Read and expose accelerometer values from cros-ec-accel trigger.

BUG=342907

Review URL: https://codereview.chromium.org/200643005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@261317 0039d316-1c4b-4281-b951-d872f2087c98

11 files changed, 462 insertions, 0 deletions

diff --git a/ash/accelerometer/accelerometer_controller.cc b/ash/accelerometer/accelerometer_controller.cc
new file mode 100644
index 0000000..a8de559
--- /dev/null
+++ b/ash/accelerometer/accelerometer_controller.cc
@@ -0,0 +1,42 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ash/accelerometer/accelerometer_controller.h"
+
+#include "ash/accelerometer/accelerometer_observer.h"
+#include "ui/gfx/geometry/vector3d_f.h"
+
+namespace ash {
+
+AccelerometerController::AccelerometerController() {
+}
+
+AccelerometerController::~AccelerometerController() {
+}
+
+void AccelerometerController::Initialize(
+    scoped_refptr<base::TaskRunner> blocking_task_runner) {
+#if defined(OS_CHROMEOS)
+  reader_.reset(new chromeos::AccelerometerReader(blocking_task_runner, this));
+#endif
+}
+
+void AccelerometerController::AddObserver(AccelerometerObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void AccelerometerController::RemoveObserver(AccelerometerObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+#if defined(OS_CHROMEOS)
+void AccelerometerController::HandleAccelerometerReading(
+    const gfx::Vector3dF& base,
+    const gfx::Vector3dF& lid) {
+  FOR_EACH_OBSERVER(AccelerometerObserver, observers_,
+      OnAccelerometerUpdated(base, lid));
+}
+#endif
+
+}  // namespace ash
diff --git a/ash/accelerometer/accelerometer_controller.h b/ash/accelerometer/accelerometer_controller.h
new file mode 100644
index 0000000..ffe9c55
--- /dev/null
+++ b/ash/accelerometer/accelerometer_controller.h
@@ -0,0 +1,71 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_ACCELEROMETER_ACCELEROMETER_CONTROLLER_H_
+#define ASH_ACCELEROMETER_ACCELEROMETER_CONTROLLER_H_
+
+#include "ash/ash_export.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/observer_list.h"
+
+#if defined(OS_CHROMEOS)
+#include "chromeos/accelerometer/accelerometer_reader.h"
+#endif
+
+namespace base {
+class TaskRunner;
+}
+
+namespace gfx {
+class Vector3dF;
+}
+
+namespace ash {
+
+class AccelerometerObserver;
+
+// This class owns the communication interface for talking to the accelerometer
+// on supporting devices. Observers will be delivered OnAccelerometerRead
+// notifications if an accelerometer was detected.
+class ASH_EXPORT AccelerometerController
+#if defined(OS_CHROMEOS)
+    : public chromeos::AccelerometerReader::Delegate {
+#else
+    {
+#endif
+ public:
+  AccelerometerController();
+  virtual ~AccelerometerController();
+
+  // Initialize the accelerometer reader.
+  void Initialize(scoped_refptr<base::TaskRunner> blocking_task_runner);
+
+  // Add/remove observer.
+  void AddObserver(AccelerometerObserver* observer);
+  void RemoveObserver(AccelerometerObserver* observer);
+
+#if defined(OS_CHROMEOS)
+  // This needs to be CHROMEOS only as on other platforms it does not actually
+  // override a method.
+  // chromeos::AccelerometerReader::Delegate:
+  virtual void HandleAccelerometerReading(const gfx::Vector3dF& base,
+                                          const gfx::Vector3dF& lid) OVERRIDE;
+#endif
+
+ private:
+#if defined(OS_CHROMEOS)
+  // The AccelerometerReader which directly triggers and reads from the
+  // accelerometer device.
