xref: /linux/drivers/usb/dwc3/ep0.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
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 
52 #include "core.h"
53 #include "gadget.h"
54 #include "io.h"
55 
56 static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
57 		const struct dwc3_event_depevt *event);
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 	int			ret = 0;
129 
130 	req->request.actual	= 0;
131 	req->request.status	= -EINPROGRESS;
132 	req->epnum		= dep->number;
133 
134 	list_add_tail(&req->list, &dep->request_list);
135 
136 	/*
137 	 * Gadget driver might not be quick enough to queue a request
138 	 * before we get a Transfer Not Ready event on this endpoint.
139 	 *
140 	 * In that case, we will set DWC3_EP_PENDING_REQUEST. When that
141 	 * flag is set, it's telling us that as soon as Gadget queues the
142 	 * required request, we should kick the transfer here because the
143 	 * IRQ we were waiting for is long gone.
144 	 */
145 	if (dep->flags & DWC3_EP_PENDING_REQUEST) {
146 		struct dwc3	*dwc = dep->dwc;
147 		unsigned	direction;
148 		u32		type;
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 	}
169 
170 	return ret;
171 }
172 
173 int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request,
174 		gfp_t gfp_flags)
175 {
176 	struct dwc3_request		*req = to_dwc3_request(request);
177 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
178 	struct dwc3			*dwc = dep->dwc;
179 
180 	unsigned long			flags;
181 
182 	int				ret;
183 
184 	spin_lock_irqsave(&dwc->lock, flags);
185 	if (!dep->desc) {
186 		dev_dbg(dwc->dev, "trying to queue request %p to disabled %s\n",
187 				request, dep->name);
188 		ret = -ESHUTDOWN;
189 		goto out;
190 	}
191 
192 	/* we share one TRB for ep0/1 */
193 	if (!list_empty(&dwc->eps[0]->request_list) ||
194 			!list_empty(&dwc->eps[1]->request_list) ||
195 			dwc->ep0_status_pending) {
196 		ret = -EBUSY;
197 		goto out;
198 	}
199 
200 	dev_vdbg(dwc->dev, "queueing request %p to %s length %d, state '%s'\n",
201 			request, dep->name, request->length,
202 			dwc3_ep0_state_string(dwc->ep0state));
203 
204 	ret = __dwc3_gadget_ep0_queue(dep, req);
205 
206 out:
207 	spin_unlock_irqrestore(&dwc->lock, flags);
208 
209 	return ret;
210 }
211 
212 static void dwc3_ep0_stall_and_restart(struct dwc3 *dwc)
213 {
214 	struct dwc3_ep		*dep = dwc->eps[0];
215 
216 	/* stall is always issued on EP0 */
217 	__dwc3_gadget_ep_set_halt(dwc->eps[0], 1);
218 	dwc->eps[0]->flags = DWC3_EP_ENABLED;
219 
220 	if (!list_empty(&dep->request_list)) {
221 		struct dwc3_request	*req;
222 
223 		req = next_request(&dep->request_list);
224 		dwc3_gadget_giveback(dep, req, -ECONNRESET);
225 	}
226 
227 	dwc->ep0state = EP0_SETUP_PHASE;
228 	dwc3_ep0_out_start(dwc);
229 }
230 
231 void dwc3_ep0_out_start(struct dwc3 *dwc)
232 {
233 	int				ret;
234 
235 	ret = dwc3_ep0_start_trans(dwc, 0, dwc->ctrl_req_addr, 8,
236 			DWC3_TRBCTL_CONTROL_SETUP);
237 	WARN_ON(ret < 0);
238 }
239 
240 static struct dwc3_ep *dwc3_wIndex_to_dep(struct dwc3 *dwc, __le16 wIndex_le)
