rtc: Add Xicor/Intersil X1205 RTC support

This patch adds support for the Xicor/Intersil X1205 RTC used on the
AMCC Makalu eval board. This driver is basically cloned from the Linux
driver version (2.6.23).

This patch also introduces the Linux bcd.h header for the BCD2BIN/
BIN2BCD conversions. In the future some of the other U-Boot RTC driver
should be converted to also use this header instead of implementing
their own local copy of these functions/macros.

Signed-off-by: Stefan Roese <sr@denx.de>

3 files changed, 199 insertions, 1 deletions

diff --git a/include/bcd.h b/include/bcd.h
new file mode 100644
index 0000000000..c545308125
--- /dev/null
+++ b/include/bcd.h
@@ -0,0 +1,20 @@
+/* Permission is hereby granted to copy, modify and redistribute this code
+ * in terms of the GNU Library General Public License, Version 2 or later,
+ * at your option.
+ */
+
+/* macros to translate to/from binary and binary-coded decimal (frequently
+ * found in RTC chips).
+ */
+
+#ifndef _BCD_H
+#define _BCD_H
+
+#define BCD2BIN(val)	(((val) & 0x0f) + ((val)>>4)*10)
+#define BIN2BCD(val)	((((val)/10)<<4) + (val)%10)
+
+/* backwards compat */
+#define BCD_TO_BIN(val) ((val)=BCD2BIN(val))
+#define BIN_TO_BCD(val) ((val)=BIN2BCD(val))
+
+#endif /* _BCD_H */
diff --git a/rtc/Makefile b/rtc/Makefile
index 2e6f3bdddf..5a0cf113a5 100644
--- a/rtc/Makefile
+++ b/rtc/Makefile
@@ -32,7 +32,7 @@ COBJS	= date.o   \
 	  ds1337.o ds1374.o ds1556.o ds164x.o ds174x.o ds3231.o \
 	  m41t11.o max6900.o m48t35ax.o mc146818.o mk48t59.o \
 	  mpc5xxx.o mpc8xx.o pcf8563.o s3c24x0_rtc.o rs5c372.o \
-	  mcfrtc.o
+	  mcfrtc.o x1205.o
 
