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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 <jdelvare@suse.de>
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
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22#include <linux/jiffies.h>
23#include <linux/i2c.h>
24#include <linux/mutex.h>
25
26/* Addresses to scan */
27static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54,
28 0x55, 0x56, 0x57, I2C_CLIENT_END };
29
30
31/* Size of EEPROM in bytes */
32#define EEPROM_SIZE 256
33
34/* possible types of eeprom devices */
35enum eeprom_nature {
36 UNKNOWN,
37 VAIO,
38};
39
40/* Each client has this additional data */
41struct eeprom_data {
42 struct mutex update_lock;
43 u8 valid; /* bitfield, bit!=0 if slice is valid */
44 unsigned long last_updated[8]; /* In jiffies, 8 slices */
45 u8 data[EEPROM_SIZE]; /* Register values */
46 enum eeprom_nature nature;
47};
48
49
50static void eeprom_update_client(struct i2c_client *client, u8 slice)
51{
52 struct eeprom_data *data = i2c_get_clientdata(client);
53 int i;
54
55 mutex_lock(&data->update_lock);
56
57 if (!(data->valid & (1 << slice)) ||
58 time_after(jiffies, data->last_updated[slice] + 300 * HZ)) {
59 dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice);
60
61 if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
62 for (i = slice << 5; i < (slice + 1) << 5; i += 32)
63 if (i2c_smbus_read_i2c_block_data(client, i,
64 32, data->data + i)
65 != 32)
66 goto exit;
67 } else {
68 for (i = slice << 5; i < (slice + 1) << 5; i += 2) {
69 int word = i2c_smbus_read_word_data(client, i);
70 if (word < 0)
71 goto exit;
72 data->data[i] = word & 0xff;
73 data->data[i + 1] = word >> 8;
74 }
75 }
76 data->last_updated[slice] = jiffies;
77 data->valid |= (1 << slice);
78 }
79exit:
80 mutex_unlock(&data->update_lock);
81}
82
83static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
84 struct bin_attribute *bin_attr,
85 char *buf, loff_t off, size_t count)
86{
87 struct i2c_client *client = to_i2c_client(container_of(kobj, struct device, kobj));
88 struct eeprom_data *data = i2c_get_clientdata(client);
89 u8 slice;
90
91 if (off > EEPROM_SIZE)
92 return 0;
93 if (off + count > EEPROM_SIZE)
94 count = EEPROM_SIZE - off;
95
96 /* Only refresh slices which contain requested bytes */
97 for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++)
98 eeprom_update_client(client, slice);
99
100 /* Hide Vaio private settings to regular users:
101 - BIOS passwords: bytes 0x00 to 0x0f
102 - UUID: bytes 0x10 to 0x1f
103 - Serial number: 0xc0 to 0xdf */
104 if (data->nature == VAIO && !capable(CAP_SYS_ADMIN)) {
105 int i;
106
107 for (i = 0; i < count; i++) {
108 if ((off + i <= 0x1f) ||
109 (off + i >= 0xc0 && off + i <= 0xdf))
110 buf[i] = 0;
111 else
112 buf[i] = data->data[off + i];
113 }
114 } else {
115 memcpy(buf, &data->data[off], count);
116 }
117
118 return count;
119}
120
121static struct bin_attribute eeprom_attr = {
122 .attr = {
123 .name = "eeprom",
124 .mode = S_IRUGO,
125 },
126 .size = EEPROM_SIZE,
127 .read = eeprom_read,
128};
129
130/* Return 0 if detection is successful, -ENODEV otherwise */
131static int eeprom_detect(struct i2c_client *client, struct i2c_board_info *info)
132{
133 struct i2c_adapter *adapter = client->adapter;
134
135 /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all
136 addresses 0x50-0x57, but we only care about 0x50. So decline
137 attaching to addresses >= 0x51 on DDC buses */
138 if (!(adapter->class & I2C_CLASS_SPD) && client->addr >= 0x51)
139 return -ENODEV;
140
141 /* There are four ways we can read the EEPROM data:
142 (1) I2C block reads (faster, but unsupported by most adapters)
143 (2) Word reads (128% overhead)
144 (3) Consecutive byte reads (88% overhead, unsafe)
145 (4) Regular byte data reads (265% overhead)
146 The third and fourth methods are not implemented by this driver
147 because all known adapters support one of the first two. */
148 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)
149 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
150 return -ENODEV;
151
152 strlcpy(info->type, "eeprom", I2C_NAME_SIZE);
153
154 return 0;
155}
156
157static int eeprom_probe(struct i2c_client *client,
158 const struct i2c_device_id *id)
159{
160 struct i2c_adapter *adapter = client->adapter;
161 struct eeprom_data *data;
162 int err;
163
164 if (!(data = kzalloc(sizeof(struct eeprom_data), GFP_KERNEL))) {
165 err = -ENOMEM;
166 goto exit;
167 }
168
169 memset(data->data, 0xff, EEPROM_SIZE);
170 i2c_set_clientdata(client, data);
171 mutex_init(&data->update_lock);
172 data->nature = UNKNOWN;
173
174 /* Detect the Vaio nature of EEPROMs.
