summaryrefslogtreecommitdiff
path: root/drivers/nand/nand_util.c
blob: 135e3c43ae8b6371ba726cfd33221e7f19000244 (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
/*
 * drivers/nand/nand_util.c
 *
 * Copyright (C) 2006 by Weiss-Electronic GmbH.
 * All rights reserved.
 *
 * @author:	Guido Classen <clagix@gmail.com>
 * @descr:	NAND Flash support
 * @references: borrowed heavily from Linux mtd-utils code:
 *		flash_eraseall.c by Arcom Control System Ltd
 *		nandwrite.c by Steven J. Hill (sjhill@realitydiluted.com)
 *			       and Thomas Gleixner (tglx@linutronix.de)
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 *
 */

#include <common.h>

#if ((CONFIG_COMMANDS & CFG_CMD_NAND) || defined(CONFIG_CMD_NAND)) && !defined(CFG_NAND_LEGACY)

#include <command.h>
#include <watchdog.h>
#include <malloc.h>

#include <nand.h>
#include <jffs2/jffs2.h>

typedef struct erase_info erase_info_t;
typedef struct mtd_info	  mtd_info_t;

/* support only for native endian JFFS2 */
#define cpu_to_je16(x) (x)
#define cpu_to_je32(x) (x)

/*****************************************************************************/
static int nand_block_bad_scrub(struct mtd_info *mtd, loff_t ofs, int getchip)
{
	return 0;
}

/**
 * nand_erase_opts: - erase NAND flash with support for various options
 *		      (jffs2 formating)
 *
 * @param meminfo	NAND device to erase
 * @param opts		options,  @see struct nand_erase_options
 * @return		0 in case of success
 *
 * This code is ported from flash_eraseall.c from Linux mtd utils by
 * Arcom Control System Ltd.
 */
int nand_erase_opts(nand_info_t *meminfo, const nand_erase_options_t *opts)
{
	struct jffs2_unknown_node cleanmarker;
	int clmpos = 0;
	int clmlen = 8;
	erase_info_t erase;
	ulong erase_length;
	int isNAND;
	int bbtest = 1;
	int result;
	int percent_complete = -1;
	int (*nand_block_bad_old)(struct mtd_info *, loff_t, int) = NULL;
	const char *mtd_device = meminfo->name;

	memset(&erase, 0, sizeof(erase));

	erase.mtd = meminfo;
	erase.len  = meminfo->erasesize;
	erase.addr = opts->offset;
	erase_length = opts->length;

	isNAND = meminfo->type == MTD_NANDFLASH ? 1 : 0;

	if (opts->jffs2) {
		cleanmarker.magic = cpu_to_je16 (JFFS2_MAGIC_BITMASK);
		cleanmarker.nodetype = cpu_to_je16 (JFFS2_NODETYPE_CLEANMARKER);
		if (isNAND) {
			struct nand_oobinfo *oobinfo = &meminfo->oobinfo;

			/* check for autoplacement */
			if (oobinfo->useecc == MTD_NANDECC_AUTOPLACE) {
				/* get the position of the free bytes */
				if (!oobinfo->oobfree[0][1]) {
					printf(" Eeep. Autoplacement selected "
					       "and no empty space in oob\n");
					return -1;
				}
				clmpos = oobinfo->oobfree[0][0];
				clmlen = oobinfo->oobfree[0][1];
				if (clmlen > 8)
					clmlen = 8;
			} else {
				/* legacy mode */
				switch (meminfo->oobsize) {
				case 8:
					clmpos = 6;
					clmlen = 2;
					break;
				case 16:
					clmpos = 8;
					clmlen = 8;
					break;
				case 64:
					clmpos = 16;
					clmlen = 8;
					break;
				}
			}

			cleanmarker.totlen = cpu_to_je32(8);
		} else {
			cleanmarker.totlen =
				cpu_to_je32(sizeof(struct jffs2_unknown_node));
		}
		cleanmarker.hdr_crc =  cpu_to_je32(
			crc32_no_comp(0, (unsigned char *) &cleanmarker,
				      sizeof(struct jffs2_unknown_node) - 4));
	}

