Commit e1d392dc authored by Linus Walleij's avatar Linus Walleij Committed by Jonathan Cameron
Browse files

iio: event_monitor: Enable events before monitoring 



After some painful sessions with a driver that register an
enable/disable sysfs knob (gp2ap002) and manually going
in and enabling the event before monitoring it:

  cd /sys/bus/iio/devices/iio\:device2/events
  # ls
  in_proximity_thresh_either_en
  # echo 1 > in_proximity_thresh_either_en

I realized that it's better if the iio_event_monitor is
smart enough to enable all events by itself and disable them
after use, if passed the -a flag familiar from the
iio_generic_buffer tool.

Auto-enabling events depend on the hardware being able
to handle all events at the same time which isn't
necessarily the case, so a command line option is required
for this.

Cc: Bastien Nocera <hadess@hadess.net>
Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210319135301.542911-1-linus.walleij@linaro.org


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 346e19ec

tools/iio/iio_event_monitor.c

+64 −5
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 


#include <unistd.h>

#include <stdlib.h>

#include <dirent.h>

#include <stdbool.h>

#include <stdio.h>

#include <errno.h>
@@ -280,22 +281,69 @@ static void print_event(struct iio_event_data *event) 
	printf("\n");

}



/* Enable or disable events in sysfs if the knob is available */

static void enable_events(char *dev_dir, int enable)

{

	const struct dirent *ent;

	char evdir[256];

	int ret;

	DIR *dp;



	snprintf(evdir, sizeof(evdir), FORMAT_EVENTS_DIR, dev_dir);

	evdir[sizeof(evdir)-1] = '\0';



	dp = opendir(evdir);

	if (!dp) {

		fprintf(stderr, "Enabling/disabling events: can't open %s\n",

			evdir);

		return;

	}



	while (ent = readdir(dp), ent) {

		if (iioutils_check_suffix(ent->d_name, "_en")) {

			printf("%sabling: %s\n",

			       enable ? "En" : "Dis",

			       ent->d_name);

			ret = write_sysfs_int(ent->d_name, evdir,

					      enable);

			if (ret < 0)

				fprintf(stderr, "Failed to enable/disable %s\n",

					ent->d_name);

		}

	}



	if (closedir(dp) == -1) {

		perror("Enabling/disabling channels: "

		       "Failed to close directory");

		return;

	}

}



int main(int argc, char **argv)

{

	struct iio_event_data event;

	const char *device_name;

	char *dev_dir_name = NULL;

	char *chrdev_name;

	int ret;

	int dev_num;

	int fd, event_fd;

	bool all_events = false;



	if (argc <= 1) {

		fprintf(stderr, "Usage: %s <device_name>\n", argv[0]);

	if (argc == 2) {

		device_name = argv[1];

	} else if (argc == 3) {

		device_name = argv[2];

		if (!strcmp(argv[1], "-a"))

			all_events = true;

	} else {

		fprintf(stderr,

			"Usage: iio_event_monitor [options] <device_name>\n"

			"Listen and display events from IIO devices\n"

			"  -a         Auto-activate all available events\n");

		return -1;

	}



	device_name = argv[1];



	dev_num = find_type_by_name(device_name, "iio:device");

	if (dev_num >= 0) {

		printf("Found IIO device with name %s with device number %d\n",
@@ -303,6 +351,10 @@ int main(int argc, char **argv) 
		ret = asprintf(&chrdev_name, "/dev/iio:device%d", dev_num);

		if (ret < 0)

			return -ENOMEM;

		/* Look up sysfs dir as well if we can */

		ret = asprintf(&dev_dir_name, "%siio:device%d", iio_dir, dev_num);

		if (ret < 0)

			return -ENOMEM;

	} else {

		/*

		 * If we can't find an IIO device by name assume device_name is
@@ -313,6 +365,9 @@ int main(int argc, char **argv) 
			return -ENOMEM;

	}



	if (all_events && dev_dir_name)

		enable_events(dev_dir_name, 1);



	fd = open(chrdev_name, 0);

	if (fd == -1) {

		ret = -errno;
@@ -365,6 +420,10 @@ int main(int argc, char **argv) 
		perror("Failed to close event file");



error_free_chrdev_name:

	/* Disable events after use */

	if (all_events && dev_dir_name)

		enable_events(dev_dir_name, 0);



	free(chrdev_name);



	return ret;

tools/iio/iio_utils.h

+1 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#define IIO_MAX_NAME_LENGTH 64



#define FORMAT_SCAN_ELEMENTS_DIR "%s/buffer%d"

#define FORMAT_EVENTS_DIR "%s/events"

#define FORMAT_TYPE_FILE "%s_type"



#define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))