From: Anson Huang <[email protected]>
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, 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,
and the corresponding clock name or property name needs to be specified.
Signed-off-by: Anson Huang <[email protected]>
---
New patch:
- Add new flag of TIMER_OF_CLOCK_FREQUENCY, mutually exclusive with TIMER_OF_CLOCK, to support
getting clock frequency from DT directly;
- Add prop_name to of_timer_clk structure, if using TIMER_OF_CLOCK_FREQUENCY flag, user needs
to pass the property name for timer-of driver to get clock frequency from DT, this is to avoid
the couple of timer-of driver and DT, so timer-of driver does NOT use a fixed property name.
---
drivers/clocksource/timer-of.c | 23 +++++++++++++++++++++++
drivers/clocksource/timer-of.h | 8 +++++---
2 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
index 8054228..c91a8b6 100644
--- a/drivers/clocksource/timer-of.c
+++ b/drivers/clocksource/timer-of.c
@@ -161,6 +161,21 @@ 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, of_clk->prop_name, &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)
{
int ret = -EINVAL;
@@ -178,6 +193,11 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
if (ret)
goto out_fail;
flags |= TIMER_OF_CLOCK;
+ } else 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) {
@@ -201,6 +221,9 @@ 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..f1a083e 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;
@@ -26,6 +27,7 @@ struct of_timer_base {
struct of_timer_clk {
struct clk *clk;
const char *name;
+ const char *prop_name;
int index;
unsigned long rate;
unsigned long period;
--
2.7.4
Hi Anson,
thanks for taking care of adding the clock-frequency handling in the
timer-of.
On 28/06/2019 05:30, [email protected] wrote:
> From: Anson Huang <[email protected]>
>
> 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, 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,
> and the corresponding clock name or property name needs to be specified.
>
> Signed-off-by: Anson Huang <[email protected]>
> ---
> New patch:
> - Add new flag of TIMER_OF_CLOCK_FREQUENCY, mutually exclusive with TIMER_OF_CLOCK, to support
> getting clock frequency from DT directly;
> - Add prop_name to of_timer_clk structure, if using TIMER_OF_CLOCK_FREQUENCY flag, user needs
> to pass the property name for timer-of driver to get clock frequency from DT, this is to avoid
> the couple of timer-of driver and DT, so timer-of driver does NOT use a fixed property name.
> ---
> drivers/clocksource/timer-of.c | 23 +++++++++++++++++++++++
> drivers/clocksource/timer-of.h | 8 +++++---
> 2 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/clocksource/timer-of.c b/drivers/clocksource/timer-of.c
> index 8054228..c91a8b6 100644
> --- a/drivers/clocksource/timer-of.c
> +++ b/drivers/clocksource/timer-of.c
> @@ -161,6 +161,21 @@ 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, of_clk->prop_name, &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)
> {
> int ret = -EINVAL;
> @@ -178,6 +193,11 @@ int __init timer_of_init(struct device_node *np, struct timer_of *to)
> if (ret)
> goto out_fail;
> flags |= TIMER_OF_CLOCK;
> + } else 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;
> }
/* Pre-condition */
if (to->flags & (TIMER_OF_CLOCK | TIMER_OF_CLOCK_FREQUENCY))
return -EINVAL;
[ ... ]
if (to->flags & TIMER_OF_CLOCK) {
}
if (to->flags & TIMER_OF_CLOCK_FREQUENCY) {
}
> if (to->flags & TIMER_OF_IRQ) {
> @@ -201,6 +221,9 @@ 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..f1a083e 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;
> @@ -26,6 +27,7 @@ struct of_timer_base {
> struct of_timer_clk {
> struct clk *clk;
> const char *name;
> + const char *prop_name;
For the moment, keep it hardcoded with "clock-frequency" directly in the
function.
> int index;
> unsigned long rate;
> unsigned long period;
>
--
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Hi, Daniel
> Subject: Re: [PATCH V3 1/5] clocksource: timer-of: Support getting clock
> frequency from DT
>
>
> Hi Anson,
>
> thanks for taking care of adding the clock-frequency handling in the timer-of.
Sure.
>
> On 28/06/2019 05:30, [email protected] wrote:
> > From: Anson Huang <[email protected]>
> >
> > 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,
> > 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, and
> > the corresponding clock name or property name needs to be specified.
> >
> > Signed-off-by: Anson Huang <[email protected]>
> > ---
> > New patch:
> > - Add new flag of TIMER_OF_CLOCK_FREQUENCY, mutually exclusive
> with TIMER_OF_CLOCK, to support
> > getting clock frequency from DT directly;
> > - Add prop_name to of_timer_clk structure, if using
> TIMER_OF_CLOCK_FREQUENCY flag, user needs
> > to pass the property name for timer-of driver to get clock frequency
> from DT, this is to avoid
> > the couple of timer-of driver and DT, so timer-of driver does NOT
> use a fixed property name.
> > ---
> > drivers/clocksource/timer-of.c | 23 +++++++++++++++++++++++
> > drivers/clocksource/timer-of.h | 8 +++++---
> > 2 files changed, 28 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/clocksource/timer-of.c
> > b/drivers/clocksource/timer-of.c index 8054228..c91a8b6 100644
> > --- a/drivers/clocksource/timer-of.c
> > +++ b/drivers/clocksource/timer-of.c
> > @@ -161,6 +161,21 @@ 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, of_clk->prop_name, &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)
> > {
> > int ret = -EINVAL;
> > @@ -178,6 +193,11 @@ int __init timer_of_init(struct device_node *np,
> struct timer_of *to)
> > if (ret)
> > goto out_fail;
> > flags |= TIMER_OF_CLOCK;
> > + } else 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;
> > }
>
> /* Pre-condition */
>
> if (to->flags & (TIMER_OF_CLOCK | TIMER_OF_CLOCK_FREQUENCY))
> return -EINVAL;
>
> [ ... ]
>
> if (to->flags & TIMER_OF_CLOCK) {
> }
>
> if (to->flags & TIMER_OF_CLOCK_FREQUENCY) { }
>
Ah, make sense, they are exclusive, will add it in next version.
> > if (to->flags & TIMER_OF_IRQ) {
> > @@ -201,6 +221,9 @@ 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..f1a083e 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;
> > @@ -26,6 +27,7 @@ struct of_timer_base { struct of_timer_clk {
> > struct clk *clk;
> > const char *name;
> > + const char *prop_name;
>
> For the moment, keep it hardcoded with "clock-frequency" directly in the
> function.
OK, then I will NOT add any dt-binding for this property. The reason to use prop_name
instead of hardcode is I don't want to create a binding doc just for this property.
Thanks,
Anson.