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