xref: /openbmc/linux/drivers/usb/musb/musb_gadget.c (revision e58e871b)
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  * Copyright (C) 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/kernel.h>
37 #include <linux/list.h>
38 #include <linux/timer.h>
39 #include <linux/module.h>
40 #include <linux/smp.h>
41 #include <linux/spinlock.h>
42 #include <linux/delay.h>
43 #include <linux/dma-mapping.h>
44 #include <linux/slab.h>
45 
46 #include "musb_core.h"
47 #include "musb_trace.h"
48 
49 
50 /* ----------------------------------------------------------------------- */
51 
52 #define is_buffer_mapped(req) (is_dma_capable() && \
53 					(req->map_state != UN_MAPPED))
54 
55 /* Maps the buffer to dma  */
56 
57 static inline void map_dma_buffer(struct musb_request *request,
58 			struct musb *musb, struct musb_ep *musb_ep)
59 {
60 	int compatible = true;
61 	struct dma_controller *dma = musb->dma_controller;
62 
63 	request->map_state = UN_MAPPED;
64 
65 	if (!is_dma_capable() || !musb_ep->dma)
66 		return;
67 
68 	/* Check if DMA engine can handle this request.
69 	 * DMA code must reject the USB request explicitly.
70 	 * Default behaviour is to map the request.
71 	 */
72 	if (dma->is_compatible)
73 		compatible = dma->is_compatible(musb_ep->dma,
74 				musb_ep->packet_sz, request->request.buf,
75 				request->request.length);
76 	if (!compatible)
77 		return;
78 
79 	if (request->request.dma == DMA_ADDR_INVALID) {
80 		dma_addr_t dma_addr;
81 		int ret;
82 
83 		dma_addr = dma_map_single(
84 				musb->controller,
85 				request->request.buf,
86 				request->request.length,
87 				request->tx
88 					? DMA_TO_DEVICE
89 					: DMA_FROM_DEVICE);
90 		ret = dma_mapping_error(musb->controller, dma_addr);
91 		if (ret)
92 			return;
93 
94 		request->request.dma = dma_addr;
95 		request->map_state = MUSB_MAPPED;
96 	} else {
97 		dma_sync_single_for_device(musb->controller,
98 			request->request.dma,
99 			request->request.length,
100 			request->tx
101 				? DMA_TO_DEVICE
102 				: DMA_FROM_DEVICE);
103 		request->map_state = PRE_MAPPED;
104 	}
105 }
106 
107 /* Unmap the buffer from dma and maps it back to cpu */
108 static inline void unmap_dma_buffer(struct musb_request *request,
109 				struct musb *musb)
110 {
111 	struct musb_ep *musb_ep = request->ep;
112 
113 	if (!is_buffer_mapped(request) || !musb_ep->dma)
114 		return;
115 
116 	if (request->request.dma == DMA_ADDR_INVALID) {
117 		dev_vdbg(musb->controller,
118 				"not unmapping a never mapped buffer\n");
119 		return;
120 	}
121 	if (request->map_state == MUSB_MAPPED) {
122 		dma_unmap_single(musb->controller,
123 			request->request.dma,
124 			request->request.length,
125 			request->tx
126 				? DMA_TO_DEVICE
127 				: DMA_FROM_DEVICE);
128 		request->request.dma = DMA_ADDR_INVALID;
129 	} else { /* PRE_MAPPED */
130 		dma_sync_single_for_cpu(musb->controller,
131 			request->request.dma,
132 			request->request.length,
133 			request->tx
134 				? DMA_TO_DEVICE
135 				: DMA_FROM_DEVICE);
136 	}
137 	request->map_state = UN_MAPPED;
138 }
139 
140 /*
141  * Immediately complete a request.
142  *
143  * @param request the request to complete
144  * @param status the status to complete the request with
145  * Context: controller locked, IRQs blocked.
146  */
147 void musb_g_giveback(
148 	struct musb_ep		*ep,
149 	struct usb_request	*request,
150 	int			status)
151 __releases(ep->musb->lock)
152 __acquires(ep->musb->lock)
153 {
154 	struct musb_request	*req;
155 	struct musb		*musb;
156 	int			busy = ep->busy;
157 
158 	req = to_musb_request(request);
159 
160 	list_del(&req->list);
161 	if (req->request.status == -EINPROGRESS)
162 		req->request.status = status;
163 	musb = req->musb;
164 
165 	ep->busy = 1;
166 	spin_unlock(&musb->lock);
167 
168 	if (!dma_mapping_error(&musb->g.dev, request->dma))
169 		unmap_dma_buffer(req, musb);
170 
171 	trace_musb_req_gb(req);
172 	usb_gadget_giveback_request(&req->ep->end_point, &req->request);
173 	spin_lock(&musb->lock);
174 	ep->busy = busy;
175 }
176 
177 /* ----------------------------------------------------------------------- */
178 
179 /*
180  * Abort requests queued to an endpoint using the status. Synchronous.
181  * caller locked controller and blocked irqs, and selected this ep.
182  */
183 static void nuke(struct musb_ep *ep, const int status)
184 {
185 	struct musb		*musb = ep->musb;
186 	struct musb_request	*req = NULL;
187 	void __iomem *epio = ep->musb->endpoints[ep->current_epnum].regs;
188 
189 	ep->busy = 1;
190 
191 	if (is_dma_capable() && ep->dma) {
192 		struct dma_controller	*c = ep->musb->dma_controller;
193 		int value;
194 
195 		if (ep->is_in) {
196 			/*
197 			 * The programming guide says that we must not clear
198 			 * the DMAMODE bit before DMAENAB, so we only
199 			 * clear it in the second write...
200 			 */
201 			musb_writew(epio, MUSB_TXCSR,
202 				    MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
203 			musb_writew(epio, MUSB_TXCSR,
204 					0 | MUSB_TXCSR_FLUSHFIFO);
205 		} else {
206 			musb_writew(epio, MUSB_RXCSR,
207 					0 | MUSB_RXCSR_FLUSHFIFO);
208 			musb_writew(epio, MUSB_RXCSR,
209 					0 | MUSB_RXCSR_FLUSHFIFO);
210 		}
211 
212 		value = c->channel_abort(ep->dma);
213 		musb_dbg(musb, "%s: abort DMA --> %d", ep->name, value);
214 		c->channel_release(ep->dma);
215 		ep->dma = NULL;
216 	}
217 
218 	while (!list_empty(&ep->req_list)) {
219 		req = list_first_entry(&ep->req_list, struct musb_request, list);
220 		musb_g_giveback(ep, &req->request, status);
221 	}
222 }
223 
224 /* ----------------------------------------------------------------------- */
225 
226 /* Data transfers - pure PIO, pure DMA, or mixed mode */
227 
228 /*
229  * This assumes the separate CPPI engine is responding to DMA requests
230  * from the usb core ... sequenced a bit differently from mentor dma.
231  */
232 
233 static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
234 {
235 	if (can_bulk_split(musb, ep->type))
236 		return ep->hw_ep->max_packet_sz_tx;
237 	else
238 		return ep->packet_sz;
239 }
240 
241 /*
242  * An endpoint is transmitting data. This can be called either from
243  * the IRQ routine or from ep.queue() to kickstart a request on an
244  * endpoint.
245  *
246  * Context: controller locked, IRQs blocked, endpoint selected
247  */
248 static void txstate(struct musb *musb, struct musb_request *req)
249 {
250 	u8			epnum = req->epnum;
251 	struct musb_ep		*musb_ep;
252 	void __iomem		*epio = musb->endpoints[epnum].regs;
253 	struct usb_request	*request;
254 	u16			fifo_count = 0, csr;
255 	int			use_dma = 0;
256 
257 	musb_ep = req->ep;
258 
259 	/* Check if EP is disabled */
260 	if (!musb_ep->desc) {
261 		musb_dbg(musb, "ep:%s disabled - ignore request",
262 						musb_ep->end_point.name);
263 		return;
264 	}
265 
266 	/* we shouldn't get here while DMA is active ... but we do ... */
267 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
268 		musb_dbg(musb, "dma pending...");
269 		return;
270 	}
271 
272 	/* read TXCSR before */
273 	csr = musb_readw(epio, MUSB_TXCSR);
274 
275 	request = &req->request;
276 	fifo_count = min(max_ep_writesize(musb, musb_ep),
277 			(int)(request->length - request->actual));
278 
279 	if (csr & MUSB_TXCSR_TXPKTRDY) {
280 		musb_dbg(musb, "%s old packet still ready , txcsr %03x",
281 				musb_ep->end_point.name, csr);
282 		return;
283 	}
284 
285 	if (csr & MUSB_TXCSR_P_SENDSTALL) {
286 		musb_dbg(musb, "%s stalling, txcsr %03x",
287 				musb_ep->end_point.name, csr);
288 		return;
289 	}
290 
291 	musb_dbg(musb, "hw_ep%d, maxpacket %d, fifo count %d, txcsr %03x",
292 			epnum, musb_ep->packet_sz, fifo_count,
293 			csr);
294 
295 #ifndef	CONFIG_MUSB_PIO_ONLY
296 	if (is_buffer_mapped(req)) {
297 		struct dma_controller	*c = musb->dma_controller;
298 		size_t request_size;
299 
300 		/* setup DMA, then program endpoint CSR */
301 		request_size = min_t(size_t, request->length - request->actual,
302 					musb_ep->dma->max_len);
303 
304 		use_dma = (request->dma != DMA_ADDR_INVALID && request_size);
305 
306 		/* MUSB_TXCSR_P_ISO is still set correctly */
307 
308 		if (musb_dma_inventra(musb) || musb_dma_ux500(musb)) {
309 			if (request_size < musb_ep->packet_sz)
310 				musb_ep->dma->desired_mode = 0;
311 			else
312 				musb_ep->dma->desired_mode = 1;
313 
314 			use_dma = use_dma && c->channel_program(
315 					musb_ep->dma, musb_ep->packet_sz,
316 					musb_ep->dma->desired_mode,
317 					request->dma + request->actual, request_size);
318 			if (use_dma) {
319 				if (musb_ep->dma->desired_mode == 0) {
320 					/*
321 					 * We must not clear the DMAMODE bit
322 					 * before the DMAENAB bit -- and the
323 					 * latter doesn't always get cleared
324 					 * before we get here...
