media: v4l: cadence: Add Cadence MIPI-CSI2 RX driver

The Cadence CSI-2 RX Controller is an hardware block meant to be used as a
bridge between a CSI-2 bus and pixel grabbers.

It supports operating with internal or external D-PHY, with up to 4 lanes,
or without any D-PHY. The current code only supports the latter case.

It also support dynamic mapping of the CSI-2 virtual channels to the
associated pixel grabbers, but that isn't allowed at the moment either.
Acked-by: Benoit Parrot <bparrot@ti.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

MAINTAINERS

@@ -3136,6 +3136,13 @@ S:	Supported
 F:	Documentation/filesystems/caching/cachefiles.txt
 F:	fs/cachefiles/
 
+CADENCE MIPI-CSI2 BRIDGES
+M:	Maxime Ripard <maxime.ripard@bootlin.com>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	Documentation/devicetree/bindings/media/cdns,*.txt
+F:	drivers/media/platform/cadence/cdns-csi2*
+
 CADET FM/AM RADIO RECEIVER DRIVER
 M:	Hans Verkuil <hverkuil@xs4all.nl>
 L:	linux-media@vger.kernel.org

drivers/media/platform/Kconfig

@@ -26,6 +26,7 @@ config VIDEO_VIA_CAMERA
 #
 # Platform multimedia device configuration
 #
+source "drivers/media/platform/cadence/Kconfig"
 
 source "drivers/media/platform/davinci/Kconfig"
 

drivers/media/platform/Makefile

@@ -3,6 +3,7 @@
 # Makefile for the video capture/playback device drivers.
 #
 
+obj-$(CONFIG_VIDEO_CADENCE)		+= cadence/
 obj-$(CONFIG_VIDEO_VIA_CAMERA) += via-camera.o
 obj-$(CONFIG_VIDEO_CAFE_CCIC) += marvell-ccic/
 obj-$(CONFIG_VIDEO_MMP_CAMERA) += marvell-ccic/

drivers/media/platform/cadence/Kconfig

+config VIDEO_CADENCE
+	bool "Cadence Video Devices"
+	help
+	  If you have a media device designed by Cadence, say Y.
+
+	  Note that this option doesn't include new drivers in the kernel:
+	  saying N will just cause Kconfig to skip all the questions about
+	  Cadence media devices.
+
+if VIDEO_CADENCE
+
+config VIDEO_CADENCE_CSI2RX
+	tristate "Cadence MIPI-CSI2 RX Controller"
+	depends on MEDIA_CONTROLLER
+	depends on VIDEO_V4L2_SUBDEV_API
+	select V4L2_FWNODE
+	help
+	  Support for the Cadence MIPI CSI2 Receiver controller.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called cdns-csi2rx.
+
+endif

drivers/media/platform/cadence/Makefile

+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_VIDEO_CADENCE_CSI2RX)	+= cdns-csi2rx.o