xref: /openbmc/linux/drivers/usb/musb/musb_gadget.c (revision ce932d0c5589e9766e089c22c66890dfc48fbd94)
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 			/*
578 			 * In the giveback function the MUSB lock is
579 			 * released and acquired after sometime. During
580 			 * this time period the INDEX register could get
581 			 * changed by the gadget_queue function especially
582 			 * on SMP systems. Reselect the INDEX to be sure
583 			 * we are reading/modifying the right registers
584 			 */
585 			musb_ep_select(mbase, epnum);
586 			req = musb_ep->desc ? next_request(musb_ep) : NULL;
587 			if (!req) {
588 				dev_dbg(musb->controller, "%s idle now\n",
589 					musb_ep->end_point.name);
590 				return;
591 			}
592 		}
593 
594 		txstate(musb, req);
595 	}
596 }
597 
598 /* ------------------------------------------------------------ */
599 
600 #ifdef CONFIG_USB_INVENTRA_DMA
601 
602 /* Peripheral rx (OUT) using Mentor DMA works as follows:
603 	- Only mode 0 is used.
604 
605 	- Request is queued by the gadget class driver.
606 		-> if queue was previously empty, rxstate()
607 
608 	- Host sends OUT token which causes an endpoint interrupt
609 	  /\      -> RxReady
610 	  |	      -> if request queued, call rxstate
611 	  |		/\	-> setup DMA
612 	  |		|	     -> DMA interrupt on completion
613 	  |		|		-> RxReady
614 	  |		|		      -> stop DMA
615 	  |		|		      -> ack the read
616 	  |		|		      -> if data recd = max expected
617 	  |		|				by the request, or host
618 	  |		|				sent a short packet,
619 	  |		|				complete the request,
620 	  |		|				and start the next one.
621 	  |		|_____________________________________|
622 	  |					 else just wait for the host
623 	  |					    to send the next OUT token.
624 	  |__________________________________________________|
625 
626  * Non-Mentor DMA engines can of course work differently.
627  */
628 
629 #endif
630 
631 /*
632  * Context: controller locked, IRQs blocked, endpoint selected
633  */
634 static void rxstate(struct musb *musb, struct musb_request *req)
635 {
636 	const u8		epnum = req->epnum;
637 	struct usb_request	*request = &req->request;
638 	struct musb_ep		*musb_ep;
639 	void __iomem		*epio = musb->endpoints[epnum].regs;
640 	unsigned		fifo_count = 0;
641 	u16			len;
642 	u16			csr = musb_readw(epio, MUSB_RXCSR);
643 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
644 	u8			use_mode_1;
645 
646 	if (hw_ep->is_shared_fifo)
647 		musb_ep = &hw_ep->ep_in;
648 	else
649 		musb_ep = &hw_ep->ep_out;
650 
651 	len = musb_ep->packet_sz;
652 
653 	/* We shouldn't get here while DMA is active, but we do... */
654 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
655 		dev_dbg(musb->controller, "DMA pending...\n");
656 		return;
657 	}
658 
659 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
660 		dev_dbg(musb->controller, "%s stalling, RXCSR %04x\n",
661 		    musb_ep->end_point.name, csr);
662 		return;
663 	}
664 
665 	if (is_cppi_enabled() && is_buffer_mapped(req)) {
666 		struct dma_controller	*c = musb->dma_controller;
667 		struct dma_channel	*channel = musb_ep->dma;
668 
669 		/* NOTE:  CPPI won't actually stop advancing the DMA
670 		 * queue after short packet transfers, so this is almost
671 		 * always going to run as IRQ-per-packet DMA so that
672 		 * faults will be handled correctly.
673 		 */
674 		if (c->channel_program(channel,
675 				musb_ep->packet_sz,
676 				!request->short_not_ok,
677 				request->dma + request->actual,
678 				request->length - request->actual)) {
679 
680 			/* make sure that if an rxpkt arrived after the irq,
681 			 * the cppi engine will be ready to take it as soon
682 			 * as DMA is enabled
683 			 */
684 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
685 					| MUSB_RXCSR_DMAMODE);
686 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
687 			musb_writew(epio, MUSB_RXCSR, csr);
688 			return;
689 		}
690 	}
691 
692 	if (csr & MUSB_RXCSR_RXPKTRDY) {
693 		len = musb_readw(epio, MUSB_RXCOUNT);
694 
695 		/*
696 		 * Enable Mode 1 on RX transfers only when short_not_ok flag
697 		 * is set. Currently short_not_ok flag is set only from
698 		 * file_storage and f_mass_storage drivers
699 		 */
700 
701 		if (request->short_not_ok && len == musb_ep->packet_sz)
702 			use_mode_1 = 1;
703 		else
704 			use_mode_1 = 0;
705 
706 		if (request->actual < request->length) {
707 #ifdef CONFIG_USB_INVENTRA_DMA
708 			if (is_buffer_mapped(req)) {
709 				struct dma_controller	*c;
710 				struct dma_channel	*channel;
711 				int			use_dma = 0;
712 
713 				c = musb->dma_controller;
714 				channel = musb_ep->dma;
715 
716 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
717 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
718 	 * completion. We only get interrupts from DMA controller.
719 	 *
720 	 * We could operate in DMA mode 1 if we knew the size of the tranfer
721 	 * in advance. For mass storage class, request->length = what the host
722 	 * sends, so that'd work.  But for pretty much everything else,
723 	 * request->length is routinely more than what the host sends. For
724 	 * most these gadgets, end of is signified either by a short packet,
725 	 * or filling the last byte of the buffer.  (Sending extra data in
726 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
727 	 * we don't get DMA completion interrupt for short packets.
728 	 *
729 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
730 	 * to get endpoint interrupt on every DMA req, but that didn't seem
731 	 * to work reliably.
732 	 *
733 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
734 	 * then becomes usable as a runtime "use mode 1" hint...
