1 /*
2 	Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
3 	Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
4 	<http://rt2x00.serialmonkey.com>
5 
6 	This program is free software; you can redistribute it and/or modify
7 	it under the terms of the GNU General Public License as published by
8 	the Free Software Foundation; either version 2 of the License, or
9 	(at your option) any later version.
10 
11 	This program is distributed in the hope that it will be useful,
12 	but WITHOUT ANY WARRANTY; without even the implied warranty of
13 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 	GNU General Public License for more details.
15 
16 	You should have received a copy of the GNU General Public License
17 	along with this program; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 /*
21 	Module: rt2x00usb
22 	Abstract: rt2x00 generic usb device routines.
23  */
24 
25 #include <linux/kernel.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/usb.h>
29 #include <linux/bug.h>
30 
31 #include "rt2x00.h"
32 #include "rt2x00usb.h"
33 
34 static bool rt2x00usb_check_usb_error(struct rt2x00_dev *rt2x00dev, int status)
35 {
36 	if (status == -ENODEV || status == -ENOENT)
37 		return true;
38 
39 	if (status == -EPROTO || status == -ETIMEDOUT)
40 		rt2x00dev->num_proto_errs++;
41 	else
42 		rt2x00dev->num_proto_errs = 0;
43 
44 	if (rt2x00dev->num_proto_errs > 3)
45 		return true;
46 
47 	return false;
48 }
49 
50 /*
51  * Interfacing with the HW.
52  */
53 int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
54 			     const u8 request, const u8 requesttype,
55 			     const u16 offset, const u16 value,
56 			     void *buffer, const u16 buffer_length,
57 			     const int timeout)
58 {
59 	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
60 	int status;
61 	unsigned int pipe =
62 	    (requesttype == USB_VENDOR_REQUEST_IN) ?
63 	    usb_rcvctrlpipe(usb_dev, 0) : usb_sndctrlpipe(usb_dev, 0);
64 	unsigned long expire = jiffies + msecs_to_jiffies(timeout);
65 
66 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
67 		return -ENODEV;
68 
69 	do {
70 		status = usb_control_msg(usb_dev, pipe, request, requesttype,
71 					 value, offset, buffer, buffer_length,
72 					 timeout / 2);
73 		if (status >= 0)
74 			return 0;
75 
76 		if (rt2x00usb_check_usb_error(rt2x00dev, status)) {
77 			/* Device has disappeared. */
78 			clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
79 			break;
80 		}
81 	} while (time_before(jiffies, expire));
82 
83 	rt2x00_err(rt2x00dev,
84 		   "Vendor Request 0x%02x failed for offset 0x%04x with error %d\n",
85 		   request, offset, status);
86 
87 	return status;
88 }
89 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request);
90 
91 int rt2x00usb_vendor_req_buff_lock(struct rt2x00_dev *rt2x00dev,
92 				   const u8 request, const u8 requesttype,
93 				   const u16 offset, void *buffer,
94 				   const u16 buffer_length, const int timeout)
95 {
96 	int status;
97 
98 	BUG_ON(!mutex_is_locked(&rt2x00dev->csr_mutex));
99 
100 	/*
101 	 * Check for Cache availability.
