| Message ID | 20211130141536.891878-28-tomi.valkeinen@ideasonboard.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | v4l: subdev internal routing and streams | expand |
Quoting Tomi Valkeinen (2021-11-30 14:15:25) > From: Jacopo Mondi <jacopo+renesas@jmondi.org> > > Add documentation for VIDIOC_SUBDEV_G/S_ROUTING ioctl and add > description of multiplexed media pads and internal routing to the > V4L2-subdev documentation section. > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> > Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> > --- > .../userspace-api/media/v4l/dev-subdev.rst | 2 + > .../userspace-api/media/v4l/user-func.rst | 1 + > .../media/v4l/vidioc-subdev-g-routing.rst | 150 ++++++++++++++++++ > 3 files changed, 153 insertions(+) > create mode 100644 Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst > index fd1de0a73a9f..a67c2749089a 100644 > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst > @@ -29,6 +29,8 @@ will feature a character device node on which ioctls can be called to > > - negotiate image formats on individual pads > > +- inspect and modify internal data routing between pads of the same entity > + > Sub-device character device nodes, conventionally named > ``/dev/v4l-subdev*``, use major number 81. > > diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst > index 53e604bd7d60..228c1521f190 100644 > --- a/Documentation/userspace-api/media/v4l/user-func.rst > +++ b/Documentation/userspace-api/media/v4l/user-func.rst > @@ -70,6 +70,7 @@ Function Reference > vidioc-subdev-g-crop > vidioc-subdev-g-fmt > vidioc-subdev-g-frame-interval > + vidioc-subdev-g-routing > vidioc-subdev-g-selection > vidioc-subdev-querycap > vidioc-subscribe-event > diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst > new file mode 100644 > index 000000000000..a0d9c79e162f > --- /dev/null > +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst > @@ -0,0 +1,150 @@ > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > +.. c:namespace:: V4L > + > +.. _VIDIOC_SUBDEV_G_ROUTING: > + > +****************************************************** > +ioctl VIDIOC_SUBDEV_G_ROUTING, VIDIOC_SUBDEV_S_ROUTING > +****************************************************** > + > +Name > +==== > + > +VIDIOC_SUBDEV_G_ROUTING - VIDIOC_SUBDEV_S_ROUTING - Get or set routing between streams of media pads in a media entity. > + > + > +Synopsis > +======== > + > +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_ROUTING, struct v4l2_subdev_routing *argp ) > + :name: VIDIOC_SUBDEV_G_ROUTING > + > +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_ROUTING, struct v4l2_subdev_routing *argp ) > + :name: VIDIOC_SUBDEV_S_ROUTING > + > + > +Arguments > +========= > + > +``fd`` > + File descriptor returned by :ref:`open() <func-open>`. > + > +``argp`` > + Pointer to struct :c:type:`v4l2_subdev_routing`. > + > + > +Description > +=========== > + > +These ioctls are used to get and set the routing in a media entity. > +The routing configuration determines the flows of data inside an entity. > + > +Drivers report their current routing tables using the > +``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes > +with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and > +setting or clearing flags of the ``flags`` field of a > +struct :c:type:`v4l2_subdev_route`. > + > +All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. This > +means that the userspace mut reconfigure all streams after calling the ioctl s/mut/must/ > +with e.g. ``VIDIOC_SUBDEV_S_FMT``. > + > +A special case for routing are routes marked with > +``V4L2_SUBDEV_ROUTE_FL_SOURCE`` flag. These routes are used to describe > +source endpoints on sensors and the sink fields are unused. > + > +When inspecting routes through ``VIDIOC_SUBDEV_G_ROUTING`` and the application > +provided ``num_routes`` is not big enough to contain all the available routes > +the subdevice exposes, drivers return the ENOSPC error code and adjust the > +value of the ``num_routes`` field. Application should then reserve enough memory > +for all the route entries and call ``VIDIOC_SUBDEV_G_ROUTING`` again. > + > +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| > + > +.. c:type:: v4l2_subdev_routing > + > +.. flat-table:: struct v4l2_subdev_routing > + :header-rows: 0 > + :stub-columns: 0 > + :widths: 1 1 2 > + > + * - __u32 > + - ``which`` > + - Format to modified, from enum > + :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. > + * - struct :c:type:`v4l2_subdev_route` > + - ``routes[]`` > + - Array of struct :c:type:`v4l2_subdev_route` entries > + * - __u32 > + - ``num_routes`` > + - Number of entries of the routes array > + * - __u32 > + - ``reserved``\ [5] > + - Reserved for future extensions. Applications and drivers must set > + the array to zero. > + > +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| > + > +.. c:type:: v4l2_subdev_route > + > +.. flat-table:: struct v4l2_subdev_route > + :header-rows: 0 > + :stub-columns: 0 > + :widths: 1 1 2 > + > + * - __u32 > + - ``sink_pad`` > + - Sink pad number. > + * - __u32 > + - ``sink_stream`` > + - Sink pad stream number. > + * - __u32 > + - ``source_pad`` > + - Source pad number. > + * - __u32 > + - ``source_stream`` > + - Source pad stream number. > + * - __u32 > + - ``flags`` > + - Route enable/disable flags > + :ref:`v4l2_subdev_routing_flags <v4l2-subdev-routing-flags>`. > + * - __u32 > + - ``reserved``\ [5] > + - Reserved for future extensions. Applications and drivers must set > + the array to zero. > + > +.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| > + > +.. _v4l2-subdev-routing-flags: > + > +.. flat-table:: enum v4l2_subdev_routing_flags > + :header-rows: 0 > + :stub-columns: 0 > + :widths: 3 1 4 > + > + * - V4L2_SUBDEV_ROUTE_FL_ACTIVE > + - 0 > + - The route is enabled. Set by applications. > + * - V4L2_SUBDEV_ROUTE_FL_IMMUTABLE > + - 1 > + - The route is immutable. Set by the driver. > + * - V4L2_SUBDEV_ROUTE_FL_SOURCE > + - 2 > + - The route is a source route, and the ``sink_pad`` and ``sink_stream`` > + fields are unused. Set by the driver. > + > +Return Value > +============ > + > +On success 0 is returned, on error -1 and the ``errno`` variable is set > +appropriately. The generic error codes are described at the > +:ref:`Generic Error Codes <gen-errors>` chapter. > + > +ENOSPC > + The number of provided route entries is less than the available ones. This doesn't sound right. Maybe: "The number of route entries provided is less than the available routes on the device." But presumably this would be opposites for G_ROUTING and S_ROUTING, where on G_ROUTING the userspace must provide at least as many route entries as the driver/device has, and on S_ROUTING, they must provide not more than? > + > +EINVAL > + The sink or source pad identifiers reference a non-existing pad, or reference > + pads of different types (ie. the sink_pad identifiers refers to a source pad) > + or the sink or source stream identifiers reference a non-existing stream on > + the sink or source pad. > -- > 2.25.1 >
Quoting Kieran Bingham (2022-02-03 10:55:05) > Quoting Tomi Valkeinen (2021-11-30 14:15:25) > > From: Jacopo Mondi <jacopo+renesas@jmondi.org> > > > > Add documentation for VIDIOC_SUBDEV_G/S_ROUTING ioctl and add > > description of multiplexed media pads and internal routing to the > > V4L2-subdev documentation section. > > > > Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org> > > Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> > > Reviewed-by: Hans Verkuil <hverkuil-cisco@xs4all.nl> > > --- > > .../userspace-api/media/v4l/dev-subdev.rst | 2 + > > .../userspace-api/media/v4l/user-func.rst | 1 + > > .../media/v4l/vidioc-subdev-g-routing.rst | 150 ++++++++++++++++++ > > 3 files changed, 153 insertions(+) > > create mode 100644 Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst > > > > diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > index fd1de0a73a9f..a67c2749089a 100644 > > --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst > > +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst > > @@ -29,6 +29,8 @@ will feature a character device node on which ioctls can be called to > > > > - negotiate image formats on