xref: /openbmc/linux/drivers/usb/dwc3/ep0.c (revision 63dc02bd)
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			*trb;
80 	struct dwc3_ep			*dep;
81 
82 	int				ret;
83 
84 	dep = dwc->eps[epnum];
85 	if (dep->flags & DWC3_EP_BUSY) {
86 		dev_vdbg(dwc->dev, "%s: still busy\n", dep->name);
87 		return 0;
88 	}
89 
90 	trb = dwc->ep0_trb;
91 
92 	trb->bpl = lower_32_bits(buf_dma);
93 	trb->bph = upper_32_bits(buf_dma);
94 	trb->size = len;
95 	trb->ctrl = type;
96 
97 	trb->ctrl |= (DWC3_TRB_CTRL_HWO
98 			| DWC3_TRB_CTRL_LST
99 			| DWC3_TRB_CTRL_IOC
100 			| DWC3_TRB_CTRL_ISP_IMI);
101 
102 	memset(&params, 0, sizeof(params));
103 	params.param0 = upper_32_bits(dwc->ep0_trb_addr);
104 	params.param1 = lower_32_bits(dwc->ep0_trb_addr);
105 
106 	ret = dwc3_send_gadget_ep_cmd(dwc, dep->number,
107 			DWC3_DEPCMD_STARTTRANSFER, &params);
108 	if (ret < 0) {
109 		dev_dbg(dwc->dev, "failed to send STARTTRANSFER command\n");
110 		return ret;
111 	}
112 
113 	dep->flags |= DWC3_EP_BUSY;
114 	dep->res_trans_idx = dwc3_gadget_ep_get_transfer_index(dwc,
115 			dep->number);
116 
117 	dwc->ep0_next_event = DWC3_EP0_COMPLETE;
118 
119 	return 0;
120 }
121 
122 static int __dwc3_gadget_ep0_queue(struct dwc3_ep *dep,
123 		struct dwc3_request *req)
124 {
125 	struct dwc3		*dwc = dep->dwc;
126 	int			ret = 0;
127 
128 	req->request.actual	= 0;
129 	req->request.status	= -EINPROGRESS;
130 	req->epnum		= dep->number;
131 
132 	list_add_tail(&req->list, &dep->request_list);
133 
134 	/*
135 	 * Gadget driver might not be quick enough to queue a request
136 	 * before we get a Transfer Not Ready event on this endpoint.
137 	 *
138 	 * In that case, we will set DWC3_EP_PENDING_REQUEST. When that
139 	 * flag is set, it's telling us that as soon as Gadget queues the
140 	 * required request, we should kick the transfer here because the
141 	 * IRQ we were waiting for is long gone.
142 	 */
143 	if (dep->flags & DWC3_EP_PENDING_REQUEST) {
144 		unsigned	direction;
145 
146 		direction = !!(dep->flags & DWC3_EP0_DIR_IN);
147 
148 		if (dwc->ep0state != EP0_DATA_PHASE) {
149 			dev_WARN(dwc->dev, "Unexpected pending request\n");
150 			return 0;
151 		}
152 
153 		ret = dwc3_ep0_start_trans(dwc, direction,
154 				req->request.dma, req->request.length,
155 				DWC3_TRBCTL_CONTROL_DATA);
156 		dep->flags &= ~(DWC3_EP_PENDING_REQUEST |
157 				DWC3_EP0_DIR_IN);
158 	} else if (dwc->delayed_status) {
159 		dwc->delayed_status = false;
160 
161 		if (dwc->ep0state == EP0_STATUS_PHASE)
162 			dwc3_ep0_do_control_status(dwc, 1);
163 		else
164 			dev_dbg(dwc->dev, "too early for delayed status\n");
165 	}
166 
167 	return ret;
168 }
169 
170 int dwc3_gadget_ep0_queue(struct usb_ep *ep, struct usb_request *request,
171 		gfp_t gfp_flags)
172 {
173 	struct dwc3_request		*req = to_dwc3_request(request);
174 	struct dwc3_ep			*dep = to_dwc3_ep(ep);
175 	struct dwc3			*dwc = dep->dwc;
176 
177 	unsigned long			flags;
178 
179 	int				ret;
180 
181 	spin_lock_irqsave(&dwc->lock, flags);
