summaryrefslogtreecommitdiffstats
path: root/board/trab/cmd_trab.c
blob: 7dd97a1cb4e105f631314ca4b9b9eec14404c984 (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
/*
 * (C) Copyright 2003
 * Martin Krause, TQ-Systems GmbH, martin.krause@tqs.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 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
 */

#undef DEBUG

#include <common.h>
#include <command.h>
#include <s3c2400.h>
#include <rtc.h>

/*
 * TRAB board specific commands. Especially commands for burn-in and function
 * test.
 */
#if (CONFIG_COMMANDS & CFG_CMD_BSP) || defined(CONFIG_CMD_BSP)

/* limits for valid range of VCC5V in mV  */
#define VCC5V_MIN       4500
#define VCC5V_MAX       5500

/*
 * Test strings for EEPROM test. Length of string 2 must not exceed length of
 * string 1. Otherwise a buffer overrun could occur!
 */
#define EEPROM_TEST_STRING_1    "0987654321 :tset a si siht"
#define EEPROM_TEST_STRING_2    "this is a test: 1234567890"

/*
 * min/max limits for valid contact temperature during burn in test (in
 * degree Centigrade * 100)
 */
#define MIN_CONTACT_TEMP        -1000
#define MAX_CONTACT_TEMP        +9000

/* blinking frequency of status LED */
#define LED_BLINK_FREQ          5

/* delay time between burn in cycles in seconds */
#ifndef BURN_IN_CYCLE_DELAY     /* if not defined in include/configs/trab.h */
#define BURN_IN_CYCLE_DELAY     5
#endif

/* physical SRAM parameters */
#define SRAM_ADDR       0x02000000 /* GCS1 */
#define SRAM_SIZE       0x40000 /* 256 kByte */

/* CPLD-Register for controlling TRAB hardware functions */
#define CPLD_BUTTONS            ((volatile unsigned long *)0x04020000)
#define CPLD_FILL_LEVEL         ((volatile unsigned long *)0x04008000)
#define CPLD_ROTARY_SWITCH      ((volatile unsigned long *)0x04018000)
#define CPLD_RS485_RE           ((volatile unsigned long *)0x04028000)

/* I2C EEPROM device address */
#define I2C_EEPROM_DEV_ADDR     0x54

/* EEPROM address map */
#define EE_ADDR_TEST                    192
#define EE_ADDR_MAX_CYCLES              256
#define EE_ADDR_STATUS                  258
#define EE_ADDR_PASS_CYCLES             259
#define EE_ADDR_FIRST_ERROR_CYCLE       261
#define EE_ADDR_FIRST_ERROR_NUM         263
#define EE_ADDR_FIRST_ERROR_NAME        264
#define EE_ADDR_ACT_CYCLE               280

/* Bit definitions for ADCCON */
#define ADC_ENABLE_START     0x1
#define ADC_READ_START       0x2
#define ADC_STDBM            0x4
#define ADC_INP_AIN0         (0x0 << 3)
#define ADC_INP_AIN1         (0x1 << 3)
#define ADC_INP_AIN2         (0x2 << 3)
#define ADC_INP_AIN3         (0x3 << 3)
#define ADC_INP_AIN4         (0x4 << 3)
#define ADC_INP_AIN5         (0x5 << 3)
#define ADC_INP_AIN6         (0x6 << 3)
#define ADC_INP_AIN7         (0x7 << 3)
#define ADC_PRSCEN           0x4000
#define ADC_ECFLG            0x800

/* misc */

/* externals */
extern int memory_post_tests (unsigned long start, unsigned long size);
extern int i2c_write (uchar, uint, int , uchar* , int);
extern int i2c_read (uchar, uint, int , uchar* , int);
extern void tsc2000_reg_init (void);
extern s32 tsc2000_contact_temp (void);
extern void spi_init(void);

