On Fri, 19 Mar 2021 14:53:01 +0100
Linus Walleij <linus.walleij@xxxxxxxxxx> 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, 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@xxxxxxxxxx>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
Hi Linus
This crossed with some changes in the header reflecting the
new buffer structure (example is not using the compatible
old form which is still there). Added a bit of fuzz but
nothing that looks significant.
Applied to the togreg branch of iio.git and pushed out as testing,
though I've no idea if the autobuilders even build tools/*
Thanks,
Jonathan
> ---
> ChangeLog v1->v2:
> - Activate all events in response to -a being passed
> on the command line
> - Update help text
> ---
> tools/iio/iio_event_monitor.c | 69 ++++++++++++++++++++++++++++++++---
> tools/iio/iio_utils.h | 1 +
> 2 files changed, 65 insertions(+), 5 deletions(-)
>
> diff --git a/tools/iio/iio_event_monitor.c b/tools/iio/iio_event_monitor.c
> index bb03859db89d..0076437f6e3f 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>
> @@ -280,22 +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;
> -
> - if (argc <= 1) {
> - fprintf(stderr, "Usage: %s <device_name>\n", argv[0]);
> + bool all_events = false;
> +
> + 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;
> 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]))
