Properly set the Chip ID (#2431)

* Properly get the Chip ID

* These tests would block forever in an error case

* Disposing the controller would always dispose the driver

... thus this would never run successfully in case of a retry

* Fix a markdown warning

Author: pgrawehr

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

@@ -320,18 +320,10 @@ void Callback(object sender, PinValueChangedEventArgs e)
     [Fact]
     public void AddCallbackRemoveAllCallbackTest()
     {
-        using GpioDriver testDriver = GetTestDriver();
-        // Skipping the test for now when using the SysFsDriver or the RaspberryPi3Driver given that this test is flaky for those drivers.
-        // Issue tracking this problem is https://github.com/dotnet/iot/issues/629
-        if (testDriver is SysFsDriver || testDriver is RaspberryPi3Driver)
-        {
-            return;
-        }
-
         RetryHelper.Execute(() =>
         {
             int risingEventOccurredCount = 0, fallingEventOccurredCount = 0;
-            using (GpioController controller = new GpioController(testDriver))
+            using (GpioController controller = new GpioController(GetTestDriver()))
             {
                 controller.OpenPin(InputPin, PinMode.Input);
                 controller.OpenPin(OutputPin, PinMode.Output);
@@ -454,6 +446,7 @@ public void WaitForEventRisingEdgeTest()
         using (GpioController controller = new GpioController(GetTestDriver()))
         {
             CancellationTokenSource tokenSource = new CancellationTokenSource();
+            tokenSource.CancelAfter(TimeSpan.FromSeconds(20));
             controller.OpenPin(InputPin, PinMode.Input);
             controller.OpenPin(OutputPin, PinMode.Output);
             controller.Write(OutputPin, PinValue.Low);
@@ -479,6 +472,7 @@ public void WaitForEventFallingEdgeTest()
             using (GpioController controller = new GpioController(GetTestDriver()))
             {
                 CancellationTokenSource tokenSource = new CancellationTokenSource();
+                tokenSource.CancelAfter(TimeSpan.FromSeconds(30));
                 controller.OpenPin(InputPin, PinMode.Input);
                 controller.OpenPin(OutputPin, PinMode.Output);
                 controller.Write(OutputPin, PinValue.Low);

src/System.Device.Gpio/System/Device/Gpio/Drivers/LibGpiodDriver.cs

@@ -9,7 +9,7 @@
 using System.Diagnostics;
 using System.Linq;
 using System.Diagnostics.CodeAnalysis;
-
+using System.Globalization;
 using LibgpiodV1 = Interop.LibgpiodV1;
 
 namespace System.Device.Gpio.Drivers;
@@ -114,7 +114,6 @@ public static IList<GpioChipInfo> GetAvailableChips()
     {
         List<GpioChipInfo> result = new List<GpioChipInfo>();
         var iterator = new SafeChipIteratorHandle(LibgpiodV1.gpiod_chip_iter_new());
-        int index = 0;
         while (true)
         {
             SafeChipHandle chip = new SafeChipHandle(LibgpiodV1.gpiod_chip_iter_next_noclose(iterator));
@@ -129,8 +128,26 @@ public static IList<GpioChipInfo> GetAvailableChips()
             if (!result.Any(x => x.Label == label && x.NumLines == numLines))
             {
                 // The iterator may find duplicates, but we skip them here
-                result.Add(new GpioChipInfo(index, name, label, numLines));
-                index++;
+                // Need to find the number at the end of the name (e.g. 15 in gpiochip15)
+                int id = 0;
+                int numberOfDigitsAtEnd = 0;
+                for (var i = name.Length - 1; i >= 0; i--)
+                {
+                    if (!char.IsDigit(name[i]))
+                    {
+                        break;
+                    }
+
+                    numberOfDigitsAtEnd++;
+                }
+
+                string theNumber = name[^numberOfDigitsAtEnd..];
+                if (!Int32.TryParse(theNumber, CultureInfo.InvariantCulture, out id))
+                {
+                    id = 0;
+                }
+
+                result.Add(new GpioChipInfo(id, name, label, numLines));
             }
 
             chip.Dispose();