xref: /openbmc/linux/drivers/usb/musb/musb_gadget.c (revision 81d67439)
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 
638 	if (hw_ep->is_shared_fifo)
639 		musb_ep = &hw_ep->ep_in;
640 	else
641 		musb_ep = &hw_ep->ep_out;
642 
643 	len = musb_ep->packet_sz;
644 
645 	/* We shouldn't get here while DMA is active, but we do... */
646 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
647 		dev_dbg(musb->controller, "DMA pending...\n");
648 		return;
649 	}
650 
651 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
652 		dev_dbg(musb->controller, "%s stalling, RXCSR %04x\n",
653 		    musb_ep->end_point.name, csr);
654 		return;
655 	}
656 
657 	if (is_cppi_enabled() && is_buffer_mapped(req)) {
658 		struct dma_controller	*c = musb->dma_controller;
659 		struct dma_channel	*channel = musb_ep->dma;
660 
661 		/* NOTE:  CPPI won't actually stop advancing the DMA
662 		 * queue after short packet transfers, so this is almost
663 		 * always going to run as IRQ-per-packet DMA so that
664 		 * faults will be handled correctly.
665 		 */
666 		if (c->channel_program(channel,
667 				musb_ep->packet_sz,
668 				!request->short_not_ok,
669 				request->dma + request->actual,
670 				request->length - request->actual)) {
671 
672 			/* make sure that if an rxpkt arrived after the irq,
673 			 * the cppi engine will be ready to take it as soon
674 			 * as DMA is enabled
675 			 */
676 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
677 					| MUSB_RXCSR_DMAMODE);
678 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
679 			musb_writew(epio, MUSB_RXCSR, csr);
680 			return;
681 		}
682 	}
683 
684 	if (csr & MUSB_RXCSR_RXPKTRDY) {
685 		len = musb_readw(epio, MUSB_RXCOUNT);
686 		if (request->actual < request->length) {
687 #ifdef CONFIG_USB_INVENTRA_DMA
688 			if (is_buffer_mapped(req)) {
689 				struct dma_controller	*c;
690 				struct dma_channel	*channel;
691 				int			use_dma = 0;
692 
693 				c = musb->dma_controller;
694 				channel = musb_ep->dma;
695 
696 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
697 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
698 	 * completion. We only get interrupts from DMA controller.
699 	 *
700 	 * We could operate in DMA mode 1 if we knew the size of the tranfer
701 	 * in advance. For mass storage class, request->length = what the host
702 	 * sends, so that'd work.  But for pretty much everything else,
703 	 * request->length is routinely more than what the host sends. For
704 	 * most these gadgets, end of is signified either by a short packet,
705 	 * or filling the last byte of the buffer.  (Sending extra data in
706 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
707 	 * we don't get DMA completion interrrupt for short packets.
708 	 *
709 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
710 	 * to get endpoint interrupt on every DMA req, but that didn't seem
711 	 * to work reliably.
712 	 *
713 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
714 	 * then becomes usable as a runtime "use mode 1" hint...
715 	 */
716 
717 				csr |= MUSB_RXCSR_DMAENAB;
718 #ifdef USE_MODE1
719 				csr |= MUSB_RXCSR_AUTOCLEAR;
720 				/* csr |= MUSB_RXCSR_DMAMODE; */
721 
722 				/* this special sequence (enabling and then
723 				 * disabling MUSB_RXCSR_DMAMODE) is required
724 				 * to get DMAReq to activate
725 				 */
726 				musb_writew(epio, MUSB_RXCSR,
727 					csr | MUSB_RXCSR_DMAMODE);
728 #else
729 				if (!musb_ep->hb_mult &&
730 					musb_ep->hw_ep->rx_double_buffered)
731 					csr |= MUSB_RXCSR_AUTOCLEAR;
732 #endif
733 				musb_writew(epio, MUSB_RXCSR, csr);
734 
735 				if (request->actual < request->length) {
736 					int transfer_size = 0;
737 #ifdef USE_MODE1
738 					transfer_size = min(request->length - request->actual,
739 							channel->max_len);
740 #else
741 					transfer_size = min(request->length - request->actual,
742 							(unsigned)len);
743 #endif
744 					if (transfer_size <= musb_ep->packet_sz)
745 						musb_ep->dma->desired_mode = 0;
746 					else
747 						musb_ep->dma->desired_mode = 1;
748 
749 					use_dma = c->channel_program(
750 							channel,
751 							musb_ep->packet_sz,
752 							channel->desired_mode,
753 							request->dma
754 							+ request->actual,
755 							transfer_size);
756 				}
757 
758 				if (use_dma)
759 					return;
760 			}
761 #elif defined(CONFIG_USB_UX500_DMA)
762 			if ((is_buffer_mapped(req)) &&
763 				(request->actual < request->length)) {
764 
765 				struct dma_controller *c;
766 				struct dma_channel *channel;
767 				int transfer_size = 0;
768 
769 				c = musb->dma_controller;
770 				channel = musb_ep->dma;
771 
772 				/* In case first packet is short */
773 				if (len < musb_ep->packet_sz)
774 					transfer_size = len;
775 				else if (request->short_not_ok)
776 					transfer_size =	min(request->length -
777 							request->actual,
778 							channel->max_len);
779 				else
780 					transfer_size = min(request->length -
781 							request->actual,
782 							(unsigned)len);
783 
784 				csr &= ~MUSB_RXCSR_DMAMODE;
785 				csr |= (MUSB_RXCSR_DMAENAB |
786 					MUSB_RXCSR_AUTOCLEAR);
787 
788 				musb_writew(epio, MUSB_RXCSR, csr);
789 
790 				if (transfer_size <= musb_ep->packet_sz) {
791 					musb_ep->dma->desired_mode = 0;
792 				} else {
793 					musb_ep->dma->desired_mode = 1;
794 					/* Mode must be set after DMAENAB */
795 					csr |= MUSB_RXCSR_DMAMODE;
796 					musb_writew(epio, MUSB_RXCSR, csr);
797 				}
798 
799 				if (c->channel_program(channel,
800 							musb_ep->packet_sz,
801 							channel->desired_mode,
802 							request->dma
803 							+ request->actual,
804 							transfer_size))
805 
806 					return;
807 			}
808 #endif	/* Mentor's DMA */
809 
810 			fifo_count = request->length - request->actual;
811 			dev_dbg(musb->controller, "%s OUT/RX pio fifo %d/%d, maxpacket %d\n",
812 					musb_ep->end_point.name,
813 					len, fifo_count,
814 					musb_ep->packet_sz);
815 
816 			fifo_count = min_t(unsigned, len, fifo_count);
817 
818 #ifdef	CONFIG_USB_TUSB_OMAP_DMA
819 			if (tusb_dma_omap() && is_buffer_mapped(req)) {
820 				struct dma_controller *c = musb->dma_controller;
821 				struct dma_channel *channel = musb_ep->dma;
822 				u32 dma_addr = request->dma + request->actual;
823 				int ret;
824 
825 				ret = c->channel_program(channel,
826 						musb_ep->packet_sz,
827 						channel->desired_mode,
828 						dma_addr,
829 						fifo_count);
830 				if (ret)
831 					return;
832 			}
833 #endif
834 			/*
835 			 * Unmap the dma buffer back to cpu if dma channel
836 			 * programming fails. This buffer is mapped if the
837 			 * channel allocation is successful
838 			 */
839 			 if (is_buffer_mapped(req)) {
840 				unmap_dma_buffer(req, musb);
841 
842 				/*
