xref: /linux/drivers/usb/mtu3/mtu3_gadget_ep0.c (revision e3b9f1e81de2083f359bacd2a94bf1c024f2ede0)
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/usb/composite.h>
11 
12 #include "mtu3.h"
13 
14 /* ep0 is always mtu3->in_eps[0] */
15 #define	next_ep0_request(mtu)	next_request((mtu)->ep0)
16 
17 /* for high speed test mode; see USB 2.0 spec 7.1.20 */
18 static const u8 mtu3_test_packet[53] = {
19 	/* implicit SYNC then DATA0 to start */
20 
21 	/* JKJKJKJK x9 */
22 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
23 	/* JJKKJJKK x8 */
24 	0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
25 	/* JJJJKKKK x8 */
26 	0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee,
27 	/* JJJJJJJKKKKKKK x8 */
28 	0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
29 	/* JJJJJJJK x8 */
30 	0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd,
31 	/* JKKKKKKK x10, JK */
32 	0xfc, 0x7e, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0x7e,
33 	/* implicit CRC16 then EOP to end */
34 };
35 
36 static char *decode_ep0_state(struct mtu3 *mtu)
37 {
38 	switch (mtu->ep0_state) {
39 	case MU3D_EP0_STATE_SETUP:
40 		return "SETUP";
41 	case MU3D_EP0_STATE_TX:
42 		return "IN";
43 	case MU3D_EP0_STATE_RX:
44 		return "OUT";
45 	case MU3D_EP0_STATE_TX_END:
46 		return "TX-END";
47 	case MU3D_EP0_STATE_STALL:
48 		return "STALL";
49 	default:
50 		return "??";
51 	}
52 }
53 
54 static void ep0_req_giveback(struct mtu3 *mtu, struct usb_request *req)
55 {
56 	mtu3_req_complete(mtu->ep0, req, 0);
57 }
58 
59 static int
60 forward_to_driver(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
61 __releases(mtu->lock)
62 __acquires(mtu->lock)
63 {
64 	int ret;
65 
66 	if (!mtu->gadget_driver)
67 		return -EOPNOTSUPP;
68 
69 	spin_unlock(&mtu->lock);
70 	ret = mtu->gadget_driver->setup(&mtu->g, setup);
71 	spin_lock(&mtu->lock);
72 
73 	dev_dbg(mtu->dev, "%s ret %d\n", __func__, ret);
74 	return ret;
75 }
76 
77 static void ep0_write_fifo(struct mtu3_ep *mep, const u8 *src, u16 len)
78 {
79 	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
80 	u16 index = 0;
81 
82 	dev_dbg(mep->mtu->dev, "%s: ep%din, len=%d, buf=%p\n",
83 		__func__, mep->epnum, len, src);
84 
85 	if (len >= 4) {
86 		iowrite32_rep(fifo, src, len >> 2);
87 		index = len & ~0x03;
88 	}
89 	if (len & 0x02) {
90 		writew(*(u16 *)&src[index], fifo);
91 		index += 2;
92 	}
93 	if (len & 0x01)
94 		writeb(src[index], fifo);
95 }
96 
97 static void ep0_read_fifo(struct mtu3_ep *mep, u8 *dst, u16 len)
98 {
99 	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
100 	u32 value;
101 	u16 index = 0;
102 
103 	dev_dbg(mep->mtu->dev, "%s: ep%dout len=%d buf=%p\n",
104 		 __func__, mep->epnum, len, dst);
105 
106 	if (len >= 4) {
107 		ioread32_rep(fifo, dst, len >> 2);
108 		index = len & ~0x03;
109 	}
110 	if (len & 0x3) {
111 		value = readl(fifo);
112 		memcpy(&dst[index], &value, len & 0x3);
113 	}
114 
115 }
116 
117 static void ep0_load_test_packet(struct mtu3 *mtu)
118 {
119 	/*
120 	 * because the length of test packet is less than max packet of HS ep0,
121 	 * write it into fifo directly.
