining rewrites high bits of maxpacket */
609 	/* Set RXMAXP with the FIFO size of the endpoint
610 	 * to disable double buffer mode.
611 	 */
612 	if (musb->double_buffer_not_ok)
613 		musb_writew(ep->regs, MUSB_RXMAXP, ep->max_packet_sz_rx);
614 	else
615 		musb_writew(ep->regs, MUSB_RXMAXP,
616 				qh->maxpacket | ((qh->hb_mult - 1) << 11));
617 
618 	ep->rx_reinit = 0;
619 }
620 
musb_tx_dma_program(struct dma_controller * dma,struct musb_hw_ep * hw_ep,struct musb_qh * qh,struct urb * urb,u32 offset,u32 length)621 static bool musb_tx_dma_program(struct dma_controller *dma,
622 		struct musb_hw_ep *hw_ep, struct musb_qh *qh,
623 		struct urb *urb, u32 offset, u32 length)
624 {
625 	struct dma_channel	*channel = hw_ep->tx_channel;
626 	void __iomem		*epio = hw_ep->regs;
627 	u16			pkt_size = qh->maxpacket;
628 	u16			csr;
629 	u8			mode;
630 
631 #ifdef	CONFIG_USB_INVENTRA_DMA
632 	if (length > channel->max_len)
633 		length = channel->max_len;
634 
635 	csr = musb_readw(epio, MUSB_TXCSR);
636 	if (length > pkt_size) {
637 		mode = 1;
638 		csr |= MUSB_TXCSR_DMAMODE | MUSB_TXCSR_DMAENAB;
639 		/* autoset shouldn't be set in high bandwidth */
640 		if (qh->hb_mult == 1)
641 			csr |= MUSB_TXCSR_AUTOSET;
642 	} else {
643 		mode = 0;
644 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAMODE);
645 		csr |= MUSB_TXCSR_DMAENAB; /* against programmer's guide */
646 	}
647 	channel->desired_mode = mode;
648 	musb_writew(epio, MUSB_TXCSR, csr);
649 #else
650 	if (!is_cppi_enabled() && !tusb_dma_omap())
651 		return false;
652 
653 	channel->actual_len = 0;
654 
655 	/*
656 	 * TX uses "RNDIS" mode automatically but needs help
657 	 * to identify the zero-length-final-packet case.
658 	 */
659 	mode = (urb->transfer_flags & URB_ZERO_PACKET) ? 1 : 0;
660 #endif
661 
662 	qh->segsize = length;
663 
664 	/*
665 	 * Ensure the data reaches to main memory before starting
666 	 * DMA transfer
667 	 */
668 	wmb();
669 
670 	if (!dma->channel_program(channel, pkt_size, mode,
671 			urb->transfer_dma + offset, length)) {
672 		dma->channel_release(channel);
673 		hw_ep->tx_channel = NULL;
674 
675 		csr = musb_readw(epio, MUSB_TXCSR);
676 		csr &= ~(MUSB_TXCSR_AUTOSET | MUSB_TXCSR_DMAENAB);
677 		musb_writew(epio, MUSB_TXCSR, csr | MUSB_TXCSR_H_WZC_BITS);
678 		return false;
679 	}
680 	return true;
681 }
682 
683 /*
684  * Program an HDRC endpoint as per the given URB
685  * Context: irqs blocked, controller lock held
686  */
musb_ep_program(struct musb * musb,u8 epnum,struct urb * urb,int is_out,u8 * buf,u32 offset,u32 len)687 static void musb_ep_program(struct musb *musb, u8 epnum,
688 			struct urb *urb, int is_out,
689 			u8 *buf, u32 offset, u32 len)
690 {
691 	struct dma_controller	*dma_controller;
692 	struct dma_channel	*dma_channel;
693 	u8			dma_ok;
694 	void __iomem		*mbase = musb->mregs;
695 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
696 	void __iomem		*epio = hw_ep->regs;
697 	struct musb_qh		*qh = musb_ep_get_qh(hw_ep, !is_out);
698 	u16			packet_sz = qh->maxpacket;
699 
700 	DBG(3, "%s hw%d urb %p spd%d dev%d ep%d%s "
701 				"h_addr%02x h_port%02x bytes %d\n",
702 			is_out ? "-->" : "<--",
703 			epnum, urb, urb->dev->speed,
704 			qh->addr_reg, qh->epnum, is_out ? "out" : "in",
705 			qh->h_addr_reg, qh->h_port_reg,
706 			len);
707 
708 	musb_ep_select(mbase, epnum);
709 
710 	/* candidate for DMA? */
711 	dma_controller = musb->dma_controller;
712 	if (is_dma_capable() && epnum && dma_controller) {
713 		dma_channel = is_out ? hw_ep->tx_channel : hw_ep->rx_channel;
714 		if (!dma_channel) {
715 			dma_channel = dma_controller->channel_alloc(
716 					dma_controller, hw_ep, is_out);
717 			if (is_out)
718 				hw_ep->tx_channel = dma_channel;
719 			else
720 				hw_ep->rx_channel = dma_channel;
721 		}
722 	} else
723 		dma_channel = NULL;
724 
725 	/* make sure we clear DMAEnab, autoSet bits from previous run */
726 
727 	/* OUT/transmit/EP0 or IN/receive? */
728 	if (is_out) {
729 		u16	csr;
730 		u16	int_txe;
731 		u16	load_count;
732 
733 		csr = musb_readw(epio, MUSB_TXCSR);
734 
735 		/* disable interrupt in case we flush */
736 		int_txe = musb_readw(mbase, MUSB_INTRTXE);
737 		musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
738 
739 		/* general endpoint setup */
740 		if (epnum) {
741 			/* flush all old state, set default */
742 			musb_h_tx_flush_fifo(hw_ep);
743 
744 			/*
745 			 * We must not clear the DMAMODE bit before or in
746 			 * the same cycle with the DMAENAB bit, so we clear
747 			 * the latter first...
748 			 */
749 			csr &= ~(MUSB_TXCSR_H_NAKTIMEOUT
750 					| MUSB_TXCSR_AUTOSET
751 					| MUSB_TXCSR_DMAENAB
752 					| MUSB_TXCSR_FRCDATATOG
753 					| MUSB_TXCSR_H_RXSTALL
754 					| MUSB_TXCSR_H_ERROR
755 					| MUSB_TXCSR_TXPKTRDY
756 					);
757 			csr |= MUSB_TXCSR_MODE;
758 
759 			if (usb_gettoggle(urb->dev, qh->epnum, 1))
760 				csr |= MUSB_TXCSR_H_WR_DATATOGGLE
761 					| MUSB_TXCSR_H_DATATOGGLE;
762 			else
763 				csr |= MUSB_TXCSR_CLRDATATOG;
764 
765 			musb_writew(epio, MUSB_TXCSR, csr);
766 			/* REVISIT may need to clear FLUSHFIFO ... */
767 			csr &= ~MUSB_TXCSR_DMAMODE;
768 			musb_writew(epio, MUSB_TXCSR, csr);
769 			csr = musb_readw(epio, MUSB_TXCSR);
770 		} else {
771 			/* endpoint 0: just flush */
772 			musb_h_ep0_flush_fifo(hw_ep);
773 		}
774 
775 		/* target addr and (for multipoint) hub addr/port */
776 		if (musb->is_multipoint) {
777 			musb_write_txfunaddr(mbase, epnum, qh->addr_reg);
778 			musb_write_txhubaddr(mbase, epnum, qh->h_addr_reg);
779 			musb_write_txhubport(mbase, epnum, qh->h_port_reg);
780 /* FIXME if !epnum, do the same for RX ... */
781 		} else
782 			musb_writeb(mbase, MUSB_FADDR, qh->addr_reg);
783 
784 		/* protocol/endpoint/interval/NAKlimit */
785 		if (epnum) {
786 			musb_writeb(epio, MUSB_TXTYPE, qh->type_reg);
787 			if (musb->double_buffer_not_ok)
788 				musb_writew(epio, MUSB_TXMAXP,
789 						hw_ep->max_packet_sz_tx);
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 			if (dma_channel) {
855 				dma_channel->actual_len = 0L;
856 				qh->segsize = len;
857 
858 				/* AUTOREQ is in a DMA register */
859 				musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
860 				csr = musb_readw(hw_ep->regs,
861 						MUSB_RXCSR);
862 
863 				/* unless caller treats short rx transfers as
864 				 * errors, we dare not queue multiple transfers.
