xref: /openbmc/linux/drivers/usb/gadget/udc/at91_udc.c (revision e2c75e76)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * at91_udc -- driver for at91-series USB peripheral controller
4  *
5  * Copyright (C) 2004 by Thomas Rathbone
6  * Copyright (C) 2005 by HP Labs
7  * Copyright (C) 2005 by David Brownell
8  */
9 
10 #undef	VERBOSE_DEBUG
11 #undef	PACKET_TRACE
12 
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/delay.h>
17 #include <linux/ioport.h>
18 #include <linux/slab.h>
19 #include <linux/errno.h>
20 #include <linux/list.h>
21 #include <linux/interrupt.h>
22 #include <linux/proc_fs.h>
23 #include <linux/prefetch.h>
24 #include <linux/clk.h>
25 #include <linux/usb/ch9.h>
26 #include <linux/usb/gadget.h>
27 #include <linux/of.h>
28 #include <linux/of_gpio.h>
29 #include <linux/platform_data/atmel.h>
30 #include <linux/regmap.h>
31 #include <linux/mfd/syscon.h>
32 #include <linux/mfd/syscon/atmel-matrix.h>
33 
34 #include "at91_udc.h"
35 
36 
37 /*
38  * This controller is simple and PIO-only.  It's used in many AT91-series
39  * full speed USB controllers, including the at91rm9200 (arm920T, with MMU),
40  * at91sam926x (arm926ejs, with MMU), and several no-mmu versions.
41  *
42  * This driver expects the board has been wired with two GPIOs supporting
43  * a VBUS sensing IRQ, and a D+ pullup.  (They may be omitted, but the
44  * testing hasn't covered such cases.)
45  *
46  * The pullup is most important (so it's integrated on sam926x parts).  It
47  * provides software control over whether the host enumerates the device.
48  *
49  * The VBUS sensing helps during enumeration, and allows both USB clocks
50  * (and the transceiver) to stay gated off until they're necessary, saving
51  * power.  During USB suspend, the 48 MHz clock is gated off in hardware;
52  * it may also be gated off by software during some Linux sleep states.
53  */
54 
55 #define	DRIVER_VERSION	"3 May 2006"
56 
57 static const char driver_name [] = "at91_udc";
58 
59 static const struct {
60 	const char *name;
61 	const struct usb_ep_caps caps;
62 } ep_info[] = {
63 #define EP_INFO(_name, _caps) \
64 	{ \
65 		.name = _name, \
66 		.caps = _caps, \
67 	}
68 
69 	EP_INFO("ep0",
70 		USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)),
71 	EP_INFO("ep1",
72 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
73 	EP_INFO("ep2",
74 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
75 	EP_INFO("ep3-int",
76 		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_ALL)),
77 	EP_INFO("ep4",
78 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
79 	EP_INFO("ep5",
80 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
81 
82 #undef EP_INFO
83 };
84 
85 #define ep0name		ep_info[0].name
86 
87 #define VBUS_POLL_TIMEOUT	msecs_to_jiffies(1000)
88 
89 #define at91_udp_read(udc, reg) \
90 	__raw_readl((udc)->udp_baseaddr + (reg))
91 #define at91_udp_write(udc, reg, val) \
92 	__raw_writel((val), (udc)->udp_baseaddr + (reg))
93 
94 /*-------------------------------------------------------------------------*/
95 
96 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
97 
98 #include <linux/seq_file.h>
99 
100 static const char debug_filename[] = "driver/udc";
101 
102 #define FOURBITS "%s%s%s%s"
103 #define EIGHTBITS FOURBITS FOURBITS
104 
105 static void proc_ep_show(struct seq_file *s, struct at91_ep *ep)
106 {
107 	static char		*types[] = {
108 		"control", "out-iso", "out-bulk", "out-int",
109 		"BOGUS",   "in-iso",  "in-bulk",  "in-int"};
110 
111 	u32			csr;
112 	struct at91_request	*req;
113 	unsigned long	flags;
114 	struct at91_udc	*udc = ep->udc;
115 
116 	spin_lock_irqsave(&udc->lock, flags);
117 
118 	csr = __raw_readl(ep->creg);
119 
120 	/* NOTE:  not collecting per-endpoint irq statistics... */
121 
122 	seq_printf(s, "\n");
123 	seq_printf(s, "%s, maxpacket %d %s%s %s%s\n",
124 			ep->ep.name, ep->ep.maxpacket,
125 			ep->is_in ? "in" : "out",
126 			ep->is_iso ? " iso" : "",
127 			ep->is_pingpong
128 				? (ep->fifo_bank ? "pong" : "ping")
129 				: "",
130 			ep->stopped ? " stopped" : "");
131 	seq_printf(s, "csr %08x rxbytes=%d %s %s %s" EIGHTBITS "\n",
132 		csr,
133 		(csr & 0x07ff0000) >> 16,
134 		(csr & (1 << 15)) ? "enabled" : "disabled",
135 		(csr & (1 << 11)) ? "DATA1" : "DATA0",
136 		types[(csr & 0x700) >> 8],
137 
138 		/* iff type is control then print current direction */
139 		(!(csr & 0x700))
140 			? ((csr & (1 << 7)) ? " IN" : " OUT")
141 			: "",
142 		(csr & (1 << 6)) ? " rxdatabk1" : "",
143 		(csr & (1 << 5)) ? " forcestall" : "",
144 		(csr & (1 << 4)) ? " txpktrdy" : "",
145 
146 		(csr & (1 << 3)) ? " stallsent" : "",
147 		(csr & (1 << 2)) ? " rxsetup" : "",
148 		(csr & (1 << 1)) ? " rxdatabk0" : "",
149 		(csr & (1 << 0)) ? " txcomp" : "");
150 	if (list_empty (&ep->queue))
151 		seq_printf(s, "\t(queue empty)\n");
152 
153 	else list_for_each_entry (req, &ep->queue, queue) {
154 		unsigned	length = req->req.actual;
155 
156 		seq_printf(s, "\treq %p len %d/%d buf %p\n",
157 				&req->req, length,
158 				req->req.length, req->req.buf);
159 	}
160 	spin_unlock_irqrestore(&udc->lock, flags);
161 }
162 
163 static void proc_irq_show(struct seq_file *s, const char *label, u32 mask)
164 {
165 	int i;
166 
167 	seq_printf(s, "%s %04x:%s%s" FOURBITS, label, mask,
168 		(mask & (1 << 13)) ? " wakeup" : "",
169 		(mask & (1 << 12)) ? " endbusres" : "",
170 
171 		(mask & (1 << 11)) ? " sofint" : "",
172 		(mask & (1 << 10)) ? " extrsm" : "",
173 		(mask & (1 << 9)) ? " rxrsm" : "",
174 		(mask & (1 << 8)) ? " rxsusp" : "");
175 	for (i = 0; i < 8; i++) {
176 		if (mask & (1 << i))
177 			seq_printf(s, " ep%d", i);
178 	}
179 	seq_printf(s, "\n");
180 }
181 
182 static int proc_udc_show(struct seq_file *s, void *unused)
183 {
184 	struct at91_udc	*udc = s->private;
185 	struct at91_ep	*ep;
186 	u32		tmp;
187 
188 	seq_printf(s, "%s: version %s\n", driver_name, DRIVER_VERSION);
189 
190 	seq_printf(s, "vbus %s, pullup %s, %s powered%s, gadget %s\n\n",
191 		udc->vbus ? "present" : "off",
192 		udc->enabled
193 			? (udc->vbus ? "active" : "enabled")
194 			: "disabled",
195 		udc->gadget.is_selfpowered ? "self" : "VBUS",
196 		udc->suspended ? ", suspended" : "",
197 		udc->driver ? udc->driver->driver.name : "(none)");
198 
199 	/* don't access registers when interface isn't clocked */
200 	if (!udc->clocked) {
201 		seq_printf(s, "(not clocked)\n");
202 		return 0;
203 	}
204 
205 	tmp = at91_udp_read(udc, AT91_UDP_FRM_NUM);
206 	seq_printf(s, "frame %05x:%s%s frame=%d\n", tmp,
207 		(tmp & AT91_UDP_FRM_OK) ? " ok" : "",
208 		(tmp & AT91_UDP_FRM_ERR) ? " err" : "",
209 		(tmp & AT91_UDP_NUM));
210 
211 	tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
212 	seq_printf(s, "glbstate %02x:%s" FOURBITS "\n", tmp,
213 		(tmp & AT91_UDP_RMWUPE) ? " rmwupe" : "",
214 		(tmp & AT91_UDP_RSMINPR) ? " rsminpr" : "",
215 		(tmp & AT91_UDP_ESR) ? " esr" : "",
216 		(tmp & AT91_UDP_CONFG) ? " confg" : "",
217 		(tmp & AT91_UDP_FADDEN) ? " fadden" : "");
218 
219 	tmp = at91_udp_read(udc, AT91_UDP_FADDR);
220 	seq_printf(s, "faddr   %03x:%s fadd=%d\n", tmp,
221 		(tmp & AT91_UDP_FEN) ? " fen" : "",
222 		(tmp & AT91_UDP_FADD));
223 
224 	proc_irq_show(s, "imr   ", at91_udp_read(udc, AT91_UDP_IMR));
225 	proc_irq_show(s, "isr   ", at91_udp_read(udc, AT91_UDP_ISR));
226 
227 	if (udc->enabled && udc->vbus) {
228 		proc_ep_show(s, &udc->ep[0]);
229 		list_for_each_entry (ep, &udc->gadget.ep_list, ep.ep_list) {
230 			if (ep->ep.desc)
231 				proc_ep_show(s, ep);
232 		}
233 	}
234 	return 0;
235 }
236 
237 static int proc_udc_open(struct inode *inode, struct file *file)
238 {
239 	return single_open(file, proc_udc_show, PDE_DATA(inode));
240 }
241 
242 static const struct file_operations proc_ops = {
243 	.owner		= THIS_MODULE,
244 	.open		= proc_udc_open,
245 	.read		= seq_read,
246 	.llseek		= seq_lseek,
247 	.release	= single_release,
248 };
249 
250 static void create_debug_file(struct at91_udc *udc)
251 {
252 	udc->pde = proc_create_data(debug_filename, 0, NULL, &proc_ops, udc);
253 }
254 
255 static void remove_debug_file(struct at91_udc *udc)
256 {
257 	if (udc->pde)
258 		remove_proc_entry(debug_filename, NULL);
259 }
260 
261 #else
262 
263 static inline void create_debug_file(struct at91_udc *udc) {}
264 static inline void remove_debug_file(struct at91_udc *udc) {}
265 
266 #endif
267 
268 
269 /*-------------------------------------------------------------------------*/
270 
271 static void done(struct at91_ep *ep, struct at91_request *req, int status)
272 {
273 	unsigned	stopped = ep->stopped;
274 	struct at91_udc	*udc = ep->udc;
275 
276 	list_del_init(&req->queue);
277 	if (req->req.status == -EINPROGRESS)
278 		req->req.status = status;
279 	else
280 		status = req->req.status;
281 	if (status && status != -ESHUTDOWN)
282 		VDBG("%s done %p, status %d\n", ep->ep.name, req, status);
283 
284 	ep->stopped = 1;
285 	spin_unlock(&udc->lock);
286 	usb_gadget_giveback_request(&ep->ep, &req->req);
287 	spin_lock(&udc->lock);
288 	ep->stopped = stopped;
289 
290 	/* ep0 is always ready; other endpoints need a non-empty queue */
291 	if (list_empty(&ep->queue) && ep->int_mask != (1 << 0))
292 		at91_udp_write(udc, AT91_UDP_IDR, ep->int_mask);
293 }
294 
295 /*-------------------------------------------------------------------------*/
296 
297 /* bits indicating OUT fifo has data ready */
298 #define	RX_DATA_READY	(AT91_UDP_RX_DATA_BK0 | AT91_UDP_RX_DATA_BK1)
299 
300 /*
301  * Endpoint FIFO CSR bits have a mix of bits, making it unsafe to just write
302  * back most of the value you just read (because of side effects, including
303  * bits that may change after reading and before writing).