/* function declarations */
int do_dip (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
int do_vcc5v (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
int do_burn_in (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
int do_contact_temp (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
int do_burn_in_status (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);
int i2c_write_multiple (uchar chip, uint addr, int alen,
			uchar *buffer, int len);
int i2c_read_multiple (uchar chip, uint addr, int alen,
			uchar *buffer, int len);
int do_temp_log (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[]);

/* helper functions */
static void adc_init (void);
static int adc_read (unsigned int channel);
static int read_dip (void);
static int read_vcc5v (void);
static int test_dip (void);
static int test_vcc5v (void);
static int test_rotary_switch (void);
static int test_sram (void);
static int test_eeprom (void);
static int test_contact_temp (void);
static void led_set (unsigned int);
static void led_blink (void);
static void led_init (void);
static void sdelay (unsigned long seconds); /* delay in seconds */
static int dummy (void);
static int read_max_cycles(void);
static void test_function_table_init (void);
static void global_vars_init (void);
static int global_vars_write_to_eeprom (void);

/* globals */
u16 max_cycles;
u8 status;
u16 pass_cycles;
u16 first_error_cycle;
u8 first_error_num;
char first_error_name[16];
u16 act_cycle;

typedef struct test_function_s {
	char *name;
	int (*pf)(void);
} test_function_t;

/* max number of Burn In Functions */
#define BIF_MAX 6

/* table with burn in functions */
test_function_t test_function[BIF_MAX];


int do_burn_in (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	int i;
	int cycle_status;

	if (argc > 1) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	led_init ();
	global_vars_init ();
	test_function_table_init ();
	spi_init ();

	if (global_vars_write_to_eeprom () != 0) {
		printf ("%s: error writing global_vars to eeprom\n",
			__FUNCTION__);
		return (1);
	}

	if (read_max_cycles () != 0) {
		printf ("%s: error reading max_cycles from eeprom\n",
			__FUNCTION__);
		return (1);
	}

	if (max_cycles == 0) {
		printf ("%s: error, burn in max_cycles = 0\n", __FUNCTION__);
		return (1);
	}

	status = 0;
	for (act_cycle = 1; act_cycle <= max_cycles; act_cycle++) {

		cycle_status = 0;

		/*
		 * avoid timestamp overflow problem after about 68 minutes of
		 * udelay() time.
		 */
		reset_timer_masked ();
		for (i = 0; i < BIF_MAX; i++) {

			/* call test function */
			if ((*test_function[i].pf)() != 0) {
				printf ("error in %s test\n",
					test_function[i].name);

				/* is it the first error? */
				if (status == 0) {
					status = 1;
					first_error_cycle = act_cycle;

					/* do not use error_num 0 */
					first_error_num = i+1;
					strncpy (first_error_name,
						 test_function[i].name,
						 sizeof (first_error_name));
					led_set (0);
				}
				cycle_status = 1;
			}
		}
		/* were all tests of actual cycle OK? */
		if (cycle_status == 0)
			pass_cycles++;

		/* set status LED if no error is occoured since yet */
		if (status == 0)
			led_set (1);

		printf ("%s: cycle %d finished\n", __FUNCTION__, act_cycle);

		/* pause between cycles */
		sdelay (BURN_IN_CYCLE_DELAY);
	}

	if (global_vars_write_to_eeprom () != 0) {
		led_set (0);
		printf ("%s: error writing global_vars to eeprom\n",
			__FUNCTION__);
		status = 1;
	}

	if (status == 0) {
		led_blink ();   /* endless loop!! */
		return (0);
	} else {
		led_set (0);
		return (1);
	}
}

