blob: 99c7eb0a00c8f3d07542284e1df4af094d158aee (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
|
* 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>;
};
|