843 				 * Clear DMAENAB and AUTOCLEAR for the
844 				 * PIO mode transfer
845 				 */
846 				csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
847 				musb_writew(epio, MUSB_RXCSR, csr);
848 			}
849 
850 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
851 					(request->buf + request->actual));
852 			request->actual += fifo_count;
853 
854 			/* REVISIT if we left anything in the fifo, flush
855 			 * it and report -EOVERFLOW
856 			 */
857 
858 			/* ack the read! */
859 			csr |= MUSB_RXCSR_P_WZC_BITS;
860 			csr &= ~MUSB_RXCSR_RXPKTRDY;
861 			musb_writew(epio, MUSB_RXCSR, csr);
862 		}
863 	}
864 
865 	/* reach the end or short packet detected */
866 	if (request->actual == request->length || len < musb_ep->packet_sz)
867 		musb_g_giveback(musb_ep, request, 0);
868 }
869 
870 /*
871  * Data ready for a request; called from IRQ
872  */
873 void musb_g_rx(struct musb *musb, u8 epnum)
874 {
875 	u16			csr;
876 	struct musb_request	*req;
877 	struct usb_request	*request;
878 	void __iomem		*mbase = musb->mregs;
879 	struct musb_ep		*musb_ep;
880 	void __iomem		*epio = musb->endpoints[epnum].regs;
881 	struct dma_channel	*dma;
882 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
883 
884 	if (hw_ep->is_shared_fifo)
885 		musb_ep = &hw_ep->ep_in;
886 	else
887 		musb_ep = &hw_ep->ep_out;
888 
889 	musb_ep_select(mbase, epnum);
890 
891 	req = next_request(musb_ep);
892 	if (!req)
893 		return;
894 
895 	request = &req->request;
896 
897 	csr = musb_readw(epio, MUSB_RXCSR);
898 	dma = is_dma_capable() ? musb_ep->dma : NULL;
899 
900 	dev_dbg(musb->controller, "<== %s, rxcsr %04x%s %p\n", musb_ep->end_point.name,
901 			csr, dma ? " (dma)" : "", request);
902 
903 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
904 		csr |= MUSB_RXCSR_P_WZC_BITS;
905 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
906 		musb_writew(epio, MUSB_RXCSR, csr);
907 		return;
908 	}
909 
910 	if (csr & MUSB_RXCSR_P_OVERRUN) {
911 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
912 		csr &= ~MUSB_RXCSR_P_OVERRUN;
913 		musb_writew(epio, MUSB_RXCSR, csr);
914 
915 		dev_dbg(musb->controller, "%s iso overrun on %p\n", musb_ep->name, request);
916 		if (request->status == -EINPROGRESS)
917 			request->status = -EOVERFLOW;
918 	}
919 	if (csr & MUSB_RXCSR_INCOMPRX) {
920 		/* REVISIT not necessarily an error */
921 		dev_dbg(musb->controller, "%s, incomprx\n", musb_ep->end_point.name);
922 	}
923 
924 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
925 		/* "should not happen"; likely RXPKTRDY pending for DMA */
926 		dev_dbg(musb->controller, "%s busy, csr %04x\n",
927 			musb_ep->end_point.name, csr);
928 		return;
929 	}
930 
931 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
932 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
933 				| MUSB_RXCSR_DMAENAB
934 				| MUSB_RXCSR_DMAMODE);
935 		musb_writew(epio, MUSB_RXCSR,
936 			MUSB_RXCSR_P_WZC_BITS | csr);
937 
938 		request->actual += musb_ep->dma->actual_len;
939 
940 		dev_dbg(musb->controller, "RXCSR%d %04x, dma off, %04x, len %zu, req %p\n",
941 			epnum, csr,
942 			musb_readw(epio, MUSB_RXCSR),
943 			musb_ep->dma->actual_len, request);
944 
945 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
946 	defined(CONFIG_USB_UX500_DMA)
947 		/* Autoclear doesn't clear RxPktRdy for short packets */
948 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
949 				|| (dma->actual_len
950 					& (musb_ep->packet_sz - 1))) {
951 			/* ack the read! */
952 			csr &= ~MUSB_RXCSR_RXPKTRDY;
953 			musb_writew(epio, MUSB_RXCSR, csr);
954 		}
955 
956 		/* incomplete, and not short? wait for next IN packet */
957 		if ((request->actual < request->length)
958 				&& (musb_ep->dma->actual_len
959 					== musb_ep->packet_sz)) {
960 			/* In double buffer case, continue to unload fifo if
961  			 * there is Rx packet in FIFO.
962  			 **/
963 			csr = musb_readw(epio, MUSB_RXCSR);
964 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
965 				hw_ep->rx_double_buffered)
966 				goto exit;
967 			return;
968 		}
969 #endif
970 		musb_g_giveback(musb_ep, request, 0);
971 
972 		req = next_request(musb_ep);
973 		if (!req)
974 			return;
975 	}
976 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
977 	defined(CONFIG_USB_UX500_DMA)
978 exit:
979 #endif
980 	/* Analyze request */
981 	rxstate(musb, req);
982 }
983 
984 /* ------------------------------------------------------------ */
985 
986 static int musb_gadget_enable(struct usb_ep *ep,
987 			const struct usb_endpoint_descriptor *desc)
988 {
989 	unsigned long		flags;
990 	struct musb_ep		*musb_ep;
991 	struct musb_hw_ep	*hw_ep;
992 	void __iomem		*regs;
993 	struct musb		*musb;
994 	void __iomem	*mbase;
995 	u8		epnum;
996 	u16		csr;
997 	unsigned	tmp;
998 	int		status = -EINVAL;
999 
1000 	if (!ep || !desc)
1001 		return -EINVAL;
1002 
1003 	musb_ep = to_musb_ep(ep);
1004 	hw_ep = musb_ep->hw_ep;
1005 	regs = hw_ep->regs;
1006 	musb = musb_ep->musb;
1007 	mbase = musb->mregs;
1008 	epnum = musb_ep->current_epnum;
1009 
1010 	spin_lock_irqsave(&musb->lock, flags);
1011 
1012 	if (musb_ep->desc) {
1013 		status = -EBUSY;
1014 		goto fail;
1015 	}
1016 	musb_ep->type = usb_endpoint_type(desc);
1017 
1018 	/* check direction and (later) maxpacket size against endpoint */
1019 	if (usb_endpoint_num(desc) != epnum)
1020 		goto fail;
1021 
1022 	/* REVISIT this rules out high bandwidth periodic transfers */
1023 	tmp = le16_to_cpu(desc->wMaxPacketSize);
1024 	if (tmp & ~0x07ff) {
1025 		int ok;
1026 
1027 		if (usb_endpoint_dir_in(desc))
1028 			ok = musb->hb_iso_tx;
1029 		else
1030 			ok = musb->hb_iso_rx;
1031 
1032 		if (!ok) {
1033 			dev_dbg(musb->controller, "no support for high bandwidth ISO\n");
1034 			goto fail;
1035 		}
1036 		musb_ep->hb_mult = (tmp >> 11) & 3;
1037 	} else {
1038 		musb_ep->hb_mult = 0;
1039 	}
1040 
1041 	musb_ep->packet_sz = tmp & 0x7ff;
1042 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
1043 
1044 	/* enable the interrupts for the endpoint, set the endpoint
1045 	 * packet size (or fail), set the mode, clear the fifo
1046 	 */
1047 	musb_ep_select(mbase, epnum);
1048 	if (usb_endpoint_dir_in(desc)) {
1049 		u16 int_txe = musb_readw(mbase, MUSB_INTRTXE);
1050 
1051 		if (hw_ep->is_shared_fifo)
1052 			musb_ep->is_in = 1;
1053 		if (!musb_ep->is_in)
1054 			goto fail;
1055 
1056 		if (tmp > hw_ep->max_packet_sz_tx) {
1057 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1058 			goto fail;
1059 		}
1060 
1061 		int_txe |= (1 << epnum);
1062 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
1063 
1064 		/* REVISIT if can_bulk_split(), use by updating "tmp";
1065 		 * likewise high bandwidth periodic tx
1066 		 */
1067 		/* Set TXMAXP with the FIFO size of the endpoint
1068 		 * to disable double buffering mode.