U_BOOT_CMD(
	burn_in,	1,	1,	do_burn_in,
	"burn_in - start burn-in test application on TRAB\n",
	"\n"
	"    -  start burn-in test application\n"
	"       The burn-in test could took a while to finish!\n"
	"       The content of the onboard EEPROM is modified!\n"
);


int do_dip (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	int i, dip;

	if (argc > 1) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	if ((dip = read_dip ()) == -1) {
		return 1;
	}

	for (i = 0; i < 4; i++) {
		if ((dip & (1 << i)) == 0)
			printf("0");
		else
			printf("1");
	}
	printf("\n");

	return 0;
}

U_BOOT_CMD(
	dip,	1,	1,	do_dip,
	"dip     - read dip switch on TRAB\n",
	"\n"
	"    - read state of dip switch (S1) on TRAB board\n"
	"      read sequence: 1-2-3-4; ON=1; OFF=0; e.g.: \"0100\"\n"
);


int do_vcc5v (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	int vcc5v;

	if (argc > 1) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	if ((vcc5v = read_vcc5v ()) == -1) {
		return (1);
	}

	printf ("%d", (vcc5v / 1000));
	printf (".%d", (vcc5v % 1000) / 100);
	printf ("%d V\n", (vcc5v % 100) / 10) ;

	return 0;
}

U_BOOT_CMD(
	vcc5v,	1,	1,	do_vcc5v,
	"vcc5v   - read VCC5V on TRAB\n",
	"\n"
	"    - read actual value of voltage VCC5V\n"
);


int do_contact_temp (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	int contact_temp;

	if (argc > 1) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	spi_init ();

	contact_temp = tsc2000_contact_temp();
	printf ("%d degree C * 100\n", contact_temp) ;

	return 0;
}

U_BOOT_CMD(
	c_temp,	1,	1,	do_contact_temp,
	"c_temp  - read contact temperature on TRAB\n",
	"\n"
	"    -  reads the onboard temperature (=contact temperature)\n"
);


int do_burn_in_status (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	if (argc > 1) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_STATUS, 1,
				(unsigned char*) &status, 1)) {
		return (1);
	}
	if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_PASS_CYCLES, 1,
				(unsigned char*) &pass_cycles, 2)) {
		return (1);
	}
	if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_FIRST_ERROR_CYCLE,
				1, (unsigned char*) &first_error_cycle, 2)) {
		return (1);
	}
	if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_FIRST_ERROR_NUM,
				1, (unsigned char*) &first_error_num, 1)) {
		return (1);
	}
	if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_FIRST_ERROR_NAME,
			       1, (unsigned char*)first_error_name,
			       sizeof (first_error_name))) {
		return (1);
	}

	if (read_max_cycles () != 0) {
		return (1);
	}

	printf ("max_cycles = %d\n", max_cycles);
	printf ("status = %d\n", status);
	printf ("pass_cycles = %d\n", pass_cycles);
	printf ("first_error_cycle = %d\n", first_error_cycle);
	printf ("first_error_num = %d\n", first_error_num);
	printf ("first_error_name = %.*s\n",(int) sizeof(first_error_name),
		first_error_name);

	return 0;
}

U_BOOT_CMD(
	bis,	1,	1,	do_burn_in_status,
	"bis     - print burn in status on TRAB\n",
	"\n"
	"    -  prints the status variables of the last burn in test\n"
	"       stored in the onboard EEPROM on TRAB board\n"
);

static int read_dip (void)
{
	unsigned int result = 0;
	int adc_val;
	int i;

	/***********************************************************
	 DIP switch connection (according to wa4-cpu.sp.301.pdf, page 3):
	   SW1 - AIN4
	   SW2 - AIN5
	   SW3 - AIN6
	   SW4 - AIN7

	   "On" DIP switch position short-circuits the voltage from
	   the input channel (i.e. '0' conversion result means "on").
	*************************************************************/

	for (i = 7; i > 3; i--) {

		if ((adc_val = adc_read (i)) == -1) {
			printf ("%s: Channel %d could not be read\n",
				 __FUNCTION__, i);
			return (-1);
		}

		/*
		 * Input voltage (switch open) is 1.8 V.
		 * (Vin_High/VRef)*adc_res = (1,8V/2,5V)*1023) = 736
		 * Set trigger at halve that value.
		 */
		if (adc_val < 368)
			result |= (1 << (i-4));
	}
	return (result);
}


static int read_vcc5v (void)
{
	s32 result;

