On 26/08/2023 09:56, Krzysztof Kozlowski wrote:
On 25/08/2023 18:42, Ninad Malwade wrote:
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 property, 'summation-bypass', to allow specific channels to be
excluded from the summation control function if the shunt resistor
is different to other channels.
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Ninad Malwade <nmalwade@xxxxxxxxxx>
---
.../devicetree/bindings/hwmon/ti,ina3221.yaml | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml b/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml
index 0c6d41423d8c..20c23febf575 100644
--- a/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml
+++ b/Documentation/devicetree/bindings/hwmon/ti,ina3221.yaml
@@ -55,6 +55,24 @@ patternProperties:
shunt-resistor-micro-ohms:
description: shunt resistor value in micro-Ohm
+ summation-bypass:
What is the type? There is no vendor prefix here, so you added it as a
generic property. Which other devices use or can use it?
+ 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
+ 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. If
+ this is not the case for specific channels, then the
+ 'summation-bypass' can be populated for a specific channel to
+ exclude from the summation control function.
I don't understand what this property does. You described feature in the
device, that's good, but how does it map to the property? Bypass means
disable?
Yes it means 'disable'. I kept as 'bypass' to align with the original
patch [0], but if it is clearer, we could change this to be
'summation-disable'.
Jon
[0] https://lore.kernel.org/lkml/20221108045243.24143-1-nmalwade@xxxxxxxxxx/
--
nvpublic
