media: staging: max96712: Add basic support for MAX96712 GMSL2 deserializer

Add basic support for Maxim MAX96712 quad GMSL2 deserializers. The
driver is capable of powering on the device and configuring the MIPI
CSI-2 bus in a DPHY 4-lane configuration as well as operating the
internal VTG (Video Timing Generator) and VPG (Video Pattern Generator).

Using these features the driver is able to act as a 1080p @ 30 fps V4L2
video source. Producing either a checkerboard or gradient pattern on the
CSI-2 bus, selectable thru a V4L2 control.

While the driver is useful as-is and have been used to prove the correct
operation of the MAX96712 itself and "downstream" devices using the
MAX96712 as a video source there are a lot of features missing. Most
notably the ability to operate the GMSL bus.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

Author: Niklas Söderlund

MAINTAINERS

@@ -11523,6 +11523,12 @@ S:	Maintained
 F:	Documentation/devicetree/bindings/media/i2c/maxim,max9286.yaml
 F:	drivers/media/i2c/max9286.c
 
+MAX96712 QUAD GMSL2 DESERIALIZER DRIVER
+M:	Niklas Söderlund <niklas.soderlund@ragnatech.se>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	drivers/staging/media/max96712/max96712.c
+
 MAX9860 MONO AUDIO VOICE CODEC DRIVER
 M:	Peter Rosin <peda@axentia.se>
 L:	alsa-devel@alsa-project.org (moderated for non-subscribers)

drivers/staging/media/Kconfig

@@ -26,6 +26,8 @@ source "drivers/staging/media/hantro/Kconfig"
 
 source "drivers/staging/media/imx/Kconfig"
 
+source "drivers/staging/media/max96712/Kconfig"
+
 source "drivers/staging/media/meson/vdec/Kconfig"
 
 source "drivers/staging/media/omap4iss/Kconfig"

drivers/staging/media/Makefile

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_INTEL_ATOMISP)     += atomisp/
 obj-$(CONFIG_VIDEO_IMX_MEDIA)	+= imx/
+obj-$(CONFIG_VIDEO_MAX96712)	+= max96712/
 obj-$(CONFIG_VIDEO_MESON_VDEC)	+= meson/vdec/
 obj-$(CONFIG_VIDEO_OMAP4)	+= omap4iss/
 obj-$(CONFIG_VIDEO_ROCKCHIP_VDEC)	+= rkvdec/

drivers/staging/media/max96712/Kconfig

@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+config VIDEO_MAX96712
+	tristate "Maxim MAX96712 Quad GMSL2 Deserializer support"
+	depends on I2C
+	depends on OF_GPIO
+	select V4L2_FWNODE
+	select VIDEO_V4L2_SUBDEV_API
+	select MEDIA_CONTROLLER
+	help
+	  This driver supports the Maxim MAX96712 Quad GMSL2 Deserializer.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called max96712.

drivers/staging/media/max96712/Makefile

@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0
+obj-$(CONFIG_VIDEO_MAX96712) += max96712.o