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bsdacct: fix and add comments around acct_process()
[linux-2.6/mini2440.git] / drivers / mtd / mtdchar.c
blobaef9f4b687c9fdfafc7eb5fddfc6cdb98ea28cc1
1 /*
2 * $Id: mtdchar.c,v 1.76 2005/11/07 11:14:20 gleixner Exp $
3 *
4 * Character-device access to raw MTD devices.
5 *
6 */
7
8 #include <linux/device.h>
9 #include <linux/fs.h>
10 #include <linux/mm.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
16 #include <linux/sched.h>
17 #include <linux/smp_lock.h>
18
19 #include <linux/mtd/mtd.h>
20 #include <linux/mtd/compatmac.h>
21
22 #include <asm/uaccess.h>
23
24 static struct class *mtd_class;
25
26 static void mtd_notify_add(struct mtd_info* mtd)
27 {
28 if (!mtd)
29 return;
30
31 device_create_drvdata(mtd_class, NULL,
32 MKDEV(MTD_CHAR_MAJOR, mtd->index*2),
33 NULL, "mtd%d", mtd->index);
34
35 device_create_drvdata(mtd_class, NULL,
36 MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1),
37 NULL, "mtd%dro", mtd->index);
38 }
39
40 static void mtd_notify_remove(struct mtd_info* mtd)
41 {
42 if (!mtd)
43 return;
44
45 device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2));
46 device_destroy(mtd_class, MKDEV(MTD_CHAR_MAJOR, mtd->index*2+1));
47 }
48
49 static struct mtd_notifier notifier = {
50 .add = mtd_notify_add,
51 .remove = mtd_notify_remove,
52 };
53
54 /*
55 * Data structure to hold the pointer to the mtd device as well
56 * as mode information ofr various use cases.
57 */
58 struct mtd_file_info {
59 struct mtd_info *mtd;
60 enum mtd_file_modes mode;
61 };
62
63 static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
64 {
65 struct mtd_file_info *mfi = file->private_data;
66 struct mtd_info *mtd = mfi->mtd;
67
68 switch (orig) {
69 case SEEK_SET:
70 break;
71 case SEEK_CUR:
72 offset += file->f_pos;
73 break;
74 case SEEK_END:
75 offset += mtd->size;
76 break;
77 default:
78 return -EINVAL;
79 }
80
81 if (offset >= 0 && offset <= mtd->size)
82 return file->f_pos = offset;
83
84 return -EINVAL;
85 }
86
87
88
89 static int mtd_open(struct inode *inode, struct file *file)
90 {
91 int minor = iminor(inode);
92 int devnum = minor >> 1;
93 int ret = 0;
94 struct mtd_info *mtd;
95 struct mtd_file_info *mfi;
96
97 DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");
98
99 if (devnum >= MAX_MTD_DEVICES)
100 return -ENODEV;
101
102 /* You can't open the RO devices RW */
103 if ((file->f_mode & 2) && (minor & 1))
104 return -EACCES;
105
106 lock_kernel();
107 mtd = get_mtd_device(NULL, devnum);
108
109 if (IS_ERR(mtd)) {
110 ret = PTR_ERR(mtd);
111 goto out;
112 }
113
114 if (MTD_ABSENT == mtd->type) {
115 put_mtd_device(mtd);
116 ret = -ENODEV;
117 goto out;
118 }
119
120 /* You can't open it RW if it's not a writeable device */
121 if ((file->f_mode & 2) && !(mtd->flags & MTD_WRITEABLE)) {
122 put_mtd_device(mtd);
123 ret = -EACCES;
124 goto out;
125 }
126
127 mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
128 if (!mfi) {
129 put_mtd_device(mtd);
130 ret = -ENOMEM;
131 goto out;
132 }
133 mfi->mtd = mtd;
134 file->private_data = mfi;
135
136 out:
137 unlock_kernel();
138 return ret;
139 } /* mtd_open */
140
141 /*====================================================================*/
142
143 static int mtd_close(struct inode *inode, struct file *file)
144 {
145 struct mtd_file_info *mfi = file->private_data;
146 struct mtd_info *mtd = mfi->mtd;
147
148 DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");
149
150 /* Only sync if opened RW */
151 if ((file->f_mode & 2) && mtd->sync)
152 mtd->sync(mtd);
153
154 put_mtd_device(mtd);
155 file->private_data = NULL;
156 kfree(mfi);
157
158 return 0;
159 } /* mtd_close */
160
161 /* FIXME: This _really_ needs to die. In 2.5, we should lock the
162 userspace buffer down and use it directly with readv/writev.
