On Wed, Sep 10, 2025 at 12:32:21PM +0200, Ivan Vecera wrote:
> The DPLL phase measurement block uses an exponential moving average,
> calculated using the following equation:
>
> 2^N - 1 1
> curr_avg = prev_avg * --------- + new_val * -----
> 2^N 2^N
>
> Where curr_avg is phase offset reported by the firmware to the driver,
> prev_avg is previous averaged value and new_val is currently measured
> value for particular reference.
>
> New measurements are taken approximately 40 Hz or at the frequency of
> the reference (whichever is lower).
>
> The driver currently uses the averaging factor N=2 which prioritizes
> a fast response time to track dynamic changes in the phase. But for
> applications requiring a very stable and precise reading of the average
> phase offset, and where rapid changes are not expected, a higher factor
> would be appropriate.
>
> Add devlink device parameter phase_offset_avg_factor to allow a user
> set tune the averaging factor via devlink interface.
>
> Tested-by: Prathosh Satish <Prathosh.Satish@xxxxxxxxxxxxx>
> Signed-off-by: Ivan Vecera <ivecera@xxxxxxxxxx>
> ---
> Documentation/networking/devlink/zl3073x.rst | 4 ++
> drivers/dpll/zl3073x/core.c | 6 +-
> drivers/dpll/zl3073x/core.h | 8 ++-
> drivers/dpll/zl3073x/devlink.c | 67 ++++++++++++++++++++
> 4 files changed, 82 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/networking/devlink/zl3073x.rst b/Documentation/networking/devlink/zl3073x.rst
> index 4b6cfaf386433..ddd159e39e616 100644
> --- a/Documentation/networking/devlink/zl3073x.rst
> +++ b/Documentation/networking/devlink/zl3073x.rst
> @@ -20,6 +20,10 @@ Parameters
> - driverinit
> - Set the clock ID that is used by the driver for registering DPLL devices
> and pins.
> + * - ``phase_offset_avg_factor``
> + - runtime
> + - Set the factor for the exponential moving average used by DPLL phase
> + measurement block. The value has to be in range <0, 15>.
Maybe put the text in the commit message here as well?
Andrew
