Android->usb_mode_switch: add switch to control otg mode.One bug need to be solved:it must to reconnect usb wire that windows system can discover device while rk3399-aio don't have such problem

device/rockchip/common/init.rk30board.rc

@@ -111,12 +111,13 @@ on boot
 
     #add for usb otg by huangjc
     chown system system /sys/bus/platform/drivers/usb20_otg/force_usb_mode
-    chmod 0664 /sys/bus/platform/drivers/usb20_otg/force_usb_mode
+    chmod 0666 /sys/bus/platform/drivers/usb20_otg/force_usb_mode
 
 # cpu min freq must change to 126M when boot completed
 on property:sys.boot_completed=1
     write /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq 0
     setprop persist.sys.first_booting false
+    start mode_switch
 
 # for telephony function
 on property:ro.boot.baseband=N/A
@@ -133,6 +134,12 @@ service pppoe_start /system/bin/pppoe-start
     disabled
     oneshot
 
+service mode_switch /system/bin/usb_mode_switch.sh
+    seclabel u:r:install_recovery:s0
+    disabled
+    oneshot
+    #disabled
+
 service bplus_helper  /system/bin/bplus_helper
     class main
     oneshot

packages/apps/Settings/src/com/android/settings/UsbSetting.java

@@ -34,6 +34,7 @@ import android.net.Uri;
 import android.os.Bundle;
 import android.os.Handler;
 import android.os.Message;
+import android.os.SystemProperties;
 import android.preference.CheckBoxPreference;
 import android.preference.ListPreference;
 import android.preference.Preference;
@@ -61,12 +62,16 @@ public class UsbSetting extends SettingsPreferenceFragment implements
     private CheckBoxPreference mConnectToPc;
     private File mFile = null;
     private String mMode = null;
+    private static final String OTG_MODE = "0";
     private static final String	HOST_MODE = new String("1");
     private static final String	SLAVE_MODE = new String("2");
-
+    private static final String OTG_MODE_STR = "otg";
+    private static final String HOST_MODE_STR = "host";
+    private static final String SLAVE_MODE_STR = "peripheral";
     private Handler mHandler;
     private static final String KEY_CONNECT_TO_PC = "connect_to_pc";
     private static final String SYS_FILE = "/sys/bus/platform/drivers/usb20_otg/force_usb_mode";
+    public static final String PERSIST_PRO = "persist.usb.mode";
 
     private BroadcastReceiver mReceiver = new BroadcastReceiver() {
         @Override
@@ -104,6 +109,8 @@ public class UsbSetting extends SettingsPreferenceFragment implements
                     } else if(SLAVE_MODE.equals(mode)) {
                         mConnectToPc.setChecked(true);
                     }
+
+                    SystemProperties.set(PERSIST_PRO, mode);
                 } else {
                     Log.e(TAG, "unexpect msg:"+ msg.what);
                 }
@@ -118,6 +125,16 @@ public class UsbSetting extends SettingsPreferenceFragment implements
                 BufferedReader reader= new BufferedReader(new InputStreamReader(fin));
                 String config = reader.readLine();
                 fin.close();
+
+                Log.d(TAG, "Usb mode: " + config);
+                if (HOST_MODE_STR.equals(config)) {
+                    config = HOST_MODE;
+                } else if (SLAVE_MODE_STR.equals(config)) {
+                    config = SLAVE_MODE;
+                } else if (OTG_MODE_STR.equals(config)) {
+                    config = OTG_MODE;
+                }
+
                 return config;
             } catch(IOException e) {
                 e.printStackTrace();
@@ -154,9 +171,9 @@ public class UsbSetting extends SettingsPreferenceFragment implements
                     mConnectToPc.setChecked(false);
                 } else if(SLAVE_MODE.equals(mMode)) {
                     mConnectToPc.setChecked(true);
-                } else if ("0".equals(mMode)) {
+                } else if (OTG_MODE.equals(mMode)) {
                     mConnectToPc.setChecked(true);
-                    Write2File(mFile, "2");
+                    Write2File(mFile, SLAVE_MODE);
                 }
                 mConnectToPc.setEnabled(true);
             }

system/core/include/private/android_filesystem_config.h

@@ -238,7 +238,7 @@ static const struct fs_path_config android_files[] = {
     { 00644, AID_APP,       AID_APP,       0, "data/data/*" },
     { 00755, AID_ROOT,      AID_ROOT,      0, "system/bin/ping" },
     { 00766, AID_SYSTEM,    AID_SYSTEM,    0, "system/bin/displayd" },
-
+    { 00755, AID_ROOT,      AID_ROOT,      0, "system/bin/usb_mode_switch.sh" },
     /* the following file is INTENTIONALLY set-gid and not set-uid.
      * Do not change. */
     { 02750, AID_ROOT,      AID_INET,      0, "system/bin/netcfg" },

vendor/rockchip/firefly/firefly.mk

@@ -3,3 +3,4 @@ CUR_PATH := vendor/rockchip/firefly/
 -include $(CUR_PATH)/catlog/catlog.mk
 -include $(CUR_PATH)/hdmiin/hdmiin.mk
 include $(CUR_PATH)/apps/apps.mk
+include $(CUR_PATH)/usb_mode_switch/usb_mode_switch.mk

vendor/rockchip/firefly/usb_mode_switch/usb_mode_switch.mk

@@ -0,0 +1 @@
+PRODUCT_COPY_FILES +=vendor/rockchip/firefly/usb_mode_switch/usb_mode_switch.sh:system/bin/usb_mode_switch.sh

vendor/rockchip/firefly/usb_mode_switch/usb_mode_switch.sh

@@ -0,0 +1,9 @@
+#!/system/bin/sh
+FILE_USB_MODE="/sys/bus/platform/drivers/usb20_otg/force_usb_mode"
+MODE=$(getprop persist.usb.mode)
+
+if [ -z "$MODE" ];then
+    MODE="host";
+fi
+
+[ -e "$FILE_USB_MODE" ] &&  echo  "$MODE" > "$FILE_USB_MODE"