Ok, after applying the home assistant yellow patches on top of the raspberry/linux 6.1 kernel (branch rpi-6.1.y), I was able to get the thermals back:
root@yellow:~# ls -lah /sys/class/thermal/thermal_zone0/
total 0
drwxr-xr-x 4 root root 0 May 29 23:57 .
drwxr-xr-x 3 root root 0 May 29 23:57 ..
drwxr-xr-x 3 root root 0 May 29 23:57 hwmon0
drwxr-xr-x 2 root root 0 May 30 00:05 power
lrwxrwxrwx 1 root root 0 May 29 23:57 subsystem -> ../../../../class/thermal
-r--r--r-- 1 root root 4.0K May 30 00:05 available_policies
-rw-r--r-- 1 root root 4.0K May 30 00:05 integral_cutoff
-rw-r--r-- 1 root root 4.0K May 30 00:05 k_d
-rw-r--r-- 1 root root 4.0K May 30 00:05 k_i
-rw-r--r-- 1 root root 4.0K May 30 00:05 k_po
-rw-r--r-- 1 root root 4.0K May 30 00:05 k_pu
-rw-r--r-- 1 root root 4.0K May 30 00:05 mode
-rw-r--r-- 1 root root 4.0K May 30 00:05 offset
-rw-r--r-- 1 root root 4.0K May 30 00:05 policy
-rw-r--r-- 1 root root 4.0K May 30 00:05 slope
-rw-r--r-- 1 root root 4.0K May 30 00:05 sustainable_power
-r--r--r-- 1 root root 4.0K May 30 00:05 temp
-rw-r--r-- 1 root root 4.0K May 30 00:05 trip_point_0_hyst
-r--r--r-- 1 root root 4.0K May 30 00:05 trip_point_0_temp
-r--r--r-- 1 root root 4.0K May 30 00:05 trip_point_0_type
-r--r--r-- 1 root root 4.0K May 30 00:05 type
-rw-r--r-- 1 root root 4.0K May 29 23:57 uevent
root@yellow:~# cat /sys/class/hwmon/hwmon0/temp1_input
55991
I created a gist, in case someone else wants to give it a try, until NabuCasa releases official 6.1 kernel support for the HA yellow:
One of the errors did not yet disappear tho:
[ 5.356090] i2c-mux-pinctrl soc:i2c0mux: Cannot look up pinctrl state i2c_csi_dsi: -19
EDIT: Updated the gist, now the error doesn’t show up anymore
Zigbee radio is working in Home Assistant, using device /dev/ttyAMA4
Note: I had to comment the “audio” label in bcm2711-rpi-cm4-ha-yellow.dts, I don’t know the side effect of doing so, but without that it wouldn’t build. I’m pretty sure something else will be broken, because the cm4 code from kernel 5 to 6 changed a bit. I guess NabuCasu will also need to do some refatoring, since they based the yellow dts on the cm4 dts.