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-- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
