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Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 LT |
2 | Copyright (C) 1998, 1999 Frodo Looijaard <frodol@dds.nl> and |
3 | Philip Edelbrock <phil@netroedge.com> | |
4 | Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> | |
5 | Copyright (C) 2003 IBM Corp. | |
954a9930 | 6 | Copyright (C) 2004 Jean Delvare <khali@linux-fr.org> |
1da177e4 LT |
7 | |
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | */ | |
22 | ||
1da177e4 LT |
23 | #include <linux/kernel.h> |
24 | #include <linux/init.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/slab.h> | |
1da177e4 LT |
27 | #include <linux/jiffies.h> |
28 | #include <linux/i2c.h> | |
5c085d36 | 29 | #include <linux/mutex.h> |
1da177e4 LT |
30 | |
31 | /* Addresses to scan */ | |
2cdddeb8 | 32 | static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54, |
1da177e4 | 33 | 0x55, 0x56, 0x57, I2C_CLIENT_END }; |
1da177e4 | 34 | |
1da177e4 LT |
35 | |
36 | /* Size of EEPROM in bytes */ | |
37 | #define EEPROM_SIZE 256 | |
38 | ||
39 | /* possible types of eeprom devices */ | |
40 | enum eeprom_nature { | |
41 | UNKNOWN, | |
42 | VAIO, | |
43 | }; | |
44 | ||
45 | /* Each client has this additional data */ | |
46 | struct eeprom_data { | |
5c085d36 | 47 | struct mutex update_lock; |
1da177e4 LT |
48 | u8 valid; /* bitfield, bit!=0 if slice is valid */ |
49 | unsigned long last_updated[8]; /* In jiffies, 8 slices */ | |
50 | u8 data[EEPROM_SIZE]; /* Register values */ | |
51 | enum eeprom_nature nature; | |
52 | }; | |
53 | ||
54 | ||
1da177e4 LT |
55 | static void eeprom_update_client(struct i2c_client *client, u8 slice) |
56 | { | |
57 | struct eeprom_data *data = i2c_get_clientdata(client); | |
1b4dff9c | 58 | int i; |
1da177e4 | 59 | |
5c085d36 | 60 | mutex_lock(&data->update_lock); |
1da177e4 LT |
61 | |
62 | if (!(data->valid & (1 << slice)) || | |
63 | time_after(jiffies, data->last_updated[slice] + 300 * HZ)) { | |
64 | dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice); | |
65 | ||
66 | if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { | |
4b2643d7 JD |
67 | for (i = slice << 5; i < (slice + 1) << 5; i += 32) |
68 | if (i2c_smbus_read_i2c_block_data(client, i, | |
69 | 32, data->data + i) | |
70 | != 32) | |
1da177e4 LT |
71 | goto exit; |
72 | } else { | |
1b4dff9c JD |
73 | for (i = slice << 5; i < (slice + 1) << 5; i += 2) { |
74 | int word = i2c_smbus_read_word_data(client, i); | |
75 | if (word < 0) | |
1da177e4 | 76 | goto exit; |
1b4dff9c JD |
77 | data->data[i] = word & 0xff; |
78 | data->data[i + 1] = word >> 8; | |
1da177e4 LT |
79 | } |
80 | } | |
81 | data->last_updated[slice] = jiffies; | |
82 | data->valid |= (1 << slice); | |
83 | } | |
84 | exit: | |
5c085d36 | 85 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
86 | } |
87 | ||
91a69029 ZR |
88 | static ssize_t eeprom_read(struct kobject *kobj, struct bin_attribute *bin_attr, |
89 | char *buf, loff_t off, size_t count) | |
1da177e4 LT |
90 | { |
91 | struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj)); | |
92 | struct eeprom_data *data = i2c_get_clientdata(client); | |
93 | u8 slice; | |
94 | ||
95 | if (off > EEPROM_SIZE) | |
96 | return 0; | |
97 | if (off + count > EEPROM_SIZE) | |
98 | count = EEPROM_SIZE - off; | |
99 | ||
100 | /* Only refresh slices which contain requested bytes */ | |
101 | for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++) | |
102 | eeprom_update_client(client, slice); | |
103 | ||
0f2cbd38 JD |
104 | /* Hide Vaio private settings to regular users: |
105 | - BIOS passwords: bytes 0x00 to 0x0f | |
106 | - UUID: bytes 0x10 to 0x1f | |
107 | - Serial number: 0xc0 to 0xdf */ | |
108 | if (data->nature == VAIO && !capable(CAP_SYS_ADMIN)) { | |
109 | int i; | |
110 | ||
111 | for (i = 0; i < count; i++) { | |
112 | if ((off + i <= 0x1f) || | |
113 | (off + i >= 0xc0 && off + i <= 0xdf)) | |
114 | buf[i] = 0; | |
115 | else | |
116 | buf[i] = data->data[off + i]; | |
117 | } | |
1da177e4 LT |
118 | } else { |
119 | memcpy(buf, &data->data[off], count); | |
120 | } | |
121 | ||
122 | return count; | |
123 | } | |
124 | ||
125 | static struct bin_attribute eeprom_attr = { | |
126 | .attr = { | |
127 | .name = "eeprom", | |
128 | .mode = S_IRUGO, | |
1da177e4 LT |
129 | }, |
130 | .size = EEPROM_SIZE, | |
131 | .read = eeprom_read, | |
132 | }; | |
133 | ||
68be3363 | 134 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 135 | static int eeprom_detect(struct i2c_client *client, struct i2c_board_info *info) |
