xref: /linux/drivers/usb/musb/musb_gadget.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1 /*
2  * MUSB OTG driver peripheral support
3  *
4  * Copyright 2005 Mentor Graphics Corporation
5  * Copyright (C) 2005-2006 by Texas Instruments
6  * Copyright (C) 2006-2007 Nokia Corporation
7  * Copyright (C) 2009 MontaVista Software, Inc. <source@mvista.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * version 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
21  * 02110-1301 USA
22  *
23  * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED
24  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
26  * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
29  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
30  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  */
35 
36 #include <linux/kernel.h>
37 #include <linux/list.h>
38 #include <linux/timer.h>
39 #include <linux/module.h>
40 #include <linux/smp.h>
41 #include <linux/spinlock.h>
42 #include <linux/delay.h>
43 #include <linux/dma-mapping.h>
44 #include <linux/slab.h>
45 
46 #include "musb_core.h"
47 
48 
49 /* MUSB PERIPHERAL status 3-mar-2006:
50  *
51  * - EP0 seems solid.  It passes both USBCV and usbtest control cases.
52  *   Minor glitches:
53  *
54  *     + remote wakeup to Linux hosts work, but saw USBCV failures;
55  *       in one test run (operator error?)
56  *     + endpoint halt tests -- in both usbtest and usbcv -- seem
57  *       to break when dma is enabled ... is something wrongly
58  *       clearing SENDSTALL?
59  *
60  * - Mass storage behaved ok when last tested.  Network traffic patterns
61  *   (with lots of short transfers etc) need retesting; they turn up the
62  *   worst cases of the DMA, since short packets are typical but are not
63  *   required.
64  *
65  * - TX/IN
66  *     + both pio and dma behave in with network and g_zero tests
67  *     + no cppi throughput issues other than no-hw-queueing
68  *     + failed with FLAT_REG (DaVinci)
69  *     + seems to behave with double buffering, PIO -and- CPPI
70  *     + with gadgetfs + AIO, requests got lost?
71  *
72  * - RX/OUT
73  *     + both pio and dma behave in with network and g_zero tests
74  *     + dma is slow in typical case (short_not_ok is clear)
75  *     + double buffering ok with PIO
76  *     + double buffering *FAILS* with CPPI, wrong data bytes sometimes
77  *     + request lossage observed with gadgetfs
78  *
79  * - ISO not tested ... might work, but only weakly isochronous
80  *
81  * - Gadget driver disabling of softconnect during bind() is ignored; so
82  *   drivers can't hold off host requests until userspace is ready.
83  *   (Workaround:  they can turn it off later.)
84  *
85  * - PORTABILITY (assumes PIO works):
86  *     + DaVinci, basically works with cppi dma
87  *     + OMAP 2430, ditto with mentor dma
88  *     + TUSB 6010, platform-specific dma in the works
89  */
90 
91 /* ----------------------------------------------------------------------- */
92 
93 #define is_buffer_mapped(req) (is_dma_capable() && \
94 					(req->map_state != UN_MAPPED))
95 
96 /* Maps the buffer to dma  */
97 
98 static inline void map_dma_buffer(struct musb_request *request,
99 			struct musb *musb, struct musb_ep *musb_ep)
100 {
101 	int compatible = true;
102 	struct dma_controller *dma = musb->dma_controller;
103 
104 	request->map_state = UN_MAPPED;
105 
106 	if (!is_dma_capable() || !musb_ep->dma)
107 		return;
108 
109 	/* Check if DMA engine can handle this request.
110 	 * DMA code must reject the USB request explicitly.
111 	 * Default behaviour is to map the request.
112 	 */
113 	if (dma->is_compatible)
114 		compatible = dma->is_compatible(musb_ep->dma,
115 				musb_ep->packet_sz, request->request.buf,
116 				request->request.length);
117 	if (!compatible)
118 		return;
119 
120 	if (request->request.dma == DMA_ADDR_INVALID) {
121 		request->request.dma = dma_map_single(
122 				musb->controller,
123 				request->request.buf,
124 				request->request.length,
125 				request->tx
126 					? DMA_TO_DEVICE
127 					: DMA_FROM_DEVICE);
128 		request->map_state = MUSB_MAPPED;
129 	} else {
130 		dma_sync_single_for_device(musb->controller,
131 			request->request.dma,
132 			request->request.length,
133 			request->tx
134 				? DMA_TO_DEVICE
135 				: DMA_FROM_DEVICE);
136 		request->map_state = PRE_MAPPED;
137 	}
138 }
139 
140 /* Unmap the buffer from dma and maps it back to cpu */
141 static inline void unmap_dma_buffer(struct musb_request *request,
142 				struct musb *musb)
143 {
144 	if (!is_buffer_mapped(request))
145 		return;
146 
147 	if (request->request.dma == DMA_ADDR_INVALID) {
148 		dev_vdbg(musb->controller,
149 				"not unmapping a never mapped buffer\n");
150 		return;
151 	}
152 	if (request->map_state == MUSB_MAPPED) {
153 		dma_unmap_single(musb->controller,
154 			request->request.dma,
155 			request->request.length,
156 			request->tx
157 				? DMA_TO_DEVICE
158 				: DMA_FROM_DEVICE);
159 		request->request.dma = DMA_ADDR_INVALID;
160 	} else { /* PRE_MAPPED */
161 		dma_sync_single_for_cpu(musb->controller,
162 			request->request.dma,
163 			request->request.length,
164 			request->tx
165 				? DMA_TO_DEVICE
166 				: DMA_FROM_DEVICE);
167 	}
168 	request->map_state = UN_MAPPED;
169 }
170 
171 /*
172  * Immediately complete a request.
173  *
174  * @param request the request to complete
175  * @param status the status to complete the request with
176  * Context: controller locked, IRQs blocked.
177  */
178 void musb_g_giveback(
179 	struct musb_ep		*ep,
180 	struct usb_request	*request,
181 	int			status)
182 __releases(ep->musb->lock)
183 __acquires(ep->musb->lock)
184 {
185 	struct musb_request	*req;
186 	struct musb		*musb;
187 	int			busy = ep->busy;
188 
189 	req = to_musb_request(request);
190 
191 	list_del(&req->list);
192 	if (req->request.status == -EINPROGRESS)
193 		req->request.status = status;
194 	musb = req->musb;
195 
196 	ep->busy = 1;
197 	spin_unlock(&musb->lock);
198 	unmap_dma_buffer(req, musb);
199 	if (request->status == 0)
200 		dev_dbg(musb->controller, "%s done request %p,  %d/%d\n",
201 				ep->end_point.name, request,
202 				req->request.actual, req->request.length);
203 	else
204 		dev_dbg(musb->controller, "%s request %p, %d/%d fault %d\n",
205 				ep->end_point.name, request,
206 				req->request.actual, req->request.length,
207 				request->status);
208 	req->request.complete(&req->ep->end_point, &req->request);
209 	spin_lock(&musb->lock);
210 	ep->busy = busy;
211 }
212 
213 /* ----------------------------------------------------------------------- */
214 
215 /*
216  * Abort requests queued to an endpoint using the status. Synchronous.
217  * caller locked controller and blocked irqs, and selected this ep.
218  */
219 static void nuke(struct musb_ep *ep, const int status)
220 {
221 	struct musb		*musb = ep->musb;
222 	struct musb_request	*req = NULL;
223 	void __iomem *epio = ep->musb->endpoints[ep->current_epnum].regs;
224 
225 	ep->busy = 1;
226 
227 	if (is_dma_capable() && ep->dma) {
228 		struct dma_controller	*c = ep->musb->dma_controller;
229 		int value;
230 
231 		if (ep->is_in) {
232 			/*
233 			 * The programming guide says that we must not clear
234 			 * the DMAMODE bit before DMAENAB, so we only
235 			 * clear it in the second write...
236 			 */
237 			musb_writew(epio, MUSB_TXCSR,
238 				    MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
239 			musb_writew(epio, MUSB_TXCSR,
240 					0 | MUSB_TXCSR_FLUSHFIFO);
241 		} else {
242 			musb_writew(epio, MUSB_RXCSR,
243 					0 | MUSB_RXCSR_FLUSHFIFO);
244 			musb_writew(epio, MUSB_RXCSR,
245 					0 | MUSB_RXCSR_FLUSHFIFO);
246 		}
247 
248 		value = c->channel_abort(ep->dma);
249 		dev_dbg(musb->controller, "%s: abort DMA --> %d\n",
250 				ep->name, value);
251 		c->channel_release(ep->dma);
252 		ep->dma = NULL;
253 	}
254 
255 	while (!list_empty(&ep->req_list)) {
256 		req = list_first_entry(&ep->req_list, struct musb_request, list);
257 		musb_g_giveback(ep, &req->request, status);
258 	}
259 }
260 
261 /* ----------------------------------------------------------------------- */
262 
263 /* Data transfers - pure PIO, pure DMA, or mixed mode */
264 
265 /*
266  * This assumes the separate CPPI engine is responding to DMA requests
267  * from the usb core ... sequenced a bit differently from mentor dma.
268  */
269 
270 static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
271 {
272 	if (can_bulk_split(musb, ep->type))
273 		return ep->hw_ep->max_packet_sz_tx;
274 	else
275 		return ep->packet_sz;
276 }
277 
278 
279 #ifdef CONFIG_USB_INVENTRA_DMA
280 
281 /* Peripheral tx (IN) using Mentor DMA works as follows:
282 	Only mode 0 is used for transfers <= wPktSize,
283 	mode 1 is used for larger transfers,
284 
285 	One of the following happens:
286 	- Host sends IN token which causes an endpoint interrupt
287 		-> TxAvail
288 			-> if DMA is currently busy, exit.
289 			-> if queue is non-empty, txstate().
290 
291 	- Request is queued by the gadget driver.
