xref: /linux/drivers/usb/musb/musb_gadget.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  * MUSB OTG driver peripheral support
3  *
4  * Copyright 2005 Mentor Graphics Corporation
5  * Copyright (C) 2005-2006 by Texas Instruments
6  * Copyright (C) 2006-2007 Nokia Corporation
7  * Copyright (C) 2009 MontaVista Software, Inc. <source@mvista.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * version 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
21  * 02110-1301 USA
22  *
23  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
24  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
26  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
30  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  */
35 
36 #include <linux/kernel.h>
37 #include <linux/list.h>
38 #include <linux/timer.h>
39 #include <linux/module.h>
40 #include <linux/smp.h>
41 #include <linux/spinlock.h>
42 #include <linux/delay.h>
43 #include <linux/moduleparam.h>
44 #include <linux/stat.h>
45 #include <linux/dma-mapping.h>
46 #include <linux/slab.h>
47 
48 #include "musb_core.h"
49 
50 
51 /* MUSB PERIPHERAL status 3-mar-2006:
52  *
53  * - EP0 seems solid.  It passes both USBCV and usbtest control cases.
54  *   Minor glitches:
55  *
56  *     + remote wakeup to Linux hosts work, but saw USBCV failures;
57  *       in one test run (operator error?)
58  *     + endpoint halt tests -- in both usbtest and usbcv -- seem
59  *       to break when dma is enabled ... is something wrongly
60  *       clearing SENDSTALL?
61  *
62  * - Mass storage behaved ok when last tested.  Network traffic patterns
63  *   (with lots of short transfers etc) need retesting; they turn up the
64  *   worst cases of the DMA, since short packets are typical but are not
65  *   required.
66  *
67  * - TX/IN
68  *     + both pio and dma behave in with network and g_zero tests
69  *     + no cppi throughput issues other than no-hw-queueing
70  *     + failed with FLAT_REG (DaVinci)
71  *     + seems to behave with double buffering, PIO -and- CPPI
72  *     + with gadgetfs + AIO, requests got lost?
73  *
74  * - RX/OUT
75  *     + both pio and dma behave in with network and g_zero tests
76  *     + dma is slow in typical case (short_not_ok is clear)
77  *     + double buffering ok with PIO
78  *     + double buffering *FAILS* with CPPI, wrong data bytes sometimes
79  *     + request lossage observed with gadgetfs
80  *
81  * - ISO not tested ... might work, but only weakly isochronous
82  *
83  * - Gadget driver disabling of softconnect during bind() is ignored; so
84  *   drivers can't hold off host requests until userspace is ready.
85  *   (Workaround:  they can turn it off later.)
86  *
87  * - PORTABILITY (assumes PIO works):
88  *     + DaVinci, basically works with cppi dma
89  *     + OMAP 2430, ditto with mentor dma
90  *     + TUSB 6010, platform-specific dma in the works
91  */
92 
93 /* ----------------------------------------------------------------------- */
94 
95 #define is_buffer_mapped(req) (is_dma_capable() && \
96 					(req->map_state != UN_MAPPED))
97 
98 /* Maps the buffer to dma  */
99 
100 static inline void map_dma_buffer(struct musb_request *request,
101 			struct musb *musb, struct musb_ep *musb_ep)
102 {
103 	int compatible = true;
104 	struct dma_controller *dma = musb->dma_controller;
105 
106 	request->map_state = UN_MAPPED;
107 
108 	if (!is_dma_capable() || !musb_ep->dma)
109 		return;
110 
111 	/* Check if DMA engine can handle this request.
112 	 * DMA code must reject the USB request explicitly.
113 	 * Default behaviour is to map the request.
114 	 */
115 	if (dma->is_compatible)
116 		compatible = dma->is_compatible(musb_ep->dma,
117 				musb_ep->packet_sz, request->request.buf,
118 				request->request.length);
119 	if (!compatible)
120 		return;
121 
122 	if (request->request.dma == DMA_ADDR_INVALID) {
123 		request->request.dma = dma_map_single(
124 				musb->controller,
125 				request->request.buf,
126 				request->request.length,
127 				request->tx
128 					? DMA_TO_DEVICE
129 					: DMA_FROM_DEVICE);
130 		request->map_state = MUSB_MAPPED;
131 	} else {
132 		dma_sync_single_for_device(musb->controller,
133 			request->request.dma,
134 			request->request.length,
135 			request->tx
136 				? DMA_TO_DEVICE
137 				: DMA_FROM_DEVICE);
138 		request->map_state = PRE_MAPPED;
139 	}
140 }
141 
142 /* Unmap the buffer from dma and maps it back to cpu */
143 static inline void unmap_dma_buffer(struct musb_request *request,
144 				struct musb *musb)
145 {
146 	if (!is_buffer_mapped(request))
147 		return;
148 
149 	if (request->request.dma == DMA_ADDR_INVALID) {
150 		dev_vdbg(musb->controller,
151 				"not unmapping a never mapped buffer\n");
152 		return;
153 	}
154 	if (request->map_state == MUSB_MAPPED) {
155 		dma_unmap_single(musb->controller,
156 			request->request.dma,
157 			request->request.length,
158 			request->tx
159 				? DMA_TO_DEVICE
160 				: DMA_FROM_DEVICE);
161 		request->request.dma = DMA_ADDR_INVALID;
162 	} else { /* PRE_MAPPED */
163 		dma_sync_single_for_cpu(musb->controller,
164 			request->request.dma,
165 			request->request.length,
166 			request->tx
167 				? DMA_TO_DEVICE
168 				: DMA_FROM_DEVICE);
169 	}
170 	request->map_state = UN_MAPPED;
171 }
172 
173 /*
174  * Immediately complete a request.
175  *
176  * @param request the request to complete
177  * @param status the status to complete the request with
178  * Context: controller locked, IRQs blocked.
179  */
180 void musb_g_giveback(
181 	struct musb_ep		*ep,
182 	struct usb_request	*request,
183 	int			status)
184 __releases(ep->musb->lock)
185 __acquires(ep->musb->lock)
186 {
187 	struct musb_request	*req;
188 	struct musb		*musb;
189 	int			busy = ep->busy;
190 
191 	req = to_musb_request(request);
192 
193 	list_del(&req->list);
194 	if (req->request.status == -EINPROGRESS)
195 		req->request.status = status;
196 	musb = req->musb;
197 
198 	ep->busy = 1;
199 	spin_unlock(&musb->lock);
200 	unmap_dma_buffer(req, musb);
201 	if (request->status == 0)
202 		dev_dbg(musb->controller, "%s done request %p,  %d/%d\n",
203 				ep->end_point.name, request,
204 				req->request.actual, req->request.length);
205 	else
206 		dev_dbg(musb->controller, "%s request %p, %d/%d fault %d\n",
207 				ep->end_point.name, request,
208 				req->request.actual, req->request.length,
209 				request->status);
210 	req->request.complete(&req->ep->end_point, &req->request);
211 	spin_lock(&musb->lock);
212 	ep->busy = busy;
213 }
214 
215 /* ----------------------------------------------------------------------- */
216 
217 /*
218  * Abort requests queued to an endpoint using the status. Synchronous.
219  * caller locked controller and blocked irqs, and selected this ep.
220  */
221 static void nuke(struct musb_ep *ep, const int status)
222 {
223 	struct musb		*musb = ep->musb;
224 	struct musb_request	*req = NULL;
225 	void __iomem *epio = ep->musb->endpoints[ep->current_epnum].regs;
226 
227 	ep->busy = 1;
228 
229 	if (is_dma_capable() && ep->dma) {
230 		struct dma_controller	*c = ep->musb->dma_controller;
231 		int value;
232 
233 		if (ep->is_in) {
234 			/*
235 			 * The programming guide says that we must not clear
236 			 * the DMAMODE bit before DMAENAB, so we only
237 			 * clear it in the second write...
238 			 */
239 			musb_writew(epio, MUSB_TXCSR,
240 				    MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
241 			musb_writew(epio, MUSB_TXCSR,
242 					0 | MUSB_TXCSR_FLUSHFIFO);
243 		} else {
244 			musb_writew(epio, MUSB_RXCSR,
245 					0 | MUSB_RXCSR_FLUSHFIFO);
246 			musb_writew(epio, MUSB_RXCSR,
247 					0 | MUSB_RXCSR_FLUSHFIFO);
248 		}
249 
250 		value = c->channel_abort(ep->dma);
251 		dev_dbg(musb->controller, "%s: abort DMA --> %d\n",
252 				ep->name, value);
253 		c->channel_release(ep->dma);
254 		ep->dma = NULL;
255 	}
256 
257 	while (!list_empty(&ep->req_list)) {
258 		req = list_first_entry(&ep->req_list, struct musb_request, list);
259 		musb_g_giveback(ep, &req->request, status);
260 	}
261 }
262 
263 /* ----------------------------------------------------------------------- */
264 
265 /* Data transfers - pure PIO, pure DMA, or mixed mode */
266 
267 /*
268  * This assumes the separate CPPI engine is responding to DMA requests
269  * from the usb core ... sequenced a bit differently from mentor dma.
270  */
271 
272 static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
273 {
274 	if (can_bulk_split(musb, ep->type))
275 		return ep->hw_ep->max_packet_sz_tx;
276 	else
277 		return ep->packet_sz;
278 }
279 
280 
281 #ifdef CONFIG_USB_INVENTRA_DMA
282 
283 /* Peripheral tx (IN) using Mentor DMA works as follows:
284 	Only mode 0 is used for transfers <= wPktSize,
285 	mode 1 is used for larger transfers,
286 
287 	One of the following happens:
288 	- Host sends IN token which causes an endpoint interrupt
289 		-> TxAvail
290 			-> if DMA is currently busy, exit.
291 			-> if queue is non-empty, txstate().
292 
293 	- Request is queued by the gadget driver.
