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Hi all, I have an embedded Analogue & Micro Adder/875 (PowerPC 875) board which (compared to the default evaluation board "config.") has been slightly modified to contain a Broadcom BCM5221 ...
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  1. #1
    Just Joined!
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    Jun 2012
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    2

    Broadcom BCM5221


    Hi all,

    I have an embedded Analogue & Micro Adder/875 (PowerPC 875) board which (compared to the default evaluation board "config.") has been slightly modified to contain a Broadcom BCM5221 ethernet circuit.

    I currently have the following MII PHY device drivers kernel configuration running on my board (based on the default adder875 config.):
    #
    # MII PHY device drivers
    #
    # CONFIG_MARVELL_PHY is not set
    CONFIG_DAVICOM_PHY=y
    # CONFIG_QSEMI_PHY is not set
    # CONFIG_LXT_PHY is not set
    # CONFIG_CICADA_PHY is not set
    # CONFIG_VITESSE_PHY is not set
    # CONFIG_SMSC_PHY is not set
    # CONFIG_BROADCOM_PHY is not set
    # CONFIG_ICPLUS_PHY is not set
    # CONFIG_REALTEK_PHY is not set
    # CONFIG_NATIONAL_PHY is not set
    # CONFIG_STE10XP is not set
    # CONFIG_LSI_ET1011C_PHY is not set
    # CONFIG_MICREL_PHY is not set
    # CONFIG_FIXED_PHY is not set
    # CONFIG_MDIO_BITBANG is not set
    CONFIG_NET_ETHERNET=y
    CONFIG_MII=y
    # CONFIG_ETHOC is not set
    # CONFIG_DNET is not set
    # CONFIG_IBM_NEW_EMAC_ZMII is not set
    # CONFIG_IBM_NEW_EMAC_RGMII is not set
    # CONFIG_IBM_NEW_EMAC_TAH is not set
    # CONFIG_IBM_NEW_EMAC_EMAC4 is not set
    # CONFIG_IBM_NEW_EMAC_NO_FLOW_CTRL is not set
    # CONFIG_IBM_NEW_EMAC_MAL_CLR_ICINTSTAT is not set
    # CONFIG_IBM_NEW_EMAC_MAL_COMMON_ERR is not set
    # CONFIG_B44 is not set
    # CONFIG_KS8842 is not set
    # CONFIG_KS8851_MLL is not set
    # CONFIG_XILINX_EMACLITE is not set
    CONFIG_FS_ENET=y
    # CONFIG_FS_ENET_HAS_SCC is not set
    CONFIG_FS_ENET_HAS_FEC=y
    CONFIG_FS_ENET_MDIO_FEC=y
    # CONFIG_NETDEV_1000 is not set
    # CONFIG_NETDEV_10000 is not set
    CONFIG_WLAN=y
    # CONFIG_HOSTAP is not set

    As you can see - I do not (for instance) have the CONFIG_BROADCOM_PHY active. My intention (hope?) was that the generic ethernet support should take care of the BCM5221 circuit.

    An extract from my DTS file also:
    ....
    mdio<at>e00 {
    compatible = "fsl,mpc875-fec-mdio", "fsl,pq1-fec-mdio";
    reg = <0xe00 0x188>;
    #address-cells = <1>;
    #size-cells = <0>;

    PHY0: ethernet-phy<at>0 {
    reg = <0>;
    device_type = "ethernet-phy";
    };

    PHY1: ethernet-phy<at>1 {
    reg = <1>;
    device_type = "ethernet-phy";
    };
    };

    eth0: ethernet<at>e00 {
    device_type = "network";
    compatible = "fsl,mpc875-fec-enet",
    "fsl,pq1-fec-enet";
    reg = <0xe00 0x188>;
    local-mac-address = [ 00 00 00 00 00 00 ];
    interrupts = <3 1>;
    interrupt-parent = <&PIC>;
    phy-handle = <&PHY0>;
    linux,network-index = <0>;
    };

    eth1: ethernet<at>1e00 {
    device_type = "network";
    compatible = "fsl,mpc875-fec-enet",
    "fsl,pq1-fec-enet";
    reg = <0x1e00 0x188>;
    local-mac-address = [ 00 00 00 00 00 00 ];
    interrupts = <7 1>;
    interrupt-parent = <&PIC>;
    phy-handle = <&PHY1>;
    linux,network-index = <1>;
    };
    .....

    The problem which I observe during board power-up is as follows:
    <boot'ing.......>
    Finalizing device tree... flat tree at 0x572300
    mdio_bus fa200e00: error probing PHY at address 1 <---- issue

    ......

    net eth1: Could not attach to PHY <---- issue following (caused by e.g. ifup)

    --------

    I have had successful boot-up's of the board too (where this issue is not seen) but I can't say what parameter affects this (ethernet cable in/out, timing, etc.). The point is that this is unstable and unpredictible.

    I am running Redboot as boot loader, but with ethernet support deactivated at compile-time so I guess Redboot is not doing any circuit init. or reset.

    So - do any of you clever guys out there have any suggestions on what can cause this issue, and how to fix it such that both ethernet i/f are successfully initialized and working?

    Your help is appreciated.

    Regards, Eldor

  2. #2
    Just Joined!
    Join Date
    Jun 2012
    Posts
    2
    Hi all!

    It appears that this issue is solved by performing a reset of the ethernet PB28 pin of the PPC.
    The unstable behaviour is believed to be caused by an unstable level - sometimes causing
    a low PB28, and sometimes not.

    Regards, Eldor

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