For the AD7124 chip the logical irq line (̅R̅D̅Y) is physically on the same
pin as the spi MISO output (DOUT) and so reading a register might
trigger an interrupt. For correct operation it's critical that the
actual state of the pin can be read to judge if an interrupt event is a
real one or just a spurious one triggered by toggling the line in its
MISO mode.
Allow specification of an "rdy-gpios" property that references a GPIO
that can be used for that purpose. While this is typically the same GPIO
also used (implicitly) as interrupt source, it is still supposed that
the interrupt is specified as before and usual.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx>
---
Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
index de49b571bd57..71a40c7ca4bf 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
@@ -37,6 +37,12 @@ properties:
description: IRQ line for the ADC
maxItems: 1
+ rdy-gpios:
+ description: |
+ GPIO reading the ̅R̅D̅Y line. Useful to reliably detect the interrupt
+ condition.
+ maxItems: 1
+
'#address-cells':
const: 1
@@ -112,6 +118,7 @@ unevaluatedProperties: false
examples:
- |
#include <dt-bindings/interrupt-controller/irq.h>
+ #include <dt-bindings/gpio/gpio.h>
spi {
#address-cells = <1>;
#size-cells = <0>;
@@ -122,6 +129,7 @@ examples:
spi-max-frequency = <5000000>;
interrupts = <25 IRQ_TYPE_EDGE_FALLING>;
interrupt-parent = <&gpio>;
+ rdy-gpios = <&gpio 25 GPIO_ACTIVE_LOW>;
refin1-supply = <&adc_vref>;
clocks = <&ad7124_mclk>;
clock-names = "mclk";
--
2.45.2
