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authorJoshua Clayton <stillcompiling@gmail.com>2016-02-05 12:41:12 -0800
committerAlexandre Belloni <alexandre.belloni@free-electrons.com>2016-03-14 17:08:16 +0100
commit5495a4159f7413f0367e8c9727ba9facd40ade7f (patch)
tree5bfdec7f3b6982a2c29c89762e8a20a50e579918 /Documentation/rtc.txt
parentb3967067c273359c7462f4be9a887c3d1a515f49 (diff)
rtc: implement a sysfs interface for clock offset
clock offset may be set and read in decimal parts per billion attribute is /sys/class/rtc/rtcN/offset The attribute is only visible for rtcs that have set_offset implemented. Signed-off-by: Joshua Clayton <stillcompiling@gmail.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'Documentation/rtc.txt')
-rw-r--r--Documentation/rtc.txt6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/rtc.txt b/Documentation/rtc.txt
index 8446f1ea1410..ddc366026e00 100644
--- a/Documentation/rtc.txt
+++ b/Documentation/rtc.txt
@@ -157,6 +157,12 @@ wakealarm: The time at which the clock will generate a system wakeup
the epoch by default, or if there's a leading +, seconds in the
future, or if there is a leading +=, seconds ahead of the current
alarm.
+offset: The amount which the rtc clock has been adjusted in firmware.
+ Visible only if the driver supports clock offset adjustment.
+ The unit is parts per billion, i.e. The number of clock ticks
+ which are added to or removed from the rtc's base clock per
+ billion ticks. A positive value makes a day pass more slowly,
+ longer, and a negative value makes a day pass more quickly.
IOCTL INTERFACE
---------------