1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * MUSB OTG driver peripheral support
4  *
5  * Copyright 2005 Mentor Graphics Corporation
6  * Copyright (C) 2005-2006 by Texas Instruments
7  * Copyright (C) 2006-2007 Nokia Corporation
8  * Copyright (C) 2009 MontaVista Software, Inc. <[email protected]>
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/timer.h>
14 #include <linux/module.h>
15 #include <linux/smp.h>
16 #include <linux/spinlock.h>
17 #include <linux/string_choices.h>
18 #include <linux/delay.h>
19 #include <linux/dma-mapping.h>
20 #include <linux/slab.h>
21 
22 #include "musb_core.h"
23 #include "musb_trace.h"
24 
25 
26 /* ----------------------------------------------------------------------- */
27 
28 #define is_buffer_mapped(req) (is_dma_capable() && \
29 					(req->map_state != UN_MAPPED))
30 
31 /* Maps the buffer to dma  */
32 
map_dma_buffer(struct musb_request * request,struct musb * musb,struct musb_ep * musb_ep)33 static inline void map_dma_buffer(struct musb_request *request,
34 			struct musb *musb, struct musb_ep *musb_ep)
35 {
36 	int compatible = true;
37 	struct dma_controller *dma = musb->dma_controller;
38 
39 	request->map_state = UN_MAPPED;
40 
41 	if (!is_dma_capable() || !musb_ep->dma)
42 		return;
43 
44 	/* Check if DMA engine can handle this request.
45 	 * DMA code must reject the USB request explicitly.
46 	 * Default behaviour is to map the request.
47 	 */
48 	if (dma->is_compatible)
49 		compatible = dma->is_compatible(musb_ep->dma,
50 				musb_ep->packet_sz, request->request.buf,
51 				request->request.length);
52 	if (!compatible)
53 		return;
54 
55 	if (request->request.dma == DMA_ADDR_INVALID) {
56 		dma_addr_t dma_addr;
57 		int ret;
58 
59 		dma_addr = dma_map_single(
60 				musb->controller,
61 				request->request.buf,
62 				request->request.length,
63 				request->tx
64 					? DMA_TO_DEVICE
65 					: DMA_FROM_DEVICE);
66 		ret = dma_mapping_error(musb->controller, dma_addr);
67 		if (ret)
68 			return;
69 
70 		request->request.dma = dma_addr;
71 		request->map_state = MUSB_MAPPED;
72 	} else {
73 		dma_sync_single_for_device(musb->controller,
74 			request->request.dma,
75 			request->request.length,
76 			request->tx
77 				? DMA_TO_DEVICE
78 				: DMA_FROM_DEVICE);
79 		request->map_state = PRE_MAPPED;
80 	}
81 }
82 
83 /* Unmap the buffer from dma and maps it back to cpu */
unmap_dma_buffer(struct musb_request * request,struct musb * musb)84 static inline void unmap_dma_buffer(struct musb_request *request,
85 				struct musb *musb)
86 {
87 	struct musb_ep *musb_ep = request->ep;
88 
89 	if (!is_buffer_mapped(request) || !musb_ep->dma)
90 		return;
91 
92 	if (request->request.dma == DMA_ADDR_INVALID) {
93 		dev_vdbg(musb->controller,
94 				"not unmapping a never mapped buffer\n");
95 		return;
96 	}
97 	if (request->map_state == MUSB_MAPPED) {
98 		dma_unmap_single(musb->controller,
99 			request->request.dma,
100 			request->request.length,
101 			request->tx
102 				? DMA_TO_DEVICE
103 				: DMA_FROM_DEVICE);
104 		request->request.dma = DMA_ADDR_INVALID;
105 	} else { /* PRE_MAPPED */
106 		dma_sync_single_for_cpu(musb->controller,
107 			request->request.dma,
108 			request->request.length,
109 			request->tx
110 				? DMA_TO_DEVICE
111 				: DMA_FROM_DEVICE);
112 	}
113 	request->map_state = UN_MAPPED;
114 }
115 
116 /*
117  * Immediately complete a request.
118  *
119  * @param request the request to complete
120  * @param status the status to complete the request with
121  * Context: controller locked, IRQs blocked.
122  */
musb_g_giveback(struct musb_ep * ep,struct usb_request * request,int status)123 void musb_g_giveback(
124 	struct musb_ep		*ep,
125 	struct usb_request	*request,
126 	int			status)
127 __releases(ep->musb->lock)
128 __acquires(ep->musb->lock)
129 {
130 	struct musb_request	*req;
131 	struct musb		*musb;
132 	int			busy = ep->busy;
133 
134 	req = to_musb_request(request);
135 
136 	list_del(&req->list);
137 	if (req->request.status == -EINPROGRESS)
138 		req->request.status = status;
139 	musb = req->musb;
140 
141 	ep->busy = 1;
142 	spin_unlock(&musb->lock);
143 
144 	if (!dma_mapping_error(&musb->g.dev, request->dma))
145 		unmap_dma_buffer(req, musb);
146 
147 	trace_musb_req_gb(req);
148 	usb_gadget_giveback_request(&req->ep->end_point, &req->request);
149 	spin_lock(&musb->lock);
150 	ep->busy = busy;
151 }
152 
153 /* ----------------------------------------------------------------------- */
154 
155 /*
156  * Abort requests queued to an endpoint using the status. Synchronous.
157  * caller locked controller and blocked irqs, and selected this ep.
158  */
nuke(struct musb_ep * ep,const int status)159 static void nuke(struct musb_ep *ep, const int status)
160 {
161 	struct musb		*musb = ep->musb;
162 	struct musb_request	*req = NULL;
163 	void __iomem *epio = ep->musb->endpoints[ep->current_epnum].regs;
164 
165 	ep->busy = 1;
166 
167 	if (is_dma_capable() && ep->dma) {
168 		struct dma_controller	*c = ep->musb->dma_controller;
169 		int value;
170 
171 		if (ep->is_in) {
172 			/*
173 			 * The programming guide says that we must not clear
174 			 * the DMAMODE bit before DMAENAB, so we only
175 			 * clear it in the second write...
176 			 */
177 			musb_writew(epio, MUSB_TXCSR,
178 				    MUSB_TXCSR_DMAMODE | MUSB_TXCSR_FLUSHFIFO);
179 			musb_writew(epio, MUSB_TXCSR,
180 					0 | MUSB_TXCSR_FLUSHFIFO);
181 		} else {
182 			musb_writew(epio, MUSB_RXCSR,
183 					0 | MUSB_RXCSR_FLUSHFIFO);
184 			musb_writew(epio, MUSB_RXCSR,
185 					0 | MUSB_RXCSR_FLUSHFIFO);
186 		}
187 
188 		value = c->channel_abort(ep->dma);
189 		musb_dbg(musb, "%s: abort DMA --> %d", ep->name, value);
190 		c->channel_release(ep->dma);
191 		ep->dma = NULL;
192 	}
193 
194 	while (!list_empty(&ep->req_list)) {
195 		req = list_first_entry(&ep->req_list, struct musb_request, list);
196 		musb_g_giveback(ep, &req->request, status);
197 	}
198 }
199 
200 /* ----------------------------------------------------------------------- */
201 
202 /* Data transfers - pure PIO, pure DMA, or mixed mode */
203 
204 /*
205  * This assumes the separate CPPI engine is responding to DMA requests
206  * from the usb core ... sequenced a bit differently from mentor dma.
207  */
208 
max_ep_writesize(struct musb * musb,struct musb_ep * ep)209 static inline int max_ep_writesize(struct musb *musb, struct musb_ep *ep)
210 {
211 	if (can_bulk_split(musb, ep->type))
212 		return ep->hw_ep->max_packet_sz_tx;
213 	else
214 		return ep->packet_sz;
215 }
216 
217 /*
218  * An endpoint is transmitting data. This can be called either from
219  * the IRQ routine or from ep.queue() to kickstart a request on an
220  * endpoint.
221  *
222  * Context: controller locked, IRQs blocked, endpoint selected
223  */
txstate(struct musb * musb,struct musb_request * req)224 static void txstate(struct musb *musb, struct musb_request *req)
225 {
226 	u8			epnum = req->epnum;
227 	struct musb_ep		*musb_ep;
228 	void __iomem		*epio = musb->endpoints[epnum].regs;
229 	struct usb_request	*request;
230 	u16			fifo_count = 0, csr;
231 	int			use_dma = 0;
232 
233 	musb_ep = req->ep;
234 
235 	/* Check if EP is disabled */
236 	if (!musb_ep->desc) {
237 		musb_dbg(musb, "ep:%s disabled - ignore request",
238 						musb_ep->end_point.name);
239 		return;
240 	}
241 
242 	/* we shouldn't get here while DMA is active ... but we do ... */
243 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
244 		musb_dbg(musb, "dma pending...");
245 		return;
246 	}
247 
248 	/* read TXCSR before */
249 	csr = musb_readw(epio, MUSB_TXCSR);
250 
251 	request = &req->request;
252 	fifo_count = min(max_ep_writesize(musb, musb_ep),
253 			(int)(request->length - request->actual));
254 
255 	if (csr & MUSB_TXCSR_TXPKTRDY) {
256 		musb_dbg(musb, "%s old packet still ready , txcsr %03x",
257 				musb_ep->end_point.name, csr);
258 		return;
259 	}
260 
261 	if (csr & MUSB_TXCSR_P_SENDSTALL) {
262 		musb_dbg(musb, "%s stalling, txcsr %03x",
263 				musb_ep->end_point.name, csr);
264 		return;
265 	}
266 
267 	musb_dbg(musb, "hw_ep%d, maxpacket %d, fifo count %d, txcsr %03x",
268 			epnum, musb_ep->packet_sz, fifo_count,
269 			csr);
270 
271 #ifndef	CONFIG_MUSB_PIO_ONLY
272 	if (is_buffer_mapped(req)) {
273 		struct dma_controller	*c = musb->dma_controller;
274 		size_t request_size;
275 
276 		/* setup DMA, then program endpoint CSR */
277 		request_size = min_t(size_t, request->length - request->actual,
278 					musb_ep->dma->max_len);
279 
280 		use_dma = (request->dma != DMA_ADDR_INVALID && request_size);
281 
282 		/* MUSB_TXCSR_P_ISO is still set correctly */
283 
284 		if (musb_dma_inventra(musb) || musb_dma_ux500(musb)) {
285 			if (request_size < musb_ep->packet_sz)
286 				musb_ep->dma->desired_mode = 0;
287 			else
288 				musb_ep->dma->desired_mode = 1;
289 
290 			use_dma = use_dma && c->channel_program(
291 					musb_ep->dma, musb_ep->packet_sz,
292 					musb_ep->dma->desired_mode,
293 					request->dma + request->actual, request_size);
294 			if (use_dma) {
295 				if (musb_ep->dma->desired_mode == 0) {
296 					/*
297 					 * We must not clear the DMAMODE bit
298 					 * before the DMAENAB bit -- and the
299 					 * latter doesn't always get cleared
300 					 * before we get here...
