Pin HAL to break dependency of drivers from TinyGo's machine package

pin.go

@@ -0,0 +1,37 @@
+package drivers
+
+// Pin types abstract the underlying implementation of a pin,
+// allowing the use of different hardware or libraries without changing driver code.
+//
+// Note, pin mode functionality is not part of the Pin interface.
+// Implementations must ensure correct pin mode is set when Get or Set methods are called.
+//
+// Drivers must use SafePin(), SafePinInput() and SafePinOutput() wrappers in constructors.
+// The client code can pass either machine.Pin or a custom implementation of the Pin interface.
+// Wrappers for TinyGo's machine.Pin are provided in pin_tinygo.go.
+// It's custom implementation's responsibility to configure the pin modes correctly as
+// Wrappers in pin_generic.go are no-ops.
+
+// PinInput is an interface for reading the state of a pin.
+type PinInput interface {
+	Get() bool
+}
+
+// PinOutput is an interface for setting the state of a pin.
+type PinOutput interface {
+	Set(bool)
+}
+
+// Pin is an interface for a pin that can be both input and output.
+type Pin interface {
+	PinInput
+	PinOutput
+}
+
+// PinGet is a function type for getting the state of a pin
+// Shall be used in high-performance drivers to avoid interface call overhead.
+type PinGet func() bool
+
+// PinSet is a function type for setting the state of a pin.
+// Shall be used in high-performance drivers to avoid interface call overhead.
+type PinSet func(bool)