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 
map_dma_buffer(struct musb_request * request,struct musb * musb,struct musb_ep * musb_ep)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 */
unmap_dma_buffer(struct musb_request * request,struct musb * musb)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 		DBG(20, "not unmapping a never mapped buffer\n");
151 		return;
152 	}
153 	if (request->map_state == MUSB_MAPPED) {
154 		dma_unmap_single(musb->controller,
155 			request->request.dma,
156 			request->request.length,
157 			request->tx
158 				? DMA_TO_DEVICE
159 				: DMA_FROM_DEVICE);
160 		request->request.dma = DMA_ADDR_INVALID;
161 	} else { /* PRE_MAPPED */
162 		dma_sync_single_for_cpu(musb->controller,
163 			request->request.dma,
164 			request->request.length,
165 			request->tx
166 				? DMA_TO_DEVICE
167 				: DMA_FROM_DEVICE);
168 	}
169 	request->map_state = UN_MAPPED;
170 }
171 
172 /*
173  * Immediately complete a request.
174  *
175  * @param request the request to complete
176  * @param status the status to complete the request with
177  * Context: controller locked, IRQs blocked.
178  */
musb_g_giveback(struct musb_ep * ep,struct usb_request * request,int status)179 void musb_g_giveback(
180 	struct musb_ep		*ep,
181 	struct usb_request	*request,
182 	int			status)
183 __releases(ep->musb->lock)
184 __acquires(ep->musb->lock)
185 {
186 	struct musb_request	*req;
187 	struct musb		*musb;
188 	int			busy = ep->busy;
189 
190 	req = to_musb_request(request);
191 
192 	list_del(&req->list);
193 	if (req->request.status == -EINPROGRESS)
194 		req->request.status = status;
195 	musb = req->musb;
196 
197 	ep->busy = 1;
198 	spin_unlock(&musb->lock);
199 	unmap_dma_buffer(req, musb);
200 	if (request->status == 0)
201 		DBG(5, "%s done request %p,  %d/%d\n",
202 				ep->end_point.name, request,
203 				req->request.actual, req->request.length);
204 	else
205 		DBG(2, "%s request %p, %d/%d fault %d\n",
206 				ep->end_point.name, request,
207 				req->request.actual, req->request.length,
208 				request->status);
209 	req->request.complete(&req->ep->end_point, &req->request);
210 	spin_lock(&musb->lock);
211 	ep->busy = busy;
212 }
213 
214 /* ----------------------------------------------------------------------- */
215 
216 /*
217  * Abort requests queued to an endpoint using the status. Synchronous.
218  * caller locked controller and blocked irqs, and selected this ep.
219  */
nuke(struct musb_ep * ep,const int status)220 static void nuke(struct musb_ep *ep, const int status)
221 {
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 		DBG(value ? 1 : 6, "%s: abort DMA --> %d\n", ep->name, value);
250 		c->channel_release(ep->dma);
251 		ep->dma = NULL;
252 	}
253 
254 	while (!list_empty(&ep->req_list)) {
255 		req = list_first_entry(&ep->req_list, struct musb_request, list);
256 		musb_g_giveback(ep, &req->request, status);
257 	}
258 }
259 
260 /* ----------------------------------------------------------------------- */
261 
262 /* Data transfers - pure PIO, pure DMA, or mixed mode */
263 
264 /*
265  * This assumes the separate CPPI engine is responding to DMA requests
266  * from the usb core ... sequenced a bit differently from mentor dma.
267  */
268 
max_ep_writesize(struct musb * musb,struct musb_ep * ep)269 static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
270 {
271 	if (can_bulk_split(musb, ep->type))
272 		return ep->hw_ep->max_packet_sz_tx;
273 	else
274 		return ep->packet_sz;
275 }
276 
277 
278 #ifdef CONFIG_USB_INVENTRA_DMA
279 
280 /* Peripheral tx (IN) using Mentor DMA works as follows:
281 	Only mode 0 is used for transfers <= wPktSize,
282 	mode 1 is used for larger transfers,
283 
284 	One of the following happens:
285 	- Host sends IN token which causes an endpoint interrupt
286 		-> TxAvail
287 			-> if DMA is currently busy, exit.
288 			-> if queue is non-empty, txstate().
289 
290 	- Request is queued by the gadget driver.
291 		-> if queue was previously empty, txstate()
292 
293 	txstate()
294 		-> start
295 		  /\	-> setup DMA
296 		  |     (data is transferred to the FIFO, then sent out when
297 		  |	IN token(s) are recd from Host.
298 		  |		-> DMA interrupt on completion
299 		  |		   calls TxAvail.
300 		  |		      -> stop DMA, ~DMAENAB,
301 		  |		      -> set TxPktRdy for last short pkt or zlp
302 		  |		      -> Complete Request
303 		  |		      -> Continue next request (call txstate)
304 		  |___________________________________|
305 
306  * Non-Mentor DMA engines can of course work differently, such as by
307  * upleveling from irq-per-packet to irq-per-buffer.
308  */
309 
310 #endif
311 
312 /*
313  * An endpoint is transmitting data. This can be called either from
314  * the IRQ routine or from ep.queue() to kickstart a request on an
315  * endpoint.
316  *
317  * Context: controller locked, IRQs blocked, endpoint selected
318  */
txstate(struct musb * musb,struct musb_request * req)319 static void txstate(struct musb *musb, struct musb_request *req)
320 {
321 	u8			epnum = req->epnum;
322 	struct musb_ep		*musb_ep;
323 	void __iomem		*epio = musb->endpoints[epnum].regs;
324 	struct usb_request	*request;
325 	u16			fifo_count = 0, csr;
326 	int			use_dma = 0;
327 
328 	musb_ep = req->ep;
329 
330 	/* we shouldn't get here while DMA is active ... but we do ... */
331 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
332 		DBG(4, "dma pending...\n");
333 		return;
334 	}
335 
336 	/* read TXCSR before */
337 	csr = musb_readw(epio, MUSB_TXCSR);
338 
339 	request = &req->request;
340 	fifo_count = min(max_ep_writesize(musb, musb_ep),
341 			(int)(request->length - request->actual));
342 
343 	if (csr & MUSB_TXCSR_TXPKTRDY) {
344 		DBG(5, "%s old packet still ready , txcsr %03x\n",
345 				musb_ep->end_point.name, csr);
346 		return;
347 	}
348 
349 	if (csr & MUSB_TXCSR_P_SENDSTALL) {
350 		DBG(5, "%s stalling, txcsr %03x\n",
351 				musb_ep->end_point.name, csr);
352 		return;
353 	}
354 
355 	DBG(4, "hw_ep%d, maxpacket %d, fifo count %d, txcsr %03x\n",
356 			epnum, musb_ep->packet_sz, fifo_count,
357 			csr);
358 
359 #ifndef	CONFIG_MUSB_PIO_ONLY
360 	if (is_buffer_mapped(req)) {
361 		struct dma_controller	*c = musb->dma_controller;
362 		size_t request_size;
363 
364 		/* setup DMA, then program endpoint CSR */
365 		request_size = min_t(size_t, request->length - request->actual,
366 					musb_ep->dma->max_len);
367 
368 		use_dma = (request->dma != DMA_ADDR_INVALID);
369 
370 		/* MUSB_TXCSR_P_ISO is still set correctly */
371 
372 #ifdef CONFIG_USB_INVENTRA_DMA
373 		{
374 			if (request_size < musb_ep->packet_sz)
375 				musb_ep->dma->desired_mode = 0;
376 			else
377 				musb_ep->dma->desired_mode = 1;
378 
379 			use_dma = use_dma && c->channel_program(
380 					musb_ep->dma, musb_ep->packet_sz,
381 					musb_ep->dma->desired_mode,
382 					request->dma + request->actual, request_size);
383 			if (use_dma) {
384 				if (musb_ep->dma->desired_mode == 0) {
385 					/*
386 					 * We must not clear the DMAMODE bit
387 					 * before the DMAENAB bit -- and the
388 					 * latter doesn't always get cleared
389 					 * before we get here...
390 					 */
391 					csr &= ~(MUSB_TXCSR_AUTOSET
392 						| MUSB_TXCSR_DMAENAB);
393 					musb_writew(epio, MUSB_TXCSR, csr
394 						| MUSB_TXCSR_P_WZC_BITS);
395 					csr &= ~MUSB_TXCSR_DMAMODE;
396 					csr |= (MUSB_TXCSR_DMAENAB |
397 							MUSB_TXCSR_MODE);
398 					/* against programming guide */
399 				} else {
400 					csr |= (MUSB_TXCSR_DMAENAB
401 							| MUSB_TXCSR_DMAMODE
402 							| MUSB_TXCSR_MODE);
403 					if (!musb_ep->hb_mult)
404 						csr |= MUSB_TXCSR_AUTOSET;
405 				}
406 				csr &= ~MUSB_TXCSR_P_UNDERRUN;
407 
408 				musb_writew(epio, MUSB_TXCSR, csr);
409 			}
410 		}
411 
412 #elif defined(CONFIG_USB_TI_CPPI_DMA)
413 		/* program endpoint CSR first, then setup DMA */
414 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
415 		csr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_DMAMODE |
416 		       MUSB_TXCSR_MODE;
417 		musb_writew(epio, MUSB_TXCSR,
418 			(MUSB_TXCSR_P_WZC_BITS & ~MUSB_TXCSR_P_UNDERRUN)
419 				| csr);
420 
421 		/* ensure writebuffer is empty */
422 		csr = musb_readw(epio, MUSB_TXCSR);
423 
424 		/* NOTE host side sets DMAENAB later than this; both are
425 		 * OK since the transfer dma glue (between CPPI and Mentor
426 		 * fifos) just tells CPPI it could start.  Data only moves
427 		 * to the USB TX fifo when both fifos are ready.
