artf4700: Added DigitalGlitchFilter

Initial Java support from Tyler Veness.
Final java support done by Jerry Morrison.

Change-Id: I1f85eb555f9ea4c0250c4c6729d7c51a76f5bef4

wpilibc/Athena/src/DigitalGlitchFilter.cpp

@@ -0,0 +1,198 @@
+/*----------------------------------------------------------------------------*/
+/* Copyright (c) FIRST 2015. 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 $(WIND_BASE)/WPILib.  */
+/*----------------------------------------------------------------------------*/
+
+#include <algorithm>
+#include <array>
+
+#include "DigitalGlitchFilter.h"
+#include "Resource.h"
+#include "WPIErrors.h"
+#include "Encoder.h"
+#include "Counter.h"
+#include "Utility.h"
+
+std::array<bool, 3> DigitalGlitchFilter::m_filterAllocated = {{false, false,
+                                                               false}};
+priority_mutex DigitalGlitchFilter::m_mutex;
+
+DigitalGlitchFilter::DigitalGlitchFilter() {
+  std::lock_guard<priority_mutex> sync(m_mutex);
+  auto index =
+      std::find(m_filterAllocated.begin(), m_filterAllocated.end(), false);
+  wpi_assert(index != m_filterAllocated.end());
+
+  m_channelIndex = std::distance(m_filterAllocated.begin(), index);
+  *index = true;
+}
+
+DigitalGlitchFilter::~DigitalGlitchFilter() {
+  if (m_channelIndex >= 0) {
+    std::lock_guard<priority_mutex> sync(m_mutex);
+    m_filterAllocated[m_channelIndex] = false;
+  }
+}
+
+/**
+ * Assigns the DigitalSource to this glitch filter.
+ *
+ * @param input The DigitalSource to add.
+ */
+void DigitalGlitchFilter::Add(DigitalSource *input) {
+  DoAdd(input, m_channelIndex + 1);
+}
+
+void DigitalGlitchFilter::DoAdd(DigitalSource *input, int requested_index) {
+  // Some sources from Counters and Encoders are null.  By pushing the check
+  // here, we catch the issue more generally.
+  if (input) {
+    int32_t status = 0;
+    setFilterSelect(m_digital_ports[input->GetChannelForRouting()],
+                    requested_index, &status);
+    wpi_setErrorWithContext(status, getHALErrorMessage(status));
+
+    // Validate that we set it correctly.
+    int actual_index = getFilterSelect(
+        m_digital_ports[input->GetChannelForRouting()], &status);
+    wpi_assertEqual(actual_index, requested_index);
+
+    HALReport(HALUsageReporting::kResourceType_DigitalInput,
+              input->GetChannelForRouting());
+  }
+}
+
+/**
+ * Assigns the Encoder to this glitch filter.
+ *
+ * @param input The Encoder to add.
+ */
+void DigitalGlitchFilter::Add(Encoder *input) {
+  Add(input->m_aSource.get());
+  if (StatusIsFatal()) {
+    return;
+  }
+  Add(input->m_bSource.get());
+}
+
+/**
+ * Assigns the Counter to this glitch filter.
+ *
+ * @param input The Counter to add.
+ */
+void DigitalGlitchFilter::Add(Counter *input) {
+  Add(input->m_upSource.get());
+  if (StatusIsFatal()) {
+    return;
+  }
+  Add(input->m_downSource.get());
+}
+
+/**
+ * Removes a digital input from this filter.
+ *
+ * Removes the DigitalSource from this glitch filter and re-assigns it to
+ * the default filter.
+ *
+ * @param input The DigitalSource to remove.
+ */
+void DigitalGlitchFilter::Remove(DigitalSource *input) {
+  DoAdd(input, 0);
+}
+
+/**
+ * Removes an encoder from this filter.
+ *
+ * Removes the Encoder from this glitch filter and re-assigns it to
+ * the default filter.
+ *
+ * @param input The Encoder to remove.
+ */
+void DigitalGlitchFilter::Remove(Encoder *input) {
+  Remove(input->m_aSource.get());
+  if (StatusIsFatal()) {
+    return;
+  }
+  Remove(input->m_bSource.get());
+}
+
+/**
+ * Removes a counter from this filter.
+ *
+ * Removes the Counter from this glitch filter and re-assigns it to
+ * the default filter.
+ *
+ * @param input The Counter to remove.
+ */
+void DigitalGlitchFilter::Remove(Counter *input) {
+  Remove(input->m_upSource.get());
+  if (StatusIsFatal()) {
+    return;
+  }
+  Remove(input->m_downSource.get());
+}
+
+/**
+ * Sets the number of cycles that the input must not change state for.
+ *
+ * @param fpga_cycles The number of FPGA cycles.
+ */
+void DigitalGlitchFilter::SetPeriodCycles(uint32_t fpga_cycles) {
+  int32_t status = 0;
+  setFilterPeriod(m_channelIndex, fpga_cycles, &status);
+  wpi_setErrorWithContext(status, getHALErrorMessage(status));
+
+  HALReport(HALUsageReporting::kResourceType_DigitalGlitchFilter,
+            m_channelIndex);
+}
+
+/**
+ * Sets the number of nanoseconds that the input must not change state for.
+ *
+ * @param nanoseconds The number of nanoseconds.
+ */
+void DigitalGlitchFilter::SetPeriodNanoSeconds(uint64_t nanoseconds) {
+  int32_t status = 0;
+  uint32_t fpga_cycles =
+      nanoseconds * kSystemClockTicksPerMicrosecond / 4 / 1000;
+  setFilterPeriod(m_channelIndex, fpga_cycles, &status);
+
+  wpi_setErrorWithContext(status, getHALErrorMessage(status));
+
+  HALReport(HALUsageReporting::kResourceType_DigitalGlitchFilter,
+            m_channelIndex);
+}
+
+/**
+ * Gets the number of cycles that the input must not change state for.
+ *
+ * @return The number of cycles.
+ */
+uint32_t DigitalGlitchFilter::GetPeriodCycles() {
+  int32_t status = 0;
+  uint32_t fpga_cycles = getFilterPeriod(m_channelIndex, &status);
+
+  wpi_setErrorWithContext(status, getHALErrorMessage(status));
+
+  HALReport(HALUsageReporting::kResourceType_DigitalGlitchFilter,
+            m_channelIndex);
+  return fpga_cycles;
+}
+
+/**
+ * Gets the number of nanoseconds that the input must not change state for.
+ *
+ * @return The number of nanoseconds.
+ */
+uint64_t DigitalGlitchFilter::GetPeriodNanoSeconds() {
+  int32_t status = 0;
+  uint32_t fpga_cycles = getFilterPeriod(m_channelIndex, &status);
+
+  wpi_setErrorWithContext(status, getHALErrorMessage(status));
+
+  HALReport(HALUsageReporting::kResourceType_DigitalGlitchFilter,
+            m_channelIndex);
+  return static_cast<uint64_t>(fpga_cycles) * 1000L /
+         static_cast<uint64_t>(kSystemClockTicksPerMicrosecond / 4);
+}