Lock on Trunk

[Dean Do]

Hi,

I have a question on access control.  Is there a way to prevent all commits
on the main trunk and allow commits on branches only?  Once the changes on
the branch are reviewed and approved for merging into the main trunk, then
the main trunk can be manually opened up temporarily for those changes only.

Please advise if there's a way to implement this type of controlled access.

Thanks,
Dean