301 					 */
302 					csr &= ~(MUSB_TXCSR_AUTOSET
303 						| MUSB_TXCSR_DMAENAB);
304 					musb_writew(epio, MUSB_TXCSR, csr
305 						| MUSB_TXCSR_P_WZC_BITS);
306 					csr &= ~MUSB_TXCSR_DMAMODE;
307 					csr |= (MUSB_TXCSR_DMAENAB |
308 							MUSB_TXCSR_MODE);
309 					/* against programming guide */
310 				} else {
311 					csr |= (MUSB_TXCSR_DMAENAB
312 							| MUSB_TXCSR_DMAMODE
313 							| MUSB_TXCSR_MODE);
314 					/*
315 					 * Enable Autoset according to table
316 					 * below
317 					 * bulk_split hb_mult	Autoset_Enable
318 					 *	0	0	Yes(Normal)
319 					 *	0	>0	No(High BW ISO)
320 					 *	1	0	Yes(HS bulk)
321 					 *	1	>0	Yes(FS bulk)
322 					 */
323 					if (!musb_ep->hb_mult ||
324 					    can_bulk_split(musb,
325 							   musb_ep->type))
326 						csr |= MUSB_TXCSR_AUTOSET;
327 				}
328 				csr &= ~MUSB_TXCSR_P_UNDERRUN;
329 
330 				musb_writew(epio, MUSB_TXCSR, csr);
331 			}
332 		}
333 
334 		if (is_cppi_enabled(musb)) {
335 			/* program endpoint CSR first, then setup DMA */
336 			csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
337 			csr |= MUSB_TXCSR_DMAENAB | MUSB_TXCSR_DMAMODE |
338 				MUSB_TXCSR_MODE;
339 			musb_writew(epio, MUSB_TXCSR, (MUSB_TXCSR_P_WZC_BITS &
340 						~MUSB_TXCSR_P_UNDERRUN) | csr);
341 
342 			/* ensure writebuffer is empty */
343 			csr = musb_readw(epio, MUSB_TXCSR);
344 
345 			/*
346 			 * NOTE host side sets DMAENAB later than this; both are
347 			 * OK since the transfer dma glue (between CPPI and
348 			 * Mentor fifos) just tells CPPI it could start. Data
349 			 * only moves to the USB TX fifo when both fifos are
350 			 * ready.
351 			 */
352 			/*
353 			 * "mode" is irrelevant here; handle terminating ZLPs
354 			 * like PIO does, since the hardware RNDIS mode seems
355 			 * unreliable except for the
356 			 * last-packet-is-already-short case.
357 			 */
358 			use_dma = use_dma && c->channel_program(
359 					musb_ep->dma, musb_ep->packet_sz,
360 					0,
361 					request->dma + request->actual,
362 					request_size);
363 			if (!use_dma) {
364 				c->channel_release(musb_ep->dma);
365 				musb_ep->dma = NULL;
366 				csr &= ~MUSB_TXCSR_DMAENAB;
367 				musb_writew(epio, MUSB_TXCSR, csr);
368 				/* invariant: prequest->buf is non-null */
369 			}
370 		} else if (tusb_dma_omap(musb))
371 			use_dma = use_dma && c->channel_program(
372 					musb_ep->dma, musb_ep->packet_sz,
373 					request->zero,
374 					request->dma + request->actual,
375 					request_size);
376 	}
377 #endif
378 
379 	if (!use_dma) {
380 		/*
381 		 * Unmap the dma buffer back to cpu if dma channel
382 		 * programming fails
383 		 */
384 		unmap_dma_buffer(req, musb);
385 
386 		musb_write_fifo(musb_ep->hw_ep, fifo_count,
387 				(u8 *) (request->buf + request->actual));
388 		request->actual += fifo_count;
389 		csr |= MUSB_TXCSR_TXPKTRDY;
390 		csr &= ~MUSB_TXCSR_P_UNDERRUN;
391 		musb_writew(epio, MUSB_TXCSR, csr);
392 	}
393 
394 	/* host may already have the data when this message shows... */
395 	musb_dbg(musb, "%s TX/IN %s len %d/%d, txcsr %04x, fifo %d/%d",
396 			musb_ep->end_point.name, use_dma ? "dma" : "pio",
397 			request->actual, request->length,
398 			musb_readw(epio, MUSB_TXCSR),
399 			fifo_count,
400 			musb_readw(epio, MUSB_TXMAXP));
401 }
402 
403 /*
404  * FIFO state update (e.g. data ready).
405  * Called from IRQ,  with controller locked.
406  */
musb_g_tx(struct musb * musb,u8 epnum)407 void musb_g_tx(struct musb *musb, u8 epnum)
408 {
409 	u16			csr;
410 	struct musb_request	*req;
411 	struct usb_request	*request;
412 	u8 __iomem		*mbase = musb->mregs;
413 	struct musb_ep		*musb_ep = &musb->endpoints[epnum].ep_in;
414 	void __iomem		*epio = musb->endpoints[epnum].regs;
415 	struct dma_channel	*dma;
416 
417 	musb_ep_select(mbase, epnum);
418 	req = next_request(musb_ep);
419 	request = &req->request;
420 
421 	csr = musb_readw(epio, MUSB_TXCSR);
422 	musb_dbg(musb, "<== %s, txcsr %04x", musb_ep->end_point.name, csr);
423 
424 	dma = is_dma_capable() ? musb_ep->dma : NULL;
425 
426 	/*
427 	 * REVISIT: for high bandwidth, MUSB_TXCSR_P_INCOMPTX
428 	 * probably rates reporting as a host error.
429 	 */
430 	if (csr & MUSB_TXCSR_P_SENTSTALL) {
431 		csr |=	MUSB_TXCSR_P_WZC_BITS;
432 		csr &= ~MUSB_TXCSR_P_SENTSTALL;
433 		musb_writew(epio, MUSB_TXCSR, csr);
434 		return;
435 	}
436 
437 	if (csr & MUSB_TXCSR_P_UNDERRUN) {
438 		/* We NAKed, no big deal... little reason to care. */
439 		csr |=	 MUSB_TXCSR_P_WZC_BITS;
440 		csr &= ~(MUSB_TXCSR_P_UNDERRUN | MUSB_TXCSR_TXPKTRDY);
441 		musb_writew(epio, MUSB_TXCSR, csr);
442 		dev_vdbg(musb->controller, "underrun on ep%d, req %p\n",
443 				epnum, request);
444 	}
445 
446 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
447 		/*
448 		 * SHOULD NOT HAPPEN... has with CPPI though, after
449 		 * changing SENDSTALL (and other cases); harmless?
450 		 */
451 		musb_dbg(musb, "%s dma still busy?", musb_ep->end_point.name);
452 		return;
453 	}
454 
455 	if (req) {
456 
457 		trace_musb_req_tx(req);
458 
459 		if (dma && (csr & MUSB_TXCSR_DMAENAB)) {
460 			csr |= MUSB_TXCSR_P_WZC_BITS;
461 			csr &= ~(MUSB_TXCSR_DMAENAB | MUSB_TXCSR_P_UNDERRUN |
462 				 MUSB_TXCSR_TXPKTRDY | MUSB_TXCSR_AUTOSET);
463 			musb_writew(epio, MUSB_TXCSR, csr);
464 			/* Ensure writebuffer is empty. */
465 			csr = musb_readw(epio, MUSB_TXCSR);
466 			request->actual += musb_ep->dma->actual_len;
467 			musb_dbg(musb, "TXCSR%d %04x, DMA off, len %zu, req %p",
468 				epnum, csr, musb_ep->dma->actual_len, request);
469 		}
470 
471 		/*
472 		 * First, maybe a terminating short packet. Some DMA
473 		 * engines might handle this by themselves.
474 		 */
475 		if ((request->zero && request->length)
476 			&& (request->length % musb_ep->packet_sz == 0)
477 			&& (request->actual == request->length)) {
478 
479 			/*
480 			 * On DMA completion, FIFO may not be
481 			 * available yet...
482 			 */
483 			if (csr & MUSB_TXCSR_TXPKTRDY)
484 				return;
485 
486 			musb_writew(epio, MUSB_TXCSR, MUSB_TXCSR_MODE
487 					| MUSB_TXCSR_TXPKTRDY);
488 			request->zero = 0;
489 		}
490 
491 		if (request->actual == request->length) {
492 			musb_g_giveback(musb_ep, request, 0);
493 			/*
494 			 * In the giveback function the MUSB lock is
495 			 * released and acquired after sometime. During
496 			 * this time period the INDEX register could get
497 			 * changed by the gadget_queue function especially
498 			 * on SMP systems. Reselect the INDEX to be sure
499 			 * we are reading/modifying the right registers
500 			 */
501 			musb_ep_select(mbase, epnum);
502 			req = musb_ep->desc ? next_request(musb_ep) : NULL;
503 			if (!req) {
504 				musb_dbg(musb, "%s idle now",
505 					musb_ep->end_point.name);
506 				return;
507 			}
508 		}
509 
510 		txstate(musb, req);
511 	}
512 }
513 
514 /* ------------------------------------------------------------ */
515 
516 /*
517  * Context: controller locked, IRQs blocked, endpoint selected
518  */
rxstate(struct musb * musb,struct musb_request * req)519 static void rxstate(struct musb *musb, struct musb_request *req)
520 {
521 	const u8		epnum = req->epnum;
522 	struct usb_request	*request = &req->request;
523 	struct musb_ep		*musb_ep;
524 	void __iomem		*epio = musb->endpoints[epnum].regs;
525 	unsigned		len = 0;
526 	u16			fifo_count;
527 	u16			csr = musb_readw(epio, MUSB_RXCSR);
528 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
529 	u8			use_mode_1;
530 
531 	if (hw_ep->is_shared_fifo)
532 		musb_ep = &hw_ep->ep_in;
533 	else
534 		musb_ep = &hw_ep->ep_out;
535 
536 	fifo_count = musb_ep->packet_sz;
537 
538 	/* Check if EP is disabled */
539 	if (!musb_ep->desc) {
540 		musb_dbg(musb, "ep:%s disabled - ignore request",
541 						musb_ep->end_point.name);
542 		return;
543 	}
544 
545 	/* We shouldn't get here while DMA is active, but we do... */
546 	if (dma_channel_status(musb_ep->dma) == MUSB_DMA_STATUS_BUSY) {
547 		musb_dbg(musb, "DMA pending...");
548 		return;
549 	}
550 
551 	if (csr & MUSB_RXCSR_P_SENDSTALL) {
552 		musb_dbg(musb, "%s stalling, RXCSR %04x",
553 		    musb_ep->end_point.name, csr);
554 		return;
555 	}
556 
557 	if (is_cppi_enabled(musb) && is_buffer_mapped(req)) {
558 		struct dma_controller	*c = musb->dma_controller;
559 		struct dma_channel	*channel = musb_ep->dma;
560 
561 		/* NOTE:  CPPI won't actually stop advancing the DMA
562 		 * queue after short packet transfers, so this is almost
563 		 * always going to run as IRQ-per-packet DMA so that
564 		 * faults will be handled correctly.
