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Diffstat (limited to 'Documentation/devicetree/bindings/net/gpmc-eth.txt')
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diff --git a/Documentation/devicetree/bindings/net/gpmc-eth.txt b/Documentation/devicetree/bindings/net/gpmc-eth.txt new file mode 100644 index 000000000..f7da3d73c --- /dev/null +++ b/Documentation/devicetree/bindings/net/gpmc-eth.txt @@ -0,0 +1,97 @@ +Device tree bindings for Ethernet chip connected to TI GPMC + +Besides being used to interface with external memory devices, the +General-Purpose Memory Controller can be used to connect Pseudo-SRAM devices +such as ethernet controllers to processors using the TI GPMC as a data bus. + +Ethernet controllers connected to TI GPMC are represented as child nodes of +the GPMC controller with an "ethernet" name. + +All timing relevant properties as well as generic GPMC child properties are +explained in a separate documents. Please refer to +Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt + +For the properties relevant to the ethernet controller connected to the GPMC +refer to the binding documentation of the device. For example, the documentation +for the SMSC 911x is Documentation/devicetree/bindings/net/smsc911x.txt + +Child nodes need to specify the GPMC bus address width using the "bank-width" +property but is possible that an ethernet controller also has a property to +specify the I/O registers address width. Even when the GPMC has a maximum 16-bit +address width, it supports devices with 32-bit word registers. +For example with an SMSC LAN911x/912x controller connected to the TI GPMC on an +OMAP2+ board, "bank-width = <2>;" and "reg-io-width = <4>;". + +Required properties: +- bank-width: Address width of the device in bytes. GPMC supports 8-bit + and 16-bit devices and so must be either 1 or 2 bytes. +- compatible: Compatible string property for the ethernet child device. +- gpmc,cs-on-ns: Chip-select assertion time +- gpmc,cs-rd-off-ns: Chip-select de-assertion time for reads +- gpmc,cs-wr-off-ns: Chip-select de-assertion time for writes +- gpmc,oe-on-ns: Output-enable assertion time +- gpmc,oe-off-ns: Output-enable de-assertion time +- gpmc,we-on-ns: Write-enable assertion time +- gpmc,we-off-ns: Write-enable de-assertion time +- gpmc,access-ns: Start cycle to first data capture (read access) +- gpmc,rd-cycle-ns: Total read cycle time +- gpmc,wr-cycle-ns: Total write cycle time +- reg: Chip-select, base address (relative to chip-select) + and size of the memory mapped for the device. + Note that base address will be typically 0 as this + is the start of the chip-select. + +Optional properties: +- gpmc,XXX Additional GPMC timings and settings parameters. See + Documentation/devicetree/bindings/memory-controllers/omap-gpmc.txt + +Example: + +gpmc: gpmc@6e000000 { + compatible = "ti,omap3430-gpmc"; + ti,hwmods = "gpmc"; + reg = <0x6e000000 0x1000>; + interrupts = <20>; + gpmc,num-cs = <8>; + gpmc,num-waitpins = <4>; + #address-cells = <2>; + #size-cells = <1>; + + ranges = <5 0 0x2c000000 0x1000000>; + + ethernet@5,0 { + compatible = "smsc,lan9221", "smsc,lan9115"; + reg = <5 0 0xff>; + bank-width = <2>; + + gpmc,mux-add-data; + gpmc,cs-on-ns = <0>; + gpmc,cs-rd-off-ns = <186>; + gpmc,cs-wr-off-ns = <186>; + gpmc,adv-on-ns = <12>; + gpmc,adv-rd-off-ns = <48>; + gpmc,adv-wr-off-ns = <48>; + gpmc,oe-on-ns = <54>; + gpmc,oe-off-ns = <168>; + gpmc,we-on-ns = <54>; + gpmc,we-off-ns = <168>; + gpmc,rd-cycle-ns = <186>; + gpmc,wr-cycle-ns = <186>; + gpmc,access-ns = <114>; + gpmc,page-burst-access-ns = <6>; + gpmc,bus-turnaround-ns = <12>; + gpmc,cycle2cycle-delay-ns = <18>; + gpmc,wr-data-mux-bus-ns = <90>; + gpmc,wr-access-ns = <186>; + gpmc,cycle2cycle-samecsen; + gpmc,cycle2cycle-diffcsen; + + interrupt-parent = <&gpio6>; + interrupts = <16>; + vmmc-supply = <&vddvario>; + vmmc_aux-supply = <&vdd33a>; + reg-io-width = <4>; + + smsc,save-mac-address; + }; +}; |