xref: /openbmc/linux/drivers/usb/gadget/udc/gr_udc.c (revision 842ed298)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * USB Peripheral Controller driver for Aeroflex Gaisler GRUSBDC.
4  *
5  * 2013 (c) Aeroflex Gaisler AB
6  *
7  * This driver supports GRUSBDC USB Device Controller cores available in the
8  * GRLIB VHDL IP core library.
9  *
10  * Full documentation of the GRUSBDC core can be found here:
11  * https://www.gaisler.com/products/grlib/grip.pdf
12  *
13  * Contributors:
14  * - Andreas Larsson <andreas@gaisler.com>
15  * - Marko Isomaki
16  */
17 
18 /*
19  * A GRUSBDC core can have up to 16 IN endpoints and 16 OUT endpoints each
20  * individually configurable to any of the four USB transfer types. This driver
21  * only supports cores in DMA mode.
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27 #include <linux/spinlock.h>
28 #include <linux/errno.h>
29 #include <linux/list.h>
30 #include <linux/interrupt.h>
31 #include <linux/device.h>
32 #include <linux/usb.h>
33 #include <linux/usb/ch9.h>
34 #include <linux/usb/gadget.h>
35 #include <linux/dma-mapping.h>
36 #include <linux/dmapool.h>
37 #include <linux/debugfs.h>
38 #include <linux/seq_file.h>
39 #include <linux/of_platform.h>
40 #include <linux/of_irq.h>
41 #include <linux/of_address.h>
42 
43 #include <asm/byteorder.h>
44 
45 #include "gr_udc.h"
46 
47 #define	DRIVER_NAME	"gr_udc"
48 #define	DRIVER_DESC	"Aeroflex Gaisler GRUSBDC USB Peripheral Controller"
49 
50 static const char driver_name[] = DRIVER_NAME;
51 
52 #define gr_read32(x) (ioread32be((x)))
53 #define gr_write32(x, v) (iowrite32be((v), (x)))
54 
55 /* USB speed and corresponding string calculated from status register value */
56 #define GR_SPEED(status) \
57 	((status & GR_STATUS_SP) ? USB_SPEED_FULL : USB_SPEED_HIGH)
58 #define GR_SPEED_STR(status) usb_speed_string(GR_SPEED(status))
59 
60 /* Size of hardware buffer calculated from epctrl register value */
61 #define GR_BUFFER_SIZE(epctrl)					      \
62 	((((epctrl) & GR_EPCTRL_BUFSZ_MASK) >> GR_EPCTRL_BUFSZ_POS) * \
63 	 GR_EPCTRL_BUFSZ_SCALER)
64 
65 /* ---------------------------------------------------------------------- */
66 /* Debug printout functionality */
67 
68 static const char * const gr_modestring[] = {"control", "iso", "bulk", "int"};
69 
70 static const char *gr_ep0state_string(enum gr_ep0state state)
71 {
72 	static const char *const names[] = {
73 		[GR_EP0_DISCONNECT] = "disconnect",
74 		[GR_EP0_SETUP] = "setup",
75 		[GR_EP0_IDATA] = "idata",
76 		[GR_EP0_ODATA] = "odata",
77 		[GR_EP0_ISTATUS] = "istatus",
78 		[GR_EP0_OSTATUS] = "ostatus",
79 		[GR_EP0_STALL] = "stall",
80 		[GR_EP0_SUSPEND] = "suspend",
81 	};
82 
83 	if (state < 0 || state >= ARRAY_SIZE(names))
84 		return "UNKNOWN";
85 
86 	return names[state];
87 }
88 
89 #ifdef VERBOSE_DEBUG
90 
91 static void gr_dbgprint_request(const char *str, struct gr_ep *ep,
92 				struct gr_request *req)
93 {
94 	int buflen = ep->is_in ? req->req.length : req->req.actual;
95 	int rowlen = 32;
96 	int plen = min(rowlen, buflen);
97 
98 	dev_dbg(ep->dev->dev, "%s: 0x%p, %d bytes data%s:\n", str, req, buflen,
99 		(buflen > plen ? " (truncated)" : ""));
100 	print_hex_dump_debug("   ", DUMP_PREFIX_NONE,
101 			     rowlen, 4, req->req.buf, plen, false);
102 }
103 
104 static void gr_dbgprint_devreq(struct gr_udc *dev, u8 type, u8 request,
105 			       u16 value, u16 index, u16 length)
106 {
107 	dev_vdbg(dev->dev, "REQ: %02x.%02x v%04x i%04x l%04x\n",
108 		 type, request, value, index, length);
109 }
110 #else /* !VERBOSE_DEBUG */
111 
112 static void gr_dbgprint_request(const char *str, struct gr_ep *ep,
113 				struct gr_request *req) {}
114 
115 static void gr_dbgprint_devreq(struct gr_udc *dev, u8 type, u8 request,
116 			       u16 value, u16 index, u16 length) {}
117 
118 #endif /* VERBOSE_DEBUG */
119 
120 /* ---------------------------------------------------------------------- */
121 /* Debugfs functionality */
122 
123 #ifdef CONFIG_USB_GADGET_DEBUG_FS
124 
125 static void gr_seq_ep_show(struct seq_file *seq, struct gr_ep *ep)
126 {
127 	u32 epctrl = gr_read32(&ep->regs->epctrl);
128 	u32 epstat = gr_read32(&ep->regs->epstat);
129 	int mode = (epctrl & GR_EPCTRL_TT_MASK) >> GR_EPCTRL_TT_POS;
130 	struct gr_request *req;
131 
132 	seq_printf(seq, "%s:\n", ep->ep.name);
133 	seq_printf(seq, "  mode = %s\n", gr_modestring[mode]);
134 	seq_printf(seq, "  halted: %d\n", !!(epctrl & GR_EPCTRL_EH));
135 	seq_printf(seq, "  disabled: %d\n", !!(epctrl & GR_EPCTRL_ED));
136 	seq_printf(seq, "  valid: %d\n", !!(epctrl & GR_EPCTRL_EV));
137 	seq_printf(seq, "  dma_start = %d\n", ep->dma_start);
138 	seq_printf(seq, "  stopped = %d\n", ep->stopped);
139 	seq_printf(seq, "  wedged = %d\n", ep->wedged);
140 	seq_printf(seq, "  callback = %d\n", ep->callback);
141 	seq_printf(seq, "  maxpacket = %d\n", ep->ep.maxpacket);
142 	seq_printf(seq, "  maxpacket_limit = %d\n", ep->ep.maxpacket_limit);
143 	seq_printf(seq, "  bytes_per_buffer = %d\n", ep->bytes_per_buffer);
144 	if (mode == 1 || mode == 3)
145 		seq_printf(seq, "  nt = %d\n",
146 			   (epctrl & GR_EPCTRL_NT_MASK) >> GR_EPCTRL_NT_POS);
147 
148 	seq_printf(seq, "  Buffer 0: %s %s%d\n",
149 		   epstat & GR_EPSTAT_B0 ? "valid" : "invalid",
150 		   epstat & GR_EPSTAT_BS ? " " : "selected ",
151 		   (epstat & GR_EPSTAT_B0CNT_MASK) >> GR_EPSTAT_B0CNT_POS);
152 	seq_printf(seq, "  Buffer 1: %s %s%d\n",
153 		   epstat & GR_EPSTAT_B1 ? "valid" : "invalid",
154 		   epstat & GR_EPSTAT_BS ? "selected " : " ",
155 		   (epstat & GR_EPSTAT_B1CNT_MASK) >> GR_EPSTAT_B1CNT_POS);
156 
157 	if (list_empty(&ep->queue)) {
158 		seq_puts(seq, "  Queue: empty\n\n");
159 		return;
160 	}
161 
162 	seq_puts(seq, "  Queue:\n");
163 	list_for_each_entry(req, &ep->queue, queue) {
164 		struct gr_dma_desc *desc;
165 		struct gr_dma_desc *next;
166 
167 		seq_printf(seq, "    0x%p: 0x%p %d %d\n", req,
168 			   &req->req.buf, req->req.actual, req->req.length);
169 
170 		next = req->first_desc;
171 		do {
172 			desc = next;
173 			next = desc->next_desc;
174 			seq_printf(seq, "    %c 0x%p (0x%08x): 0x%05x 0x%08x\n",
175 				   desc == req->curr_desc ? 'c' : ' ',
176 				   desc, desc->paddr, desc->ctrl, desc->data);
177 		} while (desc != req->last_desc);
178 	}
179 	seq_puts(seq, "\n");
180 }
181 
182 static int gr_dfs_show(struct seq_file *seq, void *v)
183 {
184 	struct gr_udc *dev = seq->private;
185 	u32 control = gr_read32(&dev->regs->control);
186 	u32 status = gr_read32(&dev->regs->status);
187 	struct gr_ep *ep;
188 
189 	seq_printf(seq, "usb state = %s\n",
190 		   usb_state_string(dev->gadget.state));
191 	seq_printf(seq, "address = %d\n",
192 		   (control & GR_CONTROL_UA_MASK) >> GR_CONTROL_UA_POS);
193 	seq_printf(seq, "speed = %s\n", GR_SPEED_STR(status));
194 	seq_printf(seq, "ep0state = %s\n", gr_ep0state_string(dev->ep0state));
195 	seq_printf(seq, "irq_enabled = %d\n", dev->irq_enabled);
196 	seq_printf(seq, "remote_wakeup = %d\n", dev->remote_wakeup);
197 	seq_printf(seq, "test_mode = %d\n", dev->test_mode);
198 	seq_puts(seq, "\n");
199 
200 	list_for_each_entry(ep, &dev->ep_list, ep_list)
201 		gr_seq_ep_show(seq, ep);
202 
203 	return 0;
204 }
205 DEFINE_SHOW_ATTRIBUTE(gr_dfs);
206 
207 static void gr_dfs_create(struct gr_udc *dev)
208 {
209 	const char *name = "gr_udc_state";
210 
211 	dev->dfs_root = debugfs_create_dir(dev_name(dev->dev), usb_debug_root);
212 	debugfs_create_file(name, 0444, dev->dfs_root, dev, &gr_dfs_fops);
213 }
214 
215 static void gr_dfs_delete(struct gr_udc *dev)
216 {
217 	debugfs_remove_recursive(dev->dfs_root);
218 }
219 
220 #else /* !CONFIG_USB_GADGET_DEBUG_FS */
221 
222 static void gr_dfs_create(struct gr_udc *dev) {}
223 static void gr_dfs_delete(struct gr_udc *dev) {}
224 
225 #endif /* CONFIG_USB_GADGET_DEBUG_FS */
226 
227 /* ---------------------------------------------------------------------- */
228 /* DMA and request handling */
229 
230 /* Allocates a new struct gr_dma_desc, sets paddr and zeroes the rest */
231 static struct gr_dma_desc *gr_alloc_dma_desc(struct gr_ep *ep, gfp_t gfp_flags)
232 {
233 	dma_addr_t paddr;
234 	struct gr_dma_desc *dma_desc;
235 
236 	dma_desc = dma_pool_zalloc(ep->dev->desc_pool, gfp_flags, &paddr);
237 	if (!dma_desc) {
238 		dev_err(ep->dev->dev, "Could not allocate from DMA pool\n");
239 		return NULL;
240 	}
241 
242 	dma_desc->paddr = paddr;
243 
244 	return dma_desc;
245 }
246 
247 static inline void gr_free_dma_desc(struct gr_udc *dev,
248 				    struct gr_dma_desc *desc)
249 {
250 	dma_pool_free(dev->desc_pool, desc, (dma_addr_t)desc->paddr);
251 }
252 
253 /* Frees the chain of struct gr_dma_desc for the given request */
254 static void gr_free_dma_desc_chain(struct gr_udc *dev, struct gr_request *req)
255 {
256 	struct gr_dma_desc *desc;
257 	struct gr_dma_desc *next;
258 
259 	next = req->first_desc;
260 	if (!next)
261 		return;
262 
263 	do {
264 		desc = next;
265 		next = desc->next_desc;
266 		gr_free_dma_desc(dev, desc);
267 	} while (desc != req->last_desc);
268 
269 	req->first_desc = NULL;
270 	req->curr_desc = NULL;
271 	req->last_desc = NULL;
272 }
273 
274 static void gr_ep0_setup(struct gr_udc *dev, struct gr_request *req);
275 
276 /*
277  * Frees allocated resources and calls the appropriate completion function/setup
278  * package handler for a finished request.
