arm64: dts: qcom: msm8916-longcheer-l8910: add rear camera support

[a-andre]

The camera should work out of the box with snapshot. (It might be necessary to install gst-plugins-good and libcamera-* manually.)

For megapixels the config file ~/.config/megapixels/config/longcheer,l8910.ini needs to be created:

[device]
make=BQ
model=X5

[rear]
driver=imx214
media-driver=qcom-camss
capture-width=1920
capture-height=1080
capture-rate=30
capture-fmt=RGGB10P
preview-width=1920
preview-height=1080
preview-rate=30
preview-fmt=RGGB10P
rotate=0
media-links=imx214:0->msm_csiphy0:0,msm_csiphy0:1->msm_csid0:0,msm_csid0:1->msm_ispif0:0,msm_ispif0:1->msm_vfe0_rdi0:0
mirrored=false

1920 and 1080 can also be replaced 4096 and 2304, respectively.

[TravMurav]

Amazing work! Are you planning to send these changes upstream?

[a-andre]

There is still an issue with the clock frequency, the clock frequency we set is not the clock frequency we get.

minecrell:

hm yeah now mclk is broken again
one would think that clk_set_rate(..., 23880597) results in 23880597 but nope!
clk_set_rate(..., 23880000) -> 23880597
clk_set_rate(..., 23880597) -> 66666666
clock-frequency = 23880000 + link-frequency 597014925 works, woo

Not sure, I think it would be good practice to use the actual value of clk_get_rate(), clk_set_rate() isn't guaranteed to set the requested rate exactly
so I guess we should either fix clk_set_rate(..., 23880597) to actually set 23880597
or just live with the slight confusion of clock-frequency vs link-frequency
probably former