On 03/19/2012 09:45 AM, Arnd Bergmann wrote:
> On Monday 19 March 2012, Stephen Warren wrote:
>>> Maybe one can use named properties in a new device node in that case,
>>> like this:
>>>
>>> bus {
>>> dma: dma-controller {
>>> #dma-cells = <1>;
>>> };
>>>
>>> device {
>>> compatible = "device";
>>> channel: dma-channel {
>>> type = <0x1>;
>>> name = "foo";
>>> number = <23>;
>>> direction = <3>;
>>> };
>>> dma-requests = <&dma &channel>;
>>> };
>>> };
>>
>> For reference, this is very similar to how the pinctrl bindings work,
>> except that they require the "channel" node to be a child of the DMA
>> controller, and hence "dma-requests" doesn't contain <&dma &channel>,
>> just <&channel>, since "dma" is the parent (or grand-parent) of "channel".
>
> Right, but the difference beytween the pinctrl binding and what I
> describe here is that the channel description would be part of the
> dma engine driver specific binding, not the generic binding that
> is visible to device drivers.
That's actually true for pinctrl as well: Common pinctrl bindings cover
the content/format of "dma-requests" and a requirement for a
"dma-channel" node, whereas the per-pin-controller bindings define the
content of node "dma-channel".
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
