Hi Jacek,
On Mon, Nov 28, 2016 at 10:32:43PM +0100, Jacek Anaszewski wrote:
> Hi Sakari,
>
> On 11/24/2016 03:23 PM, Sakari Ailus wrote:
> >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.
s/value/id/
>
> We are not interested in media entity -> control value relation but
> but media entity -> control id. The value is an arbitrary choice of
> userspace. Binding's task is to route the ctrl ioctl to a desired
> pipeline entity if more than one supports same control.
Correct. But even that's more efficient if you don't need to iterate over
all the entities.
>
> Effectively we'd need a list of controls as a keys and entities
> as values. The list should be allocated dynamically as it would
> make no sense to keep keys for all v4l2 controls if only few bindings
> are defined.
>
> Best regards,
> Jacek Anaszewski
>
> >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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