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 
15 /* ep0 is always mtu3->in_eps[0] */
16 #define	next_ep0_request(mtu)	next_request((mtu)->ep0)
17 
18 /* for high speed test mode; see USB 2.0 spec 7.1.20 */
19 static const u8 mtu3_test_packet[53] = {
20 	/* implicit SYNC then DATA0 to start */
21 
22 	/* JKJKJKJK x9 */
23 	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
24 	/* JJKKJJKK x8 */
25 	0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa,
26 	/* JJJJKKKK x8 */
27 	0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee, 0xee,
28 	/* JJJJJJJKKKKKKK x8 */
29 	0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
30 	/* JJJJJJJK x8 */
31 	0x7f, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd,
32 	/* JKKKKKKK x10, JK */
33 	0xfc, 0x7e, 0xbf, 0xdf, 0xef, 0xf7, 0xfb, 0xfd, 0x7e,
34 	/* implicit CRC16 then EOP to end */
35 };
36 
37 static char *decode_ep0_state(struct mtu3 *mtu)
38 {
39 	switch (mtu->ep0_state) {
40 	case MU3D_EP0_STATE_SETUP:
41 		return "SETUP";
42 	case MU3D_EP0_STATE_TX:
43 		return "IN";
44 	case MU3D_EP0_STATE_RX:
45 		return "OUT";
46 	case MU3D_EP0_STATE_TX_END:
47 		return "TX-END";
48 	case MU3D_EP0_STATE_STALL:
49 		return "STALL";
50 	default:
51 		return "??";
52 	}
53 }
54 
55 static void ep0_req_giveback(struct mtu3 *mtu, struct usb_request *req)
56 {
57 	mtu3_req_complete(mtu->ep0, req, 0);
58 }
59 
60 static int
61 forward_to_driver(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
62 __releases(mtu->lock)
63 __acquires(mtu->lock)
64 {
65 	int ret;
66 
67 	if (!mtu->gadget_driver)
68 		return -EOPNOTSUPP;
69 
70 	spin_unlock(&mtu->lock);
71 	ret = mtu->gadget_driver->setup(&mtu->g, setup);
72 	spin_lock(&mtu->lock);
73 
74 	dev_dbg(mtu->dev, "%s ret %d\n", __func__, ret);
75 	return ret;
76 }
77 
78 static void ep0_write_fifo(struct mtu3_ep *mep, const u8 *src, u16 len)
79 {
80 	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
81 	u16 index = 0;
82 
83 	dev_dbg(mep->mtu->dev, "%s: ep%din, len=%d, buf=%p\n",
84 		__func__, mep->epnum, len, src);
85 
86 	if (len >= 4) {
87 		iowrite32_rep(fifo, src, len >> 2);
88 		index = len & ~0x03;
89 	}
90 	if (len & 0x02) {
91 		writew(*(u16 *)&src[index], fifo);
92 		index += 2;
93 	}
94 	if (len & 0x01)
95 		writeb(src[index], fifo);
96 }
97 
98 static void ep0_read_fifo(struct mtu3_ep *mep, u8 *dst, u16 len)
99 {
100 	void __iomem *fifo = mep->mtu->mac_base + U3D_FIFO0;
101 	u32 value;
102 	u16 index = 0;
103 
104 	dev_dbg(mep->mtu->dev, "%s: ep%dout len=%d buf=%p\n",
105 		 __func__, mep->epnum, len, dst);
106 
107 	if (len >= 4) {
108 		ioread32_rep(fifo, dst, len >> 2);
109 		index = len & ~0x03;
110 	}
111 	if (len & 0x3) {
112 		value = readl(fifo);
113 		memcpy(&dst[index], &value, len & 0x3);
114 	}
115 
116 }
117 
118 static void ep0_load_test_packet(struct mtu3 *mtu)
119 {
120 	/*
121 	 * because the length of test packet is less than max packet of HS ep0,
122 	 * write it into fifo directly.
123 	 */
124 	ep0_write_fifo(mtu->ep0, mtu3_test_packet, sizeof(mtu3_test_packet));
125 }
126 
127 /*
128  * A. send STALL for setup transfer without data stage:
129  *		set SENDSTALL and SETUPPKTRDY at the same time;
130  * B. send STALL for other cases:
131  *		set SENDSTALL only.