279  *
280  * Must be called with dev->lock held and irqs disabled.
281  */
282 static void gr_finish_request(struct gr_ep *ep, struct gr_request *req,
283 			      int status)
284 	__releases(&dev->lock)
285 	__acquires(&dev->lock)
286 {
287 	struct gr_udc *dev;
288 
289 	list_del_init(&req->queue);
290 
291 	if (likely(req->req.status == -EINPROGRESS))
292 		req->req.status = status;
293 	else
294 		status = req->req.status;
295 
296 	dev = ep->dev;
297 	usb_gadget_unmap_request(&dev->gadget, &req->req, ep->is_in);
298 	gr_free_dma_desc_chain(dev, req);
299 
300 	if (ep->is_in) { /* For OUT, req->req.actual gets updated bit by bit */
301 		req->req.actual = req->req.length;
302 	} else if (req->oddlen && req->req.actual > req->evenlen) {
303 		/*
304 		 * Copy to user buffer in this case where length was not evenly
305 		 * divisible by ep->ep.maxpacket and the last descriptor was
306 		 * actually used.
307 		 */
308 		char *buftail = ((char *)req->req.buf + req->evenlen);
309 
310 		memcpy(buftail, ep->tailbuf, req->oddlen);
311 
312 		if (req->req.actual > req->req.length) {
313 			/* We got more data than was requested */
314 			dev_dbg(ep->dev->dev, "Overflow for ep %s\n",
315 				ep->ep.name);
316 			gr_dbgprint_request("OVFL", ep, req);
317 			req->req.status = -EOVERFLOW;
318 		}
319 	}
320 
321 	if (!status) {
322 		if (ep->is_in)
323 			gr_dbgprint_request("SENT", ep, req);
324 		else
325 			gr_dbgprint_request("RECV", ep, req);
326 	}
327 
328 	/* Prevent changes to ep->queue during callback */
329 	ep->callback = 1;
330 	if (req == dev->ep0reqo && !status) {
331 		if (req->setup)
332 			gr_ep0_setup(dev, req);
333 		else
334 			dev_err(dev->dev,
335 				"Unexpected non setup packet on ep0in\n");
336 	} else if (req->req.complete) {
337 		spin_unlock(&dev->lock);
338 
339 		usb_gadget_giveback_request(&ep->ep, &req->req);
340 
341 		spin_lock(&dev->lock);
342 	}
343 	ep->callback = 0;
344 }
345 
346 static struct usb_request *gr_alloc_request(struct usb_ep *_ep, gfp_t gfp_flags)
347 {
348 	struct gr_request *req;
349 
350 	req = kzalloc(sizeof(*req), gfp_flags);
351 	if (!req)
352 		return NULL;
353 
354 	INIT_LIST_HEAD(&req->queue);
355 
356 	return &req->req;
357 }
358 
359 /*
360  * Starts DMA for endpoint ep if there are requests in the queue.
361  *
362  * Must be called with dev->lock held and with !ep->stopped.
363  */
364 static void gr_start_dma(struct gr_ep *ep)
365 {
366 	struct gr_request *req;
367 	u32 dmactrl;
368 
369 	if (list_empty(&ep->queue)) {
370 		ep->dma_start = 0;
371 		return;
372 	}
373 
374 	req = list_first_entry(&ep->queue, struct gr_request, queue);
375 
376 	/* A descriptor should already have been allocated */
377 	BUG_ON(!req->curr_desc);
378 
379 	/*
380 	 * The DMA controller can not handle smaller OUT buffers than
381 	 * ep->ep.maxpacket. It could lead to buffer overruns if an unexpectedly
382 	 * long packet are received. Therefore an internal bounce buffer gets
383 	 * used when such a request gets enabled.
384 	 */
385 	if (!ep->is_in && req->oddlen)
386 		req->last_desc->data = ep->tailbuf_paddr;
387 
388 	wmb(); /* Make sure all is settled before handing it over to DMA */
389 
390 	/* Set the descriptor pointer in the hardware */
391 	gr_write32(&ep->regs->dmaaddr, req->curr_desc->paddr);
392 
393 	/* Announce available descriptors */
394 	dmactrl = gr_read32(&ep->regs->dmactrl);
395 	gr_write32(&ep->regs->dmactrl, dmactrl | GR_DMACTRL_DA);
396 
397 	ep->dma_start = 1;
398 }
399 
400 /*
401  * Finishes the first request in the ep's queue and, if available, starts the
402  * next request in queue.
403  *
404  * Must be called with dev->lock held, irqs disabled and with !ep->stopped.
405  */
406 static void gr_dma_advance(struct gr_ep *ep, int status)
407 {
408 	struct gr_request *req;
409 
410 	req = list_first_entry(&ep->queue, struct gr_request, queue);
411 	gr_finish_request(ep, req, status);
412 	gr_start_dma(ep); /* Regardless of ep->dma_start */
413 }
414 
415 /*
416  * Abort DMA for an endpoint. Sets the abort DMA bit which causes an ongoing DMA
417  * transfer to be canceled and clears GR_DMACTRL_DA.
418  *
419  * Must be called with dev->lock held.
420  */
421 static void gr_abort_dma(struct gr_ep *ep)
422 {
423 	u32 dmactrl;
424 
425 	dmactrl = gr_read32(&ep->regs->dmactrl);
426 	gr_write32(&ep->regs->dmactrl, dmactrl | GR_DMACTRL_AD);
427 }
428 
429 /*
430  * Allocates and sets up a struct gr_dma_desc and putting it on the descriptor
431  * chain.
432  *
433  * Size is not used for OUT endpoints. Hardware can not be instructed to handle
434  * smaller buffer than MAXPL in the OUT direction.
435  */
436 static int gr_add_dma_desc(struct gr_ep *ep, struct gr_request *req,
437 			   dma_addr_t data, unsigned size, gfp_t gfp_flags)
438 {
439 	struct gr_dma_desc *desc;
440 
441 	desc = gr_alloc_dma_desc(ep, gfp_flags);
442 	if (!desc)
443 		return -ENOMEM;
444 
445 	desc->data = data;
446 	if (ep->is_in)
447 		desc->ctrl =
448 			(GR_DESC_IN_CTRL_LEN_MASK & size) | GR_DESC_IN_CTRL_EN;
449 	else
450 		desc->ctrl = GR_DESC_OUT_CTRL_IE;
451 
452 	if (!req->first_desc) {
453 		req->first_desc = desc;
454 		req->curr_desc = desc;
455 	} else {
456 		req->last_desc->next_desc = desc;
457 		req->last_desc->next = desc->paddr;
458 		req->last_desc->ctrl |= GR_DESC_OUT_CTRL_NX;
459 	}
460 	req->last_desc = desc;
461 
462 	return 0;
463 }
464 
465 /*
466  * Sets up a chain of struct gr_dma_descriptors pointing to buffers that
467  * together covers req->req.length bytes of the buffer at DMA address
468  * req->req.dma for the OUT direction.
469  *
470  * The first descriptor in the chain is enabled, the rest disabled. The
471  * interrupt handler will later enable them one by one when needed so we can
472  * find out when the transfer is finished. For OUT endpoints, all descriptors
473  * therefore generate interrutps.
474  */
475 static int gr_setup_out_desc_list(struct gr_ep *ep, struct gr_request *req,
476 				  gfp_t gfp_flags)
477 {
478 	u16 bytes_left; /* Bytes left to provide descriptors for */
479 	u16 bytes_used; /* Bytes accommodated for */
480 	int ret = 0;
481 
482 	req->first_desc = NULL; /* Signals that no allocation is done yet */
483 	bytes_left = req->req.length;
484 	bytes_used = 0;
485 	while (bytes_left > 0) {
486 		dma_addr_t start = req->req.dma + bytes_used;
487 		u16 size = min(bytes_left, ep->bytes_per_buffer);
488 
489 		if (size < ep->bytes_per_buffer) {
490 			/* Prepare using bounce buffer */
491 			req->evenlen = req->req.length - bytes_left;
492 			req->oddlen = size;
493 		}
494 
495 		ret = gr_add_dma_desc(ep, req, start, size, gfp_flags);
496 		if (ret)
497 			goto alloc_err;
498 
499 		bytes_left -= size;
500 		bytes_used += size;
501 	}
502 
503 	req->first_desc->ctrl |= GR_DESC_OUT_CTRL_EN;
504 
505 	return 0;
506 
507 alloc_err:
508 	gr_free_dma_desc_chain(ep->dev, req);
509 
510 	return ret;
511 }
512 
513 /*
514  * Sets up a chain of struct gr_dma_descriptors pointing to buffers that
515  * together covers req->req.length bytes of the buffer at DMA address
516  * req->req.dma for the IN direction.
517  *
518  * When more data is provided than the maximum payload size, the hardware splits
519  * this up into several payloads automatically. Moreover, ep->bytes_per_buffer
520  * is always set to a multiple of the maximum payload (restricted to the valid
521  * number of maximum payloads during high bandwidth isochronous or interrupt
522  * transfers)
523  *
524  * All descriptors are enabled from the beginning and we only generate an
525  * interrupt for the last one indicating that the entire request has been pushed
526  * to hardware.
527  */
528 static int gr_setup_in_desc_list(struct gr_ep *ep, struct gr_request *req,
529 				 gfp_t gfp_flags)
530 {
531 	u16 bytes_left; /* Bytes left in req to provide descriptors for */
532 	u16 bytes_used; /* Bytes in req accommodated for */
533 	int ret = 0;
534 
535 	req->first_desc = NULL; /* Signals that no allocation is done yet */
536 	bytes_left = req->req.length;
537 	bytes_used = 0;
538 	do { /* Allow for zero length packets */
539 		dma_addr_t start = req->req.dma + bytes_used;
540 		u16 size = min(bytes_left, ep->bytes_per_buffer);
541 
542 		ret = gr_add_dma_desc(ep, req, start, size, gfp_flags);
543 		if (ret)
544 			goto alloc_err;
545 
546 		bytes_left -= size;
547 		bytes_used += size;
548 	} while (bytes_left > 0);
549 
550 	/*
551 	 * Send an extra zero length packet to indicate that no more data is
552 	 * available when req->req.zero is set and the data length is even
553 	 * multiples of ep->ep.maxpacket.
