Another problem is the crossbar mixer. It is a full 8x4 crossbar with 28 bit gain controls on each path. There are four 32 byte registers, each register holds 8 32 bit wide gain fields. There are several more mixers with 28 bit gain controls. 28 bit gain fields are all on all of the bass/loudness/etc control. On 7/20/08, Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > On Sat, Jul 19, 2008 at 10:18:55PM -0400, Jon Smirl wrote: > > > How do I define a volume control that is the bottom 12 bits of a 32 > > bit register? > > > #define SOC_SINGLE_VALUE(reg, shift, max, invert) ((reg) | ((shift) << 8) |\ > > ((shift) << 12) | ((max) << 16) | ((invert) << 24)) > > > This looks like it only support an 8 bit max. Is there another way to do it? > > > SOC_SINGLE() (or SOC_SINGLE_TLV() if you've got dB scale information for > the volume control, which is likely?) is the way to do it but like you > say it's not able to cope currently. Since invert is a boolean so there > should actually be enough space to store a 12 bit max so it shouldn't be > such a major job to adjust for this unless I'm missing something, I've > only had a brief look. > > Also note that the core currently has assumptions in it that registers > aren't bigger than 16 bits - the main thing is that it uses unsigned > shorts for passing them around. Someone posted in the past week about > fixing this. > > If you don't want to do core changes then either write a custom control > or (if the stuff in the upper bits will allow it) adjust the shift to > ignore the bottom 4 bits of the control. The ASoC control macros all > boil down to standard ALSA controls types and you can mix in regular ALSA > controls without problems if required - the macros just save having to > implement standard register accesses by hand. > -- Jon Smirl jonsmirl@xxxxxxxxx _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
