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
29struct isp1760_request {
30	struct usb_request req;
31	struct list_head queue;
32	struct isp1760_ep *ep;
33	unsigned int packet_size;
34};
35
36static inline struct isp1760_udc *gadget_to_udc(struct usb_gadget *gadget)
37{
38	return container_of(gadget, struct isp1760_udc, gadget);
39}
40
41static inline struct isp1760_ep *ep_to_udc_ep(struct usb_ep *ep)
42{
43	return container_of(ep, struct isp1760_ep, ep);
44}
45
46static inline struct isp1760_request *req_to_udc_req(struct usb_request *req)
47{
48	return container_of(req, struct isp1760_request, req);
49}
50
51static inline u32 isp1760_udc_read(struct isp1760_udc *udc, u16 reg)
52{
53	return isp1760_read32(udc->regs, reg);
54}
55
56static 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
65static 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
81static 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 */
99static 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. */
105static 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. */
126static 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
153static 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. */
179static 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
245static 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
281static 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
321static 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
401static 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
453static 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
497static 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
523static 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
645static 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
710static 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
771static 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
809static 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
816	return &req->req;
817}
818
819static void isp1760_ep_free_request(struct usb_ep *ep, struct usb_request *_req)
820{
821	struct isp1760_request *req = req_to_udc_req(_req);
822
823	kfree(req);
824}
825
826static int isp1760_ep_queue(struct usb_ep *ep, struct usb_request *_req,
827			    gfp_t gfp_flags)
828{
829	struct isp1760_request *req = req_to_udc_req(_req);
830	struct isp1760_ep *uep = ep_to_udc_ep(ep);
831	struct isp1760_udc *udc = uep->udc;
832	bool complete = false;
833	unsigned long flags;
834	int ret = 0;
835
836	_req->status = -EINPROGRESS;
837	_req->actual = 0;
838
839	spin_lock_irqsave(&udc->lock, flags);
840
841	dev_dbg(udc->isp->dev,
842		"%s: req %p (%u bytes%s) ep %p(0x%02x)\n", __func__, _req,
843		_req->length, _req->zero ? " (zlp)" : "", uep, uep->addr);
844
845	req->ep = uep;
846
847	if (uep->addr == 0) {
848		if (_req->length != udc->ep0_length &&
849		    udc->ep0_state != ISP1760_CTRL_DATA_IN) {
850			dev_dbg(udc->isp->dev,
851				"%s: invalid length %u for req %p\n",
852				__func__, _req->length, req);
853			ret = -EINVAL;
854			goto done;
855		}
856
857		switch (udc->ep0_state) {
858		case ISP1760_CTRL_DATA_IN:
859			dev_dbg(udc->isp->dev, "%s: transmitting req %p\n",
860				__func__, req);
861
862			list_add_tail(&req->queue, &uep->queue);
863			isp1760_udc_transmit(uep, req);
864			break;
865
866		case ISP1760_CTRL_DATA_OUT:
867			list_add_tail(&req->queue, &uep->queue);
868			__isp1760_udc_select_ep(uep, USB_DIR_OUT);
869			isp1760_udc_write(udc, DC_CTRLFUNC, DC_DSEN);
870			break;
871
872		case ISP1760_CTRL_STATUS:
873			complete = true;
874			break;
875
876		default:
877			dev_dbg(udc->isp->dev, "%s: invalid ep0 state\n",
878				__func__);
879			ret = -EINVAL;
880			break;
881		}
882	} else if (uep->desc) {
883		bool empty = list_empty(&uep->queue);
884
885		list_add_tail(&req->queue, &uep->queue);
886		if ((uep->addr & USB_DIR_IN) && !uep->halted && empty)
887			isp1760_udc_transmit(uep, req);
888		else if (!(uep->addr & USB_DIR_IN) && uep->rx_pending)
889			complete = isp1760_udc_receive(uep, req);
890	} else {
891		dev_dbg(udc->isp->dev,
892			"%s: can't queue request to disabled ep%02x\n",
893			__func__, uep->addr);
894		ret = -ESHUTDOWN;
895	}
896
897done:
898	if (ret < 0)
899		req->ep = NULL;
900
901	spin_unlock_irqrestore(&udc->lock, flags);
902
903	if (complete)
904		isp1760_udc_request_complete(uep, req, 0);
905
906	return ret;
907}
908
909static int isp1760_ep_dequeue(struct usb_ep *ep, struct usb_request *_req)
910{
911	struct isp1760_request *req = req_to_udc_req(_req);
912	struct isp1760_ep *uep = ep_to_udc_ep(ep);
913	struct isp1760_udc *udc = uep->udc;
914	unsigned long flags;
915
916	dev_dbg(uep->udc->isp->dev, "%s(ep%02x)\n", __func__, uep->addr);
917
918	spin_lock_irqsave(&udc->lock, flags);
919
920	if (req->ep != uep)
921		req = NULL;
922	else
923		list_del(&req->queue);
924
925	spin_unlock_irqrestore(&udc->lock, flags);
926
927	if (!req)
928		return -EINVAL;
929
930	isp1760_udc_request_complete(uep, req, -ECONNRESET);
931	return 0;
932}
933
934static int __isp1760_ep_set_halt(struct isp1760_ep *uep, bool stall, bool wedge)
935{
936	struct isp1760_udc *udc = uep->udc;
937	int ret;
938
939	if (!uep->addr) {
940		/*
941		 * Halting the control endpoint is only valid as a delayed error
942		 * response to a SETUP packet. Make sure EP0 is in the right
943		 * stage and that the gadget isn't trying to clear the halt
944		 * condition.
