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. | |
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 | /* Note that this is a complete rewrite of Simon Vogl's i2c-dev module. | |
24 | But I have used so much of his original code and ideas that it seems | |
25 | only fair to recognize him as co-author -- Frodo */ | |
26 | ||
27 | /* The I2C_RDWR ioctl code is written by Kolja Waschk <waschk@telos.de> */ | |
28 | ||
1da177e4 LT |
29 | #include <linux/kernel.h> |
30 | #include <linux/module.h> | |
31 | #include <linux/fs.h> | |
32 | #include <linux/slab.h> | |
1da177e4 | 33 | #include <linux/init.h> |
f3b3aadb | 34 | #include <linux/list.h> |
1da177e4 LT |
35 | #include <linux/i2c.h> |
36 | #include <linux/i2c-dev.h> | |
3db633ee | 37 | #include <linux/smp_lock.h> |
1da177e4 LT |
38 | #include <asm/uaccess.h> |
39 | ||
22f76e74 | 40 | static struct i2c_driver i2cdev_driver; |
1da177e4 | 41 | |
907135aa DB |
42 | /* |
43 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
44 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
45 | * with a character special file which is accessed by user mode drivers. | |
46 | * | |
47 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
48 | * maintained by the driver model, and is updated using notifications | |
49 | * delivered to the i2cdev_driver. | |
50 | */ | |
1da177e4 | 51 | struct i2c_dev { |
f3b3aadb | 52 | struct list_head list; |
1da177e4 | 53 | struct i2c_adapter *adap; |
ac11d060 | 54 | struct device *dev; |
1da177e4 | 55 | }; |
1da177e4 LT |
56 | |
57 | #define I2C_MINORS 256 | |
f3b3aadb JD |
58 | static LIST_HEAD(i2c_dev_list); |
59 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
60 | |
61 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
62 | { | |
63 | struct i2c_dev *i2c_dev; | |
64 | ||
f3b3aadb JD |
65 | spin_lock(&i2c_dev_list_lock); |
66 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
67 | if (i2c_dev->adap->nr == index) | |
68 | goto found; | |
69 | } | |
70 | i2c_dev = NULL; | |
71 | found: | |
72 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
73 | return i2c_dev; |
74 | } | |
75 | ||
1da177e4 LT |
76 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
77 | { | |
78 | struct i2c_dev *i2c_dev; | |
79 | ||
f3b3aadb JD |
80 | if (adap->nr >= I2C_MINORS) { |
81 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
82 | adap->nr); | |
83 | return ERR_PTR(-ENODEV); | |
84 | } | |
85 | ||
5263ebb5 | 86 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
87 | if (!i2c_dev) |
88 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 89 | i2c_dev->adap = adap; |
f3b3aadb JD |
90 | |
91 | spin_lock(&i2c_dev_list_lock); | |
92 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
93 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 94 | return i2c_dev; |
1da177e4 LT |
95 | } |
96 | ||
97 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
98 | { | |
f3b3aadb JD |
99 | spin_lock(&i2c_dev_list_lock); |
100 | list_del(&i2c_dev->list); | |
101 | spin_unlock(&i2c_dev_list_lock); | |
07125ab2 | 102 | kfree(i2c_dev); |
1da177e4 LT |
103 | } |
104 | ||
ac11d060 GKH |
105 | static ssize_t show_adapter_name(struct device *dev, |
106 | struct device_attribute *attr, char *buf) | |
1da177e4 | 107 | { |
ac11d060 | 108 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
109 | |
110 | if (!i2c_dev) | |
111 | return -ENODEV; | |
1da177e4 LT |
112 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
113 | } | |
ac11d060 | 114 | static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); |
1da177e4 | 115 | |
907135aa DB |
116 | /* ------------------------------------------------------------------------- */ |
117 | ||
118 | /* | |
119 | * After opening an instance of this character special file, a file | |
120 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
121 | * | |
122 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
123 | * traffic to any devices on the bus used by that adapter. That's because | |
124 | * the i2c_msg vectors embed all the addressing information they need, and | |
125 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
126 | * don't support that interface. | |
127 | * | |
128 | * To use read()/write() system calls on that file descriptor, or to use | |
129 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
130 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
