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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 | #include <linux/compat.h> | |
39 | ||
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 | |
46 | * maintained by the driver model, and is updated using bus notifications. | |
47 | */ | |
48 | struct i2c_dev { | |
49 | struct list_head list; | |
50 | struct i2c_adapter *adap; | |
51 | struct device *dev; | |
52 | struct cdev cdev; | |
53 | }; | |
54 | ||
55 | #define I2C_MINORS MINORMASK | |
56 | static LIST_HEAD(i2c_dev_list); | |
57 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
58 | ||
59 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
60 | { | |
61 | struct i2c_dev *i2c_dev; | |
62 | ||
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); | |
71 | return i2c_dev; | |
72 | } | |
73 | ||
74 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) | |
75 | { | |
76 | struct i2c_dev *i2c_dev; | |
77 | ||
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 | ||
84 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); | |
85 | if (!i2c_dev) | |
86 | return ERR_PTR(-ENOMEM); | |
87 | i2c_dev->adap = adap; | |
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); | |
92 | return i2c_dev; | |
93 | } | |
94 | ||
95 | static void put_i2c_dev(struct i2c_dev *i2c_dev) | |
96 | { | |
97 | spin_lock(&i2c_dev_list_lock); | |
98 | list_del(&i2c_dev->list); | |
99 | spin_unlock(&i2c_dev_list_lock); | |
100 | kfree(i2c_dev); | |
101 | } | |
102 | ||
103 | static ssize_t name_show(struct device *dev, | |
104 | struct device_attribute *attr, char *buf) | |
105 | { | |
106 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(dev->devt)); | |
107 | ||
108 | if (!i2c_dev) | |
109 | return -ENODEV; | |
110 | return sprintf(buf, "%s\n", i2c_dev->adap->name); | |
111 | } | |
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); | |
119 | ||
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 | ||
139 | static ssize_t i2cdev_read(struct file *file, char __user *buf, size_t count, | |
140 | loff_t *offset) | |
141 | { | |
142 | char *tmp; | |
143 | int ret; | |
144 | ||
145 | struct i2c_client *client = file->private_data; | |
146 | ||
147 | if (count > 8192) | |
148 | count = 8192; | |
149 | ||
150 | tmp = kmalloc(count, GFP_KERNEL); | |
151 | if (tmp == NULL) | |
152 | return -ENOMEM; | |
153 | ||
154 | pr_debug("i2c-dev: i2c-%d reading %zu bytes.\n", | |
155 | iminor(file_inode(file)), count); | |
156 | ||
157 | ret = i2c_master_recv(client, tmp, count); | |
158 | if (ret >= 0) | |
159 | ret = copy_to_user(buf, tmp, count) ? -EFAULT : ret; | |
160 | kfree(tmp); | |
161 | return ret; | |
162 | } | |
163 | ||
164 | static ssize_t i2cdev_write(struct file *file, const char __user *buf, | |
165 | size_t count, loff_t *offset) | |
166 | { | |
167 | int ret; | |
168 | char *tmp; | |
169 | struct i2c_client *client = file->private_data; | |
170 | ||
171 | if (count > 8192) | |
172 | count = 8192; | |
173 | ||
174 | tmp = memdup_user(buf, count); | |
175 | if (IS_ERR(tmp)) | |
176 | return PTR_ERR(tmp); | |
177 | ||
178 | pr_debug("i2c-dev: i2c-%d writing %zu bytes.\n", | |
179 | iminor(file_inode(file)), count); | |
180 | ||
181 | ret = i2c_master_send(client, tmp, count); | |
182 | kfree(tmp); | |
183 | return ret; | |
184 | } | |
185 | ||
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 | ||
196 | /* walk up mux tree */ | |
197 | static int i2cdev_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
198 | { | |
199 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); | |
200 | int result; | |
201 | ||
