Make LibGpiodDriver V2 driver public

src/System.Device.Gpio.Tests/GpioControllerTestBase.cs

@@ -3,6 +3,7 @@
 
 using System.Device.Gpio.Drivers;
 using System.Diagnostics;
+using System.IO;
 using System.Threading;
 using System.Threading.Tasks;
 using Xunit;
@@ -23,6 +24,8 @@ protected GpioControllerTestBase(ITestOutputHelper testOutputHelper)
         _testOutputHelper = testOutputHelper;
     }
 
+    protected ITestOutputHelper Logger => _testOutputHelper;
+
     [Theory]
     [InlineData(true)]
     [InlineData(false)]
@@ -624,4 +627,18 @@ public void UsingControllerAfterDisposeCausesException()
     }
 
     protected abstract GpioDriver GetTestDriver();
+
+    protected bool IsRaspi4()
+    {
+        if (File.Exists("/proc/device-tree/model"))
+        {
+            string model = File.ReadAllText("/proc/device-tree/model", Text.Encoding.ASCII);
+            if (model.Contains("Raspberry Pi 4") || model.Contains("Raspberry Pi Compute Module 4"))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
 }

src/System.Device.Gpio.Tests/LibGpiodV1DriverTests.cs

@@ -2,7 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Device.Gpio.Drivers;
-using System.Device.Gpio.Drivers.Libgpiod.V1;
+using System.Diagnostics;
 using System.Threading;
 using Xunit;
 using Xunit.Abstractions;
@@ -21,9 +21,7 @@ public LibGpiodV1DriverTests(ITestOutputHelper testOutputHelper)
     {
     }
 
-#pragma warning disable SDGPIO0001
-    protected override GpioDriver GetTestDriver() => new LibGpiodDriver(0, LibGpiodDriverVersion.V1);
-#pragma warning restore SDGPIO0001
+    protected override GpioDriver GetTestDriver() => new LibGpiodDriver(0);
 
     [Fact]
     public void SetPinModeSetsDefaultValue()
@@ -106,4 +104,32 @@ public void LeakingDriverDoesNotCrash()
 
         GC.WaitForPendingFinalizers();
     }
+
+    [Fact]
+    public void CheckAllChipsCanBeConstructed()
+    {
+        var chips = LibGpiodDriver.GetAvailableChips();
+        foreach (var c in chips)
+        {
+            Logger.WriteLine(c.ToString());
+        }
+
+        Assert.NotEmpty(chips);
+        if (IsRaspi4())
+        {
+            // 2 entries. Here they're always named 0 and 1
+            Assert.Equal(2, chips.Count);
+        }
+
+        foreach (var chip in chips)
+        {
+            var driver = new LibGpiodDriver(chip.Id);
+            var ctrl = new GpioController(driver);
+            Assert.NotNull(ctrl);
+            var driverInfo = driver.GetChipInfo();
+            Assert.NotNull(driverInfo);
+            Assert.Equal(chip, driverInfo);
+            ctrl.Dispose();
+        }
+    }
 }

src/System.Device.Gpio.Tests/LibGpiodV2DriverTests.cs

@@ -2,8 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Device.Gpio.Drivers;
-using System.Diagnostics;
-using System.Threading.Tasks;
 using Xunit;
 using Xunit.Abstractions;
 
@@ -22,6 +20,34 @@ public LibGpiodV2DriverTests(ITestOutputHelper testOutputHelper)
     {
     }
 
+    [Fact]
+    public void CheckAllChipsCanBeConstructed()
+    {
+        var chips = LibGpiodV2Driver.GetAvailableChips();
+        foreach (var c in chips)
+        {
+            Logger.WriteLine(c.ToString());
+        }
+
+        Assert.NotEmpty(chips);
+        if (IsRaspi4())
+        {
+            // 3 real ones and the default 0 entry
+            Assert.Equal(3, chips.Count);
+        }
+
+        foreach (var chip in chips)
+        {
+            var driver = new LibGpiodV2Driver(chip.Id);
+            var ctrl = new GpioController(driver);
+            Assert.NotNull(ctrl);
+            var driverInfo = driver.GetChipInfo();
+            Assert.NotNull(driverInfo);
+            Assert.Equal(chip, driverInfo);
+            ctrl.Dispose();
+        }
+    }
+
 #pragma warning disable SDGPIO0001
-    protected override GpioDriver GetTestDriver() => new LibGpiodDriver(ChipNumber, LibGpiodDriverVersion.V2);
+    protected override GpioDriver GetTestDriver() => new LibGpiodV2Driver(ChipNumber);
 }

src/System.Device.Gpio.Tests/RaspberryPiDriverTests.cs

@@ -25,20 +25,6 @@ public RaspberryPiDriverTests(ITestOutputHelper testOutputHelper)
 
     protected override GpioDriver GetTestDriver() => new RaspberryPi3Driver();
 