1069 		 */
1070 		if (musb->double_buffer_not_ok)
1071 			musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
1072 		else
1073 			musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
1074 					| (musb_ep->hb_mult << 11));
1075 
1076 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
1077 		if (musb_readw(regs, MUSB_TXCSR)
1078 				& MUSB_TXCSR_FIFONOTEMPTY)
1079 			csr |= MUSB_TXCSR_FLUSHFIFO;
1080 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1081 			csr |= MUSB_TXCSR_P_ISO;
1082 
1083 		/* set twice in case of double buffering */
1084 		musb_writew(regs, MUSB_TXCSR, csr);
1085 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1086 		musb_writew(regs, MUSB_TXCSR, csr);
1087 
1088 	} else {
1089 		u16 int_rxe = musb_readw(mbase, MUSB_INTRRXE);
1090 
1091 		if (hw_ep->is_shared_fifo)
1092 			musb_ep->is_in = 0;
1093 		if (musb_ep->is_in)
1094 			goto fail;
1095 
1096 		if (tmp > hw_ep->max_packet_sz_rx) {
1097 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1098 			goto fail;
1099 		}
1100 
1101 		int_rxe |= (1 << epnum);
1102 		musb_writew(mbase, MUSB_INTRRXE, int_rxe);
1103 
1104 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1105 		 * likewise high bandwidth periodic rx
1106 		 */
1107 		/* Set RXMAXP with the FIFO size of the endpoint
1108 		 * to disable double buffering mode.
1109 		 */
1110 		if (musb->double_buffer_not_ok)
1111 			musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_tx);
1112 		else
1113 			musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1114 					| (musb_ep->hb_mult << 11));
1115 
1116 		/* force shared fifo to OUT-only mode */
1117 		if (hw_ep->is_shared_fifo) {
1118 			csr = musb_readw(regs, MUSB_TXCSR);
1119 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1120 			musb_writew(regs, MUSB_TXCSR, csr);
1121 		}
1122 
1123 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1124 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1125 			csr |= MUSB_RXCSR_P_ISO;
1126 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1127 			csr |= MUSB_RXCSR_DISNYET;
1128 
1129 		/* set twice in case of double buffering */
1130 		musb_writew(regs, MUSB_RXCSR, csr);
1131 		musb_writew(regs, MUSB_RXCSR, csr);
1132 	}
1133 
1134 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1135 	 * for some reason you run out of channels here.
1136 	 */
1137 	if (is_dma_capable() && musb->dma_controller) {
1138 		struct dma_controller	*c = musb->dma_controller;
1139 
1140 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1141 				(desc->bEndpointAddress & USB_DIR_IN));
1142 	} else
1143 		musb_ep->dma = NULL;
1144 
1145 	musb_ep->desc = desc;
1146 	musb_ep->busy = 0;
1147 	musb_ep->wedged = 0;
1148 	status = 0;
1149 
1150 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1151 			musb_driver_name, musb_ep->end_point.name,
1152 			({ char *s; switch (musb_ep->type) {
1153 			case USB_ENDPOINT_XFER_BULK:	s = "bulk"; break;
1154 			case USB_ENDPOINT_XFER_INT:	s = "int"; break;
1155 			default:			s = "iso"; break;
1156 			}; s; }),
1157 			musb_ep->is_in ? "IN" : "OUT",
1158 			musb_ep->dma ? "dma, " : "",
1159 			musb_ep->packet_sz);
1160 
1161 	schedule_work(&musb->irq_work);
1162 
1163 fail:
1164 	spin_unlock_irqrestore(&musb->lock, flags);
1165 	return status;
1166 }
1167 
1168 /*
1169  * Disable an endpoint flushing all requests queued.
1170  */
1171 static int musb_gadget_disable(struct usb_ep *ep)
1172 {
1173 	unsigned long	flags;
1174 	struct musb	*musb;
1175 	u8		epnum;
1176 	struct musb_ep	*musb_ep;
1177 	void __iomem	*epio;
1178 	int		status = 0;
1179 
1180 	musb_ep = to_musb_ep(ep);
1181 	musb = musb_ep->musb;
1182 	epnum = musb_ep->current_epnum;
1183 	epio = musb->endpoints[epnum].regs;
1184 
1185 	spin_lock_irqsave(&musb->lock, flags);
1186 	musb_ep_select(musb->mregs, epnum);
1187 
1188 	/* zero the endpoint sizes */
1189 	if (musb_ep->is_in) {
1190 		u16 int_txe = musb_readw(musb->mregs, MUSB_INTRTXE);
1191 		int_txe &= ~(1 << epnum);
1192 		musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
1193 		musb_writew(epio, MUSB_TXMAXP, 0);
1194 	} else {
1195 		u16 int_rxe = musb_readw(musb->mregs, MUSB_INTRRXE);
1196 		int_rxe &= ~(1 << epnum);
1197 		musb_writew(musb->mregs, MUSB_INTRRXE, int_rxe);
1198 		musb_writew(epio, MUSB_RXMAXP, 0);
1199 	}
1200 
1201 	musb_ep->desc = NULL;
1202 
1203 	/* abort all pending DMA and requests */
1204 	nuke(musb_ep, -ESHUTDOWN);
1205 
1206 	schedule_work(&musb->irq_work);
1207 
1208 	spin_unlock_irqrestore(&(musb->lock), flags);
1209 
1210 	dev_dbg(musb->controller, "%s\n", musb_ep->end_point.name);
1211 
1212 	return status;
1213 }
1214 
1215 /*
1216  * Allocate a request for an endpoint.