163 */
164 #define MAX_KMALLOC_SIZE 0x20000
165
166 static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
167 {
168 struct mtd_file_info *mfi = file->private_data;
169 struct mtd_info *mtd = mfi->mtd;
170 size_t retlen=0;
171 size_t total_retlen=0;
172 int ret=0;
173 int len;
174 char *kbuf;
175
176 DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");
177
178 if (*ppos + count > mtd->size)
179 count = mtd->size - *ppos;
180
181 if (!count)
182 return 0;
183
184 /* FIXME: Use kiovec in 2.5 to lock down the user's buffers
185 and pass them directly to the MTD functions */
186
187 if (count > MAX_KMALLOC_SIZE)
188 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
189 else
190 kbuf=kmalloc(count, GFP_KERNEL);
191
192 if (!kbuf)
193 return -ENOMEM;
194
195 while (count) {
196
197 if (count > MAX_KMALLOC_SIZE)
198 len = MAX_KMALLOC_SIZE;
199 else
200 len = count;
201
202 switch (mfi->mode) {
203 case MTD_MODE_OTP_FACTORY:
204 ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
205 break;
206 case MTD_MODE_OTP_USER:
207 ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
208 break;
209 case MTD_MODE_RAW:
210 {
211 struct mtd_oob_ops ops;
212
213 ops.mode = MTD_OOB_RAW;
214 ops.datbuf = kbuf;
215 ops.oobbuf = NULL;
216 ops.len = len;
217
218 ret = mtd->read_oob(mtd, *ppos, &ops);
219 retlen = ops.retlen;
220 break;
221 }
222 default:
223 ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
224 }
225 /* Nand returns -EBADMSG on ecc errors, but it returns
226 * the data. For our userspace tools it is important
227 * to dump areas with ecc errors !
228 * For kernel internal usage it also might return -EUCLEAN
229 * to signal the caller that a bitflip has occured and has
230 * been corrected by the ECC algorithm.
231 * Userspace software which accesses NAND this way
232 * must be aware of the fact that it deals with NAND
233 */
234 if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
235 *ppos += retlen;
236 if (copy_to_user(buf, kbuf, retlen)) {
237 kfree(kbuf);
238 return -EFAULT;
239 }
240 else
241 total_retlen += retlen;
242
243 count -= retlen;
244 buf += retlen;
245 if (retlen == 0)
246 count = 0;
247 }
248 else {
249 kfree(kbuf);
250 return ret;
251 }
252
253 }
254
255 kfree(kbuf);
256 return total_retlen;
257 } /* mtd_read */
258
259 static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
260 {
261 struct mtd_file_info *mfi = file->private_data;
262 struct mtd_info *mtd = mfi->mtd;
263 char *kbuf;
264 size_t retlen;
265 size_t total_retlen=0;
266 int ret=0;
267 int len;
268
269 DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");
270
271 if (*ppos == mtd->size)
272 return -ENOSPC;
273
274 if (*ppos + count > mtd->size)
275 count = mtd->size - *ppos;
276
277 if (!count)
278 return 0;
279
280 if (count > MAX_KMALLOC_SIZE)
281 kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
282 else
283 kbuf=kmalloc(count, GFP_KERNEL);
284
285 if (!kbuf)
286 return -ENOMEM;
287
288 while (count) {
289
290 if (count > MAX_KMALLOC_SIZE)
291 len = MAX_KMALLOC_SIZE;
