Merge pull request #12 from mk868/drive-mode

Drive mode improvements + Javadoc

jgpio-it/src/test/java/eu/softpol/lib/jgpioit/LineSessionBiasChangeIT.java

@@ -21,7 +21,7 @@ class LineSessionBiasChangeIT {
 
   @ParameterizedTest
   @FieldSource("PINS")
-  void read_value_should_read_actual_bias_value_on_hanging_line(TestPin inputWithBiasPin) {
+  void should_read_value_matching_bias_on_hanging_line(TestPin inputWithBiasPin) {
     var jgpio = Jgpio.getInstance();
     try (var inputChip1 = jgpio.openChipByName(inputWithBiasPin.chipName());
         var biasInputLine = inputChip1.getLine(inputWithBiasPin.lineOffset())
@@ -38,9 +38,37 @@ void read_value_should_read_actual_bias_value_on_hanging_line(TestPin inputWithB
     }
   }
 
+  @ParameterizedTest
+  @FieldSource("PINS")
+  void should_read_true_for_pull_up_bias_on_hanging_line(TestPin inputWithBiasPin) {
+    var jgpio = Jgpio.getInstance();
+    try (var inputChip1 = jgpio.openChipByName(inputWithBiasPin.chipName());
+        var biasInputLine = inputChip1.getLine(inputWithBiasPin.lineOffset())
+            .openAsInput(Bias.PULL_UP);
+    ) {
+      assertThat(biasInputLine.read())
+          .as("Input line level")
+          .isTrue();
+    }
+  }
+
+  @ParameterizedTest
+  @FieldSource("PINS")
+  void should_read_false_for_pull_down_bias_on_hanging_line(TestPin inputWithBiasPin) {
+    var jgpio = Jgpio.getInstance();
+    try (var inputChip1 = jgpio.openChipByName(inputWithBiasPin.chipName());
+        var biasInputLine = inputChip1.getLine(inputWithBiasPin.lineOffset())
+            .openAsInput(Bias.PULL_DOWN);
+    ) {
+      assertThat(biasInputLine.read())
+          .as("Input line level")
+          .isFalse();
+    }
+  }
+
   @ParameterizedTest
   @FieldSource("COUPLED_LINES")
-  void high_impedance_line_should_detect_bias_change_on_coupled_line(TwoPins coupledLines) {
+  void should_read_value_matching_bias_on_coupled_line(TwoPins coupledLines) {
     var inputWithBiasPin = coupledLines.pin1();
     var inputNoBiasPin = coupledLines.pin2();
 
@@ -62,4 +90,44 @@ void high_impedance_line_should_detect_bias_change_on_coupled_line(TwoPins coupl
           .isFalse();
     }
   }
+
+  @ParameterizedTest
+  @FieldSource("COUPLED_LINES")
+  void should_read_true_for_pull_up_bias_on_coupled_line(TwoPins coupledLines) {
+    var inputWithBiasPin = coupledLines.pin1();
+    var inputNoBiasPin = coupledLines.pin2();
+
+    var jgpio = Jgpio.getInstance();
+    try (var inputChip1 = jgpio.openChipByName(inputWithBiasPin.chipName());
+        var _ = inputChip1.getLine(inputWithBiasPin.lineOffset())
+            .openAsInput(Bias.PULL_UP);
+        var inputChip2 = jgpio.openChipByName(inputNoBiasPin.chipName());
+        var highImpedanceLine = inputChip2.getLine(inputNoBiasPin.lineOffset())
+            .openAsInput(Bias.HIGH_IMPEDANCE);
+    ) {
+      assertThat(highImpedanceLine.read())
+          .as("Input line level")
+          .isTrue();
+    }
+  }
+
+  @ParameterizedTest
+  @FieldSource("COUPLED_LINES")
+  void should_read_true_for_pull_down_bias_on_coupled_line(TwoPins coupledLines) {
+    var inputWithBiasPin = coupledLines.pin1();
+    var inputNoBiasPin = coupledLines.pin2();
+
+    var jgpio = Jgpio.getInstance();
+    try (var inputChip1 = jgpio.openChipByName(inputWithBiasPin.chipName());
+        var _ = inputChip1.getLine(inputWithBiasPin.lineOffset())
+            .openAsInput(Bias.PULL_DOWN);
+        var inputChip2 = jgpio.openChipByName(inputNoBiasPin.chipName());
+        var highImpedanceLine = inputChip2.getLine(inputNoBiasPin.lineOffset())
+            .openAsInput(Bias.HIGH_IMPEDANCE);
+    ) {
+      assertThat(highImpedanceLine.read())
+          .as("Input line level")
+          .isFalse();
+    }
+  }
 }

