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1# Copyright 2015 The Chromium OS 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"""This module provides the utilities for bluetooth audio using chameleon."""
6
7import logging
8import time
9
10from autotest_lib.client.bin import utils
11
12
13_PIN = '0000'
14_SEARCH_TIMEOUT = 30.0
15_PAIRING_TIMEOUT = 5.0
16_SLEEP_AFTER_DISCONNECT = 20.0
17# When device is busy, a trial may take more than 15 seconds.
18# Set the timeout to 90 seconds so device can take more trials to reconnect.
19_CONNECT_TIMEOUT = 90.0
20
21class ChameleonBluetoothAudioError(Exception):
22    """Error in this module."""
23    pass
24
25
26def connect_bluetooth_module_full_flow(bt_adapter, target_mac_address,
27                             timeout=_SEARCH_TIMEOUT):
28    """Controls Cros device to connect to bluetooth module on audio board.
29
30    @param bt_adapter: A BluetoothDevice object to control bluetooth adapter
31                       on Cros device.
32    @param target_mac_address: The MAC address of bluetooth module to be
33                               connected.
34    @param timeout: Timeout in seconds to search for bluetooth module.
35
36    @raises: ChameleonBluetoothAudioError if Cros device fails to connect to
37             bluetooth module on audio board.
38
39    """
40    # Resets bluetooth adapter on Cros device.
41    if not bt_adapter.reset_on():
42        raise ChameleonBluetoothAudioError(
43                'Failed to reset bluetooth adapter on Cros host.'
44                ' You should check if controller is available on Cros host'
45                ' using bluetoothctl.')
46
47    # Starts discovery mode of bluetooth adapter.
48    if not bt_adapter.start_discovery():
49        raise ChameleonBluetoothAudioError(
50                'Failed to start discovery on bluetooth adapter on Cros host')
51
52    def _find_device():
53        """Controls bluetooth adapter to search for bluetooth module.
54
55        @returns: True if there is a bluetooth device with MAC address
56                  matches target_mac_address. False otherwise.
57
58        """
59        return bt_adapter.has_device(target_mac_address)
60
61    # Searches for bluetooth module with given MAC address.
62    found_device = utils.wait_for_value(_find_device, True, timeout_sec=timeout)
63
64    if not found_device:
65        raise ChameleonBluetoothAudioError(
66                'Can not find bluetooth module with MAC address %s' %
67                target_mac_address)
68
69    pair_legacy_bluetooth_module(bt_adapter, target_mac_address)
70
71    # Disconnects from bluetooth module to clean up the state.
72    if not bt_adapter.disconnect_device(target_mac_address):
73        raise ChameleonBluetoothAudioError(
74                'Failed to let Cros device disconnect from bluetooth module %s' %
75                target_mac_address)
76    time.sleep(_SLEEP_AFTER_DISCONNECT)
77
78    # Connects to bluetooth module.
79    connect_bluetooth_module(bt_adapter, target_mac_address)
80
81    logging.info('Bluetooth module at %s is connected', target_mac_address)
82
83
84def connect_bluetooth_module(bt_adapter, target_mac_address,
85                             timeout=_CONNECT_TIMEOUT):
86    """Controls Cros device to connect to bluetooth module on audio board.
87
88    @param bt_adapter: A BluetoothDevice object to control bluetooth adapter
89                       on Cros device.
90    @param target_mac_address: The MAC address of bluetooth module to be
91                               connected.
92    @param timeout: Timeout in seconds to connect bluetooth module.
93
94    @raises: ChameleonBluetoothAudioError if Cros device fails to connect to
95             bluetooth module on audio board.
96
97    """
98    def _connect_device():
99        logging.info('Try to connect to device')
100        success = bt_adapter.connect_device(target_mac_address)
101        if not success:
102            logging.debug('Can not connect device, retry in 1 second.')
103            time.sleep(1)
104            return False
105        logging.debug('Connection established.')
106        return True
107
108    # Connects bluetooth module with given MAC address.
109    connected = utils.wait_for_value(_connect_device, True, timeout_sec=timeout)
110    if not connected:
111        raise ChameleonBluetoothAudioError(
112                'Failed to let Cros device connect to bluetooth module %s' %
113                target_mac_address)
114
115
116def pair_legacy_bluetooth_module(bt_adapter, target_mac_address, pin=_PIN,
117                                 pairing_timeout=_PAIRING_TIMEOUT, retries=3):
118    """Pairs Cros device bluetooth adapter with legacy bluetooth module.
119
120    @param bt_adapter: A BluetoothDevice object to control bluetooth adapter
121                       on Cros device.
122    @param target_mac_address: The MAC address of bluetooth module to be
123                               paired.
124    @param pin: The pin for legacy pairing.
125    @param timeout: Timeout in seconds to pair bluetooth module in a trial.
126    @param retries: Number of retries if pairing fails.
127
128    @raises: ChameleonBluetoothAudioError if Cros device fails to pair
129             bluetooth module on audio board after all the retries.
130
131    """
132    # Pairs the bluetooth adapter with bluetooth module.
133    for trial in xrange(retries):
134        if bt_adapter.pair_legacy_device(
135            target_mac_address, pin, False, pairing_timeout):
136                logging.debug('Pairing to %s succeeded', target_mac_address)
137                return
138        elif trial == retries - 1:
139            raise ChameleonBluetoothAudioError(
140                    'Failed to pair Cros device and bluetooth module %s' %
141                    target_mac_address)
142
143        logging.debug('Retry for pairing...')
144