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Diffstat (limited to 'Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt')
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diff --git a/Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt b/Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt new file mode 100644 index 000000000..df5b9f2ad --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/renesas,gyroadc.txt @@ -0,0 +1,98 @@ +* Renesas R-Car GyroADC device driver + +The GyroADC block is a reduced SPI block with up to 8 chipselect lines, +which supports the SPI protocol of a selected few SPI ADCs. The SPI ADCs +are sampled by the GyroADC block in a round-robin fashion and the result +presented in the GyroADC registers. + +Required properties: +- compatible: Should be "<soc-specific>", "renesas,rcar-gyroadc". + The <soc-specific> should be one of: + renesas,r8a7791-gyroadc - for the GyroADC block present + in r8a7791 SoC + renesas,r8a7792-gyroadc - for the GyroADC with interrupt + block present in r8a7792 SoC +- reg: Address and length of the register set for the device +- clocks: References to all the clocks specified in the clock-names + property as specified in + Documentation/devicetree/bindings/clock/clock-bindings.txt. +- clock-names: Shall contain "fck". The "fck" is the GyroADC block clock. +- power-domains: Must contain a reference to the PM domain, if available. +- #address-cells: Should be <1> (setting for the subnodes) for all ADCs + except for "fujitsu,mb88101a". Should be <0> (setting for + only subnode) for "fujitsu,mb88101a". +- #size-cells: Should be <0> (setting for the subnodes) + +Sub-nodes: +You must define subnode(s) which select the connected ADC type and reference +voltage for the GyroADC channels. + +Required properties for subnodes: +- compatible: Should be either of: + "fujitsu,mb88101a" + - Fujitsu MB88101A compatible mode, + 12bit sampling, up to 4 channels can be sampled in + round-robin fashion. One Fujitsu chip supplies four + GyroADC channels with data as it contains four ADCs + on the chip and thus for 4-channel operation, single + MB88101A is required. The Cx chipselect lines of the + MB88101A connect directly to two CHS lines of the + GyroADC, no demuxer is required. The data out line + of each MB88101A connects to a shared input pin of + the GyroADC. + "ti,adcs7476" or "ti,adc121" or "adi,ad7476" + - TI ADCS7476 / TI ADC121 / ADI AD7476 compatible mode, + 15bit sampling, up to 8 channels can be sampled in + round-robin fashion. One TI/ADI chip supplies single + ADC channel with data, thus for 8-channel operation, + 8 chips are required. A 3:8 chipselect demuxer is + required to connect the nCS line of the TI/ADI chips + to the GyroADC, while MISO line of each TI/ADI ADC + connects to a shared input pin of the GyroADC. + "maxim,max1162" or "maxim,max11100" + - Maxim MAX1162 / Maxim MAX11100 compatible mode, + 16bit sampling, up to 8 channels can be sampled in + round-robin fashion. One Maxim chip supplies single + ADC channel with data, thus for 8-channel operation, + 8 chips are required. A 3:8 chipselect demuxer is + required to connect the nCS line of the MAX chips + to the GyroADC, while MISO line of each Maxim ADC + connects to a shared input pin of the GyroADC. +- reg: Should be the number of the analog input. Should be present + for all ADCs except "fujitsu,mb88101a". +- vref-supply: Reference to the channel reference voltage regulator. + +Example: + vref_max1162: regulator-vref-max1162 { + compatible = "regulator-fixed"; + + regulator-name = "MAX1162 Vref"; + regulator-min-microvolt = <4096000>; + regulator-max-microvolt = <4096000>; + }; + + adc@e6e54000 { + compatible = "renesas,r8a7791-gyroadc", "renesas,rcar-gyroadc"; + reg = <0 0xe6e54000 0 64>; + clocks = <&mstp9_clks R8A7791_CLK_GYROADC>; + clock-names = "fck"; + power-domains = <&sysc R8A7791_PD_ALWAYS_ON>; + + pinctrl-0 = <&adc_pins>; + pinctrl-names = "default"; + + #address-cells = <1>; + #size-cells = <0>; + + adc@0 { + reg = <0>; + compatible = "maxim,max1162"; + vref-supply = <&vref_max1162>; + }; + + adc@1 { + reg = <1>; + compatible = "maxim,max1162"; + vref-supply = <&vref_max1162>; + }; + }; |