xref: /linux/drivers/usb/gadget/udc/at91_udc.c (revision e5c86679d5e864947a52fb31e45a425dea3e7fa9)
1 /*
2  * at91_udc -- driver for at91-series USB peripheral controller
3  *
4  * Copyright (C) 2004 by Thomas Rathbone
5  * Copyright (C) 2005 by HP Labs
6  * Copyright (C) 2005 by David Brownell
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  */
13 
14 #undef	VERBOSE_DEBUG
15 #undef	PACKET_TRACE
16 
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/delay.h>
21 #include <linux/ioport.h>
22 #include <linux/slab.h>
23 #include <linux/errno.h>
24 #include <linux/list.h>
25 #include <linux/interrupt.h>
26 #include <linux/proc_fs.h>
27 #include <linux/prefetch.h>
28 #include <linux/clk.h>
29 #include <linux/usb/ch9.h>
30 #include <linux/usb/gadget.h>
31 #include <linux/of.h>
32 #include <linux/of_gpio.h>
33 #include <linux/platform_data/atmel.h>
34 #include <linux/regmap.h>
35 #include <linux/mfd/syscon.h>
36 #include <linux/mfd/syscon/atmel-matrix.h>
37 
38 #include "at91_udc.h"
39 
40 
41 /*
42  * This controller is simple and PIO-only.  It's used in many AT91-series
43  * full speed USB controllers, including the at91rm9200 (arm920T, with MMU),
44  * at91sam926x (arm926ejs, with MMU), and several no-mmu versions.
45  *
46  * This driver expects the board has been wired with two GPIOs supporting
47  * a VBUS sensing IRQ, and a D+ pullup.  (They may be omitted, but the
48  * testing hasn't covered such cases.)
49  *
50  * The pullup is most important (so it's integrated on sam926x parts).  It
51  * provides software control over whether the host enumerates the device.
52  *
53  * The VBUS sensing helps during enumeration, and allows both USB clocks
54  * (and the transceiver) to stay gated off until they're necessary, saving
55  * power.  During USB suspend, the 48 MHz clock is gated off in hardware;
56  * it may also be gated off by software during some Linux sleep states.
57  */
58 
59 #define	DRIVER_VERSION	"3 May 2006"
60 
61 static const char driver_name [] = "at91_udc";
62 
63 static const struct {
64 	const char *name;
65 	const struct usb_ep_caps caps;
66 } ep_info[] = {
67 #define EP_INFO(_name, _caps) \
68 	{ \
69 		.name = _name, \
70 		.caps = _caps, \
71 	}
72 
73 	EP_INFO("ep0",
74 		USB_EP_CAPS(USB_EP_CAPS_TYPE_CONTROL, USB_EP_CAPS_DIR_ALL)),
75 	EP_INFO("ep1",
76 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
77 	EP_INFO("ep2",
78 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
79 	EP_INFO("ep3-int",
80 		USB_EP_CAPS(USB_EP_CAPS_TYPE_INT, USB_EP_CAPS_DIR_ALL)),
81 	EP_INFO("ep4",
82 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
83 	EP_INFO("ep5",
84 		USB_EP_CAPS(USB_EP_CAPS_TYPE_ALL, USB_EP_CAPS_DIR_ALL)),
85 
86 #undef EP_INFO
87 };
88 
89 #define ep0name		ep_info[0].name
90 
91 #define VBUS_POLL_TIMEOUT	msecs_to_jiffies(1000)
92 
93 #define at91_udp_read(udc, reg) \
94 	__raw_readl((udc)->udp_baseaddr + (reg))
95 #define at91_udp_write(udc, reg, val) \
96 	__raw_writel((val), (udc)->udp_baseaddr + (reg))
97 
98 /*-------------------------------------------------------------------------*/
99 
100 #ifdef CONFIG_USB_GADGET_DEBUG_FILES
101 
102 #include <linux/seq_file.h>
103 
104 static const char debug_filename[] = "driver/udc";
105 
106 #define FOURBITS "%s%s%s%s"
107 #define EIGHTBITS FOURBITS FOURBITS
108 
109 static void proc_ep_show(struct seq_file *s, struct at91_ep *ep)
110 {
111 	static char		*types[] = {
112 		"control", "out-iso", "out-bulk", "out-int",
113 		"BOGUS",   "in-iso",  "in-bulk",  "in-int"};
114 
115 	u32			csr;
116 	struct at91_request	*req;
117 	unsigned long	flags;
118 	struct at91_udc	*udc = ep->udc;
119 
120 	spin_lock_irqsave(&udc->lock, flags);
121 
122 	csr = __raw_readl(ep->creg);
123 
124 	/* NOTE:  not collecting per-endpoint irq statistics... */
125 
126 	seq_printf(s, "\n");
127 	seq_printf(s, "%s, maxpacket %d %s%s %s%s\n",
128 			ep->ep.name, ep->ep.maxpacket,
129 			ep->is_in ? "in" : "out",
130 			ep->is_iso ? " iso" : "",
131 			ep->is_pingpong
132 				? (ep->fifo_bank ? "pong" : "ping")
133 				: "",
134 			ep->stopped ? " stopped" : "");
135 	seq_printf(s, "csr %08x rxbytes=%d %s %s %s" EIGHTBITS "\n",
136 		csr,
137 		(csr & 0x07ff0000) >> 16,
138 		(csr & (1 << 15)) ? "enabled" : "disabled",
139 		(csr & (1 << 11)) ? "DATA1" : "DATA0",
140 		types[(csr & 0x700) >> 8],
141 
142 		/* iff type is control then print current direction */
143 		(!(csr & 0x700))
144 			? ((csr & (1 << 7)) ? " IN" : " OUT")
145 			: "",
146 		(csr & (1 << 6)) ? " rxdatabk1" : "",
147 		(csr & (1 << 5)) ? " forcestall" : "",
148 		(csr & (1 << 4)) ? " txpktrdy" : "",
149 
150 		(csr & (1 << 3)) ? " stallsent" : "",
151 		(csr & (1 << 2)) ? " rxsetup" : "",
152 		(csr & (1 << 1)) ? " rxdatabk0" : "",
153 		(csr & (1 << 0)) ? " txcomp" : "");
154 	if (list_empty (&ep->queue))
155 		seq_printf(s, "\t(queue empty)\n");
156 
157 	else list_for_each_entry (req, &ep->queue, queue) {
158 		unsigned	length = req->req.actual;
159 
160 		seq_printf(s, "\treq %p len %d/%d buf %p\n",
161 				&req->req, length,
162 				req->req.length, req->req.buf);
163 	}
164 	spin_unlock_irqrestore(&udc->lock, flags);
165 }
166 
167 static void proc_irq_show(struct seq_file *s, const char *label, u32 mask)
168 {
169 	int i;
170 
171 	seq_printf(s, "%s %04x:%s%s" FOURBITS, label, mask,
172 		(mask & (1 << 13)) ? " wakeup" : "",
173 		(mask & (1 << 12)) ? " endbusres" : "",
174 
175 		(mask & (1 << 11)) ? " sofint" : "",
176 		(mask & (1 << 10)) ? " extrsm" : "",
177 		(mask & (1 << 9)) ? " rxrsm" : "",
178 		(mask & (1 << 8)) ? " rxsusp" : "");
179 	for (i = 0; i < 8; i++) {
180 		if (mask & (1 << i))
181 			seq_printf(s, " ep%d", i);
182 	}
183 	seq_printf(s, "\n");
184 }
185 
186 static int proc_udc_show(struct seq_file *s, void *unused)
187 {
188 	struct at91_udc	*udc = s->private;
189 	struct at91_ep	*ep;
190 	u32		tmp;
191 
192 	seq_printf(s, "%s: version %s\n", driver_name, DRIVER_VERSION);
193 
194 	seq_printf(s, "vbus %s, pullup %s, %s powered%s, gadget %s\n\n",
195 		udc->vbus ? "present" : "off",
196 		udc->enabled
197 			? (udc->vbus ? "active" : "enabled")
198 			: "disabled",
199 		udc->gadget.is_selfpowered ? "self" : "VBUS",
200 		udc->suspended ? ", suspended" : "",
201 		udc->driver ? udc->driver->driver.name : "(none)");
202 
203 	/* don't access registers when interface isn't clocked */
204 	if (!udc->clocked) {
205 		seq_printf(s, "(not clocked)\n");
206 		return 0;
207 	}
208 
209 	tmp = at91_udp_read(udc, AT91_UDP_FRM_NUM);
210 	seq_printf(s, "frame %05x:%s%s frame=%d\n", tmp,
211 		(tmp & AT91_UDP_FRM_OK) ? " ok" : "",
212 		(tmp & AT91_UDP_FRM_ERR) ? " err" : "",
213 		(tmp & AT91_UDP_NUM));
214 
215 	tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
216 	seq_printf(s, "glbstate %02x:%s" FOURBITS "\n", tmp,
217 		(tmp & AT91_UDP_RMWUPE) ? " rmwupe" : "",
218 		(tmp & AT91_UDP_RSMINPR) ? " rsminpr" : "",
219 		(tmp & AT91_UDP_ESR) ? " esr" : "",
220 		(tmp & AT91_UDP_CONFG) ? " confg" : "",
221 		(tmp & AT91_UDP_FADDEN) ? " fadden" : "");
222 
223 	tmp = at91_udp_read(udc, AT91_UDP_FADDR);
224 	seq_printf(s, "faddr   %03x:%s fadd=%d\n", tmp,
225 		(tmp & AT91_UDP_FEN) ? " fen" : "",
226 		(tmp & AT91_UDP_FADD));
227 
228 	proc_irq_show(s, "imr   ", at91_udp_read(udc, AT91_UDP_IMR));
229 	proc_irq_show(s, "isr   ", at91_udp_read(udc, AT91_UDP_ISR));
230 
231 	if (udc->enabled && udc->vbus) {
232 		proc_ep_show(s, &udc->ep[0]);
233 		list_for_each_entry (ep, &udc->gadget.ep_list, ep.ep_list) {
234 			if (ep->ep.desc)
235 				proc_ep_show(s, ep);
236 		}
237 	}
238 	return 0;
239 }
240 
241 static int proc_udc_open(struct inode *inode, struct file *file)
242 {
243 	return single_open(file, proc_udc_show, PDE_DATA(inode));
244 }
245 
246 static const struct file_operations proc_ops = {
247 	.owner		= THIS_MODULE,
248 	.open		= proc_udc_open,
249 	.read		= seq_read,
250 	.llseek		= seq_lseek,
251 	.release	= single_release,
252 };
253 
254 static void create_debug_file(struct at91_udc *udc)
255 {
256 	udc->pde = proc_create_data(debug_filename, 0, NULL, &proc_ops, udc);
257 }
258 
259 static void remove_debug_file(struct at91_udc *udc)
260 {
261 	if (udc->pde)
262 		remove_proc_entry(debug_filename, NULL);
263 }
264 
265 #else
266 
267 static inline void create_debug_file(struct at91_udc *udc) {}
268 static inline void remove_debug_file(struct at91_udc *udc) {}
269 
270 #endif
271 
272 
273 /*-------------------------------------------------------------------------*/
274 
275 static void done(struct at91_ep *ep, struct at91_request *req, int status)
276 {
277 	unsigned	stopped = ep->stopped;
278 	struct at91_udc	*udc = ep->udc;
279 
280 	list_del_init(&req->queue);
281 	if (req->req.status == -EINPROGRESS)
282 		req->req.status = status;
283 	else
284 		status = req->req.status;
285 	if (status && status != -ESHUTDOWN)
286 		VDBG("%s done %p, status %d\n", ep->ep.name, req, status);
287 
288 	ep->stopped = 1;
289 	spin_unlock(&udc->lock);
290 	usb_gadget_giveback_request(&ep->ep, &req->req);
291 	spin_lock(&udc->lock);
292 	ep->stopped = stopped;
293 
294 	/* ep0 is always ready; other endpoints need a non-empty queue */
295 	if (list_empty(&ep->queue) && ep->int_mask != (1 << 0))
296 		at91_udp_write(udc, AT91_UDP_IDR, ep->int_mask);
297 }
298 
299 /*-------------------------------------------------------------------------*/
300 
301 /* bits indicating OUT fifo has data ready */
302 #define	RX_DATA_READY	(AT91_UDP_RX_DATA_BK0 | AT91_UDP_RX_DATA_BK1)
303 
304 /*
305  * Endpoint FIFO CSR bits have a mix of bits, making it unsafe to just write
306  * back most of the value you just read (because of side effects, including
307  * bits that may change after reading and before writing).
