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
57static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum);
58
59static 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
75static 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
122static 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
170int 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
201out:
202	spin_unlock_irqrestore(&dwc->lock, flags);
203
204	return ret;
205}
206
207static 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
227void 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
236static 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
253static void dwc3_ep0_status_cmpl(struct usb_ep *ep, struct usb_request *req)
254{
255}
256/*
257 * ch 9.4.5
258 */
259static 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
308static 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
399static 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
428static 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
438static 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
472static 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
506static 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
538err:
539	dwc3_ep0_stall_and_restart(dwc);
540}
541
542static 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
593static 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
622static 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
651static 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
657static 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
719static 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
731static 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
744static 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
848void 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