Embedded Intel® Core™ Processors
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Unable to change values of GPIOs

Suchitra
Novice
327 Views

Hi,

 

We are using the Intel Andersenlake yocto build environment for building image for our Intel Xeon processor. Our PCH version is C624 which is used with Xeon processor.

 

We are using sysfs to read the values of the GPIO pins and we are getting the accurate value at the present time. The issue comes when we want to write into the pin value. The pin value remains same even after changing the value.

 

Detailed Example:

Step-1: export pin 355 success

              echo 355 > /sys/class/gpio/export

Step-2: set the direction as out also success

              echo "out" > /sys/class/gpio/gpio355/direction

Step-3: change the value from "LOW" (0) to "HIGH" (1) fails without any warning or error

              echo 1 > /sys/class/gpio/gpio355/value

 

I performed the same steps for reading the values by setting the direction as "in" and able to read the correct value but the issue appeared while writing the value. These pins are connected from PCH to external circuitry. 

 

Is there anything we are missing from the yocto build or our procedure ?

 

Hardware:

Processor: Intel Xeon
PCH: version C624

 

Thanks 

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2 Replies
Jaime_Lizarme
Moderator
315 Views

Hello Suchitra

 

Thank you for contacting Intel Embedded Community.

 

In order to help you with your Yocto question as a reference please address it to the channels listed at the following website:

 

https://www.yoctoproject.org/tools-resources/community/mailing-lists https://www.yoctoproject.org/tools-resources/community/mailing-lists

 

The previous suggestion is based on the following blue highlighted information stated in some of the Intel product brief documents:

 

 

We hope that this information may help you.

 

Best regards,

Jaime L.

Suchitra
Novice
272 Views

Hi Jamie,

 

Thank you for providing Yocto reference link.

We have posted our query over Yocto community since week ago. Still we are not able to get any response from there.

Any prior help from your side would be much appreciated.

 

Thank you. 

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