	/* VCC5V is connected to channel 2 */

	if ((result = adc_read (2)) == -1) {
		printf ("%s: VCC5V could not be read\n", __FUNCTION__);
		return (-1);
	}
	/*
	 * Calculate voltage value. Split in two parts because there is no
	 * floating point support.  VCC5V is connected over an resistor divider:
	 * VCC5V=ADCval*2,5V/1023*(10K+30K)/10K.
	 */
	result = result * 10 * 1000 / 1023; /* result in mV */

	return (result);
}


static int test_dip (void)
{
	static int first_run = 1;
	static int first_dip;

	if (first_run) {
		if ((first_dip = read_dip ()) == -1) {
			return (1);
		}
		first_run = 0;
		debug ("%s: first_dip=%d\n", __FUNCTION__, first_dip);
	}
	if (first_dip != read_dip ()) {
		return (1);
	} else {
		return (0);
	}
}


static int test_vcc5v (void)
{
	int vcc5v;

	if ((vcc5v = read_vcc5v ()) == -1) {
		return (1);
	}

	if ((vcc5v > VCC5V_MAX) || (vcc5v < VCC5V_MIN)) {
		printf ("%s: vcc5v[V/100]=%d\n", __FUNCTION__, vcc5v);
		return (1);
	} else {
		return (0);
	}
}


static int test_rotary_switch (void)
{
	static int first_run = 1;
	static int first_rs;

	if (first_run) {
		/*
		 * clear bits in CPLD, because they have random values after
		 * power-up or reset.
		 */
		*CPLD_ROTARY_SWITCH |= (1 << 16) | (1 << 17);

		first_rs = ((*CPLD_ROTARY_SWITCH >> 16) & 0x7);
		first_run = 0;
		debug ("%s: first_rs=%d\n", __FUNCTION__, first_rs);
	}

	if (first_rs != ((*CPLD_ROTARY_SWITCH >> 16) & 0x7)) {
		return (1);
	} else {
		return (0);
	}
}


static int test_sram (void)
{
	return (memory_post_tests (SRAM_ADDR, SRAM_SIZE));
}


static int test_eeprom (void)
{
	unsigned char temp[sizeof (EEPROM_TEST_STRING_1)];
	int result = 0;

	/* write test string 1, read back and verify */
	if (i2c_write_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_TEST, 1,
				(unsigned char*)EEPROM_TEST_STRING_1,
				sizeof (EEPROM_TEST_STRING_1))) {
		return (1);
	}

	if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_TEST, 1,
			       temp, sizeof (EEPROM_TEST_STRING_1))) {
		return (1);
	}

	if (strcmp ((char *)temp, EEPROM_TEST_STRING_1) != 0) {
		result = 1;
		printf ("%s: error; read_str = \"%s\"\n", __FUNCTION__, temp);
	}

	/* write test string 2, read back and verify */
	if (result == 0) {
		if (i2c_write_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_TEST, 1,
					(unsigned char*)EEPROM_TEST_STRING_2,
					sizeof (EEPROM_TEST_STRING_2))) {
			return (1);
		}

		if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_TEST, 1,
				       temp, sizeof (EEPROM_TEST_STRING_2))) {
			return (1);
		}

		if (strcmp ((char *)temp, EEPROM_TEST_STRING_2) != 0) {
			result = 1;
			printf ("%s: error; read str = \"%s\"\n",
				__FUNCTION__, temp);
		}
	}
	return (result);
}


static int test_contact_temp (void)
{
	int contact_temp;

	contact_temp = tsc2000_contact_temp ();

	if ((contact_temp < MIN_CONTACT_TEMP)
	    || (contact_temp > MAX_CONTACT_TEMP))
		return (1);
	else
		return (0);
}


int i2c_write_multiple (uchar chip, uint addr, int alen,
			uchar *buffer, int len)
{
	int i;

	if (alen != 1) {
		printf ("%s: addr len other than 1 not supported\n",
			 __FUNCTION__);
		return (1);
	}

