Add GPIO plugin (#25806)

api/error.go

@@ -8,7 +8,10 @@ import (
 )
 
 // ErrNotAvailable indicates that a feature is not available
-var ErrNotAvailable = errors.New("not available")
+var ErrNotAvailable = backoff.Permanent(errors.New("not available"))
+
+// ErrUnsupportedPlatform indicates unsupported hardware platform
+var ErrUnsupportedPlatform error = backoff.Permanent(errors.New("unsupported platform"))
 
 // ErrMustRetry indicates that a rate-limited operation should be retried
 var ErrMustRetry = errors.New("must retry")

charger/openwb-native.go

@@ -4,7 +4,6 @@ package charger
 
 import (
 	"context"
-	"errors"
 
 	"github.com/evcc-io/evcc/api"
 )
@@ -15,5 +14,5 @@ func init() {
 
 // NewOpenWbNativeFromConfig creates an OpenWbNative DIN charger from generic config
 func NewOpenWbNativeFromConfig(ctx context.Context, other map[string]any) (api.Charger, error) {
-	return nil, errors.New("unsupported platform")
+	return nil, api.ErrUnsupportedPlatform
 }

charger/openwb-native_linux.go

@@ -108,20 +108,12 @@ func NewOpenWbNative(ctx context.Context, uri, device, comset string, baudrate i
 	if err := rpio.Open(); err != nil {
 		return nil, fmt.Errorf("failed to open GPIO: %w", err)
 	}
+	defer rpio.Close()
 
 	for _, pin := range structs.Fields(native.ChargePoints[connector-1]) {
 		rpio.Pin(pin.Value().(int)).Output()
 	}
 
-	// close GPIO when context is cancelled
-	go func() {
-		<-ctx.Done()
-		log.DEBUG.Println("context canceled, closing GPIO")
-		if err := rpio.Close(); err != nil {
-			log.ERROR.Printf("error closing GPIO: %v", err)
-		}
-	}()
-
 	return decorateOpenWbNative(wb, phases1p3p, identify), nil
 }
 
@@ -160,6 +152,11 @@ func (wb *OpenWbNative) WakeUp() error {
 
 // runGpioSequence executes a sequence of GPIO operations
 func (wb *OpenWbNative) runGpioSequence(seq []gpioAction) error {
+	if err := rpio.Open(); err != nil {
+		return fmt.Errorf("failed to open GPIO: %w", err)
+	}
+	defer rpio.Close()
+
 	if err := wb.Enable(false); err != nil {
 		return err
 	}

plugin/gpio.go

@@ -0,0 +1,18 @@
+//go:build !linux
+
+package plugin
+
+import (
+	"context"
+
+	"github.com/evcc-io/evcc/api"
+)
+
+func init() {
+	registry.AddCtx("gpio", NewGpioPluginFromConfig)
+}
+
+// NewGpioPluginFromConfig creates a GPIO provider
+func NewGpioPluginFromConfig(ctx context.Context, other map[string]any) (Plugin, error) {
+	return nil, api.ErrUnsupportedPlatform
+}

plugin/gpio_linux.go

@@ -0,0 +1,63 @@
+//go:build linux
+
+package plugin
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"github.com/evcc-io/evcc/util"
+	"github.com/stianeikeland/go-rpio/v4"
+)
+
+func init() {
+	registry.AddCtx("gpio", NewGpioPluginFromConfig)
+}
+
+type gpio struct {
+	mu  sync.Mutex
+	pin rpio.Pin
+}
+
+// NewGpioPluginFromConfig creates a GPIO provider
+func NewGpioPluginFromConfig(ctx context.Context, other map[string]any) (Plugin, error) {
+	var cc struct {
+		Pin int
+	}
+
+	if err := util.DecodeOther(other, &cc); err != nil {
+		return nil, err
+	}
+
+	p := &gpio{
+		pin: rpio.Pin(cc.Pin),
+	}
+
+	// initialize GPIO and set pins to input
+	if err := rpio.Open(); err != nil {
+		return nil, fmt.Errorf("failed to open GPIO: %w", err)
+	}
+	defer rpio.Close()
+
+	p.pin.Input()
+
+	return p, nil
+}
+
+var _ BoolGetter = (*gpio)(nil)
+
+// BoolGetter returns GPIO pin active
+func (p *gpio) BoolGetter() (func() (bool, error), error) {
+	return func() (bool, error) {
+		p.mu.Lock()
+		defer p.mu.Unlock()
+
+		if err := rpio.Open(); err != nil {
+			return false, fmt.Errorf("failed to open GPIO: %w", err)
+		}
+		defer rpio.Close()
+
+		return p.pin.Read() != rpio.Low, nil
+	}, nil
+}