202 | result = device_for_each_child(&adapter->dev, &addr, i2cdev_check); | |
203 | if (!result && parent) | |
204 | result = i2cdev_check_mux_parents(parent, addr); | |
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 | ||
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 | |
225 | driver bound to it, as NOT busy. */ | |
226 | static int i2cdev_check_addr(struct i2c_adapter *adapter, unsigned int addr) | |
227 | { | |
228 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); | |
229 | int result = 0; | |
230 | ||
231 | if (parent) | |
232 | result = i2cdev_check_mux_parents(parent, addr); | |
233 | ||
234 | if (!result) | |
235 | result = device_for_each_child(&adapter->dev, &addr, | |
236 | i2cdev_check_mux_children); | |
237 | ||
238 | return result; | |
239 | } | |
240 | ||
241 | static noinline int i2cdev_ioctl_rdwr(struct i2c_client *client, | |
242 | unsigned nmsgs, struct i2c_msg *msgs) | |
243 | { | |
244 | u8 __user **data_ptrs; | |
245 | int i, res; | |
246 | ||
247 | data_ptrs = kmalloc(nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
248 | if (data_ptrs == NULL) { | |
249 | kfree(msgs); | |
250 | return -ENOMEM; | |
251 | } | |
252 | ||
253 | res = 0; | |
254 | for (i = 0; i < nmsgs; i++) { | |
255 | /* Limit the size of the message to a sane amount */ | |
256 | if (msgs[i].len > 8192) { | |
257 | res = -EINVAL; | |
258 | break; | |
259 | } | |
260 | ||
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); | |
265 | break; | |
266 | } | |
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 | */ | |
279 | if (msgs[i].flags & I2C_M_RECV_LEN) { | |
280 | if (!(msgs[i].flags & I2C_M_RD) || | |
281 | msgs[i].len < 1 || msgs[i].buf[0] < 1 || | |
282 | msgs[i].len < msgs[i].buf[0] + | |
283 | I2C_SMBUS_BLOCK_MAX) { | |
284 | i++; | |
285 | res = -EINVAL; | |
286 | break; | |
287 | } | |
288 | ||
289 | msgs[i].len = msgs[i].buf[0]; | |
290 | } | |
291 | } | |
292 | if (res < 0) { | |
293 | int j; | |
294 | for (j = 0; j < i; ++j) | |
295 | kfree(msgs[j].buf); | |
296 | kfree(data_ptrs); | |
297 | kfree(msgs); | |
298 | return res; | |
299 | } | |
300 | ||
301 | res = i2c_transfer(client->adapter, msgs, nmsgs); | |
302 | while (i-- > 0) { | |
303 | if (res >= 0 && (msgs[i].flags & I2C_M_RD)) { | |
304 | if (copy_to_user(data_ptrs[i], msgs[i].buf, | |
305 | msgs[i].len)) | |
306 | res = -EFAULT; | |
307 | } | |
308 | kfree(msgs[i].buf); | |
309 | } | |
310 | kfree(data_ptrs); | |
311 | kfree(msgs); | |
312 | return res; | |
313 | } | |
314 | ||
315 | static noinline int i2cdev_ioctl_smbus(struct i2c_client *client, | |
316 | u8 read_write, u8 command, u32 size, | |
317 | union i2c_smbus_data __user *data) | |
318 | { | |
319 | union i2c_smbus_data temp = {}; | |
320 | int datasize, res; | |
321 | ||
322 | if ((size != I2C_SMBUS_BYTE) && | |
323 | (size != I2C_SMBUS_QUICK) && | |
324 | (size != I2C_SMBUS_BYTE_DATA) && | |
325 | (size != I2C_SMBUS_WORD_DATA) && | |
326 | (size != I2C_SMBUS_PROC_CALL) && | |
327 | (size != I2C_SMBUS_BLOCK_DATA) && | |
328 | (size != I2C_SMBUS_I2C_BLOCK_BROKEN) && | |
329 | (size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
330 | (size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
331 | dev_dbg(&client->adapter->dev, | |
332 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
333 | size); | |
334 | return -EINVAL; | |
335 | } | |
336 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
337 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
338 | if ((read_write != I2C_SMBUS_READ) && | |
339 | (read_write != I2C_SMBUS_WRITE)) { | |
340 | dev_dbg(&client->adapter->dev, | |
