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authorJeffy Chen <jeffy.chen@rock-chips.com>2016-12-23 15:05:11 +0800
committerMartin Roth <martinroth@google.com>2017-01-13 17:40:56 +0100
commit9b2fe630d6a7144558224e4e5dfcc22d19b47a02 (patch)
tree879e8e66e29248f25eec62435f245d8b739b5f45 /src/soc
parent605a87c8eb8672375f2a58191fe7ba8ebc83c42a (diff)
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>
Diffstat (limited to 'src/soc')
-rw-r--r--src/soc/rockchip/common/rk808.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/src/soc/rockchip/common/rk808.c b/src/soc/rockchip/common/rk808.c
index dc6b2ea23f..a68b838f48 100644
--- a/src/soc/rockchip/common/rk808.c
+++ b/src/soc/rockchip/common/rk808.c
@@ -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);