[RFC PATCH 2/2] net: stmmac: dwmac-sun8i: Allow runtime AC200/AC300 phy selection

[James Hilliard]

On Mon, May 26, 2025 at 1:58 PM Andrew Lunn <andrew at lunn.ch> wrote:
>
> > I'm currently doing most of the PHY initialization in u-boot to simplify testing
> > of the efuse based PHY selection logic in the kernel. I'm sending this
> > separately as a number of subsequent drivers for kernel side PHY
> > initialization will be dependent upon specific PHY's being discovered at
> > runtime via the ac300 efuse bit.
>
> Do the different PHYs have different ID values in register 2 and 3?

Well...for the primary phy address in the device tree, no:
AC300(does not appear to support address 1 unlike AC200):
PHY at address 0:
0 - 0x3100
1 - 0x79ed
2 - 0x44
3 - 0x1400

AC300 address used for PHY initialization sequence on address 16(0x10),
appears to be used as replacement for i2c init sequence on AC200:
PHY at address 10:
0 - 0x1f80
1 - 0x1084
2 - 0xc000
3 - 0x0

AC200:
PHY at address 0:
0 - 0x3000
1 - 0x79ed
2 - 0x44
3 - 0x1400

AC200:
PHY at address 1:
0 - 0x3000
1 - 0x79ed
2 - 0x44
3 - 0x1400

AC200 appears to support either address 0 or address 1.

>
>         Andrew
>