131 | * (never registered) i2c_client so it holds the addressing information | |
132 | * needed by those system calls and by this SMBus interface. | |
133 | */ | |
134 | ||
1da177e4 LT |
135 | static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count, |
136 | loff_t *offset) | |
137 | { | |
138 | char *tmp; | |
139 | int ret; | |
140 | ||
141 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
142 | ||
143 | if (count > 8192) | |
144 | count = 8192; | |
145 | ||
146 | tmp = kmalloc(count,GFP_KERNEL); | |
147 | if (tmp==NULL) | |
148 | return -ENOMEM; | |
149 | ||
2ce5b34f | 150 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", |
cba0a128 | 151 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 LT |
152 | |
153 | ret = i2c_master_recv(client,tmp,count); | |
154 | if (ret >= 0) | |
155 | ret = copy_to_user(buf,tmp,count)?-EFAULT:ret; | |
156 | kfree(tmp); | |
157 | return ret; | |
158 | } | |
159 | ||
160 | static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count, | |
161 | loff_t *offset) | |
162 | { | |
163 | int ret; | |
164 | char *tmp; | |
165 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
166 | ||
167 | if (count > 8192) | |
168 | count = 8192; | |
169 | ||
170 | tmp = kmalloc(count,GFP_KERNEL); | |
171 | if (tmp==NULL) | |
172 | return -ENOMEM; | |
173 | if (copy_from_user(tmp,buf,count)) { | |
174 | kfree(tmp); | |
175 | return -EFAULT; | |
176 | } | |
177 | ||
2ce5b34f | 178 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", |
cba0a128 | 179 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 LT |
180 | |
181 | ret = i2c_master_send(client,tmp,count); | |
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 | ||
bd4217d8 JD |
196 | /* This address checking function differs from the one in i2c-core |
197 | in that it considers an address with a registered device, but no | |
9b766b81 | 198 | driver bound to it, as NOT busy. */ |
bd4217d8 JD |
199 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
200 | { | |
9b766b81 | 201 | return device_for_each_child(&adapter->dev, &addr, i2cdev_check); |
bd4217d8 JD |
202 | } |
203 | ||
dba7997a JD |
204 | static noinline int i2cdev_ioctl_rdrw(struct i2c_client *client, |
205 | unsigned long arg) | |
1da177e4 | 206 | { |
1da177e4 | 207 | struct i2c_rdwr_ioctl_data rdwr_arg; |
1da177e4 LT |
208 | struct i2c_msg *rdwr_pa; |
209 | u8 __user **data_ptrs; | |
dba7997a JD |
210 | int i, res; |
211 | ||
212 | if (copy_from_user(&rdwr_arg, | |
213 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
214 | sizeof(rdwr_arg))) | |
215 | return -EFAULT; | |
216 | ||
217 | /* Put an arbitrary limit on the number of messages that can | |
218 | * be sent at once */ | |
219 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
220 | return -EINVAL; | |
221 | ||
222 | rdwr_pa = (struct i2c_msg *) | |
223 | kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), | |
224 | GFP_KERNEL); | |
225 | if (!rdwr_pa) | |
226 | return -ENOMEM; | |
227 | ||
228 | if (copy_from_user(rdwr_pa, rdwr_arg.msgs, | |
229 | rdwr_arg.nmsgs * sizeof(struct i2c_msg))) { | |
230 | kfree(rdwr_pa); | |
231 | return -EFAULT; | |
232 | } | |
233 | ||
234 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
235 | if (data_ptrs == NULL) { | |
236 | kfree(rdwr_pa); | |
237 | return -ENOMEM; | |
238 | } | |
239 | ||
240 | res = 0; | |
241 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
242 | /* Limit the size of the message to a sane amount; | |
243 | * and don't let length change either. */ | |
244 | if ((rdwr_pa[i].len > 8192) || | |
245 | (rdwr_pa[i].flags & I2C_M_RECV_LEN)) { | |
246 | res = -EINVAL; | |
247 | break; | |
248 | } | |
249 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; | |
250 | rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); | |
251 | if (rdwr_pa[i].buf == NULL) { | |
252 | res = -ENOMEM; | |
253 | break; | |
254 | } | |
255 | if (copy_from_user(rdwr_pa[i].buf, data_ptrs[i], | |
256 | rdwr_pa[i].len)) { | |
257 | ++i; /* Needs to be kfreed too */ | |
258 | res = -EFAULT; | |
259 | break; | |
260 | } | |
261 | } | |
262 | if (res < 0) { | |
263 | int j; | |
264 | for (j = 0; j < i; ++j) | |
265 | kfree(rdwr_pa[j].buf); | |
266 | kfree(data_ptrs); | |
267 | kfree(rdwr_pa); | |
268 | return res; | |
269 | } | |
270 | ||
271 | res = i2c_transfer(client->adapter, rdwr_pa, rdwr_arg.nmsgs); | |
