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-rw-r--r--drivers/of/base.c318
1 files changed, 312 insertions, 6 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index e6627b2320f1..cb96888d1427 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -20,8 +20,10 @@
20#include <linux/module.h> 20#include <linux/module.h>
21#include <linux/of.h> 21#include <linux/of.h>
22#include <linux/spinlock.h> 22#include <linux/spinlock.h>
23#include <linux/proc_fs.h>
23 24
24struct device_node *allnodes; 25struct device_node *allnodes;
26struct device_node *of_chosen;
25 27
26/* use when traversing tree through the allnext, child, sibling, 28/* use when traversing tree through the allnext, child, sibling,
27 * or parent members of struct device_node. 29 * or parent members of struct device_node.
@@ -37,7 +39,7 @@ int of_n_addr_cells(struct device_node *np)
37 np = np->parent; 39 np = np->parent;
38 ip = of_get_property(np, "#address-cells", NULL); 40 ip = of_get_property(np, "#address-cells", NULL);
39 if (ip) 41 if (ip)
40 return *ip; 42 return be32_to_cpup(ip);
41 } while (np->parent); 43 } while (np->parent);
42 /* No #address-cells property for the root node */ 44 /* No #address-cells property for the root node */
43 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; 45 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
@@ -53,13 +55,88 @@ int of_n_size_cells(struct device_node *np)
53 np = np->parent; 55 np = np->parent;
54 ip = of_get_property(np, "#size-cells", NULL); 56 ip = of_get_property(np, "#size-cells", NULL);
55 if (ip) 57 if (ip)
56 return *ip; 58 return be32_to_cpup(ip);
57 } while (np->parent); 59 } while (np->parent);
58 /* No #size-cells property for the root node */ 60 /* No #size-cells property for the root node */
59 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT; 61 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
60} 62}
61EXPORT_SYMBOL(of_n_size_cells); 63EXPORT_SYMBOL(of_n_size_cells);
62 64
65#if !defined(CONFIG_SPARC) /* SPARC doesn't do ref counting (yet) */
66/**
67 * of_node_get - Increment refcount of a node
68 * @node: Node to inc refcount, NULL is supported to
69 * simplify writing of callers
70 *
71 * Returns node.
72 */
73struct device_node *of_node_get(struct device_node *node)
74{
75 if (node)
76 kref_get(&node->kref);
77 return node;
78}
79EXPORT_SYMBOL(of_node_get);
80
81static inline struct device_node *kref_to_device_node(struct kref *kref)
82{
83 return container_of(kref, struct device_node, kref);
84}
85
86/**
87 * of_node_release - release a dynamically allocated node
88 * @kref: kref element of the node to be released
89 *
90 * In of_node_put() this function is passed to kref_put()
91 * as the destructor.
92 */
93static void of_node_release(struct kref *kref)
94{
95 struct device_node *node = kref_to_device_node(kref);
96 struct property *prop = node->properties;
97
98 /* We should never be releasing nodes that haven't been detached. */
99 if (!of_node_check_flag(node, OF_DETACHED)) {
100 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
101 dump_stack();
102 kref_init(&node->kref);
103 return;
104 }
105
106 if (!of_node_check_flag(node, OF_DYNAMIC))
107 return;
108
109 while (prop) {
110 struct property *next = prop->next;
111 kfree(prop->name);
112 kfree(prop->value);
113 kfree(prop);
114 prop = next;
115
116 if (!prop) {
117 prop = node->deadprops;
118 node->deadprops = NULL;
119 }
120 }
121 kfree(node->full_name);
122 kfree(node->data);
123 kfree(node);
124}
125
126/**
127 * of_node_put - Decrement refcount of a node
128 * @node: Node to dec refcount, NULL is supported to
129 * simplify writing of callers
130 *
131 */
132void of_node_put(struct device_node *node)
133{
134 if (node)
135 kref_put(&node->kref, of_node_release);
136}
137EXPORT_SYMBOL(of_node_put);
138#endif /* !CONFIG_SPARC */
139
63struct property *of_find_property(const struct device_node *np, 140struct property *of_find_property(const struct device_node *np,
64 const char *name, 141 const char *name,
65 int *lenp) 142 int *lenp)
@@ -144,6 +221,27 @@ int of_device_is_compatible(const struct device_node *device,
144EXPORT_SYMBOL(of_device_is_compatible); 221EXPORT_SYMBOL(of_device_is_compatible);
145 222
146/** 223/**
224 * of_machine_is_compatible - Test root of device tree for a given compatible value
225 * @compat: compatible string to look for in root node's compatible property.
