headlight rework and laser addition

pi/roverd/gpio_toggle.go

@@ -0,0 +1,99 @@
+//go:build !dummy
+
+package roverd
+
+import (
+	"fmt"
+	"log"
+	"strings"
+	"sync"
+
+	gpiocdev "github.com/warthog618/go-gpiocdev"
+)
+
+type GPIOToggle struct {
+	cfg    GPIOToggleConfig
+	name   string
+	logger *log.Logger
+	line   *gpiocdev.Line
+	mu     sync.Mutex
+	on     bool
+	closed bool
+}
+
+func NewGPIOToggle(name string, cfg GPIOToggleConfig, logger *log.Logger) (*GPIOToggle, error) {
+	if !cfg.Enabled {
+		return nil, fmt.Errorf("%s disabled", name)
+	}
+	chip := cfg.GPIOChip
+	if chip == "" {
+		chip = "gpiochip0"
+	}
+	line, err := gpiocdev.RequestLine(
+		chip,
+		cfg.GPIOPin,
+		gpiocdev.AsOutput(cfg.LogicalToGPIO(cfg.InitialOn)),
+		gpiocdev.WithConsumer(fmt.Sprintf("roverd-%s", name)),
+	)
+	if err != nil {
+		return nil, fmt.Errorf("gpio request: %w", err)
+	}
+	toggle := &GPIOToggle{
+		cfg:    cfg,
+		name:   name,
+		logger: logger,
+		line:   line,
+		on:     cfg.InitialOn,
+	}
+	logger.Printf("%s on GPIO %d (initial=%v activeLow=%v)", name, cfg.GPIOPin, cfg.InitialOn, cfg.ActiveLow)
+	return toggle, nil
+}
+
+func (g *GPIOToggle) Close() {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	if g.closed {
+		return
+	}
+	// Preserve the last logical state while closing the line. The daemon is not
+	// trying to force a safety state here; it is only releasing the GPIO handle.
+	_ = g.line.SetValue(g.cfg.LogicalToGPIO(g.on))
+	g.line.Close()
+	g.closed = true
+}
+
+func (g *GPIOToggle) HandleAction(action string) error {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	if g.closed {
+		return fmt.Errorf("%s controller closed", g.name)
+	}
+	act := strings.ToLower(strings.TrimSpace(action))
+	switch act {
+	case "", "toggle":
+		return g.setLocked(!g.on)
+	case "on":
+		return g.setLocked(true)
+	case "off":
+		return g.setLocked(false)
+	default:
+		return fmt.Errorf("unknown action %q", action)
+	}
+}
+
+func (g *GPIOToggle) On() bool {
+	g.mu.Lock()
+	defer g.mu.Unlock()
+	return g.on
+}
+
+func (g *GPIOToggle) setLocked(on bool) error {
+	// This is the only place a logical device state becomes an electrical GPIO
+	// value. Hardware that turns on when pulled low sets activeLow in roverd
+	// config; every caller above this layer still uses plain on/off semantics.
+	if err := g.line.SetValue(g.cfg.LogicalToGPIO(on)); err != nil {
+		return err
+	}
+	g.on = on
+	return nil
+}