735 	 */
736 
737 				/* Experimental: Mode1 works with mass storage use cases */
738 				if (use_mode_1) {
739 					csr |= MUSB_RXCSR_AUTOCLEAR;
740 					musb_writew(epio, MUSB_RXCSR, csr);
741 					csr |= MUSB_RXCSR_DMAENAB;
742 					musb_writew(epio, MUSB_RXCSR, csr);
743 
744 					/*
745 					 * this special sequence (enabling and then
746 					 * disabling MUSB_RXCSR_DMAMODE) is required
747 					 * to get DMAReq to activate
748 					 */
749 					musb_writew(epio, MUSB_RXCSR,
750 						csr | MUSB_RXCSR_DMAMODE);
751 					musb_writew(epio, MUSB_RXCSR, csr);
752 
753 				} else {
754 					if (!musb_ep->hb_mult &&
755 						musb_ep->hw_ep->rx_double_buffered)
756 						csr |= MUSB_RXCSR_AUTOCLEAR;
757 					csr |= MUSB_RXCSR_DMAENAB;
758 					musb_writew(epio, MUSB_RXCSR, csr);
759 				}
760 
761 				if (request->actual < request->length) {
762 					int transfer_size = 0;
763 					if (use_mode_1) {
764 						transfer_size = min(request->length - request->actual,
765 								channel->max_len);
766 						musb_ep->dma->desired_mode = 1;
767 					} else {
768 						transfer_size = min(request->length - request->actual,
769 								(unsigned)len);
770 						musb_ep->dma->desired_mode = 0;
771 					}
772 
773 					use_dma = c->channel_program(
774 							channel,
775 							musb_ep->packet_sz,
776 							channel->desired_mode,
777 							request->dma
778 							+ request->actual,
779 							transfer_size);
780 				}
781 
782 				if (use_dma)
783 					return;
784 			}
785 #elif defined(CONFIG_USB_UX500_DMA)
786 			if ((is_buffer_mapped(req)) &&
787 				(request->actual < request->length)) {
788 
789 				struct dma_controller *c;
790 				struct dma_channel *channel;
791 				int transfer_size = 0;
792 
793 				c = musb->dma_controller;
794 				channel = musb_ep->dma;
795 
796 				/* In case first packet is short */
797 				if (len < musb_ep->packet_sz)
798 					transfer_size = len;
799 				else if (request->short_not_ok)
800 					transfer_size =	min(request->length -
801 							request->actual,
802 							channel->max_len);
803 				else
804 					transfer_size = min(request->length -
805 							request->actual,
806 							(unsigned)len);
807 
808 				csr &= ~MUSB_RXCSR_DMAMODE;
809 				csr |= (MUSB_RXCSR_DMAENAB |
810 					MUSB_RXCSR_AUTOCLEAR);
811 
812 				musb_writew(epio, MUSB_RXCSR, csr);
813 
814 				if (transfer_size <= musb_ep->packet_sz) {
815 					musb_ep->dma->desired_mode = 0;
816 				} else {
817 					musb_ep->dma->desired_mode = 1;
818 					/* Mode must be set after DMAENAB */
819 					csr |= MUSB_RXCSR_DMAMODE;
820 					musb_writew(epio, MUSB_RXCSR, csr);
821 				}
822 
823 				if (c->channel_program(channel,
824 							musb_ep->packet_sz,
825 							channel->desired_mode,
826 							request->dma
827 							+ request->actual,
828 							transfer_size))
829 
830 					return;
831 			}
832 #endif	/* Mentor's DMA */
833 
834 			fifo_count = request->length - request->actual;
835 			dev_dbg(musb->controller, "%s OUT/RX pio fifo %d/%d, maxpacket %d\n",
836 					musb_ep->end_point.name,
837 					len, fifo_count,
838 					musb_ep->packet_sz);
839 
840 			fifo_count = min_t(unsigned, len, fifo_count);
841 
842 #ifdef	CONFIG_USB_TUSB_OMAP_DMA
843 			if (tusb_dma_omap() && is_buffer_mapped(req)) {
844 				struct dma_controller *c = musb->dma_controller;
845 				struct dma_channel *channel = musb_ep->dma;
846 				u32 dma_addr = request->dma + request->actual;
847 				int ret;
848 
849 				ret = c->channel_program(channel,
850 						musb_ep->packet_sz,
851 						channel->desired_mode,
852 						dma_addr,
853 						fifo_count);
854 				if (ret)
855 					return;
856 			}
857 #endif
858 			/*
859 			 * Unmap the dma buffer back to cpu if dma channel
860 			 * programming fails. This buffer is mapped if the
861 			 * channel allocation is successful
862 			 */
863 			 if (is_buffer_mapped(req)) {
864 				unmap_dma_buffer(req, musb);
865 
866 				/*
867 				 * Clear DMAENAB and AUTOCLEAR for the
868 				 * PIO mode transfer
869 				 */
870 				csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
871 				musb_writew(epio, MUSB_RXCSR, csr);
872 			}
873 
874 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
875 					(request->buf + request->actual));
876 			request->actual += fifo_count;
877 
878 			/* REVISIT if we left anything in the fifo, flush
879 			 * it and report -EOVERFLOW
880 			 */
881 
882 			/* ack the read! */
883 			csr |= MUSB_RXCSR_P_WZC_BITS;
884 			csr &= ~MUSB_RXCSR_RXPKTRDY;
885 			musb_writew(epio, MUSB_RXCSR, csr);
886 		}
887 	}
888 
889 	/* reach the end or short packet detected */
890 	if (request->actual == request->length || len < musb_ep->packet_sz)
891 		musb_g_giveback(musb_ep, request, 0);
892 }
893 
894 /*
895  * Data ready for a request; called from IRQ
896  */
897 void musb_g_rx(struct musb *musb, u8 epnum)
898 {
899 	u16			csr;
900 	struct musb_request	*req;
901 	struct usb_request	*request;
902 	void __iomem		*mbase = musb->mregs;
903 	struct musb_ep		*musb_ep;
904 	void __iomem		*epio = musb->endpoints[epnum].regs;
905 	struct dma_channel	*dma;
906 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
907 
908 	if (hw_ep->is_shared_fifo)
909 		musb_ep = &hw_ep->ep_in;
910 	else
911 		musb_ep = &hw_ep->ep_out;
912 
913 	musb_ep_select(mbase, epnum);
914 
915 	req = next_request(musb_ep);
916 	if (!req)
917 		return;
918 
919 	request = &req->request;
920 
921 	csr = musb_readw(epio, MUSB_RXCSR);
922 	dma = is_dma_capable() ? musb_ep->dma : NULL;
923 
924 	dev_dbg(musb->controller, "<== %s, rxcsr %04x%s %p\n", musb_ep->end_point.name,
925 			csr, dma ? " (dma)" : "", request);
926 
927 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
928 		csr |= MUSB_RXCSR_P_WZC_BITS;
929 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
930 		musb_writew(epio, MUSB_RXCSR, csr);
931 		return;
932 	}
933 
934 	if (csr & MUSB_RXCSR_P_OVERRUN) {
935 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
936 		csr &= ~MUSB_RXCSR_P_OVERRUN;
937 		musb_writew(epio, MUSB_RXCSR, csr);
938 
939 		dev_dbg(musb->controller, "%s iso overrun on %p\n", musb_ep->name, request);
940 		if (request->status == -EINPROGRESS)
941 			request->status = -EOVERFLOW;
942 	}
943 	if (csr & MUSB_RXCSR_INCOMPRX) {
944 		/* REVISIT not necessarily an error */
945 		dev_dbg(musb->controller, "%s, incomprx\n", musb_ep->end_point.name);
946 	}
947 
948 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
949 		/* "should not happen"; likely RXPKTRDY pending for DMA */
950 		dev_dbg(musb->controller, "%s busy, csr %04x\n",
951 			musb_ep->end_point.name, csr);
952 		return;
953 	}
954 
955 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
956 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
957 				| MUSB_RXCSR_DMAENAB
958 				| MUSB_RXCSR_DMAMODE);
959 		musb_writew(epio, MUSB_RXCSR,
960 			MUSB_RXCSR_P_WZC_BITS | csr);
961 
962 		request->actual += musb_ep->dma->actual_len;
963 
964 		dev_dbg(musb->controller, "RXCSR%d %04x, dma off, %04x, len %zu, req %p\n",
965 			epnum, csr,
966 			musb_readw(epio, MUSB_RXCSR),
967 			musb_ep->dma->actual_len, request);
968 
969 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
970 	defined(CONFIG_USB_UX500_DMA)
971 		/* Autoclear doesn't clear RxPktRdy for short packets */
972 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
973 				|| (dma->actual_len
974 					& (musb_ep->packet_sz - 1))) {
975 			/* ack the read! */
976 			csr &= ~MUSB_RXCSR_RXPKTRDY;
977 			musb_writew(epio, MUSB_RXCSR, csr);
978 		}
979 
980 		/* incomplete, and not short? wait for next IN packet */
981 		if ((request->actual < request->length)
982 				&& (musb_ep->dma->actual_len
983 					== musb_ep->packet_sz)) {
984 			/* In double buffer case, continue to unload fifo if
985  			 * there is Rx packet in FIFO.