304  *
305  * Except when changing a specific bit, always write values which:
306  *  - clear SET_FX bits (setting them could change something)
307  *  - set CLR_FX bits (clearing them could change something)
308  *
309  * There are also state bits like FORCESTALL, EPEDS, DIR, and EPTYPE
310  * that shouldn't normally be changed.
311  *
312  * NOTE at91sam9260 docs mention synch between UDPCK and MCK clock domains,
313  * implying a need to wait for one write to complete (test relevant bits)
314  * before starting the next write.  This shouldn't be an issue given how
315  * infrequently we write, except maybe for write-then-read idioms.
316  */
317 #define	SET_FX	(AT91_UDP_TXPKTRDY)
318 #define	CLR_FX	(RX_DATA_READY | AT91_UDP_RXSETUP \
319 		| AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)
320 
321 /* pull OUT packet data from the endpoint's fifo */
322 static int read_fifo (struct at91_ep *ep, struct at91_request *req)
323 {
324 	u32 __iomem	*creg = ep->creg;
325 	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
326 	u32		csr;
327 	u8		*buf;
328 	unsigned int	count, bufferspace, is_done;
329 
330 	buf = req->req.buf + req->req.actual;
331 	bufferspace = req->req.length - req->req.actual;
332 
333 	/*
334 	 * there might be nothing to read if ep_queue() calls us,
335 	 * or if we already emptied both pingpong buffers
336 	 */
337 rescan:
338 	csr = __raw_readl(creg);
339 	if ((csr & RX_DATA_READY) == 0)
340 		return 0;
341 
342 	count = (csr & AT91_UDP_RXBYTECNT) >> 16;
343 	if (count > ep->ep.maxpacket)
344 		count = ep->ep.maxpacket;
345 	if (count > bufferspace) {
346 		DBG("%s buffer overflow\n", ep->ep.name);
347 		req->req.status = -EOVERFLOW;
348 		count = bufferspace;
349 	}
350 	__raw_readsb(dreg, buf, count);
351 
352 	/* release and swap pingpong mem bank */
353 	csr |= CLR_FX;
354 	if (ep->is_pingpong) {
355 		if (ep->fifo_bank == 0) {
356 			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
357 			ep->fifo_bank = 1;
358 		} else {
359 			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK1);
360 			ep->fifo_bank = 0;
361 		}
362 	} else
363 		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
364 	__raw_writel(csr, creg);
365 
366 	req->req.actual += count;
367 	is_done = (count < ep->ep.maxpacket);
368 	if (count == bufferspace)
369 		is_done = 1;
370 
371 	PACKET("%s %p out/%d%s\n", ep->ep.name, &req->req, count,
372 			is_done ? " (done)" : "");
373 
374 	/*
375 	 * avoid extra trips through IRQ logic for packets already in
376 	 * the fifo ... maybe preventing an extra (expensive) OUT-NAK
377 	 */
378 	if (is_done)
379 		done(ep, req, 0);
380 	else if (ep->is_pingpong) {
381 		/*
382 		 * One dummy read to delay the code because of a HW glitch:
383 		 * CSR returns bad RXCOUNT when read too soon after updating
384 		 * RX_DATA_BK flags.
385 		 */
386 		csr = __raw_readl(creg);
387 
388 		bufferspace -= count;
389 		buf += count;
390 		goto rescan;
391 	}
392 
393 	return is_done;
394 }
395 
396 /* load fifo for an IN packet */
397 static int write_fifo(struct at91_ep *ep, struct at91_request *req)
398 {
399 	u32 __iomem	*creg = ep->creg;
400 	u32		csr = __raw_readl(creg);
401 	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
402 	unsigned	total, count, is_last;
403 	u8		*buf;
404 
405 	/*
406 	 * TODO: allow for writing two packets to the fifo ... that'll
407 	 * reduce the amount of IN-NAKing, but probably won't affect
408 	 * throughput much.  (Unlike preventing OUT-NAKing!)
409 	 */
410 
411 	/*
412 	 * If ep_queue() calls us, the queue is empty and possibly in
413 	 * odd states like TXCOMP not yet cleared (we do it, saving at
414 	 * least one IRQ) or the fifo not yet being free.  Those aren't
415 	 * issues normally (IRQ handler fast path).
416 	 */
417 	if (unlikely(csr & (AT91_UDP_TXCOMP | AT91_UDP_TXPKTRDY))) {
418 		if (csr & AT91_UDP_TXCOMP) {
419 			csr |= CLR_FX;
420 			csr &= ~(SET_FX | AT91_UDP_TXCOMP);
421 			__raw_writel(csr, creg);
422 			csr = __raw_readl(creg);
423 		}
424 		if (csr & AT91_UDP_TXPKTRDY)
425 			return 0;
426 	}
427 
428 	buf = req->req.buf + req->req.actual;
429 	prefetch(buf);
430 	total = req->req.length - req->req.actual;
431 	if (ep->ep.maxpacket < total) {
432 		count = ep->ep.maxpacket;
433 		is_last = 0;
434 	} else {
435 		count = total;
436 		is_last = (count < ep->ep.maxpacket) || !req->req.zero;
437 	}
438 
439 	/*
440 	 * Write the packet, maybe it's a ZLP.
441 	 *
442 	 * NOTE:  incrementing req->actual before we receive the ACK means
443 	 * gadget driver IN bytecounts can be wrong in fault cases.  That's
444 	 * fixable with PIO drivers like this one (save "count" here, and
445 	 * do the increment later on TX irq), but not for most DMA hardware.
446 	 *
447 	 * So all gadget drivers must accept that potential error.  Some
448 	 * hardware supports precise fifo status reporting, letting them
449 	 * recover when the actual bytecount matters (e.g. for USB Test
450 	 * and Measurement Class devices).
