Re: [DT Question] "simple-mfd" DT binding

[Masahiro Yamada]

Hi Lee, Linus,

Thanks for your comments!

2017-05-22 17:43 GMT+09:00 Linus Walleij <linus.walleij@xxxxxxxxxx>:
> On Mon, May 22, 2017 at 3:29 AM, Masahiro Yamada
> <yamada.masahiro@xxxxxxxxxxxxx> wrote:
>
>> Because "simple-bus" indicates that child nodes are
>> simply memory mapped, but the node "register-bit-led"
>> can not be memory-mapped.
>> So, "simple-mfd" can not be replaced "simple-bus" here.
>
> Yeah... just like Lee points out, you are spot on, this is exactly
> the reason why we created "simple-mfd" in the first place
> IIRC.

OK, Linux treats simple-bus and simple-mfd in the same way
as far as I see drivers/of/platform.c

Perhaps, can we document the difference between simple-bus and
simple-mfd clearly?
For example, "Unlike simple-bus, it is legitimate that simple-mfd has
subnodes without reg property"


I think this is typical when "simple-mfd" is used together with "syscon".
The child devices will use regmap of the parent node.
I'd like to be sure this is valid usage.


-- 
Best Regards
Masahiro Yamada