xref: /linux/drivers/usb/isp1760/isp1760-udc.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  * Driver for the NXP ISP1761 device controller
3  *
4  * Copyright 2014 Ideas on Board Oy
5  *
6  * Contacts:
7  *	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * version 2 as published by the Free Software Foundation.
12  */
13 
14 #include <linux/interrupt.h>
15 #include <linux/io.h>
16 #include <linux/kernel.h>
17 #include <linux/list.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/timer.h>
21 #include <linux/usb.h>
22 
23 #include "isp1760-core.h"
24 #include "isp1760-regs.h"
25 #include "isp1760-udc.h"
26 
27 #define ISP1760_VBUS_POLL_INTERVAL	msecs_to_jiffies(500)
28 
29 struct isp1760_request {
30 	struct usb_request req;
31 	struct list_head queue;
32 	struct isp1760_ep *ep;
33 	unsigned int packet_size;
34 };
35 
36 static inline struct isp1760_udc *gadget_to_udc(struct usb_gadget *gadget)
37 {
38 	return container_of(gadget, struct isp1760_udc, gadget);
39 }
40 
41 static inline struct isp1760_ep *ep_to_udc_ep(struct usb_ep *ep)
42 {
43 	return container_of(ep, struct isp1760_ep, ep);
44 }
45 
46 static inline struct isp1760_request *req_to_udc_req(struct usb_request *req)
47 {
48 	return container_of(req, struct isp1760_request, req);
49 }
50 
51 static inline u32 isp1760_udc_read(struct isp1760_udc *udc, u16 reg)
52 {
53 	return isp1760_read32(udc->regs, reg);
54 }
55 
56 static inline void isp1760_udc_write(struct isp1760_udc *udc, u16 reg, u32 val)
57 {
58 	isp1760_write32(udc->regs, reg, val);
59 }
60 
61 /* -----------------------------------------------------------------------------
62  * Endpoint Management
63  */
64 
65 static struct isp1760_ep *isp1760_udc_find_ep(struct isp1760_udc *udc,
66 					      u16 index)
67 {
68 	unsigned int i;
69 
70 	if (index == 0)
71 		return &udc->ep[0];
72 
73 	for (i = 1; i < ARRAY_SIZE(udc->ep); ++i) {
74 		if (udc->ep[i].addr == index)
75 			return udc->ep[i].desc ? &udc->ep[i] : NULL;
76 	}
77 
78 	return NULL;
79 }
80 
81 static void __isp1760_udc_select_ep(struct isp1760_ep *ep, int dir)
82 {
83 	isp1760_udc_write(ep->udc, DC_EPINDEX,
84 			  DC_ENDPIDX(ep->addr & USB_ENDPOINT_NUMBER_MASK) |
85 			  (dir == USB_DIR_IN ? DC_EPDIR : 0));
86 }
87 
88 /**
89  * isp1760_udc_select_ep - Select an endpoint for register access
90  * @ep: The endpoint
91  *
92  * The ISP1761 endpoint registers are banked. This function selects the target
93  * endpoint for banked register access. The selection remains valid until the
94  * next call to this function, the next direct access to the EPINDEX register
95  * or the next reset, whichever comes first.
96  *
97  * Called with the UDC spinlock held.
98  */
99 static void isp1760_udc_select_ep(struct isp1760_ep *ep)
100 {
101 	__isp1760_udc_select_ep(ep, ep->addr & USB_ENDPOINT_DIR_MASK);
102 }
103 
104 /* Called with the UDC spinlock held. */
105 static void isp1760_udc_ctrl_send_status(struct isp1760_ep *ep, int dir)
106 {
107 	struct isp1760_udc *udc = ep->udc;
108 
109 	/*
110 	 * Proceed to the status stage. The status stage data packet flows in
111 	 * the direction opposite to the data stage data packets, we thus need
112 	 * to select the OUT/IN endpoint for IN/OUT transfers.
113 	 */
114 	isp1760_udc_write(udc, DC_EPINDEX, DC_ENDPIDX(0) |
115 			  (dir == USB_DIR_IN ? 0 : DC_EPDIR));
116 	isp1760_udc_write(udc, DC_CTRLFUNC, DC_STATUS);
117 
118 	/*
119 	 * The hardware will terminate the request automatically and go back to
120 	 * the setup stage without notifying us.
121 	 */
122 	udc->ep0_state = ISP1760_CTRL_SETUP;
123 }
124 
125 /* Called without the UDC spinlock held. */
126 static void isp1760_udc_request_complete(struct isp1760_ep *ep,
127 					 struct isp1760_request *req,
128 					 int status)
129 {
130 	struct isp1760_udc *udc = ep->udc;
131 	unsigned long flags;
132 
133 	dev_dbg(ep->udc->isp->dev, "completing request %p with status %d\n",
134 		req, status);
135 
136 	req->ep = NULL;
137 	req->req.status = status;
138 	req->req.complete(&ep->ep, &req->req);
139 
140 	spin_lock_irqsave(&udc->lock, flags);
141 
142 	/*
143 	 * When completing control OUT requests, move to the status stage after
144 	 * calling the request complete callback. This gives the gadget an
145 	 * opportunity to stall the control transfer if needed.
146 	 */
147 	if (status == 0 && ep->addr == 0 && udc->ep0_dir == USB_DIR_OUT)
148 		isp1760_udc_ctrl_send_status(ep, USB_DIR_OUT);
149 
150 	spin_unlock_irqrestore(&udc->lock, flags);
151 }
152 
153 static void isp1760_udc_ctrl_send_stall(struct isp1760_ep *ep)
154 {
155 	struct isp1760_udc *udc = ep->udc;
156 	unsigned long flags;
157 
158 	dev_dbg(ep->udc->isp->dev, "%s(ep%02x)\n", __func__, ep->addr);
159 
160 	spin_lock_irqsave(&udc->lock, flags);
161 
162 	/* Stall both the IN and OUT endpoints. */
163 	__isp1760_udc_select_ep(ep, USB_DIR_OUT);
164 	isp1760_udc_write(udc, DC_CTRLFUNC, DC_STALL);
165 	__isp1760_udc_select_ep(ep, USB_DIR_IN);
166 	isp1760_udc_write(udc, DC_CTRLFUNC, DC_STALL);
167 
168 	/* A protocol stall completes the control transaction. */
169 	udc->ep0_state = ISP1760_CTRL_SETUP;
170 
171 	spin_unlock_irqrestore(&udc->lock, flags);
172 }
173 
174 /* -----------------------------------------------------------------------------
175  * Data Endpoints
176  */
177 
178 /* Called with the UDC spinlock held. */
179 static bool isp1760_udc_receive(struct isp1760_ep *ep,
180 				struct isp1760_request *req)
181 {
182 	struct isp1760_udc *udc = ep->udc;
183 	unsigned int len;
184 	u32 *buf;
185 	int i;
186 
187 	isp1760_udc_select_ep(ep);
188 	len = isp1760_udc_read(udc, DC_BUFLEN) & DC_DATACOUNT_MASK;
189 
190 	dev_dbg(udc->isp->dev, "%s: received %u bytes (%u/%u done)\n",
191 		__func__, len, req->req.actual, req->req.length);
192 
193 	len = min(len, req->req.length - req->req.actual);
194 
195 	if (!len) {
196 		/*
197 		 * There's no data to be read from the FIFO, acknowledge the RX
198 		 * interrupt by clearing the buffer.