451 	 */
452 	__raw_writesb(dreg, buf, count);
453 	csr &= ~SET_FX;
454 	csr |= CLR_FX | AT91_UDP_TXPKTRDY;
455 	__raw_writel(csr, creg);
456 	req->req.actual += count;
457 
458 	PACKET("%s %p in/%d%s\n", ep->ep.name, &req->req, count,
459 			is_last ? " (done)" : "");
460 	if (is_last)
461 		done(ep, req, 0);
462 	return is_last;
463 }
464 
465 static void nuke(struct at91_ep *ep, int status)
466 {
467 	struct at91_request *req;
468 
469 	/* terminate any request in the queue */
470 	ep->stopped = 1;
471 	if (list_empty(&ep->queue))
472 		return;
473 
474 	VDBG("%s %s\n", __func__, ep->ep.name);
475 	while (!list_empty(&ep->queue)) {
476 		req = list_entry(ep->queue.next, struct at91_request, queue);
477 		done(ep, req, status);
478 	}
479 }
480 
481 /*-------------------------------------------------------------------------*/
482 
483 static int at91_ep_enable(struct usb_ep *_ep,
484 				const struct usb_endpoint_descriptor *desc)
485 {
486 	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
487 	struct at91_udc *udc;
488 	u16		maxpacket;
489 	u32		tmp;
490 	unsigned long	flags;
491 
492 	if (!_ep || !ep
493 			|| !desc || _ep->name == ep0name
494 			|| desc->bDescriptorType != USB_DT_ENDPOINT
495 			|| (maxpacket = usb_endpoint_maxp(desc)) == 0
496 			|| maxpacket > ep->maxpacket) {
497 		DBG("bad ep or descriptor\n");
498 		return -EINVAL;
499 	}
500 
501 	udc = ep->udc;
502 	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
503 		DBG("bogus device state\n");
504 		return -ESHUTDOWN;
505 	}
506 
507 	tmp = usb_endpoint_type(desc);
508 	switch (tmp) {
509 	case USB_ENDPOINT_XFER_CONTROL:
510 		DBG("only one control endpoint\n");
511 		return -EINVAL;
512 	case USB_ENDPOINT_XFER_INT:
513 		if (maxpacket > 64)
514 			goto bogus_max;
515 		break;
516 	case USB_ENDPOINT_XFER_BULK:
517 		switch (maxpacket) {
518 		case 8:
519 		case 16:
520 		case 32:
521 		case 64:
522 			goto ok;
523 		}
524 bogus_max:
525 		DBG("bogus maxpacket %d\n", maxpacket);
526 		return -EINVAL;
527 	case USB_ENDPOINT_XFER_ISOC:
528 		if (!ep->is_pingpong) {
529 			DBG("iso requires double buffering\n");
530 			return -EINVAL;
531 		}
532 		break;
533 	}
534 
535 ok:
536 	spin_lock_irqsave(&udc->lock, flags);
537 
538 	/* initialize endpoint to match this descriptor */
539 	ep->is_in = usb_endpoint_dir_in(desc);
540 	ep->is_iso = (tmp == USB_ENDPOINT_XFER_ISOC);
541 	ep->stopped = 0;
542 	if (ep->is_in)
543 		tmp |= 0x04;
544 	tmp <<= 8;
545 	tmp |= AT91_UDP_EPEDS;
546 	__raw_writel(tmp, ep->creg);
547 
548 	ep->ep.maxpacket = maxpacket;
549 
550 	/*
551 	 * reset/init endpoint fifo.  NOTE:  leaves fifo_bank alone,
552 	 * since endpoint resets don't reset hw pingpong state.
553 	 */
554 	at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
555 	at91_udp_write(udc, AT91_UDP_RST_EP, 0);
556 
557 	spin_unlock_irqrestore(&udc->lock, flags);
558 	return 0;
559 }
560 
561 static int at91_ep_disable (struct usb_ep * _ep)
562 {
563 	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
564 	struct at91_udc	*udc = ep->udc;
565 	unsigned long	flags;
566 
567 	if (ep == &ep->udc->ep[0])
568 		return -EINVAL;
569 
570 	spin_lock_irqsave(&udc->lock, flags);
571 
572 	nuke(ep, -ESHUTDOWN);
573 
574 	/* restore the endpoint's pristine config */
575 	ep->ep.desc = NULL;
576 	ep->ep.maxpacket = ep->maxpacket;
577 
578 	/* reset fifos and endpoint */
579 	if (ep->udc->clocked) {
580 		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
581 		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
582 		__raw_writel(0, ep->creg);
583 	}
584 
585 	spin_unlock_irqrestore(&udc->lock, flags);
586 	return 0;
587 }
588 
589 /*
590  * this is a PIO-only driver, so there's nothing
591  * interesting for request or buffer allocation.
592  */
593 
594 static struct usb_request *
595 at91_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
596 {
597 	struct at91_request *req;
598 
599 	req = kzalloc(sizeof (struct at91_request), gfp_flags);
600 	if (!req)
601 		return NULL;
602 
603 	INIT_LIST_HEAD(&req->queue);
604 	return &req->req;
605 }
606 
607 static void at91_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
608 {
609 	struct at91_request *req;
610 
611 	req = container_of(_req, struct at91_request, req);
612 	BUG_ON(!list_empty(&req->queue));
613 	kfree(req);
614 }
615 
616 static int at91_ep_queue(struct usb_ep *_ep,
617 			struct usb_request *_req, gfp_t gfp_flags)
618 {
619 	struct at91_request	*req;
620 	struct at91_ep		*ep;
621 	struct at91_udc		*udc;
622 	int			status;
623 	unsigned long		flags;
624 
625 	req = container_of(_req, struct at91_request, req);
626 	ep = container_of(_ep, struct at91_ep, ep);
627 
628 	if (!_req || !_req->complete
629 			|| !_req->buf || !list_empty(&req->queue)) {
630 		DBG("invalid request\n");
631 		return -EINVAL;
632 	}
633 
634 	if (!_ep || (!ep->ep.desc && ep->ep.name != ep0name)) {
635 		DBG("invalid ep\n");
636 		return -EINVAL;
637 	}
638 
639 	udc = ep->udc;
640 
641 	if (!udc || !udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
642 		DBG("invalid device\n");
643 		return -EINVAL;
644 	}
645 
646 	_req->status = -EINPROGRESS;
647 	_req->actual = 0;
648 
649 	spin_lock_irqsave(&udc->lock, flags);
650 
651 	/* try to kickstart any empty and idle queue */
652 	if (list_empty(&ep->queue) && !ep->stopped) {
653 		int	is_ep0;
654 
655 		/*
656 		 * If this control request has a non-empty DATA stage, this
657 		 * will start that stage.  It works just like a non-control
658 		 * request (until the status stage starts, maybe early).
659 		 *
660 		 * If the data stage is empty, then this starts a successful
661 		 * IN/STATUS stage.  (Unsuccessful ones use set_halt.)
662 		 */
663 		is_ep0 = (ep->ep.name == ep0name);
664 		if (is_ep0) {
665 			u32	tmp;
666 
667 			if (!udc->req_pending) {
668 				status = -EINVAL;
669 				goto done;
670 			}
671 
672 			/*
673 			 * defer changing CONFG until after the gadget driver
674 			 * reconfigures the endpoints.
675 			 */
676 			if (udc->wait_for_config_ack) {
677 				tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
678 				tmp ^= AT91_UDP_CONFG;
679 				VDBG("toggle config\n");
680 				at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
681 			}
682 			if (req->req.length == 0) {
683 ep0_in_status:
684 				PACKET("ep0 in/status\n");
685 				status = 0;
686 				tmp = __raw_readl(ep->creg);
687 				tmp &= ~SET_FX;
688 				tmp |= CLR_FX | AT91_UDP_TXPKTRDY;
689 				__raw_writel(tmp, ep->creg);
690 				udc->req_pending = 0;
691 				goto done;
692 			}
693 		}
694 
695 		if (ep->is_in)
696 			status = write_fifo(ep, req);
697 		else {
698 			status = read_fifo(ep, req);
699 
700 			/* IN/STATUS stage is otherwise triggered by irq */
701 			if (status && is_ep0)
702 				goto ep0_in_status;
703 		}
704 	} else
705 		status = 0;
706 
707 	if (req && !status) {
708 		list_add_tail (&req->queue, &ep->queue);
709 		at91_udp_write(udc, AT91_UDP_IER, ep->int_mask);
710 	}
711 done:
712 	spin_unlock_irqrestore(&udc->lock, flags);
713 	return (status < 0) ? status : 0;
714 }
715 
716 static int at91_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
717 {
718 	struct at91_ep		*ep;
719 	struct at91_request	*req;
720 	unsigned long		flags;
721 	struct at91_udc		*udc;
722 
723 	ep = container_of(_ep, struct at91_ep, ep);
724 	if (!_ep || ep->ep.name == ep0name)
725 		return -EINVAL;
726 
727 	udc = ep->udc;
728 
729 	spin_lock_irqsave(&udc->lock, flags);
730 
731 	/* make sure it's actually queued on this endpoint */
732 	list_for_each_entry (req, &ep->queue, queue) {
733 		if (&req->req == _req)
734 			break;
735 	}
736 	if (&req->req != _req) {
737 		spin_unlock_irqrestore(&udc->lock, flags);
738 		return -EINVAL;
739 	}
740 
741 	done(ep, req, -ECONNRESET);
742 	spin_unlock_irqrestore(&udc->lock, flags);
743 	return 0;
744 }
745 
746 static int at91_ep_set_halt(struct usb_ep *_ep, int value)
747 {
748 	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
749 	struct at91_udc	*udc = ep->udc;
750 	u32 __iomem	*creg;
751 	u32		csr;
752 	unsigned long	flags;
753 	int		status = 0;
754 
755 	if (!_ep || ep->is_iso || !ep->udc->clocked)
756 		return -EINVAL;
757 
758 	creg = ep->creg;
759 	spin_lock_irqsave(&udc->lock, flags);
760 
761 	csr = __raw_readl(creg);
762 
763 	/*
764 	 * fail with still-busy IN endpoints, ensuring correct sequencing
765 	 * of data tx then stall.  note that the fifo rx bytecount isn't
766 	 * completely accurate as a tx bytecount.
