xref: /openbmc/linux/arch/mips/include/asm/machine.h (revision d9fd5a71)
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__ */
91