1 /**
2  * Copyright © 2016 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 
17 #include "monitor.hpp"
18 
19 #include <fcntl.h>
20 
21 #include <phosphor-logging/log.hpp>
22 
23 namespace phosphor
24 {
25 namespace gpio
26 {
27 
28 // systemd service to kick start a target.
29 constexpr auto SYSTEMD_SERVICE = "org.freedesktop.systemd1";
30 constexpr auto SYSTEMD_ROOT = "/org/freedesktop/systemd1";
31 constexpr auto SYSTEMD_INTERFACE = "org.freedesktop.systemd1.Manager";
32 
33 using namespace phosphor::logging;
34 
35 // Callback handler when there is an activity on the FD
36 int Monitor::processEvents(sd_event_source*, int, uint32_t, void* userData)
37 {
38     log<level::INFO>("GPIO line altered");
39     auto monitor = static_cast<Monitor*>(userData);
40 
41     monitor->analyzeEvent();
42     return 0;
43 }
44 
45 // Analyzes the GPIO event
46 void Monitor::analyzeEvent()
47 {
48     // Data returned
49     struct input_event ev
50     {};
51     int rc = 0;
52 
53     // While testing, observed that not having a loop here was leading
54     // into events being missed.
55     while (rc >= 0)
56     {
57         // Wait until no more events are available on the device.
58         rc = libevdev_next_event(devicePtr.get(), LIBEVDEV_READ_FLAG_NORMAL,
59                                  &ev);
60         if (rc < 0)
61         {
62             // There was an error waiting for events, mostly that there are no
63             // events to be read.. So continue waiting...
64             return;
65         };
66 
67         if (rc == LIBEVDEV_READ_STATUS_SUCCESS)
68         {
69             if (ev.type == EV_SYN && ev.code == SYN_REPORT)
70             {
71                 continue;
72             }
73             else if (ev.code == key && ev.value == polarity)
74             {
75                 // If the code/value is what we are interested in, declare done.
76                 // User supplied systemd unit
77                 if (!target.empty())
78                 {
79                     auto bus = sdbusplus::bus::new_default();
80                     auto method =
81                         bus.new_method_call(SYSTEMD_SERVICE, SYSTEMD_ROOT,
82                                             SYSTEMD_INTERFACE, "StartUnit");
83                     method.append(target);
84                     method.append("replace");
85 
86                     bus.call_noreply(method);
87                 }
88 
89                 if (!continueAfterKeyPress)
90                 {
91                     // This marks the completion of handling the gpio assertion
92                     // and the app can exit
93                     complete = true;
94                 }
95                 return;
96             }
97         }
98     };
99 
100     return;
101 }
102 
103 } // namespace gpio
104 } // namespace phosphor
105