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1da177e4 LT |
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 | 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> | |
33 | #include <linux/smp_lock.h> | |
1da177e4 | 34 | #include <linux/init.h> |
f3b3aadb | 35 | #include <linux/list.h> |
1da177e4 LT |
36 | #include <linux/i2c.h> |
37 | #include <linux/i2c-dev.h> | |
38 | #include <asm/uaccess.h> | |
39 | ||
22f76e74 | 40 | static struct i2c_driver i2cdev_driver; |
1da177e4 LT |
41 | |
42 | struct i2c_dev { | |
f3b3aadb | 43 | struct list_head list; |
1da177e4 | 44 | struct i2c_adapter *adap; |
79472132 | 45 | struct class_device *class_dev; |
1da177e4 | 46 | }; |
1da177e4 LT |
47 | |
48 | #define I2C_MINORS 256 | |
f3b3aadb JD |
49 | static LIST_HEAD(i2c_dev_list); |
50 | static DEFINE_SPINLOCK(i2c_dev_list_lock); | |
1da177e4 LT |
51 | |
52 | static struct i2c_dev *i2c_dev_get_by_minor(unsigned index) | |
53 | { | |
54 | struct i2c_dev *i2c_dev; | |
55 | ||
f3b3aadb JD |
56 | spin_lock(&i2c_dev_list_lock); |
57 | list_for_each_entry(i2c_dev, &i2c_dev_list, list) { | |
58 | if (i2c_dev->adap->nr == index) | |
59 | goto found; | |
60 | } | |
61 | i2c_dev = NULL; | |
62 | found: | |
63 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
64 | return i2c_dev; |
65 | } | |
66 | ||
1da177e4 LT |
67 | static struct i2c_dev *get_free_i2c_dev(struct i2c_adapter *adap) |
68 | { | |
69 | struct i2c_dev *i2c_dev; | |
70 | ||
f3b3aadb JD |
71 | if (adap->nr >= I2C_MINORS) { |
72 | printk(KERN_ERR "i2c-dev: Out of device minors (%d)\n", | |
73 | adap->nr); | |
74 | return ERR_PTR(-ENODEV); | |
75 | } | |
76 | ||
5263ebb5 | 77 | i2c_dev = kzalloc(sizeof(*i2c_dev), GFP_KERNEL); |
1da177e4 LT |
78 | if (!i2c_dev) |
79 | return ERR_PTR(-ENOMEM); | |
9455e4c9 | 80 | i2c_dev->adap = adap; |
f3b3aadb JD |
81 | |
82 | spin_lock(&i2c_dev_list_lock); | |
83 | list_add_tail(&i2c_dev->list, &i2c_dev_list); | |
84 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 | 85 | return i2c_dev; |
1da177e4 LT |
86 | } |
87 | ||
88 | static void return_i2c_dev(struct i2c_dev *i2c_dev) | |
89 | { | |
f3b3aadb JD |
90 | spin_lock(&i2c_dev_list_lock); |
91 | list_del(&i2c_dev->list); | |
92 | spin_unlock(&i2c_dev_list_lock); | |
1da177e4 LT |
93 | } |
94 | ||
95 | static ssize_t show_adapter_name(struct class_device *class_dev, char *buf) | |
96 | { | |
79472132 GKH |
97 | struct i2c_dev *i2c_dev = i2c_dev_get_by_minor(MINOR(class_dev->devt)); |
98 | ||
99 | if (!i2c_dev) | |
100 | return -ENODEV; | |
1da177e4 LT |
101 | return sprintf(buf, "%s\n", i2c_dev->adap->name); |
102 | } | |
103 | static CLASS_DEVICE_ATTR(name, S_IRUGO, show_adapter_name, NULL); | |
104 | ||
105 | static ssize_t i2cdev_read (struct file *file, char __user *buf, size_t count, | |
106 | loff_t *offset) | |
107 | { | |
108 | char *tmp; | |
109 | int ret; | |
110 | ||
111 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
112 | ||
113 | if (count > 8192) | |
114 | count = 8192; | |
115 | ||
116 | tmp = kmalloc(count,GFP_KERNEL); | |
117 | if (tmp==NULL) | |
118 | return -ENOMEM; | |
119 | ||
120 | pr_debug("i2c-dev: i2c-%d reading %zd bytes.\n", | |
121 | iminor(file->f_dentry->d_inode), count); | |
122 | ||
