Mity CPU Platforms » MityDSP-L138 (ARM9 Based Platforms)

03/27/2023

KN 02:12 PM Software Development: RE: Increasing CPU clock OMAPL138

Alright.
Is there is no way to change the default frequency from 300Mhz to e.g. 372MHz with U-Boot?
As far as I can see, according to *Table 6-5. Maximum Internal Clock Frequencies at Each Voltage Operating Point* in *OMAP-L138 C600... Kim Nielsen

MW 02:01 PM Software Development: RE: Increasing CPU clock OMAPL138

Hi Kim,
I think the issue is that the voltage scaling needs to be done to default
to a higher frequency.
The PMIC defaults the core voltage to support 300 MHz and I don't think
uBoot adjusts it -- it starts all the PLLs, etc., at... Michael Williamson

JC 02:00 PM Software Development: RE: Increasing CPU clock OMAPL138

I don't see an obvious default frequency config in the kernel, I'd guess that it stays with whatever frequency was setup by u-boot. But that would need to be tested.
You could use the ONDEMAND governor as default if you want it to sc... Jonathan Cormier

KN 01:44 PM Software Development: RE: Increasing CPU clock OMAPL138

I actually got another question.
By default, the cpu frequency seems to always be 300 MHz.
Is this value hardcoded in the kernel somewhere?
Can't seem to find it.
/Kim Kim Nielsen

03/24/2023

JC 05:24 PM Software Development: RE: Increasing CPU clock OMAPL138

Kim Nielsen wrote in message#6283:
> It's our own "experimental" kernel.
> ...
Gotcha, just curious if your based off of 4.19 from mainline or if you started from a TI kernel. Glad you got it working though. Jonathan Cormier

KN 12:21 PM Software Development: RE: Increasing CPU clock OMAPL138

It's our own "experimental" kernel.
It seems to be working now. The issue was that the pll0 registers were apparently locked by CFGCHIP0.
Thank you for your time.
/Kim Kim Nielsen

03/23/2023

JC 01:37 PM Software Development: RE: Increasing CPU clock OMAPL138

Where is the 4.19 kernel based from? It doesn't appear to have working cpufreq. Jonathan Cormier

KN 07:17 AM Software Development: RE: Increasing CPU clock OMAPL138

Hi Mike & Jonathan,
Thank you for the fast reply :-)
I have the following frequencies available according to the "scaling_available_frequencies" file.
456000 408000 372000 300000 200000 96000
We are actually using a newer kerne... Kim Nielsen

03/22/2023

JC 09:25 PM Software Development: RE: Increasing CPU clock OMAPL138

Hi Kim, What kernel version are you using? Testing this on our released 3.2 kernel appears to be working for me.
Note my module tested is only rated up to 372000khz. I can try to find a L138-F... module which should be good up to 45... Jonathan Cormier

MW 05:23 PM Software Development: RE: Increasing CPU clock OMAPL138

Hi Kim,
What do you get when you dump out the scaling_available_frequencies (I don't remember the exact name off the top of my head, but the file that lists the available frequencies that may be selected)?
-Mike
Michael Williamson

KN 03:14 PM Software Development: Increasing CPU clock OMAPL138

Hi,
I'm using a "L138-FI-236-RL" SOM board with SYS/BIOS running on the DSP and Linux on the ARM.
The Linux is built by ourselves, but it is based on davinci Linux.
I have attached the config file I use and dmesg log.
Issue:
I w... Kim Nielsen