[PATCH v6 20/20] cpufreq: scmi: add support for fast frequency switching
From: Sudeep Holla <hidden>
Date: 2018-02-23 16:23:50
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: linux-pm at vger.kernel.org Acked-by: Rafael J. Wysocki <redacted> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Sudeep Holla <redacted> --- 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