@@ -75,6 +75,32 @@ struct generic_pm_domain *dev_to_genpd(struct device *dev)
return pd_to_genpd(dev->pm_domain);
}
+/**
+ * pm_genpd_lookup - Fetch a generic PM domain object by device node
+ * @node: Device node to a corresponding genpd.
+ *
+ * Returns a valid pointer to struct generic_pm_domain on success or ERR_PTR()
+ * on failure.
+ */
+struct generic_pm_domain *pm_genpd_lookup(struct device_node *node)
+{
+ struct generic_pm_domain *genpd = ERR_PTR(-ENOENT), *gpd;
+
+ if (IS_ERR_OR_NULL(node))
+ return ERR_PTR(-EINVAL);
+
+ mutex_lock(&gpd_list_lock);
+ list_for_each_entry(gpd, &gpd_list, gpd_list_node) {
+ if (gpd->dev_node == node) {
+ genpd = gpd;
+ break;
+ }
+ }
+ mutex_unlock(&gpd_list_lock);
+ return genpd;
+}
+EXPORT_SYMBOL_GPL(pm_genpd_lookup);
+
static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
{
return GENPD_DEV_TIMED_CALLBACK(genpd, int, stop, dev,
@@ -53,6 +53,7 @@ struct generic_pm_domain {
struct dev_power_governor *gov;
struct work_struct power_off_work;
const char *name;
+ struct device_node *dev_node; /* Device node for the PM domain */
unsigned int in_progress; /* Number of devices being suspended now */
atomic_t sd_count; /* Number of subdomains with power "on" */
enum gpd_status status; /* Current state of the domain */
@@ -126,6 +127,7 @@ static inline struct generic_pm_domain_data *dev_gpd_data(struct device *dev)
}
extern struct generic_pm_domain *dev_to_genpd(struct device *dev);
+extern struct generic_pm_domain *pm_genpd_lookup(struct device_node *node);
extern int __pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev,
struct gpd_timing_data *td);
In a step to move away from using genpd's name based APIs, such as the pm_genpd_add_subdomain_names(), provide an API to lookup an already initialized generic PM domain by its device node. This API would typically be a called from SOC specific code, to fetch a handle to the domain. Especially convenient to configure subdomains and when the hierarchy of the domains are described in DT. Do note, before pm_genpd_init() is invoked to initialize a generic PM domain, it's the callers responsibility to assign the new ->dev_node pointer in the struct generic_pm_domain, to enable pm_genpd_lookup() to find the domain. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> --- The background to why I propose this patch comes from a discussion around the below patchset: https://lkml.org/lkml/2014/11/24/290 --- drivers/base/power/domain.c | 26 ++++++++++++++++++++++++++ include/linux/pm_domain.h | 2 ++ 2 files changed, 28 insertions(+)