linux/Documentation/devicetree/bindings/net/micrel-ksz9021.txt
Sean Cross 954c396756 net/phy: micrel: Add OF configuration support for ksz9021
Some boards require custom PHY configuration, for example due to trace
length differences.  Add the ability to configure these registers in
order to get the PHY to function on boards that need it.

Because PHYs are auto-detected based on MDIO device IDs, allow PHY
configuration to be specified in the parent Ethernet device node if no
PHY device node is present.

Signed-off-by: Sean Cross <xobs@kosagi.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-21 00:03:38 -07:00

50 lines
1.4 KiB
Plaintext

Micrel KSZ9021 Gigabit Ethernet PHY
Some boards require special tuning values, particularly when it comes to
clock delays. You can specify clock delay values by adding
micrel-specific properties to an Ethernet OF device node.
All skew control options are specified in picoseconds. The minimum
value is 0, and the maximum value is 3000.
Optional properties:
- rxc-skew-ps : Skew control of RXC pad
- rxdv-skew-ps : Skew control of RX CTL pad
- txc-skew-ps : Skew control of TXC pad
- txen-skew-ps : Skew control of TX_CTL pad
- rxd0-skew-ps : Skew control of RX data 0 pad
- rxd1-skew-ps : Skew control of RX data 1 pad
- rxd2-skew-ps : Skew control of RX data 2 pad
- rxd3-skew-ps : Skew control of RX data 3 pad
- txd0-skew-ps : Skew control of TX data 0 pad
- txd1-skew-ps : Skew control of TX data 1 pad
- txd2-skew-ps : Skew control of TX data 2 pad
- txd3-skew-ps : Skew control of TX data 3 pad
Examples:
/* Attach to an Ethernet device with autodetected PHY */
&enet {
rxc-skew-ps = <3000>;
rxdv-skew-ps = <0>;
txc-skew-ps = <3000>;
txen-skew-ps = <0>;
status = "okay";
};
/* Attach to an explicitly-specified PHY */
mdio {
phy0: ethernet-phy@0 {
rxc-skew-ps = <3000>;
rxdv-skew-ps = <0>;
txc-skew-ps = <3000>;
txen-skew-ps = <0>;
reg = <0>;
};
};
ethernet@70000 {
status = "okay";
phy = <&phy0>;
phy-mode = "rgmii-id";
};