1 /**
2 * Copyright © 2017 IBM Corporation
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 #include "fallback.hpp"
17
18 #include "fan.hpp"
19 #include "psensor.hpp"
20
21 #include <phosphor-logging/lg2.hpp>
22
23 #include <algorithm>
24
25 namespace phosphor
26 {
27 namespace fan
28 {
29 namespace presence
30 {
31
stateChanged(bool present,PresenceSensor &)32 void Fallback::stateChanged(bool present, PresenceSensor& /*sensor*/)
33 {
34 if (!present)
35 {
36 // Starting with the first backup, find the first
37 // sensor that reports the fan as present, if any.
38 auto it = std::find_if(std::next(activeSensor), sensors.end(),
39 [](auto& s) { return s.get().present(); });
40
41 if (it != sensors.end())
42 {
43 // A backup sensor disagrees with the active sensor.
44 // Switch to the backup.
45 activeSensor->get().stop();
46 present = it->get().start();
47
48 while (activeSensor != it)
49 {
50 // Callout the broken sensors.
51 activeSensor->get().fail();
52 ++activeSensor;
53 }
54 lg2::info("Using backup presence sensor for fan {FAN}", "FAN",
55 std::get<1>(fan));
56 activeSensor = it;
57 }
58 }
59
60 setPresence(fan, present);
61
62 if (eepromDevice)
63 {
64 if (present)
65 {
66 eepromDevice->bind();
67 }
68 else
69 {
70 eepromDevice->unbind();
71 }
72 }
73 }
74
monitor()75 void Fallback::monitor()
76 {
77 // Find the first sensor that says the fan is present
78 // and set it as the active sensor.
79 activeSensor = std::find_if(sensors.begin(), sensors.end(), [](auto& s) {
80 return s.get().present();
81 });
82 if (activeSensor == sensors.end())
83 {
84 // The first sensor is working or all sensors
85 // agree the fan isn't present. Use the first sensor.
86 activeSensor = sensors.begin();
87 }
88
89 if (activeSensor != sensors.begin())
90 {
91 lg2::info("Using backup presence sensor for fan {FAN}", "FAN",
92 std::get<1>(fan));
93 }
94
95 // Callout the broken sensors.
96 auto it = sensors.begin();
97 while (it != activeSensor)
98 {
99 it->get().fail();
100 ++it;
101 }
102
103 // Start the active sensor and set the initial state.
104 setPresence(fan, activeSensor->get().start());
105 }
106
107 } // namespace presence
108 } // namespace fan
109 } // namespace phosphor
110