Diffstat (limited to 'docs/devel/clocks.rst')
1 files changed, 8 insertions, 1 deletions
diff --git a/docs/devel/clocks.rst b/docs/devel/clocks.rst
index cd344e3fe5..f0391e76b4 100644
@@ -181,7 +181,14 @@ events.
The events currently supported are:
- * ``ClockUpdate`` : called after the input clock's period has changed
+ * ``ClockPreUpdate`` : called when the input clock's period is about to
+ update. This is useful if the device needs to do some action for
+ which it needs to know the old value of the clock period. During
+ this callback, Clock API functions like ``clock_get()`` or
+ ``clock_ticks_to_ns()`` will use the old period.
+ * ``ClockUpdate`` : called after the input clock's period has changed.
+ During this callback, Clock API functions like ``clock_ticks_to_ns()``
+ will use the new period.
Note that a clock only has one callback: it is not possible to register
different functions for different events. You must register a single