diff options
Diffstat (limited to 'Documentation/media/uapi/v4l/dev-radio.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/dev-radio.rst | 59 |
1 files changed, 0 insertions, 59 deletions
diff --git a/Documentation/media/uapi/v4l/dev-radio.rst b/Documentation/media/uapi/v4l/dev-radio.rst deleted file mode 100644 index 133eb0e788c2..000000000000 --- a/Documentation/media/uapi/v4l/dev-radio.rst +++ /dev/null @@ -1,59 +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 - -.. _radio: - -*************** -Radio Interface -*************** - -This interface is intended for AM and FM (analog) radio receivers and -transmitters. - -Conventionally V4L2 radio devices are accessed through character device -special files named ``/dev/radio`` and ``/dev/radio0`` to -``/dev/radio63`` with major number 81 and minor numbers 64 to 127. - - -Querying Capabilities -===================== - -Devices supporting the radio interface set the ``V4L2_CAP_RADIO`` and -``V4L2_CAP_TUNER`` or ``V4L2_CAP_MODULATOR`` flag in the -``capabilities`` field of struct -:c:type:`v4l2_capability` returned by the -:ref:`VIDIOC_QUERYCAP` ioctl. Other combinations of -capability flags are reserved for future extensions. - - -Supplemental Functions -====================== - -Radio devices can support :ref:`controls <control>`, and must support -the :ref:`tuner or modulator <tuner>` ioctls. - -They do not support the video input or output, audio input or output, -video standard, cropping and scaling, compression and streaming -parameter, or overlay ioctls. All other ioctls and I/O methods are -reserved for future extensions. - - -Programming -=========== - -Radio devices may have a couple audio controls (as discussed in -:ref:`control`) such as a volume control, possibly custom controls. -Further all radio devices have one tuner or modulator (these are -discussed in :ref:`tuner`) with index number zero to select the radio -frequency and to determine if a monaural or FM stereo program is -received/emitted. Drivers switch automatically between AM and FM -depending on the selected frequency. The -:ref:`VIDIOC_G_TUNER <VIDIOC_G_TUNER>` or -:ref:`VIDIOC_G_MODULATOR <VIDIOC_G_MODULATOR>` ioctl reports the -supported frequency range. |