325 					 */
326 					csr &= ~(MUSB_TXCSR_AUTOSET
327 						| MUSB_TXCSR_DMAENAB);
328 					musb_writew(epio, MUSB_TXCSR, csr
329 						| MUSB_TXCSR_P_WZC_BITS);
330 					csr &= ~MUSB_TXCSR_DMAMODE;
331 					csr |= (MUSB_TXCSR_DMAENAB |
332 							MUSB_TXCSR_MODE);
333 					/* against programming guide */
334 				} else {
335 					csr |= (MUSB_TXCSR_DMAENAB
336 							| MUSB_TXCSR_DMAMODE
337 							| MUSB_TXCSR_MODE);
338 					/*
339 					 * Enable Autoset according to table
340 					 * below
341 					 * bulk_split hb_mult	Autoset_Enable
342 					 *	0	0	Yes(Normal)
343 					 *	0	>0	No(High BW ISO)
344 					 *	1	0	Yes(HS bulk)
345 					 *	1	>0	Yes(FS bulk)
346 					 */
347 					if (!musb_ep->hb_mult ||
348 					    can_bulk_split(musb,
349 							   musb_ep->type))
350 						csr |= MUSB_TXCSR_AUTOSET;
351 				}
352 				csr &= ~MUSB_TXCSR_P_UNDERRUN;
353 
354 				musb_writew(epio, MUSB_TXCSR, csr);
355 			}
356 		}
357 
358 		if (is_cppi_enabled(musb)) {
359 			/* program endpoint CSR first, then setup DMA */
360 			csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
361 			csr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_DMAMODE |
362 				MUSB_TXCSR_MODE;
363 			musb_writew(epio, MUSB_TXCSR, (MUSB_TXCSR_P_WZC_BITS &
364 						~MUSB_TXCSR_P_UNDERRUN) | csr);
365 
366 			/* ensure writebuffer is empty */
367 			csr = musb_readw(epio, MUSB_TXCSR);
368 
369 			/*
370 			 * NOTE host side sets DMAENAB later than this; both are
371 			 * OK since the transfer dma glue (between CPPI and
372 			 * Mentor fifos) just tells CPPI it could start. Data
373 			 * only moves to the USB TX fifo when both fifos are
374 			 * ready.
375 			 */
376 			/*
377 			 * "mode" is irrelevant here; handle terminating ZLPs
378 			 * like PIO does, since the hardware RNDIS mode seems
379 			 * unreliable except for the
380 			 * last-packet-is-already-short case.
381 			 */
382 			use_dma = use_dma && c->channel_program(
383 					musb_ep->dma, musb_ep->packet_sz,
384 					0,
385 					request->dma + request->actual,
386 					request_size);
387 			if (!use_dma) {
388 				c->channel_release(musb_ep->dma);
389 				musb_ep->dma = NULL;
390 				csr &= ~MUSB_TXCSR_DMAENAB;
391 				musb_writew(epio, MUSB_TXCSR, csr);
392 				/* invariant: prequest->buf is non-null */
393 			}
394 		} else if (tusb_dma_omap(musb))
395 			use_dma = use_dma && c->channel_program(
396 					musb_ep->dma, musb_ep->packet_sz,
397 					request->zero,
398 					request->dma + request->actual,
399 					request_size);
400 	}
401 #endif
402 
403 	if (!use_dma) {
404 		/*
405 		 * Unmap the dma buffer back to cpu if dma channel
406 		 * programming fails
407 		 */
408 		unmap_dma_buffer(req, musb);
409 
410 		musb_write_fifo(musb_ep->hw_ep, fifo_count,
411 				(u8 *) (request->buf + request->actual));
412 		request->actual += fifo_count;
413 		csr |= MUSB_TXCSR_TXPKTRDY;
414 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
415 		musb_writew(epio, MUSB_TXCSR, csr);
416 	}
417 
418 	/* host may already have the data when this message shows... */
419 	musb_dbg(musb, "%s TX/IN %s len %d/%d, txcsr %04x, fifo %d/%d",
420 			musb_ep->end_point.name, use_dma ? "dma" : "pio",
421 			request->actual, request->length,
422 			musb_readw(epio, MUSB_TXCSR),
423 			fifo_count,
424 			musb_readw(epio, MUSB_TXMAXP));
425 }
426 
427 /*
428  * FIFO state update (e.g. data ready).
429  * Called from IRQ,  with controller locked.
430  */
431 void musb_g_tx(struct musb *musb, u8 epnum)
432 {
433 	u16			csr;
434 	struct musb_request	*req;
435 	struct usb_request	*request;
436 	u8 __iomem		*mbase = musb->mregs;
437 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_in;
438 	void __iomem		*epio = musb->endpoints[epnum].regs;
439 	struct dma_channel	*dma;
440 
441 	musb_ep_select(mbase, epnum);
442 	req = next_request(musb_ep);
443 	request = &req->request;
444 
445 	trace_musb_req_tx(req);
446 	csr = musb_readw(epio, MUSB_TXCSR);
447 	musb_dbg(musb, "<== %s, txcsr %04x", musb_ep->end_point.name, csr);
448 
449 	dma = is_dma_capable() ? musb_ep->dma : NULL;
450 
451 	/*
452 	 * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX
453 	 * probably rates reporting as a host error.
454 	 */
455 	if (csr & MUSB_TXCSR_P_SENTSTALL) {
456 		csr |=	MUSB_TXCSR_P_WZC_BITS;
457 		csr &= ~MUSB_TXCSR_P_SENTSTALL;
458 		musb_writew(epio, MUSB_TXCSR, csr);
459 		return;
460 	}
461 
462 	if (csr & MUSB_TXCSR_P_UNDERRUN) {
463 		/* We NAKed, no big deal... little reason to care. */
464 		csr |=	 MUSB_TXCSR_P_WZC_BITS;
465 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
466 		musb_writew(epio, MUSB_TXCSR, csr);
467 		dev_vdbg(musb->controller, "underrun on ep%d, req %p\n",
468 				epnum, request);
469 	}
470 
471 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
472 		/*
473 		 * SHOULD NOT HAPPEN... has with CPPI though, after
474 		 * changing SENDSTALL (and other cases); harmless?
475 		 */
476 		musb_dbg(musb, "%s dma still busy?", musb_ep->end_point.name);
477 		return;
478 	}
479 
480 	if (request) {
481 		u8	is_dma = 0;
482 		bool	short_packet = false;
483 
484 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
485 			is_dma = 1;
486 			csr |= MUSB_TXCSR_P_WZC_BITS;
487 			csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
488 				 MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET);
489 			musb_writew(epio, MUSB_TXCSR, csr);
490 			/* Ensure writebuffer is empty. */
491 			csr = musb_readw(epio, MUSB_TXCSR);
492 			request->actual += musb_ep->dma->actual_len;
493 			musb_dbg(musb, "TXCSR%d %04x, DMA off, len %zu, req %p",
494 				epnum, csr, musb_ep->dma->actual_len, request);
495 		}
496 
497 		/*
498 		 * First, maybe a terminating short packet. Some DMA
499 		 * engines might handle this by themselves.
500 		 */
501 		if ((request->zero && request->length)
502 			&& (request->length % musb_ep->packet_sz == 0)
503 			&& (request->actual == request->length))
504 				short_packet = true;
505 
506 		if ((musb_dma_inventra(musb) || musb_dma_ux500(musb)) &&
507 			(is_dma && (!dma->desired_mode ||
508 				(request->actual &
509 					(musb_ep->packet_sz - 1)))))
510 				short_packet = true;
511 
512 		if (short_packet) {
513 			/*
514 			 * On DMA completion, FIFO may not be
515 			 * available yet...
