xref: /openbmc/linux/drivers/usb/gadget/udc/goku_udc.c (revision 94d964e5)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Toshiba TC86C001 ("Goku-S") USB Device Controller driver
4  *
5  * Copyright (C) 2000-2002 Lineo
6  *      by Stuart Lynne, Tom Rushworth, and Bruce Balden
7  * Copyright (C) 2002 Toshiba Corporation
8  * Copyright (C) 2003 MontaVista Software (source@mvista.com)
9  */
10 
11 /*
12  * This device has ep0 and three semi-configurable bulk/interrupt endpoints.
13  *
14  *  - Endpoint numbering is fixed: ep{1,2,3}-bulk
15  *  - Gadget drivers can choose ep maxpacket (8/16/32/64)
16  *  - Gadget drivers can choose direction (IN, OUT)
17  *  - DMA works with ep1 (OUT transfers) and ep2 (IN transfers).
18  */
19 
20 // #define	VERBOSE		/* extra debug messages (success too) */
21 // #define	USB_TRACE	/* packet-level success messages */
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/pci.h>
26 #include <linux/delay.h>
27 #include <linux/ioport.h>
28 #include <linux/slab.h>
29 #include <linux/errno.h>
30 #include <linux/timer.h>
31 #include <linux/list.h>
32 #include <linux/interrupt.h>
33 #include <linux/proc_fs.h>
34 #include <linux/seq_file.h>
35 #include <linux/device.h>
36 #include <linux/usb/ch9.h>
37 #include <linux/usb/gadget.h>
38 #include <linux/prefetch.h>
39 
40 #include <asm/byteorder.h>
41 #include <asm/io.h>
42 #include <asm/irq.h>
43 #include <asm/unaligned.h>
44 
45 
46 #include "goku_udc.h"
47 
48 #define	DRIVER_DESC		"TC86C001 USB Device Controller"
49 #define	DRIVER_VERSION		"30-Oct 2003"
50 
51 static const char driver_name [] = "goku_udc";
52 static const char driver_desc [] = DRIVER_DESC;
53 
54 MODULE_AUTHOR("source@mvista.com");
55 MODULE_DESCRIPTION(DRIVER_DESC);
56 MODULE_LICENSE("GPL");
57 
58 
59 /*
60  * IN dma behaves ok under testing, though the IN-dma abort paths don't
61  * seem to behave quite as expected.  Used by default.
62  *
63  * OUT dma documents design problems handling the common "short packet"
64  * transfer termination policy; it couldn't be enabled by default, even
65  * if the OUT-dma abort problems had a resolution.
66  */
67 static unsigned use_dma = 1;
68 
69 #if 0
70 //#include <linux/moduleparam.h>
71 /* "modprobe goku_udc use_dma=1" etc
72  *	0 to disable dma
73  *	1 to use IN dma only (normal operation)
74  *	2 to use IN and OUT dma
75  */
76 module_param(use_dma, uint, S_IRUGO);
77 #endif
78 
79 /*-------------------------------------------------------------------------*/
80 
81 static void nuke(struct goku_ep *, int status);
82 
83 static inline void
84 command(struct goku_udc_regs __iomem *regs, int command, unsigned epnum)
85 {
86 	writel(COMMAND_EP(epnum) | command, &regs->Command);
87 	udelay(300);
88 }
89 
90 static int
91 goku_ep_enable(struct usb_ep *_ep, const struct usb_endpoint_descriptor *desc)
92 {
93 	struct goku_udc	*dev;
94 	struct goku_ep	*ep;
95 	u32		mode;
96 	u16		max;
97 	unsigned long	flags;
98 
99 	ep = container_of(_ep, struct goku_ep, ep);
100 	if (!_ep || !desc
101 			|| desc->bDescriptorType != USB_DT_ENDPOINT)
102 		return -EINVAL;
103 	dev = ep->dev;
104 	if (ep == &dev->ep[0])
105 		return -EINVAL;
106 	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
107 		return -ESHUTDOWN;
108 	if (ep->num != usb_endpoint_num(desc))
109 		return -EINVAL;
110 
111 	switch (usb_endpoint_type(desc)) {
112 	case USB_ENDPOINT_XFER_BULK:
113 	case USB_ENDPOINT_XFER_INT:
114 		break;
115 	default:
116 		return -EINVAL;
117 	}
118 
119 	if ((readl(ep->reg_status) & EPxSTATUS_EP_MASK)
120 			!= EPxSTATUS_EP_INVALID)
121 		return -EBUSY;
122 
123 	/* enabling the no-toggle interrupt mode would need an api hook */
124 	mode = 0;
125 	max = get_unaligned_le16(&desc->wMaxPacketSize);
126 	switch (max) {
127 	case 64:
128 		mode++;
129 		fallthrough;
130 	case 32:
131 		mode++;
132 		fallthrough;
133 	case 16:
134 		mode++;
135 		fallthrough;
136 	case 8:
137 		mode <<= 3;
138 		break;
139 	default:
140 		return -EINVAL;
141 	}
142 	mode |= 2 << 1;		/* bulk, or intr-with-toggle */
143 
144 	/* ep1/ep2 dma direction is chosen early; it works in the other
145 	 * direction, with pio.  be cautious with out-dma.
146 	 */
147 	ep->is_in = usb_endpoint_dir_in(desc);
148 	if (ep->is_in) {
149 		mode |= 1;
150 		ep->dma = (use_dma != 0) && (ep->num == UDC_MSTRD_ENDPOINT);
151 	} else {
152 		ep->dma = (use_dma == 2) && (ep->num == UDC_MSTWR_ENDPOINT);
153 		if (ep->dma)
154 			DBG(dev, "%s out-dma hides short packets\n",
155 				ep->ep.name);
156 	}
157 
158 	spin_lock_irqsave(&ep->dev->lock, flags);
159 
160 	/* ep1 and ep2 can do double buffering and/or dma */
161 	if (ep->num < 3) {
162 		struct goku_udc_regs __iomem	*regs = ep->dev->regs;
163 		u32				tmp;
164 
165 		/* double buffer except (for now) with pio in */
166 		tmp = ((ep->dma || !ep->is_in)
167 				? 0x10	/* double buffered */
168 				: 0x11	/* single buffer */
169 			) << ep->num;
170 		tmp |= readl(&regs->EPxSingle);
171 		writel(tmp, &regs->EPxSingle);
172 
173 		tmp = (ep->dma ? 0x10/*dma*/ : 0x11/*pio*/) << ep->num;
174 		tmp |= readl(&regs->EPxBCS);
175 		writel(tmp, &regs->EPxBCS);
176 	}
177 	writel(mode, ep->reg_mode);
178 	command(ep->dev->regs, COMMAND_RESET, ep->num);
179 	ep->ep.maxpacket = max;
180 	ep->stopped = 0;
181 	ep->ep.desc = desc;
182 	spin_unlock_irqrestore(&ep->dev->lock, flags);
183 
184 	DBG(dev, "enable %s %s %s maxpacket %u\n", ep->ep.name,
185 		ep->is_in ? "IN" : "OUT",
186 		ep->dma ? "dma" : "pio",
187 		max);
188 
189 	return 0;
190 }
191 
192 static void ep_reset(struct goku_udc_regs __iomem *regs, struct goku_ep *ep)
193 {
194 	struct goku_udc		*dev = ep->dev;
195 
196 	if (regs) {
197 		command(regs, COMMAND_INVALID, ep->num);
198 		if (ep->num) {
199 			if (ep->num == UDC_MSTWR_ENDPOINT)
200 				dev->int_enable &= ~(INT_MSTWREND
201 							|INT_MSTWRTMOUT);
202 			else if (ep->num == UDC_MSTRD_ENDPOINT)
203 				dev->int_enable &= ~INT_MSTRDEND;
204 			dev->int_enable &= ~INT_EPxDATASET (ep->num);
205 		} else
206 			dev->int_enable &= ~INT_EP0;
207 		writel(dev->int_enable, &regs->int_enable);
208 		readl(&regs->int_enable);
209 		if (ep->num < 3) {
210 			struct goku_udc_regs __iomem	*r = ep->dev->regs;
211 			u32				tmp;
212 
213 			tmp = readl(&r->EPxSingle);
214 			tmp &= ~(0x11 << ep->num);
215 			writel(tmp, &r->EPxSingle);
216 
217 			tmp = readl(&r->EPxBCS);
218 			tmp &= ~(0x11 << ep->num);
219 			writel(tmp, &r->EPxBCS);
220 		}
221 		/* reset dma in case we're still using it */
222 		if (ep->dma) {
223 			u32	master;
224 
225 			master = readl(&regs->dma_master) & MST_RW_BITS;
226 			if (ep->num == UDC_MSTWR_ENDPOINT) {
