xref: /openbmc/linux/drivers/usb/musb/musb_gadget.c (revision 83b975b5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * MUSB OTG driver peripheral support
4  *
5  * Copyright 2005 Mentor Graphics Corporation
6  * Copyright (C) 2005-2006 by Texas Instruments
7  * Copyright (C) 2006-2007 Nokia Corporation
8  * Copyright (C) 2009 MontaVista Software, Inc. <source@mvista.com>
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/timer.h>
14 #include <linux/module.h>
15 #include <linux/smp.h>
16 #include <linux/spinlock.h>
17 #include <linux/delay.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/slab.h>
20 
21 #include "musb_core.h"
22 #include "musb_trace.h"
23 
24 
25 /* ----------------------------------------------------------------------- */
26 
27 #define is_buffer_mapped(req) (is_dma_capable() && \
28 					(req->map_state != UN_MAPPED))
29 
30 /* Maps the buffer to dma  */
31 
32 static inline void map_dma_buffer(struct musb_request *request,
33 			struct musb *musb, struct musb_ep *musb_ep)
34 {
35 	int compatible = true;
36 	struct dma_controller *dma = musb->dma_controller;
37 
38 	request->map_state = UN_MAPPED;
39 
40 	if (!is_dma_capable() || !musb_ep->dma)
41 		return;
42 
43 	/* Check if DMA engine can handle this request.
44 	 * DMA code must reject the USB request explicitly.
45 	 * Default behaviour is to map the request.
46 	 */
47 	if (dma->is_compatible)
48 		compatible = dma->is_compatible(musb_ep->dma,
49 				musb_ep->packet_sz, request->request.buf,
50 				request->request.length);
51 	if (!compatible)
52 		return;
53 
54 	if (request->request.dma == DMA_ADDR_INVALID) {
55 		dma_addr_t dma_addr;
56 		int ret;
57 
58 		dma_addr = dma_map_single(
59 				musb->controller,
60 				request->request.buf,
61 				request->request.length,
62 				request->tx
63 					? DMA_TO_DEVICE
64 					: DMA_FROM_DEVICE);
65 		ret = dma_mapping_error(musb->controller, dma_addr);
66 		if (ret)
67 			return;
68 
69 		request->request.dma = dma_addr;
70 		request->map_state = MUSB_MAPPED;
71 	} else {
72 		dma_sync_single_for_device(musb->controller,
73 			request->request.dma,
74 			request->request.length,
75 			request->tx
76 				? DMA_TO_DEVICE
77 				: DMA_FROM_DEVICE);
78 		request->map_state = PRE_MAPPED;
79 	}
80 }
81 
82 /* Unmap the buffer from dma and maps it back to cpu */
83 static inline void unmap_dma_buffer(struct musb_request *request,
84 				struct musb *musb)
85 {
86 	struct musb_ep *musb_ep = request->ep;
87 
88 	if (!is_buffer_mapped(request) || !musb_ep->dma)
89 		return;
90 
91 	if (request->request.dma == DMA_ADDR_INVALID) {
92 		dev_vdbg(musb->controller,
93 				"not unmapping a never mapped buffer\n");
94 		return;
95 	}
96 	if (request->map_state == MUSB_MAPPED) {
97 		dma_unmap_single(musb->controller,
98 			request->request.dma,
99 			request->request.length,
100 			request->tx
101 				? DMA_TO_DEVICE
102 				: DMA_FROM_DEVICE);
103 		request->request.dma = DMA_ADDR_INVALID;
104 	} else { /* PRE_MAPPED */
105 		dma_sync_single_for_cpu(musb->controller,
106 			request->request.dma,
107 			request->request.length,
108 			request->tx
109 				? DMA_TO_DEVICE
110 				: DMA_FROM_DEVICE);
111 	}
112 	request->map_state = UN_MAPPED;
113 }
114 
115 /*
116  * Immediately complete a request.
117  *
118  * @param request the request to complete
119  * @param status the status to complete the request with
120  * Context: controller locked, IRQs blocked.
121  */
122 void musb_g_giveback(
123 	struct musb_ep		*ep,
124 	struct usb_request	*request,
125 	int			status)
126 __releases(ep->musb->lock)
127 __acquires(ep->musb->lock)
128 {
129 	struct musb_request	*req;
130 	struct musb		*musb;
131 	int			busy = ep->busy;
132 
133 	req = to_musb_request(request);
134 
135 	list_del(&req->list);
136 	if (req->request.status == -EINPROGRESS)
137 		req->request.status = status;
138 	musb = req->musb;
139 
140 	ep->busy = 1;
141 	spin_unlock(&musb->lock);
142 
143 	if (!dma_mapping_error(&musb->g.dev, request->dma))
144 		unmap_dma_buffer(req, musb);
145 
146 	trace_musb_req_gb(req);
147 	usb_gadget_giveback_request(&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		*musb = ep->musb;
161 	struct musb_request	*req = NULL;
162 	void __iomem *epio = ep->musb->endpoints[ep->current_epnum].regs;
163 
164 	ep->busy = 1;
165 
166 	if (is_dma_capable() && ep->dma) {
167 		struct dma_controller	*c = ep->musb->dma_controller;
168 		int value;
169 
170 		if (ep->is_in) {
171 			/*
172 			 * The programming guide says that we must not clear
173 			 * the DMAMODE bit before DMAENAB, so we only
174 			 * clear it in the second write...
175 			 */
176 			musb_writew(epio, MUSB_TXCSR,
177 				    MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
178 			musb_writew(epio, MUSB_TXCSR,
179 					0 | MUSB_TXCSR_FLUSHFIFO);
180 		} else {
181 			musb_writew(epio, MUSB_RXCSR,
182 					0 | MUSB_RXCSR_FLUSHFIFO);
183 			musb_writew(epio, MUSB_RXCSR,
184 					0 | MUSB_RXCSR_FLUSHFIFO);
185 		}
186 
187 		value = c->channel_abort(ep->dma);
188 		musb_dbg(musb, "%s: abort DMA --> %d", ep->name, value);
189 		c->channel_release(ep->dma);
190 		ep->dma = NULL;
191 	}
192 
193 	while (!list_empty(&ep->req_list)) {
194 		req = list_first_entry(&ep->req_list, struct musb_request, list);
195 		musb_g_giveback(ep, &req->request, status);
196 	}
197 }
198 
199 /* ----------------------------------------------------------------------- */
200 
201 /* Data transfers - pure PIO, pure DMA, or mixed mode */
202 
203 /*
204  * This assumes the separate CPPI engine is responding to DMA requests
205  * from the usb core ... sequenced a bit differently from mentor dma.
206  */
207 
208 static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
209 {
210 	if (can_bulk_split(musb, ep->type))
211 		return ep->hw_ep->max_packet_sz_tx;
212 	else
213 		return ep->packet_sz;
214 }
215 
216 /*
217  * An endpoint is transmitting data. This can be called either from
218  * the IRQ routine or from ep.queue() to kickstart a request on an
219  * endpoint.
220  *
221  * Context: controller locked, IRQs blocked, endpoint selected
222  */
223 static void txstate(struct musb *musb, struct musb_request *req)
224 {
225 	u8			epnum = req->epnum;
226 	struct musb_ep		*musb_ep;
227 	void __iomem		*epio = musb->endpoints[epnum].regs;
228 	struct usb_request	*request;
229 	u16			fifo_count = 0, csr;
230 	int			use_dma = 0;
231 
232 	musb_ep = req->ep;
233 
234 	/* Check if EP is disabled */
235 	if (!musb_ep->desc) {
236 		musb_dbg(musb, "ep:%s disabled - ignore request",
237 						musb_ep->end_point.name);
238 		return;
239 	}
240 
241 	/* we shouldn't get here while DMA is active ... but we do ... */
242 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
243 		musb_dbg(musb, "dma pending...");
244 		return;
245 	}
246 
247 	/* read TXCSR before */
248 	csr = musb_readw(epio, MUSB_TXCSR);
249 
250 	request = &req->request;
251 	fifo_count = min(max_ep_writesize(musb, musb_ep),
252 			(int)(request->length - request->actual));
253 
254 	if (csr & MUSB_TXCSR_TXPKTRDY) {
255 		musb_dbg(musb, "%s old packet still ready , txcsr %03x",
256 				musb_ep->end_point.name, csr);
257 		return;
258 	}
259 
260 	if (csr & MUSB_TXCSR_P_SENDSTALL) {
261 		musb_dbg(musb, "%s stalling, txcsr %03x",
262 				musb_ep->end_point.name, csr);
263 		return;
264 	}
265 
266 	musb_dbg(musb, "hw_ep%d, maxpacket %d, fifo count %d, txcsr %03x",
267 			epnum, musb_ep->packet_sz, fifo_count,
268 			csr);
269 
270 #ifndef	CONFIG_MUSB_PIO_ONLY
271 	if (is_buffer_mapped(req)) {
272 		struct dma_controller	*c = musb->dma_controller;
273 		size_t request_size;
274 
275 		/* setup DMA, then program endpoint CSR */
276 		request_size = min_t(size_t, request->length - request->actual,
277 					musb_ep->dma->max_len);
278 
279 		use_dma = (request->dma != DMA_ADDR_INVALID && request_size);
280 
281 		/* MUSB_TXCSR_P_ISO is still set correctly */
282 
283 		if (musb_dma_inventra(musb) || musb_dma_ux500(musb)) {
284 			if (request_size < musb_ep->packet_sz)
285 				musb_ep->dma->desired_mode = 0;
286 			else
287 				musb_ep->dma->desired_mode = 1;
288 
289 			use_dma = use_dma && c->channel_program(
290 					musb_ep->dma, musb_ep->packet_sz,
291 					musb_ep->dma->desired_mode,
292 					request->dma + request->actual, request_size);
293 			if (use_dma) {
294 				if (musb_ep->dma->desired_mode == 0) {
295 					/*
296 					 * We must not clear the DMAMODE bit
297 					 * before the DMAENAB bit -- and the
298 					 * latter doesn't always get cleared
299 					 * before we get here...
