@@ -53,3 +53,17 @@ NULL). To register and/or unregister a suspend notifier use the functions
register_pm_notifier() and unregister_pm_notifier(), respectively, defined in
include/linux/suspend.h . If you don't need to unregister the notifier, you can
also use the pm_notifier() macro defined in include/linux/suspend.h .
+
+Power Domain notifiers
+----------------------
+
+The power domain notifiers allow subsystems or drivers to register for power
+domain on/off notifications, should they need to perform any actions right
+before or right after the power domain on/off. The device must be already
+added to a power domain before its subsystem or driver registers the notifier.
+Following events are supported:
+
+GPD_NOTIFY_POWER_ON_PREPARE The power domain is about to turn on.
+GPD_NOTIFY_POST_POWER_ON The power domain has just turned on.
+GPD_NOTIFY_POWER_OFF_PREPARE The power domain is about to turn off.
+GPD_NOTIFY_POST_POWER_OFF The power domain has just turned off.
@@ -67,6 +67,110 @@ static struct generic_pm_domain *pm_genpd_lookup_name(const char *domain_name)
return genpd;
}
+static int __pm_genpd_do_register_notifier(struct generic_pm_domain *genpd,
+ struct gpd_notifier_block *gpd_nb)
+{
+ int ret;
+
+ if (IS_ERR_OR_NULL(genpd) || gpd_nb == NULL)
+ return -EINVAL;
+
+ mutex_lock(&genpd->lock);
+ ret = blocking_notifier_chain_cond_register(&genpd->notify_chain_head,
+ &gpd_nb->nb);
+ mutex_unlock(&genpd->lock);
+ return ret;
+}
+
+/**
+ * pm_genpd_register_notifier - Register notifier for the power domain
+ * state transitions.
+ *
+ * @dev: Device attached to a power domain the state transitions are to be
+ * notified for.
+ * @gpd_nb: The notifier chain entry to be registered
+ */
+int pm_genpd_register_notifier(struct device *dev,
+ struct gpd_notifier_block *gpd_nb)
+{
+ struct generic_pm_domain *genpd = dev_to_genpd(dev);
+
+ return __pm_genpd_do_register_notifier(genpd, gpd_nb);
+}
+EXPORT_SYMBOL_GPL(pm_genpd_register_notifier);
+
+/**
+ * pm_genpd_name_register_notifier - Register a notifier for the power domain
+ * state transitions.
+ *
+ * @domain_name: Name of the power domain the notifier is to be registered for.
+ * @gpd_nb: The notifier chain entry to be registered.
+ *
+ */
+int pm_genpd_name_register_notifier(const char *domain_name,
+ struct gpd_notifier_block *gpd_nb)
+{
+ struct generic_pm_domain *genpd = pm_genpd_lookup_name(domain_name);
+
+ return __pm_genpd_do_register_notifier(genpd, gpd_nb);
+}
+EXPORT_SYMBOL(pm_genpd_name_register_notifier);
+
+static void __pm_genpd_unregister_notifier(struct generic_pm_domain *genpd,
+ struct gpd_notifier_block *gpd_nb)
+{
+ if (IS_ERR_OR_NULL(genpd) || gpd_nb == NULL)
+ return;
+
+ mutex_lock(&genpd->lock);
+ blocking_notifier_chain_unregister(&genpd->notify_chain_head,
+ &gpd_nb->nb);
+ mutex_unlock(&genpd->lock);
+}
+
+/**
+ * pm_genpd_unregister_notifier - Unregister a power domain state notifier
+ *
+ * @dev: Device bound to a power domain the notifier is to be unregistered for.
+ * @gpd_nb: The notifier chain entry to be unregistered.
+ */
+void pm_genpd_unregister_notifier(struct device *dev,
+ struct gpd_notifier_block *gpd_nb)
+{
+ struct generic_pm_domain *genpd = dev_to_genpd(dev);
+
+ __pm_genpd_unregister_notifier(genpd, gpd_nb);
+}
+EXPORT_SYMBOL_GPL(pm_genpd_unregister_notifier);
+
+/**
+ * pm_genpd_name_unregister_notifier - Unregister a power domain state notifier
+ *
+ * @domain_name: Name of a power domain of which notifier is to be
+ * unregistered.