986  			 **/
987 			csr = musb_readw(epio, MUSB_RXCSR);
988 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
989 				hw_ep->rx_double_buffered)
990 				goto exit;
991 			return;
992 		}
993 #endif
994 		musb_g_giveback(musb_ep, request, 0);
995 		/*
996 		 * In the giveback function the MUSB lock is
997 		 * released and acquired after sometime. During
998 		 * this time period the INDEX register could get
999 		 * changed by the gadget_queue function especially
1000 		 * on SMP systems. Reselect the INDEX to be sure
1001 		 * we are reading/modifying the right registers
1002 		 */
1003 		musb_ep_select(mbase, epnum);
1004 
1005 		req = next_request(musb_ep);
1006 		if (!req)
1007 			return;
1008 	}
1009 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
1010 	defined(CONFIG_USB_UX500_DMA)
1011 exit:
1012 #endif
1013 	/* Analyze request */
1014 	rxstate(musb, req);
1015 }
1016 
1017 /* ------------------------------------------------------------ */
1018 
1019 static int musb_gadget_enable(struct usb_ep *ep,
1020 			const struct usb_endpoint_descriptor *desc)
1021 {
1022 	unsigned long		flags;
1023 	struct musb_ep		*musb_ep;
1024 	struct musb_hw_ep	*hw_ep;
1025 	void __iomem		*regs;
1026 	struct musb		*musb;
1027 	void __iomem	*mbase;
1028 	u8		epnum;
1029 	u16		csr;
1030 	unsigned	tmp;
1031 	int		status = -EINVAL;
1032 
1033 	if (!ep || !desc)
1034 		return -EINVAL;
1035 
1036 	musb_ep = to_musb_ep(ep);
1037 	hw_ep = musb_ep->hw_ep;
1038 	regs = hw_ep->regs;
1039 	musb = musb_ep->musb;
1040 	mbase = musb->mregs;
1041 	epnum = musb_ep->current_epnum;
1042 
1043 	spin_lock_irqsave(&musb->lock, flags);
1044 
1045 	if (musb_ep->desc) {
1046 		status = -EBUSY;
1047 		goto fail;
1048 	}
1049 	musb_ep->type = usb_endpoint_type(desc);
1050 
1051 	/* check direction and (later) maxpacket size against endpoint */
1052 	if (usb_endpoint_num(desc) != epnum)
1053 		goto fail;
1054 
1055 	/* REVISIT this rules out high bandwidth periodic transfers */
1056 	tmp = usb_endpoint_maxp(desc);
1057 	if (tmp & ~0x07ff) {
1058 		int ok;
1059 
1060 		if (usb_endpoint_dir_in(desc))
1061 			ok = musb->hb_iso_tx;
1062 		else
1063 			ok = musb->hb_iso_rx;
1064 
1065 		if (!ok) {
1066 			dev_dbg(musb->controller, "no support for high bandwidth ISO\n");
1067 			goto fail;
1068 		}
1069 		musb_ep->hb_mult = (tmp >> 11) & 3;
1070 	} else {
1071 		musb_ep->hb_mult = 0;
1072 	}
1073 
1074 	musb_ep->packet_sz = tmp & 0x7ff;
1075 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
1076 
1077 	/* enable the interrupts for the endpoint, set the endpoint
1078 	 * packet size (or fail), set the mode, clear the fifo
1079 	 */
1080 	musb_ep_select(mbase, epnum);
1081 	if (usb_endpoint_dir_in(desc)) {
1082 		u16 int_txe = musb_readw(mbase, MUSB_INTRTXE);
1083 
1084 		if (hw_ep->is_shared_fifo)
1085 			musb_ep->is_in = 1;
1086 		if (!musb_ep->is_in)
1087 			goto fail;
1088 
1089 		if (tmp > hw_ep->max_packet_sz_tx) {
1090 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1091 			goto fail;
1092 		}
1093 
1094 		int_txe |= (1 << epnum);
1095 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
1096 
1097 		/* REVISIT if can_bulk_split(), use by updating "tmp";
1098 		 * likewise high bandwidth periodic tx
1099 		 */
1100 		/* Set TXMAXP with the FIFO size of the endpoint
1101 		 * to disable double buffering mode.
1102 		 */
1103 		if (musb->double_buffer_not_ok)
1104 			musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
1105 		else
1106 			musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
1107 					| (musb_ep->hb_mult << 11));
1108 
1109 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
1110 		if (musb_readw(regs, MUSB_TXCSR)
1111 				& MUSB_TXCSR_FIFONOTEMPTY)
1112 			csr |= MUSB_TXCSR_FLUSHFIFO;
1113 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1114 			csr |= MUSB_TXCSR_P_ISO;
1115 
1116 		/* set twice in case of double buffering */
1117 		musb_writew(regs, MUSB_TXCSR, csr);
1118 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1119 		musb_writew(regs, MUSB_TXCSR, csr);
1120 
1121 	} else {
1122 		u16 int_rxe = musb_readw(mbase, MUSB_INTRRXE);
1123 
1124 		if (hw_ep->is_shared_fifo)
1125 			musb_ep->is_in = 0;
1126 		if (musb_ep->is_in)
1127 			goto fail;
1128 
1129 		if (tmp > hw_ep->max_packet_sz_rx) {
1130 			dev_dbg(musb->controller, "packet size beyond hardware FIFO size\n");
1131 			goto fail;
1132 		}
1133 
1134 		int_rxe |= (1 << epnum);
1135 		musb_writew(mbase, MUSB_INTRRXE, int_rxe);
1136 
1137 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1138 		 * likewise high bandwidth periodic rx
1139 		 */
1140 		/* Set RXMAXP with the FIFO size of the endpoint
1141 		 * to disable double buffering mode.
1142 		 */
1143 		if (musb->double_buffer_not_ok)
1144 			musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_tx);
1145 		else
1146 			musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1147 					| (musb_ep->hb_mult << 11));
1148 
1149 		/* force shared fifo to OUT-only mode */
1150 		if (hw_ep->is_shared_fifo) {
1151 			csr = musb_readw(regs, MUSB_TXCSR);
1152 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1153 			musb_writew(regs, MUSB_TXCSR, csr);
1154 		}
1155 
1156 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1157 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1158 			csr |= MUSB_RXCSR_P_ISO;
1159 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1160 			csr |= MUSB_RXCSR_DISNYET;
1161 
1162 		/* set twice in case of double buffering */
1163 		musb_writew(regs, MUSB_RXCSR, csr);
1164 		musb_writew(regs, MUSB_RXCSR, csr);
1165 	}
1166 
1167 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1168 	 * for some reason you run out of channels here.
