xref: /openbmc/linux/drivers/usb/musb/musb_gadget.c (revision 63705da3)
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 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
764 					(request->buf + request->actual));
765 			request->actual += fifo_count;
766 
767 			/* REVISIT if we left anything in the fifo, flush
768 			 * it and report -EOVERFLOW
769 			 */
770 
771 			/* ack the read! */
772 			csr |= MUSB_RXCSR_P_WZC_BITS;
773 			csr &= ~MUSB_RXCSR_RXPKTRDY;
774 			musb_writew(epio, MUSB_RXCSR, csr);
775 		}
776 	}
777 
778 	/* reach the end or short packet detected */
779 	if (request->actual == request->length ||
780 	    fifo_count < musb_ep->packet_sz)
781 		musb_g_giveback(musb_ep, request, 0);
782 }
783 
784 /*
785  * Data ready for a request; called from IRQ
786  */
787 void musb_g_rx(struct musb *musb, u8 epnum)
788 {
789 	u16			csr;
790 	struct musb_request	*req;
791 	struct usb_request	*request;
792 	void __iomem		*mbase = musb->mregs;
793 	struct musb_ep		*musb_ep;
794 	void __iomem		*epio = musb->endpoints[epnum].regs;
795 	struct dma_channel	*dma;
796 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
797 
798 	if (hw_ep->is_shared_fifo)
799 		musb_ep = &hw_ep->ep_in;
800 	else
801 		musb_ep = &hw_ep->ep_out;
802 
803 	musb_ep_select(mbase, epnum);
804 
805 	req = next_request(musb_ep);
806 	if (!req)
807 		return;
808 
809 	trace_musb_req_rx(req);
810 	request = &req->request;
811 
812 	csr = musb_readw(epio, MUSB_RXCSR);
813 	dma = is_dma_capable() ? musb_ep->dma : NULL;
814 
815 	musb_dbg(musb, "<== %s, rxcsr %04x%s %p", musb_ep->end_point.name,
816 			csr, dma ? " (dma)" : "", request);
817 
818 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
819 		csr |= MUSB_RXCSR_P_WZC_BITS;
820 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
821 		musb_writew(epio, MUSB_RXCSR, csr);
822 		return;
823 	}
824 
825 	if (csr & MUSB_RXCSR_P_OVERRUN) {
826 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
827 		csr &= ~MUSB_RXCSR_P_OVERRUN;
828 		musb_writew(epio, MUSB_RXCSR, csr);
829 
830 		musb_dbg(musb, "%s iso overrun on %p", musb_ep->name, request);
831 		if (request->status == -EINPROGRESS)
832 			request->status = -EOVERFLOW;
833 	}
834 	if (csr & MUSB_RXCSR_INCOMPRX) {
835 		/* REVISIT not necessarily an error */
836 		musb_dbg(musb, "%s, incomprx", musb_ep->end_point.name);
837 	}
838 
839 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
840 		/* "should not happen"; likely RXPKTRDY pending for DMA */
841 		musb_dbg(musb, "%s busy, csr %04x",
842 			musb_ep->end_point.name, csr);
843 		return;
844 	}
845 
846 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
847 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
848 				| MUSB_RXCSR_DMAENAB
849 				| MUSB_RXCSR_DMAMODE);
850 		musb_writew(epio, MUSB_RXCSR,
851 			MUSB_RXCSR_P_WZC_BITS | csr);
852 
853 		request->actual += musb_ep->dma->actual_len;
854 
855 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
856 	defined(CONFIG_USB_UX500_DMA)
857 		/* Autoclear doesn't clear RxPktRdy for short packets */
858 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
859 				|| (dma->actual_len
860 					& (musb_ep->packet_sz - 1))) {
861 			/* ack the read! */
862 			csr &= ~MUSB_RXCSR_RXPKTRDY;
863 			musb_writew(epio, MUSB_RXCSR, csr);
864 		}
865 
866 		/* incomplete, and not short? wait for next IN packet */
867 		if ((request->actual < request->length)
868 				&& (musb_ep->dma->actual_len
869 					== musb_ep->packet_sz)) {
870 			/* In double buffer case, continue to unload fifo if
871  			 * there is Rx packet in FIFO.
