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authorNicolas Pitre <nicolas.pitre@linaro.org>2013-10-30 15:44:41 -0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2013-10-31 00:10:53 +0100
commit45cac118ffd7c9920b3d85bf551c2205674eb4f2 (patch)
treed18b9b0c1654bdf3892fdd367ff2235aad97f08d /drivers/cpufreq/arm_big_little.c
parente79a23c5b9870b7f80425793abeb10e57f7486d4 (diff)
downloadleg-kernel-45cac118ffd7c9920b3d85bf551c2205674eb4f2.tar.gz
cpufreq: arm_big_little: reconfigure switcher behavior at run time
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>
Diffstat (limited to 'drivers/cpufreq/arm_big_little.c')
-rw-r--r--drivers/cpufreq/arm_big_little.c54
1 files changed, 51 insertions, 3 deletions
diff --git a/drivers/cpufreq/arm_big_little.c b/drivers/cpufreq/arm_big_little.c
index 9986f7912328..71f1af93b585 100644
--- a/drivers/cpufreq/arm_big_little.c
+++ b/drivers/cpufreq/arm_big_little.c
@@ -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;