bluetooth: add wideband audio codec negotiation to HFP

The HFP protocol supports the ability to negotiate codecs if that is
supported by both AG and HF.  This patch adds advertising of codec
negotiation support and the ability to negotiate a codec change.  The
only currently supported extra codec (as of HF 1.7.1) is mSBC.  mSBC
requires that the transmission be done over an eSCO link with
Transparent Data.  The linux kernel ensures the former, but we have to
manually set the socket to transparent data.

Signed-off-by: James Bottomley <>
1 file changed