summaryrefslogtreecommitdiff
path: root/board/sbc405/strataflash.c
blob: b0d3c6c76faa46baccf23cee7edf0efe2d054a96 (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
/*
 * (C) Copyright 2002
 * Brad Kemp, Seranoa Networks, Brad.Kemp@seranoa.com
 *
 * 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 as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * 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>
#include <asm/processor.h>

#undef  DEBUG_FLASH
/*
 * This file implements a Common Flash Interface (CFI) driver for ppcboot.
 * The width of the port and the width of the chips are determined at initialization.
 * These widths are used to calculate the address for access CFI data structures.
 * It has been tested on an Intel Strataflash implementation.
 *
 * References
 * JEDEC Standard JESD68 - Common Flash Interface (CFI)
 * JEDEC Standard JEP137-A Common Flash Interface (CFI) ID Codes
 * Intel Application Note 646 Common Flash Interface (CFI) and Command Sets
 * Intel 290667-008 3 Volt Intel StrataFlash Memory datasheet
 *
 * TODO
 * Use Primary Extended Query table (PRI) and Alternate Algorithm Query Table (ALT) to determine if protection is available
 * Add support for other command sets Use the PRI and ALT to determine command set
 * Verify erase and program timeouts.
 */

#define FLASH_CMD_CFI			0x98
#define FLASH_CMD_READ_ID		0x90
#define FLASH_CMD_RESET			0xff
#define FLASH_CMD_BLOCK_ERASE		0x20
#define FLASH_CMD_ERASE_CONFIRM		0xD0
#define FLASH_CMD_WRITE			0x40
#define FLASH_CMD_PROTECT		0x60
#define FLASH_CMD_PROTECT_SET		0x01
#define FLASH_CMD_PROTECT_CLEAR		0xD0
#define FLASH_CMD_CLEAR_STATUS		0x50
#define FLASH_CMD_WRITE_TO_BUFFER       0xE8
#define FLASH_CMD_WRITE_BUFFER_CONFIRM  0xD0

#define FLASH_STATUS_DONE		0x80
#define FLASH_STATUS_ESS		0x40
#define FLASH_STATUS_ECLBS		0x20
#define FLASH_STATUS_PSLBS		0x10
#define FLASH_STATUS_VPENS		0x08
#define FLASH_STATUS_PSS		0x04
#define FLASH_STATUS_DPS		0x02
#define FLASH_STATUS_R			0x01
#define FLASH_STATUS_PROTECT		0x01

#define FLASH_OFFSET_CFI		0x55
#define FLASH_OFFSET_CFI_RESP		0x10
#define FLASH_OFFSET_WTOUT		0x1F
#define FLASH_OFFSET_WBTOUT             0x20
#define FLASH_OFFSET_ETOUT		0x21
#define FLASH_OFFSET_CETOUT             0x22
#define FLASH_OFFSET_WMAX_TOUT		0x23
#define FLASH_OFFSET_WBMAX_TOUT         0x24
#define FLASH_OFFSET_EMAX_TOUT		0x25
#define FLASH_OFFSET_CEMAX_TOUT         0x26
#define FLASH_OFFSET_SIZE		0x27
#define FLASH_OFFSET_INTERFACE          0x28
#define FLASH_OFFSET_BUFFER_SIZE        0x2A
#define FLASH_OFFSET_NUM_ERASE_REGIONS	0x2C
#define FLASH_OFFSET_ERASE_REGIONS	0x2D
#define FLASH_OFFSET_PROTECT		0x02
#define FLASH_OFFSET_USER_PROTECTION    0x85
#define FLASH_OFFSET_INTEL_PROTECTION   0x81


#define FLASH_MAN_CFI			0x01000000


typedef union {
	unsigned char c;
	unsigned short w;
	unsigned long l;
} cfiword_t;

typedef union {
	unsigned char * cp;
	unsigned short *wp;
	unsigned long *lp;
} cfiptr_t;