123 | ret = i2c_master_recv(client,tmp,count); | |
124 | if (ret >= 0) | |
125 | ret = copy_to_user(buf,tmp,count)?-EFAULT:ret; | |
126 | kfree(tmp); | |
127 | return ret; | |
128 | } | |
129 | ||
130 | static ssize_t i2cdev_write (struct file *file, const char __user *buf, size_t count, | |
131 | loff_t *offset) | |
132 | { | |
133 | int ret; | |
134 | char *tmp; | |
135 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
136 | ||
137 | if (count > 8192) | |
138 | count = 8192; | |
139 | ||
140 | tmp = kmalloc(count,GFP_KERNEL); | |
141 | if (tmp==NULL) | |
142 | return -ENOMEM; | |
143 | if (copy_from_user(tmp,buf,count)) { | |
144 | kfree(tmp); | |
145 | return -EFAULT; | |
146 | } | |
147 | ||
148 | pr_debug("i2c-dev: i2c-%d writing %zd bytes.\n", | |
149 | iminor(file->f_dentry->d_inode), count); | |
150 | ||
151 | ret = i2c_master_send(client,tmp,count); | |
152 | kfree(tmp); | |
153 | return ret; | |
154 | } | |
155 | ||
156 | static int i2cdev_ioctl(struct inode *inode, struct file *file, | |
157 | unsigned int cmd, unsigned long arg) | |
158 | { | |
159 | struct i2c_client *client = (struct i2c_client *)file->private_data; | |
160 | struct i2c_rdwr_ioctl_data rdwr_arg; | |
161 | struct i2c_smbus_ioctl_data data_arg; | |
162 | union i2c_smbus_data temp; | |
163 | struct i2c_msg *rdwr_pa; | |
164 | u8 __user **data_ptrs; | |
165 | int i,datasize,res; | |
166 | unsigned long funcs; | |
167 | ||
e8aafcb2 JD |
168 | dev_dbg(&client->adapter->dev, "ioctl, cmd=0x%02x, arg=0x%02lx\n", |
169 | cmd, arg); | |
1da177e4 LT |
170 | |
171 | switch ( cmd ) { | |
172 | case I2C_SLAVE: | |
173 | case I2C_SLAVE_FORCE: | |
174 | if ((arg > 0x3ff) || | |
175 | (((client->flags & I2C_M_TEN) == 0) && arg > 0x7f)) | |
176 | return -EINVAL; | |
177 | if ((cmd == I2C_SLAVE) && i2c_check_addr(client->adapter,arg)) | |
178 | return -EBUSY; | |
179 | client->addr = arg; | |
180 | return 0; | |
181 | case I2C_TENBIT: | |
182 | if (arg) | |
183 | client->flags |= I2C_M_TEN; | |
184 | else | |
185 | client->flags &= ~I2C_M_TEN; | |
186 | return 0; | |
187 | case I2C_PEC: | |
188 | if (arg) | |
189 | client->flags |= I2C_CLIENT_PEC; | |
190 | else | |
191 | client->flags &= ~I2C_CLIENT_PEC; | |
192 | return 0; | |
193 | case I2C_FUNCS: | |
194 | funcs = i2c_get_functionality(client->adapter); | |
195 | return (copy_to_user((unsigned long __user *)arg, &funcs, | |
196 | sizeof(unsigned long)))?-EFAULT:0; | |
197 | ||
198 | case I2C_RDWR: | |
199 | if (copy_from_user(&rdwr_arg, | |
200 | (struct i2c_rdwr_ioctl_data __user *)arg, | |
201 | sizeof(rdwr_arg))) | |
202 | return -EFAULT; | |
203 | ||
d68a861d | 204 | /* Put an arbitrary limit on the number of messages that can |
1da177e4 LT |
205 | * be sent at once */ |
206 | if (rdwr_arg.nmsgs > I2C_RDRW_IOCTL_MAX_MSGS) | |
207 | return -EINVAL; | |
208 | ||
209 | rdwr_pa = (struct i2c_msg *) | |
210 | kmalloc(rdwr_arg.nmsgs * sizeof(struct i2c_msg), | |
211 | GFP_KERNEL); | |
212 | ||
213 | if (rdwr_pa == NULL) return -ENOMEM; | |
214 | ||
215 | if (copy_from_user(rdwr_pa, rdwr_arg.msgs, | |
216 | rdwr_arg.nmsgs * sizeof(struct i2c_msg))) { | |
217 | kfree(rdwr_pa); | |
218 | return -EFAULT; | |
219 | } | |
220 | ||
221 | data_ptrs = kmalloc(rdwr_arg.nmsgs * sizeof(u8 __user *), GFP_KERNEL); | |