767 	 */
768 	if (ep->is_in && (!list_empty(&ep->queue) || (csr >> 16) != 0))
769 		status = -EAGAIN;
770 	else {
771 		csr |= CLR_FX;
772 		csr &= ~SET_FX;
773 		if (value) {
774 			csr |= AT91_UDP_FORCESTALL;
775 			VDBG("halt %s\n", ep->ep.name);
776 		} else {
777 			at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
778 			at91_udp_write(udc, AT91_UDP_RST_EP, 0);
779 			csr &= ~AT91_UDP_FORCESTALL;
780 		}
781 		__raw_writel(csr, creg);
782 	}
783 
784 	spin_unlock_irqrestore(&udc->lock, flags);
785 	return status;
786 }
787 
788 static const struct usb_ep_ops at91_ep_ops = {
789 	.enable		= at91_ep_enable,
790 	.disable	= at91_ep_disable,
791 	.alloc_request	= at91_ep_alloc_request,
792 	.free_request	= at91_ep_free_request,
793 	.queue		= at91_ep_queue,
794 	.dequeue	= at91_ep_dequeue,
795 	.set_halt	= at91_ep_set_halt,
796 	/* there's only imprecise fifo status reporting */
797 };
798 
799 /*-------------------------------------------------------------------------*/
800 
801 static int at91_get_frame(struct usb_gadget *gadget)
802 {
803 	struct at91_udc *udc = to_udc(gadget);
804 
805 	if (!to_udc(gadget)->clocked)
806 		return -EINVAL;
807 	return at91_udp_read(udc, AT91_UDP_FRM_NUM) & AT91_UDP_NUM;
808 }
809 
810 static int at91_wakeup(struct usb_gadget *gadget)
811 {
812 	struct at91_udc	*udc = to_udc(gadget);
813 	u32		glbstate;
814 	int		status = -EINVAL;
815 	unsigned long	flags;
816 
817 	DBG("%s\n", __func__ );
818 	spin_lock_irqsave(&udc->lock, flags);
819 
820 	if (!udc->clocked || !udc->suspended)
821 		goto done;
822 
823 	/* NOTE:  some "early versions" handle ESR differently ... */
824 
825 	glbstate = at91_udp_read(udc, AT91_UDP_GLB_STAT);
826 	if (!(glbstate & AT91_UDP_ESR))
827 		goto done;
828 	glbstate |= AT91_UDP_ESR;
829 	at91_udp_write(udc, AT91_UDP_GLB_STAT, glbstate);
830 
831 done:
832 	spin_unlock_irqrestore(&udc->lock, flags);
833 	return status;
834 }
835 
836 /* reinit == restore initial software state */
837 static void udc_reinit(struct at91_udc *udc)
838 {
839 	u32 i;
840 
841 	INIT_LIST_HEAD(&udc->gadget.ep_list);
842 	INIT_LIST_HEAD(&udc->gadget.ep0->ep_list);
843 	udc->gadget.quirk_stall_not_supp = 1;
844 
845 	for (i = 0; i < NUM_ENDPOINTS; i++) {
846 		struct at91_ep *ep = &udc->ep[i];
847 
848 		if (i != 0)
849 			list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
850 		ep->ep.desc = NULL;
851 		ep->stopped = 0;
852 		ep->fifo_bank = 0;
853 		usb_ep_set_maxpacket_limit(&ep->ep, ep->maxpacket);
854 		ep->creg = (void __iomem *) udc->udp_baseaddr + AT91_UDP_CSR(i);
855 		/* initialize one queue per endpoint */
856 		INIT_LIST_HEAD(&ep->queue);
857 	}
858 }
859 
860 static void reset_gadget(struct at91_udc *udc)
861 {
862 	struct usb_gadget_driver *driver = udc->driver;
863 	int i;
864 
865 	if (udc->gadget.speed == USB_SPEED_UNKNOWN)
866 		driver = NULL;
867 	udc->gadget.speed = USB_SPEED_UNKNOWN;
868 	udc->suspended = 0;
869 
870 	for (i = 0; i < NUM_ENDPOINTS; i++) {
871 		struct at91_ep *ep = &udc->ep[i];
872 
873 		ep->stopped = 1;
874 		nuke(ep, -ESHUTDOWN);
875 	}
876 	if (driver) {
877 		spin_unlock(&udc->lock);
878 		usb_gadget_udc_reset(&udc->gadget, driver);
879 		spin_lock(&udc->lock);
880 	}
881 
882 	udc_reinit(udc);
883 }
884 
885 static void stop_activity(struct at91_udc *udc)
886 {
887 	struct usb_gadget_driver *driver = udc->driver;
888 	int i;
889 
890 	if (udc->gadget.speed == USB_SPEED_UNKNOWN)
891 		driver = NULL;
892 	udc->gadget.speed = USB_SPEED_UNKNOWN;
893 	udc->suspended = 0;
894 
895 	for (i = 0; i < NUM_ENDPOINTS; i++) {
896 		struct at91_ep *ep = &udc->ep[i];
897 		ep->stopped = 1;
898 		nuke(ep, -ESHUTDOWN);
899 	}
900 	if (driver) {
901 		spin_unlock(&udc->lock);
902 		driver->disconnect(&udc->gadget);
903 		spin_lock(&udc->lock);
904 	}
905 
906 	udc_reinit(udc);
907 }
908 
909 static void clk_on(struct at91_udc *udc)
910 {
911 	if (udc->clocked)
912 		return;
913 	udc->clocked = 1;
914 
915 	clk_enable(udc->iclk);
916 	clk_enable(udc->fclk);
917 }
918 
919 static void clk_off(struct at91_udc *udc)
920 {
921 	if (!udc->clocked)
922 		return;
923 	udc->clocked = 0;
924 	udc->gadget.speed = USB_SPEED_UNKNOWN;
925 	clk_disable(udc->fclk);
926 	clk_disable(udc->iclk);
927 }
928 
929 /*
930  * activate/deactivate link with host; minimize power usage for
931  * inactive links by cutting clocks and transceiver power.
932  */
933 static void pullup(struct at91_udc *udc, int is_on)
934 {
935 	if (!udc->enabled || !udc->vbus)
936 		is_on = 0;
937 	DBG("%sactive\n", is_on ? "" : "in");
938 
939 	if (is_on) {
940 		clk_on(udc);
941 		at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
942 		at91_udp_write(udc, AT91_UDP_TXVC, 0);
943 	} else {
944 		stop_activity(udc);
945 		at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
946 		at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
947 		clk_off(udc);
948 	}
949 
950 	if (udc->caps && udc->caps->pullup)
951 		udc->caps->pullup(udc, is_on);
952 }
953 
954 /* vbus is here!  turn everything on that's ready */
955 static int at91_vbus_session(struct usb_gadget *gadget, int is_active)
956 {
957 	struct at91_udc	*udc = to_udc(gadget);
958 	unsigned long	flags;
959 
960 	/* VDBG("vbus %s\n", is_active ? "on" : "off"); */
961 	spin_lock_irqsave(&udc->lock, flags);
962 	udc->vbus = (is_active != 0);
963 	if (udc->driver)
964 		pullup(udc, is_active);
965 	else
966 		pullup(udc, 0);
967 	spin_unlock_irqrestore(&udc->lock, flags);
968 	return 0;
969 }
970 
971 static int at91_pullup(struct usb_gadget *gadget, int is_on)
972 {
973 	struct at91_udc	*udc = to_udc(gadget);
974 	unsigned long	flags;
975 
976 	spin_lock_irqsave(&udc->lock, flags);
977 	udc->enabled = is_on = !!is_on;
978 	pullup(udc, is_on);
979 	spin_unlock_irqrestore(&udc->lock, flags);
980 	return 0;
981 }
982 
983 static int at91_set_selfpowered(struct usb_gadget *gadget, int is_on)
984 {
985 	struct at91_udc	*udc = to_udc(gadget);
986 	unsigned long	flags;
987 
988 	spin_lock_irqsave(&udc->lock, flags);
989 	gadget->is_selfpowered = (is_on != 0);
990 	spin_unlock_irqrestore(&udc->lock, flags);
991 	return 0;
992 }
993 
994 static int at91_start(struct usb_gadget *gadget,
995 		struct usb_gadget_driver *driver);
996 static int at91_stop(struct usb_gadget *gadget);
997 
998 static const struct usb_gadget_ops at91_udc_ops = {
999 	.get_frame		= at91_get_frame,
1000 	.wakeup			= at91_wakeup,
1001 	.set_selfpowered	= at91_set_selfpowered,
1002 	.vbus_session		= at91_vbus_session,
1003 	.pullup			= at91_pullup,
1004 	.udc_start		= at91_start,
1005 	.udc_stop		= at91_stop,
1006 
1007 	/*
1008 	 * VBUS-powered devices may also also want to support bigger
1009 	 * power budgets after an appropriate SET_CONFIGURATION.
