Ideally, if we are returning a reference to a PM domain via a call to
of_genpd_get_from_provider(), then we should keep track of such
references via a reference count. The reference count could then be used
to determine if a PM domain can be safely removed. Alternatively, it is
possible to avoid such external references by providing APIs to access
the PM domain and hence, eliminate any calls to
of_genpd_get_from_provider().
Add new helper functions for adding a device and a subdomain to a PM
domain when using device-tree, so that external calls to
of_genpd_get_from_provider() can be removed.
Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
---
drivers/base/power/domain.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_domain.h | 16 ++++++++++++++++
2 files changed, 60 insertions(+)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 5bdb42bf40f4..b24893499454 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1706,6 +1706,50 @@ struct generic_pm_domain *of_genpd_get_from_provider(
EXPORT_SYMBOL_GPL(of_genpd_get_from_provider);
/**
+ * of_genpd_add_device() - Add a device to an I/O PM domain
+ * @genpdspec: OF phandle args to use for look-up PM domain
+ * @dev: Device to be added.
+ *
+ * Looks-up an I/O PM domain based upon phandle args provided and adds
+ * the device to the PM domain. Returns a negative error code on failure.
+ */
+int of_genpd_add_device(struct of_phandle_args *genpdspec, struct device *dev)
+{
+ struct generic_pm_domain *genpd;
+
+ genpd = of_genpd_get_from_provider(genpdspec);
+ if (IS_ERR(genpd))
+ return PTR_ERR(genpd);
+
+ return pm_genpd_add_device(genpd, dev);
+}
+
+/**
+ * of_genpd_add_subdomain - Add a subdomain to an I/O PM domain.
+ * @parent_spec: OF phandle args to use for parent PM domain look-up
+ * @subdomain_spec: OF phandle args to use for subdomain look-up
+ *
+ * Looks-up a parent PM domain and subdomain based upon phandle args
+ * provided and adds the subdomain to the parent PM domain. Returns a
+ * negative error code on failure.
+ */
+int of_genpd_add_subdomain(struct of_phandle_args *parent_spec,
+ struct of_phandle_args *subdomain_spec)
+{
+ struct generic_pm_domain *parent, *subdomain;
+
+ parent = of_genpd_get_from_provider(parent_spec);
+ if (IS_ERR(parent))
+ return PTR_ERR(parent);
+
+ subdomain = of_genpd_get_from_provider(subdomain_spec);
+ if (IS_ERR(subdomain))
+ return PTR_ERR(subdomain);
+
+ return pm_genpd_add_subdomain(parent, subdomain);
+}
+
+/**
* genpd_dev_pm_detach - Detach a device from its PM domain.
* @dev: Device to detach.
* @power_off: Currently not used
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 49cd8890b873..2b6ee670b231 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -210,6 +210,10 @@ struct generic_pm_domain *__of_genpd_xlate_simple(
struct generic_pm_domain *__of_genpd_xlate_onecell(
struct of_phandle_args *genpdspec,
void *data);
+extern int of_genpd_add_device(struct of_phandle_args *args,
+ struct device *dev);
+extern int of_genpd_add_subdomain(struct of_phandle_args *parent,
+ struct of_phandle_args *new_subdomain);
int genpd_dev_pm_attach(struct device *dev);
#else /* !CONFIG_PM_GENERIC_DOMAINS_OF */
@@ -229,6 +233,18 @@ static inline struct generic_pm_domain *of_genpd_get_from_provider(
#define __of_genpd_xlate_simple NULL
#define __of_genpd_xlate_onecell NULL
+static inline int of_pm_genpd_add_device(struct of_phandle_args *args,
+ struct device *dev)
+{
+ return -ENODEV;
+}
+
+static inline int of_genpd_add_subdomain(struct of_phandle_args *parent,
+ struct of_phandle_args *new_subdomain)
+{
+ return -ENODEV;
+}
+
static inline int genpd_dev_pm_attach(struct device *dev)
{
return -ENODEV;
--
2.1.4
--
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