[RFC PATCH 01/14] cpufreq: cpufreq-cpu0: add dt node parsing for 'cooling-zones'

[RFC PATCH 01/14] cpufreq: cpufreq-cpu0: add dt node parsing for 'cooling-zones'

[Eduardo Valentin]

This patch changes the cpufreq-cpu0 driver to consider if
a cpu needs cooling (with cpufreq). In case the cooling is needed,
it can be flagged at the cpu0 device tree node, with the list
of zones property 'cooling-zones'.

In case this list of zones is present, the driver will
load a cpufreq cooling device in the system. The cpufreq-cpu0
driver is not interested in determining how the system should
be using the cooling device. The driver is responsible
only of loading the cooling device.

Describing how the cooling device will be used can be
accomplished by setting up a thermal zone that references
and is composed by the cpufreq cooling device.

Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
---
 Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt |  4 ++++
 drivers/cpufreq/cpufreq-cpu0.c                             | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
index 051f764..add50f7 100644
--- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
+++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
@@ -15,6 +15,9 @@ Optional properties:
 - clock-latency: Specify the possible maximum transition latency for clock,
   in unit of nanoseconds.
 - voltage-tolerance: Specify the CPU voltage tolerance in percentage.
+- cooling-zones: A list of thermal zones phandles. The generic cpu
+  cooling (freq clipping) is loaded by the generic cpufreq-cpu0 driver
+  in case the device tree node has this list.
 
 Examples:
 
@@ -33,6 +36,7 @@ cpus {
 			198000  850000
 		>;
 		clock-latency = <61036>; /* two CLK32 periods */
+		cooling-zones = <&cpu_thermal>;
 	};
 
 	cpu@1 {
diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
index ad1fde2..ede6487 100644
--- a/drivers/cpufreq/cpufreq-cpu0.c
+++ b/drivers/cpufreq/cpufreq-cpu0.c
@@ -20,6 +20,9 @@
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
 #include <linux/slab.h>
+#include <linux/thermal.h>
+#include <linux/cpu_cooling.h>
+#include <linux/cpumask.h>
 
 static unsigned int transition_latency;
 static unsigned int voltage_tolerance; /* in percentage */
@@ -28,6 +31,7 @@ static struct device *cpu_dev;
 static struct clk *cpu_clk;
 static struct regulator *cpu_reg;
 static struct cpufreq_frequency_table *freq_table;
+static struct thermal_cooling_device *cdev;
 
 static int cpu0_verify_speed(struct cpufreq_policy *policy)
 {
@@ -268,6 +272,13 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
 		goto out_free_table;
 	}
 
+	/*
+	 * For now, just loading the cooling device;
+	 * thermal DT code takes care of matching them.
+	 */
+	if (of_find_property(np, "cooling-zones", NULL))
+		cdev = cpufreq_cooling_register(cpu_present_mask);
+
 	of_node_put(np);
 	of_node_put(parent);
 	return 0;
@@ -283,6 +294,7 @@ out_put_parent:
 
 static int cpu0_cpufreq_remove(struct platform_device *pdev)
 {
+	cpufreq_cooling_unregister(cdev);
 	cpufreq_unregister_driver(&cpu0_cpufreq_driver);
 	opp_free_cpufreq_table(cpu_dev, &freq_table);
 
-- 
1.8.2.1.342.gfa7285d

Re: [RFC PATCH 01/14] cpufreq: cpufreq-cpu0: add dt node parsing for 'cooling-zones'

[Viresh Kumar]

On 24 August 2013 04:45, Eduardo Valentin <eduardo.valentin@ti.com> wrote:
> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
> index ad1fde2..ede6487 100644
> --- a/drivers/cpufreq/cpufreq-cpu0.c
> +++ b/drivers/cpufreq/cpufreq-cpu0.c
> @@ -20,6 +20,9 @@
>  #include <linux/platform_device.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
> +#include <linux/thermal.h>
> +#include <linux/cpu_cooling.h>
> +#include <linux/cpumask.h>

In alphabetical order please..

> @@ -268,6 +272,13 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
>                 goto out_free_table;
>         }
>
> +       /*
> +        * For now, just loading the cooling device;
> +        * thermal DT code takes care of matching them.
> +        */
> +       if (of_find_property(np, "cooling-zones", NULL))
> +               cdev = cpufreq_cooling_register(cpu_present_mask);

Should we check if it passed or failed? And if failed Atleast flag an
appropriate message?

Re: [RFC PATCH 01/14] cpufreq: cpufreq-cpu0: add dt node parsing for 'cooling-zones'

[Eduardo Valentin]

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On 26-08-2013 00:42, Viresh Kumar wrote:
> On 24 August 2013 04:45, Eduardo Valentin <eduardo.valentin@ti.com> wrote:
>> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
>> index ad1fde2..ede6487 100644
>> --- a/drivers/cpufreq/cpufreq-cpu0.c
>> +++ b/drivers/cpufreq/cpufreq-cpu0.c
>> @@ -20,6 +20,9 @@
>>  #include <linux/platform_device.h>
>>  #include <linux/regulator/consumer.h>
>>  #include <linux/slab.h>
>> +#include <linux/thermal.h>
>> +#include <linux/cpu_cooling.h>
>> +#include <linux/cpumask.h>
> 
> In alphabetical order please..
> 

OK.

