arch/mips/include/asm/machine.h

   1 /*
   2  * Copyright (C) 2016 Imagination Technologies
   3  * Author: Paul Burton <paul.burton@mips.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the
   7  * Free Software Foundation;  either version 2 of the  License, or (at your
   8  * option) any later version.
   9  */
  10
  11 #ifndef __MIPS_ASM_MACHINE_H__
  12 #define __MIPS_ASM_MACHINE_H__
  13
  14 #include <linux/libfdt.h>
  15 #include <linux/of.h>
  16
  17 struct mips_machine {
  18         const struct of_device_id *matches;
  19         const void *fdt;
  20         bool (*detect)(void);
  21         const void *(*fixup_fdt)(const void *fdt, const void *match_data);
  22         unsigned int (*measure_hpt_freq)(void);
  23 };
  24
  25 extern long __mips_machines_start;
  26 extern long __mips_machines_end;
  27
  28 #define MIPS_MACHINE(name)                                              \
  29         static const struct mips_machine __mips_mach_##name             \
  30                 __used __section(.mips.machines.init)
  31
  32 #define for_each_mips_machine(mach)                                     \
  33         for ((mach) = (struct mips_machine *)&__mips_machines_start;    \
  34              (mach) < (struct mips_machine *)&__mips_machines_end;      \
  35              (mach)++)
  36
  37 /**
  38  * mips_machine_is_compatible() - check if a machine is compatible with an FDT
  39  * @mach: the machine struct to check
  40  * @fdt: the FDT to check for compatibility with
  41  *
  42  * Check whether the given machine @mach is compatible with the given flattened
  43  * device tree @fdt, based upon the compatibility property of the root node.
  44  *
  45  * Return: the device id matched if any, else NULL
  46  */
  47 static inline const struct of_device_id *
  48 mips_machine_is_compatible(const struct mips_machine *mach, const void *fdt)
  49 {
  50         const struct of_device_id *match;
  51
  52         if (!mach->matches)
  53                 return NULL;
  54
  55         for (match = mach->matches; match->compatible[0]; match++) {
  56                 if (fdt_node_check_compatible(fdt, 0, match->compatible) == 0)
  57                         return match;
  58         }
  59
  60         return NULL;
  61 }
  62
  63 /**
  64  * struct mips_fdt_fixup - Describe a fixup to apply to an FDT
  65  * @apply: applies the fixup to @fdt, returns zero on success else -errno
  66  * @description: a short description of the fixup
  67  *
  68  * Describes a fixup applied to an FDT blob by the @apply function. The
  69  * @description field provides a short description of the fixup intended for
  70  * use in error messages if the @apply function returns non-zero.
  71  */
  72 struct mips_fdt_fixup {
  73         int (*apply)(void *fdt);
  74         const char *description;
  75 };
  76
  77 /**
  78  * apply_mips_fdt_fixups() - apply fixups to an FDT blob
  79  * @fdt_out: buffer in which to place the fixed-up FDT
  80  * @fdt_out_size: the size of the @fdt_out buffer
  81  * @fdt_in: the FDT blob
  82  * @fixups: pointer to an array of fixups to be applied
  83  *
  84  * Loop through the array of fixups pointed to by @fixups, calling the apply
  85  * function on each until either one returns an error or we reach the end of
  86  * the list as indicated by an entry with a NULL apply field.
  87  *
  88  * Return: zero on success, else -errno
  89  */
  90 extern int __init apply_mips_fdt_fixups(void *fdt_out, size_t fdt_out_size,
  91                                         const void *fdt_in,
  92                                         const struct mips_fdt_fixup *fixups);
  93
  94 #endif /* __MIPS_ASM_MACHINE_H__ */