516 			 */
517 			if (csr & MUSB_TXCSR_TXPKTRDY)
518 				return;
519 
520 			musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
521 					| MUSB_TXCSR_TXPKTRDY);
522 			request->zero = 0;
523 		}
524 
525 		if (request->actual == request->length) {
526 			musb_g_giveback(musb_ep, request, 0);
527 			/*
528 			 * In the giveback function the MUSB lock is
529 			 * released and acquired after sometime. During
530 			 * this time period the INDEX register could get
531 			 * changed by the gadget_queue function especially
532 			 * on SMP systems. Reselect the INDEX to be sure
533 			 * we are reading/modifying the right registers
534 			 */
535 			musb_ep_select(mbase, epnum);
536 			req = musb_ep->desc ? next_request(musb_ep) : NULL;
537 			if (!req) {
538 				musb_dbg(musb, "%s idle now",
539 					musb_ep->end_point.name);
540 				return;
541 			}
542 		}
543 
544 		txstate(musb, req);
545 	}
546 }
547 
548 /* ------------------------------------------------------------ */
549 
550 /*
551  * Context: controller locked, IRQs blocked, endpoint selected
552  */
553 static void rxstate(struct musb *musb, struct musb_request *req)
554 {
555 	const u8		epnum = req->epnum;
556 	struct usb_request	*request = &req->request;
557 	struct musb_ep		*musb_ep;
558 	void __iomem		*epio = musb->endpoints[epnum].regs;
559 	unsigned		len = 0;
560 	u16			fifo_count;
561 	u16			csr = musb_readw(epio, MUSB_RXCSR);
562 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
563 	u8			use_mode_1;
564 
565 	if (hw_ep->is_shared_fifo)
566 		musb_ep = &hw_ep->ep_in;
567 	else
568 		musb_ep = &hw_ep->ep_out;
569 
570 	fifo_count = musb_ep->packet_sz;
571 
572 	/* Check if EP is disabled */
573 	if (!musb_ep->desc) {
574 		musb_dbg(musb, "ep:%s disabled - ignore request",
575 						musb_ep->end_point.name);
576 		return;
577 	}
578 
579 	/* We shouldn't get here while DMA is active, but we do... */
580 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
581 		musb_dbg(musb, "DMA pending...");
582 		return;
583 	}
584 
585 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
586 		musb_dbg(musb, "%s stalling, RXCSR %04x",
587 		    musb_ep->end_point.name, csr);
588 		return;
589 	}
590 
591 	if (is_cppi_enabled(musb) && is_buffer_mapped(req)) {
592 		struct dma_controller	*c = musb->dma_controller;
593 		struct dma_channel	*channel = musb_ep->dma;
594 
595 		/* NOTE:  CPPI won't actually stop advancing the DMA
596 		 * queue after short packet transfers, so this is almost
597 		 * always going to run as IRQ-per-packet DMA so that
598 		 * faults will be handled correctly.
599 		 */
600 		if (c->channel_program(channel,
601 				musb_ep->packet_sz,
602 				!request->short_not_ok,
603 				request->dma + request->actual,
604 				request->length - request->actual)) {
605 
606 			/* make sure that if an rxpkt arrived after the irq,
607 			 * the cppi engine will be ready to take it as soon
608 			 * as DMA is enabled
609 			 */
610 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
611 					| MUSB_RXCSR_DMAMODE);
612 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
613 			musb_writew(epio, MUSB_RXCSR, csr);
614 			return;
615 		}
616 	}
617 
618 	if (csr & MUSB_RXCSR_RXPKTRDY) {
619 		fifo_count = musb_readw(epio, MUSB_RXCOUNT);
620 
621 		/*
622 		 * Enable Mode 1 on RX transfers only when short_not_ok flag
623 		 * is set. Currently short_not_ok flag is set only from
624 		 * file_storage and f_mass_storage drivers
625 		 */
626 
627 		if (request->short_not_ok && fifo_count == musb_ep->packet_sz)
628 			use_mode_1 = 1;
629 		else
630 			use_mode_1 = 0;
631 
632 		if (request->actual < request->length) {
633 			if (!is_buffer_mapped(req))
634 				goto buffer_aint_mapped;
635 
636 			if (musb_dma_inventra(musb)) {
637 				struct dma_controller	*c;
638 				struct dma_channel	*channel;
639 				int			use_dma = 0;
640 				unsigned int transfer_size;
641 
642 				c = musb->dma_controller;
643 				channel = musb_ep->dma;
644 
645 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
646 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
647 	 * completion. We only get interrupts from DMA controller.
648 	 *
649 	 * We could operate in DMA mode 1 if we knew the size of the tranfer
650 	 * in advance. For mass storage class, request->length = what the host
651 	 * sends, so that'd work.  But for pretty much everything else,
652 	 * request->length is routinely more than what the host sends. For
653 	 * most these gadgets, end of is signified either by a short packet,
654 	 * or filling the last byte of the buffer.  (Sending extra data in
655 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
656 	 * we don't get DMA completion interrupt for short packets.
657 	 *
658 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
659 	 * to get endpoint interrupt on every DMA req, but that didn't seem
660 	 * to work reliably.
661 	 *
662 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
663 	 * then becomes usable as a runtime "use mode 1" hint...
664 	 */
665 
666 				/* Experimental: Mode1 works with mass storage use cases */
667 				if (use_mode_1) {
668 					csr |= MUSB_RXCSR_AUTOCLEAR;
669 					musb_writew(epio, MUSB_RXCSR, csr);
670 					csr |= MUSB_RXCSR_DMAENAB;
671 					musb_writew(epio, MUSB_RXCSR, csr);
672 
673 					/*
674 					 * this special sequence (enabling and then
675 					 * disabling MUSB_RXCSR_DMAMODE) is required
676 					 * to get DMAReq to activate
677 					 */
678 					musb_writew(epio, MUSB_RXCSR,
679 						csr | MUSB_RXCSR_DMAMODE);
680 					musb_writew(epio, MUSB_RXCSR, csr);
681 
682 					transfer_size = min_t(unsigned int,
683 							request->length -
684 							request->actual,
685 							channel->max_len);
686 					musb_ep->dma->desired_mode = 1;
687 				} else {
688 					if (!musb_ep->hb_mult &&
689 						musb_ep->hw_ep->rx_double_buffered)
690 						csr |= MUSB_RXCSR_AUTOCLEAR;
691 					csr |= MUSB_RXCSR_DMAENAB;
692 					musb_writew(epio, MUSB_RXCSR, csr);
693 
694 					transfer_size = min(request->length - request->actual,
695 							(unsigned)fifo_count);
696 					musb_ep->dma->desired_mode = 0;
697 				}
698 
699 				use_dma = c->channel_program(
700 						channel,
701 						musb_ep->packet_sz,
702 						channel->desired_mode,
703 						request->dma
704 						+ request->actual,
705 						transfer_size);
706 
707 				if (use_dma)
708 					return;
709 			}
710 
711 			if ((musb_dma_ux500(musb)) &&
712 				(request->actual < request->length)) {
713 
714 				struct dma_controller *c;
715 				struct dma_channel *channel;
716 				unsigned int transfer_size = 0;
717 
718 				c = musb->dma_controller;
719 				channel = musb_ep->dma;
720 
721 				/* In case first packet is short */
722 				if (fifo_count < musb_ep->packet_sz)
723 					transfer_size = fifo_count;
724 				else if (request->short_not_ok)
725 					transfer_size =	min_t(unsigned int,
726 							request->length -
727 							request->actual,
728 							channel->max_len);
729 				else
730 					transfer_size = min_t(unsigned int,
731 							request->length -
732 							request->actual,
733 							(unsigned)fifo_count);
734 
735 				csr &= ~MUSB_RXCSR_DMAMODE;
736 				csr |= (MUSB_RXCSR_DMAENAB |
737 					MUSB_RXCSR_AUTOCLEAR);
738 
739 				musb_writew(epio, MUSB_RXCSR, csr);
740 
741 				if (transfer_size <= musb_ep->packet_sz) {
742 					musb_ep->dma->desired_mode = 0;
743 				} else {
744 					musb_ep->dma->desired_mode = 1;
745 					/* Mode must be set after DMAENAB */
746 					csr |= MUSB_RXCSR_DMAMODE;
747 					musb_writew(epio, MUSB_RXCSR, csr);
748 				}
749 
750 				if (c->channel_program(channel,
751 							musb_ep->packet_sz,
752 							channel->desired_mode,
753 							request->dma
754 							+ request->actual,
755 							transfer_size))
756 
757 					return;
758 			}
759 
760 			len = request->length - request->actual;
761 			musb_dbg(musb, "%s OUT/RX pio fifo %d/%d, maxpacket %d",
762 					musb_ep->end_point.name,
763 					fifo_count, len,
764 					musb_ep->packet_sz);
765 
766 			fifo_count = min_t(unsigned, len, fifo_count);
767 
768 			if (tusb_dma_omap(musb)) {
769 				struct dma_controller *c = musb->dma_controller;
770 				struct dma_channel *channel = musb_ep->dma;
771 				u32 dma_addr = request->dma + request->actual;
772 				int ret;
773 
774 				ret = c->channel_program(channel,
775 						musb_ep->packet_sz,
776 						channel->desired_mode,
777 						dma_addr,
778 						fifo_count);
779 				if (ret)
780 					return;
781 			}
782 
783 			/*
784 			 * Unmap the dma buffer back to cpu if dma channel
785 			 * programming fails. This buffer is mapped if the
786 			 * channel allocation is successful
787 			 */
788 			unmap_dma_buffer(req, musb);
789 
790 			/*
791 			 * Clear DMAENAB and AUTOCLEAR for the
792 			 * PIO mode transfer
793 			 */
794 			csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
795 			musb_writew(epio, MUSB_RXCSR, csr);
796 
797 buffer_aint_mapped:
798 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
799 					(request->buf + request->actual));
