xref: /openbmc/linux/drivers/usb/musb/musb_gadget.c (revision 9ac8d3fb)
1 /*
2  * MUSB OTG driver peripheral support
3  *
4  * Copyright 2005 Mentor Graphics Corporation
5  * Copyright (C) 2005-2006 by Texas Instruments
6  * Copyright (C) 2006-2007 Nokia Corporation
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License
10  * version 2 as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20  * 02110-1301 USA
21  *
22  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
23  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
25  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
28  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
29  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/list.h>
37 #include <linux/timer.h>
38 #include <linux/module.h>
39 #include <linux/smp.h>
40 #include <linux/spinlock.h>
41 #include <linux/delay.h>
42 #include <linux/moduleparam.h>
43 #include <linux/stat.h>
44 #include <linux/dma-mapping.h>
45 
46 #include "musb_core.h"
47 
48 
49 /* MUSB PERIPHERAL status 3-mar-2006:
50  *
51  * - EP0 seems solid.  It passes both USBCV and usbtest control cases.
52  *   Minor glitches:
53  *
54  *     + remote wakeup to Linux hosts work, but saw USBCV failures;
55  *       in one test run (operator error?)
56  *     + endpoint halt tests -- in both usbtest and usbcv -- seem
57  *       to break when dma is enabled ... is something wrongly
58  *       clearing SENDSTALL?
59  *
60  * - Mass storage behaved ok when last tested.  Network traffic patterns
61  *   (with lots of short transfers etc) need retesting; they turn up the
62  *   worst cases of the DMA, since short packets are typical but are not
63  *   required.
64  *
65  * - TX/IN
66  *     + both pio and dma behave in with network and g_zero tests
67  *     + no cppi throughput issues other than no-hw-queueing
68  *     + failed with FLAT_REG (DaVinci)
69  *     + seems to behave with double buffering, PIO -and- CPPI
70  *     + with gadgetfs + AIO, requests got lost?
71  *
72  * - RX/OUT
73  *     + both pio and dma behave in with network and g_zero tests
74  *     + dma is slow in typical case (short_not_ok is clear)
75  *     + double buffering ok with PIO
76  *     + double buffering *FAILS* with CPPI, wrong data bytes sometimes
77  *     + request lossage observed with gadgetfs
78  *
79  * - ISO not tested ... might work, but only weakly isochronous
80  *
81  * - Gadget driver disabling of softconnect during bind() is ignored; so
82  *   drivers can't hold off host requests until userspace is ready.
83  *   (Workaround:  they can turn it off later.)
84  *
85  * - PORTABILITY (assumes PIO works):
86  *     + DaVinci, basically works with cppi dma
87  *     + OMAP 2430, ditto with mentor dma
88  *     + TUSB 6010, platform-specific dma in the works
89  */
90 
91 /* ----------------------------------------------------------------------- */
92 
93 /*
94  * Immediately complete a request.
95  *
96  * @param request the request to complete
97  * @param status the status to complete the request with
98  * Context: controller locked, IRQs blocked.
99  */
100 void musb_g_giveback(
101 	struct musb_ep		*ep,
102 	struct usb_request	*request,
103 	int			status)
104 __releases(ep->musb->lock)
105 __acquires(ep->musb->lock)
106 {
107 	struct musb_request	*req;
108 	struct musb		*musb;
109 	int			busy = ep->busy;
110 
111 	req = to_musb_request(request);
112 
113 	list_del(&request->list);
114 	if (req->request.status == -EINPROGRESS)
115 		req->request.status = status;
116 	musb = req->musb;
117 
118 	ep->busy = 1;
119 	spin_unlock(&musb->lock);
120 	if (is_dma_capable()) {
121 		if (req->mapped) {
122 			dma_unmap_single(musb->controller,
123 					req->request.dma,
124 					req->request.length,
125 					req->tx
126 						? DMA_TO_DEVICE
127 						: DMA_FROM_DEVICE);
128 			req->request.dma = DMA_ADDR_INVALID;
129 			req->mapped = 0;
130 		} else if (req->request.dma != DMA_ADDR_INVALID)
131 			dma_sync_single_for_cpu(musb->controller,
132 					req->request.dma,
133 					req->request.length,
134 					req->tx
135 						? DMA_TO_DEVICE
136 						: DMA_FROM_DEVICE);
137 	}
138 	if (request->status == 0)
139 		DBG(5, "%s done request %p,  %d/%d\n",
140 				ep->end_point.name, request,
141 				req->request.actual, req->request.length);
142 	else
143 		DBG(2, "%s request %p, %d/%d fault %d\n",
144 				ep->end_point.name, request,
145 				req->request.actual, req->request.length,
146 				request->status);
147 	req->request.complete(&req->ep->end_point, &req->request);
148 	spin_lock(&musb->lock);
149 	ep->busy = busy;
150 }
151 
152 /* ----------------------------------------------------------------------- */
153 
154 /*
155  * Abort requests queued to an endpoint using the status. Synchronous.
156  * caller locked controller and blocked irqs, and selected this ep.
157  */
158 static void nuke(struct musb_ep *ep, const int status)
159 {
160 	struct musb_request	*req = NULL;
161 	void __iomem *epio = ep->musb->endpoints[ep->current_epnum].regs;
162 
163 	ep->busy = 1;
164 
165 	if (is_dma_capable() && ep->dma) {
166 		struct dma_controller	*c = ep->musb->dma_controller;
167 		int value;
168 		if (ep->is_in) {
169 			musb_writew(epio, MUSB_TXCSR,
170 					0 | MUSB_TXCSR_FLUSHFIFO);
171 			musb_writew(epio, MUSB_TXCSR,
172 					0 | MUSB_TXCSR_FLUSHFIFO);
173 		} else {
174 			musb_writew(epio, MUSB_RXCSR,
175 					0 | MUSB_RXCSR_FLUSHFIFO);
176 			musb_writew(epio, MUSB_RXCSR,
177 					0 | MUSB_RXCSR_FLUSHFIFO);
178 		}
179 
180 		value = c->channel_abort(ep->dma);
181 		DBG(value ? 1 : 6, "%s: abort DMA --> %d\n", ep->name, value);
182 		c->channel_release(ep->dma);
183 		ep->dma = NULL;
184 	}
185 
186 	while (!list_empty(&(ep->req_list))) {
187 		req = container_of(ep->req_list.next, struct musb_request,
188 				request.list);
189 		musb_g_giveback(ep, &req->request, status);
190 	}
191 }
192 
193 /* ----------------------------------------------------------------------- */
194 
195 /* Data transfers - pure PIO, pure DMA, or mixed mode */
196 
197 /*
198  * This assumes the separate CPPI engine is responding to DMA requests
199  * from the usb core ... sequenced a bit differently from mentor dma.
200  */
201 
202 static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
203 {
204 	if (can_bulk_split(musb, ep->type))
205 		return ep->hw_ep->max_packet_sz_tx;
206 	else
207 		return ep->packet_sz;
208 }
209 
210 
211 #ifdef CONFIG_USB_INVENTRA_DMA
212 
213 /* Peripheral tx (IN) using Mentor DMA works as follows:
214 	Only mode 0 is used for transfers <= wPktSize,
215 	mode 1 is used for larger transfers,
216 
217 	One of the following happens:
218 	- Host sends IN token which causes an endpoint interrupt
219 		-> TxAvail
220 			-> if DMA is currently busy, exit.
221 			-> if queue is non-empty, txstate().
222 
223 	- Request is queued by the gadget driver.
224 		-> if queue was previously empty, txstate()
225 
226 	txstate()
227 		-> start
228 		  /\	-> setup DMA
229 		  |     (data is transferred to the FIFO, then sent out when
230 		  |	IN token(s) are recd from Host.
231 		  |		-> DMA interrupt on completion
232 		  |		   calls TxAvail.
233 		  |		      -> stop DMA, ~DmaEenab,
234 		  |		      -> set TxPktRdy for last short pkt or zlp
235 		  |		      -> Complete Request
236 		  |		      -> Continue next request (call txstate)
237 		  |___________________________________|
238 
239  * Non-Mentor DMA engines can of course work differently, such as by
240  * upleveling from irq-per-packet to irq-per-buffer.
241  */
242 
243 #endif
244 
245 /*
246  * An endpoint is transmitting data. This can be called either from
247  * the IRQ routine or from ep.queue() to kickstart a request on an
248  * endpoint.
