xref: /openbmc/phosphor-pid-control/pid/ec/stepwise.cpp (revision f8b6e55147148c3cfb42327ff267197a460b411c)
1 /*
2 // Copyright (c) 2018 Intel 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 
17 #include "stepwise.hpp"
18 
19 #include <cmath>
20 #include <cstddef>
21 
22 namespace pid_control
23 {
24 namespace ec
25 {
26 
stepwise(const ec::StepwiseInfo & info,double input)27 double stepwise(const ec::StepwiseInfo& info, double input)
28 {
29     double value = info.output[0]; // if we are below the lowest
30                                    // point, we set the lowest value
31 
32     for (size_t ii = 1; ii < ec::maxStepwisePoints; ii++)
33     {
34         if (std::isnan(info.reading[ii]))
35         {
36             break;
37         }
38         if (info.reading[ii] > input)
39         {
40             break;
41         }
42         value = info.output[ii];
43     }
44 
45     return value;
46 }
47 
48 } // namespace ec
49 } // namespace pid_control
50