565 		 */
566 		if (c->channel_program(channel,
567 				musb_ep->packet_sz,
568 				!request->short_not_ok,
569 				request->dma + request->actual,
570 				request->length - request->actual)) {
571 
572 			/* make sure that if an rxpkt arrived after the irq,
573 			 * the cppi engine will be ready to take it as soon
574 			 * as DMA is enabled
575 			 */
576 			csr &= ~(MUSB_RXCSR_AUTOCLEAR
577 					| MUSB_RXCSR_DMAMODE);
578 			csr |= MUSB_RXCSR_DMAENAB | MUSB_RXCSR_P_WZC_BITS;
579 			musb_writew(epio, MUSB_RXCSR, csr);
580 			return;
581 		}
582 	}
583 
584 	if (csr & MUSB_RXCSR_RXPKTRDY) {
585 		fifo_count = musb_readw(epio, MUSB_RXCOUNT);
586 
587 		/*
588 		 * Enable Mode 1 on RX transfers only when short_not_ok flag
589 		 * is set. Currently short_not_ok flag is set only from
590 		 * file_storage and f_mass_storage drivers
591 		 */
592 
593 		if (request->short_not_ok && fifo_count == musb_ep->packet_sz)
594 			use_mode_1 = 1;
595 		else
596 			use_mode_1 = 0;
597 
598 		if (request->actual < request->length) {
599 			if (!is_buffer_mapped(req))
600 				goto buffer_aint_mapped;
601 
602 			if (musb_dma_inventra(musb)) {
603 				struct dma_controller	*c;
604 				struct dma_channel	*channel;
605 				int			use_dma = 0;
606 				unsigned int transfer_size;
607 
608 				c = musb->dma_controller;
609 				channel = musb_ep->dma;
610 
611 	/* We use DMA Req mode 0 in rx_csr, and DMA controller operates in
612 	 * mode 0 only. So we do not get endpoint interrupts due to DMA
613 	 * completion. We only get interrupts from DMA controller.
614 	 *
615 	 * We could operate in DMA mode 1 if we knew the size of the transfer
616 	 * in advance. For mass storage class, request->length = what the host
617 	 * sends, so that'd work.  But for pretty much everything else,
618 	 * request->length is routinely more than what the host sends. For
619 	 * most these gadgets, end of is signified either by a short packet,
620 	 * or filling the last byte of the buffer.  (Sending extra data in
621 	 * that last pckate should trigger an overflow fault.)  But in mode 1,
622 	 * we don't get DMA completion interrupt for short packets.
623 	 *
624 	 * Theoretically, we could enable DMAReq irq (MUSB_RXCSR_DMAMODE = 1),
625 	 * to get endpoint interrupt on every DMA req, but that didn't seem
626 	 * to work reliably.
627 	 *
628 	 * REVISIT an updated g_file_storage can set req->short_not_ok, which
629 	 * then becomes usable as a runtime "use mode 1" hint...
630 	 */
631 
632 				/* Experimental: Mode1 works with mass storage use cases */
633 				if (use_mode_1) {
634 					csr |= MUSB_RXCSR_AUTOCLEAR;
635 					musb_writew(epio, MUSB_RXCSR, csr);
636 					csr |= MUSB_RXCSR_DMAENAB;
637 					musb_writew(epio, MUSB_RXCSR, csr);
638 
639 					/*
640 					 * this special sequence (enabling and then
641 					 * disabling MUSB_RXCSR_DMAMODE) is required
642 					 * to get DMAReq to activate
643 					 */
644 					musb_writew(epio, MUSB_RXCSR,
645 						csr | MUSB_RXCSR_DMAMODE);
646 					musb_writew(epio, MUSB_RXCSR, csr);
647 
648 					transfer_size = min_t(unsigned int,
649 							request->length -
650 							request->actual,
651 							channel->max_len);
652 					musb_ep->dma->desired_mode = 1;
653 				} else {
654 					if (!musb_ep->hb_mult &&
655 						musb_ep->hw_ep->rx_double_buffered)
656 						csr |= MUSB_RXCSR_AUTOCLEAR;
657 					csr |= MUSB_RXCSR_DMAENAB;
658 					musb_writew(epio, MUSB_RXCSR, csr);
659 
660 					transfer_size = min(request->length - request->actual,
661 							(unsigned)fifo_count);
662 					musb_ep->dma->desired_mode = 0;
663 				}
664 
665 				use_dma = c->channel_program(
666 						channel,
667 						musb_ep->packet_sz,
668 						channel->desired_mode,
669 						request->dma
670 						+ request->actual,
671 						transfer_size);
672 
673 				if (use_dma)
674 					return;
675 			}
676 
677 			if ((musb_dma_ux500(musb)) &&
678 				(request->actual < request->length)) {
679 
680 				struct dma_controller *c;
681 				struct dma_channel *channel;
682 				unsigned int transfer_size = 0;
683 
684 				c = musb->dma_controller;
685 				channel = musb_ep->dma;
686 
687 				/* In case first packet is short */
688 				if (fifo_count < musb_ep->packet_sz)
689 					transfer_size = fifo_count;
690 				else if (request->short_not_ok)
691 					transfer_size =	min_t(unsigned int,
692 							request->length -
693 							request->actual,
694 							channel->max_len);
695 				else
696 					transfer_size = min_t(unsigned int,
697 							request->length -
698 							request->actual,
699 							(unsigned)fifo_count);
700 
701 				csr &= ~MUSB_RXCSR_DMAMODE;
702 				csr |= (MUSB_RXCSR_DMAENAB |
703 					MUSB_RXCSR_AUTOCLEAR);
704 
705 				musb_writew(epio, MUSB_RXCSR, csr);
706 
707 				if (transfer_size <= musb_ep->packet_sz) {
708 					musb_ep->dma->desired_mode = 0;
709 				} else {
710 					musb_ep->dma->desired_mode = 1;
711 					/* Mode must be set after DMAENAB */
712 					csr |= MUSB_RXCSR_DMAMODE;
713 					musb_writew(epio, MUSB_RXCSR, csr);
714 				}
715 
716 				if (c->channel_program(channel,
717 							musb_ep->packet_sz,
718 							channel->desired_mode,
719 							request->dma
720 							+ request->actual,
721 							transfer_size))
722 
723 					return;
724 			}
725 
726 			len = request->length - request->actual;
727 			musb_dbg(musb, "%s OUT/RX pio fifo %d/%d, maxpacket %d",
728 					musb_ep->end_point.name,
729 					fifo_count, len,
730 					musb_ep->packet_sz);
731 
732 			fifo_count = min_t(unsigned, len, fifo_count);
733 
734 			if (tusb_dma_omap(musb)) {
735 				struct dma_controller *c = musb->dma_controller;
736 				struct dma_channel *channel = musb_ep->dma;
737 				u32 dma_addr = request->dma + request->actual;
738 				int ret;
739 
740 				ret = c->channel_program(channel,
741 						musb_ep->packet_sz,
742 						channel->desired_mode,
743 						dma_addr,
744 						fifo_count);
745 				if (ret)
746 					return;
747 			}
748 
749 			/*
750 			 * Unmap the dma buffer back to cpu if dma channel
751 			 * programming fails. This buffer is mapped if the
752 			 * channel allocation is successful
753 			 */
754 			unmap_dma_buffer(req, musb);
755 
756 			/*
757 			 * Clear DMAENAB and AUTOCLEAR for the
758 			 * PIO mode transfer
759 			 */
760 			csr &= ~(MUSB_RXCSR_DMAENAB | MUSB_RXCSR_AUTOCLEAR);
761 			musb_writew(epio, MUSB_RXCSR, csr);
762 
763 buffer_aint_mapped:
764 			fifo_count = min_t(unsigned int,
765 					request->length - request->actual,
766 					(unsigned int)fifo_count);
767 			musb_read_fifo(musb_ep->hw_ep, fifo_count, (u8 *)
768 					(request->buf + request->actual));
769 			request->actual += fifo_count;
770 
771 			/* REVISIT if we left anything in the fifo, flush
772 			 * it and report -EOVERFLOW
773 			 */
774 
775 			/* ack the read! */
776 			csr |= MUSB_RXCSR_P_WZC_BITS;
777 			csr &= ~MUSB_RXCSR_RXPKTRDY;
778 			musb_writew(epio, MUSB_RXCSR, csr);
779 		}
780 	}
781 
782 	/* reach the end or short packet detected */
783 	if (request->actual == request->length ||
784 	    fifo_count < musb_ep->packet_sz)
785 		musb_g_giveback(musb_ep, request, 0);
786 }
787 
788 /*
789  * Data ready for a request; called from IRQ
790  */
musb_g_rx(struct musb * musb,u8 epnum)791 void musb_g_rx(struct musb *musb, u8 epnum)
792 {
793 	u16			csr;
794 	struct musb_request	*req;
795 	struct usb_request	*request;
796 	void __iomem		*mbase = musb->mregs;
797 	struct musb_ep		*musb_ep;
798 	void __iomem		*epio = musb->endpoints[epnum].regs;
799 	struct dma_channel	*dma;
800 	struct musb_hw_ep	*hw_ep = &musb->endpoints[epnum];
801 
802 	if (hw_ep->is_shared_fifo)
803 		musb_ep = &hw_ep->ep_in;
804 	else
805 		musb_ep = &hw_ep->ep_out;
806 
807 	musb_ep_select(mbase, epnum);
808 
809 	req = next_request(musb_ep);
810 	if (!req)
811 		return;
812 
813 	trace_musb_req_rx(req);
814 	request = &req->request;
815 
816 	csr = musb_readw(epio, MUSB_RXCSR);
817 	dma = is_dma_capable() ? musb_ep->dma : NULL;
818 
819 	musb_dbg(musb, "<== %s, rxcsr %04x%s %p", musb_ep->end_point.name,
820 			csr, dma ? " (dma)" : "", request);
821 
822 	if (csr & MUSB_RXCSR_P_SENTSTALL) {
823 		csr |= MUSB_RXCSR_P_WZC_BITS;
824 		csr &= ~MUSB_RXCSR_P_SENTSTALL;
825 		musb_writew(epio, MUSB_RXCSR, csr);
826 		return;
827 	}
828 
829 	if (csr & MUSB_RXCSR_P_OVERRUN) {
830 		/* csr |= MUSB_RXCSR_P_WZC_BITS; */
831 		csr &= ~MUSB_RXCSR_P_OVERRUN;
832 		musb_writew(epio, MUSB_RXCSR, csr);
833 
834 		musb_dbg(musb, "%s iso overrun on %p", musb_ep->name, request);
835 		if (request->status == -EINPROGRESS)
836 			request->status = -EOVERFLOW;
837 	}
838 	if (csr & MUSB_RXCSR_INCOMPRX) {
839 		/* REVISIT not necessarily an error */
840 		musb_dbg(musb, "%s, incomprx", musb_ep->end_point.name);
841 	}
842 
843 	if (dma_channel_status(dma) == MUSB_DMA_STATUS_BUSY) {
844 		/* "should not happen"; likely RXPKTRDY pending for DMA */
845 		musb_dbg(musb, "%s busy, csr %04x",
846 			musb_ep->end_point.name, csr);
847 		return;
848 	}
849 
850 	if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
851 		csr &= ~(MUSB_RXCSR_AUTOCLEAR
852 				| MUSB_RXCSR_DMAENAB
853 				| MUSB_RXCSR_DMAMODE);
854 		musb_writew(epio, MUSB_RXCSR,
855 			MUSB_RXCSR_P_WZC_BITS | csr);
856 
857 		request->actual += musb_ep->dma->actual_len;
858 
859 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
860 	defined(CONFIG_USB_UX500_DMA)
861 		/* Autoclear doesn't clear RxPktRdy for short packets */
862 		if ((dma->desired_mode == 0 && !hw_ep->rx_double_buffered)
863 				|| (dma->actual_len
864 					& (musb_ep->packet_sz - 1))) {
865 			/* ack the read! */
866 			csr &= ~MUSB_RXCSR_RXPKTRDY;
867 			musb_writew(epio, MUSB_RXCSR, csr);
868 		}
869 
870 		/* incomplete, and not short? wait for next IN packet */
871 		if ((request->actual < request->length)
872 				&& (musb_ep->dma->actual_len
873 					== musb_ep->packet_sz)) {
874 			/* In double buffer case, continue to unload fifo if
875  			 * there is Rx packet in FIFO.