341 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
342 | read_write); | |
343 | return -EINVAL; | |
344 | } | |
345 | ||
346 | /* Note that command values are always valid! */ | |
347 | ||
348 | if ((size == I2C_SMBUS_QUICK) || | |
349 | ((size == I2C_SMBUS_BYTE) && | |
350 | (read_write == I2C_SMBUS_WRITE))) | |
351 | /* These are special: we do not use data */ | |
352 | return i2c_smbus_xfer(client->adapter, client->addr, | |
353 | client->flags, read_write, | |
354 | command, size, NULL); | |
355 | ||
356 | if (data == NULL) { | |
357 | dev_dbg(&client->adapter->dev, | |
358 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
359 | return -EINVAL; | |
360 | } | |
361 | ||
362 | if ((size == I2C_SMBUS_BYTE_DATA) || | |
363 | (size == I2C_SMBUS_BYTE)) | |
364 | datasize = sizeof(data->byte); | |
365 | else if ((size == I2C_SMBUS_WORD_DATA) || | |
366 | (size == I2C_SMBUS_PROC_CALL)) | |
367 | datasize = sizeof(data->word); | |
368 | else /* size == smbus block, i2c block, or block proc. call */ | |
369 | datasize = sizeof(data->block); | |
370 | ||
371 | if ((size == I2C_SMBUS_PROC_CALL) || | |
372 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
373 | (size == I2C_SMBUS_I2C_BLOCK_DATA) || | |
374 | (read_write == I2C_SMBUS_WRITE)) { | |
375 | if (copy_from_user(&temp, data, datasize)) | |
376 | return -EFAULT; | |
377 | } | |
378 | if (size == I2C_SMBUS_I2C_BLOCK_BROKEN) { | |
379 | /* Convert old I2C block commands to the new | |
380 | convention. This preserves binary compatibility. */ | |
381 | size = I2C_SMBUS_I2C_BLOCK_DATA; | |
382 | if (read_write == I2C_SMBUS_READ) | |
383 | temp.block[0] = I2C_SMBUS_BLOCK_MAX; | |
384 | } | |
385 | res = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
386 | read_write, command, size, &temp); | |
387 | if (!res && ((size == I2C_SMBUS_PROC_CALL) || | |
388 | (size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
389 | (read_write == I2C_SMBUS_READ))) { | |
390 | if (copy_to_user(data, &temp, datasize)) | |
391 | return -EFAULT; | |
392 | } | |
393 | return res; | |
394 | } | |
395 | ||
396 | static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
397 | { | |
398 | struct i2c_client *client = file->private_data; | |
399 | unsigned long funcs; | |
400 | ||
401 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", | |
402 | cmd, arg); | |
403 | ||
404 | switch (cmd) { | |
405 | case I2C_SLAVE: | |
406 | case I2C_SLAVE_FORCE: | |
407 | if ((arg > 0x3ff) || | |
408 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) | |
409 | return -EINVAL; | |
410 | if (cmd == I2C_SLAVE && i2cdev_check_addr(client->adapter, arg)) | |
411 | return -EBUSY; | |
412 | /* REVISIT: address could become busy later */ | |
413 | client->addr = arg; | |
414 | return 0; | |
415 | case I2C_TENBIT: | |
416 | if (arg) | |
417 | client->flags |= I2C_M_TEN; | |
418 | else | |
419 | client->flags &= ~I2C_M_TEN; | |
420 | return 0; | |
421 | case I2C_PEC: | |
422 | /* | |
423 | * Setting the PEC flag here won't affect kernel drivers, | |
424 | * which will be using the i2c_client node registered with | |
425 | * the driver model core. Likewise, when that client has | |
426 | * the PEC flag already set, the i2c-dev driver won't see | |
427 | * (or use) this setting. | |
428 | */ | |
429 | if (arg) | |
430 | client->flags |= I2C_CLIENT_PEC; | |
431 | else | |
432 | client->flags &= ~I2C_CLIENT_PEC; | |
433 | return 0; | |
434 | case I2C_FUNCS: | |
435 | funcs = i2c_get_functionality(client->adapter); | |
436 | return put_user(funcs, (unsigned long __user *)arg); | |
