]>
Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
438d6c2c | 2 | i2c-dev.c - i2c-bus driver, char device interface |
1da177e4 LT |
3 | |
4 | Copyright (C) 1995-97 Simon G. Vogl | |
5 | Copyright (C) 1998-99 Frodo Looijaard <frodol@dds.nl> | |
6 | Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> | |
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. | |
1da177e4 LT |
17 | */ |
18 | ||
19 | /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module. | |
20 | But I have used so much of his original code and ideas that it seems | |
21 | only fair to recognize him as co-author -- Frodo */ | |
22 | ||
23 | /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */ | |
24 | ||
d6760b14 | 25 | #include <linux/cdev.h> |
9ea3e941 | 26 | #include <linux/device.h> |
1da177e4 | 27 | #include <linux/fs.h> |
1da177e4 | 28 | #include <linux/i2c-dev.h> |
a8766073 WS |
29 | #include <linux/i2c.h> |
30 | #include <linux/init.h> | |
cd97f39b | 31 | #include <linux/jiffies.h> |
a8766073 WS |
32 | #include <linux/kernel.h> |
33 | #include <linux/list.h> | |
34 | #include <linux/module.h> | |
35 | #include <linux/notifier.h> | |
36 | #include <linux/slab.h> | |
ae5624fc | 37 | #include <linux/uaccess.h> |
7d5cb456 | 38 | #include <linux/compat.h> |
1da177e4 | 39 | |
907135aa DB |
40 | /* |
41 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
42 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
43 | * with a character special file which is accessed by user mode drivers. | |
44 | * | |
45 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
9ea3e941 | 46 | * maintained by the driver model, and is updated using bus notifications. |
907135aa | 47 | */ |
1da177e4 | 48 | struct i2c_dev { |
f3b3aadb | 49 | struct list_head list; |
1da177e4 | 50 | struct i2c_adapter *adap; |
ac11d060 | 51 | struct device *dev; |
d6760b14 | 52 | struct cdev cdev; |
1da177e4 | 53 | }; |
1da177e4 | 54 | |
d6760b14 | 55 | #define I2C_MINORS MINORMASK |
f3b3aadb JD |
56 | static LIST_HEAD(i2c_dev_list); |
57 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
58 | |
59 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
60 | { | |
61 | struct i2c_dev *i2c_dev; | |
62 | ||
f3b3aadb JD |
63 | spin_lock(&i2c_dev_list_lock); |
64 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
65 | if (i2c_dev->adap->nr == index) | |
66 | goto found; | |
67 | } | |
68 | i2c_dev = NULL; | |
69 | found: | |
70 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
71 | return i2c_dev; |
72 | } | |
73 | ||
1da177e4 LT |
74 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
75 | { | |
76 | struct i2c_dev *i2c_dev; | |
77 | ||
f3b3aadb JD |
78 | if (adap->nr >= I2C_MINORS) { |
79 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
80 | adap->nr); | |
81 | return ERR_PTR(-ENODEV); | |
82 | } | |
83 | ||
5263ebb5 | 84 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
85 | if (!i2c_dev) |
86 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 87 | i2c_dev->adap = adap; |
f3b3aadb JD |
88 | |
89 | spin_lock(&i2c_dev_list_lock); | |
90 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
91 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 92 | return i2c_dev; |
1da177e4 LT |
93 | } |
94 | ||
72a71f86 | 95 | static void put_i2c_dev(struct i2c_dev *i2c_dev) |
1da177e4 | 96 | { |
f3b3aadb JD |
97 | spin_lock(&i2c_dev_list_lock); |
98 | list_del(&i2c_dev->list); | |
99 | spin_unlock(&i2c_dev_list_lock); | |
07125ab2 | 100 | kfree(i2c_dev); |
