ARM: DaVinci: add RTC driver

This is a simple forward port of the RTC driver, originally written by
TI, from the MV 2.6.10 kernel.
Signed-off-by: Kevin Hilman <khilman@mvista.com>

drivers/char/Kconfig

@@ -824,6 +824,12 @@ config S3C2410_RTC
 	  Samsung S3C2410. This can provide periodic interrupt rates
 	  from 1Hz to 64Hz for user programs, and wakeup from Alarm.
 
+config DAVINCI_RTC
+	bool "TI DaVinci Real Time Clock"
+	depends on ARCH_DAVINCI && MACH_DAVINCI_EVM && I2C_DAVINCI
+	help
+	  Support for TI DaVinci RTC
+
 config COBALT_LCD
 	bool "Support for Cobalt LCD"
 	depends on MIPS_COBALT

drivers/char/Makefile

@@ -99,6 +99,7 @@ obj-$(CONFIG_IPMI_HANDLER)	+= ipmi/
 
 obj-$(CONFIG_HANGCHECK_TIMER)	+= hangcheck-timer.o
 obj-$(CONFIG_TCG_TPM)		+= tpm/
+obj-$(CONFIG_DAVINCI_RTC)	+= davinci-rtc.o
 
 # Files generated that shall be removed upon make clean
 clean-files := consolemap_deftbl.c defkeymap.c qtronixmap.c

drivers/char/davinci-rtc.c

+/*
+ *  linux/drivers/char/rtc.c
+ *
+ * Copyright (C) 2004 Texas Instruments Inc
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * 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
+ * ----------------------------------------------------------------------------
+ Modifications:
+ ver. 1.0: Jan 2006, Swaminathan S
+ -
+ */
+
+#include <linux/config.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/proc_fs.h>
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <asm/rtc.h>
+#include <asm/arch/i2c-client.h>
+
+static unsigned char am;
+
+static int _rtc_read_time(struct rtc_time *tm);
+static int _rtc_set_time(struct rtc_time *tm);
+static void am_or_pm (void);
+
+static struct rtc_ops davinci_rtc_ops = {
+        .owner          = THIS_MODULE,
+        .read_time      = _rtc_read_time,
+        .set_time       = _rtc_set_time,
+};
+
+static unsigned long epoch = 1900;      /* year corresponding to 0x00   */
+
+static const unsigned char days_in_mo[] =
+{31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
+
+static int _rtc_read_time(struct rtc_time *tm)
+{
+	char rtcdata [9] = { 2, 1, 0, 0, 0, 0,
+			     0, 0, 0 };
+
+	davinci_i2c_write (2, rtcdata, 0x23);
+	udelay (1000);
+	davinci_i2c_read (9, rtcdata, 0x23);
+	udelay (1000);
+
+	tm->tm_year = BCD_TO_BIN (rtcdata[3]) * 100 + BCD_TO_BIN (rtcdata[2]) - 1900;
+	tm->tm_mon = BCD_TO_BIN (rtcdata[4]);
+	tm->tm_mday = BCD_TO_BIN (rtcdata[5]);
+	tm->tm_hour = BCD_TO_BIN (rtcdata[6]);
+	tm->tm_min = BCD_TO_BIN (rtcdata[7]);
+	tm->tm_sec = BCD_TO_BIN (rtcdata[8]);
+
+	return 0;
+}
+
+static int _rtc_set_time(struct rtc_time *tm)
+{
+	char rtcdata [9];
+	char ampmdata [9];
+	struct timespec tv;
+	unsigned char mon, day, hrs = 0, min, sec, leap_yr;
+	unsigned char yr_low, yr_high;
+	unsigned int yrs;
+
+	am_or_pm ();
+
+	yrs = tm->tm_year + 1900;
+	yr_high = yrs/100;
+	yr_low = (yrs) % 100;
+
+	mon = tm->tm_mon;
+	hrs = tm->tm_hour;
+	day = tm->tm_mday;
+	min = tm->tm_min;
+	sec = tm->tm_sec;
+
+	if (yrs < 1970 || yrs > 2037)
+                return -EINVAL;
+
+        leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
+
+	if ((mon > 11) || (day == 0))
+                return -EINVAL;
+
+        if (day > (days_in_mo[mon] + ((mon == 1) && leap_yr)))
+                return -EINVAL;
+
