xref: /openbmc/linux/drivers/usb/musb/musb_gadget.c (revision b830f94f)
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 (request) {
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 tranfer
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 	int		status = 0;
1089 
1090 	musb_ep = to_musb_ep(ep);
1091 	musb = musb_ep->musb;
1092 	epnum = musb_ep->current_epnum;
1093 	epio = musb->endpoints[epnum].regs;
1094 
1095 	spin_lock_irqsave(&musb->lock, flags);
1096 	musb_ep_select(musb->mregs, epnum);
1097 
1098 	/* zero the endpoint sizes */
1099 	if (musb_ep->is_in) {
1100 		musb->intrtxe &= ~(1 << epnum);
1101 		musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
1102 		musb_writew(epio, MUSB_TXMAXP, 0);
1103 	} else {
1104 		musb->intrrxe &= ~(1 << epnum);
1105 		musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
1106 		musb_writew(epio, MUSB_RXMAXP, 0);
1107 	}
1108 
1109 	/* abort all pending DMA and requests */
1110 	nuke(musb_ep, -ESHUTDOWN);
1111 
1112 	musb_ep->desc = NULL;
1113 	musb_ep->end_point.desc = NULL;
1114 
1115 	schedule_delayed_work(&musb->irq_work, 0);
1116 
1117 	spin_unlock_irqrestore(&(musb->lock), flags);
1118 
1119 	musb_dbg(musb, "%s", musb_ep->end_point.name);
1120 
1121 	return status;
1122 }
1123 
1124 /*
1125  * Allocate a request for an endpoint.
1126  * Reused by ep0 code.
1127  */
1128 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1129 {
1130 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1131 	struct musb_request	*request = NULL;
1132 
1133 	request = kzalloc(sizeof *request, gfp_flags);
1134 	if (!request)
1135 		return NULL;
1136 
1137 	request->request.dma = DMA_ADDR_INVALID;
1138 	request->epnum = musb_ep->current_epnum;
1139 	request->ep = musb_ep;
1140 
1141 	trace_musb_req_alloc(request);
1142 	return &request->request;
1143 }
1144 
1145 /*
1146  * Free a request
1147  * Reused by ep0 code.
1148  */
1149 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1150 {
1151 	struct musb_request *request = to_musb_request(req);
1152 
1153 	trace_musb_req_free(request);
1154 	kfree(request);
1155 }
1156 
1157 static LIST_HEAD(buffers);
1158 
1159 struct free_record {
1160 	struct list_head	list;
1161 	struct device		*dev;
1162 	unsigned		bytes;
1163 	dma_addr_t		dma;
1164 };
1165 
1166 /*
1167  * Context: controller locked, IRQs blocked.
1168  */
1169 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1170 {
1171 	trace_musb_req_start(req);
1172 	musb_ep_select(musb->mregs, req->epnum);
1173 	if (req->tx)
1174 		txstate(musb, req);
1175 	else
1176 		rxstate(musb, req);
1177 }
1178 
1179 static int musb_ep_restart_resume_work(struct musb *musb, void *data)
1180 {
1181 	struct musb_request *req = data;
1182 
1183 	musb_ep_restart(musb, req);
1184 
1185 	return 0;
1186 }
1187 
1188 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1189 			gfp_t gfp_flags)
1190 {
1191 	struct musb_ep		*musb_ep;
1192 	struct musb_request	*request;
1193 	struct musb		*musb;
1194 	int			status;
1195 	unsigned long		lockflags;
1196 
1197 	if (!ep || !req)
1198 		return -EINVAL;
1199 	if (!req->buf)
1200 		return -ENODATA;
1201 
1202 	musb_ep = to_musb_ep(ep);
1203 	musb = musb_ep->musb;
1204 
1205 	request = to_musb_request(req);
1206 	request->musb = musb;
1207 
1208 	if (request->ep != musb_ep)
1209 		return -EINVAL;
1210 
1211 	status = pm_runtime_get(musb->controller);
1212 	if ((status != -EINPROGRESS) && status < 0) {
1213 		dev_err(musb->controller,
1214 			"pm runtime get failed in %s\n",
1215 			__func__);
1216 		pm_runtime_put_noidle(musb->controller);
1217 
1218 		return status;
1219 	}
1220 	status = 0;
1221 
1222 	trace_musb_req_enq(request);
1223 
1224 	/* request is mine now... */
1225 	request->request.actual = 0;
