xref: /linux/drivers/usb/dwc3/ep0.c (revision b43ab901d671e3e3cad425ea5e9a3c74e266dcdd)
1 /**
2  * ep0.c - DesignWare USB3 DRD Controller Endpoint 0 Handling
3  *
4  * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com
5  *
6  * Authors: Felipe Balbi <balbi@ti.com>,
7  *	    Sebastian Andrzej Siewior <bigeasy@linutronix.de>
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions, and the following disclaimer,
14  *    without modification.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. The names of the above-listed copyright holders may not be used
19  *    to endorse or promote products derived from this software without
20  *    specific prior written permission.
21  *
22  * ALTERNATIVELY, this software may be distributed under the terms of the
23  * GNU General Public License ("GPL") version 2, as published by the Free
24  * Software Foundation.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27  * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
28  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
30  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <linux/kernel.h>
40 #include <linux/slab.h>
41 #include <linux/spinlock.h>
42 #include <linux/platform_device.h>
43 #include <linux/pm_runtime.h>
44 #include <linux/interrupt.h>
45 #include <linux/io.h>
46 #include <linux/list.h>
47 #include <linux/dma-mapping.h>
48 
49 #include <linux/usb/ch9.h>
50 #include <linux/usb/gadget.h>
51 #include <linux/usb/composite.h>
52 
53 #include "core.h"
54 #include "gadget.h"
55 #include "io.h"
56 
57 static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum);
58 
59 static const char *dwc3_ep0_state_string(enum dwc3_ep0_state state)
60 {
61 	switch (state) {
62 	case EP0_UNCONNECTED:
63 		return "Unconnected";
64 	case EP0_SETUP_PHASE:
65 		return "Setup Phase";
66 	case EP0_DATA_PHASE:
67 		return "Data Phase";
68 	case EP0_STATUS_PHASE:
69 		return "Status Phase";
70 	default:
71 		return "UNKNOWN";
72 	}
73 }
74 
75 static int dwc3_ep0_start_trans(struct dwc3 *dwc, u8 epnum, dma_addr_t buf_dma,
76 		u32 len, u32 type)
77 {
78 	struct dwc3_gadget_ep_cmd_params params;
79 	struct dwc3_trb_hw		*trb_hw;
80 	struct dwc3_trb			trb;
81 	struct dwc3_ep			*dep;
82 
83 	int				ret;
84 
85 	dep = dwc->eps[epnum];
86 	if (dep->flags & DWC3_EP_BUSY) {
87 		dev_vdbg(dwc->dev, "%s: still busy\n", dep->name);
88 		return 0;
89 	}
90 
91 	trb_hw = dwc->ep0_trb;
92 	memset(&trb, 0, sizeof(trb));
93 
94 	trb.trbctl = type;
95 	trb.bplh = buf_dma;
96 	trb.length = len;
97 
98 	trb.hwo	= 1;
99 	trb.lst	= 1;
100 	trb.ioc	= 1;
101 	trb.isp_imi = 1;
102 
103 	dwc3_trb_to_hw(&trb, trb_hw);
104 
105 	memset(&params, 0, sizeof(params));
106 	params.param0 = upper_32_bits(dwc->ep0_trb_addr);
107 	params.param1 = lower_32_bits(dwc->ep0_trb_addr);
108 
109 	ret = dwc3_send_gadget_ep_cmd(dwc, dep->number,
110 			DWC3_DEPCMD_STARTTRANSFER, &params);
111 	if (ret < 0) {
112 		dev_dbg(dwc->dev, "failed to send STARTTRANSFER command\n");
113 		return ret;
114 	}
115 
116 	dep->flags |= DWC3_EP_BUSY;
117 	dep->res_trans_idx = dwc3_gadget_ep_get_transfer_index(dwc,
118 			dep->number);
119 
120 	dwc->ep0_next_event = DWC3_EP0_COMPLETE;
121 
122 	return 0;
123 }
124 
125 static int __dwc3_gadget_ep0_queue(struct dwc3_ep *dep,
126 		struct dwc3_request *req)
127 {
128 	struct dwc3		*dwc = dep->dwc;
129 	u32			type;
130 	int			ret = 0;
131 
132 	req->request.actual	= 0;
133 	req->request.status	= -EINPROGRESS;
134 	req->epnum		= dep->number;
135 
136 	list_add_tail(&req->list, &dep->request_list);
137 
138 	/*
139 	 * Gadget driver might not be quick enough to queue a request
140 	 * before we get a Transfer Not Ready event on this endpoint.
