Merge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull media documentation updates from Mauro Carvalho Chehab:
 "This patch series does the conversion of all media documentation stuff
  to Restrutured Text markup format and add them to the
  Documentation/index.rst file.

  The media documentation was grouped into 4 books:

    - media uAPI
    - media kAPI
    - V4L driver-specific documentation
    - DVB driver-specific documentation

  It also contains several documentation improvements and one fixup
  patch for a core issue with cropcap.

  PS.  After this patch series, the media DocBook is deprecated and
  should be removed.  I'll add such patch on a future pull request"

* tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (322 commits)
  [media] cx23885-cardlist.rst: add a new card
  [media] doc-rst: add some needed escape codes
  [media] doc-rst: kapi: use :c:func: instead of :cpp:func
  doc-rst: kernel-doc: fix a change introduced by mistake
  [media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops
  [media] dvb_ringbuffer.h: some documentation improvements
  [media] v4l2-ctrls.h: fully document the header file
  [media] doc-rst: Fix some typedef ugly warnings
  [media] doc-rst: reorganize the kAPI v4l2 chapters
  [media] rename v4l2-framework.rst to v4l2-intro.rst
  [media] move V4L2 clocks to a separate .rst file
  [media] v4l2-fh.rst: add cross references and markups
  [media] v4l2-fh.rst: add fh contents from v4l2-framework.rst
  [media] v4l2-fh.h: add documentation for it
  [media] v4l2-event.rst: add cross-references and markups
  [media] v4l2-event.h: document all functions
  [media] v4l2-event.rst: add text from v4l2-framework.rst
  [media] v4l2-framework.rst: remove videobuf quick chapter
  [media] v4l2-dev: add cross-references and improve markup
  [media] doc-rst: move v4l2-dev doc to a separate file
  ...

1 files changed, 52 insertions, 0 deletions

diff --git a/Documentation/media/uapi/v4l/dev-radio.rst b/Documentation/media/uapi/v4l/dev-radio.rst
new file mode 100644
index 000000000000..5ff7cded2591
--- /dev/null
+++ b/Documentation/media/uapi/v4l/dev-radio.rst
@@ -0,0 +1,52 @@
+.. -*- coding: utf-8; mode: rst -*-
+
+.. _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
+:ref:`v4l2_capability <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.