This has been floating around out of tree, and the Pi Foundation is including a variant of it in the device tree overlay in its firmware update system.
Eric Anholt (3): dt-bindings: Add binding docs for V3D. drm/vc4: Recognize a more specific compatible string for V3D. ARM: bcm2835: Add VC4 to the device tree.
.../devicetree/bindings/display/brcm,bcm-vc4.txt | 12 ++++++ arch/arm/boot/dts/bcm2835-rpi-a-plus.dts | 4 ++ arch/arm/boot/dts/bcm2835-rpi-a.dts | 4 ++ arch/arm/boot/dts/bcm2835-rpi-b-plus.dts | 4 ++ arch/arm/boot/dts/bcm2835-rpi-b-rev2.dts | 4 ++ arch/arm/boot/dts/bcm2835-rpi-b.dts | 4 ++ arch/arm/boot/dts/bcm2835-rpi.dtsi | 9 +++++ arch/arm/boot/dts/bcm2836-rpi-2-b.dts | 4 ++ arch/arm/boot/dts/bcm283x.dtsi | 47 ++++++++++++++++++++++ drivers/gpu/drm/vc4/vc4_v3d.c | 1 + 10 files changed, 93 insertions(+)