rt2x00: Fix race condition when using inderect registers
[linux-2.6/btrfs-unstable.git] / drivers / net / wireless / rt2x00 / rt2x00usb.c
blobc507b0d9409ffbf4d18fa0d964632a491a1548b5
1 /*
2 Copyright (C) 2004 - 2008 rt2x00 SourceForge Project
3 <http://rt2x00.serialmonkey.com>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the
17 Free Software Foundation, Inc.,
18 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 Module: rt2x00usb
23 Abstract: rt2x00 generic usb device routines.
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/usb.h>
29 #include <linux/bug.h>
31 #include "rt2x00.h"
32 #include "rt2x00usb.h"
35 * Interfacing with the HW.
37 int rt2x00usb_vendor_request(struct rt2x00_dev *rt2x00dev,
38 const u8 request, const u8 requesttype,
39 const u16 offset, const u16 value,
40 void *buffer, const u16 buffer_length,
41 const int timeout)
43 struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
44 int status;
45 unsigned int i;
46 unsigned int pipe =
47 (requesttype == USB_VENDOR_REQUEST_IN) ?
48 usb_rcvctrlpipe(usb_dev, 0) : usb_sndctrlpipe(usb_dev, 0);
51 for (i = 0; i < REGISTER_BUSY_COUNT; i++) {
52 status = usb_control_msg(usb_dev, pipe, request, requesttype,
53 value, offset, buffer, buffer_length,
54 timeout);
55 if (status >= 0)
56 return 0;
59 * Check for errors
60 * -ENODEV: Device has disappeared, no point continuing.
61 * All other errors: Try again.
63 else if (status == -ENODEV)
64 break;
67 ERROR(rt2x00dev,
68 "Vendor Request 0x%02x failed for offset 0x%04x with error %d.\n",
69 request, offset, status);
71 return status;
73 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request);
75 int rt2x00usb_vendor_req_buff_lock(struct rt2x00_dev *rt2x00dev,
76 const u8 request, const u8 requesttype,
77 const u16 offset, void *buffer,
78 const u16 buffer_length, const int timeout)
80 int status;
82 BUG_ON(!mutex_is_locked(&rt2x00dev->csr_mutex));
85 * Check for Cache availability.
87 if (unlikely(!rt2x00dev->csr.cache || buffer_length > CSR_CACHE_SIZE)) {
88 ERROR(rt2x00dev, "CSR cache not available.\n");
89 return -ENOMEM;
92 if (requesttype == USB_VENDOR_REQUEST_OUT)
93 memcpy(rt2x00dev->csr.cache, buffer, buffer_length);
95 status = rt2x00usb_vendor_request(rt2x00dev, request, requesttype,
96 offset, 0, rt2x00dev->csr.cache,
97 buffer_length, timeout);
99 if (!status && requesttype == USB_VENDOR_REQUEST_IN)
100 memcpy(buffer, rt2x00dev->csr.cache, buffer_length);
102 return status;
104 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_req_buff_lock);
106 int rt2x00usb_vendor_request_buff(struct rt2x00_dev *rt2x00dev,
107 const u8 request, const u8 requesttype,
108 const u16 offset, void *buffer,
109 const u16 buffer_length, const int timeout)
111 int status;
113 mutex_lock(&rt2x00dev->csr_mutex);
115 status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
116 requesttype, offset, buffer,
117 buffer_length, timeout);
119 mutex_unlock(&rt2x00dev->csr_mutex);
121 return status;
123 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_buff);
125 int rt2x00usb_vendor_request_large_buff(struct rt2x00_dev *rt2x00dev,
126 const u8 request, const u8 requesttype,
127 const u16 offset, const void *buffer,
128 const u16 buffer_length,
129 const int timeout)
131 int status = 0;
132 unsigned char *tb;
133 u16 off, len, bsize;
135 mutex_lock(&rt2x00dev->csr_mutex);
137 tb = (char *)buffer;
138 off = offset;
139 len = buffer_length;
140 while (len && !status) {
141 bsize = min_t(u16, CSR_CACHE_SIZE, len);
142 status = rt2x00usb_vendor_req_buff_lock(rt2x00dev, request,
143 requesttype, off, tb,
144 bsize, timeout);
146 tb += bsize;
147 len -= bsize;
148 off += bsize;
151 mutex_unlock(&rt2x00dev->csr_mutex);
153 return status;
155 EXPORT_SYMBOL_GPL(rt2x00usb_vendor_request_large_buff);
158 * TX data handlers.
