xref: /openbmc/linux/arch/sparc/kernel/prom_common.c (revision 05bcf503)
1 /* prom_common.c: OF device tree support common code.
2  *
3  * Paul Mackerras	August 1996.
4  * Copyright (C) 1996-2005 Paul Mackerras.
5  *
6  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
7  *    {engebret|bergner}@us.ibm.com
8  *
9  *  Adapted for sparc by David S. Miller davem@davemloft.net
10  *
11  *      This program is free software; you can redistribute it and/or
12  *      modify it under the terms of the GNU General Public License
13  *      as published by the Free Software Foundation; either version
14  *      2 of the License, or (at your option) any later version.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/export.h>
19 #include <linux/errno.h>
20 #include <linux/mutex.h>
21 #include <linux/slab.h>
22 #include <linux/of.h>
23 #include <linux/of_pdt.h>
24 #include <asm/prom.h>
25 #include <asm/oplib.h>
26 
27 #include "prom.h"
28 
29 struct device_node *of_console_device;
30 EXPORT_SYMBOL(of_console_device);
31 
32 char *of_console_path;
33 EXPORT_SYMBOL(of_console_path);
34 
35 char *of_console_options;
36 EXPORT_SYMBOL(of_console_options);
37 
38 int of_getintprop_default(struct device_node *np, const char *name, int def)
39 {
40 	struct property *prop;
41 	int len;
42 
43 	prop = of_find_property(np, name, &len);
44 	if (!prop || len != 4)
45 		return def;
46 
47 	return *(int *) prop->value;
48 }
49 EXPORT_SYMBOL(of_getintprop_default);
50 
51 DEFINE_MUTEX(of_set_property_mutex);
52 EXPORT_SYMBOL(of_set_property_mutex);
53 
54 int of_set_property(struct device_node *dp, const char *name, void *val, int len)
55 {
56 	struct property **prevp;
57 	void *new_val;
58 	int err;
59 
60 	new_val = kmemdup(val, len, GFP_KERNEL);
61 	if (!new_val)
62 		return -ENOMEM;
63 
64 	err = -ENODEV;
65 
66 	mutex_lock(&of_set_property_mutex);
67 	write_lock(&devtree_lock);
68 	prevp = &dp->properties;
69 	while (*prevp) {
70 		struct property *prop = *prevp;
71 
72 		if (!strcasecmp(prop->name, name)) {
73 			void *old_val = prop->value;
74 			int ret;
75 
76 			ret = prom_setprop(dp->phandle, name, val, len);
77 
78 			err = -EINVAL;
79 			if (ret >= 0) {
80 				prop->value = new_val;
81 				prop->length = len;
82 
83 				if (OF_IS_DYNAMIC(prop))
84 					kfree(old_val);
85 
86 				OF_MARK_DYNAMIC(prop);
87 
88 				err = 0;
89 			}
90 			break;
91 		}
92 		prevp = &(*prevp)->next;
93 	}
94 	write_unlock(&devtree_lock);
95 	mutex_unlock(&of_set_property_mutex);
96 
97 	/* XXX Upate procfs if necessary... */
98 
99 	return err;
100 }
101 EXPORT_SYMBOL(of_set_property);
102 
103 int of_find_in_proplist(const char *list, const char *match, int len)
104 {
105 	while (len > 0) {
106 		int l;
107 
108 		if (!strcmp(list, match))
109 			return 1;
110 		l = strlen(list) + 1;
111 		list += l;
112 		len -= l;
113 	}
114 	return 0;
115 }
116 EXPORT_SYMBOL(of_find_in_proplist);
117 
118 /*
119  * SPARC32 and SPARC64's prom_nextprop() do things differently
120  * here, despite sharing the same interface.  SPARC32 doesn't fill in 'buf',
121  * returning NULL on an error.  SPARC64 fills in 'buf', but sets it to an
122  * empty string upon error.
123  */
124 static int __init handle_nextprop_quirks(char *buf, const char *name)
125 {
126 	if (!name || strlen(name) == 0)
127 		return -1;
128 
129 #ifdef CONFIG_SPARC32
130 	strcpy(buf, name);
131 #endif
132 	return 0;
133 }
134 
135 static int __init prom_common_nextprop(phandle node, char *prev, char *buf)
136 {
137 	const char *name;
138 
139 	buf[0] = '\0';
140 	name = prom_nextprop(node, prev, buf);
141 	return handle_nextprop_quirks(buf, name);
142 }
143 
144 unsigned int prom_early_allocated __initdata;
145 
146 static struct of_pdt_ops prom_sparc_ops __initdata = {
147 	.nextprop = prom_common_nextprop,
148 	.getproplen = prom_getproplen,
149 	.getproperty = prom_getproperty,
150 	.getchild = prom_getchild,
151 	.getsibling = prom_getsibling,
152 };
153 
154 void __init prom_build_devicetree(void)
155 {
156 	of_pdt_build_devicetree(prom_root_node, &prom_sparc_ops);
157 	of_console_init();
158 
159 	pr_info("PROM: Built device tree with %u bytes of memory.\n",
160 			prom_early_allocated);
161 }
162