services/core/java/com/android/server/ExtconUEventObserver.java - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2018 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package com.android.server;

 import android.annotation.Nullable;
 import android.annotation.StringDef;
 import android.os.FileUtils;
 import android.os.UEventObserver;
 import android.text.TextUtils;
 import android.util.ArrayMap;
 import android.util.Slog;
 import com.android.internal.annotations.GuardedBy;
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;

 /**
  * A specialized UEventObserver that receives UEvents from the kernel for devices in the {@code
  * /sys/class/extcon}. directory
  *
  * <p>Subclass ExtconUEventObserver, implementing {@link #onUEvent(ExtconInfo, UEvent)}, then call
  * startObserving() with a ExtconInfo to observe. The UEvent thread will then call your onUEvent()
  * method when a UEvent occurs that matches the path of your ExtconInfos.
  *
  * <p>Call stopObserving() to stop receiving UEvents.
  *
  * <p>There is only one UEvent thread per process, even if that process has multiple UEventObserver
  * subclass instances. The UEvent thread starts when the startObserving() is called for the first
  * time in that process. Once started the UEvent thread will not stop (although it can stop
  * notifying UEventObserver's via stopObserving()).
  *
  * @hide
  */
 public abstract class ExtconUEventObserver extends UEventObserver {
     private static final String TAG = "ExtconUEventObserver";
     private static final boolean LOG = false;
     private static final String SELINUX_POLICIES_NEED_TO_BE_CHANGED =
             "This probably means the selinux policies need to be changed.";

     private final Map<String, ExtconInfo> mExtconInfos = new ArrayMap<>();

     @Override
     public final void onUEvent(UEvent event) {
         String devPath = event.get("DEVPATH");
         ExtconInfo info = mExtconInfos.get(devPath);
         if (info != null) {
             onUEvent(info, event);
         } else {
             Slog.w(TAG, "No match found for DEVPATH of " + event + " in " + mExtconInfos);
         }
     }

     /**
      * Subclasses of ExtconUEventObserver should override this method to handle UEvents.
      *
      * @param extconInfo that matches the {@code DEVPATH} of {@code event}
      * @param event      the event
      */
     protected abstract void onUEvent(ExtconInfo extconInfo, UEvent event);

     /** Starts observing {@link ExtconInfo#getDevicePath()}. */
     public void startObserving(ExtconInfo extconInfo) {
         String devicePath = extconInfo.getDevicePath();
         if (devicePath == null) {
             Slog.wtf(TAG, "Unable to start observing  " + extconInfo.getName()
                     + " because the device path is null. " + SELINUX_POLICIES_NEED_TO_BE_CHANGED);
         } else {
             mExtconInfos.put(devicePath, extconInfo);
             if (LOG) Slog.v(TAG, "Observing  " + devicePath);
             startObserving("DEVPATH=" + devicePath);
         }
     }

     /** An External Connection to watch. */
     public static final class ExtconInfo {
         /* Copied from drivers/extcon/extcon.c */

         /* USB external connector */
         public static final String EXTCON_USB = "USB";
         public static final String EXTCON_USB_HOST = "USB-HOST";

         /* Charger external connector */
         public static final String EXTCON_TA = "TA";
         public static final String EXTCON_FAST_CHARGER = "FAST-CHARGER";
         public static final String EXTCON_SLOW_CHARGER = "SLOW-CHARGER";
         public static final String EXTCON_CHARGE_DOWNSTREAM = "CHARGE-DOWNSTREAM";

         /* Audio/Video external connector */
         public static final String EXTCON_LINE_IN = "LINE-IN";
         public static final String EXTCON_LINE_OUT = "LINE-OUT";
         public static final String EXTCON_MICROPHONE = "MICROPHONE";
         public static final String EXTCON_HEADPHONE = "HEADPHONE";

         public static final String EXTCON_HDMI = "HDMI";
         public static final String EXTCON_MHL = "MHL";
         public static final String EXTCON_DVI = "DVI";
         public static final String EXTCON_VGA = "VGA";
         public static final String EXTCON_SPDIF_IN = "SPDIF-IN";
         public static final String EXTCON_SPDIF_OUT = "SPDIF-OUT";
         public static final String EXTCON_VIDEO_IN = "VIDEO-IN";
         public static final String EXTCON_VIDEO_OUT = "VIDEO-OUT";

         /* Etc external connector */
         public static final String EXTCON_DOCK = "DOCK";
         public static final String EXTCON_JIG = "JIG";
         public static final String EXTCON_MECHANICAL = "MECHANICAL";