#define NUM_ERASE_REGIONS 4

flash_info_t	flash_info[CONFIG_SYS_MAX_FLASH_BANKS]; /* info for FLASH chips	*/


/*-----------------------------------------------------------------------
 * Functions
 */


static void flash_add_byte(flash_info_t *info, cfiword_t * cword, uchar c);
static void flash_make_cmd(flash_info_t * info, uchar cmd, void * cmdbuf);
static void flash_write_cmd(flash_info_t * info, int sect, uchar offset, uchar cmd);
static int flash_isequal(flash_info_t * info, int sect, uchar offset, uchar cmd);
static int flash_isset(flash_info_t * info, int sect, uchar offset, uchar cmd);
static int flash_detect_cfi(flash_info_t * info);
static ulong flash_get_size (ulong base, int banknum);
static int flash_write_cfiword (flash_info_t *info, ulong dest, cfiword_t cword);
static int flash_full_status_check(flash_info_t * info, ulong sector, ulong tout, char * prompt);
#ifdef CONFIG_SYS_FLASH_USE_BUFFER_WRITE
static int flash_write_cfibuffer(flash_info_t * info, ulong dest, uchar * cp, int len);
#endif
/*-----------------------------------------------------------------------
 * create an address based on the offset and the port width
 */
inline uchar * flash_make_addr(flash_info_t * info, int sect, int offset)
{
	return ((uchar *)(info->start[sect] + (offset * info->portwidth)));
}
/*-----------------------------------------------------------------------
 * read a character at a port width address
 */
inline uchar flash_read_uchar(flash_info_t * info, uchar offset)
{
	uchar *cp;
	cp = flash_make_addr(info, 0, offset);
	return (cp[info->portwidth - 1]);
}

/*-----------------------------------------------------------------------
 * read a short word by swapping for ppc format.
 */
ushort flash_read_ushort(flash_info_t * info, int sect,  uchar offset)
{
    uchar * addr;

    addr = flash_make_addr(info, sect, offset);
    return ((addr[(2*info->portwidth) - 1] << 8) | addr[info->portwidth - 1]);

}

/*-----------------------------------------------------------------------
 * read a long word by picking the least significant byte of each maiximum
 * port size word. Swap for ppc format.
 */
ulong flash_read_long(flash_info_t * info, int sect,  uchar offset)
{
    uchar * addr;

    addr = flash_make_addr(info, sect, offset);
    return ( (addr[(2*info->portwidth) - 1] << 24 ) | (addr[(info->portwidth) -1] << 16) |
	    (addr[(4*info->portwidth) - 1] << 8) | addr[(3*info->portwidth) - 1]);

}

/*-----------------------------------------------------------------------
 */
unsigned long flash_init (void)
{
	unsigned long size;
	int i;
	unsigned long  address;


	/* The flash is positioned back to back, with the demultiplexing of the chip
	 * based on the A24 address line.
	 *
	 */

	address = CONFIG_SYS_FLASH_BASE;
	size = 0;

	/* Init: no FLASHes known */
	for (i=0; i<CONFIG_SYS_MAX_FLASH_BANKS; ++i) {
		flash_info[i].flash_id = FLASH_UNKNOWN;
		size += flash_info[i].size = flash_get_size(address, i);
		address += CONFIG_SYS_FLASH_INCREMENT;
		if (flash_info[0].flash_id == FLASH_UNKNOWN) {
			printf ("## Unknown FLASH on Bank %d - Size = 0x%08lx = %ld MB\n",i,
				flash_info[0].size, flash_info[i].size<<20);
		}
	}

