1 /* SPDX-License-Identifier: GPL-2.0+ */
2 /*
3 * Copyright (c) 2017 Google, Inc
4 * Written by Simon Glass <sjg@chromium.org>
5 */
6
7 #ifndef _DM_OF_H
8 #define _DM_OF_H
9
10 #include <asm/u-boot.h>
11 #include <asm/global_data.h>
12
13 /* integer value within a device tree property which references another node */
14 typedef u32 phandle;
15
16 /**
17 * struct property: Device tree property
18 *
19 * @name: Property name
20 * @length: Length of property in bytes
21 * @value: Pointer to property value
22 * @next: Pointer to next property, or NULL if none
23 */
24 struct property {
25 char *name;
26 int length;
27 void *value;
28 struct property *next;
29 };
30
31 /**
32 * struct device_node: Device tree node
33 *
34 * The top of this tree is typically gd->of_root which points to the root node.
35 *
36 * The head of the list of children for the root node (and any other node) is
37 * in @child, with @sibling providing a link to the next child.
38 *
39 * Each child has a pointer to its parent in @parent.
40 *
41 * A node may have properties in which case the head of the list of properties
42 * @properties pointers to the first one, with struct property->@next pointing
43 * to the next one.
44 *
45 * @name: Node name, "" for the root node
46 * @type: Node type (value of device_type property) or "<NULL>" if none
47 * @phandle: Phandle value of this none, or 0 if none
48 * @full_name: Full path to node, e.g. "/bus@1/spi@1100" ("/" for the root node)
49 * @properties: Pointer to head of list of properties, or NULL if none
50 * @parent: Pointer to parent node, or NULL if this is the root node
51 * @child: Pointer to head of child node list, or NULL if no children
52 * @sibling: Pointer to the next sibling node, or NULL if this is the last
53 */
54 struct device_node {
55 const char *name;
56 const char *type;
57 phandle phandle;
58 const char *full_name;
59
60 struct property *properties;
61 struct device_node *parent;
62 struct device_node *child;
63 struct device_node *sibling;
64 };
65
66 #define OF_MAX_PHANDLE_ARGS 16
67
68 /**
69 * struct of_phandle_args - structure to hold phandle and arguments
70 *
71 * This is used when decoding a phandle in a device tree property. Typically
72 * these look like this::
73 *
74 * wibble {
75 * phandle = <5>;
76 * };
77 * ...
78 * some-prop = <&wibble 1 2 3>
79 *
80 * Here &node is the phandle of the node 'wibble', i.e. 5. There are three
81 * arguments: 1, 2, 3.
82 *
83 * So when decoding the phandle in some-prop, np will point to wibble,
84 * args_count will be 3 and the three arguments will be in args.
85 *
86 * @np: Node that the phandle refers to
87 * @args_count: Number of arguments
88 * @args: Argument values
89 */
90 struct of_phandle_args {
91 struct device_node *np;
92 int args_count;
93 uint32_t args[OF_MAX_PHANDLE_ARGS];
94 };
95
96 DECLARE_GLOBAL_DATA_PTR;
97
98 /**
99 * of_live_active() - check if livetree is active
100 *
101 * @returns true if livetree is active, false it not
102 */
of_live_active(void)103 static inline bool of_live_active(void)
104 {
105 return gd_of_root() != NULL;
106 }
107
108 #define OF_BAD_ADDR ((u64)-1)
109
of_node_full_name(const struct device_node * np)110 static inline const char *of_node_full_name(const struct device_node *np)
111 {
112 return np ? np->full_name : "<no-node>";
113 }
114
115 /* Default #address and #size cells */
116 #if !defined(OF_ROOT_NODE_ADDR_CELLS_DEFAULT)
117 #define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
118 #define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1
119 #endif
120
121 /* Default string compare functions */
122 #if !defined(of_compat_cmp)
123 #define of_compat_cmp(s1, s2, l) strcasecmp((s1), (s2))
124 #define of_prop_cmp(s1, s2) strcmp((s1), (s2))
125 #define of_node_cmp(s1, s2) strcasecmp((s1), (s2))
126 #endif
127
128 /* Helper to read a big number; size is in cells (not bytes) */
of_read_number(const __be32 * cell,int size)129 static inline u64 of_read_number(const __be32 *cell, int size)
130 {
131 u64 r = 0;
132 while (size--)
133 r = (r << 32) | be32_to_cpu(*(cell++));
134 return r;
135 }
136
137 /* Like of_read_number, but we want an unsigned long result */
of_read_ulong(const __be32 * cell,int size)138 static inline unsigned long of_read_ulong(const __be32 *cell, int size)
139 {
140 /* toss away upper bits if unsigned long is smaller than u64 */
141 return of_read_number(cell, size);
142 }
143
144 #endif
145