-    private bool IsRaspi4()
-    {
-        if (File.Exists("/proc/device-tree/model"))
-        {
-            string model = File.ReadAllText("/proc/device-tree/model", Text.Encoding.ASCII);
-            if (model.Contains("Raspberry Pi 4") || model.Contains("Raspberry Pi Compute Module 4"))
-            {
-                return true;
-            }
-        }
-
-        return false;
-    }
-
     /// <summary>
     /// Tests for setting the pull up/pull down resistors on the Raspberry Pi (supported on Pi3 and Pi4, but with different techniques)
     /// </summary>

src/System.Device.Gpio.Tests/SysFsDriverTests.cs

@@ -2,9 +2,11 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Device.Gpio.Drivers;
+using System.IO;
 using Xunit;
 using Xunit.Abstractions;
 
+#pragma warning disable SDGPIO0001
 namespace System.Device.Gpio.Tests;
 
 [Trait("requirement", "root")]
@@ -19,4 +21,40 @@ public SysFsDriverTests(ITestOutputHelper testOutputHelper)
     }
 
     protected override GpioDriver GetTestDriver() => new SysFsDriver();
+
+    [Fact]
+    public void CheckAllChipsCanBeConstructed()
+    {
+        string[] fileNames = Directory.GetFileSystemEntries("/sys/class/gpio", $"*", SearchOption.TopDirectoryOnly);
+        Logger.WriteLine("Content of /sys/class/gpio:");
+        foreach (var f in fileNames)
+        {
+            Logger.WriteLine(f);
+        }
+
+        var chips = SysFsDriver.GetAvailableChips();
+        Logger.WriteLine("Available chips:");
+        foreach (var c in chips)
+        {
+            Logger.WriteLine(c.ToString());
+        }
+
+        Assert.NotEmpty(chips);
+        if (IsRaspi4())
+        {
+            // 2 real ones and the default 0 entry
+            Assert.Equal(3, chips.Count);
+        }
+
+        foreach (var chip in chips)
+        {
+            var driver = new SysFsDriver(chip);
+            var ctrl = new GpioController(driver);
+            Assert.NotNull(ctrl);
+            var driverInfo = driver.GetChipInfo();
+            Assert.NotNull(driverInfo);
+            Assert.Equal(chip, driverInfo);
+            ctrl.Dispose();
+        }
+    }
 }

src/System.Device.Gpio/Interop/Unix/libgpiod/V1/Interop.libgpiod.cs

@@ -53,11 +53,25 @@ static LibgpiodV1()
         }
 
         /// <summary>
-        /// Release all resources allocated for the gpiochip iterator and close the most recently opened gpiochip(if any).
+        /// Release all resources allocated for the gpiochip iterator but does not close the most recently opened gpiochip
         /// </summary>
         /// <param name="iter">The gpiochip iterator object</param>
         [DllImport(LibgpiodLibrary)]
-        internal static extern void gpiod_chip_iter_free(IntPtr iter);
+        internal static extern void gpiod_chip_iter_free_noclose(IntPtr iter);
+
+        /// <summary>
+        /// Start an iteration over the list of gpio chips.
+        /// </summary>
+        [DllImport(LibgpiodLibrary)]
+        internal static extern IntPtr gpiod_chip_iter_new();
+
+        /// <summary>
+        /// Iterate over a chip iterator. Does not close any previously opened chips.
+        /// </summary>
+        /// <param name="handle">Handle of a chip iterator</param>
+        /// <returns>The next chip handle or null if at the end of the iteration</returns>
+        [DllImport(LibgpiodLibrary)]
+        internal static extern IntPtr gpiod_chip_iter_next_noclose(SafeChipIteratorHandle handle);
 
         /// <summary>
         /// Close a GPIO chip handle and release all allocated resources.
@@ -195,14 +209,20 @@ static LibgpiodV1()
         /// </summary>
         /// <returns>GPIO chip pointer handle or NULL if an error occurred.</returns>
         [DllImport(LibgpiodLibrary, SetLastError = true)]
-        internal static extern SafeChipHandle gpiod_chip_open_by_number(int number);
+        internal static extern IntPtr gpiod_chip_open_by_number(int number);
 
         /// <summary>
         /// Get the API version of the library as a human-readable string.
         /// </summary>
         /// <returns>Human-readable string containing the library version.</returns>
         [DllImport(LibgpiodLibrary, SetLastError = true)]
         internal static extern IntPtr gpiod_version_string();
+
+        [DllImport(LibgpiodLibrary)]
+        internal static extern IntPtr gpiod_chip_name(SafeChipHandle chip);
+
+        [DllImport(LibgpiodLibrary)]
+        internal static extern IntPtr gpiod_chip_label(SafeChipHandle chip);
     }
 }
 

src/System.Device.Gpio/Interop/Unix/libgpiod/V1/SafeChipHandle.cs

@@ -11,14 +11,15 @@ namespace System.Device.Gpio.Libgpiod.V1;
 /// </summary>
 internal class SafeChipHandle : SafeHandle
 {
-    public SafeChipHandle()
-        : base(IntPtr.Zero, true)
+    public SafeChipHandle(IntPtr h)
+        : base(h, true)
     {
     }
 