249  *
250  * Context: controller locked, IRQs blocked, endpoint selected
251  */
252 static void txstate(struct musb *musb, struct musb_request *req)
253 {
254 	u8			epnum = req->epnum;
255 	struct musb_ep		*musb_ep;
256 	void __iomem		*epio = musb->endpoints[epnum].regs;
257 	struct usb_request	*request;
258 	u16			fifo_count = 0, csr;
259 	int			use_dma = 0;
260 
261 	musb_ep = req->ep;
262 
263 	/* we shouldn't get here while DMA is active ... but we do ... */
264 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
265 		DBG(4, "dma pending...\n");
266 		return;
267 	}
268 
269 	/* read TXCSR before */
270 	csr = musb_readw(epio, MUSB_TXCSR);
271 
272 	request = &req->request;
273 	fifo_count = min(max_ep_writesize(musb, musb_ep),
274 			(int)(request->length - request->actual));
275 
276 	if (csr & MUSB_TXCSR_TXPKTRDY) {
277 		DBG(5, "%s old packet still ready , txcsr %03x\n",
278 				musb_ep->end_point.name, csr);
279 		return;
280 	}
281 
282 	if (csr & MUSB_TXCSR_P_SENDSTALL) {
283 		DBG(5, "%s stalling, txcsr %03x\n",
284 				musb_ep->end_point.name, csr);
285 		return;
286 	}
287 
288 	DBG(4, "hw_ep%d, maxpacket %d, fifo count %d, txcsr %03x\n",
289 			epnum, musb_ep->packet_sz, fifo_count,
290 			csr);
291 
292 #ifndef	CONFIG_MUSB_PIO_ONLY
293 	if (is_dma_capable() && musb_ep->dma) {
294 		struct dma_controller	*c = musb->dma_controller;
295 
296 		use_dma = (request->dma != DMA_ADDR_INVALID);
297 
298 		/* MUSB_TXCSR_P_ISO is still set correctly */
299 
300 #ifdef CONFIG_USB_INVENTRA_DMA
301 		{
302 			size_t request_size;
303 
304 			/* setup DMA, then program endpoint CSR */
305 			request_size = min(request->length,
306 						musb_ep->dma->max_len);
307 			if (request_size <= musb_ep->packet_sz)
308 				musb_ep->dma->desired_mode = 0;
309 			else
310 				musb_ep->dma->desired_mode = 1;
311 
312 			use_dma = use_dma && c->channel_program(
313 					musb_ep->dma, musb_ep->packet_sz,
314 					musb_ep->dma->desired_mode,
315 					request->dma, request_size);
316 			if (use_dma) {
317 				if (musb_ep->dma->desired_mode == 0) {
318 					/* ASSERT: DMAENAB is clear */
319 					csr &= ~(MUSB_TXCSR_AUTOSET |
320 							MUSB_TXCSR_DMAMODE);
321 					csr |= (MUSB_TXCSR_DMAENAB |
322 							MUSB_TXCSR_MODE);
323 					/* against programming guide */
324 				} else
325 					csr |= (MUSB_TXCSR_AUTOSET
326 							| MUSB_TXCSR_DMAENAB
327 							| MUSB_TXCSR_DMAMODE
328 							| MUSB_TXCSR_MODE);
329 
330 				csr &= ~MUSB_TXCSR_P_UNDERRUN;
331 				musb_writew(epio, MUSB_TXCSR, csr);
332 			}
333 		}
334 
335 #elif defined(CONFIG_USB_TI_CPPI_DMA)
336 		/* program endpoint CSR first, then setup DMA */
337 		csr &= ~(MUSB_TXCSR_AUTOSET
338 				| MUSB_TXCSR_DMAMODE
339 				| MUSB_TXCSR_P_UNDERRUN
340 				| MUSB_TXCSR_TXPKTRDY);
341 		csr |= MUSB_TXCSR_MODE | MUSB_TXCSR_DMAENAB;
342 		musb_writew(epio, MUSB_TXCSR,
343 			(MUSB_TXCSR_P_WZC_BITS & ~MUSB_TXCSR_P_UNDERRUN)
344 				| csr);
345 
346 		/* ensure writebuffer is empty */
347 		csr = musb_readw(epio, MUSB_TXCSR);
348 
349 		/* NOTE host side sets DMAENAB later than this; both are
350 		 * OK since the transfer dma glue (between CPPI and Mentor
351 		 * fifos) just tells CPPI it could start.  Data only moves
352 		 * to the USB TX fifo when both fifos are ready.
353 		 */
354 
355 		/* "mode" is irrelevant here; handle terminating ZLPs like
356 		 * PIO does, since the hardware RNDIS mode seems unreliable
357 		 * except for the last-packet-is-already-short case.
358 		 */
359 		use_dma = use_dma && c->channel_program(
360 				musb_ep->dma, musb_ep->packet_sz,
361 				0,
362 				request->dma,
363 				request->length);
364 		if (!use_dma) {
365 			c->channel_release(musb_ep->dma);
366 			musb_ep->dma = NULL;
367 			/* ASSERT: DMAENAB clear */
368 			csr &= ~(MUSB_TXCSR_DMAMODE | MUSB_TXCSR_MODE);
369 			/* invariant: prequest->buf is non-null */
370 		}
371 #elif defined(CONFIG_USB_TUSB_OMAP_DMA)
372 		use_dma = use_dma && c->channel_program(
373 				musb_ep->dma, musb_ep->packet_sz,
374 				request->zero,
375 				request->dma,
376 				request->length);
377 #endif
378 	}
379 #endif
380 
381 	if (!use_dma) {
382 		musb_write_fifo(musb_ep->hw_ep, fifo_count,
383 				(u8 *) (request->buf + request->actual));
384 		request->actual += fifo_count;
385 		csr |= MUSB_TXCSR_TXPKTRDY;
386 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
387 		musb_writew(epio, MUSB_TXCSR, csr);
388 	}
389 
390 	/* host may already have the data when this message shows... */
391 	DBG(3, "%s TX/IN %s len %d/%d, txcsr %04x, fifo %d/%d\n",
392 			musb_ep->end_point.name, use_dma ? "dma" : "pio",
393 			request->actual, request->length,
394 			musb_readw(epio, MUSB_TXCSR),
395 			fifo_count,
396 			musb_readw(epio, MUSB_TXMAXP));
397 }
398 
399 /*
400  * FIFO state update (e.g. data ready).
401  * Called from IRQ,  with controller locked.
402  */
403 void musb_g_tx(struct musb *musb, u8 epnum)
404 {
405 	u16			csr;
406 	struct usb_request	*request;
407 	u8 __iomem		*mbase = musb->mregs;
408 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_in;
409 	void __iomem		*epio = musb->endpoints[epnum].regs;
410 	struct dma_channel	*dma;
411 
412 	musb_ep_select(mbase, epnum);
413 	request = next_request(musb_ep);
414 
415 	csr = musb_readw(epio, MUSB_TXCSR);
416 	DBG(4, "<== %s, txcsr %04x\n", musb_ep->end_point.name, csr);
417 
418 	dma = is_dma_capable() ? musb_ep->dma : NULL;
419 	do {
420 		/* REVISIT for high bandwidth, MUSB_TXCSR_P_INCOMPTX
421 		 * probably rates reporting as a host error
422 		 */
423 		if (csr & MUSB_TXCSR_P_SENTSTALL) {
424 			csr |= MUSB_TXCSR_P_WZC_BITS;
425 			csr &= ~MUSB_TXCSR_P_SENTSTALL;
426 			musb_writew(epio, MUSB_TXCSR, csr);
427 			if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
428 				dma->status = MUSB_DMA_STATUS_CORE_ABORT;
429 				musb->dma_controller->channel_abort(dma);
430 			}
431 
432 			if (request)
433 				musb_g_giveback(musb_ep, request, -EPIPE);
434 
435 			break;
436 		}
437 
438 		if (csr & MUSB_TXCSR_P_UNDERRUN) {
439 			/* we NAKed, no big deal ... little reason to care */
440 			csr |= MUSB_TXCSR_P_WZC_BITS;
441 			csr &= ~(MUSB_TXCSR_P_UNDERRUN
442 					| MUSB_TXCSR_TXPKTRDY);
443 			musb_writew(epio, MUSB_TXCSR, csr);
444 			DBG(20, "underrun on ep%d, req %p\n", epnum, request);
445 		}
446 
447 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
448 			/* SHOULD NOT HAPPEN ... has with cppi though, after
449 			 * changing SENDSTALL (and other cases); harmless?
450 			 */
451 			DBG(5, "%s dma still busy?\n", musb_ep->end_point.name);
452 			break;
453 		}
454 
455 		if (request) {
456 			u8	is_dma = 0;
457 
458 			if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
459 				is_dma = 1;
460 				csr |= MUSB_TXCSR_P_WZC_BITS;
461 				csr &= ~(MUSB_TXCSR_DMAENAB
462 						| MUSB_TXCSR_P_UNDERRUN
463 						| MUSB_TXCSR_TXPKTRDY);
464 				musb_writew(epio, MUSB_TXCSR, csr);
465 				/* ensure writebuffer is empty */
466 				csr = musb_readw(epio, MUSB_TXCSR);
467 				request->actual += musb_ep->dma->actual_len;
468 				DBG(4, "TXCSR%d %04x, dma off, "
469 						"len %zu, req %p\n",
470 					epnum, csr,
471 					musb_ep->dma->actual_len,
472 					request);
473 			}
474 
475 			if (is_dma || request->actual == request->length) {
476 
477 				/* First, maybe a terminating short packet.
478 				 * Some DMA engines might handle this by
479 				 * themselves.
480 				 */
481 				if ((request->zero
482 						&& request->length
483 						&& (request->length
484 							% musb_ep->packet_sz)
485 							== 0)
486 #ifdef CONFIG_USB_INVENTRA_DMA
487 					|| (is_dma &&
488 						((!dma->desired_mode) ||
489 						    (request->actual &
490 						    (musb_ep->packet_sz - 1))))
491 #endif
492 				) {
493 					/* on dma completion, fifo may not
494 					 * be available yet ...