102 	 */
103 	if (unlikely(!rt2x00dev->csr.cache || buffer_length > CSR_CACHE_SIZE)) {
104 		rt2x00_err(rt2x00dev, "CSR cache not available\n");
105 		return -ENOMEM;
106 	}
107 
108 	if (requesttype == USB_VENDOR_REQUEST_OUT)
109 		memcpy(rt2x00dev->csr.cache, buffer, buffer_length);
110 
111 	status = rt2x00usb_vendor_request(rt2x00dev, request, requesttype,
112 					  offset, 0, rt2x00dev->csr.cache,
113 					  buffer_length, timeout);
114 
115 	if (!status && requesttype == USB_VENDOR_REQUEST_IN)
116 		memcpy(buffer, rt2x00dev->csr.cache, buffer_length);
117 
118 	return status;
119 }
120 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_req_buff_lock);
121 
122 int rt2x00usb_vendor_request_buff(struct rt2x00_dev *rt2x00dev,
123 				  const u8 request, const u8 requesttype,
124 				  const u16 offset, void *buffer,
125 				  const u16 buffer_length)
126 {
127 	int status = 0;
128 	unsigned char *tb;
129 	u16 off, len, bsize;
130 
131 	mutex_lock(&rt2x00dev->csr_mutex);
132 
133 	tb  = (char *)buffer;
134 	off = offset;
135 	len = buffer_length;
136 	while (len && !status) {
137 		bsize = min_t(u16, CSR_CACHE_SIZE, len);
138 		status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
139 							requesttype, off, tb,
140 							bsize, REGISTER_TIMEOUT);
141 
142 		tb  += bsize;
143 		len -= bsize;
144 		off += bsize;
145 	}
146 
147 	mutex_unlock(&rt2x00dev->csr_mutex);
148 
149 	return status;
150 }
151 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);
152 
153 int rt2x00usb_regbusy_read(struct rt2x00_dev *rt2x00dev,
154 			   const unsigned int offset,
155 			   const struct rt2x00_field32 field,
156 			   u32 *reg)
157 {
158 	unsigned int i;
159 
160 	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
161 		return -ENODEV;
162 
163 	for (i = 0; i < REGISTER_USB_BUSY_COUNT; i++) {
164 		*reg = rt2x00usb_register_read_lock(rt2x00dev, offset);
165 		if (!rt2x00_get_field32(*reg, field))
166 			return 1;
167 		udelay(REGISTER_BUSY_DELAY);
168 	}
169 
170 	rt2x00_err(rt2x00dev, "Indirect register access failed: offset=0x%.08x, value=0x%.08x\n",
171 		   offset, *reg);
172 	*reg = ~0;
173 
174 	return 0;
175 }
176 EXPORT_SYMBOL_GPL(rt2x00usb_regbusy_read);
177 
178 
179 struct rt2x00_async_read_data {
180 	__le32 reg;
181 	struct usb_ctrlrequest cr;
182 	struct rt2x00_dev *rt2x00dev;
183 	bool (*callback)(struct rt2x00_dev *, int, u32);
184 };
185 
186 static void rt2x00usb_register_read_async_cb(struct urb *urb)
187 {
188 	struct rt2x00_async_read_data *rd = urb->context;
189 	if (rd->callback(rd->rt2x00dev, urb->status, le32_to_cpu(rd->reg))) {
190 		usb_anchor_urb(urb, rd->rt2x00dev->anchor);
191 		if (usb_submit_urb(urb, GFP_ATOMIC) < 0) {
192 			usb_unanchor_urb(urb);
193 			kfree(rd);
194 		}
195 	} else
196 		kfree(rd);
197 }
198 
199 void rt2x00usb_register_read_async(struct rt2x00_dev *rt2x00dev,
200 				   const unsigned int offset,
201 				   bool (*callback)(struct rt2x00_dev*, int, u32))
202 {
203 	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
204 	struct urb *urb;
205 	struct rt2x00_async_read_data *rd;
206 
207 	rd = kmalloc(sizeof(*rd), GFP_ATOMIC);
208 	if (!rd)
209 		return;
210 
211 	urb = usb_alloc_urb(0, GFP_ATOMIC);
212 	if (!urb) {
213 		kfree(rd);
214 		return;
215 	}
216 
217 	rd->rt2x00dev = rt2x00dev;
218 	rd->callback = callback;
219 	rd->cr.bRequestType = USB_VENDOR_REQUEST_IN;
220 	rd->cr.bRequest = USB_MULTI_READ;
221 	rd->cr.wValue = 0;
222 	rd->cr.wIndex = cpu_to_le16(offset);
223 	rd->cr.wLength = cpu_to_le16(sizeof(u32));
224 
225 	usb_fill_control_urb(urb, usb_dev, usb_rcvctrlpipe(usb_dev, 0),
226 			     (unsigned char *)(&rd->cr), &rd->reg, sizeof(rd->reg),
227 			     rt2x00usb_register_read_async_cb, rd);
228 	usb_anchor_urb(urb, rt2x00dev->anchor);
229 	if (usb_submit_urb(urb, GFP_ATOMIC) < 0) {
230 		usb_unanchor_urb(urb);
231 		kfree(rd);
232 	}
233 	usb_free_urb(urb);
234 }
235 EXPORT_SYMBOL_GPL(rt2x00usb_register_read_async);
236 
237 /*
238  * TX data handlers.