1217  * Reused by ep0 code.
1218  */
1219 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1220 {
1221 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1222 	struct musb		*musb = musb_ep->musb;
1223 	struct musb_request	*request = NULL;
1224 
1225 	request = kzalloc(sizeof *request, gfp_flags);
1226 	if (!request) {
1227 		dev_dbg(musb->controller, "not enough memory\n");
1228 		return NULL;
1229 	}
1230 
1231 	request->request.dma = DMA_ADDR_INVALID;
1232 	request->epnum = musb_ep->current_epnum;
1233 	request->ep = musb_ep;
1234 
1235 	return &request->request;
1236 }
1237 
1238 /*
1239  * Free a request
1240  * Reused by ep0 code.
1241  */
1242 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1243 {
1244 	kfree(to_musb_request(req));
1245 }
1246 
1247 static LIST_HEAD(buffers);
1248 
1249 struct free_record {
1250 	struct list_head	list;
1251 	struct device		*dev;
1252 	unsigned		bytes;
1253 	dma_addr_t		dma;
1254 };
1255 
1256 /*
1257  * Context: controller locked, IRQs blocked.
1258  */
1259 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1260 {
1261 	dev_dbg(musb->controller, "<== %s request %p len %u on hw_ep%d\n",
1262 		req->tx ? "TX/IN" : "RX/OUT",
1263 		&req->request, req->request.length, req->epnum);
1264 
1265 	musb_ep_select(musb->mregs, req->epnum);
1266 	if (req->tx)
1267 		txstate(musb, req);
1268 	else
1269 		rxstate(musb, req);
1270 }
1271 
1272 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1273 			gfp_t gfp_flags)
1274 {
1275 	struct musb_ep		*musb_ep;
1276 	struct musb_request	*request;
1277 	struct musb		*musb;
1278 	int			status = 0;
1279 	unsigned long		lockflags;
1280 
1281 	if (!ep || !req)
1282 		return -EINVAL;
1283 	if (!req->buf)
1284 		return -ENODATA;
1285 
1286 	musb_ep = to_musb_ep(ep);
1287 	musb = musb_ep->musb;
1288 
1289 	request = to_musb_request(req);
1290 	request->musb = musb;
1291 
1292 	if (request->ep != musb_ep)
1293 		return -EINVAL;
1294 
1295 	dev_dbg(musb->controller, "<== to %s request=%p\n", ep->name, req);
1296 
1297 	/* request is mine now... */
1298 	request->request.actual = 0;
1299 	request->request.status = -EINPROGRESS;
1300 	request->epnum = musb_ep->current_epnum;
1301 	request->tx = musb_ep->is_in;
1302 
1303 	map_dma_buffer(request, musb, musb_ep);
1304 
1305 	spin_lock_irqsave(&musb->lock, lockflags);
1306 
1307 	/* don't queue if the ep is down */
1308 	if (!musb_ep->desc) {
1309 		dev_dbg(musb->controller, "req %p queued to %s while ep %s\n",
1310 				req, ep->name, "disabled");
1311 		status = -ESHUTDOWN;
1312 		goto cleanup;
1313 	}
1314 
1315 	/* add request to the list */
1316 	list_add_tail(&request->list, &musb_ep->req_list);
1317 
1318 	/* it this is the head of the queue, start i/o ... */
1319 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next)
1320 		musb_ep_restart(musb, request);
1321 
1322 cleanup:
1323 	spin_unlock_irqrestore(&musb->lock, lockflags);
1324 	return status;
1325 }
1326 
1327 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1328 {
1329 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1330 	struct musb_request	*req = to_musb_request(request);
1331 	struct musb_request	*r;
1332 	unsigned long		flags;
1333 	int			status = 0;
1334 	struct musb		*musb = musb_ep->musb;
1335 
1336 	if (!ep || !request || to_musb_request(request)->ep != musb_ep)
1337 		return -EINVAL;
1338 
1339 	spin_lock_irqsave(&musb->lock, flags);
1340 
1341 	list_for_each_entry(r, &musb_ep->req_list, list) {
1342 		if (r == req)
1343 			break;
1344 	}
1345 	if (r != req) {
1346 		dev_dbg(musb->controller, "request %p not queued to %s\n", request, ep->name);
1347 		status = -EINVAL;
1348 		goto done;
1349 	}
1350 
1351 	/* if the hardware doesn't have the request, easy ... */
1352 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1353 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1354 
1355 	/* ... else abort the dma transfer ... */
1356 	else if (is_dma_capable() && musb_ep->dma) {
1357 		struct dma_controller	*c = musb->dma_controller;
1358 
1359 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1360 		if (c->channel_abort)
1361 			status = c->channel_abort(musb_ep->dma);
1362 		else
1363 			status = -EBUSY;
1364 		if (status == 0)
1365 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1366 	} else {
1367 		/* NOTE: by sticking to easily tested hardware/driver states,
1368 		 * we leave counting of in-flight packets imprecise.
1369 		 */
1370 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1371 	}
1372 
1373 done:
1374 	spin_unlock_irqrestore(&musb->lock, flags);
1375 	return status;
1376 }
1377 
1378 /*
1379  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1380  * data but will queue requests.
