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authorSudeep Holla <sudeep.holla@arm.com>2017-07-20 14:43:07 +0100
committerSudeep Holla <sudeep.holla@arm.com>2018-02-28 16:37:57 +0000
commit02f208c5c60549039445402505dea284e15f0f4f (patch)
tree061d9650a8f18685396501b230ec67af03ee0dbc
parent99d6bdf3387734d75e3e34e94a58b8a355b7a9c8 (diff)
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cpufreq: scmi: add support for fast frequency switching
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@vger.kernel.org Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
-rw-r--r--drivers/cpufreq/scmi-cpufreq.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
index b04f07f1b1d2..959a1dbe3835 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c
@@ -61,6 +61,22 @@ 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)
{
@@ -160,6 +176,7 @@ 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:
@@ -198,6 +215,7 @@ 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,