On 28.09.2015 16:26, Timur Tabi wrote:

Alexander Popov wrote:

quoted

I've just followed devicetree/bindings/dma/dma.txt...
This "rx-tx" doesn't mean much but it could show that LocalPlus Bus FIFO
uses a single DMA read-write channel. Should I really drop it?

Hmmm, I'm not sure.  Is there anything else (besides your driver) that
parses this device tree node?

No, mpc512x_lpbfifo.c is the only piece of code which is going to use this
device tree node.

dma.txt says this:

    "The specific strings that can be used are defined in the binding of the
DMA client device."

So this looks like it's driver-specific,

Yes.
MPC512x LocalPlus Bus FIFO uses the channel #26 of the DMA controller
both for reading and writing, and other DMA clients use other specific
DMA channels. This channel assignment is fixed in hardware and described
in the Reference Manual.

but it is a required property.
I guess you should keep it, but I think you should get a second opinion.

Ok, thanks.

Best regards,
Alexander