RTC driver for MC13783

MC13783 is a multifunction IS with an SPI interface to the host. This
driver handles the RTC controller in this chip.

Signed-off-by: Guennadi Liakhovetski <lg@denx.de>

README

@@ -672,6 +672,7 @@ The following options need to be configured:
 
 		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx
 		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC
+		CONFIG_RTC_MC13783	- use MC13783 RTC
 		CONFIG_RTC_MC146818	- use MC146818 RTC
 		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
 		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC

drivers/rtc/Makefile

@@ -45,6 +45,7 @@ COBJS-y += m41t60.o
 COBJS-$(CONFIG_RTC_M41T62) += m41t62.o
 COBJS-y += m48t35ax.o
 COBJS-y += max6900.o
+COBJS-$(CONFIG_RTC_MC13783) += mc13783-rtc.o
 COBJS-y += mc146818.o
 COBJS-y += mcfrtc.o
 COBJS-y += mk48t59.o

drivers/rtc/mc13783-rtc.c

@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2008, Guennadi Liakhovetski <lg@denx.de>
+ *
+ * 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
+ */
+
+#include <common.h>
+#include <rtc.h>
+#include <spi.h>
+
+int rtc_get(struct rtc_time *rtc)
+{
+	u32 day1, day2, time;
+	u32 reg;
+	int err, tim, i = 0;
+
+	spi_select(1, 0, SPI_MODE_2 | SPI_CS_HIGH);
+
+	do {
+		reg = 0x2c000000;
+		err = spi_xfer(0, 32, (uchar *)&reg, (uchar *)&day1);
+
+		if (err)
+			return err;
+
+		reg = 0x28000000;
+		err = spi_xfer(0, 32, (uchar *)&reg, (uchar *)&time);
+
+		if (err)
+			return err;
+
+		reg = 0x2c000000;
+		err = spi_xfer(0, 32, (uchar *)&reg, (uchar *)&day2);
+
+		if (err)
+			return err;
+	} while (day1 != day2 && i++ < 3);
+
+	tim = day1 * 86400 + time;
+	to_tm(tim, rtc);
+
+	rtc->tm_yday = 0;
+	rtc->tm_isdst = 0;
+
+	return 0;
+}
+
+void rtc_set(struct rtc_time *rtc)
+{
+	u32 time, day, reg;
+
+	time = mktime(rtc->tm_year, rtc->tm_mon, rtc->tm_mday,
+		      rtc->tm_hour, rtc->tm_min, rtc->tm_sec);
+	day = time / 86400;
+	time %= 86400;
+
+	reg = 0x2c000000 | day | 0x80000000;
+	spi_xfer(0, 32, (uchar *)&reg, (uchar *)&day);
+
+	reg = 0x28000000 | time | 0x80000000;
+	spi_xfer(0, 32, (uchar *)&reg, (uchar *)&time);
+}
+
+void rtc_reset(void)
+{
+}