Add basebandCn0DbHz to GnssStatus

The new basebandCn0DbHz is the carrier-to-noise density measured at the
baseband. The old Cn0DbHz is measured at the attenna port. Adding
the new field so that ecosystem will report both and avoid reporting
inconsistent signal strengths in one field. See go/r-gnss-hal for
detailed design.

Bug: 136136192

Test: atest GnssStatusTest
Change-Id: Idbfb611c6cb1c8d00c1f3bb719e422177a5ff7f2

3 files changed, 52 insertions, 14 deletions

diff --git a/location/java/android/location/GnssStatus.java b/location/java/android/location/GnssStatus.java
index 2f1eeda9c4cf..89a3bc070578 100644
--- a/location/java/android/location/GnssStatus.java
+++ b/location/java/android/location/GnssStatus.java
@@ -34,7 +34,7 @@ import java.util.ArrayList;
  */
 public final class GnssStatus {
 
-    // these must match the definitions in gps.h
+    // These must match the definitions in GNSS HAL.
     //
     // Note: these constants are also duplicated in GnssStatusCompat.java in the androidx support
     // library. if adding a constellation, please update that file as well.
@@ -63,9 +63,10 @@ public final class GnssStatus {
     private static final int SVID_FLAGS_HAS_ALMANAC_DATA = (1 << 1);
     private static final int SVID_FLAGS_USED_IN_FIX = (1 << 2);
     private static final int SVID_FLAGS_HAS_CARRIER_FREQUENCY = (1 << 3);
+    private static final int SVID_FLAGS_HAS_BASEBAND_CN0 = (1 << 4);
 
-    private static final int SVID_SHIFT_WIDTH = 8;
-    private static final int CONSTELLATION_TYPE_SHIFT_WIDTH = 4;
+    private static final int SVID_SHIFT_WIDTH = 12;
+    private static final int CONSTELLATION_TYPE_SHIFT_WIDTH = 8;
     private static final int CONSTELLATION_TYPE_MASK = 0xf;
 
     /**
@@ -123,9 +124,10 @@ public final class GnssStatus {
      */
     @NonNull
     public static GnssStatus wrap(int svCount, int[] svidWithFlags, float[] cn0DbHzs,
-            float[] elevations, float[] azimuths, float[] carrierFrequencies) {
+            float[] elevations, float[] azimuths, float[] carrierFrequencies,
+            float[] basebandCn0DbHzs) {
         return new GnssStatus(svCount, svidWithFlags, cn0DbHzs, elevations, azimuths,
-                carrierFrequencies);
+                carrierFrequencies, basebandCn0DbHzs);
     }
 
     private final int mSvCount;
@@ -134,15 +136,17 @@ public final class GnssStatus {
     private final float[] mElevations;
     private final float[] mAzimuths;
     private final float[] mCarrierFrequencies;
+    private final float[] mBasebandCn0DbHzs;
 
     private GnssStatus(int svCount, int[] svidWithFlags, float[] cn0DbHzs, float[] elevations,
-            float[] azimuths, float[] carrierFrequencies) {
+            float[] azimuths, float[] carrierFrequencies, float[] basebandCn0DbHzs) {
         mSvCount = svCount;
         mSvidWithFlags = svidWithFlags;
         mCn0DbHzs = cn0DbHzs;
         mElevations = elevations;
         mAzimuths = azimuths;
         mCarrierFrequencies = carrierFrequencies;
+        mBasebandCn0DbHzs = basebandCn0DbHzs;
     }
 
     /**
@@ -284,6 +288,26 @@ public final class GnssStatus {
     }
 
     /**
+     * Reports whether a valid {@link #getBasebandCn0DbHz(int satelliteIndex)} is available.
+     *
+     * @param satelliteIndex An index from zero to {@link #getSatelliteCount()} - 1
+     */
+    public boolean hasBasebandCn0DbHz(@IntRange(from = 0) int satelliteIndex) {
+        return (mSvidWithFlags[satelliteIndex] & SVID_FLAGS_HAS_BASEBAND_CN0) != 0;
+    }
+
+    /**
+     * Retrieves the baseband carrier-to-noise density of the satellite at the specified index in
+     * dB-Hz.
+     *
+     * @param satelliteIndex An index from zero to {@link #getSatelliteCount()} - 1
+     */
+    @FloatRange(from = 0, to = 63)
+    public float getBasebandCn0DbHz(@IntRange(from = 0) int satelliteIndex) {
+        return mBasebandCn0DbHzs[satelliteIndex];
+    }
+
+    /**
      * Returns the string representation of a constellation type.
      *
      * @param constellationType the constellation type.
@@ -334,6 +358,8 @@ public final class GnssStatus {
          * @param usedInFix whether the satellite was used in the most recent location fix
          * @param hasCarrierFrequency whether carrier frequency data is available
          * @param carrierFrequency satellite carrier frequency in Hz
+         * @param hasBasebandCn0DbHz whether baseband carrier-to-noise density is available
+         * @param basebandCn0DbHz baseband carrier-to-noise density in dB-Hz
          */
         @NonNull
         public Builder addSatellite(@ConstellationType int constellationType,
@@ -345,9 +371,12 @@ public final class GnssStatus {
                 boolean hasAlmanac,
                 boolean usedInFix,
                 boolean hasCarrierFrequency,
-                @FloatRange(from = 0) float carrierFrequency) {
+                @FloatRange(from = 0) float carrierFrequency,
+                boolean hasBasebandCn0DbHz,
+                @FloatRange(from = 0, to = 63) float basebandCn0DbHz) {
             mSatellites.add(new GnssSvInfo(constellationType, svid, cn0DbHz, elevation, azimuth,
-                    hasEphemeris, hasAlmanac, usedInFix, hasCarrierFrequency, carrierFrequency));
+                    hasEphemeris, hasAlmanac, usedInFix, hasCarrierFrequency, carrierFrequency,
+                    hasBasebandCn0DbHz, basebandCn0DbHz));
             return this;
         }
 
