Re: [PATCH 07/12] mfd: syscon: Consider platform data a regmap config name

[Pawel Moll <pawel.moll@arm.com>]

On Wed, 2014-02-12 at 08:26 +0000, Lee Jones wrote:
> > > Use the device platform data as a regmap config
> > > name. This is particularly useful in the regmap
> > > debugfs when there is more than one syscon device
> > > registered, to distinguish the register blocks.
> > > 
> > > Cc: Samuel Ortiz <sameo@linux.intel.com>
> > > Cc: Lee Jones <lee.jones@linaro.org>
> > > Signed-off-by: Pawel Moll <pawel.moll@arm.com>
> > > ---
> > ...
> > > syscon_regmap_config.max_register = res->end - res->start - 3;
> > > +	syscon_regmap_config.name = dev_get_platdata(&pdev->dev);
> > 
> > Is dev_name(&pdev->dev) can be used for such purpose?
> 
> Yes of course.
> 
> Either use the automatically generated name or over-ride with
> dev->init_name prior to registration or call dev_set_name()
> manually. Then retrieve with Alexander's suggestion.
> 
> Is there any technical reason why this is not possible with your
> implementation?

Hold on, guys. Let me just point out that we're talking "non-DT"
platform devices here (either statically defined struct
platform_device-s or - my case - the MFD cells).

In this case device/driver matching relies completely on device name.
Either the pdev->name must be identical (strcmp) to pdrv->name, or the
pdev->name must be identical (strcmp again) to one of the pdev->id_table
entries. See platform_match() in driver/base/platform.c for more
details.

Therefore the dev_name(&pdev->dev) on a non-DT-originating sysconf
devince will always return "sysconf.*", unless you're ready to maintain
a growing syscon_ids[] list. If so, I will have to add three entries
there ("sys_id", "sys_misc" and "sys_procid"). I hope you are not
seriously considering this idea :-) After all that's what the
platform_data was invented for.

Pawel