294 		-> if queue was previously empty, txstate()
295 
296 	txstate()
297 		-> start
298 		  /\	-> setup DMA
299 		  |     (data is transferred to the FIFO, then sent out when
300 		  |	IN token(s) are recd from Host.
301 		  |		-> DMA interrupt on completion
302 		  |		   calls TxAvail.
303 		  |		      -> stop DMA, ~DMAENAB,
304 		  |		      -> set TxPktRdy for last short pkt or zlp
305 		  |		      -> Complete Request
306 		  |		      -> Continue next request (call txstate)
307 		  |___________________________________|
308 
309  * Non-Mentor DMA engines can of course work differently, such as by
310  * upleveling from irq-per-packet to irq-per-buffer.
311  */
312 
313 #endif
314 
315 /*
316  * An endpoint is transmitting data. This can be called either from
317  * the IRQ routine or from ep.queue() to kickstart a request on an
318  * endpoint.
319  *
320  * Context: controller locked, IRQs blocked, endpoint selected
321  */
322 static void txstate(struct musb *musb, struct musb_request *req)
323 {
324 	u8			epnum = req->epnum;
325 	struct musb_ep		*musb_ep;
326 	void __iomem		*epio = musb->endpoints[epnum].regs;
327 	struct usb_request	*request;
328 	u16			fifo_count = 0, csr;
329 	int			use_dma = 0;
330 
331 	musb_ep = req->ep;
332 
333 	/* we shouldn't get here while DMA is active ... but we do ... */
334 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
335 		dev_dbg(musb->controller, "dma pending...\n");
336 		return;
337 	}
338 
339 	/* read TXCSR before */
340 	csr = musb_readw(epio, MUSB_TXCSR);
341 
342 	request = &req->request;
343 	fifo_count = min(max_ep_writesize(musb, musb_ep),
344 			(int)(request->length - request->actual));
345 
346 	if (csr & MUSB_TXCSR_TXPKTRDY) {
347 		dev_dbg(musb->controller, "%s old packet still ready , txcsr %03x\n",
348 				musb_ep->end_point.name, csr);
349 		return;
350 	}
351 
352 	if (csr & MUSB_TXCSR_P_SENDSTALL) {
353 		dev_dbg(musb->controller, "%s stalling, txcsr %03x\n",
354 				musb_ep->end_point.name, csr);
355 		return;
356 	}
357 
358 	dev_dbg(musb->controller, "hw_ep%d, maxpacket %d, fifo count %d, txcsr %03x\n",
359 			epnum, musb_ep->packet_sz, fifo_count,
360 			csr);
361 
362 #ifndef	CONFIG_MUSB_PIO_ONLY
363 	if (is_buffer_mapped(req)) {
364 		struct dma_controller	*c = musb->dma_controller;
365 		size_t request_size;
366 
367 		/* setup DMA, then program endpoint CSR */
368 		request_size = min_t(size_t, request->length - request->actual,
369 					musb_ep->dma->max_len);
370 
371 		use_dma = (request->dma != DMA_ADDR_INVALID);
372 
373 		/* MUSB_TXCSR_P_ISO is still set correctly */
374 
375 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
376 		{
377 			if (request_size < musb_ep->packet_sz)
378 				musb_ep->dma->desired_mode = 0;
379 			else
380 				musb_ep->dma->desired_mode = 1;
381 
382 			use_dma = use_dma && c->channel_program(
383 					musb_ep->dma, musb_ep->packet_sz,
384 					musb_ep->dma->desired_mode,
385 					request->dma + request->actual, request_size);
386 			if (use_dma) {
387 				if (musb_ep->dma->desired_mode == 0) {
388 					/*
389 					 * We must not clear the DMAMODE bit
390 					 * before the DMAENAB bit -- and the
391 					 * latter doesn't always get cleared
392 					 * before we get here...
393 					 */
394 					csr &= ~(MUSB_TXCSR_AUTOSET
395 						| MUSB_TXCSR_DMAENAB);
396 					musb_writew(epio, MUSB_TXCSR, csr
397 						| MUSB_TXCSR_P_WZC_BITS);
398 					csr &= ~MUSB_TXCSR_DMAMODE;
399 					csr |= (MUSB_TXCSR_DMAENAB |
400 							MUSB_TXCSR_MODE);
401 					/* against programming guide */
402 				} else {
403 					csr |= (MUSB_TXCSR_DMAENAB
404 							| MUSB_TXCSR_DMAMODE
405 							| MUSB_TXCSR_MODE);
406 					if (!musb_ep->hb_mult)
407 						csr |= MUSB_TXCSR_AUTOSET;
408 				}
409 				csr &= ~MUSB_TXCSR_P_UNDERRUN;
410 
411 				musb_writew(epio, MUSB_TXCSR, csr);
412 			}
413 		}
414 
415 #elif defined(CONFIG_USB_TI_CPPI_DMA)
416 		/* program endpoint CSR first, then setup DMA */
417 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
418 		csr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_DMAMODE |
419 		       MUSB_TXCSR_MODE;
420 		musb_writew(epio, MUSB_TXCSR,
421 			(MUSB_TXCSR_P_WZC_BITS & ~MUSB_TXCSR_P_UNDERRUN)
422 				| csr);
423 
424 		/* ensure writebuffer is empty */
425 		csr = musb_readw(epio, MUSB_TXCSR);
426 
427 		/* NOTE host side sets DMAENAB later than this; both are
428 		 * OK since the transfer dma glue (between CPPI and Mentor
429 		 * fifos) just tells CPPI it could start.  Data only moves
430 		 * to the USB TX fifo when both fifos are ready.
431 		 */
432 
433 		/* "mode" is irrelevant here; handle terminating ZLPs like
434 		 * PIO does, since the hardware RNDIS mode seems unreliable
435 		 * except for the last-packet-is-already-short case.
436 		 */
437 		use_dma = use_dma && c->channel_program(
438 				musb_ep->dma, musb_ep->packet_sz,
439 				0,
440 				request->dma + request->actual,
441 				request_size);
442 		if (!use_dma) {
443 			c->channel_release(musb_ep->dma);
444 			musb_ep->dma = NULL;
445 			csr &= ~MUSB_TXCSR_DMAENAB;
446 			musb_writew(epio, MUSB_TXCSR, csr);
447 			/* invariant: prequest->buf is non-null */
448 		}
449 #elif defined(CONFIG_USB_TUSB_OMAP_DMA)
450 		use_dma = use_dma && c->channel_program(
451 				musb_ep->dma, musb_ep->packet_sz,
452 				request->zero,
453 				request->dma + request->actual,
454 				request_size);
455 #endif
456 	}
457 #endif
458 
459 	if (!use_dma) {
460 		/*
461 		 * Unmap the dma buffer back to cpu if dma channel
462 		 * programming fails
463 		 */
464 		unmap_dma_buffer(req, musb);
465 
466 		musb_write_fifo(musb_ep->hw_ep, fifo_count,
467 				(u8 *) (request->buf + request->actual));
468 		request->actual += fifo_count;
469 		csr |= MUSB_TXCSR_TXPKTRDY;
470 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
471 		musb_writew(epio, MUSB_TXCSR, csr);
472 	}
473 
474 	/* host may already have the data when this message shows... */
475 	dev_dbg(musb->controller, "%s TX/IN %s len %d/%d, txcsr %04x, fifo %d/%d\n",
476 			musb_ep->end_point.name, use_dma ? "dma" : "pio",
477 			request->actual, request->length,
478 			musb_readw(epio, MUSB_TXCSR),
479 			fifo_count,
480 			musb_readw(epio, MUSB_TXMAXP));
481 }
482 
483 /*
484  * FIFO state update (e.g. data ready).
485  * Called from IRQ,  with controller locked.
486  */
487 void musb_g_tx(struct musb *musb, u8 epnum)
488 {
489 	u16			csr;
490 	struct musb_request	*req;
491 	struct usb_request	*request;
492 	u8 __iomem		*mbase = musb->mregs;
493 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_in;
494 	void __iomem		*epio = musb->endpoints[epnum].regs;
495 	struct dma_channel	*dma;
496 
497 	musb_ep_select(mbase, epnum);
498 	req = next_request(musb_ep);
499 	request = &req->request;
500 
501 	csr = musb_readw(epio, MUSB_TXCSR);
502 	dev_dbg(musb->controller, "<== %s, txcsr %04x\n", musb_ep->end_point.name, csr);
503 
504 	dma = is_dma_capable() ? musb_ep->dma : NULL;
505 
506 	/*
507 	 * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX
508 	 * probably rates reporting as a host error.
509 	 */
510 	if (csr & MUSB_TXCSR_P_SENTSTALL) {
511 		csr |=	MUSB_TXCSR_P_WZC_BITS;
512 		csr &= ~MUSB_TXCSR_P_SENTSTALL;
513 		musb_writew(epio, MUSB_TXCSR, csr);
514 		return;
515 	}
516 
517 	if (csr & MUSB_TXCSR_P_UNDERRUN) {
518 		/* We NAKed, no big deal... little reason to care. */
519 		csr |=	 MUSB_TXCSR_P_WZC_BITS;
520 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
521 		musb_writew(epio, MUSB_TXCSR, csr);
522 		dev_vdbg(musb->controller, "underrun on ep%d, req %p\n",
523 				epnum, request);
524 	}
525 
526 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
527 		/*
528 		 * SHOULD NOT HAPPEN... has with CPPI though, after
529 		 * changing SENDSTALL (and other cases); harmless?
530 		 */
531 		dev_dbg(musb->controller, "%s dma still busy?\n", musb_ep->end_point.name);
532 		return;
533 	}
534 
535 	if (request) {
536 		u8	is_dma = 0;
537 
538 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
539 			is_dma = 1;
540 			csr |= MUSB_TXCSR_P_WZC_BITS;
541 			csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
542 				 MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET);
543 			musb_writew(epio, MUSB_TXCSR, csr);
544 			/* Ensure writebuffer is empty. */
545 			csr = musb_readw(epio, MUSB_TXCSR);
546 			request->actual += musb_ep->dma->actual_len;
547 			dev_dbg(musb->controller, "TXCSR%d %04x, DMA off, len %zu, req %p\n",
548 				epnum, csr, musb_ep->dma->actual_len, request);
549 		}
550 
551 		/*
552 		 * First, maybe a terminating short packet. Some DMA
553 		 * engines might handle this by themselves.