428 		 */
429 
430 		/* "mode" is irrelevant here; handle terminating ZLPs like
431 		 * PIO does, since the hardware RNDIS mode seems unreliable
432 		 * except for the last-packet-is-already-short case.
433 		 */
434 		use_dma = use_dma && c->channel_program(
435 				musb_ep->dma, musb_ep->packet_sz,
436 				0,
437 				request->dma + request->actual,
438 				request_size);
439 		if (!use_dma) {
440 			c->channel_release(musb_ep->dma);
441 			musb_ep->dma = NULL;
442 			csr &= ~MUSB_TXCSR_DMAENAB;
443 			musb_writew(epio, MUSB_TXCSR, csr);
444 			/* invariant: prequest->buf is non-null */
445 		}
446 #elif defined(CONFIG_USB_TUSB_OMAP_DMA)
447 		use_dma = use_dma && c->channel_program(
448 				musb_ep->dma, musb_ep->packet_sz,
449 				request->zero,
450 				request->dma + request->actual,
451 				request_size);
452 #endif
453 	}
454 #endif
455 
456 	if (!use_dma) {
457 		/*
458 		 * Unmap the dma buffer back to cpu if dma channel
459 		 * programming fails
460 		 */
461 		unmap_dma_buffer(req, musb);
462 
463 		musb_write_fifo(musb_ep->hw_ep, fifo_count,
464 				(u8 *) (request->buf + request->actual));
465 		request->actual += fifo_count;
466 		csr |= MUSB_TXCSR_TXPKTRDY;
467 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
468 		musb_writew(epio, MUSB_TXCSR, csr);
469 	}
470 
471 	/* host may already have the data when this message shows... */
472 	DBG(3, "%s TX/IN %s len %d/%d, txcsr %04x, fifo %d/%d\n",
473 			musb_ep->end_point.name, use_dma ? "dma" : "pio",
474 			request->actual, request->length,
475 			musb_readw(epio, MUSB_TXCSR),
476 			fifo_count,
477 			musb_readw(epio, MUSB_TXMAXP));
478 }
479 
480 /*
481  * FIFO state update (e.g. data ready).
482  * Called from IRQ,  with controller locked.
483  */
musb_g_tx(struct musb * musb,u8 epnum)484 void musb_g_tx(struct musb *musb, u8 epnum)
485 {
486 	u16			csr;
487 	struct musb_request	*req;
488 	struct usb_request	*request;
489 	u8 __iomem		*mbase = musb->mregs;
490 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_in;
491 	void __iomem		*epio = musb->endpoints[epnum].regs;
492 	struct dma_channel	*dma;
493 
494 	musb_ep_select(mbase, epnum);
495 	req = next_request(musb_ep);
496 	request = &req->request;
497 
498 	csr = musb_readw(epio, MUSB_TXCSR);
499 	DBG(4, "<== %s, txcsr %04x\n", musb_ep->end_point.name, csr);
500 
501 	dma = is_dma_capable() ? musb_ep->dma : NULL;
502 
503 	/*
504 	 * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX
505 	 * probably rates reporting as a host error.
506 	 */
507 	if (csr & MUSB_TXCSR_P_SENTSTALL) {
508 		csr |=	MUSB_TXCSR_P_WZC_BITS;
509 		csr &= ~MUSB_TXCSR_P_SENTSTALL;
510 		musb_writew(epio, MUSB_TXCSR, csr);
511 		return;
512 	}
513 
514 	if (csr & MUSB_TXCSR_P_UNDERRUN) {
515 		/* We NAKed, no big deal... little reason to care. */
516 		csr |=	 MUSB_TXCSR_P_WZC_BITS;
517 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
518 		musb_writew(epio, MUSB_TXCSR, csr);
519 		DBG(20, "underrun on ep%d, req %p\n", epnum, request);
520 	}
521 
522 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
523 		/*
524 		 * SHOULD NOT HAPPEN... has with CPPI though, after
525 		 * changing SENDSTALL (and other cases); harmless?
526 		 */
527 		DBG(5, "%s dma still busy?\n", musb_ep->end_point.name);
528 		return;
529 	}
530 
531 	if (request) {
532 		u8	is_dma = 0;
533 
534 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
535 			is_dma = 1;
536 			csr |= MUSB_TXCSR_P_WZC_BITS;
537 			csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
538 				 MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET);
539 			musb_writew(epio, MUSB_TXCSR, csr);
540 			/* Ensure writebuffer is empty. */
541 			csr = musb_readw(epio, MUSB_TXCSR);
542 			request->actual += musb_ep->dma->actual_len;
543 			DBG(4, "TXCSR%d %04x, DMA off, len %zu, req %p\n",
544 				epnum, csr, musb_ep->dma->actual_len, request);
545 		}
546 
547 		/*
548 		 * First, maybe a terminating short packet. Some DMA
549 		 * engines might handle this by themselves.
550 		 */
551 		if ((request->zero && request->length
552 			&& (request->length % musb_ep->packet_sz == 0)
553 			&& (request->actual == request->length))
554 #ifdef CONFIG_USB_INVENTRA_DMA
555 			|| (is_dma && (!dma->desired_mode ||
556 				(request->actual &
557 					(musb_ep->packet_sz - 1))))
558 #endif
559 		) {
560 			/*
561 			 * On DMA completion, FIFO may not be
562 			 * available yet...
563 			 */
564 			if (csr & MUSB_TXCSR_TXPKTRDY)
565 				return;
566 
567 			DBG(4, "sending zero pkt\n");
568 			musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
569 					| MUSB_TXCSR_TXPKTRDY);
570 			request->zero = 0;
571 		}
572 
573 		if (request->actual == request->length) {
574 			musb_g_giveback(musb_ep, request, 0);
575 			req = musb_ep->desc ? next_request(musb_ep) : NULL;
576 			if (!req) {
577 				DBG(4, "%s idle now\n",
578 					musb_ep->end_point.name);
579 				return;
580 			}
581 		}
582 
583 		txstate(musb, req);
584 	}
585 }
586 
587 /* ------------------------------------------------------------ */
588 
589 #ifdef CONFIG_USB_INVENTRA_DMA
590 
591 /* Peripheral rx (OUT) using Mentor DMA works as follows:
592 	- Only mode 0 is used.
593 
594 	- Request is queued by the gadget class driver.
595 		-> if queue was previously empty, rxstate()
596 
597 	- Host sends OUT token which causes an endpoint interrupt
598 	  /\      -> RxReady
599 	  |	      -> if request queued, call rxstate
600 	  |		/\	-> setup DMA
601 	  |		|	     -> DMA interrupt on completion
602 	  |		|		-> RxReady
603 	  |		|		      -> stop DMA
604 	  |		|		      -> ack the read
605 	  |		|		      -> if data recd = max expected
606 	  |		|				by the request, or host
607 	  |		|				sent a short packet,
608 	  |		|				complete the request,
609 	  |		|				and start the next one.
610 	  |		|_____________________________________|
611 	  |					 else just wait for the host
612 	  |					    to send the next OUT token.
613 	  |__________________________________________________|
614 
615  * Non-Mentor DMA engines can of course work differently.
616  */
617 
618 #endif
619 
620 /*
621  * Context: controller locked, IRQs blocked, endpoint selected
622  */
rxstate(struct musb * musb,struct musb_request * req)623 static void rxstate(struct musb *musb, struct musb_request *req)
624 {
625 	const u8		epnum = req->epnum;
626 	struct usb_request	*request = &req->request;
627 	struct musb_ep		*musb_ep;
628 	void __iomem		*epio = musb->endpoints[epnum].regs;
629 	unsigned		fifo_count = 0;
630 	u16			len;
631 	u16			csr = musb_readw(epio, MUSB_RXCSR);
632 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
633 
634 	if (hw_ep->is_shared_fifo)
635 		musb_ep = &hw_ep->ep_in;
636 	else
637 		musb_ep = &hw_ep->ep_out;
638 
639 	len = musb_ep->packet_sz;
640 
641 	/* We shouldn't get here while DMA is active, but we do... */
642 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
643 		DBG(4, "DMA pending...\n");
644 		return;
645 	}
646 
647 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
648 		DBG(5, "%s stalling, RXCSR %04x\n",
649 		    musb_ep->end_point.name, csr);
650 		return;
651 	}
652 
653 	if (is_cppi_enabled() && is_buffer_mapped(req)) {
654 		struct dma_controller	*c = musb->dma_controller;
655 		struct dma_channel	*channel = musb_ep->dma;
656 
657 		/* NOTE:  CPPI won't actually stop advancing the DMA
658 		 * queue after short packet transfers, so this is almost
659 		 * always going to run as IRQ-per-packet DMA so that
660 		 * faults will be handled correctly.
