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| author | Joshua Clayton <stillcompiling@gmail.com> | 2016-02-05 21:41:11 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2016-03-14 17:08:15 +0100 |
| commit | b3967067c273359c7462f4be9a887c3d1a515f49 (patch) | |
| tree | 1f2ca90d34dae4961b97d68ccdb93a979ee5e2b8 /Documentation/arm64 | |
| parent | rtc: rv8803: convert spin_lock to mutex_lock (diff) | |
| download | linux-b3967067c273359c7462f4be9a887c3d1a515f49.tar.xz linux-b3967067c273359c7462f4be9a887c3d1a515f49.zip | |
rtc: Add functions to set and read rtc offset
A number of rtc devices, such as the NXP pcf2123 include a facility
to adjust the clock in order to compensate for temperature or a
crystal, capacitor, etc, that results in the rtc clock not running
at exactly 32.768 kHz.
Data sheets I have seen refer to this as a clock offset, and measure it
in parts per million, however they often reference ppm to 2 digits of
precision, which makes integer ppm less than ideal.
We use parts per billion, which more than covers the precision needed
and works nicely within 32 bits
Signed-off-by: Joshua Clayton <stillcompiling@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'Documentation/arm64')
0 files changed, 0 insertions, 0 deletions