lguest: update commentry
[linux-2.6] / drivers / firmware / dell_rbu.c
1 /*
2  * dell_rbu.c
3  * Bios Update driver for Dell systems
4  * Author: Dell Inc
5  *         Abhay Salunke <abhay_salunke@dell.com>
6  *
7  * Copyright (C) 2005 Dell Inc.
8  *
9  * Remote BIOS Update (rbu) driver is used for updating DELL BIOS by
10  * creating entries in the /sys file systems on Linux 2.6 and higher
11  * kernels. The driver supports two mechanism to update the BIOS namely
12  * contiguous and packetized. Both these methods still require having some
13  * application to set the CMOS bit indicating the BIOS to update itself
14  * after a reboot.
15  *
16  * Contiguous method:
17  * This driver writes the incoming data in a monolithic image by allocating
18  * contiguous physical pages large enough to accommodate the incoming BIOS
19  * image size.
20  *
21  * Packetized method:
22  * The driver writes the incoming packet image by allocating a new packet
23  * on every time the packet data is written. This driver requires an
24  * application to break the BIOS image in to fixed sized packet chunks.
25  *
26  * See Documentation/dell_rbu.txt for more info.
27  *
28  * This program is free software; you can redistribute it and/or modify
29  * it under the terms of the GNU General Public License v2.0 as published by
30  * the Free Software Foundation
31  *
32  * This program is distributed in the hope that it will be useful,
33  * but WITHOUT ANY WARRANTY; without even the implied warranty of
34  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
35  * GNU General Public License for more details.
36  */
37 #include <linux/init.h>
38 #include <linux/module.h>
39 #include <linux/string.h>
40 #include <linux/errno.h>
41 #include <linux/blkdev.h>
42 #include <linux/platform_device.h>
43 #include <linux/spinlock.h>
44 #include <linux/moduleparam.h>
45 #include <linux/firmware.h>
46 #include <linux/dma-mapping.h>
47
48 MODULE_AUTHOR("Abhay Salunke <abhay_salunke@dell.com>");
49 MODULE_DESCRIPTION("Driver for updating BIOS image on DELL systems");
50 MODULE_LICENSE("GPL");
51 MODULE_VERSION("3.2");
52
53 #define BIOS_SCAN_LIMIT 0xffffffff
54 #define MAX_IMAGE_LENGTH 16
55 static struct _rbu_data {
56         void *image_update_buffer;
57         unsigned long image_update_buffer_size;
58         unsigned long bios_image_size;
59         int image_update_ordernum;
60         int dma_alloc;
61         spinlock_t lock;
62         unsigned long packet_read_count;
63         unsigned long num_packets;
64         unsigned long packetsize;
65         unsigned long imagesize;
66         int entry_created;
67 } rbu_data;
68
69 static char image_type[MAX_IMAGE_LENGTH + 1] = "mono";
70 module_param_string(image_type, image_type, sizeof (image_type), 0);
71 MODULE_PARM_DESC(image_type,
72         "BIOS image type. choose- mono or packet or init");
73
74 static unsigned long allocation_floor = 0x100000;
75 module_param(allocation_floor, ulong, 0644);
76 MODULE_PARM_DESC(allocation_floor,
77     "Minimum address for allocations when using Packet mode");
78
79 struct packet_data {
80         struct list_head list;
81         size_t length;
82         void *data;
83         int ordernum;
84 };
85
86 static struct packet_data packet_data_head;
87
88 static struct platform_device *rbu_device;
89 static int context;
90 static dma_addr_t dell_rbu_dmaaddr;
91
92 static void init_packet_head(void)
93 {
94         INIT_LIST_HEAD(&packet_data_head.list);
95         rbu_data.packet_read_count = 0;
96         rbu_data.num_packets = 0;
97         rbu_data.packetsize = 0;
98         rbu_data.imagesize = 0;
99 }
100
101 static int create_packet(void *data, size_t length)
102 {
103         struct packet_data *newpacket;
104         int ordernum = 0;
105         int retval = 0;
106         unsigned int packet_array_size = 0;
107         void **invalid_addr_packet_array = NULL;
108         void *packet_data_temp_buf = NULL;
109         unsigned int idx = 0;
110
111         pr_debug("create_packet: entry \n");
112
113         if (!rbu_data.packetsize) {
114                 pr_debug("create_packet: packetsize not specified\n");
115                 retval = -EINVAL;
116                 goto out_noalloc;
117         }
118
119         spin_unlock(&rbu_data.lock);
120
121         newpacket = kzalloc(sizeof (struct packet_data), GFP_KERNEL);
122
123         if (!newpacket) {
124                 printk(KERN_WARNING
125                         "dell_rbu:%s: failed to allocate new "
126                         "packet\n", __func__);
127                 retval = -ENOMEM;
128                 spin_lock(&rbu_data.lock);
129                 goto out_noalloc;
130         }
131
132         ordernum = get_order(length);
133
134         /*
135          * BIOS errata mean we cannot allocate packets below 1MB or they will
136          * be overwritten by BIOS.