554 	 */
555 	if (req->req.zero && (req->req.length % ep->ep.maxpacket == 0)) {
556 		ret = gr_add_dma_desc(ep, req, 0, 0, gfp_flags);
557 		if (ret)
558 			goto alloc_err;
559 	}
560 
561 	/*
562 	 * For IN packets we only want to know when the last packet has been
563 	 * transmitted (not just put into internal buffers).
564 	 */
565 	req->last_desc->ctrl |= GR_DESC_IN_CTRL_PI;
566 
567 	return 0;
568 
569 alloc_err:
570 	gr_free_dma_desc_chain(ep->dev, req);
571 
572 	return ret;
573 }
574 
575 /* Must be called with dev->lock held */
576 static int gr_queue(struct gr_ep *ep, struct gr_request *req, gfp_t gfp_flags)
577 {
578 	struct gr_udc *dev = ep->dev;
579 	int ret;
580 
581 	if (unlikely(!ep->ep.desc && ep->num != 0)) {
582 		dev_err(dev->dev, "No ep descriptor for %s\n", ep->ep.name);
583 		return -EINVAL;
584 	}
585 
586 	if (unlikely(!req->req.buf || !list_empty(&req->queue))) {
587 		dev_err(dev->dev,
588 			"Invalid request for %s: buf=%p list_empty=%d\n",
589 			ep->ep.name, req->req.buf, list_empty(&req->queue));
590 		return -EINVAL;
591 	}
592 
593 	if (unlikely(!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)) {
594 		dev_err(dev->dev, "-ESHUTDOWN");
595 		return -ESHUTDOWN;
596 	}
597 
598 	/* Can't touch registers when suspended */
599 	if (dev->ep0state == GR_EP0_SUSPEND) {
600 		dev_err(dev->dev, "-EBUSY");
601 		return -EBUSY;
602 	}
603 
604 	/* Set up DMA mapping in case the caller didn't */
605 	ret = usb_gadget_map_request(&dev->gadget, &req->req, ep->is_in);
606 	if (ret) {
607 		dev_err(dev->dev, "usb_gadget_map_request");
608 		return ret;
609 	}
610 
611 	if (ep->is_in)
612 		ret = gr_setup_in_desc_list(ep, req, gfp_flags);
613 	else
614 		ret = gr_setup_out_desc_list(ep, req, gfp_flags);
615 	if (ret)
616 		return ret;
617 
618 	req->req.status = -EINPROGRESS;
619 	req->req.actual = 0;
620 	list_add_tail(&req->queue, &ep->queue);
621 
622 	/* Start DMA if not started, otherwise interrupt handler handles it */
623 	if (!ep->dma_start && likely(!ep->stopped))
624 		gr_start_dma(ep);
625 
626 	return 0;
627 }
628 
629 /*
630  * Queue a request from within the driver.
631  *
632  * Must be called with dev->lock held.
633  */
634 static inline int gr_queue_int(struct gr_ep *ep, struct gr_request *req,
635 			       gfp_t gfp_flags)
636 {
637 	if (ep->is_in)
638 		gr_dbgprint_request("RESP", ep, req);
639 
640 	return gr_queue(ep, req, gfp_flags);
641 }
642 
643 /* ---------------------------------------------------------------------- */
644 /* General helper functions */
645 
646 /*
647  * Dequeue ALL requests.
648  *
649  * Must be called with dev->lock held and irqs disabled.
650  */
651 static void gr_ep_nuke(struct gr_ep *ep)
652 {
653 	struct gr_request *req;
654 
655 	ep->stopped = 1;
656 	ep->dma_start = 0;
657 	gr_abort_dma(ep);
658 
659 	while (!list_empty(&ep->queue)) {
660 		req = list_first_entry(&ep->queue, struct gr_request, queue);
661 		gr_finish_request(ep, req, -ESHUTDOWN);
662 	}
663 }
664 
665 /*
666  * Reset the hardware state of this endpoint.
667  *
668  * Must be called with dev->lock held.
669  */
670 static void gr_ep_reset(struct gr_ep *ep)
671 {
672 	gr_write32(&ep->regs->epctrl, 0);
673 	gr_write32(&ep->regs->dmactrl, 0);
674 
675 	ep->ep.maxpacket = MAX_CTRL_PL_SIZE;
676 	ep->ep.desc = NULL;
677 	ep->stopped = 1;
678 	ep->dma_start = 0;
679 }
680 
681 /*
682  * Generate STALL on ep0in/out.
683  *
684  * Must be called with dev->lock held.
685  */
686 static void gr_control_stall(struct gr_udc *dev)
687 {
688 	u32 epctrl;
689 
690 	epctrl = gr_read32(&dev->epo[0].regs->epctrl);
691 	gr_write32(&dev->epo[0].regs->epctrl, epctrl | GR_EPCTRL_CS);
692 	epctrl = gr_read32(&dev->epi[0].regs->epctrl);
693 	gr_write32(&dev->epi[0].regs->epctrl, epctrl | GR_EPCTRL_CS);
694 
695 	dev->ep0state = GR_EP0_STALL;
696 }
697 
698 /*
699  * Halts, halts and wedges, or clears halt for an endpoint.
700  *
701  * Must be called with dev->lock held.
702  */
703 static int gr_ep_halt_wedge(struct gr_ep *ep, int halt, int wedge, int fromhost)
704 {
705 	u32 epctrl;
706 	int retval = 0;
707 
708 	if (ep->num && !ep->ep.desc)
709 		return -EINVAL;
710 
711 	if (ep->num && ep->ep.desc->bmAttributes == USB_ENDPOINT_XFER_ISOC)
712 		return -EOPNOTSUPP;
713 
714 	/* Never actually halt ep0, and therefore never clear halt for ep0 */
715 	if (!ep->num) {
716 		if (halt && !fromhost) {
717 			/* ep0 halt from gadget - generate protocol stall */
718 			gr_control_stall(ep->dev);
719 			dev_dbg(ep->dev->dev, "EP: stall ep0\n");
720 			return 0;
721 		}
722 		return -EINVAL;
723 	}
724 
725 	dev_dbg(ep->dev->dev, "EP: %s halt %s\n",
726 		(halt ? (wedge ? "wedge" : "set") : "clear"), ep->ep.name);
727 
728 	epctrl = gr_read32(&ep->regs->epctrl);
729 	if (halt) {
730 		/* Set HALT */
731 		gr_write32(&ep->regs->epctrl, epctrl | GR_EPCTRL_EH);
732 		ep->stopped = 1;
733 		if (wedge)
734 			ep->wedged = 1;
735 	} else {
736 		gr_write32(&ep->regs->epctrl, epctrl & ~GR_EPCTRL_EH);
737 		ep->stopped = 0;
738 		ep->wedged = 0;
739 
740 		/* Things might have been queued up in the meantime */
741 		if (!ep->dma_start)
742 			gr_start_dma(ep);
743 	}
744 
745 	return retval;
746 }
747 
748 /* Must be called with dev->lock held */
749 static inline void gr_set_ep0state(struct gr_udc *dev, enum gr_ep0state value)
750 {
751 	if (dev->ep0state != value)
752 		dev_vdbg(dev->dev, "STATE:  ep0state=%s\n",
753 			 gr_ep0state_string(value));
754 	dev->ep0state = value;
755 }
756 
757 /*
758  * Should only be called when endpoints can not generate interrupts.
759  *
760  * Must be called with dev->lock held.
761  */
762 static void gr_disable_interrupts_and_pullup(struct gr_udc *dev)
763 {
764 	gr_write32(&dev->regs->control, 0);
765 	wmb(); /* Make sure that we do not deny one of our interrupts */
766 	dev->irq_enabled = 0;
767 }
768 
769 /*
770  * Stop all device activity and disable data line pullup.
771  *
772  * Must be called with dev->lock held and irqs disabled.
773  */
774 static void gr_stop_activity(struct gr_udc *dev)
775 {
776 	struct gr_ep *ep;
777 
778 	list_for_each_entry(ep, &dev->ep_list, ep_list)
779 		gr_ep_nuke(ep);
780 
781 	gr_disable_interrupts_and_pullup(dev);
782 
783 	gr_set_ep0state(dev, GR_EP0_DISCONNECT);
784 	usb_gadget_set_state(&dev->gadget, USB_STATE_NOTATTACHED);
785 }
786 
787 /* ---------------------------------------------------------------------- */
788 /* ep0 setup packet handling */
789 
790 static void gr_ep0_testmode_complete(struct usb_ep *_ep,
791 				     struct usb_request *_req)
792 {
793 	struct gr_ep *ep;
794 	struct gr_udc *dev;
795 	u32 control;
796 
797 	ep = container_of(_ep, struct gr_ep, ep);
798 	dev = ep->dev;
799 
800 	spin_lock(&dev->lock);
801 
802 	control = gr_read32(&dev->regs->control);
803 	control |= GR_CONTROL_TM | (dev->test_mode << GR_CONTROL_TS_POS);
804 	gr_write32(&dev->regs->control, control);
805 
806 	spin_unlock(&dev->lock);
807 }
808 
809 static void gr_ep0_dummy_complete(struct usb_ep *_ep, struct usb_request *_req)
810 {
811 	/* Nothing needs to be done here */
812 }
813 
814 /*
815  * Queue a response on ep0in.
816  *
817  * Must be called with dev->lock held.
818  */
819 static int gr_ep0_respond(struct gr_udc *dev, u8 *buf, int length,
820 			  void (*complete)(struct usb_ep *ep,
821 					   struct usb_request *req))
822 {
823 	u8 *reqbuf = dev->ep0reqi->req.buf;
824 	int status;
825 	int i;
826 
827 	for (i = 0; i < length; i++)
828 		reqbuf[i] = buf[i];
829 	dev->ep0reqi->req.length = length;
830 	dev->ep0reqi->req.complete = complete;
831 
832 	status = gr_queue_int(&dev->epi[0], dev->ep0reqi, GFP_ATOMIC);
833 	if (status < 0)
834 		dev_err(dev->dev,
835 			"Could not queue ep0in setup response: %d\n", status);
836 
837 	return status;
838 }
839 
840 /*
841  * Queue a 2 byte response on ep0in.
842  *
843  * Must be called with dev->lock held.
844  */
845 static inline int gr_ep0_respond_u16(struct gr_udc *dev, u16 response)
846 {
847 	__le16 le_response = cpu_to_le16(response);
848 
849 	return gr_ep0_respond(dev, (u8 *)&le_response, 2,
850 			      gr_ep0_dummy_complete);
851 }
852 
853 /*
854  * Queue a ZLP response on ep0in.
