How to show Git log history (i.e., all the related commits) for a sub directory of a Git repository

Let’s say that I have a Git repository that looks like this:

foo/
  .git/
  A/
   ... big tree here
  B/
   ... big tree here

Is there a way to ask git log to show only the log messages for a specific directory? For example, I want to see what commits touched files in foo/A only.