554 		 */
555 		if ((request->zero && request->length
556 			&& (request->length % musb_ep->packet_sz == 0)
557 			&& (request->actual == request->length))
558 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
559 			|| (is_dma && (!dma->desired_mode ||
560 				(request->actual &
561 					(musb_ep->packet_sz - 1))))
562 #endif
563 		) {
564 			/*
565 			 * On DMA completion, FIFO may not be
566 			 * available yet...
567 			 */
568 			if (csr & MUSB_TXCSR_TXPKTRDY)
569 				return;
570 
571 			dev_dbg(musb->controller, "sending zero pkt\n");
572 			musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
573 					| MUSB_TXCSR_TXPKTRDY);
574 			request->zero = 0;
575 		}
576 
577 		if (request->actual == request->length) {
578 			musb_g_giveback(musb_ep, request, 0);
579 			req = musb_ep->desc ? next_request(musb_ep) : NULL;
580 			if (!req) {
581 				dev_dbg(musb->controller, "%s idle now\n",
582 					musb_ep->end_point.name);
583 				return;
584 			}
585 		}
586 
587 		txstate(musb, req);
588 	}
589 }
590 
591 /* ------------------------------------------------------------ */
592 
593 #ifdef CONFIG_USB_INVENTRA_DMA
594 
595 /* Peripheral rx (OUT) using Mentor DMA works as follows:
596 	- Only mode 0 is used.
597 
598 	- Request is queued by the gadget class driver.
599 		-> if queue was previously empty, rxstate()
600 
601 	- Host sends OUT token which causes an endpoint interrupt
602 	  /\      -> RxReady
603 	  |	      -> if request queued, call rxstate
604 	  |		/\	-> setup DMA
605 	  |		|	     -> DMA interrupt on completion
606 	  |		|		-> RxReady
607 	  |		|		      -> stop DMA
608 	  |		|		      -> ack the read
609 	  |		|		      -> if data recd = max expected
610 	  |		|				by the request, or host
611 	  |		|				sent a short packet,
612 	  |		|				complete the request,
613 	  |		|				and start the next one.
614 	  |		|_____________________________________|
615 	  |					 else just wait for the host
616 	  |					    to send the next OUT token.
617 	  |__________________________________________________|
618 
619  * Non-Mentor DMA engines can of course work differently.
620  */
621 
622 #endif
623 
624 /*
625  * Context: controller locked, IRQs blocked, endpoint selected
626  */
627 static void rxstate(struct musb *musb, struct musb_request *req)
628 {
629 	const u8		epnum = req->epnum;
630 	struct usb_request	*request = &req->request;
631 	struct musb_ep		*musb_ep;
632 	void __iomem		*epio = musb->endpoints[epnum].regs;
633 	unsigned		fifo_count = 0;
634 	u16			len;
635 	u16			csr = musb_readw(epio, MUSB_RXCSR);
636 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
637 	u8			use_mode_1;
638 
639 	if (hw_ep->is_shared_fifo)
640 		musb_ep = &hw_ep->ep_in;
641 	else
642 		musb_ep = &hw_ep->ep_out;
643 
644 	len = musb_ep->packet_sz;
645 
646 	/* We shouldn't get here while DMA is active, but we do... */
647 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
648 		dev_dbg(musb->controller, "DMA pending...\n");
649 		return;
650 	}
651 
652 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
653 		dev_dbg(musb->controller, "%s stalling, RXCSR %04x\n",
654 		    musb_ep->end_point.name, csr);
655 		return;
656 	}
657 
658 	if (is_cppi_enabled() && is_buffer_mapped(req)) {
659 		struct dma_controller	*c = musb->dma_controller;
660 		struct dma_channel	*channel = musb_ep->dma;
661 
662 		/* NOTE:  CPPI won't actually stop advancing the DMA
663 		 * queue after short packet transfers, so this is almost
664 		 * always going to run as IRQ-per-packet DMA so that
665 		 * faults will be handled correctly.
666 		 */
667 		if (c->channel_program(channel,
668 				musb_ep->packet_sz,
669 				!request->short_not_ok,
670 				request->dma + request->actual,
671 				request->length - request->actual)) {
672 
673 			/* make sure that if an rxpkt arrived after the irq,
674 			 * the cppi engine will be ready to take it as soon
675 			 * as DMA is enabled
676 			 */
677 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
678 					| MUSB_RXCSR_DMAMODE);
679 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
680 			musb_writew(epio, MUSB_RXCSR, csr);
681 			return;
682 		}
683 	}
684 
685 	if (csr & MUSB_RXCSR_RXPKTRDY) {
686 		len = musb_readw(epio, MUSB_RXCOUNT);
687 
688 		/*
689 		 * Enable Mode 1 on RX transfers only when short_not_ok flag
690 		 * is set. Currently short_not_ok flag is set only from
691 		 * file_storage and f_mass_storage drivers
692 		 */
693 
694 		if (request->short_not_ok && len == musb_ep->packet_sz)
695 			use_mode_1 = 1;
696 		else
697 			use_mode_1 = 0;
698 
699 		if (request->actual < request->length) {
700 #ifdef CONFIG_USB_INVENTRA_DMA
701 			if (is_buffer_mapped(req)) {
702 				struct dma_controller	*c;
703 				struct dma_channel	*channel;
704 				int			use_dma = 0;
705 
706 				c = musb->dma_controller;
707 				channel = musb_ep->dma;
708 
709 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
710 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
711 	 * completion. We only get interrupts from DMA controller.
712 	 *
713 	 * We could operate in DMA mode 1 if we knew the size of the tranfer
714 	 * in advance. For mass storage class, request->length = what the host
715 	 * sends, so that'd work.  But for pretty much everything else,
716 	 * request->length is routinely more than what the host sends. For
717 	 * most these gadgets, end of is signified either by a short packet,
718 	 * or filling the last byte of the buffer.  (Sending extra data in
719 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
720 	 * we don't get DMA completion interrupt for short packets.
721 	 *
722 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
723 	 * to get endpoint interrupt on every DMA req, but that didn't seem
724 	 * to work reliably.
725 	 *
726 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
727 	 * then becomes usable as a runtime "use mode 1" hint...
728 	 */
729 
730 				/* Experimental: Mode1 works with mass storage use cases */
731 				if (use_mode_1) {
732 					csr |= MUSB_RXCSR_AUTOCLEAR;
733 					musb_writew(epio, MUSB_RXCSR, csr);
734 					csr |= MUSB_RXCSR_DMAENAB;
735 					musb_writew(epio, MUSB_RXCSR, csr);
736 
737 					/*
738 					 * this special sequence (enabling and then
739 					 * disabling MUSB_RXCSR_DMAMODE) is required
740 					 * to get DMAReq to activate
741 					 */
742 					musb_writew(epio, MUSB_RXCSR,
743 						csr | MUSB_RXCSR_DMAMODE);
744 					musb_writew(epio, MUSB_RXCSR, csr);
745 
746 				} else {
747 					if (!musb_ep->hb_mult &&
748 						musb_ep->hw_ep->rx_double_buffered)
749 						csr |= MUSB_RXCSR_AUTOCLEAR;
750 					csr |= MUSB_RXCSR_DMAENAB;
751 					musb_writew(epio, MUSB_RXCSR, csr);
752 				}
753 
754 				if (request->actual < request->length) {
755 					int transfer_size = 0;
756 					if (use_mode_1) {
757 						transfer_size = min(request->length - request->actual,
758 								channel->max_len);
759 						musb_ep->dma->desired_mode = 1;
760 					} else {
761 						transfer_size = min(request->length - request->actual,
762 								(unsigned)len);
763 						musb_ep->dma->desired_mode = 0;
764 					}
765 
766 					use_dma = c->channel_program(
767 							channel,
768 							musb_ep->packet_sz,
769 							channel->desired_mode,
770 							request->dma
771 							+ request->actual,
772 							transfer_size);
773 				}
774 
775 				if (use_dma)
776 					return;
777 			}
778 #elif defined(CONFIG_USB_UX500_DMA)
779 			if ((is_buffer_mapped(req)) &&
780 				(request->actual < request->length)) {
781 
782 				struct dma_controller *c;
783 				struct dma_channel *channel;
784 				int transfer_size = 0;
785 
786 				c = musb->dma_controller;
787 				channel = musb_ep->dma;
788 
789 				/* In case first packet is short */
790 				if (len < musb_ep->packet_sz)
791 					transfer_size = len;
792 				else if (request->short_not_ok)
793 					transfer_size =	min(request->length -
794 							request->actual,
795 							channel->max_len);
796 				else
797 					transfer_size = min(request->length -
798 							request->actual,
799 							(unsigned)len);
800 
801 				csr &= ~MUSB_RXCSR_DMAMODE;
802 				csr |= (MUSB_RXCSR_DMAENAB |
803 					MUSB_RXCSR_AUTOCLEAR);
804 
805 				musb_writew(epio, MUSB_RXCSR, csr);
806 
807 				if (transfer_size <= musb_ep->packet_sz) {
808 					musb_ep->dma->desired_mode = 0;
