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

From: Michael Walle
Date: Thu Aug 13 2020 - 03:09:47 EST


Am 2020-08-10 09:31, schrieb Michael Walle:
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.

Lee, would you accept such a symbol? Otherwise, I'd leave it as is.

-michael