661 		 */
662 		if (c->channel_program(channel,
663 				musb_ep->packet_sz,
664 				!request->short_not_ok,
665 				request->dma + request->actual,
666 				request->length - request->actual)) {
667 
668 			/* make sure that if an rxpkt arrived after the irq,
669 			 * the cppi engine will be ready to take it as soon
670 			 * as DMA is enabled
671 			 */
672 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
673 					| MUSB_RXCSR_DMAMODE);
674 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
675 			musb_writew(epio, MUSB_RXCSR, csr);
676 			return;
677 		}
678 	}
679 
680 	if (csr & MUSB_RXCSR_RXPKTRDY) {
681 		len = musb_readw(epio, MUSB_RXCOUNT);
682 		if (request->actual < request->length) {
683 #ifdef CONFIG_USB_INVENTRA_DMA
684 			if (is_buffer_mapped(req)) {
685 				struct dma_controller	*c;
686 				struct dma_channel	*channel;
687 				int			use_dma = 0;
688 
689 				c = musb->dma_controller;
690 				channel = musb_ep->dma;
691 
692 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
693 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
694 	 * completion. We only get interrupts from DMA controller.
695 	 *
696 	 * We could operate in DMA mode 1 if we knew the size of the tranfer
697 	 * in advance. For mass storage class, request->length = what the host
698 	 * sends, so that'd work.  But for pretty much everything else,
699 	 * request->length is routinely more than what the host sends. For
700 	 * most these gadgets, end of is signified either by a short packet,
701 	 * or filling the last byte of the buffer.  (Sending extra data in
702 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
703 	 * we don't get DMA completion interrrupt for short packets.
704 	 *
705 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
706 	 * to get endpoint interrupt on every DMA req, but that didn't seem
707 	 * to work reliably.
708 	 *
709 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
710 	 * then becomes usable as a runtime "use mode 1" hint...
711 	 */
712 
713 				csr |= MUSB_RXCSR_DMAENAB;
714 #ifdef USE_MODE1
715 				csr |= MUSB_RXCSR_AUTOCLEAR;
716 				/* csr |= MUSB_RXCSR_DMAMODE; */
717 
718 				/* this special sequence (enabling and then
719 				 * disabling MUSB_RXCSR_DMAMODE) is required
720 				 * to get DMAReq to activate
721 				 */
722 				musb_writew(epio, MUSB_RXCSR,
723 					csr | MUSB_RXCSR_DMAMODE);
724 #else
725 				if (!musb_ep->hb_mult &&
726 					musb_ep->hw_ep->rx_double_buffered)
727 					csr |= MUSB_RXCSR_AUTOCLEAR;
728 #endif
729 				musb_writew(epio, MUSB_RXCSR, csr);
730 
731 				if (request->actual < request->length) {
732 					int transfer_size = 0;
733 #ifdef USE_MODE1
734 					transfer_size = min(request->length - request->actual,
735 							channel->max_len);
736 #else
737 					transfer_size = min(request->length - request->actual,
738 							(unsigned)len);
739 #endif
740 					if (transfer_size <= musb_ep->packet_sz)
741 						musb_ep->dma->desired_mode = 0;
742 					else
743 						musb_ep->dma->desired_mode = 1;
744 
745 					use_dma = c->channel_program(
746 							channel,
747 							musb_ep->packet_sz,
748 							channel->desired_mode,
749 							request->dma
750 							+ request->actual,
751 							transfer_size);
752 				}
753 
754 				if (use_dma)
755 					return;
756 			}
757 #endif	/* Mentor's DMA */
758 
759 			fifo_count = request->length - request->actual;
760 			DBG(3, "%s OUT/RX pio fifo %d/%d, maxpacket %d\n",
761 					musb_ep->end_point.name,
762 					len, fifo_count,
763 					musb_ep->packet_sz);
764 
765 			fifo_count = min_t(unsigned, len, fifo_count);
766 
767 #ifdef	CONFIG_USB_TUSB_OMAP_DMA
768 			if (tusb_dma_omap() && is_buffer_mapped(req)) {
769 				struct dma_controller *c = musb->dma_controller;
770 				struct dma_channel *channel = musb_ep->dma;
771 				u32 dma_addr = request->dma + request->actual;
772 				int ret;
773 
774 				ret = c->channel_program(channel,
775 						musb_ep->packet_sz,
776 						channel->desired_mode,
777 						dma_addr,
778 						fifo_count);
779 				if (ret)
780 					return;
781 			}
782 #endif
783 			/*
784 			 * Unmap the dma buffer back to cpu if dma channel
785 			 * programming fails. This buffer is mapped if the
786 			 * channel allocation is successful
787 			 */
788 			 if (is_buffer_mapped(req)) {
789 				unmap_dma_buffer(req, musb);
790 
791 				/*
792 				 * Clear DMAENAB and AUTOCLEAR for the
793 				 * PIO mode transfer
794 				 */
795 				csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
796 				musb_writew(epio, MUSB_RXCSR, csr);
797 			}
798 
799 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
800 					(request->buf + request->actual));
801 			request->actual += fifo_count;
802 
803 			/* REVISIT if we left anything in the fifo, flush
804 			 * it and report -EOVERFLOW
805 			 */
806 
807 			/* ack the read! */
808 			csr |= MUSB_RXCSR_P_WZC_BITS;
809 			csr &= ~MUSB_RXCSR_RXPKTRDY;
810 			musb_writew(epio, MUSB_RXCSR, csr);
811 		}
812 	}
813 
814 	/* reach the end or short packet detected */
815 	if (request->actual == request->length || len < musb_ep->packet_sz)
816 		musb_g_giveback(musb_ep, request, 0);
817 }
818 
819 /*
820  * Data ready for a request; called from IRQ
821  */
musb_g_rx(struct musb * musb,u8 epnum)822 void musb_g_rx(struct musb *musb, u8 epnum)
823 {
824 	u16			csr;
825 	struct musb_request	*req;
826 	struct usb_request	*request;
827 	void __iomem		*mbase = musb->mregs;
828 	struct musb_ep		*musb_ep;
829 	void __iomem		*epio = musb->endpoints[epnum].regs;
830 	struct dma_channel	*dma;
831 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
832 
833 	if (hw_ep->is_shared_fifo)
834 		musb_ep = &hw_ep->ep_in;
835 	else
836 		musb_ep = &hw_ep->ep_out;
837 
838 	musb_ep_select(mbase, epnum);
839 
840 	req = next_request(musb_ep);
841 	if (!req)
842 		return;
843 
844 	request = &req->request;
845 
846 	csr = musb_readw(epio, MUSB_RXCSR);
847 	dma = is_dma_capable() ? musb_ep->dma : NULL;
848 
849 	DBG(4, "<== %s, rxcsr %04x%s %p\n", musb_ep->end_point.name,
850 			csr, dma ? " (dma)" : "", request);
851 
852 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
853 		csr |= MUSB_RXCSR_P_WZC_BITS;
854 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
855 		musb_writew(epio, MUSB_RXCSR, csr);
856 		return;
857 	}
858 
859 	if (csr & MUSB_RXCSR_P_OVERRUN) {
860 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
861 		csr &= ~MUSB_RXCSR_P_OVERRUN;
862 		musb_writew(epio, MUSB_RXCSR, csr);
863 
864 		DBG(3, "%s iso overrun on %p\n", musb_ep->name, request);
865 		if (request->status == -EINPROGRESS)
866 			request->status = -EOVERFLOW;
867 	}
868 	if (csr & MUSB_RXCSR_INCOMPRX) {
869 		/* REVISIT not necessarily an error */
870 		DBG(4, "%s, incomprx\n", musb_ep->end_point.name);
871 	}
872 
873 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
874 		/* "should not happen"; likely RXPKTRDY pending for DMA */
875 		DBG((csr & MUSB_RXCSR_DMAENAB) ? 4 : 1,
876 			"%s busy, csr %04x\n",
877 			musb_ep->end_point.name, csr);
878 		return;
879 	}
880 
881 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
882 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
883 				| MUSB_RXCSR_DMAENAB
884 				| MUSB_RXCSR_DMAMODE);
885 		musb_writew(epio, MUSB_RXCSR,
886 			MUSB_RXCSR_P_WZC_BITS | csr);
887 
888 		request->actual += musb_ep->dma->actual_len;
889 
890 		DBG(4, "RXCSR%d %04x, dma off, %04x, len %zu, req %p\n",
891 			epnum, csr,
892 			musb_readw(epio, MUSB_RXCSR),
893 			musb_ep->dma->actual_len, request);
894 
895 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA)
896 		/* Autoclear doesn't clear RxPktRdy for short packets */
897 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
898 				|| (dma->actual_len
899 					& (musb_ep->packet_sz - 1))) {
900 			/* ack the read! */
901 			csr &= ~MUSB_RXCSR_RXPKTRDY;
902 			musb_writew(epio, MUSB_RXCSR, csr);
903 		}
904 
905 		/* incomplete, and not short? wait for next IN packet */
906 		if ((request->actual < request->length)
907 				&& (musb_ep->dma->actual_len
908 					== musb_ep->packet_sz)) {
909 			/* In double buffer case, continue to unload fifo if
910  			 * there is Rx packet in FIFO.
