linux: Fix batteries which report capacity, but not energy/charge

Many Android devices only export charge_full and capacity, but not charge_now
or energy_now. In that case, directly read the percentage (from the capacity
attribute) and calculate current energy from that.

Thanks to Seth Forshee for the original patch!

https://bugs.freedesktop.org/show_bug.cgi?id=68337

2 files changed, 36 insertions, 8 deletions

diff --git a/src/linux/integration-test b/src/linux/integration-test
index b80dd70..645cf92 100755
--- a/src/linux/integration-test
+++ b/src/linux/integration-test
@@ -408,6 +408,36 @@ class Tests(unittest.TestCase):
         self.assertEqual(self.get_dbus_dev_property(bat0_up, 'Percentage'), 40.0)
         self.stop_daemon()
 
+    def test_battery_capacity_and_charge(self):
+        '''battery which reports capacity and charge_full'''
+
+        bat0 = self.testbed.add_device('power_supply', 'BAT0', None,
+                ['type', 'Battery',
+                 'present', '1',
+                 'status', 'Discharging',
+                 'charge_full', '10500000',
+                 'charge_full_design', '11000000',
+                 'capacity', '40',
+                 'voltage_now', '12000000'], [])
+
+        self.start_daemon()
+        devs = self.proxy.EnumerateDevices()
+        self.assertEqual(len(devs), 1)
+        bat0_up = devs[0]
+
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'Percentage'), 40.0)
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'IsPresent'), True)
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'State'), UP_DEVICE_STATE_DISCHARGING)
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'Energy'), 50.4)
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'EnergyFull'), 126.0)
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'EnergyFullDesign'), 132.0)
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'Voltage'), 12.0)
+        self.assertEqual(self.get_dbus_dev_property(bat0_up, 'NativePath'), bat0)
+
+        self.assertEqual(self.get_dbus_property('OnBattery'), True)
+        #self.assertEqual(self.get_dbus_property('OnLowBattery'), False)
+        self.stop_daemon()
+
     def test_ups_ac(self):
         '''UPS properties with and without AC'''
 
diff --git a/src/linux/up-device-supply.c b/src/linux/up-device-supply.c
index bd54801..6a82721 100644
--- a/src/linux/up-device-supply.c
+++ b/src/linux/up-device-supply.c
@@ -693,7 +693,12 @@ up_device_supply_refresh_battery (UpDeviceSupply *supply)
 		energy_rate = up_device_supply_calculate_rate (supply, energy);
 
 	/* get a precise percentage */
-	if (energy_full > 0.0f) {
+        if (sysfs_file_exists (native_path, "capacity")) {
+		percentage = sysfs_get_double (native_path, "capacity");
+                /* for devices which provide capacity, but not {energy,charge}_now */
+                if (energy < 0.1f && energy_full > 0.0f)
+                    energy = energy_full * percentage / 100;
+        } else if (energy_full > 0.0f) {
 		percentage = 100.0 * energy / energy_full;
 		if (percentage < 0.0f)
 			percentage = 0.0f;
@@ -701,13 +706,6 @@ up_device_supply_refresh_battery (UpDeviceSupply *supply)
 			percentage = 100.0f;
 	}
 
-	/* device is a peripheral and not providing power to the computer */
-	if (energy < 0.01f &&
-	    energy_rate < 0.01f &&
-	    energy_full < 0.01f) {
-		percentage = sysfs_get_double (native_path, "capacity");
-	}
-
 	/* the battery isn't charging or discharging, it's just
 	 * sitting there half full doing nothing: try to guess a state */
 	if (state == UP_DEVICE_STATE_UNKNOWN) {