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 <asm/prom.h>
25#include <asm/scom.h>
26
27const struct scom_controller *scom_controller;
28EXPORT_SYMBOL_GPL(scom_controller);
29
30struct device_node *scom_find_parent(struct device_node *node)
31{
32 struct device_node *par, *tmp;
33 const u32 *p;
34
35 for (par = of_node_get(node); par;) {
36 if (of_get_property(par, "scom-controller", NULL))
37 break;
38 p = of_get_property(par, "scom-parent", NULL);
39 tmp = par;
40 if (p == NULL)
41 par = of_get_parent(par);
42 else
43 par = of_find_node_by_phandle(*p);
44 of_node_put(tmp);
45 }
46 return par;
47}
48EXPORT_SYMBOL_GPL(scom_find_parent);
49
50scom_map_t scom_map_device(struct device_node *dev, int index)
51{
52 struct device_node *parent;
53 unsigned int cells, size;
54 const u32 *prop;
55 u64 reg, cnt;
56 scom_map_t ret;
57
58 parent = scom_find_parent(dev);
59
60 if (parent == NULL)
61 return 0;
62
63 prop = of_get_property(parent, "#scom-cells", NULL);
64 cells = prop ? *prop : 1;
65
66 prop = of_get_property(dev, "scom-reg", &size);
67 if (!prop)
68 return 0;
69 size >>= 2;
70
71 if (index >= (size / (2*cells)))
72 return 0;
73
74 reg = of_read_number(&prop[index * cells * 2], cells);
75 cnt = of_read_number(&prop[index * cells * 2 + cells], cells);
76
77 ret = scom_map(parent, reg, cnt);
78 of_node_put(parent);
79
80 return ret;
81}
82EXPORT_SYMBOL_GPL(scom_map_device);
83
84#ifdef CONFIG_SCOM_DEBUGFS
85struct scom_debug_entry {
86 struct device_node *dn;
87 unsigned long addr;
88 scom_map_t map;
89 spinlock_t lock;
90 char name[8];
91 struct debugfs_blob_wrapper blob;
92};
93
94static int scom_addr_set(void *data, u64 val)
95{
96 struct scom_debug_entry *ent = data;
97
98 ent->addr = 0;
99 scom_unmap(ent->map);
100
101 ent->map = scom_map(ent->dn, val, 1);
102 if (scom_map_ok(ent->map))
103 ent->addr = val;
104 else
105 return -EFAULT;
106
107 return 0;
108}
109
110static int scom_addr_get(void *data, u64 *val)
111{
112 struct scom_debug_entry *ent = data;
113 *val = ent->addr;
114 return 0;
115}
116DEFINE_SIMPLE_ATTRIBUTE(scom_addr_fops, scom_addr_get, scom_addr_set,
117 "0x%llx\n");
118
119static int scom_val_set(void *data, u64 val)
120{
121 struct scom_debug_entry *ent = data;
122
123 if (!scom_map_ok(ent->map))
124 return -EFAULT;
125
126 scom_write(ent->map, 0, val);
127
128 return 0;
129}
130
131static int scom_val_get(void *data, u64 *val)
132{
133 struct scom_debug_entry *ent = data;
134
135 if (!scom_map_ok(ent->map))
136 return -EFAULT;
137
138 *val = scom_read(ent->map, 0);
139 return 0;
140}
141DEFINE_SIMPLE_ATTRIBUTE(scom_val_fops, scom_val_get, scom_val_set,
142 "0x%llx\n");
143
144static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
145 int i)
146{
147 struct scom_debug_entry *ent;
148 struct dentry *dir;
149
150 ent = kzalloc(sizeof(*ent), GFP_KERNEL);
151 if (!ent)
152 return -ENOMEM;
153
154 ent->dn = of_node_get(dn);
155 ent->map = SCOM_MAP_INVALID;
156 spin_lock_init(&ent->lock);
157 snprintf(ent->name, 8, "scom%d", i);
158 ent->blob.data = dn->full_name;
159 ent->blob.size = strlen(dn->full_name);
160
161 dir = debugfs_create_dir(ent->name, root);
162 if (!dir) {
163 of_node_put(dn);
164 kfree(ent);
165 return -1;
166 }
167
168 debugfs_create_file("addr", 0600, dir, ent, &scom_addr_fops);
169 debugfs_create_file("value", 0600, dir, ent, &scom_val_fops);
170 debugfs_create_blob("path", 0400, dir, &ent->blob);
171
172 return 0;
173}
174
175static int scom_debug_init(void)
176{
177 struct device_node *dn;
178 struct dentry *root;
179 int i, rc;
180
181 root = debugfs_create_dir("scom", powerpc_debugfs_root);
182 if (!root)
183 return -1;
184
185 i = rc = 0;
186 for_each_node_with_property(dn, "scom-controller")
187 rc |= scom_debug_init_one(root, dn, i++);
188
189 return rc;
190}
191device_initcall(scom_debug_init);
192#endif /* CONFIG_SCOM_DEBUGFS */