1169 	 */
1170 	if (is_dma_capable() && musb->dma_controller) {
1171 		struct dma_controller	*c = musb->dma_controller;
1172 
1173 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1174 				(desc->bEndpointAddress & USB_DIR_IN));
1175 	} else
1176 		musb_ep->dma = NULL;
1177 
1178 	musb_ep->desc = desc;
1179 	musb_ep->busy = 0;
1180 	musb_ep->wedged = 0;
1181 	status = 0;
1182 
1183 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1184 			musb_driver_name, musb_ep->end_point.name,
1185 			({ char *s; switch (musb_ep->type) {
1186 			case USB_ENDPOINT_XFER_BULK:	s = "bulk"; break;
1187 			case USB_ENDPOINT_XFER_INT:	s = "int"; break;
1188 			default:			s = "iso"; break;
1189 			}; s; }),
1190 			musb_ep->is_in ? "IN" : "OUT",
1191 			musb_ep->dma ? "dma, " : "",
1192 			musb_ep->packet_sz);
1193 
1194 	schedule_work(&musb->irq_work);
1195 
1196 fail:
1197 	spin_unlock_irqrestore(&musb->lock, flags);
1198 	return status;
1199 }
1200 
1201 /*
1202  * Disable an endpoint flushing all requests queued.
1203  */
1204 static int musb_gadget_disable(struct usb_ep *ep)
1205 {
1206 	unsigned long	flags;
1207 	struct musb	*musb;
1208 	u8		epnum;
1209 	struct musb_ep	*musb_ep;
1210 	void __iomem	*epio;
1211 	int		status = 0;
1212 
1213 	musb_ep = to_musb_ep(ep);
1214 	musb = musb_ep->musb;
1215 	epnum = musb_ep->current_epnum;
1216 	epio = musb->endpoints[epnum].regs;
1217 
1218 	spin_lock_irqsave(&musb->lock, flags);
1219 	musb_ep_select(musb->mregs, epnum);
1220 
1221 	/* zero the endpoint sizes */
1222 	if (musb_ep->is_in) {
1223 		u16 int_txe = musb_readw(musb->mregs, MUSB_INTRTXE);
1224 		int_txe &= ~(1 << epnum);
1225 		musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
1226 		musb_writew(epio, MUSB_TXMAXP, 0);
1227 	} else {
1228 		u16 int_rxe = musb_readw(musb->mregs, MUSB_INTRRXE);
1229 		int_rxe &= ~(1 << epnum);
1230 		musb_writew(musb->mregs, MUSB_INTRRXE, int_rxe);
1231 		musb_writew(epio, MUSB_RXMAXP, 0);
1232 	}
1233 
1234 	musb_ep->desc = NULL;
1235 
1236 	/* abort all pending DMA and requests */
1237 	nuke(musb_ep, -ESHUTDOWN);
1238 
1239 	schedule_work(&musb->irq_work);
1240 
1241 	spin_unlock_irqrestore(&(musb->lock), flags);
1242 
1243 	dev_dbg(musb->controller, "%s\n", musb_ep->end_point.name);
1244 
1245 	return status;
1246 }
1247 
1248 /*
1249  * Allocate a request for an endpoint.
1250  * Reused by ep0 code.
1251  */
1252 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1253 {
1254 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1255 	struct musb		*musb = musb_ep->musb;
1256 	struct musb_request	*request = NULL;
1257 
1258 	request = kzalloc(sizeof *request, gfp_flags);
1259 	if (!request) {
1260 		dev_dbg(musb->controller, "not enough memory\n");
1261 		return NULL;
1262 	}
1263 
1264 	request->request.dma = DMA_ADDR_INVALID;
1265 	request->epnum = musb_ep->current_epnum;
1266 	request->ep = musb_ep;
1267 
1268 	return &request->request;
1269 }
1270 
1271 /*
1272  * Free a request
1273  * Reused by ep0 code.
1274  */
1275 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1276 {
1277 	kfree(to_musb_request(req));
1278 }
1279 
1280 static LIST_HEAD(buffers);
1281 
1282 struct free_record {
1283 	struct list_head	list;
1284 	struct device		*dev;
1285 	unsigned		bytes;
1286 	dma_addr_t		dma;
1287 };
1288 
1289 /*
1290  * Context: controller locked, IRQs blocked.
1291  */
1292 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1293 {
1294 	dev_dbg(musb->controller, "<== %s request %p len %u on hw_ep%d\n",
1295 		req->tx ? "TX/IN" : "RX/OUT",
1296 		&req->request, req->request.length, req->epnum);
1297 
1298 	musb_ep_select(musb->mregs, req->epnum);
1299 	if (req->tx)
1300 		txstate(musb, req);
1301 	else
1302 		rxstate(musb, req);
1303 }
1304 
1305 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1306 			gfp_t gfp_flags)
1307 {
1308 	struct musb_ep		*musb_ep;
1309 	struct musb_request	*request;
1310 	struct musb		*musb;
1311 	int			status = 0;
1312 	unsigned long		lockflags;
1313 
1314 	if (!ep || !req)
1315 		return -EINVAL;
1316 	if (!req->buf)
1317 		return -ENODATA;
1318 
1319 	musb_ep = to_musb_ep(ep);
1320 	musb = musb_ep->musb;
1321 
1322 	request = to_musb_request(req);
1323 	request->musb = musb;
1324 
1325 	if (request->ep != musb_ep)
1326 		return -EINVAL;
1327 
1328 	dev_dbg(musb->controller, "<== to %s request=%p\n", ep->name, req);
1329 
1330 	/* request is mine now... */
1331 	request->request.actual = 0;
1332 	request->request.status = -EINPROGRESS;
1333 	request->epnum = musb_ep->current_epnum;
1334 	request->tx = musb_ep->is_in;
1335 
1336 	map_dma_buffer(request, musb, musb_ep);
1337 
1338 	spin_lock_irqsave(&musb->lock, lockflags);
1339 
1340 	/* don't queue if the ep is down */
1341 	if (!musb_ep->desc) {
1342 		dev_dbg(musb->controller, "req %p queued to %s while ep %s\n",
1343 				req, ep->name, "disabled");
1344 		status = -ESHUTDOWN;
1345 		goto cleanup;
1346 	}
1347 
1348 	/* add request to the list */
1349 	list_add_tail(&request->list, &musb_ep->req_list);
1350 
1351 	/* it this is the head of the queue, start i/o ... */
1352 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next)
1353 		musb_ep_restart(musb, request);
1354 
1355 cleanup:
1356 	spin_unlock_irqrestore(&musb->lock, lockflags);
1357 	return status;
1358 }
1359 
1360 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1361 {
1362 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1363 	struct musb_request	*req = to_musb_request(request);
1364 	struct musb_request	*r;
1365 	unsigned long		flags;
1366 	int			status = 0;
1367 	struct musb		*musb = musb_ep->musb;
1368 
1369 	if (!ep || !request || to_musb_request(request)->ep != musb_ep)
1370 		return -EINVAL;
1371 
1372 	spin_lock_irqsave(&musb->lock, flags);
1373 
1374 	list_for_each_entry(r, &musb_ep->req_list, list) {
1375 		if (r == req)
1376 			break;
1377 	}
1378 	if (r != req) {
1379 		dev_dbg(musb->controller, "request %p not queued to %s\n", request, ep->name);
1380 		status = -EINVAL;
1381 		goto done;
1382 	}
1383 
1384 	/* if the hardware doesn't have the request, easy ... */
1385 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1386 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1387 
1388 	/* ... else abort the dma transfer ... */
1389 	else if (is_dma_capable() && musb_ep->dma) {
1390 		struct dma_controller	*c = musb->dma_controller;
1391 
1392 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1393 		if (c->channel_abort)
1394 			status = c->channel_abort(musb_ep->dma);
1395 		else
1396 			status = -EBUSY;
1397 		if (status == 0)
1398 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1399 	} else {
1400 		/* NOTE: by sticking to easily tested hardware/driver states,
1401 		 * we leave counting of in-flight packets imprecise.