239  */
240 static void rt2x00usb_work_txdone_entry(struct queue_entry *entry)
241 {
242 	/*
243 	 * If the transfer to hardware succeeded, it does not mean the
244 	 * frame was send out correctly. It only means the frame
245 	 * was successfully pushed to the hardware, we have no
246 	 * way to determine the transmission status right now.
247 	 * (Only indirectly by looking at the failed TX counters
248 	 * in the register).
249 	 */
250 	if (test_bit(ENTRY_DATA_IO_FAILED, &entry->flags))
251 		rt2x00lib_txdone_noinfo(entry, TXDONE_FAILURE);
252 	else
253 		rt2x00lib_txdone_noinfo(entry, TXDONE_UNKNOWN);
254 }
255 
256 static void rt2x00usb_work_txdone(struct work_struct *work)
257 {
258 	struct rt2x00_dev *rt2x00dev =
259 	    container_of(work, struct rt2x00_dev, txdone_work);
260 	struct data_queue *queue;
261 	struct queue_entry *entry;
262 
263 	tx_queue_for_each(rt2x00dev, queue) {
264 		while (!rt2x00queue_empty(queue)) {
265 			entry = rt2x00queue_get_entry(queue, Q_INDEX_DONE);
266 
267 			if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) ||
268 			    !test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
269 				break;
270 
271 			rt2x00usb_work_txdone_entry(entry);
272 		}
273 	}
274 }
275 
276 static void rt2x00usb_interrupt_txdone(struct urb *urb)
277 {
278 	struct queue_entry *entry = (struct queue_entry *)urb->context;
279 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
280 
281 	if (!test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
282 		return;
283 	/*
284 	 * Check if the frame was correctly uploaded
285 	 */
286 	if (urb->status)
287 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
288 	/*
289 	 * Report the frame as DMA done
290 	 */
291 	rt2x00lib_dmadone(entry);
292 
293 	if (rt2x00dev->ops->lib->tx_dma_done)
294 		rt2x00dev->ops->lib->tx_dma_done(entry);
295 	/*
296 	 * Schedule the delayed work for reading the TX status
297 	 * from the device.
298 	 */
299 	if (!rt2x00_has_cap_flag(rt2x00dev, REQUIRE_TXSTATUS_FIFO) ||
300 	    !kfifo_is_empty(&rt2x00dev->txstatus_fifo))
301 		queue_work(rt2x00dev->workqueue, &rt2x00dev->txdone_work);
302 }
303 
304 static bool rt2x00usb_kick_tx_entry(struct queue_entry *entry, void *data)
305 {
306 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
307 	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
308 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
309 	u32 length;
310 	int status;
311 
312 	if (!test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags) ||
313 	    test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
314 		return false;
315 
316 	/*
317 	 * USB devices require certain padding at the end of each frame
318 	 * and urb. Those paddings are not included in skbs. Pass entry
319 	 * to the driver to determine what the overall length should be.
320 	 */
321 	length = rt2x00dev->ops->lib->get_tx_data_len(entry);
322 
323 	status = skb_padto(entry->skb, length);
324 	if (unlikely(status)) {
325 		/* TODO: report something more appropriate than IO_FAILED. */
326 		rt2x00_warn(rt2x00dev, "TX SKB padding error, out of memory\n");
327 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
328 		rt2x00lib_dmadone(entry);
329 
330 		return false;
331 	}
332 
333 	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
334 			  usb_sndbulkpipe(usb_dev, entry->queue->usb_endpoint),
335 			  entry->skb->data, length,
336 			  rt2x00usb_interrupt_txdone, entry);
337 
338 	status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
339 	if (status) {
340 		if (rt2x00usb_check_usb_error(rt2x00dev, status))
341 			clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
342 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
343 		rt2x00lib_dmadone(entry);
344 	}
345 
346 	return false;
347 }
348 
349 /*
350  * RX data handlers.
