summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/ds1306.c
blob: 1ec1837cb4e1e79405d6ba7357d8fc0b51f307f0 (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
/*
 * (C) Copyright 2002 SIXNET, dge@sixnetio.com.
 *
 * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
 * Stephan Linz <linz@li-pro.net>
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * Date & Time support for DS1306 RTC using SPI:
 *
 *    - SXNI855T:    it uses its own soft SPI here in this file
 *    - all other:   use the external spi_xfer() function
 *                   (see include/spi.h)
 */

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

#if defined(CONFIG_CMD_DATE)

#define	RTC_SECONDS		0x00
#define	RTC_MINUTES		0x01
#define	RTC_HOURS		0x02
#define	RTC_DAY_OF_WEEK		0x03
#define	RTC_DATE_OF_MONTH	0x04
#define	RTC_MONTH		0x05
#define	RTC_YEAR		0x06

#define	RTC_SECONDS_ALARM0	0x07
#define	RTC_MINUTES_ALARM0	0x08
#define	RTC_HOURS_ALARM0	0x09
#define	RTC_DAY_OF_WEEK_ALARM0	0x0a

#define	RTC_SECONDS_ALARM1	0x0b
#define	RTC_MINUTES_ALARM1	0x0c
#define	RTC_HOURS_ALARM1	0x0d
#define	RTC_DAY_OF_WEEK_ALARM1	0x0e

#define	RTC_CONTROL		0x0f
#define	RTC_STATUS		0x10
#define	RTC_TRICKLE_CHARGER	0x11

#define	RTC_USER_RAM_BASE	0x20

/* ************************************************************************* */
#ifdef CONFIG_SXNI855T		/* !!! SHOULD BE CHANGED TO NEW CODE !!! */

static void soft_spi_send (unsigned char n);
static unsigned char soft_spi_read (void);
static void init_spi (void);

/*-----------------------------------------------------------------------
 * Definitions
 */

#define	PB_SPISCK	0x00000002	/* PB 30 */
#define PB_SPIMOSI	0x00000004	/* PB 29 */
#define PB_SPIMISO	0x00000008	/* PB 28 */
#define PB_SPI_CE	0x00010000	/* PB 15 */

/* ------------------------------------------------------------------------- */

/* read clock time from DS1306 and return it in *tmp */
int rtc_get (struct rtc_time *tmp)
{
	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
	unsigned char spi_byte;	/* Data Byte */

	init_spi ();		/* set port B for software SPI */

	/* Now we can enable the DS1306 RTC */
	immap->im_cpm.cp_pbdat |= PB_SPI_CE;
	udelay (10);

	/* Shift out the address (0) of the time in the Clock Chip */
	soft_spi_send (0);

	/* Put the clock readings into the rtc_time structure */
	tmp->tm_sec = bcd2bin (soft_spi_read ());	/* Read seconds */
	tmp->tm_min = bcd2bin (soft_spi_read ());	/* Read minutes */

	/* Hours are trickier */
	spi_byte = soft_spi_read ();	/* Read Hours into temporary value */
	if (spi_byte & 0x40) {
		/* 12 hour mode bit is set (time is in 1-12 format) */
		if (spi_byte & 0x20) {
			/* since PM we add 11 to get 0-23 for hours */
			tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
		} else {
			/* since AM we subtract 1 to get 0-23 for hours */
			tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
		}
	} else {
		/* Otherwise, 0-23 hour format */
		tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
	}

	soft_spi_read ();	/* Read and discard Day of week */
	tmp->tm_mday = bcd2bin (soft_spi_read ());	/* Read Day of the Month */
	tmp->tm_mon = bcd2bin (soft_spi_read ());	/* Read Month */

	/* Read Year and convert to this century */
	tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;

	/* Now we can disable the DS1306 RTC */
	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/* Disable DS1306 Chip */
	udelay (10);

	GregorianDay (tmp);	/* Determine the day of week */

	debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

	return 0;
}

/* ------------------------------------------------------------------------- */

/* set clock time in DS1306 RTC and in MPC8xx RTC */
int rtc_set (struct rtc_time *tmp)
{
	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

	init_spi ();		/* set port B for software SPI */

	/* Now we can enable the DS1306 RTC */
	immap->im_cpm.cp_pbdat |= PB_SPI_CE;	/* Enable DS1306 Chip */
	udelay (10);

	/* First disable write protect in the clock chip control register */
	soft_spi_send (0x8F);	/* send address of the control register */
	soft_spi_send (0x00);	/* send control register contents */

	/* Now disable the DS1306 to terminate the write */
	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
	udelay (10);

	/* Now enable the DS1306 to initiate a new write */
	immap->im_cpm.cp_pbdat |= PB_SPI_CE;
	udelay (10);