308  *
309  * Except when changing a specific bit, always write values which:
310  *  - clear SET_FX bits (setting them could change something)
311  *  - set CLR_FX bits (clearing them could change something)
312  *
313  * There are also state bits like FORCESTALL, EPEDS, DIR, and EPTYPE
314  * that shouldn't normally be changed.
315  *
316  * NOTE at91sam9260 docs mention synch between UDPCK and MCK clock domains,
317  * implying a need to wait for one write to complete (test relevant bits)
318  * before starting the next write.  This shouldn't be an issue given how
319  * infrequently we write, except maybe for write-then-read idioms.
320  */
321 #define	SET_FX	(AT91_UDP_TXPKTRDY)
322 #define	CLR_FX	(RX_DATA_READY | AT91_UDP_RXSETUP \
323 		| AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)
324 
325 /* pull OUT packet data from the endpoint's fifo */
326 static int read_fifo (struct at91_ep *ep, struct at91_request *req)
327 {
328 	u32 __iomem	*creg = ep->creg;
329 	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
330 	u32		csr;
331 	u8		*buf;
332 	unsigned int	count, bufferspace, is_done;
333 
334 	buf = req->req.buf + req->req.actual;
335 	bufferspace = req->req.length - req->req.actual;
336 
337 	/*
338 	 * there might be nothing to read if ep_queue() calls us,
339 	 * or if we already emptied both pingpong buffers
340 	 */
341 rescan:
342 	csr = __raw_readl(creg);
343 	if ((csr & RX_DATA_READY) == 0)
344 		return 0;
345 
346 	count = (csr & AT91_UDP_RXBYTECNT) >> 16;
347 	if (count > ep->ep.maxpacket)
348 		count = ep->ep.maxpacket;
349 	if (count > bufferspace) {
350 		DBG("%s buffer overflow\n", ep->ep.name);
351 		req->req.status = -EOVERFLOW;
352 		count = bufferspace;
353 	}
354 	__raw_readsb(dreg, buf, count);
355 
356 	/* release and swap pingpong mem bank */
357 	csr |= CLR_FX;
358 	if (ep->is_pingpong) {
359 		if (ep->fifo_bank == 0) {
360 			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
361 			ep->fifo_bank = 1;
362 		} else {
363 			csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK1);
364 			ep->fifo_bank = 0;
365 		}
366 	} else
367 		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
368 	__raw_writel(csr, creg);
369 
370 	req->req.actual += count;
371 	is_done = (count < ep->ep.maxpacket);
372 	if (count == bufferspace)
373 		is_done = 1;
374 
375 	PACKET("%s %p out/%d%s\n", ep->ep.name, &req->req, count,
376 			is_done ? " (done)" : "");
377 
378 	/*
379 	 * avoid extra trips through IRQ logic for packets already in
380 	 * the fifo ... maybe preventing an extra (expensive) OUT-NAK
381 	 */
382 	if (is_done)
383 		done(ep, req, 0);
384 	else if (ep->is_pingpong) {
385 		/*
386 		 * One dummy read to delay the code because of a HW glitch:
387 		 * CSR returns bad RXCOUNT when read too soon after updating
388 		 * RX_DATA_BK flags.
389 		 */
390 		csr = __raw_readl(creg);
391 
392 		bufferspace -= count;
393 		buf += count;
394 		goto rescan;
395 	}
396 
397 	return is_done;
398 }
399 
400 /* load fifo for an IN packet */
401 static int write_fifo(struct at91_ep *ep, struct at91_request *req)
402 {
403 	u32 __iomem	*creg = ep->creg;
404 	u32		csr = __raw_readl(creg);
405 	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
406 	unsigned	total, count, is_last;
407 	u8		*buf;
408 
409 	/*
410 	 * TODO: allow for writing two packets to the fifo ... that'll
411 	 * reduce the amount of IN-NAKing, but probably won't affect
412 	 * throughput much.  (Unlike preventing OUT-NAKing!)
413 	 */
414 
415 	/*
416 	 * If ep_queue() calls us, the queue is empty and possibly in
417 	 * odd states like TXCOMP not yet cleared (we do it, saving at
418 	 * least one IRQ) or the fifo not yet being free.  Those aren't
419 	 * issues normally (IRQ handler fast path).
420 	 */
421 	if (unlikely(csr & (AT91_UDP_TXCOMP | AT91_UDP_TXPKTRDY))) {
422 		if (csr & AT91_UDP_TXCOMP) {
423 			csr |= CLR_FX;
424 			csr &= ~(SET_FX | AT91_UDP_TXCOMP);
425 			__raw_writel(csr, creg);
426 			csr = __raw_readl(creg);
427 		}
428 		if (csr & AT91_UDP_TXPKTRDY)
429 			return 0;
430 	}
431 
432 	buf = req->req.buf + req->req.actual;
433 	prefetch(buf);
434 	total = req->req.length - req->req.actual;
435 	if (ep->ep.maxpacket < total) {
436 		count = ep->ep.maxpacket;
437 		is_last = 0;
438 	} else {
439 		count = total;
440 		is_last = (count < ep->ep.maxpacket) || !req->req.zero;
441 	}
442 
443 	/*
444 	 * Write the packet, maybe it's a ZLP.
445 	 *
446 	 * NOTE:  incrementing req->actual before we receive the ACK means
447 	 * gadget driver IN bytecounts can be wrong in fault cases.  That's
448 	 * fixable with PIO drivers like this one (save "count" here, and
449 	 * do the increment later on TX irq), but not for most DMA hardware.
450 	 *
451 	 * So all gadget drivers must accept that potential error.  Some
452 	 * hardware supports precise fifo status reporting, letting them
453 	 * recover when the actual bytecount matters (e.g. for USB Test
454 	 * and Measurement Class devices).
