Broadcom provides three drivers for their Wi-Fi chipsets :
brcmsmac : Open source kernel driver
wl : Proprietary Broadcom STA driver
The open source kernel driver can not manage power saving. wl driver must be used instead.
For Debian-based distro, you need to install broadcom-sta-dkms package :
root@localhost:~#apt-get install broadcom-sta-dkms
This will install the wl driver. Make sure that all the other Broadcom drivers (b44, b43legacy, b43, brcm80211, brcmsmac, ssb) are blacklisted.
While being installed, the broadcom-sta-dkms creates a blacklist file : /etc/modprobe.d/broadcom-sta-dkms.conf