1402 		 */
1403 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1404 	}
1405 
1406 done:
1407 	spin_unlock_irqrestore(&musb->lock, flags);
1408 	return status;
1409 }
1410 
1411 /*
1412  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1413  * data but will queue requests.
1414  *
1415  * exported to ep0 code
1416  */
1417 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1418 {
1419 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1420 	u8			epnum = musb_ep->current_epnum;
1421 	struct musb		*musb = musb_ep->musb;
1422 	void __iomem		*epio = musb->endpoints[epnum].regs;
1423 	void __iomem		*mbase;
1424 	unsigned long		flags;
1425 	u16			csr;
1426 	struct musb_request	*request;
1427 	int			status = 0;
1428 
1429 	if (!ep)
1430 		return -EINVAL;
1431 	mbase = musb->mregs;
1432 
1433 	spin_lock_irqsave(&musb->lock, flags);
1434 
1435 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1436 		status = -EINVAL;
1437 		goto done;
1438 	}
1439 
1440 	musb_ep_select(mbase, epnum);
1441 
1442 	request = next_request(musb_ep);
1443 	if (value) {
1444 		if (request) {
1445 			dev_dbg(musb->controller, "request in progress, cannot halt %s\n",
1446 			    ep->name);
1447 			status = -EAGAIN;
1448 			goto done;
1449 		}
1450 		/* Cannot portably stall with non-empty FIFO */
1451 		if (musb_ep->is_in) {
1452 			csr = musb_readw(epio, MUSB_TXCSR);
1453 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1454 				dev_dbg(musb->controller, "FIFO busy, cannot halt %s\n", ep->name);
1455 				status = -EAGAIN;
1456 				goto done;
1457 			}
1458 		}
1459 	} else
1460 		musb_ep->wedged = 0;
1461 
1462 	/* set/clear the stall and toggle bits */
1463 	dev_dbg(musb->controller, "%s: %s stall\n", ep->name, value ? "set" : "clear");
1464 	if (musb_ep->is_in) {
1465 		csr = musb_readw(epio, MUSB_TXCSR);
1466 		csr |= MUSB_TXCSR_P_WZC_BITS
1467 			| MUSB_TXCSR_CLRDATATOG;
1468 		if (value)
1469 			csr |= MUSB_TXCSR_P_SENDSTALL;
1470 		else
1471 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1472 				| MUSB_TXCSR_P_SENTSTALL);
1473 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1474 		musb_writew(epio, MUSB_TXCSR, csr);
1475 	} else {
1476 		csr = musb_readw(epio, MUSB_RXCSR);
1477 		csr |= MUSB_RXCSR_P_WZC_BITS
1478 			| MUSB_RXCSR_FLUSHFIFO
1479 			| MUSB_RXCSR_CLRDATATOG;
1480 		if (value)
1481 			csr |= MUSB_RXCSR_P_SENDSTALL;
1482 		else
1483 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1484 				| MUSB_RXCSR_P_SENTSTALL);
1485 		musb_writew(epio, MUSB_RXCSR, csr);
1486 	}
1487 
1488 	/* maybe start the first request in the queue */
1489 	if (!musb_ep->busy && !value && request) {
1490 		dev_dbg(musb->controller, "restarting the request\n");
1491 		musb_ep_restart(musb, request);
1492 	}
1493 
1494 done:
1495 	spin_unlock_irqrestore(&musb->lock, flags);
1496 	return status;
1497 }
1498 
1499 /*
1500  * Sets the halt feature with the clear requests ignored
1501  */
1502 static int musb_gadget_set_wedge(struct usb_ep *ep)
1503 {
1504 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1505 
1506 	if (!ep)
1507 		return -EINVAL;
1508 
1509 	musb_ep->wedged = 1;
1510 
1511 	return usb_ep_set_halt(ep);
1512 }
1513 
1514 static int musb_gadget_fifo_status(struct usb_ep *ep)
1515 {
1516 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1517 	void __iomem		*epio = musb_ep->hw_ep->regs;
1518 	int			retval = -EINVAL;
1519 
1520 	if (musb_ep->desc && !musb_ep->is_in) {
1521 		struct musb		*musb = musb_ep->musb;
1522 		int			epnum = musb_ep->current_epnum;
1523 		void __iomem		*mbase = musb->mregs;
1524 		unsigned long		flags;
1525 
1526 		spin_lock_irqsave(&musb->lock, flags);
1527 
1528 		musb_ep_select(mbase, epnum);
1529 		/* FIXME return zero unless RXPKTRDY is set */
1530 		retval = musb_readw(epio, MUSB_RXCOUNT);
1531 
1532 		spin_unlock_irqrestore(&musb->lock, flags);
1533 	}
1534 	return retval;
1535 }
1536 
1537 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1538 {
1539 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1540 	struct musb	*musb = musb_ep->musb;
1541 	u8		epnum = musb_ep->current_epnum;
1542 	void __iomem	*epio = musb->endpoints[epnum].regs;
1543 	void __iomem	*mbase;
1544 	unsigned long	flags;
1545 	u16		csr, int_txe;
1546 
1547 	mbase = musb->mregs;
1548 
1549 	spin_lock_irqsave(&musb->lock, flags);
1550 	musb_ep_select(mbase, (u8) epnum);
1551 
1552 	/* disable interrupts */
1553 	int_txe = musb_readw(mbase, MUSB_INTRTXE);
1554 	musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
1555 
1556 	if (musb_ep->is_in) {
1557 		csr = musb_readw(epio, MUSB_TXCSR);
1558 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1559 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1560 			/*
1561 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1562 			 * to interrupt current FIFO loading, but not flushing
1563 			 * the already loaded ones.
1564 			 */
1565 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1566 			musb_writew(epio, MUSB_TXCSR, csr);
1567 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1568 			musb_writew(epio, MUSB_TXCSR, csr);
1569 		}
1570 	} else {
1571 		csr = musb_readw(epio, MUSB_RXCSR);
1572 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1573 		musb_writew(epio, MUSB_RXCSR, csr);
1574 		musb_writew(epio, MUSB_RXCSR, csr);
1575 	}
1576 
1577 	/* re-enable interrupt */
1578 	musb_writew(mbase, MUSB_INTRTXE, int_txe);
1579 	spin_unlock_irqrestore(&musb->lock, flags);
1580 }
1581 
1582 static const struct usb_ep_ops musb_ep_ops = {
1583 	.enable		= musb_gadget_enable,
1584 	.disable	= musb_gadget_disable,
1585 	.alloc_request	= musb_alloc_request,
1586 	.free_request	= musb_free_request,
1587 	.queue		= musb_gadget_queue,
1588 	.dequeue	= musb_gadget_dequeue,
1589 	.set_halt	= musb_gadget_set_halt,
1590 	.set_wedge	= musb_gadget_set_wedge,
1591 	.fifo_status	= musb_gadget_fifo_status,
1592 	.fifo_flush	= musb_gadget_fifo_flush
1593 };
1594 
1595 /* ----------------------------------------------------------------------- */
1596 
1597 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1598 {
1599 	struct musb	*musb = gadget_to_musb(gadget);
1600 
1601 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1602 }
1603 
1604 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1605 {
1606 	struct musb	*musb = gadget_to_musb(gadget);
1607 	void __iomem	*mregs = musb->mregs;
1608 	unsigned long	flags;
1609 	int		status = -EINVAL;
1610 	u8		power, devctl;
1611 	int		retries;
1612 
1613 	spin_lock_irqsave(&musb->lock, flags);
1614 
1615 	switch (musb->xceiv->state) {
1616 	case OTG_STATE_B_PERIPHERAL:
1617 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1618 		 * that's part of the standard usb 1.1 state machine, and
1619 		 * doesn't affect OTG transitions.