855  *
856  * Must be called with dev->lock held.
857  */
858 static inline int gr_ep0_respond_empty(struct gr_udc *dev)
859 {
860 	return gr_ep0_respond(dev, NULL, 0, gr_ep0_dummy_complete);
861 }
862 
863 /*
864  * This is run when a SET_ADDRESS request is received. First writes
865  * the new address to the control register which is updated internally
866  * when the next IN packet is ACKED.
867  *
868  * Must be called with dev->lock held.
869  */
870 static void gr_set_address(struct gr_udc *dev, u8 address)
871 {
872 	u32 control;
873 
874 	control = gr_read32(&dev->regs->control) & ~GR_CONTROL_UA_MASK;
875 	control |= (address << GR_CONTROL_UA_POS) & GR_CONTROL_UA_MASK;
876 	control |= GR_CONTROL_SU;
877 	gr_write32(&dev->regs->control, control);
878 }
879 
880 /*
881  * Returns negative for STALL, 0 for successful handling and positive for
882  * delegation.
883  *
884  * Must be called with dev->lock held.
885  */
886 static int gr_device_request(struct gr_udc *dev, u8 type, u8 request,
887 			     u16 value, u16 index)
888 {
889 	u16 response;
890 	u8 test;
891 
892 	switch (request) {
893 	case USB_REQ_SET_ADDRESS:
894 		dev_dbg(dev->dev, "STATUS: address %d\n", value & 0xff);
895 		gr_set_address(dev, value & 0xff);
896 		if (value)
897 			usb_gadget_set_state(&dev->gadget, USB_STATE_ADDRESS);
898 		else
899 			usb_gadget_set_state(&dev->gadget, USB_STATE_DEFAULT);
900 		return gr_ep0_respond_empty(dev);
901 
902 	case USB_REQ_GET_STATUS:
903 		/* Self powered | remote wakeup */
904 		response = 0x0001 | (dev->remote_wakeup ? 0x0002 : 0);
905 		return gr_ep0_respond_u16(dev, response);
906 
907 	case USB_REQ_SET_FEATURE:
908 		switch (value) {
909 		case USB_DEVICE_REMOTE_WAKEUP:
910 			/* Allow remote wakeup */
911 			dev->remote_wakeup = 1;
912 			return gr_ep0_respond_empty(dev);
913 
914 		case USB_DEVICE_TEST_MODE:
915 			/* The hardware does not support USB_TEST_FORCE_ENABLE */
916 			test = index >> 8;
917 			if (test >= USB_TEST_J && test <= USB_TEST_PACKET) {
918 				dev->test_mode = test;
919 				return gr_ep0_respond(dev, NULL, 0,
920 						      gr_ep0_testmode_complete);
921 			}
922 		}
923 		break;
924 
925 	case USB_REQ_CLEAR_FEATURE:
926 		switch (value) {
927 		case USB_DEVICE_REMOTE_WAKEUP:
928 			/* Disallow remote wakeup */
929 			dev->remote_wakeup = 0;
930 			return gr_ep0_respond_empty(dev);
931 		}
932 		break;
933 	}
934 
935 	return 1; /* Delegate the rest */
936 }
937 
938 /*
939  * Returns negative for STALL, 0 for successful handling and positive for
940  * delegation.
941  *
942  * Must be called with dev->lock held.
943  */
944 static int gr_interface_request(struct gr_udc *dev, u8 type, u8 request,
945 				u16 value, u16 index)
946 {
947 	if (dev->gadget.state != USB_STATE_CONFIGURED)
948 		return -1;
949 
950 	/*
951 	 * Should return STALL for invalid interfaces, but udc driver does not
952 	 * know anything about that. However, many gadget drivers do not handle
953 	 * GET_STATUS so we need to take care of that.
954 	 */
955 
956 	switch (request) {
957 	case USB_REQ_GET_STATUS:
958 		return gr_ep0_respond_u16(dev, 0x0000);
959 
960 	case USB_REQ_SET_FEATURE:
961 	case USB_REQ_CLEAR_FEATURE:
962 		/*
963 		 * No possible valid standard requests. Still let gadget drivers
964 		 * have a go at it.
965 		 */
966 		break;
967 	}
968 
969 	return 1; /* Delegate the rest */
970 }
971 
972 /*
973  * Returns negative for STALL, 0 for successful handling and positive for
974  * delegation.
975  *
976  * Must be called with dev->lock held.
977  */
978 static int gr_endpoint_request(struct gr_udc *dev, u8 type, u8 request,
979 			       u16 value, u16 index)
980 {
981 	struct gr_ep *ep;
982 	int status;
983 	int halted;
984 	u8 epnum = index & USB_ENDPOINT_NUMBER_MASK;
985 	u8 is_in = index & USB_ENDPOINT_DIR_MASK;
986 
987 	if ((is_in && epnum >= dev->nepi) || (!is_in && epnum >= dev->nepo))
988 		return -1;
989 
990 	if (dev->gadget.state != USB_STATE_CONFIGURED && epnum != 0)
991 		return -1;
992 
993 	ep = (is_in ? &dev->epi[epnum] : &dev->epo[epnum]);
994 
995 	switch (request) {
996 	case USB_REQ_GET_STATUS:
997 		halted = gr_read32(&ep->regs->epctrl) & GR_EPCTRL_EH;
998 		return gr_ep0_respond_u16(dev, halted ? 0x0001 : 0);
999 
1000 	case USB_REQ_SET_FEATURE:
1001 		switch (value) {
1002 		case USB_ENDPOINT_HALT:
1003 			status = gr_ep_halt_wedge(ep, 1, 0, 1);
1004 			if (status >= 0)
1005 				status = gr_ep0_respond_empty(dev);
1006 			return status;
1007 		}
1008 		break;
1009 
1010 	case USB_REQ_CLEAR_FEATURE:
1011 		switch (value) {
1012 		case USB_ENDPOINT_HALT:
1013 			if (ep->wedged)
1014 				return -1;
1015 			status = gr_ep_halt_wedge(ep, 0, 0, 1);
1016 			if (status >= 0)
1017 				status = gr_ep0_respond_empty(dev);
1018 			return status;
1019 		}
1020 		break;
1021 	}
1022 
1023 	return 1; /* Delegate the rest */
1024 }
1025 
1026 /* Must be called with dev->lock held */
1027 static void gr_ep0out_requeue(struct gr_udc *dev)
1028 {
1029 	int ret = gr_queue_int(&dev->epo[0], dev->ep0reqo, GFP_ATOMIC);
1030 
1031 	if (ret)
1032 		dev_err(dev->dev, "Could not queue ep0out setup request: %d\n",
1033 			ret);
1034 }
1035 
1036 /*
1037  * The main function dealing with setup requests on ep0.
1038  *
1039  * Must be called with dev->lock held and irqs disabled
1040  */
1041 static void gr_ep0_setup(struct gr_udc *dev, struct gr_request *req)
1042 	__releases(&dev->lock)
1043 	__acquires(&dev->lock)
1044 {
1045 	union {
1046 		struct usb_ctrlrequest ctrl;
1047 		u8 raw[8];
1048 		u32 word[2];
1049 	} u;
1050 	u8 type;
1051 	u8 request;
1052 	u16 value;
1053 	u16 index;
1054 	u16 length;
1055 	int i;
1056 	int status;
1057 
1058 	/* Restore from ep0 halt */
1059 	if (dev->ep0state == GR_EP0_STALL) {
1060 		gr_set_ep0state(dev, GR_EP0_SETUP);
1061 		if (!req->req.actual)
1062 			goto out;
1063 	}
1064 
1065 	if (dev->ep0state == GR_EP0_ISTATUS) {
1066 		gr_set_ep0state(dev, GR_EP0_SETUP);
1067 		if (req->req.actual > 0)
1068 			dev_dbg(dev->dev,
1069 				"Unexpected setup packet at state %s\n",
1070 				gr_ep0state_string(GR_EP0_ISTATUS));
1071 		else
1072 			goto out; /* Got expected ZLP */
1073 	} else if (dev->ep0state != GR_EP0_SETUP) {
1074 		dev_info(dev->dev,
1075 			 "Unexpected ep0out request at state %s - stalling\n",
1076 			 gr_ep0state_string(dev->ep0state));
1077 		gr_control_stall(dev);
1078 		gr_set_ep0state(dev, GR_EP0_SETUP);
1079 		goto out;
1080 	} else if (!req->req.actual) {
1081 		dev_dbg(dev->dev, "Unexpected ZLP at state %s\n",
1082 			gr_ep0state_string(dev->ep0state));
1083 		goto out;
1084 	}
1085 
1086 	/* Handle SETUP packet */
1087 	for (i = 0; i < req->req.actual; i++)
1088 		u.raw[i] = ((u8 *)req->req.buf)[i];
1089 
1090 	type = u.ctrl.bRequestType;
1091 	request = u.ctrl.bRequest;
1092 	value = le16_to_cpu(u.ctrl.wValue);
1093 	index = le16_to_cpu(u.ctrl.wIndex);
1094 	length = le16_to_cpu(u.ctrl.wLength);
1095 
1096 	gr_dbgprint_devreq(dev, type, request, value, index, length);
1097 
1098 	/* Check for data stage */
1099 	if (length) {
1100 		if (type & USB_DIR_IN)
1101 			gr_set_ep0state(dev, GR_EP0_IDATA);
1102 		else
1103 			gr_set_ep0state(dev, GR_EP0_ODATA);
1104 	}
1105 
1106 	status = 1; /* Positive status flags delegation */
1107 	if ((type & USB_TYPE_MASK) == USB_TYPE_STANDARD) {
1108 		switch (type & USB_RECIP_MASK) {
1109 		case USB_RECIP_DEVICE:
1110 			status = gr_device_request(dev, type, request,
1111 						   value, index);
1112 			break;
1113 		case USB_RECIP_ENDPOINT:
1114 			status =  gr_endpoint_request(dev, type, request,
1115 						      value, index);
1116 			break;
1117 		case USB_RECIP_INTERFACE:
1118 			status = gr_interface_request(dev, type, request,
1119 						      value, index);
1120 			break;
1121 		}
1122 	}
1123 
1124 	if (status > 0) {
1125 		spin_unlock(&dev->lock);
1126 
1127 		dev_vdbg(dev->dev, "DELEGATE\n");
1128 		status = dev->driver->setup(&dev->gadget, &u.ctrl);
1129 
1130 		spin_lock(&dev->lock);
1131 	}
1132 
1133 	/* Generate STALL on both ep0out and ep0in if requested */
1134 	if (unlikely(status < 0)) {
1135 		dev_vdbg(dev->dev, "STALL\n");
1136 		gr_control_stall(dev);
1137 	}
1138 
1139 	if ((type & USB_TYPE_MASK) == USB_TYPE_STANDARD &&
1140 	    request == USB_REQ_SET_CONFIGURATION) {
1141 		if (!value) {
1142 			dev_dbg(dev->dev, "STATUS: deconfigured\n");
1143 			usb_gadget_set_state(&dev->gadget, USB_STATE_ADDRESS);