455 	 */
456 	__raw_writesb(dreg, buf, count);
457 	csr &= ~SET_FX;
458 	csr |= CLR_FX | AT91_UDP_TXPKTRDY;
459 	__raw_writel(csr, creg);
460 	req->req.actual += count;
461 
462 	PACKET("%s %p in/%d%s\n", ep->ep.name, &req->req, count,
463 			is_last ? " (done)" : "");
464 	if (is_last)
465 		done(ep, req, 0);
466 	return is_last;
467 }
468 
469 static void nuke(struct at91_ep *ep, int status)
470 {
471 	struct at91_request *req;
472 
473 	/* terminate any request in the queue */
474 	ep->stopped = 1;
475 	if (list_empty(&ep->queue))
476 		return;
477 
478 	VDBG("%s %s\n", __func__, ep->ep.name);
479 	while (!list_empty(&ep->queue)) {
480 		req = list_entry(ep->queue.next, struct at91_request, queue);
481 		done(ep, req, status);
482 	}
483 }
484 
485 /*-------------------------------------------------------------------------*/
486 
487 static int at91_ep_enable(struct usb_ep *_ep,
488 				const struct usb_endpoint_descriptor *desc)
489 {
490 	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
491 	struct at91_udc *udc;
492 	u16		maxpacket;
493 	u32		tmp;
494 	unsigned long	flags;
495 
496 	if (!_ep || !ep
497 			|| !desc || _ep->name == ep0name
498 			|| desc->bDescriptorType != USB_DT_ENDPOINT
499 			|| (maxpacket = usb_endpoint_maxp(desc)) == 0
500 			|| maxpacket > ep->maxpacket) {
501 		DBG("bad ep or descriptor\n");
502 		return -EINVAL;
503 	}
504 
505 	udc = ep->udc;
506 	if (!udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
507 		DBG("bogus device state\n");
508 		return -ESHUTDOWN;
509 	}
510 
511 	tmp = usb_endpoint_type(desc);
512 	switch (tmp) {
513 	case USB_ENDPOINT_XFER_CONTROL:
514 		DBG("only one control endpoint\n");
515 		return -EINVAL;
516 	case USB_ENDPOINT_XFER_INT:
517 		if (maxpacket > 64)
518 			goto bogus_max;
519 		break;
520 	case USB_ENDPOINT_XFER_BULK:
521 		switch (maxpacket) {
522 		case 8:
523 		case 16:
524 		case 32:
525 		case 64:
526 			goto ok;
527 		}
528 bogus_max:
529 		DBG("bogus maxpacket %d\n", maxpacket);
530 		return -EINVAL;
531 	case USB_ENDPOINT_XFER_ISOC:
532 		if (!ep->is_pingpong) {
533 			DBG("iso requires double buffering\n");
534 			return -EINVAL;
535 		}
536 		break;
537 	}
538 
539 ok:
540 	spin_lock_irqsave(&udc->lock, flags);
541 
542 	/* initialize endpoint to match this descriptor */
543 	ep->is_in = usb_endpoint_dir_in(desc);
544 	ep->is_iso = (tmp == USB_ENDPOINT_XFER_ISOC);
545 	ep->stopped = 0;
546 	if (ep->is_in)
547 		tmp |= 0x04;
548 	tmp <<= 8;
549 	tmp |= AT91_UDP_EPEDS;
550 	__raw_writel(tmp, ep->creg);
551 
552 	ep->ep.maxpacket = maxpacket;
553 
554 	/*
555 	 * reset/init endpoint fifo.  NOTE:  leaves fifo_bank alone,
556 	 * since endpoint resets don't reset hw pingpong state.
557 	 */
558 	at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
559 	at91_udp_write(udc, AT91_UDP_RST_EP, 0);
560 
561 	spin_unlock_irqrestore(&udc->lock, flags);
562 	return 0;
563 }
564 
565 static int at91_ep_disable (struct usb_ep * _ep)
566 {
567 	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
568 	struct at91_udc	*udc = ep->udc;
569 	unsigned long	flags;
570 
571 	if (ep == &ep->udc->ep[0])
572 		return -EINVAL;
573 
574 	spin_lock_irqsave(&udc->lock, flags);
575 
576 	nuke(ep, -ESHUTDOWN);
577 
578 	/* restore the endpoint's pristine config */
579 	ep->ep.desc = NULL;
580 	ep->ep.maxpacket = ep->maxpacket;
581 
582 	/* reset fifos and endpoint */
583 	if (ep->udc->clocked) {
584 		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
585 		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
586 		__raw_writel(0, ep->creg);
587 	}
588 
589 	spin_unlock_irqrestore(&udc->lock, flags);
590 	return 0;
591 }
592 
593 /*
594  * this is a PIO-only driver, so there's nothing
595  * interesting for request or buffer allocation.
596  */
597 
598 static struct usb_request *
599 at91_ep_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
600 {
601 	struct at91_request *req;
602 
603 	req = kzalloc(sizeof (struct at91_request), gfp_flags);
604 	if (!req)
605 		return NULL;
606 
607 	INIT_LIST_HEAD(&req->queue);
608 	return &req->req;
609 }
610 
611 static void at91_ep_free_request(struct usb_ep *_ep, struct usb_request *_req)
612 {
613 	struct at91_request *req;
614 
615 	req = container_of(_req, struct at91_request, req);
616 	BUG_ON(!list_empty(&req->queue));
617 	kfree(req);
618 }
619 
620 static int at91_ep_queue(struct usb_ep *_ep,
621 			struct usb_request *_req, gfp_t gfp_flags)
622 {
623 	struct at91_request	*req;
624 	struct at91_ep		*ep;
625 	struct at91_udc		*udc;
626 	int			status;
627 	unsigned long		flags;
628 
629 	req = container_of(_req, struct at91_request, req);
630 	ep = container_of(_ep, struct at91_ep, ep);
631 
632 	if (!_req || !_req->complete
633 			|| !_req->buf || !list_empty(&req->queue)) {
634 		DBG("invalid request\n");
635 		return -EINVAL;
636 	}
637 
638 	if (!_ep || (!ep->ep.desc && ep->ep.name != ep0name)) {
639 		DBG("invalid ep\n");
640 		return -EINVAL;
641 	}
642 
643 	udc = ep->udc;
644 
645 	if (!udc || !udc->driver || udc->gadget.speed == USB_SPEED_UNKNOWN) {
646 		DBG("invalid device\n");
647 		return -EINVAL;
648 	}
649 
650 	_req->status = -EINPROGRESS;
651 	_req->actual = 0;
652 
653 	spin_lock_irqsave(&udc->lock, flags);
654 
655 	/* try to kickstart any empty and idle queue */
656 	if (list_empty(&ep->queue) && !ep->stopped) {
657 		int	is_ep0;
658 
659 		/*
660 		 * If this control request has a non-empty DATA stage, this
661 		 * will start that stage.  It works just like a non-control
662 		 * request (until the status stage starts, maybe early).
663 		 *
664 		 * If the data stage is empty, then this starts a successful
665 		 * IN/STATUS stage.  (Unsuccessful ones use set_halt.)
666 		 */
667 		is_ep0 = (ep->ep.name == ep0name);
668 		if (is_ep0) {
669 			u32	tmp;
670 
671 			if (!udc->req_pending) {
672 				status = -EINVAL;
673 				goto done;
674 			}
675 
676 			/*
677 			 * defer changing CONFG until after the gadget driver
678 			 * reconfigures the endpoints.
679 			 */
680 			if (udc->wait_for_config_ack) {
681 				tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
682 				tmp ^= AT91_UDP_CONFG;
683 				VDBG("toggle config\n");
684 				at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
685 			}
686 			if (req->req.length == 0) {
687 ep0_in_status:
688 				PACKET("ep0 in/status\n");
689 				status = 0;
690 				tmp = __raw_readl(ep->creg);
691 				tmp &= ~SET_FX;
692 				tmp |= CLR_FX | AT91_UDP_TXPKTRDY;
693 				__raw_writel(tmp, ep->creg);
694 				udc->req_pending = 0;
695 				goto done;
696 			}
697 		}
698 
699 		if (ep->is_in)
700 			status = write_fifo(ep, req);
701 		else {
702 			status = read_fifo(ep, req);
703 
704 			/* IN/STATUS stage is otherwise triggered by irq */
705 			if (status && is_ep0)
706 				goto ep0_in_status;
707 		}
708 	} else
709 		status = 0;
710 
711 	if (req && !status) {
712 		list_add_tail (&req->queue, &ep->queue);
713 		at91_udp_write(udc, AT91_UDP_IER, ep->int_mask);
714 	}
715 done:
716 	spin_unlock_irqrestore(&udc->lock, flags);
717 	return (status < 0) ? status : 0;
718 }
719 
720 static int at91_ep_dequeue(struct usb_ep *_ep, struct usb_request *_req)
721 {
722 	struct at91_ep		*ep;
723 	struct at91_request	*req;
724 	unsigned long		flags;
725 	struct at91_udc		*udc;
726 
727 	ep = container_of(_ep, struct at91_ep, ep);
728 	if (!_ep || ep->ep.name == ep0name)
729 		return -EINVAL;
730 
731 	udc = ep->udc;
732 
733 	spin_lock_irqsave(&udc->lock, flags);
734 
735 	/* make sure it's actually queued on this endpoint */
736 	list_for_each_entry (req, &ep->queue, queue) {
737 		if (&req->req == _req)
738 			break;
739 	}
740 	if (&req->req != _req) {
741 		spin_unlock_irqrestore(&udc->lock, flags);
742 		return -EINVAL;
743 	}
744 
745 	done(ep, req, -ECONNRESET);
746 	spin_unlock_irqrestore(&udc->lock, flags);
747 	return 0;
748 }
749 
750 static int at91_ep_set_halt(struct usb_ep *_ep, int value)
751 {
752 	struct at91_ep	*ep = container_of(_ep, struct at91_ep, ep);
753 	struct at91_udc	*udc = ep->udc;
754 	u32 __iomem	*creg;
755 	u32		csr;
756 	unsigned long	flags;
757 	int		status = 0;
758 
759 	if (!_ep || ep->is_iso || !ep->udc->clocked)
760 		return -EINVAL;
761 
762 	creg = ep->creg;
763 	spin_lock_irqsave(&udc->lock, flags);
764 
765 	csr = __raw_readl(creg);
766 
767 	/*
768 	 * fail with still-busy IN endpoints, ensuring correct sequencing
769 	 * of data tx then stall.  note that the fifo rx bytecount isn't
770 	 * completely accurate as a tx bytecount.