1da177e4 LT |
101 | } |
102 | ||
45f176ae GR |
103 | static ssize_t name_show(struct device *dev, |
104 | struct device_attribute *attr, char *buf) | |
1da177e4 | 105 | { |
ac11d060 | 106 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
107 | |
108 | if (!i2c_dev) | |
109 | return -ENODEV; | |
1da177e4 LT |
110 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
111 | } | |
45f176ae GR |
112 | static DEVICE_ATTR_RO(name); |
113 | ||
114 | static struct attribute *i2c_attrs[] = { | |
115 | &dev_attr_name.attr, | |
116 | NULL, | |
117 | }; | |
118 | ATTRIBUTE_GROUPS(i2c); | |
1da177e4 | 119 | |
907135aa DB |
120 | /* ------------------------------------------------------------------------- */ |
121 | ||
122 | /* | |
123 | * After opening an instance of this character special file, a file | |
124 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
125 | * | |
126 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
127 | * traffic to any devices on the bus used by that adapter. That's because | |
128 | * the i2c_msg vectors embed all the addressing information they need, and | |
129 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
130 | * don't support that interface. | |
131 | * | |
132 | * To use read()/write() system calls on that file descriptor, or to use | |
133 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
134 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
135 | * (never registered) i2c_client so it holds the addressing information | |
136 | * needed by those system calls and by this SMBus interface. | |
137 | */ | |
138 | ||
ae5624fc FH |
139 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, |
140 | loff_t *offset) | |
1da177e4 LT |
141 | { |
142 | char *tmp; | |
143 | int ret; | |
144 | ||
0be16c30 | 145 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
146 | |
147 | if (count > 8192) | |
148 | count = 8192; | |
149 | ||
ae5624fc FH |
150 | tmp = kmalloc(count, GFP_KERNEL); |
151 | if (tmp == NULL) | |
1da177e4 LT |
152 | return -ENOMEM; |
153 | ||
2ce5b34f | 154 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
496ad9aa | 155 | iminor(file_inode(file)), count); |
1da177e4 | 156 | |
ae5624fc | 157 | ret = i2c_master_recv(client, tmp, count); |
1da177e4 | 158 | if (ret >= 0) |
ae5624fc | 159 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; |
1da177e4 LT |
160 | kfree(tmp); |
161 | return ret; | |
162 | } | |
163 | ||
ae5624fc FH |
164 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, |
165 | size_t count, loff_t *offset) | |
1da177e4 LT |
166 | { |
167 | int ret; | |
168 | char *tmp; | |
0be16c30 | 169 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
170 | |
171 | if (count > 8192) | |
172 | count = 8192; | |
173 | ||
f1c2e33c JL |
174 | tmp = memdup_user(buf, count); |
175 | if (IS_ERR(tmp)) | |
176 | return PTR_ERR(tmp); | |
1da177e4 | 177 | |
2ce5b34f | 178 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
496ad9aa | 179 | iminor(file_inode(file)), count); |
1da177e4 | 180 | |
ae5624fc | 181 | ret = i2c_master_send(client, tmp, count); |
1da177e4 LT |
182 | kfree(tmp); |
183 | return ret; | |
184 | } | |
185 | ||
9b766b81 DB |
186 | static int i2cdev_check(struct device *dev, void *addrp) |
187 | { | |
188 | struct i2c_client *client = i2c_verify_client(dev); | |
189 | ||
190 | if (!client || client->addr != *(unsigned int *)addrp) | |
191 | return 0; | |
192 | ||
193 | return dev->driver ? -EBUSY : 0; | |
194 | } | |
