/* * (C) Copyright 2001 * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com. * * SPDX-License-Identifier: GPL-2.0+ */ /* * Date & Time support for ST Electronics M48T35Ax RTC */ /*#define DEBUG */ #include <common.h> #include <command.h> #include <rtc.h> #include <config.h> #if defined(CONFIG_CMD_DATE) static uchar rtc_read (uchar reg); static void rtc_write (uchar reg, uchar val); /* ------------------------------------------------------------------------- */ int rtc_get (struct rtc_time *tmp) { uchar sec, min, hour, cent_day, date, month, year; uchar ccr; /* Clock control register */ /* Lock RTC for read using clock control register */ ccr = rtc_read(0); ccr = ccr | 0x40; rtc_write(0, ccr); sec = rtc_read (0x1); min = rtc_read (0x2); hour = rtc_read (0x3); cent_day= rtc_read (0x4); date = rtc_read (0x5); month = rtc_read (0x6); year = rtc_read (0x7); /* UNLock RTC */ ccr = rtc_read(0); ccr = ccr & 0xBF; rtc_write(0, ccr); debug ( "Get RTC year: %02x month: %02x date: %02x cent_day: %02x " "hr: %02x min: %02x sec: %02x\n", year, month, date, cent_day, hour, min, sec ); tmp->tm_sec = bcd2bin (sec & 0x7F); tmp->tm_min = bcd2bin (min & 0x7F); tmp->tm_hour = bcd2bin (hour & 0x3F); tmp->tm_mday = bcd2bin (date & 0x3F); tmp->tm_mon = bcd2bin (month & 0x1F); tmp->tm_year = bcd2bin (year) + ((cent_day & 0x10) ? 2000 : 1900); tmp->tm_wday = bcd2bin (cent_day & 0x07); tmp->tm_yday = 0; tmp->tm_isdst= 0; debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, tmp->tm_hour, tmp->tm_min, tmp->tm_sec); return 0; } int rtc_set (struct rtc_time *tmp) { uchar ccr; /* Clock control register */ uchar century; debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, tmp->tm_hour, tmp->tm_min, tmp->tm_sec); /* Lock RTC for write using clock control register */ ccr = rtc_read(0); ccr = ccr | 0x80; rtc_write(0, ccr); rtc_write (0x07, bin2bcd(tmp->tm_year % 100)); rtc_write (0x06, bin2bcd(tmp->tm_mon)); rtc_write (0x05, bin2bcd(tmp->tm_mday)); century = ((tmp->tm_year >= 2000) ? 0x10 : 0) | 0x20; rtc_write (0x04, bin2bcd(tmp->tm_wday) | century); rtc_write (0x03, bin2bcd(tmp->tm_hour)); rtc_write (0x02, bin2bcd(tmp->tm_min )); rtc_write (0x01, bin2bcd(tmp->tm_sec )); /* UNLock RTC */ ccr = rtc_read(0); ccr = ccr & 0x7F; rtc_write(0, ccr); return 0; } void rtc_reset (void) { uchar val; /* Clear all clock control registers */ rtc_write (0x0, 0x80); /* No Read Lock or calibration */ /* Clear stop bit */ val = rtc_read (0x1); val &= 0x7f; rtc_write(0x1, val); /* Enable century / disable frequency test */ val = rtc_read (0x4); val = (val & 0xBF) | 0x20; rtc_write(0x4, val); /* Clear write lock */ rtc_write(0x0, 0); } /* ------------------------------------------------------------------------- */ static uchar rtc_read (uchar reg) { uchar val; val = *(unsigned char *) ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg); return val; } static void rtc_write (uchar reg, uchar val) { *(unsigned char *) ((CONFIG_SYS_NVRAM_BASE_ADDR + CONFIG_SYS_NVRAM_SIZE - 8) + reg) = val; } #endif