1620 		 */
1621 		if (musb->may_wakeup && musb->is_suspended)
1622 			break;
1623 		goto done;
1624 	case OTG_STATE_B_IDLE:
1625 		/* Start SRP ... OTG not required. */
1626 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1627 		dev_dbg(musb->controller, "Sending SRP: devctl: %02x\n", devctl);
1628 		devctl |= MUSB_DEVCTL_SESSION;
1629 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1630 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1631 		retries = 100;
1632 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1633 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1634 			if (retries-- < 1)
1635 				break;
1636 		}
1637 		retries = 10000;
1638 		while (devctl & MUSB_DEVCTL_SESSION) {
1639 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1640 			if (retries-- < 1)
1641 				break;
1642 		}
1643 
1644 		spin_unlock_irqrestore(&musb->lock, flags);
1645 		otg_start_srp(musb->xceiv->otg);
1646 		spin_lock_irqsave(&musb->lock, flags);
1647 
1648 		/* Block idling for at least 1s */
1649 		musb_platform_try_idle(musb,
1650 			jiffies + msecs_to_jiffies(1 * HZ));
1651 
1652 		status = 0;
1653 		goto done;
1654 	default:
1655 		dev_dbg(musb->controller, "Unhandled wake: %s\n",
1656 			otg_state_string(musb->xceiv->state));
1657 		goto done;
1658 	}
1659 
1660 	status = 0;
1661 
1662 	power = musb_readb(mregs, MUSB_POWER);
1663 	power |= MUSB_POWER_RESUME;
1664 	musb_writeb(mregs, MUSB_POWER, power);
1665 	dev_dbg(musb->controller, "issue wakeup\n");
1666 
1667 	/* FIXME do this next chunk in a timer callback, no udelay */
1668 	mdelay(2);
1669 
1670 	power = musb_readb(mregs, MUSB_POWER);
1671 	power &= ~MUSB_POWER_RESUME;
1672 	musb_writeb(mregs, MUSB_POWER, power);
1673 done:
1674 	spin_unlock_irqrestore(&musb->lock, flags);
1675 	return status;
1676 }
1677 
1678 static int
1679 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1680 {
1681 	struct musb	*musb = gadget_to_musb(gadget);
1682 
1683 	musb->is_self_powered = !!is_selfpowered;
1684 	return 0;
1685 }
1686 
1687 static void musb_pullup(struct musb *musb, int is_on)
1688 {
1689 	u8 power;
1690 
1691 	power = musb_readb(musb->mregs, MUSB_POWER);
1692 	if (is_on)
1693 		power |= MUSB_POWER_SOFTCONN;
1694 	else
1695 		power &= ~MUSB_POWER_SOFTCONN;
1696 
1697 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1698 
1699 	dev_dbg(musb->controller, "gadget D+ pullup %s\n",
1700 		is_on ? "on" : "off");
1701 	musb_writeb(musb->mregs, MUSB_POWER, power);
1702 }
1703 
1704 #if 0
1705 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1706 {
1707 	dev_dbg(musb->controller, "<= %s =>\n", __func__);
1708 
1709 	/*
1710 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1711 	 * though that can clear it), just musb_pullup().
1712 	 */
1713 
1714 	return -EINVAL;
1715 }
1716 #endif
1717 
1718 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1719 {
1720 	struct musb	*musb = gadget_to_musb(gadget);
1721 
1722 	if (!musb->xceiv->set_power)
1723 		return -EOPNOTSUPP;
1724 	return usb_phy_set_power(musb->xceiv, mA);
1725 }
1726 
1727 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1728 {
1729 	struct musb	*musb = gadget_to_musb(gadget);
1730 	unsigned long	flags;
1731 
1732 	is_on = !!is_on;
1733 
1734 	pm_runtime_get_sync(musb->controller);
1735 
1736 	/* NOTE: this assumes we are sensing vbus; we'd rather
1737 	 * not pullup unless the B-session is active.
1738 	 */
1739 	spin_lock_irqsave(&musb->lock, flags);
1740 	if (is_on != musb->softconnect) {
1741 		musb->softconnect = is_on;
1742 		musb_pullup(musb, is_on);
1743 	}
1744 	spin_unlock_irqrestore(&musb->lock, flags);
1745 
1746 	pm_runtime_put(musb->controller);
1747 
1748 	return 0;
1749 }
1750 
1751 static int musb_gadget_start(struct usb_gadget *g,
1752 		struct usb_gadget_driver *driver);
1753 static int musb_gadget_stop(struct usb_gadget *g,
1754 		struct usb_gadget_driver *driver);
1755 
1756 static const struct usb_gadget_ops musb_gadget_operations = {
1757 	.get_frame		= musb_gadget_get_frame,
1758 	.wakeup			= musb_gadget_wakeup,
1759 	.set_selfpowered	= musb_gadget_set_self_powered,
1760 	/* .vbus_session		= musb_gadget_vbus_session, */
1761 	.vbus_draw		= musb_gadget_vbus_draw,
1762 	.pullup			= musb_gadget_pullup,
1763 	.udc_start		= musb_gadget_start,
1764 	.udc_stop		= musb_gadget_stop,
1765 };
1766 
1767 /* ----------------------------------------------------------------------- */
1768 
1769 /* Registration */
1770 
1771 /* Only this registration code "knows" the rule (from USB standards)
1772  * about there being only one external upstream port.  It assumes
1773  * all peripheral ports are external...
1774  */
1775 
1776 static void musb_gadget_release(struct device *dev)
1777 {
1778 	/* kref_put(WHAT) */
1779 	dev_dbg(dev, "%s\n", __func__);
1780 }
1781 
1782 
1783 static void __devinit
1784 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1785 {
1786 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1787 
1788 	memset(ep, 0, sizeof *ep);
1789 
1790 	ep->current_epnum = epnum;
1791 	ep->musb = musb;
1792 	ep->hw_ep = hw_ep;
1793 	ep->is_in = is_in;
1794 
1795 	INIT_LIST_HEAD(&ep->req_list);
1796 
1797 	sprintf(ep->name, "ep%d%s", epnum,
1798 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1799 				is_in ? "in" : "out"));
1800 	ep->end_point.name = ep->name;
1801 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1802 	if (!epnum) {
1803 		ep->end_point.maxpacket = 64;
1804 		ep->end_point.ops = &musb_g_ep0_ops;
1805 		musb->g.ep0 = &ep->end_point;
1806 	} else {
1807 		if (is_in)
1808 			ep->end_point.maxpacket = hw_ep->max_packet_sz_tx;
1809 		else
1810 			ep->end_point.maxpacket = hw_ep->max_packet_sz_rx;
1811 		ep->end_point.ops = &musb_ep_ops;
1812 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1813 	}
1814 }
1815 
1816 /*
1817  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1818  * to the rest of the driver state.
