| // 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 <stddef.h> |
| #include <stdint.h> |
| |
| #include <string> |
| #include <vector> |
| |
| #include "base/bind.h" |
| #include "base/files/file_enumerator.h" |
| #include "base/files/file_util.h" |
| #include "base/location.h" |
| #include "base/macros.h" |
| #include "base/memory/singleton.h" |
| #include "base/single_thread_task_runner.h" |
| #include "base/strings/string_number_conversions.h" |
| #include "base/strings/string_util.h" |
| #include "base/strings/stringprintf.h" |
| #include "base/sys_info.h" |
| #include "base/task_runner.h" |
| #include "base/task_runner_util.h" |
| #include "base/thread_task_runner_handle.h" |
| #include "base/threading/platform_thread.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/"); |
| |
| // This is the per source scale file in use on kernels older than 3.18. We |
| // should remove this when all devices having accelerometers are on kernel 3.18 |
| // or later or have been patched to use new format: http://crbug.com/510831 |
| const base::FilePath::CharType kLegacyScaleNameFormatString[] = |
| "in_accel_%s_scale"; |
| |
| // File within kAccelerometerDevicePath/device* which denotes a single scale to |
| // be used across all axes. |
| const base::FilePath::CharType kAccelerometerScaleFileName[] = "scale"; |
| |
| // File within kAccelerometerDevicePath/device* which denotes the |
| // AccelerometerSource for the accelerometer. |
| const base::FilePath::CharType kAccelerometerLocationFileName[] = "location"; |
| |
| // The filename giving the path to read the scan index of each accelerometer |
| // axis. |
| const char kLegacyAccelerometerScanIndexPathFormatString[] = |
| "scan_elements/in_accel_%s_%s_index"; |
| |
| // The filename giving the path to read the scan index of each accelerometer |
| // when they are separate device paths. |
| const char kAccelerometerScanIndexPathFormatString[] = |
| "scan_elements/in_accel_%s_index"; |
| |
| // The names of the accelerometers. Matches up with the enum AccelerometerSource |
| // in chromeos/accelerometer/accelerometer_types.h. |
| const char kAccelerometerNames[ACCELEROMETER_SOURCE_COUNT][5] = {"lid", "base"}; |
| |
| // The axes on each accelerometer. The order was changed on kernel 3.18+. |
| const char kAccelerometerAxes[][2] = {"x", "y", "z"}; |
| const char kLegacyAccelerometerAxes[][2] = {"y", "x", "z"}; |
| |
| // The length required to read uint values from configuration files. |
| const size_t kMaxAsciiUintLength = 21; |
| |
| // The size of individual values. |
| const size_t kDataSize = 2; |
| |
| // The mean acceleration due to gravity on Earth in m/s^2. |
| const float kMeanGravity = 9.80665f; |
| |
| // The number of axes for which there are acceleration readings. |
| const int kNumberOfAxes = 3; |
| |
| // The size of data in one reading of the accelerometers. |
| const int kSizeOfReading = kDataSize * kNumberOfAxes; |
| |
| // Reads |path| to the unsigned int pointed to by |value|. Returns true on |
| // success or false on failure. |
| bool ReadFileToInt(const base::FilePath& path, int* value) { |
| std::string s; |
| DCHECK(value); |
| if (!base::ReadFileToString(path, &s, kMaxAsciiUintLength)) { |
| return false; |
| } |
| base::TrimWhitespaceASCII(s, base::TRIM_ALL, &s); |
| if (!base::StringToInt(s, value)) { |
| LOG(ERROR) << "Failed to parse int \"" << s << "\" from " << path.value(); |
| return false; |
| } |
| return true; |
| } |
| |
| // Reads |path| to the double pointed to by |value|. Returns true on success or |