300 					 */
301 					csr &= ~(MUSB_TXCSR_AUTOSET
302 						| MUSB_TXCSR_DMAENAB);
303 					musb_writew(epio, MUSB_TXCSR, csr
304 						| MUSB_TXCSR_P_WZC_BITS);
305 					csr &= ~MUSB_TXCSR_DMAMODE;
306 					csr |= (MUSB_TXCSR_DMAENAB |
307 							MUSB_TXCSR_MODE);
308 					/* against programming guide */
309 				} else {
310 					csr |= (MUSB_TXCSR_DMAENAB
311 							| MUSB_TXCSR_DMAMODE
312 							| MUSB_TXCSR_MODE);
313 					/*
314 					 * Enable Autoset according to table
315 					 * below
316 					 * bulk_split hb_mult	Autoset_Enable
317 					 *	0	0	Yes(Normal)
318 					 *	0	>0	No(High BW ISO)
319 					 *	1	0	Yes(HS bulk)
320 					 *	1	>0	Yes(FS bulk)
321 					 */
322 					if (!musb_ep->hb_mult ||
323 					    can_bulk_split(musb,
324 							   musb_ep->type))
325 						csr |= MUSB_TXCSR_AUTOSET;
326 				}
327 				csr &= ~MUSB_TXCSR_P_UNDERRUN;
328 
329 				musb_writew(epio, MUSB_TXCSR, csr);
330 			}
331 		}
332 
333 		if (is_cppi_enabled(musb)) {
334 			/* program endpoint CSR first, then setup DMA */
335 			csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
336 			csr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_DMAMODE |
337 				MUSB_TXCSR_MODE;
338 			musb_writew(epio, MUSB_TXCSR, (MUSB_TXCSR_P_WZC_BITS &
339 						~MUSB_TXCSR_P_UNDERRUN) | csr);
340 
341 			/* ensure writebuffer is empty */
342 			csr = musb_readw(epio, MUSB_TXCSR);
343 
344 			/*
345 			 * NOTE host side sets DMAENAB later than this; both are
346 			 * OK since the transfer dma glue (between CPPI and
347 			 * Mentor fifos) just tells CPPI it could start. Data
348 			 * only moves to the USB TX fifo when both fifos are
349 			 * ready.
350 			 */
351 			/*
352 			 * "mode" is irrelevant here; handle terminating ZLPs
353 			 * like PIO does, since the hardware RNDIS mode seems
354 			 * unreliable except for the
355 			 * last-packet-is-already-short case.
356 			 */
357 			use_dma = use_dma && c->channel_program(
358 					musb_ep->dma, musb_ep->packet_sz,
359 					0,
360 					request->dma + request->actual,
361 					request_size);
362 			if (!use_dma) {
363 				c->channel_release(musb_ep->dma);
364 				musb_ep->dma = NULL;
365 				csr &= ~MUSB_TXCSR_DMAENAB;
366 				musb_writew(epio, MUSB_TXCSR, csr);
367 				/* invariant: prequest->buf is non-null */
368 			}
369 		} else if (tusb_dma_omap(musb))
370 			use_dma = use_dma && c->channel_program(
371 					musb_ep->dma, musb_ep->packet_sz,
372 					request->zero,
373 					request->dma + request->actual,
374 					request_size);
375 	}
376 #endif
377 
378 	if (!use_dma) {
379 		/*
380 		 * Unmap the dma buffer back to cpu if dma channel
381 		 * programming fails
382 		 */
383 		unmap_dma_buffer(req, musb);
384 
385 		musb_write_fifo(musb_ep->hw_ep, fifo_count,
386 				(u8 *) (request->buf + request->actual));
387 		request->actual += fifo_count;
388 		csr |= MUSB_TXCSR_TXPKTRDY;
389 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
390 		musb_writew(epio, MUSB_TXCSR, csr);
391 	}
392 
393 	/* host may already have the data when this message shows... */
394 	musb_dbg(musb, "%s TX/IN %s len %d/%d, txcsr %04x, fifo %d/%d",
395 			musb_ep->end_point.name, use_dma ? "dma" : "pio",
396 			request->actual, request->length,
397 			musb_readw(epio, MUSB_TXCSR),
398 			fifo_count,
399 			musb_readw(epio, MUSB_TXMAXP));
400 }
401 
402 /*
403  * FIFO state update (e.g. data ready).
404  * Called from IRQ,  with controller locked.
405  */
406 void musb_g_tx(struct musb *musb, u8 epnum)
407 {
408 	u16			csr;
409 	struct musb_request	*req;
410 	struct usb_request	*request;
411 	u8 __iomem		*mbase = musb->mregs;
412 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_in;
413 	void __iomem		*epio = musb->endpoints[epnum].regs;
414 	struct dma_channel	*dma;
415 
416 	musb_ep_select(mbase, epnum);
417 	req = next_request(musb_ep);
418 	request = &req->request;
419 
420 	csr = musb_readw(epio, MUSB_TXCSR);
421 	musb_dbg(musb, "<== %s, txcsr %04x", musb_ep->end_point.name, csr);
422 
423 	dma = is_dma_capable() ? musb_ep->dma : NULL;
424 
425 	/*
426 	 * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX
427 	 * probably rates reporting as a host error.
428 	 */
429 	if (csr & MUSB_TXCSR_P_SENTSTALL) {
430 		csr |=	MUSB_TXCSR_P_WZC_BITS;
431 		csr &= ~MUSB_TXCSR_P_SENTSTALL;
432 		musb_writew(epio, MUSB_TXCSR, csr);
433 		return;
434 	}
435 
436 	if (csr & MUSB_TXCSR_P_UNDERRUN) {
437 		/* We NAKed, no big deal... little reason to care. */
438 		csr |=	 MUSB_TXCSR_P_WZC_BITS;
439 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
440 		musb_writew(epio, MUSB_TXCSR, csr);
441 		dev_vdbg(musb->controller, "underrun on ep%d, req %p\n",
442 				epnum, request);
443 	}
444 
445 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
446 		/*
447 		 * SHOULD NOT HAPPEN... has with CPPI though, after
448 		 * changing SENDSTALL (and other cases); harmless?
449 		 */
450 		musb_dbg(musb, "%s dma still busy?", musb_ep->end_point.name);
451 		return;
452 	}
453 
454 	if (req) {
455 
456 		trace_musb_req_tx(req);
457 
458 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
459 			csr |= MUSB_TXCSR_P_WZC_BITS;
460 			csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
461 				 MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET);
462 			musb_writew(epio, MUSB_TXCSR, csr);
463 			/* Ensure writebuffer is empty. */
464 			csr = musb_readw(epio, MUSB_TXCSR);
465 			request->actual += musb_ep->dma->actual_len;
466 			musb_dbg(musb, "TXCSR%d %04x, DMA off, len %zu, req %p",
467 				epnum, csr, musb_ep->dma->actual_len, request);
468 		}
469 
470 		/*
471 		 * First, maybe a terminating short packet. Some DMA
472 		 * engines might handle this by themselves.
473 		 */
474 		if ((request->zero && request->length)
475 			&& (request->length % musb_ep->packet_sz == 0)
476 			&& (request->actual == request->length)) {
477 
478 			/*
479 			 * On DMA completion, FIFO may not be
480 			 * available yet...