272 | while (i-- > 0) { | |
273 | if (res >= 0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
274 | if (copy_to_user(data_ptrs[i], rdwr_pa[i].buf, | |
275 | rdwr_pa[i].len)) | |
276 | res = -EFAULT; | |
277 | } | |
278 | kfree(rdwr_pa[i].buf); | |
279 | } | |
280 | kfree(data_ptrs); | |
281 | kfree(rdwr_pa); | |
282 | return res; | |
283 | } | |
284 | ||
285 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
286 | unsigned long arg) | |
287 | { | |
288 | struct i2c_smbus_ioctl_data data_arg; | |
289 | union i2c_smbus_data temp; | |
290 | int datasize, res; | |
291 | ||
292 | if (copy_from_user(&data_arg, | |
293 | (struct i2c_smbus_ioctl_data __user *) arg, | |
294 | sizeof(struct i2c_smbus_ioctl_data))) | |
295 | return -EFAULT; | |
296 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
297 | (data_arg.size != I2C_SMBUS_QUICK) && | |
298 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
299 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
300 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
301 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
302 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
303 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
304 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
305 | dev_dbg(&client->adapter->dev, | |
306 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
307 | data_arg.size); | |
308 | return -EINVAL; | |
309 | } | |
310 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
311 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
312 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
313 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
314 | dev_dbg(&client->adapter->dev, | |
315 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
316 | data_arg.read_write); | |
317 | return -EINVAL; | |
318 | } | |
319 | ||
320 | /* Note that command values are always valid! */ | |
321 | ||
322 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
323 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
324 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
325 | /* These are special: we do not use data */ | |
326 | return i2c_smbus_xfer(client->adapter, client->addr, | |
327 | client->flags, data_arg.read_write, | |
328 | data_arg.command, data_arg.size, NULL); | |
329 | ||
330 | if (data_arg.data == NULL) { | |
331 | dev_dbg(&client->adapter->dev, | |
332 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
333 | return -EINVAL; | |
334 | } | |
335 | ||
336 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
337 | (data_arg.size == I2C_SMBUS_BYTE)) | |
338 | datasize = sizeof(data_arg.data->byte); | |
339 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
340 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
341 | datasize = sizeof(data_arg.data->word); | |
342 | else /* size == smbus block, i2c block, or block proc. call */ | |
343 | datasize = sizeof(data_arg.data->block); | |
344 | ||
345 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
346 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
347 | (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
348 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
349 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
350 | return -EFAULT; | |
351 | } | |
352 | if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) { | |
353 | /* Convert old I2C block commands to the new | |
354 | convention. This preserves binary compatibility. */ | |
355 | data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA; | |
356 | if (data_arg.read_write == I2C_SMBUS_READ) | |
357 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
358 | } | |
359 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
360 | data_arg.read_write, data_arg.command, data_arg.size, &temp); | |
361 | if (!res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
362 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
363 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
364 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
365 | return -EFAULT; | |
366 | } | |
367 | return res; | |
368 | } | |
369 | ||
77e38bff | 370 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) |
dba7997a JD |
371 | { |
372 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
1da177e4 LT |
373 | unsigned long funcs; |
374 | ||
e8aafcb2 JD |