#if 0 /* test-only */
	/* Monitor protection ON by default */
#if (CONFIG_SYS_MONITOR_BASE >= CONFIG_SYS_FLASH_BASE)
	for(i=0; flash_info[0].start[i] < CONFIG_SYS_MONITOR_BASE+CONFIG_SYS_MONITOR_LEN-1; i++)
		(void)flash_real_protect(&flash_info[0], i, 1);
#endif
#else
	/* monitor protection ON by default */
	flash_protect (FLAG_PROTECT_SET,
		       - CONFIG_SYS_MONITOR_LEN,
		       - 1, &flash_info[1]);
#endif

	return (size);
}

/*-----------------------------------------------------------------------
 */
int flash_erase (flash_info_t *info, int s_first, int s_last)
{
	int rcode = 0;
	int prot;
	int sect;

	if( info->flash_id != FLASH_MAN_CFI) {
		printf ("Can't erase unknown flash type - aborted\n");
		return 1;
	}
	if ((s_first < 0) || (s_first > s_last)) {
		printf ("- no sectors to erase\n");
		return 1;
	}

	prot = 0;
	for (sect=s_first; sect<=s_last; ++sect) {
		if (info->protect[sect]) {
			prot++;
		}
	}
	if (prot) {
		printf ("- Warning: %d protected sectors will not be erased!\n",
			prot);
	} else {
		printf ("\n");
	}


	for (sect = s_first; sect<=s_last; sect++) {
		if (info->protect[sect] == 0) { /* not protected */
			flash_write_cmd(info, sect, 0, FLASH_CMD_CLEAR_STATUS);
			flash_write_cmd(info, sect, 0, FLASH_CMD_BLOCK_ERASE);
			flash_write_cmd(info, sect, 0, FLASH_CMD_ERASE_CONFIRM);

			if(flash_full_status_check(info, sect, info->erase_blk_tout, "erase")) {
				rcode = 1;
			} else
				printf(".");
		}
	}
	printf (" done\n");
	return rcode;
}

/*-----------------------------------------------------------------------
 */
void flash_print_info  (flash_info_t *info)
{
	int i;

	if (info->flash_id != FLASH_MAN_CFI) {
		printf ("missing or unknown FLASH type\n");
		return;
	}

	printf("CFI conformant FLASH (%d x %d)",
	       (info->portwidth	 << 3 ), (info->chipwidth  << 3 ));
	printf ("  Size: %ld MB in %d Sectors\n",
		info->size >> 20, info->sector_count);
	printf(" Erase timeout %ld ms, write timeout %ld ms, buffer write timeout %ld ms, buffer size %d\n",
	       info->erase_blk_tout, info->write_tout, info->buffer_write_tout, info->buffer_size);

	printf ("  Sector Start Addresses:");
	for (i=0; i<info->sector_count; ++i) {
#ifdef CONFIG_SYS_FLASH_EMPTY_INFO
		int k;
		int size;
		int erased;
		volatile unsigned long *flash;

		/*
		 * Check if whole sector is erased
		 */
		if (i != (info->sector_count-1))
		  size = info->start[i+1] - info->start[i];
		else
		  size = info->start[0] + info->size - info->start[i];
		erased = 1;
		flash = (volatile unsigned long *)info->start[i];
		size = size >> 2;        /* divide by 4 for longword access */
		for (k=0; k<size; k++)
		  {
		    if (*flash++ != 0xffffffff)
		      {
			erased = 0;
			break;
		      }
		  }

		if ((i % 5) == 0)
			printf ("\n   ");
		/* print empty and read-only info */
		printf (" %08lX%s%s",
			info->start[i],
			erased ? " E" : "  ",
			info->protect[i] ? "RO " : "   ");
#else
		if ((i % 5) == 0)
			printf ("\n   ");
		printf (" %08lX%s",
			info->start[i],
			info->protect[i] ? " (RO)" : "     ");
#endif
	}
	printf ("\n");
	return;
}

/*-----------------------------------------------------------------------
 * Copy memory to flash, returns:
 * 0 - OK
 * 1 - write timeout
 * 2 - Flash not erased
 */
int write_buff (flash_info_t *info, uchar *src, ulong addr, ulong cnt)
{
	ulong wp;
	ulong cp;
	int aln;
	cfiword_t cword;
	int i, rc;

	/* get lower aligned address */
	wp = (addr & ~(info->portwidth - 1));

