[PATCH] [RFC] ARM: shmobile: Enable shmobile Runtime PM from MSTP clock driver

[PATCH] [RFC] ARM: shmobile: Enable shmobile Runtime PM from MSTP clock driver

[Geert Uytterhoeven]

On shmobile multi-platform using the Common Clock Framework, enable
shmobile Runtime PM from the MSTP clock driver, to make sure the bus clocks
are enabled for all devices.

On ARCH_SHMOBILE_LEGACY, this is done unconditionally, from the shmobile
Runtime PM code itself.
On ARCH_SHMOBILE_MULTI, this was missing, leading to disabled clocks,
depending on implicit reset state or on the bootloader.

The external declaration of sh_pm_runtime_enable() in clk-mstp.c is
needed because arch/arm/mach-shmobile/include/mach/common.h can't be
included from driver code.

More calls to sh_pm_runtime_enable() will have to be added to other gate
clock drivers, when the corresponding SoC platform code is converted to
multi-platform and CCF.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This applies on top of patches 4-7 (1-3 have been applied by Simon) of
series "[PATCH v2 00/17] ARM: shmobile: Enable drivers/sh/pm_runtime.c on
multi-platform]".

 drivers/clk/shmobile/clk-mstp.c |    3 +++
 drivers/sh/pm_runtime.c         |   20 ++++++++++++--------
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/shmobile/clk-mstp.c b/drivers/clk/shmobile/clk-mstp.c
index 2e3c08fff173..da2e6dcf8fed 100644
--- a/drivers/clk/shmobile/clk-mstp.c
+++ b/drivers/clk/shmobile/clk-mstp.c
@@ -161,6 +161,9 @@ static void __init cpg_mstp_clocks_init(struct device_node *np)
 	struct mstp_clock_group *group;
 	struct clk **clks;
 	unsigned int i;
+	extern void sh_pm_runtime_enable(void);
+
+	sh_pm_runtime_enable();
 
 	group = kzalloc(sizeof(*group), GFP_KERNEL);
 	clks = kmalloc(MSTP_MAX_CLOCKS * sizeof(*clks), GFP_KERNEL);
diff --git a/drivers/sh/pm_runtime.c b/drivers/sh/pm_runtime.c
index 3ec047ac1ff4..59d8b5fd558e 100644
--- a/drivers/sh/pm_runtime.c
+++ b/drivers/sh/pm_runtime.c
@@ -75,20 +75,24 @@ static struct pm_clk_notifier_block platform_bus_notifier = {
 	.con_ids = { NULL, },
 };
 
-static bool default_pm_on;
+#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE_LEGACY)
+bool default_pm_on = true;
+#else
+bool default_pm_on;
+#endif
 
-int __init sh_pm_runtime_init(void)
+void __init sh_pm_runtime_enable(void)
 {
-	if (default_pm_on)
-		return 0;
-
 	default_pm_on = true;
-	pm_clk_add_notifier(&platform_bus_type, &platform_bus_notifier);
+}
+
+static int __init sh_pm_runtime_init(void)
+{
+	if (default_pm_on)
+		pm_clk_add_notifier(&platform_bus_type, &platform_bus_notifier);
 	return 0;
 }
-#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE_LEGACY)
 core_initcall(sh_pm_runtime_init);
-#endif
 
 static int __init sh_pm_runtime_late_init(void)
 {
-- 
1.7.9.5

Re: [PATCH] [RFC] ARM: shmobile: Enable shmobile Runtime PM from MSTP clock driver

[Simon Horman]