+  scoped_ptr<chromeos::AccelerometerReader> reader_;
+#endif
+
+  ObserverList<AccelerometerObserver, true> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(AccelerometerController);
+};
+
+}  // namespace ash
+
+#endif  // ASH_ACCELEROMETER_ACCELEROMETER_CONTROLLER_H_
diff --git a/ash/accelerometer/accelerometer_observer.h b/ash/accelerometer/accelerometer_observer.h
new file mode 100644
index 0000000..3d70a42
--- /dev/null
+++ b/ash/accelerometer/accelerometer_observer.h
@@ -0,0 +1,26 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef ASH_ACCELEROMETER_ACCELEROMETER_OBSERVER_H_
+#define ASH_ACCELEROMETER_ACCELEROMETER_OBSERVER_H_
+
+namespace gfx {
+class Vector3dF;
+}
+
+namespace ash {
+
+// The interface for classes which observe accelerometer updates.
+class AccelerometerObserver {
+ public:
+  virtual void OnAccelerometerUpdated(const gfx::Vector3dF& base,
+                                      const gfx::Vector3dF& lid) = 0;
+
+ protected:
+  virtual ~AccelerometerObserver() {}
+};
+
+}  // namespace ash
+
+#endif  // ASH_ACCELEROMETER_ACCELEROMETER_OBSERVER_H_
diff --git a/ash/ash.gyp b/ash/ash.gyp
index ebb6e60..5ec38e7 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -75,6 +75,9 @@
         'accelerators/nested_dispatcher_controller.h',
         'accelerators/spoken_feedback_toggler.cc',
         'accelerators/spoken_feedback_toggler.h',
+        'accelerometer/accelerometer_controller.cc',
+        'accelerometer/accelerometer_controller.h',
+        'accelerometer/accelerometer_observer.h',
         'accessibility_delegate.h',
         'audio/sounds.cc',
         'audio/sounds.h',
diff --git a/ash/shell.cc b/ash/shell.cc
index 003053e8..ad9b92c 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -11,6 +11,7 @@
 #include "ash/accelerators/accelerator_filter.h"
 #include "ash/accelerators/focus_manager_factory.h"
 #include "ash/accelerators/nested_dispatcher_controller.h"
+#include "ash/accelerometer/accelerometer_controller.h"
 #include "ash/ash_switches.h"
 #include "ash/autoclick/autoclick_controller.h"
 #include "ash/desktop_background/desktop_background_controller.h"
@@ -606,6 +607,7 @@ Shell::Shell(ShellDelegate* delegate)
       delegate_(delegate),
       window_positioner_(new WindowPositioner),
       activation_client_(NULL),
+      accelerometer_controller_(new AccelerometerController()),
 #if defined(OS_CHROMEOS)
       output_configurator_(new ui::OutputConfigurator()),
 #endif  // defined(OS_CHROMEOS)
diff --git a/ash/shell.h b/ash/shell.h
index 1f511db..b096e51 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -74,6 +74,7 @@ class WindowModalityController;
 namespace ash {
 
 class AcceleratorController;
+class AccelerometerController;
 class AccessibilityDelegate;
 class AshNativeCursorManager;
 class AutoclickController;
@@ -500,6 +501,10 @@ class ASH_EXPORT Shell
   // Starts the animation that occurs on first login.
   void DoInitialWorkspaceAnimation();
 
+  AccelerometerController* accelerometer_controller() {
+    return accelerometer_controller_.get();
+  }
+
 #if defined(OS_CHROMEOS)
   // TODO(oshima): Move these objects to DisplayController.
   ui::OutputConfigurator* output_configurator() {
@@ -697,6 +702,8 @@ class ASH_EXPORT Shell
   // The maximized window manager (if enabled).