375 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
376 | cmd, arg); | |
1da177e4 LT |
377 | |
378 | switch ( cmd ) { | |
379 | case I2C_SLAVE: | |
380 | case I2C_SLAVE_FORCE: | |
907135aa DB |
381 | /* NOTE: devices set up to work with "new style" drivers |
382 | * can't use I2C_SLAVE, even when the device node is not | |
383 | * bound to a driver. Only I2C_SLAVE_FORCE will work. | |
384 | * | |
385 | * Setting the PEC flag here won't affect kernel drivers, | |
386 | * which will be using the i2c_client node registered with | |
387 | * the driver model core. Likewise, when that client has | |
388 | * the PEC flag already set, the i2c-dev driver won't see | |
389 | * (or use) this setting. | |
390 | */ | |
438d6c2c | 391 | if ((arg > 0x3ff) || |
1da177e4 LT |
392 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
393 | return -EINVAL; | |
bd4217d8 | 394 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 395 | return -EBUSY; |
bd4217d8 | 396 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
397 | client->addr = arg; |
398 | return 0; | |
399 | case I2C_TENBIT: | |
400 | if (arg) | |
401 | client->flags |= I2C_M_TEN; | |
402 | else | |
403 | client->flags &= ~I2C_M_TEN; | |
404 | return 0; | |
405 | case I2C_PEC: | |
406 | if (arg) | |
407 | client->flags |= I2C_CLIENT_PEC; | |
408 | else | |
409 | client->flags &= ~I2C_CLIENT_PEC; | |
410 | return 0; | |
411 | case I2C_FUNCS: | |
412 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 413 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 LT |
414 | |
415 | case I2C_RDWR: | |
dba7997a | 416 | return i2cdev_ioctl_rdrw(client, arg); |
1da177e4 LT |
417 | |
418 | case I2C_SMBUS: | |
dba7997a | 419 | return i2cdev_ioctl_smbus(client, arg); |
1da177e4 | 420 | |
53be7959 DB |
421 | case I2C_RETRIES: |
422 | client->adapter->retries = arg; | |
423 | break; | |
424 | case I2C_TIMEOUT: | |
425 | client->adapter->timeout = arg; | |
426 | break; | |
1da177e4 | 427 | default: |
53be7959 DB |
428 | /* NOTE: returning a fault code here could cause trouble |
429 | * in buggy userspace code. Some old kernel bugs returned | |
430 | * zero in this case, and userspace code might accidentally | |
431 | * have depended on that bug. | |
432 | */ | |
433 | return -ENOTTY; | |
1da177e4 LT |
434 | } |
435 | return 0; | |
436 | } | |
437 | ||
438 | static int i2cdev_open(struct inode *inode, struct file *file) | |
439 | { | |
440 | unsigned int minor = iminor(inode); | |
441 | struct i2c_client *client; | |
442 | struct i2c_adapter *adap; | |
443 | struct i2c_dev *i2c_dev; | |
3db633ee | 444 | int ret = 0; |
1da177e4 | 445 | |
3db633ee | 446 | lock_kernel(); |
1da177e4 | 447 | i2c_dev = i2c_dev_get_by_minor(minor); |
3db633ee JC |
448 | if (!i2c_dev) { |
449 | ret = -ENODEV; | |
450 | goto out; | |
451 | } | |
1da177e4 LT |
452 | |
453 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
3db633ee JC |
454 | if (!adap) { |
455 | ret = -ENODEV; | |
456 | goto out; | |
457 | } | |
1da177e4 | 458 | |
907135aa DB |
459 | /* This creates an anonymous i2c_client, which may later be |
460 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
461 | * | |
462 | * This client is ** NEVER REGISTERED ** with the driver model | |
463 | * or I2C core code!! It just holds private copies of addressing | |
464 | * information and maybe a PEC flag. | |
465 | */ | |
22f76e74 | 466 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
467 | if (!client) { |
468 | i2c_put_adapter(adap); | |
3db633ee JC |
469 | ret = -ENOMEM; |
470 | goto out; | |
1da177e4 | 471 | } |
22f76e74 JD |
472 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
473 | client->driver = &i2cdev_driver; | |
1da177e4 | 474 | |
1da177e4 LT |
475 | client->adapter = adap; |
476 | file->private_data = client; | |
477 | ||
3db633ee JC |
478 | out: |
479 | unlock_kernel(); | |
480 | return ret; | |
1da177e4 LT |
481 | } |
482 | ||
483 | static int i2cdev_release(struct inode *inode, struct file *file) | |
484 | { | |
485 | struct i2c_client *client = file->private_data; | |
486 | ||
487 | i2c_put_adapter(client->adapter); | |
488 | kfree(client); | |
489 | file->private_data = NULL; | |
490 | ||
491 | return 0; | |
492 | } | |
493 | ||
2b8693c0 | 494 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
495 | .owner = THIS_MODULE, |
496 | .llseek = no_llseek, | |
497 | .read = i2cdev_read, | |