182 	if (!dep->desc) {
183 		dev_dbg(dwc->dev, "trying to queue request %p to disabled %s\n",
184 				request, dep->name);
185 		ret = -ESHUTDOWN;
186 		goto out;
187 	}
188 
189 	/* we share one TRB for ep0/1 */
190 	if (!list_empty(&dep->request_list)) {
191 		ret = -EBUSY;
192 		goto out;
193 	}
194 
195 	dev_vdbg(dwc->dev, "queueing request %p to %s length %d, state '%s'\n",
196 			request, dep->name, request->length,
197 			dwc3_ep0_state_string(dwc->ep0state));
198 
199 	ret = __dwc3_gadget_ep0_queue(dep, req);
200 
201 out:
202 	spin_unlock_irqrestore(&dwc->lock, flags);
203 
204 	return ret;
205 }
206 
207 static void dwc3_ep0_stall_and_restart(struct dwc3 *dwc)
208 {
209 	struct dwc3_ep		*dep = dwc->eps[0];
210 
211 	/* stall is always issued on EP0 */
212 	__dwc3_gadget_ep_set_halt(dep, 1);
213 	dep->flags = DWC3_EP_ENABLED;
214 	dwc->delayed_status = false;
215 
216 	if (!list_empty(&dep->request_list)) {
217 		struct dwc3_request	*req;
218 
219 		req = next_request(&dep->request_list);
220 		dwc3_gadget_giveback(dep, req, -ECONNRESET);
221 	}
222 
223 	dwc->ep0state = EP0_SETUP_PHASE;
224 	dwc3_ep0_out_start(dwc);
225 }
226 
227 void dwc3_ep0_out_start(struct dwc3 *dwc)
228 {
229 	int				ret;
230 
231 	ret = dwc3_ep0_start_trans(dwc, 0, dwc->ctrl_req_addr, 8,
232 			DWC3_TRBCTL_CONTROL_SETUP);
233 	WARN_ON(ret < 0);
234 }
235 
236 static struct dwc3_ep *dwc3_wIndex_to_dep(struct dwc3 *dwc, __le16 wIndex_le)
237 {
238 	struct dwc3_ep		*dep;
239 	u32			windex = le16_to_cpu(wIndex_le);
240 	u32			epnum;
241 
242 	epnum = (windex & USB_ENDPOINT_NUMBER_MASK) << 1;
243 	if ((windex & USB_ENDPOINT_DIR_MASK) == USB_DIR_IN)
244 		epnum |= 1;
245 
246 	dep = dwc->eps[epnum];
247 	if (dep->flags & DWC3_EP_ENABLED)
248 		return dep;
249 
250 	return NULL;
251 }
252 
253 static void dwc3_ep0_status_cmpl(struct usb_ep *ep, struct usb_request *req)
254 {
255 }
256 /*
257  * ch 9.4.5
258  */
259 static int dwc3_ep0_handle_status(struct dwc3 *dwc,
260 		struct usb_ctrlrequest *ctrl)
261 {
262 	struct dwc3_ep		*dep;
263 	u32			recip;
264 	u16			usb_status = 0;
265 	__le16			*response_pkt;
266 
267 	recip = ctrl->bRequestType & USB_RECIP_MASK;
268 	switch (recip) {
269 	case USB_RECIP_DEVICE:
270 		/*
271 		 * We are self-powered. U1/U2/LTM will be set later
272 		 * once we handle this states. RemoteWakeup is 0 on SS
273 		 */
274 		usb_status |= dwc->is_selfpowered << USB_DEVICE_SELF_POWERED;
275 		break;
276 
277 	case USB_RECIP_INTERFACE:
278 		/*
279 		 * Function Remote Wake Capable	D0
280 		 * Function Remote Wakeup	D1
281 		 */
282 		break;
283 
284 	case USB_RECIP_ENDPOINT:
285 		dep = dwc3_wIndex_to_dep(dwc, ctrl->wIndex);
286 		if (!dep)
287 			return -EINVAL;
288 
289 		if (dep->flags & DWC3_EP_STALL)
290 			usb_status = 1 << USB_ENDPOINT_HALT;
291 		break;
292 	default:
293 		return -EINVAL;
294 	};
295 
296 	response_pkt = (__le16 *) dwc->setup_buf;
297 	*response_pkt = cpu_to_le16(usb_status);
298 
299 	dep = dwc->eps[0];
300 	dwc->ep0_usb_req.dep = dep;
