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Diffstat (limited to 'Documentation/devicetree/bindings/iio/adc/at91_adc.txt')
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diff --git a/Documentation/devicetree/bindings/iio/adc/at91_adc.txt b/Documentation/devicetree/bindings/iio/adc/at91_adc.txt new file mode 100644 index 000000000000..0f813dec5e08 --- /dev/null +++ b/Documentation/devicetree/bindings/iio/adc/at91_adc.txt @@ -0,0 +1,87 @@ +* AT91's Analog to Digital Converter (ADC) + +Required properties: + - compatible: Should be "atmel,<chip>-adc" + <chip> can be "at91sam9260", "at91sam9g45" or "at91sam9x5" + - reg: Should contain ADC registers location and length + - interrupts: Should contain the IRQ line for the ADC + - clock-names: tuple listing input clock names. + Required elements: "adc_clk", "adc_op_clk". + - clocks: phandles to input clocks. + - atmel,adc-channels-used: Bitmask of the channels muxed and enabled for this + device + - atmel,adc-startup-time: Startup Time of the ADC in microseconds as + defined in the datasheet + - atmel,adc-vref: Reference voltage in millivolts for the conversions + - atmel,adc-res: List of resolutions in bits supported by the ADC. List size + must be two at least. + - atmel,adc-res-names: Contains one identifier string for each resolution + in atmel,adc-res property. "lowres" and "highres" + identifiers are required. + +Optional properties: + - atmel,adc-use-external-triggers: Boolean to enable the external triggers + - atmel,adc-use-res: String corresponding to an identifier from + atmel,adc-res-names property. If not specified, the highest + resolution will be used. + - atmel,adc-sleep-mode: Boolean to enable sleep mode when no conversion + - atmel,adc-sample-hold-time: Sample and Hold Time in microseconds + - atmel,adc-ts-wires: Number of touchscreen wires. Should be 4 or 5. If this + value is set, then the adc driver will enable touchscreen + support. + NOTE: when adc touchscreen is enabled, the adc hardware trigger will be + disabled. Since touchscreen will occupy the trigger register. + - atmel,adc-ts-pressure-threshold: a pressure threshold for touchscreen. It + makes touch detection more precise. + +Optional trigger Nodes: + - Required properties: + * trigger-name: Name of the trigger exposed to the user + * trigger-value: Value to put in the Trigger register + to activate this trigger + - Optional properties: + * trigger-external: Is the trigger an external trigger? + +Examples: +adc0: adc@fffb0000 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "atmel,at91sam9260-adc"; + reg = <0xfffb0000 0x100>; + interrupts = <20 IRQ_TYPE_LEVEL_HIGH 0>; + clocks = <&adc_clk>, <&adc_op_clk>; + clock-names = "adc_clk", "adc_op_clk"; + atmel,adc-channels-used = <0xff>; + atmel,adc-startup-time = <40>; + atmel,adc-use-external-triggers; + atmel,adc-vref = <3300>; + atmel,adc-res = <8 10>; + atmel,adc-res-names = "lowres", "highres"; + atmel,adc-use-res = "lowres"; + + trigger@0 { + reg = <0>; + trigger-name = "external-rising"; + trigger-value = <0x1>; + trigger-external; + }; + trigger@1 { + reg = <1>; + trigger-name = "external-falling"; + trigger-value = <0x2>; + trigger-external; + }; + + trigger@2 { + reg = <2>; + trigger-name = "external-any"; + trigger-value = <0x3>; + trigger-external; + }; + + trigger@3 { + reg = <3>; + trigger-name = "continuous"; + trigger-value = <0x6>; + }; +}; |