498 | .write = i2cdev_write, | |
77e38bff | 499 | .unlocked_ioctl = i2cdev_ioctl, |
1da177e4 LT |
500 | .open = i2cdev_open, |
501 | .release = i2cdev_release, | |
502 | }; | |
503 | ||
907135aa DB |
504 | /* ------------------------------------------------------------------------- */ |
505 | ||
506 | /* | |
507 | * The legacy "i2cdev_driver" is used primarily to get notifications when | |
508 | * I2C adapters are added or removed, so that each one gets an i2c_dev | |
509 | * and is thus made available to userspace driver code. | |
510 | */ | |
511 | ||
79472132 | 512 | static struct class *i2c_dev_class; |
1da177e4 LT |
513 | |
514 | static int i2cdev_attach_adapter(struct i2c_adapter *adap) | |
515 | { | |
516 | struct i2c_dev *i2c_dev; | |
defcb46e | 517 | int res; |
1da177e4 LT |
518 | |
519 | i2c_dev = get_free_i2c_dev(adap); | |
520 | if (IS_ERR(i2c_dev)) | |
521 | return PTR_ERR(i2c_dev); | |
522 | ||
1da177e4 | 523 | /* register this i2c device with the driver core */ |
a9b12619 GKH |
524 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, |
525 | MKDEV(I2C_MAJOR, adap->nr), NULL, | |
526 | "i2c-%d", adap->nr); | |
3bacb36d AM |
527 | if (IS_ERR(i2c_dev->dev)) { |
528 | res = PTR_ERR(i2c_dev->dev); | |
1da177e4 | 529 | goto error; |
defcb46e | 530 | } |
ac11d060 | 531 | res = device_create_file(i2c_dev->dev, &dev_attr_name); |
defcb46e JD |
532 | if (res) |
533 | goto error_destroy; | |
b32d20dc JD |
534 | |
535 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
536 | adap->name, adap->nr); | |
1da177e4 | 537 | return 0; |
defcb46e | 538 | error_destroy: |
ac11d060 | 539 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 LT |
540 | error: |
541 | return_i2c_dev(i2c_dev); | |
defcb46e | 542 | return res; |
1da177e4 LT |
543 | } |
544 | ||
545 | static int i2cdev_detach_adapter(struct i2c_adapter *adap) | |
546 | { | |
547 | struct i2c_dev *i2c_dev; | |
548 | ||
9455e4c9 | 549 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
550 | if (!i2c_dev) /* attach_adapter must have failed */ |
551 | return 0; | |
1da177e4 | 552 | |
ac11d060 | 553 | device_remove_file(i2c_dev->dev, &dev_attr_name); |
1da177e4 | 554 | return_i2c_dev(i2c_dev); |
ac11d060 | 555 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 556 | |
b6d7b3d1 | 557 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
558 | return 0; |
559 | } | |
560 | ||
1da177e4 | 561 | static struct i2c_driver i2cdev_driver = { |
35d8b2e6 | 562 | .driver = { |
35d8b2e6 LR |
563 | .name = "dev_driver", |
564 | }, | |
1da177e4 LT |
565 | .attach_adapter = i2cdev_attach_adapter, |
566 | .detach_adapter = i2cdev_detach_adapter, | |
1da177e4 LT |
567 | }; |
568 | ||
907135aa DB |
569 | /* ------------------------------------------------------------------------- */ |
570 | ||
571 | /* | |
572 | * module load/unload record keeping | |
573 | */ | |
574 | ||
1da177e4 LT |
575 | static int __init i2c_dev_init(void) |
576 | { | |
577 | int res; | |
578 | ||
579 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
580 | ||
581 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
582 | if (res) | |
583 | goto out; | |
584 | ||
79472132 | 585 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
e74783ec SW |
586 | if (IS_ERR(i2c_dev_class)) { |
587 | res = PTR_ERR(i2c_dev_class); | |
1da177e4 | 588 | goto out_unreg_chrdev; |
e74783ec | 589 | } |
1da177e4 LT |
590 | |
591 | res = i2c_add_driver(&i2cdev_driver); | |
592 | if (res) | |
593 | goto out_unreg_class; | |
594 | ||
1da177e4 LT |
595 | return 0; |
596 | ||
597 | out_unreg_class: | |
79472132 | 598 | class_destroy(i2c_dev_class); |
1da177e4 LT |
599 | out_unreg_chrdev: |
600 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
601 | out: | |
602 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
603 | return res; | |
604 | } | |
605 | ||
606 | static void __exit i2c_dev_exit(void) | |
607 | { | |
608 | i2c_del_driver(&i2cdev_driver); | |
79472132 | 609 | class_destroy(i2c_dev_class); |
1da177e4 LT |
610 | unregister_chrdev(I2C_MAJOR,"i2c"); |
611 | } | |
612 | ||
613 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
614 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
615 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
616 | MODULE_LICENSE("GPL"); | |
617 | ||
618 | module_init(i2c_dev_init); | |
619 | module_exit(i2c_dev_exit); |