Re: [PATCH v2 14/18] serial: intel: Add CCF support

[Wu, Songjun]

On 8/3/2018 1:56 PM, Greg Kroah-Hartman wrote:
> On Fri, Aug 03, 2018 at 11:02:33AM +0800, Songjun Wu wrote:
> > Previous implementation uses platform-dependent API to get the clock.
> > Those functions are not available for other SoC which uses the same IP.
> > The CCF (Common Clock Framework) have an abstraction based APIs for
> > clock. In future, the platform specific code will be removed when the
> > legacy soc use CCF as well.
> > Change to use CCF APIs to get clock and rate. So that different SoCs
> > can use the same driver.
> >
> > Signed-off-by: Songjun Wu <songjun.wu@xxxxxxxxxxxxxxx>
> > ---
> >
> > Changes in v2: None
> >
> >   drivers/tty/serial/lantiq.c | 11 +++++++++++
> >   1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/tty/serial/lantiq.c b/drivers/tty/serial/lantiq.c
> > index 36479d66fb7c..35518ab3a80d 100644
> > --- a/drivers/tty/serial/lantiq.c
> > +++ b/drivers/tty/serial/lantiq.c
> > @@ -26,7 +26,9 @@
> >   #include <linux/clk.h>
> >   #include <linux/gpio.h>
> >   
> > +#ifdef CONFIG_LANTIQ
> >   #include <lantiq_soc.h>
> > +#endif
> That is never how you do this in Linux, you know better.
>
> Please go and get this patchset reviewed and signed-off-by from other
> internal Intel kernel developers before resending it next time.  It is
> their job to find and fix your basic errors like this, not ours.
Thank you for your comment.
Actually, we have discussed this issue internally.
We put the reason why we use "#ifdef CONFIG_LANTIQ" preprocessor in commit
message in "[PATCH v2 08/18] serial: intel: Get serial id from dts".
Please refer the commit message below.

"#ifdef CONFIG_LANTIQ" preprocessor is used because LTQ_EARLY_ASC
macro is defined in lantiq_soc.h.
lantiq_soc.h is in arch path for legacy product support.

arch/mips/include/asm/mach-lantiq/xway/lantiq_soc.h

If "#ifdef preprocessor" is changed to
"if (IS_ENABLED(CONFIG_LANTIQ))", when CONFIG_LANTIQ is not enabled,
code using LTQ_EARLY_ASC is compiled.
Compilation will fail for no LTQ_EARLY_ASC defined.