On 11/09/2018 10:52 PM, Ezequiel Garcia wrote:
> This tool allows to find a device by driver name,
> this is useful for scripts to be written in a generic way.
Why not add support for this to v4l2-sysfs-path? And improve it at the same
time (swradio devices do not show up when I run v4l2-sysfs-path, I also suspect
v4l-touch devices aren't recognized. Ditto for media devices.
>
> Usage:
>
> v4l2-get-device -d uvcvideo -c V4L2_CAP_VIDEO_CAPTURE
> /dev/video0
> /dev/video2
>
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>
> ---
> configure.ac | 1 +
> utils/Makefile.am | 1 +
> utils/v4l2-get-device/.gitignore | 1 +
> utils/v4l2-get-device/Makefile.am | 4 +
> utils/v4l2-get-device/v4l2-get-device.c | 147 ++++++++++++++++++++++++
> v4l-utils.spec.in | 1 +
> 6 files changed, 155 insertions(+)
> create mode 100644 utils/v4l2-get-device/.gitignore
> create mode 100644 utils/v4l2-get-device/Makefile.am
> create mode 100644 utils/v4l2-get-device/v4l2-get-device.c
>
> diff --git a/configure.ac b/configure.ac
> index 5cc34c248fbf..918cb59704b9 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -31,6 +31,7 @@ AC_CONFIG_FILES([Makefile
> utils/v4l2-compliance/Makefile
> utils/v4l2-ctl/Makefile
> utils/v4l2-dbg/Makefile
> + utils/v4l2-get-device/Makefile
> utils/v4l2-sysfs-path/Makefile
> utils/qv4l2/Makefile
> utils/cec-ctl/Makefile
> diff --git a/utils/Makefile.am b/utils/Makefile.am
> index 2d5070288c13..2b2b27107d13 100644
> --- a/utils/Makefile.am
> +++ b/utils/Makefile.am
> @@ -9,6 +9,7 @@ SUBDIRS = \
> v4l2-compliance \
> v4l2-ctl \
> v4l2-dbg \
> + v4l2-get-device \
> v4l2-sysfs-path \
> cec-ctl \
> cec-compliance \
> diff --git a/utils/v4l2-get-device/.gitignore b/utils/v4l2-get-device/.gitignore
> new file mode 100644
> index 000000000000..b222144c9f4e
> --- /dev/null
> +++ b/utils/v4l2-get-device/.gitignore
> @@ -0,0 +1 @@
> +v4l2-get-device
> diff --git a/utils/v4l2-get-device/Makefile.am b/utils/v4l2-get-device/Makefile.am
> new file mode 100644
> index 000000000000..2e5a6e0ba32f
> --- /dev/null
> +++ b/utils/v4l2-get-device/Makefile.am
> @@ -0,0 +1,4 @@
> +bin_PROGRAMS = v4l2-get-device
> +v4l2_get_device_SOURCES = v4l2-get-device.c
> +v4l2_get_device_LDADD = ../libmedia_dev/libmedia_dev.la
> +v4l2_get_device_LDFLAGS = $(ARGP_LIBS)
> diff --git a/utils/v4l2-get-device/v4l2-get-device.c b/utils/v4l2-get-device/v4l2-get-device.c
> new file mode 100644
> index 000000000000..f9cc323b7057
> --- /dev/null
> +++ b/utils/v4l2-get-device/v4l2-get-device.c
> @@ -0,0 +1,147 @@
> +/*
> + * Copyright © 2018 Collabora, Ltd.
> + *
> + * Based on v4l2-sysfs-path by Mauro Carvalho Chehab:
> + *
> + * Copyright © 2011 Red Hat, Inc.
> + *
> + * Permission to use, copy, modify, distribute, and sell this software
> + * and its documentation for any purpose is hereby granted without
> + * fee, provided that the above copyright notice appear in all copies
> + * and that both that copyright notice and this permission notice
> + * appear in supporting documentation, and that the name of Red Hat
> + * not be used in advertising or publicity pertaining to distribution
> + * of the software without specific, written prior permission. Red
> + * Hat makes no representations about the suitability of this software
> + * for any purpose. It is provided "as is" without express or implied
> + * warranty.
> + *
> + * THE AUTHORS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
> + * NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
> + * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
> + * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
> + * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
> + *
> + */
> +
> +#include <argp.h>
> +#include <config.h>
> +#include <fcntl.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <sys/ioctl.h>
> +#include <sys/unistd.h>
> +
> +#include <linux/videodev2.h>
> +
> +#include "../libmedia_dev/get_media_devices.h"
> +
> +const char *argp_program_version = "v4l2-get-device " V4L_UTILS_VERSION;
> +const char *argp_program_bug_address = "Ezequiel Garcia <ezequiel@xxxxxxxxxxxxx>";
> +
> +struct args {
> + const char *driver;
> + unsigned int device_caps;
> +};
> +
> +static const struct argp_option options[] = {
> + {"driver", 'd', "DRIVER", 0, "device driver name", 0},
> + {"v4l2-device-caps", 'c', "CAPS", 0, "v4l2 device capabilities", 0},
I'd like a bus-info option as well, if possible.