292 else
293 len = count;
294
295 if (copy_from_user(kbuf, buf, len)) {
296 kfree(kbuf);
297 return -EFAULT;
298 }
299
300 switch (mfi->mode) {
301 case MTD_MODE_OTP_FACTORY:
302 ret = -EROFS;
303 break;
304 case MTD_MODE_OTP_USER:
305 if (!mtd->write_user_prot_reg) {
306 ret = -EOPNOTSUPP;
307 break;
308 }
309 ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
310 break;
311
312 case MTD_MODE_RAW:
313 {
314 struct mtd_oob_ops ops;
315
316 ops.mode = MTD_OOB_RAW;
317 ops.datbuf = kbuf;
318 ops.oobbuf = NULL;
319 ops.len = len;
320
321 ret = mtd->write_oob(mtd, *ppos, &ops);
322 retlen = ops.retlen;
323 break;
324 }
325
326 default:
327 ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
328 }
329 if (!ret) {
330 *ppos += retlen;
331 total_retlen += retlen;
332 count -= retlen;
333 buf += retlen;
334 }
335 else {
336 kfree(kbuf);
337 return ret;
338 }
339 }
340
341 kfree(kbuf);
342 return total_retlen;
343 } /* mtd_write */
344
345 /*======================================================================
346
347 IOCTL calls for getting device parameters.
348
349 ======================================================================*/
350 static void mtdchar_erase_callback (struct erase_info *instr)
351 {
352 wake_up((wait_queue_head_t *)instr->priv);
353 }
354
355 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
356 static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
357 {
358 struct mtd_info *mtd = mfi->mtd;
359 int ret = 0;
360
361 switch (mode) {
362 case MTD_OTP_FACTORY:
363 if (!mtd->read_fact_prot_reg)
364 ret = -EOPNOTSUPP;
365 else
366 mfi->mode = MTD_MODE_OTP_FACTORY;
367 break;
368 case MTD_OTP_USER:
369 if (!mtd->read_fact_prot_reg)
370 ret = -EOPNOTSUPP;
371 else
372 mfi->mode = MTD_MODE_OTP_USER;
373 break;
374 default:
375 ret = -EINVAL;
376 case MTD_OTP_OFF:
377 break;
378 }
379 return ret;
380 }
381 #else
382 # define otp_select_filemode(f,m) -EOPNOTSUPP
383 #endif
384
385 static int mtd_ioctl(struct inode *inode, struct file *file,
386 u_int cmd, u_long arg)
387 {
388 struct mtd_file_info *mfi = file->private_data;
389 struct mtd_info *mtd = mfi->mtd;
390 void __user *argp = (void __user *)arg;
391 int ret = 0;
392 u_long size;
393 struct mtd_info_user info;
394
395 DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");
396
397 size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
398 if (cmd & IOC_IN) {
399 if (!access_ok(VERIFY_READ, argp, size))
400 return -EFAULT;
401 }
402 if (cmd & IOC_OUT) {
403 if (!access_ok(VERIFY_WRITE, argp, size))
404 return -EFAULT;
405 }
406
407 switch (cmd) {
408 case MEMGETREGIONCOUNT:
409 if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
410 return -EFAULT;
411 break;
412
413 case MEMGETREGIONINFO:
414 {
415 struct region_info_user ur;
416
417 if (copy_from_user(&ur, argp, sizeof(struct region_info_user)))
418 return -EFAULT;
419
420 if (ur.regionindex >= mtd->numeraseregions)
421 return -EINVAL;
422 if (copy_to_user(argp, &(mtd->eraseregions[ur.regionindex]),
