59 lines
2.2 KiB
Plaintext
59 lines
2.2 KiB
Plaintext
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* Microsemi - vsc8531 Giga bit ethernet phy
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Required properties:
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- compatible : Should contain phy id as "ethernet-phy-idAAAA.BBBB"
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The PHY device uses the binding described in
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Documentation/devicetree/bindings/net/phy.txt
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Optional properties:
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- vsc8531,vddmac : The vddmac in mV.
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- vsc8531,edge-slowdown : % the edge should be slowed down relative to
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the fastest possible edge time. Native sign
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need not enter.
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Edge rate sets the drive strength of the MAC
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interface output signals. Changing the drive
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strength will affect the edge rate of the output
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signal. The goal of this setting is to help
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reduce electrical emission (EMI) by being able
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to reprogram drive strength and in effect slow
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down the edge rate if desired. Table 1 shows the
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impact to the edge rate per VDDMAC supply for each
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drive strength setting.
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Ref: Table:1 - Edge rate change below.
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Note: see dt-bindings/net/mscc-phy-vsc8531.h for applicable values
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Table: 1 - Edge rate change
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----------------------------------------------------------------|
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| Edge Rate Change (VDDMAC) |
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| 3300 mV 2500 mV 1800 mV 1500 mV |
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|---------------------------------------------------------------|
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| Default Deafult Default Default |
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| (Fastest) (recommended) (recommended) |
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|---------------------------------------------------------------|
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| -2% -3% -5% -6% |
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|---------------------------------------------------------------|
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| -4% -6% -9% -14% |
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|---------------------------------------------------------------|
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| -7% -10% -16% -21% |
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|(recommended) (recommended) |
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|---------------------------------------------------------------|
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| -10% -14% -23% -29% |
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|---------------------------------------------------------------|
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| -17% -23% -35% -42% |
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|---------------------------------------------------------------|
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| -29% -37% -52% -58% |
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|---------------------------------------------------------------|
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| -53% -63% -76% -77% |
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| (slowest) |
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|---------------------------------------------------------------|
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Example:
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vsc8531_0: ethernet-phy@0 {
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compatible = "ethernet-phy-id0007.0570";
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vsc8531,vddmac = <3300>;
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vsc8531,edge-slowdown = <21>;
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};
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