865 				 */
866 				dma_ok = dma_controller->channel_program(
867 						dma_channel, packet_sz,
868 						!(urb->transfer_flags
869 							& URB_SHORT_NOT_OK),
870 						urb->transfer_dma + offset,
871 						qh->segsize);
872 				if (!dma_ok) {
873 					dma_controller->channel_release(
874 							dma_channel);
875 					hw_ep->rx_channel = NULL;
876 					dma_channel = NULL;
877 				} else
878 					csr |= MUSB_RXCSR_DMAENAB;
879 			}
880 		}
881 
882 		csr |= MUSB_RXCSR_H_REQPKT;
883 		DBG(7, "RXCSR%d := %04x\n", epnum, csr);
884 		musb_writew(hw_ep->regs, MUSB_RXCSR, csr);
885 		csr = musb_readw(hw_ep->regs, MUSB_RXCSR);
886 	}
887 }
888 
889 
890 /*
891  * Service the default endpoint (ep0) as host.
892  * Return true until it's time to start the status stage.
893  */
musb_h_ep0_continue(struct musb * musb,u16 len,struct urb * urb)894 static bool musb_h_ep0_continue(struct musb *musb, u16 len, struct urb *urb)
895 {
896 	bool			 more = false;
897 	u8			*fifo_dest = NULL;
898 	u16			fifo_count = 0;
899 	struct musb_hw_ep	*hw_ep = musb->control_ep;
900 	struct musb_qh		*qh = hw_ep->in_qh;
901 	struct usb_ctrlrequest	*request;
902 
903 	switch (musb->ep0_stage) {
904 	case MUSB_EP0_IN:
905 		fifo_dest = urb->transfer_buffer + urb->actual_length;
906 		fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
907 				   urb->actual_length);
908 		if (fifo_count < len)
909 			urb->status = -EOVERFLOW;
910 
911 		musb_read_fifo(hw_ep, fifo_count, fifo_dest);
912 
913 		urb->actual_length += fifo_count;
914 		if (len < qh->maxpacket) {
915 			/* always terminate on short read; it's
916 			 * rarely reported as an error.
917 			 */
918 		} else if (urb->actual_length <
919 				urb->transfer_buffer_length)
920 			more = true;
921 		break;
922 	case MUSB_EP0_START:
923 		request = (struct usb_ctrlrequest *) urb->setup_packet;
924 
925 		if (!request->wLength) {
926 			DBG(4, "start no-DATA\n");
927 			break;
928 		} else if (request->bRequestType & USB_DIR_IN) {
929 			DBG(4, "start IN-DATA\n");
930 			musb->ep0_stage = MUSB_EP0_IN;
931 			more = true;
932 			break;
933 		} else {
934 			DBG(4, "start OUT-DATA\n");
935 			musb->ep0_stage = MUSB_EP0_OUT;
936 			more = true;
937 		}
938 		/* FALLTHROUGH */
939 	case MUSB_EP0_OUT:
940 		fifo_count = min_t(size_t, qh->maxpacket,
941 				   urb->transfer_buffer_length -
942 				   urb->actual_length);
943 		if (fifo_count) {
944 			fifo_dest = (u8 *) (urb->transfer_buffer
945 					+ urb->actual_length);
946 			DBG(3, "Sending %d byte%s to ep0 fifo %p\n",
947 					fifo_count,
948 					(fifo_count == 1) ? "" : "s",
949 					fifo_dest);
950 			musb_write_fifo(hw_ep, fifo_count, fifo_dest);
951 
952 			urb->actual_length += fifo_count;
953 			more = true;
954 		}
955 		break;
956 	default:
957 		ERR("bogus ep0 stage %d\n", musb->ep0_stage);
958 		break;
959 	}
960 
961 	return more;
962 }
963 
964 /*
965  * Handle default endpoint interrupt as host. Only called in IRQ time
966  * from musb_interrupt().
967  *
968  * called with controller irqlocked
969  */
musb_h_ep0_irq(struct musb * musb)970 irqreturn_t musb_h_ep0_irq(struct musb *musb)
971 {
972 	struct urb		*urb;
973 	u16			csr, len;
974 	int			status = 0;
975 	void __iomem		*mbase = musb->mregs;
976 	struct musb_hw_ep	*hw_ep = musb->control_ep;
977 	void __iomem		*epio = hw_ep->regs;
978 	struct musb_qh		*qh = hw_ep->in_qh;
979 	bool			complete = false;
980 	irqreturn_t		retval = IRQ_NONE;
981 
982 	/* ep0 only has one queue, "in" */
983 	urb = next_urb(qh);
984 
985 	musb_ep_select(mbase, 0);
986 	csr = musb_readw(epio, MUSB_CSR0);
987 	len = (csr & MUSB_CSR0_RXPKTRDY)
988 			? musb_readb(epio, MUSB_COUNT0)
989 			: 0;
990 
991 	DBG(4, "<== csr0 %04x, qh %p, count %d, urb %p, stage %d\n",
992 		csr, qh, len, urb, musb->ep0_stage);
993 
994 	/* if we just did status stage, we are done */
995 	if (MUSB_EP0_STATUS == musb->ep0_stage) {
996 		retval = IRQ_HANDLED;
997 		complete = true;
998 	}
999 
1000 	/* prepare status */
1001 	if (csr & MUSB_CSR0_H_RXSTALL) {
1002 		DBG(6, "STALLING ENDPOINT\n");
1003 		status = -EPIPE;
1004 
1005 	} else if (csr & MUSB_CSR0_H_ERROR) {
1006 		DBG(2, "no response, csr0 %04x\n", csr);
1007 		status = -EPROTO;
1008 
1009 	} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
1010 		DBG(2, "control NAK timeout\n");
1011 
1012 		/* NOTE:  this code path would be a good place to PAUSE a
1013 		 * control transfer, if another one is queued, so that
1014 		 * ep0 is more likely to stay busy.  That's already done
1015 		 * for bulk RX transfers.
1016 		 *
1017 		 * if (qh->ring.next != &musb->control), then
1018 		 * we have a candidate... NAKing is *NOT* an error
1019 		 */
1020 		musb_writew(epio, MUSB_CSR0, 0);
1021 		retval = IRQ_HANDLED;
1022 	}
1023 
1024 	if (status) {
1025 		DBG(6, "aborting\n");
1026 		retval = IRQ_HANDLED;
1027 		if (urb)
1028 			urb->status = status;
1029 		complete = true;
1030 
1031 		/* use the proper sequence to abort the transfer */
1032 		if (csr & MUSB_CSR0_H_REQPKT) {
1033 			csr &= ~MUSB_CSR0_H_REQPKT;
1034 			musb_writew(epio, MUSB_CSR0, csr);
1035 			csr &= ~MUSB_CSR0_H_NAKTIMEOUT;
1036 			musb_writew(epio, MUSB_CSR0, csr);
1037 		} else {
1038 			musb_h_ep0_flush_fifo(hw_ep);
1039 		}
1040 
1041 		musb_writeb(epio, MUSB_NAKLIMIT0, 0);
1042 
1043 		/* clear it */
1044 		musb_writew(epio, MUSB_CSR0, 0);
1045 	}
1046 
1047 	if (unlikely(!urb)) {
1048 		/* stop endpoint since we have no place for its data, this
1049 		 * SHOULD NEVER HAPPEN! */
1050 		ERR("no URB for end 0\n");
1051 
1052 		musb_h_ep0_flush_fifo(hw_ep);
1053 		goto done;
1054 	}
1055 
1056 	if (!complete) {
1057 		/* call common logic and prepare response */
1058 		if (musb_h_ep0_continue(musb, len, urb)) {
1059 			/* more packets required */
1060 			csr = (MUSB_EP0_IN == musb->ep0_stage)
1061 				?  MUSB_CSR0_H_REQPKT : MUSB_CSR0_TXPKTRDY;
1062 		} else {
1063 			/* data transfer complete; perform status phase */
1064 			if (usb_pipeout(urb->pipe)
1065 					|| !urb->transfer_buffer_length)
1066 				csr = MUSB_CSR0_H_STATUSPKT
1067 					| MUSB_CSR0_H_REQPKT;
1068 			else
1069 				csr = MUSB_CSR0_H_STATUSPKT
1070 					| MUSB_CSR0_TXPKTRDY;
1071 
1072 			/* flag status stage */
1073 			musb->ep0_stage = MUSB_EP0_STATUS;
1074 
1075 			DBG(5, "ep0 STATUS, csr %04x\n", csr);
1076 
1077 		}
1078 		musb_writew(epio, MUSB_CSR0, csr);
1079 		retval = IRQ_HANDLED;
1080 	} else
1081 		musb->ep0_stage = MUSB_EP0_IDLE;
1082 
1083 	/* call completion handler if done */
1084 	if (complete)
1085 		musb_advance_schedule(musb, urb, hw_ep, 1);
1086 done:
1087 	return retval;
1088 }
1089 
1090 
1091 #ifdef CONFIG_USB_INVENTRA_DMA
1092 
1093 /* Host side TX (OUT) using Mentor DMA works as follows:
1094 	submit_urb ->
1095 		- if queue was empty, Program Endpoint
1096 		- ... which starts DMA to fifo in mode 1 or 0
1097 
1098 	DMA Isr (transfer complete) -> TxAvail()
1099 		- Stop DMA (~DmaEnab)	(<--- Alert ... currently happens
1100 					only in musb_cleanup_urb)
1101 		- TxPktRdy has to be set in mode 0 or for
1102 			short packets in mode 1.