771 	 */
772 	if (ep->is_in && (!list_empty(&ep->queue) || (csr >> 16) != 0))
773 		status = -EAGAIN;
774 	else {
775 		csr |= CLR_FX;
776 		csr &= ~SET_FX;
777 		if (value) {
778 			csr |= AT91_UDP_FORCESTALL;
779 			VDBG("halt %s\n", ep->ep.name);
780 		} else {
781 			at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
782 			at91_udp_write(udc, AT91_UDP_RST_EP, 0);
783 			csr &= ~AT91_UDP_FORCESTALL;
784 		}
785 		__raw_writel(csr, creg);
786 	}
787 
788 	spin_unlock_irqrestore(&udc->lock, flags);
789 	return status;
790 }
791 
792 static const struct usb_ep_ops at91_ep_ops = {
793 	.enable		= at91_ep_enable,
794 	.disable	= at91_ep_disable,
795 	.alloc_request	= at91_ep_alloc_request,
796 	.free_request	= at91_ep_free_request,
797 	.queue		= at91_ep_queue,
798 	.dequeue	= at91_ep_dequeue,
799 	.set_halt	= at91_ep_set_halt,
800 	/* there's only imprecise fifo status reporting */
801 };
802 
803 /*-------------------------------------------------------------------------*/
804 
805 static int at91_get_frame(struct usb_gadget *gadget)
806 {
807 	struct at91_udc *udc = to_udc(gadget);
808 
809 	if (!to_udc(gadget)->clocked)
810 		return -EINVAL;
811 	return at91_udp_read(udc, AT91_UDP_FRM_NUM) & AT91_UDP_NUM;
812 }
813 
814 static int at91_wakeup(struct usb_gadget *gadget)
815 {
816 	struct at91_udc	*udc = to_udc(gadget);
817 	u32		glbstate;
818 	int		status = -EINVAL;
819 	unsigned long	flags;
820 
821 	DBG("%s\n", __func__ );
822 	spin_lock_irqsave(&udc->lock, flags);
823 
824 	if (!udc->clocked || !udc->suspended)
825 		goto done;
826 
827 	/* NOTE:  some "early versions" handle ESR differently ... */
828 
829 	glbstate = at91_udp_read(udc, AT91_UDP_GLB_STAT);
830 	if (!(glbstate & AT91_UDP_ESR))
831 		goto done;
832 	glbstate |= AT91_UDP_ESR;
833 	at91_udp_write(udc, AT91_UDP_GLB_STAT, glbstate);
834 
835 done:
836 	spin_unlock_irqrestore(&udc->lock, flags);
837 	return status;
838 }
839 
840 /* reinit == restore initial software state */
841 static void udc_reinit(struct at91_udc *udc)
842 {
843 	u32 i;
844 
845 	INIT_LIST_HEAD(&udc->gadget.ep_list);
846 	INIT_LIST_HEAD(&udc->gadget.ep0->ep_list);
847 	udc->gadget.quirk_stall_not_supp = 1;
848 
849 	for (i = 0; i < NUM_ENDPOINTS; i++) {
850 		struct at91_ep *ep = &udc->ep[i];
851 
852 		if (i != 0)
853 			list_add_tail(&ep->ep.ep_list, &udc->gadget.ep_list);
854 		ep->ep.desc = NULL;
855 		ep->stopped = 0;
856 		ep->fifo_bank = 0;
857 		usb_ep_set_maxpacket_limit(&ep->ep, ep->maxpacket);
858 		ep->creg = (void __iomem *) udc->udp_baseaddr + AT91_UDP_CSR(i);
859 		/* initialize one queue per endpoint */
860 		INIT_LIST_HEAD(&ep->queue);
861 	}
862 }
863 
864 static void reset_gadget(struct at91_udc *udc)
865 {
866 	struct usb_gadget_driver *driver = udc->driver;
867 	int i;
868 
869 	if (udc->gadget.speed == USB_SPEED_UNKNOWN)
870 		driver = NULL;
871 	udc->gadget.speed = USB_SPEED_UNKNOWN;
872 	udc->suspended = 0;
873 
874 	for (i = 0; i < NUM_ENDPOINTS; i++) {
875 		struct at91_ep *ep = &udc->ep[i];
876 
877 		ep->stopped = 1;
878 		nuke(ep, -ESHUTDOWN);
879 	}
880 	if (driver) {
881 		spin_unlock(&udc->lock);
882 		usb_gadget_udc_reset(&udc->gadget, driver);
883 		spin_lock(&udc->lock);
884 	}
885 
886 	udc_reinit(udc);
887 }
888 
889 static void stop_activity(struct at91_udc *udc)
890 {
891 	struct usb_gadget_driver *driver = udc->driver;
892 	int i;
893 
894 	if (udc->gadget.speed == USB_SPEED_UNKNOWN)
895 		driver = NULL;
896 	udc->gadget.speed = USB_SPEED_UNKNOWN;
897 	udc->suspended = 0;
898 
899 	for (i = 0; i < NUM_ENDPOINTS; i++) {
900 		struct at91_ep *ep = &udc->ep[i];
901 		ep->stopped = 1;
902 		nuke(ep, -ESHUTDOWN);
903 	}
904 	if (driver) {
905 		spin_unlock(&udc->lock);
906 		driver->disconnect(&udc->gadget);
907 		spin_lock(&udc->lock);
908 	}
909 
910 	udc_reinit(udc);
911 }
912 
913 static void clk_on(struct at91_udc *udc)
914 {
915 	if (udc->clocked)
916 		return;
917 	udc->clocked = 1;
918 
919 	clk_enable(udc->iclk);
920 	clk_enable(udc->fclk);
921 }
922 
923 static void clk_off(struct at91_udc *udc)
924 {
925 	if (!udc->clocked)
926 		return;
927 	udc->clocked = 0;
928 	udc->gadget.speed = USB_SPEED_UNKNOWN;
929 	clk_disable(udc->fclk);
930 	clk_disable(udc->iclk);
931 }
932 
933 /*
934  * activate/deactivate link with host; minimize power usage for
935  * inactive links by cutting clocks and transceiver power.
936  */
937 static void pullup(struct at91_udc *udc, int is_on)
938 {
939 	if (!udc->enabled || !udc->vbus)
940 		is_on = 0;
941 	DBG("%sactive\n", is_on ? "" : "in");
942 
943 	if (is_on) {
944 		clk_on(udc);
945 		at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
946 		at91_udp_write(udc, AT91_UDP_TXVC, 0);
947 	} else {
948 		stop_activity(udc);
949 		at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
950 		at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
951 		clk_off(udc);
952 	}
953 
954 	if (udc->caps && udc->caps->pullup)
955 		udc->caps->pullup(udc, is_on);
956 }
957 
958 /* vbus is here!  turn everything on that's ready */
959 static int at91_vbus_session(struct usb_gadget *gadget, int is_active)
960 {
961 	struct at91_udc	*udc = to_udc(gadget);
962 	unsigned long	flags;
963 
964 	/* VDBG("vbus %s\n", is_active ? "on" : "off"); */
965 	spin_lock_irqsave(&udc->lock, flags);
966 	udc->vbus = (is_active != 0);
967 	if (udc->driver)
968 		pullup(udc, is_active);
969 	else
970 		pullup(udc, 0);
971 	spin_unlock_irqrestore(&udc->lock, flags);
972 	return 0;
973 }
974 
975 static int at91_pullup(struct usb_gadget *gadget, int is_on)
976 {
977 	struct at91_udc	*udc = to_udc(gadget);
978 	unsigned long	flags;
979 
980 	spin_lock_irqsave(&udc->lock, flags);
981 	udc->enabled = is_on = !!is_on;
982 	pullup(udc, is_on);
983 	spin_unlock_irqrestore(&udc->lock, flags);
984 	return 0;
985 }
986 
987 static int at91_set_selfpowered(struct usb_gadget *gadget, int is_on)
988 {
989 	struct at91_udc	*udc = to_udc(gadget);
990 	unsigned long	flags;
991 
992 	spin_lock_irqsave(&udc->lock, flags);
993 	gadget->is_selfpowered = (is_on != 0);
994 	spin_unlock_irqrestore(&udc->lock, flags);
995 	return 0;
996 }
997 
998 static int at91_start(struct usb_gadget *gadget,
999 		struct usb_gadget_driver *driver);
1000 static int at91_stop(struct usb_gadget *gadget);
1001 
1002 static const struct usb_gadget_ops at91_udc_ops = {
1003 	.get_frame		= at91_get_frame,
1004 	.wakeup			= at91_wakeup,
1005 	.set_selfpowered	= at91_set_selfpowered,
1006 	.vbus_session		= at91_vbus_session,
1007 	.pullup			= at91_pullup,
1008 	.udc_start		= at91_start,
1009 	.udc_stop		= at91_stop,
1010 
1011 	/*
1012 	 * VBUS-powered devices may also also want to support bigger
1013 	 * power budgets after an appropriate SET_CONFIGURATION.
