xref: /openbmc/u-boot/drivers/rtc/ds1306.c (revision 61fb15c5)
1 /*
2  * (C) Copyright 2002 SIXNET, dge@sixnetio.com.
3  *
4  * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
5  * Stephan Linz <linz@li-pro.net>
6  *
7  * See file CREDITS for list of people who contributed to this
8  * project.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of
13  * the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23  * MA 02111-1307 USA
24  */
25 
26 /*
27  * Date & Time support for DS1306 RTC using SPI:
28  *
29  *    - SXNI855T:    it uses its own soft SPI here in this file
30  *    - all other:   use the external spi_xfer() function
31  *                   (see include/spi.h)
32  */
33 
34 #include <common.h>
35 #include <command.h>
36 #include <rtc.h>
37 #include <spi.h>
38 
39 #if defined(CONFIG_RTC_DS1306) && defined(CONFIG_CMD_DATE)
40 
41 #define	RTC_SECONDS		0x00
42 #define	RTC_MINUTES		0x01
43 #define	RTC_HOURS		0x02
44 #define	RTC_DAY_OF_WEEK		0x03
45 #define	RTC_DATE_OF_MONTH	0x04
46 #define	RTC_MONTH		0x05
47 #define	RTC_YEAR		0x06
48 
49 #define	RTC_SECONDS_ALARM0	0x07
50 #define	RTC_MINUTES_ALARM0	0x08
51 #define	RTC_HOURS_ALARM0	0x09
52 #define	RTC_DAY_OF_WEEK_ALARM0	0x0a
53 
54 #define	RTC_SECONDS_ALARM1	0x0b
55 #define	RTC_MINUTES_ALARM1	0x0c
56 #define	RTC_HOURS_ALARM1	0x0d
57 #define	RTC_DAY_OF_WEEK_ALARM1	0x0e
58 
59 #define	RTC_CONTROL		0x0f
60 #define	RTC_STATUS		0x10
61 #define	RTC_TRICKLE_CHARGER	0x11
62 
63 #define	RTC_USER_RAM_BASE	0x20
64 
65 /*
66  * External table of chip select functions (see the appropriate board
67  * support for the actual definition of the table).
68  */
69 extern spi_chipsel_type spi_chipsel[];
70 extern int spi_chipsel_cnt;
71 
72 static unsigned int bin2bcd (unsigned int n);
73 static unsigned char bcd2bin (unsigned char c);
74 
75 /* ************************************************************************* */
76 #ifdef CONFIG_SXNI855T		/* !!! SHOULD BE CHANGED TO NEW CODE !!! */
77 
78 static void soft_spi_send (unsigned char n);
79 static unsigned char soft_spi_read (void);
80 static void init_spi (void);
81 
82 /*-----------------------------------------------------------------------
83  * Definitions
84  */
85 
86 #define	PB_SPISCK	0x00000002	/* PB 30 */
87 #define PB_SPIMOSI	0x00000004	/* PB 29 */
88 #define PB_SPIMISO	0x00000008	/* PB 28 */
89 #define PB_SPI_CE	0x00010000	/* PB 15 */
90 
91 /* ------------------------------------------------------------------------- */
92 
93 /* read clock time from DS1306 and return it in *tmp */
94 void rtc_get (struct rtc_time *tmp)
95 {
96 	volatile immap_t *immap = (immap_t *) CFG_IMMR;
97 	unsigned char spi_byte;	/* Data Byte */
98 
99 	init_spi ();		/* set port B for software SPI */
100 
101 	/* Now we can enable the DS1306 RTC */
102 	immap->im_cpm.cp_pbdat |= PB_SPI_CE;
103 	udelay (10);
104 
105 	/* Shift out the address (0) of the time in the Clock Chip */
106 	soft_spi_send (0);
107 
108 	/* Put the clock readings into the rtc_time structure */
109 	tmp->tm_sec = bcd2bin (soft_spi_read ());	/* Read seconds */
110 	tmp->tm_min = bcd2bin (soft_spi_read ());	/* Read minutes */
111 
112 	/* Hours are trickier */
113 	spi_byte = soft_spi_read ();	/* Read Hours into temporary value */
114 	if (spi_byte & 0x40) {
115 		/* 12 hour mode bit is set (time is in 1-12 format) */
116 		if (spi_byte & 0x20) {
117 			/* since PM we add 11 to get 0-23 for hours */
118 			tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) + 11;
