AM3358: Configure PHY CLKOUT before PRU FW start

I am working on a custom board based on AM3358 and running Linux RT (sdk-linux-rt-am335x-evm-06.03.00.106)

The hardware design includes 2 PHY where one is sharing REF_CLK with the other via CLKOUT pin.

To enable the CLKOUT pin to share REF_CLK I would expect Linux being able to write PHY registers via PRU-ICSS MDIO bus (pruss_mdio: mdio@4a332400).

&pruss_mdio {
    pinctrl-0 = <&pruss_mdio_default>;
    pinctrl-names = "default";
    status = "okay";

    pruss_eth0_phy: ethernet-phy@2 {
         reg = <2>; /* TJA responds to PHY address 0 */
         reset-gpios = <&gpio1 22 GPIO_ACTIVE_LOW>;
         reset-assert-us = <20>; /* PHY datasheet states 5 uS min - 20 us max */
         reset-deassert-us = <100>; /* Wake-up time */
    };

    pruss_eth1_phy: ethernet-phy@3 {
         reg = <3>;
         reset-gpios = <&gpio2 25 GPIO_ACTIVE_LOW>;
    };
};

My questions are:

1. how can I register a phy fixup for my particular PHY device in order to write the proper register configuration to share CLKOUT (the 2 phy devices have different PHY-IDs from different vendors) ?
2. is the pruss.c driver able to configure PHYs before PRU FW being started ?
3. how to prevent PRU FW to reset PHY devices ?

Thank you in advance

   Andrea