1014 	 */
1015 	/* .vbus_power		= at91_vbus_power, */
1016 };
1017 
1018 /*-------------------------------------------------------------------------*/
1019 
1020 static int handle_ep(struct at91_ep *ep)
1021 {
1022 	struct at91_request	*req;
1023 	u32 __iomem		*creg = ep->creg;
1024 	u32			csr = __raw_readl(creg);
1025 
1026 	if (!list_empty(&ep->queue))
1027 		req = list_entry(ep->queue.next,
1028 			struct at91_request, queue);
1029 	else
1030 		req = NULL;
1031 
1032 	if (ep->is_in) {
1033 		if (csr & (AT91_UDP_STALLSENT | AT91_UDP_TXCOMP)) {
1034 			csr |= CLR_FX;
1035 			csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_TXCOMP);
1036 			__raw_writel(csr, creg);
1037 		}
1038 		if (req)
1039 			return write_fifo(ep, req);
1040 
1041 	} else {
1042 		if (csr & AT91_UDP_STALLSENT) {
1043 			/* STALLSENT bit == ISOERR */
1044 			if (ep->is_iso && req)
1045 				req->req.status = -EILSEQ;
1046 			csr |= CLR_FX;
1047 			csr &= ~(SET_FX | AT91_UDP_STALLSENT);
1048 			__raw_writel(csr, creg);
1049 			csr = __raw_readl(creg);
1050 		}
1051 		if (req && (csr & RX_DATA_READY))
1052 			return read_fifo(ep, req);
1053 	}
1054 	return 0;
1055 }
1056 
1057 union setup {
1058 	u8			raw[8];
1059 	struct usb_ctrlrequest	r;
1060 };
1061 
1062 static void handle_setup(struct at91_udc *udc, struct at91_ep *ep, u32 csr)
1063 {
1064 	u32 __iomem	*creg = ep->creg;
1065 	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));
1066 	unsigned	rxcount, i = 0;
1067 	u32		tmp;
1068 	union setup	pkt;
1069 	int		status = 0;
1070 
1071 	/* read and ack SETUP; hard-fail for bogus packets */
1072 	rxcount = (csr & AT91_UDP_RXBYTECNT) >> 16;
1073 	if (likely(rxcount == 8)) {
1074 		while (rxcount--)
1075 			pkt.raw[i++] = __raw_readb(dreg);
1076 		if (pkt.r.bRequestType & USB_DIR_IN) {
1077 			csr |= AT91_UDP_DIR;
1078 			ep->is_in = 1;
1079 		} else {
1080 			csr &= ~AT91_UDP_DIR;
1081 			ep->is_in = 0;
1082 		}
1083 	} else {
1084 		/* REVISIT this happens sometimes under load; why?? */
1085 		ERR("SETUP len %d, csr %08x\n", rxcount, csr);
1086 		status = -EINVAL;
1087 	}
1088 	csr |= CLR_FX;
1089 	csr &= ~(SET_FX | AT91_UDP_RXSETUP);
1090 	__raw_writel(csr, creg);
1091 	udc->wait_for_addr_ack = 0;
1092 	udc->wait_for_config_ack = 0;
1093 	ep->stopped = 0;
1094 	if (unlikely(status != 0))
1095 		goto stall;
1096 
1097 #define w_index		le16_to_cpu(pkt.r.wIndex)
1098 #define w_value		le16_to_cpu(pkt.r.wValue)
1099 #define w_length	le16_to_cpu(pkt.r.wLength)
1100 
1101 	VDBG("SETUP %02x.%02x v%04x i%04x l%04x\n",
1102 			pkt.r.bRequestType, pkt.r.bRequest,
1103 			w_value, w_index, w_length);
1104 
1105 	/*
1106 	 * A few standard requests get handled here, ones that touch
1107 	 * hardware ... notably for device and endpoint features.
1108 	 */
1109 	udc->req_pending = 1;
1110 	csr = __raw_readl(creg);
1111 	csr |= CLR_FX;
1112 	csr &= ~SET_FX;
1113 	switch ((pkt.r.bRequestType << 8) | pkt.r.bRequest) {
1114 
1115 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1116 			| USB_REQ_SET_ADDRESS:
1117 		__raw_writel(csr | AT91_UDP_TXPKTRDY, creg);
1118 		udc->addr = w_value;
1119 		udc->wait_for_addr_ack = 1;
1120 		udc->req_pending = 0;
1121 		/* FADDR is set later, when we ack host STATUS */
1122 		return;
1123 
1124 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1125 			| USB_REQ_SET_CONFIGURATION:
1126 		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_CONFG;
1127 		if (pkt.r.wValue)
1128 			udc->wait_for_config_ack = (tmp == 0);
1129 		else
1130 			udc->wait_for_config_ack = (tmp != 0);
1131 		if (udc->wait_for_config_ack)
1132 			VDBG("wait for config\n");
1133 		/* CONFG is toggled later, if gadget driver succeeds */
1134 		break;
1135 
1136 	/*
1137 	 * Hosts may set or clear remote wakeup status, and
1138 	 * devices may report they're VBUS powered.
1139 	 */
1140 	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1141 			| USB_REQ_GET_STATUS:
1142 		tmp = (udc->gadget.is_selfpowered << USB_DEVICE_SELF_POWERED);
1143 		if (at91_udp_read(udc, AT91_UDP_GLB_STAT) & AT91_UDP_ESR)
1144 			tmp |= (1 << USB_DEVICE_REMOTE_WAKEUP);
1145 		PACKET("get device status\n");
1146 		__raw_writeb(tmp, dreg);
1147 		__raw_writeb(0, dreg);
1148 		goto write_in;
1149 		/* then STATUS starts later, automatically */
1150 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1151 			| USB_REQ_SET_FEATURE:
1152 		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
1153 			goto stall;
1154 		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
1155 		tmp |= AT91_UDP_ESR;
1156 		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
1157 		goto succeed;
1158 	case ((USB_TYPE_STANDARD|USB_RECIP_DEVICE) << 8)
1159 			| USB_REQ_CLEAR_FEATURE:
1160 		if (w_value != USB_DEVICE_REMOTE_WAKEUP)
1161 			goto stall;
1162 		tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
1163 		tmp &= ~AT91_UDP_ESR;
1164 		at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
1165 		goto succeed;
1166 
1167 	/*
1168 	 * Interfaces have no feature settings; this is pretty useless.
1169 	 * we won't even insist the interface exists...
1170 	 */
1171 	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
1172 			| USB_REQ_GET_STATUS:
1173 		PACKET("get interface status\n");
1174 		__raw_writeb(0, dreg);
1175 		__raw_writeb(0, dreg);
1176 		goto write_in;
1177 		/* then STATUS starts later, automatically */
1178 	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
1179 			| USB_REQ_SET_FEATURE:
1180 	case ((USB_TYPE_STANDARD|USB_RECIP_INTERFACE) << 8)
1181 			| USB_REQ_CLEAR_FEATURE:
1182 		goto stall;
1183 
1184 	/*
1185 	 * Hosts may clear bulk/intr endpoint halt after the gadget
1186 	 * driver sets it (not widely used); or set it (for testing)
1187 	 */
1188 	case ((USB_DIR_IN|USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
1189 			| USB_REQ_GET_STATUS:
1190 		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
1191 		ep = &udc->ep[tmp];
1192 		if (tmp >= NUM_ENDPOINTS || (tmp && !ep->ep.desc))
1193 			goto stall;
1194 
1195 		if (tmp) {
1196 			if ((w_index & USB_DIR_IN)) {
1197 				if (!ep->is_in)
1198 					goto stall;
1199 			} else if (ep->is_in)
1200 				goto stall;
1201 		}
1202 		PACKET("get %s status\n", ep->ep.name);
1203 		if (__raw_readl(ep->creg) & AT91_UDP_FORCESTALL)
1204 			tmp = (1 << USB_ENDPOINT_HALT);
1205 		else
1206 			tmp = 0;
1207 		__raw_writeb(tmp, dreg);
1208 		__raw_writeb(0, dreg);
1209 		goto write_in;
1210 		/* then STATUS starts later, automatically */
1211 	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
1212 			| USB_REQ_SET_FEATURE:
1213 		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
1214 		ep = &udc->ep[tmp];
1215 		if (w_value != USB_ENDPOINT_HALT || tmp >= NUM_ENDPOINTS)
1216 			goto stall;
1217 		if (!ep->ep.desc || ep->is_iso)
1218 			goto stall;
1219 		if ((w_index & USB_DIR_IN)) {
1220 			if (!ep->is_in)
1221 				goto stall;
1222 		} else if (ep->is_in)
1223 			goto stall;
1224 
1225 		tmp = __raw_readl(ep->creg);
1226 		tmp &= ~SET_FX;
1227 		tmp |= CLR_FX | AT91_UDP_FORCESTALL;
1228 		__raw_writel(tmp, ep->creg);
1229 		goto succeed;
1230 	case ((USB_TYPE_STANDARD|USB_RECIP_ENDPOINT) << 8)
1231 			| USB_REQ_CLEAR_FEATURE:
1232 		tmp = w_index & USB_ENDPOINT_NUMBER_MASK;
1233 		ep = &udc->ep[tmp];
1234 		if (w_value != USB_ENDPOINT_HALT || tmp >= NUM_ENDPOINTS)
1235 			goto stall;
1236 		if (tmp == 0)
1237 			goto succeed;
1238 		if (!ep->ep.desc || ep->is_iso)
1239 			goto stall;
1240 		if ((w_index & USB_DIR_IN)) {
1241 			if (!ep->is_in)
1242 				goto stall;
1243 		} else if (ep->is_in)
1244 			goto stall;
1245 
1246 		at91_udp_write(udc, AT91_UDP_RST_EP, ep->int_mask);
1247 		at91_udp_write(udc, AT91_UDP_RST_EP, 0);
1248 		tmp = __raw_readl(ep->creg);
1249 		tmp |= CLR_FX;
1250 		tmp &= ~(SET_FX | AT91_UDP_FORCESTALL);
1251 		__raw_writel(tmp, ep->creg);
1252 		if (!list_empty(&ep->queue))
1253 			handle_ep(ep);
1254 		goto succeed;
1255 	}
1256 
1257 #undef w_value
1258 #undef w_index
1259 #undef w_length
1260 
1261 	/* pass request up to the gadget driver */
1262 	if (udc->driver) {
1263 		spin_unlock(&udc->lock);
1264 		status = udc->driver->setup(&udc->gadget, &pkt.r);
1265 		spin_lock(&udc->lock);
1266 	}
1267 	else
1268 		status = -ENODEV;
1269 	if (status < 0) {
1270 stall:
1271 		VDBG("req %02x.%02x protocol STALL; stat %d\n",
1272 				pkt.r.bRequestType, pkt.r.bRequest, status);
1273 		csr |= AT91_UDP_FORCESTALL;
1274 		__raw_writel(csr, creg);
1275 		udc->req_pending = 0;
1276 	}
1277 	return;
1278 
1279 succeed:
1280 	/* immediate successful (IN) STATUS after zero length DATA */
1281 	PACKET("ep0 in/status\n");
1282 write_in:
1283 	csr |= AT91_UDP_TXPKTRDY;
1284 	__raw_writel(csr, creg);
1285 	udc->req_pending = 0;
1286 }
1287 
1288 static void handle_ep0(struct at91_udc *udc)
1289 {
1290 	struct at91_ep		*ep0 = &udc->ep[0];
1291 	u32 __iomem		*creg = ep0->creg;
1292 	u32			csr = __raw_readl(creg);
1293 	struct at91_request	*req;
1294 
1295 	if (unlikely(csr & AT91_UDP_STALLSENT)) {
1296 		nuke(ep0, -EPROTO);
1297 		udc->req_pending = 0;
1298 		csr |= CLR_FX;
1299 		csr &= ~(SET_FX | AT91_UDP_STALLSENT | AT91_UDP_FORCESTALL);
1300 		__raw_writel(csr, creg);
1301 		VDBG("ep0 stalled\n");
1302 		csr = __raw_readl(creg);
1303 	}
1304 	if (csr & AT91_UDP_RXSETUP) {
1305 		nuke(ep0, 0);
1306 		udc->req_pending = 0;
1307 		handle_setup(udc, ep0, csr);
1308 		return;
1309 	}
1310 
1311 	if (list_empty(&ep0->queue))
1312 		req = NULL;
1313 	else
1314 		req = list_entry(ep0->queue.next, struct at91_request, queue);
1315 
1316 	/* host ACKed an IN packet that we sent */
1317 	if (csr & AT91_UDP_TXCOMP) {
1318 		csr |= CLR_FX;
1319 		csr &= ~(SET_FX | AT91_UDP_TXCOMP);
1320 
1321 		/* write more IN DATA? */
1322 		if (req && ep0->is_in) {
1323 			if (handle_ep(ep0))
1324 				udc->req_pending = 0;
1325 
1326 		/*
1327 		 * Ack after:
1328 		 *  - last IN DATA packet (including GET_STATUS)
1329 		 *  - IN/STATUS for OUT DATA
1330 		 *  - IN/STATUS for any zero-length DATA stage
1331 		 * except for the IN DATA case, the host should send
1332 		 * an OUT status later, which we'll ack.
