Add Epson RX8025 RTC support

Signed-off-by: Matthias Fuchs <matthias.fuchs@esd-electronics.com>

1 files changed, 227 insertions, 0 deletions

diff --git a/drivers/rtc/rx8025.c b/drivers/rtc/rx8025.c
new file mode 100644
index 0000000..6c94ae1
--- /dev/null
+++ b/drivers/rtc/rx8025.c
@@ -0,0 +1,227 @@
+/*
+ * (C) Copyright 2007
+ * Matthias Fuchs, esd gmbh, matthias.fuchs@esd-electronics.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
+ */
+
+/*
+ * Epson RX8025 RTC driver.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include <i2c.h>
+
+#if defined(CONFIG_RTC_RX8025) && defined(CONFIG_CMD_DATE)
+
+/*---------------------------------------------------------------------*/
+#undef DEBUG_RTC
+
+#ifdef DEBUG_RTC
+#define DEBUGR(fmt,args...) printf(fmt ,##args)
+#else
+#define DEBUGR(fmt,args...)
+#endif
+/*---------------------------------------------------------------------*/
+
+#ifndef CFG_I2C_RTC_ADDR
+# define CFG_I2C_RTC_ADDR	0x32
+#endif
+
+/*
+ * RTC register addresses
+ */
+#define RTC_SEC_REG_ADDR	0x00
+#define RTC_MIN_REG_ADDR	0x01
+#define RTC_HR_REG_ADDR		0x02
+#define RTC_DAY_REG_ADDR	0x03
+#define RTC_DATE_REG_ADDR	0x04
+#define RTC_MON_REG_ADDR	0x05
+#define RTC_YR_REG_ADDR		0x06
+
+#define RTC_CTL1_REG_ADDR	0x0e
+#define RTC_CTL2_REG_ADDR	0x0f
+
+/*
+ * Control register 1 bits
+ */
+#define RTC_CTL1_BIT_2412	0x20
+
+/*
+ * Control register 2 bits
+ */
+#define RTC_CTL2_BIT_PON	0x10
+#define RTC_CTL2_BIT_VDET	0x40
+#define RTC_CTL2_BIT_XST	0x20
+#define RTC_CTL2_BIT_VDSL	0x80
+
+/*
+ * Note: the RX8025 I2C RTC requires register
+ * reads and write to consist of a single bus
+ * cycle. It is not allowed to write the register
+ * address in a first cycle that is terminated by
+ * a STOP condition. The chips needs a 'restart'
+ * sequence (start sequence without a prior stop).
+ * This driver has been written for a 4xx board.
+ * U-Boot's 4xx i2c driver is currently not capable
+ * to generate such cycles to some work arounds
+ * are used.
+ */
+
+/* static uchar rtc_read (uchar reg); */
+#define rtc_read(reg) buf[((reg) + 1) & 0xf]
+
+static void rtc_write (uchar reg, uchar val);
+static uchar bin2bcd (unsigned int n);
+static unsigned bcd2bin (uchar c);
+
+/*
+ * Get the current time from the RTC
+ */
+void rtc_get (struct rtc_time *tmp)
+{
+	uchar sec, min, hour, mday, wday, mon, year, ctl2;
+	uchar buf[16];
+
+	if (i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 16))
+		printf("Error reading from RTC\n");
+
+	sec = rtc_read(RTC_SEC_REG_ADDR);
+	min = rtc_read(RTC_MIN_REG_ADDR);
+	hour = rtc_read(RTC_HR_REG_ADDR);
+	wday = rtc_read(RTC_DAY_REG_ADDR);
+	mday = rtc_read(RTC_DATE_REG_ADDR);
+	mon = rtc_read(RTC_MON_REG_ADDR);
+	year = rtc_read(RTC_YR_REG_ADDR);
+
+	DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
+		"hr: %02x min: %02x sec: %02x\n",
+		year, mon, mday, wday, hour, min, sec);
+
+	/* dump status */
+	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
+	if (ctl2 & RTC_CTL2_BIT_PON)
+		printf("RTC: power-on detected\n");
+
+	if (ctl2 & RTC_CTL2_BIT_VDET)
+		printf("RTC: voltage drop detected\n");
+
+	if (!(ctl2 & RTC_CTL2_BIT_XST))
+		printf("RTC: oscillator stop detected\n");
+
+	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_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
+	tmp->tm_wday = bcd2bin (wday & 0x07);
+	tmp->tm_yday = 0;
+	tmp->tm_isdst= 0;
+
+	DEBUGR ("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);
+}
+
+
+/*
+ * Set the RTC
+ */
+void rtc_set (struct rtc_time *tmp)
+{
+	DEBUGR ("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);
+
+	if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
+		printf("WARNING: year should be between 1970 and 2069!\n");
+
+	rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
+	rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
+	rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday));
+	rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
+	rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
+	rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
+	rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
+
+	rtc_write (RTC_CTL1_REG_ADDR, RTC_CTL1_BIT_2412);
+}
+
+
+/*
+ * Reset the RTC. We setting the date back to 1970-01-01.
+ */
+void rtc_reset (void)
+{
+	struct rtc_time tmp;
+	uchar buf[16];
+	uchar ctl2;
+
+	if (i2c_read(CFG_I2C_RTC_ADDR, 0,    0,   buf, 16))
+		printf("Error reading from RTC\n");
+
+	ctl2 = rtc_read(RTC_CTL2_REG_ADDR);
+	ctl2 &= ~(RTC_CTL2_BIT_PON | RTC_CTL2_BIT_VDET);
+	ctl2 |= RTC_CTL2_BIT_XST | RTC_CTL2_BIT_VDSL;
+	rtc_write (RTC_CTL2_REG_ADDR, ctl2);
+
+	tmp.tm_year = 1970;
+	tmp.tm_mon = 1;
+	tmp.tm_mday= 1;
+	tmp.tm_hour = 0;
+	tmp.tm_min = 0;
+	tmp.tm_sec = 0;
+
+	rtc_set(&tmp);
+
+	printf ( "RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
+		tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
+		tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
+
+	return;
+}
+
+
+/*
+ * Helper functions
+ */
+static void rtc_write (uchar reg, uchar val)
+{
+	uchar buf[2];
+	buf[0] = reg << 4;
+	buf[1] = val;
+	if (i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 2) != 0)
+		printf("Error writing to RTC\n");
+
+}
+
+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_RX8025 && (CFG_COMMANDS & CFG_CMD_DATE) */