1226 	request->request.status = -EINPROGRESS;
1227 	request->epnum = musb_ep->current_epnum;
1228 	request->tx = musb_ep->is_in;
1229 
1230 	map_dma_buffer(request, musb, musb_ep);
1231 
1232 	spin_lock_irqsave(&musb->lock, lockflags);
1233 
1234 	/* don't queue if the ep is down */
1235 	if (!musb_ep->desc) {
1236 		musb_dbg(musb, "req %p queued to %s while ep %s",
1237 				req, ep->name, "disabled");
1238 		status = -ESHUTDOWN;
1239 		unmap_dma_buffer(request, musb);
1240 		goto unlock;
1241 	}
1242 
1243 	/* add request to the list */
1244 	list_add_tail(&request->list, &musb_ep->req_list);
1245 
1246 	/* it this is the head of the queue, start i/o ... */
1247 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next) {
1248 		status = musb_queue_resume_work(musb,
1249 						musb_ep_restart_resume_work,
1250 						request);
1251 		if (status < 0)
1252 			dev_err(musb->controller, "%s resume work: %i\n",
1253 				__func__, status);
1254 	}
1255 
1256 unlock:
1257 	spin_unlock_irqrestore(&musb->lock, lockflags);
1258 	pm_runtime_mark_last_busy(musb->controller);
1259 	pm_runtime_put_autosuspend(musb->controller);
1260 
1261 	return status;
1262 }
1263 
1264 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1265 {
1266 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1267 	struct musb_request	*req = to_musb_request(request);
1268 	struct musb_request	*r;
1269 	unsigned long		flags;
1270 	int			status = 0;
1271 	struct musb		*musb = musb_ep->musb;
1272 
1273 	if (!ep || !request || req->ep != musb_ep)
1274 		return -EINVAL;
1275 
1276 	trace_musb_req_deq(req);
1277 
1278 	spin_lock_irqsave(&musb->lock, flags);
1279 
1280 	list_for_each_entry(r, &musb_ep->req_list, list) {
1281 		if (r == req)
1282 			break;
1283 	}
1284 	if (r != req) {
1285 		dev_err(musb->controller, "request %p not queued to %s\n",
1286 				request, ep->name);
1287 		status = -EINVAL;
1288 		goto done;
1289 	}
1290 
1291 	/* if the hardware doesn't have the request, easy ... */
1292 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1293 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1294 
1295 	/* ... else abort the dma transfer ... */
1296 	else if (is_dma_capable() && musb_ep->dma) {
1297 		struct dma_controller	*c = musb->dma_controller;
1298 
1299 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1300 		if (c->channel_abort)
1301 			status = c->channel_abort(musb_ep->dma);
1302 		else
1303 			status = -EBUSY;
1304 		if (status == 0)
1305 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1306 	} else {
1307 		/* NOTE: by sticking to easily tested hardware/driver states,
1308 		 * we leave counting of in-flight packets imprecise.
1309 		 */
1310 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1311 	}
1312 
1313 done:
1314 	spin_unlock_irqrestore(&musb->lock, flags);
1315 	return status;
1316 }
1317 
1318 /*
1319  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1320  * data but will queue requests.
1321  *
1322  * exported to ep0 code
1323  */
1324 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1325 {
1326 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1327 	u8			epnum = musb_ep->current_epnum;
1328 	struct musb		*musb = musb_ep->musb;
1329 	void __iomem		*epio = musb->endpoints[epnum].regs;
1330 	void __iomem		*mbase;
1331 	unsigned long		flags;
1332 	u16			csr;
1333 	struct musb_request	*request;
1334 	int			status = 0;
1335 
1336 	if (!ep)
1337 		return -EINVAL;
1338 	mbase = musb->mregs;
1339 
1340 	spin_lock_irqsave(&musb->lock, flags);
1341 
1342 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1343 		status = -EINVAL;
1344 		goto done;
1345 	}
1346 
1347 	musb_ep_select(mbase, epnum);
1348 
1349 	request = next_request(musb_ep);
