Re: [PATCH v18 2/8] mfd: simple-mfd-i2c: Add a Kconfig name

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 3/19/22 02:28, Geert Uytterhoeven wrote:
Hi Alistair,

On Sat, Mar 19, 2022 at 3:36 AM Alistair Francis <alistair23@xxxxxxxxx> wrote:
On Tue, Mar 8, 2022 at 8:53 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
Thanks for your patch, which is now commit bae5a4acef67db88
("mfd: simple-mfd-i2c: Add a Kconfig name") in mfd/for-mfd-next.

On Mon, Jan 24, 2022 at 1:24 PM Alistair Francis <alistair@xxxxxxxxxxxxx> wrote:
Add a Kconfig name to the "Simple Multi-Functional Device support (I2C)"
device so that it can be enabled via menuconfig.

Which still does not explain why this would be needed...

Signed-off-by: Alistair Francis <alistair@xxxxxxxxxxxxx>
Acked-for-MFD-by: Lee Jones <lee.jones@xxxxxxxxxx>

--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1188,7 +1188,7 @@ config MFD_SI476X_CORE
           module will be called si476x-core.

  config MFD_SIMPLE_MFD_I2C
-       tristate
+       tristate "Simple Multi-Functional Device support (I2C)"
         depends on I2C
         select MFD_CORE
         select REGMAP_I2C

The help text states:

| This driver creates a single register map with the intention for it
| to be shared by all sub-devices.

Yes, that's what MFD does?

| Once the register map has been successfully initialised, any
| sub-devices represented by child nodes in Device Tree will be
| subsequently registered.

OK...?

Still, no clue about what this driver really does, and why and when
it would be needed.

There is one driver symbol that selects MFD_SIMPLE_MFD_I2C.
There are no driver symbols that depend on this symbol.

If you have a driver in the pipeline that can make use of this,
can't it just select MFD_SIMPLE_MFD_I2C, so the symbol itself can
stay invisible?

My patch "mfd: simple-mfd-i2c: Enable support for the silergy,sy7636a"
allows using this driver for the silergy,sy7636a MFD. So it's nice to
be able to enable and disable it as required.

So after that patch, enabling MFD_SIMPLE_MFD_I2C will enable
support for an ever-growing random bunch of devices, none of which
is described in the help text?
To me, ghat doesn't look like the way to go forward...


I am probably missing something. Why not something like the following ?

config MFD_SY7636A
        tristate "Silergy SY7636A voltage regulator"
        depends on I2C
        select MFD_SIMPLE_MFD_I2C
        help
          Enable support for Silergy SY7636A voltage regulator.

          To enable support for building sub-devices as modules,
          choose M here.


This would be quite similar to MFD_SL28CPLD which essentially does
the same (and, unless I am missing something, doesn't have its own
driver either). Sub-devices would then depend on MFD_SY7636A.

Guenter

Gr{oetje,eeting}s,

                         Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                 -- Linus Torvalds




[Index of Archives]     [LM Sensors]     [Linux Sound]     [ALSA Users]     [ALSA Devel]     [Linux Audio Users]     [Linux Media]     [Kernel]     [Gimp]     [Yosemite News]     [Linux Media]

  Powered by Linux