137          *
138          * array to temporarily hold packets
139          * that are below the allocation floor
140          *
141          * NOTE: very simplistic because we only need the floor to be at 1MB
142          *       due to BIOS errata. This shouldn't be used for higher floors
143          *       or you will run out of mem trying to allocate the array.
144          */
145         packet_array_size = max(
146                         (unsigned int)(allocation_floor / rbu_data.packetsize),
147                         (unsigned int)1);
148         invalid_addr_packet_array = kzalloc(packet_array_size * sizeof(void*),
149                                                 GFP_KERNEL);
150
151         if (!invalid_addr_packet_array) {
152                 printk(KERN_WARNING
153                         "dell_rbu:%s: failed to allocate "
154                         "invalid_addr_packet_array \n",
155                         __func__);
156                 retval = -ENOMEM;
157                 spin_lock(&rbu_data.lock);
158                 goto out_alloc_packet;
159         }
160
161         while (!packet_data_temp_buf) {
162                 packet_data_temp_buf = (unsigned char *)
163                         __get_free_pages(GFP_KERNEL, ordernum);
164                 if (!packet_data_temp_buf) {
165                         printk(KERN_WARNING
166                                 "dell_rbu:%s: failed to allocate new "
167                                 "packet\n", __func__);
168                         retval = -ENOMEM;
169                         spin_lock(&rbu_data.lock);
170                         goto out_alloc_packet_array;
171                 }
172
173                 if ((unsigned long)virt_to_phys(packet_data_temp_buf)
174                                 < allocation_floor) {
175                         pr_debug("packet 0x%lx below floor at 0x%lx.\n",
176                                         (unsigned long)virt_to_phys(
177                                                 packet_data_temp_buf),
178                                         allocation_floor);
179                         invalid_addr_packet_array[idx++] = packet_data_temp_buf;
180                         packet_data_temp_buf = NULL;
181                 }
182         }
183         spin_lock(&rbu_data.lock);
184
185         newpacket->data = packet_data_temp_buf;
186
187         pr_debug("create_packet: newpacket at physical addr %lx\n",
188                 (unsigned long)virt_to_phys(newpacket->data));
189
190         /* packets may not have fixed size */
191         newpacket->length = length;
192         newpacket->ordernum = ordernum;
193         ++rbu_data.num_packets;
194
195         /* initialize the newly created packet headers */
196         INIT_LIST_HEAD(&newpacket->list);
197         list_add_tail(&newpacket->list, &packet_data_head.list);
198
199         memcpy(newpacket->data, data, length);
200
201         pr_debug("create_packet: exit \n");
202
203 out_alloc_packet_array:
204         /* always free packet array */
205         for (;idx>0;idx--) {
206                 pr_debug("freeing unused packet below floor 0x%lx.\n",
207                         (unsigned long)virt_to_phys(
208                                 invalid_addr_packet_array[idx-1]));
209                 free_pages((unsigned long)invalid_addr_packet_array[idx-1],
210                         ordernum);
211         }
212         kfree(invalid_addr_packet_array);
213
214 out_alloc_packet:
215         /* if error, free data */
216         if (retval)
217                 kfree(newpacket);
218
219 out_noalloc:
220         return retval;
221 }
222
223 static int packetize_data(const u8 *data, size_t length)
224 {
225         int rc = 0;
226         int done = 0;
227         int packet_length;
228         u8 *temp;
229         u8 *end = (u8 *) data + length;
230         pr_debug("packetize_data: data length %zd\n", length);
231         if (!rbu_data.packetsize) {
232                 printk(KERN_WARNING
233                         "dell_rbu: packetsize not specified\n");
234                 return -EIO;
235         }
236
237         temp = (u8 *) data;
238
239         /* packetize the hunk */
240         while (!done) {
241                 if ((temp + rbu_data.packetsize) < end)
242                         packet_length = rbu_data.packetsize;
243                 else {
244                         /* this is the last packet */
245                         packet_length = end - temp;
246                         done = 1;
247                 }
248
249                 if ((rc = create_packet(temp, packet_length)))
