Draft: Use mainline camera drivers

Fixes #289 (closed) Fixes https://source.puri.sm/Librem5/linux-next/-/issues/339

this switches our whole camera driver stack to use as much mainline drivers as possible.

this MR will be part of all pureos/5.15* releases automatically too

how to test:

selfie cam

#!/bin/bash
WIDTH=1632
HEIGHT=1224
SKIP=10

media-ctl -d "platform:30a90000.csi" --set-v4l2 "'csi':0 [fmt:SGBRG10/${WIDTH}x${HEIGHT} colorspace:raw]"
media-ctl -d "platform:30a90000.csi" --set-v4l2 "'imx8mq-mipi-csi2 30a70000.csi':0 [fmt:SGBRG10/${WIDTH}x${HEIGHT} colorspace:raw]"
media-ctl -d "platform:30a90000.csi" --set-v4l2 "'hi846 2-0020':0 [fmt:SGBRG10/${WIDTH}x${HEIGHT} colorspace:raw]"
media-ctl -d "platform:30a90000.csi" -l "'hi846 2-0020':0 -> 'imx8mq-mipi-csi2 30a70000.csi':0 [1]"
v4l2-ctl -d "/dev/v4l/by-path/platform-30a90000.csi-video-index0" --set-fmt-video=width=${WIDTH},height=${HEIGHT},pixelformat=GB16 --stream-mmap --stream-to=$WIDTH.raw --stream-skip=$SKIP --stream-count=1
./debayer10.py $WIDTH.raw $WIDTH $HEIGHT $WIDTH.png

rear cam

#!/bin/bash
WIDTH=1052
HEIGHT=780
SKIP=10

media-ctl -d "platform:30b80000.csi" --set-v4l2 "'csi':0 [fmt:SGRBG8/${WIDTH}x${HEIGHT} colorspace:raw]"
media-ctl -d "platform:30b80000.csi" --set-v4l2 "'imx8mq-mipi-csi2 30b60000.csi':0 [fmt:SGRBG8/${WIDTH}x${HEIGHT} colorspace:raw]"
media-ctl -d "platform:30b80000.csi" --set-v4l2 "'s5k3l6xx 3-002d':0 [fmt:SGRBG8/${WIDTH}x${HEIGHT} colorspace:raw]"
media-ctl -d "platform:30b80000.csi" -l "'s5k3l6xx 3-002d':0 -> 'imx8mq-mipi-csi2 30b60000.csi':0 [1]"
v4l2-ctl -d "/dev/v4l/by-path/platform-30b80000.csi-video-index0" --set-fmt-video=width=${WIDTH},height=${HEIGHT},pixelformat=GRBG --stream-mmap --stream-to=$WIDTH.raw --stream-skip=$SKIP --stream-count=1

for the devkit (this MR configures a different sensor driver for it) I haven't tested much, but this can be a starting point:

#!/bin/bash
WIDTH=640
HEIGHT=480
SKIP=10

media-ctl -d "platform:30a90000.csi" --set-v4l2 "'csi':0 [fmt:UYVY8_2X8/${WIDTH}x${HEIGHT} colorspace:srgb]"
media-ctl -d "platform:30a90000.csi" --set-v4l2 "'imx8mq-mipi-csi2 30a70000.csi':0 [fmt:UYVY8_2X8/${WIDTH}x${HEIGHT} colorspace:srgb]"
media-ctl -d "platform:30a90000.csi" --set-v4l2 "'ov5640 2-003c':0 [fmt:UYVY8_2X8/${WIDTH}x${HEIGHT} colorspace:srgb]"
# setup by drivers
#media-ctl -d "platform:30a90000.csi" -l "'hi846 2-0020':0 -> 'imx8mq-mipi-csi2 30a70000.csi':0 [1]"
v4l2-ctl -d "/dev/v4l/by-path/platform-30a90000.csi-video-index0" --set-fmt-video=width=${WIDTH},height=${HEIGHT},pixelformat=UYVY --stream-mmap --stream-to=$WIDTH.raw --stream-skip=$SKIP --stream-count=1

• doesn't start streaming yet and before and after it's stopped, it shows:

[  505.078647] v4l2_get_link_freq: Link frequency estimated using pixel rate: result might be inaccurate
[  505.078664] v4l2_get_link_freq: Consider implementing support for V4L2_CID_LINK_FREQ in the transmitter driver
[  505.078673] imx8mq-mipi-csi2 30a70000.csi: esc clk rate: 66666667
[  505.078686] imx8mq-mipi-csi2 30a70000.csi: lane rate 491443200 Ths_settle 128 hs_settle 8

for the devkit camera, we have https://source.puri.sm/Librem5/linux-next/-/issues/35

we want to have a patch for megapixels so that it works with these drivers, see https://source.puri.sm/Librem5/megapixels/-/issues/13 and this MR should help developing that. (A megapixels .ini file that only includes the seflie cam would be OK for first tests).

but for merging this, we need

• a working (streaming) big-cam with this (and the currect old CSI stack too) -> almost there.
• know how controls are used and a working megapixels patchset that works with this
• a working devkit cam with the new drivers(nice to have at least) or create an issue for that