800 			request->actual += fifo_count;
801 
802 			/* REVISIT if we left anything in the fifo, flush
803 			 * it and report -EOVERFLOW
804 			 */
805 
806 			/* ack the read! */
807 			csr |= MUSB_RXCSR_P_WZC_BITS;
808 			csr &= ~MUSB_RXCSR_RXPKTRDY;
809 			musb_writew(epio, MUSB_RXCSR, csr);
810 		}
811 	}
812 
813 	/* reach the end or short packet detected */
814 	if (request->actual == request->length ||
815 	    fifo_count < musb_ep->packet_sz)
816 		musb_g_giveback(musb_ep, request, 0);
817 }
818 
819 /*
820  * Data ready for a request; called from IRQ
821  */
822 void musb_g_rx(struct musb *musb, u8 epnum)
823 {
824 	u16			csr;
825 	struct musb_request	*req;
826 	struct usb_request	*request;
827 	void __iomem		*mbase = musb->mregs;
828 	struct musb_ep		*musb_ep;
829 	void __iomem		*epio = musb->endpoints[epnum].regs;
830 	struct dma_channel	*dma;
831 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
832 
833 	if (hw_ep->is_shared_fifo)
834 		musb_ep = &hw_ep->ep_in;
835 	else
836 		musb_ep = &hw_ep->ep_out;
837 
838 	musb_ep_select(mbase, epnum);
839 
840 	req = next_request(musb_ep);
841 	if (!req)
842 		return;
843 
844 	trace_musb_req_rx(req);
845 	request = &req->request;
846 
847 	csr = musb_readw(epio, MUSB_RXCSR);
848 	dma = is_dma_capable() ? musb_ep->dma : NULL;
849 
850 	musb_dbg(musb, "<== %s, rxcsr %04x%s %p", musb_ep->end_point.name,
851 			csr, dma ? " (dma)" : "", request);
852 
853 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
854 		csr |= MUSB_RXCSR_P_WZC_BITS;
855 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
856 		musb_writew(epio, MUSB_RXCSR, csr);
857 		return;
858 	}
859 
860 	if (csr & MUSB_RXCSR_P_OVERRUN) {
861 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
862 		csr &= ~MUSB_RXCSR_P_OVERRUN;
863 		musb_writew(epio, MUSB_RXCSR, csr);
864 
865 		musb_dbg(musb, "%s iso overrun on %p", musb_ep->name, request);
866 		if (request->status == -EINPROGRESS)
867 			request->status = -EOVERFLOW;
868 	}
869 	if (csr & MUSB_RXCSR_INCOMPRX) {
870 		/* REVISIT not necessarily an error */
871 		musb_dbg(musb, "%s, incomprx", musb_ep->end_point.name);
872 	}
873 
874 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
875 		/* "should not happen"; likely RXPKTRDY pending for DMA */
876 		musb_dbg(musb, "%s busy, csr %04x",
877 			musb_ep->end_point.name, csr);
878 		return;
879 	}
880 
881 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
882 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
883 				| MUSB_RXCSR_DMAENAB
884 				| MUSB_RXCSR_DMAMODE);
885 		musb_writew(epio, MUSB_RXCSR,
886 			MUSB_RXCSR_P_WZC_BITS | csr);
887 
888 		request->actual += musb_ep->dma->actual_len;
889 
890 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
891 	defined(CONFIG_USB_UX500_DMA)
892 		/* Autoclear doesn't clear RxPktRdy for short packets */
893 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
894 				|| (dma->actual_len
895 					& (musb_ep->packet_sz - 1))) {
896 			/* ack the read! */
897 			csr &= ~MUSB_RXCSR_RXPKTRDY;
898 			musb_writew(epio, MUSB_RXCSR, csr);
899 		}
900 
901 		/* incomplete, and not short? wait for next IN packet */
902 		if ((request->actual < request->length)
903 				&& (musb_ep->dma->actual_len
904 					== musb_ep->packet_sz)) {
905 			/* In double buffer case, continue to unload fifo if
906  			 * there is Rx packet in FIFO.
907  			 **/
908 			csr = musb_readw(epio, MUSB_RXCSR);
909 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
910 				hw_ep->rx_double_buffered)
911 				goto exit;
912 			return;
913 		}
914 #endif
915 		musb_g_giveback(musb_ep, request, 0);
916 		/*
917 		 * In the giveback function the MUSB lock is
918 		 * released and acquired after sometime. During
919 		 * this time period the INDEX register could get
920 		 * changed by the gadget_queue function especially
921 		 * on SMP systems. Reselect the INDEX to be sure
922 		 * we are reading/modifying the right registers
923 		 */
924 		musb_ep_select(mbase, epnum);
925 
926 		req = next_request(musb_ep);
927 		if (!req)
928 			return;
929 	}
930 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
931 	defined(CONFIG_USB_UX500_DMA)
932 exit:
933 #endif
934 	/* Analyze request */
935 	rxstate(musb, req);
936 }
937 
938 /* ------------------------------------------------------------ */
939 
940 static int musb_gadget_enable(struct usb_ep *ep,
941 			const struct usb_endpoint_descriptor *desc)
942 {
943 	unsigned long		flags;
944 	struct musb_ep		*musb_ep;
945 	struct musb_hw_ep	*hw_ep;
946 	void __iomem		*regs;
947 	struct musb		*musb;
948 	void __iomem	*mbase;
949 	u8		epnum;
950 	u16		csr;
951 	unsigned	tmp;
952 	int		status = -EINVAL;
953 
954 	if (!ep || !desc)
955 		return -EINVAL;
956 
957 	musb_ep = to_musb_ep(ep);
958 	hw_ep = musb_ep->hw_ep;
959 	regs = hw_ep->regs;
960 	musb = musb_ep->musb;
961 	mbase = musb->mregs;
962 	epnum = musb_ep->current_epnum;
963 
964 	spin_lock_irqsave(&musb->lock, flags);
965 
966 	if (musb_ep->desc) {
967 		status = -EBUSY;
968 		goto fail;
969 	}
970 	musb_ep->type = usb_endpoint_type(desc);
971 
972 	/* check direction and (later) maxpacket size against endpoint */
973 	if (usb_endpoint_num(desc) != epnum)
974 		goto fail;
975 
976 	/* REVISIT this rules out high bandwidth periodic transfers */
977 	tmp = usb_endpoint_maxp_mult(desc) - 1;
978 	if (tmp) {
979 		int ok;
980 
981 		if (usb_endpoint_dir_in(desc))
982 			ok = musb->hb_iso_tx;
983 		else
984 			ok = musb->hb_iso_rx;
985 
986 		if (!ok) {
987 			musb_dbg(musb, "no support for high bandwidth ISO");
988 			goto fail;
989 		}
990 		musb_ep->hb_mult = tmp;
991 	} else {
992 		musb_ep->hb_mult = 0;
993 	}
994 
995 	musb_ep->packet_sz = usb_endpoint_maxp(desc);
996 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
997 
998 	/* enable the interrupts for the endpoint, set the endpoint
999 	 * packet size (or fail), set the mode, clear the fifo
1000 	 */
1001 	musb_ep_select(mbase, epnum);
1002 	if (usb_endpoint_dir_in(desc)) {
1003 
1004 		if (hw_ep->is_shared_fifo)
1005 			musb_ep->is_in = 1;
1006 		if (!musb_ep->is_in)
1007 			goto fail;
1008 
1009 		if (tmp > hw_ep->max_packet_sz_tx) {
1010 			musb_dbg(musb, "packet size beyond hardware FIFO size");
1011 			goto fail;
1012 		}
1013 
1014 		musb->intrtxe |= (1 << epnum);
1015 		musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
1016 
1017 		/* REVISIT if can_bulk_split(), use by updating "tmp";
1018 		 * likewise high bandwidth periodic tx
1019 		 */
1020 		/* Set TXMAXP with the FIFO size of the endpoint
1021 		 * to disable double buffering mode.
1022 		 */
1023 		if (musb->double_buffer_not_ok) {
1024 			musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
1025 		} else {
1026 			if (can_bulk_split(musb, musb_ep->type))
1027 				musb_ep->hb_mult = (hw_ep->max_packet_sz_tx /
1028 							musb_ep->packet_sz) - 1;
1029 			musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
1030 					| (musb_ep->hb_mult << 11));
1031 		}
1032 
1033 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
1034 		if (musb_readw(regs, MUSB_TXCSR)
1035 				& MUSB_TXCSR_FIFONOTEMPTY)
1036 			csr |= MUSB_TXCSR_FLUSHFIFO;
1037 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1038 			csr |= MUSB_TXCSR_P_ISO;
1039 
1040 		/* set twice in case of double buffering */
1041 		musb_writew(regs, MUSB_TXCSR, csr);
1042 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1043 		musb_writew(regs, MUSB_TXCSR, csr);
1044 
1045 	} else {
1046 
1047 		if (hw_ep->is_shared_fifo)
1048 			musb_ep->is_in = 0;
1049 		if (musb_ep->is_in)
1050 			goto fail;
1051 
1052 		if (tmp > hw_ep->max_packet_sz_rx) {
1053 			musb_dbg(musb, "packet size beyond hardware FIFO size");
1054 			goto fail;
1055 		}
1056 
1057 		musb->intrrxe |= (1 << epnum);
1058 		musb_writew(mbase, MUSB_INTRRXE, musb->intrrxe);
1059 
1060 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1061 		 * likewise high bandwidth periodic rx
1062 		 */
1063 		/* Set RXMAXP with the FIFO size of the endpoint
1064 		 * to disable double buffering mode.
1065 		 */
1066 		if (musb->double_buffer_not_ok)
1067 			musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_tx);
1068 		else
1069 			musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1070 					| (musb_ep->hb_mult << 11));
1071 
1072 		/* force shared fifo to OUT-only mode */
1073 		if (hw_ep->is_shared_fifo) {
1074 			csr = musb_readw(regs, MUSB_TXCSR);
1075 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1076 			musb_writew(regs, MUSB_TXCSR, csr);
1077 		}
1078 
1079 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1080 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1081 			csr |= MUSB_RXCSR_P_ISO;
1082 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1083 			csr |= MUSB_RXCSR_DISNYET;
1084 
1085 		/* set twice in case of double buffering */
1086 		musb_writew(regs, MUSB_RXCSR, csr);
1087 		musb_writew(regs, MUSB_RXCSR, csr);
1088 	}
1089 
1090 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1091 	 * for some reason you run out of channels here.