481 			 */
482 			if (csr & MUSB_TXCSR_TXPKTRDY)
483 				return;
484 
485 			musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
486 					| MUSB_TXCSR_TXPKTRDY);
487 			request->zero = 0;
488 		}
489 
490 		if (request->actual == request->length) {
491 			musb_g_giveback(musb_ep, request, 0);
492 			/*
493 			 * In the giveback function the MUSB lock is
494 			 * released and acquired after sometime. During
495 			 * this time period the INDEX register could get
496 			 * changed by the gadget_queue function especially
497 			 * on SMP systems. Reselect the INDEX to be sure
498 			 * we are reading/modifying the right registers
499 			 */
500 			musb_ep_select(mbase, epnum);
501 			req = musb_ep->desc ? next_request(musb_ep) : NULL;
502 			if (!req) {
503 				musb_dbg(musb, "%s idle now",
504 					musb_ep->end_point.name);
505 				return;
506 			}
507 		}
508 
509 		txstate(musb, req);
510 	}
511 }
512 
513 /* ------------------------------------------------------------ */
514 
515 /*
516  * Context: controller locked, IRQs blocked, endpoint selected
517  */
518 static void rxstate(struct musb *musb, struct musb_request *req)
519 {
520 	const u8		epnum = req->epnum;
521 	struct usb_request	*request = &req->request;
522 	struct musb_ep		*musb_ep;
523 	void __iomem		*epio = musb->endpoints[epnum].regs;
524 	unsigned		len = 0;
525 	u16			fifo_count;
526 	u16			csr = musb_readw(epio, MUSB_RXCSR);
527 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
528 	u8			use_mode_1;
529 
530 	if (hw_ep->is_shared_fifo)
531 		musb_ep = &hw_ep->ep_in;
532 	else
533 		musb_ep = &hw_ep->ep_out;
534 
535 	fifo_count = musb_ep->packet_sz;
536 
537 	/* Check if EP is disabled */
538 	if (!musb_ep->desc) {
539 		musb_dbg(musb, "ep:%s disabled - ignore request",
540 						musb_ep->end_point.name);
541 		return;
542 	}
543 
544 	/* We shouldn't get here while DMA is active, but we do... */
545 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
546 		musb_dbg(musb, "DMA pending...");
547 		return;
548 	}
549 
550 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
551 		musb_dbg(musb, "%s stalling, RXCSR %04x",
552 		    musb_ep->end_point.name, csr);
553 		return;
554 	}
555 
556 	if (is_cppi_enabled(musb) && is_buffer_mapped(req)) {
557 		struct dma_controller	*c = musb->dma_controller;
558 		struct dma_channel	*channel = musb_ep->dma;
559 
560 		/* NOTE:  CPPI won't actually stop advancing the DMA
561 		 * queue after short packet transfers, so this is almost
562 		 * always going to run as IRQ-per-packet DMA so that
563 		 * faults will be handled correctly.
564 		 */
565 		if (c->channel_program(channel,
566 				musb_ep->packet_sz,
567 				!request->short_not_ok,
568 				request->dma + request->actual,
569 				request->length - request->actual)) {
570 
571 			/* make sure that if an rxpkt arrived after the irq,
572 			 * the cppi engine will be ready to take it as soon
573 			 * as DMA is enabled
574 			 */
575 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
576 					| MUSB_RXCSR_DMAMODE);
577 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
578 			musb_writew(epio, MUSB_RXCSR, csr);
579 			return;
580 		}
581 	}
582 
583 	if (csr & MUSB_RXCSR_RXPKTRDY) {
584 		fifo_count = musb_readw(epio, MUSB_RXCOUNT);
585 
586 		/*
587 		 * Enable Mode 1 on RX transfers only when short_not_ok flag
588 		 * is set. Currently short_not_ok flag is set only from
589 		 * file_storage and f_mass_storage drivers
590 		 */
591 
592 		if (request->short_not_ok && fifo_count == musb_ep->packet_sz)
593 			use_mode_1 = 1;
594 		else
595 			use_mode_1 = 0;
596 
597 		if (request->actual < request->length) {
598 			if (!is_buffer_mapped(req))
599 				goto buffer_aint_mapped;
600 
601 			if (musb_dma_inventra(musb)) {
602 				struct dma_controller	*c;
603 				struct dma_channel	*channel;
604 				int			use_dma = 0;
605 				unsigned int transfer_size;
606 
607 				c = musb->dma_controller;
608 				channel = musb_ep->dma;
609 
610 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
611 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
612 	 * completion. We only get interrupts from DMA controller.
613 	 *
614 	 * We could operate in DMA mode 1 if we knew the size of the transfer
615 	 * in advance. For mass storage class, request->length = what the host
616 	 * sends, so that'd work.  But for pretty much everything else,
617 	 * request->length is routinely more than what the host sends. For
618 	 * most these gadgets, end of is signified either by a short packet,
619 	 * or filling the last byte of the buffer.  (Sending extra data in
620 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
621 	 * we don't get DMA completion interrupt for short packets.
622 	 *
623 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
624 	 * to get endpoint interrupt on every DMA req, but that didn't seem
625 	 * to work reliably.
626 	 *
627 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
628 	 * then becomes usable as a runtime "use mode 1" hint...
629 	 */
630 
631 				/* Experimental: Mode1 works with mass storage use cases */
632 				if (use_mode_1) {
633 					csr |= MUSB_RXCSR_AUTOCLEAR;
634 					musb_writew(epio, MUSB_RXCSR, csr);
635 					csr |= MUSB_RXCSR_DMAENAB;
636 					musb_writew(epio, MUSB_RXCSR, csr);
637 
638 					/*
639 					 * this special sequence (enabling and then
640 					 * disabling MUSB_RXCSR_DMAMODE) is required
641 					 * to get DMAReq to activate
642 					 */
643 					musb_writew(epio, MUSB_RXCSR,
644 						csr | MUSB_RXCSR_DMAMODE);
645 					musb_writew(epio, MUSB_RXCSR, csr);
646 
647 					transfer_size = min_t(unsigned int,
648 							request->length -
649 							request->actual,
650 							channel->max_len);
651 					musb_ep->dma->desired_mode = 1;
652 				} else {
653 					if (!musb_ep->hb_mult &&
654 						musb_ep->hw_ep->rx_double_buffered)
655 						csr |= MUSB_RXCSR_AUTOCLEAR;
656 					csr |= MUSB_RXCSR_DMAENAB;
657 					musb_writew(epio, MUSB_RXCSR, csr);
658 
659 					transfer_size = min(request->length - request->actual,
660 							(unsigned)fifo_count);
661 					musb_ep->dma->desired_mode = 0;
662 				}
663 
664 				use_dma = c->channel_program(
665 						channel,
666 						musb_ep->packet_sz,
667 						channel->desired_mode,
668 						request->dma
669 						+ request->actual,
670 						transfer_size);
671 
672 				if (use_dma)
673 					return;
674 			}
675 
676 			if ((musb_dma_ux500(musb)) &&
677 				(request->actual < request->length)) {
678 
679 				struct dma_controller *c;
680 				struct dma_channel *channel;
681 				unsigned int transfer_size = 0;
682 
683 				c = musb->dma_controller;
684 				channel = musb_ep->dma;
685 
686 				/* In case first packet is short */
687 				if (fifo_count < musb_ep->packet_sz)
688 					transfer_size = fifo_count;
689 				else if (request->short_not_ok)
690 					transfer_size =	min_t(unsigned int,
691 							request->length -
692 							request->actual,
693 							channel->max_len);
694 				else
695 					transfer_size = min_t(unsigned int,
696 							request->length -
697 							request->actual,
698 							(unsigned)fifo_count);
699 
700 				csr &= ~MUSB_RXCSR_DMAMODE;
701 				csr |= (MUSB_RXCSR_DMAENAB |
702 					MUSB_RXCSR_AUTOCLEAR);
703 
704 				musb_writew(epio, MUSB_RXCSR, csr);
705 
706 				if (transfer_size <= musb_ep->packet_sz) {
707 					musb_ep->dma->desired_mode = 0;
708 				} else {
709 					musb_ep->dma->desired_mode = 1;
710 					/* Mode must be set after DMAENAB */
711 					csr |= MUSB_RXCSR_DMAMODE;
712 					musb_writew(epio, MUSB_RXCSR, csr);
713 				}
714 
715 				if (c->channel_program(channel,
716 							musb_ep->packet_sz,
717 							channel->desired_mode,
718 							request->dma
719 							+ request->actual,
720 							transfer_size))
721 
722 					return;
723 			}
724 
725 			len = request->length - request->actual;
726 			musb_dbg(musb, "%s OUT/RX pio fifo %d/%d, maxpacket %d",
727 					musb_ep->end_point.name,
728 					fifo_count, len,
729 					musb_ep->packet_sz);
730 
731 			fifo_count = min_t(unsigned, len, fifo_count);
732 
733 			if (tusb_dma_omap(musb)) {
734 				struct dma_controller *c = musb->dma_controller;
735 				struct dma_channel *channel = musb_ep->dma;
736 				u32 dma_addr = request->dma + request->actual;
737 				int ret;
738 
739 				ret = c->channel_program(channel,
740 						musb_ep->packet_sz,
741 						channel->desired_mode,
742 						dma_addr,
743 						fifo_count);
744 				if (ret)
745 					return;
746 			}
747 
748 			/*
