1// SPDX-License-Identifier: GPL-2.0
2/*
3 * mtu3_gadget_ep0.c - MediaTek USB3 DRD peripheral driver ep0 handling
4 *
5 * Copyright (c) 2016 MediaTek Inc.
6 *
7 * Author:  Chunfeng.Yun <chunfeng.yun@mediatek.com>
8 */
9
10#include <linux/iopoll.h>
11#include <linux/usb/composite.h>
12
13#include "mtu3.h"
14#include "mtu3_debug.h"
15#include "mtu3_trace.h"
16
17/* ep0 is always mtu3->in_eps[0] */
18#define	next_ep0_request(mtu)	next_request((mtu)->ep0)
19
20/* for high speed test mode; see USB 2.0 spec 7.1.20 */
21static const u8 mtu3_test_packet[53] = {
22	/* implicit SYNC then DATA0 to start */
23
24	/* JKJKJKJK x9 */
25	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
26	/* JJKKJJKK x8 */
27	0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
28	/* JJJJKKKK x8 */
29	0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee,
30	/* JJJJJJJKKKKKKK x8 */
31	0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
32	/* JJJJJJJK x8 */
33	0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd,
34	/* JKKKKKKK x10, JK */
35	0xfc, 0x7e, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0x7e,
36	/* implicit CRC16 then EOP to end */
37};
38
39static char *decode_ep0_state(struct mtu3 *mtu)
40{
41	switch (mtu->ep0_state) {
42	case MU3D_EP0_STATE_SETUP:
43		return "SETUP";
44	case MU3D_EP0_STATE_TX:
45		return "IN";
46	case MU3D_EP0_STATE_RX:
47		return "OUT";
48	case MU3D_EP0_STATE_TX_END:
49		return "TX-END";
50	case MU3D_EP0_STATE_STALL:
51		return "STALL";
52	default:
53		return "??";
54	}
55}
56
57static void ep0_req_giveback(struct mtu3 *mtu, struct usb_request *req)
58{
59	mtu3_req_complete(mtu->ep0, req, 0);
60}
61
62static int
63forward_to_driver(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
64__releases(mtu->lock)
65__acquires(mtu->lock)
66{
67	int ret;
68
69	if (!mtu->gadget_driver || !mtu->async_callbacks)
70		return -EOPNOTSUPP;
71
72	spin_unlock(&mtu->lock);
73	ret = mtu->gadget_driver->setup(&mtu->g, setup);
74	spin_lock(&mtu->lock);
75
76	dev_dbg(mtu->dev, "%s ret %d\n", __func__, ret);
77	return ret;
78}
79
80static void ep0_write_fifo(struct mtu3_ep *mep, const u8 *src, u16 len)
81{
82	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
83	u16 index = 0;
84
85	dev_dbg(mep->mtu->dev, "%s: ep%din, len=%d, buf=%p\n",
86		__func__, mep->epnum, len, src);
87
88	if (len >= 4) {
89		iowrite32_rep(fifo, src, len >> 2);
90		index = len & ~0x03;
91	}
92	if (len & 0x02) {
93		writew(*(u16 *)&src[index], fifo);
94		index += 2;
95	}
96	if (len & 0x01)
97		writeb(src[index], fifo);
98}
99
100static void ep0_read_fifo(struct mtu3_ep *mep, u8 *dst, u16 len)
101{
102	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
103	u32 value;
104	u16 index = 0;
105
106	dev_dbg(mep->mtu->dev, "%s: ep%dout len=%d buf=%p\n",
107		 __func__, mep->epnum, len, dst);
108
109	if (len >= 4) {
110		ioread32_rep(fifo, dst, len >> 2);
111		index = len & ~0x03;
112	}
113	if (len & 0x3) {
114		value = readl(fifo);
115		memcpy(&dst[index], &value, len & 0x3);
116	}
117
118}
119
120static void ep0_load_test_packet(struct mtu3 *mtu)
121{
122	/*
123	 * because the length of test packet is less than max packet of HS ep0,
124	 * write it into fifo directly.