1092 	 */
1093 	if (is_dma_capable() && musb->dma_controller) {
1094 		struct dma_controller	*c = musb->dma_controller;
1095 
1096 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1097 				(desc->bEndpointAddress & USB_DIR_IN));
1098 	} else
1099 		musb_ep->dma = NULL;
1100 
1101 	musb_ep->desc = desc;
1102 	musb_ep->busy = 0;
1103 	musb_ep->wedged = 0;
1104 	status = 0;
1105 
1106 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1107 			musb_driver_name, musb_ep->end_point.name,
1108 			({ char *s; switch (musb_ep->type) {
1109 			case USB_ENDPOINT_XFER_BULK:	s = "bulk"; break;
1110 			case USB_ENDPOINT_XFER_INT:	s = "int"; break;
1111 			default:			s = "iso"; break;
1112 			} s; }),
1113 			musb_ep->is_in ? "IN" : "OUT",
1114 			musb_ep->dma ? "dma, " : "",
1115 			musb_ep->packet_sz);
1116 
1117 	schedule_delayed_work(&musb->irq_work, 0);
1118 
1119 fail:
1120 	spin_unlock_irqrestore(&musb->lock, flags);
1121 	return status;
1122 }
1123 
1124 /*
1125  * Disable an endpoint flushing all requests queued.
1126  */
1127 static int musb_gadget_disable(struct usb_ep *ep)
1128 {
1129 	unsigned long	flags;
1130 	struct musb	*musb;
1131 	u8		epnum;
1132 	struct musb_ep	*musb_ep;
1133 	void __iomem	*epio;
1134 	int		status = 0;
1135 
1136 	musb_ep = to_musb_ep(ep);
1137 	musb = musb_ep->musb;
1138 	epnum = musb_ep->current_epnum;
1139 	epio = musb->endpoints[epnum].regs;
1140 
1141 	spin_lock_irqsave(&musb->lock, flags);
1142 	musb_ep_select(musb->mregs, epnum);
1143 
1144 	/* zero the endpoint sizes */
1145 	if (musb_ep->is_in) {
1146 		musb->intrtxe &= ~(1 << epnum);
1147 		musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
1148 		musb_writew(epio, MUSB_TXMAXP, 0);
1149 	} else {
1150 		musb->intrrxe &= ~(1 << epnum);
1151 		musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
1152 		musb_writew(epio, MUSB_RXMAXP, 0);
1153 	}
1154 
1155 	/* abort all pending DMA and requests */
1156 	nuke(musb_ep, -ESHUTDOWN);
1157 
1158 	musb_ep->desc = NULL;
1159 	musb_ep->end_point.desc = NULL;
1160 
1161 	schedule_delayed_work(&musb->irq_work, 0);
1162 
1163 	spin_unlock_irqrestore(&(musb->lock), flags);
1164 
1165 	musb_dbg(musb, "%s", musb_ep->end_point.name);
1166 
1167 	return status;
1168 }
1169 
1170 /*
1171  * Allocate a request for an endpoint.
1172  * Reused by ep0 code.
1173  */
1174 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1175 {
1176 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1177 	struct musb_request	*request = NULL;
1178 
1179 	request = kzalloc(sizeof *request, gfp_flags);
1180 	if (!request)
1181 		return NULL;
1182 
1183 	request->request.dma = DMA_ADDR_INVALID;
1184 	request->epnum = musb_ep->current_epnum;
1185 	request->ep = musb_ep;
1186 
1187 	trace_musb_req_alloc(request);
1188 	return &request->request;
1189 }
1190 
1191 /*
1192  * Free a request
1193  * Reused by ep0 code.
1194  */
1195 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1196 {
1197 	struct musb_request *request = to_musb_request(req);
1198 
1199 	trace_musb_req_free(request);
1200 	kfree(request);
1201 }
1202 
1203 static LIST_HEAD(buffers);
1204 
1205 struct free_record {
1206 	struct list_head	list;
1207 	struct device		*dev;
1208 	unsigned		bytes;
1209 	dma_addr_t		dma;
1210 };
1211 
1212 /*
1213  * Context: controller locked, IRQs blocked.
1214  */
1215 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1216 {
1217 	trace_musb_req_start(req);
1218 	musb_ep_select(musb->mregs, req->epnum);
1219 	if (req->tx)
1220 		txstate(musb, req);
1221 	else
1222 		rxstate(musb, req);
1223 }
1224 
1225 static int musb_ep_restart_resume_work(struct musb *musb, void *data)
1226 {
1227 	struct musb_request *req = data;
1228 
1229 	musb_ep_restart(musb, req);
1230 
1231 	return 0;
1232 }
1233 
1234 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1235 			gfp_t gfp_flags)
1236 {
1237 	struct musb_ep		*musb_ep;
1238 	struct musb_request	*request;
1239 	struct musb		*musb;
1240 	int			status;
1241 	unsigned long		lockflags;
1242 
1243 	if (!ep || !req)
1244 		return -EINVAL;
1245 	if (!req->buf)
1246 		return -ENODATA;
1247 
1248 	musb_ep = to_musb_ep(ep);
1249 	musb = musb_ep->musb;
1250 
1251 	request = to_musb_request(req);
1252 	request->musb = musb;
1253 
1254 	if (request->ep != musb_ep)
1255 		return -EINVAL;
1256 
1257 	status = pm_runtime_get(musb->controller);
1258 	if ((status != -EINPROGRESS) && status < 0) {
1259 		dev_err(musb->controller,
1260 			"pm runtime get failed in %s\n",
1261 			__func__);
1262 		pm_runtime_put_noidle(musb->controller);
1263 
1264 		return status;
1265 	}
1266 	status = 0;
1267 
1268 	trace_musb_req_enq(request);
1269 
1270 	/* request is mine now... */
1271 	request->request.actual = 0;
1272 	request->request.status = -EINPROGRESS;
1273 	request->epnum = musb_ep->current_epnum;
1274 	request->tx = musb_ep->is_in;
1275 
1276 	map_dma_buffer(request, musb, musb_ep);
1277 
1278 	spin_lock_irqsave(&musb->lock, lockflags);
1279 
1280 	/* don't queue if the ep is down */
1281 	if (!musb_ep->desc) {
1282 		musb_dbg(musb, "req %p queued to %s while ep %s",
1283 				req, ep->name, "disabled");
1284 		status = -ESHUTDOWN;
1285 		unmap_dma_buffer(request, musb);
1286 		goto unlock;
1287 	}
1288 
1289 	/* add request to the list */
1290 	list_add_tail(&request->list, &musb_ep->req_list);
1291 
1292 	/* it this is the head of the queue, start i/o ... */
1293 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next) {
1294 		status = musb_queue_resume_work(musb,
1295 						musb_ep_restart_resume_work,
1296 						request);
1297 		if (status < 0)
1298 			dev_err(musb->controller, "%s resume work: %i\n",
1299 				__func__, status);
1300 	}
1301 
1302 unlock:
1303 	spin_unlock_irqrestore(&musb->lock, lockflags);
1304 	pm_runtime_mark_last_busy(musb->controller);
1305 	pm_runtime_put_autosuspend(musb->controller);
1306 
1307 	return status;
1308 }
1309 
1310 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1311 {
1312 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1313 	struct musb_request	*req = to_musb_request(request);
1314 	struct musb_request	*r;
1315 	unsigned long		flags;
1316 	int			status = 0;
1317 	struct musb		*musb = musb_ep->musb;
1318 
1319 	if (!ep || !request || req->ep != musb_ep)
1320 		return -EINVAL;
1321 
1322 	trace_musb_req_deq(req);
1323 
1324 	spin_lock_irqsave(&musb->lock, flags);
1325 
1326 	list_for_each_entry(r, &musb_ep->req_list, list) {
1327 		if (r == req)
1328 			break;
1329 	}
1330 	if (r != req) {
1331 		dev_err(musb->controller, "request %p not queued to %s\n",
1332 				request, ep->name);
1333 		status = -EINVAL;
1334 		goto done;
1335 	}
1336 
1337 	/* if the hardware doesn't have the request, easy ... */
1338 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1339 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1340 
1341 	/* ... else abort the dma transfer ... */
1342 	else if (is_dma_capable() && musb_ep->dma) {
1343 		struct dma_controller	*c = musb->dma_controller;
1344 
1345 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1346 		if (c->channel_abort)
1347 			status = c->channel_abort(musb_ep->dma);
1348 		else
1349 			status = -EBUSY;
1350 		if (status == 0)
1351 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1352 	} else {
1353 		/* NOTE: by sticking to easily tested hardware/driver states,
1354 		 * we leave counting of in-flight packets imprecise.
1355 		 */
1356 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1357 	}
1358 
1359 done:
1360 	spin_unlock_irqrestore(&musb->lock, flags);
1361 	return status;
1362 }
1363 
1364 /*
1365  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1366  * data but will queue requests.
