Re: [PATCHv5 05/20] cpufreq: cpufreq-cpu0: add dt node parsing for cooling device properties

Rafael J. Wysocki
2013-11-14T22:04:44Z

On Thursday, November 14, 2013 09:17:21 AM Eduardo Valentin wrote:
> On 12-11-2013 15:46, 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,
> > the cpu0 device tree node needs to be properly configured
> > with cooling device properties.
> >
> > In case these properties are 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>
>
> Rafael, Can I still assume you are OK with this patch and add your
> acked-by [1]?
> http://www.spinics.net/lists/lm-sensors/msg39136.html
>
> It has changed a few bits from V1 to here. The idea is still same though.

Well, this is fine by me, personally, but I'd like someone from the ARM camp to
ACK this to be honest.

Thanks!

> > 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>
> > ---
> > .../devicetree/bindings/cpufreq/cpufreq-cpu0.txt | 7 +++++++
> > drivers/cpufreq/Kconfig | 2 +-
> > drivers/cpufreq/cpufreq-cpu0.c | 16 ++++++++++++++++
> > 3 files changed, 24 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> > index 051f764..f055515 100644
> > --- a/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> > +++ b/Documentation/devicetree/bindings/cpufreq/cpufreq-cpu0.txt
> > @@ -15,6 +15,10 @@ 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-cells:
> > +- cooling-min-level:
> > +- cooling-max-level:
> > + Please refer to Documentation/devicetree/bindings/thermal/thermal.txt.
> >
> > Examples:
> >
> > @@ -33,6 +37,9 @@ cpus {
> > 198000 850000
> > >;
> > clock-latency = <61036>; /* two CLK32 periods */
> > + #cooling-cells = <2>;
> > + cooling-min-level = <0>;
> > + cooling-max-level = <2>;
> > };
> >
> > cpu@1 {
> > diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
> > index 534fcb8..fc1e9a5 100644
> > --- a/drivers/cpufreq/Kconfig
> > +++ b/drivers/cpufreq/Kconfig
> > @@ -186,7 +186,7 @@ config CPU_FREQ_GOV_CONSERVATIVE
> >
> > config GENERIC_CPUFREQ_CPU0
> > tristate "Generic CPU0 cpufreq driver"
> > - depends on HAVE_CLK && REGULATOR && PM_OPP && OF
> > + depends on HAVE_CLK && REGULATOR && PM_OPP && OF && THERMAL && CPU_THERMAL
> > select CPU_FREQ_TABLE
> > help
> > This adds a generic cpufreq driver for CPU0 frequency management.
> > diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c
> > index c522a95..568aaf3 100644
> > --- a/drivers/cpufreq/cpufreq-cpu0.c
> > +++ b/drivers/cpufreq/cpufreq-cpu0.c
> > @@ -13,7 +13,9 @@
> >
> > #include <linux/clk.h>
> > #include <linux/cpu.h>
> > +#include <linux/cpu_cooling.h>
> > #include <linux/cpufreq.h>
> > +#include <linux/cpumask.h>
> > #include <linux/err.h>
> > #include <linux/module.h>
> > #include <linux/of.h>
> > @@ -21,6 +23,7 @@
> > #include <linux/platform_device.h>
> > #include <linux/regulator/consumer.h>
> > #include <linux/slab.h>
> > +#include <linux/thermal.h>
> >
> > static unsigned int transition_latency;
> > static unsigned int voltage_tolerance; /* in percentage */
> > @@ -29,6 +32,7 @@ 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)
> > {
> > @@ -260,6 +264,17 @@ 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-cells", NULL)) {
> > + cdev = of_cpufreq_cooling_register(np, cpu_present_mask);
> > + if (IS_ERR(cdev))
> > + pr_err("running cpufreq without cooling device: %ld\n",
> > + PTR_ERR(cdev));
> > + }
> > +
> > of_node_put(np);
> > return 0;
> >
> > @@ -272,6 +287,7 @@ out_put_node:
> >
> > 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);
> >
> >
>
>
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.