Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Copyright 2010 Benjamin Herrenschmidt, IBM Corp
3 * <benh@kernel.crashing.org>
4 * and David Gibson, IBM Corporation.
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 as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
14 * the GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 */
20
21#include <linux/kernel.h>
22#include <linux/debugfs.h>
23#include <linux/slab.h>
24#include <linux/export.h>
25#include <asm/debug.h>
26#include <asm/prom.h>
27#include <asm/scom.h>
28
29const struct scom_controller *scom_controller;
30EXPORT_SYMBOL_GPL(scom_controller);
31
32struct device_node *scom_find_parent(struct device_node *node)
33{
34 struct device_node *par, *tmp;
35 const u32 *p;
36
37 for (par = of_node_get(node); par;) {
38 if (of_get_property(par, "scom-controller", NULL))
39 break;
40 p = of_get_property(par, "scom-parent", NULL);
41 tmp = par;
42 if (p == NULL)
43 par = of_get_parent(par);
44 else
45 par = of_find_node_by_phandle(*p);
46 of_node_put(tmp);
47 }
48 return par;
49}
50EXPORT_SYMBOL_GPL(scom_find_parent);
51
52scom_map_t scom_map_device(struct device_node *dev, int index)
53{
54 struct device_node *parent;
55 unsigned int cells, size;
56 const u32 *prop;
57 u64 reg, cnt;
58 scom_map_t ret;
59
60 parent = scom_find_parent(dev);
61
62 if (parent == NULL)
63 return 0;
64
65 prop = of_get_property(parent, "#scom-cells", NULL);
66 cells = prop ? *prop : 1;
67
68 prop = of_get_property(dev, "scom-reg", &size);
69 if (!prop)
70 return 0;
71 size >>= 2;
72
73 if (index >= (size / (2*cells)))
74 return 0;
75
76 reg = of_read_number(&prop[index * cells * 2], cells);
77 cnt = of_read_number(&prop[index * cells * 2 + cells], cells);
78
79 ret = scom_map(parent, reg, cnt);
80 of_node_put(parent);
81
82 return ret;
83}
84EXPORT_SYMBOL_GPL(scom_map_device);
85
86#ifdef CONFIG_SCOM_DEBUGFS
87struct scom_debug_entry {
88 struct device_node *dn;
89 unsigned long addr;
90 scom_map_t map;
91 spinlock_t lock;
92 char name[8];
93 struct debugfs_blob_wrapper blob;
94};
95
96static int scom_addr_set(void *data, u64 val)
97{
98 struct scom_debug_entry *ent = data;
99
100 ent->addr = 0;
101 scom_unmap(ent->map);
102
103 ent->map = scom_map(ent->dn, val, 1);
104 if (scom_map_ok(ent->map))
105 ent->addr = val;
106 else
107 return -EFAULT;
108
109 return 0;
110}
111
112static int scom_addr_get(void *data, u64 *val)
113{
114 struct scom_debug_entry *ent = data;
115 *val = ent->addr;
116 return 0;
117}
118DEFINE_SIMPLE_ATTRIBUTE(scom_addr_fops, scom_addr_get, scom_addr_set,
119 "0x%llx\n");
120
121static int scom_val_set(void *data, u64 val)
122{
123 struct scom_debug_entry *ent = data;
124
125 if (!scom_map_ok(ent->map))
126 return -EFAULT;
127
128 scom_write(ent->map, 0, val);
129
130 return 0;
131}
132
133static int scom_val_get(void *data, u64 *val)
134{
135 struct scom_debug_entry *ent = data;
136
137 if (!scom_map_ok(ent->map))
138 return -EFAULT;
139
140 *val = scom_read(ent->map, 0);
141 return 0;
142}
143DEFINE_SIMPLE_ATTRIBUTE(scom_val_fops, scom_val_get, scom_val_set,
144 "0x%llx\n");
145
146static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
147 int i)
148{
149 struct scom_debug_entry *ent;
150 struct dentry *dir;
151
152 ent = kzalloc(sizeof(*ent), GFP_KERNEL);
153 if (!ent)
154 return -ENOMEM;
155
156 ent->dn = of_node_get(dn);
157 ent->map = SCOM_MAP_INVALID;
158 spin_lock_init(&ent->lock);
159 snprintf(ent->name, 8, "scom%d", i);
160 ent->blob.data = (void*) dn->full_name;
161 ent->blob.size = strlen(dn->full_name);
162
163 dir = debugfs_create_dir(ent->name, root);
164 if (!dir) {
165 of_node_put(dn);
166 kfree(ent);
167 return -1;
168 }
169
170 debugfs_create_file("addr", 0600, dir, ent, &scom_addr_fops);
171 debugfs_create_file("value", 0600, dir, ent, &scom_val_fops);
172 debugfs_create_blob("path", 0400, dir, &ent->blob);
173
174 return 0;
175}
176
177static int scom_debug_init(void)
178{
179 struct device_node *dn;
180 struct dentry *root;
181 int i, rc;
182
183 root = debugfs_create_dir("scom", powerpc_debugfs_root);
184 if (!root)
185 return -1;
186
187 i = rc = 0;
188 for_each_node_with_property(dn, "scom-controller")
189 rc |= scom_debug_init_one(root, dn, i++);
190
191 return rc;
192}
193device_initcall(scom_debug_init);
194#endif /* CONFIG_SCOM_DEBUGFS */