132  */
133 static void ep0_stall_set(struct mtu3_ep *mep0, bool set, u32 pktrdy)
134 {
135 	struct mtu3 *mtu = mep0->mtu;
136 	void __iomem *mbase = mtu->mac_base;
137 	u32 csr;
138 
139 	/* EP0_SENTSTALL is W1C */
140 	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
141 	if (set)
142 		csr |= EP0_SENDSTALL | pktrdy;
143 	else
144 		csr = (csr & ~EP0_SENDSTALL) | EP0_SENTSTALL;
145 	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
146 
147 	mtu->delayed_status = false;
148 	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
149 
150 	dev_dbg(mtu->dev, "ep0: %s STALL, ep0_state: %s\n",
151 		set ? "SEND" : "CLEAR", decode_ep0_state(mtu));
152 }
153 
154 static int ep0_queue(struct mtu3_ep *mep0, struct mtu3_request *mreq);
155 
156 static void ep0_dummy_complete(struct usb_ep *ep, struct usb_request *req)
157 {}
158 
159 static void ep0_set_sel_complete(struct usb_ep *ep, struct usb_request *req)
160 {
161 	struct mtu3_request *mreq;
162 	struct mtu3 *mtu;
163 	struct usb_set_sel_req sel;
164 
165 	memcpy(&sel, req->buf, sizeof(sel));
166 
167 	mreq = to_mtu3_request(req);
168 	mtu = mreq->mtu;
169 	dev_dbg(mtu->dev, "u1sel:%d, u1pel:%d, u2sel:%d, u2pel:%d\n",
170 		sel.u1_sel, sel.u1_pel, sel.u2_sel, sel.u2_pel);
171 }
172 
173 /* queue data stage to handle 6 byte SET_SEL request */
174 static int ep0_set_sel(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
175 {
176 	int ret;
177 	u16 length = le16_to_cpu(setup->wLength);
178 
179 	if (unlikely(length != 6)) {
180 		dev_err(mtu->dev, "%s wrong wLength:%d\n",
181 			__func__, length);
182 		return -EINVAL;
183 	}
184 
185 	mtu->ep0_req.mep = mtu->ep0;
186 	mtu->ep0_req.request.length = 6;
187 	mtu->ep0_req.request.buf = mtu->setup_buf;
188 	mtu->ep0_req.request.complete = ep0_set_sel_complete;
189 	ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
190 
191 	return ret < 0 ? ret : 1;
192 }
193 
194 static int
195 ep0_get_status(struct mtu3 *mtu, const struct usb_ctrlrequest *setup)
196 {
197 	struct mtu3_ep *mep = NULL;
198 	int handled = 1;
199 	u8 result[2] = {0, 0};
200 	u8 epnum = 0;
201 	int is_in;
202 
203 	switch (setup->bRequestType & USB_RECIP_MASK) {
204 	case USB_RECIP_DEVICE:
205 		result[0] = mtu->is_self_powered << USB_DEVICE_SELF_POWERED;
206 		result[0] |= mtu->may_wakeup << USB_DEVICE_REMOTE_WAKEUP;
207 
208 		if (mtu->g.speed >= USB_SPEED_SUPER) {
209 			result[0] |= mtu->u1_enable << USB_DEV_STAT_U1_ENABLED;
210 			result[0] |= mtu->u2_enable << USB_DEV_STAT_U2_ENABLED;
211 		}
212 
213 		dev_dbg(mtu->dev, "%s result=%x, U1=%x, U2=%x\n", __func__,
214 			result[0], mtu->u1_enable, mtu->u2_enable);
215 
216 		break;
217 	case USB_RECIP_INTERFACE:
218 		break;
219 	case USB_RECIP_ENDPOINT:
220 		epnum = (u8) le16_to_cpu(setup->wIndex);
221 		is_in = epnum & USB_DIR_IN;
222 		epnum &= USB_ENDPOINT_NUMBER_MASK;
223 
224 		if (epnum >= mtu->num_eps) {
225 			handled = -EINVAL;
226 			break;
227 		}
228 		if (!epnum)
229 			break;
230 
231 		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