	/* handle unaligned start */
	if((aln = addr - wp) != 0) {
		cword.l = 0;
		cp = wp;
		for(i=0;i<aln; ++i, ++cp)
			flash_add_byte(info, &cword, (*(uchar *)cp));

		for(; (i< info->portwidth) && (cnt > 0) ; i++) {
			flash_add_byte(info, &cword, *src++);
			cnt--;
			cp++;
		}
		for(; (cnt == 0) && (i < info->portwidth); ++i, ++cp)
			flash_add_byte(info, &cword, (*(uchar *)cp));
		if((rc = flash_write_cfiword(info, wp, cword)) != 0)
			return rc;
		wp = cp;
	}

#ifdef CONFIG_SYS_FLASH_USE_BUFFER_WRITE
	while(cnt >= info->portwidth) {
		i = info->buffer_size > cnt? cnt: info->buffer_size;
		if((rc = flash_write_cfibuffer(info, wp, src,i)) != ERR_OK)
			return rc;
		wp += i;
		src += i;
		cnt -=i;
	}
#else
	/* handle the aligned part */
	while(cnt >= info->portwidth) {
		cword.l = 0;
		for(i = 0; i < info->portwidth; i++) {
			flash_add_byte(info, &cword, *src++);
		}
		if((rc = flash_write_cfiword(info, wp, cword)) != 0)
			return rc;
		wp += info->portwidth;
		cnt -= info->portwidth;
	}
#endif /* CONFIG_SYS_FLASH_USE_BUFFER_WRITE */
	if (cnt == 0) {
		return (0);
	}

	/*
	 * handle unaligned tail bytes
	 */
	cword.l = 0;
	for (i=0, cp=wp; (i<info->portwidth) && (cnt>0); ++i, ++cp) {
		flash_add_byte(info, &cword, *src++);
		--cnt;
	}
	for (; i<info->portwidth; ++i, ++cp) {
		flash_add_byte(info, & cword, (*(uchar *)cp));
	}

	return flash_write_cfiword(info, wp, cword);
}

/*-----------------------------------------------------------------------
 */
int flash_real_protect(flash_info_t *info, long sector, int prot)
{
	int retcode = 0;

	flash_write_cmd(info, sector, 0, FLASH_CMD_CLEAR_STATUS);
	flash_write_cmd(info, sector, 0, FLASH_CMD_PROTECT);
	if(prot)
		flash_write_cmd(info, sector, 0, FLASH_CMD_PROTECT_SET);
	else
		flash_write_cmd(info, sector, 0, FLASH_CMD_PROTECT_CLEAR);

	if((retcode = flash_full_status_check(info, sector, info->erase_blk_tout,
					 prot?"protect":"unprotect")) == 0) {

		info->protect[sector] = prot;
		/* Intel's unprotect unprotects all locking */
		if(prot == 0) {
			int i;
			for(i = 0 ; i<info->sector_count; i++) {
				if(info->protect[i])
					flash_real_protect(info, i, 1);
			}
		}
	}

	return retcode;
}
/*-----------------------------------------------------------------------
 *  wait for XSR.7 to be set. Time out with an error if it does not.
 *  This routine does not set the flash to read-array mode.
 */
static int flash_status_check(flash_info_t * info, ulong sector, ulong tout, char * prompt)
{
	ulong start;