351  */
352 static void rt2x00usb_work_rxdone(struct work_struct *work)
353 {
354 	struct rt2x00_dev *rt2x00dev =
355 	    container_of(work, struct rt2x00_dev, rxdone_work);
356 	struct queue_entry *entry;
357 	struct skb_frame_desc *skbdesc;
358 	u8 rxd[32];
359 
360 	while (!rt2x00queue_empty(rt2x00dev->rx)) {
361 		entry = rt2x00queue_get_entry(rt2x00dev->rx, Q_INDEX_DONE);
362 
363 		if (test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) ||
364 		    !test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
365 			break;
366 
367 		/*
368 		 * Fill in desc fields of the skb descriptor
369 		 */
370 		skbdesc = get_skb_frame_desc(entry->skb);
371 		skbdesc->desc = rxd;
372 		skbdesc->desc_len = entry->queue->desc_size;
373 
374 		/*
375 		 * Send the frame to rt2x00lib for further processing.
376 		 */
377 		rt2x00lib_rxdone(entry, GFP_KERNEL);
378 	}
379 }
380 
381 static void rt2x00usb_interrupt_rxdone(struct urb *urb)
382 {
383 	struct queue_entry *entry = (struct queue_entry *)urb->context;
384 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
385 
386 	if (!test_and_clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
387 		return;
388 
389 	/*
390 	 * Report the frame as DMA done
391 	 */
392 	rt2x00lib_dmadone(entry);
393 
394 	/*
395 	 * Check if the received data is simply too small
396 	 * to be actually valid, or if the urb is signaling
397 	 * a problem.
398 	 */
399 	if (urb->actual_length < entry->queue->desc_size || urb->status)
400 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
401 
402 	/*
403 	 * Schedule the delayed work for reading the RX status
404 	 * from the device.
405 	 */
406 	queue_work(rt2x00dev->workqueue, &rt2x00dev->rxdone_work);
407 }
408 
409 static bool rt2x00usb_kick_rx_entry(struct queue_entry *entry, void *data)
410 {
411 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
412 	struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
413 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
414 	int status;
415 
416 	if (test_and_set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags) ||
417 	    test_bit(ENTRY_DATA_STATUS_PENDING, &entry->flags))
418 		return false;
419 
420 	rt2x00lib_dmastart(entry);
421 
422 	usb_fill_bulk_urb(entry_priv->urb, usb_dev,
423 			  usb_rcvbulkpipe(usb_dev, entry->queue->usb_endpoint),
424 			  entry->skb->data, entry->skb->len,
425 			  rt2x00usb_interrupt_rxdone, entry);
426 
427 	status = usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
428 	if (status) {
429 		if (rt2x00usb_check_usb_error(rt2x00dev, status))
430 			clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
431 		set_bit(ENTRY_DATA_IO_FAILED, &entry->flags);
432 		rt2x00lib_dmadone(entry);
433 	}
434 
435 	return false;
436 }
437 
438 void rt2x00usb_kick_queue(struct data_queue *queue)
439 {
440 	switch (queue->qid) {
441 	case QID_AC_VO:
442 	case QID_AC_VI:
443 	case QID_AC_BE:
444 	case QID_AC_BK:
445 		if (!rt2x00queue_empty(queue))
446 			rt2x00queue_for_each_entry(queue,
447 						   Q_INDEX_DONE,
448 						   Q_INDEX,
449 						   NULL,
450 						   rt2x00usb_kick_tx_entry);
451 		break;
452 	case QID_RX:
453 		if (!rt2x00queue_full(queue))
454 			rt2x00queue_for_each_entry(queue,
455 						   Q_INDEX,
456 						   Q_INDEX_DONE,
457 						   NULL,
458 						   rt2x00usb_kick_rx_entry);
459 		break;
460 	default:
461 		break;
462 	}
463 }
464 EXPORT_SYMBOL_GPL(rt2x00usb_kick_queue);
465 
466 static bool rt2x00usb_flush_entry(struct queue_entry *entry, void *data)
467 {
468 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
469 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
470 	struct queue_entry_priv_usb_bcn *bcn_priv = entry->priv_data;
471 
472 	if (!test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
473 		return false;
474 
475 	usb_kill_urb(entry_priv->urb);
476 
477 	/*
478 	 * Kill guardian urb (if required by driver).
