Hi Jacek,
On Mon, Jan 18, 2016 at 05:17:31PM +0100, Jacek Anaszewski wrote:
> Add helper functions that allow for easy instantiation of media_device
> object basing on whether the media device contains video device with
> given node name.
>
> Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> utils/media-ctl/libmediactl.c | 75 +++++++++++++++++++++++++++++++++++++++++
> utils/media-ctl/mediactl.h | 30 +++++++++++++++++
> 2 files changed, 105 insertions(+)
>
> diff --git a/utils/media-ctl/libmediactl.c b/utils/media-ctl/libmediactl.c
> index 0be1845..3a45ecc 100644
> --- a/utils/media-ctl/libmediactl.c
> +++ b/utils/media-ctl/libmediactl.c
> @@ -734,6 +734,44 @@ struct media_device *media_device_new(const char *devnode)
> return media;
> }
>
> +struct media_device *media_device_new_by_entity_devname(char *entity_devname)
const char *...
> +{
> + struct media_device *media;
> + char media_devname[32];
> + struct media_entity *entity;
> + int i, ret;
unsigned int i
> +
> + /* query all available media devices */
> + for (i = 0;; ++i) {
> + sprintf(media_devname, "/dev/media%d", i);
> +
> + media = media_device_new(media_devname);
> + if (media == NULL)
> + return NULL;
> +
> + ret = media_device_enumerate(media);
> + if (ret < 0) {
> + media_dbg(media, "Failed to enumerate %s (%d)\n",
> + media_devname, ret);
> + goto err_dev_enum;
> + }
> +
> + /* Check if the media device contains entity with entity_devname */
> + entity = media_get_entity_by_devname(media, entity_devname,
> + strlen(entity_devname));
> + if (entity)
> + return media;
> +
> + if (media)
> + media_device_unref(media);
> + }
> +
> +err_dev_enum:
> + if (media)
> + media_device_unref(media);
> + return NULL;
> +}
> +
> struct media_device *media_device_new_emulated(struct media_device_info *info)
> {
> struct media_device *media;
> @@ -773,6 +811,43 @@ void media_device_unref(struct media_device *media)
> free(media);
> }
>
> +int media_get_devname_by_fd(int fd, char *node_name)
> +{
> + struct udev *udev;
> + struct media_entity tmp_entity;
> + struct stat stat;
> + int ret;
> +
> + if (node_name == NULL)
> + return -EINVAL;
> +
> + ret = fstat(fd, &stat);
> + if (ret < 0)
> + return -EINVAL;
return -errno
> +
> + tmp_entity.info.v4l.major = MAJOR(stat.st_rdev);
> + tmp_entity.info.v4l.minor = MINOR(stat.st_rdev);
> +
> + ret = media_udev_open(&udev);
> + if (ret < 0)
> + printf("Can't get udev context\n");
If this fails, you shouldn't call media_get_devname_udev() below, nor
media_udev_close().
> +
> + /* Try to get the device name via udev */
> + ret = media_get_devname_udev(udev, &tmp_entity);
> + if (!ret)
> + goto out;
> +
> + ret = media_get_devname_sysfs(&tmp_entity);
> + if (ret < 0)
> + goto err_get_devname;
> +
> +out:
> + strcpy(node_name, tmp_entity.devname);
You have to ensure node_name is long enough.
> +err_get_devname:
> + media_udev_close(udev);
> + return ret;
> +}
> +
> int media_device_add_entity(struct media_device *media,
> const struct media_entity_desc *desc,
> const char *devnode)
> diff --git a/utils/media-ctl/mediactl.h b/utils/media-ctl/mediactl.h
> index 9db40a8..1d62191 100644
> --- a/utils/media-ctl/mediactl.h
> +++ b/utils/media-ctl/mediactl.h
> @@ -76,6 +76,23 @@ struct media_device *media_device_new(const char *devnode);
> struct media_device *media_device_new_emulated(struct media_device_info *info);
>
> /**
> + * @brief Create a new media device if it comprises entity with given devname
> + * @param entity_devname - device node name of the entity to be matched.
> + *
> + * Query all media devices available in the system to find the one comprising
> + * the entity with given devname. If the media device is matched then its
> + * instance is created and initialized with enumerated entities and links.
> + * The returned device can be accessed.
> + *
> + * Media devices are reference-counted, see media_device_ref() and
> + * media_device_unref() for more information.
> + *
> + * @return A pointer to the new media device or NULL if video_devname cannot
> + * be matched or memory cannot be allocated.
> + */
> +struct media_device *media_device_new_by_entity_devname(char *entity_devname);
> +
> +/**
> * @brief Take a reference to the device.
> * @param media - device instance.
> *
> @@ -240,6 +257,19 @@ const char *media_entity_get_devname(struct media_entity *entity);
> */
> const char *media_entity_get_name(struct media_entity *entity);
>
> +/**
> + * @brief Get the device node name by its file descriptor
> + * @param fd - file descriptor of a device.
> + * @param node_name - output device node name string.
> + *
> + * This function returns the full path and name to the device node corresponding
> + * to the given file descriptor.
> + *
> + * @return 0 on success, or a negative error code on failure.
> + */
> +int media_get_devname_by_fd(int fd, char *node_name);
> +
> +/**
> * @brief Get the type of an entity.
> * @param entity - the entity.
> *
--
Kind regards,
Sakari Ailus
sakari.ailus@xxxxxxxxxxxxxxx
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