250                         return rc;
251
252                 pr_debug("%p:%td\n", temp, (end - temp));
253                 temp += packet_length;
254         }
255
256         rbu_data.imagesize = length;
257
258         return rc;
259 }
260
261 static int do_packet_read(char *data, struct list_head *ptemp_list,
262         int length, int bytes_read, int *list_read_count)
263 {
264         void *ptemp_buf;
265         struct packet_data *newpacket = NULL;
266         int bytes_copied = 0;
267         int j = 0;
268
269         newpacket = list_entry(ptemp_list, struct packet_data, list);
270         *list_read_count += newpacket->length;
271
272         if (*list_read_count > bytes_read) {
273                 /* point to the start of unread data */
274                 j = newpacket->length - (*list_read_count - bytes_read);
275                 /* point to the offset in the packet buffer */
276                 ptemp_buf = (u8 *) newpacket->data + j;
277                 /*
278                  * check if there is enough room in
279                  * * the incoming buffer
280                  */
281                 if (length > (*list_read_count - bytes_read))
282                         /*
283                          * copy what ever is there in this
284                          * packet and move on
285                          */
286                         bytes_copied = (*list_read_count - bytes_read);
287                 else
288                         /* copy the remaining */
289                         bytes_copied = length;
290                 memcpy(data, ptemp_buf, bytes_copied);
291         }
292         return bytes_copied;
293 }
294
295 static int packet_read_list(char *data, size_t * pread_length)
296 {
297         struct list_head *ptemp_list;
298         int temp_count = 0;
299         int bytes_copied = 0;
300         int bytes_read = 0;
301         int remaining_bytes = 0;
302         char *pdest = data;
303
304         /* check if we have any packets */
305         if (0 == rbu_data.num_packets)
306                 return -ENOMEM;
307
308         remaining_bytes = *pread_length;
309         bytes_read = rbu_data.packet_read_count;
310
311         ptemp_list = (&packet_data_head.list)->next;
312         while (!list_empty(ptemp_list)) {
313                 bytes_copied = do_packet_read(pdest, ptemp_list,
314                         remaining_bytes, bytes_read, &temp_count);
315                 remaining_bytes -= bytes_copied;
316                 bytes_read += bytes_copied;
317                 pdest += bytes_copied;
318                 /*
319                  * check if we reached end of buffer before reaching the
320                  * last packet
321                  */
322                 if (remaining_bytes == 0)
323                         break;
324
325                 ptemp_list = ptemp_list->next;
326         }
327         /*finally set the bytes read */
328         *pread_length = bytes_read - rbu_data.packet_read_count;
329         rbu_data.packet_read_count = bytes_read;
330         return 0;
331 }
332
333 static void packet_empty_list(void)
334 {
335         struct list_head *ptemp_list;
336         struct list_head *pnext_list;
337         struct packet_data *newpacket;
338
339         ptemp_list = (&packet_data_head.list)->next;
340         while (!list_empty(ptemp_list)) {
341                 newpacket =
342                         list_entry(ptemp_list, struct packet_data, list);
343                 pnext_list = ptemp_list->next;
344                 list_del(ptemp_list);
345                 ptemp_list = pnext_list;
346                 /*
347                  * zero out the RBU packet memory before freeing
348                  * to make sure there are no stale RBU packets left in memory
349                  */
350                 memset(newpacket->data, 0, rbu_data.packetsize);
351                 free_pages((unsigned long) newpacket->data,
352                         newpacket->ordernum);
353                 kfree(newpacket);
354         }
355         rbu_data.packet_read_count = 0;
356         rbu_data.num_packets = 0;
357         rbu_data.imagesize = 0;
358 }
359
360 /*
361  * img_update_free: Frees the buffer allocated for storing BIOS image
362  * Always called with lock held and returned with lock held
363  */
364 static void img_update_free(void)
365 {
366         if (!rbu_data.image_update_buffer)
367                 return;
368         /*
369          * zero out this buffer before freeing it to get rid of any stale
370          * BIOS image copied in memory.