876  			 **/
877 			csr = musb_readw(epio, MUSB_RXCSR);
878 			if ((csr & MUSB_RXCSR_RXPKTRDY) &&
879 				hw_ep->rx_double_buffered)
880 				goto exit;
881 			return;
882 		}
883 #endif
884 		musb_g_giveback(musb_ep, request, 0);
885 		/*
886 		 * In the giveback function the MUSB lock is
887 		 * released and acquired after sometime. During
888 		 * this time period the INDEX register could get
889 		 * changed by the gadget_queue function especially
890 		 * on SMP systems. Reselect the INDEX to be sure
891 		 * we are reading/modifying the right registers
892 		 */
893 		musb_ep_select(mbase, epnum);
894 
895 		req = next_request(musb_ep);
896 		if (!req)
897 			return;
898 	}
899 #if defined(CONFIG_USB_INVENTRA_DMA) || defined(CONFIG_USB_TUSB_OMAP_DMA) || \
900 	defined(CONFIG_USB_UX500_DMA)
901 exit:
902 #endif
903 	/* Analyze request */
904 	rxstate(musb, req);
905 }
906 
907 /* ------------------------------------------------------------ */
908 
musb_gadget_enable(struct usb_ep * ep,const struct usb_endpoint_descriptor * desc)909 static int musb_gadget_enable(struct usb_ep *ep,
910 			const struct usb_endpoint_descriptor *desc)
911 {
912 	unsigned long		flags;
913 	struct musb_ep		*musb_ep;
914 	struct musb_hw_ep	*hw_ep;
915 	void __iomem		*regs;
916 	struct musb		*musb;
917 	void __iomem	*mbase;
918 	u8		epnum;
919 	u16		csr;
920 	unsigned	tmp;
921 	int		status = -EINVAL;
922 
923 	if (!ep || !desc)
924 		return -EINVAL;
925 
926 	musb_ep = to_musb_ep(ep);
927 	hw_ep = musb_ep->hw_ep;
928 	regs = hw_ep->regs;
929 	musb = musb_ep->musb;
930 	mbase = musb->mregs;
931 	epnum = musb_ep->current_epnum;
932 
933 	spin_lock_irqsave(&musb->lock, flags);
934 
935 	if (musb_ep->desc) {
936 		status = -EBUSY;
937 		goto fail;
938 	}
939 	musb_ep->type = usb_endpoint_type(desc);
940 
941 	/* check direction and (later) maxpacket size against endpoint */
942 	if (usb_endpoint_num(desc) != epnum)
943 		goto fail;
944 
945 	/* REVISIT this rules out high bandwidth periodic transfers */
946 	tmp = usb_endpoint_maxp_mult(desc) - 1;
947 	if (tmp) {
948 		int ok;
949 
950 		if (usb_endpoint_dir_in(desc))
951 			ok = musb->hb_iso_tx;
952 		else
953 			ok = musb->hb_iso_rx;
954 
955 		if (!ok) {
956 			musb_dbg(musb, "no support for high bandwidth ISO");
957 			goto fail;
958 		}
959 		musb_ep->hb_mult = tmp;
960 	} else {
961 		musb_ep->hb_mult = 0;
962 	}
963 
964 	musb_ep->packet_sz = usb_endpoint_maxp(desc);
965 	tmp = musb_ep->packet_sz * (musb_ep->hb_mult + 1);
966 
967 	/* enable the interrupts for the endpoint, set the endpoint
968 	 * packet size (or fail), set the mode, clear the fifo
969 	 */
970 	musb_ep_select(mbase, epnum);
971 	if (usb_endpoint_dir_in(desc)) {
972 
973 		if (hw_ep->is_shared_fifo)
974 			musb_ep->is_in = 1;
975 		if (!musb_ep->is_in)
976 			goto fail;
977 
978 		if (tmp > hw_ep->max_packet_sz_tx) {
979 			musb_dbg(musb, "packet size beyond hardware FIFO size");
980 			goto fail;
981 		}
982 
983 		musb->intrtxe |= (1 << epnum);
984 		musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
985 
986 		/* REVISIT if can_bulk_split(), use by updating "tmp";
987 		 * likewise high bandwidth periodic tx
988 		 */
989 		/* Set TXMAXP with the FIFO size of the endpoint
990 		 * to disable double buffering mode.
991 		 */
992 		if (can_bulk_split(musb, musb_ep->type))
993 			musb_ep->hb_mult = (hw_ep->max_packet_sz_tx /
994 						musb_ep->packet_sz) - 1;
995 		musb_writew(regs, MUSB_TXMAXP, musb_ep->packet_sz
996 				| (musb_ep->hb_mult << 11));
997 
998 		csr = MUSB_TXCSR_MODE | MUSB_TXCSR_CLRDATATOG;
999 		if (musb_readw(regs, MUSB_TXCSR)
1000 				& MUSB_TXCSR_FIFONOTEMPTY)
1001 			csr |= MUSB_TXCSR_FLUSHFIFO;
1002 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1003 			csr |= MUSB_TXCSR_P_ISO;
1004 
1005 		/* set twice in case of double buffering */
1006 		musb_writew(regs, MUSB_TXCSR, csr);
1007 		/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1008 		musb_writew(regs, MUSB_TXCSR, csr);
1009 
1010 	} else {
1011 
1012 		if (hw_ep->is_shared_fifo)
1013 			musb_ep->is_in = 0;
1014 		if (musb_ep->is_in)
1015 			goto fail;
1016 
1017 		if (tmp > hw_ep->max_packet_sz_rx) {
1018 			musb_dbg(musb, "packet size beyond hardware FIFO size");
1019 			goto fail;
1020 		}
1021 
1022 		musb->intrrxe |= (1 << epnum);
1023 		musb_writew(mbase, MUSB_INTRRXE, musb->intrrxe);
1024 
1025 		/* REVISIT if can_bulk_combine() use by updating "tmp"
1026 		 * likewise high bandwidth periodic rx
1027 		 */
1028 		/* Set RXMAXP with the FIFO size of the endpoint
1029 		 * to disable double buffering mode.
1030 		 */
1031 		musb_writew(regs, MUSB_RXMAXP, musb_ep->packet_sz
1032 				| (musb_ep->hb_mult << 11));
1033 
1034 		/* force shared fifo to OUT-only mode */
1035 		if (hw_ep->is_shared_fifo) {
1036 			csr = musb_readw(regs, MUSB_TXCSR);
1037 			csr &= ~(MUSB_TXCSR_MODE | MUSB_TXCSR_TXPKTRDY);
1038 			musb_writew(regs, MUSB_TXCSR, csr);
1039 		}
1040 
1041 		csr = MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_CLRDATATOG;
1042 		if (musb_ep->type == USB_ENDPOINT_XFER_ISOC)
1043 			csr |= MUSB_RXCSR_P_ISO;
1044 		else if (musb_ep->type == USB_ENDPOINT_XFER_INT)
1045 			csr |= MUSB_RXCSR_DISNYET;
1046 
1047 		/* set twice in case of double buffering */
1048 		musb_writew(regs, MUSB_RXCSR, csr);
1049 		musb_writew(regs, MUSB_RXCSR, csr);
1050 	}
1051 
1052 	/* NOTE:  all the I/O code _should_ work fine without DMA, in case
1053 	 * for some reason you run out of channels here.
1054 	 */
1055 	if (is_dma_capable() && musb->dma_controller) {
1056 		struct dma_controller	*c = musb->dma_controller;
1057 
1058 		musb_ep->dma = c->channel_alloc(c, hw_ep,
1059 				(desc->bEndpointAddress & USB_DIR_IN));
1060 	} else
1061 		musb_ep->dma = NULL;
1062 
1063 	musb_ep->desc = desc;
1064 	musb_ep->busy = 0;
1065 	musb_ep->wedged = 0;
1066 	status = 0;
1067 
1068 	pr_debug("%s periph: enabled %s for %s %s, %smaxpacket %d\n",
1069 			musb_driver_name, musb_ep->end_point.name,
1070 			musb_ep_xfertype_string(musb_ep->type),
1071 			musb_ep->is_in ? "IN" : "OUT",
1072 			musb_ep->dma ? "dma, " : "",
1073 			musb_ep->packet_sz);
1074 
1075 	schedule_delayed_work(&musb->irq_work, 0);
1076 
1077 fail:
1078 	spin_unlock_irqrestore(&musb->lock, flags);
1079 	return status;
1080 }
1081 
1082 /*
1083  * Disable an endpoint flushing all requests queued.