160 static void rt2x00usb_interrupt_txdone(struct urb *urb)
162 struct queue_entry *entry = (struct queue_entry *)urb->context;
163 struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
164 struct txdone_entry_desc txdesc;
166 if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
167 !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
168 return;
171 * Obtain the status about this packet.
172 * Note that when the status is 0 it does not mean the
173 * frame was send out correctly. It only means the frame
174 * was succesfully pushed to the hardware, we have no
175 * way to determine the transmission status right now.
176 * (Only indirectly by looking at the failed TX counters
177 * in the register).
179 txdesc.flags = 0;
180 if (!urb->status)
181 __set_bit(TXDONE_UNKNOWN, &txdesc.flags);
182 else
183 __set_bit(TXDONE_FAILURE, &txdesc.flags);
184 txdesc.retry = 0;
186 rt2x00lib_txdone(entry, &txdesc);
189 int rt2x00usb_write_tx_data(struct queue_entry *entry)
191 struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
192 struct usb_device *usb_dev = to_usb_device_intf(rt2x00dev->dev);
193 struct queue_entry_priv_usb *entry_priv = entry->priv_data;
194 struct skb_frame_desc *skbdesc;
195 u32 length;
198 * Add the descriptor in front of the skb.
200 skb_push(entry->skb, entry->queue->desc_size);
201 memset(entry->skb->data, 0, entry->queue->desc_size);
204 * Fill in skb descriptor
206 skbdesc = get_skb_frame_desc(entry->skb);
207 skbdesc->desc = entry->skb->data;
208 skbdesc->desc_len = entry->queue->desc_size;
211 * USB devices cannot blindly pass the skb->len as the
212 * length of the data to usb_fill_bulk_urb. Pass the skb
213 * to the driver to determine what the length should be.
215 length = rt2x00dev->ops->lib->get_tx_data_len(rt2x00dev, entry->skb);
217 usb_fill_bulk_urb(entry_priv->urb, usb_dev,
218 usb_sndbulkpipe(usb_dev, 1),
219 entry->skb->data, length,
220 rt2x00usb_interrupt_txdone, entry);
223 * Make sure the skb->data pointer points to the frame, not the
224 * descriptor.
226 skb_pull(entry->skb, entry->queue->desc_size);
228 return 0;
230 EXPORT_SYMBOL_GPL(rt2x00usb_write_tx_data);
232 static inline void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
234 struct queue_entry_priv_usb *entry_priv = entry->priv_data;
236 if (test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
237 usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
240 void rt2x00usb_kick_tx_queue(struct rt2x00_dev *rt2x00dev,
241 const enum data_queue_qid qid)
243 struct data_queue *queue = rt2x00queue_get_queue(rt2x00dev, qid);
244 unsigned long irqflags;
245 unsigned int index;
246 unsigned int index_done;
247 unsigned int i;
250 * Only protect the range we are going to loop over,
251 * if during our loop a extra entry is set to pending
252 * it should not be kicked during this run, since it
253 * is part of another TX operation.
255 spin_lock_irqsave(&queue->lock, irqflags);
256 index = queue->index[Q_INDEX];
257 index_done = queue->index[Q_INDEX_DONE];
258 spin_unlock_irqrestore(&queue->lock, irqflags);
261 * Start from the TX done pointer, this guarentees that we will
262 * send out all frames in the correct order.
