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authorTor Krill <tor@excito.com>2008-03-15 15:40:26 +0100
committerWolfgang Denk <wd@denx.de>2008-03-16 01:21:30 +0100
commit9536dfcce03e7be4ccbceb47a08d9ba07ada362f (patch)
tree61b40621e4d56a619c34a7e92743150ebd763628 /drivers/rtc/isl1208.c
parent0210cff3d079d97b2156b13685ee8de368e68a1a (diff)
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Add support for Intersil isl1208 RTC
Signed-off-by: Tor Krill <tor@excito.com>
Diffstat (limited to 'drivers/rtc/isl1208.c')
-rw-r--r--drivers/rtc/isl1208.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/rtc/isl1208.c b/drivers/rtc/isl1208.c
new file mode 100644
index 0000000..d872802
--- /dev/null
+++ b/drivers/rtc/isl1208.c
@@ -0,0 +1,166 @@
+/*
+ * (C) Copyright 2008
+ * Tor Krill, Excito Elektronik i Skåne , tor@excito.com
+ *
+ * Modelled after the ds1337 driver
+ *
+ * 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 (no alarms) for Intersil
+ * ISL1208 Real Time Clock (RTC).
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include <i2c.h>
+
+/*---------------------------------------------------------------------*/
+#ifdef DEBUG_RTC
+#define DEBUGR(fmt,args...) printf(fmt ,##args)
+#else
+#define DEBUGR(fmt,args...)
+#endif
+/*---------------------------------------------------------------------*/
+
+/*
+ * RTC register addresses
+ */
+
+#define RTC_SEC_REG_ADDR 0x0
+#define RTC_MIN_REG_ADDR 0x1
+#define RTC_HR_REG_ADDR 0x2
+#define RTC_DATE_REG_ADDR 0x3
+#define RTC_MON_REG_ADDR 0x4
+#define RTC_YR_REG_ADDR 0x5
+#define RTC_DAY_REG_ADDR 0x6
+#define RTC_STAT_REG_ADDR 0x7
+/*
+ * RTC control register bits
+ */
+
+/*
+ * RTC status register bits
+ */
+#define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */
+#define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */
+#define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */
+#define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */
+#define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */
+#define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */
+
+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);
+
+/*
+ * Get the current time from the RTC
+ */
+
+void rtc_get (struct rtc_time *tmp)
+{
+ uchar sec, min, hour, mday, wday, mon, year, status;
+
+ status = rtc_read (RTC_STAT_REG_ADDR);
+ 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 status: %02x\n",
+ year, mon, mday, wday, hour, min, sec, status);
+
+ if (status & RTC_STAT_BIT_RTCF) {
+ printf ("### Warning: RTC oscillator has stopped\n");
+ rtc_write(RTC_STAT_REG_ADDR,
+ rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF));
+ }
+
+ 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)+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);
+
+ /* enable write */
+ rtc_write(RTC_STAT_REG_ADDR,
+ rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC);
+
+ 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) | 0x80 ); /* 24h clock */
+ rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
+ rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
+
+ /* disable write */
+ rtc_write(RTC_STAT_REG_ADDR,
+ rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC);
+}
+
+void rtc_reset (void)
+{
+}
+
+/*
+ * Helper functions
+ */
+
+static uchar rtc_read (uchar reg)
+{
+ return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
+}
+
+static void rtc_write (uchar reg, uchar val)
+{
+ i2c_reg_write (CFG_I2C_RTC_ADDR, 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));
+}