aboutsummaryrefslogtreecommitdiff
path: root/drivers/mtd/mtdchar.c
blob: 6749c2f963423a96f97db2311782e9cc5414cf12 (plain)
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
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
/*
 * Character-device access to raw MTD devices.
 *
 */

#include <linux/device.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/smp_lock.h>
#include <linux/backing-dev.h>
#include <linux/compat.h>

#include <linux/mtd/mtd.h>
#include <linux/mtd/compatmac.h>

#include <asm/uaccess.h>


/*
 * Data structure to hold the pointer to the mtd device as well
 * as mode information ofr various use cases.
 */
struct mtd_file_info {
	struct mtd_info *mtd;
	enum mtd_file_modes mode;
};

static loff_t mtd_lseek (struct file *file, loff_t offset, int orig)
{
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;

	switch (orig) {
	case SEEK_SET:
		break;
	case SEEK_CUR:
		offset += file->f_pos;
		break;
	case SEEK_END:
		offset += mtd->size;
		break;
	default:
		return -EINVAL;
	}

	if (offset >= 0 && offset <= mtd->size)
		return file->f_pos = offset;

	return -EINVAL;
}



static int mtd_open(struct inode *inode, struct file *file)
{
	int minor = iminor(inode);
	int devnum = minor >> 1;
	int ret = 0;
	struct mtd_info *mtd;
	struct mtd_file_info *mfi;

	DEBUG(MTD_DEBUG_LEVEL0, "MTD_open\n");

	if (devnum >= MAX_MTD_DEVICES)
		return -ENODEV;

	/* You can't open the RO devices RW */
	if ((file->f_mode & FMODE_WRITE) && (minor & 1))
		return -EACCES;

	lock_kernel();
	mtd = get_mtd_device(NULL, devnum);

	if (IS_ERR(mtd)) {
		ret = PTR_ERR(mtd);
		goto out;
	}

	if (mtd->type == MTD_ABSENT) {
		put_mtd_device(mtd);
		ret = -ENODEV;
		goto out;
	}

	if (mtd->backing_dev_info)
		file->f_mapping->backing_dev_info = mtd->backing_dev_info;

	/* You can't open it RW if it's not a writeable device */
	if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
		put_mtd_device(mtd);
		ret = -EACCES;
		goto out;
	}

	mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
	if (!mfi) {
		put_mtd_device(mtd);
		ret = -ENOMEM;
		goto out;
	}
	mfi->mtd = mtd;
	file->private_data = mfi;

out:
	unlock_kernel();
	return ret;
} /* mtd_open */

/*====================================================================*/

static int mtd_close(struct inode *inode, struct file *file)
{
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;

	DEBUG(MTD_DEBUG_LEVEL0, "MTD_close\n");

	/* Only sync if opened RW */
	if ((file->f_mode & FMODE_WRITE) && mtd->sync)
		mtd->sync(mtd);

	put_mtd_device(mtd);
	file->private_data = NULL;
	kfree(mfi);

	return 0;
} /* mtd_close */

/* FIXME: This _really_ needs to die. In 2.5, we should lock the
   userspace buffer down and use it directly with readv/writev.
*/
#define MAX_KMALLOC_SIZE 0x20000

static ssize_t mtd_read(struct file *file, char __user *buf, size_t count,loff_t *ppos)
{
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;
	size_t retlen=0;
	size_t total_retlen=0;
	int ret=0;
	int len;
	char *kbuf;

	DEBUG(MTD_DEBUG_LEVEL0,"MTD_read\n");

	if (*ppos + count > mtd->size)
		count = mtd->size - *ppos;

	if (!count)
		return 0;

