diff options
author | Wolfram Sang <w.sang@pengutronix.de> | 2009-01-26 15:19:53 -0500 |
---|---|---|
committer | Jean Delvare <khali@linux-fr.org> | 2009-01-26 15:19:53 -0500 |
commit | 2e157888f132131f8877affd2785dcee4c227c1d (patch) | |
tree | 02cc5eb10e6264fc06da8e2c3d54beeea79887d7 /drivers/misc/eeprom | |
parent | 5195e5093bb7d30dbf057b260005cb4ab9761168 (diff) |
i2c: Move old eeprom driver to /drivers/misc/eeprom
Update Kconfig text to specify this driver as I2C.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Diffstat (limited to 'drivers/misc/eeprom')
-rw-r--r-- | drivers/misc/eeprom/Kconfig | 11 | ||||
-rw-r--r-- | drivers/misc/eeprom/Makefile | 1 | ||||
-rw-r--r-- | drivers/misc/eeprom/eeprom.c | 257 |
3 files changed, 269 insertions, 0 deletions
diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig index 0b21778b7d13..3d31b6644245 100644 --- a/drivers/misc/eeprom/Kconfig +++ b/drivers/misc/eeprom/Kconfig | |||
@@ -26,4 +26,15 @@ config AT24 | |||
26 | This driver can also be built as a module. If so, the module | 26 | This driver can also be built as a module. If so, the module |
27 | will be called at24. | 27 | will be called at24. |
28 | 28 | ||
29 | config SENSORS_EEPROM | ||
30 | tristate "Old I2C EEPROM reader" | ||
31 | depends on I2C && EXPERIMENTAL | ||
32 | help | ||
33 | If you say yes here you get read-only access to the EEPROM data | ||
34 | available on modern memory DIMMs and Sony Vaio laptops via I2C. Such | ||
35 | EEPROMs could theoretically be available on other devices as well. | ||
36 | |||
37 | This driver can also be built as a module. If so, the module | ||
38 | will be called eeprom. | ||
39 | |||
29 | endmenu | 40 | endmenu |
diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile index 72cd478eb53f..a3dad28f2724 100644 --- a/drivers/misc/eeprom/Makefile +++ b/drivers/misc/eeprom/Makefile | |||
@@ -1 +1,2 @@ | |||
1 | obj-$(CONFIG_AT24) += at24.o | 1 | obj-$(CONFIG_AT24) += at24.o |
2 | obj-$(CONFIG_SENSORS_EEPROM) += eeprom.o | ||
diff --git a/drivers/misc/eeprom/eeprom.c b/drivers/misc/eeprom/eeprom.c new file mode 100644 index 000000000000..2c27193aeaa0 --- /dev/null +++ b/drivers/misc/eeprom/eeprom.c | |||
@@ -0,0 +1,257 @@ | |||
1 | /* | ||
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. | ||
6 | Copyright (C) 2004 Jean Delvare <khali@linux-fr.org> | ||
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 | |||
23 | #include <linux/kernel.h> | ||
24 | #include <linux/init.h> | ||
25 | #include <linux/module.h> | ||
26 | #include <linux/slab.h> | ||
27 | #include <linux/jiffies.h> | ||
28 | #include <linux/i2c.h> | ||
29 | #include <linux/mutex.h> | ||
30 | |||
31 | /* Addresses to scan */ | ||
32 | static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54, | ||
33 | 0x55, 0x56, 0x57, I2C_CLIENT_END }; | ||
34 | |||
35 | /* Insmod parameters */ | ||
36 | I2C_CLIENT_INSMOD_1(eeprom); | ||
37 | |||
38 | |||
39 | /* Size of EEPROM in bytes */ | ||
40 | #define EEPROM_SIZE 256 | ||
41 | |||
42 | /* possible types of eeprom devices */ | ||
43 | enum eeprom_nature { | ||
44 | UNKNOWN, | ||
45 | VAIO, | ||
46 | }; | ||
47 | |||
48 | /* Each client has this additional data */ | ||
49 | struct eeprom_data { | ||
50 | struct mutex update_lock; | ||
51 | u8 valid; /* bitfield, bit!=0 if slice is valid */ | ||
52 | unsigned long last_updated[8]; /* In jiffies, 8 slices */ | ||
53 | u8 data[EEPROM_SIZE]; /* Register values */ | ||
54 | enum eeprom_nature nature; | ||
55 | }; | ||