| // false on failure. |
| bool ReadFileToDouble(const base::FilePath& path, double* value) { |
| std::string s; |
| DCHECK(value); |
| if (!base::ReadFileToString(path, &s)) { |
| return false; |
| } |
| base::TrimWhitespaceASCII(s, base::TRIM_ALL, &s); |
| if (!base::StringToDouble(s, value)) { |
| LOG(ERROR) << "Failed to parse double \"" << s << "\" from " |
| << path.value(); |
| return false; |
| } |
| return true; |
| } |
| |
| } // namespace |
| |
| const int AccelerometerReader::kDelayBetweenReadsMs = 100; |
| |
| // Work that runs on a base::TaskRunner. It determines the accelerometer |
| // configuartion, and reads the data. Upon a successful read it will notify |
| // all observers. |
| class AccelerometerFileReader |
| : public base::RefCountedThreadSafe<AccelerometerFileReader> { |
| public: |
| AccelerometerFileReader(); |
| |
| // Detects the accelerometer configuration, if an accelerometer is available |
| // triggers reads. |
| void Initialize( |
| scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner); |
| |
| // Attempts to read the accelerometer data. Upon a success, converts the raw |
| // reading to an AccelerometerUpdate and notifies observers. Triggers another |
| // read at the current sampling rate. |
| void Read(); |
| |
| // Add/Remove observers. |
| void AddObserver(AccelerometerReader::Observer* observer); |
| void RemoveObserver(AccelerometerReader::Observer* observer); |
| |
| private: |
| friend class base::RefCountedThreadSafe<AccelerometerFileReader>; |
| |
| // Represents necessary information in order to read an accelerometer device. |
| struct ReadingData { |
| // The full path to the accelerometer device to read. |
| base::FilePath path; |
| |
| // The accelerometer sources which can be read from |path|. |
| std::vector<AccelerometerSource> sources; |
| }; |
| |
| // Configuration structure for accelerometer device. |
| struct ConfigurationData { |
| ConfigurationData(); |
| ~ConfigurationData(); |
| |
| // Number of accelerometers on device. |
| size_t count; |
| |
| // Which accelerometers are present on device. |
| bool has[ACCELEROMETER_SOURCE_COUNT]; |
| |
| // Scale of accelerometers (i.e. raw value * scale = m/s^2). |
| float scale[ACCELEROMETER_SOURCE_COUNT][3]; |
| |
| // Index of each accelerometer axis in data stream. |
| int index[ACCELEROMETER_SOURCE_COUNT][3]; |
| |
| // The information for each accelerometer device to be read. In kernel 3.18 |
| // there is one per ACCELEROMETER_SOURCE_COUNT, on 3.14 there is only one. |
| std::vector<ReadingData> reading_data; |
| }; |
| |
| ~AccelerometerFileReader() {} |
| |
| // When accelerometers are presented as separate iio_devices this will perform |
| // the initialize for one of the devices, at the given |iio_path| and the |
| // symbolic link |name|. |location| is defined by AccelerometerSoure. |
| bool InitializeAccelerometer(const base::FilePath& iio_path, |
| const base::FilePath& name, |
| const std::string& location); |
| |
| // TODO(jonross): Separate the initialization into separate files. Add a gyp |
| // rule to have them built for the appropriate kernels. (crbug.com/525658) |
| // When accelerometers are presented as a single iio_device this will perform |
| // the initialization for both of them. |
| bool InitializeLegacyAccelerometers(const base::FilePath& iio_path, |
| const base::FilePath& name); |
| |
| // Attempts to read the accelerometer data. Upon a success, converts the raw |
| // reading to an AccelerometerUpdate and notifies observers. |
