ui/events/devices/device_util_linux.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/events/devices/device_util_linux.h"
   6
   7 #include <string>
   8
   9 #include "base/files/file_enumerator.h"
  10 #include "base/files/file_path.h"
  11 #include "base/files/file_util.h"
  12 #include "base/message_loop/message_loop.h"
  13 #include "base/strings/string_util.h"
  14
  15 namespace ui {
  16
  17 InputDeviceType GetInputDeviceTypeFromPath(const base::FilePath& path) {
  18   DCHECK(!base::MessageLoopForUI::IsCurrent());
  19   std::string event_node = path.BaseName().value();
  20   if (event_node.empty() ||
  21       !base::StartsWith(event_node, "event",
  22                         base::CompareCase::INSENSITIVE_ASCII))
  23     return InputDeviceType::INPUT_DEVICE_UNKNOWN;
  24
  25   // Find sysfs device path for this device.
  26   base::FilePath sysfs_path =
  27       base::FilePath(FILE_PATH_LITERAL("/sys/class/input"));
  28   sysfs_path = sysfs_path.Append(path.BaseName());
  29   sysfs_path = base::MakeAbsoluteFilePath(sysfs_path);
  30
  31   // Device does not exist.
  32   if (sysfs_path.empty())
  33     return InputDeviceType::INPUT_DEVICE_UNKNOWN;
  34
  35   // Check ancestor devices for a known bus attachment.
  36   for (base::FilePath path = sysfs_path; path != base::FilePath("/");
  37        path = path.DirName()) {
  38     // Bluetooth LE devices are virtual "uhid" devices.
  39     if (path ==
  40         base::FilePath(FILE_PATH_LITERAL("/sys/devices/virtual/misc/uhid")))
  41       return InputDeviceType::INPUT_DEVICE_EXTERNAL;
  42
  43     std::string subsystem_path =
  44         base::MakeAbsoluteFilePath(path.Append(FILE_PATH_LITERAL("subsystem")))
  45             .value();
  46     if (subsystem_path.empty())
  47       continue;
  48
  49     // Internal bus attachments.
  50     if (subsystem_path == "/sys/bus/pci")
  51       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  52     if (subsystem_path == "/sys/bus/i2c")
  53       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  54     if (subsystem_path == "/sys/bus/acpi")
  55       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  56     if (subsystem_path == "/sys/bus/serio")
  57       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  58     if (subsystem_path == "/sys/bus/platform")
  59       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  60
  61     // External bus attachments.
  62     if (subsystem_path == "/sys/bus/usb")
  63       return InputDeviceType::INPUT_DEVICE_EXTERNAL;
  64     if (subsystem_path == "/sys/class/bluetooth")
  65       return InputDeviceType::INPUT_DEVICE_EXTERNAL;
  66   }
  67
  68   return InputDeviceType::INPUT_DEVICE_UNKNOWN;
  69 }
  70
  71 }  // namespace