	/* scrub option allows to erase badblock. To prevent internal
	 * check from erase() method, set block check method to dummy
	 * and disable bad block table while erasing.
	 */
	if (opts->scrub) {
		struct nand_chip *priv_nand = meminfo->priv;

		nand_block_bad_old = priv_nand->block_bad;
		priv_nand->block_bad = nand_block_bad_scrub;
		/* we don't need the bad block table anymore...
		 * after scrub, there are no bad blocks left!
		 */
		if (priv_nand->bbt) {
			kfree(priv_nand->bbt);
		}
		priv_nand->bbt = NULL;
	}

	for (;
	     erase.addr < opts->offset + erase_length;
	     erase.addr += meminfo->erasesize) {

		WATCHDOG_RESET ();

		if (!opts->scrub && bbtest) {
			int ret = meminfo->block_isbad(meminfo, erase.addr);
			if (ret > 0) {
				if (!opts->quiet)
					printf("\rSkipping bad block at  "
					       "0x%08x                   "
					       "                         \n",
					       erase.addr);
				continue;

			} else if (ret < 0) {
				printf("\n%s: MTD get bad block failed: %d\n",
				       mtd_device,
				       ret);
				return -1;
			}
		}

		result = meminfo->erase(meminfo, &erase);
		if (result != 0) {
			printf("\n%s: MTD Erase failure: %d\n",
			       mtd_device, result);
			continue;
		}

		/* format for JFFS2 ? */
		if (opts->jffs2) {

			/* write cleanmarker */
			if (isNAND) {
				size_t written;
				result = meminfo->write_oob(meminfo,
							    erase.addr + clmpos,
							    clmlen,
							    &written,
							    (unsigned char *)
							    &cleanmarker);
				if (result != 0) {
					printf("\n%s: MTD writeoob failure: %d\n",
					       mtd_device, result);
					continue;
				}
			} else {
				printf("\n%s: this erase routine only supports"
				       " NAND devices!\n",
				       mtd_device);
			}
		}

		if (!opts->quiet) {
			int percent = (int)
				((unsigned long long)
				 (erase.addr+meminfo->erasesize-opts->offset)
				 * 100 / erase_length);

			/* output progress message only at whole percent
			 * steps to reduce the number of messages printed
			 * on (slow) serial consoles
			 */
			if (percent != percent_complete) {
				percent_complete = percent;

				printf("\rErasing at 0x%x -- %3d%% complete.",
				       erase.addr, percent);

				if (opts->jffs2 && result == 0)
					printf(" Cleanmarker written at 0x%x.",
					       erase.addr);
			}
		}
	}
	if (!opts->quiet)
		printf("\n");

	if (nand_block_bad_old) {
		struct nand_chip *priv_nand = meminfo->priv;

		priv_nand->block_bad = nand_block_bad_old;
		priv_nand->scan_bbt(meminfo);
	}

	return 0;
}

#define MAX_PAGE_SIZE	2048
#define MAX_OOB_SIZE	64

/*
 * buffer array used for writing data
 */
static unsigned char data_buf[MAX_PAGE_SIZE];
static unsigned char oob_buf[MAX_OOB_SIZE];

/* OOB layouts to pass into the kernel as default */
static struct nand_oobinfo none_oobinfo = {
	.useecc = MTD_NANDECC_OFF,
};

static struct nand_oobinfo jffs2_oobinfo = {
	.useecc = MTD_NANDECC_PLACE,
	.eccbytes = 6,
	.eccpos = { 0, 1, 2, 3, 6, 7 }
};

static struct nand_oobinfo yaffs_oobinfo = {
	.useecc = MTD_NANDECC_PLACE,
	.eccbytes = 6,
	.eccpos = { 8, 9, 10, 13, 14, 15}
};

static struct nand_oobinfo autoplace_oobinfo = {
	.useecc = MTD_NANDECC_AUTOPLACE
};

/**
 * nand_write_opts: - write image to NAND flash with support for various options
 *
 * @param meminfo	NAND device to erase
 * @param opts		write options (@see nand_write_options)
 * @return		0 in case of success
 *
 * This code is ported from nandwrite.c from Linux mtd utils by
 * Steven J. Hill and Thomas Gleixner.
 */
int nand_write_opts(nand_info_t *meminfo, const nand_write_options_t *opts)
{
	int imglen = 0;
	int pagelen;
	int baderaseblock;
	int blockstart = -1;
	loff_t offs;
	int readlen;
	int oobinfochanged = 0;
	int percent_complete = -1;
	struct nand_oobinfo old_oobinfo;
	ulong mtdoffset = opts->offset;
	ulong erasesize_blockalign;
	u_char *buffer = opts->buffer;
	size_t written;
	int result;

	if (opts->pad && opts->writeoob) {
		printf("Can't pad when oob data is present.\n");
		return -1;
	}