     protected override bool ReleaseHandle()
     {
         LibgpiodV1.gpiod_chip_close(handle);
+        SetHandle(IntPtr.Zero);
         return true;
     }
 

src/System.Device.Gpio/Interop/Unix/libgpiod/V1/SafeChipIteratorHandle.cs

@@ -11,14 +11,16 @@ namespace System.Device.Gpio.Libgpiod.V1;
 /// </summary>
 internal class SafeChipIteratorHandle : SafeHandle
 {
-    public SafeChipIteratorHandle()
-        : base(IntPtr.Zero, true)
+    public SafeChipIteratorHandle(IntPtr handle)
+        : base(handle, true)
     {
     }
 
     protected override bool ReleaseHandle()
     {
-        LibgpiodV1.gpiod_chip_iter_free(handle);
+        // We can't close the chip here, as this would possibly result in it being freed twice, which causes a crash
+        LibgpiodV1.gpiod_chip_iter_free_noclose(handle);
+        handle = IntPtr.Zero;
         return true;
     }
 

src/System.Device.Gpio/Interop/Unix/libgpiod/V2/Proxies/Chip.cs

@@ -17,16 +17,19 @@ namespace System.Device.Gpio.Libgpiod.V2;
 [Experimental(DiagnosticIds.SDGPIO0001, UrlFormat = DiagnosticIds.UrlFormat)]
 internal class Chip : LibGpiodProxyBase
 {
+    private readonly int _chipNumber;
     private readonly ChipSafeHandle _handle;
 
     /// <summary>
     /// Constructor for a chip-proxy object. This call will try to open the chip.
     /// </summary>
+    /// <param name="chipNumber">The chip number</param>
     /// <param name="handle">Safe handle to the libgpiod object.</param>
     /// <seealso href="https://libgpiod.readthedocs.io/en/latest/group__chips.html#ga25097f48949d0ac81e9ab341193da1a4"/>
-    public Chip(ChipSafeHandle handle)
+    public Chip(int chipNumber, ChipSafeHandle handle)
         : base(handle)
     {
+        _chipNumber = chipNumber;
         _handle = handle;
     }
 
@@ -46,7 +49,7 @@ public string GetPath()
     /// </summary>
     /// <seealso href="https://libgpiod.readthedocs.io/en/latest/group__chips.html#gad65098ba48da0f22d1b0be149b4cf578"/>
     /// <exception cref="GpiodException">Unexpected error invoking native function</exception>
-    public ChipInfo GetInfo()
+    public LibGpiodChipInfo GetInfo()
     {
         return CallLibgpiod(() =>
         {
@@ -57,7 +60,7 @@ public ChipInfo GetInfo()
                 throw new GpiodException($"Could not get chip info: {LastErr.GetMsg()}");
             }
 
-            return new ChipInfo(chipInfoHandle);
+            return new LibGpiodChipInfo(_chipNumber, chipInfoHandle);
         });
     }
 
@@ -207,39 +210,4 @@ public LineRequest RequestLines(RequestConfig requestConfig, LineConfig lineConf
             return new LineRequest(lineRequestHandle);
         });
     }
-
-    /// <summary>
-    /// Helper function for capturing information and creating an immutable snapshot instance.
-    /// </summary>
-    /// <exception cref="GpiodException">Unexpected error when invoking native function</exception>
-    public Snapshot MakeSnapshot()
-    {
-        using var chipInfo = GetInfo();
-        var chipInfoSnapshot = chipInfo.MakeSnapshot();
-        int numLines = chipInfoSnapshot.NumLines;
-        List<LineInfo.Snapshot> lineInfos = new();
-        for (uint offset = 0; offset < numLines; offset++)
-        {
-            using var lineInfo = GetLineInfo(offset);
-            var lineInfoSnapshot = lineInfo.MakeSnapshot();
-            lineInfos.Add(lineInfoSnapshot);
-        }
-
-        return new Snapshot(chipInfoSnapshot, GetPath(), GetFileDescriptor(), lineInfos);
-    }
-
-    /// <summary>
-    /// Contains all readable information that was recorded at one and the same time
-    /// </summary>
-    public sealed record Snapshot(ChipInfo.Snapshot ChipInfo, string Path, int FileDescriptor, IEnumerable<LineInfo.Snapshot> LineInfos)
-    {
-        /// <summary>
-        /// Converts the whole snapshot to string
-        /// </summary>
-        public override string ToString()
-        {
-            return
-                $"{nameof(ChipInfo)}: {ChipInfo}, {nameof(Path)}: {Path}, {nameof(FileDescriptor)}: {FileDescriptor}, {nameof(LineInfos)}: {string.Join("\n", LineInfos)}";
-        }
-    }
 }