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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>2022-04-02 10:47:57 +0100
commitaf8471ca5584a171c13e6b3e9398a31e59b1cff9 (patch)
tree3a66fc653b05416fd23097268f88610be573bdc7
parent6faf0888c64fb30e495673301087d4905f9e455c (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 = {