84 lines
2.9 KiB
Plaintext
84 lines
2.9 KiB
Plaintext
* 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>;
|
|
};
|
|
};
|