232 		if (!mep->desc) {
233 			handled = -EINVAL;
234 			break;
235 		}
236 		if (mep->flags & MTU3_EP_STALL)
237 			result[0] |= 1 << USB_ENDPOINT_HALT;
238 
239 		break;
240 	default:
241 		/* class, vendor, etc ... delegate */
242 		handled = 0;
243 		break;
244 	}
245 
246 	if (handled > 0) {
247 		int ret;
248 
249 		/* prepare a data stage for GET_STATUS */
250 		dev_dbg(mtu->dev, "get_status=%x\n", *(u16 *)result);
251 		memcpy(mtu->setup_buf, result, sizeof(result));
252 		mtu->ep0_req.mep = mtu->ep0;
253 		mtu->ep0_req.request.length = 2;
254 		mtu->ep0_req.request.buf = &mtu->setup_buf;
255 		mtu->ep0_req.request.complete = ep0_dummy_complete;
256 		ret = ep0_queue(mtu->ep0, &mtu->ep0_req);
257 		if (ret < 0)
258 			handled = ret;
259 	}
260 	return handled;
261 }
262 
263 static int handle_test_mode(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
264 {
265 	void __iomem *mbase = mtu->mac_base;
266 	int handled = 1;
267 	u32 value;
268 
269 	switch (le16_to_cpu(setup->wIndex) >> 8) {
270 	case TEST_J:
271 		dev_dbg(mtu->dev, "TEST_J\n");
272 		mtu->test_mode_nr = TEST_J_MODE;
273 		break;
274 	case TEST_K:
275 		dev_dbg(mtu->dev, "TEST_K\n");
276 		mtu->test_mode_nr = TEST_K_MODE;
277 		break;
278 	case TEST_SE0_NAK:
279 		dev_dbg(mtu->dev, "TEST_SE0_NAK\n");
280 		mtu->test_mode_nr = TEST_SE0_NAK_MODE;
281 		break;
282 	case TEST_PACKET:
283 		dev_dbg(mtu->dev, "TEST_PACKET\n");
284 		mtu->test_mode_nr = TEST_PACKET_MODE;
285 		break;
286 	default:
287 		handled = -EINVAL;
288 		goto out;
289 	}
290 
291 	mtu->test_mode = true;
292 
293 	/* no TX completion interrupt, and need restart platform after test */
294 	if (mtu->test_mode_nr == TEST_PACKET_MODE)
295 		ep0_load_test_packet(mtu);
296 
297 	/* send status before entering test mode. */
298 	value = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
299 	mtu3_writel(mbase, U3D_EP0CSR, value | EP0_SETUPPKTRDY | EP0_DATAEND);
300 
301 	/* wait for ACK status sent by host */
302 	readl_poll_timeout_atomic(mbase + U3D_EP0CSR, value,
303 			!(value & EP0_DATAEND), 100, 5000);
304 
305 	mtu3_writel(mbase, U3D_USB2_TEST_MODE, mtu->test_mode_nr);
306 
307 	mtu->ep0_state = MU3D_EP0_STATE_SETUP;
308 
309 out:
310 	return handled;
311 }
312 
313 static int ep0_handle_feature_dev(struct mtu3 *mtu,
314 		struct usb_ctrlrequest *setup, bool set)
315 {
316 	void __iomem *mbase = mtu->mac_base;
317 	int handled = -EINVAL;
318 	u32 lpc;
319 
320 	switch (le16_to_cpu(setup->wValue)) {
321 	case USB_DEVICE_REMOTE_WAKEUP:
322 		mtu->may_wakeup = !!set;
323 		handled = 1;
324 		break;
325 	case USB_DEVICE_TEST_MODE:
326 		if (!set || (mtu->g.speed != USB_SPEED_HIGH) ||
327 			(le16_to_cpu(setup->wIndex) & 0xff))
328 			break;
329 
330 		handled = handle_test_mode(mtu, setup);
331 		break;
332 	case USB_DEVICE_U1_ENABLE:
333 		if (mtu->g.speed < USB_SPEED_SUPER ||
334 		    mtu->g.state != USB_STATE_CONFIGURED)
335 			break;
336 
337 		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
338 		if (set)