226 *
227 * Returns true if the root node has the given value in its
228 * compatible property.
229 */
230int of_machine_is_compatible(const char *compat)
231{
232 struct device_node *root;
233 int rc = 0;
234
235 root = of_find_node_by_path("/");
236 if (root) {
237 rc = of_device_is_compatible(root, compat);
238 of_node_put(root);
239 }
240 return rc;
241}
242EXPORT_SYMBOL(of_machine_is_compatible);
243
244/**
147 * of_device_is_available - check if a device is available for use 245 * of_device_is_available - check if a device is available for use
148 * 246 *
149 * @device: Node to check for availability 247 * @device: Node to check for availability
@@ -519,6 +617,27 @@ int of_modalias_node(struct device_node *node, char *modalias, int len)
519EXPORT_SYMBOL_GPL(of_modalias_node); 617EXPORT_SYMBOL_GPL(of_modalias_node);
520 618
521/** 619/**
620 * of_find_node_by_phandle - Find a node given a phandle
621 * @handle: phandle of the node to find
622 *
623 * Returns a node pointer with refcount incremented, use
624 * of_node_put() on it when done.
625 */
626struct device_node *of_find_node_by_phandle(phandle handle)
627{
628 struct device_node *np;
629
630 read_lock(&devtree_lock);
631 for (np = allnodes; np; np = np->allnext)
632 if (np->phandle == handle)
633 break;
634 of_node_get(np);
635 read_unlock(&devtree_lock);
636 return np;
637}
638EXPORT_SYMBOL(of_find_node_by_phandle);
639
640/**
522 * of_parse_phandle - Resolve a phandle property to a device_node pointer 641 * of_parse_phandle - Resolve a phandle property to a device_node pointer
523 * @np: Pointer to device node holding phandle property 642 * @np: Pointer to device node holding phandle property
524 * @phandle_name: Name of property holding a phandle value 643 * @phandle_name: Name of property holding a phandle value
@@ -578,8 +697,8 @@ int of_parse_phandles_with_args(struct device_node *np, const char *list_name,
578 const void **out_args) 697 const void **out_args)
579{ 698{
580 int ret = -EINVAL; 699 int ret = -EINVAL;
581 const u32 *list; 700 const __be32 *list;
582 const u32 *list_end; 701 const __be32 *list_end;
583 int size; 702 int size;
584 int cur_index = 0; 703 int cur_index = 0;
585 struct device_node *node = NULL; 704 struct device_node *node = NULL;
@@ -593,7 +712,7 @@ int of_parse_phandles_with_args(struct device_node *np, const char *list_name,
593 list_end = list + size / sizeof(*list); 712 list_end = list + size / sizeof(*list);
594 713
595 while (list < list_end) { 714 while (list < list_end) {
596 const u32 *cells; 715 const __be32 *cells;
597 const phandle *phandle; 716 const phandle *phandle;
598 717
599 phandle = list++; 718 phandle = list++;
@@ -617,7 +736,7 @@ int of_parse_phandles_with_args(struct device_node *np, const char *list_name,
617 goto err1; 736 goto err1;
618 } 737 }
619 738
620 list += *cells; 739 list += be32_to_cpup(cells);
621 if (list > list_end) { 740 if (list > list_end) {
622 pr_debug("%s: insufficient arguments length\n", 741 pr_debug("%s: insufficient arguments length\n",
623 np->full_name); 742 np->full_name);
@@ -658,3 +777,190 @@ err0:
658 return ret; 777 return ret;
659} 778}
660EXPORT_SYMBOL(of_parse_phandles_with_args); 779EXPORT_SYMBOL(of_parse_phandles_with_args);
780
781/**
782 * prom_add_property - Add a property to a node
783 */
784int prom_add_property(struct device_node *np, struct property *prop)
785{
786 struct property **next;
787 unsigned long flags;
788
789 prop->next = NULL;
790 write_lock_irqsave(&devtree_lock, flags);
791 next = &np->properties;
792 while (*next) {
793 if (strcmp(prop->name, (*next)->name) == 0) {
794 /* duplicate ! don't insert it */
795 write_unlock_irqrestore(&devtree_lock, flags);
796 return -1;
797 }
798 next = &(*next)->next;
799 }
800 *next = prop;
801 write_unlock_irqrestore(&devtree_lock, flags);
802
803#ifdef CONFIG_PROC_DEVICETREE
804 /* try to add to proc as well if it was initialized */
805 if (np->pde)
806 proc_device_tree_add_prop(np->pde, prop);
807#endif /* CONFIG_PROC_DEVICETREE */
808
809 return 0;
810}
811
812/**
813 * prom_remove_property - Remove a property from a node.