 SRCS	:= $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(COBJS))
diff --git a/rtc/x1205.c b/rtc/x1205.c
new file mode 100644
index 0000000000..319f0512ca
--- /dev/null
+++ b/rtc/x1205.c
@@ -0,0 +1,178 @@
+/*
+ * (C) Copyright 2007
+ * Stefan Roese, DENX Software Engineering, sr@denx.de.
+ *
+ * based on a the Linux rtc-x1207.c driver which is:
+ *	Copyright 2004 Karen Spearel
+ *	Copyright 2005 Alessandro Zummo
+ *
+ * Information and datasheet:
+ * http://www.intersil.com/cda/deviceinfo/0,1477,X1205,00.html
+ *
+ * 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 Xicor/Intersil X1205 RTC
+ */
+
+/* #define	DEBUG	*/
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include <i2c.h>
+#include <bcd.h>
+
+#if defined(CONFIG_RTC_X1205) && defined(CONFIG_CMD_DATE)
+
+#define CCR_SEC			0
+#define CCR_MIN			1
+#define CCR_HOUR		2
+#define CCR_MDAY		3
+#define CCR_MONTH		4
+#define CCR_YEAR		5
+#define CCR_WDAY		6
+#define CCR_Y2K			7
+
+#define X1205_REG_SR		0x3F	/* status register */
+#define X1205_REG_Y2K		0x37
+#define X1205_REG_DW		0x36
+#define X1205_REG_YR		0x35
+#define X1205_REG_MO		0x34
+#define X1205_REG_DT		0x33
+#define X1205_REG_HR		0x32
+#define X1205_REG_MN		0x31
+#define X1205_REG_SC		0x30
+#define X1205_REG_DTR		0x13
+#define X1205_REG_ATR		0x12
+#define X1205_REG_INT		0x11
+#define X1205_REG_0		0x10
+#define X1205_REG_Y2K1		0x0F
+#define X1205_REG_DWA1		0x0E
+#define X1205_REG_YRA1		0x0D
+#define X1205_REG_MOA1		0x0C
+#define X1205_REG_DTA1		0x0B
+#define X1205_REG_HRA1		0x0A
+#define X1205_REG_MNA1		0x09
+#define X1205_REG_SCA1		0x08
+#define X1205_REG_Y2K0		0x07
+#define X1205_REG_DWA0		0x06
+#define X1205_REG_YRA0		0x05
+#define X1205_REG_MOA0		0x04
+#define X1205_REG_DTA0		0x03
+#define X1205_REG_HRA0		0x02
+#define X1205_REG_MNA0		0x01
+#define X1205_REG_SCA0		0x00
+
+#define X1205_CCR_BASE		0x30	/* Base address of CCR */
+#define X1205_ALM0_BASE		0x00	/* Base address of ALARM0 */
+
+#define X1205_SR_RTCF		0x01	/* Clock failure */
+#define X1205_SR_WEL		0x02	/* Write Enable Latch */
+#define X1205_SR_RWEL		0x04	/* Register Write Enable */
+
+#define X1205_DTR_DTR0		0x01
+#define X1205_DTR_DTR1		0x02
+#define X1205_DTR_DTR2		0x04
+
+#define X1205_HR_MIL		0x80	/* Set in ccr.hour for 24 hr mode */
+
+static void rtc_write(int reg, u8 val)
+{
+	i2c_write(CFG_I2C_RTC_ADDR, reg, 2, &val, 1);
+}
+
+/*
+ * In the routines that deal directly with the x1205 hardware, we use
+ * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch
+ * Epoch is initialized as 2000. Time is set to UTC.
+ */
+void rtc_get(struct rtc_time *tm)
+{
+	u8 buf[8];
+
+	i2c_read(CFG_I2C_RTC_ADDR, X1205_CCR_BASE, 2, buf, 8);
+
+	debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, "
+	      "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n",
+	      __FUNCTION__,
+	      buf[0], buf[1], buf[2], buf[3],
+	      buf[4], buf[5], buf[6], buf[7]);
+
+	tm->tm_sec = BCD2BIN(buf[CCR_SEC]);
+	tm->tm_min = BCD2BIN(buf[CCR_MIN]);
+	tm->tm_hour = BCD2BIN(buf[CCR_HOUR] & 0x3F); /* hr is 0-23 */
+	tm->tm_mday = BCD2BIN(buf[CCR_MDAY]);
+	tm->tm_mon = BCD2BIN(buf[CCR_MONTH]); /* mon is 0-11 */
+	tm->tm_year = BCD2BIN(buf[CCR_YEAR])
+		+ (BCD2BIN(buf[CCR_Y2K]) * 100);
+	tm->tm_wday = buf[CCR_WDAY];
+
+	debug("%s: tm is secs=%d, mins=%d, hours=%d, "
+	      "mday=%d, mon=%d, year=%d, wday=%d\n",
+	      __FUNCTION__,
+	      tm->tm_sec, tm->tm_min, tm->tm_hour,
+	      tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
+}
+
+void rtc_set(struct rtc_time *tm)
+{
+	int i;
+	u8 buf[8];
+
+	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
+	      tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
+	      tm->tm_hour, tm->tm_min, tm->tm_sec);
+
+	buf[CCR_SEC] = BIN2BCD(tm->tm_sec);
+	buf[CCR_MIN] = BIN2BCD(tm->tm_min);
+
+	/* set hour and 24hr bit */
+	buf[CCR_HOUR] = BIN2BCD(tm->tm_hour) | X1205_HR_MIL;
+
+	buf[CCR_MDAY] = BIN2BCD(tm->tm_mday);
+
+	/* month, 1 - 12 */
+	buf[CCR_MONTH] = BIN2BCD(tm->tm_mon);
+
+	/* year, since the rtc epoch*/
+	buf[CCR_YEAR] = BIN2BCD(tm->tm_year % 100);
+	buf[CCR_WDAY] = tm->tm_wday & 0x07;
+	buf[CCR_Y2K] = BIN2BCD(tm->tm_year / 100);
+
+	/* this sequence is required to unlock the chip */
+	rtc_write(X1205_REG_SR, X1205_SR_WEL);
+	rtc_write(X1205_REG_SR, X1205_SR_WEL | X1205_SR_RWEL);
+
+	/* write register's data */
+	for (i = 0; i < 8; i++)
+		rtc_write(X1205_CCR_BASE + i, buf[i]);
+
+	rtc_write(X1205_REG_SR, 0);
+}
+
+void rtc_reset(void)
+{
+	/*
+	 * Nothing to do
+	 */
+}
+
+#endif