Commit ff7bd212cb ("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 c16e69f702 ("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@origamienergy.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
Add the DTS documentation for the Micrel KSZ90x1 binding.
The original document was from:
[commit 4b405efbe12de28b26289282b431323d73992381 from the Linux kernel]
This takes the original document and adds a clarification on how the skew
values are represented in the code.
References:
Micrel ksz9021rl/rn Data Sheet, Revision 1.2. Dated 2/13/2014.
http://www.micrel.com/_PDF/Ethernet/datasheets/ksz9021rl-rn_ds.pdf
Micrel ksz9031rnx Data Sheet, Revision 2.1. Dated 11/20/2014.
http://www.micrel.com/_PDF/Ethernet/datasheets/KSZ9031RNX.pdf
Signed-off-by: Dinh Nguyen <dinguyen@opensource.altera.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