	for (i = 0; i < len; i++) {
		if (i2c_write (chip, addr+i, alen, buffer+i, 1)) {
			printf ("%s: could not write to i2c device %d"
				 ", addr %d\n", __FUNCTION__, chip, addr);
			return (1);
		}
#if 0
		printf ("chip=%#x, addr+i=%#x+%d=%p, alen=%d, *buffer+i="
			"%#x+%d=%p=\"%.1s\"\n", chip, addr, i, addr+i,
			alen, buffer, i, buffer+i, buffer+i);
#endif

		udelay (30000);
	}
	return (0);
}


int i2c_read_multiple ( uchar chip, uint addr, int alen,
			uchar *buffer, int len)
{
	int i;

	if (alen != 1) {
		printf ("%s: addr len other than 1 not supported\n",
			 __FUNCTION__);
		return (1);
	}

	for (i = 0; i < len; i++) {
		if (i2c_read (chip, addr+i, alen, buffer+i, 1)) {
			printf ("%s: could not read from i2c device %#x"
				 ", addr %d\n", __FUNCTION__, chip, addr);
			return (1);
		}
	}
	return (0);
}


static int adc_read (unsigned int channel)
{
	int j = 1000; /* timeout value for wait loop in us */
	int result;
	S3C2400_ADC *padc;

	padc = S3C2400_GetBase_ADC();
	channel &= 0x7;

	adc_init ();

	padc->ADCCON &= ~ADC_STDBM; /* select normal mode */
	padc->ADCCON &= ~(0x7 << 3); /* clear the channel bits */
	padc->ADCCON |= ((channel << 3) | ADC_ENABLE_START);

	while (j--) {
		if ((padc->ADCCON & ADC_ENABLE_START) == 0)
			break;
		udelay (1);
	}

	if (j == 0) {
		printf("%s: ADC timeout\n", __FUNCTION__);
		padc->ADCCON |= ADC_STDBM; /* select standby mode */
		return -1;
	}

	result = padc->ADCDAT & 0x3FF;

	padc->ADCCON |= ADC_STDBM; /* select standby mode */

	debug ("%s: channel %d, result[DIGIT]=%d\n", __FUNCTION__,
	       (padc->ADCCON >> 3) & 0x7, result);

	/*
	 * Wait for ADC to be ready for next conversion. This delay value was
	 * estimated, because the datasheet does not specify a value.
	 */
	udelay (1000);

	return (result);
}


static void adc_init (void)
{
	S3C2400_ADC *padc;

	padc = S3C2400_GetBase_ADC();

	padc->ADCCON &= ~(0xff << 6); /* clear prescaler bits */
	padc->ADCCON |= ((65 << 6) | ADC_PRSCEN); /* set prescaler */

	/*
	 * Wait some time to avoid problem with very first call of
	 * adc_read(). Without this delay, sometimes the first read
	 * adc value is 0. Perhaps because the adjustment of prescaler
	 * takes some clock cycles?
	 */
	udelay (1000);

	return;
}


static void led_set (unsigned int state)
{
	S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();

	led_init ();

	switch (state) {
	case 0: /* turn LED off */
		gpio->PADAT |= (1 << 12);
		break;
	case 1: /* turn LED on */
		gpio->PADAT &= ~(1 << 12);
		break;
	default:
		break;
	}
}

static void led_blink (void)
{
	led_init ();

	/* blink LED. This function does not return! */
	while (1) {
		reset_timer_masked ();
		led_set (1);
		udelay (1000000 / LED_BLINK_FREQ / 2);
		led_set (0);
		udelay (1000000 / LED_BLINK_FREQ / 2);
	}
}


static void led_init (void)
{
	S3C24X0_GPIO * const gpio = S3C24X0_GetBase_GPIO();