301 	dwc->ep0_usb_req.request.length = sizeof(*response_pkt);
302 	dwc->ep0_usb_req.request.buf = dwc->setup_buf;
303 	dwc->ep0_usb_req.request.complete = dwc3_ep0_status_cmpl;
304 
305 	return __dwc3_gadget_ep0_queue(dep, &dwc->ep0_usb_req);
306 }
307 
308 static int dwc3_ep0_handle_feature(struct dwc3 *dwc,
309 		struct usb_ctrlrequest *ctrl, int set)
310 {
311 	struct dwc3_ep		*dep;
312 	u32			recip;
313 	u32			wValue;
314 	u32			wIndex;
315 	int			ret;
316 
317 	wValue = le16_to_cpu(ctrl->wValue);
318 	wIndex = le16_to_cpu(ctrl->wIndex);
319 	recip = ctrl->bRequestType & USB_RECIP_MASK;
320 	switch (recip) {
321 	case USB_RECIP_DEVICE:
322 
323 		/*
324 		 * 9.4.1 says only only for SS, in AddressState only for
325 		 * default control pipe
326 		 */
327 		switch (wValue) {
328 		case USB_DEVICE_U1_ENABLE:
329 		case USB_DEVICE_U2_ENABLE:
330 		case USB_DEVICE_LTM_ENABLE:
331 			if (dwc->dev_state != DWC3_CONFIGURED_STATE)
332 				return -EINVAL;
333 			if (dwc->speed != DWC3_DSTS_SUPERSPEED)
334 				return -EINVAL;
335 		}
336 
337 		/* XXX add U[12] & LTM */
338 		switch (wValue) {
339 		case USB_DEVICE_REMOTE_WAKEUP:
340 			break;
341 		case USB_DEVICE_U1_ENABLE:
342 			break;
343 		case USB_DEVICE_U2_ENABLE:
344 			break;
345 		case USB_DEVICE_LTM_ENABLE:
346 			break;
347 
348 		case USB_DEVICE_TEST_MODE:
349 			if ((wIndex & 0xff) != 0)
350 				return -EINVAL;
351 			if (!set)
352 				return -EINVAL;
353 
354 			dwc->test_mode_nr = wIndex >> 8;
355 			dwc->test_mode = true;
356 			break;
357 		default:
358 			return -EINVAL;
359 		}
360 		break;
361 
362 	case USB_RECIP_INTERFACE:
363 		switch (wValue) {
364 		case USB_INTRF_FUNC_SUSPEND:
365 			if (wIndex & USB_INTRF_FUNC_SUSPEND_LP)
366 				/* XXX enable Low power suspend */
367 				;
368 			if (wIndex & USB_INTRF_FUNC_SUSPEND_RW)
369 				/* XXX enable remote wakeup */
370 				;
371 			break;
372 		default:
373 			return -EINVAL;
374 		}
375 		break;
376 
377 	case USB_RECIP_ENDPOINT:
378 		switch (wValue) {
379 		case USB_ENDPOINT_HALT:
380 			dep = dwc3_wIndex_to_dep(dwc, wIndex);
381 			if (!dep)
382 				return -EINVAL;
383 			ret = __dwc3_gadget_ep_set_halt(dep, set);
384 			if (ret)
385 				return -EINVAL;
386 			break;
387 		default:
388 			return -EINVAL;
389 		}
390 		break;
391 
392 	default:
393 		return -EINVAL;
394 	};
395 
396 	return 0;
397 }
398 
399 static int dwc3_ep0_set_address(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
400 {
401 	u32 addr;
402 	u32 reg;
403 
404 	addr = le16_to_cpu(ctrl->wValue);
405 	if (addr > 127) {
406 		dev_dbg(dwc->dev, "invalid device address %d\n", addr);
407 		return -EINVAL;
408 	}
409 
410 	if (dwc->dev_state == DWC3_CONFIGURED_STATE) {
411 		dev_dbg(dwc->dev, "trying to set address when configured\n");
412 		return -EINVAL;
413 	}
414 
415 	reg = dwc3_readl(dwc->regs, DWC3_DCFG);
416 	reg &= ~(DWC3_DCFG_DEVADDR_MASK);
417 	reg |= DWC3_DCFG_DEVADDR(addr);
418 	dwc3_writel(dwc->regs, DWC3_DCFG, reg);
419 
420 	if (addr)
421 		dwc->dev_state = DWC3_ADDRESS_STATE;
