Add cxx equivalents of the core examples.
Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
gpiomoncxx
gpionotifycxx
gpiosetcxx
+async_watch_line_value
+get_line_value
+toggle_line_value
+watch_line_value
gpioinfocxx \
gpiomoncxx \
gpionotifycxx \
- gpiosetcxx
+ gpiosetcxx \
+ async_watch_line_value \
+ get_line_value \
+ toggle_line_value \
+ watch_line_value
gpiodetectcxx_SOURCES = gpiodetectcxx.cpp
gpionotifycxx_SOURCES = gpionotifycxx.cpp
gpiosetcxx_SOURCES = gpiosetcxx.cpp
+
+async_watch_line_value_SOURCES = async_watch_line_value.cpp
+
+get_line_value_SOURCES = get_line_value.cpp
+
+toggle_line_value_SOURCES = toggle_line_value.cpp
+
+watch_line_value_SOURCES = watch_line_value.cpp
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Kent Gibson <warthog618@gmail.com>
+
+/* Minimal example of asynchronously watching for edges on a single line. */
+
+#include <cstdlib>
+#include <cstring>
+#include <filesystem>
+#include <gpiod.hpp>
+#include <iostream>
+#include <poll.h>
+
+namespace {
+
+/* Example configuration - customize to suit your situation. */
+const ::std::filesystem::path chip_path("/dev/gpiochip0");
+const ::gpiod::line::offset line_offset = 5;
+
+const char* edge_event_type_str(const ::gpiod::edge_event &event)
+{
+ switch (event.type()) {
+ case ::gpiod::edge_event::event_type::RISING_EDGE:
+ return "Rising ";
+ case ::gpiod::edge_event::event_type::FALLING_EDGE:
+ return "Falling";
+ default:
+ return "Unknown";
+ }
+}
+
+} /* namespace */
+
+int main(void)
+{
+ /*
+ * Assume a button connecting the pin to ground, so pull it up and
+ * provide some debounce.
+ */
+ auto request =
+ ::gpiod::chip(chip_path)
+ .prepare_request()
+ .set_consumer("async-watch-line-value")
+ .add_line_settings(
+ line_offset,
+ ::gpiod::line_settings()
+ .set_direction(
+ ::gpiod::line::direction::INPUT)
+ .set_edge_detection(
+ ::gpiod::line::edge::BOTH)
+ .set_bias(::gpiod::line::bias::PULL_UP)
+ .set_debounce_period(
+ std::chrono::milliseconds(10)))
+ .do_request();
+
+ /*
+ * A larger buffer is an optimisation for reading bursts of events from
+ * the kernel, but that is not necessary in this case, so 1 is fine.
+ */
+ ::gpiod::edge_event_buffer buffer(1);
+
+ struct pollfd pollfd;
+ pollfd.fd = request.fd();
+ pollfd.events = POLLIN;
+
+ for (;;) {
+ /*
+ * Other fds could be registered with the poll and be handled
+ * separately using the pollfd.revents after poll()
+ */
+ auto ret = poll(&pollfd, 1, -1);
+ if (ret == -1) {
+ ::std::cerr << "error waiting for edge events: "
+ << strerror(errno) << ::std::endl;
+
+ return EXIT_FAILURE;
+ }
+
+ request.read_edge_events(buffer);
+
+ for (const auto& event : buffer)
+ ::std::cout << "offset: " << event.line_offset()
+ << ", type: " << edge_event_type_str(event)
+ << ", event #" << event.line_seqno()
+ << ::std::endl;
+ }
+
+ return EXIT_SUCCESS;
+}
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Kent Gibson <warthog618@gmail.com>
+
+/* Minimal example of reading a single line. */
+
+#include <cstdlib>
+#include <filesystem>
+#include <gpiod.hpp>
+#include <iostream>
+
+namespace {
+
+/* example configuration - customize to suit your situation */
+const ::std::filesystem::path chip_path("/dev/gpiochip0");
+const ::gpiod::line::offset line_offset = 5;
+
+} /* namespace */
+
+int main(void)
+{
+ auto request =
+ ::gpiod::chip(chip_path)
+ .prepare_request()
+ .set_consumer("get-line-value")
+ .add_line_settings(
+ line_offset,
+ ::gpiod::line_settings().set_direction(
+ ::gpiod::line::direction::INPUT))
+ .do_request();
+
+ ::std::cout << request.get_value(line_offset) << ::std::endl;
+
+ return EXIT_SUCCESS;
+}
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Kent Gibson <warthog618@gmail.com>
+
+/* Minimal example of toggling a single line. */
+
+#include <cstdlib>
+#include <chrono>
+#include <filesystem>
+#include <iostream>
+#include <gpiod.hpp>
+#include <thread>
+
+namespace {
+
+/* Example configuration - customize to suit your situation. */
+const ::std::filesystem::path chip_path("/dev/gpiochip0");
+const ::gpiod::line::offset line_offset = 5;
+
+::gpiod::line::value toggle_value(::gpiod::line::value v)
+{
+ return (v == ::gpiod::line::value::ACTIVE) ?