125	 */
126	ep0_write_fifo(mtu->ep0, mtu3_test_packet, sizeof(mtu3_test_packet));
127}
128
129/*
130 * A. send STALL for setup transfer without data stage:
131 *		set SENDSTALL and SETUPPKTRDY at the same time;
132 * B. send STALL for other cases:
133 *		set SENDSTALL only.
134 */
135static void ep0_stall_set(struct mtu3_ep *mep0, bool set, u32 pktrdy)
136{
137	struct mtu3 *mtu = mep0->mtu;
138	void __iomem *mbase = mtu->mac_base;
139	u32 csr;
140
141	/* EP0_SENTSTALL is W1C */
142	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
143	if (set)
144		csr |= EP0_SENDSTALL | pktrdy;
145	else
146		csr = (csr & ~EP0_SENDSTALL) | EP0_SENTSTALL;
147	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
148
149	mtu->delayed_status = false;
150	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
151
152	dev_dbg(mtu->dev, "ep0: %s STALL, ep0_state: %s\n",
153		set ? "SEND" : "CLEAR", decode_ep0_state(mtu));
154}
155
156static void ep0_do_status_stage(struct mtu3 *mtu)
157{
158	void __iomem *mbase = mtu->mac_base;
159	u32 value;
160
161	value = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
162	mtu3_writel(mbase, U3D_EP0CSR, value | EP0_SETUPPKTRDY | EP0_DATAEND);
163}
164
165static int ep0_queue(struct mtu3_ep *mep0, struct mtu3_request *mreq);
166
167static void ep0_dummy_complete(struct usb_ep *ep, struct usb_request *req)
168{}
169
170static void ep0_set_sel_complete(struct usb_ep *ep, struct usb_request *req)
171{
172	struct mtu3_request *mreq;
173	struct mtu3 *mtu;
174	struct usb_set_sel_req sel;
175
176	memcpy(&sel, req->buf, sizeof(sel));
177
178	mreq = to_mtu3_request(req);
179	mtu = mreq->mtu;
180	dev_dbg(mtu->dev, "u1sel:%d, u1pel:%d, u2sel:%d, u2pel:%d\n",
181		sel.u1_sel, sel.u1_pel, sel.u2_sel, sel.u2_pel);
182}
183
184/* queue data stage to handle 6 byte SET_SEL request */
185static int ep0_set_sel(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
186{
187	int ret;
188	u16 length = le16_to_cpu(setup->wLength);
189
190	if (unlikely(length != 6)) {
191		dev_err(mtu->dev, "%s wrong wLength:%d\n",
192			__func__, length);
193		return -EINVAL;
194	}
195
196	mtu->ep0_req.mep = mtu->ep0;
197	mtu->ep0_req.request.length = 6;
198	mtu->ep0_req.request.buf = mtu->setup_buf;
199	mtu->ep0_req.request.complete = ep0_set_sel_complete;
200	ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
201
202	return ret < 0 ? ret : 1;
203}
204
205static int
206ep0_get_status(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
207{
208	struct mtu3_ep *mep = NULL;
209	int handled = 1;
210	u8 result[2] = {0, 0};
211	u8 epnum = 0;
212	int is_in;
213
214	switch (setup->bRequestType & USB_RECIP_MASK) {
215	case USB_RECIP_DEVICE:
216		result[0] = mtu->is_self_powered << USB_DEVICE_SELF_POWERED;
217		result[0] |= mtu->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
218
219		if (mtu->g.speed >= USB_SPEED_SUPER) {
220			result[0] |= mtu->u1_enable << USB_DEV_STAT_U1_ENABLED;
221			result[0] |= mtu->u2_enable << USB_DEV_STAT_U2_ENABLED;
222		}
223
224		dev_dbg(mtu->dev, "%s result=%x, U1=%x, U2=%x\n", __func__,
