On 05/24/2016 07:20 PM, Mark Brown wrote:
>> Not having used devicetree that much it was surprisingly hard to
>> figure out how to assign a stable bus number to a spi bus. Add
>> a simple example that shows how to do that.
>
> I'm not sure this is something we want to support at all, I can't
> immediately see anything that does this deliberately in the SPI
> code and obviously the "bus number" is something of a Linux
> specific concept which would need some explanation if we were going
> to document it. It's something I'm struggling a bit to see a
> robust use case for that isn't better served by parsing sysfs,
> what's the goal here?
Well, that's how it works right now:
commit bb29785e0d6d150181704be2efcc3141044625e2
Author: Grant Likely <grant.lik...@secretlab.ca>
Date: Fri Dec 21 19:32:09 2012 +0000
spi/of: Use DT aliases for assigning bus number
> + if ((master->bus_num < 0) && master->dev.of_node) +
> master->bus_num = of_alias_get_id(master->dev.of_node, "spi");
If this isn't something that should be in the Documentation/devicetree
because it's not generig enough, where should Linux-specific
interpretations such as this be documented?
/Christer