1350 	if (value) {
1351 		if (request) {
1352 			musb_dbg(musb, "request in progress, cannot halt %s",
1353 			    ep->name);
1354 			status = -EAGAIN;
1355 			goto done;
1356 		}
1357 		/* Cannot portably stall with non-empty FIFO */
1358 		if (musb_ep->is_in) {
1359 			csr = musb_readw(epio, MUSB_TXCSR);
1360 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1361 				musb_dbg(musb, "FIFO busy, cannot halt %s",
1362 						ep->name);
1363 				status = -EAGAIN;
1364 				goto done;
1365 			}
1366 		}
1367 	} else
1368 		musb_ep->wedged = 0;
1369 
1370 	/* set/clear the stall and toggle bits */
1371 	musb_dbg(musb, "%s: %s stall", ep->name, value ? "set" : "clear");
1372 	if (musb_ep->is_in) {
1373 		csr = musb_readw(epio, MUSB_TXCSR);
1374 		csr |= MUSB_TXCSR_P_WZC_BITS
1375 			| MUSB_TXCSR_CLRDATATOG;
1376 		if (value)
1377 			csr |= MUSB_TXCSR_P_SENDSTALL;
1378 		else
1379 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1380 				| MUSB_TXCSR_P_SENTSTALL);
1381 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1382 		musb_writew(epio, MUSB_TXCSR, csr);
1383 	} else {
1384 		csr = musb_readw(epio, MUSB_RXCSR);
1385 		csr |= MUSB_RXCSR_P_WZC_BITS
1386 			| MUSB_RXCSR_FLUSHFIFO
1387 			| MUSB_RXCSR_CLRDATATOG;
1388 		if (value)
1389 			csr |= MUSB_RXCSR_P_SENDSTALL;
1390 		else
1391 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1392 				| MUSB_RXCSR_P_SENTSTALL);
1393 		musb_writew(epio, MUSB_RXCSR, csr);
1394 	}
1395 
1396 	/* maybe start the first request in the queue */
1397 	if (!musb_ep->busy && !value && request) {
1398 		musb_dbg(musb, "restarting the request");
1399 		musb_ep_restart(musb, request);
1400 	}
1401 
1402 done:
1403 	spin_unlock_irqrestore(&musb->lock, flags);
1404 	return status;
1405 }
1406 
1407 /*
1408  * Sets the halt feature with the clear requests ignored
1409  */
1410 static int musb_gadget_set_wedge(struct usb_ep *ep)
1411 {
1412 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1413 
1414 	if (!ep)
1415 		return -EINVAL;
1416 
1417 	musb_ep->wedged = 1;
1418 
1419 	return usb_ep_set_halt(ep);
1420 }
1421 
1422 static int musb_gadget_fifo_status(struct usb_ep *ep)
1423 {
1424 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1425 	void __iomem		*epio = musb_ep->hw_ep->regs;
1426 	int			retval = -EINVAL;
1427 
1428 	if (musb_ep->desc && !musb_ep->is_in) {
1429 		struct musb		*musb = musb_ep->musb;
1430 		int			epnum = musb_ep->current_epnum;
1431 		void __iomem		*mbase = musb->mregs;
1432 		unsigned long		flags;
1433 
1434 		spin_lock_irqsave(&musb->lock, flags);
1435 
1436 		musb_ep_select(mbase, epnum);
1437 		/* FIXME return zero unless RXPKTRDY is set */
1438 		retval = musb_readw(epio, MUSB_RXCOUNT);
1439 
1440 		spin_unlock_irqrestore(&musb->lock, flags);
1441 	}
1442 	return retval;
1443 }
1444 
1445 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1446 {
1447 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1448 	struct musb	*musb = musb_ep->musb;
1449 	u8		epnum = musb_ep->current_epnum;
1450 	void __iomem	*epio = musb->endpoints[epnum].regs;
1451 	void __iomem	*mbase;
1452 	unsigned long	flags;
1453 	u16		csr;
1454 
1455 	mbase = musb->mregs;
1456 
1457 	spin_lock_irqsave(&musb->lock, flags);
1458 	musb_ep_select(mbase, (u8) epnum);
1459 
1460 	/* disable interrupts */
1461 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe & ~(1 << epnum));
1462 
1463 	if (musb_ep->is_in) {
1464 		csr = musb_readw(epio, MUSB_TXCSR);
1465 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1466 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1467 			/*
1468 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1469 			 * to interrupt current FIFO loading, but not flushing
1470 			 * the already loaded ones.