	/* set erasesize to specified number of blocks - to match
	 * jffs2 (virtual) block size */
	if (opts->blockalign == 0) {
		erasesize_blockalign = meminfo->erasesize;
	} else {
		erasesize_blockalign = meminfo->erasesize * opts->blockalign;
	}

	/* make sure device page sizes are valid */
	if (!(meminfo->oobsize == 16 && meminfo->oobblock == 512)
	    && !(meminfo->oobsize == 8 && meminfo->oobblock == 256)
	    && !(meminfo->oobsize == 64 && meminfo->oobblock == 2048)) {
		printf("Unknown flash (not normal NAND)\n");
		return -1;
	}

	/* read the current oob info */
	memcpy(&old_oobinfo, &meminfo->oobinfo, sizeof(old_oobinfo));

	/* write without ecc? */
	if (opts->noecc) {
		memcpy(&meminfo->oobinfo, &none_oobinfo,
		       sizeof(meminfo->oobinfo));
		oobinfochanged = 1;
	}

	/* autoplace ECC? */
	if (opts->autoplace && (old_oobinfo.useecc != MTD_NANDECC_AUTOPLACE)) {

		memcpy(&meminfo->oobinfo, &autoplace_oobinfo,
		       sizeof(meminfo->oobinfo));
		oobinfochanged = 1;
	}

	/* force OOB layout for jffs2 or yaffs? */
	if (opts->forcejffs2 || opts->forceyaffs) {
		struct nand_oobinfo *oobsel =
			opts->forcejffs2 ? &jffs2_oobinfo : &yaffs_oobinfo;

		if (meminfo->oobsize == 8) {
			if (opts->forceyaffs) {
				printf("YAFSS cannot operate on "
				       "256 Byte page size\n");
				goto restoreoob;
			}
			/* Adjust number of ecc bytes */
			jffs2_oobinfo.eccbytes = 3;
		}

		memcpy(&meminfo->oobinfo, oobsel, sizeof(meminfo->oobinfo));
	}

	/* get image length */
	imglen = opts->length;
	pagelen = meminfo->oobblock
		+ ((opts->writeoob != 0) ? meminfo->oobsize : 0);

	/* check, if file is pagealigned */
	if ((!opts->pad) && ((imglen % pagelen) != 0)) {
		printf("Input block length is not page aligned\n");
		goto restoreoob;
	}

	/* check, if length fits into device */
	if (((imglen / pagelen) * meminfo->oobblock)
	     > (meminfo->size - opts->offset)) {
		printf("Image %d bytes, NAND page %d bytes, "
		       "OOB area %u bytes, device size %u bytes\n",
		       imglen, pagelen, meminfo->oobblock, meminfo->size);
		printf("Input block does not fit into device\n");
		goto restoreoob;
	}

	if (!opts->quiet)
		printf("\n");

	/* get data from input and write to the device */
	while (imglen && (mtdoffset < meminfo->size)) {

		WATCHDOG_RESET ();

		/*
		 * new eraseblock, check for bad block(s). Stay in the
		 * loop to be sure if the offset changes because of
		 * a bad block, that the next block that will be
		 * written to is also checked. Thus avoiding errors if
		 * the block(s) after the skipped block(s) is also bad
		 * (number of blocks depending on the blockalign
		 */
		while (blockstart != (mtdoffset & (~erasesize_blockalign+1))) {
			blockstart = mtdoffset & (~erasesize_blockalign+1);
			offs = blockstart;
			baderaseblock = 0;

			/* check all the blocks in an erase block for
			 * bad blocks */
			do {
				int ret = meminfo->block_isbad(meminfo, offs);

				if (ret < 0) {
					printf("Bad block check failed\n");
					goto restoreoob;
				}
				if (ret == 1) {
					baderaseblock = 1;
					if (!opts->quiet)
						printf("\rBad block at 0x%lx "
						       "in erase block from "
						       "0x%x will be skipped\n",
						       (long) offs,
						       blockstart);
				}

				if (baderaseblock) {
					mtdoffset = blockstart
						+ erasesize_blockalign;
				}
				offs +=	 erasesize_blockalign
					/ opts->blockalign;
			} while (offs < blockstart + erasesize_blockalign);
		}

		readlen = meminfo->oobblock;
		if (opts->pad && (imglen < readlen)) {
			readlen = imglen;
			memset(data_buf + readlen, 0xff,
			       meminfo->oobblock - readlen);
		}

