firewire: Use struct fw_packet for incoming packets too in controller interface.
[safe/jmp/linux-2.6] / 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) & 0x3f) << 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 static 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);
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 destination node ID (bus ID and PHY ID concatenated)
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_phy_config(struct fw_card *card,
278                         int node_id, int generation, int gap_count)
279 {
280         u32 q;
281
282         q = phy_identifier(PHY_PACKET_CONFIG) |
283                 phy_config_root_id(node_id) |
284                 phy_config_gap_count(gap_count);
285
286         send_phy_packet(card, q, generation);
287 }
288
289 void fw_flush_transactions(struct fw_card *card)
290 {
291         struct fw_transaction *t, *next;
292         struct list_head list;
293         unsigned long flags;
294
295         INIT_LIST_HEAD(&list);
296         spin_lock_irqsave(&card->lock, flags);
297         list_splice_init(&card->transaction_list, &list);
298         card->tlabel_mask = 0;
299         spin_unlock_irqrestore(&card->lock, flags);
300
301         list_for_each_entry_safe(t, next, &list, link)
302                 t->callback(card, RCODE_CANCELLED, NULL, 0, t->callback_data);
303 }
304
305 static struct fw_address_handler *
306 lookup_overlapping_address_handler(struct list_head *list,
307                                    unsigned long long offset, size_t length)
308 {
309         struct fw_address_handler *handler;
310
311         list_for_each_entry(handler, list, link) {
312                 if (handler->offset < offset + length &&
313                     offset < handler->offset + handler->length)
314                         return handler;
315         }
316
317         return NULL;
318 }
319
320 static struct fw_address_handler *
321 lookup_enclosing_address_handler(struct list_head *list,
322                                  unsigned long long offset, size_t length)
323 {
324         struct fw_address_handler *handler;
325
326         list_for_each_entry(handler, list, link) {
327                 if (handler->offset <= offset &&
328                     offset + length <= handler->offset + handler->length)
329                         return handler;
330         }
331
332         return NULL;
333 }
334
335 static DEFINE_SPINLOCK(address_handler_lock);
336 static LIST_HEAD(address_handler_list);
337
338 const struct fw_address_region fw_low_memory_region =
339         { .start = 0x000000000000ULL, .end = 0x000100000000ULL,  };
340 const struct fw_address_region fw_high_memory_region =
341         { .start = 0x000100000000ULL, .end = 0xffffe0000000ULL,  };
342 const struct fw_address_region fw_private_region =
343         { .start = 0xffffe0000000ULL, .end = 0xfffff0000000ULL,  };
344 const struct fw_address_region fw_csr_region =
345         { .start = 0xfffff0000000ULL, .end = 0xfffff0000800ULL,  };
346 const struct fw_address_region fw_unit_space_region =
347         { .start = 0xfffff0000900ULL, .end = 0x1000000000000ULL, };
348 EXPORT_SYMBOL(fw_low_memory_region);
349 EXPORT_SYMBOL(fw_high_memory_region);
350 EXPORT_SYMBOL(fw_private_region);
351 EXPORT_SYMBOL(fw_csr_region);
352 EXPORT_SYMBOL(fw_unit_space_region);
353
354 /**
355  * Allocate a range of addresses in the node space of the OHCI
356  * controller.  When a request is received that falls within the
357  * specified address range, the specified callback is invoked.  The
358  * parameters passed to the callback give the details of the
359  * particular request
360  */
361 int
362 fw_core_add_address_handler(struct fw_address_handler *handler,
363                             const struct fw_address_region *region)
364 {
365         struct fw_address_handler *other;
366         unsigned long flags;
367         int ret = -EBUSY;
368
369         spin_lock_irqsave(&address_handler_lock, flags);
370
371         handler->offset = region->start;
372         while (handler->offset + handler->length <= region->end) {
373                 other =
374                     lookup_overlapping_address_handler(&address_handler_list,
375                                                        handler->offset,
376                                                        handler->length);
377                 if (other != NULL) {
378                         handler->offset += other->length;
379                 } else {
380                         list_add_tail(&handler->link, &address_handler_list);
381                         ret = 0;
382                         break;
383                 }
384         }
385
386         spin_unlock_irqrestore(&address_handler_lock, flags);
387
388         return ret;
389 }
390 EXPORT_SYMBOL(fw_core_add_address_handler);
391
392 /**
393  * Deallocate a range of addresses allocated with fw_allocate.  This
394  * will call the associated callback one last time with a the special
395  * tcode TCODE_DEALLOCATE, to let the client destroy the registered
396  * callback data.  For convenience, the callback parameters offset and
397  * length are set to the start and the length respectively for the
398  * deallocated region, payload is set to NULL.
