[LAD] Details about Mackie Control or Mackie Human User Interface

Hi all, I'm a ALSA developer. I currently focus on developing sound drivers for devices on IEEE 1394 bus. In this developing period for Linux 4.3, I'm working for TASCAM FireWire series such as FW-1884 and FW-1082. Well, are there some developers who have enough knowledgement about MIDI messaging rule for Mackie Control or Mackie Human User Interface(HUI)? As long as investigating FW-1082 and FW-1884, these two models transfer control messages over IEEE 1394 isochronous packets, The shape of these messages is similar to bitmap. In detail, see my RFC on alsa-devel: [alsa-devel] [RFC][PATCH 26/37] ALSA: firewire-tascam: add MMAP support to show status and control message http://mailman.alsa-project.org/pipermail/alsa-devel/2015-July/094817.html To enable userspace applications to handle these messages, a converter to MIDI messages is required, as Windows/OS X drivers did. In my original plan, I off-load this task to userspace driver applications by adding mmap(2)ed page. While, due to some reasons, it's better to implement the converter into kernel driver. As long as I know, for these models, there're three types of the converter; usual MIDI messages such as Control Change (CC), Mackie Control and Mackie Human User Interface, while I have a little knowledgement about the latter two types. For this occasion, I want to know the details. If a cost to implement one of these two types, I'll use it for the converter. Else, I use usual MIDI messages for my patchset to ALSA upstream. Thanks Takashi Sakamoto