911  			 **/
912 			csr = musb_readw(epio, MUSB_RXCSR);
913 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
914 				hw_ep->rx_double_buffered)
915 				goto exit;
916 			return;
917 		}
918 #endif
919 		musb_g_giveback(musb_ep, request, 0);
920 
921 		req = next_request(musb_ep);
922 		if (!req)
923 			return;
924 	}
925 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA)
926 exit:
927 #endif
928 	/* Analyze request */
929 	rxstate(musb, req);
930 }
931 
932 /* ------------------------------------------------------------ */
933 
musb_gadget_enable(struct usb_ep * ep,const struct usb_endpoint_descriptor * desc)934 static int musb_gadget_enable(struct usb_ep *ep,
935 			const struct usb_endpoint_descriptor *desc)
936 {
937 	unsigned long		flags;
938 	struct musb_ep		*musb_ep;
939 	struct musb_hw_ep	*hw_ep;
940 	void __iomem		*regs;
941 	struct musb		*musb;
942 	void __iomem	*mbase;
943 	u8		epnum;
944 	u16		csr;
945 	unsigned	tmp;
946 	int		status = -EINVAL;
947 
948 	if (!ep || !desc)
949 		return -EINVAL;
950 
951 	musb_ep = to_musb_ep(ep);
952 	hw_ep = musb_ep->hw_ep;
953 	regs = hw_ep->regs;
954 	musb = musb_ep->musb;
955 	mbase = musb->mregs;
956 	epnum = musb_ep->current_epnum;
957 
958 	spin_lock_irqsave(&musb->lock, flags);
959 
960 	if (musb_ep->desc) {
961 		status = -EBUSY;
962 		goto fail;
963 	}
964 	musb_ep->type = usb_endpoint_type(desc);
965 
966 	/* check direction and (later) maxpacket size against endpoint */
967 	if (usb_endpoint_num(desc) != epnum)
968 		goto fail;
969 
970 	/* REVISIT this rules out high bandwidth periodic transfers */
971 	tmp = le16_to_cpu(desc->wMaxPacketSize);
972 	if (tmp & ~0x07ff) {
973 		int ok;
974 
975 		if (usb_endpoint_dir_in(desc))
976 			ok = musb->hb_iso_tx;
977 		else
978 			ok = musb->hb_iso_rx;
979 
980 		if (!ok) {
981 			DBG(4, "no support for high bandwidth ISO\n");
982 			goto fail;
983 		}
984 		musb_ep->hb_mult = (tmp >> 11) & 3;
985 	} else {
986 		musb_ep->hb_mult = 0;
987 	}
988 
989 	musb_ep->packet_sz = tmp & 0x7ff;
990 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
991 
992 	/* enable the interrupts for the endpoint, set the endpoint
993 	 * packet size (or fail), set the mode, clear the fifo
994 	 */
995 	musb_ep_select(mbase, epnum);
996 	if (usb_endpoint_dir_in(desc)) {
997 		u16 int_txe = musb_readw(mbase, MUSB_INTRTXE);
998 
999 		if (hw_ep->is_shared_fifo)
1000 			musb_ep->is_in = 1;
1001 		if (!musb_ep->is_in)
1002 			goto fail;
1003 
1004 		if (tmp > hw_ep->max_packet_sz_tx) {
1005 			DBG(4, "packet size beyond hardware FIFO size\n");
1006 			goto fail;
1007 		}
1008 
1009 		int_txe |= (1 << epnum);
1010 		musb_writew(mbase, MUSB_INTRTXE, int_txe);
1011 
1012 		/* REVISIT if can_bulk_split(), use by updating "tmp";
1013 		 * likewise high bandwidth periodic tx
1014 		 */
1015 		/* Set TXMAXP with the FIFO size of the endpoint
1016 		 * to disable double buffering mode.
1017 		 */
1018 		if (musb->double_buffer_not_ok)
1019 			musb_writew(regs, MUSB_TXMAXP, hw_ep->max_packet_sz_tx);
1020 		else
1021 			musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
1022 					| (musb_ep->hb_mult << 11));
1023 
1024 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
1025 		if (musb_readw(regs, MUSB_TXCSR)
1026 				& MUSB_TXCSR_FIFONOTEMPTY)
1027 			csr |= MUSB_TXCSR_FLUSHFIFO;
1028 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1029 			csr |= MUSB_TXCSR_P_ISO;
1030 
1031 		/* set twice in case of double buffering */
1032 		musb_writew(regs, MUSB_TXCSR, csr);
1033 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1034 		musb_writew(regs, MUSB_TXCSR, csr);
1035 
1036 	} else {
1037 		u16 int_rxe = musb_readw(mbase, MUSB_INTRRXE);
1038 
1039 		if (hw_ep->is_shared_fifo)
1040 			musb_ep->is_in = 0;
1041 		if (musb_ep->is_in)
1042 			goto fail;
1043 
1044 		if (tmp > hw_ep->max_packet_sz_rx) {
1045 			DBG(4, "packet size beyond hardware FIFO size\n");
1046 			goto fail;
1047 		}
1048 
1049 		int_rxe |= (1 << epnum);
1050 		musb_writew(mbase, MUSB_INTRRXE, int_rxe);
1051 
1052 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1053 		 * likewise high bandwidth periodic rx
1054 		 */
1055 		/* Set RXMAXP with the FIFO size of the endpoint
1056 		 * to disable double buffering mode.
1057 		 */
1058 		if (musb->double_buffer_not_ok)
1059 			musb_writew(regs, MUSB_RXMAXP, hw_ep->max_packet_sz_tx);
1060 		else
1061 			musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1062 					| (musb_ep->hb_mult << 11));
1063 
1064 		/* force shared fifo to OUT-only mode */
1065 		if (hw_ep->is_shared_fifo) {
1066 			csr = musb_readw(regs, MUSB_TXCSR);
1067 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1068 			musb_writew(regs, MUSB_TXCSR, csr);
1069 		}
1070 
1071 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1072 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1073 			csr |= MUSB_RXCSR_P_ISO;
1074 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1075 			csr |= MUSB_RXCSR_DISNYET;
1076 
1077 		/* set twice in case of double buffering */
1078 		musb_writew(regs, MUSB_RXCSR, csr);
1079 		musb_writew(regs, MUSB_RXCSR, csr);
1080 	}
1081 
1082 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1083 	 * for some reason you run out of channels here.
1084 	 */
1085 	if (is_dma_capable() && musb->dma_controller) {
1086 		struct dma_controller	*c = musb->dma_controller;
1087 
1088 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1089 				(desc->bEndpointAddress & USB_DIR_IN));
1090 	} else
1091 		musb_ep->dma = NULL;
1092 
1093 	musb_ep->desc = desc;
1094 	musb_ep->busy = 0;
1095 	musb_ep->wedged = 0;
1096 	status = 0;
1097 
1098 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1099 			musb_driver_name, musb_ep->end_point.name,
1100 			({ char *s; switch (musb_ep->type) {
1101 			case USB_ENDPOINT_XFER_BULK:	s = "bulk"; break;
1102 			case USB_ENDPOINT_XFER_INT:	s = "int"; break;
1103 			default:			s = "iso"; break;
1104 			}; s; }),
1105 			musb_ep->is_in ? "IN" : "OUT",
1106 			musb_ep->dma ? "dma, " : "",
1107 			musb_ep->packet_sz);
1108 
1109 	schedule_work(&musb->irq_work);
1110 
1111 fail:
1112 	spin_unlock_irqrestore(&musb->lock, flags);
1113 	return status;
1114 }
1115 
1116 /*
1117  * Disable an endpoint flushing all requests queued.
1118  */
musb_gadget_disable(struct usb_ep * ep)1119 static int musb_gadget_disable(struct usb_ep *ep)
1120 {
1121 	unsigned long	flags;
1122 	struct musb	*musb;
1123 	u8		epnum;
1124 	struct musb_ep	*musb_ep;
1125 	void __iomem	*epio;
1126 	int		status = 0;
1127 
1128 	musb_ep = to_musb_ep(ep);
1129 	musb = musb_ep->musb;
1130 	epnum = musb_ep->current_epnum;
1131 	epio = musb->endpoints[epnum].regs;
1132 
1133 	spin_lock_irqsave(&musb->lock, flags);
1134 	musb_ep_select(musb->mregs, epnum);
1135 
1136 	/* zero the endpoint sizes */
1137 	if (musb_ep->is_in) {
1138 		u16 int_txe = musb_readw(musb->mregs, MUSB_INTRTXE);
1139 		int_txe &= ~(1 << epnum);
1140 		musb_writew(musb->mregs, MUSB_INTRTXE, int_txe);
1141 		musb_writew(epio, MUSB_TXMAXP, 0);
1142 	} else {
1143 		u16 int_rxe = musb_readw(musb->mregs, MUSB_INTRRXE);
1144 		int_rxe &= ~(1 << epnum);
1145 		musb_writew(musb->mregs, MUSB_INTRRXE, int_rxe);
1146 		musb_writew(epio, MUSB_RXMAXP, 0);
1147 	}
1148 
1149 	musb_ep->desc = NULL;
1150 
1151 	/* abort all pending DMA and requests */
1152 	nuke(musb_ep, -ESHUTDOWN);
1153 
1154 	schedule_work(&musb->irq_work);
1155 
1156 	spin_unlock_irqrestore(&(musb->lock), flags);
1157 
1158 	DBG(2, "%s\n", musb_ep->end_point.name);
1159 
1160 	return status;
1161 }
1162 
1163 /*
1164  * Allocate a request for an endpoint.
1165  * Reused by ep0 code.
