firewire: Add device probing and sysfs integration.
[linux-2.6.git] / drivers / firewire / fw-transaction.c
1 /*                                              -*- c-basic-offset: 8 -*-
2  *
3  * fw-transaction.c - core IEEE1394 transaction logic
4  *
5  * Copyright (C) 2004-2006 Kristian Hoegsberg <krh@bitplanet.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software Foundation,
19  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20  */
21
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/interrupt.h>
26 #include <linux/pci.h>
27 #include <linux/delay.h>
28 #include <linux/poll.h>
29 #include <linux/list.h>
30 #include <linux/kthread.h>
31 #include <asm/uaccess.h>
32 #include <asm/semaphore.h>
33
34 #include "fw-transaction.h"
35 #include "fw-topology.h"
36 #include "fw-device.h"
37
38 #define header_pri(pri)                 ((pri) << 0)
39 #define header_tcode(tcode)             ((tcode) << 4)
40 #define header_retry(retry)             ((retry) << 8)
41 #define header_tlabel(tlabel)           ((tlabel) << 10)
42 #define header_destination(destination) ((destination) << 16)
43 #define header_source(source)           ((source) << 16)
44 #define header_rcode(rcode)             ((rcode) << 12)
45 #define header_offset_high(offset_high) ((offset_high) << 0)
46 #define header_data_length(length)      ((length) << 16)
47 #define header_extended_tcode(tcode)    ((tcode) << 0)
48
49 #define header_get_tcode(q)             (((q) >> 4) & 0x0f)
50 #define header_get_tlabel(q)            (((q) >> 10) & 0x3f)
51 #define header_get_rcode(q)             (((q) >> 4) & 0x0f)
52 #define header_get_destination(q)       (((q) >> 16) & 0xffff)
53 #define header_get_source(q)            (((q) >> 16) & 0xffff)
54 #define header_get_offset_high(q)       (((q) >> 0) & 0xffff)
55 #define header_get_data_length(q)       (((q) >> 16) & 0xffff)
56 #define header_get_extended_tcode(q)    (((q) >> 0) & 0xffff)
57
58 #define phy_config_gap_count(gap_count) (((gap_count) << 16) | (1 << 22))
59 #define phy_config_root_id(node_id)     (((node_id) << 24) | (1 << 23))
60 #define phy_identifier(id)              ((id) << 30)
61
62 static void
63 close_transaction(struct fw_transaction *t, struct fw_card *card, int rcode,
64                   u32 * payload, size_t length)
65 {
66         unsigned long flags;
67
68         spin_lock_irqsave(&card->lock, flags);
69         card->tlabel_mask &= ~(1 << t->tlabel);
70         list_del(&t->link);
71         spin_unlock_irqrestore(&card->lock, flags);
72
73         t->callback(card, rcode, payload, length, t->callback_data);
74 }
75
76 static void
77 transmit_complete_callback(struct fw_packet *packet,
78                            struct fw_card *card, int status)
79 {
80         struct fw_transaction *t =
81             container_of(packet, struct fw_transaction, packet);
82
83         switch (status) {
84         case ACK_COMPLETE:
85                 close_transaction(t, card, RCODE_COMPLETE, NULL, 0);
86                 break;
87         case ACK_PENDING:
88                 t->timestamp = packet->timestamp;
89                 break;
90         case ACK_BUSY_X:
91         case ACK_BUSY_A:
92         case ACK_BUSY_B:
93                 close_transaction(t, card, RCODE_BUSY, NULL, 0);
94                 break;
95         case ACK_DATA_ERROR:
96         case ACK_TYPE_ERROR:
97                 close_transaction(t, card, RCODE_SEND_ERROR, NULL, 0);
98                 break;
99         default:
100                 /* FIXME: In this case, status is a negative errno,
101                  * corresponding to an OHCI specific transmit error
102                  * code.  We should map that to an RCODE instead of