1381  *
1382  * exported to ep0 code
1383  */
1384 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1385 {
1386 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1387 	u8			epnum = musb_ep->current_epnum;
1388 	struct musb		*musb = musb_ep->musb;
1389 	void __iomem		*epio = musb->endpoints[epnum].regs;
1390 	void __iomem		*mbase;
1391 	unsigned long		flags;
1392 	u16			csr;
1393 	struct musb_request	*request;
1394 	int			status = 0;
1395 
1396 	if (!ep)
1397 		return -EINVAL;
1398 	mbase = musb->mregs;
1399 
1400 	spin_lock_irqsave(&musb->lock, flags);
1401 
1402 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1403 		status = -EINVAL;
1404 		goto done;
1405 	}
1406 
1407 	musb_ep_select(mbase, epnum);
1408 
1409 	request = next_request(musb_ep);
1410 	if (value) {
1411 		if (request) {
1412 			dev_dbg(musb->controller, "request in progress, cannot halt %s\n",
1413 			    ep->name);
1414 			status = -EAGAIN;
1415 			goto done;
1416 		}
1417 		/* Cannot portably stall with non-empty FIFO */
1418 		if (musb_ep->is_in) {
1419 			csr = musb_readw(epio, MUSB_TXCSR);
1420 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1421 				dev_dbg(musb->controller, "FIFO busy, cannot halt %s\n", ep->name);
1422 				status = -EAGAIN;
1423 				goto done;
1424 			}
1425 		}
1426 	} else
1427 		musb_ep->wedged = 0;
1428 
1429 	/* set/clear the stall and toggle bits */
1430 	dev_dbg(musb->controller, "%s: %s stall\n", ep->name, value ? "set" : "clear");
1431 	if (musb_ep->is_in) {
1432 		csr = musb_readw(epio, MUSB_TXCSR);
1433 		csr |= MUSB_TXCSR_P_WZC_BITS
1434 			| MUSB_TXCSR_CLRDATATOG;
1435 		if (value)
1436 			csr |= MUSB_TXCSR_P_SENDSTALL;
1437 		else
1438 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1439 				| MUSB_TXCSR_P_SENTSTALL);
1440 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1441 		musb_writew(epio, MUSB_TXCSR, csr);
1442 	} else {
1443 		csr = musb_readw(epio, MUSB_RXCSR);
1444 		csr |= MUSB_RXCSR_P_WZC_BITS
1445 			| MUSB_RXCSR_FLUSHFIFO
1446 			| MUSB_RXCSR_CLRDATATOG;
1447 		if (value)
1448 			csr |= MUSB_RXCSR_P_SENDSTALL;
1449 		else
1450 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1451 				| MUSB_RXCSR_P_SENTSTALL);
1452 		musb_writew(epio, MUSB_RXCSR, csr);
1453 	}
1454 
1455 	/* maybe start the first request in the queue */
1456 	if (!musb_ep->busy && !value && request) {
1457 		dev_dbg(musb->controller, "restarting the request\n");
1458 		musb_ep_restart(musb, request);
1459 	}
1460 
1461 done:
1462 	spin_unlock_irqrestore(&musb->lock, flags);
1463 	return status;
1464 }
1465 
1466 /*
1467  * Sets the halt feature with the clear requests ignored
1468  */
1469 static int musb_gadget_set_wedge(struct usb_ep *ep)
1470 {
1471 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1472 
1473 	if (!ep)
1474 		return -EINVAL;
1475 
1476 	musb_ep->wedged = 1;
1477 
1478 	return usb_ep_set_halt(ep);
1479 }
1480 
1481 static int musb_gadget_fifo_status(struct usb_ep *ep)
1482 {
1483 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1484 	void __iomem		*epio = musb_ep->hw_ep->regs;
1485 	int			retval = -EINVAL;
1486 
1487 	if (musb_ep->desc && !musb_ep->is_in) {
1488 		struct musb		*musb = musb_ep->musb;
1489 		int			epnum = musb_ep->current_epnum;
1490 		void __iomem		*mbase = musb->mregs;
1491 		unsigned long		flags;
1492 
1493 		spin_lock_irqsave(&musb->lock, flags);
1494 
1495 		musb_ep_select(mbase, epnum);
1496 		/* FIXME return zero unless RXPKTRDY is set */
1497 		retval = musb_readw(epio, MUSB_RXCOUNT);
1498 
1499 		spin_unlock_irqrestore(&musb->lock, flags);
1500 	}
1501 	return retval;
1502 }
1503 
1504 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1505 {
1506 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1507 	struct musb	*musb = musb_ep->musb;
1508 	u8		epnum = musb_ep->current_epnum;
1509 	void __iomem	*epio = musb->endpoints[epnum].regs;
1510 	void __iomem	*mbase;
1511 	unsigned long	flags;
1512 	u16		csr, int_txe;
1513 
1514 	mbase = musb->mregs;
1515 
1516 	spin_lock_irqsave(&musb->lock, flags);
1517 	musb_ep_select(mbase, (u8) epnum);
1518 
1519 	/* disable interrupts */
1520 	int_txe = musb_readw(mbase, MUSB_INTRTXE);
1521 	musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
1522 
1523 	if (musb_ep->is_in) {
1524 		csr = musb_readw(epio, MUSB_TXCSR);
1525 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1526 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1527 			/*
1528 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1529 			 * to interrupt current FIFO loading, but not flushing
1530 			 * the already loaded ones.
1531 			 */
1532 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1533 			musb_writew(epio, MUSB_TXCSR, csr);
1534 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1535 			musb_writew(epio, MUSB_TXCSR, csr);
1536 		}
1537 	} else {
1538 		csr = musb_readw(epio, MUSB_RXCSR);
1539 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1540 		musb_writew(epio, MUSB_RXCSR, csr);
1541 		musb_writew(epio, MUSB_RXCSR, csr);
1542 	}
1543 
1544 	/* re-enable interrupt */
1545 	musb_writew(mbase, MUSB_INTRTXE, int_txe);
1546 	spin_unlock_irqrestore(&musb->lock, flags);
1547 }
1548 
1549 static const struct usb_ep_ops musb_ep_ops = {
1550 	.enable		= musb_gadget_enable,
1551 	.disable	= musb_gadget_disable,
1552 	.alloc_request	= musb_alloc_request,
1553 	.free_request	= musb_free_request,
1554 	.queue		= musb_gadget_queue,
1555 	.dequeue	= musb_gadget_dequeue,
1556 	.set_halt	= musb_gadget_set_halt,
1557 	.set_wedge	= musb_gadget_set_wedge,
1558 	.fifo_status	= musb_gadget_fifo_status,
1559 	.fifo_flush	= musb_gadget_fifo_flush
1560 };
1561 
1562 /* ----------------------------------------------------------------------- */
1563 
1564 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1565 {
1566 	struct musb	*musb = gadget_to_musb(gadget);
1567 
1568 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1569 }
1570 
1571 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1572 {
1573 	struct musb	*musb = gadget_to_musb(gadget);
1574 	void __iomem	*mregs = musb->mregs;
1575 	unsigned long	flags;
1576 	int		status = -EINVAL;
1577 	u8		power, devctl;
1578 	int		retries;
1579 
1580 	spin_lock_irqsave(&musb->lock, flags);
1581 
1582 	switch (musb->xceiv->state) {
1583 	case OTG_STATE_B_PERIPHERAL:
1584 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1585 		 * that's part of the standard usb 1.1 state machine, and
1586 		 * doesn't affect OTG transitions.