339 			lpc |= SW_U1_ACCEPT_ENABLE;
340 		else
341 			lpc &= ~SW_U1_ACCEPT_ENABLE;
342 		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
343 
344 		mtu->u1_enable = !!set;
345 		handled = 1;
346 		break;
347 	case USB_DEVICE_U2_ENABLE:
348 		if (mtu->g.speed < USB_SPEED_SUPER ||
349 		    mtu->g.state != USB_STATE_CONFIGURED)
350 			break;
351 
352 		lpc = mtu3_readl(mbase, U3D_LINK_POWER_CONTROL);
353 		if (set)
354 			lpc |= SW_U2_ACCEPT_ENABLE;
355 		else
356 			lpc &= ~SW_U2_ACCEPT_ENABLE;
357 		mtu3_writel(mbase, U3D_LINK_POWER_CONTROL, lpc);
358 
359 		mtu->u2_enable = !!set;
360 		handled = 1;
361 		break;
362 	default:
363 		handled = -EINVAL;
364 		break;
365 	}
366 	return handled;
367 }
368 
369 static int ep0_handle_feature(struct mtu3 *mtu,
370 		struct usb_ctrlrequest *setup, bool set)
371 {
372 	struct mtu3_ep *mep;
373 	int handled = -EINVAL;
374 	int is_in;
375 	u16 value;
376 	u16 index;
377 	u8 epnum;
378 
379 	value = le16_to_cpu(setup->wValue);
380 	index = le16_to_cpu(setup->wIndex);
381 
382 	switch (setup->bRequestType & USB_RECIP_MASK) {
383 	case USB_RECIP_DEVICE:
384 		handled = ep0_handle_feature_dev(mtu, setup, set);
385 		break;
386 	case USB_RECIP_INTERFACE:
387 		/* superspeed only */
388 		if (value == USB_INTRF_FUNC_SUSPEND &&
389 		    mtu->g.speed >= USB_SPEED_SUPER) {
390 			/*
391 			 * forward the request because function drivers
392 			 * should handle it
393 			 */
394 			handled = 0;
395 		}
396 		break;
397 	case USB_RECIP_ENDPOINT:
398 		epnum = index & USB_ENDPOINT_NUMBER_MASK;
399 		if (epnum == 0 || epnum >= mtu->num_eps ||
400 			value != USB_ENDPOINT_HALT)
401 			break;
402 
403 		is_in = index & USB_DIR_IN;
404 		mep = (is_in ? mtu->in_eps : mtu->out_eps) + epnum;
405 		if (!mep->desc)
406 			break;
407 
408 		handled = 1;
409 		/* ignore request if endpoint is wedged */
410 		if (mep->wedged)
411 			break;
412 
413 		mtu3_ep_stall_set(mep, set);
414 		break;
415 	default:
416 		/* class, vendor, etc ... delegate */
417 		handled = 0;
418 		break;
419 	}
420 	return handled;
421 }
422 
423 /*
424  * handle all control requests can be handled
425  * returns:
426  *	negative errno - error happened
427  *	zero - need delegate SETUP to gadget driver
428  *	positive - already handled
429  */
430 static int handle_standard_request(struct mtu3 *mtu,
431 			  struct usb_ctrlrequest *setup)
432 {
433 	void __iomem *mbase = mtu->mac_base;
434 	enum usb_device_state state = mtu->g.state;
435 	int handled = -EINVAL;
436 	u32 dev_conf;
437 	u16 value;
438 
439 	value = le16_to_cpu(setup->wValue);
440 
441 	/* the gadget driver handles everything except what we must handle */
442 	switch (setup->bRequest) {
443 	case USB_REQ_SET_ADDRESS:
444 		/* change it after the status stage */
445 		mtu->address = (u8) (value & 0x7f);
446 		dev_dbg(mtu->dev, "set address to 0x%x\n", mtu->address);
447 
448 		dev_conf = mtu3_readl(mbase, U3D_DEVICE_CONF);
449 		dev_conf &= ~DEV_ADDR_MSK;
450 		dev_conf |= DEV_ADDR(mtu->address);
451 		mtu3_writel(mbase, U3D_DEVICE_CONF, dev_conf);
