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authorRussell King <rmk+kernel@armlinux.org.uk>2017-09-23 19:27:37 +0100
committerRussell King (Oracle) <rmk+kernel@armlinux.org.uk>2022-01-12 12:14:25 +0000
commitb086d747b534b22d58b35f7fb212f7223e1c243a (patch)
tree36364a0e40232883c94e3edf1bb175ddc547eee0
parent88f1fb932982878873f8605cf99e10e003e638a1 (diff)
rtc: armada38x: provide set_offset_nsec
Armada 388 resets the prescaler when the time register is written, so it requires the current second as close to the start of that second as possible. The data sheet is a bit unclear, so this has been confirmed on real hardware. Verified on Armada 388 based Clearfog. Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
-rw-r--r--drivers/rtc/rtc-armada38x.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-armada38x.c b/drivers/rtc/rtc-armada38x.c
index cc542e6b1d5b..05997ea8fa48 100644
--- a/drivers/rtc/rtc-armada38x.c
+++ b/drivers/rtc/rtc-armada38x.c
@@ -448,6 +448,15 @@ static int armada38x_rtc_set_offset(struct device *dev, long offset)
return 0;
}
+static void armada38x_rtc_pre_register(struct rtc_device *rtc)
+{
+ /*
+ * The Armada 388 resets the prescaler when we write the time.
+ * Validated on clearfog.
+ */
+ rtc->set_offset_nsec = 0;
+}
+
static const struct rtc_class_ops armada38x_rtc_ops = {
.read_time = armada38x_rtc_read_time,
.set_time = armada38x_rtc_set_time,
@@ -456,6 +465,7 @@ static const struct rtc_class_ops armada38x_rtc_ops = {
.alarm_irq_enable = armada38x_rtc_alarm_irq_enable,
.read_offset = armada38x_rtc_read_offset,
.set_offset = armada38x_rtc_set_offset,
+ .pre_register = armada38x_rtc_pre_register,
};
static const struct armada38x_rtc_data armada38x_data = {