1010 	 */
1011 	/* .vbus_power		= at91_vbus_power, */
1012 };
1013 
1014 /*-------------------------------------------------------------------------*/
1015 
1016 static int handle_ep(struct at91_ep *ep)
1017 {
1018 	struct at91_request	*req;
1019 	u32 __iomem		*creg = ep->creg;
1020 	u32			csr = __raw_readl(creg);
1021 
1022 	if (!list_empty(&ep->queue))
1023 		req = list_entry(ep->queue.next,
1024 			struct at91_request, queue);
1025 	else
1026 		req = NULL;
1027 
1028 	if (ep->is_in) {
1029 		if (csr & (AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)) {
1030 			csr |= CLR_FX;
1031 			csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_TXCOMP);
1032 			__raw_writel(csr, creg);
1033 		}
1034 		if (req)
1035 			return write_fifo(ep, req);
1036 
1037 	} else {
1038 		if (csr & AT91_UDP_STALLSENT) {
1039 			/* STALLSENT bit == ISOERR */
1040 			if (ep->is_iso && req)
1041 				req->req.status = -EILSEQ;
1042 			csr |= CLR_FX;
1043 			csr &= ~(SET_FX | AT91_UDP_STALLSENT);
1044 			__raw_writel(csr, creg);
1045 			csr = __raw_readl(creg);
1046 		}
1047 		if (req && (csr & RX_DATA_READY))
1048 			return read_fifo(ep, req);
1049 	}
1050 	return 0;
1051 }
1052 
1053 union setup {
1054 	u8			raw[8];
1055 	struct usb_ctrlrequest	r;
1056 };
1057 
1058 static void handle_setup(struct at91_udc *udc, struct at91_ep *ep, u32 csr)
1059 {
1060 	u32 __iomem	*creg = ep->creg;
1061 	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
1062 	unsigned	rxcount, i = 0;
1063 	u32		tmp;
1064 	union setup	pkt;
1065 	int		status = 0;
1066 
1067 	/* read and ack SETUP; hard-fail for bogus packets */
1068 	rxcount = (csr & AT91_UDP_RXBYTECNT) >> 16;
1069 	if (likely(rxcount == 8)) {
1070 		while (rxcount--)
1071 			pkt.raw[i++] = __raw_readb(dreg);
1072 		if (pkt.r.bRequestType & USB_DIR_IN) {
1073 			csr |= AT91_UDP_DIR;
1074 			ep->is_in = 1;
1075 		} else {
1076 			csr &= ~AT91_UDP_DIR;
1077 			ep->is_in = 0;
1078 		}
1079 	} else {
1080 		/* REVISIT this happens sometimes under load; why?? */
1081 		ERR("SETUP len %d, csr %08x\n", rxcount, csr);
1082 		status = -EINVAL;
1083 	}
1084 	csr |= CLR_FX;
1085 	csr &= ~(SET_FX | AT91_UDP_RXSETUP);
1086 	__raw_writel(csr, creg);
1087 	udc->wait_for_addr_ack = 0;
1088 	udc->wait_for_config_ack = 0;
1089 	ep->stopped = 0;
1090 	if (unlikely(status != 0))
1091 		goto stall;
1092 
1093 #define w_index		le16_to_cpu(pkt.r.wIndex)
1094 #define w_value		le16_to_cpu(pkt.r.wValue)
1095 #define w_length	le16_to_cpu(pkt.r.wLength)
1096 
1097 	VDBG("SETUP %02x.%02x v%04x i%04x l%04x\n",
1098 			pkt.r.bRequestType, pkt.r.bRequest,
1099 			w_value, w_index, w_length);
1100 
1101 	/*
1102 	 * A few standard requests get handled here, ones that touch
1103 	 * hardware ... notably for device and endpoint features.
1104 	 */
1105 	udc->req_pending = 1;
1106 	csr = __raw_readl(creg);
1107 	csr |= CLR_FX;
1108 	csr &= ~SET_FX;
1109 	switch ((pkt.r.bRequestType << 8) | pkt.r.bRequest) {
1110 
1111 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1112 			| USB_REQ_SET_ADDRESS:
1113 		__raw_writel(csr | AT91_UDP_TXPKTRDY, creg);
1114 		udc->addr = w_value;
1115 		udc->wait_for_addr_ack = 1;
1116 		udc->req_pending = 0;
1117 		/* FADDR is set later, when we ack host STATUS */
1118 		return;
1119 
1120 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1121 			| USB_REQ_SET_CONFIGURATION:
1122 		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_CONFG;
1123 		if (pkt.r.wValue)
1124 			udc->wait_for_config_ack = (tmp == 0);
1125 		else
1126 			udc->wait_for_config_ack = (tmp != 0);
1127 		if (udc->wait_for_config_ack)
1128 			VDBG("wait for config\n");
1129 		/* CONFG is toggled later, if gadget driver succeeds */
1130 		break;
1131 
1132 	/*
1133 	 * Hosts may set or clear remote wakeup status, and
1134 	 * devices may report they're VBUS powered.
1135 	 */
1136 	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1137 			| USB_REQ_GET_STATUS:
1138 		tmp = (udc->gadget.is_selfpowered << USB_DEVICE_SELF_POWERED);
1139 		if (at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_ESR)
1140 			tmp |= (1 << USB_DEVICE_REMOTE_WAKEUP);
1141 		PACKET("get device status\n");
1142 		__raw_writeb(tmp, dreg);
1143 		__raw_writeb(0, dreg);
1144 		goto write_in;
1145 		/* then STATUS starts later, automatically */
1146 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1147 			| USB_REQ_SET_FEATURE:
1148 		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
1149 			goto stall;
1150 		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
1151 		tmp |= AT91_UDP_ESR;
1152 		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
1153 		goto succeed;
1154 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1155 			| USB_REQ_CLEAR_FEATURE:
1156 		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
1157 			goto stall;
1158 		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
1159 		tmp &= ~AT91_UDP_ESR;
1160 		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
1161 		goto succeed;
1162 
1163 	/*
1164 	 * Interfaces have no feature settings; this is pretty useless.
1165 	 * we won't even insist the interface exists...
1166 	 */
1167 	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
1168 			| USB_REQ_GET_STATUS:
1169 		PACKET("get interface status\n");
1170 		__raw_writeb(0, dreg);
1171 		__raw_writeb(0, dreg);
1172 		goto write_in;
1173 		/* then STATUS starts later, automatically */
1174 	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
1175 			| USB_REQ_SET_FEATURE:
1176 	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
1177 			| USB_REQ_CLEAR_FEATURE:
1178 		goto stall;
1179 
1180 	/*
1181 	 * Hosts may clear bulk/intr endpoint halt after the gadget
1182 	 * driver sets it (not widely used); or set it (for testing)
1183 	 */
1184 	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
1185 			| USB_REQ_GET_STATUS:
1186 		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
1187 		ep = &udc->ep[tmp];
1188 		if (tmp >= NUM_ENDPOINTS || (tmp && !ep->ep.desc))
1189 			goto stall;
1190 
1191 		if (tmp) {
1192 			if ((w_index & USB_DIR_IN)) {
1193 				if (!ep->is_in)
1194 					goto stall;
1195 			} else if (ep->is_in)
1196 				goto stall;
1197 		}
1198 		PACKET("get %s status\n", ep->ep.name);
1199 		if (__raw_readl(ep->creg) & AT91_UDP_FORCESTALL)
1200 			tmp = (1 << USB_ENDPOINT_HALT);
1201 		else
1202 			tmp = 0;
1203 		__raw_writeb(tmp, dreg);
1204 		__raw_writeb(0, dreg);
1205 		goto write_in;
1206 		/* then STATUS starts later, automatically */
1207 	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
1208 			| USB_REQ_SET_FEATURE:
1209 		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
1210 		ep = &udc->ep[tmp];
1211 		if (w_value != USB_ENDPOINT_HALT || tmp >= NUM_ENDPOINTS)
1212 			goto stall;
1213 		if (!ep->ep.desc || ep->is_iso)
1214 			goto stall;
1215 		if ((w_index & USB_DIR_IN)) {
1216 			if (!ep->is_in)
1217 				goto stall;
1218 		} else if (ep->is_in)
1219 			goto stall;
1220 
1221 		tmp = __raw_readl(ep->creg);
1222 		tmp &= ~SET_FX;
1223 		tmp |= CLR_FX | AT91_UDP_FORCESTALL;
1224 		__raw_writel(tmp, ep->creg);
1225 		goto succeed;
1226 	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
1227 			| USB_REQ_CLEAR_FEATURE:
1228 		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
1229 		ep = &udc->ep[tmp];
1230 		if (w_value != USB_ENDPOINT_HALT || tmp >= NUM_ENDPOINTS)
1231 			goto stall;
1232 		if (tmp == 0)
1233 			goto succeed;
1234 		if (!ep->ep.desc || ep->is_iso)
1235 			goto stall;
1236 		if ((w_index & USB_DIR_IN)) {
1237 			if (!ep->is_in)
1238 				goto stall;
1239 		} else if (ep->is_in)
1240 			goto stall;
1241 
1242 		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
1243 		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
1244 		tmp = __raw_readl(ep->creg);
1245 		tmp |= CLR_FX;
1246 		tmp &= ~(SET_FX | AT91_UDP_FORCESTALL);
1247 		__raw_writel(tmp, ep->creg);
1248 		if (!list_empty(&ep->queue))
1249 			handle_ep(ep);
1250 		goto succeed;
1251 	}
1252 
1253 #undef w_value
1254 #undef w_index
1255 #undef w_length
1256 
1257 	/* pass request up to the gadget driver */
1258 	if (udc->driver) {
1259 		spin_unlock(&udc->lock);
1260 		status = udc->driver->setup(&udc->gadget, &pkt.r);
1261 		spin_lock(&udc->lock);
1262 	}
1263 	else
1264 		status = -ENODEV;
1265 	if (status < 0) {
1266 stall:
1267 		VDBG("req %02x.%02x protocol STALL; stat %d\n",
1268 				pkt.r.bRequestType, pkt.r.bRequest, status);
1269 		csr |= AT91_UDP_FORCESTALL;
1270 		__raw_writel(csr, creg);
1271 		udc->req_pending = 0;
1272 	}
1273 	return;
1274 
1275 succeed:
1276 	/* immediate successful (IN) STATUS after zero length DATA */
1277 	PACKET("ep0 in/status\n");
1278 write_in:
1279 	csr |= AT91_UDP_TXPKTRDY;
1280 	__raw_writel(csr, creg);
1281 	udc->req_pending = 0;
1282 }
1283 
1284 static void handle_ep0(struct at91_udc *udc)
1285 {
1286 	struct at91_ep		*ep0 = &udc->ep[0];
1287 	u32 __iomem		*creg = ep0->creg;
1288 	u32			csr = __raw_readl(creg);
1289 	struct at91_request	*req;
1290 
1291 	if (unlikely(csr & AT91_UDP_STALLSENT)) {
1292 		nuke(ep0, -EPROTO);
1293 		udc->req_pending = 0;
1294 		csr |= CLR_FX;
1295 		csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_FORCESTALL);
1296 		__raw_writel(csr, creg);
1297 		VDBG("ep0 stalled\n");
1298 		csr = __raw_readl(creg);
1299 	}
1300 	if (csr & AT91_UDP_RXSETUP) {
1301 		nuke(ep0, 0);
1302 		udc->req_pending = 0;
1303 		handle_setup(udc, ep0, csr);
1304 		return;
1305 	}
1306 
1307 	if (list_empty(&ep0->queue))
1308 		req = NULL;
1309 	else
1310 		req = list_entry(ep0->queue.next, struct at91_request, queue);
1311 
1312 	/* host ACKed an IN packet that we sent */
1313 	if (csr & AT91_UDP_TXCOMP) {
1314 		csr |= CLR_FX;
1315 		csr &= ~(SET_FX | AT91_UDP_TXCOMP);
1316 
1317 		/* write more IN DATA? */
1318 		if (req && ep0->is_in) {
1319 			if (handle_ep(ep0))
1320 				udc->req_pending = 0;
1321 
1322 		/*
1323 		 * Ack after:
1324 		 *  - last IN DATA packet (including GET_STATUS)
1325 		 *  - IN/STATUS for OUT DATA
1326 		 *  - IN/STATUS for any zero-length DATA stage
1327 		 * except for the IN DATA case, the host should send
1328 		 * an OUT status later, which we'll ack.