872  			 **/
873 			csr = musb_readw(epio, MUSB_RXCSR);
874 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
875 				hw_ep->rx_double_buffered)
876 				goto exit;
877 			return;
878 		}
879 #endif
880 		musb_g_giveback(musb_ep, request, 0);
881 		/*
882 		 * In the giveback function the MUSB lock is
883 		 * released and acquired after sometime. During
884 		 * this time period the INDEX register could get
885 		 * changed by the gadget_queue function especially
886 		 * on SMP systems. Reselect the INDEX to be sure
887 		 * we are reading/modifying the right registers
888 		 */
889 		musb_ep_select(mbase, epnum);
890 
891 		req = next_request(musb_ep);
892 		if (!req)
893 			return;
894 	}
895 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
896 	defined(CONFIG_USB_UX500_DMA)
897 exit:
898 #endif
899 	/* Analyze request */
900 	rxstate(musb, req);
901 }
902 
903 /* ------------------------------------------------------------ */
904 
905 static int musb_gadget_enable(struct usb_ep *ep,
906 			const struct usb_endpoint_descriptor *desc)
907 {
908 	unsigned long		flags;
909 	struct musb_ep		*musb_ep;
910 	struct musb_hw_ep	*hw_ep;
911 	void __iomem		*regs;
912 	struct musb		*musb;
913 	void __iomem	*mbase;
914 	u8		epnum;
915 	u16		csr;
916 	unsigned	tmp;
917 	int		status = -EINVAL;
918 
919 	if (!ep || !desc)
920 		return -EINVAL;
921 
922 	musb_ep = to_musb_ep(ep);
923 	hw_ep = musb_ep->hw_ep;
924 	regs = hw_ep->regs;
925 	musb = musb_ep->musb;
926 	mbase = musb->mregs;
927 	epnum = musb_ep->current_epnum;
928 
929 	spin_lock_irqsave(&musb->lock, flags);
930 
931 	if (musb_ep->desc) {
932 		status = -EBUSY;
933 		goto fail;
934 	}
935 	musb_ep->type = usb_endpoint_type(desc);
936 
937 	/* check direction and (later) maxpacket size against endpoint */
938 	if (usb_endpoint_num(desc) != epnum)
939 		goto fail;
940 
941 	/* REVISIT this rules out high bandwidth periodic transfers */
942 	tmp = usb_endpoint_maxp_mult(desc) - 1;
943 	if (tmp) {
944 		int ok;
945 
946 		if (usb_endpoint_dir_in(desc))
947 			ok = musb->hb_iso_tx;
948 		else
949 			ok = musb->hb_iso_rx;
950 
951 		if (!ok) {
952 			musb_dbg(musb, "no support for high bandwidth ISO");
953 			goto fail;
954 		}
955 		musb_ep->hb_mult = tmp;
956 	} else {
957 		musb_ep->hb_mult = 0;
958 	}
959 
960 	musb_ep->packet_sz = usb_endpoint_maxp(desc);
961 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
962 
963 	/* enable the interrupts for the endpoint, set the endpoint
964 	 * packet size (or fail), set the mode, clear the fifo
965 	 */
966 	musb_ep_select(mbase, epnum);
967 	if (usb_endpoint_dir_in(desc)) {
968 
969 		if (hw_ep->is_shared_fifo)
970 			musb_ep->is_in = 1;
971 		if (!musb_ep->is_in)
972 			goto fail;
973 
974 		if (tmp > hw_ep->max_packet_sz_tx) {
975 			musb_dbg(musb, "packet size beyond hardware FIFO size");
976 			goto fail;
977 		}
978 
979 		musb->intrtxe |= (1 << epnum);
980 		musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
981 
982 		/* REVISIT if can_bulk_split(), use by updating "tmp";
983 		 * likewise high bandwidth periodic tx
984 		 */
985 		/* Set TXMAXP with the FIFO size of the endpoint
986 		 * to disable double buffering mode.
987 		 */
988 		if (can_bulk_split(musb, musb_ep->type))
989 			musb_ep->hb_mult = (hw_ep->max_packet_sz_tx /
990 						musb_ep->packet_sz) - 1;
991 		musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
992 				| (musb_ep->hb_mult << 11));
993 
994 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
995 		if (musb_readw(regs, MUSB_TXCSR)
996 				& MUSB_TXCSR_FIFONOTEMPTY)
997 			csr |= MUSB_TXCSR_FLUSHFIFO;
998 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
999 			csr |= MUSB_TXCSR_P_ISO;
1000 
1001 		/* set twice in case of double buffering */
1002 		musb_writew(regs, MUSB_TXCSR, csr);
1003 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1004 		musb_writew(regs, MUSB_TXCSR, csr);
1005 
1006 	} else {
1007 
1008 		if (hw_ep->is_shared_fifo)
1009 			musb_ep->is_in = 0;
1010 		if (musb_ep->is_in)
1011 			goto fail;
1012 
1013 		if (tmp > hw_ep->max_packet_sz_rx) {
1014 			musb_dbg(musb, "packet size beyond hardware FIFO size");
1015 			goto fail;
1016 		}
1017 
1018 		musb->intrrxe |= (1 << epnum);
1019 		musb_writew(mbase, MUSB_INTRRXE, musb->intrrxe);
1020 
1021 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1022 		 * likewise high bandwidth periodic rx
1023 		 */
1024 		/* Set RXMAXP with the FIFO size of the endpoint
1025 		 * to disable double buffering mode.
1026 		 */
1027 		musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1028 				| (musb_ep->hb_mult << 11));
1029 
1030 		/* force shared fifo to OUT-only mode */
1031 		if (hw_ep->is_shared_fifo) {
1032 			csr = musb_readw(regs, MUSB_TXCSR);
1033 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1034 			musb_writew(regs, MUSB_TXCSR, csr);
1035 		}
1036 
1037 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1038 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1039 			csr |= MUSB_RXCSR_P_ISO;
1040 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1041 			csr |= MUSB_RXCSR_DISNYET;
1042 
1043 		/* set twice in case of double buffering */
1044 		musb_writew(regs, MUSB_RXCSR, csr);
1045 		musb_writew(regs, MUSB_RXCSR, csr);
1046 	}
1047 
1048 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1049 	 * for some reason you run out of channels here.
1050 	 */
1051 	if (is_dma_capable() && musb->dma_controller) {
1052 		struct dma_controller	*c = musb->dma_controller;
1053 
1054 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1055 				(desc->bEndpointAddress & USB_DIR_IN));
1056 	} else
1057 		musb_ep->dma = NULL;
1058 
1059 	musb_ep->desc = desc;
1060 	musb_ep->busy = 0;
1061 	musb_ep->wedged = 0;
1062 	status = 0;
1063 
1064 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1065 			musb_driver_name, musb_ep->end_point.name,
1066 			musb_ep_xfertype_string(musb_ep->type),
1067 			musb_ep->is_in ? "IN" : "OUT",
1068 			musb_ep->dma ? "dma, " : "",
1069 			musb_ep->packet_sz);
1070 
1071 	schedule_delayed_work(&musb->irq_work, 0);
1072 
1073 fail:
1074 	spin_unlock_irqrestore(&musb->lock, flags);
1075 	return status;
1076 }
1077 
1078 /*
1079  * Disable an endpoint flushing all requests queued.