122 	 */
123 	ep0_write_fifo(mtu->ep0, mtu3_test_packet, sizeof(mtu3_test_packet));
124 }
125 
126 /*
127  * A. send STALL for setup transfer without data stage:
128  *		set SENDSTALL and SETUPPKTRDY at the same time;
129  * B. send STALL for other cases:
130  *		set SENDSTALL only.
131  */
132 static void ep0_stall_set(struct mtu3_ep *mep0, bool set, u32 pktrdy)
133 {
134 	struct mtu3 *mtu = mep0->mtu;
135 	void __iomem *mbase = mtu->mac_base;
136 	u32 csr;
137 
138 	/* EP0_SENTSTALL is W1C */
139 	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
140 	if (set)
141 		csr |= EP0_SENDSTALL | pktrdy;
142 	else
143 		csr = (csr & ~EP0_SENDSTALL) | EP0_SENTSTALL;
144 	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
145 
146 	mtu->delayed_status = false;
147 	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
148 
149 	dev_dbg(mtu->dev, "ep0: %s STALL, ep0_state: %s\n",
150 		set ? "SEND" : "CLEAR", decode_ep0_state(mtu));
151 }
152 
153 static int ep0_queue(struct mtu3_ep *mep0, struct mtu3_request *mreq);
154 
155 static void ep0_dummy_complete(struct usb_ep *ep, struct usb_request *req)
156 {}
157 
158 static void ep0_set_sel_complete(struct usb_ep *ep, struct usb_request *req)
159 {
160 	struct mtu3_request *mreq;
161 	struct mtu3 *mtu;
162 	struct usb_set_sel_req sel;
163 
164 	memcpy(&sel, req->buf, sizeof(sel));
165 
166 	mreq = to_mtu3_request(req);
167 	mtu = mreq->mtu;
168 	dev_dbg(mtu->dev, "u1sel:%d, u1pel:%d, u2sel:%d, u2pel:%d\n",
169 		sel.u1_sel, sel.u1_pel, sel.u2_sel, sel.u2_pel);
170 }
171 
172 /* queue data stage to handle 6 byte SET_SEL request */
173 static int ep0_set_sel(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
174 {
175 	int ret;
176 	u16 length = le16_to_cpu(setup->wLength);
177 
178 	if (unlikely(length != 6)) {
179 		dev_err(mtu->dev, "%s wrong wLength:%d\n",
180 			__func__, length);
181 		return -EINVAL;
182 	}
183 
184 	mtu->ep0_req.mep = mtu->ep0;
185 	mtu->ep0_req.request.length = 6;
186 	mtu->ep0_req.request.buf = mtu->setup_buf;
187 	mtu->ep0_req.request.complete = ep0_set_sel_complete;
188 	ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
189 
190 	return ret < 0 ? ret : 1;
191 }
192 
193 static int
194 ep0_get_status(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
195 {
196 	struct mtu3_ep *mep = NULL;
197 	int handled = 1;
198 	u8 result[2] = {0, 0};
199 	u8 epnum = 0;
200 	int is_in;
201 
202 	switch (setup->bRequestType & USB_RECIP_MASK) {
203 	case USB_RECIP_DEVICE:
204 		result[0] = mtu->is_self_powered << USB_DEVICE_SELF_POWERED;
205 		result[0] |= mtu->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
206 
207 		if (mtu->g.speed >= USB_SPEED_SUPER) {
208 			result[0] |= mtu->u1_enable << USB_DEV_STAT_U1_ENABLED;
209 			result[0] |= mtu->u2_enable << USB_DEV_STAT_U2_ENABLED;
210 		}
211 
212 		dev_dbg(mtu->dev, "%s result=%x, U1=%x, U2=%x\n", __func__,
213 			result[0], mtu->u1_enable, mtu->u2_enable);
214 
215 		break;
216 	case USB_RECIP_INTERFACE:
217 		break;
218 	case USB_RECIP_ENDPOINT:
