RK3399 DSI and panel driver question

Does anyone have any experience with RK3399 DSI and panel bringup in u- boot? I believe I have the vopl and mipi configured - I can see the backlight come on at least - but I think I need a panel-specific driver. Simple-panel doesn't send dsi commands so the panel never inits. And I'm not clear if I need the dsi-host driver bound to the vopl in the way the stm32f469 does it.

I have a BSP that uses an old u-boot with backported Linux DRM code that supposedly works but I've not been able to get that working either. I found a dsi panel driver there but it wants a mipi_dsi_device to send dsi commands and I'm not sure how to configure one of those.

Any pointers would be appreciated. Thanks.