1080  */
1081 static int musb_gadget_disable(struct usb_ep *ep)
1082 {
1083 	unsigned long	flags;
1084 	struct musb	*musb;
1085 	u8		epnum;
1086 	struct musb_ep	*musb_ep;
1087 	void __iomem	*epio;
1088 
1089 	musb_ep = to_musb_ep(ep);
1090 	musb = musb_ep->musb;
1091 	epnum = musb_ep->current_epnum;
1092 	epio = musb->endpoints[epnum].regs;
1093 
1094 	spin_lock_irqsave(&musb->lock, flags);
1095 	musb_ep_select(musb->mregs, epnum);
1096 
1097 	/* zero the endpoint sizes */
1098 	if (musb_ep->is_in) {
1099 		musb->intrtxe &= ~(1 << epnum);
1100 		musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
1101 		musb_writew(epio, MUSB_TXMAXP, 0);
1102 	} else {
1103 		musb->intrrxe &= ~(1 << epnum);
1104 		musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
1105 		musb_writew(epio, MUSB_RXMAXP, 0);
1106 	}
1107 
1108 	/* abort all pending DMA and requests */
1109 	nuke(musb_ep, -ESHUTDOWN);
1110 
1111 	musb_ep->desc = NULL;
1112 	musb_ep->end_point.desc = NULL;
1113 
1114 	schedule_delayed_work(&musb->irq_work, 0);
1115 
1116 	spin_unlock_irqrestore(&(musb->lock), flags);
1117 
1118 	musb_dbg(musb, "%s", musb_ep->end_point.name);
1119 
1120 	return 0;
1121 }
1122 
1123 /*
1124  * Allocate a request for an endpoint.
1125  * Reused by ep0 code.
1126  */
1127 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1128 {
1129 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1130 	struct musb_request	*request = NULL;
1131 
1132 	request = kzalloc(sizeof *request, gfp_flags);
1133 	if (!request)
1134 		return NULL;
1135 
1136 	request->request.dma = DMA_ADDR_INVALID;
1137 	request->epnum = musb_ep->current_epnum;
1138 	request->ep = musb_ep;
1139 
1140 	trace_musb_req_alloc(request);
1141 	return &request->request;
1142 }
1143 
1144 /*
1145  * Free a request
1146  * Reused by ep0 code.
1147  */
1148 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1149 {
1150 	struct musb_request *request = to_musb_request(req);
1151 
1152 	trace_musb_req_free(request);
1153 	kfree(request);
1154 }
1155 
1156 static LIST_HEAD(buffers);
1157 
1158 struct free_record {
1159 	struct list_head	list;
1160 	struct device		*dev;
1161 	unsigned		bytes;
1162 	dma_addr_t		dma;
1163 };
1164 
1165 /*
1166  * Context: controller locked, IRQs blocked.
1167  */
1168 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1169 {
1170 	trace_musb_req_start(req);
1171 	musb_ep_select(musb->mregs, req->epnum);
1172 	if (req->tx)
1173 		txstate(musb, req);
1174 	else
1175 		rxstate(musb, req);
1176 }
1177 
1178 static int musb_ep_restart_resume_work(struct musb *musb, void *data)
1179 {
1180 	struct musb_request *req = data;
1181 
1182 	musb_ep_restart(musb, req);
1183 
1184 	return 0;
1185 }
1186 
1187 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1188 			gfp_t gfp_flags)
1189 {
1190 	struct musb_ep		*musb_ep;
1191 	struct musb_request	*request;
1192 	struct musb		*musb;
1193 	int			status;
1194 	unsigned long		lockflags;
1195 
1196 	if (!ep || !req)
1197 		return -EINVAL;
1198 	if (!req->buf)
1199 		return -ENODATA;
1200 
1201 	musb_ep = to_musb_ep(ep);
1202 	musb = musb_ep->musb;
1203 
1204 	request = to_musb_request(req);
1205 	request->musb = musb;
1206 
1207 	if (request->ep != musb_ep)
1208 		return -EINVAL;
1209 
1210 	status = pm_runtime_get(musb->controller);
1211 	if ((status != -EINPROGRESS) && status < 0) {
1212 		dev_err(musb->controller,
1213 			"pm runtime get failed in %s\n",
1214 			__func__);
1215 		pm_runtime_put_noidle(musb->controller);
1216 
1217 		return status;
1218 	}
1219 	status = 0;
1220 
1221 	trace_musb_req_enq(request);
1222 
1223 	/* request is mine now... */
1224 	request->request.actual = 0;
1225 	request->request.status = -EINPROGRESS;
1226 	request->epnum = musb_ep->current_epnum;
1227 	request->tx = musb_ep->is_in;
1228 
1229 	map_dma_buffer(request, musb, musb_ep);
1230 
1231 	spin_lock_irqsave(&musb->lock, lockflags);
1232 
1233 	/* don't queue if the ep is down */
1234 	if (!musb_ep->desc) {
1235 		musb_dbg(musb, "req %p queued to %s while ep %s",
1236 				req, ep->name, "disabled");
1237 		status = -ESHUTDOWN;
1238 		unmap_dma_buffer(request, musb);
1239 		goto unlock;
1240 	}
1241 
1242 	/* add request to the list */
1243 	list_add_tail(&request->list, &musb_ep->req_list);
1244 
1245 	/* it this is the head of the queue, start i/o ... */
1246 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next) {
1247 		status = musb_queue_resume_work(musb,
1248 						musb_ep_restart_resume_work,
1249 						request);
1250 		if (status < 0) {
1251 			dev_err(musb->controller, "%s resume work: %i\n",
1252 				__func__, status);
1253 			list_del(&request->list);
1254 		}
1255 	}
1256 
1257 unlock:
1258 	spin_unlock_irqrestore(&musb->lock, lockflags);
1259 	pm_runtime_mark_last_busy(musb->controller);
1260 	pm_runtime_put_autosuspend(musb->controller);
1261 
1262 	return status;
1263 }
1264 
1265 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1266 {
1267 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1268 	struct musb_request	*req = to_musb_request(request);
1269 	struct musb_request	*r;
1270 	unsigned long		flags;
1271 	int			status = 0;
1272 	struct musb		*musb = musb_ep->musb;
1273 
1274 	if (!ep || !request || req->ep != musb_ep)
1275 		return -EINVAL;
1276 
1277 	trace_musb_req_deq(req);
1278 
1279 	spin_lock_irqsave(&musb->lock, flags);
1280 
1281 	list_for_each_entry(r, &musb_ep->req_list, list) {
1282 		if (r == req)
1283 			break;
1284 	}
1285 	if (r != req) {
1286 		dev_err(musb->controller, "request %p not queued to %s\n",
1287 				request, ep->name);
1288 		status = -EINVAL;
1289 		goto done;
1290 	}
1291 
1292 	/* if the hardware doesn't have the request, easy ... */
1293 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1294 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1295 
1296 	/* ... else abort the dma transfer ... */
1297 	else if (is_dma_capable() && musb_ep->dma) {
1298 		struct dma_controller	*c = musb->dma_controller;
1299 
1300 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1301 		if (c->channel_abort)
1302 			status = c->channel_abort(musb_ep->dma);
1303 		else
1304 			status = -EBUSY;
1305 		if (status == 0)
1306 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1307 	} else {
1308 		/* NOTE: by sticking to easily tested hardware/driver states,
1309 		 * we leave counting of in-flight packets imprecise.
