rockchip/rk3288: rtc-rk808: fix rtc time reading issue

After we set the GET_TIME bit, the rtc time can't be read immediately.  We
should wait up to 31.25 us, about one cycle of 32khz.  Otherwise reading
RTC time will return a old time.

BUG=chrome-os-partner:61078
BRANCH=veyron
TEST=Build and Boot

Original-Change-Id: I6ec07fc6c4d6d8b27b12031423b86b8ab15da6f6
Original-Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/423272
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>

Change-Id: I9806b624d6e968e51d52aab8c052ae3fa77f247d
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: b4b708e29fbae0d8f5a2cece79711aa6b1887727
Original-Change-Id: I8c168c14437bb932a59ac0e91a01062df0cf11dc
Original-Signed-off-by: Jeffy Chen <jeffy.chen@rock-chips.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/427522
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/18127
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>
This commit is contained in:
Jeffy Chen 2016-12-23 15:05:11 +08:00 committed by Martin Roth
parent 605a87c8eb
commit 9b2fe630d6
1 changed files with 6 additions and 0 deletions

View File

@ -181,6 +181,12 @@ int rtc_get(struct rtc_time *time)
rk808_clrsetbits(RTC_CTRL, RTC_CTRL_GET_TIME, 0);
rk808_clrsetbits(RTC_CTRL, 0, RTC_CTRL_GET_TIME | RTC_CTRL_RTC_READSEL);
/*
* After we set the GET_TIME bit, the rtc time can't be read
* immediately. So we should wait up to 31.25 us.
*/
udelay(32);
ret |= rk808_read(RTC_SECOND, &value);
time->sec = bcd2bin(value & 0x7f);