452 
453 		if (mtu->address)
454 			usb_gadget_set_state(&mtu->g, USB_STATE_ADDRESS);
455 		else
456 			usb_gadget_set_state(&mtu->g, USB_STATE_DEFAULT);
457 
458 		handled = 1;
459 		break;
460 	case USB_REQ_SET_CONFIGURATION:
461 		if (state == USB_STATE_ADDRESS) {
462 			usb_gadget_set_state(&mtu->g,
463 					USB_STATE_CONFIGURED);
464 		} else if (state == USB_STATE_CONFIGURED) {
465 			/*
466 			 * USB2 spec sec 9.4.7, if wValue is 0 then dev
467 			 * is moved to addressed state
468 			 */
469 			if (!value)
470 				usb_gadget_set_state(&mtu->g,
471 						USB_STATE_ADDRESS);
472 		}
473 		handled = 0;
474 		break;
475 	case USB_REQ_CLEAR_FEATURE:
476 		handled = ep0_handle_feature(mtu, setup, 0);
477 		break;
478 	case USB_REQ_SET_FEATURE:
479 		handled = ep0_handle_feature(mtu, setup, 1);
480 		break;
481 	case USB_REQ_GET_STATUS:
482 		handled = ep0_get_status(mtu, setup);
483 		break;
484 	case USB_REQ_SET_SEL:
485 		handled = ep0_set_sel(mtu, setup);
486 		break;
487 	case USB_REQ_SET_ISOCH_DELAY:
488 		handled = 1;
489 		break;
490 	default:
491 		/* delegate SET_CONFIGURATION, etc */
492 		handled = 0;
493 	}
494 
495 	return handled;
496 }
497 
498 /* receive an data packet (OUT) */
499 static void ep0_rx_state(struct mtu3 *mtu)
500 {
501 	struct mtu3_request *mreq;
502 	struct usb_request *req;
503 	void __iomem *mbase = mtu->mac_base;
504 	u32 maxp;
505 	u32 csr;
506 	u16 count = 0;
507 
508 	dev_dbg(mtu->dev, "%s\n", __func__);
509 
510 	csr = mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS;
511 	mreq = next_ep0_request(mtu);
512 	req = &mreq->request;
513 
514 	/* read packet and ack; or stall because of gadget driver bug */
515 	if (req) {
516 		void *buf = req->buf + req->actual;
517 		unsigned int len = req->length - req->actual;
518 
519 		/* read the buffer */
520 		count = mtu3_readl(mbase, U3D_RXCOUNT0);
521 		if (count > len) {
522 			req->status = -EOVERFLOW;
523 			count = len;
524 		}
525 		ep0_read_fifo(mtu->ep0, buf, count);
526 		req->actual += count;
527 		csr |= EP0_RXPKTRDY;
528 
529 		maxp = mtu->g.ep0->maxpacket;
530 		if (count < maxp || req->actual == req->length) {
531 			mtu->ep0_state = MU3D_EP0_STATE_SETUP;
532 			dev_dbg(mtu->dev, "ep0 state: %s\n",
533 				decode_ep0_state(mtu));
534 
535 			csr |= EP0_DATAEND;
536 		} else {
537 			req = NULL;
538 		}
539 	} else {
540 		csr |= EP0_RXPKTRDY | EP0_SENDSTALL;
541 		dev_dbg(mtu->dev, "%s: SENDSTALL\n", __func__);
542 	}
543 
544 	mtu3_writel(mbase, U3D_EP0CSR, csr);
545 
546 	/* give back the request if have received all data */
547 	if (req)
548 		ep0_req_giveback(mtu, req);
549 
550 }
551 
552 /* transmitting to the host (IN) */
553 static void ep0_tx_state(struct mtu3 *mtu)
554 {
555 	struct mtu3_request *mreq = next_ep0_request(mtu);
556 	struct usb_request *req;
557 	u32 csr;
558 	u8 *src;
559 	u32 count;
560 	u32 maxp;
561 
562 	dev_dbg(mtu->dev, "%s\n", __func__);
563 
564 	if (!mreq)
565 		return;
566 
567 	maxp = mtu->g.ep0->maxpacket;
568 	req = &mreq->request;
