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

[Marek Vasut]

On Thursday, June 12, 2014 at 05:26:50 AM, Simon Glass wrote:
> Hi Marek,
> 
> On 8 June 2014 01:00, Marek Vasut <marex at 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 at 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