I have imx8mm on custom SOM and I'm running nxp uboot_imx(lf_v2022.04). Internal temperature sensor is not working as expected on multiple tested devices.
It displays only this string without actual temperature value:
CPU: Industrial temperature grade (-40C to 105C)
Uboot debugging showed that probably temperature value is out of range. (sensor range is 10-125). Return code of thermal_get_temp function (cpu.c) is -22(EINVAL).
I tried to read registers and the output is:
TMU_TSCR register value: 2147483657
TRITSR register value: 0
TSCR suggests that value is beyond range.
What can cause this issue?
解決済! 解決策の投稿を見る。
It turned out that I had wrong resistor value on TSENSOR_RES_EXT line. Solution was found on this old thread https://community.nxp.com/t5/i-MX-Processors/thermal-zone0-Resource-temporarily-unavailable/td-p/108....
I tried to confirm this but could not find this information in hardware design guidelines nor other imx8mm documentation.
It turned out that I had wrong resistor value on TSENSOR_RES_EXT line. Solution was found on this old thread https://community.nxp.com/t5/i-MX-Processors/thermal-zone0-Resource-temporarily-unavailable/td-p/108....
I tried to confirm this but could not find this information in hardware design guidelines nor other imx8mm documentation.