422 	else
423 		dwc->dev_state = DWC3_DEFAULT_STATE;
424 
425 	return 0;
426 }
427 
428 static int dwc3_ep0_delegate_req(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
429 {
430 	int ret;
431 
432 	spin_unlock(&dwc->lock);
433 	ret = dwc->gadget_driver->setup(&dwc->gadget, ctrl);
434 	spin_lock(&dwc->lock);
435 	return ret;
436 }
437 
438 static int dwc3_ep0_set_config(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
439 {
440 	u32 cfg;
441 	int ret;
442 
443 	dwc->start_config_issued = false;
444 	cfg = le16_to_cpu(ctrl->wValue);
445 
446 	switch (dwc->dev_state) {
447 	case DWC3_DEFAULT_STATE:
448 		return -EINVAL;
449 		break;
450 
451 	case DWC3_ADDRESS_STATE:
452 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
453 		/* if the cfg matches and the cfg is non zero */
454 		if (cfg && (!ret || (ret == USB_GADGET_DELAYED_STATUS))) {
455 			dwc->dev_state = DWC3_CONFIGURED_STATE;
456 			dwc->resize_fifos = true;
457 			dev_dbg(dwc->dev, "resize fifos flag SET\n");
458 		}
459 		break;
460 
461 	case DWC3_CONFIGURED_STATE:
462 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
463 		if (!cfg)
464 			dwc->dev_state = DWC3_ADDRESS_STATE;
465 		break;
466 	default:
467 		ret = -EINVAL;
468 	}
469 	return ret;
470 }
471 
472 static int dwc3_ep0_std_request(struct dwc3 *dwc, struct usb_ctrlrequest *ctrl)
473 {
474 	int ret;
475 
476 	switch (ctrl->bRequest) {
477 	case USB_REQ_GET_STATUS:
478 		dev_vdbg(dwc->dev, "USB_REQ_GET_STATUS\n");
479 		ret = dwc3_ep0_handle_status(dwc, ctrl);
480 		break;
481 	case USB_REQ_CLEAR_FEATURE:
482 		dev_vdbg(dwc->dev, "USB_REQ_CLEAR_FEATURE\n");
483 		ret = dwc3_ep0_handle_feature(dwc, ctrl, 0);
484 		break;
485 	case USB_REQ_SET_FEATURE:
486 		dev_vdbg(dwc->dev, "USB_REQ_SET_FEATURE\n");
487 		ret = dwc3_ep0_handle_feature(dwc, ctrl, 1);
488 		break;
489 	case USB_REQ_SET_ADDRESS:
490 		dev_vdbg(dwc->dev, "USB_REQ_SET_ADDRESS\n");
491 		ret = dwc3_ep0_set_address(dwc, ctrl);
492 		break;
493 	case USB_REQ_SET_CONFIGURATION:
494 		dev_vdbg(dwc->dev, "USB_REQ_SET_CONFIGURATION\n");
495 		ret = dwc3_ep0_set_config(dwc, ctrl);
496 		break;
497 	default:
498 		dev_vdbg(dwc->dev, "Forwarding to gadget driver\n");
499 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
500 		break;
501 	};
502 
503 	return ret;
504 }
505 
506 static void dwc3_ep0_inspect_setup(struct dwc3 *dwc,
507 		const struct dwc3_event_depevt *event)
508 {
509 	struct usb_ctrlrequest *ctrl = dwc->ctrl_req;
510 	int ret;
511 	u32 len;
512 
513 	if (!dwc->gadget_driver)
514 		goto err;
515 
516 	len = le16_to_cpu(ctrl->wLength);
517 	if (!len) {
518 		dwc->three_stage_setup = false;
519 		dwc->ep0_expect_in = false;
520 		dwc->ep0_next_event = DWC3_EP0_NRDY_STATUS;
521 	} else {
522 		dwc->three_stage_setup = true;
523 		dwc->ep0_expect_in = !!(ctrl->bRequestType & USB_DIR_IN);
524 		dwc->ep0_next_event = DWC3_EP0_NRDY_DATA;
525 	}
526 
527 	if ((ctrl->bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
528 		ret = dwc3_ep0_std_request(dwc, ctrl);
