xref: /openbmc/linux/arch/mips/include/asm/machine.h (revision 8cb5d748)
1 /*
2  * Copyright (C) 2016 Imagination Technologies
3  * Author: Paul Burton <paul.burton@imgtec.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; 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__ */
95