Add phosphor-multi-gpio-presence

The new service works like phosphor-gpio-presence, but uses libgpiod
and can monitor an arbitrary amount of GPIOs.

The driver loading feature hasn't been ported to the new service.

Change-Id: I412345f804208e48eec40ec020b3a0d8f668a34b
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
diff --git a/multi-presence/main.cpp b/multi-presence/main.cpp
new file mode 100644
index 0000000..4b631d9
--- /dev/null
+++ b/multi-presence/main.cpp
@@ -0,0 +1,195 @@
+/**
+ * Copyright © 2019 Facebook
+ * Copyright © 2023 9elements GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "gpio_presence.hpp"
+
+#include <CLI/CLI.hpp>
+#include <boost/asio/io_context.hpp>
+#include <nlohmann/json.hpp>
+#include <phosphor-logging/lg2.hpp>
+
+#include <fstream>
+
+namespace phosphor
+{
+namespace gpio
+{
+
+const std::map<std::string, int> biasMap = {
+    /**< Set bias as is. */
+    {"AS_IS", 0},
+    /**< Disable bias. */
+    {"DISABLE", GPIOD_LINE_REQUEST_FLAG_BIAS_DISABLE},
+    /**< Enable pull-up. */
+    {"PULL_UP", GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_UP},
+    /**< Enable pull-down. */
+    {"PULL_DOWN", GPIOD_LINE_REQUEST_FLAG_BIAS_PULL_DOWN}};
+}
+} // namespace phosphor
+
+int main(int argc, char** argv)
+{
+    boost::asio::io_context io;
+
+    CLI::App app{"Monitor gpio presence status"};
+
+    std::string gpioFileName;
+
+    /* Add an input option */
+    app.add_option("-c,--config", gpioFileName, "Name of config json file")
+        ->required()
+        ->check(CLI::ExistingFile);
+
+    /* Parse input parameter */
+    try
+    {
+        app.parse(argc, argv);
+    }
+    catch (const CLI::Error& e)
+    {
+        return app.exit(e);
+    }
+
+    /* Get list of gpio config details from json file */
+    std::ifstream file(gpioFileName);
+    if (!file)
+    {
+        lg2::error("Failed to open config file: {FILE}", "FILE", gpioFileName);
+        return -1;
+    }
+
+    nlohmann::json gpioMonObj;
+    file >> gpioMonObj;
+    file.close();
+
+    std::vector<phosphor::gpio::GpioPresence> gpios;
+
+    for (auto& obj : gpioMonObj)
+    {
+        /* GPIO Line message */
+        std::string lineMsg = "GPIO Line ";
+
+        /* GPIO line */
+        gpiod_line* line = NULL;
+
+        /* GPIO line configuration, default to monitor both edge */
+        struct gpiod_line_request_config config
+        {
+            "gpio_monitor", GPIOD_LINE_REQUEST_EVENT_BOTH_EDGES, 0
+        };
+
+        /* Pretty name of the inventory object */
+        std::string name;
+
+        /* Object path under inventory that will be created */
+        std::string inventory;
+
+        /* List of interfaces to associate to inventory item */
+        std::vector<std::string> extraInterfaces;
+
+        if (obj.find("LineName") == obj.end())
+        {
+            /* If there is no line Name defined then gpio num nd chip
+             * id must be defined. GpioNum is integer mapping to the
+             * GPIO key configured by the kernel
+             */
+            if (obj.find("GpioNum") == obj.end() ||
+                obj.find("ChipId") == obj.end())
+            {
+                lg2::error("Failed to find line name or gpio number: {FILE}",
+                           "FILE", gpioFileName);
+                return -1;
+            }
+
+            std::string chipIdStr = obj["ChipId"].get<std::string>();
+            int gpioNum = obj["GpioNum"].get<int>();
+
+            lineMsg += chipIdStr + " " + std::to_string(gpioNum);
+
+            /* Get the GPIO line */
+            line = gpiod_line_get(chipIdStr.c_str(), gpioNum);
+        }
+        else
+        {
+            /* Find the GPIO line */
+            std::string lineName = obj["LineName"].get<std::string>();
+            lineMsg += lineName;
+            line = gpiod_line_find(lineName.c_str());
+        }
+
+        if (line == NULL)
+        {
+            lg2::error("Failed to find the {GPIO}", "GPIO", lineMsg);
+            return -1;
+        }
+
+        /* Parse out inventory argument. */
+        if (obj.find("Inventory") == obj.end())
+        {
+            lg2::error("{GPIO}: Inventory path not specified", "GPIO", lineMsg);
+            return -1;
+        }
+        else
+        {
+            inventory = obj["Inventory"].get<std::string>();
+        }
+
+        if (obj.find("Name") == obj.end())
+        {
+            lg2::error("{GPIO}: Name path not specified", "GPIO", lineMsg);
+            return -1;
+        }
+        else
+        {
+            name = obj["Name"].get<std::string>();
+        }
+
+        /* Parse optional bias */
+        if (obj.find("Bias") != obj.end())
+        {
+            std::string biasName = obj["Bias"].get<std::string>();
+            auto findBias = phosphor::gpio::biasMap.find(biasName);
+            if (findBias == phosphor::gpio::biasMap.end())
+            {
+                lg2::error("{GPIO}: Bias unknown: {BIAS}", "GPIO", lineMsg,
+                           "BIAS", biasName);
+                return -1;
+            }
+
+            config.flags = findBias->second;
+        }
+
+        /* Parse optional active level */
+        if (obj.find("ActiveLow") != obj.end() && obj["ActiveLow"].get<bool>())
+        {
+            config.flags |= GPIOD_LINE_REQUEST_FLAG_ACTIVE_LOW;
+        }
+
+        /* Parse optional extra interfaces */
+        if (obj.find("ExtraInterfaces") != obj.end())
+        {
+            obj.at("ExtraInterfaces").get_to(extraInterfaces);
+        }
+
+        /* Create a monitor object and let it do all the rest */
+        gpios.push_back(phosphor::gpio::GpioPresence(
+            line, config, io, inventory, extraInterfaces, name, lineMsg));
+    }
+    io.run();
+
+    return 0;
+}