1367  *
1368  * exported to ep0 code
1369  */
1370 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1371 {
1372 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1373 	u8			epnum = musb_ep->current_epnum;
1374 	struct musb		*musb = musb_ep->musb;
1375 	void __iomem		*epio = musb->endpoints[epnum].regs;
1376 	void __iomem		*mbase;
1377 	unsigned long		flags;
1378 	u16			csr;
1379 	struct musb_request	*request;
1380 	int			status = 0;
1381 
1382 	if (!ep)
1383 		return -EINVAL;
1384 	mbase = musb->mregs;
1385 
1386 	spin_lock_irqsave(&musb->lock, flags);
1387 
1388 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1389 		status = -EINVAL;
1390 		goto done;
1391 	}
1392 
1393 	musb_ep_select(mbase, epnum);
1394 
1395 	request = next_request(musb_ep);
1396 	if (value) {
1397 		if (request) {
1398 			musb_dbg(musb, "request in progress, cannot halt %s",
1399 			    ep->name);
1400 			status = -EAGAIN;
1401 			goto done;
1402 		}
1403 		/* Cannot portably stall with non-empty FIFO */
1404 		if (musb_ep->is_in) {
1405 			csr = musb_readw(epio, MUSB_TXCSR);
1406 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1407 				musb_dbg(musb, "FIFO busy, cannot halt %s",
1408 						ep->name);
1409 				status = -EAGAIN;
1410 				goto done;
1411 			}
1412 		}
1413 	} else
1414 		musb_ep->wedged = 0;
1415 
1416 	/* set/clear the stall and toggle bits */
1417 	musb_dbg(musb, "%s: %s stall", ep->name, value ? "set" : "clear");
1418 	if (musb_ep->is_in) {
1419 		csr = musb_readw(epio, MUSB_TXCSR);
1420 		csr |= MUSB_TXCSR_P_WZC_BITS
1421 			| MUSB_TXCSR_CLRDATATOG;
1422 		if (value)
1423 			csr |= MUSB_TXCSR_P_SENDSTALL;
1424 		else
1425 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1426 				| MUSB_TXCSR_P_SENTSTALL);
1427 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1428 		musb_writew(epio, MUSB_TXCSR, csr);
1429 	} else {
1430 		csr = musb_readw(epio, MUSB_RXCSR);
1431 		csr |= MUSB_RXCSR_P_WZC_BITS
1432 			| MUSB_RXCSR_FLUSHFIFO
1433 			| MUSB_RXCSR_CLRDATATOG;
1434 		if (value)
1435 			csr |= MUSB_RXCSR_P_SENDSTALL;
1436 		else
1437 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1438 				| MUSB_RXCSR_P_SENTSTALL);
1439 		musb_writew(epio, MUSB_RXCSR, csr);
1440 	}
1441 
1442 	/* maybe start the first request in the queue */
1443 	if (!musb_ep->busy && !value && request) {
1444 		musb_dbg(musb, "restarting the request");
1445 		musb_ep_restart(musb, request);
1446 	}
1447 
1448 done:
1449 	spin_unlock_irqrestore(&musb->lock, flags);
1450 	return status;
1451 }
1452 
1453 /*
1454  * Sets the halt feature with the clear requests ignored
1455  */
1456 static int musb_gadget_set_wedge(struct usb_ep *ep)
1457 {
1458 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1459 
1460 	if (!ep)
1461 		return -EINVAL;
1462 
1463 	musb_ep->wedged = 1;
1464 
1465 	return usb_ep_set_halt(ep);
1466 }
1467 
1468 static int musb_gadget_fifo_status(struct usb_ep *ep)
1469 {
1470 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1471 	void __iomem		*epio = musb_ep->hw_ep->regs;
1472 	int			retval = -EINVAL;
1473 
1474 	if (musb_ep->desc && !musb_ep->is_in) {
1475 		struct musb		*musb = musb_ep->musb;
1476 		int			epnum = musb_ep->current_epnum;
1477 		void __iomem		*mbase = musb->mregs;
1478 		unsigned long		flags;
1479 
1480 		spin_lock_irqsave(&musb->lock, flags);
1481 
1482 		musb_ep_select(mbase, epnum);
1483 		/* FIXME return zero unless RXPKTRDY is set */
1484 		retval = musb_readw(epio, MUSB_RXCOUNT);
1485 
1486 		spin_unlock_irqrestore(&musb->lock, flags);
1487 	}
1488 	return retval;
1489 }
1490 
1491 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1492 {
1493 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1494 	struct musb	*musb = musb_ep->musb;
1495 	u8		epnum = musb_ep->current_epnum;
1496 	void __iomem	*epio = musb->endpoints[epnum].regs;
1497 	void __iomem	*mbase;
1498 	unsigned long	flags;
1499 	u16		csr;
1500 
1501 	mbase = musb->mregs;
1502 
1503 	spin_lock_irqsave(&musb->lock, flags);
1504 	musb_ep_select(mbase, (u8) epnum);
1505 
1506 	/* disable interrupts */
1507 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe & ~(1 << epnum));
1508 
1509 	if (musb_ep->is_in) {
1510 		csr = musb_readw(epio, MUSB_TXCSR);
1511 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1512 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1513 			/*
1514 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1515 			 * to interrupt current FIFO loading, but not flushing
1516 			 * the already loaded ones.
1517 			 */
1518 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1519 			musb_writew(epio, MUSB_TXCSR, csr);
1520 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1521 			musb_writew(epio, MUSB_TXCSR, csr);
1522 		}
1523 	} else {
1524 		csr = musb_readw(epio, MUSB_RXCSR);
1525 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1526 		musb_writew(epio, MUSB_RXCSR, csr);
1527 		musb_writew(epio, MUSB_RXCSR, csr);
1528 	}
1529 
1530 	/* re-enable interrupt */
1531 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
1532 	spin_unlock_irqrestore(&musb->lock, flags);
1533 }
1534 
1535 static const struct usb_ep_ops musb_ep_ops = {
1536 	.enable		= musb_gadget_enable,
1537 	.disable	= musb_gadget_disable,
1538 	.alloc_request	= musb_alloc_request,
1539 	.free_request	= musb_free_request,
1540 	.queue		= musb_gadget_queue,
1541 	.dequeue	= musb_gadget_dequeue,
1542 	.set_halt	= musb_gadget_set_halt,
1543 	.set_wedge	= musb_gadget_set_wedge,
1544 	.fifo_status	= musb_gadget_fifo_status,
1545 	.fifo_flush	= musb_gadget_fifo_flush
1546 };
1547 
1548 /* ----------------------------------------------------------------------- */
1549 
1550 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1551 {
1552 	struct musb	*musb = gadget_to_musb(gadget);
1553 
1554 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1555 }
1556 
1557 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1558 {
1559 	struct musb	*musb = gadget_to_musb(gadget);
1560 	void __iomem	*mregs = musb->mregs;
1561 	unsigned long	flags;
1562 	int		status = -EINVAL;
1563 	u8		power, devctl;
1564 	int		retries;
1565 
1566 	spin_lock_irqsave(&musb->lock, flags);
1567 
1568 	switch (musb->xceiv->otg->state) {
1569 	case OTG_STATE_B_PERIPHERAL:
1570 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1571 		 * that's part of the standard usb 1.1 state machine, and
1572 		 * doesn't affect OTG transitions.
1573 		 */
1574 		if (musb->may_wakeup && musb->is_suspended)
1575 			break;
1576 		goto done;
1577 	case OTG_STATE_B_IDLE:
1578 		/* Start SRP ... OTG not required. */
1579 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1580 		musb_dbg(musb, "Sending SRP: devctl: %02x", devctl);
1581 		devctl |= MUSB_DEVCTL_SESSION;
1582 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1583 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1584 		retries = 100;
1585 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1586 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1587 			if (retries-- < 1)
1588 				break;
1589 		}
1590 		retries = 10000;
1591 		while (devctl & MUSB_DEVCTL_SESSION) {
1592 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1593 			if (retries-- < 1)
1594 				break;
1595 		}
1596 
1597 		spin_unlock_irqrestore(&musb->lock, flags);
1598 		otg_start_srp(musb->xceiv->otg);
1599 		spin_lock_irqsave(&musb->lock, flags);
1600 
1601 		/* Block idling for at least 1s */
1602 		musb_platform_try_idle(musb,
1603 			jiffies + msecs_to_jiffies(1 * HZ));
1604 
1605 		status = 0;
1606 		goto done;
1607 	default:
1608 		musb_dbg(musb, "Unhandled wake: %s",
1609 			usb_otg_state_string(musb->xceiv->otg->state));
1610 		goto done;
1611 	}
1612 
1613 	status = 0;
1614 
1615 	power = musb_readb(mregs, MUSB_POWER);
1616 	power |= MUSB_POWER_RESUME;
1617 	musb_writeb(mregs, MUSB_POWER, power);
1618 	musb_dbg(musb, "issue wakeup");
1619 
1620 	/* FIXME do this next chunk in a timer callback, no udelay */
1621 	mdelay(2);
1622 
1623 	power = musb_readb(mregs, MUSB_POWER);
1624 	power &= ~MUSB_POWER_RESUME;
1625 	musb_writeb(mregs, MUSB_POWER, power);
1626 done:
1627 	spin_unlock_irqrestore(&musb->lock, flags);
1628 	return status;
1629 }
1630 
1631 static int
1632 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1633 {
1634 	gadget->is_selfpowered = !!is_selfpowered;
1635 	return 0;
1636 }
1637 
1638 static void musb_pullup(struct musb *musb, int is_on)
1639 {
1640 	u8 power;
1641 
1642 	power = musb_readb(musb->mregs, MUSB_POWER);
1643 	if (is_on)
1644 		power |= MUSB_POWER_SOFTCONN;
1645 	else
1646 		power &= ~MUSB_POWER_SOFTCONN;
1647 
1648 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1649 
1650 	musb_dbg(musb, "gadget D+ pullup %s",
1651 		is_on ? "on" : "off");
1652 	musb_writeb(musb->mregs, MUSB_POWER, power);
1653 }
1654 
1655 #if 0
1656 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1657 {
1658 	musb_dbg(musb, "<= %s =>\n", __func__);
1659 
1660 	/*
1661 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1662 	 * though that can clear it), just musb_pullup().