1471 			 */
1472 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1473 			musb_writew(epio, MUSB_TXCSR, csr);
1474 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1475 			musb_writew(epio, MUSB_TXCSR, csr);
1476 		}
1477 	} else {
1478 		csr = musb_readw(epio, MUSB_RXCSR);
1479 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1480 		musb_writew(epio, MUSB_RXCSR, csr);
1481 		musb_writew(epio, MUSB_RXCSR, csr);
1482 	}
1483 
1484 	/* re-enable interrupt */
1485 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
1486 	spin_unlock_irqrestore(&musb->lock, flags);
1487 }
1488 
1489 static const struct usb_ep_ops musb_ep_ops = {
1490 	.enable		= musb_gadget_enable,
1491 	.disable	= musb_gadget_disable,
1492 	.alloc_request	= musb_alloc_request,
1493 	.free_request	= musb_free_request,
1494 	.queue		= musb_gadget_queue,
1495 	.dequeue	= musb_gadget_dequeue,
1496 	.set_halt	= musb_gadget_set_halt,
1497 	.set_wedge	= musb_gadget_set_wedge,
1498 	.fifo_status	= musb_gadget_fifo_status,
1499 	.fifo_flush	= musb_gadget_fifo_flush
1500 };
1501 
1502 /* ----------------------------------------------------------------------- */
1503 
1504 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1505 {
1506 	struct musb	*musb = gadget_to_musb(gadget);
1507 
1508 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1509 }
1510 
1511 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1512 {
1513 	struct musb	*musb = gadget_to_musb(gadget);
1514 	void __iomem	*mregs = musb->mregs;
1515 	unsigned long	flags;
1516 	int		status = -EINVAL;
1517 	u8		power, devctl;
1518 	int		retries;
1519 
1520 	spin_lock_irqsave(&musb->lock, flags);
1521 
1522 	switch (musb->xceiv->otg->state) {
1523 	case OTG_STATE_B_PERIPHERAL:
1524 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1525 		 * that's part of the standard usb 1.1 state machine, and
1526 		 * doesn't affect OTG transitions.
1527 		 */
1528 		if (musb->may_wakeup && musb->is_suspended)
1529 			break;
1530 		goto done;
1531 	case OTG_STATE_B_IDLE:
1532 		/* Start SRP ... OTG not required. */
1533 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1534 		musb_dbg(musb, "Sending SRP: devctl: %02x", devctl);
1535 		devctl |= MUSB_DEVCTL_SESSION;
1536 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1537 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1538 		retries = 100;
1539 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1540 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1541 			if (retries-- < 1)
1542 				break;
1543 		}
1544 		retries = 10000;
1545 		while (devctl & MUSB_DEVCTL_SESSION) {
1546 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1547 			if (retries-- < 1)
1548 				break;
1549 		}
1550 
1551 		spin_unlock_irqrestore(&musb->lock, flags);
1552 		otg_start_srp(musb->xceiv->otg);
1553 		spin_lock_irqsave(&musb->lock, flags);
1554 
1555 		/* Block idling for at least 1s */
1556 		musb_platform_try_idle(musb,
1557 			jiffies + msecs_to_jiffies(1 * HZ));
1558 
1559 		status = 0;
1560 		goto done;
1561 	default:
1562 		musb_dbg(musb, "Unhandled wake: %s",
1563 			usb_otg_state_string(musb->xceiv->otg->state));
1564 		goto done;
1565 	}
1566 
1567 	status = 0;
1568 
1569 	power = musb_readb(mregs, MUSB_POWER);
1570 	power |= MUSB_POWER_RESUME;
1571 	musb_writeb(mregs, MUSB_POWER, power);
1572 	musb_dbg(musb, "issue wakeup");
1573 
1574 	/* FIXME do this next chunk in a timer callback, no udelay */
1575 	mdelay(2);
1576 
1577 	power = musb_readb(mregs, MUSB_POWER);
1578 	power &= ~MUSB_POWER_RESUME;
1579 	musb_writeb(mregs, MUSB_POWER, power);
1580 done:
1581 	spin_unlock_irqrestore(&musb->lock, flags);
1582 	return status;
1583 }
1584 
1585 static int
1586 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1587 {
1588 	gadget->is_selfpowered = !!is_selfpowered;
1589 	return 0;
1590 }
1591 
1592 static void musb_pullup(struct musb *musb, int is_on)
1593 {
1594 	u8 power;
1595 
1596 	power = musb_readb(musb->mregs, MUSB_POWER);
1597 	if (is_on)
1598 		power |= MUSB_POWER_SOFTCONN;
1599 	else
1600 		power &= ~MUSB_POWER_SOFTCONN;
1601 
1602 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1603 
1604 	musb_dbg(musb, "gadget D+ pullup %s",
1605 		is_on ? "on" : "off");
1606 	musb_writeb(musb->mregs, MUSB_POWER, power);
1607 }
1608 
1609 #if 0
1610 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1611 {
1612 	musb_dbg(musb, "<= %s =>\n", __func__);
1613 
1614 	/*
1615 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1616 	 * though that can clear it), just musb_pullup().
