summaryrefslogtreecommitdiff
path: root/Documentation/devicetree/bindings/iio/adc/at91_adc.txt
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/devicetree/bindings/iio/adc/at91_adc.txt')
-rw-r--r--Documentation/devicetree/bindings/iio/adc/at91_adc.txt87
1 files changed, 87 insertions, 0 deletions
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>;
+ };
+};