PM / Domains: Document cpuidle-related functions and change their names

The names of the cpuidle-related functions in
drivers/base/power/domain.c are inconsistent with the names of the
other exported functions in that file (the "pm_" prefix is missing
from them) and they are missing kerneldoc comments.

Fix that by adding the missing "pm_" prefix to the names of those
functions and add kerneldoc comments documenting them.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

drivers/base/power/domain.c

@@ -1829,7 +1829,16 @@ int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td)
 }
 EXPORT_SYMBOL_GPL(__pm_genpd_remove_callbacks);
 
-int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
+/**
+ * pm_genpd_attach_cpuidle - Connect the given PM domain with cpuidle.
+ * @genpd: PM domain to be connected with cpuidle.
+ * @state: cpuidle state this domain can disable/enable.
+ *
+ * Make a PM domain behave as though it contained a CPU core, that is, instead
+ * of calling its power down routine it will enable the given cpuidle state so
+ * that the cpuidle subsystem can power it down (if possible and desirable).
+ */
+int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
 {
 	struct cpuidle_driver *cpuidle_drv;
 	struct gpd_cpu_data *cpu_data;
@@ -1878,7 +1887,14 @@ int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state)
 	goto out;
 }
 
-int genpd_detach_cpuidle(struct generic_pm_domain *genpd)
+/**
+ * pm_genpd_detach_cpuidle - Remove the cpuidle connection from a PM domain.
+ * @genpd: PM domain to remove the cpuidle connection from.
+ *
+ * Remove the cpuidle connection set up by pm_genpd_attach_cpuidle() from the
+ * given PM domain.
+ */
+int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
 {
 	struct gpd_cpu_data *cpu_data;
 	struct cpuidle_state *idle_state;

include/linux/pm_domain.h

@@ -155,8 +155,8 @@ extern int pm_genpd_add_callbacks(struct device *dev,
 				  struct gpd_dev_ops *ops,
 				  struct gpd_timing_data *td);
 extern int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td);
-extern int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state);
-extern int genpd_detach_cpuidle(struct generic_pm_domain *genpd);
+extern int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int state);
+extern int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd);
 extern void pm_genpd_init(struct generic_pm_domain *genpd,
 			  struct dev_power_governor *gov, bool is_off);
 
@@ -225,11 +225,11 @@ static inline int __pm_genpd_remove_callbacks(struct device *dev, bool clear_td)
 {
 	return -ENOSYS;
 }
-static inline int genpd_attach_cpuidle(struct generic_pm_domain *genpd, int st)
+static inline int pm_genpd_attach_cpuidle(struct generic_pm_domain *genpd, int st)
 {
 	return -ENOSYS;
 }
-static inline int genpd_detach_cpuidle(struct generic_pm_domain *genpd)
+static inline int pm_genpd_detach_cpuidle(struct generic_pm_domain *genpd)
 {
 	return -ENOSYS;
 }