219 		epnum = (u8) le16_to_cpu(setup->wIndex);
220 		is_in = epnum & USB_DIR_IN;
221 		epnum &= USB_ENDPOINT_NUMBER_MASK;
222 
223 		if (epnum >= mtu->num_eps) {
224 			handled = -EINVAL;
225 			break;
226 		}
227 		if (!epnum)
228 			break;
229 
230 		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
231 		if (!mep->desc) {
232 			handled = -EINVAL;
233 			break;
234 		}
235 		if (mep->flags & MTU3_EP_STALL)
236 			result[0] |= 1 << USB_ENDPOINT_HALT;
237 
238 		break;
239 	default:
240 		/* class, vendor, etc ... delegate */
241 		handled = 0;
242 		break;
243 	}
244 
245 	if (handled > 0) {
246 		int ret;
247 
248 		/* prepare a data stage for GET_STATUS */
249 		dev_dbg(mtu->dev, "get_status=%x\n", *(u16 *)result);
250 		memcpy(mtu->setup_buf, result, sizeof(result));
251 		mtu->ep0_req.mep = mtu->ep0;
252 		mtu->ep0_req.request.length = 2;
253 		mtu->ep0_req.request.buf = &mtu->setup_buf;
254 		mtu->ep0_req.request.complete = ep0_dummy_complete;
255 		ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
256 		if (ret < 0)
257 			handled = ret;
258 	}
259 	return handled;
260 }
261 
262 static int handle_test_mode(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
263 {
264 	void __iomem *mbase = mtu->mac_base;
265 	int handled = 1;
266 
267 	switch (le16_to_cpu(setup->wIndex) >> 8) {
268 	case TEST_J:
269 		dev_dbg(mtu->dev, "TEST_J\n");
270 		mtu->test_mode_nr = TEST_J_MODE;
271 		break;
272 	case TEST_K:
273 		dev_dbg(mtu->dev, "TEST_K\n");
274 		mtu->test_mode_nr = TEST_K_MODE;
275 		break;
276 	case TEST_SE0_NAK:
277 		dev_dbg(mtu->dev, "TEST_SE0_NAK\n");
278 		mtu->test_mode_nr = TEST_SE0_NAK_MODE;
279 		break;
280 	case TEST_PACKET:
281 		dev_dbg(mtu->dev, "TEST_PACKET\n");
282 		mtu->test_mode_nr = TEST_PACKET_MODE;
283 		break;
284 	default:
285 		handled = -EINVAL;
286 		goto out;
287 	}
288 
289 	mtu->test_mode = true;
290 
291 	/* no TX completion interrupt, and need restart platform after test */
292 	if (mtu->test_mode_nr == TEST_PACKET_MODE)
293 		ep0_load_test_packet(mtu);
294 
295 	mtu3_writel(mbase, U3D_USB2_TEST_MODE, mtu->test_mode_nr);
296 
297 	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
298 
299 out:
300 	return handled;
301 }
302 
303 static int ep0_handle_feature_dev(struct mtu3 *mtu,
304 		struct usb_ctrlrequest *setup, bool set)
305 {
306 	void __iomem *mbase = mtu->mac_base;
307 	int handled = -EINVAL;
308 	u32 lpc;
309 
310 	switch (le16_to_cpu(setup->wValue)) {
311 	case USB_DEVICE_REMOTE_WAKEUP:
312 		mtu->may_wakeup = !!set;
313 		handled = 1;
314 		break;
315 	case USB_DEVICE_TEST_MODE:
316 		if (!set || (mtu->g.speed != USB_SPEED_HIGH) ||
317 			(le16_to_cpu(setup->wIndex) & 0xff))
318 			break;
319 
320 		handled = handle_test_mode(mtu, setup);
321 		break;
322 	case USB_DEVICE_U1_ENABLE:
323 		if (mtu->g.speed < USB_SPEED_SUPER ||
324 		    mtu->g.state != USB_STATE_CONFIGURED)
325 			break;
326 
327 		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
328 		if (set)
329 			lpc |= SW_U1_ACCEPT_ENABLE;
330 		else