479 	 */
480 	if ((entry->queue->qid == QID_BEACON) &&
481 	    (rt2x00_has_cap_flag(rt2x00dev, REQUIRE_BEACON_GUARD)))
482 		usb_kill_urb(bcn_priv->guardian_urb);
483 
484 	return false;
485 }
486 
487 void rt2x00usb_flush_queue(struct data_queue *queue, bool drop)
488 {
489 	struct work_struct *completion;
490 	unsigned int i;
491 
492 	if (drop)
493 		rt2x00queue_for_each_entry(queue, Q_INDEX_DONE, Q_INDEX, NULL,
494 					   rt2x00usb_flush_entry);
495 
496 	/*
497 	 * Obtain the queue completion handler
498 	 */
499 	switch (queue->qid) {
500 	case QID_AC_VO:
501 	case QID_AC_VI:
502 	case QID_AC_BE:
503 	case QID_AC_BK:
504 		completion = &queue->rt2x00dev->txdone_work;
505 		break;
506 	case QID_RX:
507 		completion = &queue->rt2x00dev->rxdone_work;
508 		break;
509 	default:
510 		return;
511 	}
512 
513 	for (i = 0; i < 10; i++) {
514 		/*
515 		 * Check if the driver is already done, otherwise we
516 		 * have to sleep a little while to give the driver/hw
517 		 * the oppurtunity to complete interrupt process itself.
518 		 */
519 		if (rt2x00queue_empty(queue))
520 			break;
521 
522 		/*
523 		 * Schedule the completion handler manually, when this
524 		 * worker function runs, it should cleanup the queue.
525 		 */
526 		queue_work(queue->rt2x00dev->workqueue, completion);
527 
528 		/*
529 		 * Wait for a little while to give the driver
530 		 * the oppurtunity to recover itself.
531 		 */
532 		msleep(50);
533 	}
534 }
535 EXPORT_SYMBOL_GPL(rt2x00usb_flush_queue);
536 
537 static void rt2x00usb_watchdog_tx_dma(struct data_queue *queue)
538 {
539 	rt2x00_warn(queue->rt2x00dev, "TX queue %d DMA timed out, invoke forced forced reset\n",
540 		    queue->qid);
541 
542 	rt2x00queue_stop_queue(queue);
543 	rt2x00queue_flush_queue(queue, true);
544 	rt2x00queue_start_queue(queue);
545 }
546 
547 static int rt2x00usb_dma_timeout(struct data_queue *queue)
548 {
549 	struct queue_entry *entry;
550 
551 	entry = rt2x00queue_get_entry(queue, Q_INDEX_DMA_DONE);
552 	return rt2x00queue_dma_timeout(entry);
553 }
554 
555 void rt2x00usb_watchdog(struct rt2x00_dev *rt2x00dev)
556 {
557 	struct data_queue *queue;
558 
559 	tx_queue_for_each(rt2x00dev, queue) {
560 		if (!rt2x00queue_empty(queue)) {
561 			if (rt2x00usb_dma_timeout(queue))
562 				rt2x00usb_watchdog_tx_dma(queue);
563 		}
564 	}
565 }
566 EXPORT_SYMBOL_GPL(rt2x00usb_watchdog);
567 
568 /*
569  * Radio handlers
570  */
571 void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
572 {
573 	rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
574 				    REGISTER_TIMEOUT);
575 }
576 EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);
577 
578 /*
579  * Device initialization handlers.