495 					 */
496 					if (csr & MUSB_TXCSR_TXPKTRDY)
497 						break;
498 
499 					DBG(4, "sending zero pkt\n");
500 					musb_writew(epio, MUSB_TXCSR,
501 							MUSB_TXCSR_MODE
502 							| MUSB_TXCSR_TXPKTRDY);
503 					request->zero = 0;
504 				}
505 
506 				/* ... or if not, then complete it */
507 				musb_g_giveback(musb_ep, request, 0);
508 
509 				/* kickstart next transfer if appropriate;
510 				 * the packet that just completed might not
511 				 * be transmitted for hours or days.
512 				 * REVISIT for double buffering...
513 				 * FIXME revisit for stalls too...
514 				 */
515 				musb_ep_select(mbase, epnum);
516 				csr = musb_readw(epio, MUSB_TXCSR);
517 				if (csr & MUSB_TXCSR_FIFONOTEMPTY)
518 					break;
519 				request = musb_ep->desc
520 						? next_request(musb_ep)
521 						: NULL;
522 				if (!request) {
523 					DBG(4, "%s idle now\n",
524 						musb_ep->end_point.name);
525 					break;
526 				}
527 			}
528 
529 			txstate(musb, to_musb_request(request));
530 		}
531 
532 	} while (0);
533 }
534 
535 /* ------------------------------------------------------------ */
536 
537 #ifdef CONFIG_USB_INVENTRA_DMA
538 
539 /* Peripheral rx (OUT) using Mentor DMA works as follows:
540 	- Only mode 0 is used.
541 
542 	- Request is queued by the gadget class driver.
543 		-> if queue was previously empty, rxstate()
544 
545 	- Host sends OUT token which causes an endpoint interrupt
546 	  /\      -> RxReady
547 	  |	      -> if request queued, call rxstate
548 	  |		/\	-> setup DMA
549 	  |		|	     -> DMA interrupt on completion
550 	  |		|		-> RxReady
551 	  |		|		      -> stop DMA
552 	  |		|		      -> ack the read
553 	  |		|		      -> if data recd = max expected
554 	  |		|				by the request, or host
555 	  |		|				sent a short packet,
556 	  |		|				complete the request,
557 	  |		|				and start the next one.
558 	  |		|_____________________________________|
559 	  |					 else just wait for the host
560 	  |					    to send the next OUT token.
561 	  |__________________________________________________|
562 
563  * Non-Mentor DMA engines can of course work differently.
564  */
565 
566 #endif
567 
568 /*
569  * Context: controller locked, IRQs blocked, endpoint selected
570  */
571 static void rxstate(struct musb *musb, struct musb_request *req)
572 {
573 	u16			csr = 0;
574 	const u8		epnum = req->epnum;
575 	struct usb_request	*request = &req->request;
576 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_out;
577 	void __iomem		*epio = musb->endpoints[epnum].regs;
578 	u16			fifo_count = 0;
579 	u16			len = musb_ep->packet_sz;
580 
581 	csr = musb_readw(epio, MUSB_RXCSR);
582 
583 	if (is_cppi_enabled() && musb_ep->dma) {
584 		struct dma_controller	*c = musb->dma_controller;
585 		struct dma_channel	*channel = musb_ep->dma;
586 
587 		/* NOTE:  CPPI won't actually stop advancing the DMA
588 		 * queue after short packet transfers, so this is almost
589 		 * always going to run as IRQ-per-packet DMA so that
590 		 * faults will be handled correctly.
591 		 */
592 		if (c->channel_program(channel,
593 				musb_ep->packet_sz,
594 				!request->short_not_ok,
595 				request->dma + request->actual,
596 				request->length - request->actual)) {
597 
598 			/* make sure that if an rxpkt arrived after the irq,
599 			 * the cppi engine will be ready to take it as soon
600 			 * as DMA is enabled
601 			 */
602 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
603 					| MUSB_RXCSR_DMAMODE);
604 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
605 			musb_writew(epio, MUSB_RXCSR, csr);
606 			return;
607 		}
608 	}
609 
610 	if (csr & MUSB_RXCSR_RXPKTRDY) {
611 		len = musb_readw(epio, MUSB_RXCOUNT);
612 		if (request->actual < request->length) {
613 #ifdef CONFIG_USB_INVENTRA_DMA
614 			if (is_dma_capable() && musb_ep->dma) {
615 				struct dma_controller	*c;
616 				struct dma_channel	*channel;
617 				int			use_dma = 0;
618 
619 				c = musb->dma_controller;
620 				channel = musb_ep->dma;
621 
622 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
623 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
624 	 * completion. We only get interrupts from DMA controller.
625 	 *
626 	 * We could operate in DMA mode 1 if we knew the size of the tranfer
627 	 * in advance. For mass storage class, request->length = what the host
628 	 * sends, so that'd work.  But for pretty much everything else,
629 	 * request->length is routinely more than what the host sends. For
630 	 * most these gadgets, end of is signified either by a short packet,
631 	 * or filling the last byte of the buffer.  (Sending extra data in
632 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
633 	 * we don't get DMA completion interrrupt for short packets.
634 	 *
635 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
636 	 * to get endpoint interrupt on every DMA req, but that didn't seem
637 	 * to work reliably.
638 	 *
639 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
640 	 * then becomes usable as a runtime "use mode 1" hint...
641 	 */
642 
643 				csr |= MUSB_RXCSR_DMAENAB;
644 #ifdef USE_MODE1
645 				csr |= MUSB_RXCSR_AUTOCLEAR;
646 				/* csr |= MUSB_RXCSR_DMAMODE; */
647 
648 				/* this special sequence (enabling and then
649 				 * disabling MUSB_RXCSR_DMAMODE) is required
650 				 * to get DMAReq to activate
651 				 */
652 				musb_writew(epio, MUSB_RXCSR,
653 					csr | MUSB_RXCSR_DMAMODE);
654 #endif
655 				musb_writew(epio, MUSB_RXCSR, csr);
656 
657 				if (request->actual < request->length) {
658 					int transfer_size = 0;
659 #ifdef USE_MODE1
660 					transfer_size = min(request->length,
661 							channel->max_len);
662 #else
663 					transfer_size = len;
664 #endif
665 					if (transfer_size <= musb_ep->packet_sz)
666 						musb_ep->dma->desired_mode = 0;
667 					else
668 						musb_ep->dma->desired_mode = 1;
669 
670 					use_dma = c->channel_program(
671 							channel,
672 							musb_ep->packet_sz,
673 							channel->desired_mode,
674 							request->dma
675 							+ request->actual,
676 							transfer_size);
677 				}
678 
679 				if (use_dma)
680 					return;
681 			}
682 #endif	/* Mentor's DMA */
683 
684 			fifo_count = request->length - request->actual;
685 			DBG(3, "%s OUT/RX pio fifo %d/%d, maxpacket %d\n",
686 					musb_ep->end_point.name,
687 					len, fifo_count,
688 					musb_ep->packet_sz);
689 
690 			fifo_count = min(len, fifo_count);
691 
692 #ifdef	CONFIG_USB_TUSB_OMAP_DMA
693 			if (tusb_dma_omap() && musb_ep->dma) {
694 				struct dma_controller *c = musb->dma_controller;
695 				struct dma_channel *channel = musb_ep->dma;
696 				u32 dma_addr = request->dma + request->actual;
697 				int ret;
698 
699 				ret = c->channel_program(channel,
700 						musb_ep->packet_sz,
701 						channel->desired_mode,
702 						dma_addr,
703 						fifo_count);
704 				if (ret)
705 					return;
706 			}
707 #endif
708 
709 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
710 					(request->buf + request->actual));
711 			request->actual += fifo_count;
712 
713 			/* REVISIT if we left anything in the fifo, flush
714 			 * it and report -EOVERFLOW
715 			 */
716 
717 			/* ack the read! */
718 			csr |= MUSB_RXCSR_P_WZC_BITS;
719 			csr &= ~MUSB_RXCSR_RXPKTRDY;
720 			musb_writew(epio, MUSB_RXCSR, csr);
721 		}
722 	}
723 
724 	/* reach the end or short packet detected */
725 	if (request->actual == request->length || len < musb_ep->packet_sz)
726 		musb_g_giveback(musb_ep, request, 0);
727 }
728 
729 /*
730  * Data ready for a request; called from IRQ
731  */
732 void musb_g_rx(struct musb *musb, u8 epnum)
733 {
734 	u16			csr;
735 	struct usb_request	*request;
736 	void __iomem		*mbase = musb->mregs;
737 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_out;
738 	void __iomem		*epio = musb->endpoints[epnum].regs;