423 sizeof(struct mtd_erase_region_info)))
424 return -EFAULT;
425 break;
426 }
427
428 case MEMGETINFO:
429 info.type = mtd->type;
430 info.flags = mtd->flags;
431 info.size = mtd->size;
432 info.erasesize = mtd->erasesize;
433 info.writesize = mtd->writesize;
434 info.oobsize = mtd->oobsize;
435 /* The below fields are obsolete */
436 info.ecctype = -1;
437 info.eccsize = 0;
438 if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
439 return -EFAULT;
440 break;
441
442 case MEMERASE:
443 {
444 struct erase_info *erase;
445
446 if(!(file->f_mode & 2))
447 return -EPERM;
448
449 erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
450 if (!erase)
451 ret = -ENOMEM;
452 else {
453 wait_queue_head_t waitq;
454 DECLARE_WAITQUEUE(wait, current);
455
456 init_waitqueue_head(&waitq);
457
458 if (copy_from_user(&erase->addr, argp,
459 sizeof(struct erase_info_user))) {
460 kfree(erase);
461 return -EFAULT;
462 }
463 erase->mtd = mtd;
464 erase->callback = mtdchar_erase_callback;
465 erase->priv = (unsigned long)&waitq;
466
467 /*
468 FIXME: Allow INTERRUPTIBLE. Which means
469 not having the wait_queue head on the stack.
470
471 If the wq_head is on the stack, and we
472 leave because we got interrupted, then the
473 wq_head is no longer there when the
474 callback routine tries to wake us up.
475 */
476 ret = mtd->erase(mtd, erase);
477 if (!ret) {
478 set_current_state(TASK_UNINTERRUPTIBLE);
479 add_wait_queue(&waitq, &wait);
480 if (erase->state != MTD_ERASE_DONE &&
481 erase->state != MTD_ERASE_FAILED)
482 schedule();
483 remove_wait_queue(&waitq, &wait);
484 set_current_state(TASK_RUNNING);
485
486 ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
487 }
488 kfree(erase);
489 }
490 break;
491 }
492
493 case MEMWRITEOOB:
494 {
495 struct mtd_oob_buf buf;
496 struct mtd_oob_ops ops;
497 uint32_t retlen;
498
499 if(!(file->f_mode & 2))
500 return -EPERM;
501
502 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
503 return -EFAULT;
504
505 if (buf.length > 4096)
506 return -EINVAL;
507
508 if (!mtd->write_oob)
509 ret = -EOPNOTSUPP;
510 else
511 ret = access_ok(VERIFY_READ, buf.ptr,
512 buf.length) ? 0 : EFAULT;
513
514 if (ret)
515 return ret;
516
517 ops.ooblen = buf.length;
518 ops.ooboffs = buf.start & (mtd->oobsize - 1);
519 ops.datbuf = NULL;
520 ops.mode = MTD_OOB_PLACE;
521
522 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
523 return -EINVAL;
524
525 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
526 if (!ops.oobbuf)
527 return -ENOMEM;
528
529 if (copy_from_user(ops.oobbuf, buf.ptr, buf.length)) {
530 kfree(ops.oobbuf);
531 return -EFAULT;
532 }
533
534 buf.start &= ~(mtd->oobsize - 1);
535 ret = mtd->write_oob(mtd, buf.start, &ops);
536
537 if (ops.oobretlen > 0xFFFFFFFFU)
538 ret = -EOVERFLOW;
539 retlen = ops.oobretlen;
540 if (copy_to_user(&((struct mtd_oob_buf *)argp)->length,
541 &retlen, sizeof(buf.length)))
542 ret = -EFAULT;
543
544 kfree(ops.oobbuf);
545 break;
546
547 }
548
549 case MEMREADOOB:
550 {
551 struct mtd_oob_buf buf;