56 | |||
57 | |||
58 | static void eeprom_update_client(struct i2c_client *client, u8 slice) | ||
59 | { | ||
60 | struct eeprom_data *data = i2c_get_clientdata(client); | ||
61 | int i; | ||
62 | |||
63 | mutex_lock(&data->update_lock); | ||
64 | |||
65 | if (!(data->valid & (1 << slice)) || | ||
66 | time_after(jiffies, data->last_updated[slice] + 300 * HZ)) { | ||
67 | dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice); | ||
68 | |||
69 | if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { | ||
70 | for (i = slice << 5; i < (slice + 1) << 5; i += 32) | ||
71 | if (i2c_smbus_read_i2c_block_data(client, i, | ||
72 | 32, data->data + i) | ||
73 | != 32) | ||
74 | goto exit; | ||
75 | } else { | ||
76 | for (i = slice << 5; i < (slice + 1) << 5; i += 2) { | ||
77 | int word = i2c_smbus_read_word_data(client, i); | ||
78 | if (word < 0) | ||
79 | goto exit; | ||
80 | data->data[i] = word & 0xff; | ||
81 | data->data[i + 1] = word >> 8; | ||
82 | } | ||
83 | } | ||
84 | data->last_updated[slice] = jiffies; | ||
85 | data->valid |= (1 << slice); | ||
86 | } | ||
87 | exit: | ||
88 | mutex_unlock(&data->update_lock); | ||
89 | } | ||
90 | |||
91 | static ssize_t eeprom_read(struct kobject *kobj, struct bin_attribute *bin_attr, | ||
92 | char *buf, loff_t off, size_t count) | ||
93 | { | ||
94 | struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj)); | ||
95 | struct eeprom_data *data = i2c_get_clientdata(client); | ||
96 | u8 slice; | ||
97 | |||
98 | if (off > EEPROM_SIZE) | ||
99 | return 0; | ||
100 | if (off + count > EEPROM_SIZE) | ||
101 | count = EEPROM_SIZE - off; | ||
102 | |||
103 | /* Only refresh slices which contain requested bytes */ | ||
104 | for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++) | ||
105 | eeprom_update_client(client, slice); | ||
106 | |||
107 | /* Hide Vaio private settings to regular users: | ||
108 | - BIOS passwords: bytes 0x00 to 0x0f | ||
109 | - UUID: bytes 0x10 to 0x1f | ||
110 | - Serial number: 0xc0 to 0xdf */ | ||
111 | if (data->nature == VAIO && !capable(CAP_SYS_ADMIN)) { | ||
112 | int i; | ||
113 | |||
114 | for (i = 0; i < count; i++) { | ||
115 | if ((off + i <= 0x1f) || | ||
116 | (off + i >= 0xc0 && off + i <= 0xdf)) | ||
117 | buf[i] = 0; | ||
118 | else | ||
119 | buf[i] = data->data[off + i]; | ||
120 | } | ||
121 | } else { | ||
122 | memcpy(buf, &data->data[off], count); | ||
123 | } | ||
124 | |||
125 | return count; | ||
126 | } | ||
127 | |||
128 | static struct bin_attribute eeprom_attr = { | ||
129 | .attr = { | ||
130 | .name = "eeprom", | ||
131 | .mode = S_IRUGO, | ||
132 | }, | ||
133 | .size = EEPROM_SIZE, | ||
134 | .read = eeprom_read, | ||
135 | }; | ||
136 | |||
137 | /* Return 0 if detection is successful, -ENODEV otherwise */ | ||
138 | static int eeprom_detect(struct i2c_client *client, int kind, | ||
139 | struct i2c_board_info *info) | ||
140 | { | ||
141 | struct i2c_adapter *adapter = client->adapter; | ||
142 | |||
143 | /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all | ||
144 | addresses 0x50-0x57, but we only care about 0x50. So decline | ||
145 | attaching to addresses >= 0x51 on DDC buses */ | ||
146 | if (!(adapter->class & I2C_CLASS_SPD) && client->addr >= 0x51) | ||
147 | return -ENODEV; | ||
148 | |||
149 | /* There are four ways we can read the EEPROM data: | ||
150 | (1) I2C block reads (faster, but unsupported by most adapters) | ||
151 | (2) Word reads (128% overhead) | ||
152 | (3) Consecutive byte reads (88% overhead, unsafe) | ||
