Re: [PATCH net-next v4 5/8] mfd: zl3073x: Add functions to work with register mailboxes

[Ivan Vecera <ivecera@redhat.com>]

On 24. 04. 25 9:29 odp., Andrew Lunn wrote:
>> Yes, PHC (PTP) sub-driver is using mailboxes as well. Gpio as well for some
>> initial configuration.
> 
> O.K, so the mailbox code needs sharing. The question is, where do you
> put it.

This is crucial question... If I put the MB API into DPLL sub-driver
then PTP sub-driver will depend on it. Potential GPIO sub-driver as
well.

There could be some special library module to provide this for
sub-drivers but is this what we want? And if so where to put it?

>>> The mutex needs to be shared, but that could be in the common data
>>> structure.
>>
>> Do you mean that sub-device would access mutexes placed in zl3073x_dev which
>> is parent (mfd) driver structure?
> 
> Yes.

So, some helper functions for taking and releasing lock... The v4
approach uses (will use) one mutex per mailbox type but one mutex for
MB access is also sufficient.

Ivan