292 		-> if queue was previously empty, txstate()
293 
294 	txstate()
295 		-> start
296 		  /\	-> setup DMA
297 		  |     (data is transferred to the FIFO, then sent out when
298 		  |	IN token(s) are recd from Host.
299 		  |		-> DMA interrupt on completion
300 		  |		   calls TxAvail.
301 		  |		      -> stop DMA, ~DMAENAB,
302 		  |		      -> set TxPktRdy for last short pkt or zlp
303 		  |		      -> Complete Request
304 		  |		      -> Continue next request (call txstate)
305 		  |___________________________________|
306 
307  * Non-Mentor DMA engines can of course work differently, such as by
308  * upleveling from irq-per-packet to irq-per-buffer.
309  */
310 
311 #endif
312 
313 /*
314  * An endpoint is transmitting data. This can be called either from
315  * the IRQ routine or from ep.queue() to kickstart a request on an
316  * endpoint.
317  *
318  * Context: controller locked, IRQs blocked, endpoint selected
319  */
320 static void txstate(struct musb *musb, struct musb_request *req)
321 {
322 	u8			epnum = req->epnum;
323 	struct musb_ep		*musb_ep;
324 	void __iomem		*epio = musb->endpoints[epnum].regs;
325 	struct usb_request	*request;
326 	u16			fifo_count = 0, csr;
327 	int			use_dma = 0;
328 
329 	musb_ep = req->ep;
330 
331 	/* we shouldn't get here while DMA is active ... but we do ... */
332 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
333 		dev_dbg(musb->controller, "dma pending...\n");
334 		return;
335 	}
336 
337 	/* read TXCSR before */
338 	csr = musb_readw(epio, MUSB_TXCSR);
339 
340 	request = &req->request;
341 	fifo_count = min(max_ep_writesize(musb, musb_ep),
342 			(int)(request->length - request->actual));
343 
344 	if (csr & MUSB_TXCSR_TXPKTRDY) {
345 		dev_dbg(musb->controller, "%s old packet still ready , txcsr %03x\n",
346 				musb_ep->end_point.name, csr);
347 		return;
348 	}
349 
350 	if (csr & MUSB_TXCSR_P_SENDSTALL) {
351 		dev_dbg(musb->controller, "%s stalling, txcsr %03x\n",
352 				musb_ep->end_point.name, csr);
353 		return;
354 	}
355 
356 	dev_dbg(musb->controller, "hw_ep%d, maxpacket %d, fifo count %d, txcsr %03x\n",
357 			epnum, musb_ep->packet_sz, fifo_count,
358 			csr);
359 
360 #ifndef	CONFIG_MUSB_PIO_ONLY
361 	if (is_buffer_mapped(req)) {
362 		struct dma_controller	*c = musb->dma_controller;
363 		size_t request_size;
364 
365 		/* setup DMA, then program endpoint CSR */
366 		request_size = min_t(size_t, request->length - request->actual,
367 					musb_ep->dma->max_len);
368 
369 		use_dma = (request->dma != DMA_ADDR_INVALID);
370 
371 		/* MUSB_TXCSR_P_ISO is still set correctly */
372 
373 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
374 		{
375 			if (request_size < musb_ep->packet_sz)
376 				musb_ep->dma->desired_mode = 0;
377 			else
378 				musb_ep->dma->desired_mode = 1;
379 
380 			use_dma = use_dma && c->channel_program(
381 					musb_ep->dma, musb_ep->packet_sz,
382 					musb_ep->dma->desired_mode,
383 					request->dma + request->actual, request_size);
384 			if (use_dma) {
385 				if (musb_ep->dma->desired_mode == 0) {
386 					/*
387 					 * We must not clear the DMAMODE bit
388 					 * before the DMAENAB bit -- and the
389 					 * latter doesn't always get cleared
390 					 * before we get here...
391 					 */
392 					csr &= ~(MUSB_TXCSR_AUTOSET
393 						| MUSB_TXCSR_DMAENAB);
394 					musb_writew(epio, MUSB_TXCSR, csr
395 						| MUSB_TXCSR_P_WZC_BITS);
396 					csr &= ~MUSB_TXCSR_DMAMODE;
397 					csr |= (MUSB_TXCSR_DMAENAB |
398 							MUSB_TXCSR_MODE);
399 					/* against programming guide */
400 				} else {
401 					csr |= (MUSB_TXCSR_DMAENAB
402 							| MUSB_TXCSR_DMAMODE
403 							| MUSB_TXCSR_MODE);
404 					if (!musb_ep->hb_mult)
405 						csr |= MUSB_TXCSR_AUTOSET;
406 				}
407 				csr &= ~MUSB_TXCSR_P_UNDERRUN;
408 
409 				musb_writew(epio, MUSB_TXCSR, csr);
410 			}
411 		}
412 
413 #elif defined(CONFIG_USB_TI_CPPI_DMA)
414 		/* program endpoint CSR first, then setup DMA */
415 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
416 		csr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_DMAMODE |
417 		       MUSB_TXCSR_MODE;
418 		musb_writew(epio, MUSB_TXCSR,
419 			(MUSB_TXCSR_P_WZC_BITS & ~MUSB_TXCSR_P_UNDERRUN)
420 				| csr);
421 
422 		/* ensure writebuffer is empty */
423 		csr = musb_readw(epio, MUSB_TXCSR);
424 
425 		/* NOTE host side sets DMAENAB later than this; both are
426 		 * OK since the transfer dma glue (between CPPI and Mentor
427 		 * fifos) just tells CPPI it could start.  Data only moves
428 		 * to the USB TX fifo when both fifos are ready.
429 		 */
430 
431 		/* "mode" is irrelevant here; handle terminating ZLPs like
432 		 * PIO does, since the hardware RNDIS mode seems unreliable
433 		 * except for the last-packet-is-already-short case.
434 		 */
435 		use_dma = use_dma && c->channel_program(
436 				musb_ep->dma, musb_ep->packet_sz,
437 				0,
438 				request->dma + request->actual,
439 				request_size);
440 		if (!use_dma) {
441 			c->channel_release(musb_ep->dma);
442 			musb_ep->dma = NULL;
443 			csr &= ~MUSB_TXCSR_DMAENAB;
444 			musb_writew(epio, MUSB_TXCSR, csr);
445 			/* invariant: prequest->buf is non-null */
446 		}
447 #elif defined(CONFIG_USB_TUSB_OMAP_DMA)
448 		use_dma = use_dma && c->channel_program(
449 				musb_ep->dma, musb_ep->packet_sz,
450 				request->zero,
451 				request->dma + request->actual,
452 				request_size);
453 #endif
454 	}
455 #endif
456 
457 	if (!use_dma) {
458 		/*
459 		 * Unmap the dma buffer back to cpu if dma channel
460 		 * programming fails
461 		 */
462 		unmap_dma_buffer(req, musb);
463 
464 		musb_write_fifo(musb_ep->hw_ep, fifo_count,
465 				(u8 *) (request->buf + request->actual));
466 		request->actual += fifo_count;
467 		csr |= MUSB_TXCSR_TXPKTRDY;
468 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
469 		musb_writew(epio, MUSB_TXCSR, csr);
470 	}
471 
472 	/* host may already have the data when this message shows... */
473 	dev_dbg(musb->controller, "%s TX/IN %s len %d/%d, txcsr %04x, fifo %d/%d\n",
474 			musb_ep->end_point.name, use_dma ? "dma" : "pio",
475 			request->actual, request->length,
476 			musb_readw(epio, MUSB_TXCSR),
477 			fifo_count,
478 			musb_readw(epio, MUSB_TXMAXP));
479 }
480 
481 /*
482  * FIFO state update (e.g. data ready).
483  * Called from IRQ,  with controller locked.
484  */
485 void musb_g_tx(struct musb *musb, u8 epnum)
486 {
487 	u16			csr;
488 	struct musb_request	*req;
489 	struct usb_request	*request;
490 	u8 __iomem		*mbase = musb->mregs;
491 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_in;
492 	void __iomem		*epio = musb->endpoints[epnum].regs;
493 	struct dma_channel	*dma;
494 
495 	musb_ep_select(mbase, epnum);
496 	req = next_request(musb_ep);
497 	request = &req->request;
498 
499 	csr = musb_readw(epio, MUSB_TXCSR);
500 	dev_dbg(musb->controller, "<== %s, txcsr %04x\n", musb_ep->end_point.name, csr);
501 
502 	dma = is_dma_capable() ? musb_ep->dma : NULL;
503 
504 	/*
505 	 * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX
506 	 * probably rates reporting as a host error.
507 	 */
508 	if (csr & MUSB_TXCSR_P_SENTSTALL) {
509 		csr |=	MUSB_TXCSR_P_WZC_BITS;
510 		csr &= ~MUSB_TXCSR_P_SENTSTALL;
511 		musb_writew(epio, MUSB_TXCSR, csr);
512 		return;
513 	}
514 
515 	if (csr & MUSB_TXCSR_P_UNDERRUN) {
516 		/* We NAKed, no big deal... little reason to care. */
517 		csr |=	 MUSB_TXCSR_P_WZC_BITS;
518 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
519 		musb_writew(epio, MUSB_TXCSR, csr);
520 		dev_vdbg(musb->controller, "underrun on ep%d, req %p\n",
521 				epnum, request);
522 	}
523 
524 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
525 		/*
526 		 * SHOULD NOT HAPPEN... has with CPPI though, after
527 		 * changing SENDSTALL (and other cases); harmless?
528 		 */
529 		dev_dbg(musb->controller, "%s dma still busy?\n", musb_ep->end_point.name);
530 		return;
531 	}
532 
533 	if (request) {
534 		u8	is_dma = 0;
535 
536 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
537 			is_dma = 1;
538 			csr |= MUSB_TXCSR_P_WZC_BITS;
539 			csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
540 				 MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET);
541 			musb_writew(epio, MUSB_TXCSR, csr);
542 			/* Ensure writebuffer is empty. */
543 			csr = musb_readw(epio, MUSB_TXCSR);
544 			request->actual += musb_ep->dma->actual_len;
545 			dev_dbg(musb->controller, "TXCSR%d %04x, DMA off, len %zu, req %p\n",
546 				epnum, csr, musb_ep->dma->actual_len, request);
547 		}
548 
549 		/*
550 		 * First, maybe a terminating short packet. Some DMA
551 		 * engines might handle this by themselves.
