staging: vc04_services: bcm2835-camera: Add back the downstream driver

Signed-off-by: Dave Stevenson <[email protected]>

Author: popcornmix

drivers/platform/raspberrypi/vchiq-mmal/mmal-parameters.h

@@ -368,6 +368,7 @@ enum mmal_parameter_awbmode {
 	MMAL_PARAM_AWBMODE_INCANDESCENT,
 	MMAL_PARAM_AWBMODE_FLASH,
 	MMAL_PARAM_AWBMODE_HORIZON,
+	MMAL_PARAM_AWBMODE_GREYWORLD,
 };
 
 enum mmal_parameter_imagefx {

drivers/staging/vc04_services/Kconfig

@@ -2,6 +2,7 @@
 if BCM_VIDEOCORE
 
 source "drivers/staging/vc04_services/bcm2835-audio/Kconfig"
+source "drivers/staging/vc04_services/bcm2835-camera/Kconfig"
 
 endif
 

drivers/staging/vc04_services/Makefile

@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_SND_BCM2835)		+= bcm2835-audio/
+obj-$(CONFIG_VIDEO_BCM2835)		+= bcm2835-camera/
 

drivers/staging/vc04_services/bcm2835-camera/Kconfig

@@ -0,0 +1,13 @@
+# SPDX-License-Identifier: GPL-2.0
+config VIDEO_BCM2835
+	tristate "BCM2835 Camera"
+	depends on MEDIA_SUPPORT
+	depends on VIDEO_DEV && (ARCH_BCM2835 || COMPILE_TEST)
+	select BCM2835_VCHIQ if HAS_DMA
+	select BCM2835_VCHIQ_MMAL if HAS_DMA
+	select VIDEOBUF2_VMALLOC
+	select BTREE
+	help
+	  Say Y here to enable camera host interface devices for
+	  Broadcom BCM2835 SoC. This operates over the VCHIQ interface
+	  to a service running on VideoCore.

drivers/staging/vc04_services/bcm2835-camera/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0
+bcm2835-v4l2-$(CONFIG_VIDEO_BCM2835) := \
+	bcm2835-camera.o \
+	controls.o
+
+obj-$(CONFIG_VIDEO_BCM2835) += bcm2835-v4l2.o

drivers/staging/vc04_services/bcm2835-camera/TODO

@@ -0,0 +1,17 @@
+1) Support dma-buf memory management.
+
+In order to zero-copy import camera images into the 3D or display
+pipelines, we need to export our buffers through dma-buf so that the
+vc4 driver can import them.  This may involve bringing in the VCSM
+driver (which allows long-term management of regions of memory in the
+space that the VPU reserved and Linux otherwise doesn't have access
+to), or building some new protocol that allows VCSM-style management
+of Linux's CMA memory.
+
+2) Avoid extra copies for padding of images.
+
+We expose V4L2_PIX_FMT_* formats that have a specified stride/height
+padding in the V4L2 spec, but that padding doesn't match what the
+hardware can do.  If we exposed the native padding requirements
+through the V4L2 "multiplanar" formats, the firmware would have one
+less copy it needed to do.