1819  */
1820 static inline void __devinit musb_g_init_endpoints(struct musb *musb)
1821 {
1822 	u8			epnum;
1823 	struct musb_hw_ep	*hw_ep;
1824 	unsigned		count = 0;
1825 
1826 	/* initialize endpoint list just once */
1827 	INIT_LIST_HEAD(&(musb->g.ep_list));
1828 
1829 	for (epnum = 0, hw_ep = musb->endpoints;
1830 			epnum < musb->nr_endpoints;
1831 			epnum++, hw_ep++) {
1832 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1833 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1834 			count++;
1835 		} else {
1836 			if (hw_ep->max_packet_sz_tx) {
1837 				init_peripheral_ep(musb, &hw_ep->ep_in,
1838 							epnum, 1);
1839 				count++;
1840 			}
1841 			if (hw_ep->max_packet_sz_rx) {
1842 				init_peripheral_ep(musb, &hw_ep->ep_out,
1843 							epnum, 0);
1844 				count++;
1845 			}
1846 		}
1847 	}
1848 }
1849 
1850 /* called once during driver setup to initialize and link into
1851  * the driver model; memory is zeroed.
1852  */
1853 int __devinit musb_gadget_setup(struct musb *musb)
1854 {
1855 	int status;
1856 
1857 	/* REVISIT minor race:  if (erroneously) setting up two
1858 	 * musb peripherals at the same time, only the bus lock
1859 	 * is probably held.
1860 	 */
1861 
1862 	musb->g.ops = &musb_gadget_operations;
1863 	musb->g.max_speed = USB_SPEED_HIGH;
1864 	musb->g.speed = USB_SPEED_UNKNOWN;
1865 
1866 	/* this "gadget" abstracts/virtualizes the controller */
1867 	dev_set_name(&musb->g.dev, "gadget");
1868 	musb->g.dev.parent = musb->controller;
1869 	musb->g.dev.dma_mask = musb->controller->dma_mask;
1870 	musb->g.dev.release = musb_gadget_release;
1871 	musb->g.name = musb_driver_name;
1872 
1873 	if (is_otg_enabled(musb))
1874 		musb->g.is_otg = 1;
1875 
1876 	musb_g_init_endpoints(musb);
1877 
1878 	musb->is_active = 0;
1879 	musb_platform_try_idle(musb, 0);
1880 
1881 	status = device_register(&musb->g.dev);
1882 	if (status != 0) {
1883 		put_device(&musb->g.dev);
1884 		return status;
1885 	}
1886 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1887 	if (status)
1888 		goto err;
1889 
1890 	return 0;
1891 err:
1892 	musb->g.dev.parent = NULL;
1893 	device_unregister(&musb->g.dev);
1894 	return status;
1895 }
1896 
1897 void musb_gadget_cleanup(struct musb *musb)
1898 {
1899 	usb_del_gadget_udc(&musb->g);
1900 	if (musb->g.dev.parent)
1901 		device_unregister(&musb->g.dev);
1902 }
1903 
1904 /*
1905  * Register the gadget driver. Used by gadget drivers when
1906  * registering themselves with the controller.
1907  *
1908  * -EINVAL something went wrong (not driver)
1909  * -EBUSY another gadget is already using the controller
1910  * -ENOMEM no memory to perform the operation
1911  *
1912  * @param driver the gadget driver
1913  * @return <0 if error, 0 if everything is fine
1914  */
1915 static int musb_gadget_start(struct usb_gadget *g,
1916 		struct usb_gadget_driver *driver)
1917 {
1918 	struct musb		*musb = gadget_to_musb(g);
1919 	struct usb_otg		*otg = musb->xceiv->otg;
1920 	unsigned long		flags;
1921 	int			retval = -EINVAL;
1922 
1923 	if (driver->max_speed < USB_SPEED_HIGH)
1924 		goto err0;
1925 
1926 	pm_runtime_get_sync(musb->controller);
1927 
1928 	dev_dbg(musb->controller, "registering driver %s\n", driver->function);
1929 
1930 	musb->softconnect = 0;
1931 	musb->gadget_driver = driver;
1932 
1933 	spin_lock_irqsave(&musb->lock, flags);
1934 	musb->is_active = 1;
1935 
1936 	otg_set_peripheral(otg, &musb->g);
1937 	musb->xceiv->state = OTG_STATE_B_IDLE;
1938 
1939 	/*
1940 	 * FIXME this ignores the softconnect flag.  Drivers are
1941 	 * allowed hold the peripheral inactive until for example
1942 	 * userspace hooks up printer hardware or DSP codecs, so
1943 	 * hosts only see fully functional devices.
1944 	 */
1945 
1946 	if (!is_otg_enabled(musb))
1947 		musb_start(musb);
1948 
1949 	spin_unlock_irqrestore(&musb->lock, flags);
1950 
1951 	if (is_otg_enabled(musb)) {
1952 		struct usb_hcd	*hcd = musb_to_hcd(musb);
1953 
1954 		dev_dbg(musb->controller, "OTG startup...\n");
1955 
1956 		/* REVISIT:  funcall to other code, which also
1957 		 * handles power budgeting ... this way also
1958 		 * ensures HdrcStart is indirectly called.
1959 		 */
1960 		retval = usb_add_hcd(musb_to_hcd(musb), 0, 0);
1961 		if (retval < 0) {
1962 			dev_dbg(musb->controller, "add_hcd failed, %d\n", retval);
1963 			goto err2;
1964 		}
1965 
1966 		if ((musb->xceiv->last_event == USB_EVENT_ID)
1967 					&& otg->set_vbus)
1968 			otg_set_vbus(otg, 1);
1969 
1970 		hcd->self.uses_pio_for_control = 1;
1971 	}
1972 	if (musb->xceiv->last_event == USB_EVENT_NONE)
1973 		pm_runtime_put(musb->controller);
1974 
1975 	return 0;
1976 
1977 err2:
1978 	if (!is_otg_enabled(musb))
1979 		musb_stop(musb);
1980 err0:
1981 	return retval;
1982 }
1983 
1984 static void stop_activity(struct musb *musb, struct usb_gadget_driver *driver)
1985 {
1986 	int			i;
1987 	struct musb_hw_ep	*hw_ep;
1988 
1989 	/* don't disconnect if it's not connected */
1990 	if (musb->g.speed == USB_SPEED_UNKNOWN)
1991 		driver = NULL;
1992 	else
1993 		musb->g.speed = USB_SPEED_UNKNOWN;
1994 
1995 	/* deactivate the hardware */
1996 	if (musb->softconnect) {
1997 		musb->softconnect = 0;
1998 		musb_pullup(musb, 0);
1999 	}
2000 	musb_stop(musb);
2001 
2002 	/* killing any outstanding requests will quiesce the driver;
2003 	 * then report disconnect
2004 	 */
2005 	if (driver) {
2006 		for (i = 0, hw_ep = musb->endpoints;
2007 				i < musb->nr_endpoints;
2008 				i++, hw_ep++) {
2009 			musb_ep_select(musb->mregs, i);
2010 			if (hw_ep->is_shared_fifo /* || !epnum */) {
2011 				nuke(&hw_ep->ep_in, -ESHUTDOWN);
2012 			} else {
2013 				if (hw_ep->max_packet_sz_tx)
2014 					nuke(&hw_ep->ep_in, -ESHUTDOWN);
2015 				if (hw_ep->max_packet_sz_rx)
2016 					nuke(&hw_ep->ep_out, -ESHUTDOWN);
2017 			}
2018 		}
2019 	}
2020 }
2021 
2022 /*
2023  * Unregister the gadget driver. Used by gadget drivers when
2024  * unregistering themselves from the controller.
