Ethernet issue with KSZ9021

[khaleel]

Hello Team,

We have designed a custom board with imx8m mini  in which we have selected KSZ9021 as PHY . 

PHY configuration

phy addr : 0

LED Mode : Tricolour Dual LED

125MHZ CLK DISABLE

RGMII mode - Advertise all capabilities
(10/100/1000 speed half-/full-duplex)

Kernel device tree support :

CONFIG_MICREL_PHY=y

&fec1 {
     pinctrl-names = "default";
     pinctrl-0 = <&pinctrl_fec1>;
     phy-mode = "rgmii-id";
     phy-handle = <&ethphy0>;
     phy-reset-gpios = <&gpio3 16 GPIO_ACTIVE_LOW>;
     phy-reset-post-delay = <150>;
     phy-reset-duration = <10>;
     fsl,magic-packet;
     status = "okay";

     mdio {
            #address-cells = <1>;
             #size-cells = <0>;

             ethphy0: ethernet-phy@0 {
                       compatible = "ethernet-phy-ieee802.3-c22";
                       reg = <0>;
             };
      };
};

 With this configuration PHY is detecting and i'm getting eth0 node in rootfilesystem.

Issue : When i try to assign an ip with dhclient, it unable to get an ip. Tried assigning ip manually but unable to ping dns or google.

ethtool output : Phy has been detected successfully

root@imx8mmpds:~# ethtool eth0
Settings for eth0:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                1000baseT/Full 
        Supported pause frame use: Symmetric
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                1000baseT/Full 
        Advertised pause frame use: Symmetric
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Link partner advertised link modes:  10baseT/Half 10baseT/Full 
                                             100baseT/Half 100baseT/Full 
        Link partner advertised pause frame use: Symmetric
        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 100Mb/s
        Duplex: Full
        Port: MII
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: g
        Wake-on: d
        Link detected: yes

query's :

1) Is my device tree looks fine ?

2) Any driver modifications or fix ups required for KSZ9021 to work?

Best Regards

khaleel

[weidong_sun]

Hi,

I have ever used ksz9031 for i.MX8MM, see attachment, please! 

In addition, if you used 3.3V IO between CPU and ksz9021, you should disable pull-up/down feature of ENET pads. If pull-up/down resistors are needed, external pull should be used.

for disabling ENET pin's pull up/down, re-configure these pins , please!

---------------------------------

MX8MM_IOMUXC_ENET_MDC_ENET1_MDC 0x3
MX8MM_IOMUXC_ENET_MDIO_ENET1_MDIO 0x3
MX8MM_IOMUXC_ENET_TD3_ENET1_RGMII_TD3 0x1f
MX8MM_IOMUXC_ENET_TD2_ENET1_RGMII_TD2 0x1f
MX8MM_IOMUXC_ENET_TD1_ENET1_RGMII_TD1 0x1f
MX8MM_IOMUXC_ENET_TD0_ENET1_RGMII_TD0 0x1f
MX8MM_IOMUXC_ENET_RD3_ENET1_RGMII_RD3 0x91
MX8MM_IOMUXC_ENET_RD2_ENET1_RGMII_RD2 0x91
MX8MM_IOMUXC_ENET_RD1_ENET1_RGMII_RD1 0x91
MX8MM_IOMUXC_ENET_RD0_ENET1_RGMII_RD0 0x91
MX8MM_IOMUXC_ENET_TXC_ENET1_RGMII_TXC 0x1f
MX8MM_IOMUXC_ENET_RXC_ENET1_RGMII_RXC 0x91
MX8MM_IOMUXC_ENET_RX_CTL_ENET1_RGMII_RX_CTL 0x91
MX8MM_IOMUXC_ENET_TX_CTL_ENET1_RGMII_TX_CTL 0x1f
MX8MM_IOMUXC_GPIO1_IO07_GPIO1_IO7 0x19

-----------------------------------------------

For 1.8V IO, default configurations are OK, don't need to re-configure them.

Have a nice day!

Regards,

weidong

[khaleel]

Hi weidong,

Thank you for the reply.

KSZ9021 supports only 3.3V/2.5V, In our custom board we are using 2.5V as IO voltage.

Do i still need to reconfigure ENET pads?

Best regards

khaleel