@@ -371,6 +400,7 @@ public final class GnssStatus {
             float[] elevations = new float[svCount];
             float[] azimuths = new float[svCount];
             float[] carrierFrequencies = new float[svCount];
+            float[] basebandCn0DbHzs = new float[svCount];
 
             for (int i = 0; i < svidWithFlags.length; i++) {
                 svidWithFlags[i] = mSatellites.get(i).mSvidWithFlags;
@@ -387,9 +417,12 @@ public final class GnssStatus {
             for (int i = 0; i < carrierFrequencies.length; i++) {
                 carrierFrequencies[i] = mSatellites.get(i).mCarrierFrequency;
             }
+            for (int i = 0; i < basebandCn0DbHzs.length; i++) {
+                basebandCn0DbHzs[i] = mSatellites.get(i).mBasebandCn0DbHz;
+            }
 
             return wrap(svCount, svidWithFlags, cn0DbHzs, elevations, azimuths,
-                    carrierFrequencies);
+                    carrierFrequencies, basebandCn0DbHzs);
         }
     }
 
@@ -400,21 +433,25 @@ public final class GnssStatus {
         private final float mElevation;
         private final float mAzimuth;
         private final float mCarrierFrequency;
+        private final float mBasebandCn0DbHz;
 
         private GnssSvInfo(int constellationType, int svid, float cn0DbHz,
                 float elevation, float azimuth, boolean hasEphemeris, boolean hasAlmanac,
-                boolean usedInFix, boolean hasCarrierFrequency, float carrierFrequency) {
+                boolean usedInFix, boolean hasCarrierFrequency, float carrierFrequency,
+                boolean hasBasebandCn0DbHz, float basebandCn0DbHz) {
             mSvidWithFlags = (svid << SVID_SHIFT_WIDTH)
                     | ((constellationType & CONSTELLATION_TYPE_MASK)
                     << CONSTELLATION_TYPE_SHIFT_WIDTH)
                     | (hasEphemeris ? SVID_FLAGS_HAS_EPHEMERIS_DATA : SVID_FLAGS_NONE)
                     | (hasAlmanac ? SVID_FLAGS_HAS_ALMANAC_DATA : SVID_FLAGS_NONE)
                     | (usedInFix ? SVID_FLAGS_USED_IN_FIX : SVID_FLAGS_NONE)
-                    | (hasCarrierFrequency ? SVID_FLAGS_HAS_CARRIER_FREQUENCY : SVID_FLAGS_NONE);
+                    | (hasCarrierFrequency ? SVID_FLAGS_HAS_CARRIER_FREQUENCY : SVID_FLAGS_NONE)
+                    | (hasBasebandCn0DbHz ? SVID_FLAGS_HAS_BASEBAND_CN0 : SVID_FLAGS_NONE);
             mCn0DbHz = cn0DbHz;
             mElevation = elevation;
             mAzimuth = azimuth;
             mCarrierFrequency = carrierFrequency;
+            mBasebandCn0DbHz = basebandCn0DbHz;
         }
     }
 }
diff --git a/location/java/android/location/IGnssStatusListener.aidl b/location/java/android/location/IGnssStatusListener.aidl
index d824cb18765a..1931a005d66f 100644
--- a/location/java/android/location/IGnssStatusListener.aidl
+++ b/location/java/android/location/IGnssStatusListener.aidl
@@ -28,6 +28,6 @@ oneway interface IGnssStatusListener
     void onFirstFix(int ttff);
     void onSvStatusChanged(int svCount, in int[] svidWithFlags, in float[] cn0s,
             in float[] elevations, in float[] azimuths,
-            in float[] carrierFreqs);
+            in float[] carrierFreqs, in float[] basebandCn0s);
     void onNmeaReceived(long timestamp, String nmea);
 }
diff --git a/location/java/android/location/LocationManager.java b/location/java/android/location/LocationManager.java
index 75e1cd45689c..c0041722c475 100644
--- a/location/java/android/location/LocationManager.java
+++ b/location/java/android/location/LocationManager.java
@@ -2818,9 +2818,10 @@ public class LocationManager {
 
             @Override
             public void onSvStatusChanged(int svCount, int[] svidWithFlags, float[] cn0s,
-                    float[] elevations, float[] azimuths, float[] carrierFreqs) {
+                    float[] elevations, float[] azimuths, float[] carrierFreqs,
+                    float[] basebandCn0s) {
                 GnssStatus localStatus = GnssStatus.wrap(svCount, svidWithFlags, cn0s,
-                        elevations, azimuths, carrierFreqs);
+                        elevations, azimuths, carrierFreqs, basebandCn0s);
                 mGnssStatus = localStatus;
                 execute((callback) -> callback.onSatelliteStatusChanged(localStatus));
             }