241 {
242 	struct dwc3_ep		*dep;
243 	u32			windex = le16_to_cpu(wIndex_le);
244 	u32			epnum;
245 
246 	epnum = (windex & USB_ENDPOINT_NUMBER_MASK) << 1;
247 	if ((windex & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
248 		epnum |= 1;
249 
250 	dep = dwc->eps[epnum];
251 	if (dep->flags & DWC3_EP_ENABLED)
252 		return dep;
253 
254 	return NULL;
255 }
256 
257 static void dwc3_ep0_send_status_response(struct dwc3 *dwc)
258 {
259 	dwc3_ep0_start_trans(dwc, 1, dwc->setup_buf_addr,
260 			dwc->ep0_usb_req.length,
261 			DWC3_TRBCTL_CONTROL_DATA);
262 }
263 
264 /*
265  * ch 9.4.5
266  */
267 static int dwc3_ep0_handle_status(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
268 {
269 	struct dwc3_ep		*dep;
270 	u32			recip;
271 	u16			usb_status = 0;
272 	__le16			*response_pkt;
273 
274 	recip = ctrl->bRequestType & USB_RECIP_MASK;
275 	switch (recip) {
276 	case USB_RECIP_DEVICE:
277 		/*
278 		 * We are self-powered. U1/U2/LTM will be set later
279 		 * once we handle this states. RemoteWakeup is 0 on SS
280 		 */
281 		usb_status |= dwc->is_selfpowered << USB_DEVICE_SELF_POWERED;
282 		break;
283 
284 	case USB_RECIP_INTERFACE:
285 		/*
286 		 * Function Remote Wake Capable	D0
287 		 * Function Remote Wakeup	D1
288 		 */
289 		break;
290 
291 	case USB_RECIP_ENDPOINT:
292 		dep = dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
293 		if (!dep)
294 		       return -EINVAL;
295 
296 		if (dep->flags & DWC3_EP_STALL)
297 			usb_status = 1 << USB_ENDPOINT_HALT;
298 		break;
299 	default:
300 		return -EINVAL;
301 	};
302 
303 	response_pkt = (__le16 *) dwc->setup_buf;
304 	*response_pkt = cpu_to_le16(usb_status);
305 	dwc->ep0_usb_req.length = sizeof(*response_pkt);
306 	dwc->ep0_status_pending = 1;
307 
308 	return 0;
309 }
310 
311 static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
312 		struct usb_ctrlrequest *ctrl, int set)
313 {
314 	struct dwc3_ep		*dep;
315 	u32			recip;
316 	u32			wValue;
317 	u32			wIndex;
318 	u32			reg;
319 	int			ret;
320 	u32			mode;
321 
322 	wValue = le16_to_cpu(ctrl->wValue);
323 	wIndex = le16_to_cpu(ctrl->wIndex);
324 	recip = ctrl->bRequestType & USB_RECIP_MASK;
325 	switch (recip) {
326 	case USB_RECIP_DEVICE:
327 
328 		/*
329 		 * 9.4.1 says only only for SS, in AddressState only for
330 		 * default control pipe
331 		 */
332 		switch (wValue) {
333 		case USB_DEVICE_U1_ENABLE:
334 		case USB_DEVICE_U2_ENABLE:
335 		case USB_DEVICE_LTM_ENABLE:
336 			if (dwc->dev_state != DWC3_CONFIGURED_STATE)
337 				return -EINVAL;
338 			if (dwc->speed != DWC3_DSTS_SUPERSPEED)
339 				return -EINVAL;
340 		}
341 
342 		/* XXX add U[12] & LTM */
343 		switch (wValue) {
344 		case USB_DEVICE_REMOTE_WAKEUP:
345 			break;
346 		case USB_DEVICE_U1_ENABLE:
347 			break;
348 		case USB_DEVICE_U2_ENABLE:
349 			break;
350 		case USB_DEVICE_LTM_ENABLE:
351 			break;
352 
353 		case USB_DEVICE_TEST_MODE:
354 			if ((wIndex & 0xff) != 0)
355 				return -EINVAL;
356 			if (!set)
357 				return -EINVAL;
358 
