diff options
Diffstat (limited to 'drivers/of/base.c')
| -rw-r--r-- | drivers/of/base.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c index cf89ee6253f..2ce58be314a 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -870,3 +870,74 @@ int prom_update_property(struct device_node *np, return 0; } + +#if defined(CONFIG_OF_DYNAMIC) +/* + * Support for dynamic device trees. + * + * On some platforms, the device tree can be manipulated at runtime. + * The routines in this section support adding, removing and changing + * device tree nodes. + */ + +/** + * of_attach_node - Plug a device node into the tree and global list. + */ +void of_attach_node(struct device_node *np) +{ + unsigned long flags; + + write_lock_irqsave(&devtree_lock, flags); + np->sibling = np->parent->child; + np->allnext = allnodes; + np->parent->child = np; + allnodes = np; + write_unlock_irqrestore(&devtree_lock, flags); +} + +/** + * of_detach_node - "Unplug" a node from the device tree. + * + * The caller must hold a reference to the node. The memory associated with + * the node is not freed until its refcount goes to zero. + */ +void of_detach_node(struct device_node *np) +{ + struct device_node *parent; + unsigned long flags; + + write_lock_irqsave(&devtree_lock, flags); + + parent = np->parent; + if (!parent) + goto out_unlock; + + if (allnodes == np) + allnodes = np->allnext; + else { + struct device_node *prev; + for (prev = allnodes; + prev->allnext != np; + prev = prev->allnext) + ; + prev->allnext = np->allnext; + } + + if (parent->child == np) + parent->child = np->sibling; + else { + struct device_node *prevsib; + for (prevsib = np->parent->child; + prevsib->sibling != np; + prevsib = prevsib->sibling) + ; + prevsib->sibling = np->sibling; + } + + of_node_set_flag(np, OF_DETACHED); + +out_unlock: + write_unlock_irqrestore(&devtree_lock, flags); +} +#endif /* defined(CONFIG_OF_DYNAMIC) */ + |