1617 	 */
1618 
1619 	return -EINVAL;
1620 }
1621 #endif
1622 
1623 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1624 {
1625 	struct musb	*musb = gadget_to_musb(gadget);
1626 
1627 	if (!musb->xceiv->set_power)
1628 		return -EOPNOTSUPP;
1629 	return usb_phy_set_power(musb->xceiv, mA);
1630 }
1631 
1632 static void musb_gadget_work(struct work_struct *work)
1633 {
1634 	struct musb *musb;
1635 	unsigned long flags;
1636 
1637 	musb = container_of(work, struct musb, gadget_work.work);
1638 	pm_runtime_get_sync(musb->controller);
1639 	spin_lock_irqsave(&musb->lock, flags);
1640 	musb_pullup(musb, musb->softconnect);
1641 	spin_unlock_irqrestore(&musb->lock, flags);
1642 	pm_runtime_mark_last_busy(musb->controller);
1643 	pm_runtime_put_autosuspend(musb->controller);
1644 }
1645 
1646 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1647 {
1648 	struct musb	*musb = gadget_to_musb(gadget);
1649 	unsigned long	flags;
1650 
1651 	is_on = !!is_on;
1652 
1653 	/* NOTE: this assumes we are sensing vbus; we'd rather
1654 	 * not pullup unless the B-session is active.
1655 	 */
1656 	spin_lock_irqsave(&musb->lock, flags);
1657 	if (is_on != musb->softconnect) {
1658 		musb->softconnect = is_on;
1659 		schedule_delayed_work(&musb->gadget_work, 0);
1660 	}
1661 	spin_unlock_irqrestore(&musb->lock, flags);
1662 
1663 	return 0;
1664 }
1665 
1666 static int musb_gadget_start(struct usb_gadget *g,
1667 		struct usb_gadget_driver *driver);
1668 static int musb_gadget_stop(struct usb_gadget *g);
1669 
1670 static const struct usb_gadget_ops musb_gadget_operations = {
1671 	.get_frame		= musb_gadget_get_frame,
1672 	.wakeup			= musb_gadget_wakeup,
1673 	.set_selfpowered	= musb_gadget_set_self_powered,
1674 	/* .vbus_session		= musb_gadget_vbus_session, */
1675 	.vbus_draw		= musb_gadget_vbus_draw,
1676 	.pullup			= musb_gadget_pullup,
1677 	.udc_start		= musb_gadget_start,
1678 	.udc_stop		= musb_gadget_stop,
1679 };
1680 
1681 /* ----------------------------------------------------------------------- */
1682 
1683 /* Registration */
1684 
1685 /* Only this registration code "knows" the rule (from USB standards)
1686  * about there being only one external upstream port.  It assumes
1687  * all peripheral ports are external...
1688  */
1689 
1690 static void
1691 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1692 {
1693 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1694 
1695 	memset(ep, 0, sizeof *ep);
1696 
1697 	ep->current_epnum = epnum;
1698 	ep->musb = musb;
1699 	ep->hw_ep = hw_ep;
1700 	ep->is_in = is_in;
1701 
1702 	INIT_LIST_HEAD(&ep->req_list);
1703 
1704 	sprintf(ep->name, "ep%d%s", epnum,
1705 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1706 				is_in ? "in" : "out"));
1707 	ep->end_point.name = ep->name;
1708 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1709 	if (!epnum) {
1710 		usb_ep_set_maxpacket_limit(&ep->end_point, 64);
1711 		ep->end_point.caps.type_control = true;
1712 		ep->end_point.ops = &musb_g_ep0_ops;
1713 		musb->g.ep0 = &ep->end_point;
1714 	} else {
1715 		if (is_in)
1716 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_tx);
1717 		else
1718 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_rx);
1719 		ep->end_point.caps.type_iso = true;
1720 		ep->end_point.caps.type_bulk = true;
1721 		ep->end_point.caps.type_int = true;
1722 		ep->end_point.ops = &musb_ep_ops;
1723 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1724 	}
1725 
1726 	if (!epnum || hw_ep->is_shared_fifo) {
1727 		ep->end_point.caps.dir_in = true;
1728 		ep->end_point.caps.dir_out = true;
1729 	} else if (is_in)
1730 		ep->end_point.caps.dir_in = true;
1731 	else
1732 		ep->end_point.caps.dir_out = true;
1733 }
1734 
1735 /*
1736  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1737  * to the rest of the driver state.
