GPIO: add read/write type (#25875)

plugin/gpio_linux.go

@@ -17,13 +17,15 @@ func init() {
 
 type gpio struct {
 	mu  sync.Mutex
+	typ GpioType
 	pin rpio.Pin
 }
 
 // NewGpioPluginFromConfig creates a GPIO provider
 func NewGpioPluginFromConfig(ctx context.Context, other map[string]any) (Plugin, error) {
 	var cc struct {
-		Pin int
+		Type GpioType
+		Pin  int
 	}
 
 	if err := util.DecodeOther(other, &cc); err != nil {
@@ -31,6 +33,7 @@ func NewGpioPluginFromConfig(ctx context.Context, other map[string]any) (Plugin,
 	}
 
 	p := &gpio{
+		typ: cc.Type,
 		pin: rpio.Pin(cc.Pin),
 	}
 
@@ -40,7 +43,14 @@ func NewGpioPluginFromConfig(ctx context.Context, other map[string]any) (Plugin,
 	}
 	defer rpio.Close()
 
-	p.pin.Input()
+	switch cc.Type {
+	case GpioTypeRead:
+		p.pin.Input()
+	case GpioTypeWrite:
+		p.pin.Output()
+	default:
+		return nil, fmt.Errorf("invalid type: %s", cc.Type)
+	}
 
 	return p, nil
 }
@@ -49,6 +59,10 @@ var _ BoolGetter = (*gpio)(nil)
 
 // BoolGetter returns GPIO pin active
 func (p *gpio) BoolGetter() (func() (bool, error), error) {
+	if p.typ != GpioTypeRead {
+		return nil, fmt.Errorf("invalid gpio type: %s", p.typ)
+	}
+
 	return func() (bool, error) {
 		p.mu.Lock()
 		defer p.mu.Unlock()
@@ -61,3 +75,27 @@ func (p *gpio) BoolGetter() (func() (bool, error), error) {
 		return p.pin.Read() != rpio.Low, nil
 	}, nil
 }
+
+var _ BoolSetter = (*gpio)(nil)
+
+// BoolSetter returns GPIO pin active
+func (p *gpio) BoolSetter(_ string) (func(bool) error, error) {
+	if p.typ != GpioTypeWrite {
+		return nil, fmt.Errorf("invalid gpio type: %s", p.typ)
+	}
+
+	return func(b bool) error {
+		p.mu.Lock()
+		defer p.mu.Unlock()
+
+		if err := rpio.Open(); err != nil {
+			return fmt.Errorf("failed to open GPIO: %w", err)
+		}
+		defer rpio.Close()
+
+		val := map[bool]rpio.State{false: rpio.Low, true: rpio.High}[b]
+		p.pin.Write(val)
+
+		return nil
+	}, nil
+}

plugin/gpiotype.go

@@ -0,0 +1,9 @@
+package plugin
+
+type GpioType int
+
+//go:generate go tool enumer -type GpioType -trimprefix GpioType -transform=lower -text
+const (
+	GpioTypeRead GpioType = iota
+	GpioTypeWrite
+)

plugin/gpiotype_enumer.go

@@ -0,0 +1,90 @@
+// Code generated by "enumer -type GpioType -trimprefix GpioType -transform=lower -text"; DO NOT EDIT.
+
+package plugin
+
+import (
+	"fmt"
+	"strings"
+)
+
+const _GpioTypeName = "readwrite"
+
+var _GpioTypeIndex = [...]uint8{0, 4, 9}
+
+const _GpioTypeLowerName = "readwrite"
+
+func (i GpioType) String() string {
+	if i < 0 || i >= GpioType(len(_GpioTypeIndex)-1) {
+		return fmt.Sprintf("GpioType(%d)", i)
+	}
+	return _GpioTypeName[_GpioTypeIndex[i]:_GpioTypeIndex[i+1]]
+}
+
+// An "invalid array index" compiler error signifies that the constant values have changed.
+// Re-run the stringer command to generate them again.
+func _GpioTypeNoOp() {
+	var x [1]struct{}
+	_ = x[GpioTypeRead-(0)]
+	_ = x[GpioTypeWrite-(1)]
+}
+
+var _GpioTypeValues = []GpioType{GpioTypeRead, GpioTypeWrite}
+
+var _GpioTypeNameToValueMap = map[string]GpioType{
+	_GpioTypeName[0:4]:      GpioTypeRead,
+	_GpioTypeLowerName[0:4]: GpioTypeRead,
+	_GpioTypeName[4:9]:      GpioTypeWrite,
+	_GpioTypeLowerName[4:9]: GpioTypeWrite,
+}
+
+var _GpioTypeNames = []string{
+	_GpioTypeName[0:4],
+	_GpioTypeName[4:9],
+}
+
+// GpioTypeString retrieves an enum value from the enum constants string name.
+// Throws an error if the param is not part of the enum.
+func GpioTypeString(s string) (GpioType, error) {
+	if val, ok := _GpioTypeNameToValueMap[s]; ok {
+		return val, nil
+	}
+
+	if val, ok := _GpioTypeNameToValueMap[strings.ToLower(s)]; ok {
+		return val, nil
+	}
+	return 0, fmt.Errorf("%s does not belong to GpioType values", s)
+}
+
+// GpioTypeValues returns all values of the enum
+func GpioTypeValues() []GpioType {
+	return _GpioTypeValues
+}
+
+// GpioTypeStrings returns a slice of all String values of the enum
+func GpioTypeStrings() []string {
+	strs := make([]string, len(_GpioTypeNames))
+	copy(strs, _GpioTypeNames)
+	return strs
+}
+
+// IsAGpioType returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i GpioType) IsAGpioType() bool {
+	for _, v := range _GpioTypeValues {
+		if i == v {
+			return true
+		}
+	}
+	return false
+}
+
+// MarshalText implements the encoding.TextMarshaler interface for GpioType
+func (i GpioType) MarshalText() ([]byte, error) {
+	return []byte(i.String()), nil
+}
+
+// UnmarshalText implements the encoding.TextUnmarshaler interface for GpioType
+func (i *GpioType) UnmarshalText(text []byte) error {
+	var err error
+	*i, err = GpioTypeString(string(text))
+	return err
+}