1144 		} else if (status >= 0) {
1145 			/* Not configured unless gadget OK:s it */
1146 			dev_dbg(dev->dev, "STATUS: configured: %d\n", value);
1147 			usb_gadget_set_state(&dev->gadget,
1148 					     USB_STATE_CONFIGURED);
1149 		}
1150 	}
1151 
1152 	/* Get ready for next stage */
1153 	if (dev->ep0state == GR_EP0_ODATA)
1154 		gr_set_ep0state(dev, GR_EP0_OSTATUS);
1155 	else if (dev->ep0state == GR_EP0_IDATA)
1156 		gr_set_ep0state(dev, GR_EP0_ISTATUS);
1157 	else
1158 		gr_set_ep0state(dev, GR_EP0_SETUP);
1159 
1160 out:
1161 	gr_ep0out_requeue(dev);
1162 }
1163 
1164 /* ---------------------------------------------------------------------- */
1165 /* VBUS and USB reset handling */
1166 
1167 /* Must be called with dev->lock held and irqs disabled  */
1168 static void gr_vbus_connected(struct gr_udc *dev, u32 status)
1169 {
1170 	u32 control;
1171 
1172 	dev->gadget.speed = GR_SPEED(status);
1173 	usb_gadget_set_state(&dev->gadget, USB_STATE_POWERED);
1174 
1175 	/* Turn on full interrupts and pullup */
1176 	control = (GR_CONTROL_SI | GR_CONTROL_UI | GR_CONTROL_VI |
1177 		   GR_CONTROL_SP | GR_CONTROL_EP);
1178 	gr_write32(&dev->regs->control, control);
1179 }
1180 
1181 /* Must be called with dev->lock held */
1182 static void gr_enable_vbus_detect(struct gr_udc *dev)
1183 {
1184 	u32 status;
1185 
1186 	dev->irq_enabled = 1;
1187 	wmb(); /* Make sure we do not ignore an interrupt */
1188 	gr_write32(&dev->regs->control, GR_CONTROL_VI);
1189 
1190 	/* Take care of the case we are already plugged in at this point */
1191 	status = gr_read32(&dev->regs->status);
1192 	if (status & GR_STATUS_VB)
1193 		gr_vbus_connected(dev, status);
1194 }
1195 
1196 /* Must be called with dev->lock held and irqs disabled */
1197 static void gr_vbus_disconnected(struct gr_udc *dev)
1198 {
1199 	gr_stop_activity(dev);
1200 
1201 	/* Report disconnect */
1202 	if (dev->driver && dev->driver->disconnect) {
1203 		spin_unlock(&dev->lock);
1204 
1205 		dev->driver->disconnect(&dev->gadget);
1206 
1207 		spin_lock(&dev->lock);
1208 	}
1209 
1210 	gr_enable_vbus_detect(dev);
1211 }
1212 
1213 /* Must be called with dev->lock held and irqs disabled */
1214 static void gr_udc_usbreset(struct gr_udc *dev, u32 status)
1215 {
1216 	gr_set_address(dev, 0);
1217 	gr_set_ep0state(dev, GR_EP0_SETUP);
1218 	usb_gadget_set_state(&dev->gadget, USB_STATE_DEFAULT);
1219 	dev->gadget.speed = GR_SPEED(status);
1220 
1221 	gr_ep_nuke(&dev->epo[0]);
1222 	gr_ep_nuke(&dev->epi[0]);
1223 	dev->epo[0].stopped = 0;
1224 	dev->epi[0].stopped = 0;
1225 	gr_ep0out_requeue(dev);
1226 }
1227 
1228 /* ---------------------------------------------------------------------- */
1229 /* Irq handling */
1230 
1231 /*
1232  * Handles interrupts from in endpoints. Returns whether something was handled.
1233  *
1234  * Must be called with dev->lock held, irqs disabled and with !ep->stopped.
1235  */
1236 static int gr_handle_in_ep(struct gr_ep *ep)
1237 {
1238 	struct gr_request *req;
1239 
1240 	req = list_first_entry(&ep->queue, struct gr_request, queue);
1241 	if (!req->last_desc)
1242 		return 0;
1243 
1244 	if (READ_ONCE(req->last_desc->ctrl) & GR_DESC_IN_CTRL_EN)
1245 		return 0; /* Not put in hardware buffers yet */
1246 
1247 	if (gr_read32(&ep->regs->epstat) & (GR_EPSTAT_B1 | GR_EPSTAT_B0))
1248 		return 0; /* Not transmitted yet, still in hardware buffers */
1249 
1250 	/* Write complete */
1251 	gr_dma_advance(ep, 0);
1252 
1253 	return 1;
1254 }
1255 
1256 /*
1257  * Handles interrupts from out endpoints. Returns whether something was handled.
1258  *
1259  * Must be called with dev->lock held, irqs disabled and with !ep->stopped.
1260  */
1261 static int gr_handle_out_ep(struct gr_ep *ep)
1262 {
1263 	u32 ep_dmactrl;
1264 	u32 ctrl;
1265 	u16 len;
1266 	struct gr_request *req;
1267 	struct gr_udc *dev = ep->dev;
1268 
1269 	req = list_first_entry(&ep->queue, struct gr_request, queue);
1270 	if (!req->curr_desc)
1271 		return 0;
1272 
1273 	ctrl = READ_ONCE(req->curr_desc->ctrl);
1274 	if (ctrl & GR_DESC_OUT_CTRL_EN)
1275 		return 0; /* Not received yet */
1276 
1277 	/* Read complete */
1278 	len = ctrl & GR_DESC_OUT_CTRL_LEN_MASK;
1279 	req->req.actual += len;
1280 	if (ctrl & GR_DESC_OUT_CTRL_SE)
1281 		req->setup = 1;
1282 
1283 	if (len < ep->ep.maxpacket || req->req.actual >= req->req.length) {
1284 		/* Short packet or >= expected size - we are done */
1285 
1286 		if ((ep == &dev->epo[0]) && (dev->ep0state == GR_EP0_OSTATUS)) {
1287 			/*
1288 			 * Send a status stage ZLP to ack the DATA stage in the
1289 			 * OUT direction. This needs to be done before
1290 			 * gr_dma_advance as that can lead to a call to
1291 			 * ep0_setup that can change dev->ep0state.
1292 			 */
1293 			gr_ep0_respond_empty(dev);
1294 			gr_set_ep0state(dev, GR_EP0_SETUP);
1295 		}
1296 
1297 		gr_dma_advance(ep, 0);
1298 	} else {
1299 		/* Not done yet. Enable the next descriptor to receive more. */
1300 		req->curr_desc = req->curr_desc->next_desc;
1301 		req->curr_desc->ctrl |= GR_DESC_OUT_CTRL_EN;
1302 
1303 		ep_dmactrl = gr_read32(&ep->regs->dmactrl);
1304 		gr_write32(&ep->regs->dmactrl, ep_dmactrl | GR_DMACTRL_DA);
1305 	}
1306 
1307 	return 1;
1308 }
1309 
1310 /*
1311  * Handle state changes. Returns whether something was handled.
1312  *
1313  * Must be called with dev->lock held and irqs disabled.
1314  */
1315 static int gr_handle_state_changes(struct gr_udc *dev)
1316 {
1317 	u32 status = gr_read32(&dev->regs->status);
1318 	int handled = 0;
1319 	int powstate = !(dev->gadget.state == USB_STATE_NOTATTACHED ||
1320 			 dev->gadget.state == USB_STATE_ATTACHED);
1321 
1322 	/* VBUS valid detected */
1323 	if (!powstate && (status & GR_STATUS_VB)) {
1324 		dev_dbg(dev->dev, "STATUS: vbus valid detected\n");
1325 		gr_vbus_connected(dev, status);
1326 		handled = 1;
1327 	}
1328 
1329 	/* Disconnect */
1330 	if (powstate && !(status & GR_STATUS_VB)) {
1331 		dev_dbg(dev->dev, "STATUS: vbus invalid detected\n");
1332 		gr_vbus_disconnected(dev);
1333 		handled = 1;
1334 	}
1335 
1336 	/* USB reset detected */
1337 	if (status & GR_STATUS_UR) {
1338 		dev_dbg(dev->dev, "STATUS: USB reset - speed is %s\n",
1339 			GR_SPEED_STR(status));
1340 		gr_write32(&dev->regs->status, GR_STATUS_UR);
1341 		gr_udc_usbreset(dev, status);
1342 		handled = 1;
1343 	}
1344 
1345 	/* Speed change */
1346 	if (dev->gadget.speed != GR_SPEED(status)) {
1347 		dev_dbg(dev->dev, "STATUS: USB Speed change to %s\n",
1348 			GR_SPEED_STR(status));
1349 		dev->gadget.speed = GR_SPEED(status);
1350 		handled = 1;
1351 	}
1352 
1353 	/* Going into suspend */
1354 	if ((dev->ep0state != GR_EP0_SUSPEND) && !(status & GR_STATUS_SU)) {
1355 		dev_dbg(dev->dev, "STATUS: USB suspend\n");
1356 		gr_set_ep0state(dev, GR_EP0_SUSPEND);
1357 		dev->suspended_from = dev->gadget.state;
1358 		usb_gadget_set_state(&dev->gadget, USB_STATE_SUSPENDED);
1359 
1360 		if ((dev->gadget.speed != USB_SPEED_UNKNOWN) &&
1361 		    dev->driver && dev->driver->suspend) {
1362 			spin_unlock(&dev->lock);
1363 
1364 			dev->driver->suspend(&dev->gadget);
1365 
1366 			spin_lock(&dev->lock);
1367 		}
1368 		handled = 1;
1369 	}
1370 
1371 	/* Coming out of suspend */
1372 	if ((dev->ep0state == GR_EP0_SUSPEND) && (status & GR_STATUS_SU)) {
1373 		dev_dbg(dev->dev, "STATUS: USB resume\n");
1374 		if (dev->suspended_from == USB_STATE_POWERED)
1375 			gr_set_ep0state(dev, GR_EP0_DISCONNECT);
1376 		else
1377 			gr_set_ep0state(dev, GR_EP0_SETUP);
1378 		usb_gadget_set_state(&dev->gadget, dev->suspended_from);
1379 
1380 		if ((dev->gadget.speed != USB_SPEED_UNKNOWN) &&
1381 		    dev->driver && dev->driver->resume) {
1382 			spin_unlock(&dev->lock);
1383 
1384 			dev->driver->resume(&dev->gadget);
1385 
1386 			spin_lock(&dev->lock);
1387 		}
1388 		handled = 1;
1389 	}
1390 
1391 	return handled;
1392 }
1393 
1394 /* Non-interrupt context irq handler */
1395 static irqreturn_t gr_irq_handler(int irq, void *_dev)
1396 {
1397 	struct gr_udc *dev = _dev;
1398 	struct gr_ep *ep;
1399 	int handled = 0;
1400 	int i;
1401 	unsigned long flags;
1402 
1403 	spin_lock_irqsave(&dev->lock, flags);
1404 
1405 	if (!dev->irq_enabled)
1406 		goto out;
1407 
1408 	/*
1409 	 * Check IN ep interrupts. We check these before the OUT eps because
1410 	 * some gadgets reuse the request that might already be currently
1411 	 * outstanding and needs to be completed (mainly setup requests).