195 | ||
0826374b ML |
196 | /* walk up mux tree */ |
197 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
198 | { | |
97cc4d49 | 199 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
200 | int result; |
201 | ||
202 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
97cc4d49 JD |
203 | if (!result && parent) |
204 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
205 | |
206 | return result; | |
207 | } | |
208 | ||
209 | /* recurse down mux tree */ | |
210 | static int i2cdev_check_mux_children(struct device *dev, void *addrp) | |
211 | { | |
212 | int result; | |
213 | ||
214 | if (dev->type == &i2c_adapter_type) | |
215 | result = device_for_each_child(dev, addrp, | |
216 | i2cdev_check_mux_children); | |
217 | else | |
218 | result = i2cdev_check(dev, addrp); | |
219 | ||
220 | return result; | |
221 | } | |
222 | ||
bd4217d8 JD |
223 | /* This address checking function differs from the one in i2c-core |
224 | in that it considers an address with a registered device, but no | |
9b766b81 | 225 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
226 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
227 | { | |
97cc4d49 | 228 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
229 | int result = 0; |
230 | ||
97cc4d49 JD |
231 | if (parent) |
232 | result = i2cdev_check_mux_parents(parent, addr); | |
0826374b ML |
233 | |
234 | if (!result) | |
235 | result = device_for_each_child(&adapter->dev, &addr, | |
236 | i2cdev_check_mux_children); | |
237 | ||
238 | return result; | |
bd4217d8 JD |
239 | } |
240 | ||
c57d3e7a | 241 | static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client, |
7d5cb456 | 242 | unsigned nmsgs, struct i2c_msg *msgs) |
1da177e4 | 243 | { |
1da177e4 | 244 | u8 __user **data_ptrs; |
dba7997a JD |
245 | int i, res; |
246 | ||
7d5cb456 | 247 | data_ptrs = kmalloc(nmsgs * sizeof(u8 __user *), GFP_KERNEL); |
dba7997a | 248 | if (data_ptrs == NULL) { |
7d5cb456 | 249 | kfree(msgs); |
dba7997a JD |
250 | return -ENOMEM; |
251 | } | |
252 | ||
253 | res = 0; | |
7d5cb456 | 254 | for (i = 0; i < nmsgs; i++) { |
838bfa60 | 255 | /* Limit the size of the message to a sane amount */ |
7d5cb456 | 256 | if (msgs[i].len > 8192) { |
dba7997a JD |
257 | res = -EINVAL; |
258 | break; | |
259 | } | |
838bfa60 | 260 | |
7d5cb456 AV |
261 | data_ptrs[i] = (u8 __user *)msgs[i].buf; |
262 | msgs[i].buf = memdup_user(data_ptrs[i], msgs[i].len); | |
263 | if (IS_ERR(msgs[i].buf)) { | |
264 | res = PTR_ERR(msgs[i].buf); | |
dba7997a JD |
265 | break; |
266 | } | |
838bfa60 JD |
267 | |
268 | /* | |
269 | * If the message length is received from the slave (similar | |
270 | * to SMBus block read), we must ensure that the buffer will | |
271 | * be large enough to cope with a message length of | |
272 | * I2C_SMBUS_BLOCK_MAX as this is the maximum underlying bus | |
273 | * drivers allow. The first byte in the buffer must be | |
274 | * pre-filled with the number of extra bytes, which must be | |
275 | * at least one to hold the message length, but can be | |
276 | * greater (for example to account for a checksum byte at | |
277 | * the end of the message.) | |
278 | */ | |
7d5cb456 AV |
279 | if (msgs[i].flags & I2C_M_RECV_LEN) { |
280 | if (!(msgs[i].flags & I2C_M_RD) || | |
281 | msgs[i].buf[0] < 1 || | |
282 | msgs[i].len < msgs[i].buf[0] + | |
838bfa60 JD |
283 | I2C_SMBUS_BLOCK_MAX) { |
284 | res = -EINVAL; | |
285 | break; | |
286 | } | |
287 | ||