1310 		 */
1311 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1312 	}
1313 
1314 done:
1315 	spin_unlock_irqrestore(&musb->lock, flags);
1316 	return status;
1317 }
1318 
1319 /*
1320  * Set or clear the halt bit of an endpoint. A halted endpoint won't tx/rx any
1321  * data but will queue requests.
1322  *
1323  * exported to ep0 code
1324  */
1325 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1326 {
1327 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1328 	u8			epnum = musb_ep->current_epnum;
1329 	struct musb		*musb = musb_ep->musb;
1330 	void __iomem		*epio = musb->endpoints[epnum].regs;
1331 	void __iomem		*mbase;
1332 	unsigned long		flags;
1333 	u16			csr;
1334 	struct musb_request	*request;
1335 	int			status = 0;
1336 
1337 	if (!ep)
1338 		return -EINVAL;
1339 	mbase = musb->mregs;
1340 
1341 	spin_lock_irqsave(&musb->lock, flags);
1342 
1343 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1344 		status = -EINVAL;
1345 		goto done;
1346 	}
1347 
1348 	musb_ep_select(mbase, epnum);
1349 
1350 	request = next_request(musb_ep);
1351 	if (value) {
1352 		if (request) {
1353 			musb_dbg(musb, "request in progress, cannot halt %s",
1354 			    ep->name);
1355 			status = -EAGAIN;
1356 			goto done;
1357 		}
1358 		/* Cannot portably stall with non-empty FIFO */
1359 		if (musb_ep->is_in) {
1360 			csr = musb_readw(epio, MUSB_TXCSR);
1361 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1362 				musb_dbg(musb, "FIFO busy, cannot halt %s",
1363 						ep->name);
1364 				status = -EAGAIN;
1365 				goto done;
1366 			}
1367 		}
1368 	} else
1369 		musb_ep->wedged = 0;
1370 
1371 	/* set/clear the stall and toggle bits */
1372 	musb_dbg(musb, "%s: %s stall", ep->name, value ? "set" : "clear");
1373 	if (musb_ep->is_in) {
1374 		csr = musb_readw(epio, MUSB_TXCSR);
1375 		csr |= MUSB_TXCSR_P_WZC_BITS
1376 			| MUSB_TXCSR_CLRDATATOG;
1377 		if (value)
1378 			csr |= MUSB_TXCSR_P_SENDSTALL;
1379 		else
1380 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1381 				| MUSB_TXCSR_P_SENTSTALL);
1382 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1383 		musb_writew(epio, MUSB_TXCSR, csr);
1384 	} else {
1385 		csr = musb_readw(epio, MUSB_RXCSR);
1386 		csr |= MUSB_RXCSR_P_WZC_BITS
1387 			| MUSB_RXCSR_FLUSHFIFO
1388 			| MUSB_RXCSR_CLRDATATOG;
1389 		if (value)
1390 			csr |= MUSB_RXCSR_P_SENDSTALL;
1391 		else
1392 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1393 				| MUSB_RXCSR_P_SENTSTALL);
1394 		musb_writew(epio, MUSB_RXCSR, csr);
1395 	}
1396 
1397 	/* maybe start the first request in the queue */
1398 	if (!musb_ep->busy && !value && request) {
1399 		musb_dbg(musb, "restarting the request");
1400 		musb_ep_restart(musb, request);
1401 	}
1402 
1403 done:
1404 	spin_unlock_irqrestore(&musb->lock, flags);
1405 	return status;
1406 }
1407 
1408 /*
1409  * Sets the halt feature with the clear requests ignored
1410  */
1411 static int musb_gadget_set_wedge(struct usb_ep *ep)
1412 {
1413 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1414 
1415 	if (!ep)
1416 		return -EINVAL;
1417 
1418 	musb_ep->wedged = 1;
1419 
1420 	return usb_ep_set_halt(ep);
1421 }
1422 
1423 static int musb_gadget_fifo_status(struct usb_ep *ep)
1424 {
1425 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1426 	void __iomem		*epio = musb_ep->hw_ep->regs;
1427 	int			retval = -EINVAL;
1428 
1429 	if (musb_ep->desc && !musb_ep->is_in) {
1430 		struct musb		*musb = musb_ep->musb;
1431 		int			epnum = musb_ep->current_epnum;
1432 		void __iomem		*mbase = musb->mregs;
1433 		unsigned long		flags;
1434 
1435 		spin_lock_irqsave(&musb->lock, flags);
1436 
1437 		musb_ep_select(mbase, epnum);
1438 		/* FIXME return zero unless RXPKTRDY is set */
1439 		retval = musb_readw(epio, MUSB_RXCOUNT);
1440 
1441 		spin_unlock_irqrestore(&musb->lock, flags);
1442 	}
1443 	return retval;
1444 }
1445 
1446 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1447 {
1448 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1449 	struct musb	*musb = musb_ep->musb;
1450 	u8		epnum = musb_ep->current_epnum;
1451 	void __iomem	*epio = musb->endpoints[epnum].regs;
1452 	void __iomem	*mbase;
1453 	unsigned long	flags;
1454 	u16		csr;
1455 
1456 	mbase = musb->mregs;
1457 
1458 	spin_lock_irqsave(&musb->lock, flags);
1459 	musb_ep_select(mbase, (u8) epnum);
1460 
1461 	/* disable interrupts */
1462 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe & ~(1 << epnum));
1463 
1464 	if (musb_ep->is_in) {
1465 		csr = musb_readw(epio, MUSB_TXCSR);
1466 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1467 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1468 			/*
1469 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1470 			 * to interrupt current FIFO loading, but not flushing
1471 			 * the already loaded ones.