1084  */
musb_gadget_disable(struct usb_ep * ep)1085 static int musb_gadget_disable(struct usb_ep *ep)
1086 {
1087 	unsigned long	flags;
1088 	struct musb	*musb;
1089 	u8		epnum;
1090 	struct musb_ep	*musb_ep;
1091 	void __iomem	*epio;
1092 
1093 	musb_ep = to_musb_ep(ep);
1094 	musb = musb_ep->musb;
1095 	epnum = musb_ep->current_epnum;
1096 	epio = musb->endpoints[epnum].regs;
1097 
1098 	spin_lock_irqsave(&musb->lock, flags);
1099 	musb_ep_select(musb->mregs, epnum);
1100 
1101 	/* zero the endpoint sizes */
1102 	if (musb_ep->is_in) {
1103 		musb->intrtxe &= ~(1 << epnum);
1104 		musb_writew(musb->mregs, MUSB_INTRTXE, musb->intrtxe);
1105 		musb_writew(epio, MUSB_TXMAXP, 0);
1106 	} else {
1107 		musb->intrrxe &= ~(1 << epnum);
1108 		musb_writew(musb->mregs, MUSB_INTRRXE, musb->intrrxe);
1109 		musb_writew(epio, MUSB_RXMAXP, 0);
1110 	}
1111 
1112 	/* abort all pending DMA and requests */
1113 	nuke(musb_ep, -ESHUTDOWN);
1114 
1115 	musb_ep->desc = NULL;
1116 	musb_ep->end_point.desc = NULL;
1117 
1118 	schedule_delayed_work(&musb->irq_work, 0);
1119 
1120 	spin_unlock_irqrestore(&(musb->lock), flags);
1121 
1122 	musb_dbg(musb, "%s", musb_ep->end_point.name);
1123 
1124 	return 0;
1125 }
1126 
1127 /*
1128  * Allocate a request for an endpoint.
1129  * Reused by ep0 code.
1130  */
musb_alloc_request(struct usb_ep * ep,gfp_t gfp_flags)1131 struct usb_request *musb_alloc_request(struct usb_ep *ep, gfp_t gfp_flags)
1132 {
1133 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1134 	struct musb_request	*request;
1135 
1136 	request = kzalloc(sizeof *request, gfp_flags);
1137 	if (!request)
1138 		return NULL;
1139 
1140 	request->request.dma = DMA_ADDR_INVALID;
1141 	request->epnum = musb_ep->current_epnum;
1142 	request->ep = musb_ep;
1143 
1144 	trace_musb_req_alloc(request);
1145 	return &request->request;
1146 }
1147 
1148 /*
1149  * Free a request
1150  * Reused by ep0 code.
1151  */
musb_free_request(struct usb_ep * ep,struct usb_request * req)1152 void musb_free_request(struct usb_ep *ep, struct usb_request *req)
1153 {
1154 	struct musb_request *request = to_musb_request(req);
1155 
1156 	trace_musb_req_free(request);
1157 	kfree(request);
1158 }
1159 
1160 /*
1161  * Context: controller locked, IRQs blocked.
1162  */
musb_ep_restart(struct musb * musb,struct musb_request * req)1163 void musb_ep_restart(struct musb *musb, struct musb_request *req)
1164 {
1165 	u16 csr;
1166 	void __iomem *epio = req->ep->hw_ep->regs;
1167 
1168 	trace_musb_req_start(req);
1169 	musb_ep_select(musb->mregs, req->epnum);
1170 	if (req->tx) {
1171 		txstate(musb, req);
1172 	} else {
1173 		csr = musb_readw(epio, MUSB_RXCSR);
1174 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1175 		musb_writew(epio, MUSB_RXCSR, csr);
1176 		musb_writew(epio, MUSB_RXCSR, csr);
1177 	}
1178 }
1179 
musb_ep_restart_resume_work(struct musb * musb,void * data)1180 static int musb_ep_restart_resume_work(struct musb *musb, void *data)
1181 {
1182 	struct musb_request *req = data;
1183 
1184 	musb_ep_restart(musb, req);
1185 
1186 	return 0;
1187 }
1188 
musb_gadget_queue(struct usb_ep * ep,struct usb_request * req,gfp_t gfp_flags)1189 static int musb_gadget_queue(struct usb_ep *ep, struct usb_request *req,
1190 			gfp_t gfp_flags)
1191 {
1192 	struct musb_ep		*musb_ep;
1193 	struct musb_request	*request;
1194 	struct musb		*musb;
1195 	int			status;
1196 	unsigned long		lockflags;
1197 
1198 	if (!ep || !req)
1199 		return -EINVAL;
1200 	if (!req->buf)
1201 		return -ENODATA;
1202 
1203 	musb_ep = to_musb_ep(ep);
1204 	musb = musb_ep->musb;
1205 
1206 	request = to_musb_request(req);
1207 	request->musb = musb;
1208 
1209 	if (request->ep != musb_ep)
1210 		return -EINVAL;
1211 
1212 	status = pm_runtime_get(musb->controller);
1213 	if ((status != -EINPROGRESS) && status < 0) {
1214 		dev_err(musb->controller,
1215 			"pm runtime get failed in %s\n",
1216 			__func__);
1217 		pm_runtime_put_noidle(musb->controller);
1218 
1219 		return status;
1220 	}
1221 	status = 0;
1222 
1223 	trace_musb_req_enq(request);
1224 
1225 	/* request is mine now... */
1226 	request->request.actual = 0;
1227 	request->request.status = -EINPROGRESS;
1228 	request->epnum = musb_ep->current_epnum;
1229 	request->tx = musb_ep->is_in;
1230 
1231 	map_dma_buffer(request, musb, musb_ep);
1232 
1233 	spin_lock_irqsave(&musb->lock, lockflags);
1234 
1235 	/* don't queue if the ep is down */
1236 	if (!musb_ep->desc) {
1237 		musb_dbg(musb, "req %p queued to %s while ep %s",
1238 				req, ep->name, "disabled");
1239 		status = -ESHUTDOWN;
1240 		unmap_dma_buffer(request, musb);
1241 		goto unlock;
1242 	}
1243 
1244 	/* add request to the list */
1245 	list_add_tail(&request->list, &musb_ep->req_list);
1246 
1247 	/* it this is the head of the queue, start i/o ... */
1248 	if (!musb_ep->busy && &request->list == musb_ep->req_list.next) {
1249 		status = musb_queue_resume_work(musb,
1250 						musb_ep_restart_resume_work,
1251 						request);
1252 		if (status < 0) {
1253 			dev_err(musb->controller, "%s resume work: %i\n",
1254 				__func__, status);
1255 			list_del(&request->list);
1256 		}
1257 	}
1258 
1259 unlock:
1260 	spin_unlock_irqrestore(&musb->lock, lockflags);
1261 	pm_runtime_mark_last_busy(musb->controller);
1262 	pm_runtime_put_autosuspend(musb->controller);
1263 
1264 	return status;
1265 }
1266 
musb_gadget_dequeue(struct usb_ep * ep,struct usb_request * request)1267 static int musb_gadget_dequeue(struct usb_ep *ep, struct usb_request *request)
1268 {
1269 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1270 	struct musb_request	*req = to_musb_request(request);
1271 	struct musb_request	*r;
1272 	unsigned long		flags;
1273 	int			status = 0;
1274 	struct musb		*musb = musb_ep->musb;
1275 
1276 	if (!ep || !request || req->ep != musb_ep)
1277 		return -EINVAL;
1278 
1279 	trace_musb_req_deq(req);
1280 
1281 	spin_lock_irqsave(&musb->lock, flags);
1282 
1283 	list_for_each_entry(r, &musb_ep->req_list, list) {
1284 		if (r == req)
1285 			break;
1286 	}
1287 	if (r != req) {
1288 		dev_err(musb->controller, "request %p not queued to %s\n",
1289 				request, ep->name);
1290 		status = -EINVAL;
1291 		goto done;
1292 	}
1293 
1294 	/* if the hardware doesn't have the request, easy ... */
1295 	if (musb_ep->req_list.next != &req->list || musb_ep->busy)
1296 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1297 
1298 	/* ... else abort the dma transfer ... */
1299 	else if (is_dma_capable() && musb_ep->dma) {
1300 		struct dma_controller	*c = musb->dma_controller;
1301 
1302 		musb_ep_select(musb->mregs, musb_ep->current_epnum);
1303 		if (c->channel_abort)
1304 			status = c->channel_abort(musb_ep->dma);
1305 		else
1306 			status = -EBUSY;
1307 		if (status == 0)
1308 			musb_g_giveback(musb_ep, request, -ECONNRESET);
1309 	} else {
1310 		/* NOTE: by sticking to easily tested hardware/driver states,
1311 		 * we leave counting of in-flight packets imprecise.
1312 		 */
1313 		musb_g_giveback(musb_ep, request, -ECONNRESET);
1314 	}
1315 
1316 done:
1317 	spin_unlock_irqrestore(&musb->lock, flags);
1318 	return status;
1319 }
1320 
1321 /*
1322  * Set or clear the halt bit of an endpoint. A halted endpoint won't tx/rx any
1323  * data but will queue requests.
