Add DMA support to HAL and WPILibC (#2080)

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

@@ -201,6 +201,14 @@ double HAL_GetAnalogVoltage(HAL_AnalogInputHandle analogPortHandle,
   return voltage;
 }
 
+double HAL_GetAnalogValueToVolts(HAL_AnalogInputHandle analogPortHandle,
+                                 int32_t rawValue, int32_t* status) {
+  int32_t LSBWeight = HAL_GetAnalogLSBWeight(analogPortHandle, status);
+  int32_t offset = HAL_GetAnalogOffset(analogPortHandle, status);
+  double voltage = LSBWeight * 1.0e-9 * rawValue - offset * 1.0e-9;
+  return voltage;
+}
+
 double HAL_GetAnalogAverageVoltage(HAL_AnalogInputHandle analogPortHandle,
                                    int32_t* status) {
   int32_t value = HAL_GetAnalogAverageValue(analogPortHandle, status);

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

@@ -238,6 +238,19 @@ void InitializeEncoder() {
 }  // namespace init
 }  // namespace hal
 
+namespace hal {
+bool GetEncoderBaseHandle(HAL_EncoderHandle handle,
+                          HAL_FPGAEncoderHandle* fpgaHandle,
+                          HAL_CounterHandle* counterHandle) {
+  auto encoder = encoderHandles->Get(handle);
+  if (!handle) return false;
+
+  *fpgaHandle = encoder->m_encoder;
+  *counterHandle = encoder->m_counter;
+  return true;
+}
+}  // namespace hal
+
 extern "C" {
 HAL_EncoderHandle HAL_InitializeEncoder(
     HAL_Handle digitalSourceHandleA, HAL_AnalogTriggerType analogTriggerTypeA,

hal/src/main/native/athena/EncoderInternal.h

@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2016-2018 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2016-2019 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -13,8 +13,16 @@
 
 namespace hal {
 
+bool GetEncoderBaseHandle(HAL_EncoderHandle handle,
+                          HAL_FPGAEncoderHandle* fpgaEncoderHandle,
+                          HAL_CounterHandle* counterHandle);
+
 class Encoder {
  public:
+  friend bool GetEncoderBaseHandle(HAL_EncoderHandle handle,
+                                   HAL_FPGAEncoderHandle* fpgaEncoderHandle,
+                                   HAL_CounterHandle* counterHandle);
+
   Encoder(HAL_Handle digitalSourceHandleA,
           HAL_AnalogTriggerType analogTriggerTypeA,
           HAL_Handle digitalSourceHandleB,

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

@@ -56,6 +56,7 @@ void InitializeHAL() {
   InitializeCounter();
   InitializeDigitalInternal();
   InitializeDIO();
+  InitializeDMA();
   InitializeDutyCycle();
   InitializeEncoder();
   InitializeFPGAEncoder();
@@ -256,6 +257,28 @@ uint64_t HAL_GetFPGATime(int32_t* status) {
   return (upper2 << 32) + lower;
 }
 
+uint64_t HAL_ExpandFPGATime(uint32_t unexpanded_lower, int32_t* status) {
+  // Capture the current FPGA time.  This will give us the upper half of the
+  // clock.
+  uint64_t fpga_time = HAL_GetFPGATime(status);
+  if (*status != 0) return 0;
+
+  // Now, we need to detect the case where the lower bits rolled over after we
+  // sampled.  In that case, the upper bits will be 1 bigger than they should
+  // be.
+
+  // Break it into lower and upper portions.
+  uint32_t lower = fpga_time & 0xffffffffull;
+  uint64_t upper = (fpga_time >> 32) & 0xffffffff;
+
+  // The time was sampled *before* the current time, so roll it back.
+  if (lower < unexpanded_lower) {
+    --upper;
+  }
+
+  return (upper << 32) + static_cast<uint64_t>(unexpanded_lower);
+}
+
 HAL_Bool HAL_GetFPGAButton(int32_t* status) {
   if (!global) {
     *status = NiFpga_Status_ResourceNotInitialized;

hal/src/main/native/athena/HALInitializer.h

@@ -32,6 +32,7 @@ extern void InitializeConstants();
 extern void InitializeCounter();
 extern void InitializeDigitalInternal();
 extern void InitializeDIO();
+extern void InitializeDMA();
 extern void InitializeDutyCycle();
 extern void InitializeEncoder();
 extern void InitializeFPGAEncoder();