	/* Wait for command completion */
	start = get_timer (0);
	while(!flash_isset(info, sector, 0, FLASH_STATUS_DONE)) {
		if (get_timer(start) > info->erase_blk_tout) {
			printf("Flash %s timeout at address %lx\n", prompt, info->start[sector]);
			flash_write_cmd(info, sector, 0, FLASH_CMD_RESET);
			return ERR_TIMOUT;
		}
	}
	return ERR_OK;
}
/*-----------------------------------------------------------------------
 * Wait for XSR.7 to be set, if it times out print an error, otherwise do a full status check.
 * This routine sets the flash to read-array mode.
 */
static int flash_full_status_check(flash_info_t * info, ulong sector, ulong tout, char * prompt)
{
	int retcode;
	retcode = flash_status_check(info, sector, tout, prompt);
	if((retcode == ERR_OK) && !flash_isequal(info,sector, 0, FLASH_STATUS_DONE)) {
		retcode = ERR_INVAL;
		printf("Flash %s error at address %lx\n", prompt,info->start[sector]);
		if(flash_isset(info, sector, 0, FLASH_STATUS_ECLBS | FLASH_STATUS_PSLBS)){
			printf("Command Sequence Error.\n");
		} else if(flash_isset(info, sector, 0, FLASH_STATUS_ECLBS)){
			printf("Block Erase Error.\n");
			retcode = ERR_NOT_ERASED;
		} else if (flash_isset(info, sector, 0, FLASH_STATUS_PSLBS)) {
			printf("Locking Error\n");
		}
		if(flash_isset(info, sector, 0, FLASH_STATUS_DPS)){
			printf("Block locked.\n");
			retcode = ERR_PROTECTED;
		}
		if(flash_isset(info, sector, 0, FLASH_STATUS_VPENS))
			printf("Vpp Low Error.\n");
	}
	flash_write_cmd(info, sector, 0, FLASH_CMD_RESET);
	return retcode;
}
/*-----------------------------------------------------------------------
 */
static void flash_add_byte(flash_info_t *info, cfiword_t * cword, uchar c)
{
	switch(info->portwidth) {
	case FLASH_CFI_8BIT:
		cword->c = c;
		break;
	case FLASH_CFI_16BIT:
		cword->w = (cword->w << 8) | c;
		break;
	case FLASH_CFI_32BIT:
		cword->l = (cword->l << 8) | c;
	}
}


/*-----------------------------------------------------------------------
 * make a proper sized command based on the port and chip widths
 */
static void flash_make_cmd(flash_info_t * info, uchar cmd, void * cmdbuf)
{
	int i;
	uchar *cp = (uchar *)cmdbuf;
	for(i=0; i< info->portwidth; i++)
		*cp++ = ((i+1) % info->chipwidth) ? '\0':cmd;
}

/*
 * Write a proper sized command to the correct address
 */
static void flash_write_cmd(flash_info_t * info, int sect, uchar offset, uchar cmd)
{

	volatile cfiptr_t addr;
	cfiword_t cword;
	addr.cp = flash_make_addr(info, sect, offset);
	flash_make_cmd(info, cmd, &cword);
	switch(info->portwidth) {
	case FLASH_CFI_8BIT:
		*addr.cp = cword.c;
		break;
	case FLASH_CFI_16BIT:
		*addr.wp = cword.w;
		break;
	case FLASH_CFI_32BIT:
		*addr.lp = cword.l;
		break;
	}
}

/*-----------------------------------------------------------------------
 */
static int flash_isequal(flash_info_t * info, int sect, uchar offset, uchar cmd)
{
	cfiptr_t cptr;
	cfiword_t cword;
	int retval;
	cptr.cp = flash_make_addr(info, sect, offset);
	flash_make_cmd(info, cmd, &cword);
	switch(info->portwidth) {
	case FLASH_CFI_8BIT:
		retval = (cptr.cp[0] == cword.c);
		break;
	case FLASH_CFI_16BIT:
		retval = (cptr.wp[0] == cword.w);
		break;
	case FLASH_CFI_32BIT:
		retval = (cptr.lp[0] == cword.l);
		break;
	default:
		retval = 0;
		break;
	}
	return retval;
}
/*-----------------------------------------------------------------------
 */
static int flash_isset(flash_info_t * info, int sect, uchar offset, uchar cmd)
{
	cfiptr_t cptr;
	cfiword_t cword;
	int retval;
	cptr.cp = flash_make_addr(info, sect, offset);
	flash_make_cmd(info, cmd, &cword);
	switch(info->portwidth) {
	case FLASH_CFI_8BIT:
		retval = ((cptr.cp[0] & cword.c) == cword.c);
		break;
	case FLASH_CFI_16BIT:
		retval = ((cptr.wp[0] & cword.w) == cword.w);
		break;
	case FLASH_CFI_32BIT:
		retval = ((cptr.lp[0] & cword.l) == cword.l);
		break;
	default:
		retval = 0;
		break;
	}
	return retval;
}