371          */
372         memset(rbu_data.image_update_buffer, 0,
373                 rbu_data.image_update_buffer_size);
374         if (rbu_data.dma_alloc == 1)
375                 dma_free_coherent(NULL, rbu_data.bios_image_size,
376                         rbu_data.image_update_buffer, dell_rbu_dmaaddr);
377         else
378                 free_pages((unsigned long) rbu_data.image_update_buffer,
379                         rbu_data.image_update_ordernum);
380
381         /*
382          * Re-initialize the rbu_data variables after a free
383          */
384         rbu_data.image_update_ordernum = -1;
385         rbu_data.image_update_buffer = NULL;
386         rbu_data.image_update_buffer_size = 0;
387         rbu_data.bios_image_size = 0;
388         rbu_data.dma_alloc = 0;
389 }
390
391 /*
392  * img_update_realloc: This function allocates the contiguous pages to
393  * accommodate the requested size of data. The memory address and size
394  * values are stored globally and on every call to this function the new
395  * size is checked to see if more data is required than the existing size.
396  * If true the previous memory is freed and new allocation is done to
397  * accommodate the new size. If the incoming size is less then than the
398  * already allocated size, then that memory is reused. This function is
399  * called with lock held and returns with lock held.
400  */
401 static int img_update_realloc(unsigned long size)
402 {
403         unsigned char *image_update_buffer = NULL;
404         unsigned long rc;
405         unsigned long img_buf_phys_addr;
406         int ordernum;
407         int dma_alloc = 0;
408
409         /*
410          * check if the buffer of sufficient size has been
411          * already allocated
412          */
413         if (rbu_data.image_update_buffer_size >= size) {
414                 /*
415                  * check for corruption
416                  */
417                 if ((size != 0) && (rbu_data.image_update_buffer == NULL)) {
418                         printk(KERN_ERR "dell_rbu:%s: corruption "
419                                 "check failed\n", __func__);
420                         return -EINVAL;
421                 }
422                 /*
423                  * we have a valid pre-allocated buffer with
424                  * sufficient size
425                  */
426                 return 0;
427         }
428
429         /*
430          * free any previously allocated buffer
431          */
432         img_update_free();
433
434         spin_unlock(&rbu_data.lock);
435
436         ordernum = get_order(size);
437         image_update_buffer =
438                 (unsigned char *) __get_free_pages(GFP_KERNEL, ordernum);
439
440         img_buf_phys_addr =
441                 (unsigned long) virt_to_phys(image_update_buffer);
442
443         if (img_buf_phys_addr > BIOS_SCAN_LIMIT) {
444                 free_pages((unsigned long) image_update_buffer, ordernum);
445                 ordernum = -1;
446                 image_update_buffer = dma_alloc_coherent(NULL, size,
447                         &dell_rbu_dmaaddr, GFP_KERNEL);
448                 dma_alloc = 1;
449         }
450
451         spin_lock(&rbu_data.lock);
452
453         if (image_update_buffer != NULL) {
454                 rbu_data.image_update_buffer = image_update_buffer;
455                 rbu_data.image_update_buffer_size = size;
456                 rbu_data.bios_image_size =
457                         rbu_data.image_update_buffer_size;
458                 rbu_data.image_update_ordernum = ordernum;
459                 rbu_data.dma_alloc = dma_alloc;
460                 rc = 0;
461         } else {
462                 pr_debug("Not enough memory for image update:"
463                         "size = %ld\n", size);
464                 rc = -ENOMEM;
465         }
466
467         return rc;
468 }
469
470 static ssize_t read_packet_data(char *buffer, loff_t pos, size_t count)
471 {
472         int retval;
473         size_t bytes_left;
474         size_t data_length;
475         char *ptempBuf = buffer;
476
477         /* check to see if we have something to return */
478         if (rbu_data.num_packets == 0) {
479                 pr_debug("read_packet_data: no packets written\n");
480                 retval = -ENOMEM;
481                 goto read_rbu_data_exit;
482         }
483
484         if (pos > rbu_data.imagesize) {
485                 retval = 0;
486                 printk(KERN_WARNING "dell_rbu:read_packet_data: "
487                         "data underrun\n");
488                 goto read_rbu_data_exit;
489         }
490
491         bytes_left = rbu_data.imagesize - pos;
492         data_length = min(bytes_left, count);
493
