[PATCH v2 1/4] of: Rename "poweroff-source" property to "system-power-controller"

[Romain Perier <romain.perier@gmail.com>]

As discussed on the mailing list, it makes more sense to rename this property
to "system-power-controller". Problem being that the word "source" usually tends
to be used for inputs and that is out of control of the OS. The poweroff
capability is an output which simply turns the system-power off. Also, this
property might be used by drivers which power-off the system and power back on
subsequent RTC alarms. This seems to suggest to remove "poweroff" from the
property name and to choose "system-power-controller" as the more generic name.
This patchs adds the required renaming changes and defines an helper function
which is compatible with both properties, the old one prefixed by a vendor name
and the new one without any prefix.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
---
 .../devicetree/bindings/power/power-controller.txt | 18 ++++++++++++
 .../devicetree/bindings/power/poweroff.txt         | 18 ------------
 drivers/of/base.c                                  | 34 ++++++++++++++++++++++
 include/linux/of.h                                 | 10 ++-----
 4 files changed, 55 insertions(+), 25 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/power/power-controller.txt
 delete mode 100644 Documentation/devicetree/bindings/power/poweroff.txt

diff --git a/Documentation/devicetree/bindings/power/power-controller.txt b/Documentation/devicetree/bindings/power/power-controller.txt
new file mode 100644
index 0000000..942f955
--- /dev/null
+++ b/Documentation/devicetree/bindings/power/power-controller.txt
@@ -0,0 +1,18 @@
+* Generic system power control capability
+
+Power-management integrated circuits or miscellaneous harware components are
+sometimes able to control the system power. The device driver associated to these
+components might needs to define this capability, which tells to the kernel how
+to switch off the system. The corresponding driver must have the standard
+property "system-power-controller" in its device node. This property marks the
+device as able to controller the system-power. In order to test if this property
+is found programmatically, use the helper function "of_is_system_power_controller"
+from of.h .
+
+Example:
+
+act8846: act8846@5 {
+	 compatible = "active-semi,act8846";
+	 status = "okay";
+	 system-power-controller;
+}
diff --git a/Documentation/devicetree/bindings/power/poweroff.txt b/Documentation/devicetree/bindings/power/poweroff.txt
deleted file mode 100644
index 845868b..0000000
--- a/Documentation/devicetree/bindings/power/poweroff.txt
+++ /dev/null
@@ -1,18 +0,0 @@
-* Generic Poweroff capability
-
-Power-management integrated circuits or miscellaneous harware components are
-sometimes able to control the system power. The device driver associated to these
-components might needs to define poweroff capability, which tells to the kernel
-how to switch off the system. The corresponding driver must have the standard
-property "poweroff-source" in its device node. This property marks the device as
-able to shutdown the system. In order to test if this property is found
-programmatically, use the helper function "of_system_has_poweroff_source" from
-of.h .
-
-Example:
-
-act8846: act8846@5 {
-	 compatible = "active-semi,act8846";
-	 status = "okay";
-	 poweroff-source;
-}
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 74ab1b8..438e405 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2260,3 +2260,37 @@ struct device_node *of_graph_get_remote_port(const struct device_node *node)
 	return of_get_next_parent(np);
 }
 EXPORT_SYMBOL(of_graph_get_remote_port);
+
+/**
+ * of_is_system_power_controller() - Tells if the property for controlling system
+ * power is found in device_node.
+ * @np: Pointer to the given device_node
+ *
+ * Return: true if present false otherwise
+ */
+bool of_is_system_power_controller(const struct device_node *np)
+{
+	struct property *pp;
+	unsigned long flags;
+	char *sep;
+	bool found = false;
+
+	raw_spin_lock_irqsave(&devtree_lock, flags);
+	for_each_property_of_node(np, pp) {
+		if (of_prop_cmp(pp->name, "system-power-controller") == 0) {
+			found = true;
+			break;
+		}
+		/* Backward compatibility with previous property "vendor,system-power-controller",
+		 * we just check that an non-empty vendor-prefix exists here
+		 */
+		sep = strchr(pp->name, ',');
+		if (sep && sep - pp->name && of_prop_cmp(sep + 1, "system-power-controller") == 0) {
+			found = true;
+			break;
+		}
+	}
+	raw_spin_unlock_irqrestore(&devtree_lock, flags);
+	return found;
+}
+EXPORT_SYMBOL(of_is_system_power_controller);
diff --git a/include/linux/of.h b/include/linux/of.h
index 868fdad..e7177b3 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -910,15 +910,11 @@ static inline int of_changeset_update_property(struct of_changeset *ocs,
 /* CONFIG_OF_RESOLVE api */
 extern int of_resolve_phandles(struct device_node *tree);
 
-/**
- * of_system_has_poweroff_source - Tells if poweroff-source is found for device_node
- * @np: Pointer to the given device_node
- *
- * return true if present false otherwise
- */
+bool of_is_system_power_controller(const struct device_node *np);
+
 static inline bool of_system_has_poweroff_source(const struct device_node *np)
 {
-	return of_property_read_bool(np, "poweroff-source");
+	return of_is_system_power_controller(np);
 }
 
 #endif /* _LINUX_OF_H */
-- 
1.9.1