1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2008
4 * Stefan Roese, DENX Software Engineering, sr@denx.de.
5 *
6 * based on a the Linux rtc-m41t80.c driver which is:
7 * Alexander Bigga <ab@mycable.de>, 2006 (c) mycable GmbH
8 */
9
10 /*
11 * Date & Time support for STMicroelectronics M41T62
12 */
13
14 /* #define DEBUG */
15
16 #include <common.h>
17 #include <command.h>
18 #include <rtc.h>
19 #include <i2c.h>
20
21 #if defined(CONFIG_CMD_DATE)
22
23 #define M41T62_REG_SSEC 0
24 #define M41T62_REG_SEC 1
25 #define M41T62_REG_MIN 2
26 #define M41T62_REG_HOUR 3
27 #define M41T62_REG_WDAY 4
28 #define M41T62_REG_DAY 5
29 #define M41T62_REG_MON 6
30 #define M41T62_REG_YEAR 7
31 #define M41T62_REG_ALARM_MON 0xa
32 #define M41T62_REG_ALARM_DAY 0xb
33 #define M41T62_REG_ALARM_HOUR 0xc
34 #define M41T62_REG_ALARM_MIN 0xd
35 #define M41T62_REG_ALARM_SEC 0xe
36 #define M41T62_REG_FLAGS 0xf
37
38 #define M41T62_DATETIME_REG_SIZE (M41T62_REG_YEAR + 1)
39 #define M41T62_ALARM_REG_SIZE \
40 (M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON)
41
42 #define M41T62_SEC_ST (1 << 7) /* ST: Stop Bit */
43 #define M41T62_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */
44 #define M41T62_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */
45 #define M41T62_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
46 #define M41T62_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */
47 #define M41T62_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */
48
49 #define M41T62_FEATURE_HT (1 << 0)
50 #define M41T62_FEATURE_BL (1 << 1)
51
52 #define M41T80_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */
53
rtc_get(struct rtc_time * tm)54 int rtc_get(struct rtc_time *tm)
55 {
56 u8 buf[M41T62_DATETIME_REG_SIZE];
57
58 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
59
60 debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
61 "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
62 __FUNCTION__,
63 buf[0], buf[1], buf[2], buf[3],
64 buf[4], buf[5], buf[6], buf[7]);
65
66 tm->tm_sec = bcd2bin(buf[M41T62_REG_SEC] & 0x7f);
67 tm->tm_min = bcd2bin(buf[M41T62_REG_MIN] & 0x7f);
68 tm->tm_hour = bcd2bin(buf[M41T62_REG_HOUR] & 0x3f);
69 tm->tm_mday = bcd2bin(buf[M41T62_REG_DAY] & 0x3f);
70 tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07;
71 tm->tm_mon = bcd2bin(buf[M41T62_REG_MON] & 0x1f);
72
73 /* assume 20YY not 19YY, and ignore the Century Bit */
74 /* U-Boot needs to add 1900 here */
75 tm->tm_year = bcd2bin(buf[M41T62_REG_YEAR]) + 100 + 1900;
76
77 debug("%s: tm is secs=%d, mins=%d, hours=%d, "
78 "mday=%d, mon=%d, year=%d, wday=%d\n",
79 __FUNCTION__,
80 tm->tm_sec, tm->tm_min, tm->tm_hour,
81 tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
82
83 return 0;
84 }
85
rtc_set(struct rtc_time * tm)86 int rtc_set(struct rtc_time *tm)
87 {
88 u8 buf[M41T62_DATETIME_REG_SIZE];
89
90 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
91 tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
92 tm->tm_hour, tm->tm_min, tm->tm_sec);
93
94 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE);
95
96 /* Merge time-data and register flags into buf[0..7] */
97 buf[M41T62_REG_SSEC] = 0;
98 buf[M41T62_REG_SEC] =
99 bin2bcd(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f);
100 buf[M41T62_REG_MIN] =
101 bin2bcd(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f);
102 buf[M41T62_REG_HOUR] =
103 bin2bcd(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ;
104 buf[M41T62_REG_WDAY] =
105 (tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07);
106 buf[M41T62_REG_DAY] =
107 bin2bcd(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f);
108 buf[M41T62_REG_MON] =
109 bin2bcd(tm->tm_mon) | (buf[M41T62_REG_MON] & ~0x1f);
110 /* assume 20YY not 19YY */
111 buf[M41T62_REG_YEAR] = bin2bcd(tm->tm_year % 100);
112
113 if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) {
114 printf("I2C write failed in %s()\n", __func__);
115 return -1;
116 }
117
118 return 0;
119 }
120
rtc_reset(void)121 void rtc_reset(void)
122 {
123 u8 val;
124
125 /*
126 * M41T82: Make sure HT (Halt Update) bit is cleared.
127 * This bit is 0 in M41T62 so its save to clear it always.
128 */
129 i2c_read(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
130 val &= ~M41T80_ALHOUR_HT;
131 i2c_write(CONFIG_SYS_I2C_RTC_ADDR, M41T62_REG_ALARM_HOUR, 1, &val, 1);
132 }
133
134 #endif
135