1103 */
1104 
1105 #endif
1106 
1107 /* Service a Tx-Available or dma completion irq for the endpoint */
musb_host_tx(struct musb * musb,u8 epnum)1108 void musb_host_tx(struct musb *musb, u8 epnum)
1109 {
1110 	int			pipe;
1111 	bool			done = false;
1112 	u16			tx_csr;
1113 	size_t			length = 0;
1114 	size_t			offset = 0;
1115 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1116 	void __iomem		*epio = hw_ep->regs;
1117 	struct musb_qh		*qh = hw_ep->out_qh;
1118 	struct urb		*urb = next_urb(qh);
1119 	u32			status = 0;
1120 	void __iomem		*mbase = musb->mregs;
1121 	struct dma_channel	*dma;
1122 	bool			transfer_pending = false;
1123 
1124 	musb_ep_select(mbase, epnum);
1125 	tx_csr = musb_readw(epio, MUSB_TXCSR);
1126 
1127 	/* with CPPI, DMA sometimes triggers "extra" irqs */
1128 	if (!urb) {
1129 		DBG(4, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1130 		return;
1131 	}
1132 
1133 	pipe = urb->pipe;
1134 	dma = is_dma_capable() ? hw_ep->tx_channel : NULL;
1135 	DBG(4, "OUT/TX%d end, csr %04x%s\n", epnum, tx_csr,
1136 			dma ? ", dma" : "");
1137 
1138 	/* check for errors */
1139 	if (tx_csr & MUSB_TXCSR_H_RXSTALL) {
1140 		/* dma was disabled, fifo flushed */
1141 		DBG(3, "TX end %d stall\n", epnum);
1142 
1143 		/* stall; record URB status */
1144 		status = -EPIPE;
1145 
1146 	} else if (tx_csr & MUSB_TXCSR_H_ERROR) {
1147 		/* (NON-ISO) dma was disabled, fifo flushed */
1148 		DBG(3, "TX 3strikes on ep=%d\n", epnum);
1149 
1150 		status = -ETIMEDOUT;
1151 
1152 	} else if (tx_csr & MUSB_TXCSR_H_NAKTIMEOUT) {
1153 		DBG(6, "TX end=%d device not responding\n", epnum);
1154 
1155 		/* NOTE:  this code path would be a good place to PAUSE a
1156 		 * transfer, if there's some other (nonperiodic) tx urb
1157 		 * that could use this fifo.  (dma complicates it...)
1158 		 * That's already done for bulk RX transfers.
1159 		 *
1160 		 * if (bulk && qh->ring.next != &musb->out_bulk), then
1161 		 * we have a candidate... NAKing is *NOT* an error
1162 		 */
1163 		musb_ep_select(mbase, epnum);
1164 		musb_writew(epio, MUSB_TXCSR,
1165 				MUSB_TXCSR_H_WZC_BITS
1166 				| MUSB_TXCSR_TXPKTRDY);
1167 		return;
1168 	}
1169 
1170 	if (status) {
1171 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1172 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1173 			(void) musb->dma_controller->channel_abort(dma);
1174 		}
1175 
1176 		/* do the proper sequence to abort the transfer in the
1177 		 * usb core; the dma engine should already be stopped.
1178 		 */
1179 		musb_h_tx_flush_fifo(hw_ep);
1180 		tx_csr &= ~(MUSB_TXCSR_AUTOSET
1181 				| MUSB_TXCSR_DMAENAB
1182 				| MUSB_TXCSR_H_ERROR
1183 				| MUSB_TXCSR_H_RXSTALL
1184 				| MUSB_TXCSR_H_NAKTIMEOUT
1185 				);
1186 
1187 		musb_ep_select(mbase, epnum);
1188 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1189 		/* REVISIT may need to clear FLUSHFIFO ... */
1190 		musb_writew(epio, MUSB_TXCSR, tx_csr);
1191 		musb_writeb(epio, MUSB_TXINTERVAL, 0);
1192 
1193 		done = true;
1194 	}
1195 
1196 	/* second cppi case */
1197 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1198 		DBG(4, "extra TX%d ready, csr %04x\n", epnum, tx_csr);
1199 		return;
1200 	}
1201 
1202 	if (is_dma_capable() && dma && !status) {
1203 		/*
1204 		 * DMA has completed.  But if we're using DMA mode 1 (multi
1205 		 * packet DMA), we need a terminal TXPKTRDY interrupt before
1206 		 * we can consider this transfer completed, lest we trash
1207 		 * its last packet when writing the next URB's data.  So we
1208 		 * switch back to mode 0 to get that interrupt; we'll come
1209 		 * back here once it happens.
1210 		 */
1211 		if (tx_csr & MUSB_TXCSR_DMAMODE) {
1212 			/*
1213 			 * We shouldn't clear DMAMODE with DMAENAB set; so
1214 			 * clear them in a safe order.  That should be OK
1215 			 * once TXPKTRDY has been set (and I've never seen
1216 			 * it being 0 at this moment -- DMA interrupt latency
1217 			 * is significant) but if it hasn't been then we have
1218 			 * no choice but to stop being polite and ignore the
1219 			 * programmer's guide... :-)
1220 			 *
1221 			 * Note that we must write TXCSR with TXPKTRDY cleared
1222 			 * in order not to re-trigger the packet send (this bit
1223 			 * can't be cleared by CPU), and there's another caveat:
1224 			 * TXPKTRDY may be set shortly and then cleared in the
1225 			 * double-buffered FIFO mode, so we do an extra TXCSR
1226 			 * read for debouncing...
1227 			 */
1228 			tx_csr &= musb_readw(epio, MUSB_TXCSR);
1229 			if (tx_csr & MUSB_TXCSR_TXPKTRDY) {
1230 				tx_csr &= ~(MUSB_TXCSR_DMAENAB |
1231 					    MUSB_TXCSR_TXPKTRDY);
1232 				musb_writew(epio, MUSB_TXCSR,
1233 					    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1234 			}
1235 			tx_csr &= ~(MUSB_TXCSR_DMAMODE |
1236 				    MUSB_TXCSR_TXPKTRDY);
1237 			musb_writew(epio, MUSB_TXCSR,
1238 				    tx_csr | MUSB_TXCSR_H_WZC_BITS);
1239 
1240 			/*
1241 			 * There is no guarantee that we'll get an interrupt
1242 			 * after clearing DMAMODE as we might have done this
1243 			 * too late (after TXPKTRDY was cleared by controller).
1244 			 * Re-read TXCSR as we have spoiled its previous value.
1245 			 */
1246 			tx_csr = musb_readw(epio, MUSB_TXCSR);
1247 		}
1248 
1249 		/*
1250 		 * We may get here from a DMA completion or TXPKTRDY interrupt.
1251 		 * In any case, we must check the FIFO status here and bail out
1252 		 * only if the FIFO still has data -- that should prevent the
1253 		 * "missed" TXPKTRDY interrupts and deal with double-buffered
1254 		 * FIFO mode too...
1255 		 */
1256 		if (tx_csr & (MUSB_TXCSR_FIFONOTEMPTY | MUSB_TXCSR_TXPKTRDY)) {
1257 			DBG(2, "DMA complete but packet still in FIFO, "
1258 			    "CSR %04x\n", tx_csr);
1259 			return;
1260 		}
1261 	}
1262 
1263 	if (!status || dma || usb_pipeisoc(pipe)) {
1264 		if (dma)
1265 			length = dma->actual_len;
1266 		else
1267 			length = qh->segsize;
1268 		qh->offset += length;
1269 
1270 		if (usb_pipeisoc(pipe)) {
1271 			struct usb_iso_packet_descriptor	*d;
1272 
1273 			d = urb->iso_frame_desc + qh->iso_idx;
1274 			d->actual_length = length;
1275 			d->status = status;
1276 			if (++qh->iso_idx >= urb->number_of_packets) {
1277 				done = true;
1278 			} else {
1279 				d++;
1280 				offset = d->offset;
1281 				length = d->length;
1282 			}
1283 		} else if (dma && urb->transfer_buffer_length == qh->offset) {
1284 			done = true;
1285 		} else {
1286 			/* see if we need to send more data, or ZLP */
1287 			if (qh->segsize < qh->maxpacket)
1288 				done = true;
1289 			else if (qh->offset == urb->transfer_buffer_length
1290 					&& !(urb->transfer_flags
1291 						& URB_ZERO_PACKET))
1292 				done = true;
1293 			if (!done) {
1294 				offset = qh->offset;
1295 				length = urb->transfer_buffer_length - offset;
1296 				transfer_pending = true;
1297 			}
1298 		}
1299 	}
1300 
1301 	/* urb->status != -EINPROGRESS means request has been faulted,
1302 	 * so we must abort this transfer after cleanup
1303 	 */
1304 	if (urb->status != -EINPROGRESS) {
1305 		done = true;
1306 		if (status == 0)
1307 			status = urb->status;
1308 	}
1309 
1310 	if (done) {
1311 		/* set status */
1312 		urb->status = status;
1313 		urb->actual_length = qh->offset;
1314 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_OUT);
1315 		return;
1316 	} else if ((usb_pipeisoc(pipe) || transfer_pending) && dma) {
1317 		if (musb_tx_dma_program(musb->dma_controller, hw_ep, qh, urb,
1318 				offset, length)) {
1319 			if (is_cppi_enabled() || tusb_dma_omap())
1320 				musb_h_tx_dma_start(hw_ep);
1321 			return;
1322 		}
1323 	} else	if (tx_csr & MUSB_TXCSR_DMAENAB) {
1324 		DBG(1, "not complete, but DMA enabled?\n");
1325 		return;
1326 	}
1327 
1328 	/*
1329 	 * PIO: start next packet in this URB.