809 				} else {
810 					musb_ep->dma->desired_mode = 1;
811 					/* Mode must be set after DMAENAB */
812 					csr |= MUSB_RXCSR_DMAMODE;
813 					musb_writew(epio, MUSB_RXCSR, csr);
814 				}
815 
816 				if (c->channel_program(channel,
817 							musb_ep->packet_sz,
818 							channel->desired_mode,
819 							request->dma
820 							+ request->actual,
821 							transfer_size))
822 
823 					return;
824 			}
825 #endif	/* Mentor's DMA */
826 
827 			fifo_count = request->length - request->actual;
828 			dev_dbg(musb->controller, "%s OUT/RX pio fifo %d/%d, maxpacket %d\n",
829 					musb_ep->end_point.name,
830 					len, fifo_count,
831 					musb_ep->packet_sz);
832 
833 			fifo_count = min_t(unsigned, len, fifo_count);
834 
835 #ifdef	CONFIG_USB_TUSB_OMAP_DMA
836 			if (tusb_dma_omap() && is_buffer_mapped(req)) {
837 				struct dma_controller *c = musb->dma_controller;
838 				struct dma_channel *channel = musb_ep->dma;
839 				u32 dma_addr = request->dma + request->actual;
840 				int ret;
841 
842 				ret = c->channel_program(channel,
843 						musb_ep->packet_sz,
844 						channel->desired_mode,
845 						dma_addr,
846 						fifo_count);
847 				if (ret)
848 					return;
849 			}
850 #endif
851 			/*
852 			 * Unmap the dma buffer back to cpu if dma channel
853 			 * programming fails. This buffer is mapped if the
854 			 * channel allocation is successful
855 			 */
856 			 if (is_buffer_mapped(req)) {
857 				unmap_dma_buffer(req, musb);
858 
859 				/*
860 				 * Clear DMAENAB and AUTOCLEAR for the
861 				 * PIO mode transfer
862 				 */
863 				csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
864 				musb_writew(epio, MUSB_RXCSR, csr);
865 			}
866 
867 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
868 					(request->buf + request->actual));
869 			request->actual += fifo_count;
870 
871 			/* REVISIT if we left anything in the fifo, flush
872 			 * it and report -EOVERFLOW
873 			 */
874 
875 			/* ack the read! */
876 			csr |= MUSB_RXCSR_P_WZC_BITS;
877 			csr &= ~MUSB_RXCSR_RXPKTRDY;
878 			musb_writew(epio, MUSB_RXCSR, csr);
879 		}
880 	}
881 
882 	/* reach the end or short packet detected */
883 	if (request->actual == request->length || len < musb_ep->packet_sz)
884 		musb_g_giveback(musb_ep, request, 0);
885 }
886 
887 /*
888  * Data ready for a request; called from IRQ
889  */
890 void musb_g_rx(struct musb *musb, u8 epnum)
891 {
892 	u16			csr;
893 	struct musb_request	*req;
894 	struct usb_request	*request;
895 	void __iomem		*mbase = musb->mregs;
896 	struct musb_ep		*musb_ep;
897 	void __iomem		*epio = musb->endpoints[epnum].regs;
898 	struct dma_channel	*dma;
899 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
900 
901 	if (hw_ep->is_shared_fifo)
902 		musb_ep = &hw_ep->ep_in;
903 	else
904 		musb_ep = &hw_ep->ep_out;
905 
906 	musb_ep_select(mbase, epnum);
907 
908 	req = next_request(musb_ep);
909 	if (!req)
910 		return;
911 
912 	request = &req->request;
913 
914 	csr = musb_readw(epio, MUSB_RXCSR);
915 	dma = is_dma_capable() ? musb_ep->dma : NULL;
916 
917 	dev_dbg(musb->controller, "<== %s, rxcsr %04x%s %p\n", musb_ep->end_point.name,
918 			csr, dma ? " (dma)" : "", request);
919 
920 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
921 		csr |= MUSB_RXCSR_P_WZC_BITS;
922 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
923 		musb_writew(epio, MUSB_RXCSR, csr);
924 		return;
925 	}
926 
927 	if (csr & MUSB_RXCSR_P_OVERRUN) {
928 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
929 		csr &= ~MUSB_RXCSR_P_OVERRUN;
930 		musb_writew(epio, MUSB_RXCSR, csr);
931 
932 		dev_dbg(musb->controller, "%s iso overrun on %p\n", musb_ep->name, request);
933 		if (request->status == -EINPROGRESS)
934 			request->status = -EOVERFLOW;
935 	}
936 	if (csr & MUSB_RXCSR_INCOMPRX) {
937 		/* REVISIT not necessarily an error */
938 		dev_dbg(musb->controller, "%s, incomprx\n", musb_ep->end_point.name);
939 	}
940 
941 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
942 		/* "should not happen"; likely RXPKTRDY pending for DMA */
943 		dev_dbg(musb->controller, "%s busy, csr %04x\n",
944 			musb_ep->end_point.name, csr);
945 		return;
946 	}
947 
948 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
949 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
950 				| MUSB_RXCSR_DMAENAB
951 				| MUSB_RXCSR_DMAMODE);
952 		musb_writew(epio, MUSB_RXCSR,
953 			MUSB_RXCSR_P_WZC_BITS | csr);
954 
955 		request->actual += musb_ep->dma->actual_len;
956 
957 		dev_dbg(musb->controller, "RXCSR%d %04x, dma off, %04x, len %zu, req %p\n",
958 			epnum, csr,
959 			musb_readw(epio, MUSB_RXCSR),
960 			musb_ep->dma->actual_len, request);
961 
962 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
963 	defined(CONFIG_USB_UX500_DMA)
964 		/* Autoclear doesn't clear RxPktRdy for short packets */
965 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
966 				|| (dma->actual_len
967 					& (musb_ep->packet_sz - 1))) {
968 			/* ack the read! */
969 			csr &= ~MUSB_RXCSR_RXPKTRDY;
970 			musb_writew(epio, MUSB_RXCSR, csr);
971 		}
972 
973 		/* incomplete, and not short? wait for next IN packet */
974 		if ((request->actual < request->length)
975 				&& (musb_ep->dma->actual_len
976 					== musb_ep->packet_sz)) {
977 			/* In double buffer case, continue to unload fifo if
978  			 * there is Rx packet in FIFO.
979  			 **/
980 			csr = musb_readw(epio, MUSB_RXCSR);
981 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
982 				hw_ep->rx_double_buffered)
983 				goto exit;
984 			return;
985 		}
986 #endif
987 		musb_g_giveback(musb_ep, request, 0);
988 
989 		req = next_request(musb_ep);
990 		if (!req)
991 			return;
992 	}
993 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
994 	defined(CONFIG_USB_UX500_DMA)
995 exit:
996 #endif
997 	/* Analyze request */
998 	rxstate(musb, req);
999 }
1000 
1001 /* ------------------------------------------------------------ */
1002 
1003 static int musb_gadget_enable(struct usb_ep *ep,
1004 			const struct usb_endpoint_descriptor *desc)
1005 {
1006 	unsigned long		flags;
1007 	struct musb_ep		*musb_ep;
1008 	struct musb_hw_ep	*hw_ep;
1009 	void __iomem		*regs;
1010 	struct musb		*musb;
1011 	void __iomem	*mbase;
1012 	u8		epnum;
1013 	u16		csr;
1014 	unsigned	tmp;
1015 	int		status = -EINVAL;
1016 
1017 	if (!ep || !desc)
1018 		return -EINVAL;
1019 
1020 	musb_ep = to_musb_ep(ep);
1021 	hw_ep = musb_ep->hw_ep;
1022 	regs = hw_ep->regs;
1023 	musb = musb_ep->musb;
1024 	mbase = musb->mregs;
1025 	epnum = musb_ep->current_epnum;
1026 
1027 	spin_lock_irqsave(&musb->lock, flags);
1028 
1029 	if (musb_ep->desc) {
1030 		status = -EBUSY;
1031 		goto fail;
1032 	}
1033 	musb_ep->type = usb_endpoint_type(desc);
1034 
1035 	/* check direction and (later) maxpacket size against endpoint */
1036 	if (usb_endpoint_num(desc) != epnum)
1037 		goto fail;
1038 
1039 	/* REVISIT this rules out high bandwidth periodic transfers */
1040 	tmp = usb_endpoint_maxp(desc);
1041 	if (tmp & ~0x07ff) {
1042 		int ok;
1043 
1044 		if (usb_endpoint_dir_in(desc))
1045 			ok = musb->hb_iso_tx;
1046 		else
1047 			ok = musb->hb_iso_rx;
1048 
1049 		if (!ok) {
1050 			dev_dbg(musb->controller, "no support for high bandwidth ISO\n");
1051 			goto fail;
1052 		}
1053 		musb_ep->hb_mult = (tmp >> 11) & 3;
1054 	} else {
1055 		musb_ep->hb_mult = 0;
1056 	}
1057 
1058 	musb_ep->packet_sz = tmp & 0x7ff;
1059 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
1060 
1061 	/* enable the interrupts for the endpoint, set the endpoint
1062 	 * packet size (or fail), set the mode, clear the fifo
1063 	 */
1064 	musb_ep_select(mbase, epnum);
1065 	if (usb_endpoint_dir_in(desc)) {
1066 		u16 int_txe = musb_readw(mbase, MUSB_INTRTXE);
1067 
1068 		if (hw_ep->is_shared_fifo)
1069 			musb_ep->is_in = 1;
1070 		if (!musb_ep->is_in)
1071 			goto fail;
1072 
1073 		if (tmp > hw_ep->max_packet_sz_tx) {
1074 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1075 			goto fail;
1076 		}
1077 
1078 		int_txe |= (1 << epnum);
1079 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
1080 
1081 		/* REVISIT if can_bulk_split(), use by updating "tmp";
1082 		 * likewise high bandwidth periodic tx
1083 		 */
1084 		/* Set TXMAXP with the FIFO size of the endpoint
1085 		 * to disable double buffering mode.
