1Micrel KSZ9021/KSZ9031 Gigabit Ethernet PHY 2 3Some boards require special tuning values, particularly when it comes 4to clock delays. You can specify clock delay values in the PHY OF 5device node. Deprecated, but still supported, these properties can 6also be added to an Ethernet OF device node. 7 8Note that these settings are applied after any phy-specific fixup from 9phy_fixup_list (see phy_init_hw() from drivers/net/phy/phy_device.c), 10and therefore may overwrite them. 11 12KSZ9021: 13 14 All skew control options are specified in picoseconds. The minimum 15 value is 0, the maximum value is 3000, and it is incremented by 200ps 16 steps. 17 18 Optional properties: 19 20 - rxc-skew-ps : Skew control of RXC pad 21 - rxdv-skew-ps : Skew control of RX CTL pad 22 - txc-skew-ps : Skew control of TXC pad 23 - txen-skew-ps : Skew control of TX CTL pad 24 - rxd0-skew-ps : Skew control of RX data 0 pad 25 - rxd1-skew-ps : Skew control of RX data 1 pad 26 - rxd2-skew-ps : Skew control of RX data 2 pad 27 - rxd3-skew-ps : Skew control of RX data 3 pad 28 - txd0-skew-ps : Skew control of TX data 0 pad 29 - txd1-skew-ps : Skew control of TX data 1 pad 30 - txd2-skew-ps : Skew control of TX data 2 pad 31 - txd3-skew-ps : Skew control of TX data 3 pad 32 33KSZ9031: 34 35 All skew control options are specified in picoseconds. The minimum 36 value is 0, and the maximum is property-dependent. The increment 37 step is 60ps. The default value is the neutral setting, so setting 38 rxc-skew-ps=<0> actually results in -900 picoseconds adjustment. 39 40 Optional properties: 41 42 Maximum value of 1860, default value 900: 43 44 - rxc-skew-ps : Skew control of RX clock pad 45 - txc-skew-ps : Skew control of TX clock pad 46 47 Maximum value of 900, default value 420: 48 49 - rxdv-skew-ps : Skew control of RX CTL pad 50 - txen-skew-ps : Skew control of TX CTL pad 51 - rxd0-skew-ps : Skew control of RX data 0 pad 52 - rxd1-skew-ps : Skew control of RX data 1 pad 53 - rxd2-skew-ps : Skew control of RX data 2 pad 54 - rxd3-skew-ps : Skew control of RX data 3 pad 55 - txd0-skew-ps : Skew control of TX data 0 pad 56 - txd1-skew-ps : Skew control of TX data 1 pad 57 - txd2-skew-ps : Skew control of TX data 2 pad 58 - txd3-skew-ps : Skew control of TX data 3 pad 59 60Examples: 61 62 mdio { 63 phy0: ethernet-phy@0 { 64 rxc-skew-ps = <3000>; 65 rxdv-skew-ps = <0>; 66 txc-skew-ps = <3000>; 67 txen-skew-ps = <0>; 68 reg = <0>; 69 }; 70 }; 71 ethernet@70000 { 72 status = "okay"; 73 phy = <&phy0>; 74 phy-mode = "rgmii-id"; 75 }; 76