If configured with --with-libudev, the libmediactl is built with libudev
support. It allows to get the device name in right way in the modern linux
systems.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
configure.in | 22 ++++++++++++++++
src/Makefile.am | 2 +
src/media.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/media.h | 1 +
4 files changed, 98 insertions(+), 0 deletions(-)
diff --git a/configure.in b/configure.in
index fd4c70c..983023e 100644
--- a/configure.in
+++ b/configure.in
@@ -13,6 +13,28 @@ AC_PROG_LIBTOOL
# Checks for libraries.
+AC_ARG_WITH([libudev],
+ AS_HELP_STRING([--with-libudev],
+ [Enable libudev to detect a device name]))
+
+AS_IF([test "x$with_libudev" = "xyes"],
+ [PKG_CHECK_MODULES(libudev, libudev, have_libudev=yes, have_libudev=no)],
+ [have_libudev=no])
+
+AS_IF([test "x$have_libudev" = "xyes"],
+ [
+ AC_DEFINE([HAVE_LIBUDEV], [], [Use libudev])
+ LIBUDEV_CFLAGS="$libudev_CFLAGS"
+ LIBUDEV_LIBS="$libudev_LIBS"
+ AC_SUBST(LIBUDEV_CFLAGS)
+ AC_SUBST(LIBUDEV_LIBS)
+ ],
+ [AS_IF([test "x$with_libudev" = "xyes"],
+ [AC_MSG_ERROR([libudev requested but not found])
+ ])
+])
+
+
# Kernel headers path.
AC_ARG_WITH(kernel-headers,
[AC_HELP_STRING([--with-kernel-headers=DIR],
diff --git a/src/Makefile.am b/src/Makefile.am
index 267ea83..52628d2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -5,6 +5,8 @@ mediactl_includedir=$(includedir)/mediactl
mediactl_include_HEADERS = media.h subdev.h
bin_PROGRAMS = media-ctl
+media_ctl_CFLAGS = $(LIBUDEV_CFLAGS)
+media_ctl_LDFLAGS = $(LIBUDEV_LIBS)
media_ctl_SOURCES = main.c options.c options.h tools.h
media_ctl_LDADD = libmediactl.la libv4l2subdev.la
diff --git a/src/media.c b/src/media.c
index 5d3ff7c..dae649a 100644
--- a/src/media.c
+++ b/src/media.c
@@ -17,6 +17,8 @@
* with this program; if not, write to the Free Software Foundation, Inc.,
*/
+#include "config.h"
+
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
@@ -245,6 +247,64 @@ static int media_enum_links(struct media_device *media)
return ret;
}
+#ifdef HAVE_LIBUDEV
+
+#include <libudev.h>
+
+static inline int media_udev_open(struct media_device *media)
+{
+ media->priv = udev_new();
+ if (media->priv == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+static inline void media_udev_close(struct media_device *media)
+{
+ udev_unref(media->priv);
+}
+
+static int media_get_devname_udev(struct media_device *media,
+ struct media_entity *entity)
+{
+ int ret = -ENODEV;
+ struct udev *udev = media->priv;
+ dev_t devnum;
+ struct udev_device *device;
+ const char *p;
+
+ if (udev == NULL)
+ return -EINVAL;
+
+ devnum = makedev(entity->info.v4l.major, entity->info.v4l.minor);
+ printf("looking up device: %u:%u\n", major(devnum), minor(devnum));
+ device = udev_device_new_from_devnum(udev, 'c', devnum);
+ if (device) {
+ p = udev_device_get_devnode(device);
+ if (p)
+ snprintf(entity->devname, sizeof(entity->devname), "%s", p);
+ ret = 0;
+ }
+
+ udev_device_unref(device);
+
+ return ret;
+}
+
+#else /* HAVE_LIBUDEV */
+
+static inline int media_udev_open(struct media_device *media) { return 0; }
+
+static inline void media_udev_close(struct media_device *media) { }
+
+static inline int media_get_devname_udev(struct media_device *media,
+ struct media_entity *entity)
+{
+ return -ENOTSUP;
+}
+
+#endif /* HAVE_LIBUDEV */
+
static int media_get_devname_sysfs(struct media_entity *entity)
{
struct stat devstat;
@@ -324,6 +384,11 @@ static int media_enum_entities(struct media_device *media)
media_entity_type(entity) != MEDIA_ENT_T_V4L2_SUBDEV)
continue;
+ /* Try to get the device name via udev */
+ if (!media_get_devname_udev(media, entity))
+ continue;
+
+ /* Fall back to get the device name via sysfs */
media_get_devname_sysfs(entity);
}
@@ -351,6 +416,13 @@ struct media_device *media_open(const char *name, int verbose)
return NULL;
}
+ ret = media_udev_open(media);
+ if (ret < 0) {
+ printf("%s: Can't get udev context\n", __func__);
+ media_close(media);
+ return NULL;
+ }
+
if (verbose)
printf("Enumerating entities\n");
@@ -395,6 +467,7 @@ void media_close(struct media_device *media)
}
free(media->entities);
+ media_udev_close(media);
free(media);
}
diff --git a/src/media.h b/src/media.h
index b91a2ac..4201451 100644
--- a/src/media.h
+++ b/src/media.h
@@ -54,6 +54,7 @@ struct media_device {
struct media_entity *entities;
unsigned int entities_count;
__u32 padding[6];
+ void *priv;
};
/**
--
1.7.5.4
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