227 				master &= ~MST_W_BITS;
228 				master |= MST_WR_RESET;
229 			} else {
230 				master &= ~MST_R_BITS;
231 				master |= MST_RD_RESET;
232 			}
233 			writel(master, &regs->dma_master);
234 		}
235 	}
236 
237 	usb_ep_set_maxpacket_limit(&ep->ep, MAX_FIFO_SIZE);
238 	ep->ep.desc = NULL;
239 	ep->stopped = 1;
240 	ep->irqs = 0;
241 	ep->dma = 0;
242 }
243 
244 static int goku_ep_disable(struct usb_ep *_ep)
245 {
246 	struct goku_ep	*ep;
247 	struct goku_udc	*dev;
248 	unsigned long	flags;
249 
250 	ep = container_of(_ep, struct goku_ep, ep);
251 	if (!_ep || !ep->ep.desc)
252 		return -ENODEV;
253 	dev = ep->dev;
254 	if (dev->ep0state == EP0_SUSPEND)
255 		return -EBUSY;
256 
257 	VDBG(dev, "disable %s\n", _ep->name);
258 
259 	spin_lock_irqsave(&dev->lock, flags);
260 	nuke(ep, -ESHUTDOWN);
261 	ep_reset(dev->regs, ep);
262 	spin_unlock_irqrestore(&dev->lock, flags);
263 
264 	return 0;
265 }
266 
267 /*-------------------------------------------------------------------------*/
268 
269 static struct usb_request *
270 goku_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
271 {
272 	struct goku_request	*req;
273 
274 	if (!_ep)
275 		return NULL;
276 	req = kzalloc(sizeof *req, gfp_flags);
277 	if (!req)
278 		return NULL;
279 
280 	INIT_LIST_HEAD(&req->queue);
281 	return &req->req;
282 }
283 
284 static void
285 goku_free_request(struct usb_ep *_ep, struct usb_request *_req)
286 {
287 	struct goku_request	*req;
288 
289 	if (!_ep || !_req)
290 		return;
291 
292 	req = container_of(_req, struct goku_request, req);
293 	WARN_ON(!list_empty(&req->queue));
294 	kfree(req);
295 }
296 
297 /*-------------------------------------------------------------------------*/
298 
299 static void
300 done(struct goku_ep *ep, struct goku_request *req, int status)
301 {
302 	struct goku_udc		*dev;
303 	unsigned		stopped = ep->stopped;
304 
305 	list_del_init(&req->queue);
306 
307 	if (likely(req->req.status == -EINPROGRESS))
308 		req->req.status = status;
309 	else
310 		status = req->req.status;
311 
312 	dev = ep->dev;
313 
314 	if (ep->dma)
315 		usb_gadget_unmap_request(&dev->gadget, &req->req, ep->is_in);
316 
317 #ifndef USB_TRACE
318 	if (status && status != -ESHUTDOWN)
319 #endif
320 		VDBG(dev, "complete %s req %p stat %d len %u/%u\n",
321 			ep->ep.name, &req->req, status,
322 			req->req.actual, req->req.length);
323 
324 	/* don't modify queue heads during completion callback */
325 	ep->stopped = 1;
326 	spin_unlock(&dev->lock);
327 	usb_gadget_giveback_request(&ep->ep, &req->req);
328 	spin_lock(&dev->lock);
329 	ep->stopped = stopped;
330 }
331 
332 /*-------------------------------------------------------------------------*/
333 
334 static inline int
335 write_packet(u32 __iomem *fifo, u8 *buf, struct goku_request *req, unsigned max)
336 {
337 	unsigned	length, count;
338 
339 	length = min(req->req.length - req->req.actual, max);
340 	req->req.actual += length;
341 
342 	count = length;
343 	while (likely(count--))
344 		writel(*buf++, fifo);
345 	return length;
346 }
347 
348 // return:  0 = still running, 1 = completed, negative = errno
349 static int write_fifo(struct goku_ep *ep, struct goku_request *req)
350 {
351 	struct goku_udc	*dev = ep->dev;
352 	u32		tmp;
353 	u8		*buf;
354 	unsigned	count;
355 	int		is_last;
356 
357 	tmp = readl(&dev->regs->DataSet);
358 	buf = req->req.buf + req->req.actual;
359 	prefetch(buf);
360 
361 	dev = ep->dev;
362 	if (unlikely(ep->num == 0 && dev->ep0state != EP0_IN))
363 		return -EL2HLT;
364 
365 	/* NOTE:  just single-buffered PIO-IN for now.  */
366 	if (unlikely((tmp & DATASET_A(ep->num)) != 0))
367 		return 0;
368 
369 	/* clear our "packet available" irq */
370 	if (ep->num != 0)
371 		writel(~INT_EPxDATASET(ep->num), &dev->regs->int_status);
372 
373 	count = write_packet(ep->reg_fifo, buf, req, ep->ep.maxpacket);
374 
375 	/* last packet often short (sometimes a zlp, especially on ep0) */
376 	if (unlikely(count != ep->ep.maxpacket)) {
377 		writel(~(1<<ep->num), &dev->regs->EOP);
378 		if (ep->num == 0) {
379 			dev->ep[0].stopped = 1;
380 			dev->ep0state = EP0_STATUS;
381 		}
382 		is_last = 1;
383 	} else {
384 		if (likely(req->req.length != req->req.actual)
385 				|| req->req.zero)
386 			is_last = 0;
387 		else
388 			is_last = 1;
389 	}
390 #if 0		/* printk seemed to trash is_last...*/
391 //#ifdef USB_TRACE
392 	VDBG(dev, "wrote %s %u bytes%s IN %u left %p\n",
393 		ep->ep.name, count, is_last ? "/last" : "",
394 		req->req.length - req->req.actual, req);
395 #endif
396 
397 	/* requests complete when all IN data is in the FIFO,
398 	 * or sometimes later, if a zlp was needed.
399 	 */
400 	if (is_last) {
401 		done(ep, req, 0);
402 		return 1;
403 	}
404 
405 	return 0;
406 }
407 
408 static int read_fifo(struct goku_ep *ep, struct goku_request *req)
409 {
410 	struct goku_udc_regs __iomem	*regs;
411 	u32				size, set;
412 	u8				*buf;
413 	unsigned			bufferspace, is_short, dbuff;
414 
415 	regs = ep->dev->regs;
416 top:
417 	buf = req->req.buf + req->req.actual;
418 	prefetchw(buf);
419 
420 	if (unlikely(ep->num == 0 && ep->dev->ep0state != EP0_OUT))
421 		return -EL2HLT;
422 
423 	dbuff = (ep->num == 1 || ep->num == 2);
424 	do {
425 		/* ack dataset irq matching the status we'll handle */
426 		if (ep->num != 0)
427 			writel(~INT_EPxDATASET(ep->num), &regs->int_status);
428 
429 		set = readl(&regs->DataSet) & DATASET_AB(ep->num);
430 		size = readl(&regs->EPxSizeLA[ep->num]);
431 		bufferspace = req->req.length - req->req.actual;
432 
433 		/* usually do nothing without an OUT packet */
434 		if (likely(ep->num != 0 || bufferspace != 0)) {
435 			if (unlikely(set == 0))
436 				break;
437 			/* use ep1/ep2 double-buffering for OUT */
438 			if (!(size & PACKET_ACTIVE))
439 				size = readl(&regs->EPxSizeLB[ep->num]);
440 			if (!(size & PACKET_ACTIVE))	/* "can't happen" */
441 				break;
442 			size &= DATASIZE;	/* EPxSizeH == 0 */
443 
444 		/* ep0out no-out-data case for set_config, etc */
445 		} else
446 			size = 0;
447 
448 		/* read all bytes from this packet */
449 		req->req.actual += size;
450 		is_short = (size < ep->ep.maxpacket);
451 #ifdef USB_TRACE
452 		VDBG(ep->dev, "read %s %u bytes%s OUT req %p %u/%u\n",
453 			ep->ep.name, size, is_short ? "/S" : "",
454 			req, req->req.actual, req->req.length);
455 #endif
456 		while (likely(size-- != 0)) {
457 			u8	byte = (u8) readl(ep->reg_fifo);
458 
459 			if (unlikely(bufferspace == 0)) {
460 				/* this happens when the driver's buffer
461 				 * is smaller than what the host sent.
462 				 * discard the extra data in this packet.