141 	 *
142 	 * In that case, we will set DWC3_EP_PENDING_REQUEST. When that
143 	 * flag is set, it's telling us that as soon as Gadget queues the
144 	 * required request, we should kick the transfer here because the
145 	 * IRQ we were waiting for is long gone.
146 	 */
147 	if (dep->flags & DWC3_EP_PENDING_REQUEST) {
148 		unsigned	direction;
149 
150 		direction = !!(dep->flags & DWC3_EP0_DIR_IN);
151 
152 		if (dwc->ep0state == EP0_STATUS_PHASE) {
153 			type = dwc->three_stage_setup
154 				? DWC3_TRBCTL_CONTROL_STATUS3
155 				: DWC3_TRBCTL_CONTROL_STATUS2;
156 		} else if (dwc->ep0state == EP0_DATA_PHASE) {
157 			type = DWC3_TRBCTL_CONTROL_DATA;
158 		} else {
159 			/* should never happen */
160 			WARN_ON(1);
161 			return 0;
162 		}
163 
164 		ret = dwc3_ep0_start_trans(dwc, direction,
165 				req->request.dma, req->request.length, type);
166 		dep->flags &= ~(DWC3_EP_PENDING_REQUEST |
167 				DWC3_EP0_DIR_IN);
168 	} else if (dwc->delayed_status) {
169 		dwc->delayed_status = false;
170 
171 		if (dwc->ep0state == EP0_STATUS_PHASE)
172 			dwc3_ep0_do_control_status(dwc, 1);
173 		else
174 			dev_dbg(dwc->dev, "too early for delayed status\n");
175 	}
176 
177 	return ret;
178 }
179 
180 int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request,
181 		gfp_t gfp_flags)
182 {
183 	struct dwc3_request		*req = to_dwc3_request(request);
184 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
185 	struct dwc3			*dwc = dep->dwc;
186 
187 	unsigned long			flags;
188 
189 	int				ret;
190 
191 	spin_lock_irqsave(&dwc->lock, flags);
192 	if (!dep->desc) {
193 		dev_dbg(dwc->dev, "trying to queue request %p to disabled %s\n",
194 				request, dep->name);
195 		ret = -ESHUTDOWN;
196 		goto out;
197 	}
198 
199 	/* we share one TRB for ep0/1 */
200 	if (!list_empty(&dep->request_list)) {
201 		ret = -EBUSY;
202 		goto out;
203 	}
204 
205 	dev_vdbg(dwc->dev, "queueing request %p to %s length %d, state '%s'\n",
206 			request, dep->name, request->length,
207 			dwc3_ep0_state_string(dwc->ep0state));
208 
209 	ret = __dwc3_gadget_ep0_queue(dep, req);
210 
211 out:
212 	spin_unlock_irqrestore(&dwc->lock, flags);
213 
214 	return ret;
215 }
216 
217 static void dwc3_ep0_stall_and_restart(struct dwc3 *dwc)
218 {
219 	struct dwc3_ep		*dep = dwc->eps[0];
220 
221 	/* stall is always issued on EP0 */
222 	__dwc3_gadget_ep_set_halt(dep, 1);
223 	dep->flags = DWC3_EP_ENABLED;
224 	dwc->delayed_status = false;
225 
226 	if (!list_empty(&dep->request_list)) {
227 		struct dwc3_request	*req;
228 
229 		req = next_request(&dep->request_list);
230 		dwc3_gadget_giveback(dep, req, -ECONNRESET);
231 	}
232 
233 	dwc->ep0state = EP0_SETUP_PHASE;
234 	dwc3_ep0_out_start(dwc);
235 }
236 
237 void dwc3_ep0_out_start(struct dwc3 *dwc)
238 {
239 	int				ret;
240 
241 	ret = dwc3_ep0_start_trans(dwc, 0, dwc->ctrl_req_addr, 8,
242 			DWC3_TRBCTL_CONTROL_SETUP);
243 	WARN_ON(ret < 0);
244 }
245 
246 static struct dwc3_ep *dwc3_wIndex_to_dep(struct dwc3 *dwc, __le16 wIndex_le)
247 {
248 	struct dwc3_ep		*dep;
249 	u32			windex = le16_to_cpu(wIndex_le);