175 We use the "PCG-" or "VGN-" prefix as the signature. */
176 if (client->addr == 0x57
177 && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
178 char name[4];
179
180 name[0] = i2c_smbus_read_byte_data(client, 0x80);
181 name[1] = i2c_smbus_read_byte_data(client, 0x81);
182 name[2] = i2c_smbus_read_byte_data(client, 0x82);
183 name[3] = i2c_smbus_read_byte_data(client, 0x83);
184
185 if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
186 dev_info(&client->dev, "Vaio EEPROM detected, "
187 "enabling privacy protection\n");
188 data->nature = VAIO;
189 }
190 }
191
192 /* create the sysfs eeprom file */
193 err = sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr);
194 if (err)
195 goto exit_kfree;
196
197 return 0;
198
199exit_kfree:
200 kfree(data);
201exit:
202 return err;
203}
204
205static int eeprom_remove(struct i2c_client *client)
206{
207 sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
208 kfree(i2c_get_clientdata(client));
209
210 return 0;
211}
212
213static const struct i2c_device_id eeprom_id[] = {
214 { "eeprom", 0 },
215 { }
216};
217
218static struct i2c_driver eeprom_driver = {
219 .driver = {
220 .name = "eeprom",
221 },
222 .probe = eeprom_probe,
223 .remove = eeprom_remove,
224 .id_table = eeprom_id,
225
226 .class = I2C_CLASS_DDC | I2C_CLASS_SPD,
227 .detect = eeprom_detect,
228 .address_list = normal_i2c,
229};
230
231module_i2c_driver(eeprom_driver);
232
233MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
234 "Philip Edelbrock <phil@netroedge.com> and "
235 "Greg Kroah-Hartman <greg@kroah.com>");
236MODULE_DESCRIPTION("I2C EEPROM driver");
237MODULE_LICENSE("GPL");
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 <jdelvare@suse.de>
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
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/device.h>
22#include <linux/capability.h>
23#include <linux/jiffies.h>
24#include <linux/i2c.h>
25#include <linux/mutex.h>
26
27/* Addresses to scan */
28static const unsigned short normal_i2c[] = { 0x50, 0x51, 0x52, 0x53, 0x54,
29 0x55, 0x56, 0x57, I2C_CLIENT_END };
30
31
32/* Size of EEPROM in bytes */
33#define EEPROM_SIZE 256
34
35/* possible types of eeprom devices */
36enum eeprom_nature {
37 UNKNOWN,
38 VAIO,
39};
40
41/* Each client has this additional data */
42struct eeprom_data {
43 struct mutex update_lock;
44 u8 valid; /* bitfield, bit!=0 if slice is valid */
45 unsigned long last_updated[8]; /* In jiffies, 8 slices */
46 u8 data[EEPROM_SIZE]; /* Register values */
47 enum eeprom_nature nature;
48};
49
50
51static void eeprom_update_client(struct i2c_client *client, u8 slice)
52{
53 struct eeprom_data *data = i2c_get_clientdata(client);
54 int i;
55
56 mutex_lock(&data->update_lock);
57
58 if (!(data->valid & (1 << slice)) ||
59 time_after(jiffies, data->last_updated[slice] + 300 * HZ)) {
60 dev_dbg(&client->dev, "Starting eeprom update, slice %u\n", slice);
61
62 if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
63 for (i = slice << 5; i < (slice + 1) << 5; i += 32)
64 if (i2c_smbus_read_i2c_block_data(client, i,
65 32, data->data + i)
66 != 32)
67 goto exit;
68 } else {
69 for (i = slice << 5; i < (slice + 1) << 5; i += 2) {
70 int word = i2c_smbus_read_word_data(client, i);
71 if (word < 0)
72 goto exit;
73 data->data[i] = word & 0xff;
74 data->data[i + 1] = word >> 8;
75 }
76 }
77 data->last_updated[slice] = jiffies;
78 data->valid |= (1 << slice);
79 }
80exit:
81 mutex_unlock(&data->update_lock);
82}
83
84static ssize_t eeprom_read(struct file *filp, struct kobject *kobj,
85 struct bin_attribute *bin_attr,
86 char *buf, loff_t off, size_t count)
87{
88 struct i2c_client *client = to_i2c_client(kobj_to_dev(kobj));
89 struct eeprom_data *data = i2c_get_clientdata(client);
90 u8 slice;
91
92 /* Only refresh slices which contain requested bytes */
93 for (slice = off >> 5; slice <= (off + count - 1) >> 5; slice++)