7d5cb456 | 288 | msgs[i].len = msgs[i].buf[0]; |
838bfa60 | 289 | } |
dba7997a JD |
290 | } |
291 | if (res < 0) { | |
292 | int j; | |
293 | for (j = 0; j < i; ++j) | |
7d5cb456 | 294 | kfree(msgs[j].buf); |
dba7997a | 295 | kfree(data_ptrs); |
7d5cb456 | 296 | kfree(msgs); |
dba7997a JD |
297 | return res; |
298 | } | |
299 | ||
7d5cb456 | 300 | res = i2c_transfer(client->adapter, msgs, nmsgs); |
dba7997a | 301 | while (i-- > 0) { |
7d5cb456 AV |
302 | if (res >= 0 && (msgs[i].flags & I2C_M_RD)) { |
303 | if (copy_to_user(data_ptrs[i], msgs[i].buf, | |
304 | msgs[i].len)) | |
dba7997a JD |
305 | res = -EFAULT; |
306 | } | |
7d5cb456 | 307 | kfree(msgs[i].buf); |
dba7997a JD |
308 | } |
309 | kfree(data_ptrs); | |
7d5cb456 | 310 | kfree(msgs); |
dba7997a JD |
311 | return res; |
312 | } | |
313 | ||
314 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
7d5cb456 AV |
315 | u8 read_write, u8 command, u32 size, |
316 | union i2c_smbus_data __user *data) | |
dba7997a | 317 | { |
30f939fe | 318 | union i2c_smbus_data temp = {}; |
dba7997a JD |
319 | int datasize, res; |
320 | ||
7d5cb456 AV |
321 | if ((size != I2C_SMBUS_BYTE) && |
322 | (size != I2C_SMBUS_QUICK) && | |
323 | (size != I2C_SMBUS_BYTE_DATA) && | |
324 | (size != I2C_SMBUS_WORD_DATA) && | |
325 | (size != I2C_SMBUS_PROC_CALL) && | |
326 | (size != I2C_SMBUS_BLOCK_DATA) && | |
327 | (size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
328 | (size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
329 | (size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
dba7997a JD |
330 | dev_dbg(&client->adapter->dev, |
331 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
7d5cb456 | 332 | size); |
dba7997a JD |
333 | return -EINVAL; |
334 | } | |
335 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
336 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
7d5cb456 AV |
337 | if ((read_write != I2C_SMBUS_READ) && |
338 | (read_write != I2C_SMBUS_WRITE)) { | |
dba7997a JD |
339 | dev_dbg(&client->adapter->dev, |
340 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
7d5cb456 | 341 | read_write); |
dba7997a JD |
342 | return -EINVAL; |
343 | } | |
344 | ||
345 | /* Note that command values are always valid! */ | |
346 | ||
7d5cb456 AV |
347 | if ((size == I2C_SMBUS_QUICK) || |
348 | ((size == I2C_SMBUS_BYTE) && | |
349 | (read_write == I2C_SMBUS_WRITE))) | |
dba7997a JD |
350 | /* These are special: we do not use data */ |
351 | return i2c_smbus_xfer(client->adapter, client->addr, | |
7d5cb456 AV |
352 | client->flags, read_write, |
353 | command, size, NULL); | |
dba7997a | 354 | |
7d5cb456 | 355 | if (data == NULL) { |
dba7997a JD |
356 | dev_dbg(&client->adapter->dev, |
357 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
358 | return -EINVAL; | |
359 | } | |
360 | ||
7d5cb456 AV |
361 | if ((size == I2C_SMBUS_BYTE_DATA) || |
362 | (size == I2C_SMBUS_BYTE)) | |
363 | datasize = sizeof(data->byte); | |
364 | else if ((size == I2C_SMBUS_WORD_DATA) || | |
365 | (size == I2C_SMBUS_PROC_CALL)) | |
366 | datasize = sizeof(data->word); | |
dba7997a | 367 | else /* size == smbus block, i2c block, or block proc. call */ |
7d5cb456 | 368 | datasize = sizeof(data->block); |
dba7997a | 369 | |
7d5cb456 AV |
370 | if ((size == I2C_SMBUS_PROC_CALL) || |
371 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
372 | (size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
373 | (read_write == I2C_SMBUS_WRITE)) { | |
374 | if (copy_from_user(&temp, data, datasize)) | |
