@@ -1956,6 +1956,68 @@ int pm_genpd_name_detach_cpuidle(const char *name)
return pm_genpd_detach_cpuidle(pm_genpd_lookup_name(name));
}
+/**
+ * pm_genpd_register_on_off_notifier - Register to early power on /
+ * late power off notifications.
+ * Only use this function if absolutly needed. It is only intended to be
+ * used for power domains that are coupled with the CPU, that is, power
+ * domains being controlled from cpuidle and the platform suspend ops hooks.
+ * Also only devices that needs their context to be restored directly when
+ * leaving a sleep state should use this method. Most devices should be
+ * fine handling their context and power domains via pm_runtime.
+ * @dev: Device to register.
+ * @nb: Notifier block to be registered.
+ */
+int pm_genpd_register_on_off_notifier(struct device *dev,
+ struct notifier_block *nb)
+{
+ struct generic_pm_domain *genpd;
+
+ dev_dbg(dev, "%s()\n", __func__);
+
+ genpd = dev_to_genpd(dev);
+
+ return atomic_notifier_chain_register(&genpd->on_off_notifier, nb);
+}
+
+/**
+ * pm_genpd_unregister_on_off_notifier - Unregister to early power on /
+ * late power off notification.
+ * @dev: Device to unregister.
+ * @nb: Notifier block to be unregistered.
+ */
+int pm_genpd_unregister_on_off_notifier(struct device *dev,
+ struct notifier_block *nb)
+{
+ struct generic_pm_domain *genpd;
+
+ dev_dbg(dev, "%s()\n", __func__);
+
+ genpd = dev_to_genpd(dev);
+
+ return atomic_notifier_chain_unregister(&genpd->on_off_notifier, nb);
+}
+
+/**
+ * pm_genpd_notify_power_on_off - Notify that the CPU coupled power
+ * domain is going to be powered off or has been powered on.5D
+ * Intended users of this function are cpuidle drivers and the platform
+ * suspend operations implementation.
+ * @genpd: pm domain that will change state.
+ * @power_on_off: true = has been powered on, false = will power off.
+ */
+int pm_genpd_notify_power_on_off(struct generic_pm_domain *genpd,
+ bool power_on_off)
+{
+ if (IS_ERR_OR_NULL(genpd))
+ return -EINVAL;
+
+ atomic_notifier_call_chain((&genpd->on_off_notifier),
+ power_on_off, NULL);
+
+ return 0;
+}
+
/* Default device callbacks for generic PM domains. */
/**
@@ -2137,6 +2199,7 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
atomic_set(&genpd->sd_count, 0);
genpd->status = is_off ? GPD_STATE_POWER_OFF : GPD_STATE_ACTIVE;
init_waitqueue_head(&genpd->status_wait_queue);
+ ATOMIC_INIT_NOTIFIER_HEAD(&genpd->on_off_notifier);
genpd->poweroff_task = NULL;
genpd->resume_count = 0;
genpd->device_count = 0;
@@ -82,6 +82,7 @@ struct generic_pm_domain {
bool cached_power_down_ok;
struct device_node *of_node; /* Node in device tree */
struct gpd_cpu_data *cpu_data;
+ struct atomic_notifier_head on_off_notifier;
};
static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)
@@ -159,6 +160,12 @@ extern int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state);
extern int pm_genpd_name_attach_cpuidle(const char *name, int state);
extern int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd);
extern int pm_genpd_name_detach_cpuidle(const char *name);
+extern int pm_genpd_register_on_off_notifier(struct device *dev,
+ struct notifier_block *nb);
+extern int pm_genpd_unregister_on_off_notifier(struct device *dev,
+ struct notifier_block *nb);
+extern int pm_genpd_notify_power_on_off(struct generic_pm_domain *genpd,
+ bool power_on_off);
extern void pm_genpd_init(struct generic_pm_domain *genpd,
struct dev_power_governor *gov, bool is_off);
@@ -243,6 +250,21 @@ static inline int pm_genpd_name_detach_cpuidle(const char *name)
{
return -ENOSYS;
}
+static inline int pm_genpd_register_on_off_notifier(struct device *dev,
+ struct notifier_block *nb)
+{
+ return -ENOSYS;
+}
+static inline int pm_genpd_unregister_on_off_notifier(struct device *dev,
+ struct notifier_block *nb)
+{
+ return -ENOSYS;
+}
+static inline int pm_genpd_notify_power_on_off(struct generic_pm_domain *genpd,
+ bool power_on_off)
+{
+ return -ENOSYS;
+}
static inline void pm_genpd_init(struct generic_pm_domain *genpd,
struct dev_power_governor *gov, bool is_off)
{
Some drivers needs to restore their context directly when a power domain is activated. For example a driver handling system bus settings must be able to restore context before the bus is being used for the first time. Other examples could be clock settings hardware blocks and special debugging hardware blocks which should be restored as early as possible in order to be able to debug direcly from waking up. Typically these notifers are needed in systems with CPU coupled power domains. The notifiers are intended to be trigged by cpuidle driver or the suspend ops hooks. The drivers that needs to use these notifiers are some special cases. Most drivers should not use this method and instead control their context via the pm_runtime interface. Signed-off-by: Rickard Andersson <rickard.andersson@stericsson.com> --- drivers/base/power/domain.c | 63 +++++++++++++++++++++++++++++++++++++++++++++ include/linux/pm_domain.h | 22 ++++++++++++++++ 2 files changed, 85 insertions(+)