RE: [PATCH RESEND V4 1/5] clocksource: timer-of: Support getting clock frequency from DT

[Anson Huang]

Hi, Daniel

> Hi Anson,
> 
> why did you resend the series?

Previous patch series has build warning and I did NOT notice, sorry for that,

drivers/clocksource/timer-of.c: In function âtimer_of_initâ:
drivers/clocksource/timer-of.c:185:30: warning: suggest parentheses around comparison in operand of â&â [-Wparentheses]
  if (to->flags & clock_flags == clock_flags)
                              ^

so I resend the patch series with below, sorry for missing mention of the changes in resent patch series.

 +	if ((to->flags & clock_flags) == clock_flags)

Sorry for mail storm...

Thanks,
Anson

> 
> 
> On 02/07/2019 09:55, Anson.Huang@xxxxxxx wrote:
> > From: Anson Huang <Anson.Huang@xxxxxxx>
> >
> > More and more platforms use platform driver model for clock driver, so
> > the clock driver is NOT ready during timer initialization phase, it
> > will cause timer initialization failed.
> >
> > To support those platforms with upper scenario, introducing a new flag
> > TIMER_OF_CLOCK_FREQUENCY which is mutually exclusive with
> > TIMER_OF_CLOCK flag to support getting timer clock frequency from DT's
> > timer node, the property name should be "clock-frequency", then of_clk
> > operations can be skipped.
> >
> > User needs to select either TIMER_OF_CLOCK_FREQUENCY or
> TIMER_OF_CLOCK
> > flag if want to use timer-of driver to initialize the clock rate.
> >
> > Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> > ---
> > Changes since V3:
> > 	- use hardcoded "clock-frequency" instead of adding new variable
> prop_name;
> > 	- add pre-condition check for TIMER_OF_CLOCK and
> TIMER_OF_CLOCK_FREQUENCY, they MUST be exclusive.
> > ---
> >  drivers/clocksource/timer-of.c | 29 +++++++++++++++++++++++++++++
> > drivers/clocksource/timer-of.h |  7 ++++---
> >  2 files changed, 33 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/clocksource/timer-of.c
> > b/drivers/clocksource/timer-of.c index 8054228..858f684 100644
> > --- a/drivers/clocksource/timer-of.c
> > +++ b/drivers/clocksource/timer-of.c
> > @@ -161,11 +161,30 @@ static __init int timer_of_base_init(struct
> device_node *np,
> >  	return 0;
> >  }
> >
> > +static __init int timer_of_clk_frequency_init(struct device_node *np,
> > +					      struct of_timer_clk *of_clk) {
> > +	int ret;
> > +	u32 rate;
> > +
> > +	ret = of_property_read_u32(np, "clock-frequency", &rate);
> > +	if (!ret) {
> > +		of_clk->rate = rate;
> > +		of_clk->period = DIV_ROUND_UP(rate, HZ);
> > +	}
> > +
> > +	return ret;
> > +}
> > +
> >  int __init timer_of_init(struct device_node *np, struct timer_of *to)
> > {
> > +	unsigned long clock_flags = TIMER_OF_CLOCK |
> > +TIMER_OF_CLOCK_FREQUENCY;
> >  	int ret = -EINVAL;
> >  	int flags = 0;
> >
> > +	if ((to->flags & clock_flags) == clock_flags)
> > +		return ret;
> > +
> >  	if (to->flags & TIMER_OF_BASE) {
> >  		ret = timer_of_base_init(np, &to->of_base);
> >  		if (ret)
> > @@ -180,6 +199,13 @@ int __init timer_of_init(struct device_node *np,
> struct timer_of *to)
> >  		flags |= TIMER_OF_CLOCK;
> >  	}
> >
> > +	if (to->flags & TIMER_OF_CLOCK_FREQUENCY) {
> > +		ret = timer_of_clk_frequency_init(np, &to->of_clk);
> > +		if (ret)
> > +			goto out_fail;
> > +		flags |= TIMER_OF_CLOCK_FREQUENCY;
> > +	}
> > +
> >  	if (to->flags & TIMER_OF_IRQ) {
> >  		ret = timer_of_irq_init(np, &to->of_irq);
> >  		if (ret)
> > @@ -201,6 +227,9 @@ int __init timer_of_init(struct device_node *np,
> struct timer_of *to)
> >  	if (flags & TIMER_OF_CLOCK)
> >  		timer_of_clk_exit(&to->of_clk);
> >
> > +	if (flags & TIMER_OF_CLOCK_FREQUENCY)
> > +		to->of_clk.rate = 0;
> > +
> >  	if (flags & TIMER_OF_BASE)
> >  		timer_of_base_exit(&to->of_base);
> >  	return ret;
> > diff --git a/drivers/clocksource/timer-of.h
> > b/drivers/clocksource/timer-of.h index a5478f3..a08e108 100644
> > --- a/drivers/clocksource/timer-of.h
> > +++ b/drivers/clocksource/timer-of.h
> > @@ -4,9 +4,10 @@
> >
> >  #include <linux/clockchips.h>
> >
> > -#define TIMER_OF_BASE	0x1
> > -#define TIMER_OF_CLOCK	0x2
> > -#define TIMER_OF_IRQ	0x4
> > +#define TIMER_OF_BASE			0x1
> > +#define TIMER_OF_CLOCK			0x2
> > +#define TIMER_OF_IRQ			0x4
> > +#define TIMER_OF_CLOCK_FREQUENCY	0x8
> >
> >  struct of_timer_irq {
> >  	int irq;