1166  */
musb_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)1167 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1168 {
1169 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1170 	struct musb_request	*request = NULL;
1171 
1172 	request = kzalloc(sizeof *request, gfp_flags);
1173 	if (!request) {
1174 		DBG(4, "not enough memory\n");
1175 		return NULL;
1176 	}
1177 
1178 	request->request.dma = DMA_ADDR_INVALID;
1179 	request->epnum = musb_ep->current_epnum;
1180 	request->ep = musb_ep;
1181 
1182 	return &request->request;
1183 }
1184 
1185 /*
1186  * Free a request
1187  * Reused by ep0 code.
1188  */
musb_free_request(struct usb_ep * ep,struct usb_request * req)1189 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1190 {
1191 	kfree(to_musb_request(req));
1192 }
1193 
1194 static LIST_HEAD(buffers);
1195 
1196 struct free_record {
1197 	struct list_head	list;
1198 	struct device		*dev;
1199 	unsigned		bytes;
1200 	dma_addr_t		dma;
1201 };
1202 
1203 /*
1204  * Context: controller locked, IRQs blocked.
1205  */
musb_ep_restart(struct musb * musb,struct musb_request * req)1206 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1207 {
1208 	DBG(3, "<== %s request %p len %u on hw_ep%d\n",
1209 		req->tx ? "TX/IN" : "RX/OUT",
1210 		&req->request, req->request.length, req->epnum);
1211 
1212 	musb_ep_select(musb->mregs, req->epnum);
1213 	if (req->tx)
1214 		txstate(musb, req);
1215 	else
1216 		rxstate(musb, req);
1217 }
1218 
musb_gadget_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)1219 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1220 			gfp_t gfp_flags)
1221 {
1222 	struct musb_ep		*musb_ep;
1223 	struct musb_request	*request;
1224 	struct musb		*musb;
1225 	int			status = 0;
1226 	unsigned long		lockflags;
1227 
1228 	if (!ep || !req)
1229 		return -EINVAL;
1230 	if (!req->buf)
1231 		return -ENODATA;
1232 
1233 	musb_ep = to_musb_ep(ep);
1234 	musb = musb_ep->musb;
1235 
1236 	request = to_musb_request(req);
1237 	request->musb = musb;
1238 
1239 	if (request->ep != musb_ep)
1240 		return -EINVAL;
1241 
1242 	DBG(4, "<== to %s request=%p\n", ep->name, req);
1243 
1244 	/* request is mine now... */
1245 	request->request.actual = 0;
1246 	request->request.status = -EINPROGRESS;
1247 	request->epnum = musb_ep->current_epnum;
1248 	request->tx = musb_ep->is_in;
1249 
1250 	map_dma_buffer(request, musb, musb_ep);
1251 
1252 	spin_lock_irqsave(&musb->lock, lockflags);
1253 
1254 	/* don't queue if the ep is down */
1255 	if (!musb_ep->desc) {
1256 		DBG(4, "req %p queued to %s while ep %s\n",
1257 				req, ep->name, "disabled");
1258 		status = -ESHUTDOWN;
1259 		goto cleanup;
1260 	}
1261 
1262 	/* add request to the list */
1263 	list_add_tail(&request->list, &musb_ep->req_list);
1264 
1265 	/* it this is the head of the queue, start i/o ... */
1266 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next)
1267 		musb_ep_restart(musb, request);
1268 
1269 cleanup:
1270 	spin_unlock_irqrestore(&musb->lock, lockflags);
1271 	return status;
1272 }
1273 
musb_gadget_dequeue(struct usb_ep * ep,struct usb_request * request)1274 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1275 {
1276 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1277 	struct musb_request	*req = to_musb_request(request);
1278 	struct musb_request	*r;
1279 	unsigned long		flags;
1280 	int			status = 0;
1281 	struct musb		*musb = musb_ep->musb;
1282 
1283 	if (!ep || !request || to_musb_request(request)->ep != musb_ep)
1284 		return -EINVAL;
1285 
1286 	spin_lock_irqsave(&musb->lock, flags);
1287 
1288 	list_for_each_entry(r, &musb_ep->req_list, list) {
1289 		if (r == req)
1290 			break;
1291 	}
1292 	if (r != req) {
1293 		DBG(3, "request %p not queued to %s\n", request, ep->name);
1294 		status = -EINVAL;
1295 		goto done;
1296 	}
1297 
1298 	/* if the hardware doesn't have the request, easy ... */
1299 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1300 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1301 
1302 	/* ... else abort the dma transfer ... */
1303 	else if (is_dma_capable() && musb_ep->dma) {
1304 		struct dma_controller	*c = musb->dma_controller;
1305 
1306 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1307 		if (c->channel_abort)
1308 			status = c->channel_abort(musb_ep->dma);
1309 		else
1310 			status = -EBUSY;
1311 		if (status == 0)
1312 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1313 	} else {
1314 		/* NOTE: by sticking to easily tested hardware/driver states,
1315 		 * we leave counting of in-flight packets imprecise.
1316 		 */
1317 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1318 	}
1319 
1320 done:
1321 	spin_unlock_irqrestore(&musb->lock, flags);
1322 	return status;
1323 }
1324 
1325 /*
1326  * Set or clear the halt bit of an endpoint. A halted enpoint won't tx/rx any
1327  * data but will queue requests.
1328  *
1329  * exported to ep0 code
1330  */
musb_gadget_set_halt(struct usb_ep * ep,int value)1331 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1332 {
1333 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1334 	u8			epnum = musb_ep->current_epnum;
1335 	struct musb		*musb = musb_ep->musb;
1336 	void __iomem		*epio = musb->endpoints[epnum].regs;
1337 	void __iomem		*mbase;
1338 	unsigned long		flags;
1339 	u16			csr;
1340 	struct musb_request	*request;
1341 	int			status = 0;
1342 
1343 	if (!ep)
1344 		return -EINVAL;
1345 	mbase = musb->mregs;
1346 
1347 	spin_lock_irqsave(&musb->lock, flags);
1348 
1349 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1350 		status = -EINVAL;
1351 		goto done;
1352 	}
1353 
1354 	musb_ep_select(mbase, epnum);
1355 
1356 	request = next_request(musb_ep);
1357 	if (value) {
1358 		if (request) {
1359 			DBG(3, "request in progress, cannot halt %s\n",
1360 			    ep->name);
1361 			status = -EAGAIN;
1362 			goto done;
1363 		}
1364 		/* Cannot portably stall with non-empty FIFO */
1365 		if (musb_ep->is_in) {
1366 			csr = musb_readw(epio, MUSB_TXCSR);
1367 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1368 				DBG(3, "FIFO busy, cannot halt %s\n", ep->name);
1369 				status = -EAGAIN;
1370 				goto done;
1371 			}
1372 		}
1373 	} else
1374 		musb_ep->wedged = 0;
1375 
1376 	/* set/clear the stall and toggle bits */
1377 	DBG(2, "%s: %s stall\n", ep->name, value ? "set" : "clear");
1378 	if (musb_ep->is_in) {
1379 		csr = musb_readw(epio, MUSB_TXCSR);
1380 		csr |= MUSB_TXCSR_P_WZC_BITS
1381 			| MUSB_TXCSR_CLRDATATOG;
1382 		if (value)
1383 			csr |= MUSB_TXCSR_P_SENDSTALL;
1384 		else
1385 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1386 				| MUSB_TXCSR_P_SENTSTALL);
1387 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1388 		musb_writew(epio, MUSB_TXCSR, csr);
1389 	} else {
1390 		csr = musb_readw(epio, MUSB_RXCSR);
1391 		csr |= MUSB_RXCSR_P_WZC_BITS
1392 			| MUSB_RXCSR_FLUSHFIFO
1393 			| MUSB_RXCSR_CLRDATATOG;
1394 		if (value)
1395 			csr |= MUSB_RXCSR_P_SENDSTALL;
1396 		else
1397 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1398 				| MUSB_RXCSR_P_SENTSTALL);
1399 		musb_writew(epio, MUSB_RXCSR, csr);
1400 	}
1401 
1402 	/* maybe start the first request in the queue */
1403 	if (!musb_ep->busy && !value && request) {
1404 		DBG(3, "restarting the request\n");
1405 		musb_ep_restart(musb, request);
1406 	}
1407 
1408 done:
1409 	spin_unlock_irqrestore(&musb->lock, flags);
1410 	return status;
1411 }
1412 
1413 /*
1414  * Sets the halt feature with the clear requests ignored
1415  */
musb_gadget_set_wedge(struct usb_ep * ep)1416 static int musb_gadget_set_wedge(struct usb_ep *ep)
1417 {
1418 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1419 
1420 	if (!ep)
1421 		return -EINVAL;
1422 
1423 	musb_ep->wedged = 1;
1424 
1425 	return usb_ep_set_halt(ep);
1426 }
1427 
musb_gadget_fifo_status(struct usb_ep * ep)1428 static int musb_gadget_fifo_status(struct usb_ep *ep)
1429 {
1430 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1431 	void __iomem		*epio = musb_ep->hw_ep->regs;
1432 	int			retval = -EINVAL;
1433 
1434 	if (musb_ep->desc && !musb_ep->is_in) {
1435 		struct musb		*musb = musb_ep->musb;
1436 		int			epnum = musb_ep->current_epnum;
1437 		void __iomem		*mbase = musb->mregs;
1438 		unsigned long		flags;
1439 
1440 		spin_lock_irqsave(&musb->lock, flags);
1441 
1442 		musb_ep_select(mbase, epnum);
1443 		/* FIXME return zero unless RXPKTRDY is set */
1444 		retval = musb_readw(epio, MUSB_RXCOUNT);
1445 
1446 		spin_unlock_irqrestore(&musb->lock, flags);