         @StringDef({
                 EXTCON_USB,
                 EXTCON_USB_HOST,
                 EXTCON_TA,
                 EXTCON_FAST_CHARGER,
                 EXTCON_SLOW_CHARGER,
                 EXTCON_CHARGE_DOWNSTREAM,
                 EXTCON_LINE_IN,
                 EXTCON_LINE_OUT,
                 EXTCON_MICROPHONE,
                 EXTCON_HEADPHONE,
                 EXTCON_HDMI,
                 EXTCON_MHL,
                 EXTCON_DVI,
                 EXTCON_VGA,
                 EXTCON_SPDIF_IN,
                 EXTCON_SPDIF_OUT,
                 EXTCON_VIDEO_IN,
                 EXTCON_VIDEO_OUT,
                 EXTCON_DOCK,
                 EXTCON_JIG,
                 EXTCON_MECHANICAL,
         })

         public @interface ExtconDeviceType {}

         private static final Object sLock = new Object();
         private static ExtconInfo[] sExtconInfos = null;

         private final String mName;
         private final @ExtconDeviceType HashSet<String> mDeviceTypes = new HashSet<>();

         @GuardedBy("sLock")
         private static void initExtconInfos() {
             if (sExtconInfos != null) {
                 return;
             }

             File file = new File("/sys/class/extcon");
             File[] files = file.listFiles();
             if (files == null) {
                 Slog.w(TAG,
                         file + " exists " + file.exists() + " isDir " + file.isDirectory()
                                 + " but listFiles returns null."
                                 + SELINUX_POLICIES_NEED_TO_BE_CHANGED);
                 sExtconInfos = new ExtconInfo[0];
             } else {
                 List<ExtconInfo> list = new ArrayList<>(files.length);
                 for (File f : files) {
                     list.add(new ExtconInfo(f.getName()));
                 }
                 sExtconInfos = list.toArray(new ExtconInfo[0]);
             }
         }

         /**
          * Returns a new list of all external connections for the types given.
          */
         public static List<ExtconInfo> getExtconInfoForTypes(
                 @ExtconDeviceType String[] extconTypes) {
             synchronized (sLock) {
                 initExtconInfos();
             }

             List<ExtconInfo> extcons = new ArrayList<ExtconInfo>();
             for (ExtconInfo extcon : sExtconInfos) {
                 for (String type : extconTypes) {
                     if (extcon.hasCableType(type)) {
                         extcons.add(extcon);
                         break;
                     }
                 }
             }

             return extcons;
         }

         /** True if the given type is supported */
         public boolean hasCableType(@ExtconDeviceType String type) {
             return mDeviceTypes.contains(type);
         }

         private ExtconInfo(String extconName) {
             mName = extconName;

             // Retrieve device types from /sys/class/extcon/extcon[X]/cable.[Y]/name
             File[] cableDirs = FileUtils.listFilesOrEmpty(new File("/sys/class/extcon", mName),
                     (dir, cable) -> cable.startsWith("cable."));
             if (cableDirs.length == 0) {
                 Slog.d(TAG,
                         "Unable to list cables in /sys/class/extcon/" + mName + ". "
                                 + SELINUX_POLICIES_NEED_TO_BE_CHANGED);
             }

             for (File cableDir : cableDirs) {
                 String cableCanonicalPath = null;
                 try {
                     cableCanonicalPath = cableDir.getCanonicalPath();
                     String name = FileUtils.readTextFile(new File(cableDir, "name"), 0, null);
                     name = name.replace("\n", "").replace("\r", "");
                     if (LOG) {
                         Slog.v(TAG, "Add extcon cable " + cableCanonicalPath);
                     }
                     mDeviceTypes.add(name);
                 } catch (IOException ex) {
                     Slog.w(TAG,
                             "Unable to read " + cableCanonicalPath + "/name. "
                                     + SELINUX_POLICIES_NEED_TO_BE_CHANGED,
                             ex);
                 }
             }
         }

         /** The name of the external connection */
         public String getName() {
             return mName;
         }

         /**
          * The path to the device for this external connection.
          *
          * <p><b>NOTE</b> getting this path involves resolving a symlink.
          *
          * @return the device path, or null if it not found.
          */
         @Nullable
         public String getDevicePath() {
             try {
                 String extconPath = TextUtils.formatSimple("/sys/class/extcon/%s", mName);
                 File devPath = new File(extconPath);
                 if (devPath.exists()) {
                     String canonicalPath = devPath.getCanonicalPath();
                     int start = canonicalPath.indexOf("/devices");
                     return canonicalPath.substring(start);
                 }
                 return null;
             } catch (IOException e) {
                 Slog.e(TAG, "Could not get the extcon device path for " + mName, e);
                 return null;
             }
         }

         /** The path to the state file */
         public String getStatePath() {
             return TextUtils.formatSimple("/sys/class/extcon/%s/state", mName);
         }
     }

