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cpufreq: arm_big_little: reconfigure switcher behavior at run time

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The b.L switcher can be turned on/off at run time.  It is therefore
necessary to change the cpufreq driver behavior accordingly.

The driver must be unregistered/registered with the cpufreq core
to reconfigure freq tables for the virtual or actual CPUs. This is
accomplished via the b.L switcher notifier callback.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Nicolas Pitre 2013-10-30 15:44:41 -04:00 committed by Rafael J. Wysocki
parent e79a23c5b9
commit 45cac118ff
1 changed files with 51 additions and 3 deletions
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54
drivers/cpufreq/arm_big_little.c
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@ -40,9 +40,12 @@
#define MAX_CLUSTERS 2
#ifdef CONFIG_BL_SWITCHER
#define is_bL_switching_enabled() true
static bool bL_switching_enabled;
#define is_bL_switching_enabled() bL_switching_enabled
#define set_switching_enabled(x) (bL_switching_enabled = (x))
#else
#define is_bL_switching_enabled() false
#define set_switching_enabled(x) do { } while (0)
#endif
#define ACTUAL_FREQ(cluster, freq) ((cluster == A7_CLUSTER) ? freq << 1 : freq)
@ -508,6 +511,38 @@ static struct cpufreq_driver bL_cpufreq_driver = {
.attr = cpufreq_generic_attr,
};
static int bL_cpufreq_switcher_notifier(struct notifier_block *nfb,
unsigned long action, void *_arg)
{
pr_debug("%s: action: %ld\n", __func__, action);
switch (action) {
case BL_NOTIFY_PRE_ENABLE:
case BL_NOTIFY_PRE_DISABLE:
cpufreq_unregister_driver(&bL_cpufreq_driver);
break;
case BL_NOTIFY_POST_ENABLE:
set_switching_enabled(true);
cpufreq_register_driver(&bL_cpufreq_driver);
break;
case BL_NOTIFY_POST_DISABLE:
set_switching_enabled(false);
cpufreq_register_driver(&bL_cpufreq_driver);
break;
default:
return NOTIFY_DONE;
}
return NOTIFY_OK;
}
static struct notifier_block bL_switcher_notifier = {
.notifier_call = bL_cpufreq_switcher_notifier,
};
int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
{
int ret, i;
@ -525,6 +560,9 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
arm_bL_ops = ops;
ret = bL_switcher_get_enabled();
set_switching_enabled(ret);
for (i = 0; i < MAX_CLUSTERS; i++)
mutex_init(&cluster_lock[i]);
@ -534,10 +572,17 @@ int bL_cpufreq_register(struct cpufreq_arm_bL_ops *ops)
__func__, ops->name, ret);
arm_bL_ops = NULL;
} else {
pr_info("%s: Registered platform driver: %s\n", __func__,
ops->name);
ret = bL_switcher_register_notifier(&bL_switcher_notifier);
if (ret) {
cpufreq_unregister_driver(&bL_cpufreq_driver);
arm_bL_ops = NULL;
} else {
pr_info("%s: Registered platform driver: %s\n",
__func__, ops->name);
}
}
bL_switcher_put_enabled();
return ret;
}
EXPORT_SYMBOL_GPL(bL_cpufreq_register);
@ -550,7 +595,10 @@ void bL_cpufreq_unregister(struct cpufreq_arm_bL_ops *ops)
return;
}
bL_switcher_get_enabled();
bL_switcher_unregister_notifier(&bL_switcher_notifier);
cpufreq_unregister_driver(&bL_cpufreq_driver);
bL_switcher_put_enabled();
pr_info("%s: Un-registered platform driver: %s\n", __func__,
arm_bL_ops->name);
arm_bL_ops = NULL;