2 * Copyright 2010 Benjamin Herrenschmidt, IBM Corp
3 * <benh@kernel.crashing.org>
4 * and David Gibson, IBM Corporation.
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.
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.
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
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>
29 const struct scom_controller *scom_controller;
30 EXPORT_SYMBOL_GPL(scom_controller);
32 struct device_node *scom_find_parent(struct device_node *node)
34 struct device_node *par, *tmp;
37 for (par = of_node_get(node); par;) {
38 if (of_get_property(par, "scom-controller", NULL))
40 p = of_get_property(par, "scom-parent", NULL);
43 par = of_get_parent(par);
45 par = of_find_node_by_phandle(*p);
50 EXPORT_SYMBOL_GPL(scom_find_parent);
52 scom_map_t scom_map_device(struct device_node *dev, int index)
54 struct device_node *parent;
55 unsigned int cells, size;
56 const __be32 *prop, *sprop;
60 parent = scom_find_parent(dev);
66 * We support "scom-reg" properties for adding scom registers
67 * to a random device-tree node with an explicit scom-parent
69 * We also support the simple "reg" property if the device is
70 * a direct child of a scom controller.
72 * In case both exist, "scom-reg" takes precedence.
74 prop = of_get_property(dev, "scom-reg", &size);
75 sprop = of_get_property(parent, "#scom-cells", NULL);
76 if (!prop && parent == dev->parent) {
77 prop = of_get_property(dev, "reg", &size);
78 sprop = of_get_property(parent, "#address-cells", NULL);
82 cells = sprop ? be32_to_cpup(sprop) : 1;
85 if (index >= (size / (2*cells)))
88 reg = of_read_number(&prop[index * cells * 2], cells);
89 cnt = of_read_number(&prop[index * cells * 2 + cells], cells);
91 ret = scom_map(parent, reg, cnt);
96 EXPORT_SYMBOL_GPL(scom_map_device);
98 #ifdef CONFIG_SCOM_DEBUGFS
99 struct scom_debug_entry {
100 struct device_node *dn;
105 struct debugfs_blob_wrapper blob;
108 static int scom_addr_set(void *data, u64 val)
110 struct scom_debug_entry *ent = data;
113 scom_unmap(ent->map);
115 ent->map = scom_map(ent->dn, val, 1);
116 if (scom_map_ok(ent->map))
124 static int scom_addr_get(void *data, u64 *val)
126 struct scom_debug_entry *ent = data;
130 DEFINE_SIMPLE_ATTRIBUTE(scom_addr_fops, scom_addr_get, scom_addr_set,
133 static int scom_val_set(void *data, u64 val)
135 struct scom_debug_entry *ent = data;
137 if (!scom_map_ok(ent->map))
140 scom_write(ent->map, 0, val);
145 static int scom_val_get(void *data, u64 *val)
147 struct scom_debug_entry *ent = data;
149 if (!scom_map_ok(ent->map))
152 return scom_read(ent->map, 0, val);
154 DEFINE_SIMPLE_ATTRIBUTE(scom_val_fops, scom_val_get, scom_val_set,
157 static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
160 struct scom_debug_entry *ent;
163 ent = kzalloc(sizeof(*ent), GFP_KERNEL);
167 ent->dn = of_node_get(dn);
168 ent->map = SCOM_MAP_INVALID;
169 spin_lock_init(&ent->lock);
170 snprintf(ent->name, 8, "scom%d", i);
171 ent->blob.data = (void*) dn->full_name;
172 ent->blob.size = strlen(dn->full_name);
174 dir = debugfs_create_dir(ent->name, root);
181 debugfs_create_file("addr", 0600, dir, ent, &scom_addr_fops);
182 debugfs_create_file("value", 0600, dir, ent, &scom_val_fops);
183 debugfs_create_blob("devspec", 0400, dir, &ent->blob);
188 static int scom_debug_init(void)
190 struct device_node *dn;
194 root = debugfs_create_dir("scom", powerpc_debugfs_root);
199 for_each_node_with_property(dn, "scom-controller") {
200 int id = of_get_ibm_chip_id(dn);
203 rc |= scom_debug_init_one(root, dn, id);
209 device_initcall(scom_debug_init);
210 #endif /* CONFIG_SCOM_DEBUGFS */