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

Zhang, Rui
2014-01-12T14:31:06Z

> -----Original Message-----
> From: Eduardo Valentin [mailto:eduardo.valentin@ti.com]
> Sent: Wednesday, November 13, 2013 3:46 AM
> To: swarren@wwwdotorg.org; pawel.moll@arm.com; mark.rutland@arm.com;
> ian.campbell@citrix.com; rob.herring@calxeda.com; linux@roeck-us.net;
> Zhang, Rui
> Cc: wni@nvidia.com; grant.likely@linaro.org; R, Durgadoss; linux-
> pm@vger.kernel.org; devicetree@vger.kernel.org; lm-sensors@lm-
> sensors.org; linux-kernel@vger.kernel.org; Eduardo Valentin; Rafael J.
> Wysocki; Viresh Kumar; cpufreq@vger.kernel.org; devicetree-
> discuss@lists.ozlabs.org
> Subject: [PATCHv5 05/20] cpufreq: cpufreq-cpu0: add dt node parsing for
> cooling device properties
> Importance: High
>
> 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>
> 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

config: make ARCH=arm multi_v7_defconfig
All warnings:
warning: (ARM_HIGHBANK_CPUFREQ) selects GENERIC_CPUFREQ_CPU0 which
has unmet direct dependencies (ARCH_HAS_CPUFREQ && CPU_FREQ &&
HAVE_CLK && REGULATOR && PM_OPP && OF && THERMAL && CPU_THERMAL)

I think you need to select THERMAL and CPU_THERMAL instead, right?

Thanks,
rui
> 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);
>
> --
> 1.8.2.1.342.gfa7285d