1333 		 */
1334 		} else {
1335 			udc->req_pending = 0;
1336 			__raw_writel(csr, creg);
1337 
1338 			/*
1339 			 * SET_ADDRESS takes effect only after the STATUS
1340 			 * (to the original address) gets acked.
1341 			 */
1342 			if (udc->wait_for_addr_ack) {
1343 				u32	tmp;
1344 
1345 				at91_udp_write(udc, AT91_UDP_FADDR,
1346 						AT91_UDP_FEN | udc->addr);
1347 				tmp = at91_udp_read(udc, AT91_UDP_GLB_STAT);
1348 				tmp &= ~AT91_UDP_FADDEN;
1349 				if (udc->addr)
1350 					tmp |= AT91_UDP_FADDEN;
1351 				at91_udp_write(udc, AT91_UDP_GLB_STAT, tmp);
1352 
1353 				udc->wait_for_addr_ack = 0;
1354 				VDBG("address %d\n", udc->addr);
1355 			}
1356 		}
1357 	}
1358 
1359 	/* OUT packet arrived ... */
1360 	else if (csr & AT91_UDP_RX_DATA_BK0) {
1361 		csr |= CLR_FX;
1362 		csr &= ~(SET_FX | AT91_UDP_RX_DATA_BK0);
1363 
1364 		/* OUT DATA stage */
1365 		if (!ep0->is_in) {
1366 			if (req) {
1367 				if (handle_ep(ep0)) {
1368 					/* send IN/STATUS */
1369 					PACKET("ep0 in/status\n");
1370 					csr = __raw_readl(creg);
1371 					csr &= ~SET_FX;
1372 					csr |= CLR_FX | AT91_UDP_TXPKTRDY;
1373 					__raw_writel(csr, creg);
1374 					udc->req_pending = 0;
1375 				}
1376 			} else if (udc->req_pending) {
1377 				/*
1378 				 * AT91 hardware has a hard time with this
1379 				 * "deferred response" mode for control-OUT
1380 				 * transfers.  (For control-IN it's fine.)
1381 				 *
1382 				 * The normal solution leaves OUT data in the
1383 				 * fifo until the gadget driver is ready.
1384 				 * We couldn't do that here without disabling
1385 				 * the IRQ that tells about SETUP packets,
1386 				 * e.g. when the host gets impatient...
1387 				 *
1388 				 * Working around it by copying into a buffer
1389 				 * would almost be a non-deferred response,
1390 				 * except that it wouldn't permit reliable
1391 				 * stalling of the request.  Instead, demand
1392 				 * that gadget drivers not use this mode.
1393 				 */
1394 				DBG("no control-OUT deferred responses!\n");
1395 				__raw_writel(csr | AT91_UDP_FORCESTALL, creg);
1396 				udc->req_pending = 0;
1397 			}
1398 
1399 		/* STATUS stage for control-IN; ack.  */
1400 		} else {
1401 			PACKET("ep0 out/status ACK\n");
1402 			__raw_writel(csr, creg);
1403 
1404 			/* "early" status stage */
1405 			if (req)
1406 				done(ep0, req, 0);
1407 		}
1408 	}
1409 }
1410 
1411 static irqreturn_t at91_udc_irq (int irq, void *_udc)
1412 {
1413 	struct at91_udc		*udc = _udc;
1414 	u32			rescans = 5;
1415 	int			disable_clock = 0;
1416 	unsigned long		flags;
1417 
1418 	spin_lock_irqsave(&udc->lock, flags);
1419 
1420 	if (!udc->clocked) {
1421 		clk_on(udc);
1422 		disable_clock = 1;
1423 	}
1424 
1425 	while (rescans--) {
1426 		u32 status;
1427 
1428 		status = at91_udp_read(udc, AT91_UDP_ISR)
1429 			& at91_udp_read(udc, AT91_UDP_IMR);
1430 		if (!status)
1431 			break;
1432 
1433 		/* USB reset irq:  not maskable */
1434 		if (status & AT91_UDP_ENDBUSRES) {
1435 			at91_udp_write(udc, AT91_UDP_IDR, ~MINIMUS_INTERRUPTUS);
1436 			at91_udp_write(udc, AT91_UDP_IER, MINIMUS_INTERRUPTUS);
1437 			/* Atmel code clears this irq twice */
1438 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
1439 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_ENDBUSRES);
1440 			VDBG("end bus reset\n");
1441 			udc->addr = 0;
1442 			reset_gadget(udc);
1443 
1444 			/* enable ep0 */
1445 			at91_udp_write(udc, AT91_UDP_CSR(0),
1446 					AT91_UDP_EPEDS | AT91_UDP_EPTYPE_CTRL);
1447 			udc->gadget.speed = USB_SPEED_FULL;
1448 			udc->suspended = 0;
1449 			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_EP(0));
1450 
1451 			/*
1452 			 * NOTE:  this driver keeps clocks off unless the
1453 			 * USB host is present.  That saves power, but for
1454 			 * boards that don't support VBUS detection, both
1455 			 * clocks need to be active most of the time.
1456 			 */
1457 
1458 		/* host initiated suspend (3+ms bus idle) */
1459 		} else if (status & AT91_UDP_RXSUSP) {
1460 			at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXSUSP);
1461 			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXRSM);
1462 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXSUSP);
1463 			/* VDBG("bus suspend\n"); */
1464 			if (udc->suspended)
1465 				continue;
1466 			udc->suspended = 1;
1467 
1468 			/*
1469 			 * NOTE:  when suspending a VBUS-powered device, the
1470 			 * gadget driver should switch into slow clock mode
1471 			 * and then into standby to avoid drawing more than
1472 			 * 500uA power (2500uA for some high-power configs).
1473 			 */
1474 			if (udc->driver && udc->driver->suspend) {
1475 				spin_unlock(&udc->lock);
1476 				udc->driver->suspend(&udc->gadget);
1477 				spin_lock(&udc->lock);
1478 			}
1479 
1480 		/* host initiated resume */
1481 		} else if (status & AT91_UDP_RXRSM) {
1482 			at91_udp_write(udc, AT91_UDP_IDR, AT91_UDP_RXRSM);
1483 			at91_udp_write(udc, AT91_UDP_IER, AT91_UDP_RXSUSP);
1484 			at91_udp_write(udc, AT91_UDP_ICR, AT91_UDP_RXRSM);
1485 			/* VDBG("bus resume\n"); */
1486 			if (!udc->suspended)
1487 				continue;
1488 			udc->suspended = 0;
1489 
1490 			/*
1491 			 * NOTE:  for a VBUS-powered device, the gadget driver
1492 			 * would normally want to switch out of slow clock
1493 			 * mode into normal mode.
