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// SPDX-License-Identifier: GPL-2.0-or-later
// SPDX-FileCopyrightText: 2023 Kent Gibson <warthog618@gmail.com>
/* Minimal example of watching for requests on particular lines. */
#include <cstdlib>
#include <gpiod.hpp>
#include <iomanip>
#include <iostream>
namespace {
/* Example configuration - customize to suit your situation. */
const ::std::filesystem::path chip_path("/dev/gpiochip0");
const ::gpiod::line::offsets line_offsets = { 5, 3, 7 };
const char *event_type(const ::gpiod::info_event &event)
{
switch (event.type()) {
case ::gpiod::info_event::event_type::LINE_REQUESTED:
return "Requested";
case ::gpiod::info_event::event_type::LINE_RELEASED:
return "Released";
case ::gpiod::info_event::event_type::LINE_CONFIG_CHANGED:
return "Reconfig";
default:
return "Unknown";
}
}
} /* namespace */
int main()
{
::gpiod::chip chip(chip_path);
for (auto offset :line_offsets)
chip.watch_line_info(offset);
for (;;) {
/* Blocks until at least one event is available */
auto event = chip.read_info_event();
::std::cout << "line: " << event.get_line_info().offset() << " "
<< ::std::setw(9) << ::std::left
<< event_type(event) << " "
<< event.timestamp_ns() / 1000000000 << "."
<< event.timestamp_ns() % 1000000000 << ::std::endl;
}
}
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