forked from Minki/linux
tools/gpio: add the gpio-event-mon tool
The gpio-event-mon is used from userspace as an example of how to monitor GPIO line events. It will latch on to a certain GPIO line on a certain gpiochip and print timestamped events as they arrive. Example output: $ gpio-event-mon -n gpiochip2 -o 0 -r -f Monitoring line 0 on gpiochip2 Initial line value: 1 GPIO EVENT 946685798487609863: falling edge GPIO EVENT 946685798732482910: rising edge GPIO EVENT 946685799115997314: falling edge GPIO EVENT 946685799381469726: rising edge Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Linus Walleij
parent
61f922db72
commit
97f69747d8
@ -1,13 +1,14 @@
|
||||
CC = $(CROSS_COMPILE)gcc
|
||||
CFLAGS += -O2 -Wall -g -D_GNU_SOURCE
|
||||
|
||||
all: lsgpio gpio-hammer
|
||||
all: lsgpio gpio-hammer gpio-event-mon
|
||||
|
||||
lsgpio: lsgpio.o gpio-utils.o
|
||||
gpio-hammer: gpio-hammer.o gpio-utils.o
|
||||
gpio-event-mon: gpio-event-mon.o gpio-utils.o
|
||||
|
||||
%.o: %.c gpio-utils.h
|
||||
|
||||
.PHONY: clean
|
||||
clean:
|
||||
rm -f *.o lsgpio gpio-hammer
|
||||
rm -f *.o lsgpio gpio-hammer gpio-event-mon
|
||||
|
||||
192
tools/gpio/gpio-event-mon.c
Normal file
192
tools/gpio/gpio-event-mon.c
Normal file
@ -0,0 +1,192 @@
|
||||
/*
|
||||
* gpio-hammer - example swiss army knife to shake GPIO lines on a system
|
||||
*
|
||||
* Copyright (C) 2016 Linus Walleij
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify it
|
||||
* under the terms of the GNU General Public License version 2 as published by
|
||||
* the Free Software Foundation.
|
||||
*
|
||||
* Usage:
|
||||
* gpio-event-mon -n <device-name> -o <offset>
|
||||
*/
|
||||
|
||||
#include <unistd.h>
|
||||
#include <stdlib.h>
|
||||
#include <stdbool.h>
|
||||
#include <stdio.h>
|
||||
#include <dirent.h>
|
||||
#include <errno.h>
|
||||
#include <string.h>
|
||||
#include <poll.h>
|
||||
#include <fcntl.h>
|
||||
#include <getopt.h>
|
||||
#include <inttypes.h>
|
||||
#include <sys/ioctl.h>
|
||||
#include <linux/gpio.h>
|
||||
|
||||
int monitor_device(const char *device_name,
|
||||
unsigned int line,
|
||||
u_int32_t handleflags,
|
||||
u_int32_t eventflags,
|
||||
unsigned int loops)
|
||||
{
|
||||
struct gpioevent_request req;
|
||||
struct gpiohandle_data data;
|
||||
char *chrdev_name;
|
||||
int fd;
|
||||
int ret;
|
||||
int i = 0;
|
||||
|
||||
ret = asprintf(&chrdev_name, "/dev/%s", device_name);
|
||||
if (ret < 0)
|
||||
return -ENOMEM;
|
||||
|
||||
fd = open(chrdev_name, 0);
|
||||
if (fd == -1) {
|
||||
ret = -errno;
|
||||
fprintf(stderr, "Failed to open %s\n", chrdev_name);
|
||||
goto exit_close_error;
|
||||
}
|
||||
|
||||
req.lineoffset = line;
|
||||
req.handleflags = handleflags;
|
||||
req.eventflags = eventflags;
|
||||
strcpy(req.consumer_label, "gpio-event-mon");
|
||||
|
||||
ret = ioctl(fd, GPIO_GET_LINEEVENT_IOCTL, &req);
|
||||
if (ret == -1) {
|
||||
ret = -errno;
|
||||
fprintf(stderr, "Failed to issue GET EVENT "
|
||||
"IOCTL (%d)\n",
|
||||
ret);
|
||||
goto exit_close_error;
|
||||
}
|
||||
|
||||
/* Read initial states */
|
||||
ret = ioctl(req.fd, GPIOHANDLE_GET_LINE_VALUES_IOCTL, &data);
|
||||
if (ret == -1) {
|
||||
ret = -errno;
|
||||
fprintf(stderr, "Failed to issue GPIOHANDLE GET LINE "
|
||||
"VALUES IOCTL (%d)\n",
|
||||
ret);
|
||||
