[Ksummit-2013-discuss] ARM topic: Is DT on ARM the solution, or is there something better?

[David Woodhouse]

>
> On Thu, 2013-10-24 at 12:47 +0100, David Woodhouse wrote:
>
>> If you can automatically infer the correct clock/interrupt/etc in order
>> to do DMA correctly, despite the fact that it wasn't explicitly spelled
>> out in the old DT, then the property is *not* a "required" property.
>> It's optional, and you have a default behaviour for when it's not
>> present.
>
> so inside the new version of driver-hwcrypto.c:
>
> if (irq_of_parse_and_map(...) == NO_IRQ) {
> 	switch (get_soc_model()) {
> 		case SOC1:
> 			irq = 51;
> 			break;
>
> 		case SOC2:
> 			irq = 62;
> 			break;
>
> 		[...]
> 	}
> }


If you are correct to insist that DMA needs yo be supported in the new
driver *even* with old firmware, then yes, maybe.

The alternative is a quirk to "fix" the DT up on the affected boards and
not actually doing the special cases in the driver itself. But that can be
seen as an implementation detail.

-- 
dwmw2