119 		} else {
120 			/* since AM we subtract 1 to get 0-23 for hours */
121 			tmp->tm_hour = (bcd2bin (spi_byte & 0x1F)) - 1;
122 		}
123 	} else {
124 		/* Otherwise, 0-23 hour format */
125 		tmp->tm_hour = (bcd2bin (spi_byte & 0x3F));
126 	}
127 
128 	soft_spi_read ();	/* Read and discard Day of week */
129 	tmp->tm_mday = bcd2bin (soft_spi_read ());	/* Read Day of the Month */
130 	tmp->tm_mon = bcd2bin (soft_spi_read ());	/* Read Month */
131 
132 	/* Read Year and convert to this century */
133 	tmp->tm_year = bcd2bin (soft_spi_read ()) + 2000;
134 
135 	/* Now we can disable the DS1306 RTC */
136 	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/* Disable DS1306 Chip */
137 	udelay (10);
138 
139 	GregorianDay (tmp);	/* Determine the day of week */
140 
141 	debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
142 	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
143 	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
144 }
145 
146 /* ------------------------------------------------------------------------- */
147 
148 /* set clock time in DS1306 RTC and in MPC8xx RTC */
149 void rtc_set (struct rtc_time *tmp)
150 {
151 	volatile immap_t *immap = (immap_t *) CFG_IMMR;
152 
153 	init_spi ();		/* set port B for software SPI */
154 
155 	/* Now we can enable the DS1306 RTC */
156 	immap->im_cpm.cp_pbdat |= PB_SPI_CE;	/* Enable DS1306 Chip */
157 	udelay (10);
158 
159 	/* First disable write protect in the clock chip control register */
160 	soft_spi_send (0x8F);	/* send address of the control register */
161 	soft_spi_send (0x00);	/* send control register contents */
162 
163 	/* Now disable the DS1306 to terminate the write */
164 	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;
165 	udelay (10);
166 
167 	/* Now enable the DS1306 to initiate a new write */
168 	immap->im_cpm.cp_pbdat |= PB_SPI_CE;
169 	udelay (10);
170 
171 	/* Next, send the address of the clock time write registers */
172 	soft_spi_send (0x80);	/* send address of the first time register */
173 
174 	/* Use Burst Mode to send all of the time data to the clock */
175 	bin2bcd (tmp->tm_sec);
176 	soft_spi_send (bin2bcd (tmp->tm_sec));	/* Send Seconds */
177 	soft_spi_send (bin2bcd (tmp->tm_min));	/* Send Minutes */
178 	soft_spi_send (bin2bcd (tmp->tm_hour));	/* Send Hour */
179 	soft_spi_send (bin2bcd (tmp->tm_wday));	/* Send Day of the Week */
180 	soft_spi_send (bin2bcd (tmp->tm_mday));	/* Send Day of Month */
181 	soft_spi_send (bin2bcd (tmp->tm_mon));	/* Send Month */
182 	soft_spi_send (bin2bcd (tmp->tm_year - 2000));	/* Send Year */
183 
184 	/* Now we can disable the Clock chip to terminate the burst write */
185 	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/* Disable DS1306 Chip */
186 	udelay (10);
187 
188 	/* Now we can enable the Clock chip to initiate a new write */
189 	immap->im_cpm.cp_pbdat |= PB_SPI_CE;	/* Enable DS1306 Chip */
190 	udelay (10);
191 
192 	/* First we Enable write protect in the clock chip control register */
193 	soft_spi_send (0x8F);	/* send address of the control register */
194 	soft_spi_send (0x40);	/* send out Control Register contents */
195 
196 	/* Now disable the DS1306 */
197 	immap->im_cpm.cp_pbdat &= ~PB_SPI_CE;	/*  Disable DS1306 Chip */
198 	udelay (10);
199 
200 	/* Set standard MPC8xx clock to the same time so Linux will
201 	 * see the time even if it doesn't have a DS1306 clock driver.
202 	 * This helps with experimenting with standard kernels.