     /** Does the {@code /sys/class/extcon} directory exist */
     public static boolean extconExists() {
         File extconDir = new File("/sys/class/extcon");
         return extconDir.exists() && extconDir.isDirectory();
     }
 }
	/*
	* Copyright (C) 2018 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package com.android.server;

	import android.annotation.Nullable;
	import android.annotation.StringDef;
	import android.os.FileUtils;
	import android.os.UEventObserver;
	import android.text.TextUtils;
	import android.util.ArrayMap;
	import android.util.Slog;
	import com.android.internal.annotations.GuardedBy;
	import java.io.File;
	import java.io.IOException;
	import java.util.ArrayList;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;

	/**
	* A specialized UEventObserver that receives UEvents from the kernel for devices in the {@code
	* /sys/class/extcon}. directory
	*
	* <p>Subclass ExtconUEventObserver, implementing {@link #onUEvent(ExtconInfo, UEvent)}, then call
	* startObserving() with a ExtconInfo to observe. The UEvent thread will then call your onUEvent()
	* method when a UEvent occurs that matches the path of your ExtconInfos.
	*
	* <p>Call stopObserving() to stop receiving UEvents.
	*
	* <p>There is only one UEvent thread per process, even if that process has multiple UEventObserver
	* subclass instances. The UEvent thread starts when the startObserving() is called for the first
	* time in that process. Once started the UEvent thread will not stop (although it can stop
	* notifying UEventObserver's via stopObserving()).
	*
	* @hide
	*/
	public abstract class ExtconUEventObserver extends UEventObserver {
	private static final String TAG = "ExtconUEventObserver";
	private static final boolean LOG = false;
	private static final String SELINUX_POLICIES_NEED_TO_BE_CHANGED =
	"This probably means the selinux policies need to be changed.";

	private final Map<String, ExtconInfo> mExtconInfos = new ArrayMap<>();

	@Override
	public final void onUEvent(UEvent event) {
	String devPath = event.get("DEVPATH");
	ExtconInfo info = mExtconInfos.get(devPath);
	if (info != null) {
	onUEvent(info, event);
	} else {
	Slog.w(TAG, "No match found for DEVPATH of " + event + " in " + mExtconInfos);
	}
	}

	/**
	* Subclasses of ExtconUEventObserver should override this method to handle UEvents.
	*
	* @param extconInfo that matches the {@code DEVPATH} of {@code event}
	* @param event the event
	*/
	protected abstract void onUEvent(ExtconInfo extconInfo, UEvent event);

	/** Starts observing {@link ExtconInfo#getDevicePath()}. */
	public void startObserving(ExtconInfo extconInfo) {
	String devicePath = extconInfo.getDevicePath();
	if (devicePath == null) {
	Slog.wtf(TAG, "Unable to start observing " + extconInfo.getName()
	+ " because the device path is null. " + SELINUX_POLICIES_NEED_TO_BE_CHANGED);
	} else {
	mExtconInfos.put(devicePath, extconInfo);
	if (LOG) Slog.v(TAG, "Observing " + devicePath);
	startObserving("DEVPATH=" + devicePath);
	}
	}

	/** An External Connection to watch. */
	public static final class ExtconInfo {
	/* Copied from drivers/extcon/extcon.c */

	/* USB external connector */
	public static final String EXTCON_USB = "USB";
	public static final String EXTCON_USB_HOST = "USB-HOST";

	/* Charger external connector */
	public static final String EXTCON_TA = "TA";
	public static final String EXTCON_FAST_CHARGER = "FAST-CHARGER";
	public static final String EXTCON_SLOW_CHARGER = "SLOW-CHARGER";
	public static final String EXTCON_CHARGE_DOWNSTREAM = "CHARGE-DOWNSTREAM";

	/* Audio/Video external connector */
	public static final String EXTCON_LINE_IN = "LINE-IN";
	public static final String EXTCON_LINE_OUT = "LINE-OUT";
	public static final String EXTCON_MICROPHONE = "MICROPHONE";
	public static final String EXTCON_HEADPHONE = "HEADPHONE";

	public static final String EXTCON_HDMI = "HDMI";
	public static final String EXTCON_MHL = "MHL";
	public static final String EXTCON_DVI = "DVI";
	public static final String EXTCON_VGA = "VGA";
	public static final String EXTCON_SPDIF_IN = "SPDIF-IN";
	public static final String EXTCON_SPDIF_OUT = "SPDIF-OUT";
	public static final String EXTCON_VIDEO_IN = "VIDEO-IN";
	public static final String EXTCON_VIDEO_OUT = "VIDEO-OUT";

	/* Etc external connector */
	public static final String EXTCON_DOCK = "DOCK";
	public static final String EXTCON_JIG = "JIG";
	public static final String EXTCON_MECHANICAL = "MECHANICAL";