739 	struct dma_channel	*dma;
740 
741 	musb_ep_select(mbase, epnum);
742 
743 	request = next_request(musb_ep);
744 
745 	csr = musb_readw(epio, MUSB_RXCSR);
746 	dma = is_dma_capable() ? musb_ep->dma : NULL;
747 
748 	DBG(4, "<== %s, rxcsr %04x%s %p\n", musb_ep->end_point.name,
749 			csr, dma ? " (dma)" : "", request);
750 
751 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
752 		if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
753 			dma->status = MUSB_DMA_STATUS_CORE_ABORT;
754 			(void) musb->dma_controller->channel_abort(dma);
755 			request->actual += musb_ep->dma->actual_len;
756 		}
757 
758 		csr |= MUSB_RXCSR_P_WZC_BITS;
759 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
760 		musb_writew(epio, MUSB_RXCSR, csr);
761 
762 		if (request)
763 			musb_g_giveback(musb_ep, request, -EPIPE);
764 		goto done;
765 	}
766 
767 	if (csr & MUSB_RXCSR_P_OVERRUN) {
768 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
769 		csr &= ~MUSB_RXCSR_P_OVERRUN;
770 		musb_writew(epio, MUSB_RXCSR, csr);
771 
772 		DBG(3, "%s iso overrun on %p\n", musb_ep->name, request);
773 		if (request && request->status == -EINPROGRESS)
774 			request->status = -EOVERFLOW;
775 	}
776 	if (csr & MUSB_RXCSR_INCOMPRX) {
777 		/* REVISIT not necessarily an error */
778 		DBG(4, "%s, incomprx\n", musb_ep->end_point.name);
779 	}
780 
781 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
782 		/* "should not happen"; likely RXPKTRDY pending for DMA */
783 		DBG((csr & MUSB_RXCSR_DMAENAB) ? 4 : 1,
784 			"%s busy, csr %04x\n",
785 			musb_ep->end_point.name, csr);
786 		goto done;
787 	}
788 
789 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
790 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
791 				| MUSB_RXCSR_DMAENAB
792 				| MUSB_RXCSR_DMAMODE);
793 		musb_writew(epio, MUSB_RXCSR,
794 			MUSB_RXCSR_P_WZC_BITS | csr);
795 
796 		request->actual += musb_ep->dma->actual_len;
797 
798 		DBG(4, "RXCSR%d %04x, dma off, %04x, len %zu, req %p\n",
799 			epnum, csr,
800 			musb_readw(epio, MUSB_RXCSR),
801 			musb_ep->dma->actual_len, request);
802 
803 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA)
804 		/* Autoclear doesn't clear RxPktRdy for short packets */
805 		if ((dma->desired_mode == 0)
806 				|| (dma->actual_len
807 					& (musb_ep->packet_sz - 1))) {
808 			/* ack the read! */
809 			csr &= ~MUSB_RXCSR_RXPKTRDY;
810 			musb_writew(epio, MUSB_RXCSR, csr);
811 		}
812 
813 		/* incomplete, and not short? wait for next IN packet */
814 		if ((request->actual < request->length)
815 				&& (musb_ep->dma->actual_len
816 					== musb_ep->packet_sz))
817 			goto done;
818 #endif
819 		musb_g_giveback(musb_ep, request, 0);
820 
821 		request = next_request(musb_ep);
822 		if (!request)
823 			goto done;
824 
825 		/* don't start more i/o till the stall clears */
826 		musb_ep_select(mbase, epnum);
827 		csr = musb_readw(epio, MUSB_RXCSR);
828 		if (csr & MUSB_RXCSR_P_SENDSTALL)
829 			goto done;
830 	}
831 
832 
833 	/* analyze request if the ep is hot */
834 	if (request)
835 		rxstate(musb, to_musb_request(request));
836 	else
837 		DBG(3, "packet waiting for %s%s request\n",
838 				musb_ep->desc ? "" : "inactive ",
839 				musb_ep->end_point.name);
840 
841 done:
842 	return;
843 }
844 
845 /* ------------------------------------------------------------ */
846 
847 static int musb_gadget_enable(struct usb_ep *ep,
848 			const struct usb_endpoint_descriptor *desc)
849 {
850 	unsigned long		flags;
851 	struct musb_ep		*musb_ep;
852 	struct musb_hw_ep	*hw_ep;
853 	void __iomem		*regs;
854 	struct musb		*musb;
855 	void __iomem	*mbase;
856 	u8		epnum;
857 	u16		csr;
858 	unsigned	tmp;
859 	int		status = -EINVAL;
860 
861 	if (!ep || !desc)
862 		return -EINVAL;
863 
864 	musb_ep = to_musb_ep(ep);
865 	hw_ep = musb_ep->hw_ep;
866 	regs = hw_ep->regs;
867 	musb = musb_ep->musb;
868 	mbase = musb->mregs;
869 	epnum = musb_ep->current_epnum;
870 
871 	spin_lock_irqsave(&musb->lock, flags);
872 
873 	if (musb_ep->desc) {
874 		status = -EBUSY;
875 		goto fail;
876 	}
877 	musb_ep->type = desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK;
878 
879 	/* check direction and (later) maxpacket size against endpoint */
880 	if ((desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK) != epnum)
881 		goto fail;
882 
883 	/* REVISIT this rules out high bandwidth periodic transfers */
884 	tmp = le16_to_cpu(desc->wMaxPacketSize);
885 	if (tmp & ~0x07ff)
886 		goto fail;
887 	musb_ep->packet_sz = tmp;
888 
889 	/* enable the interrupts for the endpoint, set the endpoint
890 	 * packet size (or fail), set the mode, clear the fifo
891 	 */
892 	musb_ep_select(mbase, epnum);
893 	if (desc->bEndpointAddress & USB_DIR_IN) {
894 		u16 int_txe = musb_readw(mbase, MUSB_INTRTXE);
895 
896 		if (hw_ep->is_shared_fifo)
897 			musb_ep->is_in = 1;
898 		if (!musb_ep->is_in)
899 			goto fail;
900 		if (tmp > hw_ep->max_packet_sz_tx)
901 			goto fail;
902 
903 		int_txe |= (1 << epnum);
904 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
905 
906 		/* REVISIT if can_bulk_split(), use by updating "tmp";
907 		 * likewise high bandwidth periodic tx
908 		 */
909 		musb_writew(regs, MUSB_TXMAXP, tmp);
910 
911 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
912 		if (musb_readw(regs, MUSB_TXCSR)
913 				& MUSB_TXCSR_FIFONOTEMPTY)
914 			csr |= MUSB_TXCSR_FLUSHFIFO;
915 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
916 			csr |= MUSB_TXCSR_P_ISO;
917 
918 		/* set twice in case of double buffering */
919 		musb_writew(regs, MUSB_TXCSR, csr);
920 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
921 		musb_writew(regs, MUSB_TXCSR, csr);
922 
923 	} else {
924 		u16 int_rxe = musb_readw(mbase, MUSB_INTRRXE);
925 
926 		if (hw_ep->is_shared_fifo)
927 			musb_ep->is_in = 0;
928 		if (musb_ep->is_in)
929 			goto fail;
930 		if (tmp > hw_ep->max_packet_sz_rx)
931 			goto fail;
932 
933 		int_rxe |= (1 << epnum);
934 		musb_writew(mbase, MUSB_INTRRXE, int_rxe);
935 
936 		/* REVISIT if can_bulk_combine() use by updating "tmp"
937 		 * likewise high bandwidth periodic rx
938 		 */
939 		musb_writew(regs, MUSB_RXMAXP, tmp);
940 
941 		/* force shared fifo to OUT-only mode */
942 		if (hw_ep->is_shared_fifo) {
943 			csr = musb_readw(regs, MUSB_TXCSR);
944 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
945 			musb_writew(regs, MUSB_TXCSR, csr);
946 		}
947 
948 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
949 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
950 			csr |= MUSB_RXCSR_P_ISO;
951 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
952 			csr |= MUSB_RXCSR_DISNYET;
953 
954 		/* set twice in case of double buffering */
955 		musb_writew(regs, MUSB_RXCSR, csr);
956 		musb_writew(regs, MUSB_RXCSR, csr);
957 	}
958 
959 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
960 	 * for some reason you run out of channels here.
961 	 */
962 	if (is_dma_capable() && musb->dma_controller) {
963 		struct dma_controller	*c = musb->dma_controller;
964 
965 		musb_ep->dma = c->channel_alloc(c, hw_ep,
966 				(desc->bEndpointAddress & USB_DIR_IN));
967 	} else
968 		musb_ep->dma = NULL;
969 
970 	musb_ep->desc = desc;
971 	musb_ep->busy = 0;
972 	status = 0;
973 
974 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
975 			musb_driver_name, musb_ep->end_point.name,
976 			({ char *s; switch (musb_ep->type) {
977 			case USB_ENDPOINT_XFER_BULK:	s = "bulk"; break;
978 			case USB_ENDPOINT_XFER_INT:	s = "int"; break;
979 			default:			s = "iso"; break;
980 			}; s; }),
981 			musb_ep->is_in ? "IN" : "OUT",
982 			musb_ep->dma ? "dma, " : "",
983 			musb_ep->packet_sz);
984 
985 	schedule_work(&musb->irq_work);
986 
987 fail:
988 	spin_unlock_irqrestore(&musb->lock, flags);
989 	return status;
990 }
991 
992 /*
993  * Disable an endpoint flushing all requests queued.