1587 		 */
1588 		if (musb->may_wakeup && musb->is_suspended)
1589 			break;
1590 		goto done;
1591 	case OTG_STATE_B_IDLE:
1592 		/* Start SRP ... OTG not required. */
1593 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1594 		dev_dbg(musb->controller, "Sending SRP: devctl: %02x\n", devctl);
1595 		devctl |= MUSB_DEVCTL_SESSION;
1596 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1597 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1598 		retries = 100;
1599 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1600 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1601 			if (retries-- < 1)
1602 				break;
1603 		}
1604 		retries = 10000;
1605 		while (devctl & MUSB_DEVCTL_SESSION) {
1606 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1607 			if (retries-- < 1)
1608 				break;
1609 		}
1610 
1611 		spin_unlock_irqrestore(&musb->lock, flags);
1612 		otg_start_srp(musb->xceiv);
1613 		spin_lock_irqsave(&musb->lock, flags);
1614 
1615 		/* Block idling for at least 1s */
1616 		musb_platform_try_idle(musb,
1617 			jiffies + msecs_to_jiffies(1 * HZ));
1618 
1619 		status = 0;
1620 		goto done;
1621 	default:
1622 		dev_dbg(musb->controller, "Unhandled wake: %s\n",
1623 			otg_state_string(musb->xceiv->state));
1624 		goto done;
1625 	}
1626 
1627 	status = 0;
1628 
1629 	power = musb_readb(mregs, MUSB_POWER);
1630 	power |= MUSB_POWER_RESUME;
1631 	musb_writeb(mregs, MUSB_POWER, power);
1632 	dev_dbg(musb->controller, "issue wakeup\n");
1633 
1634 	/* FIXME do this next chunk in a timer callback, no udelay */
1635 	mdelay(2);
1636 
1637 	power = musb_readb(mregs, MUSB_POWER);
1638 	power &= ~MUSB_POWER_RESUME;
1639 	musb_writeb(mregs, MUSB_POWER, power);
1640 done:
1641 	spin_unlock_irqrestore(&musb->lock, flags);
1642 	return status;
1643 }
1644 
1645 static int
1646 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1647 {
1648 	struct musb	*musb = gadget_to_musb(gadget);
1649 
1650 	musb->is_self_powered = !!is_selfpowered;
1651 	return 0;
1652 }
1653 
1654 static void musb_pullup(struct musb *musb, int is_on)
1655 {
1656 	u8 power;
1657 
1658 	power = musb_readb(musb->mregs, MUSB_POWER);
1659 	if (is_on)
1660 		power |= MUSB_POWER_SOFTCONN;
1661 	else
1662 		power &= ~MUSB_POWER_SOFTCONN;
1663 
1664 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1665 
1666 	dev_dbg(musb->controller, "gadget %s D+ pullup %s\n",
1667 		musb->gadget_driver->function, is_on ? "on" : "off");
1668 	musb_writeb(musb->mregs, MUSB_POWER, power);
1669 }
1670 
1671 #if 0
1672 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1673 {
1674 	dev_dbg(musb->controller, "<= %s =>\n", __func__);
1675 
1676 	/*
1677 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1678 	 * though that can clear it), just musb_pullup().
1679 	 */
1680 
1681 	return -EINVAL;
1682 }
1683 #endif
1684 
1685 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1686 {
1687 	struct musb	*musb = gadget_to_musb(gadget);
1688 
1689 	if (!musb->xceiv->set_power)
1690 		return -EOPNOTSUPP;
1691 	return otg_set_power(musb->xceiv, mA);
1692 }
1693 
1694 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1695 {
1696 	struct musb	*musb = gadget_to_musb(gadget);
1697 	unsigned long	flags;
1698 
1699 	is_on = !!is_on;
1700 
1701 	/* NOTE: this assumes we are sensing vbus; we'd rather
1702 	 * not pullup unless the B-session is active.
1703 	 */
1704 	spin_lock_irqsave(&musb->lock, flags);
1705 	if (is_on != musb->softconnect) {
1706 		musb->softconnect = is_on;
1707 		musb_pullup(musb, is_on);
1708 	}
1709 	spin_unlock_irqrestore(&musb->lock, flags);
1710 	return 0;
1711 }
1712 
1713 static const struct usb_gadget_ops musb_gadget_operations = {
1714 	.get_frame		= musb_gadget_get_frame,
1715 	.wakeup			= musb_gadget_wakeup,
1716 	.set_selfpowered	= musb_gadget_set_self_powered,
1717 	/* .vbus_session		= musb_gadget_vbus_session, */
1718 	.vbus_draw		= musb_gadget_vbus_draw,
1719 	.pullup			= musb_gadget_pullup,
1720 };
1721 
1722 /* ----------------------------------------------------------------------- */
1723 
1724 /* Registration */
1725 
1726 /* Only this registration code "knows" the rule (from USB standards)
1727  * about there being only one external upstream port.  It assumes
1728  * all peripheral ports are external...
1729  */
1730 static struct musb *the_gadget;
1731 
1732 static void musb_gadget_release(struct device *dev)
1733 {
1734 	/* kref_put(WHAT) */
1735 	dev_dbg(dev, "%s\n", __func__);
1736 }
1737 
1738 
1739 static void __init
1740 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1741 {
1742 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1743 
1744 	memset(ep, 0, sizeof *ep);
1745 
1746 	ep->current_epnum = epnum;
1747 	ep->musb = musb;
1748 	ep->hw_ep = hw_ep;
1749 	ep->is_in = is_in;
1750 
1751 	INIT_LIST_HEAD(&ep->req_list);
1752 
1753 	sprintf(ep->name, "ep%d%s", epnum,
1754 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1755 				is_in ? "in" : "out"));
1756 	ep->end_point.name = ep->name;
1757 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1758 	if (!epnum) {
1759 		ep->end_point.maxpacket = 64;
1760 		ep->end_point.ops = &musb_g_ep0_ops;
1761 		musb->g.ep0 = &ep->end_point;
1762 	} else {
1763 		if (is_in)
1764 			ep->end_point.maxpacket = hw_ep->max_packet_sz_tx;
1765 		else
1766 			ep->end_point.maxpacket = hw_ep->max_packet_sz_rx;
1767 		ep->end_point.ops = &musb_ep_ops;
1768 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1769 	}
1770 }
1771 
1772 /*
1773  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1774  * to the rest of the driver state.
1775  */
1776 static inline void __init musb_g_init_endpoints(struct musb *musb)
1777 {
1778 	u8			epnum;
1779 	struct musb_hw_ep	*hw_ep;
1780 	unsigned		count = 0;
1781 
1782 	/* initialize endpoint list just once */
1783 	INIT_LIST_HEAD(&(musb->g.ep_list));
1784 
1785 	for (epnum = 0, hw_ep = musb->endpoints;
1786 			epnum < musb->nr_endpoints;
1787 			epnum++, hw_ep++) {
1788 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1789 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1790 			count++;
1791 		} else {
1792 			if (hw_ep->max_packet_sz_tx) {
1793 				init_peripheral_ep(musb, &hw_ep->ep_in,
1794 							epnum, 1);
1795 				count++;
1796 			}
1797 			if (hw_ep->max_packet_sz_rx) {
1798 				init_peripheral_ep(musb, &hw_ep->ep_out,
1799 							epnum, 0);
1800 				count++;
1801 			}
1802 		}
1803 	}
1804 }
1805 
1806 /* called once during driver setup to initialize and link into
1807  * the driver model; memory is zeroed.
1808  */
1809 int __init musb_gadget_setup(struct musb *musb)
1810 {
1811 	int status;
1812 
1813 	/* REVISIT minor race:  if (erroneously) setting up two
1814 	 * musb peripherals at the same time, only the bus lock
1815 	 * is probably held.
