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> | |
37 | #include <asm/uaccess.h> | |
38 | ||
22f76e74 | 39 | static struct i2c_driver i2cdev_driver; |
1da177e4 | 40 | |
907135aa DB |
41 | /* |
42 | * An i2c_dev represents an i2c_adapter ... an I2C or SMBus master, not a | |
43 | * slave (i2c_client) with which messages will be exchanged. It's coupled | |
44 | * with a character special file which is accessed by user mode drivers. | |
45 | * | |
46 | * The list of i2c_dev structures is parallel to the i2c_adapter lists | |
47 | * maintained by the driver model, and is updated using notifications | |
48 | * delivered to the i2cdev_driver. | |
49 | */ | |
1da177e4 | 50 | struct i2c_dev { |
f3b3aadb | 51 | struct list_head list; |
1da177e4 | 52 | struct i2c_adapter *adap; |
ac11d060 | 53 | struct device *dev; |
1da177e4 | 54 | }; |
1da177e4 LT |
55 | |
56 | #define I2C_MINORS 256 | |
f3b3aadb JD |
57 | static LIST_HEAD(i2c_dev_list); |
58 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
59 | |
60 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
61 | { | |
62 | struct i2c_dev *i2c_dev; | |
63 | ||
f3b3aadb JD |
64 | spin_lock(&i2c_dev_list_lock); |
65 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
66 | if (i2c_dev->adap->nr == index) | |
67 | goto found; | |
68 | } | |
69 | i2c_dev = NULL; | |
70 | found: | |
71 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
72 | return i2c_dev; |
73 | } | |
74 | ||
1da177e4 LT |
75 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
76 | { | |
77 | struct i2c_dev *i2c_dev; | |
78 | ||
f3b3aadb JD |
79 | if (adap->nr >= I2C_MINORS) { |
80 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
81 | adap->nr); | |
82 | return ERR_PTR(-ENODEV); | |
83 | } | |
84 | ||
5263ebb5 | 85 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
86 | if (!i2c_dev) |
87 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 88 | i2c_dev->adap = adap; |
f3b3aadb JD |
89 | |
90 | spin_lock(&i2c_dev_list_lock); | |
91 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
92 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 93 | return i2c_dev; |
1da177e4 LT |
94 | } |
95 | ||
96 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
97 | { | |
f3b3aadb JD |
98 | spin_lock(&i2c_dev_list_lock); |
99 | list_del(&i2c_dev->list); | |
100 | spin_unlock(&i2c_dev_list_lock); | |
07125ab2 | 101 | kfree(i2c_dev); |
1da177e4 LT |
102 | } |
103 | ||
ac11d060 GKH |
104 | static ssize_t show_adapter_name(struct device *dev, |
105 | struct device_attribute *attr, char *buf) | |
1da177e4 | 106 | { |
ac11d060 | 107 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); |
79472132 GKH |
108 | |
109 | if (!i2c_dev) | |
110 | return -ENODEV; | |
1da177e4 LT |
111 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
112 | } | |
ac11d060 | 113 | static DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); |
1da177e4 | 114 | |
907135aa DB |
115 | /* ------------------------------------------------------------------------- */ |
116 | ||
117 | /* | |
118 | * After opening an instance of this character special file, a file | |
119 | * descriptor starts out associated only with an i2c_adapter (and bus). | |
120 | * | |
121 | * Using the I2C_RDWR ioctl(), you can then *immediately* issue i2c_msg | |
122 | * traffic to any devices on the bus used by that adapter. That's because | |
123 | * the i2c_msg vectors embed all the addressing information they need, and | |
124 | * are submitted directly to an i2c_adapter. However, SMBus-only adapters | |
125 | * don't support that interface. | |
