From 02f208c5c60549039445402505dea284e15f0f4f Mon Sep 17 00:00:00 2001 From: Sudeep Holla Date: Thu, 20 Jul 2017 14:43:07 +0100 Subject: 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 Acked-by: Viresh Kumar Signed-off-by: Sudeep Holla --- drivers/cpufreq/scmi-cpufreq.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'drivers/cpufreq/scmi-cpufreq.c') 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, -- cgit v1.2.3