250 	u32			epnum;
251 
252 	epnum = (windex & USB_ENDPOINT_NUMBER_MASK) << 1;
253 	if ((windex & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
254 		epnum |= 1;
255 
256 	dep = dwc->eps[epnum];
257 	if (dep->flags & DWC3_EP_ENABLED)
258 		return dep;
259 
260 	return NULL;
261 }
262 
263 static void dwc3_ep0_status_cmpl(struct usb_ep *ep, struct usb_request *req)
264 {
265 }
266 /*
267  * ch 9.4.5
268  */
269 static int dwc3_ep0_handle_status(struct dwc3 *dwc,
270 		struct usb_ctrlrequest *ctrl)
271 {
272 	struct dwc3_ep		*dep;
273 	u32			recip;
274 	u16			usb_status = 0;
275 	__le16			*response_pkt;
276 
277 	recip = ctrl->bRequestType & USB_RECIP_MASK;
278 	switch (recip) {
279 	case USB_RECIP_DEVICE:
280 		/*
281 		 * We are self-powered. U1/U2/LTM will be set later
282 		 * once we handle this states. RemoteWakeup is 0 on SS
283 		 */
284 		usb_status |= dwc->is_selfpowered << USB_DEVICE_SELF_POWERED;
285 		break;
286 
287 	case USB_RECIP_INTERFACE:
288 		/*
289 		 * Function Remote Wake Capable	D0
290 		 * Function Remote Wakeup	D1
291 		 */
292 		break;
293 
294 	case USB_RECIP_ENDPOINT:
295 		dep = dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
296 		if (!dep)
297 			return -EINVAL;
298 
299 		if (dep->flags & DWC3_EP_STALL)
300 			usb_status = 1 << USB_ENDPOINT_HALT;
301 		break;
302 	default:
303 		return -EINVAL;
304 	};
305 
306 	response_pkt = (__le16 *) dwc->setup_buf;
307 	*response_pkt = cpu_to_le16(usb_status);
308 
309 	dep = dwc->eps[0];
310 	dwc->ep0_usb_req.dep = dep;
311 	dwc->ep0_usb_req.request.length = sizeof(*response_pkt);
312 	dwc->ep0_usb_req.request.dma = dwc->setup_buf_addr;
313 	dwc->ep0_usb_req.request.complete = dwc3_ep0_status_cmpl;
314 
315 	return __dwc3_gadget_ep0_queue(dep, &dwc->ep0_usb_req);
316 }
317 
318 static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
319 		struct usb_ctrlrequest *ctrl, int set)
320 {
321 	struct dwc3_ep		*dep;
322 	u32			recip;
323 	u32			wValue;
324 	u32			wIndex;
325 	u32			reg;
326 	int			ret;
327 	u32			mode;
328 
329 	wValue = le16_to_cpu(ctrl->wValue);
330 	wIndex = le16_to_cpu(ctrl->wIndex);
331 	recip = ctrl->bRequestType & USB_RECIP_MASK;
332 	switch (recip) {
333 	case USB_RECIP_DEVICE:
334 
335 		/*
336 		 * 9.4.1 says only only for SS, in AddressState only for
337 		 * default control pipe
338 		 */
339 		switch (wValue) {
340 		case USB_DEVICE_U1_ENABLE:
341 		case USB_DEVICE_U2_ENABLE:
342 		case USB_DEVICE_LTM_ENABLE:
343 			if (dwc->dev_state != DWC3_CONFIGURED_STATE)
344 				return -EINVAL;
345 			if (dwc->speed != DWC3_DSTS_SUPERSPEED)
346 				return -EINVAL;
347 		}
348 
349 		/* XXX add U[12] & LTM */
350 		switch (wValue) {
351 		case USB_DEVICE_REMOTE_WAKEUP:
352 			break;
353 		case USB_DEVICE_U1_ENABLE:
354 			break;
355 		case USB_DEVICE_U2_ENABLE:
356 			break;
357 		case USB_DEVICE_LTM_ENABLE:
358 			break;
359 
360 		case USB_DEVICE_TEST_MODE:
361 			if ((wIndex & 0xff) != 0)
362 				return -EINVAL;
363 			if (!set)
364 				return -EINVAL;
365 
366 			mode = wIndex >> 8;