1412 	 */
1413 	for (i = 0; i < dev->nepi; i++) {
1414 		ep = &dev->epi[i];
1415 		if (!ep->stopped && !ep->callback && !list_empty(&ep->queue))
1416 			handled = gr_handle_in_ep(ep) || handled;
1417 	}
1418 
1419 	/* Check OUT ep interrupts */
1420 	for (i = 0; i < dev->nepo; i++) {
1421 		ep = &dev->epo[i];
1422 		if (!ep->stopped && !ep->callback && !list_empty(&ep->queue))
1423 			handled = gr_handle_out_ep(ep) || handled;
1424 	}
1425 
1426 	/* Check status interrupts */
1427 	handled = gr_handle_state_changes(dev) || handled;
1428 
1429 	/*
1430 	 * Check AMBA DMA errors. Only check if we didn't find anything else to
1431 	 * handle because this shouldn't happen if we did everything right.
1432 	 */
1433 	if (!handled) {
1434 		list_for_each_entry(ep, &dev->ep_list, ep_list) {
1435 			if (gr_read32(&ep->regs->dmactrl) & GR_DMACTRL_AE) {
1436 				dev_err(dev->dev,
1437 					"AMBA Error occurred for %s\n",
1438 					ep->ep.name);
1439 				handled = 1;
1440 			}
1441 		}
1442 	}
1443 
1444 out:
1445 	spin_unlock_irqrestore(&dev->lock, flags);
1446 
1447 	return handled ? IRQ_HANDLED : IRQ_NONE;
1448 }
1449 
1450 /* Interrupt context irq handler */
1451 static irqreturn_t gr_irq(int irq, void *_dev)
1452 {
1453 	struct gr_udc *dev = _dev;
1454 
1455 	if (!dev->irq_enabled)
1456 		return IRQ_NONE;
1457 
1458 	return IRQ_WAKE_THREAD;
1459 }
1460 
1461 /* ---------------------------------------------------------------------- */
1462 /* USB ep ops */
1463 
1464 /* Enable endpoint. Not for ep0in and ep0out that are handled separately. */
1465 static int gr_ep_enable(struct usb_ep *_ep,
1466 			const struct usb_endpoint_descriptor *desc)
1467 {
1468 	struct gr_udc *dev;
1469 	struct gr_ep *ep;
1470 	u8 mode;
1471 	u8 nt;
1472 	u16 max;
1473 	u16 buffer_size = 0;
1474 	u32 epctrl;
1475 
1476 	ep = container_of(_ep, struct gr_ep, ep);
1477 	if (!_ep || !desc || desc->bDescriptorType != USB_DT_ENDPOINT)
1478 		return -EINVAL;
1479 
1480 	dev = ep->dev;
1481 
1482 	/* 'ep0' IN and OUT are reserved */
1483 	if (ep == &dev->epo[0] || ep == &dev->epi[0])
1484 		return -EINVAL;
1485 
1486 	if (!dev->driver || dev->gadget.speed == USB_SPEED_UNKNOWN)
1487 		return -ESHUTDOWN;
1488 
1489 	/* Make sure we are clear for enabling */
1490 	epctrl = gr_read32(&ep->regs->epctrl);
1491 	if (epctrl & GR_EPCTRL_EV)
1492 		return -EBUSY;
1493 
1494 	/* Check that directions match */
1495 	if (!ep->is_in != !usb_endpoint_dir_in(desc))
1496 		return -EINVAL;
1497 
1498 	/* Check ep num */
1499 	if ((!ep->is_in && ep->num >= dev->nepo) ||
1500 	    (ep->is_in && ep->num >= dev->nepi))
1501 		return -EINVAL;
1502 
1503 	if (usb_endpoint_xfer_control(desc)) {
1504 		mode = 0;
1505 	} else if (usb_endpoint_xfer_isoc(desc)) {
1506 		mode = 1;
1507 	} else if (usb_endpoint_xfer_bulk(desc)) {
1508 		mode = 2;
1509 	} else if (usb_endpoint_xfer_int(desc)) {
1510 		mode = 3;
1511 	} else {
1512 		dev_err(dev->dev, "Unknown transfer type for %s\n",
1513 			ep->ep.name);
1514 		return -EINVAL;
1515 	}
1516 
1517 	/*
1518 	 * Bits 10-0 set the max payload. 12-11 set the number of
1519 	 * additional transactions.
1520 	 */
1521 	max = usb_endpoint_maxp(desc);
1522 	nt = usb_endpoint_maxp_mult(desc) - 1;
1523 	buffer_size = GR_BUFFER_SIZE(epctrl);
1524 	if (nt && (mode == 0 || mode == 2)) {
1525 		dev_err(dev->dev,
1526 			"%s mode: multiple trans./microframe not valid\n",
1527 			(mode == 2 ? "Bulk" : "Control"));
1528 		return -EINVAL;
1529 	} else if (nt == 0x3) {
1530 		dev_err(dev->dev,
1531 			"Invalid value 0x3 for additional trans./microframe\n");
1532 		return -EINVAL;
1533 	} else if ((nt + 1) * max > buffer_size) {
1534 		dev_err(dev->dev, "Hw buffer size %d < max payload %d * %d\n",
1535 			buffer_size, (nt + 1), max);
1536 		return -EINVAL;
1537 	} else if (max == 0) {
1538 		dev_err(dev->dev, "Max payload cannot be set to 0\n");
1539 		return -EINVAL;
1540 	} else if (max > ep->ep.maxpacket_limit) {
1541 		dev_err(dev->dev, "Requested max payload %d > limit %d\n",
1542 			max, ep->ep.maxpacket_limit);
1543 		return -EINVAL;
1544 	}
1545 
1546 	spin_lock(&ep->dev->lock);
1547 
1548 	if (!ep->stopped) {
1549 		spin_unlock(&ep->dev->lock);
1550 		return -EBUSY;
1551 	}
1552 
1553 	ep->stopped = 0;
1554 	ep->wedged = 0;
1555 	ep->ep.desc = desc;
1556 	ep->ep.maxpacket = max;
1557 	ep->dma_start = 0;
1558 
1559 
1560 	if (nt) {
1561 		/*
1562 		 * Maximum possible size of all payloads in one microframe
1563 		 * regardless of direction when using high-bandwidth mode.
1564 		 */
1565 		ep->bytes_per_buffer = (nt + 1) * max;
1566 	} else if (ep->is_in) {
1567 		/*
1568 		 * The biggest multiple of maximum packet size that fits into
1569 		 * the buffer. The hardware will split up into many packets in
1570 		 * the IN direction.
1571 		 */
1572 		ep->bytes_per_buffer = (buffer_size / max) * max;
1573 	} else {
1574 		/*
1575 		 * Only single packets will be placed the buffers in the OUT
1576 		 * direction.
1577 		 */
1578 		ep->bytes_per_buffer = max;
1579 	}
1580 
1581 	epctrl = (max << GR_EPCTRL_MAXPL_POS)
1582 		| (nt << GR_EPCTRL_NT_POS)
1583 		| (mode << GR_EPCTRL_TT_POS)
1584 		| GR_EPCTRL_EV;
1585 	if (ep->is_in)
1586 		epctrl |= GR_EPCTRL_PI;
1587 	gr_write32(&ep->regs->epctrl, epctrl);
1588 
1589 	gr_write32(&ep->regs->dmactrl, GR_DMACTRL_IE | GR_DMACTRL_AI);
1590 
1591 	spin_unlock(&ep->dev->lock);
1592 
1593 	dev_dbg(ep->dev->dev, "EP: %s enabled - %s with %d bytes/buffer\n",
1594 		ep->ep.name, gr_modestring[mode], ep->bytes_per_buffer);
1595 	return 0;
1596 }
1597 
1598 /* Disable endpoint. Not for ep0in and ep0out that are handled separately. */
1599 static int gr_ep_disable(struct usb_ep *_ep)
1600 {
1601 	struct gr_ep *ep;
1602 	struct gr_udc *dev;
1603 	unsigned long flags;
1604 
1605 	ep = container_of(_ep, struct gr_ep, ep);
1606 	if (!_ep || !ep->ep.desc)
1607 		return -ENODEV;
1608 
1609 	dev = ep->dev;
1610 
1611 	/* 'ep0' IN and OUT are reserved */
1612 	if (ep == &dev->epo[0] || ep == &dev->epi[0])
1613 		return -EINVAL;
1614 
1615 	if (dev->ep0state == GR_EP0_SUSPEND)
1616 		return -EBUSY;
1617 
1618 	dev_dbg(ep->dev->dev, "EP: disable %s\n", ep->ep.name);
1619 
1620 	spin_lock_irqsave(&dev->lock, flags);
1621 
1622 	gr_ep_nuke(ep);
1623 	gr_ep_reset(ep);
1624 	ep->ep.desc = NULL;
1625 
1626 	spin_unlock_irqrestore(&dev->lock, flags);
1627 
1628 	return 0;
1629 }
1630 
1631 /*
1632  * Frees a request, but not any DMA buffers associated with it
1633  * (gr_finish_request should already have taken care of that).
1634  */
1635 static void gr_free_request(struct usb_ep *_ep, struct usb_request *_req)
1636 {
1637 	struct gr_request *req;
1638 
1639 	if (!_ep || !_req)
1640 		return;
1641 	req = container_of(_req, struct gr_request, req);
1642 
1643 	/* Leads to memory leak */
1644 	WARN(!list_empty(&req->queue),
1645 	     "request not dequeued properly before freeing\n");
1646 
1647 	kfree(req);
1648 }
1649 
1650 /* Queue a request from the gadget */
1651 static int gr_queue_ext(struct usb_ep *_ep, struct usb_request *_req,
1652 			gfp_t gfp_flags)
1653 {
1654 	struct gr_ep *ep;
1655 	struct gr_request *req;
1656 	struct gr_udc *dev;
1657 	int ret;
1658 
1659 	if (unlikely(!_ep || !_req))
1660 		return -EINVAL;
1661 
1662 	ep = container_of(_ep, struct gr_ep, ep);
1663 	req = container_of(_req, struct gr_request, req);
1664 	dev = ep->dev;
1665 
1666 	spin_lock(&ep->dev->lock);
1667 
1668 	/*
1669 	 * The ep0 pointer in the gadget struct is used both for ep0in and
1670 	 * ep0out. In a data stage in the out direction ep0out needs to be used
1671 	 * instead of the default ep0in. Completion functions might use
1672 	 * driver_data, so that needs to be copied as well.
