From 77cff5926a14e80d4545be5841d5938b87b654a4 Mon Sep 17 00:00:00 2001 From: Eduardo Valentin Date: Mon, 15 Jul 2013 09:09:14 -0400 Subject: [PATCH] cpufreq: cpufreq-cpu0: add dt node parsing for cooling device properties 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" Cc: Grant Likely Cc: Rob Herring Cc: cpufreq@vger.kernel.org Cc: linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: devicetree-discuss@lists.ozlabs.org Acked-by: Viresh Kumar Signed-off-by: Eduardo Valentin --- .../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 051f764bedb8..f055515d2b62 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 38093e272377..6b8cde5f98af 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -181,7 +181,7 @@ 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 help This adds a generic cpufreq driver for CPU0 frequency management. It supports both uniprocessor (UP) and symmetric multiprocessor (SMP) diff --git a/drivers/cpufreq/cpufreq-cpu0.c b/drivers/cpufreq/cpufreq-cpu0.c index d4585ce2346c..91c7bb67bc74 100644 --- a/drivers/cpufreq/cpufreq-cpu0.c +++ b/drivers/cpufreq/cpufreq-cpu0.c @@ -13,7 +13,9 @@ #include #include +#include #include +#include #include #include #include @@ -21,6 +23,7 @@ #include #include #include +#include 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 unsigned int cpu0_get_speed(unsigned int cpu) { @@ -201,6 +205,17 @@ 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; @@ -213,6 +228,7 @@ out_put_node: static int cpu0_cpufreq_remove(struct platform_device *pdev) { + cpufreq_cooling_unregister(cdev); cpufreq_unregister_driver(&cpu0_cpufreq_driver); dev_pm_opp_free_cpufreq_table(cpu_dev, &freq_table); -- 2.39.5