1472 			 */
1473 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1474 			musb_writew(epio, MUSB_TXCSR, csr);
1475 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1476 			musb_writew(epio, MUSB_TXCSR, csr);
1477 		}
1478 	} else {
1479 		csr = musb_readw(epio, MUSB_RXCSR);
1480 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1481 		musb_writew(epio, MUSB_RXCSR, csr);
1482 		musb_writew(epio, MUSB_RXCSR, csr);
1483 	}
1484 
1485 	/* re-enable interrupt */
1486 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
1487 	spin_unlock_irqrestore(&musb->lock, flags);
1488 }
1489 
1490 static const struct usb_ep_ops musb_ep_ops = {
1491 	.enable		= musb_gadget_enable,
1492 	.disable	= musb_gadget_disable,
1493 	.alloc_request	= musb_alloc_request,
1494 	.free_request	= musb_free_request,
1495 	.queue		= musb_gadget_queue,
1496 	.dequeue	= musb_gadget_dequeue,
1497 	.set_halt	= musb_gadget_set_halt,
1498 	.set_wedge	= musb_gadget_set_wedge,
1499 	.fifo_status	= musb_gadget_fifo_status,
1500 	.fifo_flush	= musb_gadget_fifo_flush
1501 };
1502 
1503 /* ----------------------------------------------------------------------- */
1504 
1505 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1506 {
1507 	struct musb	*musb = gadget_to_musb(gadget);
1508 
1509 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1510 }
1511 
1512 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1513 {
1514 	struct musb	*musb = gadget_to_musb(gadget);
1515 	void __iomem	*mregs = musb->mregs;
1516 	unsigned long	flags;
1517 	int		status = -EINVAL;
1518 	u8		power, devctl;
1519 	int		retries;
1520 
1521 	spin_lock_irqsave(&musb->lock, flags);
1522 
1523 	switch (musb->xceiv->otg->state) {
1524 	case OTG_STATE_B_PERIPHERAL:
1525 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1526 		 * that's part of the standard usb 1.1 state machine, and
1527 		 * doesn't affect OTG transitions.
1528 		 */
1529 		if (musb->may_wakeup && musb->is_suspended)
1530 			break;
1531 		goto done;
1532 	case OTG_STATE_B_IDLE:
1533 		/* Start SRP ... OTG not required. */
1534 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1535 		musb_dbg(musb, "Sending SRP: devctl: %02x", devctl);
1536 		devctl |= MUSB_DEVCTL_SESSION;
1537 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1538 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1539 		retries = 100;
1540 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1541 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1542 			if (retries-- < 1)
1543 				break;
1544 		}
1545 		retries = 10000;
1546 		while (devctl & MUSB_DEVCTL_SESSION) {
1547 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1548 			if (retries-- < 1)
1549 				break;
1550 		}
1551 
1552 		spin_unlock_irqrestore(&musb->lock, flags);
1553 		otg_start_srp(musb->xceiv->otg);
1554 		spin_lock_irqsave(&musb->lock, flags);
1555 
1556 		/* Block idling for at least 1s */
1557 		musb_platform_try_idle(musb,
1558 			jiffies + msecs_to_jiffies(1 * HZ));
1559 
1560 		status = 0;
1561 		goto done;
1562 	default:
1563 		musb_dbg(musb, "Unhandled wake: %s",
1564 			usb_otg_state_string(musb->xceiv->otg->state));
1565 		goto done;
1566 	}
1567 
1568 	status = 0;
1569 
1570 	power = musb_readb(mregs, MUSB_POWER);
1571 	power |= MUSB_POWER_RESUME;
1572 	musb_writeb(mregs, MUSB_POWER, power);
1573 	musb_dbg(musb, "issue wakeup");
1574 
1575 	/* FIXME do this next chunk in a timer callback, no udelay */
1576 	mdelay(2);
1577 
1578 	power = musb_readb(mregs, MUSB_POWER);
1579 	power &= ~MUSB_POWER_RESUME;
1580 	musb_writeb(mregs, MUSB_POWER, power);
1581 done:
1582 	spin_unlock_irqrestore(&musb->lock, flags);
1583 	return status;
1584 }
1585 
1586 static int
1587 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1588 {
1589 	gadget->is_selfpowered = !!is_selfpowered;
1590 	return 0;
1591 }
1592 
1593 static void musb_pullup(struct musb *musb, int is_on)
1594 {
1595 	u8 power;
1596 
1597 	power = musb_readb(musb->mregs, MUSB_POWER);
1598 	if (is_on)
1599 		power |= MUSB_POWER_SOFTCONN;
1600 	else
1601 		power &= ~MUSB_POWER_SOFTCONN;
1602 
1603 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1604 
1605 	musb_dbg(musb, "gadget D+ pullup %s",
1606 		is_on ? "on" : "off");
1607 	musb_writeb(musb->mregs, MUSB_POWER, power);
1608 }
1609 
1610 #if 0
1611 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1612 {
1613 	musb_dbg(musb, "<= %s =>\n", __func__);
1614 
1615 	/*
1616 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1617 	 * though that can clear it), just musb_pullup().