264 if (index_done < index) {
265 for (i = index_done; i < index; i++)
266 rt2x00usb_kick_tx_entry(&queue->entries[i]);
267 } else {
268 for (i = index_done; i < queue->limit; i++)
269 rt2x00usb_kick_tx_entry(&queue->entries[i]);
271 for (i = 0; i < index; i++)
272 rt2x00usb_kick_tx_entry(&queue->entries[i]);
275 EXPORT_SYMBOL_GPL(rt2x00usb_kick_tx_queue);
278 * RX data handlers.
280 static void rt2x00usb_interrupt_rxdone(struct urb *urb)
282 struct queue_entry *entry = (struct queue_entry *)urb->context;
283 struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
284 struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
285 u8 rxd[32];
287 if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
288 !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
289 return;
292 * Check if the received data is simply too small
293 * to be actually valid, or if the urb is signaling
294 * a problem.
296 if (urb->actual_length < entry->queue->desc_size || urb->status) {
297 set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
298 usb_submit_urb(urb, GFP_ATOMIC);
299 return;
303 * Fill in desc fields of the skb descriptor
305 skbdesc->desc = rxd;
306 skbdesc->desc_len = entry->queue->desc_size;
309 * Send the frame to rt2x00lib for further processing.
311 rt2x00lib_rxdone(rt2x00dev, entry);
315 * Radio handlers
317 void rt2x00usb_disable_radio(struct rt2x00_dev *rt2x00dev)
319 struct queue_entry_priv_usb *entry_priv;
320 struct queue_entry_priv_usb_bcn *bcn_priv;
321 struct data_queue *queue;
322 unsigned int i;
324 rt2x00usb_vendor_request_sw(rt2x00dev, USB_RX_CONTROL, 0, 0,
325 REGISTER_TIMEOUT);
328 * Cancel all queues.
330 queue_for_each(rt2x00dev, queue) {
331 for (i = 0; i < queue->limit; i++) {
332 entry_priv = queue->entries[i].priv_data;
333 usb_kill_urb(entry_priv->urb);
338 * Kill guardian urb (if required by driver).
340 if (!test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
341 return;
343 for (i = 0; i < rt2x00dev->bcn->limit; i++) {
344 bcn_priv = rt2x00dev->bcn->entries[i].priv_data;
345 if (bcn_priv->guardian_urb)
346 usb_kill_urb(bcn_priv->guardian_urb);
349 EXPORT_SYMBOL_GPL(rt2x00usb_disable_radio);
352 * Device initialization handlers.
354 void rt2x00usb_clear_entry(struct queue_entry *entry)
356 struct usb_device *usb_dev =
357 to_usb_device_intf(entry->queue->rt2x00dev->dev);
358 struct queue_entry_priv_usb *entry_priv = entry->priv_data;
360 if (entry->queue->qid == QID_RX) {
361 usb_fill_bulk_urb(entry_priv->urb, usb_dev,
362 usb_rcvbulkpipe(usb_dev, 1),
363 entry->skb->data, entry->skb->len,
364 rt2x00usb_interrupt_rxdone, entry);
366 set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
367 usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
368 } else {
369 entry->flags = 0;
372 EXPORT_SYMBOL_GPL(rt2x00usb_clear_entry);
374 static int rt2x00usb_alloc_urb(struct rt2x00_dev *rt2x00dev,
375 struct data_queue *queue)
377 struct queue_entry_priv_usb *entry_priv;
378 struct queue_entry_priv_usb_bcn *bcn_priv;
379 unsigned int i;
381 for (i = 0; i < queue->limit; i++) {
382 entry_priv = queue->entries[i].priv_data;
383 entry_priv->urb = usb_alloc_urb(0, GFP_KERNEL);
384 if (!entry_priv->urb)
385 return -ENOMEM;
389 * If this is not the beacon queue or
390 * no guardian byte was required for the beacon,
391 * then we are done.
