aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/mtd/mtdcore.c
blob: a1b8b70d2d0a04d2a6a12b02e48440bc97eac23e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
/*
 * Core registration and callback routines for MTD
 * drivers and users.
 *
 * bdi bits are:
 * Copyright © 2006 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/timer.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/ioctl.h>
#include <linux/init.h>
#include <linux/mtd/compatmac.h>
#include <linux/proc_fs.h>
#include <linux/idr.h>
#include <linux/backing-dev.h>
#include <linux/gfp.h>

#include <linux/mtd/mtd.h>

#include "mtdcore.h"
/*
 * backing device capabilities for non-mappable devices (such as NAND flash)
 * - permits private mappings, copies are taken of the data
 */
struct backing_dev_info mtd_bdi_unmappable = {
	.capabilities	= BDI_CAP_MAP_COPY,
};

/*
 * backing device capabilities for R/O mappable devices (such as ROM)
 * - permits private mappings, copies are taken of the data
 * - permits non-writable shared mappings
 */
struct backing_dev_info mtd_bdi_ro_mappable = {
	.capabilities	= (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
			   BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
};

/*
 * backing device capabilities for writable mappable devices (such as RAM)
 * - permits private mappings, copies are taken of the data
 * - permits non-writable shared mappings
 */
struct backing_dev_info mtd_bdi_rw_mappable = {
	.capabilities	= (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
			   BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
			   BDI_CAP_WRITE_MAP),
};

static int mtd_cls_suspend(struct device *dev, pm_message_t state);
static int mtd_cls_resume(struct device *dev);

static struct class mtd_class = {
	.name = "mtd",
	.owner = THIS_MODULE,
	.suspend = mtd_cls_suspend,
	.resume = mtd_cls_resume,
};

static DEFINE_IDR(mtd_idr);

/* These are exported solely for the purpose of mtd_blkdevs.c. You
   should not use them for _anything_ else */
DEFINE_MUTEX(mtd_table_mutex);
EXPORT_SYMBOL_GPL(mtd_table_mutex);

struct mtd_info *__mtd_next_device(int i)
{
	return idr_get_next(&mtd_idr, &i);
}
EXPORT_SYMBOL_GPL(__mtd_next_device);

static LIST_HEAD(mtd_notifiers);


#if defined(CONFIG_MTD_CHAR) || defined(CONFIG_MTD_CHAR_MODULE)
#define MTD_DEVT(index) MKDEV(MTD_CHAR_MAJOR, (index)*2)
#else
#define MTD_DEVT(index) 0
#endif

/* REVISIT once MTD uses the driver model better, whoever allocates
 * the mtd_info will probably want to use the release() hook...
 */
static void mtd_release(struct device *dev)
{
	dev_t index = MTD_DEVT(dev_to_mtd(dev)->index);

	/* remove /dev/mtdXro node if needed */
	if (index)
		device_destroy(&mtd_class, index + 1);
}

static int mtd_cls_suspend(struct device *dev, pm_message_t state)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	if (mtd && mtd->suspend)
		return mtd->suspend(mtd);
	else
		return 0;
}

static int mtd_cls_resume(struct device *dev)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	
	if (mtd && mtd->resume)
		mtd->resume(mtd);
	return 0;
}

static ssize_t mtd_type_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	char *type;

	switch (mtd->type) {
	case MTD_ABSENT:
		type = "absent";
		break;
	case MTD_RAM:
		type = "ram";
		break;
	case MTD_ROM:
		type = "rom";
		break;
	case MTD_NORFLASH:
		type = "nor";
		break;
	case MTD_NANDFLASH:
		type = "nand";
		break;
	case MTD_DATAFLASH:
		type = "dataflash";
		break;
	case MTD_UBIVOLUME:
		type = "ubi";
		break;
	default:
		type = "unknown";
	}

	return snprintf(buf, PAGE_SIZE, "%s\n", type);
}
static DEVICE_ATTR(type, S_IRUGO, mtd_type_show, NULL);

static ssize_t mtd_flags_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "0x%lx\n", (unsigned long)mtd->flags);

