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/prom.h>
26 #include <asm/scom.h>
27
28 const struct scom_controller *scom_controller;
29 EXPORT_SYMBOL_GPL(scom_controller);
30
scom_find_parent(struct device_node * node)31 struct device_node *scom_find_parent(struct device_node *node)
32 {
33 struct device_node *par, *tmp;
34 const u32 *p;
35
36 for (par = of_node_get(node); par;) {
37 if (of_get_property(par, "scom-controller", NULL))
38 break;
39 p = of_get_property(par, "scom-parent", NULL);
40 tmp = par;
41 if (p == NULL)
42 par = of_get_parent(par);
43 else
44 par = of_find_node_by_phandle(*p);
45 of_node_put(tmp);
46 }
47 return par;
48 }
49 EXPORT_SYMBOL_GPL(scom_find_parent);
50
scom_map_device(struct device_node * dev,int index)51 scom_map_t scom_map_device(struct device_node *dev, int index)
52 {
53 struct device_node *parent;
54 unsigned int cells, size;
55 const u32 *prop;
56 u64 reg, cnt;
57 scom_map_t ret;
58
59 parent = scom_find_parent(dev);
60
61 if (parent == NULL)
62 return 0;
63
64 prop = of_get_property(parent, "#scom-cells", NULL);
65 cells = prop ? *prop : 1;
66
67 prop = of_get_property(dev, "scom-reg", &size);
68 if (!prop)
69 return 0;
70 size >>= 2;
71
72 if (index >= (size / (2*cells)))
73 return 0;
74
75 reg = of_read_number(&prop[index * cells * 2], cells);
76 cnt = of_read_number(&prop[index * cells * 2 + cells], cells);
77
78 ret = scom_map(parent, reg, cnt);
79 of_node_put(parent);
80
81 return ret;
82 }
83 EXPORT_SYMBOL_GPL(scom_map_device);
84
85 #ifdef CONFIG_SCOM_DEBUGFS
86 struct scom_debug_entry {
87 struct device_node *dn;
88 unsigned long addr;
89 scom_map_t map;
90 spinlock_t lock;
91 char name[8];
92 struct debugfs_blob_wrapper blob;
93 };
94
scom_addr_set(void * data,u64 val)95 static int scom_addr_set(void *data, u64 val)
96 {
97 struct scom_debug_entry *ent = data;
98
99 ent->addr = 0;
100 scom_unmap(ent->map);
101
102 ent->map = scom_map(ent->dn, val, 1);
103 if (scom_map_ok(ent->map))
104 ent->addr = val;
105 else
106 return -EFAULT;
107
108 return 0;
109 }
110
scom_addr_get(void * data,u64 * val)111 static int scom_addr_get(void *data, u64 *val)
112 {
113 struct scom_debug_entry *ent = data;
114 *val = ent->addr;
115 return 0;
116 }
117 DEFINE_SIMPLE_ATTRIBUTE(scom_addr_fops, scom_addr_get, scom_addr_set,
118 "0x%llx\n");
119
scom_val_set(void * data,u64 val)120 static int scom_val_set(void *data, u64 val)
121 {
122 struct scom_debug_entry *ent = data;
123
124 if (!scom_map_ok(ent->map))
125 return -EFAULT;
126
127 scom_write(ent->map, 0, val);
128
129 return 0;
130 }
131
scom_val_get(void * data,u64 * val)132 static int scom_val_get(void *data, u64 *val)
133 {
134 struct scom_debug_entry *ent = data;
135
136 if (!scom_map_ok(ent->map))
137 return -EFAULT;
138
139 *val = scom_read(ent->map, 0);
140 return 0;
141 }
142 DEFINE_SIMPLE_ATTRIBUTE(scom_val_fops, scom_val_get, scom_val_set,
143 "0x%llx\n");
144
scom_debug_init_one(struct dentry * root,struct device_node * dn,int i)145 static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
146 int i)
147 {
148 struct scom_debug_entry *ent;
149 struct dentry *dir;
150
151 ent = kzalloc(sizeof(*ent), GFP_KERNEL);
152 if (!ent)
153 return -ENOMEM;
154
155 ent->dn = of_node_get(dn);
156 ent->map = SCOM_MAP_INVALID;
157 spin_lock_init(&ent->lock);
158 snprintf(ent->name, 8, "scom%d", i);
159 ent->blob.data = dn->full_name;
160 ent->blob.size = strlen(dn->full_name);
161
162 dir = debugfs_create_dir(ent->name, root);
163 if (!dir) {
164 of_node_put(dn);
165 kfree(ent);
166 return -1;
167 }
168
169 debugfs_create_file("addr", 0600, dir, ent, &scom_addr_fops);
170 debugfs_create_file("value", 0600, dir, ent, &scom_val_fops);
171 debugfs_create_blob("path", 0400, dir, &ent->blob);
172
173 return 0;
174 }
175
scom_debug_init(void)176 static int scom_debug_init(void)
177 {
178 struct device_node *dn;
179 struct dentry *root;
180 int i, rc;
181
182 root = debugfs_create_dir("scom", powerpc_debugfs_root);
183 if (!root)
184 return -1;
185
186 i = rc = 0;
187 for_each_node_with_property(dn, "scom-controller")
188 rc |= scom_debug_init_one(root, dn, i++);
189
190 return rc;
191 }
192 device_initcall(scom_debug_init);
193 #endif /* CONFIG_SCOM_DEBUGFS */
194