Simple application to read current clocks of ATi Radeon cards (xf86-video-ati, xf86-video-amdgpu).
xf86-video-ati and xf86-video-amdgpu driver

Install and run radeon-profile-daemon (https://github.com/marazmista/radeon-profile-daemon) for using this app as normal user. Otherwise app need to be run with root privilages for changing power profiles (and clocks readings sometimes). You can add username ALL = NOPASSWD: /usr/bin/radeon-profile to your /etc/sudoers. Here is tip for run app as normal user but involves change permissions to system files: http://bit.ly/1dvQMhS

Fan control is available only on Radeon HD 7000 series and above.