1738  */
1739 static inline void musb_g_init_endpoints(struct musb *musb)
1740 {
1741 	u8			epnum;
1742 	struct musb_hw_ep	*hw_ep;
1743 	unsigned		count = 0;
1744 
1745 	/* initialize endpoint list just once */
1746 	INIT_LIST_HEAD(&(musb->g.ep_list));
1747 
1748 	for (epnum = 0, hw_ep = musb->endpoints;
1749 			epnum < musb->nr_endpoints;
1750 			epnum++, hw_ep++) {
1751 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1752 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1753 			count++;
1754 		} else {
1755 			if (hw_ep->max_packet_sz_tx) {
1756 				init_peripheral_ep(musb, &hw_ep->ep_in,
1757 							epnum, 1);
1758 				count++;
1759 			}
1760 			if (hw_ep->max_packet_sz_rx) {
1761 				init_peripheral_ep(musb, &hw_ep->ep_out,
1762 							epnum, 0);
1763 				count++;
1764 			}
1765 		}
1766 	}
1767 }
1768 
1769 /* called once during driver setup to initialize and link into
1770  * the driver model; memory is zeroed.
1771  */
1772 int musb_gadget_setup(struct musb *musb)
1773 {
1774 	int status;
1775 
1776 	/* REVISIT minor race:  if (erroneously) setting up two
1777 	 * musb peripherals at the same time, only the bus lock
1778 	 * is probably held.
1779 	 */
1780 
1781 	musb->g.ops = &musb_gadget_operations;
1782 	musb->g.max_speed = USB_SPEED_HIGH;
1783 	musb->g.speed = USB_SPEED_UNKNOWN;
1784 
1785 	MUSB_DEV_MODE(musb);
1786 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1787 
1788 	/* this "gadget" abstracts/virtualizes the controller */
1789 	musb->g.name = musb_driver_name;
1790 	/* don't support otg protocols */
1791 	musb->g.is_otg = 0;
1792 	INIT_DELAYED_WORK(&musb->gadget_work, musb_gadget_work);
1793 	musb_g_init_endpoints(musb);
1794 
1795 	musb->is_active = 0;
1796 	musb_platform_try_idle(musb, 0);
1797 
1798 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1799 	if (status)
1800 		goto err;
1801 
1802 	return 0;
1803 err:
1804 	musb->g.dev.parent = NULL;
1805 	device_unregister(&musb->g.dev);
1806 	return status;
1807 }
1808 
1809 void musb_gadget_cleanup(struct musb *musb)
1810 {
1811 	if (musb->port_mode == MUSB_HOST)
1812 		return;
1813 
1814 	cancel_delayed_work_sync(&musb->gadget_work);
1815 	usb_del_gadget_udc(&musb->g);
1816 }
1817 
1818 /*
1819  * Register the gadget driver. Used by gadget drivers when
1820  * registering themselves with the controller.
1821  *
1822  * -EINVAL something went wrong (not driver)
1823  * -EBUSY another gadget is already using the controller
1824  * -ENOMEM no memory to perform the operation
1825  *
1826  * @param driver the gadget driver
1827  * @return <0 if error, 0 if everything is fine
1828  */
1829 static int musb_gadget_start(struct usb_gadget *g,
1830 		struct usb_gadget_driver *driver)
1831 {
1832 	struct musb		*musb = gadget_to_musb(g);
1833 	struct usb_otg		*otg = musb->xceiv->otg;
1834 	unsigned long		flags;
1835 	int			retval = 0;
1836 
1837 	if (driver->max_speed < USB_SPEED_HIGH) {
1838 		retval = -EINVAL;
1839 		goto err;
1840 	}
1841 
1842 	pm_runtime_get_sync(musb->controller);
1843 
1844 	musb->softconnect = 0;
1845 	musb->gadget_driver = driver;
1846 
1847 	spin_lock_irqsave(&musb->lock, flags);
1848 	musb->is_active = 1;
1849 
1850 	otg_set_peripheral(otg, &musb->g);
1851 	musb->xceiv->otg->state = OTG_STATE_B_IDLE;
1852 	spin_unlock_irqrestore(&musb->lock, flags);
1853 
1854 	musb_start(musb);
1855 
1856 	/* REVISIT:  funcall to other code, which also
1857 	 * handles power budgeting ... this way also
1858 	 * ensures HdrcStart is indirectly called.
