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 firmware 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 ->fwnode
pointer in the struct generic_pm_domain, to enable pm_genpd_lookup() to
find the domain.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
Changes in v2:
Change from using struct device_node to struct fwnode_handle.
Updated commit header accordingly.
---
drivers/base/power/domain.c | 27 +++++++++++++++++++++++++++
include/linux/pm_domain.h | 4 ++++
2 files changed, 31 insertions(+)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 735c473..2d881d5 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -75,6 +75,33 @@ 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 firmware node.
+ * @node: Firmware 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 fwnode_handle *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->fwnode == 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,
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 8cbd32e..aa01050 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -43,6 +43,8 @@ struct gpd_cpuidle_data {
struct cpuidle_state *idle_state;
};
+struct fwnode_handle;
+
struct generic_pm_domain {
struct dev_pm_domain domain; /* PM domain operations */
struct list_head gpd_list_node; /* Node in the global PM domains list */
@@ -53,6 +55,7 @@ struct generic_pm_domain {
struct dev_power_governor *gov;
struct work_struct power_off_work;
const char *name;
+ struct fwnode_handle *fwnode; /* Firware 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 +129,7 @@ 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 fwnode_handle *node);
extern int __pm_genpd_add_device(struct generic_pm_domain *genpd,
struct device *dev,
struct gpd_timing_data *td);
--
1.9.1
--
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