529 	else
530 		ret = dwc3_ep0_delegate_req(dwc, ctrl);
531 
532 	if (ret == USB_GADGET_DELAYED_STATUS)
533 		dwc->delayed_status = true;
534 
535 	if (ret >= 0)
536 		return;
537 
538 err:
539 	dwc3_ep0_stall_and_restart(dwc);
540 }
541 
542 static void dwc3_ep0_complete_data(struct dwc3 *dwc,
543 		const struct dwc3_event_depevt *event)
544 {
545 	struct dwc3_request	*r = NULL;
546 	struct usb_request	*ur;
547 	struct dwc3_trb		*trb;
548 	struct dwc3_ep		*ep0;
549 	u32			transferred;
550 	u32			length;
551 	u8			epnum;
552 
553 	epnum = event->endpoint_number;
554 	ep0 = dwc->eps[0];
555 
556 	dwc->ep0_next_event = DWC3_EP0_NRDY_STATUS;
557 
558 	r = next_request(&ep0->request_list);
559 	ur = &r->request;
560 
561 	trb = dwc->ep0_trb;
562 	length = trb->size & DWC3_TRB_SIZE_MASK;
563 
564 	if (dwc->ep0_bounced) {
565 		unsigned transfer_size = ur->length;
566 		unsigned maxp = ep0->endpoint.maxpacket;
567 
568 		transfer_size += (maxp - (transfer_size % maxp));
569 		transferred = min_t(u32, ur->length,
570 				transfer_size - length);
571 		memcpy(ur->buf, dwc->ep0_bounce, transferred);
572 		dwc->ep0_bounced = false;
573 	} else {
574 		transferred = ur->length - length;
575 	}
576 
577 	ur->actual += transferred;
578 
579 	if ((epnum & 1) && ur->actual < ur->length) {
580 		/* for some reason we did not get everything out */
581 
582 		dwc3_ep0_stall_and_restart(dwc);
583 	} else {
584 		/*
585 		 * handle the case where we have to send a zero packet. This
586 		 * seems to be case when req.length > maxpacket. Could it be?
587 		 */
588 		if (r)
589 			dwc3_gadget_giveback(ep0, r, 0);
590 	}
591 }
592 
593 static void dwc3_ep0_complete_req(struct dwc3 *dwc,
594 		const struct dwc3_event_depevt *event)
595 {
596 	struct dwc3_request	*r;
597 	struct dwc3_ep		*dep;
598 
599 	dep = dwc->eps[0];
600 
601 	if (!list_empty(&dep->request_list)) {
602 		r = next_request(&dep->request_list);
603 
604 		dwc3_gadget_giveback(dep, r, 0);
605 	}
606 
607 	if (dwc->test_mode) {
608 		int ret;
609 
610 		ret = dwc3_gadget_set_test_mode(dwc, dwc->test_mode_nr);
611 		if (ret < 0) {
612 			dev_dbg(dwc->dev, "Invalid Test #%d\n",
613 					dwc->test_mode_nr);
614 			dwc3_ep0_stall_and_restart(dwc);
615 		}
616 	}
617 
618 	dwc->ep0state = EP0_SETUP_PHASE;
619 	dwc3_ep0_out_start(dwc);
620 }
621 
622 static void dwc3_ep0_xfer_complete(struct dwc3 *dwc,
623 			const struct dwc3_event_depevt *event)
624 {
625 	struct dwc3_ep		*dep = dwc->eps[event->endpoint_number];
626 
627 	dep->flags &= ~DWC3_EP_BUSY;
628 	dep->res_trans_idx = 0;
629 	dwc->setup_packet_pending = false;
630 
631 	switch (dwc->ep0state) {
632 	case EP0_SETUP_PHASE:
633 		dev_vdbg(dwc->dev, "Inspecting Setup Bytes\n");
634 		dwc3_ep0_inspect_setup(dwc, event);
635 		break;
636 
637 	case EP0_DATA_PHASE:
638 		dev_vdbg(dwc->dev, "Data Phase\n");
639 		dwc3_ep0_complete_data(dwc, event);
640 		break;
641 
642 	case EP0_STATUS_PHASE:
643 		dev_vdbg(dwc->dev, "Status Phase\n");
644 		dwc3_ep0_complete_req(dwc, event);