1329 		 */
1330 		} else {
1331 			udc->req_pending = 0;
1332 			__raw_writel(csr, creg);
1333 
1334 			/*
1335 			 * SET_ADDRESS takes effect only after the STATUS
1336 			 * (to the original address) gets acked.
1337 			 */
1338 			if (udc->wait_for_addr_ack) {
1339 				u32	tmp;
1340 
1341 				at91_udp_write(udc, AT91_UDP_FADDR,
1342 						AT91_UDP_FEN | udc->addr);
1343 				tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
1344 				tmp &= ~AT91_UDP_FADDEN;
1345 				if (udc->addr)
1346 					tmp |= AT91_UDP_FADDEN;
1347 				at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
1348 
1349 				udc->wait_for_addr_ack = 0;
1350 				VDBG("address %d\n", udc->addr);
1351 			}
1352 		}
1353 	}
1354 
1355 	/* OUT packet arrived ... */
1356 	else if (csr & AT91_UDP_RX_DATA_BK0) {
1357 		csr |= CLR_FX;
1358 		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
1359 
1360 		/* OUT DATA stage */
1361 		if (!ep0->is_in) {
1362 			if (req) {
1363 				if (handle_ep(ep0)) {
1364 					/* send IN/STATUS */
1365 					PACKET("ep0 in/status\n");
1366 					csr = __raw_readl(creg);
1367 					csr &= ~SET_FX;
1368 					csr |= CLR_FX | AT91_UDP_TXPKTRDY;
1369 					__raw_writel(csr, creg);
1370 					udc->req_pending = 0;
1371 				}
1372 			} else if (udc->req_pending) {
1373 				/*
1374 				 * AT91 hardware has a hard time with this
1375 				 * "deferred response" mode for control-OUT
1376 				 * transfers.  (For control-IN it's fine.)
1377 				 *
1378 				 * The normal solution leaves OUT data in the
1379 				 * fifo until the gadget driver is ready.
1380 				 * We couldn't do that here without disabling
1381 				 * the IRQ that tells about SETUP packets,
1382 				 * e.g. when the host gets impatient...
1383 				 *
1384 				 * Working around it by copying into a buffer
1385 				 * would almost be a non-deferred response,
1386 				 * except that it wouldn't permit reliable
1387 				 * stalling of the request.  Instead, demand
1388 				 * that gadget drivers not use this mode.
1389 				 */
1390 				DBG("no control-OUT deferred responses!\n");
1391 				__raw_writel(csr | AT91_UDP_FORCESTALL, creg);
1392 				udc->req_pending = 0;
1393 			}
1394 
1395 		/* STATUS stage for control-IN; ack.  */
1396 		} else {
1397 			PACKET("ep0 out/status ACK\n");
1398 			__raw_writel(csr, creg);
1399 
1400 			/* "early" status stage */
1401 			if (req)
1402 				done(ep0, req, 0);
1403 		}
1404 	}
1405 }
1406 
1407 static irqreturn_t at91_udc_irq (int irq, void *_udc)
1408 {
1409 	struct at91_udc		*udc = _udc;
1410 	u32			rescans = 5;
1411 	int			disable_clock = 0;
1412 	unsigned long		flags;
1413 
1414 	spin_lock_irqsave(&udc->lock, flags);
1415 
1416 	if (!udc->clocked) {
1417 		clk_on(udc);
1418 		disable_clock = 1;
1419 	}
1420 
1421 	while (rescans--) {
1422 		u32 status;
1423 
1424 		status = at91_udp_read(udc, AT91_UDP_ISR)
1425 			& at91_udp_read(udc, AT91_UDP_IMR);
1426 		if (!status)
1427 			break;
1428 
1429 		/* USB reset irq:  not maskable */
1430 		if (status & AT91_UDP_ENDBUSRES) {
1431 			at91_udp_write(udc, AT91_UDP_IDR, ~MINIMUS_INTERRUPTUS);
1432 			at91_udp_write(udc, AT91_UDP_IER, MINIMUS_INTERRUPTUS);
1433 			/* Atmel code clears this irq twice */
1434 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
1435 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
1436 			VDBG("end bus reset\n");
1437 			udc->addr = 0;
1438 			reset_gadget(udc);
1439 
1440 			/* enable ep0 */
1441 			at91_udp_write(udc, AT91_UDP_CSR(0),
1442 					AT91_UDP_EPEDS | AT91_UDP_EPTYPE_CTRL);
1443 			udc->gadget.speed = USB_SPEED_FULL;
1444 			udc->suspended = 0;
1445 			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_EP(0));
1446 
1447 			/*
1448 			 * NOTE:  this driver keeps clocks off unless the
1449 			 * USB host is present.  That saves power, but for
1450 			 * boards that don't support VBUS detection, both
1451 			 * clocks need to be active most of the time.
1452 			 */
1453 
1454 		/* host initiated suspend (3+ms bus idle) */
1455 		} else if (status & AT91_UDP_RXSUSP) {
1456 			at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXSUSP);
1457 			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXRSM);
1458 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXSUSP);
1459 			/* VDBG("bus suspend\n"); */
1460 			if (udc->suspended)
1461 				continue;
1462 			udc->suspended = 1;
1463 
1464 			/*
1465 			 * NOTE:  when suspending a VBUS-powered device, the
1466 			 * gadget driver should switch into slow clock mode
1467 			 * and then into standby to avoid drawing more than
1468 			 * 500uA power (2500uA for some high-power configs).
1469 			 */
1470 			if (udc->driver && udc->driver->suspend) {
1471 				spin_unlock(&udc->lock);
1472 				udc->driver->suspend(&udc->gadget);
1473 				spin_lock(&udc->lock);
1474 			}
1475 
1476 		/* host initiated resume */
1477 		} else if (status & AT91_UDP_RXRSM) {
1478 			at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
1479 			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXSUSP);
1480 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
1481 			/* VDBG("bus resume\n"); */
1482 			if (!udc->suspended)
1483 				continue;
1484 			udc->suspended = 0;
1485 
1486 			/*
1487 			 * NOTE:  for a VBUS-powered device, the gadget driver
1488 			 * would normally want to switch out of slow clock
1489 			 * mode into normal mode.