   scoped_ptr<internal::MaximizeModeWindowManager> maximize_mode_window_manager_;
 
+  scoped_ptr<AccelerometerController> accelerometer_controller_;
+
 #if defined(OS_CHROMEOS)
   scoped_ptr<internal::PowerEventObserver> power_event_observer_;
   scoped_ptr<internal::UserActivityNotifier> user_activity_notifier_;
diff --git a/chrome/browser/ui/ash/ash_init.cc b/chrome/browser/ui/ash/ash_init.cc
index 2af2f8a..d92d554 100644
--- a/chrome/browser/ui/ash/ash_init.cc
+++ b/chrome/browser/ui/ash/ash_init.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/ui/ash/ash_init.h"
 
 #include "ash/accelerators/accelerator_controller.h"
+#include "ash/accelerometer/accelerometer_controller.h"
 #include "ash/ash_switches.h"
 #include "ash/high_contrast/high_contrast_controller.h"
 #include "ash/magnifier/magnification_controller.h"
@@ -16,6 +17,7 @@
 #include "chrome/browser/ui/ash/chrome_shell_delegate.h"
 #include "chrome/browser/ui/ash/screenshot_taker.h"
 #include "chrome/common/chrome_switches.h"
+#include "content/public/browser/browser_thread.h"
 #include "ui/aura/env.h"
 #include "ui/aura/window_tree_host.h"
 
@@ -58,6 +60,11 @@ void OpenAsh() {
   ash::Shell* shell = ash::Shell::CreateInstance(new ChromeShellDelegate);
   shell->accelerator_controller()->SetScreenshotDelegate(
       scoped_ptr<ash::ScreenshotDelegate>(new ScreenshotTaker).Pass());
+  // TODO(flackr): Investigate exposing a blocking pool task runner to chromeos.
+  shell->accelerometer_controller()->Initialize(
+      content::BrowserThread::GetBlockingPool()->
+          GetTaskRunnerWithShutdownBehavior(
+              base::SequencedWorkerPool::SKIP_ON_SHUTDOWN));
 #if defined(OS_CHROMEOS)
   shell->accelerator_controller()->SetImeControlDelegate(
       scoped_ptr<ash::ImeControlDelegate>(new ImeController).Pass());
diff --git a/chromeos/DEPS b/chromeos/DEPS
index a88fc06..82f85b3 100644
--- a/chromeos/DEPS
+++ b/chromeos/DEPS
@@ -3,4 +3,5 @@ include_rules = [
   "+net",
   "+third_party/cros_system_api",
   "+third_party/libxml",
+  "+ui/gfx/geometry"
 ]
diff --git a/chromeos/accelerometer/accelerometer_reader.cc b/chromeos/accelerometer/accelerometer_reader.cc
new file mode 100644
index 0000000..f84c487
--- /dev/null
+++ b/chromeos/accelerometer/accelerometer_reader.cc
@@ -0,0 +1,218 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chromeos/accelerometer/accelerometer_reader.h"
+
+#include "base/bind.h"
+#include "base/file_util.h"
+#include "base/location.h"
+#include "base/message_loop/message_loop.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
+#include "base/task_runner.h"
+#include "base/task_runner_util.h"
+#include "base/threading/sequenced_worker_pool.h"
+
+namespace chromeos {
+
+namespace {
+
+// Paths to access necessary data from the accelerometer device.
+const base::FilePath::CharType kAccelerometerTriggerPath[] =
+    FILE_PATH_LITERAL("/sys/bus/iio/devices/trigger0/trigger_now");
+const base::FilePath::CharType kAccelerometerDevicePath[] =
+    FILE_PATH_LITERAL("/dev/cros-ec-accel");
+const base::FilePath::CharType kAccelerometerIioBasePath[] =
+    FILE_PATH_LITERAL("/sys/bus/iio/devices/");
+
+// Files within the device in kAccelerometerIioBasePath containing the scales of
+// the accelerometers.
+const base::FilePath::CharType kAccelerometerBaseScaleName[] =
+    FILE_PATH_LITERAL("in_accel_base_scale");
+const base::FilePath::CharType kAccelerometerLidScaleName[] =
+    FILE_PATH_LITERAL("in_accel_lid_scale");
+
+// The filename giving the path to read the scan index of each accelerometer
+// axis.