463 				 */
464 				if (req->req.status != -EOVERFLOW)
465 					DBG(ep->dev, "%s overflow %u\n",
466 						ep->ep.name, size);
467 				req->req.status = -EOVERFLOW;
468 			} else {
469 				*buf++ = byte;
470 				bufferspace--;
471 			}
472 		}
473 
474 		/* completion */
475 		if (unlikely(is_short || req->req.actual == req->req.length)) {
476 			if (unlikely(ep->num == 0)) {
477 				/* non-control endpoints now usable? */
478 				if (ep->dev->req_config)
479 					writel(ep->dev->configured
480 							? USBSTATE_CONFIGURED
481 							: 0,
482 						&regs->UsbState);
483 				/* ep0out status stage */
484 				writel(~(1<<0), &regs->EOP);
485 				ep->stopped = 1;
486 				ep->dev->ep0state = EP0_STATUS;
487 			}
488 			done(ep, req, 0);
489 
490 			/* empty the second buffer asap */
491 			if (dbuff && !list_empty(&ep->queue)) {
492 				req = list_entry(ep->queue.next,
493 						struct goku_request, queue);
494 				goto top;
495 			}
496 			return 1;
497 		}
498 	} while (dbuff);
499 	return 0;
500 }
501 
502 static inline void
503 pio_irq_enable(struct goku_udc *dev,
504 		struct goku_udc_regs __iomem *regs, int epnum)
505 {
506 	dev->int_enable |= INT_EPxDATASET (epnum);
507 	writel(dev->int_enable, &regs->int_enable);
508 	/* write may still be posted */
509 }
510 
511 static inline void
512 pio_irq_disable(struct goku_udc *dev,
513 		struct goku_udc_regs __iomem *regs, int epnum)
514 {
515 	dev->int_enable &= ~INT_EPxDATASET (epnum);
516 	writel(dev->int_enable, &regs->int_enable);
517 	/* write may still be posted */
518 }
519 
520 static inline void
521 pio_advance(struct goku_ep *ep)
522 {
523 	struct goku_request	*req;
524 
525 	if (unlikely(list_empty (&ep->queue)))
526 		return;
527 	req = list_entry(ep->queue.next, struct goku_request, queue);
528 	(ep->is_in ? write_fifo : read_fifo)(ep, req);
529 }
530 
531 
532 /*-------------------------------------------------------------------------*/
533 
534 // return:  0 = q running, 1 = q stopped, negative = errno
535 static int start_dma(struct goku_ep *ep, struct goku_request *req)
536 {
537 	struct goku_udc_regs __iomem	*regs = ep->dev->regs;
538 	u32				master;
539 	u32				start = req->req.dma;
540 	u32				end = start + req->req.length - 1;
541 
542 	master = readl(&regs->dma_master) & MST_RW_BITS;
543 
544 	/* re-init the bits affecting IN dma; careful with zlps */
545 	if (likely(ep->is_in)) {
546 		if (unlikely(master & MST_RD_ENA)) {
547 			DBG (ep->dev, "start, IN active dma %03x!!\n",
548 				master);
549 //			return -EL2HLT;
550 		}
551 		writel(end, &regs->in_dma_end);
552 		writel(start, &regs->in_dma_start);
553 
554 		master &= ~MST_R_BITS;
555 		if (unlikely(req->req.length == 0))
556 			master |= MST_RD_ENA | MST_RD_EOPB;
557 		else if ((req->req.length % ep->ep.maxpacket) != 0
558 					|| req->req.zero)
559 			master |= MST_RD_ENA | MST_EOPB_ENA;
560 		else
561 			master |= MST_RD_ENA | MST_EOPB_DIS;
562 
563 		ep->dev->int_enable |= INT_MSTRDEND;
564 
565 	/* Goku DMA-OUT merges short packets, which plays poorly with
566 	 * protocols where short packets mark the transfer boundaries.
567 	 * The chip supports a nonstandard policy with INT_MSTWRTMOUT,
568 	 * ending transfers after 3 SOFs; we don't turn it on.
569 	 */
570 	} else {
571 		if (unlikely(master & MST_WR_ENA)) {
572 			DBG (ep->dev, "start, OUT active dma %03x!!\n",
573 				master);
574 //			return -EL2HLT;
575 		}
576 		writel(end, &regs->out_dma_end);
577 		writel(start, &regs->out_dma_start);
578 
579 		master &= ~MST_W_BITS;
580 		master |= MST_WR_ENA | MST_TIMEOUT_DIS;
581 
582 		ep->dev->int_enable |= INT_MSTWREND|INT_MSTWRTMOUT;
583 	}
584 
585 	writel(master, &regs->dma_master);
586 	writel(ep->dev->int_enable, &regs->int_enable);
587 	return 0;
588 }
589 
590 static void dma_advance(struct goku_udc *dev, struct goku_ep *ep)
591 {
592 	struct goku_request		*req;
593 	struct goku_udc_regs __iomem	*regs = ep->dev->regs;
594 	u32				master;
595 
596 	master = readl(&regs->dma_master);
597 
598 	if (unlikely(list_empty(&ep->queue))) {
599 stop:
600 		if (ep->is_in)
601 			dev->int_enable &= ~INT_MSTRDEND;
602 		else
603 			dev->int_enable &= ~(INT_MSTWREND|INT_MSTWRTMOUT);
604 		writel(dev->int_enable, &regs->int_enable);
605 		return;
606 	}
607 	req = list_entry(ep->queue.next, struct goku_request, queue);
608 
609 	/* normal hw dma completion (not abort) */
610 	if (likely(ep->is_in)) {
611 		if (unlikely(master & MST_RD_ENA))
612 			return;
613 		req->req.actual = readl(&regs->in_dma_current);
614 	} else {
615 		if (unlikely(master & MST_WR_ENA))
616 			return;
617 
618 		/* hardware merges short packets, and also hides packet
619 		 * overruns.  a partial packet MAY be in the fifo here.
620 		 */
621 		req->req.actual = readl(&regs->out_dma_current);
622 	}
623 	req->req.actual -= req->req.dma;
624 	req->req.actual++;
625 
626 #ifdef USB_TRACE
627 	VDBG(dev, "done %s %s dma, %u/%u bytes, req %p\n",
628 		ep->ep.name, ep->is_in ? "IN" : "OUT",
629 		req->req.actual, req->req.length, req);
630 #endif
631 	done(ep, req, 0);
632 	if (list_empty(&ep->queue))
633 		goto stop;
634 	req = list_entry(ep->queue.next, struct goku_request, queue);
635 	(void) start_dma(ep, req);
636 }
637 
638 static void abort_dma(struct goku_ep *ep, int status)
639 {
640 	struct goku_udc_regs __iomem	*regs = ep->dev->regs;
641 	struct goku_request		*req;
642 	u32				curr, master;
643 
644 	/* NAK future host requests, hoping the implicit delay lets the
645 	 * dma engine finish reading (or writing) its latest packet and
646 	 * empty the dma buffer (up to 16 bytes).
647 	 *
648 	 * This avoids needing to clean up a partial packet in the fifo;
649 	 * we can't do that for IN without side effects to HALT and TOGGLE.
650 	 */
651 	command(regs, COMMAND_FIFO_DISABLE, ep->num);
652 	req = list_entry(ep->queue.next, struct goku_request, queue);
653 	master = readl(&regs->dma_master) & MST_RW_BITS;
654 
655 	/* FIXME using these resets isn't usably documented. this may
656 	 * not work unless it's followed by disabling the endpoint.
657 	 *
658 	 * FIXME the OUT reset path doesn't even behave consistently.
659 	 */
660 	if (ep->is_in) {
661 		if (unlikely((readl(&regs->dma_master) & MST_RD_ENA) == 0))
662 			goto finished;
663 		curr = readl(&regs->in_dma_current);
664 
665 		writel(curr, &regs->in_dma_end);
666 		writel(curr, &regs->in_dma_start);
667 
668 		master &= ~MST_R_BITS;
669 		master |= MST_RD_RESET;
670 		writel(master, &regs->dma_master);
671 
672 		if (readl(&regs->dma_master) & MST_RD_ENA)
673 			DBG(ep->dev, "IN dma active after reset!\n");
674 
675 	} else {
676 		if (unlikely((readl(&regs->dma_master) & MST_WR_ENA) == 0))
677 			goto finished;
678 		curr = readl(&regs->out_dma_current);
679 
680 		writel(curr, &regs->out_dma_end);
681 		writel(curr, &regs->out_dma_start);
682 
683 		master &= ~MST_W_BITS;
684 		master |= MST_WR_RESET;
685 		writel(master, &regs->dma_master);
686 
687 		if (readl(&regs->dma_master) & MST_WR_ENA)
688 			DBG(ep->dev, "OUT dma active after reset!\n");
689 	}
690 	req->req.actual = (curr - req->req.dma) + 1;
691 	req->req.status = status;
692 
693 	VDBG(ep->dev, "%s %s %s %d/%d\n", __func__, ep->ep.name,
694 		ep->is_in ? "IN" : "OUT",
695 		req->req.actual, req->req.length);
696 
697 	command(regs, COMMAND_FIFO_ENABLE, ep->num);
698 
699 	return;
700 
701 finished:
702 	/* dma already completed; no abort needed */
703 	command(regs, COMMAND_FIFO_ENABLE, ep->num);
704 	req->req.actual = req->req.length;
705 	req->req.status = 0;
706 }
707 
708 /*-------------------------------------------------------------------------*/
709 
710 static int
711 goku_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
712 {
713 	struct goku_request	*req;
714 	struct goku_ep		*ep;
715 	struct goku_udc		*dev;
716 	unsigned long		flags;
717 	int			status;
718 
719 	/* always require a cpu-view buffer so pio works */
720 	req = container_of(_req, struct goku_request, req);
721 	if (unlikely(!_req || !_req->complete
722 			|| !_req->buf || !list_empty(&req->queue)))
723 		return -EINVAL;
724 	ep = container_of(_ep, struct goku_ep, ep);
725 	if (unlikely(!_ep || (!ep->ep.desc && ep->num != 0)))
726 		return -EINVAL;
727 	dev = ep->dev;
728 	if (unlikely(!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN))
729 		return -ESHUTDOWN;
730 
731 	/* can't touch registers when suspended */
732 	if (dev->ep0state == EP0_SUSPEND)
733 		return -EBUSY;
734 
735 	/* set up dma mapping in case the caller didn't */
736 	if (ep->dma) {
737 		status = usb_gadget_map_request(&dev->gadget, &req->req,
738 				ep->is_in);
739 		if (status)
740 			return status;
741 	}
742 
743 #ifdef USB_TRACE
744 	VDBG(dev, "%s queue req %p, len %u buf %p\n",
745 			_ep->name, _req, _req->length, _req->buf);
746 #endif
747 
748 	spin_lock_irqsave(&dev->lock, flags);
749 
750 	_req->status = -EINPROGRESS;
751 	_req->actual = 0;
752 
753 	/* for ep0 IN without premature status, zlp is required and
754 	 * writing EOP starts the status stage (OUT).
