[PATCH v4 20/20] cpufreq: scmi: add support for fast frequency switching
From: Sudeep Holla <hidden>
Date: 2017-11-03 14:49:51
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 b1057a13e6a7..91df5013f7b2 100644
--- a/drivers/cpufreq/scmi-cpufreq.c
+++ b/drivers/cpufreq/scmi-cpufreq.c@@ -64,6 +64,19 @@ scmi_cpufreq_set_target(struct cpufreq_policy *policy, unsigned int index) return perf_ops->freq_set(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 = handle->perf_ops; + + if (!perf_ops->freq_set(handle, priv->domain_id, + target_freq * 1000, true)) + return target_freq; + + return 0; +} + static int scmi_get_sharing_cpus(struct device *cpu_dev, struct cpumask *cpumask) {
@@ -167,6 +180,7 @@ 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:
@@ -183,6 +197,7 @@ 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); kfree(priv);
@@ -226,6 +241,7 @@ 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