iMX28: Add driver for internal RTC

[karo-tx-uboot.git] / drivers / rtc / mxsrtc.c

diff --git a/drivers/rtc/mxsrtc.c b/drivers/rtc/mxsrtc.c
new file mode 100644 (file)
index 0000000..5beb1a0
--- /dev/null
+++ b/drivers/rtc/mxsrtc.c
@@ -0,0 +1,86 @@
+/*
+ * Freescale i.MX28 RTC Driver
+ *
+ * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * 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
+ *
+ */
+
+#include <common.h>
+#include <rtc.h>
+#include <asm/io.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/sys_proto.h>
+
+#define        MXS_RTC_MAX_TIMEOUT     1000000
+
+/* Set time in seconds since 1970-01-01 */
+int mxs_rtc_set_time(uint32_t secs)
+{
+       struct mx28_rtc_regs *rtc_regs = (struct mx28_rtc_regs *)MXS_RTC_BASE;
+       int ret;
+
+       writel(secs, &rtc_regs->hw_rtc_seconds);
+
+       /*
+        * The 0x80 here means seconds were copied to analog. This information
+        * is taken from the linux kernel driver for the STMP37xx RTC since
+        * documentation doesn't mention it.
+        */
+       ret = mx28_wait_mask_clr(&rtc_regs->hw_rtc_stat_reg,
+               0x80 << RTC_STAT_STALE_REGS_OFFSET, MXS_RTC_MAX_TIMEOUT);
+
+       if (ret)
+               printf("MXS RTC: Timeout waiting for update\n");
+
+       return ret;
+}
+
+int rtc_get(struct rtc_time *time)
+{
+       struct mx28_rtc_regs *rtc_regs = (struct mx28_rtc_regs *)MXS_RTC_BASE;
+       uint32_t secs;
+
+       secs = readl(&rtc_regs->hw_rtc_seconds);
+       to_tm(secs, time);
+
+       return 0;
+}
+
+int rtc_set(struct rtc_time *time)
+{
+       uint32_t secs;
+
+       secs = mktime(time->tm_year, time->tm_mon, time->tm_mday,
+               time->tm_hour, time->tm_min, time->tm_sec);
+
+       return mxs_rtc_set_time(secs);
+}
+
+void rtc_reset(void)
+{
+       struct mx28_rtc_regs *rtc_regs = (struct mx28_rtc_regs *)MXS_RTC_BASE;
+       int ret;
+
+       /* Set time to 1970-01-01 */
+       mxs_rtc_set_time(0);
+
+       /* Reset the RTC block */
+       ret = mx28_reset_block(&rtc_regs->hw_rtc_ctrl_reg);
+       if (ret)
+               printf("MXS RTC: Block reset timeout\n");
+}