755 	 */
756 	if (unlikely(ep->num == 0 && ep->is_in))
757 		_req->zero = 1;
758 
759 	/* kickstart this i/o queue? */
760 	status = 0;
761 	if (list_empty(&ep->queue) && likely(!ep->stopped)) {
762 		/* dma:  done after dma completion IRQ (or error)
763 		 * pio:  done after last fifo operation
764 		 */
765 		if (ep->dma)
766 			status = start_dma(ep, req);
767 		else
768 			status = (ep->is_in ? write_fifo : read_fifo)(ep, req);
769 
770 		if (unlikely(status != 0)) {
771 			if (status > 0)
772 				status = 0;
773 			req = NULL;
774 		}
775 
776 	} /* else pio or dma irq handler advances the queue. */
777 
778 	if (likely(req != NULL))
779 		list_add_tail(&req->queue, &ep->queue);
780 
781 	if (likely(!list_empty(&ep->queue))
782 			&& likely(ep->num != 0)
783 			&& !ep->dma
784 			&& !(dev->int_enable & INT_EPxDATASET (ep->num)))
785 		pio_irq_enable(dev, dev->regs, ep->num);
786 
787 	spin_unlock_irqrestore(&dev->lock, flags);
788 
789 	/* pci writes may still be posted */
790 	return status;
791 }
792 
793 /* dequeue ALL requests */
794 static void nuke(struct goku_ep *ep, int status)
795 {
796 	struct goku_request	*req;
797 
798 	ep->stopped = 1;
799 	if (list_empty(&ep->queue))
800 		return;
801 	if (ep->dma)
802 		abort_dma(ep, status);
803 	while (!list_empty(&ep->queue)) {
804 		req = list_entry(ep->queue.next, struct goku_request, queue);
805 		done(ep, req, status);
806 	}
807 }
808 
809 /* dequeue JUST ONE request */
810 static int goku_dequeue(struct usb_ep *_ep, struct usb_request *_req)
811 {
812 	struct goku_request	*req;
813 	struct goku_ep		*ep;
814 	struct goku_udc		*dev;
815 	unsigned long		flags;
816 
817 	ep = container_of(_ep, struct goku_ep, ep);
818 	if (!_ep || !_req || (!ep->ep.desc && ep->num != 0))
819 		return -EINVAL;
820 	dev = ep->dev;
821 	if (!dev->driver)
822 		return -ESHUTDOWN;
823 
824 	/* we can't touch (dma) registers when suspended */
825 	if (dev->ep0state == EP0_SUSPEND)
826 		return -EBUSY;
827 
828 	VDBG(dev, "%s %s %s %s %p\n", __func__, _ep->name,
829 		ep->is_in ? "IN" : "OUT",
830 		ep->dma ? "dma" : "pio",
831 		_req);
832 
833 	spin_lock_irqsave(&dev->lock, flags);
834 
835 	/* make sure it's actually queued on this endpoint */
836 	list_for_each_entry (req, &ep->queue, queue) {
837 		if (&req->req == _req)
838 			break;
839 	}
840 	if (&req->req != _req) {
841 		spin_unlock_irqrestore (&dev->lock, flags);
842 		return -EINVAL;
843 	}
844 
845 	if (ep->dma && ep->queue.next == &req->queue && !ep->stopped) {
846 		abort_dma(ep, -ECONNRESET);
847 		done(ep, req, -ECONNRESET);
848 		dma_advance(dev, ep);
849 	} else if (!list_empty(&req->queue))
850 		done(ep, req, -ECONNRESET);
851 	else
852 		req = NULL;
853 	spin_unlock_irqrestore(&dev->lock, flags);
854 
855 	return req ? 0 : -EOPNOTSUPP;
856 }
857 
858 /*-------------------------------------------------------------------------*/
859 
860 static void goku_clear_halt(struct goku_ep *ep)
861 {
862 	// assert (ep->num !=0)
863 	VDBG(ep->dev, "%s clear halt\n", ep->ep.name);
864 	command(ep->dev->regs, COMMAND_SETDATA0, ep->num);
865 	command(ep->dev->regs, COMMAND_STALL_CLEAR, ep->num);
866 	if (ep->stopped) {
867 		ep->stopped = 0;
868 		if (ep->dma) {
869 			struct goku_request	*req;
870 
871 			if (list_empty(&ep->queue))
872 				return;
873 			req = list_entry(ep->queue.next, struct goku_request,
874 						queue);
875 			(void) start_dma(ep, req);
876 		} else
877 			pio_advance(ep);
878 	}
879 }
880 
881 static int goku_set_halt(struct usb_ep *_ep, int value)
882 {
883 	struct goku_ep	*ep;
884 	unsigned long	flags;
885 	int		retval = 0;
886 
887 	if (!_ep)
888 		return -ENODEV;
889 	ep = container_of (_ep, struct goku_ep, ep);
890 
891 	if (ep->num == 0) {
892 		if (value) {
893 			ep->dev->ep0state = EP0_STALL;
894 			ep->dev->ep[0].stopped = 1;
895 		} else
896 			return -EINVAL;
897 
898 	/* don't change EPxSTATUS_EP_INVALID to READY */
899 	} else if (!ep->ep.desc) {
900 		DBG(ep->dev, "%s %s inactive?\n", __func__, ep->ep.name);
901 		return -EINVAL;
902 	}
903 
904 	spin_lock_irqsave(&ep->dev->lock, flags);
905 	if (!list_empty(&ep->queue))
906 		retval = -EAGAIN;
907 	else if (ep->is_in && value
908 			/* data in (either) packet buffer? */
909 			&& (readl(&ep->dev->regs->DataSet)
910 					& DATASET_AB(ep->num)))
911 		retval = -EAGAIN;
912 	else if (!value)
913 		goku_clear_halt(ep);
914 	else {
915 		ep->stopped = 1;
916 		VDBG(ep->dev, "%s set halt\n", ep->ep.name);
917 		command(ep->dev->regs, COMMAND_STALL, ep->num);
918 		readl(ep->reg_status);
919 	}
920 	spin_unlock_irqrestore(&ep->dev->lock, flags);
921 	return retval;
922 }
923 
924 static int goku_fifo_status(struct usb_ep *_ep)
925 {
926 	struct goku_ep			*ep;
927 	struct goku_udc_regs __iomem	*regs;
928 	u32				size;
929 
930 	if (!_ep)
931 		return -ENODEV;
932 	ep = container_of(_ep, struct goku_ep, ep);
933 
934 	/* size is only reported sanely for OUT */
935 	if (ep->is_in)
936 		return -EOPNOTSUPP;
937 
938 	/* ignores 16-byte dma buffer; SizeH == 0 */
939 	regs = ep->dev->regs;
940 	size = readl(&regs->EPxSizeLA[ep->num]) & DATASIZE;
941 	size += readl(&regs->EPxSizeLB[ep->num]) & DATASIZE;
942 	VDBG(ep->dev, "%s %s %u\n", __func__, ep->ep.name, size);
943 	return size;
944 }
945 
946 static void goku_fifo_flush(struct usb_ep *_ep)
947 {
948 	struct goku_ep			*ep;
949 	struct goku_udc_regs __iomem	*regs;
950 	u32				size;
951 
952 	if (!_ep)
953 		return;
954 	ep = container_of(_ep, struct goku_ep, ep);
955 	VDBG(ep->dev, "%s %s\n", __func__, ep->ep.name);
956 
957 	/* don't change EPxSTATUS_EP_INVALID to READY */
958 	if (!ep->ep.desc && ep->num != 0) {
959 		DBG(ep->dev, "%s %s inactive?\n", __func__, ep->ep.name);
960 		return;
961 	}
962 
963 	regs = ep->dev->regs;
964 	size = readl(&regs->EPxSizeLA[ep->num]);
965 	size &= DATASIZE;
966 
967 	/* Non-desirable behavior:  FIFO_CLEAR also clears the
968 	 * endpoint halt feature.  For OUT, we _could_ just read
969 	 * the bytes out (PIO, if !ep->dma); for in, no choice.