/*-----------------------------------------------------------------------
 * detect if flash is compatible with the Common Flash Interface (CFI)
 * http://www.jedec.org/download/search/jesd68.pdf
 *
*/
static int flash_detect_cfi(flash_info_t * info)
{

	for(info->portwidth=FLASH_CFI_8BIT; info->portwidth <= FLASH_CFI_32BIT;
	    info->portwidth <<= 1) {
		for(info->chipwidth =FLASH_CFI_BY8;
		    info->chipwidth <= info->portwidth;
		    info->chipwidth <<= 1) {
			flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
			flash_write_cmd(info, 0, FLASH_OFFSET_CFI, FLASH_CMD_CFI);
			if(flash_isequal(info, 0, FLASH_OFFSET_CFI_RESP,'Q') &&
			   flash_isequal(info, 0, FLASH_OFFSET_CFI_RESP + 1, 'R') &&
			   flash_isequal(info, 0, FLASH_OFFSET_CFI_RESP + 2, 'Y'))
				return 1;
		}
	}
	return 0;
}
/*
 * The following code cannot be run from FLASH!
 *
 */
static ulong flash_get_size (ulong base, int banknum)
{
	flash_info_t * info = &flash_info[banknum];
	int i, j;
	int sect_cnt;
	unsigned long sector;
	unsigned long tmp;
	int size_ratio;
	uchar num_erase_regions;
	int  erase_region_size;
	int  erase_region_count;

	info->start[0] = base;

	if(flash_detect_cfi(info)){
#ifdef DEBUG_FLASH
		printf("portwidth=%d chipwidth=%d\n", info->portwidth, info->chipwidth); /* test-only */
#endif
		size_ratio = info->portwidth / info->chipwidth;
		num_erase_regions = flash_read_uchar(info, FLASH_OFFSET_NUM_ERASE_REGIONS);
#ifdef DEBUG_FLASH
		printf("found %d erase regions\n", num_erase_regions);
#endif
		sect_cnt = 0;
		sector = base;
		for(i = 0 ; i < num_erase_regions; i++) {
			if(i > NUM_ERASE_REGIONS) {
				printf("%d erase regions found, only %d used\n",
				       num_erase_regions, NUM_ERASE_REGIONS);
				break;
			}
			tmp = flash_read_long(info, 0, FLASH_OFFSET_ERASE_REGIONS);
			erase_region_size = (tmp & 0xffff)? ((tmp & 0xffff) * 256): 128;
			tmp >>= 16;
			erase_region_count = (tmp & 0xffff) +1;
			for(j = 0; j< erase_region_count; j++) {
				info->start[sect_cnt] = sector;
				sector += (erase_region_size * size_ratio);
				info->protect[sect_cnt] = flash_isset(info, sect_cnt, FLASH_OFFSET_PROTECT, FLASH_STATUS_PROTECT);
				sect_cnt++;
			}
		}

		info->sector_count = sect_cnt;
		/* multiply the size by the number of chips */
		info->size = (1 << flash_read_uchar(info, FLASH_OFFSET_SIZE)) * size_ratio;
		info->buffer_size = (1 << flash_read_ushort(info, 0, FLASH_OFFSET_BUFFER_SIZE));
		tmp = 1 << flash_read_uchar(info, FLASH_OFFSET_ETOUT);
		info->erase_blk_tout = (tmp * (1 << flash_read_uchar(info, FLASH_OFFSET_EMAX_TOUT)));
		tmp = 1 << flash_read_uchar(info, FLASH_OFFSET_WBTOUT);
		info->buffer_write_tout = (tmp * (1 << flash_read_uchar(info, FLASH_OFFSET_WBMAX_TOUT)));
		tmp = 1 << flash_read_uchar(info, FLASH_OFFSET_WTOUT);
		info->write_tout = (tmp * (1 << flash_read_uchar(info, FLASH_OFFSET_WMAX_TOUT)))/ 1000;
		info->flash_id = FLASH_MAN_CFI;
	}

	flash_write_cmd(info, 0, 0, FLASH_CMD_RESET);
	return(info->size);
}


/*-----------------------------------------------------------------------
 */
static int flash_write_cfiword (flash_info_t *info, ulong dest, cfiword_t cword)
{

	cfiptr_t cptr;
	int flag;

	cptr.cp = (uchar *)dest;

