summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rs5c372.c
blob: 65f45ea5e3c3af9b542a8ee4b95f9398337fb234 (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
/*
 * rs5c372.c
 *
 * Device driver for Ricoh's Real Time Controller RS5C372A.
 *
 * Copyright (C) 2004 Gary Jennejohn garyj@denx.de
 *
 * Based in part in ds1307.c -
 * (C) Copyright 2001, 2002, 2003
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 * Keith Outwater, keith_outwater@mvis.com`
 * Steven Scholz, steven.scholz@imc-berlin.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.
 */

#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>

#if defined(CONFIG_CMD_DATE)
/*
 * Reads are always done starting with register 15, which requires some
 * jumping-through-hoops to access the data correctly.
 *
 * Writes are always done starting with register 0.
 */

#define DEBUG 0

#if DEBUG
static unsigned int rtc_debug = DEBUG;
#else
#define rtc_debug 0	/* gcc will remove all the debug code for us */
#endif

#ifndef CONFIG_SYS_I2C_RTC_ADDR
#define CONFIG_SYS_I2C_RTC_ADDR 0x32
#endif

#define RS5C372_RAM_SIZE 0x10
#define RATE_32000HZ	0x80	/* Rate Select 32.000KHz */
#define RATE_32768HZ	0x00	/* Rate Select 32.768KHz */

#define STATUS_XPT  0x10    /* data invalid because voltage was 0 */

#define USE_24HOUR_MODE 0x20
#define TWELVE_HOUR_MODE(n) ((((n) >> 5) & 1) == 0)
#define HOURS_AP(n)	(((n) >> 5) & 1)
#define HOURS_12(n)	bcd2bin((n) & 0x1F)
#define HOURS_24(n)	bcd2bin((n) & 0x3F)


static int setup_done = 0;

static int
rs5c372_readram(unsigned char *buf, int len)
{
	int ret;

	ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, len);
	if (ret != 0) {
		printf("%s: failed to read\n", __FUNCTION__);
		return ret;
	}

	if (buf[0] & STATUS_XPT)
		printf("### Warning: RTC lost power\n");

	return ret;
}

static void
rs5c372_enable(void)
{
	unsigned char buf[RS5C372_RAM_SIZE + 1];
	int ret;

	/* note that this returns reg. 15 in buf[1] */
	ret = rs5c372_readram(&buf[1], RS5C372_RAM_SIZE);
	if (ret != 0) {
		printf("%s: failed\n", __FUNCTION__);
		return;
	}

	buf[0] = 0;
	/* we want to start writing at register 0 so we have to copy the */
	/* register contents up one slot */
	for (ret = 2; ret < 9; ret++)
		buf[ret - 1] = buf[ret];
	/* registers 0 to 6 (time values) are not touched */
	buf[8] = RATE_32768HZ; /* reg. 7 */
	buf[9] = 0; /* reg. 8 */
	buf[10] = 0; /* reg. 9 */
	buf[11] = 0; /* reg. 10 */
	buf[12] = 0; /* reg. 11 */
	buf[13] = 0; /* reg. 12 */
	buf[14] = 0; /* reg. 13 */
	buf[15] = 0; /* reg. 14 */
	buf[16] = USE_24HOUR_MODE; /* reg. 15 */
	ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, RS5C372_RAM_SIZE+1);
	if (ret != 0) {
		printf("%s: failed\n", __FUNCTION__);
		return;
	}
	setup_done = 1;

	return;
}

static void
rs5c372_convert_to_time(struct rtc_time *dt, unsigned char *buf)
{
	/* buf[0] is register 15 */
	dt->tm_sec = bcd2bin(buf[1]);
	dt->tm_min = bcd2bin(buf[2]);

	if (TWELVE_HOUR_MODE(buf[0])) {
		dt->tm_hour = HOURS_12(buf[3]);
		if (HOURS_AP(buf[3])) /* PM */
			dt->tm_hour += 12;
	} else /* 24-hour-mode */
		dt->tm_hour = HOURS_24(buf[3]);

	dt->tm_mday = bcd2bin(buf[5]);
	dt->tm_mon = bcd2bin(buf[6]);
	dt->tm_year = bcd2bin(buf[7]);
	if (dt->tm_year >= 70)
		dt->tm_year += 1900;
	else
		dt->tm_year += 2000;
	/* 0 is Sunday */
	dt->tm_wday = bcd2bin(buf[4] & 0x07);
	dt->tm_yday = 0;
	dt->tm_isdst= 0;