552 		 */
553 		if ((request->zero && request->length
554 			&& (request->length % musb_ep->packet_sz == 0)
555 			&& (request->actual == request->length))
556 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_UX500_DMA)
557 			|| (is_dma && (!dma->desired_mode ||
558 				(request->actual &
559 					(musb_ep->packet_sz - 1))))
560 #endif
561 		) {
562 			/*
563 			 * On DMA completion, FIFO may not be
564 			 * available yet...
565 			 */
566 			if (csr & MUSB_TXCSR_TXPKTRDY)
567 				return;
568 
569 			dev_dbg(musb->controller, "sending zero pkt\n");
570 			musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
571 					| MUSB_TXCSR_TXPKTRDY);
572 			request->zero = 0;
573 		}
574 
575 		if (request->actual == request->length) {
576 			musb_g_giveback(musb_ep, request, 0);
577 			req = musb_ep->desc ? next_request(musb_ep) : NULL;
578 			if (!req) {
579 				dev_dbg(musb->controller, "%s idle now\n",
580 					musb_ep->end_point.name);
581 				return;
582 			}
583 		}
584 
585 		txstate(musb, req);
586 	}
587 }
588 
589 /* ------------------------------------------------------------ */
590 
591 #ifdef CONFIG_USB_INVENTRA_DMA
592 
593 /* Peripheral rx (OUT) using Mentor DMA works as follows:
594 	- Only mode 0 is used.
595 
596 	- Request is queued by the gadget class driver.
597 		-> if queue was previously empty, rxstate()
598 
599 	- Host sends OUT token which causes an endpoint interrupt
600 	  /\      -> RxReady
601 	  |	      -> if request queued, call rxstate
602 	  |		/\	-> setup DMA
603 	  |		|	     -> DMA interrupt on completion
604 	  |		|		-> RxReady
605 	  |		|		      -> stop DMA
606 	  |		|		      -> ack the read
607 	  |		|		      -> if data recd = max expected
608 	  |		|				by the request, or host
609 	  |		|				sent a short packet,
610 	  |		|				complete the request,
611 	  |		|				and start the next one.
612 	  |		|_____________________________________|
613 	  |					 else just wait for the host
614 	  |					    to send the next OUT token.
615 	  |__________________________________________________|
616 
617  * Non-Mentor DMA engines can of course work differently.
618  */
619 
620 #endif
621 
622 /*
623  * Context: controller locked, IRQs blocked, endpoint selected
624  */
625 static void rxstate(struct musb *musb, struct musb_request *req)
626 {
627 	const u8		epnum = req->epnum;
628 	struct usb_request	*request = &req->request;
629 	struct musb_ep		*musb_ep;
630 	void __iomem		*epio = musb->endpoints[epnum].regs;
631 	unsigned		fifo_count = 0;
632 	u16			len;
633 	u16			csr = musb_readw(epio, MUSB_RXCSR);
634 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
635 	u8			use_mode_1;
636 
637 	if (hw_ep->is_shared_fifo)
638 		musb_ep = &hw_ep->ep_in;
639 	else
640 		musb_ep = &hw_ep->ep_out;
641 
642 	len = musb_ep->packet_sz;
643 
644 	/* We shouldn't get here while DMA is active, but we do... */
645 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
646 		dev_dbg(musb->controller, "DMA pending...\n");
647 		return;
648 	}
649 
650 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
651 		dev_dbg(musb->controller, "%s stalling, RXCSR %04x\n",
652 		    musb_ep->end_point.name, csr);
653 		return;
654 	}
655 
656 	if (is_cppi_enabled() && is_buffer_mapped(req)) {
657 		struct dma_controller	*c = musb->dma_controller;
658 		struct dma_channel	*channel = musb_ep->dma;
659 
660 		/* NOTE:  CPPI won't actually stop advancing the DMA
661 		 * queue after short packet transfers, so this is almost
662 		 * always going to run as IRQ-per-packet DMA so that
663 		 * faults will be handled correctly.
664 		 */
665 		if (c->channel_program(channel,
666 				musb_ep->packet_sz,
667 				!request->short_not_ok,
668 				request->dma + request->actual,
669 				request->length - request->actual)) {
670 
671 			/* make sure that if an rxpkt arrived after the irq,
672 			 * the cppi engine will be ready to take it as soon
673 			 * as DMA is enabled
674 			 */
675 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
676 					| MUSB_RXCSR_DMAMODE);
677 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
678 			musb_writew(epio, MUSB_RXCSR, csr);
679 			return;
680 		}
681 	}
682 
683 	if (csr & MUSB_RXCSR_RXPKTRDY) {
684 		len = musb_readw(epio, MUSB_RXCOUNT);
685 
686 		/*
687 		 * Enable Mode 1 on RX transfers only when short_not_ok flag
688 		 * is set. Currently short_not_ok flag is set only from
689 		 * file_storage and f_mass_storage drivers
690 		 */
691 
692 		if (request->short_not_ok && len == musb_ep->packet_sz)
693 			use_mode_1 = 1;
694 		else
695 			use_mode_1 = 0;
696 
697 		if (request->actual < request->length) {
698 #ifdef CONFIG_USB_INVENTRA_DMA
699 			if (is_buffer_mapped(req)) {
700 				struct dma_controller	*c;
701 				struct dma_channel	*channel;
702 				int			use_dma = 0;
703 
704 				c = musb->dma_controller;
705 				channel = musb_ep->dma;
706 
707 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
708 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
709 	 * completion. We only get interrupts from DMA controller.
710 	 *
711 	 * We could operate in DMA mode 1 if we knew the size of the tranfer
712 	 * in advance. For mass storage class, request->length = what the host
713 	 * sends, so that'd work.  But for pretty much everything else,
714 	 * request->length is routinely more than what the host sends. For
715 	 * most these gadgets, end of is signified either by a short packet,
716 	 * or filling the last byte of the buffer.  (Sending extra data in
717 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
718 	 * we don't get DMA completion interrupt for short packets.
719 	 *
720 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
721 	 * to get endpoint interrupt on every DMA req, but that didn't seem
722 	 * to work reliably.
723 	 *
724 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
725 	 * then becomes usable as a runtime "use mode 1" hint...
726 	 */
727 
728 				/* Experimental: Mode1 works with mass storage use cases */
729 				if (use_mode_1) {
730 					csr |= MUSB_RXCSR_AUTOCLEAR;
731 					musb_writew(epio, MUSB_RXCSR, csr);
732 					csr |= MUSB_RXCSR_DMAENAB;
733 					musb_writew(epio, MUSB_RXCSR, csr);
734 
735 					/*
736 					 * this special sequence (enabling and then
737 					 * disabling MUSB_RXCSR_DMAMODE) is required
738 					 * to get DMAReq to activate
739 					 */
740 					musb_writew(epio, MUSB_RXCSR,
741 						csr | MUSB_RXCSR_DMAMODE);
742 					musb_writew(epio, MUSB_RXCSR, csr);
743 
744 				} else {
745 					if (!musb_ep->hb_mult &&
746 						musb_ep->hw_ep->rx_double_buffered)
747 						csr |= MUSB_RXCSR_AUTOCLEAR;
748 					csr |= MUSB_RXCSR_DMAENAB;
749 					musb_writew(epio, MUSB_RXCSR, csr);
750 				}
751 
752 				if (request->actual < request->length) {
753 					int transfer_size = 0;
754 					if (use_mode_1) {
755 						transfer_size = min(request->length - request->actual,
756 								channel->max_len);
757 						musb_ep->dma->desired_mode = 1;
758 					} else {
759 						transfer_size = min(request->length - request->actual,
760 								(unsigned)len);
761 						musb_ep->dma->desired_mode = 0;
762 					}
763 
764 					use_dma = c->channel_program(
765 							channel,
766 							musb_ep->packet_sz,
767 							channel->desired_mode,
768 							request->dma
769 							+ request->actual,
770 							transfer_size);
771 				}
772 
773 				if (use_dma)
774 					return;
775 			}
776 #elif defined(CONFIG_USB_UX500_DMA)
777 			if ((is_buffer_mapped(req)) &&
778 				(request->actual < request->length)) {
779 
780 				struct dma_controller *c;
781 				struct dma_channel *channel;
782 				int transfer_size = 0;
783 
784 				c = musb->dma_controller;
785 				channel = musb_ep->dma;
786 
787 				/* In case first packet is short */
788 				if (len < musb_ep->packet_sz)
789 					transfer_size = len;
790 				else if (request->short_not_ok)
791 					transfer_size =	min(request->length -
792 							request->actual,
793 							channel->max_len);
794 				else
795 					transfer_size = min(request->length -
796 							request->actual,
797 							(unsigned)len);
798 
799 				csr &= ~MUSB_RXCSR_DMAMODE;
800 				csr |= (MUSB_RXCSR_DMAENAB |
801 					MUSB_RXCSR_AUTOCLEAR);
802 
803 				musb_writew(epio, MUSB_RXCSR, csr);
804 
805 				if (transfer_size <= musb_ep->packet_sz) {
806 					musb_ep->dma->desired_mode = 0;