994  */
995 static int musb_gadget_disable(struct usb_ep *ep)
996 {
997 	unsigned long	flags;
998 	struct musb	*musb;
999 	u8		epnum;
1000 	struct musb_ep	*musb_ep;
1001 	void __iomem	*epio;
1002 	int		status = 0;
1003 
1004 	musb_ep = to_musb_ep(ep);
1005 	musb = musb_ep->musb;
1006 	epnum = musb_ep->current_epnum;
1007 	epio = musb->endpoints[epnum].regs;
1008 
1009 	spin_lock_irqsave(&musb->lock, flags);
1010 	musb_ep_select(musb->mregs, epnum);
1011 
1012 	/* zero the endpoint sizes */
1013 	if (musb_ep->is_in) {
1014 		u16 int_txe = musb_readw(musb->mregs, MUSB_INTRTXE);
1015 		int_txe &= ~(1 << epnum);
1016 		musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
1017 		musb_writew(epio, MUSB_TXMAXP, 0);
1018 	} else {
1019 		u16 int_rxe = musb_readw(musb->mregs, MUSB_INTRRXE);
1020 		int_rxe &= ~(1 << epnum);
1021 		musb_writew(musb->mregs, MUSB_INTRRXE, int_rxe);
1022 		musb_writew(epio, MUSB_RXMAXP, 0);
1023 	}
1024 
1025 	musb_ep->desc = NULL;
1026 
1027 	/* abort all pending DMA and requests */
1028 	nuke(musb_ep, -ESHUTDOWN);
1029 
1030 	schedule_work(&musb->irq_work);
1031 
1032 	spin_unlock_irqrestore(&(musb->lock), flags);
1033 
1034 	DBG(2, "%s\n", musb_ep->end_point.name);
1035 
1036 	return status;
1037 }
1038 
1039 /*
1040  * Allocate a request for an endpoint.
1041  * Reused by ep0 code.
1042  */
1043 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1044 {
1045 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1046 	struct musb_request	*request = NULL;
1047 
1048 	request = kzalloc(sizeof *request, gfp_flags);
1049 	if (request) {
1050 		INIT_LIST_HEAD(&request->request.list);
1051 		request->request.dma = DMA_ADDR_INVALID;
1052 		request->epnum = musb_ep->current_epnum;
1053 		request->ep = musb_ep;
1054 	}
1055 
1056 	return &request->request;
1057 }
1058 
1059 /*
1060  * Free a request
1061  * Reused by ep0 code.
1062  */
1063 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1064 {
1065 	kfree(to_musb_request(req));
1066 }
1067 
1068 static LIST_HEAD(buffers);
1069 
1070 struct free_record {
1071 	struct list_head	list;
1072 	struct device		*dev;
1073 	unsigned		bytes;
1074 	dma_addr_t		dma;
1075 };
1076 
1077 /*
1078  * Context: controller locked, IRQs blocked.
1079  */
1080 static void musb_ep_restart(struct musb *musb, struct musb_request *req)
1081 {
1082 	DBG(3, "<== %s request %p len %u on hw_ep%d\n",
1083 		req->tx ? "TX/IN" : "RX/OUT",
1084 		&req->request, req->request.length, req->epnum);
1085 
1086 	musb_ep_select(musb->mregs, req->epnum);
1087 	if (req->tx)
1088 		txstate(musb, req);
1089 	else
1090 		rxstate(musb, req);
1091 }
1092 
1093 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1094 			gfp_t gfp_flags)
1095 {
1096 	struct musb_ep		*musb_ep;
1097 	struct musb_request	*request;
1098 	struct musb		*musb;
1099 	int			status = 0;
1100 	unsigned long		lockflags;
1101 
1102 	if (!ep || !req)
1103 		return -EINVAL;
1104 	if (!req->buf)
1105 		return -ENODATA;
1106 
1107 	musb_ep = to_musb_ep(ep);
1108 	musb = musb_ep->musb;
1109 
1110 	request = to_musb_request(req);
1111 	request->musb = musb;
1112 
1113 	if (request->ep != musb_ep)
1114 		return -EINVAL;
1115 
1116 	DBG(4, "<== to %s request=%p\n", ep->name, req);
1117 
1118 	/* request is mine now... */
1119 	request->request.actual = 0;
1120 	request->request.status = -EINPROGRESS;
1121 	request->epnum = musb_ep->current_epnum;
1122 	request->tx = musb_ep->is_in;
1123 
1124 	if (is_dma_capable() && musb_ep->dma) {
1125 		if (request->request.dma == DMA_ADDR_INVALID) {
1126 			request->request.dma = dma_map_single(
1127 					musb->controller,
1128 					request->request.buf,
1129 					request->request.length,
1130 					request->tx
1131 						? DMA_TO_DEVICE
1132 						: DMA_FROM_DEVICE);
1133 			request->mapped = 1;
1134 		} else {
1135 			dma_sync_single_for_device(musb->controller,
1136 					request->request.dma,
1137 					request->request.length,
1138 					request->tx
1139 						? DMA_TO_DEVICE
1140 						: DMA_FROM_DEVICE);
1141 			request->mapped = 0;
1142 		}
1143 	} else if (!req->buf) {
1144 		return -ENODATA;
1145 	} else
1146 		request->mapped = 0;
1147 
1148 	spin_lock_irqsave(&musb->lock, lockflags);
1149 
1150 	/* don't queue if the ep is down */
1151 	if (!musb_ep->desc) {
1152 		DBG(4, "req %p queued to %s while ep %s\n",
1153 				req, ep->name, "disabled");
1154 		status = -ESHUTDOWN;
1155 		goto cleanup;
1156 	}
1157 
1158 	/* add request to the list */
1159 	list_add_tail(&(request->request.list), &(musb_ep->req_list));
1160 
1161 	/* it this is the head of the queue, start i/o ... */
1162 	if (!musb_ep->busy && &request->request.list == musb_ep->req_list.next)
1163 		musb_ep_restart(musb, request);
1164 
1165 cleanup:
1166 	spin_unlock_irqrestore(&musb->lock, lockflags);
1167 	return status;
1168 }
1169 
1170 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1171 {
1172 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1173 	struct usb_request	*r;
1174 	unsigned long		flags;
1175 	int			status = 0;
1176 	struct musb		*musb = musb_ep->musb;
1177 
1178 	if (!ep || !request || to_musb_request(request)->ep != musb_ep)
1179 		return -EINVAL;
1180 
1181 	spin_lock_irqsave(&musb->lock, flags);
1182 
1183 	list_for_each_entry(r, &musb_ep->req_list, list) {
1184 		if (r == request)
1185 			break;
1186 	}
1187 	if (r != request) {
1188 		DBG(3, "request %p not queued to %s\n", request, ep->name);
1189 		status = -EINVAL;
1190 		goto done;
1191 	}
1192 
1193 	/* if the hardware doesn't have the request, easy ... */
1194 	if (musb_ep->req_list.next != &request->list || musb_ep->busy)
1195 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1196 
1197 	/* ... else abort the dma transfer ... */
1198 	else if (is_dma_capable() && musb_ep->dma) {
1199 		struct dma_controller	*c = musb->dma_controller;
1200 
1201 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1202 		if (c->channel_abort)
1203 			status = c->channel_abort(musb_ep->dma);
1204 		else
1205 			status = -EBUSY;
1206 		if (status == 0)
1207 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1208 	} else {
1209 		/* NOTE: by sticking to easily tested hardware/driver states,
1210 		 * we leave counting of in-flight packets imprecise.
1211 		 */
1212 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1213 	}
1214 
1215 done:
1216 	spin_unlock_irqrestore(&musb->lock, flags);
1217 	return status;
1218 }
1219 
1220 /*
1221  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1222  * data but will queue requests.
