From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Muckle Subject: [PATCH v2 1/3] cpufreq: add resolve_freq driver callback Date: Wed, 25 May 2016 19:52:59 -0700 Message-ID: <1464231181-30741-2-git-send-email-smuckle@linaro.org> References: <1464231181-30741-1-git-send-email-smuckle@linaro.org> Return-path: In-Reply-To: <1464231181-30741-1-git-send-email-smuckle@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: Peter Zijlstra , Ingo Molnar , "Rafael J. Wysocki" , Viresh Kumar Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Vincent Guittot , Morten Rasmussen , Dietmar Eggemann , Juri Lelli , Patrick Bellasi , Michael Turquette List-Id: linux-pm@vger.kernel.org Cpufreq governors may need to know what a particular target frequency maps to in the driver without necessarily wanting to set the frequency. Support this operation via a new cpufreq API, cpufreq_driver_resolve_freq(). The above API will call a new cpufreq driver callback, resolve_freq(), if it has been registered by the driver. If that callback has not been registered and a frequency table is available then the frequency table is walked using cpufreq_frequency_table_target(). UINT_MAX is returned if no driver callback or frequency table is available. Suggested-by: Rafael J. Wysocki Signed-off-by: Steve Muckle --- drivers/cpufreq/cpufreq.c | 25 +++++++++++++++++++++++++ include/linux/cpufreq.h | 11 +++++++++++ 2 files changed, 36 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 77d77a4e3b74..3b44f4bdc071 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1849,6 +1849,31 @@ unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, } EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); +unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, + unsigned int target_freq) +{ + struct cpufreq_frequency_table *freq_table; + int index, retval; + + clamp_val(target_freq, policy->min, policy->max); + + if (cpufreq_driver->resolve_freq) + return cpufreq_driver->resolve_freq(policy, target_freq); + + freq_table = cpufreq_frequency_get_table(policy->cpu); + if (!freq_table) + return UINT_MAX; + + retval = cpufreq_frequency_table_target(policy, freq_table, + target_freq, CPUFREQ_RELATION_L, + &index); + if (retval) + return UINT_MAX; + + return freq_table[index].frequency; +} +EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); + /* Must set freqs->new to intermediate frequency */ static int __target_intermediate(struct cpufreq_policy *policy, struct cpufreq_freqs *freqs, int index) diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 4e81e08db752..675f17f98e75 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -271,6 +271,13 @@ struct cpufreq_driver { int (*target_intermediate)(struct cpufreq_policy *policy, unsigned int index); + /* + * Return the driver-supported frequency that a particular target + * frequency maps to (does not set the new frequency). + */ + unsigned int (*resolve_freq)(struct cpufreq_policy *policy, + unsigned int target_freq); + /* should be defined, if possible */ unsigned int (*get)(unsigned int cpu); @@ -487,6 +494,10 @@ int cpufreq_driver_target(struct cpufreq_policy *policy, int __cpufreq_driver_target(struct cpufreq_policy *policy, unsigned int target_freq, unsigned int relation); + +unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, + unsigned int target_freq); + int cpufreq_register_governor(struct cpufreq_governor *governor); void cpufreq_unregister_governor(struct cpufreq_governor *governor); -- 2.4.10