| void ReadFileAndNotify(); |
| |
| // True if Initialize completed successfully, and there is an accelerometer |
| // file to read. |
| bool initialization_successful_; |
| |
| // The accelerometer configuration. |
| ConfigurationData configuration_; |
| |
| // The observers to notify of accelerometer updates. |
| scoped_refptr<base::ObserverListThreadSafe<AccelerometerReader::Observer>> |
| observers_; |
| |
| // The task runner to use for blocking tasks. |
| scoped_refptr<base::SequencedTaskRunner> task_runner_; |
| |
| // The last seen accelerometer data. |
| scoped_refptr<AccelerometerUpdate> update_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AccelerometerFileReader); |
| }; |
| |
| AccelerometerFileReader::AccelerometerFileReader() |
| : initialization_successful_(false), |
| observers_( |
| new base::ObserverListThreadSafe<AccelerometerReader::Observer>()) { |
| } |
| |
| void AccelerometerFileReader::Initialize( |
| scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner) { |
| DCHECK( |
| base::SequencedWorkerPool::GetSequenceTokenForCurrentThread().IsValid()); |
| task_runner_ = sequenced_task_runner; |
| |
| // Check for accelerometer symlink which will be created by the udev rules |
| // file on detecting the device. |
| if (base::IsDirectoryEmpty(base::FilePath(kAccelerometerDevicePath))) { |
| if (base::SysInfo::IsRunningOnChromeOS()) { |
| LOG(ERROR) << "Accelerometer device directory is empty at " |
| << kAccelerometerDevicePath; |
| } |
| return; |
| } |
| if (!base::PathExists(base::FilePath(kAccelerometerTriggerPath))) { |
| if (base::SysInfo::IsRunningOnChromeOS()) { |
| LOG(ERROR) << "Accelerometer trigger does not exist at" |
| << kAccelerometerTriggerPath; |
| } |
| return; |
| } |
| |
| base::FileEnumerator symlink_dir(base::FilePath(kAccelerometerDevicePath), |
| false, base::FileEnumerator::FILES); |
| bool legacy_cross_accel = false; |
| for (base::FilePath name = symlink_dir.Next(); !name.empty(); |
| name = symlink_dir.Next()) { |
| base::FilePath iio_device; |
| if (!base::ReadSymbolicLink(name, &iio_device)) { |
| LOG(ERROR) << "Failed to read symbolic link " << kAccelerometerDevicePath |
| << "/" << name.MaybeAsASCII() << "\n"; |
| return; |
| } |
| |
| base::FilePath iio_path(base::FilePath(kAccelerometerIioBasePath) |
| .Append(iio_device.BaseName())); |
| std::string location; |
| legacy_cross_accel = !base::ReadFileToString( |
| base::FilePath(iio_path).Append(kAccelerometerLocationFileName), |
| &location); |
| if (legacy_cross_accel) { |
| if (!InitializeLegacyAccelerometers(iio_path, name)) |
| return; |
| } else { |
| base::TrimWhitespaceASCII(location, base::TRIM_ALL, &location); |
| if (!InitializeAccelerometer(iio_path, name, location)) |
| return; |
| } |
| } |
| |
| // Verify indices are within bounds. |
| for (int i = 0; i < ACCELEROMETER_SOURCE_COUNT; ++i) { |
| if (!configuration_.has[i]) |
| continue; |
| for (int j = 0; j < 3; ++j) { |
| if (configuration_.index[i][j] < 0 || |
| configuration_.index[i][j] >= |
| 3 * static_cast<int>(configuration_.count)) { |
| const char* axis = legacy_cross_accel ? kLegacyAccelerometerAxes[j] |
| : kAccelerometerAxes[j]; |
| LOG(ERROR) << "Field index for " << kAccelerometerNames[i] << " " |
| << axis << " axis out of bounds."; |
| return; |
| } |
| } |
| } |
| |
| initialization_successful_ = true; |
| Read(); |
| } |
| |
| void AccelerometerFileReader::Read() { |
| DCHECK( |
| base::SequencedWorkerPool::GetSequenceTokenForCurrentThread().IsValid()); |
| ReadFileAndNotify(); |
