of_fdt.h

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/*
 * Definitions for working with the Flattened Device Tree data format
 *
 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
 * [email protected]
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#ifndef _LINUX_OF_FDT_H
#define _LINUX_OF_FDT_H

#include <linux/types.h>
#include <linux/init.h>

/* Definitions used by the flattened device tree */
#define OF_DT_HEADER        0xd00dfeed  /* marker */
#define OF_DT_BEGIN_NODE    0x1     /* Start of node, full name */
#define OF_DT_END_NODE      0x2     /* End node */
#define OF_DT_PROP      0x3     /* Property: name off, size,
                         * content */
#define OF_DT_NOP       0x4     /* nop */
#define OF_DT_END       0x9

#define OF_DT_VERSION       0x10

#ifndef __ASSEMBLY__
/*
 * This is what gets passed to the kernel by prom_init or kexec
 *
 * The dt struct contains the device tree structure, full pathes and
 * property contents. The dt strings contain a separate block with just
 * the strings for the property names, and is fully page aligned and
 * self contained in a page, so that it can be kept around by the kernel,
 * each property name appears only once in this page (cheap compression)
 *
 * the mem_rsvmap contains a map of reserved ranges of physical memory,
 * passing it here instead of in the device-tree itself greatly simplifies
 * the job of everybody. It's just a list of u64 pairs (base/size) that
 * ends when size is 0
 */
struct boot_param_header {
    __be32  magic;          /* magic word OF_DT_HEADER */
    __be32  totalsize;      /* total size of DT block */
    __be32  off_dt_struct;      /* offset to structure */
    __be32  off_dt_strings;     /* offset to strings */
    __be32  off_mem_rsvmap;     /* offset to memory reserve map */
    __be32  version;        /* format version */
    __be32  last_comp_version;  /* last compatible version */
    /* version 2 fields below */
    __be32  boot_cpuid_phys;    /* Physical CPU id we're booting on */
    /* version 3 fields below */
    __be32  dt_strings_size;    /* size of the DT strings block */
    /* version 17 fields below */
    __be32  dt_struct_size;     /* size of the DT structure block */
};

#if defined(CONFIG_OF_FLATTREE)

struct device_node;

/* For scanning an arbitrary device-tree at any time */
extern char *of_fdt_get_string(struct boot_param_header *blob, u32 offset);
extern void *of_fdt_get_property(struct boot_param_header *blob,
                 unsigned long node,
                 const char *name,
                 unsigned long *size);
extern int of_fdt_is_compatible(struct boot_param_header *blob,
                unsigned long node,
                const char *compat);
extern int of_fdt_match(struct boot_param_header *blob, unsigned long node,
            const char *const *compat);
extern void of_fdt_unflatten_tree(unsigned long *blob,
                   struct device_node **mynodes);

/* TBD: Temporary export of fdt globals - remove when code fully merged */
extern int __initdata dt_root_addr_cells;
extern int __initdata dt_root_size_cells;
extern struct boot_param_header *initial_boot_params;

/* For scanning the flat device-tree at boot time */
extern char *find_flat_dt_string(u32 offset);
extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
                     int depth, void *data),
               void *data);
extern void *of_get_flat_dt_prop(unsigned long node, const char *name,
                 unsigned long *size);
extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
extern int of_flat_dt_match(unsigned long node, const char *const *matches);
extern unsigned long of_get_flat_dt_root(void);

extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
                     int depth, void *data);
extern void early_init_dt_check_for_initrd(unsigned long node);
extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
                     int depth, void *data);
extern void early_init_dt_add_memory_arch(u64 base, u64 size);
extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
extern u64 dt_mem_next_cell(int s, __be32 **cellp);

/*
 * If BLK_DEV_INITRD, the fdt early init code will call this function,
 * to be provided by the arch code. start and end are specified as
 * physical addresses.
 */
#ifdef CONFIG_BLK_DEV_INITRD
extern void early_init_dt_setup_initrd_arch(unsigned long start,
                        unsigned long end);
#endif

/* Early flat tree scan hooks */
extern int early_init_dt_scan_root(unsigned long node, const char *uname,
                   int depth, void *data);

/* Other Prototypes */
extern void unflatten_device_tree(void);
extern void early_init_devtree(void *);
#else /* CONFIG_OF_FLATTREE */
static inline void unflatten_device_tree(void) {}
#endif /* CONFIG_OF_FLATTREE */

#endif /* __ASSEMBLY__ */
#endif /* _LINUX_OF_FDT_H */