1859 	 */
1860 	if (musb->xceiv->last_event == USB_EVENT_ID)
1861 		musb_platform_set_vbus(musb, 1);
1862 
1863 	pm_runtime_mark_last_busy(musb->controller);
1864 	pm_runtime_put_autosuspend(musb->controller);
1865 
1866 	return 0;
1867 
1868 err:
1869 	return retval;
1870 }
1871 
1872 /*
1873  * Unregister the gadget driver. Used by gadget drivers when
1874  * unregistering themselves from the controller.
1875  *
1876  * @param driver the gadget driver to unregister
1877  */
1878 static int musb_gadget_stop(struct usb_gadget *g)
1879 {
1880 	struct musb	*musb = gadget_to_musb(g);
1881 	unsigned long	flags;
1882 
1883 	pm_runtime_get_sync(musb->controller);
1884 
1885 	/*
1886 	 * REVISIT always use otg_set_peripheral() here too;
1887 	 * this needs to shut down the OTG engine.
1888 	 */
1889 
1890 	spin_lock_irqsave(&musb->lock, flags);
1891 
1892 	musb_hnp_stop(musb);
1893 
1894 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1895 
1896 	musb->xceiv->otg->state = OTG_STATE_UNDEFINED;
1897 	musb_stop(musb);
1898 	otg_set_peripheral(musb->xceiv->otg, NULL);
1899 
1900 	musb->is_active = 0;
1901 	musb->gadget_driver = NULL;
1902 	musb_platform_try_idle(musb, 0);
1903 	spin_unlock_irqrestore(&musb->lock, flags);
1904 
1905 	/*
1906 	 * FIXME we need to be able to register another
1907 	 * gadget driver here and have everything work;
1908 	 * that currently misbehaves.
1909 	 */
1910 
1911 	/* Force check of devctl register for PM runtime */
1912 	schedule_delayed_work(&musb->irq_work, 0);
1913 
1914 	pm_runtime_mark_last_busy(musb->controller);
1915 	pm_runtime_put_autosuspend(musb->controller);
1916 
1917 	return 0;
1918 }
1919 
1920 /* ----------------------------------------------------------------------- */
1921 
1922 /* lifecycle operations called through plat_uds.c */
1923 
1924 void musb_g_resume(struct musb *musb)
1925 {
1926 	musb->is_suspended = 0;
1927 	switch (musb->xceiv->otg->state) {
1928 	case OTG_STATE_B_IDLE:
1929 		break;
1930 	case OTG_STATE_B_WAIT_ACON:
1931 	case OTG_STATE_B_PERIPHERAL:
1932 		musb->is_active = 1;
1933 		if (musb->gadget_driver && musb->gadget_driver->resume) {
1934 			spin_unlock(&musb->lock);
1935 			musb->gadget_driver->resume(&musb->g);
1936 			spin_lock(&musb->lock);
1937 		}
1938 		break;
1939 	default:
1940 		WARNING("unhandled RESUME transition (%s)\n",
1941 				usb_otg_state_string(musb->xceiv->otg->state));
1942 	}
1943 }
1944 
1945 /* called when SOF packets stop for 3+ msec */
1946 void musb_g_suspend(struct musb *musb)
1947 {
1948 	u8	devctl;
1949 
1950 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
1951 	musb_dbg(musb, "musb_g_suspend: devctl %02x", devctl);
1952 
1953 	switch (musb->xceiv->otg->state) {
1954 	case OTG_STATE_B_IDLE:
1955 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
1956 			musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
1957 		break;
1958 	case OTG_STATE_B_PERIPHERAL:
1959 		musb->is_suspended = 1;
1960 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
1961 			spin_unlock(&musb->lock);
1962 			musb->gadget_driver->suspend(&musb->g);
1963 			spin_lock(&musb->lock);
1964 		}
1965 		break;
1966 	default:
1967 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
1968 		 * A_PERIPHERAL may need care too
1969 		 */
1970 		WARNING("unhandled SUSPEND transition (%s)",
1971 				usb_otg_state_string(musb->xceiv->otg->state));
1972 	}
1973 }
1974 
1975 /* Called during SRP */
1976 void musb_g_wakeup(struct musb *musb)
1977 {
1978 	musb_gadget_wakeup(&musb->g);
1979 }
1980 
1981 /* called when VBUS drops below session threshold, and in other cases */
