RE: [PATCH v7] mfd: syscon: Decouple syscon interface from platform devices
From: Pankaj Dubey
Date: Wed Oct 22 2014 - 07:07:04 EST
Hello Lee,
On Tuesday, October 07, 2014 2:39 PM, Lee Jones wrote,
> On Tue, 30 Sep 2014, Pankaj Dubey wrote:
>
> > Currently a syscon entity can be only registered directly through a
> > platform device that binds to a dedicated syscon driver. However in
> > certain use cases it is desirable to make a device used with another
> > driver a syscon interface provider.
> >
> > For example, certain SoCs (e.g. Exynos) contain system controller
> > blocks which perform various functions such as power domain control,
> > CPU power management, low power mode control, but in addition contain
> > certain IP integration glue, such as various signal masks, coprocessor
> > power control, etc. In such case, there is a need to have a dedicated
> > driver for such system controller but also share registers with other
> > drivers. The latter is where the syscon interface is helpful.
> >
> > In case of DT based platforms, this patch decouples syscon object from
> > syscon platform driver, and allows to create syscon objects first time
> > when it is required by calling of syscon_regmap_lookup_by APIs and
> > keep a list of such syscon objects along with syscon provider
> > device_nodes and regmap handles.
> >
> > For non-DT based platforms, this patch keeps syscon platform driver
> > structure so that syscon can be probed and such non-DT based drivers
> > can use syscon_regmap_lookup_by_pdev API and access regmap handles.
> > Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based,
> > we can completely remove platform driver of syscon, and keep only
> > helper functions to get regmap handles.
> >
> > Suggested-by: Arnd Bergmann <arnd@xxxxxxxx>
> > Suggested-by: Tomasz Figa <tomasz.figa@xxxxxxxxx>
> > Tested-by: Vivek Gautam <gautam.vivek@xxxxxxxxxxx>
> > Tested-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
> > Signed-off-by: Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx>
> > Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
> > Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
> > Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
>
> Applied for v3.19.
I can't see this in 3.18-rc1, as this patch is one of dependency for many of Exynos PMU related patches,
will you please queue this patch for 3.18-rc2, so that already ready to be in patches having this patch as
dependency can be taken in.
Thanks,
Pankaj Dubey
>
> --
> Lee Jones
> Linaro STMicroelectronics Landing Team Lead Linaro.org â Open source software
> for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
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