There isn't any official support, but a user in the SmartThings Community forum has created some device types that should work with the motion sensor and on/off switch here:
I have created a simple device type for the Xiaomi Smart Button that can be found various places for around $10. Other users have stated that this device loses connectivity to the hub after a while, but I have only had the device in hand for a couple hours so I'll report back what I find.
The device should work with SmartApps that work with button devices like the Aeon minimote. It registers as button 1 pressed, and button 1 held if you hold it down for 4 seconds (configurable in preferences, but a lower number may affect reliability of the device properly distinguishing the two).
One user reports that the temperature sensor works without any handler:
You can pair door, motion and button with ST with a couple tries. For button and temp, follow my other thread on how to pair those.
But all except temp sensor requires custom device handler.
Therefore, as far as I can tell, you just need the custom handler for the on/off switch and motion sensor as provided in the thread I linked - otherwise, you can pair them as normal.