[U-Boot] [PATCH 1/2] net: phy: micrel: Use correct skew values on KSZ9021

[Joe Hershberger]

On Mon, Mar 4, 2019 at 11:46 AM James Byrne
<james.byrne at origamienergy.com> wrote:
>
> Commit ff7bd212cb8a ("net: phy: micrel: fix divisor value for KSZ9031
> phy skew") fixed the skew value divisor for the KSZ9031, but left the
> code using the same divisor for the KSZ9021, which is incorrect.
>
> The preceding commit c16e69f702b1 ("net: phy: micrel: add documentation
> for Micrel KSZ90x1 binding") added the DTS documentation for the
> KSZ90x1, changing it from the equivalent file in the Linux kernel to
> correctly state that for this part the skew value is set in 120ps steps,
> whereas the Linux documentation and driver continue to this day to use
> the incorrect value of 200 that came from the original KSZ9021 datasheet
> before it was corrected in revision 1.2 (Feb 2014).
>
> This commit sorts out the resulting confusion in a consistent way by
> making the following changes:
>
> - Update the documentation to be clear about what the skew values mean,
> in the same was as for the KSZ9031.
>
> - Update the Micrel PHY driver to select the appropriate divisor for
> both parts.
>
> - Adjust all the device trees that state skew values for KSZ9021 PHYs to
> use values based on 120ps steps instead of 200ps steps. This will result
> in the same values being programmed into the skew registers as the
> equivalent device trees in the Linux kernel do, where it incorrectly
> uses 200ps steps (since that's where all these device trees were copied
> from).
>
> Signed-off-by: James Byrne <james.byrne at origamienergy.com>

Acked-by: Joe Hershberger <joe.hershberger at ni.com>