+const char kAccelerometerScanIndexPath[] =
+    "scan_elements/in_accel_%s_%s_index";
+
+// The names of the accelerometers and axes in the order we want to read them.
+const char kAccelerometerNames[][5] = {"base", "lid"};
+const char kAccelerometerAxes[][2] = {"x", "y", "z"};
+const size_t kTriggerDataValues =
+    arraysize(kAccelerometerNames) * arraysize(kAccelerometerAxes);
+const size_t kTriggerDataLength = kTriggerDataValues * 2;
+
+// The length required to read uint values from configuration files.
+const size_t kMaxAsciiUintLength = 21;
+
+// The time to wait between reading the accelerometer.
+const int kDelayBetweenReadsMs = 100;
+
+// Reads |path| to the unsigned int pointed to by |value|. Returns true on
+// success or false on failure.
+bool ReadFileToUint(const base::FilePath& path, unsigned int* value) {
+  std::string s;
+  DCHECK(value);
+  if (!base::ReadFileToString(path, &s, kMaxAsciiUintLength)) {
+    LOG(ERROR) << "Failed to read " << path.value();
+    return false;
+  }
+  base::TrimWhitespaceASCII(s, base::TRIM_ALL, &s);
+  if (!base::StringToUint(s, value)) {
+    LOG(ERROR) << "Failed to parse \"" << s << "\" from " << path.value();
+    return false;
+  }
+  return true;
+}
+
+bool DetectAndReadAccelerometerConfiguration(
+    scoped_refptr<AccelerometerReader::Configuration> configuration) {
+  // Check for accelerometer symlink which will be created by the udev rules
+  // file on detecting the device.
+  base::FilePath device;
+  if (!base::ReadSymbolicLink(base::FilePath(kAccelerometerDevicePath),
+                              &device)) {
+    return false;
+  }
+
+  if (!base::PathExists(base::FilePath(kAccelerometerTriggerPath))) {
+    LOG(ERROR) << "Accelerometer trigger does not exist at"
+               << kAccelerometerTriggerPath;
+    return false;
+  }
+
+  base::FilePath iio_path(base::FilePath(kAccelerometerIioBasePath).Append(
+      device));
+  // Read accelerometer scales
+  if (!ReadFileToUint(iio_path.Append(kAccelerometerBaseScaleName),
+                      &(configuration->data.base_scale))) {
+    return false;
+  }
+  if (!ReadFileToUint(iio_path.Append(kAccelerometerLidScaleName),
+                      &(configuration->data.lid_scale))) {
+    return false;
+  }
+
+  // Read indices of each accelerometer axis from each accelerometer from
+  // /sys/bus/iio/devices/iio:deviceX/scan_elements/in_accel_{x,y,z}_%s_index
+  for (size_t i = 0; i < arraysize(kAccelerometerNames); ++i) {
+    for (size_t j = 0; j < arraysize(kAccelerometerAxes); ++j) {
+      std::string accelerometer_index_path = base::StringPrintf(
+          kAccelerometerScanIndexPath, kAccelerometerAxes[j],
+          kAccelerometerNames[i]);
+      unsigned int index = 0;
+      if (!ReadFileToUint(iio_path.Append(accelerometer_index_path.c_str()),
+                          &index)) {
+        return false;
+      }
+      if (index >= kTriggerDataValues) {
+        LOG(ERROR) << "Field index from " << accelerometer_index_path
+                   << " out of bounds: " << index;
+        return false;
+      }
+      configuration->data.index.push_back(index);
+    }
+  }
+  return true;
+}
+
+bool ReadAccelerometer(
+    scoped_refptr<AccelerometerReader::Reading> reading) {
+  // Initiate the trigger to read accelerometers simultaneously
+  int bytes_written = base::WriteFile(
+      base::FilePath(kAccelerometerTriggerPath), "1\n", 2);
+  if (bytes_written < 2) {
+    PLOG(ERROR) << "Accelerometer trigger failure: " << bytes_written;
+    return false;
+  }
+
+  // Read resulting sample from /dev/cros-ec-accel.
