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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>2022-05-23 16:41:12 +0100
commitd02b69049817197034f61ed93aa6135f7c3de6f3 (patch)
treeb383f98fb900a082693b98fd9d17e6ebf370f5f9
parentecc787d936cfc7dafaf675ecac8cfb13410c1134 (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 = {