On Mon, Sep 28, 2015 at 04:16:12PM +0800, sugar wrote:
在 9/24/2015 00:24, Mark Brown 写道:
My initial thought here is that the machine driver should be responsible for setting this and then the DAI driver should check to see if symmetric_rates are in use and configure itself appropriately. Is there a reason why this won't work here?
It's for i2s ip configuration, in the most situation, there is no need to use this property, except one case:
In order to save gpio pins for other function use, we may use single lrck(tx or rx) pin. of course, it depends on product design. when in i2s slave mode, we need to configure this to share lrck with tx/rx inside i2s logic.
symmetric_rates flag works fine on rockchip platform, but it can't cover the above case.
Do you have any suggestion about this or maybe there is no need to upstream this special part?
What makes you say that the symmetric_rates flag can't be used to cover this case? What you describe above is hte normal reason for needing to enforce symmetric_rates. The driver should be able to check if the flag has been set just as well as the core is.