199 		 *
200 		 * TODO: What if another packet arrives in the meantime ? The
201 		 * datasheet doesn't clearly document how this should be
202 		 * handled.
203 		 */
204 		isp1760_udc_write(udc, DC_CTRLFUNC, DC_CLBUF);
205 		return false;
206 	}
207 
208 	buf = req->req.buf + req->req.actual;
209 
210 	/*
211 	 * Make sure not to read more than one extra byte, otherwise data from
212 	 * the next packet might be removed from the FIFO.
213 	 */
214 	for (i = len; i > 2; i -= 4, ++buf)
215 		*buf = le32_to_cpu(isp1760_udc_read(udc, DC_DATAPORT));
216 	if (i > 0)
217 		*(u16 *)buf = le16_to_cpu(readw(udc->regs + DC_DATAPORT));
218 
219 	req->req.actual += len;
220 
221 	/*
222 	 * TODO: The short_not_ok flag isn't supported yet, but isn't used by
223 	 * any gadget driver either.
224 	 */
225 
226 	dev_dbg(udc->isp->dev,
227 		"%s: req %p actual/length %u/%u maxpacket %u packet size %u\n",
228 		__func__, req, req->req.actual, req->req.length, ep->maxpacket,
229 		len);
230 
231 	ep->rx_pending = false;
232 
233 	/*
234 	 * Complete the request if all data has been received or if a short
235 	 * packet has been received.
236 	 */
237 	if (req->req.actual == req->req.length || len < ep->maxpacket) {
238 		list_del(&req->queue);
239 		return true;
240 	}
241 
242 	return false;
243 }
244 
245 static void isp1760_udc_transmit(struct isp1760_ep *ep,
246 				 struct isp1760_request *req)
247 {
248 	struct isp1760_udc *udc = ep->udc;
249 	u32 *buf = req->req.buf + req->req.actual;
250 	int i;
251 
252 	req->packet_size = min(req->req.length - req->req.actual,
253 			       ep->maxpacket);
254 
255 	dev_dbg(udc->isp->dev, "%s: transferring %u bytes (%u/%u done)\n",
256 		__func__, req->packet_size, req->req.actual,
257 		req->req.length);
258 
259 	__isp1760_udc_select_ep(ep, USB_DIR_IN);
260 
261 	if (req->packet_size)
262 		isp1760_udc_write(udc, DC_BUFLEN, req->packet_size);
263 
264 	/*
265 	 * Make sure not to write more than one extra byte, otherwise extra data
266 	 * will stay in the FIFO and will be transmitted during the next control
267 	 * request. The endpoint control CLBUF bit is supposed to allow flushing
268 	 * the FIFO for this kind of conditions, but doesn't seem to work.
269 	 */
270 	for (i = req->packet_size; i > 2; i -= 4, ++buf)
271 		isp1760_udc_write(udc, DC_DATAPORT, cpu_to_le32(*buf));
272 	if (i > 0)
273 		writew(cpu_to_le16(*(u16 *)buf), udc->regs + DC_DATAPORT);
274 
275 	if (ep->addr == 0)
276 		isp1760_udc_write(udc, DC_CTRLFUNC, DC_DSEN);
277 	if (!req->packet_size)
278 		isp1760_udc_write(udc, DC_CTRLFUNC, DC_VENDP);
279 }
280 
281 static void isp1760_ep_rx_ready(struct isp1760_ep *ep)
282 {
283 	struct isp1760_udc *udc = ep->udc;
284 	struct isp1760_request *req;
285 	bool complete;
286 
287 	spin_lock(&udc->lock);
288 
289 	if (ep->addr == 0 && udc->ep0_state != ISP1760_CTRL_DATA_OUT) {
290 		spin_unlock(&udc->lock);
291 		dev_dbg(udc->isp->dev, "%s: invalid ep0 state %u\n", __func__,
292 			udc->ep0_state);
293 		return;
294 	}
295 
296 	if (ep->addr != 0 && !ep->desc) {
297 		spin_unlock(&udc->lock);
298 		dev_dbg(udc->isp->dev, "%s: ep%02x is disabled\n", __func__,
299 			ep->addr);
300 		return;
301 	}
302 
303 	if (list_empty(&ep->queue)) {
304 		ep->rx_pending = true;
305 		spin_unlock(&udc->lock);
306 		dev_dbg(udc->isp->dev, "%s: ep%02x (%p) has no request queued\n",
307 			__func__, ep->addr, ep);
308 		return;
309 	}
310 
311 	req = list_first_entry(&ep->queue, struct isp1760_request,
312 			       queue);
313 	complete = isp1760_udc_receive(ep, req);
314 
315 	spin_unlock(&udc->lock);
316 
317 	if (complete)
318 		isp1760_udc_request_complete(ep, req, 0);
319 }
320 
321 static void isp1760_ep_tx_complete(struct isp1760_ep *ep)
322 {
323 	struct isp1760_udc *udc = ep->udc;
324 	struct isp1760_request *complete = NULL;
325 	struct isp1760_request *req;
326 	bool need_zlp;
327 
328 	spin_lock(&udc->lock);
329 
330 	if (ep->addr == 0 && udc->ep0_state != ISP1760_CTRL_DATA_IN) {
331 		spin_unlock(&udc->lock);
332 		dev_dbg(udc->isp->dev, "TX IRQ: invalid endpoint state %u\n",
333 			udc->ep0_state);
334 		return;
335 	}
336 
337 	if (list_empty(&ep->queue)) {
338 		/*
339 		 * This can happen for the control endpoint when the reply to
340 		 * the GET_STATUS IN control request is sent directly by the
341 		 * setup IRQ handler. Just proceed to the status stage.
342 		 */
343 		if (ep->addr == 0) {
344 			isp1760_udc_ctrl_send_status(ep, USB_DIR_IN);
345 			spin_unlock(&udc->lock);
346 			return;
347 		}
348 
349 		spin_unlock(&udc->lock);
350 		dev_dbg(udc->isp->dev, "%s: ep%02x has no request queued\n",
351 			__func__, ep->addr);
352 		return;
353 	}
354 
355 	req = list_first_entry(&ep->queue, struct isp1760_request,
356 			       queue);
357 	req->req.actual += req->packet_size;
358 
359 	need_zlp = req->req.actual == req->req.length &&
360 		   !(req->req.length % ep->maxpacket) &&
361 		   req->packet_size && req->req.zero;
362 
363 	dev_dbg(udc->isp->dev,
364 		"TX IRQ: req %p actual/length %u/%u maxpacket %u packet size %u zero %u need zlp %u\n",
365 		 req, req->req.actual, req->req.length, ep->maxpacket,
366 		 req->packet_size, req->req.zero, need_zlp);
367 
368 	/*
369 	 * Complete the request if all data has been sent and we don't need to
370 	 * transmit a zero length packet.
371 	 */
372 	if (req->req.actual == req->req.length && !need_zlp) {
373 		complete = req;
374 		list_del(&req->queue);
375 
376 		if (ep->addr == 0)
377 			isp1760_udc_ctrl_send_status(ep, USB_DIR_IN);
378 
379 		if (!list_empty(&ep->queue))
380 			req = list_first_entry(&ep->queue,
381 					       struct isp1760_request, queue);
382 		else
383 			req = NULL;
384 	}
385 
386 	/*
387 	 * Transmit the next packet or start the next request, if any.
