[PATCH 2/7] cpufreq: dt: Register an Energy Model

[Quentin Perret <quentin.perret@arm.com>]

Now that PM_OPP provides a helper function to estimate the power
consumed by CPUs, make sure to try and register an Energy Model (EM)
from cpufreq-dt, hence ensuring interested subsystems (the task
scheduler, for example) can make use of that information when available.

Signed-off-by: Quentin Perret <quentin.perret@arm.com>
---
 drivers/cpufreq/cpufreq-dt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/cpufreq-dt.c b/drivers/cpufreq/cpufreq-dt.c
index e58bfcb1169e..7556e07e7a9f 100644
--- a/drivers/cpufreq/cpufreq-dt.c
+++ b/drivers/cpufreq/cpufreq-dt.c
@@ -16,6 +16,7 @@
 #include <linux/cpu_cooling.h>
 #include <linux/cpufreq.h>
 #include <linux/cpumask.h>
+#include <linux/energy_model.h>
 #include <linux/err.h>
 #include <linux/module.h>
 #include <linux/of.h>
@@ -152,6 +153,7 @@ static int resources_available(void)
 
 static int cpufreq_init(struct cpufreq_policy *policy)
 {
+	struct em_data_callback em_cb = EM_DATA_CB(of_dev_pm_opp_get_cpu_power);
 	struct cpufreq_frequency_table *freq_table;
 	struct opp_table *opp_table = NULL;
 	struct private_data *priv;
@@ -160,7 +162,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	unsigned int transition_latency;
 	bool fallback = false;
 	const char *name;
-	int ret;
+	int ret, nr_opp;
 
 	cpu_dev = get_cpu_device(policy->cpu);
 	if (!cpu_dev) {
@@ -237,6 +239,7 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 		ret = -EPROBE_DEFER;
 		goto out_free_opp;
 	}
+	nr_opp = ret;
 
 	if (fallback) {
 		cpumask_setall(policy->cpus);
@@ -280,6 +283,8 @@ static int cpufreq_init(struct cpufreq_policy *policy)
 	policy->cpuinfo.transition_latency = transition_latency;
 	policy->dvfs_possible_from_any_cpu = true;
 
+	em_register_perf_domain(policy->cpus, nr_opp, &em_cb);
+
 	return 0;
 
 out_free_cpufreq_table:
-- 
2.20.1