1663 	 */
1664 
1665 	return -EINVAL;
1666 }
1667 #endif
1668 
1669 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1670 {
1671 	struct musb	*musb = gadget_to_musb(gadget);
1672 
1673 	if (!musb->xceiv->set_power)
1674 		return -EOPNOTSUPP;
1675 	return usb_phy_set_power(musb->xceiv, mA);
1676 }
1677 
1678 static void musb_gadget_work(struct work_struct *work)
1679 {
1680 	struct musb *musb;
1681 	unsigned long flags;
1682 
1683 	musb = container_of(work, struct musb, gadget_work.work);
1684 	pm_runtime_get_sync(musb->controller);
1685 	spin_lock_irqsave(&musb->lock, flags);
1686 	musb_pullup(musb, musb->softconnect);
1687 	spin_unlock_irqrestore(&musb->lock, flags);
1688 	pm_runtime_mark_last_busy(musb->controller);
1689 	pm_runtime_put_autosuspend(musb->controller);
1690 }
1691 
1692 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1693 {
1694 	struct musb	*musb = gadget_to_musb(gadget);
1695 	unsigned long	flags;
1696 
1697 	is_on = !!is_on;
1698 
1699 	/* NOTE: this assumes we are sensing vbus; we'd rather
1700 	 * not pullup unless the B-session is active.
1701 	 */
1702 	spin_lock_irqsave(&musb->lock, flags);
1703 	if (is_on != musb->softconnect) {
1704 		musb->softconnect = is_on;
1705 		schedule_delayed_work(&musb->gadget_work, 0);
1706 	}
1707 	spin_unlock_irqrestore(&musb->lock, flags);
1708 
1709 	return 0;
1710 }
1711 
1712 #ifdef CONFIG_BLACKFIN
1713 static struct usb_ep *musb_match_ep(struct usb_gadget *g,
1714 		struct usb_endpoint_descriptor *desc,
1715 		struct usb_ss_ep_comp_descriptor *ep_comp)
1716 {
1717 	struct usb_ep *ep = NULL;
1718 
1719 	switch (usb_endpoint_type(desc)) {
1720 	case USB_ENDPOINT_XFER_ISOC:
1721 	case USB_ENDPOINT_XFER_BULK:
1722 		if (usb_endpoint_dir_in(desc))
1723 			ep = gadget_find_ep_by_name(g, "ep5in");
1724 		else
1725 			ep = gadget_find_ep_by_name(g, "ep6out");
1726 		break;
1727 	case USB_ENDPOINT_XFER_INT:
1728 		if (usb_endpoint_dir_in(desc))
1729 			ep = gadget_find_ep_by_name(g, "ep1in");
1730 		else
1731 			ep = gadget_find_ep_by_name(g, "ep2out");
1732 		break;
1733 	default:
1734 		break;
1735 	}
1736 
1737 	if (ep && usb_gadget_ep_match_desc(g, ep, desc, ep_comp))
1738 		return ep;
1739 
1740 	return NULL;
1741 }
1742 #else
1743 #define musb_match_ep NULL
1744 #endif
1745 
1746 static int musb_gadget_start(struct usb_gadget *g,
1747 		struct usb_gadget_driver *driver);
1748 static int musb_gadget_stop(struct usb_gadget *g);
1749 
1750 static const struct usb_gadget_ops musb_gadget_operations = {
1751 	.get_frame		= musb_gadget_get_frame,
1752 	.wakeup			= musb_gadget_wakeup,
1753 	.set_selfpowered	= musb_gadget_set_self_powered,
1754 	/* .vbus_session		= musb_gadget_vbus_session, */
1755 	.vbus_draw		= musb_gadget_vbus_draw,
1756 	.pullup			= musb_gadget_pullup,
1757 	.udc_start		= musb_gadget_start,
1758 	.udc_stop		= musb_gadget_stop,
1759 	.match_ep		= musb_match_ep,
1760 };
1761 
1762 /* ----------------------------------------------------------------------- */
1763 
1764 /* Registration */
1765 
1766 /* Only this registration code "knows" the rule (from USB standards)
1767  * about there being only one external upstream port.  It assumes
1768  * all peripheral ports are external...
1769  */
1770 
1771 static void
1772 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1773 {
1774 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1775 
1776 	memset(ep, 0, sizeof *ep);
1777 
1778 	ep->current_epnum = epnum;
1779 	ep->musb = musb;
1780 	ep->hw_ep = hw_ep;
1781 	ep->is_in = is_in;
1782 
1783 	INIT_LIST_HEAD(&ep->req_list);
1784 
1785 	sprintf(ep->name, "ep%d%s", epnum,
1786 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1787 				is_in ? "in" : "out"));
1788 	ep->end_point.name = ep->name;
1789 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1790 	if (!epnum) {
1791 		usb_ep_set_maxpacket_limit(&ep->end_point, 64);
1792 		ep->end_point.caps.type_control = true;
1793 		ep->end_point.ops = &musb_g_ep0_ops;
1794 		musb->g.ep0 = &ep->end_point;
1795 	} else {
1796 		if (is_in)
1797 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_tx);
1798 		else
1799 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_rx);
1800 		ep->end_point.caps.type_iso = true;
1801 		ep->end_point.caps.type_bulk = true;
1802 		ep->end_point.caps.type_int = true;
1803 		ep->end_point.ops = &musb_ep_ops;
1804 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1805 	}
1806 
1807 	if (!epnum || hw_ep->is_shared_fifo) {
1808 		ep->end_point.caps.dir_in = true;
1809 		ep->end_point.caps.dir_out = true;
1810 	} else if (is_in)
1811 		ep->end_point.caps.dir_in = true;
1812 	else
1813 		ep->end_point.caps.dir_out = true;
1814 }
1815 
1816 /*
1817  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1818  * to the rest of the driver state.
1819  */
1820 static inline void musb_g_init_endpoints(struct musb *musb)
1821 {
1822 	u8			epnum;
1823 	struct musb_hw_ep	*hw_ep;
1824 	unsigned		count = 0;
1825 
1826 	/* initialize endpoint list just once */
1827 	INIT_LIST_HEAD(&(musb->g.ep_list));
1828 
1829 	for (epnum = 0, hw_ep = musb->endpoints;
1830 			epnum < musb->nr_endpoints;
1831 			epnum++, hw_ep++) {
1832 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1833 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1834 			count++;
1835 		} else {
1836 			if (hw_ep->max_packet_sz_tx) {
1837 				init_peripheral_ep(musb, &hw_ep->ep_in,
1838 							epnum, 1);
1839 				count++;
1840 			}
1841 			if (hw_ep->max_packet_sz_rx) {
1842 				init_peripheral_ep(musb, &hw_ep->ep_out,
1843 							epnum, 0);
1844 				count++;
1845 			}
1846 		}
1847 	}
1848 }
1849 
1850 /* called once during driver setup to initialize and link into
1851  * the driver model; memory is zeroed.
1852  */
1853 int musb_gadget_setup(struct musb *musb)
1854 {
1855 	int status;
1856 
1857 	/* REVISIT minor race:  if (erroneously) setting up two
1858 	 * musb peripherals at the same time, only the bus lock
1859 	 * is probably held.
1860 	 */
1861 
1862 	musb->g.ops = &musb_gadget_operations;
1863 	musb->g.max_speed = USB_SPEED_HIGH;
1864 	musb->g.speed = USB_SPEED_UNKNOWN;
1865 
1866 	MUSB_DEV_MODE(musb);
1867 	musb->xceiv->otg->default_a = 0;
1868 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1869 
1870 	/* this "gadget" abstracts/virtualizes the controller */
1871 	musb->g.name = musb_driver_name;
1872 #if IS_ENABLED(CONFIG_USB_MUSB_DUAL_ROLE)
1873 	musb->g.is_otg = 1;
1874 #elif IS_ENABLED(CONFIG_USB_MUSB_GADGET)
1875 	musb->g.is_otg = 0;
1876 #endif
1877 	INIT_DELAYED_WORK(&musb->gadget_work, musb_gadget_work);
1878 	musb_g_init_endpoints(musb);
1879 
1880 	musb->is_active = 0;
1881 	musb_platform_try_idle(musb, 0);
1882 
1883 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1884 	if (status)
1885 		goto err;
1886 
1887 	return 0;
1888 err:
1889 	musb->g.dev.parent = NULL;
1890 	device_unregister(&musb->g.dev);
1891 	return status;
1892 }
1893 
1894 void musb_gadget_cleanup(struct musb *musb)
1895 {
1896 	if (musb->port_mode == MUSB_PORT_MODE_HOST)
1897 		return;
1898 
1899 	cancel_delayed_work_sync(&musb->gadget_work);
1900 	usb_del_gadget_udc(&musb->g);
1901 }
1902 
1903 /*
1904  * Register the gadget driver. Used by gadget drivers when
1905  * registering themselves with the controller.