645 		break;
646 	default:
647 		WARN(true, "UNKNOWN ep0state %d\n", dwc->ep0state);
648 	}
649 }
650 
651 static void dwc3_ep0_do_control_setup(struct dwc3 *dwc,
652 		const struct dwc3_event_depevt *event)
653 {
654 	dwc3_ep0_out_start(dwc);
655 }
656 
657 static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
658 		const struct dwc3_event_depevt *event)
659 {
660 	struct dwc3_ep		*dep;
661 	struct dwc3_request	*req;
662 	int			ret;
663 
664 	dep = dwc->eps[0];
665 
666 	if (list_empty(&dep->request_list)) {
667 		dev_vdbg(dwc->dev, "pending request for EP0 Data phase\n");
668 		dep->flags |= DWC3_EP_PENDING_REQUEST;
669 
670 		if (event->endpoint_number)
671 			dep->flags |= DWC3_EP0_DIR_IN;
672 		return;
673 	}
674 
675 	req = next_request(&dep->request_list);
676 	req->direction = !!event->endpoint_number;
677 
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 		ret = usb_gadget_map_request(&dwc->gadget, &req->request,
685 				event->endpoint_number);
686 		if (ret) {
687 			dev_dbg(dwc->dev, "failed to map request\n");
688 			return;
689 		}
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 		ret = usb_gadget_map_request(&dwc->gadget, &req->request,
705 				event->endpoint_number);
706 		if (ret) {
707 			dev_dbg(dwc->dev, "failed to map request\n");
708 			return;
709 		}
710 
711 		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
712 				req->request.dma, req->request.length,
713 				DWC3_TRBCTL_CONTROL_DATA);
714 	}
715 
716 	WARN_ON(ret < 0);
717 }
718 
719 static int dwc3_ep0_start_control_status(struct dwc3_ep *dep)
720 {
721 	struct dwc3		*dwc = dep->dwc;
722 	u32			type;
723 
724 	type = dwc->three_stage_setup ? DWC3_TRBCTL_CONTROL_STATUS3
725 		: DWC3_TRBCTL_CONTROL_STATUS2;
726 
727 	return dwc3_ep0_start_trans(dwc, dep->number,
728 			dwc->ctrl_req_addr, 0, type);
729 }
730 
731 static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum)
732 {
733 	struct dwc3_ep		*dep = dwc->eps[epnum];
734 
735 	if (dwc->resize_fifos) {
736 		dev_dbg(dwc->dev, "starting to resize fifos\n");
737 		dwc3_gadget_resize_tx_fifos(dwc);
738 		dwc->resize_fifos = 0;
739 	}
740 
741 	WARN_ON(dwc3_ep0_start_control_status(dep));
742 }
743 
744 static void dwc3_ep0_xfernotready(struct dwc3 *dwc,
745 		const struct dwc3_event_depevt *event)
746 {
747 	dwc->setup_packet_pending = true;
748 
749 	/*
750 	 * This part is very tricky: If we has just handled
751 	 * XferNotReady(Setup) and we're now expecting a
752 	 * XferComplete but, instead, we receive another
753 	 * XferNotReady(Setup), we should STALL and restart
754 	 * the state machine.
755 	 *
756 	 * In all other cases, we just continue waiting
757 	 * for the XferComplete event.
758 	 *
759 	 * We are a little bit unsafe here because we're
760 	 * not trying to ensure that last event was, indeed,
761 	 * XferNotReady(Setup).
762 	 *
763 	 * Still, we don't expect any condition where that
764 	 * should happen and, even if it does, it would be
765 	 * another error condition.