		/* read page data from input memory buffer */
		memcpy(data_buf, buffer, readlen);
		buffer += readlen;

		if (opts->writeoob) {
			/* read OOB data from input memory block, exit
			 * on failure */
			memcpy(oob_buf, buffer, meminfo->oobsize);
			buffer += meminfo->oobsize;

			/* write OOB data first, as ecc will be placed
			 * in there*/
			result = meminfo->write_oob(meminfo,
						    mtdoffset,
						    meminfo->oobsize,
						    &written,
						    (unsigned char *)
						    &oob_buf);

			if (result != 0) {
				printf("\nMTD writeoob failure: %d\n",
				       result);
				goto restoreoob;
			}
			imglen -= meminfo->oobsize;
		}

		/* write out the page data */
		result = meminfo->write(meminfo,
					mtdoffset,
					meminfo->oobblock,
					&written,
					(unsigned char *) &data_buf);

		if (result != 0) {
			printf("writing NAND page at offset 0x%lx failed\n",
			       mtdoffset);
			goto restoreoob;
		}
		imglen -= readlen;

		if (!opts->quiet) {
			int percent = (int)
				((unsigned long long)
				 (opts->length-imglen) * 100
				 / opts->length);
			/* output progress message only at whole percent
			 * steps to reduce the number of messages printed
			 * on (slow) serial consoles
			 */
			if (percent != percent_complete) {
				printf("\rWriting data at 0x%x "
				       "-- %3d%% complete.",
				       mtdoffset, percent);
				percent_complete = percent;
			}
		}

		mtdoffset += meminfo->oobblock;
	}

	if (!opts->quiet)
		printf("\n");

restoreoob:
	if (oobinfochanged) {
		memcpy(&meminfo->oobinfo, &old_oobinfo,
		       sizeof(meminfo->oobinfo));
	}

	if (imglen > 0) {
		printf("Data did not fit into device, due to bad blocks\n");
		return -1;
	}

	/* return happy */
	return 0;
}

/**
 * nand_read_opts: - read image from NAND flash with support for various options
 *
 * @param meminfo	NAND device to erase
 * @param opts		read options (@see struct nand_read_options)
 * @return		0 in case of success
 *
 */
int nand_read_opts(nand_info_t *meminfo, const nand_read_options_t *opts)
{
	int imglen = opts->length;
	int pagelen;
	int baderaseblock;
	int blockstart = -1;
	int percent_complete = -1;
	loff_t offs;
	size_t readlen;
	ulong mtdoffset = opts->offset;
	u_char *buffer = opts->buffer;
	int result;

	/* make sure device page sizes are valid */
	if (!(meminfo->oobsize == 16 && meminfo->oobblock == 512)
	    && !(meminfo->oobsize == 8 && meminfo->oobblock == 256)
	    && !(meminfo->oobsize == 64 && meminfo->oobblock == 2048)) {
		printf("Unknown flash (not normal NAND)\n");
		return -1;
	}

	pagelen = meminfo->oobblock
		+ ((opts->readoob != 0) ? meminfo->oobsize : 0);

	/* check, if length is not larger than device */
	if (((imglen / pagelen) * meminfo->oobblock)
	     > (meminfo->size - opts->offset)) {
		printf("Image %d bytes, NAND page %d bytes, "
		       "OOB area %u bytes, device size %u bytes\n",
		       imglen, pagelen, meminfo->oobblock, meminfo->size);
		printf("Input block is larger than device\n");
		return -1;
	}

	if (!opts->quiet)
		printf("\n");

	/* get data from input and write to the device */
	while (imglen && (mtdoffset < meminfo->size)) {

		WATCHDOG_RESET ();

		/*
		 * new eraseblock, check for bad block(s). Stay in the
		 * loop to be sure if the offset changes because of
		 * a bad block, that the next block that will be
		 * written to is also checked. Thus avoiding errors if
		 * the block(s) after the skipped block(s) is also bad
		 * (number of blocks depending on the blockalign
		 */
		while (blockstart != (mtdoffset & (~meminfo->erasesize+1))) {
			blockstart = mtdoffset & (~meminfo->erasesize+1);
			offs = blockstart;
			baderaseblock = 0;