494         if ((retval = packet_read_list(ptempBuf, &data_length)) < 0)
495                 goto read_rbu_data_exit;
496
497         if ((pos + count) > rbu_data.imagesize) {
498                 rbu_data.packet_read_count = 0;
499                 /* this was the last copy */
500                 retval = bytes_left;
501         } else
502                 retval = count;
503
504       read_rbu_data_exit:
505         return retval;
506 }
507
508 static ssize_t read_rbu_mono_data(char *buffer, loff_t pos, size_t count)
509 {
510         /* check to see if we have something to return */
511         if ((rbu_data.image_update_buffer == NULL) ||
512                 (rbu_data.bios_image_size == 0)) {
513                 pr_debug("read_rbu_data_mono: image_update_buffer %p ,"
514                         "bios_image_size %lu\n",
515                         rbu_data.image_update_buffer,
516                         rbu_data.bios_image_size);
517                 return -ENOMEM;
518         }
519
520         return memory_read_from_buffer(buffer, count, &pos,
521                         rbu_data.image_update_buffer, rbu_data.bios_image_size);
522 }
523
524 static ssize_t read_rbu_data(struct kobject *kobj,
525                              struct bin_attribute *bin_attr,
526                              char *buffer, loff_t pos, size_t count)
527 {
528         ssize_t ret_count = 0;
529
530         spin_lock(&rbu_data.lock);
531
532         if (!strcmp(image_type, "mono"))
533                 ret_count = read_rbu_mono_data(buffer, pos, count);
534         else if (!strcmp(image_type, "packet"))
535                 ret_count = read_packet_data(buffer, pos, count);
536         else
537                 pr_debug("read_rbu_data: invalid image type specified\n");
538
539         spin_unlock(&rbu_data.lock);
540         return ret_count;
541 }
542
543 static void callbackfn_rbu(const struct firmware *fw, void *context)
544 {
545         rbu_data.entry_created = 0;
546
547         if (!fw || !fw->size)
548                 return;
549
550         spin_lock(&rbu_data.lock);
551         if (!strcmp(image_type, "mono")) {
552                 if (!img_update_realloc(fw->size))
553                         memcpy(rbu_data.image_update_buffer,
554                                 fw->data, fw->size);
555         } else if (!strcmp(image_type, "packet")) {
556                 /*
557                  * we need to free previous packets if a
558                  * new hunk of packets needs to be downloaded
559                  */
560                 packet_empty_list();
561                 if (packetize_data(fw->data, fw->size))
562                         /* Incase something goes wrong when we are
563                          * in middle of packetizing the data, we
564                          * need to free up whatever packets might
565                          * have been created before we quit.
566                          */
567                         packet_empty_list();
568         } else
569                 pr_debug("invalid image type specified.\n");
570         spin_unlock(&rbu_data.lock);
571 }
572
573 static ssize_t read_rbu_image_type(struct kobject *kobj,
574                                    struct bin_attribute *bin_attr,
575                                    char *buffer, loff_t pos, size_t count)
576 {
577         int size = 0;
578         if (!pos)
579                 size = sprintf(buffer, "%s\n", image_type);
580         return size;
581 }
582
583 static ssize_t write_rbu_image_type(struct kobject *kobj,
584                                     struct bin_attribute *bin_attr,
585                                     char *buffer, loff_t pos, size_t count)
586 {
587         int rc = count;
588         int req_firm_rc = 0;
589         int i;
590         spin_lock(&rbu_data.lock);
591         /*
592          * Find the first newline or space
593          */
594         for (i = 0; i < count; ++i)
595                 if (buffer[i] == '\n' || buffer[i] == ' ') {
596                         buffer[i] = '\0';
597                         break;
598                 }
599         if (i == count)
600                 buffer[count] = '\0';
601
602         if (strstr(buffer, "mono"))
603                 strcpy(image_type, "mono");
604         else if (strstr(buffer, "packet"))
605                 strcpy(image_type, "packet");
606         else if (strstr(buffer, "init")) {
607                 /*
608                  * If due to the user error the driver gets in a bad
609                  * state where even though it is loaded , the
610                  * /sys/class/firmware/dell_rbu entries are missing.
611                  * to cover this situation the user can recreate entries
612                  * by writing init to image_type.