331 			lpc &= ~SW_U1_ACCEPT_ENABLE;
332 		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
333 
334 		mtu->u1_enable = !!set;
335 		handled = 1;
336 		break;
337 	case USB_DEVICE_U2_ENABLE:
338 		if (mtu->g.speed < USB_SPEED_SUPER ||
339 		    mtu->g.state != USB_STATE_CONFIGURED)
340 			break;
341 
342 		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
343 		if (set)
344 			lpc |= SW_U2_ACCEPT_ENABLE;
345 		else
346 			lpc &= ~SW_U2_ACCEPT_ENABLE;
347 		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
348 
349 		mtu->u2_enable = !!set;
350 		handled = 1;
351 		break;
352 	default:
353 		handled = -EINVAL;
354 		break;
355 	}
356 	return handled;
357 }
358 
359 static int ep0_handle_feature(struct mtu3 *mtu,
360 		struct usb_ctrlrequest *setup, bool set)
361 {
362 	struct mtu3_ep *mep;
363 	int handled = -EINVAL;
364 	int is_in;
365 	u16 value;
366 	u16 index;
367 	u8 epnum;
368 
369 	value = le16_to_cpu(setup->wValue);
370 	index = le16_to_cpu(setup->wIndex);
371 
372 	switch (setup->bRequestType & USB_RECIP_MASK) {
373 	case USB_RECIP_DEVICE:
374 		handled = ep0_handle_feature_dev(mtu, setup, set);
375 		break;
376 	case USB_RECIP_INTERFACE:
377 		/* superspeed only */
378 		if (value == USB_INTRF_FUNC_SUSPEND &&
379 		    mtu->g.speed >= USB_SPEED_SUPER) {
380 			/*
381 			 * forward the request because function drivers
382 			 * should handle it
383 			 */
384 			handled = 0;
385 		}
386 		break;
387 	case USB_RECIP_ENDPOINT:
388 		epnum = index & USB_ENDPOINT_NUMBER_MASK;
389 		if (epnum == 0 || epnum >= mtu->num_eps ||
390 			value != USB_ENDPOINT_HALT)
391 			break;
392 
393 		is_in = index & USB_DIR_IN;
394 		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
395 		if (!mep->desc)
396 			break;
397 
398 		handled = 1;
399 		/* ignore request if endpoint is wedged */
400 		if (mep->wedged)
401 			break;
402 
403 		mtu3_ep_stall_set(mep, set);
404 		break;
405 	default:
406 		/* class, vendor, etc ... delegate */
407 		handled = 0;
408 		break;
409 	}
410 	return handled;
411 }
412 
413 /*
414  * handle all control requests can be handled
415  * returns:
416  *	negative errno - error happened
417  *	zero - need delegate SETUP to gadget driver
418  *	positive - already handled
419  */
420 static int handle_standard_request(struct mtu3 *mtu,
421 			  struct usb_ctrlrequest *setup)
422 {
423 	void __iomem *mbase = mtu->mac_base;
424 	enum usb_device_state state = mtu->g.state;
425 	int handled = -EINVAL;
426 	u32 dev_conf;
427 	u16 value;
428 
429 	value = le16_to_cpu(setup->wValue);
430 
431 	/* the gadget driver handles everything except what we must handle */
432 	switch (setup->bRequest) {
433 	case USB_REQ_SET_ADDRESS:
434 		/* change it after the status stage */
435 		mtu->address = (u8) (value & 0x7f);
436 		dev_dbg(mtu->dev, "set address to 0x%x\n", mtu->address);
437 
438 		dev_conf = mtu3_readl(mbase, U3D_DEVICE_CONF);
439 		dev_conf &= ~DEV_ADDR_MSK;
440 		dev_conf |= DEV_ADDR(mtu->address);
441 		mtu3_writel(mbase, U3D_DEVICE_CONF, dev_conf);
442 
