On Wed, 2012-02-08 at 10:57 +0000, Liam Girdwood wrote:
On Wed, 2012-02-08 at 16:06 +0530, Vinod Koul wrote:
On Wed, 2012-02-08 at 09:54 +0000, Liam Girdwood wrote:
Atm, the machine driver would have to enable any system clocks before the codec driver could use them.
But how would machine driver know _when_?
The machine driver gets all the PCM ops that the codec driver does and is responsible for configuring CODEC PLLs and clocks (usually in it's hw_params()).
We want to dynamical turn off this clock when not is use and turn on only when codec is using. So I was thinking of turning this ON in codecs .set_bias_level callback, but how to propagate this into machine driver?
It's usually done in the machine driver hw_params() since at this point we know the rate, format etc that can have a bearing on the clock configuration. You could switch it OFF in machine hw_free().
For DAIs yes. But I also have a Vibra controller on codec, which can be configured and turned On using alsa controls. I treat the Vibra as input (or as recoently as Mark has done a signal generator) so mixer connections ensure loopback from Input to Output and my codec is powered ON. Those cases DAI doesn't help me.
Possibly a .set_machine_clock_input callback which can be called from codec driver in .set_bias_level callback?