individual pads > > > > +- inspect and modify internal data routing between pads of the same entity > > + > > Sub-device character device nodes, conventionally named > > ``/dev/v4l-subdev*``, use major number 81. > > > > diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst > > index 53e604bd7d60..228c1521f190 100644 > > --- a/Documentation/userspace-api/media/v4l/user-func.rst > > +++ b/Documentation/userspace-api/media/v4l/user-func.rst > > @@ -70,6 +70,7 @@ Function Reference > > vidioc-subdev-g-crop > > vidioc-subdev-g-fmt > > vidioc-subdev-g-frame-interval > > + vidioc-subdev-g-routing > > vidioc-subdev-g-selection > > vidioc-subdev-querycap > > vidioc-subscribe-event > > diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst > > new file mode 100644 > > index 000000000000..a0d9c79e162f > > --- /dev/null > > +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst > > @@ -0,0 +1,150 @@ > > +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later > > +.. c:namespace:: V4L > > + > > +.. _VIDIOC_SUBDEV_G_ROUTING: > > + > > +****************************************************** > > +ioctl VIDIOC_SUBDEV_G_ROUTING, VIDIOC_SUBDEV_S_ROUTING > > +****************************************************** > > + > > +Name > > +==== > > + > > +VIDIOC_SUBDEV_G_ROUTING - VIDIOC_SUBDEV_S_ROUTING - Get or set routing between streams of media pads in a media entity. > > + > > + > > +Synopsis > > +======== > > + > > +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_ROUTING, struct v4l2_subdev_routing *argp ) > > + :name: VIDIOC_SUBDEV_G_ROUTING > > + > > +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_ROUTING, struct v4l2_subdev_routing *argp ) > > + :name: VIDIOC_SUBDEV_S_ROUTING > > + > > + > > +Arguments > > +========= > > + > > +``fd`` > > + File descriptor returned by :ref:`open() <func-open>`. > > + > > +``argp`` > > + Pointer to struct :c:type:`v4l2_subdev_routing`. > > + > > + > > +Description > > +=========== > > + > > +These ioctls are used to get and set the routing in a media entity. > > +The routing configuration determines the flows of data inside an entity. > > + > > +Drivers report their current routing tables using the > > +``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes > > +with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and > > +setting or clearing flags of the ``flags`` field of a > > +struct :c:type:`v4l2_subdev_route`. > > + > > +All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. This > > +means that the userspace mut reconfigure all streams after calling the ioctl > > s/mut/must/ > > > +with e.g. ``VIDIOC_SUBDEV_S_FMT``. > > + > > +A special case for routing are routes marked with > > +``V4L2_SUBDEV_ROUTE_FL_SOURCE`` flag. These routes are used to describe > > +source endpoints on sensors and the sink fields are unused. > > + > > +When inspecting routes through ``VIDIOC_SUBDEV_G_ROUTING`` and the application > > +provided ``num_routes`` is not big enough to contain all the available routes > > +the subdevice exposes, drivers return the ENOSPC error code and adjust the > > +value of the ``num_routes`` field. Application should then reserve enough memory > > +for all the route entries and call ``VIDIOC_SUBDEV_G_ROUTING`` again. > > + > > +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| > > + > > +.. c:type:: v4l2_subdev_routing > > + > > +.. flat-table:: struct v4l2_subdev_routing > > + :header-rows: 0 > > + :stub-columns: 0 > > + :widths: 1 1 2 > > + > > + * - __u32 > > + - ``which`` > > + - Format to modified, from enum > > + :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. > > + * - struct :c:type:`v4l2_subdev_route` > > + - ``routes[]`` > > + - Array of struct :c:type:`v4l2_subdev_route` entries > > + * - __u32 > > + - ``num_routes`` > > + - Number of entries of the routes array > > + * - __u32 > > + - ``reserved``\ [5] > > + - Reserved for future extensions. Applications and drivers must set > > + the array to zero. > > + > > +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| > > + > > +.. c:type:: v4l2_subdev_route > > + > > +.. flat-table:: struct