393 if (rt2x00dev->bcn != queue ||
394 !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
395 return 0;
397 for (i = 0; i < queue->limit; i++) {
398 bcn_priv = queue->entries[i].priv_data;
399 bcn_priv->guardian_urb = usb_alloc_urb(0, GFP_KERNEL);
400 if (!bcn_priv->guardian_urb)
401 return -ENOMEM;
404 return 0;
407 static void rt2x00usb_free_urb(struct rt2x00_dev *rt2x00dev,
408 struct data_queue *queue)
410 struct queue_entry_priv_usb *entry_priv;
411 struct queue_entry_priv_usb_bcn *bcn_priv;
412 unsigned int i;
414 if (!queue->entries)
415 return;
417 for (i = 0; i < queue->limit; i++) {
418 entry_priv = queue->entries[i].priv_data;
419 usb_kill_urb(entry_priv->urb);
420 usb_free_urb(entry_priv->urb);
424 * If this is not the beacon queue or
425 * no guardian byte was required for the beacon,
426 * then we are done.
428 if (rt2x00dev->bcn != queue ||
429 !test_bit(DRIVER_REQUIRE_BEACON_GUARD, &rt2x00dev->flags))
430 return;
432 for (i = 0; i < queue->limit; i++) {
433 bcn_priv = queue->entries[i].priv_data;
434 usb_kill_urb(bcn_priv->guardian_urb);
435 usb_free_urb(bcn_priv->guardian_urb);
439 int rt2x00usb_initialize(struct rt2x00_dev *rt2x00dev)
441 struct data_queue *queue;
442 int status;
445 * Allocate DMA
447 queue_for_each(rt2x00dev, queue) {
448 status = rt2x00usb_alloc_urb(rt2x00dev, queue);
449 if (status)
450 goto exit;
453 return 0;
455 exit:
456 rt2x00usb_uninitialize(rt2x00dev);
458 return status;
460 EXPORT_SYMBOL_GPL(rt2x00usb_initialize);
462 void rt2x00usb_uninitialize(struct rt2x00_dev *rt2x00dev)
464 struct data_queue *queue;
466 queue_for_each(rt2x00dev, queue)
467 rt2x00usb_free_urb(rt2x00dev, queue);
469 EXPORT_SYMBOL_GPL(rt2x00usb_uninitialize);
472 * USB driver handlers.
474 static void rt2x00usb_free_reg(struct rt2x00_dev *rt2x00dev)
476 kfree(rt2x00dev->rf);
477 rt2x00dev->rf = NULL;
479 kfree(rt2x00dev->eeprom);
480 rt2x00dev->eeprom = NULL;
482 kfree(rt2x00dev->csr.cache);
483 rt2x00dev->csr.cache = NULL;
486 static int rt2x00usb_alloc_reg(struct rt2x00_dev *rt2x00dev)
488 rt2x00dev->csr.cache = kzalloc(CSR_CACHE_SIZE, GFP_KERNEL);
489 if (!rt2x00dev->csr.cache)
490 goto exit;
492 rt2x00dev->eeprom = kzalloc(rt2x00dev->ops->eeprom_size, GFP_KERNEL);
493 if (!rt2x00dev->eeprom)
494 goto exit;
496 rt2x00dev->rf = kzalloc(rt2x00dev->ops->rf_size, GFP_KERNEL);
497 if (!rt2x00dev->rf)
498 goto exit;
500 return 0;
502 exit:
503 ERROR_PROBE("Failed to allocate registers.\n");
505 rt2x00usb_free_reg(rt2x00dev);
507 return -ENOMEM;
510 int rt2x00usb_probe(struct usb_interface *usb_intf,
511 const struct usb_device_id *id)
513 struct usb_device *usb_dev = interface_to_usbdev(usb_intf);
514 struct rt2x00_ops *ops = (struct rt2x00_ops *)id->driver_info;
