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 <[email protected]> Acked-by: Kyungmin Park <[email protected]> --- 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 a294ada..6d3e691 100644 --- a/utils/media-ctl/libmediactl.c +++ b/utils/media-ctl/libmediactl.c @@ -719,6 +719,44 @@ struct media_device *media_device_new(const char *devnode) return media; } +struct media_device *media_device_new_by_entity_devname(char *entity_devname) +{ + struct media_device *media; + char media_devname[32]; + struct media_entity *entity; + int i, ret; + + /* 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; @@ -758,6 +796,43 @@ 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; + + 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"); + + /* 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); +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. * -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