1223  *
1224  * exported to ep0 code
1225  */
1226 int musb_gadget_set_halt(struct usb_ep *ep, int value)
1227 {
1228 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1229 	u8			epnum = musb_ep->current_epnum;
1230 	struct musb		*musb = musb_ep->musb;
1231 	void __iomem		*epio = musb->endpoints[epnum].regs;
1232 	void __iomem		*mbase;
1233 	unsigned long		flags;
1234 	u16			csr;
1235 	struct musb_request	*request = NULL;
1236 	int			status = 0;
1237 
1238 	if (!ep)
1239 		return -EINVAL;
1240 	mbase = musb->mregs;
1241 
1242 	spin_lock_irqsave(&musb->lock, flags);
1243 
1244 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1245 		status = -EINVAL;
1246 		goto done;
1247 	}
1248 
1249 	musb_ep_select(mbase, epnum);
1250 
1251 	/* cannot portably stall with non-empty FIFO */
1252 	request = to_musb_request(next_request(musb_ep));
1253 	if (value && musb_ep->is_in) {
1254 		csr = musb_readw(epio, MUSB_TXCSR);
1255 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1256 			DBG(3, "%s fifo busy, cannot halt\n", ep->name);
1257 			spin_unlock_irqrestore(&musb->lock, flags);
1258 			return -EAGAIN;
1259 		}
1260 
1261 	}
1262 
1263 	/* set/clear the stall and toggle bits */
1264 	DBG(2, "%s: %s stall\n", ep->name, value ? "set" : "clear");
1265 	if (musb_ep->is_in) {
1266 		csr = musb_readw(epio, MUSB_TXCSR);
1267 		if (csr & MUSB_TXCSR_FIFONOTEMPTY)
1268 			csr |= MUSB_TXCSR_FLUSHFIFO;
1269 		csr |= MUSB_TXCSR_P_WZC_BITS
1270 			| MUSB_TXCSR_CLRDATATOG;
1271 		if (value)
1272 			csr |= MUSB_TXCSR_P_SENDSTALL;
1273 		else
1274 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1275 				| MUSB_TXCSR_P_SENTSTALL);
1276 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1277 		musb_writew(epio, MUSB_TXCSR, csr);
1278 	} else {
1279 		csr = musb_readw(epio, MUSB_RXCSR);
1280 		csr |= MUSB_RXCSR_P_WZC_BITS
1281 			| MUSB_RXCSR_FLUSHFIFO
1282 			| MUSB_RXCSR_CLRDATATOG;
1283 		if (value)
1284 			csr |= MUSB_RXCSR_P_SENDSTALL;
1285 		else
1286 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1287 				| MUSB_RXCSR_P_SENTSTALL);
1288 		musb_writew(epio, MUSB_RXCSR, csr);
1289 	}
1290 
1291 done:
1292 
1293 	/* maybe start the first request in the queue */
1294 	if (!musb_ep->busy && !value && request) {
1295 		DBG(3, "restarting the request\n");
1296 		musb_ep_restart(musb, request);
1297 	}
1298 
1299 	spin_unlock_irqrestore(&musb->lock, flags);
1300 	return status;
1301 }
1302 
1303 static int musb_gadget_fifo_status(struct usb_ep *ep)
1304 {
1305 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1306 	void __iomem		*epio = musb_ep->hw_ep->regs;
1307 	int			retval = -EINVAL;
1308 
1309 	if (musb_ep->desc && !musb_ep->is_in) {
1310 		struct musb		*musb = musb_ep->musb;
1311 		int			epnum = musb_ep->current_epnum;
1312 		void __iomem		*mbase = musb->mregs;
1313 		unsigned long		flags;
1314 
1315 		spin_lock_irqsave(&musb->lock, flags);
1316 
1317 		musb_ep_select(mbase, epnum);
1318 		/* FIXME return zero unless RXPKTRDY is set */
1319 		retval = musb_readw(epio, MUSB_RXCOUNT);
1320 
1321 		spin_unlock_irqrestore(&musb->lock, flags);
1322 	}
1323 	return retval;
1324 }
1325 
1326 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1327 {
1328 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1329 	struct musb	*musb = musb_ep->musb;
1330 	u8		epnum = musb_ep->current_epnum;
1331 	void __iomem	*epio = musb->endpoints[epnum].regs;
1332 	void __iomem	*mbase;
1333 	unsigned long	flags;
1334 	u16		csr, int_txe;
1335 
1336 	mbase = musb->mregs;
1337 
1338 	spin_lock_irqsave(&musb->lock, flags);
1339 	musb_ep_select(mbase, (u8) epnum);
1340 
1341 	/* disable interrupts */
1342 	int_txe = musb_readw(mbase, MUSB_INTRTXE);
1343 	musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
1344 
1345 	if (musb_ep->is_in) {
1346 		csr = musb_readw(epio, MUSB_TXCSR);
1347 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1348 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1349 			musb_writew(epio, MUSB_TXCSR, csr);
1350 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1351 			musb_writew(epio, MUSB_TXCSR, csr);
1352 		}
1353 	} else {
1354 		csr = musb_readw(epio, MUSB_RXCSR);
1355 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1356 		musb_writew(epio, MUSB_RXCSR, csr);
1357 		musb_writew(epio, MUSB_RXCSR, csr);
1358 	}
1359 
1360 	/* re-enable interrupt */
1361 	musb_writew(mbase, MUSB_INTRTXE, int_txe);
1362 	spin_unlock_irqrestore(&musb->lock, flags);
1363 }
1364 
1365 static const struct usb_ep_ops musb_ep_ops = {
1366 	.enable		= musb_gadget_enable,
1367 	.disable	= musb_gadget_disable,
1368 	.alloc_request	= musb_alloc_request,
1369 	.free_request	= musb_free_request,
1370 	.queue		= musb_gadget_queue,
1371 	.dequeue	= musb_gadget_dequeue,
1372 	.set_halt	= musb_gadget_set_halt,
1373 	.fifo_status	= musb_gadget_fifo_status,
1374 	.fifo_flush	= musb_gadget_fifo_flush
1375 };
1376 
1377 /* ----------------------------------------------------------------------- */
1378 
1379 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1380 {
1381 	struct musb	*musb = gadget_to_musb(gadget);
1382 
1383 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1384 }
1385 
1386 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1387 {
1388 	struct musb	*musb = gadget_to_musb(gadget);
1389 	void __iomem	*mregs = musb->mregs;
1390 	unsigned long	flags;
1391 	int		status = -EINVAL;
1392 	u8		power, devctl;
1393 	int		retries;
1394 
1395 	spin_lock_irqsave(&musb->lock, flags);
1396 
1397 	switch (musb->xceiv.state) {
1398 	case OTG_STATE_B_PERIPHERAL:
1399 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1400 		 * that's part of the standard usb 1.1 state machine, and
1401 		 * doesn't affect OTG transitions.
1402 		 */
1403 		if (musb->may_wakeup && musb->is_suspended)
1404 			break;
1405 		goto done;
1406 	case OTG_STATE_B_IDLE:
1407 		/* Start SRP ... OTG not required. */
1408 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1409 		DBG(2, "Sending SRP: devctl: %02x\n", devctl);
1410 		devctl |= MUSB_DEVCTL_SESSION;
1411 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1412 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1413 		retries = 100;
1414 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1415 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1416 			if (retries-- < 1)
1417 				break;
1418 		}
1419 		retries = 10000;
1420 		while (devctl & MUSB_DEVCTL_SESSION) {
1421 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1422 			if (retries-- < 1)
1423 				break;
1424 		}
1425 
1426 		/* Block idling for at least 1s */
1427 		musb_platform_try_idle(musb,
1428 			jiffies + msecs_to_jiffies(1 * HZ));
1429 
1430 		status = 0;
1431 		goto done;
1432 	default:
1433 		DBG(2, "Unhandled wake: %s\n", otg_state_string(musb));
1434 		goto done;
1435 	}
1436 
1437 	status = 0;
1438 
1439 	power = musb_readb(mregs, MUSB_POWER);
1440 	power |= MUSB_POWER_RESUME;
1441 	musb_writeb(mregs, MUSB_POWER, power);
1442 	DBG(2, "issue wakeup\n");
1443 
1444 	/* FIXME do this next chunk in a timer callback, no udelay */
1445 	mdelay(2);
1446 
1447 	power = musb_readb(mregs, MUSB_POWER);
1448 	power &= ~MUSB_POWER_RESUME;
1449 	musb_writeb(mregs, MUSB_POWER, power);
1450 done:
1451 	spin_unlock_irqrestore(&musb->lock, flags);
1452 	return status;
1453 }
1454 
1455 static int
1456 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1457 {
1458 	struct musb	*musb = gadget_to_musb(gadget);
1459 
1460 	musb->is_self_powered = !!is_selfpowered;
1461 	return 0;
1462 }
1463 
1464 static void musb_pullup(struct musb *musb, int is_on)
1465 {
1466 	u8 power;
1467 
1468 	power = musb_readb(musb->mregs, MUSB_POWER);
1469 	if (is_on)
1470 		power |= MUSB_POWER_SOFTCONN;
1471 	else
1472 		power &= ~MUSB_POWER_SOFTCONN;
1473 
1474 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1475 
1476 	DBG(3, "gadget %s D+ pullup %s\n",
1477 		musb->gadget_driver->function, is_on ? "on" : "off");
1478 	musb_writeb(musb->mregs, MUSB_POWER, power);
1479 }
1480 
1481 #if 0
1482 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1483 {
1484 	DBG(2, "<= %s =>\n", __func__);
1485 
1486 	/*
1487 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1488 	 * though that can clear it), just musb_pullup().
1489 	 */
1490 
1491 	return -EINVAL;
1492 }
1493 #endif
1494 
1495 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1496 {
1497 	struct musb	*musb = gadget_to_musb(gadget);
1498 
1499 	if (!musb->xceiv.set_power)
1500 		return -EOPNOTSUPP;
1501 	return otg_set_power(&musb->xceiv, mA);
1502 }
1503 
1504 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1505 {
1506 	struct musb	*musb = gadget_to_musb(gadget);
1507 	unsigned long	flags;
1508 
1509 	is_on = !!is_on;
1510 
1511 	/* NOTE: this assumes we are sensing vbus; we'd rather
1512 	 * not pullup unless the B-session is active.
1513 	 */
1514 	spin_lock_irqsave(&musb->lock, flags);
1515 	if (is_on != musb->softconnect) {
1516 		musb->softconnect = is_on;
1517 		musb_pullup(musb, is_on);
1518 	}
1519 	spin_unlock_irqrestore(&musb->lock, flags);
1520 	return 0;
1521 }
1522 
1523 static const struct usb_gadget_ops musb_gadget_operations = {
1524 	.get_frame		= musb_gadget_get_frame,
1525 	.wakeup			= musb_gadget_wakeup,
1526 	.set_selfpowered	= musb_gadget_set_self_powered,
1527 	/* .vbus_session		= musb_gadget_vbus_session, */
1528 	.vbus_draw		= musb_gadget_vbus_draw,
1529 	.pullup			= musb_gadget_pullup,
1530 };
1531 
1532 /* ----------------------------------------------------------------------- */
1533 
1534 /* Registration */
1535 
1536 /* Only this registration code "knows" the rule (from USB standards)
1537  * about there being only one external upstream port.  It assumes
1538  * all peripheral ports are external...