970 	 */
971 	if (size)
972 		command(regs, COMMAND_FIFO_CLEAR, ep->num);
973 }
974 
975 static const struct usb_ep_ops goku_ep_ops = {
976 	.enable		= goku_ep_enable,
977 	.disable	= goku_ep_disable,
978 
979 	.alloc_request	= goku_alloc_request,
980 	.free_request	= goku_free_request,
981 
982 	.queue		= goku_queue,
983 	.dequeue	= goku_dequeue,
984 
985 	.set_halt	= goku_set_halt,
986 	.fifo_status	= goku_fifo_status,
987 	.fifo_flush	= goku_fifo_flush,
988 };
989 
990 /*-------------------------------------------------------------------------*/
991 
992 static int goku_get_frame(struct usb_gadget *_gadget)
993 {
994 	return -EOPNOTSUPP;
995 }
996 
997 static struct usb_ep *goku_match_ep(struct usb_gadget *g,
998 		struct usb_endpoint_descriptor *desc,
999 		struct usb_ss_ep_comp_descriptor *ep_comp)
1000 {
1001 	struct goku_udc	*dev = to_goku_udc(g);
1002 	struct usb_ep *ep;
1003 
1004 	switch (usb_endpoint_type(desc)) {
1005 	case USB_ENDPOINT_XFER_INT:
1006 		/* single buffering is enough */
1007 		ep = &dev->ep[3].ep;
1008 		if (usb_gadget_ep_match_desc(g, ep, desc, ep_comp))
1009 			return ep;
1010 		break;
1011 	case USB_ENDPOINT_XFER_BULK:
1012 		if (usb_endpoint_dir_in(desc)) {
1013 			/* DMA may be available */
1014 			ep = &dev->ep[2].ep;
1015 			if (usb_gadget_ep_match_desc(g, ep, desc, ep_comp))
1016 				return ep;
1017 		}
1018 		break;
1019 	default:
1020 		/* nothing */ ;
1021 	}
1022 
1023 	return NULL;
1024 }
1025 
1026 static int goku_udc_start(struct usb_gadget *g,
1027 		struct usb_gadget_driver *driver);
1028 static int goku_udc_stop(struct usb_gadget *g);
1029 
1030 static const struct usb_gadget_ops goku_ops = {
1031 	.get_frame	= goku_get_frame,
1032 	.udc_start	= goku_udc_start,
1033 	.udc_stop	= goku_udc_stop,
1034 	.match_ep	= goku_match_ep,
1035 	// no remote wakeup
1036 	// not selfpowered
1037 };
1038 
1039 /*-------------------------------------------------------------------------*/
1040 
1041 static inline const char *dmastr(void)
1042 {
1043 	if (use_dma == 0)
1044 		return "(dma disabled)";
1045 	else if (use_dma == 2)
1046 		return "(dma IN and OUT)";
1047 	else
1048 		return "(dma IN)";
1049 }
1050 
1051 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
1052 
1053 static const char proc_node_name [] = "driver/udc";
1054 
1055 #define FOURBITS "%s%s%s%s"
1056 #define EIGHTBITS FOURBITS FOURBITS
1057 
1058 static void dump_intmask(struct seq_file *m, const char *label, u32 mask)
1059 {
1060 	/* int_status is the same format ... */
1061 	seq_printf(m, "%s %05X =" FOURBITS EIGHTBITS EIGHTBITS "\n",
1062 		   label, mask,
1063 		   (mask & INT_PWRDETECT) ? " power" : "",
1064 		   (mask & INT_SYSERROR) ? " sys" : "",
1065 		   (mask & INT_MSTRDEND) ? " in-dma" : "",
1066 		   (mask & INT_MSTWRTMOUT) ? " wrtmo" : "",
1067 
1068 		   (mask & INT_MSTWREND) ? " out-dma" : "",
1069 		   (mask & INT_MSTWRSET) ? " wrset" : "",
1070 		   (mask & INT_ERR) ? " err" : "",
1071 		   (mask & INT_SOF) ? " sof" : "",
1072 
1073 		   (mask & INT_EP3NAK) ? " ep3nak" : "",
1074 		   (mask & INT_EP2NAK) ? " ep2nak" : "",
1075 		   (mask & INT_EP1NAK) ? " ep1nak" : "",
1076 		   (mask & INT_EP3DATASET) ? " ep3" : "",
1077 
1078 		   (mask & INT_EP2DATASET) ? " ep2" : "",
1079 		   (mask & INT_EP1DATASET) ? " ep1" : "",
1080 		   (mask & INT_STATUSNAK) ? " ep0snak" : "",
1081 		   (mask & INT_STATUS) ? " ep0status" : "",
1082 
1083 		   (mask & INT_SETUP) ? " setup" : "",
1084 		   (mask & INT_ENDPOINT0) ? " ep0" : "",
1085 		   (mask & INT_USBRESET) ? " reset" : "",
1086 		   (mask & INT_SUSPEND) ? " suspend" : "");
1087 }
1088 
1089 static const char *udc_ep_state(enum ep0state state)
1090 {
1091 	switch (state) {
1092 	case EP0_DISCONNECT:
1093 		return "ep0_disconnect";
1094 	case EP0_IDLE:
1095 		return "ep0_idle";
1096 	case EP0_IN:
1097 		return "ep0_in";
1098 	case EP0_OUT:
1099 		return "ep0_out";
1100 	case EP0_STATUS:
1101 		return "ep0_status";
1102 	case EP0_STALL:
1103 		return "ep0_stall";
1104 	case EP0_SUSPEND:
1105 		return "ep0_suspend";
1106 	}
1107 
1108 	return "ep0_?";
1109 }
1110 
1111 static const char *udc_ep_status(u32 status)
1112 {
1113 	switch (status & EPxSTATUS_EP_MASK) {
1114 	case EPxSTATUS_EP_READY:
1115 		return "ready";
1116 	case EPxSTATUS_EP_DATAIN:
1117 		return "packet";
1118 	case EPxSTATUS_EP_FULL:
1119 		return "full";
1120 	case EPxSTATUS_EP_TX_ERR:	/* host will retry */
1121 		return "tx_err";
1122 	case EPxSTATUS_EP_RX_ERR:
1123 		return "rx_err";
1124 	case EPxSTATUS_EP_BUSY:		/* ep0 only */
1125 		return "busy";
1126 	case EPxSTATUS_EP_STALL:
1127 		return "stall";
1128 	case EPxSTATUS_EP_INVALID:	/* these "can't happen" */
1129 		return "invalid";
1130 	}
1131 
1132 	return "?";
1133 }
1134 
1135 static int udc_proc_read(struct seq_file *m, void *v)
1136 {
1137 	struct goku_udc			*dev = m->private;
1138 	struct goku_udc_regs __iomem	*regs = dev->regs;
1139 	unsigned long			flags;
1140 	int				i, is_usb_connected;
1141 	u32				tmp;
1142 
1143 	local_irq_save(flags);
1144 
1145 	/* basic device status */
1146 	tmp = readl(&regs->power_detect);
1147 	is_usb_connected = tmp & PW_DETECT;
1148 	seq_printf(m,
1149 		   "%s - %s\n"
1150 		   "%s version: %s %s\n"
1151 		   "Gadget driver: %s\n"
1152 		   "Host %s, %s\n"
1153 		   "\n",
1154 		   pci_name(dev->pdev), driver_desc,
1155 		   driver_name, DRIVER_VERSION, dmastr(),
1156 		   dev->driver ? dev->driver->driver.name : "(none)",
1157 		   is_usb_connected
1158 			   ? ((tmp & PW_PULLUP) ? "full speed" : "powered")
1159 			   : "disconnected",
1160 		   udc_ep_state(dev->ep0state));
1161 
1162 	dump_intmask(m, "int_status", readl(&regs->int_status));
1163 	dump_intmask(m, "int_enable", readl(&regs->int_enable));
1164 
1165 	if (!is_usb_connected || !dev->driver || (tmp & PW_PULLUP) == 0)
1166 		goto done;
1167 
1168 	/* registers for (active) device and ep0 */
1169 	seq_printf(m, "\nirqs %lu\ndataset %02x single.bcs %02x.%02x state %x addr %u\n",
1170 		   dev->irqs, readl(&regs->DataSet),
1171 		   readl(&regs->EPxSingle), readl(&regs->EPxBCS),
1172 		   readl(&regs->UsbState),
1173 		   readl(&regs->address));
1174 	if (seq_has_overflowed(m))
1175 		goto done;
1176 
1177 	tmp = readl(&regs->dma_master);
1178 	seq_printf(m, "dma %03X =" EIGHTBITS "%s %s\n",
1179 		   tmp,
1180 		   (tmp & MST_EOPB_DIS) ? " eopb-" : "",