203 	 */
204 	{
205 		ulong tim;
206 
207 		tim = mktime (tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
208 			      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
209 
210 		immap->im_sitk.sitk_rtck = KAPWR_KEY;
211 		immap->im_sit.sit_rtc = tim;
212 	}
213 
214 	debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
215 	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
216 	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
217 }
218 
219 /* ------------------------------------------------------------------------- */
220 
221 /* Initialize Port B for software SPI */
222 static void init_spi (void)
223 {
224 	volatile immap_t *immap = (immap_t *) CFG_IMMR;
225 
226 	/* Force output pins to begin at logic 0 */
227 	immap->im_cpm.cp_pbdat &= ~(PB_SPI_CE | PB_SPIMOSI | PB_SPISCK);
228 
229 	/* Set these 3 signals as outputs */
230 	immap->im_cpm.cp_pbdir |= (PB_SPIMOSI | PB_SPI_CE | PB_SPISCK);
231 
232 	immap->im_cpm.cp_pbdir &= ~PB_SPIMISO;	/* Make MISO pin an input */
233 	udelay (10);
234 }
235 
236 /* ------------------------------------------------------------------------- */
237 
238 /* NOTE: soft_spi_send() assumes that the I/O lines are configured already */
239 static void soft_spi_send (unsigned char n)
240 {
241 	volatile immap_t *immap = (immap_t *) CFG_IMMR;
242 	unsigned char bitpos;	/* bit position to receive */
243 	unsigned char i;	/* Loop Control */
244 
245 	/* bit position to send, start with most significant bit */
246 	bitpos = 0x80;
247 
248 	/* Send 8 bits to software SPI */
249 	for (i = 0; i < 8; i++) {	/* Loop for 8 bits */
250 		immap->im_cpm.cp_pbdat |= PB_SPISCK;	/* Raise SCK */
251 
252 		if (n & bitpos)
253 			immap->im_cpm.cp_pbdat |= PB_SPIMOSI;	/* Set MOSI to 1 */
254 		else
255 			immap->im_cpm.cp_pbdat &= ~PB_SPIMOSI;	/* Set MOSI to 0 */
256 		udelay (10);
257 
258 		immap->im_cpm.cp_pbdat &= ~PB_SPISCK;	/* Lower SCK */
259 		udelay (10);
260 
261 		bitpos >>= 1;	/* Shift for next bit position */
262 	}
263 }
264 
265 /* ------------------------------------------------------------------------- */
266 
267 /* NOTE: soft_spi_read() assumes that the I/O lines are configured already */
268 static unsigned char soft_spi_read (void)
269 {
270 	volatile immap_t *immap = (immap_t *) CFG_IMMR;
271 
272 	unsigned char spi_byte = 0;	/* Return value, assume success */
273 	unsigned char bitpos;	/* bit position to receive */
274 	unsigned char i;	/* Loop Control */
275 
276 	/* bit position to receive, start with most significant bit */
277 	bitpos = 0x80;
278 
279 	/* Read 8 bits here */
280 	for (i = 0; i < 8; i++) {	/* Do 8 bits in loop */
281 		immap->im_cpm.cp_pbdat |= PB_SPISCK;	/* Raise SCK */
282 		udelay (10);
283 		if (immap->im_cpm.cp_pbdat & PB_SPIMISO)	/* Get a bit of data */
284 			spi_byte |= bitpos;	/* Set data accordingly */
285 		immap->im_cpm.cp_pbdat &= ~PB_SPISCK;	/* Lower SCK */
286 		udelay (10);
287 		bitpos >>= 1;	/* Shift for next bit position */
288 	}
289 
290 	return spi_byte;	/* Return the byte read */
291 }
292 
293 /* ------------------------------------------------------------------------- */
294 
295 void rtc_reset (void)
296 {
297 	return;			/* nothing to do */
298 }
299 
300 #else  /* not CONFIG_SXNI855T */
301 /* ************************************************************************* */
302 
303 static unsigned char rtc_read (unsigned char reg);
304 static void rtc_write (unsigned char reg, unsigned char val);
305 
306 /* read clock time from DS1306 and return it in *tmp */
307 void rtc_get (struct rtc_time *tmp)
308 {
309 	unsigned char sec, min, hour, mday, wday, mon, year;
310 
311 	sec = rtc_read (RTC_SECONDS);
312 	min = rtc_read (RTC_MINUTES);
313 	hour = rtc_read (RTC_HOURS);
314 	mday = rtc_read (RTC_DATE_OF_MONTH);
315 	wday = rtc_read (RTC_DAY_OF_WEEK);
316 	mon = rtc_read (RTC_MONTH);
317 	year = rtc_read (RTC_YEAR);
318 
319 	debug ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
320 	       "hr: %02x min: %02x sec: %02x\n",
321 	       year, mon, mday, wday, hour, min, sec);
322 	debug ("Alarms[0]: wday: %02x hour: %02x min: %02x sec: %02x\n",
323 	       rtc_read (RTC_DAY_OF_WEEK_ALARM0),