126 | * | |
127 | * To use read()/write() system calls on that file descriptor, or to use | |
128 | * SMBus interfaces (and work with SMBus-only hosts!), you must first issue | |
129 | * an I2C_SLAVE (or I2C_SLAVE_FORCE) ioctl. That configures an anonymous | |
130 | * (never registered) i2c_client so it holds the addressing information | |
131 | * needed by those system calls and by this SMBus interface. | |
132 | */ | |
133 | ||
1da177e4 LT |
134 | static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count, |
135 | loff_t *offset) | |
136 | { | |
137 | char *tmp; | |
138 | int ret; | |
139 | ||
140 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
141 | ||
142 | if (count > 8192) | |
143 | count = 8192; | |
144 | ||
145 | tmp = kmalloc(count,GFP_KERNEL); | |
146 | if (tmp==NULL) | |
147 | return -ENOMEM; | |
148 | ||
149 | pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n", | |
cba0a128 | 150 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 LT |
151 | |
152 | ret = i2c_master_recv(client,tmp,count); | |
153 | if (ret >= 0) | |
154 | ret = copy_to_user(buf,tmp,count)?-EFAULT:ret; | |
155 | kfree(tmp); | |
156 | return ret; | |
157 | } | |
158 | ||
159 | static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count, | |
160 | loff_t *offset) | |
161 | { | |
162 | int ret; | |
163 | char *tmp; | |
164 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
165 | ||
166 | if (count > 8192) | |
167 | count = 8192; | |
168 | ||
169 | tmp = kmalloc(count,GFP_KERNEL); | |
170 | if (tmp==NULL) | |
171 | return -ENOMEM; | |
172 | if (copy_from_user(tmp,buf,count)) { | |
173 | kfree(tmp); | |
174 | return -EFAULT; | |
175 | } | |
176 | ||
177 | pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n", | |
cba0a128 | 178 | iminor(file->f_path.dentry->d_inode), count); |
1da177e4 LT |
179 | |
180 | ret = i2c_master_send(client,tmp,count); | |
181 | kfree(tmp); | |
182 | return ret; | |
183 | } | |
184 | ||
bd4217d8 JD |
185 | /* This address checking function differs from the one in i2c-core |
186 | in that it considers an address with a registered device, but no | |
96acafe0 | 187 | bound driver, as NOT busy. */ |
bd4217d8 JD |
188 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) |
189 | { | |
190 | struct list_head *item; | |
191 | struct i2c_client *client; | |
192 | int res = 0; | |
193 | ||
194 | mutex_lock(&adapter->clist_lock); | |
195 | list_for_each(item, &adapter->clients) { | |
196 | client = list_entry(item, struct i2c_client, list); | |
197 | if (client->addr == addr) { | |
198 | if (client->driver) | |
199 | res = -EBUSY; | |
200 | break; | |
201 | } | |
202 | } | |
203 | mutex_unlock(&adapter->clist_lock); | |
204 | ||
205 | return res; | |
206 | } | |
207 | ||
1da177e4 LT |
208 | static int i2cdev_ioctl(struct inode *inode, struct file *file, |
209 | unsigned int cmd, unsigned long arg) | |
210 | { | |
211 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
212 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
213 | struct i2c_smbus_ioctl_data data_arg; | |
214 | union i2c_smbus_data temp; | |
215 | struct i2c_msg *rdwr_pa; | |
216 | u8 __user **data_ptrs; | |
217 | int i,datasize,res; | |
218 | unsigned long funcs; | |
219 | ||
e8aafcb2 JD |
220 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
221 | cmd, arg); | |
1da177e4 LT |
222 | |
223 | switch ( cmd ) { | |
224 | case I2C_SLAVE: | |
225 | case I2C_SLAVE_FORCE: | |
907135aa DB |
226 | /* NOTE: devices set up to work with "new style" drivers |
227 | * can't use I2C_SLAVE, even when the device node is not | |
