From: Philipp Zabel <p.zabel@pengutronix.de>

This driver can handle SoC internal and external video bus multiplexers,
controlled either by register bit fields or by a GPIO. The subdevice
passes through frame interval and mbus configuration of the active input
to the output side.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

--

- fixed a cut&paste error in vidsw_remove(): v4l2_async_register_subdev()
  should be unregister.

- added media_entity_cleanup() and v4l2_device_unregister_subdev()
  to vidsw_remove().

- there was a line left over from a previous iteration that negated
  the new way of determining the pad count just before it which
  has been removed (num_pads = of_get_child_count(np)).

- Philipp Zabel has developed a set of patches that allow adding
  to the subdev async notifier waiting list using a chaining method
  from the async registered callbacks (v4l2_of_subdev_registered()
  and the prep patches for that). For now, I've removed the use of
  v4l2_of_subdev_registered() for the vidmux driver's registered
  callback. This doesn't affect the functionality of this driver,
  but allows for it to be merged now, before adding the chaining
  support.

Signed-off-by: Steve Longerbeam <redacted>
---
 .../bindings/media/video-multiplexer.txt           |  59 +++
 drivers/media/platform/Kconfig                     |   8 +
 drivers/media/platform/Makefile                    |   2 +
 drivers/media/platform/video-multiplexer.c         | 472 +++++++++++++++++++++
 4 files changed, 541 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/video-multiplexer.txt
 create mode 100644 drivers/media/platform/video-multiplexer.c

diff --git a/Documentation/devicetree/bindings/media/video-multiplexer.txt b/Documentation/devicetree/bindings/media/video-multiplexer.txt
new file mode 100644
index 0000000..9d133d9
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/video-multiplexer.txt

@@ -0,0 +1,59 @@
+Video Multiplexer
+=================
+
+Video multiplexers allow to select between multiple input ports. Video received
+on the active input port is passed through to the output port. Muxes described
+by this binding may be controlled by a syscon register bitfield or by a GPIO.
+
+Required properties:
+- compatible : should be "video-multiplexer"