1da177e4 | 136 | { |
68be3363 | 137 | struct i2c_adapter *adapter = client->adapter; |
1da177e4 | 138 | |
d4653bf9 JD |
139 | /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all |
140 | addresses 0x50-0x57, but we only care about 0x50. So decline | |
141 | attaching to addresses >= 0x51 on DDC buses */ | |
68be3363 JD |
142 | if (!(adapter->class & I2C_CLASS_SPD) && client->addr >= 0x51) |
143 | return -ENODEV; | |
d4653bf9 | 144 | |
1b4dff9c | 145 | /* There are four ways we can read the EEPROM data: |
1da177e4 | 146 | (1) I2C block reads (faster, but unsupported by most adapters) |
1b4dff9c JD |
147 | (2) Word reads (128% overhead) |
148 | (3) Consecutive byte reads (88% overhead, unsafe) | |
149 | (4) Regular byte data reads (265% overhead) | |
150 | The third and fourth methods are not implemented by this driver | |
151 | because all known adapters support one of the first two. */ | |
152 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA) | |
153 | && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) | |
68be3363 JD |
154 | return -ENODEV; |
155 | ||
156 | strlcpy(info->type, "eeprom", I2C_NAME_SIZE); | |
157 | ||
158 | return 0; | |
159 | } | |
160 | ||
161 | static int eeprom_probe(struct i2c_client *client, | |
162 | const struct i2c_device_id *id) | |
163 | { | |
164 | struct i2c_adapter *adapter = client->adapter; | |
165 | struct eeprom_data *data; | |
166 | int err; | |
1da177e4 | 167 | |
5263ebb5 | 168 | if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) { |
1da177e4 LT |
169 | err = -ENOMEM; |
170 | goto exit; | |
171 | } | |
1da177e4 | 172 | |
1da177e4 | 173 | memset(data->data, 0xff, EEPROM_SIZE); |
f741f673 | 174 | i2c_set_clientdata(client, data); |
5c085d36 | 175 | mutex_init(&data->update_lock); |
1da177e4 LT |
176 | data->nature = UNKNOWN; |
177 | ||
1da177e4 | 178 | /* Detect the Vaio nature of EEPROMs. |
8b925a3d | 179 | We use the "PCG-" or "VGN-" prefix as the signature. */ |
68be3363 | 180 | if (client->addr == 0x57 |
1b4dff9c | 181 | && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) { |
8b925a3d JD |
182 | char name[4]; |
183 | ||
f741f673 JD |
184 | name[0] = i2c_smbus_read_byte_data(client, 0x80); |
185 | name[1] = i2c_smbus_read_byte_data(client, 0x81); | |
186 | name[2] = i2c_smbus_read_byte_data(client, 0x82); | |
187 | name[3] = i2c_smbus_read_byte_data(client, 0x83); | |
8b925a3d JD |
188 | |
189 | if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) { | |
f741f673 | 190 | dev_info(&client->dev, "Vaio EEPROM detected, " |
0f2cbd38 | 191 | "enabling privacy protection\n"); |
1da177e4 LT |
192 | data->nature = VAIO; |
193 | } | |
194 | } | |
195 | ||
196 | /* create the sysfs eeprom file */ | |
f741f673 | 197 | err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr); |
7d9db67f | 198 | if (err) |
68be3363 | 199 | goto exit_kfree; |
1da177e4 LT |
200 | |
201 | return 0; | |
202 | ||
203 | exit_kfree: | |
204 | kfree(data); | |
205 | exit: | |
206 | return err; | |
207 | } | |
208 | ||
68be3363 | 209 | static int eeprom_remove(struct i2c_client *client) |
1da177e4 | 210 | { |
7d9db67f | 211 | sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr); |
1da177e4 LT |
212 | kfree(i2c_get_clientdata(client)); |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
68be3363 JD |
217 | static const struct i2c_device_id eeprom_id[] = { |
218 | { "eeprom", 0 }, | |
219 | { } | |
220 | }; | |
221 | ||
222 | static struct i2c_driver eeprom_driver = { | |
223 | .driver = { | |
224 | .name = "eeprom", | |
225 | }, | |
226 | .probe = eeprom_probe, | |
227 | .remove = eeprom_remove, | |
228 | .id_table = eeprom_id, | |
229 | ||
230 | .class = I2C_CLASS_DDC | I2C_CLASS_SPD, | |
231 | .detect = eeprom_detect, | |
c3813d6a | 232 | .address_list = normal_i2c, |
68be3363 JD |
233 | }; |
234 | ||
1da177e4 LT |
235 | static int __init eeprom_init(void) |
236 | { | |
237 | return i2c_add_driver(&eeprom_driver); | |
238 | } | |
239 | ||
240 | static void __exit eeprom_exit(void) | |
241 | { | |
242 | i2c_del_driver(&eeprom_driver); | |
243 | } | |
244 | ||
245 | ||
246 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
247 | "Philip Edelbrock <phil@netroedge.com> and " | |
248 | "Greg Kroah-Hartman <greg@kroah.com>"); | |
249 | MODULE_DESCRIPTION("I2C EEPROM driver"); | |
250 | MODULE_LICENSE("GPL"); | |
251 | ||
252 | module_init(eeprom_init); | |
253 | module_exit(eeprom_exit); |