443 		if (mtu->address)
444 			usb_gadget_set_state(&mtu->g, USB_STATE_ADDRESS);
445 		else
446 			usb_gadget_set_state(&mtu->g, USB_STATE_DEFAULT);
447 
448 		handled = 1;
449 		break;
450 	case USB_REQ_SET_CONFIGURATION:
451 		if (state == USB_STATE_ADDRESS) {
452 			usb_gadget_set_state(&mtu->g,
453 					USB_STATE_CONFIGURED);
454 		} else if (state == USB_STATE_CONFIGURED) {
455 			/*
456 			 * USB2 spec sec 9.4.7, if wValue is 0 then dev
457 			 * is moved to addressed state
458 			 */
459 			if (!value)
460 				usb_gadget_set_state(&mtu->g,
461 						USB_STATE_ADDRESS);
462 		}
463 		handled = 0;
464 		break;
465 	case USB_REQ_CLEAR_FEATURE:
466 		handled = ep0_handle_feature(mtu, setup, 0);
467 		break;
468 	case USB_REQ_SET_FEATURE:
469 		handled = ep0_handle_feature(mtu, setup, 1);
470 		break;
471 	case USB_REQ_GET_STATUS:
472 		handled = ep0_get_status(mtu, setup);
473 		break;
474 	case USB_REQ_SET_SEL:
475 		handled = ep0_set_sel(mtu, setup);
476 		break;
477 	case USB_REQ_SET_ISOCH_DELAY:
478 		handled = 1;
479 		break;
480 	default:
481 		/* delegate SET_CONFIGURATION, etc */
482 		handled = 0;
483 	}
484 
485 	return handled;
486 }
487 
488 /* receive an data packet (OUT) */
489 static void ep0_rx_state(struct mtu3 *mtu)
490 {
491 	struct mtu3_request *mreq;
492 	struct usb_request *req;
493 	void __iomem *mbase = mtu->mac_base;
494 	u32 maxp;
495 	u32 csr;
496 	u16 count = 0;
497 
498 	dev_dbg(mtu->dev, "%s\n", __func__);
499 
500 	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
501 	mreq = next_ep0_request(mtu);
502 	req = &mreq->request;
503 
504 	/* read packet and ack; or stall because of gadget driver bug */
505 	if (req) {
506 		void *buf = req->buf + req->actual;
507 		unsigned int len = req->length - req->actual;
508 
509 		/* read the buffer */
510 		count = mtu3_readl(mbase, U3D_RXCOUNT0);
511 		if (count > len) {
512 			req->status = -EOVERFLOW;
513 			count = len;
514 		}
515 		ep0_read_fifo(mtu->ep0, buf, count);
516 		req->actual += count;
517 		csr |= EP0_RXPKTRDY;
518 
519 		maxp = mtu->g.ep0->maxpacket;
520 		if (count < maxp || req->actual == req->length) {
521 			mtu->ep0_state = MU3D_EP0_STATE_SETUP;
522 			dev_dbg(mtu->dev, "ep0 state: %s\n",
523 				decode_ep0_state(mtu));
524 
525 			csr |= EP0_DATAEND;
526 		} else {
527 			req = NULL;
528 		}
529 	} else {
530 		csr |= EP0_RXPKTRDY | EP0_SENDSTALL;
531 		dev_dbg(mtu->dev, "%s: SENDSTALL\n", __func__);
532 	}
533 
534 	mtu3_writel(mbase, U3D_EP0CSR, csr);
535 
536 	/* give back the request if have received all data */
537 	if (req)
538 		ep0_req_giveback(mtu, req);
539 
540 }
541 
542 /* transmitting to the host (IN) */
543 static void ep0_tx_state(struct mtu3 *mtu)
544 {
545 	struct mtu3_request *mreq = next_ep0_request(mtu);
546 	struct usb_request *req;
547 	u32 csr;
548 	u8 *src;
549 	u8 count;
550 	u32 maxp;
551 
552 	dev_dbg(mtu->dev, "%s\n", __func__);
553 
554 	if (!mreq)
555 		return;
556 
557 	maxp = mtu->g.ep0->maxpacket;
558 	req = &mreq->request;
559 
560 	/* load the data */
