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authorPunit Agrawal <punit.agrawal@arm.com>2015-11-17 12:06:23 +0000
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-12-10 00:14:58 +0100
commit2f7e8a175db72bdaf377235962fd85796edb3fbc (patch)
tree4f25585f65cece59ca04bbe72981db5c1a6d1089 /drivers/cpufreq
parentf8fa8ae06b8c2c25d81c99766f9226adc5c3e073 (diff)
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>
Diffstat (limited to 'drivers/cpufreq')
-rw-r--r--drivers/cpufreq/Kconfig.arm2
-rw-r--r--drivers/cpufreq/arm_big_little.c41
2 files changed, 43 insertions, 0 deletions
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 235a1ba73d92..80fbfb32b5a9 100644
--- 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 c5d256caa664..c251247ae661 100644
--- 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,
};