552 struct mtd_oob_ops ops;
553
554 if (copy_from_user(&buf, argp, sizeof(struct mtd_oob_buf)))
555 return -EFAULT;
556
557 if (buf.length > 4096)
558 return -EINVAL;
559
560 if (!mtd->read_oob)
561 ret = -EOPNOTSUPP;
562 else
563 ret = access_ok(VERIFY_WRITE, buf.ptr,
564 buf.length) ? 0 : -EFAULT;
565 if (ret)
566 return ret;
567
568 ops.ooblen = buf.length;
569 ops.ooboffs = buf.start & (mtd->oobsize - 1);
570 ops.datbuf = NULL;
571 ops.mode = MTD_OOB_PLACE;
572
573 if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
574 return -EINVAL;
575
576 ops.oobbuf = kmalloc(buf.length, GFP_KERNEL);
577 if (!ops.oobbuf)
578 return -ENOMEM;
579
580 buf.start &= ~(mtd->oobsize - 1);
581 ret = mtd->read_oob(mtd, buf.start, &ops);
582
583 if (put_user(ops.oobretlen, (uint32_t __user *)argp))
584 ret = -EFAULT;
585 else if (ops.oobretlen && copy_to_user(buf.ptr, ops.oobbuf,
586 ops.oobretlen))
587 ret = -EFAULT;
588
589 kfree(ops.oobbuf);
590 break;
591 }
592
593 case MEMLOCK:
594 {
595 struct erase_info_user info;
596
597 if (copy_from_user(&info, argp, sizeof(info)))
598 return -EFAULT;
599
600 if (!mtd->lock)
601 ret = -EOPNOTSUPP;
602 else
603 ret = mtd->lock(mtd, info.start, info.length);
604 break;
605 }
606
607 case MEMUNLOCK:
608 {
609 struct erase_info_user info;
610
611 if (copy_from_user(&info, argp, sizeof(info)))
612 return -EFAULT;
613
614 if (!mtd->unlock)
615 ret = -EOPNOTSUPP;
616 else
617 ret = mtd->unlock(mtd, info.start, info.length);
618 break;
619 }
620
621 /* Legacy interface */
622 case MEMGETOOBSEL:
623 {
624 struct nand_oobinfo oi;
625
626 if (!mtd->ecclayout)
627 return -EOPNOTSUPP;
628 if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
629 return -EINVAL;
630
631 oi.useecc = MTD_NANDECC_AUTOPLACE;
632 memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
633 memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
634 sizeof(oi.oobfree));
635 oi.eccbytes = mtd->ecclayout->eccbytes;
636
637 if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
638 return -EFAULT;
639 break;
640 }
641
642 case MEMGETBADBLOCK:
643 {
644 loff_t offs;
645
646 if (copy_from_user(&offs, argp, sizeof(loff_t)))
647 return -EFAULT;
648 if (!mtd->block_isbad)
649 ret = -EOPNOTSUPP;
650 else
651 return mtd->block_isbad(mtd, offs);
652 break;
653 }
654
655 case MEMSETBADBLOCK:
656 {
657 loff_t offs;
658
659 if (copy_from_user(&offs, argp, sizeof(loff_t)))
660 return -EFAULT;
661 if (!mtd->block_markbad)
662 ret = -EOPNOTSUPP;
663 else
664 return mtd->block_markbad(mtd, offs);
665 break;
666 }
667
668 #if defined(CONFIG_MTD_OTP) || defined(CONFIG_MTD_ONENAND_OTP)
669 case OTPSELECT:
670 {
671 int mode;
672 if (copy_from_user(&mode, argp, sizeof(int)))
673 return -EFAULT;
674
675 mfi->mode = MTD_MODE_NORMAL;
676
677 ret = otp_select_filemode(mfi, mode);
678
679 file->f_pos = 0;
680 break;
681 }
682
683 case OTPGETREGIONCOUNT:
684 case OTPGETREGIONINFO:
685 {
686 struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
687 if (!buf)
688 return -ENOMEM;
689 ret = -EOPNOTSUPP;
