1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2.. c:namespace:: V4L 3 4.. _VIDIOC_SUBDEV_G_ROUTING: 5 6****************************************************** 7ioctl VIDIOC_SUBDEV_G_ROUTING, VIDIOC_SUBDEV_S_ROUTING 8****************************************************** 9 10Name 11==== 12 13VIDIOC_SUBDEV_G_ROUTING - VIDIOC_SUBDEV_S_ROUTING - Get or set routing between streams of media pads in a media entity. 14 15 16Synopsis 17======== 18 19.. c:macro:: VIDIOC_SUBDEV_G_ROUTING 20 21``int ioctl(int fd, VIDIOC_SUBDEV_G_ROUTING, struct v4l2_subdev_routing *argp)`` 22 23.. c:macro:: VIDIOC_SUBDEV_S_ROUTING 24 25``int ioctl(int fd, VIDIOC_SUBDEV_S_ROUTING, struct v4l2_subdev_routing *argp)`` 26 27Arguments 28========= 29 30``fd`` 31 File descriptor returned by :ref:`open() <func-open>`. 32 33``argp`` 34 Pointer to struct :c:type:`v4l2_subdev_routing`. 35 36 37Description 38=========== 39 40These ioctls are used to get and set the routing in a media entity. 41The routing configuration determines the flows of data inside an entity. 42 43Drivers report their current routing tables using the 44``VIDIOC_SUBDEV_G_ROUTING`` ioctl and application may enable or disable routes 45with the ``VIDIOC_SUBDEV_S_ROUTING`` ioctl, by adding or removing routes and 46setting or clearing flags of the ``flags`` field of a 47struct :c:type:`v4l2_subdev_route`. 48 49All stream configurations are reset when ``VIDIOC_SUBDEV_S_ROUTING`` is called. This 50means that the userspace must reconfigure all streams after calling the ioctl 51with e.g. ``VIDIOC_SUBDEV_S_FMT``. 52 53Only subdevices which have both sink and source pads can support routing. 54 55When inspecting routes through ``VIDIOC_SUBDEV_G_ROUTING`` and the application 56provided ``num_routes`` is not big enough to contain all the available routes 57the subdevice exposes, drivers return the ENOSPC error code and adjust the 58value of the ``num_routes`` field. Application should then reserve enough memory 59for all the route entries and call ``VIDIOC_SUBDEV_G_ROUTING`` again. 60 61.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| 62 63.. c:type:: v4l2_subdev_routing 64 65.. flat-table:: struct v4l2_subdev_routing 66 :header-rows: 0 67 :stub-columns: 0 68 :widths: 1 1 2 69 70 * - __u32 71 - ``which`` 72 - Format to modified, from enum 73 :ref:`v4l2_subdev_format_whence <v4l2-subdev-format-whence>`. 74 * - struct :c:type:`v4l2_subdev_route` 75 - ``routes[]`` 76 - Array of struct :c:type:`v4l2_subdev_route` entries 77 * - __u32 78 - ``num_routes`` 79 - Number of entries of the routes array 80 * - __u32 81 - ``reserved``\ [5] 82 - Reserved for future extensions. Applications and drivers must set 83 the array to zero. 84 85.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| 86 87.. c:type:: v4l2_subdev_route 88 89.. flat-table:: struct v4l2_subdev_route 90 :header-rows: 0 91 :stub-columns: 0 92 :widths: 1 1 2 93 94 * - __u32 95 - ``sink_pad`` 96 - Sink pad number. 97 * - __u32 98 - ``sink_stream`` 99 - Sink pad stream number. 100 * - __u32 101 - ``source_pad`` 102 - Source pad number. 103 * - __u32 104 - ``source_stream`` 105 - Source pad stream number. 106 * - __u32 107 - ``flags`` 108 - Route enable/disable flags 109 :ref:`v4l2_subdev_routing_flags <v4l2-subdev-routing-flags>`. 110 * - __u32 111 - ``reserved``\ [5] 112 - Reserved for future extensions. Applications and drivers must set 113 the array to zero. 114 115.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| 116 117.. _v4l2-subdev-routing-flags: 118 119.. flat-table:: enum v4l2_subdev_routing_flags 120 :header-rows: 0 121 :stub-columns: 0 122 :widths: 3 1 4 123 124 * - V4L2_SUBDEV_ROUTE_FL_ACTIVE 125 - 0 126 - The route is enabled. Set by applications. 127 128Return Value 129============ 130 131On success 0 is returned, on error -1 and the ``errno`` variable is set 132appropriately. The generic error codes are described at the 133:ref:`Generic Error Codes <gen-errors>` chapter. 134 135ENOSPC 136 The application provided ``num_routes`` is not big enough to contain 137 all the available routes the subdevice exposes. 138 139EINVAL 140 The sink or source pad identifiers reference a non-existing pad, or reference 141 pads of different types (ie. the sink_pad identifiers refers to a source pad) 142 or the sink or source stream identifiers reference a non-existing stream on 143 the sink or source pad. 144 145E2BIG 146 The application provided ``num_routes`` for ``VIDIOC_SUBDEV_S_ROUTING`` is 147 larger than the number of routes the driver can handle. 148