569 
570 	/* load the data */
571 	src = (u8 *)req->buf + req->actual;
572 	count = min(maxp, req->length - req->actual);
573 	if (count)
574 		ep0_write_fifo(mtu->ep0, src, count);
575 
576 	dev_dbg(mtu->dev, "%s act=%d, len=%d, cnt=%d, maxp=%d zero=%d\n",
577 		 __func__, req->actual, req->length, count, maxp, req->zero);
578 
579 	req->actual += count;
580 
581 	if ((count < maxp)
582 		|| ((req->actual == req->length) && !req->zero))
583 		mtu->ep0_state = MU3D_EP0_STATE_TX_END;
584 
585 	/* send it out, triggering a "txpktrdy cleared" irq */
586 	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
587 	mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr | EP0_TXPKTRDY);
588 
589 	dev_dbg(mtu->dev, "%s ep0csr=0x%x\n", __func__,
590 		mtu3_readl(mtu->mac_base, U3D_EP0CSR));
591 }
592 
593 static void ep0_read_setup(struct mtu3 *mtu, struct usb_ctrlrequest *setup)
594 {
595 	struct mtu3_request *mreq;
596 	u32 count;
597 	u32 csr;
598 
599 	csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
600 	count = mtu3_readl(mtu->mac_base, U3D_RXCOUNT0);
601 
602 	ep0_read_fifo(mtu->ep0, (u8 *)setup, count);
603 
604 	dev_dbg(mtu->dev, "SETUP req%02x.%02x v%04x i%04x l%04x\n",
605 		 setup->bRequestType, setup->bRequest,
606 		 le16_to_cpu(setup->wValue), le16_to_cpu(setup->wIndex),
607 		 le16_to_cpu(setup->wLength));
608 
609 	/* clean up any leftover transfers */
610 	mreq = next_ep0_request(mtu);
611 	if (mreq)
612 		ep0_req_giveback(mtu, &mreq->request);
613 
614 	if (le16_to_cpu(setup->wLength) == 0) {
615 		;	/* no data stage, nothing to do */
616 	} else if (setup->bRequestType & USB_DIR_IN) {
617 		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
618 			csr | EP0_SETUPPKTRDY | EP0_DPHTX);
619 		mtu->ep0_state = MU3D_EP0_STATE_TX;
620 	} else {
621 		mtu3_writel(mtu->mac_base, U3D_EP0CSR,
622 			(csr | EP0_SETUPPKTRDY) & (~EP0_DPHTX));
623 		mtu->ep0_state = MU3D_EP0_STATE_RX;
624 	}
625 }
626 
627 static int ep0_handle_setup(struct mtu3 *mtu)
628 __releases(mtu->lock)
629 __acquires(mtu->lock)
630 {
631 	struct usb_ctrlrequest setup;
632 	struct mtu3_request *mreq;
633 	void __iomem *mbase = mtu->mac_base;
634 	int handled = 0;
635 
636 	ep0_read_setup(mtu, &setup);
637 
638 	if ((setup.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
639 		handled = handle_standard_request(mtu, &setup);
640 
641 	dev_dbg(mtu->dev, "handled %d, ep0_state: %s\n",
642 		 handled, decode_ep0_state(mtu));
643 
644 	if (handled < 0)
645 		goto stall;
646 	else if (handled > 0)
647 		goto finish;
648 
649 	handled = forward_to_driver(mtu, &setup);
650 	if (handled < 0) {
651 stall:
652 		dev_dbg(mtu->dev, "%s stall (%d)\n", __func__, handled);
653 
654 		ep0_stall_set(mtu->ep0, true,
655 			le16_to_cpu(setup.wLength) ? 0 : EP0_SETUPPKTRDY);
656 
657 		return 0;
658 	}
659 
660 finish:
661 	if (mtu->test_mode) {
662 		;	/* nothing to do */
663 	} else if (handled == USB_GADGET_DELAYED_STATUS) {
664 		/* handle the delay STATUS phase till receive ep_queue on ep0 */
