diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-dbg-g-chip-info.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-dbg-g-chip-info.rst | 167 |
1 files changed, 0 insertions, 167 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-dbg-g-chip-info.rst b/Documentation/media/uapi/v4l/vidioc-dbg-g-chip-info.rst deleted file mode 100644 index d38031dbe4e4..000000000000 --- a/Documentation/media/uapi/v4l/vidioc-dbg-g-chip-info.rst +++ /dev/null @@ -1,167 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -.. _VIDIOC_DBG_G_CHIP_INFO: - -**************************** -ioctl VIDIOC_DBG_G_CHIP_INFO -**************************** - -Name -==== - -VIDIOC_DBG_G_CHIP_INFO - Identify the chips on a TV card - - -Synopsis -======== - -.. c:function:: int ioctl( int fd, VIDIOC_DBG_G_CHIP_INFO, struct v4l2_dbg_chip_info *argp ) - :name: VIDIOC_DBG_G_CHIP_INFO - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <func-open>`. - -``argp`` - Pointer to struct :c:type:`v4l2_dbg_chip_info`. - - -Description -=========== - -.. note:: - - This is an :ref:`experimental` interface and may - change in the future. - -For driver debugging purposes this ioctl allows test applications to -query the driver about the chips present on the TV card. Regular -applications must not use it. When you found a chip specific bug, please -contact the linux-media mailing list -(`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__) -so it can be fixed. - -Additionally the Linux kernel must be compiled with the -``CONFIG_VIDEO_ADV_DEBUG`` option to enable this ioctl. - -To query the driver applications must initialize the ``match.type`` and -``match.addr`` or ``match.name`` fields of a struct -:c:type:`v4l2_dbg_chip_info` and call -:ref:`VIDIOC_DBG_G_CHIP_INFO` with a pointer to this structure. On success -the driver stores information about the selected chip in the ``name`` -and ``flags`` fields. - -When ``match.type`` is ``V4L2_CHIP_MATCH_BRIDGE``, ``match.addr`` -selects the nth bridge 'chip' on the TV card. You can enumerate all -chips by starting at zero and incrementing ``match.addr`` by one until -:ref:`VIDIOC_DBG_G_CHIP_INFO` fails with an ``EINVAL`` error code. The number -zero always selects the bridge chip itself, e. g. the chip connected to -the PCI or USB bus. Non-zero numbers identify specific parts of the -bridge chip such as an AC97 register block. - -When ``match.type`` is ``V4L2_CHIP_MATCH_SUBDEV``, ``match.addr`` -selects the nth sub-device. This allows you to enumerate over all -sub-devices. - -On success, the ``name`` field will contain a chip name and the -``flags`` field will contain ``V4L2_CHIP_FL_READABLE`` if the driver -supports reading registers from the device or ``V4L2_CHIP_FL_WRITABLE`` -if the driver supports writing registers to the device. - -We recommended the v4l2-dbg utility over calling this ioctl directly. It -is available from the LinuxTV v4l-dvb repository; see -`https://linuxtv.org/repo/ <https://linuxtv.org/repo/>`__ for access -instructions. - - -.. tabularcolumns:: |p{3.5cm}|p{3.5cm}|p{3.5cm}|p{7.0cm}| - -.. _name-v4l2-dbg-match: - -.. flat-table:: struct v4l2_dbg_match - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``type`` - - See :ref:`name-chip-match-types` for a list of possible types. - * - union { - - (anonymous) - * - __u32 - - ``addr`` - - Match a chip by this number, interpreted according to the ``type`` - field. - * - char - - ``name[32]`` - - Match a chip by this name, interpreted according to the ``type`` - field. Currently unused. - * - } - - - - - -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| - -.. c:type:: v4l2_dbg_chip_info - -.. flat-table:: struct v4l2_dbg_chip_info - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - struct v4l2_dbg_match - - ``match`` - - How to match the chip, see :ref:`name-v4l2-dbg-match`. - * - char - - ``name[32]`` - - The name of the chip. - * - __u32 - - ``flags`` - - Set by the driver. If ``V4L2_CHIP_FL_READABLE`` is set, then the - driver supports reading registers from the device. If - ``V4L2_CHIP_FL_WRITABLE`` is set, then it supports writing - registers. - * - __u32 - - ``reserved[8]`` - - Reserved fields, both application and driver must set these to 0. - - - -.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| - -.. _name-chip-match-types: - -.. flat-table:: Chip Match Types - :header-rows: 0 - :stub-columns: 0 - :widths: 3 1 4 - - * - ``V4L2_CHIP_MATCH_BRIDGE`` - - 0 - - Match the nth chip on the card, zero for the bridge chip. Does not - match sub-devices. - * - ``V4L2_CHIP_MATCH_SUBDEV`` - - 4 - - Match the nth sub-device. - - -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. - -EINVAL - The ``match_type`` is invalid or no device could be matched. |