807 				} else {
808 					musb_ep->dma->desired_mode = 1;
809 					/* Mode must be set after DMAENAB */
810 					csr |= MUSB_RXCSR_DMAMODE;
811 					musb_writew(epio, MUSB_RXCSR, csr);
812 				}
813 
814 				if (c->channel_program(channel,
815 							musb_ep->packet_sz,
816 							channel->desired_mode,
817 							request->dma
818 							+ request->actual,
819 							transfer_size))
820 
821 					return;
822 			}
823 #endif	/* Mentor's DMA */
824 
825 			fifo_count = request->length - request->actual;
826 			dev_dbg(musb->controller, "%s OUT/RX pio fifo %d/%d, maxpacket %d\n",
827 					musb_ep->end_point.name,
828 					len, fifo_count,
829 					musb_ep->packet_sz);
830 
831 			fifo_count = min_t(unsigned, len, fifo_count);
832 
833 #ifdef	CONFIG_USB_TUSB_OMAP_DMA
834 			if (tusb_dma_omap() && is_buffer_mapped(req)) {
835 				struct dma_controller *c = musb->dma_controller;
836 				struct dma_channel *channel = musb_ep->dma;
837 				u32 dma_addr = request->dma + request->actual;
838 				int ret;
839 
840 				ret = c->channel_program(channel,
841 						musb_ep->packet_sz,
842 						channel->desired_mode,
843 						dma_addr,
844 						fifo_count);
845 				if (ret)
846 					return;
847 			}
848 #endif
849 			/*
850 			 * Unmap the dma buffer back to cpu if dma channel
851 			 * programming fails. This buffer is mapped if the
852 			 * channel allocation is successful
853 			 */
854 			 if (is_buffer_mapped(req)) {
855 				unmap_dma_buffer(req, musb);
856 
857 				/*
858 				 * Clear DMAENAB and AUTOCLEAR for the
859 				 * PIO mode transfer
860 				 */
861 				csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
862 				musb_writew(epio, MUSB_RXCSR, csr);
863 			}
864 
865 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
866 					(request->buf + request->actual));
867 			request->actual += fifo_count;
868 
869 			/* REVISIT if we left anything in the fifo, flush
870 			 * it and report -EOVERFLOW
871 			 */
872 
873 			/* ack the read! */
874 			csr |= MUSB_RXCSR_P_WZC_BITS;
875 			csr &= ~MUSB_RXCSR_RXPKTRDY;
876 			musb_writew(epio, MUSB_RXCSR, csr);
877 		}
878 	}
879 
880 	/* reach the end or short packet detected */
881 	if (request->actual == request->length || len < musb_ep->packet_sz)
882 		musb_g_giveback(musb_ep, request, 0);
883 }
884 
885 /*
886  * Data ready for a request; called from IRQ
887  */
888 void musb_g_rx(struct musb *musb, u8 epnum)
889 {
890 	u16			csr;
891 	struct musb_request	*req;
892 	struct usb_request	*request;
893 	void __iomem		*mbase = musb->mregs;
894 	struct musb_ep		*musb_ep;
895 	void __iomem		*epio = musb->endpoints[epnum].regs;
896 	struct dma_channel	*dma;
897 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
898 
899 	if (hw_ep->is_shared_fifo)
900 		musb_ep = &hw_ep->ep_in;
901 	else
902 		musb_ep = &hw_ep->ep_out;
903 
904 	musb_ep_select(mbase, epnum);
905 
906 	req = next_request(musb_ep);
907 	if (!req)
908 		return;
909 
910 	request = &req->request;
911 
912 	csr = musb_readw(epio, MUSB_RXCSR);
913 	dma = is_dma_capable() ? musb_ep->dma : NULL;
914 
915 	dev_dbg(musb->controller, "<== %s, rxcsr %04x%s %p\n", musb_ep->end_point.name,
916 			csr, dma ? " (dma)" : "", request);
917 
918 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
919 		csr |= MUSB_RXCSR_P_WZC_BITS;
920 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
921 		musb_writew(epio, MUSB_RXCSR, csr);
922 		return;
923 	}
924 
925 	if (csr & MUSB_RXCSR_P_OVERRUN) {
926 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
927 		csr &= ~MUSB_RXCSR_P_OVERRUN;
928 		musb_writew(epio, MUSB_RXCSR, csr);
929 
930 		dev_dbg(musb->controller, "%s iso overrun on %p\n", musb_ep->name, request);
931 		if (request->status == -EINPROGRESS)
932 			request->status = -EOVERFLOW;
933 	}
934 	if (csr & MUSB_RXCSR_INCOMPRX) {
935 		/* REVISIT not necessarily an error */
936 		dev_dbg(musb->controller, "%s, incomprx\n", musb_ep->end_point.name);
937 	}
938 
939 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
940 		/* "should not happen"; likely RXPKTRDY pending for DMA */
941 		dev_dbg(musb->controller, "%s busy, csr %04x\n",
942 			musb_ep->end_point.name, csr);
943 		return;
944 	}
945 
946 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
947 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
948 				| MUSB_RXCSR_DMAENAB
949 				| MUSB_RXCSR_DMAMODE);
950 		musb_writew(epio, MUSB_RXCSR,
951 			MUSB_RXCSR_P_WZC_BITS | csr);
952 
953 		request->actual += musb_ep->dma->actual_len;
954 
955 		dev_dbg(musb->controller, "RXCSR%d %04x, dma off, %04x, len %zu, req %p\n",
956 			epnum, csr,
957 			musb_readw(epio, MUSB_RXCSR),
958 			musb_ep->dma->actual_len, request);
959 
960 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
961 	defined(CONFIG_USB_UX500_DMA)
962 		/* Autoclear doesn't clear RxPktRdy for short packets */
963 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
964 				|| (dma->actual_len
965 					& (musb_ep->packet_sz - 1))) {
966 			/* ack the read! */
967 			csr &= ~MUSB_RXCSR_RXPKTRDY;
968 			musb_writew(epio, MUSB_RXCSR, csr);
969 		}
970 
971 		/* incomplete, and not short? wait for next IN packet */
972 		if ((request->actual < request->length)
973 				&& (musb_ep->dma->actual_len
974 					== musb_ep->packet_sz)) {
975 			/* In double buffer case, continue to unload fifo if
976  			 * there is Rx packet in FIFO.
977  			 **/
978 			csr = musb_readw(epio, MUSB_RXCSR);
979 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
980 				hw_ep->rx_double_buffered)
981 				goto exit;
982 			return;
983 		}
984 #endif
985 		musb_g_giveback(musb_ep, request, 0);
986 
987 		req = next_request(musb_ep);
988 		if (!req)
989 			return;
990 	}
991 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
992 	defined(CONFIG_USB_UX500_DMA)
993 exit:
994 #endif
995 	/* Analyze request */
996 	rxstate(musb, req);
997 }
998 
999 /* ------------------------------------------------------------ */
1000 
1001 static int musb_gadget_enable(struct usb_ep *ep,
1002 			const struct usb_endpoint_descriptor *desc)
1003 {
1004 	unsigned long		flags;
1005 	struct musb_ep		*musb_ep;
1006 	struct musb_hw_ep	*hw_ep;
1007 	void __iomem		*regs;
1008 	struct musb		*musb;
1009 	void __iomem	*mbase;
1010 	u8		epnum;
1011 	u16		csr;
1012 	unsigned	tmp;
1013 	int		status = -EINVAL;
1014 
1015 	if (!ep || !desc)
1016 		return -EINVAL;
1017 
1018 	musb_ep = to_musb_ep(ep);
1019 	hw_ep = musb_ep->hw_ep;
1020 	regs = hw_ep->regs;
1021 	musb = musb_ep->musb;
1022 	mbase = musb->mregs;
1023 	epnum = musb_ep->current_epnum;
1024 
1025 	spin_lock_irqsave(&musb->lock, flags);
1026 
1027 	if (musb_ep->desc) {
1028 		status = -EBUSY;
1029 		goto fail;
1030 	}
1031 	musb_ep->type = usb_endpoint_type(desc);
1032 
1033 	/* check direction and (later) maxpacket size against endpoint */
1034 	if (usb_endpoint_num(desc) != epnum)
1035 		goto fail;
1036 
1037 	/* REVISIT this rules out high bandwidth periodic transfers */
1038 	tmp = usb_endpoint_maxp(desc);
1039 	if (tmp & ~0x07ff) {
1040 		int ok;
1041 
1042 		if (usb_endpoint_dir_in(desc))
1043 			ok = musb->hb_iso_tx;
1044 		else
1045 			ok = musb->hb_iso_rx;
1046 
1047 		if (!ok) {
1048 			dev_dbg(musb->controller, "no support for high bandwidth ISO\n");
1049 			goto fail;
1050 		}
1051 		musb_ep->hb_mult = (tmp >> 11) & 3;
1052 	} else {
1053 		musb_ep->hb_mult = 0;
1054 	}
1055 
1056 	musb_ep->packet_sz = tmp & 0x7ff;
1057 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
1058 
1059 	/* enable the interrupts for the endpoint, set the endpoint
1060 	 * packet size (or fail), set the mode, clear the fifo
1061 	 */
1062 	musb_ep_select(mbase, epnum);
1063 	if (usb_endpoint_dir_in(desc)) {
1064 		u16 int_txe = musb_readw(mbase, MUSB_INTRTXE);
1065 
1066 		if (hw_ep->is_shared_fifo)
1067 			musb_ep->is_in = 1;
1068 		if (!musb_ep->is_in)
1069 			goto fail;
1070 
1071 		if (tmp > hw_ep->max_packet_sz_tx) {
1072 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1073 			goto fail;
1074 		}
1075 
1076 		int_txe |= (1 << epnum);
1077 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
1078 
1079 		/* REVISIT if can_bulk_split(), use by updating "tmp";
1080 		 * likewise high bandwidth periodic tx
1081 		 */
1082 		/* Set TXMAXP with the FIFO size of the endpoint
1083 		 * to disable double buffering mode.
