[PATCH V3 2/4] dt-bindings: hwmon: ina3221: Add ti,summation-disable

[Jon Hunter <jonathanh@nvidia.com>]

The INA3221 has a critical alert pin that can be controlled by the
summation control function. This function adds the single
shunt-voltage conversions for the desired channels in order to
compare the combined sum to the programmed limit. The Shunt-Voltage
Sum Limit register contains the programmed value that is compared
to the value in the Shunt-Voltage Sum register in order to
determine if the total summed limit is exceeded. If the
shunt-voltage sum limit value is exceeded, the critical alert pin
pulls low.

For the summation limit to have a meaningful value, it is necessary
to use the same shunt-resistor value on all included channels. Add a new
vendor specific property, 'ti,summation-disable', to allow specific
channels to be excluded from the summation control function if the shunt
resistor is different to other channels or the channel should not be
considered for triggering the critical alert pin.

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Ninad Malwade <nmalwade@nvidia.com>
---
 .../devicetree/bindings/hwmon/ti,ina3221.yaml | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml b/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml
index d0e64a72af5b..8afbe729076f 100644
--- a/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml
+++ b/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml
@@ -58,6 +58,25 @@ patternProperties:
       shunt-resistor-micro-ohms:
         description: shunt resistor value in micro-Ohm
 
+      ti,summation-disable:
+        description: |
+          The INA3221 has a critical alert pin that can be controlled by the
+          summation control function. This function adds the single
+          shunt-voltage conversions for the desired channels in order to
+          compare the combined sum to the programmed limit. The Shunt-Voltage
+          Sum Limit register contains the programmed value that is compared
+          to the value in the Shunt-Voltage Sum register in order to
+          determine if the total summed limit is exceeded. If the
+          shunt-voltage sum limit value is exceeded, the critical alert pin
+          is asserted.
+
+          For the summation limit to have a meaningful value, it is necessary
+          to use the same shunt-resistor value on all enabled channels. If
+          this is not the case or if a channel should not be used for
+          triggering the critical alert pin, then this property can be used
+          exclude specific channels from the summation control function.
+        type: boolean
+
     required:
       - reg
 
-- 
2.34.1