[Android][Telemetry] Remove android_ds2784 power monitor

BUG=

Review URL: https://codereview.chromium.org/1243233002

Cr-Commit-Position: refs/heads/master@{#339810}

tools/telemetry/telemetry/internal/platform/android_platform_backend.py

@@ -20,7 +20,6 @@ from telemetry.internal.forwarders import android_forwarder
 from telemetry.internal.image_processing import video
 from telemetry.internal.platform import android_device
 from telemetry.internal.platform import linux_based_platform_backend
-from telemetry.internal.platform.power_monitor import android_ds2784_power_monitor
 from telemetry.internal.platform.power_monitor import android_dumpsys_power_monitor
 from telemetry.internal.platform.power_monitor import android_temperature_monitor
 from telemetry.internal.platform.power_monitor import monsoon_power_monitor
@@ -165,7 +164,6 @@ class AndroidPlatformBackend(
     self._device_copy_script = None
     power_controller = power_monitor_controller.PowerMonitorController([
         monsoon_power_monitor.MonsoonPowerMonitor(self._device, self),
-        android_ds2784_power_monitor.DS2784PowerMonitor(self._device, self),
         android_dumpsys_power_monitor.DumpsysPowerMonitor(self._battery, self),
     ])
     self._power_monitor = android_temperature_monitor.AndroidTemperatureMonitor(

tools/telemetry/telemetry/internal/platform/power_monitor/android_ds2784_power_monitor.py