1618 	 */
1619 
1620 	return -EINVAL;
1621 }
1622 #endif
1623 
1624 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1625 {
1626 	struct musb	*musb = gadget_to_musb(gadget);
1627 
1628 	if (!musb->xceiv->set_power)
1629 		return -EOPNOTSUPP;
1630 	return usb_phy_set_power(musb->xceiv, mA);
1631 }
1632 
1633 static void musb_gadget_work(struct work_struct *work)
1634 {
1635 	struct musb *musb;
1636 	unsigned long flags;
1637 
1638 	musb = container_of(work, struct musb, gadget_work.work);
1639 	pm_runtime_get_sync(musb->controller);
1640 	spin_lock_irqsave(&musb->lock, flags);
1641 	musb_pullup(musb, musb->softconnect);
1642 	spin_unlock_irqrestore(&musb->lock, flags);
1643 	pm_runtime_mark_last_busy(musb->controller);
1644 	pm_runtime_put_autosuspend(musb->controller);
1645 }
1646 
1647 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1648 {
1649 	struct musb	*musb = gadget_to_musb(gadget);
1650 	unsigned long	flags;
1651 
1652 	is_on = !!is_on;
1653 
1654 	/* NOTE: this assumes we are sensing vbus; we'd rather
1655 	 * not pullup unless the B-session is active.
1656 	 */
1657 	spin_lock_irqsave(&musb->lock, flags);
1658 	if (is_on != musb->softconnect) {
1659 		musb->softconnect = is_on;
1660 		schedule_delayed_work(&musb->gadget_work, 0);
1661 	}
1662 	spin_unlock_irqrestore(&musb->lock, flags);
1663 
1664 	return 0;
1665 }
1666 
1667 static int musb_gadget_start(struct usb_gadget *g,
1668 		struct usb_gadget_driver *driver);
1669 static int musb_gadget_stop(struct usb_gadget *g);
1670 
1671 static const struct usb_gadget_ops musb_gadget_operations = {
1672 	.get_frame		= musb_gadget_get_frame,
1673 	.wakeup			= musb_gadget_wakeup,
1674 	.set_selfpowered	= musb_gadget_set_self_powered,
1675 	/* .vbus_session		= musb_gadget_vbus_session, */
1676 	.vbus_draw		= musb_gadget_vbus_draw,
1677 	.pullup			= musb_gadget_pullup,
1678 	.udc_start		= musb_gadget_start,
1679 	.udc_stop		= musb_gadget_stop,
1680 };
1681 
1682 /* ----------------------------------------------------------------------- */
1683 
1684 /* Registration */
1685 
1686 /* Only this registration code "knows" the rule (from USB standards)
1687  * about there being only one external upstream port.  It assumes
1688  * all peripheral ports are external...
1689  */
1690 
1691 static void
1692 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1693 {
1694 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1695 
1696 	memset(ep, 0, sizeof *ep);
1697 
1698 	ep->current_epnum = epnum;
1699 	ep->musb = musb;
1700 	ep->hw_ep = hw_ep;
1701 	ep->is_in = is_in;
1702 
1703 	INIT_LIST_HEAD(&ep->req_list);
1704 
1705 	sprintf(ep->name, "ep%d%s", epnum,
1706 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1707 				is_in ? "in" : "out"));
1708 	ep->end_point.name = ep->name;
1709 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1710 	if (!epnum) {
1711 		usb_ep_set_maxpacket_limit(&ep->end_point, 64);
1712 		ep->end_point.caps.type_control = true;
1713 		ep->end_point.ops = &musb_g_ep0_ops;
1714 		musb->g.ep0 = &ep->end_point;
1715 	} else {
1716 		if (is_in)
1717 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_tx);
1718 		else
1719 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_rx);
1720 		ep->end_point.caps.type_iso = true;
1721 		ep->end_point.caps.type_bulk = true;
1722 		ep->end_point.caps.type_int = true;
1723 		ep->end_point.ops = &musb_ep_ops;
1724 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1725 	}
1726 
1727 	if (!epnum || hw_ep->is_shared_fifo) {
1728 		ep->end_point.caps.dir_in = true;
1729 		ep->end_point.caps.dir_out = true;
1730 	} else if (is_in)
1731 		ep->end_point.caps.dir_in = true;
1732 	else
1733 		ep->end_point.caps.dir_out = true;
1734 }
1735 
1736 /*
1737  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1738  * to the rest of the driver state.
1739  */
1740 static inline void musb_g_init_endpoints(struct musb *musb)
1741 {
1742 	u8			epnum;
1743 	struct musb_hw_ep	*hw_ep;
1744 	unsigned		count = 0;
1745 
1746 	/* initialize endpoint list just once */
1747 	INIT_LIST_HEAD(&(musb->g.ep_list));
1748 
1749 	for (epnum = 0, hw_ep = musb->endpoints;
1750 			epnum < musb->nr_endpoints;
1751 			epnum++, hw_ep++) {
1752 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1753 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1754 			count++;
1755 		} else {
1756 			if (hw_ep->max_packet_sz_tx) {
1757 				init_peripheral_ep(musb, &hw_ep->ep_in,
1758 							epnum, 1);
1759 				count++;
1760 			}
1761 			if (hw_ep->max_packet_sz_rx) {
1762 				init_peripheral_ep(musb, &hw_ep->ep_out,
1763 							epnum, 0);
1764 				count++;
1765 			}
1766 		}
1767 	}
1768 }
1769 
1770 /* called once during driver setup to initialize and link into
1771  * the driver model; memory is zeroed.
