3 * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
5 * SPDX-License-Identifier: GPL-2.0+
9 * Date & Time support for ST Electronics M48T35Ax RTC
20 #if defined(CONFIG_CMD_DATE)
22 static uchar rtc_read (uchar reg);
23 static void rtc_write (uchar reg, uchar val);
25 /* ------------------------------------------------------------------------- */
27 int rtc_get (struct rtc_time *tmp)
29 uchar sec, min, hour, cent_day, date, month, year;
30 uchar ccr; /* Clock control register */
32 /* Lock RTC for read using clock control register */
39 hour = rtc_read (0x3);
40 cent_day= rtc_read (0x4);
41 date = rtc_read (0x5);
42 month = rtc_read (0x6);
43 year = rtc_read (0x7);
50 debug ( "Get RTC year: %02x month: %02x date: %02x cent_day: %02x "
51 "hr: %02x min: %02x sec: %02x\n",
52 year, month, date, cent_day,
55 tmp->tm_sec = bcd2bin (sec & 0x7F);
56 tmp->tm_min = bcd2bin (min & 0x7F);
57 tmp->tm_hour = bcd2bin (hour & 0x3F);
58 tmp->tm_mday = bcd2bin (date & 0x3F);
59 tmp->tm_mon = bcd2bin (month & 0x1F);
60 tmp->tm_year = bcd2bin (year) + ((cent_day & 0x10) ? 2000 : 1900);
61 tmp->tm_wday = bcd2bin (cent_day & 0x07);
65 debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
66 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
67 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
72 int rtc_set (struct rtc_time *tmp)
74 uchar ccr; /* Clock control register */
77 debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
78 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
79 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
81 /* Lock RTC for write using clock control register */
86 rtc_write (0x07, bin2bcd(tmp->tm_year % 100));
87 rtc_write (0x06, bin2bcd(tmp->tm_mon));
88 rtc_write (0x05, bin2bcd(tmp->tm_mday));
90 century = ((tmp->tm_year >= 2000) ? 0x10 : 0) | 0x20;
91 rtc_write (0x04, bin2bcd(tmp->tm_wday) | century);
93 rtc_write (0x03, bin2bcd(tmp->tm_hour));
94 rtc_write (0x02, bin2bcd(tmp->tm_min ));
95 rtc_write (0x01, bin2bcd(tmp->tm_sec ));
105 void rtc_reset (void)
109 /* Clear all clock control registers */
110 rtc_write (0x0, 0x80); /* No Read Lock or calibration */
113 val = rtc_read (0x1);
117 /* Enable century / disable frequency test */
118 val = rtc_read (0x4);
119 val = (val & 0xBF) | 0x20;
122 /* Clear write lock */
126 /* ------------------------------------------------------------------------- */
128 static uchar rtc_read (uchar reg)
130 return *(unsigned char *)
131 ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg);
134 static void rtc_write (uchar reg, uchar val)
137 ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg) = val;