Initial revision

1 files changed, 166 insertions, 0 deletions

diff --git a/rtc/m48t35ax.c b/rtc/m48t35ax.c
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--- /dev/null
+++ b/rtc/m48t35ax.c
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+/*
+ * (C) Copyright 2001
+ * Erik Theisen,  Wave 7 Optics, etheisen@mindspring.com.
+ *
+ * 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 as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * 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_RTC_M48T35A) && (CONFIG_COMMANDS & CFG_CMD_DATE)
+
+static uchar rtc_read  (uchar reg);
+static void  rtc_write (uchar reg, uchar val);
+static uchar bin2bcd   (unsigned int n);
+static unsigned bcd2bin(uchar c);
+
+/* ------------------------------------------------------------------------- */
+
+void 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);
+}
+
+void 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);
+}
+
+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 *)
+		((CFG_NVRAM_BASE_ADDR + CFG_NVRAM_SIZE - 8) + reg);
+	return val;
+}
+
+static void rtc_write (uchar reg, uchar val)
+{
+	*(unsigned char *)
+		((CFG_NVRAM_BASE_ADDR + CFG_NVRAM_SIZE - 8) + reg) = val;
+}
+
+static unsigned bcd2bin (uchar n)
+{
+	return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
+}
+
+static unsigned char bin2bcd (unsigned int n)
+{
+	return (((n / 10) << 4) | (n % 10));
+}
+
+#endif	/* CONFIG_RTC_M48T35A && CFG_CMD_DATE */