222 | if (data_ptrs == NULL) { | |
223 | kfree(rdwr_pa); | |
224 | return -ENOMEM; | |
225 | } | |
226 | ||
227 | res = 0; | |
228 | for( i=0; i<rdwr_arg.nmsgs; i++ ) { | |
229 | /* Limit the size of the message to a sane amount */ | |
230 | if (rdwr_pa[i].len > 8192) { | |
231 | res = -EINVAL; | |
232 | break; | |
233 | } | |
234 | data_ptrs[i] = (u8 __user *)rdwr_pa[i].buf; | |
235 | rdwr_pa[i].buf = kmalloc(rdwr_pa[i].len, GFP_KERNEL); | |
236 | if(rdwr_pa[i].buf == NULL) { | |
237 | res = -ENOMEM; | |
238 | break; | |
239 | } | |
240 | if(copy_from_user(rdwr_pa[i].buf, | |
241 | data_ptrs[i], | |
242 | rdwr_pa[i].len)) { | |
243 | ++i; /* Needs to be kfreed too */ | |
244 | res = -EFAULT; | |
245 | break; | |
246 | } | |
247 | } | |
248 | if (res < 0) { | |
249 | int j; | |
250 | for (j = 0; j < i; ++j) | |
251 | kfree(rdwr_pa[j].buf); | |
252 | kfree(data_ptrs); | |
253 | kfree(rdwr_pa); | |
254 | return res; | |
255 | } | |
256 | ||
257 | res = i2c_transfer(client->adapter, | |
258 | rdwr_pa, | |
259 | rdwr_arg.nmsgs); | |
260 | while(i-- > 0) { | |
261 | if( res>=0 && (rdwr_pa[i].flags & I2C_M_RD)) { | |
262 | if(copy_to_user( | |
263 | data_ptrs[i], | |
264 | rdwr_pa[i].buf, | |
265 | rdwr_pa[i].len)) { | |
266 | res = -EFAULT; | |
267 | } | |
268 | } | |
269 | kfree(rdwr_pa[i].buf); | |
270 | } | |
271 | kfree(data_ptrs); | |
272 | kfree(rdwr_pa); | |
273 | return res; | |
274 | ||
275 | case I2C_SMBUS: | |
276 | if (copy_from_user(&data_arg, | |
277 | (struct i2c_smbus_ioctl_data __user *) arg, | |
278 | sizeof(struct i2c_smbus_ioctl_data))) | |
279 | return -EFAULT; | |
280 | if ((data_arg.size != I2C_SMBUS_BYTE) && | |
281 | (data_arg.size != I2C_SMBUS_QUICK) && | |
282 | (data_arg.size != I2C_SMBUS_BYTE_DATA) && | |
283 | (data_arg.size != I2C_SMBUS_WORD_DATA) && | |
284 | (data_arg.size != I2C_SMBUS_PROC_CALL) && | |
285 | (data_arg.size != I2C_SMBUS_BLOCK_DATA) && | |
286 | (data_arg.size != I2C_SMBUS_I2C_BLOCK_DATA) && | |
287 | (data_arg.size != I2C_SMBUS_BLOCK_PROC_CALL)) { | |
288 | dev_dbg(&client->adapter->dev, | |
289 | "size out of range (%x) in ioctl I2C_SMBUS.\n", | |
290 | data_arg.size); | |
291 | return -EINVAL; | |
292 | } | |
293 | /* Note that I2C_SMBUS_READ and I2C_SMBUS_WRITE are 0 and 1, | |
294 | so the check is valid if size==I2C_SMBUS_QUICK too. */ | |
295 | if ((data_arg.read_write != I2C_SMBUS_READ) && | |
296 | (data_arg.read_write != I2C_SMBUS_WRITE)) { | |
297 | dev_dbg(&client->adapter->dev, | |
298 | "read_write out of range (%x) in ioctl I2C_SMBUS.\n", | |
299 | data_arg.read_write); | |
300 | return -EINVAL; | |
301 | } | |
302 | ||
303 | /* Note that command values are always valid! */ | |
304 | ||
305 | if ((data_arg.size == I2C_SMBUS_QUICK) || | |
306 | ((data_arg.size == I2C_SMBUS_BYTE) && | |
307 | (data_arg.read_write == I2C_SMBUS_WRITE))) | |
308 | /* These are special: we do not use data */ | |
309 | return i2c_smbus_xfer(client->adapter, client->addr, | |
310 | client->flags, | |
311 | data_arg.read_write, | |
312 | data_arg.command, | |
313 | data_arg.size, NULL); | |
314 | ||
315 | if (data_arg.data == NULL) { | |
316 | dev_dbg(&client->adapter->dev, | |
317 | "data is NULL pointer in ioctl I2C_SMBUS.\n"); | |