228 | * bound to a driver. Only I2C_SLAVE_FORCE will work. | |
229 | * | |
230 | * Setting the PEC flag here won't affect kernel drivers, | |
231 | * which will be using the i2c_client node registered with | |
232 | * the driver model core. Likewise, when that client has | |
233 | * the PEC flag already set, the i2c-dev driver won't see | |
234 | * (or use) this setting. | |
235 | */ | |
438d6c2c | 236 | if ((arg > 0x3ff) || |
1da177e4 LT |
237 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) |
238 | return -EINVAL; | |
bd4217d8 | 239 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) |
1da177e4 | 240 | return -EBUSY; |
bd4217d8 | 241 | /* REVISIT: address could become busy later */ |
1da177e4 LT |
242 | client->addr = arg; |
243 | return 0; | |
244 | case I2C_TENBIT: | |
245 | if (arg) | |
246 | client->flags |= I2C_M_TEN; | |
247 | else | |
248 | client->flags &= ~I2C_M_TEN; | |
249 | return 0; | |
250 | case I2C_PEC: | |
251 | if (arg) | |
252 | client->flags |= I2C_CLIENT_PEC; | |
253 | else | |
254 | client->flags &= ~I2C_CLIENT_PEC; | |
255 | return 0; | |
256 | case I2C_FUNCS: | |
257 | funcs = i2c_get_functionality(client->adapter); | |
2c003e8e | 258 | return put_user(funcs, (unsigned long __user *)arg); |
1da177e4 LT |
259 | |
260 | case I2C_RDWR: | |
438d6c2c DB |
261 | if (copy_from_user(&rdwr_arg, |
262 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
1da177e4 LT |
263 | sizeof(rdwr_arg))) |
264 | return -EFAULT; | |
265 | ||
d68a861d | 266 | /* Put an arbitrary limit on the number of messages that can |
1da177e4 LT |
267 | * be sent at once */ |
268 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
269 | return -EINVAL; | |
438d6c2c | 270 | |
1da177e4 | 271 | rdwr_pa = (struct i2c_msg *) |
438d6c2c | 272 | kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), |
1da177e4 LT |
273 | GFP_KERNEL); |
274 | ||
275 | if (rdwr_pa == NULL) return -ENOMEM; | |
276 | ||
277 | if (copy_from_user(rdwr_pa, rdwr_arg.msgs, | |
278 | rdwr_arg.nmsgs * sizeof(struct i2c_msg))) { | |
279 | kfree(rdwr_pa); | |
280 | return -EFAULT; | |
281 | } | |
282 | ||
283 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
284 | if (data_ptrs == NULL) { | |
285 | kfree(rdwr_pa); | |
286 | return -ENOMEM; | |
287 | } | |
288 | ||
289 | res = 0; | |
290 | for( i=0; i<rdwr_arg.nmsgs; i++ ) { | |
e265cfa1 DB |
291 | /* Limit the size of the message to a sane amount; |
292 | * and don't let length change either. */ | |
293 | if ((rdwr_pa[i].len > 8192) || | |
294 | (rdwr_pa[i].flags & I2C_M_RECV_LEN)) { | |
1da177e4 LT |
295 | res = -EINVAL; |
296 | break; | |
297 | } | |
298 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; | |
299 | rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); | |
300 | if(rdwr_pa[i].buf == NULL) { | |
301 | res = -ENOMEM; | |
302 | break; | |
303 | } | |
304 | if(copy_from_user(rdwr_pa[i].buf, | |
305 | data_ptrs[i], | |
306 | rdwr_pa[i].len)) { | |
307 | ++i; /* Needs to be kfreed too */ | |
308 | res = -EFAULT; | |
309 | break; | |
310 | } | |
311 | } | |
312 | if (res < 0) { | |
313 | int j; | |
314 | for (j = 0; j < i; ++j) | |
315 | kfree(rdwr_pa[j].buf); | |
316 | kfree(data_ptrs); | |
317 | kfree(rdwr_pa); | |
318 | return res; | |
319 | } | |
320 | ||
321 | res = i2c_transfer(client->adapter, | |
322 | rdwr_pa, | |
323 | rdwr_arg.nmsgs); | |
324 | while(i-- > 0) { | |
325 | if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
326 | if(copy_to_user( | |
327 | data_ptrs[i], | |
328 | rdwr_pa[i].buf, | |
329 | rdwr_pa[i].len)) { | |
330 | res = -EFAULT; | |