dba7997a JD |
375 | return -EFAULT; |
376 | } | |
7d5cb456 | 377 | if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) { |
dba7997a JD |
378 | /* Convert old I2C block commands to the new |
379 | convention. This preserves binary compatibility. */ | |
7d5cb456 AV |
380 | size = I2C_SMBUS_I2C_BLOCK_DATA; |
381 | if (read_write == I2C_SMBUS_READ) | |
dba7997a JD |
382 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; |
383 | } | |
384 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
7d5cb456 AV |
385 | read_write, command, size, &temp); |
386 | if (!res && ((size == I2C_SMBUS_PROC_CALL) || | |
387 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
388 | (read_write == I2C_SMBUS_READ))) { | |
389 | if (copy_to_user(data, &temp, datasize)) | |
dba7997a JD |
390 | return -EFAULT; |
391 | } | |
392 | return res; | |
393 | } | |
394 | ||
77e38bff | 395 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a | 396 | { |
0be16c30 | 397 | struct i2c_client *client = file->private_data; |
1da177e4 LT |
398 | unsigned long funcs; |
399 | ||
e8aafcb2 JD |
400 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
401 | cmd, arg); | |
1da177e4 | 402 | |
ae5624fc | 403 | switch (cmd) { |
1da177e4 LT |
404 | case I2C_SLAVE: |
405 | case I2C_SLAVE_FORCE: | |
438d6c2c | 406 | if ((arg > 0x3ff) || |
1da177e4 LT |
407 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
408 | return -EINVAL; | |
bd4217d8 | 409 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 410 | return -EBUSY; |
bd4217d8 | 411 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
412 | client->addr = arg; |
413 | return 0; | |
414 | case I2C_TENBIT: | |
415 | if (arg) | |
416 | client->flags |= I2C_M_TEN; | |
417 | else | |
418 | client->flags &= ~I2C_M_TEN; | |
419 | return 0; | |
420 | case I2C_PEC: | |
9e685c84 JD |
421 | /* |
422 | * Setting the PEC flag here won't affect kernel drivers, | |
423 | * which will be using the i2c_client node registered with | |
424 | * the driver model core. Likewise, when that client has | |
425 | * the PEC flag already set, the i2c-dev driver won't see | |
426 | * (or use) this setting. | |
427 | */ | |
1da177e4 LT |
428 | if (arg) |
429 | client->flags |= I2C_CLIENT_PEC; | |
430 | else | |
431 | client->flags &= ~I2C_CLIENT_PEC; | |
432 | return 0; | |
433 | case I2C_FUNCS: | |
434 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 435 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 | 436 | |
7d5cb456 AV |
437 | case I2C_RDWR: { |
438 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
439 | struct i2c_msg *rdwr_pa; | |
440 | ||
441 | if (copy_from_user(&rdwr_arg, | |
442 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
443 | sizeof(rdwr_arg))) | |
444 | return -EFAULT; | |
445 | ||
446 | /* Put an arbitrary limit on the number of messages that can | |
447 | * be sent at once */ | |
448 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) | |
449 | return -EINVAL; | |
1da177e4 | 450 | |
7d5cb456 AV |
451 | rdwr_pa = memdup_user(rdwr_arg.msgs, |
452 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
453 | if (IS_ERR(rdwr_pa)) | |
454 | return PTR_ERR(rdwr_pa); | |
455 | ||
456 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
457 | } | |
1da177e4 | 458 | |
7d5cb456 AV |
459 | case I2C_SMBUS: { |
460 | struct i2c_smbus_ioctl_data data_arg; | |
461 | if (copy_from_user(&data_arg, | |
462 | (struct i2c_smbus_ioctl_data __user *) arg, | |