103                  * just the generic RCODE_SEND_ERROR. */
104                 close_transaction(t, card, RCODE_SEND_ERROR, NULL, 0);
105                 break;
106         }
107 }
108
109 void
110 fw_fill_packet(struct fw_packet *packet, int tcode, int tlabel,
111                int node_id, int generation, int speed,
112                unsigned long long offset, void *payload, size_t length)
113 {
114         int ext_tcode;
115
116         if (tcode > 0x10) {
117                 ext_tcode = tcode - 0x10;
118                 tcode = TCODE_LOCK_REQUEST;
119         } else
120                 ext_tcode = 0;
121
122         packet->header[0] =
123                 header_retry(RETRY_X) |
124                 header_tlabel(tlabel) |
125                 header_tcode(tcode) |
126                 header_destination(node_id | LOCAL_BUS);
127         packet->header[1] =
128                 header_offset_high(offset >> 32) | header_source(0);
129         packet->header[2] =
130                 offset;
131
132         switch (tcode) {
133         case TCODE_WRITE_QUADLET_REQUEST:
134                 packet->header[3] = *(u32 *)payload;
135                 packet->header_length = 16;
136                 packet->payload_length = 0;
137                 break;
138
139         case TCODE_LOCK_REQUEST:
140         case TCODE_WRITE_BLOCK_REQUEST:
141                 packet->header[3] =
142                         header_data_length(length) |
143                         header_extended_tcode(ext_tcode);
144                 packet->header_length = 16;
145                 packet->payload = payload;
146                 packet->payload_length = length;
147                 break;
148
149         case TCODE_READ_QUADLET_REQUEST:
150                 packet->header_length = 12;
151                 packet->payload_length = 0;
152                 break;
153
154         case TCODE_READ_BLOCK_REQUEST:
155                 packet->header[3] =
156                         header_data_length(length) |
157                         header_extended_tcode(ext_tcode);
158                 packet->header_length = 16;
159                 packet->payload_length = 0;
160                 break;
161         }
162
163         packet->speed = speed;
164         packet->generation = generation;
165 }
166
167 /**
168  * This function provides low-level access to the IEEE1394 transaction
169  * logic.  Most C programs would use either fw_read(), fw_write() or
170  * fw_lock() instead - those function are convenience wrappers for
171  * this function.  The fw_send_request() function is primarily
172  * provided as a flexible, one-stop entry point for languages bindings
173  * and protocol bindings.
174  *
175  * FIXME: Document this function further, in particular the possible
176  * values for rcode in the callback.  In short, we map ACK_COMPLETE to
177  * RCODE_COMPLETE, internal errors set errno and set rcode to
178  * RCODE_SEND_ERROR (which is out of range for standard ieee1394
179  * rcodes).  All other rcodes are forwarded unchanged.  For all
180  * errors, payload is NULL, length is 0.
181  *
182  * Can not expect the callback to be called before the function
183  * returns, though this does happen in some cases (ACK_COMPLETE and
184  * errors).
185  *
186  * The payload is only used for write requests and must not be freed
187  * until the callback has been called.
188  *
189  * @param card the card from which to send the request
190  * @param tcode the tcode for this transaction.  Do not use
191  *   TCODE_LOCK_REQUEST directly, insted use TCODE_LOCK_MASK_SWAP
192  *   etc. to specify tcode and ext_tcode.