1086 		 */
1087 		if (musb->double_buffer_not_ok)
1088 			musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
1089 		else
1090 			musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
1091 					| (musb_ep->hb_mult << 11));
1092 
1093 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
1094 		if (musb_readw(regs, MUSB_TXCSR)
1095 				& MUSB_TXCSR_FIFONOTEMPTY)
1096 			csr |= MUSB_TXCSR_FLUSHFIFO;
1097 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1098 			csr |= MUSB_TXCSR_P_ISO;
1099 
1100 		/* set twice in case of double buffering */
1101 		musb_writew(regs, MUSB_TXCSR, csr);
1102 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1103 		musb_writew(regs, MUSB_TXCSR, csr);
1104 
1105 	} else {
1106 		u16 int_rxe = musb_readw(mbase, MUSB_INTRRXE);
1107 
1108 		if (hw_ep->is_shared_fifo)
1109 			musb_ep->is_in = 0;
1110 		if (musb_ep->is_in)
1111 			goto fail;
1112 
1113 		if (tmp > hw_ep->max_packet_sz_rx) {
1114 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1115 			goto fail;
1116 		}
1117 
1118 		int_rxe |= (1 << epnum);
1119 		musb_writew(mbase, MUSB_INTRRXE, int_rxe);
1120 
1121 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1122 		 * likewise high bandwidth periodic rx
1123 		 */
1124 		/* Set RXMAXP with the FIFO size of the endpoint
1125 		 * to disable double buffering mode.
1126 		 */
1127 		if (musb->double_buffer_not_ok)
1128 			musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_tx);
1129 		else
1130 			musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1131 					| (musb_ep->hb_mult << 11));
1132 
1133 		/* force shared fifo to OUT-only mode */
1134 		if (hw_ep->is_shared_fifo) {
1135 			csr = musb_readw(regs, MUSB_TXCSR);
1136 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1137 			musb_writew(regs, MUSB_TXCSR, csr);
1138 		}
1139 
1140 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1141 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1142 			csr |= MUSB_RXCSR_P_ISO;
1143 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1144 			csr |= MUSB_RXCSR_DISNYET;
1145 
1146 		/* set twice in case of double buffering */
1147 		musb_writew(regs, MUSB_RXCSR, csr);
1148 		musb_writew(regs, MUSB_RXCSR, csr);
1149 	}
1150 
1151 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1152 	 * for some reason you run out of channels here.
1153 	 */
1154 	if (is_dma_capable() && musb->dma_controller) {
1155 		struct dma_controller	*c = musb->dma_controller;
1156 
1157 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1158 				(desc->bEndpointAddress & USB_DIR_IN));
1159 	} else
1160 		musb_ep->dma = NULL;
1161 
1162 	musb_ep->desc = desc;
1163 	musb_ep->busy = 0;
1164 	musb_ep->wedged = 0;
1165 	status = 0;
1166 
1167 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1168 			musb_driver_name, musb_ep->end_point.name,
1169 			({ char *s; switch (musb_ep->type) {
1170 			case USB_ENDPOINT_XFER_BULK:	s = "bulk"; break;
1171 			case USB_ENDPOINT_XFER_INT:	s = "int"; break;
1172 			default:			s = "iso"; break;
1173 			}; s; }),
1174 			musb_ep->is_in ? "IN" : "OUT",
1175 			musb_ep->dma ? "dma, " : "",
1176 			musb_ep->packet_sz);
1177 
1178 	schedule_work(&musb->irq_work);
1179 
1180 fail:
1181 	spin_unlock_irqrestore(&musb->lock, flags);
1182 	return status;
1183 }
1184 
1185 /*
1186  * Disable an endpoint flushing all requests queued.
1187  */
1188 static int musb_gadget_disable(struct usb_ep *ep)
1189 {
1190 	unsigned long	flags;
1191 	struct musb	*musb;
1192 	u8		epnum;
1193 	struct musb_ep	*musb_ep;
1194 	void __iomem	*epio;
1195 	int		status = 0;
1196 
1197 	musb_ep = to_musb_ep(ep);
1198 	musb = musb_ep->musb;
1199 	epnum = musb_ep->current_epnum;
1200 	epio = musb->endpoints[epnum].regs;
1201 
1202 	spin_lock_irqsave(&musb->lock, flags);
1203 	musb_ep_select(musb->mregs, epnum);
1204 
1205 	/* zero the endpoint sizes */
1206 	if (musb_ep->is_in) {
1207 		u16 int_txe = musb_readw(musb->mregs, MUSB_INTRTXE);
1208 		int_txe &= ~(1 << epnum);
1209 		musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
1210 		musb_writew(epio, MUSB_TXMAXP, 0);
1211 	} else {
1212 		u16 int_rxe = musb_readw(musb->mregs, MUSB_INTRRXE);
1213 		int_rxe &= ~(1 << epnum);
1214 		musb_writew(musb->mregs, MUSB_INTRRXE, int_rxe);
1215 		musb_writew(epio, MUSB_RXMAXP, 0);
1216 	}
1217 
1218 	musb_ep->desc = NULL;
1219 
1220 	/* abort all pending DMA and requests */
1221 	nuke(musb_ep, -ESHUTDOWN);
1222 
1223 	schedule_work(&musb->irq_work);
1224 
1225 	spin_unlock_irqrestore(&(musb->lock), flags);
1226 
1227 	dev_dbg(musb->controller, "%s\n", musb_ep->end_point.name);
1228 
1229 	return status;
1230 }
1231 
1232 /*
1233  * Allocate a request for an endpoint.
1234  * Reused by ep0 code.
1235  */
1236 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1237 {
1238 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1239 	struct musb		*musb = musb_ep->musb;
1240 	struct musb_request	*request = NULL;
1241 
1242 	request = kzalloc(sizeof *request, gfp_flags);
1243 	if (!request) {
1244 		dev_dbg(musb->controller, "not enough memory\n");
1245 		return NULL;
1246 	}
1247 
1248 	request->request.dma = DMA_ADDR_INVALID;
1249 	request->epnum = musb_ep->current_epnum;
1250 	request->ep = musb_ep;
1251 
1252 	return &request->request;
1253 }
1254 
1255 /*
1256  * Free a request
1257  * Reused by ep0 code.
1258  */
1259 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1260 {
1261 	kfree(to_musb_request(req));
1262 }
1263 
1264 static LIST_HEAD(buffers);
1265 
1266 struct free_record {
1267 	struct list_head	list;
1268 	struct device		*dev;
1269 	unsigned		bytes;
1270 	dma_addr_t		dma;
1271 };
1272 
1273 /*
1274  * Context: controller locked, IRQs blocked.
1275  */
1276 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1277 {
1278 	dev_dbg(musb->controller, "<== %s request %p len %u on hw_ep%d\n",
1279 		req->tx ? "TX/IN" : "RX/OUT",
1280 		&req->request, req->request.length, req->epnum);
1281 
1282 	musb_ep_select(musb->mregs, req->epnum);
1283 	if (req->tx)
1284 		txstate(musb, req);
1285 	else
1286 		rxstate(musb, req);
1287 }
1288 
1289 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1290 			gfp_t gfp_flags)
1291 {
1292 	struct musb_ep		*musb_ep;
1293 	struct musb_request	*request;
1294 	struct musb		*musb;
1295 	int			status = 0;
1296 	unsigned long		lockflags;
1297 
1298 	if (!ep || !req)
1299 		return -EINVAL;
1300 	if (!req->buf)
1301 		return -ENODATA;
1302 
1303 	musb_ep = to_musb_ep(ep);
1304 	musb = musb_ep->musb;
1305 
1306 	request = to_musb_request(req);
1307 	request->musb = musb;
1308 
1309 	if (request->ep != musb_ep)
1310 		return -EINVAL;
1311 
1312 	dev_dbg(musb->controller, "<== to %s request=%p\n", ep->name, req);
1313 
1314 	/* request is mine now... */
1315 	request->request.actual = 0;
1316 	request->request.status = -EINPROGRESS;
1317 	request->epnum = musb_ep->current_epnum;
1318 	request->tx = musb_ep->is_in;
1319 
1320 	map_dma_buffer(request, musb, musb_ep);
1321 
1322 	spin_lock_irqsave(&musb->lock, lockflags);
1323 
1324 	/* don't queue if the ep is down */
1325 	if (!musb_ep->desc) {
1326 		dev_dbg(musb->controller, "req %p queued to %s while ep %s\n",
1327 				req, ep->name, "disabled");
1328 		status = -ESHUTDOWN;
1329 		goto cleanup;
1330 	}
1331 
1332 	/* add request to the list */
1333 	list_add_tail(&request->list, &musb_ep->req_list);
1334 
1335 	/* it this is the head of the queue, start i/o ... */
1336 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next)
1337 		musb_ep_restart(musb, request);
1338 
1339 cleanup:
1340 	spin_unlock_irqrestore(&musb->lock, lockflags);
1341 	return status;
1342 }
1343 
1344 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1345 {
1346 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1347 	struct musb_request	*req = to_musb_request(request);
1348 	struct musb_request	*r;
1349 	unsigned long		flags;
1350 	int			status = 0;
1351 	struct musb		*musb = musb_ep->musb;
1352 
1353 	if (!ep || !request || to_musb_request(request)->ep != musb_ep)
1354 		return -EINVAL;
1355 
1356 	spin_lock_irqsave(&musb->lock, flags);
1357 
1358 	list_for_each_entry(r, &musb_ep->req_list, list) {
1359 		if (r == req)
1360 			break;
1361 	}
1362 	if (r != req) {
1363 		dev_dbg(musb->controller, "request %p not queued to %s\n", request, ep->name);
1364 		status = -EINVAL;
1365 		goto done;
1366 	}
1367 
1368 	/* if the hardware doesn't have the request, easy ... */
1369 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1370 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1371 
1372 	/* ... else abort the dma transfer ... */
1373 	else if (is_dma_capable() && musb_ep->dma) {
1374 		struct dma_controller	*c = musb->dma_controller;
1375 
1376 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1377 		if (c->channel_abort)
1378 			status = c->channel_abort(musb_ep->dma);
1379 		else
1380 			status = -EBUSY;
1381 		if (status == 0)
1382 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1383 	} else {
1384 		/* NOTE: by sticking to easily tested hardware/driver states,
1385 		 * we leave counting of in-flight packets imprecise.