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 EXPORT_SYMBOL(fw_core_remove_address_handler);
409
410 struct fw_request {
411         struct fw_packet response;
412         int ack;
413         u32 length;
414         u32 data[0];
415 };
416
417 static void
418 free_response_callback(struct fw_packet *packet,
419                        struct fw_card *card, int status)
420 {
421         struct fw_request *request;
422
423         request = container_of(packet, struct fw_request, response);
424         kfree(request);
425 }
426
427 static void
428 fw_fill_response(struct fw_packet *response,
429                  struct fw_packet *request, void *data)
430 {
431         int tcode, tlabel, extended_tcode, source, destination;
432
433         tcode          = header_get_tcode(request->header[0]);
434         tlabel         = header_get_tlabel(request->header[0]);
435         source         = header_get_destination(request->header[0]);
436         destination    = header_get_source(request->header[1]);
437         extended_tcode = header_get_extended_tcode(request->header[3]);
438
439         response->header[0] =
440                 header_retry(RETRY_1) |
441                 header_tlabel(tlabel) |
442                 header_destination(destination);
443         response->header[1] = header_source(source);
444         response->header[2] = 0;
445
446         switch (tcode) {
447         case TCODE_WRITE_QUADLET_REQUEST:
448         case TCODE_WRITE_BLOCK_REQUEST:
449                 response->header[0] |= header_tcode(TCODE_WRITE_RESPONSE);
450                 response->header_length = 12;
451                 response->payload_length = 0;
452                 break;
453
454         case TCODE_READ_QUADLET_REQUEST:
455                 response->header[0] |=
456                         header_tcode(TCODE_READ_QUADLET_RESPONSE);
457                 response->header[3] = 0;
458                 response->header_length = 16;
459                 response->payload_length = 0;
460                 break;
461
462         case TCODE_READ_BLOCK_REQUEST:
463         case TCODE_LOCK_REQUEST:
464                 response->header[0] |= header_tcode(tcode + 2);
465                 response->header[3] =
466                         header_data_length(request->payload_length) |
467                         header_extended_tcode(extended_tcode);
468                 response->header_length = 16;
469                 response->payload = data;
470                 response->payload_length = request->payload_length;
471                 break;
472
473         default:
474                 BUG();
475                 return;
476         }
477 }
478
479 static struct fw_request *
480 allocate_request(struct fw_packet *p)
481 {
482         struct fw_request *request;
483         u32 *data, length;
484         int request_tcode, t;
485
486         request_tcode = header_get_tcode(p->header[0]);
487         switch (request_tcode) {
488         case TCODE_WRITE_QUADLET_REQUEST:
489                 data = &p->header[3];
490                 length = 4;
491                 break;
492
493         case TCODE_WRITE_BLOCK_REQUEST:
494         case TCODE_LOCK_REQUEST:
495                 data = p->payload;
496                 length = header_get_data_length(p->header[3]);
497                 break;
498
499         case TCODE_READ_QUADLET_REQUEST:
500                 data = NULL;
501                 length = 4;
502                 break;
503
504         case TCODE_READ_BLOCK_REQUEST:
505                 data = NULL;
506                 length = header_get_data_length(p->header[3]);
507                 break;
508
509         default:
510                 BUG();
511                 return NULL;
512         }
513
514         request = kmalloc(sizeof *request + length, GFP_ATOMIC);
515         if (request == NULL)
516                 return NULL;
517
518         t = (p->timestamp & 0x1fff) + 4000;
519         if (t >= 8000)
520                 t = (p->timestamp & ~0x1fff) + 0x2000 + t - 8000;
521         else
522                 t = (p->timestamp & ~0x1fff) + t;
523
524         request->response.speed = p->speed;
525         request->response.timestamp = t;
526         request->response.generation = p->generation;
527         request->response.callback = free_response_callback;
528         request->ack = p->ack;
529         request->length = p->payload_length;
530         if (data)
531                 memcpy(request->data, p->payload, p->payload_length);
532
533         fw_fill_response(&request->response, p, request->data);
534
535         return request;
536 }
537
538 void
539 fw_send_response(struct fw_card *card, struct fw_request *request, int rcode)
540 {
541         int response_tcode;
542
543         /* Broadcast packets are reported as ACK_COMPLETE, so this
544          * check is sufficient to ensure we don't send response to
545          * broadcast packets or posted writes. */
546         if (request->ack != ACK_PENDING)
547                 return;
548
549         request->response.header[1] |= header_rcode(rcode);
550         response_tcode = header_get_tcode(request->response.header[0]);
551         if (rcode != RCODE_COMPLETE)
552                 /* Clear the data_length field. */
553                 request->response.header[3] &= 0xffff;
554         else if (response_tcode == TCODE_READ_QUADLET_RESPONSE)
555                 request->response.header[3] = request->data[0];
556
557         card->driver->send_response(card, &request->response);
558 }
559 EXPORT_SYMBOL(fw_send_response);
560
561 void
562 fw_core_handle_request(struct fw_card *card, struct fw_packet *p)
563 {
564         struct fw_address_handler *handler;
