commit b55847f2a3c973678eecded0ba6fbc6064ee82b4
author Harshit Aghera <haghera@nvidia.com> Tue May 27 14:53:56 2025 +0530
committer Aditya Kurdunkar <akurdunkar@nvidia.com> Wed Jun 18 17:11:51 2025 +0530
tree c46e928fd590e0b5f2b18990ee61cbac4da55e68
parent 128c91da0eccc3c1ea919020183bac37e9754ab3

nvidia-gpu: add voltage sensor

This commit introduces a voltage sensor for the GPU.

Tested: Build an image for gb200nvl-obmc machine with the following
patches cherry picked. This patches are needed to enable the mctp stack.

https://gerrit.openbmc.org/c/openbmc/openbmc/+/79422

```
$ curl -s -k -u 'root:0penBmc' https://10.137.203.137/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/voltage_NVIDIA_GB200_GPU_0_Voltage_0
{
  "@odata.id": "/redfish/v1/Chassis/NVIDIA_GB200_1/Sensors/voltage_NVIDIA_GB200_GPU_0_Voltage_0",
  "@odata.type": "#Sensor.v1_2_0.Sensor",
  "Id": "voltage_NVIDIA_GB200_GPU_0_Voltage_0",
  "Name": "NVIDIA GB200 GPU 0 Voltage 0",
  "Reading": 0.735,
  "ReadingRangeMax": 1.8446744073709552e+16,
  "ReadingRangeMin": 0.0,
  "ReadingType": "Voltage",
  "ReadingUnits": "V",
  "Status": {
    "Health": "OK",
    "State": "Enabled"
  }
}%
```

Change-Id: I3d98f3d7c11221a42460c6f8420c927c1b1711b2
Signed-off-by: Harshit Aghera <haghera@nvidia.com>

src/nvidia-gpu/NvidiaGpuDevice.cpp

diff --git a/src/nvidia-gpu/NvidiaGpuDevice.cpp b/src/nvidia-gpu/NvidiaGpuDevice.cpp
index 5f3e83b..e966d57 100644
--- a/src/nvidia-gpu/NvidiaGpuDevice.cpp
+++ b/src/nvidia-gpu/NvidiaGpuDevice.cpp
@@ -17,6 +17,7 @@
 #include <NvidiaGpuEnergySensor.hpp>
 #include <NvidiaGpuPowerSensor.hpp>
 #include <NvidiaGpuThresholds.hpp>
+#include <NvidiaGpuVoltageSensor.hpp>
 #include <boost/asio/io_context.hpp>
 #include <phosphor-logging/lg2.hpp>
 #include <sdbusplus/asio/connection.hpp>
@@ -83,6 +84,10 @@
         conn, mctpRequester, name + "_Energy_0", path, eid, gpuEnergySensorId,
         objectServer, std::vector<thresholds::Threshold>{});
 
+    voltageSensor = std::make_shared<NvidiaGpuVoltageSensor>(
+        conn, mctpRequester, name + "_Voltage_0", path, eid, gpuVoltageSensorId,
+        objectServer, std::vector<thresholds::Threshold>{});
+
     lg2::info("Added GPU {NAME} Sensors with chassis path: {PATH}.", "NAME",
               name, "PATH", path);
 
@@ -98,6 +103,7 @@
     }
     powerSensor->update();
     energySensor->update();
+    voltageSensor->update();
 
     waitTimer.expires_after(std::chrono::milliseconds(sensorPollMs));
     waitTimer.async_wait([this](const boost::system::error_code& ec) {