1539  */
1540 static struct musb *the_gadget;
1541 
1542 static void musb_gadget_release(struct device *dev)
1543 {
1544 	/* kref_put(WHAT) */
1545 	dev_dbg(dev, "%s\n", __func__);
1546 }
1547 
1548 
1549 static void __init
1550 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1551 {
1552 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1553 
1554 	memset(ep, 0, sizeof *ep);
1555 
1556 	ep->current_epnum = epnum;
1557 	ep->musb = musb;
1558 	ep->hw_ep = hw_ep;
1559 	ep->is_in = is_in;
1560 
1561 	INIT_LIST_HEAD(&ep->req_list);
1562 
1563 	sprintf(ep->name, "ep%d%s", epnum,
1564 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1565 				is_in ? "in" : "out"));
1566 	ep->end_point.name = ep->name;
1567 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1568 	if (!epnum) {
1569 		ep->end_point.maxpacket = 64;
1570 		ep->end_point.ops = &musb_g_ep0_ops;
1571 		musb->g.ep0 = &ep->end_point;
1572 	} else {
1573 		if (is_in)
1574 			ep->end_point.maxpacket = hw_ep->max_packet_sz_tx;
1575 		else
1576 			ep->end_point.maxpacket = hw_ep->max_packet_sz_rx;
1577 		ep->end_point.ops = &musb_ep_ops;
1578 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1579 	}
1580 }
1581 
1582 /*
1583  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1584  * to the rest of the driver state.
1585  */
1586 static inline void __init musb_g_init_endpoints(struct musb *musb)
1587 {
1588 	u8			epnum;
1589 	struct musb_hw_ep	*hw_ep;
1590 	unsigned		count = 0;
1591 
1592 	/* intialize endpoint list just once */
1593 	INIT_LIST_HEAD(&(musb->g.ep_list));
1594 
1595 	for (epnum = 0, hw_ep = musb->endpoints;
1596 			epnum < musb->nr_endpoints;
1597 			epnum++, hw_ep++) {
1598 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1599 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1600 			count++;
1601 		} else {
1602 			if (hw_ep->max_packet_sz_tx) {
1603 				init_peripheral_ep(musb, &hw_ep->ep_in,
1604 							epnum, 1);
1605 				count++;
1606 			}
1607 			if (hw_ep->max_packet_sz_rx) {
1608 				init_peripheral_ep(musb, &hw_ep->ep_out,
1609 							epnum, 0);
1610 				count++;
1611 			}
1612 		}
1613 	}
1614 }
1615 
1616 /* called once during driver setup to initialize and link into
1617  * the driver model; memory is zeroed.
1618  */
1619 int __init musb_gadget_setup(struct musb *musb)
1620 {
1621 	int status;
1622 
1623 	/* REVISIT minor race:  if (erroneously) setting up two
1624 	 * musb peripherals at the same time, only the bus lock
1625 	 * is probably held.
1626 	 */
1627 	if (the_gadget)
1628 		return -EBUSY;
1629 	the_gadget = musb;
1630 
1631 	musb->g.ops = &musb_gadget_operations;
1632 	musb->g.is_dualspeed = 1;
1633 	musb->g.speed = USB_SPEED_UNKNOWN;
1634 
1635 	/* this "gadget" abstracts/virtualizes the controller */
1636 	strcpy(musb->g.dev.bus_id, "gadget");
1637 	musb->g.dev.parent = musb->controller;
1638 	musb->g.dev.dma_mask = musb->controller->dma_mask;
1639 	musb->g.dev.release = musb_gadget_release;
1640 	musb->g.name = musb_driver_name;
1641 
1642 	if (is_otg_enabled(musb))
1643 		musb->g.is_otg = 1;
1644 
1645 	musb_g_init_endpoints(musb);
1646 
1647 	musb->is_active = 0;
1648 	musb_platform_try_idle(musb, 0);
1649 
1650 	status = device_register(&musb->g.dev);
1651 	if (status != 0)
1652 		the_gadget = NULL;
1653 	return status;
1654 }
1655 
1656 void musb_gadget_cleanup(struct musb *musb)
1657 {
1658 	if (musb != the_gadget)
1659 		return;
1660 
1661 	device_unregister(&musb->g.dev);
1662 	the_gadget = NULL;
1663 }
1664 
1665 /*
1666  * Register the gadget driver. Used by gadget drivers when
1667  * registering themselves with the controller.
1668  *
1669  * -EINVAL something went wrong (not driver)
1670  * -EBUSY another gadget is already using the controller
1671  * -ENOMEM no memeory to perform the operation
1672  *
1673  * @param driver the gadget driver
1674  * @return <0 if error, 0 if everything is fine
1675  */
1676 int usb_gadget_register_driver(struct usb_gadget_driver *driver)
1677 {
1678 	int retval;
1679 	unsigned long flags;
1680 	struct musb *musb = the_gadget;
1681 
1682 	if (!driver
1683 			|| driver->speed != USB_SPEED_HIGH
1684 			|| !driver->bind
1685 			|| !driver->setup)
1686 		return -EINVAL;
1687 
1688 	/* driver must be initialized to support peripheral mode */
1689 	if (!musb || !(musb->board_mode == MUSB_OTG
1690 				|| musb->board_mode != MUSB_OTG)) {
1691 		DBG(1, "%s, no dev??\n", __func__);
1692 		return -ENODEV;
1693 	}
1694 
1695 	DBG(3, "registering driver %s\n", driver->function);
1696 	spin_lock_irqsave(&musb->lock, flags);
1697 
1698 	if (musb->gadget_driver) {
1699 		DBG(1, "%s is already bound to %s\n",
1700 				musb_driver_name,
1701 				musb->gadget_driver->driver.name);
1702 		retval = -EBUSY;
1703 	} else {
1704 		musb->gadget_driver = driver;
1705 		musb->g.dev.driver = &driver->driver;
1706 		driver->driver.bus = NULL;
1707 		musb->softconnect = 1;
1708 		retval = 0;
1709 	}
1710 
1711 	spin_unlock_irqrestore(&musb->lock, flags);
1712 
1713 	if (retval == 0) {
1714 		retval = driver->bind(&musb->g);
1715 		if (retval != 0) {
1716 			DBG(3, "bind to driver %s failed --> %d\n",
1717 					driver->driver.name, retval);
1718 			musb->gadget_driver = NULL;
1719 			musb->g.dev.driver = NULL;
1720 		}
1721 
1722 		spin_lock_irqsave(&musb->lock, flags);
1723 
1724 		/* REVISIT always use otg_set_peripheral(), handling
1725 		 * issues including the root hub one below ...
1726 		 */
1727 		musb->xceiv.gadget = &musb->g;
1728 		musb->xceiv.state = OTG_STATE_B_IDLE;
1729 		musb->is_active = 1;
1730 
1731 		/* FIXME this ignores the softconnect flag.  Drivers are
1732 		 * allowed hold the peripheral inactive until for example
1733 		 * userspace hooks up printer hardware or DSP codecs, so
1734 		 * hosts only see fully functional devices.
1735 		 */
1736 
1737 		if (!is_otg_enabled(musb))
1738 			musb_start(musb);
1739 
1740 		spin_unlock_irqrestore(&musb->lock, flags);
1741 
1742 		if (is_otg_enabled(musb)) {
1743 			DBG(3, "OTG startup...\n");
1744 
1745 			/* REVISIT:  funcall to other code, which also
1746 			 * handles power budgeting ... this way also
1747 			 * ensures HdrcStart is indirectly called.
1748 			 */
1749 			retval = usb_add_hcd(musb_to_hcd(musb), -1, 0);
1750 			if (retval < 0) {
1751 				DBG(1, "add_hcd failed, %d\n", retval);
1752 				spin_lock_irqsave(&musb->lock, flags);
1753 				musb->xceiv.gadget = NULL;
1754 				musb->xceiv.state = OTG_STATE_UNDEFINED;
1755 				musb->gadget_driver = NULL;
1756 				musb->g.dev.driver = NULL;
1757 				spin_unlock_irqrestore(&musb->lock, flags);
1758 			}
1759 		}
1760 	}
1761 
1762 	return retval;
1763 }
1764 EXPORT_SYMBOL(usb_gadget_register_driver);
1765 
1766 static void stop_activity(struct musb *musb, struct usb_gadget_driver *driver)
1767 {
1768 	int			i;
1769 	struct musb_hw_ep	*hw_ep;
1770 
1771 	/* don't disconnect if it's not connected */
1772 	if (musb->g.speed == USB_SPEED_UNKNOWN)
1773 		driver = NULL;
1774 	else
1775 		musb->g.speed = USB_SPEED_UNKNOWN;
1776 
1777 	/* deactivate the hardware */
1778 	if (musb->softconnect) {
1779 		musb->softconnect = 0;
1780 		musb_pullup(musb, 0);
1781 	}
1782 	musb_stop(musb);
1783 
1784 	/* killing any outstanding requests will quiesce the driver;
1785 	 * then report disconnect
1786 	 */
1787 	if (driver) {
1788 		for (i = 0, hw_ep = musb->endpoints;
1789 				i < musb->nr_endpoints;
1790 				i++, hw_ep++) {
1791 			musb_ep_select(musb->mregs, i);
1792 			if (hw_ep->is_shared_fifo /* || !epnum */) {
1793 				nuke(&hw_ep->ep_in, -ESHUTDOWN);
1794 			} else {
1795 				if (hw_ep->max_packet_sz_tx)
1796 					nuke(&hw_ep->ep_in, -ESHUTDOWN);
1797 				if (hw_ep->max_packet_sz_rx)
1798 					nuke(&hw_ep->ep_out, -ESHUTDOWN);
1799 			}
1800 		}
1801 
1802 		spin_unlock(&musb->lock);
1803 		driver->disconnect(&musb->g);
1804 		spin_lock(&musb->lock);
1805 	}
1806 }
1807 
1808 /*
1809  * Unregister the gadget driver. Used by gadget drivers when
1810  * unregistering themselves from the controller.
