PM / Domains: Introduce function to power off all unused PM domains

Add a new function pm_genpd_poweroff_unused() queuing up the
execution of pm_genpd_poweroff() for every initialized generic PM
domain.  Calling it will cause every generic PM domain without
devices in use to be powered off.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>

1 files changed, 21 insertions, 0 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index c3e4e2934e16..c2c537de22b6 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -16,6 +16,9 @@
 #include <linux/sched.h>
 #include <linux/suspend.h>
 
+static LIST_HEAD(gpd_list);
+static DEFINE_MUTEX(gpd_list_lock);
+
 #ifdef CONFIG_PM
 
 static struct generic_pm_domain *dev_to_genpd(struct device *dev)
@@ -1241,4 +1244,22 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
         genpd->domain.ops.restore_noirq = pm_genpd_restore_noirq;
         genpd->domain.ops.restore = pm_genpd_restore;
         genpd->domain.ops.complete = pm_genpd_complete;
+        mutex_lock(&gpd_list_lock);
+        list_add(&genpd->gpd_list_node, &gpd_list);
+        mutex_unlock(&gpd_list_lock);
+}
+
+/**
+ * pm_genpd_poweroff_unused - Power off all PM domains with no devices in use.
+ */
+void pm_genpd_poweroff_unused(void)
+{
+        struct generic_pm_domain *genpd;
+
+        mutex_lock(&gpd_list_lock);
+
+        list_for_each_entry(genpd, &gpd_list, gpd_list_node)
+                genpd_queue_power_off_work(genpd);
+
+        mutex_unlock(&gpd_list_lock);
 }