e1000_null_read_reg
phy->ops.read_reg = e1000_null_read_reg;
phy->ops.read_reg_locked = e1000_null_read_reg;
phy->ops.read_reg_page = e1000_null_read_reg;
s32 e1000_null_read_reg(struct e1000_hw *hw, u32 offset, u16 *data);