225			result[0], mtu->u1_enable, mtu->u2_enable);
226
227		break;
228	case USB_RECIP_INTERFACE:
229		/* status of function remote wakeup, forward request */
230		handled = 0;
231		break;
232	case USB_RECIP_ENDPOINT:
233		epnum = (u8) le16_to_cpu(setup->wIndex);
234		is_in = epnum & USB_DIR_IN;
235		epnum &= USB_ENDPOINT_NUMBER_MASK;
236
237		if (epnum >= mtu->num_eps) {
238			handled = -EINVAL;
239			break;
240		}
241		if (!epnum)
242			break;
243
244		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
245		if (!mep->desc) {
246			handled = -EINVAL;
247			break;
248		}
249		if (mep->flags & MTU3_EP_STALL)
250			result[0] |= 1 << USB_ENDPOINT_HALT;
251
252		break;
253	default:
254		/* class, vendor, etc ... delegate */
255		handled = 0;
256		break;
257	}
258
259	if (handled > 0) {
260		int ret;
261
262		/* prepare a data stage for GET_STATUS */
263		dev_dbg(mtu->dev, "get_status=%x\n", *(u16 *)result);
264		memcpy(mtu->setup_buf, result, sizeof(result));
265		mtu->ep0_req.mep = mtu->ep0;
266		mtu->ep0_req.request.length = 2;
267		mtu->ep0_req.request.buf = &mtu->setup_buf;
268		mtu->ep0_req.request.complete = ep0_dummy_complete;
269		ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
270		if (ret < 0)
271			handled = ret;
272	}
273	return handled;
274}
275
276static int handle_test_mode(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
277{
278	void __iomem *mbase = mtu->mac_base;
279	int handled = 1;
280	u32 value;
281
282	switch (le16_to_cpu(setup->wIndex) >> 8) {
283	case USB_TEST_J:
284		dev_dbg(mtu->dev, "USB_TEST_J\n");
285		mtu->test_mode_nr = TEST_J_MODE;
286		break;
287	case USB_TEST_K:
288		dev_dbg(mtu->dev, "USB_TEST_K\n");
289		mtu->test_mode_nr = TEST_K_MODE;
290		break;
291	case USB_TEST_SE0_NAK:
292		dev_dbg(mtu->dev, "USB_TEST_SE0_NAK\n");
293		mtu->test_mode_nr = TEST_SE0_NAK_MODE;
294		break;
295	case USB_TEST_PACKET:
296		dev_dbg(mtu->dev, "USB_TEST_PACKET\n");
297		mtu->test_mode_nr = TEST_PACKET_MODE;
298		break;
299	default:
300		handled = -EINVAL;
301		goto out;
302	}
303
304	mtu->test_mode = true;
305
306	/* no TX completion interrupt, and need restart platform after test */
307	if (mtu->test_mode_nr == TEST_PACKET_MODE)
308		ep0_load_test_packet(mtu);
309
310	/* send status before entering test mode. */
311	ep0_do_status_stage(mtu);
312
313	/* wait for ACK status sent by host */
314	readl_poll_timeout_atomic(mbase + U3D_EP0CSR, value,
315			!(value & EP0_DATAEND), 100, 5000);
316
317	mtu3_writel(mbase, U3D_USB2_TEST_MODE, mtu->test_mode_nr);
318
319	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
320
321out:
322	return handled;
323}
324
325static int ep0_handle_feature_dev(struct mtu3 *mtu,
326		struct usb_ctrlrequest *setup, bool set)
327{
328	void __iomem *mbase = mtu->mac_base;
329	int handled = -EINVAL;
330	u32 lpc;
331
332	switch (le16_to_cpu(setup->wValue)) {
333	case USB_DEVICE_REMOTE_WAKEUP:
334		mtu->may_wakeup = !!set;
335		handled = 1;
336		break;
337	case USB_DEVICE_TEST_MODE:
338		if (!set || (mtu->g.speed != USB_SPEED_HIGH) ||
