summaryrefslogtreecommitdiff
path: root/arch/powerpc/sysdev/scom.c
blob: 0f6fd5d04d332372aa74d94caf6d17fce3402559 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
/*
 * Copyright 2010 Benjamin Herrenschmidt, IBM Corp
 *                <benh@kernel.crashing.org>
 *     and        David Gibson, IBM Corporation.
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/export.h>
#include <asm/debugfs.h>
#include <asm/prom.h>
#include <asm/scom.h>
#include <linux/uaccess.h>

const struct scom_controller *scom_controller;
EXPORT_SYMBOL_GPL(scom_controller);

struct device_node *scom_find_parent(struct device_node *node)
{
	struct device_node *par, *tmp;
	const u32 *p;

	for (par = of_node_get(node); par;) {
		if (of_get_property(par, "scom-controller", NULL))
			break;
		p = of_get_property(par, "scom-parent", NULL);
		tmp = par;
		if (p == NULL)
			par = of_get_parent(par);
		else
			par = of_find_node_by_phandle(*p);
		of_node_put(tmp);
	}
	return par;
}
EXPORT_SYMBOL_GPL(scom_find_parent);

scom_map_t scom_map_device(struct device_node *dev, int index)
{
	struct device_node *parent;
	unsigned int cells, size;
	const __be32 *prop, *sprop;
	u64 reg, cnt;
	scom_map_t ret;

	parent = scom_find_parent(dev);

	if (parent == NULL)
		return 0;

	/*
	 * We support "scom-reg" properties for adding scom registers
	 * to a random device-tree node with an explicit scom-parent
	 *
	 * We also support the simple "reg" property if the device is
	 * a direct child of a scom controller.
	 *
	 * In case both exist, "scom-reg" takes precedence.
	 */
	prop = of_get_property(dev, "scom-reg", &size);
	sprop = of_get_property(parent, "#scom-cells", NULL);
	if (!prop && parent == dev->parent) {
		prop = of_get_property(dev, "reg", &size);
		sprop = of_get_property(parent, "#address-cells", NULL);
	}
	if (!prop)
		return NULL;
	cells = sprop ? be32_to_cpup(sprop) : 1;
	size >>= 2;

	if (index >= (size / (2*cells)))
		return 0;

	reg = of_read_number(&prop[index * cells * 2], cells);
	cnt = of_read_number(&prop[index * cells * 2 + cells], cells);

	ret = scom_map(parent, reg, cnt);
	of_node_put(parent);

	return ret;
}
EXPORT_SYMBOL_GPL(scom_map_device);

#ifdef CONFIG_SCOM_DEBUGFS
struct scom_debug_entry {
	struct device_node *dn;
	struct debugfs_blob_wrapper path;
	char name[16];
};

static ssize_t scom_debug_read(struct file *filp, char __user *ubuf,
			       size_t count, loff_t *ppos)
{
	struct scom_debug_entry *ent = filp->private_data;
	u64 __user *ubuf64 = (u64 __user *)ubuf;
	loff_t off = *ppos;
	ssize_t done = 0; 
	u64 reg, reg_cnt, val;
	scom_map_t map;
	int rc;

	if (off < 0 || (off & 7) || (count & 7))
		return -EINVAL;
	reg = off >> 3;
	reg_cnt = count >> 3;

	map = scom_map(ent->dn, reg, reg_cnt);
	if (!scom_map_ok(map))
		return -ENXIO;

	for (reg = 0; reg < reg_cnt; reg++) {
		rc = scom_read(map, reg, &val);
		if (!rc)
			rc = put_user(val, ubuf64);
		if (rc) {
			if (!done)
				done = rc;
			break;
		}
		ubuf64++;
		*ppos += 8;
		done += 8;
	}
	scom_unmap(map);
	return done;
}

static ssize_t scom_debug_write(struct file* filp, const char __user *ubuf,
				size_t count, loff_t *ppos)
{
	struct scom_debug_entry *ent = filp->private_data;
	u64 __user *ubuf64 = (u64 __user *)ubuf;
	loff_t off = *ppos;
	ssize_t done = 0; 
	u64 reg, reg_cnt, val;
	scom_map_t map;
	int rc;

	if (off < 0 || (off & 7) || (count & 7))
		return -EINVAL;
	reg = off >> 3;
	reg_cnt = count >> 3;

	map = scom_map(ent->dn, reg, reg_cnt);
	if (!scom_map_ok(map))
		return -ENXIO;

	for (reg = 0; reg < reg_cnt; reg++) {
		rc = get_user(val, ubuf64);
		if (!rc)
			rc = scom_write(map, reg,  val);
		if (rc) {
			if (!done)
				done = rc;
			break;
		}
		ubuf64++;
		done += 8;
	}
	scom_unmap(map);
	return done;
}

static const struct file_operations scom_debug_fops = {
	.read =		scom_debug_read,
	.write =	scom_debug_write,
	.open =		simple_open,
	.llseek =	default_llseek,
};

static int scom_debug_init_one(struct dentry *root, struct device_node *dn,
			       int i)
{
	struct scom_debug_entry *ent;
	struct dentry *dir;

	ent = kzalloc(sizeof(*ent), GFP_KERNEL);
	if (!ent)
		return -ENOMEM;

	ent->dn = of_node_get(dn);
	snprintf(ent->name, 16, "%08x", i);
	ent->path.data = (void*)kasprintf(GFP_KERNEL, "%pOF", dn);
	ent->path.size = strlen((char *)ent->path.data);

	dir = debugfs_create_dir(ent->name, root);
	if (!dir) {
		of_node_put(dn);
		kfree(ent->path.data);
		kfree(ent);
		return -1;
	}

	debugfs_create_blob("devspec", 0400, dir, &ent->path);
	debugfs_create_file("access", 0600, dir, ent, &scom_debug_fops);

	return 0;
}

static int scom_debug_init(void)
{
	struct device_node *dn;
	struct dentry *root;
	int i, rc;

	root = debugfs_create_dir("scom", powerpc_debugfs_root);
	if (!root)
		return -1;

	i = rc = 0;
	for_each_node_with_property(dn, "scom-controller") {
		int id = of_get_ibm_chip_id(dn);
		if (id == -1)
			id = i;
		rc |= scom_debug_init_one(root, dn, id);
		i++;
	}

	return rc;
}
device_initcall(scom_debug_init);
#endif /* CONFIG_SCOM_DEBUGFS */