add cpu frequency driver

app/cpu/drivers/hwmon.go

@@ -0,0 +1,76 @@
+package drivers
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+type HwmonDriver struct {
+	hwmonDir    string
+	hwmonDriver string
+}
+
+func NewHwmonDriver(expectedDrivers []string) *HwmonDriver {
+	// Locate hwmon path
+	dirs, err := filepath.Glob("/sys/class/hwmon/hwmon*")
+	if err != nil {
+		return nil
+	}
+
+	for _, dir := range dirs {
+		nameRaw, err := os.ReadFile(filepath.Join(dir, "name"))
+		name := strings.TrimSpace(string(nameRaw))
+		if err == nil {
+			for _, driver := range expectedDrivers {
+				if driver == name {
+					return &HwmonDriver{
+						hwmonDir:    dir,
+						hwmonDriver: driver,
+					}
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+func (r *HwmonDriver) ReadTemperatureSensors() ([]TemperatureSensor, error) {
+	inputs, err := filepath.Glob(filepath.Join(r.hwmonDir, "temp*_input"))
+	if err != nil || len(inputs) == 0 {
+		return nil, fmt.Errorf("no temperature inputs found in %s", r.hwmonDir)
+	}
+
+	temps := make([]TemperatureSensor, 0, len(inputs))
+
+	for _, inputPath := range inputs {
+		valBytes, err := os.ReadFile(inputPath)
+		if err != nil {
+			continue
+		}
+
+		milliC, err := strconv.ParseFloat(strings.TrimSpace(string(valBytes)), 64)
+		if err != nil {
+			continue
+		}
+
+		labelPath := strings.TrimSuffix(inputPath, "_input") + "_label"
+		label := ""
+		if lBytes, err := os.ReadFile(labelPath); err == nil {
+			label = strings.TrimSpace(string(lBytes))
+		} else {
+			label = filepath.Base(strings.TrimSuffix(inputPath, "_input"))
+		}
+
+		temps = append(temps, TemperatureSensor{
+			path:  inputPath,
+			Name:  label,
+			TempC: milliC / 1000.0,
+		})
+	}
+
+	return temps, nil
+}