On Fri, Apr 25, 2014 at 06:58:44PM +0200, Geert Uytterhoeven wrote:
> On shmobile multi-platform using the Common Clock Framework, enable
> shmobile Runtime PM from the MSTP clock driver, to make sure the bus clocks
> are enabled for all devices.
> 
> On ARCH_SHMOBILE_LEGACY, this is done unconditionally, from the shmobile
> Runtime PM code itself.
> On ARCH_SHMOBILE_MULTI, this was missing, leading to disabled clocks,
> depending on implicit reset state or on the bootloader.
> 
> The external declaration of sh_pm_runtime_enable() in clk-mstp.c is
> needed because arch/arm/mach-shmobile/include/mach/common.h can't be
> included from driver code.
> 
> More calls to sh_pm_runtime_enable() will have to be added to other gate
> clock drivers, when the corresponding SoC platform code is converted to
> multi-platform and CCF.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> This applies on top of patches 4-7 (1-3 have been applied by Simon) of
> series "[PATCH v2 00/17] ARM: shmobile: Enable drivers/sh/pm_runtime.c on
> multi-platform]".
> 
>  drivers/clk/shmobile/clk-mstp.c |    3 +++
>  drivers/sh/pm_runtime.c         |   20 ++++++++++++--------
>  2 files changed, 15 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/clk/shmobile/clk-mstp.c b/drivers/clk/shmobile/clk-mstp.c
> index 2e3c08fff173..da2e6dcf8fed 100644
> --- a/drivers/clk/shmobile/clk-mstp.c
> +++ b/drivers/clk/shmobile/clk-mstp.c
> @@ -161,6 +161,9 @@ static void __init cpg_mstp_clocks_init(struct device_node *np)
>  	struct mstp_clock_group *group;
>  	struct clk **clks;
>  	unsigned int i;
> +	extern void sh_pm_runtime_enable(void);
> +
> +	sh_pm_runtime_enable();
>  
>  	group = kzalloc(sizeof(*group), GFP_KERNEL);
>  	clks = kmalloc(MSTP_MAX_CLOCKS * sizeof(*clks), GFP_KERNEL);
> diff --git a/drivers/sh/pm_runtime.c b/drivers/sh/pm_runtime.c
> index 3ec047ac1ff4..59d8b5fd558e 100644
> --- a/drivers/sh/pm_runtime.c
> +++ b/drivers/sh/pm_runtime.c
> @@ -75,20 +75,24 @@ static struct pm_clk_notifier_block platform_bus_notifier = {
>  	.con_ids = { NULL, },
>  };
>  
> -static bool default_pm_on;
> +#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE_LEGACY)
> +bool default_pm_on = true;
> +#else
> +bool default_pm_on;
> +#endif

I wonder if there is some way we can get the compiler
to optimise out code in the case of default_pm_on = false,
perhaps by using IS_ENABLED() in conjunction with a Kconfig variable.

> -int __init sh_pm_runtime_init(void)
> +void __init sh_pm_runtime_enable(void)
>  {
> -	if (default_pm_on)
> -		return 0;
> -
>  	default_pm_on = true;
> -	pm_clk_add_notifier(&platform_bus_type, &platform_bus_notifier);
> +}
> +
> +static int __init sh_pm_runtime_init(void)
> +{
> +	if (default_pm_on)
> +		pm_clk_add_notifier(&platform_bus_type, &platform_bus_notifier);
>  	return 0;
>  }
> -#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE_LEGACY)
>  core_initcall(sh_pm_runtime_init);
> -#endif
>  
>  static int __init sh_pm_runtime_late_init(void)
>  {
> -- 
> 1.7.9.5
> 

Re: [PATCH] [RFC] ARM: shmobile: Enable shmobile Runtime PM from MSTP clock driver

[Geert Uytterhoeven]

Hi Simon,

On Mon, Apr 28, 2014 at 2:10 AM, Simon Horman <horms@verge.net.au> wrote:
>> --- a/drivers/sh/pm_runtime.c
>> +++ b/drivers/sh/pm_runtime.c
>> @@ -75,20 +75,24 @@ static struct pm_clk_notifier_block platform_bus_notifier = {
>>       .con_ids = { NULL, },
>>  };
>>
>> -static bool default_pm_on;
>> +#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE_LEGACY)
>> +bool default_pm_on = true;
>> +#else
>> +bool default_pm_on;
>> +#endif
>
> I wonder if there is some way we can get the compiler
> to optimise out code in the case of default_pm_on = false,
> perhaps by using IS_ENABLED() in conjunction with a Kconfig variable.

What's the use case of that?

This code is compiled only if SUPERH || ARCH_SHMOBILE_LEGACY ||
ARCH_SHMOBILE_MULTIPLATORM.
If should always be used when running on shmobile.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH] [RFC] ARM: shmobile: Enable shmobile Runtime PM from MSTP clock driver

[Simon Horman]

On Mon, Apr 28, 2014 at 07:45:38AM +0200, Geert Uytterhoeven wrote:
> Hi Simon,
> 
> On Mon, Apr 28, 2014 at 2:10 AM, Simon Horman <horms@verge.net.au> wrote:
> >> --- a/drivers/sh/pm_runtime.c
> >> +++ b/drivers/sh/pm_runtime.c
> >> @@ -75,20 +75,24 @@ static struct pm_clk_notifier_block platform_bus_notifier = {
> >>       .con_ids = { NULL, },
> >>  };
> >>
> >> -static bool default_pm_on;
> >> +#if defined(CONFIG_SUPERH) || defined(CONFIG_ARCH_SHMOBILE_LEGACY)
> >> +bool default_pm_on = true;
> >> +#else
> >> +bool default_pm_on;
> >> +#endif
> >
> > I wonder if there is some way we can get the compiler
> > to optimise out code in the case of default_pm_on = false,
> > perhaps by using IS_ENABLED() in conjunction with a Kconfig variable.
> 
> What's the use case of that?
> 
> This code is compiled only if SUPERH || ARCH_SHMOBILE_LEGACY ||
> ARCH_SHMOBILE_MULTIPLATORM.
> If should always be used when running on shmobile.

Sorry, I missed that point.
Please ignore my previous comment.