+ * @gpd_nb: The notifier chain entry to be unregistered.
+ */
+void pm_genpd_name_unregister_notifier(const char *domain_name,
+ struct gpd_notifier_block *gpd_nb)
+{
+ struct generic_pm_domain *genpd = pm_genpd_lookup_name(domain_name);
+
+ __pm_genpd_unregister_notifier(genpd, gpd_nb);
+}
+EXPORT_SYMBOL_GPL(pm_genpd_name_unregister_notifier);
+
+/**
+ * pm_genpd_notifier_call - Call the power domain state transition notify chain
+ *
+ * @event: The state transition event type.
+ * @genpd: The power domain to notify state transition for.
+ */
+static inline void pm_genpd_notifier_call(unsigned long event,
+ struct generic_pm_domain *genpd)
+{
+ blocking_notifier_call_chain(&genpd->notify_chain_head, event, genpd);
+}
+
struct generic_pm_domain *dev_to_genpd(struct device *dev)
{
if (IS_ERR_OR_NULL(dev->pm_domain))
@@ -226,10 +330,14 @@ static int __pm_genpd_poweron(struct generic_pm_domain *genpd)
ktime_t time_start = ktime_get();
s64 elapsed_ns;
+ pm_genpd_notifier_call(GPD_NOTIFY_POWER_ON_PREPARE, genpd);
+
ret = genpd->power_on(genpd);
if (ret)
goto err;
+ pm_genpd_notifier_call(GPD_NOTIFY_POST_POWER_ON, genpd);
+
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
if (elapsed_ns > genpd->power_on_latency_ns) {
genpd->power_on_latency_ns = elapsed_ns;
@@ -547,6 +655,8 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
* the pm_genpd_poweron() restore power for us (this shouldn't
* happen very often).
*/
+ pm_genpd_notifier_call(GPD_NOTIFY_POWER_OFF_PREPARE, genpd);
+
ret = genpd->power_off(genpd);
if (ret == -EBUSY) {
genpd_set_active(genpd);
@@ -554,6 +664,9 @@ static int pm_genpd_poweroff(struct generic_pm_domain *genpd)
}
elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
+
+ pm_genpd_notifier_call(GPD_NOTIFY_POST_POWER_OFF, genpd);
+
if (elapsed_ns > genpd->power_off_latency_ns) {
genpd->power_off_latency_ns = elapsed_ns;
genpd->max_off_time_changed = true;
@@ -796,9 +909,13 @@ static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd)
|| atomic_read(&genpd->sd_count) > 0)
return;
- if (genpd->power_off)
+ if (genpd->power_off) {
+ pm_genpd_notifier_call(GPD_NOTIFY_POWER_OFF_PREPARE, genpd);
genpd->power_off(genpd);
+ pm_genpd_notifier_call(GPD_NOTIFY_POST_POWER_OFF, genpd);
+ }
+
genpd->status = GPD_STATE_POWER_OFF;
list_for_each_entry(link, &genpd->slave_links, slave_node) {
@@ -828,8 +945,11 @@ static void pm_genpd_sync_poweron(struct generic_pm_domain *genpd)
genpd_sd_counter_inc(link->master);
}
- if (genpd->power_on)
+ if (genpd->power_on) {
+ pm_genpd_notifier_call(GPD_NOTIFY_POWER_ON_PREPARE, genpd);
genpd->power_on(genpd);
+ pm_genpd_notifier_call(GPD_NOTIFY_POST_POWER_ON, genpd);
+ }
genpd->status = GPD_STATE_ACTIVE;
}
@@ -1251,9 +1371,16 @@ static int pm_genpd_restore_noirq(struct device *dev)
* If the domain was off before the hibernation, make
* sure it will be off going forward.
