cpufreq: arm_big_little: Add support to register a cpufreq cooling device

Register passive cooling devices when initialising cpufreq on
big.LITTLE systems. If the device tree provides a dynamic power
coefficient for the CPUs then the bound cooling device will support
the extensions that allow it to be used with all the existing thermal
governors including the power allocator governor.

A cooling device will be created per individual frequency domain and
can be bound to thermal zones via the thermal DT bindings.

Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 235a1ba73d92d577bbf605f5dab9d737fe246797..80fbfb32b5a9913a481b079e51574ac0c037a4de 100644 (file)
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -6,6 +6,8 @@
 config ARM_BIG_LITTLE_CPUFREQ
        tristate "Generic ARM big LITTLE CPUfreq driver"
        depends on (ARM_CPU_TOPOLOGY || ARM64) && HAVE_CLK
+       # if CPU_THERMAL is on and THERMAL=m, ARM_BIT_LITTLE_CPUFREQ cannot be =y
+       depends on !CPU_THERMAL || THERMAL
        select PM_OPP
        help
          This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.

diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c
index c5d256caa664a63731e0cb7db6f5b00e31c750d8..c251247ae6613e860164627d8c8161f2b0d0cfe5 100644 (file)
--- a/drivers/cpufreq/arm_big_little.c
+++ b/drivers/cpufreq/arm_big_little.c
@@ -23,6 +23,7 @@
 #include <linux/cpu.h>
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
+#include <linux/cpu_cooling.h>
 #include <linux/export.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -55,6 +56,7 @@ static bool bL_switching_enabled;
 #define ACTUAL_FREQ(cluster, freq)  ((cluster == A7_CLUSTER) ? freq << 1 : freq)
 #define VIRT_FREQ(cluster, freq)    ((cluster == A7_CLUSTER) ? freq >> 1 : freq)
 
+static struct thermal_cooling_device *cdev[MAX_CLUSTERS];
 static struct cpufreq_arm_bL_ops *arm_bL_ops;
 static struct clk *clk[MAX_CLUSTERS];
 static struct cpufreq_frequency_table *freq_table[MAX_CLUSTERS + 1];
@@ -493,6 +495,12 @@ static int bL_cpufreq_init(struct cpufreq_policy *policy)
 static int bL_cpufreq_exit(struct cpufreq_policy *policy)
 {
        struct device *cpu_dev;
+       int cur_cluster = cpu_to_cluster(policy->cpu);
+
+       if (cur_cluster < MAX_CLUSTERS) {
+               cpufreq_cooling_unregister(cdev[cur_cluster]);
+               cdev[cur_cluster] = NULL;
+       }
 
        cpu_dev = get_cpu_device(policy->cpu);
        if (!cpu_dev) {
@@ -507,6 +515,38 @@ static int bL_cpufreq_exit(struct cpufreq_policy *policy)
        return 0;
 }
 
+static void bL_cpufreq_ready(struct cpufreq_policy *policy)
+{
+       struct device *cpu_dev = get_cpu_device(policy->cpu);
+       int cur_cluster = cpu_to_cluster(policy->cpu);
+       struct device_node *np;
+
+       /* Do not register a cpu_cooling device if we are in IKS mode */
+       if (cur_cluster >= MAX_CLUSTERS)
+               return;
+
+       np = of_node_get(cpu_dev->of_node);
+       if (WARN_ON(!np))
+               return;
+
+       if (of_find_property(np, "#cooling-cells", NULL)) {
+               u32 power_coefficient = 0;
+
+               of_property_read_u32(np, "dynamic-power-coefficient",
+                                    &power_coefficient);
+
+               cdev[cur_cluster] = of_cpufreq_power_cooling_register(np,
+                               policy->related_cpus, power_coefficient, NULL);
+               if (IS_ERR(cdev[cur_cluster])) {
+                       dev_err(cpu_dev,
+                               "running cpufreq without cooling device: %ld\n",
+                               PTR_ERR(cdev[cur_cluster]));
+                       cdev[cur_cluster] = NULL;
+               }
+       }
+       of_node_put(np);
+}
+
 static struct cpufreq_driver bL_cpufreq_driver = {
        .name                   = "arm-big-little",
        .flags                  = CPUFREQ_STICKY |
@@ -517,6 +557,7 @@ static struct cpufreq_driver bL_cpufreq_driver = {
        .get                    = bL_cpufreq_get_rate,
        .init                   = bL_cpufreq_init,
        .exit                   = bL_cpufreq_exit,
+       .ready                  = bL_cpufreq_ready,
        .attr                   = cpufreq_generic_attr,
 };