quoted

+  sysreg:

Needs a vendor prefix.

Thanks. I'll use "samsung,sysreg-phandle".

quoted

+    $ref: '/schemas/types.yaml#/definitions/phandle'
+    description: phandle for FSYS sysreg interface, used to control
+                 sysreg register bit for UFS IO Coherency

Is there more than 1 FSYS? If not, you can just get the node by its
compatible.

The phandle can be differed each exynos SoCs, AFAIK. I think other exynos
SoCs since exnos7 will need this but not upstreamed yet...

Also, what about 'dma-coherent' property? The driver core needs to know.

Yes. 'dma-coherent' should be listed as well.

Best Regards,
Chanho Park