[PATCH 07/11] pmdomain: core: Export a common ->sync_state() helper for genpd providers

Ulf Hansson
2025-04-17T14:25:45Z

In some cases the typical platform driver that act as genpd provider, may
need its own ->sync_state() callback to manage various things. In this
regards, the provider most likely wants to allow its corresponding genpds
to be powered-off.

For this reason, let's introduce a new genpd helper function,
of_genpd_sync_state() that helps genpd provider drivers to achieve this.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/pmdomain/core.c | 28 ++++++++++++++++++++++++++++
include/linux/pm_domain.h | 3 +++
2 files changed, 31 insertions(+)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 5aba66ac78f1..512f89e6d302 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -2619,6 +2619,34 @@ static bool genpd_present(const struct generic_pm_domain *genpd)
return ret;
}

+/**
+ * of_genpd_sync_state() - A common sync_state function for genpd providers
+ * @dev: The device the genpd provider is associated with.
+ *
+ * The @dev that corresponds to a genpd provider may provide one or multiple
+ * genpds. This function makes use of the device node for @dev to find the
+ * genpds that belongs to the provider. For each genpd we try a power-off.
+ */
+void of_genpd_sync_state(struct device *dev)
+{
+ struct device_node *np = dev->of_node;
+ struct generic_pm_domain *genpd;
+
+ if (!np)
+ return;
+
+ mutex_lock(&gpd_list_lock);
+ list_for_each_entry(genpd, &gpd_list, gpd_list_node) {
+ if (genpd->provider == &np->fwnode) {
+ genpd_lock(genpd);
+ genpd_power_off(genpd, false, 0);
+ genpd_unlock(genpd);
+ }
+ }
+ mutex_unlock(&gpd_list_lock);
+}
+EXPORT_SYMBOL_GPL(of_genpd_sync_state);
+
/**
* of_genpd_add_provider_simple() - Register a simple PM domain provider
* @np: Device node pointer associated with the PM domain provider.
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 0b18160901a2..e9a1f8975c4f 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -418,6 +418,7 @@ struct genpd_onecell_data {
};

#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
+void of_genpd_sync_state(struct device *dev);
int of_genpd_add_provider_simple(struct device_node *np,
struct generic_pm_domain *genpd);
int of_genpd_add_provider_onecell(struct device_node *np,
@@ -438,6 +439,8 @@ struct device *genpd_dev_pm_attach_by_id(struct device *dev,
struct device *genpd_dev_pm_attach_by_name(struct device *dev,
const char *name);
#else /* !CONFIG_PM_GENERIC_DOMAINS_OF */
+static inline void of_genpd_sync_state(struct device *dev) {}
+
static inline int of_genpd_add_provider_simple(struct device_node *np,
struct generic_pm_domain *genpd)
{
--
2.43.0