diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/i2c/chips/eeprom.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/i2c/chips/eeprom.c')
-rw-r--r-- | drivers/i2c/chips/eeprom.c | 264 |
1 files changed, 264 insertions, 0 deletions
diff --git a/drivers/i2c/chips/eeprom.c b/drivers/i2c/chips/eeprom.c new file mode 100644 index 000000000000..cbdfa2db6f7c --- /dev/null +++ b/drivers/i2c/chips/eeprom.c | |||
@@ -0,0 +1,264 @@ | |||
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 | |||
29 | #include <linux/config.h> | ||
30 | #include <linux/kernel.h> | ||
31 | #include <linux/init.h> | ||
32 | #include <linux/module.h> | ||
33 | #include <linux/slab.h> | ||
34 | #include <linux/sched.h> | ||
35 | #include <linux/jiffies.h> | ||
36 | #include <linux/i2c.h> | ||
37 | #include <linux/i2c-sensor.h> | ||
38 | |||
39 | /* Addresses to scan */ | ||
40 | static unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54, | ||
41 | 0x55, 0x56, 0x57, I2C_CLIENT_END }; | ||
42 | static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; | ||
43 | |||
44 | /* Insmod parameters */ | ||
45 | SENSORS_INSMOD_1(eeprom); | ||
46 | |||
47 | |||
48 | /* Size of EEPROM in bytes */ | ||
49 | #define EEPROM_SIZE 256 | ||
50 | |||
51 | /* possible types of eeprom devices */ | ||
52 | enum eeprom_nature { | ||
53 | UNKNOWN, | ||
54 | VAIO, | ||
55 | }; | ||
56 | |||
57 | /* Each client has this additional data */ | ||
58 | struct eeprom_data { | ||
59 | struct i2c_client client; | ||
60 | struct semaphore update_lock; | ||
61 | u8 valid; /* bitfield, bit!=0 if slice is valid */ | ||
62 | unsigned long last_updated[8]; /* In jiffies, 8 slices */ | ||
63 | u8 data[EEPROM_SIZE]; /* Register values */ | ||
64 | enum eeprom_nature nature; | ||
65 | }; | ||
66 | |||
67 | |||
68 | static int eeprom_attach_adapter(struct i2c_adapter *adapter); | ||
69 | static int eeprom_detect(struct i2c_adapter *adapter, int address, int kind); | ||
70 | static int eeprom_detach_client(struct i2c_client *client); | ||
71 | |||
72 | /* This is the driver that will be inserted */ | ||
73 | static struct i2c_driver eeprom_driver = { | ||
74 | .owner = THIS_MODULE, | ||
75 | .name = "eeprom", | ||
76 | .id = I2C_DRIVERID_EEPROM, | ||
77 | .flags = I2C_DF_NOTIFY, | ||
78 | .attach_adapter = eeprom_attach_adapter, | ||
79 | .detach_client = eeprom_detach_client, | ||
80 | }; | ||
81 | |||
82 | static void eeprom_update_client(struct i2c_client *client, u8 slice) | ||
83 | { | ||
84 | struct eeprom_data *data = i2c_get_clientdata(client); | ||
85 | int i, j; | ||
86 | |||
87 | down(&data->update_lock); | ||
88 | |||
89 | if (!(data->valid & (1 << slice)) || | ||
90 | time_after(jiffies, data->last_updated[slice] + 300 * HZ)) { | ||
91 | dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice); | ||
92 | |||
93 | if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { | ||
94 | for (i = slice << 5; i < (slice + 1) << 5; i += I2C_SMBUS_I2C_BLOCK_MAX) | ||
95 | if (i2c_smbus_read_i2c_block_data(client, i, data->data + i) != I2C_SMBUS_I2C_BLOCK_MAX) | ||
96 | goto exit; | ||
97 | } else { | ||
98 | if (i2c_smbus_write_byte(client, slice << 5)) { | ||
99 | dev_dbg(&client->dev, "eeprom read start has failed!\n"); | ||
100 | goto exit; | ||
101 | } | ||
102 | for (i = slice << 5; i < (slice + 1) << 5; i++) { | ||
103 | j = i2c_smbus_read_byte(client); | ||
104 | if (j < 0) | ||
105 | goto exit; | ||
106 | data->data[i] = (u8) j; | ||
107 | } | ||
108 | } | ||
109 | data->last_updated[slice] = jiffies; | ||
110 | data->valid |= (1 << slice); | ||
111 | } | ||
112 | exit: | ||
113 | up(&data->update_lock); | ||
114 | } | ||
115 | |||
116 | static ssize_t eeprom_read(struct kobject *kobj, char *buf, loff_t off, size_t count) | ||
117 | { | ||
118 | struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj)); | ||
119 | struct eeprom_data *data = i2c_get_clientdata(client); | ||
120 | u8 slice; | ||
121 | |||
122 | if (off > EEPROM_SIZE) | ||
123 | return 0; | ||
124 | if (off + count > EEPROM_SIZE) | ||
125 | count = EEPROM_SIZE - off; | ||
126 | |||
127 | /* Only refresh slices which contain requested bytes */ | ||
128 | for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++) | ||
129 | eeprom_update_client(client, slice); | ||
130 | |||
131 | /* Hide Vaio security settings to regular users (16 first bytes) */ | ||
132 | if (data->nature == VAIO && off < 16 && !capable(CAP_SYS_ADMIN)) { | ||
133 | size_t in_row1 = 16 - off; | ||
134 | in_row1 = min(in_row1, count); | ||
135 | memset(buf, 0, in_row1); | ||