v4l2_subdev_route > > + :header-rows: 0 > > + :stub-columns: 0 > > + :widths: 1 1 2 > > + > > + * - __u32 > > + - ``sink_pad`` > > + - Sink pad number. > > + * - __u32 > > + - ``sink_stream`` > > + - Sink pad stream number. > > + * - __u32 > > + - ``source_pad`` > > + - Source pad number. > > + * - __u32 > > + - ``source_stream`` > > + - Source pad stream number. > > + * - __u32 > > + - ``flags`` > > + - Route enable/disable flags > > + :ref:`v4l2_subdev_routing_flags <v4l2-subdev-routing-flags>`. > > + * - __u32 > > + - ``reserved``\ [5] > > + - Reserved for future extensions. Applications and drivers must set > > + the array to zero. > > + > > +.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| > > + > > +.. _v4l2-subdev-routing-flags: > > + > > +.. flat-table:: enum v4l2_subdev_routing_flags > > + :header-rows: 0 > > + :stub-columns: 0 > > + :widths: 3 1 4 > > + > > + * - V4L2_SUBDEV_ROUTE_FL_ACTIVE > > + - 0 > > + - The route is enabled. Set by applications. > > + * - V4L2_SUBDEV_ROUTE_FL_IMMUTABLE > > + - 1 > > + - The route is immutable. Set by the driver. > > + * - V4L2_SUBDEV_ROUTE_FL_SOURCE > > + - 2 > > + - The route is a source route, and the ``sink_pad`` and ``sink_stream`` > > + fields are unused. Set by the driver. > > + > > +Return Value > > +============ > > + > > +On success 0 is returned, on error -1 and the ``errno`` variable is set > > +appropriately. The generic error codes are described at the > > +:ref:`Generic Error Codes <gen-errors>` chapter. > > + > > +ENOSPC > > + The number of provided route entries is less than the available ones. > > This doesn't sound right. Maybe: > > "The number of route entries provided is less than the available > routes on the device." > > But presumably this would be opposites for G_ROUTING and S_ROUTING, > where on G_ROUTING the userspace must provide at least as many route > entries as the driver/device has, and on S_ROUTING, they must provide > not more than? Aha, now I see in the next patch that it only really applies to the G_ROUTING. But it might be worth noting that if -ENOSPC is returned, num_routes is set to the number of routes required by the kernel. -- Kieran > > > > > + > > +EINVAL > > + The sink or source pad identifiers reference a non-existing pad, or reference > > + pads of different types (ie. the sink_pad identifiers refers to a source pad) > > + or the sink or source stream identifiers reference a non-existing stream on > > + the sink or source pad. > > -- > > 2.25.1 > >
diff --git a/Documentation/userspace-api/media/v4l/dev-subdev.rst b/Documentation/userspace-api/media/v4l/dev-subdev.rst index fd1de0a73a9f..a67c2749089a 100644 --- a/Documentation/userspace-api/media/v4l/dev-subdev.rst +++ b/Documentation/userspace-api/media/v4l/dev-subdev.rst @@ -29,6 +29,8 @@ will feature a character device node on which ioctls can be called to - negotiate image formats on individual pads +- inspect and modify internal data routing between pads of the same entity + Sub-device character device nodes, conventionally named ``/dev/v4l-subdev*``, use major number 81. diff --git a/Documentation/userspace-api/media/v4l/user-func.rst b/Documentation/userspace-api/media/v4l/user-func.rst index 53e604bd7d60..228c1521f190 100644 --- a/Documentation/userspace-api/media/v4l/user-func.rst +++ b/Documentation/userspace-api/media/v4l/user-func.rst @@ -70,6 +70,7 @@ Function Reference vidioc-subdev-g-crop vidioc-subdev-g-fmt vidioc-subdev-g-frame-interval + vidioc-subdev-g-routing vidioc-subdev-g-selection vidioc-subdev-querycap vidioc-subscribe-event diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst new file mode 100644 index 000000000000..a0d9c79e162f --- /dev/null +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-routing.rst @@ -0,0 +1,150 @@ +.