sensor: Add function to support sensor with readingAssertion type

readingAssertion is special type where the entire assert bitfield
serves as the value or reading.

Change-Id: Iaddbe846e04d2a53cff69d71670a96ccc66636a8
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>

2 files changed, 48 insertions, 0 deletions

diff --git a/sensordatahandler.hpp b/sensordatahandler.hpp
index 010772d..ba496e7 100644
--- a/sensordatahandler.hpp
+++ b/sensordatahandler.hpp
@@ -1,6 +1,8 @@
 #pragma once
 
+#include "sensorhandler.h"
 #include "types.hpp"
+#include "utils.hpp"
 #include "host-ipmid/ipmid-api.h"
 
 namespace ipmi
@@ -81,6 +83,38 @@ GetSensorResponse assertion(const Info& sensorInfo);
  */
 GetSensorResponse eventdata2(const Info& sensorInfo);
 
+/**
+ *  @brief readingAssertion is a case where the entire assertion state field
+ *         serves as the sensor value.
+ *
+ *  @tparam T - type of the dbus property related to sensor.
+ *  @param[in] sensorInfo - Dbus info related to sensor.
+ *
+ *  @return Response for get sensor reading command.
+ */
+template<typename T>
+GetSensorResponse readingAssertion(const Info& sensorInfo)
+{
+    sdbusplus::bus::bus bus{ipmid_get_sd_bus_connection()};
+    GetSensorResponse response {};
+    auto responseData = reinterpret_cast<GetReadingResponse*>(response.data());
+
+    auto service = ipmi::getService(bus,
+                                    sensorInfo.sensorInterface,
+                                    sensorInfo.sensorPath);
+
+    auto propValue = ipmi::getDbusProperty(
+            bus,
+            service,
+            sensorInfo.sensorPath,
+            sensorInfo.propertyInterfaces.begin()->first,
+            sensorInfo.propertyInterfaces.begin()->second.begin()->first);
+
+    setAssertionBytes(static_cast<uint16_t>(propValue.get<T>()), responseData);
+
+    return response;
+}
+
 } //namespace get
 
 namespace set
diff --git a/sensorhandler.h b/sensorhandler.h
index a078693..6ba5c34 100644
--- a/sensorhandler.h
+++ b/sensorhandler.h
@@ -510,6 +510,20 @@ inline void setReading(uint8_t value, ipmi::sensor::GetReadingResponse* resp)
     resp->reading = value;
 }
 
+/**
+ * @brief Map the value to the assertion bytes. The assertion states are stored
+ *        in 2 bytes.
+ *
+ * @param[in] value - value to mapped to the assertion byte.
+ * @param[in/out] resp - get sensor reading response.
+ */
+inline void setAssertionBytes(uint16_t value,
+                              ipmi::sensor::GetReadingResponse* resp)
+{
+    resp->assertOffset0_7 = static_cast<uint8_t>(value & 0x00FF);
+    resp->assertOffset8_14 = static_cast<uint8_t>(value >> 8);
+}
+
 } // namespace sensor
 
 } // namespace ipmi