From e4341623a3b87e7eca87d42b7b88da967cd21c49 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 19 Feb 2021 14:45:35 +0000 Subject: clock: Add ClockPreUpdate callback event type Add a new callback event type ClockPreUpdate, which is called on period changes before the period is updated. Signed-off-by: Peter Maydell Reviewed-by: Luc Michel Reviewed-by: Hao Wu Reviewed-by: Philippe Mathieu-Daudé Tested-by: Philippe Mathieu-Daudé Message-id: 20210219144617.4782-3-peter.maydell@linaro.org --- docs/devel/clocks.rst | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'docs') diff --git a/docs/devel/clocks.rst b/docs/devel/clocks.rst index cd344e3fe5..f0391e76b4 100644 --- a/docs/devel/clocks.rst +++ b/docs/devel/clocks.rst @@ -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 -- cgit v1.2.3-55-g7522