665 		mtu->delayed_status = true;
666 	} else if (le16_to_cpu(setup.wLength) == 0) { /* no data stage */
667 
668 		mtu3_writel(mbase, U3D_EP0CSR,
669 			(mtu3_readl(mbase, U3D_EP0CSR) & EP0_W1C_BITS)
670 			| EP0_SETUPPKTRDY | EP0_DATAEND);
671 
672 		/* complete zlp request directly */
673 		mreq = next_ep0_request(mtu);
674 		if (mreq && !mreq->request.length)
675 			ep0_req_giveback(mtu, &mreq->request);
676 	}
677 
678 	return 0;
679 }
680 
681 irqreturn_t mtu3_ep0_isr(struct mtu3 *mtu)
682 {
683 	void __iomem *mbase = mtu->mac_base;
684 	struct mtu3_request *mreq;
685 	u32 int_status;
686 	irqreturn_t ret = IRQ_NONE;
687 	u32 csr;
688 	u32 len;
689 
690 	int_status = mtu3_readl(mbase, U3D_EPISR);
691 	int_status &= mtu3_readl(mbase, U3D_EPIER);
692 	mtu3_writel(mbase, U3D_EPISR, int_status); /* W1C */
693 
694 	/* only handle ep0's */
695 	if (!(int_status & EP0ISR))
696 		return IRQ_NONE;
697 
698 	csr = mtu3_readl(mbase, U3D_EP0CSR);
699 
700 	dev_dbg(mtu->dev, "%s csr=0x%x\n", __func__, csr);
701 
702 	/* we sent a stall.. need to clear it now.. */
703 	if (csr & EP0_SENTSTALL) {
704 		ep0_stall_set(mtu->ep0, false, 0);
705 		csr = mtu3_readl(mbase, U3D_EP0CSR);
706 		ret = IRQ_HANDLED;
707 	}
708 	dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
709 
710 	switch (mtu->ep0_state) {
711 	case MU3D_EP0_STATE_TX:
712 		/* irq on clearing txpktrdy */
713 		if ((csr & EP0_FIFOFULL) == 0) {
714 			ep0_tx_state(mtu);
715 			ret = IRQ_HANDLED;
716 		}
717 		break;
718 	case MU3D_EP0_STATE_RX:
719 		/* irq on set rxpktrdy */
720 		if (csr & EP0_RXPKTRDY) {
721 			ep0_rx_state(mtu);
722 			ret = IRQ_HANDLED;
723 		}
724 		break;
725 	case MU3D_EP0_STATE_TX_END:
726 		mtu3_writel(mbase, U3D_EP0CSR,
727 			(csr & EP0_W1C_BITS) | EP0_DATAEND);
728 
729 		mreq = next_ep0_request(mtu);
730 		if (mreq)
731 			ep0_req_giveback(mtu, &mreq->request);
732 
733 		mtu->ep0_state = MU3D_EP0_STATE_SETUP;
734 		ret = IRQ_HANDLED;
735 		dev_dbg(mtu->dev, "ep0_state: %s\n", decode_ep0_state(mtu));
736 		break;
737 	case MU3D_EP0_STATE_SETUP:
738 		if (!(csr & EP0_SETUPPKTRDY))
739 			break;
740 
741 		len = mtu3_readl(mbase, U3D_RXCOUNT0);
742 		if (len != 8) {
743 			dev_err(mtu->dev, "SETUP packet len %d != 8 ?\n", len);
744 			break;
745 		}
746 
747 		ep0_handle_setup(mtu);
748 		ret = IRQ_HANDLED;
749 		break;
750 	default:
751 		/* can't happen */
752 		ep0_stall_set(mtu->ep0, true, 0);
753 		WARN_ON(1);
754 		break;
755 	}
756 
757 	return ret;
758 }
759 
760 
761 static int mtu3_ep0_enable(struct usb_ep *ep,
762 	const struct usb_endpoint_descriptor *desc)
763 {
764 	/* always enabled */
765 	return -EINVAL;
766 }
767 
768 static int mtu3_ep0_disable(struct usb_ep *ep)
769 {
770 	/* always enabled */
771 	return -EINVAL;
772 }
773 
774 static int ep0_queue(struct mtu3_ep *mep, struct mtu3_request *mreq)
775 {
776 	struct mtu3 *mtu = mep->mtu;
777 
778 	mreq->mtu = mtu;
779 	mreq->request.actual = 0;
780 	mreq->request.status = -EINPROGRESS;
781 
782 	dev_dbg(mtu->dev, "%s %s (ep0_state: %s), len#%d\n", __func__,
