LXR linux/include/linux/of

   1/*
   2 * Definitions for working with the Flattened Device Tree data format
   3 *
   4 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
   5 * benh@kernel.crashing.org
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public License
   9 * version 2 as published by the Free Software Foundation.
  10 */
  11
  12#ifndef _LINUX_OF_FDT_H
  13#define _LINUX_OF_FDT_H
  14
  15#include <linux/types.h>
  16#include <linux/init.h>
  17
  18/* Definitions used by the flattened device tree */
  19#define OF_DT_HEADER            0xd00dfeed      /* marker */
  20#define OF_DT_BEGIN_NODE        0x1             /* Start of node, full name */
  21#define OF_DT_END_NODE          0x2             /* End node */
  22#define OF_DT_PROP              0x3             /* Property: name off, size,
  23                                                 * content */
  24#define OF_DT_NOP               0x4             /* nop */
  25#define OF_DT_END               0x9
  26
  27#define OF_DT_VERSION           0x10
  28
  29#ifndef __ASSEMBLY__
  30/*
  31 * This is what gets passed to the kernel by prom_init or kexec
  32 *
  33 * The dt struct contains the device tree structure, full pathes and
  34 * property contents. The dt strings contain a separate block with just
  35 * the strings for the property names, and is fully page aligned and
  36 * self contained in a page, so that it can be kept around by the kernel,
  37 * each property name appears only once in this page (cheap compression)
  38 *
  39 * the mem_rsvmap contains a map of reserved ranges of physical memory,
  40 * passing it here instead of in the device-tree itself greatly simplifies
  41 * the job of everybody. It's just a list of u64 pairs (base/size) that
  42 * ends when size is 0
  43 */
  44struct boot_param_header {
  45        __be32  magic;                  /* magic word OF_DT_HEADER */
  46        __be32  totalsize;              /* total size of DT block */
  47        __be32  off_dt_struct;          /* offset to structure */
  48        __be32  off_dt_strings;         /* offset to strings */
  49        __be32  off_mem_rsvmap;         /* offset to memory reserve map */
  50        __be32  version;                /* format version */
  51        __be32  last_comp_version;      /* last compatible version */
  52        /* version 2 fields below */
  53        __be32  boot_cpuid_phys;        /* Physical CPU id we're booting on */
  54        /* version 3 fields below */
  55        __be32  dt_strings_size;        /* size of the DT strings block */
  56        /* version 17 fields below */
  57        __be32  dt_struct_size;         /* size of the DT structure block */
  58};
  59
  60#if defined(CONFIG_OF_FLATTREE)
  61
  62struct device_node;
  63
  64/* For scanning an arbitrary device-tree at any time */
  65extern char *of_fdt_get_string(struct boot_param_header *blob, u32 offset);
  66extern void *of_fdt_get_property(struct boot_param_header *blob,
  67                                 unsigned long node,
  68                                 const char *name,
  69                                 unsigned long *size);
  70extern int of_fdt_is_compatible(struct boot_param_header *blob,
  71                                unsigned long node,
  72                                const char *compat);
  73extern int of_fdt_match(struct boot_param_header *blob, unsigned long node,
  74                        const char **compat);
  75extern void of_fdt_unflatten_tree(unsigned long *blob,
  76                               struct device_node **mynodes);
  77
  78/* TBD: Temporary export of fdt globals - remove when code fully merged */
  79extern int __initdata dt_root_addr_cells;
  80extern int __initdata dt_root_size_cells;
  81extern struct boot_param_header *initial_boot_params;
  82
  83/* For scanning the flat device-tree at boot time */
  84extern char *find_flat_dt_string(u32 offset);
  85extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
  86                                     int depth, void *data),
  87                           void *data);
  88extern void *of_get_flat_dt_prop(unsigned long node, const char *name,
  89                                 unsigned long *size);
  90extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
  91extern int of_flat_dt_match(unsigned long node, const char **matches);
  92extern unsigned long of_get_flat_dt_root(void);
  93
  94extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
  95                                     int depth, void *data);
  96extern void early_init_dt_check_for_initrd(unsigned long node);
  97extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
  98                                     int depth, void *data);
  99extern void early_init_dt_add_memory_arch(u64 base, u64 size);
 100extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
 101extern u64 dt_mem_next_cell(int s, __be32 **cellp);
 102
 103/*
 104 * If BLK_DEV_INITRD, the fdt early init code will call this function,
 105 * to be provided by the arch code. start and end are specified as
 106 * physical addresses.
 107 */
 108#ifdef CONFIG_BLK_DEV_INITRD
 109extern void early_init_dt_setup_initrd_arch(unsigned long start,
 110                                            unsigned long end);
 111#endif
 112
 113/* Early flat tree scan hooks */
 114extern int early_init_dt_scan_root(unsigned long node, const char *uname,
 115                                   int depth, void *data);
 116
 117/* Other Prototypes */
 118extern void unflatten_device_tree(void);
 119extern void early_init_devtree(void *);
 120#else /* CONFIG_OF_FLATTREE */
 121static inline void unflatten_device_tree(void) {}
 122#endif /* CONFIG_OF_FLATTREE */
 123
 124#endif /* __ASSEMBLY__ */
 125#endif /* _LINUX_OF_FDT_H */
 126