	/* Next, send the address of the clock time write registers */
	soft_spi_send (0x80);	/* send address of the first time register */

	/* Use Burst Mode to send all of the time data to the clock */
	bin2bcd (tmp->tm_sec);
	soft_spi_send (bin2bcd (tmp->tm_sec));	/* Send Seconds */
	soft_spi_send (bin2bcd (tmp->tm_min));	/* Send Minutes */
	soft_spi_send (bin2bcd (tmp->tm_hour));	/* Send Hour */
	soft_spi_send (bin2bcd (tmp->tm_wday));	/* Send Day of the Week */
	soft_spi_send (bin2bcd (tmp->tm_mday));	/* Send Day of Month */
	soft_spi_send (bin2bcd (tmp->tm_mon));	/* Send Month */
	soft_spi_send (bin2bcd (tmp->tm_year - 2000));	/* Send Year */

	/* Now we can disable the Clock chip to terminate the burst write */
	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/* Disable DS1306 Chip */
	udelay (10);

	/* Now we can enable the Clock chip to initiate a new write */
	immap->im_cpm.cp_pbdat |= PB_SPI_CE;	/* Enable DS1306 Chip */
	udelay (10);

	/* First we Enable write protect in the clock chip control register */
	soft_spi_send (0x8F);	/* send address of the control register */
	soft_spi_send (0x40);	/* send out Control Register contents */

	/* Now disable the DS1306 */
	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/*  Disable DS1306 Chip */
	udelay (10);

	/* Set standard MPC8xx clock to the same time so Linux will
	 * see the time even if it doesn't have a DS1306 clock driver.
	 * This helps with experimenting with standard kernels.
	 */
	{
		ulong tim;

		tim = mktime (tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
			      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

		immap->im_sitk.sitk_rtck = KAPWR_KEY;
		immap->im_sit.sit_rtc = tim;
	}

	debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

	return 0;
}

/* ------------------------------------------------------------------------- */

/* Initialize Port B for software SPI */
static void init_spi (void)
{
	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

	/* Force output pins to begin at logic 0 */
	immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);

	/* Set these 3 signals as outputs */
	immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);

	immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;	/* Make MISO pin an input */
	udelay (10);
}

/* ------------------------------------------------------------------------- */

/* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
static void soft_spi_send (unsigned char n)
{
	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;
	unsigned char bitpos;	/* bit position to receive */
	unsigned char i;	/* Loop Control */

	/* bit position to send, start with most significant bit */
	bitpos = 0x80;

	/* Send 8 bits to software SPI */
	for (i = 0; i < 8; i++) {	/* Loop for 8 bits */
		immap->im_cpm.cp_pbdat |= PB_SPISCK;	/* Raise SCK */

		if (n & bitpos)
			immap->im_cpm.cp_pbdat |= PB_SPIMOSI;	/* Set MOSI to 1 */
		else
			immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;	/* Set MOSI to 0 */
		udelay (10);

		immap->im_cpm.cp_pbdat &= ~PB_SPISCK;	/* Lower SCK */
		udelay (10);

		bitpos >>= 1;	/* Shift for next bit position */
	}
}

/* ------------------------------------------------------------------------- */

/* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
static unsigned char soft_spi_read (void)
{
	volatile immap_t *immap = (immap_t *) CONFIG_SYS_IMMR;

	unsigned char spi_byte = 0;	/* Return value, assume success */
	unsigned char bitpos;	/* bit position to receive */
	unsigned char i;	/* Loop Control */

	/* bit position to receive, start with most significant bit */
	bitpos = 0x80;

	/* Read 8 bits here */
	for (i = 0; i < 8; i++) {	/* Do 8 bits in loop */
		immap->im_cpm.cp_pbdat |= PB_SPISCK;	/* Raise SCK */
		udelay (10);
		if (immap->im_cpm.cp_pbdat & PB_SPIMISO)	/* Get a bit of data */
			spi_byte |= bitpos;	/* Set data accordingly */
		immap->im_cpm.cp_pbdat &= ~PB_SPISCK;	/* Lower SCK */
		udelay (10);
		bitpos >>= 1;	/* Shift for next bit position */
	}

	return spi_byte;	/* Return the byte read */
}

/* ------------------------------------------------------------------------- */

void rtc_reset (void)
{
	return;			/* nothing to do */
}

#else  /* not CONFIG_SXNI855T */
/* ************************************************************************* */

static unsigned char rtc_read (unsigned char reg);
static void rtc_write (unsigned char reg, unsigned char val);

static struct spi_slave *slave;

/* read clock time from DS1306 and return it in *tmp */
int rtc_get (struct rtc_time *tmp)
{
	unsigned char sec, min, hour, mday, wday, mon, year;

