On 10/30/2017 4:24 PM, Kim Phillips wrote: > On Mon, 30 Oct 2017 15:46:51 +0200 > Horia Geantă <horia.geanta@xxxxxxx> wrote: > >> +===================================================================== >> +CAAM DMA Node >> + >> + Child node of the crypto node that enables the use of the DMA capabilities >> + of the CAAM by a stand-alone driver. The only required property is the >> + "compatible" property. All the other properties are determined from >> + the job rings on which the CAAM DMA driver depends (ex: the number of >> + dma-channels is equal to the number of defined job rings). >> + >> + - compatible >> + Usage: required >> + Value type: <string> >> + Definition: Must include "fsl,sec-v4.0-dma" >> + >> +EXAMPLE >> + caam-dma { >> + compatible = "fsl,sec-v5.4-dma", >> + "fsl,sec-v5.0-dma", >> + "fsl,sec-v4.0-dma"; >> + } > > If this isn't describing an aspect of the hardware, then what is it > doing in the device tree? > > Kim > Because the caam_dma driver is a platform driver I needed to create a platform device to activate the driver. My thought was that it was simpler to implement it using device tree. The next patch version will create the platform device dynamically at run time. BR, Radu