367 			reg = dwc3_readl(dwc->regs, DWC3_DCTL);
368 			reg &= ~DWC3_DCTL_TSTCTRL_MASK;
369 
370 			switch (mode) {
371 			case TEST_J:
372 			case TEST_K:
373 			case TEST_SE0_NAK:
374 			case TEST_PACKET:
375 			case TEST_FORCE_EN:
376 				reg |= mode << 1;
377 				break;
378 			default:
379 				return -EINVAL;
380 			}
381 			dwc3_writel(dwc->regs, DWC3_DCTL, reg);
382 			break;
383 		default:
384 			return -EINVAL;
385 		}
386 		break;
387 
388 	case USB_RECIP_INTERFACE:
389 		switch (wValue) {
390 		case USB_INTRF_FUNC_SUSPEND:
391 			if (wIndex & USB_INTRF_FUNC_SUSPEND_LP)
392 				/* XXX enable Low power suspend */
393 				;
394 			if (wIndex & USB_INTRF_FUNC_SUSPEND_RW)
395 				/* XXX enable remote wakeup */
396 				;
397 			break;
398 		default:
399 			return -EINVAL;
400 		}
401 		break;
402 
403 	case USB_RECIP_ENDPOINT:
404 		switch (wValue) {
405 		case USB_ENDPOINT_HALT:
406 			dep =  dwc3_wIndex_to_dep(dwc, wIndex);
407 			if (!dep)
408 				return -EINVAL;
409 			ret = __dwc3_gadget_ep_set_halt(dep, set);
410 			if (ret)
411 				return -EINVAL;
412 			break;
413 		default:
414 			return -EINVAL;
415 		}
416 		break;
417 
418 	default:
419 		return -EINVAL;
420 	};
421 
422 	return 0;
423 }
424 
425 static int dwc3_ep0_set_address(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
426 {
427 	u32 addr;
428 	u32 reg;
429 
430 	addr = le16_to_cpu(ctrl->wValue);
431 	if (addr > 127) {
432 		dev_dbg(dwc->dev, "invalid device address %d\n", addr);
433 		return -EINVAL;
434 	}
435 
436 	if (dwc->dev_state == DWC3_CONFIGURED_STATE) {
437 		dev_dbg(dwc->dev, "trying to set address when configured\n");
438 		return -EINVAL;
439 	}
440 
441 	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
442 	reg &= ~(DWC3_DCFG_DEVADDR_MASK);
443 	reg |= DWC3_DCFG_DEVADDR(addr);
444 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
445 
446 	if (addr)
447 		dwc->dev_state = DWC3_ADDRESS_STATE;
448 	else
449 		dwc->dev_state = DWC3_DEFAULT_STATE;
450 
451 	return 0;
452 }
453 
454 static int dwc3_ep0_delegate_req(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
455 {
456 	int ret;
457 
458 	spin_unlock(&dwc->lock);
459 	ret = dwc->gadget_driver->setup(&dwc->gadget, ctrl);
460 	spin_lock(&dwc->lock);
461 	return ret;
462 }
463 
464 static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
465 {
466 	u32 cfg;
467 	int ret;
468 
469 	dwc->start_config_issued = false;
470 	cfg = le16_to_cpu(ctrl->wValue);
471 
472 	switch (dwc->dev_state) {
473 	case DWC3_DEFAULT_STATE:
474 		return -EINVAL;
475 		break;
476 
477 	case DWC3_ADDRESS_STATE:
478 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
479 		/* if the cfg matches and the cfg is non zero */
480 		if (!ret && cfg)
481 			dwc->dev_state = DWC3_CONFIGURED_STATE;
482 		break;
483 
484 	case DWC3_CONFIGURED_STATE:
485 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
486 		if (!cfg)
487 			dwc->dev_state = DWC3_ADDRESS_STATE;
488 		break;
489 	default:
490 		ret = -EINVAL;
491 	}
492 	return ret;
493 }
494 
495 static int dwc3_ep0_std_request(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