613                  */
614                 if (!rbu_data.entry_created) {
615                         spin_unlock(&rbu_data.lock);
616                         req_firm_rc = request_firmware_nowait(THIS_MODULE,
617                                 FW_ACTION_NOHOTPLUG, "dell_rbu",
618                                 &rbu_device->dev, &context,
619                                 callbackfn_rbu);
620                         if (req_firm_rc) {
621                                 printk(KERN_ERR
622                                         "dell_rbu:%s request_firmware_nowait"
623                                         " failed %d\n", __func__, rc);
624                                 rc = -EIO;
625                         } else
626                                 rbu_data.entry_created = 1;
627
628                         spin_lock(&rbu_data.lock);
629                 }
630         } else {
631                 printk(KERN_WARNING "dell_rbu: image_type is invalid\n");
632                 spin_unlock(&rbu_data.lock);
633                 return -EINVAL;
634         }
635
636         /* we must free all previous allocations */
637         packet_empty_list();
638         img_update_free();
639         spin_unlock(&rbu_data.lock);
640
641         return rc;
642 }
643
644 static ssize_t read_rbu_packet_size(struct kobject *kobj,
645                                     struct bin_attribute *bin_attr,
646                                     char *buffer, loff_t pos, size_t count)
647 {
648         int size = 0;
649         if (!pos) {
650                 spin_lock(&rbu_data.lock);
651                 size = sprintf(buffer, "%lu\n", rbu_data.packetsize);
652                 spin_unlock(&rbu_data.lock);
653         }
654         return size;
655 }
656
657 static ssize_t write_rbu_packet_size(struct kobject *kobj,
658                                      struct bin_attribute *bin_attr,
659                                      char *buffer, loff_t pos, size_t count)
660 {
661         unsigned long temp;
662         spin_lock(&rbu_data.lock);
663         packet_empty_list();
664         sscanf(buffer, "%lu", &temp);
665         if (temp < 0xffffffff)
666                 rbu_data.packetsize = temp;
667
668         spin_unlock(&rbu_data.lock);
669         return count;
670 }
671
672 static struct bin_attribute rbu_data_attr = {
673         .attr = {.name = "data", .mode = 0444},
674         .read = read_rbu_data,
675 };
676
677 static struct bin_attribute rbu_image_type_attr = {
678         .attr = {.name = "image_type", .mode = 0644},
679         .read = read_rbu_image_type,
680         .write = write_rbu_image_type,
681 };
682
683 static struct bin_attribute rbu_packet_size_attr = {
684         .attr = {.name = "packet_size", .mode = 0644},
685         .read = read_rbu_packet_size,
686         .write = write_rbu_packet_size,
687 };
688
689 static int __init dcdrbu_init(void)
690 {
691         int rc;
692         spin_lock_init(&rbu_data.lock);
693
694         init_packet_head();
695         rbu_device = platform_device_register_simple("dell_rbu", -1, NULL, 0);
696         if (IS_ERR(rbu_device)) {
697                 printk(KERN_ERR
698                         "dell_rbu:%s:platform_device_register_simple "
699                         "failed\n", __func__);
700                 return PTR_ERR(rbu_device);
701         }
702
703         rc = sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
704         if (rc)
705                 goto out_devreg;
706         rc = sysfs_create_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
707         if (rc)
708                 goto out_data;
709         rc = sysfs_create_bin_file(&rbu_device->dev.kobj,
710                 &rbu_packet_size_attr);
711         if (rc)
712                 goto out_imtype;
713
714         rbu_data.entry_created = 0;
715         return 0;
716
717 out_imtype:
718         sysfs_remove_bin_file(&rbu_device->dev.kobj, &rbu_image_type_attr);
719 out_data:
720         sysfs_remove_bin_file(&rbu_device->dev.kobj, &rbu_data_attr);
721 out_devreg:
722         platform_device_unregister(rbu_device);
723         return rc;
724 }
725
726 static __exit void dcdrbu_exit(void)
727 {
728         spin_lock(&rbu_data.lock);
729         packet_empty_list();
730         img_update_free();
731         spin_unlock(&rbu_data.lock);
732         platform_device_unregister(rbu_device);
733 }
734
735 module_exit(dcdrbu_exit);
736 module_init(dcdrbu_init);
737
738 /* vim:noet:ts=8:sw=8
739 */