339			(le16_to_cpu(setup->wIndex) & 0xff))
340			break;
341
342		handled = handle_test_mode(mtu, setup);
343		break;
344	case USB_DEVICE_U1_ENABLE:
345		if (mtu->g.speed < USB_SPEED_SUPER ||
346		    mtu->g.state != USB_STATE_CONFIGURED)
347			break;
348
349		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
350		if (set)
351			lpc |= SW_U1_REQUEST_ENABLE;
352		else
353			lpc &= ~SW_U1_REQUEST_ENABLE;
354		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
355
356		mtu->u1_enable = !!set;
357		handled = 1;
358		break;
359	case USB_DEVICE_U2_ENABLE:
360		if (mtu->g.speed < USB_SPEED_SUPER ||
361		    mtu->g.state != USB_STATE_CONFIGURED)
362			break;
363
364		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
365		if (set)
366			lpc |= SW_U2_REQUEST_ENABLE;
367		else
368			lpc &= ~SW_U2_REQUEST_ENABLE;
369		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
370
371		mtu->u2_enable = !!set;
372		handled = 1;
373		break;
374	default:
375		handled = -EINVAL;
376		break;
377	}
378	return handled;
379}
380
381static int ep0_handle_feature(struct mtu3 *mtu,
382		struct usb_ctrlrequest *setup, bool set)
383{
384	struct mtu3_ep *mep;
385	int handled = -EINVAL;
386	int is_in;
387	u16 value;
388	u16 index;
389	u8 epnum;
390
391	value = le16_to_cpu(setup->wValue);
392	index = le16_to_cpu(setup->wIndex);
393
394	switch (setup->bRequestType & USB_RECIP_MASK) {
395	case USB_RECIP_DEVICE:
396		handled = ep0_handle_feature_dev(mtu, setup, set);
397		break;
398	case USB_RECIP_INTERFACE:
399		/* superspeed only */
400		if (value == USB_INTRF_FUNC_SUSPEND &&
401		    mtu->g.speed >= USB_SPEED_SUPER) {
402			/* forward the request for function suspend */
403			mtu->may_wakeup = !!(index & USB_INTRF_FUNC_SUSPEND_RW);
404			handled = 0;
405		}
406		break;
407	case USB_RECIP_ENDPOINT:
408		epnum = index & USB_ENDPOINT_NUMBER_MASK;
409		if (epnum == 0 || epnum >= mtu->num_eps ||
410			value != USB_ENDPOINT_HALT)
411			break;
412
413		is_in = index & USB_DIR_IN;
414		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
415		if (!mep->desc)
416			break;
417
418		handled = 1;
419		/* ignore request if endpoint is wedged */
420		if (mep->flags & MTU3_EP_WEDGE)
421			break;
422
423		mtu3_ep_stall_set(mep, set);
424		break;
425	default:
426		/* class, vendor, etc ... delegate */
427		handled = 0;
428		break;
429	}
430	return handled;
431}
432
433/*
434 * handle all control requests can be handled
435 * returns:
436 *	negative errno - error happened
437 *	zero - need delegate SETUP to gadget driver
438 *	positive - already handled
439 */
440static int handle_standard_request(struct mtu3 *mtu,
441			  struct usb_ctrlrequest *setup)
442{
443	void __iomem *mbase = mtu->mac_base;
444	enum usb_device_state state = mtu->g.state;
445	int handled = -EINVAL;
446	u32 dev_conf;
447	u16 value;
448
449	value = le16_to_cpu(setup->wValue);
450
451	/* the gadget driver handles everything except what we must handle */
452	switch (setup->bRequest) {
453	case USB_REQ_SET_ADDRESS:
