[U-Boot] [PATCH v2 1/9] dm: Use dm.h header when driver mode is used

[Simon Glass]

Hi Masahiro,

On 10 May 2017 at 20:12, Masahiro Yamada <yamada.masahiro at socionext.com> wrote:
> Hi Simon,
>
>
> 2017-05-11 6:43 GMT+09:00 Tom Rini <trini at konsulko.com>:
>> On Mon, May 01, 2017 at 09:18:44AM -0600, Simon Glass wrote:
>>
>>> This header includes things that are needed to make driver build. Adjust
>>> existing users to include that always, even if other dm/ includes are
>>> present
>>>
>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>
>> Reviewed-by: Tom Rini <trini at konsulko.com>
>>
>
> I'd say this is a bad idea.
> I believe .c files should include headers that are really necessary.
>
> Mostly, drivers need only dm/device.h, but this commit
> requires additional parse of dm/uclass.h and dm/platdata.h.
>
> Rather, it is better to deprecate dm.h.
>
> Its concept is DM common header that you force drivers to include
> where some in them may not be necessary.

I did consider this right at the start but I think it is too painful
for users. There are only a few files that we pull in so the overhead
is not great. It avoids having to add new headers because some other
function is used.

One option might be to define all the structs in one header, since
those are the things that are really painful to figure out. We could
then make the function name prefixes fully consistent with the header
file name (mostly they are, but see lists.h and root.h). That would
make it easier.

>
> It is a similar idea to include/common.h,
> which is one of the biggest design mistakes in U-Boot.

We have been slowing pulling things out of common.h - see for example
mapmem.h and vsprint.h. We also have a lot of files in include/ which
really should be arch-specific.

But in any case I think common.h is useful just to include the
configuration and some common declarations (like global_data). The
problem is that it has too much in it.

Regards,
Simon