On Fri, Oct 23, 2020 at 07:45:32PM +0200, Paul Kocialkowski wrote:

This series introduces support for MIPI CSI-2, with the A31 controller that is
found on most SoCs (A31, V3s and probably V5) as well as the A83T-specific
controller. While the former uses the same MIPI D-PHY that is already supported
for DSI, the latter embeds its own D-PHY.

In order to distinguish the use of the D-PHY between Rx mode (for MIPI CSI-2)
and Tx mode (for MIPI DSI), a submode is introduced for D-PHY in the PHY API.
This allows adding Rx support in the A31 D-PHY driver.

A few changes and fixes are applied to the A31 CSI controller driver, in order
to support the MIPI CSI-2 use-case.

Follows is the V4L2 device topology representing the interactions between
the MIPI CSI-2 sensor, the MIPI CSI-2 controller (which controls the D-PHY)
and the CSI controller:
- entity 1: sun6i-csi (1 pad, 1 link)
            type Node subtype V4L flags 0
            device node name /dev/video0
	pad0: Sink
		<- "sun6i-mipi-csi2":1 [ENABLED,IMMUTABLE]

- entity 5: sun6i-mipi-csi2 (2 pads, 2 links)
            type V4L2 subdev subtype Unknown flags 0
	pad0: Sink
		<- "ov5648 0-0036":0 [ENABLED,IMMUTABLE]
	pad1: Source
		-> "sun6i-csi":0 [ENABLED,IMMUTABLE]

- entity 8: ov5648 0-0036 (1 pad, 1 link)
            type V4L2 subdev subtype Sensor flags 0
            device node name /dev/v4l-subdev0
	pad0: Source
		[fmt:SBGGR8_1X8/640x480@1/30 field:none colorspace:raw xfer:none ycbcr:601 quantization:full-range]
		-> "sun6i-mipi-csi2":0 [ENABLED,IMMUTABLE]

Happy reviewing!

I mentioned it to Kevin in the first version, but you should have a
v4l2-compliance run here.

If you have some time, it would be great to run libcamera as well.

Maxime