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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /Documentation/devicetree/bindings/net/mdio-mux-mmioreg.txt | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | Documentation/devicetree/bindings/net/mdio-mux-mmioreg.txt | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/net/mdio-mux-mmioreg.txt b/Documentation/devicetree/bindings/net/mdio-mux-mmioreg.txt new file mode 100644 index 000000000..065e8bdb9 --- /dev/null +++ b/Documentation/devicetree/bindings/net/mdio-mux-mmioreg.txt @@ -0,0 +1,75 @@ +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 8, 16 or 32-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, 2, or 4. + +- 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>; + }; |