136 | if (count - in_row1 > 0) | ||
137 | memcpy(buf + in_row1, &data->data[16], count - in_row1); | ||
138 | } else { | ||
139 | memcpy(buf, &data->data[off], count); | ||
140 | } | ||
141 | |||
142 | return count; | ||
143 | } | ||
144 | |||
145 | static struct bin_attribute eeprom_attr = { | ||
146 | .attr = { | ||
147 | .name = "eeprom", | ||
148 | .mode = S_IRUGO, | ||
149 | .owner = THIS_MODULE, | ||
150 | }, | ||
151 | .size = EEPROM_SIZE, | ||
152 | .read = eeprom_read, | ||
153 | }; | ||
154 | |||
155 | static int eeprom_attach_adapter(struct i2c_adapter *adapter) | ||
156 | { | ||
157 | return i2c_detect(adapter, &addr_data, eeprom_detect); | ||
158 | } | ||
159 | |||
160 | /* This function is called by i2c_detect */ | ||
161 | int eeprom_detect(struct i2c_adapter *adapter, int address, int kind) | ||
162 | { | ||
163 | struct i2c_client *new_client; | ||
164 | struct eeprom_data *data; | ||
165 | int err = 0; | ||
166 | |||
167 | /* There are three ways we can read the EEPROM data: | ||
168 | (1) I2C block reads (faster, but unsupported by most adapters) | ||
169 | (2) Consecutive byte reads (100% overhead) | ||
170 | (3) Regular byte data reads (200% overhead) | ||
171 | The third method is not implemented by this driver because all | ||
172 | known adapters support at least the second. */ | ||
173 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA | ||
174 | | I2C_FUNC_SMBUS_BYTE)) | ||
175 | goto exit; | ||
176 | |||
177 | /* OK. For now, we presume we have a valid client. We now create the | ||
178 | client structure, even though we cannot fill it completely yet. | ||
179 | But it allows us to access eeprom_{read,write}_value. */ | ||
180 | if (!(data = kmalloc(sizeof(struct eeprom_data), GFP_KERNEL))) { | ||
181 | err = -ENOMEM; | ||
182 | goto exit; | ||
183 | } | ||
184 | memset(data, 0, sizeof(struct eeprom_data)); | ||
185 | |||
186 | new_client = &data->client; | ||
187 | memset(data->data, 0xff, EEPROM_SIZE); | ||
188 | i2c_set_clientdata(new_client, data); | ||
189 | new_client->addr = address; | ||
190 | new_client->adapter = adapter; | ||
191 | new_client->driver = &eeprom_driver; | ||
192 | new_client->flags = 0; | ||
193 | |||
194 | /* prevent 24RF08 corruption */ | ||
195 | i2c_smbus_write_quick(new_client, 0); | ||
196 | |||
197 | /* Fill in the remaining client fields */ | ||
198 | strlcpy(new_client->name, "eeprom", I2C_NAME_SIZE); | ||
199 | data->valid = 0; | ||
200 | init_MUTEX(&data->update_lock); | ||
201 | data->nature = UNKNOWN; | ||
202 | |||
203 | /* Tell the I2C layer a new client has arrived */ | ||
204 | if ((err = i2c_attach_client(new_client))) | ||
205 | goto exit_kfree; | ||
206 | |||
207 | /* Detect the Vaio nature of EEPROMs. | ||
208 | We use the "PCG-" prefix as the signature. */ | ||
209 | if (address == 0x57) { | ||
210 | if (i2c_smbus_read_byte_data(new_client, 0x80) == 'P' | ||
211 | && i2c_smbus_read_byte(new_client) == 'C' | ||
212 | && i2c_smbus_read_byte(new_client) == 'G' | ||
213 | && i2c_smbus_read_byte(new_client) == '-') { | ||
214 | dev_info(&new_client->dev, "Vaio EEPROM detected, " | ||
215 | "enabling password protection\n"); | ||
216 | data->nature = VAIO; | ||
217 | } | ||
218 | } | ||
219 | |||
220 | /* create the sysfs eeprom file */ | ||
221 | sysfs_create_bin_file(&new_client->dev.kobj, &eeprom_attr); | ||
222 | |||
223 | return 0; | ||
224 | |||
225 | exit_kfree: | ||
226 | kfree(data); | ||
227 | exit: | ||
228 | return err; | ||
229 | } | ||
230 | |||
231 | static int eeprom_detach_client(struct i2c_client *client) | ||
232 | { | ||
233 | int err; | ||
234 | |||
235 | err = i2c_detach_client(client); | ||
236 | if (err) { | ||
237 | dev_err(&client->dev, "Client deregistration failed, client not detached.\n"); | ||
238 | return err; | ||
239 | } | ||
240 | |||
241 | kfree(i2c_get_clientdata(client)); | ||
242 | |||
243 | return 0; | ||
244 | } | ||
245 | |||
246 | static int __init eeprom_init(void) | ||
247 | { | ||
248 | return i2c_add_driver(&eeprom_driver); | ||
249 | } | ||
250 | |||
251 | static void __exit eeprom_exit(void) | ||
252 | { | ||
253 | i2c_del_driver(&eeprom_driver); | ||
254 | } | ||
255 | |||
256 | |||
257 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | ||
258 | "Philip Edelbrock <phil@netroedge.com> and " | ||
259 | "Greg Kroah-Hartman <greg@kroah.com>"); | ||
260 | MODULE_DESCRIPTION("I2C EEPROM driver"); | ||
261 | MODULE_LICENSE("GPL"); | ||
262 | |||
263 | module_init(eeprom_init); | ||
264 | module_exit(eeprom_exit); | ||