1330 	 *
1331 	 * REVISIT: some docs say that when hw_ep->tx_double_buffered,
1332 	 * (and presumably, FIFO is not half-full) we should write *two*
1333 	 * packets before updating TXCSR; other docs disagree...
1334 	 */
1335 	if (length > qh->maxpacket)
1336 		length = qh->maxpacket;
1337 	/* Unmap the buffer so that CPU can use it */
1338 	usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1339 	musb_write_fifo(hw_ep, length, urb->transfer_buffer + offset);
1340 	qh->segsize = length;
1341 
1342 	musb_ep_select(mbase, epnum);
1343 	musb_writew(epio, MUSB_TXCSR,
1344 			MUSB_TXCSR_H_WZC_BITS | MUSB_TXCSR_TXPKTRDY);
1345 }
1346 
1347 
1348 #ifdef CONFIG_USB_INVENTRA_DMA
1349 
1350 /* Host side RX (IN) using Mentor DMA works as follows:
1351 	submit_urb ->
1352 		- if queue was empty, ProgramEndpoint
1353 		- first IN token is sent out (by setting ReqPkt)
1354 	LinuxIsr -> RxReady()
1355 	/\	=> first packet is received
1356 	|	- Set in mode 0 (DmaEnab, ~ReqPkt)
1357 	|		-> DMA Isr (transfer complete) -> RxReady()
1358 	|		    - Ack receive (~RxPktRdy), turn off DMA (~DmaEnab)
1359 	|		    - if urb not complete, send next IN token (ReqPkt)
1360 	|			   |		else complete urb.
1361 	|			   |
1362 	---------------------------
1363  *
1364  * Nuances of mode 1:
1365  *	For short packets, no ack (+RxPktRdy) is sent automatically
1366  *	(even if AutoClear is ON)
1367  *	For full packets, ack (~RxPktRdy) and next IN token (+ReqPkt) is sent
1368  *	automatically => major problem, as collecting the next packet becomes
1369  *	difficult. Hence mode 1 is not used.
1370  *
1371  * REVISIT
1372  *	All we care about at this driver level is that
1373  *       (a) all URBs terminate with REQPKT cleared and fifo(s) empty;
1374  *       (b) termination conditions are: short RX, or buffer full;
1375  *       (c) fault modes include
1376  *           - iff URB_SHORT_NOT_OK, short RX status is -EREMOTEIO.
1377  *             (and that endpoint's dma queue stops immediately)
1378  *           - overflow (full, PLUS more bytes in the terminal packet)
1379  *
1380  *	So for example, usb-storage sets URB_SHORT_NOT_OK, and would
1381  *	thus be a great candidate for using mode 1 ... for all but the
1382  *	last packet of one URB's transfer.
1383  */
1384 
1385 #endif
1386 
1387 /* Schedule next QH from musb->in_bulk and move the current qh to
1388  * the end; avoids starvation for other endpoints.
1389  */
musb_bulk_rx_nak_timeout(struct musb * musb,struct musb_hw_ep * ep)1390 static void musb_bulk_rx_nak_timeout(struct musb *musb, struct musb_hw_ep *ep)
1391 {
1392 	struct dma_channel	*dma;
1393 	struct urb		*urb;
1394 	void __iomem		*mbase = musb->mregs;
1395 	void __iomem		*epio = ep->regs;
1396 	struct musb_qh		*cur_qh, *next_qh;
1397 	u16			rx_csr;
1398 
1399 	musb_ep_select(mbase, ep->epnum);
1400 	dma = is_dma_capable() ? ep->rx_channel : NULL;
1401 
1402 	/* clear nak timeout bit */
1403 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1404 	rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1405 	rx_csr &= ~MUSB_RXCSR_DATAERROR;
1406 	musb_writew(epio, MUSB_RXCSR, rx_csr);
1407 
1408 	cur_qh = first_qh(&musb->in_bulk);
1409 	if (cur_qh) {
1410 		urb = next_urb(cur_qh);
1411 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1412 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1413 			musb->dma_controller->channel_abort(dma);
1414 			urb->actual_length += dma->actual_len;
1415 			dma->actual_len = 0L;
1416 		}
1417 		musb_save_toggle(cur_qh, 1, urb);
1418 
1419 		/* move cur_qh to end of queue */
1420 		list_move_tail(&cur_qh->ring, &musb->in_bulk);
1421 
1422 		/* get the next qh from musb->in_bulk */
1423 		next_qh = first_qh(&musb->in_bulk);
1424 
1425 		/* set rx_reinit and schedule the next qh */
1426 		ep->rx_reinit = 1;
1427 		musb_start_urb(musb, 1, next_qh);
1428 	}
1429 }
1430 
1431 /*
1432  * Service an RX interrupt for the given IN endpoint; docs cover bulk, iso,
1433  * and high-bandwidth IN transfer cases.
1434  */
musb_host_rx(struct musb * musb,u8 epnum)1435 void musb_host_rx(struct musb *musb, u8 epnum)
1436 {
1437 	struct urb		*urb;
1438 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1439 	void __iomem		*epio = hw_ep->regs;
1440 	struct musb_qh		*qh = hw_ep->in_qh;
1441 	size_t			xfer_len;
1442 	void __iomem		*mbase = musb->mregs;
1443 	int			pipe;
1444 	u16			rx_csr, val;
1445 	bool			iso_err = false;
1446 	bool			done = false;
1447 	u32			status;
1448 	struct dma_channel	*dma;
1449 
1450 	musb_ep_select(mbase, epnum);
1451 
1452 	urb = next_urb(qh);
1453 	dma = is_dma_capable() ? hw_ep->rx_channel : NULL;
1454 	status = 0;
1455 	xfer_len = 0;
1456 
1457 	rx_csr = musb_readw(epio, MUSB_RXCSR);
1458 	val = rx_csr;
1459 
1460 	if (unlikely(!urb)) {
1461 		/* REVISIT -- THIS SHOULD NEVER HAPPEN ... but, at least
1462 		 * usbtest #11 (unlinks) triggers it regularly, sometimes
1463 		 * with fifo full.  (Only with DMA??)
1464 		 */
1465 		DBG(3, "BOGUS RX%d ready, csr %04x, count %d\n", epnum, val,
1466 			musb_readw(epio, MUSB_RXCOUNT));
1467 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1468 		return;
1469 	}
1470 
1471 	pipe = urb->pipe;
1472 
1473 	DBG(5, "<== hw %d rxcsr %04x, urb actual %d (+dma %zu)\n",
1474 		epnum, rx_csr, urb->actual_length,
1475 		dma ? dma->actual_len : 0);
1476 
1477 	/* check for errors, concurrent stall & unlink is not really
1478 	 * handled yet! */
1479 	if (rx_csr & MUSB_RXCSR_H_RXSTALL) {
1480 		DBG(3, "RX end %d STALL\n", epnum);
1481 
1482 		/* stall; record URB status */
1483 		status = -EPIPE;
1484 
1485 	} else if (rx_csr & MUSB_RXCSR_H_ERROR) {
1486 		DBG(3, "end %d RX proto error\n", epnum);
1487 
1488 		status = -EPROTO;
1489 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1490 
1491 	} else if (rx_csr & MUSB_RXCSR_DATAERROR) {
1492 
1493 		if (USB_ENDPOINT_XFER_ISOC != qh->type) {
1494 			DBG(6, "RX end %d NAK timeout\n", epnum);
1495 
1496 			/* NOTE: NAKing is *NOT* an error, so we want to
1497 			 * continue.  Except ... if there's a request for
1498 			 * another QH, use that instead of starving it.
1499 			 *
1500 			 * Devices like Ethernet and serial adapters keep
1501 			 * reads posted at all times, which will starve
1502 			 * other devices without this logic.