1816 	 */
1817 	if (the_gadget)
1818 		return -EBUSY;
1819 	the_gadget = musb;
1820 
1821 	musb->g.ops = &musb_gadget_operations;
1822 	musb->g.is_dualspeed = 1;
1823 	musb->g.speed = USB_SPEED_UNKNOWN;
1824 
1825 	/* this "gadget" abstracts/virtualizes the controller */
1826 	dev_set_name(&musb->g.dev, "gadget");
1827 	musb->g.dev.parent = musb->controller;
1828 	musb->g.dev.dma_mask = musb->controller->dma_mask;
1829 	musb->g.dev.release = musb_gadget_release;
1830 	musb->g.name = musb_driver_name;
1831 
1832 	if (is_otg_enabled(musb))
1833 		musb->g.is_otg = 1;
1834 
1835 	musb_g_init_endpoints(musb);
1836 
1837 	musb->is_active = 0;
1838 	musb_platform_try_idle(musb, 0);
1839 
1840 	status = device_register(&musb->g.dev);
1841 	if (status != 0) {
1842 		put_device(&musb->g.dev);
1843 		the_gadget = NULL;
1844 	}
1845 	return status;
1846 }
1847 
1848 void musb_gadget_cleanup(struct musb *musb)
1849 {
1850 	if (musb != the_gadget)
1851 		return;
1852 
1853 	device_unregister(&musb->g.dev);
1854 	the_gadget = NULL;
1855 }
1856 
1857 /*
1858  * Register the gadget driver. Used by gadget drivers when
1859  * registering themselves with the controller.
1860  *
1861  * -EINVAL something went wrong (not driver)
1862  * -EBUSY another gadget is already using the controller
1863  * -ENOMEM no memory to perform the operation
1864  *
1865  * @param driver the gadget driver
1866  * @param bind the driver's bind function
1867  * @return <0 if error, 0 if everything is fine
1868  */
1869 int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
1870 		int (*bind)(struct usb_gadget *))
1871 {
1872 	struct musb		*musb = the_gadget;
1873 	unsigned long		flags;
1874 	int			retval = -EINVAL;
1875 
1876 	if (!driver
1877 			|| driver->speed != USB_SPEED_HIGH
1878 			|| !bind || !driver->setup)
1879 		goto err0;
1880 
1881 	/* driver must be initialized to support peripheral mode */
1882 	if (!musb) {
1883 		dev_dbg(musb->controller, "no dev??\n");
1884 		retval = -ENODEV;
1885 		goto err0;
1886 	}
1887 
1888 	pm_runtime_get_sync(musb->controller);
1889 
1890 	dev_dbg(musb->controller, "registering driver %s\n", driver->function);
1891 
1892 	if (musb->gadget_driver) {
1893 		dev_dbg(musb->controller, "%s is already bound to %s\n",
1894 				musb_driver_name,
1895 				musb->gadget_driver->driver.name);
1896 		retval = -EBUSY;
1897 		goto err0;
1898 	}
1899 
1900 	spin_lock_irqsave(&musb->lock, flags);
1901 	musb->gadget_driver = driver;
1902 	musb->g.dev.driver = &driver->driver;
1903 	driver->driver.bus = NULL;
1904 	musb->softconnect = 1;
1905 	spin_unlock_irqrestore(&musb->lock, flags);
1906 
1907 	retval = bind(&musb->g);
1908 	if (retval) {
1909 		dev_dbg(musb->controller, "bind to driver %s failed --> %d\n",
1910 				driver->driver.name, retval);
1911 		goto err1;
1912 	}
1913 
1914 	spin_lock_irqsave(&musb->lock, flags);
1915 
1916 	otg_set_peripheral(musb->xceiv, &musb->g);
1917 	musb->xceiv->state = OTG_STATE_B_IDLE;
1918 	musb->is_active = 1;
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 	otg_set_peripheral(musb->xceiv, &musb->g);
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 
1964 err1:
1965 	musb->gadget_driver = NULL;
1966 	musb->g.dev.driver = NULL;
1967 
1968 err0:
1969 	return retval;
1970 }
1971 EXPORT_SYMBOL(usb_gadget_probe_driver);
1972 
1973 static void stop_activity(struct musb *musb, struct usb_gadget_driver *driver)
1974 {
1975 	int			i;
1976 	struct musb_hw_ep	*hw_ep;
1977 
1978 	/* don't disconnect if it's not connected */
1979 	if (musb->g.speed == USB_SPEED_UNKNOWN)
1980 		driver = NULL;
1981 	else
1982 		musb->g.speed = USB_SPEED_UNKNOWN;
1983 
1984 	/* deactivate the hardware */
1985 	if (musb->softconnect) {
1986 		musb->softconnect = 0;
1987 		musb_pullup(musb, 0);
1988 	}
1989 	musb_stop(musb);
1990 
1991 	/* killing any outstanding requests will quiesce the driver;
1992 	 * then report disconnect
1993 	 */
1994 	if (driver) {
1995 		for (i = 0, hw_ep = musb->endpoints;
1996 				i < musb->nr_endpoints;
1997 				i++, hw_ep++) {
1998 			musb_ep_select(musb->mregs, i);
1999 			if (hw_ep->is_shared_fifo /* || !epnum */) {
2000 				nuke(&hw_ep->ep_in, -ESHUTDOWN);
2001 			} else {
2002 				if (hw_ep->max_packet_sz_tx)
2003 					nuke(&hw_ep->ep_in, -ESHUTDOWN);
2004 				if (hw_ep->max_packet_sz_rx)
2005 					nuke(&hw_ep->ep_out, -ESHUTDOWN);
2006 			}
2007 		}
2008 
2009 		spin_unlock(&musb->lock);
2010 		driver->disconnect(&musb->g);
2011 		spin_lock(&musb->lock);
2012 	}
2013 }
2014 
2015 /*
2016  * Unregister the gadget driver. Used by gadget drivers when
2017  * unregistering themselves from the controller.
2018  *
2019  * @param driver the gadget driver to unregister
2020  */
2021 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
2022 {
2023 	struct musb	*musb = the_gadget;
2024 	unsigned long	flags;
2025 
2026 	if (!driver || !driver->unbind || !musb)
2027 		return -EINVAL;
2028 
2029 	if (!musb->gadget_driver)
2030 		return -EINVAL;
2031 
2032 	if (musb->xceiv->last_event == USB_EVENT_NONE)
2033 		pm_runtime_get_sync(musb->controller);
2034 
2035 	/*
2036 	 * REVISIT always use otg_set_peripheral() here too;
2037 	 * this needs to shut down the OTG engine.
2038 	 */
2039 
2040 	spin_lock_irqsave(&musb->lock, flags);
2041 
2042 #ifdef	CONFIG_USB_MUSB_OTG
2043 	musb_hnp_stop(musb);
2044 #endif
2045 
2046 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2047 
2048 	musb->xceiv->state = OTG_STATE_UNDEFINED;
2049 	stop_activity(musb, driver);
2050 	otg_set_peripheral(musb->xceiv, NULL);
2051 
2052 	dev_dbg(musb->controller, "unregistering driver %s\n", driver->function);
2053 
2054 	spin_unlock_irqrestore(&musb->lock, flags);
2055 	driver->unbind(&musb->g);
2056 	spin_lock_irqsave(&musb->lock, flags);
2057 
2058 	musb->gadget_driver = NULL;
2059 	musb->g.dev.driver = NULL;
2060 
2061 	musb->is_active = 0;
2062 	musb_platform_try_idle(musb, 0);
2063 	spin_unlock_irqrestore(&musb->lock, flags);
2064 
2065 	if (is_otg_enabled(musb)) {
2066 		usb_remove_hcd(musb_to_hcd(musb));
2067 		/* FIXME we need to be able to register another
2068 		 * gadget driver here and have everything work;
2069 		 * that currently misbehaves.
