| /* |
| * 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(); |
| } |
| } |