PowerQUICC ProcessorsのトピックMPC8640 MPIC TIMER Test

MPC8640 MPIC TIMER Test

ranjithkumarv — Thu, 12 Nov 2020 04:49:27 GMT

Hi i have ported linux kernel 3.6.11 on mpc8640 based custom board.

I added support for mpic-timer support in kernel and dts file.But after booting the linux i am not able to see any timer device.

My Platform Clock-400MHz,MPIC at 50MHz(1/8 Platform Clock)

I want to test the timer with 1us resolution.

Can anyone tell me how to test MPIC Timer and any test code will be very helpful.

Thanks in advance.

Re: MPC8640 MPIC TIMER Test

yipingwang — Wed, 18 Nov 2020 06:42:37 GMT

NXP's mpic-timer has not been supported by Linux until 2013, so it's unavailable in Linux 3.6.11. You can either upgrade your kernel or backport the mpic-timer patches:

https://patchwork.ozlabs.org/project/linuxppc-dev/patch/1365474152-21524-2-git-send-email-dongsheng.wang@freescale.com/

https://lists.ozlabs.org/pipermail/linuxppc-dev/2013-March/104326.html

If you choose to backport you may need to check if more patches are required.

Re: MPC8640 MPIC TIMER Test

ranjithkumarv — Tue, 24 Nov 2020 11:27:33 GMT

@yipingwang

Thanks for your reply.

I have already done the steps given in the links you mentioned but still facing some issue in getting the timer up.

Enabled the MPIC TIMER support in kernel.

While kernel booting i am getting the following message

/soc8641@d0000000/timer@41100: cannot get timer frequency.

/soc8641@d0000000/timer@42100: cannot get timer frequency.

Here i am attaching the dts file of my board and System Bootlog.

Am i missing something?Kindly give some suggestion on this.

Thanks & Regards,

Ranjithkumar

Please try to set clock-frequency for mpic a valid value instead of 0.Re: MPC8640 MPIC TIMER Test

yipingwang — Tue, 01 Dec 2020 03:08:01 GMT

Please try to set clock-frequency for mpic a valid value instead of 0.

Re: Please try to set clock-frequency for mpic a valid value instead of 0.Re: MPC8640 MPIC TIMER Tes

ranjithkumarv — Thu, 03 Dec 2020 06:57:10 GMT

Hi @yipingwang

Thanks for your reply.

I modified the clock frequency to a valid value and after that it is not showing the following error at the time of kernel boot.

/soc8641@d0000000/timer@41100: cannot get timer frequency.

/soc8641@d0000000/timer@42100: cannot get timer frequency.

Now can you suggest how to access the timer from linux.

Thanks in Advance,

Ranjithkumar.V

Re: Please try to set clock-frequency for mpic a valid value instead of 0.Re: MPC8640 MPIC TIMER Tes

yipingwang — Fri, 04 Dec 2020 03:16:41 GMT

There is an example of how to verify MPIC timer in this patch: https://lists.ozlabs.org/pipermail/linuxppc-dev/2013-March/104326.html