Dne četrtek, 03. november 2022 ob 17:37:14 CET je Paul Kocialkowski napisal(a): > Some Allwinner platforms come with an Image Signal Processor, which > supports various features in order to enhance and transform data > received by image sensors into good-looking pictures. In most cases, > the data is raw bayer, which gets internally converted to RGB and > finally YUV, which is what the hardware produces. > > This driver supports ISPs that are similar to the A31 ISP, which was > the first standalone ISP found in Allwinner platforms. Simpler ISP > blocks were found in the A10 and A20, where they are tied to a CSI > controller. Newer generations of Allwinner SoCs (starting with the > H6, H616, etc) come with a new camera subsystem and revised ISP. > Even though these previous and next-generation ISPs are somewhat > similar to the A31 ISP, they have enough significant differences to > be out of the scope of this driver. > > While the ISP supports many features, including 3A and many > enhancement blocks, this implementation is limited to the following: > - V3s (V3/S3) platform support; > - Bayer media bus formats as input; > - Semi-planar YUV (NV12/NV21) as output; > - Debayering with per-component gain and offset configuration; > - 2D noise filtering with configurable coefficients. > > Since many features are missing from the associated uAPI, the driver > is aimed to integrate staging until all features are properly > described. > > On the technical side, it uses the v4l2 and media controller APIs, > with a video node for capture, a processor subdev and a video node > for parameters submission. A specific uAPI structure and associated > v4l2 meta format are used to configure parameters of the supported > modules. > > One particular thing about the hardware is that configuration for > module registers needs to be stored in a DMA buffer and gets copied > to actual registers by the hardware at the next vsync, when instructed > by a flag. This is handled by the "state" mechanism in the driver. > > Signed-off-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx> This is pretty complex piece of code, so I trust you that it's tested. Acked-by: Jernej Skrabec <jernej.skrabec@xxxxxxxxx> Best regards, Jernej
