aboutsummaryrefslogtreecommitdiff
path: root/drivers/rtc/m41t62.c
blob: 3829bc54eb8c0c08777e59a7d523c658fb9a8f97 (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
/*
 * (C) Copyright 2008
 * Stefan Roese, DENX Software Engineering, sr@denx.de.
 *
 * based on a the Linux rtc-m41t80.c driver which is:
 *   Alexander Bigga <ab@mycable.de>, 2006 (c) mycable GmbH
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * Date & Time support for STMicroelectronics M41T62
 */

/* #define	DEBUG	*/

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

#if defined(CONFIG_CMD_DATE)

#define M41T62_REG_SSEC	0
#define M41T62_REG_SEC	1
#define M41T62_REG_MIN	2
#define M41T62_REG_HOUR	3
#define M41T62_REG_WDAY	4
#define M41T62_REG_DAY	5
#define M41T62_REG_MON	6
#define M41T62_REG_YEAR	7
#define M41T62_REG_ALARM_MON	0xa
#define M41T62_REG_ALARM_DAY	0xb
#define M41T62_REG_ALARM_HOUR	0xc
#define M41T62_REG_ALARM_MIN	0xd
#define M41T62_REG_ALARM_SEC	0xe
#define M41T62_REG_FLAGS	0xf

#define M41T62_DATETIME_REG_SIZE	(M41T62_REG_YEAR + 1)
#define M41T62_ALARM_REG_SIZE	\
	(M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON)

#define M41T62_SEC_ST		(1 << 7)	/* ST: Stop Bit */
#define M41T62_ALMON_AFE	(1 << 7)	/* AFE: AF Enable Bit */
#define M41T62_ALMON_SQWE	(1 << 6)	/* SQWE: SQW Enable Bit */
#define M41T62_ALHOUR_HT	(1 << 6)	/* HT: Halt Update Bit */
#define M41T62_FLAGS_AF		(1 << 6)	/* AF: Alarm Flag Bit */
#define M41T62_FLAGS_BATT_LOW	(1 << 4)	/* BL: Battery Low Bit */

#define M41T62_FEATURE_HT	(1 << 0)
#define M41T62_FEATURE_BL	(1 << 1)

#define M41T80_ALHOUR_HT	(1 << 6)	/* HT: Halt Update Bit */

int rtc_get(struct rtc_time *tm)
{
	u8 buf[M41T62_DATETIME_REG_SIZE];

	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);

	debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
	      "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
	      __FUNCTION__,
	      buf[0], buf[1], buf[2], buf[3],
	      buf[4], buf[5], buf[6], buf[7]);

	tm->tm_sec = bcd2bin(buf[M41T62_REG_SEC] & 0x7f);
	tm->tm_min = bcd2bin(buf[M41T62_REG_MIN] & 0x7f);
	tm->tm_hour = bcd2bin(buf[M41T62_REG_HOUR] & 0x3f);
	tm->tm_mday = bcd2bin(buf[M41T62_REG_DAY] & 0x3f);
	tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07;
	tm->tm_mon = bcd2bin(buf[M41T62_REG_MON] & 0x1f);

	/* assume 20YY not 19YY, and ignore the Century Bit */
	/* U-Boot needs to add 1900 here */
	tm->tm_year = bcd2bin(buf[M41T62_REG_YEAR]) + 100 + 1900;

	debug("%s: tm is secs=%d, mins=%d, hours=%d, "
	      "mday=%d, mon=%d, year=%d, wday=%d\n",
	      __FUNCTION__,
	      tm->tm_sec, tm->tm_min, tm->tm_hour,
	      tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	return 0;
}

int rtc_set(struct rtc_time *tm)
{
	u8 buf[M41T62_DATETIME_REG_SIZE];

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

	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);

	/* Merge time-data and register flags into buf[0..7] */
	buf[M41T62_REG_SSEC] = 0;
	buf[M41T62_REG_SEC] =
		bin2bcd(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f);
	buf[M41T62_REG_MIN] =
		bin2bcd(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f);
	buf[M41T62_REG_HOUR] =
		bin2bcd(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ;
	buf[M41T62_REG_WDAY] =
		(tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07);
	buf[M41T62_REG_DAY] =
		bin2bcd(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f);
	buf[M41T62_REG_MON] =
		bin2bcd(tm->tm_mon) | (buf[M41T62_REG_MON] & ~0x1f);
	/* assume 20YY not 19YY */
	buf[M41T62_REG_YEAR] = bin2bcd(tm->tm_year % 100);

	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) {
		printf("I2C write failed in %s()\n", __func__);
		return -1;
	}

	return 0;
}

void rtc_reset(void)
{
	u8 val;

	/*
	 * M41T82: Make sure HT (Halt Update) bit is cleared.
	 * This bit is 0 in M41T62 so its save to clear it always.
	 */
	i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
	val &= ~M41T80_ALHOUR_HT;
	i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
}

#endif