749 			 * Unmap the dma buffer back to cpu if dma channel
750 			 * programming fails. This buffer is mapped if the
751 			 * channel allocation is successful
752 			 */
753 			unmap_dma_buffer(req, musb);
754 
755 			/*
756 			 * Clear DMAENAB and AUTOCLEAR for the
757 			 * PIO mode transfer
758 			 */
759 			csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
760 			musb_writew(epio, MUSB_RXCSR, csr);
761 
762 buffer_aint_mapped:
763 			fifo_count = min_t(unsigned int,
764 					request->length - request->actual,
765 					(unsigned int)fifo_count);
766 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
767 					(request->buf + request->actual));
768 			request->actual += fifo_count;
769 
770 			/* REVISIT if we left anything in the fifo, flush
771 			 * it and report -EOVERFLOW
772 			 */
773 
774 			/* ack the read! */
775 			csr |= MUSB_RXCSR_P_WZC_BITS;
776 			csr &= ~MUSB_RXCSR_RXPKTRDY;
777 			musb_writew(epio, MUSB_RXCSR, csr);
778 		}
779 	}
780 
781 	/* reach the end or short packet detected */
782 	if (request->actual == request->length ||
783 	    fifo_count < musb_ep->packet_sz)
784 		musb_g_giveback(musb_ep, request, 0);
785 }
786 
787 /*
788  * Data ready for a request; called from IRQ
789  */
790 void musb_g_rx(struct musb *musb, u8 epnum)
791 {
792 	u16			csr;
793 	struct musb_request	*req;
794 	struct usb_request	*request;
795 	void __iomem		*mbase = musb->mregs;
796 	struct musb_ep		*musb_ep;
797 	void __iomem		*epio = musb->endpoints[epnum].regs;
798 	struct dma_channel	*dma;
799 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
800 
801 	if (hw_ep->is_shared_fifo)
802 		musb_ep = &hw_ep->ep_in;
803 	else
804 		musb_ep = &hw_ep->ep_out;
805 
806 	musb_ep_select(mbase, epnum);
807 
808 	req = next_request(musb_ep);
809 	if (!req)
810 		return;
811 
812 	trace_musb_req_rx(req);
813 	request = &req->request;
814 
815 	csr = musb_readw(epio, MUSB_RXCSR);
816 	dma = is_dma_capable() ? musb_ep->dma : NULL;
817 
818 	musb_dbg(musb, "<== %s, rxcsr %04x%s %p", musb_ep->end_point.name,
819 			csr, dma ? " (dma)" : "", request);
820 
821 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
822 		csr |= MUSB_RXCSR_P_WZC_BITS;
823 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
824 		musb_writew(epio, MUSB_RXCSR, csr);
825 		return;
826 	}
827 
828 	if (csr & MUSB_RXCSR_P_OVERRUN) {
829 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
830 		csr &= ~MUSB_RXCSR_P_OVERRUN;
831 		musb_writew(epio, MUSB_RXCSR, csr);
832 
833 		musb_dbg(musb, "%s iso overrun on %p", musb_ep->name, request);
834 		if (request->status == -EINPROGRESS)
835 			request->status = -EOVERFLOW;
836 	}
837 	if (csr & MUSB_RXCSR_INCOMPRX) {
838 		/* REVISIT not necessarily an error */
839 		musb_dbg(musb, "%s, incomprx", musb_ep->end_point.name);
840 	}
841 
842 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
843 		/* "should not happen"; likely RXPKTRDY pending for DMA */
844 		musb_dbg(musb, "%s busy, csr %04x",
845 			musb_ep->end_point.name, csr);
846 		return;
847 	}
848 
849 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
850 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
851 				| MUSB_RXCSR_DMAENAB
852 				| MUSB_RXCSR_DMAMODE);
853 		musb_writew(epio, MUSB_RXCSR,
854 			MUSB_RXCSR_P_WZC_BITS | csr);
855 
856 		request->actual += musb_ep->dma->actual_len;
857 
858 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
859 	defined(CONFIG_USB_UX500_DMA)
860 		/* Autoclear doesn't clear RxPktRdy for short packets */
861 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
862 				|| (dma->actual_len
863 					& (musb_ep->packet_sz - 1))) {
864 			/* ack the read! */
865 			csr &= ~MUSB_RXCSR_RXPKTRDY;
866 			musb_writew(epio, MUSB_RXCSR, csr);
867 		}
868 
869 		/* incomplete, and not short? wait for next IN packet */
870 		if ((request->actual < request->length)
871 				&& (musb_ep->dma->actual_len
872 					== musb_ep->packet_sz)) {
873 			/* In double buffer case, continue to unload fifo if
874  			 * there is Rx packet in FIFO.
875  			 **/
876 			csr = musb_readw(epio, MUSB_RXCSR);
877 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
878 				hw_ep->rx_double_buffered)
879 				goto exit;
880 			return;
881 		}
882 #endif
883 		musb_g_giveback(musb_ep, request, 0);
884 		/*
885 		 * In the giveback function the MUSB lock is
886 		 * released and acquired after sometime. During
887 		 * this time period the INDEX register could get
888 		 * changed by the gadget_queue function especially
889 		 * on SMP systems. Reselect the INDEX to be sure
890 		 * we are reading/modifying the right registers
891 		 */
892 		musb_ep_select(mbase, epnum);
893 
894 		req = next_request(musb_ep);
895 		if (!req)
896 			return;
897 	}
898 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
899 	defined(CONFIG_USB_UX500_DMA)
900 exit:
901 #endif
902 	/* Analyze request */
903 	rxstate(musb, req);
904 }
905 
906 /* ------------------------------------------------------------ */
907 
908 static int musb_gadget_enable(struct usb_ep *ep,
909 			const struct usb_endpoint_descriptor *desc)
910 {
911 	unsigned long		flags;
912 	struct musb_ep		*musb_ep;
913 	struct musb_hw_ep	*hw_ep;
914 	void __iomem		*regs;
915 	struct musb		*musb;
916 	void __iomem	*mbase;
917 	u8		epnum;
918 	u16		csr;
919 	unsigned	tmp;
920 	int		status = -EINVAL;
921 
922 	if (!ep || !desc)
923 		return -EINVAL;
924 
925 	musb_ep = to_musb_ep(ep);
926 	hw_ep = musb_ep->hw_ep;
927 	regs = hw_ep->regs;
928 	musb = musb_ep->musb;
929 	mbase = musb->mregs;
930 	epnum = musb_ep->current_epnum;
931 
932 	spin_lock_irqsave(&musb->lock, flags);
933 
934 	if (musb_ep->desc) {
935 		status = -EBUSY;
936 		goto fail;
937 	}
938 	musb_ep->type = usb_endpoint_type(desc);
939 
940 	/* check direction and (later) maxpacket size against endpoint */
941 	if (usb_endpoint_num(desc) != epnum)
942 		goto fail;
943 
944 	/* REVISIT this rules out high bandwidth periodic transfers */
945 	tmp = usb_endpoint_maxp_mult(desc) - 1;
946 	if (tmp) {
947 		int ok;
948 
949 		if (usb_endpoint_dir_in(desc))
950 			ok = musb->hb_iso_tx;
951 		else
952 			ok = musb->hb_iso_rx;
953 
954 		if (!ok) {
955 			musb_dbg(musb, "no support for high bandwidth ISO");
956 			goto fail;
957 		}
958 		musb_ep->hb_mult = tmp;
959 	} else {
960 		musb_ep->hb_mult = 0;
961 	}
962 
963 	musb_ep->packet_sz = usb_endpoint_maxp(desc);
964 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
965 
966 	/* enable the interrupts for the endpoint, set the endpoint
967 	 * packet size (or fail), set the mode, clear the fifo
968 	 */
969 	musb_ep_select(mbase, epnum);
970 	if (usb_endpoint_dir_in(desc)) {
971 
972 		if (hw_ep->is_shared_fifo)
973 			musb_ep->is_in = 1;
974 		if (!musb_ep->is_in)
975 			goto fail;
976 
977 		if (tmp > hw_ep->max_packet_sz_tx) {
978 			musb_dbg(musb, "packet size beyond hardware FIFO size");
979 			goto fail;
980 		}
981 
982 		musb->intrtxe |= (1 << epnum);
983 		musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
984 
985 		/* REVISIT if can_bulk_split(), use by updating "tmp";
986 		 * likewise high bandwidth periodic tx
987 		 */
988 		/* Set TXMAXP with the FIFO size of the endpoint
989 		 * to disable double buffering mode.
990 		 */
991 		if (can_bulk_split(musb, musb_ep->type))
992 			musb_ep->hb_mult = (hw_ep->max_packet_sz_tx /
993 						musb_ep->packet_sz) - 1;
994 		musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
995 				| (musb_ep->hb_mult << 11));
996 
997 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
998 		if (musb_readw(regs, MUSB_TXCSR)
999 				& MUSB_TXCSR_FIFONOTEMPTY)
1000 			csr |= MUSB_TXCSR_FLUSHFIFO;
1001 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1002 			csr |= MUSB_TXCSR_P_ISO;
1003 
1004 		/* set twice in case of double buffering */
1005 		musb_writew(regs, MUSB_TXCSR, csr);
1006 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1007 		musb_writew(regs, MUSB_TXCSR, csr);
1008 
1009 	} else {
1010 
1011 		if (hw_ep->is_shared_fifo)
1012 			musb_ep->is_in = 0;
1013 		if (musb_ep->is_in)
1014 			goto fail;
1015 
1016 		if (tmp > hw_ep->max_packet_sz_rx) {
1017 			musb_dbg(musb, "packet size beyond hardware FIFO size");
1018 			goto fail;
1019 		}
1020 
1021 		musb->intrrxe |= (1 << epnum);
1022 		musb_writew(mbase, MUSB_INTRRXE, musb->intrrxe);
1023 
1024 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1025 		 * likewise high bandwidth periodic rx
1026 		 */
1027 		/* Set RXMAXP with the FIFO size of the endpoint
1028 		 * to disable double buffering mode.