1324  *
1325  * exported to ep0 code
1326  */
musb_gadget_set_halt(struct usb_ep * ep,int value)1327 static int musb_gadget_set_halt(struct usb_ep *ep, int value)
1328 {
1329 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1330 	u8			epnum = musb_ep->current_epnum;
1331 	struct musb		*musb = musb_ep->musb;
1332 	void __iomem		*epio = musb->endpoints[epnum].regs;
1333 	void __iomem		*mbase;
1334 	unsigned long		flags;
1335 	u16			csr;
1336 	struct musb_request	*request;
1337 	int			status = 0;
1338 
1339 	if (!ep)
1340 		return -EINVAL;
1341 	mbase = musb->mregs;
1342 
1343 	spin_lock_irqsave(&musb->lock, flags);
1344 
1345 	if ((USB_ENDPOINT_XFER_ISOC == musb_ep->type)) {
1346 		status = -EINVAL;
1347 		goto done;
1348 	}
1349 
1350 	musb_ep_select(mbase, epnum);
1351 
1352 	request = next_request(musb_ep);
1353 	if (value) {
1354 		if (request) {
1355 			musb_dbg(musb, "request in progress, cannot halt %s",
1356 			    ep->name);
1357 			status = -EAGAIN;
1358 			goto done;
1359 		}
1360 		/* Cannot portably stall with non-empty FIFO */
1361 		if (musb_ep->is_in) {
1362 			csr = musb_readw(epio, MUSB_TXCSR);
1363 			if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1364 				musb_dbg(musb, "FIFO busy, cannot halt %s",
1365 						ep->name);
1366 				status = -EAGAIN;
1367 				goto done;
1368 			}
1369 		}
1370 	} else
1371 		musb_ep->wedged = 0;
1372 
1373 	/* set/clear the stall and toggle bits */
1374 	musb_dbg(musb, "%s: %s stall", ep->name, value ? "set" : "clear");
1375 	if (musb_ep->is_in) {
1376 		csr = musb_readw(epio, MUSB_TXCSR);
1377 		csr |= MUSB_TXCSR_P_WZC_BITS
1378 			| MUSB_TXCSR_CLRDATATOG;
1379 		if (value)
1380 			csr |= MUSB_TXCSR_P_SENDSTALL;
1381 		else
1382 			csr &= ~(MUSB_TXCSR_P_SENDSTALL
1383 				| MUSB_TXCSR_P_SENTSTALL);
1384 		csr &= ~MUSB_TXCSR_TXPKTRDY;
1385 		musb_writew(epio, MUSB_TXCSR, csr);
1386 	} else {
1387 		csr = musb_readw(epio, MUSB_RXCSR);
1388 		csr |= MUSB_RXCSR_P_WZC_BITS
1389 			| MUSB_RXCSR_FLUSHFIFO
1390 			| MUSB_RXCSR_CLRDATATOG;
1391 		if (value)
1392 			csr |= MUSB_RXCSR_P_SENDSTALL;
1393 		else
1394 			csr &= ~(MUSB_RXCSR_P_SENDSTALL
1395 				| MUSB_RXCSR_P_SENTSTALL);
1396 		musb_writew(epio, MUSB_RXCSR, csr);
1397 	}
1398 
1399 	/* maybe start the first request in the queue */
1400 	if (!musb_ep->busy && !value && request) {
1401 		musb_dbg(musb, "restarting the request");
1402 		musb_ep_restart(musb, request);
1403 	}
1404 
1405 done:
1406 	spin_unlock_irqrestore(&musb->lock, flags);
1407 	return status;
1408 }
1409 
1410 /*
1411  * Sets the halt feature with the clear requests ignored
1412  */
musb_gadget_set_wedge(struct usb_ep * ep)1413 static int musb_gadget_set_wedge(struct usb_ep *ep)
1414 {
1415 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1416 
1417 	if (!ep)
1418 		return -EINVAL;
1419 
1420 	musb_ep->wedged = 1;
1421 
1422 	return usb_ep_set_halt(ep);
1423 }
1424 
musb_gadget_fifo_status(struct usb_ep * ep)1425 static int musb_gadget_fifo_status(struct usb_ep *ep)
1426 {
1427 	struct musb_ep		*musb_ep = to_musb_ep(ep);
1428 	void __iomem		*epio = musb_ep->hw_ep->regs;
1429 	int			retval = -EINVAL;
1430 
1431 	if (musb_ep->desc && !musb_ep->is_in) {
1432 		struct musb		*musb = musb_ep->musb;
1433 		int			epnum = musb_ep->current_epnum;
1434 		void __iomem		*mbase = musb->mregs;
1435 		unsigned long		flags;
1436 
1437 		spin_lock_irqsave(&musb->lock, flags);
1438 
1439 		musb_ep_select(mbase, epnum);
1440 		/* FIXME return zero unless RXPKTRDY is set */
1441 		retval = musb_readw(epio, MUSB_RXCOUNT);
1442 
1443 		spin_unlock_irqrestore(&musb->lock, flags);
1444 	}
1445 	return retval;
1446 }
1447 
musb_gadget_fifo_flush(struct usb_ep * ep)1448 static void musb_gadget_fifo_flush(struct usb_ep *ep)
1449 {
1450 	struct musb_ep	*musb_ep = to_musb_ep(ep);
1451 	struct musb	*musb = musb_ep->musb;
1452 	u8		epnum = musb_ep->current_epnum;
1453 	void __iomem	*epio = musb->endpoints[epnum].regs;
1454 	void __iomem	*mbase;
1455 	unsigned long	flags;
1456 	u16		csr;
1457 
1458 	mbase = musb->mregs;
1459 
1460 	spin_lock_irqsave(&musb->lock, flags);
1461 	musb_ep_select(mbase, (u8) epnum);
1462 
1463 	/* disable interrupts */
1464 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe & ~(1 << epnum));
1465 
1466 	if (musb_ep->is_in) {
1467 		csr = musb_readw(epio, MUSB_TXCSR);
1468 		if (csr & MUSB_TXCSR_FIFONOTEMPTY) {
1469 			csr |= MUSB_TXCSR_FLUSHFIFO | MUSB_TXCSR_P_WZC_BITS;
1470 			/*
1471 			 * Setting both TXPKTRDY and FLUSHFIFO makes controller
1472 			 * to interrupt current FIFO loading, but not flushing
1473 			 * the already loaded ones.
1474 			 */
1475 			csr &= ~MUSB_TXCSR_TXPKTRDY;
1476 			musb_writew(epio, MUSB_TXCSR, csr);
1477 			/* REVISIT may be inappropriate w/o FIFONOTEMPTY ... */
1478 			musb_writew(epio, MUSB_TXCSR, csr);
1479 		}
1480 	} else {
1481 		csr = musb_readw(epio, MUSB_RXCSR);
1482 		csr |= MUSB_RXCSR_FLUSHFIFO | MUSB_RXCSR_P_WZC_BITS;
1483 		musb_writew(epio, MUSB_RXCSR, csr);
1484 		musb_writew(epio, MUSB_RXCSR, csr);
1485 	}
1486 
1487 	/* re-enable interrupt */
1488 	musb_writew(mbase, MUSB_INTRTXE, musb->intrtxe);
1489 	spin_unlock_irqrestore(&musb->lock, flags);
1490 }
1491 
1492 static const struct usb_ep_ops musb_ep_ops = {
1493 	.enable		= musb_gadget_enable,
1494 	.disable	= musb_gadget_disable,
1495 	.alloc_request	= musb_alloc_request,
1496 	.free_request	= musb_free_request,
1497 	.queue		= musb_gadget_queue,
1498 	.dequeue	= musb_gadget_dequeue,
1499 	.set_halt	= musb_gadget_set_halt,
1500 	.set_wedge	= musb_gadget_set_wedge,
1501 	.fifo_status	= musb_gadget_fifo_status,
1502 	.fifo_flush	= musb_gadget_fifo_flush
1503 };
1504 
1505 /* ----------------------------------------------------------------------- */
1506 
musb_gadget_get_frame(struct usb_gadget * gadget)1507 static int musb_gadget_get_frame(struct usb_gadget *gadget)
1508 {
1509 	struct musb	*musb = gadget_to_musb(gadget);
1510 
1511 	return (int)musb_readw(musb->mregs, MUSB_FRAME);
1512 }
1513 
musb_gadget_wakeup(struct usb_gadget * gadget)1514 static int musb_gadget_wakeup(struct usb_gadget *gadget)
1515 {
1516 	struct musb	*musb = gadget_to_musb(gadget);
1517 	void __iomem	*mregs = musb->mregs;
1518 	unsigned long	flags;
1519 	int		status = -EINVAL;
1520 	u8		power, devctl;
1521 	int		retries;
1522 
1523 	spin_lock_irqsave(&musb->lock, flags);
1524 
1525 	switch (musb_get_state(musb)) {
1526 	case OTG_STATE_B_PERIPHERAL:
1527 		/* NOTE:  OTG state machine doesn't include B_SUSPENDED;
1528 		 * that's part of the standard usb 1.1 state machine, and
1529 		 * doesn't affect OTG transitions.
1530 		 */
1531 		if (musb->may_wakeup && musb->is_suspended)
1532 			break;
1533 		goto done;
1534 	case OTG_STATE_B_IDLE:
1535 		/* Start SRP ... OTG not required. */
1536 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1537 		musb_dbg(musb, "Sending SRP: devctl: %02x", devctl);
1538 		devctl |= MUSB_DEVCTL_SESSION;
1539 		musb_writeb(mregs, MUSB_DEVCTL, devctl);
1540 		devctl = musb_readb(mregs, MUSB_DEVCTL);
1541 		retries = 100;
1542 		while (!(devctl & MUSB_DEVCTL_SESSION)) {
1543 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1544 			if (retries-- < 1)
1545 				break;
1546 		}
1547 		retries = 10000;
1548 		while (devctl & MUSB_DEVCTL_SESSION) {
1549 			devctl = musb_readb(mregs, MUSB_DEVCTL);
1550 			if (retries-- < 1)
1551 				break;
1552 		}
1553 
1554 		if (musb->xceiv) {
1555 			spin_unlock_irqrestore(&musb->lock, flags);
1556 			otg_start_srp(musb->xceiv->otg);
1557 			spin_lock_irqsave(&musb->lock, flags);
1558 		}
1559 
1560 		/* Block idling for at least 1s */
1561 		musb_platform_try_idle(musb,
1562 			jiffies + msecs_to_jiffies(1 * HZ));
1563 
1564 		status = 0;
1565 		goto done;
1566 	default:
1567 		musb_dbg(musb, "Unhandled wake: %s",
1568 			 musb_otg_state_string(musb));
1569 		goto done;
1570 	}
1571 
1572 	status = 0;
1573 
1574 	power = musb_readb(mregs, MUSB_POWER);
1575 	power |= MUSB_POWER_RESUME;
1576 	musb_writeb(mregs, MUSB_POWER, power);
1577 	musb_dbg(musb, "issue wakeup");
1578 
1579 	/* FIXME do this next chunk in a timer callback, no udelay */
1580 	mdelay(2);
1581 
1582 	power = musb_readb(mregs, MUSB_POWER);
1583 	power &= ~MUSB_POWER_RESUME;
1584 	musb_writeb(mregs, MUSB_POWER, power);
1585 done:
1586 	spin_unlock_irqrestore(&musb->lock, flags);
1587 	return status;
1588 }
1589 
1590 static int
musb_gadget_set_self_powered(struct usb_gadget * gadget,int is_selfpowered)1591 musb_gadget_set_self_powered(struct usb_gadget *gadget, int is_selfpowered)
1592 {
1593 	gadget->is_selfpowered = !!is_selfpowered;
1594 	return 0;
1595 }
1596 
musb_pullup(struct musb * musb,int is_on)1597 static void musb_pullup(struct musb *musb, int is_on)
1598 {
1599 	u8 power;
1600 
1601 	power = musb_readb(musb->mregs, MUSB_POWER);
1602 	if (is_on)
1603 		power |= MUSB_POWER_SOFTCONN;
1604 	else
1605 		power &= ~MUSB_POWER_SOFTCONN;
1606 
1607 	/* FIXME if on, HdrcStart; if off, HdrcStop */
1608 
1609 	musb_dbg(musb, "gadget D+ pullup %s",
1610 		str_on_off(is_on));
1611 	musb_writeb(musb->mregs, MUSB_POWER, power);
1612 }
1613 
1614 #if 0
1615 static int musb_gadget_vbus_session(struct usb_gadget *gadget, int is_active)
1616 {
1617 	musb_dbg(musb, "<= %s =>\n", __func__);
1618 
1619 	/*
1620 	 * FIXME iff driver's softconnect flag is set (as it is during probe,
1621 	 * though that can clear it), just musb_pullup().