			/* check all the blocks in an erase block for
			 * bad blocks */
			do {
				int ret = meminfo->block_isbad(meminfo, offs);

				if (ret < 0) {
					printf("Bad block check failed\n");
					return -1;
				}
				if (ret == 1) {
					baderaseblock = 1;
					if (!opts->quiet)
						printf("\rBad block at 0x%lx "
						       "in erase block from "
						       "0x%x will be skipped\n",
						       (long) offs,
						       blockstart);
				}

				if (baderaseblock) {
					mtdoffset = blockstart
						+ meminfo->erasesize;
				}
				offs +=	 meminfo->erasesize;

			} while (offs < blockstart + meminfo->erasesize);
		}


		/* read page data to memory buffer */
		result = meminfo->read(meminfo,
				       mtdoffset,
				       meminfo->oobblock,
				       &readlen,
				       (unsigned char *) &data_buf);

		if (result != 0) {
			printf("reading NAND page at offset 0x%lx failed\n",
			       mtdoffset);
			return -1;
		}

		if (imglen < readlen) {
			readlen = imglen;
		}

		memcpy(buffer, data_buf, readlen);
		buffer += readlen;
		imglen -= readlen;

		if (opts->readoob) {
			result = meminfo->read_oob(meminfo,
						   mtdoffset,
						   meminfo->oobsize,
						   &readlen,
						   (unsigned char *)
						   &oob_buf);

			if (result != 0) {
				printf("\nMTD readoob failure: %d\n",
				       result);
				return -1;
			}


			if (imglen < readlen) {
				readlen = imglen;
			}

			memcpy(buffer, oob_buf, readlen);

			buffer += readlen;
			imglen -= readlen;
		}

		if (!opts->quiet) {
			int percent = (int)
				((unsigned long long)
				 (opts->length-imglen) * 100
				 / opts->length);
			/* output progress message only at whole percent
			 * steps to reduce the number of messages printed
			 * on (slow) serial consoles
			 */
			if (percent != percent_complete) {
			if (!opts->quiet)
				printf("\rReading data from 0x%x "
				       "-- %3d%% complete.",
				       mtdoffset, percent);
				percent_complete = percent;
			}
		}

		mtdoffset += meminfo->oobblock;
	}

	if (!opts->quiet)
		printf("\n");

	if (imglen > 0) {
		printf("Could not read entire image due to bad blocks\n");
		return -1;
	}

	/* return happy */
	return 0;
}

/******************************************************************************
 * Support for locking / unlocking operations of some NAND devices
 *****************************************************************************/

#define NAND_CMD_LOCK		0x2a
#define NAND_CMD_LOCK_TIGHT	0x2c
#define NAND_CMD_UNLOCK1	0x23
#define NAND_CMD_UNLOCK2	0x24
#define NAND_CMD_LOCK_STATUS	0x7a

/**
 * nand_lock: Set all pages of NAND flash chip to the LOCK or LOCK-TIGHT
 *	      state
 *
 * @param meminfo	nand mtd instance
 * @param tight		bring device in lock tight mode
 *
 * @return		0 on success, -1 in case of error
 *
 * The lock / lock-tight command only applies to the whole chip. To get some
 * parts of the chip lock and others unlocked use the following sequence:
 *
 * - Lock all pages of the chip using nand_lock(mtd, 0) (or the lockpre pin)
 * - Call nand_unlock() once for each consecutive area to be unlocked
 * - If desired: Bring the chip to the lock-tight state using nand_lock(mtd, 1)
 *
 *   If the device is in lock-tight state software can't change the
 *   current active lock/unlock state of all pages. nand_lock() / nand_unlock()
 *   calls will fail. It is only posible to leave lock-tight state by
 *   an hardware signal (low pulse on _WP pin) or by power down.
 */
int nand_lock(nand_info_t *meminfo, int tight)
{
	int ret = 0;
	int status;
	struct nand_chip *this = meminfo->priv;

	/* select the NAND device */
	this->select_chip(meminfo, 0);

	this->cmdfunc(meminfo,
		      (tight ? NAND_CMD_LOCK_TIGHT : NAND_CMD_LOCK),
		      -1, -1);

