Here you can find my personal notes of the lecture Funktionalanalysis given by Prof. Dr. Harald Garcke at the University of Regensburg in the winter term 2013/14. (German text)
Note: These lecture notes are neither official nor errorless. If you find mistakes, please notify me or make a pull request.
Note that the master branch lacks the two final lectures about Sobolev spaces. I didn't have time to review that chapter and to be honest, i don't understand much of it (yet), so it won't make its way to the master branch anytime soon. Those who don't mind reading that chapter in its present state may find it "as is" in an additional branch (see below).
See branch master for the master branch (without ch. 11). See branch master+sobolev for the master branch plus chapter 11.