463 | sizeof(struct i2c_smbus_ioctl_data))) | |
464 | return -EFAULT; | |
465 | return i2cdev_ioctl_smbus(client, data_arg.read_write, | |
466 | data_arg.command, | |
467 | data_arg.size, | |
468 | data_arg.data); | |
469 | } | |
53be7959 DB |
470 | case I2C_RETRIES: |
471 | client->adapter->retries = arg; | |
472 | break; | |
473 | case I2C_TIMEOUT: | |
cd97f39b JD |
474 | /* For historical reasons, user-space sets the timeout |
475 | * value in units of 10 ms. | |
476 | */ | |
477 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
53be7959 | 478 | break; |
1da177e4 | 479 | default: |
53be7959 DB |
480 | /* NOTE: returning a fault code here could cause trouble |
481 | * in buggy userspace code. Some old kernel bugs returned | |
482 | * zero in this case, and userspace code might accidentally | |
483 | * have depended on that bug. | |
484 | */ | |
485 | return -ENOTTY; | |
1da177e4 LT |
486 | } |
487 | return 0; | |
488 | } | |
489 | ||
7d5cb456 AV |
490 | #ifdef CONFIG_COMPAT |
491 | ||
492 | struct i2c_smbus_ioctl_data32 { | |
493 | u8 read_write; | |
494 | u8 command; | |
495 | u32 size; | |
496 | compat_caddr_t data; /* union i2c_smbus_data *data */ | |
497 | }; | |
498 | ||
499 | struct i2c_msg32 { | |
500 | u16 addr; | |
501 | u16 flags; | |
502 | u16 len; | |
503 | compat_caddr_t buf; | |
504 | }; | |
505 | ||
506 | struct i2c_rdwr_ioctl_data32 { | |
507 | compat_caddr_t msgs; /* struct i2c_msg __user *msgs */ | |
508 | u32 nmsgs; | |
509 | }; | |
510 | ||
511 | static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
512 | { | |
513 | struct i2c_client *client = file->private_data; | |
514 | unsigned long funcs; | |
515 | switch (cmd) { | |
516 | case I2C_FUNCS: | |
517 | funcs = i2c_get_functionality(client->adapter); | |
518 | return put_user(funcs, (compat_ulong_t __user *)arg); | |
519 | case I2C_RDWR: { | |
520 | struct i2c_rdwr_ioctl_data32 rdwr_arg; | |
521 | struct i2c_msg32 *p; | |
522 | struct i2c_msg *rdwr_pa; | |
523 | int i; | |
524 | ||
525 | if (copy_from_user(&rdwr_arg, | |
526 | (struct i2c_rdwr_ioctl_data32 __user *)arg, | |
527 | sizeof(rdwr_arg))) | |
528 | return -EFAULT; | |
529 | ||
530 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) | |
531 | return -EINVAL; | |
532 | ||
533 | rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg), | |
534 | GFP_KERNEL); | |
535 | if (!rdwr_pa) | |
536 | return -ENOMEM; | |
537 | ||
538 | p = compat_ptr(rdwr_arg.msgs); | |
539 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
540 | struct i2c_msg32 umsg; | |
541 | if (copy_from_user(&umsg, p + i, sizeof(umsg))) { | |
542 | kfree(rdwr_pa); | |
543 | return -EFAULT; | |
544 | } | |
545 | rdwr_pa[i] = (struct i2c_msg) { | |
546 | .addr = umsg.addr, | |
547 | .flags = umsg.flags, | |
548 | .len = umsg.len, | |
549 | .buf = compat_ptr(umsg.buf) | |
550 | }; | |
551 | } | |
552 | ||
553 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
554 | } | |
555 | case I2C_SMBUS: { | |
556 | struct i2c_smbus_ioctl_data32 data32; | |
557 | if (copy_from_user(&data32, | |
558 | (void __user *) arg, | |
559 | sizeof(data32))) | |
560 | return -EFAULT; | |
561 | return i2cdev_ioctl_smbus(client, data32.read_write, | |
562 | data32.command, | |
563 | data32.size, | |
564 | compat_ptr(data32.data)); | |
565 | } | |
566 | default: | |
567 | return i2cdev_ioctl(file, cmd, arg); | |
568 | } | |
569 | } | |
570 | #else | |
571 | #define compat_i2cdev_ioctl NULL | |
572 | #endif | |
573 | ||