1386 		 */
1387 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1388 	}
1389 
1390 done:
1391 	spin_unlock_irqrestore(&musb->lock, flags);
1392 	return status;
1393 }
1394 
1395 /*
1396  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1397  * data but will queue requests.
1398  *
1399  * exported to ep0 code
1400  */
1401 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1402 {
1403 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1404 	u8			epnum = musb_ep->current_epnum;
1405 	struct musb		*musb = musb_ep->musb;
1406 	void __iomem		*epio = musb->endpoints[epnum].regs;
1407 	void __iomem		*mbase;
1408 	unsigned long		flags;
1409 	u16			csr;
1410 	struct musb_request	*request;
1411 	int			status = 0;
1412 
1413 	if (!ep)
1414 		return -EINVAL;
1415 	mbase = musb->mregs;
1416 
1417 	spin_lock_irqsave(&musb->lock, flags);
1418 
1419 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1420 		status = -EINVAL;
1421 		goto done;
1422 	}
1423 
1424 	musb_ep_select(mbase, epnum);
1425 
1426 	request = next_request(musb_ep);
1427 	if (value) {
1428 		if (request) {
1429 			dev_dbg(musb->controller, "request in progress, cannot halt %s\n",
1430 			    ep->name);
1431 			status = -EAGAIN;
1432 			goto done;
1433 		}
1434 		/* Cannot portably stall with non-empty FIFO */
1435 		if (musb_ep->is_in) {
1436 			csr = musb_readw(epio, MUSB_TXCSR);
1437 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1438 				dev_dbg(musb->controller, "FIFO busy, cannot halt %s\n", ep->name);
1439 				status = -EAGAIN;
1440 				goto done;
1441 			}
1442 		}
1443 	} else
1444 		musb_ep->wedged = 0;
1445 
1446 	/* set/clear the stall and toggle bits */
1447 	dev_dbg(musb->controller, "%s: %s stall\n", ep->name, value ? "set" : "clear");
1448 	if (musb_ep->is_in) {
1449 		csr = musb_readw(epio, MUSB_TXCSR);
1450 		csr |= MUSB_TXCSR_P_WZC_BITS
1451 			| MUSB_TXCSR_CLRDATATOG;
1452 		if (value)
1453 			csr |= MUSB_TXCSR_P_SENDSTALL;
1454 		else
1455 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1456 				| MUSB_TXCSR_P_SENTSTALL);
1457 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1458 		musb_writew(epio, MUSB_TXCSR, csr);
1459 	} else {
1460 		csr = musb_readw(epio, MUSB_RXCSR);
1461 		csr |= MUSB_RXCSR_P_WZC_BITS
1462 			| MUSB_RXCSR_FLUSHFIFO
1463 			| MUSB_RXCSR_CLRDATATOG;
1464 		if (value)
1465 			csr |= MUSB_RXCSR_P_SENDSTALL;
1466 		else
1467 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1468 				| MUSB_RXCSR_P_SENTSTALL);
1469 		musb_writew(epio, MUSB_RXCSR, csr);
1470 	}
1471 
1472 	/* maybe start the first request in the queue */
1473 	if (!musb_ep->busy && !value && request) {
1474 		dev_dbg(musb->controller, "restarting the request\n");
1475 		musb_ep_restart(musb, request);
1476 	}
1477 
1478 done:
1479 	spin_unlock_irqrestore(&musb->lock, flags);
1480 	return status;
1481 }
1482 
1483 /*
1484  * Sets the halt feature with the clear requests ignored
1485  */
1486 static int musb_gadget_set_wedge(struct usb_ep *ep)
1487 {
1488 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1489 
1490 	if (!ep)
1491 		return -EINVAL;
1492 
1493 	musb_ep->wedged = 1;
1494 
1495 	return usb_ep_set_halt(ep);
1496 }
1497 
1498 static int musb_gadget_fifo_status(struct usb_ep *ep)
1499 {
1500 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1501 	void __iomem		*epio = musb_ep->hw_ep->regs;
1502 	int			retval = -EINVAL;
1503 
1504 	if (musb_ep->desc && !musb_ep->is_in) {
1505 		struct musb		*musb = musb_ep->musb;
1506 		int			epnum = musb_ep->current_epnum;
1507 		void __iomem		*mbase = musb->mregs;
1508 		unsigned long		flags;
1509 
1510 		spin_lock_irqsave(&musb->lock, flags);
1511 
1512 		musb_ep_select(mbase, epnum);
1513 		/* FIXME return zero unless RXPKTRDY is set */
1514 		retval = musb_readw(epio, MUSB_RXCOUNT);
1515 
1516 		spin_unlock_irqrestore(&musb->lock, flags);
1517 	}
1518 	return retval;
1519 }
1520 
1521 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1522 {
1523 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1524 	struct musb	*musb = musb_ep->musb;
1525 	u8		epnum = musb_ep->current_epnum;
1526 	void __iomem	*epio = musb->endpoints[epnum].regs;
1527 	void __iomem	*mbase;
1528 	unsigned long	flags;
1529 	u16		csr, int_txe;
1530 
1531 	mbase = musb->mregs;
1532 
1533 	spin_lock_irqsave(&musb->lock, flags);
1534 	musb_ep_select(mbase, (u8) epnum);
1535 
1536 	/* disable interrupts */
1537 	int_txe = musb_readw(mbase, MUSB_INTRTXE);
1538 	musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
1539 
1540 	if (musb_ep->is_in) {
1541 		csr = musb_readw(epio, MUSB_TXCSR);
1542 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1543 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1544 			/*
1545 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1546 			 * to interrupt current FIFO loading, but not flushing
1547 			 * the already loaded ones.
1548 			 */
1549 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1550 			musb_writew(epio, MUSB_TXCSR, csr);
1551 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1552 			musb_writew(epio, MUSB_TXCSR, csr);
1553 		}
1554 	} else {
1555 		csr = musb_readw(epio, MUSB_RXCSR);
1556 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1557 		musb_writew(epio, MUSB_RXCSR, csr);
1558 		musb_writew(epio, MUSB_RXCSR, csr);
1559 	}
1560 
1561 	/* re-enable interrupt */
1562 	musb_writew(mbase, MUSB_INTRTXE, int_txe);
1563 	spin_unlock_irqrestore(&musb->lock, flags);
1564 }
1565 
1566 static const struct usb_ep_ops musb_ep_ops = {
1567 	.enable		= musb_gadget_enable,
1568 	.disable	= musb_gadget_disable,
1569 	.alloc_request	= musb_alloc_request,
1570 	.free_request	= musb_free_request,
1571 	.queue		= musb_gadget_queue,
1572 	.dequeue	= musb_gadget_dequeue,
1573 	.set_halt	= musb_gadget_set_halt,
1574 	.set_wedge	= musb_gadget_set_wedge,
1575 	.fifo_status	= musb_gadget_fifo_status,
1576 	.fifo_flush	= musb_gadget_fifo_flush
1577 };
1578 
1579 /* ----------------------------------------------------------------------- */
1580 
1581 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1582 {
1583 	struct musb	*musb = gadget_to_musb(gadget);
1584 
1585 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1586 }
1587 
1588 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1589 {
1590 	struct musb	*musb = gadget_to_musb(gadget);
1591 	void __iomem	*mregs = musb->mregs;
1592 	unsigned long	flags;
1593 	int		status = -EINVAL;
1594 	u8		power, devctl;
1595 	int		retries;
1596 
1597 	spin_lock_irqsave(&musb->lock, flags);
1598 
1599 	switch (musb->xceiv->state) {
1600 	case OTG_STATE_B_PERIPHERAL:
1601 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1602 		 * that's part of the standard usb 1.1 state machine, and
1603 		 * doesn't affect OTG transitions.
1604 		 */
1605 		if (musb->may_wakeup && musb->is_suspended)
1606 			break;
1607 		goto done;
1608 	case OTG_STATE_B_IDLE:
1609 		/* Start SRP ... OTG not required. */
1610 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1611 		dev_dbg(musb->controller, "Sending SRP: devctl: %02x\n", devctl);
1612 		devctl |= MUSB_DEVCTL_SESSION;
1613 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1614 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1615 		retries = 100;
1616 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1617 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1618 			if (retries-- < 1)
1619 				break;
1620 		}
1621 		retries = 10000;
1622 		while (devctl & MUSB_DEVCTL_SESSION) {
1623 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1624 			if (retries-- < 1)
1625 				break;
1626 		}
1627 
1628 		spin_unlock_irqrestore(&musb->lock, flags);
1629 		otg_start_srp(musb->xceiv);
1630 		spin_lock_irqsave(&musb->lock, flags);
1631 
1632 		/* Block idling for at least 1s */
1633 		musb_platform_try_idle(musb,
1634 			jiffies + msecs_to_jiffies(1 * HZ));
1635 
1636 		status = 0;
1637 		goto done;
1638 	default:
1639 		dev_dbg(musb->controller, "Unhandled wake: %s\n",
1640 			otg_state_string(musb->xceiv->state));
1641 		goto done;
1642 	}
1643 
1644 	status = 0;
1645 
1646 	power = musb_readb(mregs, MUSB_POWER);
1647 	power |= MUSB_POWER_RESUME;
1648 	musb_writeb(mregs, MUSB_POWER, power);
1649 	dev_dbg(musb->controller, "issue wakeup\n");
1650 
1651 	/* FIXME do this next chunk in a timer callback, no udelay */
1652 	mdelay(2);
1653 
1654 	power = musb_readb(mregs, MUSB_POWER);
1655 	power &= ~MUSB_POWER_RESUME;
1656 	musb_writeb(mregs, MUSB_POWER, power);
1657 done:
1658 	spin_unlock_irqrestore(&musb->lock, flags);
1659 	return status;
1660 }
1661 
1662 static int
1663 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1664 {
1665 	struct musb	*musb = gadget_to_musb(gadget);
1666 
1667 	musb->is_self_powered = !!is_selfpowered;
1668 	return 0;
1669 }
1670 
1671 static void musb_pullup(struct musb *musb, int is_on)
1672 {
1673 	u8 power;
1674 
1675 	power = musb_readb(musb->mregs, MUSB_POWER);
1676 	if (is_on)
1677 		power |= MUSB_POWER_SOFTCONN;
1678 	else
1679 		power &= ~MUSB_POWER_SOFTCONN;
1680 
1681 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1682 
1683 	dev_dbg(musb->controller, "gadget D+ pullup %s\n",
1684 		is_on ? "on" : "off");
1685 	musb_writeb(musb->mregs, MUSB_POWER, power);
1686 }
1687 
1688 #if 0
1689 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1690 {
1691 	dev_dbg(musb->controller, "<= %s =>\n", __func__);
1692 
1693 	/*
1694 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1695 	 * though that can clear it), just musb_pullup().