331 | } | |
332 | } | |
333 | kfree(rdwr_pa[i].buf); | |
334 | } | |
335 | kfree(data_ptrs); | |
336 | kfree(rdwr_pa); | |
337 | return res; | |
338 | ||
339 | case I2C_SMBUS: | |
340 | if (copy_from_user(&data_arg, | |
341 | (struct i2c_smbus_ioctl_data __user *) arg, | |
342 | sizeof(struct i2c_smbus_ioctl_data))) | |
343 | return -EFAULT; | |
438d6c2c | 344 | if ((data_arg.size != I2C_SMBUS_BYTE) && |
1da177e4 | 345 | (data_arg.size != I2C_SMBUS_QUICK) && |
438d6c2c | 346 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && |
1da177e4 LT |
347 | (data_arg.size != I2C_SMBUS_WORD_DATA) && |
348 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
349 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
4b2643d7 | 350 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_BROKEN) && |
1da177e4 LT |
351 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && |
352 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
353 | dev_dbg(&client->adapter->dev, | |
354 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
355 | data_arg.size); | |
356 | return -EINVAL; | |
357 | } | |
438d6c2c | 358 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, |
1da177e4 | 359 | so the check is valid if size==I2C_SMBUS_QUICK too. */ |
438d6c2c | 360 | if ((data_arg.read_write != I2C_SMBUS_READ) && |
1da177e4 | 361 | (data_arg.read_write != I2C_SMBUS_WRITE)) { |
438d6c2c | 362 | dev_dbg(&client->adapter->dev, |
1da177e4 LT |
363 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", |
364 | data_arg.read_write); | |
365 | return -EINVAL; | |
366 | } | |
367 | ||
368 | /* Note that command values are always valid! */ | |
369 | ||
370 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
438d6c2c | 371 | ((data_arg.size == I2C_SMBUS_BYTE) && |
1da177e4 LT |
372 | (data_arg.read_write == I2C_SMBUS_WRITE))) |
373 | /* These are special: we do not use data */ | |
374 | return i2c_smbus_xfer(client->adapter, client->addr, | |
375 | client->flags, | |
376 | data_arg.read_write, | |
377 | data_arg.command, | |
378 | data_arg.size, NULL); | |
379 | ||
380 | if (data_arg.data == NULL) { | |
381 | dev_dbg(&client->adapter->dev, | |
382 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
383 | return -EINVAL; | |
384 | } | |
385 | ||
386 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
387 | (data_arg.size == I2C_SMBUS_BYTE)) | |
388 | datasize = sizeof(data_arg.data->byte); | |
438d6c2c | 389 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || |
1da177e4 LT |
390 | (data_arg.size == I2C_SMBUS_PROC_CALL)) |
391 | datasize = sizeof(data_arg.data->word); | |
392 | else /* size == smbus block, i2c block, or block proc. call */ | |
393 | datasize = sizeof(data_arg.data->block); | |
394 | ||
438d6c2c DB |
395 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || |
396 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
4b2643d7 | 397 | (data_arg.size == I2C_SMBUS_I2C_BLOCK_DATA) || |
1da177e4 LT |
398 | (data_arg.read_write == I2C_SMBUS_WRITE)) { |
399 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
400 | return -EFAULT; | |
401 | } | |
4b2643d7 JD |
402 | if (data_arg.size == I2C_SMBUS_I2C_BLOCK_BROKEN) { |
403 | /* Convert old I2C block commands to the new | |
404 | convention. This preserves binary compatibility. */ | |
405 | data_arg.size = I2C_SMBUS_I2C_BLOCK_DATA; | |
406 | if (data_arg.read_write == I2C_SMBUS_READ) | |
407 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
408 | } | |
1da177e4 LT |
409 | res = i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
410 | data_arg.read_write, | |