94 eeprom_update_client(client, slice);
95
96 /* Hide Vaio private settings to regular users:
97 - BIOS passwords: bytes 0x00 to 0x0f
98 - UUID: bytes 0x10 to 0x1f
99 - Serial number: 0xc0 to 0xdf */
100 if (data->nature == VAIO && !capable(CAP_SYS_ADMIN)) {
101 int i;
102
103 for (i = 0; i < count; i++) {
104 if ((off + i <= 0x1f) ||
105 (off + i >= 0xc0 && off + i <= 0xdf))
106 buf[i] = 0;
107 else
108 buf[i] = data->data[off + i];
109 }
110 } else {
111 memcpy(buf, &data->data[off], count);
112 }
113
114 return count;
115}
116
117static const struct bin_attribute eeprom_attr = {
118 .attr = {
119 .name = "eeprom",
120 .mode = S_IRUGO,
121 },
122 .size = EEPROM_SIZE,
123 .read = eeprom_read,
124};
125
126/* Return 0 if detection is successful, -ENODEV otherwise */
127static int eeprom_detect(struct i2c_client *client, struct i2c_board_info *info)
128{
129 struct i2c_adapter *adapter = client->adapter;
130
131 /* EDID EEPROMs are often 24C00 EEPROMs, which answer to all
132 addresses 0x50-0x57, but we only care about 0x50. So decline
133 attaching to addresses >= 0x51 on DDC buses */
134 if (!(adapter->class & I2C_CLASS_SPD) && client->addr >= 0x51)
135 return -ENODEV;
136
137 /* There are four ways we can read the EEPROM data:
138 (1) I2C block reads (faster, but unsupported by most adapters)
139 (2) Word reads (128% overhead)
140 (3) Consecutive byte reads (88% overhead, unsafe)
141 (4) Regular byte data reads (265% overhead)
142 The third and fourth methods are not implemented by this driver
143 because all known adapters support one of the first two. */
144 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_WORD_DATA)
145 && !i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_I2C_BLOCK))
146 return -ENODEV;
147
148 strlcpy(info->type, "eeprom", I2C_NAME_SIZE);
149
150 return 0;
151}
152
153static int eeprom_probe(struct i2c_client *client,
154 const struct i2c_device_id *id)
155{
156 struct i2c_adapter *adapter = client->adapter;
157 struct eeprom_data *data;
158
159 data = devm_kzalloc(&client->dev, sizeof(struct eeprom_data),
160 GFP_KERNEL);
161 if (!data)
162 return -ENOMEM;
163
164 memset(data->data, 0xff, EEPROM_SIZE);
165 i2c_set_clientdata(client, data);
166 mutex_init(&data->update_lock);
167 data->nature = UNKNOWN;
168
169 /* Detect the Vaio nature of EEPROMs.
170 We use the "PCG-" or "VGN-" prefix as the signature. */
171 if (client->addr == 0x57
172 && i2c_check_functionality(adapter, I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
173 char name[4];
174
175 name[0] = i2c_smbus_read_byte_data(client, 0x80);
176 name[1] = i2c_smbus_read_byte_data(client, 0x81);
177 name[2] = i2c_smbus_read_byte_data(client, 0x82);
178 name[3] = i2c_smbus_read_byte_data(client, 0x83);
179
180 if (!memcmp(name, "PCG-", 4) || !memcmp(name, "VGN-", 4)) {
181 dev_info(&client->dev, "Vaio EEPROM detected, "
182 "enabling privacy protection\n");
183 data->nature = VAIO;
184 }
185 }
186
187 /* create the sysfs eeprom file */
188 return sysfs_create_bin_file(&client->dev.kobj, &eeprom_attr);
189}
190
191static int eeprom_remove(struct i2c_client *client)
192{
193 sysfs_remove_bin_file(&client->dev.kobj, &eeprom_attr);
194
195 return 0;
196}
197
198static const struct i2c_device_id eeprom_id[] = {
199 { "eeprom", 0 },
200 { }
201};
202
203static struct i2c_driver eeprom_driver = {
204 .driver = {
205 .name = "eeprom",
206 },
207 .probe = eeprom_probe,
208 .remove = eeprom_remove,
209 .id_table = eeprom_id,
210
211 .class = I2C_CLASS_DDC | I2C_CLASS_SPD,
212 .detect = eeprom_detect,
213 .address_list = normal_i2c,
214};
215
216module_i2c_driver(eeprom_driver);
217
218MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and "
219 "Philip Edelbrock <phil@netroedge.com> and "
220 "Greg Kroah-Hartman <greg@kroah.com>");
221MODULE_DESCRIPTION("I2C EEPROM driver");
222MODULE_LICENSE("GPL");