Re: [PATCH 1/4] dt-bindings: Document new common property: has-inaccessible-regs

[Richard Weinberger <richard@nod.at>]

----- Ursprüngliche Mail -----
> Von: "Krzysztof Kozlowski" <krzk@kernel.org>
>>>> What solution do you propose?
>>>> Splitting reg = <0x0 0x1400> into many tiny fractions and not using an mfd
>>>> anymore?
>>>
>>> Fix the driver. In your case, the syscon driver.
>> 
>> Please help me to understand what the desired behavior of the driver is.
>> 
>> Currently syscon creates one regmap for everything and passes this regmap
>> to the individual syscon users.
>> These users have to know what offset within the regmap is their playground.
>> If I understand correctly, it would be better if every syscon user would
>> register their own regmap?
> 
> I don't think so. This device driver, so the syscon, creates the regmap
> and knows EXACTLY which registers are valid or not. It is not
> responsibility of the consumer to tell the syscon what this syscon is.
> Syscon knows that...

How to configure this in syscon?
AFAIK it takes only a single reg property.
Are you suggesting to add many more syscon nodes to the DT to skip the holes?

Currently the scm_conf@0 DT node defines the first 0x1400 bytes
of the CTRL_MODULE_CORE register[0].

Reading from register 0x180 triggers an async data abort here.
The manual describes it as "RESERVED" of type "R".
Lots of other offsets in CTRL_MODULE_CORE are reserved, but reading works.

Long story short, please tell me how to model it in DT and I'll do so.

Thanks,
//richard

[0] https://www.ti.com/lit/ug/spruhz6l/spruhz6l.pdf 18.5.2.1 CTRL_MODULE_CORE Register Summary