+        if ((hrs >= 24) || (min >= 60) || (sec >= 60))
+                return -EINVAL;
+
+        if ((yrs -= epoch) > 255) {    /* They are unsigned */
+                return -EINVAL;
+        }
+
+	if (am == 1 && tm->tm_hour <= 12) {
+		hrs = tm->tm_hour;
+		if (tm->tm_hour == 0)
+			hrs = tm->tm_hour + 12;
+	}
+
+	else if ((am == 1 && tm->tm_hour > 12) ||
+	    	 (am == 0 && tm->tm_hour < 12)) {
+		unsigned char mon1 = mon, day1 = day, hrs1 = 11, min1 = 59, sec1 = 59;
+		unsigned char yr_low1 = yr_low, yr_high1 = yr_high;
+
+		ampmdata [0] = 9;
+		ampmdata [1] = 0;
+		ampmdata [2] = BIN_TO_BCD(yr_low1);
+		ampmdata [3] = BIN_TO_BCD(yr_high1);
+		ampmdata [4] = BIN_TO_BCD(mon1);
+		ampmdata [5] = BIN_TO_BCD(day1);
+		ampmdata [6] = BIN_TO_BCD(hrs1);
+		ampmdata [7] = BIN_TO_BCD(min1);
+		ampmdata [8] = BIN_TO_BCD(sec1);
+		davinci_i2c_write (9, ampmdata, 0x23);
+		udelay (1000);
+		mdelay (1000);
+		am = (am == 1) ? 0 : 1;
+
+		if (!am)
+			hrs = tm->tm_hour - 12;
+		else if (tm->tm_hour == 0)
+			hrs = tm->tm_hour + 12;
+	}
+
+	else if (am == 0 && tm->tm_hour > 12) {
+		hrs = tm->tm_hour - 12;
+	}
+
+	rtcdata [0] = 9;
+	rtcdata [1] = 0;
+	rtcdata [2] = BIN_TO_BCD(yr_low);
+	rtcdata [3] = BIN_TO_BCD(yr_high);
+	rtcdata [4] = BIN_TO_BCD(mon);
+	rtcdata [5] = BIN_TO_BCD(day);
+	rtcdata [6] = BIN_TO_BCD(hrs);
+	rtcdata [7] = BIN_TO_BCD(min);
+	rtcdata [8] = BIN_TO_BCD(sec);
+	davinci_i2c_write (9, rtcdata, 0x23);
+	udelay (1000);
+
+	tv.tv_nsec = 0;
+        tv.tv_sec = mktime (tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
+				tm->tm_hour, tm->tm_min, tm->tm_sec+2);
+        do_settimeofday (&tv);
+
+	return 0;
+}
+
+static void am_or_pm (void)
+{
+	char rtcdata [9];
+	struct rtc_time tm, time, temp;
+	unsigned char mon, day, hrs, min, sec;
+	unsigned char yr_low, yr_high;
+	unsigned int yrs;
+
+	_rtc_read_time (&tm);
+
+	temp = tm;
+
+	yrs = temp.tm_year + 1900;
+	yr_high = yrs/100;
+	yr_low = (yrs) % 100;
+
+	mon = temp.tm_mon + 1;
+	day = temp.tm_mday;
+	min = 59;
+	sec = 59;
+	hrs = 11;
+
+	rtcdata [0] = 9;
+	rtcdata [1] = 0;
+	rtcdata [2] = BIN_TO_BCD(yr_low);
+	rtcdata [3] = BIN_TO_BCD(yr_high);
+	mon--;
+	rtcdata [4] = BIN_TO_BCD(mon);
+	rtcdata [5] = BIN_TO_BCD(day);
+	rtcdata [6] = BIN_TO_BCD(hrs);
+	rtcdata [7] = BIN_TO_BCD(min);
+	rtcdata [8] = BIN_TO_BCD(sec);
+	davinci_i2c_write (9, rtcdata, 0x23);
+	udelay (1000);
+	mdelay (1000);
+	_rtc_read_time (&time);
+
+	if (time.tm_mday == temp.tm_mday)
+		am = 1;
+	else
+		am = 0;
+
+	davinci_i2c_write (9, rtcdata, 0x23);
+	udelay (1000);
+	mdelay (1000);
+
+	yrs = tm.tm_year + 1900;
+	yr_high = yrs/100;
+	yr_low = (yrs) % 100;
+
+	mon = tm.tm_mon + 1;
+	day = tm.tm_mday;
+	min = tm.tm_min;
+	hrs = tm.tm_hour;
+	if (tm.tm_sec < 58)
+	{
+		sec = tm.tm_sec + 2;
+	} else {
+		sec = 59;
+	}
+
+	davinci_i2c_write (9, rtcdata, 0x23);
+	udelay (1000);
+}
+
+static int __init davinci_rtc_init(void)
+{
+	struct timespec tv;
+	struct rtc_time tm;
+        register_rtc (&davinci_rtc_ops);
+
+	am_or_pm ();
+
+	_rtc_read_time (&tm);
+
+        tv.tv_nsec = 0;
+        tv.tv_sec = mktime (tm.tm_year + 1900, tm.tm_mon + 1 , tm.tm_mday,
+				tm.tm_hour, tm.tm_min, tm.tm_sec);
+        do_settimeofday (&tv);
+
+	return 0;
+}
+
+module_init(davinci_rtc_init);