Re: [PATCH 18/20] clocksource / acpi: Add macroCLOCKSOURCE_ACPI_DECLARE

[Mark Rutland]

On Wed, Jan 22, 2014 at 08:26:50AM +0000, Linus Walleij wrote:
> On Fri, Jan 17, 2014 at 1:25 PM, Hanjun Guo <hanjun.guo@xxxxxxxxxx> wrote:
> 
> > From: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx>
> >
> > This macro does the same job as CLOCKSOURCE_OF_DECLARE. The device
> > name from the ACPI timer table is matched with all the registered
> > timer controllers and matching initialisation routine is invoked.
> >
> > Signed-off-by: Amit Daniel Kachhap <amit.daniel@xxxxxxxxxxx>
> > Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> 
> Actually I have a fat patch renaming CLOCKSOURCE_OF_DECLARE()
> to TIMER_OF_DECLARE() and I think this macro, if needed, should
> be named TIMER_ACPI_DECLARE().
> 
> The reason is that "clocksource" is a Linux-internal name and this
> macro pertains to the hardware name in respective system
> description type.
> 
> > +#ifdef CONFIG_ACPI
> > +#define CLOCKSOURCE_ACPI_DECLARE(name, compat, fn)                     \
> > +       static const struct acpi_device_id __clksrc_acpi_table_##name   \
> > +               __used __section(__clksrc_acpi_table)                   \
> > +                = { .id = compat,                              \
> > +                    .driver_data = (kernel_ulong_t)fn }
> > +#else
> > +#define CLOCKSOURCE_ACPI_DECLARE(name, compat, fn)
> > +#endif
> 
> This hammers down the world to compile one binary for ACPI
> and one binary for device tree. Maybe that's fine, I don't know.

How does it do that?

As far as I could tell CONFIG_ACPI and CONFIG_OF are not mutually
exclusive, and this just means that we only build the datastructures for
matching from ACPI when CONFIG_ACPI is enabled.

Have I missed something?

I definitely don't want to see mutually exclusive ACPI and DT support.

Cheers,
Mark.
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