Power improvements (#114)

TactilityHeadless/Source/hal/Configuration.h

@@ -16,6 +16,7 @@ class Display;
 class Keyboard;
 typedef Display* (*CreateDisplay)();
 typedef Keyboard* (*CreateKeyboard)();
+typedef std::shared_ptr<Power> (*CreatePower)();
 
 struct Configuration {
     /**
@@ -53,7 +54,7 @@ struct Configuration {
     /**
      * An optional power interface for battery or other power delivery.
      */
-    const Power* _Nullable power = nullptr;
+    const CreatePower _Nullable power = nullptr;
 
     /**
      * A list of i2c devices (can be empty, but preferably accurately represents the device capabilities)

TactilityHeadless/Source/hal/Power.h

@@ -4,18 +4,38 @@
 
 namespace tt::hal {
 
-typedef bool (*PowerIsCharging)();
-typedef bool (*PowerIsChargingEnabled)();
-typedef void (*PowerSetChargingEnabled)(bool enabled);
-typedef uint8_t (*PowerGetBatteryCharge)(); // Power value [0, 255] which maps to 0-100% charge
-typedef int32_t (*PowerGetCurrent)(); // Consumption or charge current in mAh
+class Power{
 
-typedef struct {
-    PowerIsCharging isCharging;
-    PowerIsChargingEnabled isChargingEnabled;
-    PowerSetChargingEnabled setChargingEnabled;
-    PowerGetBatteryCharge getChargeLevel;
-    PowerGetCurrent getCurrent;
-} Power;
+public:
+
+    Power() = default;
+    virtual ~Power() = default;
+
+    enum MetricType {
+        IS_CHARGING, // bool
+        CURRENT, // int32_t, mAh
+        BATTERY_VOLTAGE, // uint32_t, mV
+        CHARGE_LEVEL, // uint8_t [0, 100]
+    };
+
+    union MetricData {
+        int32_t valueAsInt32 = 0;
+        uint32_t valueAsUint32;
+        uint8_t valueAsUint8;
+        float valueAsFloat;
+        bool valueAsBool;
+    };
+
+    virtual bool supportsMetric(MetricType type) const = 0;
+
+    /**
+     * @return false when metric is not supported or (temporarily) not available.
+     */
+    virtual bool getMetric(Power::MetricType type, MetricData& data) = 0;
+
+    virtual bool supportsChargeControl() const { return false; }
+    virtual bool isAllowedToCharge() const { return false; }
+    virtual void setAllowedToCharge(bool canCharge) { /* NO-OP*/ }
+};
 
 } // namespace tt