580  */
581 void rt2x00usb_clear_entry(struct queue_entry *entry)
582 {
583 	entry->flags = 0;
584 
585 	if (entry->queue->qid == QID_RX)
586 		rt2x00usb_kick_rx_entry(entry, NULL);
587 }
588 EXPORT_SYMBOL_GPL(rt2x00usb_clear_entry);
589 
590 static void rt2x00usb_assign_endpoint(struct data_queue *queue,
591 				      struct usb_endpoint_descriptor *ep_desc)
592 {
593 	struct usb_device *usb_dev = to_usb_device_intf(queue->rt2x00dev->dev);
594 	int pipe;
595 
596 	queue->usb_endpoint = usb_endpoint_num(ep_desc);
597 
598 	if (queue->qid == QID_RX) {
599 		pipe = usb_rcvbulkpipe(usb_dev, queue->usb_endpoint);
600 		queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 0);
601 	} else {
602 		pipe = usb_sndbulkpipe(usb_dev, queue->usb_endpoint);
603 		queue->usb_maxpacket = usb_maxpacket(usb_dev, pipe, 1);
604 	}
605 
606 	if (!queue->usb_maxpacket)
607 		queue->usb_maxpacket = 1;
608 }
609 
610 static int rt2x00usb_find_endpoints(struct rt2x00_dev *rt2x00dev)
611 {
612 	struct usb_interface *intf = to_usb_interface(rt2x00dev->dev);
613 	struct usb_host_interface *intf_desc = intf->cur_altsetting;
614 	struct usb_endpoint_descriptor *ep_desc;
615 	struct data_queue *queue = rt2x00dev->tx;
616 	struct usb_endpoint_descriptor *tx_ep_desc = NULL;
617 	unsigned int i;
618 
619 	/*
620 	 * Walk through all available endpoints to search for "bulk in"
621 	 * and "bulk out" endpoints. When we find such endpoints collect
622 	 * the information we need from the descriptor and assign it
623 	 * to the queue.
624 	 */
625 	for (i = 0; i < intf_desc->desc.bNumEndpoints; i++) {
626 		ep_desc = &intf_desc->endpoint[i].desc;
627 
628 		if (usb_endpoint_is_bulk_in(ep_desc)) {
629 			rt2x00usb_assign_endpoint(rt2x00dev->rx, ep_desc);
630 		} else if (usb_endpoint_is_bulk_out(ep_desc) &&
631 			   (queue != queue_end(rt2x00dev))) {
632 			rt2x00usb_assign_endpoint(queue, ep_desc);
633 			queue = queue_next(queue);
634 
635 			tx_ep_desc = ep_desc;
636 		}
637 	}
638 
639 	/*
640 	 * At least 1 endpoint for RX and 1 endpoint for TX must be available.
641 	 */
642 	if (!rt2x00dev->rx->usb_endpoint || !rt2x00dev->tx->usb_endpoint) {
643 		rt2x00_err(rt2x00dev, "Bulk-in/Bulk-out endpoints not found\n");
644 		return -EPIPE;
645 	}
646 
647 	/*
648 	 * It might be possible not all queues have a dedicated endpoint.
649 	 * Loop through all TX queues and copy the endpoint information
650 	 * which we have gathered from already assigned endpoints.
651 	 */
652 	txall_queue_for_each(rt2x00dev, queue) {
653 		if (!queue->usb_endpoint)
654 			rt2x00usb_assign_endpoint(queue, tx_ep_desc);
655 	}
656 
657 	return 0;
658 }
659 
660 static int rt2x00usb_alloc_entries(struct data_queue *queue)
661 {
662 	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
663 	struct queue_entry_priv_usb *entry_priv;
664 	struct queue_entry_priv_usb_bcn *bcn_priv;
665 	unsigned int i;
666 
667 	for (i = 0; i < queue->limit; i++) {
668 		entry_priv = queue->entries[i].priv_data;
669 		entry_priv->urb = usb_alloc_urb(0, GFP_KERNEL);
670 		if (!entry_priv->urb)
671 			return -ENOMEM;
672 	}
673 
674 	/*
675 	 * If this is not the beacon queue or
676 	 * no guardian byte was required for the beacon,
677 	 * then we are done.
