diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-g-frequency.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-g-frequency.rst | 91 |
1 files changed, 36 insertions, 55 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-g-frequency.rst b/Documentation/media/uapi/v4l/vidioc-g-frequency.rst index a1fd2a8..46ab276 100644 --- a/Documentation/media/uapi/v4l/vidioc-g-frequency.rst +++ b/Documentation/media/uapi/v4l/vidioc-g-frequency.rst @@ -15,9 +15,11 @@ VIDIOC_G_FREQUENCY - VIDIOC_S_FREQUENCY - Get or set tuner or modulator radio fr Synopsis ======== -.. cpp:function:: int ioctl( int fd, int request, struct v4l2_frequency *argp ) +.. c:function:: int ioctl( int fd, VIDIOC_G_FREQUENCY, struct v4l2_frequency *argp ) + :name: VIDIOC_G_FREQUENCY -.. cpp:function:: int ioctl( int fd, int request, const struct v4l2_frequency *argp ) +.. c:function:: int ioctl( int fd, VIDIOC_S_FREQUENCY, const struct v4l2_frequency *argp ) + :name: VIDIOC_S_FREQUENCY Arguments @@ -26,9 +28,6 @@ Arguments ``fd`` File descriptor returned by :ref:`open() <func-open>`. -``request`` - VIDIOC_G_FREQUENCY, VIDIOC_S_FREQUENCY - ``argp`` @@ -37,7 +36,7 @@ Description To get the current tuner or modulator radio frequency applications set the ``tuner`` field of a struct -:ref:`v4l2_frequency <v4l2-frequency>` to the respective tuner or +:c:type:`v4l2_frequency` to the respective tuner or modulator number (only input devices have tuners, only output devices have modulators), zero out the ``reserved`` array and call the :ref:`VIDIOC_G_FREQUENCY <VIDIOC_G_FREQUENCY>` ioctl with a pointer to this structure. The @@ -45,67 +44,49 @@ driver stores the current frequency in the ``frequency`` field. To change the current tuner or modulator radio frequency applications initialize the ``tuner``, ``type`` and ``frequency`` fields, and the -``reserved`` array of a struct :ref:`v4l2_frequency <v4l2-frequency>` +``reserved`` array of a struct :c:type:`v4l2_frequency` and call the :ref:`VIDIOC_S_FREQUENCY <VIDIOC_G_FREQUENCY>` ioctl with a pointer to this structure. When the requested frequency is not possible the driver assumes the closest possible value. However :ref:`VIDIOC_S_FREQUENCY <VIDIOC_G_FREQUENCY>` is a write-only ioctl, it does not return the actual new frequency. -.. _v4l2-frequency: +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| + +.. c:type:: v4l2_frequency .. flat-table:: struct v4l2_frequency :header-rows: 0 :stub-columns: 0 :widths: 1 1 2 - - - .. row 1 - - - __u32 - - - ``tuner`` - - - The tuner or modulator index number. This is the same value as in - the struct :ref:`v4l2_input <v4l2-input>` ``tuner`` field and - the struct :ref:`v4l2_tuner <v4l2-tuner>` ``index`` field, or - the struct :ref:`v4l2_output <v4l2-output>` ``modulator`` field - and the struct :ref:`v4l2_modulator <v4l2-modulator>` ``index`` - field. - - - .. row 2 - - - __u32 - - - ``type`` - - - The tuner type. This is the same value as in the struct - :ref:`v4l2_tuner <v4l2-tuner>` ``type`` field. The type must be - set to ``V4L2_TUNER_RADIO`` for ``/dev/radioX`` device nodes, and - to ``V4L2_TUNER_ANALOG_TV`` for all others. Set this field to - ``V4L2_TUNER_RADIO`` for modulators (currently only radio - modulators are supported). See :ref:`v4l2-tuner-type` - - - .. row 3 - - - __u32 - - - ``frequency`` - - - Tuning frequency in units of 62.5 kHz, or if the struct - :ref:`v4l2_tuner <v4l2-tuner>` or struct - :ref:`v4l2_modulator <v4l2-modulator>` ``capability`` flag - ``V4L2_TUNER_CAP_LOW`` is set, in units of 62.5 Hz. A 1 Hz unit is - used when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set. - - - .. row 4 - - - __u32 - - - ``reserved``\ [8] - - - Reserved for future extensions. Drivers and applications must set - the array to zero. + * - __u32 + - ``tuner`` + - The tuner or modulator index number. This is the same value as in + the struct :c:type:`v4l2_input` ``tuner`` field and + the struct :c:type:`v4l2_tuner` ``index`` field, or + the struct :c:type:`v4l2_output` ``modulator`` field + and the struct :c:type:`v4l2_modulator` ``index`` + field. + * - __u32 + - ``type`` + - The tuner type. This is the same value as in the struct + :c:type:`v4l2_tuner` ``type`` field. The type must be + set to ``V4L2_TUNER_RADIO`` for ``/dev/radioX`` device nodes, and + to ``V4L2_TUNER_ANALOG_TV`` for all others. Set this field to + ``V4L2_TUNER_RADIO`` for modulators (currently only radio + modulators are supported). See :c:type:`v4l2_tuner_type` + * - __u32 + - ``frequency`` + - Tuning frequency in units of 62.5 kHz, or if the struct + :c:type:`v4l2_tuner` or struct + :c:type:`v4l2_modulator` ``capability`` flag + ``V4L2_TUNER_CAP_LOW`` is set, in units of 62.5 Hz. A 1 Hz unit is + used when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set. + * - __u32 + - ``reserved``\ [8] + - Reserved for future extensions. Drivers and applications must set + the array to zero. Return Value |