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1da177e4 LT |
1 | /* |
2 | eeprom.c - Part of lm_sensors, Linux kernel modules for hardware | |
3 | monitoring | |
4 | Copyright (C) 1998, 1999 Frodo Looijaard <frodol@dds.nl> and | |
5 | Philip Edelbrock <phil@netroedge.com> | |
6 | Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> | |
7 | Copyright (C) 2003 IBM Corp. | |
8 | ||
9 | 2004-01-16 Jean Delvare <khali@linux-fr.org> | |
10 | Divide the eeprom in 32-byte (arbitrary) slices. This significantly | |
11 | speeds sensors up, as well as various scripts using the eeprom | |
12 | module. | |
13 | ||
14 | This program is free software; you can redistribute it and/or modify | |
15 | it under the terms of the GNU General Public License as published by | |
16 | the Free Software Foundation; either version 2 of the License, or | |
17 | (at your option) any later version. | |
18 | ||
19 | This program is distributed in the hope that it will be useful, | |
20 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
21 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
22 | GNU General Public License for more details. | |
23 | ||
24 | You should have received a copy of the GNU General Public License | |
25 | along with this program; if not, write to the Free Software | |
26 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
27 | */ | |
28 | ||
1da177e4 LT |
29 | #include <linux/kernel.h> |
30 | #include <linux/init.h> | |
31 | #include <linux/module.h> | |
32 | #include <linux/slab.h> | |
33 | #include <linux/sched.h> | |
34 | #include <linux/jiffies.h> | |
35 | #include <linux/i2c.h> | |
5c085d36 | 36 | #include <linux/mutex.h> |
1da177e4 LT |
37 | |
38 | /* Addresses to scan */ | |
39 | static unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54, | |
40 | 0x55, 0x56, 0x57, I2C_CLIENT_END }; | |
1da177e4 LT |
41 | |
42 | /* Insmod parameters */ | |
f4b50261 | 43 | I2C_CLIENT_INSMOD_1(eeprom); |
1da177e4 LT |
44 | |
45 | ||
46 | /* Size of EEPROM in bytes */ | |
47 | #define EEPROM_SIZE 256 | |
48 | ||
49 | /* possible types of eeprom devices */ | |
50 | enum eeprom_nature { | |
51 | UNKNOWN, | |
52 | VAIO, | |
53 | }; | |
54 | ||
55 | /* Each client has this additional data */ | |
56 | struct eeprom_data { | |
57 | struct i2c_client client; | |
5c085d36 | 58 | struct mutex update_lock; |
1da177e4 LT |
59 | u8 valid; /* bitfield, bit!=0 if slice is valid */ |
60 | unsigned long last_updated[8]; /* In jiffies, 8 slices */ | |
61 | u8 data[EEPROM_SIZE]; /* Register values */ | |
62 | enum eeprom_nature nature; | |
63 | }; | |
64 | ||
65 | ||
66 | static int eeprom_attach_adapter(struct i2c_adapter *adapter); | |
67 | static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind); | |
68 | static int eeprom_detach_client(struct i2c_client *client); | |
69 | ||
70 | /* This is the driver that will be inserted */ | |
71 | static struct i2c_driver eeprom_driver = { | |
a9718b0c | 72 | .driver = { |
a9718b0c LR |
73 | .name = "eeprom", |
74 | }, | |
1da177e4 | 75 | .id = I2C_DRIVERID_EEPROM, |
1da177e4 LT |
76 | .attach_adapter = eeprom_attach_adapter, |
77 | .detach_client = eeprom_detach_client, | |
78 | }; | |
79 | ||
80 | static void eeprom_update_client(struct i2c_client *client, u8 slice) | |
81 | { | |
82 | struct eeprom_data *data = i2c_get_clientdata(client); | |
83 | int i, j; | |
84 | ||
5c085d36 | 85 | mutex_lock(&data->update_lock); |
1da177e4 LT |
86 | |
87 | if (!(data->valid & (1 << slice)) || | |
88 | time_after(jiffies, data->last_updated[slice] + 300 * HZ)) { | |
89 | dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice); | |
90 | ||
91 | if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { | |
30dac746 JD |
92 | for (i = slice << 5; i < (slice + 1) << 5; i += I2C_SMBUS_BLOCK_MAX) |
93 | if (i2c_smbus_read_i2c_block_data(client, i, data->data + i) != I2C_SMBUS_BLOCK_MAX) | |
1da177e4 LT |
94 | goto exit; |
95 | } else { | |
96 | if (i2c_smbus_write_byte(client, slice << 5)) { | |
97 | dev_dbg(&client->dev, "eeprom read start has failed!\n"); | |
98 | goto exit; | |
99 | } | |
100 | for (i = slice << 5; i < (slice + 1) << 5; i++) { | |
101 | j = i2c_smbus_read_byte(client); | |
102 | if (j < 0) | |
103 | goto exit; | |
104 | data->data[i] = (u8) j; | |
105 | } | |
106 | } | |
107 | data->last_updated[slice] = jiffies; | |
108 | data->valid |= (1 << slice); | |
109 | } | |
110 | exit: | |
5c085d36 | 111 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
112 | } |
113 | ||
114 | static ssize_t eeprom_read(struct kobject *kobj, char *buf, loff_t off, size_t count) | |
115 | { | |
116 | struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj)); | |
117 | struct eeprom_data *data = i2c_get_clientdata(client); | |
118 | u8 slice; | |
119 | ||
120 | if (off > EEPROM_SIZE) | |
121 | return 0; | |