1503 			 */
1504 			if (usb_pipebulk(urb->pipe)
1505 					&& qh->mux == 1
1506 					&& !list_is_singular(&musb->in_bulk)) {
1507 				musb_bulk_rx_nak_timeout(musb, hw_ep);
1508 				return;
1509 			}
1510 			musb_ep_select(mbase, epnum);
1511 			rx_csr |= MUSB_RXCSR_H_WZC_BITS;
1512 			rx_csr &= ~MUSB_RXCSR_DATAERROR;
1513 			musb_writew(epio, MUSB_RXCSR, rx_csr);
1514 
1515 			goto finish;
1516 		} else {
1517 			DBG(4, "RX end %d ISO data error\n", epnum);
1518 			/* packet error reported later */
1519 			iso_err = true;
1520 		}
1521 	} else if (rx_csr & MUSB_RXCSR_INCOMPRX) {
1522 		DBG(3, "end %d high bandwidth incomplete ISO packet RX\n",
1523 				epnum);
1524 		status = -EPROTO;
1525 	}
1526 
1527 	/* faults abort the transfer */
1528 	if (status) {
1529 		/* clean up dma and collect transfer count */
1530 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1531 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1532 			(void) musb->dma_controller->channel_abort(dma);
1533 			xfer_len = dma->actual_len;
1534 		}
1535 		musb_h_flush_rxfifo(hw_ep, MUSB_RXCSR_CLRDATATOG);
1536 		musb_writeb(epio, MUSB_RXINTERVAL, 0);
1537 		done = true;
1538 		goto finish;
1539 	}
1540 
1541 	if (unlikely(dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY)) {
1542 		/* SHOULD NEVER HAPPEN ... but at least DaVinci has done it */
1543 		ERR("RX%d dma busy, csr %04x\n", epnum, rx_csr);
1544 		goto finish;
1545 	}
1546 
1547 	/* thorough shutdown for now ... given more precise fault handling
1548 	 * and better queueing support, we might keep a DMA pipeline going
1549 	 * while processing this irq for earlier completions.
1550 	 */
1551 
1552 	/* FIXME this is _way_ too much in-line logic for Mentor DMA */
1553 
1554 #ifndef CONFIG_USB_INVENTRA_DMA
1555 	if (rx_csr & MUSB_RXCSR_H_REQPKT)  {
1556 		/* REVISIT this happened for a while on some short reads...
1557 		 * the cleanup still needs investigation... looks bad...
1558 		 * and also duplicates dma cleanup code above ... plus,
1559 		 * shouldn't this be the "half full" double buffer case?
1560 		 */
1561 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
1562 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
1563 			(void) musb->dma_controller->channel_abort(dma);
1564 			xfer_len = dma->actual_len;
1565 			done = true;
1566 		}
1567 
1568 		DBG(2, "RXCSR%d %04x, reqpkt, len %zu%s\n", epnum, rx_csr,
1569 				xfer_len, dma ? ", dma" : "");
1570 		rx_csr &= ~MUSB_RXCSR_H_REQPKT;
1571 
1572 		musb_ep_select(mbase, epnum);
1573 		musb_writew(epio, MUSB_RXCSR,
1574 				MUSB_RXCSR_H_WZC_BITS | rx_csr);
1575 	}
1576 #endif
1577 	if (dma && (rx_csr & MUSB_RXCSR_DMAENAB)) {
1578 		xfer_len = dma->actual_len;
1579 
1580 		val &= ~(MUSB_RXCSR_DMAENAB
1581 			| MUSB_RXCSR_H_AUTOREQ
1582 			| MUSB_RXCSR_AUTOCLEAR
1583 			| MUSB_RXCSR_RXPKTRDY);
1584 		musb_writew(hw_ep->regs, MUSB_RXCSR, val);
1585 
1586 #ifdef CONFIG_USB_INVENTRA_DMA
1587 		if (usb_pipeisoc(pipe)) {
1588 			struct usb_iso_packet_descriptor *d;
1589 
1590 			d = urb->iso_frame_desc + qh->iso_idx;
1591 			d->actual_length = xfer_len;
1592 
1593 			/* even if there was an error, we did the dma
1594 			 * for iso_frame_desc->length
1595 			 */
1596 			if (d->status != EILSEQ && d->status != -EOVERFLOW)
1597 				d->status = 0;
1598 
1599 			if (++qh->iso_idx >= urb->number_of_packets)
1600 				done = true;
1601 			else
1602 				done = false;
1603 
1604 		} else  {
1605 		/* done if urb buffer is full or short packet is recd */
1606 		done = (urb->actual_length + xfer_len >=
1607 				urb->transfer_buffer_length
1608 			|| dma->actual_len < qh->maxpacket);
1609 		}
1610 
1611 		/* send IN token for next packet, without AUTOREQ */
1612 		if (!done) {
1613 			val |= MUSB_RXCSR_H_REQPKT;
1614 			musb_writew(epio, MUSB_RXCSR,
1615 				MUSB_RXCSR_H_WZC_BITS | val);
1616 		}
1617 
1618 		DBG(4, "ep %d dma %s, rxcsr %04x, rxcount %d\n", epnum,
1619 			done ? "off" : "reset",
1620 			musb_readw(epio, MUSB_RXCSR),
1621 			musb_readw(epio, MUSB_RXCOUNT));
1622 #else
1623 		done = true;
1624 #endif
1625 	} else if (urb->status == -EINPROGRESS) {
1626 		/* if no errors, be sure a packet is ready for unloading */
1627 		if (unlikely(!(rx_csr & MUSB_RXCSR_RXPKTRDY))) {
1628 			status = -EPROTO;
1629 			ERR("Rx interrupt with no errors or packet!\n");
1630 
1631 			/* FIXME this is another "SHOULD NEVER HAPPEN" */
1632 
1633 /* SCRUB (RX) */
1634 			/* do the proper sequence to abort the transfer */
1635 			musb_ep_select(mbase, epnum);
1636 			val &= ~MUSB_RXCSR_H_REQPKT;
1637 			musb_writew(epio, MUSB_RXCSR, val);
1638 			goto finish;
1639 		}
1640 
1641 		/* we are expecting IN packets */
1642 #ifdef CONFIG_USB_INVENTRA_DMA
1643 		if (dma) {
1644 			struct dma_controller	*c;
1645 			u16			rx_count;
1646 			int			ret, length;
1647 			dma_addr_t		buf;
1648 
1649 			rx_count = musb_readw(epio, MUSB_RXCOUNT);
1650 
1651 			DBG(2, "RX%d count %d, buffer 0x%x len %d/%d\n",
1652 					epnum, rx_count,
1653 					urb->transfer_dma
1654 						+ urb->actual_length,
1655 					qh->offset,
1656 					urb->transfer_buffer_length);
1657 
1658 			c = musb->dma_controller;
1659 
1660 			if (usb_pipeisoc(pipe)) {
1661 				int d_status = 0;
1662 				struct usb_iso_packet_descriptor *d;
1663 
1664 				d = urb->iso_frame_desc + qh->iso_idx;
1665 
1666 				if (iso_err) {
1667 					d_status = -EILSEQ;
1668 					urb->error_count++;
1669 				}
1670 				if (rx_count > d->length) {
1671 					if (d_status == 0) {
1672 						d_status = -EOVERFLOW;
1673 						urb->error_count++;
1674 					}
1675 					DBG(2, "** OVERFLOW %d into %d\n",\
1676 					    rx_count, d->length);
1677 
1678 					length = d->length;
1679 				} else
1680 					length = rx_count;
1681 				d->status = d_status;
1682 				buf = urb->transfer_dma + d->offset;
1683 			} else {
1684 				length = rx_count;
1685 				buf = urb->transfer_dma +
1686 						urb->actual_length;
1687 			}
1688 
1689 			dma->desired_mode = 0;
1690 #ifdef USE_MODE1
1691 			/* because of the issue below, mode 1 will
1692 			 * only rarely behave with correct semantics.
1693 			 */
1694 			if ((urb->transfer_flags &
1695 						URB_SHORT_NOT_OK)
1696 				&& (urb->transfer_buffer_length -
1697 						urb->actual_length)
1698 					> qh->maxpacket)
1699 				dma->desired_mode = 1;
1700 			if (rx_count < hw_ep->max_packet_sz_rx) {
1701 				length = rx_count;
1702 				dma->desired_mode = 0;
1703 			} else {
1704 				length = urb->transfer_buffer_length;
1705 			}
1706 #endif
1707 
1708 /* Disadvantage of using mode 1:
1709  *	It's basically usable only for mass storage class; essentially all
1710  *	other protocols also terminate transfers on short packets.
1711  *
1712  * Details:
1713  *	An extra IN token is sent at the end of the transfer (due to AUTOREQ)
1714  *	If you try to use mode 1 for (transfer_buffer_length - 512), and try
1715  *	to use the extra IN token to grab the last packet using mode 0, then
1716  *	the problem is that you cannot be sure when the device will send the
1717  *	last packet and RxPktRdy set. Sometimes the packet is recd too soon
1718  *	such that it gets lost when RxCSR is re-set at the end of the mode 1
1719  *	transfer, while sometimes it is recd just a little late so that if you
1720  *	try to configure for mode 0 soon after the mode 1 transfer is
1721  *	completed, you will find rxcount 0. Okay, so you might think why not
1722  *	wait for an interrupt when the pkt is recd. Well, you won't get any!
