[PATCH v2 18/18] cpufreq: scmi: add support for fast frequency switching
From: Sudeep Holla <hidden>
Date: 2017-08-04 14:32:53
Also in:
linux-devicetree, linux-pm, lkml
Subsystem:
cpu frequency scaling framework, system control & power/management interface (scpi/scmi) message protocol drivers, the rest · Maintainers:
"Rafael J. Wysocki", Viresh Kumar, Sudeep Holla, Linus Torvalds
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: "Rafael J. Wysocki" <redacted> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: linux-pm at vger.kernel.org Signed-off-by: Sudeep Holla <redacted> --- drivers/cpufreq/scmi-cpufreq.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/drivers/cpufreq/scmi-cpufreq.c b/drivers/cpufreq/scmi-cpufreq.c
index 034359cafea5..cb1084cb1ef1 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c@@ -61,6 +61,19 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) return perf_ops->freq_set(priv->handle, priv->domain_id, freq, false); } +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 = priv->handle->perf_ops; + + if (!perf_ops->freq_set(priv->handle, priv->domain_id, + target_freq * 1000, true)) + return target_freq; + + return CPUFREQ_ENTRY_INVALID; +} + static int scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) {
@@ -164,6 +177,7 @@ 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:
@@ -180,6 +194,7 @@ static int scmi_cpufreq_exit(struct cpufreq_policy *policy) { struct scmi_data *priv = policy->driver_data; + policy->fast_switch_possible = false; cpufreq_cooling_unregister(priv->cdev); dev_pm_opp_free_cpufreq_table(priv->cpu_dev, &policy->freq_table); dev_pm_opp_cpumask_remove_table(policy->related_cpus);
@@ -228,6 +243,7 @@ static struct cpufreq_driver scmi_cpufreq_driver = { .init = scmi_cpufreq_init, .exit = scmi_cpufreq_exit, .ready = scmi_cpufreq_ready, + .fast_switch = scmi_cpufreq_fast_switch, }; static int scmi_cpufreq_probe(struct platform_device *pdev)
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2.7.4