1084 		 */
1085 		if (musb->double_buffer_not_ok)
1086 			musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
1087 		else
1088 			musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
1089 					| (musb_ep->hb_mult << 11));
1090 
1091 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
1092 		if (musb_readw(regs, MUSB_TXCSR)
1093 				& MUSB_TXCSR_FIFONOTEMPTY)
1094 			csr |= MUSB_TXCSR_FLUSHFIFO;
1095 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1096 			csr |= MUSB_TXCSR_P_ISO;
1097 
1098 		/* set twice in case of double buffering */
1099 		musb_writew(regs, MUSB_TXCSR, csr);
1100 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1101 		musb_writew(regs, MUSB_TXCSR, csr);
1102 
1103 	} else {
1104 		u16 int_rxe = musb_readw(mbase, MUSB_INTRRXE);
1105 
1106 		if (hw_ep->is_shared_fifo)
1107 			musb_ep->is_in = 0;
1108 		if (musb_ep->is_in)
1109 			goto fail;
1110 
1111 		if (tmp > hw_ep->max_packet_sz_rx) {
1112 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1113 			goto fail;
1114 		}
1115 
1116 		int_rxe |= (1 << epnum);
1117 		musb_writew(mbase, MUSB_INTRRXE, int_rxe);
1118 
1119 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1120 		 * likewise high bandwidth periodic rx
1121 		 */
1122 		/* Set RXMAXP with the FIFO size of the endpoint
1123 		 * to disable double buffering mode.
1124 		 */
1125 		if (musb->double_buffer_not_ok)
1126 			musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_tx);
1127 		else
1128 			musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1129 					| (musb_ep->hb_mult << 11));
1130 
1131 		/* force shared fifo to OUT-only mode */
1132 		if (hw_ep->is_shared_fifo) {
1133 			csr = musb_readw(regs, MUSB_TXCSR);
1134 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1135 			musb_writew(regs, MUSB_TXCSR, csr);
1136 		}
1137 
1138 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1139 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1140 			csr |= MUSB_RXCSR_P_ISO;
1141 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1142 			csr |= MUSB_RXCSR_DISNYET;
1143 
1144 		/* set twice in case of double buffering */
1145 		musb_writew(regs, MUSB_RXCSR, csr);
1146 		musb_writew(regs, MUSB_RXCSR, csr);
1147 	}
1148 
1149 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1150 	 * for some reason you run out of channels here.
1151 	 */
1152 	if (is_dma_capable() && musb->dma_controller) {
1153 		struct dma_controller	*c = musb->dma_controller;
1154 
1155 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1156 				(desc->bEndpointAddress & USB_DIR_IN));
1157 	} else
1158 		musb_ep->dma = NULL;
1159 
1160 	musb_ep->desc = desc;
1161 	musb_ep->busy = 0;
1162 	musb_ep->wedged = 0;
1163 	status = 0;
1164 
1165 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1166 			musb_driver_name, musb_ep->end_point.name,
1167 			({ char *s; switch (musb_ep->type) {
1168 			case USB_ENDPOINT_XFER_BULK:	s = "bulk"; break;
1169 			case USB_ENDPOINT_XFER_INT:	s = "int"; break;
1170 			default:			s = "iso"; break;
1171 			}; s; }),
1172 			musb_ep->is_in ? "IN" : "OUT",
1173 			musb_ep->dma ? "dma, " : "",
1174 			musb_ep->packet_sz);
1175 
1176 	schedule_work(&musb->irq_work);
1177 
1178 fail:
1179 	spin_unlock_irqrestore(&musb->lock, flags);
1180 	return status;
1181 }
1182 
1183 /*
1184  * Disable an endpoint flushing all requests queued.
1185  */
1186 static int musb_gadget_disable(struct usb_ep *ep)
1187 {
1188 	unsigned long	flags;
1189 	struct musb	*musb;
1190 	u8		epnum;
1191 	struct musb_ep	*musb_ep;
1192 	void __iomem	*epio;
1193 	int		status = 0;
1194 
1195 	musb_ep = to_musb_ep(ep);
1196 	musb = musb_ep->musb;
1197 	epnum = musb_ep->current_epnum;
1198 	epio = musb->endpoints[epnum].regs;
1199 
1200 	spin_lock_irqsave(&musb->lock, flags);
1201 	musb_ep_select(musb->mregs, epnum);
1202 
1203 	/* zero the endpoint sizes */
1204 	if (musb_ep->is_in) {
1205 		u16 int_txe = musb_readw(musb->mregs, MUSB_INTRTXE);
1206 		int_txe &= ~(1 << epnum);
1207 		musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
1208 		musb_writew(epio, MUSB_TXMAXP, 0);
1209 	} else {
1210 		u16 int_rxe = musb_readw(musb->mregs, MUSB_INTRRXE);
1211 		int_rxe &= ~(1 << epnum);
1212 		musb_writew(musb->mregs, MUSB_INTRRXE, int_rxe);
1213 		musb_writew(epio, MUSB_RXMAXP, 0);
1214 	}
1215 
1216 	musb_ep->desc = NULL;
1217 
1218 	/* abort all pending DMA and requests */
1219 	nuke(musb_ep, -ESHUTDOWN);
1220 
1221 	schedule_work(&musb->irq_work);
1222 
1223 	spin_unlock_irqrestore(&(musb->lock), flags);
1224 
1225 	dev_dbg(musb->controller, "%s\n", musb_ep->end_point.name);
1226 
1227 	return status;
1228 }
1229 
1230 /*
1231  * Allocate a request for an endpoint.
1232  * Reused by ep0 code.
1233  */
1234 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1235 {
1236 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1237 	struct musb		*musb = musb_ep->musb;
1238 	struct musb_request	*request = NULL;
1239 
1240 	request = kzalloc(sizeof *request, gfp_flags);
1241 	if (!request) {
1242 		dev_dbg(musb->controller, "not enough memory\n");
1243 		return NULL;
1244 	}
1245 
1246 	request->request.dma = DMA_ADDR_INVALID;
1247 	request->epnum = musb_ep->current_epnum;
1248 	request->ep = musb_ep;
1249 
1250 	return &request->request;
1251 }
1252 
1253 /*
1254  * Free a request
1255  * Reused by ep0 code.
1256  */
1257 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1258 {
1259 	kfree(to_musb_request(req));
1260 }
1261 
1262 static LIST_HEAD(buffers);
1263 
1264 struct free_record {
1265 	struct list_head	list;
1266 	struct device		*dev;
1267 	unsigned		bytes;
1268 	dma_addr_t		dma;
1269 };
1270 
1271 /*
1272  * Context: controller locked, IRQs blocked.
1273  */
1274 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1275 {
1276 	dev_dbg(musb->controller, "<== %s request %p len %u on hw_ep%d\n",
1277 		req->tx ? "TX/IN" : "RX/OUT",
1278 		&req->request, req->request.length, req->epnum);
1279 
1280 	musb_ep_select(musb->mregs, req->epnum);
1281 	if (req->tx)
1282 		txstate(musb, req);
1283 	else
1284 		rxstate(musb, req);
1285 }
1286 
1287 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1288 			gfp_t gfp_flags)
1289 {
1290 	struct musb_ep		*musb_ep;
1291 	struct musb_request	*request;
1292 	struct musb		*musb;
1293 	int			status = 0;
1294 	unsigned long		lockflags;
1295 
1296 	if (!ep || !req)
1297 		return -EINVAL;
1298 	if (!req->buf)
1299 		return -ENODATA;
1300 
1301 	musb_ep = to_musb_ep(ep);
1302 	musb = musb_ep->musb;
1303 
1304 	request = to_musb_request(req);
1305 	request->musb = musb;
1306 
1307 	if (request->ep != musb_ep)
1308 		return -EINVAL;
1309 
1310 	dev_dbg(musb->controller, "<== to %s request=%p\n", ep->name, req);
1311 
1312 	/* request is mine now... */
1313 	request->request.actual = 0;
1314 	request->request.status = -EINPROGRESS;
1315 	request->epnum = musb_ep->current_epnum;
1316 	request->tx = musb_ep->is_in;
1317 
1318 	map_dma_buffer(request, musb, musb_ep);
1319 
1320 	spin_lock_irqsave(&musb->lock, lockflags);
1321 
1322 	/* don't queue if the ep is down */
1323 	if (!musb_ep->desc) {
1324 		dev_dbg(musb->controller, "req %p queued to %s while ep %s\n",
1325 				req, ep->name, "disabled");
1326 		status = -ESHUTDOWN;
1327 		goto cleanup;
1328 	}
1329 
1330 	/* add request to the list */
1331 	list_add_tail(&request->list, &musb_ep->req_list);
1332 
1333 	/* it this is the head of the queue, start i/o ... */
1334 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next)
1335 		musb_ep_restart(musb, request);
1336 
1337 cleanup:
1338 	spin_unlock_irqrestore(&musb->lock, lockflags);
1339 	return status;
1340 }
1341 
1342 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1343 {
1344 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1345 	struct musb_request	*req = to_musb_request(request);
1346 	struct musb_request	*r;
1347 	unsigned long		flags;
1348 	int			status = 0;
1349 	struct musb		*musb = musb_ep->musb;
1350 
1351 	if (!ep || !request || to_musb_request(request)->ep != musb_ep)
1352 		return -EINVAL;
1353 
1354 	spin_lock_irqsave(&musb->lock, flags);
1355 
1356 	list_for_each_entry(r, &musb_ep->req_list, list) {
1357 		if (r == req)
1358 			break;
1359 	}
1360 	if (r != req) {
1361 		dev_dbg(musb->controller, "request %p not queued to %s\n", request, ep->name);
1362 		status = -EINVAL;
1363 		goto done;
1364 	}
1365 
1366 	/* if the hardware doesn't have the request, easy ... */
1367 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1368 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1369 
1370 	/* ... else abort the dma transfer ... */
1371 	else if (is_dma_capable() && musb_ep->dma) {
1372 		struct dma_controller	*c = musb->dma_controller;
1373 
1374 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1375 		if (c->channel_abort)
1376 			status = c->channel_abort(musb_ep->dma);
1377 		else
1378 			status = -EBUSY;
1379 		if (status == 0)
1380 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1381 	} else {
1382 		/* NOTE: by sticking to easily tested hardware/driver states,
1383 		 * we leave counting of in-flight packets imprecise.