>> @@ -268,6 +272,13 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
>>                 goto out_free_table;
>>         }
>>
>> +       /*
>> +        * For now, just loading the cooling device;
>> +        * thermal DT code takes care of matching them.
>> +        */
>> +       if (of_find_property(np, "cooling-zones", NULL))
>> +               cdev = cpufreq_cooling_register(cpu_present_mask);
> 
> Should we check if it passed or failed? And if failed Atleast flag an
> appropriate message?
> 

Yes, we need error checking code. I will add in next version. Thanks Kumar.

> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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Re: [RFC PATCH 01/14] cpufreq: cpufreq-cpu0: add dt node parsing for 'cooling-zones'

[Mark Rutland]

On Sat, Aug 24, 2013 at 12:15:42AM +0100, Eduardo Valentin wrote:
> This patch changes the cpufreq-cpu0 driver to consider if
> a cpu needs cooling (with cpufreq). In case the cooling is needed,
> it can be flagged at the cpu0 device tree node, with the list
> of zones property 'cooling-zones'.
> 
> In case this list of zones is present, the driver will
> load a cpufreq cooling device in the system. The cpufreq-cpu0
> driver is not interested in determining how the system should
> be using the cooling device. The driver is responsible
> only of loading the cooling device.
> 
> Describing how the cooling device will be used can be
> accomplished by setting up a thermal zone that references
> and is composed by the cpufreq cooling device.
> 
> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
> Cc: Viresh Kumar <viresh.kumar@linaro.org>
> Cc: Grant Likely <grant.likely@linaro.org>
> Cc: Rob Herring <rob.herring@calxeda.com>
> Cc: cpufreq@vger.kernel.org
> Cc: linux-pm@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: devicetree-discuss@lists.ozlabs.org
> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
> ---
>  Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt |  4 ++++
>  drivers/cpufreq/cpufreq-cpu0.c                             | 12 ++++++++++++
>  2 files changed, 16 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> index 051f764..add50f7 100644
> --- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> @@ -15,6 +15,9 @@ Optional properties:
>  - clock-latency: Specify the possible maximum transition latency for clock,
>    in unit of nanoseconds.
>  - voltage-tolerance: Specify the CPU voltage tolerance in percentage.
> +- cooling-zones: A list of thermal zones phandles. The generic cpu
> +  cooling (freq clipping) is loaded by the generic cpufreq-cpu0 driver
> +  in case the device tree node has this list.

Bindings should not describe the behaviour of any kernel (and for that
reason I'm not very keen on the current cpufreq-cpu0 binding document).

Bindings should simply describe the hardware. This addition could
instead be:

 - cooling-zones: a list of thermal zone phandles.

However, as the thermal zone binding doesn't seem to have appeared by
this patch, it should get moved later anyway...

Thanks,
Mark.

>  
>  Examples:
>  
> @@ -33,6 +36,7 @@ cpus {
>  			198000  850000
>  		>;
>  		clock-latency = <61036>; /* two CLK32 periods */
> +		cooling-zones = <&cpu_thermal>;
>  	};
>  
>  	cpu@1 {
> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
> index ad1fde2..ede6487 100644
> --- a/drivers/cpufreq/cpufreq-cpu0.c
> +++ b/drivers/cpufreq/cpufreq-cpu0.c
> @@ -20,6 +20,9 @@
>  #include <linux/platform_device.h>
>  #include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
> +#include <linux/thermal.h>
> +#include <linux/cpu_cooling.h>
> +#include <linux/cpumask.h>
>  
>  static unsigned int transition_latency;
>  static unsigned int voltage_tolerance; /* in percentage */
> @@ -28,6 +31,7 @@ static struct device *cpu_dev;
>  static struct clk *cpu_clk;
>  static struct regulator *cpu_reg;
>  static struct cpufreq_frequency_table *freq_table;
> +static struct thermal_cooling_device *cdev;
>  
>  static int cpu0_verify_speed(struct cpufreq_policy *policy)
>  {
> @@ -268,6 +272,13 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
>  		goto out_free_table;
>  	}
>  
> +	/*
> +	 * For now, just loading the cooling device;
> +	 * thermal DT code takes care of matching them.
> +	 */
> +	if (of_find_property(np, "cooling-zones", NULL))
> +		cdev = cpufreq_cooling_register(cpu_present_mask);
> +
>  	of_node_put(np);
>  	of_node_put(parent);
>  	return 0;
> @@ -283,6 +294,7 @@ out_put_parent:
>  
>  static int cpu0_cpufreq_remove(struct platform_device *pdev)
>  {
> +	cpufreq_cooling_unregister(cdev);
>  	cpufreq_unregister_driver(&cpu0_cpufreq_driver);
>  	opp_free_cpufreq_table(cpu_dev, &freq_table);
>  
> -- 
> 1.8.2.1.342.gfa7285d
> 
> 

