Hi Oleg,
1. You have to decide on configuration time if you want to use host controlled mode or not. It's not possible to change this later without re-flashing. Note that a few EHIF commands are also available in autonomous mode (including device info) For a list of available EHIF commands in the different modes, please refer to the User Guide table 26. http://www.ti.com/litv/pdf/swru250l
2. We do this in the codec unless you add fixed offset to the volume. have a look in the configurators help menu under 'volume control panel - how the settings work' for a better description.
.Regards,
Kjetil