+  int bytes_read = base::ReadFile(base::FilePath(kAccelerometerDevicePath),
+                                  reading->data, kTriggerDataLength);
+  if (bytes_read < static_cast<int>(kTriggerDataLength)) {
+    LOG(ERROR) << "Read " << bytes_read << " byte(s), expected "
+               << kTriggerDataLength << " bytes from accelerometer";
+    return false;
+  }
+  return true;
+}
+
+}  // namespace
+
+AccelerometerReader::ConfigurationData::ConfigurationData() {
+}
+
+AccelerometerReader::ConfigurationData::~ConfigurationData() {
+}
+
+AccelerometerReader::AccelerometerReader(
+    base::TaskRunner* task_runner,
+    AccelerometerReader::Delegate* delegate)
+    : task_runner_(task_runner),
+      delegate_(delegate),
+      configuration_(new AccelerometerReader::Configuration()),
+      weak_factory_(this) {
+  DCHECK(task_runner_);
+  DCHECK(delegate_);
+  // Asynchronously detect and initialize the accelerometer to avoid delaying
+  // startup.
+  base::PostTaskAndReplyWithResult(task_runner_.get(), FROM_HERE,
+      base::Bind(&DetectAndReadAccelerometerConfiguration, configuration_),
+      base::Bind(&AccelerometerReader::OnInitialized,
+                 weak_factory_.GetWeakPtr(), configuration_));
+}
+
+AccelerometerReader::~AccelerometerReader() {
+}
+
+void AccelerometerReader::OnInitialized(
+    scoped_refptr<AccelerometerReader::Configuration> configuration,
+    bool success) {
+  if (success)
+    TriggerRead();
+}
+
+void AccelerometerReader::TriggerRead() {
+  DCHECK(!task_runner_->RunsTasksOnCurrentThread());
+
+  scoped_refptr<AccelerometerReader::Reading> reading(
+      new AccelerometerReader::Reading());
+  base::PostTaskAndReplyWithResult(task_runner_, FROM_HERE,
+      base::Bind(&ReadAccelerometer, reading),
+      base::Bind(&AccelerometerReader::OnDataRead,
+          weak_factory_.GetWeakPtr(), reading));
+}
+
+void AccelerometerReader::OnDataRead(
+    scoped_refptr<AccelerometerReader::Reading> reading,
+    bool success) {
+  DCHECK(!task_runner_->RunsTasksOnCurrentThread());
+
+  if (success) {
+    gfx::Vector3dF base_reading, lid_reading;
+    int16* values = reinterpret_cast<int16*>(reading->data);
+    base_reading.set_x(values[configuration_->data.index[0]]);
+    base_reading.set_y(values[configuration_->data.index[1]]);
+    base_reading.set_z(values[configuration_->data.index[2]]);
+    base_reading.Scale(1.0f / configuration_->data.base_scale);
+
+    lid_reading.set_x(values[configuration_->data.index[3]]);
+    lid_reading.set_y(values[configuration_->data.index[4]]);
+    lid_reading.set_z(values[configuration_->data.index[5]]);
+    lid_reading.Scale(1.0f / configuration_->data.lid_scale);
+    delegate_->HandleAccelerometerReading(base_reading, lid_reading);
+  }
+
+  // Trigger another read after the current sampling delay.