Re: [RFC PATCH 01/14] cpufreq: cpufreq-cpu0: add dt node parsing for 'cooling-zones'

[Eduardo Valentin]

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Hey Mark,

On 27-08-2013 05:29, Mark Rutland wrote:
> On Sat, Aug 24, 2013 at 12:15:42AM +0100, Eduardo Valentin wrote:
>> This patch changes the cpufreq-cpu0 driver to consider if
>> a cpu needs cooling (with cpufreq). In case the cooling is needed,
>> it can be flagged at the cpu0 device tree node, with the list
>> of zones property 'cooling-zones'.
>>
>> In case this list of zones is present, the driver will
>> load a cpufreq cooling device in the system. The cpufreq-cpu0
>> driver is not interested in determining how the system should
>> be using the cooling device. The driver is responsible
>> only of loading the cooling device.
>>
>> Describing how the cooling device will be used can be
>> accomplished by setting up a thermal zone that references
>> and is composed by the cpufreq cooling device.
>>
>> Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
>> Cc: Viresh Kumar <viresh.kumar@linaro.org>
>> Cc: Grant Likely <grant.likely@linaro.org>
>> Cc: Rob Herring <rob.herring@calxeda.com>
>> Cc: cpufreq@vger.kernel.org
>> Cc: linux-pm@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: devicetree-discuss@lists.ozlabs.org
>> Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
>> ---
>>  Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt |  4 ++++
>>  drivers/cpufreq/cpufreq-cpu0.c                             | 12 ++++++++++++
>>  2 files changed, 16 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
>> index 051f764..add50f7 100644
>> --- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
>> +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
>> @@ -15,6 +15,9 @@ Optional properties:
>>  - clock-latency: Specify the possible maximum transition latency for clock,
>>    in unit of nanoseconds.
>>  - voltage-tolerance: Specify the CPU voltage tolerance in percentage.
>> +- cooling-zones: A list of thermal zones phandles. The generic cpu
>> +  cooling (freq clipping) is loaded by the generic cpufreq-cpu0 driver
>> +  in case the device tree node has this list.
> 
> Bindings should not describe the behaviour of any kernel (and for that
> reason I'm not very keen on the current cpufreq-cpu0 binding document).
> 

Right.

> Bindings should simply describe the hardware. This addition could
> instead be:
> 
>  - cooling-zones: a list of thermal zone phandles.
> 

OK. This works for me.

> However, as the thermal zone binding doesn't seem to have appeared by
> this patch, it should get moved later anyway...

Yeah, I will reorder them.

> 
> Thanks,
> Mark.
> 
>>  
>>  Examples:
>>  
>> @@ -33,6 +36,7 @@ cpus {
>>  			198000  850000
>>  		>;
>>  		clock-latency = <61036>; /* two CLK32 periods */
>> +		cooling-zones = <&cpu_thermal>;
>>  	};
>>  
>>  	cpu@1 {
>> diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
>> index ad1fde2..ede6487 100644
>> --- a/drivers/cpufreq/cpufreq-cpu0.c
>> +++ b/drivers/cpufreq/cpufreq-cpu0.c
>> @@ -20,6 +20,9 @@
>>  #include <linux/platform_device.h>
>>  #include <linux/regulator/consumer.h>
>>  #include <linux/slab.h>
>> +#include <linux/thermal.h>
>> +#include <linux/cpu_cooling.h>
>> +#include <linux/cpumask.h>
>>  
>>  static unsigned int transition_latency;
>>  static unsigned int voltage_tolerance; /* in percentage */
>> @@ -28,6 +31,7 @@ static struct device *cpu_dev;
>>  static struct clk *cpu_clk;
>>  static struct regulator *cpu_reg;
>>  static struct cpufreq_frequency_table *freq_table;
>> +static struct thermal_cooling_device *cdev;
>>  
>>  static int cpu0_verify_speed(struct cpufreq_policy *policy)
>>  {
>> @@ -268,6 +272,13 @@ static int cpu0_cpufreq_probe(struct platform_device *pdev)
>>  		goto out_free_table;
>>  	}
>>  
>> +	/*
>> +	 * For now, just loading the cooling device;
>> +	 * thermal DT code takes care of matching them.
>> +	 */
>> +	if (of_find_property(np, "cooling-zones", NULL))
>> +		cdev = cpufreq_cooling_register(cpu_present_mask);
>> +
>>  	of_node_put(np);
>>  	of_node_put(parent);
>>  	return 0;
>> @@ -283,6 +294,7 @@ out_put_parent:
>>  
>>  static int cpu0_cpufreq_remove(struct platform_device *pdev)
>>  {
>> +	cpufreq_cooling_unregister(cdev);
>>  	cpufreq_unregister_driver(&cpu0_cpufreq_driver);
>>  	opp_free_cpufreq_table(cpu_dev, &freq_table);
>>  
>> -- 
>> 1.8.2.1.342.gfa7285d
>>
>>
> 
> 


-- 
You have got to be excited about what you are doing. (L. Lamport)

Eduardo Valentin


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