359 			mode = wIndex >> 8;
360 			reg = dwc3_readl(dwc->regs, DWC3_DCTL);
361 			reg &= ~DWC3_DCTL_TSTCTRL_MASK;
362 
363 			switch (mode) {
364 			case TEST_J:
365 			case TEST_K:
366 			case TEST_SE0_NAK:
367 			case TEST_PACKET:
368 			case TEST_FORCE_EN:
369 				reg |= mode << 1;
370 				break;
371 			default:
372 				return -EINVAL;
373 			}
374 			dwc3_writel(dwc->regs, DWC3_DCTL, reg);
375 			break;
376 		default:
377 			return -EINVAL;
378 		}
379 		break;
380 
381 	case USB_RECIP_INTERFACE:
382 		switch (wValue) {
383 		case USB_INTRF_FUNC_SUSPEND:
384 			if (wIndex & USB_INTRF_FUNC_SUSPEND_LP)
385 				/* XXX enable Low power suspend */
386 				;
387 			if (wIndex & USB_INTRF_FUNC_SUSPEND_RW)
388 				/* XXX enable remote wakeup */
389 				;
390 			break;
391 		default:
392 			return -EINVAL;
393 		}
394 		break;
395 
396 	case USB_RECIP_ENDPOINT:
397 		switch (wValue) {
398 		case USB_ENDPOINT_HALT:
399 
400 			dep =  dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
401 			if (!dep)
402 				return -EINVAL;
403 			ret = __dwc3_gadget_ep_set_halt(dep, set);
404 			if (ret)
405 				return -EINVAL;
406 			break;
407 		default:
408 			return -EINVAL;
409 		}
410 		break;
411 
412 	default:
413 		return -EINVAL;
414 	};
415 
416 	return 0;
417 }
418 
419 static int dwc3_ep0_set_address(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
420 {
421 	u32 addr;
422 	u32 reg;
423 
424 	addr = le16_to_cpu(ctrl->wValue);
425 	if (addr > 127)
426 		return -EINVAL;
427 
428 	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
429 	reg &= ~(DWC3_DCFG_DEVADDR_MASK);
430 	reg |= DWC3_DCFG_DEVADDR(addr);
431 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
432 
433 	if (addr)
434 		dwc->dev_state = DWC3_ADDRESS_STATE;
435 	else
436 		dwc->dev_state = DWC3_DEFAULT_STATE;
437 
438 	return 0;
439 }
440 
441 static int dwc3_ep0_delegate_req(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
442 {
443 	int ret;
444 
445 	spin_unlock(&dwc->lock);
446 	ret = dwc->gadget_driver->setup(&dwc->gadget, ctrl);
447 	spin_lock(&dwc->lock);
448 	return ret;
449 }
450 
451 static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
452 {
453 	u32 cfg;
454 	int ret;
455 
456 	dwc->start_config_issued = false;
457 	cfg = le16_to_cpu(ctrl->wValue);
458 
459 	switch (dwc->dev_state) {
460 	case DWC3_DEFAULT_STATE:
461 		return -EINVAL;
462 		break;
463 
464 	case DWC3_ADDRESS_STATE:
465 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
466 		/* if the cfg matches and the cfg is non zero */
467 		if (!ret && cfg)
468 			dwc->dev_state = DWC3_CONFIGURED_STATE;
469 		break;
470 
471 	case DWC3_CONFIGURED_STATE:
472 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
473 		if (!cfg)
474 			dwc->dev_state = DWC3_ADDRESS_STATE;
475 		break;
476 	}
477 	return 0;
478 }
479 
480 static int dwc3_ep0_std_request(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
481 {
482 	int ret;
483 
484 	switch (ctrl->bRequest) {
485 	case USB_REQ_GET_STATUS:
486 		dev_vdbg(dwc->dev, "USB_REQ_GET_STATUS\n");
