On 22 September 2014 06:40, Pankaj Dubey <pankaj.dubey@xxxxxxxxxxx> 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 where is can be probed and such non-DT based drivers can use > syscon_regmap_lookup_by_pdev API and get access to regmap handles. > Once all users of "syscon_regmap_lookup_by_pdev" migrated to DT based, > we can completly 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> Hi Pankaj, I wrote a clk driver using syscon and your patch. clk driver uses CLK_OF_DECLARE, btw. It works but I get a '(null): Failed to create debugfs directory' message in the boot log. Tested-by: Joachim Eastwood <manabian@xxxxxxxxx> regards, Joachim Eastwood -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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