	/* FIXME: Use kiovec in 2.5 to lock down the user's buffers
	   and pass them directly to the MTD functions */

	if (count > MAX_KMALLOC_SIZE)
		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
	else
		kbuf=kmalloc(count, GFP_KERNEL);

	if (!kbuf)
		return -ENOMEM;

	while (count) {

		if (count > MAX_KMALLOC_SIZE)
			len = MAX_KMALLOC_SIZE;
		else
			len = count;

		switch (mfi->mode) {
		case MTD_MODE_OTP_FACTORY:
			ret = mtd->read_fact_prot_reg(mtd, *ppos, len, &retlen, kbuf);
			break;
		case MTD_MODE_OTP_USER:
			ret = mtd->read_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
			break;
		case MTD_MODE_RAW:
		{
			struct mtd_oob_ops ops;

			ops.mode = MTD_OOB_RAW;
			ops.datbuf = kbuf;
			ops.oobbuf = NULL;
			ops.len = len;

			ret = mtd->read_oob(mtd, *ppos, &ops);
			retlen = ops.retlen;
			break;
		}
		default:
			ret = mtd->read(mtd, *ppos, len, &retlen, kbuf);
		}
		/* Nand returns -EBADMSG on ecc errors, but it returns
		 * the data. For our userspace tools it is important
		 * to dump areas with ecc errors !
		 * For kernel internal usage it also might return -EUCLEAN
		 * to signal the caller that a bitflip has occured and has
		 * been corrected by the ECC algorithm.
		 * Userspace software which accesses NAND this way
		 * must be aware of the fact that it deals with NAND
		 */
		if (!ret || (ret == -EUCLEAN) || (ret == -EBADMSG)) {
			*ppos += retlen;
			if (copy_to_user(buf, kbuf, retlen)) {
				kfree(kbuf);
				return -EFAULT;
			}
			else
				total_retlen += retlen;

			count -= retlen;
			buf += retlen;
			if (retlen == 0)
				count = 0;
		}
		else {
			kfree(kbuf);
			return ret;
		}

	}

	kfree(kbuf);
	return total_retlen;
} /* mtd_read */

static ssize_t mtd_write(struct file *file, const char __user *buf, size_t count,loff_t *ppos)
{
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;
	char *kbuf;
	size_t retlen;
	size_t total_retlen=0;
	int ret=0;
	int len;

	DEBUG(MTD_DEBUG_LEVEL0,"MTD_write\n");

	if (*ppos == mtd->size)
		return -ENOSPC;

	if (*ppos + count > mtd->size)
		count = mtd->size - *ppos;

	if (!count)
		return 0;

	if (count > MAX_KMALLOC_SIZE)
		kbuf=kmalloc(MAX_KMALLOC_SIZE, GFP_KERNEL);
	else
		kbuf=kmalloc(count, GFP_KERNEL);

	if (!kbuf)
		return -ENOMEM;

	while (count) {

		if (count > MAX_KMALLOC_SIZE)
			len = MAX_KMALLOC_SIZE;
		else
			len = count;

		if (copy_from_user(kbuf, buf, len)) {
			kfree(kbuf);
			return -EFAULT;
		}

		switch (mfi->mode) {
		case MTD_MODE_OTP_FACTORY:
			ret = -EROFS;
			break;
		case MTD_MODE_OTP_USER:
			if (!mtd->write_user_prot_reg) {
				ret = -EOPNOTSUPP;
				break;
			}
			ret = mtd->write_user_prot_reg(mtd, *ppos, len, &retlen, kbuf);
			break;

		case MTD_MODE_RAW:
		{
			struct mtd_oob_ops ops;

			ops.mode = MTD_OOB_RAW;
			ops.datbuf = kbuf;
			ops.oobbuf = NULL;
			ops.len = len;

			ret = mtd->write_oob(mtd, *ppos, &ops);
			retlen = ops.retlen;
			break;
		}

		default:
			ret = (*(mtd->write))(mtd, *ppos, len, &retlen, kbuf);
		}
		if (!ret) {
			*ppos += retlen;
			total_retlen += retlen;
			count -= retlen;
			buf += retlen;
		}
		else {
			kfree(kbuf);
			return ret;
		}
	}

	kfree(kbuf);
	return total_retlen;
} /* mtd_write */

/*======================================================================

    IOCTL calls for getting device parameters.