193  * @param node_id the node_id of the destination node
194  * @param generation the generation for which node_id is valid
195  * @param speed the speed to use for sending the request
196  * @param offset the 48 bit offset on the destination node
197  * @param payload the data payload for the request subaction
198  * @param length the length in bytes of the data to read
199  * @param callback function to be called when the transaction is completed
200  * @param callback_data pointer to arbitrary data, which will be
201  *   passed to the callback
202  */
203 void
204 fw_send_request(struct fw_card *card, struct fw_transaction *t,
205                 int tcode, int node_id, int generation, int speed,
206                 unsigned long long offset,
207                 void *payload, size_t length,
208                 fw_transaction_callback_t callback, void *callback_data)
209 {
210         unsigned long flags;
211         int tlabel;
212
213         /* Bump the flush timer up 100ms first of all so we
214          * don't race with a flush timer callback. */
215
216         mod_timer(&card->flush_timer, jiffies + DIV_ROUND_UP(HZ, 10));
217
218         /* Allocate tlabel from the bitmap and put the transaction on
219          * the list while holding the card spinlock. */
220
221         spin_lock_irqsave(&card->lock, flags);
222
223         tlabel = card->current_tlabel;
224         if (card->tlabel_mask & (1 << tlabel)) {
225                 spin_unlock_irqrestore(&card->lock, flags);
226                 callback(card, RCODE_SEND_ERROR, NULL, 0, callback_data);
227                 return;
228         }
229
230         card->current_tlabel = (card->current_tlabel + 1) & 0x1f;
231         card->tlabel_mask |= (1 << tlabel);
232
233         list_add_tail(&t->link, &card->transaction_list);
234
235         spin_unlock_irqrestore(&card->lock, flags);
236
237         /* Initialize rest of transaction, fill out packet and send it. */
238         t->node_id = node_id;
239         t->tlabel = tlabel;
240         t->callback = callback;
241         t->callback_data = callback_data;
242
243         fw_fill_packet(&t->packet, tcode, t->tlabel,
244                        node_id, generation, speed, offset, payload, length);
245         t->packet.callback = transmit_complete_callback;
246
247         card->driver->send_request(card, &t->packet);
248 }
249 EXPORT_SYMBOL(fw_send_request);
250
251 static void
252 transmit_phy_packet_callback(struct fw_packet *packet,
253                              struct fw_card *card, int status)
254 {
255         kfree(packet);
256 }
257
258 static void send_phy_packet(struct fw_card *card, u32 data, int generation)
259 {
260         struct fw_packet *packet;
261
262         packet = kzalloc(sizeof *packet, GFP_ATOMIC);
263         if (packet == NULL)
264                 return;
265
266         packet->header[0] = data;
267         packet->header[1] = ~data;
268         packet->header_length = 8;
269         packet->payload_length = 0;
270         packet->speed = SCODE_100;
271         packet->generation = generation;
272         packet->callback = transmit_phy_packet_callback;
273
274         card->driver->send_request(card, packet);
275 }
276
277 void fw_send_force_root(struct fw_card *card, int node_id, int generation)
278 {
279         u32 q;
280
281         q = phy_identifier(PHY_PACKET_CONFIG) | phy_config_root_id(node_id);
282         send_phy_packet(card, q, generation);
283 }
284
285 void fw_flush_transactions(struct fw_card *card)
286 {
287         struct fw_transaction *t, *next;
288         struct list_head list;
289         unsigned long flags;
290
291         INIT_LIST_HEAD(&list);
292         spin_lock_irqsave(&card->lock, flags);
293         list_splice_init(&card->transaction_list, &list);
294         card->tlabel_mask = 0;
295         spin_unlock_irqrestore(&card->lock, flags);
296
297         list_for_each_entry_safe(t, next, &list, link)
298                 t->callback(card, RCODE_CANCELLED, NULL, 0, t->callback_data);
299 }
300
301 static struct fw_address_handler *
302 lookup_overlapping_address_handler(struct list_head *list,
303                                    unsigned long long offset, size_t length)
304 {
305         struct fw_address_handler *handler;
306
307         list_for_each_entry(handler, list, link) {
308                 if (handler->offset < offset + length &&
309                     offset < handler->offset + handler->length)
310                         return handler;
311         }
312
313         return NULL;
314 }
315
316 static struct fw_address_handler *
317 lookup_enclosing_address_handler(struct list_head *list,
318                                  unsigned long long offset, size_t length)
319 {
320         struct fw_address_handler *handler;
321
322         list_for_each_entry(handler, list, link) {
323                 if (handler->offset <= offset &&