}
static DEVICE_ATTR(flags, S_IRUGO, mtd_flags_show, NULL);

static ssize_t mtd_size_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)mtd->size);

}
static DEVICE_ATTR(size, S_IRUGO, mtd_size_show, NULL);

static ssize_t mtd_erasesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->erasesize);

}
static DEVICE_ATTR(erasesize, S_IRUGO, mtd_erasesize_show, NULL);

static ssize_t mtd_writesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->writesize);

}
static DEVICE_ATTR(writesize, S_IRUGO, mtd_writesize_show, NULL);

static ssize_t mtd_subpagesize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);
	unsigned int subpagesize = mtd->writesize >> mtd->subpage_sft;

	return snprintf(buf, PAGE_SIZE, "%u\n", subpagesize);

}
static DEVICE_ATTR(subpagesize, S_IRUGO, mtd_subpagesize_show, NULL);

static ssize_t mtd_oobsize_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%lu\n", (unsigned long)mtd->oobsize);

}
static DEVICE_ATTR(oobsize, S_IRUGO, mtd_oobsize_show, NULL);

static ssize_t mtd_numeraseregions_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%u\n", mtd->numeraseregions);

}
static DEVICE_ATTR(numeraseregions, S_IRUGO, mtd_numeraseregions_show,
	NULL);

static ssize_t mtd_name_show(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct mtd_info *mtd = dev_to_mtd(dev);

	return snprintf(buf, PAGE_SIZE, "%s\n", mtd->name);

}
static DEVICE_ATTR(name, S_IRUGO, mtd_name_show, NULL);

static struct attribute *mtd_attrs[] = {
	&dev_attr_type.attr,
	&dev_attr_flags.attr,
	&dev_attr_size.attr,
	&dev_attr_erasesize.attr,
	&dev_attr_writesize.attr,
	&dev_attr_subpagesize.attr,
	&dev_attr_oobsize.attr,
	&dev_attr_numeraseregions.attr,
	&dev_attr_name.attr,
	NULL,
};

static struct attribute_group mtd_group = {
	.attrs		= mtd_attrs,
};

static const struct attribute_group *mtd_groups[] = {
	&mtd_group,
	NULL,
};

static struct device_type mtd_devtype = {
	.name		= "mtd",
	.groups		= mtd_groups,
	.release	= mtd_release,
};

/**
 *	add_mtd_device - register an MTD device
 *	@mtd: pointer to new MTD device info structure
 *
 *	Add a device to the list of MTD devices present in the system, and
 *	notify each currently active MTD 'user' of its arrival. Returns
 *	zero on success or 1 on failure, which currently will only happen
 *	if there is insufficient memory or a sysfs error.
 */

int add_mtd_device(struct mtd_info *mtd)
{
	struct mtd_notifier *not;
	int i, error;

	if (!mtd->backing_dev_info) {
		switch (mtd->type) {
		case MTD_RAM:
			mtd->backing_dev_info = &mtd_bdi_rw_mappable;
			break;
		case MTD_ROM:
			mtd->backing_dev_info = &mtd_bdi_ro_mappable;
			break;
		default:
			mtd->backing_dev_info = &mtd_bdi_unmappable;
			break;
		}
	}

	BUG_ON(mtd->writesize == 0);
	mutex_lock(&mtd_table_mutex);

	do {
		if (!idr_pre_get(&mtd_idr, GFP_KERNEL))
			goto fail_locked;
		error = idr_get_new(&mtd_idr, mtd, &i);
	} while (error == -EAGAIN);

	if (error)
		goto fail_locked;

	mtd->index = i;
	mtd->usecount = 0;

	if (is_power_of_2(mtd->erasesize))
		mtd->erasesize_shift = ffs(mtd->erasesize) - 1;
	else
		mtd->erasesize_shift = 0;

	if (is_power_of_2(mtd->writesize))
		mtd->writesize_shift = ffs(mtd->writesize) - 1;
	else
		mtd->writesize_shift = 0;

	mtd->erasesize_mask = (1 << mtd->erasesize_shift) - 1;
	mtd->writesize_mask = (1 << mtd->writesize_shift) - 1;