388 	 *
389 	 * TODO: If the endpoint is stalled the next request shouldn't be
390 	 * started, but what about the next packet ?
391 	 */
392 	if (req)
393 		isp1760_udc_transmit(ep, req);
394 
395 	spin_unlock(&udc->lock);
396 
397 	if (complete)
398 		isp1760_udc_request_complete(ep, complete, 0);
399 }
400 
401 static int __isp1760_udc_set_halt(struct isp1760_ep *ep, bool halt)
402 {
403 	struct isp1760_udc *udc = ep->udc;
404 
405 	dev_dbg(udc->isp->dev, "%s: %s halt on ep%02x\n", __func__,
406 		halt ? "set" : "clear", ep->addr);
407 
408 	if (ep->desc && usb_endpoint_xfer_isoc(ep->desc)) {
409 		dev_dbg(udc->isp->dev, "%s: ep%02x is isochronous\n", __func__,
410 			ep->addr);
411 		return -EINVAL;
412 	}
413 
414 	isp1760_udc_select_ep(ep);
415 	isp1760_udc_write(udc, DC_CTRLFUNC, halt ? DC_STALL : 0);
416 
417 	if (ep->addr == 0) {
418 		/* When halting the control endpoint, stall both IN and OUT. */
419 		__isp1760_udc_select_ep(ep, USB_DIR_IN);
420 		isp1760_udc_write(udc, DC_CTRLFUNC, halt ? DC_STALL : 0);
421 	} else if (!halt) {
422 		/* Reset the data PID by cycling the endpoint enable bit. */
423 		u16 eptype = isp1760_udc_read(udc, DC_EPTYPE);
424 
425 		isp1760_udc_write(udc, DC_EPTYPE, eptype & ~DC_EPENABLE);
426 		isp1760_udc_write(udc, DC_EPTYPE, eptype);
427 
428 		/*
429 		 * Disabling the endpoint emptied the transmit FIFO, fill it
430 		 * again if a request is pending.
431 		 *
432 		 * TODO: Does the gadget framework require synchronizatino with
433 		 * the TX IRQ handler ?
434 		 */
435 		if ((ep->addr & USB_DIR_IN) && !list_empty(&ep->queue)) {
436 			struct isp1760_request *req;
437 
438 			req = list_first_entry(&ep->queue,
439 					       struct isp1760_request, queue);
440 			isp1760_udc_transmit(ep, req);
441 		}
442 	}
443 
444 	ep->halted = halt;
445 
446 	return 0;
447 }
448 
449 /* -----------------------------------------------------------------------------
450  * Control Endpoint
451  */
452 
453 static int isp1760_udc_get_status(struct isp1760_udc *udc,
454 				  const struct usb_ctrlrequest *req)
455 {
456 	struct isp1760_ep *ep;
457 	u16 status;
458 
459 	if (req->wLength != cpu_to_le16(2) || req->wValue != cpu_to_le16(0))
460 		return -EINVAL;
461 
462 	switch (req->bRequestType) {
463 	case USB_DIR_IN | USB_RECIP_DEVICE:
464 		status = udc->devstatus;
465 		break;
466 
467 	case USB_DIR_IN | USB_RECIP_INTERFACE:
468 		status = 0;
469 		break;
470 
471 	case USB_DIR_IN | USB_RECIP_ENDPOINT:
472 		ep = isp1760_udc_find_ep(udc, le16_to_cpu(req->wIndex));
473 		if (!ep)
474 			return -EINVAL;
475 
476 		status = 0;
477 		if (ep->halted)
478 			status |= 1 << USB_ENDPOINT_HALT;
479 		break;
480 
481 	default:
482 		return -EINVAL;
483 	}
484 
485 	isp1760_udc_write(udc, DC_EPINDEX, DC_ENDPIDX(0) | DC_EPDIR);
486 	isp1760_udc_write(udc, DC_BUFLEN, 2);
487 
488 	writew(cpu_to_le16(status), udc->regs + DC_DATAPORT);
489 
490 	isp1760_udc_write(udc, DC_CTRLFUNC, DC_DSEN);
491 
492 	dev_dbg(udc->isp->dev, "%s: status 0x%04x\n", __func__, status);
493 
494 	return 0;
495 }
496 
497 static int isp1760_udc_set_address(struct isp1760_udc *udc, u16 addr)
498 {
499 	if (addr > 127) {
500 		dev_dbg(udc->isp->dev, "invalid device address %u\n", addr);
501 		return -EINVAL;
502 	}
503 
504 	if (udc->gadget.state != USB_STATE_DEFAULT &&
505 	    udc->gadget.state != USB_STATE_ADDRESS) {
506 		dev_dbg(udc->isp->dev, "can't set address in state %u\n",
507 			udc->gadget.state);
508 		return -EINVAL;
509 	}
510 
511 	usb_gadget_set_state(&udc->gadget, addr ? USB_STATE_ADDRESS :
512 			     USB_STATE_DEFAULT);
513 
514 	isp1760_udc_write(udc, DC_ADDRESS, DC_DEVEN | addr);
515 
516 	spin_lock(&udc->lock);
517 	isp1760_udc_ctrl_send_status(&udc->ep[0], USB_DIR_OUT);
518 	spin_unlock(&udc->lock);
519 
520 	return 0;
521 }
522 
523 static bool isp1760_ep0_setup_standard(struct isp1760_udc *udc,
524 				       struct usb_ctrlrequest *req)
525 {
526 	bool stall;
527 
528 	switch (req->bRequest) {
529 	case USB_REQ_GET_STATUS:
530 		return isp1760_udc_get_status(udc, req);
531 
532 	case USB_REQ_CLEAR_FEATURE:
533 		switch (req->bRequestType) {
534 		case USB_DIR_OUT | USB_RECIP_DEVICE: {
535 			/* TODO: Handle remote wakeup feature. */
536 			return true;
537 		}
538 
539 		case USB_DIR_OUT | USB_RECIP_ENDPOINT: {
540 			u16 index = le16_to_cpu(req->wIndex);
541 			struct isp1760_ep *ep;
542 
543 			if (req->wLength != cpu_to_le16(0) ||
544 			    req->wValue != cpu_to_le16(USB_ENDPOINT_HALT))
545 				return true;
546 
547 			ep = isp1760_udc_find_ep(udc, index);
548 			if (!ep)
549 				return true;
550 
551 			spin_lock(&udc->lock);
552 
553 			/*
554 			 * If the endpoint is wedged only the gadget can clear
555 			 * the halt feature. Pretend success in that case, but
556 			 * keep the endpoint halted.
