On 16-05-19, 11:31, Alexandru Ardelean wrote: > From: Lars-Peter Clausen <lars@xxxxxxxxxx> > > The AXI-DMAC supports different types of interface for the data source and > destination ports. Typically one of those ports is a memory-mapped > interface while the other is some kind of streaming interface. > > The information about which kind of interface is used for each port is > encoded in the devicetree. > > It is also possible in the driver to detect whether a port supports > memory-mapped transfers or not. For streaming interfaces the address > register is read-only and will always return 0. So in order to check if a > port supports memory-mapped transfers write a non-zero value to the > corresponding address register and check that the value read-back is still > non zero. > > This allows to detect mismatches between the devicetree description and the > actual hardware configuration. > > Unfortunately it is not possible to autodetect the interface types since > there is no method to distinguish between the different streaming ports. So > the best thing that can be done is to error out when a memory mapped port > is described in the devicetree but none is detected in the hardware. Applied, thanks -- ~Vinod
