> 1) If I am interested in accessing the PHY Identifier located at Register 2 & 3 of the Marvell PHY, how can I do it?
The section 2.5.2 PHY Register User Access of the SPRUGV9D explains this. In the PHYADR field of the USERACCESS0 register, you need to specify PHY address, and in the REGADR, you can specify the register number 2 or 3.
> 2) If I am interested in configuring the PHY, how can I do it?
I think you need to refer Marvell PHY datasheet.
Regards,
Atsushi