945		 */
946		if (WARN_ON(udc->ep0_state == ISP1760_CTRL_SETUP || !stall ||
947			     wedge)) {
948			return -EINVAL;
949		}
950	}
951
952	if (uep->addr && !uep->desc) {
953		dev_dbg(udc->isp->dev, "%s: ep%02x is disabled\n", __func__,
954			uep->addr);
955		return -EINVAL;
956	}
957
958	if (uep->addr & USB_DIR_IN) {
959		/* Refuse to halt IN endpoints with active transfers. */
960		if (!list_empty(&uep->queue)) {
961			dev_dbg(udc->isp->dev,
962				"%s: ep%02x has request pending\n", __func__,
963				uep->addr);
964			return -EAGAIN;
965		}
966	}
967
968	ret = __isp1760_udc_set_halt(uep, stall);
969	if (ret < 0)
970		return ret;
971
972	if (!uep->addr) {
973		/*
974		 * Stalling EP0 completes the control transaction, move back to
975		 * the SETUP state.
976		 */
977		udc->ep0_state = ISP1760_CTRL_SETUP;
978		return 0;
979	}
980
981	if (wedge)
982		uep->wedged = true;
983	else if (!stall)
984		uep->wedged = false;
985
986	return 0;
987}
988
989static int isp1760_ep_set_halt(struct usb_ep *ep, int value)
990{
991	struct isp1760_ep *uep = ep_to_udc_ep(ep);
992	unsigned long flags;
993	int ret;
994
995	dev_dbg(uep->udc->isp->dev, "%s: %s halt on ep%02x\n", __func__,
996		value ? "set" : "clear", uep->addr);
997
998	spin_lock_irqsave(&uep->udc->lock, flags);
999	ret = __isp1760_ep_set_halt(uep, value, false);
1000	spin_unlock_irqrestore(&uep->udc->lock, flags);
1001
1002	return ret;
1003}
1004
1005static int isp1760_ep_set_wedge(struct usb_ep *ep)
1006{
1007	struct isp1760_ep *uep = ep_to_udc_ep(ep);
1008	unsigned long flags;
1009	int ret;
1010
1011	dev_dbg(uep->udc->isp->dev, "%s: set wedge on ep%02x)\n", __func__,
1012		uep->addr);
1013
1014	spin_lock_irqsave(&uep->udc->lock, flags);
1015	ret = __isp1760_ep_set_halt(uep, true, true);
1016	spin_unlock_irqrestore(&uep->udc->lock, flags);
1017
1018	return ret;
1019}
1020
1021static void isp1760_ep_fifo_flush(struct usb_ep *ep)
1022{
1023	struct isp1760_ep *uep = ep_to_udc_ep(ep);
1024	struct isp1760_udc *udc = uep->udc;
1025	unsigned long flags;
1026
1027	spin_lock_irqsave(&udc->lock, flags);
1028
1029	isp1760_udc_select_ep(uep);
1030
1031	/*
1032	 * Set the CLBUF bit twice to flush both buffers in case double
1033	 * buffering is enabled.