| task_runner_->PostNonNestableDelayedTask( |
| FROM_HERE, base::Bind(&AccelerometerFileReader::Read, this), |
| base::TimeDelta::FromMilliseconds( |
| AccelerometerReader::kDelayBetweenReadsMs)); |
| } |
| |
| void AccelerometerFileReader::AddObserver( |
| AccelerometerReader::Observer* observer) { |
| observers_->AddObserver(observer); |
| if (initialization_successful_) { |
| task_runner_->PostNonNestableTask( |
| FROM_HERE, |
| base::Bind(&AccelerometerFileReader::ReadFileAndNotify, this)); |
| } |
| } |
| |
| void AccelerometerFileReader::RemoveObserver( |
| AccelerometerReader::Observer* observer) { |
| observers_->RemoveObserver(observer); |
| } |
| |
| bool AccelerometerFileReader::InitializeAccelerometer( |
| const base::FilePath& iio_path, |
| const base::FilePath& name, |
| const std::string& location) { |
| size_t config_index = 0; |
| for (; config_index < arraysize(kAccelerometerNames); ++config_index) { |
| if (location == kAccelerometerNames[config_index]) |
| break; |
| } |
| |
| if (config_index >= arraysize(kAccelerometerNames)) { |
| LOG(ERROR) << "Unrecognized location: " << location << " for device " |
| << name.MaybeAsASCII() << "\n"; |
| return false; |
| } |
| |
| double scale; |
| if (!ReadFileToDouble(iio_path.Append(kAccelerometerScaleFileName), &scale)) |
| return false; |
| |
| const int kNumberAxes = arraysize(kAccelerometerAxes); |
| for (size_t i = 0; i < kNumberAxes; ++i) { |
| std::string accelerometer_index_path = base::StringPrintf( |
| kAccelerometerScanIndexPathFormatString, kAccelerometerAxes[i]); |
| if (!ReadFileToInt(iio_path.Append(accelerometer_index_path.c_str()), |
| &(configuration_.index[config_index][i]))) { |
| LOG(ERROR) << "Index file " << accelerometer_index_path |
| << " could not be parsed\n"; |
| return false; |
| } |
| configuration_.scale[config_index][i] = scale; |
| } |
| configuration_.has[config_index] = true; |
| configuration_.count++; |
| |
| ReadingData reading_data; |
| reading_data.path = |
| base::FilePath(kAccelerometerDevicePath).Append(name.BaseName()); |
| reading_data.sources.push_back( |
| static_cast<AccelerometerSource>(config_index)); |
| |
| configuration_.reading_data.push_back(reading_data); |
| |
| return true; |
| } |
| |
| bool AccelerometerFileReader::InitializeLegacyAccelerometers( |
| const base::FilePath& iio_path, |
| const base::FilePath& name) { |
| ReadingData reading_data; |
| reading_data.path = |
| base::FilePath(kAccelerometerDevicePath).Append(name.BaseName()); |
| // Read configuration of each accelerometer axis from each accelerometer from |
| // /sys/bus/iio/devices/iio:deviceX/. |
| for (size_t i = 0; i < arraysize(kAccelerometerNames); ++i) { |
| configuration_.has[i] = false; |
| // Read scale of accelerometer. |
| std::string accelerometer_scale_path = base::StringPrintf( |
| kLegacyScaleNameFormatString, kAccelerometerNames[i]); |
| // Read the scale for all axes. |
| int scale_divisor = 0; |
| if (!ReadFileToInt(iio_path.Append(accelerometer_scale_path.c_str()), |
| &scale_divisor)) { |
| continue; |
| } |
| if (scale_divisor == 0) { |
| LOG(ERROR) << "Accelerometer " << accelerometer_scale_path |
| << "has scale of 0 and will not be used."; |
| continue; |
| } |
| |
| configuration_.has[i] = true; |
| for (size_t j = 0; j < arraysize(kLegacyAccelerometerAxes); ++j) { |
| configuration_.scale[i][j] = kMeanGravity / scale_divisor; |
| std::string accelerometer_index_path = base::StringPrintf( |
| kLegacyAccelerometerScanIndexPathFormatString, |
| kLegacyAccelerometerAxes[j], kAccelerometerNames[i]); |