1490 			 */
1491 			if (udc->driver && udc->driver->resume) {
1492 				spin_unlock(&udc->lock);
1493 				udc->driver->resume(&udc->gadget);
1494 				spin_lock(&udc->lock);
1495 			}
1496 
1497 		/* endpoint IRQs are cleared by handling them */
1498 		} else {
1499 			int		i;
1500 			unsigned	mask = 1;
1501 			struct at91_ep	*ep = &udc->ep[1];
1502 
1503 			if (status & mask)
1504 				handle_ep0(udc);
1505 			for (i = 1; i < NUM_ENDPOINTS; i++) {
1506 				mask <<= 1;
1507 				if (status & mask)
1508 					handle_ep(ep);
1509 				ep++;
1510 			}
1511 		}
1512 	}
1513 
1514 	if (disable_clock)
1515 		clk_off(udc);
1516 
1517 	spin_unlock_irqrestore(&udc->lock, flags);
1518 
1519 	return IRQ_HANDLED;
1520 }
1521 
1522 /*-------------------------------------------------------------------------*/
1523 
1524 static void at91_vbus_update(struct at91_udc *udc, unsigned value)
1525 {
1526 	value ^= udc->board.vbus_active_low;
1527 	if (value != udc->vbus)
1528 		at91_vbus_session(&udc->gadget, value);
1529 }
1530 
1531 static irqreturn_t at91_vbus_irq(int irq, void *_udc)
1532 {
1533 	struct at91_udc	*udc = _udc;
1534 
1535 	/* vbus needs at least brief debouncing */
1536 	udelay(10);
1537 	at91_vbus_update(udc, gpio_get_value(udc->board.vbus_pin));
1538 
1539 	return IRQ_HANDLED;
1540 }
1541 
1542 static void at91_vbus_timer_work(struct work_struct *work)
1543 {
1544 	struct at91_udc *udc = container_of(work, struct at91_udc,
1545 					    vbus_timer_work);
1546 
1547 	at91_vbus_update(udc, gpio_get_value_cansleep(udc->board.vbus_pin));
1548 
1549 	if (!timer_pending(&udc->vbus_timer))
1550 		mod_timer(&udc->vbus_timer, jiffies + VBUS_POLL_TIMEOUT);
1551 }
1552 
1553 static void at91_vbus_timer(struct timer_list *t)
1554 {
1555 	struct at91_udc *udc = from_timer(udc, t, vbus_timer);
1556 
1557 	/*
1558 	 * If we are polling vbus it is likely that the gpio is on an
1559 	 * bus such as i2c or spi which may sleep, so schedule some work
1560 	 * to read the vbus gpio
1561 	 */
1562 	schedule_work(&udc->vbus_timer_work);
1563 }
1564 
1565 static int at91_start(struct usb_gadget *gadget,
1566 		struct usb_gadget_driver *driver)
1567 {
1568 	struct at91_udc	*udc;
1569 
1570 	udc = container_of(gadget, struct at91_udc, gadget);
1571 	udc->driver = driver;
1572 	udc->gadget.dev.of_node = udc->pdev->dev.of_node;
1573 	udc->enabled = 1;
1574 	udc->gadget.is_selfpowered = 1;
1575 
1576 	return 0;
1577 }
1578 
1579 static int at91_stop(struct usb_gadget *gadget)
1580 {
1581 	struct at91_udc *udc;
1582 	unsigned long	flags;
1583 
1584 	udc = container_of(gadget, struct at91_udc, gadget);
1585 	spin_lock_irqsave(&udc->lock, flags);
1586 	udc->enabled = 0;
1587 	at91_udp_write(udc, AT91_UDP_IDR, ~0);
1588 	spin_unlock_irqrestore(&udc->lock, flags);
1589 
1590 	udc->driver = NULL;
1591 
1592 	return 0;
1593 }
1594 
1595 /*-------------------------------------------------------------------------*/
1596 
1597 static void at91udc_shutdown(struct platform_device *dev)
1598 {
1599 	struct at91_udc *udc = platform_get_drvdata(dev);
1600 	unsigned long	flags;
1601 
1602 	/* force disconnect on reboot */
1603 	spin_lock_irqsave(&udc->lock, flags);
1604 	pullup(platform_get_drvdata(dev), 0);
1605 	spin_unlock_irqrestore(&udc->lock, flags);
1606 }
1607 
1608 static int at91rm9200_udc_init(struct at91_udc *udc)
1609 {
1610 	struct at91_ep *ep;
1611 	int ret;
1612 	int i;
1613 
1614 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1615 		ep = &udc->ep[i];
1616 
1617 		switch (i) {
1618 		case 0:
1619 		case 3:
1620 			ep->maxpacket = 8;
1621 			break;
1622 		case 1 ... 2:
1623 			ep->maxpacket = 64;
1624 			break;
1625 		case 4 ... 5:
1626 			ep->maxpacket = 256;
1627 			break;
1628 		}
1629 	}
1630 
1631 	if (!gpio_is_valid(udc->board.pullup_pin)) {
1632 		DBG("no D+ pullup?\n");
1633 		return -ENODEV;
1634 	}
1635 
1636 	ret = devm_gpio_request(&udc->pdev->dev, udc->board.pullup_pin,
1637 				"udc_pullup");
1638 	if (ret) {
1639 		DBG("D+ pullup is busy\n");
1640 		return ret;
1641 	}
1642 
1643 	gpio_direction_output(udc->board.pullup_pin,
1644 			      udc->board.pullup_active_low);
1645 
1646 	return 0;
1647 }
1648 
1649 static void at91rm9200_udc_pullup(struct at91_udc *udc, int is_on)
1650 {
1651 	int active = !udc->board.pullup_active_low;
1652 
1653 	if (is_on)
1654 		gpio_set_value(udc->board.pullup_pin, active);
1655 	else
1656 		gpio_set_value(udc->board.pullup_pin, !active);
1657 }
1658 
1659 static const struct at91_udc_caps at91rm9200_udc_caps = {
1660 	.init = at91rm9200_udc_init,
1661 	.pullup = at91rm9200_udc_pullup,
1662 };
1663 
1664 static int at91sam9260_udc_init(struct at91_udc *udc)
1665 {
1666 	struct at91_ep *ep;
1667 	int i;
1668 
1669 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1670 		ep = &udc->ep[i];
1671 
1672 		switch (i) {
1673 		case 0 ... 3:
1674 			ep->maxpacket = 64;
1675 			break;
1676 		case 4 ... 5:
1677 			ep->maxpacket = 512;
1678 			break;
1679 		}
1680 	}
1681 
1682 	return 0;
1683 }
1684 
1685 static void at91sam9260_udc_pullup(struct at91_udc *udc, int is_on)
1686 {
1687 	u32 txvc = at91_udp_read(udc, AT91_UDP_TXVC);
1688 
1689 	if (is_on)
1690 		txvc |= AT91_UDP_TXVC_PUON;
1691 	else
1692 		txvc &= ~AT91_UDP_TXVC_PUON;
1693 
1694 	at91_udp_write(udc, AT91_UDP_TXVC, txvc);
1695 }
1696 
1697 static const struct at91_udc_caps at91sam9260_udc_caps = {
1698 	.init = at91sam9260_udc_init,
1699 	.pullup = at91sam9260_udc_pullup,
1700 };
1701 
1702 static int at91sam9261_udc_init(struct at91_udc *udc)
1703 {
1704 	struct at91_ep *ep;
1705 	int i;
1706 
1707 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1708 		ep = &udc->ep[i];
1709 
1710 		switch (i) {
1711 		case 0:
1712 			ep->maxpacket = 8;
1713 			break;
1714 		case 1 ... 3:
1715 			ep->maxpacket = 64;
1716 			break;
1717 		case 4 ... 5:
1718 			ep->maxpacket = 256;
1719 			break;
1720 		}
1721 	}
1722 
1723 	udc->matrix = syscon_regmap_lookup_by_phandle(udc->pdev->dev.of_node,
1724 						      "atmel,matrix");
1725 	return PTR_ERR_OR_ZERO(udc->matrix);
1726 }
1727 
1728 static void at91sam9261_udc_pullup(struct at91_udc *udc, int is_on)
1729 {
1730 	u32 usbpucr = 0;
1731 
1732 	if (is_on)
1733 		usbpucr = AT91_MATRIX_USBPUCR_PUON;
1734 
1735 	regmap_update_bits(udc->matrix, AT91SAM9261_MATRIX_USBPUCR,
1736 			   AT91_MATRIX_USBPUCR_PUON, usbpucr);
1737 }
1738 
1739 static const struct at91_udc_caps at91sam9261_udc_caps = {
1740 	.init = at91sam9261_udc_init,
1741 	.pullup = at91sam9261_udc_pullup,
1742 };
1743 
1744 static int at91sam9263_udc_init(struct at91_udc *udc)
1745 {
1746 	struct at91_ep *ep;
1747 	int i;
1748 
1749 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1750 		ep = &udc->ep[i];
1751 
1752 		switch (i) {
1753 		case 0:
1754 		case 1:
1755 		case 2:
1756 		case 3:
1757 			ep->maxpacket = 64;
1758 			break;
1759 		case 4:
1760 		case 5:
1761 			ep->maxpacket = 256;
1762 			break;
1763 		}
1764 	}
1765 
1766 	return 0;
1767 }
1768 
1769 static const struct at91_udc_caps at91sam9263_udc_caps = {
1770 	.init = at91sam9263_udc_init,
1771 	.pullup = at91sam9260_udc_pullup,
1772 };
1773 
1774 static const struct of_device_id at91_udc_dt_ids[] = {
1775 	{
1776 		.compatible = "atmel,at91rm9200-udc",
1777 		.data = &at91rm9200_udc_caps,
1778 	},
1779 	{
1780 		.compatible = "atmel,at91sam9260-udc",
1781 		.data = &at91sam9260_udc_caps,
1782 	},
1783 	{
1784 		.compatible = "atmel,at91sam9261-udc",
1785 		.data = &at91sam9261_udc_caps,
1786 	},
1787 	{
1788 		.compatible = "atmel,at91sam9263-udc",
1789 		.data = &at91sam9263_udc_caps,
1790 	},
1791 	{ /* sentinel */ }
1792 };
1793 MODULE_DEVICE_TABLE(of, at91_udc_dt_ids);
1794 
1795 static void at91udc_of_init(struct at91_udc *udc, struct device_node *np)
1796 {
1797 	struct at91_udc_data *board = &udc->board;