153 | (4) Regular byte data reads (265% overhead) | ||
154 | The third and fourth methods are not implemented by this driver | ||
155 | because all known adapters support one of the first two. */ | ||
156 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA) | ||
157 | && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) | ||
158 | return -ENODEV; | ||
159 | |||
160 | strlcpy(info->type, "eeprom", I2C_NAME_SIZE); | ||
161 | |||
162 | return 0; | ||
163 | } | ||
164 | |||
165 | static int eeprom_probe(struct i2c_client *client, | ||
166 | const struct i2c_device_id *id) | ||
167 | { | ||
168 | struct i2c_adapter *adapter = client->adapter; | ||
169 | struct eeprom_data *data; | ||
170 | int err; | ||
171 | |||
172 | if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) { | ||
173 | err = -ENOMEM; | ||
174 | goto exit; | ||
175 | } | ||
176 | |||
177 | memset(data->data, 0xff, EEPROM_SIZE); | ||
178 | i2c_set_clientdata(client, data); | ||
179 | mutex_init(&data->update_lock); | ||
180 | data->nature = UNKNOWN; | ||
181 | |||
182 | /* Detect the Vaio nature of EEPROMs. | ||
183 | We use the "PCG-" or "VGN-" prefix as the signature. */ | ||
184 | if (client->addr == 0x57 | ||
185 | && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) { | ||
186 | char name[4]; | ||
187 | |||
188 | name[0] = i2c_smbus_read_byte_data(client, 0x80); | ||
189 | name[1] = i2c_smbus_read_byte_data(client, 0x81); | ||
190 | name[2] = i2c_smbus_read_byte_data(client, 0x82); | ||
191 | name[3] = i2c_smbus_read_byte_data(client, 0x83); | ||
192 | |||
193 | if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) { | ||
194 | dev_info(&client->dev, "Vaio EEPROM detected, " | ||
195 | "enabling privacy protection\n"); | ||
196 | data->nature = VAIO; | ||
197 | } | ||
198 | } | ||
199 | |||
200 | /* create the sysfs eeprom file */ | ||
201 | err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr); | ||
202 | if (err) | ||
203 | goto exit_kfree; | ||
204 | |||
205 | return 0; | ||
206 | |||
207 | exit_kfree: | ||
208 | kfree(data); | ||
209 | exit: | ||
210 | return err; | ||
211 | } | ||
212 | |||
213 | static int eeprom_remove(struct i2c_client *client) | ||
214 | { | ||
215 | sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr); | ||
216 | kfree(i2c_get_clientdata(client)); | ||
217 | |||
218 | return 0; | ||
219 | } | ||
220 | |||
221 | static const struct i2c_device_id eeprom_id[] = { | ||
222 | { "eeprom", 0 }, | ||
223 | { } | ||
224 | }; | ||
225 | |||
226 | static struct i2c_driver eeprom_driver = { | ||
227 | .driver = { | ||
228 | .name = "eeprom", | ||
229 | }, | ||
230 | .probe = eeprom_probe, | ||
231 | .remove = eeprom_remove, | ||
232 | .id_table = eeprom_id, | ||
233 | |||
234 | .class = I2C_CLASS_DDC | I2C_CLASS_SPD, | ||
235 | .detect = eeprom_detect, | ||
236 | .address_data = &addr_data, | ||
237 | }; | ||
238 | |||
239 | static int __init eeprom_init(void) | ||
240 | { | ||
241 | return i2c_add_driver(&eeprom_driver); | ||
242 | } | ||
243 | |||
244 | static void __exit eeprom_exit(void) | ||
245 | { | ||
246 | i2c_del_driver(&eeprom_driver); | ||
247 | } | ||
248 | |||
249 | |||
250 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | ||
251 | "Philip Edelbrock <phil@netroedge.com> and " | ||
252 | "Greg Kroah-Hartman <greg@kroah.com>"); | ||
253 | MODULE_DESCRIPTION("I2C EEPROM driver"); | ||
254 | MODULE_LICENSE("GPL"); | ||
255 | |||
256 | module_init(eeprom_init); | ||
257 | module_exit(eeprom_exit); | ||