+ ::gpiod::line::value::INACTIVE :
+ ::gpiod::line::value::ACTIVE;
+}
+
+} /* namespace */
+
+int main(void)
+{
+ ::gpiod::line::value val = ::gpiod::line::value::ACTIVE;
+
+ auto request =
+ ::gpiod::chip(chip_path)
+ .prepare_request()
+ .set_consumer("toggle-line-value")
+ .add_line_settings(
+ line_offset,
+ ::gpiod::line_settings().set_direction(
+ ::gpiod::line::direction::OUTPUT))
+ .do_request();
+
+ for (;;) {
+ ::std::cout << val << ::std::endl;
+
+ std::this_thread::sleep_for(std::chrono::seconds(1));
+ val = toggle_value(val);
+ request.set_value(line_offset, val);
+ }
+
+ return EXIT_SUCCESS;
+}
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Kent Gibson <warthog618@gmail.com>
+
+/* Minimal example of watching for edges on a single line. */
+
+#include <cstdlib>
+#include <filesystem>
+#include <gpiod.hpp>
+#include <iostream>
+
+namespace {
+
+/* Example configuration - customize to suit your situation. */
+const ::std::filesystem::path chip_path("/dev/gpiochip0");
+const ::gpiod::line::offset line_offset = 5;
+
+const char *edge_event_type_str(const ::gpiod::edge_event &event)
+{
+ switch (event.type()) {
+ case ::gpiod::edge_event::event_type::RISING_EDGE:
+ return "Rising ";
+ case ::gpiod::edge_event::event_type::FALLING_EDGE:
+ return "Falling";
+ default:
+ return "Unknown";
+ }
+}
+
+} /* namespace */
+
+int main(void)
+{
+ /*
+ * Assume a button connecting the pin to ground, so pull it up and
+ * provide some debounce.
+ */
+ auto request =
+ ::gpiod::chip(chip_path)
+ .prepare_request()
+ .set_consumer("watch-line-value")
+ .add_line_settings(
+ line_offset,
+ ::gpiod::line_settings()
+ .set_direction(
+ ::gpiod::line::direction::INPUT)
+ .set_edge_detection(
+ ::gpiod::line::edge::BOTH)
+ .set_bias(::gpiod::line::bias::PULL_UP)
+ .set_debounce_period(
+ std::chrono::milliseconds(10)))
+ .do_request();
+
+ /*
+ * A larger buffer is an optimisation for reading bursts of events from
+ * the kernel, but that is not necessary in this case, so 1 is fine.
+ */
+ ::gpiod::edge_event_buffer buffer(1);
+
+ for (;;) {
+ /* Blocks until at least one event is available. */
+ request.read_edge_events(buffer);
+
+ for (const auto &event : buffer)
+ ::std::cout << "offset: " << event.line_offset()
+ << ", type: " << edge_event_type_str(event)
+ << ", event #" << event.line_seqno()
+ << ::std::endl;
+ }
+
+ return EXIT_SUCCESS;
+}
projects / qemu-gpiodev / libgpiod.git / commitdiff