814 *
815 * Note that we don't actually remove it, since we have given out
816 * who-knows-how-many pointers to the data using get-property.
817 * Instead we just move the property to the "dead properties"
818 * list, so it won't be found any more.
819 */
820int prom_remove_property(struct device_node *np, struct property *prop)
821{
822 struct property **next;
823 unsigned long flags;
824 int found = 0;
825
826 write_lock_irqsave(&devtree_lock, flags);
827 next = &np->properties;
828 while (*next) {
829 if (*next == prop) {
830 /* found the node */
831 *next = prop->next;
832 prop->next = np->deadprops;
833 np->deadprops = prop;
834 found = 1;
835 break;
836 }
837 next = &(*next)->next;
838 }
839 write_unlock_irqrestore(&devtree_lock, flags);
840
841 if (!found)
842 return -ENODEV;
843
844#ifdef CONFIG_PROC_DEVICETREE
845 /* try to remove the proc node as well */
846 if (np->pde)
847 proc_device_tree_remove_prop(np->pde, prop);
848#endif /* CONFIG_PROC_DEVICETREE */
849
850 return 0;
851}
852
853/*
854 * prom_update_property - Update a property in a node.
855 *
856 * Note that we don't actually remove it, since we have given out
857 * who-knows-how-many pointers to the data using get-property.
858 * Instead we just move the property to the "dead properties" list,
859 * and add the new property to the property list
860 */
861int prom_update_property(struct device_node *np,
862 struct property *newprop,
863 struct property *oldprop)
864{
865 struct property **next;
866 unsigned long flags;
867 int found = 0;
868
869 write_lock_irqsave(&devtree_lock, flags);
870 next = &np->properties;
871 while (*next) {
872 if (*next == oldprop) {
873 /* found the node */
874 newprop->next = oldprop->next;
875 *next = newprop;
876 oldprop->next = np->deadprops;
877 np->deadprops = oldprop;
878 found = 1;
879 break;
880 }
881 next = &(*next)->next;
882 }
883 write_unlock_irqrestore(&devtree_lock, flags);
884
885 if (!found)
886 return -ENODEV;
887
888#ifdef CONFIG_PROC_DEVICETREE
889 /* try to add to proc as well if it was initialized */
890 if (np->pde)
891 proc_device_tree_update_prop(np->pde, newprop, oldprop);
892#endif /* CONFIG_PROC_DEVICETREE */
893
894 return 0;
895}
896
897#if defined(CONFIG_OF_DYNAMIC)
898/*
899 * Support for dynamic device trees.
900 *
901 * On some platforms, the device tree can be manipulated at runtime.
902 * The routines in this section support adding, removing and changing
903 * device tree nodes.
904 */
905
906/**
907 * of_attach_node - Plug a device node into the tree and global list.
908 */
909void of_attach_node(struct device_node *np)
910{
911 unsigned long flags;
912
913 write_lock_irqsave(&devtree_lock, flags);
914 np->sibling = np->parent->child;
915 np->allnext = allnodes;
916 np->parent->child = np;
917 allnodes = np;
918 write_unlock_irqrestore(&devtree_lock, flags);
919}
920
921/**
922 * of_detach_node - "Unplug" a node from the device tree.
923 *
924 * The caller must hold a reference to the node. The memory associated with
925 * the node is not freed until its refcount goes to zero.
926 */
927void of_detach_node(struct device_node *np)
928{
929 struct device_node *parent;
930 unsigned long flags;
931
932 write_lock_irqsave(&devtree_lock, flags);
933
934 parent = np->parent;
935 if (!parent)
936 goto out_unlock;
937
938 if (allnodes == np)
939 allnodes = np->allnext;
940 else {
941 struct device_node *prev;
942 for (prev = allnodes;
943 prev->allnext != np;
944 prev = prev->allnext)
945 ;
946 prev->allnext = np->allnext;
947 }
948
949 if (parent->child == np)
950 parent->child = np->sibling;
951 else {
952 struct device_node *prevsib;
953 for (prevsib = np->parent->child;
954 prevsib->sibling != np;
955 prevsib = prevsib->sibling)
956 ;
957 prevsib->sibling = np->sibling;
958 }
959
960 of_node_set_flag(np, OF_DETACHED);
961
962out_unlock:
963 write_unlock_irqrestore(&devtree_lock, flags);
964}
965#endif /* defined(CONFIG_OF_DYNAMIC) */
966