496 {
497 	int ret;
498 
499 	switch (ctrl->bRequest) {
500 	case USB_REQ_GET_STATUS:
501 		dev_vdbg(dwc->dev, "USB_REQ_GET_STATUS\n");
502 		ret = dwc3_ep0_handle_status(dwc, ctrl);
503 		break;
504 	case USB_REQ_CLEAR_FEATURE:
505 		dev_vdbg(dwc->dev, "USB_REQ_CLEAR_FEATURE\n");
506 		ret = dwc3_ep0_handle_feature(dwc, ctrl, 0);
507 		break;
508 	case USB_REQ_SET_FEATURE:
509 		dev_vdbg(dwc->dev, "USB_REQ_SET_FEATURE\n");
510 		ret = dwc3_ep0_handle_feature(dwc, ctrl, 1);
511 		break;
512 	case USB_REQ_SET_ADDRESS:
513 		dev_vdbg(dwc->dev, "USB_REQ_SET_ADDRESS\n");
514 		ret = dwc3_ep0_set_address(dwc, ctrl);
515 		break;
516 	case USB_REQ_SET_CONFIGURATION:
517 		dev_vdbg(dwc->dev, "USB_REQ_SET_CONFIGURATION\n");
518 		ret = dwc3_ep0_set_config(dwc, ctrl);
519 		break;
520 	default:
521 		dev_vdbg(dwc->dev, "Forwarding to gadget driver\n");
522 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
523 		break;
524 	};
525 
526 	return ret;
527 }
528 
529 static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
530 		const struct dwc3_event_depevt *event)
531 {
532 	struct usb_ctrlrequest *ctrl = dwc->ctrl_req;
533 	int ret;
534 	u32 len;
535 
536 	if (!dwc->gadget_driver)
537 		goto err;
538 
539 	len = le16_to_cpu(ctrl->wLength);
540 	if (!len) {
541 		dwc->three_stage_setup = false;
542 		dwc->ep0_expect_in = false;
543 		dwc->ep0_next_event = DWC3_EP0_NRDY_STATUS;
544 	} else {
545 		dwc->three_stage_setup = true;
546 		dwc->ep0_expect_in = !!(ctrl->bRequestType & USB_DIR_IN);
547 		dwc->ep0_next_event = DWC3_EP0_NRDY_DATA;
548 	}
549 
550 	if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
551 		ret = dwc3_ep0_std_request(dwc, ctrl);
552 	else
553 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
554 
555 	if (ret == USB_GADGET_DELAYED_STATUS)
556 		dwc->delayed_status = true;
557 
558 	if (ret >= 0)
559 		return;
560 
561 err:
562 	dwc3_ep0_stall_and_restart(dwc);
563 }
564 
565 static void dwc3_ep0_complete_data(struct dwc3 *dwc,
566 		const struct dwc3_event_depevt *event)
567 {
568 	struct dwc3_request	*r = NULL;
569 	struct usb_request	*ur;
570 	struct dwc3_trb		trb;
571 	struct dwc3_ep		*ep0;
572 	u32			transferred;
573 	u8			epnum;
574 
575 	epnum = event->endpoint_number;
576 	ep0 = dwc->eps[0];
577 
578 	dwc->ep0_next_event = DWC3_EP0_NRDY_STATUS;
579 
580 	r = next_request(&ep0->request_list);
581 	ur = &r->request;
582 
583 	dwc3_trb_to_nat(dwc->ep0_trb, &trb);
584 
585 	if (dwc->ep0_bounced) {
586 
587 		transferred = min_t(u32, ur->length,
588 				ep0->endpoint.maxpacket - trb.length);
589 		memcpy(ur->buf, dwc->ep0_bounce, transferred);
590 		dwc->ep0_bounced = false;
591 	} else {
592 		transferred = ur->length - trb.length;
593 		ur->actual += transferred;
594 	}
595 
596 	if ((epnum & 1) && ur->actual < ur->length) {
597 		/* for some reason we did not get everything out */
598 
599 		dwc3_ep0_stall_and_restart(dwc);
600 	} else {
601 		/*
602 		 * handle the case where we have to send a zero packet. This
603 		 * seems to be case when req.length > maxpacket. Could it be?