690 switch (mfi->mode) {
691 case MTD_MODE_OTP_FACTORY:
692 if (mtd->get_fact_prot_info)
693 ret = mtd->get_fact_prot_info(mtd, buf, 4096);
694 break;
695 case MTD_MODE_OTP_USER:
696 if (mtd->get_user_prot_info)
697 ret = mtd->get_user_prot_info(mtd, buf, 4096);
698 break;
699 default:
700 break;
701 }
702 if (ret >= 0) {
703 if (cmd == OTPGETREGIONCOUNT) {
704 int nbr = ret / sizeof(struct otp_info);
705 ret = copy_to_user(argp, &nbr, sizeof(int));
706 } else
707 ret = copy_to_user(argp, buf, ret);
708 if (ret)
709 ret = -EFAULT;
710 }
711 kfree(buf);
712 break;
713 }
714
715 case OTPLOCK:
716 {
717 struct otp_info info;
718
719 if (mfi->mode != MTD_MODE_OTP_USER)
720 return -EINVAL;
721 if (copy_from_user(&info, argp, sizeof(info)))
722 return -EFAULT;
723 if (!mtd->lock_user_prot_reg)
724 return -EOPNOTSUPP;
725 ret = mtd->lock_user_prot_reg(mtd, info.start, info.length);
726 break;
727 }
728 #endif
729
730 case ECCGETLAYOUT:
731 {
732 if (!mtd->ecclayout)
733 return -EOPNOTSUPP;
734
735 if (copy_to_user(argp, mtd->ecclayout,
736 sizeof(struct nand_ecclayout)))
737 return -EFAULT;
738 break;
739 }
740
741 case ECCGETSTATS:
742 {
743 if (copy_to_user(argp, &mtd->ecc_stats,
744 sizeof(struct mtd_ecc_stats)))
745 return -EFAULT;
746 break;
747 }
748
749 case MTDFILEMODE:
750 {
751 mfi->mode = 0;
752
753 switch(arg) {
754 case MTD_MODE_OTP_FACTORY:
755 case MTD_MODE_OTP_USER:
756 ret = otp_select_filemode(mfi, arg);
757 break;
758
759 case MTD_MODE_RAW:
760 if (!mtd->read_oob || !mtd->write_oob)
761 return -EOPNOTSUPP;
762 mfi->mode = arg;
763
764 case MTD_MODE_NORMAL:
765 break;
766 default:
767 ret = -EINVAL;
768 }
769 file->f_pos = 0;
770 break;
771 }
772
773 default:
774 ret = -ENOTTY;
775 }
776
777 return ret;
778 } /* memory_ioctl */
779
780 static const struct file_operations mtd_fops = {
781 .owner = THIS_MODULE,
782 .llseek = mtd_lseek,
783 .read = mtd_read,
784 .write = mtd_write,
785 .ioctl = mtd_ioctl,
786 .open = mtd_open,
787 .release = mtd_close,
788 };
789
790 static int __init init_mtdchar(void)
791 {
792 if (register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops)) {
793 printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
794 MTD_CHAR_MAJOR);
795 return -EAGAIN;
796 }
797
798 mtd_class = class_create(THIS_MODULE, "mtd");
799
800 if (IS_ERR(mtd_class)) {
801 printk(KERN_ERR "Error creating mtd class.\n");
802 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
803 return PTR_ERR(mtd_class);
804 }
805
806 register_mtd_user(&notifier);
807 return 0;
808 }
809
810 static void __exit cleanup_mtdchar(void)
811 {
812 unregister_mtd_user(&notifier);
813 class_destroy(mtd_class);
814 unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
815 }
816
817 module_init(init_mtdchar);
818 module_exit(cleanup_mtdchar);
819
820
821 MODULE_LICENSE("GPL");
822 MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
823 MODULE_DESCRIPTION("Direct character-device access to MTD devices");
Support for the Chinese Samsung S3C2440 based development boards