	/* Some chips always power up locked. Unlock them now */
	if ((mtd->flags & MTD_WRITEABLE)
	    && (mtd->flags & MTD_POWERUP_LOCK) && mtd->unlock) {
		if (mtd->unlock(mtd, 0, mtd->size))
			printk(KERN_WARNING
			       "%s: unlock failed, writes may not work\n",
			       mtd->name);
	}

	/* Caller should have set dev.parent to match the
	 * physical device.
	 */
	mtd->dev.type = &mtd_devtype;
	mtd->dev.class = &mtd_class;
	mtd->dev.devt = MTD_DEVT(i);
	dev_set_name(&mtd->dev, "mtd%d", i);
	dev_set_drvdata(&mtd->dev, mtd);
	if (device_register(&mtd->dev) != 0)
		goto fail_added;

	if (MTD_DEVT(i))
		device_create(&mtd_class, mtd->dev.parent,
			      MTD_DEVT(i) + 1,
			      NULL, "mtd%dro", i);

	DEBUG(0, "mtd: Giving out device %d to %s\n", i, mtd->name);
	/* No need to get a refcount on the module containing
	   the notifier, since we hold the mtd_table_mutex */
	list_for_each_entry(not, &mtd_notifiers, list)
		not->add(mtd);

	mutex_unlock(&mtd_table_mutex);
	/* We _know_ we aren't being removed, because
	   our caller is still holding us here. So none
	   of this try_ nonsense, and no bitching about it
	   either. :) */
	__module_get(THIS_MODULE);
	return 0;

fail_added:
	idr_remove(&mtd_idr, i);
fail_locked:
	mutex_unlock(&mtd_table_mutex);
	return 1;
}

/**
 *	del_mtd_device - unregister an MTD device
 *	@mtd: pointer to MTD device info structure
 *
 *	Remove a device from the list of MTD devices present in the system,
 *	and notify each currently active MTD 'user' of its departure.
 *	Returns zero on success or 1 on failure, which currently will happen
 *	if the requested device does not appear to be present in the list.
 */

int del_mtd_device (struct mtd_info *mtd)
{
	int ret;
	struct mtd_notifier *not;

	mutex_lock(&mtd_table_mutex);

	if (idr_find(&mtd_idr, mtd->index) != mtd) {
		ret = -ENODEV;
		goto out_error;
	}

	/* No need to get a refcount on the module containing
		the notifier, since we hold the mtd_table_mutex */
	list_for_each_entry(not, &mtd_notifiers, list)
		not->remove(mtd);

	if (mtd->usecount) {
		printk(KERN_NOTICE "Removing MTD device #%d (%s) with use count %d\n",
		       mtd->index, mtd->name, mtd->usecount);
		ret = -EBUSY;
	} else {
		device_unregister(&mtd->dev);

		idr_remove(&mtd_idr, mtd->index);

		module_put(THIS_MODULE);
		ret = 0;
	}

out_error:
	mutex_unlock(&mtd_table_mutex);
	return ret;
}

/**
 *	register_mtd_user - register a 'user' of MTD devices.
 *	@new: pointer to notifier info structure
 *
 *	Registers a pair of callbacks function to be called upon addition
 *	or removal of MTD devices. Causes the 'add' callback to be immediately
 *	invoked for each MTD device currently present in the system.
 */

void register_mtd_user (struct mtd_notifier *new)
{
	struct mtd_info *mtd;

	mutex_lock(&mtd_table_mutex);

	list_add(&new->list, &mtd_notifiers);

