u-boot/drivers/rtc/bfin_rtc.c
Mike Frysinger 3c87989834 Blackfin: only initialize the RTC when actually used
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2008-10-23 05:03:50 -04:00

123 lines
2.9 KiB
C

/*
* 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_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)
/* Enable the RTC prescaler enable register */
static void rtc_init(void)
{
if (!(bfin_read_RTC_PREN() & 0x1))
bfin_write_RTC_PREN(0x1);
}
/* Our on-chip RTC has no notion of "reset" */
void rtc_reset(void)
{
rtc_init();
}
/* 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);
}
/* 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.
*/
int 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 -1;
}
rtc_init();
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));
return 0;
}
/* Read the time from the RTC_STAT. time_in_seconds is seconds since Jan 1970 */
int 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 -1;
}
rtc_init();
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);
return 0;
}
#endif