557 			 */
558 			if (!ep->wedged)
559 				stall = __isp1760_udc_set_halt(ep, false);
560 			else
561 				stall = false;
562 
563 			if (!stall)
564 				isp1760_udc_ctrl_send_status(&udc->ep[0],
565 							     USB_DIR_OUT);
566 
567 			spin_unlock(&udc->lock);
568 			return stall;
569 		}
570 
571 		default:
572 			return true;
573 		}
574 		break;
575 
576 	case USB_REQ_SET_FEATURE:
577 		switch (req->bRequestType) {
578 		case USB_DIR_OUT | USB_RECIP_DEVICE: {
579 			/* TODO: Handle remote wakeup and test mode features */
580 			return true;
581 		}
582 
583 		case USB_DIR_OUT | USB_RECIP_ENDPOINT: {
584 			u16 index = le16_to_cpu(req->wIndex);
585 			struct isp1760_ep *ep;
586 
587 			if (req->wLength != cpu_to_le16(0) ||
588 			    req->wValue != cpu_to_le16(USB_ENDPOINT_HALT))
589 				return true;
590 
591 			ep = isp1760_udc_find_ep(udc, index);
592 			if (!ep)
593 				return true;
594 
595 			spin_lock(&udc->lock);
596 
597 			stall = __isp1760_udc_set_halt(ep, true);
598 			if (!stall)
599 				isp1760_udc_ctrl_send_status(&udc->ep[0],
600 							     USB_DIR_OUT);
601 
602 			spin_unlock(&udc->lock);
603 			return stall;
604 		}
605 
606 		default:
607 			return true;
608 		}
609 		break;
610 
611 	case USB_REQ_SET_ADDRESS:
612 		if (req->bRequestType != (USB_DIR_OUT | USB_RECIP_DEVICE))
613 			return true;
614 
615 		return isp1760_udc_set_address(udc, le16_to_cpu(req->wValue));
616 
617 	case USB_REQ_SET_CONFIGURATION:
618 		if (req->bRequestType != (USB_DIR_OUT | USB_RECIP_DEVICE))
619 			return true;
620 
621 		if (udc->gadget.state != USB_STATE_ADDRESS &&
622 		    udc->gadget.state != USB_STATE_CONFIGURED)
623 			return true;
624 
625 		stall = udc->driver->setup(&udc->gadget, req) < 0;
626 		if (stall)
627 			return true;
628 
629 		usb_gadget_set_state(&udc->gadget, req->wValue ?
630 				     USB_STATE_CONFIGURED : USB_STATE_ADDRESS);
631 
632 		/*
633 		 * SET_CONFIGURATION (and SET_INTERFACE) must reset the halt
634 		 * feature on all endpoints. There is however no need to do so
635 		 * explicitly here as the gadget driver will disable and
636 		 * reenable endpoints, clearing the halt feature.
637 		 */
638 		return false;
639 
640 	default:
641 		return udc->driver->setup(&udc->gadget, req) < 0;
642 	}
643 }
644 
645 static void isp1760_ep0_setup(struct isp1760_udc *udc)
646 {
647 	union {
648 		struct usb_ctrlrequest r;
649 		u32 data[2];
650 	} req;
651 	unsigned int count;
652 	bool stall = false;
653 
654 	spin_lock(&udc->lock);
655 
656 	isp1760_udc_write(udc, DC_EPINDEX, DC_EP0SETUP);
657 
658 	count = isp1760_udc_read(udc, DC_BUFLEN) & DC_DATACOUNT_MASK;
659 	if (count != sizeof(req)) {
660 		spin_unlock(&udc->lock);
661 
662 		dev_err(udc->isp->dev, "invalid length %u for setup packet\n",
663 			count);
664 
665 		isp1760_udc_ctrl_send_stall(&udc->ep[0]);
666 		return;
667 	}
668 
669 	req.data[0] = isp1760_udc_read(udc, DC_DATAPORT);
670 	req.data[1] = isp1760_udc_read(udc, DC_DATAPORT);
671 
672 	if (udc->ep0_state != ISP1760_CTRL_SETUP) {
673 		spin_unlock(&udc->lock);
674 		dev_dbg(udc->isp->dev, "unexpected SETUP packet\n");
675 		return;
676 	}
677 
678 	/* Move to the data stage. */
679 	if (!req.r.wLength)
680 		udc->ep0_state = ISP1760_CTRL_STATUS;
681 	else if (req.r.bRequestType & USB_DIR_IN)
682 		udc->ep0_state = ISP1760_CTRL_DATA_IN;
683 	else
684 		udc->ep0_state = ISP1760_CTRL_DATA_OUT;
685 
686 	udc->ep0_dir = req.r.bRequestType & USB_DIR_IN;
687 	udc->ep0_length = le16_to_cpu(req.r.wLength);
688 
689 	spin_unlock(&udc->lock);
690 
691 	dev_dbg(udc->isp->dev,
692 		"%s: bRequestType 0x%02x bRequest 0x%02x wValue 0x%04x wIndex 0x%04x wLength 0x%04x\n",
693 		__func__, req.r.bRequestType, req.r.bRequest,
694 		le16_to_cpu(req.r.wValue), le16_to_cpu(req.r.wIndex),
695 		le16_to_cpu(req.r.wLength));
696 
697 	if ((req.r.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD)
698 		stall = isp1760_ep0_setup_standard(udc, &req.r);
699 	else
700 		stall = udc->driver->setup(&udc->gadget, &req.r) < 0;
701 
702 	if (stall)
703 		isp1760_udc_ctrl_send_stall(&udc->ep[0]);
704 }
705 
706 /* -----------------------------------------------------------------------------
707  * Gadget Endpoint Operations
708  */
709 
710 static int isp1760_ep_enable(struct usb_ep *ep,
711 			     const struct usb_endpoint_descriptor *desc)
712 {
713 	struct isp1760_ep *uep = ep_to_udc_ep(ep);
714 	struct isp1760_udc *udc = uep->udc;
715 	unsigned long flags;
716 	unsigned int type;
717 
718 	dev_dbg(uep->udc->isp->dev, "%s\n", __func__);
719 
720 	/*
721 	 * Validate the descriptor. The control endpoint can't be enabled
722 	 * manually.
