| Message ID | 20220302220304.1327896-3-djrscally@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Introduce ancillary links | expand |
Hi ! Thanks for the patch ! On 02/03/2022 23:03, Daniel Scally wrote: > To describe in the kernel the connection between devices and their > supporting peripherals (for example, a camera sensor and the vcm > driving the focusing lens for it), add a new type of media link > to introduce the concept of these ancillary links. > > Add some elements to the uAPI documentation to explain the new link > type, their purpose and some aspects of their current implementation. > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Signed-off-by: Daniel Scally <djrscally@gmail.com> Reviewed-by: Jean-Michel Hautbois <jeanmichel.hautbois@ideasonboard.com> > --- > > Changes since v1: > > - None > > changes since the rfc: > > - Split out into its own patch (mostly so it can be followed by patch > #3, which corrects some media-core code that is otherwise broken by the > new links) > > .../media/mediactl/media-controller-model.rst | 6 ++++++ > .../media/mediactl/media-types.rst | 17 ++++++++++++----- > include/uapi/linux/media.h | 1 + > 3 files changed, 19 insertions(+), 5 deletions(-) > > diff --git a/Documentation/userspace-api/media/mediactl/media-controller-model.rst b/Documentation/userspace-api/media/mediactl/media-controller-model.rst > index 222cb99debb5..78bfdfb2a322 100644 > --- a/Documentation/userspace-api/media/mediactl/media-controller-model.rst > +++ b/Documentation/userspace-api/media/mediactl/media-controller-model.rst > @@ -33,3 +33,9 @@ are: > > - An **interface link** is a point-to-point bidirectional control > connection between a Linux Kernel interface and an entity. > + > +- An **ancillary link** is a point-to-point connection denoting that two > + entities form a single logical unit. For example this could represent the > + fact that a particular camera sensor and lens controller form a single > + physical module, meaning this lens controller drives the lens for this > + camera sensor. > \ No newline at end of file > diff --git a/Documentation/userspace-api/media/mediactl/media-types.rst b/Documentation/userspace-api/media/mediactl/media-types.rst > index 0a26397bd01d..60747251d409 100644 > --- a/Documentation/userspace-api/media/mediactl/media-types.rst > +++ b/Documentation/userspace-api/media/mediactl/media-types.rst > @@ -412,14 +412,21 @@ must be set for every pad. > is set by drivers and is read-only for applications. > > * - ``MEDIA_LNK_FL_LINK_TYPE`` > - - This is a bitmask that defines the type of the link. Currently, > - two types of links are supported: > + - This is a bitmask that defines the type of the link. The following > + link types are currently supported: > > .. _MEDIA-LNK-FL-DATA-LINK: > > - ``MEDIA_LNK_FL_DATA_LINK`` if the link is between two pads > + ``MEDIA_LNK_FL_DATA_LINK`` for links that represent a data connection > + between two pads. > > .. _MEDIA-LNK-FL-INTERFACE-LINK: > > - ``MEDIA_LNK_FL_INTERFACE_LINK`` if the link is between an > - interface and an entity > + ``MEDIA_LNK_FL_INTERFACE_LINK`` for links that associate an entity to its > + interface. > + > + .. _MEDIA-LNK-FL-ANCILLARY-LINK: > + > + ``MEDIA_LNK_FL_ANCILLARY_LINK`` for links that represent a physical > + relationship between two entities. The link may or may not be ummutable, so > + applications must not assume either case. > \ No newline at end of file > diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h > index 200fa8462b90..afbae7213d35 100644 > --- a/include/uapi/linux/media.h > +++ b/include/uapi/linux/media.h > @@ -226,6 +226,7 @@ struct media_pad_desc { > #define MEDIA_LNK_FL_LINK_TYPE (0xf << 28) > # define MEDIA_LNK_FL_DATA_LINK (0 << 28) > # define MEDIA_LNK_FL_INTERFACE_LINK (1 << 28) > +# define MEDIA_LNK_FL_ANCILLARY_LINK (2 << 28) > > struct media_link_desc { > struct media_pad_desc source;
diff --git a/Documentation/userspace-api/media/mediactl/media-controller-model.rst b/Documentation/userspace-api/media/mediactl/media-controller-model.rst index 222cb99debb5..78bfdfb2a322 100644 --- a/Documentation/userspace-api/media/mediactl/media-controller-model.rst +++ b/Documentation/userspace-api/media/mediactl/media-controller-model.rst @@ -33,3 +33,9 @@ are: - An **interface link** is a point-to-point bidirectional control connection between a Linux Kernel interface and an entity. + +- An **ancillary link** is a point-to-point connection denoting that two + entities form a single logical unit. For example this could represent the + fact that a particular camera sensor and lens controller form a single + physical module, meaning this lens controller drives the lens for this + camera sensor. \ No newline at end of file diff --git a/Documentation/userspace-api/media/mediactl/media-types.rst b/Documentation/userspace-api/media/mediactl/media-types.rst index 0a26397bd01d..60747251d409 100644 --- a/Documentation/userspace-api/media/mediactl/media-types.rst +++ b/Documentation/userspace-api/media/mediactl/media-types.rst @@ -412,14 +412,21 @@ must be set for every pad. is set by drivers and is read-only for applications. * - ``MEDIA_LNK_FL_LINK_TYPE`` - - This is a bitmask that defines the type of the link. Currently, - two types of links are supported: + - This is a bitmask that defines the type of the link. The following + link types are currently supported: .. _MEDIA-LNK-FL-DATA-LINK: - ``MEDIA_LNK_FL_DATA_LINK`` if the link is between two pads + ``MEDIA_LNK_FL_DATA_LINK`` for links that represent a data connection + between two pads. .. _MEDIA-LNK-FL-INTERFACE-LINK: - ``MEDIA_LNK_FL_INTERFACE_LINK`` if the link is between an - interface and an entity + ``MEDIA_LNK_FL_INTERFACE_LINK`` for links that associate an entity to its + interface. + + .. _MEDIA-LNK-FL-ANCILLARY-LINK: + + ``MEDIA_LNK_FL_ANCILLARY_LINK`` for links that represent a physical + relationship between two entities. The link may or may not be ummutable, so + applications must not assume either case. \ No newline at end of file diff --git a/include/uapi/linux/media.h b/include/uapi/linux/media.h index 200fa8462b90..afbae7213d35 100644 --- a/include/uapi/linux/media.h +++ b/include/uapi/linux/media.h @@ -226,6 +226,7 @@ struct media_pad_desc { #define MEDIA_LNK_FL_LINK_TYPE (0xf << 28) # define MEDIA_LNK_FL_DATA_LINK (0 << 28) # define MEDIA_LNK_FL_INTERFACE_LINK (1 << 28) +# define MEDIA_LNK_FL_ANCILLARY_LINK (2 << 28) struct media_link_desc { struct media_pad_desc source;