pm: device: runtime: add PM_DEVICE_RUNTIME_DEFAULT_ENABLE

Many SoCs which use PM_DEVICE_RUNTIME need every device in the system
to have PM_DEVICE_RUNTIME enabled to function. Currently, this is only
possible by adding zephyr,pm-device-runtime-auto; to every node in
every devicetree which could potentially implement device power
management. This is very error prone since its easy to miss a node,
especially if users apply overlays, where users need to know and
remember to apply or reapply this property.

This commit adds a Kconfig, disabled by default, which automatically
treats every device as if it had the zephyr,pm-device-runtime-auto
property added to every node.

Signed-off-by: Bjarki Arge Andreasen <[email protected]>

Author: bjarki-andreasen

subsys/pm/Kconfig

@@ -177,6 +177,15 @@ endif #PM_DEVICE_RUNTIME_USE_DEDICATED_WQ
 endchoice
 
 endif # PM_DEVICE_RUNTIME_ASYNC
+
+config PM_DEVICE_RUNTIME_DEFAULT_ENABLE
+	bool "PM device runtime enable by default"
+	help
+	  Enable PM device runtime by default for all devices when they are
+	  initialized. This option is identical to adding the devicetree
+	  property zephyr,pm-device-runtime-auto to all nodes in the
+	  devicetree.
+
 endif # PM_DEVICE_RUNTIME
 
 config PM_DEVICE_SHELL

subsys/pm/device.c

@@ -388,7 +388,8 @@ int pm_device_driver_init(const struct device *dev,
 
 	/* If device will have PM device runtime enabled */
 	if (IS_ENABLED(CONFIG_PM_DEVICE_RUNTIME) &&
-	    atomic_test_bit(&pm->flags, PM_DEVICE_FLAG_RUNTIME_AUTO)) {
+	    (IS_ENABLED(CONFIG_PM_DEVICE_RUNTIME_DEFAULT_ENABLE) ||
+	     atomic_test_bit(&pm->flags, PM_DEVICE_FLAG_RUNTIME_AUTO))) {
 		return 0;
 	}
 

subsys/pm/device_runtime.c

@@ -401,10 +401,15 @@ int pm_device_runtime_auto_enable(const struct device *dev)
 {
 	struct pm_device_base *pm = dev->pm_base;
 
-	/* No action needed if PM_DEVICE_FLAG_RUNTIME_AUTO is not enabled */
-	if (!pm || !atomic_test_bit(&pm->flags, PM_DEVICE_FLAG_RUNTIME_AUTO)) {
+	if (!pm) {
 		return 0;
 	}
+
+	if (!IS_ENABLED(CONFIG_PM_DEVICE_RUNTIME_DEFAULT_ENABLE) &&
+	    !atomic_test_bit(&pm->flags, PM_DEVICE_FLAG_RUNTIME_AUTO)) {
+		return 0;
+	}
+
 	return pm_device_runtime_enable(dev);
 }