678 	 */
679 	if (queue->qid != QID_BEACON ||
680 	    !rt2x00_has_cap_flag(rt2x00dev, REQUIRE_BEACON_GUARD))
681 		return 0;
682 
683 	for (i = 0; i < queue->limit; i++) {
684 		bcn_priv = queue->entries[i].priv_data;
685 		bcn_priv->guardian_urb = usb_alloc_urb(0, GFP_KERNEL);
686 		if (!bcn_priv->guardian_urb)
687 			return -ENOMEM;
688 	}
689 
690 	return 0;
691 }
692 
693 static void rt2x00usb_free_entries(struct data_queue *queue)
694 {
695 	struct rt2x00_dev *rt2x00dev = queue->rt2x00dev;
696 	struct queue_entry_priv_usb *entry_priv;
697 	struct queue_entry_priv_usb_bcn *bcn_priv;
698 	unsigned int i;
699 
700 	if (!queue->entries)
701 		return;
702 
703 	for (i = 0; i < queue->limit; i++) {
704 		entry_priv = queue->entries[i].priv_data;
705 		usb_kill_urb(entry_priv->urb);
706 		usb_free_urb(entry_priv->urb);
707 	}
708 
709 	/*
710 	 * If this is not the beacon queue or
711 	 * no guardian byte was required for the beacon,
712 	 * then we are done.
713 	 */
714 	if (queue->qid != QID_BEACON ||
715 	    !rt2x00_has_cap_flag(rt2x00dev, REQUIRE_BEACON_GUARD))
716 		return;
717 
718 	for (i = 0; i < queue->limit; i++) {
719 		bcn_priv = queue->entries[i].priv_data;
720 		usb_kill_urb(bcn_priv->guardian_urb);
721 		usb_free_urb(bcn_priv->guardian_urb);
722 	}
723 }
724 
725 int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
726 {
727 	struct data_queue *queue;
728 	int status;
729 
730 	/*
731 	 * Find endpoints for each queue
732 	 */
733 	status = rt2x00usb_find_endpoints(rt2x00dev);
734 	if (status)
735 		goto exit;
736 
737 	/*
738 	 * Allocate DMA
739 	 */
740 	queue_for_each(rt2x00dev, queue) {
741 		status = rt2x00usb_alloc_entries(queue);
742 		if (status)
743 			goto exit;
744 	}
745 
746 	return 0;
747 
748 exit:
749 	rt2x00usb_uninitialize(rt2x00dev);
750 
751 	return status;
752 }
753 EXPORT_SYMBOL_GPL(rt2x00usb_initialize);
754 
755 void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
756 {
757 	struct data_queue *queue;
758 
759 	usb_kill_anchored_urbs(rt2x00dev->anchor);
760 	hrtimer_cancel(&rt2x00dev->txstatus_timer);
761 	cancel_work_sync(&rt2x00dev->rxdone_work);
762 	cancel_work_sync(&rt2x00dev->txdone_work);
763 
764 	queue_for_each(rt2x00dev, queue)
765 		rt2x00usb_free_entries(queue);
766 }
767 EXPORT_SYMBOL_GPL(rt2x00usb_uninitialize);
768 
769 /*
770  * USB driver handlers.
771  */
772 static void rt2x00usb_free_reg(struct rt2x00_dev *rt2x00dev)
773 {
774 	kfree(rt2x00dev->rf);
775 	rt2x00dev->rf = NULL;
776 
777 	kfree(rt2x00dev->eeprom);
778 	rt2x00dev->eeprom = NULL;
779 
780 	kfree(rt2x00dev->csr.cache);
781 	rt2x00dev->csr.cache = NULL;
782 }
783 
784 static int rt2x00usb_alloc_reg(struct rt2x00_dev *rt2x00dev)
785 {
786 	rt2x00dev->csr.cache = kzalloc(CSR_CACHE_SIZE, GFP_KERNEL);
787 	if (!rt2x00dev->csr.cache)
788 		goto exit;
789 
790 	rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);
791 	if (!rt2x00dev->eeprom)
792 		goto exit;
793 
794 	rt2x00dev->rf = kzalloc(rt2x00dev->ops->rf_size, GFP_KERNEL);
795 	if (!rt2x00dev->rf)
796 		goto exit;
797 
798 	return 0;
799 
800 exit:
801 	rt2x00_probe_err("Failed to allocate registers\n");
802 
803 	rt2x00usb_free_reg(rt2x00dev);
