1 /*
2 * Copyright (c) 2018-2024, Arm Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 /* Helper functions to offer easier navigation of Device Tree Blob */
8
9 #ifndef FDT_WRAPPERS_H
10 #define FDT_WRAPPERS_H
11
12 #include <libfdt_env.h>
13 #include <libfdt.h>
14
15 /* Number of cells, given total length in bytes. Each cell is 4 bytes long */
16 #define NCELLS(len) ((len) / 4U)
17
18 int fdt_read_uint32(const void *dtb, int node, const char *prop_name,
19 uint32_t *value);
20 uint32_t fdt_read_uint32_default(const void *dtb, int node,
21 const char *prop_name, uint32_t dflt_value);
22 int fdt_read_uint64(const void *dtb, int node, const char *prop_name,
23 uint64_t *value);
24 uint64_t fdt_read_uint64_default(const void *dtb, int node,
25 const char *prop_name, uint64_t dflt_value);
26 int fdt_read_uint32_array(const void *dtb, int node, const char *prop_name,
27 unsigned int cells, uint32_t *value);
28 int fdtw_read_string(const void *dtb, int node, const char *prop,
29 char *str, size_t size);
30 int fdtw_read_uuid(const void *dtb, int node, const char *prop,
31 unsigned int length, uint8_t *uuid);
32 int fdtw_write_inplace_cells(void *dtb, int node, const char *prop,
33 unsigned int cells, void *value);
34 int fdtw_read_bytes(const void *dtb, int node, const char *prop,
35 unsigned int length, void *value);
36 int fdtw_write_inplace_bytes(void *dtb, int node, const char *prop,
37 unsigned int length, const void *data);
38 int fdt_get_reg_props_by_index(const void *dtb, int node, int index,
39 uintptr_t *base, size_t *size);
40 int fdt_get_reg_props_by_name(const void *dtb, int node, const char *name,
41 uintptr_t *base, size_t *size);
42 int fdt_get_stdout_node_offset(const void *dtb);
43
44 uint64_t fdtw_translate_address(const void *dtb, int bus_node,
45 uint64_t base_address);
46
47 int fdtw_for_each_cpu(const void *fdt,
48 int (*callback)(const void *dtb, int node, uintptr_t mpidr));
49
50 int fdtw_find_or_add_subnode(void *fdt, int parentoffset, const char *name);
51
52 uint64_t fdt_read_prop_cells(const fdt32_t *prop, int nr_cells);
53
fdt_blob_size(const void * dtb)54 static inline uint32_t fdt_blob_size(const void *dtb)
55 {
56 const uint32_t *dtb_header = (const uint32_t *)dtb;
57
58 return fdt32_to_cpu(dtb_header[1]);
59 }
60
fdt_node_is_enabled(const void * fdt,int node)61 static inline bool fdt_node_is_enabled(const void *fdt, int node)
62 {
63 int len;
64 const void *prop = fdt_getprop(fdt, node, "status", &len);
65
66 /* A non-existing status property means the device is enabled. */
67 return (prop == NULL) || (len == 5 && strcmp((const char *)prop,
68 "okay") == 0);
69 }
70
71 #define fdt_for_each_compatible_node(dtb, node, compatible_str) \
72 for (node = fdt_node_offset_by_compatible(dtb, -1, compatible_str); \
73 node >= 0; \
74 node = fdt_node_offset_by_compatible(dtb, node, compatible_str))
75
76 #endif /* FDT_WRAPPERS_H */
77