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" <r...@sisk.pl> >> Cc: Viresh Kumar <viresh.ku...@linaro.org> >> Cc: Grant Likely <grant.lik...@linaro.org> >> Cc: Rob Herring <rob.herr...@calxeda.com> >> Cc: cpuf...@vger.kernel.org >> Cc: linux...@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Cc: devicetree-disc...@lists.ozlabs.org >> Signed-off-by: Eduardo Valentin <eduardo.valen...@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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