324 	       rtc_read (RTC_HOURS_ALARM0),
325 	       rtc_read (RTC_MINUTES_ALARM0), rtc_read (RTC_SECONDS_ALARM0));
326 	debug ("Alarms[1]: wday: %02x hour: %02x min: %02x sec: %02x\n",
327 	       rtc_read (RTC_DAY_OF_WEEK_ALARM1),
328 	       rtc_read (RTC_HOURS_ALARM1),
329 	       rtc_read (RTC_MINUTES_ALARM1), rtc_read (RTC_SECONDS_ALARM1));
330 
331 	tmp->tm_sec = bcd2bin (sec & 0x7F);	/* convert Seconds */
332 	tmp->tm_min = bcd2bin (min & 0x7F);	/* convert Minutes */
333 
334 	/* convert Hours */
335 	tmp->tm_hour = (hour & 0x40)
336 		? ((hour & 0x20)	/* 12 hour mode */
337 		   ? bcd2bin (hour & 0x1F) + 11	/* PM */
338 		   : bcd2bin (hour & 0x1F) - 1	/* AM */
339 		)
340 		: bcd2bin (hour & 0x3F);	/* 24 hour mode */
341 
342 	tmp->tm_mday = bcd2bin (mday & 0x3F);	/* convert Day of the Month */
343 	tmp->tm_mon = bcd2bin (mon & 0x1F);	/* convert Month */
344 	tmp->tm_year = bcd2bin (year) + 2000;	/* convert Year */
345 	tmp->tm_wday = bcd2bin (wday & 0x07) - 1;	/* convert Day of the Week */
346 	tmp->tm_yday = 0;
347 	tmp->tm_isdst = 0;
348 
349 	debug ("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
350 	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
351 	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
352 }
353 
354 /* ------------------------------------------------------------------------- */
355 
356 /* set clock time from *tmp in DS1306 RTC */
357 void rtc_set (struct rtc_time *tmp)
358 {
359 	debug ("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
360 	       tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
361 	       tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
362 
363 	rtc_write (RTC_SECONDS, bin2bcd (tmp->tm_sec));
364 	rtc_write (RTC_MINUTES, bin2bcd (tmp->tm_min));
365 	rtc_write (RTC_HOURS, bin2bcd (tmp->tm_hour));
366 	rtc_write (RTC_DAY_OF_WEEK, bin2bcd (tmp->tm_wday + 1));
367 	rtc_write (RTC_DATE_OF_MONTH, bin2bcd (tmp->tm_mday));
368 	rtc_write (RTC_MONTH, bin2bcd (tmp->tm_mon));
369 	rtc_write (RTC_YEAR, bin2bcd (tmp->tm_year - 2000));
370 }
371 
372 /* ------------------------------------------------------------------------- */
373 
374 /* reset the DS1306 */
375 void rtc_reset (void)
376 {
377 	/* clear the control register */
378 	rtc_write (RTC_CONTROL, 0x00);	/* 1st step: reset WP */
379 	rtc_write (RTC_CONTROL, 0x00);	/* 2nd step: reset 1Hz, AIE1, AIE0 */
380 
381 	/* reset all alarms */
382 	rtc_write (RTC_SECONDS_ALARM0, 0x00);
383 	rtc_write (RTC_SECONDS_ALARM1, 0x00);
384 	rtc_write (RTC_MINUTES_ALARM0, 0x00);
385 	rtc_write (RTC_MINUTES_ALARM1, 0x00);
386 	rtc_write (RTC_HOURS_ALARM0, 0x00);
387 	rtc_write (RTC_HOURS_ALARM1, 0x00);
388 	rtc_write (RTC_DAY_OF_WEEK_ALARM0, 0x00);
389 	rtc_write (RTC_DAY_OF_WEEK_ALARM1, 0x00);
390 }
391 
392 /* ------------------------------------------------------------------------- */
393 
394 static unsigned char rtc_read (unsigned char reg)
395 {
396 	unsigned char dout[2];	/* SPI Output Data Bytes */
397 	unsigned char din[2];	/* SPI Input Data Bytes */
398 
399 	dout[0] = reg;
400 
401 	if (spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din) != 0) {
402 		return 0;
403 	} else {
404 		return din[1];
405 	}
406 }
407 
408 /* ------------------------------------------------------------------------- */
409 
410 static void rtc_write (unsigned char reg, unsigned char val)
411 {
412 	unsigned char dout[2];	/* SPI Output Data Bytes */
413 	unsigned char din[2];	/* SPI Input Data Bytes */
414 
415 	dout[0] = 0x80 | reg;
416 	dout[1] = val;
417 
418 	spi_xfer (spi_chipsel[CFG_SPI_RTC_DEVID], 16, dout, din);
419 }
420 
421 #endif /* end of code exclusion (see #ifdef CONFIG_SXNI855T above) */
422 
423 /* ------------------------------------------------------------------------- */
424 
425 static unsigned char bcd2bin (unsigned char n)
426 {
427 	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
428 }
429 
430 /* ------------------------------------------------------------------------- */
431 
432 static unsigned int bin2bcd (unsigned int n)
433 {
434 	return (((n / 10) << 4) | (n % 10));
435 }
436 /* ------------------------------------------------------------------------- */
437 
438 #endif
439