Call defined target when GPIO line is asserted

Change-Id: Ia5445a8d6585acfec69783ba158c8d866d526e97
Signed-off-by: Vishwanatha Subbanna <vishwa@linux.vnet.ibm.com>

1 files changed, 33 insertions, 2 deletions

diff --git a/monitor.cpp b/monitor.cpp
index 5428c09..99eed03 100644
--- a/monitor.cpp
+++ b/monitor.cpp
@@ -17,11 +17,18 @@
 #include <fcntl.h>
 #include <phosphor-logging/log.hpp>
 #include "monitor.hpp"
+#include "config.h"
+
 namespace phosphor
 {
 namespace gpio
 {
 
+// systemd service to kick start a target.
+constexpr auto SYSTEMD_SERVICE        = "org.freedesktop.systemd1";
+constexpr auto SYSTEMD_ROOT           = "/org/freedesktop/systemd1";
+constexpr auto SYSTEMD_INTERFACE      = "org.freedesktop.systemd1.Manager";
+
 using namespace phosphor::logging;
 
 // Populate the file descriptor for passed in device
@@ -59,8 +66,32 @@ void Monitor::registerCallback()
 int Monitor::processEvents(sd_event_source* es, int fd,
                            uint32_t revents, void* userData)
 {
-    // TODO. This calls into starting configured target
-    log<level::INFO>("Callback handler called");
+    log<level::INFO>("GPIO line altered");
+    auto monitor = static_cast<Monitor*>(userData);
+    // TODO : Need a way to check if the GPIO state change is what we wanted
+    return monitor->analyzeEvent();
+}
+
+// Analyzes the GPIO event
+int Monitor::analyzeEvent()
+{
+    if(!target.empty())
+    {
+        auto bus = sdbusplus::bus::new_default();
+        auto method = bus.new_method_call(SYSTEMD_SERVICE,
+                                          SYSTEMD_ROOT,
+                                          SYSTEMD_INTERFACE,
+                                          "StartUnit");
+        method.append(target);
+        method.append("replace");
+
+        // If there is any error, an exception would be thrown from here.
+        bus.call_noreply(method);
+    }
+
+    // This marks the completion of handling the checkstop and app can exit
+    complete = true;
+
     return 0;
 }