Dual Role USB - Intel Chipset 300

[jgranger]

Hi, 

I have an Intel Whiskey Lake processor using the Intel 300 Chipset. I am trying to configure the USB-C ports to swap from host mode to device mode. The documentation (https://www.intel.com/content/www/us/en/products/docs/chipsets/300-series-chipset-on-package-pch-datasheet-vol-1.html) states that this is supported, but a message must come from the EC over LPC bus

"Note: This HW signal is not used on the PCH for dual role mode selection (OOB) LPC SCI/SMI ".

In prior chipset models (100/200) this was handled by setting the 'DEVICE MODE CONTROL REG 0 (DUAL_ROLE_CFG_REG0)—Offset 80D8h'. This could be done in Linux using '/sys/class/usb_role/intel_xhci_usb_sw-role-switch'.

I have enabled xDCI in the BIOs and can see the PCI entry present when running lspci

```
00:14.0 USB controller: Intel Corporation Cannon Point-LP USB 3.1 xHCI Controller (rev 30)
00:14.1 USB controller: Intel Corporation Device 9dee (rev 30)
```

I would like to know exactly what the PCH is expecting from the EC to trigger this role switch and if any documentation or support can be provided to assist me in this effort.

Kind regards,
Sam

[NormanS_Intel]

Hello jgranger,

Thank you for posting in the community!

To ensure you receive the most specialized assistance, we have a dedicated forum that addresses these specific concerns. Therefore, I will be moving this discussion to our embedded Forum. This will allow our knowledgeable community and experts to provide you with timely and accurate solutions.

Best regards,

Norman S.

Intel Customer Support Engineer

[CarlosAM_INTEL]

Hello, @NormanS_Intel:

Thank you for contacting Intel Embedded Community.

Based on the last reply provided by the customer, this forum is not related to embedded processors, as you may confirm on the following website:

https://www.intel.com/content/www/us/en/products/sku/193563/intel-core-i78665u-processor-8m-cache-up-to-4-80-ghz/specifications.html

Due to this, this type of consultation is out of our scope of support.

Please consider this information when you suggest transferring or creating a new forum under the channel mentioned in your message.

Best regards,

@CarlosAM_INTEL.

[CarlosAM_INTEL]

Hello,  @jgranger:

Thank you for contacting Intel Embedded Support. 

We have received your request but we need to address the following questions to understand it:

Could you please clarify if this request is related to a design developed by you or by a third-party company?

Could you please let us know the name of the manufacturer, the part number, and where we can find the information if this request is related to a third-party design?

If it is your design, please let us know the place of purchase of the cited Intel processor and its part number.

What is the name of the developer of the BIOS related to the cited situation?

We are waiting for your reply.

Best regards,

@CarlosAM_INTEL.

[jgranger]

Hi @CarlosAM_INTEL 

Thank you for the reply.

The current hardware I am using is the Lenovo T490 (20N20041US) laptop, however the inquiry is related to the Intel 300 chip-set and above and is not necessarily specific to my exact hardware. The processor in question is the "Intel Core i7-8665U", but this inquire applies to multiple processors. My aim is to understand what is required / expected from the PCH perspective from the EC / BIOS in order to swap roles from host to device mode on a specific USB port. In the 100/200 chip-set this is straightforward with the use of a register; and only a single port was allocated as Dual Role, however this is not the case with the 300 and above chip-sets.

Intel® 300 Series Chipset Family On-Package Platform Controller Hub Datasheet – Volume 1 of 2

"The xDCI shares all USB ports with the host controller, with ownership of the port being decided based the USB Power Delivery specification. Since all the ports support device mode, xDCI enabling must be extended by System BIOS and EC. While the port is mapped to the device controller, the host controller Rx detection must always indicate a disconnected port."

Thanks for your help. 
Sam

[jgranger]

Hi @NormanS_Intel 

I hope you're doing well. My post has been moved across various forums and seems to have lost some visibility. Could you please help route this question to the appropriate individuals who might provide insights into the correct implementation of Dual Role USB on the Intel 300 chipset and above?

Thank you for your assistance!

Best regards,
Sam