1772  */
1773 int musb_gadget_setup(struct musb *musb)
1774 {
1775 	int status;
1776 
1777 	/* REVISIT minor race:  if (erroneously) setting up two
1778 	 * musb peripherals at the same time, only the bus lock
1779 	 * is probably held.
1780 	 */
1781 
1782 	musb->g.ops = &musb_gadget_operations;
1783 	musb->g.max_speed = USB_SPEED_HIGH;
1784 	musb->g.speed = USB_SPEED_UNKNOWN;
1785 
1786 	MUSB_DEV_MODE(musb);
1787 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1788 
1789 	/* this "gadget" abstracts/virtualizes the controller */
1790 	musb->g.name = musb_driver_name;
1791 	/* don't support otg protocols */
1792 	musb->g.is_otg = 0;
1793 	INIT_DELAYED_WORK(&musb->gadget_work, musb_gadget_work);
1794 	musb_g_init_endpoints(musb);
1795 
1796 	musb->is_active = 0;
1797 	musb_platform_try_idle(musb, 0);
1798 
1799 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1800 	if (status)
1801 		goto err;
1802 
1803 	return 0;
1804 err:
1805 	musb->g.dev.parent = NULL;
1806 	device_unregister(&musb->g.dev);
1807 	return status;
1808 }
1809 
1810 void musb_gadget_cleanup(struct musb *musb)
1811 {
1812 	if (musb->port_mode == MUSB_HOST)
1813 		return;
1814 
1815 	cancel_delayed_work_sync(&musb->gadget_work);
1816 	usb_del_gadget_udc(&musb->g);
1817 }
1818 
1819 /*
1820  * Register the gadget driver. Used by gadget drivers when
1821  * registering themselves with the controller.
1822  *
1823  * -EINVAL something went wrong (not driver)
1824  * -EBUSY another gadget is already using the controller
1825  * -ENOMEM no memory to perform the operation
1826  *
1827  * @param driver the gadget driver
1828  * @return <0 if error, 0 if everything is fine
1829  */
1830 static int musb_gadget_start(struct usb_gadget *g,
1831 		struct usb_gadget_driver *driver)
1832 {
1833 	struct musb		*musb = gadget_to_musb(g);
1834 	struct usb_otg		*otg = musb->xceiv->otg;
1835 	unsigned long		flags;
1836 	int			retval = 0;
1837 
1838 	if (driver->max_speed < USB_SPEED_HIGH) {
1839 		retval = -EINVAL;
1840 		goto err;
1841 	}
1842 
1843 	pm_runtime_get_sync(musb->controller);
1844 
1845 	musb->softconnect = 0;
1846 	musb->gadget_driver = driver;
1847 
1848 	spin_lock_irqsave(&musb->lock, flags);
1849 	musb->is_active = 1;
1850 
1851 	otg_set_peripheral(otg, &musb->g);
1852 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1853 	spin_unlock_irqrestore(&musb->lock, flags);
1854 
1855 	musb_start(musb);
1856 
1857 	/* REVISIT:  funcall to other code, which also
1858 	 * handles power budgeting ... this way also
1859 	 * ensures HdrcStart is indirectly called.
1860 	 */
1861 	if (musb->xceiv->last_event == USB_EVENT_ID)
1862 		musb_platform_set_vbus(musb, 1);
1863 
1864 	pm_runtime_mark_last_busy(musb->controller);
1865 	pm_runtime_put_autosuspend(musb->controller);
1866 
1867 	return 0;
1868 
1869 err:
1870 	return retval;
1871 }
1872 
1873 /*
1874  * Unregister the gadget driver. Used by gadget drivers when
1875  * unregistering themselves from the controller.
1876  *
1877  * @param driver the gadget driver to unregister
1878  */
1879 static int musb_gadget_stop(struct usb_gadget *g)
1880 {
1881 	struct musb	*musb = gadget_to_musb(g);
1882 	unsigned long	flags;
1883 
1884 	pm_runtime_get_sync(musb->controller);
1885 
1886 	/*
1887 	 * REVISIT always use otg_set_peripheral() here too;
1888 	 * this needs to shut down the OTG engine.
1889 	 */
1890 
1891 	spin_lock_irqsave(&musb->lock, flags);
1892 
1893 	musb_hnp_stop(musb);
1894 
1895 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1896 
1897 	musb->xceiv->otg->state = OTG_STATE_UNDEFINED;
1898 	musb_stop(musb);
1899 	otg_set_peripheral(musb->xceiv->otg, NULL);
1900 
1901 	musb->is_active = 0;
1902 	musb->gadget_driver = NULL;
1903 	musb_platform_try_idle(musb, 0);
1904 	spin_unlock_irqrestore(&musb->lock, flags);
1905 
1906 	/*
1907 	 * FIXME we need to be able to register another
1908 	 * gadget driver here and have everything work;
1909 	 * that currently misbehaves.