723 	 */
724 	if (desc->bDescriptorType != USB_DT_ENDPOINT ||
725 	    desc->bEndpointAddress == 0 ||
726 	    desc->bEndpointAddress != uep->addr ||
727 	    le16_to_cpu(desc->wMaxPacketSize) > ep->maxpacket) {
728 		dev_dbg(udc->isp->dev,
729 			"%s: invalid descriptor type %u addr %02x ep addr %02x max packet size %u/%u\n",
730 			__func__, desc->bDescriptorType,
731 			desc->bEndpointAddress, uep->addr,
732 			le16_to_cpu(desc->wMaxPacketSize), ep->maxpacket);
733 		return -EINVAL;
734 	}
735 
736 	switch (usb_endpoint_type(desc)) {
737 	case USB_ENDPOINT_XFER_ISOC:
738 		type = DC_ENDPTYP_ISOC;
739 		break;
740 	case USB_ENDPOINT_XFER_BULK:
741 		type = DC_ENDPTYP_BULK;
742 		break;
743 	case USB_ENDPOINT_XFER_INT:
744 		type = DC_ENDPTYP_INTERRUPT;
745 		break;
746 	case USB_ENDPOINT_XFER_CONTROL:
747 	default:
748 		dev_dbg(udc->isp->dev, "%s: control endpoints unsupported\n",
749 			__func__);
750 		return -EINVAL;
751 	}
752 
753 	spin_lock_irqsave(&udc->lock, flags);
754 
755 	uep->desc = desc;
756 	uep->maxpacket = le16_to_cpu(desc->wMaxPacketSize);
757 	uep->rx_pending = false;
758 	uep->halted = false;
759 	uep->wedged = false;
760 
761 	isp1760_udc_select_ep(uep);
762 	isp1760_udc_write(udc, DC_EPMAXPKTSZ, uep->maxpacket);
763 	isp1760_udc_write(udc, DC_BUFLEN, uep->maxpacket);
764 	isp1760_udc_write(udc, DC_EPTYPE, DC_EPENABLE | type);
765 
766 	spin_unlock_irqrestore(&udc->lock, flags);
767 
768 	return 0;
769 }
770 
771 static int isp1760_ep_disable(struct usb_ep *ep)
772 {
773 	struct isp1760_ep *uep = ep_to_udc_ep(ep);
774 	struct isp1760_udc *udc = uep->udc;
775 	struct isp1760_request *req, *nreq;
776 	LIST_HEAD(req_list);
777 	unsigned long flags;
778 
779 	dev_dbg(udc->isp->dev, "%s\n", __func__);
780 
781 	spin_lock_irqsave(&udc->lock, flags);
782 
783 	if (!uep->desc) {
784 		dev_dbg(udc->isp->dev, "%s: endpoint not enabled\n", __func__);
785 		spin_unlock_irqrestore(&udc->lock, flags);
786 		return -EINVAL;
787 	}
788 
789 	uep->desc = NULL;
790 	uep->maxpacket = 0;
791 
792 	isp1760_udc_select_ep(uep);
793 	isp1760_udc_write(udc, DC_EPTYPE, 0);
794 
795 	/* TODO Synchronize with the IRQ handler */
796 
797 	list_splice_init(&uep->queue, &req_list);
798 
799 	spin_unlock_irqrestore(&udc->lock, flags);
800 
801 	list_for_each_entry_safe(req, nreq, &req_list, queue) {
802 		list_del(&req->queue);
803 		isp1760_udc_request_complete(uep, req, -ESHUTDOWN);
804 	}
805 
806 	return 0;
807 }
808 
809 static struct usb_request *isp1760_ep_alloc_request(struct usb_ep *ep,
810 						    gfp_t gfp_flags)
811 {
812 	struct isp1760_request *req;
813 
814 	req = kzalloc(sizeof(*req), gfp_flags);
815 	if (!req)
816 		return NULL;
817 
818 	return &req->req;
819 }
820 
821 static void isp1760_ep_free_request(struct usb_ep *ep, struct usb_request *_req)
822 {
823 	struct isp1760_request *req = req_to_udc_req(_req);
824 
825 	kfree(req);
826 }
827 
828 static int isp1760_ep_queue(struct usb_ep *ep, struct usb_request *_req,
829 			    gfp_t gfp_flags)
830 {
831 	struct isp1760_request *req = req_to_udc_req(_req);
832 	struct isp1760_ep *uep = ep_to_udc_ep(ep);
833 	struct isp1760_udc *udc = uep->udc;
834 	bool complete = false;
835 	unsigned long flags;
836 	int ret = 0;
837 
838 	_req->status = -EINPROGRESS;
839 	_req->actual = 0;
840 
841 	spin_lock_irqsave(&udc->lock, flags);
842 
843 	dev_dbg(udc->isp->dev,
844 		"%s: req %p (%u bytes%s) ep %p(0x%02x)\n", __func__, _req,
845 		_req->length, _req->zero ? " (zlp)" : "", uep, uep->addr);
846 
847 	req->ep = uep;
848 
849 	if (uep->addr == 0) {
850 		if (_req->length != udc->ep0_length &&
851 		    udc->ep0_state != ISP1760_CTRL_DATA_IN) {
852 			dev_dbg(udc->isp->dev,
853 				"%s: invalid length %u for req %p\n",
854 				__func__, _req->length, req);
855 			ret = -EINVAL;
856 			goto done;
857 		}
858 
859 		switch (udc->ep0_state) {
860 		case ISP1760_CTRL_DATA_IN:
861 			dev_dbg(udc->isp->dev, "%s: transmitting req %p\n",
862 				__func__, req);
863 
864 			list_add_tail(&req->queue, &uep->queue);
865 			isp1760_udc_transmit(uep, req);
866 			break;
867 
868 		case ISP1760_CTRL_DATA_OUT:
869 			list_add_tail(&req->queue, &uep->queue);
870 			__isp1760_udc_select_ep(uep, USB_DIR_OUT);
871 			isp1760_udc_write(udc, DC_CTRLFUNC, DC_DSEN);
872 			break;
873 
874 		case ISP1760_CTRL_STATUS:
875 			complete = true;
876 			break;
877 
878 		default:
879 			dev_dbg(udc->isp->dev, "%s: invalid ep0 state\n",
880 				__func__);
881 			ret = -EINVAL;
882 			break;
883 		}
884 	} else if (uep->desc) {
885 		bool empty = list_empty(&uep->queue);
886 
887 		list_add_tail(&req->queue, &uep->queue);
888 		if ((uep->addr & USB_DIR_IN) && !uep->halted && empty)
889 			isp1760_udc_transmit(uep, req);
890 		else if (!(uep->addr & USB_DIR_IN) && uep->rx_pending)
891 			complete = isp1760_udc_receive(uep, req);
892 	} else {
893 		dev_dbg(udc->isp->dev,
894 			"%s: can't queue request to disabled ep%02x\n",
895 			__func__, uep->addr);
896 		ret = -ESHUTDOWN;
897 	}
898 
899 done:
900 	if (ret < 0)
901 		req->ep = NULL;
902 
903 	spin_unlock_irqrestore(&udc->lock, flags);
904 
905 	if (complete)
906 		isp1760_udc_request_complete(uep, req, 0);
907 
908 	return ret;
909 }
910 
911 static int isp1760_ep_dequeue(struct usb_ep *ep, struct usb_request *_req)
912 {
913 	struct isp1760_request *req = req_to_udc_req(_req);
914 	struct isp1760_ep *uep = ep_to_udc_ep(ep);
915 	struct isp1760_udc *udc = uep->udc;
916 	unsigned long flags;
917 
918 	dev_dbg(uep->udc->isp->dev, "%s(ep%02x)\n", __func__, uep->addr);
919 
920 	spin_lock_irqsave(&udc->lock, flags);
921 
922 	if (req->ep != uep)
923 		req = NULL;
924 	else
925 		list_del(&req->queue);
926 
927 	spin_unlock_irqrestore(&udc->lock, flags);
928 
929 	if (!req)
930 		return -EINVAL;
931 
932 	isp1760_udc_request_complete(uep, req, -ECONNRESET);
933 	return 0;
934 }
935 
936 static int __isp1760_ep_set_halt(struct isp1760_ep *uep, bool stall, bool wedge)
937 {
938 	struct isp1760_udc *udc = uep->udc;
939 	int ret;
940 
941 	if (!uep->addr) {
942 		/*
943 		 * Halting the control endpoint is only valid as a delayed error
944 		 * response to a SETUP packet. Make sure EP0 is in the right
945 		 * stage and that the gadget isn't trying to clear the halt
946 		 * condition.
947 		 */
948 		if (WARN_ON(udc->ep0_state == ISP1760_CTRL_SETUP || !stall ||
949 			     wedge)) {
950 			return -EINVAL;
951 		}
952 	}
953 
954 	if (uep->addr && !uep->desc) {
955 		dev_dbg(udc->isp->dev, "%s: ep%02x is disabled\n", __func__,
956 			uep->addr);
957 		return -EINVAL;
958 	}
959 
960 	if (uep->addr & USB_DIR_IN) {
961 		/* Refuse to halt IN endpoints with active transfers. */
962 		if (!list_empty(&uep->queue)) {
963 			dev_dbg(udc->isp->dev,
964 				"%s: ep%02x has request pending\n", __func__,
965 				uep->addr);
966 			return -EAGAIN;
967 		}
968 	}
969 
970 	ret = __isp1760_udc_set_halt(uep, stall);
971 	if (ret < 0)
972 		return ret;
973 
974 	if (!uep->addr) {
975 		/*
976 		 * Stalling EP0 completes the control transaction, move back to
977 		 * the SETUP state.
