Re: AM335x ICE board Linux support

[Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>]

* Roger Quadros <rogerq-l0cyMroinI0@public.gmane.org> [160429 03:10]:
> On 26/04/16 18:10, Tony Lindgren wrote:
> > I guess for now if no runtime detection is possible in the kernel.
> 
> There are 2 ways to detect them mode
> 1) Enabe GPIO rising edge detect interrupt and reset the Ethernet PHY
> 2) read a PHY register over MDIO bus
> 
> I'm not very sure where this can be done in the kernel.

We already have some PHY detection over MDIO detection in place,
so that's probably the most generic solution.

> Even if there is some place to do the detection, how do we go about reconfiguring the
> device tree?

You may not need to, you can have several named pin states:

pinctrl-names = "default", "phy-foo", "phy-bar";
pinctrl-0 = <&cpsw_default>;
pinctrl-1 = <&cpsw_phy_foo>;
pinctrl-2 = <&cpsw_phy_bar>;
...

Then have the common pins in cpsw_default, and manually enable
the other pinctrl groups based on the detection. We already
have that going on in am335x-bone-common.dtsi with the &mac
entry for cpsw.

But maybe you have other detection issues too beyond setting
the pins?

Regards,

Tony
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