i.MX6Q GPU usage with internal LDOs in bypass

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i.MX6Q GPU usage with internal LDOs in bypass

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paulschoenke
Contributor III

Hello i.MX6 Community!

I'm wondering if it is possible to put the i.MX6Q’s internal LDO requlators into bypass and still use the GPU?


If so, what is the correct configuration in the device tree?

Any feedback or input is welcomed and appreciated!

Thanks again!

Paul

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igorpadykov
NXP Employee
NXP Employee

Hi Paul

yes, below dts files are for bypas and ldo configuration,

imx6q-sabresd.dts imx6q-sabresd-ldo.dts

How to build Linux 3.10.17 for iMX6?

However board should support ldo bypass mode, as explained below

ENGR00276023-2: board: freescale: mx6q: add ldo bypass interface on b... - Gitorious

Best regards

igor

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jasonhaedt
Contributor III

Thank you for your feedback.  I have things working on the bypass but the GPU/VPU still give me errors.  Is this expected? 

My device tree:

&gpc {

fsl,ldo-bypass = <1>; /* use ldo-bypass, u-boot will check it and configure */

fsl,wdog-reset = <1>; /* watchdog select of reset source */

//pu-supply = <&reg_pu>; /* ldo-bypass:use pu_dummy if VDDSOC share with VDDPU */

pu-supply = <&pu_dummy>; /* ldo-bypass:use pu_dummy if VDDSOC share with VDDPU */

};

&cpu0 {

//arm-supply = <&reg_arm>;

//soc-supply = <&reg_soc>;

//pu-supply = <&reg_pu>; /* use pu_dummy if VDDSOC share with VDDPU */

arm-supply = <&sw1a_reg>;

soc-supply = <&sw1c_reg>;

pu-supply = <&pu_dummy>; /* use pu_dummy if VDDSOC share with VDDPU */

};

&vpu {

pu-supply = <&pu_dummy>;

//pu-supply = <&reg_pu>;

};

&gpu {

pu-supply = <&pu_dummy>;

//pu-supply = <&reg_pu>;

};

In U-boot I’ve also programmed the anatop module to put the regulators in bypass and setup the PFUZE100 PMIC for the correct voltages.

The board boots fine, but once we try to use the GPU and VPU, things go south from there. The GPU reports:

[galcore]: GPU[0] hang, automatic recovery.

So, how do I utilize the ldo-bypass mode and still get the GPU and VPU to function?

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igorpadykov
NXP Employee
NXP Employee

Hi Jason

what board and software are you using ?

Could you summarize it on new community thread and

give more details about board configuration ?

Thanks.

~igor

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jasonhaedt
Contributor III

We are using the latest Yocto release on the Sabre Board. 

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igorpadykov
NXP Employee
NXP Employee
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jasonhaedt
Contributor III

Yocto Dizzy

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igorpadykov
NXP Employee
NXP Employee

probably you know that it uses new gpu drivers  (like gpu-viv-bin-mx6q_3.10.31-1.1.0)

meta-fsl-arm/recipes-graphics/gpu-viv-bin-mx6q at master · Freescale/meta-fsl-arm · GitHub

Also I would post this to meta-fsl-arm mailing list, so that someone familiar with dizzy could try to assist you.

https://lists.yoctoproject.org/listinfo/meta-freescale

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