Show charging speed on Keyguard

Bug: 8099739
Change-Id: I2e5c21dd7ec028ce47fb03ab71e74f7fccaa9e36
diff --git a/healthd/BatteryMonitor.cpp b/healthd/BatteryMonitor.cpp
index 7ea8250..c75ed13 100644
--- a/healthd/BatteryMonitor.cpp
+++ b/healthd/BatteryMonitor.cpp
@@ -181,6 +181,7 @@
     props.chargerWirelessOnline = false;
     props.batteryStatus = BATTERY_STATUS_UNKNOWN;
     props.batteryHealth = BATTERY_HEALTH_UNKNOWN;
+    props.maxChargingCurrent = 0;
 
     if (!mHealthdConfig->batteryPresentPath.isEmpty())
         props.batteryPresent = getBooleanField(mHealthdConfig->batteryPresentPath);
@@ -235,6 +236,15 @@
                     KLOG_WARNING(LOG_TAG, "%s: Unknown power supply type\n",
                                  mChargerNames[i].string());
                 }
+                path.clear();
+                path.appendFormat("%s/%s/current_max", POWER_SUPPLY_SYSFS_PATH,
+                                  mChargerNames[i].string());
+                if (access(path.string(), R_OK) == 0) {
+                    int maxChargingCurrent = getIntField(path);
+                    if (props.maxChargingCurrent < maxChargingCurrent) {
+                        props.maxChargingCurrent = maxChargingCurrent;
+                    }
+                }
             }
         }
     }
@@ -341,9 +351,9 @@
     int v;
     char vs[128];
 
-    snprintf(vs, sizeof(vs), "ac: %d usb: %d wireless: %d\n",
+    snprintf(vs, sizeof(vs), "ac: %d usb: %d wireless: %d current_max: %d\n",
              props.chargerAcOnline, props.chargerUsbOnline,
-             props.chargerWirelessOnline);
+             props.chargerWirelessOnline, props.maxChargingCurrent);
     write(fd, vs, strlen(vs));
     snprintf(vs, sizeof(vs), "status: %d health: %d present: %d\n",
              props.batteryStatus, props.batteryHealth, props.batteryPresent);