1181 		   (tmp & MST_EOPB_ENA) ? " eopb+" : "",
1182 		   (tmp & MST_TIMEOUT_DIS) ? " tmo-" : "",
1183 		   (tmp & MST_TIMEOUT_ENA) ? " tmo+" : "",
1184 
1185 		   (tmp & MST_RD_EOPB) ? " eopb" : "",
1186 		   (tmp & MST_RD_RESET) ? " in_reset" : "",
1187 		   (tmp & MST_WR_RESET) ? " out_reset" : "",
1188 		   (tmp & MST_RD_ENA) ? " IN" : "",
1189 
1190 		   (tmp & MST_WR_ENA) ? " OUT" : "",
1191 		   (tmp & MST_CONNECTION) ? "ep1in/ep2out" : "ep1out/ep2in");
1192 	if (seq_has_overflowed(m))
1193 		goto done;
1194 
1195 	/* dump endpoint queues */
1196 	for (i = 0; i < 4; i++) {
1197 		struct goku_ep		*ep = &dev->ep [i];
1198 		struct goku_request	*req;
1199 
1200 		if (i && !ep->ep.desc)
1201 			continue;
1202 
1203 		tmp = readl(ep->reg_status);
1204 		seq_printf(m, "%s %s max %u %s, irqs %lu, status %02x (%s) " FOURBITS "\n",
1205 			   ep->ep.name,
1206 			   ep->is_in ? "in" : "out",
1207 			   ep->ep.maxpacket,
1208 			   ep->dma ? "dma" : "pio",
1209 			   ep->irqs,
1210 			   tmp, udc_ep_status(tmp),
1211 			   (tmp & EPxSTATUS_TOGGLE) ? "data1" : "data0",
1212 			   (tmp & EPxSTATUS_SUSPEND) ? " suspend" : "",
1213 			   (tmp & EPxSTATUS_FIFO_DISABLE) ? " disable" : "",
1214 			   (tmp & EPxSTATUS_STAGE_ERROR) ? " ep0stat" : "");
1215 		if (seq_has_overflowed(m))
1216 			goto done;
1217 
1218 		if (list_empty(&ep->queue)) {
1219 			seq_puts(m, "\t(nothing queued)\n");
1220 			if (seq_has_overflowed(m))
1221 				goto done;
1222 			continue;
1223 		}
1224 		list_for_each_entry(req, &ep->queue, queue) {
1225 			if (ep->dma && req->queue.prev == &ep->queue) {
1226 				if (i == UDC_MSTRD_ENDPOINT)
1227 					tmp = readl(&regs->in_dma_current);
1228 				else
1229 					tmp = readl(&regs->out_dma_current);
1230 				tmp -= req->req.dma;
1231 				tmp++;
1232 			} else
1233 				tmp = req->req.actual;
1234 
1235 			seq_printf(m, "\treq %p len %u/%u buf %p\n",
1236 				   &req->req, tmp, req->req.length,
1237 				   req->req.buf);
1238 			if (seq_has_overflowed(m))
1239 				goto done;
1240 		}
1241 	}
1242 
1243 done:
1244 	local_irq_restore(flags);
1245 	return 0;
1246 }
1247 #endif	/* CONFIG_USB_GADGET_DEBUG_FILES */
1248 
1249 /*-------------------------------------------------------------------------*/
1250 
1251 static void udc_reinit (struct goku_udc *dev)
1252 {
1253 	static char *names [] = { "ep0", "ep1-bulk", "ep2-bulk", "ep3-bulk" };
1254 
1255 	unsigned i;
1256 
1257 	INIT_LIST_HEAD (&dev->gadget.ep_list);
1258 	dev->gadget.ep0 = &dev->ep [0].ep;
1259 	dev->gadget.speed = USB_SPEED_UNKNOWN;
1260 	dev->ep0state = EP0_DISCONNECT;
1261 	dev->irqs = 0;
1262 
1263 	for (i = 0; i < 4; i++) {
1264 		struct goku_ep	*ep = &dev->ep[i];
1265 
1266 		ep->num = i;
1267 		ep->ep.name = names[i];
1268 		ep->reg_fifo = &dev->regs->ep_fifo [i];
1269 		ep->reg_status = &dev->regs->ep_status [i];
1270 		ep->reg_mode = &dev->regs->ep_mode[i];
1271 
1272 		ep->ep.ops = &goku_ep_ops;
1273 		list_add_tail (&ep->ep.ep_list, &dev->gadget.ep_list);
1274 		ep->dev = dev;
1275 		INIT_LIST_HEAD (&ep->queue);
1276 
1277 		ep_reset(NULL, ep);
1278 
1279 		if (i == 0)
1280 			ep->ep.caps.type_control = true;
1281 		else
1282 			ep->ep.caps.type_bulk = true;
1283 
1284 		ep->ep.caps.dir_in = true;
1285 		ep->ep.caps.dir_out = true;
1286 	}
1287 
1288 	dev->ep[0].reg_mode = NULL;
1289 	usb_ep_set_maxpacket_limit(&dev->ep[0].ep, MAX_EP0_SIZE);
1290 	list_del_init (&dev->ep[0].ep.ep_list);
1291 }
1292 
1293 static void udc_reset(struct goku_udc *dev)
1294 {
1295 	struct goku_udc_regs __iomem	*regs = dev->regs;
1296 
1297 	writel(0, &regs->power_detect);
1298 	writel(0, &regs->int_enable);
1299 	readl(&regs->int_enable);
1300 	dev->int_enable = 0;
1301 
1302 	/* deassert reset, leave USB D+ at hi-Z (no pullup)
1303 	 * don't let INT_PWRDETECT sequence begin
1304 	 */
1305 	udelay(250);
1306 	writel(PW_RESETB, &regs->power_detect);
1307 	readl(&regs->int_enable);
1308 }
1309 
1310 static void ep0_start(struct goku_udc *dev)
1311 {
1312 	struct goku_udc_regs __iomem	*regs = dev->regs;
1313 	unsigned			i;
1314 
1315 	VDBG(dev, "%s\n", __func__);
1316 
1317 	udc_reset(dev);
1318 	udc_reinit (dev);
1319 	//writel(MST_EOPB_ENA | MST_TIMEOUT_ENA, &regs->dma_master);
1320 
1321 	/* hw handles set_address, set_feature, get_status; maybe more */
1322 	writel(   G_REQMODE_SET_INTF | G_REQMODE_GET_INTF
1323 		| G_REQMODE_SET_CONF | G_REQMODE_GET_CONF
1324 		| G_REQMODE_GET_DESC
1325 		| G_REQMODE_CLEAR_FEAT
1326 		, &regs->reqmode);
1327 
1328 	for (i = 0; i < 4; i++)
1329 		dev->ep[i].irqs = 0;
1330 
1331 	/* can't modify descriptors after writing UsbReady */
1332 	for (i = 0; i < DESC_LEN; i++)
1333 		writel(0, &regs->descriptors[i]);
1334 	writel(0, &regs->UsbReady);
1335 
1336 	/* expect ep0 requests when the host drops reset */
1337 	writel(PW_RESETB | PW_PULLUP, &regs->power_detect);
1338 	dev->int_enable = INT_DEVWIDE | INT_EP0;
1339 	writel(dev->int_enable, &dev->regs->int_enable);
1340 	readl(&regs->int_enable);
1341 	dev->gadget.speed = USB_SPEED_FULL;
1342 	dev->ep0state = EP0_IDLE;
1343 }
1344 
1345 static void udc_enable(struct goku_udc *dev)
1346 {
1347 	/* start enumeration now, or after power detect irq */
1348 	if (readl(&dev->regs->power_detect) & PW_DETECT)
1349 		ep0_start(dev);
1350 	else {
1351 		DBG(dev, "%s\n", __func__);
1352 		dev->int_enable = INT_PWRDETECT;
1353 		writel(dev->int_enable, &dev->regs->int_enable);
1354 	}
1355 }
1356 
1357 /*-------------------------------------------------------------------------*/
1358 
1359 /* keeping it simple:
1360  * - one bus driver, initted first;
1361  * - one function driver, initted second
1362  */
1363 
1364 /* when a driver is successfully registered, it will receive
1365  * control requests including set_configuration(), which enables
1366  * non-control requests.  then usb traffic follows until a
1367  * disconnect is reported.  then a host may connect again, or
1368  * the driver might get unbound.
1369  */
1370 static int goku_udc_start(struct usb_gadget *g,
1371 		struct usb_gadget_driver *driver)
1372 {
1373 	struct goku_udc	*dev = to_goku_udc(g);
1374 
1375 	/* hook up the driver */
1376 	driver->driver.bus = NULL;
1377 	dev->driver = driver;
1378 
1379 	/*
1380 	 * then enable host detection and ep0; and we're ready
1381 	 * for set_configuration as well as eventual disconnect.
