Re: [PATCH v7 06/13] pwm: add support for sl28cpld PWM controller

Michael Walle
2020-08-10T07:31:53Z

Am 2020-08-10 09:13, schrieb Lee Jones:
> On Fri, 07 Aug 2020, Michael Walle wrote:
>
>> Hi Uwe, Hi Lee,
>>
>> Am 2020-08-06 10:40, schrieb Uwe Kleine-König:
>> > On Mon, Aug 03, 2020 at 11:35:52AM +0200, Michael Walle wrote:
>> > > diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
>> > > index 7dbcf6973d33..a0d50d70c3b9 100644
>> > > --- a/drivers/pwm/Kconfig
>> > > +++ b/drivers/pwm/Kconfig
>> > > @@ -428,6 +428,16 @@ config PWM_SIFIVE
>> > > To compile this driver as a module, choose M here: the module
>> > > will be called pwm-sifive.
>> > >
>> > > +config PWM_SL28CPLD
>> > > + tristate "Kontron sl28cpld PWM support"
>> > > + select MFD_SIMPLE_MFD_I2C
>> >
>> > Is it sensible to present this option to everyone? Maybe
>> >
>> > depends on SOME_SYMBOL_ONLY_TRUE_ON_SL28CPLD || COMPILE_TEST
>>
>> Because there is now no real MFD driver anymore, there is also
>> no symbol for that. The closest would be ARCH_ARM64 but I don't
>> think that is a good idea.
>>
>> Lee, what do you think about adding a symbol to the MFD, which
>> selects MFD_SIMPLE_MFD_I2C but doesn't enable any C modules?
>>
>> I.e.
>> config MFD_SL28CPLD
>> tristate "Kontron sl28cpld"
>> select MFD_SIMPLE_MFD_I2C
>> help
>> Say yes here to add support for the Kontron sl28cpld board
>> management controller.
>>
>> Then all the other device driver could depend on the MFD_SL28CPLD
>> symbol.
>
> You want to add a virtual symbol to prevent having to present a real
> one? How is that a reasonable solution?

(1) Its a symbol on which all sl28cpld will depend on. Thus they will
all be hidden if that is not set.
(2) the drivers itself wouldn't need to depend on MFD_SIMPLE_MFD_I2C,
which is more correct, because they don't have anything to do with
i2c.

-michael