diff options
| author | Steve Muckle <steve.muckle@linaro.org> | 2016-07-13 13:25:25 -0700 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2016-07-21 14:46:08 +0200 |
| commit | e3c06236087051d5c62d60d0668588c370fda887 (patch) | |
| tree | 87bf8e5a9b77cb24d416851136451aaf43f27fd1 /include/linux/cpufreq.h | |
| parent | da7de91c3e237f3ace1aa29b82c69702dc0176c5 (diff) | |
cpufreq: add cpufreq_driver_resolve_freq()
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(). This API returns the lowest driver
frequency equal or greater than the target frequency
(CPUFREQ_RELATION_L), subject to any policy (min/max) or driver
limitations. The mapping is also cached in the policy so that a
subsequent fast_switch operation can avoid repeating the same lookup.
The API will call a new cpufreq driver callback, resolve_freq(), if it
has been registered by the driver. Otherwise the frequency is resolved
via cpufreq_frequency_table_target(). Rather than require ->target()
style drivers to provide a resolve_freq() callback it is left to the
caller to ensure that the driver implements this callback if necessary
to use cpufreq_driver_resolve_freq().
Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Steve Muckle <smuckle@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'include/linux/cpufreq.h')
| -rw-r--r-- | include/linux/cpufreq.h | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index c6410b1b2490..631ba33bbe9f 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -120,6 +120,10 @@ struct cpufreq_policy { bool fast_switch_possible; bool fast_switch_enabled; + /* Cached frequency lookup from cpufreq_driver_resolve_freq. */ + unsigned int cached_target_freq; + int cached_resolved_idx; + /* Synchronization for frequency transitions */ bool transition_ongoing; /* Tracks transition status */ spinlock_t transition_lock; @@ -270,6 +274,16 @@ struct cpufreq_driver { unsigned int index); unsigned int (*fast_switch)(struct cpufreq_policy *policy, unsigned int target_freq); + + /* + * Caches and returns the lowest driver-supported frequency greater than + * or equal to the target frequency, subject to any driver limitations. + * Does not set the frequency. Only to be implemented for drivers with + * target(). + */ + unsigned int (*resolve_freq)(struct cpufreq_policy *policy, + unsigned int target_freq); + /* * Only for drivers with target_index() and CPUFREQ_ASYNC_NOTIFICATION * unset. @@ -501,6 +515,8 @@ 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); |