2025  *
2026  * @param driver the gadget driver to unregister
2027  */
2028 static int musb_gadget_stop(struct usb_gadget *g,
2029 		struct usb_gadget_driver *driver)
2030 {
2031 	struct musb	*musb = gadget_to_musb(g);
2032 	unsigned long	flags;
2033 
2034 	if (musb->xceiv->last_event == USB_EVENT_NONE)
2035 		pm_runtime_get_sync(musb->controller);
2036 
2037 	/*
2038 	 * REVISIT always use otg_set_peripheral() here too;
2039 	 * this needs to shut down the OTG engine.
2040 	 */
2041 
2042 	spin_lock_irqsave(&musb->lock, flags);
2043 
2044 	musb_hnp_stop(musb);
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->otg, NULL);
2051 
2052 	dev_dbg(musb->controller, "unregistering driver %s\n", driver->function);
2053 
2054 	musb->is_active = 0;
2055 	musb_platform_try_idle(musb, 0);
2056 	spin_unlock_irqrestore(&musb->lock, flags);
2057 
2058 	if (is_otg_enabled(musb)) {
2059 		usb_remove_hcd(musb_to_hcd(musb));
2060 		/* FIXME we need to be able to register another
2061 		 * gadget driver here and have everything work;
2062 		 * that currently misbehaves.
2063 		 */
2064 	}
2065 
2066 	if (!is_otg_enabled(musb))
2067 		musb_stop(musb);
2068 
2069 	pm_runtime_put(musb->controller);
2070 
2071 	return 0;
2072 }
2073 
2074 /* ----------------------------------------------------------------------- */
2075 
2076 /* lifecycle operations called through plat_uds.c */
2077 
2078 void musb_g_resume(struct musb *musb)
2079 {
2080 	musb->is_suspended = 0;
2081 	switch (musb->xceiv->state) {
2082 	case OTG_STATE_B_IDLE:
2083 		break;
2084 	case OTG_STATE_B_WAIT_ACON:
2085 	case OTG_STATE_B_PERIPHERAL:
2086 		musb->is_active = 1;
2087 		if (musb->gadget_driver && musb->gadget_driver->resume) {
2088 			spin_unlock(&musb->lock);
2089 			musb->gadget_driver->resume(&musb->g);
2090 			spin_lock(&musb->lock);
2091 		}
2092 		break;
2093 	default:
2094 		WARNING("unhandled RESUME transition (%s)\n",
2095 				otg_state_string(musb->xceiv->state));
2096 	}
2097 }
2098 
2099 /* called when SOF packets stop for 3+ msec */
2100 void musb_g_suspend(struct musb *musb)
2101 {
2102 	u8	devctl;
2103 
2104 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2105 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2106 
2107 	switch (musb->xceiv->state) {
2108 	case OTG_STATE_B_IDLE:
2109 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2110 			musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2111 		break;
2112 	case OTG_STATE_B_PERIPHERAL:
2113 		musb->is_suspended = 1;
2114 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
2115 			spin_unlock(&musb->lock);
2116 			musb->gadget_driver->suspend(&musb->g);
2117 			spin_lock(&musb->lock);
2118 		}
2119 		break;
2120 	default:
2121 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
2122 		 * A_PERIPHERAL may need care too
2123 		 */
2124 		WARNING("unhandled SUSPEND transition (%s)\n",
2125 				otg_state_string(musb->xceiv->state));
2126 	}
2127 }
2128 
2129 /* Called during SRP */
2130 void musb_g_wakeup(struct musb *musb)
2131 {
2132 	musb_gadget_wakeup(&musb->g);
2133 }
2134 
2135 /* called when VBUS drops below session threshold, and in other cases */
2136 void musb_g_disconnect(struct musb *musb)
2137 {
2138 	void __iomem	*mregs = musb->mregs;
2139 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
2140 
2141 	dev_dbg(musb->controller, "devctl %02x\n", devctl);
2142 
2143 	/* clear HR */
2144 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
2145 
2146 	/* don't draw vbus until new b-default session */
2147 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2148 
2149 	musb->g.speed = USB_SPEED_UNKNOWN;
2150 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
2151 		spin_unlock(&musb->lock);
2152 		musb->gadget_driver->disconnect(&musb->g);
2153 		spin_lock(&musb->lock);
2154 	}
2155 
2156 	switch (musb->xceiv->state) {
2157 	default:
2158 		dev_dbg(musb->controller, "Unhandled disconnect %s, setting a_idle\n",
2159 			otg_state_string(musb->xceiv->state));
2160 		musb->xceiv->state = OTG_STATE_A_IDLE;
2161 		MUSB_HST_MODE(musb);
2162 		break;
2163 	case OTG_STATE_A_PERIPHERAL:
2164 		musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2165 		MUSB_HST_MODE(musb);
2166 		break;
2167 	case OTG_STATE_B_WAIT_ACON:
2168 	case OTG_STATE_B_HOST:
2169 	case OTG_STATE_B_PERIPHERAL:
2170 	case OTG_STATE_B_IDLE:
2171 		musb->xceiv->state = OTG_STATE_B_IDLE;
2172 		break;
2173 	case OTG_STATE_B_SRP_INIT:
2174 		break;
2175 	}
2176 
2177 	musb->is_active = 0;
2178 }
2179 
2180 void musb_g_reset(struct musb *musb)
2181 __releases(musb->lock)
2182 __acquires(musb->lock)
2183 {
2184 	void __iomem	*mbase = musb->mregs;
2185 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2186 	u8		power;
2187 
2188 	dev_dbg(musb->controller, "<== %s addr=%x driver '%s'\n",
2189 			(devctl & MUSB_DEVCTL_BDEVICE)
2190 				? "B-Device" : "A-Device",
2191 			musb_readb(mbase, MUSB_FADDR),
2192 			musb->gadget_driver
2193 				? musb->gadget_driver->driver.name
2194 				: NULL
2195 			);
2196 
2197 	/* report disconnect, if we didn't already (flushing EP state) */
2198 	if (musb->g.speed != USB_SPEED_UNKNOWN)
2199 		musb_g_disconnect(musb);
2200 
2201 	/* clear HR */
2202 	else if (devctl & MUSB_DEVCTL_HR)
2203 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2204 
2205 
2206 	/* what speed did we negotiate? */
2207 	power = musb_readb(mbase, MUSB_POWER);
2208 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2209 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2210 
2211 	/* start in USB_STATE_DEFAULT */
2212 	musb->is_active = 1;
2213 	musb->is_suspended = 0;
2214 	MUSB_DEV_MODE(musb);
2215 	musb->address = 0;
2216 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2217 
2218 	musb->may_wakeup = 0;
2219 	musb->g.b_hnp_enable = 0;
2220 	musb->g.a_alt_hnp_support = 0;
2221 	musb->g.a_hnp_support = 0;
2222 
2223 	/* Normal reset, as B-Device;
2224 	 * or else after HNP, as A-Device
2225 	 */
2226 	if (devctl & MUSB_DEVCTL_BDEVICE) {
2227 		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2228 		musb->g.is_a_peripheral = 0;
2229 	} else if (is_otg_enabled(musb)) {
2230 		musb->xceiv->state = OTG_STATE_A_PERIPHERAL;
2231 		musb->g.is_a_peripheral = 1;
2232 	} else
2233 		WARN_ON(1);
2234 
2235 	/* start with default limits on VBUS power draw */
2236 	(void) musb_gadget_vbus_draw(&musb->g,
2237 			is_otg_enabled(musb) ? 8 : 100);
2238 }
2239