[wpilib, hal] Add function to read the RSL state (#5312)

hal/src/main/java/edu/wpi/first/hal/HAL.java

@@ -117,6 +117,8 @@ public final class HAL extends JNIWrapper {
 
   public static native boolean getSystemActive();
 
+  public static native boolean getRSLState();
+
   public static native int getPortWithModule(byte module, byte channel);
 
   public static native int getPort(byte channel);

hal/src/main/native/athena/HAL.cpp

@@ -423,6 +423,15 @@ HAL_Bool HAL_GetBrownedOut(int32_t* status) {
   return !(watchdog->readStatus_PowerAlive(status));
 }
 
+HAL_Bool HAL_GetRSLState(int32_t* status) {
+  hal::init::CheckInit();
+  if (!global) {
+    *status = NiFpga_Status_ResourceNotInitialized;
+    return false;
+  }
+  return global->readLEDs_RSL(status);
+}
+
 static bool killExistingProgram(int timeout, int mode) {
   // Kill any previous robot programs
   std::fstream fs;

hal/src/main/native/cpp/jni/HAL.cpp

@@ -136,6 +136,21 @@ Java_edu_wpi_first_hal_HAL_getBrownedOut
   return val;
 }
 
+/*
+ * Class:     edu_wpi_first_hal_HAL
+ * Method:    getRSLState
+ * Signature: ()Z
+ */
+JNIEXPORT jboolean JNICALL
+Java_edu_wpi_first_hal_HAL_getRSLState
+  (JNIEnv* env, jclass)
+{
+  int32_t status = 0;
+  bool val = HAL_GetRSLState(&status);
+  CheckStatus(env, status);
+  return val;
+}
+
 /*
  * Class:     edu_wpi_first_hal_HAL
  * Method:    getPortWithModule

hal/src/main/native/include/hal/HALBase.h

@@ -172,6 +172,13 @@ uint64_t HAL_GetFPGATime(int32_t* status);
  */
 uint64_t HAL_ExpandFPGATime(uint32_t unexpandedLower, int32_t* status);
 
+/**
+ * Gets the current state of the Robot Signal Light (RSL)
+ * @param[out] status the error code, or 0 for success
+ * @return The current state of the RSL- true if on, false if off
+ */
+HAL_Bool HAL_GetRSLState(int32_t* status);
+
 /**
  * Call this to start up HAL. This is required for robot programs.
  *

hal/src/main/native/sim/HAL.cpp

@@ -328,6 +328,10 @@ HAL_Bool HAL_GetBrownedOut(int32_t* status) {
   return false;  // Figure out if we need to detect a brownout condition
 }
 
+HAL_Bool HAL_GetRSLState(int32_t* status) {
+  return false;
+}
+
 HAL_Bool HAL_Initialize(int32_t timeout, int32_t mode) {
   static std::atomic_bool initialized{false};
   static wpi::mutex initializeMutex;

wpilibc/src/main/native/cpp/RobotController.cpp

@@ -76,6 +76,13 @@ bool RobotController::IsBrownedOut() {
   return retVal;
 }
 
+bool RobotController::GetRSLState() {
+  int32_t status = 0;
+  bool retVal = HAL_GetRSLState(&status);
+  FRC_CheckErrorStatus(status, "GetRSLState");
+  return retVal;
+}
+
 double RobotController::GetInputVoltage() {
   int32_t status = 0;
   double retVal = HAL_GetVinVoltage(&status);

wpilibc/src/main/native/include/frc/RobotController.h

@@ -101,6 +101,12 @@ class RobotController {
    */
   static bool IsBrownedOut();
 
+  /**
+   * Gets the current state of the Robot Signal Light (RSL)
+   * @return The current state of the RSL- true if on, false if off
+   */
+  static bool GetRSLState();
+
   /**
    * Get the input voltage to the robot controller.
    *

wpilibj/src/main/java/edu/wpi/first/wpilibj/RobotController.java

@@ -103,6 +103,15 @@ public final class RobotController {
     return HAL.getBrownedOut();
   }
 
+  /**
+   * Gets the current state of the Robot Signal Light (RSL).
+   *
+   * @return The current state of the RSL- true if on, false if off
+   */
+  public static boolean getRSLState() {
+    return HAL.getRSLState();
+  }
+
   /**
    * Get the input voltage to the robot controller.
    *