604 		 */
605 		if (r)
606 			dwc3_gadget_giveback(ep0, r, 0);
607 	}
608 }
609 
610 static void dwc3_ep0_complete_req(struct dwc3 *dwc,
611 		const struct dwc3_event_depevt *event)
612 {
613 	struct dwc3_request	*r;
614 	struct dwc3_ep		*dep;
615 
616 	dep = dwc->eps[0];
617 
618 	if (!list_empty(&dep->request_list)) {
619 		r = next_request(&dep->request_list);
620 
621 		dwc3_gadget_giveback(dep, r, 0);
622 	}
623 
624 	dwc->ep0state = EP0_SETUP_PHASE;
625 	dwc3_ep0_out_start(dwc);
626 }
627 
628 static void dwc3_ep0_xfer_complete(struct dwc3 *dwc,
629 			const struct dwc3_event_depevt *event)
630 {
631 	struct dwc3_ep		*dep = dwc->eps[event->endpoint_number];
632 
633 	dep->flags &= ~DWC3_EP_BUSY;
634 	dwc->setup_packet_pending = false;
635 
636 	switch (dwc->ep0state) {
637 	case EP0_SETUP_PHASE:
638 		dev_vdbg(dwc->dev, "Inspecting Setup Bytes\n");
639 		dwc3_ep0_inspect_setup(dwc, event);
640 		break;
641 
642 	case EP0_DATA_PHASE:
643 		dev_vdbg(dwc->dev, "Data Phase\n");
644 		dwc3_ep0_complete_data(dwc, event);
645 		break;
646 
647 	case EP0_STATUS_PHASE:
648 		dev_vdbg(dwc->dev, "Status Phase\n");
649 		dwc3_ep0_complete_req(dwc, event);
650 		break;
651 	default:
652 		WARN(true, "UNKNOWN ep0state %d\n", dwc->ep0state);
653 	}
654 }
655 
656 static void dwc3_ep0_do_control_setup(struct dwc3 *dwc,
657 		const struct dwc3_event_depevt *event)
658 {
659 	dwc3_ep0_out_start(dwc);
660 }
661 
662 static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
663 		const struct dwc3_event_depevt *event)
664 {
665 	struct dwc3_ep		*dep;
666 	struct dwc3_request	*req;
667 	int			ret;
668 
669 	dep = dwc->eps[0];
670 
671 	if (list_empty(&dep->request_list)) {
672 		dev_vdbg(dwc->dev, "pending request for EP0 Data phase\n");
673 		dep->flags |= DWC3_EP_PENDING_REQUEST;
674 
675 		if (event->endpoint_number)
676 			dep->flags |= DWC3_EP0_DIR_IN;
677 		return;
678 	}
679 
680 	req = next_request(&dep->request_list);
681 	req->direction = !!event->endpoint_number;
682 
683 	if (req->request.length == 0) {
684 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
685 				dwc->ctrl_req_addr, 0,
686 				DWC3_TRBCTL_CONTROL_DATA);
687 	} else if ((req->request.length % dep->endpoint.maxpacket)
688 			&& (event->endpoint_number == 0)) {
689 		dwc3_map_buffer_to_dma(req);
690 
691 		WARN_ON(req->request.length > dep->endpoint.maxpacket);
692 
693 		dwc->ep0_bounced = true;
694 
695 		/*
696 		 * REVISIT in case request length is bigger than EP0
697 		 * wMaxPacketSize, we will need two chained TRBs to handle
698 		 * the transfer.
699 		 */
700 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
701 				dwc->ep0_bounce_addr, dep->endpoint.maxpacket,
702 				DWC3_TRBCTL_CONTROL_DATA);
703 	} else {
704 		dwc3_map_buffer_to_dma(req);
705 
706 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
707 				req->request.dma, req->request.length,
708 				DWC3_TRBCTL_CONTROL_DATA);
709 	}
710 
711 	WARN_ON(ret < 0);
712 }
713 
714 static int dwc3_ep0_start_control_status(struct dwc3_ep *dep)
715 {
716 	struct dwc3		*dwc = dep->dwc;
717 	u32			type;
718 
719 	type = dwc->three_stage_setup ? DWC3_TRBCTL_CONTROL_STATUS3
720 		: DWC3_TRBCTL_CONTROL_STATUS2;
721 
722 	return dwc3_ep0_start_trans(dwc, dep->number,
723 			dwc->ctrl_req_addr, 0, type);
724 }
725 
726 static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum)
727 {
728 	struct dwc3_ep		*dep = dwc->eps[epnum];
729 
730 	WARN_ON(dwc3_ep0_start_control_status(dep));
731 }
732 
733 static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
734 		const struct dwc3_event_depevt *event)
735 {
736 	dwc->setup_packet_pending = true;
737 
738 	/*
739 	 * This part is very tricky: If we has just handled
740 	 * XferNotReady(Setup) and we're now expecting a
741 	 * XferComplete but, instead, we receive another
742 	 * XferNotReady(Setup), we should STALL and restart
743 	 * the state machine.
744 	 *
745 	 * In all other cases, we just continue waiting
746 	 * for the XferComplete event.