1029 		 */
1030 		musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1031 				| (musb_ep->hb_mult << 11));
1032 
1033 		/* force shared fifo to OUT-only mode */
1034 		if (hw_ep->is_shared_fifo) {
1035 			csr = musb_readw(regs, MUSB_TXCSR);
1036 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1037 			musb_writew(regs, MUSB_TXCSR, csr);
1038 		}
1039 
1040 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1041 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1042 			csr |= MUSB_RXCSR_P_ISO;
1043 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1044 			csr |= MUSB_RXCSR_DISNYET;
1045 
1046 		/* set twice in case of double buffering */
1047 		musb_writew(regs, MUSB_RXCSR, csr);
1048 		musb_writew(regs, MUSB_RXCSR, csr);
1049 	}
1050 
1051 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1052 	 * for some reason you run out of channels here.
1053 	 */
1054 	if (is_dma_capable() && musb->dma_controller) {
1055 		struct dma_controller	*c = musb->dma_controller;
1056 
1057 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1058 				(desc->bEndpointAddress & USB_DIR_IN));
1059 	} else
1060 		musb_ep->dma = NULL;
1061 
1062 	musb_ep->desc = desc;
1063 	musb_ep->busy = 0;
1064 	musb_ep->wedged = 0;
1065 	status = 0;
1066 
1067 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1068 			musb_driver_name, musb_ep->end_point.name,
1069 			musb_ep_xfertype_string(musb_ep->type),
1070 			musb_ep->is_in ? "IN" : "OUT",
1071 			musb_ep->dma ? "dma, " : "",
1072 			musb_ep->packet_sz);
1073 
1074 	schedule_delayed_work(&musb->irq_work, 0);
1075 
1076 fail:
1077 	spin_unlock_irqrestore(&musb->lock, flags);
1078 	return status;
1079 }
1080 
1081 /*
1082  * Disable an endpoint flushing all requests queued.
1083  */
1084 static int musb_gadget_disable(struct usb_ep *ep)
1085 {
1086 	unsigned long	flags;
1087 	struct musb	*musb;
1088 	u8		epnum;
1089 	struct musb_ep	*musb_ep;
1090 	void __iomem	*epio;
1091 
1092 	musb_ep = to_musb_ep(ep);
1093 	musb = musb_ep->musb;
1094 	epnum = musb_ep->current_epnum;
1095 	epio = musb->endpoints[epnum].regs;
1096 
1097 	spin_lock_irqsave(&musb->lock, flags);
1098 	musb_ep_select(musb->mregs, epnum);
1099 
1100 	/* zero the endpoint sizes */
1101 	if (musb_ep->is_in) {
1102 		musb->intrtxe &= ~(1 << epnum);
1103 		musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
1104 		musb_writew(epio, MUSB_TXMAXP, 0);
1105 	} else {
1106 		musb->intrrxe &= ~(1 << epnum);
1107 		musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
1108 		musb_writew(epio, MUSB_RXMAXP, 0);
1109 	}
1110 
1111 	/* abort all pending DMA and requests */
1112 	nuke(musb_ep, -ESHUTDOWN);
1113 
1114 	musb_ep->desc = NULL;
1115 	musb_ep->end_point.desc = NULL;
1116 
1117 	schedule_delayed_work(&musb->irq_work, 0);
1118 
1119 	spin_unlock_irqrestore(&(musb->lock), flags);
1120 
1121 	musb_dbg(musb, "%s", musb_ep->end_point.name);
1122 
1123 	return 0;
1124 }
1125 
1126 /*
1127  * Allocate a request for an endpoint.
1128  * Reused by ep0 code.
1129  */
1130 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1131 {
1132 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1133 	struct musb_request	*request = NULL;
1134 
1135 	request = kzalloc(sizeof *request, gfp_flags);
1136 	if (!request)
1137 		return NULL;
1138 
1139 	request->request.dma = DMA_ADDR_INVALID;
1140 	request->epnum = musb_ep->current_epnum;
1141 	request->ep = musb_ep;
1142 
1143 	trace_musb_req_alloc(request);
1144 	return &request->request;
1145 }
1146 
1147 /*
1148  * Free a request
1149  * Reused by ep0 code.
1150  */
1151 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1152 {
1153 	struct musb_request *request = to_musb_request(req);
1154 
1155 	trace_musb_req_free(request);
1156 	kfree(request);
1157 }
1158 
1159 static LIST_HEAD(buffers);
1160 
1161 struct free_record {
1162 	struct list_head	list;
1163 	struct device		*dev;
1164 	unsigned		bytes;
1165 	dma_addr_t		dma;
1166 };
1167 
1168 /*
1169  * Context: controller locked, IRQs blocked.
1170  */
1171 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1172 {
1173 	trace_musb_req_start(req);
1174 	musb_ep_select(musb->mregs, req->epnum);
1175 	if (req->tx)
1176 		txstate(musb, req);
1177 	else
1178 		rxstate(musb, req);
1179 }
1180 
1181 static int musb_ep_restart_resume_work(struct musb *musb, void *data)
1182 {
1183 	struct musb_request *req = data;
1184 
1185 	musb_ep_restart(musb, req);
1186 
1187 	return 0;
1188 }
1189 
1190 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1191 			gfp_t gfp_flags)
1192 {
1193 	struct musb_ep		*musb_ep;
1194 	struct musb_request	*request;
1195 	struct musb		*musb;
1196 	int			status;
1197 	unsigned long		lockflags;
1198 
1199 	if (!ep || !req)
1200 		return -EINVAL;
1201 	if (!req->buf)
1202 		return -ENODATA;
1203 
1204 	musb_ep = to_musb_ep(ep);
1205 	musb = musb_ep->musb;
1206 
1207 	request = to_musb_request(req);
1208 	request->musb = musb;
1209 
1210 	if (request->ep != musb_ep)
1211 		return -EINVAL;
1212 
1213 	status = pm_runtime_get(musb->controller);
1214 	if ((status != -EINPROGRESS) && status < 0) {
1215 		dev_err(musb->controller,
1216 			"pm runtime get failed in %s\n",
1217 			__func__);
1218 		pm_runtime_put_noidle(musb->controller);
1219 
1220 		return status;
1221 	}
1222 	status = 0;
1223 
1224 	trace_musb_req_enq(request);
1225 
1226 	/* request is mine now... */
1227 	request->request.actual = 0;
1228 	request->request.status = -EINPROGRESS;
1229 	request->epnum = musb_ep->current_epnum;
1230 	request->tx = musb_ep->is_in;
1231 
1232 	map_dma_buffer(request, musb, musb_ep);
1233 
1234 	spin_lock_irqsave(&musb->lock, lockflags);
1235 
1236 	/* don't queue if the ep is down */
1237 	if (!musb_ep->desc) {
1238 		musb_dbg(musb, "req %p queued to %s while ep %s",
1239 				req, ep->name, "disabled");
1240 		status = -ESHUTDOWN;
1241 		unmap_dma_buffer(request, musb);
1242 		goto unlock;
1243 	}
1244 
1245 	/* add request to the list */
1246 	list_add_tail(&request->list, &musb_ep->req_list);
1247 
1248 	/* it this is the head of the queue, start i/o ... */
1249 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next) {
1250 		status = musb_queue_resume_work(musb,
1251 						musb_ep_restart_resume_work,
1252 						request);
1253 		if (status < 0) {
1254 			dev_err(musb->controller, "%s resume work: %i\n",
1255 				__func__, status);
1256 			list_del(&request->list);
1257 		}
1258 	}
1259 
1260 unlock:
1261 	spin_unlock_irqrestore(&musb->lock, lockflags);
1262 	pm_runtime_mark_last_busy(musb->controller);
1263 	pm_runtime_put_autosuspend(musb->controller);
1264 
1265 	return status;
1266 }
1267 
1268 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1269 {
1270 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1271 	struct musb_request	*req = to_musb_request(request);
1272 	struct musb_request	*r;
1273 	unsigned long		flags;
1274 	int			status = 0;
1275 	struct musb		*musb = musb_ep->musb;
1276 
1277 	if (!ep || !request || req->ep != musb_ep)
1278 		return -EINVAL;
1279 
1280 	trace_musb_req_deq(req);
1281 
1282 	spin_lock_irqsave(&musb->lock, flags);
1283 
1284 	list_for_each_entry(r, &musb_ep->req_list, list) {
1285 		if (r == req)
1286 			break;
1287 	}
1288 	if (r != req) {
1289 		dev_err(musb->controller, "request %p not queued to %s\n",
1290 				request, ep->name);
1291 		status = -EINVAL;
1292 		goto done;
1293 	}
1294 
1295 	/* if the hardware doesn't have the request, easy ... */
1296 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1297 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1298 
1299 	/* ... else abort the dma transfer ... */
1300 	else if (is_dma_capable() && musb_ep->dma) {
1301 		struct dma_controller	*c = musb->dma_controller;
1302 
1303 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1304 		if (c->channel_abort)
1305 			status = c->channel_abort(musb_ep->dma);
1306 		else
1307 			status = -EBUSY;
1308 		if (status == 0)
1309 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1310 	} else {
1311 		/* NOTE: by sticking to easily tested hardware/driver states,
1312 		 * we leave counting of in-flight packets imprecise.