-# 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.
-
-import logging
-import os
-
-# pylint: disable=C0301
-from telemetry.core import util
-from telemetry import decorators
-from telemetry.internal.platform.power_monitor import sysfs_power_monitor
-from telemetry.internal.platform.profiler import android_prebuilt_profiler_helper
-# pylint: enable=C0301
-
-util.AddDirToPythonPath(util.GetChromiumSrcDir(), 'build', 'android')
-from pylib.device import battery_utils  # pylint: disable=F0401
-
-
-SAMPLE_RATE_HZ = 2 # The data is collected from the ds2784 fuel gauge chip
-                   # that only updates its data every 3.5s.
-FUEL_GAUGE_PATH = '/sys/class/power_supply/ds2784-fuelgauge'
-CHARGE_COUNTER = os.path.join(FUEL_GAUGE_PATH, 'charge_counter_ext')
-CURRENT = os.path.join(FUEL_GAUGE_PATH, 'current_now')
-VOLTAGE = os.path.join(FUEL_GAUGE_PATH, 'voltage_now')
-
-
-class DS2784PowerMonitor(sysfs_power_monitor.SysfsPowerMonitor):
-  """PowerMonitor that relies on the ds2784 fuel gauge chip.
-
-  The ds2784 chip is in some Android devices, for example the nexus 10.
-  This gives reliable energy numbers on Android L and higher releases.
-  """
-  def __init__(self, device, platform_backend):
-    super(DS2784PowerMonitor, self).__init__(platform_backend)
-    self._device = device
-    self._device_battery = battery_utils.BatteryUtils(self._device)
-    self._powermonitor_process_port = None
-    self._file_poller_binary = android_prebuilt_profiler_helper.GetDevicePath(
-        'file_poller')
-
-  @decorators.Cache
-  def _HasFuelGauge(self):
-    return self._device.FileExists(CHARGE_COUNTER)
-
-  def CanMonitorPower(self):
-    if not self._HasFuelGauge():
-      return False
-    try:
-      if self._device_battery.GetCharging():
-        logging.warning("Can't monitor power usage since device is charging.")
-        return False
-    except:
-      logging.exception('New exception caused by DeviceUtils conversion')
-      raise
-    return True
-
-  def StartMonitoringPower(self, browser):
-    assert not self._powermonitor_process_port, (
-        'Must call StopMonitoringPower().')
-    super(DS2784PowerMonitor, self).StartMonitoringPower(browser)
-    android_prebuilt_profiler_helper.InstallOnDevice(
-        self._device, 'file_poller')
-    self._powermonitor_process_port = int(
-        self._device.RunShellCommand(
-            '%s %d %s %s %s' % (self._file_poller_binary, SAMPLE_RATE_HZ,
-                                CHARGE_COUNTER, CURRENT, VOLTAGE))[0])
-
-  def StopMonitoringPower(self):
-    assert self._powermonitor_process_port, (
-        'StartMonitoringPower() not called.')
-    try:
-      cpu_stats = super(DS2784PowerMonitor, self).StopMonitoringPower()
-      result = '\n'.join(self._device.RunShellCommand(
-          '%s %d' % (self._file_poller_binary,
-                     self._powermonitor_process_port)))
-      assert result, 'PowerMonitor produced no output'
-      return super(DS2784PowerMonitor, self).CombineResults(
-          cpu_stats, DS2784PowerMonitor.ParseSamplingOutput(result))
-    finally:
-      self._powermonitor_process_port = None
-
-  @staticmethod
-  def ParseSamplingOutput(powermonitor_output):
-    """Parse output of powermonitor command line utility.
-
-    Returns:
-        Dictionary in the format returned by StopMonitoringPower().
-    """
-    power_samples = []
-    total_energy_consumption_mwh = 0
-    def ParseSample(sample):
-      values = [float(x) for x in sample.split(' ')]
-      res = {}
-      (res['timestamp_s'],
-       res['charge_nah'],
-       res['current_ua'],
-       res['voltage_uv']) = values
-      return res
-    # The output contains a sample per line.
-    samples = map(ParseSample, powermonitor_output.split('\n')[:-1])
-    # Keep track of the last sample that found an updated reading.
-    last_updated_sample = samples[0]
-    # Compute average voltage.
-    voltage_sum_uv = 0
-    voltage_count = 0
-    for sample in samples:
-      if sample['charge_nah'] != last_updated_sample['charge_nah']:
-        charge_difference_nah = (sample['charge_nah'] -
-                                 last_updated_sample['charge_nah'])
-        # Use average voltage for the energy consumption.
-        voltage_sum_uv += sample['voltage_uv']
-        voltage_count += 1
-        average_voltage_uv = voltage_sum_uv / voltage_count
-        total_energy_consumption_mwh += (-charge_difference_nah *
-                                         average_voltage_uv / 10 ** 12)
-        last_updated_sample = sample
-        voltage_sum_uv = 0
-        voltage_count = 0
-      # Update average voltage.
-      voltage_sum_uv += sample['voltage_uv']
-      voltage_count += 1
-      # Compute energy of the sample.
-      energy_consumption_mw = (-sample['current_ua'] * sample['voltage_uv'] /
-                               10 ** 9)
-
-      power_samples.append(energy_consumption_mw)
-    # Because the data is stalled for a few seconds, compute the remaining
-    # energy consumption using the last available current reading.
-    last_sample = samples[-1]
-    remaining_time_h = (
-        last_sample['timestamp_s'] - last_updated_sample['timestamp_s']) / 3600
-    average_voltage_uv = voltage_sum_uv / voltage_count
-
-    remaining_energy_consumption_mwh = (-last_updated_sample['current_ua'] *
-                                        average_voltage_uv *
-                                        remaining_time_h  / 10 ** 9)
-    total_energy_consumption_mwh += remaining_energy_consumption_mwh
-
-    # -------- Collect and Process Data -------------
-    out_dict = {}
-    # Raw power usage samples.
-    out_dict['identifier'] = 'ds2784'
-    out_dict['power_samples_mw'] = power_samples
-    out_dict['energy_consumption_mwh'] = total_energy_consumption_mwh
-
-    return out_dict

tools/telemetry/telemetry/internal/platform/power_monitor/android_ds2784_power_monitor_unittest.py

-# 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.
-
-import unittest
-
-# pylint: disable=C0301
-from telemetry.internal.platform.power_monitor import android_ds2784_power_monitor
-# pylint: enable=C0301
-
-
-class DS2784PowerMonitorMonitorTest(unittest.TestCase):
-  def testEnergyComsumption(self):
-
-    data = ('0000 1000 -10 12\n'
-            '1800 1000 -10 11\n'
-            '3600 1000 -10 09\n'
-            '5400 0000 -20 08\n'
-            '7200 0000 -20 11\n'
-            '9000 0000 -20 11\n')
-    results = (
-        android_ds2784_power_monitor.DS2784PowerMonitor.ParseSamplingOutput(
-            data))
-    self.assertEqual(results['power_samples_mw'], [1.2e-07, 1.1e-07, 9e-08,
-                                                   1.6e-07, 2.2e-07, 2.2e-07])
-    self.assertEqual(results['energy_consumption_mwh'], 2.1e-07)