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later +.. c:namespace:: V4L + +.. _VIDIOC_SUBDEV_G_ROUTING: + +****************************************************** +ioctl VIDIOC_SUBDEV_G_ROUTING, VIDIOC_SUBDEV_S_ROUTING +****************************************************** + +Name +==== + +VIDIOC_SUBDEV_G_ROUTING - VIDIOC_SUBDEV_S_ROUTING - Get or set routing between streams of media pads in a media entity. + + +Synopsis +======== + +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_G_ROUTING, struct v4l2_subdev_routing *argp ) + :name: VIDIOC_SUBDEV_G_ROUTING + +.. c:function:: int ioctl( int fd, VIDIOC_SUBDEV_S_ROUTING, struct v4l2_subdev_routing *argp ) + :name: VIDIOC_SUBDEV_S_ROUTING + + +Arguments +========= + +``fd`` + File descriptor returned by :ref:`open() <func-open>`. + +``argp`` + Pointer to struct :c:type:`v4l2_subdev_routing`. + + +Description +=========== + +These ioctls are used to get and set the routing in a media entity. +The routing configuration determines the flows of data inside an entity. + +Drivers report their current routing tables using the +``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes +with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and +setting or clearing flags of the ``flags`` field of a +struct :c:type:`v4l2_subdev_route`. + +All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. This +means that the userspace mut reconfigure all streams after calling the ioctl +with e.g. ``VIDIOC_SUBDEV_S_FMT``. + +A special case for routing are routes marked with +``V4L2_SUBDEV_ROUTE_FL_SOURCE`` flag. These routes are used to describe +source endpoints on sensors and the sink fields are unused. + +When inspecting routes through ``VIDIOC_SUBDEV_G_ROUTING`` and the application +provided ``num_routes`` is not big enough to contain all the available routes +the subdevice exposes, drivers return the ENOSPC error code and adjust the +value of the ``num_routes`` field. Application should then reserve enough memory +for all the route entries and call ``VIDIOC_SUBDEV_G_ROUTING`` again. + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| + +.. c:type:: v4l2_subdev_routing + +.. flat-table:: struct v4l2_subdev_routing + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``which`` + - Format to modified, from enum + :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. + * - struct :c:type:`v4l2_subdev_route` + - ``routes[]`` + - Array of struct :c:type:`v4l2_subdev_route` entries + * - __u32 + - ``num_routes`` + - Number of entries of the routes array + * - __u32 + - ``reserved``\ [5] + - Reserved for future extensions. Applications and drivers must set + the array to zero. + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| + +.. c:type:: v4l2_subdev_route + +.. flat-table:: struct v4l2_subdev_route + :header-rows: 0 + :stub-columns: 0 + :widths: 1 1 2 + + * - __u32 + - ``sink_pad`` + - Sink pad number. + * - __u32 + - ``sink_stream`` + - Sink pad stream number. + * - __u32 + - ``source_pad`` + - Source pad number. + * - __u32 + - ``source_stream`` + - Source pad stream number. + * - __u32 + - ``flags`` + - Route enable/disable flags + :ref:`v4l2_subdev_routing_flags <v4l2-subdev-routing-flags>`. + * - __u32 + - ``reserved``\ [5] + - Reserved for future extensions. Applications and drivers must set + the array to zero. + +.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| + +.. _v4l2-subdev-routing-flags: + +.. flat-table:: enum v4l2_subdev_routing_flags + :header-rows: 0 + :stub-columns: 0 + :widths: 3 1 4 + + * - V4L2_SUBDEV_ROUTE_FL_ACTIVE + - 0 + - The route is enabled. Set by applications. + * - V4L2_SUBDEV_ROUTE_FL_IMMUTABLE + - 1 + - The route is immutable. Set by the driver. + * - V4L2_SUBDEV_ROUTE_FL_SOURCE + - 2 + - The route is a source route, and the ``sink_pad`` and ``sink_stream`` + fields are unused. Set by the driver. + +Return Value +============ + +On success 0 is returned, on error -1 and the ``errno`` variable is set +appropriately. The generic error codes are described at the +:ref:`Generic Error Codes <gen-errors>` chapter. + +ENOSPC + The number of provided route entries is less than the available ones. + +EINVAL + The sink or source pad identifiers reference a non-existing pad, or reference + pads of different types (ie. the sink_pad identifiers refers to a source pad) + or the sink or source stream identifiers reference a non-existing stream on + the sink or source pad.