1982 void musb_g_disconnect(struct musb *musb)
1983 {
1984 	void __iomem	*mregs = musb->mregs;
1985 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
1986 
1987 	musb_dbg(musb, "musb_g_disconnect: devctl %02x", devctl);
1988 
1989 	/* clear HR */
1990 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
1991 
1992 	/* don't draw vbus until new b-default session */
1993 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1994 
1995 	musb->g.speed = USB_SPEED_UNKNOWN;
1996 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
1997 		spin_unlock(&musb->lock);
1998 		musb->gadget_driver->disconnect(&musb->g);
1999 		spin_lock(&musb->lock);
2000 	}
2001 
2002 	switch (musb->xceiv->otg->state) {
2003 	default:
2004 		musb_dbg(musb, "Unhandled disconnect %s, setting a_idle",
2005 			usb_otg_state_string(musb->xceiv->otg->state));
2006 		musb->xceiv->otg->state = OTG_STATE_A_IDLE;
2007 		MUSB_HST_MODE(musb);
2008 		break;
2009 	case OTG_STATE_A_PERIPHERAL:
2010 		musb->xceiv->otg->state = OTG_STATE_A_WAIT_BCON;
2011 		MUSB_HST_MODE(musb);
2012 		break;
2013 	case OTG_STATE_B_WAIT_ACON:
2014 	case OTG_STATE_B_HOST:
2015 	case OTG_STATE_B_PERIPHERAL:
2016 	case OTG_STATE_B_IDLE:
2017 		musb->xceiv->otg->state = OTG_STATE_B_IDLE;
2018 		break;
2019 	case OTG_STATE_B_SRP_INIT:
2020 		break;
2021 	}
2022 
2023 	musb->is_active = 0;
2024 }
2025 
2026 void musb_g_reset(struct musb *musb)
2027 __releases(musb->lock)
2028 __acquires(musb->lock)
2029 {
2030 	void __iomem	*mbase = musb->mregs;
2031 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2032 	u8		power;
2033 
2034 	musb_dbg(musb, "<== %s driver '%s'",
2035 			(devctl & MUSB_DEVCTL_BDEVICE)
2036 				? "B-Device" : "A-Device",
2037 			musb->gadget_driver
2038 				? musb->gadget_driver->driver.name
2039 				: NULL
2040 			);
2041 
2042 	/* report reset, if we didn't already (flushing EP state) */
2043 	if (musb->gadget_driver && musb->g.speed != USB_SPEED_UNKNOWN) {
2044 		spin_unlock(&musb->lock);
2045 		usb_gadget_udc_reset(&musb->g, musb->gadget_driver);
2046 		spin_lock(&musb->lock);
2047 	}
2048 
2049 	/* clear HR */
2050 	else if (devctl & MUSB_DEVCTL_HR)
2051 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2052 
2053 
2054 	/* what speed did we negotiate? */
2055 	power = musb_readb(mbase, MUSB_POWER);
2056 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2057 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2058 
2059 	/* start in USB_STATE_DEFAULT */
2060 	musb->is_active = 1;
2061 	musb->is_suspended = 0;
2062 	MUSB_DEV_MODE(musb);
2063 	musb->address = 0;
2064 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2065 
2066 	musb->may_wakeup = 0;
2067 	musb->g.b_hnp_enable = 0;
2068 	musb->g.a_alt_hnp_support = 0;
2069 	musb->g.a_hnp_support = 0;
2070 	musb->g.quirk_zlp_not_supp = 1;
2071 
2072 	/* Normal reset, as B-Device;
2073 	 * or else after HNP, as A-Device
2074 	 */
2075 	if (!musb->g.is_otg) {
2076 		/* USB device controllers that are not OTG compatible
2077 		 * may not have DEVCTL register in silicon.
2078 		 * In that case, do not rely on devctl for setting
2079 		 * peripheral mode.
2080 		 */
2081 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2082 		musb->g.is_a_peripheral = 0;
2083 	} else if (devctl & MUSB_DEVCTL_BDEVICE) {
2084 		musb->xceiv->otg->state = OTG_STATE_B_PERIPHERAL;
2085 		musb->g.is_a_peripheral = 0;
2086 	} else {
2087 		musb->xceiv->otg->state = OTG_STATE_A_PERIPHERAL;
2088 		musb->g.is_a_peripheral = 1;
2089 	}
2090 
2091 	/* start with default limits on VBUS power draw */
2092 	(void) musb_gadget_vbus_draw(&musb->g, 8);
2093 }
2094