Re: [PATCH 1/1] dt-bindings: clock: Add new OST support for the upcoming new driver.

[Zhou Yanjie]

Hi Rob,

在 2020/10/13 下午9:29, Rob Herring 写道:
> On Thu, Oct 08, 2020 at 02:14:07AM +0800, 周琰杰 (Zhou Yanjie) wrote:
> > The new OST has one global timer and two or four percpu timers, so there will be three
> > combinations in the upcoming new OST driver: the original GLOBAL_TIMER + PERCPU_TIMER,
> > the new GLOBAL_TIMER + PERCPU_TIMER0/1 and GLOBAL_TIMER + PERCPU_TIMER0/1/2/3, For this,
> > add the macro definition about OST_CLK_PERCPU_TIMER0/1/2/3. And in order to ensure that
> > all the combinations work normally, the original ABI values of OST_CLK_PERCPU_TIMER and
> > OST_CLK_GLOBAL_TIMER need to be exchanged to ensure that in any combinations, the clock
> > can be registered (by calling clk_hw_register()) from index 0.
> Wrap lines at <80 characters.


Sorry, I will fix it in the next version.


> > I'm sure that exchanging the ABI values of OST_CLK_PERCPU_TIMER and OST_CLK_GLOBAL_TIMER
> > will not affect the existing related drivers and the SoCs whitch using these drivers, so
> > we should be able to exchange them safely.
> Why exactly is this okay?


These definitions are currently only used in two places, one is when 
using "assigned-clocks" to configure the clock in the DTS file; the 
other is when registering the clock in the sysost driver. When 
exchanging the values of "OST_CLK_PERCPU_TIMER" and 
"OST_CLK_GLOBAL_TIMER", the corresponding values will be changed 
synchronously when the clock is driven to register and when the clock is 
configured through "assigned-clocks". Therefore, there is no situation 
that causes the wrong clock to the configured. And it has been tested on 
X1000 and X1000 and X1830 SoCs, all working fine.

I'm sorry because I didn't think carefully when writing this header 
file, and caused the current trouble.


Thanks and best regards!


> > Tested-by: 周正 (Zhou Zheng) <sernia.zhou@xxxxxxxxxxx>
> > Signed-off-by: 周琰杰 (Zhou Yanjie) <zhouyanjie@xxxxxxxxxxxxxx>
> > ---
> >   include/dt-bindings/clock/ingenic,sysost.h | 10 +++++++---
> >   1 file changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/include/dt-bindings/clock/ingenic,sysost.h b/include/dt-bindings/clock/ingenic,sysost.h
> > index 9ac88e90babf..063791b01ab3 100644
> > --- a/include/dt-bindings/clock/ingenic,sysost.h
> > +++ b/include/dt-bindings/clock/ingenic,sysost.h
> > @@ -1,12 +1,16 @@
> >   /* SPDX-License-Identifier: GPL-2.0 */
> >   /*
> > - * This header provides clock numbers for the ingenic,tcu DT binding.
> > + * This header provides clock numbers for the Ingenic OST DT binding.
> >    */
> >   
> >   #ifndef __DT_BINDINGS_CLOCK_INGENIC_OST_H__
> >   #define __DT_BINDINGS_CLOCK_INGENIC_OST_H__
> >   
> > -#define OST_CLK_PERCPU_TIMER	0
> > -#define OST_CLK_GLOBAL_TIMER	1
> > +#define OST_CLK_PERCPU_TIMER	1
> > +#define OST_CLK_GLOBAL_TIMER	0
> > +#define OST_CLK_PERCPU_TIMER0	1
> > +#define OST_CLK_PERCPU_TIMER1	2
> > +#define OST_CLK_PERCPU_TIMER2	3
> > +#define OST_CLK_PERCPU_TIMER3	4
> >   
> >   #endif /* __DT_BINDINGS_CLOCK_INGENIC_OST_H__ */
> > --
> > 2.11.0