> + { 0 }
> +};
> +
> +static unsigned int parse_capabilities(const char *arg)
> +{
> + char *s, *str = strdup(arg);
> + unsigned int caps = 0;
> +
> + s = strtok (str,",");
> + while (s != NULL) {
> + if (!strcmp(s, "V4L2_CAP_VIDEO_CAPTURE"))
> + caps |= V4L2_CAP_VIDEO_CAPTURE;
> + else if (!strcmp(s, "V4L2_CAP_VIDEO_OUTPUT"))
> + caps |= V4L2_CAP_VIDEO_OUTPUT;
> + else if (!strcmp(s, "V4L2_CAP_VIDEO_OVERLAY"))
> + caps |= V4L2_CAP_VIDEO_OVERLAY;
> + else if (!strcmp(s, "V4L2_CAP_VBI_CAPTURE"))
> + caps |= V4L2_CAP_VBI_CAPTURE;
> + else if (!strcmp(s, "V4L2_CAP_VBI_OUTPUT"))
> + caps |= V4L2_CAP_VBI_OUTPUT;
Let's support all CAPS here. I'd also drop the V4L2_CAP_ prefix (or make it optional)
and make the strcmp case-insensitive to ease typing.
> + s = strtok (NULL, ",");
> + }
> + free(str);
> + return caps;
> +}
> +
> +static error_t parse_opt(int k, char *arg, struct argp_state *state)
> +{
> + struct args *args = state->input;
> +
> + switch (k) {
> + case 'd':
> + args->driver = arg;
> + break;
> + case 'c':
> + args->device_caps = parse_capabilities(arg);
> + break;
> + default:
> + return ARGP_ERR_UNKNOWN;
> + }
> + return 0;
> +}
> +
> +static struct argp argp = {
> + .options = options,
> + .parser = parse_opt,
> +};
> +
> +int main(int argc, char *argv[])
> +{
> + const char *vid;
> + struct args args;
> + void *md;
> +
> + args.driver = NULL;
> + args.device_caps = 0;
> + argp_parse(&argp, argc, argv, 0, 0, &args);
> +
> + md = discover_media_devices();
I never really liked this. My main problem is that it doesn't know about media devices.
In my view it should look for media devices first, query them and get all the device
nodes referenced in the topology, and then fall back to the old method to discover
any remaining device nodes for drivers that do not create a media device.
You need media device support anyway since you also want to be able to query the media
device for a specific driver and find the device node for a specific entity.
> +
> + vid = NULL;
> + do {
> + struct v4l2_capability cap;
> + char devnode[64];
> + int ret;
> + int fd;
> +
> + vid = get_associated_device(md, vid, MEDIA_V4L_VIDEO,
> + NULL, NONE);
> + if (!vid)
> + break;
> + snprintf(devnode, 64, "/dev/%s", vid);
> + fd = open(devnode, O_RDWR);
> + if (fd < 0)
> + continue;
> +
> + memset(&cap, 0, sizeof cap);
> + ret = ioctl(fd, VIDIOC_QUERYCAP, &cap);
> + if (ret) {
> + close(fd);
> + continue;
> + }
> + close(fd);
> +
> + if (strncmp(args.driver, (char *)cap.driver, sizeof(cap.driver)))
> + continue;
> + if (args.device_caps && (args.device_caps & cap.device_caps) != args.device_caps)
> + continue;
> + fprintf(stdout, "%s\n", devnode);
> + } while (vid);
> + free_media_devices(md);
> + return 0;
> +}
> diff --git a/v4l-utils.spec.in b/v4l-utils.spec.in
> index 67bdca57ae92..ab15286b039b 100644
> --- a/v4l-utils.spec.in
> +++ b/v4l-utils.spec.in
> @@ -159,6 +159,7 @@ gtk-update-icon-cache %{_datadir}/icons/hicolor &>/dev/null || :
> %{_bindir}/ivtv-ctl
> %{_bindir}/v4l2-ctl
> %{_bindir}/v4l2-sysfs-path
> +%{_bindir}/v4l2-get-device
> %{_mandir}/man1/ir-keytable.1*
> %{_mandir}/man1/ir-ctl.1*
>
>
Regards,
Hans