======================================================================*/
static void mtdchar_erase_callback (struct erase_info *instr)
{
	wake_up((wait_queue_head_t *)instr->priv);
}

#ifdef CONFIG_HAVE_MTD_OTP
static int otp_select_filemode(struct mtd_file_info *mfi, int mode)
{
	struct mtd_info *mtd = mfi->mtd;
	int ret = 0;

	switch (mode) {
	case MTD_OTP_FACTORY:
		if (!mtd->read_fact_prot_reg)
			ret = -EOPNOTSUPP;
		else
			mfi->mode = MTD_MODE_OTP_FACTORY;
		break;
	case MTD_OTP_USER:
		if (!mtd->read_fact_prot_reg)
			ret = -EOPNOTSUPP;
		else
			mfi->mode = MTD_MODE_OTP_USER;
		break;
	default:
		ret = -EINVAL;
	case MTD_OTP_OFF:
		break;
	}
	return ret;
}
#else
# define otp_select_filemode(f,m)	-EOPNOTSUPP
#endif

static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
	uint64_t start, uint32_t length, void __user *ptr,
	uint32_t __user *retp)
{
	struct mtd_oob_ops ops;
	uint32_t retlen;
	int ret = 0;

	if (!(file->f_mode & FMODE_WRITE))
		return -EPERM;

	if (length > 4096)
		return -EINVAL;

	if (!mtd->write_oob)
		ret = -EOPNOTSUPP;
	else
		ret = access_ok(VERIFY_READ, ptr, length) ? 0 : EFAULT;

	if (ret)
		return ret;

	ops.ooblen = length;
	ops.ooboffs = start & (mtd->oobsize - 1);
	ops.datbuf = NULL;
	ops.mode = MTD_OOB_PLACE;

	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
		return -EINVAL;

	ops.oobbuf = kmalloc(length, GFP_KERNEL);
	if (!ops.oobbuf)
		return -ENOMEM;

	if (copy_from_user(ops.oobbuf, ptr, length)) {
		kfree(ops.oobbuf);
		return -EFAULT;
	}

	start &= ~((uint64_t)mtd->oobsize - 1);
	ret = mtd->write_oob(mtd, start, &ops);

	if (ops.oobretlen > 0xFFFFFFFFU)
		ret = -EOVERFLOW;
	retlen = ops.oobretlen;
	if (copy_to_user(retp, &retlen, sizeof(length)))
		ret = -EFAULT;

	kfree(ops.oobbuf);
	return ret;
}

static int mtd_do_readoob(struct mtd_info *mtd, uint64_t start,
	uint32_t length, void __user *ptr, uint32_t __user *retp)
{
	struct mtd_oob_ops ops;
	int ret = 0;

	if (length > 4096)
		return -EINVAL;

	if (!mtd->read_oob)
		ret = -EOPNOTSUPP;
	else
		ret = access_ok(VERIFY_WRITE, ptr,
				length) ? 0 : -EFAULT;
	if (ret)
		return ret;

	ops.ooblen = length;
	ops.ooboffs = start & (mtd->oobsize - 1);
	ops.datbuf = NULL;
	ops.mode = MTD_OOB_PLACE;

	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
		return -EINVAL;

	ops.oobbuf = kmalloc(length, GFP_KERNEL);
	if (!ops.oobbuf)
		return -ENOMEM;

	start &= ~((uint64_t)mtd->oobsize - 1);
	ret = mtd->read_oob(mtd, start, &ops);

	if (put_user(ops.oobretlen, retp))
		ret = -EFAULT;
	else if (ops.oobretlen && copy_to_user(ptr, ops.oobbuf,
					    ops.oobretlen))
		ret = -EFAULT;

	kfree(ops.oobbuf);
	return ret;
}

static int mtd_ioctl(struct file *file, u_int cmd, u_long arg)
{
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;
	void __user *argp = (void __user *)arg;
	int ret = 0;
	u_long size;
	struct mtd_info_user info;