766 	 */
767 	if (dwc->ep0_next_event == DWC3_EP0_COMPLETE) {
768 		switch (event->status) {
769 		case DEPEVT_STATUS_CONTROL_SETUP:
770 			dev_vdbg(dwc->dev, "Unexpected XferNotReady(Setup)\n");
771 			dwc3_ep0_stall_and_restart(dwc);
772 			break;
773 		case DEPEVT_STATUS_CONTROL_DATA:
774 			/* FALLTHROUGH */
775 		case DEPEVT_STATUS_CONTROL_STATUS:
776 			/* FALLTHROUGH */
777 		default:
778 			dev_vdbg(dwc->dev, "waiting for XferComplete\n");
779 		}
780 
781 		return;
782 	}
783 
784 	switch (event->status) {
785 	case DEPEVT_STATUS_CONTROL_SETUP:
786 		dev_vdbg(dwc->dev, "Control Setup\n");
787 
788 		dwc->ep0state = EP0_SETUP_PHASE;
789 
790 		dwc3_ep0_do_control_setup(dwc, event);
791 		break;
792 
793 	case DEPEVT_STATUS_CONTROL_DATA:
794 		dev_vdbg(dwc->dev, "Control Data\n");
795 
796 		dwc->ep0state = EP0_DATA_PHASE;
797 
798 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_DATA) {
799 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
800 					dwc->ep0_next_event,
801 					DWC3_EP0_NRDY_DATA);
802 
803 			dwc3_ep0_stall_and_restart(dwc);
804 			return;
805 		}
806 
807 		/*
808 		 * One of the possible error cases is when Host _does_
809 		 * request for Data Phase, but it does so on the wrong
810 		 * direction.
811 		 *
812 		 * Here, we already know ep0_next_event is DATA (see above),
813 		 * so we only need to check for direction.
814 		 */
815 		if (dwc->ep0_expect_in != event->endpoint_number) {
816 			dev_vdbg(dwc->dev, "Wrong direction for Data phase\n");
817 			dwc3_ep0_stall_and_restart(dwc);
818 			return;
819 		}
820 
821 		dwc3_ep0_do_control_data(dwc, event);
822 		break;
823 
824 	case DEPEVT_STATUS_CONTROL_STATUS:
825 		dev_vdbg(dwc->dev, "Control Status\n");
826 
827 		dwc->ep0state = EP0_STATUS_PHASE;
828 
829 		if (dwc->ep0_next_event != DWC3_EP0_NRDY_STATUS) {
830 			dev_vdbg(dwc->dev, "Expected %d got %d\n",
831 					dwc->ep0_next_event,
832 					DWC3_EP0_NRDY_STATUS);
833 
834 			dwc3_ep0_stall_and_restart(dwc);
835 			return;
836 		}
837 
838 		if (dwc->delayed_status) {
839 			WARN_ON_ONCE(event->endpoint_number != 1);
840 			dev_vdbg(dwc->dev, "Mass Storage delayed status\n");
841 			return;
842 		}
843 
844 		dwc3_ep0_do_control_status(dwc, event->endpoint_number);
845 	}
846 }
847 
848 void dwc3_ep0_interrupt(struct dwc3 *dwc,
849 		const struct dwc3_event_depevt *event)
850 {
851 	u8			epnum = event->endpoint_number;
852 
853 	dev_dbg(dwc->dev, "%s while ep%d%s in state '%s'\n",
854 			dwc3_ep_event_string(event->endpoint_event),
855 			epnum >> 1, (epnum & 1) ? "in" : "out",
856 			dwc3_ep0_state_string(dwc->ep0state));
857 
858 	switch (event->endpoint_event) {
859 	case DWC3_DEPEVT_XFERCOMPLETE:
860 		dwc3_ep0_xfer_complete(dwc, event);
861 		break;
862 
863 	case DWC3_DEPEVT_XFERNOTREADY:
864 		dwc3_ep0_xfernotready(dwc, event);
865 		break;
866 
867 	case DWC3_DEPEVT_XFERINPROGRESS:
868 	case DWC3_DEPEVT_RXTXFIFOEVT:
869 	case DWC3_DEPEVT_STREAMEVT:
870 	case DWC3_DEPEVT_EPCMDCMPLT:
871 		break;
872 	}
873 }
874