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
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
|
/*
eeprom.c - Part of lm_sensors, Linux kernel modules for hardware
monitoring
Copyright (C) 1998, 1999 Frodo Looijaard <frodol@dds.nl> and
Philip Edelbrock <phil@netroedge.com>
Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
Copyright (C) 2003 IBM Corp.
2004-01-16 Jean Delvare <khali@linux-fr.org>
Divide the eeprom in 32-byte (arbitrary) slices. This significantly
speeds sensors up, as well as various scripts using the eeprom
module.
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
/* Addresses to scan */
static unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54,
0x55, 0x56, 0x57, I2C_CLIENT_END };
/* Insmod parameters */
I2C_CLIENT_INSMOD_1(eeprom);
/* Size of EEPROM in bytes */
#define EEPROM_SIZE 256
/* possible types of eeprom devices */
enum eeprom_nature {
UNKNOWN,
VAIO,
};
/* Each client has this additional data */
struct eeprom_data {
struct i2c_client client;
struct semaphore update_lock;
u8 valid; /* bitfield, bit!=0 if slice is valid */
unsigned long last_updated[8]; /* In jiffies, 8 slices */
u8 data[EEPROM_SIZE]; /* Register values */
enum eeprom_nature nature;
};
static int eeprom_attach_adapter(struct i2c_adapter *adapter);
static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind);
static int eeprom_detach_client(struct i2c_client *client);
/* This is the driver that will be inserted */
static struct i2c_driver eeprom_driver = {
.owner = THIS_MODULE,
.name = "eeprom",
.id = I2C_DRIVERID_EEPROM,
.flags = I2C_DF_NOTIFY,
.attach_adapter = eeprom_attach_adapter,
.detach_client = eeprom_detach_client,
};
static void eeprom_update_client(struct i2c_client *client, u8 slice)
{
struct eeprom_data *data = i2c_get_clientdata(client);
int i, j;
down(&data->update_lock);
if (!(data->valid & (1 << slice)) ||
time_after(jiffies, data->last_updated[slice] + 300 * HZ)) {
dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice);
if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
for (i = slice << 5; i < (slice + 1) << 5; i += I2C_SMBUS_BLOCK_MAX)
if (i2c_smbus_read_i2c_block_data(client, i, data->data + i) != I2C_SMBUS_BLOCK_MAX)
goto exit;
} else {
if (i2c_smbus_write_byte(client, slice << 5)) {
dev_dbg(&client->dev, "eeprom read start has failed!\n");
goto exit;
}
for (i = slice << 5; i < (slice + 1) << 5; i++) {
j = i2c_smbus_read_byte(client);
if (j < 0)
goto exit;
data->data[i] = (u8) j;
}
}
data->last_updated[slice] = jiffies;
data->valid |= (1 << slice);
}
exit:
up(&data->update_lock);
}
static ssize_t eeprom_read(struct kobject *kobj, char *buf, loff_t off, size_t count)
{
struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj));
struct eeprom_data *data = i2c_get_clientdata(client);
u8 slice;
if (off > EEPROM_SIZE)
return 0;
if (off + count > EEPROM_SIZE)
count = EEPROM_SIZE - off;
/* Only refresh slices which contain requested bytes */
for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++)
eeprom_update_client(client, slice);
/* Hide Vaio security settings to regular users (16 first bytes) */
if (data->nature == VAIO && off < 16 && !capable(CAP_SYS_ADMIN)) {
size_t in_row1 = 16 - off;
in_row1 = min(in_row1, count);
memset(buf, 0, in_row1);
if (count - in_row1 > 0)
memcpy(buf + in_row1, &data->data[16], count - in_row1);
} else {
memcpy(buf, &data->data[off], count);
}
return count;
}
static struct bin_attribute eeprom_attr = {
.attr = {
.name = "eeprom",
.mode = S_IRUGO,
.owner = THIS_MODULE,
},
.size = EEPROM_SIZE,
.read = eeprom_read,
};
static int eeprom_attach_adapter(struct i2c_adapter *adapter)
{
return i2c_probe(adapter, &addr_data, eeprom_detect);
}
/* This function is called by i2c_probe */
int eeprom_detect(struct i2c_adapter *adapter, int address, int kind)
{
struct i2c_client *new_client;
struct eeprom_data *data;
int err = 0;
/* There are three ways we can read the EEPROM data:
(1) I2C block reads (faster, but unsupported by most adapters)
(2) Consecutive byte reads (100% overhead)
(3) Regular byte data reads (200% overhead)
The third method is not implemented by this driver because all
known adapters support at least the second. */
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA
| I2C_FUNC_SMBUS_BYTE))
goto exit;
if (!(data = kmalloc(sizeof(struct eeprom_data), GFP_KERNEL))) {
err = -ENOMEM;
goto exit;
}
memset(data, 0, sizeof(struct eeprom_data));
new_client = &data->client;
memset(data->data, 0xff, EEPROM_SIZE);
i2c_set_clientdata(new_client, data);
new_client->addr = address;
new_client->adapter = adapter;
new_client->driver = &eeprom_driver;
new_client->flags = 0;
/* Fill in the remaining client fields */
strlcpy(new_client->name, "eeprom", I2C_NAME_SIZE);
data->valid = 0;
init_MUTEX(&data->update_lock);
data->nature = UNKNOWN;
/* Tell the I2C layer a new client has arrived */
if ((err = i2c_attach_client(new_client)))
goto exit_kfree;
/* Detect the Vaio nature of EEPROMs.
We use the "PCG-" prefix as the signature. */
if (address == 0x57) {
if (i2c_smbus_read_byte_data(new_client, 0x80) == 'P'
&& i2c_smbus_read_byte(new_client) == 'C'
&& i2c_smbus_read_byte(new_client) == 'G'
&& i2c_smbus_read_byte(new_client) == '-') {
dev_info(&new_client->dev, "Vaio EEPROM detected, "
"enabling password protection\n");
data->nature = VAIO;
}
}
/* create the sysfs eeprom file */
sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr);
return 0;
exit_kfree:
kfree(data);
exit:
return err;
}
static int eeprom_detach_client(struct i2c_client *client)
{
int err;
err = i2c_detach_client(client);
if (err)
return err;
kfree(i2c_get_clientdata(client));
return 0;
}
static int __init eeprom_init(void)
{
return i2c_add_driver(&eeprom_driver);
}
static void __exit eeprom_exit(void)
{
i2c_del_driver(&eeprom_driver);
}
MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
"Philip Edelbrock <phil@netroedge.com> and "
"Greg Kroah-Hartman <greg@kroah.com>");
MODULE_DESCRIPTION("I2C EEPROM driver");
MODULE_LICENSE("GPL");
module_init(eeprom_init);
module_exit(eeprom_exit);
|
