Re: [PATCH v3 03/16] mfd: mfd-core: match device tree node against reg property

[Michael Walle]

Am 2020-06-08 16:24, schrieb Lee Jones:
> On Mon, 25 May 2020, Michael Walle wrote:
> > Am 2020-05-15 12:28, schrieb Lee Jones:
> > > On Thu, 30 Apr 2020, Michael Walle wrote:
> > >
> > > > Hi Lee,
> > > >
> > > > Am 2020-04-23 19:45, schrieb Michael Walle:
> > > > > There might be multiple children with the device tree compatible, for
> > > > > example if a MFD has multiple instances of the same function. In this
> > > > > case only the first is matched and the other children get a wrong
> > > > > of_node reference.
> > > > > Add a new option to match also against the unit address of the child
> > > > > node. Additonally, a new helper OF_MFD_CELL_REG is added.
>
> [...]
>
> > > > > diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
> > > > > index d01d1299e49d..c2c0ad6b14f3 100644
> > > > > --- a/include/linux/mfd/core.h
> > > > > +++ b/include/linux/mfd/core.h
> > > > > @@ -13,8 +13,11 @@
> > > > >  #include <linux/platform_device.h>
> > > > >
> > > > >  #define MFD_RES_SIZE(arr) (sizeof(arr) / sizeof(struct resource))
> > > > > +#define MFD_OF_REG_VALID	BIT(31)
> > >
> > > What about 64bit platforms?
> >
> > The idea was to have this as a logical number. I.e. for now you may 
> > only
> > have one subdevice per unique compatible string. In fact, if you have 
> > a
> > look at the ab8500.c, there are multiple "stericsson,ab8500-pwm"
> > subdevices. But there is only one DT node for all three of it. I guess
> > this works as long as you don't use phandles to reference the pwm node
> > in the device tree. Or you don't want to use device tree properties
> > per subdevice (for example the "timeout-sec" of a watchdog device).
>
> This is not a good example, as the "stericsson,ab8500-pwm" is
> legitimate.  Here we are registering 3 potential devices, but only
> instantiating 1 of them.

Mh?

static const struct mfd_cell ab8500_devs[] = {
..
       OF_MFD_CELL("ab8500-pwm",
                    NULL, NULL, 0, 1, "stericsson,ab8500-pwm"),
        OF_MFD_CELL("ab8500-pwm",
                    NULL, NULL, 0, 2, "stericsson,ab8500-pwm"),
        OF_MFD_CELL("ab8500-pwm",
                    NULL, NULL, 0, 3, "stericsson,ab8500-pwm"),
..
}

And in pwm-ab8500.c there are three offsets based on the pdev->id.

Am I missing something here?

--
-michael