1 #pragma once
2 #include "evdev.hpp"
3 
4 #include <systemd/sd-event.h>
5 
6 #include <sdbusplus/bus.hpp>
7 
8 #include <cstdlib>
9 #include <experimental/filesystem>
10 #include <string>
11 
12 namespace phosphor
13 {
14 namespace gpio
15 {
16 namespace presence
17 {
18 
19 static constexpr auto deviceField = 0;
20 static constexpr auto pathField = 1;
21 using Device = std::string;
22 using Path = std::experimental::filesystem::path;
23 using Driver = std::tuple<Device, Path>;
24 using Interface = std::string;
25 
26 /** @class Presence
27  *  @brief Responsible for determining and monitoring presence,
28  *  by monitoring GPIO state changes, of inventory items and
29  *  updating D-Bus accordingly.
30  */
31 class Presence : public Evdev
32 {
33     using Property = std::string;
34     using Value = std::variant<bool, std::string>;
35     // Association between property and its value
36     using PropertyMap = std::map<Property, Value>;
37     using Interface = std::string;
38     // Association between interface and the D-Bus property
39     using InterfaceMap = std::map<Interface, PropertyMap>;
40     using Object = sdbusplus::message::object_path;
41     // Association between object and the interface
42     using ObjectMap = std::map<Object, InterfaceMap>;
43 
44   public:
45     Presence() = delete;
46     ~Presence() = default;
47     Presence(const Presence&) = delete;
48     Presence& operator=(const Presence&) = delete;
49     Presence(Presence&&) = delete;
50     Presence& operator=(Presence&&) = delete;
51 
52     /** @brief Constructs Presence object.
53      *
54      *  @param[in] bus       - D-Bus bus Object
55      *  @param[in] inventory - Object path under inventory
56                                to display this inventory item
57      *  @param[in] path      - Device path to read for GPIO pin state
58                                to determine presence of inventory item
59      *  @param[in] key       - GPIO key to monitor
60      *  @param[in] name      - Pretty name of the inventory item
61      *  @param[in] event     - sd_event handler
62      *  @param[in] drivers   - list of device drivers to bind and unbind
63      *  @param[in] ifaces    - list of extra interfaces to associate with the
64      *                         inventory item
65      *  @param[in] handler   - IO callback handler. Defaults to one in this
66      *                        class
67      */
68     Presence(sdbusplus::bus_t& bus, const std::string& inventory,
69              const std::string& path, const unsigned int key,
70              const std::string& name, EventPtr& event,
71              const std::vector<Driver>& drivers,
72              const std::vector<Interface>& ifaces,
73              sd_event_io_handler_t handler = Presence::processEvents) :
74         Evdev(path, key, event, handler, true),
75         bus(bus), inventory(inventory), name(name), drivers(drivers),
76         ifaces(ifaces)
77     {
78         // See if the environment (from configuration file?) has a
79         // DRIVER_BIND_DELAY_MS set.
80         if (char* envDelay = std::getenv("DRIVER_BIND_DELAY_MS"))
81         {
82             // DRIVER_BIND_DELAY_MS environment variable is set.
83             // Update the bind delay (in milliseconds) to the value from the
84             // environment.
85             delay = std::strtoull(envDelay, NULL, 10);
86         }
87         determinePresence();
88     }
89 
90     /** @brief Callback handler when the FD has some activity on it
91      *
92      *  @param[in] es       - Populated event source
93      *  @param[in] fd       - Associated File descriptor
94      *  @param[in] revents  - Type of event
95      *  @param[in] userData - User data that was passed during registration
96      *
97      *  @return             - 0 or positive number on success and negative
98      *                        errno otherwise
99      */
100     static int processEvents(sd_event_source* es, int fd, uint32_t revents,
101                              void* userData);
102 
103   private:
104     /**
105      * @brief Update the present property for the inventory item.
106      *
107      * @param[in] present - What the present property should be set to.
108      */
109     void updateInventory(bool present);
110 
111     /**
112      * @brief Construct the inventory object map for the inventory item.
113      *
114      * @param[in] present - What the present property should be set to.
115      *
116      * @return The inventory object map to update inventory
117      */
118     ObjectMap getObjectMap(bool present);
119 
120     /** @brief Connection for sdbusplus bus */
121     sdbusplus::bus_t& bus;
122 
123     /**
124      * @brief Read the GPIO device to determine initial presence and set
125      *        present property at D-Bus path.
126      */
127     void determinePresence();
128 
129     /** @brief Object path under inventory to display this inventory item */
130     const std::string inventory;
131 
132     /** @brief Delay in milliseconds from present to bind device driver */
133     unsigned int delay = 0;
134 
135     /** @brief Pretty name of the inventory item*/
136     const std::string name;
137 
138     /** @brief Analyzes the GPIO event and update present property*/
139     void analyzeEvent();
140 
141     /** @brief  Vector of path and device tuples to bind/unbind*/
142     const std::vector<Driver> drivers;
143 
144     /** @brief  Vector of extra inventory interfaces to associate with the
145      *          inventory item
146      */
147     const std::vector<Interface> ifaces;
148 
149     /**
150      * @brief Binds or unbinds drivers
151      *
152      * Called when a presence change is detected to either
153      * bind the drivers for the new card or unbind them for
154      * the just removed card.  Operates on the drivers vector.
155      *
156      * Writes <device> to <path>/bind (or unbind)
157      *
158      * @param present - when true, will bind the drivers
159      *                  when false, will unbind them
160      */
161     void bindOrUnbindDrivers(bool present);
162 };
163 
164 /**
165  * @brief Get the service name from the mapper for the
166  *        interface and path passed in.
167  *
168  * @param[in] path      - The D-Bus path name
169  * @param[in] interface - The D-Bus interface name
170  * @param[in] bus       - The D-Bus bus object
171  *
172  * @return The service name
173  */
174 std::string getService(const std::string& path, const std::string& interface,
175                        sdbusplus::bus_t& bus);
176 
177 } // namespace presence
178 } // namespace gpio
179 } // namespace phosphor
180