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

pin_tinygo.go

@@ -0,0 +1,57 @@
+//go:build tinygo
+
+// Implementation of the Pin interface for tinygo (baremetal), depends on "machine" package.
+// SafePin, SafePinInput and SafePinOutput wrappers must be used in constructors of drivers.
+
+package drivers
+
+import (
+	"machine"
+)
+
+// MachinePin wraps machine.Pin to ensure correct pin mode is set when Get or Set methods are called.
+
+type MachinePin struct {
+	pin     machine.Pin
+	mode    machine.PinMode
+	modeSet bool
+}
+
+func (p *MachinePin) Get() bool {
+	if !p.modeSet || p.mode != machine.PinInput {
+		p.pin.Configure(machine.PinConfig{Mode: machine.PinInput})
+		p.mode = machine.PinInput
+	}
+	return p.pin.Get()
+}
+
+func (p *MachinePin) Set(high bool) {
+	if !p.modeSet || p.mode != machine.PinOutput {
+		p.pin.Configure(machine.PinConfig{Mode: machine.PinOutput})
+		p.mode = machine.PinOutput
+	}
+	p.pin.Set(high)
+}
+
+// Wrappers for Pin, PinInput and PinOutput interfaces that convert machine.Pin to safe MachinePin.
+
+func SafePinInput(pin PinInput) PinInput {
+	if p, ok := pin.(machine.Pin); ok {
+		return &MachinePin{pin: p}
+	}
+	return pin
+}
+
+func SafePinOutput(pin PinOutput) PinOutput {
+	if p, ok := pin.(machine.Pin); ok {
+		return &MachinePin{pin: p}
+	}
+	return pin
+}
+
+func SafePin(pin Pin) Pin {
+	if p, ok := pin.(machine.Pin); ok {
+		return &MachinePin{pin: p}
+	}
+	return pin
+}