AM335x Implementing MDIO Bitbang Driver For Clause 45

Hello,

I'm working on a custom board where I have an AM335x with an MDIO/MDC bus connected to a gigabit ethernet phy (Marvell 88E1510) and a 10-gigabit ethernet phy (Marvell 88X2222P). I am using a Buildroot[1] system with Linux kernel 4.6.

The problem is that the AM335x does not support Clause 45 MDIO access[2]. The gigabit device comes up fine as "eth0", however; it seems to be using the CPSW driver.

So I am trying to implement the MDIO Bitbang driver [3] but I can't seem to find much information for how to do this. Including it in the kernel or loading it as a kernel module don't seem to do anything (still only getting eth0).

I am going to look at the MDIO bitbang driver code to see how I'm supposed to use it, but does anyone have any experience/ideas about implementing this kind of driver? Do I still need the Marvell kernel drivers and the bitbang just handles the MDIO transaction or is the bitbang a replacement for the PHY drivers?

Any and all information/pointers are much appreciated.

Thanks,

Thomas

[1] https://buildroot.org/

[2] e2e.ti.com/.../544904

[3] github.com/.../mdio-bitbang.c, but also available in the kernel config under Device Drivers>Network device support>PHY Device support and infrastructure