Hi Andy,
On Friday 02 September 2011 15:09:28 Andy Shevchenko wrote:
> 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.
Thanks for the patch. We're nearly there :-)
> 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;
> };
>
> /**
This will break binary compatibility if an application creates a struct
media_device instances itself. On the other hand applications are not supposed
to do that.
As the struct udev pointer is only used internally, what about passing it
around between functions explicitly instead ?
--
Regards,
Laurent Pinchart
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