Broadcom BCM5221

[eldorr]

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

[eldorr]

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