1 #pragma once
2 
3 #include "evdev.hpp"
4 
5 #include <linux/input.h>
6 #include <systemd/sd-event.h>
7 #include <unistd.h>
8 
9 #include <sdbusplus/bus.hpp>
10 
11 #include <string>
12 
13 namespace phosphor
14 {
15 namespace gpio
16 {
17 
18 /** @class Monitor
19  *  @brief Responsible for catching GPIO state change
20  *  condition and starting systemd targets.
21  */
22 class Monitor : public Evdev
23 {
24   public:
25     Monitor() = delete;
26     ~Monitor() = default;
27     Monitor(const Monitor&) = delete;
28     Monitor& operator=(const Monitor&) = delete;
29     Monitor(Monitor&&) = delete;
30     Monitor& operator=(Monitor&&) = delete;
31 
32     /** @brief Constructs Monitor object.
33      *
34      *  @param[in] path     - Path to gpio input device
35      *  @param[in] key      - GPIO key to monitor
36      *  @param[in] polarity - GPIO assertion polarity to look for
37      *  @param[in] target   - systemd unit to be started on GPIO
38      *                        value change
39      *  @param[in] event    - sd_event handler
40      *  @param[in] continueRun - Whether to continue after key pressed
41      *  @param[in] handler  - IO callback handler. Defaults to one in this
42      *                        class
43      *  @param[in] useEvDev - Whether to use EvDev to retrieve events
44      */
Monitor(const std::string & path,decltype(input_event::code)key,decltype(input_event::value)polarity,const std::string & target,EventPtr & event,bool continueRun,sd_event_io_handler_t handler=Monitor::processEvents,bool useEvDev=true)45     Monitor(const std::string& path, decltype(input_event::code) key,
46             decltype(input_event::value) polarity, const std::string& target,
47             EventPtr& event, bool continueRun,
48             sd_event_io_handler_t handler = Monitor::processEvents,
49             bool useEvDev = true) :
50         Evdev(path, key, event, handler, useEvDev), polarity(polarity),
51         target(target), continueAfterKeyPress(continueRun) {};
52 
53     /** @brief Callback handler when the FD has some activity on it
54      *
55      *  @param[in] es       - Populated event source
56      *  @param[in] fd       - Associated File descriptor
57      *  @param[in] revents  - Type of event
58      *  @param[in] userData - User data that was passed during registration
59      *
60      *  @return             - 0 or positive number on success and negative
61      *                        errno otherwise
62      */
63     static int processEvents(sd_event_source* es, int fd, uint32_t revents,
64                              void* userData);
65 
66     /** @brief Returns the completion state of this handler */
completed() const67     inline auto completed() const
68     {
69         return complete;
70     }
71 
72   private:
73     /** @brief GPIO key value that is of interest */
74     decltype(input_event::value) polarity;
75 
76     /** @brief Systemd unit to be started when the condition is met */
77     const std::string& target;
78 
79     /** @brief If the monitor should continue after key press */
80     bool continueAfterKeyPress;
81 
82     /** @brief Completion indicator */
83     bool complete = false;
84 
85     /** @brief Analyzes the GPIO event and starts configured target */
86     void analyzeEvent();
87 };
88 
89 } // namespace gpio
90 } // namespace phosphor
91