	DEBUG(MTD_DEBUG_LEVEL0, "MTD_ioctl\n");

	size = (cmd & IOCSIZE_MASK) >> IOCSIZE_SHIFT;
	if (cmd & IOC_IN) {
		if (!access_ok(VERIFY_READ, argp, size))
			return -EFAULT;
	}
	if (cmd & IOC_OUT) {
		if (!access_ok(VERIFY_WRITE, argp, size))
			return -EFAULT;
	}

	switch (cmd) {
	case MEMGETREGIONCOUNT:
		if (copy_to_user(argp, &(mtd->numeraseregions), sizeof(int)))
			return -EFAULT;
		break;

	case MEMGETREGIONINFO:
	{
		uint32_t ur_idx;
		struct mtd_erase_region_info *kr;
		struct region_info_user *ur = (struct region_info_user *) argp;

		if (get_user(ur_idx, &(ur->regionindex)))
			return -EFAULT;

		kr = &(mtd->eraseregions[ur_idx]);

		if (put_user(kr->offset, &(ur->offset))
		    || put_user(kr->erasesize, &(ur->erasesize))
		    || put_user(kr->numblocks, &(ur->numblocks)))
			return -EFAULT;

		break;
	}

	case MEMGETINFO:
		info.type	= mtd->type;
		info.flags	= mtd->flags;
		info.size	= mtd->size;
		info.erasesize	= mtd->erasesize;
		info.writesize	= mtd->writesize;
		info.oobsize	= mtd->oobsize;
		/* The below fields are obsolete */
		info.ecctype	= -1;
		info.eccsize	= 0;
		if (copy_to_user(argp, &info, sizeof(struct mtd_info_user)))
			return -EFAULT;
		break;

	case MEMERASE:
	case MEMERASE64:
	{
		struct erase_info *erase;

		if(!(file->f_mode & FMODE_WRITE))
			return -EPERM;

		erase=kzalloc(sizeof(struct erase_info),GFP_KERNEL);
		if (!erase)
			ret = -ENOMEM;
		else {
			wait_queue_head_t waitq;
			DECLARE_WAITQUEUE(wait, current);

			init_waitqueue_head(&waitq);

			if (cmd == MEMERASE64) {
				struct erase_info_user64 einfo64;

				if (copy_from_user(&einfo64, argp,
					    sizeof(struct erase_info_user64))) {
					kfree(erase);
					return -EFAULT;
				}
				erase->addr = einfo64.start;
				erase->len = einfo64.length;
			} else {
				struct erase_info_user einfo32;

				if (copy_from_user(&einfo32, argp,
					    sizeof(struct erase_info_user))) {
					kfree(erase);
					return -EFAULT;
				}
				erase->addr = einfo32.start;
				erase->len = einfo32.length;
			}
			erase->mtd = mtd;
			erase->callback = mtdchar_erase_callback;
			erase->priv = (unsigned long)&waitq;

			/*
			  FIXME: Allow INTERRUPTIBLE. Which means
			  not having the wait_queue head on the stack.

			  If the wq_head is on the stack, and we
			  leave because we got interrupted, then the
			  wq_head is no longer there when the
			  callback routine tries to wake us up.
			*/
			ret = mtd->erase(mtd, erase);
			if (!ret) {
				set_current_state(TASK_UNINTERRUPTIBLE);
				add_wait_queue(&waitq, &wait);
				if (erase->state != MTD_ERASE_DONE &&
				    erase->state != MTD_ERASE_FAILED)
					schedule();
				remove_wait_queue(&waitq, &wait);
				set_current_state(TASK_RUNNING);

				ret = (erase->state == MTD_ERASE_FAILED)?-EIO:0;
			}
			kfree(erase);
		}
		break;
	}

	case MEMWRITEOOB:
	{
		struct mtd_oob_buf buf;
		struct mtd_oob_buf __user *buf_user = argp;

