[PATCH 1/3] of: add device node status update APIs
Dong Aisheng
b29396 at freescale.com
Thu Aug 15 06:55:31 EDT 2013
Used for convineniently update the device node status.
Signed-off-by: Dong Aisheng <b29396 at freescale.com>
---
drivers/of/base.c | 74 ++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/of.h | 5 +++
2 files changed, 79 insertions(+), 0 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 5c54279..f944a54 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1424,6 +1424,80 @@ int of_update_property(struct device_node *np, struct property *newprop)
return 0;
}
+/* update the node status property to be "enabled" or "disabled" */
+static int of_node_status_update(struct device_node *np, bool enable)
+{
+ struct property *oldprop;
+ struct property *newprop;
+ int ret;
+
+ if (of_device_is_available(np) == enable)
+ return 0;
+
+ oldprop = of_find_property(np, "status", NULL);
+
+ if (enable) {
+ /* for disabled node, there must be a status property with "disabled" state */
+ ret = of_remove_property(np, oldprop);
+ } else {
+ newprop = kzalloc(sizeof(*newprop), GFP_KERNEL);
+ if (!newprop)
+ return -ENOMEM;
+
+ newprop->name = kstrdup("status", GFP_KERNEL);
+ newprop->value = kstrdup("disabled", GFP_KERNEL);
+ newprop->length = 9;
+ if (!newprop->name || !newprop->value) {
+ kfree(newprop->name);
+ kfree(newprop->value);
+ kfree(newprop);
+ return -ENOMEM;
+ }
+
+ ret = of_update_property(np, newprop);
+ }
+
+ pr_debug("%s: %s --> %s %s\n", np->full_name, enable ?
+ "disabled" : "enabled", enable ? "enabled" : "disabled",
+ ret ? "failed" : "okay");
+
+ return ret;
+}
+
+int of_node_status_disable(struct device_node *np)
+{
+ return of_node_status_update(np, 0);
+}
+
+int of_node_status_enable(struct device_node *np)
+{
+ return of_node_status_update(np, 1);
+}
+
+int of_node_status_disable_by_path(const char *path)
+{
+ struct device_node *np;
+
+ pr_debug("disable node: %s\n", path);
+ np = of_find_node_by_path(path);
+ if (!np)
+ return -ENODEV;
+
+ return of_node_status_update(np, 0);
+}
+
+int of_node_status_enable_by_path(const char *path)
+{
+ struct device_node *np;
+
+ pr_debug("enable node: %s\n", path);
+ np = of_find_node_by_path(path);
+ if (!np)
+ return -ENODEV;
+
+ return of_node_status_update(np, 1);
+}
+
#if defined(CONFIG_OF_DYNAMIC)
/*
* Support for dynamic device trees.
diff --git a/include/linux/of.h b/include/linux/of.h
index 1fd08ca..61b35fe 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -292,6 +292,11 @@ extern int of_add_property(struct device_node *np, struct property *prop);
extern int of_remove_property(struct device_node *np, struct property *prop);
extern int of_update_property(struct device_node *np, struct property *newprop);
+extern int of_node_status_disable(struct device_node *np);
+extern int of_node_status_enable(struct device_node *np);
+extern int of_node_status_disable_by_path(const char *path);
+extern int of_node_status_enable_by_path(const char *path);
+
/* For updating the device tree at runtime */
#define OF_RECONFIG_ATTACH_NODE 0x0001
#define OF_RECONFIG_DETACH_NODE 0x0002
--
1.7.1
More information about the linux-arm-kernel
mailing list