ALSA kernel sequencer client

ALSA kernel sequencer client

[Lee Revell]

I'm developing a driver for a device that's like an MPU output port, but
some extra hardware registers need to be written to when note on/off
messages arrive.  Since the MIDI stream must be interpreted and hardware
needs to be accessed directly I think I need to develop an ALSA
sequencer kernel client.

I remember seeing some docs for developing this kind of thing, but can't
find them - can someone point me in the right direction?

Lee


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Re: ALSA kernel sequencer client

[Clemens Ladisch]

Lee Revell wrote:
> I'm developing a driver for a device that's like an MPU output port, but
> some extra hardware registers need to be written to when note on/off
> messages arrive.  Since the MIDI stream must be interpreted and hardware
> needs to be accessed directly I think I need to develop an ALSA
> sequencer kernel client.

Currently, a sequencer client is only used for devices where all MIDI
messages must be interpreted by the driver and where the device doesn't
ever see them.  The USB MIDI and serial MIDI drivers do their own
parsing.

This doesn't mean that you shouldn't use a sequencer client.

> I remember seeing some docs for developing this kind of thing,

I'm sure there never were such docs.

> but can't find them - can someone point me in the right direction?

Use the Source, Luke^H^H^Hee: the USB MIDI driver was a sequencer client
before October 2002.


HTH
Clemens

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Re: ALSA kernel sequencer client

[Lee Revell]

On Mon, 2006-07-24 at 13:18 +0200, Clemens Ladisch wrote:
> Lee Revell wrote:
> > I'm developing a driver for a device that's like an MPU output port, but
> > some extra hardware registers need to be written to when note on/off
> > messages arrive.  Since the MIDI stream must be interpreted and hardware
> > needs to be accessed directly I think I need to develop an ALSA
> > sequencer kernel client.
> 
> Currently, a sequencer client is only used for devices where all MIDI
> messages must be interpreted by the driver and where the device doesn't
> ever see them.  The USB MIDI and serial MIDI drivers do their own
> parsing.
> 
> This doesn't mean that you shouldn't use a sequencer client.
> 

I think I'm going to use a rawmidi device and snoop the MIDI stream for
note on/note off.  It does not look too hard, and unlike the sequencer
is documented.

> > I remember seeing some docs for developing this kind of thing,
> 
> I'm sure there never were such docs.
> 
> > but can't find them - can someone point me in the right direction?
> 
> Use the Source, Luke^H^H^Hee: the USB MIDI driver was a sequencer client
> before October 2002.

Thanks for the info.

Lee


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