1622 	 */
1623 
1624 	return -EINVAL;
1625 }
1626 #endif
1627 
musb_gadget_vbus_draw(struct usb_gadget * gadget,unsigned mA)1628 static int musb_gadget_vbus_draw(struct usb_gadget *gadget, unsigned mA)
1629 {
1630 	struct musb	*musb = gadget_to_musb(gadget);
1631 
1632 	return usb_phy_set_power(musb->xceiv, mA);
1633 }
1634 
musb_gadget_work(struct work_struct * work)1635 static void musb_gadget_work(struct work_struct *work)
1636 {
1637 	struct musb *musb;
1638 	unsigned long flags;
1639 
1640 	musb = container_of(work, struct musb, gadget_work.work);
1641 	pm_runtime_get_sync(musb->controller);
1642 	spin_lock_irqsave(&musb->lock, flags);
1643 	musb_pullup(musb, musb->softconnect);
1644 	spin_unlock_irqrestore(&musb->lock, flags);
1645 	pm_runtime_mark_last_busy(musb->controller);
1646 	pm_runtime_put_autosuspend(musb->controller);
1647 }
1648 
musb_gadget_pullup(struct usb_gadget * gadget,int is_on)1649 static int musb_gadget_pullup(struct usb_gadget *gadget, int is_on)
1650 {
1651 	struct musb	*musb = gadget_to_musb(gadget);
1652 	unsigned long	flags;
1653 
1654 	is_on = !!is_on;
1655 
1656 	/* NOTE: this assumes we are sensing vbus; we'd rather
1657 	 * not pullup unless the B-session is active.
1658 	 */
1659 	spin_lock_irqsave(&musb->lock, flags);
1660 	if (is_on != musb->softconnect) {
1661 		musb->softconnect = is_on;
1662 		schedule_delayed_work(&musb->gadget_work, 0);
1663 	}
1664 	spin_unlock_irqrestore(&musb->lock, flags);
1665 
1666 	return 0;
1667 }
1668 
1669 static int musb_gadget_start(struct usb_gadget *g,
1670 		struct usb_gadget_driver *driver);
1671 static int musb_gadget_stop(struct usb_gadget *g);
1672 
1673 static const struct usb_gadget_ops musb_gadget_operations = {
1674 	.get_frame		= musb_gadget_get_frame,
1675 	.wakeup			= musb_gadget_wakeup,
1676 	.set_selfpowered	= musb_gadget_set_self_powered,
1677 	/* .vbus_session		= musb_gadget_vbus_session, */
1678 	.vbus_draw		= musb_gadget_vbus_draw,
1679 	.pullup			= musb_gadget_pullup,
1680 	.udc_start		= musb_gadget_start,
1681 	.udc_stop		= musb_gadget_stop,
1682 };
1683 
1684 /* ----------------------------------------------------------------------- */
1685 
1686 /* Registration */
1687 
1688 /* Only this registration code "knows" the rule (from USB standards)
1689  * about there being only one external upstream port.  It assumes
1690  * all peripheral ports are external...
1691  */
1692 
1693 static void
init_peripheral_ep(struct musb * musb,struct musb_ep * ep,u8 epnum,int is_in)1694 init_peripheral_ep(struct musb *musb, struct musb_ep *ep, u8 epnum, int is_in)
1695 {
1696 	struct musb_hw_ep	*hw_ep = musb->endpoints + epnum;
1697 
1698 	memset(ep, 0, sizeof *ep);
1699 
1700 	ep->current_epnum = epnum;
1701 	ep->musb = musb;
1702 	ep->hw_ep = hw_ep;
1703 	ep->is_in = is_in;
1704 
1705 	INIT_LIST_HEAD(&ep->req_list);
1706 
1707 	sprintf(ep->name, "ep%d%s", epnum,
1708 			(!epnum || hw_ep->is_shared_fifo) ? "" : (
1709 				is_in ? "in" : "out"));
1710 	ep->end_point.name = ep->name;
1711 	INIT_LIST_HEAD(&ep->end_point.ep_list);
1712 	if (!epnum) {
1713 		usb_ep_set_maxpacket_limit(&ep->end_point, 64);
1714 		ep->end_point.caps.type_control = true;
1715 		ep->end_point.ops = &musb_g_ep0_ops;
1716 		musb->g.ep0 = &ep->end_point;
1717 	} else {
1718 		if (is_in)
1719 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_tx);
1720 		else
1721 			usb_ep_set_maxpacket_limit(&ep->end_point, hw_ep->max_packet_sz_rx);
1722 		ep->end_point.caps.type_iso = true;
1723 		ep->end_point.caps.type_bulk = true;
1724 		ep->end_point.caps.type_int = true;
1725 		ep->end_point.ops = &musb_ep_ops;
1726 		list_add_tail(&ep->end_point.ep_list, &musb->g.ep_list);
1727 	}
1728 
1729 	if (!epnum || hw_ep->is_shared_fifo) {
1730 		ep->end_point.caps.dir_in = true;
1731 		ep->end_point.caps.dir_out = true;
1732 	} else if (is_in)
1733 		ep->end_point.caps.dir_in = true;
1734 	else
1735 		ep->end_point.caps.dir_out = true;
1736 }
1737 
1738 /*
1739  * Initialize the endpoints exposed to peripheral drivers, with backlinks
1740  * to the rest of the driver state.
1741  */
musb_g_init_endpoints(struct musb * musb)1742 static inline void musb_g_init_endpoints(struct musb *musb)
1743 {
1744 	u8			epnum;
1745 	struct musb_hw_ep	*hw_ep;
1746 
1747 	/* initialize endpoint list just once */
1748 	INIT_LIST_HEAD(&(musb->g.ep_list));
1749 
1750 	for (epnum = 0, hw_ep = musb->endpoints;
1751 			epnum < musb->nr_endpoints;
1752 			epnum++, hw_ep++) {
1753 		if (hw_ep->is_shared_fifo /* || !epnum */) {
1754 			init_peripheral_ep(musb, &hw_ep->ep_in, epnum, 0);
1755 		} else {
1756 			if (hw_ep->max_packet_sz_tx) {
1757 				init_peripheral_ep(musb, &hw_ep->ep_in,
1758 							epnum, 1);
1759 			}
1760 			if (hw_ep->max_packet_sz_rx) {
1761 				init_peripheral_ep(musb, &hw_ep->ep_out,
1762 							epnum, 0);
1763 			}
1764 		}
1765 	}
1766 }
1767 
1768 /* called once during driver setup to initialize and link into
1769  * the driver model; memory is zeroed.
1770  */
musb_gadget_setup(struct musb * musb)1771 int musb_gadget_setup(struct musb *musb)
1772 {
1773 	int status;
1774 
1775 	/* REVISIT minor race:  if (erroneously) setting up two
1776 	 * musb peripherals at the same time, only the bus lock
1777 	 * is probably held.
1778 	 */
1779 
1780 	musb->g.ops = &musb_gadget_operations;
1781 	musb->g.max_speed = USB_SPEED_HIGH;
1782 	musb->g.speed = USB_SPEED_UNKNOWN;
1783 
1784 	MUSB_DEV_MODE(musb);
1785 	musb_set_state(musb, OTG_STATE_B_IDLE);
1786 
1787 	/* this "gadget" abstracts/virtualizes the controller */
1788 	musb->g.name = musb_driver_name;
1789 	/* don't support otg protocols */
1790 	musb->g.is_otg = 0;
1791 	INIT_DELAYED_WORK(&musb->gadget_work, musb_gadget_work);
1792 	musb_g_init_endpoints(musb);
1793 
1794 	musb->is_active = 0;
1795 	musb_platform_try_idle(musb, 0);
1796 
1797 	status = usb_add_gadget_udc(musb->controller, &musb->g);
1798 	if (status)
1799 		goto err;
1800 
1801 	return 0;
1802 err:
1803 	musb->g.dev.parent = NULL;
1804 	device_unregister(&musb->g.dev);
1805 	return status;
1806 }
1807 
musb_gadget_cleanup(struct musb * musb)1808 void musb_gadget_cleanup(struct musb *musb)
1809 {
1810 	if (musb->port_mode == MUSB_HOST)
1811 		return;
1812 
1813 	cancel_delayed_work_sync(&musb->gadget_work);
1814 	usb_del_gadget_udc(&musb->g);
1815 }
1816 
1817 /*
1818  * Register the gadget driver. Used by gadget drivers when
1819  * registering themselves with the controller.
1820  *
1821  * -EINVAL something went wrong (not driver)
1822  * -EBUSY another gadget is already using the controller
1823  * -ENOMEM no memory to perform the operation
1824  *
1825  * @param driver the gadget driver
1826  * @return <0 if error, 0 if everything is fine
1827  */
musb_gadget_start(struct usb_gadget * g,struct usb_gadget_driver * driver)1828 static int musb_gadget_start(struct usb_gadget *g,
1829 		struct usb_gadget_driver *driver)
1830 {
1831 	struct musb		*musb = gadget_to_musb(g);
1832 	unsigned long		flags;
1833 	int			retval = 0;
1834 
1835 	if (driver->max_speed < USB_SPEED_HIGH) {
1836 		retval = -EINVAL;
1837 		goto err;
1838 	}
1839 
1840 	pm_runtime_get_sync(musb->controller);
1841 
1842 	musb->softconnect = 0;
1843 	musb->gadget_driver = driver;
1844 
1845 	spin_lock_irqsave(&musb->lock, flags);
1846 	musb->is_active = 1;
1847 
1848 	if (musb->xceiv)
1849 		otg_set_peripheral(musb->xceiv->otg, &musb->g);
1850 	else
1851 		phy_set_mode(musb->phy, PHY_MODE_USB_DEVICE);
1852 
1853 	musb_set_state(musb, OTG_STATE_B_IDLE);
1854 	spin_unlock_irqrestore(&musb->lock, flags);
1855 
1856 	musb_start(musb);
1857 
1858 	/* REVISIT:  funcall to other code, which also
1859 	 * handles power budgeting ... this way also
1860 	 * ensures HdrcStart is indirectly called.