1382 	 */
1383 	udc_enable(dev);
1384 
1385 	return 0;
1386 }
1387 
1388 static void stop_activity(struct goku_udc *dev)
1389 {
1390 	unsigned	i;
1391 
1392 	DBG (dev, "%s\n", __func__);
1393 
1394 	/* disconnect gadget driver after quiesceing hw and the driver */
1395 	udc_reset (dev);
1396 	for (i = 0; i < 4; i++)
1397 		nuke(&dev->ep [i], -ESHUTDOWN);
1398 
1399 	if (dev->driver)
1400 		udc_enable(dev);
1401 }
1402 
1403 static int goku_udc_stop(struct usb_gadget *g)
1404 {
1405 	struct goku_udc	*dev = to_goku_udc(g);
1406 	unsigned long	flags;
1407 
1408 	spin_lock_irqsave(&dev->lock, flags);
1409 	dev->driver = NULL;
1410 	stop_activity(dev);
1411 	spin_unlock_irqrestore(&dev->lock, flags);
1412 
1413 	return 0;
1414 }
1415 
1416 /*-------------------------------------------------------------------------*/
1417 
1418 static void ep0_setup(struct goku_udc *dev)
1419 {
1420 	struct goku_udc_regs __iomem	*regs = dev->regs;
1421 	struct usb_ctrlrequest		ctrl;
1422 	int				tmp;
1423 
1424 	/* read SETUP packet and enter DATA stage */
1425 	ctrl.bRequestType = readl(&regs->bRequestType);
1426 	ctrl.bRequest = readl(&regs->bRequest);
1427 	ctrl.wValue  = cpu_to_le16((readl(&regs->wValueH)  << 8)
1428 					| readl(&regs->wValueL));
1429 	ctrl.wIndex  = cpu_to_le16((readl(&regs->wIndexH)  << 8)
1430 					| readl(&regs->wIndexL));
1431 	ctrl.wLength = cpu_to_le16((readl(&regs->wLengthH) << 8)
1432 					| readl(&regs->wLengthL));
1433 	writel(0, &regs->SetupRecv);
1434 
1435 	nuke(&dev->ep[0], 0);
1436 	dev->ep[0].stopped = 0;
1437 	if (likely(ctrl.bRequestType & USB_DIR_IN)) {
1438 		dev->ep[0].is_in = 1;
1439 		dev->ep0state = EP0_IN;
1440 		/* detect early status stages */
1441 		writel(ICONTROL_STATUSNAK, &dev->regs->IntControl);
1442 	} else {
1443 		dev->ep[0].is_in = 0;
1444 		dev->ep0state = EP0_OUT;
1445 
1446 		/* NOTE:  CLEAR_FEATURE is done in software so that we can
1447 		 * synchronize transfer restarts after bulk IN stalls.  data
1448 		 * won't even enter the fifo until the halt is cleared.
1449 		 */
1450 		switch (ctrl.bRequest) {
1451 		case USB_REQ_CLEAR_FEATURE:
1452 			switch (ctrl.bRequestType) {
1453 			case USB_RECIP_ENDPOINT:
1454 				tmp = le16_to_cpu(ctrl.wIndex) & 0x0f;
1455 				/* active endpoint */
1456 				if (tmp > 3 ||
1457 				    (!dev->ep[tmp].ep.desc && tmp != 0))
1458 					goto stall;
1459 				if (ctrl.wIndex & cpu_to_le16(
1460 						USB_DIR_IN)) {
1461 					if (!dev->ep[tmp].is_in)
1462 						goto stall;
1463 				} else {
1464 					if (dev->ep[tmp].is_in)
1465 						goto stall;
1466 				}
1467 				if (ctrl.wValue != cpu_to_le16(
1468 						USB_ENDPOINT_HALT))
1469 					goto stall;
1470 				if (tmp)
1471 					goku_clear_halt(&dev->ep[tmp]);
1472 succeed:
1473 				/* start ep0out status stage */
1474 				writel(~(1<<0), &regs->EOP);
1475 				dev->ep[0].stopped = 1;
1476 				dev->ep0state = EP0_STATUS;
1477 				return;
1478 			case USB_RECIP_DEVICE:
1479 				/* device remote wakeup: always clear */
1480 				if (ctrl.wValue != cpu_to_le16(1))
1481 					goto stall;
1482 				VDBG(dev, "clear dev remote wakeup\n");
1483 				goto succeed;
1484 			case USB_RECIP_INTERFACE:
1485 				goto stall;
1486 			default:		/* pass to gadget driver */
1487 				break;
1488 			}
1489 			break;
1490 		default:
1491 			break;
1492 		}
1493 	}
1494 
1495 #ifdef USB_TRACE
1496 	VDBG(dev, "SETUP %02x.%02x v%04x i%04x l%04x\n",
1497 		ctrl.bRequestType, ctrl.bRequest,
1498 		le16_to_cpu(ctrl.wValue), le16_to_cpu(ctrl.wIndex),
1499 		le16_to_cpu(ctrl.wLength));
1500 #endif
1501 
1502 	/* hw wants to know when we're configured (or not) */
1503 	dev->req_config = (ctrl.bRequest == USB_REQ_SET_CONFIGURATION
1504 				&& ctrl.bRequestType == USB_RECIP_DEVICE);
1505 	if (unlikely(dev->req_config))
1506 		dev->configured = (ctrl.wValue != cpu_to_le16(0));
1507 
1508 	/* delegate everything to the gadget driver.
1509 	 * it may respond after this irq handler returns.
1510 	 */
1511 	spin_unlock (&dev->lock);
1512 	tmp = dev->driver->setup(&dev->gadget, &ctrl);
1513 	spin_lock (&dev->lock);
1514 	if (unlikely(tmp < 0)) {
1515 stall:
1516 #ifdef USB_TRACE
1517 		VDBG(dev, "req %02x.%02x protocol STALL; err %d\n",
1518 				ctrl.bRequestType, ctrl.bRequest, tmp);
1519 #endif
1520 		command(regs, COMMAND_STALL, 0);
1521 		dev->ep[0].stopped = 1;
1522 		dev->ep0state = EP0_STALL;
1523 	}
1524 
1525 	/* expect at least one data or status stage irq */
1526 }
1527 
1528 #define ACK(irqbit) { \
1529 		stat &= ~irqbit; \
1530 		writel(~irqbit, &regs->int_status); \
1531 		handled = 1; \
1532 		}
1533 
1534 static irqreturn_t goku_irq(int irq, void *_dev)
1535 {
1536 	struct goku_udc			*dev = _dev;
1537 	struct goku_udc_regs __iomem	*regs = dev->regs;
1538 	struct goku_ep			*ep;
1539 	u32				stat, handled = 0;
1540 	unsigned			i, rescans = 5;
1541 
1542 	spin_lock(&dev->lock);
1543 
1544 rescan:
1545 	stat = readl(&regs->int_status) & dev->int_enable;
1546         if (!stat)
1547 		goto done;
1548 	dev->irqs++;
1549 
1550 	/* device-wide irqs */
1551 	if (unlikely(stat & INT_DEVWIDE)) {
1552 		if (stat & INT_SYSERROR) {
1553 			ERROR(dev, "system error\n");
1554 			stop_activity(dev);
1555 			stat = 0;
1556 			handled = 1;
1557 			// FIXME have a neater way to prevent re-enumeration
1558 			dev->driver = NULL;
1559 			goto done;
1560 		}
1561 		if (stat & INT_PWRDETECT) {
1562 			writel(~stat, &regs->int_status);
1563 			if (readl(&dev->regs->power_detect) & PW_DETECT) {
1564 				VDBG(dev, "connect\n");
1565 				ep0_start(dev);
1566 			} else {
1567 				DBG(dev, "disconnect\n");
1568 				if (dev->gadget.speed == USB_SPEED_FULL)
1569 					stop_activity(dev);
1570 				dev->ep0state = EP0_DISCONNECT;
1571 				dev->int_enable = INT_DEVWIDE;
1572 				writel(dev->int_enable, &dev->regs->int_enable);
1573 			}
1574 			stat = 0;
1575 			handled = 1;
1576 			goto done;
1577 		}
1578 		if (stat & INT_SUSPEND) {
1579 			ACK(INT_SUSPEND);
1580 			if (readl(&regs->ep_status[0]) & EPxSTATUS_SUSPEND) {
1581 				switch (dev->ep0state) {
1582 				case EP0_DISCONNECT:
1583 				case EP0_SUSPEND:
1584 					goto pm_next;
1585 				default:
1586 					break;
1587 				}
1588 				DBG(dev, "USB suspend\n");
1589 				dev->ep0state = EP0_SUSPEND;
1590 				if (dev->gadget.speed != USB_SPEED_UNKNOWN
1591 						&& dev->driver
1592 						&& dev->driver->suspend) {
1593 					spin_unlock(&dev->lock);
1594 					dev->driver->suspend(&dev->gadget);
1595 					spin_lock(&dev->lock);
1596 				}
1597 			} else {
1598 				if (dev->ep0state != EP0_SUSPEND) {
1599 					DBG(dev, "bogus USB resume %d\n",
1600 						dev->ep0state);
1601 					goto pm_next;
1602 				}
1603 				DBG(dev, "USB resume\n");
1604 				dev->ep0state = EP0_IDLE;
1605 				if (dev->gadget.speed != USB_SPEED_UNKNOWN
1606 						&& dev->driver
1607 						&& dev->driver->resume) {
1608 					spin_unlock(&dev->lock);
1609 					dev->driver->resume(&dev->gadget);
1610 					spin_lock(&dev->lock);
1611 				}
1612 			}
1613 		}
1614 pm_next:
1615 		if (stat & INT_USBRESET) {		/* hub reset done */
1616 			ACK(INT_USBRESET);
1617 			INFO(dev, "USB reset done, gadget %s\n",
1618 				dev->driver->driver.name);
1619 		}
1620 		// and INT_ERR on some endpoint's crc/bitstuff/... problem
1621 	}
1622 
1623 	/* progress ep0 setup, data, or status stages.
