Enabling TPM on A core imx8ulp

[wendy-liu]

Hi @Chavira

     I'm using iMX8ULP-evk to enable TPM in A core according to your article: https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/How-to-use-PWM-on-iMX93-EVK-board/ta-p/1... 

    I chose PTF19 (J20 pin3) to generate PWM signal.

     After flashing, I open a terminal and execute the following commands:

cd /sys/class/pwm/pwmchip0;
echo 0 > export;
cd pwm0;
echo 400000 > period;
echo 200000 > duty_cycle;
echo 1 > enable;

    Then , I use oscilloscope to measure it waveform , and it keeps outputting a high-level signal.

    Could you give me some advice?

    My dts ,config, log are as below.

Best Regard!

[wendy-liu]

@Chavira 

Also, tpm_rpchip_0 is the node(/sys/class/pwm/pwmchip0/), but where is tpm5?

And, which TPM does tpm_rpchip_0 control?

There are some questions I would like to ask you.Hope your reply!Thanks a lot!

[Chavira]

HI @wendy-liu!
Thank you for contacting NXP Support!

I will start with the research of this issue.

It looks like the TPM only can be managed by M core and you can control the TPM module using rpmsg only.

I will give you an update as soon as possible.

Best Regards!

Chavira

[wendy-liu]

@Chavira 

Looking forward your reply!

Thank you very much!

[Chavira · Accepted solution]

Hi @wendy-liu!

Try changing the driver from "fsl,imx7ulp-tpm" to "fsl,imx7ulp-pwm" in imx8ulp.dtsi.

tpm5: tpm@29340000 {
      compatible = "fsl,imx8ulp-tpm", "fsl,imx7ulp-pwm";

Additional you should disable the LPSPI5 since the LPSPI5 is using the pin PTF19.

Best Regards!]

Chavira

[wendy-liu]

Thanks! I have been solved!

Best Regards!