| if (!ReadFileToInt(iio_path.Append(accelerometer_index_path.c_str()), |
| &(configuration_.index[i][j]))) { |
| configuration_.has[i] = false; |
| LOG(ERROR) << "Index file " << accelerometer_index_path |
| << " could not be parsed\n"; |
| return false; |
| } |
| } |
| if (configuration_.has[i]) { |
| configuration_.count++; |
| reading_data.sources.push_back(static_cast<AccelerometerSource>(i)); |
| } |
| } |
| |
| // Adjust the directions of accelerometers to match the AccelerometerUpdate |
| // type specified in chromeos/accelerometer/accelerometer_types.h. |
| configuration_.scale[ACCELEROMETER_SOURCE_SCREEN][1] *= -1.0f; |
| configuration_.scale[ACCELEROMETER_SOURCE_SCREEN][2] *= -1.0f; |
| |
| configuration_.reading_data.push_back(reading_data); |
| return true; |
| } |
| |
| void AccelerometerFileReader::ReadFileAndNotify() { |
| DCHECK(initialization_successful_); |
| |
| // 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; |
| } |
| |
| // Read resulting sample from /dev/cros-ec-accel. |
| update_ = new AccelerometerUpdate(); |
| for (auto reading_data : configuration_.reading_data) { |
| int reading_size = reading_data.sources.size() * kSizeOfReading; |
| DCHECK_GT(reading_size, 0); |
| char reading[reading_size]; |
| int bytes_read = base::ReadFile(reading_data.path, reading, reading_size); |
| if (bytes_read < reading_size) { |
| LOG(ERROR) << "Accelerometer Read " << bytes_read << " byte(s), expected " |
| << reading_size << " bytes from accelerometer " |
| << reading_data.path.MaybeAsASCII(); |
| return; |
| } |
| for (AccelerometerSource source : reading_data.sources) { |
| DCHECK(configuration_.has[source]); |
| int16_t* values = reinterpret_cast<int16_t*>(reading); |
| update_->Set(source, values[configuration_.index[source][0]] * |
| configuration_.scale[source][0], |
| values[configuration_.index[source][1]] * |
| configuration_.scale[source][1], |
| values[configuration_.index[source][2]] * |
| configuration_.scale[source][2]); |
| } |
| } |
| |
| observers_->Notify(FROM_HERE, |
| &AccelerometerReader::Observer::OnAccelerometerUpdated, |
| update_); |
| } |
| |
| AccelerometerFileReader::ConfigurationData::ConfigurationData() : count(0) { |
| for (int i = 0; i < ACCELEROMETER_SOURCE_COUNT; ++i) { |
| has[i] = false; |
| for (int j = 0; j < 3; ++j) { |
| scale[i][j] = 0; |
| index[i][j] = -1; |
| } |
| } |
| } |
| |
| AccelerometerFileReader::ConfigurationData::~ConfigurationData() { |
| } |
| |
| // static |
| AccelerometerReader* AccelerometerReader::GetInstance() { |
| return base::Singleton<AccelerometerReader>::get(); |
| } |
| |
| void AccelerometerReader::Initialize( |
| scoped_refptr<base::SequencedTaskRunner> sequenced_task_runner) { |
| DCHECK(sequenced_task_runner.get()); |
| // Asynchronously detect and initialize the accelerometer to avoid delaying |
| // startup. |
| sequenced_task_runner->PostNonNestableTask( |
| FROM_HERE, |
| base::Bind(&AccelerometerFileReader::Initialize, |
| accelerometer_file_reader_.get(), sequenced_task_runner)); |
| } |
| |
| void AccelerometerReader::AddObserver(Observer* observer) { |
| accelerometer_file_reader_->AddObserver(observer); |
| } |
| |
| void AccelerometerReader::RemoveObserver(Observer* observer) { |
| accelerometer_file_reader_->RemoveObserver(observer); |
| } |
| |
| AccelerometerReader::AccelerometerReader() |
| : accelerometer_file_reader_(new AccelerometerFileReader()) { |
| } |
| |
| AccelerometerReader::~AccelerometerReader() { |
| } |
| |
| } // namespace chromeos |