Initial revision

1 files changed, 202 insertions, 0 deletions

diff --git a/rtc/ds174x.c b/rtc/ds174x.c
new file mode 100644
index 000000000..58b13e9da
--- /dev/null
+++ b/rtc/ds174x.c
@@ -0,0 +1,202 @@
+/*
+ * (C) Copyright 2001
+ * ARIO Data Networks, Inc. dchiu@ariodata.com
+ *
+ * Based on MontaVista DS1743 code and U-Boot mc146818 code
+ *
+ * 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 the DS174x RTC
+ */
+
+/*#define	DEBUG*/
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+
+#if defined(CONFIG_RTC_DS174x) && (CONFIG_COMMANDS & CFG_CMD_DATE)
+
+static uchar rtc_read( unsigned int addr );
+static void  rtc_write( unsigned int addr, uchar val);
+static uchar bin2bcd   (unsigned int n);
+static unsigned bcd2bin(uchar c);
+
+#define RTC_BASE		( CFG_NVRAM_SIZE + CFG_NVRAM_BASE_ADDR )
+
+#define RTC_YEAR		( RTC_BASE + 7 )
+#define RTC_MONTH		( RTC_BASE + 6 )
+#define RTC_DAY_OF_MONTH	( RTC_BASE + 5 )
+#define RTC_DAY_OF_WEEK		( RTC_BASE + 4 )
+#define RTC_HOURS		( RTC_BASE + 3 )
+#define RTC_MINUTES		( RTC_BASE + 2 )
+#define RTC_SECONDS		( RTC_BASE + 1 )
+#define RTC_CENTURY		( RTC_BASE + 0 )
+
+#define RTC_CONTROLA		RTC_CENTURY
+#define RTC_CONTROLB		RTC_SECONDS
+#define RTC_CONTROLC		RTC_DAY_OF_WEEK
+
+#define RTC_CA_WRITE		0x80
+#define RTC_CA_READ		0x40
+
+#define RTC_CB_OSC_DISABLE	0x80
+
+#define RTC_CC_BATTERY_FLAG	0x80
+#define RTC_CC_FREQ_TEST	0x40
+
+/* ------------------------------------------------------------------------- */
+
+void rtc_get( struct rtc_time *tmp )
+{
+	uchar sec, min, hour;
+	uchar mday, wday, mon, year;
+
+	int century;
+
+	uchar reg_a;
+
+	reg_a = rtc_read( RTC_CONTROLA );
+	/* lock clock registers for read */
+	rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
+
+	sec     = rtc_read( RTC_SECONDS );
+	min     = rtc_read( RTC_MINUTES );
+	hour    = rtc_read( RTC_HOURS );
+	mday    = rtc_read( RTC_DAY_OF_MONTH );
+	wday    = rtc_read( RTC_DAY_OF_WEEK );
+	mon     = rtc_read( RTC_MONTH );
+	year    = rtc_read( RTC_YEAR );
+	century = rtc_read( RTC_CENTURY );
+
+	/* unlock clock registers after read */
+	rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
+
+#ifdef RTC_DEBUG
+	printf( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
+		"hr: %02x min: %02x sec: %02x\n",
+		year, mon_cent, mday, wday,
+		hour, min, sec );
+#endif
+	tmp->tm_sec  = bcd2bin( sec  & 0x7F );
+	tmp->tm_min  = bcd2bin( min  & 0x7F );
+	tmp->tm_hour = bcd2bin( hour & 0x3F );
+	tmp->tm_mday = bcd2bin( mday & 0x3F );
+	tmp->tm_mon  = bcd2bin( mon & 0x1F );
+	tmp->tm_wday = bcd2bin( wday & 0x07 );
+
+	/* glue year from century and year in century */
+	tmp->tm_year = bcd2bin( year ) +
+		( bcd2bin( century & 0x3F ) * 100 );
+
+	tmp->tm_yday = 0;
+	tmp->tm_isdst= 0;
+#ifdef RTC_DEBUG
+	printf( "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 );
+#endif
+}
+
+void rtc_set( struct rtc_time *tmp )
+{
+	uchar reg_a;
+#ifdef RTC_DEBUG
+	printf( "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);
+#endif
+	/* lock clock registers for write */
+	reg_a = rtc_read( RTC_CONTROLA );
+	rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
+
+	rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
+
+	rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
+	rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
+	rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
+	rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
+	rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
+
+	/* break year up into century and year in century */
+	rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
+	rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
+
+	/* unlock clock registers after read */
+	rtc_write( RTC_CONTROLA, ( reg_a  & ~RTC_CA_WRITE ));
+}
+
+void rtc_reset (void)
+{
+	uchar reg_a, reg_b, reg_c;
+
+	reg_a = rtc_read( RTC_CONTROLA );
+	reg_b = rtc_read( RTC_CONTROLB );
+
+	if ( reg_b & RTC_CB_OSC_DISABLE )
+	{
+		printf( "real-time-clock was stopped. Now starting...\n" );
+		reg_a |= RTC_CA_WRITE;
+		reg_b &= ~RTC_CB_OSC_DISABLE;
+
+		rtc_write( RTC_CONTROLA, reg_a );
+		rtc_write( RTC_CONTROLB, reg_b );
+	}
+
+	/* make sure read/write clock register bits are cleared */
+	reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
+	rtc_write( RTC_CONTROLA, reg_a );
+
+	reg_c = rtc_read( RTC_CONTROLC );
+	if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
+		printf( "RTC battery low. Clock setting may not be reliable.\n" );
+}
+
+/* ------------------------------------------------------------------------- */
+
+static uchar rtc_read( unsigned int addr )
+{
+	uchar val = in8( addr );
+#ifdef RTC_DEBUG
+	printf( "rtc_read: %x:%x\n", addr, val );
+#endif
+	return( val );
+}
+
+static void rtc_write( unsigned int addr, uchar val )
+{
+#ifdef RTC_DEBUG
+	printf( "rtc_write: %x:%x\n", addr, val );
+#endif
+	out8( addr, 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_MC146818 && CFG_CMD_DATE */