1* Microsemi - vsc8531 Giga bit ethernet phy 2 3Required properties: 4- compatible : Should contain phy id as "ethernet-phy-idAAAA.BBBB" 5 The PHY device uses the binding described in 6 Documentation/devicetree/bindings/net/phy.txt 7 8Optional properties: 9- vsc8531,vddmac : The vddmac in mV. 10- vsc8531,edge-slowdown : % the edge should be slowed down relative to 11 the fastest possible edge time. Native sign 12 need not enter. 13 Edge rate sets the drive strength of the MAC 14 interface output signals. Changing the drive 15 strength will affect the edge rate of the output 16 signal. The goal of this setting is to help 17 reduce electrical emission (EMI) by being able 18 to reprogram drive strength and in effect slow 19 down the edge rate if desired. Table 1 shows the 20 impact to the edge rate per VDDMAC supply for each 21 drive strength setting. 22 Ref: Table:1 - Edge rate change below. 23 24Note: see dt-bindings/net/mscc-phy-vsc8531.h for applicable values 25 26Table: 1 - Edge rate change 27----------------------------------------------------------------| 28| Edge Rate Change (VDDMAC) | 29| | 30| 3300 mV 2500 mV 1800 mV 1500 mV | 31|---------------------------------------------------------------| 32| Default Deafult Default Default | 33| (Fastest) (recommended) (recommended) | 34|---------------------------------------------------------------| 35| -2% -3% -5% -6% | 36|---------------------------------------------------------------| 37| -4% -6% -9% -14% | 38|---------------------------------------------------------------| 39| -7% -10% -16% -21% | 40|(recommended) (recommended) | 41|---------------------------------------------------------------| 42| -10% -14% -23% -29% | 43|---------------------------------------------------------------| 44| -17% -23% -35% -42% | 45|---------------------------------------------------------------| 46| -29% -37% -52% -58% | 47|---------------------------------------------------------------| 48| -53% -63% -76% -77% | 49| (slowest) | 50|---------------------------------------------------------------| 51 52Example: 53 54 vsc8531_0: ethernet-phy@0 { 55 compatible = "ethernet-phy-id0007.0570"; 56 vsc8531,vddmac = <3300>; 57 vsc8531,edge-slowdown = <21>; 58 }; 59