324                     offset + length <= handler->offset + handler->length)
325                         return handler;
326         }
327
328         return NULL;
329 }
330
331 static DEFINE_SPINLOCK(address_handler_lock);
332 static LIST_HEAD(address_handler_list);
333
334 struct fw_address_region fw_low_memory_region =
335         { 0x000000000000ull, 0x000100000000ull };
336 struct fw_address_region fw_high_memory_region =
337         { 0x000100000000ull, 0xffffe0000000ull };
338 struct fw_address_region fw_private_region =
339         { 0xffffe0000000ull, 0xfffff0000000ull };
340 struct fw_address_region fw_csr_region =
341         { 0xfffff0000000ULL, 0xfffff0000800ull };
342 struct fw_address_region fw_unit_space_region =
343         { 0xfffff0000900ull, 0x1000000000000ull };
344
345 EXPORT_SYMBOL(fw_low_memory_region);
346 EXPORT_SYMBOL(fw_high_memory_region);
347 EXPORT_SYMBOL(fw_private_region);
348 EXPORT_SYMBOL(fw_csr_region);
349 EXPORT_SYMBOL(fw_unit_space_region);
350
351 /**
352  * Allocate a range of addresses in the node space of the OHCI
353  * controller.  When a request is received that falls within the
354  * specified address range, the specified callback is invoked.  The
355  * parameters passed to the callback give the details of the
356  * particular request
357  */
358
359 int
360 fw_core_add_address_handler(struct fw_address_handler *handler,
361                             struct fw_address_region *region)
362 {
363         struct fw_address_handler *other;
364         unsigned long flags;
365         int ret = -EBUSY;
366
367         spin_lock_irqsave(&address_handler_lock, flags);
368
369         handler->offset = region->start;
370         while (handler->offset + handler->length <= region->end) {
371                 other =
372                     lookup_overlapping_address_handler(&address_handler_list,
373                                                        handler->offset,
374                                                        handler->length);
375                 if (other != NULL) {
376                         handler->offset += other->length;
377                 } else {
378                         list_add_tail(&handler->link, &address_handler_list);
379                         ret = 0;
380                         break;
381                 }
382         }
383
384         spin_unlock_irqrestore(&address_handler_lock, flags);
385
386         return ret;
387 }
388
389 EXPORT_SYMBOL(fw_core_add_address_handler);
390
391 /**
392  * Deallocate a range of addresses allocated with fw_allocate.  This
393  * will call the associated callback one last time with a the special
394  * tcode TCODE_DEALLOCATE, to let the client destroy the registered
395  * callback data.  For convenience, the callback parameters offset and
396  * length are set to the start and the length respectively for the
397  * deallocated region, payload is set to NULL.
398  */
399
400 void fw_core_remove_address_handler(struct fw_address_handler *handler)
401 {
402         unsigned long flags;
403
404         spin_lock_irqsave(&address_handler_lock, flags);
405         list_del(&handler->link);
406         spin_unlock_irqrestore(&address_handler_lock, flags);
407 }
408
409 EXPORT_SYMBOL(fw_core_remove_address_handler);
410
411 struct fw_request {
412         struct fw_packet response;
413         int ack;
414         u32 length;
415         u32 data[0];
416 };
417
418 static void
419 free_response_callback(struct fw_packet *packet,
420                        struct fw_card *card, int status)
421 {
422         struct fw_request *request;
423
424         request = container_of(packet, struct fw_request, response);
425         kfree(request);
426 }
427
428 static void
429 fw_fill_response(struct fw_packet *response,
430                  u32 *request, u32 *data, size_t length)
431 {
432         int tcode, tlabel, extended_tcode, source, destination;
433
434         tcode          = header_get_tcode(request[0]);
435         tlabel         = header_get_tlabel(request[0]);
436         source         = header_get_destination(request[0]);
437         destination    = header_get_source(request[1]);
438         extended_tcode = header_get_extended_tcode(request[3]);
439
440         response->header[0] =
441                 header_retry(RETRY_1) |
442                 header_tlabel(tlabel) |
443                 header_destination(destination);
444         response->header[1] = header_source(source);
445         response->header[2] = 0;
446
447         switch (tcode) {
448         case TCODE_WRITE_QUADLET_REQUEST:
449         case TCODE_WRITE_BLOCK_REQUEST:
450                 response->header[0] |= header_tcode(TCODE_WRITE_RESPONSE);
451                 response->header_length = 12;
452                 response->payload_length = 0;
453                 break;
454
455         case TCODE_READ_QUADLET_REQUEST:
456                 response->header[0] |=
457                         header_tcode(TCODE_READ_QUADLET_RESPONSE);
458                 response->header[3] = 0;
459                 response->header_length = 16;
460                 response->payload_length = 0;
461                 break;
462
463         case TCODE_READ_BLOCK_REQUEST:
464         case TCODE_LOCK_REQUEST:
465                 response->header[0] |= header_tcode(tcode + 2);
466                 response->header[3] =
467                         header_data_length(length) |
468                         header_extended_tcode(extended_tcode);
469                 response->header_length = 16;
470                 response->payload = data;
471                 response->payload_length = length;
472                 break;
473
474         default:
475                 BUG();
476                 return;
477         }
478 }
479
480 static struct fw_request *
481 allocate_request(u32 *header, int ack,
482                  int speed, int timestamp, int generation)
483 {
484         struct fw_request *request;
485         u32 *data, length;
486         int request_tcode;
487
488         request_tcode = header_get_tcode(header[0]);
489         switch (request_tcode) {
490         case TCODE_WRITE_QUADLET_REQUEST:
491                 data = &header[3];
492                 length = 4;
493                 break;
494
495         case TCODE_WRITE_BLOCK_REQUEST:
496         case TCODE_LOCK_REQUEST:
497                 data = &header[4];
498                 length = header_get_data_length(header[3]);
499                 break;
500
501         case TCODE_READ_QUADLET_REQUEST:
502                 data = NULL;
503                 length = 4;
504                 break;
505
506         case TCODE_READ_BLOCK_REQUEST:
507                 data = NULL;
508                 length = header_get_data_length(header[3]);
509                 break;
510
511         default:
512                 BUG();
513                 return NULL;
514         }
515
516         request = kmalloc(sizeof *request + length, GFP_ATOMIC);
517         if (request == NULL)
518                 return NULL;
519
520         request->response.speed = speed;
521         request->response.timestamp = timestamp;
522         request->response.generation = generation;
523         request->response.callback = free_response_callback;
524         request->ack = ack;
525         request->length = length;
526         if (data)
527                 memcpy(request->data, data, length);
528
529         fw_fill_response(&request->response, header, request->data, length);
530
531         return request;
532 }
533
534 void
535 fw_send_response(struct fw_card *card, struct fw_request *request, int rcode)
536 {
537         int response_tcode;
538
539         /* Broadcast packets are reported as ACK_COMPLETE, so this
540          * check is sufficient to ensure we don't send response to
541          * broadcast packets or posted writes. */
542         if (request->ack != ACK_PENDING)
543                 return;
544
545         request->response.header[1] |= header_rcode(rcode);
546         response_tcode = header_get_tcode(request->response.header[0]);
547         if (rcode != RCODE_COMPLETE)
548                 /* Clear the data_length field. */
549                 request->response.header[3] &= 0xffff;
550         else if (response_tcode == TCODE_READ_QUADLET_RESPONSE)
551                 request->response.header[3] = request->data[0];
552
553         card->driver->send_response(card, &request->response);
554 }
555
556 EXPORT_SYMBOL(fw_send_response);
557
558 void
559 fw_core_handle_request(struct fw_card *card,
560                        int speed, int ack, int timestamp,
561                        int generation, u32 length, u32 *header)
562 {
563         struct fw_address_handler *handler;
564         struct fw_request *request;
565         unsigned long long offset;
566         unsigned long flags;
567         int tcode, destination, source, t;
568
569         if (length > 2048) {
570                 /* FIXME: send error response. */
571                 return;
572         }
573
574         if (ack != ACK_PENDING && ack != ACK_COMPLETE)
575                 return;
576
577         t = (timestamp & 0x1fff) + 4000;
578         if (t >= 8000)
579                 t = (timestamp & ~0x1fff) + 0x2000 + t - 8000;
580         else
581                 t = (timestamp & ~0x1fff) + t;
582
583         request = allocate_request(header, ack, speed, t, generation);
584         if (request == NULL) {
585                 /* FIXME: send statically allocated busy packet. */
586                 return;
587         }
588
589         offset      =
590                 ((unsigned long long)
591                  header_get_offset_high(header[1]) << 32) | header[2];
592         tcode       = header_get_tcode(header[0]);
593         destination = header_get_destination(header[0]);