1696 	 */
1697 
1698 	return -EINVAL;
1699 }
1700 #endif
1701 
1702 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1703 {
1704 	struct musb	*musb = gadget_to_musb(gadget);
1705 
1706 	if (!musb->xceiv->set_power)
1707 		return -EOPNOTSUPP;
1708 	return otg_set_power(musb->xceiv, mA);
1709 }
1710 
1711 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1712 {
1713 	struct musb	*musb = gadget_to_musb(gadget);
1714 	unsigned long	flags;
1715 
1716 	is_on = !!is_on;
1717 
1718 	pm_runtime_get_sync(musb->controller);
1719 
1720 	/* NOTE: this assumes we are sensing vbus; we'd rather
1721 	 * not pullup unless the B-session is active.
1722 	 */
1723 	spin_lock_irqsave(&musb->lock, flags);
1724 	if (is_on != musb->softconnect) {
1725 		musb->softconnect = is_on;
1726 		musb_pullup(musb, is_on);
1727 	}
1728 	spin_unlock_irqrestore(&musb->lock, flags);
1729 
1730 	pm_runtime_put(musb->controller);
1731 
1732 	return 0;
1733 }
1734 
1735 static int musb_gadget_start(struct usb_gadget *g,
1736 		struct usb_gadget_driver *driver);
1737 static int musb_gadget_stop(struct usb_gadget *g,
1738 		struct usb_gadget_driver *driver);
1739 
1740 static const struct usb_gadget_ops musb_gadget_operations = {
1741 	.get_frame		= musb_gadget_get_frame,
1742 	.wakeup			= musb_gadget_wakeup,
1743 	.set_selfpowered	= musb_gadget_set_self_powered,
1744 	/* .vbus_session		= musb_gadget_vbus_session, */
1745 	.vbus_draw		= musb_gadget_vbus_draw,
1746 	.pullup			= musb_gadget_pullup,
1747 	.udc_start		= musb_gadget_start,
1748 	.udc_stop		= musb_gadget_stop,
1749 };
1750 
1751 /* ----------------------------------------------------------------------- */
1752 
1753 /* Registration */
1754 
1755 /* Only this registration code "knows" the rule (from USB standards)
1756  * about there being only one external upstream port.  It assumes
1757  * all peripheral ports are external...
1758  */
1759 
1760 static void musb_gadget_release(struct device *dev)
1761 {
1762 	/* kref_put(WHAT) */
1763 	dev_dbg(dev, "%s\n", __func__);
1764 }
1765 
1766 
1767 static void __init
1768 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1769 {
1770 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1771 
1772 	memset(ep, 0, sizeof *ep);
1773 
1774 	ep->current_epnum = epnum;
1775 	ep->musb = musb;
1776 	ep->hw_ep = hw_ep;
1777 	ep->is_in = is_in;
1778 
1779 	INIT_LIST_HEAD(&ep->req_list);
1780 
1781 	sprintf(ep->name, "ep%d%s", epnum,
1782 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1783 				is_in ? "in" : "out"));
1784 	ep->end_point.name = ep->name;
1785 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1786 	if (!epnum) {
1787 		ep->end_point.maxpacket = 64;
1788 		ep->end_point.ops = &musb_g_ep0_ops;
1789 		musb->g.ep0 = &ep->end_point;
1790 	} else {
1791 		if (is_in)
1792 			ep->end_point.maxpacket = hw_ep->max_packet_sz_tx;
1793 		else
1794 			ep->end_point.maxpacket = hw_ep->max_packet_sz_rx;
1795 		ep->end_point.ops = &musb_ep_ops;
1796 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1797 	}
1798 }
1799 
1800 /*
1801  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1802  * to the rest of the driver state.
1803  */
1804 static inline void __init musb_g_init_endpoints(struct musb *musb)
1805 {
1806 	u8			epnum;
1807 	struct musb_hw_ep	*hw_ep;
1808 	unsigned		count = 0;
1809 
1810 	/* initialize endpoint list just once */
1811 	INIT_LIST_HEAD(&(musb->g.ep_list));
1812 
1813 	for (epnum = 0, hw_ep = musb->endpoints;
1814 			epnum < musb->nr_endpoints;
1815 			epnum++, hw_ep++) {
1816 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1817 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1818 			count++;
1819 		} else {
1820 			if (hw_ep->max_packet_sz_tx) {
1821 				init_peripheral_ep(musb, &hw_ep->ep_in,
1822 							epnum, 1);
1823 				count++;
1824 			}
1825 			if (hw_ep->max_packet_sz_rx) {
1826 				init_peripheral_ep(musb, &hw_ep->ep_out,
1827 							epnum, 0);
1828 				count++;
1829 			}
1830 		}
1831 	}
1832 }
1833 
1834 /* called once during driver setup to initialize and link into
1835  * the driver model; memory is zeroed.
1836  */
1837 int __init musb_gadget_setup(struct musb *musb)
1838 {
1839 	int status;
1840 
1841 	/* REVISIT minor race:  if (erroneously) setting up two
1842 	 * musb peripherals at the same time, only the bus lock
1843 	 * is probably held.
1844 	 */
1845 
1846 	musb->g.ops = &musb_gadget_operations;
1847 	musb->g.is_dualspeed = 1;
1848 	musb->g.speed = USB_SPEED_UNKNOWN;
1849 
1850 	/* this "gadget" abstracts/virtualizes the controller */
1851 	dev_set_name(&musb->g.dev, "gadget");
1852 	musb->g.dev.parent = musb->controller;
1853 	musb->g.dev.dma_mask = musb->controller->dma_mask;
1854 	musb->g.dev.release = musb_gadget_release;
1855 	musb->g.name = musb_driver_name;
1856 
1857 	if (is_otg_enabled(musb))
1858 		musb->g.is_otg = 1;
1859 
1860 	musb_g_init_endpoints(musb);
1861 
1862 	musb->is_active = 0;
1863 	musb_platform_try_idle(musb, 0);
1864 
1865 	status = device_register(&musb->g.dev);
1866 	if (status != 0) {
1867 		put_device(&musb->g.dev);
1868 		return status;
1869 	}
1870 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1871 	if (status)
1872 		goto err;
1873 
1874 	return 0;
1875 err:
1876 	musb->g.dev.parent = NULL;
1877 	device_unregister(&musb->g.dev);
1878 	return status;
1879 }
1880 
1881 void musb_gadget_cleanup(struct musb *musb)
1882 {
1883 	usb_del_gadget_udc(&musb->g);
1884 	if (musb->g.dev.parent)
1885 		device_unregister(&musb->g.dev);
1886 }
1887 
1888 /*
1889  * Register the gadget driver. Used by gadget drivers when
1890  * registering themselves with the controller.
1891  *
1892  * -EINVAL something went wrong (not driver)
1893  * -EBUSY another gadget is already using the controller
1894  * -ENOMEM no memory to perform the operation
1895  *
1896  * @param driver the gadget driver
1897  * @return <0 if error, 0 if everything is fine
1898  */
1899 static int musb_gadget_start(struct usb_gadget *g,
1900 		struct usb_gadget_driver *driver)
1901 {
1902 	struct musb		*musb = gadget_to_musb(g);
1903 	unsigned long		flags;
1904 	int			retval = -EINVAL;
1905 
1906 	if (driver->speed != USB_SPEED_HIGH)
1907 		goto err0;
1908 
1909 	pm_runtime_get_sync(musb->controller);
1910 
1911 	dev_dbg(musb->controller, "registering driver %s\n", driver->function);
1912 
1913 	musb->softconnect = 0;
1914 	musb->gadget_driver = driver;
1915 
1916 	spin_lock_irqsave(&musb->lock, flags);
1917 	musb->is_active = 1;
1918 
1919 	otg_set_peripheral(musb->xceiv, &musb->g);
1920 	musb->xceiv->state = OTG_STATE_B_IDLE;
1921 
1922 	/*
1923 	 * FIXME this ignores the softconnect flag.  Drivers are
1924 	 * allowed hold the peripheral inactive until for example
1925 	 * userspace hooks up printer hardware or DSP codecs, so
1926 	 * hosts only see fully functional devices.
1927 	 */
1928 
1929 	if (!is_otg_enabled(musb))
1930 		musb_start(musb);
1931 
1932 	spin_unlock_irqrestore(&musb->lock, flags);
1933 
1934 	if (is_otg_enabled(musb)) {
1935 		struct usb_hcd	*hcd = musb_to_hcd(musb);
1936 
1937 		dev_dbg(musb->controller, "OTG startup...\n");
1938 
1939 		/* REVISIT:  funcall to other code, which also
1940 		 * handles power budgeting ... this way also
1941 		 * ensures HdrcStart is indirectly called.
