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Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-g-ctrl.rst')
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diff --git a/Documentation/media/uapi/v4l/vidioc-g-ctrl.rst b/Documentation/media/uapi/v4l/vidioc-g-ctrl.rst deleted file mode 100644 index 8493b52adbb2..000000000000 --- a/Documentation/media/uapi/v4l/vidioc-g-ctrl.rst +++ /dev/null @@ -1,106 +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_G_CTRL: - -********************************** -ioctl VIDIOC_G_CTRL, VIDIOC_S_CTRL -********************************** - -Name -==== - -VIDIOC_G_CTRL - VIDIOC_S_CTRL - Get or set the value of a control - - -Synopsis -======== - -.. c:function:: int ioctl( int fd, VIDIOC_G_CTRL, struct v4l2_control *argp ) - :name: VIDIOC_G_CTRL - -.. c:function:: int ioctl( int fd, VIDIOC_S_CTRL, struct v4l2_control *argp ) - :name: VIDIOC_S_CTRL - - -Arguments -========= - -``fd`` - File descriptor returned by :ref:`open() <func-open>`. - -``argp`` - Pointer to struct :c:type:`v4l2_control`. - - -Description -=========== - -To get the current value of a control applications initialize the ``id`` -field of a struct :c:type:`v4l2_control` and call the -:ref:`VIDIOC_G_CTRL <VIDIOC_G_CTRL>` ioctl with a pointer to this structure. To change the -value of a control applications initialize the ``id`` and ``value`` -fields of a struct :c:type:`v4l2_control` and call the -:ref:`VIDIOC_S_CTRL <VIDIOC_G_CTRL>` ioctl. - -When the ``id`` is invalid drivers return an ``EINVAL`` error code. When the -``value`` is out of bounds drivers can choose to take the closest valid -value or return an ``ERANGE`` error code, whatever seems more appropriate. -However, :ref:`VIDIOC_S_CTRL <VIDIOC_G_CTRL>` is a write-only ioctl, it does not return the -actual new value. If the ``value`` is inappropriate for the control -(e.g. if it refers to an unsupported menu index of a menu control), then -EINVAL error code is returned as well. - -These ioctls work only with user controls. For other control classes the -:ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`, -:ref:`VIDIOC_S_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` or -:ref:`VIDIOC_TRY_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` must be used. - - -.. c:type:: v4l2_control - -.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| - -.. flat-table:: struct v4l2_control - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``id`` - - Identifies the control, set by the application. - * - __s32 - - ``value`` - - New value or current value. - - -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 struct :c:type:`v4l2_control` ``id`` is invalid - or the ``value`` is inappropriate for the given control (i.e. if a - menu item is selected that is not supported by the driver according - to :ref:`VIDIOC_QUERYMENU <VIDIOC_QUERYCTRL>`). - -ERANGE - The struct :c:type:`v4l2_control` ``value`` is out of - bounds. - -EBUSY - The control is temporarily not changeable, possibly because another - applications took over control of the device function this control - belongs to. - -EACCES - Attempt to set a read-only control or to get a write-only control. |