561 	src = (u8 *)req->buf + req->actual;
562 	count = min(maxp, req->length - req->actual);
563 	if (count)
564 		ep0_write_fifo(mtu->ep0, src, count);
565 
566 	dev_dbg(mtu->dev, "%s act=%d, len=%d, cnt=%d, maxp=%d zero=%d\n",
567 		 __func__, req->actual, req->length, count, maxp, req->zero);
568 
569 	req->actual += count;
570 
571 	if ((count < maxp)
572 		|| ((req->actual == req->length) && !req->zero))
573 		mtu->ep0_state = MU3D_EP0_STATE_TX_END;
574 
575 	/* send it out, triggering a "txpktrdy cleared" irq */
576 	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
577 	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr | EP0_TXPKTRDY);
578 
579 	dev_dbg(mtu->dev, "%s ep0csr=0x%x\n", __func__,
580 		mtu3_readl(mtu->mac_base, U3D_EP0CSR));
581 }
582 
583 static void ep0_read_setup(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
584 {
585 	struct mtu3_request *mreq;
586 	u32 count;
587 	u32 csr;
588 
589 	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
590 	count = mtu3_readl(mtu->mac_base, U3D_RXCOUNT0);
591 
592 	ep0_read_fifo(mtu->ep0, (u8 *)setup, count);
593 
594 	dev_dbg(mtu->dev, "SETUP req%02x.%02x v%04x i%04x l%04x\n",
595 		 setup->bRequestType, setup->bRequest,
596 		 le16_to_cpu(setup->wValue), le16_to_cpu(setup->wIndex),
597 		 le16_to_cpu(setup->wLength));
598 
599 	/* clean up any leftover transfers */
600 	mreq = next_ep0_request(mtu);
601 	if (mreq)
602 		ep0_req_giveback(mtu, &mreq->request);
603 
604 	if (le16_to_cpu(setup->wLength) == 0) {
605 		;	/* no data stage, nothing to do */
606 	} else if (setup->bRequestType & USB_DIR_IN) {
607 		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
608 			csr | EP0_SETUPPKTRDY | EP0_DPHTX);
609 		mtu->ep0_state = MU3D_EP0_STATE_TX;
610 	} else {
611 		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
612 			(csr | EP0_SETUPPKTRDY) & (~EP0_DPHTX));
613 		mtu->ep0_state = MU3D_EP0_STATE_RX;
614 	}
615 }
616 
617 static int ep0_handle_setup(struct mtu3 *mtu)
618 __releases(mtu->lock)
619 __acquires(mtu->lock)
620 {
621 	struct usb_ctrlrequest setup;
622 	struct mtu3_request *mreq;
623 	void __iomem *mbase = mtu->mac_base;
624 	int handled = 0;
625 
626 	ep0_read_setup(mtu, &setup);
627 
628 	if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
629 		handled = handle_standard_request(mtu, &setup);
630 
631 	dev_dbg(mtu->dev, "handled %d, ep0_state: %s\n",
632 		 handled, decode_ep0_state(mtu));
633 
634 	if (handled < 0)
635 		goto stall;
636 	else if (handled > 0)
637 		goto finish;
638 
639 	handled = forward_to_driver(mtu, &setup);
640 	if (handled < 0) {
641 stall:
642 		dev_dbg(mtu->dev, "%s stall (%d)\n", __func__, handled);
643 
644 		ep0_stall_set(mtu->ep0, true,
645 			le16_to_cpu(setup.wLength) ? 0 : EP0_SETUPPKTRDY);
646 
647 		return 0;
648 	}
649 
650 finish:
651 	if (mtu->test_mode) {
652 		;	/* nothing to do */
653 	} else if (handled == USB_GADGET_DELAYED_STATUS) {
654 		/* handle the delay STATUS phase till receive ep_queue on ep0 */
655 		mtu->delayed_status = true;