		/* NOTE: writes return length to buf_user->length */
		if (copy_from_user(&buf, argp, sizeof(buf)))
			ret = -EFAULT;
		else
			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
				buf.ptr, &buf_user->length);
		break;
	}

	case MEMREADOOB:
	{
		struct mtd_oob_buf buf;
		struct mtd_oob_buf __user *buf_user = argp;

		/* NOTE: writes return length to buf_user->start */
		if (copy_from_user(&buf, argp, sizeof(buf)))
			ret = -EFAULT;
		else
			ret = mtd_do_readoob(mtd, buf.start, buf.length,
				buf.ptr, &buf_user->start);
		break;
	}

	case MEMWRITEOOB64:
	{
		struct mtd_oob_buf64 buf;
		struct mtd_oob_buf64 __user *buf_user = argp;

		if (copy_from_user(&buf, argp, sizeof(buf)))
			ret = -EFAULT;
		else
			ret = mtd_do_writeoob(file, mtd, buf.start, buf.length,
				(void __user *)(uintptr_t)buf.usr_ptr,
				&buf_user->length);
		break;
	}

	case MEMREADOOB64:
	{
		struct mtd_oob_buf64 buf;
		struct mtd_oob_buf64 __user *buf_user = argp;

		if (copy_from_user(&buf, argp, sizeof(buf)))
			ret = -EFAULT;
		else
			ret = mtd_do_readoob(mtd, buf.start, buf.length,
				(void __user *)(uintptr_t)buf.usr_ptr,
				&buf_user->length);
		break;
	}

	case MEMLOCK:
	{
		struct erase_info_user einfo;

		if (copy_from_user(&einfo, argp, sizeof(einfo)))
			return -EFAULT;

		if (!mtd->lock)
			ret = -EOPNOTSUPP;
		else
			ret = mtd->lock(mtd, einfo.start, einfo.length);
		break;
	}

	case MEMUNLOCK:
	{
		struct erase_info_user einfo;

		if (copy_from_user(&einfo, argp, sizeof(einfo)))
			return -EFAULT;

		if (!mtd->unlock)
			ret = -EOPNOTSUPP;
		else
			ret = mtd->unlock(mtd, einfo.start, einfo.length);
		break;
	}

	/* Legacy interface */
	case MEMGETOOBSEL:
	{
		struct nand_oobinfo oi;

		if (!mtd->ecclayout)
			return -EOPNOTSUPP;
		if (mtd->ecclayout->eccbytes > ARRAY_SIZE(oi.eccpos))
			return -EINVAL;

		oi.useecc = MTD_NANDECC_AUTOPLACE;
		memcpy(&oi.eccpos, mtd->ecclayout->eccpos, sizeof(oi.eccpos));
		memcpy(&oi.oobfree, mtd->ecclayout->oobfree,
		       sizeof(oi.oobfree));
		oi.eccbytes = mtd->ecclayout->eccbytes;

		if (copy_to_user(argp, &oi, sizeof(struct nand_oobinfo)))
			return -EFAULT;
		break;
	}

	case MEMGETBADBLOCK:
	{
		loff_t offs;

		if (copy_from_user(&offs, argp, sizeof(loff_t)))
			return -EFAULT;
		if (!mtd->block_isbad)
			ret = -EOPNOTSUPP;
		else
			return mtd->block_isbad(mtd, offs);
		break;
	}

	case MEMSETBADBLOCK:
	{
		loff_t offs;

		if (copy_from_user(&offs, argp, sizeof(loff_t)))
			return -EFAULT;
		if (!mtd->block_markbad)
			ret = -EOPNOTSUPP;
		else
			return mtd->block_markbad(mtd, offs);
		break;
	}

