On 09/19/15 21:42, Mark Brown wrote:
On Fri, Sep 11, 2015 at 04:18:02PM +0300, Jyri Sarha wrote:
The updated binding provides a way to set clock-ID and direction parameters for DAI drivers set_sysclk() call back.
I proposed something similar about a year ago, but Mark rejected that at the time. This RFC is to start that discussion again. This time before I do any code changes.
What's the use case again? Can we address this by converting the relevant drivers to the clock API (or improving their clock API support)?
Sorry, I forgot to reply this earlier. The reason why we need this is the way McASP driver uses and provides clocks for different purposes. The most pressing need is to be able to select if we want to use some external clock pin as an input for McASP clock divider that produces the i2s bit-clock or if we want to use McASP's internal clock source.
There are several other things this binding would allow us, and others with flexible i2s HW, to do. Some TI codecs would also benefit from a flexible way of describing the used clock configuration, but Peter know that part better.
I tried to make the binding as flexible and generic as possible. But I do not currently see any immediate need for more than one set_sysclk() call per dai. I just did not see any reason to not allow it either.
Best regards, Jyri