[U-Boot] [PATCH v4 09/15] dm: Cast away the const-ness of the global_data pointer

Marek Vasut
2014-06-17T23:42:17Z

On Thursday, June 12, 2014 at 05:26:50 AM, Simon Glass wrote:
> Hi Marek,
>
> On 8 June 2014 01:00, Marek Vasut <marex@denx.de> wrote:
> > On Friday, June 06, 2014 at 09:13:26 PM, Simon Glass wrote:
> >> In a very few cases we need to adjust the driver model root device, such
> >> as when setting it up at initialisation. Add a macro to make this
> >> easier.
> >>
> >> Signed-off-by: Simon Glass <sjg@chromium.org>
> >> ---
> >
> > [...]
> >
> >> - ret = device_bind_by_name(NULL, &root_info, &gd->dm_root);
> >> + ret = device_bind_by_name(NULL, &root_info, &DM_ROOT());
> >
> > [...]
> >
> >> +/* Cast away any volatile pointer */
> >> +#define DM_ROOT() (((gd_t *)gd)->dm_root)
> >> +#define DM_UCLASS_ROOT() (((gd_t *)gd)->uclass_root)
> >
> > Can you implement this "DM_ROOT()" macro as a function instead ? I
> > believe that'd be much nicer , would have typechecking etc., usual
> > stuff.
>
> I had a look at this. I don't see how I can do it, but you might have
> ideas.
>
> In this function call I need to pass a pointer without its const bit.
> I made it const since nothing should change the dm root except driver
> model itself.

All right, I will just be doing a little guesswork here. Shall you not have some
functions to change the DM root then instead of exposing the DM root ? Such
functions shall not be exported publicly , but available via separate header
file too ?

Sorry, I might be completely wrong.

Best regards,
Marek Vasut