+  base::MessageLoop::current()->PostDelayedTask(
+      FROM_HERE,
+      base::Bind(&AccelerometerReader::TriggerRead,
+                 weak_factory_.GetWeakPtr()),
+      base::TimeDelta::FromMilliseconds(kDelayBetweenReadsMs));
+}
+
+}  // namespace chromeos
diff --git a/chromeos/accelerometer/accelerometer_reader.h b/chromeos/accelerometer/accelerometer_reader.h
new file mode 100644
index 0000000..e2b85bc
--- /dev/null
+++ b/chromeos/accelerometer/accelerometer_reader.h
@@ -0,0 +1,82 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_
+#define CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_
+
+#include <vector>
+
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/observer_list.h"
+#include "chromeos/chromeos_export.h"
+#include "ui/gfx/geometry/vector3d_f.h"
+
+namespace base {
+class TaskRunner;
+}
+
+namespace chromeos {
+
+// Reads an accelerometer device and reports data back to an
+// AccelerometerDelegate.
+class CHROMEOS_EXPORT AccelerometerReader {
+ public:
+  // Configuration structure for accelerometer device.
+  struct ConfigurationData {
+    ConfigurationData();
+    ~ConfigurationData();
+
+    // Scale of accelerometers (i.e. raw value * 1.0f / scale = G's).
+    unsigned int base_scale;
+    unsigned int lid_scale;
+
+    // Index of each accelerometer axis in data stream.
+    std::vector<unsigned int> index;
+  };
+  typedef base::RefCountedData<ConfigurationData> Configuration;
+  typedef base::RefCountedData<char[12]> Reading;
+
+  // An interface to receive data from the AccelerometerReader.
+  class Delegate {
+   public:
+    virtual void HandleAccelerometerReading(const gfx::Vector3dF& base,
+                                            const gfx::Vector3dF& lid) = 0;
+  };
+
+  AccelerometerReader(base::TaskRunner* blocking_task_runner,
+                      Delegate* delegate);
+  ~AccelerometerReader();
+
+ private:
+  // Dispatched when initialization is complete. If |success|, |configuration|
+  // provides the details of the detected accelerometer.
+  void OnInitialized(scoped_refptr<Configuration> configuration, bool success);
+
+  // Triggers an asynchronous read from the accelerometer, signalling
+  // OnDataRead with the result.
+  void TriggerRead();
+
+  // If |success|, converts the raw reading to a pair of Vector3dF
+  // values and notifies the |delegate_| with the new readings.
+  // Triggers another read from the accelerometer at the current sampling rate.
+  void OnDataRead(scoped_refptr<Reading> reading, bool success);
+
+  // The task runner to use for blocking tasks.
+  scoped_refptr<base::TaskRunner> task_runner_;
+
+  // A weak pointer to the delegate to send accelerometer readings to.
+  Delegate* delegate_;
+
+  // The accelerometer configuration.
+  scoped_refptr<Configuration> configuration_;
+
+  base::WeakPtrFactory<AccelerometerReader> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(AccelerometerReader);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_ACCELEROMETER_ACCELEROMETER_READER_H_
diff --git a/chromeos/chromeos.gyp b/chromeos/chromeos.gyp
index e9fffa9..89c64fe 100644
--- a/chromeos/chromeos.gyp
+++ b/chromeos/chromeos.gyp
@@ -25,6 +25,7 @@
         '../net/net.gyp:net',
         '../third_party/icu/icu.gyp:icui18n',
         '../third_party/libxml/libxml.gyp:libxml',
+        '../ui/gfx/gfx.gyp:gfx_geometry',
         '../url/url.gyp:url_lib',
         'cryptohome_proto',
         'ime/input_method.gyp:gencode',
@@ -34,6 +35,8 @@
         'CHROMEOS_IMPLEMENTATION',
       ],
       'sources': [
+        'accelerometer/accelerometer_reader.cc',
+        'accelerometer/accelerometer_reader.h',
         'app_mode/kiosk_oem_manifest_parser.cc',
         'app_mode/kiosk_oem_manifest_parser.h',
         'audio/audio_device.cc',