On 04/08/2016 12:06 PM, Jose Abreu wrote: > Hi Mark, > > > On 07-04-2016 18:53, Mark Brown wrote: >> On Thu, Apr 07, 2016 at 05:53:59PM +0100, Jose Abreu wrote: >> >>> + Optional properties: >>> + - snps,use-dmaengine: If set the driver will use ALSA DMA engine. If set >>> + it is required to use the properties 'dmas' and 'dma-names'. >> This is not a good interface, it's describing Linux internal APIs. If >> the device needs to operate in PIO mode it should just do that. > > I added this interface because there is no direct way to check if DMA is > available on the I2S controller so it is not possible to automatically change > between DMA and PIO mode. As the I2S controller can be built with or without > DMA > support it is necessary to somehow check if DMA is enabled or not and > according > to that use either ALSA DMA engine or the custom platform driver sent in these > patches. I did not want to remove drivers functionality so I added this > property > to the DT. This way a user can select between DMA and PIO mode.
That's OK, but you need to describe the hardware, not the indented behavior of the software driver.