 	__module_get(THIS_MODULE);

	mtd_for_each_device(mtd)
		new->add(mtd);

	mutex_unlock(&mtd_table_mutex);
}

/**
 *	unregister_mtd_user - unregister a 'user' of MTD devices.
 *	@old: pointer to notifier info structure
 *
 *	Removes a callback function pair from the list of 'users' to be
 *	notified upon addition or removal of MTD devices. Causes the
 *	'remove' callback to be immediately invoked for each MTD device
 *	currently present in the system.
 */

int unregister_mtd_user (struct mtd_notifier *old)
{
	struct mtd_info *mtd;

	mutex_lock(&mtd_table_mutex);

	module_put(THIS_MODULE);

	mtd_for_each_device(mtd)
		old->remove(mtd);

	list_del(&old->list);
	mutex_unlock(&mtd_table_mutex);
	return 0;
}


/**
 *	get_mtd_device - obtain a validated handle for an MTD device
 *	@mtd: last known address of the required MTD device
 *	@num: internal device number of the required MTD device
 *
 *	Given a number and NULL address, return the num'th entry in the device
 *	table, if any.	Given an address and num == -1, search the device table
 *	for a device with that address and return if it's still present. Given
 *	both, return the num'th driver only if its address matches. Return
 *	error code if not.
 */

struct mtd_info *get_mtd_device(struct mtd_info *mtd, int num)
{
	struct mtd_info *ret = NULL, *other;
	int err = -ENODEV;

	mutex_lock(&mtd_table_mutex);

	if (num == -1) {
		mtd_for_each_device(other) {
			if (other == mtd) {
				ret = mtd;
				break;
			}
		}
	} else if (num >= 0) {
		ret = idr_find(&mtd_idr, num);
		if (mtd && mtd != ret)
			ret = NULL;
	}

	if (!ret) {
		ret = ERR_PTR(err);
		goto out;
	}

	err = __get_mtd_device(ret);
	if (err)
		ret = ERR_PTR(err);
out:
	mutex_unlock(&mtd_table_mutex);
	return ret;
}


int __get_mtd_device(struct mtd_info *mtd)
{
	int err;

	if (!try_module_get(mtd->owner))
		return -ENODEV;

	if (mtd->get_device) {

		err = mtd->get_device(mtd);

		if (err) {
			module_put(mtd->owner);
			return err;
		}
	}
	mtd->usecount++;
	return 0;
}

/**
 *	get_mtd_device_nm - obtain a validated handle for an MTD device by
 *	device name
 *	@name: MTD device name to open
 *
 * 	This function returns MTD device description structure in case of
 * 	success and an error code in case of failure.
 */

struct mtd_info *get_mtd_device_nm(const char *name)
{
	int err = -ENODEV;
	struct mtd_info *mtd = NULL, *other;

	mutex_lock(&mtd_table_mutex);

	mtd_for_each_device(other) {
		if (!strcmp(name, other->name)) {
			mtd = other;
			break;
		}
	}

	if (!mtd)
		goto out_unlock;

	if (!try_module_get(mtd->owner))
		goto out_unlock;

	if (mtd->get_device) {
		err = mtd->get_device(mtd);
		if (err)
			goto out_put;
	}

	mtd->usecount++;
	mutex_unlock(&mtd_table_mutex);
	return mtd;

out_put:
	module_put(mtd->owner);
out_unlock:
	mutex_unlock(&mtd_table_mutex);
	return ERR_PTR(err);
}

void put_mtd_device(struct mtd_info *mtd)
{
	mutex_lock(&mtd_table_mutex);
	__put_mtd_device(mtd);
	mutex_unlock(&mtd_table_mutex);

}

void __put_mtd_device(struct mtd_info *mtd)
{
	--mtd->usecount;
	BUG_ON(mtd->usecount < 0);

	if (mtd->put_device)
		mtd->put_device(mtd);

	module_put(mtd->owner);
}

/* default_mtd_writev - default mtd writev method for MTD devices that
 *			don't implement their own
 */

int default_mtd_writev(struct mtd_info *mtd, const struct kvec *vecs,
		       unsigned long count, loff_t to, size_t *retlen)
{
	unsigned long i;
	size_t totlen = 0, thislen;
	int ret = 0;

	if(!mtd->write) {
		ret = -EROFS;
	} else {
		for (i=0; i<count; i++) {
			if (!vecs[i].iov_len)
				continue;
			ret = mtd->write(mtd, to, vecs[i].iov_len, &thislen, vecs[i].iov_base);
			totlen += thislen;
			if (ret || thislen != vecs[i].iov_len)
				break;
			to += vecs[i].iov_len;
		}
	}
	if (retlen)
		*retlen = totlen;
	return ret;
}