411 | data_arg.command,data_arg.size,&temp); | |
438d6c2c DB |
412 | if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || |
413 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
1da177e4 LT |
414 | (data_arg.read_write == I2C_SMBUS_READ))) { |
415 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
416 | return -EFAULT; | |
417 | } | |
418 | return res; | |
53be7959 DB |
419 | case I2C_RETRIES: |
420 | client->adapter->retries = arg; | |
421 | break; | |
422 | case I2C_TIMEOUT: | |
423 | client->adapter->timeout = arg; | |
424 | break; | |
1da177e4 | 425 | default: |
53be7959 DB |
426 | /* NOTE: returning a fault code here could cause trouble |
427 | * in buggy userspace code. Some old kernel bugs returned | |
428 | * zero in this case, and userspace code might accidentally | |
429 | * have depended on that bug. | |
430 | */ | |
431 | return -ENOTTY; | |
1da177e4 LT |
432 | } |
433 | return 0; | |
434 | } | |
435 | ||
436 | static int i2cdev_open(struct inode *inode, struct file *file) | |
437 | { | |
438 | unsigned int minor = iminor(inode); | |
439 | struct i2c_client *client; | |
440 | struct i2c_adapter *adap; | |
441 | struct i2c_dev *i2c_dev; | |
442 | ||
443 | i2c_dev = i2c_dev_get_by_minor(minor); | |
444 | if (!i2c_dev) | |
445 | return -ENODEV; | |
446 | ||
447 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
448 | if (!adap) | |
449 | return -ENODEV; | |
450 | ||
907135aa DB |
451 | /* This creates an anonymous i2c_client, which may later be |
452 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
453 | * | |
454 | * This client is ** NEVER REGISTERED ** with the driver model | |
455 | * or I2C core code!! It just holds private copies of addressing | |
456 | * information and maybe a PEC flag. | |
457 | */ | |
22f76e74 | 458 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
459 | if (!client) { |
460 | i2c_put_adapter(adap); | |
461 | return -ENOMEM; | |
462 | } | |
22f76e74 JD |
463 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
464 | client->driver = &i2cdev_driver; | |
1da177e4 | 465 | |
1da177e4 LT |
466 | client->adapter = adap; |
467 | file->private_data = client; | |
468 | ||
469 | return 0; | |
470 | } | |
471 | ||
472 | static int i2cdev_release(struct inode *inode, struct file *file) | |
473 | { | |
474 | struct i2c_client *client = file->private_data; | |
475 | ||
476 | i2c_put_adapter(client->adapter); | |
477 | kfree(client); | |
478 | file->private_data = NULL; | |
479 | ||
480 | return 0; | |
481 | } | |
482 | ||
2b8693c0 | 483 | static const struct file_operations i2cdev_fops = { |
1da177e4 LT |
484 | .owner = THIS_MODULE, |
485 | .llseek = no_llseek, | |
486 | .read = i2cdev_read, | |
487 | .write = i2cdev_write, | |
488 | .ioctl = i2cdev_ioctl, | |
489 | .open = i2cdev_open, | |
490 | .release = i2cdev_release, | |
491 | }; | |
492 | ||
907135aa DB |
493 | /* ------------------------------------------------------------------------- */ |
494 | ||
495 | /* | |
496 | * The legacy "i2cdev_driver" is used primarily to get notifications when | |
497 | * I2C adapters are added or removed, so that each one gets an i2c_dev | |
498 | * and is thus made available to userspace driver code. | |
499 | */ | |
500 | ||
79472132 | 501 | static struct class *i2c_dev_class; |
1da177e4 LT |
502 | |
503 | static int i2cdev_attach_adapter(struct i2c_adapter *adap) | |
504 | { | |
505 | struct i2c_dev *i2c_dev; | |
defcb46e | 506 | int res; |
1da177e4 LT |
507 | |
508 | i2c_dev = get_free_i2c_dev(adap); | |
509 | if (IS_ERR(i2c_dev)) | |
510 | return PTR_ERR(i2c_dev); | |