487 		ret = dwc3_ep0_handle_status(dwc, ctrl);
488 		break;
489 	case USB_REQ_CLEAR_FEATURE:
490 		dev_vdbg(dwc->dev, "USB_REQ_CLEAR_FEATURE\n");
491 		ret = dwc3_ep0_handle_feature(dwc, ctrl, 0);
492 		break;
493 	case USB_REQ_SET_FEATURE:
494 		dev_vdbg(dwc->dev, "USB_REQ_SET_FEATURE\n");
495 		ret = dwc3_ep0_handle_feature(dwc, ctrl, 1);
496 		break;
497 	case USB_REQ_SET_ADDRESS:
498 		dev_vdbg(dwc->dev, "USB_REQ_SET_ADDRESS\n");
499 		ret = dwc3_ep0_set_address(dwc, ctrl);
500 		break;
501 	case USB_REQ_SET_CONFIGURATION:
502 		dev_vdbg(dwc->dev, "USB_REQ_SET_CONFIGURATION\n");
503 		ret = dwc3_ep0_set_config(dwc, ctrl);
504 		break;
505 	default:
506 		dev_vdbg(dwc->dev, "Forwarding to gadget driver\n");
507 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
508 		break;
509 	};
510 
511 	return ret;
512 }
513 
514 static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
515 		const struct dwc3_event_depevt *event)
516 {
517 	struct usb_ctrlrequest *ctrl = dwc->ctrl_req;
518 	int ret;
519 	u32 len;
520 
521 	if (!dwc->gadget_driver)
522 		goto err;
523 
524 	len = le16_to_cpu(ctrl->wLength);
525 	if (!len) {
526 		dwc->three_stage_setup = false;
527 		dwc->ep0_expect_in = false;
528 		dwc->ep0_next_event = DWC3_EP0_NRDY_STATUS;
529 	} else {
530 		dwc->three_stage_setup = true;
531 		dwc->ep0_expect_in = !!(ctrl->bRequestType & USB_DIR_IN);
532 		dwc->ep0_next_event = DWC3_EP0_NRDY_DATA;
533 	}
534 
535 	if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
536 		ret = dwc3_ep0_std_request(dwc, ctrl);
537 	else
538 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
539 
540 	if (ret >= 0)
541 		return;
542 
543 err:
544 	dwc3_ep0_stall_and_restart(dwc);
545 }
546 
547 static void dwc3_ep0_complete_data(struct dwc3 *dwc,
548 		const struct dwc3_event_depevt *event)
549 {
550 	struct dwc3_request	*r = NULL;
551 	struct usb_request	*ur;
552 	struct dwc3_trb		trb;
553 	struct dwc3_ep		*dep;
554 	u32			transferred;
555 	u8			epnum;
556 
557 	epnum = event->endpoint_number;
558 	dep = dwc->eps[epnum];
559 
560 	dwc->ep0_next_event = DWC3_EP0_NRDY_STATUS;
561 
562 	if (!dwc->ep0_status_pending) {
563 		r = next_request(&dwc->eps[0]->request_list);
564 		ur = &r->request;
565 	} else {
566 		ur = &dwc->ep0_usb_req;
567 		dwc->ep0_status_pending = 0;
568 	}
569 
570 	dwc3_trb_to_nat(dwc->ep0_trb, &trb);
571 
572 	if (dwc->ep0_bounced) {
573 		struct dwc3_ep	*ep0 = dwc->eps[0];
574 
575 		transferred = min_t(u32, ur->length,
576 				ep0->endpoint.maxpacket - trb.length);
577 		memcpy(ur->buf, dwc->ep0_bounce, transferred);
578 		dwc->ep0_bounced = false;
579 	} else {
580 		transferred = ur->length - trb.length;
581 		ur->actual += transferred;
582 	}
583 
584 	if ((epnum & 1) && ur->actual < ur->length) {
585 		/* for some reason we did not get everything out */
586 
587 		dwc3_ep0_stall_and_restart(dwc);
588 	} else {
589 		/*
590 		 * handle the case where we have to send a zero packet. This
591 		 * seems to be case when req.length > maxpacket. Could it be?
