Re: [PATCH v5 05/10] dt-bindings: irqchip: Introduce TISCI Interrupt router bindings

From: Lokesh Vutla
Date: Thu Feb 14 2019 - 12:32:41 EST


Hi Tony,
Please do not snip the on going discussion.

On 2/14/2019 9:11 PM, Tony Lindgren wrote:
> * Lokesh Vutla <lokeshvutla@xxxxxx> [190214 08:39]:
>> IMHO, device ids are something which can be used in DT. There are many other
>> things like the interrupt ranges etc.. which are discoverable from sysfw and we
>> are implementing it.
>
> We need to describe hardware in the device tree, not firmware.
>
> If you have something discoverable from the firmware, you should
> have the device driver query it from sysfw based on a hardware
> property, not based on some invented enumeration in the firmware.

Yes we are already querying sysfw for all the irq ranges that can be
discoverable. The topic of discussion here is about the parent interrupt
controller id. I am not sure how you are expecting an id be discoverable
from system firmware especially with a name.

> If there is some device to firmware translation needed, hide that
> into the device driver and keep it out of the device tree.

If preferred this can be moved to of_match_data attached to each
compatible property. Then for each SoC a new compatible needs to be created.

>
> For example, look at the interrupt binding where the interrupt
> is phandle to the controller and the bit offset from the interrupt
> controller instance.
>
> You need to use device IO address + bit offset (or register
> offset) type indexing for device tree here. Something out of
> the TRM that makes sense to developers.
>


[1]
https://github.com/devicetree-org/devicetree-specification/releases/download/v0.2/devicetree-specification-v0.2.pdf

Thanks and regards,
Lokesh