1673 	 */
1674 	if ((ep == &dev->epi[0]) && (dev->ep0state == GR_EP0_ODATA)) {
1675 		ep = &dev->epo[0];
1676 		ep->ep.driver_data = dev->epi[0].ep.driver_data;
1677 	}
1678 
1679 	if (ep->is_in)
1680 		gr_dbgprint_request("EXTERN", ep, req);
1681 
1682 	ret = gr_queue(ep, req, GFP_ATOMIC);
1683 
1684 	spin_unlock(&ep->dev->lock);
1685 
1686 	return ret;
1687 }
1688 
1689 /* Dequeue JUST ONE request */
1690 static int gr_dequeue(struct usb_ep *_ep, struct usb_request *_req)
1691 {
1692 	struct gr_request *req;
1693 	struct gr_ep *ep;
1694 	struct gr_udc *dev;
1695 	int ret = 0;
1696 	unsigned long flags;
1697 
1698 	ep = container_of(_ep, struct gr_ep, ep);
1699 	if (!_ep || !_req || (!ep->ep.desc && ep->num != 0))
1700 		return -EINVAL;
1701 	dev = ep->dev;
1702 	if (!dev->driver)
1703 		return -ESHUTDOWN;
1704 
1705 	/* We can't touch (DMA) registers when suspended */
1706 	if (dev->ep0state == GR_EP0_SUSPEND)
1707 		return -EBUSY;
1708 
1709 	spin_lock_irqsave(&dev->lock, flags);
1710 
1711 	/* Make sure it's actually queued on this endpoint */
1712 	list_for_each_entry(req, &ep->queue, queue) {
1713 		if (&req->req == _req)
1714 			break;
1715 	}
1716 	if (&req->req != _req) {
1717 		ret = -EINVAL;
1718 		goto out;
1719 	}
1720 
1721 	if (list_first_entry(&ep->queue, struct gr_request, queue) == req) {
1722 		/* This request is currently being processed */
1723 		gr_abort_dma(ep);
1724 		if (ep->stopped)
1725 			gr_finish_request(ep, req, -ECONNRESET);
1726 		else
1727 			gr_dma_advance(ep, -ECONNRESET);
1728 	} else if (!list_empty(&req->queue)) {
1729 		/* Not being processed - gr_finish_request dequeues it */
1730 		gr_finish_request(ep, req, -ECONNRESET);
1731 	} else {
1732 		ret = -EOPNOTSUPP;
1733 	}
1734 
1735 out:
1736 	spin_unlock_irqrestore(&dev->lock, flags);
1737 
1738 	return ret;
1739 }
1740 
1741 /* Helper for gr_set_halt and gr_set_wedge */
1742 static int gr_set_halt_wedge(struct usb_ep *_ep, int halt, int wedge)
1743 {
1744 	int ret;
1745 	struct gr_ep *ep;
1746 
1747 	if (!_ep)
1748 		return -ENODEV;
1749 	ep = container_of(_ep, struct gr_ep, ep);
1750 
1751 	spin_lock(&ep->dev->lock);
1752 
1753 	/* Halting an IN endpoint should fail if queue is not empty */
1754 	if (halt && ep->is_in && !list_empty(&ep->queue)) {
1755 		ret = -EAGAIN;
1756 		goto out;
1757 	}
1758 
1759 	ret = gr_ep_halt_wedge(ep, halt, wedge, 0);
1760 
1761 out:
1762 	spin_unlock(&ep->dev->lock);
1763 
1764 	return ret;
1765 }
1766 
1767 /* Halt endpoint */
1768 static int gr_set_halt(struct usb_ep *_ep, int halt)
1769 {
1770 	return gr_set_halt_wedge(_ep, halt, 0);
1771 }
1772 
1773 /* Halt and wedge endpoint */
1774 static int gr_set_wedge(struct usb_ep *_ep)
1775 {
1776 	return gr_set_halt_wedge(_ep, 1, 1);
1777 }
1778 
1779 /*
1780  * Return the total number of bytes currently stored in the internal buffers of
1781  * the endpoint.
1782  */
1783 static int gr_fifo_status(struct usb_ep *_ep)
1784 {
1785 	struct gr_ep *ep;
1786 	u32 epstat;
1787 	u32 bytes = 0;
1788 
1789 	if (!_ep)
1790 		return -ENODEV;
1791 	ep = container_of(_ep, struct gr_ep, ep);
1792 
1793 	epstat = gr_read32(&ep->regs->epstat);
1794 
1795 	if (epstat & GR_EPSTAT_B0)
1796 		bytes += (epstat & GR_EPSTAT_B0CNT_MASK) >> GR_EPSTAT_B0CNT_POS;
1797 	if (epstat & GR_EPSTAT_B1)
1798 		bytes += (epstat & GR_EPSTAT_B1CNT_MASK) >> GR_EPSTAT_B1CNT_POS;
1799 
1800 	return bytes;
1801 }
1802 
1803 
1804 /* Empty data from internal buffers of an endpoint. */
1805 static void gr_fifo_flush(struct usb_ep *_ep)
1806 {
1807 	struct gr_ep *ep;
1808 	u32 epctrl;
1809 
1810 	if (!_ep)
1811 		return;
1812 	ep = container_of(_ep, struct gr_ep, ep);
1813 	dev_vdbg(ep->dev->dev, "EP: flush fifo %s\n", ep->ep.name);
1814 
1815 	spin_lock(&ep->dev->lock);
1816 
1817 	epctrl = gr_read32(&ep->regs->epctrl);
1818 	epctrl |= GR_EPCTRL_CB;
1819 	gr_write32(&ep->regs->epctrl, epctrl);
1820 
1821 	spin_unlock(&ep->dev->lock);
1822 }
1823 
1824 static const struct usb_ep_ops gr_ep_ops = {
1825 	.enable		= gr_ep_enable,
1826 	.disable	= gr_ep_disable,
1827 
1828 	.alloc_request	= gr_alloc_request,
1829 	.free_request	= gr_free_request,
1830 
1831 	.queue		= gr_queue_ext,
1832 	.dequeue	= gr_dequeue,
1833 
1834 	.set_halt	= gr_set_halt,
1835 	.set_wedge	= gr_set_wedge,
1836 	.fifo_status	= gr_fifo_status,
1837 	.fifo_flush	= gr_fifo_flush,
1838 };
1839 
1840 /* ---------------------------------------------------------------------- */
1841 /* USB Gadget ops */
1842 
1843 static int gr_get_frame(struct usb_gadget *_gadget)
1844 {
1845 	struct gr_udc *dev;
1846 
1847 	if (!_gadget)
1848 		return -ENODEV;
1849 	dev = container_of(_gadget, struct gr_udc, gadget);
1850 	return gr_read32(&dev->regs->status) & GR_STATUS_FN_MASK;
1851 }
1852 
1853 static int gr_wakeup(struct usb_gadget *_gadget)
1854 {
1855 	struct gr_udc *dev;
1856 
1857 	if (!_gadget)
1858 		return -ENODEV;
1859 	dev = container_of(_gadget, struct gr_udc, gadget);
1860 
1861 	/* Remote wakeup feature not enabled by host*/
1862 	if (!dev->remote_wakeup)
1863 		return -EINVAL;
1864 
1865 	spin_lock(&dev->lock);
1866 
1867 	gr_write32(&dev->regs->control,
1868 		   gr_read32(&dev->regs->control) | GR_CONTROL_RW);
1869 
1870 	spin_unlock(&dev->lock);
1871 
1872 	return 0;
1873 }
1874 
1875 static int gr_pullup(struct usb_gadget *_gadget, int is_on)
1876 {
1877 	struct gr_udc *dev;
1878 	u32 control;
1879 
1880 	if (!_gadget)
1881 		return -ENODEV;
1882 	dev = container_of(_gadget, struct gr_udc, gadget);
1883 
1884 	spin_lock(&dev->lock);
1885 
1886 	control = gr_read32(&dev->regs->control);
1887 	if (is_on)
1888 		control |= GR_CONTROL_EP;
1889 	else
1890 		control &= ~GR_CONTROL_EP;
1891 	gr_write32(&dev->regs->control, control);
1892 
1893 	spin_unlock(&dev->lock);
1894 
1895 	return 0;
1896 }
1897 
1898 static int gr_udc_start(struct usb_gadget *gadget,
1899 			struct usb_gadget_driver *driver)
1900 {
1901 	struct gr_udc *dev = to_gr_udc(gadget);
1902 
1903 	spin_lock(&dev->lock);
1904 
1905 	/* Hook up the driver */
1906 	driver->driver.bus = NULL;
1907 	dev->driver = driver;
1908 
1909 	/* Get ready for host detection */
1910 	gr_enable_vbus_detect(dev);
1911 
1912 	spin_unlock(&dev->lock);
1913 
1914 	return 0;
1915 }
1916 
1917 static int gr_udc_stop(struct usb_gadget *gadget)
1918 {
1919 	struct gr_udc *dev = to_gr_udc(gadget);
1920 	unsigned long flags;
1921 
1922 	spin_lock_irqsave(&dev->lock, flags);
1923 
1924 	dev->driver = NULL;
1925 	gr_stop_activity(dev);
1926 
1927 	spin_unlock_irqrestore(&dev->lock, flags);
1928 
1929 	return 0;
1930 }
1931 
1932 static const struct usb_gadget_ops gr_ops = {
1933 	.get_frame	= gr_get_frame,
1934 	.wakeup         = gr_wakeup,
1935 	.pullup         = gr_pullup,
1936 	.udc_start	= gr_udc_start,
1937 	.udc_stop	= gr_udc_stop,
1938 	/* Other operations not supported */
1939 };
1940 
1941 /* ---------------------------------------------------------------------- */
1942 /* Module probe, removal and of-matching */
1943 
1944 static const char * const onames[] = {
1945 	"ep0out", "ep1out", "ep2out", "ep3out", "ep4out", "ep5out",
1946 	"ep6out", "ep7out", "ep8out", "ep9out", "ep10out", "ep11out",
1947 	"ep12out", "ep13out", "ep14out", "ep15out"
1948 };
1949 
1950 static const char * const inames[] = {
1951 	"ep0in", "ep1in", "ep2in", "ep3in", "ep4in", "ep5in",
1952 	"ep6in", "ep7in", "ep8in", "ep9in", "ep10in", "ep11in",
1953 	"ep12in", "ep13in", "ep14in", "ep15in"
1954 };
1955 
1956 /* Must be called with dev->lock held */
1957 static int gr_ep_init(struct gr_udc *dev, int num, int is_in, u32 maxplimit)
1958 {
1959 	struct gr_ep *ep;
1960 	struct gr_request *req;
1961 	struct usb_request *_req;
1962 	void *buf;
1963 
1964 	if (is_in) {
1965 		ep = &dev->epi[num];
1966 		ep->ep.name = inames[num];
1967 		ep->regs = &dev->regs->epi[num];
1968 	} else {
1969 		ep = &dev->epo[num];
1970 		ep->ep.name = onames[num];
1971 		ep->regs = &dev->regs->epo[num];
1972 	}
1973 
1974 	gr_ep_reset(ep);
1975 	ep->num = num;