1798 	const struct of_device_id *match;
1799 	enum of_gpio_flags flags;
1800 	u32 val;
1801 
1802 	if (of_property_read_u32(np, "atmel,vbus-polled", &val) == 0)
1803 		board->vbus_polled = 1;
1804 
1805 	board->vbus_pin = of_get_named_gpio_flags(np, "atmel,vbus-gpio", 0,
1806 						  &flags);
1807 	board->vbus_active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
1808 
1809 	board->pullup_pin = of_get_named_gpio_flags(np, "atmel,pullup-gpio", 0,
1810 						  &flags);
1811 
1812 	board->pullup_active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
1813 
1814 	match = of_match_node(at91_udc_dt_ids, np);
1815 	if (match)
1816 		udc->caps = match->data;
1817 }
1818 
1819 static int at91udc_probe(struct platform_device *pdev)
1820 {
1821 	struct device	*dev = &pdev->dev;
1822 	struct at91_udc	*udc;
1823 	int		retval;
1824 	struct resource	*res;
1825 	struct at91_ep	*ep;
1826 	int		i;
1827 
1828 	udc = devm_kzalloc(dev, sizeof(*udc), GFP_KERNEL);
1829 	if (!udc)
1830 		return -ENOMEM;
1831 
1832 	/* init software state */
1833 	udc->gadget.dev.parent = dev;
1834 	at91udc_of_init(udc, pdev->dev.of_node);
1835 	udc->pdev = pdev;
1836 	udc->enabled = 0;
1837 	spin_lock_init(&udc->lock);
1838 
1839 	udc->gadget.ops = &at91_udc_ops;
1840 	udc->gadget.ep0 = &udc->ep[0].ep;
1841 	udc->gadget.name = driver_name;
1842 	udc->gadget.dev.init_name = "gadget";
1843 
1844 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1845 		ep = &udc->ep[i];
1846 		ep->ep.name = ep_info[i].name;
1847 		ep->ep.caps = ep_info[i].caps;
1848 		ep->ep.ops = &at91_ep_ops;
1849 		ep->udc = udc;
1850 		ep->int_mask = BIT(i);
1851 		if (i != 0 && i != 3)
1852 			ep->is_pingpong = 1;
1853 	}
1854 
1855 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1856 	udc->udp_baseaddr = devm_ioremap_resource(dev, res);
1857 	if (IS_ERR(udc->udp_baseaddr))
1858 		return PTR_ERR(udc->udp_baseaddr);
1859 
1860 	if (udc->caps && udc->caps->init) {
1861 		retval = udc->caps->init(udc);
1862 		if (retval)
1863 			return retval;
1864 	}
1865 
1866 	udc_reinit(udc);
1867 
1868 	/* get interface and function clocks */
1869 	udc->iclk = devm_clk_get(dev, "pclk");
1870 	if (IS_ERR(udc->iclk))
1871 		return PTR_ERR(udc->iclk);
1872 
1873 	udc->fclk = devm_clk_get(dev, "hclk");
1874 	if (IS_ERR(udc->fclk))
1875 		return PTR_ERR(udc->fclk);
1876 
1877 	/* don't do anything until we have both gadget driver and VBUS */
1878 	clk_set_rate(udc->fclk, 48000000);
1879 	retval = clk_prepare(udc->fclk);
1880 	if (retval)
1881 		return retval;
1882 
1883 	retval = clk_prepare_enable(udc->iclk);
1884 	if (retval)
1885 		goto err_unprepare_fclk;
1886 
1887 	at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
1888 	at91_udp_write(udc, AT91_UDP_IDR, 0xffffffff);
1889 	/* Clear all pending interrupts - UDP may be used by bootloader. */
1890 	at91_udp_write(udc, AT91_UDP_ICR, 0xffffffff);
1891 	clk_disable(udc->iclk);
1892 
1893 	/* request UDC and maybe VBUS irqs */
1894 	udc->udp_irq = platform_get_irq(pdev, 0);
1895 	retval = devm_request_irq(dev, udc->udp_irq, at91_udc_irq, 0,
1896 				  driver_name, udc);
1897 	if (retval) {
1898 		DBG("request irq %d failed\n", udc->udp_irq);
1899 		goto err_unprepare_iclk;
1900 	}
1901 
1902 	if (gpio_is_valid(udc->board.vbus_pin)) {
1903 		retval = devm_gpio_request(dev, udc->board.vbus_pin,
1904 					   "udc_vbus");
1905 		if (retval) {
1906 			DBG("request vbus pin failed\n");
1907 			goto err_unprepare_iclk;
1908 		}
1909 
1910 		gpio_direction_input(udc->board.vbus_pin);
1911 
1912 		/*
1913 		 * Get the initial state of VBUS - we cannot expect
1914 		 * a pending interrupt.
1915 		 */
1916 		udc->vbus = gpio_get_value_cansleep(udc->board.vbus_pin) ^
1917 			udc->board.vbus_active_low;
1918 
1919 		if (udc->board.vbus_polled) {
1920 			INIT_WORK(&udc->vbus_timer_work, at91_vbus_timer_work);
1921 			timer_setup(&udc->vbus_timer, at91_vbus_timer, 0);
1922 			mod_timer(&udc->vbus_timer,
1923 				  jiffies + VBUS_POLL_TIMEOUT);
1924 		} else {
1925 			retval = devm_request_irq(dev,
1926 					gpio_to_irq(udc->board.vbus_pin),
1927 					at91_vbus_irq, 0, driver_name, udc);
1928 			if (retval) {
1929 				DBG("request vbus irq %d failed\n",
1930 				    udc->board.vbus_pin);
1931 				goto err_unprepare_iclk;
1932 			}
1933 		}
1934 	} else {
1935 		DBG("no VBUS detection, assuming always-on\n");
1936 		udc->vbus = 1;
1937 	}
1938 	retval = usb_add_gadget_udc(dev, &udc->gadget);
1939 	if (retval)
1940 		goto err_unprepare_iclk;
1941 	dev_set_drvdata(dev, udc);
1942 	device_init_wakeup(dev, 1);
1943 	create_debug_file(udc);
1944 
1945 	INFO("%s version %s\n", driver_name, DRIVER_VERSION);
1946 	return 0;
1947 
1948 err_unprepare_iclk:
1949 	clk_unprepare(udc->iclk);
1950 err_unprepare_fclk:
1951 	clk_unprepare(udc->fclk);
1952 
1953 	DBG("%s probe failed, %d\n", driver_name, retval);
1954 
1955 	return retval;
1956 }
1957 
1958 static int at91udc_remove(struct platform_device *pdev)
1959 {
1960 	struct at91_udc *udc = platform_get_drvdata(pdev);
1961 	unsigned long	flags;
1962 
1963 	DBG("remove\n");
1964 
1965 	usb_del_gadget_udc(&udc->gadget);
1966 	if (udc->driver)
1967 		return -EBUSY;
1968 
1969 	spin_lock_irqsave(&udc->lock, flags);
1970 	pullup(udc, 0);
1971 	spin_unlock_irqrestore(&udc->lock, flags);
1972 
1973 	device_init_wakeup(&pdev->dev, 0);
1974 	remove_debug_file(udc);
1975 	clk_unprepare(udc->fclk);
1976 	clk_unprepare(udc->iclk);
1977 
1978 	return 0;
1979 }
1980 
1981 #ifdef CONFIG_PM
1982 static int at91udc_suspend(struct platform_device *pdev, pm_message_t mesg)
1983 {
1984 	struct at91_udc *udc = platform_get_drvdata(pdev);
1985 	int		wake = udc->driver && device_may_wakeup(&pdev->dev);
1986 	unsigned long	flags;
1987 
1988 	/* Unless we can act normally to the host (letting it wake us up
1989 	 * whenever it has work for us) force disconnect.  Wakeup requires
1990 	 * PLLB for USB events (signaling for reset, wakeup, or incoming
1991 	 * tokens) and VBUS irqs (on systems which support them).
1992 	 */
1993 	if ((!udc->suspended && udc->addr)
1994 			|| !wake
1995 			|| at91_suspend_entering_slow_clock()) {
1996 		spin_lock_irqsave(&udc->lock, flags);
1997 		pullup(udc, 0);
1998 		wake = 0;
1999 		spin_unlock_irqrestore(&udc->lock, flags);
2000 	} else
2001 		enable_irq_wake(udc->udp_irq);
2002 
2003 	udc->active_suspend = wake;
2004 	if (gpio_is_valid(udc->board.vbus_pin) && !udc->board.vbus_polled && wake)
2005 		enable_irq_wake(udc->board.vbus_pin);
2006 	return 0;
2007 }
2008 
2009 static int at91udc_resume(struct platform_device *pdev)
2010 {
2011 	struct at91_udc *udc = platform_get_drvdata(pdev);
2012 	unsigned long	flags;
2013 
2014 	if (gpio_is_valid(udc->board.vbus_pin) && !udc->board.vbus_polled &&
2015 	    udc->active_suspend)
2016 		disable_irq_wake(udc->board.vbus_pin);
2017 
2018 	/* maybe reconnect to host; if so, clocks on */
2019 	if (udc->active_suspend)
2020 		disable_irq_wake(udc->udp_irq);
2021 	else {
2022 		spin_lock_irqsave(&udc->lock, flags);
2023 		pullup(udc, 1);
2024 		spin_unlock_irqrestore(&udc->lock, flags);
2025 	}
2026 	return 0;
2027 }
2028 #else
2029 #define	at91udc_suspend	NULL
2030 #define	at91udc_resume	NULL
2031 #endif
2032 
2033 static struct platform_driver at91_udc_driver = {
2034 	.remove		= at91udc_remove,
2035 	.shutdown	= at91udc_shutdown,
2036 	.suspend	= at91udc_suspend,
2037 	.resume		= at91udc_resume,
2038 	.driver		= {
2039 		.name	= (char *) driver_name,
2040 		.of_match_table	= at91_udc_dt_ids,
2041 	},
2042 };
2043 
2044 module_platform_driver_probe(at91_udc_driver, at91udc_probe);
2045 
2046 MODULE_DESCRIPTION("AT91 udc driver");
2047 MODULE_AUTHOR("Thomas Rathbone, David Brownell");
2048 MODULE_LICENSE("GPL");
2049 MODULE_ALIAS("platform:at91_udc");
2050