656 	} else if (le16_to_cpu(setup.wLength) == 0) { /* no data stage */
657 
658 		mtu3_writel(mbase, U3D_EP0CSR,
659 			(mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS)
660 			| EP0_SETUPPKTRDY | EP0_DATAEND);
661 
662 		/* complete zlp request directly */
663 		mreq = next_ep0_request(mtu);
664 		if (mreq && !mreq->request.length)
665 			ep0_req_giveback(mtu, &mreq->request);
666 	}
667 
668 	return 0;
669 }
670 
671 irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu)
672 {
673 	void __iomem *mbase = mtu->mac_base;
674 	struct mtu3_request *mreq;
675 	u32 int_status;
676 	irqreturn_t ret = IRQ_NONE;
677 	u32 csr;
678 	u32 len;
679 
680 	int_status = mtu3_readl(mbase, U3D_EPISR);
681 	int_status &= mtu3_readl(mbase, U3D_EPIER);
682 	mtu3_writel(mbase, U3D_EPISR, int_status); /* W1C */
683 
684 	/* only handle ep0's */
685 	if (!(int_status & EP0ISR))
686 		return IRQ_NONE;
687 
688 	csr = mtu3_readl(mbase, U3D_EP0CSR);
689 
690 	dev_dbg(mtu->dev, "%s csr=0x%x\n", __func__, csr);
691 
692 	/* we sent a stall.. need to clear it now.. */
693 	if (csr & EP0_SENTSTALL) {
694 		ep0_stall_set(mtu->ep0, false, 0);
695 		csr = mtu3_readl(mbase, U3D_EP0CSR);
696 		ret = IRQ_HANDLED;
697 	}
698 	dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
699 
700 	switch (mtu->ep0_state) {
701 	case MU3D_EP0_STATE_TX:
702 		/* irq on clearing txpktrdy */
703 		if ((csr & EP0_FIFOFULL) == 0) {
704 			ep0_tx_state(mtu);
705 			ret = IRQ_HANDLED;
706 		}
707 		break;
708 	case MU3D_EP0_STATE_RX:
709 		/* irq on set rxpktrdy */
710 		if (csr & EP0_RXPKTRDY) {
711 			ep0_rx_state(mtu);
712 			ret = IRQ_HANDLED;
713 		}
714 		break;
715 	case MU3D_EP0_STATE_TX_END:
716 		mtu3_writel(mbase, U3D_EP0CSR,
717 			(csr & EP0_W1C_BITS) | EP0_DATAEND);
718 
719 		mreq = next_ep0_request(mtu);
720 		if (mreq)
721 			ep0_req_giveback(mtu, &mreq->request);
722 
723 		mtu->ep0_state = MU3D_EP0_STATE_SETUP;
724 		ret = IRQ_HANDLED;
725 		dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
726 		break;
727 	case MU3D_EP0_STATE_SETUP:
728 		if (!(csr & EP0_SETUPPKTRDY))
729 			break;
730 
731 		len = mtu3_readl(mbase, U3D_RXCOUNT0);
732 		if (len != 8) {
733 			dev_err(mtu->dev, "SETUP packet len %d != 8 ?\n", len);
734 			break;
735 		}
736 
737 		ep0_handle_setup(mtu);
738 		ret = IRQ_HANDLED;
739 		break;
740 	default:
741 		/* can't happen */
742 		ep0_stall_set(mtu->ep0, true, 0);
743 		WARN_ON(1);
744 		break;
745 	}
746 
747 	return ret;
748 }
749 
750 
751 static int mtu3_ep0_enable(struct usb_ep *ep,
752 	const struct usb_endpoint_descriptor *desc)
753 {
754 	/* always enabled */
755 	return -EINVAL;
756 }
757 
758 static int mtu3_ep0_disable(struct usb_ep *ep)
759 {
760 	/* always enabled */
761 	return -EINVAL;
762 }
763 
764 static int ep0_queue(struct mtu3_ep *mep, struct mtu3_request *mreq)
765 {
766 	struct mtu3 *mtu = mep->mtu;
767 
768 	mreq->mtu = mtu;
769 	mreq->request.actual = 0;
770 	mreq->request.status = -EINPROGRESS;
771 
772 	dev_dbg(mtu->dev, "%s %s (ep0_state: %s), len#%d\n", __func__,
