pmdomain: core: Export a common ->sync_state() helper for genpd providers

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.

Suggested-by: Saravana Kannan <saravanak@google.com>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Tested-by: Hiago De Franco <hiago.franco@toradex.com> # Colibri iMX8X
Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> # TI AM62A,Xilinx ZynqMP ZCU106
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20250701114733.636510-8-ulf.hansson@linaro.org

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 79dc0bf406f0bdd3f3db65ec206f6e4ed2d03d08..0a6593a1b1c8d6a9d4f50555c17e7d1d4a2a89ae 100644 (file)
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -3396,6 +3396,33 @@ int of_genpd_parse_idle_states(struct device_node *dn,
 }
 EXPORT_SYMBOL_GPL(of_genpd_parse_idle_states);
 
+/**
+ * of_genpd_sync_state() - A common sync_state function for genpd providers
+ * @np: The device node the genpd provider is associated with.
+ *
+ * The @np that corresponds to a genpd provider may provide one or multiple
+ * genpds. This function makes use @np to find the genpds that belongs to the
+ * provider. For each genpd we try a power-off.
+ */
+void of_genpd_sync_state(struct device_node *np)
+{
+       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 == of_fwnode_handle(np)) {
+                       genpd_lock(genpd);
+                       genpd_power_off(genpd, false, 0);
+                       genpd_unlock(genpd);
+               }
+       }
+       mutex_unlock(&gpd_list_lock);
+}
+EXPORT_SYMBOL_GPL(of_genpd_sync_state);
+
 static int genpd_provider_probe(struct device *dev)
 {
        return 0;

diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 0b18160901a2c9ea4281118f00d17ae803327316..3578196e6626ba9de1e357880046ecc0762507da 100644 (file)
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -431,6 +431,7 @@ int of_genpd_remove_subdomain(const struct of_phandle_args *parent_spec,
 struct generic_pm_domain *of_genpd_remove_last(struct device_node *np);
 int of_genpd_parse_idle_states(struct device_node *dn,
                               struct genpd_power_state **states, int *n);
+void of_genpd_sync_state(struct device_node *np);
 
 int genpd_dev_pm_attach(struct device *dev);
 struct device *genpd_dev_pm_attach_by_id(struct device *dev,
@@ -476,6 +477,8 @@ static inline int of_genpd_parse_idle_states(struct device_node *dn,
        return -ENODEV;
 }
 
+static inline void of_genpd_sync_state(struct device_node *np) {}
+
 static inline int genpd_dev_pm_attach(struct device *dev)
 {
        return 0;