1723  */
1724 
1725 			val = musb_readw(epio, MUSB_RXCSR);
1726 			val &= ~MUSB_RXCSR_H_REQPKT;
1727 
1728 			if (dma->desired_mode == 0)
1729 				val &= ~MUSB_RXCSR_H_AUTOREQ;
1730 			else
1731 				val |= MUSB_RXCSR_H_AUTOREQ;
1732 			val |= MUSB_RXCSR_DMAENAB;
1733 
1734 			/* autoclear shouldn't be set in high bandwidth */
1735 			if (qh->hb_mult == 1)
1736 				val |= MUSB_RXCSR_AUTOCLEAR;
1737 
1738 			musb_writew(epio, MUSB_RXCSR,
1739 				MUSB_RXCSR_H_WZC_BITS | val);
1740 
1741 			/* REVISIT if when actual_length != 0,
1742 			 * transfer_buffer_length needs to be
1743 			 * adjusted first...
1744 			 */
1745 			ret = c->channel_program(
1746 				dma, qh->maxpacket,
1747 				dma->desired_mode, buf, length);
1748 
1749 			if (!ret) {
1750 				c->channel_release(dma);
1751 				hw_ep->rx_channel = NULL;
1752 				dma = NULL;
1753 				/* REVISIT reset CSR */
1754 			}
1755 		}
1756 #endif	/* Mentor DMA */
1757 
1758 		if (!dma) {
1759 			/* Unmap the buffer so that CPU can use it */
1760 			usb_hcd_unmap_urb_for_dma(musb_to_hcd(musb), urb);
1761 			done = musb_host_packet_rx(musb, urb,
1762 					epnum, iso_err);
1763 			DBG(6, "read %spacket\n", done ? "last " : "");
1764 		}
1765 	}
1766 
1767 finish:
1768 	urb->actual_length += xfer_len;
1769 	qh->offset += xfer_len;
1770 	if (done) {
1771 		if (urb->status == -EINPROGRESS)
1772 			urb->status = status;
1773 		musb_advance_schedule(musb, urb, hw_ep, USB_DIR_IN);
1774 	}
1775 }
1776 
1777 /* schedule nodes correspond to peripheral endpoints, like an OHCI QH.
1778  * the software schedule associates multiple such nodes with a given
1779  * host side hardware endpoint + direction; scheduling may activate
1780  * that hardware endpoint.
1781  */
musb_schedule(struct musb * musb,struct musb_qh * qh,int is_in)1782 static int musb_schedule(
1783 	struct musb		*musb,
1784 	struct musb_qh		*qh,
1785 	int			is_in)
1786 {
1787 	int			idle;
1788 	int			best_diff;
1789 	int			best_end, epnum;
1790 	struct musb_hw_ep	*hw_ep = NULL;
1791 	struct list_head	*head = NULL;
1792 	u8			toggle;
1793 	u8			txtype;
1794 	struct urb		*urb = next_urb(qh);
1795 
1796 	/* use fixed hardware for control and bulk */
1797 	if (qh->type == USB_ENDPOINT_XFER_CONTROL) {
1798 		head = &musb->control;
1799 		hw_ep = musb->control_ep;
1800 		goto success;
1801 	}
1802 
1803 	/* else, periodic transfers get muxed to other endpoints */
1804 
1805 	/*
1806 	 * We know this qh hasn't been scheduled, so all we need to do
1807 	 * is choose which hardware endpoint to put it on ...
1808 	 *
1809 	 * REVISIT what we really want here is a regular schedule tree
1810 	 * like e.g. OHCI uses.
1811 	 */
1812 	best_diff = 4096;
1813 	best_end = -1;
1814 
1815 	for (epnum = 1, hw_ep = musb->endpoints + 1;
1816 			epnum < musb->nr_endpoints;
1817 			epnum++, hw_ep++) {
1818 		int	diff;
1819 
1820 		if (musb_ep_get_qh(hw_ep, is_in) != NULL)
1821 			continue;
1822 
1823 		if (hw_ep == musb->bulk_ep)
1824 			continue;
1825 
1826 		if (is_in)
1827 			diff = hw_ep->max_packet_sz_rx;
1828 		else
1829 			diff = hw_ep->max_packet_sz_tx;
1830 		diff -= (qh->maxpacket * qh->hb_mult);
1831 
1832 		if (diff >= 0 && best_diff > diff) {
1833 
1834 			/*
1835 			 * Mentor controller has a bug in that if we schedule
1836 			 * a BULK Tx transfer on an endpoint that had earlier
1837 			 * handled ISOC then the BULK transfer has to start on
1838 			 * a zero toggle.  If the BULK transfer starts on a 1
1839 			 * toggle then this transfer will fail as the mentor
1840 			 * controller starts the Bulk transfer on a 0 toggle
1841 			 * irrespective of the programming of the toggle bits
1842 			 * in the TXCSR register.  Check for this condition
1843 			 * while allocating the EP for a Tx Bulk transfer.  If
1844 			 * so skip this EP.
1845 			 */
1846 			hw_ep = musb->endpoints + epnum;
1847 			toggle = usb_gettoggle(urb->dev, qh->epnum, !is_in);
1848 			txtype = (musb_readb(hw_ep->regs, MUSB_TXTYPE)
1849 					>> 4) & 0x3;
1850 			if (!is_in && (qh->type == USB_ENDPOINT_XFER_BULK) &&
1851 				toggle && (txtype == USB_ENDPOINT_XFER_ISOC))
1852 				continue;
1853 
1854 			best_diff = diff;
1855 			best_end = epnum;
1856 		}
1857 	}
1858 	/* use bulk reserved ep1 if no other ep is free */
1859 	if (best_end < 0 && qh->type == USB_ENDPOINT_XFER_BULK) {
1860 		hw_ep = musb->bulk_ep;
1861 		if (is_in)
1862 			head = &musb->in_bulk;
1863 		else
1864 			head = &musb->out_bulk;
1865 
1866 		/* Enable bulk RX NAK timeout scheme when bulk requests are
1867 		 * multiplexed.  This scheme doen't work in high speed to full
1868 		 * speed scenario as NAK interrupts are not coming from a
1869 		 * full speed device connected to a high speed device.
1870 		 * NAK timeout interval is 8 (128 uframe or 16ms) for HS and
1871 		 * 4 (8 frame or 8ms) for FS device.
1872 		 */
1873 		if (is_in && qh->dev)
1874 			qh->intv_reg =
1875 				(USB_SPEED_HIGH == qh->dev->speed) ? 8 : 4;
1876 		goto success;
1877 	} else if (best_end < 0) {
1878 		return -ENOSPC;
1879 	}
1880 
1881 	idle = 1;
1882 	qh->mux = 0;
1883 	hw_ep = musb->endpoints + best_end;
1884 	DBG(4, "qh %p periodic slot %d\n", qh, best_end);
1885 success:
1886 	if (head) {
1887 		idle = list_empty(head);
1888 		list_add_tail(&qh->ring, head);
1889 		qh->mux = 1;
1890 	}
1891 	qh->hw_ep = hw_ep;
1892 	qh->hep->hcpriv = qh;
1893 	if (idle)
1894 		musb_start_urb(musb, is_in, qh);
1895 	return 0;
1896 }
1897 
musb_urb_enqueue(struct usb_hcd * hcd,struct urb * urb,gfp_t mem_flags)1898 static int musb_urb_enqueue(
1899 	struct usb_hcd			*hcd,
1900 	struct urb			*urb,
1901 	gfp_t				mem_flags)
1902 {
1903 	unsigned long			flags;
1904 	struct musb			*musb = hcd_to_musb(hcd);
1905 	struct usb_host_endpoint	*hep = urb->ep;
1906 	struct musb_qh			*qh;
1907 	struct usb_endpoint_descriptor	*epd = &hep->desc;
1908 	int				ret;
1909 	unsigned			type_reg;
1910 	unsigned			interval;
1911 
1912 	/* host role must be active */
1913 	if (!is_host_active(musb) || !musb->is_active)
1914 		return -ENODEV;
1915 
1916 	spin_lock_irqsave(&musb->lock, flags);
1917 	ret = usb_hcd_link_urb_to_ep(hcd, urb);
1918 	qh = ret ? NULL : hep->hcpriv;
1919 	if (qh)
1920 		urb->hcpriv = qh;
1921 	spin_unlock_irqrestore(&musb->lock, flags);
1922 
1923 	/* DMA mapping was already done, if needed, and this urb is on
1924 	 * hep->urb_list now ... so we're done, unless hep wasn't yet
1925 	 * scheduled onto a live qh.