2070 		 */
2071 	}
2072 
2073 	if (!is_otg_enabled(musb))
2074 		musb_stop(musb);
2075 
2076 	pm_runtime_put(musb->controller);
2077 
2078 	return 0;
2079 }
2080 EXPORT_SYMBOL(usb_gadget_unregister_driver);
2081 
2082 
2083 /* ----------------------------------------------------------------------- */
2084 
2085 /* lifecycle operations called through plat_uds.c */
2086 
2087 void musb_g_resume(struct musb *musb)
2088 {
2089 	musb->is_suspended = 0;
2090 	switch (musb->xceiv->state) {
2091 	case OTG_STATE_B_IDLE:
2092 		break;
2093 	case OTG_STATE_B_WAIT_ACON:
2094 	case OTG_STATE_B_PERIPHERAL:
2095 		musb->is_active = 1;
2096 		if (musb->gadget_driver && musb->gadget_driver->resume) {
2097 			spin_unlock(&musb->lock);
2098 			musb->gadget_driver->resume(&musb->g);
2099 			spin_lock(&musb->lock);
2100 		}
2101 		break;
2102 	default:
2103 		WARNING("unhandled RESUME transition (%s)\n",
2104 				otg_state_string(musb->xceiv->state));
2105 	}
2106 }
2107 
2108 /* called when SOF packets stop for 3+ msec */
2109 void musb_g_suspend(struct musb *musb)
2110 {
2111 	u8	devctl;
2112 
2113 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2114 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2115 
2116 	switch (musb->xceiv->state) {
2117 	case OTG_STATE_B_IDLE:
2118 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2119 			musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2120 		break;
2121 	case OTG_STATE_B_PERIPHERAL:
2122 		musb->is_suspended = 1;
2123 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
2124 			spin_unlock(&musb->lock);
2125 			musb->gadget_driver->suspend(&musb->g);
2126 			spin_lock(&musb->lock);
2127 		}
2128 		break;
2129 	default:
2130 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
2131 		 * A_PERIPHERAL may need care too
2132 		 */
2133 		WARNING("unhandled SUSPEND transition (%s)\n",
2134 				otg_state_string(musb->xceiv->state));
2135 	}
2136 }
2137 
2138 /* Called during SRP */
2139 void musb_g_wakeup(struct musb *musb)
2140 {
2141 	musb_gadget_wakeup(&musb->g);
2142 }
2143 
2144 /* called when VBUS drops below session threshold, and in other cases */
2145 void musb_g_disconnect(struct musb *musb)
2146 {
2147 	void __iomem	*mregs = musb->mregs;
2148 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
2149 
2150 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2151 
2152 	/* clear HR */
2153 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
2154 
2155 	/* don't draw vbus until new b-default session */
2156 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2157 
2158 	musb->g.speed = USB_SPEED_UNKNOWN;
2159 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
2160 		spin_unlock(&musb->lock);
2161 		musb->gadget_driver->disconnect(&musb->g);
2162 		spin_lock(&musb->lock);
2163 	}
2164 
2165 	switch (musb->xceiv->state) {
2166 	default:
2167 #ifdef	CONFIG_USB_MUSB_OTG
2168 		dev_dbg(musb->controller, "Unhandled disconnect %s, setting a_idle\n",
2169 			otg_state_string(musb->xceiv->state));
2170 		musb->xceiv->state = OTG_STATE_A_IDLE;
2171 		MUSB_HST_MODE(musb);
2172 		break;
2173 	case OTG_STATE_A_PERIPHERAL:
2174 		musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2175 		MUSB_HST_MODE(musb);
2176 		break;
2177 	case OTG_STATE_B_WAIT_ACON:
2178 	case OTG_STATE_B_HOST:
2179 #endif
2180 	case OTG_STATE_B_PERIPHERAL:
2181 	case OTG_STATE_B_IDLE:
2182 		musb->xceiv->state = OTG_STATE_B_IDLE;
2183 		break;
2184 	case OTG_STATE_B_SRP_INIT:
2185 		break;
2186 	}
2187 
2188 	musb->is_active = 0;
2189 }
2190 
2191 void musb_g_reset(struct musb *musb)
2192 __releases(musb->lock)
2193 __acquires(musb->lock)
2194 {
2195 	void __iomem	*mbase = musb->mregs;
2196 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2197 	u8		power;
2198 
2199 	dev_dbg(musb->controller, "<== %s addr=%x driver '%s'\n",
2200 			(devctl & MUSB_DEVCTL_BDEVICE)
2201 				? "B-Device" : "A-Device",
2202 			musb_readb(mbase, MUSB_FADDR),
2203 			musb->gadget_driver
2204 				? musb->gadget_driver->driver.name
2205 				: NULL
2206 			);
2207 
2208 	/* report disconnect, if we didn't already (flushing EP state) */
2209 	if (musb->g.speed != USB_SPEED_UNKNOWN)
2210 		musb_g_disconnect(musb);
2211 
2212 	/* clear HR */
2213 	else if (devctl & MUSB_DEVCTL_HR)
2214 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2215 
2216 
2217 	/* what speed did we negotiate? */
2218 	power = musb_readb(mbase, MUSB_POWER);
2219 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2220 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2221 
2222 	/* start in USB_STATE_DEFAULT */
2223 	musb->is_active = 1;
2224 	musb->is_suspended = 0;
2225 	MUSB_DEV_MODE(musb);
2226 	musb->address = 0;
2227 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2228 
2229 	musb->may_wakeup = 0;
2230 	musb->g.b_hnp_enable = 0;
2231 	musb->g.a_alt_hnp_support = 0;
2232 	musb->g.a_hnp_support = 0;
2233 
2234 	/* Normal reset, as B-Device;
2235 	 * or else after HNP, as A-Device
2236 	 */
2237 	if (devctl & MUSB_DEVCTL_BDEVICE) {
2238 		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2239 		musb->g.is_a_peripheral = 0;
2240 	} else if (is_otg_enabled(musb)) {
2241 		musb->xceiv->state = OTG_STATE_A_PERIPHERAL;
2242 		musb->g.is_a_peripheral = 1;
2243 	} else
2244 		WARN_ON(1);
2245 
2246 	/* start with default limits on VBUS power draw */
2247 	(void) musb_gadget_vbus_draw(&musb->g,
2248 			is_otg_enabled(musb) ? 8 : 100);
2249 }
2250