Guidance on implementing a baremetal USB Host

[gueste]

Hello everyone, 

I'm currently working on a bare-metal USB host project on the Eclypse Z7 platform, utilizing the USB Micro AB connector (J5) present on the board. 
PL is already set up to be able to use the USB 0 adapter, but the example code provided with the "usbps" driver only seems to cover DEVICE-related applications.
Is there any HOST example available, or can anyone provide some guidance on the necessary steps of setting the USB host up?

I'm just not able to get it up and running.

I'm glad for any advice.
Thanks.

 

Edited June 15, 2022 by gueste

[gueste]

Thanks for your help.

The driver doesn't support USB host functionality, although it's written in the driver documentation.

This info was stated in the xilinx confluence wiki on:

https://xilinx-wiki.atlassian.net/wiki/spaces/A/pages/18842117/Zynq+Standalone+USB+device+driver#Known-Issues-and-Limitations:

 

Known Issues and Limitations:

- Host mode is not supported by the standalone driver

- OTG mode is not supported by the standalone driver

 

Therefore, we had to switch to a different system concept.

Edited June 30, 2022 by gueste

[zygot]

The AMD-Xilinx Wiki: https://xilinx-wiki.atlassian.net/wiki/spaces/A/overview?homepageId=18844350 is their source for processor related support. They have example projects with limited support for ZYNQ USB HOST mode applications using Linux, but I don't recall seeing anything for the StandAlone OS. You can see if the SDK or Vitis offers anything. Don't expect full-blown USB HOST functionality.

 

[zygot]

Separating the marketing hype from the facts always requires a bit of spelunking. Often the answers are hidden in some deep remote crevice of the cave.

OTG Host mode requires quite a bit of software to support the hardware capabilities. If it were easy Xilinx would have application notes and design examples. They don't. That says something about their commitment to their products and customers. Unfortunately, it doesn't stop them from providing hope in the form of unreasonable expectations. I suppose that these days, that's par for the course.

Anyway, before selecting a design architecture, it's always good practice to find evidence supporting idea that a feature, implied or stated, can actually be implemented with a reasonable effort, using the vendor design and development tools.

Sometimes, a trip to the ARM website for technical information can provide clues to a path around obstacles.