In addition to GPIO synchronization, The AD7768-1 also supports
synchronization over SPI, which use is recommended when the GPIO
cannot provide a pulse synchronous with the base MCLK signal. It
consists of looping back the SYNC_OUT to the SYNC_IN pin and send
a command via SPI to trigger the synchronization.
Introduce the 'trigger-sources' property to enable SPI-based
synchronization via SYNC_OUT pin, along with additional optional
entries for GPIO3 and DRDY pins.
Also create #trigger-source-cells property to differentiate the trigger
sources provided by the ADC. To improve readability, create a
adi,ad7768-1.h header with the macros for the cell values.
While at it, add description to the interrupts property.
Reviewed-by: David Lechner <dlechner@baylirbe.com>
Signed-off-by: Jonathan Santos <Jonathan.Santos@analog.com>
---
v7 Changes:
* added new file to the MAINTAINERS entry.
* Made interrupts description more concise.
* Added dependencies to constrain the use of trigger-sources and
adi,sync-in-gpios properties at the same time.
v6 Changes:
* Removed references to offload.
* Changed trigger-sources-cells description. Each cell value indicates
a gpio line from the ADC.
* Added adi,ad7768-1.h header with macros for the trigger source cells.
* Removed offload trigger entry from trigger-sources.
v5 Changes:
* Include START pin and DRDY in the trigger-sources description.
* Fixed "#trigger-source-cells" value and description.
* sync-in-gpios is represented in the trigger-sources property.
v4 Changes:
* none
v3 Changes:
* Fixed dt-bindings errors.
* Trigger-source is set as an alternative to sync-in-gpios, so we
don't break the previous ABI.
* increased maxItems from trigger-sources to 2.
v2 Changes:
* Patch added as replacement for adi,sync-in-spi patch.
* addressed the request for a description to interrupts property.
---
.../bindings/iio/adc/adi,ad7768-1.yaml | 39 ++++++++++++++++++-
MAINTAINERS | 1 +
include/dt-bindings/iio/adc/adi,ad7768-1.h | 10 +++++
3 files changed, 49 insertions(+), 1 deletion(-)
create mode 100644 include/dt-bindings/iio/adc/adi,ad7768-1.h
diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
index 3ce59d4d065f..9a6df931edc3 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
@@ -26,7 +26,26 @@ properties:
clock-names:
const: mclk
+ trigger-sources:
+ $ref: /schemas/types.yaml#/definitions/phandle-array
+ minItems: 1
+ maxItems: 2
+ description: |
+ A list of phandles referencing trigger source providers. Each entry
+ represents a trigger source for the ADC:
+
+ - First entry specifies the device responsible for driving the
+ synchronization (SYNC_IN) pin, as an alternative to adi,sync-in-gpios.
+ This can be a `gpio-trigger` or another `ad7768-1` device. If the
+ device's own SYNC_OUT pin is internally connected to its SYNC_IN pin,
+ reference the device itself or omit this property.
+ - Second entry optionally defines a GPIO3 pin used as a START signal trigger.
+
+ Use the accompanying trigger source cell to identify the type of each entry.
+
interrupts:
+ description:
+ DRDY (Data Ready) pin, which signals conversion results are available.
maxItems: 1
'#address-cells':
@@ -57,6 +76,15 @@ properties:
"#io-channel-cells":
const: 1
+ "#trigger-source-cells":
+ description: |
+ Cell indicates the trigger output signal: 0 = SYNC_OUT, 1 = GPIO3,
+ 2 = DRDY.
+
+ For better readability, macros for these values are available in
+ dt-bindings/iio/adc/adi,ad7768-1.h.
+ const: 1
+
required:
- compatible
- reg
@@ -65,7 +93,16 @@ required:
- vref-supply
- spi-cpol
- spi-cpha
- - adi,sync-in-gpios
+
+dependencies:
+ adi,sync-in-gpios:
+ not:
+ required:
+ - trigger-sources
+ trigger-sources:
+ not:
+ required:
+ - adi,sync-in-gpios
patternProperties:
"^channel@([0-9]|1[0-5])$":
diff --git a/MAINTAINERS b/MAINTAINERS
index 9b2e9a9dd8bc..be07926f6666 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1426,6 +1426,7 @@ S: Supported
W: https://ez.analog.com/linux-software-drivers
F: Documentation/devicetree/bindings/iio/adc/adi,ad7768-1.yaml
F: drivers/iio/adc/ad7768-1.c
+F: include/dt-bindings/iio/adc/adi,ad7768-1.h
ANALOG DEVICES INC AD7780 DRIVER
M: Michael Hennerich <Michael.Hennerich@analog.com>
diff --git a/include/dt-bindings/iio/adc/adi,ad7768-1.h b/include/dt-bindings/iio/adc/adi,ad7768-1.h
new file mode 100644
index 000000000000..34d92856a50b
--- /dev/null
+++ b/include/dt-bindings/iio/adc/adi,ad7768-1.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+
+#ifndef _DT_BINDINGS_ADI_AD7768_1_H
+#define _DT_BINDINGS_ADI_AD7768_1_H
+
+#define AD7768_TRIGGER_SOURCE_SYNC_OUT 0
+#define AD7768_TRIGGER_SOURCE_GPIO3 1
+#define AD7768_TRIGGER_SOURCE_DRDY 2
+
+#endif /* _DT_BINDINGS_ADI_AD7768_1_H */
--
2.34.1