515 struct ieee80211_hw *hw;
516 struct rt2x00_dev *rt2x00dev;
517 int retval;
519 usb_dev = usb_get_dev(usb_dev);
521 hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
522 if (!hw) {
523 ERROR_PROBE("Failed to allocate hardware.\n");
524 retval = -ENOMEM;
525 goto exit_put_device;
528 usb_set_intfdata(usb_intf, hw);
530 rt2x00dev = hw->priv;
531 rt2x00dev->dev = &usb_intf->dev;
532 rt2x00dev->ops = ops;
533 rt2x00dev->hw = hw;
535 rt2x00dev->usb_maxpacket =
536 usb_maxpacket(usb_dev, usb_sndbulkpipe(usb_dev, 1), 1);
537 if (!rt2x00dev->usb_maxpacket)
538 rt2x00dev->usb_maxpacket = 1;
540 retval = rt2x00usb_alloc_reg(rt2x00dev);
541 if (retval)
542 goto exit_free_device;
544 retval = rt2x00lib_probe_dev(rt2x00dev);
545 if (retval)
546 goto exit_free_reg;
548 return 0;
550 exit_free_reg:
551 rt2x00usb_free_reg(rt2x00dev);
553 exit_free_device:
554 ieee80211_free_hw(hw);
556 exit_put_device:
557 usb_put_dev(usb_dev);
559 usb_set_intfdata(usb_intf, NULL);
561 return retval;
563 EXPORT_SYMBOL_GPL(rt2x00usb_probe);
565 void rt2x00usb_disconnect(struct usb_interface *usb_intf)
567 struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
568 struct rt2x00_dev *rt2x00dev = hw->priv;
571 * Free all allocated data.
573 rt2x00lib_remove_dev(rt2x00dev);
574 rt2x00usb_free_reg(rt2x00dev);
575 ieee80211_free_hw(hw);
578 * Free the USB device data.
580 usb_set_intfdata(usb_intf, NULL);
581 usb_put_dev(interface_to_usbdev(usb_intf));
583 EXPORT_SYMBOL_GPL(rt2x00usb_disconnect);
585 #ifdef CONFIG_PM
586 int rt2x00usb_suspend(struct usb_interface *usb_intf, pm_message_t state)
588 struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
589 struct rt2x00_dev *rt2x00dev = hw->priv;
590 int retval;
592 retval = rt2x00lib_suspend(rt2x00dev, state);
593 if (retval)
594 return retval;
596 rt2x00usb_free_reg(rt2x00dev);
599 * Decrease usbdev refcount.
601 usb_put_dev(interface_to_usbdev(usb_intf));
603 return 0;
605 EXPORT_SYMBOL_GPL(rt2x00usb_suspend);
607 int rt2x00usb_resume(struct usb_interface *usb_intf)
609 struct ieee80211_hw *hw = usb_get_intfdata(usb_intf);
610 struct rt2x00_dev *rt2x00dev = hw->priv;
611 int retval;
613 usb_get_dev(interface_to_usbdev(usb_intf));
615 retval = rt2x00usb_alloc_reg(rt2x00dev);
616 if (retval)
617 return retval;
619 retval = rt2x00lib_resume(rt2x00dev);
620 if (retval)
621 goto exit_free_reg;
623 return 0;
625 exit_free_reg:
626 rt2x00usb_free_reg(rt2x00dev);
628 return retval;
630 EXPORT_SYMBOL_GPL(rt2x00usb_resume);
631 #endif /* CONFIG_PM */
634 * rt2x00usb module information.
636 MODULE_AUTHOR(DRV_PROJECT);
637 MODULE_VERSION(DRV_VERSION);
638 MODULE_DESCRIPTION("rt2x00 usb library");
639 MODULE_LICENSE("GPL");