	/* configure GPA12 as output and set to High -> LED off */
	gpio->PACON &= ~(1 << 12);
	gpio->PADAT |= (1 << 12);
}


static void sdelay (unsigned long seconds)
{
	unsigned long i;

	for (i = 0; i < seconds; i++) {
		udelay (1000000);
	}
}


static int global_vars_write_to_eeprom (void)
{
	if (i2c_write_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_STATUS, 1,
				(unsigned char*) &status, 1)) {
		return (1);
	}
	if (i2c_write_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_PASS_CYCLES, 1,
				(unsigned char*) &pass_cycles, 2)) {
		return (1);
	}
	if (i2c_write_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_FIRST_ERROR_CYCLE,
				1, (unsigned char*) &first_error_cycle, 2)) {
		return (1);
	}
	if (i2c_write_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_FIRST_ERROR_NUM,
				1, (unsigned char*) &first_error_num, 1)) {
		return (1);
	}
	if (i2c_write_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_FIRST_ERROR_NAME,
				1, (unsigned char*) first_error_name,
				sizeof(first_error_name))) {
		return (1);
	}
	return (0);
}

static void global_vars_init (void)
{
	status                  = 1; /* error */
	pass_cycles             = 0;
	first_error_cycle       = 0;
	first_error_num         = 0;
	first_error_name[0]     = '\0';
	act_cycle               = 0;
	max_cycles              = 0;
}


static void test_function_table_init (void)
{
	int i;

	for (i = 0; i < BIF_MAX; i++)
		test_function[i].pf = dummy;

	/*
	 * the length of "name" must not exceed 16, including the '\0'
	 * termination. See also the EEPROM address map.
	 */
	test_function[0].pf = test_dip;
	test_function[0].name = "dip";

	test_function[1].pf = test_vcc5v;
	test_function[1].name = "vcc5v";

	test_function[2].pf = test_rotary_switch;
	test_function[2].name = "rotary_switch";

	test_function[3].pf = test_sram;
	test_function[3].name = "sram";

	test_function[4].pf = test_eeprom;
	test_function[4].name = "eeprom";

	test_function[5].pf = test_contact_temp;
	test_function[5].name = "contact_temp";
}


static int read_max_cycles (void)
{
	if (i2c_read_multiple (I2C_EEPROM_DEV_ADDR, EE_ADDR_MAX_CYCLES, 1,
			       (unsigned char *) &max_cycles, 2) != 0) {
		return (1);
	}

	return (0);
}

static int dummy(void)
{
	return (0);
}

int do_temp_log (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
{
	int contact_temp;
	int delay = 0;
#if (CONFIG_COMMANDS & CFG_CMD_DATE) || defined(CONFIG_CMD_DATE)
	struct rtc_time tm;
#endif

	if (argc > 2) {
		printf ("Usage:\n%s\n", cmdtp->usage);
		return 1;
	}

	if (argc > 1) {
		delay = simple_strtoul(argv[1], NULL, 10);
	}

	spi_init ();
	while (1) {

#if (CONFIG_COMMANDS & CFG_CMD_DATE) || defined(CONFIG_CMD_DATE)
		rtc_get (&tm);
		printf ("%4d-%02d-%02d %2d:%02d:%02d - ",
			tm.tm_year, tm.tm_mon, tm.tm_mday,
			tm.tm_hour, tm.tm_min, tm.tm_sec);
#endif

		contact_temp = tsc2000_contact_temp();
		printf ("%d\n", contact_temp) ;

		if (delay != 0)
			/*
			 * reset timer to avoid timestamp overflow problem
			 * after about 68 minutes of udelay() time.
			 */
			reset_timer_masked ();
			sdelay (delay);
	}

	return 0;
}

U_BOOT_CMD(
	tlog,	2,	1,	do_temp_log,
	"tlog    - log contact temperature [1/100 C] to console (endlessly)\n",
	"delay\n"
	"    - contact temperature [1/100 C] is printed endlessly to console\n"
	"      <delay> specifies the seconds to wait between two measurements\n"
	"      For each measurment a timestamp is printeted\n"
);

#endif	/* CFG_CMD_BSP */