978 		 */
979 		udc->ep0_state = ISP1760_CTRL_SETUP;
980 		return 0;
981 	}
982 
983 	if (wedge)
984 		uep->wedged = true;
985 	else if (!stall)
986 		uep->wedged = false;
987 
988 	return 0;
989 }
990 
991 static int isp1760_ep_set_halt(struct usb_ep *ep, int value)
992 {
993 	struct isp1760_ep *uep = ep_to_udc_ep(ep);
994 	unsigned long flags;
995 	int ret;
996 
997 	dev_dbg(uep->udc->isp->dev, "%s: %s halt on ep%02x\n", __func__,
998 		value ? "set" : "clear", uep->addr);
999 
1000 	spin_lock_irqsave(&uep->udc->lock, flags);
1001 	ret = __isp1760_ep_set_halt(uep, value, false);
1002 	spin_unlock_irqrestore(&uep->udc->lock, flags);
1003 
1004 	return ret;
1005 }
1006 
1007 static int isp1760_ep_set_wedge(struct usb_ep *ep)
1008 {
1009 	struct isp1760_ep *uep = ep_to_udc_ep(ep);
1010 	unsigned long flags;
1011 	int ret;
1012 
1013 	dev_dbg(uep->udc->isp->dev, "%s: set wedge on ep%02x)\n", __func__,
1014 		uep->addr);
1015 
1016 	spin_lock_irqsave(&uep->udc->lock, flags);
1017 	ret = __isp1760_ep_set_halt(uep, true, true);
1018 	spin_unlock_irqrestore(&uep->udc->lock, flags);
1019 
1020 	return ret;
1021 }
1022 
1023 static void isp1760_ep_fifo_flush(struct usb_ep *ep)
1024 {
1025 	struct isp1760_ep *uep = ep_to_udc_ep(ep);
1026 	struct isp1760_udc *udc = uep->udc;
1027 	unsigned long flags;
1028 
1029 	spin_lock_irqsave(&udc->lock, flags);
1030 
1031 	isp1760_udc_select_ep(uep);
1032 
1033 	/*
1034 	 * Set the CLBUF bit twice to flush both buffers in case double
1035 	 * buffering is enabled.
1036 	 */
1037 	isp1760_udc_write(udc, DC_CTRLFUNC, DC_CLBUF);
1038 	isp1760_udc_write(udc, DC_CTRLFUNC, DC_CLBUF);
1039 
1040 	spin_unlock_irqrestore(&udc->lock, flags);
1041 }
1042 
1043 static const struct usb_ep_ops isp1760_ep_ops = {
1044 	.enable = isp1760_ep_enable,
1045 	.disable = isp1760_ep_disable,
1046 	.alloc_request = isp1760_ep_alloc_request,
1047 	.free_request = isp1760_ep_free_request,
1048 	.queue = isp1760_ep_queue,
1049 	.dequeue = isp1760_ep_dequeue,
1050 	.set_halt = isp1760_ep_set_halt,
1051 	.set_wedge = isp1760_ep_set_wedge,
1052 	.fifo_flush = isp1760_ep_fifo_flush,
1053 };
1054 
1055 /* -----------------------------------------------------------------------------
1056  * Device States
1057  */
1058 
1059 /* Called with the UDC spinlock held. */
1060 static void isp1760_udc_connect(struct isp1760_udc *udc)
1061 {
1062 	usb_gadget_set_state(&udc->gadget, USB_STATE_POWERED);
1063 	mod_timer(&udc->vbus_timer, jiffies + ISP1760_VBUS_POLL_INTERVAL);
1064 }
1065 
1066 /* Called with the UDC spinlock held. */
1067 static void isp1760_udc_disconnect(struct isp1760_udc *udc)
1068 {
1069 	if (udc->gadget.state < USB_STATE_POWERED)
1070 		return;
1071 
1072 	dev_dbg(udc->isp->dev, "Device disconnected in state %u\n",
1073 		 udc->gadget.state);
1074 
1075 	udc->gadget.speed = USB_SPEED_UNKNOWN;
1076 	usb_gadget_set_state(&udc->gadget, USB_STATE_ATTACHED);
1077 
1078 	if (udc->driver->disconnect)
1079 		udc->driver->disconnect(&udc->gadget);
1080 
1081 	del_timer(&udc->vbus_timer);
1082 
1083 	/* TODO Reset all endpoints ? */
1084 }
1085 
1086 static void isp1760_udc_init_hw(struct isp1760_udc *udc)
1087 {
1088 	/*
1089 	 * The device controller currently shares its interrupt with the host
1090 	 * controller, the DC_IRQ polarity and signaling mode are ignored. Set
1091 	 * the to active-low level-triggered.
1092 	 *
1093 	 * Configure the control, in and out pipes to generate interrupts on
1094 	 * ACK tokens only (and NYET for the out pipe). The default
1095 	 * configuration also generates an interrupt on the first NACK token.
1096 	 */
1097 	isp1760_udc_write(udc, DC_INTCONF, DC_CDBGMOD_ACK | DC_DDBGMODIN_ACK |
1098 			  DC_DDBGMODOUT_ACK_NYET);
1099 
1100 	isp1760_udc_write(udc, DC_INTENABLE, DC_IEPRXTX(7) | DC_IEPRXTX(6) |
1101 			  DC_IEPRXTX(5) | DC_IEPRXTX(4) | DC_IEPRXTX(3) |
1102 			  DC_IEPRXTX(2) | DC_IEPRXTX(1) | DC_IEPRXTX(0) |
1103 			  DC_IEP0SETUP | DC_IEVBUS | DC_IERESM | DC_IESUSP |
1104 			  DC_IEHS_STA | DC_IEBRST);
1105 
1106 	if (udc->connected)
1107 		isp1760_set_pullup(udc->isp, true);
1108 
1109 	isp1760_udc_write(udc, DC_ADDRESS, DC_DEVEN);
1110 }
1111 
1112 static void isp1760_udc_reset(struct isp1760_udc *udc)
1113 {
1114 	unsigned long flags;
1115 
1116 	spin_lock_irqsave(&udc->lock, flags);
1117 
1118 	/*
1119 	 * The bus reset has reset most registers to their default value,
1120 	 * reinitialize the UDC hardware.
