The cpufreq core provides option for drivers to implement fast_switch
callback which is invoked for frequency switching from interrupt context.
This patch adds support for fast_switch callback in SCMI cpufreq driver
by making use of polling based SCMI transfer. It also sets the flag
fast_switch_possible.
Cc: linux-pm@xxxxxxxxxxxxxxx
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Acked-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
---
drivers/cpufreq/scmi-cpufreq.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
index 3745dc5fe2a8..ec0c58ddc1ed 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c
@@ -69,6 +69,22 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index)
return ret;
}
+static unsigned int scmi_cpufreq_fast_switch(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct scmi_data *priv = policy->driver_data;
+ struct scmi_perf_ops *perf_ops = handle->perf_ops;
+
+ if (!perf_ops->freq_set(handle, priv->domain_id,
+ target_freq * 1000, true)) {
+ arch_set_freq_scale(policy->related_cpus, target_freq,
+ policy->cpuinfo.max_freq);
+ return target_freq;
+ }
+
+ return 0;
+}
+
static int
scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask)
{
@@ -168,6 +184,7 @@ static int scmi_cpufreq_init(struct cpufreq_policy *policy)
policy->cpuinfo.transition_latency = latency;
+ policy->fast_switch_possible = true;
return 0;
out_free_cpufreq_table:
@@ -206,6 +223,7 @@ static struct cpufreq_driver scmi_cpufreq_driver = {
.verify = cpufreq_generic_frequency_table_verify,
.attr = cpufreq_generic_attr,
.target_index = scmi_cpufreq_set_target,
+ .fast_switch = scmi_cpufreq_fast_switch,
.get = scmi_cpufreq_get_rate,
.init = scmi_cpufreq_init,
.exit = scmi_cpufreq_exit,
--
2.7.4
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