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