	@StringDef({
	EXTCON_USB,
	EXTCON_USB_HOST,
	EXTCON_TA,
	EXTCON_FAST_CHARGER,
	EXTCON_SLOW_CHARGER,
	EXTCON_CHARGE_DOWNSTREAM,
	EXTCON_LINE_IN,
	EXTCON_LINE_OUT,
	EXTCON_MICROPHONE,
	EXTCON_HEADPHONE,
	EXTCON_HDMI,
	EXTCON_MHL,
	EXTCON_DVI,
	EXTCON_VGA,
	EXTCON_SPDIF_IN,
	EXTCON_SPDIF_OUT,
	EXTCON_VIDEO_IN,
	EXTCON_VIDEO_OUT,
	EXTCON_DOCK,
	EXTCON_JIG,
	EXTCON_MECHANICAL,
	})

	public @interface ExtconDeviceType {}

	private static final Object sLock = new Object();
	private static ExtconInfo[] sExtconInfos = null;

	private final String mName;
	private final @ExtconDeviceType HashSet<String> mDeviceTypes = new HashSet<>();

	@GuardedBy("sLock")
	private static void initExtconInfos() {
	if (sExtconInfos != null) {
	return;
	}

	File file = new File("/sys/class/extcon");
	File[] files = file.listFiles();
	if (files == null) {
	Slog.w(TAG,
	file + " exists " + file.exists() + " isDir " + file.isDirectory()
	+ " but listFiles returns null."
	+ SELINUX_POLICIES_NEED_TO_BE_CHANGED);
	sExtconInfos = new ExtconInfo[0];
	} else {
	List<ExtconInfo> list = new ArrayList<>(files.length);
	for (File f : files) {
	list.add(new ExtconInfo(f.getName()));
	}
	sExtconInfos = list.toArray(new ExtconInfo[0]);
	}
	}

	/**
	* Returns a new list of all external connections for the types given.
	*/
	public static List<ExtconInfo> getExtconInfoForTypes(
	@ExtconDeviceType String[] extconTypes) {
	synchronized (sLock) {
	initExtconInfos();
	}

	List<ExtconInfo> extcons = new ArrayList<ExtconInfo>();
	for (ExtconInfo extcon : sExtconInfos) {
	for (String type : extconTypes) {
	if (extcon.hasCableType(type)) {
	extcons.add(extcon);
	break;
	}
	}
	}

	return extcons;
	}

	/** True if the given type is supported */
	public boolean hasCableType(@ExtconDeviceType String type) {
	return mDeviceTypes.contains(type);
	}

	private ExtconInfo(String extconName) {
	mName = extconName;

	// Retrieve device types from /sys/class/extcon/extcon[X]/cable.[Y]/name
	File[] cableDirs = FileUtils.listFilesOrEmpty(new File("/sys/class/extcon", mName),
	(dir, cable) -> cable.startsWith("cable."));
	if (cableDirs.length == 0) {
	Slog.d(TAG,
	"Unable to list cables in /sys/class/extcon/" + mName + ". "
	+ SELINUX_POLICIES_NEED_TO_BE_CHANGED);
	}

	for (File cableDir : cableDirs) {
	String cableCanonicalPath = null;
	try {
	cableCanonicalPath = cableDir.getCanonicalPath();
	String name = FileUtils.readTextFile(new File(cableDir, "name"), 0, null);
	name = name.replace("\n", "").replace("\r", "");
	if (LOG) {
	Slog.v(TAG, "Add extcon cable " + cableCanonicalPath);
	}
	mDeviceTypes.add(name);
	} catch (IOException ex) {
	Slog.w(TAG,
	"Unable to read " + cableCanonicalPath + "/name. "
	+ SELINUX_POLICIES_NEED_TO_BE_CHANGED,
	ex);
	}
	}
	}

	/** The name of the external connection */
	public String getName() {
	return mName;
	}

	/**
	* The path to the device for this external connection.
	*
	* <p><b>NOTE</b> getting this path involves resolving a symlink.
	*
	* @return the device path, or null if it not found.
	*/
	@Nullable
	public String getDevicePath() {
	try {
	String extconPath = TextUtils.formatSimple("/sys/class/extcon/%s", mName);
	File devPath = new File(extconPath);
	if (devPath.exists()) {
	String canonicalPath = devPath.getCanonicalPath();
	int start = canonicalPath.indexOf("/devices");
	return canonicalPath.substring(start);
	}
	return null;
	} catch (IOException e) {
	Slog.e(TAG, "Could not get the extcon device path for " + mName, e);
	return null;
	}
	}

	/** The path to the state file */
	public String getStatePath() {
	return TextUtils.formatSimple("/sys/class/extcon/%s/state", mName);
	}
	}

	/** Does the {@code /sys/class/extcon} directory exist */
	public static boolean extconExists() {
	File extconDir = new File("/sys/class/extcon");
	return extconDir.exists() && extconDir.isDirectory();
	}
	}