454		/* change it after the status stage */
455		mtu->address = (u8) (value & 0x7f);
456		dev_dbg(mtu->dev, "set address to 0x%x\n", mtu->address);
457
458		dev_conf = mtu3_readl(mbase, U3D_DEVICE_CONF);
459		dev_conf &= ~DEV_ADDR_MSK;
460		dev_conf |= DEV_ADDR(mtu->address);
461		mtu3_writel(mbase, U3D_DEVICE_CONF, dev_conf);
462
463		if (mtu->address)
464			usb_gadget_set_state(&mtu->g, USB_STATE_ADDRESS);
465		else
466			usb_gadget_set_state(&mtu->g, USB_STATE_DEFAULT);
467
468		handled = 1;
469		break;
470	case USB_REQ_SET_CONFIGURATION:
471		if (state == USB_STATE_ADDRESS) {
472			usb_gadget_set_state(&mtu->g,
473					USB_STATE_CONFIGURED);
474		} else if (state == USB_STATE_CONFIGURED) {
475			/*
476			 * USB2 spec sec 9.4.7, if wValue is 0 then dev
477			 * is moved to addressed state
478			 */
479			if (!value)
480				usb_gadget_set_state(&mtu->g,
481						USB_STATE_ADDRESS);
482		}
483		handled = 0;
484		break;
485	case USB_REQ_CLEAR_FEATURE:
486		handled = ep0_handle_feature(mtu, setup, 0);
487		break;
488	case USB_REQ_SET_FEATURE:
489		handled = ep0_handle_feature(mtu, setup, 1);
490		break;
491	case USB_REQ_GET_STATUS:
492		handled = ep0_get_status(mtu, setup);
493		break;
494	case USB_REQ_SET_SEL:
495		handled = ep0_set_sel(mtu, setup);
496		break;
497	case USB_REQ_SET_ISOCH_DELAY:
498		handled = 1;
499		break;
500	default:
501		/* delegate SET_CONFIGURATION, etc */
502		handled = 0;
503	}
504
505	return handled;
506}
507
508/* receive an data packet (OUT) */
509static void ep0_rx_state(struct mtu3 *mtu)
510{
511	struct mtu3_request *mreq;
512	struct usb_request *req;
513	void __iomem *mbase = mtu->mac_base;
514	u32 maxp;
515	u32 csr;
516	u16 count = 0;
517
518	dev_dbg(mtu->dev, "%s\n", __func__);
519
520	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
521	mreq = next_ep0_request(mtu);
522	req = &mreq->request;
523
524	/* read packet and ack; or stall because of gadget driver bug */
525	if (req) {
526		void *buf = req->buf + req->actual;
527		unsigned int len = req->length - req->actual;
528
529		/* read the buffer */
530		count = mtu3_readl(mbase, U3D_RXCOUNT0);
531		if (count > len) {
532			req->status = -EOVERFLOW;
533			count = len;
534		}
535		ep0_read_fifo(mtu->ep0, buf, count);
536		req->actual += count;
537		csr |= EP0_RXPKTRDY;
538
539		maxp = mtu->g.ep0->maxpacket;
540		if (count < maxp || req->actual == req->length) {
541			mtu->ep0_state = MU3D_EP0_STATE_SETUP;
542			dev_dbg(mtu->dev, "ep0 state: %s\n",
543				decode_ep0_state(mtu));
544
545			csr |= EP0_DATAEND;
546		} else {
547			req = NULL;
548		}
549	} else {
550		csr |= EP0_RXPKTRDY | EP0_SENDSTALL;
551		dev_dbg(mtu->dev, "%s: SENDSTALL\n", __func__);
552	}
553
554	mtu3_writel(mbase, U3D_EP0CSR, csr);
555
556	/* give back the request if have received all data */
557	if (req)
558		ep0_req_giveback(mtu, req);
559
560}
561
562/* transmitting to the host (IN) */
563static void ep0_tx_state(struct mtu3 *mtu)
564{
565	struct mtu3_request *mreq = next_ep0_request(mtu);
566	struct usb_request *req;
567	u32 csr;
568	u8 *src;
