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

[Stephen Warren]

On 10/24/2013 01:13 PM, Maxime Bizon wrote:
> 
> 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;
> 
> 		[...]
> 	}
> }

Uggh. Then you start embedding all the per-SoC or per-board description
in the drivers. It doesn't seem scalable for every driver to know about
every HW configuration. Adding extra IRQ/DMA/... properties to DT to
enable new features should be fine.