libpayload/drivers/nvram: Add function to write RTC

Add a function to set the RTC to provided struct tm.

Change-Id: I17b4c1ee0dcc649738ac6a7400b087d07213eaf0
Signed-off-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/23585
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
This commit is contained in:
Patrick Rudolph 2018-02-03 11:50:56 +01:00 committed by Patrick Georgi
parent 0beddb5e23
commit 77e0baa6e9
2 changed files with 53 additions and 0 deletions

View File

@ -160,3 +160,55 @@ void rtc_read_clock(struct tm *time)
if (time->tm_year < 80)
time->tm_year += 100;
}
/**
* Write the current time and date to the RTC
*
* @param time A pointer to a broken-down time structure
*/
void rtc_write_clock(const struct tm *time)
{
u16 timeout = 10000;
u8 statusB;
u8 reg8, year;
while (nvram_updating())
if (!timeout--)
return;
statusB = nvram_read(NVRAM_RTC_STATUSB);
year = time->tm_year;
if (year > 100)
year -= 100;
if (!(statusB & NVRAM_RTC_FORMAT_BINARY)) {
nvram_write(dec2bcd(time->tm_mon + 1), NVRAM_RTC_MONTH);
nvram_write(dec2bcd(time->tm_sec), NVRAM_RTC_SECONDS);
nvram_write(dec2bcd(time->tm_min), NVRAM_RTC_MINUTES);
nvram_write(dec2bcd(time->tm_mday), NVRAM_RTC_DAY);
if (!(statusB & NVRAM_RTC_FORMAT_24HOUR)) {
if (time->tm_hour > 12)
reg8 = dec2bcd(time->tm_hour - 12) | 0x80;
else
reg8 = dec2bcd(time->tm_hour);
} else
reg8 = dec2bcd(time->tm_hour);
nvram_write(reg8, NVRAM_RTC_HOURS);
nvram_write(dec2bcd(year), NVRAM_RTC_YEAR);
} else {
nvram_write(time->tm_mon + 1, NVRAM_RTC_MONTH);
nvram_write(time->tm_sec, NVRAM_RTC_SECONDS);
nvram_write(time->tm_min, NVRAM_RTC_MINUTES);
nvram_write(time->tm_mday, NVRAM_RTC_DAY);
if (!(statusB & NVRAM_RTC_FORMAT_24HOUR)) {
if (time->tm_hour > 12)
reg8 = (time->tm_hour - 12) | 0x80;
else
reg8 = time->tm_hour;
} else
reg8 = time->tm_hour;
nvram_write(reg8, NVRAM_RTC_HOURS);
nvram_write(year, NVRAM_RTC_YEAR);
}
}

View File

@ -151,6 +151,7 @@ u8 nvram_read(u8 addr);
void nvram_write(u8 val, u8 addr);
int nvram_updating(void);
void rtc_read_clock(struct tm *tm);
void rtc_write_clock(const struct tm *tm);
/** @} */
/**