[hal] Add frequency support to DutyCycle (#8076)

wpilibc/src/main/native/cpp/DutyCycle.cpp

@@ -35,18 +35,11 @@ void DutyCycle::InitDutyCycle() {
   wpi::SendableRegistry::Add(this, "Duty Cycle", m_channel);
 }
 
-int DutyCycle::GetFPGAIndex() const {
-  int32_t status = 0;
-  auto retVal = HAL_GetDutyCycleFPGAIndex(m_handle, &status);
-  FRC_CheckErrorStatus(status, "Channel {}", GetSourceChannel());
-  return retVal;
-}
-
-int DutyCycle::GetFrequency() const {
+units::hertz_t DutyCycle::GetFrequency() const {
   int32_t status = 0;
   auto retVal = HAL_GetDutyCycleFrequency(m_handle, &status);
   FRC_CheckErrorStatus(status, "Channel {}", GetSourceChannel());
-  return retVal;
+  return units::hertz_t{retVal};
 }
 
 double DutyCycle::GetOutput() const {
@@ -63,13 +56,6 @@ units::second_t DutyCycle::GetHighTime() const {
   return units::nanosecond_t{static_cast<double>(retVal)};
 }
 
-unsigned int DutyCycle::GetOutputScaleFactor() const {
-  int32_t status = 0;
-  auto retVal = HAL_GetDutyCycleOutputScaleFactor(m_handle, &status);
-  FRC_CheckErrorStatus(status, "Channel {}", GetSourceChannel());
-  return retVal;
-}
-
 int DutyCycle::GetSourceChannel() const {
   return m_channel;
 }
@@ -77,7 +63,7 @@ int DutyCycle::GetSourceChannel() const {
 void DutyCycle::InitSendable(wpi::SendableBuilder& builder) {
   builder.SetSmartDashboardType("Duty Cycle");
   builder.AddDoubleProperty(
-      "Frequency", [this] { return this->GetFrequency(); }, nullptr);
+      "Frequency", [this] { return this->GetFrequency().value(); }, nullptr);
   builder.AddDoubleProperty(
       "Output", [this] { return this->GetOutput(); }, nullptr);
 }

wpilibc/src/main/native/cpp/DutyCycleEncoder.cpp

@@ -122,7 +122,7 @@ void DutyCycleEncoder::SetDutyCycleRange(double min, double max) {
   m_sensorMax = std::clamp(max, 0.0, 1.0);
 }
 
-int DutyCycleEncoder::GetFrequency() const {
+units::hertz_t DutyCycleEncoder::GetFrequency() const {
   return m_dutyCycle->GetFrequency();
 }
 
@@ -133,9 +133,10 @@ bool DutyCycleEncoder::IsConnected() const {
   return GetFrequency() > m_frequencyThreshold;
 }
 
-void DutyCycleEncoder::SetConnectedFrequencyThreshold(int frequency) {
-  if (frequency < 0) {
-    frequency = 0;
+void DutyCycleEncoder::SetConnectedFrequencyThreshold(
+    units::hertz_t frequency) {
+  if (frequency < 0_Hz) {
+    frequency = 0_Hz;
   }
   m_frequencyThreshold = frequency;
 }
@@ -152,10 +153,6 @@ void DutyCycleEncoder::SetAssumedFrequency(units::hertz_t frequency) {
   }
 }
 
-int DutyCycleEncoder::GetFPGAIndex() const {
-  return m_dutyCycle->GetFPGAIndex();
-}
-
 int DutyCycleEncoder::GetSourceChannel() const {
   return m_dutyCycle->GetSourceChannel();
 }

wpilibc/src/main/native/cpp/simulation/DutyCycleSim.cpp

@@ -15,18 +15,10 @@ using namespace frc;
 using namespace frc::sim;
 
 DutyCycleSim::DutyCycleSim(const DutyCycle& dutyCycle)
-    : m_index{dutyCycle.GetFPGAIndex()} {}
+    : m_index{dutyCycle.GetSourceChannel()} {}
 
 DutyCycleSim DutyCycleSim::CreateForChannel(int channel) {
-  int index = HALSIM_FindDutyCycleForChannel(channel);
-  if (index < 0) {
-    throw std::out_of_range("no duty cycle found for channel");
-  }
-  return DutyCycleSim{index};
-}
-
-DutyCycleSim DutyCycleSim::CreateForIndex(int index) {
-  return DutyCycleSim{index};
+  return DutyCycleSim{channel};
 }
 
 std::unique_ptr<CallbackStore> DutyCycleSim::RegisterInitializedCallback(
@@ -55,12 +47,12 @@ std::unique_ptr<CallbackStore> DutyCycleSim::RegisterFrequencyCallback(
   return store;
 }
 
-int DutyCycleSim::GetFrequency() const {
-  return HALSIM_GetDutyCycleFrequency(m_index);
+units::hertz_t DutyCycleSim::GetFrequency() const {
+  return units::hertz_t{HALSIM_GetDutyCycleFrequency(m_index)};
 }
 
-void DutyCycleSim::SetFrequency(int frequency) {
-  HALSIM_SetDutyCycleFrequency(m_index, frequency);
+void DutyCycleSim::SetFrequency(units::hertz_t frequency) {
+  HALSIM_SetDutyCycleFrequency(m_index, frequency.value());
 }
 
 std::unique_ptr<CallbackStore> DutyCycleSim::RegisterOutputCallback(