forked from Minki/linux
6cc2ff8249
Add support for an MDIO bus multiplexer controlled by a simple memory-mapped device, like an FPGA. The device must be memory-mapped and contain only 8-bit registers (which keeps things simple). Tested on a Freescale P5020DS board which uses the "PIXIS" FPGA attached to the localbus. Signed-off-by: Timur Tabi <timur@freescale.com> Signed-off-by: David S. Miller <davem@davemloft.net>
76 lines
2.1 KiB
Plaintext
76 lines
2.1 KiB
Plaintext
Properties for an MDIO bus multiplexer controlled by a memory-mapped device
|
|
|
|
This is a special case of a MDIO bus multiplexer. A memory-mapped device,
|
|
like an FPGA, is used to control which child bus is connected. The mdio-mux
|
|
node must be a child of the memory-mapped device. The driver currently only
|
|
supports devices with eight-bit registers.
|
|
|
|
Required properties in addition to the generic multiplexer properties:
|
|
|
|
- compatible : string, must contain "mdio-mux-mmioreg"
|
|
|
|
- reg : integer, contains the offset of the register that controls the bus
|
|
multiplexer. The size field in the 'reg' property is the size of
|
|
register, and must therefore be 1.
|
|
|
|
- mux-mask : integer, contains an eight-bit mask that specifies which
|
|
bits in the register control the actual bus multiplexer. The
|
|
'reg' property of each child mdio-mux node must be constrained by
|
|
this mask.
|
|
|
|
Example:
|
|
|
|
The FPGA node defines a memory-mapped FPGA with a register space of 0x30 bytes.
|
|
For the "EMI2" MDIO bus, register 9 (BRDCFG1) controls the mux on that bus.
|
|
A bitmask of 0x6 means that bits 1 and 2 (bit 0 is lsb) are the bits on
|
|
BRDCFG1 that control the actual mux.
|
|
|
|
/* The FPGA node */
|
|
fpga: board-control@3,0 {
|
|
#address-cells = <1>;
|
|
#size-cells = <1>;
|
|
compatible = "fsl,p5020ds-fpga", "fsl,fpga-ngpixis";
|
|
reg = <3 0 0x30>;
|
|
ranges = <0 3 0 0x30>;
|
|
|
|
mdio-mux-emi2 {
|
|
compatible = "mdio-mux-mmioreg", "mdio-mux";
|
|
mdio-parent-bus = <&xmdio0>;
|
|
#address-cells = <1>;
|
|
#size-cells = <0>;
|
|
reg = <9 1>; // BRDCFG1
|
|
mux-mask = <0x6>; // EMI2
|
|
|
|
emi2_slot1: mdio@0 { // Slot 1 XAUI (FM2)
|
|
reg = <0>;
|
|
#address-cells = <1>;
|
|
#size-cells = <0>;
|
|
|
|
phy_xgmii_slot1: ethernet-phy@0 {
|
|
compatible = "ethernet-phy-ieee802.3-c45";
|
|
reg = <4>;
|
|
};
|
|
};
|
|
|
|
emi2_slot2: mdio@2 { // Slot 2 XAUI (FM1)
|
|
reg = <2>;
|
|
#address-cells = <1>;
|
|
#size-cells = <0>;
|
|
|
|
phy_xgmii_slot2: ethernet-phy@4 {
|
|
compatible = "ethernet-phy-ieee802.3-c45";
|
|
reg = <0>;
|
|
};
|
|
};
|
|
};
|
|
};
|
|
|
|
/* The parent MDIO bus. */
|
|
xmdio0: mdio@f1000 {
|
|
#address-cells = <1>;
|
|
#size-cells = <0>;
|
|
compatible = "fsl,fman-xmdio";
|
|
reg = <0xf1000 0x1000>;
|
|
interrupts = <100 1 0 0>;
|
|
};
|