747 	 *
748 	 * We are a little bit unsafe here because we're
749 	 * not trying to ensure that last event was, indeed,
750 	 * XferNotReady(Setup).
751 	 *
752 	 * Still, we don't expect any condition where that
753 	 * should happen and, even if it does, it would be
754 	 * another error condition.
755 	 */
756 	if (dwc->ep0_next_event == DWC3_EP0_COMPLETE) {
757 		switch (event->status) {
758 		case DEPEVT_STATUS_CONTROL_SETUP:
759 			dev_vdbg(dwc->dev, "Unexpected XferNotReady(Setup)\n");
760 			dwc3_ep0_stall_and_restart(dwc);
761 			break;
762 		case DEPEVT_STATUS_CONTROL_DATA:
763 			/* FALLTHROUGH */
764 		case DEPEVT_STATUS_CONTROL_STATUS:
765 			/* FALLTHROUGH */
766 		default:
767 			dev_vdbg(dwc->dev, "waiting for XferComplete\n");
768 		}
769 
770 		return;
771 	}
772 
773 	switch (event->status) {
774 	case DEPEVT_STATUS_CONTROL_SETUP:
775 		dev_vdbg(dwc->dev, "Control Setup\n");
776 
777 		dwc->ep0state = EP0_SETUP_PHASE;
778 
779 		dwc3_ep0_do_control_setup(dwc, event);
780 		break;
781 
782 	case DEPEVT_STATUS_CONTROL_DATA:
783 		dev_vdbg(dwc->dev, "Control Data\n");
784 
785 		dwc->ep0state = EP0_DATA_PHASE;
786 
787 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_DATA) {
788 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
789 					dwc->ep0_next_event,
790 					DWC3_EP0_NRDY_DATA);
791 
792 			dwc3_ep0_stall_and_restart(dwc);
793 			return;
794 		}
795 
796 		/*
797 		 * One of the possible error cases is when Host _does_
798 		 * request for Data Phase, but it does so on the wrong
799 		 * direction.
800 		 *
801 		 * Here, we already know ep0_next_event is DATA (see above),
802 		 * so we only need to check for direction.
803 		 */
804 		if (dwc->ep0_expect_in != event->endpoint_number) {
805 			dev_vdbg(dwc->dev, "Wrong direction for Data phase\n");
806 			dwc3_ep0_stall_and_restart(dwc);
807 			return;
808 		}
809 
810 		dwc3_ep0_do_control_data(dwc, event);
811 		break;
812 
813 	case DEPEVT_STATUS_CONTROL_STATUS:
814 		dev_vdbg(dwc->dev, "Control Status\n");
815 
816 		dwc->ep0state = EP0_STATUS_PHASE;
817 
818 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_STATUS) {
819 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
820 					dwc->ep0_next_event,
821 					DWC3_EP0_NRDY_STATUS);
822 
823 			dwc3_ep0_stall_and_restart(dwc);
824 			return;
825 		}
826 
827 		if (dwc->delayed_status) {
828 			WARN_ON_ONCE(event->endpoint_number != 1);
829 			dev_vdbg(dwc->dev, "Mass Storage delayed status\n");
830 			return;
831 		}
832 
833 		dwc3_ep0_do_control_status(dwc, event->endpoint_number);
834 	}
835 }
836 
837 void dwc3_ep0_interrupt(struct dwc3 *dwc,
838 		const struct dwc3_event_depevt *event)
839 {
840 	u8			epnum = event->endpoint_number;
841 
842 	dev_dbg(dwc->dev, "%s while ep%d%s in state '%s'\n",
843 			dwc3_ep_event_string(event->endpoint_event),
844 			epnum >> 1, (epnum & 1) ? "in" : "out",
845 			dwc3_ep0_state_string(dwc->ep0state));
846 
847 	switch (event->endpoint_event) {
848 	case DWC3_DEPEVT_XFERCOMPLETE:
849 		dwc3_ep0_xfer_complete(dwc, event);
850 		break;
851 
852 	case DWC3_DEPEVT_XFERNOTREADY:
853 		dwc3_ep0_xfernotready(dwc, event);
854 		break;
855 
856 	case DWC3_DEPEVT_XFERINPROGRESS:
857 	case DWC3_DEPEVT_RXTXFIFOEVT:
858 	case DWC3_DEPEVT_STREAMEVT:
859 	case DWC3_DEPEVT_EPCMDCMPLT:
860 		break;
861 	}
862 }
863