Merge tag 'media/v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media

Pull media updates from Mauro Carvalho Chehab:

 - Media documentation is now split into admin-guide, driver-api and
   userspace-api books (a longstanding request from Jon);

 - The media Kconfig was reorganized, in order to make easier to select
   drivers and their dependencies;

 - The testing drivers now has a separate directory;

 - added a new driver for Rockchip Video Decoder IP;

 - The atomisp staging driver was resurrected. It is meant to work with
   4 generations of cameras on Atom-based laptops, tablets and cell
   phones. So, it seems worth investing time to cleanup this driver and
   making it in good shape.

 - Added some V4L2 core ancillary routines to help with h264 codecs;

 - Added an ov2740 image sensor driver;

 - The si2157 gained support for Analog TV, which, in turn, added
   support for some cx231xx and cx23885 boards to also support analog
   standards;

 - Added some V4L2 controls (V4L2_CID_CAMERA_ORIENTATION and
   V4L2_CID_CAMERA_SENSOR_ROTATION) to help identifying where the camera
   is located at the device;

 - VIDIOC_ENUM_FMT was extended to support MC-centric devices;

 - Lots of drivers improvements and cleanups.

* tag 'media/v5.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (503 commits)
  media: Documentation: media: Refer to mbus format documentation from CSI-2 docs
  media: s5k5baf: Replace zero-length array with flexible-array
  media: i2c: imx219: Drop <linux/clk-provider.h> and <linux/clkdev.h>
  media: i2c: Add ov2740 image sensor driver
  media: ov8856: Implement sensor module revision identification
  media: ov8856: Add devicetree support
  media: dt-bindings: ov8856: Document YAML bindings
  media: dvb-usb: Add Cinergy S2 PCIe Dual Port support
  media: dvbdev: Fix tuner->demod media controller link
  media: dt-bindings: phy: phy-rockchip-dphy-rx0: move rockchip dphy rx0 bindings out of staging
  media: staging: dt-bindings: phy-rockchip-dphy-rx0: remove non-used reg property
  media: atomisp: unify the version for isp2401 a0 and b0 versions
  media: atomisp: update TODO with the current data
  media: atomisp: adjust some code at sh_css that could be broken
  media: atomisp: don't produce errs for ignored IRQs
  media: atomisp: print IRQ when debugging
  media: atomisp: isp_mmu: don't use kmem_cache
  media: atomisp: add a notice about possible leak resources
  media: atomisp: disable the dynamic and reserved pools
  media: atomisp: turn on camera before setting it
  ...

1 files changed, 114 insertions, 0 deletions

diff --git a/Documentation/userspace-api/media/v4l/dev-sdr.rst b/Documentation/userspace-api/media/v4l/dev-sdr.rst
new file mode 100644
index 000000000000..c9563bca444e
--- /dev/null
+++ b/Documentation/userspace-api/media/v4l/dev-sdr.rst
@@ -0,0 +1,114 @@
+.. 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/userspace-api/media/fdl-appendix.rst.
+..
+.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections
+
+.. _sdr:
+
+**************************************
+Software Defined Radio Interface (SDR)
+**************************************
+
+SDR is an abbreviation of Software Defined Radio, the radio device which
+uses application software for modulation or demodulation. This interface
+is intended for controlling and data streaming of such devices.
+
+SDR devices are accessed through character device special files named
+``/dev/swradio0`` to ``/dev/swradio255`` with major number 81 and
+dynamically allocated minor numbers 0 to 255.
+
+
+Querying Capabilities
+=====================
+
+Devices supporting the SDR receiver interface set the
+``V4L2_CAP_SDR_CAPTURE`` and ``V4L2_CAP_TUNER`` flag in the
+``capabilities`` field of struct
+:c:type:`v4l2_capability` returned by the
+:ref:`VIDIOC_QUERYCAP` ioctl. That flag means the
+device has an Analog to Digital Converter (ADC), which is a mandatory
+element for the SDR receiver.
+
+Devices supporting the SDR transmitter interface set the
+``V4L2_CAP_SDR_OUTPUT`` and ``V4L2_CAP_MODULATOR`` flag in the
+``capabilities`` field of struct
+:c:type:`v4l2_capability` returned by the
+:ref:`VIDIOC_QUERYCAP` ioctl. That flag means the
+device has an Digital to Analog Converter (DAC), which is a mandatory
+element for the SDR transmitter.
+
+At least one of the read/write, streaming or asynchronous I/O methods
+must be supported.
+
+
+Supplemental Functions
+======================
+
+SDR devices can support :ref:`controls <control>`, and must support
+the :ref:`tuner` ioctls. Tuner ioctls are used for setting the
+ADC/DAC sampling rate (sampling frequency) and the possible radio
+frequency (RF).
+
+The ``V4L2_TUNER_SDR`` tuner type is used for setting SDR device ADC/DAC
+frequency, and the ``V4L2_TUNER_RF`` tuner type is used for setting
+radio frequency. The tuner index of the RF tuner (if any) must always
+follow the SDR tuner index. Normally the SDR tuner is #0 and the RF
+tuner is #1.
+
+The :ref:`VIDIOC_S_HW_FREQ_SEEK` ioctl is
+not supported.
+
+
+Data Format Negotiation
+=======================
+
+The SDR device uses the :ref:`format` ioctls to select the
+capture and output format. Both the sampling resolution and the data
+streaming format are bound to that selectable format. In addition to the
+basic :ref:`format` ioctls, the
+:ref:`VIDIOC_ENUM_FMT` ioctl must be supported as
+well.
+
+To use the :ref:`format` ioctls applications set the ``type``
+field of a struct :c:type:`v4l2_format` to
+``V4L2_BUF_TYPE_SDR_CAPTURE`` or ``V4L2_BUF_TYPE_SDR_OUTPUT`` and use
+the struct :c:type:`v4l2_sdr_format` ``sdr`` member
+of the ``fmt`` union as needed per the desired operation. Currently
+there is two fields, ``pixelformat`` and ``buffersize``, of struct
+struct :c:type:`v4l2_sdr_format` which are used.
+Content of the ``pixelformat`` is V4L2 FourCC code of the data format.
+The ``buffersize`` field is maximum buffer size in bytes required for
+data transfer, set by the driver in order to inform application.
+
+
+.. c:type:: v4l2_sdr_format
+
+.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
+
+.. flat-table:: struct v4l2_sdr_format
+    :header-rows:  0
+    :stub-columns: 0
+    :widths:       1 1 2
+
+    * - __u32
+      - ``pixelformat``
+      - The data format or type of compression, set by the application.
+	This is a little endian
+	:ref:`four character code <v4l2-fourcc>`. V4L2 defines SDR
+	formats in :ref:`sdr-formats`.
+    * - __u32
+      - ``buffersize``
+      - Maximum size in bytes required for data. Value is set by the
+	driver.
+    * - __u8
+      - ``reserved[24]``
+      - This array is reserved for future extensions. Drivers and
+	applications must set it to zero.
+
+
+An SDR device may support :ref:`read/write <rw>` and/or streaming
+(:ref:`memory mapping <mmap>` or :ref:`user pointer <userp>`) I/O.