1 files changed, 180 insertions, 0 deletions
diff --git a/gpio-util/main.cpp b/gpio-util/main.cpp
index b8801aa..fb56e66 100644
--- a/gpio-util/main.cpp
+++ b/gpio-util/main.cpp
@@ -14,7 +14,187 @@
  * limitations under the License.
  */
 
+/**
+ * This program is a utility for accessing GPIOs.
+ * Actions:
+ *   low:  Set a GPIO low
+ *   high: Set a GPIO high
+ *   low_high: Set a GPIO low, delay if requested, set it high
+ *   high_low: Set a GPIO high, delay if requested, set it low
+ */
+
+#include <algorithm>
+#include <chrono>
+#include <iostream>
+#include <map>
+#include <thread>
+#include <phosphor-logging/log.hpp>
+#include "argument.hpp"
+#include "gpio.hpp"
+
+using namespace phosphor::gpio;
+using namespace phosphor::logging;
+
+typedef void (*gpioFunction)(GPIO&, unsigned int);
+using gpioFunctionMap = std::map<std::string, gpioFunction>;
+
+/**
+ * Sets a GPIO low
+ *
+ * @param[in] gpio - the GPIO object
+ * @param[in] delayInMS - Unused in this function
+ */
+void low(GPIO& gpio, unsigned int delayInMS)
+{
+    gpio.set(GPIO::Value::low);
+}
+
+
+/**
+ * Sets a GPIO high
+ *
+ * @param[in] gpio - the GPIO object
+ * @param[in] delayInMS - Unused in this function
+ */
+void high(GPIO& gpio, unsigned int delayInMS)
+{
+    gpio.set(GPIO::Value::high);
+}
+
+
+/**
+ * Sets a GPIO high, then delays, then sets it low
+ *
+ * @param[in] gpio - the GPIO object
+ * @param[in] delayInMS - The delay in between the sets
+ */
+void highLow(GPIO& gpio, unsigned int delayInMS)
+{
+    gpio.set(GPIO::Value::high);
+
+    std::chrono::milliseconds delay{delayInMS};
+    std::this_thread::sleep_for(delay);
+
+    gpio.set(GPIO::Value::low);
+}
+
+
+/**
+ * Sets a GPIO low, then delays, then sets it high
+ *
+ * @param[in] gpio - the GPIO to write
+ * @param[in] delayInMS - The delay in between the sets
+ */
+void lowHigh(GPIO& gpio, unsigned int delayInMS)
+{
+    gpio.set(GPIO::Value::low);
+
+    std::chrono::milliseconds delay{delayInMS};
+    std::this_thread::sleep_for(delay);
+
+    gpio.set(GPIO::Value::high);
+}
+
+
+/**
+ * The actions supported by this program
+ */
+static const gpioFunctionMap functions
+{
+    {"low", low},
+    {"high", high},
+    {"low_high", lowHigh},
+    {"high_low", highLow}
+};
+
+
+/**
+ * Prints usage and exits the program
+ *
+ * @param[in] err - the error message to print
+ * @param[in] argv - argv from main()
+ */
+void exitWithError(const char* err, char** argv)
+{
+    std::cerr << "ERROR: " << err << "\n";
+    ArgumentParser::usage(argv);
+    exit(EXIT_FAILURE);
+}
+
+
+/**
+ * Returns the number value of the argument passed in.
+ *
+ * @param[in] name - the argument name
+ * @param[in] parser - the argument parser
+ * @param[in] argv - arv from main()
+ */
+template<typename T>
+T getValueFromArg(const char* name,
+                  ArgumentParser& parser,
+                  char** argv)
+{
+    char* p = NULL;
+    auto val = strtol(parser[name].c_str(), &p, 10);
+
+    //strol sets p on error, also we don't allow negative values
+    if (*p || (val < 0))
+    {
+        using namespace std::string_literals;
+        std::string msg = "Invalid "s + name + " value passed in";
+        exitWithError(msg.c_str(), argv);
+    }
+    return static_cast<T>(val);
+}
+
+
 int main(int argc, char** argv)
 {
+    ArgumentParser args(argc, argv);
+
+    auto path = args["path"];
+    if (path == ArgumentParser::emptyString)
+    {
+        exitWithError("GPIO device path not specified", argv);
+    }
+
+    auto action = args["action"];
+    if (action == ArgumentParser::emptyString)
+    {
+        exitWithError("Action not specified", argv);
+    }
+
+    if (args["gpio"] == ArgumentParser::emptyString)
+    {
+        exitWithError("GPIO not specified", argv);
+    }
+
+    auto gpioNum = getValueFromArg<gpioNum_t>("gpio", args, argv);
+
+    //Not all actions require a delay, so not required
+    unsigned int delay = 0;
+    if (args["delay"] != ArgumentParser::emptyString)
+    {
+        delay = getValueFromArg<decltype(delay)>("delay", args, argv);
+    }
+
+    auto function = functions.find(action);
+    if (function == functions.end())
+    {
+        exitWithError("Invalid action value passed in", argv);
+    }
+
+    GPIO gpio{path, gpioNum, GPIO::Direction::output};
+
+    try
+    {
+        function->second(gpio, delay);
+    }
+    catch (std::runtime_error& e)
+    {
+        std::cerr << e.what();
+        return -1;
+    }
+
     return 0;
 }