[meta-freescale] Setting VDD_SOC in i.MX6Q

[Teemu K]

Hi,

This is somewhat simple thing that turned out not to be so simple.

We have custom i.MX6Q based HW running Yocto 2.4 and Linux 4.1-2.0...
and VDDARM_IN is set to 1.425V. Also VDDSOC_IN is set to 1.425V. They
both come from external PMIC as usually do.

Now the VDD_SOC_CAP should be set to 1.375V without changing the
VDDARM_IN. I think this should be possible by setting the LDO_DIG(SOC)
to 1.375V.

That's the part that I couldn't figure out. I have following in device tree:
--
fsl,soc-operating-points = <
/* ARM kHz SOC-PU uV */
1200000 1375000
996000 1375000
852000 1375000
792000 1375000
396000 1375000

;

--

But that controls the PMIC and LDO. I just want to change the LDO
output (VDD_SOC_CAP). I only seem to be able to same both values not
just one.

Should that be possible and how to do it?

-TeemuK
--

[Teemu K]

Post by Teemu K
Hi,
This is somewhat simple thing that turned out not to be so simple.
We have custom i.MX6Q based HW running Yocto 2.4 and Linux 4.1-2.0...
and VDDARM_IN is set to 1.425V. Also VDDSOC_IN is set to 1.425V. They
both come from external PMIC as usually do.
Now the VDD_SOC_CAP should be set to 1.375V without changing the
VDDARM_IN. I think this should be possible by setting the LDO_DIG(SOC)
to 1.375V.
--
fsl,soc-operating-points = <
/* ARM kHz SOC-PU uV */
1200000 1375000
996000 1375000
852000 1375000
792000 1375000
396000 1375000

;

--
But that controls the PMIC and LDO. I just want to change the LDO
output (VDD_SOC_CAP). I only seem to be able to same both values not
just one.

Okay, so it seems I misunderstood the problem so replying to my own message.

I need to set PMIC voltages, not LDO so VDD_SOC_IN should be set to
1.375V, but leave the VDD_ARM_IN to 1.425V. The setup above changes
them both which is not desired.

Is there a way to configure just VDD_SOC_IN - part without modifying the driver?

-Teemu
--