RK3576 Thermal ADC

Upstream is still missing support for the RK3576 thermal ADC, which is required to read temperature information for the CPU and GPU. Adding support should be as trivial as porting the following downstream patch and updating the DT binding + DT:

https://github.com/armbian/linux-rockchip/commit/d2e1994957e8c8cf01464eecaf1ccc46745695bf

added RK3576 label

Adding support should be as trivial as porting the following downstream patch and updating the DT binding + DT

It's a bit more than that, upstream doesn't have rk_tsadcv4_* yet. Will investigate.

EDIT: Nevermind I'm just blind, it is there, aside from rk_tsadcv4_tshut_mode.

Preliminary port lives in https://gitlab.collabora.com/hardware-enablement/rockchip-3588/linux/-/tree/rk3576-thermal-adc-2?ref_type=heads based on rk3588-test as of today.

Note: Haven't tested the changes yet as my board hasn't arrived yet.

Downstream does have some trim values for the tsadc stored in OTP judging by the device tree, but it doesn't seem like we have the OTP stuff in our DT yet so I omitted it for now.

mentioned in merge request !34 (closed)

V2 sent upstream: https://lore.kernel.org/linux-rockchip/20250225-rk3576-tsadc-upstream-v2-0-6eb7b00de89c@collabora.com/