1926 	 *
1927 	 * REVISIT best to keep hep->hcpriv valid until the endpoint gets
1928 	 * disabled, testing for empty qh->ring and avoiding qh setup costs
1929 	 * except for the first urb queued after a config change.
1930 	 */
1931 	if (qh || ret)
1932 		return ret;
1933 
1934 	/* Allocate and initialize qh, minimizing the work done each time
1935 	 * hw_ep gets reprogrammed, or with irqs blocked.  Then schedule it.
1936 	 *
1937 	 * REVISIT consider a dedicated qh kmem_cache, so it's harder
1938 	 * for bugs in other kernel code to break this driver...
1939 	 */
1940 	qh = kzalloc(sizeof *qh, mem_flags);
1941 	if (!qh) {
1942 		spin_lock_irqsave(&musb->lock, flags);
1943 		usb_hcd_unlink_urb_from_ep(hcd, urb);
1944 		spin_unlock_irqrestore(&musb->lock, flags);
1945 		return -ENOMEM;
1946 	}
1947 
1948 	qh->hep = hep;
1949 	qh->dev = urb->dev;
1950 	INIT_LIST_HEAD(&qh->ring);
1951 	qh->is_ready = 1;
1952 
1953 	qh->maxpacket = le16_to_cpu(epd->wMaxPacketSize);
1954 	qh->type = usb_endpoint_type(epd);
1955 
1956 	/* Bits 11 & 12 of wMaxPacketSize encode high bandwidth multiplier.
1957 	 * Some musb cores don't support high bandwidth ISO transfers; and
1958 	 * we don't (yet!) support high bandwidth interrupt transfers.
1959 	 */
1960 	qh->hb_mult = 1 + ((qh->maxpacket >> 11) & 0x03);
1961 	if (qh->hb_mult > 1) {
1962 		int ok = (qh->type == USB_ENDPOINT_XFER_ISOC);
1963 
1964 		if (ok)
1965 			ok = (usb_pipein(urb->pipe) && musb->hb_iso_rx)
1966 				|| (usb_pipeout(urb->pipe) && musb->hb_iso_tx);
1967 		if (!ok) {
1968 			ret = -EMSGSIZE;
1969 			goto done;
1970 		}
1971 		qh->maxpacket &= 0x7ff;
1972 	}
1973 
1974 	qh->epnum = usb_endpoint_num(epd);
1975 
1976 	/* NOTE: urb->dev->devnum is wrong during SET_ADDRESS */
1977 	qh->addr_reg = (u8) usb_pipedevice(urb->pipe);
1978 
1979 	/* precompute rxtype/txtype/type0 register */
1980 	type_reg = (qh->type << 4) | qh->epnum;
1981 	switch (urb->dev->speed) {
1982 	case USB_SPEED_LOW:
1983 		type_reg |= 0xc0;
1984 		break;
1985 	case USB_SPEED_FULL:
1986 		type_reg |= 0x80;
1987 		break;
1988 	default:
1989 		type_reg |= 0x40;
1990 	}
1991 	qh->type_reg = type_reg;
1992 
1993 	/* Precompute RXINTERVAL/TXINTERVAL register */
1994 	switch (qh->type) {
1995 	case USB_ENDPOINT_XFER_INT:
1996 		/*
1997 		 * Full/low speeds use the  linear encoding,
1998 		 * high speed uses the logarithmic encoding.
1999 		 */
2000 		if (urb->dev->speed <= USB_SPEED_FULL) {
2001 			interval = max_t(u8, epd->bInterval, 1);
2002 			break;
2003 		}
2004 		/* FALLTHROUGH */
2005 	case USB_ENDPOINT_XFER_ISOC:
2006 		/* ISO always uses logarithmic encoding */
2007 		interval = min_t(u8, epd->bInterval, 16);
2008 		break;
2009 	default:
2010 		/* REVISIT we actually want to use NAK limits, hinting to the
2011 		 * transfer scheduling logic to try some other qh, e.g. try
2012 		 * for 2 msec first:
2013 		 *
2014 		 * interval = (USB_SPEED_HIGH == urb->dev->speed) ? 16 : 2;
2015 		 *
2016 		 * The downside of disabling this is that transfer scheduling
2017 		 * gets VERY unfair for nonperiodic transfers; a misbehaving
2018 		 * peripheral could make that hurt.  That's perfectly normal
2019 		 * for reads from network or serial adapters ... so we have
2020 		 * partial NAKlimit support for bulk RX.
2021 		 *
2022 		 * The upside of disabling it is simpler transfer scheduling.
2023 		 */
2024 		interval = 0;
2025 	}
2026 	qh->intv_reg = interval;
2027 
2028 	/* precompute addressing for external hub/tt ports */
2029 	if (musb->is_multipoint) {
2030 		struct usb_device	*parent = urb->dev->parent;
2031 
2032 		if (parent != hcd->self.root_hub) {
2033 			qh->h_addr_reg = (u8) parent->devnum;
2034 
2035 			/* set up tt info if needed */
2036 			if (urb->dev->tt) {
2037 				qh->h_port_reg = (u8) urb->dev->ttport;
2038 				if (urb->dev->tt->hub)
2039 					qh->h_addr_reg =
2040 						(u8) urb->dev->tt->hub->devnum;
2041 				if (urb->dev->tt->multi)
2042 					qh->h_addr_reg |= 0x80;
2043 			}
2044 		}
2045 	}
2046 
2047 	/* invariant: hep->hcpriv is null OR the qh that's already scheduled.
2048 	 * until we get real dma queues (with an entry for each urb/buffer),
2049 	 * we only have work to do in the former case.
2050 	 */
2051 	spin_lock_irqsave(&musb->lock, flags);
2052 	if (hep->hcpriv) {
2053 		/* some concurrent activity submitted another urb to hep...
2054 		 * odd, rare, error prone, but legal.
2055 		 */
2056 		kfree(qh);
2057 		qh = NULL;
2058 		ret = 0;
2059 	} else
2060 		ret = musb_schedule(musb, qh,
2061 				epd->bEndpointAddress & USB_ENDPOINT_DIR_MASK);
2062 
2063 	if (ret == 0) {
2064 		urb->hcpriv = qh;
2065 		/* FIXME set urb->start_frame for iso/intr, it's tested in
2066 		 * musb_start_urb(), but otherwise only konicawc cares ...
2067 		 */
2068 	}
2069 	spin_unlock_irqrestore(&musb->lock, flags);
2070 
2071 done:
2072 	if (ret != 0) {
2073 		spin_lock_irqsave(&musb->lock, flags);
2074 		usb_hcd_unlink_urb_from_ep(hcd, urb);
2075 		spin_unlock_irqrestore(&musb->lock, flags);
2076 		kfree(qh);
2077 	}
2078 	return ret;
2079 }
2080 
2081 
2082 /*
2083  * abort a transfer that's at the head of a hardware queue.
2084  * called with controller locked, irqs blocked
2085  * that hardware queue advances to the next transfer, unless prevented
2086  */
musb_cleanup_urb(struct urb * urb,struct musb_qh * qh)2087 static int musb_cleanup_urb(struct urb *urb, struct musb_qh *qh)
2088 {
2089 	struct musb_hw_ep	*ep = qh->hw_ep;
2090 	void __iomem		*epio = ep->regs;
2091 	unsigned		hw_end = ep->epnum;
2092 	void __iomem		*regs = ep->musb->mregs;
2093 	int			is_in = usb_pipein(urb->pipe);
2094 	int			status = 0;
2095 	u16			csr;
2096 
2097 	musb_ep_select(regs, hw_end);
2098 
2099 	if (is_dma_capable()) {
2100 		struct dma_channel	*dma;
2101 
2102 		dma = is_in ? ep->rx_channel : ep->tx_channel;
2103 		if (dma) {
2104 			status = ep->musb->dma_controller->channel_abort(dma);
2105 			DBG(status ? 1 : 3,
2106 				"abort %cX%d DMA for urb %p --> %d\n",
2107 				is_in ? 'R' : 'T', ep->epnum,
2108 				urb, status);
2109 			urb->actual_length += dma->actual_len;
2110 		}
2111 	}
2112 
2113 	/* turn off DMA requests, discard state, stop polling ... */
2114 	if (is_in) {
2115 		/* giveback saves bulk toggle */
2116 		csr = musb_h_flush_rxfifo(ep, 0);
2117 
2118 		/* REVISIT we still get an irq; should likely clear the
2119 		 * endpoint's irq status here to avoid bogus irqs.
2120 		 * clearing that status is platform-specific...
