^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) .. c:namespace:: V4L
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) .. _VIDIOC_G_EDID:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) ******************************************************************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) ioctl VIDIOC_G_EDID, VIDIOC_S_EDID, VIDIOC_SUBDEV_G_EDID, VIDIOC_SUBDEV_S_EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) ******************************************************************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) Name
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) ====
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) VIDIOC_G_EDID - VIDIOC_S_EDID - VIDIOC_SUBDEV_G_EDID - VIDIOC_SUBDEV_S_EDID - Get or set the EDID of a video receiver/transmitter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) Synopsis
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) ========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) .. c:macro:: VIDIOC_G_EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) ``int ioctl(int fd, VIDIOC_G_EDID, struct v4l2_edid *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) .. c:macro:: VIDIOC_S_EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) ``int ioctl(int fd, VIDIOC_S_EDID, struct v4l2_edid *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) .. c:macro:: VIDIOC_SUBDEV_G_EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) ``int ioctl(int fd, VIDIOC_SUBDEV_G_EDID, struct v4l2_edid *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) .. c:macro:: VIDIOC_SUBDEV_S_EDID
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) ``int ioctl(int fd, VIDIOC_SUBDEV_S_EDID, struct v4l2_edid *argp)``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) Arguments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) =========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) ``fd``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) File descriptor returned by :c:func:`open()`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) ``argp``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) Pointer to struct :c:type:`v4l2_edid`.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) Description
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) ===========
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) These ioctls can be used to get or set an EDID associated with an input
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) from a receiver or an output of a transmitter device. They can be used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) with subdevice nodes (/dev/v4l-subdevX) or with video nodes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) (/dev/videoX).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) When used with video nodes the ``pad`` field represents the input (for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) video capture devices) or output (for video output devices) index as is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) returned by :ref:`VIDIOC_ENUMINPUT` and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) :ref:`VIDIOC_ENUMOUTPUT` respectively. When used
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) with subdevice nodes the ``pad`` field represents the input or output
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) pad of the subdevice. If there is no EDID support for the given ``pad``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) value, then the ``EINVAL`` error code will be returned.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) To get the EDID data the application has to fill in the ``pad``,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) ``start_block``, ``blocks`` and ``edid`` fields, zero the ``reserved``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) array and call :ref:`VIDIOC_G_EDID <VIDIOC_G_EDID>`. The current EDID from block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) ``start_block`` and of size ``blocks`` will be placed in the memory
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) ``edid`` points to. The ``edid`` pointer must point to memory at least
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) ``blocks`` * 128 bytes large (the size of one block is 128 bytes).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) If there are fewer blocks than specified, then the driver will set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) ``blocks`` to the actual number of blocks. If there are no EDID blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) available at all, then the error code ``ENODATA`` is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) If blocks have to be retrieved from the sink, then this call will block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) until they have been read.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) If ``start_block`` and ``blocks`` are both set to 0 when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) :ref:`VIDIOC_G_EDID <VIDIOC_G_EDID>` is called, then the driver will set ``blocks`` to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) total number of available EDID blocks and it will return 0 without
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) copying any data. This is an easy way to discover how many EDID blocks
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) there are.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) .. note::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) If there are no EDID blocks available at all, then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) the driver will set ``blocks`` to 0 and it returns 0.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) To set the EDID blocks of a receiver the application has to fill in the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) ``pad``, ``blocks`` and ``edid`` fields, set ``start_block`` to 0 and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) zero the ``reserved`` array. It is not possible to set part of an EDID,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) it is always all or nothing. Setting the EDID data is only valid for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) receivers as it makes no sense for a transmitter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) The driver assumes that the full EDID is passed in. If there are more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) EDID blocks than the hardware can handle then the EDID is not written,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) but instead the error code ``E2BIG`` is set and ``blocks`` is set to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) maximum that the hardware supports. If ``start_block`` is any value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) other than 0 then the error code ``EINVAL`` is set.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) To disable an EDID you set ``blocks`` to 0. Depending on the hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) this will drive the hotplug pin low and/or block the source from reading
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) the EDID data in some way. In any case, the end result is the same: the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) EDID is no longer available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) .. c:type:: v4l2_edid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) .. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) .. flat-table:: struct v4l2_edid
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) :header-rows: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) :stub-columns: 0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) :widths: 1 1 2
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) - ``pad``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) - Pad for which to get/set the EDID blocks. When used with a video
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) device node the pad represents the input or output index as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) returned by :ref:`VIDIOC_ENUMINPUT` and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) :ref:`VIDIOC_ENUMOUTPUT` respectively.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) - ``start_block``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) - Read the EDID from starting with this block. Must be 0 when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) setting the EDID.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) - ``blocks``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) - The number of blocks to get or set. Must be less or equal to 256
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) (the maximum number of blocks as defined by the standard). When
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) you set the EDID and ``blocks`` is 0, then the EDID is disabled or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) erased.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) * - __u32
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) - ``reserved``\ [5]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) - Reserved for future extensions. Applications and drivers must set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) the array to zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) * - __u8 *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) - ``edid``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) - Pointer to memory that contains the EDID. The minimum size is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) ``blocks`` * 128.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) Return Value
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) ============
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) On success 0 is returned, on error -1 and the ``errno`` variable is set
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) appropriately. The generic error codes are described at the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) :ref:`Generic Error Codes <gen-errors>` chapter.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) ``ENODATA``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) The EDID data is not available.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) ``E2BIG``
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) The EDID data you provided is more than the hardware can handle.
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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