1624 	 * no transition {EP0_STATUS, EP0_STALL} --> EP0_IDLE; saves irqs
1625 	 */
1626 	if (stat & INT_SETUP) {
1627 		ACK(INT_SETUP);
1628 		dev->ep[0].irqs++;
1629 		ep0_setup(dev);
1630 	}
1631         if (stat & INT_STATUSNAK) {
1632 		ACK(INT_STATUSNAK|INT_ENDPOINT0);
1633 		if (dev->ep0state == EP0_IN) {
1634 			ep = &dev->ep[0];
1635 			ep->irqs++;
1636 			nuke(ep, 0);
1637 			writel(~(1<<0), &regs->EOP);
1638 			dev->ep0state = EP0_STATUS;
1639 		}
1640 	}
1641         if (stat & INT_ENDPOINT0) {
1642 		ACK(INT_ENDPOINT0);
1643 		ep = &dev->ep[0];
1644 		ep->irqs++;
1645 		pio_advance(ep);
1646         }
1647 
1648 	/* dma completion */
1649         if (stat & INT_MSTRDEND) {	/* IN */
1650 		ACK(INT_MSTRDEND);
1651 		ep = &dev->ep[UDC_MSTRD_ENDPOINT];
1652 		ep->irqs++;
1653 		dma_advance(dev, ep);
1654         }
1655         if (stat & INT_MSTWREND) {	/* OUT */
1656 		ACK(INT_MSTWREND);
1657 		ep = &dev->ep[UDC_MSTWR_ENDPOINT];
1658 		ep->irqs++;
1659 		dma_advance(dev, ep);
1660         }
1661         if (stat & INT_MSTWRTMOUT) {	/* OUT */
1662 		ACK(INT_MSTWRTMOUT);
1663 		ep = &dev->ep[UDC_MSTWR_ENDPOINT];
1664 		ep->irqs++;
1665 		ERROR(dev, "%s write timeout ?\n", ep->ep.name);
1666 		// reset dma? then dma_advance()
1667         }
1668 
1669 	/* pio */
1670 	for (i = 1; i < 4; i++) {
1671 		u32		tmp = INT_EPxDATASET(i);
1672 
1673 		if (!(stat & tmp))
1674 			continue;
1675 		ep = &dev->ep[i];
1676 		pio_advance(ep);
1677 		if (list_empty (&ep->queue))
1678 			pio_irq_disable(dev, regs, i);
1679 		stat &= ~tmp;
1680 		handled = 1;
1681 		ep->irqs++;
1682 	}
1683 
1684 	if (rescans--)
1685 		goto rescan;
1686 
1687 done:
1688 	(void)readl(&regs->int_enable);
1689 	spin_unlock(&dev->lock);
1690 	if (stat)
1691 		DBG(dev, "unhandled irq status: %05x (%05x, %05x)\n", stat,
1692 				readl(&regs->int_status), dev->int_enable);
1693 	return IRQ_RETVAL(handled);
1694 }
1695 
1696 #undef ACK
1697 
1698 /*-------------------------------------------------------------------------*/
1699 
1700 static void gadget_release(struct device *_dev)
1701 {
1702 	struct goku_udc	*dev = dev_get_drvdata(_dev);
1703 
1704 	kfree(dev);
1705 }
1706 
1707 /* tear down the binding between this driver and the pci device */
1708 
1709 static void goku_remove(struct pci_dev *pdev)
1710 {
1711 	struct goku_udc		*dev = pci_get_drvdata(pdev);
1712 
1713 	DBG(dev, "%s\n", __func__);
1714 
1715 	usb_del_gadget_udc(&dev->gadget);
1716 
1717 	BUG_ON(dev->driver);
1718 
1719 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
1720 	remove_proc_entry(proc_node_name, NULL);
1721 #endif
1722 	if (dev->regs)
1723 		udc_reset(dev);
1724 	if (dev->got_irq)
1725 		free_irq(pdev->irq, dev);
1726 	if (dev->regs)
1727 		iounmap(dev->regs);
1728 	if (dev->got_region)
1729 		release_mem_region(pci_resource_start (pdev, 0),
1730 				pci_resource_len (pdev, 0));
1731 	if (dev->enabled)
1732 		pci_disable_device(pdev);
1733 
1734 	dev->regs = NULL;
1735 
1736 	INFO(dev, "unbind\n");
1737 }
1738 
1739 /* wrap this driver around the specified pci device, but
1740  * don't respond over USB until a gadget driver binds to us.
1741  */
1742 
1743 static int goku_probe(struct pci_dev *pdev, const struct pci_device_id *id)
1744 {
1745 	struct goku_udc		*dev = NULL;
1746 	unsigned long		resource, len;
1747 	void __iomem		*base = NULL;
1748 	int			retval;
1749 
1750 	if (!pdev->irq) {
1751 		printk(KERN_ERR "Check PCI %s IRQ setup!\n", pci_name(pdev));
1752 		retval = -ENODEV;
1753 		goto err;
1754 	}
1755 
1756 	/* alloc, and start init */
1757 	dev = kzalloc (sizeof *dev, GFP_KERNEL);
1758 	if (!dev) {
1759 		retval = -ENOMEM;
1760 		goto err;
1761 	}
1762 
1763 	pci_set_drvdata(pdev, dev);
1764 	spin_lock_init(&dev->lock);
1765 	dev->pdev = pdev;
1766 	dev->gadget.ops = &goku_ops;
1767 	dev->gadget.max_speed = USB_SPEED_FULL;
1768 
1769 	/* the "gadget" abstracts/virtualizes the controller */
1770 	dev->gadget.name = driver_name;
1771 
1772 	/* now all the pci goodies ... */
1773 	retval = pci_enable_device(pdev);
1774 	if (retval < 0) {
1775 		DBG(dev, "can't enable, %d\n", retval);
1776 		goto err;
1777 	}
1778 	dev->enabled = 1;
1779 
1780 	resource = pci_resource_start(pdev, 0);
1781 	len = pci_resource_len(pdev, 0);
1782 	if (!request_mem_region(resource, len, driver_name)) {
1783 		DBG(dev, "controller already in use\n");
1784 		retval = -EBUSY;
1785 		goto err;
1786 	}
1787 	dev->got_region = 1;
1788 
1789 	base = ioremap(resource, len);
1790 	if (base == NULL) {
1791 		DBG(dev, "can't map memory\n");
1792 		retval = -EFAULT;
1793 		goto err;
1794 	}
1795 	dev->regs = (struct goku_udc_regs __iomem *) base;
1796 
1797 	INFO(dev, "%s\n", driver_desc);
1798 	INFO(dev, "version: " DRIVER_VERSION " %s\n", dmastr());
1799 	INFO(dev, "irq %d, pci mem %p\n", pdev->irq, base);
1800 
1801 	/* init to known state, then setup irqs */
1802 	udc_reset(dev);
1803 	udc_reinit (dev);
1804 	if (request_irq(pdev->irq, goku_irq, IRQF_SHARED,
1805 			driver_name, dev) != 0) {
1806 		DBG(dev, "request interrupt %d failed\n", pdev->irq);
1807 		retval = -EBUSY;
1808 		goto err;
1809 	}
1810 	dev->got_irq = 1;
1811 	if (use_dma)
1812 		pci_set_master(pdev);
1813 
1814 
1815 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
1816 	proc_create_single_data(proc_node_name, 0, NULL, udc_proc_read, dev);
1817 #endif
1818 
1819 	retval = usb_add_gadget_udc_release(&pdev->dev, &dev->gadget,
1820 			gadget_release);
1821 	if (retval)
1822 		goto err;
1823 
1824 	return 0;
1825 
1826 err:
1827 	if (dev)
1828 		goku_remove (pdev);
1829 	/* gadget_release is not registered yet, kfree explicitly */
1830 	kfree(dev);
1831 	return retval;
1832 }
1833 
1834 
1835 /*-------------------------------------------------------------------------*/
1836 
1837 static const struct pci_device_id pci_ids[] = { {
1838 	.class =	PCI_CLASS_SERIAL_USB_DEVICE,
1839 	.class_mask =	~0,
1840 	.vendor =	0x102f,		/* Toshiba */
1841 	.device =	0x0107,		/* this UDC */
1842 	.subvendor =	PCI_ANY_ID,
1843 	.subdevice =	PCI_ANY_ID,
1844 
1845 }, { /* end: all zeroes */ }
1846 };
1847 MODULE_DEVICE_TABLE (pci, pci_ids);
1848 
1849 static struct pci_driver goku_pci_driver = {
1850 	.name =		driver_name,
1851 	.id_table =	pci_ids,
1852 
1853 	.probe =	goku_probe,
1854 	.remove =	goku_remove,
1855 
1856 	/* FIXME add power management support */
1857 };
1858 
1859 module_pci_driver(goku_pci_driver);
1860