569	u32 count;
570	u32 maxp;
571
572	dev_dbg(mtu->dev, "%s\n", __func__);
573
574	if (!mreq)
575		return;
576
577	maxp = mtu->g.ep0->maxpacket;
578	req = &mreq->request;
579
580	/* load the data */
581	src = (u8 *)req->buf + req->actual;
582	count = min(maxp, req->length - req->actual);
583	if (count)
584		ep0_write_fifo(mtu->ep0, src, count);
585
586	dev_dbg(mtu->dev, "%s act=%d, len=%d, cnt=%d, maxp=%d zero=%d\n",
587		 __func__, req->actual, req->length, count, maxp, req->zero);
588
589	req->actual += count;
590
591	if ((count < maxp)
592		|| ((req->actual == req->length) && !req->zero))
593		mtu->ep0_state = MU3D_EP0_STATE_TX_END;
594
595	/* send it out, triggering a "txpktrdy cleared" irq */
596	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
597	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr | EP0_TXPKTRDY);
598
599	dev_dbg(mtu->dev, "%s ep0csr=0x%x\n", __func__,
600		mtu3_readl(mtu->mac_base, U3D_EP0CSR));
601}
602
603static void ep0_read_setup(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
604{
605	struct mtu3_request *mreq;
606	u32 count;
607	u32 csr;
608
609	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
610	count = mtu3_readl(mtu->mac_base, U3D_RXCOUNT0);
611
612	ep0_read_fifo(mtu->ep0, (u8 *)setup, count);
613
614	dev_dbg(mtu->dev, "SETUP req%02x.%02x v%04x i%04x l%04x\n",
615		 setup->bRequestType, setup->bRequest,
616		 le16_to_cpu(setup->wValue), le16_to_cpu(setup->wIndex),
617		 le16_to_cpu(setup->wLength));
618
619	/* clean up any leftover transfers */
620	mreq = next_ep0_request(mtu);
621	if (mreq)
622		ep0_req_giveback(mtu, &mreq->request);
623
624	if (le16_to_cpu(setup->wLength) == 0) {
625		;	/* no data stage, nothing to do */
626	} else if (setup->bRequestType & USB_DIR_IN) {
627		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
628			csr | EP0_SETUPPKTRDY | EP0_DPHTX);
629		mtu->ep0_state = MU3D_EP0_STATE_TX;
630	} else {
631		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
632			(csr | EP0_SETUPPKTRDY) & (~EP0_DPHTX));
633		mtu->ep0_state = MU3D_EP0_STATE_RX;
634	}
635}
636
637static int ep0_handle_setup(struct mtu3 *mtu)
638__releases(mtu->lock)
639__acquires(mtu->lock)
640{
641	struct usb_ctrlrequest setup;
642	struct mtu3_request *mreq;
643	int handled = 0;
644
645	ep0_read_setup(mtu, &setup);
646	trace_mtu3_handle_setup(&setup);
647
648	if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
649		handled = handle_standard_request(mtu, &setup);
650
651	dev_dbg(mtu->dev, "handled %d, ep0_state: %s\n",
652		 handled, decode_ep0_state(mtu));
653
654	if (handled < 0)
655		goto stall;
656	else if (handled > 0)
657		goto finish;
658
659	handled = forward_to_driver(mtu, &setup);
660	if (handled < 0) {
661stall:
662		dev_dbg(mtu->dev, "%s stall (%d)\n", __func__, handled);
663
664		ep0_stall_set(mtu->ep0, true,
665			le16_to_cpu(setup.wLength) ? 0 : EP0_SETUPPKTRDY);
666
667		return 0;
668	}
669
670finish:
671	if (mtu->test_mode) {
672		;	/* nothing to do */
673	} else if (handled == USB_GADGET_DELAYED_STATUS) {
674