804 
805 	return -ENOMEM;
806 }
807 
808 int rt2x00usb_probe(struct usb_interface *usb_intf,
809 		    const struct rt2x00_ops *ops)
810 {
811 	struct usb_device *usb_dev = interface_to_usbdev(usb_intf);
812 	struct ieee80211_hw *hw;
813 	struct rt2x00_dev *rt2x00dev;
814 	int retval;
815 
816 	usb_dev = usb_get_dev(usb_dev);
817 	usb_reset_device(usb_dev);
818 
819 	hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
820 	if (!hw) {
821 		rt2x00_probe_err("Failed to allocate hardware\n");
822 		retval = -ENOMEM;
823 		goto exit_put_device;
824 	}
825 
826 	usb_set_intfdata(usb_intf, hw);
827 
828 	rt2x00dev = hw->priv;
829 	rt2x00dev->dev = &usb_intf->dev;
830 	rt2x00dev->ops = ops;
831 	rt2x00dev->hw = hw;
832 
833 	rt2x00_set_chip_intf(rt2x00dev, RT2X00_CHIP_INTF_USB);
834 
835 	INIT_WORK(&rt2x00dev->rxdone_work, rt2x00usb_work_rxdone);
836 	INIT_WORK(&rt2x00dev->txdone_work, rt2x00usb_work_txdone);
837 	hrtimer_init(&rt2x00dev->txstatus_timer, CLOCK_MONOTONIC,
838 		     HRTIMER_MODE_REL);
839 
840 	retval = rt2x00usb_alloc_reg(rt2x00dev);
841 	if (retval)
842 		goto exit_free_device;
843 
844 	rt2x00dev->anchor = devm_kmalloc(&usb_dev->dev,
845 					sizeof(struct usb_anchor),
846 					GFP_KERNEL);
847 	if (!rt2x00dev->anchor) {
848 		retval = -ENOMEM;
849 		goto exit_free_reg;
850 	}
851 	init_usb_anchor(rt2x00dev->anchor);
852 
853 	retval = rt2x00lib_probe_dev(rt2x00dev);
854 	if (retval)
855 		goto exit_free_anchor;
856 
857 	return 0;
858 
859 exit_free_anchor:
860 	usb_kill_anchored_urbs(rt2x00dev->anchor);
861 
862 exit_free_reg:
863 	rt2x00usb_free_reg(rt2x00dev);
864 
865 exit_free_device:
866 	ieee80211_free_hw(hw);
867 
868 exit_put_device:
869 	usb_put_dev(usb_dev);
870 
871 	usb_set_intfdata(usb_intf, NULL);
872 
873 	return retval;
874 }
875 EXPORT_SYMBOL_GPL(rt2x00usb_probe);
876 
877 void rt2x00usb_disconnect(struct usb_interface *usb_intf)
878 {
879 	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
880 	struct rt2x00_dev *rt2x00dev = hw->priv;
881 
882 	/*
883 	 * Free all allocated data.
884 	 */
885 	rt2x00lib_remove_dev(rt2x00dev);
886 	rt2x00usb_free_reg(rt2x00dev);
887 	ieee80211_free_hw(hw);
888 
889 	/*
890 	 * Free the USB device data.
891 	 */
892 	usb_set_intfdata(usb_intf, NULL);
893 	usb_put_dev(interface_to_usbdev(usb_intf));
894 }
895 EXPORT_SYMBOL_GPL(rt2x00usb_disconnect);
896 
897 #ifdef CONFIG_PM
898 int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
899 {
900 	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
901 	struct rt2x00_dev *rt2x00dev = hw->priv;
902 
903 	return rt2x00lib_suspend(rt2x00dev, state);
904 }
905 EXPORT_SYMBOL_GPL(rt2x00usb_suspend);
906 
907 int rt2x00usb_resume(struct usb_interface *usb_intf)
908 {
909 	struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
910 	struct rt2x00_dev *rt2x00dev = hw->priv;
911 
912 	return rt2x00lib_resume(rt2x00dev);
913 }
914 EXPORT_SYMBOL_GPL(rt2x00usb_resume);
915 #endif /* CONFIG_PM */
916 
917 /*
918  * rt2x00usb module information.
919  */
920 MODULE_AUTHOR(DRV_PROJECT);
921 MODULE_VERSION(DRV_VERSION);
922 MODULE_DESCRIPTION("rt2x00 usb library");
923 MODULE_LICENSE("GPL");
924