#ifdef CONFIG_HAVE_MTD_OTP
	case OTPSELECT:
	{
		int mode;
		if (copy_from_user(&mode, argp, sizeof(int)))
			return -EFAULT;

		mfi->mode = MTD_MODE_NORMAL;

		ret = otp_select_filemode(mfi, mode);

		file->f_pos = 0;
		break;
	}

	case OTPGETREGIONCOUNT:
	case OTPGETREGIONINFO:
	{
		struct otp_info *buf = kmalloc(4096, GFP_KERNEL);
		if (!buf)
			return -ENOMEM;
		ret = -EOPNOTSUPP;
		switch (mfi->mode) {
		case MTD_MODE_OTP_FACTORY:
			if (mtd->get_fact_prot_info)
				ret = mtd->get_fact_prot_info(mtd, buf, 4096);
			break;
		case MTD_MODE_OTP_USER:
			if (mtd->get_user_prot_info)
				ret = mtd->get_user_prot_info(mtd, buf, 4096);
			break;
		default:
			break;
		}
		if (ret >= 0) {
			if (cmd == OTPGETREGIONCOUNT) {
				int nbr = ret / sizeof(struct otp_info);
				ret = copy_to_user(argp, &nbr, sizeof(int));
			} else
				ret = copy_to_user(argp, buf, ret);
			if (ret)
				ret = -EFAULT;
		}
		kfree(buf);
		break;
	}

	case OTPLOCK:
	{
		struct otp_info oinfo;

		if (mfi->mode != MTD_MODE_OTP_USER)
			return -EINVAL;
		if (copy_from_user(&oinfo, argp, sizeof(oinfo)))
			return -EFAULT;
		if (!mtd->lock_user_prot_reg)
			return -EOPNOTSUPP;
		ret = mtd->lock_user_prot_reg(mtd, oinfo.start, oinfo.length);
		break;
	}
#endif

	case ECCGETLAYOUT:
	{
		if (!mtd->ecclayout)
			return -EOPNOTSUPP;

		if (copy_to_user(argp, mtd->ecclayout,
				 sizeof(struct nand_ecclayout)))
			return -EFAULT;
		break;
	}

	case ECCGETSTATS:
	{
		if (copy_to_user(argp, &mtd->ecc_stats,
				 sizeof(struct mtd_ecc_stats)))
			return -EFAULT;
		break;
	}

	case MTDFILEMODE:
	{
		mfi->mode = 0;

		switch(arg) {
		case MTD_MODE_OTP_FACTORY:
		case MTD_MODE_OTP_USER:
			ret = otp_select_filemode(mfi, arg);
			break;

		case MTD_MODE_RAW:
			if (!mtd->read_oob || !mtd->write_oob)
				return -EOPNOTSUPP;
			mfi->mode = arg;

		case MTD_MODE_NORMAL:
			break;
		default:
			ret = -EINVAL;
		}
		file->f_pos = 0;
		break;
	}

	default:
		ret = -ENOTTY;
	}

	return ret;
} /* memory_ioctl */

static long mtd_unlocked_ioctl(struct file *file, u_int cmd, u_long arg)
{
	int ret;

	lock_kernel();
	ret = mtd_ioctl(file, cmd, arg);
	unlock_kernel();

	return ret;
}

#ifdef CONFIG_COMPAT

struct mtd_oob_buf32 {
	u_int32_t start;
	u_int32_t length;
	compat_caddr_t ptr;	/* unsigned char* */
};