1121 	 */
1122 	isp1760_udc_init_hw(udc);
1123 
1124 	udc->ep0_state = ISP1760_CTRL_SETUP;
1125 	udc->gadget.speed = USB_SPEED_FULL;
1126 
1127 	usb_gadget_udc_reset(&udc->gadget, udc->driver);
1128 
1129 	spin_unlock_irqrestore(&udc->lock, flags);
1130 }
1131 
1132 static void isp1760_udc_suspend(struct isp1760_udc *udc)
1133 {
1134 	if (udc->gadget.state < USB_STATE_DEFAULT)
1135 		return;
1136 
1137 	if (udc->driver->suspend)
1138 		udc->driver->suspend(&udc->gadget);
1139 }
1140 
1141 static void isp1760_udc_resume(struct isp1760_udc *udc)
1142 {
1143 	if (udc->gadget.state < USB_STATE_DEFAULT)
1144 		return;
1145 
1146 	if (udc->driver->resume)
1147 		udc->driver->resume(&udc->gadget);
1148 }
1149 
1150 /* -----------------------------------------------------------------------------
1151  * Gadget Operations
1152  */
1153 
1154 static int isp1760_udc_get_frame(struct usb_gadget *gadget)
1155 {
1156 	struct isp1760_udc *udc = gadget_to_udc(gadget);
1157 
1158 	return isp1760_udc_read(udc, DC_FRAMENUM) & ((1 << 11) - 1);
1159 }
1160 
1161 static int isp1760_udc_wakeup(struct usb_gadget *gadget)
1162 {
1163 	struct isp1760_udc *udc = gadget_to_udc(gadget);
1164 
1165 	dev_dbg(udc->isp->dev, "%s\n", __func__);
1166 	return -ENOTSUPP;
1167 }
1168 
1169 static int isp1760_udc_set_selfpowered(struct usb_gadget *gadget,
1170 				       int is_selfpowered)
1171 {
1172 	struct isp1760_udc *udc = gadget_to_udc(gadget);
1173 
1174 	if (is_selfpowered)
1175 		udc->devstatus |= 1 << USB_DEVICE_SELF_POWERED;
1176 	else
1177 		udc->devstatus &= ~(1 << USB_DEVICE_SELF_POWERED);
1178 
1179 	return 0;
1180 }
1181 
1182 static int isp1760_udc_pullup(struct usb_gadget *gadget, int is_on)
1183 {
1184 	struct isp1760_udc *udc = gadget_to_udc(gadget);
1185 
1186 	isp1760_set_pullup(udc->isp, is_on);
1187 	udc->connected = is_on;
1188 
1189 	return 0;
1190 }
1191 
1192 static int isp1760_udc_start(struct usb_gadget *gadget,
1193 			     struct usb_gadget_driver *driver)
1194 {
1195 	struct isp1760_udc *udc = gadget_to_udc(gadget);
1196 	unsigned long flags;
1197 
1198 	/* The hardware doesn't support low speed. */
1199 	if (driver->max_speed < USB_SPEED_FULL) {
1200 		dev_err(udc->isp->dev, "Invalid gadget driver\n");
1201 		return -EINVAL;
1202 	}
1203 
1204 	spin_lock_irqsave(&udc->lock, flags);
1205 
1206 	if (udc->driver) {
1207 		dev_err(udc->isp->dev, "UDC already has a gadget driver\n");
1208 		spin_unlock_irqrestore(&udc->lock, flags);
1209 		return -EBUSY;
1210 	}
1211 
1212 	udc->driver = driver;
1213 
1214 	spin_unlock_irqrestore(&udc->lock, flags);
1215 
1216 	dev_dbg(udc->isp->dev, "starting UDC with driver %s\n",
1217 		driver->function);
1218 
1219 	udc->devstatus = 0;
1220 	udc->connected = true;
1221 
1222 	usb_gadget_set_state(&udc->gadget, USB_STATE_ATTACHED);
1223 
1224 	/* DMA isn't supported yet, don't enable the DMA clock. */
1225 	isp1760_udc_write(udc, DC_MODE, DC_GLINTENA);
1226 
1227 	isp1760_udc_init_hw(udc);
1228 
1229 	dev_dbg(udc->isp->dev, "UDC started with driver %s\n",
1230 		driver->function);
1231 
1232 	return 0;
1233 }
1234 
1235 static int isp1760_udc_stop(struct usb_gadget *gadget)
1236 {
1237 	struct isp1760_udc *udc = gadget_to_udc(gadget);
1238 	unsigned long flags;
1239 
1240 	dev_dbg(udc->isp->dev, "%s\n", __func__);
1241 
1242 	del_timer_sync(&udc->vbus_timer);
1243 
1244 	isp1760_udc_write(udc, DC_MODE, 0);
1245 
1246 	spin_lock_irqsave(&udc->lock, flags);
1247 	udc->driver = NULL;
1248 	spin_unlock_irqrestore(&udc->lock, flags);
1249 
1250 	return 0;
1251 }
1252 
1253 static struct usb_gadget_ops isp1760_udc_ops = {
1254 	.get_frame = isp1760_udc_get_frame,
1255 	.wakeup = isp1760_udc_wakeup,
1256 	.set_selfpowered = isp1760_udc_set_selfpowered,
1257 	.pullup = isp1760_udc_pullup,
1258 	.udc_start = isp1760_udc_start,
1259 	.udc_stop = isp1760_udc_stop,
1260 };
1261 
1262 /* -----------------------------------------------------------------------------
1263  * Interrupt Handling
1264  */
1265 
1266 static irqreturn_t isp1760_udc_irq(int irq, void *dev)
1267 {
1268 	struct isp1760_udc *udc = dev;
1269 	unsigned int i;
1270 	u32 status;
1271 
1272 	status = isp1760_udc_read(udc, DC_INTERRUPT)
1273 	       & isp1760_udc_read(udc, DC_INTENABLE);
1274 	isp1760_udc_write(udc, DC_INTERRUPT, status);
1275 
1276 	if (status & DC_IEVBUS) {
1277 		dev_dbg(udc->isp->dev, "%s(VBUS)\n", __func__);
1278 		/* The VBUS interrupt is only triggered when VBUS appears. */
1279 		spin_lock(&udc->lock);
1280 		isp1760_udc_connect(udc);
1281 		spin_unlock(&udc->lock);
1282 	}
1283 
1284 	if (status & DC_IEBRST) {
1285 		dev_dbg(udc->isp->dev, "%s(BRST)\n", __func__);
1286 
1287 		isp1760_udc_reset(udc);
1288 	}
1289 
1290 	for (i = 0; i <= 7; ++i) {
1291 		struct isp1760_ep *ep = &udc->ep[i*2];
1292 
1293 		if (status & DC_IEPTX(i)) {
1294 			dev_dbg(udc->isp->dev, "%s(EPTX%u)\n", __func__, i);
1295 			isp1760_ep_tx_complete(ep);
1296 		}
1297 
1298 		if (status & DC_IEPRX(i)) {
1299 			dev_dbg(udc->isp->dev, "%s(EPRX%u)\n", __func__, i);
1300 			isp1760_ep_rx_ready(i ? ep - 1 : ep);
1301 		}
1302 	}
1303 
1304 	if (status & DC_IEP0SETUP) {
1305 		dev_dbg(udc->isp->dev, "%s(EP0SETUP)\n", __func__);
1306 
1307 		isp1760_ep0_setup(udc);
1308 	}
1309 
1310 	if (status & DC_IERESM) {
1311 		dev_dbg(udc->isp->dev, "%s(RESM)\n", __func__);
1312 		isp1760_udc_resume(udc);
1313 	}
1314 
1315 	if (status & DC_IESUSP) {
1316 		dev_dbg(udc->isp->dev, "%s(SUSP)\n", __func__);
1317 
1318 		spin_lock(&udc->lock);