511 | ||
1da177e4 | 512 | /* register this i2c device with the driver core */ |
ac11d060 GKH |
513 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, |
514 | MKDEV(I2C_MAJOR, adap->nr), | |
515 | "i2c-%d", adap->nr); | |
3bacb36d AM |
516 | if (IS_ERR(i2c_dev->dev)) { |
517 | res = PTR_ERR(i2c_dev->dev); | |
1da177e4 | 518 | goto error; |
defcb46e | 519 | } |
ac11d060 | 520 | res = device_create_file(i2c_dev->dev, &dev_attr_name); |
defcb46e JD |
521 | if (res) |
522 | goto error_destroy; | |
b32d20dc JD |
523 | |
524 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
525 | adap->name, adap->nr); | |
1da177e4 | 526 | return 0; |
defcb46e | 527 | error_destroy: |
ac11d060 | 528 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 LT |
529 | error: |
530 | return_i2c_dev(i2c_dev); | |
defcb46e | 531 | return res; |
1da177e4 LT |
532 | } |
533 | ||
534 | static int i2cdev_detach_adapter(struct i2c_adapter *adap) | |
535 | { | |
536 | struct i2c_dev *i2c_dev; | |
537 | ||
9455e4c9 | 538 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
b32d20dc JD |
539 | if (!i2c_dev) /* attach_adapter must have failed */ |
540 | return 0; | |
1da177e4 | 541 | |
ac11d060 | 542 | device_remove_file(i2c_dev->dev, &dev_attr_name); |
1da177e4 | 543 | return_i2c_dev(i2c_dev); |
ac11d060 | 544 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 | 545 | |
b6d7b3d1 | 546 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
547 | return 0; |
548 | } | |
549 | ||
550 | static int i2cdev_detach_client(struct i2c_client *client) | |
551 | { | |
552 | return 0; | |
553 | } | |
554 | ||
1da177e4 | 555 | static struct i2c_driver i2cdev_driver = { |
35d8b2e6 | 556 | .driver = { |
35d8b2e6 LR |
557 | .name = "dev_driver", |
558 | }, | |
1da177e4 | 559 | .id = I2C_DRIVERID_I2CDEV, |
1da177e4 LT |
560 | .attach_adapter = i2cdev_attach_adapter, |
561 | .detach_adapter = i2cdev_detach_adapter, | |
562 | .detach_client = i2cdev_detach_client, | |
1da177e4 LT |
563 | }; |
564 | ||
907135aa DB |
565 | /* ------------------------------------------------------------------------- */ |
566 | ||
567 | /* | |
568 | * module load/unload record keeping | |
569 | */ | |
570 | ||
1da177e4 LT |
571 | static int __init i2c_dev_init(void) |
572 | { | |
573 | int res; | |
574 | ||
575 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
576 | ||
577 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
578 | if (res) | |
579 | goto out; | |
580 | ||
79472132 GKH |
581 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
582 | if (IS_ERR(i2c_dev_class)) | |
1da177e4 LT |
583 | goto out_unreg_chrdev; |
584 | ||
585 | res = i2c_add_driver(&i2cdev_driver); | |
586 | if (res) | |
587 | goto out_unreg_class; | |
588 | ||
1da177e4 LT |
589 | return 0; |
590 | ||
591 | out_unreg_class: | |
79472132 | 592 | class_destroy(i2c_dev_class); |
1da177e4 LT |
593 | out_unreg_chrdev: |
594 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
595 | out: | |
596 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
597 | return res; | |
598 | } | |
599 | ||
600 | static void __exit i2c_dev_exit(void) | |
601 | { | |
602 | i2c_del_driver(&i2cdev_driver); | |
79472132 | 603 | class_destroy(i2c_dev_class); |
1da177e4 LT |
604 | unregister_chrdev(I2C_MAJOR,"i2c"); |
605 | } | |
606 | ||
607 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
608 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
609 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
610 | MODULE_LICENSE("GPL"); | |
611 | ||
612 | module_init(i2c_dev_init); | |
613 | module_exit(i2c_dev_exit); |