437 | ||
438 | case I2C_RDWR: { | |
439 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
440 | struct i2c_msg *rdwr_pa; | |
441 | ||
442 | if (copy_from_user(&rdwr_arg, | |
443 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
444 | sizeof(rdwr_arg))) | |
445 | return -EFAULT; | |
446 | ||
447 | /* Put an arbitrary limit on the number of messages that can | |
448 | * be sent at once */ | |
449 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) | |
450 | return -EINVAL; | |
451 | ||
452 | rdwr_pa = memdup_user(rdwr_arg.msgs, | |
453 | rdwr_arg.nmsgs * sizeof(struct i2c_msg)); | |
454 | if (IS_ERR(rdwr_pa)) | |
455 | return PTR_ERR(rdwr_pa); | |
456 | ||
457 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
458 | } | |
459 | ||
460 | case I2C_SMBUS: { | |
461 | struct i2c_smbus_ioctl_data data_arg; | |
462 | if (copy_from_user(&data_arg, | |
463 | (struct i2c_smbus_ioctl_data __user *) arg, | |
464 | sizeof(struct i2c_smbus_ioctl_data))) | |
465 | return -EFAULT; | |
466 | return i2cdev_ioctl_smbus(client, data_arg.read_write, | |
467 | data_arg.command, | |
468 | data_arg.size, | |
469 | data_arg.data); | |
470 | } | |
471 | case I2C_RETRIES: | |
472 | if (arg > INT_MAX) | |
473 | return -EINVAL; | |
474 | ||
475 | client->adapter->retries = arg; | |
476 | break; | |
477 | case I2C_TIMEOUT: | |
478 | if (arg > INT_MAX) | |
479 | return -EINVAL; | |
480 | ||
481 | /* For historical reasons, user-space sets the timeout | |
482 | * value in units of 10 ms. | |
483 | */ | |
484 | client->adapter->timeout = msecs_to_jiffies(arg * 10); | |
485 | break; | |
486 | default: | |
487 | /* NOTE: returning a fault code here could cause trouble | |
488 | * in buggy userspace code. Some old kernel bugs returned | |
489 | * zero in this case, and userspace code might accidentally | |
490 | * have depended on that bug. | |
491 | */ | |
492 | return -ENOTTY; | |
493 | } | |
494 | return 0; | |
495 | } | |
496 | ||
497 | #ifdef CONFIG_COMPAT | |
498 | ||
499 | struct i2c_smbus_ioctl_data32 { | |
500 | u8 read_write; | |
501 | u8 command; | |
502 | u32 size; | |
503 | compat_caddr_t data; /* union i2c_smbus_data *data */ | |
504 | }; | |
505 | ||
506 | struct i2c_msg32 { | |
507 | u16 addr; | |
508 | u16 flags; | |
509 | u16 len; | |
510 | compat_caddr_t buf; | |
511 | }; | |
512 | ||
513 | struct i2c_rdwr_ioctl_data32 { | |
514 | compat_caddr_t msgs; /* struct i2c_msg __user *msgs */ | |
515 | u32 nmsgs; | |
516 | }; | |
517 | ||
518 | static long compat_i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) | |
519 | { | |
520 | struct i2c_client *client = file->private_data; | |
521 | unsigned long funcs; | |
522 | switch (cmd) { | |
523 | case I2C_FUNCS: | |
524 | funcs = i2c_get_functionality(client->adapter); | |
525 | return put_user(funcs, (compat_ulong_t __user *)arg); | |
526 | case I2C_RDWR: { | |
527 | struct i2c_rdwr_ioctl_data32 rdwr_arg; | |
528 | struct i2c_msg32 *p; | |
529 | struct i2c_msg *rdwr_pa; | |
530 | int i; | |
531 | ||
532 | if (copy_from_user(&rdwr_arg, | |
533 | (struct i2c_rdwr_ioctl_data32 __user *)arg, | |
534 | sizeof(rdwr_arg))) | |
535 | return -EFAULT; | |
536 | ||
537 | if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) | |
538 | return -EINVAL; | |
539 | ||
540 | rdwr_pa = kmalloc_array(rdwr_arg.nmsgs, sizeof(struct i2c_msg), | |
541 | GFP_KERNEL); | |
542 | if (!rdwr_pa) | |
543 | return -ENOMEM; | |
544 | ||
545 | p = compat_ptr(rdwr_arg.msgs); | |
546 | for (i = 0; i < rdwr_arg.nmsgs; i++) { | |
547 | struct i2c_msg32 umsg; | |
548 | if (copy_from_user(&umsg, p + i, sizeof(umsg))) { | |