1384 		 */
1385 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1386 	}
1387 
1388 done:
1389 	spin_unlock_irqrestore(&musb->lock, flags);
1390 	return status;
1391 }
1392 
1393 /*
1394  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1395  * data but will queue requests.
1396  *
1397  * exported to ep0 code
1398  */
1399 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1400 {
1401 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1402 	u8			epnum = musb_ep->current_epnum;
1403 	struct musb		*musb = musb_ep->musb;
1404 	void __iomem		*epio = musb->endpoints[epnum].regs;
1405 	void __iomem		*mbase;
1406 	unsigned long		flags;
1407 	u16			csr;
1408 	struct musb_request	*request;
1409 	int			status = 0;
1410 
1411 	if (!ep)
1412 		return -EINVAL;
1413 	mbase = musb->mregs;
1414 
1415 	spin_lock_irqsave(&musb->lock, flags);
1416 
1417 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1418 		status = -EINVAL;
1419 		goto done;
1420 	}
1421 
1422 	musb_ep_select(mbase, epnum);
1423 
1424 	request = next_request(musb_ep);
1425 	if (value) {
1426 		if (request) {
1427 			dev_dbg(musb->controller, "request in progress, cannot halt %s\n",
1428 			    ep->name);
1429 			status = -EAGAIN;
1430 			goto done;
1431 		}
1432 		/* Cannot portably stall with non-empty FIFO */
1433 		if (musb_ep->is_in) {
1434 			csr = musb_readw(epio, MUSB_TXCSR);
1435 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1436 				dev_dbg(musb->controller, "FIFO busy, cannot halt %s\n", ep->name);
1437 				status = -EAGAIN;
1438 				goto done;
1439 			}
1440 		}
1441 	} else
1442 		musb_ep->wedged = 0;
1443 
1444 	/* set/clear the stall and toggle bits */
1445 	dev_dbg(musb->controller, "%s: %s stall\n", ep->name, value ? "set" : "clear");
1446 	if (musb_ep->is_in) {
1447 		csr = musb_readw(epio, MUSB_TXCSR);
1448 		csr |= MUSB_TXCSR_P_WZC_BITS
1449 			| MUSB_TXCSR_CLRDATATOG;
1450 		if (value)
1451 			csr |= MUSB_TXCSR_P_SENDSTALL;
1452 		else
1453 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1454 				| MUSB_TXCSR_P_SENTSTALL);
1455 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1456 		musb_writew(epio, MUSB_TXCSR, csr);
1457 	} else {
1458 		csr = musb_readw(epio, MUSB_RXCSR);
1459 		csr |= MUSB_RXCSR_P_WZC_BITS
1460 			| MUSB_RXCSR_FLUSHFIFO
1461 			| MUSB_RXCSR_CLRDATATOG;
1462 		if (value)
1463 			csr |= MUSB_RXCSR_P_SENDSTALL;
1464 		else
1465 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1466 				| MUSB_RXCSR_P_SENTSTALL);
1467 		musb_writew(epio, MUSB_RXCSR, csr);
1468 	}
1469 
1470 	/* maybe start the first request in the queue */
1471 	if (!musb_ep->busy && !value && request) {
1472 		dev_dbg(musb->controller, "restarting the request\n");
1473 		musb_ep_restart(musb, request);
1474 	}
1475 
1476 done:
1477 	spin_unlock_irqrestore(&musb->lock, flags);
1478 	return status;
1479 }
1480 
1481 /*
1482  * Sets the halt feature with the clear requests ignored
1483  */
1484 static int musb_gadget_set_wedge(struct usb_ep *ep)
1485 {
1486 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1487 
1488 	if (!ep)
1489 		return -EINVAL;
1490 
1491 	musb_ep->wedged = 1;
1492 
1493 	return usb_ep_set_halt(ep);
1494 }
1495 
1496 static int musb_gadget_fifo_status(struct usb_ep *ep)
1497 {
1498 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1499 	void __iomem		*epio = musb_ep->hw_ep->regs;
1500 	int			retval = -EINVAL;
1501 
1502 	if (musb_ep->desc && !musb_ep->is_in) {
1503 		struct musb		*musb = musb_ep->musb;
1504 		int			epnum = musb_ep->current_epnum;
1505 		void __iomem		*mbase = musb->mregs;
1506 		unsigned long		flags;
1507 
1508 		spin_lock_irqsave(&musb->lock, flags);
1509 
1510 		musb_ep_select(mbase, epnum);
1511 		/* FIXME return zero unless RXPKTRDY is set */
1512 		retval = musb_readw(epio, MUSB_RXCOUNT);
1513 
1514 		spin_unlock_irqrestore(&musb->lock, flags);
1515 	}
1516 	return retval;
1517 }
1518 
1519 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1520 {
1521 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1522 	struct musb	*musb = musb_ep->musb;
1523 	u8		epnum = musb_ep->current_epnum;
1524 	void __iomem	*epio = musb->endpoints[epnum].regs;
1525 	void __iomem	*mbase;
1526 	unsigned long	flags;
1527 	u16		csr, int_txe;
1528 
1529 	mbase = musb->mregs;
1530 
1531 	spin_lock_irqsave(&musb->lock, flags);
1532 	musb_ep_select(mbase, (u8) epnum);
1533 
1534 	/* disable interrupts */
1535 	int_txe = musb_readw(mbase, MUSB_INTRTXE);
1536 	musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
1537 
1538 	if (musb_ep->is_in) {
1539 		csr = musb_readw(epio, MUSB_TXCSR);
1540 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1541 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1542 			/*
1543 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1544 			 * to interrupt current FIFO loading, but not flushing
1545 			 * the already loaded ones.
1546 			 */
1547 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1548 			musb_writew(epio, MUSB_TXCSR, csr);
1549 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1550 			musb_writew(epio, MUSB_TXCSR, csr);
1551 		}
1552 	} else {
1553 		csr = musb_readw(epio, MUSB_RXCSR);
1554 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1555 		musb_writew(epio, MUSB_RXCSR, csr);
1556 		musb_writew(epio, MUSB_RXCSR, csr);
1557 	}
1558 
1559 	/* re-enable interrupt */
1560 	musb_writew(mbase, MUSB_INTRTXE, int_txe);
1561 	spin_unlock_irqrestore(&musb->lock, flags);
1562 }
1563 
1564 static const struct usb_ep_ops musb_ep_ops = {
1565 	.enable		= musb_gadget_enable,
1566 	.disable	= musb_gadget_disable,
1567 	.alloc_request	= musb_alloc_request,
1568 	.free_request	= musb_free_request,
1569 	.queue		= musb_gadget_queue,
1570 	.dequeue	= musb_gadget_dequeue,
1571 	.set_halt	= musb_gadget_set_halt,
1572 	.set_wedge	= musb_gadget_set_wedge,
1573 	.fifo_status	= musb_gadget_fifo_status,
1574 	.fifo_flush	= musb_gadget_fifo_flush
1575 };
1576 
1577 /* ----------------------------------------------------------------------- */
1578 
1579 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1580 {
1581 	struct musb	*musb = gadget_to_musb(gadget);
1582 
1583 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1584 }
1585 
1586 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1587 {
1588 	struct musb	*musb = gadget_to_musb(gadget);
1589 	void __iomem	*mregs = musb->mregs;
1590 	unsigned long	flags;
1591 	int		status = -EINVAL;
1592 	u8		power, devctl;
1593 	int		retries;
1594 
1595 	spin_lock_irqsave(&musb->lock, flags);
1596 
1597 	switch (musb->xceiv->state) {
1598 	case OTG_STATE_B_PERIPHERAL:
1599 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1600 		 * that's part of the standard usb 1.1 state machine, and
1601 		 * doesn't affect OTG transitions.
1602 		 */
1603 		if (musb->may_wakeup && musb->is_suspended)
1604 			break;
1605 		goto done;
1606 	case OTG_STATE_B_IDLE:
1607 		/* Start SRP ... OTG not required. */
1608 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1609 		dev_dbg(musb->controller, "Sending SRP: devctl: %02x\n", devctl);
1610 		devctl |= MUSB_DEVCTL_SESSION;
1611 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1612 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1613 		retries = 100;
1614 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1615 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1616 			if (retries-- < 1)
1617 				break;
1618 		}
1619 		retries = 10000;
1620 		while (devctl & MUSB_DEVCTL_SESSION) {
1621 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1622 			if (retries-- < 1)
1623 				break;
1624 		}
1625 
1626 		spin_unlock_irqrestore(&musb->lock, flags);
1627 		otg_start_srp(musb->xceiv);
1628 		spin_lock_irqsave(&musb->lock, flags);
1629 
1630 		/* Block idling for at least 1s */
1631 		musb_platform_try_idle(musb,
1632 			jiffies + msecs_to_jiffies(1 * HZ));
1633 
1634 		status = 0;
1635 		goto done;
1636 	default:
1637 		dev_dbg(musb->controller, "Unhandled wake: %s\n",
1638 			otg_state_string(musb->xceiv->state));
1639 		goto done;
1640 	}
1641 
1642 	status = 0;
1643 
1644 	power = musb_readb(mregs, MUSB_POWER);
1645 	power |= MUSB_POWER_RESUME;
1646 	musb_writeb(mregs, MUSB_POWER, power);
1647 	dev_dbg(musb->controller, "issue wakeup\n");
1648 
1649 	/* FIXME do this next chunk in a timer callback, no udelay */
1650 	mdelay(2);
1651 
1652 	power = musb_readb(mregs, MUSB_POWER);
1653 	power &= ~MUSB_POWER_RESUME;
1654 	musb_writeb(mregs, MUSB_POWER, power);
1655 done:
1656 	spin_unlock_irqrestore(&musb->lock, flags);
1657 	return status;
1658 }
1659 
1660 static int
1661 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1662 {
1663 	struct musb	*musb = gadget_to_musb(gadget);
1664 
1665 	musb->is_self_powered = !!is_selfpowered;
1666 	return 0;
1667 }
1668 
1669 static void musb_pullup(struct musb *musb, int is_on)
1670 {
1671 	u8 power;
1672 
1673 	power = musb_readb(musb->mregs, MUSB_POWER);
1674 	if (is_on)
1675 		power |= MUSB_POWER_SOFTCONN;
1676 	else
1677 		power &= ~MUSB_POWER_SOFTCONN;
1678 
1679 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1680 
1681 	dev_dbg(musb->controller, "gadget D+ pullup %s\n",
1682 		is_on ? "on" : "off");
1683 	musb_writeb(musb->mregs, MUSB_POWER, power);
1684 }
1685 
1686 #if 0
1687 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1688 {
1689 	dev_dbg(musb->controller, "<= %s =>\n", __func__);
1690 
1691 	/*
1692 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1693 	 * though that can clear it), just musb_pullup().
