On Tue, Oct 31, 2017 at 09:19:07AM +0100, Corentin Labbe wrote:

Hello

The current way to find if the PHY is internal is to compare DT phy-mode
and emac_variant/internal_phy.
But it will negate a possible future SoC where an external PHY use the
same phy mode than the integrated one.

This patchs series adds a new way to handle this problem via a mdio-mux.

The first try was to create a new MDIO mux "mdio-mux-syscon".
mdio-mux-syscon working the same way than mdio-mux-mmioreg with the exception
that the register is used via syscon/regmap.
But this solution does not work for two reason:
- changing the MDIO selection need the reset of MAC which cannot be done by the
        mdio-mux-syscon driver
- There were driver loading order problem:
        - mdio-mux-syscon needing that stmmac register the parent MDIO
        - stmmac needing that child MDIO was registered just after registering parent MDIO

So we cannot use any external MDIO-mux.

The final solution was to represent the mdio-mux in MAC node and let
the MAC handle all things.

Since DT bits was reverted in 4.13, this patch series include the
revert of the revert.

I have let patch splited for easy review. (for seeing what's new)
But the final serie could have some patch squashed if someone want.
Like squashing patch and 1 and 2 (documentation)

Applied the patches, and I'll send a PR for it tomorrow after one
linux-next run.

Hopefully it will be merged in time for 4.15.

Thanks for your persistence,
Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20171031/65777a98/attachment.sig>