1942 		 */
1943 		retval = usb_add_hcd(musb_to_hcd(musb), -1, 0);
1944 		if (retval < 0) {
1945 			dev_dbg(musb->controller, "add_hcd failed, %d\n", retval);
1946 			goto err2;
1947 		}
1948 
1949 		if ((musb->xceiv->last_event == USB_EVENT_ID)
1950 					&& musb->xceiv->set_vbus)
1951 			otg_set_vbus(musb->xceiv, 1);
1952 
1953 		hcd->self.uses_pio_for_control = 1;
1954 	}
1955 	if (musb->xceiv->last_event == USB_EVENT_NONE)
1956 		pm_runtime_put(musb->controller);
1957 
1958 	return 0;
1959 
1960 err2:
1961 	if (!is_otg_enabled(musb))
1962 		musb_stop(musb);
1963 err0:
1964 	return retval;
1965 }
1966 
1967 static void stop_activity(struct musb *musb, struct usb_gadget_driver *driver)
1968 {
1969 	int			i;
1970 	struct musb_hw_ep	*hw_ep;
1971 
1972 	/* don't disconnect if it's not connected */
1973 	if (musb->g.speed == USB_SPEED_UNKNOWN)
1974 		driver = NULL;
1975 	else
1976 		musb->g.speed = USB_SPEED_UNKNOWN;
1977 
1978 	/* deactivate the hardware */
1979 	if (musb->softconnect) {
1980 		musb->softconnect = 0;
1981 		musb_pullup(musb, 0);
1982 	}
1983 	musb_stop(musb);
1984 
1985 	/* killing any outstanding requests will quiesce the driver;
1986 	 * then report disconnect
1987 	 */
1988 	if (driver) {
1989 		for (i = 0, hw_ep = musb->endpoints;
1990 				i < musb->nr_endpoints;
1991 				i++, hw_ep++) {
1992 			musb_ep_select(musb->mregs, i);
1993 			if (hw_ep->is_shared_fifo /* || !epnum */) {
1994 				nuke(&hw_ep->ep_in, -ESHUTDOWN);
1995 			} else {
1996 				if (hw_ep->max_packet_sz_tx)
1997 					nuke(&hw_ep->ep_in, -ESHUTDOWN);
1998 				if (hw_ep->max_packet_sz_rx)
1999 					nuke(&hw_ep->ep_out, -ESHUTDOWN);
2000 			}
2001 		}
2002 
2003 		spin_unlock(&musb->lock);
2004 		driver->disconnect(&musb->g);
2005 		spin_lock(&musb->lock);
2006 	}
2007 }
2008 
2009 /*
2010  * Unregister the gadget driver. Used by gadget drivers when
2011  * unregistering themselves from the controller.
2012  *
2013  * @param driver the gadget driver to unregister
2014  */
2015 static int musb_gadget_stop(struct usb_gadget *g,
2016 		struct usb_gadget_driver *driver)
2017 {
2018 	struct musb	*musb = gadget_to_musb(g);
2019 	unsigned long	flags;
2020 
2021 	if (musb->xceiv->last_event == USB_EVENT_NONE)
2022 		pm_runtime_get_sync(musb->controller);
2023 
2024 	/*
2025 	 * REVISIT always use otg_set_peripheral() here too;
2026 	 * this needs to shut down the OTG engine.
2027 	 */
2028 
2029 	spin_lock_irqsave(&musb->lock, flags);
2030 
2031 	musb_hnp_stop(musb);
2032 
2033 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2034 
2035 	musb->xceiv->state = OTG_STATE_UNDEFINED;
2036 	stop_activity(musb, driver);
2037 	otg_set_peripheral(musb->xceiv, NULL);
2038 
2039 	dev_dbg(musb->controller, "unregistering driver %s\n", driver->function);
2040 
2041 	musb->is_active = 0;
2042 	musb_platform_try_idle(musb, 0);
2043 	spin_unlock_irqrestore(&musb->lock, flags);
2044 
2045 	if (is_otg_enabled(musb)) {
2046 		usb_remove_hcd(musb_to_hcd(musb));
2047 		/* FIXME we need to be able to register another
2048 		 * gadget driver here and have everything work;
2049 		 * that currently misbehaves.
2050 		 */
2051 	}
2052 
2053 	if (!is_otg_enabled(musb))
2054 		musb_stop(musb);
2055 
2056 	pm_runtime_put(musb->controller);
2057 
2058 	return 0;
2059 }
2060 
2061 /* ----------------------------------------------------------------------- */
2062 
2063 /* lifecycle operations called through plat_uds.c */
2064 
2065 void musb_g_resume(struct musb *musb)
2066 {
2067 	musb->is_suspended = 0;
2068 	switch (musb->xceiv->state) {
2069 	case OTG_STATE_B_IDLE:
2070 		break;
2071 	case OTG_STATE_B_WAIT_ACON:
2072 	case OTG_STATE_B_PERIPHERAL:
2073 		musb->is_active = 1;
2074 		if (musb->gadget_driver && musb->gadget_driver->resume) {
2075 			spin_unlock(&musb->lock);
2076 			musb->gadget_driver->resume(&musb->g);
2077 			spin_lock(&musb->lock);
2078 		}
2079 		break;
2080 	default:
2081 		WARNING("unhandled RESUME transition (%s)\n",
2082 				otg_state_string(musb->xceiv->state));
2083 	}
2084 }
2085 
2086 /* called when SOF packets stop for 3+ msec */
2087 void musb_g_suspend(struct musb *musb)
2088 {
2089 	u8	devctl;
2090 
2091 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2092 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2093 
2094 	switch (musb->xceiv->state) {
2095 	case OTG_STATE_B_IDLE:
2096 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2097 			musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2098 		break;
2099 	case OTG_STATE_B_PERIPHERAL:
2100 		musb->is_suspended = 1;
2101 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
2102 			spin_unlock(&musb->lock);
2103 			musb->gadget_driver->suspend(&musb->g);
2104 			spin_lock(&musb->lock);
2105 		}
2106 		break;
2107 	default:
2108 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
2109 		 * A_PERIPHERAL may need care too
2110 		 */
2111 		WARNING("unhandled SUSPEND transition (%s)\n",
2112 				otg_state_string(musb->xceiv->state));
2113 	}
2114 }
2115 
2116 /* Called during SRP */
2117 void musb_g_wakeup(struct musb *musb)
2118 {
2119 	musb_gadget_wakeup(&musb->g);
2120 }
2121 
2122 /* called when VBUS drops below session threshold, and in other cases */
2123 void musb_g_disconnect(struct musb *musb)
2124 {
2125 	void __iomem	*mregs = musb->mregs;
2126 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
2127 
2128 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2129 
2130 	/* clear HR */
2131 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
2132 
2133 	/* don't draw vbus until new b-default session */
2134 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2135 
2136 	musb->g.speed = USB_SPEED_UNKNOWN;
2137 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
2138 		spin_unlock(&musb->lock);
2139 		musb->gadget_driver->disconnect(&musb->g);
2140 		spin_lock(&musb->lock);
2141 	}
2142 
2143 	switch (musb->xceiv->state) {
2144 	default:
2145 		dev_dbg(musb->controller, "Unhandled disconnect %s, setting a_idle\n",
2146 			otg_state_string(musb->xceiv->state));
2147 		musb->xceiv->state = OTG_STATE_A_IDLE;
2148 		MUSB_HST_MODE(musb);
2149 		break;
2150 	case OTG_STATE_A_PERIPHERAL:
2151 		musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2152 		MUSB_HST_MODE(musb);
2153 		break;
2154 	case OTG_STATE_B_WAIT_ACON:
2155 	case OTG_STATE_B_HOST:
2156 	case OTG_STATE_B_PERIPHERAL:
2157 	case OTG_STATE_B_IDLE:
2158 		musb->xceiv->state = OTG_STATE_B_IDLE;
2159 		break;
2160 	case OTG_STATE_B_SRP_INIT:
2161 		break;
2162 	}
2163 
2164 	musb->is_active = 0;
2165 }
2166 
2167 void musb_g_reset(struct musb *musb)
2168 __releases(musb->lock)
2169 __acquires(musb->lock)
2170 {
2171 	void __iomem	*mbase = musb->mregs;
2172 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2173 	u8		power;
2174 
2175 	dev_dbg(musb->controller, "<== %s addr=%x driver '%s'\n",
2176 			(devctl & MUSB_DEVCTL_BDEVICE)
2177 				? "B-Device" : "A-Device",
2178 			musb_readb(mbase, MUSB_FADDR),
2179 			musb->gadget_driver
2180 				? musb->gadget_driver->driver.name
2181 				: NULL
2182 			);
2183 
2184 	/* report disconnect, if we didn't already (flushing EP state) */
2185 	if (musb->g.speed != USB_SPEED_UNKNOWN)
2186 		musb_g_disconnect(musb);
2187 
2188 	/* clear HR */
2189 	else if (devctl & MUSB_DEVCTL_HR)
2190 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2191 
2192 
2193 	/* what speed did we negotiate? */
2194 	power = musb_readb(mbase, MUSB_POWER);
2195 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2196 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2197 
2198 	/* start in USB_STATE_DEFAULT */
2199 	musb->is_active = 1;
2200 	musb->is_suspended = 0;
2201 	MUSB_DEV_MODE(musb);
2202 	musb->address = 0;
2203 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2204 
2205 	musb->may_wakeup = 0;
2206 	musb->g.b_hnp_enable = 0;
2207 	musb->g.a_alt_hnp_support = 0;
2208 	musb->g.a_hnp_support = 0;
2209 
2210 	/* Normal reset, as B-Device;
2211 	 * or else after HNP, as A-Device
2212 	 */
2213 	if (devctl & MUSB_DEVCTL_BDEVICE) {
2214 		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2215 		musb->g.is_a_peripheral = 0;
2216 	} else if (is_otg_enabled(musb)) {
2217 		musb->xceiv->state = OTG_STATE_A_PERIPHERAL;
2218 		musb->g.is_a_peripheral = 1;
2219 	} else
2220 		WARN_ON(1);
2221 
2222 	/* start with default limits on VBUS power draw */
2223 	(void) musb_gadget_vbus_draw(&musb->g,
2224 			is_otg_enabled(musb) ? 8 : 100);
2225 }
2226