#define MEMWRITEOOB32		_IOWR('M', 3, struct mtd_oob_buf32)
#define MEMREADOOB32		_IOWR('M', 4, struct mtd_oob_buf32)

static long mtd_compat_ioctl(struct file *file, unsigned int cmd,
	unsigned long arg)
{
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;
	void __user *argp = compat_ptr(arg);
	int ret = 0;

	lock_kernel();

	switch (cmd) {
	case MEMWRITEOOB32:
	{
		struct mtd_oob_buf32 buf;
		struct mtd_oob_buf32 __user *buf_user = argp;

		if (copy_from_user(&buf, argp, sizeof(buf)))
			ret = -EFAULT;
		else
			ret = mtd_do_writeoob(file, mtd, buf.start,
				buf.length, compat_ptr(buf.ptr),
				&buf_user->length);
		break;
	}

	case MEMREADOOB32:
	{
		struct mtd_oob_buf32 buf;
		struct mtd_oob_buf32 __user *buf_user = argp;

		/* NOTE: writes return length to buf->start */
		if (copy_from_user(&buf, argp, sizeof(buf)))
			ret = -EFAULT;
		else
			ret = mtd_do_readoob(mtd, buf.start,
				buf.length, compat_ptr(buf.ptr),
				&buf_user->start);
		break;
	}
	default:
		ret = mtd_ioctl(file, cmd, (unsigned long)argp);
	}

	unlock_kernel();

	return ret;
}

#endif /* CONFIG_COMPAT */

/*
 * try to determine where a shared mapping can be made
 * - only supported for NOMMU at the moment (MMU can't doesn't copy private
 *   mappings)
 */
#ifndef CONFIG_MMU
static unsigned long mtd_get_unmapped_area(struct file *file,
					   unsigned long addr,
					   unsigned long len,
					   unsigned long pgoff,
					   unsigned long flags)
{
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;

	if (mtd->get_unmapped_area) {
		unsigned long offset;

		if (addr != 0)
			return (unsigned long) -EINVAL;

		if (len > mtd->size || pgoff >= (mtd->size >> PAGE_SHIFT))
			return (unsigned long) -EINVAL;

		offset = pgoff << PAGE_SHIFT;
		if (offset > mtd->size - len)
			return (unsigned long) -EINVAL;

		return mtd->get_unmapped_area(mtd, len, offset, flags);
	}

	/* can't map directly */
	return (unsigned long) -ENOSYS;
}
#endif

/*
 * set up a mapping for shared memory segments
 */
static int mtd_mmap(struct file *file, struct vm_area_struct *vma)
{
#ifdef CONFIG_MMU
	struct mtd_file_info *mfi = file->private_data;
	struct mtd_info *mtd = mfi->mtd;

	if (mtd->type == MTD_RAM || mtd->type == MTD_ROM)
		return 0;
	return -ENOSYS;
#else
	return vma->vm_flags & VM_SHARED ? 0 : -ENOSYS;
#endif
}

static const struct file_operations mtd_fops = {
	.owner		= THIS_MODULE,
	.llseek		= mtd_lseek,
	.read		= mtd_read,
	.write		= mtd_write,
	.unlocked_ioctl	= mtd_unlocked_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl	= mtd_compat_ioctl,
#endif
	.open		= mtd_open,
	.release	= mtd_close,
	.mmap		= mtd_mmap,
#ifndef CONFIG_MMU
	.get_unmapped_area = mtd_get_unmapped_area,
#endif
};

static int __init init_mtdchar(void)
{
	int status;

	status = register_chrdev(MTD_CHAR_MAJOR, "mtd", &mtd_fops);
	if (status < 0) {
		printk(KERN_NOTICE "Can't allocate major number %d for Memory Technology Devices.\n",
		       MTD_CHAR_MAJOR);
	}

	return status;
}

static void __exit cleanup_mtdchar(void)
{
	unregister_chrdev(MTD_CHAR_MAJOR, "mtd");
}

module_init(init_mtdchar);
module_exit(cleanup_mtdchar);

MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("David Woodhouse <dwmw2@infradead.org>");
MODULE_DESCRIPTION("Direct character-device access to MTD devices");
MODULE_ALIAS_CHARDEV_MAJOR(MTD_CHAR_MAJOR);