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mirror of https://github.com/binary-kitchen/doorlockd synced 2024-11-10 18:00:31 +01:00
doorlockd-mirror/gpio-wait.c
Ralf Ramsauer b9a1bfc566 Publish door state to mqtt
Assisted by nice gpio-wait helper.

Signed-off-by: Ralf Ramsauer <ralf@binary-kitchen.de>
2018-10-07 01:50:41 +02:00

101 lines
2.1 KiB
C

/*
* Doorlockd -- Binary Kitchen's smart door opener
*
* Copyright (c) Binary Kitchen e.V., 2018
*
* Author: Ralf Ramsauer <ralf@binary-kitchen.de>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the LICENSE file in the top-level directory.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*/
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <linux/gpio.h>
int main(int argc, const char **argv) {
int gpiochip_fd, ret;
struct gpioevent_request req;
struct gpiohandle_data data;
struct gpioevent_data event;
if (argc != 3) {
fprintf(stderr, "Usage: %s gpiochip pin\n", argv[0]);
return -1;
}
gpiochip_fd = open(argv[1], 0);
if (gpiochip_fd == -1) {
perror("open");
return -1;
}
req.lineoffset = atoi(argv[2]);
req.handleflags = GPIOHANDLE_REQUEST_INPUT;
req.eventflags = GPIOEVENT_REQUEST_RISING_EDGE | GPIOEVENT_REQUEST_FALLING_EDGE;
req.consumer_label[0] = 0;
ret = ioctl(gpiochip_fd, GPIO_GET_LINEEVENT_IOCTL, &req);
if (ret == -1) {
perror("ioctl");
goto gpiochip_out;
}
ret = ioctl(req.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
if (ret == -1) {
perror("ioctl");
goto req_fd_out;
}
printf("Initial Value: %u\n", data.values[0]);
retry:
ret = read(req.fd, &event, sizeof(event));
if (ret == -1) {
if (errno == -EAGAIN) {
printf("Nothing available, trying again\n");
goto retry;
}
}
if (ret != sizeof(event)) {
ret = -EIO;
goto req_fd_out;
}
switch (event.id) {
case GPIOEVENT_EVENT_RISING_EDGE:
printf("Detected rising edge\n");
ret = 1;
break;
case GPIOEVENT_EVENT_FALLING_EDGE:
printf("Detected falling edge\n");
ret = 0;
break;
default:
printf("Unknown event\n");
ret = -EIO;
break;
}
req_fd_out:
close(req.fd);
gpiochip_out:
close(gpiochip_fd);
return ret;
}