1861 	 */
1862 	if (musb->xceiv && musb->xceiv->last_event == USB_EVENT_ID)
1863 		musb_platform_set_vbus(musb, 1);
1864 
1865 	pm_runtime_mark_last_busy(musb->controller);
1866 	pm_runtime_put_autosuspend(musb->controller);
1867 
1868 	return 0;
1869 
1870 err:
1871 	return retval;
1872 }
1873 
1874 /*
1875  * Unregister the gadget driver. Used by gadget drivers when
1876  * unregistering themselves from the controller.
1877  *
1878  * @param driver the gadget driver to unregister
1879  */
musb_gadget_stop(struct usb_gadget * g)1880 static int musb_gadget_stop(struct usb_gadget *g)
1881 {
1882 	struct musb	*musb = gadget_to_musb(g);
1883 	unsigned long	flags;
1884 
1885 	pm_runtime_get_sync(musb->controller);
1886 
1887 	/*
1888 	 * REVISIT always use otg_set_peripheral() here too;
1889 	 * this needs to shut down the OTG engine.
1890 	 */
1891 
1892 	spin_lock_irqsave(&musb->lock, flags);
1893 
1894 	musb_hnp_stop(musb);
1895 
1896 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1897 
1898 	musb_set_state(musb, OTG_STATE_UNDEFINED);
1899 	musb_stop(musb);
1900 
1901 	if (musb->xceiv)
1902 		otg_set_peripheral(musb->xceiv->otg, NULL);
1903 	else
1904 		phy_set_mode(musb->phy, PHY_MODE_INVALID);
1905 
1906 	musb->is_active = 0;
1907 	musb->gadget_driver = NULL;
1908 	musb_platform_try_idle(musb, 0);
1909 	spin_unlock_irqrestore(&musb->lock, flags);
1910 
1911 	/*
1912 	 * FIXME we need to be able to register another
1913 	 * gadget driver here and have everything work;
1914 	 * that currently misbehaves.
1915 	 */
1916 
1917 	/* Force check of devctl register for PM runtime */
1918 	pm_runtime_mark_last_busy(musb->controller);
1919 	pm_runtime_put_autosuspend(musb->controller);
1920 
1921 	return 0;
1922 }
1923 
1924 /* ----------------------------------------------------------------------- */
1925 
1926 /* lifecycle operations called through plat_uds.c */
1927 
musb_g_resume(struct musb * musb)1928 void musb_g_resume(struct musb *musb)
1929 {
1930 	musb->is_suspended = 0;
1931 	switch (musb_get_state(musb)) {
1932 	case OTG_STATE_B_IDLE:
1933 		break;
1934 	case OTG_STATE_B_WAIT_ACON:
1935 	case OTG_STATE_B_PERIPHERAL:
1936 		musb->is_active = 1;
1937 		if (musb->gadget_driver && musb->gadget_driver->resume) {
1938 			spin_unlock(&musb->lock);
1939 			musb->gadget_driver->resume(&musb->g);
1940 			spin_lock(&musb->lock);
1941 		}
1942 		break;
1943 	default:
1944 		WARNING("unhandled RESUME transition (%s)\n",
1945 			musb_otg_state_string(musb));
1946 	}
1947 }
1948 
1949 /* called when SOF packets stop for 3+ msec */
musb_g_suspend(struct musb * musb)1950 void musb_g_suspend(struct musb *musb)
1951 {
1952 	u8	devctl;
1953 
1954 	devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
1955 	musb_dbg(musb, "musb_g_suspend: devctl %02x", devctl);
1956 
1957 	switch (musb_get_state(musb)) {
1958 	case OTG_STATE_B_IDLE:
1959 		if ((devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS)
1960 			musb_set_state(musb, OTG_STATE_B_PERIPHERAL);
1961 		break;
1962 	case OTG_STATE_B_PERIPHERAL:
1963 		musb->is_suspended = 1;
1964 		if (musb->gadget_driver && musb->gadget_driver->suspend) {
1965 			spin_unlock(&musb->lock);
1966 			musb->gadget_driver->suspend(&musb->g);
1967 			spin_lock(&musb->lock);
1968 		}
1969 		break;
1970 	default:
1971 		/* REVISIT if B_HOST, clear DEVCTL.HOSTREQ;
1972 		 * A_PERIPHERAL may need care too
1973 		 */
1974 		WARNING("unhandled SUSPEND transition (%s)",
1975 			musb_otg_state_string(musb));
1976 	}
1977 }
1978 
1979 /* Called during SRP */
musb_g_wakeup(struct musb * musb)1980 void musb_g_wakeup(struct musb *musb)
1981 {
1982 	musb_gadget_wakeup(&musb->g);
1983 }
1984 
1985 /* called when VBUS drops below session threshold, and in other cases */
musb_g_disconnect(struct musb * musb)1986 void musb_g_disconnect(struct musb *musb)
1987 {
1988 	void __iomem	*mregs = musb->mregs;
1989 	u8	devctl = musb_readb(mregs, MUSB_DEVCTL);
1990 
1991 	musb_dbg(musb, "musb_g_disconnect: devctl %02x", devctl);
1992 
1993 	/* clear HR */
1994 	musb_writeb(mregs, MUSB_DEVCTL, devctl & MUSB_DEVCTL_SESSION);
1995 
1996 	/* don't draw vbus until new b-default session */
1997 	(void) musb_gadget_vbus_draw(&musb->g, 0);
1998 
1999 	musb->g.speed = USB_SPEED_UNKNOWN;
2000 	if (musb->gadget_driver && musb->gadget_driver->disconnect) {
2001 		spin_unlock(&musb->lock);
2002 		musb->gadget_driver->disconnect(&musb->g);
2003 		spin_lock(&musb->lock);
2004 	}
2005 
2006 	switch (musb_get_state(musb)) {
2007 	default:
2008 		musb_dbg(musb, "Unhandled disconnect %s, setting a_idle",
2009 			 musb_otg_state_string(musb));
2010 		musb_set_state(musb, OTG_STATE_A_IDLE);
2011 		MUSB_HST_MODE(musb);
2012 		break;
2013 	case OTG_STATE_A_PERIPHERAL:
2014 		musb_set_state(musb, OTG_STATE_A_WAIT_BCON);
2015 		MUSB_HST_MODE(musb);
2016 		break;
2017 	case OTG_STATE_B_WAIT_ACON:
2018 	case OTG_STATE_B_HOST:
2019 	case OTG_STATE_B_PERIPHERAL:
2020 	case OTG_STATE_B_IDLE:
2021 		musb_set_state(musb, OTG_STATE_B_IDLE);
2022 		break;
2023 	case OTG_STATE_B_SRP_INIT:
2024 		break;
2025 	}
2026 
2027 	musb->is_active = 0;
2028 }
2029 
musb_g_reset(struct musb * musb)2030 void musb_g_reset(struct musb *musb)
2031 __releases(musb->lock)
2032 __acquires(musb->lock)
2033 {
2034 	void __iomem	*mbase = musb->mregs;
2035 	u8		devctl = musb_readb(mbase, MUSB_DEVCTL);
2036 	u8		power;
2037 
2038 	musb_dbg(musb, "<== %s driver '%s'",
2039 			(devctl & MUSB_DEVCTL_BDEVICE)
2040 				? "B-Device" : "A-Device",
2041 			musb->gadget_driver
2042 				? musb->gadget_driver->driver.name
2043 				: NULL
2044 			);
2045 
2046 	/* report reset, if we didn't already (flushing EP state) */
2047 	if (musb->gadget_driver && musb->g.speed != USB_SPEED_UNKNOWN) {
2048 		spin_unlock(&musb->lock);
2049 		usb_gadget_udc_reset(&musb->g, musb->gadget_driver);
2050 		spin_lock(&musb->lock);
2051 	}
2052 
2053 	/* clear HR */
2054 	else if (devctl & MUSB_DEVCTL_HR)
2055 		musb_writeb(mbase, MUSB_DEVCTL, MUSB_DEVCTL_SESSION);
2056 
2057 
2058 	/* what speed did we negotiate? */
2059 	power = musb_readb(mbase, MUSB_POWER);
2060 	musb->g.speed = (power & MUSB_POWER_HSMODE)
2061 			? USB_SPEED_HIGH : USB_SPEED_FULL;
2062 
2063 	/* start in USB_STATE_DEFAULT */
2064 	musb->is_active = 1;
2065 	musb->is_suspended = 0;
2066 	MUSB_DEV_MODE(musb);
2067 	musb->address = 0;
2068 	musb->ep0_state = MUSB_EP0_STAGE_SETUP;
2069 
2070 	musb->may_wakeup = 0;
2071 	musb->g.b_hnp_enable = 0;
2072 	musb->g.a_alt_hnp_support = 0;
2073 	musb->g.a_hnp_support = 0;
2074 	musb->g.quirk_zlp_not_supp = 1;
2075 
2076 	/* Normal reset, as B-Device;
2077 	 * or else after HNP, as A-Device
2078 	 */
2079 	if (!musb->g.is_otg) {
2080 		/* USB device controllers that are not OTG compatible
2081 		 * may not have DEVCTL register in silicon.
2082 		 * In that case, do not rely on devctl for setting
2083 		 * peripheral mode.
2084 		 */
2085 		musb_set_state(musb, OTG_STATE_B_PERIPHERAL);
2086 		musb->g.is_a_peripheral = 0;
2087 	} else if (devctl & MUSB_DEVCTL_BDEVICE) {
2088 		musb_set_state(musb, OTG_STATE_B_PERIPHERAL);
2089 		musb->g.is_a_peripheral = 0;
2090 	} else {
2091 		musb_set_state(musb, OTG_STATE_A_PERIPHERAL);
2092 		musb->g.is_a_peripheral = 1;
2093 	}
2094 
2095 	/* start with default limits on VBUS power draw */
2096 	(void) musb_gadget_vbus_draw(&musb->g, 8);
2097 }
2098