549 | kfree(rdwr_pa); | |
550 | return -EFAULT; | |
551 | } | |
552 | rdwr_pa[i] = (struct i2c_msg) { | |
553 | .addr = umsg.addr, | |
554 | .flags = umsg.flags, | |
555 | .len = umsg.len, | |
556 | .buf = compat_ptr(umsg.buf) | |
557 | }; | |
558 | } | |
559 | ||
560 | return i2cdev_ioctl_rdwr(client, rdwr_arg.nmsgs, rdwr_pa); | |
561 | } | |
562 | case I2C_SMBUS: { | |
563 | struct i2c_smbus_ioctl_data32 data32; | |
564 | if (copy_from_user(&data32, | |
565 | (void __user *) arg, | |
566 | sizeof(data32))) | |
567 | return -EFAULT; | |
568 | return i2cdev_ioctl_smbus(client, data32.read_write, | |
569 | data32.command, | |
570 | data32.size, | |
571 | compat_ptr(data32.data)); | |
572 | } | |
573 | default: | |
574 | return i2cdev_ioctl(file, cmd, arg); | |
575 | } | |
576 | } | |
577 | #else | |
578 | #define compat_i2cdev_ioctl NULL | |
579 | #endif | |
580 | ||
581 | static int i2cdev_open(struct inode *inode, struct file *file) | |
582 | { | |
583 | unsigned int minor = iminor(inode); | |
584 | struct i2c_client *client; | |
585 | struct i2c_adapter *adap; | |
586 | ||
587 | adap = i2c_get_adapter(minor); | |
588 | if (!adap) | |
589 | return -ENODEV; | |
590 | ||
591 | /* This creates an anonymous i2c_client, which may later be | |
592 | * pointed to some address using I2C_SLAVE or I2C_SLAVE_FORCE. | |
593 | * | |
594 | * This client is ** NEVER REGISTERED ** with the driver model | |
595 | * or I2C core code!! It just holds private copies of addressing | |
596 | * information and maybe a PEC flag. | |
597 | */ | |
598 | client = kzalloc(sizeof(*client), GFP_KERNEL); | |
599 | if (!client) { | |
600 | i2c_put_adapter(adap); | |
601 | return -ENOMEM; | |
602 | } | |
603 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); | |
604 | ||
605 | client->adapter = adap; | |
606 | file->private_data = client; | |
607 | ||
608 | return 0; | |
609 | } | |
610 | ||
611 | static int i2cdev_release(struct inode *inode, struct file *file) | |
612 | { | |
613 | struct i2c_client *client = file->private_data; | |
614 | ||
615 | i2c_put_adapter(client->adapter); | |
616 | kfree(client); | |
617 | file->private_data = NULL; | |
618 | ||
619 | return 0; | |
620 | } | |
621 | ||
622 | static const struct file_operations i2cdev_fops = { | |
623 | .owner = THIS_MODULE, | |
624 | .llseek = no_llseek, | |
625 | .read = i2cdev_read, | |
626 | .write = i2cdev_write, | |
627 | .unlocked_ioctl = i2cdev_ioctl, | |
628 | .compat_ioctl = compat_i2cdev_ioctl, | |
629 | .open = i2cdev_open, | |
630 | .release = i2cdev_release, | |
631 | }; | |
632 | ||
633 | /* ------------------------------------------------------------------------- */ | |
634 | ||
635 | static struct class *i2c_dev_class; | |
636 | ||
637 | static int i2cdev_attach_adapter(struct device *dev, void *dummy) | |
638 | { | |
639 | struct i2c_adapter *adap; | |
640 | struct i2c_dev *i2c_dev; | |
641 | int res; | |
642 | ||
643 | if (dev->type != &i2c_adapter_type) | |
644 | return 0; | |
645 | adap = to_i2c_adapter(dev); | |
646 | ||
647 | i2c_dev = get_free_i2c_dev(adap); | |
648 | if (IS_ERR(i2c_dev)) | |
649 | return PTR_ERR(i2c_dev); | |
650 | ||
651 | cdev_init(&i2c_dev->cdev, &i2cdev_fops); | |
652 | i2c_dev->cdev.owner = THIS_MODULE; | |
653 | res = cdev_add(&i2c_dev->cdev, MKDEV(I2C_MAJOR, adap->nr), 1); | |
654 | if (res) | |
655 | goto error_cdev; | |
656 | ||
657 | /* register this i2c device with the driver core */ | |
658 | i2c_dev->dev = device_create(i2c_dev_class, &adap->dev, | |
659 | MKDEV(I2C_MAJOR, adap->nr), NULL, | |
660 | "i2c-%d", adap->nr); | |