1447 	}
1448 	return retval;
1449 }
1450 
musb_gadget_fifo_flush(struct usb_ep * ep)1451 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1452 {
1453 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1454 	struct musb	*musb = musb_ep->musb;
1455 	u8		epnum = musb_ep->current_epnum;
1456 	void __iomem	*epio = musb->endpoints[epnum].regs;
1457 	void __iomem	*mbase;
1458 	unsigned long	flags;
1459 	u16		csr, int_txe;
1460 
1461 	mbase = musb->mregs;
1462 
1463 	spin_lock_irqsave(&musb->lock, flags);
1464 	musb_ep_select(mbase, (u8) epnum);
1465 
1466 	/* disable interrupts */
1467 	int_txe = musb_readw(mbase, MUSB_INTRTXE);
1468 	musb_writew(mbase, MUSB_INTRTXE, int_txe & ~(1 << epnum));
1469 
1470 	if (musb_ep->is_in) {
1471 		csr = musb_readw(epio, MUSB_TXCSR);
1472 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1473 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1474 			musb_writew(epio, MUSB_TXCSR, csr);
1475 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1476 			musb_writew(epio, MUSB_TXCSR, csr);
1477 		}
1478 	} else {
1479 		csr = musb_readw(epio, MUSB_RXCSR);
1480 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1481 		musb_writew(epio, MUSB_RXCSR, csr);
1482 		musb_writew(epio, MUSB_RXCSR, csr);
1483 	}
1484 
1485 	/* re-enable interrupt */
1486 	musb_writew(mbase, MUSB_INTRTXE, int_txe);
1487 	spin_unlock_irqrestore(&musb->lock, flags);
1488 }
1489 
1490 static const struct usb_ep_ops musb_ep_ops = {
1491 	.enable		= musb_gadget_enable,
1492 	.disable	= musb_gadget_disable,
1493 	.alloc_request	= musb_alloc_request,
1494 	.free_request	= musb_free_request,
1495 	.queue		= musb_gadget_queue,
1496 	.dequeue	= musb_gadget_dequeue,
1497 	.set_halt	= musb_gadget_set_halt,
1498 	.set_wedge	= musb_gadget_set_wedge,
1499 	.fifo_status	= musb_gadget_fifo_status,
1500 	.fifo_flush	= musb_gadget_fifo_flush
1501 };
1502 
1503 /* ----------------------------------------------------------------------- */
1504 
musb_gadget_get_frame(struct usb_gadget * gadget)1505 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1506 {
1507 	struct musb	*musb = gadget_to_musb(gadget);
1508 
1509 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1510 }
1511 
musb_gadget_wakeup(struct usb_gadget * gadget)1512 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1513 {
1514 	struct musb	*musb = gadget_to_musb(gadget);
1515 	void __iomem	*mregs = musb->mregs;
1516 	unsigned long	flags;
1517 	int		status = -EINVAL;
1518 	u8		power, devctl;
1519 	int		retries;
1520 
1521 	spin_lock_irqsave(&musb->lock, flags);
1522 
1523 	switch (musb->xceiv->state) {
1524 	case OTG_STATE_B_PERIPHERAL:
1525 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1526 		 * that's part of the standard usb 1.1 state machine, and
1527 		 * doesn't affect OTG transitions.
1528 		 */
1529 		if (musb->may_wakeup && musb->is_suspended)
1530 			break;
1531 		goto done;
1532 	case OTG_STATE_B_IDLE:
1533 		/* Start SRP ... OTG not required. */
1534 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1535 		DBG(2, "Sending SRP: devctl: %02x\n", devctl);
1536 		devctl |= MUSB_DEVCTL_SESSION;
1537 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1538 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1539 		retries = 100;
1540 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1541 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1542 			if (retries-- < 1)
1543 				break;
1544 		}
1545 		retries = 10000;
1546 		while (devctl & MUSB_DEVCTL_SESSION) {
1547 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1548 			if (retries-- < 1)
1549 				break;
1550 		}
1551 
1552 		/* Block idling for at least 1s */
1553 		musb_platform_try_idle(musb,
1554 			jiffies + msecs_to_jiffies(1 * HZ));
1555 
1556 		status = 0;
1557 		goto done;
1558 	default:
1559 		DBG(2, "Unhandled wake: %s\n", otg_state_string(musb));
1560 		goto done;
1561 	}
1562 
1563 	status = 0;
1564 
1565 	power = musb_readb(mregs, MUSB_POWER);
1566 	power |= MUSB_POWER_RESUME;
1567 	musb_writeb(mregs, MUSB_POWER, power);
1568 	DBG(2, "issue wakeup\n");
1569 
1570 	/* FIXME do this next chunk in a timer callback, no udelay */
1571 	mdelay(2);
1572 
1573 	power = musb_readb(mregs, MUSB_POWER);
1574 	power &= ~MUSB_POWER_RESUME;
1575 	musb_writeb(mregs, MUSB_POWER, power);
1576 done:
1577 	spin_unlock_irqrestore(&musb->lock, flags);
1578 	return status;
1579 }
1580 
1581 static int
musb_gadget_set_self_powered(struct usb_gadget * gadget,int is_selfpowered)1582 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1583 {
1584 	struct musb	*musb = gadget_to_musb(gadget);
1585 
1586 	musb->is_self_powered = !!is_selfpowered;
1587 	return 0;
1588 }
1589 
musb_pullup(struct musb * musb,int is_on)1590 static void musb_pullup(struct musb *musb, int is_on)
1591 {
1592 	u8 power;
1593 
1594 	power = musb_readb(musb->mregs, MUSB_POWER);
1595 	if (is_on)
1596 		power |= MUSB_POWER_SOFTCONN;
1597 	else
1598 		power &= ~MUSB_POWER_SOFTCONN;
1599 
1600 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1601 
1602 	DBG(3, "gadget %s D+ pullup %s\n",
1603 		musb->gadget_driver->function, is_on ? "on" : "off");
1604 	musb_writeb(musb->mregs, MUSB_POWER, power);
1605 }
1606 
1607 #if 0
1608 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1609 {
1610 	DBG(2, "<= %s =>\n", __func__);
1611 
1612 	/*
1613 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1614 	 * though that can clear it), just musb_pullup().
1615 	 */
1616 
1617 	return -EINVAL;
1618 }
1619 #endif
1620 
musb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)1621 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1622 {
1623 	struct musb	*musb = gadget_to_musb(gadget);
1624 
1625 	if (!musb->xceiv->set_power)
1626 		return -EOPNOTSUPP;
1627 	return otg_set_power(musb->xceiv, mA);
1628 }
1629 
musb_gadget_pullup(struct usb_gadget * gadget,int is_on)1630 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1631 {
1632 	struct musb	*musb = gadget_to_musb(gadget);
1633 	unsigned long	flags;
1634 
1635 	is_on = !!is_on;
1636 
1637 	/* NOTE: this assumes we are sensing vbus; we'd rather
1638 	 * not pullup unless the B-session is active.
1639 	 */
1640 	spin_lock_irqsave(&musb->lock, flags);
1641 	if (is_on != musb->softconnect) {
1642 		musb->softconnect = is_on;
1643 		musb_pullup(musb, is_on);
1644 	}
1645 	spin_unlock_irqrestore(&musb->lock, flags);
1646 	return 0;
1647 }
1648 
1649 static const struct usb_gadget_ops musb_gadget_operations = {
1650 	.get_frame		= musb_gadget_get_frame,
1651 	.wakeup			= musb_gadget_wakeup,
1652 	.set_selfpowered	= musb_gadget_set_self_powered,
1653 	/* .vbus_session		= musb_gadget_vbus_session, */
1654 	.vbus_draw		= musb_gadget_vbus_draw,
1655 	.pullup			= musb_gadget_pullup,
1656 };
1657 
1658 /* ----------------------------------------------------------------------- */
1659 
1660 /* Registration */
1661 
1662 /* Only this registration code "knows" the rule (from USB standards)
1663  * about there being only one external upstream port.  It assumes
1664  * all peripheral ports are external...
1665  */
1666 static struct musb *the_gadget;
1667 
musb_gadget_release(struct device * dev)1668 static void musb_gadget_release(struct device *dev)
1669 {
1670 	/* kref_put(WHAT) */
1671 	dev_dbg(dev, "%s\n", __func__);
1672 }
1673 
1674 
1675 static void __init
init_peripheral_ep(struct musb * musb,struct musb_ep * ep,u8 epnum,int is_in)1676 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1677 {
1678 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1679 
1680 	memset(ep, 0, sizeof *ep);
1681 
1682 	ep->current_epnum = epnum;
1683 	ep->musb = musb;
1684 	ep->hw_ep = hw_ep;
1685 	ep->is_in = is_in;
1686 
1687 	INIT_LIST_HEAD(&ep->req_list);
1688 
1689 	sprintf(ep->name, "ep%d%s", epnum,
1690 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1691 				is_in ? "in" : "out"));
1692 	ep->end_point.name = ep->name;
1693 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1694 	if (!epnum) {
1695 		ep->end_point.maxpacket = 64;
1696 		ep->end_point.ops = &musb_g_ep0_ops;
1697 		musb->g.ep0 = &ep->end_point;
1698 	} else {
1699 		if (is_in)
1700 			ep->end_point.maxpacket = hw_ep->max_packet_sz_tx;
1701 		else
1702 			ep->end_point.maxpacket = hw_ep->max_packet_sz_rx;
1703 		ep->end_point.ops = &musb_ep_ops;
1704 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1705 	}
1706 }
1707 
1708 /*
1709  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1710  * to the rest of the driver state.
