rewrite/cleanup Blackfin RTC driver

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 117 insertions, 0 deletions

diff --git a/drivers/rtc/bfin_rtc.c b/drivers/rtc/bfin_rtc.c
new file mode 100644
index 0000000..5755a20
--- /dev/null
+++ b/drivers/rtc/bfin_rtc.c
@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2004-2008 Analog Devices Inc.
+ *
+ * (C) Copyright 2001
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+
+#if defined(CONFIG_RTC_BFIN) && defined(CONFIG_CMD_DATE)
+
+#include <asm/blackfin.h>
+#include <asm/mach-common/bits/rtc.h>
+
+#define pr_stamp() debug("%s:%s:%i: here i am\n", __FILE__, __func__, __LINE__)
+
+#define MIN_TO_SECS(x)    (60 * (x))
+#define HRS_TO_SECS(x)    (60 * MIN_TO_SECS(x))
+#define DAYS_TO_SECS(x)   (24 * HRS_TO_SECS(x))
+
+#define NUM_SECS_IN_MIN   MIN_TO_SECS(1)
+#define NUM_SECS_IN_HR    HRS_TO_SECS(1)
+#define NUM_SECS_IN_DAY   DAYS_TO_SECS(1)
+
+/* Our on-chip RTC has no notion of "reset" */
+void rtc_reset(void)
+{
+	return;
+}
+
+/* Wait for pending writes to complete */
+static void wait_for_complete(void)
+{
+	pr_stamp();
+	while (!(bfin_read_RTC_ISTAT() & WRITE_COMPLETE))
+		if (!(bfin_read_RTC_ISTAT() & WRITE_PENDING))
+			break;
+	bfin_write_RTC_ISTAT(WRITE_COMPLETE);
+}
+
+/* Enable the RTC prescaler enable register */
+int rtc_init(void)
+{
+	pr_stamp();
+	bfin_write_RTC_PREN(0x1);
+	return 0;
+}
+
+/* Set the time. Get the time_in_secs which is the number of seconds since Jan 1970 and set the RTC registers
+ * based on this value.
+ */
+void rtc_set(struct rtc_time *tmp)
+{
+	unsigned long remain, days, hrs, mins, secs;
+
+	pr_stamp();
+
+	if (tmp == NULL) {
+		puts("Error setting the date/time\n");
+		return;
+	}
+
+	wait_for_complete();
+
+	/* Calculate number of seconds this incoming time represents */
+	remain = mktime(tmp->tm_year, tmp->tm_mon, tmp->tm_mday,
+	                tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
+
+	/* Figure out how many days since epoch */
+	days = remain / NUM_SECS_IN_DAY;
+
+	/* From the remaining secs, compute the hrs(0-23), mins(0-59) and secs(0-59) */
+	remain = remain % NUM_SECS_IN_DAY;
+	hrs = remain / NUM_SECS_IN_HR;
+	remain = remain % NUM_SECS_IN_HR;
+	mins = remain / NUM_SECS_IN_MIN;
+	secs = remain % NUM_SECS_IN_MIN;
+
+	/* Encode these time values into our RTC_STAT register */
+	bfin_write_RTC_STAT(SET_ALARM(days, hrs, mins, secs));
+}
+
+/* Read the time from the RTC_STAT. time_in_seconds is seconds since Jan 1970 */
+void rtc_get(struct rtc_time *tmp)
+{
+	uint32_t cur_rtc_stat;
+	int time_in_sec;
+	int tm_sec, tm_min, tm_hr, tm_day;
+
+	pr_stamp();
+
+	if (tmp == NULL) {
+		puts("Error getting the date/time\n");
+		return;
+	}
+
+	wait_for_complete();
+
+	/* Read the RTC_STAT register */
+	cur_rtc_stat = bfin_read_RTC_STAT();
+
+	/* Convert our encoded format into actual time values */
+	tm_sec = (cur_rtc_stat & RTC_SEC) >> RTC_SEC_P;
+	tm_min = (cur_rtc_stat & RTC_MIN) >> RTC_MIN_P;
+	tm_hr  = (cur_rtc_stat & RTC_HR ) >> RTC_HR_P;
+	tm_day = (cur_rtc_stat & RTC_DAY) >> RTC_DAY_P;
+
+	/* Calculate the total number of seconds since epoch */
+	time_in_sec = (tm_sec) + MIN_TO_SECS(tm_min) + HRS_TO_SECS(tm_hr) + DAYS_TO_SECS(tm_day);
+	to_tm(time_in_sec, tmp);
+}
+
+#endif