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-rw-r--r--arch/arm/kernel/devtree.c145
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
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1/*
2 * linux/arch/arm/kernel/devtree.c
3 *
4 * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/errno.h>
14#include <linux/types.h>
15#include <linux/bootmem.h>
16#include <linux/memblock.h>
17#include <linux/of.h>
18#include <linux/of_fdt.h>
19#include <linux/of_irq.h>
20#include <linux/of_platform.h>
21
22#include <asm/setup.h>
23#include <asm/page.h>
24#include <asm/mach/arch.h>
25#include <asm/mach-types.h>
26
27void __init early_init_dt_add_memory_arch(u64 base, u64 size)
28{
29 arm_add_memory(base, size);
30}
31
32void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
33{
34 return alloc_bootmem_align(size, align);
35}
36
37void __init arm_dt_memblock_reserve(void)
38{
39 u64 *reserve_map, base, size;
40
41 if (!initial_boot_params)
42 return;
43
44 /* Reserve the dtb region */
45 memblock_reserve(virt_to_phys(initial_boot_params),
46 be32_to_cpu(initial_boot_params->totalsize));
47
48 /*
49 * Process the reserve map. This will probably overlap the initrd
50 * and dtb locations which are already reserved, but overlaping
51 * doesn't hurt anything
52 */
53 reserve_map = ((void*)initial_boot_params) +
54 be32_to_cpu(initial_boot_params->off_mem_rsvmap);
55 while (1) {
56 base = be64_to_cpup(reserve_map++);
57 size = be64_to_cpup(reserve_map++);
58 if (!size)
59 break;
60 memblock_reserve(base, size);
61 }
62}
63
64/**
65 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
66 * @dt_phys: physical address of dt blob
67 *
68 * If a dtb was passed to the kernel in r2, then use it to choose the
69 * correct machine_desc and to setup the system.
70 */
71struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
72{
73 struct boot_param_header *devtree;
74 struct machine_desc *mdesc, *mdesc_best = NULL;
75 unsigned int score, mdesc_score = ~1;
76 unsigned long dt_root;
77 const char *model;
78
79 devtree = phys_to_virt(dt_phys);
80
81 /* check device tree validity */
82 if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
83 return NULL;
84
85 /* Search the mdescs for the 'best' compatible value match */
86 initial_boot_params = devtree;
87 dt_root = of_get_flat_dt_root();
88 for_each_machine_desc(mdesc) {
89 score = of_flat_dt_match(dt_root, mdesc->dt_compat);
90 if (score > 0 && score < mdesc_score) {
91 mdesc_best = mdesc;
92 mdesc_score = score;
93 }
94 }
95 if (!mdesc_best) {
96 const char *prop;
97 long size;
98
99 early_print("\nError: unrecognized/unsupported "
100 "device tree compatible list:\n[ ");
101
102 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
103 while (size > 0) {
104 early_print("'%s' ", prop);
105 size -= strlen(prop) + 1;
106 prop += strlen(prop) + 1;
107 }
108 early_print("]\n\n");
109
110 dump_machine_table(); /* does not return */
111 }
112
113 model = of_get_flat_dt_prop(dt_root, "model", NULL);
114 if (!model)
115 model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
116 if (!model)
117 model = "<unknown>";
118 pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);
119
120 /* Retrieve various information from the /chosen node */
121 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
122 /* Initialize {size,address}-cells info */
123 of_scan_flat_dt(early_init_dt_scan_root, NULL);
124 /* Setup memory, calling early_init_dt_add_memory_arch */
125 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
126
127 /* Change machine number to match the mdesc we're using */
128 __machine_arch_type = mdesc_best->nr;
129
130 return mdesc_best;
131}
132
133/**
134 * irq_create_of_mapping - Hook to resolve OF irq specifier into a Linux irq#
135 *
136 * Currently the mapping mechanism is trivial; simple flat hwirq numbers are
137 * mapped 1:1 onto Linux irq numbers. Cascaded irq controllers are not
138 * supported.
139 */
140unsigned int irq_create_of_mapping(struct device_node *controller,
141 const u32 *intspec, unsigned int intsize)
142{
143 return intspec[0];
144}
145EXPORT_SYMBOL_GPL(irq_create_of_mapping);