1711  */
musb_g_init_endpoints(struct musb * musb)1712 static inline void __init musb_g_init_endpoints(struct musb *musb)
1713 {
1714 	u8			epnum;
1715 	struct musb_hw_ep	*hw_ep;
1716 	unsigned		count = 0;
1717 
1718 	/* initialize endpoint list just once */
1719 	INIT_LIST_HEAD(&(musb->g.ep_list));
1720 
1721 	for (epnum = 0, hw_ep = musb->endpoints;
1722 			epnum < musb->nr_endpoints;
1723 			epnum++, hw_ep++) {
1724 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1725 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1726 			count++;
1727 		} else {
1728 			if (hw_ep->max_packet_sz_tx) {
1729 				init_peripheral_ep(musb, &hw_ep->ep_in,
1730 							epnum, 1);
1731 				count++;
1732 			}
1733 			if (hw_ep->max_packet_sz_rx) {
1734 				init_peripheral_ep(musb, &hw_ep->ep_out,
1735 							epnum, 0);
1736 				count++;
1737 			}
1738 		}
1739 	}
1740 }
1741 
1742 /* called once during driver setup to initialize and link into
1743  * the driver model; memory is zeroed.
1744  */
musb_gadget_setup(struct musb * musb)1745 int __init musb_gadget_setup(struct musb *musb)
1746 {
1747 	int status;
1748 
1749 	/* REVISIT minor race:  if (erroneously) setting up two
1750 	 * musb peripherals at the same time, only the bus lock
1751 	 * is probably held.
1752 	 */
1753 	if (the_gadget)
1754 		return -EBUSY;
1755 	the_gadget = musb;
1756 
1757 	musb->g.ops = &musb_gadget_operations;
1758 	musb->g.is_dualspeed = 1;
1759 	musb->g.speed = USB_SPEED_UNKNOWN;
1760 
1761 	/* this "gadget" abstracts/virtualizes the controller */
1762 	dev_set_name(&musb->g.dev, "gadget");
1763 	musb->g.dev.parent = musb->controller;
1764 	musb->g.dev.dma_mask = musb->controller->dma_mask;
1765 	musb->g.dev.release = musb_gadget_release;
1766 	musb->g.name = musb_driver_name;
1767 
1768 	if (is_otg_enabled(musb))
1769 		musb->g.is_otg = 1;
1770 
1771 	musb_g_init_endpoints(musb);
1772 
1773 	musb->is_active = 0;
1774 	musb_platform_try_idle(musb, 0);
1775 
1776 	status = device_register(&musb->g.dev);
1777 	if (status != 0) {
1778 		put_device(&musb->g.dev);
1779 		the_gadget = NULL;
1780 	}
1781 	return status;
1782 }
1783 
musb_gadget_cleanup(struct musb * musb)1784 void musb_gadget_cleanup(struct musb *musb)
1785 {
1786 	if (musb != the_gadget)
1787 		return;
1788 
1789 	device_unregister(&musb->g.dev);
1790 	the_gadget = NULL;
1791 }
1792 
1793 /*
1794  * Register the gadget driver. Used by gadget drivers when
1795  * registering themselves with the controller.
1796  *
1797  * -EINVAL something went wrong (not driver)
1798  * -EBUSY another gadget is already using the controller
1799  * -ENOMEM no memory to perform the operation
1800  *
1801  * @param driver the gadget driver
1802  * @param bind the driver's bind function
1803  * @return <0 if error, 0 if everything is fine
1804  */
usb_gadget_probe_driver(struct usb_gadget_driver * driver,int (* bind)(struct usb_gadget *))1805 int usb_gadget_probe_driver(struct usb_gadget_driver *driver,
1806 		int (*bind)(struct usb_gadget *))
1807 {
1808 	struct musb		*musb = the_gadget;
1809 	unsigned long		flags;
1810 	int			retval = -EINVAL;
1811 
1812 	if (!driver
1813 			|| driver->speed != USB_SPEED_HIGH
1814 			|| !bind || !driver->setup)
1815 		goto err0;
1816 
1817 	/* driver must be initialized to support peripheral mode */
1818 	if (!musb) {
1819 		DBG(1, "no dev??\n");
1820 		retval = -ENODEV;
1821 		goto err0;
1822 	}
1823 
1824 	pm_runtime_get_sync(musb->controller);
1825 
1826 	DBG(3, "registering driver %s\n", driver->function);
1827 
1828 	if (musb->gadget_driver) {
1829 		DBG(1, "%s is already bound to %s\n",
1830 				musb_driver_name,
1831 				musb->gadget_driver->driver.name);
1832 		retval = -EBUSY;
1833 		goto err0;
1834 	}
1835 
1836 	spin_lock_irqsave(&musb->lock, flags);
1837 	musb->gadget_driver = driver;
1838 	musb->g.dev.driver = &driver->driver;
1839 	driver->driver.bus = NULL;
1840 	musb->softconnect = 1;
1841 	spin_unlock_irqrestore(&musb->lock, flags);
1842 
1843 	retval = bind(&musb->g);
1844 	if (retval) {
1845 		DBG(3, "bind to driver %s failed --> %d\n",
1846 				driver->driver.name, retval);
1847 		goto err1;
1848 	}
1849 
1850 	spin_lock_irqsave(&musb->lock, flags);
1851 
1852 	otg_set_peripheral(musb->xceiv, &musb->g);
1853 	musb->xceiv->state = OTG_STATE_B_IDLE;
1854 	musb->is_active = 1;
1855 
1856 	/*
1857 	 * FIXME this ignores the softconnect flag.  Drivers are
1858 	 * allowed hold the peripheral inactive until for example
1859 	 * userspace hooks up printer hardware or DSP codecs, so
1860 	 * hosts only see fully functional devices.
1861 	 */
1862 
1863 	if (!is_otg_enabled(musb))
1864 		musb_start(musb);
1865 
1866 	otg_set_peripheral(musb->xceiv, &musb->g);
1867 
1868 	spin_unlock_irqrestore(&musb->lock, flags);
1869 
1870 	if (is_otg_enabled(musb)) {
1871 		struct usb_hcd	*hcd = musb_to_hcd(musb);
1872 
1873 		DBG(3, "OTG startup...\n");
1874 
1875 		/* REVISIT:  funcall to other code, which also
1876 		 * handles power budgeting ... this way also
1877 		 * ensures HdrcStart is indirectly called.
1878 		 */
1879 		retval = usb_add_hcd(musb_to_hcd(musb), -1, 0);
1880 		if (retval < 0) {
1881 			DBG(1, "add_hcd failed, %d\n", retval);
1882 			goto err2;
1883 		}
1884 
1885 		if ((musb->xceiv->last_event == USB_EVENT_ID)
1886 					&& musb->xceiv->set_vbus)
1887 			otg_set_vbus(musb->xceiv, 1);
1888 
1889 		hcd->self.uses_pio_for_control = 1;
1890 	}
1891 	if (musb->xceiv->last_event == USB_EVENT_NONE)
1892 		pm_runtime_put(musb->controller);
1893 
1894 	return 0;
1895 
1896 err2:
1897 	if (!is_otg_enabled(musb))
1898 		musb_stop(musb);
1899 
1900 err1:
1901 	musb->gadget_driver = NULL;
1902 	musb->g.dev.driver = NULL;
1903 
1904 err0:
1905 	return retval;
1906 }
1907 EXPORT_SYMBOL(usb_gadget_probe_driver);
1908 
stop_activity(struct musb * musb,struct usb_gadget_driver * driver)1909 static void stop_activity(struct musb *musb, struct usb_gadget_driver *driver)
1910 {
1911 	int			i;
1912 	struct musb_hw_ep	*hw_ep;
1913 
1914 	/* don't disconnect if it's not connected */
1915 	if (musb->g.speed == USB_SPEED_UNKNOWN)
1916 		driver = NULL;
1917 	else
1918 		musb->g.speed = USB_SPEED_UNKNOWN;
1919 
1920 	/* deactivate the hardware */
1921 	if (musb->softconnect) {
1922 		musb->softconnect = 0;
1923 		musb_pullup(musb, 0);
1924 	}
1925 	musb_stop(musb);
1926 
1927 	/* killing any outstanding requests will quiesce the driver;
1928 	 * then report disconnect
1929 	 */
1930 	if (driver) {
1931 		for (i = 0, hw_ep = musb->endpoints;
1932 				i < musb->nr_endpoints;
1933 				i++, hw_ep++) {
1934 			musb_ep_select(musb->mregs, i);
1935 			if (hw_ep->is_shared_fifo /* || !epnum */) {
1936 				nuke(&hw_ep->ep_in, -ESHUTDOWN);
1937 			} else {
1938 				if (hw_ep->max_packet_sz_tx)
1939 					nuke(&hw_ep->ep_in, -ESHUTDOWN);
1940 				if (hw_ep->max_packet_sz_rx)
1941 					nuke(&hw_ep->ep_out, -ESHUTDOWN);
1942 			}
1943 		}
1944 
1945 		spin_unlock(&musb->lock);
1946 		driver->disconnect(&musb->g);
1947 		spin_lock(&musb->lock);
1948 	}
1949 }
1950 
1951 /*
1952  * Unregister the gadget driver. Used by gadget drivers when
1953  * unregistering themselves from the controller.
