finish rewrites!

internal/legacy/pinhal.go

@@ -63,6 +63,13 @@ func ConfigurePinInputPullup(pi PinInput) {
 	configurePinInputPullup(pi)
 }
 
+// PinIsNoPin returns true if the argument is a machine.Pin type and is the machine.NoPin predeclared type.
+//
+// Deprecated: Drivers do not require pin knowledge from now on.
+func PinIsNoPin(pin any) bool {
+	return pinIsNoPin(pin)
+}
+
 var (
 	ErrConfigBeforeInstantiated = errors.New("device must be instantiated with New before calling Configure method")
 )

internal/legacy/pinhal_baremetal.go

@@ -20,6 +20,11 @@ func configurePinInputPullup(p PinInput) {
 	configurePin(p, machine.PinInputPullup)
 }
 
+func pinIsNoPin(a any) bool {
+	p, ok := a.(machine.Pin)
+	return ok && p == machine.NoPin
+}
+
 func configurePin(p any, mode machine.PinMode) {
 	machinePin, ok := p.(machine.Pin)
 	if ok {

internal/legacy/pinhal_os.go

@@ -6,3 +6,4 @@ func configurePinOut(p PinOutput)          {}
 func configurePinInput(p PinInput)         {}
 func configurePinInputPulldown(p PinInput) {}
 func configurePinInputPullup(p PinInput)   {}
+func pinIsNoPin(a any) bool                { return false }