1da177e4 LT |
574 | static int i2cdev_open(struct inode *inode, struct file *file) |
575 | { | |
576 | unsigned int minor = iminor(inode); | |
577 | struct i2c_client *client; | |
578 | struct i2c_adapter *adap; | |
1da177e4 | 579 | |
5136ed4f | 580 | adap = i2c_get_adapter(minor); |
9669f541 VS |
581 | if (!adap) |
582 | return -ENODEV; | |
1da177e4 | 583 | |
907135aa DB |
584 | /* This creates an anonymous i2c_client, which may later be |
585 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
586 | * | |
587 | * This client is ** NEVER REGISTERED ** with the driver model | |
588 | * or I2C core code!! It just holds private copies of addressing | |
589 | * information and maybe a PEC flag. | |
590 | */ | |
22f76e74 | 591 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
592 | if (!client) { |
593 | i2c_put_adapter(adap); | |
9669f541 | 594 | return -ENOMEM; |
1da177e4 | 595 | } |
22f76e74 | 596 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
1da177e4 | 597 | |
1da177e4 LT |
598 | client->adapter = adap; |
599 | file->private_data = client; | |
600 | ||
9669f541 | 601 | return 0; |
1da177e4 LT |
602 | } |
603 | ||
604 | static int i2cdev_release(struct inode *inode, struct file *file) | |
605 | { | |
606 | struct i2c_client *client = file->private_data; | |
607 | ||
608 | i2c_put_adapter(client->adapter); | |
609 | kfree(client); | |
610 | file->private_data = NULL; | |
611 | ||
612 | return 0; | |
613 | } | |
614 | ||
2b8693c0 | 615 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
616 | .owner = THIS_MODULE, |
617 | .llseek = no_llseek, | |
618 | .read = i2cdev_read, | |
619 | .write = i2cdev_write, | |
77e38bff | 620 | .unlocked_ioctl = i2cdev_ioctl, |
7d5cb456 | 621 | .compat_ioctl = compat_i2cdev_ioctl, |
1da177e4 LT |
622 | .open = i2cdev_open, |
623 | .release = i2cdev_release, | |
624 | }; | |
625 | ||
907135aa DB |
626 | /* ------------------------------------------------------------------------- */ |
627 | ||
79472132 | 628 | static struct class *i2c_dev_class; |
1da177e4 | 629 | |
9ea3e941 | 630 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) |
1da177e4 | 631 | { |
9ea3e941 | 632 | struct i2c_adapter *adap; |
1da177e4 | 633 | struct i2c_dev *i2c_dev; |
defcb46e | 634 | int res; |
1da177e4 | 635 | |
9ea3e941 JD |
636 | if (dev->type != &i2c_adapter_type) |
637 | return 0; | |
638 | adap = to_i2c_adapter(dev); | |
639 | ||
1da177e4 LT |
640 | i2c_dev = get_free_i2c_dev(adap); |
641 | if (IS_ERR(i2c_dev)) | |
642 | return PTR_ERR(i2c_dev); | |
643 | ||
d6760b14 EN |
644 | cdev_init(&i2c_dev->cdev, &i2cdev_fops); |
645 | i2c_dev->cdev.owner = THIS_MODULE; | |
646 | res = cdev_add(&i2c_dev->cdev, MKDEV(I2C_MAJOR, adap->nr), 1); | |
647 | if (res) | |
648 | goto error_cdev; | |
649 | ||
1da177e4 | 650 | /* register this i2c device with the driver core */ |
a9b12619 GKH |
651 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, |
652 | MKDEV(I2C_MAJOR, adap->nr), NULL, | |
653 | "i2c-%d", adap->nr); | |
3bacb36d AM |
654 | if (IS_ERR(i2c_dev->dev)) { |
655 | res = PTR_ERR(i2c_dev->dev); | |
1da177e4 | 656 | goto error; |
defcb46e | 657 | } |
b32d20dc JD |
658 | |
659 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
660 | adap->name, adap->nr); | |
1da177e4 LT |
661 | return 0; |
662 | error: | |
d6760b14 EN |
663 | cdev_del(&i2c_dev->cdev); |
664 | error_cdev: | |
72a71f86 | 665 | put_i2c_dev(i2c_dev); |
defcb46e | 666 | return res; |
1da177e4 LT |
667 | } |
668 | ||
