Add battery power API

backend/build.sh

@@ -6,7 +6,7 @@
 cargo build
 
 mkdir -p ../bin
-#cp ./target/x86_64-unknown-linux-musl/release/powertools ../bin/backend
-#cp ./target/x86_64-unknown-linux-musl/debug/powertools ../bin/backend
-#cp ./target/debug/powertools ../bin/backend
-cp ./target/debug/powertools ../bin/backend
+#cp --preserve=mode ./target/x86_64-unknown-linux-musl/release/powertools ../bin/backend
+#cp --preserve=mode ./target/x86_64-unknown-linux-musl/debug/powertools ../bin/backend
+#cp --preserve=mode ./target/debug/powertools ../bin/backend
+cp --preserve=mode ./target/debug/powertools ../bin/backend

backend/src/settings/generic/battery.rs

@@ -129,6 +129,10 @@ impl TBattery for Battery {
         None
     }
 
+    fn read_charge_power(&self) -> Option<f64> {
+        None
+    }
+
     fn charge_limit(&mut self, _limit: Option<f64>) {}
 
     fn get_charge_limit(&self) -> Option<f64> {

backend/src/settings/steam_deck/battery.rs

@@ -320,6 +320,12 @@ impl Battery {
         }
     }
 
+    pub fn read_charge_power() -> Result<f64, SettingError> {
+        let current = Self::read_current_now()? as f64 / 1000.0; // mA -> A
+        let voltage = Self::read_usb_voltage()?;
+        Ok(current * voltage)
+    }
+
     pub fn read_charge_now() -> Result<f64, SettingError> {
         match usdpl_back::api::files::read_single::<_, u64, _>(BATTERY_CHARGE_NOW_PATH) {
             Err(e) => Err(SettingError {
@@ -552,6 +558,16 @@ impl TBattery for Battery {
         }
     }
 
+    fn read_charge_power(&self) -> Option<f64> {
+        match Self::read_charge_power() {
+            Ok(x) => Some(x as f64),
+            Err(e) => {
+                log::warn!("read_current_now err: {}", e.msg);
+                None
+            }
+        }
+    }
+
     fn charge_limit(&mut self, limit: Option<f64>) {
         // upper limit
         let index = self.find_limit_event();

backend/src/settings/traits.rs

@@ -129,6 +129,8 @@ pub trait TBattery: OnSet + OnResume + OnPowerEvent + Debug + Send {
 
     fn read_current_now(&self) -> Option<f64>;
 
+    fn read_charge_power(&self) -> Option<f64>;
+
     fn charge_limit(&mut self, limit: Option<f64>);
 
     fn get_charge_limit(&self) -> Option<f64>;

backend/src/settings/unknown/battery.rs

@@ -75,6 +75,10 @@ impl TBattery for Battery {
         None
     }
 
+    fn read_charge_power(&self) -> Option<f64> {
+        None
+    }
+
     fn charge_limit(&mut self, _limit: Option<f64>) {}
 
     fn get_charge_limit(&self) -> Option<f64> {