1313 		 */
1314 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1315 	}
1316 
1317 done:
1318 	spin_unlock_irqrestore(&musb->lock, flags);
1319 	return status;
1320 }
1321 
1322 /*
1323  * Set or clear the halt bit of an endpoint. A halted endpoint won't tx/rx any
1324  * data but will queue requests.
1325  *
1326  * exported to ep0 code
1327  */
1328 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1329 {
1330 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1331 	u8			epnum = musb_ep->current_epnum;
1332 	struct musb		*musb = musb_ep->musb;
1333 	void __iomem		*epio = musb->endpoints[epnum].regs;
1334 	void __iomem		*mbase;
1335 	unsigned long		flags;
1336 	u16			csr;
1337 	struct musb_request	*request;
1338 	int			status = 0;
1339 
1340 	if (!ep)
1341 		return -EINVAL;
1342 	mbase = musb->mregs;
1343 
1344 	spin_lock_irqsave(&musb->lock, flags);
1345 
1346 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1347 		status = -EINVAL;
1348 		goto done;
1349 	}
1350 
1351 	musb_ep_select(mbase, epnum);
1352 
1353 	request = next_request(musb_ep);
1354 	if (value) {
1355 		if (request) {
1356 			musb_dbg(musb, "request in progress, cannot halt %s",
1357 			    ep->name);
1358 			status = -EAGAIN;
1359 			goto done;
1360 		}
1361 		/* Cannot portably stall with non-empty FIFO */
1362 		if (musb_ep->is_in) {
1363 			csr = musb_readw(epio, MUSB_TXCSR);
1364 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1365 				musb_dbg(musb, "FIFO busy, cannot halt %s",
1366 						ep->name);
1367 				status = -EAGAIN;
1368 				goto done;
1369 			}
1370 		}
1371 	} else
1372 		musb_ep->wedged = 0;
1373 
1374 	/* set/clear the stall and toggle bits */
1375 	musb_dbg(musb, "%s: %s stall", ep->name, value ? "set" : "clear");
1376 	if (musb_ep->is_in) {
1377 		csr = musb_readw(epio, MUSB_TXCSR);
1378 		csr |= MUSB_TXCSR_P_WZC_BITS
1379 			| MUSB_TXCSR_CLRDATATOG;
1380 		if (value)
1381 			csr |= MUSB_TXCSR_P_SENDSTALL;
1382 		else
1383 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1384 				| MUSB_TXCSR_P_SENTSTALL);
1385 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1386 		musb_writew(epio, MUSB_TXCSR, csr);
1387 	} else {
1388 		csr = musb_readw(epio, MUSB_RXCSR);
1389 		csr |= MUSB_RXCSR_P_WZC_BITS
1390 			| MUSB_RXCSR_FLUSHFIFO
1391 			| MUSB_RXCSR_CLRDATATOG;
1392 		if (value)
1393 			csr |= MUSB_RXCSR_P_SENDSTALL;
1394 		else
1395 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1396 				| MUSB_RXCSR_P_SENTSTALL);
1397 		musb_writew(epio, MUSB_RXCSR, csr);
1398 	}
1399 
1400 	/* maybe start the first request in the queue */
1401 	if (!musb_ep->busy && !value && request) {
1402 		musb_dbg(musb, "restarting the request");
1403 		musb_ep_restart(musb, request);
1404 	}
1405 
1406 done:
1407 	spin_unlock_irqrestore(&musb->lock, flags);
1408 	return status;
1409 }
1410 
1411 /*
1412  * Sets the halt feature with the clear requests ignored
1413  */
1414 static int musb_gadget_set_wedge(struct usb_ep *ep)
1415 {
1416 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1417 
1418 	if (!ep)
1419 		return -EINVAL;
1420 
1421 	musb_ep->wedged = 1;
1422 
1423 	return usb_ep_set_halt(ep);
1424 }
1425 
1426 static int musb_gadget_fifo_status(struct usb_ep *ep)
1427 {
1428 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1429 	void __iomem		*epio = musb_ep->hw_ep->regs;
1430 	int			retval = -EINVAL;
1431 
1432 	if (musb_ep->desc && !musb_ep->is_in) {
1433 		struct musb		*musb = musb_ep->musb;
1434 		int			epnum = musb_ep->current_epnum;
1435 		void __iomem		*mbase = musb->mregs;
1436 		unsigned long		flags;
1437 
1438 		spin_lock_irqsave(&musb->lock, flags);
1439 
1440 		musb_ep_select(mbase, epnum);
1441 		/* FIXME return zero unless RXPKTRDY is set */
1442 		retval = musb_readw(epio, MUSB_RXCOUNT);
1443 
1444 		spin_unlock_irqrestore(&musb->lock, flags);
1445 	}
1446 	return retval;
1447 }
1448 
1449 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1450 {
1451 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1452 	struct musb	*musb = musb_ep->musb;
1453 	u8		epnum = musb_ep->current_epnum;
1454 	void __iomem	*epio = musb->endpoints[epnum].regs;
1455 	void __iomem	*mbase;
1456 	unsigned long	flags;
1457 	u16		csr;
1458 
1459 	mbase = musb->mregs;
1460 
1461 	spin_lock_irqsave(&musb->lock, flags);
1462 	musb_ep_select(mbase, (u8) epnum);
1463 
1464 	/* disable interrupts */
1465 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe & ~(1 << epnum));
1466 
1467 	if (musb_ep->is_in) {
1468 		csr = musb_readw(epio, MUSB_TXCSR);
1469 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1470 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1471 			/*
1472 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1473 			 * to interrupt current FIFO loading, but not flushing
1474 			 * the already loaded ones.
1475 			 */
1476 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1477 			musb_writew(epio, MUSB_TXCSR, csr);
1478 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1479 			musb_writew(epio, MUSB_TXCSR, csr);
1480 		}
1481 	} else {
1482 		csr = musb_readw(epio, MUSB_RXCSR);
1483 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1484 		musb_writew(epio, MUSB_RXCSR, csr);
1485 		musb_writew(epio, MUSB_RXCSR, csr);
1486 	}
1487 
1488 	/* re-enable interrupt */
1489 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
1490 	spin_unlock_irqrestore(&musb->lock, flags);
1491 }
1492 
1493 static const struct usb_ep_ops musb_ep_ops = {
1494 	.enable		= musb_gadget_enable,
1495 	.disable	= musb_gadget_disable,
1496 	.alloc_request	= musb_alloc_request,
1497 	.free_request	= musb_free_request,
1498 	.queue		= musb_gadget_queue,
1499 	.dequeue	= musb_gadget_dequeue,
1500 	.set_halt	= musb_gadget_set_halt,
1501 	.set_wedge	= musb_gadget_set_wedge,
1502 	.fifo_status	= musb_gadget_fifo_status,
1503 	.fifo_flush	= musb_gadget_fifo_flush
1504 };
1505 
1506 /* ----------------------------------------------------------------------- */
1507 
1508 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1509 {
1510 	struct musb	*musb = gadget_to_musb(gadget);
1511 
1512 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1513 }
1514 
1515 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1516 {
1517 	struct musb	*musb = gadget_to_musb(gadget);
1518 	void __iomem	*mregs = musb->mregs;
1519 	unsigned long	flags;
1520 	int		status = -EINVAL;
1521 	u8		power, devctl;
1522 	int		retries;
1523 
1524 	spin_lock_irqsave(&musb->lock, flags);
1525 
1526 	switch (musb->xceiv->otg->state) {
1527 	case OTG_STATE_B_PERIPHERAL:
1528 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1529 		 * that's part of the standard usb 1.1 state machine, and
1530 		 * doesn't affect OTG transitions.
1531 		 */
1532 		if (musb->may_wakeup && musb->is_suspended)
1533 			break;
1534 		goto done;
1535 	case OTG_STATE_B_IDLE:
1536 		/* Start SRP ... OTG not required. */
1537 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1538 		musb_dbg(musb, "Sending SRP: devctl: %02x", devctl);
1539 		devctl |= MUSB_DEVCTL_SESSION;
1540 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1541 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1542 		retries = 100;
1543 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1544 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1545 			if (retries-- < 1)
1546 				break;
1547 		}
1548 		retries = 10000;
1549 		while (devctl & MUSB_DEVCTL_SESSION) {
1550 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1551 			if (retries-- < 1)
1552 				break;
1553 		}
1554 
1555 		spin_unlock_irqrestore(&musb->lock, flags);
1556 		otg_start_srp(musb->xceiv->otg);
1557 		spin_lock_irqsave(&musb->lock, flags);
1558 
1559 		/* Block idling for at least 1s */
1560 		musb_platform_try_idle(musb,
1561 			jiffies + msecs_to_jiffies(1 * HZ));
1562 
1563 		status = 0;
1564 		goto done;
1565 	default:
1566 		musb_dbg(musb, "Unhandled wake: %s",
1567 			usb_otg_state_string(musb->xceiv->otg->state));
1568 		goto done;
1569 	}
1570 
1571 	status = 0;
1572 
1573 	power = musb_readb(mregs, MUSB_POWER);
1574 	power |= MUSB_POWER_RESUME;
1575 	musb_writeb(mregs, MUSB_POWER, power);
1576 	musb_dbg(musb, "issue wakeup");
1577 
1578 	/* FIXME do this next chunk in a timer callback, no udelay */
1579 	mdelay(2);
1580 
1581 	power = musb_readb(mregs, MUSB_POWER);
1582 	power &= ~MUSB_POWER_RESUME;
1583 	musb_writeb(mregs, MUSB_POWER, power);
1584 done:
1585 	spin_unlock_irqrestore(&musb->lock, flags);
1586 	return status;
1587 }
1588 
1589 static int
1590 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1591 {
1592 	gadget->is_selfpowered = !!is_selfpowered;
1593 	return 0;
1594 }
1595 
1596 static void musb_pullup(struct musb *musb, int is_on)
1597 {
1598 	u8 power;
1599 
1600 	power = musb_readb(musb->mregs, MUSB_POWER);
1601 	if (is_on)
1602 		power |= MUSB_POWER_SOFTCONN;
1603 	else
1604 		power &= ~MUSB_POWER_SOFTCONN;
1605 
1606 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1607 
1608 	musb_dbg(musb, "gadget D+ pullup %s",
1609 		is_on ? "on" : "off");
1610 	musb_writeb(musb->mregs, MUSB_POWER, power);
1611 }
1612 
1613 #if 0
1614 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1615 {
1616 	musb_dbg(musb, "<= %s =>\n", __func__);
1617 
1618 	/*
1619 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1620 	 * though that can clear it), just musb_pullup().
