At Fri, 19 Jun 2009 10:53:22 +0100, Mark Brown wrote: > > On Fri, Jun 19, 2009 at 10:04:47AM +0200, Takashi Iwai wrote: > > > yet another thing I've worked recently on is a bit more generalized > > framework for jack-sense reporting for HD-audio. This supersedes the > > existing jack-sense reporting via the input layer. In addition, it > > gives the corresponding control elements. > > It'd be nice to keep the input API interface as well - one of the > reasons I carried on with the existing input interface was that the > existing userspace stuff I found was using the input API in one way or > another. In the embedded space it appears to have often been convenient > for people to read jack sense from a GPIO as part of a GPIO keyboard > they're already using which was part of the reason it was never really > joined up with ALSA in the past. Don't worry, it's kept as is. The control elements are just additions. Sorry, my wording was unclear. Let me clarify: the input jack API is there and used as is now. What I meant as "supersedes" is that the code to create and handle the input jack instances in HD-audio driver is generalized to one and used together with the control API. > I suspect that which interface is more convenient will depend on what > the application responding to the events is doing. For system-wide > things that aren't focused on audio being able to use the general input > API makes some sense, while for audio-focused applications that are > already using ALSA sitting within the ALSA APIs is useful. This sort of > system wide thing is probably more common in the embedded space, though > HAL/DeviceKit do similar things in the desktop space for other kinds of > hardware. Right. > Perhaps rather than superceeding the existing ABI it'd make sense to > have something in user space as either a plugin or part of the library > which remaps things into a more ALSA framework? I confess I've no idea > what sort of work is involved in doing that; it may be simpler to just > provide two ABIs. > > > For example, you'll have "Jack HP-Out" (or a bit more verbose like > > "Jack HP-Out at Ext Rear") control via control API as well as other > > mixer controls. This can notify when a jack is plugged/unplugged. > > Including the colours (where reported) is often very helpful for > figuring out what's what. The pictures manufacturers seem fond of using > for describing the jack functions aren't always models of clarity to the > general user. Yes, HD-audio spec gives such information, too. However, the verbose information like a color doesn't fit into the id string. A better option would be through the additional TLV like dB scale. I just considered but didn't write up yet. thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