goto exit_close_error;
|
||||
}
|
||||
|
||||
fprintf(stdout, "Monitoring line %d on %s\n", line, device_name);
|
||||
fprintf(stdout, "Initial line value: %d\n", data.values[0]);
|
||||
|
||||
while (1) {
|
||||
struct gpioevent_data event;
|
||||
|
||||
ret = read(req.fd, &event, sizeof(event));
|
||||
if (ret == -1) {
|
||||
if (errno == -EAGAIN) {
|
||||
fprintf(stderr, "nothing available\n");
|
||||
continue;
|
||||
} else {
|
||||
ret = -errno;
|
||||
fprintf(stderr, "Failed to read event (%d)\n",
|
||||
ret);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (ret != sizeof(event)) {
|
||||
fprintf(stderr, "Reading event failed\n");
|
||||
ret = -EIO;
|
||||
break;
|
||||
}
|
||||
fprintf(stdout, "GPIO EVENT %" PRIu64 ": ", event.timestamp);
|
||||
switch (event.id) {
|
||||
case GPIOEVENT_EVENT_RISING_EDGE:
|
||||
fprintf(stdout, "rising edge");
|
||||
break;
|
||||
case GPIOEVENT_EVENT_FALLING_EDGE:
|
||||
fprintf(stdout, "falling edge");
|
||||
break;
|
||||
default:
|
||||
fprintf(stdout, "unknown event");
|
||||
}
|
||||
fprintf(stdout, "\n");
|
||||
|
||||
i++;
|
||||
if (i == loops)
|
||||
break;
|
||||
}
|
||||
|
||||
exit_close_error:
|
||||
if (close(fd) == -1)
|
||||
perror("Failed to close GPIO character device file");
|
||||
free(chrdev_name);
|
||||
return ret;
|
||||
}
|
||||
|
||||
void print_usage(void)
|
||||
{
|
||||
fprintf(stderr, "Usage: gpio-event-mon [options]...\n"
|
||||
"Listen to events on GPIO lines, 0->1 1->0\n"
|
||||
" -n <name> Listen on GPIOs on a named device (must be stated)\n"
|
||||
" -o <n> Offset to monitor\n"
|
||||
" -d Set line as open drain\n"
|
||||
" -s Set line as open source\n"
|
||||
" -r Listen for rising edges\n"
|
||||
" -f Listen for falling edges\n"
|
||||
" [-c <n>] Do <n> loops (optional, infinite loop if not stated)\n"
|
||||
" -? This helptext\n"
|
||||
"\n"
|
||||
"Example:\n"
|
||||
"gpio-event-mon -n gpiochip0 -o 4 -r -f\n"
|
||||
);
|
||||
}
|
||||
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
const char *device_name = NULL;
|
||||
unsigned int line = -1;
|
||||
unsigned int loops = 0;
|
||||
u_int32_t handleflags = GPIOHANDLE_REQUEST_INPUT;
|
||||
u_int32_t eventflags = 0;
|
||||
int c;
|
||||
|
||||
while ((c = getopt(argc, argv, "c:n:o:dsrf?")) != -1) {
|
||||
switch (c) {
|
||||
case 'c':
|
||||
loops = strtoul(optarg, NULL, 10);
|
||||
break;
|
||||
case 'n':
|
||||
device_name = optarg;
|
||||
break;
|
||||
case 'o':
|
||||
line = strtoul(optarg, NULL, 10);
|
||||
break;
|
||||
case 'd':
|
||||
handleflags |= GPIOHANDLE_REQUEST_OPEN_DRAIN;
|
||||
break;
|
||||
case 's':
|
||||
handleflags |= GPIOHANDLE_REQUEST_OPEN_SOURCE;
|
||||
break;
|
||||
case 'r':
|
||||
eventflags |= GPIOEVENT_REQUEST_RISING_EDGE;
|
||||
break;
|
||||
case 'f':
|
||||
eventflags |= GPIOEVENT_REQUEST_FALLING_EDGE;
|
||||
break;
|
||||
case '?':
|
||||
print_usage();
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
|
||||
if (!device_name || line == -1) {
|
||||
print_usage();
|
||||
return -1;
|
||||
}
|
||||
if (!eventflags) {
|
||||
printf("No flags specified, listening on both rising and "
|
||||
"falling edges\n");
|
||||
eventflags = GPIOEVENT_REQUEST_BOTH_EDGES;
|
||||
}
|
||||
return monitor_device(device_name, line, handleflags,
|
||||
eventflags, loops);
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user