675		mreq = next_ep0_request(mtu);
676		if (mreq) {
677			/* already asked us to continue delayed status */
678			ep0_do_status_stage(mtu);
679			ep0_req_giveback(mtu, &mreq->request);
680		} else {
681			/* do delayed STATUS stage till receive ep0_queue */
682			mtu->delayed_status = true;
683		}
684	} else if (le16_to_cpu(setup.wLength) == 0) { /* no data stage */
685
686		ep0_do_status_stage(mtu);
687		/* complete zlp request directly */
688		mreq = next_ep0_request(mtu);
689		if (mreq && !mreq->request.length)
690			ep0_req_giveback(mtu, &mreq->request);
691	}
692
693	return 0;
694}
695
696irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu)
697{
698	void __iomem *mbase = mtu->mac_base;
699	struct mtu3_request *mreq;
700	u32 int_status;
701	irqreturn_t ret = IRQ_NONE;
702	u32 csr;
703	u32 len;
704
705	int_status = mtu3_readl(mbase, U3D_EPISR);
706	int_status &= mtu3_readl(mbase, U3D_EPIER);
707	mtu3_writel(mbase, U3D_EPISR, int_status); /* W1C */
708
709	/* only handle ep0's */
710	if (!(int_status & (EP0ISR | SETUPENDISR)))
711		return IRQ_NONE;
712
713	/* abort current SETUP, and process new one */
714	if (int_status & SETUPENDISR)
715		mtu->ep0_state = MU3D_EP0_STATE_SETUP;
716
717	csr = mtu3_readl(mbase, U3D_EP0CSR);
718
719	dev_dbg(mtu->dev, "%s csr=0x%x\n", __func__, csr);
720
721	/* we sent a stall.. need to clear it now.. */
722	if (csr & EP0_SENTSTALL) {
723		ep0_stall_set(mtu->ep0, false, 0);
724		csr = mtu3_readl(mbase, U3D_EP0CSR);
725		ret = IRQ_HANDLED;
726	}
727	dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
728	mtu3_dbg_trace(mtu->dev, "ep0_state %s", decode_ep0_state(mtu));
729
730	switch (mtu->ep0_state) {
731	case MU3D_EP0_STATE_TX:
732		/* irq on clearing txpktrdy */
733		if ((csr & EP0_FIFOFULL) == 0) {
734			ep0_tx_state(mtu);
735			ret = IRQ_HANDLED;
736		}
737		break;
738	case MU3D_EP0_STATE_RX:
739		/* irq on set rxpktrdy */
740		if (csr & EP0_RXPKTRDY) {
741			ep0_rx_state(mtu);
742			ret = IRQ_HANDLED;
743		}
744		break;
745	case MU3D_EP0_STATE_TX_END:
746		mtu3_writel(mbase, U3D_EP0CSR,
747			(csr & EP0_W1C_BITS) | EP0_DATAEND);
748
749		mreq = next_ep0_request(mtu);
750		if (mreq)
751			ep0_req_giveback(mtu, &mreq->request);
752
753		mtu->ep0_state = MU3D_EP0_STATE_SETUP;
754		ret = IRQ_HANDLED;
755		dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
756		break;
757	case MU3D_EP0_STATE_SETUP:
758		if (!(csr & EP0_SETUPPKTRDY))
759			break;
760
761		len = mtu3_readl(mbase, U3D_RXCOUNT0);
762		if (len != 8) {
763			dev_err(mtu->dev, "SETUP packet len %d != 8 ?\n", len);
764			break;
765		}
766
767		ep0_handle_setup(mtu);
768		ret = IRQ_HANDLED;
769		break;
770	default:
771		/* can't happen */
772		ep0_stall_set(mtu->ep0, true, 0);
773		WARN_ON(1);
774		break;
775	}
776
777	return ret;
778}
779
780
781static int mtu3_ep0_enable(struct usb_ep *ep,
782	const struct usb_endpoint_descriptor *desc)
783{
784	/* always enabled */
785	return -EINVAL;
786}
787
788static int mtu3_ep0_disable(struct usb_ep *ep)
789{
790	/* always enabled */
791	return -EINVAL;