	/* call wait ready function */
	status = this->waitfunc(meminfo, this, FL_WRITING);

	/* see if device thinks it succeeded */
	if (status & 0x01) {
		ret = -1;
	}

	/* de-select the NAND device */
	this->select_chip(meminfo, -1);
	return ret;
}

/**
 * nand_get_lock_status: - query current lock state from one page of NAND
 *			   flash
 *
 * @param meminfo	nand mtd instance
 * @param offset	page address to query (muss be page aligned!)
 *
 * @return		-1 in case of error
 *			>0 lock status:
 *			  bitfield with the following combinations:
 *			  NAND_LOCK_STATUS_TIGHT: page in tight state
 *			  NAND_LOCK_STATUS_LOCK:  page locked
 *			  NAND_LOCK_STATUS_UNLOCK: page unlocked
 *
 */
int nand_get_lock_status(nand_info_t *meminfo, ulong offset)
{
	int ret = 0;
	int chipnr;
	int page;
	struct nand_chip *this = meminfo->priv;

	/* select the NAND device */
	chipnr = (int)(offset >> this->chip_shift);
	this->select_chip(meminfo, chipnr);


	if ((offset & (meminfo->oobblock - 1)) != 0) {
		printf ("nand_get_lock_status: "
			"Start address must be beginning of "
			"nand page!\n");
		ret = -1;
		goto out;
	}

	/* check the Lock Status */
	page = (int)(offset >> this->page_shift);
	this->cmdfunc(meminfo, NAND_CMD_LOCK_STATUS, -1, page & this->pagemask);

	ret = this->read_byte(meminfo) & (NAND_LOCK_STATUS_TIGHT
					  | NAND_LOCK_STATUS_LOCK
					  | NAND_LOCK_STATUS_UNLOCK);

 out:
	/* de-select the NAND device */
	this->select_chip(meminfo, -1);
	return ret;
}

/**
 * nand_unlock: - Unlock area of NAND pages
 *		  only one consecutive area can be unlocked at one time!
 *
 * @param meminfo	nand mtd instance
 * @param start		start byte address
 * @param length	number of bytes to unlock (must be a multiple of
 *			page size nand->oobblock)
 *
 * @return		0 on success, -1 in case of error
 */
int nand_unlock(nand_info_t *meminfo, ulong start, ulong length)
{
	int ret = 0;
	int chipnr;
	int status;
	int page;
	struct nand_chip *this = meminfo->priv;
	printf ("nand_unlock: start: %08x, length: %d!\n",
		(int)start, (int)length);

	/* select the NAND device */
	chipnr = (int)(start >> this->chip_shift);
	this->select_chip(meminfo, chipnr);

	/* check the WP bit */
	this->cmdfunc(meminfo, NAND_CMD_STATUS, -1, -1);
	if ((this->read_byte(meminfo) & 0x80) == 0) {
		printf ("nand_unlock: Device is write protected!\n");
		ret = -1;
		goto out;
	}

	if ((start & (meminfo->oobblock - 1)) != 0) {
		printf ("nand_unlock: Start address must be beginning of "
			"nand page!\n");
		ret = -1;
		goto out;
	}

	if (length == 0 || (length & (meminfo->oobblock - 1)) != 0) {
		printf ("nand_unlock: Length must be a multiple of nand page "
			"size!\n");
		ret = -1;
		goto out;
	}

	/* submit address of first page to unlock */
	page = (int)(start >> this->page_shift);
	this->cmdfunc(meminfo, NAND_CMD_UNLOCK1, -1, page & this->pagemask);

	/* submit ADDRESS of LAST page to unlock */
	page += (int)(length >> this->page_shift) - 1;
	this->cmdfunc(meminfo, NAND_CMD_UNLOCK2, -1, page & this->pagemask);

	/* call wait ready function */
	status = this->waitfunc(meminfo, this, FL_WRITING);
	/* see if device thinks it succeeded */
	if (status & 0x01) {
		/* there was an error */
		ret = -1;
		goto out;
	}

 out:
	/* de-select the NAND device */
	this->select_chip(meminfo, -1);
	return ret;
}

#endif /* (CONFIG_COMMANDS & CFG_CMD_NAND) && !defined(CFG_NAND_LEGACY) */