1319 		if (!(isp1760_udc_read(udc, DC_MODE) & DC_VBUSSTAT))
1320 			isp1760_udc_disconnect(udc);
1321 		else
1322 			isp1760_udc_suspend(udc);
1323 		spin_unlock(&udc->lock);
1324 	}
1325 
1326 	if (status & DC_IEHS_STA) {
1327 		dev_dbg(udc->isp->dev, "%s(HS_STA)\n", __func__);
1328 		udc->gadget.speed = USB_SPEED_HIGH;
1329 	}
1330 
1331 	return status ? IRQ_HANDLED : IRQ_NONE;
1332 }
1333 
1334 static void isp1760_udc_vbus_poll(unsigned long data)
1335 {
1336 	struct isp1760_udc *udc = (struct isp1760_udc *)data;
1337 	unsigned long flags;
1338 
1339 	spin_lock_irqsave(&udc->lock, flags);
1340 
1341 	if (!(isp1760_udc_read(udc, DC_MODE) & DC_VBUSSTAT))
1342 		isp1760_udc_disconnect(udc);
1343 	else if (udc->gadget.state >= USB_STATE_POWERED)
1344 		mod_timer(&udc->vbus_timer,
1345 			  jiffies + ISP1760_VBUS_POLL_INTERVAL);
1346 
1347 	spin_unlock_irqrestore(&udc->lock, flags);
1348 }
1349 
1350 /* -----------------------------------------------------------------------------
1351  * Registration
1352  */
1353 
1354 static void isp1760_udc_init_eps(struct isp1760_udc *udc)
1355 {
1356 	unsigned int i;
1357 
1358 	INIT_LIST_HEAD(&udc->gadget.ep_list);
1359 
1360 	for (i = 0; i < ARRAY_SIZE(udc->ep); ++i) {
1361 		struct isp1760_ep *ep = &udc->ep[i];
1362 		unsigned int ep_num = (i + 1) / 2;
1363 		bool is_in = !(i & 1);
1364 
1365 		ep->udc = udc;
1366 
1367 		INIT_LIST_HEAD(&ep->queue);
1368 
1369 		ep->addr = (ep_num && is_in ? USB_DIR_IN : USB_DIR_OUT)
1370 			 | ep_num;
1371 		ep->desc = NULL;
1372 
1373 		sprintf(ep->name, "ep%u%s", ep_num,
1374 			ep_num ? (is_in ? "in" : "out") : "");
1375 
1376 		ep->ep.ops = &isp1760_ep_ops;
1377 		ep->ep.name = ep->name;
1378 
1379 		/*
1380 		 * Hardcode the maximum packet sizes for now, to 64 bytes for
1381 		 * the control endpoint and 512 bytes for all other endpoints.
1382 		 * This fits in the 8kB FIFO without double-buffering.
1383 		 */
1384 		if (ep_num == 0) {
1385 			usb_ep_set_maxpacket_limit(&ep->ep, 64);
1386 			ep->ep.caps.type_control = true;
1387 			ep->ep.caps.dir_in = true;
1388 			ep->ep.caps.dir_out = true;
1389 			ep->maxpacket = 64;
1390 			udc->gadget.ep0 = &ep->ep;
1391 		} else {
1392 			usb_ep_set_maxpacket_limit(&ep->ep, 512);
1393 			ep->ep.caps.type_iso = true;
1394 			ep->ep.caps.type_bulk = true;
1395 			ep->ep.caps.type_int = true;
1396 			ep->maxpacket = 0;
1397 			list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
1398 		}
1399 
1400 		if (is_in)
1401 			ep->ep.caps.dir_in = true;
1402 		else
1403 			ep->ep.caps.dir_out = true;
1404 	}
1405 }
1406 
1407 static int isp1760_udc_init(struct isp1760_udc *udc)
1408 {
1409 	u16 scratch;
1410 	u32 chipid;
1411 
1412 	/*
1413 	 * Check that the controller is present by writing to the scratch
1414 	 * register, modifying the bus pattern by reading from the chip ID
1415 	 * register, and reading the scratch register value back. The chip ID
1416 	 * and scratch register contents must match the expected values.
1417 	 */
1418 	isp1760_udc_write(udc, DC_SCRATCH, 0xbabe);
1419 	chipid = isp1760_udc_read(udc, DC_CHIPID);
1420 	scratch = isp1760_udc_read(udc, DC_SCRATCH);
1421 
1422 	if (scratch != 0xbabe) {
1423 		dev_err(udc->isp->dev,
1424 			"udc: scratch test failed (0x%04x/0x%08x)\n",
1425 			scratch, chipid);
1426 		return -ENODEV;
1427 	}
1428 
1429 	if (chipid != 0x00011582 && chipid != 0x00158210) {
1430 		dev_err(udc->isp->dev, "udc: invalid chip ID 0x%08x\n", chipid);
1431 		return -ENODEV;
1432 	}
1433 
1434 	/* Reset the device controller. */
1435 	isp1760_udc_write(udc, DC_MODE, DC_SFRESET);
1436 	usleep_range(10000, 11000);
1437 	isp1760_udc_write(udc, DC_MODE, 0);
1438 	usleep_range(10000, 11000);
1439 
1440 	return 0;
1441 }
1442 
1443 int isp1760_udc_register(struct isp1760_device *isp, int irq,
1444 			 unsigned long irqflags)
1445 {
1446 	struct isp1760_udc *udc = &isp->udc;
1447 	const char *devname;
1448 	int ret;
1449 
1450 	udc->irq = -1;
1451 	udc->isp = isp;
1452 	udc->regs = isp->regs;
1453 
1454 	spin_lock_init(&udc->lock);
1455 	setup_timer(&udc->vbus_timer, isp1760_udc_vbus_poll,
1456 		    (unsigned long)udc);
1457 
1458 	ret = isp1760_udc_init(udc);
1459 	if (ret < 0)
1460 		return ret;
1461 
1462 	devname = dev_name(isp->dev);
1463 	udc->irqname = kmalloc(strlen(devname) + 7, GFP_KERNEL);
1464 	if (!udc->irqname)
1465 		return -ENOMEM;
1466 
1467 	sprintf(udc->irqname, "%s (udc)", devname);
1468 
1469 	ret = request_irq(irq, isp1760_udc_irq, IRQF_SHARED | irqflags,
1470 			  udc->irqname, udc);
1471 	if (ret < 0)
1472 		goto error;
1473 
1474 	udc->irq = irq;
1475 
1476 	/*
1477 	 * Initialize the gadget static fields and register its device. Gadget
1478 	 * fields that vary during the life time of the gadget are initialized
1479 	 * by the UDC core.
1480 	 */
1481 	udc->gadget.ops = &isp1760_udc_ops;
1482 	udc->gadget.speed = USB_SPEED_UNKNOWN;
1483 	udc->gadget.max_speed = USB_SPEED_HIGH;
1484 	udc->gadget.name = "isp1761_udc";
1485 
1486 	isp1760_udc_init_eps(udc);
1487 
1488 	ret = usb_add_gadget_udc(isp->dev, &udc->gadget);
1489 	if (ret < 0)
1490 		goto error;
1491 
1492 	return 0;
1493 
1494 error:
1495 	if (udc->irq >= 0)
1496 		free_irq(udc->irq, udc);
1497 	kfree(udc->irqname);
1498 
1499 	return ret;
1500 }
1501 
1502 void isp1760_udc_unregister(struct isp1760_device *isp)
1503 {
1504 	struct isp1760_udc *udc = &isp->udc;
1505 
1506 	if (!udc->isp)
1507 		return;
1508 
1509 	usb_del_gadget_udc(&udc->gadget);
1510 
1511 	free_irq(udc->irq, udc);
1512 	kfree(udc->irqname);
1513 }
1514