drivers/rtc: add Marvell Integrated RTC

This driver can be used for kirkwood SoCs by enabling CONFIG_RTC_MV.  Tested on
Global Scale Technologies Dreamplug.

Signed-off-by: Jason Cooper <u-boot@lakedaemon.net>

1 files changed, 124 insertions, 0 deletions

diff --git a/drivers/rtc/mvrtc.c b/drivers/rtc/mvrtc.c
new file mode 100644
index 0000000..ccc573a
--- /dev/null
+++ b/drivers/rtc/mvrtc.c
@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2011
+ * Jason Cooper <u-boot@lakedaemon.net>
+ *
+ * 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 Marvell Integrated RTC
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include "mvrtc.h"
+
+/* This RTC does not support century, so we assume 20 */
+#define CENTURY 20
+
+int rtc_get(struct rtc_time *t)
+{
+	u32 time;
+	u32 date;
+	struct mvrtc_registers *mvrtc_regs;
+
+	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
+
+	/* read the time register */
+	time = readl(&mvrtc_regs->time);
+
+	/* read the date register */
+	date = readl(&mvrtc_regs->date);
+
+	/* test for 12 hour clock (can't tell if it's am/pm) */
+	if (time & MVRTC_HRFMT_MSK) {
+		printf("Error: RTC in 12 hour mode, can't determine AM/PM.\n");
+		return -1;
+	}
+
+	/* time */
+	t->tm_sec  = bcd2bin((time >> MVRTC_SEC_SFT)  & MVRTC_SEC_MSK);
+	t->tm_min  = bcd2bin((time >> MVRTC_MIN_SFT)  & MVRTC_MIN_MSK);
+	t->tm_hour = bcd2bin((time >> MVRTC_HOUR_SFT) & MVRTC_HOUR_MSK);
+	t->tm_wday = bcd2bin((time >> MVRTC_DAY_SFT)  & MVRTC_DAY_MSK);
+	t->tm_wday--;
+
+	/* date */
+	t->tm_mday = bcd2bin((date >> MVRTC_DATE_SFT) & MVRTC_DATE_MSK);
+	t->tm_mon  = bcd2bin((date >> MVRTC_MON_SFT)  & MVRTC_MON_MSK);
+	t->tm_year = bcd2bin((date >> MVRTC_YEAR_SFT) & MVRTC_YEAR_MSK);
+	t->tm_year += CENTURY * 100;
+
+	/* not supported in this RTC */
+	t->tm_yday  = 0;
+	t->tm_isdst = 0;
+
+	return 0;
+}
+
+int rtc_set(struct rtc_time *t)
+{
+	u32 time = 0; /* sets hour format bit to zero, 24hr format. */
+	u32 date = 0;
+	struct mvrtc_registers *mvrtc_regs;
+
+	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
+
+	/* check that this code isn't 80+ years old ;-) */
+	if ((t->tm_year / 100) != CENTURY)
+		printf("Warning: Only century %d supported.\n", CENTURY);
+
+	/* time */
+	time |= (bin2bcd(t->tm_sec)      & MVRTC_SEC_MSK)  << MVRTC_SEC_SFT;
+	time |= (bin2bcd(t->tm_min)      & MVRTC_MIN_MSK)  << MVRTC_MIN_SFT;
+	time |= (bin2bcd(t->tm_hour)     & MVRTC_HOUR_MSK) << MVRTC_HOUR_SFT;
+	time |= (bin2bcd(t->tm_wday + 1) & MVRTC_DAY_MSK)  << MVRTC_DAY_SFT;
+
+	/* date */
+	date |= (bin2bcd(t->tm_mday)       & MVRTC_DATE_MSK) << MVRTC_DATE_SFT;
+	date |= (bin2bcd(t->tm_mon)        & MVRTC_MON_MSK)  << MVRTC_MON_SFT;
+	date |= (bin2bcd(t->tm_year % 100) & MVRTC_YEAR_MSK) << MVRTC_YEAR_SFT;
+
+	/* write the time register */
+	writel(time, &mvrtc_regs->time);
+
+	/* write the date register */
+	writel(date, &mvrtc_regs->date);
+
+	return 0;
+}
+
+void rtc_reset(void)
+{
+	u32 time;
+	u32 sec;
+	struct mvrtc_registers *mvrtc_regs;
+
+	mvrtc_regs = (struct mvrtc_registers *)KW_RTC_BASE;
+
+	/* no init routine for this RTC needed, just check that it's working */
+	time = readl(&mvrtc_regs->time);
+	sec  = bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK);
+	udelay(1000000);
+	time = readl(&mvrtc_regs->time);
+
+	if (sec == bcd2bin((time >> MVRTC_SEC_SFT) & MVRTC_SEC_MSK))
+		printf("Error: RTC did not increment.\n");
+}