9ea3e941 | 669 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) |
1da177e4 | 670 | { |
9ea3e941 | 671 | struct i2c_adapter *adap; |
1da177e4 LT |
672 | struct i2c_dev *i2c_dev; |
673 | ||
9ea3e941 JD |
674 | if (dev->type != &i2c_adapter_type) |
675 | return 0; | |
676 | adap = to_i2c_adapter(dev); | |
677 | ||
9455e4c9 | 678 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
679 | if (!i2c_dev) /* attach_adapter must have failed */ |
680 | return 0; | |
1da177e4 | 681 | |
e6be18f6 | 682 | cdev_del(&i2c_dev->cdev); |
72a71f86 | 683 | put_i2c_dev(i2c_dev); |
ac11d060 | 684 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 685 | |
b6d7b3d1 | 686 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
687 | return 0; |
688 | } | |
689 | ||
eff245c8 | 690 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, |
9ea3e941 JD |
691 | void *data) |
692 | { | |
693 | struct device *dev = data; | |
694 | ||
695 | switch (action) { | |
696 | case BUS_NOTIFY_ADD_DEVICE: | |
697 | return i2cdev_attach_adapter(dev, NULL); | |
698 | case BUS_NOTIFY_DEL_DEVICE: | |
699 | return i2cdev_detach_adapter(dev, NULL); | |
700 | } | |
701 | ||
702 | return 0; | |
703 | } | |
704 | ||
705 | static struct notifier_block i2cdev_notifier = { | |
706 | .notifier_call = i2cdev_notifier_call, | |
1da177e4 LT |
707 | }; |
708 | ||
907135aa DB |
709 | /* ------------------------------------------------------------------------- */ |
710 | ||
711 | /* | |
712 | * module load/unload record keeping | |
713 | */ | |
714 | ||
1da177e4 LT |
715 | static int __init i2c_dev_init(void) |
716 | { | |
717 | int res; | |
718 | ||
719 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
720 | ||
d6760b14 | 721 | res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c"); |
1da177e4 LT |
722 | if (res) |
723 | goto out; | |
724 | ||
79472132 | 725 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
726 | if (IS_ERR(i2c_dev_class)) { |
727 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 728 | goto out_unreg_chrdev; |
e74783ec | 729 | } |
45f176ae | 730 | i2c_dev_class->dev_groups = i2c_groups; |
1da177e4 | 731 | |
9ea3e941 JD |
732 | /* Keep track of adapters which will be added or removed later */ |
733 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
1da177e4 LT |
734 | if (res) |
735 | goto out_unreg_class; | |
736 | ||
9ea3e941 JD |
737 | /* Bind to already existing adapters right away */ |
738 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
739 | ||
1da177e4 LT |
740 | return 0; |
741 | ||
742 | out_unreg_class: | |
79472132 | 743 | class_destroy(i2c_dev_class); |
1da177e4 | 744 | out_unreg_chrdev: |
d6760b14 | 745 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 LT |
746 | out: |
747 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
748 | return res; | |
749 | } | |
750 | ||
751 | static void __exit i2c_dev_exit(void) | |
752 | { | |
9ea3e941 JD |
753 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); |
754 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
79472132 | 755 | class_destroy(i2c_dev_class); |
d6760b14 | 756 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); |
1da177e4 LT |
757 | } |
758 | ||
759 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
760 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
761 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
762 | MODULE_LICENSE("GPL"); | |
763 | ||
764 | module_init(i2c_dev_init); | |
765 | module_exit(i2c_dev_exit); |