1694 	 */
1695 
1696 	return -EINVAL;
1697 }
1698 #endif
1699 
1700 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1701 {
1702 	struct musb	*musb = gadget_to_musb(gadget);
1703 
1704 	if (!musb->xceiv->set_power)
1705 		return -EOPNOTSUPP;
1706 	return otg_set_power(musb->xceiv, mA);
1707 }
1708 
1709 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1710 {
1711 	struct musb	*musb = gadget_to_musb(gadget);
1712 	unsigned long	flags;
1713 
1714 	is_on = !!is_on;
1715 
1716 	pm_runtime_get_sync(musb->controller);
1717 
1718 	/* NOTE: this assumes we are sensing vbus; we'd rather
1719 	 * not pullup unless the B-session is active.
1720 	 */
1721 	spin_lock_irqsave(&musb->lock, flags);
1722 	if (is_on != musb->softconnect) {
1723 		musb->softconnect = is_on;
1724 		musb_pullup(musb, is_on);
1725 	}
1726 	spin_unlock_irqrestore(&musb->lock, flags);
1727 
1728 	pm_runtime_put(musb->controller);
1729 
1730 	return 0;
1731 }
1732 
1733 static int musb_gadget_start(struct usb_gadget *g,
1734 		struct usb_gadget_driver *driver);
1735 static int musb_gadget_stop(struct usb_gadget *g,
1736 		struct usb_gadget_driver *driver);
1737 
1738 static const struct usb_gadget_ops musb_gadget_operations = {
1739 	.get_frame		= musb_gadget_get_frame,
1740 	.wakeup			= musb_gadget_wakeup,
1741 	.set_selfpowered	= musb_gadget_set_self_powered,
1742 	/* .vbus_session		= musb_gadget_vbus_session, */
1743 	.vbus_draw		= musb_gadget_vbus_draw,
1744 	.pullup			= musb_gadget_pullup,
1745 	.udc_start		= musb_gadget_start,
1746 	.udc_stop		= musb_gadget_stop,
1747 };
1748 
1749 /* ----------------------------------------------------------------------- */
1750 
1751 /* Registration */
1752 
1753 /* Only this registration code "knows" the rule (from USB standards)
1754  * about there being only one external upstream port.  It assumes
1755  * all peripheral ports are external...
1756  */
1757 
1758 static void musb_gadget_release(struct device *dev)
1759 {
1760 	/* kref_put(WHAT) */
1761 	dev_dbg(dev, "%s\n", __func__);
1762 }
1763 
1764 
1765 static void __init
1766 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1767 {
1768 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1769 
1770 	memset(ep, 0, sizeof *ep);
1771 
1772 	ep->current_epnum = epnum;
1773 	ep->musb = musb;
1774 	ep->hw_ep = hw_ep;
1775 	ep->is_in = is_in;
1776 
1777 	INIT_LIST_HEAD(&ep->req_list);
1778 
1779 	sprintf(ep->name, "ep%d%s", epnum,
1780 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1781 				is_in ? "in" : "out"));
1782 	ep->end_point.name = ep->name;
1783 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1784 	if (!epnum) {
1785 		ep->end_point.maxpacket = 64;
1786 		ep->end_point.ops = &musb_g_ep0_ops;
1787 		musb->g.ep0 = &ep->end_point;
1788 	} else {
1789 		if (is_in)
1790 			ep->end_point.maxpacket = hw_ep->max_packet_sz_tx;
1791 		else
1792 			ep->end_point.maxpacket = hw_ep->max_packet_sz_rx;
1793 		ep->end_point.ops = &musb_ep_ops;
1794 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1795 	}
1796 }
1797 
1798 /*
1799  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1800  * to the rest of the driver state.
1801  */
1802 static inline void __init musb_g_init_endpoints(struct musb *musb)
1803 {
1804 	u8			epnum;
1805 	struct musb_hw_ep	*hw_ep;
1806 	unsigned		count = 0;
1807 
1808 	/* initialize endpoint list just once */
1809 	INIT_LIST_HEAD(&(musb->g.ep_list));
1810 
1811 	for (epnum = 0, hw_ep = musb->endpoints;
1812 			epnum < musb->nr_endpoints;
1813 			epnum++, hw_ep++) {
1814 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1815 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1816 			count++;
1817 		} else {
1818 			if (hw_ep->max_packet_sz_tx) {
1819 				init_peripheral_ep(musb, &hw_ep->ep_in,
1820 							epnum, 1);
1821 				count++;
1822 			}
1823 			if (hw_ep->max_packet_sz_rx) {
1824 				init_peripheral_ep(musb, &hw_ep->ep_out,
1825 							epnum, 0);
1826 				count++;
1827 			}
1828 		}
1829 	}
1830 }
1831 
1832 /* called once during driver setup to initialize and link into
1833  * the driver model; memory is zeroed.
1834  */
1835 int __init musb_gadget_setup(struct musb *musb)
1836 {
1837 	int status;
1838 
1839 	/* REVISIT minor race:  if (erroneously) setting up two
1840 	 * musb peripherals at the same time, only the bus lock
1841 	 * is probably held.
1842 	 */
1843 
1844 	musb->g.ops = &musb_gadget_operations;
1845 	musb->g.max_speed = USB_SPEED_HIGH;
1846 	musb->g.speed = USB_SPEED_UNKNOWN;
1847 
1848 	/* this "gadget" abstracts/virtualizes the controller */
1849 	dev_set_name(&musb->g.dev, "gadget");
1850 	musb->g.dev.parent = musb->controller;
1851 	musb->g.dev.dma_mask = musb->controller->dma_mask;
1852 	musb->g.dev.release = musb_gadget_release;
1853 	musb->g.name = musb_driver_name;
1854 
1855 	if (is_otg_enabled(musb))
1856 		musb->g.is_otg = 1;
1857 
1858 	musb_g_init_endpoints(musb);
1859 
1860 	musb->is_active = 0;
1861 	musb_platform_try_idle(musb, 0);
1862 
1863 	status = device_register(&musb->g.dev);
1864 	if (status != 0) {
1865 		put_device(&musb->g.dev);
1866 		return status;
1867 	}
1868 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1869 	if (status)
1870 		goto err;
1871 
1872 	return 0;
1873 err:
1874 	musb->g.dev.parent = NULL;
1875 	device_unregister(&musb->g.dev);
1876 	return status;
1877 }
1878 
1879 void musb_gadget_cleanup(struct musb *musb)
1880 {
1881 	usb_del_gadget_udc(&musb->g);
1882 	if (musb->g.dev.parent)
1883 		device_unregister(&musb->g.dev);
1884 }
1885 
1886 /*
1887  * Register the gadget driver. Used by gadget drivers when
1888  * registering themselves with the controller.
1889  *
1890  * -EINVAL something went wrong (not driver)
1891  * -EBUSY another gadget is already using the controller
1892  * -ENOMEM no memory to perform the operation
1893  *
1894  * @param driver the gadget driver
1895  * @return <0 if error, 0 if everything is fine
1896  */
1897 static int musb_gadget_start(struct usb_gadget *g,
1898 		struct usb_gadget_driver *driver)
1899 {
1900 	struct musb		*musb = gadget_to_musb(g);
1901 	unsigned long		flags;
1902 	int			retval = -EINVAL;
1903 
1904 	if (driver->max_speed < USB_SPEED_HIGH)
1905 		goto err0;
1906 
1907 	pm_runtime_get_sync(musb->controller);
1908 
1909 	dev_dbg(musb->controller, "registering driver %s\n", driver->function);
1910 
1911 	musb->softconnect = 0;
1912 	musb->gadget_driver = driver;
1913 
1914 	spin_lock_irqsave(&musb->lock, flags);
1915 	musb->is_active = 1;
1916 
1917 	otg_set_peripheral(musb->xceiv, &musb->g);
1918 	musb->xceiv->state = OTG_STATE_B_IDLE;
1919 
1920 	/*
1921 	 * FIXME this ignores the softconnect flag.  Drivers are
1922 	 * allowed hold the peripheral inactive until for example
1923 	 * userspace hooks up printer hardware or DSP codecs, so
1924 	 * hosts only see fully functional devices.
1925 	 */
1926 
1927 	if (!is_otg_enabled(musb))
1928 		musb_start(musb);
1929 
1930 	spin_unlock_irqrestore(&musb->lock, flags);
1931 
1932 	if (is_otg_enabled(musb)) {
1933 		struct usb_hcd	*hcd = musb_to_hcd(musb);
1934 
1935 		dev_dbg(musb->controller, "OTG startup...\n");
1936 
1937 		/* REVISIT:  funcall to other code, which also
1938 		 * handles power budgeting ... this way also
1939 		 * ensures HdrcStart is indirectly called.