	if(rtc_debug > 2) {
		printf("rs5c372_convert_to_time: year = %d\n", dt->tm_year);
		printf("rs5c372_convert_to_time: mon  = %d\n", dt->tm_mon);
		printf("rs5c372_convert_to_time: mday = %d\n", dt->tm_mday);
		printf("rs5c372_convert_to_time: hour = %d\n", dt->tm_hour);
		printf("rs5c372_convert_to_time: min  = %d\n", dt->tm_min);
		printf("rs5c372_convert_to_time: sec  = %d\n", dt->tm_sec);
	}
}

/*
 * Get the current time from the RTC
 */
int
rtc_get (struct rtc_time *tmp)
{
	unsigned char buf[RS5C372_RAM_SIZE];
	int ret;

	if (!setup_done)
		rs5c372_enable();

	if (!setup_done)
		return -1;

	memset(buf, 0, sizeof(buf));

	/* note that this returns reg. 15 in buf[0] */
	ret = rs5c372_readram(buf, RS5C372_RAM_SIZE);
	if (ret != 0) {
		printf("%s: failed\n", __FUNCTION__);
		return -1;
	}

	rs5c372_convert_to_time(tmp, buf);

	return 0;
}

/*
 * Set the RTC
 */
int rtc_set (struct rtc_time *tmp)
{
	unsigned char buf[8], reg15;
	int ret;

	if (!setup_done)
		rs5c372_enable();

	if (!setup_done)
		return -1;

	if(rtc_debug > 2) {
		printf("rtc_set: tm_year = %d\n", tmp->tm_year);
		printf("rtc_set: tm_mon	 = %d\n", tmp->tm_mon);
		printf("rtc_set: tm_mday = %d\n", tmp->tm_mday);
		printf("rtc_set: tm_hour = %d\n", tmp->tm_hour);
		printf("rtc_set: tm_min	 = %d\n", tmp->tm_min);
		printf("rtc_set: tm_sec	 = %d\n", tmp->tm_sec);
	}

	memset(buf, 0, sizeof(buf));

	/* only read register 15 */
	ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 1);

	if (ret == 0) {
		/* need to save register 15 */
		reg15 = buf[0];
		buf[0] = 0;	/* register address on RS5C372 */
		buf[1] = bin2bcd(tmp->tm_sec);
		buf[2] = bin2bcd(tmp->tm_min);
		/* need to handle 12 hour mode */
		if (TWELVE_HOUR_MODE(reg15)) {
			if (tmp->tm_hour >= 12) { /* PM */
				/* 12 PM is a special case */
				if (tmp->tm_hour == 12)
					buf[3] = bin2bcd(tmp->tm_hour);
				else
					buf[3] = bin2bcd(tmp->tm_hour - 12);
				buf[3] |= 0x20;
			}
		} else {
			buf[3] = bin2bcd(tmp->tm_hour);
		}

		buf[4] = bin2bcd(tmp->tm_wday);
		buf[5] = bin2bcd(tmp->tm_mday);
		buf[6] = bin2bcd(tmp->tm_mon);
		if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
			printf("WARNING: year should be between 1970 and 2069!\n");
		buf[7] = bin2bcd(tmp->tm_year % 100);

		ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 8);
		if (ret != 0) {
			printf("rs5c372_set_datetime(), i2c_master_send() returned %d\n",ret);
			return -1;
		}
	} else {
		return -1;
	}

	return 0;
}

/*
 * Reset the RTC. We set the date back to 1970-01-01.
 */
void
rtc_reset (void)
{
	struct rtc_time tmp;

	if (!setup_done)
		rs5c372_enable();

	if (!setup_done)
		return;

	tmp.tm_year = 1970;
	tmp.tm_mon = 1;
	/* Jan. 1, 1970 was a Thursday */
	tmp.tm_wday= 4;
	tmp.tm_mday= 1;
	tmp.tm_hour = 0;
	tmp.tm_min = 0;
	tmp.tm_sec = 0;

	rtc_set(&tmp);

	printf ("RTC:	%4d-%02d-%02d %2d:%02d:%02d UTC\n",
		tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
		tmp.tm_hour, tmp.tm_min, tmp.tm_sec);

	return;
}

#endif
OpenPOWER on IntegriCloud