1811  *
1812  * @param driver the gadget driver to unregister
1813  */
1814 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1815 {
1816 	unsigned long	flags;
1817 	int		retval = 0;
1818 	struct musb	*musb = the_gadget;
1819 
1820 	if (!driver || !driver->unbind || !musb)
1821 		return -EINVAL;
1822 
1823 	/* REVISIT always use otg_set_peripheral() here too;
1824 	 * this needs to shut down the OTG engine.
1825 	 */
1826 
1827 	spin_lock_irqsave(&musb->lock, flags);
1828 
1829 #ifdef	CONFIG_USB_MUSB_OTG
1830 	musb_hnp_stop(musb);
1831 #endif
1832 
1833 	if (musb->gadget_driver == driver) {
1834 
1835 		(void) musb_gadget_vbus_draw(&musb->g, 0);
1836 
1837 		musb->xceiv.state = OTG_STATE_UNDEFINED;
1838 		stop_activity(musb, driver);
1839 
1840 		DBG(3, "unregistering driver %s\n", driver->function);
1841 		spin_unlock_irqrestore(&musb->lock, flags);
1842 		driver->unbind(&musb->g);
1843 		spin_lock_irqsave(&musb->lock, flags);
1844 
1845 		musb->gadget_driver = NULL;
1846 		musb->g.dev.driver = NULL;
1847 
1848 		musb->is_active = 0;
1849 		musb_platform_try_idle(musb, 0);
1850 	} else
1851 		retval = -EINVAL;
1852 	spin_unlock_irqrestore(&musb->lock, flags);
1853 
1854 	if (is_otg_enabled(musb) && retval == 0) {
1855 		usb_remove_hcd(musb_to_hcd(musb));
1856 		/* FIXME we need to be able to register another
1857 		 * gadget driver here and have everything work;
1858 		 * that currently misbehaves.
1859 		 */
1860 	}
1861 
1862 	return retval;
1863 }
1864 EXPORT_SYMBOL(usb_gadget_unregister_driver);
1865 
1866 
1867 /* ----------------------------------------------------------------------- */
1868 
1869 /* lifecycle operations called through plat_uds.c */
1870 
1871 void musb_g_resume(struct musb *musb)
1872 {
1873 	musb->is_suspended = 0;
1874 	switch (musb->xceiv.state) {
1875 	case OTG_STATE_B_IDLE:
1876 		break;
1877 	case OTG_STATE_B_WAIT_ACON:
1878 	case OTG_STATE_B_PERIPHERAL:
1879 		musb->is_active = 1;
1880 		if (musb->gadget_driver && musb->gadget_driver->resume) {
1881 			spin_unlock(&musb->lock);
1882 			musb->gadget_driver->resume(&musb->g);
1883 			spin_lock(&musb->lock);
1884 		}
1885 		break;
1886 	default:
1887 		WARNING("unhandled RESUME transition (%s)\n",
1888 				otg_state_string(musb));
1889 	}
1890 }
1891 
1892 /* called when SOF packets stop for 3+ msec */
1893 void musb_g_suspend(struct musb *musb)
1894 {
1895 	u8	devctl;
1896 
1897 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
1898 	DBG(3, "devctl %02x\n", devctl);
1899 
1900 	switch (musb->xceiv.state) {
1901 	case OTG_STATE_B_IDLE:
1902 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
1903 			musb->xceiv.state = OTG_STATE_B_PERIPHERAL;
1904 		break;
1905 	case OTG_STATE_B_PERIPHERAL:
1906 		musb->is_suspended = 1;
1907 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
1908 			spin_unlock(&musb->lock);
1909 			musb->gadget_driver->suspend(&musb->g);
1910 			spin_lock(&musb->lock);
1911 		}
1912 		break;
1913 	default:
1914 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
1915 		 * A_PERIPHERAL may need care too
1916 		 */
1917 		WARNING("unhandled SUSPEND transition (%s)\n",
1918 				otg_state_string(musb));
1919 	}
1920 }
1921 
1922 /* Called during SRP */
1923 void musb_g_wakeup(struct musb *musb)
1924 {
1925 	musb_gadget_wakeup(&musb->g);
1926 }
1927 
1928 /* called when VBUS drops below session threshold, and in other cases */
1929 void musb_g_disconnect(struct musb *musb)
1930 {
1931 	void __iomem	*mregs = musb->mregs;
1932 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
1933 
1934 	DBG(3, "devctl %02x\n", devctl);
1935 
1936 	/* clear HR */
1937 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
1938 
1939 	/* don't draw vbus until new b-default session */
1940 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1941 
1942 	musb->g.speed = USB_SPEED_UNKNOWN;
1943 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
1944 		spin_unlock(&musb->lock);
1945 		musb->gadget_driver->disconnect(&musb->g);
1946 		spin_lock(&musb->lock);
1947 	}
1948 
1949 	switch (musb->xceiv.state) {
1950 	default:
1951 #ifdef	CONFIG_USB_MUSB_OTG
1952 		DBG(2, "Unhandled disconnect %s, setting a_idle\n",
1953 			otg_state_string(musb));
1954 		musb->xceiv.state = OTG_STATE_A_IDLE;
1955 		break;
1956 	case OTG_STATE_A_PERIPHERAL:
1957 		musb->xceiv.state = OTG_STATE_A_WAIT_VFALL;
1958 		break;
1959 	case OTG_STATE_B_WAIT_ACON:
1960 	case OTG_STATE_B_HOST:
1961 #endif
1962 	case OTG_STATE_B_PERIPHERAL:
1963 	case OTG_STATE_B_IDLE:
1964 		musb->xceiv.state = OTG_STATE_B_IDLE;
1965 		break;
1966 	case OTG_STATE_B_SRP_INIT:
1967 		break;
1968 	}
1969 
1970 	musb->is_active = 0;
1971 }
1972 
1973 void musb_g_reset(struct musb *musb)
1974 __releases(musb->lock)
1975 __acquires(musb->lock)
1976 {
1977 	void __iomem	*mbase = musb->mregs;
1978 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
1979 	u8		power;
1980 
1981 	DBG(3, "<== %s addr=%x driver '%s'\n",
1982 			(devctl & MUSB_DEVCTL_BDEVICE)
1983 				? "B-Device" : "A-Device",
1984 			musb_readb(mbase, MUSB_FADDR),
1985 			musb->gadget_driver
1986 				? musb->gadget_driver->driver.name
1987 				: NULL
1988 			);
1989 
1990 	/* report disconnect, if we didn't already (flushing EP state) */
1991 	if (musb->g.speed != USB_SPEED_UNKNOWN)
1992 		musb_g_disconnect(musb);
1993 
1994 	/* clear HR */
1995 	else if (devctl & MUSB_DEVCTL_HR)
1996 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
1997 
1998 
1999 	/* what speed did we negotiate? */
2000 	power = musb_readb(mbase, MUSB_POWER);
2001 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2002 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2003 
2004 	/* start in USB_STATE_DEFAULT */
2005 	musb->is_active = 1;
2006 	musb->is_suspended = 0;
2007 	MUSB_DEV_MODE(musb);
2008 	musb->address = 0;
2009 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2010 
2011 	musb->may_wakeup = 0;
2012 	musb->g.b_hnp_enable = 0;
2013 	musb->g.a_alt_hnp_support = 0;
2014 	musb->g.a_hnp_support = 0;
2015 
2016 	/* Normal reset, as B-Device;
2017 	 * or else after HNP, as A-Device
2018 	 */
2019 	if (devctl & MUSB_DEVCTL_BDEVICE) {
2020 		musb->xceiv.state = OTG_STATE_B_PERIPHERAL;
2021 		musb->g.is_a_peripheral = 0;
2022 	} else if (is_otg_enabled(musb)) {
2023 		musb->xceiv.state = OTG_STATE_A_PERIPHERAL;
2024 		musb->g.is_a_peripheral = 1;
2025 	} else
2026 		WARN_ON(1);
2027 
2028 	/* start with default limits on VBUS power draw */
2029 	(void) musb_gadget_vbus_draw(&musb->g,
2030 			is_otg_enabled(musb) ? 8 : 100);
2031 }
2032