Hi Jacek,
On Wed, Oct 12, 2016 at 04:35:16PM +0200, Jacek Anaszewski wrote:
> Make struct v4l2_subdev capable of aggregating v4l2-ctrl-bindings -
> media device configuration entries. Added are also functions for
> validating support for the control on given media entity and checking
> whether a v4l2-ctrl-binding has been defined for a media entity.
I still don't think this belongs here.
I think I told you about the generic pipeline configuration library I worked
on years ago; unfortunately it was left on prototype stage. Still, what I
realised was that something very similar is needed in that library ---
associating information to the representation of the media entities (or the
V4L2 sub-devices) in user space that has got nothing to do with the devices
themselves.
We could have e.g. a list of key--value pairs where the key is a pointer
provided by the user (i.e. application, another library) that could be
associated with the value. That would avoid having explicit information on
that in the struct media_entity itself.
An quicker alternative would be to manage a list of controls e.g. in the
plugin itself and store the media entity where they're implemented in that
list, with the control value.
Cc Laurent as well.
>
> Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
> Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> ---
> utils/media-ctl/libv4l2subdev.c | 32 ++++++++++++++++++++++++++++++++
> utils/media-ctl/v4l2subdev.h | 19 +++++++++++++++++++
> 2 files changed, 51 insertions(+)
>
> diff --git a/utils/media-ctl/libv4l2subdev.c b/utils/media-ctl/libv4l2subdev.c
> index c3439d7..4f8ee7f 100644
> --- a/utils/media-ctl/libv4l2subdev.c
> +++ b/utils/media-ctl/libv4l2subdev.c
> @@ -50,7 +50,15 @@ int v4l2_subdev_create(struct media_entity *entity)
>
> entity->sd->fd = -1;
>
> + entity->sd->v4l2_ctrl_bindings = malloc(sizeof(__u32));
> + if (entity->sd->v4l2_ctrl_bindings == NULL)
> + goto err_v4l2_ctrl_bindings_alloc;
> +
> return 0;
> +
> +err_v4l2_ctrl_bindings_alloc:
> + free(entity->sd);
> + return -ENOMEM;
> }
>
> int v4l2_subdev_create_opened(struct media_entity *entity, int fd)
> @@ -102,6 +110,7 @@ void v4l2_subdev_close(struct media_entity *entity)
> if (entity->sd->fd_owner)
> close(entity->sd->fd);
>
> + free(entity->sd->v4l2_ctrl_bindings);
> free(entity->sd);
> }
>
> @@ -884,3 +893,26 @@ const enum v4l2_mbus_pixelcode *v4l2_subdev_pixelcode_list(unsigned int *length)
>
> return mbus_codes;
> }
> +
> +int v4l2_subdev_supports_v4l2_ctrl(struct media_device *media,
> + struct media_entity *entity,
> + __u32 ctrl_id)
> +{
> + struct v4l2_queryctrl queryctrl = {};
> + int ret;
> +
> + ret = v4l2_subdev_open(entity);
> + if (ret < 0)
> + return ret;
> +
> + queryctrl.id = ctrl_id;
> +
> + ret = ioctl(entity->sd->fd, VIDIOC_QUERYCTRL, &queryctrl);
> + if (ret < 0)
> + return ret;
> +
> + media_dbg(media, "Validated control \"%s\" (0x%8.8x) on entity %s\n",
> + queryctrl.name, queryctrl.id, entity->info.name);
> +
> + return 0;
> +}
> diff --git a/utils/media-ctl/v4l2subdev.h b/utils/media-ctl/v4l2subdev.h
> index 011fab1..4dee6b1 100644
> --- a/utils/media-ctl/v4l2subdev.h
> +++ b/utils/media-ctl/v4l2subdev.h
> @@ -26,10 +26,14 @@
>
> struct media_device;
> struct media_entity;
> +struct media_device;
>
> struct v4l2_subdev {
> int fd;
> unsigned int fd_owner:1;
> +
> + __u32 *v4l2_ctrl_bindings;
> + unsigned int num_v4l2_ctrl_bindings;
> };
>
> /**
> @@ -314,4 +318,19 @@ enum v4l2_field v4l2_subdev_string_to_field(const char *string);
> const enum v4l2_mbus_pixelcode *v4l2_subdev_pixelcode_list(
> unsigned int *length);
>
> +/**
> + * @brief Check if sub-device supports given v4l2 control
> + * @param media - media device.
> + * @param entity - media entity.
> + * @param ctrl_id - id of the v4l2 control to check.
> + *
> + * Verify if the sub-device associated with given media entity
> + * supports v4l2-control with given ctrl_id.
> + *
> + * @return 1 if the control is supported, 0 otherwise.
> + */
> +int v4l2_subdev_supports_v4l2_ctrl(struct media_device *device,
> + struct media_entity *entity,
> + __u32 ctrl_id);
> +
> #endif
--
Kind regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx
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