1034	 */
1035	isp1760_udc_write(udc, DC_CTRLFUNC, DC_CLBUF);
1036	isp1760_udc_write(udc, DC_CTRLFUNC, DC_CLBUF);
1037
1038	spin_unlock_irqrestore(&udc->lock, flags);
1039}
1040
1041static const struct usb_ep_ops isp1760_ep_ops = {
1042	.enable = isp1760_ep_enable,
1043	.disable = isp1760_ep_disable,
1044	.alloc_request = isp1760_ep_alloc_request,
1045	.free_request = isp1760_ep_free_request,
1046	.queue = isp1760_ep_queue,
1047	.dequeue = isp1760_ep_dequeue,
1048	.set_halt = isp1760_ep_set_halt,
1049	.set_wedge = isp1760_ep_set_wedge,
1050	.fifo_flush = isp1760_ep_fifo_flush,
1051};
1052
1053/* -----------------------------------------------------------------------------
1054 * Device States
1055 */
1056
1057/* Called with the UDC spinlock held. */
1058static void isp1760_udc_connect(struct isp1760_udc *udc)
1059{
1060	usb_gadget_set_state(&udc->gadget, USB_STATE_POWERED);
1061	mod_timer(&udc->vbus_timer, jiffies + ISP1760_VBUS_POLL_INTERVAL);
1062}
1063
1064/* Called with the UDC spinlock held. */
1065static void isp1760_udc_disconnect(struct isp1760_udc *udc)
1066{
1067	if (udc->gadget.state < USB_STATE_POWERED)
1068		return;
1069
1070	dev_dbg(udc->isp->dev, "Device disconnected in state %u\n",
1071		 udc->gadget.state);
1072
1073	udc->gadget.speed = USB_SPEED_UNKNOWN;
1074	usb_gadget_set_state(&udc->gadget, USB_STATE_ATTACHED);
1075
1076	if (udc->driver->disconnect)
1077		udc->driver->disconnect(&udc->gadget);
1078
1079	del_timer(&udc->vbus_timer);
1080
1081	/* TODO Reset all endpoints ? */
1082}
1083
1084static void isp1760_udc_init_hw(struct isp1760_udc *udc)
1085{
1086	/*
1087	 * The device controller currently shares its interrupt with the host
1088	 * controller, the DC_IRQ polarity and signaling mode are ignored. Set
1089	 * the to active-low level-triggered.
1090	 *
1091	 * Configure the control, in and out pipes to generate interrupts on
1092	 * ACK tokens only (and NYET for the out pipe). The default
1093	 * configuration also generates an interrupt on the first NACK token.
1094	 */
1095	isp1760_udc_write(udc, DC_INTCONF, DC_CDBGMOD_ACK | DC_DDBGMODIN_ACK |
1096			  DC_DDBGMODOUT_ACK_NYET);
1097
1098	isp1760_udc_write(udc, DC_INTENABLE, DC_IEPRXTX(7) | DC_IEPRXTX(6) |
1099			  DC_IEPRXTX(5) | DC_IEPRXTX(4) | DC_IEPRXTX(3) |
1100			  DC_IEPRXTX(2) | DC_IEPRXTX(1) | DC_IEPRXTX(0) |
1101			  DC_IEP0SETUP | DC_IEVBUS | DC_IERESM | DC_IESUSP |
1102			  DC_IEHS_STA | DC_IEBRST);
1103
1104	if (udc->connected)
1105		isp1760_set_pullup(udc->isp, true);
1106
1107	isp1760_udc_write(udc, DC_ADDRESS, DC_DEVEN);
1108}
1109
1110static void isp1760_udc_reset(struct isp1760_udc *udc)
1111{
1112	unsigned long flags;
1113
1114	spin_lock_irqsave(&udc->lock, flags);
1115
1116	/*
1117	 * The bus reset has reset most registers to their default value,
1118	 * reinitialize the UDC hardware.