594         source      = header_get_source(header[0]);
595
596         spin_lock_irqsave(&address_handler_lock, flags);
597         handler = lookup_enclosing_address_handler(&address_handler_list,
598                                                    offset, request->length);
599         spin_unlock_irqrestore(&address_handler_lock, flags);
600
601         /* FIXME: lookup the fw_node corresponding to the sender of
602          * this request and pass that to the address handler instead
603          * of the node ID.  We may also want to move the address
604          * allocations to fw_node so we only do this callback if the
605          * upper layers registered it for this node. */
606
607         if (handler == NULL)
608                 fw_send_response(card, request, RCODE_ADDRESS_ERROR);
609         else
610                 handler->address_callback(card, request,
611                                           tcode, destination, source,
612                                           generation, speed, offset,
613                                           request->data, request->length,
614                                           handler->callback_data);
615 }
616
617 EXPORT_SYMBOL(fw_core_handle_request);
618
619 void
620 fw_core_handle_response(struct fw_card *card,
621                         int speed, int ack, int timestamp,
622                         u32 length, u32 *header)
623 {
624         struct fw_transaction *t;
625         unsigned long flags;
626         u32 *data;
627         size_t data_length;
628         int tcode, tlabel, destination, source, rcode;
629
630         tcode       = header_get_tcode(header[0]);
631         tlabel      = header_get_tlabel(header[0]);
632         destination = header_get_destination(header[0]);
633         source      = header_get_source(header[1]);
634         rcode       = header_get_rcode(header[1]);
635
636         spin_lock_irqsave(&card->lock, flags);
637         list_for_each_entry(t, &card->transaction_list, link) {
638                 if (t->node_id == source && t->tlabel == tlabel) {
639                         list_del(&t->link);
640                         card->tlabel_mask &= ~(1 << t->tlabel);
641                         break;
642                 }
643         }
644         spin_unlock_irqrestore(&card->lock, flags);
645
646         if (&t->link == &card->transaction_list) {
647                 fw_notify("Unsolicited response\n");
648                 return;
649         }
650
651         /* FIXME: sanity check packet, is length correct, does tcodes
652          * and addresses match. */
653
654         switch (tcode) {
655         case TCODE_READ_QUADLET_RESPONSE:
656                 data = (u32 *) &header[3];
657                 data_length = 4;
658                 break;
659
660         case TCODE_WRITE_RESPONSE:
661                 data = NULL;
662                 data_length = 0;
663                 break;
664
665         case TCODE_READ_BLOCK_RESPONSE:
666         case TCODE_LOCK_RESPONSE:
667                 data = &header[4];
668                 data_length = header_get_data_length(header[3]);
669                 break;
670
671         default:
672                 /* Should never happen, this is just to shut up gcc. */
673                 data = NULL;
674                 data_length = 0;
675                 break;
676         }
677
678         t->callback(card, rcode, data, data_length, t->callback_data);
679 }
680
681 EXPORT_SYMBOL(fw_core_handle_response);
682
683 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
684 MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
685 MODULE_LICENSE("GPL");
686
687 static u32 vendor_textual_descriptor_data[] = {
688         /* textual descriptor leaf () */
689         0x00080000,
690         0x00000000,
691         0x00000000,
692         0x4c696e75,             /* L i n u */
693         0x78204669,             /* x   F i */
694         0x72657769,             /* r e w i */
695         0x72652028,             /* r e   ( */
696         0x4a554a55,             /* J U J U */
697         0x29000000,             /* )       */
698 };
699
700 static struct fw_descriptor vendor_textual_descriptor = {
701         .length = ARRAY_SIZE(vendor_textual_descriptor_data),
702         .key = 0x81000000,
703         .data = vendor_textual_descriptor_data
704 };
705
706 static int __init fw_core_init(void)
707 {
708         int retval;
709
710         retval = bus_register(&fw_bus_type);
711         if (retval < 0)
712                 return retval;
713
714         /* Add the vendor textual descriptor. */
715         retval = fw_core_add_descriptor(&vendor_textual_descriptor);
716         BUG_ON(retval < 0);
717
718         return 0;
719 }
720
721 static void __exit fw_core_cleanup(void)
722 {
723         bus_unregister(&fw_bus_type);
724 }
725
726 module_init(fw_core_init);
727 module_exit(fw_core_cleanup);