1494 			 */
1495 			if (udc->driver && udc->driver->resume) {
1496 				spin_unlock(&udc->lock);
1497 				udc->driver->resume(&udc->gadget);
1498 				spin_lock(&udc->lock);
1499 			}
1500 
1501 		/* endpoint IRQs are cleared by handling them */
1502 		} else {
1503 			int		i;
1504 			unsigned	mask = 1;
1505 			struct at91_ep	*ep = &udc->ep[1];
1506 
1507 			if (status & mask)
1508 				handle_ep0(udc);
1509 			for (i = 1; i < NUM_ENDPOINTS; i++) {
1510 				mask <<= 1;
1511 				if (status & mask)
1512 					handle_ep(ep);
1513 				ep++;
1514 			}
1515 		}
1516 	}
1517 
1518 	if (disable_clock)
1519 		clk_off(udc);
1520 
1521 	spin_unlock_irqrestore(&udc->lock, flags);
1522 
1523 	return IRQ_HANDLED;
1524 }
1525 
1526 /*-------------------------------------------------------------------------*/
1527 
1528 static void at91_vbus_update(struct at91_udc *udc, unsigned value)
1529 {
1530 	value ^= udc->board.vbus_active_low;
1531 	if (value != udc->vbus)
1532 		at91_vbus_session(&udc->gadget, value);
1533 }
1534 
1535 static irqreturn_t at91_vbus_irq(int irq, void *_udc)
1536 {
1537 	struct at91_udc	*udc = _udc;
1538 
1539 	/* vbus needs at least brief debouncing */
1540 	udelay(10);
1541 	at91_vbus_update(udc, gpio_get_value(udc->board.vbus_pin));
1542 
1543 	return IRQ_HANDLED;
1544 }
1545 
1546 static void at91_vbus_timer_work(struct work_struct *work)
1547 {
1548 	struct at91_udc *udc = container_of(work, struct at91_udc,
1549 					    vbus_timer_work);
1550 
1551 	at91_vbus_update(udc, gpio_get_value_cansleep(udc->board.vbus_pin));
1552 
1553 	if (!timer_pending(&udc->vbus_timer))
1554 		mod_timer(&udc->vbus_timer, jiffies + VBUS_POLL_TIMEOUT);
1555 }
1556 
1557 static void at91_vbus_timer(unsigned long data)
1558 {
1559 	struct at91_udc *udc = (struct at91_udc *)data;
1560 
1561 	/*
1562 	 * If we are polling vbus it is likely that the gpio is on an
1563 	 * bus such as i2c or spi which may sleep, so schedule some work
1564 	 * to read the vbus gpio
1565 	 */
1566 	schedule_work(&udc->vbus_timer_work);
1567 }
1568 
1569 static int at91_start(struct usb_gadget *gadget,
1570 		struct usb_gadget_driver *driver)
1571 {
1572 	struct at91_udc	*udc;
1573 
1574 	udc = container_of(gadget, struct at91_udc, gadget);
1575 	udc->driver = driver;
1576 	udc->gadget.dev.of_node = udc->pdev->dev.of_node;
1577 	udc->enabled = 1;
1578 	udc->gadget.is_selfpowered = 1;
1579 
1580 	return 0;
1581 }
1582 
1583 static int at91_stop(struct usb_gadget *gadget)
1584 {
1585 	struct at91_udc *udc;
1586 	unsigned long	flags;
1587 
1588 	udc = container_of(gadget, struct at91_udc, gadget);
1589 	spin_lock_irqsave(&udc->lock, flags);
1590 	udc->enabled = 0;
1591 	at91_udp_write(udc, AT91_UDP_IDR, ~0);
1592 	spin_unlock_irqrestore(&udc->lock, flags);
1593 
1594 	udc->driver = NULL;
1595 
1596 	return 0;
1597 }
1598 
1599 /*-------------------------------------------------------------------------*/
1600 
1601 static void at91udc_shutdown(struct platform_device *dev)
1602 {
1603 	struct at91_udc *udc = platform_get_drvdata(dev);
1604 	unsigned long	flags;
1605 
1606 	/* force disconnect on reboot */
1607 	spin_lock_irqsave(&udc->lock, flags);
1608 	pullup(platform_get_drvdata(dev), 0);
1609 	spin_unlock_irqrestore(&udc->lock, flags);
1610 }
1611 
1612 static int at91rm9200_udc_init(struct at91_udc *udc)
1613 {
1614 	struct at91_ep *ep;
1615 	int ret;
1616 	int i;
1617 
1618 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1619 		ep = &udc->ep[i];
1620 
1621 		switch (i) {
1622 		case 0:
1623 		case 3:
1624 			ep->maxpacket = 8;
1625 			break;
1626 		case 1 ... 2:
1627 			ep->maxpacket = 64;
1628 			break;
1629 		case 4 ... 5:
1630 			ep->maxpacket = 256;
1631 			break;
1632 		}
1633 	}
1634 
1635 	if (!gpio_is_valid(udc->board.pullup_pin)) {
1636 		DBG("no D+ pullup?\n");
1637 		return -ENODEV;
1638 	}
1639 
1640 	ret = devm_gpio_request(&udc->pdev->dev, udc->board.pullup_pin,
1641 				"udc_pullup");
1642 	if (ret) {
1643 		DBG("D+ pullup is busy\n");
1644 		return ret;
1645 	}
1646 
1647 	gpio_direction_output(udc->board.pullup_pin,
1648 			      udc->board.pullup_active_low);
1649 
1650 	return 0;
1651 }
1652 
1653 static void at91rm9200_udc_pullup(struct at91_udc *udc, int is_on)
1654 {
1655 	int active = !udc->board.pullup_active_low;
1656 
1657 	if (is_on)
1658 		gpio_set_value(udc->board.pullup_pin, active);
1659 	else
1660 		gpio_set_value(udc->board.pullup_pin, !active);
1661 }
1662 
1663 static const struct at91_udc_caps at91rm9200_udc_caps = {
1664 	.init = at91rm9200_udc_init,
1665 	.pullup = at91rm9200_udc_pullup,
1666 };
1667 
1668 static int at91sam9260_udc_init(struct at91_udc *udc)
1669 {
1670 	struct at91_ep *ep;
1671 	int i;
1672 
1673 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1674 		ep = &udc->ep[i];
1675 
1676 		switch (i) {
1677 		case 0 ... 3:
1678 			ep->maxpacket = 64;
1679 			break;
1680 		case 4 ... 5:
1681 			ep->maxpacket = 512;
1682 			break;
1683 		}
1684 	}
1685 
1686 	return 0;
1687 }
1688 
1689 static void at91sam9260_udc_pullup(struct at91_udc *udc, int is_on)
1690 {
1691 	u32 txvc = at91_udp_read(udc, AT91_UDP_TXVC);
1692 
1693 	if (is_on)
1694 		txvc |= AT91_UDP_TXVC_PUON;
1695 	else
1696 		txvc &= ~AT91_UDP_TXVC_PUON;
1697 
1698 	at91_udp_write(udc, AT91_UDP_TXVC, txvc);
1699 }
1700 
1701 static const struct at91_udc_caps at91sam9260_udc_caps = {
1702 	.init = at91sam9260_udc_init,
1703 	.pullup = at91sam9260_udc_pullup,
1704 };
1705 
1706 static int at91sam9261_udc_init(struct at91_udc *udc)
1707 {
1708 	struct at91_ep *ep;
1709 	int i;
1710 
1711 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1712 		ep = &udc->ep[i];
1713 
1714 		switch (i) {
1715 		case 0:
1716 			ep->maxpacket = 8;
1717 			break;
1718 		case 1 ... 3:
1719 			ep->maxpacket = 64;
1720 			break;
1721 		case 4 ... 5:
1722 			ep->maxpacket = 256;
1723 			break;
1724 		}
1725 	}
1726 
1727 	udc->matrix = syscon_regmap_lookup_by_phandle(udc->pdev->dev.of_node,
1728 						      "atmel,matrix");
1729 	return PTR_ERR_OR_ZERO(udc->matrix);
1730 }
1731 
1732 static void at91sam9261_udc_pullup(struct at91_udc *udc, int is_on)
1733 {
1734 	u32 usbpucr = 0;
1735 
1736 	if (is_on)
1737 		usbpucr = AT91_MATRIX_USBPUCR_PUON;
1738 
1739 	regmap_update_bits(udc->matrix, AT91SAM9261_MATRIX_USBPUCR,
1740 			   AT91_MATRIX_USBPUCR_PUON, usbpucr);
1741 }
1742 
1743 static const struct at91_udc_caps at91sam9261_udc_caps = {
1744 	.init = at91sam9261_udc_init,
1745 	.pullup = at91sam9261_udc_pullup,
1746 };
1747 
1748 static int at91sam9263_udc_init(struct at91_udc *udc)
1749 {
1750 	struct at91_ep *ep;
1751 	int i;
1752 
1753 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1754 		ep = &udc->ep[i];
1755 
1756 		switch (i) {
1757 		case 0:
1758 		case 1:
1759 		case 2:
1760 		case 3:
1761 			ep->maxpacket = 64;
1762 			break;
1763 		case 4:
1764 		case 5:
1765 			ep->maxpacket = 256;
1766 			break;
1767 		}
1768 	}
1769 
1770 	return 0;
1771 }
1772 
1773 static const struct at91_udc_caps at91sam9263_udc_caps = {
1774 	.init = at91sam9263_udc_init,
1775 	.pullup = at91sam9260_udc_pullup,
1776 };
1777 
1778 static const struct of_device_id at91_udc_dt_ids[] = {
1779 	{
1780 		.compatible = "atmel,at91rm9200-udc",
1781 		.data = &at91rm9200_udc_caps,
1782 	},
1783 	{
1784 		.compatible = "atmel,at91sam9260-udc",
1785 		.data = &at91sam9260_udc_caps,
1786 	},
1787 	{
1788 		.compatible = "atmel,at91sam9261-udc",
1789 		.data = &at91sam9261_udc_caps,
1790 	},
1791 	{
1792 		.compatible = "atmel,at91sam9263-udc",
1793 		.data = &at91sam9263_udc_caps,
1794 	},
1795 	{ /* sentinel */ }
1796 };
1797 MODULE_DEVICE_TABLE(of, at91_udc_dt_ids);
1798 
1799 static void at91udc_of_init(struct at91_udc *udc, struct device_node *np)
1800 {
1801 	struct at91_udc_data *board = &udc->board;
