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() || !StartsWithASCII(event_node, "event", false))
  21     return InputDeviceType::INPUT_DEVICE_UNKNOWN;
  22
  23   // Find sysfs device path for this device.
  24   base::FilePath sysfs_path =
  25       base::FilePath(FILE_PATH_LITERAL("/sys/class/input"));
  26   sysfs_path = sysfs_path.Append(path.BaseName());
  27   sysfs_path = base::MakeAbsoluteFilePath(sysfs_path);
  28
  29   // Device does not exist.
  30   if (sysfs_path.empty())
  31     return InputDeviceType::INPUT_DEVICE_UNKNOWN;
  32
  33   // Check ancestor devices for a known bus attachment.
  34   for (base::FilePath path = sysfs_path; path != base::FilePath("/");
  35        path = path.DirName()) {
  36     std::string subsystem_path =
  37         base::MakeAbsoluteFilePath(path.Append(FILE_PATH_LITERAL("subsystem")))
  38             .value();
  39     if (subsystem_path.empty())
  40       continue;
  41
  42     // Internal bus attachments.
  43     if (subsystem_path == "/sys/bus/pci")
  44       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  45     if (subsystem_path == "/sys/bus/i2c")
  46       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  47     if (subsystem_path == "/sys/bus/acpi")
  48       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  49     if (subsystem_path == "/sys/bus/serio")
  50       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  51     if (subsystem_path == "/sys/bus/platform")
  52       return InputDeviceType::INPUT_DEVICE_INTERNAL;
  53
  54     // External bus attachments.
  55     if (subsystem_path == "/sys/bus/usb")
  56       return InputDeviceType::INPUT_DEVICE_EXTERNAL;
  57     if (subsystem_path == "/sys/class/bluetooth")
  58       return InputDeviceType::INPUT_DEVICE_EXTERNAL;
  59   }
  60
  61   return InputDeviceType::INPUT_DEVICE_UNKNOWN;
  62 }
  63
  64 }  // namespace