On Thu, 2021-03-04 at 16:42 +0100, Linus Walleij wrote:
> 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.
>
> I didn't add a command line option for this, to me it
> seems pretty intuitive and mostly what you want the tool
> to do for you.
>
> Cc: Bastien Nocera <hadess@xxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
If I'm not mistaken, "-a" does that for the iio_generic_buffer tool.
Maybe moving enable_disable_all_channels() to a common location and
using that would cut down on the duplicated code?
> ---
> Bastien: added you on CC FYI because I suppose maybe
> iio-sensor-proxy isn't yet doing this and one day people
> will wonder why their events aren't arriving.
> ---
> tools/iio/iio_event_monitor.c | 51
> +++++++++++++++++++++++++++++++++++
> tools/iio/iio_utils.h | 1 +
> 2 files changed, 52 insertions(+)
>
> diff --git a/tools/iio/iio_event_monitor.c
> b/tools/iio/iio_event_monitor.c
> index bb03859db89d..27778fe28f82 100644
> --- a/tools/iio/iio_event_monitor.c
> +++ b/tools/iio/iio_event_monitor.c
> @@ -14,6 +14,7 @@
>
> #include <unistd.h>
> #include <stdlib.h>
> +#include <dirent.h>
> #include <stdbool.h>
> #include <stdio.h>
> #include <errno.h>
> @@ -280,10 +281,49 @@ 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;
> @@ -303,6 +343,10 @@ 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 +357,9 @@ int main(int argc, char **argv)
> return -ENOMEM;
> }
>
> + if (dev_dir_name)
> + enable_events(dev_dir_name, 1);
> +
> fd = open(chrdev_name, 0);
> if (fd == -1) {
> ret = -errno;
> @@ -365,6 +412,10 @@ int main(int argc, char **argv)
> perror("Failed to close event file");
>
> error_free_chrdev_name:
> + /* Disable events after use */
> + if (dev_dir_name)
> + enable_events(dev_dir_name, 0);
> +
> free(chrdev_name);
>
> return ret;
> diff --git a/tools/iio/iio_utils.h b/tools/iio/iio_utils.h
> index 74bde4fde2c8..c01695049739 100644
> --- a/tools/iio/iio_utils.h
> +++ b/tools/iio/iio_utils.h
> @@ -13,6 +13,7 @@
> #define IIO_MAX_NAME_LENGTH 64
>
> #define FORMAT_SCAN_ELEMENTS_DIR "%s/scan_elements"
> +#define FORMAT_EVENTS_DIR "%s/events"
> #define FORMAT_TYPE_FILE "%s_type"
>
> #define ARRAY_SIZE(arr) (sizeof(arr) / sizeof(arr[0]))