2121 		 */
2122 	} else if (ep->epnum) {
2123 		musb_h_tx_flush_fifo(ep);
2124 		csr = musb_readw(epio, MUSB_TXCSR);
2125 		csr &= ~(MUSB_TXCSR_AUTOSET
2126 			| MUSB_TXCSR_DMAENAB
2127 			| MUSB_TXCSR_H_RXSTALL
2128 			| MUSB_TXCSR_H_NAKTIMEOUT
2129 			| MUSB_TXCSR_H_ERROR
2130 			| MUSB_TXCSR_TXPKTRDY);
2131 		musb_writew(epio, MUSB_TXCSR, csr);
2132 		/* REVISIT may need to clear FLUSHFIFO ... */
2133 		musb_writew(epio, MUSB_TXCSR, csr);
2134 		/* flush cpu writebuffer */
2135 		csr = musb_readw(epio, MUSB_TXCSR);
2136 	} else  {
2137 		musb_h_ep0_flush_fifo(ep);
2138 	}
2139 	if (status == 0)
2140 		musb_advance_schedule(ep->musb, urb, ep, is_in);
2141 	return status;
2142 }
2143 
musb_urb_dequeue(struct usb_hcd * hcd,struct urb * urb,int status)2144 static int musb_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
2145 {
2146 	struct musb		*musb = hcd_to_musb(hcd);
2147 	struct musb_qh		*qh;
2148 	unsigned long		flags;
2149 	int			is_in  = usb_pipein(urb->pipe);
2150 	int			ret;
2151 
2152 	DBG(4, "urb=%p, dev%d ep%d%s\n", urb,
2153 			usb_pipedevice(urb->pipe),
2154 			usb_pipeendpoint(urb->pipe),
2155 			is_in ? "in" : "out");
2156 
2157 	spin_lock_irqsave(&musb->lock, flags);
2158 	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
2159 	if (ret)
2160 		goto done;
2161 
2162 	qh = urb->hcpriv;
2163 	if (!qh)
2164 		goto done;
2165 
2166 	/*
2167 	 * Any URB not actively programmed into endpoint hardware can be
2168 	 * immediately given back; that's any URB not at the head of an
2169 	 * endpoint queue, unless someday we get real DMA queues.  And even
2170 	 * if it's at the head, it might not be known to the hardware...
2171 	 *
2172 	 * Otherwise abort current transfer, pending DMA, etc.; urb->status
2173 	 * has already been updated.  This is a synchronous abort; it'd be
2174 	 * OK to hold off until after some IRQ, though.
2175 	 *
2176 	 * NOTE: qh is invalid unless !list_empty(&hep->urb_list)
2177 	 */
2178 	if (!qh->is_ready
2179 			|| urb->urb_list.prev != &qh->hep->urb_list
2180 			|| musb_ep_get_qh(qh->hw_ep, is_in) != qh) {
2181 		int	ready = qh->is_ready;
2182 
2183 		qh->is_ready = 0;
2184 		musb_giveback(musb, urb, 0);
2185 		qh->is_ready = ready;
2186 
2187 		/* If nothing else (usually musb_giveback) is using it
2188 		 * and its URB list has emptied, recycle this qh.
2189 		 */
2190 		if (ready && list_empty(&qh->hep->urb_list)) {
2191 			qh->hep->hcpriv = NULL;
2192 			list_del(&qh->ring);
2193 			kfree(qh);
2194 		}
2195 	} else
2196 		ret = musb_cleanup_urb(urb, qh);
2197 done:
2198 	spin_unlock_irqrestore(&musb->lock, flags);
2199 	return ret;
2200 }
2201 
2202 /* disable an endpoint */
2203 static void
musb_h_disable(struct usb_hcd * hcd,struct usb_host_endpoint * hep)2204 musb_h_disable(struct usb_hcd *hcd, struct usb_host_endpoint *hep)
2205 {
2206 	u8			is_in = hep->desc.bEndpointAddress & USB_DIR_IN;
2207 	unsigned long		flags;
2208 	struct musb		*musb = hcd_to_musb(hcd);
2209 	struct musb_qh		*qh;
2210 	struct urb		*urb;
2211 
2212 	spin_lock_irqsave(&musb->lock, flags);
2213 
2214 	qh = hep->hcpriv;
2215 	if (qh == NULL)
2216 		goto exit;
2217 
2218 	/* NOTE: qh is invalid unless !list_empty(&hep->urb_list) */
2219 
2220 	/* Kick the first URB off the hardware, if needed */
2221 	qh->is_ready = 0;
2222 	if (musb_ep_get_qh(qh->hw_ep, is_in) == qh) {
2223 		urb = next_urb(qh);
2224 
2225 		/* make software (then hardware) stop ASAP */
2226 		if (!urb->unlinked)
2227 			urb->status = -ESHUTDOWN;
2228 
2229 		/* cleanup */
2230 		musb_cleanup_urb(urb, qh);
2231 
2232 		/* Then nuke all the others ... and advance the
2233 		 * queue on hw_ep (e.g. bulk ring) when we're done.
2234 		 */
2235 		while (!list_empty(&hep->urb_list)) {
2236 			urb = next_urb(qh);
2237 			urb->status = -ESHUTDOWN;
2238 			musb_advance_schedule(musb, urb, qh->hw_ep, is_in);
2239 		}
2240 	} else {
2241 		/* Just empty the queue; the hardware is busy with
2242 		 * other transfers, and since !qh->is_ready nothing
2243 		 * will activate any of these as it advances.
2244 		 */
2245 		while (!list_empty(&hep->urb_list))
2246 			musb_giveback(musb, next_urb(qh), -ESHUTDOWN);
2247 
2248 		hep->hcpriv = NULL;
2249 		list_del(&qh->ring);
2250 		kfree(qh);
2251 	}
2252 exit:
2253 	spin_unlock_irqrestore(&musb->lock, flags);
2254 }
2255 
musb_h_get_frame_number(struct usb_hcd * hcd)2256 static int musb_h_get_frame_number(struct usb_hcd *hcd)
2257 {
2258 	struct musb	*musb = hcd_to_musb(hcd);
2259 
2260 	return musb_readw(musb->mregs, MUSB_FRAME);
2261 }
2262 
musb_h_start(struct usb_hcd * hcd)2263 static int musb_h_start(struct usb_hcd *hcd)
2264 {
2265 	struct musb	*musb = hcd_to_musb(hcd);
2266 
2267 	/* NOTE: musb_start() is called when the hub driver turns
2268 	 * on port power, or when (OTG) peripheral starts.
2269 	 */
2270 	hcd->state = HC_STATE_RUNNING;
2271 	musb->port1_status = 0;
2272 	return 0;
2273 }
2274 
musb_h_stop(struct usb_hcd * hcd)2275 static void musb_h_stop(struct usb_hcd *hcd)
2276 {
2277 	musb_stop(hcd_to_musb(hcd));
2278 	hcd->state = HC_STATE_HALT;
2279 }
2280 
musb_bus_suspend(struct usb_hcd * hcd)2281 static int musb_bus_suspend(struct usb_hcd *hcd)
2282 {
2283 	struct musb	*musb = hcd_to_musb(hcd);
2284 	u8		devctl;
2285 
2286 	if (!is_host_active(musb))
2287 		return 0;
2288 
2289 	switch (musb->xceiv->state) {
2290 	case OTG_STATE_A_SUSPEND:
2291 		return 0;
2292 	case OTG_STATE_A_WAIT_VRISE:
2293 		/* ID could be grounded even if there's no device
2294 		 * on the other end of the cable.  NOTE that the
2295 		 * A_WAIT_VRISE timers are messy with MUSB...
2296 		 */
2297 		devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2298 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2299 			musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2300 		break;
2301 	default:
2302 		break;
2303 	}
2304 
2305 	if (musb->is_active) {
2306 		WARNING("trying to suspend as %s while active\n",
2307 				otg_state_string(musb));
2308 		return -EBUSY;
2309 	} else
2310 		return 0;
2311 }
2312 
musb_bus_resume(struct usb_hcd * hcd)2313 static int musb_bus_resume(struct usb_hcd *hcd)
2314 {
2315 	/* resuming child port does the work */
2316 	return 0;
2317 }
2318 
2319 const struct hc_driver musb_hc_driver = {
2320 	.description		= "musb-hcd",
2321 	.product_desc		= "MUSB HDRC host driver",
2322 	.hcd_priv_size		= sizeof(struct musb),
2323 	.flags			= HCD_USB2 | HCD_MEMORY,
2324 
2325 	/* not using irq handler or reset hooks from usbcore, since
2326 	 * those must be shared with peripheral code for OTG configs
2327 	 */
2328 
2329 	.start			= musb_h_start,
2330 	.stop			= musb_h_stop,
2331 
2332 	.get_frame_number	= musb_h_get_frame_number,
2333 
2334 	.urb_enqueue		= musb_urb_enqueue,
2335 	.urb_dequeue		= musb_urb_dequeue,
2336 	.endpoint_disable	= musb_h_disable,
2337 
2338 	.hub_status_data	= musb_hub_status_data,
2339 	.hub_control		= musb_hub_control,
2340 	.bus_suspend		= musb_bus_suspend,
2341 	.bus_resume		= musb_bus_resume,
2342 	/* .start_port_reset	= NULL, */
2343 	/* .hub_irq_enable	= NULL, */
2344 };
2345