783 		mep->name, decode_ep0_state(mtu), mreq->request.length);
784 
785 	switch (mtu->ep0_state) {
786 	case MU3D_EP0_STATE_SETUP:
787 	case MU3D_EP0_STATE_RX:	/* control-OUT data */
788 	case MU3D_EP0_STATE_TX:	/* control-IN data */
789 		break;
790 	default:
791 		dev_err(mtu->dev, "%s, error in ep0 state %s\n", __func__,
792 			decode_ep0_state(mtu));
793 		return -EINVAL;
794 	}
795 
796 	if (mtu->delayed_status) {
797 		u32 csr;
798 
799 		mtu->delayed_status = false;
800 		csr = mtu3_readl(mtu->mac_base, U3D_EP0CSR) & EP0_W1C_BITS;
801 		csr |= EP0_SETUPPKTRDY | EP0_DATAEND;
802 		mtu3_writel(mtu->mac_base, U3D_EP0CSR, csr);
803 		/* needn't giveback the request for handling delay STATUS */
804 		return 0;
805 	}
806 
807 	if (!list_empty(&mep->req_list))
808 		return -EBUSY;
809 
810 	list_add_tail(&mreq->list, &mep->req_list);
811 
812 	/* sequence #1, IN ... start writing the data */
813 	if (mtu->ep0_state == MU3D_EP0_STATE_TX)
814 		ep0_tx_state(mtu);
815 
816 	return 0;
817 }
818 
819 static int mtu3_ep0_queue(struct usb_ep *ep,
820 	struct usb_request *req, gfp_t gfp)
821 {
822 	struct mtu3_ep *mep;
823 	struct mtu3_request *mreq;
824 	struct mtu3 *mtu;
825 	unsigned long flags;
826 	int ret = 0;
827 
828 	if (!ep || !req)
829 		return -EINVAL;
830 
831 	mep = to_mtu3_ep(ep);
832 	mtu = mep->mtu;
833 	mreq = to_mtu3_request(req);
834 
835 	spin_lock_irqsave(&mtu->lock, flags);
836 	ret = ep0_queue(mep, mreq);
837 	spin_unlock_irqrestore(&mtu->lock, flags);
838 	return ret;
839 }
840 
841 static int mtu3_ep0_dequeue(struct usb_ep *ep, struct usb_request *req)
842 {
843 	/* we just won't support this */
844 	return -EINVAL;
845 }
846 
847 static int mtu3_ep0_halt(struct usb_ep *ep, int value)
848 {
849 	struct mtu3_ep *mep;
850 	struct mtu3 *mtu;
851 	unsigned long flags;
852 	int ret = 0;
853 
854 	if (!ep || !value)
855 		return -EINVAL;
856 
857 	mep = to_mtu3_ep(ep);
858 	mtu = mep->mtu;
859 
860 	dev_dbg(mtu->dev, "%s\n", __func__);
861 
862 	spin_lock_irqsave(&mtu->lock, flags);
863 
864 	if (!list_empty(&mep->req_list)) {
865 		ret = -EBUSY;
866 		goto cleanup;
867 	}
868 
869 	switch (mtu->ep0_state) {
870 	/*
871 	 * stalls are usually issued after parsing SETUP packet, either
872 	 * directly in irq context from setup() or else later.
873 	 */
874 	case MU3D_EP0_STATE_TX:
875 	case MU3D_EP0_STATE_TX_END:
876 	case MU3D_EP0_STATE_RX:
877 	case MU3D_EP0_STATE_SETUP:
878 		ep0_stall_set(mtu->ep0, true, 0);
879 		break;
880 	default:
881 		dev_dbg(mtu->dev, "ep0 can't halt in state %s\n",
882 			decode_ep0_state(mtu));
883 		ret = -EINVAL;
884 	}
885 
886 cleanup:
887 	spin_unlock_irqrestore(&mtu->lock, flags);
888 	return ret;
889 }
890 
891 const struct usb_ep_ops mtu3_ep0_ops = {
892 	.enable = mtu3_ep0_enable,
893 	.disable = mtu3_ep0_disable,
894 	.alloc_request = mtu3_alloc_request,
895 	.free_request = mtu3_free_request,
896 	.queue = mtu3_ep0_queue,
897 	.dequeue = mtu3_ep0_dequeue,
898 	.set_halt = mtu3_ep0_halt,
899 };
900