	/* Check if Flash is (sufficiently) erased */
	switch(info->portwidth) {
	case FLASH_CFI_8BIT:
		flag = ((cptr.cp[0] & cword.c) == cword.c);
		break;
	case FLASH_CFI_16BIT:
		flag = ((cptr.wp[0] & cword.w) == cword.w);
		break;
	case FLASH_CFI_32BIT:
		flag = ((cptr.lp[0] & cword.l)	== cword.l);
		break;
	default:
		return 2;
	}
	if(!flag)
		return 2;

	/* Disable interrupts which might cause a timeout here */
	flag = disable_interrupts();

	flash_write_cmd(info, 0, 0, FLASH_CMD_CLEAR_STATUS);
	flash_write_cmd(info, 0, 0, FLASH_CMD_WRITE);

	switch(info->portwidth) {
	case FLASH_CFI_8BIT:
		cptr.cp[0] = cword.c;
		break;
	case FLASH_CFI_16BIT:
		cptr.wp[0] = cword.w;
		break;
	case FLASH_CFI_32BIT:
		cptr.lp[0] = cword.l;
		break;
	}

	/* re-enable interrupts if necessary */
	if(flag)
		enable_interrupts();

	return flash_full_status_check(info, 0, info->write_tout, "write");
}

#ifdef CONFIG_SYS_FLASH_USE_BUFFER_WRITE

/* loop through the sectors from the highest address
 * when the passed address is greater or equal to the sector address
 * we have a match
 */
static int find_sector(flash_info_t *info, ulong addr)
{
	int sector;
	for(sector = info->sector_count - 1; sector >= 0; sector--) {
		if(addr >= info->start[sector])
			break;
	}
	return sector;
}

static int flash_write_cfibuffer(flash_info_t * info, ulong dest, uchar * cp, int len)
{

	int sector;
	int cnt;
	int retcode;
	volatile cfiptr_t src;
	volatile cfiptr_t dst;

	src.cp = cp;
	dst.cp = (uchar *)dest;
	sector = find_sector(info, dest);
	flash_write_cmd(info, sector, 0, FLASH_CMD_CLEAR_STATUS);
	flash_write_cmd(info, sector, 0, FLASH_CMD_WRITE_TO_BUFFER);
	if((retcode = flash_status_check(info, sector, info->buffer_write_tout,
					 "write to buffer")) == ERR_OK) {
		switch(info->portwidth) {
		case FLASH_CFI_8BIT:
			cnt = len;
			break;
		case FLASH_CFI_16BIT:
			cnt = len >> 1;
			break;
		case FLASH_CFI_32BIT:
			cnt = len >> 2;
			break;
		default:
			return ERR_INVAL;
			break;
		}
		flash_write_cmd(info, sector, 0, (uchar)cnt-1);
		while(cnt-- > 0) {
			switch(info->portwidth) {
			case FLASH_CFI_8BIT:
				*dst.cp++ = *src.cp++;
				break;
			case FLASH_CFI_16BIT:
				*dst.wp++ = *src.wp++;
				break;
			case FLASH_CFI_32BIT:
				*dst.lp++ = *src.lp++;
				break;
			default:
				return ERR_INVAL;
				break;
			}
		}
		flash_write_cmd(info, sector, 0, FLASH_CMD_WRITE_BUFFER_CONFIRM);
		retcode = flash_full_status_check(info, sector, info->buffer_write_tout,
					     "buffer write");
	}
	flash_write_cmd(info, sector, 0, FLASH_CMD_CLEAR_STATUS);
	return retcode;
}
#endif /* CONFIG_SYS_USE_FLASH_BUFFER_WRITE */