From: Sakari Ailus Date: Mon, 10 Oct 2011 20:01:25 +0000 (-0300) Subject: [media] v4l: Implement v4l2_subdev_link_validate() X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=8227c92b69688403dee2adf5f399a49539ae5049;p=deliverable%2Flinux.git [media] v4l: Implement v4l2_subdev_link_validate() v4l2_subdev_link_validate() is the default op for validating a link. In V4L2 subdev context, it is used to call a pad op which performs the proper link check without much extra work. Signed-off-by: Sakari Ailus Acked-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index 493ffd1b1cf5..fe53177f0d3c 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -316,6 +316,18 @@ If the subdev driver intends to process video and integrate with the media framework, it must implement format related functionality using v4l2_subdev_pad_ops instead of v4l2_subdev_video_ops. +In that case, the subdev driver may set the link_validate field to provide +its own link validation function. The link validation function is called for +every link in the pipeline where both of the ends of the links are V4L2 +sub-devices. The driver is still responsible for validating the correctness +of the format configuration between sub-devices and video nodes. + +If link_validate op is not set, the default function +v4l2_subdev_link_validate_default() is used instead. This function ensures +that width, height and the media bus pixel code are equal on both source and +sink of the link. Subdev drivers are also free to use this function to +perform the checks mentioned above in addition to their own checks. + A device (bridge) driver needs to register the v4l2_subdev with the v4l2_device: diff --git a/drivers/media/video/v4l2-subdev.c b/drivers/media/video/v4l2-subdev.c index 268d80584101..db6e859b93d4 100644 --- a/drivers/media/video/v4l2-subdev.c +++ b/drivers/media/video/v4l2-subdev.c @@ -387,6 +387,70 @@ const struct v4l2_file_operations v4l2_subdev_fops = { .poll = subdev_poll, }; +#ifdef CONFIG_MEDIA_CONTROLLER +int v4l2_subdev_link_validate_default(struct v4l2_subdev *sd, + struct media_link *link, + struct v4l2_subdev_format *source_fmt, + struct v4l2_subdev_format *sink_fmt) +{ + if (source_fmt->format.width != sink_fmt->format.width + || source_fmt->format.height != sink_fmt->format.height + || source_fmt->format.code != sink_fmt->format.code) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate_default); + +static int +v4l2_subdev_link_validate_get_format(struct media_pad *pad, + struct v4l2_subdev_format *fmt) +{ + switch (media_entity_type(pad->entity)) { + case MEDIA_ENT_T_V4L2_SUBDEV: + fmt->which = V4L2_SUBDEV_FORMAT_ACTIVE; + fmt->pad = pad->index; + return v4l2_subdev_call(media_entity_to_v4l2_subdev( + pad->entity), + pad, get_fmt, NULL, fmt); + default: + WARN(1, "Driver bug! Wrong media entity type %d, entity %s\n", + media_entity_type(pad->entity), pad->entity->name); + /* Fall through */ + case MEDIA_ENT_T_DEVNODE_V4L: + return -EINVAL; + } +} + +int v4l2_subdev_link_validate(struct media_link *link) +{ + struct v4l2_subdev *sink; + struct v4l2_subdev_format sink_fmt, source_fmt; + int rval; + + rval = v4l2_subdev_link_validate_get_format( + link->source, &source_fmt); + if (rval < 0) + return 0; + + rval = v4l2_subdev_link_validate_get_format( + link->sink, &sink_fmt); + if (rval < 0) + return 0; + + sink = media_entity_to_v4l2_subdev(link->sink->entity); + + rval = v4l2_subdev_call(sink, pad, link_validate, link, + &source_fmt, &sink_fmt); + if (rval != -ENOIOCTLCMD) + return rval; + + return v4l2_subdev_link_validate_default( + sink, link, &source_fmt, &sink_fmt); +} +EXPORT_SYMBOL_GPL(v4l2_subdev_link_validate); +#endif /* CONFIG_MEDIA_CONTROLLER */ + void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops) { INIT_LIST_HEAD(&sd->list); diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h index 7e850355a6f0..1c2318b15bd2 100644 --- a/include/media/v4l2-subdev.h +++ b/include/media/v4l2-subdev.h @@ -470,6 +470,11 @@ struct v4l2_subdev_pad_ops { struct v4l2_subdev_selection *sel); int (*set_selection)(struct v4l2_subdev *sd, struct v4l2_subdev_fh *fh, struct v4l2_subdev_selection *sel); +#ifdef CONFIG_MEDIA_CONTROLLER + int (*link_validate)(struct v4l2_subdev *sd, struct media_link *link, + struct v4l2_subdev_format *source_fmt, + struct v4l2_subdev_format *sink_fmt); +#endif /* CONFIG_MEDIA_CONTROLLER */ }; struct v4l2_subdev_ops { @@ -602,6 +607,13 @@ static inline void *v4l2_get_subdev_hostdata(const struct v4l2_subdev *sd) return sd->host_priv; } +#ifdef CONFIG_MEDIA_CONTROLLER +int v4l2_subdev_link_validate_default(struct v4l2_subdev *sd, + struct media_link *link, + struct v4l2_subdev_format *source_fmt, + struct v4l2_subdev_format *sink_fmt); +int v4l2_subdev_link_validate(struct media_link *link); +#endif /* CONFIG_MEDIA_CONTROLLER */ void v4l2_subdev_init(struct v4l2_subdev *sd, const struct v4l2_subdev_ops *ops);