1976 	ep->is_in = is_in;
1977 	ep->dev = dev;
1978 	ep->ep.ops = &gr_ep_ops;
1979 	INIT_LIST_HEAD(&ep->queue);
1980 
1981 	if (num == 0) {
1982 		_req = gr_alloc_request(&ep->ep, GFP_ATOMIC);
1983 		if (!_req)
1984 			return -ENOMEM;
1985 
1986 		buf = devm_kzalloc(dev->dev, PAGE_SIZE, GFP_DMA | GFP_ATOMIC);
1987 		if (!buf) {
1988 			gr_free_request(&ep->ep, _req);
1989 			return -ENOMEM;
1990 		}
1991 
1992 		req = container_of(_req, struct gr_request, req);
1993 		req->req.buf = buf;
1994 		req->req.length = MAX_CTRL_PL_SIZE;
1995 
1996 		if (is_in)
1997 			dev->ep0reqi = req; /* Complete gets set as used */
1998 		else
1999 			dev->ep0reqo = req; /* Completion treated separately */
2000 
2001 		usb_ep_set_maxpacket_limit(&ep->ep, MAX_CTRL_PL_SIZE);
2002 		ep->bytes_per_buffer = MAX_CTRL_PL_SIZE;
2003 
2004 		ep->ep.caps.type_control = true;
2005 	} else {
2006 		usb_ep_set_maxpacket_limit(&ep->ep, (u16)maxplimit);
2007 		list_add_tail(&ep->ep.ep_list, &dev->gadget.ep_list);
2008 
2009 		ep->ep.caps.type_iso = true;
2010 		ep->ep.caps.type_bulk = true;
2011 		ep->ep.caps.type_int = true;
2012 	}
2013 	list_add_tail(&ep->ep_list, &dev->ep_list);
2014 
2015 	if (is_in)
2016 		ep->ep.caps.dir_in = true;
2017 	else
2018 		ep->ep.caps.dir_out = true;
2019 
2020 	ep->tailbuf = dma_alloc_coherent(dev->dev, ep->ep.maxpacket_limit,
2021 					 &ep->tailbuf_paddr, GFP_ATOMIC);
2022 	if (!ep->tailbuf)
2023 		return -ENOMEM;
2024 
2025 	return 0;
2026 }
2027 
2028 /* Must be called with dev->lock held */
2029 static int gr_udc_init(struct gr_udc *dev)
2030 {
2031 	struct device_node *np = dev->dev->of_node;
2032 	u32 epctrl_val;
2033 	u32 dmactrl_val;
2034 	int i;
2035 	int ret = 0;
2036 	u32 bufsize;
2037 
2038 	gr_set_address(dev, 0);
2039 
2040 	INIT_LIST_HEAD(&dev->gadget.ep_list);
2041 	dev->gadget.speed = USB_SPEED_UNKNOWN;
2042 	dev->gadget.ep0 = &dev->epi[0].ep;
2043 
2044 	INIT_LIST_HEAD(&dev->ep_list);
2045 	gr_set_ep0state(dev, GR_EP0_DISCONNECT);
2046 
2047 	for (i = 0; i < dev->nepo; i++) {
2048 		if (of_property_read_u32_index(np, "epobufsizes", i, &bufsize))
2049 			bufsize = 1024;
2050 		ret = gr_ep_init(dev, i, 0, bufsize);
2051 		if (ret)
2052 			return ret;
2053 	}
2054 
2055 	for (i = 0; i < dev->nepi; i++) {
2056 		if (of_property_read_u32_index(np, "epibufsizes", i, &bufsize))
2057 			bufsize = 1024;
2058 		ret = gr_ep_init(dev, i, 1, bufsize);
2059 		if (ret)
2060 			return ret;
2061 	}
2062 
2063 	/* Must be disabled by default */
2064 	dev->remote_wakeup = 0;
2065 
2066 	/* Enable ep0out and ep0in */
2067 	epctrl_val = (MAX_CTRL_PL_SIZE << GR_EPCTRL_MAXPL_POS) | GR_EPCTRL_EV;
2068 	dmactrl_val = GR_DMACTRL_IE | GR_DMACTRL_AI;
2069 	gr_write32(&dev->epo[0].regs->epctrl, epctrl_val);
2070 	gr_write32(&dev->epi[0].regs->epctrl, epctrl_val | GR_EPCTRL_PI);
2071 	gr_write32(&dev->epo[0].regs->dmactrl, dmactrl_val);
2072 	gr_write32(&dev->epi[0].regs->dmactrl, dmactrl_val);
2073 
2074 	return 0;
2075 }
2076 
2077 static void gr_ep_remove(struct gr_udc *dev, int num, int is_in)
2078 {
2079 	struct gr_ep *ep;
2080 
2081 	if (is_in)
2082 		ep = &dev->epi[num];
2083 	else
2084 		ep = &dev->epo[num];
2085 
2086 	if (ep->tailbuf)
2087 		dma_free_coherent(dev->dev, ep->ep.maxpacket_limit,
2088 				  ep->tailbuf, ep->tailbuf_paddr);
2089 }
2090 
2091 static int gr_remove(struct platform_device *pdev)
2092 {
2093 	struct gr_udc *dev = platform_get_drvdata(pdev);
2094 	int i;
2095 
2096 	if (dev->added)
2097 		usb_del_gadget_udc(&dev->gadget); /* Shuts everything down */
2098 	if (dev->driver)
2099 		return -EBUSY;
2100 
2101 	gr_dfs_delete(dev);
2102 	dma_pool_destroy(dev->desc_pool);
2103 	platform_set_drvdata(pdev, NULL);
2104 
2105 	gr_free_request(&dev->epi[0].ep, &dev->ep0reqi->req);
2106 	gr_free_request(&dev->epo[0].ep, &dev->ep0reqo->req);
2107 
2108 	for (i = 0; i < dev->nepo; i++)
2109 		gr_ep_remove(dev, i, 0);
2110 	for (i = 0; i < dev->nepi; i++)
2111 		gr_ep_remove(dev, i, 1);
2112 
2113 	return 0;
2114 }
2115 static int gr_request_irq(struct gr_udc *dev, int irq)
2116 {
2117 	return devm_request_threaded_irq(dev->dev, irq, gr_irq, gr_irq_handler,
2118 					 IRQF_SHARED, driver_name, dev);
2119 }
2120 
2121 static int gr_probe(struct platform_device *pdev)
2122 {
2123 	struct gr_udc *dev;
2124 	struct gr_regs __iomem *regs;
2125 	int retval;
2126 	u32 status;
2127 
2128 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
2129 	if (!dev)
2130 		return -ENOMEM;
2131 	dev->dev = &pdev->dev;
2132 
2133 	regs = devm_platform_ioremap_resource(pdev, 0);
2134 	if (IS_ERR(regs))
2135 		return PTR_ERR(regs);
2136 
2137 	dev->irq = platform_get_irq(pdev, 0);
2138 	if (dev->irq <= 0)
2139 		return -ENODEV;
2140 
2141 	/* Some core configurations has separate irqs for IN and OUT events */
2142 	dev->irqi = platform_get_irq(pdev, 1);
2143 	if (dev->irqi > 0) {
2144 		dev->irqo = platform_get_irq(pdev, 2);
2145 		if (dev->irqo <= 0)
2146 			return -ENODEV;
2147 	} else {
2148 		dev->irqi = 0;
2149 	}
2150 
2151 	dev->gadget.name = driver_name;
2152 	dev->gadget.max_speed = USB_SPEED_HIGH;
2153 	dev->gadget.ops = &gr_ops;
2154 
2155 	spin_lock_init(&dev->lock);
2156 	dev->regs = regs;
2157 
2158 	platform_set_drvdata(pdev, dev);
2159 
2160 	/* Determine number of endpoints and data interface mode */
2161 	status = gr_read32(&dev->regs->status);
2162 	dev->nepi = ((status & GR_STATUS_NEPI_MASK) >> GR_STATUS_NEPI_POS) + 1;
2163 	dev->nepo = ((status & GR_STATUS_NEPO_MASK) >> GR_STATUS_NEPO_POS) + 1;
2164 
2165 	if (!(status & GR_STATUS_DM)) {
2166 		dev_err(dev->dev, "Slave mode cores are not supported\n");
2167 		return -ENODEV;
2168 	}
2169 
2170 	/* --- Effects of the following calls might need explicit cleanup --- */
2171 
2172 	/* Create DMA pool for descriptors */
2173 	dev->desc_pool = dma_pool_create("desc_pool", dev->dev,
2174 					 sizeof(struct gr_dma_desc), 4, 0);
2175 	if (!dev->desc_pool) {
2176 		dev_err(dev->dev, "Could not allocate DMA pool");
2177 		return -ENOMEM;
2178 	}
2179 
2180 	/* Inside lock so that no gadget can use this udc until probe is done */
2181 	retval = usb_add_gadget_udc(dev->dev, &dev->gadget);
2182 	if (retval) {
2183 		dev_err(dev->dev, "Could not add gadget udc");
2184 		goto out;
2185 	}
2186 	dev->added = 1;
2187 
2188 	spin_lock(&dev->lock);
2189 
2190 	retval = gr_udc_init(dev);
2191 	if (retval) {
2192 		spin_unlock(&dev->lock);
2193 		goto out;
2194 	}
2195 
2196 	/* Clear all interrupt enables that might be left on since last boot */
2197 	gr_disable_interrupts_and_pullup(dev);
2198 
2199 	spin_unlock(&dev->lock);
2200 
2201 	gr_dfs_create(dev);
2202 
2203 	retval = gr_request_irq(dev, dev->irq);
2204 	if (retval) {
2205 		dev_err(dev->dev, "Failed to request irq %d\n", dev->irq);
2206 		goto out;
2207 	}
2208 
2209 	if (dev->irqi) {
2210 		retval = gr_request_irq(dev, dev->irqi);
2211 		if (retval) {
2212 			dev_err(dev->dev, "Failed to request irqi %d\n",
2213 				dev->irqi);
2214 			goto out;
2215 		}
2216 		retval = gr_request_irq(dev, dev->irqo);
2217 		if (retval) {
2218 			dev_err(dev->dev, "Failed to request irqo %d\n",
2219 				dev->irqo);
2220 			goto out;
2221 		}
2222 	}
2223 
2224 	if (dev->irqi)
2225 		dev_info(dev->dev, "regs: %p, irqs %d, %d, %d\n", dev->regs,
2226 			 dev->irq, dev->irqi, dev->irqo);
2227 	else
2228 		dev_info(dev->dev, "regs: %p, irq %d\n", dev->regs, dev->irq);
2229 
2230 out:
2231 	if (retval)
2232 		gr_remove(pdev);
2233 
2234 	return retval;
2235 }
2236 
2237 static const struct of_device_id gr_match[] = {
2238 	{.name = "GAISLER_USBDC"},
2239 	{.name = "01_021"},
2240 	{},
2241 };
2242 MODULE_DEVICE_TABLE(of, gr_match);
2243 
2244 static struct platform_driver gr_driver = {
2245 	.driver = {
2246 		.name = DRIVER_NAME,
2247 		.of_match_table = gr_match,
2248 	},
2249 	.probe = gr_probe,
2250 	.remove = gr_remove,
2251 };
2252 module_platform_driver(gr_driver);
2253 
2254 MODULE_AUTHOR("Aeroflex Gaisler AB.");
2255 MODULE_DESCRIPTION(DRIVER_DESC);
2256 MODULE_LICENSE("GPL");
2257