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Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-enum-freq-bands.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-enum-freq-bands.rst | 202 |
1 files changed, 76 insertions, 126 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-enum-freq-bands.rst b/Documentation/media/uapi/v4l/vidioc-enum-freq-bands.rst index 00ab5e19cc1d..4e5f5e5bf632 100644 --- a/Documentation/media/uapi/v4l/vidioc-enum-freq-bands.rst +++ b/Documentation/media/uapi/v4l/vidioc-enum-freq-bands.rst @@ -15,7 +15,8 @@ VIDIOC_ENUM_FREQ_BANDS - Enumerate supported frequency bands Synopsis ======== -.. cpp:function:: int ioctl( int fd, int request, struct v4l2_frequency_band *argp ) +.. c:function:: int ioctl( int fd, VIDIOC_ENUM_FREQ_BANDS, struct v4l2_frequency_band *argp ) + :name: VIDIOC_ENUM_FREQ_BANDS Arguments @@ -24,9 +25,6 @@ Arguments ``fd`` File descriptor returned by :ref:`open() <func-open>`. -``request`` - VIDIOC_ENUM_FREQ_BANDS - ``argp`` @@ -36,116 +34,83 @@ Description Enumerates the frequency bands that a tuner or modulator supports. To do this applications initialize the ``tuner``, ``type`` and ``index`` fields, and zero out the ``reserved`` array of a struct -:ref:`v4l2_frequency_band <v4l2-frequency-band>` and call the +:c:type:`v4l2_frequency_band` and call the :ref:`VIDIOC_ENUM_FREQ_BANDS` ioctl with a pointer to this structure. This ioctl is supported if the ``V4L2_TUNER_CAP_FREQ_BANDS`` capability of the corresponding tuner/modulator is set. -.. _v4l2-frequency-band: +.. tabularcolumns:: |p{2.9cm}|p{2.9cm}|p{5.8cm}|p{2.9cm}|p{3.0cm}| + +.. c:type:: v4l2_frequency_band .. flat-table:: struct v4l2_frequency_band :header-rows: 0 :stub-columns: 0 :widths: 1 1 2 1 1 - - - .. 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 - - - ``index`` - - - Identifies the frequency band, set by the application. - - - .. row 4 - - - __u32 - - - ``capability`` - - - :cspan:`2` The tuner/modulator capability flags for this - frequency band, see :ref:`tuner-capability`. The - ``V4L2_TUNER_CAP_LOW`` or ``V4L2_TUNER_CAP_1HZ`` capability must - be the same for all frequency bands of the selected - tuner/modulator. So either all bands have that capability set, or - none of them have that capability. - - - .. row 5 - - - __u32 - - - ``rangelow`` - - - :cspan:`2` The lowest tunable frequency in units of 62.5 kHz, or - if the ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units - of 62.5 Hz, for this frequency band. A 1 Hz unit is used when the - ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set. - - - .. row 6 - - - __u32 - - - ``rangehigh`` - - - :cspan:`2` The highest tunable frequency in units of 62.5 kHz, - or if the ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in - units of 62.5 Hz, for this frequency band. A 1 Hz unit is used - when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set. - - - .. row 7 - - - __u32 - - - ``modulation`` - - - :cspan:`2` The supported modulation systems of this frequency - band. See :ref:`band-modulation`. - - .. note:: Currently only one modulation system per frequency band - is supported. More work will need to be done if multiple - modulation systems are possible. Contact the linux-media - mailing list - (`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__) - if you need such functionality. - - - .. row 8 - - - __u32 - - - ``reserved``\ [9] - - - Reserved for future extensions. Applications and drivers 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 + - ``index`` + - Identifies the frequency band, set by the application. + * - __u32 + - ``capability`` + - :cspan:`2` The tuner/modulator capability flags for this + frequency band, see :ref:`tuner-capability`. The + ``V4L2_TUNER_CAP_LOW`` or ``V4L2_TUNER_CAP_1HZ`` capability must + be the same for all frequency bands of the selected + tuner/modulator. So either all bands have that capability set, or + none of them have that capability. + * - __u32 + - ``rangelow`` + - :cspan:`2` The lowest tunable frequency in units of 62.5 kHz, or + if the ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in units + of 62.5 Hz, for this frequency band. A 1 Hz unit is used when the + ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set. + * - __u32 + - ``rangehigh`` + - :cspan:`2` The highest tunable frequency in units of 62.5 kHz, + or if the ``capability`` flag ``V4L2_TUNER_CAP_LOW`` is set, in + units of 62.5 Hz, for this frequency band. A 1 Hz unit is used + when the ``capability`` flag ``V4L2_TUNER_CAP_1HZ`` is set. + * - __u32 + - ``modulation`` + - :cspan:`2` The supported modulation systems of this frequency + band. See :ref:`band-modulation`. + + .. note:: + + Currently only one modulation system per frequency band + is supported. More work will need to be done if multiple + modulation systems are possible. Contact the linux-media + mailing list + (`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__) + if you need such functionality. + * - __u32 + - ``reserved``\ [9] + - Reserved for future extensions. + + Applications and drivers must set the array to zero. + + + +.. tabularcolumns:: |p{6.6cm}|p{2.2cm}|p{8.7cm}| .. _band-modulation: @@ -154,30 +119,15 @@ of the corresponding tuner/modulator is set. :stub-columns: 0 :widths: 3 1 4 - - - .. row 1 - - - ``V4L2_BAND_MODULATION_VSB`` - - - 0x02 - - - Vestigial Sideband modulation, used for analog TV. - - - .. row 2 - - - ``V4L2_BAND_MODULATION_FM`` - - - 0x04 - - - Frequency Modulation, commonly used for analog radio. - - - .. row 3 - - - ``V4L2_BAND_MODULATION_AM`` - - - 0x08 - - - Amplitude Modulation, commonly used for analog radio. + * - ``V4L2_BAND_MODULATION_VSB`` + - 0x02 + - Vestigial Sideband modulation, used for analog TV. + * - ``V4L2_BAND_MODULATION_FM`` + - 0x04 + - Frequency Modulation, commonly used for analog radio. + * - ``V4L2_BAND_MODULATION_AM`` + - 0x08 + - Amplitude Modulation, commonly used for analog radio. 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