1119	 */
1120	isp1760_udc_init_hw(udc);
1121
1122	udc->ep0_state = ISP1760_CTRL_SETUP;
1123	udc->gadget.speed = USB_SPEED_FULL;
1124
1125	usb_gadget_udc_reset(&udc->gadget, udc->driver);
1126
1127	spin_unlock_irqrestore(&udc->lock, flags);
1128}
1129
1130static void isp1760_udc_suspend(struct isp1760_udc *udc)
1131{
1132	if (udc->gadget.state < USB_STATE_DEFAULT)
1133		return;
1134
1135	if (udc->driver->suspend)
1136		udc->driver->suspend(&udc->gadget);
1137}
1138
1139static void isp1760_udc_resume(struct isp1760_udc *udc)
1140{
1141	if (udc->gadget.state < USB_STATE_DEFAULT)
1142		return;
1143
1144	if (udc->driver->resume)
1145		udc->driver->resume(&udc->gadget);
1146}
1147
1148/* -----------------------------------------------------------------------------
1149 * Gadget Operations
1150 */
1151
1152static int isp1760_udc_get_frame(struct usb_gadget *gadget)
1153{
1154	struct isp1760_udc *udc = gadget_to_udc(gadget);
1155
1156	return isp1760_udc_read(udc, DC_FRAMENUM) & ((1 << 11) - 1);
1157}
1158
1159static int isp1760_udc_wakeup(struct usb_gadget *gadget)
1160{
1161	struct isp1760_udc *udc = gadget_to_udc(gadget);
1162
1163	dev_dbg(udc->isp->dev, "%s\n", __func__);
1164	return -ENOTSUPP;
1165}
1166
1167static int isp1760_udc_set_selfpowered(struct usb_gadget *gadget,
1168				       int is_selfpowered)
1169{
1170	struct isp1760_udc *udc = gadget_to_udc(gadget);
1171
1172	if (is_selfpowered)
1173		udc->devstatus |= 1 << USB_DEVICE_SELF_POWERED;
1174	else
1175		udc->devstatus &= ~(1 << USB_DEVICE_SELF_POWERED);
1176
1177	return 0;
1178}
1179
1180static int isp1760_udc_pullup(struct usb_gadget *gadget, int is_on)
1181{
1182	struct isp1760_udc *udc = gadget_to_udc(gadget);
1183
1184	isp1760_set_pullup(udc->isp, is_on);
1185	udc->connected = is_on;
1186
1187	return 0;
1188}
1189
1190static int isp1760_udc_start(struct usb_gadget *gadget,
1191			     struct usb_gadget_driver *driver)
1192{
1193	struct isp1760_udc *udc = gadget_to_udc(gadget);
1194	unsigned long flags;
1195
1196	/* The hardware doesn't support low speed. */
1197	if (driver->max_speed < USB_SPEED_FULL) {
1198		dev_err(udc->isp->dev, "Invalid gadget driver\n");
1199		return -EINVAL;
1200	}
1201
1202	spin_lock_irqsave(&udc->lock, flags);
1203
1204	if (udc->driver) {
1205		dev_err(udc->isp->dev, "UDC already has a gadget driver\n");
1206		spin_unlock_irqrestore(&udc->lock, flags);
1207		return -EBUSY;
1208	}
1209
1210	udc->driver = driver;
1211
1212	spin_unlock_irqrestore(&udc->lock, flags);
1213
1214	dev_dbg(udc->isp->dev, "starting UDC with driver %s\n",
1215		driver->function);
1216
1217	udc->devstatus = 0;
1218	udc->connected = true;
1219
1220	usb_gadget_set_state(&udc->gadget, USB_STATE_ATTACHED);
1221
1222	/* DMA isn't supported yet, don't enable the DMA clock. */
1223	isp1760_udc_write(udc, DC_MODE, DC_GLINTENA);
1224
1225	isp1760_udc_init_hw(udc);
1226
1227	dev_dbg(udc->isp->dev, "UDC started with driver %s\n",
1228		driver->function);
1229
1230	return 0;
1231}
1232
1233static int isp1760_udc_stop(struct usb_gadget *gadget)
1234{
1235	struct isp1760_udc *udc = gadget_to_udc(gadget);
1236	unsigned long flags;
1237
1238	dev_dbg(udc->isp->dev, "%s\n", __func__);
1239
1240	del_timer_sync(&udc->vbus_timer);
1241
1242	isp1760_udc_write(udc, DC_MODE, 0);
1243
1244	spin_lock_irqsave(&udc->lock, flags);
1245	udc->driver = NULL;
1246	spin_unlock_irqrestore(&udc->lock, flags);
1247
1248	return 0;
1249}
1250
1251static struct usb_gadget_ops isp1760_udc_ops = {
1252	.get_frame = isp1760_udc_get_frame,
1253	.wakeup = isp1760_udc_wakeup,