1621 	 */
1622 
1623 	return -EINVAL;
1624 }
1625 #endif
1626 
1627 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1628 {
1629 	struct musb	*musb = gadget_to_musb(gadget);
1630 
1631 	if (!musb->xceiv->set_power)
1632 		return -EOPNOTSUPP;
1633 	return usb_phy_set_power(musb->xceiv, mA);
1634 }
1635 
1636 static void musb_gadget_work(struct work_struct *work)
1637 {
1638 	struct musb *musb;
1639 	unsigned long flags;
1640 
1641 	musb = container_of(work, struct musb, gadget_work.work);
1642 	pm_runtime_get_sync(musb->controller);
1643 	spin_lock_irqsave(&musb->lock, flags);
1644 	musb_pullup(musb, musb->softconnect);
1645 	spin_unlock_irqrestore(&musb->lock, flags);
1646 	pm_runtime_mark_last_busy(musb->controller);
1647 	pm_runtime_put_autosuspend(musb->controller);
1648 }
1649 
1650 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1651 {
1652 	struct musb	*musb = gadget_to_musb(gadget);
1653 	unsigned long	flags;
1654 
1655 	is_on = !!is_on;
1656 
1657 	/* NOTE: this assumes we are sensing vbus; we'd rather
1658 	 * not pullup unless the B-session is active.
1659 	 */
1660 	spin_lock_irqsave(&musb->lock, flags);
1661 	if (is_on != musb->softconnect) {
1662 		musb->softconnect = is_on;
1663 		schedule_delayed_work(&musb->gadget_work, 0);
1664 	}
1665 	spin_unlock_irqrestore(&musb->lock, flags);
1666 
1667 	return 0;
1668 }
1669 
1670 static int musb_gadget_start(struct usb_gadget *g,
1671 		struct usb_gadget_driver *driver);
1672 static int musb_gadget_stop(struct usb_gadget *g);
1673 
1674 static const struct usb_gadget_ops musb_gadget_operations = {
1675 	.get_frame		= musb_gadget_get_frame,
1676 	.wakeup			= musb_gadget_wakeup,
1677 	.set_selfpowered	= musb_gadget_set_self_powered,
1678 	/* .vbus_session		= musb_gadget_vbus_session, */
1679 	.vbus_draw		= musb_gadget_vbus_draw,
1680 	.pullup			= musb_gadget_pullup,
1681 	.udc_start		= musb_gadget_start,
1682 	.udc_stop		= musb_gadget_stop,
1683 };
1684 
1685 /* ----------------------------------------------------------------------- */
1686 
1687 /* Registration */
1688 
1689 /* Only this registration code "knows" the rule (from USB standards)
1690  * about there being only one external upstream port.  It assumes
1691  * all peripheral ports are external...
1692  */
1693 
1694 static void
1695 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1696 {
1697 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1698 
1699 	memset(ep, 0, sizeof *ep);
1700 
1701 	ep->current_epnum = epnum;
1702 	ep->musb = musb;
1703 	ep->hw_ep = hw_ep;
1704 	ep->is_in = is_in;
1705 
1706 	INIT_LIST_HEAD(&ep->req_list);
1707 
1708 	sprintf(ep->name, "ep%d%s", epnum,
1709 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1710 				is_in ? "in" : "out"));
1711 	ep->end_point.name = ep->name;
1712 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1713 	if (!epnum) {
1714 		usb_ep_set_maxpacket_limit(&ep->end_point, 64);
1715 		ep->end_point.caps.type_control = true;
1716 		ep->end_point.ops = &musb_g_ep0_ops;
1717 		musb->g.ep0 = &ep->end_point;
1718 	} else {
1719 		if (is_in)
1720 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_tx);
1721 		else
1722 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_rx);
1723 		ep->end_point.caps.type_iso = true;
1724 		ep->end_point.caps.type_bulk = true;
1725 		ep->end_point.caps.type_int = true;
1726 		ep->end_point.ops = &musb_ep_ops;
1727 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1728 	}
1729 
1730 	if (!epnum || hw_ep->is_shared_fifo) {
1731 		ep->end_point.caps.dir_in = true;
1732 		ep->end_point.caps.dir_out = true;
1733 	} else if (is_in)
1734 		ep->end_point.caps.dir_in = true;
1735 	else
1736 		ep->end_point.caps.dir_out = true;
1737 }
1738 
1739 /*
1740  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1741  * to the rest of the driver state.
1742  */
1743 static inline void musb_g_init_endpoints(struct musb *musb)
1744 {
1745 	u8			epnum;
1746 	struct musb_hw_ep	*hw_ep;
1747 	unsigned		count = 0;
1748 
1749 	/* initialize endpoint list just once */
1750 	INIT_LIST_HEAD(&(musb->g.ep_list));
1751 
1752 	for (epnum = 0, hw_ep = musb->endpoints;
1753 			epnum < musb->nr_endpoints;
1754 			epnum++, hw_ep++) {
1755 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1756 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1757 			count++;
1758 		} else {
1759 			if (hw_ep->max_packet_sz_tx) {
1760 				init_peripheral_ep(musb, &hw_ep->ep_in,
1761 							epnum, 1);
1762 				count++;
1763 			}
1764 			if (hw_ep->max_packet_sz_rx) {
1765 				init_peripheral_ep(musb, &hw_ep->ep_out,
1766 							epnum, 0);
1767 				count++;
1768 			}
1769 		}
1770 	}
1771 }
1772 
1773 /* called once during driver setup to initialize and link into
1774  * the driver model; memory is zeroed.
1775  */
1776 int musb_gadget_setup(struct musb *musb)
1777 {
1778 	int status;
1779 
1780 	/* REVISIT minor race:  if (erroneously) setting up two
1781 	 * musb peripherals at the same time, only the bus lock
1782 	 * is probably held.
1783 	 */
1784 
1785 	musb->g.ops = &musb_gadget_operations;
1786 	musb->g.max_speed = USB_SPEED_HIGH;
1787 	musb->g.speed = USB_SPEED_UNKNOWN;
1788 
1789 	MUSB_DEV_MODE(musb);
1790 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1791 
1792 	/* this "gadget" abstracts/virtualizes the controller */
1793 	musb->g.name = musb_driver_name;
1794 	/* don't support otg protocols */
1795 	musb->g.is_otg = 0;
1796 	INIT_DELAYED_WORK(&musb->gadget_work, musb_gadget_work);
1797 	musb_g_init_endpoints(musb);
1798 
1799 	musb->is_active = 0;
1800 	musb_platform_try_idle(musb, 0);
1801 
1802 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1803 	if (status)
1804 		goto err;
1805 
1806 	return 0;
1807 err:
1808 	musb->g.dev.parent = NULL;
1809 	device_unregister(&musb->g.dev);
1810 	return status;
1811 }
1812 
1813 void musb_gadget_cleanup(struct musb *musb)
1814 {
1815 	if (musb->port_mode == MUSB_HOST)
1816 		return;
1817 
1818 	cancel_delayed_work_sync(&musb->gadget_work);
1819 	usb_del_gadget_udc(&musb->g);
1820 }
1821 
1822 /*
1823  * Register the gadget driver. Used by gadget drivers when
1824  * registering themselves with the controller.
1825  *
1826  * -EINVAL something went wrong (not driver)
1827  * -EBUSY another gadget is already using the controller
1828  * -ENOMEM no memory to perform the operation
1829  *
1830  * @param driver the gadget driver
1831  * @return <0 if error, 0 if everything is fine
1832  */
1833 static int musb_gadget_start(struct usb_gadget *g,
1834 		struct usb_gadget_driver *driver)
1835 {
1836 	struct musb		*musb = gadget_to_musb(g);
1837 	struct usb_otg		*otg = musb->xceiv->otg;
1838 	unsigned long		flags;
1839 	int			retval = 0;
1840 
1841 	if (driver->max_speed < USB_SPEED_HIGH) {
1842 		retval = -EINVAL;
1843 		goto err;
1844 	}
1845 
1846 	pm_runtime_get_sync(musb->controller);
1847 
1848 	musb->softconnect = 0;
1849 	musb->gadget_driver = driver;
1850 
1851 	spin_lock_irqsave(&musb->lock, flags);
1852 	musb->is_active = 1;
1853 
1854 	otg_set_peripheral(otg, &musb->g);
1855 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1856 	spin_unlock_irqrestore(&musb->lock, flags);
1857 
1858 	musb_start(musb);
1859 
1860 	/* REVISIT:  funcall to other code, which also
1861 	 * handles power budgeting ... this way also
1862 	 * ensures HdrcStart is indirectly called.