318 | return -EINVAL; | |
319 | } | |
320 | ||
321 | if ((data_arg.size == I2C_SMBUS_BYTE_DATA) || | |
322 | (data_arg.size == I2C_SMBUS_BYTE)) | |
323 | datasize = sizeof(data_arg.data->byte); | |
324 | else if ((data_arg.size == I2C_SMBUS_WORD_DATA) || | |
325 | (data_arg.size == I2C_SMBUS_PROC_CALL)) | |
326 | datasize = sizeof(data_arg.data->word); | |
327 | else /* size == smbus block, i2c block, or block proc. call */ | |
328 | datasize = sizeof(data_arg.data->block); | |
329 | ||
330 | if ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
331 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
332 | (data_arg.read_write == I2C_SMBUS_WRITE)) { | |
333 | if (copy_from_user(&temp, data_arg.data, datasize)) | |
334 | return -EFAULT; | |
335 | } | |
336 | res = i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
337 | data_arg.read_write, | |
338 | data_arg.command,data_arg.size,&temp); | |
339 | if (! res && ((data_arg.size == I2C_SMBUS_PROC_CALL) || | |
340 | (data_arg.size == I2C_SMBUS_BLOCK_PROC_CALL) || | |
341 | (data_arg.read_write == I2C_SMBUS_READ))) { | |
342 | if (copy_to_user(data_arg.data, &temp, datasize)) | |
343 | return -EFAULT; | |
344 | } | |
345 | return res; | |
346 | ||
347 | default: | |
348 | return i2c_control(client,cmd,arg); | |
349 | } | |
350 | return 0; | |
351 | } | |
352 | ||
353 | static int i2cdev_open(struct inode *inode, struct file *file) | |
354 | { | |
355 | unsigned int minor = iminor(inode); | |
356 | struct i2c_client *client; | |
357 | struct i2c_adapter *adap; | |
358 | struct i2c_dev *i2c_dev; | |
359 | ||
360 | i2c_dev = i2c_dev_get_by_minor(minor); | |
361 | if (!i2c_dev) | |
362 | return -ENODEV; | |
363 | ||
364 | adap = i2c_get_adapter(i2c_dev->adap->nr); | |
365 | if (!adap) | |
366 | return -ENODEV; | |
367 | ||
22f76e74 | 368 | client = kzalloc(sizeof(*client), GFP_KERNEL); |
1da177e4 LT |
369 | if (!client) { |
370 | i2c_put_adapter(adap); | |
371 | return -ENOMEM; | |
372 | } | |
22f76e74 JD |
373 | snprintf(client->name, I2C_NAME_SIZE, "i2c-dev %d", adap->nr); |
374 | client->driver = &i2cdev_driver; | |
1da177e4 LT |
375 | |
376 | /* registered with adapter, passed as client to user */ | |
377 | client->adapter = adap; | |
378 | file->private_data = client; | |
379 | ||
380 | return 0; | |
381 | } | |
382 | ||
383 | static int i2cdev_release(struct inode *inode, struct file *file) | |
384 | { | |
385 | struct i2c_client *client = file->private_data; | |
386 | ||
387 | i2c_put_adapter(client->adapter); | |
388 | kfree(client); | |
389 | file->private_data = NULL; | |
390 | ||
391 | return 0; | |
392 | } | |
393 | ||
394 | static struct file_operations i2cdev_fops = { | |
395 | .owner = THIS_MODULE, | |
396 | .llseek = no_llseek, | |
397 | .read = i2cdev_read, | |
398 | .write = i2cdev_write, | |
399 | .ioctl = i2cdev_ioctl, | |
400 | .open = i2cdev_open, | |
401 | .release = i2cdev_release, | |
402 | }; | |
403 | ||
79472132 | 404 | static struct class *i2c_dev_class; |
1da177e4 LT |
405 | |
406 | static int i2cdev_attach_adapter(struct i2c_adapter *adap) | |
407 | { | |
408 | struct i2c_dev *i2c_dev; | |
1da177e4 LT |
409 | |
410 | i2c_dev = get_free_i2c_dev(adap); | |
411 | if (IS_ERR(i2c_dev)) | |
412 | return PTR_ERR(i2c_dev); | |