1254	.set_selfpowered = isp1760_udc_set_selfpowered,
1255	.pullup = isp1760_udc_pullup,
1256	.udc_start = isp1760_udc_start,
1257	.udc_stop = isp1760_udc_stop,
1258};
1259
1260/* -----------------------------------------------------------------------------
1261 * Interrupt Handling
1262 */
1263
1264static irqreturn_t isp1760_udc_irq(int irq, void *dev)
1265{
1266	struct isp1760_udc *udc = dev;
1267	unsigned int i;
1268	u32 status;
1269
1270	status = isp1760_udc_read(udc, DC_INTERRUPT)
1271	       & isp1760_udc_read(udc, DC_INTENABLE);
1272	isp1760_udc_write(udc, DC_INTERRUPT, status);
1273
1274	if (status & DC_IEVBUS) {
1275		dev_dbg(udc->isp->dev, "%s(VBUS)\n", __func__);
1276		/* The VBUS interrupt is only triggered when VBUS appears. */
1277		spin_lock(&udc->lock);
1278		isp1760_udc_connect(udc);
1279		spin_unlock(&udc->lock);
1280	}
1281
1282	if (status & DC_IEBRST) {
1283		dev_dbg(udc->isp->dev, "%s(BRST)\n", __func__);
1284
1285		isp1760_udc_reset(udc);
1286	}
1287
1288	for (i = 0; i <= 7; ++i) {
1289		struct isp1760_ep *ep = &udc->ep[i*2];
1290
1291		if (status & DC_IEPTX(i)) {
1292			dev_dbg(udc->isp->dev, "%s(EPTX%u)\n", __func__, i);
1293			isp1760_ep_tx_complete(ep);
1294		}
1295
1296		if (status & DC_IEPRX(i)) {
1297			dev_dbg(udc->isp->dev, "%s(EPRX%u)\n", __func__, i);
1298			isp1760_ep_rx_ready(i ? ep - 1 : ep);
1299		}
1300	}
1301
1302	if (status & DC_IEP0SETUP) {
1303		dev_dbg(udc->isp->dev, "%s(EP0SETUP)\n", __func__);
1304
1305		isp1760_ep0_setup(udc);
1306	}
1307
1308	if (status & DC_IERESM) {
1309		dev_dbg(udc->isp->dev, "%s(RESM)\n", __func__);
1310		isp1760_udc_resume(udc);
1311	}
1312
1313	if (status & DC_IESUSP) {
1314		dev_dbg(udc->isp->dev, "%s(SUSP)\n", __func__);
1315
1316		spin_lock(&udc->lock);
1317		if (!(isp1760_udc_read(udc, DC_MODE) & DC_VBUSSTAT))
1318			isp1760_udc_disconnect(udc);
1319		else
1320			isp1760_udc_suspend(udc);
1321		spin_unlock(&udc->lock);
1322	}
1323
1324	if (status & DC_IEHS_STA) {
1325		dev_dbg(udc->isp->dev, "%s(HS_STA)\n", __func__);
1326		udc->gadget.speed = USB_SPEED_HIGH;
1327	}
1328
1329	return status ? IRQ_HANDLED : IRQ_NONE;
1330}
1331
1332static void isp1760_udc_vbus_poll(unsigned long data)
1333{
1334	struct isp1760_udc *udc = (struct isp1760_udc *)data;
1335	unsigned long flags;
1336
1337	spin_lock_irqsave(&udc->lock, flags);
1338
1339	if (!(isp1760_udc_read(udc, DC_MODE) & DC_VBUSSTAT))
1340		isp1760_udc_disconnect(udc);
1341	else if (udc->gadget.state >= USB_STATE_POWERED)
1342		mod_timer(&udc->vbus_timer,
1343			  jiffies + ISP1760_VBUS_POLL_INTERVAL);
1344
1345	spin_unlock_irqrestore(&udc->lock, flags);
1346}
1347
1348/* -----------------------------------------------------------------------------
1349 * Registration
1350 */
1351
1352static void isp1760_udc_init_eps(struct isp1760_udc *udc)
1353{
1354	unsigned int i;
1355
1356	INIT_LIST_HEAD(&udc->gadget.ep_list);
1357
1358	for (i = 0; i < ARRAY_SIZE(udc->ep); ++i) {
1359		struct isp1760_ep *ep = &udc->ep[i];
1360		unsigned int ep_num = (i + 1) / 2;
1361		bool is_in = !(i & 1);
1362
1363		ep->udc = udc;
1364
1365		INIT_LIST_HEAD(&ep->queue);
1366
1367		ep->addr = (ep_num && is_in ? USB_DIR_IN : USB_DIR_OUT)
1368			 | ep_num;
1369		ep->desc = NULL;
1370
1371		sprintf(ep->name, "ep%u%s", ep_num,
1372			ep_num ? (is_in ? "in" : "out") : "");
1373
1374		ep->ep.ops = &isp1760_ep_ops;
1375		ep->ep.name = ep->name;
1376
1377		/*
1378		 * Hardcode the maximum packet sizes for now, to 64 bytes for
1379		 * the control endpoint and 512 bytes for all other endpoints.
