I2c access in the UEFI shell

[bkingsbury]

I need to develop code to access I2C devices from an i7 procesasor. I am attempting to access the I2c bus from efi code that runs from the UEFI shell. This is on an adlink cExpress-wl module with a 8th Gen Intel® Core™ i7-8665UE . I am looking for the low level UEFI code to access the I2c over the PHC.

Thanks

Brian 

[Maria_R_Intel]

Hello bkingsbury,

Thank you for posting on the Intel* Community.

We are currently checking your request internally to provide you with the most accurate support, please expect an update soon.

Best regards,

Maria R.

Intel Customer Support Technician

[Maria_R_Intel]

Hello bkingsbury,

Thank you for patiently waiting, after reviewing your request internally we have two suggestions for you to get the appropriate support:

The Gen Intel® Core™ i7-8665UE processor is embedded, we have a forum for those specific products and questions so we are moving it to the Embedded Intel® Core™ Processors forum so it can get answered more quickly.

Also, usually, I2c bus questions came from customers using FPGA platforms so if this is the case, feel free to post in the FPGA community: https://community.intel.com/t5/Programmable-Devices/bd-p/programmable-devices?profile.language=en

Please, expect a response soon.

Best regards, 

Maria R.  

Intel Customer Support Technician 

[CarlosAM_INTEL]

Hello, @bkingsbury:

Thank you for contacting Intel Embedded Community.

Your consultations related to the third-party implementation should be addressed as a reference through the channel listed on the following website:

https://www.adlinktech.com/en/Askanexpert

Best regards,

@CarlosAM_INTEL.

[bkingsbury]

Thanks but I did try them first. They sent me to Intel. They said that they did not support the I2C bus through the PHC

[CarlosAM_INTEL]

Hello, @bkingsbury:

Thanks for your reply.

You should find the information that may help you in section 18, on pages 140 through 145 of the Intel® 300 Series Chipset Family OnPackage Platform Controller Hub External Design Specification (EDS) – Volume 1 of 2 document # 566439. Also, in section 15, on pages 621 through 689 of the ntel® 300 Series Chipset Family OnPackage Platform Controller Hub External Design Specification (EDS) – Volume 2 of 2 document # 565870

You need to verify with the assistance of the developer of the design associated with your questions that the suggested information is supported by their device and answer your request.

You can find these documents when you are logged into your Resource and Design Center (RDC) privileged account on the following websites :

https://cdrdv2.intel.com/v1/dl/getContent/566439 

https://cdrdv2.intel.com/v1/dl/getContent/565870

The RDC Account Support form is the channel to process your account update request or report any inconveniences with the provided websites. It can be found at:

https://www.intel.com/content/www/us/en/forms/support/my-intel-sign-on-support.html

Best regards,

@CarlosAM_INTEL.

[bkingsbury]

Thank you. I'm trying to develop code that runs in the UEFI shell. What routines can I call to do an I2c read or write?

[CarlosAM_INTEL]

Hello, @bkingsbury:

Thanks for your reply.

Based on your replies, could you please let us know the name of your BIOS vendor?

We are waiting for your reply.

Best regards,

@CarlosAM_INTEL.

[bkingsbury]

I pretty sure it is AMI bios (UEFI)

[CarlosAM_INTEL]

Hello, @bkingsbury 

Thanks for your clarification.

You need to contact the cited Intel BIOS Vendor (IBV) because the UEFI is distributed and supported by each BIOS vendor, they have their own information on their channels of support, even i2c is an open standard. They should provide as a reference something similar to the information stated on the following website:

https://www.insyde.com/press_news/blog/uefi-pi-13-review-part-1-i2c-bus-protocol  

We provide support during Operating System (OS) stage with drivers.

Best regards,

@CarlosAM_INTEL.

[pietrushnic]

We have experience in developing UEFI applications and drivers. At some point, I wrote a very simple SMBUS driver which dumps DRAM SPD EEPROM data. This was as simple as sending commands through  IoDev->Pci.Read/Write using correct SMBUS controller bus-device-function and offset address.

Do you have precise issues?