661 | if (IS_ERR(i2c_dev->dev)) { | |
662 | res = PTR_ERR(i2c_dev->dev); | |
663 | goto error; | |
664 | } | |
665 | ||
666 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", | |
667 | adap->name, adap->nr); | |
668 | return 0; | |
669 | error: | |
670 | cdev_del(&i2c_dev->cdev); | |
671 | error_cdev: | |
672 | put_i2c_dev(i2c_dev); | |
673 | return res; | |
674 | } | |
675 | ||
676 | static int i2cdev_detach_adapter(struct device *dev, void *dummy) | |
677 | { | |
678 | struct i2c_adapter *adap; | |
679 | struct i2c_dev *i2c_dev; | |
680 | ||
681 | if (dev->type != &i2c_adapter_type) | |
682 | return 0; | |
683 | adap = to_i2c_adapter(dev); | |
684 | ||
685 | i2c_dev = i2c_dev_get_by_minor(adap->nr); | |
686 | if (!i2c_dev) /* attach_adapter must have failed */ | |
687 | return 0; | |
688 | ||
689 | cdev_del(&i2c_dev->cdev); | |
690 | put_i2c_dev(i2c_dev); | |
691 | device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); | |
692 | ||
693 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); | |
694 | return 0; | |
695 | } | |
696 | ||
697 | static int i2cdev_notifier_call(struct notifier_block *nb, unsigned long action, | |
698 | void *data) | |
699 | { | |
700 | struct device *dev = data; | |
701 | ||
702 | switch (action) { | |
703 | case BUS_NOTIFY_ADD_DEVICE: | |
704 | return i2cdev_attach_adapter(dev, NULL); | |
705 | case BUS_NOTIFY_DEL_DEVICE: | |
706 | return i2cdev_detach_adapter(dev, NULL); | |
707 | } | |
708 | ||
709 | return 0; | |
710 | } | |
711 | ||
712 | static struct notifier_block i2cdev_notifier = { | |
713 | .notifier_call = i2cdev_notifier_call, | |
714 | }; | |
715 | ||
716 | /* ------------------------------------------------------------------------- */ | |
717 | ||
718 | /* | |
719 | * module load/unload record keeping | |
720 | */ | |
721 | ||
722 | static int __init i2c_dev_init(void) | |
723 | { | |
724 | int res; | |
725 | ||
726 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
727 | ||
728 | res = register_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS, "i2c"); | |
729 | if (res) | |
730 | goto out; | |
731 | ||
732 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); | |
733 | if (IS_ERR(i2c_dev_class)) { | |
734 | res = PTR_ERR(i2c_dev_class); | |
735 | goto out_unreg_chrdev; | |
736 | } | |
737 | i2c_dev_class->dev_groups = i2c_groups; | |
738 | ||
739 | /* Keep track of adapters which will be added or removed later */ | |
740 | res = bus_register_notifier(&i2c_bus_type, &i2cdev_notifier); | |
741 | if (res) | |
742 | goto out_unreg_class; | |
743 | ||
744 | /* Bind to already existing adapters right away */ | |
745 | i2c_for_each_dev(NULL, i2cdev_attach_adapter); | |
746 | ||
747 | return 0; | |
748 | ||
749 | out_unreg_class: | |
750 | class_destroy(i2c_dev_class); | |
751 | out_unreg_chrdev: | |
752 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); | |
753 | out: | |
754 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
755 | return res; | |
756 | } | |
757 | ||
758 | static void __exit i2c_dev_exit(void) | |
759 | { | |
760 | bus_unregister_notifier(&i2c_bus_type, &i2cdev_notifier); | |
761 | i2c_for_each_dev(NULL, i2cdev_detach_adapter); | |
762 | class_destroy(i2c_dev_class); | |
763 | unregister_chrdev_region(MKDEV(I2C_MAJOR, 0), I2C_MINORS); | |
764 | } | |
765 | ||
766 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
767 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
768 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
769 | MODULE_LICENSE("GPL"); | |
770 | ||
771 | module_init(i2c_dev_init); | |
772 | module_exit(i2c_dev_exit); |