include/linux/of_fdt.h

   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  */
  44 struct 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
  62 struct device_node;
  63
  64 /* For scanning an arbitrary device-tree at any time */
  65 extern char *of_fdt_get_string(struct boot_param_header *blob, u32 offset);
  66 extern void *of_fdt_get_property(struct boot_param_header *blob,
  67                                  unsigned long node,
  68                                  const char *name,
  69                                  unsigned long *size);
  70 extern int of_fdt_is_compatible(struct boot_param_header *blob,
  71                                 unsigned long node,
  72                                 const char *compat);
  73 extern int of_fdt_match(struct boot_param_header *blob, unsigned long node,
  74                         const char *const *compat);
  75 extern 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 */
  79 extern int __initdata dt_root_addr_cells;
  80 extern int __initdata dt_root_size_cells;
  81 extern struct boot_param_header *initial_boot_params;
  82
  83 /* For scanning the flat device-tree at boot time */
  84 extern char *find_flat_dt_string(u32 offset);
  85 extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
  86                                      int depth, void *data),
  87                            void *data);
  88 extern void *of_get_flat_dt_prop(unsigned long node, const char *name,
  89                                  unsigned long *size);
  90 extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
  91 extern int of_flat_dt_match(unsigned long node, const char *const *matches);
  92 extern unsigned long of_get_flat_dt_root(void);
  93
  94 extern int early_init_dt_scan_chosen(unsigned long node, const char *uname,
  95                                      int depth, void *data);
  96 extern void early_init_dt_check_for_initrd(unsigned long node);
  97 extern int early_init_dt_scan_memory(unsigned long node, const char *uname,
  98                                      int depth, void *data);
  99 extern void early_init_dt_add_memory_arch(u64 base, u64 size);
 100 extern void * early_init_dt_alloc_memory_arch(u64 size, u64 align);
 101 extern 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
 109 extern void early_init_dt_setup_initrd_arch(unsigned long start,
 110                                             unsigned long end);
 111 #endif
 112
 113 /* Early flat tree scan hooks */
 114 extern int early_init_dt_scan_root(unsigned long node, const char *uname,
 115                                    int depth, void *data);
 116
 117 /* Other Prototypes */
 118 extern void unflatten_device_tree(void);
 119 extern void early_init_devtree(void *);
 120 #else /* CONFIG_OF_FLATTREE */
 121 static inline void unflatten_device_tree(void) {}
 122 #endif /* CONFIG_OF_FLATTREE */
 123
 124 #endif /* __ASSEMBLY__ */
 125 #endif /* _LINUX_OF_FDT_H */