GPIO buffered output DMA example code

[marchingband]

The BL616 and BL808 Reference Manuals describes a mode of the GPIO driver for "buffered output", and also mentions a DMA channel for it.
This peripheral looks PERFECT for driving WS2812 rgb leds.
I have not been able to initialize this mode successfully.

Would it be possible to publish some example code showing how to initialize it, and how to connect it to DMA?

Thank you!