EXPORT_SYMBOL_GPL(add_mtd_device);
EXPORT_SYMBOL_GPL(del_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device);
EXPORT_SYMBOL_GPL(get_mtd_device_nm);
EXPORT_SYMBOL_GPL(__get_mtd_device);
EXPORT_SYMBOL_GPL(put_mtd_device);
EXPORT_SYMBOL_GPL(__put_mtd_device);
EXPORT_SYMBOL_GPL(register_mtd_user);
EXPORT_SYMBOL_GPL(unregister_mtd_user);
EXPORT_SYMBOL_GPL(default_mtd_writev);

#ifdef CONFIG_PROC_FS

/*====================================================================*/
/* Support for /proc/mtd */

static struct proc_dir_entry *proc_mtd;

static inline int mtd_proc_info(char *buf, struct mtd_info *this)
{
	return sprintf(buf, "mtd%d: %8.8llx %8.8x \"%s\"\n", this->index,
		       (unsigned long long)this->size,
		       this->erasesize, this->name);
}

static int mtd_read_proc (char *page, char **start, off_t off, int count,
			  int *eof, void *data_unused)
{
	struct mtd_info *mtd;
	int len, l;
        off_t   begin = 0;

	mutex_lock(&mtd_table_mutex);

	len = sprintf(page, "dev:    size   erasesize  name\n");
	mtd_for_each_device(mtd) {
		l = mtd_proc_info(page + len, mtd);
                len += l;
                if (len+begin > off+count)
                        goto done;
                if (len+begin < off) {
                        begin += len;
                        len = 0;
                }
        }

        *eof = 1;

done:
	mutex_unlock(&mtd_table_mutex);
        if (off >= len+begin)
                return 0;
        *start = page + (off-begin);
        return ((count < begin+len-off) ? count : begin+len-off);
}

#endif /* CONFIG_PROC_FS */

/*====================================================================*/
/* Init code */

static int __init mtd_bdi_init(struct backing_dev_info *bdi, const char *name)
{
	int ret;

	ret = bdi_init(bdi);
	if (!ret)
		ret = bdi_register(bdi, NULL, name);

	if (ret)
		bdi_destroy(bdi);

	return ret;
}

static int __init init_mtd(void)
{
	int ret;

	ret = class_register(&mtd_class);
	if (ret)
		goto err_reg;

	ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
	if (ret)
		goto err_bdi1;

	ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
	if (ret)
		goto err_bdi2;

	ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
	if (ret)
		goto err_bdi3;

#ifdef CONFIG_PROC_FS
	if ((proc_mtd = create_proc_entry( "mtd", 0, NULL )))
		proc_mtd->read_proc = mtd_read_proc;
#endif /* CONFIG_PROC_FS */
	return 0;

err_bdi3:
	bdi_destroy(&mtd_bdi_ro_mappable);
err_bdi2:
	bdi_destroy(&mtd_bdi_unmappable);
err_bdi1:
	class_unregister(&mtd_class);
err_reg:
	pr_err("Error registering mtd class or bdi: %d\n", ret);
	return ret;
}

static void __exit cleanup_mtd(void)
{
#ifdef CONFIG_PROC_FS
        if (proc_mtd)
		remove_proc_entry( "mtd", NULL);
#endif /* CONFIG_PROC_FS */
	class_unregister(&mtd_class);
	bdi_destroy(&mtd_bdi_unmappable);
	bdi_destroy(&mtd_bdi_ro_mappable);
	bdi_destroy(&mtd_bdi_rw_mappable);
}

module_init(init_mtd);
module_exit(cleanup_mtd);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Core MTD registration and access routines");