1910 	 */
1911 
1912 	/* Force check of devctl register for PM runtime */
1913 	schedule_delayed_work(&musb->irq_work, 0);
1914 
1915 	pm_runtime_mark_last_busy(musb->controller);
1916 	pm_runtime_put_autosuspend(musb->controller);
1917 
1918 	return 0;
1919 }
1920 
1921 /* ----------------------------------------------------------------------- */
1922 
1923 /* lifecycle operations called through plat_uds.c */
1924 
1925 void musb_g_resume(struct musb *musb)
1926 {
1927 	musb->is_suspended = 0;
1928 	switch (musb->xceiv->otg->state) {
1929 	case OTG_STATE_B_IDLE:
1930 		break;
1931 	case OTG_STATE_B_WAIT_ACON:
1932 	case OTG_STATE_B_PERIPHERAL:
1933 		musb->is_active = 1;
1934 		if (musb->gadget_driver && musb->gadget_driver->resume) {
1935 			spin_unlock(&musb->lock);
1936 			musb->gadget_driver->resume(&musb->g);
1937 			spin_lock(&musb->lock);
1938 		}
1939 		break;
1940 	default:
1941 		WARNING("unhandled RESUME transition (%s)\n",
1942 				usb_otg_state_string(musb->xceiv->otg->state));
1943 	}
1944 }
1945 
1946 /* called when SOF packets stop for 3+ msec */
1947 void musb_g_suspend(struct musb *musb)
1948 {
1949 	u8	devctl;
1950 
1951 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
1952 	musb_dbg(musb, "musb_g_suspend: devctl %02x", devctl);
1953 
1954 	switch (musb->xceiv->otg->state) {
1955 	case OTG_STATE_B_IDLE:
1956 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
1957 			musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
1958 		break;
1959 	case OTG_STATE_B_PERIPHERAL:
1960 		musb->is_suspended = 1;
1961 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
1962 			spin_unlock(&musb->lock);
1963 			musb->gadget_driver->suspend(&musb->g);
1964 			spin_lock(&musb->lock);
1965 		}
1966 		break;
1967 	default:
1968 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
1969 		 * A_PERIPHERAL may need care too
1970 		 */
1971 		WARNING("unhandled SUSPEND transition (%s)",
1972 				usb_otg_state_string(musb->xceiv->otg->state));
1973 	}
1974 }
1975 
1976 /* Called during SRP */
1977 void musb_g_wakeup(struct musb *musb)
1978 {
1979 	musb_gadget_wakeup(&musb->g);
1980 }
1981 
1982 /* called when VBUS drops below session threshold, and in other cases */
1983 void musb_g_disconnect(struct musb *musb)
1984 {
1985 	void __iomem	*mregs = musb->mregs;
1986 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
1987 
1988 	musb_dbg(musb, "musb_g_disconnect: devctl %02x", devctl);
1989 
1990 	/* clear HR */
1991 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
1992 
1993 	/* don't draw vbus until new b-default session */
1994 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1995 
1996 	musb->g.speed = USB_SPEED_UNKNOWN;
1997 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
1998 		spin_unlock(&musb->lock);
1999 		musb->gadget_driver->disconnect(&musb->g);
2000 		spin_lock(&musb->lock);
2001 	}
2002 
2003 	switch (musb->xceiv->otg->state) {
2004 	default:
2005 		musb_dbg(musb, "Unhandled disconnect %s, setting a_idle",
2006 			usb_otg_state_string(musb->xceiv->otg->state));
2007 		musb->xceiv->otg->state = OTG_STATE_A_IDLE;
2008 		MUSB_HST_MODE(musb);
2009 		break;
2010 	case OTG_STATE_A_PERIPHERAL:
2011 		musb->xceiv->otg->state = OTG_STATE_A_WAIT_BCON;
2012 		MUSB_HST_MODE(musb);
2013 		break;
2014 	case OTG_STATE_B_WAIT_ACON:
2015 	case OTG_STATE_B_HOST:
2016 	case OTG_STATE_B_PERIPHERAL:
2017 	case OTG_STATE_B_IDLE:
2018 		musb->xceiv->otg->state = OTG_STATE_B_IDLE;
2019 		break;
2020 	case OTG_STATE_B_SRP_INIT:
2021 		break;
2022 	}
2023 
2024 	musb->is_active = 0;
2025 }
2026 
2027 void musb_g_reset(struct musb *musb)
2028 __releases(musb->lock)
2029 __acquires(musb->lock)
2030 {
2031 	void __iomem	*mbase = musb->mregs;
2032 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2033 	u8		power;
2034 
2035 	musb_dbg(musb, "<== %s driver '%s'",
2036 			(devctl & MUSB_DEVCTL_BDEVICE)
2037 				? "B-Device" : "A-Device",
2038 			musb->gadget_driver
2039 				? musb->gadget_driver->driver.name
2040 				: NULL
2041 			);
2042 
2043 	/* report reset, if we didn't already (flushing EP state) */
2044 	if (musb->gadget_driver && musb->g.speed != USB_SPEED_UNKNOWN) {
2045 		spin_unlock(&musb->lock);
2046 		usb_gadget_udc_reset(&musb->g, musb->gadget_driver);
2047 		spin_lock(&musb->lock);
2048 	}
2049 
2050 	/* clear HR */
2051 	else if (devctl & MUSB_DEVCTL_HR)
2052 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2053 
2054 
2055 	/* what speed did we negotiate? */
2056 	power = musb_readb(mbase, MUSB_POWER);
2057 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2058 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2059 
2060 	/* start in USB_STATE_DEFAULT */
2061 	musb->is_active = 1;
2062 	musb->is_suspended = 0;
2063 	MUSB_DEV_MODE(musb);
2064 	musb->address = 0;
2065 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2066 
2067 	musb->may_wakeup = 0;
2068 	musb->g.b_hnp_enable = 0;
2069 	musb->g.a_alt_hnp_support = 0;
2070 	musb->g.a_hnp_support = 0;
2071 	musb->g.quirk_zlp_not_supp = 1;
2072 
2073 	/* Normal reset, as B-Device;
2074 	 * or else after HNP, as A-Device
2075 	 */
2076 	if (!musb->g.is_otg) {
2077 		/* USB device controllers that are not OTG compatible
2078 		 * may not have DEVCTL register in silicon.
2079 		 * In that case, do not rely on devctl for setting
2080 		 * peripheral mode.
2081 		 */
2082 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2083 		musb->g.is_a_peripheral = 0;
2084 	} else if (devctl & MUSB_DEVCTL_BDEVICE) {
2085 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2086 		musb->g.is_a_peripheral = 0;
2087 	} else {
2088 		musb->xceiv->otg->state = OTG_STATE_A_PERIPHERAL;
2089 		musb->g.is_a_peripheral = 1;
2090 	}
2091 
2092 	/* start with default limits on VBUS power draw */
2093 	(void) musb_gadget_vbus_draw(&musb->g, 8);
2094 }
2095