	/*
	 * Assuming Vcc = 2.0V (lowest speed)
	 *
	 * REVISIT: If we add an rtc_init() function we can do this
	 * step just once.
	 */
	if (!slave) {
		slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
				SPI_MODE_3 | SPI_CS_HIGH);
		if (!slave)
			return;
	}

	if (spi_claim_bus(slave))
		return;

	sec = rtc_read (RTC_SECONDS);
	min = rtc_read (RTC_MINUTES);
	hour = rtc_read (RTC_HOURS);
	mday = rtc_read (RTC_DATE_OF_MONTH);
	wday = rtc_read (RTC_DAY_OF_WEEK);
	mon = rtc_read (RTC_MONTH);
	year = rtc_read (RTC_YEAR);

	spi_release_bus(slave);

	debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
	       "hr: %02x min: %02x sec: %02x\n",
	       year, mon, mday, wday, hour, min, sec);
	debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
	       rtc_read (RTC_DAY_OF_WEEK_ALARM0),
	       rtc_read (RTC_HOURS_ALARM0),
	       rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
	debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
	       rtc_read (RTC_DAY_OF_WEEK_ALARM1),
	       rtc_read (RTC_HOURS_ALARM1),
	       rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));

	tmp->tm_sec = bcd2bin (sec & 0x7F);	/* convert Seconds */
	tmp->tm_min = bcd2bin (min & 0x7F);	/* convert Minutes */

	/* convert Hours */
	tmp->tm_hour = (hour & 0x40)
		? ((hour & 0x20)	/* 12 hour mode */
		   ? bcd2bin (hour & 0x1F) + 11	/* PM */
		   : bcd2bin (hour & 0x1F) - 1	/* AM */
		)
		: bcd2bin (hour & 0x3F);	/* 24 hour mode */

	tmp->tm_mday = bcd2bin (mday & 0x3F);	/* convert Day of the Month */
	tmp->tm_mon = bcd2bin (mon & 0x1F);	/* convert Month */
	tmp->tm_year = bcd2bin (year) + 2000;	/* convert Year */
	tmp->tm_wday = bcd2bin (wday & 0x07) - 1;	/* convert Day of the Week */
	tmp->tm_yday = 0;
	tmp->tm_isdst = 0;

	debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

	return 0;
}

/* ------------------------------------------------------------------------- */

/* set clock time from *tmp in DS1306 RTC */
int rtc_set (struct rtc_time *tmp)
{
	/* Assuming Vcc = 2.0V (lowest speed) */
	if (!slave) {
		slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
				SPI_MODE_3 | SPI_CS_HIGH);
		if (!slave)
			return;
	}

	if (spi_claim_bus(slave))
		return;

	debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

	rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
	rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
	rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
	rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
	rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
	rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
	rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));

	spi_release_bus(slave);
}

/* ------------------------------------------------------------------------- */

/* reset the DS1306 */
void rtc_reset (void)
{
	/* Assuming Vcc = 2.0V (lowest speed) */
	if (!slave) {
		slave = spi_setup_slave(0, CONFIG_SYS_SPI_RTC_DEVID, 600000,
				SPI_MODE_3 | SPI_CS_HIGH);
		if (!slave)
			return;
	}

	if (spi_claim_bus(slave))
		return;

	/* clear the control register */
	rtc_write (RTC_CONTROL, 0x00);	/* 1st step: reset WP */
	rtc_write (RTC_CONTROL, 0x00);	/* 2nd step: reset 1Hz, AIE1, AIE0 */

	/* reset all alarms */
	rtc_write (RTC_SECONDS_ALARM0, 0x00);
	rtc_write (RTC_SECONDS_ALARM1, 0x00);
	rtc_write (RTC_MINUTES_ALARM0, 0x00);
	rtc_write (RTC_MINUTES_ALARM1, 0x00);
	rtc_write (RTC_HOURS_ALARM0, 0x00);
	rtc_write (RTC_HOURS_ALARM1, 0x00);
	rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
	rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);

	spi_release_bus(slave);
}

/* ------------------------------------------------------------------------- */

static unsigned char rtc_read (unsigned char reg)
{
	int ret;

	ret = spi_w8r8(slave, reg);
	return ret < 0 ? 0 : ret;
}

/* ------------------------------------------------------------------------- */

static void rtc_write (unsigned char reg, unsigned char val)
{
	unsigned char dout[2];	/* SPI Output Data Bytes */
	unsigned char din[2];	/* SPI Input Data Bytes */

	dout[0] = 0x80 | reg;
	dout[1] = val;

	spi_xfer (slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
}

#endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */

#endif
OpenPOWER on IntegriCloud