diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-g-ctrl.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-g-ctrl.rst | 43 |
1 files changed, 18 insertions, 25 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-ctrl.rst b/Documentation/media/uapi/v4l/vidioc-g-ctrl.rst index ee929f692ebe..d8a379182a34 100644 --- a/Documentation/media/uapi/v4l/vidioc-g-ctrl.rst +++ b/Documentation/media/uapi/v4l/vidioc-g-ctrl.rst @@ -15,7 +15,11 @@ VIDIOC_G_CTRL - VIDIOC_S_CTRL - Get or set the value of a control Synopsis ======== -.. cpp:function:: int ioctl( int fd, int request, struct v4l2_control *argp ) +.. 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 @@ -24,9 +28,6 @@ Arguments ``fd`` File descriptor returned by :ref:`open() <func-open>`. -``request`` - VIDIOC_G_CTRL, VIDIOC_S_CTRL - ``argp`` @@ -34,10 +35,10 @@ Description =========== To get the current value of a control applications initialize the ``id`` -field of a struct :ref:`struct v4l2_control <v4l2-control>` and call the +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 :ref:`struct v4l2_control <v4l2-control>` and call the +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 @@ -54,29 +55,21 @@ These ioctls work only with user controls. For other control classes the :ref:`VIDIOC_TRY_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` must be used. -.. _v4l2-control: +.. 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 - - - .. row 1 - - - __u32 - - - ``id`` - - - Identifies the control, set by the application. - - - .. row 2 - - - __s32 - - - ``value`` - - - New value or current value. + * - __u32 + - ``id`` + - Identifies the control, set by the application. + * - __s32 + - ``value`` + - New value or current value. Return Value @@ -87,13 +80,13 @@ appropriately. The generic error codes are described at the :ref:`Generic Error Codes <gen-errors>` chapter. EINVAL - The struct :ref:`v4l2_control <v4l2-control>` ``id`` is invalid + 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 :ref:`v4l2_control <v4l2-control>` ``value`` is out of + The struct :c:type:`v4l2_control` ``value`` is out of bounds. EBUSY |