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 | 105 +++++++++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 127 insertions(+), 2 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..657b6c4 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 +247,71 @@ static int media_enum_links(struct media_device *media)
return ret;
}
+struct media_private {
+ struct media_device *media;
+ int verbose;
+ void *priv;
+};
+
+#ifdef HAVE_LIBUDEV
+
+#include <libudev.h>
+
+static inline int media_udev_open(struct media_private *priv)
+{
+ priv->priv = udev_new();
+ if (priv->priv == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+static inline void media_udev_close(struct media_private *priv)
+{
+ udev_unref(priv->priv);
+}
+
+static int media_get_devname_udev(struct media_private *priv,
+ struct media_entity *entity)
+{
+ struct udev *udev = priv->priv;
+ dev_t devnum;
+ struct udev_device *device;
+ const char *p;
+ int ret = -ENODEV;
+
+ if (udev == NULL)
+ return -EINVAL;
+
+ devnum = makedev(entity->info.v4l.major, entity->info.v4l.minor);
+ if (priv->verbose)
+ 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_private *priv) { return 0; }
+
+static inline void media_udev_close(struct media_private *priv) { }
+
+static inline int media_get_devname_udev(struct media_private *priv,
+ struct media_entity *entity)
+{
+ return -ENOTSUP;
+}
+
+#endif /* HAVE_LIBUDEV */
+
static int media_get_devname_sysfs(struct media_entity *entity)
{
struct stat devstat;
@@ -281,8 +348,9 @@ static int media_get_devname_sysfs(struct media_entity *entity)
return 0;
}
-static int media_enum_entities(struct media_device *media)
+static int media_enum_entities(struct media_private *priv)
{
+ struct media_device *media = priv->media;
struct media_entity *entity;
unsigned int size;
__u32 id;
@@ -324,6 +392,11 @@ 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(priv, entity))
+ continue;
+
+ /* Fall back to get the device name via sysfs */
media_get_devname_sysfs(entity);
}
@@ -333,6 +406,7 @@ static int media_enum_entities(struct media_device *media)
struct media_device *media_open(const char *name, int verbose)
{
struct media_device *media;
+ struct media_private *priv;
int ret;
media = malloc(sizeof(*media));
@@ -351,13 +425,39 @@ struct media_device *media_open(const char *name, int verbose)
return NULL;
}
+ priv = malloc(sizeof(*priv));
+ if (priv == NULL) {
+ printf("%s: unable to allocate memory\n", __func__);
+ media_close(media);
+ return NULL;
+ }
+ memset(priv, 0, sizeof(*priv));
+
+ /* Fill the private structure */
+ priv->media = media;
+ priv->verbose = verbose;
+
+ ret = media_udev_open(priv);
+ if (ret < 0) {
+ printf("%s: Can't get udev context\n", __func__);
+ free(priv);
+ media_close(media);
+ return NULL;
+ }
+
if (verbose)
printf("Enumerating entities\n");
- ret = media_enum_entities(media);
+ ret = media_enum_entities(priv);
+
+ /* We should close the udev independently of return value of
+ * media_enum_entities. */
+ media_udev_close(priv);
+
if (ret < 0) {
printf("%s: Unable to enumerate entities for device %s (%s)\n",
__func__, name, strerror(-ret));
+ free(priv);
media_close(media);
return NULL;
}
@@ -371,6 +471,7 @@ struct media_device *media_open(const char *name, int verbose)
if (ret < 0) {
printf("%s: Unable to enumerate pads and linksfor device %s\n",
__func__, name);
+ free(priv);
media_close(media);
return NULL;
}
--
1.7.5.4
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