[U-Boot] [PATCH v3 00/54] dm: Introduce new driver model uclasses

[Simon Glass]

Hi Tom,

On 30 June 2015 at 14:31, Tom Rini <trini at konsulko.com> wrote:
> On Tue, Jun 30, 2015 at 01:10:45PM -0700, York Sun wrote:
>>
>>
>> On 06/30/2015 12:01 PM, Tom Rini wrote:
>> > On Tue, Jun 30, 2015 at 11:42:41AM -0700, York Sun wrote:
>> >>
>> >>
>> >> On 06/30/2015 11:33 AM, Simon Glass wrote:
>> >>> Hi York,
>> >>>
>> >>> On 30 June 2015 at 10:08, York Sun <yorksun at freescale.com> wrote:
>> >>>> Simon,
>> >>>>
>> >>>> Does the dm force using device tree? I was reviewing a patch set regarding SPI
>> >>>> and found OF_CONTROL has to be selected in order to get the driver model happy.
>> >>>>
>> >>>> My understanding of the driver model is both device tree and platform data are
>> >>>> allowed, like Linux. Is that still true?
>> >>>
>> >>> For buses you need device tree. I was rather hoping that we could
>> >>> avoid platform data on platforms that have device tree. What is the
>> >>> point?
>> >>>
>> >>
>> >> Simon,
>> >>
>> >> It happens on a platform not using device tree, but DM will be used.
>> >>
>> >> I prefer DM to have both, rather than being forced to use device tree, unless we
>> >> are going to enforce using device tree on all new platforms. Since device tree
>> >> is still an option, I feel it is best to support platform data, like Linux
>> >> drivers do.
>> >
>> > Well, to what end?  My recollection is that in short, the kernel has
>> > both since platform data predates device tree (and converting platform
>> > data to device tree is still a thing that happens).  But we're trying to
>> > skip that intermediate step.  Are there platforms where you do not plan
>> > to use a device tree, ever?
>> >
>>
>> Tom,
>>
>> I am not against using device tree at all. It is more dynamic and flexible. But
>> I don't see any indication that we favor device tree over pdata (except in the
>> code). If we are skipping pdata for new drivers, a clear message will be
>> helpful. That's what I am trying to get clarification.
>
> OK.  I think we'd agreed to that at ELC-E last year and it might have
> been in a few here-and-there emails but it's worth spelling out
> somewhere.
>
> Hey Simon?  doc/driver-model/README.txt has a pdata example, so maybe
> the answer here is it's time to update README.txt in a few ways :)

I'll prepare a patch.

Regards,
Simon