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-rw-r--r-- | Documentation/devicetree/bindings/iio/adc/xilinx-xadc.txt | 113 |
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diff --git a/Documentation/devicetree/bindings/iio/adc/xilinx-xadc.txt b/Documentation/devicetree/bindings/iio/adc/xilinx-xadc.txt new file mode 100644 index 0000000..d9ee909 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/xilinx-xadc.txt @@ -0,0 +1,113 @@ +Xilinx XADC device driver + +This binding document describes the bindings for both of them since the +bindings are very similar. The Xilinx XADC is a ADC that can be found in the +series 7 FPGAs from Xilinx. The XADC has a DRP interface for communication. +Currently two different frontends for the DRP interface exist. One that is only +available on the ZYNQ family as a hardmacro in the SoC portion of the ZYNQ. The +other one is available on all series 7 platforms and is a softmacro with a AXI +interface. This binding document describes the bindings for both of them since +the bindings are very similar. + +Required properties: + - compatible: Should be one of + * "xlnx,zynq-xadc-1.00.a": When using the ZYNQ device + configuration interface to interface to the XADC hardmacro. + * "xlnx,axi-xadc-1.00.a": When using the axi-xadc pcore to + interface to the XADC hardmacro. + - reg: Address and length of the register set for the device + - interrupts: Interrupt for the XADC control interface. + - clocks: When using the ZYNQ this must be the ZYNQ PCAP clock, + when using the AXI-XADC pcore this must be the clock that provides the + clock to the AXI bus interface of the core. + +Optional properties: + - interrupt-parent: phandle to the parent interrupt controller + - xlnx,external-mux: + * "none": No external multiplexer is used, this is the default + if the property is omitted. + * "single": External multiplexer mode is used with one + multiplexer. + * "dual": External multiplexer mode is used with two + multiplexers for simultaneous sampling. + - xlnx,external-mux-channel: Configures which pair of pins is used to + sample data in external mux mode. + Valid values for single external multiplexer mode are: + 0: VP/VN + 1: VAUXP[0]/VAUXN[0] + 2: VAUXP[1]/VAUXN[1] + ... + 16: VAUXP[15]/VAUXN[15] + Valid values for dual external multiplexer mode are: + 1: VAUXP[0]/VAUXN[0] - VAUXP[8]/VAUXN[8] + 2: VAUXP[1]/VAUXN[1] - VAUXP[9]/VAUXN[9] + ... + 8: VAUXP[7]/VAUXN[7] - VAUXP[15]/VAUXN[15] + + This property needs to be present if the device is configured for + external multiplexer mode (either single or dual). If the device is + not using external multiplexer mode the property is ignored. + - xnlx,channels: List of external channels that are connected to the ADC + Required properties: + * #address-cells: Should be 1. + * #size-cells: Should be 0. + + The child nodes of this node represent the external channels which are + connected to the ADC. If the property is no present no external + channels will be assumed to be connected. + + Each child node represents one channel and has the following + properties: + Required properties: + * reg: Pair of pins the the channel is connected to. + 0: VP/VN + 1: VAUXP[0]/VAUXN[0] + 2: VAUXP[1]/VAUXN[1] + ... + 16: VAUXP[15]/VAUXN[15] + Note each channel number should only be used at most + once. + Optional properties: + * xlnx,bipolar: If set the channel is used in bipolar + mode. + + +Examples: + xadc@f8007100 { + compatible = "xlnx,zynq-xadc-1.00.a"; + reg = <0xf8007100 0x20>; + interrupts = <0 7 4>; + interrupt-parent = <&gic>; + clocks = <&pcap_clk>; + + xlnx,channels { + #address-cells = <1>; + #size-cells = <0>; + channel@0 { + reg = <0>; + }; + channel@1 { + reg = <1>; + }; + channel@8 { + reg = <8>; + }; + }; + }; + + xadc@43200000 { + compatible = "xlnx,axi-xadc-1.00.a"; + reg = <0x43200000 0x1000>; + interrupts = <0 53 4>; + interrupt-parent = <&gic>; + clocks = <&fpga1_clk>; + + xlnx,channels { + #address-cells = <1>; + #size-cells = <0>; + channel@0 { + reg = <0>; + xlnx,bipolar; + }; + }; + }; |