1380		 * This fits in the 8kB FIFO without double-buffering.
1381		 */
1382		if (ep_num == 0) {
1383			ep->ep.maxpacket = 64;
1384			ep->maxpacket = 64;
1385			udc->gadget.ep0 = &ep->ep;
1386		} else {
1387			ep->ep.maxpacket = 512;
1388			ep->maxpacket = 0;
1389			list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
1390		}
1391	}
1392}
1393
1394static int isp1760_udc_init(struct isp1760_udc *udc)
1395{
1396	u16 scratch;
1397	u32 chipid;
1398
1399	/*
1400	 * Check that the controller is present by writing to the scratch
1401	 * register, modifying the bus pattern by reading from the chip ID
1402	 * register, and reading the scratch register value back. The chip ID
1403	 * and scratch register contents must match the expected values.
1404	 */
1405	isp1760_udc_write(udc, DC_SCRATCH, 0xbabe);
1406	chipid = isp1760_udc_read(udc, DC_CHIPID);
1407	scratch = isp1760_udc_read(udc, DC_SCRATCH);
1408
1409	if (scratch != 0xbabe) {
1410		dev_err(udc->isp->dev,
1411			"udc: scratch test failed (0x%04x/0x%08x)\n",
1412			scratch, chipid);
1413		return -ENODEV;
1414	}
1415
1416	if (chipid != 0x00011582 && chipid != 0x00158210) {
1417		dev_err(udc->isp->dev, "udc: invalid chip ID 0x%08x\n", chipid);
1418		return -ENODEV;
1419	}
1420
1421	/* Reset the device controller. */
1422	isp1760_udc_write(udc, DC_MODE, DC_SFRESET);
1423	usleep_range(10000, 11000);
1424	isp1760_udc_write(udc, DC_MODE, 0);
1425	usleep_range(10000, 11000);
1426
1427	return 0;
1428}
1429
1430int isp1760_udc_register(struct isp1760_device *isp, int irq,
1431			 unsigned long irqflags)
1432{
1433	struct isp1760_udc *udc = &isp->udc;
1434	const char *devname;
1435	int ret;
1436
1437	udc->irq = -1;
1438	udc->isp = isp;
1439	udc->regs = isp->regs;
1440
1441	spin_lock_init(&udc->lock);
1442	setup_timer(&udc->vbus_timer, isp1760_udc_vbus_poll,
1443		    (unsigned long)udc);
1444
1445	ret = isp1760_udc_init(udc);
1446	if (ret < 0)
1447		return ret;
1448
1449	devname = dev_name(isp->dev);
1450	udc->irqname = kmalloc(strlen(devname) + 7, GFP_KERNEL);
1451	if (!udc->irqname)
1452		return -ENOMEM;
1453
1454	sprintf(udc->irqname, "%s (udc)", devname);
1455
1456	ret = request_irq(irq, isp1760_udc_irq, IRQF_SHARED | irqflags,
1457			  udc->irqname, udc);
1458	if (ret < 0)
1459		goto error;
1460
1461	udc->irq = irq;
1462
1463	/*
1464	 * Initialize the gadget static fields and register its device. Gadget
1465	 * fields that vary during the life time of the gadget are initialized
1466	 * by the UDC core.
1467	 */
1468	udc->gadget.ops = &isp1760_udc_ops;
1469	udc->gadget.speed = USB_SPEED_UNKNOWN;
1470	udc->gadget.max_speed = USB_SPEED_HIGH;
1471	udc->gadget.name = "isp1761_udc";
1472
1473	isp1760_udc_init_eps(udc);
1474
1475	ret = usb_add_gadget_udc(isp->dev, &udc->gadget);
1476	if (ret < 0)
1477		goto error;
1478
1479	return 0;
1480
1481error:
1482	if (udc->irq >= 0)
1483		free_irq(udc->irq, udc);
1484	kfree(udc->irqname);
1485
1486	return ret;
1487}
1488
1489void isp1760_udc_unregister(struct isp1760_device *isp)
1490{
1491	struct isp1760_udc *udc = &isp->udc;
1492
1493	if (!udc->isp)
1494		return;
1495
1496	usb_del_gadget_udc(&udc->gadget);
1497
1498	free_irq(udc->irq, udc);
1499	kfree(udc->irqname);
1500}
1501