Hello Mark,
On 04/11/2017 11:10 PM, Mark Brown wrote:
On Tue, Apr 11, 2017 at 03:44:52PM +0000, Olivier MOYSAN wrote:
However, regarding STM32 I2S driver, I'm wondering if selecting DAI is the best way to configure interface as tx, rx or fd.
Why do you even need to configure this?
The IP provides two data wires, SD in and SD out. So it can be configured either as capture or playback only, or full-duplex. This corresponds to a mode selection through a register configuration.
Maybe, it is more relevant to configure DAI according to DMA configuration from I2S node. This would moreover avoid to allocate 2 dmas channels when not necessary (tx or rx only). If you agree with this, I will implement this change in a v2.
That sounds wrong, I'd expect this wiring to be done statically as part of the .dtsi for the SoC (or just grabbed as needed at runtime if things are flexbile enough) rather than being a configuration thing done per board... I had thought that this was configuration reflecting different ways of taping out the IP with different feature sets, is that not the case?
This configuration is board dependent. The IP may be used as rx, tx or fd depending on board. So I think it can make sense to have a DMA configuration linked to board, and to set IP mode accordingly.
BRs olivier