413 | ||
b6d7b3d1 | 414 | pr_debug("i2c-dev: adapter [%s] registered as minor %d\n", |
9455e4c9 | 415 | adap->name, adap->nr); |
1da177e4 LT |
416 | |
417 | /* register this i2c device with the driver core */ | |
79472132 | 418 | i2c_dev->class_dev = class_device_create(i2c_dev_class, NULL, |
9455e4c9 JD |
419 | MKDEV(I2C_MAJOR, adap->nr), |
420 | &adap->dev, "i2c-%d", | |
421 | adap->nr); | |
79472132 | 422 | if (!i2c_dev->class_dev) |
1da177e4 | 423 | goto error; |
79472132 | 424 | class_device_create_file(i2c_dev->class_dev, &class_device_attr_name); |
1da177e4 LT |
425 | return 0; |
426 | error: | |
427 | return_i2c_dev(i2c_dev); | |
428 | kfree(i2c_dev); | |
79472132 | 429 | return -ENODEV; |
1da177e4 LT |
430 | } |
431 | ||
432 | static int i2cdev_detach_adapter(struct i2c_adapter *adap) | |
433 | { | |
434 | struct i2c_dev *i2c_dev; | |
435 | ||
9455e4c9 | 436 | i2c_dev = i2c_dev_get_by_minor(adap->nr); |
1da177e4 LT |
437 | if (!i2c_dev) |
438 | return -ENODEV; | |
439 | ||
1da177e4 | 440 | return_i2c_dev(i2c_dev); |
9455e4c9 | 441 | class_device_destroy(i2c_dev_class, MKDEV(I2C_MAJOR, adap->nr)); |
1da177e4 LT |
442 | kfree(i2c_dev); |
443 | ||
b6d7b3d1 | 444 | pr_debug("i2c-dev: adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
445 | return 0; |
446 | } | |
447 | ||
448 | static int i2cdev_detach_client(struct i2c_client *client) | |
449 | { | |
450 | return 0; | |
451 | } | |
452 | ||
1da177e4 | 453 | static struct i2c_driver i2cdev_driver = { |
35d8b2e6 | 454 | .driver = { |
35d8b2e6 LR |
455 | .name = "dev_driver", |
456 | }, | |
1da177e4 | 457 | .id = I2C_DRIVERID_I2CDEV, |
1da177e4 LT |
458 | .attach_adapter = i2cdev_attach_adapter, |
459 | .detach_adapter = i2cdev_detach_adapter, | |
460 | .detach_client = i2cdev_detach_client, | |
1da177e4 LT |
461 | }; |
462 | ||
1da177e4 LT |
463 | static int __init i2c_dev_init(void) |
464 | { | |
465 | int res; | |
466 | ||
467 | printk(KERN_INFO "i2c /dev entries driver\n"); | |
468 | ||
469 | res = register_chrdev(I2C_MAJOR, "i2c", &i2cdev_fops); | |
470 | if (res) | |
471 | goto out; | |
472 | ||
79472132 GKH |
473 | i2c_dev_class = class_create(THIS_MODULE, "i2c-dev"); |
474 | if (IS_ERR(i2c_dev_class)) | |
1da177e4 LT |
475 | goto out_unreg_chrdev; |
476 | ||
477 | res = i2c_add_driver(&i2cdev_driver); | |
478 | if (res) | |
479 | goto out_unreg_class; | |
480 | ||
1da177e4 LT |
481 | return 0; |
482 | ||
483 | out_unreg_class: | |
79472132 | 484 | class_destroy(i2c_dev_class); |
1da177e4 LT |
485 | out_unreg_chrdev: |
486 | unregister_chrdev(I2C_MAJOR, "i2c"); | |
487 | out: | |
488 | printk(KERN_ERR "%s: Driver Initialisation failed\n", __FILE__); | |
489 | return res; | |
490 | } | |
491 | ||
492 | static void __exit i2c_dev_exit(void) | |
493 | { | |
494 | i2c_del_driver(&i2cdev_driver); | |
79472132 | 495 | class_destroy(i2c_dev_class); |
1da177e4 LT |
496 | unregister_chrdev(I2C_MAJOR,"i2c"); |
497 | } | |
498 | ||
499 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl> and " | |
500 | "Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
501 | MODULE_DESCRIPTION("I2C /dev entries driver"); | |
502 | MODULE_LICENSE("GPL"); | |
503 | ||
504 | module_init(i2c_dev_init); | |
505 | module_exit(i2c_dev_exit); |