arch/mips/include/asm/machine.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Copyright (C) 2016 Imagination Technologies
   4  * Author: Paul Burton <paul.burton@mips.com>
   5  */
   6
   7 #ifndef __MIPS_ASM_MACHINE_H__
   8 #define __MIPS_ASM_MACHINE_H__
   9
  10 #include <linux/libfdt.h>
  11 #include <linux/of.h>
  12
  13 struct mips_machine {
  14         const struct of_device_id *matches;
  15         const void *fdt;
  16         bool (*detect)(void);
  17         const void *(*fixup_fdt)(const void *fdt, const void *match_data);
  18         unsigned int (*measure_hpt_freq)(void);
  19 };
  20
  21 extern long __mips_machines_start;
  22 extern long __mips_machines_end;
  23
  24 #define MIPS_MACHINE(name)                                              \
  25         static const struct mips_machine __mips_mach_##name             \
  26                 __used __section(.mips.machines.init)
  27
  28 #define for_each_mips_machine(mach)                                     \
  29         for ((mach) = (struct mips_machine *)&__mips_machines_start;    \
  30              (mach) < (struct mips_machine *)&__mips_machines_end;      \
  31              (mach)++)
  32
  33 /**
  34  * mips_machine_is_compatible() - check if a machine is compatible with an FDT
  35  * @mach: the machine struct to check
  36  * @fdt: the FDT to check for compatibility with
  37  *
  38  * Check whether the given machine @mach is compatible with the given flattened
  39  * device tree @fdt, based upon the compatibility property of the root node.
  40  *
  41  * Return: the device id matched if any, else NULL
  42  */
  43 static inline const struct of_device_id *
  44 mips_machine_is_compatible(const struct mips_machine *mach, const void *fdt)
  45 {
  46         const struct of_device_id *match;
  47
  48         if (!mach->matches)
  49                 return NULL;
  50
  51         for (match = mach->matches; match->compatible[0]; match++) {
  52                 if (fdt_node_check_compatible(fdt, 0, match->compatible) == 0)
  53                         return match;
  54         }
  55
  56         return NULL;
  57 }
  58
  59 /**
  60  * struct mips_fdt_fixup - Describe a fixup to apply to an FDT
  61  * @apply: applies the fixup to @fdt, returns zero on success else -errno
  62  * @description: a short description of the fixup
  63  *
  64  * Describes a fixup applied to an FDT blob by the @apply function. The
  65  * @description field provides a short description of the fixup intended for
  66  * use in error messages if the @apply function returns non-zero.
  67  */
  68 struct mips_fdt_fixup {
  69         int (*apply)(void *fdt);
  70         const char *description;
  71 };
  72
  73 /**
  74  * apply_mips_fdt_fixups() - apply fixups to an FDT blob
  75  * @fdt_out: buffer in which to place the fixed-up FDT
  76  * @fdt_out_size: the size of the @fdt_out buffer
  77  * @fdt_in: the FDT blob
  78  * @fixups: pointer to an array of fixups to be applied
  79  *
  80  * Loop through the array of fixups pointed to by @fixups, calling the apply
  81  * function on each until either one returns an error or we reach the end of
  82  * the list as indicated by an entry with a NULL apply field.
  83  *
  84  * Return: zero on success, else -errno
  85  */
  86 extern int __init apply_mips_fdt_fixups(void *fdt_out, size_t fdt_out_size,
  87                                         const void *fdt_in,
  88                                         const struct mips_fdt_fixup *fixups);
  89
  90 #endif /* __MIPS_ASM_MACHINE_H__ */