122 | if (off + count > EEPROM_SIZE) | |
123 | count = EEPROM_SIZE - off; | |
124 | ||
125 | /* Only refresh slices which contain requested bytes */ | |
126 | for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++) | |
127 | eeprom_update_client(client, slice); | |
128 | ||
129 | /* Hide Vaio security settings to regular users (16 first bytes) */ | |
130 | if (data->nature == VAIO && off < 16 && !capable(CAP_SYS_ADMIN)) { | |
131 | size_t in_row1 = 16 - off; | |
132 | in_row1 = min(in_row1, count); | |
133 | memset(buf, 0, in_row1); | |
134 | if (count - in_row1 > 0) | |
135 | memcpy(buf + in_row1, &data->data[16], count - in_row1); | |
136 | } else { | |
137 | memcpy(buf, &data->data[off], count); | |
138 | } | |
139 | ||
140 | return count; | |
141 | } | |
142 | ||
143 | static struct bin_attribute eeprom_attr = { | |
144 | .attr = { | |
145 | .name = "eeprom", | |
146 | .mode = S_IRUGO, | |
147 | .owner = THIS_MODULE, | |
148 | }, | |
149 | .size = EEPROM_SIZE, | |
150 | .read = eeprom_read, | |
151 | }; | |
152 | ||
153 | static int eeprom_attach_adapter(struct i2c_adapter *adapter) | |
154 | { | |
2ed2dc3c | 155 | return i2c_probe(adapter, &addr_data, eeprom_detect); |
1da177e4 LT |
156 | } |
157 | ||
2ed2dc3c | 158 | /* This function is called by i2c_probe */ |
6536c49a | 159 | static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind) |
1da177e4 LT |
160 | { |
161 | struct i2c_client *new_client; | |
162 | struct eeprom_data *data; | |
163 | int err = 0; | |
164 | ||
165 | /* There are three ways we can read the EEPROM data: | |
166 | (1) I2C block reads (faster, but unsupported by most adapters) | |
167 | (2) Consecutive byte reads (100% overhead) | |
168 | (3) Regular byte data reads (200% overhead) | |
169 | The third method is not implemented by this driver because all | |
170 | known adapters support at least the second. */ | |
171 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA | |
172 | | I2C_FUNC_SMBUS_BYTE)) | |
173 | goto exit; | |
174 | ||
5263ebb5 | 175 | if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) { |
1da177e4 LT |
176 | err = -ENOMEM; |
177 | goto exit; | |
178 | } | |
1da177e4 LT |
179 | |
180 | new_client = &data->client; | |
181 | memset(data->data, 0xff, EEPROM_SIZE); | |
182 | i2c_set_clientdata(new_client, data); | |
183 | new_client->addr = address; | |
184 | new_client->adapter = adapter; | |
185 | new_client->driver = &eeprom_driver; | |
186 | new_client->flags = 0; | |
187 | ||
1da177e4 LT |
188 | /* Fill in the remaining client fields */ |
189 | strlcpy(new_client->name, "eeprom", I2C_NAME_SIZE); | |
190 | data->valid = 0; | |
5c085d36 | 191 | mutex_init(&data->update_lock); |
1da177e4 LT |
192 | data->nature = UNKNOWN; |
193 | ||
194 | /* Tell the I2C layer a new client has arrived */ | |
195 | if ((err = i2c_attach_client(new_client))) | |
196 | goto exit_kfree; | |
197 | ||
198 | /* Detect the Vaio nature of EEPROMs. | |
199 | We use the "PCG-" prefix as the signature. */ | |
200 | if (address == 0x57) { | |
201 | if (i2c_smbus_read_byte_data(new_client, 0x80) == 'P' | |
202 | && i2c_smbus_read_byte(new_client) == 'C' | |
203 | && i2c_smbus_read_byte(new_client) == 'G' | |
204 | && i2c_smbus_read_byte(new_client) == '-') { | |
205 | dev_info(&new_client->dev, "Vaio EEPROM detected, " | |
206 | "enabling password protection\n"); | |
207 | data->nature = VAIO; | |
208 | } | |
209 | } | |
210 | ||
211 | /* create the sysfs eeprom file */ | |
7d9db67f JD |
212 | err = sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr); |
213 | if (err) | |
214 | goto exit_detach; | |
1da177e4 LT |
215 | |
216 | return 0; | |
217 | ||
7d9db67f JD |
218 | exit_detach: |
219 | i2c_detach_client(new_client); | |
1da177e4 LT |
220 | exit_kfree: |
221 | kfree(data); | |
222 | exit: | |
223 | return err; | |
224 | } | |
225 | ||
226 | static int eeprom_detach_client(struct i2c_client *client) | |
227 | { | |
228 | int err; | |
229 | ||
7d9db67f JD |
230 | sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr); |
231 | ||
1da177e4 | 232 | err = i2c_detach_client(client); |
7bef5594 | 233 | if (err) |
1da177e4 | 234 | return err; |
1da177e4 LT |
235 | |
236 | kfree(i2c_get_clientdata(client)); | |
237 | ||
238 | return 0; | |
239 | } | |
240 | ||
241 | static int __init eeprom_init(void) | |
242 | { | |
243 | return i2c_add_driver(&eeprom_driver); | |
244 | } | |
245 | ||
246 | static void __exit eeprom_exit(void) | |
247 | { | |
248 | i2c_del_driver(&eeprom_driver); | |
249 | } | |
250 | ||
251 | ||
252 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
253 | "Philip Edelbrock <phil@netroedge.com> and " | |
254 | "Greg Kroah-Hartman <greg@kroah.com>"); | |
255 | MODULE_DESCRIPTION("I2C EEPROM driver"); | |
256 | MODULE_LICENSE("GPL"); | |
257 | ||
258 | module_init(eeprom_init); | |
259 | module_exit(eeprom_exit); |