| * 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"; |
| |
| trigger0 { |
| trigger-name = "external-rising"; |
| trigger-value = <0x1>; |
| trigger-external; |
| }; |
| trigger1 { |
| trigger-name = "external-falling"; |
| trigger-value = <0x2>; |
| trigger-external; |
| }; |
| |
| trigger2 { |
| trigger-name = "external-any"; |
| trigger-value = <0x3>; |
| trigger-external; |
| }; |
| |
| trigger3 { |
| trigger-name = "continuous"; |
| trigger-value = <0x6>; |
| }; |
| }; |