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/**
* Copyright © 2016 IBM Corporation
*
* 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 <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
int Monitor::openDevice()
{
using namespace phosphor::logging;
int fd = open(path.c_str(), O_RDONLY | O_NONBLOCK);
if (fd < 0)
{
log<level::ERR>("Failed to open device",
entry("PATH=%s", path.c_str()));
throw std::runtime_error("Failed to open device");
}
return fd;
}
// Attaches the FD to event loop and registers the callback handler
void Monitor::registerCallback()
{
decltype(eventSource.get()) sourcePtr = nullptr;
auto r = sd_event_add_io(event.get(), &sourcePtr, (fd)(),
EPOLLIN, callbackHandler, this);
eventSource.reset(sourcePtr);
if (r < 0)
{
log<level::ERR>("Failed to register callback handler",
entry("ERROR=%s", strerror(-r)));
throw std::runtime_error("Failed to register callback handler");
}
}
// Initializes the event device with the fd
void Monitor::initEvDev()
{
if (device)
{
// Init can be done only once per device
return;
}
struct libevdev* evdev = nullptr;
auto rc = libevdev_new_from_fd((fd)(), &evdev);
if (rc < 0)
{
log<level::ERR>("Failed to initialize evdev");
throw std::runtime_error("Failed to initialize evdev");
}
// Packing in the unique_ptr
device.reset(evdev);
evdev = nullptr;
}
// Callback handler when there is an activity on the FD
int Monitor::processEvents(sd_event_source* es, int fd,
uint32_t revents, void* userData)
{
log<level::INFO>("GPIO line altered");
auto monitor = static_cast<Monitor*>(userData);
// Initialize libevdev for this. Doing it here enables
// gtest to use this infrastructure on arbitrary device
// than /dev/input/
monitor->initEvDev();
monitor->analyzeEvent();
return 0;
}
// Analyzes the GPIO event
void Monitor::analyzeEvent()
{
// Data returned
struct input_event ev{};
int rc = 0;
// While testing, observed that not having a loop here was leading
// into events being missed.
while (rc >= 0)
{
// Wait until no more events are available on the device.
rc = libevdev_next_event(device.get(),
LIBEVDEV_READ_FLAG_NORMAL, &ev);
if (rc < 0)
{
// There was an error waiting for events, mostly that there are no
// events to be read.. So continue waiting...
return;
};
if (rc == LIBEVDEV_READ_STATUS_SUCCESS)
{
if (ev.type == EV_SYN && ev.code == SYN_REPORT)
{
continue;
}
else if (ev.code == key && ev.value == polarity)
{
// If the code/value is what we are interested in, declare done.
// User supplied systemd unit
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");
bus.call_noreply(method);
}
// This marks the completion of handling the gpio assertion
// and the app can exit
complete = true;
return;
}
}
};
return;
}
} // namespace gpio
} // namespace phosphor
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