1863 	 */
1864 	if (musb->xceiv->last_event == USB_EVENT_ID)
1865 		musb_platform_set_vbus(musb, 1);
1866 
1867 	pm_runtime_mark_last_busy(musb->controller);
1868 	pm_runtime_put_autosuspend(musb->controller);
1869 
1870 	return 0;
1871 
1872 err:
1873 	return retval;
1874 }
1875 
1876 /*
1877  * Unregister the gadget driver. Used by gadget drivers when
1878  * unregistering themselves from the controller.
1879  *
1880  * @param driver the gadget driver to unregister
1881  */
1882 static int musb_gadget_stop(struct usb_gadget *g)
1883 {
1884 	struct musb	*musb = gadget_to_musb(g);
1885 	unsigned long	flags;
1886 
1887 	pm_runtime_get_sync(musb->controller);
1888 
1889 	/*
1890 	 * REVISIT always use otg_set_peripheral() here too;
1891 	 * this needs to shut down the OTG engine.
1892 	 */
1893 
1894 	spin_lock_irqsave(&musb->lock, flags);
1895 
1896 	musb_hnp_stop(musb);
1897 
1898 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1899 
1900 	musb->xceiv->otg->state = OTG_STATE_UNDEFINED;
1901 	musb_stop(musb);
1902 	otg_set_peripheral(musb->xceiv->otg, NULL);
1903 
1904 	musb->is_active = 0;
1905 	musb->gadget_driver = NULL;
1906 	musb_platform_try_idle(musb, 0);
1907 	spin_unlock_irqrestore(&musb->lock, flags);
1908 
1909 	/*
1910 	 * FIXME we need to be able to register another
1911 	 * gadget driver here and have everything work;
1912 	 * that currently misbehaves.
1913 	 */
1914 
1915 	/* Force check of devctl register for PM runtime */
1916 	pm_runtime_mark_last_busy(musb->controller);
1917 	pm_runtime_put_autosuspend(musb->controller);
1918 
1919 	return 0;
1920 }
1921 
1922 /* ----------------------------------------------------------------------- */
1923 
1924 /* lifecycle operations called through plat_uds.c */
1925 
1926 void musb_g_resume(struct musb *musb)
1927 {
1928 	musb->is_suspended = 0;
1929 	switch (musb->xceiv->otg->state) {
1930 	case OTG_STATE_B_IDLE:
1931 		break;
1932 	case OTG_STATE_B_WAIT_ACON:
1933 	case OTG_STATE_B_PERIPHERAL:
1934 		musb->is_active = 1;
1935 		if (musb->gadget_driver && musb->gadget_driver->resume) {
1936 			spin_unlock(&musb->lock);
1937 			musb->gadget_driver->resume(&musb->g);
1938 			spin_lock(&musb->lock);
1939 		}
1940 		break;
1941 	default:
1942 		WARNING("unhandled RESUME transition (%s)\n",
1943 				usb_otg_state_string(musb->xceiv->otg->state));
1944 	}
1945 }
1946 
1947 /* called when SOF packets stop for 3+ msec */
1948 void musb_g_suspend(struct musb *musb)
1949 {
1950 	u8	devctl;
1951 
1952 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
1953 	musb_dbg(musb, "musb_g_suspend: devctl %02x", devctl);
1954 
1955 	switch (musb->xceiv->otg->state) {
1956 	case OTG_STATE_B_IDLE:
1957 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
1958 			musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
1959 		break;
1960 	case OTG_STATE_B_PERIPHERAL:
1961 		musb->is_suspended = 1;
1962 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
1963 			spin_unlock(&musb->lock);
1964 			musb->gadget_driver->suspend(&musb->g);
1965 			spin_lock(&musb->lock);
1966 		}
1967 		break;
1968 	default:
1969 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
1970 		 * A_PERIPHERAL may need care too
1971 		 */
1972 		WARNING("unhandled SUSPEND transition (%s)",
1973 				usb_otg_state_string(musb->xceiv->otg->state));
1974 	}
1975 }
1976 
1977 /* Called during SRP */
1978 void musb_g_wakeup(struct musb *musb)
1979 {
1980 	musb_gadget_wakeup(&musb->g);
1981 }
1982 
1983 /* called when VBUS drops below session threshold, and in other cases */
1984 void musb_g_disconnect(struct musb *musb)
1985 {
1986 	void __iomem	*mregs = musb->mregs;
1987 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
1988 
1989 	musb_dbg(musb, "musb_g_disconnect: devctl %02x", devctl);
1990 
1991 	/* clear HR */
1992 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
1993 
1994 	/* don't draw vbus until new b-default session */
1995 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1996 
1997 	musb->g.speed = USB_SPEED_UNKNOWN;
1998 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
1999 		spin_unlock(&musb->lock);
2000 		musb->gadget_driver->disconnect(&musb->g);
2001 		spin_lock(&musb->lock);
2002 	}
2003 
2004 	switch (musb->xceiv->otg->state) {
2005 	default:
2006 		musb_dbg(musb, "Unhandled disconnect %s, setting a_idle",
2007 			usb_otg_state_string(musb->xceiv->otg->state));
2008 		musb->xceiv->otg->state = OTG_STATE_A_IDLE;
2009 		MUSB_HST_MODE(musb);
2010 		break;
2011 	case OTG_STATE_A_PERIPHERAL:
2012 		musb->xceiv->otg->state = OTG_STATE_A_WAIT_BCON;
2013 		MUSB_HST_MODE(musb);
2014 		break;
2015 	case OTG_STATE_B_WAIT_ACON:
2016 	case OTG_STATE_B_HOST:
2017 	case OTG_STATE_B_PERIPHERAL:
2018 	case OTG_STATE_B_IDLE:
2019 		musb->xceiv->otg->state = OTG_STATE_B_IDLE;
2020 		break;
2021 	case OTG_STATE_B_SRP_INIT:
2022 		break;
2023 	}
2024 
2025 	musb->is_active = 0;
2026 }
2027 
2028 void musb_g_reset(struct musb *musb)
2029 __releases(musb->lock)
2030 __acquires(musb->lock)
2031 {
2032 	void __iomem	*mbase = musb->mregs;
2033 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2034 	u8		power;
2035 
2036 	musb_dbg(musb, "<== %s driver '%s'",
2037 			(devctl & MUSB_DEVCTL_BDEVICE)
2038 				? "B-Device" : "A-Device",
2039 			musb->gadget_driver
2040 				? musb->gadget_driver->driver.name
2041 				: NULL
2042 			);
2043 
2044 	/* report reset, if we didn't already (flushing EP state) */
2045 	if (musb->gadget_driver && musb->g.speed != USB_SPEED_UNKNOWN) {
2046 		spin_unlock(&musb->lock);
2047 		usb_gadget_udc_reset(&musb->g, musb->gadget_driver);
2048 		spin_lock(&musb->lock);
2049 	}
2050 
2051 	/* clear HR */
2052 	else if (devctl & MUSB_DEVCTL_HR)
2053 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2054 
2055 
2056 	/* what speed did we negotiate? */
2057 	power = musb_readb(mbase, MUSB_POWER);
2058 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2059 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2060 
2061 	/* start in USB_STATE_DEFAULT */
2062 	musb->is_active = 1;
2063 	musb->is_suspended = 0;
2064 	MUSB_DEV_MODE(musb);
2065 	musb->address = 0;
2066 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2067 
2068 	musb->may_wakeup = 0;
2069 	musb->g.b_hnp_enable = 0;
2070 	musb->g.a_alt_hnp_support = 0;
2071 	musb->g.a_hnp_support = 0;
2072 	musb->g.quirk_zlp_not_supp = 1;
2073 
2074 	/* Normal reset, as B-Device;
2075 	 * or else after HNP, as A-Device
2076 	 */
2077 	if (!musb->g.is_otg) {
2078 		/* USB device controllers that are not OTG compatible
2079 		 * may not have DEVCTL register in silicon.
2080 		 * In that case, do not rely on devctl for setting
2081 		 * peripheral mode.
2082 		 */
2083 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2084 		musb->g.is_a_peripheral = 0;
2085 	} else if (devctl & MUSB_DEVCTL_BDEVICE) {
2086 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2087 		musb->g.is_a_peripheral = 0;
2088 	} else {
2089 		musb->xceiv->otg->state = OTG_STATE_A_PERIPHERAL;
2090 		musb->g.is_a_peripheral = 1;
2091 	}
2092 
2093 	/* start with default limits on VBUS power draw */
2094 	(void) musb_gadget_vbus_draw(&musb->g, 8);
2095 }
2096