*/
- if (genpd->power_off)
- genpd->power_off(genpd);
+ if (!genpd->power_off)
+ return 0;
+
+ pm_genpd_notifier_call(GPD_NOTIFY_POWER_OFF_PREPARE,
+ genpd);
+
+ genpd->power_off(genpd);
+ pm_genpd_notifier_call(GPD_NOTIFY_POST_POWER_OFF,
+ genpd);
return 0;
}
}
@@ -1867,6 +1994,7 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
INIT_LIST_HEAD(&genpd->master_links);
INIT_LIST_HEAD(&genpd->slave_links);
INIT_LIST_HEAD(&genpd->dev_list);
+ BLOCKING_INIT_NOTIFIER_HEAD(&genpd->notify_chain_head);
mutex_init(&genpd->lock);
genpd->gov = gov;
INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
@@ -17,6 +17,12 @@
#include <linux/notifier.h>
#include <linux/cpuidle.h>
+/* PM domain state transition notifications */
+#define GPD_NOTIFY_POWER_ON_PREPARE 0x01
+#define GPD_NOTIFY_POST_POWER_ON 0x02
+#define GPD_NOTIFY_POWER_OFF_PREPARE 0x03
+#define GPD_NOTIFY_POST_POWER_OFF 0x04
+
enum gpd_status {
GPD_STATE_ACTIVE = 0, /* PM domain is active */
GPD_STATE_WAIT_MASTER, /* PM domain's master is being waited for */
@@ -49,6 +55,7 @@ struct generic_pm_domain {
struct list_head master_links; /* Links with PM domain as a master */
struct list_head slave_links; /* Links with PM domain as a slave */
struct list_head dev_list; /* List of devices */
+ struct blocking_notifier_head notify_chain_head;
struct mutex lock;
struct dev_power_governor *gov;
struct work_struct power_off_work;
@@ -107,6 +114,20 @@ struct generic_pm_domain_data {
bool need_restore;
};
+struct gpd_notifier_block {
+ struct notifier_block nb;
+ /* The notification's user private data */
+ void *data;
+};
+
+static inline void *gpd_get_nb_data(struct notifier_block *nb)
+{
+ struct gpd_notifier_block *genpd_nb;
+
+ genpd_nb = container_of(nb, struct gpd_notifier_block, nb);
+ return genpd_nb->data;
+}
+
#ifdef CONFIG_PM_GENERIC_DOMAINS
static inline struct generic_pm_domain_data *to_gpd_data(struct pm_domain_data *pdd)
{
@@ -146,6 +167,15 @@ extern void pm_genpd_init(struct generic_pm_domain *genpd,
extern int pm_genpd_poweron(struct generic_pm_domain *genpd);
extern int pm_genpd_name_poweron(const char *domain_name);
+extern int pm_genpd_register_notifier(struct device *dev,
+ struct gpd_notifier_block *gpd_nb);
+extern int pm_genpd_name_register_notifier(const char *domain_name,
+ struct gpd_notifier_block *gpd_nb);
+extern void pm_genpd_unregister_notifier(struct device *dev,
+ struct gpd_notifier_block *gpd_nb);
+extern void pm_genpd_name_unregister_notifier(const char *domain_name,
+ struct gpd_notifier_block *gpd_nb);
+
extern struct dev_power_governor simple_qos_governor;
extern struct dev_power_governor pm_domain_always_on_gov;
#else
@@ -219,6 +249,22 @@ static inline int pm_genpd_name_poweron(const char *domain_name)
{
return -ENOSYS;
}
+static inline int pm_genpd_register_notifier(struct device *dev,
+ struct gpd_notifier_block *genpd_nb)
+{
+ return -ENOSYS;
+}
+
+static int pm_genpd_name_register_notifier(const char *domain_name,
+ struct gpd_notifier_block *genpd_nb)
+{
+ return -ENOSYS;
+}
+
+static inline void pm_genpd_unregister_notifier(struct device *dev,
+ struct gpd_notifier_block *genpd_nb) {}
+static inline void pm_genpd_name_unregister_notifier(const char *domain_name,
+ struct gpd_notifier_block *genpd_nb) {}
#define simple_qos_governor NULL
#define pm_domain_always_on_gov NULL
#endif