On Friday 24 May 2002 01:47, Eliot Blennerhassett wrote: > I'd like some idea how hard it would be to write an ALSA driver either as a > compatibility layer on top of our existing driver, or from the ground up. > I realise that this is rather a broad question, so please consider this an > invitation to enter discussion, rather than a request for you to go off and > do a lot of work for me.
Howdy Eliot, wonderful to see you on the list! The two basic components that would have to be addressed to get ALSA support are the kernel and user-space (alsa-lib) components. My sense is that the alsa-lib interface could be implemented as a layer between the application and HPI, much as the existing Windows sound driver is implemented. The bigger challenge would be to get the kernel part working. ALSA developers are encouraged to use alsa-lib whenever possible, but it *is* possible to use the kernel ioctls directly too. Whether it would make any sense (or would even be possible) to implement alsa-lib emulation on top of a different set of ioctls is a good question. As for supporting features on the cards, other than a few oddball functions (like the GPIO calls or HPI_SetStreamOutVelocity()), I don't think there would be a great deal of difficulty. It would be nice to have an envrionment where *both* APIs were available -- HPI is quite handy for doing some things. Cheers! |-------------------------------------------------------------------------| |Frederick F. Gleason, Jr.|WAVA Radio - 105 FM |Voice: 1-(703)-807-2266 | | Director of Engineering |1901 N. Moore Street| FAX: 1-(703)-807-2245 | | |Arlington, VA 22209 | Web: HTTP://www.wava.com| |-------------------------------------------------------------------------| | A rock pile ceases to be a rock pile the moment a single man | | contemplates it, bearing within him the image of a cathedral. | | -- Antoine de Saint-Exupery | |-------------------------------------------------------------------------|
