healthd: Move power_supply attribute paths to healthd_config

Allow health HAL to select specific paths to be used, overriding
default search for arbitrary power supplies with the named paths.

Change-Id: I5f724739f58ef56087ab592b7403fc083db8f173
diff --git a/healthd/healthd.h b/healthd/healthd.h
index 895be40..5374fb1 100644
--- a/healthd/healthd.h
+++ b/healthd/healthd.h
@@ -18,6 +18,7 @@
 #define _HEALTHD_H_
 
 #include <batteryservice/BatteryService.h>
+#include <utils/String8.h>
 
 // periodic_chores_interval_fast, periodic_chores_interval_slow: intervals at
 // which healthd wakes up to poll health state and perform periodic chores,
@@ -32,18 +33,45 @@
 //    not connected to a charger (to watch for a battery drained to zero
 //    remaining capacity).  The default value is 600 (10 minutes).  Value -1
 //    tuns off periodic chores (and wakeups) in these conditions.
+//
+// power_supply sysfs attribute file paths.  Set these to specific paths
+// to use for the associated battery parameters.  healthd will search for
+// appropriate power_supply attribute files to use for any paths left empty:
+//
+//    batteryStatusPath: charging status (POWER_SUPPLY_PROP_STATUS)
+//    batteryHealthPath: battery health (POWER_SUPPLY_PROP_HEALTH)
+//    batteryPresentPath: battery present (POWER_SUPPLY_PROP_PRESENT)
+//    batteryCapacityPath: remaining capacity (POWER_SUPPLY_PROP_CAPACITY)
+//    batteryVoltagePath: battery voltage (POWER_SUPPLY_PROP_VOLTAGE_NOW)
+//    batteryTemperaturePath: battery temperature (POWER_SUPPLY_PROP_TEMP)
+//    batteryTechnologyPath: battery technology (POWER_SUPPLY_PROP_TECHNOLOGY)
+//    batteryCurrentNowPath: battery current (POWER_SUPPLY_PROP_CURRENT_NOW)
+//    batteryChargeCounterPath: battery accumulated charge
+//                                         (POWER_SUPPLY_PROP_CHARGE_COUNTER)
 
 struct healthd_config {
     int periodic_chores_interval_fast;
     int periodic_chores_interval_slow;
+
+    android::String8 batteryStatusPath;
+    android::String8 batteryHealthPath;
+    android::String8 batteryPresentPath;
+    android::String8 batteryCapacityPath;
+    android::String8 batteryVoltagePath;
+    android::String8 batteryTemperaturePath;
+    android::String8 batteryTechnologyPath;
+    android::String8 batteryCurrentNowPath;
+    android::String8 batteryChargeCounterPath;
 };
 
 // The following are implemented in libhealthd_board to handle board-specific
 // behavior.
 //
-//
-// To use the default values, this function can simply return without
-// modifying the parameters.
+// healthd_board_init() is called at startup time to modify healthd's
+// configuration according to board-specific requirements.  config
+// points to the healthd configuration values described above.  To use default
+// values, this function can simply return without modifying the fields of the
+// config parameter.
 
 void healthd_board_init(struct healthd_config *config);