792}
793
794static int ep0_queue(struct mtu3_ep *mep, struct mtu3_request *mreq)
795{
796	struct mtu3 *mtu = mep->mtu;
797
798	mreq->mtu = mtu;
799	mreq->request.actual = 0;
800	mreq->request.status = -EINPROGRESS;
801
802	dev_dbg(mtu->dev, "%s %s (ep0_state: %s), len#%d\n", __func__,
803		mep->name, decode_ep0_state(mtu), mreq->request.length);
804
805	switch (mtu->ep0_state) {
806	case MU3D_EP0_STATE_SETUP:
807	case MU3D_EP0_STATE_RX:	/* control-OUT data */
808	case MU3D_EP0_STATE_TX:	/* control-IN data */
809		break;
810	default:
811		dev_err(mtu->dev, "%s, error in ep0 state %s\n", __func__,
812			decode_ep0_state(mtu));
813		return -EINVAL;
814	}
815
816	if (mtu->delayed_status) {
817
818		mtu->delayed_status = false;
819		ep0_do_status_stage(mtu);
820		/* needn't giveback the request for handling delay STATUS */
821		return 0;
822	}
823
824	if (!list_empty(&mep->req_list))
825		return -EBUSY;
826
827	list_add_tail(&mreq->list, &mep->req_list);
828
829	/* sequence #1, IN ... start writing the data */
830	if (mtu->ep0_state == MU3D_EP0_STATE_TX)
831		ep0_tx_state(mtu);
832
833	return 0;
834}
835
836static int mtu3_ep0_queue(struct usb_ep *ep,
837	struct usb_request *req, gfp_t gfp)
838{
839	struct mtu3_ep *mep;
840	struct mtu3_request *mreq;
841	struct mtu3 *mtu;
842	unsigned long flags;
843	int ret = 0;
844
845	if (!ep || !req)
846		return -EINVAL;
847
848	mep = to_mtu3_ep(ep);
849	mtu = mep->mtu;
850	mreq = to_mtu3_request(req);
851
852	spin_lock_irqsave(&mtu->lock, flags);
853	ret = ep0_queue(mep, mreq);
854	spin_unlock_irqrestore(&mtu->lock, flags);
855	return ret;
856}
857
858static int mtu3_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
859{
860	/* we just won't support this */
861	return -EINVAL;
862}
863
864static int mtu3_ep0_halt(struct usb_ep *ep, int value)
865{
866	struct mtu3_ep *mep;
867	struct mtu3 *mtu;
868	unsigned long flags;
869	int ret = 0;
870
871	if (!ep || !value)
872		return -EINVAL;
873
874	mep = to_mtu3_ep(ep);
875	mtu = mep->mtu;
876
877	dev_dbg(mtu->dev, "%s\n", __func__);
878
879	spin_lock_irqsave(&mtu->lock, flags);
880
881	if (!list_empty(&mep->req_list)) {
882		ret = -EBUSY;
883		goto cleanup;
884	}
885
886	switch (mtu->ep0_state) {
887	/*
888	 * stalls are usually issued after parsing SETUP packet, either
889	 * directly in irq context from setup() or else later.
890	 */
891	case MU3D_EP0_STATE_TX:
892	case MU3D_EP0_STATE_TX_END:
893	case MU3D_EP0_STATE_RX:
894	case MU3D_EP0_STATE_SETUP:
895		ep0_stall_set(mtu->ep0, true, 0);
896		break;
897	default:
898		dev_dbg(mtu->dev, "ep0 can't halt in state %s\n",
899			decode_ep0_state(mtu));
900		ret = -EINVAL;
901	}
902
903cleanup:
904	spin_unlock_irqrestore(&mtu->lock, flags);
905	return ret;
906}
907
908const struct usb_ep_ops mtu3_ep0_ops = {
909	.enable = mtu3_ep0_enable,
910	.disable = mtu3_ep0_disable,
911	.alloc_request = mtu3_alloc_request,
912	.free_request = mtu3_free_request,
913	.queue = mtu3_ep0_queue,
914	.dequeue = mtu3_ep0_dequeue,
915	.set_halt = mtu3_ep0_halt,
916};
917