media: i2c: add driver for the SK Hynix Hi-846 8M pixel camera

The SK Hynix Hi-846 is a 1/4" 8M Pixel CMOS Image Sensor. It supports
usual features like I2C control, CSI-2 for frame data, digital/analog
gain control or test patterns.

This driver supports the 640x480, 1280x720 and 1632x1224 resolution
modes. It supports runtime PM in order not to draw any unnecessary power.

The part is also called YACG4D0C9SHC and a datasheet can be found at
https://product.skhynix.com/products/cis/cis.go

The large sets of partly undocumented register values are for example
found when searching for the hi846_mipi_raw_Sensor.c Android driver.

Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>

MAINTAINERS

@@ -8432,6 +8432,12 @@ S:	Maintained
 T:	git git://linuxtv.org/media_tree.git
 F:	drivers/media/i2c/hi556.c
 
+HYNIX HI846 SENSOR DRIVER
+M:	Martin Kepplinger <martin.kepplinger@puri.sm>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+F:	drivers/media/i2c/hi846.c
+
 Hyper-V/Azure CORE AND DRIVERS
 M:	"K. Y. Srinivasan" <kys@microsoft.com>
 M:	Haiyang Zhang <haiyangz@microsoft.com>

drivers/media/i2c/Kconfig

@@ -753,6 +753,19 @@ config VIDEO_IMX208
 	  To compile this driver as a module, choose M here: the
 	  module will be called imx208.
 
+config VIDEO_HI846
+	tristate "Hynix Hi-846 sensor support"
+	depends on I2C && VIDEO_V4L2
+	select MEDIA_CONTROLLER
+	select VIDEO_V4L2_SUBDEV_API
+	select V4L2_FWNODE
+	help
+	  This is a Video4Linux2 sensor driver for the Hynix
+	  Hi-846 camera.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hi846.
+
 config VIDEO_IMX214
 	tristate "Sony IMX214 sensor support"
 	depends on GPIOLIB && I2C && VIDEO_V4L2

drivers/media/i2c/Makefile

@@ -116,6 +116,7 @@ obj-$(CONFIG_VIDEO_ML86V7667)	+= ml86v7667.o
 obj-$(CONFIG_VIDEO_OV2659)	+= ov2659.o
 obj-$(CONFIG_VIDEO_TC358743)	+= tc358743.o
 obj-$(CONFIG_VIDEO_HI556)	+= hi556.o
+obj-$(CONFIG_VIDEO_HI846)	+= hi846.o
 obj-$(CONFIG_VIDEO_IMX208)	+= imx208.o
 obj-$(CONFIG_VIDEO_IMX214)	+= imx214.o
 obj-$(CONFIG_VIDEO_IMX219)	+= imx219.o