592 		 */
593 		if (r)
594 			dwc3_gadget_giveback(dep, r, 0);
595 	}
596 }
597 
598 static void dwc3_ep0_complete_req(struct dwc3 *dwc,
599 		const struct dwc3_event_depevt *event)
600 {
601 	struct dwc3_request	*r;
602 	struct dwc3_ep		*dep;
603 
604 	dep = dwc->eps[0];
605 
606 	if (!list_empty(&dep->request_list)) {
607 		r = next_request(&dep->request_list);
608 
609 		dwc3_gadget_giveback(dep, r, 0);
610 	}
611 
612 	dwc->ep0state = EP0_SETUP_PHASE;
613 	dwc3_ep0_out_start(dwc);
614 }
615 
616 static void dwc3_ep0_xfer_complete(struct dwc3 *dwc,
617 			const struct dwc3_event_depevt *event)
618 {
619 	struct dwc3_ep		*dep = dwc->eps[event->endpoint_number];
620 
621 	dep->flags &= ~DWC3_EP_BUSY;
622 
623 	switch (dwc->ep0state) {
624 	case EP0_SETUP_PHASE:
625 		dev_vdbg(dwc->dev, "Inspecting Setup Bytes\n");
626 		dwc3_ep0_inspect_setup(dwc, event);
627 		break;
628 
629 	case EP0_DATA_PHASE:
630 		dev_vdbg(dwc->dev, "Data Phase\n");
631 		dwc3_ep0_complete_data(dwc, event);
632 		break;
633 
634 	case EP0_STATUS_PHASE:
635 		dev_vdbg(dwc->dev, "Status Phase\n");
636 		dwc3_ep0_complete_req(dwc, event);
637 		break;
638 	default:
639 		WARN(true, "UNKNOWN ep0state %d\n", dwc->ep0state);
640 	}
641 }
642 
643 static void dwc3_ep0_do_control_setup(struct dwc3 *dwc,
644 		const struct dwc3_event_depevt *event)
645 {
646 	dwc->ep0state = EP0_SETUP_PHASE;
647 	dwc3_ep0_out_start(dwc);
648 }
649 
650 static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
651 		const struct dwc3_event_depevt *event)
652 {
653 	struct dwc3_ep		*dep;
654 	struct dwc3_request	*req;
655 	int			ret;
656 
657 	dep = dwc->eps[0];
658 	dwc->ep0state = EP0_DATA_PHASE;
659 
660 	if (dwc->ep0_status_pending) {
661 		dwc3_ep0_send_status_response(dwc);
662 		return;
663 	}
664 
665 	if (list_empty(&dep->request_list)) {
666 		dev_vdbg(dwc->dev, "pending request for EP0 Data phase\n");
667 		dep->flags |= DWC3_EP_PENDING_REQUEST;
668 
669 		if (event->endpoint_number)
670 			dep->flags |= DWC3_EP0_DIR_IN;
671 		return;
672 	}
673 
674 	req = next_request(&dep->request_list);
675 	req->direction = !!event->endpoint_number;
676 
677 	dwc->ep0state = EP0_DATA_PHASE;
678 	if (req->request.length == 0) {
679 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
680 				dwc->ctrl_req_addr, 0,
681 				DWC3_TRBCTL_CONTROL_DATA);
682 	} else if ((req->request.length % dep->endpoint.maxpacket)
683 			&& (event->endpoint_number == 0)) {
684 		dwc3_map_buffer_to_dma(req);
685 
686 		WARN_ON(req->request.length > dep->endpoint.maxpacket);
687 
688 		dwc->ep0_bounced = true;
689 
690 		/*
691 		 * REVISIT in case request length is bigger than EP0
692 		 * wMaxPacketSize, we will need two chained TRBs to handle
693 		 * the transfer.