1954  *
1955  * @param driver the gadget driver to unregister
1956  */
usb_gadget_unregister_driver(struct usb_gadget_driver * driver)1957 int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
1958 {
1959 	struct musb	*musb = the_gadget;
1960 	unsigned long	flags;
1961 
1962 	if (!driver || !driver->unbind || !musb)
1963 		return -EINVAL;
1964 
1965 	if (!musb->gadget_driver)
1966 		return -EINVAL;
1967 
1968 	if (musb->xceiv->last_event == USB_EVENT_NONE)
1969 		pm_runtime_get_sync(musb->controller);
1970 
1971 	/*
1972 	 * REVISIT always use otg_set_peripheral() here too;
1973 	 * this needs to shut down the OTG engine.
1974 	 */
1975 
1976 	spin_lock_irqsave(&musb->lock, flags);
1977 
1978 #ifdef	CONFIG_USB_MUSB_OTG
1979 	musb_hnp_stop(musb);
1980 #endif
1981 
1982 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1983 
1984 	musb->xceiv->state = OTG_STATE_UNDEFINED;
1985 	stop_activity(musb, driver);
1986 	otg_set_peripheral(musb->xceiv, NULL);
1987 
1988 	DBG(3, "unregistering driver %s\n", driver->function);
1989 
1990 	spin_unlock_irqrestore(&musb->lock, flags);
1991 	driver->unbind(&musb->g);
1992 	spin_lock_irqsave(&musb->lock, flags);
1993 
1994 	musb->gadget_driver = NULL;
1995 	musb->g.dev.driver = NULL;
1996 
1997 	musb->is_active = 0;
1998 	musb_platform_try_idle(musb, 0);
1999 	spin_unlock_irqrestore(&musb->lock, flags);
2000 
2001 	if (is_otg_enabled(musb)) {
2002 		usb_remove_hcd(musb_to_hcd(musb));
2003 		/* FIXME we need to be able to register another
2004 		 * gadget driver here and have everything work;
2005 		 * that currently misbehaves.
2006 		 */
2007 	}
2008 
2009 	if (!is_otg_enabled(musb))
2010 		musb_stop(musb);
2011 
2012 	pm_runtime_put(musb->controller);
2013 
2014 	return 0;
2015 }
2016 EXPORT_SYMBOL(usb_gadget_unregister_driver);
2017 
2018 
2019 /* ----------------------------------------------------------------------- */
2020 
2021 /* lifecycle operations called through plat_uds.c */
2022 
musb_g_resume(struct musb * musb)2023 void musb_g_resume(struct musb *musb)
2024 {
2025 	musb->is_suspended = 0;
2026 	switch (musb->xceiv->state) {
2027 	case OTG_STATE_B_IDLE:
2028 		break;
2029 	case OTG_STATE_B_WAIT_ACON:
2030 	case OTG_STATE_B_PERIPHERAL:
2031 		musb->is_active = 1;
2032 		if (musb->gadget_driver && musb->gadget_driver->resume) {
2033 			spin_unlock(&musb->lock);
2034 			musb->gadget_driver->resume(&musb->g);
2035 			spin_lock(&musb->lock);
2036 		}
2037 		break;
2038 	default:
2039 		WARNING("unhandled RESUME transition (%s)\n",
2040 				otg_state_string(musb));
2041 	}
2042 }
2043 
2044 /* called when SOF packets stop for 3+ msec */
musb_g_suspend(struct musb * musb)2045 void musb_g_suspend(struct musb *musb)
2046 {
2047 	u8	devctl;
2048 
2049 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
2050 	DBG(3, "devctl %02x\n", devctl);
2051 
2052 	switch (musb->xceiv->state) {
2053 	case OTG_STATE_B_IDLE:
2054 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
2055 			musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2056 		break;
2057 	case OTG_STATE_B_PERIPHERAL:
2058 		musb->is_suspended = 1;
2059 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
2060 			spin_unlock(&musb->lock);
2061 			musb->gadget_driver->suspend(&musb->g);
2062 			spin_lock(&musb->lock);
2063 		}
2064 		break;
2065 	default:
2066 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
2067 		 * A_PERIPHERAL may need care too
2068 		 */
2069 		WARNING("unhandled SUSPEND transition (%s)\n",
2070 				otg_state_string(musb));
2071 	}
2072 }
2073 
2074 /* Called during SRP */
musb_g_wakeup(struct musb * musb)2075 void musb_g_wakeup(struct musb *musb)
2076 {
2077 	musb_gadget_wakeup(&musb->g);
2078 }
2079 
2080 /* called when VBUS drops below session threshold, and in other cases */
musb_g_disconnect(struct musb * musb)2081 void musb_g_disconnect(struct musb *musb)
2082 {
2083 	void __iomem	*mregs = musb->mregs;
2084 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
2085 
2086 	DBG(3, "devctl %02x\n", devctl);
2087 
2088 	/* clear HR */
2089 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
2090 
2091 	/* don't draw vbus until new b-default session */
2092 	(void) musb_gadget_vbus_draw(&musb->g, 0);
2093 
2094 	musb->g.speed = USB_SPEED_UNKNOWN;
2095 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
2096 		spin_unlock(&musb->lock);
2097 		musb->gadget_driver->disconnect(&musb->g);
2098 		spin_lock(&musb->lock);
2099 	}
2100 
2101 	switch (musb->xceiv->state) {
2102 	default:
2103 #ifdef	CONFIG_USB_MUSB_OTG
2104 		DBG(2, "Unhandled disconnect %s, setting a_idle\n",
2105 			otg_state_string(musb));
2106 		musb->xceiv->state = OTG_STATE_A_IDLE;
2107 		MUSB_HST_MODE(musb);
2108 		break;
2109 	case OTG_STATE_A_PERIPHERAL:
2110 		musb->xceiv->state = OTG_STATE_A_WAIT_BCON;
2111 		MUSB_HST_MODE(musb);
2112 		break;
2113 	case OTG_STATE_B_WAIT_ACON:
2114 	case OTG_STATE_B_HOST:
2115 #endif
2116 	case OTG_STATE_B_PERIPHERAL:
2117 	case OTG_STATE_B_IDLE:
2118 		musb->xceiv->state = OTG_STATE_B_IDLE;
2119 		break;
2120 	case OTG_STATE_B_SRP_INIT:
2121 		break;
2122 	}
2123 
2124 	musb->is_active = 0;
2125 }
2126 
musb_g_reset(struct musb * musb)2127 void musb_g_reset(struct musb *musb)
2128 __releases(musb->lock)
2129 __acquires(musb->lock)
2130 {
2131 	void __iomem	*mbase = musb->mregs;
2132 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2133 	u8		power;
2134 
2135 	DBG(3, "<== %s addr=%x driver '%s'\n",
2136 			(devctl & MUSB_DEVCTL_BDEVICE)
2137 				? "B-Device" : "A-Device",
2138 			musb_readb(mbase, MUSB_FADDR),
2139 			musb->gadget_driver
2140 				? musb->gadget_driver->driver.name
2141 				: NULL
2142 			);
2143 
2144 	/* report disconnect, if we didn't already (flushing EP state) */
2145 	if (musb->g.speed != USB_SPEED_UNKNOWN)
2146 		musb_g_disconnect(musb);
2147 
2148 	/* clear HR */
2149 	else if (devctl & MUSB_DEVCTL_HR)
2150 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2151 
2152 
2153 	/* what speed did we negotiate? */
2154 	power = musb_readb(mbase, MUSB_POWER);
2155 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2156 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2157 
2158 	/* start in USB_STATE_DEFAULT */
2159 	musb->is_active = 1;
2160 	musb->is_suspended = 0;
2161 	MUSB_DEV_MODE(musb);
2162 	musb->address = 0;
2163 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2164 
2165 	musb->may_wakeup = 0;
2166 	musb->g.b_hnp_enable = 0;
2167 	musb->g.a_alt_hnp_support = 0;
2168 	musb->g.a_hnp_support = 0;
2169 
2170 	/* Normal reset, as B-Device;
2171 	 * or else after HNP, as A-Device
2172 	 */
2173 	if (devctl & MUSB_DEVCTL_BDEVICE) {
2174 		musb->xceiv->state = OTG_STATE_B_PERIPHERAL;
2175 		musb->g.is_a_peripheral = 0;
2176 	} else if (is_otg_enabled(musb)) {
2177 		musb->xceiv->state = OTG_STATE_A_PERIPHERAL;
2178 		musb->g.is_a_peripheral = 1;
2179 	} else
2180 		WARN_ON(1);
2181 
2182 	/* start with default limits on VBUS power draw */
2183 	(void) musb_gadget_vbus_draw(&musb->g,
2184 			is_otg_enabled(musb) ? 8 : 100);
2185 }
2186