jgpio-it/src/test/java/eu/softpol/lib/jgpioit/LineSessionWriteDriveIT.java

@@ -40,7 +40,7 @@ private static Stream<Arguments> args() {
         of(OPEN_DRAIN, Bias.HIGH_IMPEDANCE, false, false),
         //of(OPEN_DRAIN, Bias.HIGH_IMPEDANCE, true, undefined),
         of(OPEN_DRAIN, Bias.PULL_UP, false, false),
-        of(OPEN_DRAIN, Bias.PULL_UP, true, true),//???
+        of(OPEN_DRAIN, Bias.PULL_UP, true, true),
         of(OPEN_DRAIN, Bias.PULL_DOWN, false, false),
         of(OPEN_DRAIN, Bias.PULL_DOWN, true, false),
         // OPEN_DRAIN_PULL_UP
@@ -55,7 +55,7 @@ private static Stream<Arguments> args() {
         of(OPEN_SOURCE, Bias.HIGH_IMPEDANCE, true, true),
         of(OPEN_SOURCE, Bias.PULL_UP, false, true),
         of(OPEN_SOURCE, Bias.PULL_UP, true, true),
-        of(OPEN_SOURCE, Bias.PULL_DOWN, false, false),//???
+        of(OPEN_SOURCE, Bias.PULL_DOWN, false, false),
         of(OPEN_SOURCE, Bias.PULL_DOWN, true, true),
         // OPEN_SOURCE_PULL_DOWN
         of(OPEN_SOURCE_PULL_DOWN, Bias.HIGH_IMPEDANCE, false, false),

jgpio/src/main/java/eu/softpol/lib/jgpio/DriveMode.java

@@ -15,10 +15,24 @@
  */
 package eu.softpol.lib.jgpio;
 
+/// Enum representing the drive modes for a GPIO line.
+///
+/// The DriveMode defines the configuration of the GPIO line's output driver.
 public enum DriveMode {
+  /// Drive mode where the GPIO line is actively driven to both high and low states.
   PUSH_PULL,
+  /// Drive mode where the GPIO line is set to open-drain. In this mode, the GPIO can either drive
+  /// the line low or leave it floating.
   OPEN_DRAIN,
+  /// Drive mode where the GPIO line is set to open-drain with an internal pull-up resistor. In this
+  /// mode, the GPIO can drive the line low, or use the pull-up resistor to bring the line to a high
+  /// state.
   OPEN_DRAIN_PULL_UP,
+  /// Drive mode where the GPIO line is set to open-source. In this mode, the GPIO can either drive
+  /// the line high or leave it floating.
   OPEN_SOURCE,
+  /// Drive mode where the GPIO line is set to open-source with an internal pull-down resistor. In
+  /// this mode, the GPIO can drive the line high, or use the pull-down resistor to bring the line
+  /// to a low state.
   OPEN_SOURCE_PULL_DOWN;
 }

jgpio/src/main/java/eu/softpol/lib/jgpio/Line.java

@@ -64,6 +64,10 @@ public interface Line {
   /// @return the session for the output line, which must be closed after use
   LineOutputSession openAsOutput();
 
+  /// Opens the GPIO line as an output with the specified drive mode.
+  ///
+  /// @param driveMode the drive mode to be set for the GPIO line
+  /// @return the session for the output line, which must be closed after use
   LineOutputSession openAsOutput(DriveMode driveMode);
 
 }

jgpio/src/main/java/eu/softpol/lib/jgpio/LineOutputSession.java

@@ -23,6 +23,9 @@
 /// The methods of this interface should not be called after [Chip#close()].
 public interface LineOutputSession extends Closeable {
 
+  /// Sets the drive mode for the output line.
+  ///
+  /// @param driveMode the drive mode to be set for the GPIO line
   void setDriveMode(DriveMode driveMode);
 
   /// Writes the new value of the output line.

jgpio/src/main/java/eu/softpol/lib/jgpio/internal/gpiod/GpiodLineOutputSession.java

@@ -15,9 +15,9 @@
  */
 package eu.softpol.lib.jgpio.internal.gpiod;
 
+import eu.softpol.lib.jgpio.DriveMode;
 import eu.softpol.lib.jgpio.JgpioException;
 import eu.softpol.lib.jgpio.LineOutputSession;
-import eu.softpol.lib.jgpio.DriveMode;
 import eu.softpol.lib.jgpio.internal.ffm.libgpiod.gpiod_h;
 import java.lang.System.Logger;
 import java.lang.System.Logger.Level;
@@ -75,11 +75,13 @@ public void write(boolean value) {
 
   private int toFlags(DriveMode driveMode) {
     return switch (driveMode) {
-      case PUSH_PULL -> 0;
-      case OPEN_DRAIN -> gpiod_h.GPIOD_LINE_REQUEST_FLAG_OPEN_DRAIN();
+      case PUSH_PULL -> gpiod_h.GPIOD_LINE_REQUEST_FLAG_BIAS_DISABLE();
+      case OPEN_DRAIN -> gpiod_h.GPIOD_LINE_REQUEST_FLAG_OPEN_DRAIN()
+          + gpiod_h.GPIOD_LINE_REQUEST_FLAG_BIAS_DISABLE();
       case OPEN_DRAIN_PULL_UP -> gpiod_h.GPIOD_LINE_REQUEST_FLAG_OPEN_DRAIN()
           + gpiod_h.GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP();
-      case OPEN_SOURCE -> gpiod_h.GPIOD_LINE_REQUEST_FLAG_OPEN_SOURCE();
+      case OPEN_SOURCE -> gpiod_h.GPIOD_LINE_REQUEST_FLAG_OPEN_SOURCE()
+          + gpiod_h.GPIOD_LINE_REQUEST_FLAG_BIAS_DISABLE();
       case OPEN_SOURCE_PULL_DOWN -> gpiod_h.GPIOD_LINE_REQUEST_FLAG_OPEN_SOURCE()
           + gpiod_h.GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_DOWN();
     };