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>
This commit is contained in:
Sudeep Holla 2017-07-20 14:43:07 +01:00
parent 99d6bdf338
commit 02f208c5c6

View file

@ -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,