694 		 */
695 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
696 				dwc->ep0_bounce_addr, dep->endpoint.maxpacket,
697 				DWC3_TRBCTL_CONTROL_DATA);
698 	} else {
699 		dwc3_map_buffer_to_dma(req);
700 
701 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
702 				req->request.dma, req->request.length,
703 				DWC3_TRBCTL_CONTROL_DATA);
704 	}
705 
706 	WARN_ON(ret < 0);
707 }
708 
709 static void dwc3_ep0_do_control_status(struct dwc3 *dwc,
710 		const struct dwc3_event_depevt *event)
711 {
712 	u32			type;
713 	int			ret;
714 
715 	dwc->ep0state = EP0_STATUS_PHASE;
716 
717 	type = dwc->three_stage_setup ? DWC3_TRBCTL_CONTROL_STATUS3
718 		: DWC3_TRBCTL_CONTROL_STATUS2;
719 
720 	ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
721 			dwc->ctrl_req_addr, 0, type);
722 
723 	WARN_ON(ret < 0);
724 }
725 
726 static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
727 		const struct dwc3_event_depevt *event)
728 {
729 	switch (event->status) {
730 	case DEPEVT_STATUS_CONTROL_SETUP:
731 		dev_vdbg(dwc->dev, "Control Setup\n");
732 		dwc3_ep0_do_control_setup(dwc, event);
733 		break;
734 
735 	case DEPEVT_STATUS_CONTROL_DATA:
736 		dev_vdbg(dwc->dev, "Control Data\n");
737 
738 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_DATA) {
739 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
740 					dwc->ep0_next_event,
741 					DWC3_EP0_NRDY_DATA);
742 
743 			dwc3_ep0_stall_and_restart(dwc);
744 			return;
745 		}
746 
747 		/*
748 		 * One of the possible error cases is when Host _does_
749 		 * request for Data Phase, but it does so on the wrong
750 		 * direction.
751 		 *
752 		 * Here, we already know ep0_next_event is DATA (see above),
753 		 * so we only need to check for direction.
754 		 */
755 		if (dwc->ep0_expect_in != event->endpoint_number) {
756 			dev_vdbg(dwc->dev, "Wrong direction for Data phase\n");
757 			dwc3_ep0_stall_and_restart(dwc);
758 			return;
759 		}
760 
761 		dwc3_ep0_do_control_data(dwc, event);
762 		break;
763 
764 	case DEPEVT_STATUS_CONTROL_STATUS:
765 		dev_vdbg(dwc->dev, "Control Status\n");
766 
767 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_STATUS) {
768 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
769 					dwc->ep0_next_event,
770 					DWC3_EP0_NRDY_STATUS);
771 
772 			dwc3_ep0_stall_and_restart(dwc);
773 			return;
774 		}
775 		dwc3_ep0_do_control_status(dwc, event);
776 	}
777 }
778 
779 void dwc3_ep0_interrupt(struct dwc3 *dwc,
780 		const const struct dwc3_event_depevt *event)
781 {
782 	u8			epnum = event->endpoint_number;
783 
784 	dev_dbg(dwc->dev, "%s while ep%d%s in state '%s'\n",
785 			dwc3_ep_event_string(event->endpoint_event),
786 			epnum >> 1, (epnum & 1) ? "in" : "out",
787 			dwc3_ep0_state_string(dwc->ep0state));
788 
789 	switch (event->endpoint_event) {
790 	case DWC3_DEPEVT_XFERCOMPLETE:
791 		dwc3_ep0_xfer_complete(dwc, event);
792 		break;
793 
794 	case DWC3_DEPEVT_XFERNOTREADY:
795 		dwc3_ep0_xfernotready(dwc, event);
796 		break;
797 
798 	case DWC3_DEPEVT_XFERINPROGRESS:
799 	case DWC3_DEPEVT_RXTXFIFOEVT:
800 	case DWC3_DEPEVT_STREAMEVT:
801 	case DWC3_DEPEVT_EPCMDCMPLT:
802 		break;
803 	}
804 }
805