1940 		 */
1941 		retval = usb_add_hcd(musb_to_hcd(musb), -1, 0);
1942 		if (retval < 0) {
1943 			dev_dbg(musb->controller, "add_hcd failed, %d\n", retval);
1944 			goto err2;
1945 		}
1946 
1947 		if ((musb->xceiv->last_event == USB_EVENT_ID)
1948 					&& musb->xceiv->set_vbus)
1949 			otg_set_vbus(musb->xceiv, 1);
1950 
1951 		hcd->self.uses_pio_for_control = 1;
1952 	}
1953 	if (musb->xceiv->last_event == USB_EVENT_NONE)
1954 		pm_runtime_put(musb->controller);
1955 
1956 	return 0;
1957 
1958 err2:
1959 	if (!is_otg_enabled(musb))
1960 		musb_stop(musb);
1961 err0:
1962 	return retval;
1963 }
1964 
1965 static void stop_activity(struct musb *musb, struct usb_gadget_driver *driver)
1966 {
1967 	int			i;
1968 	struct musb_hw_ep	*hw_ep;
1969 
1970 	/* don't disconnect if it's not connected */
1971 	if (musb->g.speed == USB_SPEED_UNKNOWN)
1972 		driver = NULL;
1973 	else
1974 		musb->g.speed = USB_SPEED_UNKNOWN;
1975 
1976 	/* deactivate the hardware */
1977 	if (musb->softconnect) {
1978 		musb->softconnect = 0;
1979 		musb_pullup(musb, 0);
1980 	}
1981 	musb_stop(musb);
1982 
1983 	/* killing any outstanding requests will quiesce the driver;
1984 	 * then report disconnect
1985 	 */
1986 	if (driver) {
1987 		for (i = 0, hw_ep = musb->endpoints;
1988 				i < musb->nr_endpoints;
1989 				i++, hw_ep++) {
1990 			musb_ep_select(musb->mregs, i);
1991 			if (hw_ep->is_shared_fifo /* || !epnum */) {
1992 				nuke(&hw_ep->ep_in, -ESHUTDOWN);
1993 			} else {
1994 				if (hw_ep->max_packet_sz_tx)
1995 					nuke(&hw_ep->ep_in, -ESHUTDOWN);
1996 				if (hw_ep->max_packet_sz_rx)
1997 					nuke(&hw_ep->ep_out, -ESHUTDOWN);
1998 			}
1999 		}
2000 	}
2001 }
2002 
2003 /*
2004  * Unregister the gadget driver. Used by gadget drivers when
2005  * unregistering themselves from the controller.
2006  *
2007  * @param driver the gadget driver to unregister
2008  */
2009 static int musb_gadget_stop(struct usb_gadget *g,
2010 		struct usb_gadget_driver *driver)
2011 {
2012 	struct musb	*musb = gadget_to_musb(g);
2013 	unsigned long	flags;
2014 
2015 	if (musb->xceiv->last_event == USB_EVENT_NONE)
2016 		pm_runtime_get_sync(musb->controller);
2017 
2018 	/*
2019 	 * REVISIT always use otg_set_peripheral() here too;
2020 	 * this needs to shut down the OTG engine.
2021 	 */
2022 
2023 	spin_lock_irqsave(&musb->lock, flags);
2024 
2025 	musb_hnp_stop(musb);
2026 
2027 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2028 
2029 	musb->xceiv->state = OTG_STATE_UNDEFINED;
2030 	stop_activity(musb, driver);
2031 	otg_set_peripheral(musb->xceiv, NULL);
2032 
2033 	dev_dbg(musb->controller, "unregistering driver %s\n", driver->function);
2034 
2035 	musb->is_active = 0;
2036 	musb_platform_try_idle(musb, 0);
2037 	spin_unlock_irqrestore(&musb->lock, flags);
2038 
2039 	if (is_otg_enabled(musb)) {
2040 		usb_remove_hcd(musb_to_hcd(musb));
2041 		/* FIXME we need to be able to register another
2042 		 * gadget driver here and have everything work;
2043 		 * that currently misbehaves.
2044 		 */
2045 	}
2046 
2047 	if (!is_otg_enabled(musb))
2048 		musb_stop(musb);
2049 
2050 	pm_runtime_put(musb->controller);
2051 
2052 	return 0;
2053 }
2054 
2055 /* ----------------------------------------------------------------------- */
2056 
2057 /* lifecycle operations called through plat_uds.c */
2058 
2059 void musb_g_resume(struct musb *musb)
2060 {
2061 	musb->is_suspended = 0;
2062 	switch (musb->xceiv->state) {
2063 	case OTG_STATE_B_IDLE:
2064 		break;
2065 	case OTG_STATE_B_WAIT_ACON:
2066 	case OTG_STATE_B_PERIPHERAL:
2067 		musb->is_active = 1;
2068 		if (musb->gadget_driver && musb->gadget_driver->resume) {
2069 			spin_unlock(&musb->lock);
2070 			musb->gadget_driver->resume(&musb->g);
2071 			spin_lock(&musb->lock);
2072 		}
2073 		break;
2074 	default:
2075 		WARNING("unhandled RESUME transition (%s)\n",
2076 				otg_state_string(musb->xceiv->state));
2077 	}
2078 }
2079 
2080 /* called when SOF packets stop for 3+ msec */
2081 void musb_g_suspend(struct musb *musb)
2082 {
2083 	u8	devctl;
2084 
2085 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2086 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2087 
2088 	switch (musb->xceiv->state) {
2089 	case OTG_STATE_B_IDLE:
2090 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2091 			musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2092 		break;
2093 	case OTG_STATE_B_PERIPHERAL:
2094 		musb->is_suspended = 1;
2095 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
2096 			spin_unlock(&musb->lock);
2097 			musb->gadget_driver->suspend(&musb->g);
2098 			spin_lock(&musb->lock);
2099 		}
2100 		break;
2101 	default:
2102 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
2103 		 * A_PERIPHERAL may need care too
2104 		 */
2105 		WARNING("unhandled SUSPEND transition (%s)\n",
2106 				otg_state_string(musb->xceiv->state));
2107 	}
2108 }
2109 
2110 /* Called during SRP */
2111 void musb_g_wakeup(struct musb *musb)
2112 {
2113 	musb_gadget_wakeup(&musb->g);
2114 }
2115 
2116 /* called when VBUS drops below session threshold, and in other cases */
2117 void musb_g_disconnect(struct musb *musb)
2118 {
2119 	void __iomem	*mregs = musb->mregs;
2120 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
2121 
2122 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2123 
2124 	/* clear HR */
2125 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
2126 
2127 	/* don't draw vbus until new b-default session */
2128 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2129 
2130 	musb->g.speed = USB_SPEED_UNKNOWN;
2131 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
2132 		spin_unlock(&musb->lock);
2133 		musb->gadget_driver->disconnect(&musb->g);
2134 		spin_lock(&musb->lock);
2135 	}
2136 
2137 	switch (musb->xceiv->state) {
2138 	default:
2139 		dev_dbg(musb->controller, "Unhandled disconnect %s, setting a_idle\n",
2140 			otg_state_string(musb->xceiv->state));
2141 		musb->xceiv->state = OTG_STATE_A_IDLE;
2142 		MUSB_HST_MODE(musb);
2143 		break;
2144 	case OTG_STATE_A_PERIPHERAL:
2145 		musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2146 		MUSB_HST_MODE(musb);
2147 		break;
2148 	case OTG_STATE_B_WAIT_ACON:
2149 	case OTG_STATE_B_HOST:
2150 	case OTG_STATE_B_PERIPHERAL:
2151 	case OTG_STATE_B_IDLE:
2152 		musb->xceiv->state = OTG_STATE_B_IDLE;
2153 		break;
2154 	case OTG_STATE_B_SRP_INIT:
2155 		break;
2156 	}
2157 
2158 	musb->is_active = 0;
2159 }
2160 
2161 void musb_g_reset(struct musb *musb)
2162 __releases(musb->lock)
2163 __acquires(musb->lock)
2164 {
2165 	void __iomem	*mbase = musb->mregs;
2166 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2167 	u8		power;
2168 
2169 	dev_dbg(musb->controller, "<== %s addr=%x driver '%s'\n",
2170 			(devctl & MUSB_DEVCTL_BDEVICE)
2171 				? "B-Device" : "A-Device",
2172 			musb_readb(mbase, MUSB_FADDR),
2173 			musb->gadget_driver
2174 				? musb->gadget_driver->driver.name
2175 				: NULL
2176 			);
2177 
2178 	/* report disconnect, if we didn't already (flushing EP state) */
2179 	if (musb->g.speed != USB_SPEED_UNKNOWN)
2180 		musb_g_disconnect(musb);
2181 
2182 	/* clear HR */
2183 	else if (devctl & MUSB_DEVCTL_HR)
2184 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2185 
2186 
2187 	/* what speed did we negotiate? */
2188 	power = musb_readb(mbase, MUSB_POWER);
2189 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2190 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2191 
2192 	/* start in USB_STATE_DEFAULT */
2193 	musb->is_active = 1;
2194 	musb->is_suspended = 0;
2195 	MUSB_DEV_MODE(musb);
2196 	musb->address = 0;
2197 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2198 
2199 	musb->may_wakeup = 0;
2200 	musb->g.b_hnp_enable = 0;
2201 	musb->g.a_alt_hnp_support = 0;
2202 	musb->g.a_hnp_support = 0;
2203 
2204 	/* Normal reset, as B-Device;
2205 	 * or else after HNP, as A-Device
2206 	 */
2207 	if (devctl & MUSB_DEVCTL_BDEVICE) {
2208 		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2209 		musb->g.is_a_peripheral = 0;
2210 	} else if (is_otg_enabled(musb)) {
2211 		musb->xceiv->state = OTG_STATE_A_PERIPHERAL;
2212 		musb->g.is_a_peripheral = 1;
2213 	} else
2214 		WARN_ON(1);
2215 
2216 	/* start with default limits on VBUS power draw */
2217 	(void) musb_gadget_vbus_draw(&musb->g,
2218 			is_otg_enabled(musb) ? 8 : 100);
2219 }
2220