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/*
* Copyright 2013 Google Inc.
* Copyright 2018-present Facebook, Inc.
*
* Taken from depthcharge: src/base/device_tree.h
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but without any warranty; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef __DEVICE_TREE_H__
#define __DEVICE_TREE_H__
#include <stdint.h>
#include <list.h>
/*
* Flattened device tree structures/constants.
*/
struct fdt_header {
uint32_t magic;
uint32_t totalsize;
uint32_t structure_offset;
uint32_t strings_offset;
uint32_t reserve_map_offset;
uint32_t version;
uint32_t last_comp_version;
uint32_t boot_cpuid_phys;
uint32_t strings_size;
uint32_t structure_size;
};
#define FDT_HEADER_MAGIC 0xd00dfeed
#define FDT_SUPPORTED_VERSION 17
#define FDT_TOKEN_BEGIN_NODE 1
#define FDT_TOKEN_END_NODE 2
#define FDT_TOKEN_PROPERTY 3
#define FDT_TOKEN_END 9
#define FDT_PHANDLE_ILLEGAL 0xdeadbeef
struct fdt_property
{
const char *name;
void *data;
uint32_t size;
};
/*
* Unflattened device tree structures.
*/
struct device_tree_property
{
struct fdt_property prop;
struct list_node list_node;
};
struct device_tree_node
{
const char *name;
uint32_t phandle;
// List of struct device_tree_property-s.
struct list_node properties;
// List of struct device_tree_nodes.
struct list_node children;
struct list_node list_node;
};
struct device_tree_reserve_map_entry
{
uint64_t start;
uint64_t size;
struct list_node list_node;
};
struct device_tree
{
const void *header;
uint32_t header_size;
uint32_t max_phandle;
struct list_node reserve_map;
struct device_tree_node *root;
};
/*
* Flattened device tree functions. These generally return the number of bytes
* which were consumed reading the requested value.
*/
// Read the property, if any, at offset offset.
int fdt_next_property(const void *blob, uint32_t offset,
struct fdt_property *prop);
// Read the name of the node, if any, at offset offset.
int fdt_node_name(const void *blob, uint32_t offset, const char **name);
void fdt_print_node(const void *blob, uint32_t offset);
int fdt_skip_node(const void *blob, uint32_t offset);
// Read a flattened device tree into a heirarchical structure which refers to
// the contents of the flattened tree in place. Modifying the flat tree
// invalidates the unflattened one.
struct device_tree *fdt_unflatten(const void *blob);
/*
* Unflattened device tree functions.
*/
// Figure out how big a device tree would be if it were flattened.
uint32_t dt_flat_size(const struct device_tree *tree);
// Flatten a device tree into the buffer pointed to by dest.
void dt_flatten(const struct device_tree *tree, void *dest);
void dt_print_node(const struct device_tree_node *node);
// Read #address-cells and #size-cells properties from a node.
void dt_read_cell_props(const struct device_tree_node *node, u32 *addrcp,
u32 *sizecp);
// Look up or create a node relative to a parent node, through its path
// represented as an array of strings.
struct device_tree_node *dt_find_node(struct device_tree_node *parent, const char **path,
u32 *addrcp, u32 *sizecp, int create);
struct device_tree_node *dt_find_node_by_phandle(struct device_tree_node *root,
uint32_t phandle);
// Look up or create a node in the tree, through its path
// represented as a string of '/' separated node names.
struct device_tree_node *dt_find_node_by_path(struct device_tree *tree,
const char *path, u32 *addrcp, u32 *sizecp, int create);
// Look up a node through an alias.
struct device_tree_node *dt_find_node_by_alias(struct device_tree *tree,
const char *alias);
// Look up a node relative to a parent node, through its compatible string.
struct device_tree_node *dt_find_compat(struct device_tree_node *parent, const char *compatible);
// Look up the next child of a parent node, through its compatible string. It
// uses child pointer as the marker to find next.
struct device_tree_node *dt_find_next_compat_child(struct device_tree_node *parent,
struct device_tree_node *child,
const char *compat);
// Look up a node relative to a parent node, through its property value.
struct device_tree_node *dt_find_prop_value(struct device_tree_node *parent, const char *name,
void *data, size_t size);
// Write src into *dest as a 'length'-byte big-endian integer.
void dt_write_int(u8 *dest, u64 src, size_t length);
// Delete a property
void dt_delete_prop(struct device_tree_node *node, const char *name);
// Add different kinds of properties to a node, or update existing ones.
void dt_add_bin_prop(struct device_tree_node *node, const char *name,
void *data, size_t size);
void dt_add_string_prop(struct device_tree_node *node, const char *name,
const char *str);
void dt_add_u32_prop(struct device_tree_node *node, const char *name, u32 val);
void dt_add_u64_prop(struct device_tree_node *node, const char *name, u64 val);
void dt_add_reg_prop(struct device_tree_node *node, u64 *addrs, u64 *sizes,
int count, u32 addr_cells, u32 size_cells);
int dt_set_bin_prop_by_path(struct device_tree *tree, const char *path,
void *data, size_t size, int create);
void dt_find_bin_prop(const struct device_tree_node *node, const char *name,
const void **data, size_t *size);
const char *dt_find_string_prop(const struct device_tree_node *node,
const char *name);
/* Apply an overlay to a base device tree. Ownership of the overlay data passes
to the newly combined base tree -- do not free() or access it afterwards! */
int dt_apply_overlay(struct device_tree *tree, struct device_tree *overlay);
/*
* Fixups to apply to a kernel's device tree before booting it.
*/
struct device_tree_fixup
{
/**
* The function which does the fixing.
* 0 on success, non-zero on error.
*/
int (*fixup)(struct device_tree_fixup *fixup,
struct device_tree *tree);
struct list_node list_node;
};
extern struct list_node device_tree_fixups;
/**
* Function to apply fixups.
* 0 on success, non-zero on error.
*/
int dt_apply_fixups(struct device_tree *tree);
/*
* Init/retrieve the /reserved-memory/ node.
*/
struct device_tree_node *dt_init_reserved_memory_node(struct device_tree *tree);
#endif /* __DEVICE_TREE_H__ */
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