773 		mep->name, decode_ep0_state(mtu), mreq->request.length);
774 
775 	switch (mtu->ep0_state) {
776 	case MU3D_EP0_STATE_SETUP:
777 	case MU3D_EP0_STATE_RX:	/* control-OUT data */
778 	case MU3D_EP0_STATE_TX:	/* control-IN data */
779 		break;
780 	default:
781 		dev_err(mtu->dev, "%s, error in ep0 state %s\n", __func__,
782 			decode_ep0_state(mtu));
783 		return -EINVAL;
784 	}
785 
786 	if (mtu->delayed_status) {
787 		u32 csr;
788 
789 		mtu->delayed_status = false;
790 		csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
791 		csr |= EP0_SETUPPKTRDY | EP0_DATAEND;
792 		mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
793 		/* needn't giveback the request for handling delay STATUS */
794 		return 0;
795 	}
796 
797 	if (!list_empty(&mep->req_list))
798 		return -EBUSY;
799 
800 	list_add_tail(&mreq->list, &mep->req_list);
801 
802 	/* sequence #1, IN ... start writing the data */
803 	if (mtu->ep0_state == MU3D_EP0_STATE_TX)
804 		ep0_tx_state(mtu);
805 
806 	return 0;
807 }
808 
809 static int mtu3_ep0_queue(struct usb_ep *ep,
810 	struct usb_request *req, gfp_t gfp)
811 {
812 	struct mtu3_ep *mep;
813 	struct mtu3_request *mreq;
814 	struct mtu3 *mtu;
815 	unsigned long flags;
816 	int ret = 0;
817 
818 	if (!ep || !req)
819 		return -EINVAL;
820 
821 	mep = to_mtu3_ep(ep);
822 	mtu = mep->mtu;
823 	mreq = to_mtu3_request(req);
824 
825 	spin_lock_irqsave(&mtu->lock, flags);
826 	ret = ep0_queue(mep, mreq);
827 	spin_unlock_irqrestore(&mtu->lock, flags);
828 	return ret;
829 }
830 
831 static int mtu3_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
832 {
833 	/* we just won't support this */
834 	return -EINVAL;
835 }
836 
837 static int mtu3_ep0_halt(struct usb_ep *ep, int value)
838 {
839 	struct mtu3_ep *mep;
840 	struct mtu3 *mtu;
841 	unsigned long flags;
842 	int ret = 0;
843 
844 	if (!ep || !value)
845 		return -EINVAL;
846 
847 	mep = to_mtu3_ep(ep);
848 	mtu = mep->mtu;
849 
850 	dev_dbg(mtu->dev, "%s\n", __func__);
851 
852 	spin_lock_irqsave(&mtu->lock, flags);
853 
854 	if (!list_empty(&mep->req_list)) {
855 		ret = -EBUSY;
856 		goto cleanup;
857 	}
858 
859 	switch (mtu->ep0_state) {
860 	/*
861 	 * stalls are usually issued after parsing SETUP packet, either
862 	 * directly in irq context from setup() or else later.
863 	 */
864 	case MU3D_EP0_STATE_TX:
865 	case MU3D_EP0_STATE_TX_END:
866 	case MU3D_EP0_STATE_RX:
867 	case MU3D_EP0_STATE_SETUP:
868 		ep0_stall_set(mtu->ep0, true, 0);
869 		break;
870 	default:
871 		dev_dbg(mtu->dev, "ep0 can't halt in state %s\n",
872 			decode_ep0_state(mtu));
873 		ret = -EINVAL;
874 	}
875 
876 cleanup:
877 	spin_unlock_irqrestore(&mtu->lock, flags);
878 	return ret;
879 }
880 
881 const struct usb_ep_ops mtu3_ep0_ops = {
882 	.enable = mtu3_ep0_enable,
883 	.disable = mtu3_ep0_disable,
884 	.alloc_request = mtu3_alloc_request,
885 	.free_request = mtu3_free_request,
886 	.queue = mtu3_ep0_queue,
887 	.dequeue = mtu3_ep0_dequeue,
888 	.set_halt = mtu3_ep0_halt,
889 };
890