565         struct fw_request *request;
566         unsigned long long offset;
567         unsigned long flags;
568         int tcode, destination, source;
569
570         if (p->payload_length > 2048) {
571                 /* FIXME: send error response. */
572                 return;
573         }
574
575         if (p->ack != ACK_PENDING && p->ack != ACK_COMPLETE)
576                 return;
577
578         request = allocate_request(p);
579         if (request == NULL) {
580                 /* FIXME: send statically allocated busy packet. */
581                 return;
582         }
583
584         offset      =
585                 ((unsigned long long)
586                  header_get_offset_high(p->header[1]) << 32) | p->header[2];
587         tcode       = header_get_tcode(p->header[0]);
588         destination = header_get_destination(p->header[0]);
589         source      = header_get_source(p->header[0]);
590
591         spin_lock_irqsave(&address_handler_lock, flags);
592         handler = lookup_enclosing_address_handler(&address_handler_list,
593                                                    offset, request->length);
594         spin_unlock_irqrestore(&address_handler_lock, flags);
595
596         /* FIXME: lookup the fw_node corresponding to the sender of
597          * this request and pass that to the address handler instead
598          * of the node ID.  We may also want to move the address
599          * allocations to fw_node so we only do this callback if the
600          * upper layers registered it for this node. */
601
602         if (handler == NULL)
603                 fw_send_response(card, request, RCODE_ADDRESS_ERROR);
604         else
605                 handler->address_callback(card, request,
606                                           tcode, destination, source,
607                                           p->generation, p->speed, offset,
608                                           request->data, request->length,
609                                           handler->callback_data);
610 }
611 EXPORT_SYMBOL(fw_core_handle_request);
612
613 void
614 fw_core_handle_response(struct fw_card *card, struct fw_packet *p)
615 {
616         struct fw_transaction *t;
617         unsigned long flags;
618         u32 *data;
619         size_t data_length;
620         int tcode, tlabel, destination, source, rcode;
621
622         tcode       = header_get_tcode(p->header[0]);
623         tlabel      = header_get_tlabel(p->header[0]);
624         destination = header_get_destination(p->header[0]);
625         source      = header_get_source(p->header[1]);
626         rcode       = header_get_rcode(p->header[1]);
627
628         spin_lock_irqsave(&card->lock, flags);
629         list_for_each_entry(t, &card->transaction_list, link) {
630                 if (t->node_id == source && t->tlabel == tlabel) {
631                         list_del(&t->link);
632                         card->tlabel_mask &= ~(1 << t->tlabel);
633                         break;
634                 }
635         }
636         spin_unlock_irqrestore(&card->lock, flags);
637
638         if (&t->link == &card->transaction_list) {
639                 fw_notify("Unsolicited response\n");
640                 return;
641         }
642
643         /* FIXME: sanity check packet, is length correct, does tcodes
644          * and addresses match. */
645
646         switch (tcode) {
647         case TCODE_READ_QUADLET_RESPONSE:
648                 data = (u32 *) &p->header[3];
649                 data_length = 4;
650                 break;
651
652         case TCODE_WRITE_RESPONSE:
653                 data = NULL;
654                 data_length = 0;
655                 break;
656
657         case TCODE_READ_BLOCK_RESPONSE:
658         case TCODE_LOCK_RESPONSE:
659                 data = &p->header[4];
660                 data_length = header_get_data_length(p->header[3]);
661                 break;
662
663         default:
664                 /* Should never happen, this is just to shut up gcc. */
665                 data = NULL;
666                 data_length = 0;
667                 break;
668         }
669
670         t->callback(card, rcode, data, data_length, t->callback_data);
671 }
672 EXPORT_SYMBOL(fw_core_handle_response);
673
674 MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");
675 MODULE_DESCRIPTION("Core IEEE1394 transaction logic");
676 MODULE_LICENSE("GPL");
677
678 static const u32 vendor_textual_descriptor_data[] = {
679         /* textual descriptor leaf () */
680         0x00080000,
681         0x00000000,
682         0x00000000,
683         0x4c696e75,             /* L i n u */
684         0x78204669,             /* x   F i */
685         0x72657769,             /* r e w i */
686         0x72652028,             /* r e   ( */
687         0x4a554a55,             /* J U J U */
688         0x29000000,             /* )       */
689 };
690
691 static struct fw_descriptor vendor_textual_descriptor = {
692         .length = ARRAY_SIZE(vendor_textual_descriptor_data),
693         .key = 0x81000000,
694         .data = vendor_textual_descriptor_data,
695 };
696
697 static int __init fw_core_init(void)
698 {
699         int retval;
700
701         retval = bus_register(&fw_bus_type);
702         if (retval < 0)
703                 return retval;
704
705         /* Add the vendor textual descriptor. */
706         retval = fw_core_add_descriptor(&vendor_textual_descriptor);
707         BUG_ON(retval < 0);
708
709         return 0;
710 }
711
712 static void __exit fw_core_cleanup(void)
713 {
714         bus_unregister(&fw_bus_type);
715 }
716
717 module_init(fw_core_init);
718 module_exit(fw_core_cleanup);