1802 	const struct of_device_id *match;
1803 	enum of_gpio_flags flags;
1804 	u32 val;
1805 
1806 	if (of_property_read_u32(np, "atmel,vbus-polled", &val) == 0)
1807 		board->vbus_polled = 1;
1808 
1809 	board->vbus_pin = of_get_named_gpio_flags(np, "atmel,vbus-gpio", 0,
1810 						  &flags);
1811 	board->vbus_active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
1812 
1813 	board->pullup_pin = of_get_named_gpio_flags(np, "atmel,pullup-gpio", 0,
1814 						  &flags);
1815 
1816 	board->pullup_active_low = (flags & OF_GPIO_ACTIVE_LOW) ? 1 : 0;
1817 
1818 	match = of_match_node(at91_udc_dt_ids, np);
1819 	if (match)
1820 		udc->caps = match->data;
1821 }
1822 
1823 static int at91udc_probe(struct platform_device *pdev)
1824 {
1825 	struct device	*dev = &pdev->dev;
1826 	struct at91_udc	*udc;
1827 	int		retval;
1828 	struct resource	*res;
1829 	struct at91_ep	*ep;
1830 	int		i;
1831 
1832 	udc = devm_kzalloc(dev, sizeof(*udc), GFP_KERNEL);
1833 	if (!udc)
1834 		return -ENOMEM;
1835 
1836 	/* init software state */
1837 	udc->gadget.dev.parent = dev;
1838 	at91udc_of_init(udc, pdev->dev.of_node);
1839 	udc->pdev = pdev;
1840 	udc->enabled = 0;
1841 	spin_lock_init(&udc->lock);
1842 
1843 	udc->gadget.ops = &at91_udc_ops;
1844 	udc->gadget.ep0 = &udc->ep[0].ep;
1845 	udc->gadget.name = driver_name;
1846 	udc->gadget.dev.init_name = "gadget";
1847 
1848 	for (i = 0; i < NUM_ENDPOINTS; i++) {
1849 		ep = &udc->ep[i];
1850 		ep->ep.name = ep_info[i].name;
1851 		ep->ep.caps = ep_info[i].caps;
1852 		ep->ep.ops = &at91_ep_ops;
1853 		ep->udc = udc;
1854 		ep->int_mask = BIT(i);
1855 		if (i != 0 && i != 3)
1856 			ep->is_pingpong = 1;
1857 	}
1858 
1859 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1860 	udc->udp_baseaddr = devm_ioremap_resource(dev, res);
1861 	if (IS_ERR(udc->udp_baseaddr))
1862 		return PTR_ERR(udc->udp_baseaddr);
1863 
1864 	if (udc->caps && udc->caps->init) {
1865 		retval = udc->caps->init(udc);
1866 		if (retval)
1867 			return retval;
1868 	}
1869 
1870 	udc_reinit(udc);
1871 
1872 	/* get interface and function clocks */
1873 	udc->iclk = devm_clk_get(dev, "pclk");
1874 	if (IS_ERR(udc->iclk))
1875 		return PTR_ERR(udc->iclk);
1876 
1877 	udc->fclk = devm_clk_get(dev, "hclk");
1878 	if (IS_ERR(udc->fclk))
1879 		return PTR_ERR(udc->fclk);
1880 
1881 	/* don't do anything until we have both gadget driver and VBUS */
1882 	clk_set_rate(udc->fclk, 48000000);
1883 	retval = clk_prepare(udc->fclk);
1884 	if (retval)
1885 		return retval;
1886 
1887 	retval = clk_prepare_enable(udc->iclk);
1888 	if (retval)
1889 		goto err_unprepare_fclk;
1890 
1891 	at91_udp_write(udc, AT91_UDP_TXVC, AT91_UDP_TXVC_TXVDIS);
1892 	at91_udp_write(udc, AT91_UDP_IDR, 0xffffffff);
1893 	/* Clear all pending interrupts - UDP may be used by bootloader. */
1894 	at91_udp_write(udc, AT91_UDP_ICR, 0xffffffff);
1895 	clk_disable(udc->iclk);
1896 
1897 	/* request UDC and maybe VBUS irqs */
1898 	udc->udp_irq = platform_get_irq(pdev, 0);
1899 	retval = devm_request_irq(dev, udc->udp_irq, at91_udc_irq, 0,
1900 				  driver_name, udc);
1901 	if (retval) {
1902 		DBG("request irq %d failed\n", udc->udp_irq);
1903 		goto err_unprepare_iclk;
1904 	}
1905 
1906 	if (gpio_is_valid(udc->board.vbus_pin)) {
1907 		retval = devm_gpio_request(dev, udc->board.vbus_pin,
1908 					   "udc_vbus");
1909 		if (retval) {
1910 			DBG("request vbus pin failed\n");
1911 			goto err_unprepare_iclk;
1912 		}
1913 
1914 		gpio_direction_input(udc->board.vbus_pin);
1915 
1916 		/*
1917 		 * Get the initial state of VBUS - we cannot expect
1918 		 * a pending interrupt.
1919 		 */
1920 		udc->vbus = gpio_get_value_cansleep(udc->board.vbus_pin) ^
1921 			udc->board.vbus_active_low;
1922 
1923 		if (udc->board.vbus_polled) {
1924 			INIT_WORK(&udc->vbus_timer_work, at91_vbus_timer_work);
1925 			setup_timer(&udc->vbus_timer, at91_vbus_timer,
1926 				    (unsigned long)udc);
1927 			mod_timer(&udc->vbus_timer,
1928 				  jiffies + VBUS_POLL_TIMEOUT);
1929 		} else {
1930 			retval = devm_request_irq(dev,
1931 					gpio_to_irq(udc->board.vbus_pin),
1932 					at91_vbus_irq, 0, driver_name, udc);
1933 			if (retval) {
1934 				DBG("request vbus irq %d failed\n",
1935 				    udc->board.vbus_pin);
1936 				goto err_unprepare_iclk;
1937 			}
1938 		}
1939 	} else {
1940 		DBG("no VBUS detection, assuming always-on\n");
1941 		udc->vbus = 1;
1942 	}
1943 	retval = usb_add_gadget_udc(dev, &udc->gadget);
1944 	if (retval)
1945 		goto err_unprepare_iclk;
1946 	dev_set_drvdata(dev, udc);
1947 	device_init_wakeup(dev, 1);
1948 	create_debug_file(udc);
1949 
1950 	INFO("%s version %s\n", driver_name, DRIVER_VERSION);
1951 	return 0;
1952 
1953 err_unprepare_iclk:
1954 	clk_unprepare(udc->iclk);
1955 err_unprepare_fclk:
1956 	clk_unprepare(udc->fclk);
1957 
1958 	DBG("%s probe failed, %d\n", driver_name, retval);
1959 
1960 	return retval;
1961 }
1962 
1963 static int at91udc_remove(struct platform_device *pdev)
1964 {
1965 	struct at91_udc *udc = platform_get_drvdata(pdev);
1966 	unsigned long	flags;
1967 
1968 	DBG("remove\n");
1969 
1970 	usb_del_gadget_udc(&udc->gadget);
1971 	if (udc->driver)
1972 		return -EBUSY;
1973 
1974 	spin_lock_irqsave(&udc->lock, flags);
1975 	pullup(udc, 0);
1976 	spin_unlock_irqrestore(&udc->lock, flags);
1977 
1978 	device_init_wakeup(&pdev->dev, 0);
1979 	remove_debug_file(udc);
1980 	clk_unprepare(udc->fclk);
1981 	clk_unprepare(udc->iclk);
1982 
1983 	return 0;
1984 }
1985 
1986 #ifdef CONFIG_PM
1987 static int at91udc_suspend(struct platform_device *pdev, pm_message_t mesg)
1988 {
1989 	struct at91_udc *udc = platform_get_drvdata(pdev);
1990 	int		wake = udc->driver && device_may_wakeup(&pdev->dev);
1991 	unsigned long	flags;
1992 
1993 	/* Unless we can act normally to the host (letting it wake us up
1994 	 * whenever it has work for us) force disconnect.  Wakeup requires
1995 	 * PLLB for USB events (signaling for reset, wakeup, or incoming
1996 	 * tokens) and VBUS irqs (on systems which support them).
1997 	 */
1998 	if ((!udc->suspended && udc->addr)
1999 			|| !wake
2000 			|| at91_suspend_entering_slow_clock()) {
2001 		spin_lock_irqsave(&udc->lock, flags);
2002 		pullup(udc, 0);
2003 		wake = 0;
2004 		spin_unlock_irqrestore(&udc->lock, flags);
2005 	} else
2006 		enable_irq_wake(udc->udp_irq);
2007 
2008 	udc->active_suspend = wake;
2009 	if (gpio_is_valid(udc->board.vbus_pin) && !udc->board.vbus_polled && wake)
2010 		enable_irq_wake(udc->board.vbus_pin);
2011 	return 0;
2012 }
2013 
2014 static int at91udc_resume(struct platform_device *pdev)
2015 {
2016 	struct at91_udc *udc = platform_get_drvdata(pdev);
2017 	unsigned long	flags;
2018 
2019 	if (gpio_is_valid(udc->board.vbus_pin) && !udc->board.vbus_polled &&
2020 	    udc->active_suspend)
2021 		disable_irq_wake(udc->board.vbus_pin);
2022 
2023 	/* maybe reconnect to host; if so, clocks on */
2024 	if (udc->active_suspend)
2025 		disable_irq_wake(udc->udp_irq);
2026 	else {
2027 		spin_lock_irqsave(&udc->lock, flags);
2028 		pullup(udc, 1);
2029 		spin_unlock_irqrestore(&udc->lock, flags);
2030 	}
2031 	return 0;
2032 }
2033 #else
2034 #define	at91udc_suspend	NULL
2035 #define	at91udc_resume	NULL
2036 #endif
2037 
2038 static struct platform_driver at91_udc_driver = {
2039 	.remove		= at91udc_remove,
2040 	.shutdown	= at91udc_shutdown,
2041 	.suspend	= at91udc_suspend,
2042 	.resume		= at91udc_resume,
2043 	.driver		= {
2044 		.name	= (char *) driver_name,
2045 		.of_match_table	= at91_udc_dt_ids,
2046 	},
2047 };
2048 
2049 module_platform_driver_probe(at91_udc_driver, at91udc_probe);
2050 
2051 MODULE_DESCRIPTION("AT91 udc driver");
2052 MODULE_AUTHOR("Thomas Rathbone, David Brownell");
2053 MODULE_LICENSE("GPL");
2054 MODULE_ALIAS("platform:at91_udc");
2055