On Mon, Mar 22, 2010 at 04:46:08PM +0200, Peter Ujfalusi wrote:
On Monday 22 March 2010 16:15:44 ext Mark Brown wrote:
I don't see any fundamental problem here - mostly this just maps on to "if the widget is powered on write this value, otherwise write the value configured by the control.".
Hmm, I suppose it could be possible to pass the name of the DAPM widget, a bitmask to a control... Than in the handler in the core we could walk through the DAPM widgets, and find the one, check the status, and if it is on, we allow the write, otherwise we could use the mask to write only the things, that it is needed.
Something like that, yes - the walk could happen at startup time to avoid having to do it repeatedly.
But, in TWL case I'd like to filter out also the writes which is done by the DAPM widgets (which is visible from the user space, the mixers). As it is now, if user changes the mixer, which is associated with DAPM widget (and it is different than the PGA, they are DAPM_MIXER), than that write goes directly to the register, and this write takes the cached value, makes the changes and than writes it to register. This also enables the gain (which enables the amp, which takes power).
Remember, the register cache is below the controls and transparent to them - if the controls haven't written a value to the chip then it will not appear in the register cache so other controls will not be affected.
Well, I was rather hoping I could convince you to make this more generic. But if that's not possible then yes, please do make the commit message clearer.
I need to study other codes as well, before I could start doing something more generic, which I totally agree would be beneficial for others as well. But for now, I would like to update the commit message, and come back later, and revisit the possibility of similar, and more generic ways of doing this.
I guess.