1906  *
1907  * -EINVAL something went wrong (not driver)
1908  * -EBUSY another gadget is already using the controller
1909  * -ENOMEM no memory to perform the operation
1910  *
1911  * @param driver the gadget driver
1912  * @return <0 if error, 0 if everything is fine
1913  */
1914 static int musb_gadget_start(struct usb_gadget *g,
1915 		struct usb_gadget_driver *driver)
1916 {
1917 	struct musb		*musb = gadget_to_musb(g);
1918 	struct usb_otg		*otg = musb->xceiv->otg;
1919 	unsigned long		flags;
1920 	int			retval = 0;
1921 
1922 	if (driver->max_speed < USB_SPEED_HIGH) {
1923 		retval = -EINVAL;
1924 		goto err;
1925 	}
1926 
1927 	pm_runtime_get_sync(musb->controller);
1928 
1929 	musb->softconnect = 0;
1930 	musb->gadget_driver = driver;
1931 
1932 	spin_lock_irqsave(&musb->lock, flags);
1933 	musb->is_active = 1;
1934 
1935 	otg_set_peripheral(otg, &musb->g);
1936 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1937 	spin_unlock_irqrestore(&musb->lock, flags);
1938 
1939 	musb_start(musb);
1940 
1941 	/* REVISIT:  funcall to other code, which also
1942 	 * handles power budgeting ... this way also
1943 	 * ensures HdrcStart is indirectly called.
1944 	 */
1945 	if (musb->xceiv->last_event == USB_EVENT_ID)
1946 		musb_platform_set_vbus(musb, 1);
1947 
1948 	pm_runtime_mark_last_busy(musb->controller);
1949 	pm_runtime_put_autosuspend(musb->controller);
1950 
1951 	return 0;
1952 
1953 err:
1954 	return retval;
1955 }
1956 
1957 /*
1958  * Unregister the gadget driver. Used by gadget drivers when
1959  * unregistering themselves from the controller.
1960  *
1961  * @param driver the gadget driver to unregister
1962  */
1963 static int musb_gadget_stop(struct usb_gadget *g)
1964 {
1965 	struct musb	*musb = gadget_to_musb(g);
1966 	unsigned long	flags;
1967 
1968 	pm_runtime_get_sync(musb->controller);
1969 
1970 	/*
1971 	 * REVISIT always use otg_set_peripheral() here too;
1972 	 * this needs to shut down the OTG engine.
1973 	 */
1974 
1975 	spin_lock_irqsave(&musb->lock, flags);
1976 
1977 	musb_hnp_stop(musb);
1978 
1979 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1980 
1981 	musb->xceiv->otg->state = OTG_STATE_UNDEFINED;
1982 	musb_stop(musb);
1983 	otg_set_peripheral(musb->xceiv->otg, NULL);
1984 
1985 	musb->is_active = 0;
1986 	musb->gadget_driver = NULL;
1987 	musb_platform_try_idle(musb, 0);
1988 	spin_unlock_irqrestore(&musb->lock, flags);
1989 
1990 	/*
1991 	 * FIXME we need to be able to register another
1992 	 * gadget driver here and have everything work;
1993 	 * that currently misbehaves.
1994 	 */
1995 
1996 	/* Force check of devctl register for PM runtime */
1997 	schedule_delayed_work(&musb->irq_work, 0);
1998 
1999 	pm_runtime_mark_last_busy(musb->controller);
2000 	pm_runtime_put_autosuspend(musb->controller);
2001 
2002 	return 0;
2003 }
2004 
2005 /* ----------------------------------------------------------------------- */
2006 
2007 /* lifecycle operations called through plat_uds.c */
2008 
2009 void musb_g_resume(struct musb *musb)
2010 {
2011 	musb->is_suspended = 0;
2012 	switch (musb->xceiv->otg->state) {
2013 	case OTG_STATE_B_IDLE:
2014 		break;
2015 	case OTG_STATE_B_WAIT_ACON:
2016 	case OTG_STATE_B_PERIPHERAL:
2017 		musb->is_active = 1;
2018 		if (musb->gadget_driver && musb->gadget_driver->resume) {
2019 			spin_unlock(&musb->lock);
2020 			musb->gadget_driver->resume(&musb->g);
2021 			spin_lock(&musb->lock);
2022 		}
2023 		break;
2024 	default:
2025 		WARNING("unhandled RESUME transition (%s)\n",
2026 				usb_otg_state_string(musb->xceiv->otg->state));
2027 	}
2028 }
2029 
2030 /* called when SOF packets stop for 3+ msec */
2031 void musb_g_suspend(struct musb *musb)
2032 {
2033 	u8	devctl;
2034 
2035 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2036 	musb_dbg(musb, "musb_g_suspend: devctl %02x", devctl);
2037 
2038 	switch (musb->xceiv->otg->state) {
2039 	case OTG_STATE_B_IDLE:
2040 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2041 			musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2042 		break;
2043 	case OTG_STATE_B_PERIPHERAL:
2044 		musb->is_suspended = 1;
2045 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
2046 			spin_unlock(&musb->lock);
2047 			musb->gadget_driver->suspend(&musb->g);
2048 			spin_lock(&musb->lock);
2049 		}
2050 		break;
2051 	default:
2052 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
2053 		 * A_PERIPHERAL may need care too
2054 		 */
2055 		WARNING("unhandled SUSPEND transition (%s)",
2056 				usb_otg_state_string(musb->xceiv->otg->state));
2057 	}
2058 }
2059 
2060 /* Called during SRP */
2061 void musb_g_wakeup(struct musb *musb)
2062 {
2063 	musb_gadget_wakeup(&musb->g);
2064 }
2065 
2066 /* called when VBUS drops below session threshold, and in other cases */
2067 void musb_g_disconnect(struct musb *musb)
2068 {
2069 	void __iomem	*mregs = musb->mregs;
2070 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
2071 
2072 	musb_dbg(musb, "musb_g_disconnect: devctl %02x", devctl);
2073 
2074 	/* clear HR */
2075 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
2076 
2077 	/* don't draw vbus until new b-default session */
2078 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2079 
2080 	musb->g.speed = USB_SPEED_UNKNOWN;
2081 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
2082 		spin_unlock(&musb->lock);
2083 		musb->gadget_driver->disconnect(&musb->g);
2084 		spin_lock(&musb->lock);
2085 	}
2086 
2087 	switch (musb->xceiv->otg->state) {
2088 	default:
2089 		musb_dbg(musb, "Unhandled disconnect %s, setting a_idle",
2090 			usb_otg_state_string(musb->xceiv->otg->state));
2091 		musb->xceiv->otg->state = OTG_STATE_A_IDLE;
2092 		MUSB_HST_MODE(musb);
2093 		break;
2094 	case OTG_STATE_A_PERIPHERAL:
2095 		musb->xceiv->otg->state = OTG_STATE_A_WAIT_BCON;
2096 		MUSB_HST_MODE(musb);
2097 		break;
2098 	case OTG_STATE_B_WAIT_ACON:
2099 	case OTG_STATE_B_HOST:
2100 	case OTG_STATE_B_PERIPHERAL:
2101 	case OTG_STATE_B_IDLE:
2102 		musb->xceiv->otg->state = OTG_STATE_B_IDLE;
2103 		break;
2104 	case OTG_STATE_B_SRP_INIT:
2105 		break;
2106 	}
2107 
2108 	musb->is_active = 0;
2109 }
2110 
2111 void musb_g_reset(struct musb *musb)
2112 __releases(musb->lock)
2113 __acquires(musb->lock)
2114 {
2115 	void __iomem	*mbase = musb->mregs;
2116 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2117 	u8		power;
2118 
2119 	musb_dbg(musb, "<== %s driver '%s'",
2120 			(devctl & MUSB_DEVCTL_BDEVICE)
2121 				? "B-Device" : "A-Device",
2122 			musb->gadget_driver
2123 				? musb->gadget_driver->driver.name
2124 				: NULL
2125 			);
2126 
2127 	/* report reset, if we didn't already (flushing EP state) */
2128 	if (musb->gadget_driver && musb->g.speed != USB_SPEED_UNKNOWN) {
2129 		spin_unlock(&musb->lock);
2130 		usb_gadget_udc_reset(&musb->g, musb->gadget_driver);
2131 		spin_lock(&musb->lock);
2132 	}
2133 
2134 	/* clear HR */
2135 	else if (devctl & MUSB_DEVCTL_HR)
2136 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2137 
2138 
2139 	/* what speed did we negotiate? */
2140 	power = musb_readb(mbase, MUSB_POWER);
2141 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2142 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2143 
2144 	/* start in USB_STATE_DEFAULT */
2145 	musb->is_active = 1;
2146 	musb->is_suspended = 0;
2147 	MUSB_DEV_MODE(musb);
2148 	musb->address = 0;
2149 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2150 
2151 	musb->may_wakeup = 0;
2152 	musb->g.b_hnp_enable = 0;
2153 	musb->g.a_alt_hnp_support = 0;
2154 	musb->g.a_hnp_support = 0;
2155 	musb->g.quirk_zlp_not_supp = 1;
2156 
2157 	/* Normal reset, as B-Device;
2158 	 * or else after HNP, as A-Device
2159 	 */
2160 	if (!musb->g.is_otg) {
2161 		/* USB device controllers that are not OTG compatible
2162 		 * may not have DEVCTL register in silicon.
2163 		 * In that case, do not rely on devctl for setting
2164 		 * peripheral mode.
2165 		 */
2166 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2167 		musb->g.is_a_peripheral = 0;
2168 	} else if (devctl & MUSB_DEVCTL_BDEVICE) {
2169 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2170 		musb->g.is_a_peripheral = 0;
2171 	} else {
2172 		musb->xceiv->otg->state = OTG_STATE_A_PERIPHERAL;
2173 		musb->g.is_a_peripheral = 1;
2174 	}
2175 
2176 	/* start with default limits on VBUS power draw */
2177 	(void) musb_gadget_vbus_draw(&musb->g, 8);
2178 }
2179